cssi/SciSciGPT-SciSciNet huggingface dataset:
Notch and EGFR pathway interaction regulates neural stem cell number and self-renewal

Specialized cellular microenvironments, or 'niches', modulate stem cell properties, including cell number, self-renewal and fate decisions. In the adult brain, niches that maintain a source of neural stem cells (NSCs) and neural progenitor cells (NPCs) are the subventricular zone (SVZ) of the lateral ventricle and the dentate gyrus of the hippocampus. The size of the NSC population of the SVZ at any time is the result of several ongoing processes, including self-renewal, cell differentiation, and cell death. Maintaining the balance between NSCs and NPCs in the SVZ niche is critical to supply the brain with specific neural populations, both under normal conditions or after injury. A fundamental question relevant to both normal development and to cell-based repair strategies in the central nervous system is how the balance of different NSC and NPC populations is maintained in the niche. EGFR (epidermal growth factor receptor) and Notch signalling pathways have fundamental roles during development of multicellular organisms. In Drosophila and in Caenorhabditis elegans these pathways may have either cooperative or antagonistic functions. In the SVZ, Notch regulates NSC identity and self-renewal, whereas EGFR specifically affects NPC proliferation and migration. This suggests that interplay of these two pathways may maintain the balance between NSC and NPC numbers. Here we show that functional cell-cell interaction between NPCs and NSCs through EGFR and Notch signalling has a crucial role in maintaining the balance between these cell populations in the SVZ. Enhanced EGFR signalling in vivo results in the expansion of the NPC pool, and reduces NSC number and self-renewal. This occurs through a non-cell-autonomous mechanism involving EGFR-mediated regulation of Notch signalling. Our findings define a novel interaction between EGFR and Notch pathways in the adult SVZ, and thus provide a mechanism for NSC and NPC pool maintenance.
High-temperature redox behavior of doped SrTiO3 and LaCrO3

Abstract The stability of high-temperature fuel cell electrodes to their ambient environment is important for the long-term reliability of fuel cells. In this report the behavior of oxide electrode materials as a function of oxygen activity and temperature is considered. Models for the oxidation-reduction behavior of both p - and n -type oxides are presented. These models take into account the absorption and evolution of oxygen which take place as oxygen activity is varied. The resulting instability in electrical conductivity is explained as a consequence of changes in carrier concentration due to variability in ionic defect concentration. The proposed models are applied to acceptor-doped LaCrO 3 and donor-doped SrTiO 3 . It is shown that the models explain the experimental data well and as a consequence diagrams can be made which show the regions of oxygen activity and temperature for which stability of electrical conductivity and defect structure might be expected.
On-chip spike clustering & classification using self organizing map for neural recording implants

Spike sorting plays a vital role in recording neural signals using microelectrode arrays for neuroscience research. The bandwidth bottleneck is greatly eased for data transmission of hundreds of channels in neuroprosthetic application through on-chip spike sorting. Our previous work on feature extraction algorithm called Zero-Crossing Features (ZCF) shows good performance for data reduction and spike classification while requiring minimal hardware resources. In this paper, a new spike clustering & classification method based on ZCF feature extraction is presented. The method is shown to perform well in identifying the number of neurons in a spike channel and classifying spikes into correct neurons. An implant-compatible VLSI hardware architecture to cluster and classify spikes in the ZCF feature space is also presented.
California Sea Lions Breeding at Año Nuevo Island, California

L'extension vers le nord des sites de reproduction de Zalophus californicus pourrait resulter d'un accroissement continu de population de Californie et du Mexique toute entiere au cours de ce siecle
Quantitation and subcellular localization of proliferating cell nuclear antigen (PCNA/cyclin) in oocytes and eggs of Xenopus laevis.

Abstract Proliferating cell nuclear antigen (PCNA/cyclin) is a 36-kDa polypeptide present in the nuclei of mitotically active cells. It is known to be involved in DNA replication through an association with DNA polymerase δ. We examined the total content as well as the subcellular distribution of PCNA in the oocyte and the egg of Xenopus laevis by employing immunocytological staining and immunoblot analysis. While oocytes are not capable of replicating chromosomes, PCNA is abundant in the nucleus (about 65 ng per nucleus). The oocyte cytoplasm, on the other hand, does not contain a significant quantity of this protein. The amount of total PCNA does not change appreciably during oocyte maturation and the subsequent stages of egg cleavage. Thus, PCNA belongs to a class of proteins which are stockpiled during oogenesis in order to be utilized later for early embryogenesis.
Strategic Flirting and the Emotional Tab of Exotic Dancing

ABSTRACT The paper uses the concept strategic flirting, an aspect of emotional labor, to challenge the dichotomous view that sex work is either exploitative or empowering for exotic dancers. The findings suggest a more nuanced understanding of the advantages of sexual power and expenditures of emotional labor. Data were gleaned from interviews with 112 female dancers in several cities. Data from dancers indicate significant support for both the sexual radical/libertarian view—that she is the dominant party in the sexual transaction—and the radical feminist view that exotic dancing has detrimental consequences. Both the feminist and sociology of emotions literatures are explored for applications to the dancers' work.
Practical equation of state and activity coefficient models based on the exp-6 fluid

