Miracle-dz/UniFAR-FTUs huggingface dataset:
Hyperpolarization-activated cation current (Ih) in neurons of the medial nucleus of the trapezoid body: voltage-clamp analysis and enhancement by norepinephrine and cAMP suggest a modulatory mechanism in the auditory brain stem.

1. Principal cells in the medial nucleus of the trapezoid body (MNTB) are part of a circuit in the superior olivary complex (SOC) that processes binaural information important for sound localization. MNTB cells have two voltage-dependent currents active near rest that contribute to these cells' highly nonlinear membrane properties and shape their responses to synaptic input. One of these currents, a low-threshold, 4-aminopyridine (4-AP)-sensitive K+ current, has been studied previously under current clamp. Using the single-electrode voltage-clamp technique, we have investigated the other of these currents, a hyperpolarization-activated, mixed cation current (Ih), in brain slices of the rat SOC. 2. Ih is responsible for a prominent "sag" in the voltage response to a steady hyperpolarizing current recorded under current clamp in MNTB cells. In voltage-clamp recordings, hyperpolarizing voltage steps from the resting potential elicited a large inward current that activated and deactivated with biexponential kinetics. Activation time constants were voltage dependent, with tau 1 and tau 2 = 246 and 1620 ms at -75 mV and 107 and 560 ms at -100 mV. 3. Ih was blocked by 1-5 mM cesium and had a reversal potential of -43 mV. Steady-state activation curves derived from tail currents yielded a half-activation voltage of -75.7 mV and slope factor of 5.7 mV, corresponding to < 10% activation of Ih at rest. 4. Application of norepinephrine (15-20 microM) or 8-bromoadenosine 3',5'-cyclic monophosphate (8-Br-cAMP) (1 mM) caused a depolarizing shift in the steady-state activation curve and decreased the activation time constants. The shift in the activation curve resulted in a large increase in the activation of Ih at rest, an inward shift in the holding current, and an increase in the resting membrane conductance. In current-clamp recordings, this increase in the resting activation level of Ih resulted in membrane depolarization of 2-3 mV in the absence of 4-AP, and 5-10 mV in the presence of 4-AP, an increase in the input conductance, and a reduction in the voltage sag in response to hyperpolarizing currents. 5. The resulting change in the resting point of MNTB cells exposed to norepinephrine or 8-Br-cAMP is likely to alter the responses of these cells to synaptic input, both via the direct effect on the resting membrane conductance and by changing the activation of the low-threshold, 4-AP-sensitive potassium current. (ABSTRACT TRUNCATED AT 400 WORDS)
A study of ESD protection for helical-scan tape heads

A GMR head for a helical-scan tape system is affected by two sorts of electrostatic discharges (ESD): one is from an electrified wire to a terminal of the head and another is from a tape mike to s GMR sensor. A generally available coated wire is electrified on its suface and can induce the charge on the copper core. When the wire is touching the GMR head terminal, the discharge current can damage the sensor of GMR head. Four kind of wires were meafllred with three different lengths, Resin coated wires were electrified fiom 20V to ova 1kV. The peak cmnt dischargng ta the GMR head reached from 100mA to over 1000mA.A resin coated wire as short as 5cm damaged the GMR head. Only enameled wire can be used because of my charge and any discharge current were not observed. When an ionizer is wed for neutralizing the tribocharge on the surface of the wire, the charge remaining on the copper core depends on the effectiveness of the neutralizing process. In order to avoid ESD from a tape suface to a GMR sensor, the resisitive ferrite substrate was developed to bypass the ESD current.
Reduced vesicular storage of dopamine exacerbates methamphetamine‐induced neurodegeneration and astrogliosis

