bluuebunny/crossref_metadata_2025 huggingface dataset:
Feeding ecology of little tunny Euthynnus alletteratus in the central Mediterranean Sea
Authors: Falautano Manuela , Castriota Luca , Finoia Maria Grazia , Andaloro Franco
Published: July 2007

The feeding habits of Euthynnus alletteratus and its variations compared to predator size in the central Mediterranean Sea were investigated. The stomach contents of 187 specimens were analysed, ranging from 26.8 to 50.3 cm total length, caught by authorized experimental drift-nets. The difference in food items found in the stomachs was evaluated by occurrence of prey frequency, prey weight, and prey abundance; these criteria were used to calculate an index of relative importance. Fish were the dominant food detected according to all numerical indicators examined and were mainly represented by Maurolicus muelleri and larval stages of teleosts. Hyperiid amphipods, dominated by Anchylomera blossevillei and Phrosina semilunata, were well represented in terms of frequency of occurrence. Variations in the diet composition compared to fish size were observed. Comparative analysis performed on prey abundance highlighted a trend of increasing predator size-classes among prey items. The specimens of the smallest sizes ate mainly adult clupeiforms and larvae or other juvenile teleosts. As fish grew, there were increased amounts of adult teleosts, crustaceans (hyperiids and isopods) and cephalopods. Maurolicus muelleri was the most important prey for the largest specimens analysed. Significant differences among size-classes, both in prey abundance and in prey weight, were confirmed by non-parametric multivariate analysis of variance (NP-MANOVA).
Benthic richness in the Argentine continental shelf: the role of Zygochlamys patagonica (Mollusca: Bivalvia: Pectinidae) as settlement substrate
Authors: Schejter Laura , Bremec Claudia
Published: July 2007

In this study we present results on epibionts on Zygochlamys patagonica from material collected during monitoring cruises in different areas in the Argentine Sea. We update the checklist of epibionts increasing the number of taxa from 19 to 41 and considering two species closely associated with the shells. The demosponge Iophon proximum was the most frequent and abundant epibiont (% presence and coverage). Polydora sp. was registered as a parasite of Z. patagonica in shells from the Beagle Channel, but it did not infest scallops from the commercial beds. Zygochlamys patagonica shells constitute conspicuous hard substrate available for the settlement of sessile organisms. This fact leads to an increased benthic richness in the continental soft-bottom areas of the Argentine Sea, where scallop beds are located.
Molecular evidence for synonymy of the genera Moroteuthis and Onykia and identification of their paralarvae from northern Hawaiian waters
Authors: Wakabayashi Toshie , Kubodera Tsunemi , Sakai Mitsuo , Ichii Taro , Chow Seinen
Published: July 2007

It has been claimed that most squid species in the genus Onykia may be immature stages of species in the genus Moroteuthis. To evaluate the generic status of Moroteuthis and Onykia and to identify paralarvae collected in northern Hawaiian waters, we performed morphological investigation and nucleotide sequence analysis of the mitochondrial cytochrome oxidase I (COI) gene. Of 42 Onykia paralarvae (1.8–8.5 mm dorsal mantle length, DML) examined, 41 had a nucleotide sequence identical to that of M. robusta and one (designated Onykia sp. A) could not be assigned to any known Moroteuthis species. Nucleotide sequence diversity estimates based on Kimura's two-parameter distances between Onykia sp. A and Moroteuthis spp. (0.109–0.150) fell well within the range of congeneric species, suggesting that Onykia sp. A is a member of the genus Moroteuthis. Molecular data supported the conclusion that the genus Moroteuthis is a junior synonym of the genus Onykia. Morphological investigation revealed that paralarvae of O. robusta (= M. robusta) <4.0 mm DML were distinct from other Onykia paralarvae in the chromatophore pattern on the mantle. The key characters for distinguishing O. robusta paralarvae from Onykia sp. A were the number and arrangement of chromatophores on the funnel.
Assessment of decadal-scale ecological change at a deep Mid-Atlantic hydrothermal vent and reproductive time-series in the shrimp Rimicaris exoculata
Authors: Copley J.T.P. , Jorgensen P.B.K. , Sohn R.A.
Published: July 2007

This study presents a comparison of distribution and abundance of dominant megafaunal species at the TAG hydrothermal mound on the Mid-Atlantic Ridge from 1994 to 2004. A geographical information system (GIS) database was compiled from georeferenced observations of faunal abundances at 534 locations on the TAG hydrothermal mound, determined by image analysis of ROV dive footage from November 2004. These data are compared with observations from submersible dives in 1994 to assess changes in the extent and population density of aggregations of the shrimp Rimicaris exoculata at the central black smokers of TAG. The GIS database was also used to assess changes in abundance and distribution of the anemone Maractis rimicarivora by simulating the path of a biotransect conducted in 1994 and 1995. There was no evidence of a decline in the extent of shrimp aggregations at the central black smokers of TAG between 1994 and 2004. This result indicates that occasional exposure to high-intensity submersible lighting, which took place during several scientific expeditions in the intervening period, does not pose an immediate conservation threat to populations of R. exoculata. Similarly, there were no significant differences in the distribution and abundance of anemones between 1994 and 2004. These results indicate a constancy in the identity, distribution and abundance of dominant species at TAG that contrasts with other vent sites where quantitative time-series have been established. The reproductive pattern of R. exoculata was also examined by dissection and direct measurement of oocytes from females collected in September 1994 and November 2004, providing the first comparison of reproductive development in samples from different months for this species. There was no significant difference in oocyte size–frequency distributions of females collected in these samples, indicating a lack of seasonal reproduction in R. exoculata.
Acoustic signalling during courtship in the painted goby, Pomatoschistus pictus
Authors: Amorim M.C.P. , Neves A.S.M.
Published: July 2007

