767 research outputs found
Comparative biology of different plant pathogens to estimate effects of climate change on crop diseases in Europe
This review describes environmental factors that influence severity of crop disease epidemics, especially in the UK and north-west Europe, in order to assess the effects of climate change on crop growth and yield and severity of disease epidemics. While work on some diseases, such as phoma stem canker of oilseed rape and fusarium ear blight of wheat, that combine crop growth, disease development and climate change models is described in detail, climate-change projections and predictions of the resulting biotic responses to them are complex to predict and detailed models linking climate, crop growth and disease development are not available for many crop-pathogen systems. This review uses a novel approach of comparing pathogen biology according to 'ecotype' (a categorization based on aspects such as epidemic type, dissemination method and infection biology), guided by detailed disease progress models where available to identify potential future research priorities for disease control. Consequences of projected climate change are assessed for factors driving elements of disease cycles of fungal pathogens (nine important pathogens are assessed in detail), viruses, bacteria and phytoplasmas. Other diseases classified according to 'ecotypes' were reviewed and likely changes in their severity used to guide comparable diseases about which less information is available. Both direct and indirect effects of climate change are discussed, with an emphasis on examples from the UK, and considered in the context of other factors that influence diseases and particularly emergence of new diseases, such as changes to farm practices and introductions of exotic material and effects of other environment changes such as elevated CO 2. Good crop disease control will contribute to climate change mitigation by decreasing greenhouse gas emissions from agriculture while sustaining production. Strategies for adaptation to climate change are needed to maintain disease control and crop yields in north-west Europe.Peer reviewe
Lawyer Distress: Alcohol-Related Problems and Other Psychological Concerns Among a Sample of Practicing Lawyers
Suspending an attorney\u27s license for sixty days for neglecting client matters, making misrepresentations to the district court, and failing to timely respond to the disciplinary board; his depression was a mitigating factor in imposing discipline
Lawyer Distress: Alcohol-Related Problems and Other Psychological Concerns among a Sample of Practicing Lawyers
The findings of the research reported in this study, in conjunction with earlier studies, suggest that the professional and the personal well-being of lawyers is in serious jeopardy. Lawyers are working more, reducing vacation time, spending less time with family members, are prone to alcohol abuse, and face high levels of psychological distress. The combination of elements suggests an impending crisis for lawyers\u27 family lives. Although the data are not sufficient to suggest that psychological distress has detrimentally affected the lawyers\u27 ability to practice competently, the warning signs are present. Further empirical study may well reveal that lawyer distress is having an adverse effect on the ability to practice competently and ethically
Lawyer Distress: Alcohol-Related Problems and Other Psychological Concerns Among a Sample of Practicing Lawyers
Holding that an attorney suffering from depression was suspended from the practice of law for a period of 120 days; suspension was to ensure there would be evidence of a meaningful and sustained recovery before the attorney was allowed to return to practice.
Drought and root herbivory interact to alter the response of above-ground parasitoids to aphid infested plants and associated plant volatile signals
Multitrophic interactions are likely to be altered by climate change but there is little empirical evidence relating the responses of herbivores and parasitoids to abiotic factors. Here we investigated the effects of drought on an above/belowground system comprising a generalist and a specialist aphid species (foliar herbivores), their parasitoids, and a dipteran species (root herbivore).We tested the hypotheses that: (1) high levels of drought stress and below-ground herbivory interact to reduce the performance of parasitoids developing in aphids; (2) drought stress and root herbivory change the profile of volatile organic chemicals (VOCs) emitted by the host plant; (3) parasitoids avoid ovipositing in aphids feeding on plants under drought stress and root herbivory. We examined the effect of drought, with and without root herbivory, on the olfactory response of parasitoids (preference), plant volatile emissions, parasitism success (performance), and the effect of drought on root herbivory. Under drought, percentage parasitism of aphids was reduced by about 40–55% compared with well watered plants. There was a significant interaction between drought and root herbivory on the efficacy of the two parasitoid species, drought stress partially reversing the negative effect of root herbivory on percent parasitism. In the absence of drought, root herbivory significantly reduced the performance (e.g. fecundity) of both parasitoid species developing in foliar herbivores. Plant emissions of VOCs were reduced by drought and root herbivores, and in olfactometer experiments parasitoids preferred the odour from well-watered plants compared with other treatments. The present work demonstrates that drought stress can change the outcome of interactions between herbivores feeding above- and belowground and their parasitoids, mediated by changes in the chemical signals from plants to parasitoids. This provides a new insight into how the structure of terrestrial communities may be affected by drought
Critical Point Field Mixing in an Asymmetric Lattice Gas Model
The field mixing that manifests broken particle-hole symmetry is studied for
a 2-D asymmetric lattice gas model having tunable field mixing properties.
