Miracle-dz/UniFAR-FTUs huggingface dataset:
ANT2 expression under hypoxic conditions produces opposite cell‐cycle behavior in 143B and HepG2 cancer cells

Under hypoxic conditions, mitochondrial ATP production ceases, leaving cells entirely dependent on their glycolytic metabolism. The cytoplasmic and intramitochondrial ATP/ADP ratios, partly controlled by the adenine nucleotide translocator (ANT), are drastically modified. In dividing and growing cells that have a predominantly glycolytic metabolism, the ANT isoform 2, which has kinetic properties allowing ATP import into mitochondria, is over‐expressed in comparison to control cells. We studied the cellular metabolic and proliferative response to hypoxia in two transformed human cell lines with different metabolic backgrounds: HepG2 and 143B, and in their ρ° derivatives, i.e., cells with no mitochondrial DNA. Transformed 143B and ρ° cells continued their proliferation whereas HepG2 cells, with a more differentiated phenotype, arrested their cell‐cycle at the G1/S checkpoint. Hypoxia induced an increase in glycolytic activity, correlated to an induction of VEGF and hexokinase II (HK II) expression. Thus, according to their tumorigenicity, transformed cells may adopt one of two distinct behaviors to support hypoxic stress, i.e., proliferation or quiescence. Our study links the constitutive glycolytic activity and ANT2 expression levels of transformed cells with the loss of cell‐cycle control after oxygen deprivation. ATP import by ANT2 allows cells to maintain their mitochondrial integrity while acquiring insensitivity to any alterations in the proteins involved in oxidative phosphorylation. This loss of cell dependence on oxidative metabolism is an important factor in the development of tumors. © 2004 Wiley‐Liss, Inc.
Feeding Behavior Comparison of Soybean Aphid (Hemiptera: Aphididae) Biotypes on Different Soybean Genotypes

ABSTRACT Soybean aphids have become a serious pest of soybean, Glycine max L. (Merrill), since they were first detected in North America in 2000. Three soybean aphid biotypes have been documented in the United States in the last 10 yr, but few studies have been done on their feeding behavior in the United States The Electrical Penetration Graph is a convenient and successful tool to study the feeding behavior of piercing and sucking insects. This is the first attempt to study the feeding behavior differences between biotype 1 and biotype 2 on soybean genotypes using the Electrical Penetration Graph technique, and includes both resistant and susceptible soybean genotypes from Kansas and Michigan. The experiments were run for 9 h each for each genotype with a total of eight channels at a time. Results indicated that aphids feeding on susceptible genotypes had a significantly greater duration of sieve element phase than when feeding on resistant genotypes. Furthermore, the time taken to reach the first sieve element phase in resistant genotypes was significantly greater than in susceptible genotypes. Most of the aphids reached sieve element phase (>90%) in susceptible genotypes, but only a few (<30%) reached sieve element phase in resistant genotypes during the 9-h recording period; however, we found no differences in any other probing phases between resistant and susceptible genotypes except the number of potential drops in biotype 2. Thus, the resistance was largely associated with phloem tissues. Therefore, some biochemical, physical, or morphological factors could affect stylet penetration of aphids.
Solution Structure of a Kunitz-type Chymotrypsin Inhibitor Isolated from the Elapid Snake Bungarus fasciatus *

Bungarus fasciatusfraction IX (BF9), a chymotrypsin inhibitor, consists of 65 amino acid residues with three disulfide bridges. It was isolated from the snake venom of B. fasciatus by ion-exchange chromatography and belongs to the bovine pancreatic trypsin inhibitor (BPTI)-like superfamily. It showed a dissociation constant of 5.8 × 10−8 m with α-chymotrypsin as measured by a BIAcore binding assay system. The isothermal titration calorimetry revealed a 1:1 binding stoichiometry between this inhibitor and chymotrypsin and apparently no binding with trypsin. We further used CD and NMR to determine the solution structure of this venom-derived chymotrypsin inhibitor. The three-dimensional NMR solution structures of BF9 were determined on the basis of 582 restraints by simulated annealing and energy minimization calculations. The final set of 10 NMR structures was well defined, with average root mean square deviations of 0.47 Å for the backbone atoms in the secondary structure regions and 0.86 Å for residues The side chains of Phe23, Tyr24, Tyr25, Phe35, and Phe47 exhibited many long-range nuclear Overhauser effects and were the principal components of the hydrophobic core in BF9. To gain insight into the structure-function relationships among proteins in the BPTI-like superfamily, we compared the three-dimensional structure of BF9 with three BPTI-like proteins that possess distinct biological functions. These proteins possessed similar secondary structure elements, but the loop regions and β-turn were different from one another. Based on residues at the functional site of each protein, we suggest that the flexibility, rigidity, and variations of the amino acid residues in both the loop and β-turn regions are related to their biological functions.
Right Ventricular Function Is Associated with Left Ventricular Stroke Volume in Patients with Severe Aortic Stenosis and Preserved Ejection Fraction

