Miracle-dz/UniFAR-FTUs huggingface dataset:
Activity‐dependent changes in temporal components of neurotransmission at the juvenile mouse calyx of Held synapse

The temporal fidelity of synaptic transmission is constrained by the reproducibility of time delays such as axonal conduction delay and synaptic delay, but very little is known about the modulation of these distinct components. In particular, synaptic delay is not generally considered to be modifiable under physiological conditions. Using simultaneous paired patch‐clamp recordings from pre‐ and postsynaptic elements of the calyx of Held synapse, in juvenile mouse auditory brainstem slices, we show here that synaptic activity (20–200 Hz) leads to activity‐dependent increases in synaptic delay and its variance as well as desynchronization of evoked responses. Such changes were most robust at 200 Hz in 2 mm extracellular Ca2+ ([Ca2+]o), and could be attenuated by lowering [Ca2+]o to 1 mm, increasing temperature to 35°C, or application of the GABABR agonist baclofen, which inhibits presynaptic Ca2+ currents (ICa). Conduction delay also exhibited slight activity‐dependent prolongation, but this prolongation was only sensitive to temperature, and not to [Ca2+]o or baclofen. Direct voltage‐clamp recordings of ICa evoked by repeated action potential train template (200 Hz) revealed little jitter in the timing and kinetics of ICa under various conditions, suggesting that increases in synaptic delay and its variance occur downstream of Ca2+ entry. Loading the Ca2+ chelator EGTA‐AM into terminals reduced the progression rate, the extent of activity‐dependent increases in various delay components, and their variance, implying that residual Ca2+ accumulation in the presynaptic nerve terminal induces these changes. Finally, by applying a test pulse at different intervals following a 200 Hz train (150 ms), we demonstrated that prolongation in the various delay components reverses in parallel with recovery in synaptic strength. These observations suggest that a depletion of the readily releasable pool of SVs during high‐frequency activity may downregulate not only synaptic strength but also decrease the temporal fidelity of neurotransmission at this and other central synapses.
Biodegradation of haloacetic acids by bacterial isolates and enrichment cultures from drinking water systems.

Biodegradation is a potentially important loss process for haloacetic acids (HAAs), a class of chlorination byproducts, in water treatment and distribution systems, but little is known about the organisms involved (i.e., identity, substrate range, biodegradation kinetics). In this research, 10 biomass samples (i.e., tap water, distribution system biofilms, and prechlorinated granular activated carbon filters) from nine drinking water systems were used to inoculate a total of thirty enrichment cultures fed monochloroacetic acid (MCAA), dichloroacetic acid (DCAA), or trichloroacetic (TCAA) as sole carbon and energy source. HAA degraders were successfully enriched from the biofilm samples (GAC and distribution system) but rarely from tap water. Half of the MCAA and DCAA enrichment cultures were positive, whereas only one TCAA culture was positive (two were inconclusive). Eight unique HAA-degrading isolates were obtained including several Afipia spp. and a Methylobacterium sp. ; all isolates were members of the phylum Proteobacteria. MCAA, monobromoacetic acid (MBAA), and monoiodoacetic acid (MIAA) were rapidly degraded by all isolates, and DCAA and tribromoacetic (TBAA) were also relatively labile. TCAA and dibromoacetic acid (DBAA)were degraded by only three isolates and degradation lagged behind the other HAAs. Detailed DCAA biodegradation kinetics were obtained for two selected isolates and two enrichment cultures. The maximum biomass-normalized degradation rates (Vm) were 0.27 and 0.97 microg DCAA/ microg protein/h for Methylobacterium fujisawaense strain PAWDI and Afipia felis strain EMD2, respectively, which were comparable to the values obtained for the enrichment cultures from which those organisms were isolated (0.39 and 1.37 microg DCAN/microg protein/h, respectively). The half-saturation constant (Km) values ranged from 4.38 to 77.91 microg DCAA/L and the cell yields ranged from 14.4 to 36.1 mg protein/g DCAA.
Satisfaction of medical students with simulation based learning

