cssi/SciSciGPT-SciSciNet huggingface dataset:
A Linearly Fourth Order Multirate Runge---Kutta Method with Error Control

To integrate large systems of locally coupled ordinary differential equations with disparate timescales, we present a multirate method with error control that is based on the Cash---Karp Runge---Kutta formula. The order of multirate methods often depends on interpolating certain solution components with a polynomial of sufficiently high degree. By using cubic interpolants and analyzing the method applied to a simple test equation, we show that our method is fourth order linearly accurate overall. Furthermore, the size of the region of absolute stability is increased when taking many "micro-steps" within a "macro-step." Finally, we demonstrate our method on three simple test problems to confirm fourth order convergence.
RO15-4513 antagonizes the anxiolytic effects of ethanol in a nonshock conflict task at doses devoid of anxiogenic activity.

RO15-4513 is a partial benzodiazepine inverse agonist that has been reported to antagonize some of the biochemical and neurobehavioral actions of ethanol. However, whether this antagonistic action of RO15-4513 is dependent on the drug exerting its intrinsic (inverse agonist) properties is nuclear at present. The purpose of the present study was to examine whether RO15-4513 was capable of antagonizing the anxiolytic effects of ethanol in a nonshock conflict task at doses that, by themselves, do not reveal the compound's intrinsic anxiogenic properties. The consummatory conflict task employed (negative contrast) involves quantifying how animals respond to an abrupt, unexpected reduction in reward (sucrose solution), and is particularly sensitive to the effects of anxiolytic agents, including ethanol. As previously demonstrated, depressed consummatory behavior engendered by reward reduction was significantly alleviated by ethanol (0.75 g/kg). This anxiolytic effect of ethanol, however, was antagonized dose dependently by RO15-4513 (0.1875–3.0 mg/kg). Only the highest dose of RO15-4513 (3.0 mg/kg) showed evidenced of further response suppression. Lower doses of RO15-4513 tested did not exert an anxiogenic effect when given alone. Thus the antagonism of EtOH's anxiolytic (contrast-reducing) effects occured at doses of RO15-4513 (0.375–1.5 mg/kg) that did not exhibit any intrinsic anxiogenic activity. As such, these results suggest that RO15-4513 interacts with the anxiolytic effects of ethanol in a nonadditive fashion in this test situation.
‘I was bullied too’: stories of bullying and coping in an online community

The American Academy of Pediatrics has identified bullying as a serious health risk for adolescents. In today's age of social media and smartphones, this health risk has taken on new forms and extended its reach. Strategies to reduce the prevalence of and negative consequences associated with both traditional bullying and cyberbullying require knowledge of victims' lived experiences as well as the coping strategies they employ – both effectively and ineffectively – to respond to their tormentors. This article presents findings from an in-depth content analysis of the entire set of 1094 comments from a viral blog post about cyberbullying in which people shared their personal stories of bullying and coping. These stories included a mix of both traditional and online forms of victimization, as well as more general reflections about the distinct qualities of networked publics that serve to magnify, spread, and exacerbate the effects of bullying. The findings suggest that victims of both traditional bullying a...
Descending corticofugal neurons in layer 5 of rabbit S1: evidence for potent corticocortical, but not thalamocortical, input.

Extracellular recordings were obtained from descending corticofugal neurons of layer 5 (CF-5 neurons) in primary somatosensory cortex (S1) of awake rabbits. These cells were identified by antidromic activation via stimulation sites in ventrobasal (VB) thalamus. Recordings were also obtained from putative GABAergic interneurons (suspected inhibitory interneurons, SINs) located in the same microelectrode penetrations, and in close proximity (±300 µm) to the CF-5 neurons. In some experiments, the above populations were recorded simultaneously with neurons in the topographically aligned VB thalamic barreloid. Each of several experimental strategies failed to reveal evidence of monosynaptic thalamic input to CF-5 neurons, but revealed a clear monosynaptic input to neighboring SINs: (1) whereas CF-5 neurons responded at very long synaptic latencies to intense electrical stimulation of VB thalamus, neighboring SINs responded at short latencies; (2) whereas cross-correlations between CF-5 neurons and topographically aligned VB neurons failed to show significant peaks indicative of monosynaptic VB input, neighboring SINs did show such peaks; and (3) whereas CF-5 neurons were unresponsive to microstimulation of topographically aligned VB thalamic barreloids, neighboring SINs were very responsive to such stimulation. Both CF-5 neurons and neighboring SINs responded to electrical stimulation of the corpus callosum with a robust, short-latency synaptic response. This finding demonstrates that CF-5 neurons are capable of vigorous, short-latency responses to excitatory synaptic input. These data suggest considerable specificity in the thalamocortical connectivity of subpopulations within layer 5, and support the notion that CF-5 neurons are dominated by corticocortical rather than thalamocortical input.
UNSTEADY NUMERICAL SIMULATIONS OF SUBSONIC FLOW OVER A PROJECTILE WITH JET INTERACTION

