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This study examined factors that impact Black middle and high school students' academic and psychosocial well-being. Qualitative analysis of focus group data using grounded methodological approach on 51 middle and high school students in a predominantly White urban school district. Findings show Black students are constantly exposed to racial microaggressions (i.e. microinvalidation, microinsult, microassault) which impact their overall academic performance and psychosocial well-being. Use of request to use the N-word was a common and stressful form of microaggression encountered by Black students. Overall, racial microaggressions (e.g. use/request to use the "N" word) are common, stressful and begin early among Black students attending predominantly White schools. Black students recognize the commonplace nature of racial microaggressions and actively identify coping mechanisms (e.g. safe shared on-campus spaces, identifying concrete steps schools can take to create safe environment). Concerted efforts by schools are needed to prevent/mitigate the harmful effects of microaggression exposure to students. [ABSTRACT FROM AUTHOR]

A major limitation of research on attitudes toward suicide is that most measures lack evidence of a stable factor structure. To investigate the structure of recently developed stigma of suicide scale-short form (SOSS-SF), we conducted an exploratory factor analysis in a sample of 499 undergraduates. Results revealed a three-factor structure: Stigma, Isolation/Depression, and Glorification/Normalization. We also identified good convergent and discriminant validity between the SOSS-SF and related constructs. In a separate sample of 570 undergraduates, a confirmatory factor analysis (CFA) demonstrated adequate fit for the three-factor model. In addition, a multiple-group CFA demonstrated invariance across gender. [ABSTRACT FROM AUTHOR]

Purpose – Venture creation is often seen as the form of academic entrepreneurship least compatible with the role of university scientists. The purpose of the article is to explore the changing role of university scientists towards venture creation, and understand the influence of university-driven initiatives for venture creation. Design/methodology/approach – The article is based on a qualitative study of two venture creation cases: one from a US university, and one building from two universities in Sweden. The cases and associated university environments were selected due to their venture creation activity. University venture creation data of the three universities complements the cases. Findings – Venture creation at universities can be more compatible with the traditional role of the university scientist. Centers and laboratories concerned with entrepreneurship and action-based education are identified as key university resources allowing university scientists to engage in venture creation in more compatible ways, and not having to become the lead venture creator. Research limitations/implications – The study underlying the article is limited to three university environments (in two countries) where venture creation activity is relatively frequent. Originality/value – The article shows that venture creation can be more compatible with the role of the university scientist due to more collective entrepreneurial activity at universities. Furthermore, university scientists, in synergizing between different entrepreneurial roles, are important for venture creation without taking the lead venture entrepreneur role. Involving students in venture creation together with scientists is proposed as one such important entrepreneurial role that has not previously been recognized. [ABSTRACT FROM AUTHOR]

Purpose - The purpose of this paper is to examine how legitimacy as "an entrepreneur" is gained in relation to others during the nascent phase. Design/methodology/approach - The author studies two firm creating teams over a 12-month incubation period. Data collected through participant observation, documentation and interviews are emploted as narratives in order to explore how nascent entrepreneurs gain legitimacy through social interaction. Positioning theory is used to explore how negotiated rights and duties are employed towards legitimacy-gaining strategies. Findings - Conforming, selecting and manipulating strategies are used to gain legitimacy during a process of firm creation through interactive dialogue with key stakeholders (role-set). Positioning facilitates a process of negotiated rights and duties that helps to define the role of "entrepreneur" to which the nascent entrepreneurs aspire. Research limitations/implications - The study is bounded to a specific contextual setting and thus initial findings would benefit from further investigation in comparable and control settings. Findings illustrate the ways in which nascent entrepreneurs employ legitimacy-gaining strategies through interaction with key stakeholders, an area of research not well understood. This contributes to an understanding of how entrepreneurial identity is developed. Practical implications - Designed firm creation environments can facilitate interaction with key stakeholders and support positioning of nascent entrepreneurs as they attempt to gain legitimacy in the role of "entrepreneur", while creating a new firm. Legitimacy-gaining strategies can strengthen entrepreneurial identity development, which can be applied to multiple entrepreneurial processes. Originality/value - The article accesses individuals in the process of becoming entrepreneurs, a phenomenon most often studied in hindsight. Emphasis on stakeholder interaction as contributing to entrepreneurial development is also understudied. Legitimacy-gaining strategies are explored through narratives using positioning theory, an approach which has been discussed conceptually but not readily applied empirically. [ABSTRACT FROM AUTHOR]

The article explores the issue of drug use in training and racing of horses in the U.S. The current drug use in the horse racing industry, including anabolic steroids, corticosteroids and anti-bleeding medications was addressed. It examines the inconsistencies of state regulation in order to illustrate the need for greater transparency and uniformity in thoroughbred horsing.

