cssi/SciSciGPT-SciSciNet huggingface dataset:
Magnesium binding by Escherichia coli ribosomes.

Magnesium binding by ribosomes and ribosomal RNA from Escherichia coli has been studied as a function of the free magnesium concentration. At 10−2 M -Mg2+ the 70 s and 100 s components bind at least three times more magnesium than they do at 10−4 M -Mg2+ when they are completely dissociated into their 30 s and 50 s subunits. Between 10−4 M - and 10−2 M -magnesium, a pair of 30 s and 50 s particles take up about 1600 magnesium ions, thus approaching a ratio of bound Mg2+ to P of 0·5. Increasing concentrations of potassium decrease the extent of magnesium binding by competition for anionic sites. Magnesium is nevertheless bound preferentially, even at potassium to magnesium ratios greater than 10 to 1. Parallel studies have been carried out on the magnesium binding of ribosomal RNA. These studies support the suggestion of Ts'o and his co-workers that virtually all the magnesium bound by the ribosomes is bound by the RNA. Binding to a greater extent than one magnesium atom for every two RNA phosphates has been observed, but this effect appears to be correlated with the precipitation of the RNA at high ionic strengths. Almost all of the phosphate groups of the RNA must be available for magnesium binding in the completed ribosome, for removal of the protein moiety makes available at most 12% more binding sites.
Transport through hemoglobin solutions: a sensitivity analysis.

Abstract A sensitivity analysis has been used in an attempt to elucidate the mechanism of the interaction of the effect of carbon dioxide diffusion upon the facilitated transport of oxygen in dilute hemoglobin solutions. The primary mechanism of oxygen augmentation is shown to be the parallel diffusion of the oxyhemoglobin association, as had been previously suggested. At film thicknesses in the range of 10 −4 to 10 −3 cm, the carbaminyl hemoglobin reaction begins to alter the oxyhemoglobin gradient (steepening it in the case of counter-current oxygen-carbon dioxide fluxes) thereby affecting the augmentation. The bicarbonate reaction exerts a similar, somewhat stronger, effect at phase lengths of 0.01 to 0.1 cm.
Upregulated autophagy protects cardiomyocytes from oxidative stress-induced toxicity

Autophagy is a cellular self-digestion process that mediates protein quality control and serves to protect against neurodegenerative disorders, infections, inflammatory diseases and cancer. Current evidence suggests that autophagy can selectively remove damaged organelles such as the mitochondria. Mitochondria-induced oxidative stress has been shown to play a major role in a wide range of pathologies in several organs, including the heart. Few studies have investigated whether enhanced autophagy can offer protection against mitochondrially-generated oxidative stress. We induced mitochondrial stress in cardiomyocytes using antimycin A (AMA), which increased mitochondrial superoxide generation, decreased mitochondrial membrane potential and depressed cellular respiration. In addition, AMA augmented nuclear DNA oxidation and cell death in cardiomyocytes. Interestingly, although oxidative stress has been proposed to induce autophagy, treatment with AMA did not result in stimulation of autophagy or mitophagy in cardiomyocytes. Our results showed that the MTOR inhibitor rapamycin induced autophagy, promoted mitochondrial clearance and protected cardiomyocytes from the cytotoxic effects of AMA, as assessed by apoptotic marker activation and viability assays in both mouse atrial HL-1 cardiomyocytes and human ventricular AC16 cells. Importantly, rapamycin improved mitochondrial function, as determined by cellular respiration, mitochondrial membrane potential and morphology analysis. Furthermore, autophagy induction by rapamycin suppressed the accumulation of ubiquitinylated proteins induced by AMA. Inhibition of rapamycin-induced autophagy by pharmacological or genetic interventions attenuated the cytoprotective effects of rapamycin against AMA. We propose that rapamycin offers cytoprotection against oxidative stress by a combined approach of removing dysfunctional mitochondria as well as by degrading damaged, ubiquitinated proteins. We conclude that autophagy induction by rapamycin could be utilized as a potential therapeutic strategy against oxidative stress-mediated damage in cardiomyocytes.
Time and sex in the male mouse: temporal regulation of infanticide and parental behavior.

Infanticide is a violent but successful reproductive strategy found in many mammals, particularly rodents. In male house mice (Mus domesticus and M. musculus) the act of ejaculation provides a reliable neural signal for timing the birth of their offspring. However, a unique chronobiological aspect of this phenomenon is the extraordinary temporal latency that can occur between the stimulus (coital ejaculation) and its adaptive neural response (male mice cease killing pups and behave parentally toward them instead). Specifically, the inhibition of infanticide is often time delayed for many days after a male ejaculates, but virtually always occurs before or around the time his own sired offspring would be born 18-20 days later. Furthermore, infanticide spontaneously reemerges 50-60 days after mating. In CF-1 stock male mice this entire behavioral sequence is synchronized with the female's reproductive cycle, and occurs even in the total absence of social cues or changes in pituitary or gonadal hormones after...
Saccade trajectories evoked by sequential and colliding stimulation of the monkey superior colliculus

