cssi/SciSciGPT-SciSciNet huggingface dataset:
Diversity of cell lengths in terminal portions of roots: implications to cell proliferation

Abstract Terminal meristems are responsible for all primary growth of roots. It has been asserted that all cells of root meristems are actively dividing (no cells cycle slowly or arrest in the cycle) and stem cell populations expand exponentially. Because cells do not slide relative to each other in roots, relative cell lengths may be used to determine relative cell cycle durations and/or proportions of cells actively dividing in root tissues. If all cells are cycling, no interphase cells should be longer than critical length (length of longest mitotic cell in the meristem) and cells should exhibit an exponential cell–age distribution. Lengths of all cells were obtained radially across entire median longitudinal root sections at 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mm from the founder cell/root cap boundary for five plant species to estimate percentages of cells longer than critical length. For example, up to 15 and 90% of all interphase cells were longer than critical length in 0.5 and 2.0 mm tissues, respectively, indicating that slow-cycling and/or non-proliferative cells are present in such tissues. In order to determine if the distribution of cell lengths in 0.5 mm segments approximated an exponential cell–age distribution, lengths of interphase cells less than critical length were determined. Such interphase cells were placed into ten groups according to cell length and percentages of cells in each group were compared with percentages of cells in groups calculated from an exponential cell–age distribution. Percentages of cells were significantly different from predicted percentages of between 6 and 9 out of ten groups — cell lengths were not distributed exponentially. Because there are significant numbers of interphase cells longer than critical length and since lengths of interphase cells shorter than critical length do not resemble an exponential cell–age distribution, it must be concluded that not all cells in root segments from 0.5 to 3.0 mm root segments are actively dividing. Heretofore, no databases of cell lengths have been used to test these assertions.
Dynamical mass generation of massless string excitations at zero and finite temperature

Abstract We investigate the genus 1 mass shift of the dilaton, graviton, and antisymmetric tensor (Kalb-Ramond) field in the zero temperature closed bosonic string and the type II superstring at finite temperature. We find diltion and antisymmetric tensor field mass generation at the one-loop level. The dynamically generated masses are proportional to the cosmological constant or the free energy at finite temperature. Contrary to previous assertions, the graviton remains massless.
Endothelial Nitric-oxide Synthase (eNOS) Is Activated through G-protein-coupled Receptor Kinase-interacting Protein 1 (GIT1) Tyrosine Phosphorylation and Src Protein

Nitric oxide (NO) is a critical regulator of vascular tone and plays an especially prominent role in liver by controlling portal blood flow and pressure within liver sinusoids. Synthesis of NO in sinusoidal endothelial cells by endothelial nitric-oxide synthase (eNOS) is regulated in response to activation of endothelial cells by vasoactive signals such as endothelins. The endothelin B (ETB) receptor is a G-protein-coupled receptor, but the mechanisms by which it regulates eNOS activity in sinusoidal endothelial cells are not well understood. In this study, we built on two previous strands of work, the first showing that G-protein βγ subunits mediated activation of phosphatidylinositol 3-kinase and Akt to regulate eNOS and the second showing that eNOS directly bound to the G-protein-coupled receptor kinase-interacting protein 1 (GIT1) scaffold protein, and this association stimulated NO production. Here we investigated the mechanisms by which the GIT1-eNOS complex is formed and regulated. GIT1 was phosphorylated on tyrosine by Src, and Y293F and Y554F mutations reduced GIT1 phosphorylation as well as the ability of GIT1 to bind to and activate eNOS. Akt phosphorylation activated eNOS (at Ser1177), and Akt also regulated the ability of Src to phosphorylate GIT1 as well as GIT1-eNOS association. These pathways were activated by endothelin-1 through the ETB receptor; inhibiting receptor-activated G-protein βγ subunits blocked activation of Akt, GIT1 tyrosine phosphorylation, and ET-1-stimulated GIT1-eNOS association but did not affect Src activation. These data suggest a model in which Src and Akt cooperate to regulate association of eNOS with the GIT1 scaffold to facilitate NO production.
Impact of tritium removal and He-3 recycling on structure damage parameters in a D–D fusion system

Abstract Removing tritium produced by D–D fusion and recycling part of it after it decays to He-3 significantly reduces the fraction of fusion energy carried by neutrons in a D–D system. For a catalyzed D–D system (no tritium removal), the peak dpa rate in candidate structural materials is 25–35% lower than that in an equivalent D–T system with the same fusion power wall loading. The gas production and transmutation rates are about 60% lower. As tritium is removed gas production and transmutations decrease by more than two orders of magnitude and the dpa rate decreases by a factor of 2.3–2.8. An additional reduction of a factor of 1.6–1.7 in damage parameters is achieved by recycling the removed tritium as He-3. This results in significant lifetime enhancement of structural materials. Information from tests in fission reactor spectra would be directly relevant in determining the lifetime of the structural material in this He-3-recycled system.
Reliability of sagittal plane hip, knee, and ankle joint angles from a single frame of video data using the GAITRite camera system.

