bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation analysis and performance of a feasible GNSS system with multi-beam antennas deployment operating in Galileo frequency bands
Authors: Angelis Constantinos T.
Published: July 2012

New Global Navigation Satellite System (GNSS) systems under development, such as Galileo, are very promising for future global positioning-based applications. A vast research is undergoing a final stage of implementation in order to fulfill the primary purpose of European Space Agency for developing and then sustaining of 30 (27 + 3 spares) Galileo satellites in orbit. This article presents simulation results for a realistic deployment of multibeam antennas, with a new modified theoretical pattern, in GNSS Satellite Systems. The proposed multibeam antennas use 61-spot beams for maximum efficiency in terms of satellite coverage and accessing high quality of service. In order to prove the reliability and feasibility of this work, various simulations were conducted using the upcoming Galileo system as a platform taking into consideration real-world conditions. Gain analysis versus elevation, Bit Error Rate (BER) and access time simulation results show that the viability of the proposed multibeam antenna deployment is established.
Neonatal Morbidity in Growth-Discordant Monochorionic Twins: Comparison Between the Larger and the Smaller Twin
Authors: Lopriore Enrico , Sluimers Carolien , Pasman Suzanne A. , Middeldorp Johanna M. , Oepkes Dick , Walther Frans J.
Published: July 2012

Fetal growth restriction in singletons has been shown to enhance fetal lung maturation and reduce the risk of respiratory distress syndrome due to increased endogenous steroid production. However, data on lung maturation in growth-discordant monochorionic (thus, identical) twins are lacking. Our objective was to compare the risk of severe neonatal morbidity between the larger and the smaller twin in monochorionic twins with birth weight discordance (BWD). We included in the study all consecutive monochorionic diamniotic pregnancies with severe BWD (≥25%) and two live-born twins delivered at our center (n = 47 twin pairs). We compared the incidence of neonatal morbidity, particularly respiratory distress syndrome (RDS), and cerebral lesions between the larger and the smaller co-twin. The incidence of severe neonatal morbidity in the larger and smaller twin was 38% (18/47) and 19% (9/47), respectively (odds ratio (OR) 2.66, 95% confidence interval (CI) 0.94–7.44) and was due primarily to the higher incidence of RDS, 32% (15/47) and 6% (3/47), respectively (OR 6.88, 95% CI 1.66–32.83). In conclusion, this study shows that the larger twin in monochorionic twin pairs with BWD is at increased risk of severe neonatal morbidity, particularly RDS, compared to the smaller twin.
Genetic Correlations Among Facets of Type A Behavior and Personality
Authors: Johnson Andrew M. , Schermer Julie Aitken , Vernon Philip A. , Jang Kerry L.
Published: July 2012

The purpose of this study was to examine the phenotypic, genetic, and environmental relationships between multiple dimensions of Type A behavior and personality. Adult twins (N = 247 pairs) completed a self-report personality measure and a work style questionnaire that measured six facets of Type A behavior: impatience, anger, work involvement, time urgency, job dissatisfaction, and competitiveness. Univariate results suggest that only the job dissatisfaction facet of Type A behavior was explained by non-genetic (environmental) factors. Multivariate results suggest that all of the genetically determined facets of Type A behavior show some correspondence with at least one of the personality factors found in the study, suggesting that some of the phenotypic (observed) relationships could be due to common genetic factors.
Prospective Risk of Intrauterine Fetal Death in Monoamniotic Twin Pregnancies
Authors: Morikawa Mamoru , Yamada Takashi , Yamada Takahiro , Sato Shoji , Minakami Hisanori
Published: July 2012

This study was conducted to review the overall short-term outcome of monoamniotic twins in Japan and to determine the prospective risk of fetal death so as to adequately counsel parents with monoamniotic twins. Study subjects were 101 women with monoamniotic twins who were registered with the Japan Society of Obstetrics and Gynecology Successive Pregnancy Birth Registry System and who had given birth at ≥22 weeks of gestation during 2002–2009. The gestational week at delivery (mean ± SD) was 31.8 ± 3.7. Fourteen women experienced intrauterine fetal death (IUFD). Short-term outcomes of co-twins born to the 14 women included 8 IUFDs, one early neonatal death within 7 days of life (END), and 5 survivors. Four other women experienced 5 ENDs. Thus, 13.9% (28/202) of infants died perinatally (22 IUFDs and 6 ENDs), 13.9% (14/101) of women experienced IUFD, and 82.2% (83/101) of women experienced neither IUFD nor END. Structural anomalies and twin-to-twin transfusion syndrome explained 17.9% (five infants) and 10.7% (three infants) of the 28 perinatal deaths, respectively. The prospective risk of IUFD was 13.9% (14/101) for women who reached gestational week 22−0/7, gradually decreasing thereafter but remaining at between 4.5% and 8.0% between gestational week 30−0/7 and 36−0/7.
The Genetic Correlation Between Cigarette Smoking and Alcohol Drinking Among Chinese Adult Male Twins: An Ordinal Bivariate Genetic Analysis
Authors: Zhang Ting , Gao Wenjing , Cao Weihua , Zhan Siyan , Lv Jun , Pang Zengchang , Wang Shaojie , Chen Rongfu , Hu Yonghua , Li Liming
Published: July 2012

