7,021 research outputs found
Single Amino Acid Substitution the DNA Repairing Gene Radiation-Sensitive 4 Contributes to Ultraviolet Tolerance of a Plant Pathogen
To successfully survive and reproduce, all species constantly modify the structure and expression of their genomes to cope with changing environmental conditions including ultraviolet (UV) radiation. Thus, knowledge of species adaptation to environmental changes is a central theme of evolutionary studies which could have important implication for disease management and social-ecological sustainability in the future but is generally insufficient. Here, we investigated the evolution of UV adaptation in organisms by population genetic analysis of sequence structure, physiochemistry, transcription, and fitness variation in the radiation-sensitive 4 (RAD4) gene of the Irish potato famine pathogen Phytophthora infestans sampled from various altitudes. We found that RAD4 is a key gene determining the resistance of the pathogen to UV stress as indicated by strong phenotype-genotype-geography associations and upregulated transcription after UV exposure. We also found conserved evolution in the RAD4 gene. Only five nucleotide haplotypes corresponding to three protein isoforms generated by point mutations were detected in the 140 sequences analyzed and the mutations were constrained to the N-terminal domain of the protein. Physiochemical changes associated with non-synonymous mutations generate severe fitness penalty to mutants, which are purged out by natural selection, leading to the conserved evolution observed in the gene
Contribution of starburst mergers at z~1 to the strong evolution of infrared and submillimeter deep surveys
Recent FIR/submm deep surveys revealed large number of ULIGs, which are
proposed to lie at z>1, and in normally interacting systems with very dusty
environments. We discussed in a previous paper that a population with a fast
evolving infrared burst phase triggered by gas rich mergers at z~1 interpreted
successfully the steep slope of IRAS 60um counts, leaving still a reasonable
CIRB level at this wavelength. To extend the model to mid- and far-IR, we adopt
a template SED as typical for nearby IR bright galaxies, such as Arp220. We
construct the SED for the starburst mergers at z~1 by a simple dust extinction
law and a thermal continuum assumption for the FIR emission. Since the
radiation process at MIR for the merging systems is still uncertain, we assume
it is similar to that of Arp220, but modify it by the observed flux correlation
of ULIGs from IRAS, ISOCAM deep surveys. We show in this paper that the strong
evolution of the ELAIS 90um, ISO 170um and the SCUBA 850um could be
sufficiently accounted for by such an evolutionary scenario, especially for the
hump of the ISOCAM 15um source count around 0.4mJy. From current best fit
results, we find that the dust temperature of those merging system at z~1 would
be higher than that of Arp220 for a reconciliation of the multi-wavelength deep
surveys. The major difference of our current model prediction is that we see a
fast convergence of the differential number counts at 60um below 50mJy, which
is about a factor of two brighter than other model predictions. Future IR
satellite like Astro-F,SIRTF would give strong constraints to the models.Comment: 9 pages, 7 figures, Accepted by A&A. Minor changes to the contents
and citatio
Clustering of psychiatric and somatic illnesses in the general population: multimorbidity and socioeconomic correlates
The distribution of psychiatric disorders and of chronic medical illnesses was studied in a population-based sample to determine whether these conditions co-occur in the same individual. A representative sample (N = 1464) of adults living in households was assessed by the Composite International Diagnostic Interview, version 1.1, as part of the São Paulo Epidemiological Catchment Area Study. The association of sociodemographic variables and psychological symptoms regarding medical illness multimorbidity (8 lifetime somatic conditions) and psychiatric multimorbidity (15 lifetime psychiatric disorders) was determined by negative binomial regression. A total of 1785 chronic medical conditions and 1163 psychiatric conditions were detected in the population concentrated in 34.1 and 20% of respondents, respectively. Subjects reporting more psychiatric disorders had more medical illnesses. Characteristics such as age range (35-59 years, risk ratio (RR) = 1.3, and more than 60 years, RR = 1.7), being separated (RR = 1.2), being a student (protective effect, RR = 0.7), being of low educational level (RR = 1.2) and being psychologically distressed (RR = 1.1) were determinants of medical conditions. Age (35-59 years, RR = 1.2, and more than 60 years, RR = 0.5), being retired (RR = 2.5), and being psychologically distressed (females, RR = 1.5, and males, RR = 1.4) were determinants of psychiatric disorders. In conclusion, psychological distress and some sociodemographic features such as age, marital status, occupational status, educational level, and gender are associated with psychiatric and medical multimorbidity. The distribution of both types of morbidity suggests the need of integrating mental health into general clinical settings
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