Protein Structure and Function

Oilbirds (Steatornis caripensis) breed in the total darkness of caves and forage at night on fruits. Common pauraques (Nyctidromus albicollis) are crepuscular and nocturnal foragers on flying insects. We examined if their retinal structure and function can be correlated with their types and periods of activity. Electroretinograms (ERGs) were obtained from anesthetized birds in photopic and scotopic conditions to a wide range of light intensities, following which the retinas were processed for histological analysis. Retinal sensitivity is higher in oilbirds than in common pauraques. Under scotopic conditions with maximum flash luminance, the average (± 95% CI) b-wave amplitude of oilbirds is double that of common pauraques (500.4 ± 49.8 and 245.4 ± 40.9 µV, respectively) but, under photopic conditions, the results are the reverse (common pauraque: 69.4 ± 18.1; oilbird: 23.0 ± 4.4 µV). On the other hand, the retina of both species is highly rod-dominated, but rods are highly more nume...

We examined in selected wading bird species if diurnal or nocturnal foraging and the use of visual or tactile feeding strategies could be correlated with retinal structure and function. The selected species were the Yellow-crowned Night Heron (Nycticorax violaceus), a crepuscular and nocturnal forager, the Great Blue Heron (Ardea herodias), a mainly crepuscular, but also diurnal and nocturnal feeder, the Roseate Spoonbill (Ajaia ajaja), a mainly crepuscular feeder which forages more at night than during the day, the Cattle (Bubulcus ibis) and Tricolored (Egretta tricolor) egrets and the American White Ibis (Eudocimus ruber) which forage only during daytime. Herons and egrets are visual foragers; ibises and spoonbills are tactile feeders. Electroretinograms were obtained from anesthetized birds in photopic and scotopic conditions to a wide range of light intensities, following which the retinae were processed for histological analysis. Based on rod densities and rods:cones ratios, no...

Some shorebird species forage with the same feeding strategy at night and during daytime, e.g. visual pecking in the Wilson’s Plover (Charadrius wilsonia) or tactile probing in the Short-billed Dowitcher (Limnodromus griseus). The American Woodcock (Scolopax minor) uses tactile probing, by day and by night, but sometimes pecks for insects during daytime. The Black-winged Stilt (Himantopus himantopus) is a visual pecker, both by day and by night, and sometimes forages tactilely on windy (agitated water surface) moonless nights. Territorial Willets (Catoptrophorus semipalmatus) are visual peckers during daylight and on moonlight conditions but switch to tactile feeding under lower light conditions. It could be postulated that some shorebird species would switch from visual feeding during daytime to tactile foraging at night because they have poor night vision compared to species that are always sight foragers irrespective of the time of the day. This issue was examined by comparing re...

J J J J JOURNAL OURNAL OURNAL OURNAL OURNAL CLUB CLUB CLUB CLUB CLUB Maedica-a Journal of Clinical Medicine T he most common malignancy in children is acute lymphoblastic leukemia (ALL). This malignancy occupies a percentage of 25 of all childhood cancers and 75 of all cases of childhood leukemia. One of the most important mechanisms which maintain the balance between life and death is apoptosis. The loss of apoptosis might result in the development of a wide variety of cancers, including ALL. In the last years a complex network of pro or anti-apoptotic proteins, which regulated the apoptosis pathways, have been identified. Livin (MIM no. 605737; baculoviral IAP repeat-containing 7, BIRC7; aliases, ML-IAP or KIAP) is a member of the inhibitor of apoptosis proteins which antagonize both the death receptor and mitochondria-based apoptotic pathways through the inhibition of caspases 3, 7, and 9. Until this study Livin expression has been regarded as a poor prognostic marker in malignan...

Background: Cloud computing (CC), artificial intelligence (AI), and the Internet of Things (IoT) are combining to revolutionise healthcare by making it possible to process data in real time and diagnose diseases. For increased accuracy and efficiency, optimised solutions are required because traditional approaches are unable to handle the volume and complexity of data from IoT-enabled devices. Objective: The objective of this research is to develop and apply a hybrid model that combines Radial Basis Function Networks (RBFN), Genetic Algorithms (GA), and Particle Swarm Optimisation (PSO) to improve accuracy, shorten processing times, and improve real-time healthcare disease diagnosis for chronic sickness identification. Methods: Optimisation of Recurrent Neural Networks (RNNs) and RBFNs for processing realtime data gathered from IoT devices was done using a hybrid PSO-GA framework. Preprocessing of the data occurred with cloud computing for extensive analysis, and optimisation were done to improve sensitivity and specificity metrics for various medical applications. Results: The suggested PSO-GA RNN-RBFN model performed exceptionally well, with 94% specificity, 92% sensitivity, and 93% accuracy. It reduced processing time to 54 seconds and outperformed conventional techniques like CNN, DeepDR, and EKF-SVM, making it ideal for real-time healthcare monitoring. Conclusion: A reliable method for real-time illness detection is provided by the combination of PSO, GA, and RBFN in a cloud-based architecture. As compared to conventional methods, the hybrid model dramatically increases accuracy, sensitivity, and specificity, proving its usefulness in managing intricate, urgent healthcare data.

The mechanical and water vapor permeability of starch/carrageenan cast films were investigated, the rheological properties of starch/carrageenan blends were also studied. The blends were prepared by different concentrations of starch and carrageenan. Three concentration of starch (0.75%, 1% and 1.25%) and two concentrations of carrageenan (0.5% and 0.75%) were used with adding 0.5% glycerol as plasticizer the results show that all samples behaves as nonNewtonian pseudoplastic fluid and obeys the power law relationship. The mechanical and water vapor permeability of the cast films increase with increasing carrageenan content.

