cssi/SciSciGPT-SciSciNet huggingface dataset:
PdE-based model reference adaptive control of uncertain heterogeneous multiagent networks

Robust globally stable model reference adaptive control (MRAC) laws recently derived for systems described by parabolic and hyperbolic partial differential equations (PDEs) with spatially-varying coefficients under distributed sensing and actuation are extended to heterogeneous multiagent networks characterized by parameter uncertainty. The extension is carried out using partial difference equations (PdEs) on graphs that preserve parabolic- and hyperbolic-like cumulative network behavior. Unlike in the PDE case, only boundary input is specified for the reference model. The algorithms proposed directly incorporate this boundary reference input into the reference PdE to generate the distributed admissible reference evolution profile followed by the agents. The agent evolution thus depends only on the interaction with the adjacent agents, making the system fully decentralized. Numerical examples are presented as well, including the case of the switched topology associated with a sudden loss of an agent. The resulting PdE MRAC laws inherit the robust linear structure of their PDE counterparts.
Post-traumatic stress disorder in the community: an epidemiological study

Post-traumatic stress disorder (PTSD) was studied in the Piedmont region of North Carolina. Among 2985 subjects, the lifetime and six month prevalence figures for PTSD were 1.30 and 0.44% respectively. In comparison to non-PTSD subjects, those with PTSD had significantly greater job instability, family history of psychiatric illness, parental poverty, child abuse, and separation or divorce of parents prior to age 10. PTSD was associated with greater psychiatric comorbidity and attempted suicide, increased frequency of bronchial asthma, hypertension, peptic ulcer and with impaired social support. Differences were noted between chronic and acute PTSD on a number of measures, with chronic PTSD being accompanied by more frequent social phobia, reduced social support and greater avoidance symptoms. Language: en
Fluid balance and endurance exercise performance

Dehydration alters cardiovascular, thermoregulatory, central nervous system, and metabolic functions. One or more of these alterations will degrade endurance exercise performance when dehydration exceeds 2% of body weight. These performance decrements are accentuated by heat stress. To minimize the adverse consequences of body water deficits on endurance exercise performance, it is recommended that fluid intake be sufficient to minimize dehydration to less than 2% of body weight loss. This can usually be achieved with fluid intakes of under 1 L x h(-1).
Dynamics of the formation of Bragg gratings in germanosilicate optical fibers

Abstract The dynamics of the formation of Bragg gratings in germanosilicate optical fibers is examined using a material rate equation coupled to spatio-temporally evolving counter-propagating light fields. Theories for the microscopic material changes which give rise to the index change are discussed and the differential equations describing the process are numerically integrated to yield solutions for the evolution of a dynamic grating and the counter-propagating electric fields. Results for the time dependent reflectivity are compared with previously reported experimental findings.
Gender Differences in Risk and Protective Factors for Alcohol Use and Substance Use Problems among Hispanic Adolescents

This study investigates gender differences within the context of risk and protective factors for alcohol use and substance use problems in a sample of 8,992 Hispanic students in grades 6 through 12, who responded to a statewide survey of alcohol and other drug use. The effects of gender, grade, and risk and protective factors on past-month alcohol use, binge drinking, and risk for substance use problems are examined. Results show that outcomes were moderated by gender, such that females had greater predicted probabilities than males for alcohol use, binge drinking, and risk for substance use problems across levels of risk and protective factors. An ecological framework is applied to speculate why Hispanic female adolescents were more vulnerable than their males to problem alcohol use.
Application of a time-dependent, distorted initial-state wave function in calculations of K-shell ionization

Initial- and final-state distorted wave functions, which in the semiclassical approximation depend upon projectile position and, hence, also upon time, are considered in the context of K-shell ionization. The use of such time-dependent wave functions can lead to the occurrence of nonorthogonal basis states. Issues associated with constructing the scattering amplitude in the presence of such states are identified and discussed. The incorporation of a time-dependent, distorted initial-state wave function along with a time-dependent binding energy is shown to give rise at low velocities to a large enhancement in the total K-shell ionization cross section over what is obtained with a time-independent wave function. The system studied is that of 3He incident on Ti in the energy region 0.2 to 1.6 MeV/u. This enhancement effectively cancels a corresponding large reduction which is found to occur from the use of a time-dependent vs a time-independent binding energy.
Short-range homing in the house mouse, Mus musculus: stages in the learning of directions

Abstract Abstract. Female house mice readily learn to retrieve their pups 50 cm from the centre of an open arena and take them to their nest outside the arena's periphery. Experimental manipulation to reveal the spatial-orientation constituents of this behaviour disclosed thus submechanisms. Guided orientation, the direct response to objects. Path integration, the continuous monitoring of spatial displacements combined with computation of the locomotor vector to the starting point of the path. Landmark navigation, the movement by means of distal visual cues toward a goal not directly perceived. Learning to home passes through three stages. First, the exploring mouse is directly guided to objects of interest. Second, the homing mouse adds path integration; that is, it keeps a running, integrated spatial record derived from locomotion. Finally (circumstances permitting) the homing mouse links path integration with spatial references to distal visual landmarks. Sparse comparative evidence from other species of rodents suggests that such a system of short-range topographical orientation is universal among rodents.
PERCEPTION OF OPENNESS, TRUSTWORTHINESS, AND OTHER CHARACTERISTICS IN FACIAL PHOTOGRAPHS

