Miracle-dz/UniFAR-FTUs huggingface dataset:
An Id‐like current that is downregulated by Ca2+ modulates information coding at CA3–CA3 synapses in the rat hippocampus

Voltage‐gated K+ channels localised on presynaptic nerve terminals control information coding by modulating presynaptic firing and synaptic efficacy in target neurones. We found that at CA3–CA3 connections in hippocampal slice cultures, a fast‐activating, slowly inactivating K+ conductance similar to the so‐called delay current (ID) is responsible for the delayed appearance of the first spike upon membrane depolarisation, for action potential repolarisation and for modulation of transmitter release. The Id‐like current was downregulated by intracellular Ca2+, as indicated by the increased delay in the appearance of the first action potential following either the block of Ca2+ flux through voltage‐dependent Ca2+ channels with Cd2+ or replacement of the bathing solution with one devoid of Ca2+. In both cases, this effect was reversed by blocking this conductance with a low concentration of 4‐aminopyridine (4‐AP, 10‐50 μM). Application of 4‐AP shortened the delay to the first spike generation, prevented the effect of Cd2+ and increased the spike duration. The earlier appearance of the first action potential was also observed in the presence of dendrotoxin‐1 (100 nM). In voltage‐clamp experiments larger currents were recorded in the absence of extracellular Ca2+, thus confirming the downregulation of the Id‐like current by Ca2+ due to the positive shift of its inactivation. Spike broadening was associated with an enhancement of synaptic efficacy in target neurones, as assessed by the increase in EPSC amplitude and in the percentage of successes. Moreover, in the presence of 4‐AP, EPSCs appeared with a longer latency and were more scattered. This conductance is therefore crucial for setting the timing and strength of synaptic transmission at CA3–CA3 connections. It is conceivable that switching off ID by increasing intracellular Ca2+ following activity‐dependent processes may facilitate network synchronisation and crosstalk between CA3 pyramidal cells, leading to seizure activity.
Classification : Biological Sciences , Evolution 1 Short Title : Compositional Calling in Pied Babbler 2 3 Meaningful Call Combinations and Compositional Processing in the Southern 4 Pied Babbler 5 6

29 Language’s expressive power is largely attributable to its compositionality: 30 meaningful words are combined into larger/higher-order structures with derived 31 meaning. Despite its importance, little is known regarding the evolutionary origins 32 and emergence of this syntactic ability. Whilst previous research has demonstrated a 33 rudimentary capability to combine meaningful calls in primates, due to a scarcity of 34 comparative data, it is unclear whether analogue forms might also exist outside of 35 primates. Here we address this ambiguity and provide evidence for rudimentary 36 compositionality in the discrete vocal system of a social passerine, the pied babbler 37 (Turdoides bicolor). Natural observations and predator presentations revealed 38 babblers produce acoustically distinct alert calls in response to close, low-urgency 39 threats, and recruitment calls when recruiting group members during locomotion. 40 Upon encountering terrestrial predators both vocalisations are combined into a 41 ‘mobbing-sequence’, potentially to recruit group members in a dangerous situation. 42 To investigate whether babblers process the sequence in a compositional way, we 43 conducted systematic experiments, playing back the individual calls in isolation, as 44 well as naturally occurring and artificial sequences. Babblers reacted most strongly to 45 mobbing-sequence playbacks, showing a greater attentiveness and a quicker approach 46 to the loudspeaker, compared to individual calls or control sequences. We conclude 47 the sequence constitutes a compositional structure, communicating information on 48 both the context and the requested action. Our work supports previous research 49 suggesting combinatoriality as a viable mechanism to increase communicative output, 50 and indicates that the ability to combine and process meaningful vocal structures, a 51 basic syntax, may be more widespread than previously thought. 52
Molecular dynamics simulations of the dinuclear zinc‐β‐lactamase from Bacteroides fragilis complexed with imipenem

