cssi/SciSciGPT-SciSciNet huggingface dataset:
Characterization of the Outer Membrane Receptor ShuA from the Heme Uptake System of Shigella dysenteriae SUBSTRATE SPECIFICITY AND IDENTIFICATION OF THE HEME PROTEIN LIGANDS

Shigella dysenteriae, like many bacterial pathogens, has evolved outer membrane receptor-mediated pathways for the uptake and utilization of heme as an iron source. As a first step toward understanding the mechanism of heme uptake we have undertaken a site-directed mutagenesis, spectroscopic, and kinetic analysis of the outer membrane receptor ShuA of S. dysenteriae. Purification of the outer membrane receptor gave a single band of molecular mass 73 kDa on SDS-PAGE. Initial spectroscopic analysis of the protein in either detergent micelles or lipid bicelles revealed residual heme bound to the receptor, with a Soret maximum at 413 nm. Titration of the protein with exogenous heme gave a Soret peak at 437 nm in detergent micelles, and 402 nm in lipid bicelles. However, transfer of heme from hemoglobin yields a Soret maximum at 413 nm identical to that of the isolated protein. Further spectroscopic and kinetic analysis revealed that hemoglobin in the oxidized state is the most likely physiological substrate for ShuA. In addition, mutation of the conserved histidines, H86A or H420A, resulted in a loss of the ability of the receptor to efficiently extract heme from hemoglobin. In contrast the double mutant H86A/H420A was unable to extract heme from hemoglobin. These findings taken together confirm that both His-86 and His-420 are essential for substrate recognition, heme coordination, and transfer. Furthermore, the full-length TonB was shown to form a 1:1 complex with either apo-ShuA H86A/H420A or the wild-type ShuA. These observations provide a basis for future studies on the coordination and transport of heme by the TonB-dependent outer membrane receptors.
j Dependence of the ( F 19 , O 16 ) Reaction and Spin-Orbit Forces in the Heavy-Ion Optical Potential

The shapes of the observed angular distributions for the reactions $^{28,30}\mathrm{Si}$($^{19}\mathrm{F}$, $^{16}\mathrm{O}$)$^{31,33}\mathrm{P}$ to ${\frac{3}{2}}^{+}$ and ${\frac{5}{2}}^{+}$ states differ strongly. A consistent description of this $j$ dependence and of the ground-state ${\mathrm{\textonehalf{}}}^{+}$ angular distributions is given by distorted-wave Born-approximation calculations which assume triton cluster transfer and include spin-orbit potentials in both entrance and exit channels. We find from coupled-channel Born-approximation calculations that inelastic excitation of $^{19}\mathrm{F}$ does not affect the shapes significantly.
Xylem conductivity and vulnerability to cavitation of ponderosa pine growing in contrasting climates

We examined the effects of increased transpiration demand on xylem hydraulic conductivity and vulnerability to cavitation of mature ponderosa pine (Pinus ponderosa Laws.) by comparing trees growing in contrasting climates. Previous studies determined that trees growing in warm and dry sites (desert) had half the leaf/sapwood area ratio (A(L)/A(S)) and more than twice the transpiration rate of trees growing in cool and moist sites (montane). We predicted that high transpiration rates would be associated with increased specific hydraulic conductivity (K(S)) and increased resistance to xylem cavitation. Desert trees had 19% higher K(S) than montane trees, primarily because of larger tracheid lumen diameters. Predawn water potential and water potential differences between the soil and the shoot were similar for desert and montane trees, suggesting that differences in tracheid anatomy, and therefore K(S), were caused primarily by temperature and evaporative demand, rather than soil drought. Vulnerability to xylem cavitation did not differ between desert and montane populations. A 50% loss in hydraulic conductivity occurred at water potentials between -2.61 and -2.65 MPa, and vulnerability to xylem cavitation did not vary with stem size. Minimum xylem tensions of desert and montane trees did not drop below -2.05 MPa. Foliage turgor loss point did not differ between climate groups and corresponded to mean minimum xylem tensions in the field. In addition to low A(L)/A(S), high K(S) in desert trees may provide a way to increase tree hydraulic conductivity in response to high evaporative demand and prevent xylem tensions from reaching values that cause catastrophic cavitation. In ponderosa pine, the flexible responses of A(L)/A(S) and K(S) to climate may preclude the existence of significant intraspecific variation in the vulnerability of xylem to cavitation.
Studies on the disposition of quinolinic acid after intracerebral or systemic administration in the rat

