282 resultados para STERILITY


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Increased rates of nitrogen fertilizer application lead to increased spikelet sterility. A field experiment was conducted to investigate the effects on engorged pollen production and spikelet sterility, of nitrogen and assimilate availability during microspore development, in two rice cultivars (Doongara and Amaroo) grown under two different water depths. Despite the temperature not being low enough during microspore development to cause spikelet sterility, the number of engorged pollen grains was lower in cv. Doongara than in cv. Amaroo. Nitrogen application decreased the number of engorged pollen grains per anther through increased spikelet density. Nitrogen application increased spikelet sterility as a result of increased panicle density showing pronounced indirect effect of N on spikelet sterility. Engorged pollen number was also closely related (r = -0.636*) to the nitrogen content of the leaf blade, indicating a direct negative effect of plant N status on engorged pollen production. The results suggest that the intrinsic pollen producing ability is the key element in the difference in cold tolerance between the two cultivars, particularly under high N rates. Opening the canopy for increased solar radiation interception by the treated plants increased the level of engorged pollen, indicating the importance of immediate assimilate availability for engorged pollen production. Shading reduced crop growth rate, but did not effect engorged pollen production. There was no effect of variation in assimilates production on spikelet sterility.

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Objective: This study investigated: (i) the prevalence of ureaplasmas in semen and washed semen and (ii) the effect of ureaplasmas on semen andrology parameters. Design: Prospective study. Setting: IVF unit -private hospital, Brisbane, Australia. Patient(s): Three hundred and forty three men participating in an assisted reproductive technology (ART) treatment cycle. Intervention(s): Semen and washed semen tested by culture, PCR assays and indirect immunofluorescent antibody assays. Statistical differences were determined by a t-test, Wilcoxon or Pearson’s Chi- square test where appropriate. Main Outcome Measure(s): The prevalence of ureaplasmas in semen and washed semen and the effect of these microorganisms on semen andrology parameters. Result(s): Ureaplasmas were detected in 73/343 (22%) semen samples and 29/343 (8.5%) washed semen samples. Ureaplasmas adherent to the surface of spermatozoa were demonstrated by indirect immunofluorescent antibody testing. U. parvum serovar 6 (36.6%) and U. urealyticum (30%) were the most prevalent isolates in washed semen. A comparison of the semen andrology parameters of washed semen ureaplasma positive and negative groups demonstrated a lower proportion of non-motile sperm in the washed semen ureaplasma positive group. Conclusion(s): Ureaplasmas are not always removed from semen by a standard ART washing procedure and can remain adherent to the surface of spermatozoa.

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Objective: To investigate the mental and general health of infertile women who had not sought medical advice for their recognized infertility and were therefore not represented in clinical populations. Design: Longitudinal cohort study.Setting Population based.Patient(s) Participants in the Australian Longitudinal Study on Women's Health aged 28-33 years in 2006 who had ever tried to conceive or had been pregnant (n = 5,936).Intervention(s) None.Main Outcome Measure(s) Infertility, not seeking medical advice. Result(s): Compared with fertile women (n = 4,905), infertile women (n = 1,031) had higher odds of self-reported depression (odds ratio [OR] 1.20, 95% confidence interval [CI] 1.01-1.43), endometriosis (5.43, 4.01-7.36), polycystic ovary syndrome (9.52, 7.30-12.41), irregular periods (1.99, 1.68-2.36), type II diabetes (4.70, 1.79-12.37), or gestational diabetes (1.66, 1.12-2.46). Compared with infertile women who sought medical advice (n = 728), those who had not sought medical advice (n = 303) had higher odds of self-reported depression (1.67, 1.18-2.37), other mental health problems (3.14, 1.14-8.64), urinary tract infections (1.67, 1.12-2.49), heavy periods (1.63, 1.16-2.29), or a cancer diagnosis (11.33, 2.57-49.89). Infertile women who had or had not sought medical advice had similar odds of reporting an anxiety disorder or anxiety-related symptoms. Conclusion(s): Women with self-reported depression were unlikely to have sought medical advice for infertility. Depression and depressive symptoms may be barriers to seeking medical advice for infertility.

