bluuebunny/crossref_metadata_2025 huggingface dataset:
Do Minority Patients Use Lower Quality Hospitals?
Authors: Gaskin Darrell J. , Spencer Christine S. , Richard Patrick , Anderson Gerard , Powe Neil R. , LaVeist Thomas A.
Published: November 2011

Employing three years of inpatient discharge data from 11 states and inpatient and patient safety quality indicators from the Agency for Healthcare Research and Quality (AHRQ), this paper explored whether minority (black, Hispanic, and Asian) patients used lower quality hospitals. We found that the association between the share of minority patients and hospital quality depended on how quality was measured and varied by race and ethnicity. Hospitals serving Hispanics performed well on most patient safety measures. Higher percentages of all three minority patient groups corresponded to lower quality for only one measure, postoperative sepsis. Our analysis indicates that it is incorrect to generalize that minorities use lower quality hospitals. Analysts and policymakers should be cautious when making generalizations about the overall service quality of hospitals that treat minority patients.
Mean winds, temperatures and the 16- and 5-day planetary waves in the mesosphere and lower thermosphere over Bear Lake Observatory (42° N 111° W)
Authors: Day K. A. , Taylor M. J. , Mitchell N. J.
Published: November 2011

Abstract. Atmospheric temperatures and winds in the mesosphere and lower thermosphere have been measured simultaneously using the Aura satellite and a meteor radar at Bear Lake Observatory (42° N, 111° W). The data presented in this study is from the interval March 2008 to July 2011. The mean winds observed in the summer-time over Bear Lake Observatory show the meridional winds to be equatorward at all heights during April-August and to reach monthly-mean speeds of −12 ms−1. The mean winds are closely related to temperatures in this region of the atmosphere and in the summer the coldest mesospheric temperatures occur about two weeks after the strongest equatorward meridional winds. In other seasons the meridional winds are poleward, reaching monthly-mean values of up to 12 ms−1. The zonal winds are eastward through most of the year and in the summer strong eastward zonal wind shears of up to ~4.5 ms−1 km−1 are present. However, westward winds are observed at the upper heights in winter and sometimes during the equinoxes. Considerable inter-annual variability is observed in the mean winds and temperatures. Comparisons of the observed winds with URAP and HWM-07 reveal some significant differences. Our radar zonal wind observations are generally more weakly eastward than these predicted by the URAP model zonal winds. Considering the radar meridional winds, in comparison to the HWM-07 our observations reveal equatorward flow at all heights in the summer whereas HWM-07 suggests that only weakly equatorward, or even poleward, flows occur at the lower heights. However, the zonal winds observed by the radar and modelled by HWM-07 are generally similar in structure and strength. Signatures of the 16- and 5-day planetary waves are clearly evident in both the radar-wind data and Aura-temperature. Short-lived wave events can reach large amplitudes of up to ~15 ms−1 and 8 K and 20 ms−1 and 10 K for the 16- and 5-day wave, respectively. A clear seasonal and short-term variability are observed in the 16- and 5-day planetary wave amplitudes. The 16-day wave reaches largest amplitude in winter and is also present in summer, but with smaller amplitudes. The 5-day wave reaches largest amplitude in winter and in late summer. An inter-annual variability of the amplitude of the planetary waves are evident in the four years of observations. Some 32 episodes of large-amplitude wave occurrence are investigated and the temperature and wind amplitudes, AT and AW, are found to be related by, AT=0.49 AW and AT=0.58 AW for the 16- and 5-day wave, respectively.
Prioritization of water management under climate change and urbanization using multi-criteria decision making methods
Authors: Yang J.-S. , Chung E.-S. , Kim S.-U. , Kim T.-W. , Kim Y. D.
Published: November 2011

Abstract. This paper quantifies the transformed effectiveness of alternatives for watershed management caused by climate change and urbanization and prioritizes five options using multi-criteria decision making techniques. The climate change scenarios (A1B and A2) were obtained by using a statistical downscaling model (SDSM), and the urbanization scenario by surveying the existing urban planning. The flow and biochemical oxygen demand (BOD) concentration duration curves were derived, and the numbers of days required to satisfy the environmental flow requirement and the target BOD concentration were counted using the Hydrological Simulation Program-Fortran (HSPF) model. In addition, five feasible alternatives were prioritized by using multi-criteria decision making techniques, based on the driving force-pressure-state-impact-response (DPSIR) framework and cost component. Finally, a sensitivity analysis approach for MCDM methods was conducted to reduce the uncertainty of weights. The result indicates that the most sensitive decision criterion is cost, followed by criteria response, driving force, impact, state and pressure in that order. Since it is certain that the importance of cost component is over 0.127, use of the groundwater collected by subway stations will be the most preferred alternative in this application.
Empirical Validation of Outcomes from Training Programs: A Case Study
Authors: Laing Gregory Kenneth , Andrews Paul
Published: November 2011

The purpose of this paper is to demonstrate a method for the validation of training programs. This paper empirically tests variables to provide evidence in support of the outcomes from a training program in a case study. Whilst the ability to identify and measure the outcomes from training programs is highly relevant to all organizations it should be noted that no one set of variables will be applicable to all circumstances. The implications from this paper are that statistical analysis can be used validate measured outcomes of a training program. The method used in this paper provides a technique that has applicability for use over a wide range of training programs. This method is especially significant for Strategic Human Resource Management as a means for providing supporting evidence to justify the outcomes from training programs.
A educação ambiental e o ecoturismo: um binômio necessário
Authors: Alexandre Lillian Maria de Mesquita , Santos Érica Gomes
Published: November 2011

