bluuebunny/crossref_metadata_2025 huggingface dataset:
Parâmetros físicos do solo relacionados com o avanço da frente de molhamento
Authors: Souza Filho Paulo da S. e , Heldwein Arno B. , Zamberlan João F. , Corrêa Henrique C.
Published: March 2013

Este estudo visou contribuir, no âmbito metodológico, nas áreas da ciência do solo e da irrigação, notadamente na microirrigação na obtenção "in situ" de parâmetros físicos e hídricos do Argissolo Vermelho Distrófico arênico (PVd). Foi projetado um sistema "multigotejador" cuja aplicação está vinculada aos princípios do "Método do Gotejador" na obtenção da condutividade hidráulica K(h) e da curva de retenção de água no solo q(h). Vazões aplicadas de 2, 4 e 8 L h-1 e suas respectivas áreas de molhamento e de saturação, foram medidas no momento do equilíbrio dinâmico. O valor médio de sorptividade calculado foi de 2,68 cm h-0,5, sendo obtidos os valores de h = 2,22, b = 0,44 e hw = -2,29 cm de H2O. Usando-se os valores dos parâmetros do solo, a curva característica de retenção de água no solo (CCRAS) e a função da condutividade hidráulica em função do conteúdo de água do solo, foram estimadas e representadas graficamente. A curva característica obtida com dados experimentais de campo não foi igual àquela obtida em laboratório, conforme metodologia padrão, mas foi possível obter uma função exponencial que permite corrigir os valores da umidade volumétrica do solo.
Escoamento superficial em Latossolo Amarelo distrófico típico sob diferentes agroecossistemas no nordeste paraense
Authors: Costa Cristiane F. G. da , Figueiredo Ricardo de O. , Oliveira Francisco de A. , Santos Izabela P. de O.
Published: March 2013

Na bacia dos igarapés Timboteua e Buiuna, no Estado do Pará, avaliou-se a influência das mudanças de uso da terra e do manejo do solo sobre as taxas de escoamento superficial. Foram estabelecidas 18 parcelas experimentais (1 m²) sendo três em cada um dos seis agroecossistemas avaliados, a saber: i) Capoeira de 20 anos (CP); ii) Sistema agroflorestal / derruba-e-queima (SQ); iii) Sistema agroflorestal / corte-e-trituração (ST); iv) Cultivo de mandioca / corte-e-trituração - Roça (RT); v) Cultivo de mandioca / derruba-e-queima - Roça (RQ); vi) Pastagem / derruba-e-queima (PQ). Adicionalmente foram instalados, na mesma localidade, dois pluviômetros e três coletores de água de chuva (CH) para monitoramento da precipitação. Em 26 datas ao longo da estação chuvosa de 2010, foram coletadas 234 amostras, obtendo-se alta correlação entre volumes precipitado e escoado. O agroecossistema de Pastagem (PQ) degradada apresentou o maior valor de 54,53% do total de escoamento superficial medido nesta pesquisa, e o SAF, que estava em recuperação de 7 anos após uma queima, o menor valor de 1,11%. O escoamento superficial decresceu dos agroecossistemas de menor para os sistemas de maior percentagem de material orgânico.
Diagnose foliar em mudas de pinhão-manso (Jatropha Curcas L.) produzidas com biossólido
Authors: Reginaldo de Camargo Alirio C. D. Maldonado , Dias Polianna A. S. , Souza Monique F. , França Marcelo S.
Published: March 2013

O uso do biossólido na agricultura tem-se mostrado a melhor alternativa ambiental e econômica para o destino do lodo de esgoto. O objetivo deste trabalho foi avaliar o potencial nutricional do biossólido para produção de mudas de pinhão-manso em tubetes. O experimento foi realizado em casa de vegetação tendo, como substrato, esterco bovino, vermiculita e biossólido. O delineamento experimental foi o de blocos casualizados com três repetições em esquema fatorial 5 x 2, correspondendo às concentrações de biossólido no substrato (0, 10, 20, 30 e 40%) e ao tratamento ou não das sementes de pinhão-manso com fungicida. Aos 60 dias foi realizada análise foliar. Relativo às concentrações de biossólido verificou-se efeito significativo para os macronutrientes N, P, Ca, Mg e S e micronutrientes B, Cu, Mn e Zn. O tratamento de sementes teve efeito significativo para o Zn. As folhas apresentaram concentração de macronutrientes com a seguinte ordem: N > K > Mg > Ca > P > S. O acúmulo de micronutrientes apresentou a seguinte ordem: Fé > Mn >Zn > B > Cu. Há grande contribuição do biossólido nos teores de nitrogênio, enxofre e micronutrientes foliares, em plantas de pinhão-manso.
Análise crítica das analogias do livro didático público de Química do estado do Paraná
Authors: Bernardino Mychelle Amorim Defenti , Rodrigues Maria Aparecida , Bellini Luzia Marta
Published: March 2013

As analogias no âmbito da educação, em particular nas ciências da natureza, podem ser consideradas um recurso com grande potencial didático no processo ensino-aprendizagem, já que têm a função de auxiliar o aluno na compreensão de conceitos e fenômenos desconhecidos, por meio de comparações de atributos de similaridade com outros já conhecidos. Tendo em vista que os livros didáticos são, em muitos casos, o principal material utilizado, esta pesquisa teve como objetivo identificar e analisar as analogias do Livro Didático Público de Química do Estado do Paraná. Como resultados, foram encontradas vinte e cinco analogias, abrangendo diferentes tópicos de Química do livro. Os tópicos que apresentaram predominância de analogias foram os de ligações químicas e estrutura atômica. De acordo com o critério nível de enriquecimento, vinte e duas das analogias encontradas são simples, ou seja, compartilham um único atributo.
Effect of Low Temperature on Purple Nutsedge (Cyperus rotundus) Reproductive Biology
Authors: Dor Evgenia , Hershenhorn Joseph
Published: March 2013