Quinolinic acid (QUIN) is an endogenous, excitotoxic amino acid which is currently under investigation as a possible etiological factor in human neurodegenerative disorders such as Huntington's disease and epilepsy. We explored certain aspects of this hypothesis, using the adult rat as an experimental animal. After intrastriatal infusions of [3H]QUIN, radioactivity was cleared from the injected region with an apparent half-life of 22 min. To 2 h after injection, all radioactivity recovered from the striatum corresponded to unmetabolized QUIN. Consistent with these data was the lack of significant uptake of [3H]QUIN by slices or crude synaptosomes prepared from rat hippocampus or striatum. When applied intravenously, a high dose of QUIN (450 mg/kg) caused relatively minor seizure-related EEG changes and no signs of neuronal degeneration. Direct measurements indicated negligible penetration of the blood-brain barrier by QUIN. The lack of an effective inactivation mechanism for extracellular QUIN in the brain negates QUIN's proposed role as a classical neurotransmitter substance, but may be of significance for the postulated effects of this compound in neurodegenerative diseases. An important role of blood-borne QUIN or QUIN precursors in human disorders cannot be ruled out at present; although the brain appears to be well protected by the blood-brain barrier from an acute elevation of blood QUIN, a possible breakdown of the barrier under pathologic conditions and the effects of chronic elevations of blood QUIN remain to be examined.
Patterns and Predictors of Formal and Informal Care Among Elderly Persons Living in Board and Care Homes

The purpose of this study was to investigate the patterns and predictors of formal and informal help among a sample of older persons living in board and care homes (N = 617). Formal helpers such as facility staff, service agencies, and community organizations were the most common providers of assistance, particularly for activities of daily living (ADLs; e.g., bathing, dressing, toileting) that required close and continual proximity. Informal helpers such as family members, friends, and other residents were most likely to assist with instrumental ADL (IADL) tasks such as shopping and getting around outside. The need for assistance with ADLs predicted the amount of formal ADL help received by residents, whereas both ADL need and the presence of mental illness predicted the amount of IADL help received from formal sources. In contrast, demographic factors such as gender and race, as well as the frequency of family contact, predicted the amount of informal help with IADL tasks. White residents, women, and those with frequent family contact were among those most likely to receive assistance from informal helpers. The results suggest the need to encourage the provision of informal assistance as well as the need to ensure the availability of sufficient staff and other formal helpers are available to provide formal care in these settings.
Chlorotrifluoroethylene oligomer based nonflammable hydraulic fluid. 2 Hydraulic components' development

A requirement for a nonflammable hydraulic fluid was defined in the 1970s to eliminate losses attributable to hydraulic system fires. In order to increase the possibility of success of the nonflammable hydraulic fluid development programme, requirements for compatibility with current hydraulic fluids, seals, and system designs were not established. All previous attempts to develop a compatible nonflammable hydraulic fluid had been unsuccessful. Extensive screening of many chemical classes of candidate base fluids led to the selection of a Chlorotrifluoroethylene (CTFE) oligomer. Considerable hardwarel system development was performed for hydraulic system applications, including development of high-pressure actuators, pumps, and motors. The major thrust of the programme, a totally new system design, was demonstrated in the Lockheed High Technology Test Bed air craft and in the McDonnell Douglas Aircraft 55.2 MPa (8000 psi) technology ‘Iron Bird’ demonstrator. Possible retrofit applications for current systems include a C135E fireproof brake system and the M1/M1A1 Abrams tank gun mount. This paper also discusses material compatibility requirements, design considerations, and the results of pump testing of the nonflammable hydraulic fluid.
Energetic and entropic contributions to mobility selectivity in glassy polymers for gas separation membranes

Gas transport and separation properties of a series of glassy polymers from different families are studied, and energetic and entropic contributions to diffusivity selectivity are estimated for the oxygen/nitrogen gas pair. Some polymers are found to entropically favor the diffusion of nitrogen over oxygen, despite an overall diffusivity selectivity favoring oxygen. General structural features of glassy polymeric matrices are identified which may be responsible for the magnitude of energetic and entropic contributions to diffusivity selectivity. Overly well-packed structures only result in entropic and energetic factors working to oppose each other leading to average overall diffusivity selectivities and low absolute diffusivities and permeabilities. On the other hand, rigidity of the polymer backbone introduced by substituent groups, hindering chain motion and disrupting packing, often leads to lower energetic contributions and similar entropic effects for both gas molecules. Increasing the entropic cont...
Optimization of the alexandrite laser tuning elements for a water vapor lidar

An overview of some of the developments completed on an alexandrite laser for making water vapor DIAL measurements is presented in this paper. A computer control for active stabilization of the two intracavity etalons has been implemented and recently tested in an aircraft environment. Long-term frequency drift (i.e., 2 hours) of less than 0.7 pm has been observed in the laboratory. An alignment technique to get the optimum free spectral range ratio for the two etalons is also developed.
Model for simulating soil-water content considering evapotranspiration — Reply

Abstract A mathematical model is developed to predict the soil-water content profile under transient field conditions. It takes into account a variable transpiration rate and a nonuniform initial soil-water content. Rainfall, irrigation, and evaporation are treated as sources of nonuniform potential surface flux. The possibility of no flux at the soil surface is also included in the model. Solutions to the model are obtained numerically by a finite-difference scheme involving predictor-corrector equations. The scheme results in a tridiagonal set of simultaneous equations which can be solved rapidly in a digital computer. A step-by-step description of the computational procedure is included. Application of the model to some field conditions and comparison of the results with field-measured data shows very good agreement. Sensitivity of the model to changes in rooting zone, root density function, and depth to the bottom boundary is also analyzed.
Using the Violence Prevention Community Meeting Protocol