O trabalho aborda aspectos importantes que fundamentam a educação ambiental e o ecoturismo, utilizando-os como ferramenta propulsora de integração entre o homem e o meio ambiente, a fim de um uso sustentável dos recursos naturais, observando como os órgãos competentes se posicionam em relação ao assunto. Dessa forma, será possível desenvolver o processo de sensibilização humana, despertar em cada cidadão a necessidade de uma nova forma de pensar meio ambiente, revendo seu comportamento e criando um senso preservacionista e conservacionista sendo capaz de compreender sua relação com a natureza e de como ambos interagem e dependem um do outro no convívio coletivo. Além disso, foi possível focar na relação entre o ecoturismo e a educação ambiental como ferramentas para a geração do desenvolvimento sustentável numa determinada região. O trabalho teve como base metodológica a pesquisa bibliográfica e a documental, onde os dados levantados foram referentes às questões voltadas à compreensão da educação ambiental e sua relação com o ecoturismo no espaço utilizado pela atividade turística. Foi possível observar que a educação ambiental é um elemento imprescindível para a formação da consciência cidadã, de turistas em sua presença no espaço natural e de uma relação mais harmoniosa entre o turismo e a natureza, haja vista que o ecoturismo se utiliza desde espaço para sua prática.
Viabilidade do turismo no bioma caatinga: Da linguagem do ambiente para a linguagem do ecoturista
Authors: Selva Vanice Santiago Fragoso , Coutinho Solange Fernandes Soares , Souza Tatiana Maria de
Published: November 2011

Considerar que atividades ecoturísticas são indicadas apenas para ambientes terrestres úmidos com exuberante cobertura vegetal e fauna de fácil visualização não corresponde à realidade. Sendo assim, e considerando que um dos objetivos do ecoturismo é a interpretação ambiental, este contribui para a conservação do meio no qual se dá e promove o bem-estar das populações envolvidas, dos ambientes áridos, semi-áridos e subúmidos secos os quais apresentam amplas possibilidades de comportarem atividades ecoturísticas. É o caso do semi-árido brasileiro, domínio do bioma Caatinga, endêmico do Brasil e hoje Reserva da Biosfera, que se apresenta fortemente diversificado em resposta às suas especificidades locais. Nesse contexto, o trabalho busca ressaltar a relevância de compreensão das múltiplas interações que se dão entre os diversos elementos componentes de uma trilha ecoturística a partir da fitofisionomia e biota do bioma, tomando como objeto de estudo o ambiente da caatinga na região de Xingó. A pesquisa foi realizada a partir da revisão bibliográfica e observação de duas trilhas no Pólo Ecoturístico Canyon do Rio São Francisco, no sertão de Alagoas e de Sergipe, destacando-se as características das espécies vegetais representativas do ambiente semi-árido. Foi observado o porte, a densidade, o tamanho, a cor e a textura das folhas, o tipo e forma dos caules e das raízes, a estratificação, a maior ou menor presença de ervas, arbustos e árvores para se ter um real conhecimento das potencialidades da caatinga para a interpretação ambiental e a forma como os condutores e ecoturistas exploram as trilhas. Os resultados apontam que a interpretação dos elementos que compõem o ambiente não é explorada utilizando-se as interações existentes, a fisionomia das diferentes espécies ou o que condiciona a presença do bioma na região, mas, apenas características de algumas espécies e o uso de algumas plantas. Apontam ainda para as necessidades relacionadas ao planejamento, gestão e monitoramento da atividade, incluindo investimento na qualificação de condutores e sensibilização dos praticantes dessa forma de fazer turismo e amplia a discussão para a viabilidade do ecoturismo como forma de uso sustentável do ambiente semi-árido possibilitando, inclusive, a recuperação de áreas degradadas.
Interpretação ambiental e espeleoturismo: estudo sobre o Parque Estadual Turístico do Alto Ribeira
Authors: Silva Netto Joviniano Pereira da , Hanai Frederico Yuri
Published: November 2011

Inserido na Reserva da Biosfera da Mata Atlântica e considerado uma área-piloto pela UNESCO, o Parque Estadual Turístico do Alto Ribeira (PETAR) constitui-se numa das Unidades de Conservação mais conhecidas e antigas do Estado de São Paulo, abrigando mais de trezentas cavidades naturais cadastradas e despertando o crescente interesse do Espeleoturismo e Ecoturismo. O aumento da visitação e o fato das cavidades, por vezes, coincidirem com ecossistemas frágeis provocam impactos negativos sobre o ambiente, podendo ser evitados ou diminuídos por meio de alternativas de procedimentos como a percepção e a conscientização ambientais. A capacidade de apreensão – aqui denominada “percepção” - das formas de vida, dos ornamentos, e do próprio ambiente cavernícola acarreta em interpretação, sendo que os valores, referências, emoções, expectativas e interesses do visitante influenciam diretamente no que será percebido. A conscientização ambiental gerada a partir da interpretação pode definir o possível grau de impacto que a área visitada sofrerá. Embora o PETAR possua infra-estrutura (portarias, regulamentação e diretrizes básicas para o turismo) que possibilite um fácil acesso ao remanescente de Mata Atlântica e a muitas cavidades naturais, ainda faz-se necessário um programa freqüente constituído por palestras, dinâmicas, e monitoramentos (promovidos pela administração do parque) que visem informar e convencer os visitantes por meio da educação ambiental, da real importância de se preservar os ambientes, favorecendo uma harmônica relação com a natureza e principalmente, conduzindo-os a um patamar de educação ambiental em que efetivamente sirva para a conservação ecológica das áreas naturais visitadas. Desta forma, o trabalho apresenta algumas considerações sobre como estimular a percepção e a interpretação ambiental em cavernas com potencial turístico, tendo como local de estudo o PETAR.
Lanthanide Polyoxocationic Complexes: Experimental and Theoretical Stability Studies and Lewis Acid Catalysis
Authors: El Moll Hani , Nohra Brigitte , Mialane Pierre , Marrot Jérôme , Dupré Nathalie , Riflade Benoît , Malacria Max , Thorimbert Serge , Hasenknopf Bernold , Lacôte Emmanuel , Aparicio Pablo A. , López Xavier , Poblet Josep M. , Dolbecq Anne
Published: November 2011