Purple nutsedge is considered to be the worst weed in the tropical and subtropical regions of the world. Although the plant is a low grower it has very strong competitive abilities. The influence of initial tuber size and cold treatment on tuber sprouting, accumulation of plant biomass and new tubers formation was studied. Tubers sprouted continuously over 30 to 50 d with significantly lower sprouting ability of small tubers (0.1 to 0.2 g). Short cold treatment (4 C for 4 d) significantly stimulated sprouting process. The early sprouting of cold treated tubers led to increased number of shoots and inflorescences and therefore more intensive biomass accumulation, as well as more intensive formation of new tubers. The increase in total biomass accumulation raises the reproductive and spreading potential of the weed.
Tomato Root Uptake of Carfentrazone
Authors: Crespo Aline M. , MacRae Andrew W. , Alves Cristiane , Jacoby Tyler P. , Kelly Rick O.
Published: March 2013

Fresh market tomato is an important and valuable crop in Florida, accounting for 630 million dollars farm-gate value, which was 45% of the total value of the U.S. crop in 2010. In order to maintain or increase its productivity, labeled herbicide alternatives to methyl bromide are important to limiting seed production of weeds emerging between the raised plasticulture beds. A study was conducted inside a greenhouse where carfentrazone was applied as a drench at 0.03125×, 0.0625×, 0.125×, 0.25×, 0.5×, 1×, 2×, 4×, and 8× and as a subsurface irrigation at 0.0625×, 0.125×, 0.25×, 0.5×, 1×, 2×, 4×, 8×, and 16× rates. The 1× rate equaled the maximum labeled rate of carfentrazone (35.1 g ai ha−1) that would be applied to an area of 0.360 m2. Both the drench and subsurface trials showed an increase in plant injury and reduced growth as the rate of carfentrazone increased. The drench trial, however, was observed to have higher visible injury and greater growth reduction (based on plant measurement) than the subsurface trial, when comparing similar rates. For the 1× rate of carfentrazone in the drench trial vs. the subsurface trial, injury was 66 and 24.5%, respectively. For the 1× rate the tomato plants had estimated growth, based on the curves fit for the data, of 4.8% vs. 39.9% for the drench and subsurface trials, respectively. The subsurface trial better represents what happens in the field when carfentrazone root uptake injury is observed since it is normally observed to be around 10% or less. This still leaves a level of concern; once a 10% injury level in the subsurface trial was estimated to have reduced tomato growth, fruit weight, and total shoot dry weight by 33, 15, and 9.5%, respectively.
Impact of Fallow Programs and Fumigants on Nutsedge (Cyperusspp.) Management in Plasticulture Tomato
Authors: Alves Cristiane , MacRae Andrew W. , Hunnicut Clinton J. , Jacoby Tyler P. , MacDonald Gregory E. , Dittmar Peter J.
Published: March 2013

With the loss of methyl bromide (MeBr) and high prices of alternatives, tomato growers are applying lower fumigant rates or adopting a reduced system. Without the broad-spectrum control provided by the complete fumigant system, a fallow weed program might be needed to avoid an increase in pest pressure with consecutive years of application of the reduced-fumigant system. Nutsedges are among the pests of interest due to their fast reproduction by underground structures and ability to spread and quickly infest a field. Field trials were conducted between February and December of 2011 in Balm, FL, to evaluate the impacts of fallow treatments, fumigants, and halosulfuron on nutsedge control. The trial design was a split–split plot with main, sub-, and subsubplots being fallow, fumigant, and herbicide treatment, respectively. Fallow treatments were spaced evenly throughout the fallow season and consisted of sequential combinations of cultivation (C) and/or glyphosate (G) applied at 2.24 kg ae ha−1; including: C, CC, G, GG, CG, GC, GCG, and NO (nontreated control). Fumigant treatments included a reduced-fumigant system of 1,3-dichloropropene plus chloropicrin 40:60 (1,3-D + pic) at 281 kg ha−1, a complete fumigant system of dimethyl disulfide plus chloropicrin 79:21 (DMDS + pic) at 545 kg ha−1, and no fumigant (NoFum). Herbicide treatments were either two POST applications of halosulfuron at 39 g ai ha−1(Hal) or no halosulfuron (NoHal). In general, the fallow weed treatment GCG was the most effective in reducing nutsedge shoot emergence through the plastic mulch. When the reduced-fumigant system 1,3-D + pic was combined with GCG fallow treatment and halosulfuron (GCG:1,3-D + pic:Hal), no differences were found between this combination and the complete fumigant system DMDS + pic with halosulfuron and combined with CC, G, GG, CG, GC or GCG. This study shows the importance of adding a fallow weed program and halosulfuron to either a reduced or complete fumigation system to minimize the reproduction and growth of nutsedges.
Evaluation of effect of backfill particle size on installation damage reduction factors for geogrids
Authors: Lim S.Y. , McCartney J.S.
Published: March 2013

