bluuebunny/crossref_metadata_2025 huggingface dataset:
Contraceptive prevalence and continuation: a longitudinal analysis of traditional and other method users in the Philippines
Authors: Schwartz J. Brad , Flieger Wilhelm
Published: October 2011

Contraceptive prevalence rates and estimates of continuation rates are derived from unique longitudinal data on post-partum behaviour collected in the Cebu region of the Philippines. Continuation rates vary by base-line and time-varying socioeconomic characteristics for certain contraceptive methods and for using no contraception. Calendar rhythm users have a much lower relative continuation rate than has been found in cross-sectional samples. For women who use a contraceptive method, breast-feeding does not appear to influence contraceptive continuation, but for those who use no methods, breast-feeding appears to substitute for other forms of contraception. Profiles by socioeconomic characteristics of those who continue to use each type of contraceptive method and who use no method could be used to direct family planning programmes towards population sub-groups. The results suggest that for women wishing to postpone a pregnancy, a family planning programme aimed at the young and less educated could effectively increase contraceptive use and continuation.
Contraceptive method change among rural Sri Lankan women
Authors: Tsui Amy Ong , Thapa Shyam , Hamill David , de Silva Victor
Published: October 2011

Patterns of contraceptive method change and their association with reproductive motivation and contraceptive failure are examined using data from a 1986 survey of family planning behaviour of rural Sinhalese married women aged 15–44 in seventeen districts of Sri Lanka. A notable degree of rationality in contraceptive method changes occurs with family formation. The attempt to control unwanted fertility leads to more efficacious use of contraception, including traditional methods. Some methodological improvements to the analysis of contraceptive switching are indicated. Implications of the findings for programmatic emphasis on permanent versus non-permanent modern methods are discussed.
Double Alfvén waves
Authors: WEBB G. M. , HU Q. , DASGUPTA B. , ZANK G. P.
Published: October 2011

Double Alfvén wave solutions of the magnetohydrodynamic equations in which the physical variables (the gas density ρ, fluid velocity u, gas pressure p, and magnetic field induction B) depend only on two independent wave phases ϕ1(x,t) and ϕ2(x,t) are obtained. The integrals for the double Alfvén wave are the same as for simple waves, namely, the gas pressure, magnetic pressure, and group velocity of the wave are constant. Compatibility conditions on the evolution of the magnetic field B due to changes in ϕ1 and ϕ2, as well as constraints due to Gauss's law ∇ · B = 0 are discussed. The magnetic field lines and hodographs of B in which the tip of the magnetic field B moves on the sphere |B| = B = const. are used to delineate the physical characteristics of the wave. Hamilton's equations for the simple Alfvén wave with wave normal n(ϕ), and with magnetic induction B(ϕ) in which ϕ is the wave phase, are obtained by using the Frenet–Serret equations for curves x=X(ϕ) in differential geometry. The use of differential geometry of 2D surfaces in a 3D Euclidean space to describe double Alfvén waves is briefly discussed.
Assessing market-based conservation governance approaches: a socio-economic profile of Indonesian markets for wild birds
Authors: Jepson Paul , Ladle Richard J. , Sujatnika
Published: October 2011

One of the most difficult situations for conservation is where state capacity to regulate is weak, major corporate organizations are absent, and the population does not have a strong culture of wildlife conservation. All these apply to the hugely popular urban Indonesian pastime of keeping wild songbirds, thought to be responsible for rolling local extinctions of several native species. In such situations the introduction of a voluntary, market-based approach could interact with regulation to create new and more effective approaches to reducing the negative conservation impacts of the associated trade. Here we assess the potential of such an approach through an in-depth analysis of the socio-economic and cultural aspects of bird keeping. We project that overall the pastime contributes USD 78.8 million to the economies of the six cities surveyed, supporting a range of associated small-scale rural and urban livelihoods relating to the production of cages and collection of live bird food. Finally, we describe five general bird-breeding models with the capacity to scale up the production of captive-bred birds that may substitute for wild-caught conspecifics. Based on this information we argue that a market-based policy instrument that is capable of shifting bird-keeping trends from wild-caught birds to captive-bred alternatives would align easily with macro-policy agendas in Indonesia relating to pro-poor growth and the creation of more and better jobs. Such a policy instrument could provide exciting opportunities for conservationists to engage the interest and support of non-conservation sectors in Indonesia in efforts to conserve diminishing populations of wild birds.
The development of young Chinese children's morphological awareness: The role of semantic relatedness and morpheme type
Authors: HAO MEILING , CHEN XI , DRONJIC VEDRAN , SHU HUA , ANDERSON RICHARD C.
Published: October 2011

The research reported in this paper investigated the effects of semantic relatedness of words (closely related vs. distantly related) and morpheme type (free morpheme vs. bound morpheme) on young Chinese children's homophone awareness, an aspect of morphological awareness, in two experiments. The first experiment was a cross-sectional study including 39 children in a beginning kindergarten class, 39 children in an intermediate kindergarten class, and 36 children in a senior kindergarten class. The second experiment was a 7-month longitudinal study involving 43 first graders and 50 second graders at the beginning of the study. In both experiments, the children judged whether orally presented words shared the same morpheme or contained homophonous morphemes. The results suggest that homophone awareness emerges in Chinese children in the kindergarten years. Children's morpheme identification is facilitated by the semantic proximity of words that share a morpheme, and awareness of free morphemes is developed before that of bound morphemes. Furthermore, although semantic relatedness is the most prominent factor in kindergarten, its effect varies as a function of morpheme type in the early primary grades. Our research sheds light on the developmental course of morphological awareness and the factors that influence it.
Acoustic and perceptual measurements of prosody production on the profiling elements of prosodic systems in children by children with autism spectrum disorders
Authors: DIEHL JOSHUA JOHN , PAUL RHEA
Published: October 2011

