cssi/SciSciGPT-SciSciNet huggingface dataset:
The Role of Post-Ingestive Feedback in the Development of an Enhanced Appetite for the Orosensory Properties of Glucose over Fructose in Rats.

The simple sugars glucose and fructose share a common "sweet" taste quality mediated by the T1R2+T1R3 taste receptor. However, when given the opportunity to consume each sugar, rats learn to affectively discriminate between glucose and fructose on the basis of cephalic chemosensory cues. It has been proposed that glucose has a unique sensory property that becomes more hedonically positive through learning about the relatively more rewarding post-ingestive effects that are associated with glucose as compared to fructose. We tested this theory using intragastric (IG) infusions to manipulate the post-ingestive consequences of glucose and fructose consumption. Food-deprived rats with IG catheters repeatedly consumed multiple concentrations of glucose and fructose in separate sessions. For rats in the "Matched" group, each sugar was accompanied by IG infusion of the same sugar. For the "Mismatched" group, glucose consumption was accompanied by IG fructose, and vice versa. This condition gave rats orosensory experience with each sugar but precluded the differential post-ingestive consequences. Following training, avidity for each sugar was assessed in brief access and licking microstructure tests. The Matched group displayed more positive evaluation of glucose relative to fructose than the Mismatched group. A second experiment used a different concentration range and compared responses of the Matched and Mismatched groups to a control group kept naive to the orosensory properties of sugar. Consistent with results from the first experiment, the Matched group, but not the Mismatched or Control group, displayed elevated licking responses to glucose. These experiments yield additional evidence that glucose and fructose have discriminable sensory properties and directly demonstrate that their different post-ingestive effects are responsible for the experience-dependent changes in the motivation for glucose versus fructose.
Chapter 9 – Lung Cancer

This review summarizes how gene expression profiling is leading to new approaches in lung cancer screening, classification, diagnosis, and treatment. The early diagnosis/screening of lung cancer section summarizes the current studies that use genomic profiling to identify the subset of smokers who are at high risk for developing lung cancer. The classification and prognosis section describes how genomic expression profiling of lung cancer has identified prognostic genes, thus potentially identifying patients who would benefit from improved diagnostic and treatment options. The pathogenesis and treatment of lung cancer section describes how genomics has advanced our ability to predict dysregulation of oncogenic pathways in lung cancer, thus potentially offering an opportunity for developing new pathway-specific therapeutics.
Elective Hospitalizations for Intractable Headache: Outcomes and Response Predictors.

Objective To review our inpatient experience treating a variety of headache disorders with heterogeneous therapies and to determine outcomes and predictors of response. Methods We conducted an institutional review board–approved retrospective chart review of elective inpatient headache admissions from the Montefiore Headache Center from 2014 to 2018. We examined factors associated with response and outcomes at discharge and posthospitalization follow-up in an intractable population. Patients received different classes of IV medications including antiemetics, neuroleptics, dihydroergotamine, lidocaine, steroids, valproic acid, and nerve blocks, and home preventive medications were either continued or changed before discharge. Improvements were defined at discharge by headache intensity compared with before hospitalization. Results Among the 83 admissions, pain improvement at discharge occurred in 90.4% (n = 75) of the overall sample, 89.5% (n = 60) of those with chronic migraine, 75.0% (n = 9) of patients with new daily persistent headache, and 89.5% (n = 34) of all those with acute medication overuse. Fifty-six patients (67.5%) reported improvement of a 3-or-more-point reduction in headache intensity at discharge, with a mean reduction of 4.84 ± SD 2.51 (range 1–10). Of the 66 patients who received IV dihydroergotamine, 59 (89.4%) of them improved at discharge. Of the 11 (13.2%) patients who received IV lidocaine, 7 (63.6%) improved. Of the 14 (16.9%) patients who received nerve blocks, all 14 (100%) improved at discharge. Of the 75 patients who had improved at discharge, 63 (84%) followed up and 50 (79.4%) of those patients remained improved. At the second follow-up, 68 (81.9%) patients returned for follow-up on average of 71 days (range 10–283) after discharge. Conclusions Our inpatient headache experience featured numerous treatments with high rates of improvement in the short and intermediate term for all headache disorders. These results may suggest that stratified hospitalized care including polytherapy may be useful for many patients.
The many lives of Myc in the pancreatic β-cell.