The [ε‐PMoV8MoVI4O36(OH)4{LnIII(H2O)}4]5+ (Ln=La, Ce, Nd, Sm) polyoxocations, called εLn4, have been synthesized at room temperature as chloride salts soluble in water, MeOH, EtOH, and DMF. Rare‐earth metals can be exchanged, and 31P NMR spectroscopic studies have allowed a comparison of the affinity of the reduced {ε‐PMo12} core, thus showing that the LaIII ions have the highest affinity and that rare earths heavier than EuIII do not react with the ε‐Keggin polyoxometalate. DFT calculations provide a deeper insight into the geometries of the systems studied, thereby giving more accurate information on those compounds that suffer from disorder in crystalline form. It has also been confirmed by the hypothetical La→Gd substitution reaction energy that Ln ions beyond Eu cannot compete with La in coordinating the surface of the ε‐Keggin molybdate. Two of these clusters (Ln=La, Ce) have been tested to evidence that such systems are representative of a new efficient Lewis acid catalyst family. This is the first time that the catalytic activity of polyoxocations has been evaluated.
Unexpected Influence of Stereochemistry on the Cytotoxicity of Highly Efficient TiIV Salan Complexes: New Mechanistic Insights
Authors: Manna Cesar M. , Armony Gad , Tshuva Edit Y.
Published: November 2011

The effect of stereochemistry on the cytotoxicity of highly active and hydrolytically stable N‐methylated TiIV salan complexes is reported. Four bis(isopropoxo) complexes incorporating N‐methylated salan ligands with different aromatic substitution patterns have been prepared in racemic and optically active forms for the first time by ligand‐to‐metal chiral induction from trans‐diaminocyclohexyl‐based chiral ligands. The configuration of the metal center that derives from that of the ligand has an enormous influence on cytotoxicity, with the racemic mixture mostly being more active than the single enantiomers that are of either similar or different activity. This implies that the active species is a salan‐bound heterochiral polynuclear compound, interacting with a chiral target. Four additional complexes of achiral salan and chiral labile sec‐butoxo ligands, analyzed as racemic and as homochiral, revealed no influence of stereochemistry, supporting early dissociation of the labile ligands to give the polynuclear products.
The RABL5 homolog IFT22 regulates the cellular pool size and the amount of IFT particles partitioned to the flagellar compartment in Chlamydomonas reinhardtii
Authors: Silva David A. , Huang Xiaomeng , Behal Robert H. , Cole Douglas G. , Qin Hongmin
Published: November 2011

Cilia and flagella, sensory and motile structures protruding from the cell body, rely on the continuous bidirectional traffic of intraflagellar transport (IFT) particles to ferry flagellar precursors into flagella for assembly. Cells synthesize a large pool of IFT particle proteins in the cell body, but only a small portion engages in active transport within the flagella at any given time. The atypical small G protein Rab‐like 5 (RABL5) has been shown to move in an IFT‐like manner in the flagella, but its function in ciliogenesis is controversial. In this report, we demonstrate that IFT22, the Chlamydomonas reinhardtii homolog of RABL5, is a bona fide IFT particle complex B subunit. Although the amount of IFT22 remains unaffected by depletion of either complex A or B, depletion of IFT22 leads to a smaller pool of both complex A and B. Strikingly, the smaller cellular pool of IFT particles does not lead to a reduced distribution of IFT particles to flagella. Instead, the amount of IFT particle proteins, including IFT22 itself, increase in the flagella. Moreover, cells over‐expressing IFT22 also accumulate IFT particles in their flagella. Taken together, these data indicate that, in C. reinhardtii, IFT22 controls the cellular levels of both complex A and B, thus plays a critical role in determining the cellular availability of IFT particles. In addition, although IFT22 may not directly carry any precursors for flagellar assembly, it controls how many IFT particles participate in ferrying precursors into flagella. © 2011 Wiley Periodicals, Inc.
Electronic Effects of Ligands on the Cobalt(II)–Porphyrin‐Catalyzed Direct C–H Arylation of Benzene
Authors: Chan Tek Long , To Ching Tat , Liao Bei‐Sih , Liu Shiuh‐Tzung , Chan Kin Shing
Published: November 2011

