cssi/SciSciGPT-SciSciNet huggingface dataset:
Galactose clearance and carbohydrate metabolism across the gastrointestinal tract in the newborn lamb.

Abstract We prepared 16 newborn lambs with chronically indwelling catheters in the portal vein, mesenteric vein, femoral vein, and femoral artery to study galactose clearance, portal venous blood flow, and carbohydrate metabolism across the gastrointestinal (GI) tract. Galactose clearance was measured by infusing galactose into the femoral vein to achieve a steady-state galactose concentration in the femoral artery. We observed a curvilinear relationship between galactose clearance and the steady-state galactose concentration. The relationship could be modeled as an apparent Michaelis-Menten system: Clearance = V max (K m + [Gal] a ss ) , where V max = 17.0 ± 2.5 mg/min/kg body weight and K m = 11.0 ± 0.4 mg/dL. Substrate/oxygen quotients across the viscera drained by the portal vein were measured in the fasted state and during systemic galactose infusion. A net uptake of glucose and galactose by the GI tract was found with quotients of 0.19 ± 0.07 and 0.05 ± 0.02, respectively. There was a relatively large net efflux of lactate across the portal circulation, with a quotient of −0.13 ± 0.03. The indicator-dilution technique was used to estimate portal venous blood flow (PVBF) in the neonatal period with a resting, fasted state value of 92.8 ± 4.4 mL/min/kg body weight. This study in the healthy, unstressed, growing newborn lamb demonstrates (1) galactose clearance is a nonlinear function of galactose concentration; (2) the maximal capacity of newborn lambs to metabolize galactose is ∼12 mg/kg/min; (3) GI tract is an extrahepatic site of galactose consumption; (4) there was a significant plasma galactose concentration in the fasting state; and (5) there was a net glucose consumption and lactate production by the GI tract of approximately equal magnitude. These observations of resting galactose concentration and galactose clearance are consistent with resting endogenous galactose production.
Prenatal LHRH Neurons in Nasal Explant Cultures Express Estrogen Receptor β Transcript

Sex steroids influence LHRH neuronal activity, exerting a negative or positive feedback action, depending on the reproductive state of the animal. Recent evidence indicates that LHRH neurons possess the estrogen receptor beta (ERbeta) subtype postnatally, suggesting that estrogen may act, in part, directly on LHRH neurons. In this study, we identified ERbeta transcript in prenatal LHRH neurons as a function of age. Single-cell cDNA pools were made from LHRH neurons maintained for 7, 14, and 28 d in vitro (div). Screening of the cDNA pools by PCR with ERbeta-specific primers revealed ERbeta-positive LHRH neurons at all three ages. However, the number of LHRH cells coexpressing ERbeta transcript decreased dramatically between 14 (6/10) and 28 div (1/10). None of the LHRH cells were positive for ERalpha transcript. These results indicate that developing LHRH neurons express the transcript for ERbeta and suggest that continued expression of ERbeta is either a characteristic of LHRH neurons that may require cues from the central nervous system and/or periphery or predetermined to be maintained in a subpopulation of LHRH neurons.
Identification, Composition, and Asymmetric Formation Mechanism of Glycidyl Methacrylate/Butyl Methacrylate Copolymers up to 7000 Da from Electrospray Ionization Ultrahigh-Resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Glycidyl methacrylate (GMA) and butyl methacrylate (BMA) have the same nominal mass (142 Da) but differ in exact mass by 0.036 Da (CH4 vs O). Therefore, copolymers formed from the two isobaric monomers exhibit a characteristic isobaric distribution due to different monomer compositions. Here, we show that electrospray ionization FT-ICR mass spectrometry at 9.4 T resolves the isobaric components of copolymers as large as 7000 Da with a resolving power (m/Δm50%) of ∼500 000 in a gel permeation chromatography fractionated polymer sample. That resolution provides for complete and unequivocal component analysis of such copolymers of the size used for high solid content automobile coatings. All five possible copolymer products predicted by the polymerization mechanism are resolved and identified in the mass spectrum. Two of those polymer series (each with saturated end group) were previously unresolved by mass spectrometry because they differ in mass from the two other unsaturated products by only 0.0089 Da. Fi...
Idiopathic benign biliary strictures in surgically resected patients with presumed cholangiocarcinoma.

