cssi/SciSciGPT-SciSciNet huggingface dataset:
Exploring Student Responses Regarding Most Difficult Coursework Prior to Financial and Managerial Accounting

This exploratory study surveys students regarding what they consider to be the most difficult college course taken prior to both financial and managerial accounting. Students also provide insight as to what made those courses difficult. Financial accounting student responses point to math, economics, and natural science courses as being the most difficult. Top factors affecting course difficulty are the professor, course content, and workload. Managerial accounting student responses point to accounting, math, and natural science courses as being the most difficult. Top factors affecting course difficulty are content, professor, and workload.
Characterization of Chlorate Resistant Mutants of Arabidopsis Thaliana in Tissue Cultures

Mutagen-treated populations of Arabidopsis thaliana were screened for chlorate resistance to obtain new lines suitable for the study of nitrate metabolism and for use as markers in tissue culture studies. Plants and cultured tissues of the resistant mutant lines were characterized biochemically and physiologically.
The role of education, participation in departmental decisions, and burnout in social support and consulting networks in juvenile probation departments:

Juvenile probation officers (JPOs) play an important role as decisionmakers for adolescents under their supervision in the community. While some research has examined how individual and organizatio...
Clinical and magnetic resonance imaging characterization of cervical spondylomyelopathy in juvenile dogs

Background Cervical spondylomyelopathy (CSM) occurs because of compression of the cervical spinal cord, nerve roots, or both, usually affecting young adult to older large and giant breed dogs. Juvenile dogs are affected infrequently. Objective To describe clinical and magnetic resonance imaging (MRI) findings in juvenile dogs (≤ 12 months) with cervical spondylomyelopathy. Animals Twenty CSM-affected juvenile dogs. Methods Medical and imaging records for juvenile dogs with CSM were reviewed. History and neurologic examination findings were obtained, including follow-up data. The MRI studies were reviewed for cause and site of spinal cord compression, intervertebral disk protrusion or degeneration, articular process degenerative changes, intervertebral foraminal stenosis, and spinal cord signal changes. Results Mean (median) age at the time of diagnosis was 9.4 (10) months. There were 16 giant breed dogs. Eighteen dogs had a chronic presentation, 18/20 had proprioceptive ataxia, and 9/20 had cervical pain. On MRI, the principal spinal cord compression occurred at C5-C6, C6-C7, or both in most dogs; 12/20 dogs had ≥2 sites of spinal cord compression. The cause of compression was articular process proliferation in 8/20 dogs and disk protrusion in 2/20 dogs. Intervertebral disk degeneration was seen in 9/20 dogs. Follow-up was obtained for 12/20 dogs: 10/12 were managed medically and 2/12 surgically. Conclusions and clinical importance Cervical spondylomyelopathy in juvenile dogs was characterized mostly by osseous-associated spinal cord compression and multiple compressive sites. Almost half of the dogs had intervertebral disk degeneration. Intervertebral disk protrusion was seen in both giant and large breed dogs.
Safety and Feasibility of Phenylephrine Administration Through a Peripheral Intravenous Catheter in a Neurocritical Care Unit.

Background/Objective:Blood pressure optimization and maintenance of cerebral and spinal perfusion pressure are mainstays in the treatment of a neurocritically ill patient. Traditionally, central ve...
Variations in Adherence to American Urological Association Guidelines for Followup of Children with Vesicoureteral Reflux

AbstractIntroduction:Although the American Urological Association has established clinical guidelines for evaluation of vesicoureteral reflux in children, adoption of these guidelines has not been ...
Preterm births - United States, 2007.

Preterm infants (those born at 30%, from 9.4% to 12.8% of all live births. Although lower during 2007 and 2008, the U.S. preterm birth rate remains higher than any year during 1981--2002.
A powerful fine-mapping method for transcriptome-wide association studies

Transcriptome-wide association studies (TWAS) have been recently applied to successfully identify many novel genes associated with complex traits. While appealing, TWAS tend to identify multiple significant genes per locus, and many of them may not be causal due to confounding through linkage disequilibrium (LD) among SNPs. Here we introduce a powerful fine-mapping method that prioritizes putative causal genes by accounting for local LD. We apply a weighted adaptive test with eQTL-derived weights to maintain high power across various scenarios. Through simulations, we show that our new approach yielded a well-controlled Type I error rate while achieving higher power and AUC than competing methods. We applied our approach to a schizophrenia GWAS summary dataset and successfully prioritized some well-known schizophrenia-related genes, such as C4A. Importantly, our approach identified some putative causal genes (e.g., B3GAT1 and RGS6) that were missed by competing methods and TWAS. Our results suggest that our approach is a useful tool to prioritize putative causal genes, gaining insights into the mechanisms of complex traits.
The Future of DTC Genomics and the Law.

Direct-to-Consumer (“DTC”) genomics has been a controversial topic for over a decade. Much work has been done on the legal issues it raises. This article asks a different question: What will DTC ge...
The oncometabolite L-2-hydroxyglutarate is a common product of dipteran larval development.