25 males and 25 females (Study I) and 37 males (Study II) Q-sorted 60 facial photographs according to perceived openness (PO) and perceived trustworthiness (PT). In Study II subjects also responded to Shostrom's Personal Orientation Inventory. Trustworthiness was, but openness was not, perceived as stereotypically as were other traits in previous studies. Both perceived openness and trustworthiness were less highly correlated with other positively valued traits than these traits had been found to correlate with one another; but the latter was more highly correlated negatively with perceived hostility than this trait had been found to correlate with other desirable traits. Individual fs between openness and trustworthiness were found to be unrelated to scores on the Personal Orientation Inventory.
A systematic review of advance practice providers in acute care: Options for a new model in a burn intensive care unit

Introduction Accreditation Council for Graduate Medical Education mandated work-hour restrictions have negatively impacted many areas of clinical care, including management of burn patients, who require intensive monitoring, resuscitation, and procedural interventions. As surgery residents become less available to meet service needs, new models integrating advanced practice providers (APPs) into the burn team must emerge. We performed a systematic review of APPs in critical care questioning, how best to use all providers to solve these workforce challenges? Methods We performed a systematic review of PubMed, CINAHL, Ovid, and Google Scholar, from 2002 to 2012, using the key words: nurse practitioner, physician assistant, critical care, and burn care. After applying inclusion/exclusion criteria, 18 relevant articles were selected for review. In addition, throughput and financial models were developed to examine provider staffing patterns. Results Advanced practice providers in critical care settings function in various models, both with and without residents, reporting to either an intensivist or an attending physician. When APPs participated, patient outcomes were similar or improved compared across provider models. Several studies reported considerable cost-savings due to decrease length of stay, decreased ventilator days, and fewer urinary tract infections when nurse practitioners were included in the provider mix. Conclusions Restrictions in resident work-hours and changing health care environments require that new provider models be created for acute burn care. This article reviews current utilization of APPs in critical care units and proposes a new provider model for burn centers.
Diplopia and loss of accommodation due to chloroquine.

Impaired visual accommodation is a frequently occurring complication of chloroquine therapy. The present report describes a patient whose ocular function was assessed serially during chloroquine administration. Impaired convergence and loss of accommodative amplitude developed several weeks after beginning chloroquine treatment; the magnitude of these alterations in ocular function was dose related. Chloroquine-induced changes persisted during therapy, but ocular function returned to pretreatment limits 1 week after discontinuing the drug.
A possible EMB award recognizing excellent research by graduate students published in EMB journals

The submission and publication of excellent papers is fundamental to academic work of high quality. This is a discussion of a hypothetical award for BME graduate students who publish work in an EMB Journal.
Piaget's theory and instruction: How compatible are they?

Abstract Three views of the compatibility of Piaget's theory and educational practice are considered: (a) it is a useful framework to guide instruction; (b) it is antithetical or unrelated to the goals of instruction; and (c) there are some instructional features of the theory that can be operationalized and studied empirically. The findings of such studies are briefly discussed, and in general, more research is deemed needed to establish the validity of Piaget's most educationally relevant constructs. Some general features of Piaget's theory that have attracted teachers are described, and the implications of Piaget's more recent theoretical emphasis on social factors such as conflict are considered.
The use of green-stained wood caused by the fungus Chlorociboria in Intarsia Masterpieces from the 15th century

Green-stained wood from one of the intarsia panels of the Gubbio studiolo (Italy, 15th century, in the collection of The Metropolitan Museum of Art, New York) and an intarsia panel made by Fra Giovanni da Verona (Italy, around 1500, in the collection of the Historical Museum of Amsterdam), were sectioned and examined by light, scanning and transmission electron microscopy, and energy dispersive x-ray microanalyses. Sections of green-stained wood from the intarsia panels contained evidence of fungal hyphae in vessels, fibers, and parenchyma cells. Colored deposits that were yellowish-orange or green were found to be extensive in ray parenchyma cells and in vessels and fibers adjacent to the ray parenchyma. The staining pattern within the wood was concentrated in areas where fungal hyphae were present. The woods were identified as Populus sp. No fungi were evident in samples obtained from other woods ( Quercus sp. and Juglans sp.) adjacent to the green-colored wood within the artwork. X-ray microanalyses of the green wood showed no evidence of high concentrations of metal ions that would be present if inorganic dyes were used. Transmission electron microscopy showed the ultrastructural distribution of fungal hyphae and pigmented substances within the woody cells as well as an erosion of the secondary wall layers in some cells. A comparative study of recently collected green-stained wood caused by the fungus Chlorociboria (syn. Chlorosplenium ), showed that the micromorphology of fungal colonization and pigment deposition was identical to the patterns observed in the green wood of the 500-year-old intarsia panels.
The crystal structure of a new ternary metal-rich sulfide Ta6.08Nb4.92S4