Three years of regular weekly/biweekly monitoring of seasonal changes in temperature, transparency, chlorophyll a (CHL) and bacteria [erythrosine-stained microscopic counts and cultivable colony forming units (CFUs)] at the vertical profile in the South basin of Lake Baikal (51854V 195WN, 105804V 235WE, depth 800 m) were evaluated. In more detail, the structure and function of phytoplankton and the microbial loop in the euphotic layer at the same site were investigated during the late-winterearly-spring period under the ice. The depth of euphotic zone (up to 1% of surface irradiation) was 35 to 40 m. Primary production was measured three times a week with the 14 C method in 2, 10, 20, 30 and 40 m. Maximum production was found in 10 m, with lower values towards the surface (light inhibition) and towards the lower layers. The total production in cells larger than 1 Am in the column (0-40 m) was 204-240 mg C d À1 m À2 , 30-40% of it being in cells 1-3 Am (mostly picocyanobacteria), which represented roughly 9% of the total chlorophyll a (estimated from pigment analyses). A major part of phytoplankton biomass was formed by diatoms (Synedra acus Hust., Asterionella formosa Hass. and Stephanodiscus meyerii Genkal & Popovskaya). Total production (including extracellular, dissolved organic matter) was 235-387 mg C day À1 m À2 , and the exudates were readily used by bacteria (particles 0.2-1 Am). This part amounted to 1-5% of cellular production in 2 to 20 m and 11-77% of cellular production in 20-40 m, i.e., in light-limited layers. From 0 to 30 m, chlorophyll a concentration was 0.8 to 1.3 Ag l À1 , wherefrom it decreased rapidly to 0.1 Ag l À1 towards the depth of 40 m. Bacteria (DAPI-stained microscopic counts) reached 0.5-1.4Â10 6 ml À1 ; their cell volumes measured via image analysis were small (average 0.05 Am À3 ), often not well countable when erythrosine stain was used. Bacterial biomasses were in the range of 6-21 Ag C l À1 . Numbers of colony forming units (CFUs) on nutrient fish-agar were c. 3-4 orders lower than DAPI counts. The amounts of heterotrophic protists were low, whereby flagellates reached 6 to 87 ml À1 and ciliates, 0.2-1.2 ml À1 (mostly Oligotrichida). Bacterial production was measured in the same depths as primary production using 3 H-thymidine (Thy) and 14 C-leucine (Leu) uptake. Consistently, bacterial abundances, biomasses, thymidine and leucine production were higher by 30-50% in layers 2, 10 and 20 m compared

Purpose: There is increasing evidence that the progressive dysfunction induced by partial outlet obstruction is mediated by ischemia-reperfusion, and bladder decompensation results from ischemia-reperfusion induced damage to the cellular and subcellular organelle membranes of nerve and smooth muscle, mitochondria and sarcoplasmic reticulum. Tadenan, an extract of Pygeum africanum, is a therapeutic prescribed in Europe to relieve symptoms of obstructive bladder dysfunction secondary to benign prostatic hyperplasia. There is excellent experimental evidence that Tadenan treatment of obstructed rabbits reduces and reverses the progression of bladder decompensation. We determined whether Tadenan therapy can reverse the morphological damage associated with obstructive dysfunction. Material and Methods: A total of 36 male New Zealand White rabbits were separated into 6 groups of 6 each. Rabbits in groups 1 and 2 underwent sham operation. For 3 weeks beginning 2 weeks after sham operation group 1 was treated with vehicle and group 2 was treated with 30 mg./kg. Tadenan daily. Rabbits in groups 3 to 6 underwent partial outlet obstruction surgery. Two weeks after obstruction each rabbit was treated for 3 weeks with vehicle in group 3, and with 1, 10 and 30 mg./kg. Tadenan in groups 4, 5 and 6, respectively. After the completion of treatment cystometry was performed on each rabbit and isolated bladder strips were evaluated for contractile responses to field stimulation, adenosine triphosphate, carbachol and KCl. Separate strips were fixed for electron microscopy to determine the location and severity of cellular and subcellular membrane damage. Results: Partial outlet obstruction resulted in reduced compliance, decreased responses of bladder strips to all forms of stimulation tested, and significant and extensive damage to cellular and subcellular organelle membranes consistent with an ischemia-reperfusion etiology. Daily 1 and 10 mg./kg. Tadenan treatments had little effect on the obstruction induced increase in bladder weight or the deleterious changes in bladder function and structure. However, treating obstructed rabbits with 30 mg./kg. Tadenan daily resulted in reduced bladder hypertrophy, improved compliance, improved contractile responses to nearly normal levels of isolated bladder strips to all stimuli tested and reversal of obstruction induced structural damage to cellular and subcellular organelle membranes. Conclusion: Tadenan treatment of obstructed rabbits resulted in a dose dependent improvement in bladder ultrastructure in parallel with improved bladder compliance and contractile responses of isolated strips to stimulation, providing support for the hypothesis that damage to cellular and subcellular organelle membranes mediates the contractile dysfunction induced by partial outlet obstruction.

The pancreatic 0-cell has the unique capability to express the insulin gene and to synthesize, store and release insulin exactly according to the needs of the body. In a broad sense the 0-cell can be regarded as a biological sensor of circulating metabolic substrates, which are controlled by a feed-back system involving insulin secretion. Insulin is synthesized on the endoplasmic reticulum in the form of preproinsulin which is rapidly cleaved to proinsulin, transported to the Golgi zone and packed into secretory granules. Proinsulin is converted into C-peptide and biologically active insulin which is stored in the granules until released as a result of one or several specific signals reaching the 0-cell. The most important of these is an elevation of the blood glucose level, which causes an insulin response directly proportional to the glucose concentration. This process is of decisive importance for the short-term regulation of the blood glucose level. Of equal importance, however, is the total 0cell mass, which determines the capacity for insulin production in the long-term and is the result of an adaptive growth process. A deficient insulin production in relation to the insulin requirement is a common denominator of all types of diabetes. This state may be induced by the action of toxins, viruses or autoimmune assaults on the 0-cell or, perhaps, exhaustion from a long-standing functional demand on the insulin production. There is still poor knowledge on the various states of insulin deficiency and a deeper insight into the underlying mechanisms would greatly enhance the attempts to find a treatment or cure for diabetes and also to introduce measures for complete prevention of the disease. The present paper will summarize some recent observations on factors regulating insulin production and mechanisms of 0-cell proliferation and degeneration. Control of insulin gene expression is achieved through synthesis, processing, transport and degradation of insulin mRNA. The islet content of insulin mRNA is

