cssi/SciSciGPT-SciSciNet huggingface dataset:
Trends and risk factors for HIV-1 seropositivity among outpatient children, Kinshasa, Zaire.

To investigate recent trends in pediatric HIV-1 infection and the early impact of a blood screening program begun in 1 hospital in Kinshasa Zaire the authors evaluated 1110 consecutive children seen in the pediatric emergency ward of the citys largest hospital in November 1988. The HIV-1 seroprevalence was 5.0% not significantly higher than the 3.8% rate found in 1986 (p=0.2). The seropositivity rate was bimodally distributed; children or= 1 year of age were more likely than seronegative children to be anemic and to have signs of malnutrition. A previous blood transfusion was associated with HIV-1 seropositivity among children >or= 1 year of age (OR=5.4 p or= 1 year of age had received a transfusion (etiological fraction=42%). The association with seropositivity was higher for those who had received a transfusion before 1987 than for those who received 1 since that time (OR=4.8 p=0.01). These findings suggest a relatively stable high pediatric HIV-1 seroprevalence in Kinshasa and a decreased but continuous risk of transfusions. Expansion of currently limited blood transfusion screening programs and the development of new strategies for limiting transfusions and anemia prevention are necessary. (authors modified)
Cysteine accessibility probes timing and extent of NBD separation along the dimer interface in gating CFTR channels.

Cystic fibrosis transmembrane conductance regulator (CFTR) channel opening and closing are driven by cycles of adenosine triphosphate (ATP) binding–induced formation and hydrolysis-triggered disruption of a heterodimer of its cytoplasmic nucleotide-binding domains (NBDs). Although both composite sites enclosed within the heterodimer interface contain ATP in an open CFTR channel, ATP hydrolysis in the sole catalytically competent site causes channel closure. Opening of the NBD interface at that site then allows ADP–ATP exchange. But how frequently, and how far, the NBD surfaces separate at the other, inactive composite site remains unclear. We assessed separation at each composite site by monitoring access of nucleotide-sized hydrophilic, thiol-specific methanothiosulfonate (MTS) reagents to interfacial target cysteines introduced into either LSGGQ-like ATP-binding cassette signature sequence (replacing equivalent conserved serines: S549 and S1347). Covalent MTS-dependent modification of either cysteine while channels were kept closed by the absence of ATP impaired subsequent opening upon ATP readdition. Modification while channels were opening and closing in the presence of ATP caused macroscopic CFTR current to decline at the same speed as when the unmodified channels shut upon sudden ATP withdrawal. These results suggest that the target cysteines can be modified only in closed channels; that after modification the attached MTS adduct interferes with ATP-mediated opening; and that modification in the presence of ATP occurs rapidly once channels close, before they can reopen. This interpretation was corroborated by the finding that, for either cysteine target, the addition of the hydrolysis-impairing mutation K1250R (catalytic site Walker A Lys) similarly slowed, by an order of magnitude, channel closing on ATP removal and the speed of modification by MTS reagent in ATP. We conclude that, in every CFTR channel gating cycle, the NBD dimer interface separates simultaneously at both composite sites sufficiently to allow MTS reagents to access both signature-sequence serines. Relatively rapid modification of S1347C channels by larger reagents—MTS-glucose, MTS-biotin, and MTS-rhodamine—demonstrates that, at the noncatalytic composite site, this separation must exceed 8 A.
Solute interactions in multicomponent solutions

The mathematical formalism for description of solute interactions in dilute, multicomponent solutions should be consistent with (a) the Gibbs-Duhem relations and associated thermodynamic definitions and (b) the principle of regularity of dilute solutions due primarily to Darken. Wagner's original suggestion that Inγi and Inγj be represented by Taylor's series expansions, withei(j) = ej(i), meets both these criteria if and only if both first and second order terms are included, with second order coefficients equal to the negatives of the first order coefficients, as in the Darken quadratic formalism. The resulting Wagner-Darken quadratic formalism can be modified for better fit to some experimental data, without loss of rigor, by different choices of components and different definitions of activity coefficients. The recent conjectures of Sukiennik and Olesinski about the thermodynamic validity of the original Wagner formalism are addressed briefly.
Investigating Obsolescence: Studies in Language Contraction and Death

Investigating Obsolescence: Studies in Language Contraction and Death. Nancy C. Dorian. ed. Studies in the Social and Cultural Foundations of Language, 7. Cambridge: Cambridge University Press, 1989. 445 pp. $59.50 (cloth)
Chemical, biological, and immunological characterization of mono- and diiodo-thyrotropin releasing factor

Abstract Iodination of thyrotropin releasing factor (TRF) with chloramine-T and NaI at pH 7.5 produces both mono- and diiodo-TRF as well as unreacted TRF and I − . The four compounds can be separated by ion-exchange chromatography on SP-Sephadex C-25, using a stepwise gradient of 0.01 m MH 4 OAc at pH 3.5, 5.2 and 7.2. The monoiodo-TRF was characterized by nuclear magnetic resonance, mass spectra, and elemental analysis as [Im-5-iodo-His 2 ]-TRF while the diiodo-TRF was similarly characterized as [Im-2,5-diiodo-His 2 ]-TRF. Both iodination products showed no thyrotropin releasing activity at doses up to 1 μg in the in vivo mouse bioassay. The specific binding of mono- and diiodo-TRF was measured against three different TRF antisera. In the absence of TRF, antisera A and C bound more diiodo-TRF than monoiodo-TRF while antiserum B seemed to bind both tracers equally. In all cases steeper curves were produced when diiodo-TRF was displaced by synthetic TRF.
Neurogenesis in frogs after early larval treatment with somatotropin or prolactin