Abstract The oncometabolite L-2-hydroxyglutarate (L-2HG) is considered an abnormal product of central carbon metabolism that is capable of disrupting chromatin architecture, mitochondrial metabolism, and cellular differentiation. Under most circumstances, mammalian tissues readily dispose of this compound, as aberrant L-2HG accumulation induces neurometabolic disorders and promotes renal cell carcinomas. Intriguingly, Drosophila melanogaster larvae were recently found to accumulate high L-2HG levels under normal growth conditions, raising the possibility that L-2HG plays a unique role in insect metabolism. Here we explore this hypothesis by analyzing L-2HG levels in 18 insect species. While L-2HG was present at low-to-moderate levels in most of these species ( 100 pmol/mg), with the mosquito Aedes aegypti, the blow fly Phormia regina, and three representative Drosophila species harboring concentrations that exceed 1 nmol/mg – levels comparable to those measured in mutant mice that are unable to degrade L-2HG. Overall, our findings suggest that one of the largest groups of animals on earth commonly generate high concentrations of an oncometabolite during juvenile growth, hint at a role for L-2HG in the evolution of dipteran development, and raise the possibility that L-2HG metabolism could be targeted to restrict the growth of key disease vectors and agricultural pests.
Nonlinear Dynamics and Navigating the End of Life.

As a family physician who migrated to the practice of palliative medicine, I’ve spent the past 20 years pondering the rules American medical culture observes regarding the way people die, and the role of physicians in that final transition. Culture is a nonlinear system where the tension between
Everyday Mysticism: A Contemplative Community at Work in the Desert, by Ariel Gluckich.

Everyday Mysticism: A Contemplative Community at Work in the Desert, by Ariel Gluckich. Yale University Press, 2017. 280pp., Hb. $45.00, ISBN-13: 9780300212099.
Fashion Consumers’ Channel Switching Behavior During the COVID-19: Protection Motivation Theory in the Extended Planned Behavior Framework

The purpose of this study is to understand fashion consumers’ channel switching to online stores during the COVID-19. We proposed an extended theory of planned behavior by incorporating protection ...
Common Sense Commons: The Case of Commonsensical Social Norms

This chapter examines common sense, an important domain of social knowledge. Common sense helps us effectively engage with each other and our complex world, and it often functions as social infrastructure for everyday market transactions and social interactions. Common sense does not mean universal, true, or even accurate; it often is culturally contingent, varied, and erroneous (i.e., common nonsense). The chapter explores governance challenges and the dynamic relationships between common sense, social norms, and technology. [Governing Markets as Knowledge Commons, Cambridge University Press, forthcoming]
The Kokkos EcoSystem: Comprehensive Performance Portability for High Performance Computing

State-of-the-art engineering and science codes have grown in complexity dramatically over the last two decades. Application teams have adopted more sophisticated development strategies, leveraging third party libraries, deploying comprehensive testing, and using advanced debugging and profiling tools. In today’s environment of diverse hardware platforms, these applications also desire performance portability—avoiding the need to duplicate work for various platforms. The Kokkos EcoSystem provides that portable software stack. Based on the Kokkos Core Programming Model, the EcoSystem provides math libraries, interoperability capabilities with Python and Fortran, and Tools for analyzing, debugging, and optimizing applications. In this article, we overview the components, discuss some specific use cases, and highlight how codesigning these components enables a more developer friendly experience.
Molecular Typing Methods for Analysis of Extraintestinal Pathogenic Escherichia coli

Escherichia coli, although perhaps best known as a cause of diarrheal disease, is actually responsible for more morbidity, mortality, and increased health care costs in the developed world as an extraintestinal pathogen. Two main categories of typing methods are relevant for studies involving extraintestinal pathogenic E. coli (ExPEC), including methods that define the strain’s phylogenetic and clonal background (at varying levels of resolution) and those that detect virulence-associated accessory traits. Alternative methods for resolving phylogenetic relationships at the clonal group level that are simpler and cheaper than multilocus sequence typing (MLST) include PCR-based genomic profiling methods, e.g., random amplified polymorphic DNA (RAPD) analysis and repetitive-element (REP) PCR, as performed using the ERIC, BOX, or REP primers. Methods for molecular typing of ExPEC find application in various kinds of studies, including between-population comparisons, assessments of individual isolates for their virulence potential or clonal similarity to other individual isolates, and assessments of colonization and transmission dynamics. The approaches used for statistical analysis of molecular typing data are an important consideration in population level studies involving ExPEC. Molecular typing of ExPEC for phylogenetic and clonal background, as well as accessory traits (e.g., virulence factors) can lead to important new insights into the origins, reservoirs, clinical and commensal behavior, and host group associations of this important group of E. coli. Attention to study design, population selection, specific molecular methods, and appropriate statistical analysis approaches can enhance the quality of typing studies involving ExPEC, which may lead to improvements in human or animal health.
Employer attitudes on hiring employees with disabilities in the leisure and hospitality industry

Purpose – This paper seeks to analyze government survey data on what concerns leisure and hospitality employers most when considering hiring people with disabilities, as well as what hiring practices best alleviate these concerns. Special attention is to be given to the theory of planned behavior in these aims.Design/methodology/approach – US government survey data of leisure and hospitality employers' perspectives were disaggregated and examined using F‐, T‐, and Z‐tests.Findings – Employee abilities and workplace accommodations raised substantial concerns, while financial incentives and practices addressing workplace attitudes were seen as especially helpful solutions. Employer concerns toward hiring varied significantly by employer size, with employers with more workers being more likely to hire those with disabilities than those with fewer workers.Research limitations/implications – Future research should work to overcome limitations inherent in the source data used by further disaggregating business ...
STUDIES OF LYSOSOMES. VI. THE EFFECT OF NEUTRAL STEROIDS AND BILE ACIDS ON LYSOSOMES IN VITRO.

