cssi/SciSciGPT-SciSciNet huggingface dataset:
The transferrin receptor expressed by gonococcal strain FA1090 is required for the experimental infection of human male volunteers

Iron, an essential nutrient for most microorganisms, is sequestered by the host to decrease the concentration of iron available to bacterial pathogens. Neisseria gonorrhoeae, the causative agent of gonorrhoea, can acquire iron by direct interaction with human iron-binding proteins, including the serum glycoprotein, transferrin. Iron internalization from host transferrin requires the expression of a bacterial receptor, which specifically recognizes the human form of transferrin. Two gonococcal transferrin-binding proteins have been implicated in transferrin receptor function, TbpA and TbpB. We constructed a gonococcal transferrin receptor mutant without the introduction of additional antibiotic resistance markers and tested its ability to cause experimental urethritis in human male volunteers. The transferrin receptor mutant was incapable of initiating urethritis, although the same inoculum size of the wild-type parent strain, FA1090, causes urethritis in >90% of inoculated volunteers. To our knowledge, this is the first experimental demonstration that a bacterial iron acquisition system is an essential virulence factor for human infection.
A Synthesis of Research on Informational Text Reading Interventions for Elementary Students With Learning Disabilities

This research synthesis was conducted to understand the effectiveness of interventions designed to improve learning from informational text for students with learning disabilities in elementary school (K-5). The authors identified 18 studies through a comprehensive search. The interventions were evaluated to determine treatment effects and to understand implementation and methodological variables that influenced outcomes. Moderate to large effect sizes on researcher-developed measures for cognitive strategy interventions were reported. Interventions that utilized graphic organizers as study guides to support social studies learning were also associated with improved outcomes. The findings are considered within the context of limited implementation of standardized measures. The authors extend findings from previous research by reporting a paucity of interventions to enhance higher-level cognitive and comprehension skills. The majority of reviewed studies targeted fact acquisition and main idea identification, and overall encouraging findings were noted for these skills. Implications for future research are discussed.
Regulation of melanogenesis in B16 mouse melanoma cells by protein kinase C.

Melanogenesis is regulated by a variety of environmental and hormonal factors. In this study, we showed that protein kinase C (PKC) plays a major role in regulating melanogenesis in B16 mouse melanoma cells. Chronic treatment of B16 cells with phorbol dibutyrate resulted in a concentration-dependent loss of density-dependent induction of tyrosinase activity, which correlated positively with a concentration-dependent loss of PKC enzyme activity. In contrast, B16 clones overexpressing PKCα had increased tyrosinase activity. Different phorbol derivatives inhibited tyrosinase activity and depleted cellular PKCα in a manner that reflected their reported tumor-promoting activity. Western blotting analysis showed that phorbol dibutyrate decreased the amount of the brown locus gene product (TRP-1) by 50% and lowered the amount of the albino locus gene product (tyrosinase) to undetectable levels. None of the phorbol derivatives affected the level of the slaty locus protein (TRP-2). The decrease in tyrosinase and TRP-1 protein levels was found to be due to a decrease in the mRNA encoded by these genes. In addition to inhibiting the density-dependent increase in tyrosinase activity, phorbol dibutyrate inhibited some, but not all, of the 8-bromocyclic AMP-induced increase in tyrosinase activity. This was accompanied by a decrease in the amount of tyrosinase protein induced by 8-bromocyclic AMP. Although 8-bromocyclic AMP did not change the level of TRP-1, it did reverse the decrease in the amount of this protein induced by phorbol dibutyrate. The amount of TRP-2 was not altered by any of these agents. These data suggest that PKC regulates melanogenesis primarily by controlling the constitutive expression of tyrosinase and, to a lesser extent, TRP-1. © 1996 Wiley-Liss, Inc.
Proven Innovations and New Initiatives in Ground System Development

The state-of-the-practice for engineering and development of Ground Systems has evolved significantly over the past half decade. Missions that challenge ground system developers with significantly reduced budgets in spite of requirements for greater and previously unimagined functionality are now the norm. Making the right trades early in the mission lifecycle is one of the key factors to minimizing ground system costs. The Mission Operations Strategic Leadership Team at the Jet Propulsion Laboratory has spent the last year collecting and working through successes and failures in ground systems for application to future missions.
INTRACRANIAL HEMORRHAGE ASSOCIATED WITH TANGENTIAL GUNSHOT WOUNDS TO THE HEAD