Gobies emit sounds during different stages of reproduction, including courtship, pre-spawning events (in the nest) and spawning. The breeding sounds of the painted goby Pomatoschistus pictus and associated courtship behaviour were recorded in captivity and described for the first time. Males emitted thump-like sounds mainly when displaying alone in the nest and produced drumming sounds outside the nest. Thumps have never been reported for other species of the genus Pomatoschistus. Thumps were short (~80 ms) very-low frequency (below 100 Hz) non-pulsed sounds, whereas drums were longer (hundreds of ms) and consisted of low frequency (~300 Hz) pulse trains. Thump characteristics varied significantly among males but also showed high within-male variability. The frequency of thump emissions and courtship behaviour (total number of courtship displays, lead and nest display) were positively correlated with male size but not with male somatic condition. Thump bursts emitted during nest displays were significantly longer than when emitted with other behaviours. These results suggest that larger males courted females more intensively, both with visual and acoustic displays, than smaller ones.
Do protozoa contribute significantly to the diet of larval fish in the Irish Sea?
Authors: de Figueiredo Gisela M. , Nash Richard D.M. , Montagnes David J.S.
Published: July 2007

This study evaluates the role of protozoa in larval fish feeding by describing protozoa in larval fish diets and testing the hypothesis that, in the Irish Sea, larval fish feed on protozoan prey at rates that potentially sustain their food requirements. Gut contents of 11 taxonomic groups of larval fish were examined, and protist prey occurred in the diet of all of them. Protozoan prey were identified, which provided an insight into their trophic role. Most of the protozoan prey were autotrophic or mixotrophic. In general, larval fish diets were constant over the spring/summer period, regardless of prey availability in the field and the composition of larval fish assemblage (taxonomy and size). A laboratory experiment on ingestion rates of flounder larvae as a function of ciliates concentration was conducted. Combined laboratory and field data showed that, in the Irish Sea, it is unlikely that ciliates are often the primary food source of flounder larvae, and, by implication, other larval fish as well. However, ciliates and other protozoa could be a substantial component of the larval fish diet, and they may potentially prevent food limitation.
Development of microsatellite markers in the razor clam Solen marginatus (Bivalvia: Solenidae)
Authors: Francisco-Candeira Marta , González-Tizón Ana , Varela Miguel A. , Martínez-Lage Andrés
Published: July 2007

Four microsatellite loci in the razor clam Solen marginatus are described. Loci were isolated from the sequences of intersimple sequence repeat (ISSR) markers and an enriched library. Detailed analysis of these sequences led to the design of eight primer pairs. Allelic variation was assessed in 20 individuals from Redondela, Spain. The genetic variation observed in the markers presented here will be useful for future studies on the population structure of Solen marginatus in the wild and for aquaculture of this species.
‘Only Religions Count in Vietnam’: Thich Tri Quang and the Vietnam War
Authors: McALLISTER JAMES
Published: July 2007

Thich Tri Quang has long been one of the most controversial actors in the history of the Vietnam War. Scholars on the right have argued that Tri Quang was in all likelihood a communist agent operating at the behest of Hanoi. Scholars on the left have argued that Tri Quang was a peaceful religious leader devoted to democracy and a rapid end to the war. This article argues that neither of these interpretations is persuasive. As American officials rightly concluded throughout the war, there was no compelling evidence to suggest that Tri Quang was a communist agent or in any way sympathetic to the goals of Hanoi or the NLF. Drawing on the extensive archival evidence of Tri Quang's conversations with American officials, it is apparent that Tri Quang was in fact strongly anti-communist and quite receptive to the use of American military power against North Vietnam and China. The main factor that led to conflict between the Buddhist movement and the Johnson administration was Tri Quang's insistence that the military regimes that followed Ngo Dinh Diem were hostile to Buddhism and incapable of leading the struggle against Communism to a successful conclusion.
An unfinished mappa mundi from late-eleventh-century Worcester
Authors: Foys Martin K.
Published: July 2007

This article discusses the unfinished mappa mundi found in Cambridge, Corpus Christi College 265, dates it to a late-eleventh-century (c. 1065–95) production in Worcester, identifying it as a nearly exact and earlier analogue of two later twelfth-century English maps of the world from the Ramsey area (Oxford, St John's College 17 and London, British Library, Harley 3667). Contained as it is in a collection of Wulfstanian materials, the Worcester map's relationship to these so-called ‘Bryhtferthian’ maps requires a rethinking of how such maps may have circulated and functioned outside of a computisitical context. The close connections between these three maps further point to a unique, late Anglo-Saxon tradition of mappae mundi thus far unrecognized.
Local properties of self-similar solutions to Smoluchowski’s coagulation equation with sum kernels
Authors: Fournier Nicolas , Laurençot Philippe
Published: July 2007