Abstract The effect of steroid hormones and bile acids on the release of hydrolases from lysosomes in granular fractions of rabbit liver and leukocytes has been studied in sucrose suspensions. At concentrations above 2.5 × 10 −4 M, steroids such as etiocholanolone, pregnanedione, pregnanolone, lithocholic acid, and progesterone were found to release β-glucuronidase and acid phosphatase activity from granules of rabbit liver. Metabolic precursors of etiocholanolone, such as testosterone, dehydroepiandrosterone, or 11-desoxycortisol, were active at 37° but not at 20°. Whereas these 5-β-H and Δ4,5 or Δ5,6 steroids released enzymes from the granules into the suspending medium, no 5-α-H isomer, such as androsterone, had comparable activity. Oxygenation or hydroxylation of carbon-11 of pregnanolone or etiocholanolone decreased the activity on the granules of the steroids. Pretreatment of liver granules with cortisol acetate, cortisone acetate, or chloroquine diminished the release of acid hydrolases by etiocholanolone or progesterone. Both etiocholanolone and progesterone reduced the apparent absorbance of suspensions of isolated leukocyte granules, and released β-glucuronidase from the particles, without physically disrupting the majority of granules. The data are compatible with the hypothesis that lysosomes are disrupted by pyrogenic steroids; the relationship of this action in vitro to their fever-provoking capacity in man has yet to be determined.
Illuminating the location of brain glutamate receptors.

Local glutamate application is often achieved by removing a chemical 'cage' with ultraviolet light. Matsuzaki et al. report a new method for uncaging glutamate with infrared light, and show that the shape of individual dendritic spines correlates with AMPA receptor responses.
Photothermal Evaluation of Diffusion Coatings

Chromized and chrome-aluminized coatings, applied to 2.25 Cr-1 Mo and 9 Cr-1 Mo steel substrates by a pack-diffusion process, are being considered for advanced heat exchanger (heat recovery) systems of coal gasifiers [1]. The materials used in this application must have good corrosion resistance and high mechanical strength for prolonged operation at high temperatures (up to 650°C) in the presence of aggressive gas mixtures. The combination of coatings of oxide-forming elements such as Cr and Al (which protect against corrosion) and low-alloy steels (which provide mechanical strength) is economically attractive. The pack-diffusion process is well suited to the application of these coatings to large, complex-shaped components of heat exchangers.
Negocio De China: Building Upon the Santiago Principles to Form an Effective International Approach to Sovereign Wealth Fund Regulation

Sovereign Wealth Funds (SWFs) possess unlimited potential for public wealth creation, but there ought to be some scepticism about state investment activities in the absence of proper regulation. Massive state capital flows could be used as a disguised form of aggressive foreign policy or a destabilising weapon for political rather than financial ends. The “Santiago Principles” (a recent transnational attempt to produce voluntary regulation of such activity) merely reiterate the wanting status quo. If the investment constraints practiced by the new Chinese Investment Corporation (CIC) were adopted as the regulatory model instead, the regime would be far more effective. In this article, the author presents a brief overview of SWF trends, highlighting the growing distinction between capitalism and democracy with the international resurgence of authoritarian-capitalism. Next, the CIC is presented as an example of the possibilities and dangers of state projections of economic power into private markets, including a selection of the Santiago Principles being examined in the context of the CIC’s activities. Finally, three cardinal principles of SWF investing extracted from CIC practice will be offered which should underlie a binding international regime.
The Proton-binding Behavior of Human Hemoglobin and Its Subunits in Their Native State

Abstract The titration of the histidyl and lysyl residues has been investigated in oxy- and deoxyhemoglobin, in apohemoglobin, and in the isolated polypeptide chains with sulfhydryl groups blocked by p-hydroxymercuribenzoate (αpmb and βpmb). The number of titratable histidyl residues was found to be 5 or 6 per chain in hemoglobin and probably 7 in apohemoglobin and in the isolated αpmb and βpmb chains. This indicates that the number of titratable histidines per heme increased by 1 or 2 units per heme when the heme was removed or when the αpmb and βpmb chains were separated. The protonation of these new exposed residues was irrelevant to the helical structure of hemoglobin. The pKint of the lysine residues appeared to vary in the different proteins, being 10.6 in hemoglobin, 10.2 in apohemoglobin, 10.5 in the βpmb chains, and 10.3 in the αpmb chains. The difference shown between hemoglobin and apohemoglobin could indicate that the ionization of some groups in this class is sensitive to conformational changes. The difference in protons bound between apohemoglobin and oxyhemoglobin is consistent with the presence of at least 1 more histidyl residue in apohemoglobin and with a difference in the pK of some e-NH2 group. The difference in protons bound by ferrihemoglobin and oxyhemoglobin proved to be essentially accounted for by the ionization of the water molecule coordinated with the trivalent iron atom.
Naturally occurring antibodies as therapeutics for neurologic disease: can human monoclonal IgMs replace the limited resource IVIG?