The pancreatic 0-cell has the unique capability to express the insulin gene and to synthesize, store and release insulin exactly according to the needs of the body. In a broad sense the 0-cell can be regarded as a biological sensor of circulating metabolic substrates, which are controlled by a feed-back system involving insulin secretion. Insulin is synthesized on the endoplasmic reticulum in the form of preproinsulin which is rapidly cleaved to proinsulin, transported to the Golgi zone and packed into secretory granules. Proinsulin is converted into C-peptide and biologically active insulin which is stored in the granules until released as a result of one or several specific signals reaching the 0-cell. The most important of these is an elevation of the blood glucose level, which causes an insulin response directly proportional to the glucose concentration. This process is of decisive importance for the short-term regulation of the blood glucose level. Of equal importance, however, is the total 0cell mass, which determines the capacity for insulin production in the long-term and is the result of an adaptive growth process. A deficient insulin production in relation to the insulin requirement is a common denominator of all types of diabetes. This state may be induced by the action of toxins, viruses or autoimmune assaults on the 0-cell or, perhaps, exhaustion from a long-standing functional demand on the insulin production. There is still poor knowledge on the various states of insulin deficiency and a deeper insight into the underlying mechanisms would greatly enhance the attempts to find a treatment or cure for diabetes and also to introduce measures for complete prevention of the disease. The present paper will summarize some recent observations on factors regulating insulin production and mechanisms of 0-cell proliferation and degeneration. Control of insulin gene expression is achieved through synthesis, processing, transport and degradation of insulin mRNA. The islet content of insulin mRNA is

Extracellular polymeric substances (EPS) seem to play a pivotal role in bioleaching-the winning of precious metals as well as acid rock drainage. For a better control of both processes structure and function of extracellular polymeric substances from leaching bacteria are of crucial importance. Our research focussed on Acidithibacillus ferrooxidans, the composition of its extracellular polymeric substances and further deduction of their function. The extracellular polymeric substances of Acidithiobacillus ferrooxidans consist mainly of neutral sugars and lipids. The functions of the extracellular polymeric substances of this leaching bacterium seem to be (i) to mediate attachment to a (metal) sulfide surface, (ii) to concentrate iron(III) ions by complexation through uronic acids or other residues at the mineral surface and, thus, allowing for an oxidative attack on the sulfide. Consequently, dissolution of the metal sulfide is enhanced, which may result in an acceleration of 20-to 100-fold over chemical leaching. Experiments were performed to elucidate the importance of the iron(III) ions complexed by extracellular polymeric substances for strain-specific differences in oxidative activity for pyrite. The preliminary data indicate that strains of Acidithiobacillus ferrooxidans, with a high amount of iron(III) ions in their extracellular polymeric substances, possess a higher oxidation activity than those with less iron(III) ions. These data provide new insight into the function of extracellular polymeric substances and the consequent advantage conferred to bacteria involved in bioleaching.

To evaluate the neuroprotective effects of adenoassociated virus delivery of XIAP in N-methyl-N-nitrosourea (MNU)induced retinal degeneration in Sprague-Dawley rats. METHODS. Sprague-Dawley rats were injected subretinally with recombinant adenoassociated virus (rAAV) encoding either XIAP or green fluorescent protein (GFP; injection control). Six weeks after injection, the animals received an intraperitoneal injection of MNU, a DNA methylating agent, at a dose of 60 mg/kg. Electroretinograms (ERGs) were recorded at 0, 24, 48 and 72 hours and 1 week after MNU. The rats were killed after the ERG was performed and were perfused with 4% paraformaldehyde. Eyes were then enucleated and embedded for cryosectioning. Eye sections were analyzed by TUNEL and histologic techniques. Real-time PCR and Western analysis were performed to confirm the overexpression of XIAP in injected eyes. RESULTS. Real-time PCR and Western analysis confirmed the overexpression of XIAP in virus-injected eyes in comparison to uninjected control eyes. At 24 hours after MNU injection, fewer cells had undergone apoptosis in the XIAP-treated eyes in comparison with GFP-injected or uninjected eyes. Hematoxylin and eosin staining revealed that the uninjected and GFPinjected photoreceptors were destroyed by 72 hours after injection of MNU, whereas the AAV-XIAP-injected eyes showed structural protection of the photoreceptors at all time points throughout the 1-week sampling period. ERGs showed functional protection up to 1 week after MNU injection in the AAV-XIAP-injected eye, whereas no response was observed in the control eye. CONCLUSIONS. The results suggest that XIAP is protective against this potent chemotoxic agent and holds promise as a therapeutic agent in gene therapy approaches to treating retinitis

One of the dramatic effects of global warming is the retreat of glaciers. This phenomenon has intensified in the last two decades. Postglacial areas are quickly colonised by various groups of organisms. Auto- and heterotrophic microorganisms play an especially vital role in these processes. They thrive in shallow glacial lagoons which often form in front of retreating glaciers. These reservoirs are characterised by high dynamics of physicochemical parameters, including: salinity, temperature and concentrations of organic compounds and nutrients. The conducted microbiological studies have revealed rich structural and functional diversity of bacteria occurring in the ecosystem of Ecology Lagoon situated on King George Island. Bacteria found on the surface of algae and stones in the shore zone of the lagoon showed particularly intense metabolic activity. A molecular analysis has indicated that unique taxonomic groups of bacteria occur in the ecosystem of Ecology Lagoon.

The purpose of this study was to explore pre-service science teachers' use of an interactive system, consisting of a computer, LCD projector, interactive white board, and Internet connection, to support science teaching and learning. Each participant had an access to the interactive system for the duration of the investigation. The research questions guiding the investigation included: 1. Whether teachers would use the interactive system for instructional purposes? 2. What form would this instruction take?and 3. Whether the instruction would reflect the recommendations of current science education reform documents? The results indicated that the teachers use the interactive system in substantial ways to facilitate the teaching reforms based on the science. Furthermore, the results support the use of explicit approaches to prepare the pre-service teachers to use educational technology for inquiry instruction, modelling of effective uses of digital images and video clips, and specific instruction on whole class inquiry methods.

The purpose of this study was to explore pre-service science teachers' use of an interactive system, consisting of a computer, LCD projector, interactive white board, and Internet connection, to support science teaching and learning. Each participant had an access to the interactive system for the duration of the investigation. The research questions guiding the investigation included: 1. Whether teachers would use the interactive system for instructional purposes? 2. What form would this instruction take?and 3. Whether the instruction would reflect the recommendations of current science education reform documents? The results indicated that the teachers use the interactive system in substantial ways to facilitate the teaching reforms based on the science. Furthermore, the results support the use of explicit approaches to prepare the pre-service teachers to use educational technology for inquiry instruction, modelling of effective uses of digital images and video clips, and specific instruction on whole class inquiry methods.

