12 research outputs found
Karyotype, Sex Determination, and Meiotic Chromosome Behavior in Two Pholcid (Araneomorphae, Pholcidae) Spiders: Implications for Karyotype Evolution
There are 1,111 species of pholcid spiders, of which less than 2% have published karyotypes. Our aim in this study was to determine the karyotypes and sex determination mechanisms of two species of pholcids: Physocyclus mexicanus (Banks, 1898) and Holocnemus pluchei (Scopoli, 1763), and to observe sex chromosome behavior during meiosis. We constructed karyotypes for P. mexicanus and H. pluchei using information from both living and fixed cells. We found that P. mexicanus has a chromosome number of 2n = 15 in males and 2n = 16 in females with X0-XX sex determination, like other members of the genus Physocyclus. H. pluchei has a chromosome number of 2n = 28 in males and 2n = 28 in females with XY-XX sex determination, which is substantially different from its closest relatives. These data contribute to our knowledge of the evolution of this large and geographically ubiquitous family, and are the first evidence of XY-XX sex determination in pholcids
Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study
Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation
Atmosfera modificada e 1-metilciclopropeno na conservação pós-colheita de kiwis cv. Bruno Modified atmosphere and 1-methylciclopropene on postharvest conservation of kiwis cv. Bruno
Neste trabalho avaliou-se, em kiwis da cv Bruno, a ação do 1-Metilciclopropeno (1-MCP), na concentração de 625 ppb, associado ou não à atmosfera modificada gerada com o emprego de embalagem de polietileno de baixa densidade (PEBD), de 22µm. Os tratamentos testados foram: T1, controle (sem embalagem e 1-MCP); T2, sem embalagem com 1-MCP; T3, com embalagem de PEBD sem 1-MCP; T4, embalagem de PEBD mais o 1-MCP, sendo após armazenados em câmara fria a - 0,5 ± 0,5 ºC e 95 ± 5% de umidade relativa (U.R.). As avaliações foram realizadas após o pré-resfriamento, aos 45 dias, 45 + 5 dias (22 ± 3ºC e 75 ± 5% de U.R.), 90 dias e 90 + 5 dias (22 ± 3ºC e 75 ± 5% de U.R.). As variáveis analisadas foram: firmeza de polpa (FP), sólidos totais (ST), acidez titulável (AT), concentração de etileno e de CO2 e análise sensorial (somente ao final do experimento). A maior firmeza de polpa e acidez titulável, o menor conteúdo de sólidos totais, as menores concentrações de etileno e CO2 e a melhor aceitabilidade pelos julgadores foi obtida com os frutos acondicionadas em PEBD de 22 µm e tratadas com 1-MCP.<br>In this work was evaluated, for kiwis cv. Bruno, the Methylcyclopropene action (1-MCP), in concentration of 625 ppb, associated or not with modified atmosphere (MA) using low density polyethylene bags (LDPE) of 22µm. The following treatments were tested: T1: control (no bags and 1-MCP); T2 no bags with 1-MCP; T3 LDPE bags no 1-MCP; T4 LDPE bags and 1-MCP, then they were stored in cold chamber at - 0,5 ± 0,5 ºC and 95 ± 5% of RH for 45 or 90 days. The fruits were evaluated after pre-cooling, 45 days, 45 + 5 days (22 ± 3ºC and 75 ± 5% of RH.), 90 days and 90 + 5 days (22 ± 3ºC and 75 ± 5% of RH.). The parameters analyzed were: pulp firmness (PF), total solids (TS), titritable acidity (TA), ethylene and CO2 concentration, and sensorial analyzes (only in the end of the experiment). The largest pulp firmness and titritable acidity, the smaller content of total soluble, the smaller concentration of ethylene and CO2 and the better acceptability for the taste panel was obtained with the fruits stored in LDPE of 22 µm and treated with 1-MCP
Calculation of the Average Cost per Case of Dengue Fever in Mexico Using a Micro-Costing Approach
Activator–inhibitor coupling between Rho signalling and actin assembly makes the cell cortex an excitable medium
Optimization of adsorptive removal of α-toluic acid by CaO2 nanoparticles using response surface methodology
The present work addresses the optimization of process parameters for adsorptive removal of α-toluic acid by calcium peroxide (CaO2) nanoparticles using response surface methodology (RSM). CaO2 nanoparticles were synthesized by chemical precipitation method and confirmed by Transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) analysis which shows the CaO2 nanoparticles size range of 5–15 nm. A series of batch adsorption experiments were performed using CaO2 nanoparticles to remove α-toluic acid from the aqueous solution. Further, an experimental based central composite design (CCD) was developed to study the interactive effect of CaO2 adsorbent dosage, initial concentration of α-toluic acid, and contact time on α-toluic acid removal efficiency (response) and optimization of the process. Analysis of variance (ANOVA) was performed to determine the significance of the individual and the interactive effects of variables on the response. The model predicted response showed a good agreement with the experimental response, and the coefficient of determination, (R2) was 0.92. Among the variables, the interactive effect of adsorbent dosage and the initial α-toluic acid concentration was found to have more influence on the response than the contact time. Numerical optimization of process by RSM showed the optimal adsorbent dosage, initial concentration of α-toluic acid, and contact time as 0.03 g, 7.06 g/L, and 34 min respectively. The predicted removal efficiency was 99.50%. The experiments performed under these conditions showed α-toluic acid removal efficiency up to 98.05%, which confirmed the adequacy of the model prediction
Clinical manifestations of intermediate allele carriers in Huntington disease
Objective: There is controversy about the clinical consequences of intermediate alleles (IAs) in Huntington disease (HD). The main objective of this study was to establish the clinical manifestations of IA carriers for a prospective, international, European HD registry. Methods: We assessed a cohort of participants at risk with <36 CAG repeats of the huntingtin (HTT) gene. Outcome measures were the Unified Huntington's Disease Rating Scale (UHDRS) motor, cognitive, and behavior domains, Total Functional Capacity (TFC), and quality of life (Short Form-36 [SF-36]). This cohort was subdivided into IA carriers (27-35 CAG) and controls (<27 CAG) and younger vs older participants. IA carriers and controls were compared for sociodemographic, environmental, and outcome measures. We used regression analysis to estimate the association of age and CAG repeats on the UHDRS scores. Results: Of 12,190 participants, 657 (5.38%) with <36 CAG repeats were identified: 76 IA carriers (11.56%) and 581 controls (88.44%). After correcting for multiple comparisons, at baseline, we found no significant differences between IA carriers and controls for total UHDRS motor, SF-36, behavioral, cognitive, or TFC scores. However, older participants with IAs had higher chorea scores compared to controls (p 0.001). Linear regression analysis showed that aging was the most contributing factor to increased UHDRS motor scores (p 0.002). On the other hand, 1-year follow-up data analysis showed IA carriers had greater cognitive decline compared to controls (p 0.002). Conclusions: Although aging worsened the UHDRS scores independently of the genetic status, IAs might confer a late-onset abnormal motor and cognitive phenotype. These results might have important implications for genetic counseling. ClinicalTrials.gov identifier: NCT01590589