Background: Though multiple policies have been implemented, the cigarette control in China is still facing a great challenge. At the same time, alcohol drinking has increasingly become a public health problem. Considering cigarette smoking and alcohol drinking often co-occur, a few studies tested the covariance of these phenotypes. However, the genetic and environmental correlation between them among Chinese population has not been determined. The main aim of this study is to fill this gap. Methods: From the Chinese National Twin Registry, we obtained the data on cigarette smoking and alcohol drinking behaviors. The ordinal bivariate genetic analysis was performed to fit the categorical variables. After identifying the best decomposition among the Cholesky, common, and independent pathway model, we established the most parsimonious submodel. Results: The correlation between current tobacco and alcohol use could be explained by Cholesky model. The shared environmental variances for both phenotypes were dropped to construct the most parsimonious submodel. Furthermore, the most parsimonious submodel showed a moderate correlation (0.32, 95%CI = 0.17 – 0.46) between the genetic components and a negligible non-shared environmental correlation. Conclusion: As the first bivariate genetic analysis on current tobacco smoking and current alcohol drinking in China, this study suggested a common genetic vulnerability to tobacco and alcohol use in male twins. Further studies should be carried out to track the pertinent genes that are related to the comorbidity of smoking and drinking in Chinese population. Another urgent need is to recognize the behavior-specific environmental risk factors.
Current Evidence on VEGF+405G/C Polymorphism and Malignancy Susceptibility: A Meta-Analysis Involving 30 Studies
Authors: Hu Kai , Zhang Yong , Wang Rensheng , Li Guojian , Li Guihua , Zhang Dawei
Published: July 2012

The association of VEGF+405G/C (where VEGF is vascular endothelial growth factor) polymorphism and malignancy susceptibility attracts considerable attention because VEGF is one of the most potent angiogenic factors and plays a critical role in the onset and development of malignancy. However, the published findings remain inconclusive. In order to derive a more precise assessment of the association, we performed a meta-analysis including 30 published case-control studies from PubMed, Embase, and Ovid databases. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association. In the pooled analyses, no significant association was found between VEGF+405G/C polymorphism and malignancy susceptibility in different genetic models (G-allele vs. C-allele: OR = 1.00, 95% CI: 0.93–1.07; CC vs. GG: OR = 1.01, 95% CI: 0.88–1.15; GC+CC vs. GG: OR = 1.00, 95% CI: 0.91–1.10; CC vs. GC+GG: OR = 1.01, 95% CI: 0.90–1.13). When stratified by ethnicity, a weak association between this polymorphism and malignancy susceptibility was found in African under allelic frequency comparison (OR = 0.65, 95% CI: 0.43–0.98) and dominant genetic model comparison (OR = 1.95, 95% CI: 1.09–3.50). In summary, although our meta-analysis indicated a weak association of VEGF+405G/C polymorphism with malignancy susceptibility in African, no persuasive evidence of association between the polymorphism and malignancy susceptibility was detected in the pooled analyses. Therefore, more studies with larger scale of participants, especially Africans, are required to further evaluate gene-environment interaction on this polymorphism and malignancy susceptibility.
Dichorionic Pregnancy: Delayed Interval Delivery With Endoloop Ligation
Authors: Surico D. , Amadori R. , Ferrero F. , Vigone A. , Leo L. , Surico N.
Published: July 2012

We describe two cases of delayed delivery in dichorionic, diamniotic pregnancies, where we used an Endoloop ligature to clamp the umbilical cord with excellent maternal and fetal long-term outcome.
Acyl-homoserine lactone-dependent eavesdropping promotes competition in a laboratory co-culture model
Authors: Chandler Josephine R , Heilmann Silja , Mittler John E , Greenberg E Peter
Published: July 2012

Many Proteobacteria use acyl-homoserine lactone (AHL)-mediated quorum sensing to activate the production of antibiotics at high cell density. Extracellular factors like antibiotics can be considered public goods shared by individuals within a group. Quorum-sensing control of antibiotic production may be important for protecting a niche or competing for limited resources in mixed bacterial communities. To begin to investigate the role of quorum sensing in interspecies competition, we developed a dual-species co-culture model using the soil saprophytes Burkholderia thailandensis (Bt) and Chromobacterium violaceum (Cv). These bacteria require quorum sensing to activate the production of antimicrobial factors that inhibit growth of the other species. We demonstrate that quorum-sensing-dependent antimicrobials can provide a competitive advantage to either Bt or Cv by inhibiting growth of the other species in co-culture. Although the quorum-sensing signals differ for each species, we show that the promiscuous signal receptor encoded by Cv can sense signals produced by Bt, and that this ability to eavesdrop on Bt can provide Cv an advantage in certain situations. We use an in silico approach to investigate the effect of eavesdropping in competition, and show conditions where early activation of antibiotic production resulting from eavesdropping can promote competitiveness. Our work supports the idea that quorum sensing is important for interspecies competition and that promiscuous signal receptors allow eavesdropping on competitors in mixed microbial habitats.
Overcoming multidrug-resistance in vitro and in vivo using the novel P-glycoprotein inhibitor 1416
Authors: Xu Yan , Zhi Feng , Xu Guangming , Tang Xiaolei , Lu Sheng , Wu Jinhui , Hu Yiqiao
Published: July 2012

MDR (multidrug-resistance) represents a major obstacle to successful cancer chemotherapy and is usually accomplished by overexpression of P-gp (P-glycoprotein). Much effort has been devoted to developing P-gp inhibitors to modulate MDR. However, none of the inhibitors on the market have been successful. 1416 [1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino)propane hydrochloride (phenoprolamine hydrochloride)] is a new VER (verapamil) analogue with a higher IC50 for blocking calcium channel currents than VER. In the present paper, we examined the inhibition effect of 1416 on P-gp both in vitro and in vivo. 1416 significantly enhanced cytotoxicity of VBL (vinblastine) in P-gp-overexpressed human multidrug-resistant K562/ADM (adriamycin) and KBV cells, but had no such effect on the parent K562 and KB cells. The MDR-modulating function of 1416 was further confirmed by increasing intracellular Rh123 (rhodanmine123) content in MDR cells. Human K562/ADM xenograft-nude mice model verified that 1416 potentiates the antitumour activity of VBL in vivo. RT-PCR (reverse transcriptase-PCR) and FACS analysis demonstrated that the expression of MDR1/P-gp was not affected by 1416 treatment. All these observations suggest that 1416 could be a promising agent for overcoming MDR in cancer chemotherapy.
Population Genetics of Southern Flounder with Implications for Management
Authors: Anderson J. D. , Karel W. J.
Published: July 2012