Diabetes results from insufficient numbers of functional pancreatic β-cells. Thus, increasing the number of available functional β-cells ex vivo for transplantation, or regenerating them in situ in diabetic patients, is a major focus of diabetes research. The transcription factor, Myc, discovered decades ago lies at the nexus of most, if not all, known proliferative pathways. Based on this, many studies in the 1990s and early 2000s explored the potential of harnessing Myc expression to expand β-cells for diabetes treatment. Nearly all these studies in β-cells used pathophysiological or supraphysiological levels of Myc and reported enhanced β-cell death, dedifferentiation, or the formation of insulinomas if cooverexpressed with Bcl-xL, an inhibitor of apoptosis. This obviously reduced the enthusiasm for Myc as a therapeutic target for β-cell regeneration. However, recent studies indicate that "gentle" induction of Myc expression enhances β-cell replication without induction of cell death or loss of insulin secretion, suggesting that appropriate levels of Myc could have therapeutic potential for β-cell regeneration. Furthermore, although it has been known for decades that Myc is induced by glucose in β-cells, very little is known about how this essential anabolic transcription factor perceives and responds to nutrients and increased insulin demand in vivo. Here we summarize the previous and recent knowledge of Myc in the β-cell, its potential for β-cell regeneration, and its physiological importance for neonatal and adaptive β-cell expansion.
Inhibitor Binding Modulates Protonation States in the Active Site of SARS-CoV-2 Main Protease

ABSTRACT The main protease (3CL Mpro) from SARS-CoV-2, the virus that causes COVID-19, is an essential enzyme for viral replication with no human counterpart, making it an attractive drug target. Although drugs have been developed to inhibit the proteases from HIV, hepatitis C and other viruses, no such therapeutic is available to inhibit the main protease of SARS-CoV-2. To directly observe the protonation states in SARS-CoV-2 Mpro and to elucidate their importance in inhibitor binding, we determined the structure of the enzyme in complex with the α-ketoamide inhibitor telaprevir using neutron protein crystallography at near-physiological temperature. We compared protonation states in the inhibitor complex with those determined for a ligand-free neutron structure of Mpro. This comparison revealed that three active-site histidine residues (His41, His163 and His164) adapt to ligand binding, altering their protonation states to accommodate binding of telaprevir. We suggest that binding of other α-ketoamide inhibitors can lead to the same protonation state changes of the active site histidine residues. Thus, by studying the role of active site protonation changes induced by inhibitors we provide crucial insights to help guide rational drug design, allowing precise tailoring of inhibitors to manipulate the electrostatic environment of SARS-CoV-2 Mpro.
Neural Network Cognitive Engine for Autonomous and Distributed Underlay Dynamic Spectrum Access

Two key challenges in underlay dynamic spectrum access (DSA) are how to establish an interference limit from the primary network (PN) and how cognitive radios (CRs) in the secondary network (SN) become aware of the interference they create on the PN, especially when there is no exchange of information between the two networks. These challenges are addressed in this paper by presenting a fully autonomous and distributed underlay DSA scheme where each CR operates based on predicting its transmission effect on the PN. The scheme is based on a cognitive engine with an artificial neural network that predicts, without exchanging information between the networks, the full adaptive modulation and channel coding configuration for the primary link that is received with highest power by a transmitting CR. By managing the effect of the SN on the PN, the presented technique maintains the relative average throughput change in the PN within a prescribed maximum value, while also finding transmit settings for the CRs that result in throughput as large as allowed by the PN interference limit. Simulation results show that the ability of the cognitive engine in estimating the effect of a CR transmission on the full adaptive modulation and coding (AMC) mode leads to a very fine resolution underlay transmit power control. This ability also provides higher transmission opportunities for the CRs, compared to a scheme that can only estimate the modulation scheme used at the PN link.
Stress Alters the Effect of Alcohol on Catecholamine Dynamics in the Basolateral Amygdala.

The current rodent study applied in vivo fast-scan cyclic voltammetry (FSCV), paired with a pharmacological approach, to measure the release of the catecholamines (CA) dopamine (DA) and norepinephrine (NE) in the basolateral amygdala (BLA) following locus coeruleus (LC) stimulation. The primary goal was to determine if exposure to either social (social defeat) or non-social (forced swim) stress altered LC-evoked catecholamine release dynamics in the BLA. We used idazoxan (α2 adrenergic receptor antagonist) and raclopride (D2 dopamine receptor antagonist) to confirm the presence of NE and DA, respectively, in the measured CA signal. In non-stressed rats, injection of idazoxan, but not raclopride, resulted in a significant increase in the detected CA signal, indicating the presence of NE but not DA. Following exposure to either stress paradigm, the measured CA release was significantly greater after injection of either drug, suggesting the presence of both NE and DA in the LC-induced CA signal after social or non-social stress. Furthermore, acute administration of alcohol significantly decreased the CA signal in stressed rats, while it did not have an effect in naive animals. Together, these data reveal that, while LC stimulation primarily elicits NE release in the BLA of control animals, both social and non-social stress unmask a novel dopaminergic component of LC catecholamine signaling. Future studies will be needed to identify the specific neural mechanism(s) responsible for these plastic changes in LC-BLA catecholamine signaling and to assess the possible contribution of these changes to the maladaptive behavioral phenotypes that develop following exposure to these stressors.
Examining inequities in rates of undiagnosed HIV and rectal STIs in a large nationwide cohort study of sexual minority men.

