bluuebunny/crossref_metadata_2025 huggingface dataset:
Palaeontinidae (Insecta: Hemiptera: Cicadomorpha) from the Upper Jurassic Solnhofen Limestone of Germany and their phylogenetic significance
Authors: WANG BO , ZHANG HAICHUN , WAPPLER TORSTEN , RUST JES
Published: January 2010

The Palaeontinidae (Insecta: Cicadomorpha) from the Upper Jurassic Solnhofen Limestone of Bavaria are revised. The diagnostic characters for three monotypic generaEocicadaOppenheim, 1888,ProlystraOppenheim, 1888 andArchipsycheHandlirsch, 1906 are reassessed based on newly discovered material.Beloptesis gigantea(Weyenbergh, 1874),B. oppenheimiHandlirsch, 1906,Limacodites mesozoicusHandlirsch, 1906, andProtopsyche braueriHandlirsch, 1906 are considered to be junior synonyms ofProlystra lithographicaOppenheim, 1888.Eocicada lameereiHandlirsch, 1908 is a junior synonym ofE. microcephalaOppenheim, 1888. A key to the species of Solnhofen Palaeontinidae is presented. Solnhofen Palaeontinidae and most Cretaceous Palaeontinidae most probably form a monophyletic group based on the following characters: costal area narrow, vein RA branching from stem R basally, vein ScP not fused with vein RA, clavus much reduced and hindwing smaller. Furthermore, Solnhofen Palaeontinidae are probably basal to Cretaceous Palaeontinidae by the mesonotum lacking distinct longitudinal carinae. A fast succession from early to more derived Palaeontinidae took place during Late Jurassic times. Early Palaeontinidae declined sharply in the Late Jurassic, probably owing to the rise of newly evolved insectivorous animals like early birds and mammals. Late Palaeontinidae with better flight ability survived and became a dominant insect group during latest Jurassic times.
Numerical and experimental studies of the rolling sphere wake
Authors: STEWART B. E. , THOMPSON M. C. , LEWEKE T. , HOURIGAN K.
Published: January 2010

A numerical and experimental investigation is reported for the flow around a rolling sphere when moving adjacent to a plane wall. The dimensionless rotation rate of the sphere is varied from forward to reversed rolling and the resulting wake modes are found to be strongly dependent on the value of this parameter. Results are reported for the Reynolds number range 100 < Re < 350, which has been shown to capture the unsteady transitions in the wake. Over this range of Reynolds number, both steady and unsteady wake modes are observed. As the sphere undergoes forward rolling, the wake displays similarities to the flow behind an isolated sphere in a free stream. As the Reynolds number of the flow increases, hairpin vortices form and are shed over the surface of the sphere. However, for cases with reversed rotation, the wake takes the form of two distinct streamwise vortices that form around the sides of the body. These streamwise structures in the wake undergo a transition to a new unsteady mode as the Reynolds number increases. During the evolution of this unsteady mode, the streamwise vortices form an out-of-phase spiral pair. Four primary wake modes are identified and a very good qualitative agreement is observed between the numerical and experimental results. The numerical simulations also reveal the existence of an additional unsteady mode that is found to be unstable to small perturbations in the flow.
Rayleigh–Taylor instability in a viscoelastic binary fluid
Authors: BOFFETTA GUIDO , MAZZINO ANDREA , MUSACCHIO STEFANO , VOZELLA LARA
Published: January 2010

The effects of polymer additives on Rayleigh–Taylor (RT) instability of immiscible fluids is investigated using the Oldroyd-B viscoelastic model. Analytic results obtained exploiting the phase-field approach show that in polymer solution the growth rate of the instability speeds up with elasticity (but remains slower than in the pure solvent case). Numerical simulations of the viscoelastic binary fluid model confirm this picture.
Slip velocity over a perforated or patchy surface
Authors: POZRIKIDIS C.
Published: January 2010

Shear flow over a solid surface containing perforations or patches of zero shear stress is discussed with a view to evaluating the slip velocity. In both cases, the functional dependence of the slip velocity on the solid fraction of the surface strongly depends on the surface geometry, and a universal law cannot be established. Numerical results for flow over a plate with circular or square perforations or patches of zero shear stress, and flow over a plate consisting of separated square or circular tiles corroborate the assertion.
Horizontal mixing of quasi-uniform straight compound channel flows
Authors: STOCCHINO ALESSANDRO , BROCCHINI MAURIZIO
Published: January 2010

The generation and evolution of large-scale vortices with vertical axis (macro-vortices) in a straight compound channel under quasi-uniform flow conditions is investigated. We discuss possible similarities and clear differences with free shear layer flows induced by the meeting of shallow streams of different speeds. An experimental investigation based on particle image velocimetry (PIV) measurements of free-surface velocities forms the basis for an analysis of both the specific features of macro-vortices and of the related mean flow characteristics. Dynamical properties strongly depend on the ratio rh between the main channel flow depth (h*mc) and the floodplain depth (h*fp), and three flow classes can be identified. ‘Shallow flows’ (rh > 3) are dominated by strong shearing and large macro-vortices populating the transition region between the main channel and the floodplains. The mean streamwise velocity induced in ‘intermediate flows’ (2 ≤ rh ≤ 3) is characterized by a dip in the transition region, while it closely resembles that occurring in a rectangular channel in the case of ‘deep flows’ (rh < 2). For both the latter cases the shear in the transition region decreases and the macro-vortices are also generated in the wall boundary layer of the floodplains. The typical size of the quasi-two-dimensional macro-vortices, generated at the transition region, is found to be independent of the streamwise coordinate. This and the non-monotonic behaviour of the mean streamwise velocity suggest that in straight compound channels the topographic forcing is so dominant that conceptual models interpreting these flows as free shear layers may largely fail to describe the physics of compound channels flows.
Variation of axial and radial temperature in an expanded thermal plasma jet
Authors: BORA B. , KAKATI M. , DAS A. K.
Published: January 2010