Abstract The metal-rich sulfide Ta6.08Nb4.92S4 has been prepared by high temperature techniques and characterized by means of X-ray diffraction experiments. It crystallizes in the orthorhombic space group Pnma with four formula units in the cell: a = 3121.00 (54) pm, b = 335.07 (7) pm, and c = 959.18 (19) pm. Its structure is similar to that of niobium-rich sulfides, rather than to that of tantalum-rich sulfides. The metal coordinations are capped distorted cubic prisms and the coordinations of sulfur are capped trigonal prisms.
When to Start Antiretroviral Therapy

Antiretrovirals perform superbly in combating HIV infection. But when to initiate therapy in asymptomatic, nonpregnant, hepatitis-free, HIV-infected persons is not securely established. Of two completed randomized trials using modern therapy, a Haitian trial demonstrated a benefit to initiating therapy between 200 and 350 CD4 cells/mm3 as compared with less than 200 CD4 cells/mm3 and an international trial demonstrated a benefit to starting at greater than 350 CD4 cells/mm3 as compared with less than 250 CD4 cells/mm3. Many observational cohorts support initiating treatment at less than 350 CD4 cells/mm3. Of these, three large studies supported initiation at less than 350 cells/mm3, less than 450 CD4 cells/mm3, and less than 500 CD4 cells/mm3, respectively, but only the last supported starting at higher counts. Such studies are not probative, given the problem of confounding. No conventional antiretroviral regimen is free of long-term adverse effects, especially over decades of use. All are expensive and require expensive monitoring. When resources are restricted, initiation of antiretrovirals for persons with high CD4 count diverts treatment from more needy persons. Pathophysiological considerations favor universal treatment because antiretrovirals mitigate systemic inflammation, which aggravates atherosclerosis. There are suggestions that HIV hastens the natural decline of cognitive, renal, and pulmonary function as well as bone mineral loss; the mechanism(s) are uncertain, as is the ability of antiretrovirals to counteract the probable acceleration. The four major guideline panels, although all have issued updates in the past year, are not consistent in recommendations for treatment of HIV-infected persons with counts greater than 350 CD4 cells/mm3.
Potential Role Of The Peroxynitrite-poly(adp-ribose) Synthetase Pathway In A Rat Model Of Severe Hemorrhagic Shock

Peroxynitrite (a potent oxidant produced by nitric oxide and superoxide) and hydroxyl radical, reactive oxidants produced during hemorrhagic shock, are potent triggers of DNA single-strand breakage. DNA injury triggers the activation of the nuclear enzyme poly(ADP-ribose) synthetase (PARS), which contributes to cellular injury. Hemorrhagic shock is associated with early vasomotor paralysis as well as with early derangements in the cellular metabolic status. Here we have tested whether activation of PARS contributes to the vasodilatation and early mortality in a rat model of severe hemorrhagic shock. In anesthetized rats hemorrhaged to a mean arterial blood pressure of 35 mmHg, pretreatment with the PARS inhibitor 5-iodo-6-amino-1,2-benzopyrone significantly improved survival rate. Furthermore, an inhibitor of nitric oxide biosynthesis (N G -metnyl-L-arginine) and the cell-permeable superoxide dismutase mimetic Mn(III)tetrakis(4-benzoic acid) porphyrin also offered a significant protection in terms of hypotension and acute mortality. However, the selective inhibitor of the inducible nitric oxide synthase, mercaptoethylguanidine, failed to affect blood pressure or mortality. The present data suggest that PARS activation plays a role in the pathophysiology of hemorrhagic shock. Early production of peroxynitrite (produced by nitric oxide from constitutive nitric oxide synthase) and hydroxyl radical may induce DNA single-strand breakage, which is the immediate trigger of PARS activation.
Changes in oxygen consumption and nitrogen metabolism in the dragonfly Somatochlora cingulata exposed to aluminum in acid waters

Oxygen consumption, ammonia excretion and changes in O:N ratios by the dragonfly Somatochlora cingulata were measured in four nymphal growth stages, relative to aluminum concentrations and low pH. A differential reduction in respiration and ammonia excretion rates resulted in an increase in ON ratios for all nymphal stages. The earlier stages, however, were the most sensitive. The ratios obtained were indicative of a decreased dependence on protein reserves and increased utilization of carbohydrates or lipid reserves. Also observed was an increase in the haemolymph pH and glutamate levels with a concomitant accumulation of tissue ammonia.
DNA sequence and haplotype variation in two candidate genes for dilated cardiomyopathy in the turkey Meleagris gallopavo