Naturally occurring autoantibodies (NAbs) are common in normal humans. The majority of NAbs are IgMs, but a small proportion are IgGs. Therefore a certain portion of pooled whole human IgG (IVIG) can be considered NAbs. While the applications of IVIG to modulate human disease have increased dramatically, the use of IgMs as drugs has lagged. In fact, much of the contaminating IgM component of IVIG is disposed of as waste. However, a number of model studies, including those targeting Alzheimer and multiple sclerosis (MS) suggest that IgMs may better modulate disease at much lower doses than IVIG. Our own studies in a model of MS show that polyclonal human IgM promotes better remyelination than IVIG and that monoclonal IgMs promote greater remyelination than monoclonal IgGs containing identical variable region sequences. We propose that this difference is due to the ability of IgM to cross link cell surface antigens better than IgGs and induce signals in nervous system cells. Monoclonal antibodies (mAbs) that promote remyelination induce a transient Ca2+ influx in myelin forming cells, whereas IgGs with identical variable sequences do not. MAbs that promote remyelination were identified in human serum and in EBV-immortalized human B-cell lines obtained from normal adults, fetal cord blood, and rheumatoid arthritis and MS patients. Therefore therapeutic mAbs are present and common in normal circulation. All therapeutic mAbs were IgMs and bound to nervous system cells, however, the tissue binding patterns suggest that binding any one of multiple antigens induces repair. An expression vector was constructed that can manufacture gram quantities of recombinant monoclonal human IgM. Therefore the technology exists to determine whether human monoclonal NAbs can modulate human disease. IVIG can modulate neurologic disease, but using IVIG to treat these chronic diseases is unsustainable. A long-term solution is to identify the functional component of IVIG and test whether a recombinant human monoclonal can replicate its efficacy.
A New Macroeconomic Forecasting and Policy Evaluation Method

The economy is often faced with a turn that is not to our liking, and we sometimes think it ought to be controllable by macroeconomic policy. While the spectrum of policies ranges from Keynesian “fine tuning” to using monetarist “rules,” every action (or inaction) of the government is a policy. Because of this it is important that government policy makers be guided by appropriate empirical models. Unfortunately, there is considerable variation in the large numbers of econometric models that have been developed thus far. Moreover, there are persistent problems, both technical and theoretical, with these models.
Effects of keto analogues of essential amino acids in portal-systemic encephalopathy

Keto analogues of five essential amino acids (valine, leucine, isoleucine, methionine, and phenylalanine) were given either parenterally or orally in varying proportions to 11 patients with portal-systemic encephalopathy and hyperammonemia. Plasma concentrations of amino acids corresponding to the infused analogues, including alloisoleucine, increased significantly after infusions. Plasma tyrosine and glycine, which were abnormally elevated in control samples, fell after the infusions. After one to five daily infusions, the ratio of essential to nonessential amino acids in fasting plasma was increased toward normal, suggesting improved protein nutrition. Arterial blood ammonia and glutamate did not change immediately after infusions, but a pronounced decrease in glutamine (42%) was observed. Eight nitrogen balance studies performed in 5 patients during 3 to 12 days of oral or intravenous keto acid therapy failed to show consistent improvement in balance as compared with control periods. After five courses of oral therapy there was again significant improvement in the ratio of essential to nonessential amino acids. No toxicity from keto analogue administration was found, and clinical improvement, as assessed by mental status and psychological testing occurred in 8 of 11 patients. These studies suggest keto analogues of essential amino acids are converted to the corresponding amino acids in patients with portal-systemic encephalopathy, and that such therapy may be of benefit.
A finger photoplethysmography waveform during the valsalva maneuver detects changes in left heart filling pressure after hemodialysis

A noninvasive system for determining left ventricular (LV) filling pressure may help to improve personalized fluid removal goals in hemodialysis patients. We previously showed that the change in photoplethysmography (PPG) pulse amplitude measured by finger PPG during a Valsalva maneuver correlates with invasively measured left ventricular end-diastolic pressure (LVEDP). This key PPG change, the ratio of finger PPG pulse amplitude at end-Valsalva to baseline, is known as the Pulse Amplitude Ratio, PAR. The objective of this study was to determine how PAR changes after fluid removal in hemodialysis.
Time‐Varying Risk–Return Trade‐off in the Stock Market