The distribution of temperature in an expanded thermal plasma jet is investigated by modified Langmuir probes. The validation of classical probe theory in the entire experimental chamber pressure range of 10–100 mbar is thoroughly established before the measurements. The average temperature of the plasma jet at the nozzle exit was also measured by calorimetric estimation of total heat loss from the plasma upstream of that point. A correlation is made using simple analytical expression in between the average temperature measured from the heat loss data and the centerline temperature at the nozzle exit measured by Langmuir probe. The profile parameter n for the radial distribution of temperature in a plasma jet is calculated for different operating current and gas flow rates.
Ion acoustic double layers forming behind irradiated solid objects in streaming plasmas
Authors: MILOCH W. J. , REKAA V. L. , PÉCSELI H. L. , TRULSEN J.
Published: January 2010

Small solid metallic objects in relative motion to thermal plasmas are studied by numerical simulations. We analyze supersonic motions, where a distinctive ion wake is formed behind obstacles. At these plasma drift velocities, ions enter the wake predominantly due to deflections by the electric field in the sheath around the obstacle. By irradiating the back side of the object by ultraviolet (UV) light, we can induce also an enhanced photo-electron population there. The resulting charge distribution gives rise to a pronounced local potential and plasma density well behind the object. This potential variation has the form of a three-dimensional ion acoustic double layer, containing also an ion phase space vortex. The analysis is supported also by one-dimensional numerical simulations to illustrate the importance of boundary conditions, Dirichlet and von Neumann conditions in particular.
Levitated dust particles subjected to plasma jet
Authors: TICOŞ C. M. , JEPU I. , LUNGU C. P. , CHIRU P. , ZAROSCHI V. , LUNGU A. M.
Published: January 2010

A dust crystal levitated in the sheath of a radio-frequency plasma is subjected to a pulsed plasma jet expelled from a minicoaxial gun. The dust particles, initially found at rest and self-organized in a 3-D structure, are dragged by the plasma jet for a short distance and come to rest when the action of the jet terminates. The trajectories of the microparticles are tracked in vertical and horizontal planes with a high-speed camera. From in situ observations of dust particle dynamics the dust acceleration is compared to numerical simulations.
Excitation of longitudinal waves in a degenerate isotropic quantum plasma
Authors: TSINTSADZE LEVAN N. , TSINTSADZE NODAR L.
Published: January 2010

A dispersion equation, which describes the interaction of low-density electron beam with a degenerate electron quantum plasma, is derived and examined for some interesting cases. In addition to the instabilities similar to those for classical plasma, due to the quantum effect, a new type of instability is found. Growth rates of these new modes, which are purely quantum, are obtained. Furthermore, the excitation of Bogolyubov's type of spectrum by a strong electric field is discussed.
Ideology, affect, and socialization in language shift and revitalization: The experiences of adults learning Gaelic in the Western Isles of Scotland
Authors: McEWAN-FUJITA EMILY
Published: January 2010

The intertwined role of language ideologies and affect in language shift and revitalization can be understood by taking a language socialization perspective on local micro-level interaction between adult Gaelic learners and fluent Gaelic-English bilinguals. Seven adults living in the Western Isles were interviewed about their efforts to learn and speak Scottish Gaelic, a minority language spoken by 1–2% of Scotland’s population. Their negative affective stances in describing their interactions with local Gaelic-English bilinguals indicate that they were being socialized into an ideology of local Gaelic-English sociolinguistic boundaries: an “etiquette of accommodation” to English speakers and wariness about public Gaelic speaking. This socialized combination of ideology and negative affect reduces opportunities for Gaelic speaking, hindering both Gaelic learners’ efforts to become fluent speakers and their potential contribution to language revitalization. In contrast, however, the interviewees described “sociolinguistic mentors” who socialized them into a more inclusive vision of Gaelic speaking laden with positive affect.1
Orientation workspace analysis of a special class of the Stewart–Gough parallel manipulators
Authors: Cao Yi , Huang Zhen , Zhou Hui , Ji Weixi
Published: January 2010