Abstract Rana pipiens tadpoles were given six injections (over an 11-day period) of either prolactin, somatotropin, or saline, during early stages of larval development. Brain and body growth and aspects of brain nucleic acid metabolism were studied at frequent intervals through metamorphosis. The three groups showed no differences in morphology, rates of development, or general patterns of body growth—although the extent of body growth was increased in the experimental groups. In contrast, both hormones produced profound and very different effects on neurogenesis. Increases in brain weight and DNA and RNA content after prolactin treatment were modest during the early stages, but ultimately extensive; and this enhancement embraced all three major regions: forebrain, midbrain, and hindbrain. Labeling experiments with tritiated thymidine showed that prolactin caused both an increase in brain DNA synthesis (during the early and especially the mid-larval stages) and a decrease in neural cell death (during late stages). Somatotropin greatly enhanced brain weight and DNA content (in all three brain regions) during the period of its administration. Labeling experiments attributed this to a period of very rapid DNA synthesis. By the end of metamorphosis, however, the somatotropin-treated animals showed only slight advantages over the controls in brain weight and nucleic acid content—although the forebrain remained significantly enhanced. Possible mechanisms of hormone action and roles for these hormones in normal neurogenesis are discussed, as are some of the technical problems in experiments of this sort. Finally, comments are made on normal neurogenesis based on observations of the control population.
Recovery of lanthanum from didymium chloride with Di(2-ethylhexyl)-phosphoric acid as solvent☆

Abstract Lanthanum of about 99·8 per cent purity was obtained from didymium chloride using two batch multistage countercurrent extraction cascades with 1 M D2EHPA as solvent. In the first cascade the La was concentrated in the raffinate, and in the second cascade the La was purified. The over-all recovery of La was 60 per cent. Batch tests showed that the solvent could be reused repeatedly with no loss in extracting power.
Improved assessment of control in intermittent exotropia using multiple measures.

Purpose To develop and validate an improved measure of control in intermittent exotropia (XT). Design Prospective, noninterventional case series. Methods Twelve children with intermittent XT were evaluated during 4 sessions (2 hours apart) over a day, on 2 separate days (8 sessions per child). Control was standardized using a scoring system and quantified 3 times during each examination. Overall control for a day was calculated as the mean of all 12 measures. Single measures of control and the mean of 2 (double) and 3 (triple) measures over the examination were compared with the respective day mean, and first-day measures were compared to the second-day mean. Results At distance, 17% (49/287, 95% confidence interval [CI] 13% to 22%) of single measures differed from the day mean, whereas only 8% (16/191, 95 CI 5% to 13%) of double measures and 5% (5/95, 95% CI 2% to 12%) of triple measures differed. Comparing day 1 measures to overall mean for day 2, 17% (24/143, 95% CI 11% to 24%) of single measures and 17% (22/130, 95% CI 11% to 24%) of double measures differed by more than 1 level, whereas 11% (5/47, 95% CI 4% to 23%) of triple measures differed. Conclusions The mean of 3 assessments of control during a clinic examination better represents overall control than a single measure.
Intersection homology theory via rectifiable currents

Here is given a rectifiable currents’ version of intersection homology theory on stratified subanalytic pseudomanifolds. This new version enables one to study some variational problems on stratified subanalytic pseudomanifolds. We first achieve an isomorphism between this rectifiable currents’ version and the version using subanalytic chains. Then we define a suitably modified mass on the complex of rectifiable currents to ensure that each sequence of subanalytic chains with bounded modified mass has a convegent subsequence and the limit rectifiable current still satisfies the perversity condition of the approximating chains. The associated mass minimizers turn out to be almost minimal currents and this fact leads to some regularity results.
Dietary conjugated nonadecadienoic acid prevents adult-onset obesity in nescient basic helix–loop–helix 2 knockout mice

Conjugated linoleic acid (CLA) has been extensively studied during the last two decades with regard to its effects on controlling body composition. As a cognate to CLA, conjugated nonadecadienoic acid (CNA) has been previously reported to reduce body fat more effectively than CLA. However, it is not known whether CNA supplementation can influence adult-onset obesity. Thus, the purpose of this study was to evaluate the effects of dietary CNA on the prevention of adult-onset inactivity-induced obesity using nescient basic helix-loop-helix 2 knockout (N2KO) mice. CNA supplementation at 0.1 w/w% level starting in the preobese state significantly prevented the reduction of voluntary movement and the increase in weight gain in N2KO mice during the experimental period compared to wild-type animals. In both wild-type and N2KO mice, respiratory exchange ratio was significantly reduced by CNA treatment during light and dark cycles, and dietary CNA significantly increased energy expenditure in N2KO mice. Selected gene expression profiles in white adipose tissue, muscle or liver showed a beneficial action of CNA on lipid metabolism and energy expenditure. These findings suggest that CNA could prevent adult-onset obesity by enhancing voluntary activity and energy expenditure in N2KO mice.
Thermal infrared opacity of the Mars atmosphere

