cssi/SciSciGPT-SciSciNet huggingface dataset:
An azide-diene cycloaddition approach to indolizidine alkaloids. An enantioselective synthesis of 67-diepicastanospermine

Abstract A short, enantioselective synthesis of 6,7-di epi castanospermine ( 4 ) has been achieved by an intramolecular azide-diene 1,3-dipolar cycloaddition, followed by ring-opening of the vinylaziridine 6 and subsequent dihydroxylation.
Collisionless magnetic reconnection in an asymmetric current sheet

[1] The process of collisionless magnetic reconnection in an ion-scale current sheet containing strong gradients in the density and magnetic field strength across the layer is investigated using two-dimensional particle-in-cell simulations. Such a current sheet configuration contains a strong normal polarization electric field on the high field/low density (magnetospheric) side of the layer. In initial-value simulations for such an asymmetric sheet, the reconnection rate and saturation level are found to be smaller by factors of 2–3 compared with a similar-scale symmetric current sheet. These rates are probably too small to explain observations at the dayside magnetopause. The addition of an external-driving electric field increases the reconnection rate substantially. This driven reconnection configuration is characterized by a nearly parallel inflow of electrons along the magnetosheath separatrices as the electrons attempt to flow from the high density side to the low density side of the layer, a strong outward flow of Poynting flux along the magnetospheric separatrices associated with the normal electric field and out-of-plane magnetic field, and a strong ion outflow jet. The outflow region on the magnetospheric side also exhibits a patchy parallel electric field structure and parallel electron velocity distributions with a counterstreaming feature. The addition of a moderate uniform magnetic guide field component (shear angle ≳110°) has no appreciable effect on the reconnection rate but does produce a drift of the X line in the direction of the electron diamagnetic drift at a small fraction of the magnetosheath Alfven speed.
SP0007 Chronic Gout, Chronic Treatment

Gout is a chronic metabolic and inflammatory disease whose sine qua non is hyperuricemia. The acute attacks seen in gout are merely the “tip of the iceberg” and represent the effector response to a set of conditions that lead to monosodium urate precipitation and deposition. Moreover, the chronic state of gout is accompanied by co-morbidities that are not resolved when the inflammatory attacks are treated. In consequence, gout must be thought of as a chronic rather than an intermittent condition, and gout treatment should be considered a long-term, and possibly lifelong endeavor. In this brief talk we will consider the chronic nature of gout, as well as current recommendations for chronic gout treatment (diet, lifestyle, and anti-inflammatory and urate-lowering pharmacotherapy), and for assessment of treatment outcomes, including the potential use of imaging. We will also discuss the possibility that good gout treatment initially results in easier gout treatment later on (“debulking”, or Perez-Ruiz’s “dirty dish” hypothesis), and the question of whether “tight control” of gout may have benefit not only for gout, but for gout’s co-morbidities as well. Disclosure of Interest M. Pillinger Grant/research support from: Savient Pharmaceuticals, Takeda Pharmaceuticals
Biological Effectiveness of Alpha Particles as a Function of Ion Concentration Produced in their Paths

It is an old and very generally accepted view ( e.g. , Aschkinass and Caspari, 1901; Redfield and Bright, 1924; Packard, 1931) that the biological effects of x-rays, cathode rays, and radiations from radio-active substances are associated in some way with the ionization they produce in the living material. However, there is as yet no general agreement concerning the exact nature of the part played by the ions.2 In particular, there is still wide divergence of opinion concerning the existence of any effect due to distribution of the ions in the irradiated tissue. This question is especially controversial among workers with x-rays and gamma rays, for the much discussed factor of wavelength, if existent, must operate through differences in distribution of ions.3
A simple technique for enhancing the sensitivity of a commercial solid‐ phase radioimmunoassay for hepatitis B surface antigen (HBsAg)

A simple procedural modification of a commercial solid-phase radioimmunoassay technique resulted in increased sensitivity for detecting HBsAg. The main feature of the modification consisted of agitation of the sample and solid-phase antibody during the first incubation. This was achieved by dispensing the bead and sample into a vial and rotating the vial gently during the incubation period. The modified technique resulted in the detection of HBsAg in the range of 1.0 to 1.2 ng/ml (ay subtype) and 0.16 to 0.38 ng/ml (ad subtype). Samples that were reactive by the rotation technique could be shown to be specific by using an immunological neutralization test. Plasma as well as serum could be tested by the rotation technique and gave comparable results when samples were incubated at 45 C or at room temperature. Three (1.3%) of 227 donor samples containing anti-HBc as the sole hepatitis B marker were specifically reactive for HBsAg by the modified procedure, although no sample was reactive by the standard technique.
Valence-Shell Calculations on Polyatomic Molecules III. The Calculation of Dipole Moments and the Structure of Sydnone*

Calculations using the CNDO/2, the Extended Huckel (EH) method, and an iterative Extended Huckel (IEH) method are reported for HF, H2O, NH3, CO, H2CO, HCONH2, HCOOH, HCOF and sydnone. For the IEH method, it is shown that if the dipole moment is calculated by including the atomic dipole moment and the overlap moment (homopolar dipole) as well as the term from the Mulliken populations, then, except for carbon monoxide, the IEH method gives results in good agreement with experiment. The non-iterative EH method predicts dipole moments that are much too high. For molecules with dipole moments smaller than 3 Debyes, the IEH and CNDO/2 methods give similar results, but for molecules with higher dipole moments (formamide and sydnone), the CNDO/2 method gives better agreement with experiment. Comparison of the calculations on sydnone with those on other carbonyl compounds suggests that sydnone is best represented as a resonance stabilized azo-methine imine rather than as a “meso-ionic” or betaine type compound.
Serine biosynthesis in Tetrahymena pyriformis S.

