Miracle-dz/UniFAR-FTUs huggingface dataset:
Autonomic Control of Cardiac Action Potentials: Role of Potassium Channel Kinetics in Response to Sympathetic Stimulation

IKs, the slowly activating component of the delayed rectifier current, plays a major role in repolarization of the cardiac action potential (AP). Genetic mutations in the &agr;- (KCNQ1) and &bgr;- (KCNE1) subunits of IKs underlie Long QT Syndrome type 1 and 5 (LQT-1 and LQT-5), respectively, and predispose carriers to the development of polymorphic ventricular arrhythmias and sudden cardiac death. &bgr;-adrenergic stimulation increases IKs and results in rate dependent AP shortening, a control system that can be disrupted by some mutations linked to LQT-1 and LQT-5. The mechanisms by which IKs regulates action potential duration (APD) during &bgr;-adrenergic stimulation at different heart rates are not known, nor are the consequences of mutation induced disruption of this regulation. Here we develop a complementary experimental and theoretical approach to address these questions. We reconstituted IKs in CHO cells (ie, KCNQ1 coexpressed with KCNE1 and the adaptator protein Yotiao) and quantitatively examined the effects of &bgr;-adrenergic stimulation on channel kinetics. We then developed theoretical models of IKs in the absence and presence of &bgr;-adrenergic stimulation. We simulated the effects of sympathetic stimulation on channel activation (speeding) and deactivation (slowing) kinetics on the whole cell action potential under different pacing conditions. The model suggests these kinetic effects are critically important in rate-dependent control of action potential duration. We also investigate the effects of two LQT-5 mutations that alter kinetics and impair sympathetic stimulation of IKs and show the likely mechanism by which they lead to tachyarrhythmias and indicate a distinct role of IKS kinetics in this electrical dysfunction. The full text of this article is available online at http://circres.ahajournals. org.
Neural Integration of Peripheral Signals Implicated in the Control of Energy Homeostasis and Metabolism Mechanisms mediating renal sympathetic activation to leptin in obesity

Morgan DA, Thedens DR, Weiss R, Rahmouni K. Mechanisms mediating renal sympathetic activation to leptin in obesity. Am J Physiol Regul Integr Comp Physiol 295: R1730–R1736, 2008. First published September 24, 2008; doi:10.1152/ajpregu.90324. 2008. — Leptin plays a critical role in the control of energy homeostasis. The sympathetic cardiovascular actions of leptin have emerged as a potential link between obesity and hypertension. We previously demonstrated that in mice, modest obesity induced by 10 wk of a high-fat diet is associated with preservation of leptin ability to increase renal sympathetic nerve activity (SNA) despite the resistance to the metabolic effects of leptin. Here, we examined whether selective leptin resistance exists in mice with late-stage diet-induced obesity (DIO) produced by 20 wk of a high-fat diet. The decrease in food intake and body weight induced by intraperitoneal or intracerebroventricular injection of leptin was significantly attenuated in the DIO mice. Regional SNA responses to intravenous leptin were also attenuated in DIO mice. In contrast, intracerebroventricularly administered leptin caused contrasting effects on regional SNA in DIO mice. Renal SNA response to intracerebroventricular leptin was preserved, whereas lumbar and brown adipose tissue SNA responses were attenuated. Intact renal SNA response to leptin combined with the increased cerebrospinal fluid leptin levels in DIO mice represents a potential mechanism for the adverse cardiovascular consequences of obesity. Lastly, we examined the role of phosphoinositol-3 kinase (PI3K) and melanocortin receptors (MCR) in mediating the preserved renal SNA response to leptin in obesity. Presence of PI3K inhibitor (LY294002) or MC3/4R antagonist (SHU9119) significantly attenuated the renal SNA response to leptin in DIO and agouti obese mice. Our results demonstrate the importance of PI3K and melanocortin receptors in the transduction of leptin-induced renal sympathetic activation in obesity.
High-Speed Integrated Visible Light Communication System: Device Constraints and Design Considerations