Using microstimulation we employed an explicit experimental control of activity in the superior colliculus at two sites within the motor map. We compared saccade metrics and dynamics evoked at each site independently with those caused by sequential presentation and collisions of the two stimulation trains. Essentially, we forced controlled spatio-temporal patterns of activity into the saccade control circuit with various timing relationships from known sites within the collicular motor map, thus revealing the spatio-temporal transformation from superior colliculus to eye movement dynamics under experimentally controlled conditions. We extend prior findings about decreasing time intervals between sequential presentations of stimulations to include mid-flight combinations and dynamic modifications of trajectory. We explore how asynchronous collisions between two movements systematically engage a normalization mechanism of movement metrics, and demonstrate how dynamic patterns of activity across the SC motor map can create mid-flight curvature of movement through the post-collicular dynamics of a displacement controller. The explicit control addresses feasibility for systems control models and provides benchmark data for experimental verification of model mechanisms.
The Effect of Vitamin A Deficiency on Reproduction in Dairy Bulls

Summary Typical deficiency symptoms (total blindness, incoordination, emaciation, and extremely low blood plasma carotene and vitamin A values) were made to appear in 12 dairy bulls at different ages by adjusting the vitamin A intake. Seven of the animals (all that were tested more than twice) were proved fertile by artificially inseminated cows. The semen used was usually obtained in an artificial vagina but it had to be collected by massage from the animals that would not mount. These bulls were also fertile. Generally the semen was low in concentration, had a high percentage of abnormal sperm, a high pH, and did not store well. When gross vitamin A deficiency symptoms appeared before the expected breeding age, the bulls failed to breed; when symptoms appeared at about the expected breeding age, the bulls frequently failed to breed shortly thereafter; but when the deficiency became apparent after they had started breeding, this capacity was maintained. At autopsy all the bulls were found to have cystic pituitary glands. The degree of damage to the anterior lobe varied, probably less than one-fifth normal tissue remaining in four bulls, —three of which incidentally were among those proved fertile. The animals exhibiting avitaminosis A earliest in life generally showed the greatest damage to this gland. The epithelium of the seminiferous tubules was found to have undergone degeneration—some extensively. This epithelium, the anterior lobe of the pituitary gland, and the bones of the skull were the only tissues of several examined that had become altered. Four of the bulls were fed rations supplemented with small amounts of.carotene (8 to 11 micrograms per pound) after the appearance of avitaminosis A. This caused them to start breeding but the quality of the semen generally was not substantially improved. The testes of these animals were generally in better condition at autopsy than those of animals that did not get supplemented rations—giving evidence that carotene had brought about repair. The germinal epithelium of one vitamin A deficient bull whose ration was supplemented but whose feed consumption was restricted was badly damaged, indicating failure to regenerate. It is likely that gross vitamin A deficiency symptoms will appear before severe impairment to a bull's reproductive performance will occur.
Nonparametric Testing For Simple Regression Under Progressive Censoring With Staggering Entry And Random Withdrawal

In the context of (multi-center) clinical trials and life testins problems, a general model incorporating both the staggering entry and random withdrawal and pertaining to a simple regression problem (including the two-sample location problem as a special case) is conceived, and, within this framework, a scheme allowing progressive censoring (continuous monitoring of experimentation from the beginning) is developed along with the proposal for and study of some nonparametric testing procedures, The proposed tests rest on the construction of certain two-dimensional time-parameter stochastic processes from a triangular array of progressively censored linear rank statistics and their weak convergence to appropriate Gaussian functions. Asymptotic properties of these procedures are studied. A computer program pertaining to the numerical computations and practical administrations of these testing procedures is also provided at the end.
Heat Transfer Analysis of Human Cell Culture Under RF Exposure

A 2.45 GHz radio frequency (RF) exposure system was designed and used to study the RF effects on the genome-wide gene expression in cultured human cells. In this system, a T-25 culture flask, which contains 10 × 106 cells in a 10ml medium, is placed in a WR 340 waveguide. The waveguide serves as an environmental chamber. The source is a pulsed magnetron for obtaining a high electric field with the specific absorption rate (SAR) at approximately 10 W/kg. In order to ensure the non-thermal effect, the system was designed to maintain a temperature of 37°C. In this research, the heat transfer analysis of the system was conducted using the computational fluid dynamic (CFD) software FLUENT® coupled with the finite element software, High Frequency Structural Simulation (HFSS) by Ansoft. The electric field was first analyzed by using HFSS to calculate the SAR distribution as a heat source input for CFD calculations. The fluid flow and temperature distributions within the flask were then analyzed using FLUENT®. The results were validated experimentally by measuring the temperatures with fluoroptic thermometer probes as well as by examining the level of heat shock gene expression. These results provide useful information for a better understanding and controlling of the operating conditions of the system.Copyright © 2005 by ASME
Flux transfer events in global numerical simulations of the magnetosphere