Aβ (amyloid-β peptide) assembles to form amyloid fibres that accumulate in senile plaques associated with AD (Alzheimer's disease). The major constituent, a 42-residue Aβ, has the propensity to assemble and form soluble and potentially cytotoxic oligomers, as well as ordered stable amyloid fibres. It is widely believed that the cytotoxicity is a result of the formation of transient soluble oligomers. This observed toxicity may be associated with the ability of oligomers to associate with and cause permeation of lipid membranes. In the present study, we have investigated the ability of oligomeric and fibrillar Aβ42 to simultaneously associate with and affect the integrity of biomimetic membranes in vitro. Surface plasmon field-enhanced fluorescence spectroscopy reveals that the binding of the freshly dissolved oligomeric 42-residue peptide binds with a two-step association with the lipid bilayer, and causes disruption of the membrane resulting in leakage from vesicles. In contrast, fibrils bind with a 2-fold reduced avidity, and their addition results in approximately 2-fold less fluorophore leakage compared with oligomeric Aβ. Binding of the oligomers may be, in part, mediated by the GM1 ganglioside receptors as there is a 1.8-fold increase in oligomeric Aβ binding and a 2-fold increase in permeation compared with when GM1 is not present. Atomic force microscopy reveals the formation of defects and holes in response to oligomeric Aβ, but not preformed fibrillar Aβ. The results of the present study indicate that significant membrane disruption arises from association of low-molecular-mass Aβ and this may be mediated by mechanical damage to the membranes by Aβ aggregation. This membrane disruption may play a key role in the mechanism of Aβ-related cell toxicity in AD. [ABSTRACT FROM AUTHOR]

The article presents a study on the aspects of balanced student participation in college classes. The authors examine the effects of a randomized participation credit on the percentage of students participating in college general education classes. They mention that the amount and quality of class discussion depends on the issues being studied in the general education course. They state that their research suggests relationships between the quantity of students' participation and the level of critical thinking.

BACKGROUND/AIMS: High viscosity silicone oils are used as tamponade agents to increase the resistance to emulsification; however, this makes the oils more difficult to inject. Increasing the extensional viscosity is one way to reduce emulsification. This study aimed to evaluate how silicone oils with increased extensional viscosity behave in terms of their ease of injection. METHODS: The shear viscosity and the length of time taken to inject 9 ml of Siluron 1000, Siluron 2000, Siluron 5000, SiliconMate, a 56/44 w/w blend of Siluron 1000/Siluron 5000 (Blend A) and a 90/10 w/w blend of Siluron 1000/PDMS 423kDa molecular weight (Blend B) were examined. RESULTS: The shear viscosity of Siluron 1000, Siluron 2000 and Siluron 5000 were within the expected ranges. The shear viscosity of Blend A was 2283 mPa s, Blend B was 4710 mPa s and SiliconMate was 995.3 mPa s. Siluron 1000 and SiliconMate had the shortest injection times as expected due to their lower shear viscosities. Comparison of Siluron 2000 and Blend A demonstrated that Siluron 2000 was easier to inject. Similarly, Blend B was easier to inject than Siluron 5000. CONCLUSION: Silicone oil blends containing small percentages of a high molecular weight additive are easier to inject than single grade oils of the equivalent shear viscosity. [ABSTRACT FROM AUTHOR]

Activation energies for energy and electron transfer have been measured in various systems on silica gel. In the case of ion-electron recombination, a facile technique involving fluorescence recovery is described which complements diffuse reflectance spectroscopy in the study of these systems. In bimolecular anthracene/azulene systems, activation energies have been shown to be independent of pre-treatment temperature in the range 25–210 °C, demonstrating that physisorbed water plays little role in determining diffusion rates on silica gel. In a ternary anthracene/azulene/perylene system, we have for the first time presented comparative activation energies for the diffusion of azulene and its radical cation, and have shown a greater activation energy for diffusion of the latter species. [ABSTRACT FROM AUTHOR]

Electron transfer reactions have been studied between 9-anthracenecarboxylic acid co-adsorbed with perylene on silica gel surfaces employing azulene as a molecular shuttle in order to facilitate hole transfer. In this paper we present for the first time a ternary system that unambiguously demonstrates an appreciable mobility of radical cations on the silica gel surface. Rates of hole transfer from the 9-anthracenecarboxylic acid radical cation to perylene viaazulene have been studied using diffuse reflectance laser flash photolysis spectroscopy. Azulene has been shown to enhance the rate of electron transfer in the ternary system, proving significant mobility of the azulene and its radical cation species on silica gel surfaces. The data shows that the azulene radical cation can diffuse at an appreciable rate on the silica gel surface. [ABSTRACT FROM AUTHOR]

