cssi/SciSciGPT-SciSciNet huggingface dataset:
Perspectives of US private payers on insurance coverage for pediatric and prenatal exome sequencing: Results of a study from the Program in Prenatal and Pediatric Genomic Sequencing (P3EGS).

Exome sequencing (ES) has the potential to improve management of congenital anomalies and neurodevelopmental disorders in fetuses, infants, and children. US payers are key stakeholders in patient access to ES. We examined how payers view insurance coverage and clinical utility of pediatric and prenatal ES. We employed the framework approach of qualitative research to conduct this study. The study cohort represented 14 payers collectively covering 170,000,000 enrollees. Seventy-one percent of payers covered pediatric ES despite perceived insufficient evidence because they saw merit in available interventions or in ending the diagnostic odyssey. None covered prenatal ES, because they saw no merit. For pediatric ES, 50% agreed with expanded aspects of clinical utility (e.g., information utility), and 21% considered them sufficient for coverage. For prenatal ES, payers saw little utility until in utero interventions become available. The perceived merit of ES is becoming a factor in payers’ coverage for serious diseases with available interventions, even when evidence is perceived insufficient. Payers’ views on ES’s clinical utility are expanding to include informational utility, aligning with the views of patients and other stakeholders. Our findings inform clinical research, patient advocacy, and policy-making, allowing them to be more relevant to payers.
Carnosine Phosphate as Phosphate Donor in Muscular Contraction

CARNOSINE phosphate was first synthesized by Severin, Georgievskaya and Ivanov1 by a method very similar in detail to that for creatine phosphate2. They showed that this method yields as a rule a diphosphate, both phosphate bonds being high-energy; but that the one which is not on the imidazole ring is more labile. In the presence of muscle extract the latter is transferred to adenosine diphosphate.
Approximate dynamic programming for the military inventory routing problem

The United States Army can benefit from effectively utilizing cargo unmanned aerial vehicles (CUAVs) to perform resupply operations in combat environments to reduce the use of manned (ground and aerial) resupply that incurs risk to personnel. We formulate a Markov decision process (MDP) model of an inventory routing problem (IRP) with vehicle loss and direct delivery, which we label the military IRP (MILIRP). The objective of the MILIRP is to determine CUAV dispatching and routing policies for the resupply of geographically dispersed units operating in an austere, combat environment. The large size of the problem instance motivating this research renders dynamic programming algorithms inappropriate, so we utilize approximate dynamic programming (ADP) methods to attain improved policies (relative to a benchmark policy) via an approximate policy iteration algorithmic strategy utilizing least squares temporal differencing for policy evaluation. We examine a representative problem instance motivated by resupply operations experienced by the United States Army in Afghanistan both to demonstrate the applicability of our MDP model and to examine the efficacy of our proposed ADP solution methodology. A designed computational experiment enables the examination of selected problem features and algorithmic features vis-a-vis the quality of solutions attained by our ADP policies. Results indicate that a 4-crew, 8-CUAV unit is able to resupply 57% of the demand from an 800-person organization over a 3-month time horizon when using the ADP policy, a notable improvement over the 18% attained using a benchmark policy. Such results inform the development of procedures governing the design, development, and utilization of CUAV assets for the resupply of dispersed ground combat forces.
Influence of light on the infection of Aureococcus anophagefferens CCMP 1984 by a "giant virus".

The pelagophyte Aureococcus anophagefferens has caused recurrent brown tide blooms along the northeast coast of the United States since the mid-1980’s, and more recently spread to other regions of the globe. These blooms, due to the high cell densities, are associated with severe light attenuation that destroys the sea grass beds which provide the basis for many fisheries. Data collected by transmission electron microscopy, PCR, and metatranscriptomic studies of the blooms, support the hypothesis that large dsDNA viruses play a role in bloom dynamics. While a large (~140 nm) icosahedral virus, with a 371 kbp genome, was first isolated more than a decade ago, the constraints imposed by environmental parameters on bloom infection dynamics by Aureococcus anophagefferens Virus, (AaV) remain unknown. To investigate the role light plays in infection by this virus, we acclimated A. anophagefferens to light intensities of 30 (low), 60 (medium) or 90 μmol photons m-2 s-1 (high) and infected cultures at these irradiance levels. Moreover, we completed light shift experiments where acclimated cultures were exposed to even lower light intensities (0, 5, and 15 μmol photons m-2 s-1) consistent with irradiance found during the peak of the bloom when cell concentrations are highest. The abundance of viruses produced per lytic event (burst size) was lower in the low irradiance acclimated cultures compared to the medium and high acclimated cultures. Transferring infected cultures to more-limiting light availabilities further decreased burst size and increased the length of time it took for cultures to lyse, regardless of acclimation irradiance level. A hypothetical mechanism for the reduced efficiency of the infection cycle in low light due to ribosome biogenesis was predicted from pre-existing transcriptomes. Overall, these studies provide a framework for understanding light effects on infection dynamics over the course of the summer months when A. anophagefferens blooms occur.
Variability in 210Pb and 210Po partition coefficients (Kd) along the US GEOTRACES Arctic transect