Abstract 1. 1. Glycine transhydroxymethylase and threonine aldolase function in the formation of serine in Tetrahymena pyriformis S. 2. 2. Both the phosphorylated and non-phosphorylated pathways of serine biosynthesis from 3-phosphoglycerate are also operative. 3. 3. Tricarboxylic acid cycle intermediates also serve as serine precursors in this organism. 4. 4. Pyruvate, short chain fatty acids, and at low concentrations, α-ketoglutarate, appear to serve as energy sources for serine incorporation.
Endovascular Approach to Treating Common Iliac Artery Aneurysm with Contralateral Aorto-uni-iliac Endograft and a Femoral-femoral Bypass

Iliac artery aneurysms (IAA) are often found coexisting with abdominal aortic aneurysms. There is significant risk of associated morbidity and mortality when not treated appropriately. In these two case reports, the authors describe a minimally invasive endovascular approach to treat IAA by placing an aorto-uni-iliac endograft through the contralateral side of the common iliac aneurysm.
Pathophysiology of congenital diaphragmatic hernia: I. Renal enlargement suggests feedback modulation by pulmonary derived renotropins--a unifying hypothesis to explain pulmonary hypoplasia, polyhydramnios, and renal enlargement in the fetus/newborn with congenital diaphragmatic hernia.

Survival of newborns with congenital diaphragmatic hernia (CDH) is largely dependent on the severity of pulmonary hypoplasia (PH) present at birth. Intrathoracic compression by the herniated abdominal viscera is thought to be the primary factor involved in the pathogenesis of the PH in CDH. Humoral and/or amniotic pulmonary growth factors (PGF) have been hypothesized to play a role in normal fetal pulmonary development and may be involved in the pathogenesis of CDH as well. The hypothesis of this paper is that growth of the fetal lung is stimulated by a PGF produced by the kidneys, which is modulated by a feedback signal from the lungs, a pulmonary derived renotropin (PDR). In the fetus with CDH, the lungs may be unable to respond to PGF due to compression by the herniated abdominal viscera. Theoretically, PH associated with CDH would maximally stimulate this feedback loop to release more PDR, resulting in continual stimulation of the kidneys and renal enlargement. If such a scheme plays a role in the in utero pathophysiology of CDH, then newborns with CDH should have enlarged kidneys. To investigate this hypothesis, we reviewed 30 autopsy cases of newborns with CDH and analyzed their kidney weights versus body weights, using historical data as control. Kidney weights in CDH cases were greater than the control population in 77% of the cases; 57% of kidney weights were more than one standard deviation above control values. Adjusted group mean kidney weights were 29.8 g (+/- 1.0 SE) in CDH cases and 25.9 g (+/- 1.5 SE) in the control population (P less than .04). These data support our hypothesis and demonstrate that in newborns with CDH and morphologically normal kidneys, there is significant renal enlargement associated with CDH. The presumed mechanism of this renal enlargement, as well as its relationship to normal and aberrant pulmonary growth and regulation are discussed. If such a selective PGF exists, its therapeutic implications for fetuses and newborns with PH are considerable.
How annual reports communicate a customer orientation

Abstract This article deals with the frequency with which CEOs express their companies commitment to customers in the president's letter section in their companies' annual reports. It focuses on manufacturing companies operating in industrial markets. For the purpose of the research, a typology of references, including customer commitment, made to “customer(s)” in presidents' letters is developed. The construct of customer commitment is based on a search of relevant literature. Results show that only a small percentage of companies use the president's letter in their annual reports to communicate commitment to customers. In fact, some president's letters fail even to mention the word “customer(s).” The authors conclude there is an overlooked opportunity for companies to use the president's letter to communicate customer commitment. The issue of companies who talk about customer commitment, but who do not perform accordingly in the marketplace, is also addressed.
Radiation-Field Coupling In Optical Waveguide Structures With Closely Spaced Abrupt Bends And Branches