Dodd L.R. and Sandler S.I., 1991. Practical equation of state and activity coefficient models based on the exp-6 fluid. Fluid Phase Equilibria, 69: 99-139. In this paper we test a partition function model recently developed for the exp-6 fluid mixture against experimental data for real fluids. This model leads to a unique size and density-dependent mixing rule providing non-quadratic density-dependence which satisfies the low-density and pure fluid boundary conditions. The equation of state calculations with this model gave good results, especially for highly asymmetric systems. Applications of a similar mixing rule to cubic engineering equations of state for real fluids yielded better predictions than the van der Waals one-fluid mixing rule. However, except in the near critical region, any clear advantage of the new density-dependent mixing rule for real fluids is lost when adjustable parameters are added. We also show that an activity coefficient model based on this exp-6 model leads to good correlations for low pressure vapor-liquid equilibria of both simple and very complex mixtures, indeed mixtures that could not easily be described by other models with the same number of parameters.
Optimizing chain bridging in complex block copolymers

Recent experiments by Ryu, Hermel, and co-workers have demonstrated a correlation between the presence of bridging A-blocks and practical toughness in themoplastic ABABA pentablock copolymers. Building on this observation, we develop a computational tool for evaluating average bridging fractions of internal blocks in complex block copolymers and apply the tool to the optimization of bridging fractions in mesophase structures computed with self-consistent-field theory. We identify optimal molecular designs for ABABA pentablock copolymers that could provide the useful combination of high modulus and high toughness. Further applications of the approach to property screening in complex mesophases formed by ABC and ABCA block copolymers are discussed.
Interpretation of Pulmonary Function Test: Issues and Controversies

Pulmonary function testing (PFT) serves many purposes in clinical practice, and in contrast to other laboratory measures, PFT results are often provided with a clinical interpretation. PFT interpretation depends on the clinical context, and multiple challenges influence PFT interpretation. Overall, the goal of PFT interpretation is to distinguish normal from abnormal, and this is affected by the selection of reference standards, as well as the arbitrary albeit not necessarily irrational choice of cut-off values. Controversies regarding PFT analysis may lead to important differences in interpretation. In this article, issues associated with the selection of reference standards are discussed, followed by a review of the controversies related to PFT interpretation in the diagnosis of obstructive ventilatory defect, restrictive ventilatory defect, gas transfer defect, and flow-volume loop abnormalities. Given the challenges facing PFT interpretation, no single interpretative algorithm is sufficient; rather, PFT interpretation requires a comprehensive approach including consideration of the clinical context, laboratory methodology, and reference standards and an understanding of the consequences of a normal or abnormal designation.
Restenosis after carotid stent placement in patients with previous neck irradiation or endarterectomy.

Purpose Placement of a carotid artery stent (CAS) is an appealing treatment option for patients who have undergone neck irradiation or endarterectomy. Early outcomes and restenosis rates in these patients were analyzed and compared with those in de novo lesions. Materials and Methods Single-center, retrospective review of 269 CAS procedures that used cerebral embolic protection and nitinol stents was conducted from May 2001 through July 2006. In this cohort, 66 procedures were performed in patients with a history of external-beam neck irradiation ( n = 26) or carotid endarterectomy (CEA; n = 40), designated as the "hostile neck" group. Mean follow-up was 16 months. Results The 30-day event rate for the entire group included major ipsilateral stroke (1.1%), minor posterior stroke (1.1%), and myocardial death (0.4%); none occurred in the hostile neck group. The rate of restenosis or occlusion for all 269 arteries was 2.6%. There was no significant difference in restenosis or occlusion rates between de novo lesions (2.0%, four of 203) and the hostile neck group (4.5%, three of 66; P = .17). Repeat angioplasty with or without stent implantation was employed for all patients with restenosis and resulted in no periprocedural stroke, death, or subsequent restenosis. Conclusions Periprocedural outcomes of CAS procedures are similar in de novo lesions as in patients with a history of neck irradiation or CEA. Importantly, restenosis requiring repeat intervention remains uncommon, and its incidence is comparable between groups.
Screening of symptomatic women for ovarian cancer

e137 www.thelancet.com/oncology Vol 13 April 2012 where the tubes and ovaries are minimally involved, as described by Gilbert and colleagues. First, the potential usefulness of preemptive salpingectomy needs to be determined, as this practice is being widely considered as an alternative to a risk-reducing complete salpingooophorectomy. Second, we need by exclusion to identify the percentage of tumours that cannot be traced to either the tube or the ovary. Both these questions are important to thousands of women who for various reasons will choose salpingectomy but who might have a hidden threat from a remote malignant source in the pelvis. By application of this simple protocol to every fallopian-tube sample, we will be able to answer these questions and have an appropriately archived tissue source to interrogate further if malignant disease emerges after a normal salpingectomy.
Attribute expression of fault-controlled karst — Fort Worth Basin, Texas: A tutorial