The southern flounder Paralichthys lethostigma is a marine flatfish that ranges from North Carolina to the Yucatan Peninsula in the Gulf of Mexico. Management of southern flounder will be improved by proper delineation of management units based on genetic data. We used microsatellite DNA markers to determine how many populations exist across the species’ range and the geographic extent of those populations. Based on significant genetic divergence across loci (F  CT = 0.035), two discrete populations of southern flounder occur. The populations inhabit the Gulf of Mexico and Atlantic Ocean, with the boundary between them located in southern Florida, an area that is generally devoid of southern flounder. Within the Gulf of Mexico, there was little evidence of discrete populations but weak evidence for isolation by distance. These data indicate that specieswide management of southern flounder should account for the independent demographic entities in the Gulf and Atlantic and that local management strategies should account for the upper limits to dispersal within the Gulf.

Received January 12, 2012; accepted April 12, 2012
Structure and piezoelectric properties of (1 − 0.5x)BaTiO3–0.5x (0.4BaZrO3–0.6CaTiO3) ceramics
Authors: Liu Laijun , Zheng Shaoying , Huang Yanming , Shi Danping , Wu Shuangshuang , Fang Liang , Hu Changzheng , Elouadi Brahim
Published: July 2012

(1 − 0.5x)BaTiO3–0.5x (0.4BaZrO3–0.6CaTiO3) (0 ⩽ x ⩽ 0.875) ceramics were fabricated by a conventional solid-state technique. The influence of the substitution content on crystallographic structure, phase transition, piezoelectric and ferroelectric properties was investigated. A morphotropic phase boundary from a cubic–rhombohedral–tetragonal tricritical triple point was found in x = 0.375–0.500. The sample with x = 0.375, sintered at a lower temperature (1623 K), showed excellent piezoelectric performance (d
33 = 420 pC N−1, k
p = 57%, Q
m = 120.2 and T
C = 380 K) and good thermal stability up to 370 K.
Integrated real-time control of MHD instabilities using multi-beam ECRH/ECCD systems on TCV
Authors: Felici F. , Goodman T.P. , Sauter O. , Canal G. , Coda S. , Duval B.P. , Rossel J.X.
Published: July 2012

Simultaneous real-time control of multiple MHD instabilities is experimentally demonstrated in the TCV tokamak. Multiple sources of EC heating and current drive, injected through real-time controlled launchers, are used to stabilize 3/2 and 2/1 neoclassical tearing modes (NTMs) rapidly after their appearance. Control of the sawtooth instability using a new sawtooth-pacing technique is demonstrated, providing precise control of the time of appearance of the sawtooth crash. Efficient NTM preemption can then be performed by applying pulsed power on the mode rational surface at the time of the seed-island generating sawtooth crash. These three elements are combined into one integrated control system which can simultaneously control the sawtooth period, preempt the formation of NTMs and suppress these if they appear.
A potentially robust plasma profile control approach for ITER using real-time estimation of linearized profile response models
Authors: Kim S.H. , Lister J.B.
Published: July 2012

An active plasma profile control approach for ITER, which is potentially robust by being tolerant to changing and uncertain physics, has been explored in this work, using a technique based on real-time estimation of linearized profile response models. The linearized models approximate static responses of the plasma profiles to power changes in auxiliary heating and current drive systems. These models are updated in real-time, differing from the model-based technique which deduces a dynamic model from identification experiments. The underlying physics is simplified with several assumptions to allow real-time update of the profile response models; however, without significant loss of information necessary for feedback control of the plasma profiles. The response of the electron temperature profile is modelled by simplifying the electron heat transport equation. The response of the safety factor profile is computed by directly relating it to the changes in source current density profiles. The required actuator power changes are directly computed by inverting the response matrix using the singular value decomposition technique. The saturation of the actuator powers is taken into account and the capability of using quantized auxiliary powers is provided. The potential of our active control approach has been tested by applying it to simulations of the ITER hybrid mode operation using CRONOS. In these simulations, either a global transport model or a theory-based local transport model has been used and the electron temperature and safety factor profiles were well controlled either independently or simultaneously.
Sawtooth period control strategies and designs for improved performance
Authors: Witvoet G. , Steinbuch M. , de Baar M.R. , Doelman N.J. , Westerhof E.
Published: July 2012

The sawtooth instability is associated with the triggering of neo-classical tearing modes, core fuelling, α-confinement and the exhaust of thermal helium. Sawtooth control is therefore important for optimal reactor performance in ELMy H-modes. Control schemes for the sawtooth period have been published in the literature, but the systematic design of high-performance controllers (yielding accurate and fast convergent responses) has not been addressed. In this work, three control strategies for high-performance sawtooth control are presented using electron cyclotron current drive (ECCD). Both degrees of freedom of the ECCD actuator will be explored and combined with advanced controller designs. First, the ECCD deposition location is used as a control variable, for which a gain-scheduled feedback controller and static feedforward control is derived. Second, the use of the driven current as a control variable is explored, and a simple controller is designed based on the identified dynamics. In the third approach both control variables are joined in an overall controller design, which enables the combination of high-performance control of the sawtooth period and control of the gyrotron power. Time-domain simulations with a combined Kadomtsev–Porcelli sawtooth model show that each strategy obtains a better closed-loop performance than standard linear feedback techniques on merely the deposition location.
Thermoelectric currents and their role during ELM formation in JET
Authors: Rack M. , Wingen A. , Liang Y. , Spatschek K.H. , Harting D.M. , Devaux S.
Published: July 2012