The vesicular monoamine transporter 2 (VMAT2) controls the loading of dopamine (DA) into vesicles and therefore determines synaptic properties such as quantal size, receptor sensitivity, and vesicular and cytosolic DA concentration. Impairment of proper DA compartmentalization is postulated to underlie the sensitivity of DA neurons to oxidative damage and degeneration. It is known that DA can auto‐oxidize in the cytosol to form quinones and other oxidative species and that this production of oxidative stress is thought to be a critical factor in DA terminal loss after methamphetamine (METH) exposure. Using a mutant strain of mice (VMAT2 LO), which have only 5–10% of the VMAT2 expressed by wild‐type animals, we show that VMAT2 is a major determinant of METH toxicity in the striatum. Subsequent to METH exposure, the VMAT2 LO mice show an exacerbated loss of dopamine transporter and tyrosine hydroxylase (TH), as well as enhanced astrogliosis and protein carbonyl formation. More importantly, VMAT2 LO mice show massive argyrophilic deposits in the striatum after METH, indicating that VMAT2 is a regulator of METH‐induced neurodegeneration. The increased METH neurotoxicity in VMAT2 LO occurs in the absence of any significant difference in basal temperature or METH‐induced hyperthermia. Furthermore, primary midbrain cultures from VMAT2 LO mice show more oxidative stress generation and a greater loss of TH positive processes than wild‐type cultures after METH exposure. Elevated markers of neurotoxicity in VMAT2 LO mice and cultures suggest that the capacity to store DA determines the amount of oxidative stress and neurodegeneration after METH administration.
Microsporidiosis: current status

Purpose of reviewMicrosporidiosis is an emerging and opportunistic infection associated with a wide range of clinical syndromes in humans. This review highlights the research on microsporidiosis in humans during the previous 2 years. Recent findingsThe reduced and compact microsporidian genome has generated much interest for better understanding the evolution of these parasites, and comparative molecular phylogenetic studies continue to support a relationship between the microsporidia and fungi. Through increased awareness and improved diagnostics, microsporidiosis has been identified in a broader range of human populations that, in addition to persons with HIV infection, includes travelers, children, organ transplant recipients, and the elderly. SummaryEffective commercial therapies for Enterocytozoon bieneusi, the most common microsporidian species identified in humans, are still lacking, making the need to develop tissue culture and small animal models increasingly urgent. Environmental transport modeling and disinfection strategies are being addressed for improving water safety. Questions still exist about whether microsporidia infections remain persistent in asymptomatic immune-competent individuals, reactivate during conditions of immune compromise, or may be transmitted to others at risk, such as during pregnancy or through organ donation. Reliable serological diagnostic methods are needed to supplement polymerase chain reaction or histochemistry when spore shedding may be sporadic.
Human Immunodeficiency Virus Type 1 Transductive Recombination Can Occur Frequently and in Proportion to Polyadenylation Signal Readthrough

ABSTRACT One model for retroviral transduction suggests that template switching between viral RNAs and polyadenylation readthrough sequences is responsible for the generation of acute transforming retroviruses. For this study, we examined reverse transcription products of human immunodeficiency virus (HIV)-based vectors designed to mimic postulated transduction intermediates. For maximization of the discontinuous mode of DNA synthesis proposed to generate transductants, sequences located between the vectors' two long terminal repeats (vector “body” sequences) and polyadenylation readthrough “tail” sequences were made highly homologous. Ten genetic markers were introduced to indicate which products had acquired tail sequences by a process we term transductive recombination. Marker segregation patterns for over 100 individual products were determined, and they revealed that more than half of the progeny proviruses were transductive recombinants. Although most crossovers occurred in regions of homology, about 5% were nonhomologous and some included insertions. Ratios of encapsidated readthrough and polyadenylated transcripts for vectors with wild-type and inactivated polyadenylation signals were compared, and transductive recombination frequencies were found to correlate with the readthrough transcript prevalence. In assays in which either vector body or tail could serve as a recombination donor, recombination between tail and body sequences was at least as frequent as body-body exchange. We propose that transductive recombination may contribute to natural HIV variation by providing a mechanism for the acquisition of nongenomic sequences.
Emodin ameliorates glucose-induced matrix synthesis in human peritoneal mesothelial cells.

