cssi/SciSciGPT-SciSciNet huggingface dataset:
Monte Carlo simulation of correlation effects in a random bcc alloy

Abstract Results of high-accuracy Monte Carlo simulations of vacancy and tracer diffusion in a random bcc alloy A-B are reported. The vacancy and tracer correlation factors are calculated using the Einstein equation and the mean square displacements in the absence of driving forces. Additionally, the vacancy correlation factor is calculated from the vacancy drift in the presence of a driving force. The results are compared with the predictions of Manning's random alloy model. Good agreement is observed only for the vacancy correlation factor f v, and the atomic correlation factors f A and f B in the impurity limits. In the range of concentrated alloys the Manning model markedly overestimates f A and f B even for relatively small exchange frequency ratios such as w A/w B = 5. The percolation behaviour of f v and f A when w A ≫ w B is analysed in detail. The percolation threshold and the critical exponents are reasonably consistent with other Monte Carlo simulations. By comparison with the Monte Carlo resul...
Information Technology and Strategy: Two Camps, Four Perspectives, One Elusive Goal

A central argument in strategic management is that a firm's resources or capabilities can be sources of competitive advantage, which may lead to superior firm performance. Investments in Information Technology IT resources and capabilities represent one of the largest recurring expenditures made by firms. However, despite the magnitude of these investments and their presumed strategic importance to firms, demonstrating a definitive link between IT resource investments and firm-level performance has remained elusive. A review of the last 25 years of the MIS and Strategy literatures, indicates that each of these 'two camps' has contributed important insights and a strong co-evolutionary relationships, yet the strategic importance of IT lacks clear theoretical grounding and consistent empirical support. To address this deficiency, in this paper we review the theoretical bases for economic value creation to develop taxonomy for the roles and performance implications of IT, which integrates strategic management theory to offer a contingency perspective for how the roles and value of IT will vary in different strategic and environmental contexts. We apply the taxonomy as a lens through which to examine a sample of prominent prior research on the topic. The authors conclude with a discussion highlighting directions for future research.
Landscape ‘Contagion’ in Raster and Vector Environments

Abstract Raster land cover data has been used to construct adjacency matrices by scanning the pixel edges and calculating proportions according to the land cover types joined. Like joins (e.g., forest to forest) are most common because pixel size is typically much smaller than the average patch size. The dominance of like joins (the matrix diagonal) of the adjacency matrix has led to one interpretation of the matrix as landscape contagion (the tendency of land cover to cluster into a few, large patches). Construction of the adjacency matrix in a vector environment results in a different measurement. In a vector environment, land cover patches are not sub–divided into pixels. Therefore, the main diagonal of the adjacency matrix is zero. Construction of an adjacency matrix in a vector environment estimates the evenness of distribution of edge types, not contagion. The same edge type evenness metric is estimated in a raster environment by ignoring the matrix diagonal and re-scaling the off-diagonal elements ...
Psychological Factors in the Antarctic

For the people who live and work in the Antarctic, isolation and extreme physical conditions cause considerable stress. This article reviews psychological research on Antarctic residents, focusing on factors related to the isolation (effective personnel selection, positive adjustment, conflict, and reintegration into the home environment) and factors related to the physical environment (the extreme cold, high altitude, increased radiation, sensory deprivation, and seasonal changes in activity level). Finally, Antarctic research has been applied to the study of future space travel and space station habitation.
Effect of Aspect Ratio on Gurney-Flap Performance

A low-speed wind-tunnel investigation has been undertaken to establish the effect of wing aspect ratio on Gurney-flap performance. Characterization is accomplished using a force balance and flow visualization. The Gurney-flap lift increment due to a shift in the zero-lift angle of attack was observed to scale with that of the lift-curve slope for different aspect ratios. As the aspect ratio reduced, a Gurney flap of greater height was required to maximize aerodynamic efficiency. The dependence of aerodynamic parameters (zero-lift angle of attack, minimum drag coefficient, and lift-curve slope) on the Gurney flap’s height-to-chord ratio was also examined.
Polarization of the auroral electrojet

Consideration of an idealized model of electrojet polarization. Precipitation from the inner edge of the electron plasma sheet creates a density maximum in the auroral-oval ionosphere, which in turn leads to Hall and Pedersen conductance maximums. It is then assumed that a uniform westward convection electric field is imposed on the lower ionosphere before polarization. Field-aligned currents must flow into the ionosphere equatorward and out of the ionosphere poleward of the Hall conductance maximum. As the convection field and ionospheric density increase during the substorm growth phase, the field-aligned current densities should eventually reach an instability threshold beyond which anomalous resistance should produce field-aligned electric fields. The partial blockage of the field-aligned currents produces an equatorward electric field and therefore a partial Cowling conductivity in the lower ionosphere. Rough numerical estimates indicate that the expected field-aligned currents can exceed the stability threshold estimated by Kindel and Kennel (1971), that 1- to 5-kV field-aligned potential drops correspond to significant electrojet enhancement, and that the required energy dissipation of field-aligned currents in the topside ionosphere, a few ergs/per sq cm per sec column, suggests significant topside modification following auroral breakup.
Brain Lesions in Birds: Effects on Discrimination Acquisition and Reversal