The workspace of a robotic manipulator is a very important issue and design criteria in the context of optimum design of robots, especially for parallel manipulators. Though, considerable research has been paid to the investigations of the three-dimensional (3D) constant orientation workspace or position workspace of parallel manipulators, very few works exist on the topic of the 3D orientation workspace, especially the nonsingular orientation workspace and practical orientation workspace. This paper addresses the orientation workspace analysis of a special class of the Stewart–Gough parallel manipulators in which the moving and base platforms are two similar semisymmetrical hexagons. Based on the half-angle transformation, a polynomial expression of 13 degree that represents the orientation singularity locus of this special class of the Stewart–Gough parallel manipulators at a fixed position is derived and graphical representations of the orientation singularity locus of this special class of the Stewart–Gough manipulators are illustrated with examples to demonstrate the result. Exploiting this half-angle transformation and the inverse kinematics solution of this special class of the Stewart–Gough parallel manipulators, a discretization method is proposed for computing the orientation workspace of this special class of the Stewart–Gough parallel manipulators taking limitations of active and passive joints and the link interference all into consideration. Based on this algorithm, this paper also presents a new discretization method for computing the nonsingular orientation workspace of this class of the manipulators, which not only can satisfy all the kinematics demand of this class of the manipulators but also can guarantee the manipulator is nonsingular in the whole orientation workspace, and the practical orientation workspace of this class of the manipulators, which not only can guarantee the manipulator is nonsingular and will never encounter any kinematic interference but also can satisfy the demand of the orientation workspace with a regular shape in practical application, respectively. Examples of a 6/6-SPS Stewart–Gough parallel manipulator of this special class are given to demonstrate these theoretical results.
Outdoor mapping and localization using satellite images
Authors: Dogruer C. U. , Koku A. B. , Dolen M.
Published: January 2010

Recently, satellite images of most urban settings has become available on the internet. In this study, a novel mapping and global localization approach, which uses these images, is proposed for outdoor mobile robots operating in urban environment. The mapping of large-scale outdoor environments is done by employing the satellite images acquired by remote sensing technology, and then a map-based approach, that is, Monte Carlo localization is used for localization. The novelty of proposed method is that it uses standard equipment present on almost all autonomous robots and satellite images thus it acts as an alternative to GPS data in urban environments. Extensive field tests are presented to demonstrate the effectiveness of proposed approach.
A linear optimal tracker designed for omnidirectional vehicle dynamics linearized based on kinematic equations
Authors: Tu Kuo-Yang
Published: January 2010

It is difficult to design controllers for the complicated dynamics of omnidirectional vehicles steered by multiple wheels with distributed traction force. In this paper, the dynamic model of a three-wheel omnidirectional vehicle, which is linearized to simplify controller design, is developed. The conditions of making its dynamics linear are derived first. Then, a strategy of planning wheel velocities to satisfy these conditions is proposed. Consequently, three-wheel omnidirectional vehicle can be easily treated by classical linear control theories. Finally, a linear optimal tracker is designed to control the omnidirectional vehicle for desired movement trajectories. In particular, the dynamic model includes the motors installed in the three-wheel omnidirectional vehicle, making it a practical model. Three kinds of vehicle trajectories illustrate the planning of wheel trajectories for linearizing the vehicle dynamics, and simulations demonstrate the performance of the linear optimal tracker. In addition, experimental results of a practical three-wheel omnidirectional vehicle are also included.
Pair correlation for fractional parts of αn2
Authors: HEATH–BROWN D. R.
Published: January 2010

It was proved by Weyl [8] in 1916 that the sequence of values of αn2 is uniformly distributed modulo 1, for any fixed real irrational α. Indeed this result covered sequences αnd for any fixed positive integer exponent d. However Weyl's work leaves open a number of questions concerning the finer distribution of these sequences. It has been conjectured by Rudnick, Sarnak and Zaharescu [6] that the fractional parts of αn2 will have a Poisson distribution provided firstly that α is “Diophantine”, and secondly that if a/q is any convergent to α then the square-free part of q is q1+o(1). Here one says that α is Diophantine if one has
(1.1)
for every rational number a/q and any fixed ϵ > 0. In particular every real irrational algebraic number is Diophantine. One would predict that there are Diophantine numbers α for which the sequence of convergents pn/qn contains infinitely many squares amongst the qn. If true, this would show that the second condition is independent of the first. Indeed one would expect to find such α with bounded partial quotients.
On the Hausdorff dimension of the Julia set of a regularly growing entire function
Authors: BERGWEILER WALTER , KARPIŃSKA BOGUSŁAWA
Published: January 2010

We show that if the growth of a transcendental entire function f is sufficiently regular, then the Julia set and the escaping set of f have Hausdorff dimension 2.
Hypoxic-ischaemic injury of the neonatal brain
Authors: Wyatt JS
Published: January 2010

Despite advances in obstetric and neonatal care, hypoxia-ischaemia remains as probably the commonest cause of severe disabling brain injury which occurs in the perinatal period. Although for the population as a whole, congenital brain abnormality and early fetal events are the most frequent antecedent of permanent neurodevelopmental disability, perinatal brain injury is an important and potentially preventable cause of severe and permanent handicap in both developed and developing countries.
Fluorescence in situ hybridization (FISH) in prenatal diagnosis
Authors: Yaron Yuval , Ebrahim Salah , Kramer Ralph L , Johnson Mark P , Evans Mark I
Published: January 2010

