cssi/SciSciGPT-SciSciNet huggingface dataset:
Self‐determination through self‐education: culturally responsive schooling for Indigenous students in the USA

In this article, we outline culturally responsive schooling (CRS) for Indigenous youth and situate this concept within a larger history of US federal and community‐based efforts to educate Indigenous youth in the USA. We examine what we know from the research literature about the impacts of CRS among US Indigenous youth. In exploring the research, we rely on national datasets of Indigenous youth's achievement on standardized tests, qualitative approaches to examining CRS in schools serving Indigenous youth in the USA, and case studies of successful efforts at CRS. We pay special, though not exclusive, attention to the evidence regarding Indigenous students' reading and literacy skills since this is an area that is particularly revealing of what happens when CRS is not engaged. We will argue throughout this paper that a growing body of literature points to the fact that community‐ and culture‐based education best meets the educational needs of Indigenous children.
A Time Domain Equivalent Source Model of an Impulse GPR Antenna Based on Measured Radiation Fields

Ground Penetrating Radar (GPR) is a valuable tool for determining bridge deck health. The ability to simulate scattering from bridge deck elements and the complex interactions between them, as well as from changes due to the presence and relative location of defects is important for understanding observed responses. These simulations can be performed using electromagnetic computational modeling techniques such as Finite-Difference Time Domain (FDTD). In order to accurately model the GPR investigation, it is necessary to have a time domain equivalent source model that can launch and receive electromagnetic waves into the computational space that replicates the signals transmitted and received by the physical GPR antenna. However, due to complexity of design and proprietary information, the GPR unit is typically very difficult, or even impossible, to fully model with sufficient detail. For bridge deck applications, simulation in two-dimensions adequately captures much of the three-dimensional scattering. Tw...
Two-dimensional correlation coefficient mapping in gas chromatography: Jet fuel classification for environmental analysis

Abstract We demonstrate the feasibility of using two-dimensional correlation coefficient mapping to classify gas chromatograms of environmental hazards. Correct identification and classification of the contaminants is the prerequisite for their appropriate treatment and containments. A data set consisting of 76 gas chromatograms of eight types of jet fuels, which are common sources of hydrocarbon contamination in ground water, is examined with two-dimensional statistical sample–sample correlation coefficients. Analysis demonstrates that jet fuel samples of the same type correlate strongly with each other but less significantly with other jet fuel classes. According to the magnitude of the correlation coefficients between each pair of the samples, jet fuel types of each sample in the data set can be assigned with an accuracy of 100% through a leave-one-out cross validation (LOOCV) procedure. Correlation coefficient mapping is thus a promising method to classify samples of environmental importance.
Generalized additive models and inflated type I error rates of smoother significance tests

Generalized additive models (GAMs) have distinct advantages over generalized linear models as they allow investigators to make inferences about associations between outcomes and predictors without placing parametric restrictions on the associations. The variable of interest is often smoothed using a locally weighted scatterplot smoothing (LOESS) and the optimal span (degree of smoothing) can be determined by minimizing the Akaike Information Criterion (AIC). A natural hypothesis when using GAMs is to test whether the smoothing term is necessary or if a simpler model would suffice. The statistic of interest is the difference in deviances between models including and excluding the smoothed term. As approximate chi-square tests of this hypothesis are known to be biased, permutation tests are a reasonable alternative. We compare the type I error rates of the chi-square test and of three permutation test methods using synthetic data generated under the null hypothesis. In each permutation method a distribution of differences in deviances is obtained from 999 permuted datasets and the null hypothesis is rejected if the observed statistic falls in the upper 5% of the distribution. One test is a conditional permutation test using the optimal span size for the observed data; this span size is held constant for all permutations. This test is shown to have an inflated type I error rate. Alternatively, the span size can be fixed a priori such that the span selection technique is not reliant on the observed data. This test is shown to be unbiased; however, the choice of span size is not clear. A third method is an unconditional permutation test where the optimal span size is selected for observed and permuted datasets. This test is unbiased though computationally intensive.
Introducing Information Literacy 2.0

In the age of Google, academic library services are changing out of necessity. Students and faculty have many more sources of information beyond the library's offerings and reference desk statistics are plummeting. To remain relevant, academic library services must adapt and librarians must apply their skills in new ways. In this column, the author will explore current issues in academic library services.
An exploratory subgroup analysis of race and gender in squamous cancer of the head and neck: inferior outcomes for African American males in the LORHAN database.