Abstract The naturally occurring 210Po (t1/2 = 138.3d) and 210Pb (t1/2 = 22.3 y) radionuclide pair has been extensively used to study particle scavenging, cycling and transport in the ocean. However, the role of particle composition in the scavenging, sorption and fractionation of 210Po 210 Pb needs to be better understood to successfully utilize these radionuclides as oceanographic tracers. Here, we measure dissolved and particulate 210Pb and 210 Po activities for both small (1-51 μm) and large particles (> 51 μm) with abundance of major phases of suspended particulate matter (SPM) from the US GEOTRACES Arctic transect to examine the role of the concentration and composition of SPM in scavenging and fractionation of these radionuclides along the coastal, Canada Basin and interior stations. 210Po 210 Pb disequilibria were observed throughout the water column for all stations. The Pacific end member had the highest activity of 210Po and 210 Pb in dissolved samples. The calculated partition coefficients (K d) of 210Po and 210Pb varied between 3.2 × 105 to 9.9 × 108 L kg−1 and 7.9 × 105 to 6.9 × 108 L kg−1 respectively and followed a log-linear trend with SPM for particle size fractions. Principal Component Analysis (PCA) and correlation analysis for six major particle phases indicated a significant positive correlation between 210Pb and the lithogenic phase. Both 210Po and 210 Pb had significant negative correlations with opal . Our results suggest that particle composition alone cannot explain the observed variability in K d across the different oceanic regime along the transect. Estimated Kd values from an end member mixing model were found to be within the range of observed Kd values and suggest that higher particulate Mn concentration in the Arctic may be partly responsible for the higher Kd observed in the basin compared to Atlantic and Pacific.
Dynamic interfacial tension measurement under electric fields allows detection of charge carriers in nonpolar liquids.

Abstract Hypothesis Electric fields enhance surfactant transport to oil-water interfaces when the surfactant forms charged aggregates in the oil phase. Hence, transport under electric fields could be used to detect charged surfactant aggregates in nonpolar media. Experiments Two surfactants with different architecture were dispersed in Isopar-M. The transport of surfactants to an oil-water interface under a constant electric field was quantified using a custom-built electrified microtensiometer platform. Electrical conductivity of the oil with surfactant concentration was also measured to determine the presence of charge carriers. Findings The charging mechanism of the oil phase, and field-enhanced transport was different for the two surfactants. At low concentrations where the electrical conductivity of the surfactants is indistinguishable, dynamic interfacial tension measurements under electric fields can ascertain the presence of charge carriers in Isopar-M. The transport of ionic surfactants in the aqueous phase was unaffected by the field, confirming that the field-enhanced transport of oil-phase surfactants is due to electrophoresis of charge carriers. Moreover, the equilibrium interfacial tension was not found to change under an electric field, suggesting the adsorption isotherm is independent of the field strength. We demonstrate that dynamic interfacial tension measurements under electric fields is a sensitive technique to detect charge carriers in nonpolar fluids.
CARDIOVASCULAR DISEASE AND CUMULATIVE INCIDENCE OF COGNITIVE IMPAIRMENT: LONGITUDINAL FINDINGS FROM THE HEALTH AND RETIREMENT STUDY

We sought to examine whether people with a diagnosis of cardiovascular disease (CVD) experienced a greater incidence of subsequent cognitive impairment (CI) compared to people without CVD, as suggested by prior studies, using a large longitudinal cohort. We used biennial data collected on adults
In vitro susceptibility of Aspergillus and Fusarium associated with equine keratitis to new antifungal drugs

Objective To determine minimum inhibitory concentrations (MICs) of four fungal species isolated from horses presented with equine fungal keratitis (EFK) in the southeastern United States to previously untested azole, echinocandin, and carboxamide antifungal drugs. Methods In vitro assays were performed to determine the susceptibility of Aspergillus flavus, A. fumigatus, Fusarium falciforme, and F. keratoplasticum to five antifungal drugs representing three modes of action. Results Luliconazole exhibited increased growth inhibition against both Aspergillus and Fusarium compared to commonly used, standard antifungal drugs. MIC values for luliconazole at 0.001-0.002 µg/mL were at least 25-fold lower than all other antifungal drugs tested, including voriconazole. Conclusions The increased antifungal activity of luliconazole observed in this study warrants further investigation for its potential as an antifungal drug for equine fungal keratitis.
Effects of heat treatment and applied stresses on the corrosion performance of additively manufactured super duplex stainless steel clads

Abstract The super duplex stainless steel (SDSS) cladded low carbon steel (LCS) substrates manufactured via laser powder bed fusion technique (LPBF) have been recently developed to enhance the service life of the structural components in highly corrosive environments. As-printed (AP) SDSS clads showed predominantly δ-ferrite matrix with allotriomorphic austenite precipitating at the ferrite grain boundaries. Increasing scan speeds resulted in decreasing austenite phase fraction with a dominant widmannstatten morphology at higher scan speeds. Cladded composites were heat-treated to reduce the high residual and thermal stresses induced by the LPBF process, which decrease the corrosion resistance. Heat treatment restored the δ-γ phase balance, thereby increased the corrosion resistance of the heat-treated (HT) clads as compared to AP clads. Increasing scan speeds resulted in decreasing corrosion resistance for the AP and HT clads. Subjecting the SDSS-LCS composite to tensile stresses increased the corrosion rates; however, these applied stress effects were eliminated by post stressing heat treatments, which restored the corrosion resistance of the clads. The SDSS clads produced at all scan speeds showed no signs of delamination from the LCS substrate, even at failure strains.
Uterine NK cell education: Learning the ropes in pregnancy.