We uncover a strong comovement of the stock market risk–return trade-off with the consumption–wealth ratio (CAY). The finding reflects time-varying investment opportunities rather than countercyclical aggregate relative risk aversion. Specifically, the partial risk–return trade-off is positive and constant when we control for CAY as a proxy for investment opportunities. Moreover, conditional market variance scaled by CAY is negatively priced in the cross-section of stock returns. Our results are consistent with a limited stock market participation model, in which shareholders require an illiquidity premium that increases with CAY, in addition to the risk premium that is proportional to conditional market variance.
Subunit rotation in F0F1-ATP synthases as a means of coupling proton transport through F0 to the binding changes in F1

The rotation of an asymmetric core of subunits in F0F1-ATP synthases has been proposed as a means of coupling the exergonic transport of protons through F0 to the endergonic conformational changes in F1 required for substrate binding and produce release. Here we review earlier evidence both for and against subunit rotation and then discuss our most recent studies using reversible intersubunit disulfide cross-links to test for rotation. We conclude that the gamma subunit of F1 rotates relative to the surrounding catalytic subunits during catalytic turnover by both soluble F1 and membrane-bound F0F1. Furthermore, the inhibition of this rotation by the modification of F0 with DCCD suggests that rotation in F1 is obligatorily coupled to rotation in F0 as an integral part of the coupling mechanism.
The postdoctoral workforce.

In their Editorial “Supply without demand” (20 Feb., p. [1105][1]), D. Kennedy et al. incompletely address what is arguably the fundamental driver of postdoctoral policy. The largest numbers of postdocs are found in the biomedical sciences, and none of the key power brokers in that sector—the NIH, the universities, or faculty investigators—have incentive to change the current situation, which produces the maximum science for the dollars invested. In the late 1980s, Stanford University accepted a proposal from the medical school to create an Office for Post-Doctoral Affairs, to matriculate all postdocs as students in order to regulate their compensation, to ensure that they had respectable benefits packages, and to let the institution know how many there were. Numerous institutions have subsequently undertaken similar kinds of initiatives. In 1998, the Association of American Universities recommended formalization of the status of postdocs as trainees within universities, management of compensation and benefits, and limitation of the total duration of the postdoctoral experience. In 2000, the National Academy of Sciences' Committee on Science, Engineering, and Public Policy released an unusually blunt report calling attention to the continuing plight of postdocs and urging remediation by both the universities and NIH. Partly in response to that report, in 2001, an internal committee at NIH recommended a substantial step-wise increase in the compensation of postdocs (and graduate students) over 5 years, a recommendation that received mixed faculty reaction, and whose fate seems now sadly threatened by the flattening NIH budget. Despite these positive efforts, problems persist, particularly the growing disproportion between the numbers of postdocs and junior tenure-track faculty slots. The solution in biomedicine, where the demand for postdocs is real, is not a forced reduction of supply. It would be far better for NIH, the universities, and the scientific societies to come together to create the mechanisms to provide stable, attractive career opportunities for these highly skilled and dedicated men and women, for whom, I predict, tenure-track opportunities will remain scarce for a long time to come. Universities and medical schools have been remarkably resourceful in creating varieties of nontenure-accruing faculty tracks to meet their workforce demands in the clinic. It is time for them to demonstrate the same resourcefulness in meeting their needs in the laboratory. In both areas, a skilled labor force is required to perform the institution's work; in both areas, that workforce should be treated with respect. [1]: /lookup/doi/10.1126/science.303.5661.1105
Lambda and the question of confidence

Abstract Whenever failure rates or mean times between failures are quoted confidence limits should be given. The tables and graphs described in this paper provide a quick method for their estimation.
Tadalafil Prevents Acute Heart Failure with Reduced Ejection Fraction in Mice

Purpose Phosphodiesterase-5 (PDE5) inhibitors were shown to exert powerful protection in various animal models of cardiomyopathy. Tadalafil is a long-acting and highly specific PDE5 inhibitor, which makes it the most attractive in its class for long-term management of patients with heart failure. We studied the effects of tadalafil in attenuating ischemic cardiomyopathy in mice.
Groundwater recharge estimation and regionalization: the Great Bend Prairie of central Kansas and its recharge statistics

Abstract The results of a 6 year recharge study in the Great Bend Prairie of central Kansas are statistically analyzed to regionalize the limited number of site-specific but year-round measurements. Emphasis is placed on easily measured parameters and field-measured data. The results of the statistical analysis reveal that a typical recharge event in central Kansas lasts 5–7 days, out of which 3 or 4 days are precipitation days with total precipitation of ≈ 83 mm. The maximum soil-profile water storage and the maximum groundwater level resulting from the recharge event exhibit the lowest coefficients of variation, whereas the amount of recharge exhibits the highest coefficient of variation. The yearly recharge in the Great Bend Prairie ranged from 0 to 177 mm with a mean of 56 mm. Most of the recharge events occur during the months of April, May, and June, which coincide with the months of highest precipitation in the region. A multiple regression analysis revealed that the most influential variables affecting recharge are, in order of decreasing importance, total annual precipitation average maximum soil-profile water storage during the spring months, average shallowest depth to water table during the same period, and spring rainfall rate. Classification methods, whereby relatively homogeneous hydrologic-unit areas based on the four recharge-affecting variables are identified, were combined with a Geographic Information Systems (ARC/INFO) overlay analysis to derive an area-wide map of differing recharge regions. This recharge zonation is in excellent agreement with the field-site recharge values. The resulting area-weighted average annual recharge for the region is 36 mm.
The steroid 17α-hydroxylase activity of the immature rat ovary