An analytical technique is presented for the deriving Mars atmosphere opacity from data furnished by the IR Thermal Mapper (IRTM) instruments on the Viking landers. Each IRTM features four telescopes for viewing Mars in six spectral bands and seven spatial fields of view. The present study focuses on 20 microns measurements of the thermal inertia, 0.3-3.0 microns data for the surface albedo, and, finally, the 7, 9, and 15 microns data for the actual opacity derivations. The model takes into account the atmospheric temperature profile, scattering by dust, the surface emissivity and the variation of the surface/atmosphere temperature discontinuity. Analyses are carried out of the possible error factors and the model is used to generate opacity histories for the two Viking Lander sites. The results, when compared with other astronomical data, indicate that the method is sufficiently accurate to use opacity data to analyze the processes of storm genesis and to study local storms.
Solution-deposited zinc oxide and zinc oxide/pentacene bilayer transistors: high mobility n-channel, ambipolar and nonvolatile devices

A solution processed n-channel zinc oxide (ZnO) field effect transistor (FET) was fabricated by simple dip coating and subsequent heat treatment of a zinc acetate film. The field effect mobility of electrons depends on ZnO grain size, controlled by changing the number of coatings and zinc acetate solution concentration. The highest electron mobility achieved by this method is 7.2 cm2 V−1 s−1 with On/Off ratio of 70. This electron mobility is higher than for the most recently reported solution processed ZnO transistor. We also fabricated bilayer transistors where the first layer is ZnO, and the second layer is pentacene, a p-channel organic which is deposited by thermal evaporation. By changing the ZnO grain size (or thickness) this type of bilayer transistor shows p-channel, ambipolar and n-channel behavior. For the ambipolar transistor, well balanced electron and hole mobilities are 7.6 × 10−3 and 6.3 × 10−3 cm2 V−1 s−1 respectively. When the ZnO layer is very thin, the transistor shows p-channel behavior with very high reversible hysteresis. The nonvolatile tuning function of this transistor was investigated.
Gametogenic responses of the testis in spotted munia (Lonchura punctulata; Aves) to oral administration of lithium chloride.

In the present study, the effects of orally-administered lithium on testicular morphology were examined in the spotted munia (Lonchura punctulata), a seasonally breeding sub-tropical finch. Adult males were procured from natural populations during the month of August, a time when these birds begin to show seasonal reproductive maturity in an annual cycle. Both during the period of acclimation, and throughout the subsequent experimental period, the birds were maintained in an open aviary simulating natural environmental conditions. Lithium was dissolved in distilled water and was administered via the oral route by means of a commercially available stomach-tube. A total of five experimental groups were utilized. The first group (Group A) served as control and received lithium-free distilled water in a similar manner. In the remaining four groups, lithium was administered daily as follows: Group B (2.5 mEq/Kg body weight for 5 days); Group C (2.5 mEq/Kg for 10 days); Group D (5.0 mEq/Kg for 5 days) and Group...
Dissolution kinetics of meta-torbernite under circum-neutral to alkaline conditions

Environmental context. Uranium-phosphate minerals have been identified as a long-term controlling phase that limit the mobility of uranium to groundwater in many contaminated subsurface environments. Complex, coupled processes confound the ability to isolate the rates attributed to individual processes. Results of this investigation provide the necessary information to refine current prediction on the release and long-term fate of uranium in subsurface environments. Abstract. The purpose of this investigation was to conduct a series of single-pass flow-through (SPFT) tests to (1) quantify the effect of temperature (23–90°C) and pH (6–10) on meta-torbernite dissolution; (2) compare the dissolution of meta-torbernite to other autunite-group minerals; and (3) evaluate the effect of aqueous phosphate on the dissolution kinetics of meta-torbernite. Results presented here illustrate meta-torbernite dissolution rates increase by ~100× over the pH interval of 6 to 10, irrespective of temperature. The power law coefficient for meta-torbernite, η = 0.59 ± 0.07, is greater than that quantified for Ca-meta-autunite, η = 0.42 ± 0.12. This suggests the stability of meta-torbernite is greater than that of meta-autunite, which is reflected in the predicted stability constants. The rate equation for the dissolution of meta-torbernite as a function of aqueous phosphate concentration is log rdissol (mol m–2 s–1) = –4.7 × 10–13 + 4.1 × 10–10[PO43–].
Hardening of Red King Crab Paralithodes camtschaticus (Tilesius, 1815) Shells after Molting

Abstract Shell hardness was measured with a durometer for female red king crabs, Paralithodes camtschaticus, held in the laboratory over variable periods up to 107 days after molting. The data were fit best by a hyperbolic equation, with parameters β0 = 0.216 and β1 = 0.019 (R2 = 0.976, n = 199), and an asymptotic value of 50.7 durometer units (DU). The time required to reach 90% of complete shell hardness (H90 = 45.6 DU) was calculated to be 74.2 days. Molting dates for all crabs were hindcast using the last measurement that was less than H90 and were within 2.5 ± 6.4 days (mean ± SE, n = 34) of the actual molting date.
Activity coefficients of single electrolytes in concentrated solutions derived from a quasi-lattice model