Purpose – Several types of entrepreneurship with a societal purpose coincide in Sweden today, some stemming from older domestic traditions, others being more recent foreign influences. This paper aims to interrelate social, civic, community, and other entrepreneurships in search of a more unifying concept of societal entrepreneurship for Sweden and beyond. Design/methodology/approach – As part of a larger study, Swedish researchers and practitioners promoting some kind of entrepreneurship with societal purpose, are interviewed and asked for examples and literature references. Altogether 176 actors are identified and 59 are interviewed. The main distinguishing factors between different discourses of entrepreneurship are accounted for as well as results from workshops where actors representing different discourses partook. Findings – Seven societally oriented entrepreneurship discourses are distinguished, with different foreign or domestic origins. Key characteristics for interrelating different discourses are the type of actor (individual and/or collective) and purpose (social/ecological and/or economic) emphasized in a discourse. Interactions documented from workshops indicate a potential in unifying different entrepreneurships within a widened understanding of societal entrepreneurship. Research limitations/implications – The field of entrepreneurship emphasizing societal utility is fragmented with many parallel discourses. The conceptual analysis and empirical findings imply that there is potential in a more unifying concept. Furthermore, in the limited Swedish setting, collective dimensions of entrepreneurship stand out. This nevertheless implies that collective engagements into entrepreneurship of any kind are worthy of more research and recognition. Practical implications – Implications are primarily limited to societal entrepreneurship within uncontested welfare states, such as Sweden, where most established societal needs are taken care of through taxes utilized by a public sector. Societal entrepreneurship in such a setting becomes a mechanism for renewal and experimentation. Originality/value – The paper is original in its approach to identifying and interrelating current discourses in Sweden. [ABSTRACT FROM AUTHOR]

-Galactosidase (-gal) (encoded by thelacZ gene) has been widely used as a transgene reporter enzyme. The ability to image lacZ expression in living transgenic animals would further extend the use of this reporter. It has been reported that 7-hydroxy-9H-(1,3-dichloro-9,9-dimethylacridin-2-one)--d-galactopyranoside (DDAOG), a conjugate of -galactose and 7-hydroxy-9H-(1,3-dichloro-9,9-dimethylacridin-2-one), is not only a chromogenic lacZ substrate but that the cleavage product has far-red fluorescence properties detectable byin vivo imaging. In an attempt to noninvasively image lacZ expressionin vivo, we applied fluorescence imaging to a G protein-coupled receptor (GPR56), knockout (KO) mouse model, in which thelacZ gene is introduced in the GPR56 locus. Compared to wild-type (WT) mice, GPR56KO/LacZ mice showed three- to fourfold higher fluorescence intensity in the head area 5 min after tail-vein injection of DDAOG. -Gal staining in sections of whole brain showed strong lacZ expression in homozygotes, but not in WT mice, consistent with lacZ activity detected byin vivo imaging. The kidneys were also visualized with fluorescence imaging bothin vivo andex vivo, consistent with -gal staining findings. Our results demonstrate that fluorescence imaging can be used forin vivo real-time detection of lacZ activity by fluorescence imaging inlacZ transgenic mice. Thus, this technology can potentially be used to noninvasively image changes of certain endogenous molecules and/or molecular pathways in transgenic animals. [ABSTRACT FROM AUTHOR]

SYNOPSISPalynomorphs, especially dinoflagellate cysts (dinocysts), have been at the forefront of research carried out on Mesozoic?Cenozoic sediments on the Scotian Margin over the last 30?40 years: this research has been driven by the need to develop a stratigraphical framework to better understand the region''s petroleum systems. To support the compilation of a detailed event stratigraphical scheme for the Late Cretaceous to Cenozoic of the margin, emphasising dinocysts but with information from other fossil groups and non-biostratigraphical data, there is a need to formalise the dinocyst taxonomy. In this paper, we fulfill this need by illustrating and, where appropriate, describing and discussing taxa used in our event biostratigraphical scheme. The following taxa (dinocysts except where indicated) are new: Areoligera circumsenonensis, Axiodinium, Axiodinium prearticulatum, Cordosphaeridium delimurum, Glaphyrocysta extensa, Hafniasphaera delicata, Impletosphaeridium capitatum, Mendicodinium robustum(validation of previously proposed name), Minisphaeridium, Oligokolpoma, Oligokolpoma tubulus, Palaeocystodinium obesum, Palaeocystodinium teespinosum, Palaeohystrichophora palaeoinfusa, Pentadinium sabulum, Pervosphaeridium granaciculare, Talladinium, Wetzeliella caviarticulataand Cingutriletes tyriskos(a trilete spore). The following are newly proposed combinations (with a former name in parentheses): Cerebrocysta waipawaensis(Pyxidinopsis waipawaensis), Cerodinium glabrum(Cerodinium speciosumsubsp. glabrum), Dinopterygium alatum(Xiphophoridium alatum), Kleithriasphaeridium cooksoniae(Florentinia cooksoniae), Kleithriasphaeridium perforatum(Florentinia perforata), Minisphaeridium latirictum(Hystrichosphaeridium latirictum), Nyktericysta tripenta(Balmula tripenta), Pentadinium granulatum(Pentadinium laticinctumsubsp. granulatum) Talladinium? clathratum(Charlesdowniea clathrata) and Talladinium wulagenense(Charlesdowniea wulagenensis). Emendations of the following taxa are proposed: Apectodinium, Dinopterygium, Distatodinium, Glaphyrocysta, Hafniasphaera, Isabelidinium, Kleithriasphaeridium, Manumiella, Nyktericysta, Palaeocystodinium, Rhombodinium, Wetzeliellaand Wetzeliella articulata. Material from the Kiowa Formation of Kansas supports our concept of Dinopterygium. We review several morphological terms already in the literature and introduce the following new ones: mesotabular, obtabular, contabular, penicontabular, epeliform, equi-epeliform and lati-epeliform. [ABSTRACT FROM AUTHOR]