Prosody production atypicalities are a feature of autism spectrum disorders (ASDs), but behavioral measures of performance have failed to provide detail on the properties of these deficits. We used acoustic measures of prosody to compare children with ASDs to age-matched groups with learning disabilities and typically developing peers. Overall, the group with ASD had longer utterance durations on multiple subtests on a test of prosodic abilities, and both the ASD and learning disabilities groups had higher pitch ranges and pitch variance than the typically developing group on one subtest. Acoustic differences were present even when the prosody was used correctly. These findings represent differences in the fine details of the acoustic output beyond its functional interpretation inbothclinical groups.
STOIC AUTONOMY
Authors: Cooper John M.
Published: October 2011

As it is currently understood, the notion of autonomy, both as
something that belongs to human beings and human nature, as such,
and also as the source or basis of morality (that is, duty), is
bound up inextricably with the philosophy of Kant. The term
“autonomy” itself derives from classical Greek, where
(at least in surviving texts) it was applied primarily or even
exclusively in a political context, to civic communities possessing
independent legislative and self-governing authority. The term was
taken up again in Renaissance and early modern times with similar
political applications, but was applied also in ecclesiastical disputes
about the independence of reformed churches from the former authority in
religious matters of the church of the Roman popes. Kant's innovation
consisted in conceiving of (finite) individual rational persons, as such,
as lawgivers or legislators to themselves, and to all rational beings (or
rather to all that are not perfect and holy wills), for their individual
modes of behavior. For Kant, rational beings possess a power of
legislating for themselves individually, according to which they each
set their own personal ends and subject that selection, and their pursuit
of the ends in question, to a universal principle, which is expressed in
Kant's categorical imperative. The categorical imperative
requires that one set one's own ends only within a framework that
would warrant acceptance by all other such beings.
Epigenetic mechanisms elicited by nutrition in early life
Authors: Canani Roberto Berni , Di Costanzo Margherita , Leone Ludovica , Bedogni Giorgio , Brambilla Paolo , Cianfarani Stefano , Nobili Valerio , Pietrobelli Angelo , Agostoni Carlo
Published: October 2011

A growing number of studies focusing on the developmental origin of health and disease hypothesis have identified links among early nutrition, epigenetic processes and diseases also in later life. Different epigenetic mechanisms are elicited by dietary factors in early critical developmental ages that are able to affect the susceptibility to several diseases in adulthood. The studies here reviewed suggest that maternal and neonatal diet may have long-lasting effects in the development of non-communicable chronic adulthood diseases, in particular the components of the so-called metabolic syndrome, such as insulin resistance, type 2 diabetes, obesity, dyslipidaemia, hypertension, and CVD. Both maternal under- and over-nutrition may regulate the expression of genes involved in lipid and carbohydrate metabolism. Early postnatal nutrition may also represent a vital determinant of adult health by making an impact on the development and function of gut microbiota. An inadequate gut microbiota composition and function in early life seems to account for the deviant programming of later immunity and overall health status. In this regard probiotics, which have the potential to restore the intestinal microbiota balance, may be effective in preventing the development of chronic immune-mediated diseases. More recently, the epigenetic mechanisms elicited by probiotics through the production of SCFA are hypothesised to be the key to understand how they mediate their numerous health-promoting effects from the gut to the peripheral tissues.
A fast ethanol assay to detect seed deterioration
Authors: Kodde Jan , Buckley Wayne T. , de Groot Corine C. , Retiere Marie , Viquez Zamora Ana Marcela , Groot Steven P.C.
Published: October 2011

The most common way to test seed quality is to use a simple and reliable but time- and space-consuming germination test. In this paper we present a fast and simple method to analyse cabbage seed deterioration by measuring ethanol production from partially imbibed seeds. The method uses a modified breath analyser and is simple compared to gas chromatographic or enzymatic procedures. A modified method using elevated temperatures (40°C instead of 20°C) shortened the assay time and improved its sensitivity. The analysis showed an inverse correlation between ethanol production and seed quality (e.g. the final percentages or speed of germination and the number of normal seedlings). The increase in ethanol production was observed when cabbage seeds were deteriorated by storage under ambient conditions or hot water treatments, both of which reduced the number of normal seedlings. Premature seeds produced more ethanol upon imbibition than mature seeds. Ethanol production occurred simultaneously with oxygen consumption, indicating that lack of oxygen is not the major trigger for ethanol production.
STRUCTURE AND FLORISTICS OF THE ARBOREAL COMPONENT OF A DYSTROPHIC CERRADÃO AND COMPARISON WITH OTHER CERRADÕES IN CENTRAL BRAZIL
Authors: Araújo G. M. , Nascimento A. R. T. , Lopes S. F. , Rodrigues R. F. , Ratter J. A.
Published: October 2011