AbstractOptical waveguide structures with symmetric branches preceded by abrupt bends werestudied. Measured power -splitting ratios range from U to 6 dB and oscillate with the bend -brancn separation. The power splitting also depends on the mode effective index, which isaffected by the polarization, wavelength and waveguide fabrication parameters. Deviceimplications are also discussed.IntroductionOptical waveyuide structures containing successive bends and branches are useful fordistributing optical power in multi- device integrated optical circuits. Space limitationsmay require that the bends and branches in complex structures be spaced closely toyetner.We report here the first experimental and theoretical study of structures with closelyspaced bends and branches. Single -mode Ti:LiNb03 channel- waveguide structures consisting ofa symmetric Y- branch preceded by an abrupt bend were fabricated and tested. Measured power -splitting ratios exhibit a strong oscillatory dependence on the length of the waveyuidesegment connecting the bend and the branch. The splitting ratios range from 0 to t6 dB forconnecting -segment lengths between 100 and 800 um. This variation becomes less pronouncedat longer connecting- segment lengths. Results of this study can be used to design multiple -branching structures.1Earlier studies of related structures with closely spaced abrupt bends have shown thatthe transmission of such structures varies in a damped oscillatory manner with the length ofthe connecting seyment.2
The long range intermolecular potential of H2-H2

(1972). The long range intermolecular potential of H2-H2. Molecular Physics: Vol. 24, No. 1, pp. 235-239.
Thermal degradation products derived from the smoke of Salvia divinorum leaves

Smoking of Salvia divinorum leaves is the most common method for its psychotropic effects. Eleven thermal degradation products, including a new neoclerodane diterpene derivative, were isolated from the smoke of S. divinorum leaves, and their structures were identified by spectroscopic methods. The isolated compounds were evaluated for their binding affinities at the opioid receptors, and salvinorin A is still the most potent kappa opioid receptor agonist.
The Effect of Otitis Media With Effusion on the Masking-Level Difference and the Auditory Brainstem Response

This study investigated the masking-level difference (MLD) and auditory brainstem response (ABR) in a group of children with a history of otitis media with effusion (OME) and a control group of chi...
Interleukin-7 Receptor Signaling Network: An Integrated Systems Perspective

Interleukin-7 (IL-7) is an essential cytokine for the development and homeostatic maintenance of T and B lymphocytes. Binding of IL-7 to its cognate receptor, the IL-7 receptor (IL-7R), activates multiple pathways that regulate lymphocyte survival, glucose uptake, proliferation and differentiation. There has been much interest in understanding how IL-7 receptor signaling is modulated at multiple interconnected network levels. This review examines how the strength of the signal through the IL-7 receptor is modulated in T and B cells, including the use of shared receptor components, signaling crosstalk, shared interaction domains, feedback loops, integrated gene regulation, multimerization and ligand competition. We discuss how these network control mechanisms could integrate to govern the properties of IL-7R signaling in lymphocytes in health and disease. Analysis of IL-7 receptor signaling at a network level in a systematic manner will allow for a comprehensive approach to understanding the impact of multiple signaling pathways on lymphocyte biology.
Coral reef environmental science: truth versus the Cassandra syndrome

In 1970, coral reef science was warned that the crown-of-thorns starfish, Acanthaster planci, might cause the extinction of scleractinian corals in the Pacific Ocean. Now, 20 years later we can fortunately say that this alarm was almost certainly too severe. Many reefs were devastated by the starfish, but none are extinct, none have disappeared and many are in various stages of recovery. But now in the 1990's a new alarm is being sounded. This time the concern is over widespread destruction of coral reefs by elevated surface temperatures. Once again a few scientists have issued a dire warning that these events may represent a harbinger of ocean warming caused by the Greenhouse Effect. Has not Acanthaster taught coral reef science a lesson? The debate is far from over but this time the mood in general is not one of over-reaction. This time the Cassandras will be tested by the truth of careful experimentation, long-term monitoring and objective interpretation. Coral reef science appears to have come of age.
Entrepreneurial actions and optimistic overconfidence: The role of motivated reasoning in new product introductions

Abstract Optimistic overconfidence (OO), that is, being certain of success only to end up disappointed, represents a potentially catastrophic error. However, few studies have identified which entrepreneurial actions are associated with it. To explore this issue, we examined 55 small companies and found that OO of product success was positively related to introducing products that required more resources and were more pioneering. Furthermore, satisfaction with company performance had a curvilinear (U-shaped) relationship with overconfidence. Both high and low levels of satisfaction were associated with greater OO in product introductions. In addition, the bias was positively correlated with entering hostile environments; that is, environments that are characterized by intense competition that threatens a firm and its introductions. Contrary to expectations, however, OO was negatively associated with environmental dynamism; defined as environments that embody frequent and large changes. The research also compared general knowledge overconfidence to OO, concluding that each represents a distinct bias with distinct effects.
$ \alpha $-cut-complete Boolean algebras

Let A be a Boolean algebra, and \( \alpha \) an infinite cardinal number or the symbol \( \infty \). An \( \alpha \)-cut in A is an ordered pair (F,H) of subsets of A, each of power \( \le \alpha \), with \( F \le H \) elementwise, with 0 as the meet of differences \( h - f (h \in H, f \in F) \). A is called \( \alpha \)-cut-complete if for each \( \alpha \)-cut (F,H) there is \( a \in A \) with \( F \le a \le H \) elementwise. We describe the simply-constructed \( \alpha \)-cut-completion \( A^\alpha \), show that \( \alpha \)-cut-completeness solves a natural \( \alpha \)-injectivity problem, determine when \( A^\alpha \) is the \( \alpha \)-completion, or the completion, and interpret most of that topologically in Stone spaces. Oddly, these considerations seem novel in Boolean algebras, while for lattice-ordered groups and vector lattices, and dually for topological spaces, the analogous theory, especially for \( \alpha = \omega_1 \), has received considerable study.
A strain recording model: Analysis of transverse osteotomy fixation in small bones