The project of the Government of the Republic of Macedonia “A computer for each child “is in a process of realization. Meanwhile, TEMPUS, the project whose beholder is The Faculty of Pedagogy of The University of “Goce Delcev“ in Stip, in which a few elementary and high schools from Eastern Macedonia are also included , is in a process of realization as well. One of the achievements of the project itself is introducing the active board in the educational process. Various educational contents can be displayed and be presented in a way that makes learning challenging, fun and active. The active board is a window towards the world, a world in which the new technology is about to arrive! The goal of this project is to realize the advantages and disadvantages of using the active board in the traditional and contemporary education, for learning the contents of the subject “Introducing the environment” for third grade in the nine-grade primary education.

ATP-dependent chromatin remodeling enzymes (remodelers) regulate access to genomic DNA by reading epigenetic marks such as histone modifications and using the energy of ATP hydrolysis to assemble, reposition, disassemble, and modify the composition of nucleosomes. The catalytic activity of remodeling enzymes is highly regulated by various substrate characteristics including extranucleosomal linker DNA, histone modifications, and linker histones. In this thesis, we developed and employed a synergistic combination of single-molecule biophysical techniques and biochemical approaches to elucidate the mechanisms underpinning the regulation of chromatin remodelers by these substrate features. The imitation switch (ISWI)-family of remodelers promotes heterochromatin formation and transcriptional silencing by generating regularly-spaced nucleosome arrays. It was previously known that this nucleosome-spacing activity arises from the dependence of nucleosome translocation on the length of linker DNA, but the underlying mechanism remains unclear. We studied nucleosome remodeling by the human ATPdependent chromatin assembly and remodeling factor (ACF), an ISWI enzyme composed of a catalytic subunit, Snf2h, and an accessory subunit, Acf1. The H4 tail bears significant sequence homology to an autoinhibitory domain, AutoN, present in the catalytic subunit. The presence of an unmodified H4 tail is thought to stimulate catalytic activity by competing with AutoN for a binding site on the ATPase. Our results suggest a mechanism for nucleosome spacing where linker DNA is sensed by the N-terminus of Acf1 and allosterically transmitted to Snf2h through the H4 tail of the nucleosome. For nucleosomes with short linker DNA, Acf1 preferentially binds to the H4 tail, allowing AutoN to inhibit the ATPase activity of Snf2h. As the linker DNA lengthens, Acf1 shifts

Abstract. The paper is focused on a comparative study regarding shoot morphology and anatomy of two climbing rose cultivars, from the Botanic Garden of Iasi: 'Ilse Krohn Superior' and 'Sympathie'. The shoot presents a thick collenchymatized cortex, which bears ...

A steady series of advances in physics, mathematics, computers and clinical imaging science have progressively transformed diagnosis and treatment of neurological and neurosurgical disorders in the 115 years between the discovery of the X-ray and the advent of high resolution diffusion based functional MRI. The story of the progress in human terms, with its battles for priorities, forgotten advances, competing claims, public battles for Nobel Prizes, and patent priority litigations bring alive the human drama of this remarkable collective achievement in computed medical imaging.

In 1875, Richard Caton, a physician and medical lecturer from Liverpool, discovered that brain electrical signals could be recorded directly from the surface of the exposed cortex using a reflecting galvanometer. A half century later, Hans Berger (1929) was able to detect these brain waves with electrodes placed on scalp. He, like Caton, noted that these voltages could be influenced by external events that stimulated the senses.

2q, 7q, 8p, and 14q. Chromosome-specific STSs for 27 telomeres were identified from the 196 TYACs. More A YAC library enriched for telomere clones was constructed and screened for the human telomere-specific than 30,000 nucleotides derived from the TYAC vectorinsert junction regions or from regions flanking TYAC repeat sequence (TTAGGG). Altogether 196 TYAC library clones were studied: 189 new TYAC clones were microsatellites were compared to reported sequences using BLASTN. In addition to identifying homology isolated, 149 STSs were developed for 132 different TY-ACs, and 39 P1 clones were identified using 19 STSs with previously reported telomere sequences and human repeat elements, gene sequences and a number of from 16 of the TYACs. A combination of mapping methods including fluorescence in situ hybridization, so-ESTs were found to be highly homologous to the TYAC sequences. These genes include human coagulation matic cell hybrid panels, clamped homogeneous electric fields, meiotic linkage, and BLASTN sequence factor V (F5), Wee1 protein tyrosine kinase (WEE1), neurotropic protein tyrosine kinase type 2 (NTRK2), analysis was utilized to characterize the resource. Forty-five of the TYACs map to 31 specific telomere glutathione S-transferase (GST1), and b tubulin (TUBB). The TYAC/P1 resource, derivative STSs, and regions. Twenty-four linkage markers were developed and mapped within 14 proterminal regions (12 te-polymorphisms constitute an enabling resource to further studies of telomere structure and function and a lomeres and 2 terminal bands). The polymorphic markers include 12 microsatellites for 10 telomeres (1q, 2p, means for physical and genetic map integration and closure. ᭧ 1996 Academic Press, Inc. 6q, 7q, 10p, 10q, 13q, 14q, 18p, 22q) and the terminal bands of 11q and 12p. Twelve RFLP markers were identified and meiotically mapped to the telomeres of INTRODUCTION Sequence data from this article have been deposited with the In most eukaryotes the ends of linear chromosomes

A 29,59-oligoadenylate (2-5A)-dependent 37-kDa form of RNase L has been reported in extracts of peripheral blood mononuclear cells (PBMC) from individuals with chronic fatigue syndrome (CFS). In the current study, analytic gel permeation FPLC, azido photoaffinity labeling, two-dimensional (2-D) gel electrophoresis, and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) have been used to examine the biochemical relationship between the 80-kDa RNase L in healthy control PBMC and the 37-kDa RNase L in PBMC from individuals with CFS. Like the 80-kDa RNase L, the 37-kDa RNase L is present as a catalytically inactive heterodimer complex with the RNase L inhibitor (RLI). Formation of a 37-kDa RNase L-RLI complex indicates that the 37-kDa RNase L is structurally similar to the 80-kDa RNase L at the N-terminus, which contains the 2-5A binding domain. The enzymatically active monomer form of 37-kDa RNase L resolved by 2-D gel electrophoresis has a pI of 6.1. RT-PCR and Southern blot analyses demonstrated that the 37-kDa RNase L is not formed by alternative splicing. In-gel tryptic digestion of the 37-kDa RNase L that was excised from 2-D gels and subsequent MALDI-MS analysis identified three peptide masses that are identical to three predicted peptide masses in the 80-kDa RNase L. The electrophoretic mobility of 2-5A azido photolabeled/immunoprecipitated 37-kDa RNase L was the same under reducing and nonreducing conditions. The results presented show that the 37-kDa form of RNase L in PBMC shares structural and functional features with the native 80-kDa RNase L, in particular in the 2-5A binding and catalytic domains.