Objective Sexual minority men (SMM) of colour are disproportionately impacted by HIV and bacterial STIs (bSTIs). To better understand within-group heterogeneity and differential risk factors by race and ethnicity, we sought to examine rates of undiagnosed HIV and rectal bSTI at the intersection of racial and ethnic identity with other sociodemographic factors. Methods We examined data from 8105 SMM conducting home-based self-testing at enrolment in a nationwide cohort study collected from November 2017 to August 2018. We conducted analyses stratified by racial and ethnic groups to examine within-group (ie, subgroup) unadjusted rates of HIV and rectal bSTI infection across a range of characteristics. Results Rates of undiagnosed HIV were highest among Black (4.3%, n=39) and Latino (2.4%, n=38) SMM, with lower rates among those identified as multiracial (1.6%, n=15), white (1.3%, n=56) and other races (1.3%, n=6). Across the stratified analyses of HIV infection, 15 significant associations emerged showing that age, region, insurance type, sexual positioning and incarceration history had differential impacts across racial and ethnic groups. In particular, private and public insurance were protective against HIV for white but not Black and Latino SMM, and incarceration was associated with substantially higher rates of HIV infection for Black and Latino SMM relative to white SMM. We found significant co-occurrence of HIV and bSTI rates for participants who identified as Latino (OR=7.5, 95% CI 2.12 to 26.54), white (OR=3.19, 95% CI 1.14 to 8.98) and multiracial (OR=5.5, 95% CI 1.08 to 27.90), but not those who identified as Black (OR=0.82, 95% CI 0.10 to 6.56) or other races (OR=3.56 95% CI 0.31 to 40.80). Conclusions Stratified analyses showed differential rates of HIV infection at the intersection of racial and ethnic groups with other characteristics, particularly insurance status and incarceration history, pointing to structural inequities rather than individual behaviours underlying disproportionately high rates of HIV for Black and Latino SMM.
Mortgaging Human Capital: FederallyFunded Subprime Higher Education

Table of ContentsI. Introduction 440II. The Business Model of For-Profit Colleges 449A. Enrollment Growth 449B. Aggressive Recruiting 451C. High Net Price 452D. Reliance on Federal Grant Aid and Student Loans 455E. Higher Debts and Higher Default Rates; Lower Graduation and Repayment Rates 457F. Less Spending on Instruction 461G. Recent Declining Enrollment 462III. The Weak Regulatory Framework and Lack of Relief for Debtors 462A. History of Federal Support for For-Profit Institutions 462B. New Gainful Employment Rule 465C. Lack of Sufficient Debt Relief in Bankruptcy or Otherwise 472TV. Assessing the Government's Role 477A. The Analogy to Subprime Mortgages 477B. The Questionable Policy of Relying on For-Profit Higher Education as the Means to Expand to Universal Higher Education 480V. Conclusion 484I. IntroductionFor-profit colleges have expanded rapidly in the last decade, using primarily federal student grant and loan funds for their revenue.1 As will be detailed here, these schools, also known as career or proprietary colleges, produce on average significantly higher debt burdens and default rates for former students than other sectors of higher education, indicating many of the forprofit colleges do not achieve their mission of preparing students for "gainful employment."2 Because so many former students of these institutions will not be able to repay, it is appropriate to classify for-profit higher education as involving fringe credit.3 Even though much of the credit is in the form of federal student loans with reasonable interest rates,4 the label "subprime higher education" accurately captures the nature of the risk to individual students. Some students in addition take out private loans to go to for-profit colleges, further upping the risk of default.5 Furthermore, the demographic profiles of those taking out student loans to go to for-profit schools - disproportionately poor, minority, single parents, and military personnel - are similar to the targets of other fringe credit providers, such as payday lenders and the purveyors of subprime mortgages involved in the mortgage crisis.6 The limited academic preparation of many career college students contributes to the high-stakes gamble of taking on large educational debt.7Lately there is much discussion of whether higher education in general is "worth it."8 The answer is likely to be no for much of subprime higher education, as will be detailed below. Under a principle of "worst things first," for-profit colleges deserve regulatory and enforcement attention. That other higher education could benefit from reform, too, is not grounds for ignoring the need for targeted regulation of for-profit colleges.9 At a minimum, that regulation should put the worst performers out of the business of living on federal funds, which is what the U.S. Department of Education (DOE) plans to do under its new Gainful Employment Rule,10 scheduled to go into effect July 1, 2012.11 This rule will not eliminate the waste of taxpayer dollars or the human pain to former students caused by this industry,12 but it is a start. …
Adsorption of ethylenediamine on Cu surfaces: attributes of a successful capping molecule using first-principles calculations.