Visible light communications (VLC) has the potential to play a major part in future smart home and next generation communication networks. There is significant ongoing work to increase the achievable data rates using VLC, to standardize it and integrate it within existing network infrastructures. The future of VLC systems depends on the ability to fabricate low cost transceiver components and to realize the promise of high data rates. This paper reports the design and fabrication of integrated transmitter and receiver components. The transmitter uses a two dimensional individually addressable array of micro light emitting diodes (μLEDs) and the receiver uses an integrated photodiode array fabricated in a CMOS technology. A preliminary result of a MIMO system implementation operating at a data rate of 1 Gbps is demonstrated. This paper also highlights the challenges in achieving highly parallel data communication along with the possible bottlenecks in integrated approaches.
Dehydration reduces cardiac output and increases systemic and cutaneous vascular resistance during exercise.

This investigation determined the manner in which the cardiovascular system copes with the dehydration-induced reductions in cardiac output (Q) during prolonged exercise in the heat. On two separate occasions, seven endurance-trained subjects (maximal O2 consumption 4.70 +/- 0.41 l/min) cycled in the heat (35 degrees C) for 2 h, beginning at 62 +/- 2% maximal O2 consumption. During exercise, they randomly received either 0.2 liter of fluid and became dehydrated by 4.9 +/- 0.2% of their body weight [i.e., dehydration trial (DE)] or 3.6 +/- 0.4 liter of fluid and replaced 95% of fluid losses [i.e., euhydration trial (EU)]. During the 10- to 120-min period of EU, Q, mean arterial pressure (MAP), systemic vascular resistance (SVR), cutaneous vascular resistance (CVR), and plasma catecholamines did not change while esophageal temperature stabilized at 38.0 +/- 0.1 degrees C. Conversely, after 120 min of DE, Q and MAP were reduced 18 +/- 3 and 5 +/- 2%, respectively, compared with EU (P < 0.05). This was associated with a significantly higher SVR (17 +/- 6%) and plasma norepinephrine concentration (50 +/- 19%, P < 0.05). In addition, CVR was also significantly higher (126 +/- 16 vs. 102 +/- 6% of 20-min value; P < 0.05) during DE despite a 1.2 +/- 0.1 degrees C greater esophageal temperature (P < 0.05). In conclusion, significant reductions in Q are accompanied by significant increases in SVR and plasma norepinephrine and a slight although significant decline in MAP. The cutaneous circulation participates in this systemic vasoconstriction as indicated by increases in CVR despite significant hyperthermia.
Packing Techniques for Virtex-5 FPGAs

Packing is a key step in the FPGA tool flow that straddles the boundaries between synthesis, technology mapping and placement. Packing strongly influences circuit speed, density, and power, and in this article, we consider packing in the commercial FPGA context and examine the area and performance trade-offs associated with packing in a state-of-the-art FPGA---the Xilinx® VirtexTM-5 FPGA. In addition to look-up-table (LUT)-based logic blocks, modern FPGAs also contain large IP blocks. We discuss packing techniques for both types of blocks. Virtex-5 logic blocks contain dual-output 6-input LUTs. Such LUTs can implement any single logic function of up to 6 inputs, or any two logic functions requiring no more than 5 distinct inputs. The second LUT output has reduced speed, and therefore, must be used judiciously. We present techniques for dual-output LUT packing that lead to improved area-efficiency, with minimal performance degradation. We then describe packing techniques for large IP blocks, namely, block RAMs and DSPs. We pack circuits into the large blocks in a way that leverages the unique block RAM and DSP layout/architecture in Virtex-5, achieving significantly improved design performance.
A large scale of CuS nano-networks: Catalyst-free morphologically controllable growth and their application as efficient photocatalysts

Morphologically controllable copper sulfide (CuS) nanoneedle, nanowall, and nanosheet networks on copper substrates have been fabricated by a simple, facile, and fast method based on low-temperature chemical vapor deposition through simply adjusting the reaction conditions such as the temperature and flow rate of argon gas. The compositional and structural analyses indicated that all the obtained nano-networks were single-crystalline. And their growths were possibly controlled by a solid–liquid–solid mechanism. The photocatalytic activities of the different shaped CuS nanostructures have been evaluated by their photodegradation on rhodamine B and methylene blue in aqueous phase, which revealed that in both cases the CuS nanoneedles nano-network exhibited better performance than the other two nanostructures.
Gastroesophageal and extraesophageal reflux symptoms: Similarities and differences

