458 research outputs found
Sulphate Reduction in Partially Sterilized Soil Exposed to Air
SUMMARY: H2S was evolved from soil treated with CCl4 when moistened with sucrose and (NH4)2SO4 solution and incubated aerobically. H2S formation took place when the soil moisture was less than field capacity, and over a range of pH values from 5 to 8. The organism responsible was isolated and identified as Bacillus megaterium. Several strains of this organism reduced sulphate in well-aerated sterilized soil and liquid media but not in soil or liquid incubated anaerobically.
The action of CCl4 in fresh soil is to check or destroy certain fungi and bacteria which normally inhibit sulphate reduction by B. megaterium. Some of these organisms were isolated and shown to be sensitive to CCl4 and to inhibit sulphate reduction by B. megaterium in sterilized soil. The isolates did not exhibit antibiotic action when grown in certain defined media
RESP-321
Studies on fast and slow growing Rhizobium spp. nodulating Cajanus cajan and Cicer arietinum
Fast and slow growing Rhizobium spp. isolated from Cajanus cajan and Cicer arietinum were compared in terms of colony characteristics, utilisation of carbon sources, acid production, symbiotic effectiveness and nodulating competitiveness. Fast growing isolates from C. cajan and C. arietinum formed 3–6 mm diameter colonies on yeast-extract mannitol agar after 4 days and were unlike the slow growers which produced colonies of c. 1 mm diameter after 7–10 days at 28 °C. The fast growing Rhizobium spp. from C. cajan utilised a wider range of carbon sources than the slow growing isolates from this host. Fast and slow growing strains from C. arietinum were able to utilise most of the carbon sources tested suggesting that the slow growers possessed glycolytic pathways similar to those in other fast growing species of Rhizobium. In culture, slow growing isolates from C. cajan produced a near-neutral to alkaline reaction (pH 66·7-5) whereas the fast growers from this host and both fast and slow growing isolates from C. arietinum produced an acidic reaction (pH 4·4–5·6). These data are discussed in the context of Norris' (1965) evolutionary concept of the Leguminosae. Under glassshouse conditions, fast and slow growing strains isolated from C. cajan and C. arietinum were equally effective on their respective hosts. In competition with slow growing rhizobia, half of the fast growers formed more than 70% of the nodules on C. cajan grown in sand. In all but one instance similar results were obtained when plants were grown in soil. With C. arietinum grown in sand or soil, all fast growing isolates from this host formed more than 85% of the nodules in competition with slow growing strains
Seminal “priming” for protection from pre-eclampsia-a unifying hypothesis
Abstract Conventional belief holds that an immune response to ejaculate antigens should interfere with fertilisation and establishment of pregnancy. However, emerging evidence now supports the opposing view */that insemination acts to activate maternal immune mechanisms exerting a positive effect on reproductive events. In a response well documented in rodents, semen triggers an influx of antigen-presenting cells into the female reproductive tract which process and present paternal ejaculate antigens to elicit activation of lymphocytes in the adaptive immune compartment. Transforming growth factor beta (TGFb), a cytokine present in abundance in seminal plasma, initiates this inflammatory response by stimulating the synthesis of pro-inflammatory cytokines and chemokines in uterine tissues. Lymphocyte activation is evident in lymph nodes draining the uterus and leads to hypo-responsiveness in T-cells reactive with paternal alloantigens. TGFb has potent immune-deviating effects and is likely to be the key agent in skewing the immune response against a Type-1 bias. Prior exposure to semen in the context of TGFb can be shown to be associated with enhanced fetal Á/placental development late in gestation. In this paper, we review the experimental basis for these claims and propose the hypothesis that, in women, the partner-specific protective effect of insemination in pre-eclampsia might be explained by induction of immunological hyporesponsiveness conferring tolerance to histocompatibility antigens present in the ejaculate and shared by the conceptus.
Direct amplification of nodD from community DNA reveals the genetic diversity of Rhizobium leguminosarum in soil
Sequences of nodD, a gene found only in rhizobia, were amplified from total community DNA isolated from a pasture soil. The polymerase chain reaction (PCR) primers used, Y5 and Y6, match nodD from Rhizobium leguminosarum biovar trifolii, R. leguminosarum biovar viciae and Sinorhizobium meliloti. The PCR product was cloned and yielded 68 clones that were identified by restriction pattern as derived from biovar trifolii [11 restriction fragment length polymorphism (RFLP) types] and 15 clones identified as viciae (seven RFLP types). These identifications were confirmed by sequencing. There were no clones related to S. meliloti nodD. For comparison, 122 strains were isolated from nodules of white clover (Trifolium repens) growing at the field site, and 134 from nodules on trap plants of T. repens inoculated with the soil. The nodule isolates were of four nodD RFLP types, with 77% being of a single type. All four of these patterns were also found among the clones from soil DNA, and the same type was the most abundant, although it made up only 34% of the trifolii-like clones. We conclude that clover selects specific genotypes from the available soil population, and that R. leguminosarum biovar trifolii was approximately five times more abundant than biovar viciae in this pasture soil, whereas S. meliloti was rare
The prevalence of hypertension among Malaysian adults and its associated risk factors: data from Malaysian Community Salt Study (MyCoSS)
Background
Hypertension is one of the most common risk factors for cardiovascular disease and leading cause of mortality globally. The aims of this study were to assess the prevalence of hypertension and its associated risk factors among Malaysian population using data from the Malaysian Community Salt Study (MyCoSS).