AbstractMuch of seismic interpretation is based on pattern recognition, such that experienced interpreters are able to extract subtle geologic features that a new interpreter may easily overlook. Seismic pattern recognition is based on the identification of changes in (1) amplitude, (2) phase, (3) frequency, (4) dip, (5) continuity, and (6) reflector configuration. Seismic attributes, which providing quantitative measures that can be subsequently used in risk analysis and data mining, partially automate the pattern recognition problem by extracting key statistical, geometric, or kinematic components of the 3D seismic volume. Early attribute analysis began with recognition of bright spots and quickly moved into the mapping of folds, faults, and channels. Although a novice interpreter may quickly recognize faults and channels on attribute time slices, karst terrains provide more complex patterns. We sought to instruct the attribute expression of a karst terrain in the western part of the Fort Worth Basin, T...
Solvable Nuclear War Models

This paper deals with an aggregated, two-sided war game, one of several designed to study the use of abstract models for strategic planning. A payoff function for the war game is defined making use of an assumption of increasing concern as a critical level of damage is approached. A very simple, one-weapon version of the central nuclear war game has an analytic solution, indicating the existence of a stable equilibrium point in pure strategies if each side has a nonnegligible counterforce capability.
Evolution of powerful extragalactic radio sources

Abstract Observations of complete flux density limited samples of powerful extragalactic radio sources by very-long-baseline interferometry enable us to study the evolution of these objects over the range of linear scales from 1 parsec to 15 kiloparsees (1 parsec = 3.09 x 10(18) cm). The observations are consistent with the unifying hypothesis that compact symmetric objects evolve into compact steep-spectrum doubles, which in turn evolve into large-scale Fanaroff-Riley class II objects. It is suggested that this is the primary evolutionary track of powerful extragalactic radio sources. In this case there must be significant luminosity evolution in these objects, but little velocity evolution, as they expand from 1 parsec to several hundred kiloparsecs in overall size.
Localization of spontaneously hyperactive B cells of NZB mice to a specific B cell subset

Abstract NZB mice produce numerous autoantibodies and have a subpopulation of B cells characterized by marked spontaneous hypersecretion of IgM. The latter trait is determined by autosomal genes, in F1 hybrids of NZB and normal strains. We tested the hypothesis that the hypersecreting B cells of NZB mice are contained within a specific subpopulation by examining (CBA/N X NZB)F1 hybrids. CBA/N mice have an X-linked recessive defect that results in the absence of a functionally distinct B cell subpopulation and impaired antibody responses. The hyperactivity of B cells, characteristic of the NZB parent, was transmitted to the F1 female, but was not expressed by the F1 male, which manifested the CBA/N B cell hyporesponsiveness. By contrast, the NZB xenotropic virus was expressed equally by both male and female F1 mice. We conclude that the NZB B cell abnormality resides within the B cell subpopulation affected by the CBA/N mutation.
Multi-wavelength simulations of atmospheric radiation from Io with a 3-D spherical-shell backward Monte Carlo radiative transfer model

Abstract Conflicting observations regarding the dominance of either sublimation or volcanism as the source of the atmosphere on Io and disparate reports on the extent of its spatial distribution and the absolute column abundance invite the development of detailed computational models capable of improving our understanding of Io’s unique atmospheric structure and origin. Improving upon previous models, Walker et al. (Walker, A.C., Gratiy, S.L., Levin, D.A., Goldstein, D.B., Varghese, P.L., Trafton, L.M., Moore, C.H., Stewart, B. [2009]. Icarus) developed a fully 3-D global rarefied gas dynamics model of Io’s atmosphere including both sublimation and volcanic sources of SO 2 gas. The fidelity of the model is tested by simulating remote observations at selected wavelength bands and comparing them to the corresponding astronomical observations of Io’s atmosphere. The simulations are performed with a new 3-D spherical-shell radiative transfer code utilizing a backward Monte Carlo method. We present: (1) simulations of the mid-infrared disk-integrated spectra of Io’s sunlit hemisphere at 19 μm, obtained with TEXES during 2001–2004; (2) simulations of disk-resolved images at Lyman- α obtained with the Hubble Space Telescope (HST), Space Telescope Imaging Spectrograph (STIS) during 1997–2001; and (3) disk-integrated simulations of emission line profiles in the millimeter wavelength range obtained with the IRAM-30 m telescope in October–November 1999. We found that the atmospheric model generally reproduces the longitudinal variation in band depth from the mid-infrared data; however, the best match is obtained when our simulation results are shifted ∼30° toward lower orbital longitudes. The simulations of Lyman- α images do not reproduce the mid-to-high latitude bright patches seen in the observations, suggesting that the model atmosphere sustains columns that are too high at those latitudes. The simulations of emission line profiles in the millimeter spectral region support the hypothesis that the atmospheric dynamics favorably explains the observed line widths, which are too wide to be formed by thermal Doppler broadening alone.
Statistical mechanics of lattice tubes