The regularity of the scaling profiles ψ to Smoluchowski’s coagulation equation is studied when the coagulation kernel K is given by K(x, y) = xλ + yλ with λ∈ (0, 1). More precisely, ψ is C1-smooth on (0,∞) and decays exponentially fast for large x. Furthermore, the singular behaviour of ψ(x) as x → 0 is identified, thus giving a rigorous proof of physical conjectures.
The implicit function theorem and multi-bump solutions of periodic partial differential equations
Authors: Magnus Robert
Published: July 2007

A modification of the implicit function theorem is advanced for cases where the continuity of the derivative fails. It is applied to a superposition principle for periodicpartial differential equations. The assumption of the principle, that there should exist a non-degenerate solution, is studied and instances of it realized using perturbation arguments and scaling. The positivity of solutions is considered.
A scaling approach to bumps and multi-bumps for nonlinear partial differential equations
Authors: Magnus Robert
Published: July 2007

The problem −Δu + F(V (εx), u) = 0 is considered in Rn. For small ε > 0, solutions are obtained that approach, as ε → 0, a linear combination of specified functions, mutually translated by O(1/ε). These are the so-called multi-bump solutions. The method involves a rescaling of the variables and the use of a modified implicit function theorem. The usual implicit function theorem is inapplicable, owing to lack of convergence of the derivative of the nonlinear Hilbert space operator, obtained after an appropriate rescaling, in the operator-norm topology. An asymptotic formula for the solution for small ε is obtained.
A few remarks on differential inclusions
Authors: Sychev M. A.
Published: July 2007

In this paper we analyse the methodology of the theory of differential inclusions. First, we emphasize that any sequence of piecewise affine functions with successive elements obtained by perturbations of preceding functions in the sets of their affinity converges strongly, together with the gradients. This gives a simple algorithm with which to construct sequences of approximate solutions that converge to exact solutions (neither the specific choice suggested by ‘the method of convex integration for Lipschitz functions’ nor Baire category methodology is required). We then suggest a functional that is defined in the set of admissible functions and measures maximal oscillations produced by sequences of admissible functions weakly convergent to a given function. This functional can be used to prove that the set of stable solutions is dense in the weak topology in the closure of the set of admissible functions either via the Baire category lemma or via a specific choice of strictly convergent sequences.

We explain how the above-mentioned methods of finding solutions to differential inclusions are connected to earlier results on weak–strong convergence, i.e. to results on stability, in the calculus of variations and in differential inclusions.

We also include information on developments in the subject in the three years after the results of this work were obtained.
Invasive meningococcal disease in children in Jerusalem
Authors: STEIN-ZAMIR C. , ABRAMSON N. , ZENTNER G. , SHOOB H. , VALINSKY L. , BLOCK C.
Published: July 2007

Neisseria meningitidisis an important cause of childhood meningitis and septicaemia. Between 1999 and 2005, 133 invasive meningococcal disease (IMD) cases occurred in Jerusalem, 112 (84·2%) of them in children aged 0–14 years. The annual incidence rate in Jerusalem was higher than the national average (2·45±0·6vs. 1·13±0·16/100 000 population,P=0·002). Most of the children (82·1%) were from low socio-economic Arab and Jewish ultra-orthodox communities; mortality was higher among Arab than Jewish children (1·3vs. 0·22/100 000 person-years,P=0·004). A cluster of 10 children with severe meningococcal sepsis (three fatalities) emerged in the winter of 2003–2004. Compared to the other 102 cases in 1999–2005 both meningococcaemia (100%vs. 51%,P=0·003) and mortality (30%vs. 6·9%,P=0·014) rates were higher. Serogroup B comprised 77·6% of the bacterial isolates. Pulsed-field gel electrophoresis showed considerable variability among cluster isolates, but significant resemblance in Arab cases throughout 1999–2005. The increased susceptibility of specific sub-populations to IMD necessitates further evaluation.
Aging, sarcopenia and the life-course
Authors: Sayer Avan Aihie , Cooper Cyrus
Published: August 2007

There is growing support for characterizing human aging from a life-course perspective, in terms of recognizing important influences operating from conception to death, and this approach provides a framework for understanding aging processes operating at the individual level. Kirkwood's disposable soma theory proposes that aging is a manifestation of imperfect somatic maintenance and repair processes. We can therefore predict that differing exposure to the determinants of somatic damage across the life-course, and variable capacity to respond in terms of repair are likely to underlie the wide variation in rates of aging between individuals.
Outcome of ligation of the persistently patent arterial duct in neonates as performed by an outreach surgical team
Authors: Sivakumar Shanmugasundaram , Lee Lleona , Tillett Angela , Wells Francis , Dunning Jon , Kelsall A Wilf
Published: August 2007

Aim

Our aim was to review the outcome of ligation of the persistently patent arterial duct in neonates as performed outside a paediatric cardiothoracic centre by an outreach surgical team.

Methods

A retrospective observational study of all ligations of the persistently patent arterial duct performed in Cambridge between January, 1988, and December, 2002.

Results

Over the period of 15 years studied, a persistently patent arterial duct was ligated in 43 neonates. The median gestational age at birth was 26 weeks, with a range from 23 to 35 weeks, and median weight at birth was 722 grams, with a range from 500 to 2100 grams. Median age at ligation, was 25 days, with a range from 10 to 89 days, and their weight was 963 grams, with a range from 568 to 2221 grams. Ligation was successful in 42 babies (98%), mortality at 30 days of 5%, and 29 of the babies (67%) surviving to be discharged from the hospital. The late deaths were due to complications of prematurity, rather than the procedure of ligation.