A recently developed numerical model, describing a self-amplification and structure formation process which is used to model the initial non-linear growth phase of edge-localized modes (ELMs), is applied to the JET tokamak. Connection length simulations of the magnetic topology, including only error fields, for JET reveal the existence of small, so-called short connection length flux tubes. Such a configuration is used as the starting point for the model. Thermoelectric currents are assumed to flow in the short connection length flux tubes and add additional magnetic perturbations which change the magnetic topology severely. The change in magnetic topology leads to the formation of new, much larger short connection length flux tubes that can conduct much larger currents through the plasma edge. The current density inside the flux tubes is assumed to be constant to calculate the total current. This self-amplification process leads to the formation of patterns, known as footprints, on various segments of the inner wall throughout the vessel. The resulting footprints and their relation to the observed ELM patterns during discharges are discussed.
Pellet fuelling requirements to allow self-burning on a helical-type fusion reactor
Authors: Sakamoto R. , Miyazawa J. , Yamada H. , Masuzaki S. , Sagara A.
Published: July 2012

Pellet refuelling conditions to sustain a self-burning plasma have been investigated by extrapolating the confinement property of the LHD plasma, which appears to be governed by a gyro-Bohm-type confinement property. The power balance of the burning plasma is calculated taking into account the profile change with pellet deposition and subsequent density relaxation. A self-burning plasma is achieved within the scope of conventional pellet injection technology. However, a very small burn-up rate of 0.18% is predicted. Higher velocity pellet injection is effective in improving the burn-up rate by deepening particle deposition, whereas deep fuelling leads to undesirable fluctuation of the fusion output.
Biomass size spectra of mesozooplankton in the Chukchi Sea during the summers of 1991/1992 and 2007/2008: an analysis using optical plankton counter data
Authors: Matsuno Kohei , Yamaguchi Atsushi , Imai Ichiro
Published: July 2012

Matsuno, K., Yamaguchi, A., and Imai, I. 2012. Biomass size spectra of mesozooplankton in the Chukchi Sea during the summers of 1991/1992 and 2007/2008: an analysis using optical plankton counter data. – ICES Journal of Marine Science, 69: . An optical plankton counter was used to examine the regional characteristics of the zooplankton communities in the Chukchi Sea during the summers of 1991, 1992, 2007, and 2008. Zooplankton abundance and biomass ranged from 5000 to 1 170 000 ind. m−2 and 0.2 to 10.9 g dry mass m−2, respectively. Based on zooplankton biovolume in equivalent spherical diameter (ESD) in 48 bins, one every 0.1 mm between 0.25 and 5.0 mm, a Bray–Curtis cluster analysis classified zooplankton communities into four groups (A–D). No changes were observed in zooplankton communities south of the Lisburne Peninsula (group A) throughout the 4 years, but there were differences north of the Peninsula, with group B (normal, intermediate biomass) observed in 1991/1992, group D (low biomass) in 2007, and group C (predominance of barnacle larvae) in 2008. Analysis of the normalized biomass size spectra for the groups indicated that groups A and C were very productive, so the zooplankton community south of the Lisburne Peninsula was consistently highly productive, which may be because of the continuous inflow of Pacific Water rich in nutrients. Zooplankton communities north of the Lisburne Peninsula varied greatly from year to year, which may be related to interannual changes in sea-ice extent.
Evolution of clonal populations approaching a fitness peak
Authors: Gordo Isabel , Campos Paulo R. A.
Published: July 2012

Populations facing novel environments are expected to evolve through the accumulation of adaptive substitutions. The dynamics of adaptation depend on the fitness landscape and possibly on the genetic background on which new mutations arise. Here, we model the dynamics of adaptive evolution at the phenotypic and genotypic levels, focusing on a Fisherian landscape characterized by a single peak. We find that Fisher's geometrical model of adaptation, extended to allow for small random environmental variations, is able to explain several features made recently in experimentally evolved populations. Consistent with data on populations evolving under controlled conditions, the model predicts that mean population fitness increases rapidly when populations face novel environments and then achieves a dynamic plateau, the rate of molecular evolution is remarkably constant over long periods of evolution, mutators are expected to invade and patterns of epistasis vary along the adaptive walk. Negative epistasis is expected in the initial steps of adaptation but not at later steps, a prediction that remains to be tested. Furthermore, populations are expected to exhibit high levels of phenotypic diversity at all times during their evolution. This implies that populations are possibly able to adapt rapidly to novel abiotic environments.
North Sea ecosystem change from swimming crabs to seagulls
Authors: Luczak C. , Beaugrand G. , Lindley J. A. , Dewarumez J-M. , Dubois P. J. , Kirby R. R.
Published: July 2012

A recent increase in sea temperature has established a new ecosystem dynamic regime in the North Sea. Climate-induced changes in decapods have played an important role. Here, we reveal a coincident increase in the abundance of swimming crabs and lesser black-backed gull colonies in the North Sea, both in time and in space. Swimming crabs are an important food source for lesser black-backed gulls during the breeding season. Inhabiting the land, but feeding mainly at sea, lesser black-backed gulls provide a link between marine and terrestrial ecosystems, since the bottom-up influence of allochthonous nutrient input from seabirds to coastal soils can structure the terrestrial food web. We, therefore, suggest that climate-driven changes in trophic interactions in the marine food web may also have ensuing ramifications for the coastal ecology of the North Sea.
Criticality and the onset of ordering in the standard Vicsek model
Authors: Baglietto Gabriel , Albano Ezequiel V. , Candia Julián
Published: July 2012