A subset of patients with severe aortic stenosis (AS) have lower stroke volumes and valve gradients despite a normal left ventricular ejection fraction (LVEF), referred to as paradoxical low‐flow AS (PLF AS). However, the role of right ventricular (RV) function in patients with severe AS and preserved LVEF is not known. We hypothesized that right ventricular function is associated with left ventricular stroke volume in patients with severe AS and preserved LVEF.
A defect of the vacuolar putative lipase Atg15 accelerates degradation of lipid droplets through lipolysis

Lipid droplets (LDs) are the conserved organelles for the deposit of neutral lipids, and function as reservoirs of membrane and energy sources. To date, functional links between autophagy and LD dynamics have not been fully elucidated. Here, we report that a vacuolar putative lipase, Atg15, required for degradation of autophagic bodies, is crucial for the maintenance of LD amount in the yeast Saccharomyces cerevisiae in the stationary phase. Mutant analyses revealed that the putative lipase motif and vacuolar localization of Atg15 are important for the maintenance of LD amount. Loss of autophagosome formation by simultaneous deletion of core ATG genes cancelled the reduction in the LD amount in ATG15-deleted cells, indicating that degradation of autophagic bodies accounts for the functional involvement of Atg15 in LD dynamics. The reduced level of LDs in the mutant strain was dependent on Tgl3 and Tgl4, major lipases for lipolysis in S. cerevisiae. An altered phosphorylation status of Tgl3, higher accumulation of Tgl4, and closer associations of Tgl3 and Tgl4 with LDs were detected in the ATG15-deleted cells. Furthermore, increased levels of downstream metabolites of lipolysis in the mutant strain strongly suggested enhanced lipolytic activity caused by loss of ATG15. Our data provide evidence for a novel link between autophagic flux and LD dynamics integrated with Atg15 activity.
Viral Dynamics during Primary Simian Immunodeficiency Virus Infection: Effect of Time-Dependent Virus Infectivity

ABSTRACT A recent experiment involving simian immunodeficiency virus (SIV) infection of macaques revealed that the infectivity of this virus decreased over the first few months of infection. Based on this observation, we introduce a viral dynamic model in which viral infectivity varies over time. The model is fit to viral load data from eight (donor) monkeys infected by intravaginal inoculation of SIVmac251, three monkeys infected by intravenous inoculation of virus isolated from the donors during the ramp-up phase of acute infection, and three monkeys infected by intravenous inoculation of virus isolated at the viral set-point. Although we only analyze data from 14 monkeys, the new model with time-dependent infectivity seems to fit the data significantly better than a widely used model with constant infectivity (P = 2.44 × 10−11). Our results indicate that plasma virus infectivity on average decays ∼8-fold (95% confidence interval [CI] = 5.1 to 10.3) over the course of acute infection, with the decay occurring exponentially with an average rate of 0.28 day−1 (95% CI = 0.14 to 0.42 day−1). The decay rate in set point plasma virus recipient animals is ∼16 times slower than in ramp-up plasma virus recipient animals and ∼6 times slower than in donor animals. Throughout acute infection up to the set-point, the infection rate is higher in ramp-up plasma virus recipient animals than in set-point plasma virus recipient animals. These results show that the infectivity depends upon the source of viral infection.
Gesture based wireless shadow robot