Currently, the gold standard for prenatal detection of chromosomal abnormalities relies on traditional cytogenetic analysis of banded meta-phase chromosome spreads of cultured cells obtained by amniocentesis, chorionic villous sampling, or fetal blood sampling. Using this technique, a wide range of chromosomal aneu-ploidies and structural aberrations such as translocations, inversions and deletions may be diagnosed with a high degree of accuracy. Unfortunately, this technique has several disadvantages: it is labour intensive, requiring highly trained analysts, and most importantly, it can only be applied to cells undergoing mitosis. Hence the.need for cell culture which may require several days, such that the complete analysis is usually obtained after 7 to 14 days. Thus, there is a need to develop faster methods for prenatal chromosomal analysis.
Preterm prelabour amniorrhexis
Authors: Carroll Stephen , Sebire Neil , Nicolaides Kypros
Published: January 2010

Preterm delivery occurs in less than 10% of pregnancies but accounts for more than 60% of all neonatal deaths. Approximately one third of preterm deliveries are associated with preterm prelabour amniorrhexis and in a high proportion of such cases the underlying cause may be ascending infection from the lower genital tract. The causes of neonatal death in pregnancies with amniorrhexis are prematurity, pulmonary hypoplasia and sepsis. In the management of pregnancies with preterm prelabour amniorrhexis it is essential to distinguish between those with and without intrauterine infection. If there is no infection at presentation it is unlikely that this will develop and in such cases there is no benefit from hospitalisation, bed rest, prophylactic tocolytics or antibiotics. The group with evidence of intrauterine infection go into spontaneous labour within a few days of amniorrhexis; in this group the main determinant for the appropriate management is the gestation at amniorrhexis.
The role of calcium channel blockers in the treatment of women with preeclampsia
Authors: Lewis R , Belfort M , Sibai B
Published: January 2010

Preeclampsia was originally known as a process whereby an unknown “toxin” was responsible for a variety of responses. While this toxin has yet to be determined, many theories have prevailed as to the appropriate therapy for this condition.

Recently, antihypertensive therapy has become increasingly regarded as an important component of the medical management of women with preeclampsia. Initially, the ideal therapy for peripartum acute hypertensive emergencies was felt to be a smooth muscle relaxant and the most commonly prescribed agent was hydralazine. This drug was felt to be beneficial because of its action on vascular smooth muscle, decreasing vasospasm. Outside of the United States diazoxide was also used for this purpose, although this drug has been replaced because of the high incidence of fetal distress. Another agent that was frequently used was α-methyldopa which was initially considered to be the treatment of choice in the treatment of patieats with moderate and severe preeclampsia. Recently, α-methyldopa has been reserved for the outpatient management of gestational hypertension, especially in women with mild preeclampsia or chronic hypertension.
The effect of epidural analgesia on labour progress and mode of delivery
Authors: Thorp James A , Nielsen Peter E
Published: January 2010

The use and method of intrapartum obstetric analgesia has remained controversial since the late 16th Century. In 1591, during the reign of James, VI, Eufame MacCalzean (a Scottish midwife) was the first to attempt pain relief during labour and childbirth. At that time, the provision of pain relief during labour was an unacceptable medical practice due mainly to religious and social objections. Because of these objections, and historical accounts that claimed the midwife had consulted with a witch during the delivery, both MacCalzean and the midwife were found guilty of witchcraft and subsequently executed.
Voltage-gated calcium channels inPleurodelesoocytes: classification, modulation and functional roles
Authors: Ouadid-Ahidouch Halima
Published: January 2010

In unfertilisedPleurodelesoocytes, two distinct types of high voltage-activated Ca2+channels are expressed: a slowly inactivating Ca2+channel and a transient one. The first is dihydropyridine-sensitive and is referred to as the L-type Ca2+channel. The transient channel is highly sensitive to Ni2+. Phosphorylation through protein kinases G and A facilitates and inhibits the L-type Ca2+channel respectively. The transient type channel is insensitive to stimulation by protein kinases (A and G). The functional expression of L-type and transient Ca2+channels is modulated by the two maturation seasons. The transient Ca2+currents are only observed during the resting season, while the L-type current is observed either alone during the breeding season or in association with the transient current during the resting season. Moreover, the current density of the L-type Ca2+channel is much greater during the breeding season than the resting season. Thus, the wide distribution of L-type Ca2+channels inPleurodelesoocytes during the two seasons suggests that the roles of these channels may be important in the regulation of the maturation process.
Theories of Power, Poverty, and Law: In Commemoration of the Contributions of Peter Bachrach
Authors: Baer Judith A.
Published: January 2010

A while ago we lost Peter Bachrach, one of the pre-eminent academic figures of the twentieth century. After he died on December 14, 2007, a group of his former students and colleagues gathered at the APSA annual meeting in Boston to celebrate his life and career. The audience included family members, “academic grandchildren,” and admirers of his work. The speakers' themes included power, poverty, activism, legal theory, and equality, and this symposium grew out of the panel. This range and variety of topics indicate the scope and depth of his impact. His 1962 APSR article, “Two Faces of Power,” co-authored with Morton Baratz, is the most frequently cited article in the history of the political science profession. Although I suspect this distinction would have amused Peter, terms like faces of power, nondecision, and deciding not to decide are familiar even to those who don't know Bachrach and Baratz's work on power (Bachrach and Baratz 1962, 1963). These writings taught scholars to listen for what is not said and look for what is not shown. That was a crucial lesson for feminist legal scholars like my classmate and fellow panelist, Elizabeth Schneider, and me.
No Escape from Ethnicity? Confessions of an Accidental CNN Pundit
Authors: Subotic Jelena
Published: January 2010