This study describes the structure of the arboreal plant community in a cerradão fragment located at the Serra de Caldas Novas State Park, Goiás, central Brazil. It also compares the collected data with information from 10 other cerradão sites on dystrophic and mesotrophic soils. All trees of 4.77 cm or more diameter at breast height, in twenty-five 20 m × 20 m plots, were surveyed. Soil samples were analysed to determine the availability of nutrients. The vegetation had a discontinuous canopy, with a high density of small and medium-sized trees, and the soil was classified as dystrophic according to nutrient availability. Under ordination using Detrended Correspondence Analysis, species characteristic of the study site, such as Sclerolobium paniculatum and Emmotum nitens, were positioned in the central portion, while cosmopolitan species formed distinct groups, separated along the two axes. The community showed a low level of similarity in comparison to cerradões reported in the literature in other parts of Brazil, having more than 50% similarity only with three geographically close sites.
SYSTEMATIC AND ECOLOGICAL SIGNIFICANCE OF SEED COAT MORPHOLOGY IN SOUTH AFRICAN CAMPANULACEAE SENSU STRICTO
Authors: Cupido C. N. , Eddie W. M. M. , Tiedt L. R.
Published: October 2011

The seed coat morphology of 50 species of Campanulaceae sensu stricto, representing all 10 South African genera, was studied by scanning electron microscopy to gauge its usefulness in the diagnosis of genera or to support clades. Possible correlations with life form (annual, herbaceous and woody perennial) and ecological requirements such as fire response, rainfall requirements, bedrock and soil preferences, as well as habitat (e.g. fynbos, strandveld, renosterveld, grassland and karoo), were also investigated. Patterns of variation are described and interpreted as conforming to two seed coat types: reticulate (Type 1) and striate/wavy (Type 2). Type 1 seeds are further divided into eight subtypes. Some general trends emerged; for example, Type 1 seeds occur in all major clades of wahlenbergioids, Type 1A with a smooth coarsely reticulate surface being predominant in fynbos taxa, all of which are woody perennials. Several of the Type 1 seeds, together with Type 2 seeds, also occur in species with wider ecological amplitude, for example in karoo, strandveld or montane grasslands. In Siphocodon there is remarkable disparity in seed type between species. These variations in seed type generally appear to accord with current knowledge of climatic changes and soil evolution during the Tertiary of South Africa, and may be useful indicators of generic emergence and mosaic speciation in the major lineages of wahlenbergioids. However, it was concluded that seed coat types do not correlate closely enough with specific ecological requirements or life forms to be of unequivocal predictive value. Also, apart from Merciera and Treichelia, they are of limited use as a diagnostic character for genera, but are useful for distinguishing species.
Getting on the Board: The Presence of Women in Political Science Journal Editorial Positions
Authors: Stegmaier Mary , Palmer Barbara , van Assendelft Laura
Published: October 2011

Although the overall representation of women in the field of political science has increased gradually over the last several decades, most gains are being achieved at junior levels. When considering the status of women in the profession, it is instructive to incorporate information on the presence of women in editorial positions at top-ranked political science journals. Our 2010 snapshot of women editors in the top 50 journals in the field finds that on average, women are reasonably well represented in editorial positions in proportion to the ranks they hold in the profession overall and at PhD-granting institutions; however, substantial variation exists across journals. Our discussion of the role-model effect and the gatekeeping power of editors suggests that greater inclusion of women and others who bring different perspectives to research could result in a more vibrant range of research topics and methodological approaches published in a journal.
A Cultural Theory of Politics
Authors: Swedlow Brendon
Published: October 2011

Many political scientists first learned of anthropologist Mary Douglas's cultural theory (CT) through Aaron Wildavsky's APSA presidential address (Wildavsky 1987), in which he sought to explain the value of this theoretical approach for political science. Since then, much additional work has been done to develop CT as an ambitious general theory of politics.
Leading the Way to Compromise? Cultural Theory and Climate Change Opinion
Authors: Jones Michael D.
Published: October 2011

Climate change is easily one of the most contentious policy problems facing the United States. A majority of climate scientists agree that the earth has warmed over the last 100 years and that human-made greenhouse gasses are the cause (e.g., Doran and Zimmerman 2009; IPCC 2007; Oreskes 2004, but also see Bray 2010), yet a nontrivial portion of the US population diverges sharply from this dominant scientific position (see, for example, Jenkins-Smith, Herron, and Silva 2010, 41–45; Leiserowitz 2006; Nisbet and Myers 2007). Why? Past research usually points to the public's lack of climate change knowledge (e.g., Kellstedt, Zahran, and Vedlitz 2008), finds that media over report the views of climate change skeptics in a misplaced quest for “balanced” reporting (e.g., Boykoff and Boykoff 2007, but see Swedlow and Wildavsky 1995), or the public simply take cues from opinion leaders whom they trust (e.g., Malka, Krosnick, and Langer 2009). This article moves beyond the predominant concern with climate change knowledge, messaging structures, and cue taking in past research, and shifts the focus to characteristics intrinsic to the individual. The research presented here assesses the extent that the cultural theory (CT) developed by Mary Douglas, Aaron Wildavsky, and others (see, e.g., Schwarz and Thompson 1990; Thompson, Ellis, and Wildavsky 1990) can help political scientists understand why so many Americans do not align themselves with the majority of scientists and can help policy makers broker compromises on climate change policy.
How to Test Cultural Theory: Suggestions for Future Research
Authors: Verweij Marco , Luan Shenghua , Nowacki Mark
Published: October 2011