Abstract : This report describes a computational study undertaken to consider the aerodynamic effect of synthetic jets as a means to provide the control authority needed to maneuver a projectile at low subsonic speeds. The time-accurate Navier-Stokes computational technique has been used to obtain numerical solutions for the unsteady jet interaction flow field for a projectile at a subsonic speed, Mach = 0.11, and several angles of attack from O deg to 4 deg. Qualitative flow field features show the interaction of the time dependent jet with the free stream flow. Numerical results show the effect of the jet on the flow field, surface pressures and aerodynamic coefficients. Unsteady numerical results have been obtained for a two-dimensional jet flow and compared with experimental data for validation. The same unsteady jet modeling technique has been applied to a subsonic projectile. These numerical results are being assessed to determine if synthetic jets can be used to provide the control authority needed for maneuvering munitions to hit the targets with precision.
Dual expression of CD80 and CD86 produces a tumor vaccine superior to single expression of either molecule.

A murine model for neuroblastoma, Neuro-2a (N2a), was used to establish a model tumor vaccine. An aggressive subclone of N2a and the less aggressive parental line were transfected with CD80, CD86, or both molecules and stable lines were established. The less aggressive N2a expressing either CD80 or CD86 induced anti-tumor immunity. In contrast, dual expression of CD80 and CD86 was required to initiate a protective anti-tumor immune response against the aggressive subclone. Control of tumor growth was dependent on CD8+ lymphocytes that infiltrated dual-expressing (CD80 and CD86) lesions. These tumor-infiltrating lymphocytes (TIL) exhibited a non-classical mechanism of tumor cell lysis that may require both the up-regulation of cell surface molecules on the tumor and the subsequent lytic activity normally associated with CD8+ TIL. Although Fas was up-regulated by the tumor in the presence of IFN-γ, N2a and transfected N2a cell lines were not sensitive to Fas-mediated lysis.
Improved nerve regeneration through piezoelectric vinylidenefluoride : trifluoroethylene copolymer guidance channels

Piezoelectric materials generating electrical charges in response to mechanical strain may be used to stimulate axonal regeneration following nerve injury. Tubular nerve guidance channels were extruded from a vinylidenefluoride-trifluoroethylene copolymer using a melt-extrusion process. Unlike vinylidenefluoride homopolymer, the copolymer does not need mechanical stretching to achieve a dipole-containing crystal structure, enabling the fabrication of complex piezoelectric devices. Selected tubes were rendered piezoelectric in a high voltage corona poling apparatus. Crystal structure changes induced by poling were evaluated with differential scanning calorimetry. In contrast to unpoled samples, poled ones displayed a sharp endothermic peak and a greater heat of transition at the Curie temperature, indicative of an increase in crystal order and size. The piezoelectric output of poled tubes was characterized using a laser-monitored deflection system interfaced with a charge amplifier and oscilloscope. Poled tubes generated significant voltages in response to slight mechanical deformations. The magnitude of electrical output was independent of the poling polarity. Unpoled tubes showed no electrical output. Positive, negative and unpoled vinylidenefluoride-trifluoroethylene copolymer tubes were used to repair a 10 mm gap in transected sciatic nerves of adult rats. Nerves regenerated in positively poled channels had a significantly greater number of myelinated axons than those regenerated in unpoled channels 4 wk post-implantation. Negatively poled channels contained an intermediate number of myelinated axons. We concluded that piezoelectrically active vinylidenefluoride-trifluoroethylene copolymer tubes significantly enhance nerve regeneration as compared to chemically identical, unpoled tubes and that the polarity of the corona poling procedure used to fabricate piezoelectric materials may play a role in determining biological responses.
Desensitization by Antidepressants of Central Norepinephrine Receptor Systems Coupled to Adenylate Cyclase

The experimental results discussed in this paper provide evidence that antidepressant-induced attenuation of the NE receptor-coupled adenylate cyclase system in brain and the down-regulation of its beta adrenoceptor subpopulation result in a net deamplification of the NE signal. The desensitization of the NE receptor system requires an unhindered occupancy of the receptor by the agonist NE. Following adrenalectomy, the non-beta population of NE receptors coupled to adenylate cyclase shows an enhanced response to NE without changes in the activity of adenylate cyclase or phosphodiesterase. This supersensitivity to NE can be prevented by corticosterone. The synaptic availability of 5HT is co-required for the down-regulation by DMI-like drugs of the density of beta adrenoceptors. Moreover, beta adrenoceptors from tissue deprived of serotonergic neuronal input display a marked decrease in agonist affinity as determined from competition binding of (-)-isoproterenol for [3H]dihydroalprenolol. Using NE as an agonist, competition binding curves with membrane preparations from cortical tissue lacking 5HT input show low affinity binding of the receptor for NE that cannot be further modified by guanine nucleotides. The reduction in beta adrenoceptor agonist affinity following reduction of the synaptic availability of 5HT is accentuated by chronic administration of DMI or zimelidine. The new experimental data on the biomolecular linkage between serotonergic and noradrenergic neurons, expressed functionally at the level of NE receptors, provide the scientific basis for a "serotonin-norepinephrine link hypothesis" of affective disorders. The pursuit of studies on the molecular mechanisms of the action of steroid hormones on central NE receptor systems and on mechanisms underlying the functional 5HT-NE linkage and its modification by antidepressants should generate a deeper understanding of neuronal signal processing in brain.
Thai remote sensing small satellite program