UNLABELLED Tangential gunshot wounds (TGSWs) to the head are gunshot wounds in which the bullet or bullet fragments do not penetrate the inner table of the skull. OBJECTIVES To determine the occurrence of intracranial hemorrhage (ICH) associated with TGSW to the head and to assess the ability of selected clinical criteria to predict ICH in this patient population. METHODS A retrospective chart review of patients diagnosed as having TGSWs to the head presenting to the ED of Los Angeles County + University of Southern California Medical Center from October 1, 1993, to May 31, 1996. RESULTS Four hundred twenty patients with gunshot wounds to the head presented to the ED. CT confirmed the diagnosis of TGSWs in 154 patients (36.7%). Head CT of patients with TGSWs revealed 25 (16.2%) skull fractures and 37 (24.0%) ICHs. Fourteen (56.0%) skull fractures were depressed. Of patients with a CT-documented TGSW to the head, 23 (16.1%) had a history of a loss of consciousness (LOC), 129 (84.3%) had a normal neurologic examination in the ED, 17 (11.1%) had a Glasgow Coma Scale score (GCS) < 15, and 75 (48.7%) had retained extracranial bullets or bullet fragments. Of all patients with TGSWs to the head, 113 had a GCS of 15 with no LOC and a normal neurologic examination, with 17 of these 113 patients (15.0%) having ICH. One patient died while hospitalized. Fifty-six (36.6%) patients were released home directly from the ED. Five clinical criteria (history of LOC, GCS < 15 on ED presentation, skull fracture, location of TGSW on the skull, and presence of extracranial bullet fragments) were examined to determine their ability to predict ICH. None of these criteria either alone or in combination were adequately predictive of ICH. CONCLUSION In this series, 1 in 4 patients with a TGSW to the head had an ICH. All patients with TGSWs to the head should undergo head CT to rule out depressed skull fractures and ICH.
Correlates of role conflict between physicians and nurse practitioners.

This study examined the relationships between personal, job, and organizational factors and perceived role conflict between physicians and nurse practitioners. Data from 361 nurse practitioners showed that perceived conflict was significantly and negatively correlated with satisfaction, task characteristics, and instrumental leadership style of the supervisory physician. Significantly positive correlations were obtained between conflict and organizational size in terms of number of physicians and nurses in the health-care setting.
Resistance to carbaryl in populations of the parasite Aphytis melinus debach (Hymenoptera: Aphelinidae): Implications for california citrus IPM

Abstract Populations of Aphytis melinus DeBach collected from Valencia orange groves in McFarland and Springville, California, during 1989 were as tolerant to residues of carbaryl as a laboratory-selected (R) strain of the parasite. Bioassays using carbaryl-treated plastic cups were conducted on adult A. melinus collected from the McFarland and Springville orchards prior to and after releases of the R strain into the orchards. Survival of the prerelease colonies collected from both orchards was comparable to that of the laboratory-selected R strain, which suggested that endemic populations of A. melinus in these orchards had developed resistance to carbaryl. Given the high carbaryl tolerance of the endemic A. melinus populations, the establishment and recovery of the R strain could not be confirmed in either orchard. A survey of 11 A. melinus populations collected from citrus orchards during 1990–1991 indicated that resistance had developed in at least one area of California. Four of six colonies collected from the San Joaquin Valley showed high tolerances to carbaryl using the standard bioassay. The four resistant colonies originated from Tulare County, and the two susceptible colonies were from Kern and Fresno counties. Colonies collected outside the San Joaquin Valley in Ventura (n = 1), San Bernadino (n = 1), and Riverside (n = 3) counties showed no evidence of resistance. Concentration/mortality tests using carbaryl-treated plastic cups conducted on populations of A. melinus obtained from two commercial insectaries indicated that both parasite colonies were susceptible. Commercial insectaries mass rear and release the laboratory-selected strain of A. melinus in citrus orchards throughout California. Management strategies for implementing the R strain in citrus pest management systems are discussed.
An Improved Method for Detecting Drug Effects in the Open Field

A double test cross-over design was appiied to the testing of rats in the open ~eld. When used to examine the effects of atropine, chiorpromazine and lysergic acid diethylamide (LSD) on open field be- haviour, this design proved 4- 40 times more sensitive than the previously popular single test design. In no case was the double test design less sensitive. Results are discussed in relation to screening of medically useful
Amphetamine sensitization in reproductively experienced female rats.

Abstract Recent studies have supported the hypothesis that pregnancy and parturition are associated with altered sensitivity of brain dopamine systems. An increased behavioral sensitivity to a direct-acting D1/D2 receptor agonist (apomorphine) has also been observed several weeks after lactation, suggesting that these adaptations are long-lasting. To further characterize this phenomenon, the effects of reproductive experience on behavioral sensitization to an indirect-acting dopamine agonist (amphetamine) in female rats were studied. In two separate experiments, nulliparous and primiparous (12–16 weeks post-weaning) female rats were pretreated with amphetamine (1.0 or 5.0 mg/kg) or vehicle (saline) once daily for 5 consecutive days. After 10 days of withdrawal, all animals were challenged with a low dose of amphetamine (25% of pretreatment dose). Locomotor activity was measured following each drug or vehicle administration. Locomotor sensitization to amphetamine challenge was observed in all animals pretreated with 1 mg/kg, regardless of reproductive experience. In contrast, primiparous animals pretreated with 5 mg/kg amphetamine displayed a significantly larger locomotor response to the challenge compared to nulliparous controls. The findings indicate enhanced behavioral sensitization to amphetamine in reproductively experienced rats, and confirm previous reports of lasting adaptations of dopamine systems following pregnancy and lactation.
Aeromagnetic survey and interpretation, Ascention Island, South Atlantic Ocean