A system of lattice tubes which provides a simplified model for the pair correlation of a uniaxial ferromagnet and the loop-loop correlation of a lattice gauge theory is introduced and studied. The system is shown to exhibit a melting transition. Two distinct tube-roughening transitions are proposed. Ornstein-Zernike scaling of the pair correlation is established outside the critical regime. This scaling is used to determine the asymptotic behavior of the number of lattice tubes.
Site Characteristics as Predictors of Lonicera maackii in Second-Growth Forests of Central Kentucky, USA

ABSTRACT: Non-native invasive plants can negatively affect the abundance and survival of native plant species and alter ecosystem function. Amur honeysuckle (Lonicera maackii) is an invasive shrub that is an increasingly onerous problem for forest managers in eastern North America. We examined site-specific characteristics related to the presence and abundance of Amur honeysuckle, and other non-native invasive plants, in 15 second growth forests in central Kentucky. Individual remnants were characterized by: (1) frequency and cover of non-native invasive and native shrubs, (2) overstory tree basal area, (3) forest floor litter depth, (4) species composition of leaf litter, and (5) soil characteristics. Of the measured variables, the only statistically significant relationships we discovered were between Amur honeysuckle and characteristics of the forest floor. We found significant negative relationships between Amur honeysuckle presence and both forest floor litter depth (P = 0.01) and the percent of oak ...
The estimation of R 2 and adjusted R 2 in incomplete data sets using multiple imputation

The coefficient of determination, known also as the R 2, is a common measure in regression analysis. Many scientists use the R 2 and the adjusted R 2 on a regular basis. In most cases, the researchers treat the coefficient of determination as an index of ‘usefulness’ or ‘goodness of fit,’ and in some cases, they even treat it as a model selection tool. In cases in which the data is incomplete, most researchers and common statistical software will use complete case analysis in order to estimate the R 2, a procedure that might lead to biased results. In this paper, I introduce the use of multiple imputation for the estimation of R 2 and adjusted R 2 in incomplete data sets. I illustrate my methodology using a biomedical example.
[125I/127I]IodoHoechst 33342: Synthesis, DNA Binding, and Biodistribution

An iodinated analog of the DNA-minor-groove-binding agent Hoechst 33342 has been synthesized and evaluated for DNA binding and tumor targeting. The bis-benzimidazole ring system of the title compound was constructed from the piperazinyl terminus via a Pinner-type cyclization followed by oxidative cyclization of the diamine Schiff base. To synthesize radioiodoHoechst 33342, (trimethylstannyl)Hoechst 33342 was prepared by the same strategy and subjected to mild radioiododestannylation in the presence of lactoperoxidase. After purification by HPLC, the radiochemical was separated in carrier-free form with >85% radiochemical yield and >99% chemical and radiochemical purity. Fluorescence spectrometric analysis of the binding of iodoHoechst 33342 to calf thymus DNA gave an equilibrium association constant (Ka) of 2.57 × 107 M-1 comparable to the Ka value of Hoechst 33342. Fluorescence microscopy of viable V79 cells demonstrated that the iodinated dye stained the nuclei with avidity similar to that of the noniod...
Stochastic Motion by Mean Curvature

We prove the existence of a continuously time‐varying subset K(t) of R n such that its boundary ∂K(t), which is a hypersurface, has normal velocity formally equal to the (weighted) mean curvature plus a random driving force. This is the first result in such generality combining curvature motion and stochastic perturbations. Our result holds for any C 2 convex surface energy. The K(t) can have topological changes. The randomness is introduced by means of stochastic flows of diffeomorphisms generated by Brownian vector fields which are white in time but smooth in space. We work in the context of geometric measure theory, using sets of finite perimeter to represent K(t). The evolution is obtained as a limit of a time‐stepping scheme. Variational minimizations are employed to approximate the curvature motion. Stochastic calculus is used to prove global energy estimates, which in turn give a tightness statement of the approximating evolutions.
On the Reflection of Electrons from Crystal Lattices

Davisson and Germer(1) have recently published their very interesting results on reflection of electrons from a single crystal of nickel. These results have been interpreted by analogy with the reflection of X-rays from crystals. This analogy, however, is not complete. The purpose of this short note is to point out the differences between the two phenomena. For the mathematical treatment use is made of the recent development of quantum mechanics (wave mechanics).
Polyandrocarpamides A-D, novel metabolites from the marine ascidian polyandrocarpa sp.

Abstract Four new indole-derived metabolites (1-4), including the iodinated polyandrocarpamide B (2), have been isolated from the colonial marine ascidian Polyandrocarpa sp. collected in the Philippines. The structures of these metabolites were determined through spectral interpretation, chemical conversions and by comparisons with a synthetic phenethylamine analog.
HYPERTENSION AND MAJOR VASCULAR, CAROTID, AORTIC, AND PERIPHERAL PROCEDURES: Implications and Treatment Modalities

Hypertension affects more than 60 million Americans and is present in up to 55% of patients who undergo peripheral vascular surgery. It is the most common derangement of the circulatory system. 19,52 Patients with hypertension have an increased risk of coronary artery disease, congestive heart failure, renal failure, and cerebrovascular accidents when compared to normotensive patients. 62 In one study, only 20% of hypertensive patients were found to have adequate blood pressure control. 72
Real classification of complex quadrics

Abstract Canonical forms are given for complex quadric surfaces (and conics) under real changes of variable. The basic idea is to use known results on pairs of real quadratic forms.
Titanium, chromium and cobalt ions modulate the release of bone-associated cytokines by human monocytes/macrophages in vitro.

