Departures from convective equilibrium with a rapidly-varying surface forcing

Convective equilibrium is a long-standing and useful concept for understanding many aspects of the behaviour of deep moist convection. For example, it is often invoked in developing parameterizations for large-scale models. However, the equilibrium assumption may begin to break down as models are increasingly used with shorter timesteps and finer resolutions. Here we perform idealized cloud-system resolving model simulations of deep convection with imposed time variations in the surface forcing. A range of rapid forcing timescales from 1 − 36hr are used, in order to induce systematic departures from equilibrium. For the longer forcing timescales, the equilibrium assumption remains valid, in at least the limited sense that cycle-integrated measures of convective activity are very similar from cycle to cycle. For shorter forcing timescales, cycle-integrated convection becomes more variable, with enhanced activity on one cycle being correlated with reduced activity on the next, suggesting a role for convective memory. Further investigation shows that the memory does not appear to be carried by the domain-mean thermodynamic fields but rather by structures on horizontal scales of 5 − 20km. Such structures are produced by the convective clouds and can persist beyond the lifetime of the cloud, even through to the next forcing cycle.

Inside the black box: unravelling the development viability appraisal process

Over the last decade issues related to the financial viability of development have become increasingly important to the English planning system. As part of a wider shift towards the compartmentalisation of planning tasks, expert consultants are required to quantify, in an attempt to rationalise, planning decisions in terms of economic ‘viability’. Often with a particular focus on planning obligations, the results of development viability modelling have emerged as a key part of the evidence base used in site-specific negotiations and in planning policy formation. Focussing on the role of clients and other stakeholders, this paper investigates how development viability is tested in practice. It draws together literature on the role of calculative practices in policy formation, client feedback and influence in real estate appraisals and stakeholder engagement and consultation in the planning literature to critically evaluate the role of clients and other interest groups in influencing the production and use of development viability appraisal models. The paper draws upon semi-structured interviews with the main producers of development viability appraisals to conclude that, whilst appraisals have the potential to be biased by client and stakeholder interests, there are important controlling influences on potential opportunistic behaviour. One such control is local authorities’ weak understanding of development viability appraisal techniques which limits their capacity to question the outputs of appraisal models. However, this also is of concern given that viability is now a central feature of the town planning system.

The neurogenic potential of astrocytes is regulated by inflammatory signals

Although the adult brain contains neural stem cells (NSCs) that generate new neurons throughout life, these astrocyte-like populations are restricted to two discrete niches. Despite their terminally differentiated phenotype, adult parenchymal astrocytes can re-acquire NSC-like characteristics following injury, and as such, these 'reactive' astrocytes offer an alternative source of cells for central nervous system (CNS) repair following injury or disease. At present, the mechanisms that regulate the potential of different types of astrocytes are poorly understood. We used in vitro and ex vivo astrocytes to identify candidate pathways important for regulation of astrocyte potential. Using in vitro neural progenitor cell (NPC)-derived astrocytes, we found that exposure of more lineage-restricted astrocytes to either tumor necrosis factor alpha (TNF-α) (via nuclear factor-κB (NFκB)) or the bone morphogenetic protein (BMP) inhibitor, noggin, led to re-acquisition of NPC properties accompanied by transcriptomic and epigenetic changes consistent with a more neurogenic, NPC-like state. Comparative analyses of microarray data from in vitro-derived and ex vivo postnatal parenchymal astrocytes identified several common pathways and upstream regulators associated with inflammation (including transforming growth factor (TGF)-β1 and peroxisome proliferator-activated receptor gamma (PPARγ)) and cell cycle control (including TP53) as candidate regulators of astrocyte phenotype and potential. We propose that inflammatory signalling may control the normal, progressive restriction in potential of differentiating astrocytes as well as under reactive conditions and represent future targets for therapies to harness the latent neurogenic capacity of parenchymal astrocytes.