The electronic effects of the porphyrin ligand on the cobalt(II)‐porphyrin‐catalyzed direct C–H arylation of benzene with 4‐iodotoluene were explored. The investigation was facilitated by the easy preparation of various substituted porphyrin ligands. The reaction rates were found to be dependent on the electron richness of the cobalt(II)–porphyrins. Such effects are consistent with the electronic influences on the rate‐determining aryl iodide bond cleavage.
Requirement of phospholipase C and protein kinase C in cholecystokinin‐mediated facilitation of NMDA channel function and anxiety‐like behavior
Authors: Xiao Zhaoyang , Jaiswal Manoj K. , Deng Pan‐Yue , Matsui Toshimitsu , Shin Hee‐Sup , Porter James E. , Lei Saobo
Published: November 2011

Although cholecystokinin (CCK) has long been known to exert anxiogenic effects in both animal anxiety models and humans, the underlying cellular and molecular mechanisms are ill‐defined. CCK interacts with CCK‐1 and CCK‐2 receptors resulting in up‐regulation of phospholipase C (PLC) and protein kinase C (PKC). However, the roles of PLC and PKC in CCK‐mediated anxiogenic effects have not been determined. We have shown previously that CCK facilitates glutamate release in the hippocampus especially at the synapses formed by the perforant path and dentate gyrus granule cells via activations of PLC and PKC. Here we further demonstrated that CCK enhanced NMDA receptor function in dentate gyrus granule cells via activation of PLC and PKC pathway. At the single‐channel level, CCK increased NMDA single‐channel open probability and mean open time, reduced the mean close time, and had no effects on the conductance of NMDA channels. Because elevation of glutamatergic functions results in anxiety, we explored the roles of PLC and PKC in CCK‐induced anxiogenic actions using the Vogel Conflict Test (VCT). Our results from both pharmacological approach and knockout mice demonstrated that microinjection of CCK into the dentate gyrus concentration‐dependently increased anxiety‐like behavior via activation of PLC and PKC. Our results provide a novel unidentified signaling mechanism whereby CCK increases anxiety. © 2011 Wiley Periodicals, Inc.
A possible overestimation of the effect of acetylation on lysine residues in KQ mutant analysis
Authors: Fujimoto Hirofumi , Higuchi Mariko , Koike Manabu , Ode Hirotaka , Pinak Miroslav , Bunta Juraj Kotulic , Nemoto Toshiyuki , Sakudoh Takashi , Honda Naoko , Maekawa Hideaki , Saito Kimiaki , Tsuchida Kozo
Published: November 2011

Acetylation of lysine residues, one of the most common protein post‐transcriptional modifications, is thought to regulate protein affinity with other proteins or nucleotides. Experimentally, the effects of acetylation have been studied using recombinant mutants in which lysine residues (K) are substituted with glutamine (Q) as a mimic of acetyl lysine (KQ mutant), or with arginine (R) as a mimic of nonacetylated lysine (KR mutant). These substitutions, however, have not been properly validated. The effects lysine acetylation on Ku, a multifunctional protein that has been primarily implicated in DNA repair and cell survival, are characterized herein using a series of computer simulations. The binding free energy was reduced in the KQ mutant, while the KR mutant had no effect, which is consistent with previous experimental results. Unexpectedly, the binding energy between Ku and DNA was maintained at almost the same level as in the wild type protein despite full acetylation of the lysine residues. These results suggest that the effects of acetylation may be overestimated when the KQ mutant is used as a mimic of the acetylated protein. © 2011 Wiley Periodicals, Inc. J Comput Chem 2012
Protective Effect of Calamintha officinalis Moench Leaves against Alcohol‐induced Gastric Mucosa Injury in Rats. Macroscopic, Histologic and Phytochemical Analysis
Authors: Monforte M. T. , Lanuzza F. , Pergolizzi S. , Mondello F. , Tzakou O. , Galati E. M.
Published: November 2011

Calamintha officinalis Moench (Lamiaceae) is an aromatic plant used since ancient times for its preservative and medicinal properties. The plant, known as ‘Mentuccia’ in Central Italy, is used in cooking as an aromatizant and to impart aroma and flavour to food. The methanol extract of the leaves was subjected to phytochemical and biological investigations. The extract contains polyphenols, catechic tannins and terpenes and shows radical scavenger activity. By means of HPLC analysis, eriocitrin, eriodyctiol, acacetin, linarin, benzoic acid and some phenolic acids, such as caffeic, chlorogenic, p‐coumaric, were determined. The gastroprotective activity of the extract was investigated using ethanol‐induced ulcer in rats, with sucralfate as a reference drug. Samples of gastric mucosa, stained by PAS and haematoxylin/eosin, were observed by light microscopy. The efficacy of the extract was comparable to that of the reference drug.

Probably the gastroprotective effect depends on a synergistic action of all the compounds occurring in C. officinalis leaves, even if the antioxidant potential of the leaves plays an important role by removing damaging agents from the gastric mucosa. Copyright © 2011 John Wiley & Sons, Ltd.
Barx2 Is Expressed in Satellite Cells and Is Required for Normal Muscle Growth and Regeneration
Authors: Meech Robyn , Gonzalez Katie N. , Barro Marietta , Gromova Anastasia , Zhuang Lizhe , Hulin Julie-Ann , Makarenkova Helen P.
Published: November 2011