Summary Objectives Previous retrospective analyses show poor outcomes for African American (AA) patients with head and neck carcinoma (HNC). Such racial disparities are not well understood, and generally studies have been too small to investigate subgroups and interactions related to race. Materials and methods The longitudinal oncology registry of head and neck carcinoma registry was used to identify patients ⩾18 years of age with squamous cell carcinoma of the head and neck, with no baseline metastases, and with an adequate record of survival time. Patient demographic and treatment characteristics were evaluated as a function of race and other known potential confounders of outcome. Associations between patient characteristics, including smoking, stage, performance status, and overall survival (OS) and progression-free survival (PFS) outcomes were also examined. Results Analysis of OS and PFS confirmed prior reports of inferior outcomes in AA patients vs. Whites with median OS/3-yr rate 41.7 mo/52% in AAs vs. 56.6 mo/70% in Whites (hazard ratio: 1.69 [95% confidence interval: 1.42, 2.01]). The elevated risk for worse OS and PFS in AAs remained, after multivariate adjustment. African American males incurred most of the excess risk compared to AA females. Conclusion This exploratory study confirmed a worse OS and PFS prognosis for AA patients, and it documents that most of the excess risk occurs in AA males. Future studies should confirm these findings and should investigate biological and other factors that account for such profound differences in outcomes.
Assessing the Great Whirl, despite all the pirates

Each year, the powerful southwest monsoon ramps up in midsummer, bringing life-giving rains to the Indian subcontinent. The monsoon winds also drive dramatic changes in the regional ocean currents, including a reversal in the circulation of the Arabian Sea, an energetic eddy field, and strong coastal upwelling. Off the east coast of Somalia, a large (300- to 550-kilometer wide) anticyclone appears—known since 1876 as the Great Whirl—with surface currents as strong as 2.5 meters per second. The Great Whirl, while associated with the seasonal arrival of the southwest monsoon, is not caused entirely by it; the circulation of the Great Whirl starts a month before and persists for a month after the monsoon.
Spectrum co-existence of IEEE 802.11b and 802.16a networks using reactive and proactive etiquette policies

This paper presents an investigation of spectrum co-existence between IEEE 802.11b and 802.16a networks in the same shared frequency band using cognitive radio techniques with different levels of complexity. Simple reactive interference avoidance algorithms as well as proactive spectrum coordination policies based on etiquette protocols are proposed and compared in terms of achievable spectrum efficiency in a shared Wi-Fi/Wi-Max scenario. In reactive interference avoidance methods, radio nodes coordinate spectrum usage without exchange of explicit control information-this is done by adaptively adjusting transmit PHY parameters such as frequency, power and time occupancy based on local observations of the radio band. Because local observations provide information only about transmitters, they may not be sufficient for resolving spectrum contention in scenarios with "hidden receivers". Proactive coordination techniques solve the hidden-receiver problem by utilizing a common spectrum coordination channel (CSCC) for exchange of transmitter and receiver parameters. Radio nodes can cooperatively select key PHY-layer variables such as frequency and power by broadcasting messages in the CSCC channel and then following specified spectrum etiquette policies. An ns2 simulation model is developed to evaluate both reactive and proactive etiquette policies in scenarios with co-existing IEEE 802.11b and 802.16a networks. The density of radio nodes in the coverage region, and their degree of spatial clustering are key parameters in the system evaluation. Detailed simulation studies were carried out for a variety of scenarios including both single and multiple 802.11b hotspots per 802.16a cell with and without spatial clustering. Our results show that simple reactive algorithms can improve system throughput when sufficient "free space" (in frequency, power or time) is available for PHY adaptation. In more congested scenarios with spatially clustered nodes and hidden receivers, the proposed CSCC etiquette can significantly improve overall system performance over reactive schemes.
Effect of staphylococcal alpha-toxin on neutrophil migration and adhesiveness.

The effect of staphylococcalα-toxin on the chemotactic response of human polymorphonuclear leukocytes was studied by measuring the migration ofα-toxin-treated cells either through membrane filters toward C5a or under agarose towardN-formyl-ι-methionyl-ι-phenylalanine. At doses of ⩾5 hemolytic units,α-toxin depressed chemotactic responsiveness in both best systems. Further studies revealed thatα-toxin was also a potent granulocyte aggregant at doses similar to those necessary for depressed chemotactic capacity. It is proposed that the inhibitory effect of this membrane-active toxin on chemotactic function may be related to increased granulocyte adhesiveness and that the pathogenic properties ofα-toxin may in part by explained by these effects.
Rlip76 transports sunitinib and sorafenib and mediates drug resistance in kidney cancer

RLIP76 is a stress-responsive membrane protein implicated in the regulation of multiple cellular signaling pathways. It represents the predominant glutathione-conjugate (GS-E) transporter in cells. We have shown that RLIP76 plays a crucial role in defending cancer cells from radiation and chemotherapeutic toxin-mediated apoptosis, and that its inhibition by antibodies or depletion by siRNA or antisense causes apoptosis in a number of cancer cell types. We demonstrated for the first time that the striking anti-neoplastic effects with no evident toxicity in terms of either weight loss or metabolic effects are also demonstrable for the antibody, antisense and siRNA in a renal cell xenografts model of Caki-2 cells (Singhal et al., Cancer Res., 2009, 69: 4244). Present studies were performed to determine if RLIP76 targeting is more broadly applicable in other kidney cancer cell lines, to compare the signaling effects of RLIP76 antisense with kinase inhibitors used in treatment of renal cell carcinoma, and to determine whether kinase inhibitors were substrates for transport by RLIP76. Results of these studies show that sorafenib as well as sunitinib are substrates for transport by RLIP76 thus are competitive inhibitors of GS-E transport. Furthermore, kinase inhibition in the ERK as well as PI3K pathways by RLIP76 depletion is more profound and consistent and is more widely apparent in a number of renal carcinoma cell lines. These studies offer strong support for our overall hypothesis that RLIP76 is an overarching anti-apoptosis mechanism that, if inhibited, can be more broadly effective in the treatment of renal cell carcinoma.
Comparisons of measured and calculated potential magnetic fields.