UNLABELLED Emodin ameliorates glucose-induced matrix synthesis in human peritoneal mesothelial cells. Prolonged exposure of human peritoneal mesothelial cells (HPMC) to high glucose concentrations in peritoneal dialysate is the principal factor leading to matrix accumulation and thickening of the peritoneal membrane, accompanied by progressive deterioration of transport functions. These changes are mediated in part through protein kinase C (PKC) activation and the induction of transforming growth factor-beta 1 (TGF-beta 1). Emodin (3-methyl-1,6,8 trihydroxyanthraquinone) has previously been demonstrated to reduce cell proliferation and fibronectin synthesis in cultured mesangial cells. How emodin modulates glucose-induced abnormalities in HPMC has not been elucidated and thus constitutes the theme of this study. METHODS We investigated the effects of emodin on the expression of PKC alpha, TGF-beta 1, fibronectin, and collagen type I in HPMC, and its effects on HPMC proliferation under physiologic (5 mmol) or high (30 mmol) glucose concentrations. RESULTS Exposure of HPMC cultured with 5 mmol or 30 mmol D-glucose to emodin (20 microg/mL) resulted in an initial lag of proliferation by 2.3 to 2.7 days, but did not affect cell viability or morphology at confluence. D-glucose (30 mmol) induced TGF-beta 1 secretion in a time-dependent manner (3.72 +/- 0.29 and 4.30 +/- 0.50 pg/microg cellular protein at 24 hours and 48 hours respectively, compared to 2.13 +/- 0.23 and 2.65 +/- 0.32 pg/microg cellular protein at 24 hours and 48 hours, respectively for 5 mmol glucose; P < 0.001 at both time points). Such induction was ameliorated by emodin (20 microg/mL) (TGF-beta 1 concentration 2.25 +/- 0.15 and 2.96 +/- 0.33 pg/microg cellular protein at 24 hours and 48 hours, respectively, in the presence of emodin and 30 mmol D-glucose; P < 0.001 compared to 30 mmol D-glucose alone at both time points). Induction of TGF-beta 1 synthesis by 30 mmol D-glucose was associated with induction of PKC alpha, phosphorylation of cAMP-responsive element binding protein (CREB) and activating transcription factor-1 (ATF-1), and increased fibronectin and type I collagen translation. Emodin abrogated all these effects of concentrated glucose. Immunohistochemical staining showed that 30 mmol D-glucose induced cytoplasmic, perinuclear, and extracellular fibronectin and type I collagen expression by HPMC. Emodin reduced 30 mmol D-glucose-induced cytoplasmic and extracellular matrix synthesis to near basal levels. CONCLUSION Our findings demonstrate that emodin ameliorates the undesirable effects of concentrated glucose on HPMC via suppression of PKC activation and CREB phosphorylation, and suggest that emodin may have a therapeutic potential in the prevention or treatment of glucose-induced structural and functional abnormalities in the peritoneal membrane.
Inside‐out Z rings – constriction with and without GTP hydrolysis

The bacterial tubulin homologue FtsZ forms a ring‐like structure called the Z ring that drives cytokinesis. We showed previously that FtsZ–YFP–mts, which has a short amphipathic helix (mts) on its C terminus that inserts into the membrane, can assemble contractile Z rings in tubular liposomes without any other protein. Here we study mts–FtsZ–YFP, where the membrane tether is switched to the opposite side of the protofilament. This assembled ‘inside‐out’ Z rings that wrapped around the outside surface of tubular liposomes. The inside‐out Z rings were highly dynamic, and generated a constriction force that squeezed the tubular liposomes from outside. This is consistent with models where the constriction force is generated by curved protofilaments bending the membrane. We used this system to test how GTP hydrolysis by FtsZ is involved in Z‐ring constriction. Without GTP hydrolysis, Z rings could still assemble and generate an initial constriction. However, the constriction quickly stopped, suggesting that Z rings became rigidly stabilized in the absence of GTP hydrolysis. We propose that remodelling of the Z ring, mediated by GTP hydrolysis and exchange of subunits, is necessary for the continuous constriction.
Natural Balance of Multicell Converters: The Two-Cell Case

