274 research outputs found
Breeding for carrot resistance to Alternaria dauci without compromising taste
Developing carrot varieties highly resistant to Alternaria dauci is a top priority for breeders. Meanwhile, consumers are increasingly demanding as regards final product quality, particularly taste. Bitterness is one of the five common taste sensations, but it is rejected by most carrot consumers. Therefore, providing tools for efficient plant breeding of resistant, low bitter carrots would be helpful. While resistance QTLs (rQTLs) have already been identified for carrot resistance to A. dauci, the genetic control and mapping of the metabolites involved in bitterness perception have not been addressed so far. We identified the metabolites most involved in bitterness by combining chemical and sensory analyses of a set of resistant and susceptible carrot genotypes grown in different environments. We evaluated their genetic control and heritability in a segregating F2:3 population over 2 years of field trials and searched for colocalizations between rQTLs and metabolite QTLs (mQTLs) to evaluate the link between bitterness and resistance traits. Our results suggest that it is possible to increase resistance while favoring low bitter varieties by selecting genomic regions involved in the expression of one or the other trait and counter-selecting others when r- and mQTL colocalization is unfavorable
ENMTools 1.0: an R package for comparative ecological biogeography
The ENMTools software package was introduced in 2008 as a platform for making measurements on environmental niche models (ENMs, frequently referred to as species distribution models or SDMs), and for using those measurements in the context of newly developed Monte Carlo tests to evaluate hypotheses regarding niche evolution. Additional functionality was later added for model selection and simulation from ENMs, and the software package has been quite widely used. ENMTools was initially implemented as a Perl script, which was also compiled into an executable file for various platforms. However, the package had a number of significant limitations; it was only designed to fit models using Maxent, it relied on a specific Perl distribution to function, and its internal structure made it difficult to maintain and expand. Subsequently, the R programming language became the platform of choice for most ENM studies, making ENMTools less usable for many practitioners. Here we introduce a new R version of ENMTools that implements much of the functionality of its predecessor as well as numerous additions that simplify the construction, comparison and evaluation of niche models. These additions include new metrics for model fit, methods of measuring ENM overlap, and methods for testing evolutionary hypotheses. The new version of ENMTools is also designed to work within the expanding universe of R tools for ecological biogeography, and as such includes greatly simplified interfaces for analyses from several other R packages
The GANIL control system as seen from the control room
http://accelconf.web.cern.ch/AccelConf/c81/papers/fp-08.pdfInternational audienc
Finite Theories and the SUSY Flavor Problem
We study a finite SU(5) grand unified model based on the non-Abelian discrete
symmetry A_4. This model leads to the democratic structure of the mass matrices
for the quarks and leptons. In the soft supersymmetry breaking sector, the
scalar trilinear couplings are aligned and the soft scalar masses are
degenerate, thus solving the SUSY flavor problem.Comment: 17 pages, LaTeX, 1 figur
The known unknowns of hydraulic engineering
Hydraulic engineers and researchers deal with scientific challenges involving turbulent flow motion and its interactions with the surroundings. Turbulent flows are characterised by unpredictable behaviour, and little systematic research has yet been conducted in natural systems. This paper discusses the implications of recent developments in affordable instrumentation previously characterised by intrinsic weaknesses that adversely affect the quality of the signal outputs. A challenging application is the unsteady turbulence field in tidal bores. The interactions between open channel flows and movable boundaries and atmosphere illustrate another aspect of our limited knowledge. Rapid siltation of reservoirs and air entrainment in turbulent free-surface flows are discussed. In both applications, hydraulic engineers require some broad-based expertise. In turn the education of future hydraulic engineers is of vital importance
The histone binding capacity of SPT2 controls chromatin structure and function in Metazoa