The association between extraesophageal reflux (EER) and symptoms of gastroesophageal reflux disease (GERD) is inadequately understood. We used the Comprehensive Reflux Symptom Scale (CReSS) to evaluate EER and reflux‐symptom prevalence in gastroenterology and otolaryngology outpatients and symptom awareness among UK gastroenterologists.
Personalized Query Suggestion With Diversity Awareness

Query suggestion is an important functionality provided by the search engine to facilitate information seeking of the users. Existing query suggestion methods usually focus on recommending queries that are the most relevant to the input query. However, such relevance-oriented strategy cannot effectively handle query uncertainty, a common scenario that the input query can be interpreted as multiple different meanings. To alleviate this problem, the concepts of diversification and person-alization have been individually introduced to query suggestion systems. These two concepts are often seen as incompatible alternatives, because diversification considers multiple aspects of the input query to maximize the probability that some query aspect is relevant to the user while personalization aims to adapt the suggestions to a specific aspect that aligns with the preference of a specific user. In this paper, we refute this antagonistic view and propose a new query suggestion paradigm, Personalized Query Suggestion With Diversity Awareness (PQS-DA) to effectively combine diversification and personalization into one unified framework. In PQS-DA, the suggested queries are effectively diversified to cover different potential facets of the input query while the ranking of suggested queries are personalized to ensure that the top ones are those that align with a user's personal preference. We evaluate PQS-DA on a real-life search engine query log against several state-of-the-art methods with respect to a variety of metrics. The experimental results verify our hypothesis that diversification and personalization can be effectively integrated and they are able to enhance each other within the PQS-DA framework, which significantly outperforms several strong baselines with respect to a series of metrics.
A single mRNA, transcribed from an alternative, erythroid-specific, promoter, codes for two non-myristylated forms of NADH-cytochrome b5 reductase

Two forms of NADH-cytochrome b5 reductase are produced from one gene: a myristylated membrane-bound enzyme, expressed in all tissues, and a soluble, erythrocyte-specific, isoform. The two forms are identical in a large cytoplasmic domain (Mr approximately 30,000) and differ at the NH2-terminus, which, in the membrane form, is responsible for binding to the bilayer, and which contains the myristylation consensus sequence and an additional 14 uncharged amino acids. To investigate how the two differently targeted forms of the reductase are produced, we cloned a reductase transcript from reticulocytes, and studied its relationship to the previously cloned liver cDNA. The reticulocyte transcript differs from the liver transcript in the 5' non-coding portion and at the beginning of the coding portion, where the seven codons specifying the myristoylation consensus are replaced by a reticulocyte-specific sequence which codes for 13 non-charged amino acids. Analysis of genomic reductase clones indicated that the ubiquitous transcript is generated from an upstream "housekeeping" type promoter, while the reticulocyte transcript originates from a downstream, erythroid- specific, promoter. In vitro translation of the reticulocyte-specific mRNA generated two products: a minor one originating from the first AUG, and a major one starting from a downstream AUG, as indicated by mutational analysis. Both the AUGs used as initiation codons were in an unfavorable sequence context. The major, lower relative molecular mass product behaved as a soluble protein, while the NH2-terminally extended minor product interacted with microsomes in vitro. The generation of soluble reductase from a downstream AUG was confirmed in vivo, in Xenopus oocytes. Thus, differently localized products, with respect both to tissues and to subcellular compartments, are generated from the same gene by a combination of transcriptional and translational mechanisms.
Extrapineal melatonin: analysis of its subcellular distribution and daily fluctuations