Abstract A detailed aeromagnetic survey of Ascension Island, which was completed in February and March of 1983 as part of an evaluation of the geothermal potential of the island, is described. The aeromagnetic map represents a basic data set useful for the interpretation of subsurface geology. An in situ magnetic susceptibility survey was also carried out to assist in understanding the magnetic properties of Ascension rocks and to aid in the interpretation of the aeromagnetic data. The aeromagnetic survey was interpreted using a three-dimensional numerical modeling program that computes the net magnetic field of a large number of vertically sided prisms. Multiple source bodies of complex geometry were modeled and modified until a general agreement was achieved between the observed data and the computed results. The interpretation indicates northeast- and east-trending elongate bodies of much higher apparent susceptibility than adjacent rocks. The relationship to mapped geologic features such as volcanic vents, dikes and faults suggests that these magnetic sources are zones of increased dike density and of other mafic intrusives emplaced along structures that fed the many volcanic centers. A large magnetic source on the northeastern portion of the island may be the intrusive equivalent of trachyte lavas present at the surface. A low-magnetization area, mainly north and west of Green Mountain, appears to be the most likely area for the presence of a geothermal system at moderate (1–3 km) depth.
Nonlinear ionic pseudopotentials in spin-density-functional calculations

A new method for generating and using first-principles pseudopotentials is developed to treat explicitly the nonlinear exchange and correlation interaction between the core and the valence charge densities. Compared to existing potentials, the new scheme leads to significant improvement in the transferability of the potential. In particular, the spin-polarized configurations are well described with a single potential. The need for separate spin-up and spin-down ionic pesudopotentials is, thus, eliminated. The method can easily be implemented with minimal increase in computational effort. Results for both atoms and solids are demonstrated.
LAW, MORALITY, AND THE GUIDANCE OF CONDUCT

Legal positivism is generally characterized by its commitment to two theses —one negative, the other positive.See, e.g., Jules Coleman, Negative and Positive Positivism, J. LEGAL STUD. 139 (1982), reprinted in Jules L. Coleman, MARKETS, MORALS AND THE LAW 3 (1988). The negative thesis, usually referred to as the “Separability Thesis,” denies any necessary connection between morality and legality. Legal positivists do not require that a norm possess any desirable, or lack any undesirable, moral attributes in order to count as law.
Implementation and application of a method to quantitate 2-D gel electrophoresis patterns†

We describe a system for accurate photometry and analysis of two-dimensional (2-D) gels, and its application to both high and low resolution gels. Image acquisition is video-based and includes methods of data correction necessary for accurate photometry. The analysis is based upon a method described previously by Lutin et al. [8], which we have modified for improved stability and adapted to run on our PDP 11/60 computer. We illustrate analysis of a typical gel with a sequence of images showing the data while Gaussian components are estimated, removed, added and fitted as the iterative algorithm proceeds. We conclude by demonstrating the use of a mathematical curve-of-growth model for calibrating peak volumes vs. protein loading.
A Personal Exposure Sampler for Carbon Monoxide

The catalytic oxidation of carbon monoxide (CO) to carbon dioxide (CO2) in air by Hopcalite is the basis for a personal sampler for carbon monoxide. Four or eight hour integrated samples are obtained by drawing air at 0.5 liter per minute (lpm) through stripping beds of Ascarite and molecular sieve which remove water vapor and CO2 present in the ambient air. The air sample then passes to a preweighed glass U-tube which contains Hopcalite, Ascarite, and anhydrous magnesium perchlorate. After sampling, the U-tube is reweighed; the increase in weight is due to the trapped CO2 from the oxidized CO. At 0.5 lpm and 70°F, the 1.5 g of catalyst in the U-tube convert more than 90% of the CO to CO2. For a four-hour sample in the range of 20 to 100 parts per million (ppm) CO, the relative standard deviation of duplicate measurements is ±6%.
‘I see myself as a different person who [has] acquired a lot …’: Somali female students’ journeys to belonging 1

How do refugee students construct their lives in school in their host country? What are some difficulties that they face and how do they respond to those? Findings of a qualitative study conducted with female refugee students from Somalia indicate that students are to varying degrees active agents in the construction of their lives in a US urban school. Although they do experience religious discrimination, they find creative ways to respond to it and, despite the fact that learning English is an initial obstacle in their lives in their host country, they tend to be successful in acquiring the new language. These findings problematize the perception of students as passive victims of the structural forces that inform their lives. At the same time, they challenge educators to seek ways that could make schools positive contexts of reception of refugee and immigrant students. Although the study focuses on the experiences of refugee students with distinct cultural characteristics in the US, the issues raised ma...
Contractile response of norepinephrine is modulated by caspase-3 in adult rat ventricular myocytes isolated from septic rat heart.