The AAA (ATPase associated with various cellular activities) proteins participate in membrane trafficking, organelle biogenesis, DNA replication, intracellular locomotion, cytoskeletal remodelling, protein folding and proteolysis. The AAA Vps (vacuolar protein sorting) 4 is central to traffic to lysosomes, retroviral budding and mammalian cell division. It dissociates ESCRTs (endosomal sorting complexes required for transport) from endosomal membranes, enabling their recycling to the cytosol, and plays a role in fission of intraluminal vesicles within MVBs (multivesicular bodies). The mechanism of Vps4-catalysed disassembly of ESCRT networks is unknown; however, it requires interaction between Vps4 and ESCRT-III subunits. The 30 C-terminal residues of Vps2 and Vps46 (Did2) subunits are both necessary and sufficient for interaction with the Vps4 N-terminal MIT (microtubule-interacting and transport) domain, and the crystal structure of the Vps2 C-terminus in a complex with the Vps4 MIT domain shows that MIT helices α2 and α3 recognize a (D/E)XXLXXRLXXL(K/R) MIM (MIT-interacting motif). These Vps2–MIT interactions are essential for vacuolar sorting and for Vps4-catalysed disassembly of ESCRT-III networks in vitro. Electron microscopy of ESCRT-III filaments assembled in vitro has enabled us to identify surfaces of the Vps24 subunit that are critical for protein sorting in vivo. The ESCRT-III–Vps4 interaction predates the divergence of Archaea and Eukarya. The Crenarchaea have three classes of ESCRT-III-like subunits, and one of these subunits interacts with an archaeal Vps4-like protein in a manner closely related to the human Vps4–human ESCRT-III subunit Vps20 interaction. This archaeal Vps4–ESCRT-III interaction appears to have a fundamental role in cell division in the Crenarchaea. [ABSTRACT FROM AUTHOR]

Abstract:Schistosomiasis is a major neglected tropical disease that currently affects over 200 million people and leads to over 200,000 annual deaths. Schistosoma mansoniparasites survive in humans in part because of a set of antioxidant enzymes that continuously degrade reactive oxygen species produced by the host. A principal component of this defense system has been recently identified as thioredoxin glutathione reductase (TGR), a parasite-specific enzyme that combines the functions of two human counterparts, glutathione reductase and thioredoxin reductase, and as such this enzyme presents an attractive new target for anti-schistosomiasis drug development. Herein, we present the development of a highly miniaturized and robust screening assay for TGR. The 5-μl final volume assay is based on the Ellman reagent [5,5′-dithiobis(2-nitrobenzoic acid) (DTNB)] and utilizes a high-speed absorbance kinetic read to minimize the effect of dust, absorbance interference, and meniscus variation. This assay is further applicable to the testing of other redox enzymes that utilize DTNB as a model substrate. [ABSTRACT FROM AUTHOR]