This paper describes a new model to calculate the mean activity coefficients of dissociated electrolytes in concentrated solutions. It is based on three assumptions: (i) a quasi-lattice arrangements of ions in solution; (ii) a contribution from ion-water interactions to the mean activity coefficients; (iii) a concentration dependence of the dielectric constant. The mean activity coefficients of thirteen strong electrolytes from moderately dilute solutions to saturated solutions are found to correlate well by this model. For dilute solutions, a limiting equation in which only ion-specific parameters are required is proposed. It is suggested that specific ionwater interactions might be the major source of the nonideality of strong electrolyte solutions at high concentrations.
The role of pulmonary vascular contractile protein expression in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is associated with refractory vasoconstriction and impaired NO-mediated vasodilatation of the pulmonary vasculature. Vascular tone is regulated by light chain (LC) phosphorylation of both nonmuscle (NM) and smooth muscle (SM) myosins, which are determined by the activities of MLC kinase and MLC phosphatase. Further, NO mediated vasodilatation requires the expression of a leucine zipper positive (LZ+) isoform of the myosin targeting subunit (MYPT1) of MLC phosphatase. The objective of this study was to define contractile protein expression in the pulmonary arterial vasculature and vascular reactivity in PAH. In severe PAH, compared to controls, relative LZ+MYPT1 expression was decreased (100 ± 14% vs. 60 ± 6%, p<0.05, n=7-8), and NM myosin expression was increased (1 5 ± 4% vs. 53 ± 5% of total myosin, p<0.05, n=4-6). These changes in contractile protein expression should alter vascular reactivity; following activation with Ang II, force activation and relaxation were slowed, and sustained force was increased. Further, the sensitivity to ACh-mediated relaxation was reduced. These results demonstrate that changes in the pulmonary arterial SM contractile protein expression may participate in the molecular mechanism producing both the resting vasoconstriction and the decreased sensitivity to NO-mediated vasodilatation associated with PAH.
The quantitative trait gene latexin influences the size of the hematopoietic stem cell population in mice

We mapped quantitative trait loci that accounted for the variation in hematopoietic stem cell (HSC) numbers between young adult C57BL/6 (B6) and DBA/2 (D2) mice. In reciprocal chromosome 3 congenic mice, introgressed D2 alleles increased HSC numbers owing to enhanced proliferation and self-renewal and reduced apoptosis, whereas B6 alleles had the opposite effects. Using oligonucleotide arrays, real-time PCR and protein blots, we identified latexin (Lxn), a gene whose differential transcription and expression was associated with the allelic differences. Expression was inversely correlated with the number of HSCs; therefore, ectopic expression of Lxn using a retroviral vector decreased stem cell population size. We identified clusters of SNPs upstream of the Lxn transcriptional start site, at least two of which are associated with potential binding sites for transcription factors regulating stem cells. Thus, promoter polymorphisms between the B6 and D2 alleles may affect Lxn gene expression and consequently influence the population size of hematopoietic stem cells.
My right I: Deception detection and hemispheric differences in self-awareness

Previous research has indicated a relationship between the ability to detect deceit and self-awareness. In this study, 2 experiments were conducted to further investigate this relationship. 32 (28 females and 4 males) undergraduate students listened to 116 true and false statements with headphones in an attempt to determine which statements contained deception. The participants also completed a variety of self-awareness questionnaires including the Schizotypal Personality Questionnaire (Raine, 1991) and the Self-Consciousness Scale (Fenigstein, Scheier, & Buss, 1975). An additional 11 participants were tested with the statements played in reverse to determine the role of information processing. It was found there was a correlation between self-awareness and deception detection. These data support the hypothesis that self-awareness is related to mental state attribution (theory of mind).
The demographic history of colonial New England.

The central fact of the demographic history of early North America is rapid growth. Both Canada and the white population of the English colonies experienced increases of 2½ percent per year during the eighteenth century. Seventeenth-century rates, beginning from a low base and more influenced by immigration, were even higher. In contrast, the expansion of population in early modern Europe rarely exceeded 1 percent per annum over an extended period. Since Franklin and Malthus, interpretations of early American demography have centered on the high fertility associated with near universal marriage for women at a low average age. The extremely youthful population, high dependency ratio, and one of the largest mean census family sizes ever recorded all follow from the high level of fertility.
Positive Psychological Interventions for Children: A Comparison of Gratitude and Best Possible Selves Approaches.