Abstract The steroid 17α-hydroxylase activity of the microsomal (105,000 g ) fraction of ovaries obtained from hypophysectomized immature rats was measured using a tritium exchange assay with 17α[ 3 H]-pregnenolone or 17α[ 3 H]-progesterone as substrates. The tritiated water produced by hydroxylation of progesterone was highly correlated with the amount of 17-hydroxyprogesterone produced and measured by radioimmunoassay. Pregnenolone appeared to be the preferred substrate. Although the substrates competitively inhibited hydroxylation of each other, the K i for progesterone was greater than that for pregnenolone. The hydroxylation of progesterone was inhibited to a lesser degree than that for pregnenolone when 20α-dihydroprogesterone was present at half the concentration of the substrate. Only hydroxylation of progesterone was inhibited by 20α-dihydropregnenolone. Enzyme activity decreased following hypophysectomy with a half-time of about 33 h. Administration of pregnant mare's serum gonadotropin ( PMSG ) or human chorionic gonadotropin (hCG) resulted in a dramatic and rapid decrease in activity. However, within 24 h following a single injection of PMSG, or multiple injections of hCG, the specific activity of the enzyme increased. Ovine LH or FSH, but not FSH whose LH activity had been neutralized with antiserum, caused an initial decrease in activity but they did not produce an increase even with repeated administrations at 12 h intervals. Prolactin reduced the stimulatory effects of PMSG as well as greatly reduced the activity which had been increased by PMSG or hCG. The results indicate that the immature rat ovary contains a labile 17-hydroxylase activity which can be quickly altered by gonadotropic action.
Residence times in compartmental systems with and without inputs

Abstract Mean residence times for certain populations of particles, such as those initially in a given compartment or those which exit from a given compartment, are derived. The previously given mean residence time for all particles is expressed in terms of those constituent mean times. These same concepts are developed for a system under steady input. The washout curve is interpreted and analyzed in terms of these concepts.
Investor Type, Transaction Fees, and Single-Stock Futures

This study, using a dataset from the Options Clearing Corporation, examines the type of investor that aided in the development of single-stock futures. In March 2005, OneChicago instituted a discounted trading fee program for its member firms that is attributed as a primary reason that the depth and breadth of single-stock futures trading by institutions has increased so dramatically above the trading volume of individuals, who were primarily responsible for the market9s initial growth.
Evaluation of membrane surface charge density: A discussion of some models

The theory of electrical double layer due to Gouy and Chapman, applied to the experimental data related to shifts of conductance—voltage curve along the voltage axis following changes in the external calcium concentration to derive values for the density of surface charges (σ) present on biomembranes, has been outlined. Similarly, the principal equations of resting membrane potential due to Kobatake and coworkers, also used for the first time by Lakshminarayanaiah to evaluate charges on biomembranes of several tissues, have been given. The values for σ derived by the first method have been considered to indicate the charge density at the channel region through which permeation of Na or K ion occurred. The values for σ derived by the second method are considered to represent the presence of charges smeared out uniformly over the membrane surface. Despite this difference in practical implementation of the concepts of the two theories which initially in their development are based on the assumption of charges covering the membrane surface uniformly, the ultimate values for σ derived by the two methods agree. The significance of this result in relation to different membrane models for surface charges is briefly discussed.
EXPERIMENTAL INVESTIGATION OF THE VALUE OF THE VARIOUS COMMERCIAL OVARIAN EXTRACTS

Much has been done and written on the therapeutic value of the numerous endocrine preparations, but unfortunately, most of the work is empirical in nature. While it is true that many valuable facts have been acquired in this way, still it seems that the mass of evidence is based on the interpretations of the investigators and the statements of the patients, which statements may be influenced psychically. It would be much more advantageous if we could experimentally demonstrate the clinical value or a definite physiological activity of the commercial endocrine products, and be able at any time to duplicate the results. There are many objections to the empirical method in addition to those mentioned above, for we know that it is extremely difficult at the present time to classify accurately the various types of endocrinological syndromes, with few exceptions, and in addition, the overlapping of groups makes the results of investigation more uncertain.
Potential halogenated industrial carcinogenic and mutagenic chemicals III. Alkane halides, alkanols and ethers

A variety of alkane halides, alkanols and ethers, analogous to the previously considered halogenated unsaturated (Part I) and saturated hydrocarbons (Part II) possess significant utility in a broad spectrum of applications including: solvents, fumigants, propellants and intermediates in the production of other chemicals, textiles, plastics and ion-exchange resins. Ethylene dichloride and dibromide, propylene dichloride; dibromochloropropane; 2-chloroethanol; 1-chloro-2-propanol; 2,3-dibromo-1-propanol; bis(chloromethyl)-, chloromethyl methyl-, bis(2-chloroisopropyl)-, and bis(2-chloroethyl-ethers were reviewed principally in terms of their synthesis, areas of utility, stability, distribution, reactivity, levels of exposure, population at risk, metabolism, carcinogenicity and mutagenicity.
Thoughts on Alternative Designs for Clinical Trials for Ebola Treatment Research