Photospheric line-of-sight and transverse magnetic field data obtained with the Marshall Space Flight Center vector magnetograph system for an isolated sunspot are described. A study of the linear polarization patterns and of the calculated transverse field lines indicates that the magnetic field of the region is very nearly potential. The Hα fibril structures of this region as seen in high resolution photographs corroborate this conclusion. Consequently, a potential field calculation is described using the measured line-of-sight fields together with assumed Neumann boundary conditions; both are necessary and sufficient for a unique solution. The computed transverse fields are then compared with the measured transverse fields to verify the potential field model and assumed boundary values. The implications of these comparisons on the validity of magnetic field extrapolations using potential theory are discussed.
Photon hitting density

Optical and near-IR spectroscopy and imaging of highly scattering tissues require information about the distribution of photon-migration paths. We introduce the concept of the photon hitting density, which describes the expected local time spent by photons traveling between a source and a detector. For systems in which photon transport is diffusive we show that the hitting density can be calculated in terms of diffusion Green’s functions. We report calculations of the hitting density in model systems.
Quantum fluctuations on domain walls, strings, and vacuum bubbles.

We develop a covariant quantum theory of fluctuations on vacuum domain walls and strings. The fluctuations are described by a scalar field defined on the classical world sheet of the defects. We consider the following cases: straight strings and planar walls in flat space, true vacuum bubbles nucleating in false vacuum, and strings and walls nucleating during inflation. The quantum state for the perturbations is constructed so that it respects the original symmetries of the classical solution. In particular, for the case of vacuum bubbles and nucleating strings and walls, the geometry of the world sheet is that of a lower-dimensional de Sitter space, and the problem reduces to the quantization of a scalar field of tachyonic mass in de Sitter space. In all cases, the root-mean-squared fluctuation is evaluated in detail, and the physical implications are briefly discussed.
Diurnal changes in the malic acid content of vacuoles isolated from leaves of the crassulacean acid metabolism plant, Sedum telephium

The accumulation of malic acid at night in green cells followed by malic acid depletion the next day is characteristic of Crassulacean acid metabolism (CAM) plants. The diurnal changes in malic acid content are accompanied by reciprocal changes in starch content with starch providing the carbon skeleton for phosphoenolpyruvate, the CO* acceptor at night. Malic acid is decarboxylated during the day to provide COZ for photosynthesis [ 11. In contrast, other organic acids such as isocitric do not exhibit a daily fluctuation in levels [2]. With the realization that massive amounts of malic acid accumulate at night [ 1,2], it was widely postulated that malic acid is stored in the large vacuoles of green CAM cells. Indeed, calculations based on Bryophyllum leaf cell volumes and the amount of acid accumulated at night showed that ‘if malic acid were confined to the cytoplasm, its concentration would be 7-8 M, but if it were in the vacuole also, its average concentration would be 0.25 M’ [3]. Thus, to prevent a variety of deleterious effects of acidic conditions on cytoplasmic components, a green CAM cell would in theory temporarily sequester malic acid in its vacuole at night. However, data to test this hypothesis are not available. Recently, techniques have been developed for isolating large quantities of vacuoles from plant tissues [4-71. Isolated Bvophyllum leaf vacuoles [6] contained 0.002-0.02 nmol malic acid/vacuole which comprised the bulk of the malic acid present. However
Kinetic chain lengths in highly cross-linked networks formed by the photoinitiated polymerization of divinyl monomers: a gel permeation chromatography investigation.

Highly cross-linked networks formed by the photoinitiated polymerization of multifunctional monomers are finding application in the field of biomaterials because of their chemical versatility, reaction control, and ability to polymerize under physiological conditions. Typically, degradation is introduced into these networks via the cross-links and leads to the release of nondegradable but water-soluble kinetic chains formed during the chain polymerization process. In this study, gel permeation chromatography (GPC) was used to characterize kinetic chain length distributions in highly cross-linked systems that are being developed for orthopedic applications. By polymerizing divinyl monomers to various conversions and subsequently degrading them, we investigated the aspects of network structural evolution related to kinetic chain formation. In general, the average kinetic chain length increased with conversion until the onset of autodeceleration, when the kinetic chains decreased in length as the propagation...
GW182 family proteins are crucial for microRNA-mediated gene silencing.

microRNAs (miRNAs) are a conserved class of small RNAs ∼22 nucleotides in length. They regulate the expression of a large number of mRNAs in animals and plants through the miRNA-induced silencing complex (miRISC). The conserved GW182 family of proteins has recently been identified, and its members have been shown to be associated with miRISC and to be required for miRNA-mediated gene silencing. These proteins have also been localized to processing bodies that are cytoplasmic messenger ribonucleoprotein (mRNP) aggregates containing mRNA decay factors, translational repressors and untranslated mRNAs. Therefore, these properties of GW182 family proteins support the hypothesis that the formation of untranslatable messenger ribonuclear protein particles is one important mechanism of miRNA-mediated gene silencing.
Neurodynamics: nonlinear dynamics and neurobiology.