Methods
This study was a cross-sectional study using multi-stage stratified sampling method. Data collection was carried out via face-to-face interview at the respondent’s home from October 2017 until March 2018. A total of 1047 respondents aged 18 years and above completed the questionnaires and blood pressure measurement. A person who reported diagnosis of hypertension by a physician and had systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg on three readings was categorised as hypertensive. Risk factors of hypertension were analysed using multiple logistic regression.
Results
The prevalence of hypertension in the present study was 49.39% (95% CI 44.27–54.51). There was no statistically significant difference in gender. Age, household income, BMI, and diabetes were significantly associated with hypertension. Hypertension found had inverse association with the level of education. Age was the strongest predictor of hypertension (35–44 years old; OR=2.39, 95% CI=1.39–4.09, 45–54 years old; OR=5.50, 95% CI=3.23–9.38, 55–64 years old OR=13.56, 95% CI=7.77–23.64 and 65 years old and above; OR=25.28, 95% CI=13.33–48.66). Those who had higher BMI more likely to be hypertensive as compared to respondents with normal weight (overweight, OR=1.84; 95% CI=1.18–2.86; obese, OR=4.29% CI=2.56–7.29).
Conclusion
The findings showed that hypertension is prevalent among adults in Malaysia. Those with older age, higher BMI, and diabetes are more likely to have hypertension. Efforts regarding lifestyle modification and education could be important in hypertension management and prevention
Atmospheric change causes declines in woodland arthropods and impacts specific trophic groups
1. Arthropod assemblages form a fundamental part of terrestrial ecosystems, underpinning ecosystem processes and services. Yet, little is known about how invertebrate communities, as a whole, respond to climatic and atmospheric changes, including predicted increases in carbon dioxide concentrations (CO2).
2. To date, woodland Free Air CO2 Enrichment (FACE) studies have focused entirely on northern hemisphere managed plantations. We manipulated atmospheric CO2 in a mature, native Eucalyptus woodland (0.15 ha, >32 000 m3) in Australia, using the Eucalyptus FACE (‘EucFACE’) facility. We used three complementary sampling methods (vacuum sampling, pitfall and sticky trapping) to record invertebrate abundances under ambient and elevated levels of CO2 (400 versus 550 ppm).
3. Based on the collection of over 83 000 invertebrates, we found significant declines in the overall abundance of ground-dwelling (14.7%) and aerial (12.9%) arthropods under elevated CO2, with significant decreases in herbivore, omnivore, scavenger and parasitoid functional groups. Even though several groups showed varying declines in abundance, elevated CO2 did not measurably affect community composition.
4. The results of the present study indicate that atmospheric CO2 levels predicted within the next 35 years may cause declines in arthropod abundances in Eucalyptus woodland. Declines found in several functional groups suggest that elevated atmospheric CO2 has the potential to affect ecosystem processes, possibly including nutrient cycling by herbivores and omnivores, as well as biocontrol by parasitoids
Registration of Tifrust-14 Peanut Germplasm1 (Reg. No. GP31)
THE peanut (Arachis hypogaea L.) line Tifrust-14 was developed
cooperatively by ARS-USDAt,h e Univ. of Georgia Coastal
Plain Stn., and the International Crops Research Institute for
the Semi-Arid Tropics (ICRISAT). It has moderate resistance
rust (caused by Puccinia arachidis Speg.) but lacks several ...
Registration of tifrust-13 peanut germplasm
TII~RUST3- pI eanut (Arachis hypogaeaL . ssp. hypogaeav ar. hypogaea)
was named and released as a germplasm line 7 Dec. 1981 by the
ARS, USDAt,h e Univ. of Georgia Coastal Plain Exp. Stn., the
International Crops Research Institute for the Semi-Arid Tropics,
and the Agricultural Res. Organization, Israel. The genotype
has resistance to peanut rust caused by Puccinia arachidis
Speg. in greenhouse and field tests conducted in Georgia, Puerto
Rico, and India. It has a larger seed and greater productivity
than most other sources of rust resistance
HDAC inhibitor confers radiosensitivity to prostate stem-like cells
Background: Radiotherapy can be an effective treatment for prostate cancer, but radiorecurrent tumours do develop. Considering prostate cancer heterogeneity, we hypothesised that primitive stem-like cells may constitute the radiation-resistant fraction.
Methods: Primary cultures were derived from patients undergoing resection for prostate cancer or benign prostatic hyperplasia. After short-term culture, three populations of cells were sorted, reflecting the prostate epithelial hierarchy, namely stem-like cells (SCs, α2β1integrinhi/CD133+), transit-amplifying (TA, α2β1integrinhi/CD133−) and committed basal (CB, α2β1integrinlo) cells. Radiosensitivity was measured by colony-forming efficiency (CFE) and DNA damage by comet assay and DNA damage foci quantification. Immunofluorescence and flow cytometry were used to measure heterochromatin. The HDAC (histone deacetylase) inhibitor Trichostatin A was used as a radiosensitiser.
Results: Stem-like cells had increased CFE post irradiation compared with the more differentiated cells (TA and CB). The SC population sustained fewer lethal double-strand breaks than either TA or CB cells, which correlated with SCs being less proliferative and having increased levels of heterochromatin. Finally, treatment with an HDAC inhibitor sensitised the SCs to radiation.
Interpretation: Prostate SCs are more radioresistant than more differentiated cell populations. We suggest that the primitive cells survive radiation therapy and that pre-treatment with HDAC inhibitors may sensitise this resistant fraction
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