Muscle growth and regeneration are regulated through a series of spatiotemporally dependent signaling and transcriptional cascades. Although the transcriptional program controlling myogenesis has been extensively investigated, the full repertoire of transcriptional regulators involved in this process is far from defined. Various homeodomain transcription factors have been shown to play important roles in both muscle development and muscle satellite cell-dependent repair. Here, we show that the homeodomain factor Barx2 is a new marker for embryonic and adult myoblasts and is required for normal postnatal muscle growth and repair. Barx2 is coexpressed with Pax7, which is the canonical marker of satellite cells, and is upregulated in satellite cells after muscle injury. Mice lacking the Barx2 gene show reduced postnatal muscle growth, muscle atrophy, and defective muscle repair. Moreover, loss of Barx2 delays the expression of genes that control proliferation and differentiation in regenerating muscle. Consistent with the in vivo observations, satellite cell-derived myoblasts cultured from Barx2−/− mice show decreased proliferation and ability to differentiate relative to those from wild-type or Barx2+/− mice. Barx2−/− myoblasts show reduced expression of the differentiation-associated factor myogenin as well as cell adhesion and matrix molecules. Finally, we find that mice lacking both Barx2 and dystrophin gene expression have severe early onset myopathy. Together, these data indicate that Barx2 is an important regulator of muscle growth and repair that acts via the control of satellite cell proliferation and differentiation.

Disclosure of potential conflicts of interest is found at the end of this article.
Guided Migration of Neural Stem Cells Derived from Human Embryonic Stem Cells by an Electric Field
Authors: Feng Jun-Feng , Liu Jing , Zhang Xiu-Zhen , Zhang Lei , Jiang Ji-Yao , Nolta Jan , Zhao Min
Published: November 2011

Small direct current (DC) electric fields (EFs) guide neurite growth and migration of rodent neural stem cells (NSCs). However, this could be species dependent. Therefore, it is critical to investigate how human NSCs (hNSCs) respond to EF before any possible clinical attempt. Aiming to characterize the EF-stimulated and guided migration of hNSCs, we derived hNSCs from a well-established human embryonic stem cell line H9. Small applied DC EFs, as low as 16 mV/mm, induced significant directional migration toward the cathode. Reversal of the field polarity reversed migration of hNSCs. The galvanotactic/electrotactic response was both time and voltage dependent. The migration directedness and distance to the cathode increased with the increase of field strength. (Rho-kinase) inhibitor Y27632 is used to enhance viability of stem cells and has previously been reported to inhibit EF-guided directional migration in induced pluripotent stem cells and neurons. However, its presence did not significantly affect the directionality of hNSC migration in an EF. Cytokine receptor [C-X-C chemokine receptor type 4 (CXCR4)] is important for chemotaxis of NSCs in the brain. The blockage of CXCR4 did not affect the electrotaxis of hNSCs. We conclude that hNSCs respond to a small EF by directional migration. Applied EFs could potentially be further exploited to guide hNSCs to injured sites in the central nervous system to improve the outcome of various diseases.

Disclosure of potential conflicts of interest is found at the end of this article.
Indonesia's Rise: Implications for Asia and Europe
Authors: Islam Shada
Published: November 2011

The European Union must devote more time and attention to developing a strong strategic relationship with Indonesia, one of Asia's most dynamic economies, a vibrant democracy and a moderate Muslim nation. Currently courted by the US, China and Australia, Indonesia is looking for a closer partnership with Europe. EU policymakers must seize the opportunity and act rapidly to engage Jakarta, a move which will also boost Europe's standing in the rest of Asia.
Nonaddictive instrumental drug use: Theoretical strengths and weaknesses
Authors: Goudie Andrew J. , Gullo Matthew J. , Rose Abigail K. , Christiansen Paul , Cole Jonathan C. , Field Matt , Sumnall Harry
Published: November 2011

The potential to instrumentalize drug use based upon the detection of very many different drug states undoubtedly exists, and such states may play a role in psychiatric and many other drug uses. Nevertheless, nonaddictive drug use is potentially more parsimoniously explained in terms of sensation seeking/impulsivity and drug expectations. Cultural factors also play a major role in nonaddictive drug use.
The planet companion around β Pictoris
Authors: Lagrange Anne-Marie , Bonnefoy Mickaël , Chauvin Gael , Apai Daniel , Ehrenreich David , Boccaletti Anthony , Gratadour Damien , Rouan Daniel , Mouillet David , Lacour Sylvestre , Kasper Markus
Published: November 2011

The β Pic disk of dust and gas has been regarded as the prototype of young planetary systems since the 1980s and has revealed over the years an impressive amount of indirect signs pointing toward the presence of at least one giant planet. We present here the recently detected first giant planet around this star. We show how this planet could explain some very peculiar features of the star environment (disk, spectroscopic variability), and how it constrains the scenarios of planetary system formation (timescales, mechanisms).
Planet masses and radii from physical principles
Authors: Wuchterl Guenther
Published: November 2011

Masses and radii are the primary observables to characterize exoplanets today. A self-consistent theoretical approach is presented that allows to calculate mass- and radius-distributions of exoplanet populations from basic physical principles and avoids the usual parametrisation of a multitude of processes.
High-resolution simulations of planetesimal formation in turbulent protoplanetary discs
Authors: Johansen Anders , Klahr Hubert , Henning Thomas
Published: November 2011

