bluuebunny/crossref_metadata_2025_split huggingface dataset:
Time-evolution of magma sources in a continental back-arc setting: the Cenozoic basalts from Sierra de San Bernardo (Patagonia, Chubut, Argentina)
Authors: BRUNI SANDRO , D'ORAZIO MASSIMO , HALLER MIGUEL J. , INNOCENTI FABRIZIO , MANETTI PIERO , PÉCSKAY ZOLTÁN , TONARINI SONIA 
Published: May 2008

AbstractEast of the Patagonian Andes, mafic volcanic rocks (mainly lava flows and scoriae) are exposed in the Sierra de San Bernardo fold belt and neighbouring areas (central Patagonia; 44.5–46° S, 69–71° W). They were erupted over a wide interval of time (late Eocene–Pleistocene; 14 new K–Ar ages), and show systematic chemical and Sr–Nd–Pb isotopic variations in time. The alkaline lavas (Mg number 57–66) erupted during the late Eocene and early Miocene, have an intraplate geochemical affinity, and have the highest 143Nd/144Nd and 206Pb/204Pb and the lowest 87Sr/86Sr ratios of the dataset. Their compositions indicate that their depth of equilibration in the mantle was greater than that of subsequent lavas. In contrast, the Plio-Pleistocene alkaline lavas (Mg number 58–71) are the most enriched in incompatible elements, still showing an intra-plate signature, and have the lowest 143Nd/144Nd and 206Pb/204Pb and the highest 87Sr/86Sr ratios. A distinctive group of early Miocene subalkaline lavas is characterized by slightly more evolved compositions (Mg number 56–59), coupled with very low incompatible element contents, flat LREE and fractionated HREE patterns (‘kinked’ pattern), and intermediate Sr–Nd–Pb isotope compositions. The Pleistocene basanites (Mg number 71–72) from the Cerro Ante monogenetic cone, on the easternmost slopes of the Patagonian Andes, have a marked orogenic geochemical signature and Sr–Nd–Pb isotope ratios that overlap with those of volcanic rocks from the adjacent active Andean arc. They originated in a mantle source extensively modified by the addition of materials from the subducting Pacific oceanic plates. We suggest that the wide chemical and isotopic variability of the Sierra de San Bernardo lavas reflects the upwelling of asthenospheric mantle beneath the study area, which induced lithospheric erosion and progressive involvement of enriched mantle domains in the genesis of magmas. In this context, late Eocene and early Miocene alkaline magmatism was dominantly sourced from the asthenospheric mantle, whereas Plio-Pleistocene alkaline magmas contain the largest proportion of an enriched lithospheric component. The peculiar compositional features of the early Miocene subalkaline lavas are interpreted in terms of high-degree mantle melting followed by melt–lithospheric mantle reaction processes. Based on current knowledge about the relative movement and decoupling between lithosphere and asthenosphere, we propose that the asthenosphere below the study area rose up to compensate for the westward drift of the mantle wedge coupled with the South American lithosphere.
THE EMERGENT LEGAL REGIME FOR EXPLORATION OF HYDROCARBONS IN THE GULF OF GUINEA: IMPERATIVE CONSIDERATIONS FOR PARTICIPATING STATES AND MULTINATIONALS
Authors: Oduntan Gbenga 
Published: May 2008

AbstractThis paper outlines recent developments in regional cooperation within the Gulf of Guinea region leading to the recent establishment of the Gulf of Guinea Commission. The huge interest generated among the major oil-producing multinational corporations, the newer independent producers and the participating States in the Gulf of Guinea necessitates a critical assessment of the Treaty Establishing the Gulf of Guinea Commission. This paper adopts a comparative analysis with pre-existing regional and institutional bodies having similar aims and objectives. The aim is to ascertain whether and to what extent the emergent regime can facilitate a sustainable and responsive regime for the anticipated explosion of exploitative activities in this resource-rich and strategic littoral zone. This paper, thus, places the existing regime in the context of international best practices for multinationals and governments involved in oil and gas exploration and production. The author identifies certain imperatives for the consideration of both the corporate and sovereign interests in the world's newest resource Eldorado.
FURTHER SUPPORT FOR THE HYPOTHESIS THAT PARENTAL HORMONE LEVELS AROUND THE TIME OF CONCEPTION ARE ASSOCIATED WITH HUMAN SEX RATIOS AT BIRTH
Authors: JAMES WILLIAM H. 
Published: May 2008