The current Ebola virus disease (EVD) outbreak in West Africa has already, even before it has ended, resulted in a spate of articles in both the technical and lay literatures that could fall under ...
Dielectric spectroscopy of ionic solids

(1991). Dielectric spectroscopy of ionic solids. Radiation Effects and Defects in Solids: Vol. 119-121, No. 1, pp. 217-222.
Diffusion in a ternary gas system with application to gas separation

Abstract Measurements are reported of the separation effected by diffusion of a gaseous mixture of hydrogen and nitrogen through two organic vapours for the cases of (a) stagnant vapour and (b) countercurrent flow of the vapour relative to the hydrogen and nitrogen. Comparison of the data with classical diffusion theory is facilitated by the use of simple geometry in the diffusion zone, and by careful control of the experimental boundary conditions. In general, the data agree well with theory based on a one-dimensional diffusion model, for both stagnant and flowing vapour. The role of countercurrent vapour flow in effecting large enrichments is particularly emphasized. For example, the measured separation factor for a hydrogen-nitrogen mixture was increased about thirty-fold when the mass flow of vapour was raised from zero to about three times the rate of feed flow. The theoretical analysis is extended to determination of performance characteristics for a practical diffusion stage separating isotopes of low natural abundance of the light component.
Angular distributions of low-energy neutrons from 390-MeV/nucleon Ne+Pb collisions

Multiplicity-selected angular distributions of low-energy neutrons from collisions of 390 MeV/nucleon Ne+Pb are peaked forward, in contrast to relatively flat distributions of protons from Ne+U. A model that includes both Coulomb repulsion and composite-fragment formation accounts for the neutron and proton distributions, and the dependence on nucleon energy of the n/p ratio of inclusive cross sections. This comparison casts doubt on the interpretation of the suppression of forward proton emission as a signal of collective flow.
Performance of fractional watt ion exchange membrane fuel cells

The effect of design and operational variables on the performance of one type of hydrogen-oxygen ion exchange membrane fuel cell has been studied. Only the results of cells based on a phenolsulfonic acid formaldehyde type of ion exchange membrane containing one type of reinforcement are described. Platinum, palladium, iridium, and rhodium are adequate electrode materials for room-temperature operation. Performance of cells with platinum gauze current collectors bonded to the cell surfaces was only slightly better than that with external contacts about 1 cm. apart. Open circuit voltages range from 0.9 to 1.1 v. (theoretical 1.23) depending on the catalyst. The typical current at 0.5 v. is 30 ma./sq. cm. Better cells have delivered 80 ma./sq. cm. at 0.5 v. Life tests indicate that these cells can be expected to deliver a minimum of about 40 amp.-hr./sq. cm., when operated in the load range 8.5 to 230 ohm sq. cm., before failure of the electrolyte owing to pinhole formation. Current efficiency is very nearly 100%. Cell performance vs. temperature in the range 0° to 85°C. shows a maximum at about 55°C.
Children's Privacy in the Home Developmental, Ecological, and Child-Rearing Determinants

Developmental and ecological determinants of children's use of privacy markers (such as closed doors) and rules (such as knocking and access limitations) in the home environment were investigated. ...
Biological and physical properties of a strain variant avian pox virus.

Abstract A study of the biological and physical properties of a filterable agent, previously believed to have been derived from a human wart, is presented. The virus is filterable through Seitz disks and through millipore membrane filters with considerable loss in infectivity. In electron micrographs of partially purified preparations the viral particles appear loaf-shaped with dimensions of 270 by 300 mμ. The agent is quite resistant to heat, its stability at 50° further suggesting its possible arthropod transmissibility by purely mechanical means. Complete inactivation by ultraviolet irradiation, as determined by egg assay, is achieved at a dosage of 800 ergs. The virus produces pocks on the chorioallantois of embryonated eggs featured histologically by ectodermal proliferation and desquamation, and massive hyperplasia of the mesoderm. While the virus is capable of causing cutaneous papillomas in the chicken, turkey and canary, it is only in the canary skin lesions that intracytoplasmic inclusions are observed. The virus is also lethal to the canary, producing marked hyperplasia of bronchial epithelium with formation of cytoplasmic inclusion bodies. The results, generally, confirm an earlier host range and serological identification of this agent as a strain variant of canary pox virus.
A component based methodology for web application development