The use of methods from contemporary nonlinear dynamics in studying neurobiology has been rather limited.Yet, nonlinear dynamics has become a practical tool for analyzing data and verifying models. This has led to productive coupling of nonlinear dynamics with experiments in neurobiology in which the neural circuits are forced with constant stimuli, with slowly varying stimuli, with periodic stimuli, and with more complex information-bearing stimuli. Analysis of these more complex stimuli of neural circuits goes to the heart of how one is to understand the encoding and transmission of information by nervous systems.
Staphylococcus aureus collagen adhesin contributes to the pathogenesis of osteomyelitis

To evaluate the role of the Staphylococcus aureus collagen-binding adhesin (Cna) in bone and joint infection, we generated a cna mutant in S. aureus UAMS-1, a strain that was originally isolated from the bone of a patient suffering from osteomyelitis. The mutant (UAMS-237) was unable to bind collagen but bound fibronectin at levels comparable to UAMS-1. The relative virulence of UAMS-1 and UAMS-237 was assessed using a murine model of acute hematogenous osteomyelitis. Specifically, 10(8) colony-forming units (cfu) were introduced into the bloodstream of NIH-Swiss mice via tail-vein injection. After 2 weeks, the left hind limb was harvested and examined histologically for evidence of osteomyelitis and septic arthritis. Osteomyelitis developed in 14 of 20 mice (70%) infected with UAMS-1, but only 1 of 20 (5%) infected with UAMS-237 (p < 0.001). In contrast, septic arthritis was observed in 12 of 20 mice (60%) infected with UAMS-1 and 14 of 20 (70%) infected with UAMS-237 (p < 0.75). These results indicate that Cna is not required to establish joint infection, but does make an important contribution to the ability of S. aureus to establish infection in bone through hematogenous spread.
In vitro inhibition of monkeypox virus production and spread by Interferon-β.

Background The Orthopoxvirus genus contains numerous virus species that are capable of causing disease in humans, including variola virus (the etiological agent of smallpox), monkeypox virus, cowpox virus, and vaccinia virus (the prototypical member of the genus). Monkeypox is a zoonotic disease that is endemic in the Democratic Republic of the Congo and is characterized by systemic lesion development and prominent lymphadenopathy. Like variola virus, monkeypox virus is a high priority pathogen for therapeutic development due to its potential to cause serious disease with significant health impacts after zoonotic, accidental, or deliberate introduction into a naive population.
Feasibility of a primarily digital research library

This position paper explores the issues related to the feasibility of having a primarily digital research library support the teaching and research needs of a university. The Asian University for Women (AUW), a new university in Chittagong, Bangladesh, will open in September 2009. It must make a decision regarding the investment to be made in research resources to support the university. Mass digitization efforts now make it possible to consider establishing a research library that consists primarily of digital resources rather than print. There are, however, many issues that make this consideration quite complex and far from certain. In this paper we explore the issues at a preliminary level. We focus on four broad perspectives in order to begin addressing the complex interactions that must be considered in transitioning to a primarily digital research environment: technical, economic, policy and social issues. The purpose of this paper is to begin to explore a research agenda for transitioning from a model for libraries where resources are primarily print to one that is predominantly digital. Our research in this area is just beginning, so our purpose is to raise the issues rather than offer firm conclusions.
An Improved Assay for Measuring Heparin Binding to Bull Sperm

Abstract The binding of heparin to sperm has been used to study capacitation and to rank relative fertility of bulls. Previous binding assays were laborious, used 10 7 sperm per assay point, and required large amounts of radiolabeled heparin. A modified heparin-binding assay is described that used only 5×10 4 cells per incubation well and required reduced amounts of [ 3 H] heparin. The assay was performed in 96-well Millititer plates, enabling easy incubation and filtering. Dissociation constants and concentrations of binding sites did not differ if analyzed by Scatchard plots, Woolf plots, or by log-logit transformed weighted nonlinear least squares regression, except in the case of outliers. In such cases, Scatchard analysis was more sensitive to outliers. Nonspecific binding was insignificant using nonlinear logistic fit regression and a proportion graph. The effects were tested of multiple freeze-thawing of sperm in either a commercial egg yolk extender, 40m M Tris buffer with 8% glycerol, or 40m M Tris buffer without glycerol. Freeze-thawing in extender did not affect the dissociation constant or the concentration of binding sites. However, freeze-thawing three times in 40m M Tris reduced the concentration of binding sites and lowered the dissociation constant (raised the affinity). The inclusion of glycerol in the 40m M Tris did not significantly affect the estimated dissociation constant or the concentration of binding sites as compared to 40m M Tris without glycerol.
FRACTIONATION OF TRACE ELEMENTS BY SUBDUCTION-ZONE METAMORPHISM : EFFECT OF CONVERGENT-MARGIN THERMAL EVOLUTION