Abstract This paper describes the THAI REMOTE SENSING SMALL SATELLITE (TRSSS) PROGRAM and its overall system concept. Mission requirements, design philosophy, preparation, programme management, human resource development, technology transfer, applications development, users networking and operational scenario for the planned 5 year life span of the satellite are described. The program’s main aim is to provide more effective tools for management of natural resources and environment of the kingdom of Thailand, which is one of the world’s major agricultural produce exporting nations. The program will also be a part of Thailand’s input for international cooperation with special focus for providing services to her neighbouring ASEAN countries. The TRSSS will provide modern facilities for operation in the 21st century and will operate on an operational basis. The imagery data from the program, when enhanced by a more developed telecommunications infrastructure, will develop into one of the main components for Thailand’s National Information Infrastructure (NII). The program has reached the preliminary system definition phase. Preliminary TRSSS satellite and subsystems characteristics have been defined. They include: Preliminary Mission Performance; mission life, orbit characteristics, type, inclination, altitude, coverage repeat and data downlink: Temporal Performance; revisit time, maximum imaging time per orbit: Spatial performance; swath width, ground resolution, RMS image locations: and Spectral Performance; spectral bandwidths. TRSSS’s system architecture consists of 4 main components, namely: Ground Segment; Mission Control Centre (MCC) and Data Acquisition and Processing Facility (DAPF): Space Segment, comprising a spacecraft bus and an instrument; Launch Segment; and Applications Segment.
A doubly curved elliptical crystal spectrometer for the study of localized x-ray absorption in hot plasmas

X-ray absorption spectroscopy is a powerful tool for the diagnosis of plasmas over a wide range of both temperature and density. However, such a measurement is often limited to probing plasmas with temperatures well below that of the x-ray source in order to avoid object plasma emission lines from obscuring important features of the absorption spectrum. This has excluded many plasmas from being investigated by this technique. We have developed an x-ray spectrometer that provides the ability to record absorption spectra from higher temperature plasmas than the usual approach allows without the risk of data contamination by line radiation emitted by the plasma under study. This is accomplished using a doubly curved mica crystal which is bent both elliptically and cylindrically. We present here the foundational work in the design and development of this spectrometer along with initial results obtained with an aluminum x-pinch as the object plasma.
Effects of water loss on primary production: A landscape-scale model

Water loss from stream ecosystems has profound effects on primary producers. The small body of literature on algal responses to desiccation has emphasized mechanisms of resistance to desiccation, recovery of metabolic activity upon rewetting, and small spatial scales. Unfortunately, small-scale patterns are difficult to interpret because of the high degree of variability in both hydrologic patterns of drying and ecological processes within individual drainage basins. Consequently, effects of drying are best examined at larger spatial scales because variation that appears random at smaller scales become incorporated into larger, more predictable patterns across an entire catchment. We present a conceptual model of the effects of water loss on primary producers applicable to the scale of the entire catchment. This perspective describes differences in susceptibility to water loss, and differential rates of decline and recovery in primary production as a function of location within the catchment. Future considerations of drying on ecosystem attributes such as primary production will be facilitated by treating streams as patchy, interconnected landscapes in space and time and recognizing spatially explicit effects of disturbance. It is likely that streams of different regions vary widely in terms of the occurrence of drought, the geophysical template, and response variables (types of organisms present and their collective metabolism). The challenge in drought research today is to determine what phenomena are general and of widespread application and which are peculiar to given regions.
A Behaviorally Oriented Study Skills Program.

A study skills program should have low time requirements, raise the student’s GPA, and create durable behaviors. Twenty-four male sophomore cadets at the USAF Academy were placed in one of two groups by their rank-order place on a list of academically deficient students. The experimental group and the control group both received normal directive counseling. The experimental group received a behaviorally oriented study skills program requiring two hours of supervisory time and minimal behavior recording and showed a mean increase of .54 GPA points; the control group showed an increase of .02 at the end of the semester. The results indicate this program satisfied the basic requirement of study skills training.
Analysis of microstructure of coating suspensions

Abstract Lattice Boltzmann (LB) simulation has been employed to model spherical particle suspensions in a Couette flow that is encountered in a blade coater. The microstructures of particle configurations produced from the simulations are analyzed by using the pair distribution function and the pair analysis technique of Honeycutt and Anderson [J.D. Honeycutt, H.C. Anderson, J. Chem. Phys. 91 (1987) 4950.]. The hypothesis of the co-existence of icosahedral and crystal order in this suspension is proposed and confirmed by the LB simulation. It is evident that a coating suspension under shear force may be characterized by a blend of icosahedral, face-centered cubic (FCC), body-centered cubic (BCC), and hexagonal closed-packed (HCP) clusters. It is observed that relatively ordered clusters may convert to more disordered clusters under shear forces at a high solid concentration. It seems that short-range lubrication forces are responsible for such structural transition.
An examination of the decision-making process used by designers in multiple disciplines