Conclusion

The persistently patent arterial duct can successfully be ligated by an outreach surgical team outside a paediatric cardiothoracic centre. There was an excellent 30 day survival.
Motor development in children with congenital cardiac diseases compared to their healthy peers
Authors: Bjarnason-Wehrens Birna , Dordel Sigrid , Schickendantz Sabine , Krumm Constanze , Bott Daniel , Sreeram Narayanswami , Brockmeier Konrad
Published: August 2007

Their perceptual and motor experiences determine the physical and motor development of children, and impact also on their emotional, psychosocial, and cognitive development. Our aim, therefore, was to evaluate motor development in children with congenitally malformed hearts compared to their healthy peers.

We compared 194 children, with a mean age of 10.0 years, and standard deviation of 2.7 years, representing the entire spectrum of congenital cardiac disease, to a control group of 455 healthy children, having a mean age 9.6 years, with standard deviation of 2.17 years. The bodily coordination test for children was used to examine motor development.

Of the children with congenitally malformed hearts, 26.8% showed moderate, and 31.9% had severe disturbances of motor development, compared to 16.5% and 5.5% of the control group, the p-value for these differences being less than 0.001. The mean motor quotient adjusted for age and gender was lower in the children with congenitally malformed hearts than in their healthy peers, at 79.6, with standard deviation of 18.9 as opposed to 96.6, with standard deviation of 15, this difference having a p-value of less than 0.001. Depending on the presence, and/or the degree, of residual sequels, the children with congenitally malformed hearts were divided into two subgroups, with either no or mild residual sequels, or with significant sequels. The mean motor quotient was lower in those with significant residual sequels, at 75, with standard deviation of 19.3, as opposed to 83, with standard deviation of 17.9, the p-value for this difference being less than 0.01. In both subgroups, the mean motor quotient was lower, with a p-value of less than 0.01, than in the control group.

Our findings show that children with congenitally malformed hearts have deficits in their motor development, these being found in the presence of no or mild sequels, as well as with significant residual sequels. Parental overprotection may contribute to these findings.
Validity and reliability of a calcium checklist in early elementary-school children
Authors: Marcotte Lori , Hennessy Erin , Dwyer Johanna , Hyatt Raymond R , Goldberg Jeanne P , Naumova Elena N , Economos Christina D
Published: August 2007

Objective

To create, validate and assess the reliability of a checklist to measure calcium intake in children.

Design

Calcium intakes from a checklist and parent-assisted 24-h dietary recall were compared. Checklist reliability was assessed separately.

Setting

After-school programmes in the United States.

Subjects

Forty-two children (18 males, 24 females, age = 8.0 ± 0.9 years) participated in the validation analysis and 49 children (28 males, 21 females, age = 7.5 ± 0.9 years) in the reliability analysis.

Results

No differences in mean calcium intakes were found by method or gender. The checklist correlated well with recall among girls (r= 0.65,P= 0.01) but not boys (r= −0.33,P= 0.19). Agreement over time was above 80% for most foods.

Conclusion

The calcium checklist is useful for assessing calcium intake among groups of 6–10-year-old children in settings that preclude parental assistance. More research is needed to improve accuracy among boys.
Linear programming can help identify practical solutions to improve the nutritional quality of food aid
Authors: Rambeloson Zo J , Darmon Nicole , Ferguson Elaine L
Published: August 2007

Objectives

To assess the nutritional quality of food aid delivered by food banks in France and to identify practical modifications to improve it.

Design

National-level data were collected for all food aid distributed by French food banks in 2004, and its nutrient content per 2000 kcal was estimated and compared with French recommendations for adults. Starting with the actual donation and allowing new foods into the food aid donation, linear programming was used to identify the minimum changes required in the actual donation to achieve the French recommendations.

Results

French food-bank-delivered food aid does not achieve the French recommendations for dietary fibre, ascorbic acid, vitamin D, folate, magnesium, docosahexaenoic acid, α-linolenic acid and the percentage of energy from saturated fatty acids. Linear programming analysis showed that these recommendations are achievable if more fruits, vegetables, legumes and fish were collected and less cheese, refined cereals and foods rich in fat, sugar and/or salt. In addition, new foods not previously collected are needed, particularly nuts, wholemeal bread and rapeseed oil. These changes increased the total edible weight (42%) and economic value (55%) of the food aid donation, with one-third of its edible weight coming from fruits and vegetables, one-third from staples, one-quarter from dairy products and approximately a tenth from meat/fish/eggs.

Conclusions

Important changes in the types and amounts of food collected will improve the nutritional quality of food-bank-delivered food aid in France. Such changes are recommended to improve the diets of deprived French populations.
Why do boys eat less fruit and vegetables than girls?
Authors: Bere Elling , Brug Johannes , Klepp Knut-Inge
Published: August 2007

Objective

To explore why boys eat less fruit and vegetables (F&V) than girls, using longitudinal data following pupils from the age of 12.5 to 15.5 years, including perceived accessibility, modelling, intention, preferences, self-efficacy and knowledge of recommendations as potential mediators.