AbstractThe purpose of this study was to establish intra-rater, intra-session, and inter-rater, reliability of sagittal plane hip, knee, and ankle angles with and without reflective markers using the GAITRite walkway and single video camera between student physical therapists and an experienced physical therapist. This study included thirty-two healthy participants age 20–59, stratified by age and gender. Participants performed three successful walks with and without markers applied to anatomical landmarks. GAITRite software was used to digitize sagittal hip, knee, and ankle angles at two phases of gait: (1) initial contact; and (2) mid-stance. Intra-rater reliability was more consistent for the experienced physical therapist, regardless of joint or phase of gait. Intra-session reliability was variable, the experienced physical therapist showed moderate to high reliability (intra-class correlation coefficient (ICC) = 0.50–0.89) and the student physical therapist showed very poor to high reliability (ICC =...
Allosteric Regulation of the N-Methyl-d-Aspartate Receptor-Linked Ion Channel Complex and Effects of Ethanol in Ethanol-Withdrawal Seizure-Prone and -Resistant Mice

The effects of ethanol, glycine, and spermidine on the specific binding of [3H]MK-801 were characterized in Triton-treated membranes prepared from the hippocampus and cortex of ethanol-withdrawal seizure-prone (WSP) and -resistant (WSR) mice. Glycine, an allosteric agonist at the NMDA receptor-linked ion channel complex, caused an increase in specific [3H]MK-801 binding to hippocampal membrane preparations. There were no significant differences in EC50 values between the selected lines for the effect of glycine (WSP, 391.7 +/- 48.4 nM; WSR, 313.4 +/- 77 nM) in the presence of 10 microM NMDA or in the maximal response to the agonist (WSP, 1.75 +/- 0.26 pmol/mg of protein; WSR, 1.67 +/- 0.22 pmol/mg of protein). The EC50 values for the spermidine-induced increase in [3H]MK-801 binding in membranes from hippocampus in the absence (WSP, 11.7 +/- 0.83 microM; WSR, 9.98 +/- 1.29 microM) or in the presence of 10 microM glycine and 10 microM NMDA (WSP, 2.1 +/- 0.35 microM; WSR, 2.37 +/- 0.42 microM) also did not differ. Similar results were obtained in cortical membranes. Saturation isotherms indicated that there was no difference in the density of [3H]MK-801 binding sites, or in their affinity for the radioligand, between the mouse lines. In addition, administration of ethanol by inhalation (24 h) to WSP and WSR mice did not cause an increase in the density of [3H]MK-801 binding sites, and there was no difference in the density or affinity of binding sites between the mouse lines.(ABSTRACT TRUNCATED AT 250 WORDS)
Validation of gene regulatory network inference based on controllability

There are two distinct issues regarding network validation: (1) Does an inferred network provide good predictions relative to experimental data? (2) Does a network inference algorithm applied within a certain network model framework yield networks that are accurate relative to some criterion of goodness? The first issue concerns scientific validation and the second concerns algorithm validation. In this paper we consider inferential validation relative to controllability; that is, if an inference procedure is applied to synthetic data generated from a gene regulatory network and an intervention procedure is designed on the inferred network, how well does it perform on the true network? The reasoning behind such a criterion is that, if our purpose is to use gene regulatory networks to design therapeutic intervention strategies, then we are not concerned with network fidelity, per se, but only with our ability to design effective interventions based on the inferred network. We will consider the problem from the perspectives of stationary control, which involves designing a control policy to be applied over time based on the current state of the network, with the decision procedure itself being time independent. {The objective of a control policy is to optimally reduce the total steady-state probability mass of the undesirable states (phenotypes), which is equivalent to optimally increasing the total steady-state mass of the desirable states. Based on this criterion we compare several proposed network inference procedures. We will see that inference procedure \psi may perform poorer than inference procedure \xi relative to inferring the full network structure but perform better than \xi relative to controllability. Hence, when one is aiming at a specific application, it may be wise to use an objective-based measure of inference validity.
An analysis of foreign takeovers in the United States

Using a sample of 96 US companies taken over by foreign companies during the period 1975-87, we assess foreign takeovers in two stages: pre-takeover and takeover. We find evidence that foreign firms target US firms whose operations are related to their own operations and that have low market-to-book ratios, suggesting foreign bidders acquire firms that provide a greater opportunity for market entry and synergistic gains. The synergistic gains appear to result from the foreign buyer using its own intangible assets (e.g. managerial skills) to improve the target. We also find that foreign takeover activity is aimed primarily at US industries that themselves make high levels of foreign direct investments, implying that the bidders use takeovers as a quick way to counteract rival firms' moves. We find evidence that foreign takeovers take place in relatively mature, low-growth industries and that foreign targets are, on average, smaller than the non-targets. The wealth effect on the announcement of a takeover is significantly higher for foreign takeovers than for takeovers by domestic firms. Also, we find that foreign bidders pay a slightly higher premium for targets whose operations are related to their own.
Numerical study of the effect of polyurea on the performance of steel plates under blast loads