Bobwhite quail (Colinus virginianus) with lesions of the cortex and the dorsal portion of the hyperstriatum (or " wulst") showed a considerable deficit in ability to reverse a learned discrimination between horizontal and vertical stripes. Two birds that had been run on 25 such reversals before ablation showed the same result. Lesioned birds did not, however, differ from controls in the Original acquisition of the discrimination. Analysis of performance indicated that the reversal deficit was not due to difficulties in discrimination, interference with motor ability, or lack of motivation. The deficit appeared to be based on perseveration of response to the previous positive stimulus during reversal training.
A Local Instability of Tidally Distorted Accretion Disks

Hydrodynamic accretion disks in binary star systems have local, three-dimensional, approximately incompressible instabilities whose growth rate is linearly proportional to the tidal field of the secondary star. The instability occurs throughout the disk but is most rapid in the outer parts. The free energy for the instability derives from the tidal distortion of the disk rather than its differential rotation. The instability will excite m-parallel 1 internal waves of the type discussed by Vishniac et al. (1992), and it should facilitate return of angular momentum from the disk to the secondary star. It is closely related to a recently discovered instability that has been suggested as a mechanism for transition to turbulence in terrestrial and laboratory flows, but whether it will lead to strong turbulence in disks is as yet unclear.
Fatty Acids as Sensitive Tracers of Sewage Sludge Carbon in a Deep-Sea Ecosystem

Dumping into the open ocean is considered a viable political option to cope with the rapidly increasing global production of municipal sewage sludge. However, before such an option can be justified, the impact of mega-scale dumping upon the marine environment must be fully addressed scientifically. Here we present a methodology whereby the impact of sewage dumping upon deep-sea invertebrates can be tracked. We examined the relative abundances and carbon isotopic compositions of membrane fatty acids of the sea urchin Echinus affinus from one deep-sea site heavily affected by municipal sewage sludge dumping (Sludge Max; Dumpsite DWD 106) and one marginally affected (station 13; 18 km SSE of DWD 106). Such analyses reveal marked differences linked to the relative importance of sewage sludge in diet. 18:2(n-6) is much more abundant in Sludge Max urchins with similar, highly 13 C-depleted isotopic compositions in all samples (δ 13 C = -25.8 to -27.8 %). Conversely, 20:5(n-3), is most abundant in station 13 individuals and has less negative δ 13 C values at both sites (δ 13 C = -20.7 to -22.6 %). We propose that the relative abundance and stable isotopic composition of 18:2(n-6) and 20:5(n-3) can be used to indicate the importance of sewage sludge in the diet of E. affinus.
H 2 -optimal control with an H ∞ -constraint: the state feedback case

In this paper we consider a mixed HZ//-/~-optimal control problem. It is assumed that the plant as well as the feedback controller are finite-dimensional and linear time-invariant, and that the plant state is available for feedback. More specifically, among all the state-feedback controllers that minimize the HE-norm of a closed loop transfer matrix, we give necessary and sufficient conditions for the existence of a controller that also satisfies a prescribed H®-norm bound on some other closed loop transfer matrix. When these conditions are met, the solution to the above problem is also a global solution to the contrained optimization problem of minimizing an HE-norm performance measure subject to an H®-norm constraint. We also give state-space formulae for computing the solutions. Some easily checkable sufficient conditions for the existence of solutions are given. Finally we give an example in which all solutions to the constrained optimization problem are necessarily dynamic, i.e. there is no static gain solution even though plant state is available for feedback.
Manager Intervention with Troubled Supervisors Help and Support Start at the Top

Although research demonstrates the importance of supervisors’ supportive and helping interactions with troubled workers, little is known about how managers help troubled supervisors. Survey data from managers and supervisors in a top manufacturing company revealed that supervisors experienced personal troubles and sought help from informal and formal resources, including their managers. Managers reported supporting and helping troubled supervisors, informally and formally. However, both supervisors’ help seeking and managers’ help giving used more informal than formal processes. Managers’ attitudes about help giving and awareness of supervisors’ problems were associated with their intervention behaviors. This study examines the important role that managers may play in facilitating supportive communication and helping interactions in the workplace.
Testing for Interaction in Studies of Noninferiority

We consider the role of interaction tests in the context of active-controlled clinical trials that aim to demonstrate the noninferiority of an experimental treatment compared to a standard (control) treatment. When the subjects can be grouped into strata (e.g., study sites, gender, race, etc.), there may be a desire to determine whether the experimental treatment is noninferior to the standard in each of the strata. We present five possible analysis strategies to test for heterogeneity of relative treatment effects among strata. These strategies are either identical to or straightforward modifications of strategies that can be used to test for interaction when the objective of the study is to show differences rather than noninferiority. The various analysis strategies implicitly depend on different definitions of interaction. Power of the various tests will be low, a phenomenon that often occurs when testing for interaction. We present simulation results to quantify the power and type I error rates under different scenarios and an example to demonstrate the proposed tests. None of the analysis strategies is best under every parameter configuration. The tests may be best used in a descriptive or exploratory manner. Extensions to two-sided equivalence testing are also discussed.
Representable over GF(3) and GF( q ). part I. the number of points