Functional MRI (fMRI) requires MRI pulse sequences with both high spatial and temporal resolution. In particular, for single event fMRI, the simultaneous measurement of as many slices as possible is necessary. Recently 'simultaneous image refocusing' (SIR) has been proposed as a new approach for single-shot multislice imaging . In the following a multislice variant of UFLARE ('ultrafast low angle RARE', ) is described which allows to measure N sl slices within one echo train, and each two slices to be acquired with identical T 2 * weighting. Furthermore, in contrast to the echo planar imaging (EPI) based SIR approach, in single-shot multislice U-FLARE, the delay between the acquired echoes originating from a certain slice is constant, thus avoiding image artifacts in phase encoding (PE) direction. The pulse sequence used for single-shot multislice T 2 * weighted U-FLARE imaging is shown in Fig. (for simplicity only for two slices). After simultaneous RF excitation of all slices (t=0) a train of alphapulses starts at t=TE. Echoes from all slices are consecutively acquired between each two consecutive alpha-pulses using 'displaced U-FLARE' . Within the delay TE between RF excitation and the start of the train of alpha-pulses the signals of slice m are refocused at time Note that the position of the echo within the delay between each two consecutive alpha-pulses will also contribute to the T 2 ' weighting to a small amount. If appropriate gradient pulses in read direction are applied between the 180 0 pulses, the echoes of different slices are shifted and can be acquired within adjacent parts of the acquisition window. Note that the signals of each two slices can be acquired with identical T 2 ' weighting. Furthermore, ghosts in PE direction can be avoided because the echo (slice) order is the same for all PE steps. Hardware: All experiments were carried out on a 4.7T/40cm Bruker Biospec system equipped with self-shielded gradients (170 mT/m, 450 ms). RF excitation was performed by a saddle-type resonator (98 mm i.d.) and an 18 mm surface coil was used for signal reception. fMRI Animal Model: In vivo measurements were performed on healthy male Wistar rats anaesthetized with alpha-chloralose and positioned in a stereotactic animal holder. Two periods of electrical stimulation (1 mA during 0.3 ms with 3 Hz frequency [4]) of one forepaw were used each lasting 1 minute. Both stimulation periods were bracketed by 1 minute periods of rest giving a total duration of the fMRI experiment of 5 minutes. Pulse Sequence: Single-shot double-slice U-FLARE imaging was performed with the following parameters: FOV: 48*48 mm 2 ; 2 slices; slice thickness: 2 mm; distance between slice centers: 2.5 mm; displaced U-FLARE with 102 echoes (6 dummy and 96 PE), interecho delay: 4.84 ms, alpha=90 0 using optimized flip angles for the first two refocusing pulses to improve echo stabilization ; acquisition time between adjacent alpha-pulses: 3.2 ms (2*1.6 ms) with 128 complex data points per slice; T 2 ' weighting: 20.8 ms; TR: 3.0 s. Data Processing: The images were reconstructed using sine-bell apodization in k x and k y , 2D FFT and magnitude calculation. A Bonferroni corrected t-test was used to determine the significance of signal changes between periods with and without stimulation. T 2 * weighted U-FLARE images of both slices are shown in Fig. . The stimulated brain area in slice 1 determined by a t-test comparing images acquired during rest and stimulation, respectively, is depicted in Fig. . Fig. shows the signal evolution in the central voxel of the stimulated area of slice 1 and 2. In slice 1, which was positioned in agreement with [4], the signal increase during electrical forepaw stimulation is well detected, whereas in slice 2 only minor changes are observed. Therefore, these results demonstrate that single-shot multislice U-FLARE imaging is feasible and can be used for fMRI studies.

▪   The cytochrome bc complexes represent a phylogenetically diverse group of complexes of electron-transferring membrane proteins, most familiarly represented by the mitochondrial and bacterial bc1complexes and the chloroplast and cyanobacterial b6f complex. All these complexes couple electron transfer to proton translocation across a closed lipid bilayer membrane, conserving the free energy released by the oxidation-reduction process in the form of an electrochemical proton gradient across the membrane. Recent exciting developments include the application of site-directed mutagenesis to define the role of conserved residues, and the emergence over the past five years of X-ray structures for several mitochondrial complexes, and for two important domains of the b6f complex.

Modern pathologists have been challenged to “validate” mouse models of human cancer. Validation requires matching of morphological attributes of the model to human disease. Computers can assist in the validation process. However, adequate controlled, computer-readable vocabularies that can match terms do not currently exist in mouse pathology. Further, current standard diagnostic terminologies do not include the new concepts discussed here such as pathway pathology and mammary intraepithelial neoplasia. The terminologies must be revised and improved to meet the challenge. Human medicine has traditionally used “guilt-by-association” to validate interpretations of disease. Experimental pathology uses experimental verification exemplified by “test-by-transplantation.” Genetically Engineered Mice (GEM) develop unique tumor phenotypes bringing new structural-functional insights and reevaluation of concepts. Novel GEM-related tumors appear in all organ systems but mouse models of human br...

Dengue virus (DENV) is the most prevalent insect-transmitted viral disease in humans globally, and currently no specific therapy or vaccine is available. Protection against DENV and other related flaviviruses is associated with the development of antibodies against the viral envelope (E) protein. Although prior studies have characterized the neutralizing activity of monoclonal antibodies (MAbs) against DENV type 2 (DENV-2), none have compared simultaneously the inhibitory activity against a genetically diverse range of strains in vitro , the protective capacity in animals, and the localization of epitopes. Here, with the goal of identifying MAbs that can serve as postexposure therapy, we investigated in detail the functional activity of a large panel of new anti-DENV-2 mouse MAbs. Binding sites were mapped by yeast surface display and neutralization escape, cell culture inhibition assays were performed with homologous and heterologous strains, and prophylactic and therapeutic activi...