Tissue distribution of quiescin Q6/sulfhydryl oxidase (QSOX) in developing mouse

Quiescin Q6/sulfhydryl oxidases (QSOX) are revisited thiol oxidases considered to be involved in the oxidative protein folding, cell cycle control and extracellular matrix remodeling. They contain thioredoxin domains and introduce disulfide bonds into proteins and peptides, with the concomitant hydrogen peroxide formation, likely altering the redox environment. Since it is known that several developmental processes are regulated by the redox state, here we assessed if QSOX could have a role during mouse fetal development. For this purpose, an anti-recombinant mouse QSOX antibody was produced and characterized. In E-13.5, E-16.5 fetal tissues, QSOX immunostaining was confined to mesoderm- and ectoderm-derived tissues, while in P1 neonatal tissues it was slightly extended to some endoderm-derived tissues. QSOX expression, particularly by epithelial tissues, seemed to be developmentally-regulated, increasing with tissue maturation. QSOX was observed in loose connective tissues in all stages analyzed, intra and possibly extracellularly, in agreement with its putative role in oxidative folding and extracellular matrix remodeling. In conclusion, QSOX is expressed in several tissues during mouse development, but preferentially in those derived from mesoderm and ectoderm, suggesting it could be of relevance during developmental processes.

Stabilizing Nonstationary Electrochemical Time Series

Electrochemical systems are ideal working-horses for studying oscillatory dynamics. Experimentally obtained time series, however, are usually associated with a spontaneous drift in some uncontrollable parameter that triggers transitions among different oscillatory patterns, despite the fact that all controllable parameters are kept constant. Herein we present an empirical method to stabilize experimental potential time series. The method consists of applying a negative galvanodynamic sweep to compensate the spontaneous drift and was tested for the oscillatory electro-oxidation of methanol on platinum. For a wide range of applied currents, the base system presents spontaneous transitions from quasi-harmonic to mixed mode oscillations. Temporal patterns were stabilized by galvanodynamic sweeps at different rates. The procedure resulted in a considerable increase in the number of oscillatory cycles from 5 to 20 times, depending on the specific temporal pattern. The spontaneous drift has been associated with uncompensated oscillations, in which the coverage of some adsorbed species are not reestablished after one cycle; i.e., there is a net accumulation and/or depletion of adsorbed species during oscillations. We interpreted the rate of the galvanodynamic sweep in terms of the time scales of the poisoning processes that underlies the uncompensated oscillations and thus the spontaneous slow drift.

Nanofretting behaviors of NiTi shape memory alloy

Nanofretting refers to cyclic movements of contact interfaces with the relative displacement amplitude at the nanometer scale, where the contact area and normal load are usually much smaller than those in fretting. Nanofretting widely exists in microelctromechanical systems (MEMS) and may become a key tribological concern besides microwear and adhesion. With a triboindenter, the nanofretting behaviors of a nickel titanium (NiTi) shape memory alloy are studied under various normal loads (1–10 mN) and tangential displacement amplitudes (2–500 nm) by using a spherical diamond tip. Similar to fretting, the nanofretting of NiTi/diamond pair can also be divided into different regimes upon various shapes of tangential force–displacement curves. The dependence of nanofretting regime on the normal load and the displacement amplitude can be summarized in a running condition nanofretting map. However, due to the surface and size effects, nanofretting operates at some different conditions, such as improved mechanical properties of materials at the nanometer scale, small apparent contact area and single-asperity contact behavior. Consequently, different from fretting, nanofretting was found to exhibit several unique behaviors: (i) the maximum tangential force in one cycle is almost unchanged during a nanofretting test, which is different from a fretting test where the maximum tangential force increases rapidly in the first dozens of cycles; (ii) the tangential stiffness in nanofretting is three orders magnitude smaller than that in fretting; (iii) the friction coefficient in nanofretting is much lower than that in fretting in slip regime; (iv) no obvious damage was observed after 50 cycles of nanofretting under a normal load of 10 mN.

The association between urban or rural locality and hip fracture in community-based adults : a systematic review

Urban or rural locality has been suggested to influence musculoskeletal health, with lower bone mineral density (BMD) and greater prevalence of fracture identified in urban residents. A computer-aided search of Medline, EMBASE, CINAHL and PsychINFO, January 1966 to November 2007 was conducted to identify studies investigating the relationship between urban or rural locality and the occurrence of hip fracture. The methodological quality of studies was assessed, and a best-evidence synthesis was used to summarise the results. Fourteen cohort studies and one case-control study were identified for inclusion in this review, indicating a lack of literature in the field. Best-evidence analysis identified moderate evidence for residents of rural regions to have lower risk of hip fracture compared to urban residents. Examining principal mechanisms for the observed relationship between urban/rural locality and hip fracture, such as factors at the person or area level, may help to identify modifiable risk factors and inform appropriate prevention strategies.