Many current experimental testing procedures are cumbersome when applied to osteotomies of small bones and are complicated by the need for in-depth analyses of data derived from various specimens tested to failure. This strain recording model minimizes these factors. Various forms of internal fixation may be serially tested on the same specimen with this system because constructs are not tested to failure but rather within the elastic range of each specimen. Sophistication in the form of strain recorded as a function of time allows the comparison of various fixation techniques. Fixation techniques applied to a transverse osteotomy and subjected to controlled flexion loading in a single plane have been evaluated. The study demonstrates the superiority of tension bands (wires) placed through holes immediately subjacent to the tension cortex in comparison with wires that fix the components through holes in the neutral longitudinal axis. In addition, for any given time, the strain generated by a single-looped tension band (wire) is greater than that of a figure-of-eight tension band (wire). Both types of tension bands afford superior stability experimentally, compared to conventional crossed Kirschner wire fixation of transverse osteotomies.
In from the Cold: Prospects for Conversion of the Defense Industrial Base

At the end of the Cold War, the manufacturing operations involved in making military equipment and commercial goods are commonly believed to intersect hardly at all. Our analyses of 1991 survey data from a large sample of establishments in the machining-intensive durable goods sector show that there are few technical and competitive conditions separating the defense and commercial industrial spheres. Commercial-military integration of production is now the normal practice among the majority of defense contractors in this sector. Moreover, we find little difference between defense and commercial producers in the competitive conditions they face or in the diversity of their customers. However, defense contractors have an advantage over their strictly commercial counterparts because of their greater use of productivity-enhancing technologies.
A sequential solution procedure to stochastic capital budgeting models

Abstract A sequential solution procedure to stochastic capital budgeting models is described. The procedure is based on multiple stages of experimental optimization, when the results from a given stage may determine part of the final portfolio of investments to be funded. By establishing criteria for reducing the problem size, while proceeding from one stage to another, one can have some control on the total budget for computer time needed.
Getting one's own way: An investigation of influence attempts by marketers on nonmarketing members of the firm

Abstract This study examines the relationship between a marketer's use of various attempts to influence a nonmarketing coworker and the coworker's perception of marketing as a credible source of high-quality communications. Research on this topic is important because both the distribution of market intelligence to other firm members and the organization's response to that intelligence depend on marketing's interactions with members of other organizational functions. Results provide general support for the effect of organizational environment and interfunctional dynamics antecedents on marketing's use of various influence strategies and on the outcomes of using those strategies. Implications and future research opportunities are discussed.
The effect of homogenization treatment and hot isostatic pressing on microporosity in cast steel

The effect of high temperature homogenization treatment and hot isostatic pressing on microporosity in unidirectionally solidified AISI 4330 low alloy steel ingots was investigated. The volume fraction and size distribution of micropores in the as-cast, homogenized, and hot isostatically pressed conditions were determined using X-ray microradiography and optical metallography. The vol pct of spherical, nonspherical and total microporosity increased with distance from the chill in a linear fashion in both the as-cast and the homogenized conditions. The vol pct of microporosity decreased with increasing homogenization time. Nonspherical micropores gradually spheroidized during the treatment. Elimination of microporosity was substantially accelerated by carrying out homogenization under high isostatic pressure. Measured vol pct microporosity at 3 cm from the chill before and after vacuum homogenization at 1315°C for 30 h were 2 × 10−2 and 1 × 10−2, respectively. All observable microporosity was eliminated by hot isostatic pressing for 1 h at 1260 and 1O38°C with corresponding pressures of 29,000 and 27,000 psi, respectively. It is proposed that vacancy diffusion to grain boundaries is the rate controlling mechanism.
Factors Controlling Mercury and Methylmercury Concentrations in Largemouth Bass (Micropterus salmoides) and Other Fish from Maryland Reservoirs

The concentration of mercury (Hg) and methylmercury (MeHg) was determined for largemouth bass (Micropterus salmoides), bluegill (Lepomis macrochirus) and black crappie (Pomoxis nigromaculatus) from Maryland reservoirs. Overall, there was a large difference in normalized bass MeHg concentration (for fish of ∼370 mm) between the reservoirs, ranging from <100 ng g−1 to almost 800 ng g−1. Furthermore, the relationship between fish weight and MeHg concentration varied substantially between lakes, and showed no geographical relationship. The concentration of Hg, MeHg and ancillary parameters were determined in the water and correlations were sought between the normalized concentration of MeHg in bass and both physical and chemical parameters of the reservoirs, as well as the concentration of MeHg in the prey of the largemouth bass. Bass MeHg concentration correlated with dissolved MeHg and dissolved organic carbon, but not with other chemical parameters. There was no relationship to physical characteristics that varied over orders of magnitude for these reservoirs. Dissolved MeHg did not correlate with any chemical or physical attributes. Overall, this study suggests that water column MeHg is a good predictor of fish concentration but that the water column MeHg cannot be predicted based on usually measured chemical and physical characteristics of fresh water bodies.
Overview of the cyberTech-ITEST project: an initiative to attract and prepare under-represented students for tomorrow's careers in the computing sciences