Design-thinking is an inductive and participatory process in which designers are required to manage constraints, generate solutions, and follow project timelines in order to complete project goals. The researchers used this exploration study to look at how designers in various disciplinary fields approach design projects. Designers were asked to describe a project and a decision that they had to make previously. Decisions were analyzed to determine whether they were ready-made versus custom-made solutions. The process by which the designers arrived at the decisions was categorized as idea-imposition or discovery. Results indicated that designers work with multiple constraints while designing, and the majority used a custom-made solution following a discovery process.
Valproic acid‐induced somite teratogenesis in the chick embryo: Relationship with pax‐1 gene expression

The repeated pattern of the axial skeleton results from the segmentation and re-segmentation of the mesodermally derived somites. During these early events of somite development, the vertebrate embryonic axial skeleton is most susceptible to the teratogenic effects of a variety of pharmaceutical and environmental agents. One example is the anticonvulsant drug valproic acid (VPA), which has been shown to cause craniofacial and minor and major skeletal defects in human and animal embryos. We hypothesize that a candidate set of molecular targets of teratogens are the Pax family of pattern-forming genes, specifically Pax-1, which has been previously demonstrated to be an important regulator of axial skeletal patterning at the somite level. In this study, early developmental stage chick embryos were treated with VPA and dose-dependent malformations in somite development were observed. Two classes of anomalies were evident: class I included discrete sites of somitic fusions or mis-segmentation, and Class II included large areas of disorganized somite patterning. Northern blot analysis revealed a decreased level of Pax-1 expression in VPA-treated embryos. Whole mount in situ hybridization analysis showed that somite anomalies correlate spatially with regions of decreased Pax-1 expression. Finally, comparison of the VPA-induced somitic anomalies with those caused by gene-specific perturbation of Pax-1 gene expression through the use of an antisense oligonucleotide revealed significant similarities. Taken together, these results support the hypothesis that Pax-1 is a molecular target in VPA axial skeletal teratogenicity. © 1996 Wiley-Liss, Inc.
Simultaneous Application of Live Turkey Herpesvirus and Infectious Bursal Disease Vaccines Against Marek’s Disease and Infectious Bursal Disease

Abstract The efficacy of cell-associated (CA) and cell-free (CF) infectious bursal disease (IBD) vaccines in maternal antibody (MAb)-bearing broiler chickens was compared. Compatibility and potency of a mixed vaccine combining live CA turkey herpesvirus (HVT) and CA IBD vaccine viruses were also tested against gross lesions induced by Marek's disease (MD) or IBD in specific-pathogen- free chickens. Both CA and CF IBD vaccines provided significant protection against gross bursal lesions of IBD in the presence of MAb. Although chickens receiving the CA vaccine showed a slightly higher (60 to 86.7%) protective index (PX) than CF vaccine recipients (40 to 66.7%), there was no statistical difference in their PX between comparable CA and CF IBD vaccines. The HVT and IBD virus (IBDV) were compatible when they were combined as a live bivalent mixed HVT-IBDV vaccine. Based on the incidence of gross lesions induced by challenge exposure to MD or IBD, potency of the mixed vaccine was similar to that of the monovalent HVT or IBD vaccine. Antagonism did not occur between the two component vaccines when they were applied simultaneously.
Improved survival with neoadjuvant therapy and resection for adenocarcinoma of the esophagus.

Objective This study sought to determine the impact of preoperative chemotherapy and radiation therapy (neoadjuvant therapy) followed by resection in patients with adenocarcinoma of the esophagus. Summary Background Data Long-term survival in patients with carcinoma of the esophagus has been poor. An increase in the incidence of adenocarcinoma of the esophagus has been reported recently. Methods Fifty-eight patients with biopsy-proven adenocarcinoma of the esophagus treated at this institution from January 1951 through February 1993 were studied. Since 1989, 24 patients were entered prospectively into a multimodality treatment protocol consisting of preoperative cisplatin, 5-fluorouracil (5-FU), and leucovorin with or without etoposide, and concomitant mediastinal radiation (30 Gy)
Normal Approximation and Large Deviations for the Robbins-Monro Process*

when # is unknown, and the Y,'s are observable. Thus, theorems which assert the convergence or non-convergence of X,, to a root of (1.2) are of interest. In particular, it is known that if (1.2) has a unique solution xo, and if G is suitably well-behaved, then ]/n(X,,-Xo) has an asymptotic normal distribution (see [3] and/or [6]). Here we will supplement this information by investigating the rate of convergence of the distribution function of ]/~(X,-xo) to normality end the probability of large deviations by X . x 0 t h a t is, the probability that Xn-x o is either >e or < ~ where e is a small positive number which does not vary with n. In studying these questions, we may without loss of generality (and will) restrict our attention to the case that x o = 0.
Cellular Potts Modeling of Matrix-Dependent Endothelial Cell Networking