Objective. Distinguishing between malignant and benign biliary strictures remains problematic. The aim of this study was to compare and contrast the clinical features of patients with benign and malignant biliary strictures. Methods. Medical records of patients who underwent surgical resection for presumed cholangiocarcinoma were reviewed. Immunohistochemistry for hypoxia inducible factor-1-alpha (HIF-1-alpha) was performed on all bile ductule samples. Results. Twelve patients with benign strictures (group I) were compared to 26 patients with cholangiocarcinoma (group II). Group I was predominantly female (ratio 2: 1), (p 100 U/ml in 1 patient of group I and 100 in 11 patients in group II. Half of the patients in group I had positive immunoreactivity for HIF-1-alpha in bile ductules. Conclusion. Benign biliary strictures masquerading as cholangiocarcinomas occur more often in women, are less often Bismuth-Corlette type III, have serum CA 19-9 values <100 U/ml, and hypoxia may play a role in a subset of these strictures.
A Reexamination of the Factors Important to Selection of Accounting as a Major

This study reexamines and extends the conclusions drawn from the Felton et al. (FBN) 1994 study that investigated a set of explanatory factors in the decision to choose a career as a chartered accountant (CA). The current study extends the findings of FBN in two primary ways. First, we improve upon their study by adding the students' overall experience in the first accounting course into the analysis. Second, we expand the analysis to include sophomores and juniors rather than seniors only. When we add the students' overall experience in the introductory accounting class into the analysis, it becomes the most important factor in distinguishing major choice between accounting and nonaccounting students. Consistent with FBN, we find that accounting majors place less importance on intrinsic factors and report a higher ratio of perceived benefits to costs of choosing accounting than nonaccounting majors. Unlike FBN, we find that initial earnings, long‐term earnings, and job market considerations rank at or ne...
Validation of a GEANT4 Simulation of Neutron Stimulated Emission Computed Tomography

Neutron stimulated emission computed tomography (NSECT) is being proposed as a non-invasive technique to detect concentrations of elements in the body for diagnosis of liver iron overload. Several experiments have been conducted to investigate NSECT's ability to determine iron concentration in liver tissue and evaluate the accuracy and sensitivity of the system. While these experiments have been successful in demonstrating NSECT's capability of quantifying iron and other tissue elements in-vivo, they have been prohibitively time consuming, often requiring as much as 24 hour acquisitions for accurate quantification. Such extensive scan times limit the use of the experimental system for initial feasibility testing and optimization. As a practical alternative, GEANT4 simulations are being developed to investigate system optimization and aid further progress of the experimental technique. This work presents results of a validation study comparing the results of a GEANT4 simulation with experimental data obtained from a sample of iron. A simulation of the NSECT system is implemented in GEANT4 and used to acquire a spectrum from a simulated iron sample. Scanning is performed with a 7.5 MeV neutron beam to stimulate gamma emission from iron nuclei. The resulting gamma spectrum is acquired and reconstructed using high-purity germanium (HPGe) detectors and analyzed for energy peaks corresponding to iron. The simulated spectrum is compared with a corresponding experimental spectrum acquired with an identical source-detector-sample configuration. Five peaks are detected corresponding to gamma transitions from iron in both spectra with relative errors ranging from 4.5% to 17% for different peaks. The result validates the GEANT4 simulation as a feasible alternative to perform simulated NSECT experiments using only computational resources.
An Application-Based Approach to Presenting Random DSP Concepts to a Non Traditional Study Body

Naval Postgraduate School (NPS) students have on average been out of school for several years and come from a wide range of backgrounds but also have a common work experience. This paper discusses the challenges faced by faculty in teaching a first year graduate-level discrete time random signals course offered for students enrolled towards the MSEE Degree at NPS and the steps taken to facilitate student understanding of the topics covered in the course. We describe our student hands-on approach designed to emphasize applications and report our findings.
Electromigration study of oxygen disorder and grain-boundary effects in YBa 2 Cu 3 O 7-δ thin films

We report on the effects of strong electrical currents (\ensuremath{\ge}1 MA/${\mathrm{cm}}^{2}$) applied at \ensuremath{\sim}300 K to ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$ thin-film microbridges that both do, and do not contain high-angle grain boundaries. In the grain-aligned microbridges, below a certain threshold level such currents promote a slow improvement of the normal and superconductive properties of the microbridge. This behavior is attributable to the current-driven increase in basal-plane oxygen order in a manner characteristic of dispersive transport. Above threshold, the effect of the electromigration current is to create rapidly regions of strong oxygen disorder, which increases the microbridge resistance and decreases the transition temperature and critical current. This disorder shows a tendency to segregate under electromigration bias and can be at least partially removed by reversal of the current. The threshold effect permits an estimate of the atomic force required to promote the creation of oxygen disorder in ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$. The superconducting properties of the disordered regions have the characteristic of a composite superconductor, consisting of a network of superconducting filaments partially shunted by normal conducting paths. Comparison with the behavior of microbridges containing high-angle grain boundaries indicates that such boundaries consist of more or less random connections of these filaments.
Selective inhibition of cardiac cyclic nucleotide phosphodiesterases by doxorubicin and daunorubicin.