This paper describes an NSF-funded initiative involving 600 underrepresented high school students and 60 teachers designed to introduce underrepresented students to the numerous and varied career opportunities in the computing sciences, prepare them to succeed in college degree programs, and prepare their teachers to be effective in the computer science class room. The initiative has five components: 1) CyberTech I (Principles of Computing): An online introductory course for second-semester sophomores, 2) CyberTech II: A twenty day on-campus intense summer programming experience between the sophomore and junior year, 3) CT Games: A junior year video game programming experience to apply the programming knowledge gaining in CyberTech II, 4) AP Computer Science (using Java 5 as the programming language) taken during the senior year, and 5) training workshops for teachers to prepare them to teach computer programming. The overarching goal is to prepare students for a college-level degree program in the computing sciences by having them successfully complete the AP Computer Science course and exam while teaching the soft skills, such as team work, oral communication and problem solving necessary in a professional career. Additionally, role models from various industry sectors are utilized to introduce students to the exciting career opportunities in the computing sciences.
Prospective survey of parenteral nutrition in Switzerland: a three-year nation-wide survey

Abstract Background & Aims: The goals of this national survey were to determine the current PN practices and admixture formulations used in Switzerland. Methods: During three years, an annual questionnaire was sent to all heads of Swiss hospital pharmacies. Results: 92% of Swiss hospitals with a full-time pharmacist participated. Different PN systems were commonly used for adult patients: 2 commercial formulas in 2 or 3 compartments bags, 2 commercial formulas with/without lipid, 3 formulas compounded by the hospital pharmacy. For hospitalized adults, 83% of PN bags were administered as commercial multicompartment bags. The compounding of individualized PN admixtures takes place primarily in pharmacies of medium to large size hospitals. For pediatric PN, hospital compounding is routine because of individualized PN compositions and absence of commercially available standardized admixtures. Long-term home-PN was mostly delivered by hospital pharmacies (57%) or by private nutrition support home delivery services (37%). Most PN formula compositions complied with European guidelines and represented 2.6±2.0% of the hospital drug budget. Multi-disciplinary nutritional support teams were present in 52% of hospitals. Conclusion: In Switzerland, most PN for hospitalized adults were administered as commercial multi-compartment bags. The compounding of individualized PN admixtures were still important for pediatric patients and long-term home-PN.
Occult carbon monoxide poisoning: Validation of a prediction model

Headache and dizziness are early symptoms of carbon monoxide poisoning, occurring at carboxyhemoglobin levels of greater than 10 percent. Previously, it was shown that among patients presenting to an emergency department during the winter with headache or dizziness, an algorithm for obtaining carboxyhemoglobin levels on patients who used gas stoves for heating purposes or who had similarly affected cohabitants correctly identified all patients with carboxyhemoglobin levels greater than 10 percent. To test the validity of this retrospectively derived rule, 65 patients were studied who were unaware of any carbon monoxide exposure and who presented during the winter of 1986-1987 with headache or dizziness. The algorithm correctly identified three of four patients with carboxyhemoglobin levels greater than 10 percent (sensitivity = 75 percent) and correctly excluded 45 of 61 patients with lower levels (specificity = 74 percent). The presence of symptomatic cohabitants alone was an equally sensitive (75 percent) but more specific (90 percent) marker for elevated carboxyhemoglobin levels. When data from the two cohorts were combined, stepwise multiple regression identified number of cigarettes smoked daily (F = 8.66) and concurrently symptomatic cohabitants (F = 34.71) as significant predictors of the carboxyhemoglobin level. It is concluded that a retrospectively derived rule correctly identified most cases of occult carbon monoxide poisoning when applied prospectively, and that the presence of similarly affected cohabitants was the most reliable marker for a carbon monoxide-mediated illness.
Comparison of Surface Properties of Picornaviruses: Strategies for Hiding the Receptor Site from Immune Surveillance

Abstract The surface topology and sequence conservation of different picornaviruses have been compared using molecular graphics and statistical analyses. The comparisons suggest that the canyons, surface depressions encircling the fivefold axes, are the sites of receptor attachment of enteroviruses as well as human rhinovirus (HRV). In HRV14, the receptor binding footprint extends beyond the canyon (Olson et al. (1993), Proc. Natl. Acad. Sci. USA 90,507--511), but these more exposed regions are not conserved in polioviruses or minor receptor group rhinoviruses, suggesting some differences in receptor binding. When rhinoviruses are compared to other picorna- and parvoviruses, the surface sequence similarity relative to the similarity of buried residues is about the same. Thus, the effect of host immune surveillance on surface residues is similar. Therefore, it is probable that some means of protecting a conserved binding site from immune detection (such as a canyon) will be an essential requirement in other viruses. However, there may be other strategies for achieving this result. For instance, as in foot-and-mouth disease virus, the receptor attachment site of Mengo virus is associated with a flexible structural component which may inhibit the production of neutralizing antibodies that are able to recognize only one explicit conformation.
Large deletions result from breakage and healing of P. falciparum chromosomes