The impact of inhibitory receptor NKG2A-mediated education on uterine NK (uNK) cell responsiveness to vascular remodeling on pregnancy outcomes has remained unclear. In this issue of Immunity, Shreeve et al. show that loss of NKG2A+ uNK cells results in deficient vascularization and restricted fetal growth.
Study of Switching Transients based on dv/dt and di/dt for a GaN-based Two-Level Pole

The faster switching transients of GaN devices lead to extremely low switching loss. This is a key feature that makes GaN devices a potential candidate for power converters driving high speed electric machines. The switching transients occur in tens of nanoseconds leading to very high dv/dt and di/dt. This leads to several challenges for both power converter as well as motor load. Switching device voltage overshoot and insulation stress for motors are key concerns among them. A practical operation of power converter needs to consider minimizing the losses while addressing these challenges. Analytical models for switching transient help in investigating the mitigation of these challenges from the gate drive side. This paper presents a systematic modeling approach that divides the turn-on and turn-off transient intervals of a GaN-based two-level pole into sub-intervals responsible for di/dt and dv/dt. The switching loss contribution of each sub-interval and their role in transient overshoot is highlighted. Using switching device voltage overshoot and motor dv/dt as two important constraints, an optimal gate drive is then proposed, which minimizes the switching loss. Spice simulation results are presented for the proposed optimal gate drive of 650 V, 60 A GaN device operating at 400 V DC bus voltage and 40 A device current.
Nutrient limitation magnifies fitness costs of antimalarial drug resistance mutations

Drug resistance mutations tend to disrupt key physiological processes, and therefore carry a fitness cost. The size of these fitness costs is a central determinant of the rate of spread of these mutations in natural populations so are important to quantify. Head-to-head competition assays provide a standard approach to measuring differential fitness, and have been used extensively for malaria parasites. These assays typically use standardized culture media, containing RPMI 1640, which has a 1.4 to 5.5-fold (mean: 2.6-fold) higher concentration of amino acids than human blood. In this rich media we predict that fitness costs will be underestimated because resource competition is weak. We tested this prediction using an artemisinin sensitive parasite edited to contain kelch-C580Y or R561H mutations conferring resistance to artemisinin or synonymous control mutations. We examined the impact of these single amino acid mutations on fitness, using replicated head-to head competition experiments conducted in media containing (i) normal RPMI, (ii) modified RPMI with reduced amino acid concentration, (iii) RPMI containing only isoleucine, or (iv) 3-fold diluted RPMI. We found a significant 1.3 to 1.4-fold increase in fitness costs measured in modified and isoleucine-only media relative to normal media, while fitness costs were 2.5-fold higher in diluted media. We conclude that fitness costs are strongly affected by media composition and will be significantly underestimated in normal RPMI. Elevated fitness costs in nature will limit spread of ART-resistance but will also promote evolution of compensatory mutations that restore fitness, and can be exploited to maximize selection in laboratory experiments.
Adults with type 2 diabetes benefit from self-management support intervention regardless of depressive symptoms.

Abstract Aims Elevated depressive symptoms are common among adults with type 2 diabetes (T2D). In a secondary analysis from an RCT of a diabetes self-management support intervention that did not target depressive symptoms, we sought to determine if depressive symptoms were reduced by the intervention (i.e., depressive symptoms an outcome) or, alternatively, if intervention effects on hemoglobin A1c were lesser among persons with clinically elevated depressive symptoms (i.e., depressive symptoms an effect modifier). Methods We evaluated a text messaging intervention, REACH, in a diverse (half non-white, half underinsured) sample of N = 506 adults with T2D. Participants completed the Patient Health Questionnaire-8 (PHQ) and A1c tests at baseline and 6 months. We conducted a factor analysis to identify somatic- and cognitive-affective symptoms on the PHQ. We tested our hypotheses with regression models, using interaction terms and subgroup analyses. Results REACH improved depressive symptoms among participants with lower baseline A1c ( Conclusions We found support for the hypothesis that depressive symptoms – both somatic- and cognitive-affective – may be an outcome, rather than an effect modifier, of effective diabetes self-management support interventions.
A TAXONOMY OF CORRUPTION

This article is devoted to providing a working defi nition of corruption and an explanation as to the importance and the effects of corruption. Included is a review of economic implications as we ll as an assessment of corruption as positive, negative, or neutral in its effects on the social, political, and economic environment of a nation.
Denial of handgun purchase: A description of the affected population and a controlled study of their handgun preferences