ABSTRACT: The reduction factors used to account for the impact of installation damage on the tensile strength of geogrids employed in mechanically stabilised earth (MSE) walls and reinforced embankments are usually obtained from field tests that simulate actual construction conditions. Although costly and time-consuming, site-specific field tests incorporate the damage mechanisms that may occur in geogrid reinforcements during installation. Several studies have developed empirical relationships for these reduction factors for use in design calculations, typically considering the effects of construction methods and the backfill soil gradation on the damage of geogrids having a given polymer type, manufacturing method, and weight per unit area. One of the issues with these relationships is how to quantify the backfill soil gradation in the empirical relationships. In this study, a series of field test sections were constructed using geogrids with two polymer types and a range of different weights per unit area to identify quantitative relationships that can be used to better estimate the impact of backfill gradation on the reduction factors for installation damage of geogrids. The results from the field test sections indicate that the reduction in tensile strength of geogrids after installation is non-linearly related to the maximum particle size in the backfill soil. Recommended upper-bound relationships for the reduction in tensile strength for different geogrid polymers are presented based on an evaluation of data sets, with a greater reduction factor observed for polyvinyl-chloride-coated woven polyethylene geogrids than for high-density uniaxially-drawn polyethylene geogrids.
Household age structure and consumption in Serbia
Authors: Radivojevic Biljana , Vasic Petar
Published: March 2013

The influence of demographic variables on household consumption level and
structure is understood but insufficiently studied in Serbia. This paper
analyzes the connection between age as a demographic variable, and the size
and structure of household consumption as economic phenomena. We discuss the
research results, trying to explain the intensity and direction of the shown
connection. The economic variables are usually set as determinants of
demographic processes, but we set age as an independent demographic variable
shaping household consumption without ignoring the household income level. It
seems that the age structure of a household, particularly the age of the
household head, has a significant influence on consumption structure.
Barriers to competitive fringe expansion as a seed of market power
Authors: Gerasymenko Anzhelika
Published: March 2013

Starting from the behavioral approach to economic competition, this paper
enlarges the traditional view of economics on the essence of potential
competition by including not only the potency of competition from new but
also the potency of competition from existing firms of the competitive fringe
and from distant substitutes because of their ability to be actualized upon
changes in market conjuncture. The author specifies three types of barriers
to potential competition: barriers to entry, barriers to switching demand,
and barriers to competitive fringe expansion. This paper is devoted to the
analysis of the latter, answering the question of their influence on the
market power of incumbent firms. The theoretical and empirical analysis in
the paper explains the important role of establishment and exploitation of
barriers to competitive fringe expansion in maintaining the market power of a
dominant firm and the maximization of its economic rent.
5-15 yaş arası astımlı çocuklar›n sosyodemografik özellikleri ve risk faktörleri
Authors: Önder Nurgül , Hatipoğlu Sami , İnanç Betül Battaloğlu , Sıkar Derya
Published: March 2013

Amaç: Bir astım allerji polikliniğine başvuran astımlı çocukların sosyodemografik özellikleri ve risk faktörlerinin belirlenmesi amaçlanmıştır.Yöntem: Tanımlayıcı nitelikteki bu araştırmada 1 Ocak 2005–31 Aralık 2005 tarihleri arasında, Bakırköy Dr. Sadi Konuk Eğitim ve Araştırma Hastanesi Astım Alerji Polikliniği’nde astım tanısıyla izlenen, 5-15 yaşları arasındaki 450 hastanın dosyaları retrospektif olarak taranıp, hastaların sosyodemografik özellikleri, hastalığın başlama yaşı, risk faktörleri araştırılmıştır.Bulgular: Olguların %60.9’u erkek, ortalama yaş 8.4±2.7 ve semptomların başlama yaşı ortalama 3.6±2.7 idi. Hastaların %95.6’s› düşük gelirli olduklarını belirten ailelere sahipken, %46.4’ü ısınmada kömür kullanıyor, %67.1’i nemli ortamda yaşıyordu. Son bir yıl içerisinde acile başvuranların oranı %66.7 iken, hastaneye yatırılma oran› %10.9 olarak bulundu.Sonuç: Çalışmamızda değerlendirilen astımlı çocukların sosyodemografik özellikleri ve risk faktörleri literatür ile uyumlu bulunmuştur.
Fetiflizm ve voyörizm birlikteliği: Bir olgu sunumu
Authors: Ertekin Hülya , Özayhan Hatice Yardım , Eren İbrahim , Ertekin Yusuf Haydar
Published: March 2013

Bir parafili türü olan fetişizm, kişinin cansız nesnelere, belirli vücut bölümlerini kullanarak cinsel haz elde etmesidir. Diğer bir parafili tipi olan voyörizm, çıplak olan ya da soyunan, giyinen ya da cinsel etkinlikte bulunan kişiyi gözetlemeyi içeren, fantaziler ve etkinlikler ile tekrarlayıcı uğraşıdır. Bu makalede fetişizm ve voyörizmi olan 26 yaşında erkek olgu sunumu yapılacaktır, bu olgunun psikiyatrik öyküsü ve aile dinamikleri ele alınmıştır.
Debromination of 2,4,6-tribromophenol coupled with biodegradation
Authors: Weidlich Tomáš , Prokeš Lubomír , Pospíšilová Dagmar
Published: March 2013

The application effect of aluminium and their alloys and mixtures with nickel was studied for the complete hydrodebromination of 2,4,6-tribromophenol (TBP) to phenol in aqueous NaOH solution at room temperature. It was found that the Raney Al-Ni alloy can rapidly transform TBP to phenol. Removal efficiency of 25 mM TBP solution in aqueous NaOH (15 g L−1) solution at the end of 1h reaction was 100% using 4 g L−1 Al-Ni. The hydrodebromination is accompanied by the dissolution of aluminium and formation of soluble Al(OH)4−1 anions under these reaction conditions. After completion of the hydrodebromination reaction removal of the dissolved metals was achieved by precipitation of appropriate hydroxides by adjustment of the pH value and filtration, the filtrate was treated with Pseudomonas or Rhodococcus bacterial strains to degrade dissolved phenol. The combined application of both (chemical-biological) treatments produced degradations of 100% of aromatic compounds.
The number of split points of a Morse form and the structure of its foliation
Authors: Gelbukh Irina
Published: March 2013