Abstract: We studied the subcellular levels of melatonin in cerebral cortex and liver of rats under several conditions. The results show that melatonin levels in the cell membrane, cytosol, nucleus, and mitochondrion vary over a 24‐hr cycle, although these variations do not exhibit circadian rhythms. The cell membrane has the highest concentration of melatonin followed by mitochondria, nucleus, and cytosol. Pinealectomy significantly increased the content of melatonin in all subcellular compartments, whereas luzindole treatment had little effect on melatonin levels. Administration of 10 mg/kg bw melatonin to sham‐pinealectomized, pinealectomized, or continuous light‐exposed rats increased the content of melatonin in all subcellular compartments. Melatonin in doses ranging from 40 to 200 mg/kg bw increased in a dose‐dependent manner the accumulation of melatonin on cell membrane and cytosol, although the accumulations were 10 times greater in the former than in the latter. Melatonin levels in the nucleus and mitochondria reached saturation with a dose of 40 mg/kg bw; higher doses of injected melatonin did not further cause additional accumulation of melatonin in these organelles. The results suggest some control of extrapineal accumulation or extrapineal production of melatonin and support the existence of regulatory mechanisms in cellular organelles, which prevent the intracellular equilibration of the indolamine. Seemingly, different concentrations of melatonin can be maintained in different subcellular compartments. The data also seem to support a requirement of high doses of melatonin to obtain therapeutic effects. Together, these results add information that assists in explaining the physiology and pharmacology of melatonin.
Squeeze-strengthening of magnetorheological fluids (part 2): Simultaneous squeeze–shear at high speeds

The first part of this study demonstrated that magnetorheological fluid undergoes squeeze-strengthening in pure squeeze conditions that promote filtration. This behavior, however, is greatly reduced when shear deformation is superimposed onto the squeezing motion. In order to understand this phenomenon and achieve high yield stresses at high rotational velocities, the second part of this study conducts a thorough experimental characterization of magnetorheological fluid behavior under combined squeeze–shear. After demonstrating that a von Mises yield criterion is applicable to magnetorheological fluid, this criterion is included in the Péclet number, derived in the first part of this study, and used to predict filtration in magnetorheological fluid submitted to simultaneous squeeze–shear. Results show squeeze-strengthening is well predicted in squeeze-dominant flows but gradually delayed in shear-dominant flows. In such conditions, a better prediction is provided by a modified Péclet number, which also takes into account the evolution of the magnetorheological fluid microstructure through the squeeze-to-shear-rate ratio. This ratio is also found to dictate the linear relation between shear stress and compressive force when squeeze-strengthening is observed. Based on the provided understanding, high yield stresses (>1000 kPa) are obtained at high rotational velocities (200 r/min) by maximizing the filtration phenomenon in order to achieve squeeze-strengthening at high compression velocities (5 mm/s).
Diverse in- and output polarities and high complexity of local synaptic and non-synaptic signaling within a chemically defined class of peptidergic Drosophila neurons

Peptidergic neurons are not easily integrated into current connectomics concepts, since their peptide messages can be distributed via non-synaptic paracrine signaling or volume transmission. Moreover, the polarity of peptidergic interneurons in terms of in- and out-put sites can be hard to predict and is very little explored. We describe in detail the morphology and the subcellular distribution of fluorescent vesicle/dendrite markers in CCAP neurons (NCCAP), a well defined set of peptidergic neurons in the Drosophila larva. NCCAP can be divided into five morphologically distinct subsets. In contrast to other subsets, serial homologous interneurons in the ventral ganglion show a mixed localization of in- and output markers along ventral neurites that defy a classification as dendritic or axonal compartments. Ultrastructurally, these neurites contain both pre- and postsynaptic sites preferably at varicosities. A significant portion of the synaptic events are due to reciprocal synapses. Peptides are mostly non-synaptically or parasynaptically released, and dense-core vesicles and synaptic vesicle pools are typically well separated. The responsiveness of the NCCAP to ecdysis-triggering hormone may be at least partly dependent on a tonic synaptic inhibition, and is independent of ecdysteroids. Our results reveal a remarkable variety and complexity of local synaptic circuitry within a chemically defined set of peptidergic neurons. Synaptic transmitter signaling as well as peptidergic paracrine signaling and volume transmission from varicosities can be main signaling modes of peptidergic interneurons depending on the subcellular region. The possibility of region-specific variable signaling modes should be taken into account in connectomic studies that aim to dissect the circuitry underlying insect behavior and physiology, in which peptidergic neurons act as important regulators.
Assessing and Attributing the Benefits from Varietal Improvement Research: Evidence from Embrapa, Brazil