We analyzed the metal-binding properties of human centrin-2 (HsCen-2) and followed the changes in HsCen-2 structure upon metal-binding using micro-electrospray ionization mass spectrometry (ESI-MS). Apo-HsCen-2 is mostly monomeric. The ESI spectra of HsCen-2 show two charge-state distributions, representing two conformations of the protein. HsCen-2 binds four moles calcium/mol protein: one mol of calcium with high affinity, one additional mol of calcium with lower affinity, and two moles of calcium at low affinity sites. HsCen-2 binds four moles of magnesium/mol protein. The conformation giving the lower charge-state HsCen-2 by ESI, binds calcium and magnesium more readily than does the higher charge-state HsCen-2. Both conformations of HsCen-2 bind calcium more readily than magnesium. Calcium was more effective in displacing magnesium bound to HsCen-2 than vice versa. Binding of a peptide from a known binding partner, the xeroderma pigmentosum complementation group protein C (XPC), to apo-HsCen-2, occurs in the presence or the absence of calcium. Near and far-UV CD spectra of HsCen-2 show little difference with addition of calcium or magnesium. Minor changes in secondary structure are noted. Melting curves derived from temperature dependence of molar ellipticity at 222 nm for HsCen-2 show that calcium increases protein stability whereas magnesium does not. ⌬25 HsCen-2 behaves similarly to HsCen-2. We conclude that HsCen-2 binds calcium and magnesium and that calcium modulates HsCen-2 structure and function by increasing its stability without undergoing significant changes in secondary or tertiary structure. (

Background MicroRNAs (miRNAs) constitute a class of single-stranded RNAs which play a crucial role in regulating development and controlling gene expression by targeting mRNAs and triggering either translation repression or messenger RNA (mRNA) degradation. miRNAs are widespread in eukaryotes and to date over 14,000 miRNAs have been identified by computational and experimental approaches. Several miRNAs are highly conserved across species. In Schistosoma, the full set of miRNAs and their expression patterns during development remain poorly understood. Here we report on the development and implementation of a homology-based detection strategy to search for miRNA genes in Schistosoma mansoni. In addition, we report results on the experimental detection of miRNAs by means of cDNA cloning and sequencing of size-fractionated RNA samples. Results Homology search using the high-throughput pipeline was performed with all known miRNAs in miRBase. A total of 6,211 mature miRNAs were used as r...

This paper aims to highlight the facilities that Geographical Information Systems make them available to the users in order to determine optimal solutions for the distribution of stands to be exploited. It also highlights opportunities available to control these systems and suggested solutions. For the study area were chosen vectorized cadastral plans and have taken some points and GPS equipment. After this were measured diameters and heights of trees with which the volumes were determined and then the allowable cut

The presence of abnormal visual function has been related to overt lesions in the thalami, peritrigonal white matter (such as cavitational-necrotic periventricular leucomalacia) and optic radiations, and also to the extent of occipital cortex involvement. The normal development of visual function seems to depend on the integrity of a network that includes not only optic radiations and the primary visual cortex but also other cortical and subcortical areas, such as the frontal or temporal lobes or basal ganglia, which have been found to play a topical role in the development of vision. Therefore, the complex functions and functional connectivity of the developing brain of premature infants can be studied only with highly sophisticated techniques such as diffusion tensor tractography. The combined use of visual tests and neonatal structural and functional neuroimaging, which have become available for newborn infants, provides a better understanding of the correlation between structure and function from early life. This appears to be particularly relevant considering the essential role of early visual function in cognitive development. The identification of early visual impairment is also important, as it allows for early enrolment in intervention programmes. The association of clinical and functional studies to newer imaging techniques, which are being increasingly used also in neonates, are likely to provide further information on early aspects of vision and the mechanisms underlying brain plasticity, which are still not fully understood. Early exposure to a difficult postnatal environment together with early and unexpected removal from a protective milieu are exclusive and peculiar factors of prematurity that interfere with the normal development of the visual system in pre-term babies. The problem is further compounded by the influence of different perinatal brain lesions affecting the developing brain of premature babies. Nevertheless, in the last few decades, there have been considerable advances in our understanding of the development of vision in pre-term infants during early infancy. This has mainly been due to the development of age-specific tests assessing various aspects of visual function, from ophthalmological examination to more cortical aspects of vision, such as the ability to process orientation or different aspects of visual attention . Improvements in understanding very early and specific neurological impairments in neurological functions have been reported in pre-term infants, known to be at risk of developing visual and visual-perceptual impairment. These impairments are due not only to retinopathy, a common finding in premature infants, but also to cerebral (central) visual impairment, secondary to brain lesions affecting the central visual pathway.

Long-term tree and seedling growth and survivorship data from permanent sample plots established in a neotropical dry forest in Jamaica from 1998 to 2008 were used to (1) model growth (periodic annual increment) and survivorship dynamics, (2) cluster structural and functional types, and (3) estimate the age of selected tropical dry forest tree species. A statistical comparison of parameter estimates derived from a generalized linear model (GLM) of each species to a reference species was used to group individuals based on size (DBH and height), and demographic dynamics (periodic annual increment and survivorship). We identified two groups of species based on structural types (canopy and sub-canopy species), three groups of species based on periodic annual increment (fast, intermediate, and slow growing) and four groups of species based on the probability of survivorship of seedlings and trees (very low probability of seedling survivorship but high tree survivorship (two groups); high survivorship throughout the DBH classes; very low survivorship, regardless of stem size). The composition of the groups was mixed, and included individuals of both structural types, and with different periodic annual increment and survival probabilities. The dichotomy of guilds found in tropical rainforests (pioneer and climax species) was not found in this forest. Individual and group GLMs incorporating empirical relationships between periodic annual increment and survivorship, across a spectrum of ontogenies and DBH's, were also generated. The periodic annual increment models were then used to estimate the time taken by a newly germinated seedling to reach the largest recorded DBH. The fastest growing species was the hemi-cryptophyte Clusia flava which was estimated to take 74 years to reach its maximum recorded size (12.1 cm DBH), whereas the slowest growing species, Ziziphus sarcomphalus, was estimated to take 399 years to reach its maximum size (24.4 cm DBH). These dry forest trees were estimated to reach their maximum size (which was one-half or one-third of the largest DBH recorded for tropical rainforests) in a time similar to tropical rainforest trees. Some of the tree species are ubiquitous to other neotropical dry forests; therefore, our equations for periodic annual increment and survivorship can be applied elsewhere in the region.