[1] A magnetohydrodynamic numerical simulation model is used to study nonsteady features of magnetic reconnection between southward interplanetary magnetic field (IMF) and the geomagnetic field. The magnetic field near the dayside magnetopause intermittently shows the bipolar normal magnetic field and field-aligned flow features that are similar to the observed flux transfer events. The results show that the magnetic signature extends outward into the magnetosheath and inward into the magnetosphere. The magnetic features are not steady, and they evolve as they propagate along the magnetopause. Magnetic field lines are traced from the magnetopause in order to show the connectivity of the field from the ionosphere to the solar wind. The results shown are consistent with Russell and Elphic's [1978] interpretation of the magnetic signals as evidence of nonsteady reconnection between the IMF and the geomagnetic field. Finally, we suggest a merging mechanism along the dayside magnetic null-null line that naturally leads to the observed magnetic structure.
Estimating latent distributions in recurrent choice data

This paper introduces a flexible class of stochastic mixture models for the analysis and interpretation of individual differences in recurrent choice and other types of count data. These choice models are derived by specifying elements of the choice process at the individual level. Probability distributions are introduced to describe variations in the choice process among individuals and to obtain a representation of the aggregate choice behavior. Due to the explicit consideration of random effect sources, the choice models are parsimonious and readily interpretable. An easy to implement EM algorithm is presented for parameter estimation. Two applications illustrate the proposed approach.
Empowering women through ict-based business initiatives: An overview of best practices in e-commerce/e-retailing projects

Information and communication technologies (ICTs) have been increasingly promoted as a key solution for comprehensive development, poverty eradication and the empowerment of historically disadvantaged groups, such as women and minorities in the Global South. ICT-based business initiatives, and e-commerce projects in particular, have been hailed as “potential goldmines” for women's empowerment. However, research and experience show that to be successful, projects must balance the need to overcome structural barriers to women's advancement with sensitivity to the limited space within which many women in the Global South navigate. In this paper, we review literature on ICT and empowerment of women, drawing upon several e-commerce/e-retailing projects as case studies to identify a set of best practices that underlie a successful project: 1) government and institutional support, 2) societal involvement, 3) training and empowerment, 4) expansion of market access, and 5) managerial best practices. We anticipate that the insights generated by this study will be useful both for purposes of effective program development and policy design.
Spatial Disorder and Degradation Kinetics in Intrinsic Biodegradation Schemes

The restoration of contaminated soils by intrinsic biodegradation employs microorganisms in the subsurface that degrade the contaminant substrate infiltrating the subsurface matrix. The outcome of intrinsic biodegradation has been difficult to predict. The authors examine a source of the difficulty with a computational model of diffusive-reactive transport that introduces spatial disorder in the arrangement of the degrading microorganisms. Spatial disorder alone, even on the small scales that characterize the distance between aggregates of microorganisms, is enough to induce a wide range of times to complete the degradation to an arbitrary limit. The mean time for the concentration to achieve the limit becomes twice that for the case of spatial order. Bounds on the range of the effective degradation kinetics can be obtained by computing the distribution of times to complete degradation.
The Effect of Temperature Mishandling at Various Times During Storage on Detection of Temperature Abuse of Fresh Broiler Chicken Carcasses

Experiments were conducted to determine the effect that temperature mishandling at various times during storage has on detection of temperature abuse of fresh broiler chicken carcasses using populations of mesophilic and coliform bacteria as indicators of abuse. Forty-five broiler carcasses were used in each of three independent trials. Five carcasses were analyzed at day of collection (Treatment 0 control). Five carcasses, on each day of the next 7 d (Treatments 1 to 7) were temperature-abused for 12 h at 25 C, stored at 3 C until Day 9, and then sampled. The five remaining carcasses were stored at 3 C and sampled on Day 9 (Treatment 8 control). Carcasses were sampled using a whole carcass rinse procedure and assayed for aerobic plate counts (APC), total coliform counts (TCC), impedance detection times (DT), and impedance coliform detection times (DTCM). Although significant differences were noted using all four microbiological methods, temperature abuse at different times during storage had no consistent effect on populations of mesophilic or coliform bacteria; therefore, temperature abuse determinations may be conducted without regard to the day on which the carcasses were subjected to elevated temperatures.
Development of a behavior attributed to the frontal lobes and the relationship to other cognitive functions

This study investigates the developmental relationship between a neuropsychological measure, the Verbal Retroactive Inhibition (VRI) task, which is presumed to be mediated by the frontal lobes, and a measure of selective attention, the central‐incidental (C‐I) task, drawn from traditional developmental psychology. Thirty children ages 7, 10, and 13 years, were administered the two tasks. Performance on the VRI task improved significantly from ages 7 to 10 and again from ages 10 to 13. The central score of the C‐I task, which measures the ability to selectively attend to relevant stimuli, also showed developmental improvement, but significantly so only between ages 10 and 13. The mean number of incidental items remembered did not change significantly across the three ages. Correlational analyses showed that the central and incidental measures were independent after age 7. At age 13, but not before, performance on the VRI task was significantly correlated with the incidental score, suggesting the maturation...
Platelet adhesiveness and aggregation: the collagen:glycosyl, polypeptide:N-acetylgalactosaminyl and glycoprotein:galactosyl transferases of human platelets.