Abstract  A procedure for producing somatic embryos enriched with dibenzyl trisulfide (DTS) using a hormone-dependent culture system is reported for Petiveria alliacea L. (Guinea hen weed). Leaf explants were cultured on a Murashige and Skoog medium supplemented with a range of naphthaleneacetic acid (NAA) concentrations and a fixed concentration of benzyladenine (BAP) at 11.0 μM and sucrose or glucose at 30 g l−1. Leaf explants cultured on all media types started to form callus at the cut surfaces of the discs 10–14 d after initiation. The type of sugar used influenced average fresh weight, the propensity to form roots, as well as the embryogenic response. The highest mean fresh weight (337.7 ± 26.18 mg) and mean root number (23.7 ± 1.69) was produced on media enriched with sucrose and supplemented with 53.7 μM NAA and 11.0 μM BAP. An ethanol extract of rhizogenic/embryogenic callus or somatic embryos was subjected to high-performance liquid chromatography analysis, which revealed the presence of DTS in both extracts. UV spectral analysis and the use of standard quantitation procedures showed that the quantity of DTS in the somatic embryo extract, at 0.16% (w/v), was approximately 30-fold higher than in rhizogenic/embryogenic callus (0.0055% w/v) of similar fresh weight. These results indicate that it is possible to biosynthesize approximately 6 mg of natural DTS from 3,808 mg of fresh somatic embryos within 10 wk from less than three leaf explants. [ABSTRACT FROM AUTHOR]

Current efforts to reconstruct organ doses in children undergoing diagnostic imaging or therapeutic interventions using ionizing radiation typically rely upon the use of reference anthropomorphic computational phantoms coupled to Monte Carlo radiation transport codes. These phantoms are generally matched to individual patients based upon nearest age or sometimes total body mass. In this study, we explore alternative methods of phantom-to-patient matching with the goal of identifying those methods which yield the lowest residual errors in internal organ volumes. Various thoracic and abdominal organs were segmented and organ volumes obtained from chest-abdominal-pelvic (CAP) computed tomography (CT) image sets from 38 pediatric patients ranging in age from 2 months to 15 years. The organs segmented included the skeleton, heart, kidneys, liver, lungs and spleen. For each organ, least-squared regression lines, 95th percentile confidence intervals and 95th percentile prediction intervals were established as a function of patient age, trunk volume, estimated trunk mass, trunk height, and three estimates of the ventral body cavity volume based on trunk height alone, or in combination with circumferential, width and/or breadth measurements in the mid-chest of the patient. When matching phantom to patient based upon age, residual uncertainties in organ volumes ranged from 53% (lungs) to 33% (kidneys), and when trunk mass was used (surrogate for total body mass as we did not have images of patient head, arms or legs), these uncertainties ranged from 56% (spleen) to 32% (liver). When trunk height is used as the matching parameter, residual uncertainties in organ volumes were reduced to between 21 and 29% for all organs except the spleen (40%). In the case of the lungs and skeleton, the two-fold reduction in organ volume uncertainties was seen in moving from patient age to trunk height--a parameter easily measured in the clinic. When ventral body cavity volumes were used, residual uncertainties were lowered even further to a range of between 14 and 20% for all organs except the spleen, which continued to remain at around 40%. The results of this study suggest that a more anthropometric pairing of computational phantom to individual patient based on simple measurements of trunk height and possibly mid-chest circumference or thickness (where influences of subcutaneous fat are minimized) can lead to significant reductions in organ volume uncertainties: ranges of 40-50% (based on patient age) to between 15 and 20% (based on body cavity volumes tied to trunk height). An expanded series of non-uniform rational B-spine (NURBS) pediatric phantoms are being created at the University of Florida to allow the full application of this new approach in pediatric medical imaging studies. [ABSTRACT FROM AUTHOR]

The distributions of the introduced nematode parasite, Angiostrongylus cantonensis, and the native Angiostrongylus mackerrasae in Australia are poorly understood. We sampled rodents and/or their faeces, and intermediate gastropod hosts for the presence of Angiostrongylus species in coastal forests surrounding Jervis Bay in south-eastern Australia. We found A. cantonensis in populations of introduced Rattus rattus in forests to the north of Jervis Bay, and A. mackerrasae in native Rattus fuscipes in forests to the south of Jervis Bay. The apparent geographical separation of these lungworm species may be a consequence of host specificity and negative associations between R. rattus and R. fuscipes that results from interspecific competition. A. cantonensis was regularly found in R. rattus or their faeces across 9 of 12 study sites north of Jervis Bay, and three species of snail common to the area were suitable intermediate hosts. This has potential negative implications for native wildlife and human visitors to these forests, because A. cantonensis infection causes zoonotic disease (neuro-angiostrongyliasis) in humans and a wide range of bird and mammal hosts. Management of pest rodents in the study area is warranted. [ABSTRACT FROM AUTHOR]

We construct an explicit map that transforms static, generalized sine-Gordon metrics to black hole type metrics. This, in particular, provides for a further description of the Cadoni correspondence (which extends the Gegenberg-Kunstatter correspondence) of soliton solutions and extremal black hole solutions in 2D dilaton gravity. [ABSTRACT FROM AUTHOR]