The human malaria parasite P. falciparum exhibits extensive strain-dependent chromosomal polymorphisms that have been implicated in the generation of antigenic variability in this organism. These polymorphisms can result in large deletions in chromosomes as determined by pulsed-field gradient gel electrophoresis. We have investigated the molecular basis for extensive deletions in chromosomes 2 and 8 in multiple geographic isolates of this parasite that result in the loss of expression of well-characterized parasite antigens. The structure of these polymorphic chromosomes reveal that a mechanism of chromosome breakage and healing by the addition of telomeric repeats most plausibly accounts for these karyotypes. Furthermore, the orientation of these gene fragments on their truncated chromosomes reveal that the healed chromosome originally associated with centromeric elements is mitotically stable and maintained. A model for the possible role of this mechanism in the complex parasite life-cycle is discussed.
Dynamic simulation of tool-mediated texture interaction

Humans can feel fine surface details through a rigid probe by attending to the high-frequency vibrations caused by contact. To aid our efforts in creating realistic virtual textures, we sought to understand the dynamics of such interactions through a combination of data collection and offline simulation. A handheld probe was fitted with interchangeable hemispherical tool tips, accelerometers, a force sensor, and a magnetic motion tracker and then used to record interactions with a sinusoidal grating. We mathematically modeled this system using planar rigid-body dynamics, a lumped-parameter model of the human hand, an offset surface for collision detection, and Hertzian contact mechanics at the point(s) of interaction. Tuning the parameters of the hand enabled the simulation output to closely match the lateral and axial tool accelerations recorded at four combinations of tool tip size and tool speed.
Degradation of SS316L bipolar plates in simulated fuel cell environment: Corrosion rate, barrier film formation kinetics and contact resistance

Abstract A potentiostatic polarization method is used to evaluate the corrosion behavior of SS316L in simulated anode and cathode environments of polymer electrolyte fuel cells. A passive barrier oxide film is observed to form and reach steady state within ∼10 h of polarization, after which time the total ion release rates are low and nearly constant at ∼0.4 μg cm−2 h−1 for all potentials investigated. The equilibrium film thickness, however, is a function of the applied potential. The main ionic species dissolved in the liquid are predominately Fe followed by Ni, that account for >90% of the steady-state corrosion current. The dissolution rate of Cr is low but increases systematically at potentials higher than 0.8 V. The experimental ion release rates can be correlated with a point defect model using a single set of parameters over a broad range of potentials (0.2–1 V) on the cathode side. The interfacial contact resistance measured after 48 h of polarization is observed to increase with increase in applied potential and can be empirically correlated with applied load and oxide film thickness. The oxide film is substantially thicker at 1.5 V possibly because of alteration in film composition to Fe-rich as indicated by XPS data.
Strategies for the Treatment of Methamphetamine Use Disorders Among Gay and Bisexual Men

SUMMARY There is a growing need for treatment services that specifically target methamphetamine for gay and bisexual men. There may be significant barriers for the client in engaging in a treatment program, including thought disturbances and paranoia. A high level of ambivalence in spite of extreme adverse consequences from use is also relatively common among those presenting for treatment. Many people do recover if they are willing to commit to a structured treatment plan. Models of treatment that have been shown to be successful include motivational interviewing (MI), cognitive behavioral therapy (CBT), and community reinforcement with contingency management. The Matrix Model was developed specifically for stimulant use disorders and includes many of these components as well as 12-step facilitation. Although it has been suggested that methamphetamine dependence may be more difficult to treat than other drug use dependence, empirical evidence suggests that success for methamphetamine treatment has not be...
INFERIOR OVARY AND GENERIC AFFINITIES OF GARRYA

Characters of the inflorescence and flower distinguish 2 sections in Gairya. Female flowers of sect. Garrya bear 2 small epigynous appendages, usually considered a rudimentary perianth. In sect. Fadyenia, female flowers are nude, but occasionally 2 more or less foliaceous bracts are partially adnate to the ovary, sometimes simulating the appearance of appendages in sect. Garrya. Authors who have observed this infer that the adnate bracts are homologous to epigynous appendages in sect. Garrya and that the ovary, therefore, cannot be considered inferior. This inference, if valid, would weigh against a close relationship between Garrya and Cornaceae. Clearing and sectioning show, however, that the vascular pattern in flowers of sect. Garrya is similar to the pattern in many Cornaceae. Perianth bundles are united with ventral carpellaries for most of their length, whereas bundles of the adnate bracts in sect. Fadyenia are associated with dorsal carpellary strands; therefore, the 2 kinds of appendages are not homologous. In gynoecial characters Garrya most closely resembles Griselinia and, to a lesser extent, Aucuba. These 3 genera probably had a common origin within the Cornaceae.
Hematologic reference values for African American children and adolescents