SummaryDuring the past year, data have been published on the offspring sex ratios of people diagnosed with toxoplasmosis, hepatitis B, and pre- and post-menopausal breast cancer. It is shown here how these offspring sex ratios constitute further support for the hypothesis that mammalian (including human) parental hormone concentrations around the time of conception partially control the sexes of the resulting infants. If this interpretation were correct, then hormonal treatments might be considered for some or all of these conditions. It is intended that anyone who has read the present note and my two previous papers (James, 1996, 2004) should be aware of all the data relating to the hypothesis.
Does the ‘gateway’ matter? Associations between the order of drug use initiation and the development of drug dependence in the National Comorbidity Study Replication
Authors: Degenhardt L. , Chiu W. T. , Conway K. , Dierker L. , Glantz M. , Kalaydjian A. , Merikangas K. , Sampson N. , Swendsen J. , Kessler R. C. 
Published: May 2008

BackgroundThe ‘gateway’ pattern of drug initiation describes a normative sequence, beginning with alcohol and tobacco use, followed by cannabis, then other illicit drugs. Previous work has suggested that ‘violations’ of this sequence may be predictors of later problems but other determinants were not considered. We have examined the role of pre-existing mental disorders and sociodemographics in explaining the predictive effects of violations using data from the US National Comorbidity Survey Replication (NCS-R).MethodThe NCS-R is a nationally representative face-to-face household survey of 9282 English-speaking respondents aged 18 years and older that used the World Health Organization (WHO) Composite International Diagnostic Interview (CIDI) to assess DSM-IV mental and substance disorders. Drug initiation was estimated using retrospective age-of-onset reports and ‘violations’ defined as inconsistent with the normative initiation order. Predictors of violations were examined using multivariable logistic regressions. Discrete-time survival analysis was used to see whether violations predicted progression to dependence.ResultsGateway violations were largely unrelated to later dependence risk, with the exception of small increases in risk of alcohol and other illicit drug dependence for those who initiated use of other illicit drugs before cannabis. Early-onset internalizing disorders were predictors of gateway violations, and both internalizing and externalizing disorders increased the risks of dependence among users of all drugs.ConclusionsDrug use initiation follows a strong normative pattern, deviations from which are not strongly predictive of later problems. By contrast, adolescents who have already developed mental health problems are at risk for deviations from the normative sequence of drug initiation and for the development of dependence.
A meta-analytic review of the effects of psychotherapy control conditions for anxiety disorders
Authors: Smits J. A. J. , Hofmann S. G. 
Published: May 2008

BackgroundLittle is known about the magnitude of improvement associated with psychotherapy control conditions for adult anxiety disorders. This information is important for the design of psychosocial treatment efficacy studies.MethodWe performed a computerized search of treatment outcome studies of anxiety disorders conducted between the first available year and 1 March 2007. In addition, we examined the reference lists from identified articles and asked international experts to identify eligible studies. We included studies that randomly assigned adult patients suffering from anxiety disorders to either cognitive–behavioral treatment or psychotherapy control condition. For each study, the two authors independently selected psychometrically sound measures of anxiety disorder severity. In addition, we collected data on attrition and treatment response.ResultsOf the 1165 studies that were initially identified, 19 studies (454 patients) met inclusion criteria and were included in the analyses. The random effects analysis yielded a pre- to post-treatment Hedges'geffect size of 0.45 (95% confidence interval 0.35–0.46,z=8.50,p<0.001). The mean weighted response and attrition rates were 25.0% and 14.2%, respectively. There was no evidence for publication bias, nor was there a significant relationship between the effect size and diagnostic group, study year or number of treatment sessions.ConclusionsPsychotherapy control conditions are associated with significant improvements when administered to adults suffering from anxiety disorders. In addition, they are associated with a relatively low attrition rate. These findings can inform the design of future psychotherapy outcome studies.
Epidemiology and cost of herpes zoster and post-herpetic neuralgia in the United Kingdom
Authors: GAUTHIER A. , BREUER J. , CARRINGTON D. , MARTIN M. , RÉMY V. 
Published: May 2008