Abstract We present the results of our numerical simulation of the dynamic response and deformation of 1 m diameter circular DH-36 steel plates and DH-36 steel-polyurea bilayers, subjected to blast-like loads. Different thicknesses of the polyurea are considered and the effect of polyurea thickness on the performance of steel plates under blast loads is investigated. For each polyurea thickness, we have simulated three cases: (1) polyurea cast on the front face (loading face); (2) polyurea (of the same thickness) cast on the back face; and (3) steel plate of a suitable thickness such that the areal density remains the same in all three cases. Two types of loading are applied to the polyurea-steel system: (1) direct application of pressure on the bilayer system, (2) application of pressure through a separate medium (soft polyurethane or water). The resulting differences are demonstrated and discussed throughout the paper. For the constitutive properties, we have used physics-based and experimentally-supported temperature- and rate-sensitive models for DH-36 steel and polyurea, including, in the latter case, the pressure effects. Results from the simulations reveal that, when the polyurea layer with enough thickness is cast on the back face of the plate, the bilayer demonstrates superior performance relative to the other two cases. The differences become more pronounced as the polyurea thickness (maintaining the same areal density in the three cases) becomes greater.
Adrenal androgen concentrations increase during infancy in male rhesus macaques (Macaca mulatta)

This study investigated adrenal androgens (AA), gonadotropins, and cortisol in castrated and gonad-intact male rhesus macaques from birth through infancy. Blood samples were collected longitudinall...
Selective transcription of p53 target genes by zinc finger-p53 DNA binding domain chimeras.

Abstract Active p53 stimulates the transcription of a number of key genes, including the pro-apoptotic gene bax , as well as p21 , a cell cycle regulator. In this study we constructed novel chimeric zinc finger–p53 DNA binding domain (DBD) transcription factors designed to bind to the promoters of specific p53 regulated genes. In order to selectively increase the expression of Bax , we coupled a pre-selected three-zinc finger (Zif) peptide targeted to a sequence in the bax promoter to a minimal p53 DBD. This chimeric protein could increase reporter gene transcription from a minimal bax promoter (up to 10-fold) but not from a minimal p21 promoter in p53-deficient Saos-2 cells. However, fusion proteins carrying longer p53 DBDs displayed entirely different selectivity and potency. Thus, Zif–p53 DBD chimeras containing N- and C-terminal extensions of the minimal DBD could increase transcription driven by a minimal p21 promoter up to 800-fold. These chimeras preferred the minimal p21 promoter up to 500-fold over the minimal bax promoter. Additionally, endogenous p21 message and protein levels were increased in cells expressing the p21 selective Zif–p53 DBD chimera and expression of the chimeric proteins resulted in partial cell cycle arrest. Cell fractionation experiments indicated that the Zifs enhanced nuclear localization of the Zif–p53 DBD chimera. These studies suggest that it is possible to create chimeric transcription factors able to strongly and selectively activate genes downstream of p53.
Oscillatory velocity response of premixed flat flames stabilized in axial acoustic fields

Abstract This article describes a combined theoretical-experimental investigation of the processes that drive axial instabilities in solid propellant rocket motors. In this study, the solid propellant flame has been simulated by a premixed flat flame that has been stabilized on the porous side-wall of a duct. The driving processes have been investigated by studying the interaction of the premixed flame with an axial acoustic field. Using experimentally determined acoustic pressures, burner surface admittances, and steady-state flame temperature distributions as input data, the developed model was used to determine the characteristics of the velocity field in the flame region under a variety of test conditions. The predicted velocity field was then compared with LDV velocity measurements to check the validity of the model and determine the flame driving. These studies reveal that the investigated flame responds to the presence of an axial acoustic field by producing an oscillatory velocity component, ν′, normal to the duct wall, that can drive or damp the acoustic field. Comparison of the measured data with the model predictions reveal satisfactory agreement. These studies also showed that driving and damping of the acoustic field occur simultaneously in different regions of the flame. The net effect of the flame upon the acoustic field depends upon the relative magnitudes of these opposing tendencies. It is also shown that the flame driving depends upon the acoustic admittance of the side-wall surface and the frequency of the acoustic field.
Anisotropic, Polarizable Molecular Mechanics Studies of Inter- and Intramolecular Interactions and Ligand–Macromolecule Complexes. A Bottom-Up Strategy