Networking of endothelial cells during fetal and post-natal development relies upon dynamic remodeling and subsequent stabilization of cell-cell and cell-extracellular matrix (ECM) interactions. Herein, we investigate lung endothelial cells network dynamics on thin films of engineered ECM. These systems adhere to the Differential Adhesion Hypothesis and their behaviors are well reproduced with a Cellular Potts Model. In order to gain insight on the profound effect external environment has on cell behavior, our model explicitly includes the ECM, as we explore particular changes in networking dynamics with changes in substrate parameters. Further, we describe specifics of the system Hamiltonian governing the Monte Carlo methods with addition of experimentally derived rules that can simulate both normal and non-networking cells systems. The biological significance of derived cell-cell and cell-matrix adhesion and cohesion energies that most appropriately model our experimental data is discussed.
12B-2 Functional Doppler Imaging: A Feasibility Study

We have developed a new method, called 2D flow index mapping (2D-FIM), for quantitative imaging of functional hemodynamic indices, such as resistive index (RI), by retrospective analysis of power Doppler flow waveforms from one complete cardiac cycle. To evaluate this method, a feasibility study was performed in renal transplant patients undergoing routine duplex examination and normal volunteers. Baseband quadrature-demodulated ultrasound echoes were acquired from the parenchyma of the transplant kidneys (n=9) and from normal native kidneys (n=4). The RI values computed from arterial Doppler signals were measured using 2D-FIM. These indices showed a high correlation (Pearson's r=0.8, P<0.0004) with the values measured using spectral Doppler waveforms. Our preliminary results demonstrate the feasibility of 2D-FIM in renal transplant patients. Further refinement of these methods could lead to visualizing the functional hemodynamics in various complex vascular beds as well as for a more complete functional hemodynamic assessment in renal transplant patients.
Irritable bowel syndrome and ischemic colitis: evidence supporting the increased use of alosetron.

Alosetron, a 5-hydroxytryptamine 3 (5-HT3) receptor antagonist, was approved by the US Food and Drug Administration (FDA) for the treatment of diarrhea-predominant irritable bowel syndrome (IBS-D) in women in February 2000. Initial clinical trials demonstrated significant efficacy, particularly in improving fecal urgency, stool frequency and consistency [Camilleri et al. 2001]. In a recent review and systematic meta-analysis of eight alosetron clinical trials, the number needed to treat (NNT) was reported to be 7.5 [Shah et al. 2012]. Although its efficacy was never questioned, safety became a concern as cases of ischemic colitis (IC) were reported, leading to voluntary withdrawal of alosetron by GlaxoSmithKline in November 2000. Alosetron was reintroduced in 2002 as a result of patient advocacy, with a risk management plan (RMP) designed to limit availability to women with severe IBS-D [Chang et al. 2010; Lewis, 2011].
Farm households and nonfarm activities in Ethiopia: does clustering influence entry and exit?

This article examines how clustering affects the entry and exit decisions of farm households into and from nonfarm enterprises in rural Ethiopia. We find that the existence of clusters of microenterprises in the same district increases the likelihood of a rural household to start a nonfarm enterprise. Similarly, clustering of big manufacturing firms in the same zone is found to increase the likelihood of farm households to start a nonfarm enterprise. Nonfarm enterprises operating in clusters are also found to have a lower probability of exit than those operating outside of clusters. The study further investigates the impact of entry and exit into and from nonfarm enterprises on farm household's well-being using as indicators total household income, the food security status of a household, and the household's ability to raise enough money in case of emergency. Using propensity score matching to account for selection bias, we find that entry into nonfarm enterprises significantly increases household's income and food security status. Exit from nonfarm enterprises, on the other hand, is found to significantly reduce household's income.
A Solution for the Temperature Distribution in a Pipe Wall Subjected to Internally Stratified Flow

Stratified flow in a pipe is a phenomenon in which two distinct fluids flow simultaneously through a pipe with little or no mixing. This paper presents a solution for the temperature distribution in a pipe wall subjected to internally stratified flow by solving Laplace's equation in cylindrical coordinates using a finite Fourier cosine transform. A one-dimensional approximation for the temperature distribution in the pipe at the interface is developed to uncouple the top and bottom sections. Results from the solution for a case study of a particular physical situation were compared to the solution obtained using the ANSYS finite element computer program
Anatomical analysis of nodule development in soybean reveals an additional autoregulatory control point

Abstract The region of the root of soybean ( Glycine max [L.] Merr. cv. Bragg) susceptible to nodule initiation by Bradyrhizobium japonicum Jordan USDA110 was examined by serial section and light microscopy to study the control of nodule development. Three successive susceptible regions separated by 24-h intervals were examined. Infection foci were catalogued within defined stages of nodule development (as defined by Calvert et al., Can. J. Bot., 62 (1984) 2375–2384) and their number and location determined after short (72 h) and long (13 days) post-inoculation periods. The overall distributions of cell division stages were similar for both short and long periods, indicating that regulatory mechanisms were active throughout root development. Early cell division foci with no visible meristems (stages I–II) appeared with similar frequency in each susceptible region. In contrast, the frequency of more mature cell division events showing developing meristems (stagesIII–IV) was decreased in the third susceptible region for both periods. The constant frequency of cell division stages I–II within the feedback regulated reduction coupled with the reduction of later stages implies that nodule initiation is slowed and that the transition from cell division stage II to stage III is also regulated.
Thermodynamics of the As(III)−Thiol Interaction: Arsenite and Monomethylarsenite Complexes with Glutathione, Dihydrolipoic Acid, and Other Thiol Ligands