Today's enterprises increasingly rely on the Web to support their operations, global business alliances, and integration of their business processes with those of their suppliers, partners, and customers. In order to stay competitive, businesses, must also respond to changing business and competitive environments in near real-time. This requires that the architecture and design of business systems and applications should allow quick reconfiguration as well as collaboration among distributed software components. Existing software design methodologies often lack the Web focus and explicit support for componentization. This paper presents a methodology for requirements analysis and high-level design, specifically for component-based Web applications.Using the Web page as the fundamental building block of Web applications, the proposed methodology introduces page and component classifications, and a set of tags to implement link semantics. Based on these constructs, the methodology then specifies procedures for requirements analysis and design. A running business example is used to illustrate various stages, of the analysis and design process.
Time-dependent multi-dimensional simulation studies of the electron output scheme for high power FELs

The authors examine the performance of the so-called electron output scheme recently proposed by the Novosibirsk group. In this scheme, the key role of the FEL oscillator is to induce bunching, while an external undulator, called the radiator, then outcouples the bunched electron beam to optical energy via coherent emission. The level of the intracavity power in the oscillator is kept low by employing a transverse optical klystron (TOK) configuration, thus avoiding excessive thermal loading on the cavity mirrors. Time-dependent effects are important in the operation of the electron output scheme because high gain in the TOK oscillator leads to sideband instabilities and chaotic behavior. The authors have carried out an extensive simulation study by using 1D and 2D time-dependent codes and find that proper control of the oscillator cavity detuning and cavity loss results in high output bunching with a narrow spectral bandwidth. Large cavity detuning in the oscillator and tapering of the radiator undulator is necessary for the optimum output power.
Reduced Zinc and Copper in the Retinal Pigment Epithelium and Choroid in Age-related Macular Degeneration

Purpose To measure zinc and copper levels in the retinal pigment epithelium (RPE) and choroid complex and in the neural retina in subjects with and without age-related macular degeneration (AMD). Design Laboratory investigation. Methods Eighty-eight donor eyes (44 subjects) were analyzed. After retinal dissection, the RPE and choroid complex was photographed. Using the Minnesota Grading System (MGS), the RPE and choroid complex was classified into 1 of 4 stages as defined by the Age-Related Eye Disease Study. Subjects without AMD were defined as both eyes having MGS stage 1; subjects with AMD were defined as both eyes having MGS stages 2 through 4. Zinc and copper levels were determined by using an inductively coupled plasma-mass spectrometer. Metal levels from two eyes of the same subject were averaged and treated as one observation. Differences in metal levels were examined by using Wilcoxon rank-sum tests. Results The mean RPE and choroid complex zinc level in subjects with AMD (± standard deviation, 223.7 ± 94.0 μg/g; n=15) was reduced 24% when compared with that of subjects without AMD (292.1 ± 98.5 μg/g; n=29; P = .01). The mean RPE and choroid complex copper level in subjects with AMD (5.1 ± 1.1 μg/g) was reduced 23% when compared with that of subjects without AMD (6.6 ± 1.4 μg/g; P = .002). No difference was detected in retinal zinc and copper levels in subjects with and without AMD ( P > .09). Conclusions Reduced RPE and choroid complex zinc and copper levels in AMD eyes combined with previous information that oral supplementation of zinc plus copper reduces the risk of progression of AMD suggests that metal homeostasis plays a role in AMD and in retinal health.
A Constitutive Law for Mitral Valve Tissue

Biaxial mechanical testing and theoretical continuum mechanics analysis are employed to formulate a constitutive law for cardiac mitral valve anterior and posterior leaflets. A strain energy description is formulated based on the fibrous architecture of the tissue, accurately describing the large deformation, highly nonlinear transversely isotropic material behavior. The results show that a simple three-coefficient exponential constitutive law provides an accurate prediction of stress-stretch behavior over a wide range of deformations. Regional heterogenity may be accommodated by spatially varying a single coefficient and incorporating collagen fiber angle. The application of this quantitative information to mechanical models and bioprosthetic development could provide substantial improvement in the evaluation and treatment of valvular disease, surgery, and replacement.
COPII coat subunit interactions: Sec24p and Sec23p bind to adjacent regions of Sec16p.

Abstract Formation of COPII-coated vesicles at the endoplasmic reticulum (ER) requires assembly onto the membrane of five cytosolic coat proteins, Sec23p, Sec24p, Sec13p, Sec31p, and Sar1p. A sixth vesicle coat component, Sec16p, is tightly associated with the ER membrane and has been proposed to act as a scaffold for membrane association of the soluble coat proteins. We previously showed that Sec23p binds to the C-terminal region of Sec16p. Here we use two-hybrid and coprecipitation assays to demonstrate that the essential COPII protein Sec24p binds to the central region of Sec16p. In vitro reconstitution of binding with purified recombinant proteins demonstrates that the interaction of Sec24p with the central domain of Sec16p does not depend on the presence of Sec23p. However, Sec23p facilitates binding of Sec24p to Sec16p, and the three proteins can form a ternary complex in vitro. Truncations of Sec24p demonstrate that the N-terminal and C-terminal regions of Sec24p display different binding specificities. The C terminus binds to the central domain of Sec16p, whereas the N terminus of Sec24p binds to both the central domain of Sec16p and to Sec23p. These findings define binding to Sec16p as a new function for Sec24p and support the idea that Sec16p organizes assembly of the COPII coat.