Abstract This study provided descriptive data on the denial of handgun purchases in California in 1991 and compared the handgun preferences of persons denied, as a result of prior criminal activity, to those of the general population of handgun purchasers. The study population consisted of all 3,589 persons whose handgun purchases were denied in the study year and a random sample of 7,197 persons whose handgun purchases were approved. Of those denied a handgun purchase, 3,276 (91.3 percent) were denied as a result of prior criminal activity; 2,014 (56.1 percent) had been convicted of a violent crime. Fewer than 1 percent of all federally licensed firearms dealers in the state were involved in more than half of all instances of the denial of handgun purchases. Compared to the general population of handgun purchasers, persons denied the right to purchase a handgun as a result of prior criminal activity were more likely to select handguns with barrel lengths of three inches or less (risk ratio [RR] = 1.45; 95 percent confidence interval [CI] = 1.38, 1.54) and were nearly twice as likely to select small, inexpensive handguns (RR = 1.91, 95 percent CI = 1.76–2.07).
Chapter 13. Oxygen as a direct and indirect biological determinant in the vasculature.

Abstract A fundamental function of the vasculature is to deliver oxygen to tissues and organs. The cells that make up the vasculature also require oxygen, and are acted upon by oxygen in direct and indirect ways that can have significant effects on acute and chronic vascular function and morphology. The role that oxygen, or its absence, plays in defining the biology of the vasculature is thus of critical importance, yet remains an area about which there are many gaps in knowledge and understanding. Oxygen‐associated paracrine mechanisms can drive vascular processes such as angiogenesis. The vasculature can also directly sense blood oxygen levels and differentially translate this information into rapid vasoconstriction responses in some vascular beds, and vasodilation in others. Furthering our understanding of how oxygen and hypoxia affect the vasculature may lead to greater insights into the mechanisms and pathogenesis of disease processes involving the vasculature, and lead to new therapeutic paradigms.
Observations of atmospheric tides on Mars at the season and latitude of the Phoenix atmospheric entry

[1] We report on the atmospheric structure derived from atmospheric entry of NASA's Phoenix Mars probe using Phoenix Atmospheric Structure Experiment (ASE) data complemented by Mars Climate Sounder (MCS) temperature-pressure profiles. Oscillations in temperature, caused by thermal tides, have vertical wavelengths of tens of kilometres. Their amplitudes are much larger in individual profiles than in dayside and nightside zonal mean MCS profiles which is inconsistent with sole control by the migrating diurnal tide. In the fixed local time reference frame of dayside MCS observations, temperature varies by >15 K with longitudinal wavenumber 3, which could arise from non-migrating tides produced by the interaction of surface topography with the migrating diurnal tide.
Central Hemodynamics in Prehypertension: Effect of the β-Adrenergic Antagonist Nebivolol

The aim of the current study was to characterize the effects of the novel β-adrenergic antagonist nebivolol on central aortic blood pressures, arterial properties, and nitroxidergic activity in individuals with prehypertension. Prehypertension is emerging as a major risk factor for several adverse cardiovascular consequences. Increased pulse wave velocity, aortic augmentation index, and aortic blood pressures have been linked with augmented risk of cardiovascular disease and mortality. While the effects of antihypertensive drugs on these parameters in hypertensive patients have been studied, there are limited data so far in prehypertension. Fifty individuals with prehypertension were randomized to either nebivolol (5 mg per day) or placebo in a double-blind clinical trial. Patients underwent measurement of pulse wave velocity as well as aortic blood pressure and aortic augmentation index via pulse wave analysis at baseline and 8 weeks. Patients also had blood and urine biochemistries done at each visit. Nebivolol achieved significant reductions in central aortic systolic (P=.011), diastolic (P=.009), and mean arterial blood pressure (P=.002). Pulse wave velocity trended toward improvement but did not achieve significance (P=.088). Nitric oxide production, measured as urinary nitrite/nitrite excretion, also rose substantially in the nebivolol group (by approximately 60%, P=.030). Central blood pressures can be effectively lowered by β-blockade while patients are still in the prehypertension phase, and the effects may be coupled to improve nitric oxide release by the drug.
Informal Rigor and Mathematical Understanding

These two introspective cognitive experiments have shown how the rational imagination can be a satisfactory mental arena for the conduct of rigorous mathematical thinking. The diagrams and other representative imagery used in such thinking need not be external and public, but are capable of being privately constructed, viewed, and analyzed “in the mind's eye”. The conclusion I draw from this and other similar introspective cognitive experiments with. actual proof scenarios is that such examples of rigorous but unformalized mathematical thinking provide a rich source of material for the development of a more authentic model of mathematical reasoning and communicating results than the more limited model offered by the rigid formal systems of traditional mathematical logic. p]It seems clear that in any such realistic model there will have role for the thinking subject. That is to say, we must explicitly include features in the model which capture the way the intuition and imagination deal directly (without the mediation of formal definitions) with spatial and temporal relationships, with order relations, with comparison and combination of quantities, and with elementary manipulations of symbols. p]Understanding the rules and conventions involved in the engineering and operation of formal systems of deduction and computation is itself an example of intuitive and informal mathematics, just as Hilbert long ago stressed in explaining the ideas behind his metamathematics. p]In the end, we are left with the question: how does the ma actually function? To answer, we must watch real minds in action, rather than guessing how idealized minds would work if they existed.
Utilizing Composts in Land Management to Recycle Organics