As a political scientist with expertise in human rights and the Balkans, I was invited to provide critical commentary and analysis of Kosovo's declaration of independence in February 2008 for CNN International. I offered an analysis rooted in the understanding and interpretation of international law, foreign policy, and domestic politics of Serbia and Kosovo. While I was not surprised that my analysis was not popular in Serbia—after all, I did argue that the independence of Kosovo was legitimate—I was surprised at the level of ethnic intensity and the broad-based hostile reaction to my CNN appearance in Serbia. This article first documents the harassment campaign I experienced. I then conduct textual analysis of the hate mail and online postings to offer insights about ethnicity's relation to identity, gender, and political analysis in the public sphere. I conclude by discussing how identities of researchers—as crafted by themselves and others—help define analytical tools we use in scholarly inquiry.
Assessing Student Learning Outcomes in United States Government Courses
Authors: Champney Leonard , Edleman Paul
Published: January 2010

This study employs the Solomon Four-Group Design to measure student knowledge of the United States government and student knowledge of current events at the beginning of a U.S. government course and at the end. In both areas, knowledge improves significantly. Regarding knowledge of the U.S. government, both males and females improve at similar rates, those with higher and lower GPAs improve at similar rates, and political science majors improve at similar rates to non-majors. Regarding current events, males and females improve at similar rates. However, those with higher GPAs and political science majors improve more than others.
Data Preservation through Data Archives
Authors: Albright Jeremy J. , Lyle Jared A.
Published: January 2010

Science functions best within a liberal democracy. Every hypothesis test is an expression of doubt, as it carries with it the implication that a particular presumption may be incorrect (Kruschke 1998), whereas authoritarianism punishes challenges to prescribed beliefs. Consequently, science can lead to true innovation and improvements in knowledge only when laws and social norms permit dissent.
ROBERT W. JACKMAN
Authors: Siverson Randolph M. , Stone Walter J.
Published: January 2010

Robert W. Jackman, Distinguished Professor of Political Science at the University of California, Davis, died peacefully in San Francisco on October 8, 2009, after a long, courageous struggle with pancreatic cancer.
External Reviewers; Friends or Foes? Political Science Panel Embraces Reviewers!
Authors: Wilson Graham
Published: January 2010

If it is time for an external review—or if the dean announces you are having one anyway—it almost certain that your first reaction as a department chair will be that this is bad news and that the red coats are coming! After all, at very least an external review is going to result in a considerable amount of extra work. And the review can be a moment of what a panel member who had served as a dean termed a time of “extreme danger”; a bad review can really damage a departments standing and prospects with the dean and university administration more generally. However at the 2009 Annual Meeting a distinguished group of political scientists (Evelyn Huber, Stephen Majeski, John Woolley, Michael Kraft, and Gretchen Bauer) chaired by Graham Wilson of the APSA Departmental Service Committee urged chairs to be positive. Having been on both the receiving and giving sides of the review process, panel members uniformly concluded that it can be a very positive experience for departments and their chairs.
An Exploration of Prospective Imagery: The Impact of Future Events Scale
Authors: Deeprose Catherine , Holmes Emily A.
Published: January 2010

Background: Mental imagery of the future has clear clinical importance, although little is known about intrusive, prospective imagery of personally-relevant events. Currently, no measure is available to assess this. Aims: The Impact of Future Events Scale (IFES) was created to assess the impact of intrusive, prospective, personally-relevant imagery. It was examined in relation to predictions about dysphoria. Method: To form the IFES, the IES-R (a measure of the impact of a past traumatic event on posttraumatic stress disorder symptomatology such as intrusive re-experiencing) was adapted item-by-item to assess intrusive “pre-experiencing” and imagery of specific, future events. Participants (N = 75) completed the IFES and assessments of depression, anxiety and general imagery use. Results: As predicted, the IFES significantly and positively correlated with depression scores. Analyses using subgroups of non-dysphoric and mild-dysphoric participants confirmed that the mild-dysphoric group reported significantly higher IFES scores, indicating higher levels of pre-experiencing of the future and related hyperarousal and avoidance. Conclusions: IFES provides a measure of the impact of “pre-experiencing” in the form of intrusive prospective, personally-relevant imagery, with sensitivity to group differences on the basis of depression scores. Further research is required to extend these finding into clinical depression and other psychopathological conditions.
Vitamin D deficiency is endemic in Middle Eastern sportsmen
Authors: Hamilton Bruce , Grantham Justin , Racinais Sebastien , Chalabi Hakim
Published: January 2010

Objective

While vitamin D deficiency is well recognized in Middle Eastern women as a result of cultural norms of remaining covered, Middle Eastern men are an under-reported group. Vitamin D is now known to have multiple effects, including an impact on muscle function, thereby increasing the relevance for sportsmen. The aim of the present study was to evaluate serum 25-hydroxyvitamin D (25(OH)D) levels in young male Middle Eastern athletes.

Design

Cross-sectional study.

Setting

Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar.

Subjects

Ninety-three Middle Eastern men presenting to hospital for an annual screening undertook a blood test to evaluate their vitamin D status.