Determining variation in genes is fundamental to understanding their function in the disease state. Cardiac tro- ponin T (cTnT) and phospholamban (PLN) genes have been implicated in dilated cardiomyopathy (DCM) in human and model species. To investigate the role of these 2 candidate genes in DCM in the turkey Meleagris gallopavo, understand- ing sequence variants and map position distribution is necessary. To this end, a total of 1854 and 1771 bp of cTnT and PLN gene sequences, respectively, were scanned for single nucleotide polymorphisms (SNPs) in a randomly bred popula- tion. A total of 15 SNPs was identified in the cTnT and PLN genomic sequences. Nine haplotypes, 5 in cTnT and 4 in PLN, were identified. Observed heterozygosities (0.02-0.39) in the turkey population were low for both genes. Within each gene, 1 SNP corresponding to a restriction enzyme site was identified and used to develop a PCR-restriction frag- ment length polymorphism (RFLP) genotyping assay. The PLN gene was genetically mapped to turkey chromosome 2, equivalent to Gallus gallus chromosome 3, and cTnT mapped to a turkey microchromosome. Although limited because of the relatively small sample size of 55 birds, the data from this SNP analysis of PLN and cTnT provide a foundation from which to evaluate the function of cTnT and PLN in the turkey. Information about the distribution of the SNPs and haplo- types will facilitate future association and linkage studies.
Electronic structure, geometry, and energetics of carbanion and carbocation of [1.1] ferrocenophane: an INDO study

INDO-SCF calculations with constrained geometry optimization have been performed to determine the bridge geometries in [1.1]ferrocenophane and its carbocation and carbanion to address the question of possible C-H-C hydrogen bonding in the carbanion derivative. In the equilibrium geometry of the carbanion, the endo-hydrogen is bonded to one of the bridge carbon atoms and the calculated distance between the two bridge carbons seems too large to accommodate a stable C-H-C hydrogen bond. The results indicate that the observed proton NMR spectrum of carbanion should be interpreted in terms of rapid proton exchange between two bridge carbon atoms rather than a symmetric hydrogen bond. The ground state charge distributions show that the ionic bridges in both carbanion and carbocation are highly conjugated and most of the ionic charge in both molecules is distributed over the ferrocene ring system. The charge on the iron varies only slightly among the three molecules and the formal oxidation state of iron remains +2. The role of the iron seems to be that of a conduit for charge transfer between ferrocene rings upon conjugation.
Spatio-temporal features of periodic oxidation of H2 and CO on Pt/CeO2/Al2O3

Abstract Infrared measurements reveal that cyclic shifts between lean and rich (H 2 and/or CO) feeds to a Pt/CeO 2 /Al 2 O 3 monolith catalyst generate complex, spatio-temporal temperature features. A sharp temperature rise occurs in the upstream of the monolith shortly after the cyclic introduction of either H 2 /CO to a pre-oxidized catalyst or O 2 to a pre-reduced catalyst. This initial upstream temperature rise following the reduction of oxygen stored on a pre-oxidized catalyst is higher than following the oxidation of either H 2 or CO (or their mixture) stored on the monolith. The upstream hot zone temperature decreases with time without forming a downstream moving temperature front. The intricate transient temperature gradients are caused by a competition between the chemical and transport rate process. However, the effluent concentrations do not reflect these complex interactions. Only about 20% of the total oxygen trapped during the pre-oxidation with a 5% O 2 /N 2 mixture at 350 °C is strongly bound or chemisorbed. Most of the oxygen that reacts at high temperature is loosely-bound. The introduction of a nitrogen sweep flow between the lean and rich feeds removes a significant amount of the loosely held oxygen, leading to a much more uniform reduction. Inadequate resolution of the spatio-temporal phenomena may lead to a misinterpretation of the apparent kinetics. The spatial features of the thermal fronts of the two reductants (CO or H 2 ) are similar. The amplitude of the hot spot of the two reactants differ due to differences in the temperature dependencies of their oxidation rates. The transient oxidation of CO/H 2 mixtures reveal H 2 enhanced CO oxidation is likely due to a kinetic interaction as seen in previous steady-state studies.
The role of Pd-alumina catalyst in the dehydrogenation of cyclohexane

Abstract To study the dehydrogenation of cyclohexane to benzene in the presence of Pd-alumina at 175–210 °C, it was tentatively assumed that the reaction proceeds via a mechanism whose slow step is a monomolecular decomposition of reactant on the catalyst surface. An apparent value of the site density was then calculated, using transition state theory and the observed, zero order reaction rate and activation energy (15.5 kcal mole −1 ). The value obtained, ~10 9 sites cm −2 , seems to be unrealistically low in view of other results on similar systems. Even though the tentative model is probably incorrect, the calculation does aid in elucidation of the reaction. Thus, it is shown that the reaction is much more complicated than suggested by the model and the results are consistent with evidence that; cyclohexene is a necessary intermediate.
High-resolution time-series data for 1991/1992 primary production and related parameters at a Palmer LTER coastal site: implications for modeling carbon fixation in the Southern Ocean