Letq be a prime power not divisible by 3. We show that the number of points (or rank-1 flats) in a combinatorial geometry (or simple matroid) of rankn representable over GF(3) and GF(q) is at mostn2. Whenq is odd, this bound is sharp and is attained by the Dowling geometries over the cyclic group of order 2.
Scalable QoS provisioning for mobile networks using wireless sensors

In the past few years support for mobility has increased to a large extent. Mobile IP enables nodes to move from one network to the other while maintaining the same IP address. Minimal packet loss during handoff is a requirement for provisioning QoS for real-time applications. However, loss of packets during handoff and the best effort service offered by the Internet degrades the quality of applications such as voice and video. High-speed mobility such as those in trains and vehicles further deteriorates the services of such time critical applications. In this paper, the authors propose a new handoff technique based on location tracking by wireless sensor networks. Networks of such sensors perform movement detection of mobile nodes in a particular direction and inform the mobility agent to which the mobile node is attached. This agent looks up the new mobility agent determination table and informs the new agent to which the node is moving. Based on entries in the proposed IP-QoS mapping table, old mobility agent also informs the new agent about the mobile nodes traffic characteristics so it can make reservations in advance. Numerical analysis shows that packet loss during handoff when compared to traditional mobile IP is reduced by as high as 93% and agent utilization increases by 96% at high speeds.
Multiresolution robustness of the probability density of scalar fields and multiscale aspects of scalar interfaces in fully-developed turbulent jets

This work focuses on the probability density function (pdf) of turbulent jet scalar fields with emphasis on the extent to which the pdf depends on resolution scale effects. The interpretation of the scalar pdf in terms of geometrical and physical properties of the turbulent scalar interfaces is utilized. The scalar pdf is examined as the product of the interfacial area–volume ratio, or perimeter–area ratio for two-dimensional data, and the interfacial thickness quantified as the averaged inverse magnitude of the scalar gradient across each interface. Because the area–volume ratio is expected to decrease with reduced resolution, whereas the interfacial thickness is expected to increase with reduced resolution, the possibility arises that the scalar pdf may exhibit only weak sensitivity to resolution scale effects. We demonstrate and investigate this expectation using a high-resolution experimental database of fully-developed turbulent scalar fields and interfaces in jets. Coarse graining is conducted by a ...
On the origin of neumes

How did Latin neumes begin? And what developments lie between those beginnings and the first plentiful documents of neuming which date from about 900? A long line of speculations has failed to produce generally credited answers to these questions. Figure 1 shows a stemma by Joseph Froger that can serve as orientation to the problem. This does not address ultimate origins. Its ‘original’ is the archetypal neumation of the Frankish–‘Gregorian’ mass propers, a lost formation compiled some time after neumatic beginnings. It goes on to the regional neume-species of 900, all ostensible outgrowths of that archetype: Ept – German; Cla – north Italian; Clu – Cluny; Dij – Burgundian; Den – St Denis; Lan – Lorraine or ‘Metz’; Mur 3 – St Gall or ‘Alammanian’; Cha – Breton; Alb – Aquitanian; Ben – south Italian/Beneventan. Between the unknown ‘original’ and the multiple neume-species around 900 an obscure evolution takes place. There is, in Froger's words, ‘une sorte de nuee opaque… [une] zone brumeuse’.
Rome: Performance and Anonymity using Route Meshes

Deployed anonymous networks such as Tor focus on delivering messages through end-to-end paths with high anonymity. Selection of routers in the anonymous path construction is either performed randomly, or relies on self-described resource availability at routers, making systems vulnerable to low-resource attacks. In this paper, we investigate an alternative router and path selection mechanism for constructing efficient end-to-end paths with low loss of path anonymity. We propose a novel construct called a "route mesh," and a dynamic programming algorithm that determines optimal-latency paths from many random samples using only a small number of end-to-end measurements. We prove analytically that our path search algorithm finds the optimal path, and requires exponentially lower number of measurements compared to a standard measurement approach. In addition, our analysis shows that route meshes incur only a small loss in anonymity for its users.
Perceived Professional Discrimination against the EdD Psychologist

Informal observations have hinted at a persistent tendency for both academic and professional hiring authorities to discriminate against individuals who hold the EdD rather than the PhD. The present investigation used a mail questionnaire to evaluate the extent of professional prejudice experienced by EdDs in psychology and found that of 69 usable returns out of 158, 39% had experienced discrimination associated with their degrees. There was a significant difference in fathers' occupations for those who had and had not experienced discrimination, but the two groups showed no differences on sex, age, or salary; and there were no distinctions on the basis of undergraduate major or the proportion who earned their doctorates from universities having highly rated psychology departments. Types of discrimination are described, a suggested explanation of the status difference is offered and a recommendation is made for further research and more discussion of this matter.
PRODUCTIVITY OF HONEYBEES IN OIL PALM INTEGRATED SYSTEM IN NIGER- DELTA OF NIGERIA

