392 research outputs found
Diverse fossil epacrids (Styphelioideae; Ericaceae) from early Pleistocene sediments at Stony Creek Basin, Victoria, Australia
There is currently intense interest in the radiation of the scleromorphic groups that dominate the Australian flora, but at present, only Proteaceae and Casuarinaceae have fossil records detailed enough to provide useful evidence on the timing of these radiations. This article records a diverse assemblage of fossil leaves of another major scleromorphic group, the epacrids (subfamily Styphelioideae of Ericaceae, formerly known as Epacridaceae). The fossils are from Stony Creek Basin, in the western uplands of Victoria, Australia, and are of earliest Pleistocene age (ca. 1.6 million years old). They include 19 forms sufficiently distinct as to constitute different species. This diversity is considerably greater than the extant diversity of epacrids in the region. Published taphonomic data are used to argue that the actual diversity of the source vegetation of the fossil flora may have been significantly greater and comparable to the current local species richness of the centers of diversity. Ten of the fossil species are assigned to the largest extant tribe (Styphelieae), eight are assigned to Epacrideae or Archerieae, and one is assigned to Cosmelieae. This evidence is used to argue that substantial radiation of the epacrids had occurred by the beginning of the Pleistocene
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
The fate of porcine sperm CRISP2 from the perinuclear theca before and after in vitro fertilization
In a previous study, we reported that porcine sperm cysteine-rich secretory protein 2 (CRISP2) is localized in the post-acrosomal sheath-perinuclear theca (PT) as reduction-sensitive oligomers. In the current study, the decondensation and removal of CRISP2 was investigated during in vitro sperm capacitation, after both the induction of the acrosome reaction and in vitro fertilization. Confocal immunofluorescent imaging revealed that additional CRISP2 fluorescence appeared on the apical ridge and on the equatorial segment (EqS) of the sperm head following capacitation, likely due to cholesterol removal. After an ionophore A23187-induced acrosome reaction, CRISP2 immunofluorescence disappeared from the apical ridge and the EqS area partly not only owing to the removal of the acrosomal shroud vesicles, but to its presence in a subdomain of EqS. The fate of sperm head CRISP2 was further examined post-fertilization. In vitro matured porcine oocytes were co-incubated with boar sperm cells for 6-8 h and the zygotes were processed for CRISP2 immunofluorescent staining. Notably, decondensation of CRISP2, and thus of the sperm PT, occurred while the sperm nucleus was still fully condensed. CRISP2 was no longer detectable in fertilized oocytes in which sperm nuclear decondensation and paternal pronucleus formation were apparent. This rapid dispersal of CRISP2 in the PT is likely regulated by redox reactions for which its cysteine-rich domain is sensitive. Reduction of disulfide bridges within CRISP2 oligomers may be instrumental for PT dispersal and elimination
Ambulatory Blood Pressure Monitoring in Individuals with HIV: A Systematic Review and Meta-Analysis
Introduction
Abnormal diurnal blood pressure (BP) rhythms may contribute to the high cardiovascular disease risk in HIV-positive (HIV+) individuals. To synthesize the current literature on ambulatory BP monitoring (ABPM) in HIV+ individuals, a systematic literature review and meta-analysis were performed.
Methods
Medical databases were searched through November 11, 2015 for studies that reported ABPM results in HIV+ individuals. Data were extracted by 2 reviewers and pooled differences between HIV+ and HIV-negative (HIV-) individuals in clinic BP and ABPM measures were calculated using random-effects inverse variance weighted models.
Results
Of 597 abstracts reviewed, 8 studies with HIV+ cohorts met the inclusion criteria. The 420 HIV+ and 714 HIV- individuals in 7 studies with HIV- comparison groups were pooled for analyses. The pooled absolute nocturnal systolic and diastolic BP declines were 3.16% (95% confidence interval [CI]: 1.13%, 5.20%) and 2.92% (95% CI: 1.64%, 4.19%) less, respectively, in HIV+ versus HIV- individuals. The pooled odds ratio for non-dipping systolic BP (nocturnal systolic BP decline <10%) in HIV+ versus HIV- individuals was 2.72 (95% CI: 1.92, 3.85). Differences in mean clinic, 24-hour, daytime, or nighttime BP were not statistically significant. I2 and heterogeneity chi-squared statistics indicated the presence of high heterogeneity for all outcomes except percent DBP dipping and non-dipping SBP pattern.
Conclusions
An abnormal diurnal BP pattern may be more common among HIV+ versus HIV- individuals. However, results were heterogeneous for most BP measures, suggesting more research in this area is needed
A stallion spermatozoon's journey through the mare's genital tract: In vivo and in vitro aspects of sperm capacitation
Conventional in vitro fertilization is not efficacious when working with equine gametes. Although stallion spermatozoa bind to the zona pellucida in vitro, these gametes fail to initiate the acrosome reaction in the vicinity of the oocyte and cannot, therefore, penetrate into the perivitelline space. Failure of sperm penetration most likely relates to the absence of optimized in vitro fertilization media containing molecules essential to support stallion sperm capacitation. In vivo, the female reproductive tract, especially the oviductal lumen, provides an environmental milieu that appropriately regulates interactions between the gametes and promotes fertilization. Identifying these 'fertilization supporting factors' would be a great contribution for development of equine in vitro fertilization media. In this review, a description of the current understanding of the interactions stallion spermatozoa undergo during passage through the female genital tract, and related specific molecular changes that occur at the sperm plasma membrane is provided. Understanding these molecular changes may hold essential clues to achieving successful in vitro fertilization with equine gametes
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
Small calcified lesions suggestive of neurocysticercosis are associated with mesial temporal sclerosis
Use of prescription stimulant for Attention Deficit Hyperactivity Disorder in Aboriginal children and adolescents: a linked data cohort study
Preventing Violence in Seven Countries: Global Convergence in Policies
Do governments take the measures that are supported by the best scientific evidence available? We present a brief review of the situation in: Australia, Canada, Germany, the Netherlands, Spain, the United Kingdom, and the United States. Our findings show surprisingly similar developments across countries. While all seven countries are moving towards evidence-based decision making regarding policies and programs to prevent violence, there remain a number of difficulties before this end can be achieved. For example, there continue to be few randomized controlled trials or rigorous quasi-experimental studies on aggression and violence. Results from experimental research are essential to both policy makers and researchers to determine the effectiveness of programs as well as increase our knowledge of the problem. Additionally, all noted that media attention for violence is high in their country, often leading to management by crisis with the result that policies are not based on evidence, but instead seek to appease public outrage. And perhaps because of attendant organizational problems (i.e., in many countries violence prevention was not under the guise of one particular agency or ministry), most have not developed a coordinated policy focusing on the prevention of violence and physical aggression. It is hypothesized that leaders in democratic countries, who must run for election every 4 to 6 years, may feel a need to focus on short-term planning rather than long-term preventive policies since the costs, but not the benefits for the latter would be incurred while they still served in office. We also noted a general absence of expertise beyond those within scientific circles. The need for these ideas to be more widely accepted will be an essential ingredient to real and sustaining change. This means that there must be better communication and increased understanding between researchers and policy makers. Toward those ends, the recent establishment of the Campbell Collaboration, formed to provide international systematic reviews of program effectiveness, will make these results more available and accessible to politicians, administrators and those charged with making key policy decision
- …