Assaultive behavior is a serious problem in health care. Nurses, nursing assistants, and other patients increasingly are becoming targets for patient assault. Costs of assaults are high, both in terms of dollars spent and clinical repercussions such as staff injury and lowered morale. This article describes the development of a protocol, in the form of clinical practice guidelines, for a community meeting to decrease assaultive behavior. Implications include use of the guidelines and the need to conduct either a before-and-after study or a comparison of one unit using the intervention with one not using it. There are also questions identified for further study that would test the broad effectiveness of the Violence Prevention Community Meeting guidelines.
Bias properties of Bayesian statistics in finite mixture of negative binomial regression models in crash data analysis

Factors that cause heterogeneity in crash data are often unknown to researchers and failure to accommodate such heterogeneity in statistical models can undermine the validity of empirical results. A recently proposed finite mixture for the negative binomial regression model has shown a potential advantage in addressing the unobserved heterogeneity as well as providing useful information about features of the population under study. Despite its usefulness, however, no study has been found to examine the performance of this finite mixture under various conditions of sample sizes and sample-mean values that are common in crash data analysis. This study investigated the bias associated with the Bayesian summary statistics (posterior mean and median) of dispersion parameters in the two-component finite mixture of negative binomial regression models. A simulation study was conducted using various sample sizes under different sample-mean values. Two prior specifications (non-informative and weakly-informative) on the dispersion parameter were also compared. The results showed that the posterior mean using the non-informative prior exhibited a high bias for the dispersion parameter and should be avoided when the dataset contains less than 2,000 observations (even for high sample-mean values). The posterior median showed much better bias properties, particularly at small sample sizes and small sample means. However, as the sample size increases, the posterior median using the non-informative prior also began to exhibit an upward-bias trend. In such cases, the posterior mean or median with the weakly-informative prior provided smaller bias. Based on simulation results, guidelines about the choice of priors and the summary statistics to use are presented for different sample sizes and sample-mean values.
Genome-wide analysis of Foxp3 target genes in developing and mature regulatory T cells

Transcription factor Foxp3 (forkhead box P3), restricted in its expression to a specialized regulatory CD4+ T-cell subset (T(R)) with a dedicated suppressor function, controls T(R) lineage development. In humans and mice, Foxp3 deficiency results in a paucity of T(R) cells and a fatal breach in immunological tolerance, causing highly aggressive multi-organ autoimmune pathology. Here, through genome-wide analysis combining chromatin immunoprecipitation with mouse genome tiling array profiling, we identify Foxp3 binding regions for approximately 700 genes and for an intergenically encoded microRNA. We find that a large number of Foxp3-bound genes are up- or downregulated in Foxp3+ T cells, suggesting that Foxp3 acts as both a transcriptional activator and repressor. Foxp3-mediated regulation unique to the thymus affects, among others, genes encoding nuclear factors that control gene expression and chromatin remodelling. In contrast, Foxp3 target genes shared by the thymic and peripheral T(R) cells encode primarily plasma membrane proteins, as well as cell signalling proteins. Together, our studies suggest that distinct transcriptional sub-programmes implemented by Foxp3 establish T(R) lineage during differentiation and its proliferative and functional competence in the periphery.
Exponential growth of Betti numbers

Abstract We prove over some local commutative noetherian rings that the sequence of Betti numbers of every finitely generated module is either eventually constant or has termwise exponential growth.
Response of channel catfish to multi-factor and divergent selection of economic traits

Abstract Three experiments were conducted to evaluate responses of channel catfish ( Ictalurus punctatus ) to divergent selection for commercially important traits. Experiment 1 included lines selected upward (WT+) and downward ((WT−) for 40-week body weight. Catfish in Experiment 2 were selected in two opposite directions (CV+ and CV− lines) for body weight heterogeneity determined by coefficient of variation. Experiment 3 included catfish selected simultaneously in opposite directions (PR+ and PR− lines) for four traits. All three experiments included a control line propagated by random breeding each generation. Results of two generations of selection for Experiments 1 and 2 and three generations for Experiment 3 indicated that: (1) responses to divergent selection for body weight were asymmetrical and varied between generations; (2) genetic and environmental differences among lines replicated in different years strongly influenced selection response for body weight; (3) WT+ and WT− lines diverged in body weight after one generation of selection and remained significantly different in the second generation; (4) channel catfish did not respond to two generations of selection for body weight heterogeneity; (5) after three generations of selection, PR+ catfish were heavier, longer, and more efficient in feed conversion than the control fish; and (6) correlated responses for total length generally agreed with observations made on direct responses for body weight.
Hormonal regulation of proliferation in two populations of rabbit endometrial cells in culture.