Design/setting/subjects

A longitudinal study, based on data collected among the control schools within the intervention project ‘Fruits and Vegetables Make the Marks’. This sample contains 896 6th and 7th graders from 20 randomly selected elementary schools within two Norwegian counties. Questionnaires were administered in May 2002 and May 2005 (when the participants were in 9th and 10th grade in 18 secondary elementary schools).

Results

In single mediation analyses all determinants mediated parts of the gender difference, but only preferences decreased the gender difference to a level below statistical significance. Preferences alone explained 81% of the gender difference. In the multiple mediation analyses, the six mediators together explained 91% of the gender difference, but only preferences and perceived accessibility contributed uniquely to the explanation, with 25% and 10% respectively.

Conclusions

Preference appears as the strongest mediator of the difference in F&V intakes between boys and girls. Further research should explore why girls like F&V more than boys.
Molecular cell biology of KATPchannels: implications for neonatal diabetes
Authors: Smith Andrew J. , Taneja Tarvinder K. , Mankouri Jamel , Sivaprasadarao Asipu
Published: August 2007

ATP-sensitive potassium (KATP) channels play a key role in the regulation of insulin secretion by coupling glucose metabolism to the electrical activity of pancreatic β-cells. To generate an electric signal of suitable magnitude, the plasma membrane of the β-cell must contain an appropriate number of channels. An inadequate number of channels can lead to congenital hyperinsulinism, whereas an excess of channels can result in the opposite condition, neonatal diabetes. KATPchannels are made up of four subunits each of Kir6.2 and the sulphonylurea receptor (SUR1), encoded by the genesKCNJ11andABCC8, respectively. Following synthesis, the subunits must assemble into an octameric complex to be able to exit the endoplasmic reticulum and reach the plasma membrane. While this biosynthetic pathway ensures supply of channels to the cell surface, an opposite pathway, involving clathrin-mediated endocytosis, removes channels back into the cell. The balance between these two processes, perhaps in conjunction with endocytic recycling, would dictate the channel density at the cell membrane. In this review, we discuss the molecular signals that contribute to this balance, and how an imbalance could lead to a disease state such as neonatal diabetes.
Locality, environment and law: the case of town and village greens
Authors: McGillivray Donald , Holder Jane
Published: July 2007

In this paper we explore one type of commons – town and village greens – which are an important feature of the rural and, increasingly, the urban, English landscape. Greens are an ancient form of commons, but they are increasingly recognised as having contemporary significance, particularly because of their potential to act as a reservoir for natural resources and their enjoyment. They are, in other words, emerging out of a ‘feudal box’. We focus on the fact that town and village greens are recognised in law by their association with a group of people defined by their physical proximity to the land which is to be registered. Although this does not in itself constitute a community, the law requires for the registration of land as a town or village green a certain degree of organisation and self-selection and this has in the past fostered both a sense of subjective belief in ‘belonging’, as well as exclusion (the rights of local people being potentially ‘diluted’ by the use of the land by those from outside the locality). As well as helping to produce and recognise community and community identity, then, commons may simultaneously produce the conditions for disassociation and exclusion. In this context, we consider how law defines and upholds notions of locality, and also the ways in which an increasingly powerful environmental discourse might be seen to challenge the primacy given to locality as a way of defining and creating greens and, more generally, the practical effects of this on how decisions are made about preserving these spaces as ‘common’. We consider the scope of the public trust doctrine as providing an example of how law is capable of accommodating ideas of shared nature and natural resources, in this case providing a form of public ownership over natural resources. Whilst our analysis is rooted firmly in the law relating to town and village greens in England and Wales, this body of law displays certain important features more broadly applicable to a range of other types of common land, and raises more general issues about how law supports certain interests in land, often to the exclusion of others.
‘We who are not here’: law, whiteness, indigenous peoples and the promise of genetic identification
Authors: O’Connell Karen
Published: July 2007

In contemporary law, genetic technologies of the body have provided a new layer of complexity to legal determinations of racial identity. Indigenous peoples in particular are often forced to present themselves before law as invisible peoples requesting embodiment, possessing no set identity and requiring a legal determination of their status. In return for their participation in genetic research indigenous peoples have been promised, amongst other things, a reliable identification that would make them visible as indigenous before the law. This article examines genetic and non-genetic approaches to identifying indigenous peoples through a case study of Australian law and argues that while genetic technologies may have little to offer indigenous populations they do hold out the possibility of making visible to whites and white institutions their own obscured racial identity.
Low Back Pain – von der Arbeitsunfähigkeit zur Invalidität
Authors: Risi
Published: August 2007

Unspezifische Rückenschmerzen (LBP) sind so häufig, dass sie als normale Befindlichkeitsstörung angesehen werden können. Sie werden als medizinisches Problem behandelt, obwohl sie sich – vor allem was ihre Folgen anbelangt – weitgehend auf dem sozioökonomisch und kulturellen Territorium abspielen. Sie sind ein Paradebeispiel einer Medikalisierung gesellschaftlicher Probleme, womit falsche Antworten auf dringende Fragen generiert werden.
Uteriner Tumor mit keimstrang-ähnlicher Differenzierung (UTROSCT): Fallbericht und Literaturübersicht
Authors: Kunz  , Friedrich
Published: August 2007