Osteolysis has become a major cause of aseptic loosening in total joint arthroplasty (TJA). Titanium, cobalt and chromium are commonly used in orthopaedic implants (e.g. joint prostheses). The release of bone-associated cytokines has been associated with the development of osteolysis in patients with prostheses. We evaluated the effects of these metals on the release of bone-associated cytokines (IL-1 beta, IL-6, TNF-alpha and TGF-beta 1) by human blood monocytes/macrophages and monocyte-like U937 cells upon lipopolysaccharide (LPS) stimulation, the cell proliferation, and their cytotoxic effects on these cells in vitro. We found that the release of IL-1 beta was enhanced by titanium, chromium and cobalt, the release of TNF-alpha was enhanced by titanium and chromium, and the release of IL-6 was enhanced by titanium. All three metal ions inhibited the release of TGF-beta 1. We also found that titanium and chromium, but not cobalt, enhanced blood monocyte/macrophage proliferation in response to LPS while only titanium enhanced U937 cell proliferation in response to LPS. The metals in concentrations ranging from 0.01 to 100 ngml-1 did not stimulate the cells to secrete detectable cytokines in the absence of LPS. Furthermore, a 4-h pre-exposure of blood monocytes/macrophages or U937 cells to the metals did not alter cytokine release when the metals were removed from the media prior to the addition of LPS. Similarly, a 4-h pre-exposure of blood monocytes/macrophages or U937 cells to LPS did not alter cytokine release when LPS was removed from the media prior to the addition of the metals. The metals did not reduce cell viability and induce cell injury after 72h incubation with the cells. The data suggest that the three metals at clinically relevant concentrations modulated cytokine expression, whereas they did not induce any cytotoxic effects. A metal-induced enhancement of bone-resorbing cytokine release with a concomitant inhibition of bone-forming cytokine release may be an important factor in the development of osteolysis, which can severely compromise the outcome of TJA.
Serum dopamine β-hydroxylase and free fatty acids in exercise-induced asthma

Summary Serum dopamineβ-hydroxylase activity, which is thought to reflect noradrenaline secretion, and free fatty acid level were measured in twenty atopic asthmatic children, of whom ten had exercise-induced asthma (EIA), after exercise on the treadmill. There was a significant decrease in the level of serum dopamine β-hydroxylase activity in the asthmatics who developed EIA and this closely accompanied the onset of airflow obstruction. There was no change in the free fatty acid levels. In contrast, the asthmatics, who did not have EIA showed a significant rise in the levels of dopamine β-hydroxylase activity and free fatty acids after the same exercise task. Our results suggest that the atopic children studied, who developed EIA, may have had an impaired noradrenaline response to exercise. It is further suggested that this impaired noradrenaline secretion may facilitate mediator release and contribute to the airflow obstruction in EIA.
The use of alcohol home delivery services by male problem drinkers: a preliminary report

Alcohol home delivery services (AHDS) provide convenient and confidential access to alcohol, yet little is known about their use. The purpose of this report is to present preliminary data describing the use of AHDS by problem drinkers. We surveyed 174 males regarding social and demographic characteristics, alcohol use history, and use of AHDS. Use of AHDS was most common among problem drinkers. When statistically controlling for the effects of demographic and social characteristics, regular drinkers without a history of alcohol problems were significantly less likely to have had alcohol delivered than problem drinkers, p = .0036. Contrary to expectation, medically ill alcoholics with advanced and disabling medical complications of heavy drinking were not more likely than other problem drinkers to have alcohol delivered. Living in an urban area and not having a vehicle available were associated with the use of AHDS. The public health and safety considerations of alcohol availability via home delivery are discussed.
Landscape planning and the city

Abstract It is imperative that landscape planners address the problems of the city. This paper focusses on the case of Boston, M.A., U.S.A., and its derelict lands and degraded water resources. It discusses both the problems and their potential for creative landscape planning.
The Effect of Cattle Manure Enriched With ERP Fertilizer on Seed Yield of Soybean (Glycine max) in Sandy Regosol

The experiment was carried out in the Eastern region of Sri Lanka to evaluate the effect of cattle manure with different levels of rock phosphate application on seed yield of soybean ( Glycine max ) in sandy regosol. The air dried cattle manure (CM) (10 t/ha) with ERP fertilizer (eppawela rock phosphate) at 0-100 kg/ha and also recommended chemical fertilizers as a control were applied two weeks and two days before sowing respectively as a basal fertilizer application. The six treatments were arranged in a randomized complete block design with four replications. The yield response to each treatment was observed at the harvesting stage. The results revealed that significant differences (P Journal of Food and Agriculture 2010 Vol. 03, No. 1 & 2, Page 24-30 DOI: http://dx.doi.org/10.4038/jfa.v3i1-2.5167
Education and the selection task