Florida ranks fourth among states in the USA in population (about five percent of the total), but produces about one-tenth of the solid waste (about 18.4 million Mg annually in 1992). Perceived problems with landfills and incineration are encouraging composting as an environmentally benign way to recycle organics that cannot be reused in better ways. Potentially about 10 million Mg of organics could be composted to produce 3.6 to 5.4 million Mg of compost. Recycling this volume of material will occur only if research can demonstrate beneficial utilization. Thus, the University of Florida and several cooperators initiated a statewide research program to determine the benefits or problems with applying composts in the production of major crops grown in the state. Composts made from mixed municipal solid waste or source-separated wastes (e.g., yard trimmings, mixed waste paper, refuse derived fuel) with or sans biosolids were applied to soils planted to citrus, pines, various vegetables, turfgrass, sod and container grown woody ornamentals.
Violence Within the Family: Social Psychological Perspectives

* The Incidence of Family Violence * Attitudes about Violence in Families * Victims Reactions to Violence * The Dynamics of Family Life * Theories of Aggression * Learning to be Aggressive * Biological Contributions to Family Violence * Nature and Nurture on Display * Legal and Social Service Interventions in Cases of Family Violence * The Prevention and Treatment of Family Violence
Observations of Solar Pulsations

There have been several interesting developments during the last year with regard to global oscillations of the sun. However, because of the very full program of this Joint Discussion and the resulting tight schedule, only one point will be addressed here: the observational evidence for global oscillations of the sun with periods ≤ 1 hr and > 5 min. The most decisive test currently available for identifying global oscillations is their examination for coherence of phase over an extended period of time. This test discriminates against both nonsolar phenomena, such as effects caused by observing through the earth’s atmosphere, and solar phenomena which occur in the frequency range of interest but which are not global oscillations of the sun. The search for this coherence has been conducted using 2 sets of observations from SCLERA, the 1973 observations of Hill and Stebbins (1975) and the 1978 observations described by Caudell et al. (1979). The results of these examinations strongly support the interpretation of the reported oscillations as solar in origin and as global in character. The above observations consist of time chains of diameter measurements made at SCLERA. A list of references may be found in Hill and Stebbins (1975) and Hill (1978) which describe the telescope, the method for defining the solar diameter, the means of measuring the solar diameter, and the data reduction techniques used to produce the final Fourier transforms and associated power spectra of the diameter measurements.
Distinct transcriptional responses elicited by unfolded nuclear or cytoplasmic protein in mammalian cells

Eukaryotic cells possess a variety of signaling pathways that prevent accumulation of unfolded and misfolded proteins. Chief among these is the heat shock response (HSR), which is assumed to respond to unfolded proteins in the cytosol and nucleus alike. In this study, we probe this axiom further using engineered proteins called 'destabilizing domains', whose folding state we control with a small molecule. The sudden appearance of unfolded protein in mammalian cells elicits a robust transcriptional response, which is distinct from the HSR and other known pathways that respond to unfolded proteins. The cellular response to unfolded protein is strikingly different in the nucleus and the cytosol, although unfolded protein in either compartment engages the p53 network. This response provides cross-protection during subsequent proteotoxic stress, suggesting that it is a central component of protein quality control networks, and like the HSR, is likely to influence the initiation and progression of human pathologies.
Airway branching morphology of mature and immature rabbit lungs

The scheme of Horsfield et al. for describing the pulmonary airway tree (J Appl Physiol 52: 21–26, 1982) catalogs each airway according to its order and the difference in order of its two daughters...
Insight into the Neuroendocrine Site and Cellular Mechanism by which Cortisol Suppresses Pituitary Responsiveness to Gonadotropin-Releasing Hormone

Stress-like elevations in plasma glucocorticoids rapidly inhibit pulsatile LH secretion in ovariectomized sheep by reducing pituitary responsiveness to GnRH. This effect can be blocked by a nonspecific antagonist of the type II glucocorticoid receptor (GR) RU486. A series of experiments was conducted to strengthen the evidence for a mediatory role of the type II GR and to investigate the neuroendocrine site and cellular mechanism underlying this inhibitory effect of cortisol. First, we demonstrated that a specific agonist of the type II GR, dexamethasone, mimics the suppressive action of cortisol on pituitary responsiveness to GnRH pulses in ovariectomized ewes. This effect, which became evident within 30 min, documents mediation via the type II GR. We next determined that exposure of cultured ovine pituitary cells to cortisol reduced the LH response to pulse-like delivery of GnRH by 50% within 30 min, indicating a pituitary site of action. Finally, we tested the hypothesis that suppression of pituitary responsiveness to GnRH in ovariectomized ewes is due to reduced tissue concentrations of GnRH receptor. Although cortisol blunted the amplitude of GnRH-induced LH pulses within 1-2 h, the amount of GnRH receptor mRNA or protein was not affected over this time frame. Collectively, these observations provide evidence that cortisol acts via the type II GR within the pituitary gland to elicit a rapid decrease in responsiveness to GnRH, independent of changes in expression of the GnRH receptor.
F1-ATPase with cysteine instead of serine at residue 373 of the α subunit