Our goal was to provide a high-resolution temporal data base for modeling primary production in shelf waters adjacent to Palmer Station, Antarctica. Here, the resulting 1991/1992 data base is used to: (1) determine in situ productivity over a range of seasonal to subseasonal time scales; (2) identify time scales of significant variability in marine productivity during the peak growing season; (3) identify environmental, experimental and analytical factors that can significantly impact the accuracy of daily, weekly and seasonal productivity estimates; and (4) integrate our findings with previous studies of Antarctic coastal primary pro- duction. Data were gathered every 2–3 days during a 3-month period in the austral spring/summer of 1991/1992. Photosynthesis-irradiance (P-I) relationships were determined throughout the euphotic zone and P-I parameters, combined with knowledge of the in-water light field, were used to derive instantaneous rates of in situ primary production. Additionally, weekly samples were collected from surface and chlorophyll a maxima for characterization of the patterns of diel periodicity in P-I parameters. Seven diel patterns were discerned over the season and used to time-correct instantaneous measurements and derive noontime, daily, monthly and seasonally integrated estimates of production. During the season, a large bloom was responsible for some of the highest daily produc- tivity rates reported for the Southern Ocean (0.8 g C m-3 d-1, 6.3 g C m-2 d-1). Significant variation in daily integrated rates occurred generally on time scales less than a week. Peak timing and magnitude of daytime periodicities in photosynthesis varied widely over the season, closely coupled to changes in phytoplankton community composition. Instantaneous measurements of primary production, if uncorrected or improperly corrected for daytime periodicities in carbon fixation, were unreliable predictors of production on longer time scales even if the water column was sampled every few days. High frequency sampling and consideration of diel periodicity may be requirements when attempting to discern differences between short time-scale variability and long-term trends in Antarctic primary production.
Tradeoffs between lidar pulse density and forest measurement accuracy

Abstract Discrete airborne lidar is increasingly used to analyze forest structure. Technological improvements in lidar sensors have led to the acquisition of increasingly high pulse densities, possibly reflecting the assumption that higher densities will yield better results. In this study, we systematically investigated the relationship between pulse density and the ability to predict several commonly used forest measures and metrics at the plot scale. The accuracy of predicted metrics was largely invariant to changes in pulse density at moderate to high densities. In particular, correlations between metrics such as tree height, diameter at breast height, shrub height and total basal area were relatively unaffected until pulse densities dropped below 1 pulse/m2. Metrics pertaining to coverage, such as canopy cover, tree density and shrub cover were more sensitive to changes in pulse density, although in some cases high prediction accuracy was still possible at lower densities. Our findings did not depend on the type of predictive algorithm used, although we found that support vector regression (SVR) and Gaussian processes (GP) consistently outperformed multiple regression across a range of pulse densities. Further, we found that SVR yielded higher accuracies at low densities ( 1 pl/m2). Our results suggest that low-density lidar data may be capable of estimating typical forest structure metrics reliably in some situations. These results provide practical guidance to forest ecologists and land managers who are faced with tradeoff in price, quality and coverage, when planning new lidar data acquisition.
P04.11. Factors associated with willingness to participate in a yoga clinical trial among breast cancer survivors

Methods We performed a cross-sectional survey study at an urban academic cancer centre among outpatient postmenopausal women with stage 0 to III breast cancer receiving adjuvant aromatase inhibitor (AI) therapy. Self-reported WTP in a yoga trial was the main outcome variable. Perceived barriers to WTP were collected along with sociodemographic and clinical variables. Multivariate logistic regression was used to identify factors associated with WTP.
The Problem of the Identity of Eirenaeus Philalethes

(1964). The Problem of the Identity of Eirenaeus Philalethes. Ambix: Vol. 12, No. 1, pp. 24-43.
DOES NICHE CONSERVATISM PROMOTE SPECIATION? A CASE STUDY IN NORTH AMERICAN SALAMANDERS

Recent speciation research has generally focused on how lineages that originate in allopatry evolve intrinsic reproductive isolation, or how ecological divergence promotes nonallopatric speciation. However, the ecological basis of allopatric isolation, which underlies the most common geographic mode of speciation, remains poorly understood and largely unstudied. Here, we explore the ecological and evolutionary factors that promote speciation in Desmognathus and Plethodon salamanders from temperate eastern North America. Based on published molecular phylogenetic estimates and the degree of geographic range overlap among extant species, we find strong evidence for a role for geographic isolation in speciation. We then examine the relationship between climatic variation and speciation in 16 sister-taxon pairs using geographic information system maps of climatic variables, new methods for modeling species' potential geographic distributions, and data on geographic patterns of genetic variation. In contrast to recent studies in tropical montane regions, we found no evidence for parapatric speciation along climatic gradients. Instead, many montane sister taxa in the Appalachian Highlands inhabit similar climatic niches and seemingly are allopatric because they are unable to tolerate the climatic conditions in the intervening lowlands. This temporal and spatial-ecological pattern suggests that niche conservatism, rather than niche divergence, plays the primary role in promoting allopatric speciation and montane endemism in this species-rich group of vertebrates. Our results demonstrate that even the relatively subtle climatic differences between montane and lowland habitats in eastern North America may play a key role in the origin of new species.
Gun Carrying by High School Students in Boston, MA: Does Overestimation of Peer Gun Carrying Matter?.