Many studies have found benefits of positive psychological interventions, such as gratitude promotion or thinking about best possible selves, for adolescents and adults. Almost no research, however, has been conducted on the efficacy of such interventions for children. The authors' primary goal was to compare the outcomes of gratitude promotion and best possible selves interventions to a control condition, using a sample of elementary school-aged children (N = 62, ages 5-11 years). Children participated in once-weekly intervention sessions in which they were asked to draw a picture of something for which they were grateful that day (gratitude condition), a future version of themselves as happy and engaged (best possible selves condition), or something they had done that day (control condition). Analyses of the content of children's drawings indicated that children of this age were capable of articulating things for which they were grateful and positive future selves. Outcomes for the gratitude condition did not differ from the control condition; however, participants in the best possible selves condition showed greater gains in self-esteem than those in the gratitude or control conditions.
Response strength in open and closed economies

Abstract Response strength was measured in open and closed economies using tests of resistance to change. In Experiment 1, responses were reinforced under fixed ratio schedules of reinforcement that ranged from 40 to 240. Rats in the open economy responded during a 45-min session and were immediately fed supplemental food in their home cage. Rats in the closed economy received all of their food by responding in an extended session. At each fixed ratio value, responding was disrupted by response-independent food and extinction, and response strength was indexed by the degree of response suppression relative to baseline. Response rate in the closed economy was higher than in the open economy, but no consistent difference in response strength was found. Experiment 2 was a replication of Experiment 1 using two open economy groups. One group was maintained at 80% free-feeding body weight for the entire experiment, and the other group was maintained at 90% under fixed ratio 40, 85% under fixed ratio 80, 75% under fixed ratio 160, and 70% under fixed ratio 240. Response suppression from free food and extinction was the same for both groups, suggesting that increased food deprivation under larger fixed ratios observed in Experiment 1 did not contribute to the results of that experiment. The data suggest that the ability to respond at relatively high rates under very large fixed ratio schedules of reinforcement in a closed economy does not reflect greater response strength as measured by the resistance-to-change paradigm.
Effects of NEXRAD Graphical Data Resolution and Direct Weather Viewing on Pilot Judgments of Weather Severity and Willingness to Continue Flight

A study was conducted to determine how variations in displayed NEXRAD weather data resolution interact with the pilot's direct view of weather. Pilots (32) were assigned to one of 4 groups; 8 km, 4 km, or 2 km resolution, and a baseline condition without NEXRAD imagery. Each flew the simulator from Santa Rosa, NM, with the intent to land at Albuquerque. Heavy precipitation moved into the area during the flight, and pilots were required to decide, using both the NEXRAD data and their out-the-window view, whether to continue or to divert to an alternate airport. Pilots spent more time looking at higher resolution images than at the lower resolution ones. Posttest NEXRAD image judgments reinforced the notion that higher resolution images are likely to encourage pilots to continue flights with the expectation that they can fly around or between significant weather features. The presence of out-the-window viewable weather phenomena was seen to have a significant effect on how pilots regarded the NEXRAD data.
Change We Can Believe In? Using Political Science to Predict Policy Change in the Obama Presidency

Based on the results of the 2008 presidential and congressional elections, an analysis using theories and methods of modern political science (pivotal politics theory, ideal point estimates, and bootstrap simulations) suggests that the conditions are ripe for real policy change. Specifically, we should expect policies to move significantly in a liberal direction, few or no policies should move in a conservative direction, and many of the outcomes will be moderate or somewhat to the left of center (rather than far left). Furthermore, the predictions depend as much on partisan polarization and the results of the congressional election as they do on the outcome of presidential election itself.
Review Article : Clinical Features and Pathobiology of Neurofibromatosis 1:

Neurofibromatosis 1 is a progressive multisystem disorder. The hallmark feature is the occurrence of nerve sheath tumors, neurofibromas. Other features include tumors such as optic gliomas and malignant peripheral nerve sheath tumors. There are also nontumor manifestations, such as skeletal dysplasia and learning disabilities. Since the NF1 gene was identified, much has been learned about the molecular genetics of the disorder; recently, this has led to insights about pathogenesis. Ultimately, it is hoped that this will be translated into specific means of treatment. This review describes the various clinical features of neurofibromatosis 1 and considers them in the context of the pathophysiology of the disorder.
Bovine adrenal 20α-hydroxysteroid oxido-reductase and variations of activity with age

Abstract Bovine adrenal 20α-hydroxysteroid oxido-reductase has been measured in the glands from animals of various ages. The substrates 20α-hydroxyprogesterone and 17α,20α-dihydroxyprogesterone were employed under conditions favoring oxidation. The highest activity was found in the newborn and older but prepuberal glands and very little in fetal or mature tissue. This activity was notable with 20α-hydroxyprogesterone whereas 17α,20α-dihydroxyprogesterone remained unoxidized. These findings with respect to age may partly explain the adrenarche wherein the production of C-19 steroids by the adrenal rises sharply around the time of sexual maturation. Some work indicates that 20-keto and not 20-hydroxy C-21 steroids are precursors to side chain cleavage. The higher level of 20-hydroxysteroid oxido-reductase activity in the prepuberal organs suggests that this enzyme diverts possible C-21 precursors from this cleavage reaction.
On the quantization of the coefficient of the abelian Chern-Simons term☆

Abstract We point out that the coefficient of the abelian Chern-Simons term need not be quantized, even in the case of compact U(1) group. Instead, the quantum theory is qualitatively different for integer or rational values of that coefficient.
Racial/ethnic differences in the prevalence of gestational diabetes mellitus and maternal overweight and obesity, by nativity, Florida, 2004-2007.