Abstract Four glycoprotein:glycosyl transferases were identified, purified, and characterized from human platelets. The enzymes present were collagen:glc, collagen:gal, polypeptide:galNAc, and glycoprotein:gal; the fetuin:glcNAc transferase was absent. Each of the 4 transferases was found to be almost exclusively bound to the platelet plasma membrane. Incubation of platelet homogenates without exogenous acceptors yielded no transfer of monosaccharide, indicating the complete lack of endogenous acceptors. These results lead to the interesting speculation that the transferases may not be responsible in the mature platelet for glycoprotein synthesis at all, but rather that they may function for intercellular adhesion and the primary step in hemostasis, the adhesion of collagen to platelets.
Field theory of paths with a curvature-dependent term

A novel theory of paths, in which configurations are weighted according to their curvature as well as their length, is developed.
Effect of Tillage System, Phorate, and Cultivar on Tomato Spotted Wilt of Peanut

Tomato spotted wilt (TSW) has become a limiting factor to peanut (Arachis hypogaea L.) production in the southeast United States over the past 6 yr. Cultivars are now selected based on their resistance to TSW and planted during time periods to reduce the incidence of TSW. Three peanut cultivars with different resistance to TSW were used ('Georgia Green', 'MDR98' and 'SuuOleic 97R'). Conventional- or strip-tilled plots were established after winter wheat (Triticum aestivum L.) in 2000 and 2001 in Marianna, FL. Stand count, severity of TSW, and yield were recorded. Plots were irrigated as needed. Stand count was 10% less in the strip-tilled plots in both 2000 and 2001. Stand count was affected by cultivar used, with Georgia Green and SunOleic 97R having 20% higher populations than MDR98. Phorate [O,O-diethyl,S-(ethylthio)methyl phosphorodithioate] treatment had 7% less stand count in 2001 but not in 2000. Tomato spotted wilt severity was 50% less in strip-tilled plots in 2000, but there was no difference in 2001. Cultivar affected severity of TSW every year but not consistently. Application of phorate did not affect TSW. In 2000 (a droughty year), the strip-tilled plots had greater yield (2510 vs. 1900 kg ha -1 ) averaged across cultivars. MDR98 had the highest yield across treatments in 2000, but yield was not different among cultivars in 2001. Application of phorate did not affect yield in either year. In the strip-tilled plots, soil moisture was 30% greater and plant canopy 3 to 5°C cooler during 2000 when plants were visibly drought stressed. Use of phorate had no effect on TSW or yield and its use for TSW control is not recommended. Cultivar selection did influence TSW severity and should be considered as part of a TSW control program. Strip tillage resulted in greater yields than conventional tillage in an abnormally dry year.
Abstract 3270: Combination strategy to circumvent the acquired resistance to VEGF receptor tyrosine kinase inhibitor in M24met melanoma in mice

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Anti-angiogenic therapy targeting the tumor vasculature has demonstrated clinical benefits in certain types of tumors. However, many patients develop resistance and eventually progress on anti-angiogenic therapy. The mechanism of resistance is largely unknown and warrants extensively investigation. We developed a human xenograft tumor model (M24met/R) in mice that has acquired resistance to VEGF receptor tyrosine kinase inhibitors (VEGFR TKI), by chronically treating the parental M24met tumors (M24met/P) with PF-0337210 (20-40 mg/kg, QD, PO) and serially passaging resistant tumor fragments in nude mice. M24met/R tumors were also resistant to axitinib, a selective VEGFR TKI in late stage clinical development. Immunohistochemical (IHC) staining revealed higher degree of hypoxia and lower microvessel density in M24met/R tumors compared to parental tumors. Compared with those in M24met/P, vessels in M24met/R tumors appeared to be larger in diameter and more mature as shown by high incidence of co-localization between endothelial cells and perivascular cells (CD31+Desmin+). Microarray analysis of tumor lysates (human UA133 2.0, mouse 430 2.0 chip) revealed distinct gene expression profiles between M24met/R tumors and size-matched M24met/P tumors. Of note, several angiogenesis-related genes, including human VEGF, bFGF, integrin α5β1, IL-8, PDGF,CSF and murine VEGF, integrin α5β1, ALK1 (activin receptor-like kinase 1), IL-8, c-Met, IL-6 were up-regulated in M24met/R tumors, whereas murine VEGFR1 and 2, PROX1, PDGFR and endogenous angiogenic inhibitor TSP-1 were down-regulated in the resistant tumors. The above observations were verified with ELISA and/or IHC. Next, targeted combination approaches were applied in an attempt to circumvent M24met/R resistance to axitinib. Concurrent administration of axitinib plus either anti-IL-8 monoclonal antibody (mAb), c-Met inhibitor, anti-integrin α5 mAb or anti-ALK1 mAb significantly improved anti-tumor efficacy compared to single agents alone. IHC analyses showed that combinatorial therapy of anti-ALK1 plus axitinib reduced the amount of CD31+Desmin+ vessels compared to axitinib alone, suggesting that targeting ALK1 destroyed VEGFR TKI-resistant vessels. Together, our results suggested that multiple alternative angiogenic factors contributed to the acquired resistance of M24met/R melanoma to VEGFR TKI. Combination treatment using inhibitor of IL-8, c-Met, integrin α5β1 or ALK1 with VEGFR TKI may represent a new strategy to mitigate resistance to VEGFR TKI in the clinic. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3270. doi:10.1158/1538-7445.AM2011-3270
Conversion and the import problem: a confluence of opportunities