Abstract We have previously described a technique to culture rabbit primary endometrium epithelial cells in chemically defined medium, whose proliferation was determined to respond to estrogens and progesterone. The cultures were found to be made up of two cell populations: quiescent and dividing cells. We describe here techniques to select for these two cell populations using 3 H-thymidine and cytosine arabinoside or Colcemid. The quiescent cells were found to be the only target for the growth-promoting effect of estrogens. Epidermal growth factor and prostaglandin F-2α stimulated the proliferation of both cell populations. Progesterone was found not to antagonize the effect of estrogen on the quiescent cells unless the hormone was incubated previously with a mixed cell culture. This finding suggests the existence of a progesterone putative factor (PPF) resulting from the interaction of progesterone and dividing cells which is involved in the inhibition of the estrogenic effect on endometrial cell proliferation. Two other progestins were not found to have the same effect as progesterone, showing the specificity of this ovarian hormone action.
Acute effects of all-trans-retinoic acid in ischemic injury

All-trans-retinoic acid (ATRA) is a vitamin A derivative that is important in neuronal patterning, survival, and neurite outgrowth. Neuroprotective effects of ATRA in ischemia have been demonstrated but its effects on glial swelling are not known. We investigated the relatively acute effects of ATRA on cell swelling in ischemic injury and on key features hypothesized to contribute to cell swelling including increased reactive oxygen species/reactive nitrogen species (ROS/RNS), depolarization of the inner mitochondrial membrane potential (ΔΨm), and increased intracellular calcium ([Ca2+]i). C6 glial cultures were subjected to 5 hr oxygen-glucose deprivation (OGD). ATRA was added to separate groups after the end of OGD. OGD increased cell volume by 43%, determined at 90 min after the end of OGD, but this increase was significantly attenuated by ATRA. OGD induced an increase in ROS/RNS production in the whole cell and mitochondria, as assessed by the fluorescent dyes CM-H2DCFDA and MitoTracker CM-H2-XROS at the end of OGD. The increase in mitochondrial ROS, but not cellular ROS, was significantly attenuated by ATRA. OGD also induced a 67% decline in mitochondrial ΔΨm but this decline was significantly attenuated by ATRA. OGD-induced increase in [Ca2+]i was also significantly attenuated by ATRA. Taken together with our previous results where calcium channel blockers reduced cell swelling, the effects of ATRA in attenuating swelling are possibly mediated through its effects in regulating [Ca2+]i. Considering the paucity of agents in attenuating brain edema in ischemia, ATRA has the potential to reduce brain edema and associated neural damage in ischemic injury.
Distinction, integration and identity: Motivations for local language literacy in Senegalese communities

Abstract Successful adult literacy and basic education programs are notoriously difficult to achieve. One reason for this has to do with how the question, “literacy for what?” is answered for a given program. All too frequently, the answer to that question is shaped more by the goals of the literacy provider than it is by learners’ own goals and desires. Accurate assessment of people's motivations for participating in literacy programs can uncover motivations beyond the economic or development-related outcomes so often given as reasons for becoming literate. One type of motivation which has received limited attention is that related to cultural identity and cultural expression. Such motivations do not figure strongly for many of the target populations of literacy programs; yet for the minority language speakers of sub-Saharan Africa and elsewhere, the issues of cultural and linguistic identity are significant and could easily give rise to this type of motivation. This paper addresses the question of whether cultural identity and expression, linked to the development and use of the mother tongue, are really a reliable motivation for adult literacy. Based on research done in five language communities of Senegal, the paper argues that two strong motivations exist among these communities for literacy: (1) the drive for internal social cohesion, solidarity and cultural uniqueness and (2) the drive towards citizenship, acceptance and equality in the larger national society. These two motivations, while apparently in opposition to each other, actually complement and enhance each other in the literacy programs under study.
Campus Grids Meet Applications: Modeling, Metascheduling and Integration

Air Quality Forecasting (AQF) is a new discipline that attempts to reliably predict atmospheric pollution. An AQF application has complex workflows and in order to produce timely and reliable forecast results, each execution requires access to diverse and distributed computational and storage resources. Deploying AQF on Grids is one option to satisfy such needs, but requires the related Grid middleware to support automated workflow scheduling and execution on Grid resources. In this paper, we analyze the challenges in deploying an AQF application in a campus Grid environment and present our current efforts to develop a general solution for Grid-enabling scientific workflow applications in the GRACCE project. In GRACCE, an application’s workflow is described using GAMDL, a powerful dataflow language for describing application logic. The GRACCE metascheduling architecture provides the functionalities required for co-allocating Grid resources for workflow tasks, scheduling the workflows and monitoring their execution. By providing an integrated framework for modeling and metascheduling scientific workflow applications on Grid resources, we make it easy to build a customized environment with end-to-end support for application Grid deployment, from the management of an application and its dataset, to the automatic execution and analysis of its results.
Learning From Our Patients: Complications and the Future of Radical Cystectomy for Bladder Cancer