In this project, an application of gesture mimic human-robot interaction is presented which has been developed using a Kinect sensor. The gesture recognition method combines depth information and traditional joints tracking algorithm using kinect to employ skeleton angular motion in dynamic gesture mimicking. A Master/Slave structured robot control application for master Bluetooth in PC and paired with slave module for the Arduino receiver is developed. The wireless setup provides a favorable function for gesture commands that uses Kinect sensor for controlling of shadow robot. Training session has been utilized for storing the serial string array sets in a Local database of the application which can later be transmitted to the slave at the time it is commanded. A Non-feedback static walking sequence is also been developed for bipedal forward walking of the humanoid robot. Experiment results validate the feasibility and usefulness of the application system.
Pheromones trigger filamentous growth in Ustilago maydis.

Cell recognition and mating in the smut fungus Ustilago maydis have been proposed to involve specific pheromones and pheromone receptors. The respective structural genes are located in the a mating type locus that exists in the alleles a1 and a2. We demonstrate that binding of pheromone to the receptor can induce a morphological switch from yeast‐like to filamentous growth in certain strains. Using this as biological assay we were able to purify both the a1 and a2 pheromone. The structure of the secreted pheromones was determined to be 13 amino acids for a1 and nine amino acids for a2. Both pheromones are post‐translationally modified by farnesylation and carboxyl methyl esterification of the C‐terminal cysteine. An unmodified a1 peptide exhibits dramatically reduced activity. The pheromone alone is able to induce characteristic conjugation tubes in cells of opposite mating type and confers mating competence; even cells of the same mating type undergo fusion. We discuss the role of pheromones in initiating filamentous growth and pathogenic development.
Effect of regB on expression from the P1 and P2 promoters of the Pseudomonas aeruginosa regAB operon

Exotoxin A production in Pseudomonas aeruginosa is dependent on two regulatory genes, regA and regB, which are located in tandem on the chromosome. Expression of regA and regB is controlled by two promoters (P1 and P2) situated upstream of the regAB locus. We have studied the effect of the regA and regB gene products on transcription from the regAB promoters. Transcriptional and translational fusions, under the control of the P. aeruginosa regA promoters, were used to analyze the regulation of these promoters in a variety of genetic backgrounds. When the regA P1 promoter was supplied in trans to strains lacking expression of regB (PAO1) or lacking transcription of the regAB operon (PA103-29), little activity from the P1 promoter was detected. In contrast, activity from the P2 promoter was not affected in either PAO1 or PA103-29. Sequence analysis of the regAB operon of PA103-29 detected two mutations. One of the mutations is predicted to result in a premature stop codon in the regA open reading frame. We complemented PA103-29 with a construction containing regA and an inactive regB or a construction containing both regA and regB to directly analyze the effect of regB on transcription of the regAB operon. When PA103-29 was complemented with regA but not regB, we could not detect any transcription from the P1 promoter. Complementation of PA103-29 with both regA and regB resulted in a high level of transcription from the P1 promoter and a corresponding early transcriptional activation of toxA. Our results indicated that induction of transcription from the P1 promoter requires the regB open reading frame and thus the regAB operon is autogenously regulated in P. aeruginosa.
Nucleotide sequence and transcriptional regulation of the yeast recombinational repair gene RAD51

The RAD51 gene of Saccharomyces cerevisiae is required both for recombination and for the repair of DNA damage caused by X rays. Here we report the sequence and transcriptional regulation of this gene. The RAD51 protein shares significant homology (approximately 50%) over a 70-amino-acid with the RAD57 protein (J.A. Kans and R.K. Mortimer, Gene 105:139-140, 1991), the product of another yeast recombinational repair gene, and also moderate (approximately 27%), but potentially significant, homology with the bacterial RecA protein. The homologies cover a region that encodes a putative nucleotide binding site of the RAD51 protein. Sequences upstream of the coding region for RAD51 protein share homology with the damage response sequence element of RAD54, an upstream activating sequence required for damage regulation of the RAD54 transcript, and also contain two sites for restriction enzyme MluI; the presence of MluI restriction sites has been associated with cell cycle regulation. A 1.6-kb transcript corresponding to RAD51 was observed, and levels of this transcript increased rapidly after exposure to relatively low doses of X-rays. Additionally, RAD51 transcript levels were found to that of a group of genes involved primarily in DNA synthesis and replication which are thought to be coordinately cell cycle regulated. Cells arrested in early G1 were still capable of increasing levels of RAD51 transcript after irradiation, indicating that increased RAD51 transcript levels after X-ray exposure are not solely due to an X-ray-induced cessation of the cell cycle at a period when the level of RAD51 expression is normally high.
Automatic sentiment analysis of Twitter messages