This symposium highlighted the relevance of the cultural theory (CT) pioneered by anthropologists Mary Douglas, Steve Rayner, and Michael Thompson and political scientists Aaron Wildavsky and Richard Ellis for explaining political phenomena. In this concluding article, we suggest ways in which CT can be further tested and developed. First, we describe how the theory has been applied thus far and some of the achievements of these applications. Then, we examine some of the challenges revealed by this research. Finally, we discuss ways of applying CT that promise to help meet these challenges. These methods include nesting case studies and combining case study and survey research, simulations, experiments, and approaches from social neuroscience.
Understanding Process Tracing
Authors: Collier David
Published: October 2011

Process tracing is a fundamental tool of qualitative analysis. This method is often invoked by scholars who carry out within-case analysis based on qualitative data, yet frequently it is neither adequately understood nor rigorously applied. This deficit motivates this article, which offers a new framework for carrying out process tracing. The reformulation integrates discussions of process tracing and causal-process observations, gives greater attention to description as a key contribution, and emphasizes the causal sequence in which process-tracing observations can be situated. In the current period of major innovation inquantitativetools for causal inference, this reformulation is part of a wider, parallel effort to achieve greater systematization ofqualitativemethods. A key point here is that these methods can add inferential leverage that is often lacking in quantitative analysis. This article is accompanied by online teaching exercises, focused on four examples from American politics, two from comparative politics, three from international relations, and one from public health/epidemiology.
Aage Clausen
Authors: Baum Lawrence , Weisberg Herbert , Slotnick Elliot
Published: October 2011

Aage Clausen, professor emeritus in the Department of Political Science at Ohio State University, died in January 2011 at the age of 78. He was an extraordinary person who made major contributions as a scholar and teacher and he was a remarkable individual who was much beloved as a colleague and friend.
George Rabinowitz
Authors: Jacoby William G.
Published: October 2011

The political science discipline lost one of its sharpest intellects and many of us lost a cherished dear friend when George Rabinowitz passed away, on March 18, 2011. George's death was entirely unexpected. He suffered a sudden cardiac arrest in Trondheim, Norway, where he was on leave from the University of North Carolina, Chapel Hill with a research fellowship.
Overweight among children decreased, but obesity prevalence remained high among women in South Africa, 1999–2005
Authors: Kruger Herculina S , Steyn Nelia P , Swart Elizabeth C , Maunder Eleni MW , Nel Johanna H , Moeng Lynn , Labadarios Demetre
Published: October 2011

Objective

The aim of the present study was to assess anthropometric status in South African children and women in 2005 in order to document temporal trends in selected anthropometric parameters.

Design

Heights and weights were measured in a cross-sectional study of children aged 1–9 years and women aged 16–35 years. The WHO reference values and BMI cut-off points were used to determine weight status.

Setting

South Africa, representative sample based on census data.

Subjects

Children (n2157) and women (n2403).

Results

Stunting was the most common nutritional disorder affecting 21·7 % of children in 1999 and 20·7 % in 2005. The difference was not statistically significant. Underweight prevalence remained unchanged, affecting 8·1 % of children, whereas wasting affected 5·8 % of children nationally, a significant increase from 4·3 % of children in 1999. Rural children were most severely affected. According to the international BMI cut-off points for overweight and obesity, 10 % of children nationally were classified as overweight and 4 % as obese. The national prevalence of overweight and obesity combined for women was 51·5 %. The prevalence of overweight in children based on weight-for-heightZ-score did not change significantly (8·0 % to 6·8 %,P= 0·138), but the combined overweight/obesity prevalence based on BMI cut-off points (17·1 % to 14·0 %,P= 0·02) decreased significantly from 1999 to 2005.

Conclusions

The double burden of undernutrition in children and overweight among women is evident in South Africa and getting worse due to increased childhood wasting combined with a high prevalence of obesity among urban women, indicating a need for urgent intervention.
Report urges research on climate remediation
Authors: Showstack Randy
Published: October 2011

The U.S. federal government should initiate a coordinated research program on climate remediation so that such measures—defined as intentional actions to counter climate effects of past greenhouse gas emissions on the atmosphere—could be modeled and evaluated, according to a task force of the Bipartisan Policy Center, a Washington, D. C., think tank. During a 4 October briefing to release the report, task force members said that some climate remediation measures, which also have been referred to as geoengineering, may need to be considered in an emergency if the climate system undergoes rapid change or experiences a tipping point that presents severe threats. The report by the center's Task Force on Climate Remediation Research pointedly does not recommend deployment of climate remediation technologies, noting that “far more research is needed to understand the potential impacts, risks, and costs associated with specific technologies.” In addition, the task force argues that climate remediation measures should not be considered as a substitute for controlling risk through climate mitigation measures.
Study suggests Arctic sea ice loss not irreversible
Authors: Balcerak Ernie
Published: October 2011