The scope of minimally invasive laparoscopic and robotic techniques for urological surgery has expanded vastly during the last decade. These techniques hold the promise of applying modern surgical technology to decrease patient morbidity and improve surgical outcomes. Application of minimally invasive techniques in urology may yield the most significant clinical impact for treatment of bladder cancer by potentially decreasing the morbidity traditionally associated with radical cystectomy. Long considered the gold standard for muscle invasive bladder cancer, radical cystectomy has significant morbidity and mortality compared to other urological operations, even when performed by experienced surgeons at tertiary medical centers. In this month’s video entitled “Early oncologic outcomes & postoperative complications following robotic radical cystectomy” (http://www.auanet.org/dev/pat/ video/video.cfm?play2010/V1699.mp4&main2) Wang et al describe their technique of robotic assisted laparoscopic radical cystectomy. Acceptable pathological and perioperative outcomes were demonstrated in a cohort of 85 patients. Positive margin rate was 6% (all occurring with pT3 or greater disease), overall complication rate at 30 days 40% and major complication rate at 30 days (modified Clavien grade 3 or greater) 10%. Several similar case series have shown that minimally invasive techniques can be effectively used to treat bladder cancer with good operative and pathological outcomes. However, long-term oncologic outcomes and potential perioperative advantages in minimizing morbidity have yet to be fully realized. 1‐3
Sex, Breastfeeding, and Marital Fertility in Pretransition China

The present study addresses the debate over low marital fertility in pre-demographic transition China. The debate long-running and spirited began when Princeton demographers led by George Barclay derived fertility estimates from John Lossing Bucks Chinese Farm Survey of 1929-31 and concluded that pretransition China had a natural fertility regime at very low levels relative to historical European populations. Incredulous that a society so manifestly pronatal could have such low marital fertility Arthur Wolf (1984) questioned the quality of the historical fertility data while Ansley Coale (1984) defended it. The debate might have ended there except that James Lee Wang Feng and Cameron Campbell in a series of books and articles proposed that low marital fertility in China could be explained in part by "marital restraint" a term that subsumes both customary low coital frequency and deliberate restraint from coitus. Wolf (2001) objected vigorously proposing that poverty and malnutrition but certainly not spousal volition might explain low fertility. The "revisionists" mounted further defense of their thesis (Lee Campbell and Wang 2002) even declaring deliberate control to be "the most distinctive feature of Chinese marital fertility". (excerpt)
Medicaid, State Finances, and the Bottom Line for Businesses

Current Medicaid expenditures account for about nine percent of the federal budget and almost a quarter of state budgets and are growing rapidly. State Medicaid budgets are especially vulnerable to recession since states cannot incur large and sustained fiscal deficits. Without change, Medicaid burdens will cause state finances to be diverted from infrastructure and education, with negative effects on the costs and productivity of business. Also affecting business are the state governments experimenting with policies that shift Medicaid burdens to private employers. Simultaneously, the states are initiating efforts to ease Medicaid's relentless cost increases and address its long-run problems.
Current sensing with metal-coated multimode optical fibres

A multimode fibre has been used to detect electrical currents. The optical fibre which serves as the sensor is coated with a thick Al metal jacket. Electromotive forces on a wire in a magnetic field are used to induce differential phase shifts between the fibre modes. Good linearity has been observed in the 5 to 2000 mA current range.
Planning for Impacts of Climate Change at U.S. Ports

U.S. ports need to better understand climate change and how it may affect them. In the coming decades, ports are likely to experience higher sea levels and storm surges, as well as other direct and indirect impacts, due to climate change. Most ports do not appear to be thinking about, let alone actively preparing to address, the effects of climate change. Ports do not have specific information about either the types of impacts that they can expect on their facilities or the probabilities of different types of impacts occurring. Although climate change science is making considerable advances, projections of impacts at levels smaller than the regional scale are not available. In addition, ports' typical planning processes are ill equipped to respond to the high levels of uncertainty associated with the impacts of climate change, the timescales of climate change, and the geographical scale of climate change. The data that ports typically use for planning purposes do not incorporate climate change forecasts. ...
How Grain Growth Stops: A Mechanism for Grain-Growth Stagnation in Pure Materials

The thermodynamic equilibrium state of crystalline materials is a single crystal; however, polycrystalline grain growth almost always stops before this state is reached. Although typically attributed to solute drag, grain-growth stagnation occurs, even in high-purity materials. Recent studies indicate that grain boundaries undergo thermal roughening associated with an abrupt mobility change, so that at typical annealing temperatures, polycrystals will contain both smooth (slow) and rough (fast) boundaries. Mesoscale grain-growth models, validated by large-scale polycrystalline molecular dynamics simulations, show that even small fractions of smooth, slow boundaries can stop grain growth. We conclude that grain-boundary roughening provides an alternate stagnation mechanism that applies even to high-purity materials.
High-resolution, serial intravital microscopic imaging of nanoparticle delivery and targeting in a small animal tumor model.