SUMMARYRecent information on epidemiology and management of herpes zoster (HZ) and post-herpetic neuralgia (PHN), a painful complication of HZ, is scarce. The objective of this study was to document the burden of HZ and PHN in the United Kingdom. This retrospective analysis of the UK General Practice Research Database aimed to estimate HZ incidence and proportion of HZ patients developing PHN and to assess management costs in immunocompetent individuals aged ⩾50 years. A cohort of 27 225 HZ patients was selected, corresponding to an incidence of 5·23/1000 person-years. Respectively 19·5% and 13·7% of patients developed PHN at least 1 and 3 months after HZ diagnosis. Mean direct cost was £103 per HZ patient and £341 and £397 per PHN episode (1- and 3-month definition respectively). Both HZ and PHN costs increased markedly with pain severity. This study confirms that HZ and PHN are frequent and costly diseases in the United Kingdom.
An intervention to improve notifiable disease reporting using ambulatory clinics
Authors: TREPKA M. J. , ZHANG G. , LEGUEN F. 
Published: May 2008

SUMMARYStrong notifiable disease surveillance systems are essential for disease control. We sought to determine if a brief informational session between clinic and health department employees followed by reminder faxes and a newsletter would improve reporting rates and timeliness in a notifiable disease surveillance system. Ambulatory clinics were randomized to an intervention group which received the informational session, a faxed reporting reminder and newsletter, or to a control group. Among intervention and control clinics, there were improvements in the number of cases reported and the timeliness of reporting. However, there were no statistically significant changes in either group. Despite improved communication between the health department and clinics, this intervention did not significantly improve the level or the timeliness of reporting. Other types of interventions should be considered to improve reporting such as simplifying the reporting process.
Endozoochory by native and exotic herbivores in dry areas: consequences for germination and survival ofProsopisseeds
Authors: Campos Claudia M. , Peco Begoña , Campos Valeria E. , Malo Juan E. , Giannoni Stella M. , Suárez Francisco 
Published: May 2008

AbstractMammalian herbivores can play a role in the endozoochorous dispersal ofProsopisseeds in the arid zones of Argentina, and the introduction of exotic mammals can change relevant parameters of the plant's reproductive ecology. Our specific goals were to quantify the seeds ofProsopis flexuosa,P. chilensisandP. torquatacontained in the faeces of native [mara (Dolichotis patagonum), guanaco (Lama guanicoe)] and exotic [donkey (Equus asinus) and hare (Lepus europaeus)] mammals, and to determine the mortality, germination percentage and germination speed of seeds borne in faeces, compared with those collected from trees. In 2006, seeds were collected directly from trees or removed from mammal faeces. Seeds were counted and classified as apparently healthy or damaged.P. torquataandP. flexuosaseeds were found in the dung of guanaco, hare and mara, whereas onlyP. flexuosaseeds appeared in donkey faeces.P. chilensisseeds were only found in guanaco faeces. There was a notable relative abundance of seeds contained in small herbivore faeces in comparison to the large herbivores. The passage through the digestive tract of animals modified seed germination capacity and speed, with great variability between animal species. Guanacos had greater effects than donkeys on mortality, germination percentage and germination speed. Differences between the effects of both smaller-sized herbivores on seeds were much smaller.
Seed-bank dynamics in the invasive plant,Ambrosia artemisiifoliaL.
Authors: Fumanal B. , Gaudot I. , Bretagnolle F. 
Published: May 2008