Abstract Doxorubicin and daunorubicin, the anthracycline anti-tumor agents, were evaluated for their in vitro and in vivo effect on phosphodiesterase (PDE) activity in mouse tissues. Doxorubicin at a concentration of 10−4M inhibited cardiac c-AMP (adenosine 3′,5′, monophosphate) PDE activity 50% of the control whereas in lungs and spleen, the activity was inhibited only 20%. On the contrary no effect was seen in kidney and liver. In addition, cardiac c-GMP (quanosine 3′,5′ monophosphate) PDE appeared less sensitive to doxorubicin than c-AMP PDE though inhibition in heart was more pronounced than in any other tissue. It appears that daunorubicin inhibits c-AMP PDE activity in heart markedly less than doxorubicin. Kinetic studies indicate that both inhibitions of c-AMP and c-AMP PDE by doxorubicin were non-competitive with substrate. Intravneous administration of 20 and 30 mg/kg of free doxorubicin to CDF1 mice resulted in 33 and 39% decreases in cardiac c-AMP PDE activity respectively by 72 hrs. In contrast, similar intravenous injections of same doses of doxorubicin entrapped in cardiolipin liposomes had no effect on c-AMP PDE activity in any tissues. These studies demonstrate the relative selectivity of the cardiac cyclic nucleotide PDE inhibitory effect of doxorubicin suggesting that this inhibition might be one aspect of the mechanism of anthracycline-induced cardiotoxicity.
Upper-division students’ difficulties with Ampère’s law

This study presents and interprets some conceptual difficulties junior-level physics students experience with Amp\`ere's law. We present both quantitative data, based on students' written responses to conceptual questions, and qualitative data, based on interviews of students solving Amp\`ere's law problems. We find that some students struggle to connect the current enclosed by an Amp\`erian loop to the properties of the magnetic field while some students do not use information about the magnetic field to help them solve Amp\`ere's law problems. In this paper, we show how these observations may be interpreted as evidence that some students do not see the integral in Amp\`ere's law as representing a sum and that some students do not use accessible information about the magnetic field as they attempt to solve Amp\`ere's law problems. This work extends previous studies into students' difficulties with Amp\`ere's law and provides possible guidance for instruction.
Courtiers of the New Empire

In an article that appeared in the New York Times in July 2005, Michael Wines bemoaned the fact that Zimbabwe's African neighbors were following a hands-off approach as the country fell into shambl...
Sudden death in children and adolescents

This article focuses on sudden unexpected cardiac death (SCD) in children and adolescents. The authors discuss the epidemiology of SCD in children and adolescents, its incidence and etiologies, and strategies for prevention. Because most of the episodes of SCD or sudden cardiac arrest in children and adolescents occur in asymptomatic individuals unknown to have an underlying abnormality before their "event," the issues in this article primarily focus on this group of individuals.
Gender and race matching preferences for HIV post-test counselling in an African-American sample.

Abstract This study tested whether having racially and gender-matched counsellors for HIV Post-test counselling were preferred. In the NIDA-funded EachOneTeachOne study, 115 African American respondents (19–68) were asked would they rather talk to someone of the same sex and race. Forty-three percent of the counsellor-respondent pairs were race concordant, and 58% were gender concordant. Chi-square statistics examined effects of gender, race and match. Out of those who desired a gender-match, 89% were men compared to 11% of women. Only 9% of African-Americans reported that they would feel more comfortable talking to an African-American counsellor. The sample size dropped due to non-response of the matching reference questions. Among the 39 race-counsellor concordant respondents (n=98), 23% expressed a preference for a race matched counsellor while no one with a race discordant counsellor expressed such a preference. Among the 56 respondents with a gender concordant counsellor (n=102), 27% said they would ...
Brain volumetric and microstructural correlates of executive and motor performance in aged rhesus monkeys

The aged rhesus macaque exhibits brain atrophy and behavioral deficits similar to normal aging in humans. Here we studied the association between cognitive and motor performance and anatomic and microstructural brain integrity measured with 3T magnetic resonance imaging in aged monkeys. About half of these animals were maintained on moderate calorie restriction (CR), the only intervention shown to delay the aging process in lower animals. T1-weighted anatomic and diffusion tensor images were used to obtain gray matter (GM) volume and fractional anisotropy (FA) and mean diffusivity (MD), respectively. We tested the extent to which brain health indexed by GM volume, FA, and MD were related to executive and motor function, and determined the effect of the dietary intervention on this relationship. We hypothesized that fewer errors on the executive function test and faster motor response times would be correlated with higher volume, higher FA, and lower MD in frontal areas that mediate executive function, and in motor, premotor, subcortical, and cerebellar areas underlying goal-directed motor behaviors. Higher error percentage on a cognitive conceptual shift task was significantly associated with lower GM volume in frontal and parietal cortices, and lower FA in major association fiber bundles. Similarly, slower performance time on the motor task was significantly correlated with lower volumetric measures in cortical, subcortical, and cerebellar areas and decreased FA in several major association fiber bundles. Notably, performance during the acquisition phase of the hardest level of the motor task was significantly associated with anterior mesial temporal lobe volume. Finally, these brain-behavior correlations for the motor task were attenuated in CR animals compared to controls, indicating a potential protective effect of the dietary intervention.
Advanced chronic obstructive pulmonary disease is associated with high levels of high-density lipoprotein cholesterol.