Abstract Sepsis accounts for 50% of intensive care unit deaths due to cardiac dysfunction. The cellular mechanisms following norepinephrine (NE) during sepsis are undefined. Using a septic adult rat ventricular myocyte (ARVM) paradigm, we examined the molecular mechanism responsible for the blunted contractile response of NE. We tested the hypothesis that NE-induced increases in active caspase-3 contribute to sepsis-induced ARVM contractile dysfunction. Single ARVMs were isolated from hearts harvested from sham and septic male rats. The contractile properties and expression of caspase-3 cascade proteins were determined in ARVMs treated with NE with and without QVD-OPH, prazosin and atenolol to characterize the effect of NE on their mechanical properties. Septic ARVMs exhibited a significant decrease in peak shortening (PS) compared to sham ARVMs. The effect of NE on the PS of the sham ARVMs was more pronounced compared to the septic ARVMs, suggesting a blunted contractile response of NE. NE in the presence of QVD-OPH ameliorated the sepsis-induced decrease in PS at 18 h but not at 1 h, while the effect of NE on sepsis-induced contractile response remained unaffected at 18 h by prazosin and atenolol. An up-regulated expression of caspase-3 in NE-treated septic ARVMs was reversed by QVD-OPH, as seen by the increased number of septic ARVMs exhibiting caspase-3 fluorescence. Transfection of ARVMs using caspase-3 siRNA blocked sepsis-induced up-regulation of caspase-3 and increased PS following NE treatment. These data suggest that caspase-3 inhibition ameliorated sepsis-induced decreased ARVM contractility and blocked the blunted contractile response of NE.
A method to identify and restore a class of aliased signals

Abstract - When a continuous-time signal is sampled at a rate less than the Nyquist criterion, the signal is aliased. This distortion is usually irrecoverable. However, we show that for certain AM-FM signals, the distortion due to aliasing can be mitigated and an unaliased version of the signal can be recovered from its aliased samples. We present a method for determining whether or not a signal has potentially been distorted by aliasing, and an algorithm for recovering an unaliased version of the signal. The method is based on the manifestation of aliasing in the time-frequency plane, and estimating the instantaneous phase/frequency of the aliased signal.
Degenerate Two-Phase Incompressible Flow: I. Existence, Uniqueness and Regularity of a Weak Solution

Abstract This is the first paper of a series in which we analyze mathematical properties and develop numerical methods for a degenerate elliptic-parabolic partial differential system which describes the flow of two incompressible, immiscible fluids in porous media. In this paper we first show that this system possesses a weak solution under physically reasonable hypotheses on the data. Then we prove that this weak solution is unique. Finally, we establish regularity on the weak solution which is needed in the uniqueness proof. In particular, the Holder continuity of the saturation in space and time and the Lipschitz continuity of the pressure in space are obtained.
Team power3: Building the Market for a multisport organization

“I want this season to be even bigger than last year,” exclaimed Tom Zandt. “I have already planned more events-this is EXACTLY what we need to jumpstart the year and start producing money for the ...
Dynamic reduction of a CH4/air chemical mechanism appropriate for investigating vortex–flame interactions

This paper describes two methods, piecewise reusable implementation of solution mapping (PRISM) and dynamic steady-state approximation (DYSSA), in which chemistry is reduced dynamically to reduce the computational burden in combustion simulations. Each method utilizes the large range in species timescales to reduce the dimensionality to the number of species with slow timescales. The methods are applied within a framework that uses hypercubes to partition multidimensional chemical composition space, where each chemical species concentration, plus temperature, is represented by an axis in space. The dimensionality of the problem is reduced uniquely in each hypercube, but the dimensionality of chemical composition space is not reduced. The dimensionality reduction is dynamic and is different for different hypercubes, thereby escaping the restrictions of global methods in which reductions must be valid for all chemical mixtures. PRISM constructs polynomial equations in each hypercube, replacing the chemical kinetic ordinary differential equation (ODE) system with a set of quadratic polynomials with terms related to the number of species with slow timescales. Earlier versions of PRISM were applied to smaller chemical mechanisms and used all chemical species concentrations as terms. DYSSA is a dynamic treatment of the steady-state approximation and uses the fast–slow timescale separation to determine the set of steady-state species in each hypercube. A reduced number of chemical kinetic ODEs are integrated rather than the original full set. PRISM and DYSSA are evaluated for simulations of a pair of counterrotating vortices interacting with a premixed CH4/air laminar flame. DYSSA is sufficiently accurate for use in combustion simulations, and when relative errors are less than 1.0%, speedups on the order of 3 are observed. PRISM does not perform as well as DYSSA with respect to accuracy and efficiency. Although the polynomial evaluation that replaces the ODE solver is sufficiently fast, polynomials are not reused sufficiently to enable their construction cost to be recovered. © 2007 Wiley Periodicals, Inc. 39: 204–220, 2007
Regulation of the cholinergic gene locus

DNase I hypersensitive site mapping of the human cholinergic gene locus has been used to detect cholinergic specific potential regulatory sites. Analysis of mutant PC12 cell lines provides evidence that protein kinase A II is required and coordinately regulates basal expression of both the ChAT and VAChT genes.
Consistent and Variable Practice Conditions: Effects on Relative and Absolute Timing