We present high resolution computer simulations of dust dynamics and planetesimal formation in turbulence triggered by the magnetorotational instability. Particles representing approximately meter-sized boulders clump in large scale overpressure regions in the simulation box. These overdensities readily contract due to the combined gravity of the particles to form gravitationally bound clusters with masses ranging from a few to several ten times the mass of the dwarf planet Ceres. Gravitationally bound clumps are observed to collide and merge at both moderate and high resolution. The collisional products form the top end of a distribution of planetesimal masses ranging from less than one Ceres mass to 35 Ceres masses. It remains uncertain whether collisions are driven by dynamical friction or underresolution of clumps.
The properties of super-Earth atmospheres
Authors: Kempton Eliza M. R.
Published: November 2011

Extrasolar super-Earths likely have a far greater diversity in their atmospheric properties than giant planets. Super-Earths (planets with masses between 1 and 10 M⊕) lie in an intermediate mass regime between gas/ice giants like Neptune and rocky terrestrial planets like Earth and Venus. While some super-Earths (especially the more massive ones) may retain large amounts of hydrogen either from accretion processes or subsequent surface outgassing, other super-Earths should have atmospheres composed of predominantly heavier molecules, similar to the atmospheres of the rocky planets and moons of our Solar System. Others still may be entirely stripped of their atmospheres and remain as bare rocky cores. Of the two currently known transiting super-Earths one (GJ 1214b) likely falls into the former category with a thick atmosphere, while the other (CoRoT-7b) falls into the latter category with a very thin or nonexistent atmosphere. I review some of the theoretical work on super-Earth atmospheres, and I present methods for determining the bulk composition of a super-Earth atmosphere.
Hamiltonian model of capture into mean motion resonance
Authors: Mustill Alexander J. , Wyatt Mark C.
Published: November 2011

Mean motion resonances are a common feature of both our own Solar System and of extrasolar planetary systems. Bodies can be trapped in resonance when their orbital semi-major axes change, for instance when they migrate through a protoplanetary disc. We use a Hamiltonian model to thoroughly investigate the capture behaviour for first and second order resonances. Using this method, all resonances of the same order can be described by one equation, with applications to specific resonances by appropriate scaling. We focus on the limit where one body is a massless test particle and the other a massive planet. We quantify how the the probability of capture into a resonance depends on the relative migration rate of the planet and particle, and the particle's eccentricity. Resonant capture fails for high migration rates, and has decreasing probability for higher eccentricities, although for certain migration rates, capture probability peaks at a finite eccentricity. We also calculate libration amplitudes and the offset of the libration centres for captured particles, and the change in eccentricity if capture does not occur. Libration amplitudes are higher for larger initial eccentricity. The model allows for a complete description of a particle's behaviour as it successively encounters several resonances. The model is applicable to many scenarios, including (i) Planet migration through gas discs trapping other planets or planetesimals in resonances; (ii) Planet migration through a debris disc; (iii) Dust migration through PR drag. The Hamiltonian model will allow quick interpretation of the resonant properties of extrasolar planets and Kuiper Belt Objects, and will allow synthetic images of debris disc structures to be quickly generated, which will be useful for predicting and interpreting disc images made with ALMA, Darwin/TPF or similar missions. Full details can be found in Mustill & Wyatt (2011).
Monitoring and analyzing exoplanetary transits from Argentina
Authors: Fernández-Lajús Eduardo , Miguel Yamila , Fortier Andrea , Di Sisto Romina P.
Published: November 2011

Photometric observations of transits can be used to derive physical and orbital parameters of the system, like the planetary and stellar radius, orbital inclination and mean density of the star. Furthermore, monitoring possible periodic variations in transit timing of planets is important, since small changes can be caused by the presence of other planets or moons in the system. On the other hand, long term changes in the transit length can be due to the orbital precession of the planets. For these reasons we started an observational program dedicated to observe transits of known exoplanets with the aim of contributing to a better understanding of these planetary systems. In this work we present our first results obtained using the observational facilities in Argentina including the 2.15 telescope at CASLEO.
Non-convergence of the critical cooling timescale for fragmentation of self-gravitating discs
Authors: Meru Farzana , Bate Matthew R.
Published: November 2011

We carry out a resolution study on the fragmentation boundary of self-gravitating discs. We perform three-dimensional Smoothed Particle Hydrodynamics (SPH) simulations of discs to determine whether the critical value of the cooling timescale in units of the orbital timescale, βcrit, converges with increasing resolution. Using particle numbers ranging from 31,250 to 16 million (the highest resolution simulations to date) we do not find convergence. Instead, fragmentation occurs for longer cooling timescales as the resolution is increased. These results certainly suggest that βcrit is larger than previously thought. However, the absence of convergence also questions whether or not a critical value exists. In light of these results, we caution against using cooling timescale or gravitational stress arguments to deduce whether gravitational instability may or may not have been the formation mechanism for observed planetary systems.
A survey of M stars in the field of view of Kepler space telescope
Authors: Oshagh Mahmoudreza , Haghighipour Nader , Santos Nuno C.
Published: November 2011

M dwarfs constitute more than 70% of the stars in the solar neighborhood. They are cooler and smaller than Sun-like stars and have less-massive disks which suggests that planets around these stars are more likely to be Neptune-size or smaller. The transit depths and transit times of planets around M stars are large and well-matched to the Kepler temporal resolution. As a result, M stars have been of particular interest for searching for planets in both radial velocity and transit photometry surveys. We have recently started a project on searching for possible planet-hosting M stars in the publicly available data from Kepler space telescope. We have used four criteria, namely, the magnitude, proper motion, H-Ks and J-H colors, and searched for M stars in Q0 and Q1 data sets. We have been able to find 108 M stars among which 54 had not been previously identified among Kepler's targets. We discuss the details of our selection process and present the results.
Role of partial miscibility on pressure buildup due to constant rate injection of CO2 into closed and open brine aquifers
Authors: Mathias Simon A. , Gluyas Jon G. , González Martínez de Miguel Gerardo J. , Hosseini Seyyed A.
Published: November 2011