The shape-controlled synthesis of Cu nanocrystals can benefit a wide range of applications, though challenges exist in achieving high and selective yields to a particular shape. Capping agents play a pivotal role in controlling shape, but their exact role remains ambiguous. In this study, the adsorption of ethylenediamine (EDA) on Cu(100) and Cu(111) was investigated with quantum density functional theory (DFT) to reveal the complex roles of EDA in promoting penta-twinned Cu nanowire growth. We find EDA has stronger binding on Cu(100) than on Cu(111), which agrees the general expectation that penta-twinned Cu nanowires express facets with stronger capping-molecule binding. Despite this stronger binding, ab initio thermodynamics reveals the surface energy of EDA-covered Cu(111) is lower than that EDA-covered Cu(100) at all solution-phase EDA chemical potentials, so there is no thermodynamic driving force for penta-twinned nanowires. We also investigated the capability of EDA to protect Cu surfaces from oxidation in water by quantifying energy barriers for a water molecule to diffuse through EDA layers on Cu(100) and Cu(111). The energy barrier on Cu(100) is significantly lower, which supports observations of faster oxidation of Cu(100) in electrochemical experiments. Thus, we elucidate another possible function of a capping agent – to enable selective oxidation of crystal facets. This finding adds to the general understanding of successful attributes of capping agents for shape-selective nanocrystal growth.
Perpendicular Anisotropy and Domain Structure in Granular Magnetic Solids

Granular Co-Ag materials with low Co contents exhibit giant magnetoresistance and single domain magnetic properties. In this paper, we discuss unusual hysteresis behavior that we have observed in Co rich samples, where the magnetization is approximately linear with the applied field up to saturation, and the coercivity and remnant magnetization are both nearly zero. We attribute this unusual behavior to a perpendicular anisotropy that depends on the nanostructure in the phase-segregated materials. These results are corroborated by magnetic domain imaging using scanning electron microscopy with polarization analysis (SEMPA).
Effects of Disturbance, Succession and Management on Carbon Sequestration

The C dynamics in forests depends on the natural processes and perturbations by ACC (see Chapter 2). In primary forests (i.e., forests of native species without clear indications of human activity and no significant disturbance of ecological processes) natural C sequestration processes are in effect (FAO 2006a). The primary forests occupy about one-third of the global forest area (Table 3.1). To fully account for the C sequestration potential of forests, however, the temporal changes in forest structure and function at the stand and landscape level, and their effects on the net primary productivity (NPP) and the net ecosystem C balance (NECB) must be assessed. Forest dynamics are one of the greatest sources of uncertainty in predicting future climate (Purves and Pacala 2008). Specifically, models of ACC effects do not incorporate episodic disturbances such as fires and insect epidemics (Running 2008). The annual C storage in forests depends, in particular, on disturbances, forest succession, and climate variation (Gough et al. 2008). Disturbance is any factor that significantly reduces the overstory leaf area index (LAI) for more than one year or an event that makes growing space available for surviving trees (Oliver and Larson 1996; Waring and Running 2007). The long-term net C flux from forests depends on changes in the rates of disturbance (Goward et al. 2008). High frequency of disturbances, for example, results in low wood biomass accumulation (Potter et al. 2008).
Virucidal effect of certain chemical contraceptives on Type 2 herpesvirus

Abstract The virucidal effect of several chemical contraceptives was investigated and the findings are reported. The suspension of Type 2 herpes simplex virus, containing 10 6 to 10 7 tissue culture infectious doses per 0.1 ml., was inactivated on exposure to five different chemical contraceptives. For quantitative estimates of virucidal effect, 10 per cent solutions of these chemical contraceptives were tested with an exposure time of 10 minutes at room temperature. The methods for determination of residual infectivity included both virus assays in cultures of Vero cells and human embryo fibroblasts, as well as the intracranial inoculation of mice. Virus infectivity decreased 1,000- to 10,000-fold after contact with chemical contraceptives, indicating a substantial virucidal effect.
Musings From Nicaragua: My Second Year and Counting

PROBLEM. To create, organize, and implement an international experience for students in a baccalaureate nursing program. METHODS. Returning to Nicaragua after a year, I was confronted with the loss of a friend there who had exhausted treatment options for her breast cancer. Reflecting on this and other realities of healthcare delivery provided a poignant lesson for the author and students in the realities of health care in a developing nation. FINDINGS. International experiences are life changing for students preparing to be nurses and enrich their professors. CONCLUSIONS. International experiences stay with us well beyond the limited time we get to spend in another culture. They have the potential to inspire us to continue to work and serve in the global health community. Our experiences also solidified my commitment to return and to explore more opportunities to both teach and learn from Nicaragua's people with whom we have the privilege to work.
Thrombomodulin Ala455Val Polymorphism and the risk of cerebral infarction in a biracial population: the Stroke Prevention in Young Women Study