The authors conducted the present experiments to resolve the discrepancy between studies in which relative-timing learning has been found to be enhanced by consistent practice conditions and contextual interference experiments in which relative-timing learning has been found to be enhanced more by random practice than by blocked practice. There were 40 participants in Experiment 1 and 48 in Experiment 2. The results of Experiment 1 extended previous findings: The learning of the relative-timing pattern was systematically enhanced by the degree to which the practice conditions promoted movement consistency (constant > blocked > serial > random). Experiment 2 provided evidence that the discrepancy between the relative-timing effects in the 2 groups of studies was a product of the way in which relative-timing goals and feedback were presented. When the feedback was presented as segment times, random practice resulted in generally more stable relative-timing patterns during acquisition than blocked practice did. Thus, in both experiments, the learning of the relative-timing pattern was enhanced by more stable relative-timing conditions during acquisition. Absolute-timing learning, as indexed by the transfer tests, was enhanced by serial or random practice as compared with constant or blocked practice, and was relatively unaffected by feedback conditions directed at the relative-timing pattern. In terms of motor programming theory, those findings are taken as additional evidence for the disassociation of memories supporting generalized motor program (GMP) performance, as indexed by relative timing, and parameter performance, as indexed by absolute timing.
SV40 antitumor sera that directly immunoprecipitate small-t-associated cellular proteins

Abstract Two cellular proteins, 56K and 32K, are immunoprecipitated in association with SV40 small-t antigen using antisera from animals bearing SV40-induced tumors. Antitumor sera have now been identified that immunoprecipitate these proteins directly from uninfected, as well as infected, cells.
Psychophysical and Social Ratings of Human Body Odor

Male graduate students provided body odor samples, rated the odors for unpleasantness using a standard magnitude estimation procedure, and attempted to identify their own odor. Male and female undergraduates rated the odors for unpleasant ness and evaluated odor donors using bipolar adjective scales. Results indicated a high degree of agreement among subjects' (graduates and undergraduates) rankings of odor unpleasantness. Correlations demonstrated that odor unpleasantness was generally associated with socially undesirable traits. Odor donors typically rated their own odor as more pleasant than did other raters. Odor donors demonstrated marginal ability to detect their own odor.
Treatment of a retarded adult's mannequin phobia through in vivo desensitization and shaping approach responses

Abstract The treatment of a 21-yr-old retarded male who exhibited a longstanding fear of mannequins is described. A program that shaped approach responses to mannequins of increasing size resulted in 100% approach responses to three different size mannequins during therapy sessions. One training session in a naturalistic setting (shopping mall) resulted in generalization that was maintained 6 months after treatment. A follow-up probe session conducted in the clinic 6 months following treatment showed that approach responses to the three mannequins used in training remained at 100%.
Hyperthermic effects on reticuloendothelial system particulate uptake.

Reticuloendothelial system (RES) particulate uptake (PU) of vascular debris influences survival from extreme hyperthermia. Little is known of the effect of extreme hyperthermia, unrelated to fever, on RES PU shortly after reaching a maximum core temperature (Tc). Relative to normothermic rats (Tc=38.0°C), rats at Tc=42.6°C had significantly higher, while Tc=42.0°C rats had significantly lower total RES tissue (lung, liver, spleen) PU of fluorescent microspheres (1 μ), when compared to rats at Tc=42.6 or 38.0°C. These findings suggest at Tc=42.6°C, rats were not actively thermoregulating. As such, more blood remained in the core than in the periphery, which resulted in greater core RES tissue PU. In contrast, to reduce or control core heat, rats at Tc=42.0° or 38.0°C directed more blood to the periphery, which reduced core RES tissue PU. Blood flow patterns as directed by the state or degree of active thermoregulation is likely an influence of hyperthermia on RES PU.
Selective Adsorption for Removing Sulfur from Jet Fuel over Zeolite-Based Adsorbents

Adsorbents based on transition metal ion-exchanged Y zeolites (with Cu, Ni, Zn, Pd, and Ce ions) were synthesized and evaluated for the adsorptive desulfurization of a model jet fuel (MJF) and a real jet fuel (JP-8). Among the adsorbents tested, Ce-exchanged Y zeolites exhibited better adsorption capacity of about 10 mg of sulfur/g of adsorbent at 80 °C with a MJF containing 510 ppmw sulfur. The same adsorbent exhibited a sulfur adsorption capacity of about 4.5 mg/g for the real JP-8 jet fuel containing about 750 ppmw sulfur. Desulfurization of MJF under flow conditions at 80 °C showed a breakthrough capacity of about 2.3 mg/g of adsorbent. Ce-exchanged zeolites exhibited higher selectivity for sulfur compounds as compared to the selectivity of aromatics, for which a comparative study indicated that the sulfur compounds are adsorbed over Ce-exchanged Y zeolites via direct sulfur−adsorbent (S−M) interaction rather than via π-complexation. While the selectivity for 2-methyl benzothiophene (2-MBT) was higher...
N-hydroxypyridine-2-thione carbamates. v. syntheses of alkaloid skeletons by aminium cation radical cyclizations

Abstract The title radical precursors (PTOC carbamates) were employed as sources of a variety of 5,6-unsaturated aminium cation radicals. 5-Exo radical cyclization followed by trapping by t-BuSH or the PTOC carbamate gave a variety of aklaloid skeletons, typically in good to excellent yields, including pyrrolidines, perhydroindoles, pyrrolizidines, tropanes, 9-azabicyclo[4.2.1]nonanes, 6-azabicyclo [3.2.1]octanes. 6-Exo and 7-endo cyclizations competed in a 6,7-unsaturated system
What can be done to help the low-ability student?