Abstract??Strategies for identifying urban youth with asthma have not been described for high school settings. African-American high school students are rarely included in asthma studies, despite a high risk of asthma mortality when compared to other age and race groups. Identification and follow-up of children with uncontrolled respiratory symptoms are necessary to reduce the burden of asthma morbidity and mortality, especially in underserved areas. We describe a process used to identify high school students who could benefit from intervention based on self-report of asthma and/or respiratory symptoms, and the costs associated with symptom-identification. Letters announcing a survey were mailed to parents of 9th?11th graders by an authorized vendor managing student data for the school district. Scan sheets with student identifiers were distributed to English teachers at participating schools who administered the survey during a scheduled class. Forms were completed by 5,967 of the 7,446 students assigned an English class (80% response). Although prevalence of lifetime asthma was 15.8%, about 11% of students met program criteria for enrollment through report of an asthma diagnosis and recent symptoms, medication use, or health care utilization. Another 9.2% met criteria by reported symptoms only. Cost of symptom-identification was $5.23/student or $32.29/program-eligible student. There is a need for school-based asthma programs targeting urban adolescents, and program initiation will likely require identification of students with uncontrolled symptoms. The approach described was successfully implemented with a relatively high response rate. Itemized expenses are presented to facilitate modifications to reduce costs. This information may benefit providers, researchers, or administrators targeting similar populations. [ABSTRACT FROM AUTHOR]

Animal decorations are normally interpreted as signals of quality. In spiders, however, decorations may have different functions, including the attraction of prey to the web or making the spider cryptic to predators. To date, there is scant evidence for the latter hypothesis. Here we use the burrow-decorating wolf spider Lycosa tarantula to test whether turrets around the burrow serve to prevent burrow invasion and predation from the Occitan scorpion Buthus occitanus. We located spiders and scorpions in field enclosures and manipulated the presence or absence of decorations or turrets. We found that the presence of the turret decreases the rate of burrow invasion and improves spider survival, possibly because the turret makes the burrow cryptic to scorpions. In addition, a field survey showed that burrows with larger decorations had a lower chance of being invaded by scorpions. These results provide evidence that the decoration has an antipredatory function in nature. [ABSTRACT FROM AUTHOR]

HLA-A3 and -A11 share similar peptide-binding motifs, however, it is unclear if promiscuous epitope presentation by HLA-A3 or HLA-A11 is associated with promiscuous TCR recognition. Here, we show that despite widespread cross-presentation of identical HIV-1 peptides in HIV-1-infected individuals expressing HLA-A3 or HLA-A11, peptides presented by HLA-A3 or HLA-A11 commonly exhibited clear immune distinctiveness with exclusive TCR recognition. Yet, using HLA-A3 and HLA-A11 tetramers for testing T cell cross-recognition of the HIV-1 Nef QK10 epitope, we observed in two study persons that specific CD8+ T cell populations were able to cross-recognize this peptide in the context of both HLA-A3 and HLA-A11. This cross-recognition was mediated by single cross-reactive TCRs, as shown by TCR sequencing in conjunction with TCR Vβ chain immunostaining. In each cross-reactive cell population, multiple TCR β chain variants were detected in the presence of only one TCR α chain variant. Thus, despite distinct TCR recognition of HLA-A3 or HLA-A11 presented HIV-1 peptides in the vast majority of cases, specific TCRs can cross-recognize their antigen in the context of both HLA-A3 and HLA-A11. [ABSTRACT FROM AUTHOR]

The year 2004 marked the bicentenary of Immanuel Kant’s death. This article evaluates the main arguments of Kant’s essay on perpetual peace in the light of developments in world politics since his time. How well have his ideas stood the test of time? Kant’s essay is placed in the context of his philosophy as a whole and through a close textual analysis the value of his propositions is assessed. The article looks at the Provisional and Definitive Articles in their mutual relation and places a good deal more emphasis than is usual upon the two supplements and appendix. Finally the article takes the complex circumstances of Kant’s home city, Kaliningrad, as a brief test case for his own theories. [ABSTRACT FROM AUTHOR]

Recently, the Department of Nursing at the University of South Dakota was recognized by the National League for Nursing as one of three Centers of Excellence nationally, and the program was selected for study by the Carnegie Foundation. This associate’s degree educational program has achieved an elevated degree of excellence because it adopted a number of elements that are associated with success in the leadership and organizational literature: (a) strong and sustained positive leadership, (b) passionate and involved people and partners, (c) a far-reaching but realistic vision, (d) open and exhaustive communication, (e) focus and relevance, and (f) effective execution. This article examines those characteristics of success and presents examples from the nursing education program at the University of South Dakota. [ABSTRACT FROM AUTHOR]