Objective: We examined the risk of gestational diabetes mellitus (GDM) among foreign-born and U.S.-born mothers by race/ethnicity and BMI category. Design and Method: We used 2004-2007 linked birth certificate and maternal hospital discharge data of live, singleton deliveries in Florida to compare GDM risk among foreign-born and U.S.-born mothers by race/ethnicity and BMI category. We examined maternal BMI and controlled for maternal age, parity, and height. Results: Overall, 22.4% of the women in our study were foreign born. The relative risk (RR) of GDM among women who were overweight or obese (BMI ≥ 25.0 kg m−2) was higher than among women with normal BMI (18.5-24.9 kg m−2) regardless of nativity, ranging from 1.3 (95% confidence interval (CI) = 1.0, 1.9) to 3.8 (95% CI = 2.1, 7.2).Foreign-born women also had a higher GDM risk than U.S.-born women, with RR ranging from 1.1 (95% CI = 1.1, 1.2) to 2.1 (95% CI = 1.4, 3.1). This finding was independent of BMI, age, parity, and height for all racial/ethnicity groups. Conclusions: Although we found differences in age, parity, and height by nativity, these differences did not substantially reduce the increased risk of GDM among foreign-born mothers. Health practitioners should be aware of and have a better understanding of how race/ethnicity and nativity can affect women with a high risk of GDM. Although BMI is a major risk factor for GDM, it does not appear to be associated with race/ethnicity or nativity.
Independence of cocaine sensitization and amygdaloid kindling in the rat.

Abstract The reported sensitization to repeated administration of cocaine has been described as a type of pharmacological kindling resembling the seizure development seen with repeated electrical stimulation of certain brain sites. If these two phenomena share a common neural mechanism, prior chronic administration of cocaine would be expected to facilitate the process of subsequent electrical kindling. Rats were pretreated with saline or cocaine (40 mg/kg IP) daily for 21 days, followed by electrical stimulation of the basolateral amygdala. Progressive sensitization to the behavioural effects of cocaine administration occurred. However, no significant differences in the subsequent development of electrically kindled seizures were observed between the cocaine and saline-treated groups. These results suggest that cocaine sensitization and electrical kindling of the amygdala are subserved by independent neural mechanisms.
Infrared Absorption of Indium Antimonide

Infrared absorption in InSb near the absorption edge has been interpreted as the superposition of two indirect transitions requiring phonons of 100\ifmmode^\circ\else\textdegree\fi{} and 30\ifmmode^\circ\else\textdegree\fi{}, the former transition involving the smaller electronic energy gap. The first transition is consistent with a band scheme having electrons at the center of the zone and holes either at the corner of the zone or about halfway along the [1,1,1] line. The other transition may indicate a second hole with an energy gap about 0.025 ev larger than that of the first.
SOS-based solution approach to polynomial LPV system analysis and synthesis problems

Based on sum-of-squares (SOS) decomposition, we propose a new solution approach for polynomial linear parameter-varying (LPV) system analysis and control synthesis problems. Instead of solving matrix variables over positive cone, the SOS approach tries to find a suitable decomposition to verify the positiveness of given polynomials. The complexity of the SOS-based numerical method is polynomial of the problem size, and is computationally attractive. This approach also leads to more accurate solutions to LPV systems than most existing relaxation methods. Several examples have been used to demonstrate benefits of the SOS-based solution approach.
Energies and bounds from perturbative approximations to the Bloch-Horowitz effective Hamiltonian

Bloch-Horowitz perturbation theory is applied to the calculation of approximate energies and model-space eigenvectors, for the solvable large-matrix Hamiltonian $H$ used by Pittel, Vincent, and Vergados. Two types of upper and lower bounds to the energies are discussed: moment-theory bounds, obtained by applying moment theory to the terms of perturbation theory, and norm bounds, derived from the expectation $\overline{E}$ and variance ${\ensuremath{\sigma}}^{2}$ of $H$ with respect to an eigenvector approximated by n th order perturbation theory ($n\ensuremath{\le}6$). It is shown that lower bounds cannot be constructed unless some fourth-order quantity is known. The upper bounds are generally stricter than the lower bounds. All of the bounds apply even when back-door intruder states cause perturbation theory to diverge; but they lose their rigor and become "quasibounds" when there are physical intruders. The moment-theory and norm lower quasibounds always require estimation of a parameter. For the solvable Hamiltonians, it is shown that this can be done quite reliably, and that the resulting quasibounds are tight enough to have some practical utility. The energy-independent effective interaction V is constructed and its errors are displayed and discussed. Finally, a certain [1/2] pseudo-Pad\'e approximant is empirically shown to give energies with a mean absolute error of less than 0.3 MeV in all cases.
The optimal linear regulator with constrained sampling times

The optimal linear regulator with constrained sampling times is formulated, the existence of an optimal control law is proved, and an efficient search algorithm is developed. The search algorithm is then used to compute the control for a second-order system. The resulting sampling criterion is shown to be optimal, and provides a basis for evaluating periodic and arbitrary aperiodic sampling criteria.
Effect of epinephrine-liberated pancreatic substance on uptake of alpha amino-isobutyric acid by isolated perfused rat liver