The defense electronics industry is again faced with the prospect of cutbacks, which brings the problem of its conversion once more to the fore. At the same time, the growth of imports presages sharp competition for U.S. industry for the products it can devise to take up the slack. Further, the electronics industry has a quality problem, in its military, industrial, and consumer sectors. In this article, the writer suggests that the industry's displaced technical talent should be organized to tackle systematically its scientific, engineering, and economic problems in order to put it ahead once more. As a vehicle of change, he proposes a National Technology Foundation to oversee the program and to undertake tasks now beyond the scope of individual companies.
Effects of Microstructure on the Deformation Mechanisms in Silicon Nitride

Changes in phase composition and morphology were investigated in silicon nitride (Si{sub 3}N{sub 4}) both before and after compressive deformation testing. Different additive systems were used to prepare Si{sub 3}N{sub 4} specimens, resulting in either an initial {alpha}-phase or {beta}-phase microstructure. Constant-strain-rate compression tests were used to evaluate the differences in the strain-rate dependency of the flow stress for the two phases. A flow-stress dependency of n = 1 was observed in the {beta}-phase specimens, compared to an n value that approached 2 in the {alpha}-phase specimens.
Preemptive Renal Transplantation: Why Not?

Dialysis has been the long-established initial choice of treatment for persons with end-stage renal disease. Transplantation before dialysis, or preemptive renal transplantation (PRT), has been controversial because of the paucity of clinical evidence that has clarified the benefits vs. risks of this approach. However, several recent observational analyses indicate that PRT is the optimal strategy to benefit patients requiring renal replacement therapy. This current review will discuss the advantages that are associated with PRT, and will summarize studies that have investigated the impact of the timing of transplantation on outcomes. We will also discuss the utility of PRT from various perspectives, and describe the challenges ahead in expanding the opportunity of PRT for more patients.
Perfect duality theory and complete solutions to a class of global optimization problems

This article presents a complete set of solutions for a class of global optimization problems. These problems are directly related to numericalization of a large class of semilinear nonconvex partial differential equations in nonconvex mechanics including phase transitions, chaotic dynamics, nonlinear field theory, and superconductivity. The method used is the so-called canonical dual transformation developed recently. It is shown that, by this method, these difficult nonconvex constrained primal problems in can be converted into a one-dimensional canonical dual problem, i.e. the perfect dual formulation with zero duality gap and without any perturbation. This dual criticality condition leads to an algebraic equation which can be solved completely. Therefore, a complete set of solutions to the primal problems is obtained. The extremality of these solutions are controlled by the triality theory discovered recently [D.Y. Gao (2000). Duality Principles in Nonconvex Systems: Theory, Methods and Applications, ...
Toleration, Liberty and Truth: A Parable

The Citizens of the United States of America have a right to applaud themselves for having given to mankind examples of an enlarged and liberal policy: a policy worthy of imitation. All possess alike liberty of conscience and immunities of citizenship. It is now no more that toleration is spoken of, as if it was by the indulgence of one class of people, that another enjoyed the exercise of their inherent natural rights. For happily the Government of the United States, which gives to bigotry no sanction, to persecution no assistance requires only that they who live under its protection should demean themselves as good citizens, in giving it on all occasions their effectual support.I
Partial suppression of a strongly expressed tonoplast sucrose transporter affects water use and carbon partitioning in Populus

Sucrose export from source organs, and its subsequent distribution among differentiating organs in wood-forming stems and elsewhere depends on the activity of sucrose transporters (SUTs). There are no comprehensive reports on SUT function in temperate tree species valued for their lignocellulosic biomass. To begin to address this gap, the SUT gene family was characterized and functionally analyzed in transgenic P. tremula x alba. The Populus SUT family features the three major groups characteristic of other dicots. In general, functionally distinct SUTs fall into different phylogenetic groups. Group-1 PtaSUT3 transcripts localize to leaf vascular traces and stem developing xylem; Group-4 PtaSUT4 to leaf spongy mesophyll, stem developing xylem, cambium and phloem; Group-2 PtaSUT5/6 to all leaf cells, stem developing xylem and phloem fibers. The SUT4 ortholog of Populus differs from that of other model plants in encoding a vacuolar transporter that is unusually well expressed in source leaves compared to Group-1 and 2 SUT genes. SUT4-RNAi transgenic plants demonstrated a shift of biomass allocation from stem to leaf in both nitrogen (N)-replete and N-limited plants. In those plants, sucrose exhibited a complex pattern of hyper-accumulation in exporting leaves and vascular tissues of the stem, and decreased accrual in the shoot tip and sink leaves. RNAi silencing of SUT4 reduced water uptake during drought simulation without significantly affecting overall shoot biomass accumulation.
Localization of Spin and Charge in Phenalenyl-Based Neutral Radical Conductors