Monte Carlo simulations within the grand canonical ensemble are used to obtain
the critical density distribution for different degrees of particle-hole
asymmetry. Except in the special case when this asymmetry vanishes, the density
distributions exhibit an antisymmetric correction to the limiting
scale-invariant form. The presence of this correction reflects the mixing of
the critical energy density into the ordering operator. Its functional form is
found to be in excellent agreement with that predicted by the mixed-field
finite-size-scaling theory of Bruce and Wilding. A computational procedure for
measuring the significant field mixing parameter is also described, and its
accuracy gauged by comparing the results with exact values obtained
analytically.Comment: 10 Pages, LaTeX + 8 figures available from author on request, To
appear in Z. Phys.
Band 3 mutations, distal renal tubular acidosis, and Southeast Asian ovalocytosis
Band 3 mutations, distal renal tubular acidosis, and Southeast Asian ovalocytosis. Familial distal renal tubular acidosis (dRTA) and Southeast Asian ovalocytosis (SAO) may coexist in the same patient. Both can originate in mutations of the anion-exchanger 1 gene (AE1), which codes for band 3, the bicarbonate/chloride exchanger in both the red cell membrane and the basolateral membrane of the collecting tubule alpha-intercalated cell. Dominant dRTA is usually due to a mutation of the AE1 gene, which does not alter red cell morphology. SAO is caused by an AE1 mutation that leads to a nine amino acid deletion of red cell band 3, but by itself does not cause dRTA. Recent gene studies have shown that AE1 mutations are responsible for autosomal recessive dRTA in several countries in Southeast Asia; these patients may be homozygous for the mutation or be compound heterozygotes of two different AE1 mutations, one of which is usually the SAO mutation
Arable crop disease control, climate change and food security
Copyright Association of Applied BiologistsGlobal food security is threatened by crop diseases that account for average yield losses of 16%. Climate change is exacerbating threats to food security in much of the world, emphasising the need to increase food production in northern European countries such as the UK. However, to mitigate climate change, crops must be grown so as to minimise greenhouse gas emissions (GHG); results with UK oilseed rape demonstrate how disease control in arable crops can contribute to climate change mitigation. However, work examining impacts of climate change on UK epidemics of winter oilseed rape diseases illustrates unexpected, contrasting impacts of climate change on complex plant-disease interactions. In England, phoma stem canker is expected to become more severe whilst light leaf spot is expected to become less severe. Such work can provide guidance for government and industry planning for adaptation to impacts of climate change on crops to ensure future food securityFinal Accepted Versio
Probability Distribution Function of the Order Parameter: Mixing Fields and Universality
We briefly review the use of the order parameter probability distribution
function as a useful tool to obtain the critical properties of statistical
mechanical models using computer Monte Carlo simulations. Some simple discrete
spin magnetic systems on a lattice, such as Ising, general spin- Blume-Capel
and Baxter-Wu, -state Potts, among other models, will be considered as
examples. The importance and the necessity of the role of mixing fields in
asymmetric magnetic models will be discussed in more detail, as well as the
corresponding distributions of the extensive conjugate variables.Comment: 14 pages, 13 figures, accepted for publication (Computer Physics
Communications
Instability and freezing in a solidifying melt conduit
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Physica D: Nonlinear Phenomena 240 (2011): 131-139, doi:10.1016/j.physd.2010.10.009.Previous works have shown that when liquid flows in a pipe whose boundary
temperature is below freezing, a tubular drainage conduit forms surrounded by solidified
material that freezes shut under the appropriate combination of forcing conditions. We
conduct laboratory experiments with wax in which the tube freezes shut below a certain
value of flux from a pump. As the flux is gradually decreased to this value, the total
pressure drop across the length of the tube first decreases to a minimum value and then
rises before freezing. Previous theoretical models of a tube driven by a constant pressure
drop suggest that once the pressure minimum is reached, the states for a lower flux
should be unstable and the tube should therefore freeze up. In our experiments, flux and
pressure drop were coupled, and this motivates us to extend the theory for low-Reynolds
number flow through a tube with solidification to incorporate a simple pressure drop-flux
relationship. Our model predicts a steady-state relationship between flux and pressure
drop that has a minimum of the pressure as the flux is varied. The stability properties of
these steady states depend on the boundary conditions: for a fixed flux, they are all stable,
whereas for fixed pressure drop, only those with a flux larger than that at the pressure
drop minimum are stable. For a mixed pressure-flux condition, the stability threshold of
the steady states lies between these two end members. This provides a possible
mechanism for the experimental observations.Support was received from the Geophysical Fluid Dynamics Program, which is
supported by the Ocean Sciences Division of the National Science Foundation under
Grant OCE-0325296, and from the Oceanography Section of the Office of Naval
Research under Grant N00014-07-1-0776. The laboratory experiments were supported by
the Deep Ocean Exploration Institute of W.H.O.I
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