Sharp bounds are given that connect split points — conic singularities of a special type — of a Morse form with the global structure of its foliation.
Periodic solution to p-Laplacian neutral Liénard type equation with variable parameter
Authors: Du Bo
Published: March 2013

Using Mawhin’s continuation theorem we obtain some existence results of periodic solutions for a type of p-Laplacian neutral Liénard equation $$\left( {\phi _p \left( {\left( {x\left( t \right) - c\left( t \right)x\left( {t - \tau } \right)} \right)^\prime } \right)} \right)^\prime + f\left( {x\left( t \right)} \right)x'\left( t \right) + g\left( {x\left( {t - \gamma \left( t \right)} \right)} \right) = e\left( t \right).$$ It is worth noting that c(t) is no longer a constant which is different from the corresponding ones of past work.
Nonindigenous Plant Advantage in Native and Exotic Australian Grasses under Experimental Drought, Warming, and Atmospheric CO2 Enrichment
Authors: Godfree Robert , Robertson Bruce , Gapare Washington , Ivković Miloš , Marshall David , Lepschi Brendan , Zwart Alexander
Published: March 2013

A general prediction of ecological theory is that climate change will favor invasive nonindigenous plant species (NIPS) over native species. However, the relative fitness advantage enjoyed by NIPS is often affected by resource limitation and potentially by extreme climatic events such as drought. Genetic constraints may also limit the ability of NIPS to adapt to changing climatic conditions. In this study, we investigated evidence for potential NIPS advantage under climate change in two sympatric perennial stipoid grasses from southeast Australia, the NIPS Nassella neesiana and the native Austrostipa bigeniculata. We compared the growth and reproduction of both species under current and year 2050 drought, temperature and CO2 regimes in a multifactor outdoor climate simulation experiment, hypothesizing that NIPS advantage would be higher under more favorable growing conditions. We also compared the quantitative variation and heritability of growth traits in populations of both species collected along a 200 km climatic transect. In contrast to our hypothesis we found that the NIPS N. neesiana was less responsive than A. bigeniculata to winter warming but maintained higher reproductive output during spring drought. However, overall tussock expansion was far more rapid in N. neesiana, and so it maintained an overall fitness advantage over A. bigeniculata in all climate regimes. N. neesiana also exhibited similar or lower quantitative variation and growth trait heritability than A. bigeniculata within populations but greater variability among populations, probably reflecting a complex past introduction history. We found some evidence that additional spring warmth increases the impact of drought on reproduction but not that elevated atmospheric CO2 ameliorates drought severity. Overall, we conclude that NIPS advantage under climate change may be limited by a lack of responsiveness to key climatic drivers, reduced genetic variability in range-edge populations, and complex drought-CO2 interactions.
Ecology of Subglacial Lake Vostok (Antarctica), Based on Metagenomic/Metatranscriptomic Analyses of Accretion Ice
Authors: Rogers Scott , Shtarkman Yury , Koçer Zeynep , Edgar Robyn , Veerapaneni Ram , D'Elia Tom
Published: March 2013

Lake Vostok is the largest of the nearly 400 subglacial Antarctic lakes and has been continuously buried by glacial ice for 15 million years. Extreme cold, heat (from possible hydrothermal activity), pressure (from the overriding glacier) and dissolved oxygen (delivered by melting meteoric ice), in addition to limited nutrients and complete darkness, combine to produce one of the most extreme environments on Earth. Metagenomic/metatranscriptomic analyses of ice that accreted over a shallow embayment and over the southern main lake basin indicate the presence of thousands of species of organisms (94% Bacteria, 6% Eukarya, and two Archaea). The predominant bacterial sequences were closest to those from species of Firmicutes, Proteobacteria and Actinobacteria, while the predominant eukaryotic sequences were most similar to those from species of ascomycetous and basidiomycetous Fungi. Based on the sequence data, the lake appears to contain a mixture of autotrophs and heterotrophs capable of performing nitrogen fixation, nitrogen cycling, carbon fixation and nutrient recycling. Sequences closest to those of psychrophiles and thermophiles indicate a cold lake with possible hydrothermal activity. Sequences most similar to those from marine and aquatic species suggest the presence of marine and freshwater regions.
Cellulose Perversions
Authors: Canejo João , Godinho Maria
Published: March 2013

Cellulose micro/nano-fibers can be produced by electrospinning from liquid crystalline solutions. Scanning electron microscopy (SEM), as well as atomic force microscopy (AFM) and polarizing optical microscopy (POM) measurements showed that cellulose-based electrospun fibers can curl and twist, due to the presence of an off-core line defect disclination, which was present when the fibers were prepared. This permits the mimicking of the shapes found in many systems in the living world, e.g., the tendrils of climbing plants, three to four orders of magnitude larger. In this work, we address the mechanism that is behind the spirals’ and helices’ appearance by recording the trajectories of the fibers toward diverse electrospinning targets. The intrinsic curvature of the system occurs via asymmetric contraction of an internal disclination line, which generates different shrinkages of the material along the fiber. The completely different instabilities observed for isotropic and anisotropic electrospun solutions at the exit of the needle seem to corroborate the hypothesis that the intrinsic curvature of the material is acquired during liquid crystalline sample processing inside the needle. The existence of perversions, which joins left and right helices, is also investigated by using suspended, as well as flat, targets. Possible routes of application inspired from the living world are addressed.
Astaxanthin Suppresses MPP+-Induced Oxidative Damage in PC12 Cells through a Sp1/NR1 Signaling Pathway
Authors: Ye Qinyong , Zhang Xiaodong , Huang Bixia , Zhu Yuangui , Chen Xiaochun
Published: March 2013