The Arctic has been losing sea ice as Earth's climate warms, and some studies have suggested that the Arctic could reach a tipping point, beyond which ice would not recover even if global temperatures cooled down again. However, a new study byArmour et al. that uses a state‐of‐the‐art atmosphere‐ocean global climate model found no evidence of such irreversibility. In their simulations, the researchers increased atmospheric carbon dioxide levels until Arctic sea ice disappeared year‐round and then watched what happened as global temperatures were then decreased. They found that sea ice steadily recovered as global temperatures dropped. An implication of this result is that future sea ice loss will occur only as long as global temperatures continue to rise. (Geophysical Research Letters, doi:10.1029/2011GL048739, 2011)
UV solar irradiance low during recent solar minimum
Authors: Balcerak Ernie
Published: October 2011

Solar irradiance, which varies with the 11‐year solar cycle and on longer time scales, can affect temperatures and winds in the atmosphere, influencing Earth's climate. As the Sun currently wakes up from a period of low sunspot activity, researchers want to know how irradiance during the recent solar minimum compares to historical levels. In addition to understanding the total received power, it is important to know how various spectral bands behave, in particular, the ultraviolet, which causes heating and winds in the stratosphere. Lockwood analyzed solar ultraviolet spectral irradiance data from May 2003 to August 2005 from both the Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) instrument on board the Upper Atmosphere Research Satellite (UARS) and the Solar Stellar Irradiance Comparison Experiment (SOLSTICE) instrument on the Solar Radiation and Climate Experiment (SORCE) satellite. Using several different methods to intercalibrate the data, he developed a data composite that can be used to determine differences between the recent solar minimum and previous minima. The author found that solar irradiance during the recent sunspot minimum has been especially low. (Journal of Geophysical Research‐Atmospheres, doi:10.1029/2010JD014746, 2011)
Refractivity estimation from sea clutter: An invited review
Authors: Karimian Ali , Yardim Caglar , Gerstoft Peter , Hodgkiss William S. , Barrios Amalia E.
Published: October 2011

Non‐standard radio wave propagation in the atmosphere is caused by anomalous changes of the atmospheric refractivity index. In recent years, refractivity from clutter (RFC) has been an active field of research to complement traditional ways of measuring the refractivity profile in maritime environments which rely on direct sensing of the environmental parameters. Higher temporal and spatial resolution of the refractivity profile, together with a lower cost and convenience of operations have been the promising factors that brought RFC under consideration. Presented is an overview of the basic concepts, research and achievements in the field of RFC. Topics that require more attention in future studies also are discussed.
SRP-35, a newly identified protein of the skeletal muscle sarcoplasmic reticulum, is a retinol dehydrogenase
Authors: Treves Susan , Thurnheer Raphael , Mosca Barbara , Vukcevic Mirko , Bergamelli Leda , Voltan Rebecca , Oberhauser Vitus , Ronjat Michel , Csernoch Laszlo , Szentesi Peter , Zorzato Francesco
Published: October 2011

In the present study we provide evidence that SRP-35, a protein we identified in rabbit skeletal muscle sarcoplasmic reticulum, is an all-trans-retinol dehydrogenase. Analysis of the primary structure and tryptic digestion revealed that its N-terminus encompasses a short hydrophobic sequence bound to the sarcoplasmic reticulum membrane, whereas its C-terminal catalytic domain faces the myoplasm. SRP-35 is also expressed in liver and adipocytes, where it appears in the post-microsomal supernatant; however, in skeletal muscle, SRP-35 is enriched in the longitudinal sarcoplasmic reticulum. Sequence comparison predicts that SRP-35 is a short-chain dehydrogenase/reductase belonging to the DHRS7C [dehydrogenase/reductase (short-chain dehydrogenase/reductase family) member 7C] subfamily. Retinol is the substrate of SRP-35, since its transient overexpression leads to an increased production of all-trans-retinaldehyde. Transfection of C2C12 myotubes with a fusion protein encoding SRP-35–EYFP (enhanced yellow fluorescent protein) causes a decrease of the maximal Ca2+ released via RyR (ryanodine receptor) activation induced by KCl or 4-chloro-m-chresol. The latter result could be mimicked by the addition of retinoic acid to the C2C12 cell tissue culture medium, a treatment which caused a significant reduction of RyR1 expression. We propose that in skeletal muscle SRP-35 is involved in the generation of all-trans-retinaldehyde and may play an important role in the generation of intracellular signals linking Ca2+ release (i.e. muscle activity) to metabolism.
Effect of short- and long-term portal hypertension on adrenergic, nitrergic and sensory functioning in rat mesenteric artery
Authors: Sastre Esther , Balfagón Gloria , Revuelta-López Elena , Aller Maria-Ángeles , Nava Maria-Paz , Arias Jaime , Blanco-Rivero Javier
Published: October 2011