Objectives: To evaluate medical students’ satisfaction with simulation based learning strategy (SBL). Methods: A cross-sectional survey was conducted between October and November 2013 at the College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia. All third and fourth year medical students (n=185) both males and females were included. A self-developed questionnaire on the effect of SBL was used. Items included were related to knowledge, skill, environment, resources, and faculty. The questionnaire was validated by an expert reviewer, and the reliability was calculated for all the questionnaire items. Responses were measured on a 5 point Likert-type scale, and statistical analysis was carried out. Results: The response rate for this study was 62% (n=115). The alpha coefficient for all items was 0.73. Overall, respondents from both years’ students were satisfied with teaching strategy, use of mannequins, and learning environment. The challenges reported were lack of skill-laboratories facilities, students’ cooperation, allocated time for skill-laboratories, and knowledge of instructor. There was a small, but significant difference between the satisfaction scores among genders (p=0.001). Whereas no difference was identified between the participants’ scores on satisfaction with SBL and year of education (p=0.62). Conclusion: Although there were few challenges, most of the students were satisfied that SBL improved their knowledge retention, skills, and communication.
Mandibular movements identify respiratory effort in pediatric obstructive sleep apnea.

STUDY OBJECTIVES Obstructive sleep apnea-hypopnea (OAH) diagnosis in children is based on the quantification of flow and respiratory effort (RE). Pulse transit time (PTT) is one validated tool to recognize RE. Pattern analysis of mandibular movements (MM) might be an alternative method to detect RE. We compared several patterns of MM to concomittant changes in PTT during OAH in children with adenotonsillar hypertrophy. METHODS PARTICIPANTS 33 consecutive children with snoring and symptoms/signs of OAH. MEASUREMENTS MMs were measured during polysomnography with a magnetometer device (Brizzy Nomics, Liege, Belgium) placed on the chin and forehead. Patterns of MM were evaluated representing peak to peak fluctuations > 0.3 mm in mandibular excursion (MML), mandibular opening (MMO), and sharp MM (MMS), which closed the mouth on cortical arousal (CAr). RESULTS The median (95% CI) hourly rate of at least 1 MM (MML, or MMO, or MMS) was 18.1 (13.2-36.3) and strongly correlated with OAHI (p = 0.003) but not with central apnea-hypopnea index (CAHI; p = 0.292). The durations when the MM amplitude was > 0.4 mm and PTT > 15 ms were strongly correlated (p < 0.001). The mean (SD) of MM peak to peak amplitude was larger during OAH than CAH (0.9 ± 0.7 mm and 0.2 ± 0.3 mm; p < 0.001, respectively). MMS at the termination of OAH had larger amplitude compared to MMS with CAH (1.5 ± 0.9 mm and 0.5 ± 0.7 mm, respectively, p < 0.001). CONCLUSIONS MM > 0.4 mm occurred frequently during periods of OAH and were frequently terminated by MMS corresponding to mouth closure on CAr. The MM findings strongly correlated with changes in PTT. MM analysis could be a simple and accurate promising tool for RE characterization and optimization of OAH diagnosis in children.
Validation and use of a parametric model for projecting cystic fibrosis survivorship beyond observed data: a birth cohort analysis

Background The current lifetable approach to survival estimation is favoured by CF registries. Recognising the limitation of this approach, we examined the utility of a parametric survival model to project birth cohort survival estimates beyond the follow-up period, where short duration of follow-up meant median survival estimates were indeterminable. Methods Parametric models were fitted to observed survivorship data from the US CF Foundation (CFF) Patient Registry 1980–1994 birth cohort. Model-predicted median survival was estimated. The best fitting model was applied to a Cystic Fibrosis Registry of Ireland dataset to allow an evaluation of the model's ability to estimate predicted median survival. This involved a comparison of birth cohort lifetable predicted and observed (Kaplan–Meier) median survival estimates. Results A Weibull model with main effects of gender and birth cohort was developed using a US CFF dataset (n=13 115) for which median survival was not directly estimable. Birth cohort lifetable predicted median survival for male and female patients born between 1985 and 1994 and surviving their first birthday was 50.9 and 42.4 years respectively. To evaluate the accuracy of a Weibull model in predicting median survival, a model was developed for the 1980–1984 Cystic Fibrosis Registry of Ireland birth cohort (n=243), which had an observed (Kaplan–Meier) median survival of 27.7 years. Model-predicted median survival estimates were calculated using data censored at different follow-up periods. The estimates converged to the true value as length of follow-up increased. Conclusions Accurate prognostic information that is clinically critical for care of patients affected by rare, life-limiting disorders can be provided by parametric survival models. Problems associated with short duration of follow-up for recent birth cohorts can be overcome using this approach, providing better opportunities to monitor survival and plan services locally.
Alcohol is a potent stimulant of immature neuronal networks: implications for fetal alcohol spectrum disorder