For two consecutive years in Abbi, Delta State of Niger-Delta of Nigeria one, two and three beehives were integrated in oil palm plantation to determine optimum productivity of the oil-palm honey bee farming system. The fresh fruit bunch (economic yield) of the oil palm was statistically similar at 0, 1, 2 and 3 bee hive(s) per hectare. The honey yield were statistically similar for each bee hive/kg/ha while the total honey yield/production was significantly higher in the order of three > two > one bee hive/ha. Result obtained in this study indicates that productivity of oil palm plantation + three Beehives/ha which produced more honey is recommended. The Journal of Agriculture and Environment Vol:12, Jun.2011, Page 38-40 DOI: http://dx.doi.org/10.3126/aej.v12i0.7561
Motivations for infidelity in heterosexual dating couples: The roles of gender, personality differences, and sociosexual orientation

A motivational/individual differences model of infidelity is proposed in the course of empirically evaluating the traditional dichotomy between emotional and sexual motives. A scale assessing motivations for infidelity was developed and administered to 432 college students, 120 of whom reported past dating infidelity. Four motivations were identified and were associated as predicted with Big Five and other trait constructs; Sex was predicted by male gender, lower age, and unrestricted sociosexual orientation (SO); Dissatisfaction was predicted by female gender and Extraversion; Neglect was predicted by Neuroticism; and Anger by Neuroticism and low Agreeableness. As predicted, a two-factor model provides a poorer fit with the data than a multi-factor model. Unrestricted SO partially mediates the gender difference in endorsement of a sex motive for infidelity.
Arthroscopic excision of a ganglion cyst from the elbow

Ganglia are benign lesions that are uncommonly seen about the elbow. When conservative treatment fails, surgical excision is recommended, usually through an open approach. The author presents the first report of a case of arthroscopic excision of a large anterior elbow cyst. The success of the excision, documented by magnetic resonance imaging at 18 months postoperatively, shows that the arthroscopic approach is a safe and viable alternative to open excision of ganglion cysts of the elbow.
A new publisher for the Journal of Infectious Diseases.

The Journal of Infectious Diseases (JID) has been published by the University of Chicago Press from its inception in 1904 until now. Over that time, JID became a premier vehicle for the publication of original and high-quality infectious disease research. With this issue, we embark on a new venture as publication of both JID and our sister journal, Clinical Infectious Diseases (CID), moves from the University of Chicago Press to Oxford University Press. This transition is bittersweet. The University of Chicago Press has served us exceedingly well. JID subscriptions number over 12,000 and manuscript submissions over 2000 per year. The quality and impact of JID research articles are recognized throughout the world. JID has a truly international scope, with over 50% of manuscripts submitted from outside the United States, an average of approximately 18 countries represented in each issue, and an editorial advisory board consisting of members from 23 different countries. And yet there is always room for improvement. Two years ago, our parent organization, the Infectious Diseases Society of America (IDSA), initiated a publisher-renewal search for JID and CID. Many publishers submitted detailed proposals, and after a rigorous competition, Oxford University Press was chosen as the new publisher. Although we will miss our interactions with the University of Chicago Press, we welcome Oxford to our family. Oxford University Press had its origins in the late 15th century with the revolutionary introduction of printing from movable type. It is the oldest and largest university press in the world, with major publishing centers in England and the United States. More than 250 academic and research journals are published by Oxford, many of them in medical and scientific fields. In addition to serving resource-rich countries, Oxford University Press provides free or reduced-cost online access where it is needed, and more than 2500 educational institutions benefit from Oxford University Press initiatives. So what can readers and authors expect from JID’s new association with Oxford University Press? A few examples follow.
Sphingosine-1-phosphate phosphohydrolase regulates endoplasmic reticulum-to-golgi trafficking of ceramide.

Previous studies demonstrated that sphingosine-1-phosphate (S1P) phosphohydrolase 1 (SPP-1), which is located mainly in the endoplasmic reticulum (ER), regulates sphingolipid metabolism and apoptosis (H. Le Stunff et al., J. Cell Biol. 158:1039-1049, 2002). We show here that the treatment of SPP-1-overexpressing cells with S1P, but not with dihydro-S1P, increased all ceramide species, particularly the long-chain ceramides. This was not due to inhibition of ceramide metabolism to sphingomyelin or monohexosylceramides but rather to the inhibition of ER-to-Golgi trafficking, determined with the fluorescent ceramide analog N-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-pentanoyl)-d-erythro-sphingosine (DMB-Cer). Fumonisin B1, an inhibitor of ceramide synthase, prevented S1P-induced elevation of all ceramide species and corrected the defect in ER transport of DMB-Cer, readily allowing its detection in the Golgi. In contrast, ceramide accumulation had no effect on either the trafficking or the metabolism of 6-([N-(7-nitrobenzo-2-oxa-1,3-diazol-4-yl)amino]hexanoyl)-sphingosine, which rapidly labels the Golgi even at 4°C. Protein trafficking from the ER to the Golgi, determined with vesicular stomatitis virus ts045 G protein fused to green fluorescent protein, was also inhibited in SPP-1-overexpressing cells in the presence of S1P but not in the presence of dihydro-S1P. Our results suggest that SPP-1 regulates ceramide levels in the ER and thus influences the anterograde membrane transport of both ceramide and proteins from the ER to the Golgi apparatus.
Laboratory Simulation of Urban Runoff and Estimation of Runoff Hydrographs with Experimental Curve Numbers Implemented in USEPA SWMM