Objective: To investigate astaxanthin (ATX) neuroprotection, and its mechanism, on a 1-methyl-4-phenyl-pyridine ion (MPP+)-induced cell model of Parkinson’s disease. Methods: Mature, differentiated PC12 cells treated with MPP+ were used as an in vitro cell model. The MTT assay was used to investigate cell viability after ATX treatment, and western blot analysis was used to observe Sp1 (activated transcription factor 1) and NR1 (NMDA receptor subunit 1) protein expression, real-time PCR was used to monitor Sp1 and NR1 mRNA, and cell immunofluorescence was used to determine the location of Sp1 and NR1 protein and the nuclear translocation of Sp1. Results: PC12 cell viability was significantly reduced by MPP+ treatment. The expression of Sp1 and NR1 mRNA and protein were increased compared with the control (p < 0.01). Following co-treatment with ATX and MPP+, cell viability was significantly increased, and Sp1 and NR1 mRNA and protein were decreased, compared with the MPP+ groups (p < 0.01). In addition, mithracycin A protected PC12 cells from oxidative stress caused by MPP+ by specifically inhibiting the expression of Sp1. Moreover, cell immunofluorescence revealed that ATX could suppress Sp1 nuclear transfer. Conclusion: ATX inhibited oxidative stress induced by MPP+ in PC12 cells, via the SP1/NR1 signaling pathway.
Gene Dosage Analysis in a Clinical Environment: Gene-Targeted Microarrays as the Platform-of-Choice
Authors: Marquis-Nicholson Renate , Prosser Debra , Love Jennifer , Love Donald
Published: March 2013

The role of gene deletion and duplication in the aetiology of disease has become increasingly evident over the last decade. In addition to the classical deletion/duplication disorders diagnosed using molecular techniques, such as Duchenne Muscular Dystrophy and Charcot-Marie-Tooth Neuropathy Type 1A, the significance of partial or whole gene deletions in the pathogenesis of a large number single-gene disorders is becoming more apparent. A variety of dosage analysis methods are available to the diagnostic laboratory but the widespread application of many of these techniques is limited by the expense of the kits/reagents and restrictive targeting to a particular gene or portion of a gene. These limitations are particularly important in the context of a small diagnostic laboratory with modest sample throughput. We have developed a gene-targeted, custom-designed comparative genomic hybridisation (CGH) array that allows twelve clinical samples to be interrogated simultaneously for exonic deletions/duplications within any gene (or panel of genes) on the array. We report here on the use of the array in the analysis of a series of clinical samples processed by our laboratory over a twelve-month period. The array has proven itself to be robust, flexible and highly suited to the diagnostic environment.
Energetic and Entropic Contributions to the Landau–de Gennes Potential for Gay–Berne Models of Liquid Crystals
Authors: Gupta Bhaskar , Ilg Patrick
Published: March 2013

The Landau–de Gennes theory provides a successful macroscopic description of nematics. Cornerstone of this theory is a phenomenological expression for the effective free energy as a function of the orientational order parameter. Here, we show how such a macroscopic Landau–de Gennes free energy can systematically be constructed for a microscopic model of liquid crystals formed by interacting mesogens. For the specific example of the Gay–Berne model, we obtain an enhanced free energy that reduces to the familiar Landau–de Gennes expression in the limit of weak ordering. By carefully separating energetic and entropic contributions to the free energy, our approach reconciles the two traditional views on the isotropic–nematic transition of Maier–Saupe and Onsager, attributing the driving mechanism to attractive interactions and entropic effects, respectively.
Évolutions démographiques et retraites : quinze ans de débats
Authors: Blanchet Didier
Published: March 2013

Alors que se précisent les modalités de modification par le gouvernement Ayrault de la réforme de 2010 des retraites, nous republions un article de synthèse de Didier Blanchet 1  , auteur du rapport Démographie et économie 2  du Conseil d’analyse économique. Les projections de population de 2006, confirmées par celles de 2010, ont légèrement infléchi le diagnostic formulé à l’époque 3  : sous l’effet d’une fécondité plus dynamique que les hypothèses retenues initialement, l’Insee ne prévoit plus une diminution de la population active de l’ampleur décrite mais sa quasi-stabilisation. Néanmoins, puisque la population des plus de 60 ans croît relativement rapidement sous l’effet de l’augmentation continue de l’espérance de vie, le ratio de dépendance ne peut qu’augmenter à un rythme soutenu.
Quelle régulation sociale et économique de la pauvreté ?
Authors: Périvier Hélène
Published: March 2013

Pour compléter notre dossier consacré à la pauvreté et l’exclusion sociale, nous vous proposons cet article récent d’Hélène Périvier 1 , économiste à l’OFCE, spécialiste de la protection sociale. Elle analyse les politiques de lutte contre la pauvreté et discute la question très polémique des effets supposés désincitatifs des minima sociaux en France (les trappes à pauvreté). Elle propose également une comparaison très intéressante avec les États-Unis en étudiant les réformes du système de protection sociale américain.
La Russie et le Moyen-Orient : entre islamisme et occidentalisme
Authors: Tsygankov Andreï P.
Published: March 2013