We report the development of an experimentally based structural analysis to examine the degree of localization of the spin and charge in the phenalenyl-based neutral radical molecular conductors—the results motivate a reinterpretation of the electronic structure of a number of the radicals that we have reported over the past 10 years. The analysis is based on the well-known relationship between bond order and bond length and makes use of the experimental bond distance deviations between the molecular structure of the radical and its corresponding cation. We determined the single crystal X-ray structure of the ethyl radical (1) at 11 temperatures between 90 K and room temperature so that we could follow the evolution of the structure and the electron density distribution through the magnetic phase transition that occurs in the vicinity of 140K. We show that the enhanced conductivity in the dimeric ethyl (1) and butyl (3) radicals at the magnetic phase transition results from the development of a complex, b...
Extracellular superoxide dismutase (EC-SOD) quenches free radicals and attenuates age-related cognitive decline: opportunities for novel drug development in aging

Superoxide dismutase (SOD) is one of the most effective mechanisms in physiology for inactivating reactive oxygen species. Elevated SOD activity can be therapeutically useful by protecting against oxidative stress-induced neurotoxicity. Acutely increased extracellular-SOD (EC-SOD) activity protects against neurobehavioral impairment caused by acute ischemia. Chronically increased EC-SOD activity may also be therapeutically useful by protecting against chronic oxidative stress-induced neurobehavioral damage that accumulates during the aging process. We have found that mice with genetic overexpression of EC-SOD do not show the aging-induced decline in learning and memory that control, wild type mice show. From 14-22 months of age, the EC-SOD overexpressing mice have significantly better spatial learning working memory function than that of controls. This effect is specific to the aging period. Young adult EC-SOD overexpressing mice do not have better learning and memory function than controls. The beneficial effects of increased EC-SOD activity with aging may be achieved without risk of impairment during younger ages by chronically administering EC-SOD mimetics from mature adulthood into the aging period. Novel EC-SOD mimetics may be useful in attenuating aging-induced cognitive impairments and other aspects of physiological decline with aging.
Design considerations regarding ellipsoidal mirror based reflectometers

Hemi-ellipsoidal mirrors are used in reflection-based measurements due to their ability to collect light scattered from one focal point at the other. In this paper, a radiometric model of this energy transfer is derived for arbitrary mirror and detector geometries. This model is used to examine the imaging characteristics of the mirror away from focus for both diffuse and specular light. The radiometric model is applied to several detector geometries for measuring the Directional Hemispherical Reflectance for both diffuse and specular samples. The angular absorption characteristics of the detector are then applied to the measurement to address measurement accuracy for diffuse and specular samples. Examining different detector configurations shows the effectiveness of flat detectors at angles ranging from normal to 50°, and that multifaceted detectors can function from normal incidence to grazing angles.
Ion-Ion interactions at the selectivity filter. Evidence from K(+)-dependent modulation of tetraethylammonium efficacy in Kv2.1 potassium channels

In the Kv2.1 potassium channel, binding of K+ to a high-affinity site associated with the selectivity filter modulates channel sensitivity to external TEA. In channels carrying Na+ current, K+ interacts with the TEA modulation site at concentrations ≤30 μM. In this paper, we further characterized the TEA modulation site and examined how varying K+ occupancy of the pore influenced the interaction of K+ with this site. In the presence of high internal and external [K+], TEA blocked 100% of current with an IC50 of 1.9 ± 0.2 mM. In the absence of a substitute permeating ion, such as Na+, reducing access of K+ to the pore resulted in a reduction of TEA efficacy, but produced little or no change in TEA potency (under conditions in which maximal block by TEA was just 32%, the IC50 for block was 2.0 ± 0.6 mM). The all-or-none nature of TEA block (channels were either completely sensitive or completely insensitive), indicated that one selectivity filter binding site must be occupied for TEA sensitivity, and that one selectivity filter binding site is not involved in modulating TEA sensitivity. At three different levels of K+ occupancy, achieved by manipulating access of internal K+ to the pore, elevation of external [K+] shifted channels from a TEA-insensitive to -sensitive state with an EC50 of ∼10 mM. Combined with previous results, these data demonstrate that the TEA modulation site has a high affinity for K+ when only one K+ is in the pore and a low affinity for K+ when the pore is already occupied by K+. These results indicate that ion–ion interactions occur at the selectivity filter. These results also suggest that the selectivity filter is the site of at least one low affinity modulatory effect of external K+, and that the selectivity filter K+ binding sites are not functionally interchangeable.
Developmental effects of exposing Drosophila embryos to ether vapour.

