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Leukocyte adhesion receptor P selectin is found on activated endothelial cell and platelet surfaces. Embryonic gene cell targeting reduces P selectin in mice, causing anomalous leukocyte activity and enhanced neutrophil levels. Neutrophil activity in the peritoneal cavity and mesenteric venule leukocyte rolling are adversely affected. Leukocyte-blood capillary wall reactions are significantly influenced by P selectin under inflammatory conditions.

This paper reports a study conducted to validate a locally created and rated writing test. The test was used to inform a higher education institution’s decisions regarding placement of entering students into appropriate preparatory English program courses. An amalgam of two influential models – Kane’s (1992, 1994) interpretive model and Bachman’s (2005) and Bachman and Palmer’s (2010) assessment use argument – was used to build a validation framework. A mixed methods approach incorporating a diverse array of quantitative and qualitative data from various stakeholders, including examinees, students, instructors, staff, and administrators, guided the collection and analysis of evidence informing the validation. Results established serious doubts about the writing test, not only in terms of interpreted score meaning, but also the impact of its use on various stakeholders, and on teaching and learning. The study reinforces the importance of comprehensive validation efforts, particularly by test users, for all instruments informing decisions about test-takers, including writing tests and other types of direct performance assessments. Results informed a number of suggested changes regarding the rubric and rater training, among others, thus demonstrating the potential of validation studies as ‘road maps’ for immediate opportunities to improve both testing and decisions made based on testing. [ABSTRACT FROM AUTHOR]

Abstract: Seasonal changes in macroinvertebrate taxon abundances that are related to life history introduce temporal variation into macroinvertebrate community structure that can potentially confound bioassessments. In this study, macroinvertebrates from three rural and three urban streams were sampled monthly to assess temporal variability in community structure, determine how taxon life-cycle seasonality affects this variability, and determine if this temporal variability confounds biotic index interpretations. Temporal variation in taxon abundances was higher in the rural streams than in the urban streams, and 17 of 23 indicator taxa from rural streams exhibited, or are known to exhibit, either fast- or slow-seasonal life cycles. Conversely, five taxa were identified as indicators for urban streams, but only two of these taxa exhibited seasonal life cycles. Further, the life-cycle seasonality of many rural stream indicator taxa appeared to be linked to the seasonality of environmental conditions such as hydrologic permanence and benthic leaf detritus availability. Macroinvertebrate bioassessment index (MBI) scores were higher in the rural streams than in the urban streams during all months except June, July, and October when no difference was detected. We attribute the reduced discriminatory power of the MBI in the summer and early autumn to the life-cycle of a single taxon (Stenelmis sp.), and its effects on % Clingers – a component metric of the MBI. Stenelmis sp. exhibited a non-seasonal life cycle with a larval development time of approximately 12 months with considerable overlapping of cohorts present during the summer and early autumn when an extended first instar recruitment period was evident. During this overlap period, urban stream MBI values increased resulting in no statistical difference in the MBI between urban and rural streams in June, July, and October. Analyses of temporal variability in taxon abundances and life-history characteristics, as completed in this study, can greatly contribute to the creation and/or validation of bioassessment protocols. [Copyright &y& Elsevier]

Fourth-order Møller–Plesset perturbation theory (MP4) and perturbation theory of intermolecular forces were employed to investigate the potential energy surface of the NH3–CO complex. Most calculations were performed using a relatively large, well-tempered basis set, though for a few selected structures an augmented basis set with bond functions was used. The global minimum of −1489 μEh was found for a bent hydrogen-bonded configuration at the intermolecular distance of 4.3 A˚. The minimum energy area was discovered to be very wide and flat making the complex extremely flexible. A model potential function for the complex was developed. [Copyright &y& Elsevier]

The optical frequency doubling properties of silver, copper, and platinum nanoparticles in aqueous solution are studied via hyper-Rayleigh scattering (HRS) spectroscopy. Substantial HRS responses are observed for silver and copper particles. The response is attributed to enhancement due to resonance of the nonlinearly scattered light with the particles'' surface plasmon absorption band. Platinum particles, which lack visible-region plasmon absorption, do not display detectable HRS signals. The largest signals from silver particles are observed under conditions of two-photon resonance, qualitatively consistent with the predictions of available theory; smaller yet still impressive signals are observed under pre- and post-resonant conditions. [Copyright &y& Elsevier]