The present study was concerned with the effects of education level and area of expertise on performance on the standard abstract selection task. Subjects had received bachelor’s or doctoral degrees. Contrary to some recent results reported by Hoch and Tschirgi (1985), no effect of education level was found. However, there was a significant effect for area of expertise. Subjects trained in mathematics performed better than subjects from computer science, electrical engineering, and the social sciences. An explanation in terms of the mathematics subjects’ greater likelihood of using a disconfirmation strategy and greater familiarity with the relevant propositional logic is offered.
Homeless Youth: Characteristics, Contributing Factors, and Service Options

Distinguishing between causes and consequences of youth homelessness is often difficult. Characteristics may have existed prior to youths' leaving home, likely contributing to their running away, or may develop once the youths become immersed in “street culture.” Owing to these complexities, characteristics and contributing factors associated with youth homelessness often intersect. Homeless youths' diverse backgrounds and experiences, including difficult family circumstances and exposure to victimization, require services that meet their unique needs. Services provided to homeless youth include basic services (e.g., food, shelter, and clothing), medical care, case management, independent living-skills training, and referrals. The literature concerning these issues is reviewed.
When is an amniocentesis for fetal maturity unnecessary in nondiabetic pregnancies at risk

Abstract For several years standard obstetric practice has been to perform an amniocentesis for evaluation of fetal maturity. In order to provide a more definitive answer as to which pregnancies need an amniocentesis, a group of 294 nondiabetic pregnant women in whom an amniocentesis for the evaluation of fetal maturity had been performed for clinical indications were evaluated. Three predictors of fetal maturity—obstetric estimate of gestational age, fetal biparietal diameter, and ultrasonic determination of placental maturation—were evaluated for their ability to predict three outcomes of fetal maturity, including positive amniotic fluid phosphatidylglycerol, pediatric estimate of gestational age ≥38 weeks, and absence of hyaline membrane disease. A fetal biparietal diameter of ≥90 mm was present in 36% of the total population and was associated with 97% term delivery, 87% positive amniotic fluid phosphatidylglycerol, and 0% hyaline membrane disease. The results associated with an obstetric estimate of gestational age of ≥38 weeks were similar. In the present data set over one third of clinically indicated amniocenteses could potentially be avoided without losing any predictive capability for fetal maturity.
Survival, growth, and histopathological effects of paraquat ingestion in nestling American kestrels (Falco sparverius)

The use of paraquat as a herbicide is becoming more extensive with the increasing popularity of no tillage agriculture, increasing the possibility of exposure for wildlife species. American kestrel(Falco sparverius) nestlings were orally dosed daily with 5 μl/g of distilled water (controls), 10 mg/kg, 25 mg/kg, or 60 mg/kg of paraquat dichloride (1,1′-dimethyl-4,4′-bipyridinium) in distilled water from day 1 through day 10. Forty-four percent of the nestlings given 60 mg/kg died after 4 days. Significant differences in growth rates occurred between controls and all paraquat-dosed groups. Reduced skeletal growth occurred in the humerus and femur in the 25 mg/kg and 60 mg/kg groups, and in the radius-ulna and tibiotarsus in the 60 mg/kg group. Skeletons were otherwise normal in appearance. Histopathological examination revealed localized focal necrosis in the liver of one nestling in the 60 mg/kg group and tubular cell degeneration and focal tubular dilation in the kidneys of another. The brain and lungs were unremarkable histologically. These findings suggest that altricial nestling kestrels are more sensitive to paraquat exposure than young or adult birds of precocial species.
Facets of Right‐Wing Authoritarianism Mediate the Relationship Between Religious Fundamentalism and Attitudes Toward Arabs and African Americans

Since the September 11 terrorist attacks, hate crimes against Arabs have increased in the United States. Despite recent increases in anti-Arab attitudes, little psychological research has been conducted to understand this prejudice. Across two studies, we tested a theoretical model of Arab and African-American prejudice. We found the aggression facet of right-wing authoritarianism mediated the relationship between religious fundamentalism (RF) and prejudice toward Arabs and African Americans. Results are interpreted in light of previous research on cognitive rigidity, RF, and prejudice, and implications are made for political leaders conversing about Arab nations and peoples.
Coherency Strain and Dislocations in Copper-Rich-Precipitate Embrittled A710 Ferritic Steels

The irradiation embrittlement of reactor pressure vessel steels was studied on surrogate samples of A710 ferritic steels, which is rich in copper. Dislocations and coherency strain caused by the copper-rich precipitates, as a function of aging time, were studied by small-angle neutron scattering, diffraction line-broadening analysis, transmission electron microscopy, and Eshelby inclusion method. Aging has induced copper-rich precipitate nucleation and growth, thus impeding the dislocation motion and hardening the steels. The precipitates are coherent with the matrix up to about 3.5 nm in radius, when they become semi coherent with the ferritic matrix, thus relaxing strains/stresses and softening it. There is good agreement between all experimental techniques used and the Eshelby inclusion model.
Comparisons between operant response and 1,1,1-trichloroethane toxicokinetics in mouse blood and brain