The prognostic capabilities of a lumped hydrologic modeling approach may be complicated by routing and connectivity among infiltrative and impervious surfaces. We used artificial rainfall to generate runoff from impervious and bare soil boxes arranged in series to simulate different extents and connectivity of impervious surfaces under different moisture conditions for pervious areas. Curve numbers were calculated from observed rainfall and runoff data, compared with published values, and used in the curve number infiltration algorithm in the U.S. EPA Storm Water Management Model 5 (USEPA SWMM5) to generate runoff hydrographs. Experimental curve numbers were higher than tabular USDA values, ranging from 91 to 96. Simulations of infiltration and runoff response with experimental curve numbers showed overall good agreement with observed data, although SWMM5 was unable to re-create early term infiltration patterns, and simulated runoff lagged observed, which is attributed to implicit accounting for soil moisture and other assumptions of the SWMM5 curve number application. Our results highlight some prospects for the use of curve numbers in modeling infiltration and runoff.
Teachers' Beliefs about English Language Learners in the Mainstream Classroom: A Review of the Literature.

This literature review on teachers' beliefs about English language learners (ELLs) in mainstream classrooms is organized into three sections: (a) inservice teachers' existing beliefs, (b) predictors of inservice teachers' beliefs, and (c) the connection between inservice teachers' beliefs and practices. This body of literature points to a clear need for increased professional development for mainstream teachers because, currently, teacher education possesses a “poverty of language learning.” According to the research included in this review, a relation exists between beliefs and practices in relation to teaching ELLs in mainstream classrooms. Certain factors, such as training in teaching ELLs, years of teaching experience, and exposure to language diversity, have been identified as predictors of mainstream teachers' beliefs about English to speakers of other languages students. It is important for teachers who hold deficit beliefs toward ELLs to adopt a new set of beliefs for successful inclusion of ELLs.
An Exploratory Examination of Social Ties and Crime in Mobile Home Communities

Guided by the systemic model of social disorganization, the purpose of this study was to explore the nature of social ties in mobile home communities and examine how that relates to rates of violent and property crime. Interviews with a small sample of mobile home residents, owners, and managers in Omaha, Nebraska, indicate a wide spectrum of communities, from those characterized by an atomized population to those with strong social ties. Fear of crime, ethnically heterogeneous populations, and lax management were cited by respondents as factors that undermined relationships. Proactive management and a desire to help neighbors were cited by respondents as factors that helped strengthen relationships. Violent and property crime rates for the mobile home communities were largely consistent with the interview data, providing support for the importance of social networks and a systemic model of social disorganization. The implications of these findings for research and policy are also explored.
Reproducibility of the Oral Glucose Tolerance Test in Overweight Children

Objective: We examined the reproducibility of the oral glucose tolerance test (OGTT) in overweight children and evaluated distinguishing characteristics between those with concordant vs. discordant results. Design: Sixty overweight youth (8–17 yr old) completed two OGTTs (interval between tests 1–25 d). Insulin sensitivity was assessed by the surrogate measures of fasting glucose to insulin ratio, whole-body insulin sensitivity index, and homeostasis model assessment of insulin resistance, and insulin secretion by the insulinogenic index with calculation of the glucose disposition index (GDI). Results: Of the 10 subjects with impaired glucose tolerance (IGT) during the first OGTT only three (30%) had IGT during the second OGTT. The percent positive agreement between the first and second OGTT was low for both impaired fasting glucose and IGT (22.2 and 27.3%, respectively). Fasting blood glucose had higher reproducibility, compared with the 2-h glucose. Youth with discordant OGTTs, compared with those with concordant results, were more insulin resistant (glucose/insulin 2.7 ± 1.4 vs. 4.1 ± 1.8, P = 0.006, whole-body insulin sensitivity index of 1.3 ± 0.6 vs. 2.2 ± 1.1, P = 0.003, and homeostasis model assessment of insulin resistance 10.6± 8.1 vs. 5.7 ± 2.8, P = 0.001), had a lower GDI (0.45 ± 0.58 vs. 1.02 ± 1.0, P = 0.03), and had higher low-density lipoprotein cholesterol (117.7 ± 36.6 vs. 89.9 ± 20.1, P = 0.0005) without differences in physical characteristics. Conclusions: Our results show poor reproducibility of the OGTT in obese youth, in particular for the 2-h plasma glucose. Obese youth who have discordant OGTT results are more insulin resistant with higher risk of developing type 2 diabetes mellitus, as evidenced by a lower GDI. The implications of this remain to be determined in clinical and research settings.
Chirale Erkennung in π‐Komplexen von Alkenen, Aldehyden und Ketonen mit Übergangsmetall‐Lewis‐Säuren; Entwicklung eines allgemeinen Modells für enantiofaciale Komplexierungsselektivitäten