Abstract The effluent from an isolated perfused pancreas infused with epinephrine (75 mg/min) contains some substance, not insulin, which, when infused into isolated rat liver caused increased uptake of alpha aminoisobutyric acid and increased release of glucose by the liver. The action of this substance on the liver closely resembles that of glucagon and it is proposed that the substance released from the pancreas is indeed glucagon.
Dynamic Instability of Arteries: Effects of Perivascular Tissue

To accomplish their physiological function, arteries have to remain patent under physiological loads, exhibit sufficient mechanical strength, and be capable of preserving their configuration with a sufficient reserve of safety. The latter requirement means that an artery has to be a mechanically stable structure. Among possible patterns of loss of stability is a global beam-like instability of arterial segments of sufficiently large length/diameter ratio. There are data from in vitro experiments that showed that a straight arterial segment can buckle under appropriate combinations of internal pressure and longitudinal stretch ratio and a few mathematical models were addresses to predict this phenomenon (cf. [1]). Conclusions from these studies were extended to explain the origin of arterial tortuosity observed in vivo that might be associated with serious arterial disorders such as atherosclerosis and hypertension. However, in the living organism arteries are subjected to periodic pressure, and therefore data from static experiments and conclusions from mathematical models using the static criterion for instability, namely the occurrence of bifurcation of equilibrium configuration termed as buckling, cannot be directly related to the response of arteries in vivo. A mathematical model for studying dynamic stability of arteries subjected to a longitudinal extension and a periodic pressure was proposed recently [2]. The dynamic criterion for instability was used, based on analyzing the small transverse vibrations of the vessel considered as a straight beam. Though generalization of the model to include the effect of perivascular tissue was discussed, no analysis had been performed in [2]. The objective of this study is to build a predictive model for examining mechanical stability of relatively long arterial segments subjected to a periodic pressure and longitudinal stretch with an account for the effects of perivascular tissue. The occurrence of instability is interpreted as a plausible cause of certain vascular disorders.Copyright © 2009 by ASME
Dynamic gains from North American free trade in an equilibrium model of the current account

Abstract The benefits of economic integration in North America are explored by quantifying the gains that the two small open economies of the region can obtain from free trade in financial assets as a vehicle to smooth consumption. Numerical simulations of a stochastic intertemporal equilibrium model are used to estimate the effects of free financial asset trading on economic activity and welfare. The results suggest that in Mexico, where business cycles have been larger and access to world markets has been more limited, free asset trading would produce more benefits that in Canada, where the risk of business cycles is smaller.
The Polyelectrolyte Behavior of Actin Filaments: A 25Mg NMR Study†

Under physiological conditions, filamentous actin (F-actin) is a polyanionic protein filament. Key features of the behavior of F-actin are shared with other well-characterized polyelectrolytes, in particular, duplex DNA. For example, the bundle formation of F-actin by polyvalent cations, including divalent metal ions such as Mg2+, has been proposed to be a natural consequence of the polyelectrolyte nature of actin filaments [Tang and Janmey (1996) J. Biol. Chem. 271, 8556-8563]. This recently proposed model also suggests that weak interactions between F-actin and Mg2+ ions reflect a nonspecific trapping of counterions in the electric field surrounding F-actin due to its polyelectrolyte nature. To test this hypothesis, we have performed 25Mg NMR measurements in F-actin solutions. Based on the NMR data, we estimate that the rotational correlation times of Mg2+ are independent of the overall rotational dynamics of the actin filaments. Moreover, competitive binding experiments demonstrate a facile displacement of F-actin-bound Mg2+ by Co(NH3)63+. At higher Co(NH3)63+ concentrations, a fraction of the magnesium ions are trapped as actin filaments aggregate. ATP also competes effectively with actin filaments for binding to Mg2+. These results support the hypothesis that magnesium ions bind loosely and nonspecifically to actin filaments, and thus show a behavior typical of counterions in polyelectrolyte solutions. The observed features mimic to some extent the well-documented behavior of counterions in DNA solutions.
Shock-wave compression of x-cut quartz as determined by electrical response measurements

Abstract The mechanical response of x -cut quartz in the vicinity of the Hugoniot elastic limit is determined from measurements of the piezoelectric current from samples impact loaded from 26 to 130 kbar. The Hugoniot elastic limit is determined to be 60 −1·5 +3 kbar at a compression of 0·066 −0·002 +0·004 This Hugoniot elastic limit corresponds to a shear strength of 5·5 per cent of the C 44 shear modulus. For stresses well above the Hugoniot elastic limit the electrical current measurements show that the material exhibits a substantial reduction of shear strength. The pressure derivative of the bulk modulus is determined to be 4·5, substantially less than the ultrasonic value. The experimental records show evidence for a time delay for reduction of shear strength which varies from about 10 −7 sec immediately above the 60 kbar Hugoniot elastic limit to about 10 −8 sec for stresses well above the Hugoniot elastic limit. The measurements also show stress relaxation below the Hugoniot elastic limit between 40 and 60 kbar.
How to Express Production Amplitudes in Exceptional Regions