The multicell converter topology is said to possess a natural voltage balancing property. This paper is the first of a two-part series in which multicell converters are modelled for the general case of p-cells. This paper focuses on the development of the natural balancing theory for the two-cell case. An understanding of the two-cell case is fundamental to understanding the general balancing theory. The switching functions used in switching these converters are mathematically analyzed. Equivalent circuits are derived and presented. The switching and balancing properties of these converters are mathematically analyzed. The main conclusion of the analysis is that the natural balancing of these converters are influenced by three factors namely, the harmonic content of the reference waveform, the switching frequency and the load impedance. Mathematical tools are presented that can help designers to predict if balancing problems would occur for a particular set of operating conditions. As a result of the detailed understanding of the balancing mechanism that is gained through this theory it is shown that by adding a balance booster, the load impedance can be manipulated to improve the natural balancing of the converter. Simulation results are included to verify the presented balance theory and properties
Behavioral assessment of acoustic parameters relevant to signal recognition and preference in a vocal fish.

Acoustic signal recognition depends on the receiver's processing of the physical attributes of a sound. This study takes advantage of the simple communication sounds produced by plainfin midshipman fish to examine effects of signal variation on call recognition and preference. Nesting male midshipman generate both long duration (> 1 min) sinusoidal-like "hums" and short duration "grunts. " The hums of neighboring males often overlap, creating beat waveforms. Presentation of humlike, single tone stimuli, but not grunts or noise, elicited robust attraction (phonotaxis) by gravid females. In two-choice tests, females differentiated and chose between acoustic signals that differed in duration, frequency, amplitude, and fine temporal content. Frequency preferences were temperature dependent, in accord with the known temperature dependence of hum fundamental frequency. Concurrent hums were simulated with two-tone beat stimuli, either presented from a single speaker or produced more naturally by interference between adjacent sources. Whereas certain single-source beats reduced stimulus attractiveness, beats which resolved into unmodulated tones at their sources did not affect preference. These results demonstrate that phonotactic assessment of stimulus relevance can be applied in a teleost fish, and that multiple signal parameters can affect receiver response in a vertebrate with relatively simple communication signals.
Study of the T16189C variant and mitochondrial lineages in Tunisian and overall Mediterranean region

Abstract The mitochondrial DNA (mtDNA) variant T16189C has been investigated in several metabolic diseases. In this study, we aimed to estimate the frequency of the T16189C variant in Tunisian and other Mediterranean populations and to evaluate the impact of this variant on the phylogeny of Mediterranean populations. Blood sample of 240 unrelated Tunisian subjects were recruited from several Tunisian localities. The hypervariable region 1 of the mtDNA were amplified and sequenced. Additional sequences (N = 4921) from Mediterranean populations were compiled from previous studies. The average frequency of T16189C variant in Tunisia (29%) is similar to that observed in North African and Near Eastern populations. Our findings showed positive correlation of the T16189C variant with Sub-Saharan and North African lineages, while a negative correlation was found with the Eurasian haplogroups, reaching its maximum with the Eurasian haplogroup H. The principal component analyses showed a high internal heterogeneity between Tunisian localities. At the Mediterranean scale, Tunisians are closer to North African (Algerian and Moroccan) and Near Eastern populations (Syrians and Palestinians) than to Europeans.
The Process of Tholin Formation in Titan's Upper Atmosphere

Titan's lower atmosphere has long been known to harbor organic aerosols (tholins) presumed to have been formed from simple molecules, such as methane and nitrogen (CH4 and N2). Up to now, it has been assumed that tholins were formed at altitudes of several hundred kilometers by processes as yet unobserved. Using measurements from a combination of mass/charge and energy/charge spectrometers on the Cassini spacecraft, we have obtained evidence for tholin formation at high altitudes (∼1000 kilometers) in Titan's atmosphere. The observed chemical mix strongly implies a series of chemical reactions and physical processes that lead from simple molecules (CH4 and N2) to larger, more complex molecules (80 to 350 daltons) to negatively charged massive molecules (∼8000 daltons), which we identify as tholins. That the process involves massive negatively charged molecules and aerosols is completely unexpected.
Circuitry and role of substance P‐immunoreactive neurons in the primate retina