Prochirale Alkene, Aldehyde und Ketone sind die am haufigsten verwendeten Ausgangsmaterialien fur die enantioselektive organische Synthese. Viele Methoden bedienen sich chiraler Verbindungen, z.B. Lewis-Sauren, die mit den Alkenen, Aldehyden und Ketonen zwei diastereomere Addukte bilden konnen, deren Verhaltnis ein Mas fur die „chirale Erkennung” ist. Die diastereomeren π-Komplexe unterscheiden sich darin, welche der beiden enantiotopen Seiten der CC- oder OC-Gruppen an die Lewis-Saure gebunden ist. Hier wird erstmals eine umfassende Analyse solcher Gleichgewichte und verwandter Komplexierungsphanomene chiraler Ubergangsmetall-Lewis-Sauren vorgenommen. Die Auswertung einer Fulle an Daten, die im Laboratorium der Autoren mit dem pyramidalen Rheniumkomplexfragment [(η5-C5H5)Re(NO)-(PPh3)]+ erarbeitet wurden, ergab besonders klare Einblicke. Literaturdaten fur andere Komplexe wurden ebenfalls zusammenfassend berucksichtigt. Basierend auf den relativen sterischen Eigenschaften von vier Quadranten wird ein allgemeines Modell fur die chirale Erkennung prasentiert. Dies ermoglicht es, Komplexierungsselektivitaten fur verschiedene Ligandenklassen individuell und rational zu optimieren. Auch elektronische Effekte werden herausgearbeitet und mit spezifischen Struktureigenschaften korreliert. Ferner werden Beziehungen zwischen Komplexierungsgleichgewichten, Reaktivitaten und Produktkonfigurationen diskutiert.
Modeling of Li-Air Batteries with Dual Electrolyte

Li-air batteries with organic electrolyte at the anode and aqueous electrolyte at the cathode (dual electrolyte systems) are modeled using the mass transport and drift-diffusion equations of the electrolyte during the discharge of the cells. Two regimes of operation are analyzed: (1) when the concentration of the electrolyte is smaller than the concentration of saturation of Li + OH in water, and (2) when the electrolyte concentration reaches saturation and the reaction product is deposited at the cathode. Numerical simulations are performed to evaluate the dependence of the specific capacity, energy and power densities on the geometrical and material parameters during the two regimes of operation. It is shown that the energy density and specific capacity can be improved by increasing the solubility and the diffusion coefficient of oxygen in the cathode, but they are not much affected by adding a uniformly distributed catalyst in the cathode. The power density can be increased by 10% by increasing the solubility factor, the oxygen diffusion coefficient, or the reaction rate. The limiting factors for the low power density of these batteries are the low values of the oxygen diffusion coefficient in the cathode and the relatively high separator/anode and separator/cathode interface resistances.
Legitimizing Family Management: The Role of Adolescents' Understandings of Risk

Few studies use the kinds of rich qualitative data that permit the analyst to probe for the numerous ways that contextual demands could explain adolescents' interpretations of the socialization processes within their families. Using inductive techniques, the author analyzed Black adolescents' (N = 64) interpretations of their parents' expectations and rules. Several findings emerged. First, agreeing with parents' assessments of risk was critical to participants' acceptance of family management. Second, participants legitimized their parents' practices as helping them avoid the risks of getting in trouble with the law, acquiring a disreputable identity, and failing to ascend the class ladder. Third, boys and girls legitimized different expectations and rules because they experienced and assessed risks in gender-specific ways. The author argues that adolescents bring an understanding of risk to bear on their interpretations of family life and uses these findings to develop a grounded concept of legitimizing parents' controlling practices.
Changes in cigarette smoking after traumatic spinal cord injury.

Objective The objective of this study is to identify changes in the prevalence of cigarette smoking approximately 1 year after discharge from inpatient rehabilitation for spinal cord injury (SCI). Method Self-report assessments were completed by 129 participants with SCI during initial inpatient rehabilitation and at an average follow-up of 489 days postinjury. Results The prevalence of cigarette smoking declined from 36.4% at the time of SCI onset to 18.8%, and was not significantly different from the general population at follow-up. Conclusions Whereas the prevalence of cigarette smoking is elevated at SCI onset, there are significant decreases in the smoking rate over the first 16 months after onset, indicating significant behavioral change.
Risk of bleeding in cancer patients treated with the angiogenesis inhibitor bevacizumab: A meta-analysis

9584 Background: Bleeding is a serious adverse event associated with bevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor (VEGF) used extensively in the treatment...
TEM Observations of Bio-Conjugated Streptavidin-Gold Nanoparticles