Abstract Interspecific hybridization has been implicated in population declines for some waterfowl species within the mallard complex, and hybridization with mallards (Anas platyrhynchos) is currently considered the largest threat to mottled ducks (A. fulvigula), one North American member of that complex. We assessed genetic variation among 225 mottled ducks and mallards using five microsatellite loci, and detected significant overall differences between these species within two geographic areas. We characterized hybridization in Florida, where mottled ducks are endemic and mallards are beginning to appear on the breeding grounds, and in South Carolina, where mottled ducks were introduced outside their native range. We used Bayesian genetic mixture analysis in an attempt to distinguish between these closely related species. In Florida, we detected two distinct genetic groups, and 10.9% of our samples from Florida mottled ducks were inferred to have been hybrids. In contrast only 3.4% of Florida mallards were inferred to have been hybrids, suggesting asymmetric hybridization. Populations from different geographic areas within Florida exhibited hybridization rates ranging from 0% to 24%. These data indicate a genetic component would be appropriate in actively managing interspecific hybridization in Florida mottled ducks. In contrast, South Carolina mottled ducks and mallards cannot be differentiated. [ABSTRACT FROM AUTHOR]

This study sought to determine whether drug-using male sex workers (MSWs) spatially bridge sexual networks across cities and to determine whether the behaviors of MSWs who bridge differ from the behaviors of those who do not. Data were collected from 42 MSWs in Houston, Texas, between May 2003 and February 2004. Spatial bridging was defined as having traded sex for money in another city before traveling to and trading in Houston. Cities bridged by MSWs were geographically plotted and were primarily located in the Gulf Coast and in Florida. Slightly less than half of MSWs were identified as spatially bridging from one city to another. A significantly higher proportion of MSWs who bridged cities were homosexual (55% vs. 23%) and HIV positive (31% vs. 5%). Those who bridged cities used marijuana and injected drugs more frequently and had significantly more male sex partners than MSWs who did not bridge cities. Despite the small sample size, this study found that many drug-using MSWs spatially bridge sexual networks in cities where they trade sex for money. [ABSTRACT FROM AUTHOR]

The performance test is one of a series of tests that compose the specification in a United States Pharmacopeia (USP) dosage form monograph. For an orally administered, nonsolution dosage form, it is usually satisfied by either a dissolution or disintegration procedure. Dissolution acceptance criteria are usually set in private negotiations between an applicant and a regulatory agency. With information about this private agreement and other information provided in a sponsor’s Request for Revision to USP, the USP’s Council of Experts elaborates a public dosage form monograph. Based on the relationship between the regulatory decisions and the Request for Revision, the USP dissolution procedure links to a regulatory judgment about bioavailability and bioequivalence and, ultimately, to a judgment about safety and efficacy. The current dissolution procedure and acceptance criteria are perceived as having worked well over the years and are generally accepted. This article discusses new approaches that merit consideration. These approaches focus on a) explicit use of hypothesis testing, b) use of parametric tolerance intervals, c) improved ways to set dissolution acceptance criteria, and d) a more flexible protocol to assess conformity. Application of the proposed approaches may better assess, manage, and communicate both manufacturer and consumer risk for dissolution testing. [ABSTRACT FROM AUTHOR]

Abstract Parallel “arms races” involving the same or similar phenotypic interfaces allow inference about selective forces driving coevolution, as well as the importance of phylogenetic and phenotypic constraints in coevolution. Here, we report the existence of apparent parallel arms races between species pairs of garter snakes and their toxic newt prey that indicate independent evolutionary origins of a key phenotype in the interface. In at least one area of sympatry, the aquatic garter snake, Thamnophis couchii, has evolved elevated resistance to the neurotoxin tetrodotoxin (TTX), present in the newt Taricha torosa. Previous studies have shown that a distantly related garter snake, Thamnophis sirtalis, has coevolved with another newt species that possesses TTX, Taricha granulosa. Patterns of within population variation and phenotypic tradeoffs between TTX resistance and sprint speed suggest that the mechanism of resistance is similar in both species of snake, yet phylogenetic evidence indicates the independent origins of elevated resistance to TTX. [ABSTRACT FROM AUTHOR]

The Common Garter Snake (Thamnophis sirtalis) preys upon the Rough-skinned Newt (Taricha granulosa), which contains the neurotoxin tetrodotoxin (TTX) in the skin. TTX is toxic, large quantities are present in a newt, and highly resistant snakes have the ability to ingest multiple newts; subsequently snakes harbor significant amounts of active toxin in their own tissues after consuming a newt. Snakes harbor TTX in the liver for 1 mo or more after consuming just one newt, and at least 7 wk after consuming a diet of newts. Three weeks after eating one newt, snakes contained an average of 42 μg of TTX in the liver. This amount could severely incapacitate or kill avian predators, and mammalian predators may be negatively affected as well. [ABSTRACT FROM AUTHOR]