Results

Ninety-one per cent of athletes were found to be deficient in 25(OH)D (serum concentration <20 ng/ml). Athletes with severe deficiencies were significantly younger than those with less marked deficiency. A subset of athletes underwent bone mineral density assessment and 59 % were shown to have at least oneZ-score less than −1; despite this, however, no athletes reported a stress fracture. There was no correlation between 25(OH)D concentration and sunlight exposure, skin coverage and skin colouring.

Conclusions

The study revealed that 25(OH)D deficiency is very common among otherwise healthy Middle Eastern male athletes. Given the potentially significant long- and short-term effects of 25(OH)D deficiency, serum 25(OH)D evaluation should be part of the routine assessment in this region.
Without order, anything goes? The prohibition of forced displacement in non-international armed conflict
Authors: Willms Jan
Published: January 2010

At first glance, merely the ‘ordering’ of displacement seems to be prohibited in non-international armed conflict. However, after interpreting Article 17(1) AP II and Rule 129(B) of the ICRC Customary Law Study with particular regard to State practice and opinio juris, the author concludes that these norms prohibit forced displacement regardless of whether it is ordered or not. On the other hand, the ICC Elements of Crimes for the crime of forced displacement under Article 8(2)(e)(viii) ICC Statute require an order. It remains to be seen whether the ICC adopts that interpretation in its jurisprudence.
Humanitarian assistance to migrants irrespective of their status – towards a non-categorical approach
Authors: Linde Thomas
Published: January 2010

Humanitarian organizations dealing with migrants have long prioritized such people according to legal and institutional categories, therefore focusing on those fleeing conflict, violence or persecution. In a departure from this tradition, it was recommended at the 30th International Conference of the Red Cross and Red Crescent that the Movement should take an inclusive approach towards addressing the humanitarian dimension of migration, irrespective of the status of the migrants of concern. This article discusses the shift towards such an approach, and how it has been implemented in the International Federation of Red Cross and Red Crescent Societies' migration policy.
Diagnostic analyses of dry intrusion and nonuniformly saturated instability during a rainfall event
Authors: Gao Shouting , Yang Shuai , Chen Bin
Published: January 2010

Using the one by one degree National Centers for Environmental Prediction final data (details of data set can be found in http://dss.ucar.edu/datasets/ds083.2/) and numerical mesoscale results simulated by the WRF model, the characteristics of dry intrusion during a heavy rainfall event in northern China are studied. Since dry intrusion is a Lagrangian feature and should be identified with the aid of trajectory calculations, in this paper this process is simulated by the Lagrangian Flexpart particle dispersion model, and the trajectories of moist and dry air parcels are depicted and traced using a Lagrangian method. It is found that the cold, dry air with high potential vorticity shows up prior to the start of precipitation and persists and extends downward to lower levels during the raining periods. As the dry, cold air from upper levels intrudes into the warm, moist sector in the lower troposphere, the two air masses with different characteristics mix causing nonuniform saturation to occur in the atmosphere. On the basis of this nonuniform saturation concept, a new Brunt‐Väisälä frequency for nonuniformly saturated moist atmospheres is derived and applied to the diagnostic study of precipitation cases. It is found to be more appropriate for depicting the instability of rainy regions than those stability indexes used in dry and moist saturated atmosphere.
A modeling investigation of canopy‐air oxygen isotopic exchange of water vapor and carbon dioxide in a soybean field
Authors: Xiao Wei , Lee Xuhui , Griffis Timothy J. , Kim Kyounghee , Welp Lisa R. , Yu Qiang
Published: January 2010

The oxygen isotopes of CO2 and H2O (18O‐CO2 and 18O‐H2O) provide unique information regarding the contribution of terrestrial vegetation to the global CO2 and H2O cycles. In this paper, a simple isotopic land surface model was used to investigate processes controlling the isotopic exchange of 18O‐H2O and 18O‐CO2 between a soybean ecosystem and the atmosphere. We included in a standard land surface model a nonsteady state theory of leaf water isotopic composition, a canopy kinetic fractionation factor, and a big‐leaf parameterization of the 18O‐CO2 isoforcing on the atmosphere. Our model simulations showed that the Péclet effect was less important than the nonsteady state effect on the temporal dynamics of the water isotopic exchange. The model reproduced the highly significant and negative correlation between relative humidity and the ecosystem‐scale 18O‐CO2 isoforcing measured with eddy covariance. But the model‐predicted isoforcing was biased high in comparison to the observations. Model sensitivity analysis suggested that the CO2 hydration efficiency must have been much lower in the leaves of soybean in field conditions than previously reported. Understanding environmental controls on the hydration efficiency and the scaling from the leaf to the canopy represents an area in need of more research.
Reversible aggregation of X-Shaped bolaamphiphiles with partially fluorinated lateral chains at the air/water interface
Authors: Nitoń Patrycja , Żywociński Andrzej , Hołyst Robert , Kieffer Robert , Tschierske Carsten , Paczesny Jan , Pociecha Damian , Górecka Ewa
Published: January 2010

New compounds from the group of partially fluorinated X-shaped bolaamphiphiles are studied. These compounds exhibit an unusual reversibility of Langmuir isotherms when compressed/decompressed up to the total collapse of the film.
Steady free-surface flow at the stern of a ship
Authors: Binder Benjamin James
Published: January 2010