The genes encoding proteins in the thrombomodulin-protein C pathway are promising candidate genes for stroke susceptibility because of their importance in thrombosis regulation and inflammatory response. Several published studies have shown that the Ala455Val thrombomodulin polymorphism is associated with ischemic heart disease, but none has examined the association with stroke. Using data from the Stroke Prevention in Young Women Study, we sought to determine the association between the Ala455Val thrombomodulin polymorphism and the occurrence of ischemic stroke in young women. All 59 hospitals in the greater Baltimore-Washington area participated in a population-based case-control study of stroke in young women. We compared 141 cases of first ischemic stroke (44% black) among women 15 to 44 years of age with 210 control subjects (35% black) who were identified by random digit dialing and frequency matched to the cases by age and geographical region of residence. Data on historical risk factors were collected by standardized interview. Genotyping of the thrombomodulin Ala455Val polymorphism was performed by pyrosequencing. The A allele (frequency = 0.85) was associated with stroke under the recessive model. After adjustment for age, race, cigarette smoking, hypertension, and diabetes, the AA genotype, compared with the AV and VV genotypes combined, was significantly associated with stroke (odds ratio 1.9, 95% CI 1.1–3.3). The AA genotype was more common among black than white control subjects (81% versus 68%) but there was no significant interaction between the risk genotype and race (adjusted odds ratio 2.7 for blacks and 1.6 for whites). A secondary analysis removing all probable (n = 16) and possible (n = 15) cardioembolic strokes demonstrated an increased association (odds ratio 2.2, 95% CI 1.2–4.2). Among women aged 15 to 44 years, the AA genotype is more prevalent among blacks than whites and is associated with increased risk of early onset ischemic stroke. Removing strokes potentially related to cardioembolic phenomena increased this association. Further studies are needed to determine whether this polymorphism is functionally related to thrombomodulin expression or whether the association is due to population stratification or linkage to a nearby functional polymorphism.
Transonic airfoil design code

Wind tunnel tests have shown that it is feasible to design high performance supercritical wing sections by solving mathematically the inverse problem of shaping an airfoil so that the transonic flow over it becomes shockless at specified conditions. The construction of shockless flows is most effectively carried out by means of the hodo-graph method based on complex characteristics that has been described in Chapter II. For practical applications it is essential to combine the method with a reliable turbulent boundary layer correction so as to completely suppress separation and any loss of lift associated with it.
Abstract A27: Transposon mutagenesis screen identifies genes conferring resistance to BRAF inhibition in melanoma

Drug resistance states can be affected by altered gene expression levels or functions. We sought to systematically identify genes that could confer resistance to BRAF inhibition in BRAF mutant melanoma by applying a novel transposon mutagenesis screening approach. Resistant genes identified in this study include both well-characterized molecules such as BRAF, CRAF, PTEN and many other genes whose functions have not been previously associated with drug resistance, and encompass functional groups such as signaling pathway components, transcription factors, ubiquitination and sumoylation enzymes, and G-protein coupled receptors. Overexpression of these genes also confers resistance to the MEK inhibitor AZD6244 demonstrating a pathway specific activity. The resistance mechanisms are diverse: some demonstrate elevated ERK or PI3K signaling, while others do not appear to be signaling-related. Two genes identified in this study elicit both ERK and AKT signals and respectively increase the EGFR baseline expression and PLX4720-induced phosphorylation. Combined treatment with EGFR and BRAF inhibitors in these two clones demonstrated marked drug synergy. Taken together with recently published studies implicating EGFR in resistance to BRAF our study indicates that multiple mechanisms of resistance to BRAF inhibitors can converge on EGFR signaling. Our study identifies additional genes that could be used to select patients most likely to benefit from treatments combining EGFR inhibitors with BRAF/MEK inhibitors to overcome resistance. Citation Format: Li Chen, Anahita Dastur, Xunqin Yin, Cyril Benes. Transposon mutagenesis screen identifies genes conferring resistance to BRAF inhibition in melanoma. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Drug Sensitivity and Resistance: Improving Cancer Therapy; Jun 18-21, 2014; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(4 Suppl): Abstract nr A27.
The Effectiveness of Prophylactic Knee Bracing in American Football: A Systematic Review

Context: Knee injuries, particularly of the medial collateral ligament (MCL), are the most common injury sustained in American football. In 1979, Anderson et al described a knee brace that could protect uninjured knees from MCL injuries resulting from lateral impact. Since then, a number of light and free-moving bracing devices have been developed. However, the efficacy of prophylactic knee bracing remains in question. Objective: A systematic review of the efficacy of prophylactic knee bracing in preventing MCL injuries in football players. Data Sources: Based on MedSearch and PubMed, articles from 1985 to November 2009 were identified with the following keywords and their combinations: prophylactic, prevent injury, knee brace, prevention, medial collateral ligament, MCL, football, and bracing. Study Selection: One randomized controlled trial (level 1 study) and 5 prospective cohort studies (level 2 studies) were selected. Results: The results of the studies were inconsistent; only 1 study showed that prophylactic knee bracing significantly reduced MCL injuries (P
Teaching Multiplication with Regrouping to Students with Learning Disabilities

The Common Core Standards require demonstration of conceptual knowledge of numbers, operations, and relations between mathematical concepts. Supplemental instruction should explicitly guide students with specific learning disabilities (SLD) in these skills. In this article, we illustrate implementation of the concrete-representational-abstract (CRA) sequence and the Strategic Instruction Model (SIM) for teaching multiplication with regrouping to students with SLD. CRA combined with SIM has been shown to be effective in teaching computation for students with SLD, specifically for developing conceptual understanding. Four elementary students with SLD participated in this study. The researchers used a multiple-probe design to show a functional relation. Students demonstrated increases in computational fluency; skills were maintained and generalized.
On processor allocation in hypercube multiprocessors