p73, a new p53 family member, is a transcription factor that is increasingly recognized in cancer research as an important player in tumorigenesis as well as in chemotherapeutic drug sensitivity. Despite the substantial structural and functional similarities to p53, accumulating evidence suggests that p53 and p73 may differently regulate their transcriptional targets. In this study, we have investigated the role of p73 in regulation of the gastrin gene promoter. Gastrin is a peptide hormone and an important factor in determining the progression of a number of human malignancies. Our results show that p73 can bind to the gastrin promoter. This leads to transcriptional upregulation of gastrin mRNA. We also found that the levels of gastrin and p73 transcripts correlate in primary gastric tumors. Taken together, our results demonstrate a novel mechanism for regulation of gastrin gene transcription and support a concept that p53 and p73 may have different biological roles in tumors.

Coronary sinus mapping is commonly used to evaluate left atrial activation. Herein, we propose to use it to assess which right ventricular pacing modality produces the shortest left ventricular activation times (R-LVtime) and the narrowest QRS widths. Three study groups were defined: 54 controls without intraventricular conduction disturbances; 15 patients with left bundle branch block, and 15 patients with right bundle branch block. Left ventricular activation times and QRS widths were evaluated among groups under sinus rhythm, right ventricular apex, right ventricular outflow tract and high output septal zone (SEPHO). Left ventricular activation time was measured as the time elapsed from the surface QRS onset to the most distal left ventricular deflection recorded at coronary sinus. During the above stimulation modalities, coronary sinus mapping reproduced electrical differences that followed mechanical differences measured by tissue doppler imaging. Surprisingly, 33% of the patie...

Ecotoxicological Classification Risk Index for Soil (ECRIS), is a new classification system specific for soil risk assessment, which gives a comparative indication of the risk linked to environmental contamination by any chemical. In this work this parameter was estimated by quantitative structure-activity relationship approaches by using interpretable molecular descriptors. Linear and nonlinear models were developed using Multiple Linear Regressions (MLR) and Artificial Neural Network (ANN) methods. Robustness and reliability of the constructed MLR and ANN models were evaluated by using the leave-oneout cross-validation method, which produces the statistics of Q2 MLR = 0.84, Q2 ANN = 0.93. Furthermore, the chemical applicability domains of these models were determined via leverage approach. The results of this study indicated the ability of developed QSPR models in the prediction of ECRIS of various chemicals from their calculated molecular structural descriptors.

Background: Recently, in the year 2019, the National Medical Commission (NMC) made it mandatory to implement objectively structured practical examination (OSPE) for pre-and para-clinical subjects. The OSPE is an assessment tool used during practical examinations for undergraduate medical students studying in phase I and phase II.

Objectives. Versican is the principal large proteoglycan expressed in mid-tendon, but its role in tendon pathology is unknown. Our objective was to define the expression of versican isoform splice variant messenger ribonucleic acid (mRNA) in normal Achilles tendons, in chronic painful tendinopathy and in ruptured tendons. Methods. Total RNA isolated from frozen tendon samples (normal n ¼ 14; chronic painful tendinopathy n ¼ 10; ruptured n ¼ 8) was assayed by relative quantitative reverse transcriptase polymerase chain reaction (RT-PCR) for total versican, versican variants V0, V1, V2, V3 and type I collagen 1 mRNA, normalized to glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Differences between sample groups were tested by Wilcoxon statistics. Results. Painful and ruptured tendons showed a significant decrease (median 2-fold) in the expression of versican mRNA, in contrast to an increased expression (median 8-fold) of type I collagen 1 mRNA in painful tendons. Versican splice variants V0 and V1 mRNA were readily detected in normal samples, V3 levels were substantially lower, and V2 levels were more variable. Each of V1, V2 and V3 mRNA showed significant decreases in expression in painful and ruptured tendons, but V0 was not significantly changed. Conclusions. Changes in versican expression relative to that of collagen, and alterations in the balance of versican splice variants, may contribute to changes in matrix structure and function in tendinopathies.

Exposing bovine lipid extract surfactant (BLES), a clinical surfactant, to reactive oxygen species arising from hypochlorous acid or the Fenton reaction resulted in an increase in lipid (conjugated dienes, lipid aldehydes) and protein (carbonyls) oxidation products and a reduction in surface activity. Experiments where oxidized phospholipids (PL) were mixed with BLES demonstrated that this addition hampered BLES biophysical activity. However the effects were only moderately greater than with control PL. These results imply a critical role for protein oxidation. BLES oxidation by either method resulted in alterations in surfactant proteins SP-B and SP-C, as evidenced by altered Coomassie blue and silver staining. Western blot analyses showed depressed reactivity with specific antibodies. Oxidized SP-C showed decreased palmitoylation. Reconstitution experiments employing PL, SP-B, and SP-C isolated from control or oxidized BLES demonstrated that protein oxidation was more deleterious than lipid oxidation. Furthermore, addition of control SP-B can improve samples containing oxidized SP-C, but not vice versa. We conclude that surfactant oxidation arising from reactive oxygen species generated by air pollution or leukocytes interferes with surfactant function through oxidation of surfactant PL and proteins, but that protein oxidation, in particular SP-B modification, produces the major deleterious effects.

A compreensão da composição e inter-relações das comunidades faunísticas são fundamentais para a execução de medidas conservacionistas em ambientes florestais. No presente estudo nos avaliamos a comunidade de anfíbios de uma floresta estadual no município de Rio Claro, SP, com enfoque na biologia reprodutiva. Foram registradas 21 espécies, de quarto famílias: Bufonidae, Hylidae, Leptodactylidae e Microhylidae. As espécies da família Bufonidae reproduziram durante a estação fria e seca do ano e as demais somente durante a estação quente e chuvosa. Além de segregação temporal, algumas espécies dividiram o ambiente físico durante o período reprodutivo. Acentuada sobreposição temporal e espacial foi observada entre espécies filogeneticamente próximas, como entre Hyla nana e H. sanborni, entre Scinax fuscovarius e Scinax sp. (aff. similis), e entre Leptodactylus fuscus, L. mystacinus, e Leptodactylus sp. (gr. fuscus). Nestes casos, diferenças acústicas podem ter sido o principal fator re...