Ethanol consumption during development affects the maturation of hippocampal circuits by mechanisms that are not fully understood. Ethanol acts as a depressant in the mature CNS and it has been assumed that this also applies to immature neurons. We investigated whether ethanol targets the neuronal network activity that is involved in the refinement of developing hippocampal synapses. This activity appears during the growth spurt period in the form of giant depolarizing potentials (GDPs). GDPs are generated by the excitatory actions of GABA and glutamate via a positive feedback circuit involving pyramidal neurons and interneurons. We found that ethanol potently increases GDP frequency in the CA3 hippocampal region of slices from neonatal rats. It also increased the frequency of GDP‐driven Ca2+ transients in pyramidal neurons and increased the frequency of GABAA receptor‐mediated spontaneous postsynaptic currents in CA3 pyramidal cells and interneurons. The ethanol‐induced potentiation of GABAergic activity is probably the result of increased quantal GABA release at interneuronal synapses but not enhanced neuronal excitability. These findings demonstrate that ethanol is a potent stimulant of developing neuronal circuits, which might contribute to the abnormal hippocampal development associated with fetal alcohol syndrome and alcohol‐related neurodevelopmental disorders.
Optimal training signals for MIMO OFDM channel estimation

This work presents general classes of optimal training signals for estimation of frequency-selective channels in MIMO OFDM systems. Basic properties of the discrete Fourier transform are used to derive the optimal training signals which minimize the channel estimation mean square error. Both single and multiple OFDM training symbols are considered. Several optimal pilot tone allocations among the transmit antennas are presented and classified as frequency division multiplexing, time division multiplexing, code division multiplexing in frequency-domain, code division multiplexing in time-domain, and combinations thereof. All existing optimal training signals in the literature are special cases of the presented optimal training signals and our designs can be applied to pilot-only schemes as well as pilot-data multiplexed schemes.
Nucleoprotein-RNA Orientation in the Measles Virus Nucleocapsid by Three-Dimensional Electron Microscopy

ABSTRACT Recombinant measles virus nucleoprotein-RNA (N-RNA) helices were analyzed by negative-stain electron microscopy. Three-dimensional reconstructions of trypsin-digested and intact nucleocapsids coupled to the docking of the atomic structure of the respiratory syncytial virus (RSV) N-RNA subunit into the electron microscopy density map support a model that places the RNA at the exterior of the helix and the disordered C-terminal domain toward the helix interior, and they suggest the position of the six nucleotides with respect to the measles N protomer.
Attentional modulation of perceptual grouping in human visual cortex: Functional MRI studies

When presented with a complex visual scene, our visual system has to organize the discrete entities present into useful perceptual units. The current work investigated the neural substrates of perceptual grouping defined by Gestalt laws of proximity and similarity of shape, and whether the neural substrates underlying perceptual grouping are modulated by task relevance and spatial attention. In visual discrimination tasks, subjects identified the orientations of perceptual groups formed by proximity or similarity of local elements or alternatively identified colors of either dots around the grouped stimuli or the fixation cross. Using functional magnetic resonance imaging (fMRI), we identified that the calcarine cortex was involved in proximity grouping but not in the grouping process defined by similarity of shape. Moreover, we showed evidence that the neural correlates of proximity grouping in the calcarine cortex were weakened when the elements were of low task relevance and fell outside an attended area of field. The findings reveal the neural basis for basic grouping operations, as well as illustrating how attention and proximity grouping interact in human visual cortex. Hum Brain Mapp 2005. © 2005 Wiley‐Liss, Inc.
Expression of X‐linked inhibitor‐of‐apoptosis protein in hepatocellular carcinoma promotes metastasis and tumor recurrence