The processor allocation problem in a hypercube system is to find a free subcube for a given request. The subcube recognition capability of existing allocation strategies, e.g. the buddy strategy and the Gray code strategy, is far below the theoretical upper bound due to their incomplete representation of the hypercube interconnection structure. A complete strategy that outperforms the existing ones in subcube recognition capability and average waiting time but incurs a higher overhead is proposed. Efficient implementation of the complete strategy is also studied. >
Effect of metal ions on the electrochemical reduction of some heterocyclic quinones

Abstract The effect of metal ions on the, reduction of 1,10-phenanthroline-5,6-quinone (1), 5,8-quinolinequinone (II) and 6,7-dichloro-5, 8-quinolinequinone (III) has been investigated in 50% dimethylsulfoxide+water solvent. 1 contains the 1,10-phenanthroline structure in both its quinone and hydroquinone forms, while II and III contain the 8-hydroxyquinoline structure in the hydroquinone forms. Complexation of the hydroquinones of II and III by metal ions causes positive shifts in the quinone half-wave potentials. These shifts have been used to calculate conditional formation constants for Pb2+(II) and Pb2+ and Zn2+(III). The quinone form of I binds strongly to Ni2+, Co2+ and Zn2+ but not to Ca2+. Mg2+. Mg2+. Mn2+ and Pb2+. With the latter four metals, binding to the hydroquinone from of I was detected and formation constants were determined. In addition to binding both the quinone and hydroquinone forms at the nitrogen atoms, Ni2+ Co2+ and Zn2+ formed complexes at the 1,2-dihydroxy site of the hydroquinone of I.
Effect of fibre volume on tensile properties of real unidirectional fibre-reinforced composites

Abstract A simple theoretical model is proposed to account for the effect of high fibre loading on the tensile properties of real, unidirectionally reinforced fibre composites. Based on the reduction of interfacial surfaces due to fibre-fibre interaction, a modification to the rule of mixtures is proposed. The experimentally observed non-linear variation of tensile strength with fibre volume can be predicted by the modified rule. Experimental data from the literature are used to validate and verify the model and show good agreement with the predictions.
Cartilage MRI relaxation times after arthroscopic partial medial meniscectomy reveal localized degeneration

Little is known about the early changes in cartilage composition and tibiofemoral kinematics following partial meniscectomy. The purpose of this study was to determine the effects of partial meniscectomy on cartilage compositional properties using T1ρ and T2 relaxation time mapping and to assess changes in tibiofemoral kinematics. It is hypothesize that abnormal tibiofemoral kinematics and relaxation time elevation (a reflection of changes in cartilage biochemical composition) in the weight-bearing regions of the knees following meniscectomy will be observed. Nine patients (7 males and 2 females; mean age, 48.6 ± 10.8 years; BMI = 27.3 ± 3.8 kg/m2) with tears of the posterior horn of the medial meniscus underwent arthroscopic partial meniscectomy. Pre-surgical and 6 months post-surgical MRIs were obtained in all subjects to evaluate cartilage relaxation times and tibiofemoral kinematics. Paired t tests were performed to determine significant changes in cartilage relaxation times from baseline. T1ρ relaxation time in the region of the medial femoral condyle directly adjacent to the resection showed an increase of 7.4 % at 6 months (p = 0.02). T2 relaxation times in both the medial and lateral tibial plateaus showed significant elevation at 6 months. Consistent kinematic trends were not found in post-meniscectomized knees. These results suggest that arthroscopic partial meniscectomy affects the biochemical composition of articular cartilage in the knee in as early as 6 months. The largest responses were observed in the weight-bearing regions and the cartilage immediately adjacent to the resection. This suggests that the loading environment has been altered enough to result in cartilage compositional changes in a very brief period of time following meniscectomy. IV.
Race: The Mythic Root of Racism

The term “race” was introduced into science two and a half centuries ago as an arbitrary convenience to describe geographic groupings of humans. These ad hoc racial taxonomies were seized upon, however, as “scientific” justification for slavery and other forms of social, political, and economic oppression. Over the last fifty years, geneticists and biologists have quietly abandoned race as a scientific concept, leaving the general public unaware that racial categories, associated only with culturally selected, physically superficial characteristics, are social rather than genetic. As a result, most individuals remain “racist” in the sense of predicating interaction on racial assignments thought to reflect deep physiological differences. Some of these are conventionally recognized “mean racists.” The remainder, however, could well be considered “kind racists,” for their seeming benign tolerance defines limits to integration, and their unreflective perpetuation of the enabling belief of racism, that races exist physiologically, serves as a wellspring for mean racism during social crises. Many societies are thus much more racist than they appear. Since the belief that others are physically distinct tends to extend social distance and exacerbate hostility, analysts of social conflict ignore this pool of hidden racism at their peril.
Immunopharmacological monitoring of cyclosporin A-treated recipients of cadaveric kidney allografts.