Colorimetric (near-UV absorption spectroscopy) and calorimetric (isothermal titration calorimetry) methods have been used to quantify the equilibrium and thermodynamics of arsenite and monomethylarsenite (MMA) coordinating to glutathione (GSH) and the dithiols dimercaptosuccinic acid (DMSA), dihydrolipoic acid (DHLA), and dithiothreitol (DTT). We found that both arsenite and MMA form moderately stable complexes (β = 106−107) with GSH; that arsenite forms a particularly stable 2:3 complex (β ≈ 1018) with the biological cofactor DHLA; that MMA has a somewhat higher affinity than arsenite for thiol ligands; and that entropic factors modulate the overall stability of As(III) complexes with thiols, which are favored by the exothermic formation of As(III)−thiolate bonds. The implications of these results for arsenic toxicity are discussed.
Fetal development of T cell repertoire diversity and clonal expansion. • 1296

Introduction. An effective cellular immune response involves the host's ability to recognize and respond to a variety of antigens. The third complementary region (CDR3) of the T-cell receptor (TCR) is the site of antigen recognition. Recombination events within the genetic elements coding for CDR3 lead to the generation of diversity for specific antigen recognition. These recombinations result in different sizes of the mRNA/cDNA encoding CDR3. The preterm infant is unusually susceptible to certain T-cell mediated infections. The ability of the preterm infant's TCR repertoire to diversify has not been previously characterized. Objective. To describe the developmental changes of T-cell receptor diversity generation during gestation. Design. Reverse transcriptase/polymerase chain reaction was performed on umbilical cord or peripheral blood lymphocytes using a constant region primer and 26 Vβ family specific primers. The final PCR products were analyzed on a 5% acryalmide gel. Each V-specific amplification results in a number of bands representing rearrangements of the TCR Vβ chain gene segments. Analysis of the absolute CDR3 size was accomplished with an oligonucleotide primer directed against a conserved region of the 26 Vβ families and a constant region primer by PCR amplification. Results. The CDR3 length from 25 week gestation neonates was six base pairs (two amino acids) shorter than corresponding CDR3 length of adults. Term gestation neonates had CDR3 lengths which were three base pairs (one amino acid) shorter than those of adults. Samples from 24-28 week gestation had no limitation of Vβ family expression. Oligloclonal expansion was more common in infants as compared to adults (p=0.03). Beyond 29 weeks gestation most infants had more than one oligoclonal expansion with concomitant restricted CDR3 expression within that Vβ family. Conclusions. T-cell receptors undergo maturation during gestation and postnatally which is reflected by a lengthening of the antigen binding region of the TCR. The naive repertoire found in most infants 24-28 weeks gestation appears diverse; however, in some infants oligoclonal expansions and marked restrictions of other CDR3s within the same Vβ family may be due to in utero antigenic challenge. Limitation of T-cell repertoire in response to antigenic challenge differs from that of the adult. We speculate that the shorter CDR3 region and unusual response to antigen may contribute to the neonate's predisposition to T-cell mediated infection.
Effects of serotonin on induced epileptiform activity in CA1 pyramidal neurons of genetically epilepsy prone rats

Abstract The seizure susceptibility in genetically epilepsy prone rats (GEPRs) is reported to be caused by abnormalities in several neurotransmitter systems including the serotonergic system. Among the reported abnormalities is a decrease in brain serotonin content. Therefore, we examined the effects of exogenous serotonin on brain slices from the severe seizure strain of GEPRs (GEPR-9s). We employed conventional electrophysiological techniques to record from CA1 pyramidal neurons of hippocampi of GEPR-9s. The membrane resting potential and input resistance of the GEPR-9 CA1 pyramidal neurons were not different from those of the Sprague–Dawley rats. Serotonin (20 μM) inhibited the directly and synaptically evoked action potentials in GEPR-9 CA1 neurons, as it did in the Sprague Dawley neurons, but only in some and not all of the neurons tested (blocked the directly evoked potentials in 57% and synaptically evoked potentials in 33.3% of the total neurons). This inhibition was also accompanied by hyperpolarization and reduction of membrane input resistance. In the bicuculline-treated brain slices of the GEPR-9, serotonin inhibited the epileptiform bursts causing concurrent hyperpolarization and reduction in membrane input resistance. The effects of the selective serotonin 5-HT 1A receptor agonist, 8-OH-DPAT (20 μM) on GEPR-9 pyramidal CA1 neurons were similar to those of serotonin, except the magnitude of hyperpolarization and reduction of membrane input resistance were less than those produced by serotonin. We conclude that the apparent decrease in sensitivity of the GEPR-9 CA1 pyramidal neurons to serotonin may represent a deficiency of serotonin 5-HT 1A receptor.
Pitch of infant crying and caregiver responses in a natural setting