After examining some experiences with very low-level adult language learners in the San Francisco Adult School, methods of helping low-ability students will be suggested. Before trying to help a low-ability student, however, it is necessary to find out why the student has a low ability. Is the student just beginning, or has the student been studying for a long time without apparently accomplishing much? Three types of low ability students are considered: (1) the beginner, (2) the low-ability student at other levels, and (3) the static student.
Bacteriophage Mu integration: On the mechanism of Mu-induced mutations☆

Abstract Infection of Escherichia coli with bacteriophage Mu leads to an increase in the mutation frequency in a wide variety of genes. Taylor (1963) has proposed that these mutations are caused by the integration of the Mu prophage into the gene. The experiments reported in this paper show that the Mu prophage is genetically located at or near the site of the Mu-induced mutation in accord with Taylor's proposal. A Mu-induced chl-D mutation between the λ prophage attachment site and the gal operon prevents λ from transducing gal genes. It is possible to isolate λ-transducing particles from lysates of this strain which carry portions of the Mu prophage. These particles are packaged in λ capsids. Further aspects of Mu mutagenesis are discussed.
Library materials from Latin America and the Caribbean: Problems and approaches in acquisitions

Abstract The Latin American countries differ one from the other as do their publishing industries and book trades. A factor present in all of them affecting the acquisition of library materials is the lack of bibliographic control. To secure current material from the area, librarians have resorted to standing order plans. Finding good local bookdealers and preparing and carefully monitoring accurate profiles are basic elements for the efficient functioning of the plan. Postal service peculiarities and fluctuations in the foreign exchange along with political instability and censorship are external factors which also affect the process. Governmental publications present their own problems different from the commercial ones. The nations of the Caribbean basin have even greater differences among themselves than the continental countries. Smaller publishing houses and editions compound the difficulties of the acquisitions operation. Setting up standing order plans has also been the most helpful means found by librarians. Cuba, due to its unusual relations with the U.S. is a unique case. Overcoming these difficulties make the job of the acquisitions librarians of Latin American and Caribbean materials extremely fascinating.
Cedric Robinson’s anthropology of Marxism

In meditating on the significance of Robinson’s body of work, particularly An Anthropology of Marxism, Gordon discusses the profound originality of his enterprise. At its heart lies a rigorous deconstruction of the terms of western civilisation which exposes the philosophical and historical compromises made by Marxism and Liberalism with the tenets of bourgeois rationality. The blindness within Marxian thought to socialist and radical traditions outside its purview, documented and analysed by Robinson, is his starting point for a broader and more generous historical materialism that recuperates a fuller range of human experience.
Group testing in heterogeneous populations by using halving algorithms.

Group (pooled) testing is often used to reduce the total number of tests that are needed to screen a large number of individuals for an infectious disease or some other binary characteristic. Traditionally, research in group testing has assumed that each individual is independent with the same risk of positivity. More recently, there has been a growing set of literature generalizing previous work in group testing to include heterogeneous populations so that each individual has a different risk of positivity. We investigate the effect of acknowledging population heterogeneity on a commonly used group testing procedure which is known as ‘halving’. For this procedure, positive groups are successively split into two equal-sized halves until all groups test negatively or until individual testing occurs. We show that heterogeneity does not affect the mean number of tests when individuals are randomly assigned to subgroups. However, when individuals are assigned to subgroups on the basis of their risk probabilities, we show that our proposed procedures reduce the number of tests by taking advantage of the heterogeneity. This is illustrated by using chlamydia and gonorrhoea screening data from the state of Nebraska.
Thermal Conduction and Particle Transport in Strong Magnetohydrodynamic Turbulence, with Application to Galaxy Cluster Plasmas

Galaxy clusters possess turbulent magnetic fields with a dominant scale length lB ' 1 10 kpc. In the static magnetic field approximation, the thermal conductivityT for heat transport over distances 3 lB in clusters is '� SlB/LS(� e), whereS is the Spitzer thermal conductivity for a nonmagnetized plasma, the length LS(r0 )i s a characteristic distance that a pair of field lines separated by a distance r0 < lB at one location must be followed before they separate by a distance lB ,a nde is the electron gyroradius. We introduce an analytic Fokker-Planck model and a numerical Monte Carlo model of field-line separation in strong magnetohydrodynamic (MHD) turbulence to calculate LS(r0). We also determine LS(r0) using direct numerical simulations of MHD turbulence with zero mean magnetic field. All three approaches, like earlier models, predict that LS asymptotes to a value of order several lB as r0 is decreased toward ld in the large-lB/ld limit, where ld is the dissipation scale, which is taken to be the proton gyroradius. When the turbulence parameters used in the Fokker-Planck and Monte Carlo models are evaluated using direct numerical simulations, the Fokker-Planck model yields LSð� e Þ' 4:5lB and the Monte Carlo model yields LSð� e Þ' 6:5lB in the large-lB/ld limit. Extrapolating from our direct numerical simulations to the large-lB/ld limit, we find that LSð� e Þ' 5lB 10lB, implying thatT ' 0:1� S 0:2� S in galaxy clusters in the static field approximation. We also discuss the phenomenology of thermal conduction and particle diffusion in the presence of time-varying turbulent magnetic fields. Under the questionable assumption that turbulent re- sistivity completely reconnects field lines on the timescale lB/u ,w hereu is the rms turbulent velocity, we find that � T is enhanced by a moderate amount relative to the static field estimate for typical cluster conditions. Subject headings: galaxies: clusters: general — intergalactic medium — MHD — plasmas — turbulence
Measuring Influence of Accessibility on Accident Severity with Structural Equation Modeling