AbstractThe seed-bank dynamics ofAmbrosia artemisiifolia(Asteraceae), an annual invasive plant introduced from North America to Europe, were studied in nine French populations developing in field crops, set-asides or wastelands. The vertical distribution of seeds was studied in two different depth sections (0–5 cm and 5–20 cm), and the spatial horizontal pattern of distribution was analysed for two selected field-crop and set-aside populations. The proportions of dormant, non-dormant and dead seeds, as well as the changes in seed-bank dormancy over time, were evaluated. Natural seedling recruitment and its variation under different disturbance treatments in competitive set-asides were also studied. From 536 ± 194 to 4477 ± 717 seeds m− 2were found in the living seed bank (0–20 cm). The majority of seeds in field crops was found in the lower soil layer, whereas the opposite pattern was observed in set-asides and wastelands. Dormant seed proportions were low (0–18%) before natural germination, but then regularly increased. The seed bank ofA. artemisiifoliawas spatially aggregated irrespective of the extent of soil disturbance. On average, 23 ± 12 to 292 ± 62 seedlings m− 2were recorded, with densities lower in set-asides than in field crops and wastelands. Seedling densities were not correlated to upper seed densities except for two field crops. Soil disturbance and the removal of vegetation had positive effects on seedling recruitment in set-asides. Seed-bank dynamics appear to be crucial in the invasive success ofA. artemisiifolia, and this knowledge will provide insights for the management of the species.
AnArabidopsis thalianaembryo arrest mutant exhibiting germination potential
Authors: Kristof Jessica R. , L. Coppersmith Jennifer , Hong Kyung , Liu Po-Pu , Homrichhausen Tanja M. , Sun Jing , Martin Ruth C. , Nonogaki Hiroyuki 
Published: May 2008

AbstractThe ability to initiate radicle elongation, or germination potential, occurs in developing embryos before the completion of seed maturation. Green embryos after the walking-stick stage in developingArabidopsis thalianaseeds germinate when excised from seeds and incubated in Murashige–Skoog (MS) medium containing 1% sucrose. Germination potential is not observed during early embryogenesis at the globular, heart and torpedo stages. Here, we describe anArabidopsismutant with embryos arrested at early stages of development, but still exhibiting germination potential. The mutant, termedembryo ball(eb), produced shrunken seeds containing round or irregularly shaped embryos that did not germinate. The round embryos excised from developingebseeds were capable of growing a primary root with root hairs when incubated in media. In contrast, cotyledons were absent at the apical region of theebembryos, although the apical region produced leaf-like structures with trichomes, indicating vegetative leaf identity. These observations suggested that morphological maturation was not essential for the induction of germination potential. Theebembryos exhibited partial desiccation tolerance that is characteristic of mature embryos at later stages of development, suggesting that cell maturation was also independent of morphological maturation. Theebmutant provides novel information on cell and tissue identity in developmental biology, as well as a useful tool to dissect the mechanisms underlying the induction of germination potential in developing seeds.
Probability models for detecting transgenic plants
Authors: Hernández-Suárez Carlos M. , Montesinos-López Osval A. , McLaren Graham , Crossa José 
Published: May 2008

AbstractWhen detecting the adventitious presence of transgenic plants (AP), it is important to use an appropriate testing method in the laboratory. Dorfman's group testing method is effective for reducing the number of laboratory analyses, but does not consider the case where AP is diluted below the sensitivity of the analyses, which causes the rate of false negatives to increase. The objective of this study is to propose binomial and negative binomial probabilistic models for determining the required sample size (n), number of pools (g), and size of the pool (k) for detecting individuals possessing AP with a probability ≥ (1 − α) (for a small α) given: (1) pool size (k); (2) estimated proportion of individuals with AP in the population (p); (3) concentration of the trait of interest (AP) in individual seeds (w); and (4) detection limit of the test (c) (AP concentration in a pool below which it cannot be detected). The proposed models consider the different rates of false positives (δ) and false negatives (λ), and the assessment of consumer and producer risks. Results have shown that when using the negative binomial, a required sample sizencan be determined that guarantees a high probability thatmindividuals orgpools containing AP will be found. The pools formed have an optimum size, such that one element with AP will be detected at a low cost. The negative binomial distribution should be used when it is known that the proportion of individuals with AP in the population isp < 0.1; thus, it is guaranteed thatmindividuals orgpools of individuals with AP will be detected with high probability.
A multiplanar three dimensional echocardiographic study of mitral valvar annular function in children with normal and regurgitant valves
Authors: Bharucha Tara , Sivaprakasam Muthukumaran C. , Roman Kevin S. , Vettukattil Joseph J. 
Published: May 2008