The effect of 1,1,1-trichloroethane (TRI) inhalation on operant response was evaluated in relation to the concentration of TRI in blood and brain tissue in mice during exposure. Male CD-1 mice were trained to lever-press for an evaporated milk reinforcer on a variable interval (VI 60) schedule for 2 h. Trained mice were then exposed to either 3500 or 5000 ppm TRI for 100 min, and the changes in the schedule-controlled performance were measured. Additional groups of mice were exposed under the same conditions as those used in the behavioral study and sacrificed at various times during exposure, and the blood and brain samples were collected and subsequently analyzed for TRI content by headspace gas chromatography. Uptake of TRI into blood and brain was rapid, with near steady-state levels reached after approximately 40-60 min of exposure. Inhalation of 5000 ppm, but not 3500 ppm TRI was seen to cause inhibition of operant response, starting approximately 30 min following the initiation of inhalation exposure and beginning to recover after 80 min of exposure. The threshold concentrations for the maximal behavioral inhibition were approximately 110 micrograms/g and 130 micrograms/ml in mouse brain and blood, respectively. It appears that in addition to TRI concentrations in blood and brain tissue, the time it takes to reach the apparent threshold TRI concentration was also a determinant for the onset of TRI neurobehavioral depression.
Deconstructing public confidence in state courts

Abstract Although researchers have consistently demonstrated the importance of confidence in public institutions like the courts, relatively little attention has been paid to understanding what confidence itself really is. This article presents data from two samples of community members, thereby building on and extending a preliminary investigation that sought to understand constructs related to confidence in state courts with student samples. Structural equation modelling results provide support for the dimensionality of the measures and indicate that dispositional trust has little to no independent effect on confidence. However, tendency to trust in governmental institutions, cynicism toward the law and felt obligation to obey the law are important predictive constructs. The current results are important both for researchers seeking to understand confidence in the courts and the judges and administrators who would seek to increase it.
Renormalon contributions to Δϱ

Abstract Leading QCD vacuum polarization contributions to the electroweak parameter Δϱ are evaluated numerically using several different prescriptions for the gluon self-energy. Simple theoretical estimates of the asymptotic behavior are given. The results show a significant contribution from the leading infrared renormalons when Δϱ is expressed in terms of the top-quark pole mass and its absence when the MS running mass is employed. The calculations are applied to estimate higher-order QCD contributions to Δϱ.
Maximum power point tracking of a variable speed PMSG wind power system with DC link reduction technique

A new controller to track the maximum power point (MPP) of a variable speed wind energy conversion system (WECS) incorporating permanent magnet synchronous generator (PMSG) along with DC link reduction is presented in this paper. The power extracted from the turbine is affected by the double line frequency voltage ripple present in the DC link of the system. The traditional large electrolytic capacitors used for the DC link are bulky and less reliable, thereby reducing the reliability of the system. The replacement of these capacitors with lower capacity film capacitors which are costlier and more reliable proves to be a viable solution for this problem. So, an algorithm to track the MPP along with the DC link reduction is proposed. The proposed method is implemented, analyzed and verified in MATLAB/SimPowerSystem. The simulation results obtained clearly shows the effectiveness of the proposed control strategy for WECS based on the PMSG.
Postural Hypotension Induced by Atropine Sulfate

Previous tests on the use of large doses of atropine for the treatment of anticholinesterase poisoning have revealed postural hypotension following the administration of 2 mg. of this drug. In this study on 78 normal adult males, the cardiovascular responses to positional change after 2 mg. atropine have been measured and the mechanisms elucidated. Blood pressure response to tilting was normal during control and placebo phases, but showed a profound alteration after atropine.
Influence of Emotional Intensity and Frequency of Positive and Negative Events on Depression

This study replicates and extends aspects of psychological behaviorism's analysis of the role of positive and negative events in depression. As a first step, four pilot studies were conducted to develop a positive and negative events rating scale. This measure assesses the emotional intensity of positive and negative events (i. e., the strength of the positive or negative emotional response produced by the event) as well as the frequency of occurrence of the positive and negative events. A sample of 1089 college students then completed the Beck Depression Inventory and this new life events measure. Consistent with psychological behaviorism's analysis that emotional intensity involves a personality process and frequency an environmental process, the results showed that the emotional intensity of positive and negative events as well as the frequency of positive and negative events had independent roles in the prediction of depression (i. e., each of the four variables predicted depression after controlling ...
Cognitive vision for efficient scene processing and object categorization in highly cluttered environments

One of the key competencies required in modern robots is finding objects in complex environments. For the last decade, significant progress in computer vision and machine learning literatures has increased the recognition performance of well localized objects. However, the performance of these techniques is still far from human performance, especially in cluttered environments. We believe that the performance gap between robots and humans is due in part to humans' use of an attention system. According to cognitive psychology, the human visual system uses two stages of visual processing to interpret visual input. The first stage is a pre-attentive process perceiving scenes fast and coarsely to select potentially interesting regions. The second stage is a more complex process analyzing the regions hypothesized in the previous stage. These two stages play an important role in enabling efficient use of the limited cognitive resources available. Inspired by this biological fact, we propose a visual attentional object categorization approach for robots that enables object recognition in real environments under a critical time limitation. We quantitatively evaluate the performance for recognition of objects in highly cluttered scenes without significant loss of detection rates across several experimental settings.
Failure of Ambulatory Electrocardiographic Monitoring to Predict Results of Programmed Electrical Stimulation: Studies in Patients with Clinical Ventricular Tachyarrhythmias