Twitter® is a microblogging service usually used as an instant communication platform. The capacity to provide information in real time has stimulated many companies to use this service to understand their consumers. In this direction, TV stations have adopted Twitter for shortening the distance between them and their viewers, and use such information as a feedback mechanism for their shows. The sentiment analysis task can be used as one such feedback mechanism. This task corresponds to classifying a text according to the sentiment that the writer intended to transmit. A classifier usually requires a pre-classifled data sample to determine the class of new data. Typically, the sample is pre-classified manually, making the process time consuming and reducing its real time applicability for big data. This paper proposes an automatic sentiment classifier for Twitter messages, and uses TV shows from Brazilian stations for benchmarking. The automatic sentiment analysis reduces human intervention and, thus, the complexity and cost of the whole process. To assess the performance of the proposed system tweets related to a Brazilian TV show were captured in a 24h interval and fed into the system. The proposed technique achieved an average accuracy of 90%.
Cardiovascular actions of substituted adenosine analogues

1 The effects of adenosine on systemic blood pressure, coronary blood flow and cardiac contractility and rate were studied in anaesthetized open‐thorax dogs. 2 The potency and duration of action of substituted adenosine analogues were compared with that of adenosine. 3 With the exception of 2‐chloroadenosine, in which coronary dilator activity was enhanced, substitution in the 2‐position of the adenosine molecule reduced activity. 4 In all cases 2‐substitution prolonged the duration of the coronary dilator activity of adenosine. 5 N6‐Methylation of adenosine and 2‐chloroadenosine reduced their coronary dilator activities, but had no effect on the duration of the response. 6 Comparison of the coronary dilator potencies and hypotensive activities of 2‐ethylaminoadenosine and 2‐methoxyadenosine indicates that these analogues have some specificity for the coronary bed.
Ca2+-dependent Structural Changes in the B-cell Receptor CD23 Increase Its Affinity for Human Immunoglobulin E*

Background: Immunoglobulin E (IgE) plays a central role in allergic disease. The B-cell receptor CD23 is pivotal in regulating IgE synthesis. Results: Ca2+-dependent structural changes in CD23 enable additional interactions with IgE. Conclusion: Mechanism for Ca2+-induced increase in affinity is revealed. Significance: Ca2+ binding brings an extra degree of modulation to CD23 function. Immunoglobulin E (IgE) antibodies play a fundamental role in allergic disease and are a target for therapeutic intervention. IgE functions principally through two receptors, FcϵRI and CD23 (FcϵRII). Minute amounts of allergen trigger mast cell or basophil degranulation by cross-linking IgE-bound FcϵRI, leading to an inflammatory response. The interaction between IgE and CD23 on B-cells regulates IgE synthesis. CD23 is unique among Ig receptors in that it belongs to the C-type (calcium-dependent) lectin-like superfamily. Although the interaction of CD23 with IgE is carbohydrate-independent, calcium has been reported to increase the affinity for IgE, but the structural basis for this activity has previously been unknown. We have determined the crystal structures of the human lectin-like head domain of CD23 in its Ca2+-free and Ca2+-bound forms, as well as the crystal structure of the Ca2+-bound head domain of CD23 in complex with a subfragment of IgE-Fc consisting of the dimer of Cϵ3 and Cϵ4 domains (Fcϵ3-4). Together with site-directed mutagenesis, the crystal structures of four Ca2+ ligand mutants, isothermal titration calorimetry, surface plasmon resonance, and stopped-flow analysis, we demonstrate that Ca2+ binds at the principal and evolutionarily conserved binding site in CD23. Ca2+ binding drives Pro-250, at the base of an IgE-binding loop (loop 4), from the trans to the cis configuration with a concomitant conformational change and ordering of residues in the loop. These Ca2+-induced structural changes in CD23 lead to additional interactions with IgE, a more entropically favorable interaction, and a 30-fold increase in affinity of a single head domain of CD23 for IgE. Taken together, these results suggest that binding of Ca2+ brings an extra degree of modulation to CD23 function.
WAVE2 Regulates High-Affinity Integrin Binding by Recruiting Vinculin and Talin to the Immunological Synapse