Uterustumoren mit keimstrangähnlicher Differenzierung sind selten, betreffen prä- und postmenopausale Frauen der vierten bis sechsten Dekade, manifestieren sich mit Blutungsanomalien und meist vergrösserten Uteri, die als Uterus myomatosus fehlinterpretiert werden. Aufgrund des Anteils keimstrang-ähnlicher Elemente werden zwei Gruppen unterschieden, nämlich Tumoren mit nur fokal keimstrang-ähnlicher Differenzierung, die zu Rezidiv und Metastasierung neigen und Tumoren, welche eine überwiegende Differenzierung im Sinne von ovariellen Keimstrangtumoren zeigen und die eine gute Prognose aufweisen, weil zumeist die alleinige chirurgische Therapie zu rezidivfreiem Überleben führt. Aufgrund der Seltenheit der Tumoren existieren keine randomisierten Untersuchungen zur optimalen Therapie. Da über endometriale Stromasarkome mit niedrigem malignen Potential unter adjuvanter Therapie des Mammakarzinoms mit Tamoxifen berichtet wurde, ist anzunehmen, dass diese Entität in Zukunft häufiger auftritt.
Investigation of some numerical issues in a chemistry‐transport model: Gas‐phase simulations
Authors: Mallet Vivien , Pourchet Adélaïde , Quélo Denis , Sportisse Bruno
Published: August 2007

Many numerical strategies have been specifically developed for chemistry‐transport models. Since no exact solutions are available for 3‐D real problems, there are only few insights to choose between alternative numerical schemes and approximations, or to estimate the performance discrepancy between two approaches. However it is possible to assess the importance of numerical approximations through the comparison of different strategies. We estimated the impact of several numerical schemes for advection, diffusion and stiff chemistry. We also addressed operator splitting with different methods and operator orders. The study is performed with a gas‐phase Eulerian model from the modeling platform Polyphemus. It is applied to ozone forecasts mainly over Europe, with focus on a few key species: ozone, nitric oxide, nitrogen dioxide, sulfur dioxide and hydroxy radical. The outcome is a ranking of the most sensitive numerical choices. It stresses the prominent impact of the advection scheme and of the splitting time step.
A bivariate gamma model for drought
Authors: Nadarajah Saralees
Published: August 2007

A drought application is described by deriving the exact distributions of the sum X + Y and the ratio X/(X + Y) and the corresponding moment properties when X and Y are drought duration and nondrought duration, respectively. The values of X and Y are modeled by a bivariate gamma distribution. Drought data from the State of Nebraska are used.
Indian Ocean response to anomalous conditions in 2006
Authors: Vinayachandran P. N. , Kurian Jaison , Neema C. P.
Published: August 2007

The equatorial Indian Ocean (EIO) exhibited anomalous conditions characteristic of an Indian Ocean dipole (IOD) during 2006. The eastern EIO had cold sea surface temperature anomalies (SSTA), lower sea level, shallow thermocline and higher chlorophyll than normal. The anomalies in the east, restricted to the south of the equator, were highest off Sumatra. The western pole of the IOD was marked by warm SSTA and deeper thermocline with maxima on either side of the equator. An ocean general circulation model of the Indian Ocean forced by QuikSCAT winds reproduces the IOD of 2006 remarkably well. The switch over to cooling in the east and warming in the west happened during May and July respectively. In the east, air‐sea heat flux initiated cold SSTA in the model which were sustained later by oceanic processes. In the west, surface heat fluxes and horizontal advection caused warm SSTA and contribution by the latter decreased after August.
Summer‐winter hemispheric asymmetry of the sudden increase in ionospheric total electron content and of the O/N2 ratio: Solar activity dependence
Authors: Tsugawa T. , Zhang S.‐R. , Coster A. J. , Otsuka Y. , Sato J. , Saito A. , Zhang Y. , Paxton L. J.
Published: August 2007

The solar activity dependence of the summer‐winter hemispheric asymmetry (SWHA) of the sudden increase in total electron content (SITEC) due to solar flares and of the O/N2 ratio is statistically analyzed using global GPS‐total electron content data and TIMED Global Ultraviolet Imager column O/N2 ratio data. We focus on observations with nonnegligible residuals of the solar zenith angle (SZA) dependency of SITEC. We examined 109 SITEC events associated with flares larger than M5 X‐ray class flare from 2000 through 2006 and compared the residual SITEC (δ) to the O/N2 ratio. We observed that the latitude gradient of δ has not only an annual variation but also a year‐to‐year variation that is similar to those of the O/N2 ratio. The SWHA magnitude (defined as the annual maximum of latitude gradient) of both δ and O/N2 decreases as the solar activity declines toward its minimum. The correlation coefficient between the annual SWHA magnitudes of δ and those of O/N2 is 0.92, indicating strongly that the SWHA of O/N2 is responsible for that of SITEC in both the annual and year‐to‐year variations. The X‐ray classes of the solar flares have no clear correlation with the solar activity, F10.7 index. We observe that the SWHA magnitude of δ does not depend on the magnitude of solar flare but rather on the background solar activity through the SWHA magnitude of the O/N2.
Equilibrium density of states and thermodynamic properties of a model glass former
Authors: Calvo Florent , Bogdan Tetyana V. , de Souza Vanessa K. , Wales David J.
Published: July 2007