1 The response of peat-rich permafrost soils to human-induced climate change may be especially important in modifying the global C-flux. We examined the Holocene developmental record of a High Arctic peat-forming wetland to investigate its sensitivity to past climate change and aid understanding of the likely effects of future climate warming on high-latitude ecosystems. 2 The microhabitat of mosses was quantified in the present-day polygon-complex at Bylot Island (73 ° N, 80 ° W) and used to interpret the radiocarbon-dated macrofossil record of three cores, comprising c. 3500 years of wetland development. Recurrent wet and dry phases in the reconstructed palaeohydrological record indicated pronounced temporal variability. Wet and dry phases were compared between cores and with palaeoclimatic proxy values, measured as percentage melt and δ 18 O in nearby ice cores. 3 Periodic wet and dry phases appear unrelated to past climate over c. 50% of the combined stratigraphic records, and are attributable instead to geomorphological mechanisms. At other times, association of wet and dry phases with significantly lower and higher values of percentage melt and δ 18 O indicate a possible effect of past climate change on polygon hydrology and vegetation, although inconsistencies between cores suggest that local geomorphological processes continued to modify a regional climatic effect. However, during a period incorporating the Little Ice Age ( c. 305-530 cal. years  ), reconstructed moisture and vegetation change is pronounced and consistent among all three cores. 4 The results provide strong evidence for the sensitivity of a High Arctic terrestrial ecosystem to past climate change during the Holocene. The estimated magnitude of changes in soil moisture between wet and dry phases is sufficient to imply recurrent shifts in wetland function, periodically impacted upon by pronounced climatic variability, although controlled principally by autogenic processes. The structure and function of such wetlands may therefore be susceptible to predicted, human-induced climate warming.

Resumen: Los principales objetivos de la presente investigación son conocer las características estructurales y funcionales del sistema de apoyo social y analizar su relación con el bienestar subjetivo en un colectivo de inmigrantes. La muestra del estudio está formada por 100 marroquíes que cumplimentaron la entrevista de apoyo social ASSIS , la escala de satisfacción con la vida , y una medida sobre percepción de prejuicio étnico. Los resultados obtenidos muestran una escasa presencia de autóctonos en las redes sociales de los marroquíes, siendo los vínculos con otros inmigrantes la principal fuente de apoyo informativo, material y emocional para este grupo de población. Las variables predictoras del bienestar subjetivo son la satisfacción con el apoyo emocional proporcionado por los autóctonos, la satisfacción con el apoyo informativo y la suficiencia de la ayuda facilitada por otros inmigrantes, y la percepción de prejuicio étnico. De este modo, se constata que las dimensiones del apoyo social que inciden de manera positiva sobre el bienestar subjetivo de este colectivo son las de carácter funcional, variando en función del origen, autóctono vs. extranjero, del proveedor de ayuda.

A novel polypeptide, designated o-Lsp-IA, which modulates P-type Ca 2+ channels, was purified from the venom of the spider Geolycosa sp. o-Lsp-IA contains 47 amino acid residues and 4 intramolecular disulfide bridges. It belongs to a group of spider toxins affecting Ca 2+ channels and presumably forms the inhibitor cystine knot (ICK) fold. Peculiar structural features (a cluster of positively charged residues in the C-terminal loop of the peptide and a regular distribution of hydrophobic residues) that may play a decisive role in the o-Lsp-IA mechanism of action were located. Recombinant o-Lsp-IA was produced in prokaryotic expression system and was shown to be structurally and functionally identical to the native toxin. At saturating concentration (10 nM), the peptide clearly slows down the activation kinetics and partially inhibits the amplitude of P-current in rat cerebellar Purkinje neurons. Prominent deceleration of the activation kinetics is manifested as the appearance of a five-fold slower component of the current activation. The specificity of action of o-Lsp-IA on different Ca 2+ channel types was studied in isolated hippocampal neurons of rat. o-Agatoxin IVA completely removed the effect of o-Lsp-IA on the whole-cell Ca 2+ current. Therefore, o-Lsp-IA appears to act specifically on P-type Ca 2+ channels.

The activity of RING finger ubiquitin ligases (E3) is dependent on their ability to facilitate transfer of ubiquitin from ubiquitin-conjugating enzymes (E2) to substrates. The G2BR domain within the E3 gp78 binds selectively and with high affinity to the E2 Ube2g2. Through structural and functional analyses, we determine that this occurs on a region of Ube2g2 distinct from binding sites for ubiquitin-activating enzyme (E1) and RING fingers. Binding to the G2BR results in conformational changes in Ube2g2 that affect ubiquitin loading. The Ube2g2:G2BR interaction also causes an $50-fold increase in affinity between the E2 and RING finger. This results in markedly increased ubiquitylation by Ube2g2 and the gp78 RING finger. The significance of this G2BR effect is underscored by enhanced ubiquitylation observed when Ube2g2 is paired with other RING finger E3s. These findings uncover a mechanism whereby allosteric effects on an E2 enhance E2-RING finger interactions and, consequently, ubiquitylation.

Landscape connectivity is a very recurrent theme in landscape ecology as it is considered pivotal for the long term conservation of any organism's populations. Nevertheless, this complex concept is still surrounded by uncertainty and confusion, largely due to the separation between structural and functional connectivity. Amphibians are the most threatened vertebrates around the globe, in Europe mostly due to habitat alteration, and to their particular life cycle. Pond breeding amphibians are considered to be organised in metapopulations, enhancing the importance of landscape connectivity in this group of animals. We sampled the amphibian species present in two pond groups in Central Western Spain. We applied the graph theory framework to these two pond networks in order to determine the importance of each pond for the entire network connectivity. We related the pond importance for connectivity with the species richness present in each pond. We tested if connectivity (partially) determined the presence of the amphibian species sampled using logistic regression. The results show that the structural connectivity of the pond network impacts on the amphibian species richness pattern and that the importance of the pond for the connectivity of the network is an important factor for the presence of some species. Our results, hence, attest the importance of (structural) landscape connectivity determining the pattern of amphibian (functional) colonization in discrete ponds.