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Objective To examine the extent to which the odds of birth, pregnancy, or adverse birth outcomes are higher among women aged 28 to 36 years who use fertility treatment compared with untreated women. Design Prospective, population-based. Setting Not applicable. Patient(s) Participants in the ALSWH born in 1973 to 1978 who reported on their infertility and use of in vitro fertilization (IVF) or ovulation induction (OI). Intervention(s) Postal survey questionnaires administered as part of ALSWH. Main Outcome Measure(s) Among women treated with IVF or OI and untreated women, the odds of birth outcomes estimated by use of adjusted logistic regression modeling. Result(s) Among 7,280 women, 18.6% (n = 1,376) reported infertility. Half (53.0%) of the treated women gave birth compared with 43.8% of untreated women. Women with prior parity were less likely to use IVF compared with nulliparous women. Women using IVF or OI, respectively, were more likely to have given birth after treatment or be pregnant compared with untreated women. Women using IVF or OI were as likely to have ectopic pregnancies, stillbirths, or premature or low birthweight babies as untreated women. Conclusion(s) More than 40% of women aged 28–36 years reporting a history of infertility can achieve births without using treatment, indicating they are subfertile rather than infertile.

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A simulation-based training system for surgical wound debridement was developed and comprises a multimedia introduction, a surgical simulator (tutorial component), and an assessment component. The simulator includes two PCs, a haptic device, and mirrored display. Debridement is performed on a virtual leg model with a shallow laceration wound superimposed. Trainees are instructed to remove debris with forceps, scrub with a brush, and rinse with saline solution to maintain sterility. Research and development issues currently under investigation include tissue deformation models using mass-spring system and finite element methods; tissue cutting using a high-resolution volumetric mesh and dynamic topology; and accurate collision detection, cutting, and soft-body haptic rendering for two devices within the same haptic space.

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Two BRCA2-like sequences are present in the Arabidopsis genome. Both genes are expressed in flower buds and encode nearly identical proteins, which contain four BRC motifs. In a yeast two-hybrid assay, the Arabidopsis Brca2 proteins interact with Rad51 and Dmc1. RNAi constructs aimed at silencing the BRCA2 genes at meiosis triggered a reproducible sterility phenotype, which was associated with dramatic meiosis alterations. We obtained the same phenotype upon introduction of RNAi constructs aimed at silencing the RAD51 gene at meiosis in dmc1 mutant plants. The meiotic figures we observed strongly suggest that homologous recombination is highly disturbed in these meiotic cells, leaving aberrant recombination events to repair the meiotic double-strand breaks. The 'brca2' meiotic phenotype was eliminated in spo11 mutant plants. Our experiments point to an essential role of Brca2 at meiosis in Arabidopsis. We also propose a role for Rad51 in the dmc1 context.

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Objective: To follow-up previous studies highlighting a possible role for cytochrome P450, family 2, subfamily C, 19 (CYP2C19) in susceptibility to endometriosis by searching for additional variants in the CYP2C19 gene that may be associated with the disease. Design Case-control study. Setting Academic research. Subject(s) The cases comprised 2,271 women with surgically confirmed endometriosis; the controls comprised 939 women with self-report of no endometriosis and 1,770 unscreened population samples. Intervention(s) Sequencing of the CYP2C19 region and follow-up of 80 single nucleotide polymorphisms (SNPs) in two case-control samples. Main Outcome Measure(s) Allele frequency differences between cases and controls. Result(s) Sequencing of the CYP2C19 gene region resulted in the detection of a large number of known and novel SNPs. Genotyping of 80 polymorphic SNPs in 901 endometriosis cases and 939 controls resulted in study-wide significant association signals for SNPs in moderate or complete linkage disequilibrium with rs4244285, a functional SNP in exon 5 that abrogates CYP2C19 function through the creation of an alternative splice site. Evidence of association was also detected for another functional SNP in the CYP2C19 promoter, rs12248560, which was highlighted in our previous study. Conclusion(s) Functional variants in CYP2C19 may contribute to endometriosis susceptibility in both familial and sporadic cases. © 2014 by American Society for Reproductive Medicine.