This work extends an existing analytical solution for pressure buildup because of CO2 injection in brine aquifers by incorporating effects associated with partial miscibility. These include evaporation of water into the CO2 rich phase and dissolution of CO2 into brine and salt precipitation. The resulting equations are closed‐form, including the locations of the associated leading and trailing shock fronts. Derivation of the analytical solution involves making a number of simplifying assumptions including: vertical pressure equilibrium, negligible capillary pressure, and constant fluid properties. The analytical solution is compared to results from TOUGH2 and found to accurately approximate the extent of the dry‐out zone around the well, the resulting permeability enhancement due to residual brine evaporation, the volumetric saturation of precipitated salt, and the vertically averaged pressure distribution in both space and time for the four scenarios studied. While brine evaporation is found to have a considerable effect on pressure, the effect of CO2 dissolution is found to be small. The resulting equations remain simple to evaluate in spreadsheet software and represent a significant improvement on current methods for estimating pressure‐limited CO2 storage capacity.
Modeling the action-potential-sensitive nonlinear-optical response of myelinated nerve fibers and short-term memory
Authors: Shneider M. N. , Voronin A. A. , Zheltikov A. M.
Published: November 2011

The Goldman–Albus treatment of the action-potential dynamics is combined with a phenomenological description of molecular hyperpolarizabilities into a closed-form model of the action-potential-sensitive second-harmonic response of myelinated nerve fibers with nodes of Ranvier. This response is shown to be sensitive to nerve demyelination, thus enabling an optical diagnosis of various demyelinating diseases, including multiple sclerosis. The model is applied to examine the nonlinear-optical response of a three-neuron reverberating circuit—the basic element of short-term memory.
Oscillations in the spatial distribution of current in nanotubes and nanowires
Authors: Fernandes Nt A. R. , Otálora J. A. , Vargas P. , d’Albuquerque e Castro J.
Published: November 2011

The electronic transport process in nanotubes and nanowires along their axes is investigated. Attention is focused on the distribution of current within the structure, which is found to exhibit well-defined oscillations in the radial direction. The case in which an external magnetic field parallel to the nanowire or nanotube axis is applied to the system is also considered. In all cases, the origin of the oscillations and corresponding periods are identified. Effects of this behavior on the transport properties of nanotubes and nanowires are noted.
Effects of human chorionic gonadotrophin administration on Day 5 after oestrus on corpus luteum characteristics, circulating progesterone and conceptus elongation in cattle
Authors: Rizos D. , Scully S. , Kelly A. K. , Ealy A. D. , Moros R. , Duffy P. , Al Naib A. , Forde N. , Lonergan P.
Published: November 2011

The aim of the present study was to test the hypothesis that elevated concentrations of progesterone (P4) resulting from the induction of an accessory corpus luteum (CL) by human chorionic gonadotrophin (hCG) administration on Day 5 after oestrus would lead to advanced conceptus elongation on Day 14 following embryo transfer on Day 7. The oestrous cycles of cross-bred beef heifers were synchronised and animals were randomly assigned to receive either of two treatments: (1) intramuscular injection of 3000 IU hCG on Day 5 after oestrus (n = 14); or (2) intramuscular injection of saline on Day 5 after oestrus (n = 13). Ovaries were scanned daily by transrectal ultrasonography to assess CL development. Serum concentrations of P4 were determined from daily blood samples collected from the jugular vein. In vitro-produced bovine blastocysts were transferred to synchronised recipients on Day 7 after oestrus (n = 15 blastocysts per recipient). Heifers were killed on Day 14 after oestrus and the uterus was flushed to recover the embryos. Injection of hCG on Day 5 induced ovulation of the dominant follicle in all treated heifers and increased the total area of luteal tissue on the ovary, which was associated with a significant increase (P < 0.001) in serum concentrations of P4 from Day 7 to Day 14. Positive associations were detected between circulating P4 with CL area (within-day correlations ranging from r = 0.45 to r = 0.67) and total area of luteal tissue (within-day correlations ranging from r = 0.65 to r = 0.86) Administration of hCG did not affect the proportion of Day 14 conceptuses recovered. However, compared with the control group, hCG-treated heifers had increased conceptus length (3.91 ± 1.23 vs 5.57 ± 1.02 mm, respectively; P = 0.06), width (1.00 ± 0.06 vs 1.45 ± 0.05 mm, respectively; P = 0.002) and area (5.71 ± 0.97 vs 8.31 ± 0.83, respectively; P = 0.02). Although numerically greater, mean interferon-τ (IFNT) production in vitro did not differ significantly (P = 0.54) between embryos recovered from hCG-treated and control heifers. In contrast, there was a strong positive correlation between individual embryo length (r = 0.76; P < 0.001) and individual embryo area (r = 0.72; P < 0.001) and IFNT production. In conclusion, administration of hCG on Day 5 after oestrus resulted in the formation of an accessory CL and hypertrophy of the original CL, the result of which was an increase in P4 concentrations from Day 7 onwards. These elevated P4 concentrations were associated with an increased conceptus area. Furthermore, conceptus size was highly correlated with IFNT secretion in vitro.
SKP1 is involved in abscisic acid signalling to regulate seed germination, stomatal opening and root growth in Arabidopsis thaliana
Authors: LI CHIJUN , LIU ZUOJUN , ZHANG QIRUI , WANG RUOZHONG , XIAO LANGTAO , MA HONG , CHONG KANG , XU YUNYUAN
Published: November 2011