This paper presents an analysis of the thermodynamics of a model glass former. We have performed equilibrium sampling of a popular binary Lennard-Jones model, employing parallel tempering Monte Carlo to cover the crystalline, amorphous, and liquid regions of configuration space. Disconnectivity graphs are used to visualize the potential energy landscape in the vicinity of a crystalline geometry and in an amorphous region of configuration space. The crystalline global minimum is separated from the bulk of the minima by a large potential energy gap, leading to broken ergodicity in conventional simulations. Our sampling reveals crystalline global minima that are lower in potential energy than some of the previous candidates. We present equilibrium thermodynamic properties based on parallel tempering simulations, including heat capacities and free energy profiles, which depend explicitly on the crystal structure. We also report equilibrium melting temperatures.
Cavitation in an orifice flow
Authors: Dabiri S. , Sirignano W. A. , Joseph D. D.
Published: July 2007

The purpose of this study is to identify the potential locations for cavitation induced by total stress on the flow of a liquid through an orifice of an atomizer. A numerical simulation of two-phase incompressible flow is conducted in an axisymmetric geometry of the orifice for Reynolds numbers between 100 and 2000. The orifice has a rounded upstream corner and a sharp downstream corner with length-to-diameter ratio between 0.1 and 5. The total stress including viscous stress and pressure has been calculated in the flow field and, from there, the maximum principal stress is found. The total-stress criterion for cavitation is applied to find the regions where cavitation is likely to occur and compared with those of the traditional pressure criterion. Results show that the viscous stress has significant effects on cavitation. The effect of geometry and occurrence of hydraulic flip in the orifice on the total stress are studied. The Navier-Stokes equations are solved numerically using a finite-volume method and a boundary-fitted orthogonal grid that comes from the streamlines and potential lines of an axisymmetric equipotential flow in the same geometry. A level-set formulation is used to track the interface and model the surface tension.
Cauchy problem for the generalized Benney-Luke equation
Authors: Wang Shubin , Xu Guixiang , Chen Guowang
Published: July 2007

This paper is concerned with the study of the Cauchy problem associated with an n-dimensional generalized Benney-Luke equation, utt−mΔu−Δutt+Δ2u+α(2∇u∙∇ut+utΔu)+β∇(∣∇u∣p∇u)=0, where n=1,2,3,4. We prove the existence and the uniqueness of the global solution of the Cauchy problem for the β⩽0 case by using energy conservation law and give the existence and the nonexistence of the global solution of the Cauchy problem for the β>0 case by constructing the stable set and the unstable set.
Optimizing chaos-based signals for complex radar targets
Authors: Carroll T. L.
Published: August 2007

There has been interest in the use of chaotic signals for radar, but most researchers consider only a few chaotic systems and how these signals perform for the detection of point targets. The range of possible chaotic signals is far greater than what most of these researchers consider, so to demonstrate this, I use a chaotic map whose parameters may be adjusted by a numerical optimization routine, producing different chaotic signals that are modulated onto a carrier and optimized for different situations. It is also suggested that any advantage for these chaos-based signals may come in the detection of complex targets, not point targets, and I compare the performance of chaos-based signals to a standard radar signal, the linear frequency modulated chirp. I find that I can optimize a chaos-based signal to increase the cross-correlation with the reflection from one complex target compared to the cross-correlation with the reflection from a different target, thus allowing the identification of a complex target. I am also able to increase the cross-correlation of the reflection from a complex target compared with the cross-correlation with the reflection from spatially extended clutter. I show that a larger output signal-to-noise ratio is possible if I cross-correlate with a reference signal that is different from the transmitted signal, and I justify my results by showing how the ambiguity diagram for a chaos-based signal can be different than the ambiguity diagram for a noise signal.
Phase diagram of model anisotropic particles with octahedral symmetry
Authors: Noya E. G. , Vega C. , Doye J. P. K. , Louis A. A.
Published: August 2007

The phase diagram for a system of model anisotropic particles with six attractive patches in an octahedral arrangement has been computed. This model for a relatively narrow value of the patch width where the lowest-energy configuration of the system is a simple cubic crystal. At this value of the patch width, there is no stable vapor-liquid phase separation, and there are three other crystalline phases in addition to the simple cubic crystal that is most stable at low pressure. First, at moderate pressures, it is more favorable to form a body-centered-cubic crystal, which can be viewed as two interpenetrating, and almost noninteracting, simple cubic lattices. Second, at high pressures and low temperatures, an orientationally ordered face-centered-cubic structure becomes favorable. Finally, at high temperatures a face-centered-cubic plastic crystal is the most stable solid phase.
Modeling diffusional transport in the interphase cell nucleus
Authors: Wedemeier Annika , Merlitz Holger , Wu Chen-Xu , Langowski Jörg
Published: July 2007