Differential chemical/isotopic alteration during forearc devolatilization can strongly influence the cycling of volatile components, including some trace elements, in subduction zones. The nature and magnitude of this devolatilization effect are likely to be strongly dependent on the thermal structure of individual convergent margins. A recent model for metamorphism of the Catalina Schist, involving progressive underplating (at ≤45 km depths) of rock packets metamorphosed along successively lower-T prograde P-T paths in a rapidly cooling, newly initiated subduction zone, affords a unique evaluation of the effects of varying prograde P-T paths on the magnitudes of devolatilization and chemical/isotopic alteration of subducting rocks. In the Catalina Schist, the most extensive devolatilization occurred in metasedimentary rocks which experienced prograde P-T paths encountering the epidote-blueschist facies (>350°C at 9 to 12 kbar) or higher-T conditions; such rocks are depleted in ‘fluid-mobile’ elements such as N, B, Cs, As, and Sb relative to protoliths. Removal of these elements resulted in changes in B/(Be, Li, La, Zr), Cs/Th, Rb/Cs, As/Ce, Sb/Ce, and Creduced/N, and increases in δ15N and δ13C. The relative susceptibilities of the “fluid-mobile” elements to loss along increasingly higher-T P-T paths can be categorized. Boron and Cs show the greatest susceptibility to low-T removal by fluids, showing >50% depletion in even lawsonite-blueschist-facies metasedimentary rocks which experienced relatively low-T prograde metamorphic paths. In rocks which experienced higher-T paths, As and Sb (likely in sulfides) show the greatest depletions (>90%); N, Cs, and B (largely in micas) occur at ∼25% of protolith contents in even partially melted amphibolite-facies rocks. Variations in B/Be, Cs/Th, As/Ce, and Sb/Ce among arcs from differing convergent-margin thermal regimes, and conceivably some cross-arc declines in these ratios, are compatible with evidence from the Catalina Schist for varying degrees of element removal as a function of prograde thermal history. In relatively cool subduction zones (e.g., Kuriles, Marianas, Aleutians, southern Alaska) with thermal regimes similar to that which formed the low-grade units of the Catalina Schist (and blueschist-facies rocks in the Franciscan Complex), forearc devolatilization is less profound, B, Cs, As, Sb, and N are more likely to be deeply subducted, and enriched in arc lavas, and significant devolatilization occurs at the blueschist-to-eclogite transition. High-grade units could reflect thermal evolution analogous to that of relatively warm subduction zones (e.g., Cascadia) and back-arcs in which arc lavas are depleted in B, Cs, As, and Sb due to prior removal by forearc devolatilization. The results of this study also imply less efficient recycling of these elements during the warmer Archean subduction which resulted in greater slab melting and production of abundant trondhjemite-tonalite magmatic suites.
Ultrasmall Optical Gyroscopes Based on Microdisk Lasers

We studied numerically the effects of rotation on wavelength-scale microdisk cavities. Rotation-induced changes in quality factor and far-field pattern are much larger than Sagnac frequency splitting, providing multiple methods for rotation sensing with ultrasmall gyroscopes.
Chylopericardium with cardiac tamponade after cardiovascular surgery in two patients.

Two patients developed postoperative chylopericardium leading to acute cardiac tamponade. Delayed diagnosis and urgent thoracotomy did not prevent death in three-month-old patient after the Glenn anastomosis of the superior vena cava to the right pulmonary artery, whereas early recognition of chylopericardium following repair of an interrupted aortic arch in an 11-week-old patient was successfully treated by tube pericardiostomy. The literature is reviewed, and an anatomic predisposition for postsurgical chylopericardium is proposed.
Neuron mid-infrared absorption study for direct optical excitation of neurons

Neuron optical excitations are important for brain-circuitry explorations and sensory-neuron-stimulation applications. To optimize the stimulation, we identify neuron mid-IR absorption peaks in this study and discuss their meanings and delivery methods of mid-IR photons.
Developmental potency of the murine allantois

The murine allantois is the future umbilical component of the placenta. The base of the allantois is also thought to contain the future germ line. We have examined the fate and developmental potency of cells within the murine allantois during gastrulation. lacZ-expressing headfold-stage allantoises (approximately 8.0 days postcoitum; dpc) were subdivided into three proximodistal regions and transplanted into three sites in synchronous non-transgenic host embryos: the primitive streak at the level of prospective paraxial mesoderm, the primitive streak at the level of lateral plate mesoderm, and the base of the allantois. After 23 hours in culture, operated conceptuses were examined histologically for contribution of donor allantoic cells to the conceptus. None of the allantoic regions contributed to paraxial mesoderm when placed into the fetus, but all three colonized the endothelium and adjacent mesenchyme of the dorsal aorta. The mid-region was most efficient at colonizing endothelium, whereas the base was the only allantoic region to exhibit relative pluripotency, colonizing several derivatives of all three primary germ layers. Differences in the state of differentiation along the proximodistal axis of the allantois were further borne out when the three allantoic regions were placed into the base of the allantois of host conceptuses. Striking differences were observed in final position along the proximodistal axis of the host allantois. Most grafted cells translocated distally from the base; however, basal donor allantoic cells translocated typically only as far as the host's mid-region, whereas donor allantoic tip cells typically returned to the tip, often colonizing the chorioallantoic fusion junction. Together, our data reveal that the headfold-stage allantois may contain a proximodistal gradient of differentiation, and raise intriguing questions about how this gradient was established and the role it plays in umbilical vasculogenesis.
Selection for late pupariation affects diapause incidence and duration in the flesh fly, Sarcophaga bullata