Structural equation modeling (SEM) is a confirmatory, multivariate technique used to examine causal relationships between variables. Related to path analysis with a goal of selecting a model that best explains underlying relationships between variables, SEM is a useful tool for traffic safety research. This study examined the severity of crashes in terms of factors commonly attributed to accidents. These factors included human, vehicle, and roadway factors, along with accessibility measures that were considered relevant in previous studies. In this study, SEM was used to test an a priori model of crash severity. The analysis was carried out in a two-step process. The measurement model was first tested with a confirmatory factor analysis. After the validity of the measurement model was established, a four-latent-factor structural model was run. With an acceptable model fit, the magnitude of standardized path coefficients from the exogenous latent variables provided a means to assess the relative importance...
Electrical Wind Force–Driven and Dislocation-Templated Amorphization in Phase-Change Nanowires

Phase-change materials that can readily switch between crystalline and amorphous states are increasingly finding use in nonvolatile memory devices (see the Perspective by [ Hewak and Gholipour ][1]). Using high-resolution transmission electron microscopy, Nam et al. (p. [1561][2]) show that for Ge2Sb2Te5, the application of an electric field drives crystal dislocations in one direction, leading to their accumulation and eventual jamming, which causes the phase transition. Loke et al. (p. [1566][3]) found that by applying a constant low voltage to Ge2Sb2Te5, they could accelerate its phase-switching speeds, without harming the long-term stability of the switched state. [1]: /lookup/volpage/336/1515?iss=6088 [2]: /lookup/doi/10.1126/science.1220119 [3]: /lookup/doi/10.1126/science.1221561
ADAPTIVE TECHNIQUE FOR FLUORESCENCE ENHANCED OPTICAL TOMOGRAPHY USING TETRAHEDRAL DUAL-MESH

Fully adaptive fluorescence enhanced optical tomography using tetrahedral dual-mesh has been developed. The proposed method has been enabled by the efficient intersection algorithm developed for 8-sub-tetrahedron subdivision scheme. Using the synthetic data, we demonstrate that the tetrahedron-based adaptive dual-mesh scheme can provide at reasonable cost, high resolution imaging of small fluorescent targets simulated in the breast-shaped phantoms
Why Do Some Civil Wars Last So Much Longer than Others

Five factors are shown to be strongly related to civil war duration. Civil wars emerging from coups or revolutions tend to be short. Civil wars in Eastern Europe and the former Soviet Union have al...
Gas diffusion in random‐fiber substrates

A Monte Carlo (MC) technique involving explicit calculation of molecular trajectories in fibrous media is used to obtain effective transport coefficients in the Knudsen regime of gas diffusion. A fully penetrable cylinders (FPC) model is used to represent a fibrous substrate during the course of densification, as in composite fabrication processes such as chemical vapor infiltration (CVI). The calculated Knudsen permeabilities are in excellent agreement with available data. Accessible porosities are computed as a function of total porosity and are shown to depend on the fiber number density. The nonfiber phase is shown to percolate at ϕ ≈ 0.095, but the threshold is sensitive to the boundary conditions employed.
Identifying White-Matter Fiber Bundles in DTI Data Using an Automated Proximity-Based Fiber-Clustering Method

We present a method for clustering diffusion tensor imaging (DTI) integral curves into anatomically plausible bundles. An expert rater evaluated the anatomical accuracy of the bundles. We also evaluated the method by applying an experimental cross-subject labeling method to the clustering results. We first employ a sampling and culling strategy for generating DTI integral curves and then constrain the curves so that they terminate in gray matter. We then employ a clustering method based on a proximity measure calculated between every pair of curves. We interactively selected a proximity threshold to achieve visually optimal clustering in models from four DTI datasets. An expert rater then assigned a confidence rating about bundle presence and accuracy for each of 12 target fiber bundles of varying calibers and type in each dataset. We then created a fiber bundle template to cluster and label the fiber bundles automatically in new datasets. According to expert evaluation, the automated proximity-based clustering and labeling algorithm consistently yields anatomically plausible fiber bundles on large and coherent clusters. This work has the potential to provide an automatic and robust way to find and study neural fiber bundles within DTI.
The Biology of Rose Rosette Disease: A Mite‐associated Disease of Uncertain Aetiology

Spread of rose rosette disease was best described by a logistic population growth model. In Iowa, peak susceptibility to graft transmission of the disease in the field occurred from May 27 through July 10. Populations of the eriophyid mite vector were low until mid-July and reached peak levels at the end of August. Host range was limited to multiflora rose and hybrid ornamental roses. No evidence was obtained for seed- or soil-transmission of the aetiologic agent and no symptom remission was obtained with either heat therapy or tetracycline treatment. A significant decrease in stored starch corresponded with a major decrease in sucrose and increases in fructose and glucose in infected tissue. Because of its limited host range, the agent may have potential for biocontrol of multiflora rose.
Biomedical publications on Ebola and the 2014 outbreak