Herein, we present results from MD simulations of the Michaelis complex formed between the dizinc β‐lactamase from B. fragilis and imipenem. We considered two catalytically important configurations, which differ in the presence or absence of a hydroxide bridge connecting the two zinc ions in the active site. The structural and dynamical effects induced by substrate binding, the specific roles of the conserved residues and the zinc‐bound water molecules, the near attack conformers of the Michaelis complex, and so forth, are discussed in detail. The relative stability of the two configurations was estimated from QM linear scaling calculations on the enzyme‐substrate complex combined with Poisson‐Boltzmann electrostatic calculations and normal mode calculations. Importantly, we find that the two configurations have similar energies, indicating that these two structures could readily be interchanged, thereby facilitating catalysis. The configuration with the hydroxide bound to the two zinc ions is predicted to be the resting form of the enzyme, while the configuration without the bridge is the reactive form that was found to place the hydroxide in position to attack the carbonyl of the β‐lactam ring. Thus, we propose that the enzyme initiates catalysis by converting from the hydroxide bridge form into the configuration that lacks the hydroxide bridge. This interconversion increases the nucleophilicity of the hydroxide ion and exposes it to the β‐lactam carbonyl, which ultimately facilitates nucleophilic attack. The implications of the observed modes of binding, the possible influence of mutating the Lys184 and Asn193 residues on substrate binding, and the reaction mechanism are also discussed in detail. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1587–1600, 2002
Sequence requirements for encapsidation of deletion mutants and chimeras of human immunodeficiency virus type 1 Gag precursor into retrovirus-like particles

Interacting domains in human immunodeficiency virus type 1 (HIV-1) Gag precursor (Pr55gag) expressed in recombinant baculovirus-infected cells were investigated by three different methods: (i) trans rescue and coencapsidation of C-terminal deletion (amber) Gag mutants and Gag chimeras into retrovirus-like particles in complementation experiments with HIV-1 wild-type (WT) Pr55gag, (ii) Gag-Gag interactions in vitro in Gag ligand affinity blotting assays, and (iii) quantitative immunoelectron microscopy of retrovirus-like Gag particles, using a panel of monoclonal antibodies to probe the epitope accessibility of encapsidated HIV-1 WT Pr55gag. Four discrete regions, within residues 210 to 241, 277 to 306 (major homology region), and 307 to 333 in the capsid (CA) protein and residues 358 to 374 at the CA-spacer peptide 2 (sp2) junction, were found to have a significant influence on Gag trans-packaging efficiency. A fifth region, within residues 375 to 426, overlapping the sp2-nucleocapsid (NC) protein junction and most of the NC, seemed to be essential for stable inter-Gag binding in vitro. The coincidence of the two regions from 358 to 374 and 375 to 426 with an immunologically silent domain in WT Gag particles suggested that they could participate in direct Gag interactions.
Prevalence and Pattern of Malaria Parasitaemia among Under-Five Febrile Children Attending Paediatric Out-Patient Clinic at University of Maiduguri Teaching Hospital, Maiduguri

Background: Malaria has remained a major public health problem in Nigeria with the under-five aged children and pregnant women being the most affected. The local epidemiological profile of the disease is dynamic owing to the continuous variation in the various determinants and hence the need for periodic re-evaluation. We aim to determine the prevalence of malaria parasitaemia among the under -five aged children and the effect of various determinants. Material and Method: In this cross-sectional study, 433 outpatients aged below 5 years with fever or history of fever in the previous 72 hours were enrolled. Relevant information was obtained and recorded using a questionnaire. Thick and thin films were prepared from a finger or heel prick for each of the patients and subjected to microscopy. Result: The prevalence of malaria parasitaemia was 27.7%. Age, sex, nutritional status, socioeconomic class, temperature at presentation as well as ownership of insecticide treated nets had no significant effect on the prevalence of malaria (p>0.05). Only P. falciparum was seen in all the positive slides. The parasite density was generally low with 48.3% having parasite densities below 100/μl and only 7.5% had parasite density of ≥1000/μl. Parasite density increased significantly with increasing age (p=0041). Nutritional status as well as other studied factors had no significant effect on parasite density (p>0.05). Conclusion and Recommendation : Prevalence of malaria infection was high in the population studied. It is characterized by low density parasitaemia and hence the need to interpret negative results with caution. Age, gender, socio-economic and nutritional status, temperature at presentation as well as ownership of ITN had no significant effect on prevalence of malaria parasitaemia. There is need to strengthen and scale up various malaria control programs while ensuring proper implementations of programs and activities through effective monitoring and evaluation. Keywords: Prevalence, Pattern, Malaria, Parasitaemia, Under-five Febrile Children, Outpatient Clinic
Attitudes and factors affecting research utilization.