Experimental observations of animal collective behaviour have shown stunning evidence for the emergence of large-scale cooperative phenomena resembling phase transitions in physical systems. Indeed, quantitative studies have found scale-free correlations and critical behaviour consistent with the occurrence of continuous, second-order phase transitions. The standard Vicsek model (SVM), a minimal model of self-propelled particles in which their tendency to align with each other competes with perturbations controlled by a noise term, appears to capture the essential ingredients of critical flocking phenomena. In this paper, we review recent finite-size scaling and dynamical studies of the SVM, which present a full characterization of the continuous phase transition through dynamical and critical exponents. We also present a complex network analysis of SVM flocks and discuss the onset of ordering in connection with XY-like spin models.
Haemodynamics in the mouse aortic arch computed from MRI-derived velocities at the aortic root
Authors: Van Doormaal Mark A. , Kazakidi Asimina , Wylezinska Marzena , Hunt Anthony , Tremoleda Jordi L. , Protti Andrea , Bohraus Yvette , Gsell Willy , Weinberg Peter D. , Ethier C. Ross
Published: July 2012

Mice are widely used to investigate atherogenesis, which is known to be influenced by stresses related to blood flow. However, numerical characterization of the haemodynamic environment in the commonly studied aortic arch has hitherto been based on idealizations of inflow into the aorta. Our purpose in this work was to numerically characterize the haemodynamic environment in the mouse aortic arch using measured inflow velocities, and to relate the resulting shear stress patterns to known locations of high- and low-lesion prevalence. Blood flow velocities were measured in the aortic root of C57/BL6 mice using phase-contrast MRI. Arterial geometries were obtained by micro-CT of corrosion casts. These data were used to compute blood flow and wall shear stress (WSS) patterns in the arch. WSS profiles computed using realistic and idealized aortic root velocities differed significantly. An unexpected finding was that average WSS in the high-lesion-probability region on the inner wall was actually higher than the WSS in the low-probability region on the outer wall. Future studies of mouse aortic arch haemodynamics should avoid the use of idealized inflow velocity profiles. Lesion formation does not seem to uniquely associate with low or oscillating WSS in this segment, suggesting that other factors may also play a role in lesion localization.
Single-locus species delimitation: a test of the mixed Yule–coalescent model, with an empirical application to Philippine round-leaf bats
Authors: Esselstyn Jacob A. , Evans Ben J. , Sedlock Jodi L. , Anwarali Khan Faisal Ali , Heaney Lawrence R.
Published: July 2012

Prospects for a comprehensive inventory of global biodiversity would be greatly improved by automating methods of species delimitation. The general mixed Yule–coalescent (GMYC) was recently proposed as a potential means of increasing the rate of biodiversity exploration. We tested this method with simulated data and applied it to a group of poorly known bats (
Hipposideros
) from the Philippines. We then used echolocation call characteristics to evaluate the plausibility of species boundaries suggested by GMYC. In our simulations, GMYC performed relatively well (errors in estimated species diversity less than 25%) when the product of the haploid effective population size (
N
e
) and speciation rate (SR; per lineage per million years) was less than or equal to 10
5
, while interspecific variation in
N
e
was twofold or less. However, at higher but also biologically relevant values of
N
e
× SR and when
N
e
varied tenfold among species, performance was very poor. GMYC analyses of mitochondrial DNA sequences from Philippine
Hipposideros
suggest actual diversity may be approximately twice the current estimate, and available echolocation call data are mostly consistent with GMYC delimitations. In conclusion, we consider the GMYC model useful under some conditions, but additional information on
N
e
, SR and/or corroboration from independent character data are needed to allow meaningful interpretation of results.
A global analysis of fine root production as affected by soil nitrogen and phosphorus
Authors: Yuan Z. Y. , Chen Han Y. H.
Published: July 2012

Fine root production is the largest component of belowground production and plays substantial roles in the biogeochemical cycles of terrestrial ecosystems. The increasing availability of nitrogen (N) and phosphorus (P) due to human activities is expected to increase aboveground net primary production (ANNP), but the response of fine root production to N and P remains unclear. If roots respond to nutrients as ANNP, fine root production is anticipated to increase with increasing soil N and P. Here, by synthesizing data along the nutrient gradient from 410 natural habitats and from 469 N and/or P addition experiments, we showed that fine root production increased in terrestrial ecosystems with an average increase along the natural N gradient of up to 0.5 per cent with increasing soil N. Fine root production also increased with soil P in natural conditions, particularly at P < 300 mg kg
−1
. With N, P and combined N + P addition, fine root production increased by a global average of 27, 21 and 40 per cent, respectively. However, its responses differed among ecosystems and soil types. The global average increases in fine root production are lower than those of ANNP, indicating that above- and belowground counterparts are coupled, but production allocation shifts more to aboveground with higher soil nutrients. Our results suggest that the increasing fertilizer use and combined N deposition at present and in the future will stimulate fine root production, together with ANPP, probably providing a significant influence on atmospheric CO
2
emissions.
Impact of capsid modifications by selected peptide ligands on recombinant adeno-associated virus serotype 2-mediated gene transduction
Authors: Naumer Matthias , Popa-Wagner Ruth , Kleinschmidt Jürgen A.
Published: July 2012