This paper investigates: (1) whether high school students overestimate gun carrying by their peers, and (2) whether those students who overestimate peer gun carrying are more likely to carry firearms. Data come from a randomly sampled survey conducted in 2008 of over 1700 high school students in Boston, MA. Over 5% of students reported carrying a gun, 9% of boys and 2% of girls. Students substantially overestimated the percentage of their peers who carried guns; the likelihood that a respondent carried a gun was strongly associated with their perception of the level of peer gun carrying. Most respondents believed it was easier for other youth to obtain guns than it was for them. Social marketing campaigns designed to lower young people's perceptions about the prevalence of peer gun carrying may be a promising strategy for reducing actual gun carrying among youth. Language: en
A viewpoint on statin effects − benefits and problems.

Perhaps acetylsalicylic acid was the first blockbuster medication, but in the modern era of cardiovascular (CV) medicine, statins are the major blockbuster medical treatment. The practice of state-of-the-art cardiology and other types of CV medicine depends on these incredible compounds with many intriguing effects. Five key placebo-controlled trials proved the benefit of statins in reducing myocardial infarctions, coronary artery disease (CAD) mortality and, to some extent, overall mortality (1–5). Nevertheless, much is left to be understood and accomplished because approximately 60% of patients treated with statins did not have a beneficial reduction in CV events. This 60% deficit of reduction in CV events and CAD complications may involve noted favourable risk modifiers such as high-density lipoprotein (HDL).
Revisiting population size vs. phoneme inventory size

In this discussion note we argue against the findings presented in Hay & Bauer 2007, which show a positive correlation between population size and phoneme inventory size. We argue that the positive correlation is an artifact of the authors’ statistical technique and biased data set. Using a hierarchical mixed model to account for genealogical relatedness of languages, and a much larger and more diverse sample of the world’s languages, we find little support for population size as an explanatory predictor of phoneme inventory size once the genealogical relatedness of languages is accounted for.
Membrane Geometry Alters the Interaction between Islet Amyloid Polypeptide and Lipid Bilayers

Islet amyloid polypeptide (IAPP) is a small, amyloidogenic peptide associated with the pathology of Type 2 Diabetes. In vitro, the presence of anionic lipids significantly enhances the amyloidogenic behavior of IAPP. Moreover, IAPP causes leakage of synthetic lipid vesicles, as well as cell death when added exogenously to cultured mammalian cells. In order to probe the mechanism by which IAPP disrupts lipid bilayers, we have studied its interactions with two different model membranes-Nanodiscs and vesicles-using a combination of fluorescence correlation spectroscopy (FCS) and ensemble fluorescence measurements. We find that IAPP binds to these two model systems with different affinities. Our results illustrate that different membrane geometries modulate the interaction of IAPP with lipid bilayers, and therefore, may affect both amyloid formation and membrane leakage.
INVASION BY A N2-FIXING TREE ALTERS FUNCTION AND STRUCTURE IN WET LOWLAND FORESTS OF HAWAII

Invasive species pose major threats to the integrity and functioning of ecosystems. When such species alter ecosystem processes, they have the potential to change the environmental context in which other species survive and reproduce and may also facilitate the invasion of additional species. We describe impacts of an invasive N2-fixing tree, Falcataria moluccana, on some of the last intact remnants of native wet lowland forest undergoing primary succession on 48-, 213-, and 300-yr-old lava flows of Kilauea Volcano on the island of Hawai‘i. We measured litterfall, soil nitrogen (N) and phosphorus (P) availability, light availability, species composition, and forest structure in native-dominated stands and in stands invaded by Falcataria. Litter inputs increased 1.3–8.6 times, N mass of litterfall increased 4–55 times, and P mass of litterfall increased 2–28 times in invaded stands relative to native stands. C:N and C:P ratios of litterfall were lower, and N:P ratios higher, in invaded stands relative to native stands. Resin-captured soil N and P values were 17–121 and 2–24 times greater, respectively, in invaded stands relative to native stands on each of the three lava flows. Native species accounted for nearly 100% of total basal area and stem density in native stands, while alien species accounted for 68– 99% of total basal area, and 82–91% of total stem density, in invaded stands. Compositional changes following Falcataria invasion were due both to increases in alien species, particularly Psidium cattleianum, and decreases in native species, particularly Metrosideros polymorpha. Results provide a clear example of how invasive tree species, by modifying the function and structure of the ecosystems that they invade, can facilitate invasion by additional nonnative species and eliminate dominant native species. Given the rarity and limited extent of remaining native-dominated wet lowland forests in Hawaii, and the degree to which Falcataria invasion alters them, we expect that the continued existence of these unique ecosystems will be determined, in large part, by the spread of this invasive species.
Phenotypic complementation of ms45 maize requires tapetal expression of MS45

A mutation in the maize Ms45 gene results in a male-sterile phenotype due to the absence of pollen. Cytological examination of microspores in ms45 mutant plants reveals that the cell wall of the developing male gametophyte is poorly formed, while genetic analysis indicates that mutations at Ms45 are sporophytic. The Ms45 gene has been isolated by transposon tagging and transcription was shown by RNA hybridization analysis to be tassel-specific. In this report, an efficient system for molecular complementation is described and used to confirm that a transformed copy of the wild-type gene was able to fully restore fertility to ms45 mutant maize and to characterize MS45 protein expression in maize anthers. The MS45 protein was localized to the tapetum and expressed maximally during the early-vacuolate microspore stage of development. Based on these observations, phenotypic complementation of ms45 was used as an assay to determine tapetal cell-layer activity of other anther-specific and constitutive promoters.
The transport of organelles in axons