PROBLEM The gap between nursing research findings and their application in practice, particularly in rural areas. METHODS A descriptive-correlational study design focused on the attitude of nurses (N = 106) in rural practice setting towards nursing research and the relationship between their attitudes and other factors. FINDINGS Fewer than a quarter of the nurses in this study had favorable attitudes toward research. Attitudes and interest varied with levels of education and position. Also, the isolation of rural nurses from nurse researchers creates a peculiar barrier to research utilization. CONCLUSION The influence of nurse educators/researchers and administrators cannot be overemphasized. Nurse leaders need to perceive nursing research as the base for evidence-based practice, and enhance the utilization of scientific evidence in practice settings.
Pseudo reaction kinetics of organic degradation products in dilute‐acid‐catalyzed corn stover pretreatment hydrolysates

A variety of degradation products are produced upon pretreatment of lignocellulosic biomass with dilute acid. To date, the complexity of these samples has significantly limited the scope of efforts to perform summative analyses of degradation products. Qualitative and quantitative interrogation of hydrolysates is also paramount to identifying potential correlations between pretreatment chemistry and microbial inhibition in downstream bioconversion processes. A recently developed reversed‐phase high performance liquid chromatography technique with UV detection has been applied to perform quantitative assessments of a variety of hydrolysate components as a function of pretreatment time and temperature. Correlations of product concentrations to the pretreatment severity function indicate differing responses of various compounds to the kinetic influences of temperature and reaction time. Of the compounds measured, four demonstrated initial accumulation rates were sufficiently linear over the time period tested to enable determination of activation energy Ea. All four compounds appear to demonstrate higher Ea than that assumed in the commonly applied severity function. Overall accumulation trends for most compounds indicated similar under‐estimation of apparent activation energy by the severity function. Biotechnol. Bioeng. 2007;98: 1135–1145. © 2007 Wiley Periodicals, Inc.
Learning to teach with videoconferencing in primary foreign language classrooms

Abstract This qualitative study investigates the relationship between learning opportunities and teacher cognition in the context of a videoconferencing (VC) project for foreign languages (FL) in French primary schools. Six generalist primary teachers were followed throughout the initial six-month stage of the initiative, and data were collected from learners, teachers, and trainers via questionnaire, video and audio recordings of class and feedback sessions, online teacher and trainer discussion, and video-stimulated recall interviews. Interview data revealed distinct teacher profiles involving differences in orientation to teaching and the teacher, learning and learners, and technology. These profiles corresponded to different teaching strategies and resulted in varying patterns of learner interaction in VC sessions. Teachers’ comments showed them to be guided by general rather than FL-specific pedagogical principles, and pedagogical concerns frequently intersected with technical issues as teachers learned to exploit the new VC technology. While most teachers valued spontaneous FL interaction as a key VC affordance, the filmed sessions revealed little unplanned learner-learner communication. This finding is related to teachers’ views of second language acquisition as product rather than a process; for more learner-centred teachers, spontaneity was affected by rehearsal, and for more teacher-oriented practitioners, sustained teacher intervention influenced patterns of learner participation. In addition to these classroom findings, the study highlights the value of this type of participant research in facilitating the exchange of resources and expertise, classroom video footage, and participants’ comments and queries, and thus contributing to professional development in CALL and CMC-based teacher education.
Enabling automated magnetic resonance imaging-based targeting assessment during dipole field navigation

The magnetic navigation of drugs in the vascular network promises to increase the efficacy and reduce the secondary toxicity of cancer treatments by targeting tumors directly. Recently, dipole field navigation (DFN) was proposed as the first method achieving both high field and high navigation gradient strengths for whole-body interventions in deep tissues. This is achieved by introducing large ferromagnetic cores around the patient inside a magnetic resonance imaging (MRI) scanner. However, doing so distorts the static field inside the scanner, which prevents imaging during the intervention. This limitation constrains DFN to open-loop navigation, thus exposing the risk of a harmful toxicity in case of a navigation failure. Here, we are interested in periodically assessing drug targeting efficiency using MRI even in the presence of a core. We demonstrate, using a clinical scanner, that it is in fact possible to acquire, in specific regions around a core, images of sufficient quality to perform this task.
Targeting the Ion Channel Kv1.3 with Scorpion Venom Peptides Engineered for Potency, Selectivity, and Half-life