We present an overview of the SIBFA polarizable molecular mechanics procedure, which is formulated and calibrated on the basis of quantum chemistry (QC). It embodies nonclassical effects such as electrostatic penetration, exchange-polarization, and charge transfer. We address the issues of anisotropy, nonadditivity, and transferability by performing parallel QC computations on multimolecular complexes. These encompass multiply H-bonded complexes and polycoordinated complexes of divalent cations. Recent applications to the docking of inhibitors to Zn-metalloproteins are presented next, namely metallo-β-lactamase, phosphomannoisomerase, and the nucleocapsid of the HIV-1 retrovirus. Finally, toward third-generation intermolecular potentials based on density fitting, we present the development of a novel methodology, the Gaussian electrostatic model (GEM), which relies on ab initio-derived fragment electron densities to compute the components of the total interaction energy. As GEM offers the possibility of a...
Past success and convergent thinking in groups: The role of group-focused attributions

Past success often causes groups to think narrowly around strategies that have worked in the past, even when environmental change has rendered these strategies ineffective. From a psychological perspective, this research seems to indicate that past success may give rise to convergent thinking in groups. Why might successful groups be prone to convergent thinking? I argue that the relationship between past success and convergent thinking may depend on the attributions that groups generate to explain their shared success. In this paper, I focus on two distinct attributions at the group level: Individual-focused attributions that reflect the idiosyncratic characteristics of individual group members and group-focused attributions that reflect the emergent properties of the group as a whole. I found that group-focused attributions for past success cause groups to generate fewer ideas that are, on average, more convergent. In contrast, individual-focused attributions cause groups to generate more ideas that are on average more divergent. These findings suggest that the experience of success may actually stimulate divergent thinking depending on how a group chooses to explain it. Copyright © 2004 John Wiley & Sons, Ltd.
Appendicitis in childhood

Ultrasonography, CT scanning, and prolonged observation may improve diagnostic accuracy of appendicitis in children with atypical presentations. This article describes diagnostic pitfalls, including early presentation and abnormal appendiceal location.
Climate change adaptation advantage for African road infrastructure

The African continent is facing the potential of a $183.6 billion USD liability to repair and maintain roads damaged from temperature and precipitation changes directly related to predicted climate change through 2100. This cost is strictly to retain the current road inventory. This cost does not include costs associated with impacts to critically needed new roads. In many African countries, limited or non-existent funds for adaptation and mitigation are challenging these countries to identify the threats that are posed by climate change, develop adaptation approaches to the predicted changes, incorporate changes into mid-range and long-term development plans, and secure funding for the proposed and necessary adaptations. Existing studies have attempted to quantify the impact of climate change on infrastructure assets that will be affected by climate change in the coming decades. The current study extends these efforts by specifically addressing the effect of climate change on the African road infrastructure. The study identifies both total costs and opportunity costs of repairing and maintaining infrastructure due to increased stressors from climate change. Proactive and reactive costs are examined for six climate scenarios, with costs ranging, respectively, from an average of $22 million USD to $54 million USD annually per country. A regional analysis shows contrast between impacts in five areas of the continent, with impacts ranging from 22 % opportunity cost to 168 %. These costs have the potential to delay critical infrastructure development on the continent and present a challenge to policy makers balancing short-term needs with long-term planning.
Membrane actions of 1α,25(OH)2D3 are mediated by Ca2+/calmodulin-dependent protein kinase II in bone and cartilage cells

1α,25(OH)2D3 regulates osteoblasts and chondrocytes via its membrane-associated receptor, protein disulfide isomerase A3 (Pdia3) in caveolae. 1α,25(OH)2D3 binding to Pdia3 leads to phospholipase-A2 (PLA2)-activating protein (PLAA) activation, stimulating cytosolic PLA2 and resulting in prostaglandin E2 (PGE2) release and PKCα activation, subsequently stimulating differentiation. However, how PLAA transmits the signal to cPLA2 is unknown. Ca(2+)/calmodulin (CaM)-dependent protein kinase II (CaMKII) activation is required for PLA2 activation in vascular smooth muscle cells, suggesting a similar role in 1α,25(OH)2D3-dependent signaling. The aim of the present study is to evaluate the roles of CaM and CaMKII as mediators of 1α,25(OH)2D3-stimulated PLAA-dependent activation of cPLA2 and PKCα, and downstream biological effects. The results indicated that 1α,25(OH)2D3 and PLAA-peptide increased CaMKII activity within 9 min. Silencing Cav-1, Pdia3 or Plaa in osteoblasts suppressed this effect. Similarly, antibodies against Plaa or Pdia3 blocked 1α,25(OH)2D3-dependent CaMKII. Caveolae disruption abolished activation of CaMKII by 1α,25(OH)2D3 or PLAA. CaMKII-specific and CaM-specific inhibitors reduced cPLA2 and PKC activities, PGE2 release and osteoblast maturation markers in response to 1α,25(OH)2D3. Camk2a-silenced but not Camk2b-silenced osteoblasts showed comparable effects. Immunoprecipitation showed increased interaction of CaM and PLAA in response to 1α,25(OH)2D3. The results indicate that membrane actions of 1α,25(OH)2D3 via Pdia3 triggered the interaction between PLAA and CaM, leading to dissociation of CaM from caveolae, activation of CaMKII, and downstream PLA2 activation, and suggest that CaMKII plays a major role in membrane-mediated actions of 1α,25(OH)2D3.
Sample Loss during Measurement of Airborne Antineoplastic Agents