Consciousness-raising tasks versus deductive approach : two form-focused instruction types in teaching grammar to Iranian high school EFL learners

Consciousness-raising (CR) task is a new way of teaching grammar developed in communicative contexts although little has been written on the effectiveness of CR tasks in EFL setting. The present study is an attempt to investigate the impact of CR tasks in Iranian EFL setting by comparing them with deductive, grammar lessons common in the Iranian schools. The subjects of this study were 80 EFL pre-university male students who were randomly assigned to an experimental group and a control one. The control group received three ordinary teacher-fronted, deductive lessons, a common way of teaching methodology in Iran, on three grammatical structures (adverb placement, indirect object placement and the use of relative clause). The experimental group, however, was treated with three ‘consciousness-raising’ (CR) tasks dealing with the same target structures. The results showed that in the short-run, CR tasks were as effective as deductive approach in promoting the learners’ grammatical knowledge while in the long-run, the CR group maintained their gains more effectively than the deductive group. The conclusion is that CR tasks can function more effectively than deductive approach if the following conditions are met: (a) performing the consciousness-raising tasks in learners’ L1; (b) providing the learners with feedback whenever they encounter a problem in solving the tasks; (c) grouping the learners in such a way that at least one learner in each group would be more proficient than the other members to help the less proficient ones understand and discover the rules more effectively.

The development of the institutional investor : the case of Australian life insurers 1945-85

This paper considers the post-war development of asset management practices among Australian life insurers, which have historically been among the largest institutional investors in Australia. A complex process of adaptation and organisational restructuring allowed life insurers to transform from basic investors of policy-holders’ funds to large multifaceted institutional investors in just three decades. Three stages in the development of investment practices are identified. These phases trace the process of expanding existing knowledge bases; diversification; and the acquisition of new skills; consolidation and the integration of these skills into institutional structures; thus completing one cycle of organisational learning and setting the stage for the next.

MicroRNAs: biogenesis, roles for carcinogenesis and as potential biomarkers for cancer diagnosis and prognosis

MicroRNAs (miRNAs) are short non-coding RNAs of 20-24 nucleotides that play important roles in carcinogenesis. Accordingly, miRNAs control numerous cancer-relevant biological events such as cell proliferation, cell cycle control, metabolism and apoptosis. In this review, we summarize the current knowledge and concepts concerning the biogenesis of miRNAs, miRNA roles in cancer and their potential as biomarkers for cancer diagnosis and prognosis including the regulation of key cancer-related pathways, such as cell cycle control and miRNA dysregulation. Moreover, microRNA molecules are already receiving the attention of world researchers as therapeutic targets and agents. Therefore, in-depth knowledge of microRNAs has the potential not only to identify their roles in cancer, but also to exploit them as potential biomarkers for cancer diagnosis and identify therapeutic targets for new drug discovery.

Escritórios abertos: interação ou controle?

Esta pesquisa discute o tema dos escritórios abertos com base em duas perspectivas: a interação e o controle. Busca responder ao seguinte questionamento: Até que ponto o escritório aberto constitui uma forma de aumentar a interação entre os indivíduos nas organizações ou, ao contrário, é mais um mecanismo de controle? O levantamento do acervo bibliográfico permitiu a identificação de quatro abordagens relacionadas ao tema. Duas foram tomadas como referência para suportar a coleta e a interpretação dos dados, assim como as conclusões do estudo: a abordagem das relações sociais e a abordagem crítica. Os resultados da pesquisa de campo revelaram que o escritório aberto constitui uma forma de aumentar a interação entre os indivíduos nas organizações mas é, também, um mecanismo de controle.