Background Chronic obstructive pulmonary disease (COPD) is an inflammatory systemic disease associated with numerous extrapulmonary manifestations. Amongst these is an increased risk for cardiovascular disease. The mechanisms for this association remain unclear. We sought to examine lipid trends in a well-characterized cohort of patients with severe COPD. Methods We conducted a retrospective prospective analysis of 126 consecutive individuals evaluated for lung transplantation with a diagnosis of COPD in whom lipid values were available. Observed lipid values were compared with a reference population without severe COPD. Results Compared with the reference population, mean low-density lipoprotein cholesterol (LDL-C) levels were slightly reduced at 108 ± 44 vs 117 ± 29.5 mg/dl ( p = 0.02) in men but were no different in women. Mean high-density lipoprotein cholesterol (HDL-C) levels were significantly elevated at 62 ± 24 vs 45 ± 12 mg/dl ( p p Conclusions Severe COPD is associated with increased levels of HDL-C, which is partially attributable to oral steroid use. HDL-C in this population is not associated with reduced risk of angiographically proven coronary artery disease.
Replacing Recalls with Interlibrary Loan: The University of Houston's QuickLoan Service

In August 2010, the M.D. Anderson Library at the University of Houston stopped recalling books. Patron complaints prompted Information and Access Services staff to reexamine the recalls process. In order to provide better customer service, recalls were eliminated in favor of Interlibrary Loans. This new service was called “QuickLoan.” Modifications were made to the OPAC so that the catalog record for a checked-out item would prominently display a button labeled “QuickLoan.” Patrons can press this button, and an ILL request form is prepopulated. In its first year, QuickLoan has seen increasing usage and has been received favorably by library patrons.
Mechanical Engineering Design Complexity Metrics: Size, Coupling, and Solvability

Developing objective measures for evaluating and measuring the complexity of design would facilitate (1) empirical studies that require the use of equivalent but different design problems, (2) the development of design curriculums, and (3) the comparison of computer aided design automation tools. This paper surveys and evaluates different approaches to defining complexity in design for the design problem, process, and product. Three fundamental aspects to complexity are identified, size, coupling, and solvability, and expanded with respect to the three elements of design, problem, process, and product. Alternative methods for measuring these characteristics of the design are based on computational, information, and traditional design views of complexity. A method of measuring size as it relates to complexity is proposed for measuring the information content of design. A second method is proposed for decomposing a graph-based representation of design that provides a measure of the interconnectedness as it relates to complexity. Finally, two methods are proposed for determining the solvability complexity of design based on the effort involved and the degree of freedom of design. These measures are developed specifically for parametric and geometric problems as found in the embodiment design, but these principles may be applied beyond this.
Cohesion and Coherence Strategies in Paragraph-Length and Extended Discourse in Japanese Oral Proficiency Interviews

Abstract: This study focused on Japanese linguistic features that contribute to producing the paragraph-length and extended connected discourse that is expected at the Advanced and Superior levels in ACTFL oral proficiency interviews (OPIs). From 15 Japanese OPIs at the Intermediate-High through Superior levels, 3,062 predicates were identified. Frequent use of embedded syntactic constructions, such as sentence modifiers and embedded interrogative and quotative constructions (˜(t)te iu), contributed to the integration of more predicates, resulting in extended discourse at the Superior level. To link clauses, gerunds and adversative clausal particles were more prevalent than sentence-initial connectives. Adversative clausal particles and quotative constructions played an important role in signaling the meaning of the utterance in relation to the entire discourse. A qualitative analysis revealed that appropriate use of cohesive and coherence devices affected the degree of cohesiveness and coherence of discourse. The implications for Japanese language pedagogy and OPI are significant.
Subacromial corticosteroid injection for poststroke shoulder pain: an exploratory prospective case series.

Abstract Chae J, Jedlicka L. Subacromial corticosteroid injection for poststroke shoulder pain: an exploratory prospective case series. Objective To assess the effectiveness of subacromial corticosteroid injections for poststroke shoulder pain. Design Exploratory, prospective case series. Setting Ambulatory setting, university-affiliated hospital. Participants Stroke survivors (N=10) with pain in the hemiparetic shoulder. Intervention Consecutive stroke survivors with evidence of supraspinatus impingement, supraspinatus tendonitis, or subacromial bursitis received subacromial corticosteroid injections. Main Outcome Measures The primary outcome measure was the Brief Pain Inventory (BPI) question 12 (BPI 12), which assesses "worst pain" in the previous 7 days. Secondary measures included BPI question 15, which assesses present pain and BPI question 23 (BPI 23), which assesses pain interference with 7 daily activities. Outcomes were assessed at baseline, weekly for the first 4 weeks and then at 8 and 12 weeks postinjection. Results Repeated measure analysis of variance revealed significant within group time effect for BPI 12 (F=7.7, P P =.009), sleep (F=3.9, P =.003), and enjoyment of life (F=2.3, P =.044) domains of BPI 23. Conclusions Subacromial corticosteroid injection is associated with significant reduction in poststroke shoulder pain in patients with evidence of supraspinatus impingement, supraspinatus tendonitis, or subacromial bursitis. However, there is a gradual loss of effect with time. Controlled trials are needed to show a cause and effect relationship.
What Can We Learn About Cancer Therapy from Single Cell Tracking

Small numbers of treatment-resistant cancer cells often persist after apparently successful therapy and eventually return to cause disease relapse. We are developing intravital microscopy techniques to uncover the habitat sheltering these residual cancer cells.
The Healthy Weight Commitment Foundation pledge: calories sold from U.S. consumer packaged goods, 2007-2012.