In the present study, we analysed possible alterations in adrenergic, nitrergic and sensory functioning in mesenteric arteries from rats at 1 and 21 months after partial portal vein ligation, and the mechanisms involved in these alterations, if any. For this purpose, we analysed the vasoconstrictor response to EFS (electrical field stimulation) and the effect of the α-antagonist phentolamine, the NOS (nitric oxide synthase) inhibitor L-NAME (NG-nitro-L-arginine methyl ester) and the CGRP (calcitonin gene-related peptide) receptor antagonist CGRP-(8–37) in mesenteric segments from ST (short-term; 1 month) and LT (long-term; 21 months) SO (sham-operated) and pre-hepatic PH (portal hypertensive) rats. The vasomotor responses to NA (noradrenaline), the NO donor DEA-NO (diethylamine NONOate) and CGRP were analysed. NA, NO and CGRP releases were measured. Phospho-nNOS (neuronal NOS) expression was studied. The vasoconstrictor response to EFS was decreased in STPH animals. Phentolamine decreased this vasoconstrictor response more strongly in SO animals. Both L-NAME and CGRP-(8–37) increased vasoconstrictor response to EFS more strongly in PH than SO segments. PH did not modify vasomotor responses to NA, DEA-NO or CGRP, but it decreased NA release while increasing those of NO and CGRP. Phospho-nNOS expression was increased by PH. In LTPH, no differences were observed in vasoconstrictor response to EFS, vasomotor responses or neurotransmitter release when compared with age-matched SO animals. In conclusion, the mesenteric innervation may participate in the development of the characteristic hyperdynamic circulation observed in STPH through the joint action of decreased adrenergic influence, and increased nitrergic and sensory innervations influences. The participation of each innervation normalizes under conditions of LTPH.
Impact of Overweight on Effectiveness of Treatment with Human Growth Hormone in Growth Hormone Deficient Children: Analysis of German KIGS Data
Authors: Reinehr T. , Bechtold-Dalla Pozza S. , Bettendorf M. , Doerr H.-G. , Gohlke B. , Hauffa B. , Kaspers S. , Land C. , Mehls O. , Schwab K.-O. , Stahnke N. , Ranke M. ,   on behalf of the German KIGS Study Board
Published: October 2011

We hypothesized that overweight children with growth hormone deficiency (GHD) demonstrate a lower response to growth hormone (GH) as a result of a misclassification since obesity is associated with lower GH peaks in stimulation tests.

Anthropometric data, response, and responsiveness to GH in the first year of treatment were compared in 1.712 prepubertal children with GHD from the German KIGS database according to BMI (underweight=group A, normal weight=group B, overweight=group C) (median age: group A, B, C: 7.3, 7.28, and 8.4 years).

Maximum GH levels to tests (median: group A, B, C: 5.8, 5.8, and 4.0 µg/ml) were significantly lower in group C. IGF-I SDS levels were not different between the groups. Growth velocity in the first year of GH treatment was significantly lower in the underweight cohort (median: group A, B, C: 8.2, 8.8, and 9.0 cm/yr), while the gain in height was not different between groups. The difference between observed and predicted growth velocity expressed as Studentized residuals was not significantly different between groups. Separating the 164 overweight children into obese children (BMI>97th centile; n=71) and moderate overweight children (BMI>90th to 97th centile, n=93) demonstrated no significant difference in any parameter.

Overweight prepubertal children with idiopathic GHD demonstrated similar levels of responsiveness to GH treatment compared to normal weight children. Furthermore, the IGF-I levels were low in overweight children. Therefore, a misclassification of GHD in overweight prepubertal children within the KIGS database seems unlikely. The first year growth prediction models can be applied to overweight and obese GHD children.
The cathode-fall of low-pressure hydrogen discharges: Absolute spectral emission and model
Authors: Jelenković B. M. , Phelps A. V.
Published: October 2011

Absolute excitation probabilities from very low to moderate-current hydrogen discharges in parallel-plane geometry are measured and used to test models. Relative emission data are obtained for the Hα line, the H2 (a3Σ → b3Π) near-UV continuum, and the H2 (G1Σ→B1Πu+) band at pressures of 0.5 and 2 Torr, a 1.05 cm gap, and voltages from 300 to 900 V. Electron behavior is traced using the first negative (A2Σg → X2Πu, ν″ = 0 → ν′ = 0) band of N2+ by adding 2% N2. Relative measurements of Hα, H2 near-UV, and N2 1st negative emission are placed on a absolute scale by normalization to published measurements and Boltzmann calculations of electron excitation. Emission probabilities calculated using a multi-beam kinetics model for the electrons, H+, H2+, H3+, H−, H, and H2 are compared with the calibrated experiments. Fast H atoms are calculated to produce Hα excitation that is comparable with that of electrons. The calculated emission intensities for Hα and H2 near-UV continuum are within a factor of three of the absolute measurements for a range of 5000:1 in current and 4:1 in hydrogen pressure. Calculations at 2 Torr show that most of the space charge electric field responsible for the cathode fall is produced by H3+ ions.
Effects of trapping and finite temperature in a relativistic degenerate plasma
Authors: Shah H. A. , Masood W. , Qureshi M. N. S. , Tsintsadze N. L.
Published: October 2011

In the present work, we have undertaken, for the first time, investigation on the effect of trapping on the formation of solitary structures in relativistic degenerate plasmas. Such plasmas have been observed in dense astrophysical objects, and in laboratory these may result due to the interaction of intense lasers with matter. We have used the relativistic Fermi-Dirac distribution to describe the dynamics of the degenerate trapped electrons by solving the kinetic equation. The Sagdeev potential approach has been employed to obtain the arbitrary amplitude solitary structures both when the plasma has been considered cold and when small temperature effects have been taken into account. The theoretical results obtained have been analyzed numerically for different parameter values, and the results have been presented graphically.
Pseudopotentials of the particles interactions in complex plasmas
Authors: Ramazanov T. S. , Moldabekov Zh. A. , Dzhumagulova K. N. , Muratov M. M.
Published: October 2011