Handling, preparation and administration of antineoplastic drugs are suspected health hazards for hospital and clinic personnel. Measurement of personal and area exposures to such materials in air is difficult because the average concentration is often close to the analytical detection limit. For this reason, and because of the random nature of drug spills and releases, the sampling method of choice typically extends over a 40-hour workweek. In this study a method for monitoring two airborne antineoplastic drugs, fluorouracil and methotrexate, was tested for possible loss of the drug from filters during air sampling. Glass-fiber filters (37 mm) were spiked with known amounts of drug and subjected to the same airflow conditions as are used in workplace sampling. Filter extracts were analyzed using high performance liquid chromatography (HPLC). Losses during storage up to a month were less than 5% for both drugs. Losses during airflow were directly proportional to cumulative air volume, 2% of the amount on ...
Deleterious effects on Drosophila development associated with the sigma virus infection

Abstract A strain of Drosophila melanogaster in which the flies were infected with the heritable virus that causes CO 2 sensitivity (sigma virus) was investigated in order to determine whether the flies suffered deleterious effects due to the infection. Eggs laid by virus-infected and virus-free females were counted and the resultant numbers of adult progeny were scored. It was found that deaths did occur among developing virus-infected progeny and that the deaths were in direct proportion to the logarithm of the number of infectious units inherited by the progeny. The fraction of surviving progeny was lowered from a value of 0.89 for the virus-free control line to 0.69 for the infected flies. The virus-infected flies that escaped death during development required 5–10 hours more than the noninfected control flies to develop from egg to adult.
Beta-amyloid(1-40) effects on behavior and memory.

Abstract Beta amyloid 1–40 is a primary protein in plaques found in the brains of patients with Alzheimer's disease. There is evidence that unaggregated soluble β-amyloid may be neurotoxic and may have behavioral effects on some types of memory. In the current study, the 1–40 fragment of β-amyloid protein (βA4), or vehicle, was bilaterally injected into the rostral hippocampus of rats performing under stable food-maintained schedules of reinforcement or under a delayed conditional discrimination procedure. Under the first procedure, rats were trained to stability under a multiple fixed interval 15 s, fixed ratio 30 reinforcement schedule. This reinforcement schedule has proven sensitive to low-dose drug effects. Acute bilateral hippocampal βA4 (1.0, 2.0 and 3.0 μl of 10−3 M) administration did not significantly alter responding, compared to vehicle, under either reinforcement condition. Following the acute single-injection regimen, rats were administered chronic daily βA4 (1μl of 10−3 M), bilaterally, for 15 days. No significant changes in lever-pressing performance were observed during the chronic injection regimen, but performance declined significantly 30 days after termination of the chronic daily regimen. Histological examination revealed three of six rats showed showed positive reactions under Thioflavin S staining in and around the area of cannulae termination. The second assessment employed a delayed conditional discrimination procedure to evaluate the effects of intrahippocampal injections of βA4 on short-term working memory. This conditional discrimination procedure assesses appropriate responding, dependent on a previously presented stimulus, after delays of various lengths have been imposed between the stimulus and the response opportunity. Delay values ranged from 0.01 s to 20 s. Under this procedure, accuracy was unaffected across all delay values following single bilateral intrahippocampal injections of βA4 (1.0, 2.0 and 3.0 μl of 10−3 M). Thus, the soluble unaggregated form of βA4, injected into the dorsal hippocampus, does not appear to have behavioral effects on performance or short-term working memory in rats, but multiple repeat injections produced performance decrements several weeks later. Repeated injection of βA4 through indwelling cannulae shows promise for development of an animal model of Alzheimer's disease.
Adrenal ascorbic acid levels during pregnancy and lactation in rats and mice.