Abstract Escherichia coli strain AN718 contains the αS373F mutation in F 1 F 0 -ATP synthase which blocks ATP synthesis (oxidative phosphorylation) and steady-state F 1 -ATPase activity. The revertant strain AN718SS2 containing the mutation αC373 was isolated and shown to confer a phenotype of higher growth yield than that of the wild type in liquid medium containing limiting glucose, succinate, or LB. Purified F 1 from strain AN718SS2 was found to have 30% of wild-type steady-state ATPase activity and 60% of wild-type oxidative phosphorylation activity. Azide sensitivity of ATPase activity and ADP-induced enhancement of bound aurovertin fluorescence, both of which are lost in αS373F mutant F 1 , were regained in αC373 F 1 . N -Ethylmaleimide (NEM) inactivated αC373 f 1 steady-state ATPase potently but had no effect on unisite ATPase. Complete inactivation of αC373 f 1 steady-state ATPase corresponded to incorporation of one NEM per f 1 (mol/mol), in just one of the three α subunits. NEM-inactivated enzyme showed azide-insensitive residual ATPase activity and loss of ADP-induced enhancement of bound aurovertin fluorescence. The data confirm the view that placement at residue α373 of a bulky amino acid side-chain (phenylalanyl or NEM-derivatized cysteinyl) blocks positive catalytic cooperativity in F 1 . The fact that NEM inhibits steady-state ATPase when only one α subunit of three is reacted suggests a cyclical catalytic mechanism.
Oxygen consumption, water loss and cuticular lipids of high and low elevation populations of the grasshopper Aeropedellus clavatus (Orthoptera: Acrididae)

1. 1. Oxygen consumption (Vo2), water loss rates (WLR) and cuticular lipid/hydrocarbon composition were determined for high and low elevation populations of the grasshopper, Aeropedellus clavatus. 2. 2. WLR and Vo2 were positively correlated with temperature, with mean values greater for the high elevation population. 3. 3. There was no apparent relationship between either total cuticular lipids or cuticular hydrocarbons and WLR; cuticular hydrocarbon composition was similar for all populations regardless of their elevation. 4. 4. Higher metabolic rates in the high elevation population enable it to complete its life cycle in a shorter period of time and may also contribute to the higher WLR in this population.
Mobility and modality trends in US state personal income

We examine the mobility and modality trends in US state per capita personal income (and its components) during the 1929-1999 period. We find strong evidence of convergence for states, but that the tendency towards convergence (and the associated mobility within the distribution) varies during the period and especially for the 1980s. Our analysis of convergence by income component suggests that transfer income contributes more to the observed convergence than does asset income. We also note that distributional mobility need not be accompanied by high rank mobility and find that trends toward convergence in the US have tended to preserve rank ordering. Cet article cherche a examiner les tendances de mobilite et de modalitequant aux revenus personnels par tete (et a ses composants) aux Etats-Unis pendant la periode qui va de 1929 a1999. Il s'avere de fortes preuves d' une convergence entre Etats qui varie au cours de la periode etudiee (et qui va de pair avec une variation de la mobilite associee au sein de ...
The hippocampus: part of an interactive posterior representational system spanning perceptual and memorial systems

The hippocampus has frequently been viewed as a core long-term memory structure, separate from brain structures mediating other cognitive functions such as working memory and perception. Much the same is true of other medial temporal lobe (MTL) structures such as the parahippocampal gyrus and the perirhinal cortex. Recent evidence suggests, instead, that these latter structures are also important for certain perceptual functions, leading many to propose a representational account of MTL that defines its functions in terms of what is being represented, rather than how long this representation lasts, or which psychological function is being invoked. We discuss a common framework within which perception and memory are seen as involving many, if not most, of the structures in the ventral representational stream, critically dependent on extensive feedforward and feedback processes. A variety of perceptual and memorial phenomena are discussed within this framework, and it is concluded that the hippocampus is in many ways like its neighbors in the MTL, yet has some distinct properties that account for its unique role in episodic memory.
Hepatic uptake, disposition, and metabolism of rubratoxin B in isolated perfused rat liver.