Vectors based on adeno-associated virus serotype 2 (AAV2) belong to today’s most promising and most frequently used viral vectors in human gene therapy. Like in many other vector systems, the broad but non-specific tropism limits their use for certain cell types or tissues. One approach to screen for transduction-improved vectors is the selection of random peptide libraries displayed directly on the AAV2 capsid. Although the AAV2 library system has been widely applied for the successful selection of improved gene therapy vectors, it remains unknown which steps of the transduction process are most affected and therefore critical for the selection of targeting peptides. Attachment to the cell surface is the first essential step of AAV-mediated gene transduction; however, our experiments challenge the conventional belief that enhanced gene transfer is equivalent to more efficient cell binding of recombinant AAV2 vectors. A comparison of the various steps of gene transfer by vectors carrying a wild-type AAV2 capsid or displaying two exemplary peptide ligands selected from AAV2 random libraries on different human tumour cell lines demonstrated strong alterations in cell binding, cellular uptake, as well as intracellular processing of these vectors. Combined, our results suggest that entry and post-entry events are decisive for the selection of the peptides NDVRSAN and GPQGKNS rather than their cell binding efficiency.
(R)-3,3-Diethyl-1-(2-hydroxy-1-phenylethyl)piperidin-2-one
Authors: Romero Oscar , Ramírez Johana , Terán Joel L. , Flores-Alamo Marcos , Juárez Jorge R.
Published: July 2012

In the title compound C17H25NO2, the piperidin-2-one ring adopts an envelope conformation with the C atom in the 5-position as the flap. The crystal packing is stabilized by intermolecular O—H...O hydrogen bonds, building a infinite chain along theb-axis direction. C—H...π interactions further stabilize the crystal packing.
Methyl 2-(4a,8-Dimethyl-7-oxodecahydronaphthalen-2-yl)acrylate
Authors: Tebbaa Mohamed , Benharref Ahmed , Daran Jean-Claude , Barkaoui Latifa , Berraho Moha
Published: July 2012

The title compound, C16H24O3, was isolated from the aerial part ofInula Viscosa(L) Aiton [orDittrichia Viscosa(L) Greuter]. The molecule contains two fused (trans) six-membered rings which both exibit a chair conformation. In the crystal, molecules are linked into chains along [100] by weak C—H...O hydrogen bonds involving the methyl and carbonyl groups.
16α,17α-Epoxy-17β-(1H-imidazol-1-yl)androst-4-en-3-one monohydrate
Authors: Anitha A. G. , Hema R. , Bansal Ranju , Thota Sridhar , Rizwana Begum S.
Published: July 2012

In the title compound, C22H28N2O2·H2O, ringsBandCadopt chair conformations. RingAadopts an envelope conformation, with the non-fused C atom adjacent to the fused C atom bearing a methyl group as the flap atom. RingDalso adopts an envelope conformation, with the fused C atom not bearing a methyl group as the flap atom. The water molecule links the moleculesviaO—H...O and O—H...N hydrogen bonds, forming zigzag chains which run parallel to thecaxis. Weak C—H...O interactions also occur.
1-[2,6-Dichloro-4-(trifluoromethyl)phenyl]-3,4-dimethylpyrano[2,3-c]pyrazol-6(1H)-one
Authors: Fun Hoong-Kun , Loh Wan-Sin , Sarojini B. K. , Mohan B. J. , Narayana B.
Published: July 2012

In the title compound, C15H9Cl2F3N2O2, the 1,6-dihydropyrano[2,3-c]pyrazole ring system is almost planar, with a maximum deviation of 0.0226 (14) Å, and forms a dihedral angle of 69.90 (6)° with the benzene ring. In the crystal, molecules are linked into a helical chain along thecaxis by C—H...O hydrogen bonds.
(Z)-1-(2-Chlorophenyl)-3-methyl-4-[2-(4-nitrophenyl)hydrazin-1-ylidene]-1H-pyrazol-5(4H)-one
Authors: Bustos Carlos , Escobar-Fuentealba Andrés , Alvarez-Thon Luis , Faundez-Gutierrez Rodrigo , Garland Maria Teresa
Published: July 2012

There are two independent molecules,AandB, in the asymmetric unit of the title compound, C16H12ClN5O3. The relative orientations of the chlorophenyl ring with respect to the pyrazole ring in the two crystallographically independent molecules are different, and their corresponding dihedral angles are −53.3 (2) and 114.09 (18)° in moleculesAandB, respectively. There are two strong intramolecular N—H...O hydrogen bonds, and two weak intramolecular C—H...O and C—H...Cl hydrogen bonds. The crystal packing is constructed by weak C—H...O and N—H...O interactions, and two π–π stacking interactions [centroid–centroid distances = 3.7894 (9) and 3.5719 (10) Å], forming a molecular ladder along theaaxis.
4-(4-Bromophenyl)-8-methyl-2-oxo-1,2,3,4,4a,5,6,7-octahydroquinoline-3-carbonitrile
Authors: Asiri Abdullah M. , Faidallah Hassan M. , Ng Seik Weng , Tiekink Edward R. T.
Published: July 2012

In the title compound, C17H17BrN2O, the N-containing ring adopts an envelope conformation with the C atom carrying the phenyl ring displaced by −0.531 (9) Å from the plane defined by the remaining five atoms (r.m.s. deviation = 0.0099 Å). The benzene ring is almost orthogonal to the ring to which it is attached, the CCN—C—CPh—CPhtorsion angle being −101.3 (7)°. The cyclohexene ring is disordered over two conformations in a statistical ratio. The most prominent interactions in the crystal are pairs of N—H...O hydrogen bonds between inversion-related molecules. The resulting dimers are linked into a three-dimensional architecture by C—H...N, C—H...Br and C—H...π interactions.
4,4′,6,6′-Tetrabromo-2,2′-[(E,E)-ethane-1,2-diylbis(nitrilomethanylylidene)]diphenol
Authors: Kargar Hadi , Kia Reza , Adabi Ardakani Amir , Tahir Muhammad Nawaz
Published: July 2012