Adrenal ascorbate was determined in rats and mice at various stages of pregnancy and lactation. In rats the ascorbate was reduced throughout pregnancy and during the first 4 days of lactation, after which the level of the vitamin returned to normal. In mice a rise in adrenal ascorbate was evidenced on the 12th day of pregnancy and on the 1st day of lactation, whereas a significant reduction occurred on the 2nd day of lactation. After the 5th day of lactation the adrenal ascorbate returned to a normal level. These data are interpreted to mean that adrenal ascorbate reflects increased adrenocortical activity immediately after parturition and at the initiation of lactation. The authors are of the opinion that the return of adrenal ascorbate to a normal level by the 6th day of lactation does not necessarily mean that adrenocortical function has returned to the level of nonpregnant, nonlactating animals.
Unsupervised Lexicon Acquisition from Speech and Text

When introducing a large vocabulary continuous speech recognition (LVCSR) system into a specific domain, it is preferable to add the necessary domain-specific words and their correct pronunciations selectively to the lexicon, especially in the areas where the LVCSR system should be updated frequently by adding new words. In this paper, we propose an unsupervised method of word acquisition in Japanese, where no spaces exist between words. In our method, by taking advantage of the speech of the target domain, we selected the domain-specific words among an enormous number of word candidates extracted from the raw corpora. The experiments showed that the acquired lexicon was of good quality and that it contributed to the performance of the LVCSR system for the target domain.
The quest for magnets composed of vanadium and 1,4-benzoquinones

Abstract The reaction of Vo(CO)6 and representative quinones, A (A = benzoquinone, chloranil, 2,3-dicyano-1,4-naphthoquinone, and dihydroxy-1,4-benzoquinone), form materials of V(A)2 · zCH2Cl2 (z
CHANGES OVER TIME IN ACADEMIC DISHONESTY AT THE COLLEGIATE LEVEL

Recent assertions that collegiate cheating has risen dramatically have increased in frequency. We examine the possibility that these assertions are based on comparisons of studies of different behaviors with varied methodologies, and different opportunities to cheat. To assess the increase in cheating we identified a cheating behavior which had been empirically studied consistently from the early 1900s. When the percentages of students who cheated in these studies were compared across time periods, while controlling for methodological differences, no significant linear trend was found.
Age-dependent changes in gastrointestinal transport and retention of particulate manganese oxide in the rat

Translocation of inhaled particulates from the nasopharynx and upper tracheobronchial area to the gastrointestinal tract is a major route of exposure for particles with a mass median diameter of greater than 1 μm. Previous studies in this laboratory with particulate Mn 3 O 4 have shown that preweanling rats have substantially higher tissue Mn concentrations than similarly treated adults, indicating possible differences in uptake or elimination or both. This study was conducted to evaluate changes in gastrointestinal movement and retention of particulate Mn}O 4 in the preweanling and weaned rat. 85 Sr‐labeled microspheres were used to evaluate gastrointestinal transit rate (TR), while particulate Mn 3 O 4 was used to evaluate particulate retention at selected ages. The results show that stomach retention time in the preweanling is at least twice that of the postweanling (90 min versus 42 min). In general, intestinal TR was not different in any of the ages evaluated, while transit time increased as intestin...
Association of venous thromboembolism with human immunodeficiency virus and mortality in veterans.

hydrogenase concentrations in pleural fluid (12). Measurement of the serum pleural fluid gradients for protein or albumin has been advocated to overcome this problem, although when used alone it may overdiagnose transudates (13). In short, neither alternative criteria (2,3,14,15) nor clinical judgment (16) are superior to standard criteria for separating pleural transudates from exudates. Our results support the feasibility of using pleural proBNP as part of the diagnostic approach in patients with suspected heart failure. The test may be especially useful in patients with exudates who have been treated with diuretics, or when trying to distinguish hepatic and cardiac causes of transudates.
Woody Plant Encroachment by Juniperus virginiana in a Mesic Native Grassland Promotes Rapid Carbon and Nitrogen Accrual

The cover and abundance of Juniperus virginiana L. in the U.S. Central Plains are rapidly increasing, largely as a result of changing land-use practices that alter fire regimes in native grassland communities. Little is known about how conversion of native grasslands to Juniperus-dominated forests alters soil nutrient availability and ecosystem storage of carbon (C) and nitrogen (N), although such land-cover changes have important implications for local ecosystem dynamics, as well as regional C and N budgets. Four replicate native grasslands and adjacent areas of recent J. virginiana encroachment were selected to assess potential changes in soil N availability, leaf-level photosynthesis, and major ecosystem C and N pools. Net N mineralization rates were assessed in situ over two years, and changes in labile soil organic pools (potential C and N mineralization rates and microbial biomass C and N) were determined. Photosynthetic nitrogen use efficiencies (PNUE) were used to examine differences in instantaneous leaf-level N use in C uptake. Comparisons of ecosystem C and N stocks revealed significant C and N accrual in both plant biomass and soils in these newly established forests, without changes in labile soil N pools. There were few differences in monthly in situ net N mineralization rates, although cumulative annual net N mineralization was greater in forest soils compared to grasslands. Conversely, potential C mineralization was significantly reduced in forest soils. Encroachment by J. virginiana into grasslands results in rapid accretion of ecosystem C and N in plant and soil pools with little apparent change in N availability. Widespread increases in the cover of woody plants, like J. virginiana, in areas formerly dominated by graminoid species suggest an increasing role of expanding woodlands and forests as regional C sinks in the central U.S.
Production planning to support mixed-model assembly