Corporate voluntary pledges to improve the health of Americans have not been held to either explicit measurable outcomes or a framework for independent evaluation. The Healthy Weight Commitment Foundation (HWCF), whose members include 16 of the nation’s leading consumer packaged goods (CPG) food and beverage manufacturers, voluntarily pledged to collectively sell 1 trillion fewer calories in the U.S. marketplace by 2012 (against a 2007 baseline), and sell 1.5 trillion fewer calories by 2015. This paper presents the findings of an independent evaluation of the 2012 HWCF marketplace pledge, conducted in 2013. The 16 HWCF companies collectively sold approximately 6.4 trillion fewer calories (–10.6%) in 2012 than in the baseline year of 2007. Taking into account population changes over the 5-year period of 2007–2012, CPG caloric sales from brands included in the HWCF pledge declined by an average of 78 kcal/capita/day. CPG caloric sales from non-HWCF national brands during the same period declined by 11 kcal/capita/day, and there were similar declines in calories from private label products. Thus, the total reduction in CPG caloric sales between 2007 and 2012 was 99 kcal/capita/day. This independent evaluation is the first to evaluate food industry compliance with its calorie reduction pledges and to assess how sales from the CPG food and beverage sector are changing. An accompanying paper investigates the extent to which the HWCF pledge affected household-level changes in CPG calories purchased, controlling for important economic and sociodemographic factors affecting household food purchases over this period.
Unpacking Public Attitudes to the Police: Contrasting Perceptions of Misconduct with Traditional Measures of Satisfaction

Much research on public attitudes to the police in the United States has focused on perceptions of police effectiveness and responsiveness rather than police misconduct. This research has also tended to rely primarily on experiences of direct personal contacts with police and, more recently, neighbourhood to explain demographic differences in public opinion. This article uses data from a five-neighbourhood community survey to extend this focus. It tests four hypotheses: (1) public attitudes about police misconduct are distinct from their attitudes about police effectiveness and responsiveness; (2) determinants of attitudes about police misconduct are different from those relating to police effectiveness and responsiveness; (3) negative experiences of police among friends, family and associates impact on personal attitudes to the police; (4) attitudes toward the police are affected by the character of news coverage to which members of the public are exposed. Using principal components analysis and ANCOVA m...
Expert versus Machine: A Comparison of Two Suitability Models for Emergency Helicopter Landing Areas in Yosemite National Park

Landing a rescue helicopter in a wilderness environment, such as Yosemite National Park, requires suitable areas that are flat, devoid of tree canopy, and not within close proximity to other hazards. The objective of this study was to identify helicopter landing areas that are most likely to exist based on available geographic data using two GIScience methods. The first approach produced an expert model that was derived from predefined feature constraints based on existing knowledge of helicopter landing area requirements (weighted overlay algorithm). The second model is derived using a machine learning technique (maximum entropy algorithm, Maxent) that derives feature constraints from existing presence-only points; that is, geographic one-class data. Both models yielded similar output and successfully classified test coordinates, but Maxent was more efficient and required no user-defined weighting that is typically subject to human bias or disagreement. The pros and cons of each approach are discussed an...
The Role of Catecholamines in the Regulation of Pituitary Luteinizing Hormone and Follicle-Stimulating Hormone Secretion

I. Introduction We have followed an arduous and often tortuous route to reach our current understanding of the physiological role of catecholamines (CAs) in the regulation of gonadotropin secretion. More often than not, the vast amounts of confusing literature on this subject have bewildered the novice and discouraged the faint of heart and, as such, research into the complexities of this system have waxed and waned over the 32 or more years since CAs first were implicated as regulators of gonadotropin secretion. Much of this confusion was due to: 1) lack of adequate methodology to measure CA secretion; 2) the use of complex and at times unusual experimental animal preparations and paradigms; 3) an inadequate understanding of the neuroanatomy of CA pathways in the brain; and 4) the use of many drugs which lack the specificity required to delineate the interplay that exists between CAs and the secretion of gonadotropic hormones. This is not to say that we now have deciphered the many complex central nervou...
The linear nearest neighbour statistic