The asymmetric unit of the title compound, C16H12Br4N2O2, comprises half of a potential tetradentate Schiff base ligand. The whole molecule is generated by an inversion center located in the middle of the C—C bond of the ethylene segment. There are intramolecular O—H...N hydrogen bonds makingS(6) ring motifs. In the crystal, no significant intermolecular interactions are observed.
2-(2-Nitrophenyl)-1,3-benzothiazole
Authors: Vijayakumar S. , Murugavel S. , Selvakumar R. , Bakthadoss M.
Published: July 2012

In the title compound, C13H8N2O2S, the essentially planar benzothiazole system [maximum deviation = −0.012 (1) Å for the S atom] is oriented at a dihedral angle of 48.3 (1)° with respect to the benzene ring. The nitro group is substantially twisted from the plane of its attached benzene ring [dihedral angle = 52.0 (1)°]. The crystal packing features C—H...O hydrogen bonds, which generateC(6) helical chains propagating along [010]. Weak C—H...π interactions also occur in the crystal.
(E)-1-Nitro-2-(2-nitroprop-1-enyl)benzene
Authors: Shen Li-Li , Li Zhao-Bo , Li Jia-Jia
Published: July 2012

The title compound, C9H8N2O4, adopts anEconformation about the C=C bond. The CHphenyl—Cphenyl—CH—C(—NO2) torsion angle is −57.7 (3)°. The crystal structure features weak intermolecular C—H...O interactions.
Tris(ethylenediamine-κ2N,N′)nickel(II) bis(dimethyl phosphate)
Authors: Rafizadeh Masoud , Saadati Moshtaghin Hamid Reza , Amani Vahid
Published: July 2012

In the title compound, [Ni(C2H8N2)3][O2P(OCH3)2]2, the NiIIatom is six-coordinated in a distorted octahedral geometry by six N atoms from three ethylenediamine ligands. The P atoms of the anions adopt a distorted tetrahedral geometry. In the crystal, intermolecular N—H...O and C—H...O hydrogen bonds link the cations and anions into a three-dimensional network.
4-[(5,5-Dimethyl-3-oxocyclohex-1-enyl)amino]benzenesulfonamide
Authors: Al-Said Mansour S. , Ghorab Mostafa M. , Ghabbour Hazem A. , Quah Ching Kheng , Fun Hoong-Kun
Published: July 2012

In the title compound, C14H18N2O3S, the cyclohexene ring exhibits a distorted half-chair conformation and its mean plane makes a dihedral angle of 46.18 (8)° with the benzene ring. In the crystal, molecules are linkedviaN—H...O, N—H...(O,O) and C—H...O hydrogen bonds, forming a three-dimensional network.
10a-Hydroxy-9-(4-methoxyphenyl)-3,4,5,6,7,8a,9,10a-octahydro-1H-xanthene-1,8(2H)-dione
Authors: Fun Hoong-Kun , Ooi Chin Wei , Reddy B. Palakshi , Vijayakumar V. , Sarveswari S.
Published: July 2012

In the title compound, C20H22O5, the tetrahydropyran, cyclohexene and cyclohexane rings of the xanthene ring system adopt half-chair, half-boat and chair conformations, respectively. The mean plane of the four roughly planar atoms of the tetrahydropyran ring (r.m.s. deviation = 0.111 Å) forms a dihedral angle of 82.91 (4)° with the methoxybenzene group. In the crystal, molecules are linkedviaO—H...O and C—H...O hydrogen bonds into sheets lying parallel to theacplane. The crystal is further consolidated by weak C—H...π interactions.
2,2′-(Piperazine-1,4-diyl)diethanaminium dibenzoate
Authors: Cukrowski Ignacy , Adeyinka Adedapo S. , Liles David C.
Published: July 2012

The asymmetric unit of the title salt C8H22N42+·2C7H5O2−, comprises two independent pairs of half a 2,2′-(piperazine-1,4-diyl)diethanaminium dication plus a benzoate anion. The dications are symmetrical and lie across crystallographic centres of inversion. The crystal structure was refined as a two-component pseudo-merohedral twin using the twin law 001 0-10 100 [he domain fractions are 0.8645 (8) and 0.1355 (8)]. The anions and cations are linked by N—H...O hydrogen bonds and weak N—H...O intermolecular interactions to form infinite two-dimensional networks parallel to [101]. The conformation adopted by the cation in the crystal structure is very similar to that adopted by the same cation in the structures of the 2-hydroxybenzoate [Cukrowskiet al.(2012).Acta Cryst, E68, o2387], the nitrate and the tetrahydrogen pentaborate salts.
(2E)-1-(4,4′′-Difluoro-5′-methoxy-1,1′:3′,1′′-terphenyl-4′-yl)-3-[4-(methylsulfanyl)phenyl]prop-2-en-1-one
Authors: Kant Rajni , Gupta Vivek K. , Kapoor Kamini , Samshuddin S. , Narayana B.
Published: July 2012