Drosophila embryos at precise developmental stages were exposed to ether vapour. The defects in the resulting embryos and adults were observed. Ether disrupted embryogenesis in specific ways, causing defects primarily at the anterior of the embryo and disorganizing the arrangement of the segments. Adults showed deficiencies and duplications of many imaginal disc and histoblast derivatives. Phenocopies of the bithorax mutation which transforms metathorax to mesothorax were observed. They were first induced at the syncytial blastoderm stage, had their peak of production at the cellular blastoderm, and were no longer observed after the anterior and posterior midgut were partially invaginated. It was observed that not only are the haltere/wing transformations confined to the anterior compartment, but also leg 3 to leg 2 transformations only occurred in the anterior leg compartment.
High-throughput reactor system with individual temperature control for the investigation of monolith catalysts.

A high-throughput parallel reactor system has been designed and constructed to improve the reliability of results from large diameter catalysts such as monoliths. The system, which is expandable, consists of eight quartz reactors, 23.5mm in diameter. The eight reactors were designed with separate K type thermocouples and radiant heaters, allowing for the independent measurement and control of each reactor temperature. This design gives steady state temperature distributions over the eight reactors within 0.5°C of a common setpoint from 50to700°C. Analysis of the effluent from these reactors is performed using rapid-scan Fourier transform infrared (FTIR) spectroscopic imaging. The integration of this technique to the reactor system allows a chemically specific, truly parallel analysis of the reactor effluents with a time resolution of approximately 8s. The capabilities of this system were demonstrated via investigation of catalyst preparation conditions on the direct epoxidation of ethylene, i.e., on the e...
Lower level of synovial fluid interferon‐γ in HLA‐B27‐positive than in HLA‐B27‐negative patients with Chlamydia trachomatis reactive arthritis

Objectives. To compare the synovial fluid (SF) concentrations of various cytokines in rheumatoid arthritis (RA) and in reactive arthritis, and to look for a correlation between cytokine levels and the presence of HLA-B27 antigen in reactive arthritis patients. Methods. Concentrations of interleukin (IL) 10, IL-12, IL-18, interferon y (IFN-y) and tumour necrosis factor a (TNF-a) were determined by commercially available enzyme-linked immunosorbent assays (ELISA) in the SF from 48 patients with reactive arthritis, 33 with RA and 13 with osteoarthritis (non-inflammatory controls). Results. The SF concentrations of IL-10 were significantly lower in patients with reactive arthritis (median 2.3 pg/ml) than in RA patients (median 14.6 pg/ml). The SF levels of IFN-y were not significantly different but the ratios of IFN-y to IL-10 were significantly higher in patients with reactive arthritis (median 9.2) than in RA patients (median 0.83). When the subset of patients with Chlamydia trachomatis reactive arthritis was considered, the SF concentration of IFN-y was significantly lower in HLA-B27-positive (median 2.9 pg/ml) than in HLA-B27-negative patients (median 42.4 pg/ml). After 2 yr of follow-up, two HLA-B27-positive patients, who had low SF levels of IFN-y, had a chronic course of arthritis, whereas after 1 yr all HLA-B27-negative patients had complete resolution of arthritis. Conclusions. The lower IFN-y concentrations in HLA-B27-positive patients with C. trachomatis reactive arthritis could be related to the tendency of these patients to have more severe or chronic arthritis.
Brain metabolite alterations in young adults at familial high risk for schizophrenia using proton magnetic resonance spectroscopy.

Abstract Background Proton magnetic resonance spectroscopy (1H MRS) enables in-vivo measurement of several relevant brain metabolites and has provided evidence of a range of neurochemical abnormalities in schizophrenia, especially in glutamate and N-acetyl-aspartate (NAA). While individuals at high familial risk for schizophrenia (HR) exhibit some neurobiological findings observed in the disorder, 1H MRS findings and their clinical correlates are not well characterized in this population. Methods We compared 23 adolescent and young adult offspring of schizophrenia patients with 24 age- and sex-matched healthy controls using 1H MRS. We acquired multi-voxel, short TE 1H MRS measurements at 1.5 T and obtained metabolite concentrations of N-acetyl-aspartate (NAA), combined glutamate and glutamine (Glu + Gln) and choline-containing compounds (GPC + PC) for the left and right thalamus, anterior cingulate gyrus, and caudate. We also assessed the relationship between regional metabolite levels, clinical measures and brain volume in a subset of 16 high-risk and 15 control subjects. Results Compared to healthy controls, high-risk subjects showed reductions in NAA levels in all three regions (thalamus, caudate, and anterior cingulate cortex), increases in Glu + Gln in the thalamus and caudate, and increases in GPC + PC in the anterior cingulate. In HR, thalamic Glu + Gln concentration was positively correlated and thalamic NAA inversely correlated with measures of schizotypy. Anterior cingulate GPC + PC and caudate Glu + Gln were significantly correlated with attenuated psychotic symptom severity. Anterior cingulate NAA was correlated with executive function. Conclusions Our data suggest the occurrence of metabolic alterations in young relatives of schizophrenia patients similar to those seen in patients with established illness. The observed correlations with cognitive deficits and psychosis-related psychopathology suggest that these metabolic measures may have value as biomarkers of risk for schizophrenia.
A uniform continuity condition which is equivalent to Coleman's conjecture