Au-delà des intérêts de puissance, le rejet de l’islamisme et de l’occidentalisme explique la position présente de la Russie au Moyen-Orient. Radicalisme menaçant directement la Fédération, l’islamisme incite Moscou à tendre la main aux régimes qui le combattent. Ethnocentrisme des démocraties visant à assurer leur domination, l’occidentalisme pousse la Russie à s’opposer à l’interventionnisme dans la région des puissances occidentales, tout en affirmant une voie civilisationnelle propre. politique étrangère
Deriving ice thickness, glacier volume and bedrock morphology of Austre Lovénbreen (Svalbard) using GPR
Authors: Saintenoy A. , Friedt J.‐M. , Booth A. D. , Tolle F. , Bernard E. , Laffly D. , Marlin C. , Griselin M.
Published: March 2013

Austre Lovénbreen is a 4.6 km2 glacier on the Archipelago of Svalbard (79° N) that has been surveyed over the last 47 years in order to monitor in particular the glacier evolution and associated hydrological phenomena in the context of nowadays global warming. A three‐week field survey during April 2010 allowed for the acquisition of a dense mesh of ground‐penetrating radar (GPR) data with an average of 14 683 points per km2 (67 542 points total) on the glacier surface. The profiles were acquired using Mala equipment with 100 MHz antennas, towed slowly enough to record on average every 0.3 m, a trace long enough to sound down to 189 m of ice. One profile was repeated with a 50 MHz antenna set to improve electromagnetic wave propagation depth in scattering media observed in the cirques closest to the slopes. The GPR was coupled to a GPS system to position traces. Each profile was manually edited using standard GPR data processing including migration, to pick the reflection arrival time from the ice‐bedrock interface. Snow cover was evaluated through 42 snow drilling measurements regularly spaced to cover the entire glacier. These data were acquired at the time of the GPR survey and subsequently spatially interpolated using ordinary kriging. Using a snow velocity of 0.22 m/ns, the snow thickness was converted to electromagnetic wave traveltimes and subtracted from the picked traveltimes to the ice‐bedrock interface. The resulting traveltimes were converted to ice thickness using a velocity of 0.17 m/ns. The velocity uncertainty is discussed from a common midpoint profile analysis. A total of 67 542 geo‐referenced data points with GPR‐derived ice thicknesses, in addition to a glacier boundary line derived from satellite images taken during summer, were interpolated over the entire glacier surface using kriging with a 10 m grid size. Some uncertainty analyses were carried out and we calculated an averaged ice thickness of 76 m and a maximum depth of 164 m with a relative error of 11.9%. The volume of the glacier is derived as 0.3487 ± 0.041 km3. Finally a 10 m grid map of the bedrock topography was derived by subtracting the ice thicknesses from a dual‐frequency GPS‐derived digital elevation model of the surface. These two data sets are the first step for modelling thermal evolution of a glacier and its bedrock, as well as the main hydrological network.
Adaptation urbaine post-catastrophe : la recomposition territoriale de La Nouvelle Orléans
Authors: Zaninetti Jean-Marc
Published: March 2013

La Nouvelle Orléans n’a pas encore fini de se relever de la dévastation provoquée par Katrina en 2005. Cependant, les recompositions territoriales du peuplement manifestent déjà une adaptation « du second ordre » à l’exposition récurrente de la région au risque cyclonique. Katrina a inversé la tendance antérieure à l’étalement urbain dans les marais. Le concept d’adaptation du second ordre désigne les ajustements résultant des décisions individuelles des acteurs privés plutôt que d’un aménagement décidé par les acteurs publics. Toutefois, La Nouvelle Orléans peine encore à admettre qu’elle gagnerait à regrouper sa population dans un périmètre plus restreint.
Mast Cell FcεRI-Induced Early Growth Response 2 Regulates CC Chemokine Ligand 1–Dependent CD4+ T Cell Migration
Authors: Wu Zhengli , MacNeil Adam J. , Junkins Robert , Li Bo , Berman Jason N. , Lin Tong-Jun
Published: March 2013

Mast cells are well positioned in host tissue for detecting environmental signals, including allergens, leading to activation of the high-affinity IgE receptor FcεRI, and initiating a signaling cascade that perpetuates the production of biologically potent mediators, including chemokines. We have identified a novel target of mast cell FcεRI activity in the transcription factor early growth response 2 (Egr2) and sought to characterize its function therein. Egr2 was transiently activated following FcεRI-mediated signaling, targeted the promoter of the chemokine CCL1, and was critical for allergen-induced mast cell CCL1 production. Egr2-deficient mast cells were incapable of directing CD4+ T cell migration via the CCL1–CCR8 axis. In a model of allergic asthma, reconstitution of mast cell–deficient mice with Egr2-deficient mast cells demonstrated that mast cell Egr2 was essential for migration of CD4+ T cells to the inflamed lung. These findings position Egr2 as a critical regulator of mast cell–directed CD4+ T cell migration.
Skriftuurlike perspektiewe op die effek van doop op vergifnis
Authors: De Klerk Barend J.
Published: March 2013

Scriptural perspectives on the effect of baptism on forgiveness. This article focused from a Scriptural perspective on the question of whether baptism can and should have an effect on forgiveness and reconciliation in the South African society. This aspect was examined because in one of the most widely used confessionals of the worldwide church, the Nicene Creed, the following words are found: �We believe in � one baptism for the forgiveness of sin�. Another reason for investigating the effect that baptism should have on forgiveness and reconciliation is the connection between God�s forgiveness and the calling on the baptised to forgive. The article highlighted the following five key points: God acts in baptism; the Triune God works in baptism; the covenant relationship is expressed in baptism; baptism is a baptism in Christ�s death and resurrection; God�s forgiveness and reconciliation in baptism call the baptised to forgive.
Provider Use of and Attitudes Towards an Active Clinical Alert
Authors: Feblowitz J. , Henkin S. , Pang J. , Ramelson H. , Schneider L. , Maloney F. L. , Wilcox A. R. , Bates D.W. , Wright A.
Published: March 2013

Background: In a previous study, we reported on a successful clinical decision support (CDS) intervention designed to improve electronic problem list accuracy, but did not study variability of provider response to the intervention or provider attitudes towards it. The alert system accurately predicted missing problem list items based on health data captured in a patient’s electronic medical record.