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. Despite significantly improved diagnosis and treatment in recent years, the long‐term therapeutic effect is compromised by the frequent recurrence and metastasis, of which the molecular mechanisms are not fully understood. Our initial studies in established HCC cell lines with different metastatic capabilities indicated a correlation of metastasis with the resistance to apoptosis and therefore the ability to survive in stressed conditions. Subsequent investigation revealed that increased expression of X‐linked inhibitor‐of‐apoptosis protein (XIAP) was correlated with the resistance to apoptosis and enhanced invasiveness in vitro, which could contribute to increased metastatic foci in vivo. Furthermore, we found that nearly 90% of clinical samples from advanced HCC patients expressed high levels of XIAP. Patients with XIAP‐positive tumors had a significantly increased risk of relapse, which resulted from metastasis after total liver resection and orthotopic liver transplantation. Indeed, XIAP expression could be an independent prognostic factor for predicting disease‐free survival rate and overall survival rate of these patients. XIAP expression was also highly correlated with advanced cases that exceeded the Milan criteria and could be a prognostic factor for disease‐free survival in these patients as well. Conclusion: Our studies have shown an important molecule in controlling HCC metastasis, defined a biomarker that can be used to predict HCC recurrence and patient survival after treatment, and suggest that XIAP can be a molecular target subject to intervention to reduce metastasis and recurrence. (HEPATOLOGY 2008;48:497–507.)
Navigating Cultures and Epistemologies in Science and Technology Education

Kurz, Kathleen T. , Ph.D., University of Missouri – St. Louis, 2005. Navigating Cultures and Epistemologies in Science and Technology Education. Major Professors: William C. Kyle, Jr., Ph.D., Joseph L. Polman, Ph.D., Stephen A. Sherblom, Ed.D, and John G. Blake, Ph.D. This investigation focuses on the nexus of science and culture in the lives of marginalized youth in the United States and South Africa. The epistemologies and contextual realities of cross-cultural learner cohorts and their understandings of scientific phenomena are examined. The researcher was a participant observer within the context of the Science, Technology & Culture: Empowering Learners (STC) program, an after-school and school-based collaboration focused upon integrating science, technology and culture. Electronic communication provided a vehicle for dialogue between youth in St. Louis, Missouri, USA and a South African Township. Study findings include documentation of the marginalizing effects of poverty for the United States and South African study participants. Study participants drew upon multiple contexts to form identity. United States and South African learners revealed many ways of knowing as explanatory tools for natural phenomena. Learners maintained multiple epistemologies as explanatory tools after engaging in scientific pedagogical activities. However, belief in multiple epistemologies did not preclude learner trust in scientifically acceptable explanations for natural events. Change was a constant in the experience of study participants. Educators and learners negotiated their changing world through the lenses of their cultural/indigenous understandings. Implications for policy and practice are provided.
Incentive Memory: Evidence the Basolateral Amygdala Encodes and the Insular Cortex Retrieves Outcome Values to Guide Choice between Goal-Directed Actions

Choice between goal-directed actions is determined by the relative value of their consequences. Such values are encoded during incentive learning and later retrieved to guide performance. Although the basolateral amygdala (BLA) and the gustatory region of insular cortex (IC) have been implicated in these processes, their relative contribution is still a matter of debate. Here we assessed whether these structures interact during incentive learning and retrieval to guide choice. In these experiments, rats were trained on two actions for distinct outcomes after which one of the two outcomes was devalued by specific satiety immediately before a choice extinction test. We first confirmed that, relative to appropriate controls, outcome devaluation recruited both the BLA and IC based on activation of the immediate early gene Arc; however, we found that infusion of the NMDAr antagonist ifenprodil into the BLA only abolished outcome devaluation when given before devaluation. In contrast, ifenprodil infusion into the IC was effective whether made before devaluation or test. We hypothesized that the BLA encodes and the IC retrieves incentive value for choice and, to test this, developed a novel sequential disconnection procedure. Blocking NMDAr activation unilaterally in the BLA before devaluation and then contralaterally in the IC before test abolished selective devaluation. In contrast, reversing the order of these infusions left devaluation intact. These results confirm that the BLA and IC form a circuit mediating the encoding and retrieval of outcome values, with the BLA encoding and the IC retrieving such values to guide choice.
An Ionizing Radiation Sensor Using a Pre-Programmed MAHAOS Device