We have investigated the use of AFLP® technology as a tool for the high throughput enrichment of Radiation Hybrid (RH) maps. The 3000 rad TM112 bovine RH panel was assayed with 37 EcoRI/TaqI AFLP primer combinations. The number of selective nucleotides used during PCR was increased to seven, to reduce the complexity of the AFLP profile and minimise the overlap between hamster and bovine bands co-amplified from hybrid cell clones. Seven-hundred-forty-seven bovine AFLP bands were amplified that could be distinguished following electrophoresis. Repeatability was tested within and between laboratories on independent template preparations and an error rate of 1.3% found. Two-point linkage analysis clustered 428 AFLP fragments in 39 linkage groups of at least 4 markers. Multi-point maps were constructed for 5 sample linkage groups. The study demonstrated that the AFLP approach could be used to rapidly screen for the most informative clones during panel construction and to increase the number of markers on RH maps, which could be useful for joining linkage groups formed by other markers. The use of AFLP markers as anchor points between existing RH maps and other physical maps, such as BAC contigs, is also discussed. [ABSTRACT FROM AUTHOR]

BACKGROUND:: The mechanism by which the opioid antagonist naltrexone suppresses overconsumption of ethanol is unclear. Oral ethanol consumption in humans increases hypothalamic-pituitary-adrenal (HPA) activity, and recent studies suggest that naltrexone may reduce ethanol consumption by modifying the HPA-stimulating effects of ethanol. The purpose of this study was to measure in rhesus monkeys the effects of ethanol and naltrexone, alone and in combination, on plasma levels of adrenocorticotropin hormone (ACTH). METHODS:: Nine adult male and female rhesus monkeys with chronic, indwelling intravenous catheters were maintained on tethers that allowed ethanol delivery and blood sampling. In one study, the monkeys received intramuscular injections of saline or 0.32 mg/kg naltrexone followed by noncontingent intravenous bolus infusions of saline or 0.3 to 1.8 g/kg ethanol. In a second study, other monkeys were given intramuscular injections of saline or 0.01 to 0.3 mg/kg naltrexone and subsequently responded on levers to receive intravenous saline or ethanol 0.03 g/kg per injection. RESULTS:: Ethanol, delivered either response contingently or noncontingently, did not produce systematic changes in ACTH plasma levels. Naltrexone alone produced increases in plasma ACTH that were attenuated by the subsequent administration of noncontingent or response-contingent ethanol. Naltrexone also produced dose-dependent reductions in intravenous ethanol self-administration. Linear regression analysis indicated that ethanol intake was negatively correlated with the plasma levels of ACTH over time. CONCLUSIONS:: The route of administration may modulate ethanol'''s effects on HPA activity. Ethanol may attenuate naltrexone'''s effect on the HPA axis by impairing HPA axis sensitivity to other stimuli. The negative correlation between ethanol intake and ACTH levels supports the notion that naltrexone'''s effect of increasing HPA axis activity may be related to its ability to suppress ethanol consumption. [ABSTRACT FROM AUTHOR]

The positive BOLD (blood oxygen level-dependent) response elicited in human visual cortex by a localized visual stimulus is accompanied by a reduction in the BOLD response in regions of the visual cortex that represent unstimulated locations in the visual field. We have suggested previously that this negative BOLD reflects attention-related suppression of neural activity, but it might also be explained in terms of “blood stealing,” i.e., hemodynamic changes that have no neural correlate. We distinguish two possible hemodynamic effects of this type: (1) blood flow reduction caused by locally reduced pressure in vessels that share their blood supply with nearby dilated vessels; and (2) blood flow reduction caused by active constriction of vessels under neural control. The first is ruled out as an explanation of negative BOLD by showing that a visual stimulus that stimulates primary visual cortex in one hemisphere can cause extensive suppression in the other hemisphere i.e., it is not a local phenomenon. Negative BOLD most likely reflects suppression of neural activity, but could also reflect an active blood flow control system. Hum. Brain Mapping 21:213–220, 2004. © 2004 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

The current techniques used to create patterned materials at the nanometer scale such as electron beam lithography are restricted to patterning small areas, which can be expensive and time consuming. A simple, cost-effective approach has been developed to create a reproducible surface topography to influence the cellular response. In this study, the cellular response of murine fibroblasts to 7, 14 and 21 nm colloidal silica particles were investigated over one, three and seven days and up to seven weeks. The surface topography and wettability of the surfaces were also studied. The results confirmed that silica particles create a nanoscale topography, which initiates a distinctive cellular response affecting the morphology, adhesion and proliferation of the fibroblasts. The effect was evident up to seven weeks with no adverse effects on cell viability. [ABSTRACT FROM AUTHOR]