Objective: To assess provider attitudes towards a rule-based CDS alert system as well as heterogeneity of acceptance rates across providers.

Methods: We conducted a by-provider analysis of alert logs from the previous study. In addition, we assessed provider opinions of the intervention via an email survey of providers who received the alerts (n = 140).

Results: Although the alert acceptance rate was 38.1%, individual provider acceptance rates varied widely, with an interquartile range (IQR) of 14.8%-54.4%, and many outliers accepting none or nearly all of the alerts they received. No demographic variables, including degree, gender, age, assigned clinic, medical school or graduation year predicted acceptance rates. Providers’ self-reported acceptance rate and perceived alert frequency were only moderately correlated with actual acceptance rates and alert frequency.

Conclusions: Acceptance of this CDS intervention among providers was highly variable but this heterogeneity is not explained by measured demographic factors, suggesting that alert acceptance is a complex and individual phenomenon. Furthermore, providers’ self-reports of their use of the CDS alerting system correlated only modestly with logged usage.

Citation: Feblowitz J, Henkin S, Pang J, Ramelson H, Schneider L, Maloney FL, Wilcox AR, Bates DW, Wright A. Provider use of and attitudes towards an active clinical alert. A case study in decision support. Appl Clin Inf 2013; 4: 144–152

http://dx.doi.org/10.4338/ACI-2012-12-RA-0055
The Influence of Collaborative Reflection and ThinkAloud Protocols on Pre-Service Teachers’ Reflection: A Mixed Methods Approach
Authors: Epler Cory M. , Drape Tiffany A. , Broyles Thomas W. , Rudd Rick D.
Published: March 2013

The purpose of this mixed methods study was to determine if there are differences in pre-service teachers’ depth of reflection when using a written self-reflection form, a written self-reflection form and a thinkaloud protocol, and collaborative reflection. Twenty-six pre-service teachers were randomly assigned to fourteen teaching teams. The teams taught a lesson that was videotaped and completed a written selfreflection form while viewing their lesson. The participants were randomly assigned to a control group or experimental group. The control group reflected individually using a written self-reflection form. Experimental Group #1 reflected collaboratively using a written self-reflection form, and Experimental Group #2 reflected individually using a think-aloud process while completing the written self-reflection form. The reflection forms were analyzed for depth of reflection, and a one-way ANOVA revealed significant differences in depth of reflection between the three groups. Participants also engaged in focus group interviews to describe their experiences. Two significant themes emerged: reflection on the teaching experience and reflection on the process used. We recommend that reflection should be used to help pre-service teachers learn from experience. In addition, the use of collaborative reflection and reflection using think-aloud protocols should be considered to promote deeper reflection and understanding.
The Nerve of That Disease: The Vagus Nerve and Cardiac Rehabilitation
Authors: Gevirtz Richard
Published: March 2013

The emphasis on the sympathetic nervous system (SNS) in cardiology has recently shifted to a view recognizing the extraordinarily protective role that the (parasympathetic) vagus nerve plays in prevention and rehabilitation of heart muscle and pacemaker function. This article summarizes some of the epidemiological evidence supporting this premise and describes biofeedback-based interventions that may play a role in the future of cardiac disease prevention and rehabilitation.
Psychophysiologic Remodeling of the Failing Human Heart
Authors: Moravec Christine S. , McKee Michael G.
Published: March 2013

Autonomic imbalance is a therapeutic target in heart failure patients. Overactivation of the sympathetic branch of the autonomic nervous system has for years been treated with beta-adrenergic blocking drugs, although it cannot be long before invasive therapies such as renal sympathetic denervation, currently being tested for resistant hypertension, make their way to the heart failure arena. Insufficient parasympathetic input to the heart is already being augmented with implanted vagal nerve stimulators. It is our contention that biofeedback training could provide much of the same benefit as these more invasive therapies in improving autonomic imbalance, with the added advantage of increasing patient self-efficacy. This article describes a pilot study of biofeedback training in patients with end-stage heart failure awaiting heart transplantation. It was our goal to show not only that patients would appreciate this training and benefit from it but also that patient-controlled autonomic modulation could actually reverse the cellular and molecular markers of heart failure, or remodel the failing heart, similar to what we had previously shown for other types of heart failure therapy such as the left ventricular assist device. To our knowledge, this is the first study to demonstrate changes in the biology of the failing heart in response to a psychophysiologic intervention.
BCIA Launches a Heart Rate Variability Biofeedback Certificate of Completion
Authors: Shaffer Fred , Crawford Judy , Moss Donald
Published: March 2013

The Biofeedback Certification International Alliance (BCIA) has developed a certificate of completion program to establish education and training standards for the exciting modality of heart rate variability (HRV) biofeedback. HRV represents the beat-to-beat changes in the intervals between consecutive heartbeats. A growing list of HRV biofeedback applications has earned ratings from possibly efficacious to probably efficacious. BCIA's expert-designed Blueprint of Knowledge and exam promise to increase the academic rigor of didactic HRV biofeedback courses and enhance the knowledge of providers who incorporate this modality into their practice.
Lead (Pb2+) neurotoxicity: Ion-mimicry with calcium (Ca2+) impairs synaptic transmission. A review with animated illustrations of the pre- and post-synaptic effects of lead
Authors: Florea Ana-Maria , Taban Jasmin , Varghese Elizabeth , Alost Blane T. , Moreno Stacy , Büsselberg Dietrich
Published: March 2013