Simultaneous visualization of inorganic nanoparticles and their bio-functionalized coating under the TEM can be achieved with negative staining, where electron dense material is introduced onto the specimen to enhance contrast. Using this technique, streptavidin-functionalized gold nanoparticles were negatively stained using phosphotungstic acid (PTA) at pH 7.0 and then observed using the TEM. The proteins appear as light regions/halos surrounding the gold nanoparticles, with widths similar to those of streptavidin protein molecules reported in literature. Experiments were performed to bio-conjugate streptavidin-gold nanoparticles to biotinylated antibodies and biotinylated actin, and then negatively staining the samples with PTA for TEM analyses. In the first experiment, an increase in halo widths in more than 60% of the particles was observed. In the second experiment, the nanoparticles were found to localize around the long actin filaments. Negative staining is useful for studying bio-functionalized nanoparticles as it enables the proteins surrounding the nanoparticles to be imaged and studied using the TEM.
PTH-017 Safety of self-expandable metal stents for malignant biliary strictures in a district general hospital setting

Introduction Self-expandable metal stent (SEMS) are widely used as first line palliative therapy for unresectable malignant biliary strictures. We present our experience of use of self-expandable metal stents in malignant biliary strictures in a District General Hospital (DGH) setting. Method We conducted a retrospective review on the data of all patients who had undergone an ERCP with a placement of self-expandable metal stent for inoperable malignant biliary strictures between Jan 2009 and Aug 2014. Comprehensive information was gathered with regards to patient’s demographics, procedural indications and procedure success rates. We assessed the stents efficacy, stent patency rates, complications and patient survival rates Results 50 patients were identified and analysed during this period. 60% were females and the mean age was 72 years (range, 35–93 years). The most common underlying diagnoses were Pancreatic carcinoma (60%) and Cholangiocarcinoma (32%) followed by Ampullary Carcinoma (6%) and Lymphoma (2%). Indications for metal stent placement included malignant bile duct stricture (54%), blockage of old stents (42%) and stent migration (4%). 23/50 (42%) patients had previous stent placement (Plastic 18, Metal 5). Of these, 21 stents failed due to blockage either due to biliary sludge or tumour overgrowth while 2 stents had migrated out (both plastic stents). The mean duration of previous stent patency was; plastic 96 days (7–523 days) and metal 237 days (39–595 days). The types of metal stents used were; Fully Covered (28%), Partially Covered (32%) and Uncovered (40%). The mean duration of all metal stents patency was 122 days (range, 7 – 566 days) and there was no statistical difference in terms of duration of stent patency among fully covered, partially covered and uncovered stents. Overall complication rate was 18%, which included Cholangitis (2%) and Stent Blockage (8/50, 16%) mainly due to biliary sludge (6/8). Of these blocked stents 5 were Fully covered, 3 Partial covered, 1 was Uncovered. There were no cases of post ERCP pancreatitis or migration of metal stent. There were no reported cases of procedure related mortality. The mean survival period after metal stent insertion was 161 days (range 9 to 566). Conclusion Self-expandable metal stents offers safe and effective palliative therapy for inoperable malignant biliary strictures and can be safely performed in a district general hospital with low complication rates. High blockage rate of fully covered stents is in our series is unexpected and the reasons for this were not obvious but this would be the subject of further analysis and study. Disclosure of interest None Declared.
Synthetic Drought Scenario Generation to Support Bottom-Up Water Supply Vulnerability Assessments

AbstractExploratory simulation allows analysts to discover scenarios in which existing or planned water supplies may fail to meet stakeholder objectives. These robustness assessments rely heavily on the choice of plausible future scenarios, which, in the case of drought management, requires sampling or generating a streamflow ensemble that extends beyond the historical record. This study develops a method to modify synthetic streamflow generators by increasing the frequency and severity of droughts for the purpose of exploratory modeling. To support management decisions, these synthetic droughts can be related to recent observed droughts of consequence for regional stakeholders. The method approximately preserves the spatial and temporal correlation of historical streamflow in drought-adjusted scenarios. The approach is demonstrated in a bottom-up planning context using an urban water portfolio design problem in North Carolina, a region whose water supply faces both climate and population pressures. Synth...
Continuing Inspiration: Gregorio Weber’s Influence on Understanding the Basis of Allosteric Regulation of Enzymes

In addition to his pioneering work utilizing quantitative fluorescence techniques to study biological macromolecules and assemblies, Gregorio Weber contributed substantially to our understanding of the thermodynamic relationships between different ligand-binding equilibria and subunit association equilibria in proteins. These ideas have proven to be very valuable in clarifying the basis for allosteric modification of enzyme behavior when allosteric ligands act predominantly to modify the affinity of an enzyme’s substrate. Dr. Weber’s influence, both scientific and personal, on the author’s efforts to understand the allosteric behavior of prokaryotic and eukaryotic phosphofructokinase (PFK) in particular is described. These observations not only serve to illuminate the regulatory properties of this important enzyme, but they also, in turn, serve to illustrate the validity of the principles that Weber originally described. Not surprisingly fluorescence techniques have played important roles in elucidating many of these insights.
Looking Back and Looking Forward