ABSTRACT T-cell-receptor (TCR)-mediated integrin activation is required for T-cell-antigen-presenting cell conjugation and adhesion to extracellular matrix components. While it has been demonstrated that the actin cytoskeleton and its regulators play an essential role in this process, no mechanism has been established which directly links TCR-induced actin polymerization to the activation of integrins. Here, we demonstrate that TCR stimulation results in WAVE2-ARP2/3-dependent F-actin nucleation and the formation of a complex containing WAVE2, ARP2/3, vinculin, and talin. The verprolin-connecting-acidic (VCA) domain of WAVE2 mediates the formation of the ARP2/3-vinculin-talin signaling complex and talin recruitment to the immunological synapse (IS). Interestingly, although vinculin is not required for F-actin or integrin accumulation at the IS, it is required for the recruitment of talin. In addition, RNA interference of either WAVE2 or vinculin inhibits activation-dependent induction of high-affinity integrin binding to VCAM-1. Overall, these findings demonstrate a mechanism in which signals from the TCR produce WAVE2-ARP2/3-mediated de novo actin polymerization, leading to integrin clustering and high-affinity binding through the recruitment of vinculin and talin.
Secondary Frequency Control With On–Off Load Side Participation in Power Networks

We study the problem of decentralized secondary frequency regulation in power networks where ancillary services are provided via on–off load-side participation. We initially consider on–off loads that switch when prescribed frequency thresholds are exceeded, together with a large class of passive continuous dynamics for generation and demand. The considered on–off loads are able to assist existing secondary frequency control mechanisms and return to their nominal operation when the power system is restored to its normal operation, a highly desirable feature that minimizes users’ disruption. We show that system stability is not compromised despite the switching nature of the loads. However, such control policies are prone to chattering, which limits the practicality of these schemes. As a remedy to this problem, we propose a hysteretic on–off policy where loads switch on and off at different frequency thresholds and show that stability guarantees are retained when the same decentralized passivity conditions for continuous generation and demand hold. Several relevant examples are discussed to demonstrate the applicability of the proposed results. Furthermore, we verify our analytic results by using numerical investigations on the Northeast Power Coordinating Council (NPCC) 140-bus system.
Latent Kullback-Leibler control for dynamic imitation learning of whole-body behaviors in humanoid robots

We study dynamic imitation learning for achieving whole-body behaviors of a humanoid robot, which are similar to the demonstrations, while keeping the dynamic balance. Most of successful methods are based on complex numerical optimization or reinforcement learning; hence, they require long time computation or a significant number of trials. In this paper, we alleviate this issue by proposing a new model-free imitation learning framework based on Kullback-Leibler control, which allows us to quickly adapt a demonstration trajectory from a human teacher to a robot. First, a number of the robot's reference trajectories are generated by random explorations and executed by the robot to store the actual state transition data set. Second, only the feasible state transition data (without falling over) are extracted from the data set. These data are used to learn a dynamically-consistent state transition model as an abstract model of feasible robot behaviors. The robot can then quickly imitate a demonstration trajectory when it is newly given while maintaining the dynamic balance by computing only the analytic solution of the KL control with the learned state transition model. We further extend the framework's scalability for high dimensional robots by proposing to embed it into a low-dimensional shared latent space between the human demonstrator and the robot, which can be extracted using the kernel canonical correlation analysis. We conducted several experiments with a small humanoid robot (NAO) model and human motion capture data. Consequently, we achieved the dynamic imitation learning of the whole-body behaviors in less than 0.1 s in our MATLAB implementation.
On hot flash mechanism, measurement, and treatment

H ot flashes are a common problem in many women. Although hormonal treatments, some newer antidepressants, gabapentin, and clonidine have been shown to decrease hot flashes, improved treatment options are needed to provide substantial relief without unwanted risks or side effects. A better understanding of the physiology and measurement of hot flashes would expedite the development and testing of more effective treatment options.