Background: The identification of highly selective Kv1.3 blockers has been challenging. Results: We have engineered scorpion venom peptide fusion proteins to generate potent, selective Kv1.3 inhibitors with long in vivo half-lives. Conclusion: These Kv1.3 inhibitor fusion proteins may have potential for the treatment of autoimmune diseases. Significance: Our results support an emerging approach to generating subtype selective therapeutic ion channel inhibitors. Ion channels are an attractive class of drug targets, but progress in developing inhibitors for therapeutic use has been limited largely due to challenges in identifying subtype selective small molecules. Animal venoms provide an alternative source of ion channel modulators, and the venoms of several species, such as scorpions, spiders and snails, are known to be rich sources of ion channel modulating peptides. Importantly, these peptides often bind to hyper-variable extracellular loops, creating the potential for subtype selectivity rarely achieved with small molecules. We have engineered scorpion venom peptides and incorporated them in fusion proteins to generate highly potent and selective Kv1.3 inhibitors with long in vivo half-lives. Kv1.3 has been reported to play a role in human T cell activation, and therefore, these Kv1.3 inhibitor fusion proteins may have potential for the treatment of autoimmune diseases. Our results support an emerging approach to generating subtype selective therapeutic ion channel inhibitors.
Early Experience with 3-T Magnetic Resonance Tractography in the Surgery of Cerebral Arteriovenous Malformations in and around the Visual Pathway

OBJECTIVE: To evaluate of the role of magnetic resonance (MR) tractography on the optic radiation with a 3-T MR unit in the surgery of cerebral arteriovenous malformation (AVM) in and around the visual pathway. METHODS: Of the 322 patients with cerebral AVMs admitted to our clinic between 1978 and 2005, a study of MR tractography was made on 29 patients. Ten of those patients had AVMs in and around the visual pathway and were included in this study. There were two men and eight women ranging in age from 15 to 64 years (mean age, 34.5 ± 14.8 yr). All of the patients underwent 3-T tractography of optic radiation (OR) and neuro-ophthalmologic evaluation. Four of the 10 patients underwent surgical resection of the AVM. A postoperative 3-T MR study and a neuro-ophthalmologic evaluation was performed 1 month after surgery in most patients. RESULTS: The preoperative patients for whom tractography demonstrated a continuous bundle of OR from the medial temporal region to the primary visual cortex had minimal or no visual field loss, whereas the patients for whom the tractography did not show a continuous bundle of OR had significant visual loss. The patients for whom tractography in the postoperative study demonstrated a bundle of OR experienced no postoperative deterioration of the visual field loss, whereas the patients for whom tractography did not demonstrate a bundle of OR exhibited significant visual field loss. CONCLUSION: This technique is thought to be useful in confirming the integrity of and localizing deviated tract and in evaluating the surgical risk, especially for nonhemorrhagic AVMs in and around the visual pathways, taking some limitations of this method into consideration.
Comparison of ultraviolet light-emitting diodes and low-pressure mercury-arc lamps for disinfection of water

ABSTRACT Ultraviolet (UV) light-emitting diodes (LEDs) emitting at 260 nm were evaluated to determine the inactivation kinetics of bacteria, viruses, and spores compared to low-pressure (LP) UV irradiation. Test microbes were Escherichia coli B, a non-enveloped virus (MS-2), and a bacterial spore (Bacillus atrophaeus). For LP UV, 4-log10 reduction doses were: E. coli B, 6.5 mJ/cm2; MS-2, 59.3 mJ/cm2; and B. atrophaeus, 30.0 mJ/cm2. For UV LEDs, the 4-log10 reduction doses were E. coli B, 6.2 mJ/cm2; MS-2, 58 mJ/cm2; and B. atrophaeus, 18.7 mJ/cm2. Microbial inactivation kinetics of the two UV technologies were not significantly different for E. coli B and MS-2, but were different for B. atrophaeus spores. UV LEDs at 260 nm are at least as effective for inactivating microbes in water as conventional LP UV sources and should undergo further development in treatment systems to disinfect drinking water.
Observations on the structure of myelin lacking the major proteolipid protein

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Evaluation of the phagocitary capacity of the mononuclear system in an experimental model of obstructive jaundice employing Tc- 99m Escherichia coli

Infections and endotoxemia continue to be the principal causes of morbidity and mortality of patients with obstructions of the bile duct. The objective of the present work was the investigation of the phagocitary capacity of the mononuclear system in an experimental model of obstructive jaundice utilizing Tc-99m E.coli. The levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) were significantly higher in jaundiced rats than in the control animals (p < 0.001). The liver of the jaundiced animals presented a significant reduction in Tc-99m E.coli uptake when compared to the controls (p < 0.001). The data also showed that there was a significant increase in the uptake of Tc-99m E.coli by the lungs of jaundiced rats (p < 0.01). The histological analyses of the liver of jaundiced rats showed an intense and diffuse proliferation of the bile ducts and an intensified polyploidy of the hepatocytes (mean volume = 843 µm3), but no significant alterations were observed in the lungs of either group. This dates could contribute to a better understanding of the mechanisms involved in cases of bacteremia, renal failure and pulmonary dysfunction observed in clinical analyses of obstructive jaundice.