A mixed-model assembly line is widely used nowadays in industry. Effectively applying mixed-model assembly can result in smooth part usage and balanced workloads on the assembly line. The problem of production planning in terms of scheduling various models on an assembly line over a time horizon is studied here. The problem assumes that each model has a given range of production days within the planning horizon. An industrial production system is presented to demonstrate the application of this problem. A two-phase procedure that generates an initial solution and makes further improvement is developed. The procedure is evaluated using randomly generated problems and an industrial example.
Moiré Screens Coded with Pseudo-Random Sequences

A new type of moire grating that can produce very narrow moire beat lines is presented. Each grating period contains a number of transparent or opaque lines of equal width. The sequence of transmission coefficients across the grating period is not periodic but is chosen to be a binary pseudo-random sequence. These sequences are commonly used in signal processing because of their sharply peaked autocorrelations. When used to encode a moire grating, they produce very narrow moire beat lines. Three experimental gratings are discussed, and a contouring measurement using the narrow beat lines is described.
A Photoelectrochemical Model of Proton Exchange Water Electrolysis for Hydrogen Production

A photoelectrochemical model for hydrogen production from water electrolysis using proton exchange membrane is proposed based on Butler-Volmer kinetics for electrodes and transport resistance in the polymer electrolyte. An equivalent electrical circuit analogy is proposed for the sequential kinetic and transport resistances. The model provides a relation between the applied terminal voltage of electrolysis cell and the current density in terms of Nernst potential, exchange current densities, and conductivity of polymer electrolyte. Effects of temperature on the voltage, power supply, and hydrogen production are examined with the developed model. Increasing temperature will reduce the required power supply and increase the hydrogen production. An increase of about 11% is achieved by varying the temperature from 30°C to 80°C. The required power supply decreases as the illumination intensity becomes greater. The power supply due to the cathode overpotential does not change too much with the illumination intensity. Effects of the illumination intensity can be observed as the current density is relatively small for the examined illumination intensities.
Perceptions of School and Aspirations of Rural Students with Learning Disabilities and Their Nondisabled Peers

This study examined the school perceptions and educational aspirations of 6,599 rural high school students, a sample that included 428 students with learning disabilities (LD). Regardless of disability status, rural high school students who had negative perceptions of school had less well-defined postsecondary educational plans and less often aspired to complete college or pursue an advanced degree. Compared to nondisabled youth, rural students with LD were more likely to have negative perceptions of school and lower postsecondary aspirations. However, students with LD who had positive perceptions of school more often planned to pursue postsecondary education and aspired to complete college or an advanced degree. Implications for research and interventions pertaining to the educational attainment of students with LD are discussed.
Violating the Monotonicity condition for instrumental variable—Dimorphic patterns of gene–behavior association

I document the dimorphic patterns for the association between DAT1 9R9R genotype and measures of risky behaviors including drinking, use of marijuana, cocaine, other drugs, and number of sexual partners. The associations between DAT1 9R9R genotype and risky behaviors are often in opposite signs for females and males, in the National Longitudinal Survey of Adolescent Health (Add Health). This article sensitizes the researcher on the sexual dimorphic pattern of gene–behavior association, and its risk to violate the Monotonicity (no-defiers) condition in applications that use genetic markers as instrumental variables.
Changes in the cellular content of ribonucleic acid, deoxyribonucleic acid and protein in cultured cells during logarithmic growth.

Abstract Determinations of the cellular content of ribonucleic acid (RNA), deoxyribonucleic acid (DNA), and protein in cultured cells during logarithmic growth indicate that these constituents approximately double in quantity in the lag phase. DNA accumulates most rapidly, and the maximum level remains essentially constant for several hours before cell division, suggesting synthesis during mitotic interphase.
Promoting synergistic research and education in computational biology and drug design

Supported by US National Science Foundation (NSF) and the International Society of Intelligent Biological Medicine (ISIBM), the IEEE 7th International Conference on Bioinformatics and Bioengineering at Harvard Medical School was designed dynamically in response to the cutting edge synergistic research and education. One of the key components of this academic event is the poster presentation focusing on specific topics to foster collaboration between the computational biology and drug design domains. The Harvard meeting attracted over five hundred scientists, researchers and medical doctors world-wide to present, discuss and exchange their research. The synergies between computational biology and drug design research had been well observed by participants. The poster sessions had been designed to be responsive to the need for synergistic inter/multidisciplinary research and education. A panel of judges was formed to decide the best posters. The papers in this special issue were selected for runners-up of the best poster award by a panel of judges. Authors were then invited to expand their posters into full research papers. Submitted papers were required to contain significant additional scientific detail and were rigorously reviewed by at least three external reviewers. Detailed information regarding the academic event can be found at the White Paper of the IEEE 7th International Conference on Bioinformatics and Bioengineering at Harvard Medical School at BMC Genomics http://www.biomedcentral.com/1471-2164/9/S2/I1.
When traditionally inseparable services are separated by technology: the case of patient portal features offered by primary care providers