This artificial selection study with the flesh fly, Sarcophaga bullata Parker, tested the hypothesis that phenotypic variability in the length of the larval stage (under non-diapause conditions) is largely a consequence of genetic variability. Selection for late pupariation resulted in a line that pupariated significantly later and also developed more slowly during other stages of the life cycle. In a diapause-inducing environment, the selected line pupariated later, showed a higher incidence of pupal diapause, and remained in diapause longer than the unselected line. This is the first experimental evidence in S.bullata to show that diapause incidence and duration are related. The relationship between developmental rate and diapause traits may stem from the pleiotropic effects of genes associated with late pupariation, or from one or more genes associated with late pupariation being closely linked to genes that affect diapause.
Challenges of marijuana research.

The use of any drug ideally represents a decision based on objective, scientifically based cost–benefit analyses that factor in both the short and long-term effects of that exposure. Pharmacological, toxicological, pharmacokinetic and pharmacodynamic investigations that are deemed to be essential for the rational use of any therapeutic agent are therefore part of the usual drug approval process. With regard to marijuana, sociopolitical factors have intervened in this scientific process. Three major lay perspectives appear to dominate the societal view of marijuana—the ‘reefer madness’ camp holding the view that there are no redeeming attributes to the ‘evil weed’, the ‘innocuous’ camp who consider it to be a harmless recreational substance and the ‘medical marijuana’ camp that believes marijuana to be a panacea for a multitude of aches, pains and chronic diseases with, of course, every shade of opinion in-between. On the scientific front, three trends preface nearly every recent journal article concerning marijuana—the significant prevalence of marijuana use, the changes in age of first use (Kohn et al ., 2005; Monshouwer et al ., 2005) and the increasing strength of the drug, leading to higher acute and chronic exposures (National Institute on Drug Abuse, 2005; Pijlman et al ., 2005). For example, in 2004 ∼96.8 (40.2%), 25.5 (10.6%) and 14.6 (6.1%) million Americans aged 12 and older were considered to have used marijuana within their lifetime, the last year, and the last month, respectively (Office of National Drug Control Policy, 2006). However, in the 3 of the 11 states in which medical use of marijuana is legal, and for which statistics are available, 0.05% of the population are registered, i.e. legal, users (General Accounting Office, 2002). Even though marijuana is available from pharmacies in the Netherlands, 80% of users secure their drug via illicit channels (Erkens et al ., …
Validation of Lucigenin (Bis-N-methylacridinium) as a Chemilumigenic Probe for Detecting Superoxide Anion Radical Production by Enzymatic and Cellular Systems*

Lucigenin is most noted for its wide use as a chemiluminescent detector of superoxide anion radical (O2-.) production by biological systems. However, its validity as a O2-.-detecting probe has recently been questioned in view of its ability to undergo redox cycling in several in vitro enzymatic systems, which produce little or no O2-.. Whether and to what extent lucigenin redox cycling occurs in systems that produce significant amounts of O2-. has not been carefully investigated. We examined and correlated three end points, including sensitive measurement of lucigenin-derived chemiluminescence (LDCL), O2 consumption by oxygen polarography, and O2-. production by 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide spin trapping to characterize the potential of lucigenin to undergo redox cycling and as such to act as an additional source of O2-. in various enzymatic and cellular systems. Marked LDCL was elicited at lucigenin concentrations ranging from 1 to 5 microM in all of the O2-.-generating systems examined, including xanthine oxidase (XO)/xanthine, lipoamide dehydrogenase/ NADH, isolated mitochondria, mitochondria in intact cells, and phagocytic NADPH oxidase. These concentrations of lucigenin were far below those that stimulated additional O2 consumption or O2-. production in the above systems. Moreover, a significant linear correlation between LDCL and superoxide dismutase-inhibitable cytochrome c reduction was observed in the XO/ xanthine and phagocytic NADPH oxidase systems. In contrast to the above O2-.-generating systems, no LDCL was observed at non-redox cycling concentrations of lucigenin in the glucose oxidase/glucose and XO/NADH systems, which do not produce a significant amount of O2-.. Thus, LDCL still appears to be a valid probe for detecting O2-. production by enzymatic and cellular sources.
Goal Representations and Motivational Drive in Schizophrenia: The Role of Prefrontal–Striatal Interactions