Nanoparticles are under active investigation for the detection and treatment of cancer. Yet our understanding of nanoparticle delivery to tumors is limited by our ability to observe the uptake process on its own scale in living subjects. We chose to study single-walled carbon nanotubes (SWNTs) because they exhibit among the highest levels of tumor uptake across the wide variety of available nanoparticles. We target them using RGD (arginine-glycine-aspartic acid) peptide which directs them to integrins overexpressed on tumor vasculature and on the surface of some tumor cells (e.g., U87MG as used here). We employ intravital microscopy (IVM) to quantitatively examine the spatiotemporal framework of targeted SWNT uptake in a murine tumor model. IVM provided a dynamic microscale window into nanoparticle circulation, binding to tumor blood vessels, extravasation, binding to tumor cells, and tumor retention. RGD-SWNTs bound to tumor vasculature significantly more than controls (P<0.0001). RGD-SWNTs extravasated similarly compared to control RAD-SWNTs, but post-extravasation we observed as RGD-SWNTs eventually bound to individual tumor cells significantly more than RAD-SWNTs (p<0.0001) over time. RGD-SWNTs and RAD-SWNTs displayed similar signal in tumor for a week, but over time their curves significantly diverged (p<0.001) showing increasing RGD-SWNTs relative to untargeted SWNTs. We uncovered the complex spatiotemporal interplay between these competing uptake mechanisms. Specific uptake was delimited to early (1–6 hours) and late (1–4 weeks) time-points, while non-specific uptake dominated from 6 hours to 1 week. Our analysis revealed critical, quantitative insights into the dynamic, multifaceted mechanisms implicated in ligand-targeted SWNT accumulation in tumor using real-time observation.
Wet etching study of silica glass after CW CO2 laser treatment

Abstract Silica glass is one of the most important materials in optical and electronic applications. We have investigated the wet etching characteristics of silica glass in a buffered hydrofluoric acid (BHF) solution after a thermal treatment with a CW CO2 laser. The etch rate at the center of the treated region is found to increase by approximately 100% compared to the untreated glass. This shows that the fast thermal cycle experienced by glass as a result of the laser processing changes microstructure, as characterized by an increase in fictive temperature. Thermally manipulating the microstructure of silica glass with a laser may prove to be an important new fabrication technique for integrated optics.
Influence of sexual sensation-seeking on factors associated with risky sexual behaviour among African-American female adolescents

Background The identification of antecedents to sexual risk among youth is critical to the development and dissemination of multilevel interventions. Therefore, the aim of the present study was to examine the effect of sexual sensation-seeking on partner age, partner communication, and the sexual attitudes and behaviours of African-American female youth. Methods: This study examined survey data collected by audio computer-assisted self-interviews from 701 young African-American females between 14 and 20 years of age. The survey consisted of items designed to measure adolescents’ sexual risk and preventive behaviours. Results: The results of this study suggest that sexual sensation-seeking is associated with condom use among adolescent African-American females. For adolescents who reported greater sexual sensation-seeking, lower levels of sexual happiness were associated with a decreased likelihood of condom use at last intercourse (β = 1.01, P ≤ 0.05). For those reporting lower levels of sexual sensation-seeking, greater sexual enjoyment was associated with a greater likelihood of condom use at last intercourse (β = 0.93, P ≤ 0.01). Adolescents with younger sexual partners and lower levels of sexual sensation-seeking reported a higher proportion of condom use in the past 6 months (β = 0.70, P = 0.01). Higher partner communication self-efficacy and decreasing levels of sexual sensation-seeking were associated with fewer lifetime sexual partners (β = –0.54, P ≤ 0.05). Conclusions: Future research should address the impact of these variables on adolescent relationship dynamics and sexual decision-making.
Evaluating the behavioral impairment of escaping fish can help measure the effectiveness of bycatch reduction devices

Abstract The behavior of roundfish excluded from an ocean shrimp ( Pandalus jordani ) trawl with a deflecting grid was studied using underwater video. The main study objective was to evaluate the condition of escaping eulachon ( Thaleichthys pacificus ), a species considered “threatened” under the United States Endangered Species Act. Observed behaviors were quantified in relation to a proposed model of an ideal trawl escapement based on an actively swimming fish avoiding contact with the grid. This model of avoidance-based escapement assumed that a roundfish in excellent condition would, (1) maintain distance from the grid, (2) avoid physical contact with the grid, (3) maintain a forward swimming orientation, and (4) maintain an upright vertical orientation. Of the species and size classes of fish encountered, large eulachon (approximately 170–240 mm total length) came closest to the proposed model of avoidance-based escapement, indicating less behavioral impairment than other species. Small eulachon ( P Merluccius productus ) frequently showed signs of fatigue, including sliding along or laying on the grid, exiting the trawl in physical contact with the grid or failing to maintain an upright vertical orientation throughout their escape. Lingcod ( Ophiodon elongatus ) and juvenile rockfish ( Sebastes ) were intermediate in their escape behavior between Pacific hake and large eulachon. They more frequently maintained an upright vertical orientation throughout their escape than Pacific hake, but also showed signs of fatigue, such as sliding along the grid or exiting the trawl in physical contact with the grid. Our data suggest that observing escape behaviors provides additional useful information to evaluate the effectiveness of bycatch reduction devices in reducing fishery-related mortality rates.
Final accent vs. no accent: utterance-final neutralization in Tokyo Japanese