Let X1,..., Xn represent a sample of points on a line of length L whose left endpoint is 0, and let X(1) < ... < X(n) denote the order statistics of the X's. The problem of testing the hypothesis that the points placed along the line arise as a random sample from a uniform distribution has been of considerable interest for some time. Many of the tests are based on the spacings between the ordered points, that is on, D1 = X(1), Di = X(i)X(i1) (i = 2, ...,n) and Dn+1 = L-X(n) (Pyke, 1965). The present paper considers a slight modification of a test of randomness of points on a line which was introduced by Pinder & Witherick (1973) and which is also based on spacings. The test statistic, called the linear nearest neighbour statistic, is the onedimensional analogue of the areal two-dimensional nearest neighbour statistic proposed by Clark & Evans (1954), which has found considerable use in the biological sciences for assessing the randomness of points in two dimensions (Pielou, 1969, Chapter 10). The linear nearest neighbour statistic was proposed to study the clustering, dispersion, i.e. equal spacing, or randomness of points; for example, stores, towns, housing sites, along natural or manmade 'lines' such as streets and waterways. Various uses of the statistic in geography are given by Pinder & Witherick (1973), and an archaeological application is discussed by Stark & Young (1981). Thus far, exact and approximate distributions of the statistic are unknown. To define the linear nearest neighbour statistic let Mi be the distance between X(i) and the point nearest it, that is Mi = min (Di, Di+ ) (i = 1, ..., n). When L is known, the linear nearest neighbour statistic is n M= ZMi/L.
Statistics among the Liberal Arts

Abstract The liberal arts are usually understood to be general and flexible modes of reasoning. By this definition, statistics qualifies as a liberal art, and it is important to the health of the discipline that it be recognized as such. The “philosophical” tradition of the liberal arts that is now dominant has alternated with an “oratorical” tradition that also gives insight, as do ideas of “evolutionary psychology.” This paper considers how understanding statistics as a liberal art influences our appreciation of the discipline and especially our teaching of beginners.
Experimental measurements and noise analysis of a cryogenic radiometer

A cryogenic radiometer device, intended for use as part of an electrical-substitution radiometer, was measured at low temperature. The device consists of a receiver cavity mechanically and thermally connected to a temperature-controlled stage through a thin-walled polyimide tube which serves as a weak thermal link. With the temperature difference between the receiver and the stage measured in millikelvin and the electrical power measured in picowatts, the measured responsivity was 4700 K/mW and the measured thermal time constant was 14 s at a stage temperature of 1.885 K. Noise analysis in terms of Noise Equivalent Power (NEP) was used to quantify the various fundamental and technical noise contributions, including phonon noise and Johnson-Nyquist noise. The noise analysis clarifies the path toward a cryogenic radiometer with a noise floor limited by fundamental phonon noise, where the magnitude of the phonon NEP is 6.5 fW / Hz for the measured experimental parameters.
Business-to-Business Negotiations: The Role of Relativism, Deceit, and Opportunism

Purpose: Studies examining the impact of relativism and deceitful tendencies on unethical negotiation tactics have yielded inconsistent results; some studies report a positive relationship, some negative, while some others report a nonexistent relationship between these constructs. These inconsistencies suggest that there may be intervening variables mediating the effects of these factors on unethical negotiation tactics. We propose that opportunism plays an important role in determining the effects of these two antecedents on business managers' perceptions of unethical negotiation tactics. Method: An Internet-based survey was administered to a sample of managers at U.S. firms engaged in business-to-business marketing. Structural equation modeling techniques were used to evaluate the mediating role of opportunism between deceitful tendencies and relativism on questionable negotiation tactics. Findings: The analysis supports the hypothesized role of opportunism as a mediating variable. Opportunism was foun...
P3.362 Microbicide Use During Pregnancy: Acceptability For Prevention/Treatment and the Role of Partners

Objectives To explore pregnant women’s acceptance of microbicides for reproductive tract infections (RTIs). Methods To date, we have analysed interview transcripts of 15 women in their third trimester who participated in a qualitative study on microbicide acceptability for treatment and prevention of bacterial vaginosis (BV) and role of partners in decision-making regarding product use. Interviews were coded for relevant themes. Women (mean age = 25.5; range = 21–30) were recruited from a clinic serving an inner-city minority population. Results While few women reported BV history, most did not spontaneously provide specific BV knowledge. Most participants strongly endorsed treatment of any infection during pregnancy, however, responses to prevention ranged from ambivalence to strong support. Many women would make a decision based on perception of risk/benefit to the baby. Other themes included: (1) side effects; (2) effectiveness; (3) perceived personal risk for RTI; (4) general investment in personal health. Some women seemed to have difficulty understanding prevention, and many felt greater clarity about microbicide use for treatment. Many viewed barriers (i.e., leakage, remembering, inserting) as easy to manage since they already used panty-liners, thought product use could be incorporated into daily routines and thought partners could help. Treating an active infection trumped barriers; this was less clear for prevention use. The decision regarding product use was viewed as belonging to the woman; partners were perceived as supporting what is best for the baby. Conclusions Women in a NYC pre-natal clinic enthusiastically support the use of microbicides for RTIs. In order for this enthusiasm to lead to adoption, women need to be well-informed about the RTI, its consequences and risk/benefit of use. As barriers are likely to be greater in the absence of a current infection, a greater understanding and emphasis of the need versus the risk will be required for prevention use.
Lack of stimulation by high amphetamine doses following a low dose of spiperone