Abstract The naturally occurring cries of 13 infants in a day-care center were tape-recorded and spectrum-analyzed for the peak fundamental frequency. Caregivers' responses to higher-pitched cries were rated by observers as more urgent, and they more frequently included additional attempts to soothe the infant. These results provide some of the first ecologically valid evidence that the pitch of infant crying is related to the urgency and nature of caregivers' responses.
Emotion understanding, theory of mind, and prosocial orientation: Relations over time in early childhood

Data were collected when children were 42, 54, and 72 months of age (Ns=210, 191, and 172 for T1, T2, and T3, respectively). Children's emotion understanding (EU) and theory of mind (ToM) were examined as predictors of children's prosocial orientation within and across time. EU positively related to children's sympathy across 2.5 years, and T1 EU positively related to parent-reported prosocial orientation concurrently and across 1 year (T2). T2 ToM positively related to parents' reports of sympathy and prosocial orientation concurrently and 18 months later (T3); in contrast, T3 ToM did not relate to sympathy or prosocial orientation. T2 ToM accounted for marginally significant variance (p<0.058) in T3 mother-reported prosocial orientation over and above that accounted for by T2 prosocial orientation. Fostering the development of EU and ToM may contribute to children's prosocial orientation.
Growth, osmotic downshock resistance and differentiation of Bacillus subtilis strains lacking mechanosensitive channels.

Previous work has shown that the mechanosensitive (MS) channel of large conductance (MscL) is essential for preventing lysis of Bacillus subtilis log phase cells upon a rapid, severe osmotic downshock. Growing cells of B. subtilis strains lacking MscL and one or more putative MS channel proteins of small conductance (YhdY, YkuT and YfkC) showed even higher sensitivity to an osmotic downshock. The effect was greatest for a strain lacking MscL and YkuT, and a strain lacking all four MS channel proteins had a similar phenotype. These defects were complemented by expression of either MscL or YkuT in trans. All MS channel mutant strains ultimately became resistant to osmotic downshock in stationary phase but at varying times, with mscL ykuT strains taking the longest time to become resistant. Expression of β-galactosidase from gene fusions to lacZ showed modest expression of ykuT and lower levels of expression of yhdY and yfkC when strains were grown in medium containing high salt. Sporulation of all MS channel mutant strains was normal, and the mutant spores germinated normally with l-alanine or dodecylamine.
Friction and wear behavior of aluminum-graphite composites as a function of interface and fiber direction

Abstract The friction and wear behavior of aluminum-graphite fiber composites was examined as a function of the interfacial reaction zone. Sliding wear tests were performed on three different fiber orientations on a standard pin-on-disk tribology machine. The counterface was made of gray cast iron with a surface hardness of 92 HRB. The wear rate and friction coefficient were found to decrease exponentially with sliding time and eventually reached a steady state condition. This was attributed to the development of a lubricating transfer film on the sliding surface. The wear mechanism was investigated through the use of scanning electron microscopy analysis. A wear model was developed for specimens worn with fibers parallel to the sliding direction. This model incorporates three dominant wear mechanisms: (1) matrix removal by delamination, (2) fiber wear due to plowing and (3) fiber pull-out. The model was evaluated numerically and was found to agree with the experimental data. The model predicts that whenever fiber pull-out is a contributing mechanism in the wear, the wear rate is an exponential function of the normal load. In contrast, the wear rate of composites is proportional to the normal load in the absence of fiber pull-out.
Intestinal stricture following seat belt injury in children

Abstract The most commonly reported intestinal injury from seat belts in children is perforation. A rarely reported late sequela following this type of injury is posttraumatic intestinal stricture (PTIS). A review of the literature reveals a common clinical pattern of presentation in children and adults but an apparent difference in the pathophysiologic mechanism between the pediatric and adult patient. Recent.y, we treated two children with PTIS. Each case is discussed, and a pathophysiological mechanism for this injury in children is proposed. Recommendations are made for the evaluation and treatment of these uncommon complications of seat belt-related blunt intestinal injury.
Behavior of Actinide Ions During Sludge Washing of Alkaline Radioactive Wastes

It is difficult to accurately predict actinide behavior during the alkaline leaching of Hanford's radioactive sludges due to the diverse chemical and radiolytic conditions existing in these wastes. The results of Pu dissolution during experimental washing of sludge simulants from the BiPO{sub 4} Redox, and PUREX processes shows that {le} 2.l% Pu is dissolved during contact with alkaline media, but up to 65.5% Pu may be dissolved in acidic media. The dissolution of Cr, Fe, Nd, and Mn has also been observed, and the results of solid state, radioanalytical, and spectroscopic investigations are detailed.
Localization using boundary sensors: An analysis based on graph theory

We consider sensors, such as fibers, lasers, and pyroelectric motion detectors, that fire when objects cross a boundary. A moving object can be localized by analyzing sequences of boundary crossings. We consider the number of distinct sequences and object positions that can be achieved using boundary sensors in one- and two-dimensional spaces. For 1D systems we use representations of sensor sequences on graphs to derive limits on the number of object locations that can be monitored by a given sensor population and sequence length. For 2D systems we show that in certain circumstances the ratio of the number of unique sensor sequences to the number of unique object paths is exponential in the sequence length and we argue that the probability of unique identification is high for sufficiently large sequences. We also prove the triangle grid can track an object with error limited to a small neighborhood.
The chromaffin vesicle and the energetics of storage organelles