At the Fifth International Conference on Nonlinear Oscillations (Kiev, 1970), Coleman [l] raised the question of whether or not a flow with a topologically hyperbolic stationary point is necessarily locally conjugate with some flow near a differentiably hyperbolic (generic) stationary point. We shall prove an affirmative result in the case where either the stable manifold or the unstable manifold has dimension one and we shall prove the equivalence of a uniform continuity condition in the general case. These affirmative results are contrasted with the recent counterexample by Neumann [2], which has both the stable manifold and the unstable manifold with dimension 2. Using Hartman’s theorem [3], it is easy to show that every differentiably hyperbolic stationary point on [w N is locally conjugate to the flow F~;,,~-,~ of the Standard Example, where
The Hasse norm theorem mod squares

For a Galois extension KF of global fields, char F≠2, it is known that the Hasse norm theorem mod squares is equivalent to the existence of a local-global principle for the transfer ideal JK/F of quadratic forms. When Gal(K/F)=(Z/2Z)k, the Hasse norm theorem mod squares holds although the usual Hasse norm theorem may fail. In this paper we analyze the case when Gal(K/F)=Z/2Z⊕Z/2kZ, k≥2. In particular, the Hasse norm theorem mod squares holds if and only if the Hasse norm theorem holds (Theorem I). A corollary shows that if a square in F is a local norm from K, then it is a global norm from K (Theorem II).
A Monte Carlo Finite Element Method for Determining the Young’s Modulus of Polymer Nanocomposites Using Nanoindentation Data

This article presents a Monte Carlo finite element method (MCFEM) for determining the Young’s modulus (YM) of polymer nanocomposites (PNC) using Nanoindentation (NI) data. The method treats actual NI data as measurements of the local YM of PNC; it further assesses the effect of the nonhomogeneous dispersion of carbon nanotubes in polymers on the statistical variations observed in experimental NI data. First the method simulates numerically NI data by developing a random field and a multiscale homogenization model. Subsequently, the MCFEM applies the spectral representation method to generate a population of samples of local YM values. These local values are then used in conjunction with a stochastic finite element scheme to derive estimates for the YM of PNC. The statistical processing of the ensemble of FE solutions yields overall YM values that agree well with corresponding results reported in the literature.
Power aware placement for FPGAs with dual supply voltages

Usage of multiple supply voltages has raised new design challenges in IC design. We focus on the problem of power aware placement when dual supply voltages provide two high performance and low power working modes on each FPGA tile. To meet timing constrains, all logic elements within a tile need to work in the high performance mode when at least one element within that tile has tight timing requirements. To save more energy, we propose a placement flow that enables more tiles and logic elements to work in the low power mode. We start with an initial placement that provides coarse timing requirements. A heuristic algorithm is proposed to select a subset of tiles to host critical elements. Considering the candidate hosts, a set of movements are generated and those with least cost overheads are accepted. We also introduce ?saving ratio? as a new metric for measuring quality of MSV-based power aware placement algorithms. Our proposed placement flow improves both the static and dynamic power consumption by about 4.5% which translates into an improvement in the saving ratio by 20.25%.
Peer Contagion in Child and Adolescent Social and Emotional Development

In this article, we examine the construct of peer contagion in childhood and adolescence and review studies of child and adolescent development that have identified peer contagion influences. Evidence suggests that children's interactions with peers are tied to increases in aggression in early and middle childhood and amplification of problem behaviors such as drug use, delinquency, and violence in early to late adolescence. Deviancy training is one mechanism that accounts for peer contagion effects on problem behaviors from age 5 through adolescence. In addition, we discuss peer contagion relevant to depression in adolescence, and corumination as an interactive process that may account for these effects. Social network analyses suggest that peer contagion underlies the influence of friendship on obesity, unhealthy body images, and expectations. Literature is reviewed that suggests how peer contagion effects can undermine the goals of public education from elementary school through college and impair the goals of juvenile corrections systems. In particular, programs that "select" adolescents at risk for aggregated preventive interventions are particularly vulnerable to peer contagion effects. It appears that a history of peer rejection is a vulnerability factor for influence by peers, and adult monitoring, supervision, positive parenting, structure, and self-regulation serve as protective factors.
Preparation and Characterization of Y3Al5O12 (YAG) from An Alkoxide-Derived Polymer

The controlled hydrolysis of Al(O- sec -Bu) 3 and Y(O- iso -Pr) 3 or the reaction of Y(OOCCH) 3 with partially hydrolyzed Al(O- sec -Bu) 3 [AlO 0.75 (O- sec -Bu) 1.5 ] resulted in the formation of soluble polymeric materials. Pyrolysis of these materials under a flow of oxygen led to the formation of yttrium aluminum garnet (YAG) at 650-1500°C. YAG was the only crystalline phase observed during pyrolysis, and the Al/Y ratio of the pyrolysis products and the starting material was identical. However, infrared spectroscopy indicated that carbonate groups and entrained CO 2 existed in the products at temperatures up to 1250°C. The pyrolysis chemistry of the precursors and the microstructure of the products were studied by FT-IR, TGA, XRD, SEM and elemental analyses.