New solutions for steady two-dimensional free-surface flow past a curved plate are considered here. They can be interpreted as approximations to the flow locally at the stern of a ship. Weakly nonlinear solutions are derived analytically and nonlinear solutions are computed by boundary integral equation methods. Analysis in the phase plane provides a way to determine the geometries of hulls that give rise to wave-free stern flows. These waveless flows are desirable as they reduce ship-drag.
Highly efficient pulsed power supply system with a two-stage LC generator and a step-up transformer for fast capillary discharge soft x-ray laser at shorter wavelength
Authors: Sakai Yusuke , Takahashi Shnsuke , Komatsu Takanori , Song Inho , Watanabe Masato , Hotta Eiki
Published: January 2010

Highly efficient and compact pulsed power supply system for a capillary discharge soft x-ray laser (SXRL) has been developed. The system consists of a 2.2 μF two-stage LC inversion generator, a 2:54 step-up transformer, a 3 nF water capacitor, and a discharge section with a few tens of centimeter length capillary. Adoption of the pulsed transformer in combination with the LC inversion generator enables us to use only one gap switch in the circuit for charging the water capacitor up to about 0.5 MV. Furthermore, step-up ratio of a water capacitor voltage to a LC inversion generator initial charging voltage is about 40 with energy transfer efficiency of about 50%. It also leads to good reproducibility of a capillary discharge which is necessary for lasing a SXRL stably. For the study of the possibility of lasing a SXRL at shorter wavelength in a small laboratory scale, high-density and high-temperature plasma column suitable for the laser can be generated relatively easily with this system.
Reductive half-reaction of aldehyde oxidoreductase toward acetaldehyde:Ab initioand free energy quantum mechanical/molecular mechanical calculations
Authors: Dieterich Johannes M. , Werner Hans-Joachim , Mata Ricardo A. , Metz Sebastian , Thiel Walter
Published: January 2010

Energy and free energy barriers for acetaldehyde conversion in aldehyde oxidoreductase are determined for three reaction pathways using quantum mechanical/molecular mechanical (QM/MM) calculations on the solvated enzyme. Ab initio single-point QM/MM energies are obtained at the stationary points optimized at the DFT(B3LYP)/MM level. These ab initio calculations employ local correlation treatments [LMP2 and LCCSD(T0)] in combination with augmented triple- and quadruple-zeta basis sets, and the final coupled cluster results include MP2-based corrections for basis set incompleteness and for the domain approximation. Free energy perturbation (FEP) theory is used to generate free energy profiles at the DFT(B3LYP)/MM level for the most important reaction steps by sampling along the corresponding reaction paths using molecular dynamics. The ab initio and FEP QM/MM results are combined to derive improved estimates of the free energy barriers, which differ from the corresponding DFT(B3LYP)/MM energy barriers by about 3 kcal mol−1. The present results confirm the qualitative mechanistic conclusions from a previous DFT(B3LYP)/MM study. Most favorable is a three-step Lewis base catalyzed mechanism with an initial proton transfer from the cofactor to the Glu869 residue, a subsequent nucleophilic attack that yields a tetrahedral intermediate (IM2), and a final rate-limiting hydride transfer. The competing metal center activated pathway has the same final step but needs to overcome a higher barrier in the initial step on the route to IM2. The concerted mechanism has the highest free energy barrier and can be ruled out. While confirming the qualitative mechanistic scenario proposed previously on the basis of DFT(B3LYP)/MM energy profiles, the present ab initio and FEP QM/MM calculations provide corrections to the barriers that are important when aiming at high accuracy.
Cherenkov-type diamond detectors for measurements of fast electrons in the TORE-SUPRA tokamak
Authors: Jakubowski L. , Sadowski M. J. , Zebrowski J. , Rabinski M. , Malinowski K. , Mirowski R. , Lotte Ph. , Gunn J. , Pascal J-Y. , Colledani G. , Basiuk V. , Goniche M. , Lipa M.
Published: January 2010

The paper presents a schematic design and tests of a system applicable for measurements of fast electron pulses emitted from high-temperature plasma generated inside magnetic confinement fusion machines, and particularly in the TORE-SUPRA facility. The diagnostic system based on the registration of the Cherenkov radiation induced by fast electrons within selected solid radiators is considered, and electron low-energy thresholds for different radiators are given. There are some estimates of high thermal loads, which might be deposited by intense electron beams upon parts of the diagnostic equipment within the TORE-SUPRA device. There are some proposed measures to overcome this difficulty by the selection of appropriate absorption filters and Cherenkov radiators, and particularly by the application of a fast-moving reciprocating probe. The paper describes the measuring system, its tests, as well as some results of the preliminary measurements of fast electrons within TORE-SUPRA facility.
Discrete perturbation theory for the hard-core attractive and repulsive Yukawa potentials
Authors: Torres-Arenas J. , Cervantes L. A. , Benavides A. L. , Chapela G. A. , del Río F.
Published: January 2010