Abstract In the chromaffin vesicle, energy for amine transport is provided by a proton-translocating adenosine triphosphatase. The ATPase pumps protons into the vesicle; a pair of protons is then exchanged for each catecholamine taken up. In terms of transport, the adrenal chromaffin vesicle is an important model for nonmitochondrial organelles of all types. These organelles include adrenergic synaptic vesicles, other secretory and neurotransmitter storage vesicles, and lysosomes and other intracellular organelles as well. The membranes of these organelles all possess an ATPase that pumps H + ions into the vesicles. This proton pump presumably drives the transport of ions and molecules into the organelle and powers other energy-requiring functions of the membrane.
Microstructure of Y2O3 Fluxed Hot‐Pressed Silicon Nitride

Detailed microstructural analysis of a 10 mol% Y/sub 2/O/sub 3/ fluxed hot-pressed silicon nitride reveals that, in addition to the yttrium-silicon oxynitride phase located at the multiple Si/sub 3/N/sub 4/ grain junctions, there is a thin boundary phase 10 to 80 A wide separating the silicon nitride and the oxynitride grains. Also, x-ray microanalysis from regions as small as 200 A across demonstrates that the yttrium-silicon oxynitride, Y/sub 2/Si(Si/sub 2/O/sub 3/N/sub 4/), phase can accommodate appreciable quantities of Ti, W, Fe, Ni, Co, Ca, Mg, Al, and Zn in solid solution. This finding, together with observations of highly prismatic Si/sub 3/N/sub 4/ grains enveloped by Y/sub 2/Si(Si/sub 2/O/sub 3/N/sub 4/), suggests that densification occurred by a liquid-phase ''solution-reprecipitation'' process.
Short-period oscillations in outgoing longwave radiation over the summer monsoon region

Empirical orthogonal function (EOF) analysis is applied to daily outgoing longwave radiation (OLR) data to identify the major modes of oscillation over the summer monsoon region (7·5° N-32·5° N, 62·5° E-142·5° E) for two summers 1975 and 1977, each consisting of 120 days from 18 May through 14 September. Power spectrum analysis of time-dependent coefficients of the dominant eigenvectors exhibit spectral peaks in the long (<15 days) and short (4–8 days) period ranges. A detailed study is confined to 4–8 day filtered OLR perturbations. Standard deviation patterns of filtered OLR show large intraseasonal variability in the activity of monsoon disturbances over the Bay of Bengal. Lag-correlations reveal systematic westward movement of 4–8 day OLR perturbations from the Western Pacific to the Bay of Bengal in both summers.
Effective interactions in mixtures of silica microspheres and polystyrene nanoparticles.

We investigate the effect of small concentrations of highly charged nanoparticles on the stability of uncharged colloidal microspheres using large-scale simulations. Employing pair potentials that accurately represent mixtures of silica microspheres and polystyrene nanoparticles as studied experimentally, 1 we are able to demonstrate that nanoparticle-induced stabilization can arise from a relatively weak van der Waals attraction between the colloids and nanoparticles. This demonstrates that the nanoparticle haloing mechanism 2 for colloidal stabilization is of considerable generality and potentially can be applied to large classes of systems. The range of optimal nanoparticle concentrations can be tuned by controlling the attraction between colloids and nanoparticles.
Pattern of Past Performance and Expected Future Performance: A Reversal of the Unexpected Primacy Effect

Stimulus students of varying race (black vs. white) and social class (lower vs. middle) were portrayed as showing either an ascending or descending pattern of past success to Introductory Psychology or Elementary Education subjects. Subjects then estimated the future success of the stimulus student. The results indicated a recency effect in expected future performance-a performer whose scores showed an ascending pattern of success was expected to outperform those exhibiting a descending pattern of success. Black students were also expected to outperform white students, but only when they had shown increasing success; for descending success patterns, race did not differentially affect expected performance estimates. Possible explanations for the recency finding were presented and focused on the phenomenal status of ability and the prescriptions accompanying the institutionalized role of teacher. Implications regarding the differential credit for success to students were discussed.
CAPITAL STRUCTURE MANAGEMENT AS A MOTIVATION FOR CALLING CONVERTIBLE DEBT

Using a matched-pairs methodology, we present empirical evidence of systematic changes within a corporation that are associated with calls of convertible debt. We find that calling firms experience significantly greater growth than noncalling firms in the same industry, as measured by retained earnings and long-term debt. Also, the converted debt provides a significant source of new book equity, and calling firms issue significantly less other new equity. The pattern of growth in balance sheet accounts is consistent with the pecking order hypothesis and supports the notion that some firms call convertible debt to reduce their total cost of obtaining additional external financing. The evidence also shows that, on average, calling firms experience a significant decline in their leverage ratio based on book value but no significant change in their leverage ratio based on market value of equity. This is consistent with the call's being used as part of the firm's management of its capital structure.