Twelve cadaveric kidney allograft recipients, who were established preoperatively to be strong responders, were treated with cyclosporin A (Cy A) and subjected to postoperative monitoring of drug levels and immune performances. The Cy A-treated recipients were compared with 72 historical (36 strong and 36 weak immune responders) and 18 current, strong responder, azathioprine-treated control patients. Estimation of Cy A levels in plasma and whole blood revealed that 75% of the drug at trough and 44% at peak was cell bound. Concomitant radioimmunoassay (RIA) and high performance liquid chromatography (HPLC) determinations on whole blood yielded concordant values. Trough levels above 200 ng/ ml in plasma and 600 ng/ml in whole blood were associated with toxic manifestations. Although absolute peak levels were not helpful, calculation of peak to trough ratios yielded values which when less than 3.0 predicted toxicity. Post-transplant immune monitoring showed administration of Cy A to be associated with fewer (1) rejection episodes; (2) nonspecific immune events; and (3) donor-specific in vitro reactions than were observed after treatment with azathioprine. Although the activity of peripheral blood mononuclear cells as natural killers of K562 target cells was not affected by Cy A treatment, their capacity to suppress the generation of a third-party mixed lymphocyte culture was enhanced to the same degree as cells from azathioprine-treated patients. Enumeration of peripheral blood lymphocyte T cell subpopulations using monoclonal xeonoantisera revealed (1) the total number of T cells to be unaffected by administration of either Cy A or azathioprine and (2) a reduction in the ratio of helper-inducer to suppressor-cytotoxic cells specificially in Cy A-treated recipients compared with normal individuals, hemodialysis patients, or azathioprine-treated recipients. Although pharmacological monitoring of blood levels may be useful to discern patients at high risk for toxic complications, the achievement of maximal therapeutic efficacy may depend upon identifying and quantitating the cellular target responsible for the disruption of immune homeostasis observed during Cy A administration.
Integration and radiality: Measuring the extent of an individual's connectedness and reachability in a network

Abstract This paper presents two measures, integration and radiality, which indicate the degree an individual is connected and reachable within a network. The measures are created using a reverse distance (geodesic) matrix, thus providing a directed closeness measure. Integration and radiality are then correlated with other centrality measures to examine the differences and similarities between each other and these other centrality measures. We then show how integration and radiality are associated with certain demographic and substantive variables. Integration and radiality provide a new index of network structure and our results show how that structure may influence behavior.
Uncovering Transcription Factor Modules Using One- and Three-dimensional Analyses *

Transcriptional regulation is a critical mediator of many normal cellular processes, as well as disease progression. Transcription factors (TFs) often co-localize at cis-regulatory elements on the DNA, form protein complexes, and collaboratively regulate gene expression. Machine learning and Bayesian approaches have been used to identify TF modules in a one-dimensional context. However, recent studies using high throughput technologies have shown that TF interactions should also be considered in three-dimensional nuclear space. Here, we describe methods for identifying TF modules and discuss how moving from a one-dimensional to a three-dimensional paradigm, along with integrated experimental and computational approaches, can lead to a better understanding of TF association networks.
Ballot theorems revisited

Ballot theorems yield a simple relation for the probability that a non-decreasing process with cyclically interchangeable increments and piecewise constant paths stay below a linear function for a certain period of time. A particular instance of the problem is the classical ballot theorem that computes the chance that, in a ballot, votes of type A are always ahead of votes of type B during counting. Traditionally, one uses a combinatorial or analytic lemma to prove such theorems. In this paper we make the simple observation that all ballot theorems can be proved by direct probabilistic arguments if the stationarity of the processes involved is properly taken into account. Our proofs use a queueing theoretic construction and thus yield a physical interpretation to ballot theorems. Furthermore, they reveal the necessity of the assumptions. The auxiliary combinatorial or analytic lemmas are finally derived as a consequence.
Stoichiometric displacement of solvent by non-polar solutes in reversed-phase liquid chromatography

This paper proposes a retention model which predicts that the displacement of non-polar solutes from a reversed-phase chromatographic column is accompanied by the adsorption of a stoichiometric number (Z) of solvent molecules. The number of solvent molecules involved in this process is a function of both solute and solvent contact surface areas. Increasing solute contact surface area would increase Z whereas increasing solvent contact surface area would decrease the Z value for a specific solute. The experimental observations presented are consistent with this model. Further predictions of the model are that (1) plots of log k' versus the inverse log of solvent concentration will be non-linear at solvent concentrations where the surface of a reversed-phase support is not fully solvated, and (2) only a portion of the total non-polar surface area of a molecule actually contacts the surface of a reversed-phase support. Non-linearity in plots of log k' versus the inverse log of solvent concentration was in fact observed at solvent concentrations where solvation of the reversed-phase support is incomplete.
Method- and species-specific detection probabilities of fish occupancy in Arctic lakes: Implications for design and management