Abstract The fast anterograde and retrograde transport systems in axons convey organelles from the soma, where synthesis occurs, to the synaptic region and back. Studies of label incorporation into newly synthesized organelles show that they move along the axon with profiles resembling traveling waves. The underlying mechanism appears to be that cross-bridging “engines” attach to the organelles and this complex then attaches by the engines to the surface of microtubules, resulting in translocation of the organelles. A model incorporating this mechanism predicts traveling-wave-like profiles of labeled organelles and can serve to link mechanistic information with fast transport measurements in intact axons. Analysis of the simplest case provides insight into the factors determining the speed and shape of the wavelike profile.
Influence of non-specific binding on antigen-antibody binding kinetics for biosensor applications

Abstract A theoretical analysis is presented for the influence of non-specific binding on the specific binding of antigen in solution to antibody immobilized on a biosensor surface for first-, one and a half-, second-, and other-order reactions occurring under external diffusion-limited conditions. Both single-step and dual-step binding of antigen to antibody are considered. An increase in α (the ratio of non-specific binding to specific binding) and an increase in the forward binding rate coefficient leads to a decrease in the normalized antigen concentration near the surface, c s / c 0 and in the amount of antigen bound specifically to the antibody immobilized on the surface, Γ Ag s / c 0 for a first-order reaction. The presence of non-specific binding complicates the influence of the forward binding rate coefficient, k f s on the Γ Ag s / c 0 amount for the one and a half- and second-order reactions. Apparently, there is an optimum value of k f s that leads to the maximum amount of antigen that can be specifically bound to an antibody immobilized on the surface. The Γ Ag s / c 0 value is rather sensitive to the order of reaction, and decreases considerably (by orders of magnitude) as one goes from first- to one and a half-, and to second-order reactions. Temporal forward binding rate coefficients more correctly represent the complexities and heterogeneities involved during the binding of antigen in solution to the antibody immobilized on the surface. The inclusion of non-specific binding along with temporal forward binding (increasing as well as decreasing) rate coefficients in the analysis provide a more realistic picture of the binding of the antigen in solution to the antibody immobilized on the surface. This should considerably assist in the control and manipulation of these interactions at the surface.
Costs of resistance

Studies of the reduction of fitness in plants expressing resistance characteristics have always been popular. New techniques for manipulating defense expression have recently resulted in a greater understanding of the mechanisms through which different types of resistance strategies produce costs, especially those costs associated with inducible defenses.
Survival-fixation of the cochlea: a technique for following time-dependent degeneration and repair in noise-exposed chinchillas

To minimize problems with data interpretation due to interanimal variation in susceptibility to noise, we developed a survival-fixation paradigm which involves fixing one cochlea of an experimental chinchilla at one post-exposure time and fixing the second cochlea as much as 14-24 days later. This paradigm is analytically effective because there is a high correlation in the magnitude and pattern of damage in the left and right cochleas of binaurally exposed animals. Thus, each experimental animal provides two snapshots in the degeneration and repair continua in which it can be certain that both cochleas sustained equivalent amounts of damage during the exposure. Using this technique, the time course of degeneration of different structures and cells in the organ of Corti can be determined and primary damage can be distinguished from secondary effects. The present paper discusses the issues which had to be addressed to develop this technique and provides preliminary results from chinchillas exposed to a traumatic noise.
Geosmin Production by Cyanobacteria (Blue‐green Algae) in Fish Ponds at Auburn, Alabama

Studies on production of geosmin, the compound responsible for earthy-muddy flavor in water and fish, were carried out at the Auburn University Fisheries Research Station. Water was collected from ponds during 44 cyanobacterial bloom periods from April to September. Geosmin (trans-1, 10-dimethyl-trans-9-decalol) was detected at levels averaging 4.77 μg/L when Anabaena species with straight trichomes were predominant. Lower geosmin concentrations were associated with blooms of Anabaena species with coiled trichomes, Microcystis aeruginosa, and Aphanizomenon flos-aquae, and averaged 0.24, 0.12, and 0.07 μg/L, respectively. Study of four Anabaena blooms over a period of 4–8 weeks showed that changes in geosmin were correlated significantly with changes in trichome abundance. Geosmin disappeared from the water in seven days when Anabaena died. Comparison of geosmin concentrations in raw and filtered water showed that, on average, 90% of the geosmin could be associated with the particulate fraction. Dissolved geosmin concentrations ranged from 0.07–0.85 μg/L.
HTLV-1 Tax mutants that do not induce G1 arrest are disabled in activating the anaphase promoting complex.