AbstractIntroductionThe mitral valvar complex is difficult to visualise accurately in only two dimensions. Three-dimensional echocardiography gives new insight into the dynamic changes of intra-cardiac structures during the cardiac cycle. The aim of this study was to study the mitral annulus in systole and diastole in normal children using three-dimensional echocardiography, and to analyse the effect of regurgitation on annular function.Materials and methodsThree-dimensional echocardiographic datasets, acquired in 11 consecutive subjects with mitral regurgitation, and 20 normal subjects, were analysed offline using simultaneous multiplanar review.ResultsThe mitral valvar annular area decreased in diastole, and increased in systole, in both groups. The annulus in patients with mitral regurgitation is dilated compared to normal subjects, the systolic value for those with regurgitation having a mean of 6.79 plus or minus 2.55 centimetres2/metres2, and the diastolic value a mean of 5.01 plus or minus 1.78 centimetres2/metres2, as opposed to a systolic mean value of 5.28 centimetres2/metres2 plus or minus 1.68, p = 0.091, and diastolic mean value of 3.05 centimetres2/metres2 plus or minus 0.90, in normal subjects (p less than 0.0001). The proportional change in mitral valvar annular area from systole to diastole showed a trend towards being smaller in those with mitral regurgitation, although this did not reach significance (24.8% versus 41.13%, p equal to 0.249). Analysis of subgroups of patients with moderate or severe mitral regurgitation showed mitral excursion, expressed as percentage of left ventricular length, to be significantly less than in normal subjects, at 12.78 plus or minus 5.10% versus 15.84 plus or minus 4.23% (p equal to 0.012).ConclusionsMitral valvar annular area in children decreases in diastole, and increases in systole. In those with mitral regurgitation, the annulus is dilated and the dynamic annular function is depressed.
Current status of adjuvant bisphosphonates in operable breast cancer
Authors: Paterson A. H. G. 
Published: May 2008

AbstractBisphosphonates offer a potentially effective adjuvant therapy to reduce recurrence of bone metastases in breast cancer patients. Clinical trials are at the early stage, but initial results have shown promise. There are three published adjuvant trials of oral clodronate, and one trial each of pamidronate and zoledronic acid. Observed complications so far include osteonecrosis of the jaw or maxilla because bisphosphonates inhibit bone turnover, as well as renal toxicity. Thus, care needs to be taken with dosage and duration of treatment and patients carefully managed.
Deferred compensation for career employees in public defined benefit pension plans: evidence from Colorado PERA
Authors: MANNINO MICHAEL V. , COOPERMAN ELIZABETH S. 
Published: May 2008

SUMMARYWith significant under funding of public defined benefit pension plans, public debate often focuses on funding problems, neglecting benefit-side factors that contribute to under funding. In this study we examine the benefit side by calculating the value of deferred compensation, using a unique dataset of salary histories for recent university retirees covered by the Colorado Public Employees Retirement Association plan. We find sizable levels of deferred compensation that is associated with retirement age and period, job class, service years, and to some extent gender, with administrators receiving the highest levels. We also find wage–earning profiles to underestimate salary growth for higher-paid employees.
Formation of Stellar Clusters and the Importance of Thermodynamics for Fragmentation
Authors: Klessen Ralf S. , Clark Paul C. , Glover Simon C. O. 
Published: May 2008

AbstractWe discuss results from numerical simulations of star cluster formation in the turbulent interstellar medium (ISM). The thermodynamic behavior of the star-forming gas plays a crucial role in fragmentation and determines the stellar mass function as well as the dynamic properties of the nascent stellar cluster. This holds for star formation in molecular clouds in the solar neighborhood as well as for the formation of the very first stars in the early universe. The thermodynamic state of the ISM is a result of the balance between heating and cooling processes, which in turn are determined by atomic and molecular physics and by chemical abundances. Features in the effective equation of state of the gas, such as a transition from a cooling to a heating regime, define a characteristic mass scale for fragmentation and so set the peak of the initial mass function of stars (IMF). As it is based on fundamental physical quantities and constants, this is an attractive approach to explain the apparent universality of the IMF in the solar neighborhood as well as the transition from purely primordial high-mass star formation to the more normal low-mass mode observed today.