Abstract Isolated perfused rat liver preparations were utilized to measure the hepatic uptake, biliary excretion and metabolism of rubratoxin B. Livers were perfused with 30% rat blood perfusate containing 0.24 μmol labeled rubratoxin B, and a series of timed blood and bile samples were analyzed by high-pressure liquid chromatography, and treated enzymatically for the determination of glucuronide and sulfate conjugates. Blood, bile and liver samples were also radioassayed. Rubratoxin B was removed from the perfusate by a first-order process (monophasically) with a half-life of 207.5 ± 23.7 min (mean ± SE). By 3.5 hr of perfusion, 30% of the total rubratoxin B-derived radioactivity was excreted into the bile. More than 8% of the total dose of rubratoxin B was excreted unchanged into the bile by 3.5 hr. The rates of biliary excretion of rubratoxin B- derived radioactivity and parent compound reached a maximum at 30 min, after which time the rates of excretion decreased monophasically with half-lives of 35.5 and 72 min, respectively. Two major metabolites detected in the bile were the glucuronide and sulfate conjugates, together accounting for 22% of the radioactivity excreted into the bile by 3.5 hr. In addition, at least one major unidentified organosoluble metabolite was detected in the bile.
Consuming the public school

In this essay David Labaree examines the tension between two competing visions of the purposes of education that have shaped American public schools. From one perspective, we have seen schooling as a way to preserve and promote public aims, such as keeping the faith, shoring up the republic, or promoting economic growth. From the other perspective, we have seen schooling as a way to advance the interests of individual educational consumers in the pursuit of social access and social advantage. In the first half of the essay Labaree shows the evolution of the public vision over time, from an emphasis on religious aims to political ones to economic ones and, finally, to an embrace of individual opportunity. In the second half, he shows how the consumerist vision of schooling has not only come to dominate in the rhetoric of school reform but also in shaping the structure of the school system.
Semiconductivity and Diamagnetism of Polycrystalline Graphite and Condensed Ring Systems

The analysis of results obtained from studies of electric resistivity as a function of temperature, and sample preparation, and of other available evidence, leads to a clarification of the electronic processes in the class of substances extending from condensed ring molecular solids to polycrystalline graphite. In all these solids, the electric current flows preferentially along the benzene-ring planes. Scattering of electrons is due to thermal lattice vibrations and to the boundaries of molecular planes, where electrons pass through potential barriers into the neighboring crystallites. These barriers are quite transparent in polycrystalline graphite and baked carbons, since the flow occurs along the carbon-carbon bonds, but are quite opaque in molecular solids where the barriers are due to the presence of foreign atoms attached at the periphery of the molecules.In contrast with the infinite graphite crystal, systems of benzene-rings of finite dimensions possess a finite energy gap between the filled and the conduction bands, the energy gap steadily decreasing with increase of molecular size---from about 1 ev for molecules several benzene rings wide, to 0.2-0.3 ev for systems 30-40A in diameter and to 0.05 ev for graphite crystallites with diameters of the order of 1000A. When in the process of carbonization, foreign atoms are removed from peripheries, the carbon atoms left with free, unattached valencies play a role of donors, that is, become a source of conduction (excess) electrons. The concentration of such excess electrons increases as long as gases are driven out from the carbons, but starts decreasing as a result of growth of crystallite size for samples treated to higher temperatures. The complete interpretation of the dependence of resistivity on temperature is based on a combination of these three factors: scattering, concentration of the excess electrons, and concentration of holes and electrons activated from the lower band (over the energy gap).The anisotropic component of the diamagnetism of condensed ring systems has a twofold origin: (1) diamagnetism of the filled band (closed shell) of resonance ($\ensuremath{\pi}$) electrons, which is proportional to the number of benzene rings in a molecule; and (2) the Landau diamagnetism of the free electrons and holes. The contribution of the Landau diamagnetism is by far the larger of the two for graphite, but decreases fast with the crystallite size and becomes negligible for molecules with diameters of 30A or below, due to an increase in the effective mass of carriers.
Immunotoxicologic assessment of subacute exposure of rats to carbon tetrachloride with comparison to hepatotoxicity and nephrotoxicity.

Abstract The immunotoxicity, hepatotoxicity, and nephrotoxicity of subacute exposure to carbon tetrachloride (CCl 4 ) were evaluated in young adult (8–9 weeks old) male Fischer 344 rats dosed by gavage with CCl 4 for 10 consecutive days at 0, 5, 10, 20 or 40 mg/kg/day. Two days following the last treatment rats were evaluated for alterations in immune function by monitoring the following: body and lymphoid organ weights; mitogen and mixed leukocyte reaction lymphoproliferative responses; natural killer cell activity; and cytotoxic T lymphocyte responses. A separate group of similarly dosed rats was immunized with sheep red blood cells (SRBC) on Day 9 of dosing, and the primary antibody response was assessed 4 days later. Hepatic and renal toxicity were assessed 2 days after the last treatment by monitoring organ weights, serum indicators of hepatic and renal damage, and hepatic cytochrome P450 levels, as well as by histological evaluation. Significant increases in relative liver weights were observed in rats dosed at 40 mg/kg/day. Histologically, these livers displayed mild to moderate vacuolar degeneration and minimal to mild hepatocellular necrosis. In addition, serum levels of aspartate aminotransferase and alnine aminotransferase were elevated at this dosage, as well as at 20 mg/kg/day. There were no renal effects observed at these dosages of CCl 4 . In addition, no consistent alterations were observed in the immune parameters examined in these same animals nor in the rats immunized with SRBC. Furthermore, there was no difference in the antibody response to SRBC in another set of rats dosed at 40, 80, or 160 mg/kg/day CCl 4 . These results indicate that CCl 4 is not immunotoxic in the rat at dosages that produce overt hepatotoxicity.
Temporal Analysis of Hepatitis C Virus Cell Entry with Occludin Directed Blocking Antibodies