Lead (Pb2+) is ubiquitously distributed in the environment and shows significant health effects in humans, especially in the nervous system. In this review we illustrate how (Pb2+) neurotoxicity is associated with its ability to partially mimic the function of Ca2+ and modifies synaptic transmission pre- and post-synaptically. As Pb2+ binds to calcium-binding sites it alters their functionality, ranging from reduced currents through voltage and receptor gated channels, to modulation of ion-transporters and alterations of calcium-dependent signaling pathways. Overall Pb2+ exposure not only reduces pre-synaptically the transmitter release, but also post-synaptically the likelihood to generate a new action potential. This review will highlight the major-interactions with the different targets in schemes and short animated sequences to allow a general understanding of lead neurotoxicity to a wider audience; therefore, not all possible mechanisms will be mentioned or discussed.
Diabetes Insipidus: A Challenging Diagnosis with New Drug Therapies
Authors: Saifan Chadi , Nasr Rabih , Mehta Suchita , Sharma Acharya Pranab , Perrera Isera , Faddoul Giovanni , Nalluri Nikhil , Kesavan Mayurakhan , Azzi Yorg , El-Sayegh Suzanne
Published: March 2013

Diabetes Insipidus (DI) is either due to deficient secretion of arginine vasopressin (central) or to tubular unresponsiveness (nephrogenic). Drug induced DI is a well-known entity with an extensive list of medications. Polyuria is generally defined as urine output exceeding 3 liters per day in adults. It is crucial to identify the cause of diabetes insipidus and to implement therapy as early as possible to prevent the electrolyte disturbances and the associated mortality and morbidity. It is very rare to have an idiosyncratic effect after a short use of a medication, and physicians should be aware of such a complication to avoid volume depletion. The diagnosis of diabetes insipidus is very challenging because it relies on laboratory values, urine output, and the physical examination of the patient. A high clinical suspicion of diabetes insipidus should be enough to initiate treatment. The complications related to DI are mostly related to the electrolyte imbalance that can affect the normal physiology of different organ systems.
Differential Effects on Survival, Humoral Immune Responses and Brain Lesions in Inbred BALB/C, CBA/CA, and C57BL/6 Mice Experimentally Infected withNeospora caninumTachyzoites
Authors: Mols-Vorstermans Tanja , Hemphill Andrew , Monney Thierry , Schaap Dick , Boerhout Eveline
Published: March 2013

C57BL/6, BALB/c, and CBA/Ca mouse strains with different MHC-I haplotypes were compared with respect to susceptibility toNeospora caninuminfection. Groups of 5 mice received , , or tachyzoites of the NC-Liverpool isolate by intraperitoneal injection and were observed for disease symptoms. Humoral responses, splenocyte interferon-γ(IFN-γ) production, cerebral parasite loads, and histopathology were evaluated at human end points or the latest at 34 days postinfection (PI). The mortality rates in C57BL/6 mice were the highest, and relatively high levels of IgG1 antibodies were detected in those mice surviving till 34 days PI. In lymphocyte proliferation assays, spleen cells from C57BL6 mice stimulated withN. caninumantigen extract exhibited large variations in IFN-γproduction. In BALB/c mice mortality was 0% at the lowest and 100% at the highest infection dose. Serologically they responded with high levels of both IgG2a and IgG1 subclasses, and lymphocyte proliferation assays of surviving mice yielded lower IFN-γlevels. CBA/Ca mice were the most resistant, with no animal succumbing to infection at a dose of and tachyzoites, but 100% mortality at tachyzoites. High IgG2a levels as well as increased IFN-γin lymphocyte proliferation assays were measured in CBA/Ca mice infected with tachyzoites.
Food Safety and Food Access: A Pilot Study
Authors: Silbergeld Ellen K. , Frisancho Jose Augusto , Gittelsohn Joel , Anderson Steeves Elizabeth T. , Blum Matthew F. , Resnick Carol A.
Published: March 2013

Objectives: This study was designed to evaluate the feasibility of testing the hypothesis that differences in neighborhood level food access may be associated with consumer exposure to food borne microbial contamination.

Methods: This study was carried out in Baltimore MD in 2011 among selected neighborhoods defined as high or low food access. In each category, packages of chicken thighs and ground beef were purchased from small stores and supermarkets. We evaluated presence of E. coli and Staphylococcus aureus and also tested isolates for antimicrobial resistance.

Results: Microbial contamination of both chicken and beef products was highly prevalent (S. aureus-13/32 for chicken and 14/32 for beef; E. coli 21/32 for chicken and 12/32 for beef). Small stores were more likely to sell food carrying these microbes as well as MDR strains of both E. coli and S. aureus, and chicken was more likely to carry E. coli as compared to ground beef.

Conclusions: This is the first study of this hypothesis. While it is limited in size and in focus on one US city, the results indicate that further research is appropriate to examine neighborhood level risk factors for differential exposures to food borne microbes.

Abbreviations: S. aureus (Staphylococcus aureus); E. coli (Escherichia coli), MRSA (methicilllin resistant Staphylococcus aureus), MDR (multi-drug resistant), LFA (low food access), HFA (high food access). FDA (US Food and Drug Administration), USDA (US Department of Agriculture), CLSI (Clinical and Laboratory Standards Institute).
Math for Real:A Bear of a Problem
Authors: Nolan Edward C.
Published: March 2013

Denver's large blue bear, which resides outside the Colorado Convention Center, provides the real-life tie-in to this estimation activity.