In the title compound, C29H22F2O2S, the central benzene ring makes dihedral angles of 45.83 (7), 38.90 (7) and 55.50 (7)° with the two fluoro-substituted benzene rings and the methylsulfanyl-substituted benzene ring, respectively. In the crystal, C—H...O contacts connect the molecules into layers lying perpendicular to thecaxis. In addition, π–π stacking interactions between one of the fluorophenyl groups [centroid–centroid distances = 3.681 (1) and 3.818 (1) Å] are observed.
(Z)-3-(2-Hydroxyethyl)-2-(phenylimino)-1,3-thiazolidin-4-one
Authors: Mohamed Shaaban K. , Abdelhamid Antar A. , Younes Sabry H. H. , Elremaily Mahmoud A. A. , Simpson Jim
Published: July 2012

In the title compound, C11H12N2O2S, the thiazole and phenyl rings are inclined at 56.99 (6)° to one another. The thiazole ring is planar with an r.m.s. deviation for the five ring atoms of 0.0274 Å. The presence of the phenylimine substituent is confirmed with the C=N distance to the thiazole ring of 1.2638 (19) Å. The molecule adopts a Z conformation with respect to this bond. The –OH group of the hydroxyethyl substituent is disordered over two positions with relative occupancies 0.517 (4) and 0.483 (4). In the crystal, O—H...O hydrogen bonds, augmented by C—H...N contacts, form dimers withR22(11) rings and generate chains along thebaxis. Parallel chains are linked in an obverse fashion by weak C—H...S hydrogen bonds. C—H...O hydrogen bonds together with C—H...π contacts further consolidate the structure, stacking molecules along thebaxis.
1,2-Bis[(2,2′:6′,2′′-terpyridin-4′-yl)oxy]ethane
Authors: Nikolayenko Varvara I. , Akerman Matthew P. , Grimmer Craig D. , Reddy Desigan
Published: July 2012

The title compound, C32H24N6O2, has an inversion centre located at the mid-point of the central C—C bond of the diether bridging unit. The terminal pyridine rings are canted relative to the central pyridine ring, with dihedral angles of 12.98 (6) and 26.80 (6)°. The maximum deviation from the eight-atom mean plane, defined by the two bridging O and C atoms and the central pyridine ring, is 0.0383 (10)° for the N atom.
(E)-N′-(5-Bromo-2-hydroxybenzylidene)-2-(4-isobutylphenyl)propanohydrazide
Authors: Mohamed Shaaban K. , Horton Peter N. , Akkurt Mehmet , Albayati Mustafa R. , Abdelhamid Antar A.
Published: July 2012

The title compound, C20H23BrN2O2, containing an ibuprofen core, crystallizes with three independent molecules of similar conformation in the asymmetric unit. In these three molecules, the two benzene rings make dihedral angles of 82.7 (2), 71.2 (2) and 78.0 (3)° with respect to each other. The atoms of the isobutyl groups in two of the molecules are disordered over two positions, with site-occupancy ratios of 0.516 (8):0.484 (8) and 0.580 (8):0.420 (8). In the crystal, molecules are linked by N—H...O, C—H...O and O—H...N hydrogen bonds. Furthermore, C—H...π interactions are also observed.
(Z)-1-(4-Methylphenyl)-2-(phenylsulfonyl)ethanone oxime
Authors: Fun Hoong-Kun , Chia Tze Shyang , Al-Rashood Khalid A. , Abdel-Aziz Hatem A.
Published: July 2012

The molecule of the title compound, C15H15NO3S, has a twisted U-shaped conformation: the twist occurs at the central C—S(=O)2—C—C—C unit and the benzene ring makes a dihedral angle of 28.74 (7)° with the phenyl ring. The S—C—C=N torsion angle is −88.95 (13)°. In the crystal, inversion dimers linked by pairs of O—H...N hydrogen bonds generateR22(6) loops, and C—H...O hydrogen bonds connect the dimers into a three-dimensional network.
Reproductive factors and breast cancer risk in relation to hormone receptor and menopausal status in Japanese women
Authors: Kawai Masaaki , Kakugawa Yoichiro , Nishino Yoshikazu , Hamanaka Yohei , Ohuchi Noriaki , Minami Yuko
Published: July 2012

The associations between menstrual and reproductive factors and breast cancer risk in relation to estrogen/progesterone receptor (ER/PgR) status have been unclear in Japanese women. This case‐control study evaluated these associations, overall and separately, by menopausal status. A total of 1092 breast cancer cases and 3160 controls were selected from among female patients aged 30 years and over admitted to a single hospital in Miyagi Prefecture between 1997 and 2009. The receptor status distribution among the cases (missing: 8.4%) was 571 ER+/PgR+, 133 ER+/PgR−, 24 ER−/PgR+ and 271 ER−/PgR−. Menstrual and reproductive factors were assessed using a self‐administered questionnaire. Polytomous logistic regression and tests for heterogeneity across ER+/PgR+ and ER−/PgR− were conducted. Later age at menarche was significantly associated with a decreased risk of both ER+/PgR+ and ER−/PgR− cancer among women overall (Ptrend = 0.0016 for ER+/PgR+; Ptrend = 0.015 for ER−/PgR−) and among postmenopausal women (Ptrend = 0.012 for ER+/PgR+; Ptrend = 0.0056 for ER−/PgR−). Nulliparity was associated with an increased risk of ER+/PgR+, but not ER−/PgR− cancer among women overall (Pheterogeneity = 0.019) and among postmenopausal women (odds ratio for ER+/PgR+ = 2.56, 95% confidence interval = 1.61–4.07; Pheterogeneity = 0.0095). A longer duration of breastfeeding tended to be associated with a decreased risk in all subtypes among women overall. Later age at menarche has a protective effect against both ER+/PgR+ and ER−/PgR− cancer. However, parity might impact differently on various subtypes of breast cancer. Further studies are needed to clarify the etiology of the rare ER+/PgR− and ER−/PgR+ cancer subtypes.