Hepatitis C virus (HCV) is a major cause of liver disease worldwide. A better understanding of its life cycle, including the process of host cell entry, is important for the development of HCV therapies and model systems. Based on the requirement for numerous host factors, including the two tight junction proteins claudin-1 (CLDN1) and occludin (OCLN), HCV cell entry has been proposed to be a multi-step process. The lack of OCLN-specific inhibitors has prevented a comprehensive analysis of this process. To study the role of OCLN in HCV cell entry, we created OCLN mutants whose HCV cell entry activities could be inhibited by antibodies. These mutants were expressed in polarized HepG2 cells engineered to support the complete HCV life cycle by CD81 and miR-122 expression and synchronized infection assays were performed to define the kinetics of HCV cell entry. During these studies, OCLN utilization differences between HCV isolates were observed, supporting a model that HCV directly interacts with OCLN. In HepG2 cells, both HCV cell entry and tight junction formation were impaired by OCLN silencing and restored by expression of antibody regulatable OCLN mutant. Synchronized infection assays showed that glycosaminoglycans and SR-BI mediated host cell binding, while CD81, CLDN1 and OCLN all acted sequentially at a post-binding stage prior to endosomal acidification. These results fit a model where the tight junction region is the last to be encountered by the virion prior to internalization.
Symmetry of H+ Binding to the Intra- and Extracellular Side of the H+-coupled Oligopeptide Cotransporter PepT1

Abstract Ion-coupled solute transporters exhibit pre-steady-tate currents that resemble those of voltage-dependent ion channels. These currents were assumed to be mostly due to binding and dissociation of the coupling ion near the extracellular transporter surface. Little attention was given to analogous events that may occur at the intracellular surface. To address this issue, we performed voltage clamp studies of Xenopus oocytes expressing the intestinal H+-coupled peptide cotransporter PepT1 and recorded the dependence of transient charge movements in the absence of peptide substrate on changing intra- (pHi) and extracellular pH (pHo). Rapid steps in membrane potential induced transient charge movements that showed a marked dependence on pHi and pHo. At a pHo of 7.0 and a holding potential (Vh) of −50 mV, the charge movements were mostly inwardly directed, whereas reduction of pHo to below 7.0 resulted in outwardly directed charge movements. When pHi was reduced, inwardly directed charge movements were observed. The data on the voltage dependence of the transient charge movements were fitted by the Boltzmann equation, yielding an apparent valence of 0.65 ± 0.03 (n = 7). The midpoint voltage (V0.5) of the charge distribution shifted linearly as a function of pHi and pHo. Our results indicate that, as a first approximation, the magnitude and polarity of the transient charge movements depend upon the prevailing H+ electrochemical gradient. We propose that PepT1 has a single proton binding site that is symmetrically accessible from both sides of the membrane and that decreasing the H+ chemical potential (ΔμH) or increasing the membrane potential (Vm) shifts this binding site from an outwardly to an inwardly facing occluded state. This concept constitutes an important extension of previous kinetic models of ion-coupled solute transporters by including a more detailed description of intracellular events.
Joseph Weydemeyer's “dictatorship of the proletariat”

(1962). Joseph Weydemeyer's “dictatorship of the proletariat”. Labor History: Vol. 3, No. 2, pp. 208-213.
Mode of Reinforcement, Grade Level, and Task Difficulty in Learning.

Summary.-To explain the inconsistencies reported in research noting different ages of learners, rypes of materials received, and delays of reinforcement, students in Grades 5, 8, and 11 received immediate and delayed reinforcement using easy and difficult material. Dubois residual gain scores were used to factor out the correlation between pre- and posttest scores. Results of analyses of variance indicate inconsistent findings concerning the effect of reinforcement may not be explained by variation in grade level or differences in the difficulty of material separately. A review of previous research concerning the effects of reinforcement on learning emphasized the importance uniformily accredited. Numerous studies comparing immediate versus delayed knowledge of results indicate facilitating effects favoring immediate reinforcement ( Morgan & Morgan, 1935; Angell, 1949; Greenspoon & Foreman, 1956; Landsman & Turkewitz, 1962). However, Rennet ( 1964) concluded that delay in knowledge of results had no detrimental effect on learning after completing a series of 13 human learning experiments. English and Kinzer (1966) reported students receiving delayed knowledge of results scored higher on tests of retention in educational psychology courses than srudents receiving immediate reinforcement. Since previous studies concerning the effects of reinforcement have led to inconsistent findings, how the experimental and behavioral conditions differ among these studies needs to be examined. In an attempt to explain the inconsistencies we note differing ages of learners and the differing types of materials used. It seems possible that these two variables together with different delays of reinforcement might account for the prior inconsisrencies. In other words, the effects of immediate or delayed knowledge of results might vary as the age (grade level) of the learner increases and as the level of difficulty of the material changes. METHOD