The past several years have seen a resurgence of interest in understanding the psychological and neural bases of what are often referred to as “negative symptoms” in schizophrenia. These aspects of schizophrenia include constructs such as asociality, avolition (a reduction in the motivation to initiate or persist in goal-directed behavior), and anhedonia (a reduction in the ability to experience pleasure). We believe that these dimensions of impairment in individuals with schizophrenia reflect difficulties using internal representations of emotional experiences, previous rewards, and motivational goals to drive current and future behavior in a way that would allow them to obtain desired outcomes, a deficit that has major clinical significance in terms of functional capacity. In this article, we review the major components of the systems that link experienced and anticipated rewards with motivated behavior that could potentially be impaired in schizophrenia. We conclude that the existing evidence suggests relatively intact hedonics in schizophrenia, but impairments in some aspects of reinforcement learning, reward prediction, and prediction error processing, consistent with an impairment in “wanting.” As of yet, there is only indirect evidence of impairment in anterior cingulate and orbital frontal function that may support value and effort computations. However, there are intriguing hints that individuals with schizophrenia may not be able to use reward information to modulate cognitive control and dorsolateral prefrontal cortex function, suggesting a potentially important role for cortical–striatal interactions in mediating impairment in motivated and goal-directed behavior in schizophrenia.
Photochemical Ring Contraction of 2‐Ethoxypyrrolin‐5‐ones to Cyclopropanone Derivatives: tert‐Butyl N‐(1‐Ethoxycyclopropyl)carbamate

Photochemical ring contraction of 2-ethoxypyrrolin-5-ones to cyclopropanone derivatives: tert-butyl N-(1-ethoxycyclopropyl)carbamate intermediate: silver salt of succinimide intermediate: 6.26 g. (0.0493 mole) of redistilled 2-ethoxypyrrolin-5-one product: tert-butyl N-(1-ethoxycyclopropyl)carbamate Keywords: alkylation, O-alkylation; carbonylation; metalation reactions, silver; photochemical reactions; rearrangements; tert-butyl alcohol; chloroform; sodium ethoxide solution, preparation; succinimide silver salt; chlorosulfonyl isocyanate, violent reaction with water; photochemical apparatus; photochemical apparatus, immersion well, quartz, waterjacketed
Do Women Have Worse Outcome After Stroke Caused by Intracranial Arterial Stenosis

See related article, pages 2055–2062. Stroke affects both women and men, but it is the leading cause of mortality in women.1 Although many aspects of the disease are similar in women and men, there is a growing body of evidence to support sex (a biologic status determined by sex chromosomes and sex hormones) and gender (sex determined by social, cultural, and educational context) differences in the epidemiology of stroke. Numerous reports have demonstrated sex-specific differences in the prevalence, clinical presentation, management, recanalization rate of intracranial artery stenosis after intravenous or intra-arterial thrombolysis in acute ischemic stroke, and clinical outcomes of stroke of all subtypes.2–6 The results are, however, often conflicting and there is a paucity of randomized controlled trial support regarding sex-related stroke care delivery. The recent gender-specific analysis from the Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) study7 provided very important evidence that women with symptomatic intracranial arterial stenosis have considerable increased risk for stroke and vascular death than men. These data contrast a common perception that men have greater risk of recurrent stroke then women. The WASID study had a good representation of women (38%), similar to the NINDS Stroke TPA study (42%),8 and the recent SPARCL study (40%),9 but in comparison to these studies showed a considerate gender-specific difference in stroke outcome. Women in the WASID study had more comorbidities (except coronary artery disease), higher body mass index and total cholesterol, were more sedentary but consumed less alcohol and cigarettes, had positive family history of stroke, and had different sociodemographic characteristics. In addition, women were more likely to have intracranial stenosis of the middle cerebral artery, but the proportion of severe intracranial artery stenosis was not different in men. Women had a considerable greater risk of …
A scale study of electro‐rheological fluid dampers

The goal of this study is to develop a scale analysis for predicting the behavior of cylindrical electro-rheological fluid (ERF) dampers. Theoretical and experimental scale studies are conducted to investigate the effects of the length of dampers and applied electric field strength on the damping and stiffness coefficients of ERF shock absorbers. It is demonstrated that by employing the results obtained from smaller size prototypes, the damping coefficient of larger size dampers can be estimated with reasonable accuracy.
The past as Prelude to the Future: History, Status, and Future of Antiviral Drugs

OBJECTIVE:To review the first generation of antiviral agents (e.g., idoxuridine, amantadine, vidarabine) that paralleled discovery of antineoplastic agents.DATA SOURCES:A MEDLINE search (1962 to 1996) of the English-language literature pertaining to antiviral agents was performed.DATA EXTRACTION:All articles were considered for this review. Pertinent references on antiviral therapy, as judged by the author, were selected.DATA SYNTHESIS:Acyclovir, the first second-generation antiviral agent, has a known selective mechanism of action and provides the model for development of future antiviral therapies. Despite the safety and clinical value of acyclovir, therapy does not prevent establishment of latency or decrease frequency of occurrences, resistance has been documented, and outcome is frequently poor. With the emergence of the HIV/AIDS epidemic, several antiretroviral agents have been developed and approved. However, none of the four available nucleoside analogs provides a cure.CONCLUSIONS:Viral resistance...
Can delivery room management impact the length of hospital stay in premature infants