Studies examining species occurrence often fail to account for false absences in field sampling. We investigate detection probabilities of five gear types for six fish species in a sample of lakes on the North Slope, Alaska. We used an occupancy modeling approach to provide estimates of detection probabilities for each method. Variation in gear- and species-specific detection probability was considerable. For example, detection probabilities for the fyke net ranged from 0.82 (SE = 0.05) for least cisco (Coregonus sardinella) to 0.04 (SE = 0.01) for slimy sculpin (Cottus cognatus). Detection probabilities were also affected by site-specific variables such as depth of the lake, year, day of sampling, and lake connection to a stream. With the exception of the dip net and shore minnow traps, each gear type provided the highest detection probability of at least one species. Results suggest that a multimethod approach may be most effective when attempting to sample the entire fish community of Arctic lakes. Detection probability estimates will be useful for designing optimal fish sampling and monitoring protocols in Arctic lakes. Resume : Les etudes sur l'occurrence des especes ne tiennent souvent pas compte des fausses absences dans l'echantillonnage sur le terrain. Nous nous sommes penches sur les probabilites de detection associees acinq types d'engins pour six especes de poissons dans un echantillon de lacs de la North Slope, en Alaska. Nous avons utilise une approche de modelisation de l'occupation pour obtenir des estimations des probabilites de detection pour chaque methode. Les variations de la probabilite de detection selon l'engin et l'espece etaient considerables. Par exemple, les probabilites de detection pour le verveux allaient de 0,82 (ET = 0,05) pour le cisco sardinelle (Coregonus sardinella )a ` 0,04 (ET = 0,01) pour le chabot visqueux (Cottus cognatus). Des variables propres au site avaient egalement une incidence sur la probabilite de detection, dont la profondeur du lac, l'annee, le jour d'echantillonnage et la connexion du lac aun cours d'eau. A l'exception de l'epuisette et de la nasse avairons placee sur la rive, chaque type d'engins offrait la probabilite de detection la plus elevee pour au moins une espece. Ces resultats suggerent que le recours aplusieurs methodes pourrait etre l'approche la plus efficace pour l'echantillonnage de la communaute entiere de poissons d'un lac arctique. Les estimations de la probabilite de detection seront utiles al'elaboration de protocoles optimaux d'echantillonnage et de surveillance des poissons dans les lacs arctiques. (Traduit par la Redaction)
Quantitating Genetic and Nongenetic Factors Influencing Androgen Production and Clearance Rates in Men

Both hereditary and nonhereditary factors have a decided influence on plasma sex steroid concentrations in men. We studied the relative contributions of genetic and nongenetic factors on the production rate (PR) and MCR of testosterone and dihydrotestosterone (DHT) and their conversion ratios to other metabolites in monozygotic (MZ; n = 22) and dizygotic (DZ; n = 24) male twins. Zygosity was determined by measurement of 10 blood proteins and enzymes. The kinetic studies were conducted with isotope dilution techniques. The genetic effect was determined from the equation: 2[rmz – rdz], where r is intraclass correlation. A heritability of over 40% was found for the PRs of DHT/body surface area and of testosterone/body surface area. Nongenetic factors accounted for 50% or more of the variation of the conversion ratios for testosterone/3α-androstanediol and DHT/3α-androstanediol. The results suggest that genetic factors markedly influence the PRs of testosterone and DHT, suggesting that the PR of these potent ...
13C kinetic isotope effects in the urease-catalyzed hydrolysis of urea. I. Temperature dependence.

Abstract The 13C kinetic isotope effects in the urease-catalyzed hydrolysis of urea have been measured with several preparations of the enzyme in two buffers (maleic acid-maleate, and Tris-sulfuric acid) in which the kinetics have been studied previously. The results indicate that the mechanism of the hydrolysis possesses complexities not reflected in the gross rate phenomena which do influence the isotope fractionation. The isotopic analogues of the several mechanisms found adequate to explain the kinetics of the reaction are examined in detail. It is concluded that complexity at the molecular level, probably involving temperature-dependent interconversion of two or more types of active sites (directly, or indirectly through enzyme conformational changes), is responsible for the isotope-effect results obtained.
The impact on China of its ascension into the WTO

Abstract China’s ascension into the WTO has and theoretically will result in a more efficient economy and an increased rate of economic growth. These effects follow from the required restructuring of China’s economy from a more or less planned closed economy to a more or less free-market open economy. Although the gains from the transition are potentially immense, everyone will not experience a net gain. The restructuring process will take time, perhaps a great deal of time. The most pressing problem is the economic and social losses attending the displacement of people and property implied by an inevitable massive redistribution of resources. A perplexing, but less serious problem involves the attempted maintenance of the dominance of state owned enterprises in selected industries. Finally, before the benefits of a market-oriented system can be fully realized, the household registration system and other restraints on migration must be completely abandoned.