Abstract The distinction in standard Tokyo Japanese between final accent and no accent is ordinarily said to be neutralized utterance-finally. Measuremens of f0in tokens produced by four speakers participating in a preliminary experiment indicate that one of the speakers makes a distinction in production. The results of a follow-up experiment show that this speaker is also capable of perceiving a distinction in her own forms with significantly greater than chance accuracy. This speaker’s performance may reflect an individual difference or a dialect difference. This work complements the pioneering research by Sugito (1982), which remains the standard reference on this topic.
Testing times for genomics

In a bid to popularize the science and ethics of human genetics, two new books fail to address developments in gene testing since completion of the Human Genome Project, says Kathy Hudson.
Nonanticoagulant Heparin Prevents Coronary Endothelial Dysfunction After Brief Ischemia-Reperfusion Injury in the Dog

Background —Coronary endothelial dysfunction after brief ischemia-reperfusion (IR) remains a clinical problem. We investigated the role of heparin and N -acetylheparin, a nonanticoagulant heparin derivative, in modulating coronary endothelial function after IR injury, with an emphasis on defining the role of the nitric oxide (NO)–cGMP pathway in the heparin-mediated effect. Methods and Results —Male mongrel dogs were surgically instrumented, and the effects of both bovine heparin and N -acetylheparin on coronary endothelial vasomotor function, expressed as percent change from baseline flow after acetylcholine challenge, were studied after 15 minutes of regional ischemia of the left anterior descending artery (LAD) followed by 120 minutes of reperfusion. In dogs treated with placebo (saline), coronary vasomotor function was significantly ( P ≤0.03) decreased after 15 and 30 minutes of reperfusion (65±12% and 73±12%) compared with preischemia (103±6%). In contrast, the vasodilatory response to the endothelium-independent vasodilator sodium nitroprusside was maintained during reperfusion. Preischemic administration of both bovine heparin and N -acetylheparin (6.0 mg/kg IV) preserved coronary endothelial function throughout reperfusion. In a parallel group of dogs, nitrate/nitrite (NOx) and cGMP levels in the LAD were measured after treatment and during 15-minute reperfusion. Preischemic administration of N -acetylheparin caused a significant increase in basal NOx and cGMP levels compared with saline controls. Pretreatment with N -acetylheparin also caused a significant increase in NOx and cGMP levels in the LAD after 15 minutes of reperfusion compared with IR alone. Conclusions —These results suggest that heparin preserves coronary endothelial function after brief IR injury by a mechanism independent of its anticoagulant activity and that the effect of heparin may be mediated in part by activation of the NO-cGMP pathway.
Methylation of Mouse Liver DNA Studied by Means of the Restriction Enzymes Msp I and Hpa II

The restriction enzymes Hpa II and Msp I both recognize the sequence 5'-CCGG (C, cytosine; G, guanine). However, Hpa II cuts mouse liver DNA to fragments four times larger than does Msp I. The size of DNA cut by Msp I is close to that predicted from base composition and nearest neighbor analysis. The most probable explanation of these results is that in mouse the site 5'-CCGG is highly methylated.
Designing good MapReduce algorithms

An introduction to designing algorithms for the MapReduce framework for parallel processing of big data.
Science and the City: Thinking Geospatially about Opportunity to Learn

The purpose of this article is to describe several conceptual areas that warrant attention by scholars and practitioners interested in improving access and opportunity to science, technology, engin...
Study of the thermal diffusion behavior of alkane/benzene mixtures by thermal diffusion forced rayleigh scattering experiments and lattice model calculations.

In this work the thermal diffusion behavior of binary mixtures of linear alkanes (heptane, nonane, undecane, tridecane, pentadecane, heptadecane) in benzene has been investigated by thermal diffusion forced Rayleigh scattering (TDFRS) for a range of concentrations and temperatures. The Soret coefficient ST of the alkane was found to be negative for these n-alkane/benzene mixtures indicating that the alkanes are enriched in the warmer regions of the liquid mixtures. For the compositions investigated in this work, the magnitude of the Soret coefficient decreases with increasing chain length and increasing alkane content of the mixtures. The temperature dependence of the Soret coefficient depends on mixture composition and alkane chain length; the slope of ST versus temperature changes from positive to negative with increasing chain length at intermediate compositions. To study the influence of molecular architecture on the Soret effect, mixtures of branched alkanes (2-methylhexane, 3-methylhexane, 2,3-dimet...
Pharmacy Review: Lifestyle Approaches to Anxiety and Depression The Pharmacists' Perspective