A study is made for representations of a production amplitude in exceptional regions inside the physical region. We find that a complete set of independent invariant variables is not sufficient to describe production processes involving more than five external particles, in the exceptional regions. Our result not only influences kinematic singularities as well as the meaning of analyticity of production amplitudes, but also provides a guideline for proposing models and for fitting data. An approach, related to some of these problems, is suggested so that particle distributions for inclusive reactions can be studied with the multi-Regge expansions for all coupling schemes (configuration diagrams).
Compositional Dependence of the Coexisting Pyroxene Iron-Magnesium Distribution Coefficient

Iron-magnesium distribution coefficients for coexisting ortho- and clinopyroxene in 22 amphibolites from the New Jersey Precambrian Highlands range from 1.40 to 1.90. No systematic areal variation of the distribution coefficient is discernable within a 700 mi2 area. The distribution coefficient is, however, systematically related to pyroxene composition. The distribution coefficient tends to increase with increasing pyroxene weight % FeO (Fe as FeO) and decrease with increasing MgO and Al2O3. Data from other workers indicates that the distribution coefficient versus pyroxene composition trends found in the Highlands amphibolites are also present in both igneous and metamorphic rock suites from several other areas. Possible influence of pyroxene CaO on the distribution coefficient is also indicated. The Highlands amphibolite type trends are, however, directly opposite to those previously reported for Australian granulites. Both types of trends are apparently valid since both are present in at least one instance in metamorphic rocks from a relatively small area. The causes for the development of the two types of trends are imperfectly understood. Data presented indicates, however, that the New Jersey amphibolite type trends are apparently more characteristic of Fe-poor pyroxenes, whereas, the Australian granulite type trends are more characteristic of Fe-rich pyroxenes.
The Role of Ownership in Managing Interfirm Opportunism: A Dyadic Study

We extend research on transaction cost theory that shows that vertical integration enables firms to protect their investments in exchange relationships better than market mechanisms. However, extant research finds ownership to exacerbate, rather than limit, exchange partner opportunism. Hence, the purpose of this study is to investigate conditions under which ownership can be effective for constraining an exchange partner's opportunism. Using matched dyadic data for 296 hotel brands, we conduct multi-level hierarchical linear modeling and identify conditions under which common ownership limits hotel opportunism. Findings indicate that ownership can limit hotel opportunism when brand headquarters can easily monitor the hotel's activities.
Managing the broken capsule.

Purpose of review Posterior capsular rupture is a common complication of cataract extraction surgery. Prompt management of anterior and posterior capsular tears may prevent associated complications or need for subsequent procedural intervention. Recent findings When tears develop in the anterior capsule, novel techniques allow predictable rescue of a capsulorhexis, preventing radial extension to the posterior capsule. Several case series now describe techniques and outcomes of posterior assisted levitation techniques for a dislocated nucleus. Triamcinolone staining of the vitreous improves visualization and removal of vitreous in the anterior segment following capsular rupture. Recently published studies further describe the increased risks of endophthalmitis and retinal detachment following capsular tears. Summary Several techniques may prove beneficial in the intraoperative management of an anterior capsular tear, a dislocated nucleus, or vitreous loss.
ARACHIS HYPOGAEA. AERIAL FLOWER AND SUBTERRANEAN FRUIT

No PLANT of comparable interest to man has received less botanical attention in recent decades than the peanut, Arachis hypogaea L. The peanut is one of the principal economic plants of tropical and warm temperate rqgions of the world. It has been cultivated for nearly four centuries in West Africa, the East Indies, India, China, and Japan, and for a much longer time in its native continent, South America. From early post-Columbian times the mystifying geocarpic habit of Arachis was described, usually erroneously, by European travelers and herbalists. It confused eighteenth and nineteenth century systematists until Bentham (1859, 1865 ) corrected their and his own earlier errors. Despite this, the old morphological errors still permeate recent texts (Stanford, 1934; Rather, 1942) and reference works (Small, 1933; Bailey, 1924, (1938); Corbett in Bailey, 1944).
Catalytic mechanism of S-ribosylhomocysteinase: ionization state of active-site residues.

S-Ribosylhomocysteinase (LuxS) catalyzes the cleavage of the thioether linkage in S-ribosylhomocysteine (SRH) to produce homocysteine (Hcys) and 4,5-dihydroxy-2,3-pentanedione (DPD), the precursor of type II bacterial autoinducer (AI-2). The proposed catalytic mechanism involves two consecutive ribose carbonyl migration steps via an intramolecular redox reaction and a subsequent β-elimination step, all catalyzed by a divalent metal ion (e.g., Fe2+ or Co2+) and two general acids/bases in the active site. Absorption and EPR spectroscopic studies were performed with both wild-type and various mutant forms of LuxS under a wide range of pH conditions. The studies revealed a pKa of 10.4 for the metal-bound water. The pKa value of Cys-83 was determined to be <6 by 13C−1H HSQC NMR experiments with [3-13C]cysteine-labeled Zn2+-substituted Escherichia coli LuxS. The active form of LuxS contains a metal-bound water and a thiolate ion at Cys-83, consistent with the proposed roles of the metal ion (Lewis acid) and Cys...