This concluding chapter recaps some of the major insights of the earlier chapters of this book. It also points out how these insights can be used to supplement the science education literature on the nature of science discussed in the first chapter. The result is a more philosophically grounded science education literature. Such integration holds promise for strengthening both science education and philosophical approaches to the nature of science as well as providing a more in-depth understanding of scientific knowledge. Additionally, the chapter discusses some of the major areas where further research would be helpful. Although it is often a bit risky to do so, this chapter also makes some suggestions as to how some of the needed research might be fruitfully conducted and it speculates on what some of the results of such research might be. The goal of the chapter is not to offer precise predictions of how things will turn out, but rather, to encourage further research and helpfully gesture to good starting places for such research.
The Effect of Pediatric Specific Hypertrophic Cardiomyopathy Mutations on the Biomechanics of Beta Cardiac Myosin

Hypertrophic cardiomyopathy (HCM) is a genetic disease that affects 1 in 500 people. In infants it is particularly severe and is the leading cause of sudden cardiac death in pediatric populations. A high percentage of HCM is attributed to mutations in beta cardiac myosin, the motor protein responsible for ventricular contraction. This study explores how pediatric-specific HCM mutations in beta cardiac myosin (D239N, H251N, and P710R) alter the biochemical and biomechanical properties of beta cardiac myosin at the molecular and cellular levels. Because these mutations manifest early in life, we hypothesize that they will be more severe than mutations that are not pediatric-specific. We investigated the biomechanical properties of these mutations at the molecular level using a purified S1 domain of human beta cardiac myosin. Specifically, we looked at the effects of these mutations on the ATPase activity and the unloaded velocity (in vitro motility) of beta cardiac S1. Upon comparison with WT beta cardiac S1, we find significant differences between the biomechanical properties of the WT and the pediatric-specific myosin mutations, which are more drastic as compared to mutations that are not pediatric-specific. To fully characterize the system, we are currently performing single molecule optical trap force measurements to determine the intrinsic force of these mutations. Future studies will involve creating iPSC-derived cardiomyocytes to study the mechanics of these mutations at the cellular level. The results from this study will increase the understanding of how genetic mutations that cause HCM lead to the presentation of the disease, and will uncover potential targets for therapeutic design to treat the cause of the disease instead of the symptoms.
Purple nutsedge (Cyperus rotundus) tuber production and viability are reduced by imazapic

Weeds exploit underutilized space, causing economic losses in cropping systems. Weed management tactics alter that underutilized space until the crop can mature and efficiently use that space. One tactic is to reduce the weed propagules (e.g., seeds and tubers) that persist quiescently in the soil, which includes minimizing production and addition of new propagules to the soil. Purple nutsedge is a problematic weed around the globe, persisting between growing seasons as tubers in the soil. Imazapic is a peanut herbicide often used in Georgia for control of purple nutsedge. The objective of the experiment was to evaluate the effect of various rates of imazapic on purple nutsedge tuber production. Single presprouted purple nutsedge tubers were transplanted into outdoor microplots and treated after 6 wk of growth with six rates of imazapic (5 to 140 g ai ha-1) POST. A nontreated control was included. All emerged shoots at the time of application were marked with plastic rings; this allowed for classification of tubers at exhumation as (1) tubers attached to shoots that were emerged at time of application, (2) tubers attached to shoots that emerged after application, and (3) tubers without an aerial shoot during the study. At 7 wk after application, the tubers in the microplots were exhumed, classified, and quantified, and their ability to sprout was evaluated. In the nontreated control, there were 544 total tubers, with a log-logistic regression model describing the declining tuber population with increasing imazapic rate. The rate of imazapic that reduced total tuber population 50% (I50) was 36 g ha-1. In the nontreated control, there were 161 tubers attached to shoots that emerged, as when compared with plots that received an imazapic application that had an I50 = 60 g ha-1 Viability of purple nutsedge tubers was 44% at 70 g ha-1 imazapic, suggesting the action of the herbicide may have rendered the tubers nonviable after new shoots were produced. The final classification of tubers included those that did not have an aerial shoot during the study. These were tubers in which apical dominance suppressed shoot development or were likely the most recent tubers to develop. Of the three classes, the tubers without shoots were the most prevalent in the nontreated control, with 358 tubers and an I50 = 18 g ha-1 Imazapic controls purple nutsedge foliage but also reduces the number of new tubers produced, and overall tuber viability and is a valuable tool in management of the long-term population density of this weed.Nomenclature: Imazapic, purple nutsedge, Cyperus rotundus L., CYPRO.
Re-Evaluation of the Low-Risk Anomaly in Finance via Matching

The long-term success of low-risk stocks over high-risk stocks runs contrary to the basic finance principle that risk is compensated with higher expected returns. Our paper examines this low-risk anomaly using Coarsened Exact Matching to balance high and low-risk stock portfolios on industry, company size, and trading volume. After matching, we find that the low-risk anomaly still exists but has a more muted effect than in previous studies, specially when beta is used as a measure of risk. We also find moments in which the low-risk anomaly does not hold, most notably during the dot-com bubble. To our knowledge, we are the first to apply matching techniques to the study of the low-risk anomaly, and our findings complicate various previous explanations of this phenomenon.