Gold-core/silver-shell nanoparticles featuring core diameters of 13 or 25 nm were prepared in aqueous solution. Silver-coated gold nanoparticles have two distinct plasmon absorption bands whose relative intensities depend on the shell thickness – features that are captured well by classical Mie theory. The core/shell spectra are not simply linear combinations of the pure-component spectra. Theory shows that shell dielectric effects upon the core can cause broadening, shifting, and, in some cases, damping of dominant extinction spectral features. Preliminary studies show that core–shell particles are reasonably efficient hyper-Rayleigh scatterers under conditions of two-photon resonance or near resonance with a high-energy plasmon band. [Copyright &y& Elsevier]

The fasting amino acid profile in 22 healthy young men aged 25-35 y (group A) was compared with the fasting profile in 21 healthy independent men aged 65-85 y (group B), in 23 orally-fed nursing home men with dementia aged 65-92 y (group C), and in 17 tube-fed nursing home men with dementia aged 65-88 y (group D). Groups B, C, and D had significantly (p < 0.05) lower levels of methionine and branched-chain amino acids than group A. Methionine was significantly lower in groups C and D than in group B. The ratio of essential to nonessential amino acids was significantly lower in groups B, C, and D than in group A. The data suggest that the intake of essential amino acids may often be suboptimal in both independent and institutionalized elderly men. [ABSTRACT FROM AUTHOR]

Forty-seven tube-fed nursing home patients were investigated with regard to serum or plasma selenium (Se), carnitine, and red blood cell (RBC) glutathione peroxidase (GSH-Px). Thirty-six patients were tube fed with Isocal®, and 11 were tube fed with Compleat B®, an L-carnitine-containing formula. Eighteen elderly nursing home patients and 10 young adults served as controls. Serum Se and plasma carnitine were lowest (p <0.05) in the Isocal patients. In all 36 Isocal® subjects, Se was below normal, and in 26% of Isocal® patients RBC GSH-Px was also below normal. Free and total carnitine were below normal in most Isocal subjects. All 11 Compleat B® patientshad subnormal serum Se, but most had normal carnitine concentrations. These data suggest that enteral formulae in nursing homes should contain > 100 μg Se and on the order of a mmol carnitine/1600 kcal. [ABSTRACT FROM AUTHOR]

Human allogeneic islet transplantation (ITx) is emerging as a promising treatment option for qualified patients with type 1 diabetes. However, widespread clinical application of allogeneic ITx is hindered by two critical barriers: the need for systemic immunosuppression and the limited supply of human islet tissue. Biocompatible, retrievable immunoisolation devices containing glucose-responsive insulin-secreting tissue may address both critical barriers by enabling the more effective and efficient use of allogeneic islets without immunosuppression in the near-term, and ultimately the use of a cell source with a virtually unlimited supply, such as human stem cell-derived β-cells or xenogeneic (porcine) islets with minimal or no immunosuppression. However, even though encapsulation methods have been developed and immunoprotection has been successfully tested in small and large animal models and to a limited extent in proof-of-concept clinical studies, the effective use of encapsulation approaches to convincingly and consistently treat diabetes in humans has yet to be demonstrated. There is increasing consensus that inadequate oxygen supply is a major factor limiting their clinical translation and routine implementation. Poor oxygenation negatively affects cell viability and β-cell function, and the problem is exacerbated with the high-density seeding required for reasonably-sized clinical encapsulation devices. Approaches for enhanced oxygen delivery to encapsulated tissues in implantable devices are therefore being actively developed and tested. This review summarizes fundamental aspects of islet microarchitecture and β-cell physiology as well as encapsulation approaches highlighting the need for adequate oxygenation; it also evaluates existing and emerging approaches for enhanced oxygen delivery to encapsulation devices, particularly with the advent of β-cell sources from stem cells that may enable the large-scale application of this approach. Unlabelled Image [ABSTRACT FROM AUTHOR]