Health-care services have traditionally been provided and consumed simultaneously, as exemplified by in-person patient visits to primary care providers (PCPs), where clinical assessment and treatment are provided and consumed face-to-face. Technological intermediation is changing this traditional assumption, however, as patient-centric technologies, such as patient portals, are creating service separation opportunities. While service separation facilitated by patient portals may bring welcome changes to access, efficiency, and clinical outcomes, usage of patient portals by health-care consumers remains low. Suboptimal demand-side usage of patient portals, especially at the primary care level, could have significant negative implications for patient-centered policy initiatives predicated on patient empowerment and engagement. This paper contributes to this important policy context by reporting findings from a study designed to assess patient perceptions associated with hypothetical patient portal features offered by PCPs and potential subsequent impacts to PCP loyalty and switching propensity. We find that patient portal features focused on back-office (clinical) self-service capabilities (such viewing health records or summaries from prior visits) are perceived positively by consumers, but, interestingly, clinical digital communication and collaboration features (such as online video consultations with physicians) do not have significant perception impacts. These findings suggest that patient portals may act as a complement to health-care service delivery, while substitution for clinical in-person interactions may not be viewed positively.
A single up-stream element confers responsiveness to 1,25-dihydroxyvitamin D3 and tumor necrosis factor-alpha in the rat osteocalcin gene

Tumor necrosis factor-alpha (TNF alpha) is one of several autocrine/paracrine factors known to exert potent inhibitory effects on bone. We have shown that TNF alpha inhibition of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]-stimulated synthesis of the bone-specific protein osteocalcin (OC) occurs by decreasing steady state levels of OC mRNA, suggesting a pretranslational mechanism. In many genes, TNF alpha action is mediated by the transcription factor NF kappa B. Analysis of OC 5'-flanking DNA revealed a sequence structurally homologous to the previously described NF kappa B-binding site and, thus, a potential TNF alpha response element. Deletion analysis was performed to identify the sequences mediating the response to TNF alpha in osteoblastic ROS 17/2.8 cells by transient transfection with reporter constructs containing rat OC 5'-flanking DNA [chloramphenicol acetyltransferase (CAT)] that retained or deleted homologous NF kappa B sites or a previously defined 1,25-(OH)2D3 response element (VDRE). Transfect...
Finite temperature phase structures of lattice QCD for 8 and 17 flavors

Abstract Recent results obtained on the Columbia 64-node parallel supercomputer are reported. The influence of many dynamical quark flavors on the finite temperature phase transition structure of lattice quantum chromodynamics (QCD) is investigated. For the chosen numbers of flavors, N f = 8 and 17, the phase structure is mapped out in the range of quark mass 0.1 ≤ m q a ≤ 10 on a 16 3 × 4 lattice with zero baryon density. In contrast to an earlier study, our results suggest that the chiral and deconfinement phase transitions correspond to separate domains on the ( m q , N f ) plane. For the two values of flavors studied, there is no qualitative difference in the phase structure. Although the chiral transition becomes stronger with increasing N f , the phase structure is similar to that of N f = 4 case.
Frequency analysis of human jaw tremor at rest

Abstract It is not known whether rest position is controlled actively by a low degree of muscular activity or passively by muscular and tissue visco-elasticity. The frequency analysis of the jaw tremor at rest was studied to determine if it could be useful for the study of rest position. Jaw tremor was recorded in three different head positions of normal subjects by two accelerometers fixed to the upper and lower premolars. The acceleration signals were low-pass filtered, digitized and analysed by computer. A Fast Fourier Transform algorithm was used to determine spectral density. Electromyograms of the right and left anterior temporal and masseter muscles and an electrocardiogram were recorded with surface electrodes, and the data correlated with jaw tremor. The lower jaw oscillated at the same frequency as the head, and the tremor was a low-frequency narrow-band process. Head deflection produced changes in the power spectral density of the tremor. A time correlation between the shape of the acceleration raw data and the heart beat was present in every subject. However, frequency content and power spectral density of the jaw tremor at rest may be determined also by the degree of muscular activity.
Database of all THz signatures measured on solids and liquids in the range 100 GHz to 10 THz

A catalog of resonant absorption signatures measured on solids and liquids, by transmission and reflection, in the range of 100 GHz to 10 THz, has become a necessity for researchers in the THz field. In this work a THz database has been complied with 205 signatures of various chemical and biological materials. The database includes all published characteristic of the materials such as sample preparation, signature center frequency, signature frequency width, absorbance and attenuation coefficient at frequency center, complex refractive index (where provided), and the measurement techniques used. This is the first database of its kind and has the largest collection of THz signatures that has ever been recorded. All the signatures reported are experimental, and is conveniently accessed using a GUI-based search engine running in MATLAB.