Metal-aluminum oxide–hafnium aluminum oxide–silicon oxide–silicon (hereafter MAHAOS) devices can be candidates for ionizing radiation sensor applications. In this work, MAHAOS devices (SONOS-like structures with high k stack gate dielectric) were studied regarding the first known characterization of the ionization radiation sensing response. The change of threshold voltage VT for a MAHAOS device after gamma ray exposure had a strong correlation to the total ionization dose (TID) of gamma radiation up to at least 5 Mrad TID. In this paper, the gamma radiation response performances of the pre-programmed and virgin (non-pre-programmed) MAHAOS devices are presented. The experimental data show that the change of VT for the pre-programmed MAHAOS device with gamma irradiation is very significant. The data of pre-programmed MAHAOS devices written by 5 Mrad TID of gamma radiation was also stable for a long time with data storage. The sensing of gamma radiation by pre-programmed MAHAOS devices with high k stack gate dielectric reported in this study has demonstrated their potential application for non-volatile ionizing radiation sensing technology in the future.
Genetic polymorphism of platelet glycoprotein Ib.

Platelet glycoprotein (GP) Ib from 131 healthy Japanese was analyzed using SDS-polyacrylamide gel electrophoresis and specific staining with peroxidase-coupled wheat germ agglutinin after it was transferred to nitrocellulose membranes. Four slightly different species of GPIb were observed and designated as A, B, C, and D for glycoproteins with molecular weights of 168,000, 162,000, 159,000, and 153,000 daltons, respectively. The respective gene frequencies were calculated to be . 073, . 011, . 561, and . 355 for A-, B-, C-, D-type GPIb. Portions from each type of GPIb molecule (alpha-chain and glycocalicin) showed heterogeneity with the same molecular weight difference, indicating that the variance would be derived from the polypeptide portion that is exposed to the outer medium. The different types of GPIb were the same with respect to their accessibility to lactoperoxidase, reactivity to lectins, and affinity to TLCK-thrombin. Although Bolin et al reported patients with a bleeding tendency whose platelets have double GPIb bands, here we found that platelets with different GPIb phenotypes showed no significant differences in aggregating activity and platelet retention. Analysis of GPIb phenotype should be important for structural and physiologic studies on GPIb and glycocalicin.
Relationships of Cervical, Thoracic, and Lumbar Bone Mineral Density by Quantitative CT

Purpose The purpose of this work was to compare, using quantitative CT (QCT), vertebral bone mineral density (BMD) in the cervical, thoracic, and lumbar spine in healthy volunteers. Method QCT of the vertebral bodies of C2, C5, T12, and L4 was performed on 50 healthy volunteers (25 women, 25 men; mean age 31.7 years). Trabecular BMD analysis was performed at each level. Results Mean BMDs (mg/cm3 calcium hydroxyapatite) for women and men were highest at C5 (BMD women/men 341.6/300.6 mg/cm3) and C2 (297.2/269.6 mg/cm3) and lowest at T12 (193.1/184.9 mg/cm3) and L4 (186.2/180.1 mg/cm3). The BMD of C2 was statistically significantly different from that of C5, T12, and L4 (p < 0.0001) for both genders. Also, the BMD of C5 differed significantly from that of T12 and L4 (p < 0.0001). The BMD of C5 showed significant gender differences (p = 0.002). Correlation coefficient showed a strong correlation between the BMD of T12 and L4 for both genders (women, r = 0.67; men, r = 0.90). Conclusion Trabecular BMD of C2 and C5 measured by QCT is significantly higher than trabecular BMD of T12 and L4 in nonosteoporotic volunteers of both genders.
Percutaneous hepatic perfusion with melphalan in uveal melanoma: A safe and effective treatment modality in an orphan disease

Metastatic uveal melanoma (UM) carries a poor prognosis; liver is the most frequent and often solitary site of recurrence. Available systemic treatments have not improved outcomes. Melphalan percutaneous hepatic perfusion (M‐PHP) allows selective intrahepatic delivery of high dose cytotoxic chemotherapy.