Abstract The locomotor stimulant and stereotypic effects of amphetamine were investigated in rats pretreatment with the specific dopaminergic blocker spiperone (0.25 mg/kg). Amphetamine doses from 8.0 to 64.0 mg/kg failed to stimulate behavior significantly and consistently after spiperone treatment. These results suggest the possibility of non-competitive antagonism by spiperone at dopaminergic synapses.
Predominant use of a Vα gene segment in mouse T-cell receptors for cytochrome c

The T-cell receptor is a cell surface heterodimer consisting of an α and a β chain that binds foreign antigen in the context of a cell surface molecule encoded by the major histocompatibility complex (MHC), thus restricting the T-cell response to the surface of antigen presenting cells1–4. The variable (V) domain of the receptor binds antigen and MHC molecules and is composed of distinct regions encoded by separate gene elements—variable (Vα and Vβ), diversity (Dβ) and joining (Jα and Jβ)—rearranged and joined during T-cell differentiation to generate contiguous Vα and Vβ genes5–11. T-helper cells, which facilitate T and B cell responses, bind antigen in the context of a class II MHC molecule. The helper T-cell response to cytochrome c in mice is a well-defined model for studying the T-cell response to restricted antigen and MHC determinants. Only mice expressing certain class II molecules can respond to this antigen (Ekα Ekβ, Ekα Ebβ, Evα Evβ and Ekα Esβ)12–14. Most T cells appear to recognize the C-terminal peptide of cytochrome c (residues 81–104 in pigeon cytochrome c)15–18. We have raised helper T cells to pigeon cytochrome c or its C-terminal peptide analogues in four different MHC congenic strains of mice encoding each of the four responding class II molecules. We have isolated and sequenced seven Vα genes and six Vβ genes and analysed seven additional helper T cells by Northern blot to compare the structure of the Vα and Vβ gene segments with their antigen and MHC specificities. We have added five examples taken from the literature19–22. These data show that a single Vα gene segment is responsible for a large part of the response of mice to cytochrome c but there is no simple correlation of MHC restriction with gene segment use.
Confchem conference on case-based studies in chemical education: The future of case study teaching in science

This communication raises two important issues. First, it describes the history of case-based teaching and its adoption by scientists, most of whom are biologists and asks the question, “If the method is so promising, why aren’t more chemists and other physical scientists using the approach?” Second, the various styles of case study teaching are compared using the well-known “Cone of Learning” as a standard. The methods using the greatest student interaction, such as problem-based learning, are proposed to produce the greatest learning.
Electron-electron interaction effects on Peierls dimerization in a half-filled band

A novel real-space approach to dimerization in a half-filled band is developed to investigate effects of electron-electron interactions on the Peierls instability. Dimerization is shown to be a result of imperfect resonance between pairs of electron configurations related to each other by a mirror-plane symmetry passing through the longest diagonal of the infinite ring, and the kinetic- and potential-energy contributions to the barrier to resonance are identified separately. The effects of including the on-site, nearest-neighbor, and next-nearest-neighbor interactions are investigated, and in each case it is shown that the enhancement or reduction in dimerization can be predicted from elementary physical arguments. These predictions are then substantiated by exact numerical calculations on a ten-site ring, and finite-size effects are shown to be small. The principal results that are obtained are the following: (i) The on-site correlation $U$ strongly enhances the dimerization, the enhancement being strongest for $U\ensuremath{\sim}4{t}_{0}$, where $4{t}_{0}$ is the bandwidth of the uniform chain; (ii) the nearest-neighbor interaction ${V}_{1}$ further enhances the dimerization until ${V}_{1}\ensuremath{\lesssim}\frac{1}{2}U$, while ${V}_{1}g\frac{1}{2}U$ favors a uniform chain with a different broken-symmetry ground state, an on-site charge-density wave; (iii) for ${V}_{1}\ensuremath{\lesssim}\frac{1}{2}U$, the second-neighbor interaction ${V}_{2}$ reduces the dimerization slightly, although the dimerization is still stronger than that with an effective nearest-neighbor interaction ${V}_{1}\ensuremath{-}{V}_{2}$; (iv) for ${V}_{1}g\frac{1}{2}U$, ${V}_{2}$ destroys the on-site charge-density wave and the ground state is strongly dimerized again. The complete Parisier-Parr-Pople (PPP) Hamiltonian is discussed, and it is pointed out that the above results, together with the excited-state orderings in the PPP Hamiltonian, strongly indicate that the ground state of the PPP Hamiltonian is the dimerized state. The excited-state orderings in finite polyenes, spin-density distributions in polyacetylene, and our theoretical results all indicate then that explicit inclusion of Coulomb interactions may be necessary for an accurate description of the ground and excited states in polyacetylene.
Preseasonal IgE ragweed antibody level as a predictor of response to therapy of ragweed hay fever with intranasal cromolyn sodium solution

Abstract Intranasal administration of a 4% solution of cromolyn sodium for the treatment of ragweed hay fever was tested in an 8-week double-blind matched-pair study involving 66 patients. Patients on active drug received 5.2 mg into each nostril 6 times daily; control patients received a placebo spray. The treated group showed a significant reduction in mouth breathing (p
Single-dose pharmacodynamics of diazepam and pentobarbital in substance abusers