Medication is usually the first option of choice for treatment of anxiety and depression. However, the emerging body of evidenced-based research on lifestyle measures to prevent or treat anxiety and depression deserves consideration in all patients. Ways that pharmacists can support lifestyle modification for individuals with anxiety or depressive disorders include the use of screening tools, counseling using open-ended interview techniques, and being aware of reasons people are seeking over-the-counter self-care. Ensuring safe use of prescribed medications and avoiding alcohol or other negatively interacting supplements are other ways. Objective counseling on quantities/ amounts of exercise and proper nutrition and smoking cessation should also be included. Finally, encouraging a healthy environment and outlook is in order. Because mental health disorders affect every aspect of an individual's life, whole-person health measures are vital for overall success.
The tobacco use research program at Oregon Research Institute

Summary The research program at ORI deals with both adolescent and adult tobacco use and is guided by a behavioral framework which emphasizes the role of the social context in tobacco use onset, maintenance and cessation. Growing appreciation of the importance of social context variables, combined with an emerging recognition of the need for a public health rather than clinical perspective on tobacco use, have led to a focus on interventions in larger social systems such as schools, worksites, health care plans, and communities. This research requires attention to the science of behavior change at both the individual and organizational levels.
On the set of covolumes of lattices for Fuchsian buildings

Abstract We construct a nonuniform lattice and an infinite family of uniform lattices in the automorphism group of a Fuchsian building. We use complexes of groups and basic facts about spherical buildings. A consequence is that the set of covolumes of lattices for this building is nondiscrete. To cite this article: A. Thomas, C. R. Acad. Sci. Paris, Ser. I 344 (2007).
Pathogenesis of osteoporosis: concepts, conflicts, and prospects

Osteoporosis is a disorder in which loss of bone strength leads to fragility fractures. This review examines the fundamental pathogenetic mechanisms underlying this disorder, which include: (a) failure to achieve a skeleton of optimal strength during growth and development; (b) excessive bone resorption resulting in loss of bone mass and disruption of architecture; and (c) failure to replace lost bone due to defects in bone formation. Estrogen deficiency is known to play a critical role in the development of osteoporosis, while calcium and vitamin D deficiencies and secondary hyperparathyroidism also contribute. There are multiple mechanisms underlying the regulation of bone remodeling, and these involve not only the osteoblastic and osteoclastic cell lineages but also other marrow cells, in addition to the interaction of systemic hormones, local cytokines, growth factors, and transcription factors. Polymorphisms of a large number of genes have been associated with differences in bone mass and fragility. It is now possible to diagnose osteoporosis, assess fracture risk, and reduce that risk with antiresorptive or other available therapies. However, new and more effective approaches are likely to emerge from a better understanding of the regulators of bone cell function.
NASA's small aircraft costs versus automobile costs and the economic value of traveler time

Abstract This paper presents the results of a study which examined the premise that NASA's Small Aircraft Transportation System (SATS) concept will be seen as an economical alternative to automobiles, when considering the economic value of a traveler's time. Grounded in previous research into SATS Life Cycle Costs, Travel$ense software was used to examine three levels of cost of a hypothetical SATS aircraft versus that of an automobile, traveling among city pairs in Florida. On the whole, NASA's premise about the contribution of the value of time, to the validity of the SATS concept, received qualified support. Without considering the value of time, the SATS aircraft was not found to be economically competitive with autos. When considering the value of time, SATS emerged as an economically viable mode of business transportation.
STUDIES ON THE ANTIGENIC COMPOSITION OF GROUP A HEMOLYTIC STREPTOCOCCI : I. EFFECTS OF PROTEOLYTIC ENZYMES ON STREPTOCOCCAL CELLS.

1. Proteolytic enzymes destroy the type-specific M antigen of group A hemolytic streptococci not only when the M substance is contained in cell-free extracts but also when it is a component of the living cell. 2. The injection of enzyme-treated cultures into rabbits fails to induce the formation of M antibodies, but does result in the production of T antibodies and, therefore, provides a method of preparing anti-T sera free from M antibodies. 3. Exposure to these enzymes does not kill the bacteria. Virulence and the ability to form M substance are restored on subculture and animal inoculation. 4. The study of the effect of proteolytic enzymes on group A hemolytic streptococci provides new techniques for analyzing the antigenic composition of these microorganisms.
Classical negation in logic programs and disjunctive databases

An important limitation of traditional logic programming as a knowledge representation tool, in comparison with classical logic, is that logic programming does not allow us to deal directly with incomplete information. In order to overcome this limitation, we extend the class of general logic programs by including classical negation, in addition to negation-as-failure. The semantics of such extended programs is based on the method of stable models. The concept of a disjunctive database can be extended in a similar way. We show that some facts of commonsense knowledge can be represented by logic programs and disjunctive databases more easily when classical negation is available. Computationally, classical negation can be eliminated from extended programs by a simple preprocessor. Extended programs are identical to a special case of default theories in the sense of Reiter.