Abscisic acid (ABA) regulates many aspects of plant development, including seed dormancy and germination, root growth and stomatal closure. Plant SKP1 proteins are subunits of the SCF complex E3 ligases, which regulate several phytohormone signalling pathways through protein degradation. However, little is known about SKP1 proteins participating in ABA signalling. Here, we report that the overexpression of Triticum aestivum SKP1‐like 1 (TSK1) in Arabidopsis thaliana (Arabidopsis) resulted in delayed seed germination and hypersensitivity to ABA. The opening of stomatal guard cells and the transcription of several ABA‐responsive genes were affected in transgenic plants. In contrast, Arabidopsis skp1‐like 1 (ask1)/ask1 ASK2/ask2 seedlings exhibited reduced ABA sensitivity. Furthermore, the transcription of ASK1 and ASK2 was down‐regulated in abi1‐1 and abi5‐1 mutants compared with that in wild type. ASK1 or ASK2 overexpression could rescue or partially rescue the ABA insensitivity of abi5‐1 mutants, respectively. Our work demonstrates that SKP1 is involved in ABA signalling and that SKP1‐like genes may positively regulate ABA signalling by SCF‐mediated protein degradation.
Animal fibre: The forgotten nutrient in strict carnivores? First insights in the cheetah
Authors: Depauw S. , Hesta M. , Whitehouse‐Tedd K. , Vanhaecke L. , Verbrugghe A. , Janssens G. P. J.
Published: November 2011

As wild felids are obligate carnivores, it is likely that poorly enzymatically digestible animal tissues determine hindgut fermentation, instead of plant fibre. Therefore, faecal concentrations of short‐chain fatty acids (SCFA, including branched‐chain fatty acids, BCFA), indole and phenol were evaluated in 14 captive cheetahs, fed two different diets differing in proportion of poorly enzymatically digestible animal tissue. Using a cross‐over design, the cheetahs were fed exclusively whole rabbit or supplemented beef for 1 month each. Feeding whole rabbit decreased faecal propionic (p < 0.001) and butyric (p = 0.013) acid concentrations, yet total SCFA was unaltered (p = 0.146). Also, a remarkably higher acetic acid to propionic acid ratio (p = 0.013) was present when fed whole rabbit. Total BCFA (p = 0.011) and putrefactive indole (p = 0.004) and phenol (p = 0.002) were lower when fed whole rabbit. Additionally, serum indoxyl sulphate, a toxic metabolite of indole, was analysed and showed a quadratic decrease (p = 0.050) when fed whole rabbit. The divergent SCFA ratios and the decrease in putrefaction when fed whole rabbit could be caused by the presence of undigested tissue, such as skin, bone and cartilage, that might have fibre‐like functions. The concept ofanimal fibreis an unexplored area of interest relevant to gastrointestinal health of captive cheetahs and likely other felids.
Perioperative opiate requirements in children with previous opiate infusion
Authors: Fanning Jeffrey J. , Stucke Astrid G. , Christensen Melissa A. , Cassidy Laura D. , Berens Richard J.
Published: November 2011

Background:  Critically ill children often require continuous opiate infusions. Tolerance may develop requiring a weaning strategy to prevent withdrawal symptoms. These children may also require subsequent surgical procedures. This is the first study to investigate whether previously opiate‐tolerant patients require higher doses of opiates for adequate pain management perioperatively.

Methods:  A retrospective study was conducted at a tertiary children’s hospital to investigate whether children previously exposed to continuous opiates for 10 or more days with subsequent weaning from those opiates will have similar or increased perioperative opiate requirements when compared to opioid‐naïve controls. Study patients included 31 children with previous continuous opiate exposure for 10 or more days followed by weaning and without signs of withdrawal for at least 72 h prior to the surgical procedure. Excluded were patients over 18 years of age, those whose surgical procedures would be unlikely to require perioperative opiates, oncological patients, burn patients, neurologically devastated patients, and patients who received regional anesthesia in addition to perioperative narcotics. The control group consisted of 31 age‐ and case‐matched opiate‐naïve patients who underwent a surgical procedure during a similar time frame as the study patient. The medication administration record was reviewed for the length of continuous opiate exposure, date of last opiate use prior to a subsequent surgical procedure, and opiate use during the perioperative period. Opiate use was calculated as morphine equivalents per kilogram body weight (MSEQ·kg−1). The Wilcoxon rank sum test was used for univariate comparisons between matched pairs, and P‐values <0.05 were considered statistically significant.

Results:  The perioperative opiate requirements in opiate‐exposed patients (median, interquartile range: 0.14, 0.08–0.25 MSEQ·kg−1) were not significantly different from opiate‐naïve patients (median, interquartile range 0.10, 0.05–0.2 MSEQ·kg−1, P = 0.19). Pain scores indicated that patients were generally comfortable in the perioperative period.

Conclusions:  The perioperative opiate requirements of pediatric patients who were successfully weaned after prolonged opiate use were similar to opiate‐naïve patients. A history of prolonged opiate use alone does not necessitate special pain management for future procedures.