Egg production curve fitting using nonlinear models for selected and nonselected lines of White Leghorn hens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Controle de plantas daninhas na cultura de soja resistente ao glyphosate

O objetivo da pesquisa foi avaliar o controle de plantas daninhas em área cultivada com soja resistente ao herbicida glyphosate, sem a utilização de práticas complementares de manejo de plantas daninhas. Foram desenvolvidos experimentos, em condições de campo, nos anos agrícolas 2005/2006 e 2006/2007 em Jaboticabal (SP). Foram avaliadas duas cultivares de soja resistentes ao glyphosate (CD 214 RR e M-SOY 8008 RR), oito tratamentos de herbicidas (glyphosate, em aplicação única, nas doses de 0,48; 0,72; 0,96 e 1,20 kg ha-1 de equivalente ácido, associadas ou não a aplicação sequencial na dose de 0,48 kg ha-1), além de duas testemunhas, uma capinada e outra mantida infestada. As cultivares de soja influenciaram na infestação das espécies de plantas daninhas na área. Sem a aplicação de glyphosate, houve o predomínio de X. strumarium na área, desfavorecendo a ocorrência de outras espécies. Quando utilizado glyphosate, independentemente da dose, a infestação contabilizada aos 35 e 40 dias após a primeira aplicação, no primeiro e segundo ano, respectivamente, foi baixa. O controle de plantas daninhas na cultura da soja transgênica é diretamente influenciado pela dose de glyphosate, havendo controle satisfatório com a aplicação única de 0,96 kg ha-1 ou a sequencial de 0,48 + 0,48 kg ha-1 de glyphosate. em situação de menor infestação (2006/2007), a aplicação única de 0,48 kg ha-1 de glyphosate é suficiente para o controle das plantas daninhas. As cultivares de soja transgênica CD 214 RR e M-SOY 8008 RR influenciam diferencialmente a dinâmica das espécies de plantas daninhas, sendo o controle químico mais efetivo na situação de cultivo de M-SOY 8008 RR, em que houve menor diversidade e desenvolvimento das plantas daninhas.

Seletividade de herbicidas: III - aplicação de herbicidas em pós emergência inicial e tardia da cana-de-açúcar na época da estiagem

Este trabalho objetivou avaliar a seletividade dos herbicidas diuron+hexazinone, azafenidin+hexazinone, metribuzin e isoxaflutole aplicados em pós-emergência inicial e tardia das plantas de cana-de-açúcar, variedade RB835089, na época da estiagem, em soqueira de quarto corte, após colheita com queima prévia do canavial, em Araras, SP. O delineamento experimental foi o de blocos casualizados com testemunhas pareadas, com cinco tratamentos e quatro repetições, existindo uma testemunha capinada para cada tratamento químico dentro de cada bloco. Os tratamentos foram: diuron+hexazinone (1.170+330 g ha-1), azafenidin+ hexazinone (192,5+247,5 g ha-1), metribuzin (1.920 g ha-1), isoxaflutole (127,5 g ha¹) e testemunha capinada. Concluiu-se que os herbicidas foram mais fitotóxicos quando aplicados na pós-emergência tardia. em pós-emergência inicial, as plantas recuperaram-se totalmente dos efeitos fitotóxicos dos herbicidas. Na pós-emergência tardia, azafenidin+hexazinone, isoxaflutole e diuron+hexazinone prejudicaram o índice de fluorescência e a produtividade agrícola.

Seletividade de herbicidas: II - aplicação de herbicidas em pós-emergência inicial e tarida da cana-de-açúcar na época das chuvas

Objetivou-se com este trabalho testar a seletividade dos herbicidas diuron+hexazinone, azafenidin+hexazinone, metribuzin e isoxaflutole, aplicados em pósemergência inicial e tardia das plantas de cana-de-açúcar, cultivar RB835089, na época das chuvas, em soqueira de terceiro corte, após colheita com queima prévia do canavial, em Araras-SP. O delineamento experimental foi o de blocos casualizados com testemunhas pareadas, com cinco tratamentos e quatro repetições, existindo uma testemunha capinada para cada tratamento químico dentro de cada bloco. Os tratamentos foram: diuron+hexazinone (1.170+330 g ha-1), azafenidin+hexazinone (192,5+247,5 g ha-1), metribuzin (1.920 g ha-1), isoxaflutole (127,5 g ha-1) e testemunha. Concluiu-se que os herbicidas foram mais fitotóxicos quando aplicados na pós-emergência tardia. em pós-emergência inicial, o isoxaflutole foi o único produto que afetou a produtividade agrícola. Na pós-emergência tardia, todos os herbicidas prejudicaram a produtividade agrícola, sendo o diuron+hexazinone o único produto que não afetou as características tecnológicas e o rendimento de açúcar.