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Aseptic processing involves sterilising the product and package separately, and filling under sterile conditions. Advantages include better product quality compared with canned products, lower transport and storage costs compared with frozen products, and virtually no restriction on package size. Problems include ensuring adequate heat penetration into the particles to ensure sterility, preventing separation of particles from the carrier liquid, and retention of particle structure and shape. Particulate foods can be sterilised in scraped - surface heat exchangers. Other methods involve heating the particles separately, and combining them during filling. Projects will commence at the International Food Institute of Queensland (IFIQ) on aseptic packaging of a meat and vegetable product, and aseptically packaged mango pieces.

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Aseptic processing involves sterilising the product (most meat products being low-acid foods containing particulates) and package separately, and filling under sterile conditions. Advantages include better product quality compared with canned products, lower transport and storage costs compared with frozen products, and virtually no restriction on package size. Problems include ensuring adequate heat penetration into the particles to ensure sterility, preventing separation of particles from the carrier liquid, and retention of particle structure and shape. Particulate foods can be sterilised in scraped-surface heat exchangers. Other methods involve heating the particles separately, and combining them during filling. The effects of aseptic processing on meat product quality (colour, flavour, texture, and mutrition) are outlined in this paper.

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OBJECTIVE To refine a previously reported linkage peak for endometriosis on chromosome 10q26, and conduct follow-up analyses and a fine-mapping association study across the region to identify new candidate genes for endometriosis. DESIGN Case-control study. SETTING Academic research. PATIENT(S) Cases=3,223 women with surgically confirmed endometriosis; controls=1,190 women without endometriosis and 7,060 population samples. INTERVENTION(S) Analysis of 11,984 single nucleotide polymorphisms on chromosome 10. MAIN OUTCOME MEASURE(S) Allele frequency differences between cases and controls. RESULT(S) Linkage analyses on families grouped by endometriosis symptoms (primarily subfertility) provided increased evidence for linkage (logarithm of odds score=3.62) near a previously reported linkage peak. Three independent association signals were found at 96.59 Mb (rs11592737), 105.63 Mb (rs1253130), and 124.25 Mb (rs2250804). Analyses including only samples from linkage families supported the association at all three regions. However, only rs11592737 in the cytochrome P450 subfamily C (CYP2C19) gene was replicated in an independent sample of 2,079 cases and 7,060 population controls. CONCLUSION(S) The role of the CYP2C19 gene in conferring risk for endometriosis warrants further investigation.

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ICRISAT scientists, working with Indian programme counterparts, developed the world's first cytoplasmic-nuclear male sterility (CMS)-based commercial hybrid in a food legume, the pigeonpea [Cajanus cajan (L.) Millsp.]. The CMS, in combination with natural outcrossing of the crop, was used to develop viable hybrid breeding technology. Hybrid ICPH 2671 recorded 47% superiority for grain yield over the control variety ‘Maruti’ in multilocation on-station testing for 4 years. In the on-farm trials conducted in five Indian states, mean yield of this hybrid (1396 kg/ha) was 46.5% greater than that of the popular cv. ‘Maruti’ (953 kg/ha). Hybrid ICPH 2671 also exhibited high levels of resistance to Fusarium wilt and sterility mosaic diseases. The outstanding performance of this hybrid has led to its release for cultivation in India by both a private seed company (as ‘Pushkal’) and a public sector university (as ‘RV ICPH 2671’). Recent developments in hybrid breeding technology and high yield advantages realized in farmers' fields have given hope for a breakthrough in pigeonpea productivity.