In this paper a lattice model for the diffusional transport of particles in the interphase cell nucleus is proposed. Dense networks of chromatin fibers are created by three different methods: Randomly distributed, noninterconnected obstacles, a random walk chain model, and a self-avoiding random walk chain model with persistence length. By comparing a discrete and a continuous version of the random walk chain model, we demonstrate that lattice discretization does not alter particle diffusion. The influence of the three dimensional geometry of the fiber network on the particle diffusion is investigated in detail while varying the occupation volume, chain length, persistence length, and walker size. It is shown that adjacency of the monomers, the excluded volume effect incorporated in the self-avoiding random walk model, and, to a lesser extent, the persistence length affect particle diffusion. It is demonstrated how the introduction of the effective chain occupancy, which is a convolution of the geometric chain volume with the walker size, eliminates the conformational effects of the network on the diffusion, i.e., when plotting the diffusion coefficient as a function of the effective chain volume, the data fall onto a master curve.
Al/Ti contacts to Sb-doped p-type ZnO
Authors: Mandalapu L. J. , Xiu F. X. , Yang Z. , Liu J. L.
Published: July 2007

Sb-doped p-type ZnO film was grown on Si (100) substrate by molecular-beam epitaxy. Al/Ti metal was evaporated on the ZnO film to form contacts. As-deposited contacts were Schottky with a barrier height of 0.8 eV. Ohmic conduction was achieved after thermal annealing. The different combinations of Ohmic and Schottky contacts on Sb-doped ZnO layer led to metal-semiconductor-metal (MSM), Schottky, and photoconductive devices. Ohmic contacts on Sb-doped p-type ZnO and backside of n-type Si substrate formed a heterojunction diode. MSM, Schottky, and photoconductor devices exhibited typical electrical characteristics, however, inverted rectification was observed for heterojunction diodes. All devices exhibited ultraviolet (UV) photoresponse. Secondary ion mass spectroscopy measurements were performed on the Ohmic and Schottky contacts on Sb-doped ZnO film to trace the metal profiles before and after annealing. Mechanisms of the formation of Schottky and Ohmic contacts to Sb-doped p-type ZnO and their device operation principles are discussed. This work suggests that Al/Ti can be used as both Ohmic and Schottky contacts to Sb-doped p-type ZnO for UV detection applications.
Probing the random distribution of half-metallic Co2Mn1−xFexSi Heusler alloys
Authors: Wurmehl Sabine , Kohlhepp Jürgen T. , Swagten Henk J. M. , Koopmans Bert , Wójcik Marek , Balke Benjamin , Blum Christian G. F. , Ksenofontov Vadim , Fecher Gerhard H. , Felser Claudia
Published: August 2007

Co 2 Mn 1 − x Fe x Si Heusler alloys crystallize in the L21 structure. This structure type requires random distribution of Mn and Fe in case of the mixed alloys. The spin echo nuclear magnetic resonance (NMR) technique probes the direct local environments of the active atoms and is thus able to resolve next neighboring shells providing a unique tool to verify the random distribution of Mn and Fe in Co2Mn1−xFexSi. Exemplarily, the half-metallic quaternary Heusler alloy Co2Mn0.5Fe0.5Si was investigated by means of NMR. The Mn55 NMR measurements unambiguously demonstrate the random distribution of Mn and Fe on the 4b Wyckoff position in Co2Mn0.5Fe0.5Si.
Inherent linearity in carbon nanotube field-effect transistors
Authors: Baumgardner James E. , Pesetski Aaron A. , Murduck James M. , Przybysz John X. , Adam John D. , Zhang Hong
Published: August 2007

The authors consider the suitability of carbon nanotubes for use in analog rf amplifiers, where the linearity of the device is critical. They show that in the limit of large electrostatic gate-channel capacitance, their theory predicts that an Ohmically contacted, ballistic carbon-nanotube-based field-effect transistor is inherently linear. While they have not achieved this limit in their experimental work, they compare the theory to experiment in the limit of small electrostatic gate-channel capacitance and find excellent agreement at virtually all bias conditions.
Photoemission study of ternary to penternary Fe-based metallic glasses: Chemical analysis of surface and bulk
Authors: Büttner M. , Wang H.-J. , Dongare A. M. , Shiflet G. J. , Reinke P. , Oelhafen P. , Mun B. S. , Gu X. J. , Poon S. J.
Published: August 2007

Bulk metallic glasses consisting of Fe, Mo, Cr, C, B, and Er have been investigated by x-ray photoelectron spectroscopy, aimed to elucidate the local atomic structure of the amorphous phase. In order to examine the electronic properties of this class of material, photon energy dependent measurements in combination with argon-ion irradiation were employed to identify and separate surface and bulk contributions to the spectra. The core levels suggest the presence of a carbon-rich surface layer with oxidized boron and metals, and metal carbides and borides in the bulk. Exposure to molecular oxygen and annealing experiments probe the chemical reactivity of the material. Formation of boron oxides at comparably low temperatures (300°C) might have consequences for the stability of the amorphous phase. We observe variations in binding energy of the Fe 3p core level with respect to the alloy composition, which indicate changes in the chemical state of iron.
Correlations between structure and random walk dynamics in directed complex networks
Authors: da Fontoura Costa Luciano , Sporns Olaf , Antiqueira Lucas , das Graças Volpe Nunes Maria , Oliveira Osvaldo N.
Published: August 2007

In this letter the authors discuss the relationship between structure and random walk dynamics in directed complex networks, with an emphasis on identifying whether a topological hub is also a dynamical hub. They establish the necessary conditions for networks to be topologically and dynamically fully correlated (e.g., word adjacency and airport networks), and show that in this case Zipf’s law is a consequence of the match between structure and dynamics. They also show that real-world neuronal networks and the world wide web are not fully correlated, implying that their more intensely connected nodes are not necessarily highly active.