The likelihood that a given drug will be misused is related to its ability to alter mood, feeling, thinking, and perception in a manner that is liked by substance abusers. The subjective and behavioral effects of diazepam (10, 20, and 40 mg), pentobarbital (120 and 240 mg as a positive control), and placebo (negative control), were evaluated in 12 subjects with histories of substance abuse by use of a double-blind, Latin square crossover study design. Drug administration was separated by a minimum of 3 days. Pharmacodynamic measures included subjective (euphoria, subject liking, sedation, and symptoms) and behavioral (signs and observed liking) responses. The time course and profile of subjective and behavioral responses were similar for diazepam and pentobarbital. Valid relative potency estimates for the pharmacodynamic measures indicated that diazepam is approximately 10 times as potent as pentobarbital. The study indicates that the reinforcing effects of diazepam are similar to pentobarbital in substance abusers. Clinical Pharmacology and Therapeutics (1993) 54, 645–653; doi:10.1038/clpt.1993.202
Generalized conjugate-gradient methods for the Navier-Stokes equations

A generalized conjugate-gradient method is used to solve the two-dimensional, compressible Navier-Stokes equations of fluid flow. The equations are discretized with an implicit, upwind finite-volume formulation. Preconditioning techniques are incorporated into the new solver to accelerate convergence of the overall iterative method. The superiority of the new solver is demonstrated by comparisons with a conventional line Gauss-Siedel Relaxation solver. Computational test results for transonic flow (trailing edge flow in a transonic turbine cascade) and hypersonic flow (M = 6.0 shock-on-shock phenoena on a cylindrical leading edge) are presented. When applied to the transonic cascade case, the new solver is 4.4 times faster in terms of number of iterations and 3.1 times faster in terms of CPU time than the Relaxation solver. For the hypersonic shock case, the new solver is 3.0 times faster in terms of number of iterations and 2.2 times faster in terms of CPU time than the Relaxation solver.
Human Cytomegalovirus Glycoprotein gO Complexes with gH/gL, Promoting Interference with Viral Entry into Human Fibroblasts but Not Entry into Epithelial Cells

A complex of five human cytomegalovirus virus (HCMV) proteins, gH, gL, UL128, UL130, and UL131 (gH/gL/UL128-131), is essential for virus entry into epithelial cells. We previously showed that gH/gL/UL128-131 expressed in epithelial cells interferes with subsequent HCMV entry into cells. There was no interference with only gH/gL or gB. We concluded that the expression of gH/gL/UL128-131 causes a mislocalization or downregulation of epithelial cell proteins that HCMV requires for entry. In contrast, gH/gL/UL128-131 expression in fibroblasts did not produce interference, suggesting a different mechanism for entry. Here, we show that the coexpression of another HCMV glycoprotein, gO, with gH/gL in human fibroblasts interferes with HCMV entry into fibroblasts but not epithelial cells. However, the coexpression of gO with gH/gL did not increase the cell surface expression level of gH/gL and did not enhance cell-cell fusion, a process that depends upon cell surface gH/gL. Instead, gO promoted the export of gH/gL from the endoplasmic reticulum (ER) and the accumulation of gH/gL in the trans-Golgi network. Thus, interference with gH/gL or gH/gL/gO, i.e., the mislocalization or blocking of entry mediators, occurs in cytoplasmic membranes and not in cell surface membranes of fibroblasts. Together, the results provide additional support for our hypotheses that epithelial cells express putative gH/gL/UL128-1331 receptors important for HCMV entry and that fibroblasts express distinct gH/gL receptors.
Postfreeze viability of human renal epithelial carcinoma cells related to phase transformations in ternary solutions.

Abstract The postfreeze viability of human renal epithelial carcinoma cells frozen in solutions based on a complex physiologic support medium to which additions of NaCl and a cryoprotective agent, either glycerol or dimethyl sulfoxide (DMSO) were made, have been determined by a dye exclusion technique. The support medium consisted of either Eagle's Minimum Essential Medium with Hanks' salts added (MEM) or this same medium supplemented with 20 vol% heat-inactivated fetal calf serum (MEM + FCS). Glycerol was found to be an ineffective cryoprotective agent for these cells, while DMSO was highly effective. Addition of NaCl along with the DMSO further improved the viability of cells frozen at −196 °C. Freezing and thawing rates were found to be important with a slow freezing rate, 2.5 °C/min, and a rapid thawing rate, 240°C/min, yielding the best results. Maximum viability occurred in solutions containing 80 to 95 wt.% (MEM + FCS) with the balance being DMSO and NaCl in the weight ratio of 9:1. In addition to primary ice formation, two nonequilibrium glassy phases were observed during DTA studies of these solutions (10). The exintence of these vitreous states reduces the chances thet cells will be exposed to hypertonic concentrations of salt in the extracellur fluids during freezing-out of primary ice.