This article discusses the effective interaction potentials in a complex dusty plasma. The interaction of electrons with atoms and the interaction between dusty particles are studied by the method of the dielectric response function. In the effective interaction, potential between electron and atom the quantum effects of diffraction were taken into account. On the curve of the interaction potential between dust particles under certain conditions the oscillations can be observed.
Diffusion and stochastic heating of a dust cloud in tokamak edge plasmas
Authors: Marmolino C. , Bacharis M. , Allen J. E. , de Angelis U. , Willis C.
Published: October 2011

The diffusion due to collisions with ions of a cloud of nano-meter dust particles in the region of the scrape-off-layer (SOL) of a tokamak is considered and it is shown that for the conditions in the Frascati tokamak upgrade, the cloud can expand to reach the SOL limit in very short times without ablating. The conditions for stochastic heating of the cloud and acceleration of a larger particle to hyper-velocities, taking into account the effect of decreasing dust density in the cloud, are established.
Barriers in the transition to global chaos in collisionless magnetic reconnection. II. Field line spectroscopy
Authors: Borgogno D. , Grasso D. , Pegoraro F. , Schep T. J.
Published: October 2011

The transitional phase from local to global chaos in the magnetic field of a reconnecting current layer is investigated. The identification of the ridges in the field of the finite time Lyapunov exponent as barriers to the field line motion is carried out adopting the technique of field line spectroscopy to analyze the radial position of a field line while it winds its way through partial stochastic layers and to compare the frequencies of the field line motion with the corresponding frequencies of the distinguished hyperbolic field lines that are the nonlinear generalizations of linear X-lines.
The ion kinetic D’Angelo mode
Authors: Chibisov D. V. , Mikhailenko V. S. , Stepanov K. N.
Published: October 2011

An extension of hydrodynamic D’Angelo mode of inhomogeneous sheared plasma flow along the magnetic field into the short wavelength range, where the hydrodynamic treatment is not valid, has been considered. We find that D’Angelo mode in this wavelength range is excited by inverse ion Landau damping and is a shear flow driven ion-kinetic mode.
Enhancements of extreme ultraviolet emission using prepulsed Sn laser-produced plasmas for advanced lithography applications
Authors: Freeman J. R. , Harilal S. S. , Hassanein A.
Published: October 2011

Laser-produced plasmas (LPP) from Sn targets are seriously considered to be the light source for extreme ultraviolet (EUV) next generation lithography, and optimization of such a source will lead to improved efficiency and reduced cost of ownership of the entire lithography system. We investigated the role of reheating a prepulsed plasma and its effect on EUV conversion efficiency (CE). A 6 ns, 1.06 μm Nd:yttrium aluminum garnet laser was used to generate the initial plasma that was then reheated by a 40 ns, 10.6 μm CO2 laser to generate enhanced EUV emission from a planar Sn target. The effects of prepulsed laser intensity and delay timings between the prepulsed and the pumping pulse were investigated to find the optimal pre-plasma conditions before the pumping pulse. The initial optimization of these parameters resulted in 25% increase in CE from the tin LPP. The cause of increased EUV emission was identified from EUV emission spectra and ion signal data.
Membrane-integrated microfluidic device for high-resolution live cell imaging
Authors: Epshteyn Alla A. , Maher Steven , Taylor Amy J. , Holton Angela B. , Borenstein Jeffrey T. , Cuiffi Joseph D.
Published: October 2011

The design and fabrication of a membrane-integrated microfluidic cell culture device (five layers,≤500 μm total thickness) developed for high resolution microscopy is reported here. The multi-layer device was constructed to enable membrane separated cell culture for tissue mimetic in vitro model applications and pharmacodynamic evaluation studies. The microdevice was developed via a unique combination of low profile fluidic interconnect design, substrate transfer methodology, and wet silane bonding. To demonstrate the unique high resolution imaging capability of this device, we used oil immersion microscopy to image stained nuclei and mitochondria in primary hepatocytes adhered to the incorporated membrane
Calculating dispersion interactions using maximally localized Wannier functions
Authors: Andrinopoulos Lampros , Hine Nicholas D. M. , Mostofi Arash A.
Published: October 2011

We investigate a recently developed approach [P. L. Silvestrelli, Phys. Rev. Lett. 100, 053002 (2008)10.1103/PhysRevLett.100.053002; J. Phys. Chem. A 113, 5224 (2009)] that uses maximally localized Wannier functions to evaluate the van der Waals contribution to the total energy of a system calculated with density-functional theory. We test it on a set of atomic and molecular dimers of increasing complexity (argon, methane, ethene, benzene, phthalocyanine, and copper phthalocyanine) and demonstrate that the method, as originally proposed, has a number of shortcomings that hamper its predictive power. In order to overcome these problems, we have developed and implemented a number of improvements to the method and show that these modifications give rise to calculated binding energies and equilibrium geometries that are in closer agreement to results of quantum-chemical coupled-cluster calculations.
Vector potential photoelectron microscopy
Authors: Browning R.
Published: October 2011