Histone chaperones control nucleosome density and chromatin structure. In yeast, the H3-H4 chaperone Spt2 controls histone deposition at active genes but its roles in metazoan chromatin structure and organismal physiology are not known. Here we identify the Caenorhabditis elegans ortholog of SPT2 (CeSPT-2) and show that its ability to bind histones H3-H4 is important for germline development and transgenerational epigenetic gene silencing, and that spt-2 null mutants display signatures of a global stress response. Genome-wide profiling showed that CeSPT-2 binds to a range of highly expressed genes, and we find that spt-2 mutants have increased chromatin accessibility at a subset of these loci. We also show that SPT2 influences chromatin structure and controls the levels of soluble and chromatin-bound H3.3 in human cells. Our work reveals roles for SPT2 in controlling chromatin structure and function in Metazoa.</p
Corporate political activity in less developed countries:The Volta River Project in Ghana, 1958-66
The article expands existing categorisations of political and economic governance by including literature on less developed countries (LDCs). In four consecutive negotiations between the US multinational Kaisers and the US and Ghana governments in the early 1960s, it is argued that the company reached levels of influence that are at odds with existing explanations. In order to understand corporate political activities in LDCs, analysis needs to go beyond static factors (political risk) and include dynamic factors such as diplomatic relations and 'arenas of power', and consider the role of the investor's home country relative to the host economy
Potent Antioxidant and Genoprotective Effects of Boeravinone G, a Rotenoid Isolated from Boerhaavia diffusa
Background and Aims: Free radicals are implicated in the aetiology of some gastrointestinal disorders such as gastric ulcer, colorectal cancer and inflammatory bowel disease. In the present study we investigated the antioxidant and genoprotective activity of some rotenoids (i.e. boeravinones) isolated from the roots of Boerhaavia diffusa, a plant used in the Ayurvedic medicine for the treatment of diseases affecting the gastrointestinal tract. Methods/Principal Findings: Antioxidant activity has been evaluated using both chemical (Electron Spin Resonance spectroscopy, ESR) and Caco-2 cells-based (TBARS and ROS) assays. DNA damage was evaluated by Comet assay, while pERK 1/2 and phospho-NF-kB p65 levels were estimated by western blot. Boeravinones G, D and H significantly reduced the signal intensity of ESR induced by hydroxyl radicals, suggesting a scavenging activity. Among rotenoids tested, boeravinone G exerted the most potent effect. Boeravinone G inhibited both TBARS and ROS formation induced by Fenton's reagent, increased SOD activity and reduced H 2O 2-induced DNA damage. Finally, boeravinone G reduced the levels of pERK 1 and phospho-NF-kB p65 (but not of pERK 2) increased by Fenton's reagent. Conclusions: It is concluded that boeravinone G exhibits an extraordinary potent antioxidant activity (significant effect in the nanomolar range). The MAP kinase and NF-kB pathways seem to be involved in the antioxidant effect of boeravinone G. Boeravinone G might be considered as lead compound for the development of drugs potentially useful against those pathologies whose aetiology is related to ROS-mediated injuries
Intensive enteral nutrition is ineffective for individuals with severe alcoholic hepatitis treated with corticosteroids.
peer reviewedBACKGROUND & AIMS: Severe alcoholic hepatitis (AH) is a lifethreatening
disease for which adequate oral nutritional support
is recommended. We performed a randomized controlled trial to
determine whether the combination of corticosteroid and
intensive enteral nutrition therapy is more effective than corticosteroid
therapy alone in patients with severe AH. METHODS:
We enrolled 136 heavy consumers of alcohol (age, 18–75 y)
with recent onset of jaundice and biopsy-proven severe AH in
our study, performed at 18 hospitals in Belgium and 2 in
France, from February 2010 through February 2013. Subjects
were assigned randomly (1:1) to groups that received either
intensive enteral nutrition plus methylprednisolone or conventional
nutrition plus methylprednisolone (controls). In the
intensive enteral nutrition group, enteral nutrition was given
via feeding tube for 14 days. The primary end point was patient
survival for 6 months. RESULTS: In an intention-to-treat analysis,
we found no significant difference between groups in
6-month cumulative mortality: 44.4% of patients died in the
intensive enteral nutrition group (95% confidence interval [CI],
32.2%–55.9%) and 52.1% of controls died (95% CI, 39.4%–
63.4%) (P ¼ .406). The enteral feeding tube was withdrawn
prematurely from 48.5% of patients, and serious adverse
events considered to be related to enteral nutrition occurred in
5 patients. Regardless of group, a greater proportion of patients
with a daily calorie intake less than 21.5 kcal/kg/day died
(65.8%; 95% CI, 48.8–78.4) than patients with a higher intake
of calories (33.1%; 95% CI, 23.1%–43.4%) (P < .001).
CONCLUSIONS: In a randomized trial of patients with severe AH
treated with corticosteroids, we found that intensive enteral
nutrition was difficult to implement and did not increase survival.
However, low daily energy intake was associated with greater
mortality, so adequate nutritional intake should be a main goal for
treatment
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