Anemia is prevalent among African American children. When evaluating pediatric patients for anemia, clinicians refer to the normative hematological reference values in reference textbooks. These reference values are used in spite of evidence that healthy African American people of all ages have average hemoglobin concentrations from 0.5 to 0.73 g/dl below those of Whites. In an earlier study, using samples from 2,161 healthy African American children from 2 to 18 years old, we found a statistically significant difference (P < 0.0001) in the mean hemoglobin value for each age group as compared to reference normative mean hemoglobin values. Here we present the results of a comparative analysis of the data set from our previous study and the data set from the National Health and Nutrition Examination Surveys III (NHANES III) 1988-1994. We found no statistically significant difference between these data sets with respect to the hemoglobin values for any age or sex group, confirming that African American children and adolescents have lower mean hemoglobin values than do Whites. Use of the reference hemoglobin values presented here will help prevent the misdiagnosis of anemia in African American children and thereby minimize unnecessary hematological workups and treatment.
Health disparities and stroke: the influence of insurance status on the prevalence of patient safety indicators and hospital-acquired conditions.

OBJECT The Agency for Healthcare Research and Quality patient safety indicators (PSIs) and the Centers for Medicare and Medicaid Services hospital-acquired conditions (HACs) are publicly reported quality metrics linked directly to reimbursement. The occurrence of PSIs and HACs is associated with increased mortality and hospital costs after stroke. The relationship between insurance status and PSI and HAC rates in hospitalized patients treated for acute ischemic stroke was determined using the Nationwide Inpatient Sample (NIS) database. METHODS The NIS was queried for all hospitalizations involving acute ischemic stroke between 2002 and 2011. The rate of each PSI and HAC was determined by searching the hospital records for ICD-9 codes. The SAS statistical software package was used to calculate rates and perform multivariable analyses to determine the effects of patient variables on the probability of developing each indicator. RESULTS The NIS query revealed 1,507,336 separate patient admissions that had in...
Judging the reflection of misoriented patterns in the right and left visual fields

The reported study demonstrates that performance asymmetries between normal or reflected letters presented in the right and left visual field favors the right visual field when stimulus patterns are blocked and rotated 90 degrees clockwise and favors the left visual field when they are blocked and rotated 90 degrees counterclockwise. When stimuli are rotated, the orientations of the patterns define a coordinate system that is independent of upright. It is suggested that our results are due to subjects sampling the different areas in the visual field relative to this coordinate system. The right visual field was given priority when the patterns were oriented so their "tops" were pointing rightward and the left visual field was given priority when the patterns were oriented so their tops were pointing leftward. Neither differences in the stimulus image on the retina in the two rotated conditions, eye movements, nor direct access to one hemisphere or the other could account for these effects.
Reevaluation of the Life Cycle of Tuber magnatum

Tuber spp. are ectomycorrhizal ascomycetes that produce ascocarps known as truffles. Basic aspects of Tuber biology have yet to be fully elucidated. In particular, there are conflicting hypotheses concerning the mating system and the ploidy level of the mycorrhizal and truffle hyphae. We used polymorphic microsatellites to compare the allelic configurations of asci with those from the network of the surrounding hyphae in single Tuber magnatum truffles. We then used these truffles to inoculate host plants and evaluated the microsatellite configurations of the resulting mycorrhizal root tips. These analyses provide direct evidence that T. magnatum outcrosses and that its life cycle is predominantly haploid. In addition to its scientific significance, this basic understanding of the T. magnatum life cycle may have practical importance in developing strategies to obtain and select nursery-produced mycorrhizal plants as well as in the management of artificial plantations of this and other Tuber spp.
Experience-Dependent Remodeling of Basket Cell Networks in the Dentate Gyrus

The structural organization of neural circuits is strongly influenced by experience, but the underlying mechanisms are incompletely understood. We found that, in the developing dentate gyrus (DG), excitatory drive promotes the somatic innervation of principal granule cells (GCs) by parvalbumin (PV)-positive basket cells. In contrast, presynaptic differentiation of GCs and interneuron subtypes that inhibit GC dendrites is largely resistant to loss of glutamatergic neurotransmission. The networks of PV basket cells in the DG are regulated by vesicular release from projection entorhinal cortical neurons and, at least in part, by NMDA receptors in interneurons. Finally, we present evidence that glutamatergic inputs and NMDA receptors regulate these networks through a presynaptic mechanism that appears to control the branching of interneuron axons. Our results provide insights into how cortical activity tunes the inhibition in a subcortical circuit and reveal new principles of interneuron plasticity.
Dynamic and Distributed Somatosensory Representations as the Substrate for Cortical and Subcortical Plasticity