In this work we apply the discrete perturbation theory [A. L. Benavides and A. Gil-Villegas, Mol. Phys. 97, 1225 (1999)] to obtain an equation of state for the case of two continuous potentials: the hard-core attractive Yukawa potential and the hard-core repulsive Yukawa potential. The main advantage of the presented equation of state is that it is an explicit analytical expression in the parameters that characterize the intermolecular interactions. With a suitable choice of their inverse screening length parameter one can model the behavior of different systems. This feature allows us to make a systematic study of the effect of the variation in the parameters on the thermodynamic properties of this system. We analyze single phase properties at different conditions of density and temperature, and vapor-liquid phase diagrams for several values of the reduced inverse screening length parameter within the interval κ∗=0.1–5.0. The theoretical predictions are compared with available and new Monte Carlo simulation data. Good agreement is found for most of the cases and better predictions are found for the long-range ones. The Yukawa potential is an example of a family of hard-core plus a tail (attractive or repulsive) function that asymptotically goes to zero as the separations between particles increase. We would expect that similar results could be found for other potentials with these characteristics.
Electromagnetic drift instabilities in high-β plasma under conditions of a field reversed configuration
Authors: Chirkov A. Yu. , Khvesyuk V. I.
Published: January 2010

Electromagnetic drift instabilities are studied in the conditions of a field reversed configuration (FRC). Dispersion equation is based on the set of Vlasov–Maxwell equations taking into account nonadiabatic responses both of ions and electrons. Considered drift instabilities are caused by density and temperature gradients. It is assumed that magnetic field of the FRC is purely poloidal. Two kinds of magnetic field nonuniformity are considered: (i) perpendicular gradient due to high β values (β is the plasma pressure/magnetic pressure) and (ii) curvature of magnetic lines. There is low frequency drift instability existing for high-β regimes. Modes of such instability can propagate transversally to the unperturbed magnetic field lines.
Note: Characterization of electrode materials for dielectric spectroscopy
Authors: Malleo D. , Nevill J. T. , van Ooyen A. , Schnakenberg U. , Lee L. P. , Morgan H.
Published: January 2010

When measuring the dielectric properties of aqueous samples, the impedance of the electrode/sample interface can limit low frequency measurements. The electrode polarization problem can be reduced by increasing the effective surface area of the electrodes. In this work, impedance spectroscopy was used to characterize and compare three different electrode surfaces that can be used to mitigate this effect: platinum black, iridium oxide, and [polypyrrole/poly(styrenesulphonate)] (PPy/PSS) conducting polymer. All three materials were directly compared with a bright platinum electrode. Equivalent circuit models were used to extract the increase in the effective surface area of the electrodes: platinum black, iridium oxide and PPy/PSS increase the effective capacitance of the electrode by factors of approximately 240, 75, and 790, respectively. The practical aspects of all electrode materials are discussed. These results suggest that iridium oxide and PPy/PSS are good alternatives to the commonly used platinum black, which is prone to mechanical damage (scratches) and is potentially toxic to cells.
Velocity distribution function of sputtered Cu atoms obtained by time resolved optical absorption spectroscopy
Authors: Kang Namjun , Oh Soo-ghee , Gaboriau Freddy , Ricard André
Published: January 2010

A new method based on time resolved optical absorption spectroscopy is proposed to determine the velocity distribution function of sputtered Cu atoms in a magnetron plasma discharge. The method consists of applying a short pulse of 1.5 μs and of recording time variations in copper atom density in off pulse at different positions (1, 2, and 3 cm) from target surface under 3–30 mTorr. The time evolution of the density is then converted into velocity distribution. We estimate that only sputtered atoms with radial velocity component lower than 0.5 km/s are detected. The average velocity of Cu atoms is evaluated as the first order moment of the velocity distribution functions. The velocity distribution functions become the more dispersive the farther from target surface. The average velocities vary in the range of 2.5–3 km/s at the vicinity of target surface whereas at 3 cm a decrease from 2.5 to 1.2 km/s is observed at 30 mTorr.
Melting of size-selected aluminum nanoclusters with 84–128 atoms
Authors: Starace Anne K. , Cao Baopeng , Judd Oscar H. , Bhattacharyya Indrani , Jarrold Martin F.
Published: January 2010

Heat capacities have been measured as a function of temperature for isolated aluminum nanoclusters with 84–128 atoms. Most clusters show a single sharp peak in the heat capacity which is attributed to a melting transition. However, there are several size regimes where additional features are observed; for clusters with 84–89 atoms the peak in the heat capacity is either broad or bimodal. For Al115+, Al116+, and Al117+ there are two well-defined peaks, and for Al126+, Al127+, and Al128+ there is a dip in the heat capacity at lower temperature than the peak. The broad or bimodal peaks for clusters with 84–89 atoms are not significantly changed by annealing to 823 K (above the melting temperature), but the dips for Al126+, Al127+, and Al128+ disappear when these clusters are annealed to 523 K (above the temperature of the dip but below the melting temperature). Both the melting temperatures and the latent heats change fairly smoothly with the cluster size in the size regime examined here. There are steps in the melting temperatures for clusters with around 100 and 117 atoms. The step at Al100+ is correlated with a substantial peak in the latent heats but the step at Al117+ correlates with a minimum. Since the latent heats are correlated with the cluster cohesive energies, the substantial peak in the latent heats at Al100+ indicates this cluster is particularly strongly bound.