In general, reported rates of return to agricultural RD 6.1 percent of the corresponding value of crop output. If all of those benefits were attributed to Embrapa, a public research corporation accounting for more than half Brazil? s agricultural R&D spending, the benefit-cost ratio would be 78:1. If a geometric attribution rule based on genetic histories is used in conjunction with quantitative evidence on the extent of research collaborations to account for the innovative effort of others, the ratio drops substantially to 16:1. The sources of these gains vary markedly among crops and over time, making it hard to generalize about the international and institutional origins of varietal innovations in Brazilian agriculture during the past several decades.
Sonographic measurement of lateral parapharyngeal wall thickness in patients with obstructive sleep apnea.

INTRODUCTION Lateral parapharyngeal wall (LPW) thickness may be a predominant anatomic factor causing airway narrowing in apneic subjects. In this study, we explored sonographic measurement of the LPW thickness and compared the results with LPW thickness measured by magnetic resonance imaging (MRI). We also investigated the association between sonographic measurement of LPW thickness and apnea-hypopnea index (AHI). METHOD Seventy-six patients with suspected obstructive sleep apnea (OSA) underwent ultrasound examination of LPW thickness after overnight polysomnography. Fifteen out of 76 subjects also participated in correlation and reliability studies of sonographic and MRI measurements of LPW thickness. RESULTS There was good correlation between measurements of LPW thickness on ultrasound and MRI (r = 0.78, P = 0.001), although Bland-Altman analysis indicated overestimation of LPW thickness by ultrasound, when compared with the LPW as measured by MRI. The sonographic measurement of LPW thickness had high reproducibility, with intraclass correlation coefficients of 0.90 and 0.97 for intraoperator and interoperator reliability, respectively. Fifty-eight subjects with significant OSA (AHI > or = 10/h) had a higher body mass index, larger neck circumference, and greater LPW thickness measured by ultrasound than those (n = 18) with an AHI of less than 10 per hour. LPW thickness had a positive correlation with AHI on univariate analysis (r = 0.37, P = 0.001). On multivariate analysis, LPW thickness had a positive independent association with AHI after adjustment for age, sex, neck circumference, and body mass index. The positive association of LPW thickness with AHI remained significant in both univariate and multivariate analyses of men only (n = 62). CONCLUSIONS Sonographic measurement of LPW thickness is a novel and reliable technique and had good correlations with measurement by MRI and the severity of OSA. Ultrasound may provide an alternative imaging modality with easy accessibility and lower cost in OSA research.
Drug therapy for chronic asthma in children

Asthma is a common chronic illness in children and a successful symptom control improves quality of life. Guidelines for the use of drugs in its management are widely available, but for children are often based on consensus opinion and extrapolation of data from studies in adolescents and adults. The aim of this review is to describe the clinical pharmacology of the drugs commonly used to manage chronic asthma in children and identify areas where further study might be useful to determine their best use.
HMM-based modelling of individual syllables for bird species recognition from audio field recordings

This paper presents an automatic system for recognition of bird species from audio field recordings. The acoustic signal is first segmented into isolated time-frequency segments, each corresponding to an individual detected sinusoidal component. Each segment is represented by a temporal sequence of the frequency values of the detected sinusoid, referred to as frequency track. Hidden Markov models (HMMs) are employed to model the temporal evolution of frequency track features. Individual syllables of bird vocalisations are discovered using an unsupervised method based on dynamic time warping and agglomerative hierarchical clustering. The outcome of this is then employed to create individual HMMs for syllables of each species. Experiments are performed on over 33 hours of field recordings, containing 30 bird species. Evaluations demonstrate that the use of individual syllable HMMs provides over 40% error rate reduction over the use of single HMM for each bird species of the same complexity. The syllable HMM-based system recognises bird species with accuracy over 95% using 3 seconds of detected signal.