To test for an association between the results of ambulatory electrocardiographic monitoring (AEM) and programmed electrical stimulation (PES), or whether other factors better predict the results of PES, 57 patients (36 male and 21 female patients) presenting with either ventricular fibrillation (49 percent; 28/57) or sustained ventricular tachycardia (51 percent; 29/57) were studied. Each patient underwent AEM and PES using up to three ventricular extrastimuli. Sixty-three percent (36/57) had coronary disease; and of these, ventricular tachycardia was present during AEM in 64 percent (23/36) and induced by PES in 78 percent (28/36). With the addition of patients with other cardiac diagnoses, the results were 58 percent (33/57) and 60 percent (34/57), respectively. No AEM variable was positively associated with inducible ventricular tachycardia, including frequency of ventricular premature depolarizations, multiformity, couplets, or ventricular tachycardia. Clinical variables positively associated with inducible ventricular tachycardia were coronary disease, previous myocardial infarction, left ventricular dysfunction, male sex, and a history of recurrent arrhythmia. Therefore, clinical characteristics are more useful for predicting the results of PES than information derived from AEM.
AUTOIMMUNE POLYGLANDULAR SYNDROME, PRIMARY EMPTY SELLA, AND ACUTE LYMPHOCYTIC LEUKAEMIA

SUMMARY A young man is reported with an autoimmune polyglandular syndrome (APS) characterized by Addison's disease, primary hypothyroidism, primary hypogonadism, vitiligo, associated with primary empty sella and partial impairment of pituitary hormone secretion. Two years later the patient showed a null cell type acute lymphocytic leukaemia, immediately after surgery for an inguinal hernia. Pathogenetic mechanisms are postulated on the basis of HLA studies and lymphocytic typing.
Paclitaxel impairs adipose stem cell proliferation and differentiation.

Abstract Background Cancer patients with chemotherapy-induced immunosuppression have poor surgical site wound healing. Prior literature supports the use of human adipose–derived stem cell (hASC) lipoinjection to improve wound healing. It has been established that multipotent hASCs facilitate neovascularization, accelerate epithelialization, and quicken wound closure in animal models. Although hASC wound therapy may benefit surgical cancer patients, the chemotherapeutic effects on hASCs are unknown. We hypothesized that paclitaxel, a chemotherapeutic agent, impairs hASC growth, multipotency, and induces apoptosis. Methods hASCs were isolated and harvested from consented, chemotherapy and radiation naive patients. Growth curves, MTT (3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide), and EdU (5-ethynyl-2-deoxyguridine) assays measured cytotoxicity and proliferation. Oil Red O stain, Alizarin Red stain, matrigel tube formation assay, and quantitative polymerase chain reaction analyzed hASC differentiation. Annexin V assay measured apoptosis. Immunostaining and Western blot determined tumor necrosis factor α (TNF-α) expression. Results hASCs were selectively more sensitive to paclitaxel (0.01–30 μM) than fibroblasts (P Conclusions Paclitaxel is more cytotoxic to hASCs than fibroblasts. Paclitaxel inhibits hASC proliferation, differentiation, and induces apoptosis, possibly through the TNF-α pathway. Paclitaxel's severe inhibition of endothelial differentiation indicates neovascularization disruption, possibly causing poor wound healing in cancer patients receiving chemotherapy.
Grievance Practices in Post‐Soviet Kyrgyz Agriculture

This article examines legal consciousness in action as expressed in grievances arising from commercial transactions among sellers and buyers in the new post-Soviet economy of Kyrgyzstan. Using focus groups, direct observation, and participant observation, I investigate the transformation of disputes between Kyrgyz vegetable growers and processors. My data show variation in the way grievances are dealt with among Kyrgyz farmers. Farmers opt out of the contractual relationship, remain in the relationship, or practice a combination of the two over time. The farmers included in this study did not seek legal remedies through the court system. Data also reveal that expressions of grievances transform in tandem with an evolution of feelings—from anger and distrust to understanding and even sympathy for the party responsible for the grievance.
Product market power, industry structure, and corporate earnings management

Abstract This is the first study to establish a link between product market power of firms and the degree of earnings management. We hypothesize and document a significant and robust association between (a) a firm’s product market pricing power and its degree of earnings management, and (b) industry competitiveness and the degree of earnings management in the industry. Our study reveals that firms with inferior product market pricing power engage in greater discretionary earnings accruals, adding a new dimension to our understanding of the transparency and informativeness of firms’ financial statements. These findings are mirrored at the industry level where we document that more competitive industries are associated with greater earnings manipulation. The empirical evidence has direct implication on the informativeness and earnings quality of firms based on their product market power and competitiveness.