In this research note we examine the biomedical publication output about Ebola in 2014. We show that the volume of publications has dramatically increased in the past year. The rise reflects an impressive growth starting in the month of August, concomitant with or following the surge in infections, deaths and coverage in news and social media. Though non-research articles have been the major contributors to this growth, there has been a substantial increase in original research articles too, including many papers of basic science. The United States has been the country with the highest number of research articles, followed by Canada and the United Kingdom. We present a comprehensive set of charts and facts that, by describing the volumes and nature of publications in 2014, show how the scientific community has responded to the Ebola outbreak and how it might respond to future similar global threats and media events. This information will assist scholars and policymakers in their efforts to improve scientific research policies with the goal of maximizing both public health and knowledge advancement.
A batch fabricated biomimetic dry adhesive

The fine hair adhesive system found in nature is capable of reversibly adhering to just about an ys urface. This dry adhesive, best demonstrated in the pad of the gecko, makes use of a multilevel conformal structure to greatly increase inelastic surface contact, enhancing short range interactions and producing significant amounts of attractiv ef orces. Recent work has attempted to reproduce and test the terminal submicrometre 'hairs' of the system. Here we report the first batch fabricated multi-scale conformal system to mimic nature's dry adhesive. The approach makes use of massively parallel MEMS processing technology to produce 20-150 µm platforms, supported by single slender pillars, and coated with ∼2 µ ml ong, ∼200 nm diameter, organic looking polymer nanorods, or 'organorods'. To characterize the structures a new mesoscale nanoindenter adhesion test technique has been developed. Experiments indicate significantly improved adhesion with the multiscale system. Additional processing caused a hydrophilic to hydrophobic transformation of the surface and testing indicated further improvement in adhesion. (Some figures in this article are in colour only in the electronic version)
Myocardial uptake of (99m)Tc-N-NOET and (201)Tl during dobutamine infusion. Comparison with adenosine stress.

Background—The myocardial uptake of 99mTc-sestamibi is attenuated by dobutamine stress, resulting in underestimation of ischemia. N-Ethyl-N-ethoxy-dithiocarbamato-N-99mTc (99mTc-N-NOET) is a new 99mTc-labeled perfusion agent that is highly extracted by the myocardium by a mechanism different from that defined for 99mTc-sestamibi. We therefore hypothesized that 99mTc-N-NOET uptake would not be attenuated by dobutamine and that 99mTc-N-NOET uptake would be comparable to 201Tl uptake during dobutamine stress. Methods and Results—In 28 open-chest dogs, after placement of a stenosis in the left anterior descending coronary artery that reduced flow reserve by >50%, adenosine (300 μg · kg−1 · min−1; n=15) or dobutamine (2.5 to 30 μg · kg−1 · min−1; n=13) was infused. During adenosine stress, the stenotic-to-normal activity ratio for 99mTc-N-NOET was 0.55±0.05. The stenotic-to-normal flow ratio was 0.33±0.04 at the time of 99mTc-N-NOET injection. During dobutamine stress, the stenotic-to-normal 99mTc-N-NOET activ...
Asynchronous distributed averaging using double linear iterations

The distributed averaging problem is to devise a protocol which will enable the members of a group of n > 1 agents to asymptotically determine in a decentralized manner, the average of the initial values of their scalar agreement variables. A typical averaging protocol can be modeled by a linear iterative equation whose update matrices are doubly stochastic. Building on the ideas proposed in [1] and [2], this paper discusses an alternative approach to distributed averaging which is modeled by two simultaneously iterated linear iterative equations whose update matrices are left stochastic rather than doubly stochastic. We call such models, double linear iterations. The aim of this paper is to propose and analyze two different asynchronous double linear iteration protocols. For each protocol, each agent independently updates its variables at times determined by its own clock. It is not assumed that the agents' clocks are synchronized or that the “event times” at which any one agent updates its variables are evenly spaced. Nor is it assumed that the communication between agents is bidirectional. By appealing to the concept of “analytic synchronization”, it is shown that both the two protocols are guaranteed to solve the asynchronous distributed averaging problem under appropriate assumptions for both fixed and time-varying directed neighbor graphs.
Surgical management of posterior fossa mass lesions.

Indications Patients with mass effect on computed tomographic (CT) scan or with neurological dysfunction or deterioration referable to the lesion should undergo operative intervention. Mass effect on CT scan is defined as distortion, dislocation, or obliteration of the fourth ventricle; compression or loss of visualization of the basal cisterns, or the presence of obstructive hydrocephalus. Patients with lesions and no significant mass effect on CT scan and without signs of neurological dysfunction may be managed by close observation and serial imaging. Timing In patients with indications for surgical intervention, evacuation should be performed as soon as possible because these patients can deteriorate rapidly, thus, worsening their prognosis. Methods Suboccipital craniectomy is the predominant method reported for evacuation of posterior fossa mass lesions, and is therefore recommended.