Abstract Seconds after a cutaneous deafferentation is induced in adult animals, a complex process of plastic reorganization is triggered in the subcortical and cortical structures that form the somatosensory system. This process, which leads to the immediate unmasking of novel neuronal sensory responses, continues to evolve for many weeks and months until most of the neuronal tissue deprived of its original afferent input gains responsiveness to surrounding skin territories. Here, I propose that the existence of dynamic and distributed sensory representations throughout the somatosensory system offers the substrate for the occurrence of immediate plastic remapping of the body surface following either a peripheral injury or a change in sensory experience.
ON BOUNDARY CONDITIONS FOR FIRST-ORDER SYMMETRIC HYPERBOLIC SYSTEMS WITH CONSTRAINTS

The Cauchy problem for many first-order symmetric hyperbolic (FOSH) systems is constraint preserving, i.e. the solution satisfies certain spatial differential constraints whenever the initial data does. Frequently, artificial space cut-offs are performed for such evolution systems, usually out of the necessity for finite computational domains. However, it may easily happen that boundary conditions at the artificial boundary for such a system lead to an initial boundary value problem which, while well-posed, does not preserve the constraints. Here we consider the problem of finding constraint-preserving boundary conditions for constrained FOSH systems in the well-posed class of maximal non-negative boundary conditions. Based on a characterization of maximal non-negative boundary conditions, we discuss a systematic technique for finding such boundary conditions that preserve the constraints, pending that the constraints satisfy a FOSH system themselves. We exemplify this technique by analyzing a system of wave equations in a first-order formulation subject to divergence constraints.
Are physicians asking about tobacco use and assisting with cessation? Results from the 2001-2004 national ambulatory medical care survey (NAMCS).

Abstract Objective. The objective of this study was to determine if providers asked patients about tobacco and assisted tobacco users with cessation. Methods. The data source is the 2001–2004 National Ambulatory Medical Care Survey, which is an annual survey of outpatient visits. The prevalence of “asking” about tobacco use, providing “assistance” with tobacco cessation, and prescription of pharmacotherapy for cessation were estimated. A logistic regression model was fit to the data to determine if any variables were related to “asking” about tobacco use and providing “assistance” with cessation. Results. Overall, 32% of patient charts did not include information about tobacco use, 81% of smokers did not receive assistance and less than 2% received a prescription for pharmacotherapy. Asking about tobacco use varied with presence of chronic disease, cardiovascular disease counseling, geographical region, whether the physician was the patient's primary provider, time spent with physician, age, and gender. Providing assistance with cessation varied with the presence of chronic diseases, cardiovascular disease counseling, region of the country, provider type, insurance type, and time spent with the physician. Conclusions. Methods for improving adherence to the Clinical Practice Guideline for cessation, such as medical school curricula or educational programs for practicing providers, should be examined.
Hypernovae, collapsars, and gamma-ray bursts

Cosmic gamma-ray bursts now appropriately hold the distinction of being the “largest explosions in the universe”. Their afterglows are often brighter than supernovae, thus often referred to as “hypernovae”. Their kinetic energies may also be greater, or at least highly collimated, and require a new source of energy. Recent photometric and spectroscopic observations of the afterglow emission have provided a major breakthrough in our understanding of these powerful explosions. The data place at least some bursts at large distances and in association with faint host galaxies. But what is (or are) the underlying cause(s) of these violent events? The answer to this question remains uncertain, but several theoretical arguments point towards the creation of hyperaccreting black holes with accretion rates from 10−4 to 10 solar masses per second, whose accretion disks produce narrow jets of relativistically expanding plasma. We review the basic concepts of one of these models, the “collapsar model”.
Measurements at radio frequencies

IT IS interesting to recall that this art is less thana century old1 and that the early experimenters actually worked in the frequency range now called “hyper frequencies.”
Photoaffinity labeling of diphtheria toxin fragment A with 8-azidoadenosyl nicotinamide adenine dinucleotide.

Diphtheria toxin fragment A (DT-A) is an important enzyme in the class of mono(ADP-ribosyl)transferases. To identify peptides and amino acid residues which form the NAD+ binding site of DT-A using a photoaffinity approach, the photoprobes nicotinamide 8-azidoadenine dinucleotide (8-N3-NAD) and nicotinamide 2-azidoadenine dinucleotide (2-N3-NAD) were synthesized. Binding studies gave an IC50 of 2.5 μM for 8-N3-NAD and 5.0 μM for 2-N3-NAD. Irradiation of DT-A and low concentrations of [α-32P]-8-N3-NAD with short-wavelength UV light resulted in rapid covalent incorporation of the photoprobe into the protein. The photoincorporation was shown to be specific for the active site with a stoichiometry of photoincorporation of 75−80%. After proteolytic digestion of photolabeled DT-A, derivatized peptides were isolated using immobilized boronate affinity chromatography followed by reversed phase HPLC. Radiolabeled peptides originating from two regions of the protein were identified. Chymotryptic digestion produced l...
Focal encephalitis simulating neoplasm.

A case is reported which documents a seldom described angiographic appearance of focal encephalitis. A vascular blush with premature venous filling led to a preoperative diagnosis of neoplasm. Histologic examination revealed inflammatory disease and the patient's high serum antibody titer to herpes simplex suggested this as the etiologic agent.