HTLV-1 Tax is a potent activator of viral transcription and NF-κB. Recent data indicate that Tax activates the anaphase promoting complex/cyclosome (APC/C) ahead of schedule, causing premature degradation of cyclin A, cyclin B1, securin, and Skp2. Premature loss of these mitotic regulators is accompanied by mitotic aberrations and leads to rapid senescence and cell cycle arrest in HeLa and S. cerevisiae cells. Tax-induced rapid senescence (tax-IRS) of HeLa cells is mediated primarily by a dramatic stabilization of p27 KIP and is also accompanied by a great surge in the level of p21 CIP1 mRNA and protein. Deficiencies in p27 KIP prevent Tax-IRS. A collection of tax point mutants that permit normal growth of S. cerevisiae have been isolated. Like wild-type tax, many of them (C23W, A108T, L159F, and L235F) transactivate both the HTLV-LTR and the NF-κB reporters. One of them, V19M, preferentially activates NF-κB, but is attenuated for LTR activation. None of the mutants significantly elevated the levels of p21 CIP1 and p27 KIP1 , indicating that the dramatic surge in p21CIP1/WAF1and p27 KIP 1 induced by Tax is brought about by a mechanism distinct from NF-κB or LTR activation. Importantly, the ability of these mutants to activate APC/C is attenuated or abrogated. These data indicate that Tax-induced rapid senescence is causally associated with APC/C activation.
Exercise-training protocols for astronauts in microgravity

The question of the composition of exercise protocols for use by astronauts in microgravity is unresolved. Based on our knowledge of physical working requirements for astronauts during intra- and extravehicular activity and on the findings from bed-rest studies that utilized exercise training as a countermeasure for the reduction of aerobic power, deterioration of muscular strength and endurance, decrements in mood and cognitive performance, and possibly for bone loss, two exercise protocols are proposed. One assumes that, during microgravity, astronaut exercise physiological functions should be maintained at 100% of ground-based levels; the other assumes that maximal aerobic power in flight can be reduced by 10% of the ground-based level. A recommended prescription for in-flight prevention or partial suppression of calcium (bone) loss cannot be written until further research findings are obtained that elucidate the site, the magnitude, and the mechanism of the changes. Hopefully these proposed exercise prescriptions will stimulate further research and discussion resulting in even more efficient protocols that will help ensure the optimal health and well-being of our astronauts.
A Comparison of Calculator Use in Eighth-Grade Mathematics Classrooms in the United States, Japan, and Portugal: Results From the Third International Mathematics and Science Study

The study used data from the Third International Mathematics and Science Study to determine trends in calculator use among Population 2 (13-year-olds) students in Japan, the United States, and Portugal. While relatively high levels of calculator use were observed for the US and Portugal, virtually no calculator use was found for the Japanese sample. Hierarchical Linear Model analysis determined a statistically significant negative relationship between students' frequency of calculator use and student performance in Japan; no statistically significant relationship was detected for the US and Portuguese samples. US student achievement was positively associated with each of the five reported ways in which calculators are used; however, a statistically significant negative relationship was found between student performance and Japanese students' use of calculators on tests. Plausible explanations are explored.
Virus inactivation in blood components by photoactive phenothiazine dyes

The virucidal properties of photoactive phenothiazine dyes, such as methylene blue, have been known approximately 70 years. The mechanism of virus inactivation involves binding of the dye to nucleic acid, absorption of light, generation of reactive oxygen species, guanine oxidation in the viral genome. The first practical research involving phenothiazine photosensitizers in transfusion medicine was sparked by efforts to prevent transmission of hepatitis from pooled plasma administered during the Korean War. During the last decade, methylene blue was used by some European countries for virus photoinactivation in fresh frozen plasma, whereas other phenothiazine derivatives with greater affinities for nucleic acids and capabilities to inactivate intracellular virus have been investigated for photochemical decontamination of red cell suspensions. The toxicity of methylene blue is well characterized; the drug has been used for many years to treat methemoglobinemia using concentrations orders of magnitude greater than those used for virus photoinactivation, and several filters have been developed to remove the dye from plasma. Future widespread use of phenothiazines for virus photoinactivation in blood components may depend on whether the risk inherent in their use is less than the residual risk from transfusion-transmitted viruses.
Differential inhibition of mitochondrial respiratory complexes by inhalation of combustion smoke and carbon monoxide, in vivo, in the rat brain

Combustion smoke contains gases and particulates, which act via hypoxia and cytotoxicity producing mechanisms to injure cells and tissues. While carbon monoxide (CO) is the major toxicant in smoke, its toxicity is exacerbated in the presence of other compounds. Here, we examined modulations of mitochondrial and cytosolic energy metabolism by inhalation of combustion smoke versus CO, in vivo, in the rat brain. Measurements revealed reduced activities of respiratory chain (RC) complexes, with greater inhibition by smoke than equivalent CO in ambient air. In the case of RC complex IV, inhibition by CO and smoke was similar--suggesting that complex IV inhibition is primarily by the action of CO. In contrast, inhibition of complexes I and III was greater by smoke. Increases in cytosolic lactate dehydrogenase and pyruvate kinase activities accompanied inhibition of RC complexes, likely reflecting compensatory increases in cytosolic energy production. Together, the data provide new insights into the mechanisms of smoke inhalation-induced perturbations of brain energetics, which impact neuronal function and contribute to the development of neuropathologies in survivors of exposures to CO and combustion smoke.