A new class of electron microscope has been developed for the chemical microanalysis of a wide range of real world samples using photoelectron spectroscopy. Highly structured, three-dimensional samples, such as fiber mats and fracture surfaces can be imaged, as well as insulators and magnetic materials. The new microscope uses the vector potential field from a solenoid magnet as a spatial reference for imaging. A prototype instrument has demonstrated imaging of uncoated silk, magnetic steel wool, and micron-sized single strand tungsten wires.
Simulations of light induced processes in water based on ab initio path integrals molecular dynamics. I. Photoabsorption
Authors: Svoboda Ondřej , Ončák Milan , Slavíček Petr
Published: October 2011

We have performed large-scale simulations of UV absorption spectra of water clusters (monomer to octamer) using a combination of ab initio path-integral molecular dynamics with reflection principle. The aim of the present work is four-fold: (1) To explore the transition from isolated molecules to bulk water from the perspective of UV photoabsorption. (2) To investigate quantum nuclear and thermal effects on the shape of the water UV spectra. (3) To make an assessment of the density functional theory functionals to be used for water excited states. (4) To check the applicability of the QM/MM schemes for a description of the UV absorption. Within the path integral molecular dynamics (PIMD)/reflection principle approach both the thermal and quantum vibrational effects including anharmonicities are accounted for. We demonstrate that shape of the spectra is primarily controlled by the nuclear quantum effects. The excited states and transition characteristics of the water clusters were calculated with the time-dependent density functional theory and equation-of-motion coupled clusters singles and doubles methods. Based on our benchmark calculations considering the whole UV spectrum we argue that the BHandHLYP method performs best among the 6 functionals tested (B3LYP, BHandHLYP, BNL, CAM-B3LYP, LC-ωPBE, and M06HF). We observe a gradual blueshift of the maximum of the first absorption peak with the increasing cluster size. The UV absorption spectrum for the finite size clusters (i.e., the peak centers, peak widths, and photoabsorption cross section) essentially converges into the corresponding bulk water spectrum. The effect of distant molecules accounted for within the polarizable continuum model is shown to be almost negligible. Using the natural transition orbitals we demonstrate that the first absorption band is formed by localized excitations while the second band includes delocalized excited states. Consequently, the QM/MM electrostatic embedding scheme can only be used for the modeling of the low energy part of the spectrum.
Electric field polarization in conventional density functional theory: From quasilinear to two-dimensional and three-dimensional extended systems
Authors: Kirtman Bernard , Lacivita Valentina , Dovesi Roberto , Reis Heribert
Published: October 2011

The large overshoot in (hyper)polarizabilities of quasilinear (1D) chains calculated by applying density functional theory with conventional functionals is investigated for several 2D and 3D extended systems. These systems include arrays of molecular hydrogen chains, as well as 2D coronene-type structures and LiF in 1D, 2D, and 3D. Contrary to a recently proposed model it is found that the overshoot persists in all of these cases. A simple explanation is provided by an analysis of the field-induced charges for molecular hydrogen, which shows an excessive buildup at the chain ends regardless of where the chain is located within the 2D and 3D array.
Entanglement of polar symmetric top molecules as candidate qubits
Authors: Wei Qi , Kais Sabre , Friedrich Bretislav , Herschbach Dudley
Published: October 2011

Proposals for quantum computing using rotational states of polar molecules as qubits have previously considered only diatomic molecules. For these the Stark effect is second-order, so a sizable external electric field is required to produce the requisite dipole moments in the laboratory frame. Here we consider use of polar symmetric top molecules. These offer advantages resulting from a first-order Stark effect, which renders the effective dipole moments nearly independent of the field strength. That permits use of much lower external field strengths for addressing sites. Moreover, for a particular choice of qubits, the electric dipole interactions become isomorphous with NMR systems for which many techniques enhancing logic gate operations have been developed. Also inviting is the wider chemical scope, since many symmetric top organic molecules provide options for auxiliary storage qubits in spin and hyperfine structure or in internal rotation states.
Melnikov’s criteria, parametric control of chaos, and stationary chaos occurrence in systems with asymmetric potential subjected to multiscale type excitation
Authors: Kwuimy C. A. Kitio , Nataraj C. , Litak G.
Published: October 2011

We consider the problems of chaos and parametric control in nonlinear systems under an asymmetric potential subjected to a multiscale type excitation. The lower bound line for horseshoes chaos is analyzed using the Melnikov’s criterion for a transition to permanent or transient nonperiodic motions, complement by the fractal or regular shape of the basin of attraction. Numerical simulations based on the basins of attraction, bifurcation diagrams, Poincaré sections, Lyapunov exponents, and phase portraits are used to show how stationary dissipative chaos occurs in the system. Our attention is focussed on the effects of the asymmetric potential term and the driven frequency. It is shown that the threshold amplitude |γc| of the excitation decreases for small values of the driven frequency ω and increases for large values of ω. This threshold value decreases with the asymmetric parameter α and becomes constant for sufficiently large values of α. γc has its maximum value for asymmetric load in comparison with the symmetric load. Finally, we apply the Melnikov theorem to the controlled system to explore the gain control parameter dependencies.