In this paper, we extend our previous light microscopic (LM) study of substance P (SP)‐containing amacrine and ganglion cell types of the human retina (Cuenca et al. [1995] J. Comp. Neurol. 356:491–504) to an electron microscopic (EM) and confocal‐imaging study in order to reveal synaptic circuitry and putative input and output neurons. SP‐immunoreactive (‐IR) amacrine cells in primate retina are typically wide‐field cells with large cell bodies occurring in normal or displaced positions relative to the inner plexiform layer (IPL). Their main dendrites bear many spines and are monostratified in stratum 3 (S3) of the IPL. Axon‐like processes arise from dendrites close to the cell body and run for hundreds of microns at the same level as the dendrites, thus forming a relatively dense plexus in S3 of the IPL. SP‐IR axon processes also climb to S1 to surround some amacrine cell bodies, and others pass into the outer plexiform layer (OPL). Still other axons run down to the ganglion cell layer, where they encircle SP‐IR ganglion cells and pass on to end in the nerve fiber layer. The SP‐IR ganglion cell types have large cell bodies (20–22 μm diameter) and dendrites that costratify in S3 among the SP‐IR amacrine cell processes.
Cortisol levels of infants in center care across the first year of life: links with quality of care and infant temperament

Abstract Cortisol concentrations of older children in childcare centers have been found to be higher than at home. This study focuses on infant cortisol in childcare centers throughout the first year of life, and aims to investigate whether inter-individual differences can be explained by temperament, the quality of maternal behavior, and the quality of center care. Sixty-four infants were followed for 9 months after entering care at 3 months of age. Salivary samples were taken at 10.00 h and 16.00 h in center care (in post-entry weeks 1, 2, 3, 4, 8, 12, 16, 24, and 36) and at home (in post-entry weeks 1, 24, and 36). Prior to entry, mothers completed a temperament questionnaire and the quality of maternal behavior (sensitivity and cooperation) was observed during routine bathing sessions. Subsequently, the infants were visited three times at center care to observe the quality of infant’s interactive experiences with their professional caregiver. Longitudinal regression models showed that both morning and afternoon cortisol were higher in center care compared to home. Longitudinal regression models showed that infants receiving higher quality of maternal behavior displayed higher morning cortisol in center care, compared to infants receiving lower quality of maternal behavior. Higher quality of maternal behavior was also related to higher afternoon cortisol in center care, but only in infants high in negative emotionality. Center care quality was not related to cortisol. In sum, young infants show higher cortisol concentrations in center care that are related to infant temperament and quality of maternal behavior at home.
Viral Respiratory Infection and the Link to Asthma

Viral respiratory infections are closely associated with wheezing illnesses and exacerbations of asthma throughout childhood, and yet there are a number of remaining questions pertaining to the specific nature of this relationship. Infection with an expanding list of respiratory viruses is an important cause of acute wheezing in infancy, and viruses are detected in most exacerbations of asthma throughout childhood. Furthermore, infants who develop severe viral respiratory infections are more likely to have asthma later in childhood. There has been progress in understanding the pathogenesis of viral respiratory illnesses, and this has led to new insights into how these processes might differ in asthma. Several host factors, including respiratory allergy and virus-induced interferon responses, modify the risk of virus-induced wheezing. In the absence of effective antiviral therapies, treatment of virus-induced wheezing and exacerbations of asthma can be challenging, and studies evaluating current treatment strategies are reviewed. Understanding the host-pathogen interactions that determine the severity of respiratory illnesses and long-term sequelae is likely to be of great help in identifying at-risk individuals, and in designing new and more effective treatments.