To evaluate the impact of initiating early nasal continuous positive airway pressure (ENCPAP) on the length of hospital stay (LOS) for the very low birth weight (VLBW) infants. LOS at the George Washington University Hospital (GW) after the institution of ENCPAP policy was compared to benchmark values using two-tail t-tests. The incidence of neonatal morbidity was calculated using Bonferroni corrected 95% confidence interval as compared to benchmark rates (α=0.001). Comparisons were repeated after stratification of the population into four birth weight subcategories: group A (GrpA) (501 to 750 g), GrpB (751 to 1000 g), GrpC (1001 to 1250 g) and GrpD (1251 to 1500 g). We studied 228 consecutive VLBW infants (birth weight: 995±294 g and gestational age: 27.7±2.7 weeks). Compared to benchmark values, the GW experience was associated with a significant reduction of 5.1 days in LOS (55.9±25.2 vs 61±32 days; P=0.04). The decrease in LOS was consistent in all subgroups, but was most noticeable in infants of the smallest weight subcategory (LOS in GrpA=86±21 vs 104±32, P=0.004; in GrpB=69.9±16.7 vs 79±27, P=0.018; in GrpC=48.2±13 vs 56±22, P<0.001 and in GrpD=31.7±12.5 vs 40±19, P=0.003). In the overall population, a lower incidence of chronic lung disease (CLD) (17.8 vs 29%, P<0.001) was also noted. There were no differences in mortality rates (9 vs 14%), or the incidence of necrotizing enterocolitis (NEC) (8 vs 6%) or intraventricular hemorrhage (6.2 vs 9%) between GW and the established benchmark rates. ENCPAP may reduce LOS in VLBW infants in our study population. This relatively shorter LOS was associated with a lower incidence of CLD, which may be a contributing factor.
Three-Dimensional Volume Reconstruction Based on Trajectory Fusion from Confocal Laser Scanning Microscope Images

In this paper, we address the problem of 3D volume reconstruction from depth adjacent subvolumes (i.e., sets of image frames) acquired using a confocal laser scanning microscope (CLSM). Our goal is to align sub-volumes by estimating an optimal global image transformation which preserves morphological smoothness of medical structures (called features, e.g., blood vessels) inside of a reconstructed 3D volume. We approached the problem by learning morphological characteristics of structures inside of each sub-volume, i.e. centroid trajectories of features. Next, adjacent sub-volumes are aligned by fusing the morphological characteristics of structures using extrapolation or model fitting. Finally, a global sub-volume to subvolume transformation is computed based on the entire set of fused structures. The trajectory-based 3D volume reconstruction method described here is evaluated with a pair of consecutive physical sections using two evaluation metrics for morphological continu
Passive Synthetic Aperture Hitchhiker Imaging of Ground Moving Targets - Part 2: Performance Analysis

In Part 1 of this work, we present a passive synthetic aperture imaging and velocity estimation method for ground moving targets using a network of passive receivers. The method involves inversion of a Radon transform type forward model via a novel filtered backprojection approach combined with entropy optimization. The method is applicable to noncooperative transmitters of opportunity where the transmitter locations and transmitted waveforms are unknown. Furthermore, it can image multiple targets moving at different velocities in arbitrary imaging geometries. In this paper, we present a detailed analysis of the performance of our method. First the resolution analysis in position and velocity spaces is presented. The analysis identifies several factors that contribute positively or negativity towards position and velocity resolution. Next, we present a novel theory to analyze and predict smearing artifacts in position images due to error in velocity estimation of moving targets. Specifically, we show that small errors in the velocity estimation result in small positioning errors. We present extensive numerical simulations to demonstrate the theoretical results. While our primary interest lies in radar, the theory, methods and algorithms introduced in our work are also applicable to passive acoustic, seismic, and microwave imaging.
Utilization of a radioiodinated bile salt for kinetic studies and hepatic scintigraphy: Studies in nonhuman mammals

An 125I- or 131I-labeled bile salt derivative, cholylglycyliodohistamine, has been synthesized and purified. The bile salt derivative is rapidly cleared from the circulation when injected intravenously into rats and rabbits. Ten minutes after injection, approximately 50% of the recovered bile salt derivative was in the jejunum and ileum, and 36% was found in the liver. Sixty minutes after injection, 99% of the recovered radioactivity was found in the luminal gastrointestinal tract. The isotope was cleared from the circulation of rabbits with a t1/2 of approximately 2 min. Hepatic scintigraphy using rabbits demonstrated rapid uptake by the liver and excretion into the intestine. Quantitative analysis of scintigraphy showed an uptake rate of 14%/min and a subsequent excretory rate of 4.6/min.
Complexity and coherency: integrating information in the brain

The brains of higher mammals are extraordinary integrative devices. Signals from large numbers of functionally specialized groups of neurons distributed over many brain regions are integrated to generate a coherent, multimodal scene. Signals from the environment are integrated with ongoing, patterned neural activity that provides them with a meaningful context. We review recent advances in neurophysiology and neuroimaging that are beginning to reveal the neural mechanisms of integration. In addition, we discuss concepts and measures derived from information theory that lend a theoretical basis to the notion of complexity as integration of information and suggest new experimental tests of these concepts.