The ecology and mechanisms of overflow‐mediated dispersal in a rock‐pool metacommunity

相似文献   

The role of the pod in seed development: strategies for manipulating yield

Pods play a key role in encapsulating the developing seeds and protecting them from pests and pathogens. In addition to this protective function, it has been shown that the photosynthetically active pod wall contributes assimilates and nutrients to fuel seed growth. Recent work has revealed that signals originating from the pod may also act to coordinate grain filling and regulate the reallocation of reserves from damaged seeds to those that have retained viability. In this review we consider the evidence that pods can regulate seed growth and maturation, particularly in members of the Brassicaceae family, and explore how the timing and duration of pod development might be manipulated to enhance either the quantity of crop yield or its nutritional properties.     

Worldwide host plants of the highly polyphagous, invasive Epiphyas postvittana (Lepidoptera: Tortricidae)

The light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), is a highly successful biological invader. It was accidentally introduced to several countries including New Zealand, Hawaii, England, and California. Light brown apple moth attacks a wide range of crop plants and other woody and herbaceous plants, but a more comprehensive analysis of its host range is needed for risk assessments, to evaluate the likely economic and environmental impacts, and to enable targeting of particular plant species for detection surveys and treatments. We reviewed and synthesized the host range and host selection behavior of light brown apple moth by using information from Australia and invaded countries. The host range of light brown apple moth is determined by the behavior of both adult females and larvae. Females use visual, chemical and physical cues to choose host plants. Larvae are capable of limited active dispersal by walking and longer range dispersal by ballooning on silken strands; therefore, larvae also may need to select host plants. We review larval performance indicators across a range of plants. Based on our review, there are at least 545 plant species in 363 genera from 121 families that have been reported as hosts of light brown apple moth. Some plants were reported only once and need verification. Nevertheless, many host plant species and their wide phylogenetic range (from ferns to higher dicotyledons) indicates that light brown apple moth is one of the most polyphagous insects known. This information and our categorization of frequency of host use are valuable for incursion response and pest management activities.     

Monitoring Progress towards Universal Health Coverage at Country and Global Levels

Universal health coverage (UHC) has been defined as the desired outcome of health system performance whereby all people who need health services (promotion, prevention, treatment, rehabilitation, and palliation) receive them, without undue financial hardship. UHC has two interrelated components: the full spectrum of good-quality, essential health services according to need, and protection from financial hardship, including possible impoverishment, due to out-of-pocket payments for health services. Both components should benefit the entire population.This paper summarizes the findings from 13 country case studies and five technical reviews, which were conducted as part of the development of a global framework for monitoring progress towards UHC.The case studies show the relevance and feasibility of focusing UHC monitoring on two discrete components of health system performance: levels of coverage with health services and financial protection, with a focus on equity. These components link directly to the definition of UHC and measure the direct results of strategies and policies for UHC. The studies also show how UHC monitoring can be fully embedded in often existing, regular overall monitoring of health sector progress and performance. Several methodological and practical issues related to the monitoring of coverage of essential health services, financial protection, and equity, are highlighted. Addressing the gaps in the availability and quality of data required for monitoring progress towards UHC is critical in most countries.

Summary Points

• The overall goal of universal health coverage (UHC) is that all people obtain the good-quality essential health services, including promotion, prevention, treatment, rehabilitation, and palliation, that they need without enduring financial hardship.
• A global UHC monitoring framework, developed by WHO and the World Bank Group in interaction with the process that led to this PLOS Collection, was used in 13 country case studies, underpinned by five technical reviews.
• The UHC monitoring framework focuses on the simultaneous monitoring of coverage of the population with essential health services and with financial protection against catastrophic out-of-pocket health payments, stratified by wealth quintile, place of residence, and sex.
• Most countries focus on regular monitoring of a set of tracer indicators for priority health services, as well as the occurrence of financial hardship and impoverishment due to out-of-pocket health expenses. The indicators generally follow international standards of measurement and can be used for global comparisons.
• Most countries do not have an explicit framework for UHC monitoring. The monitoring of UHC is, however, partially embedded in regular overall health sector progress and performance reviews which include health system inputs, service delivery, and health status indicators.
• There are major gaps in the availability and quality of data required for monitoring progress towards UHC. Countries mostly rely on international survey programs or national surveys to obtain disaggregated data on coverage and financial protection indicators, complemented by health facility data, but often the frequency and contents of these surveys are not sufficient to meet the country''s information needs.
• Monitoring progress towards the two components of UHC will be complementary and critical to achieving desirable health outcome goals, such as ending preventable deaths and promoting healthy life expectancy, and also reducing poverty and protecting household incomes.

     

24-Hour profiles of circulating ghrelin and peptide YY are inversely associated in normal weight premenopausal women

Peptide YY (PYY) and ghrelin (GHR) may modulate one another's actions within the hypothalamus. Peripheral infusion of PYY in humans acutely suppresses circulating concentrations of GHR. Whether an association between PYY and GHR exists in the peripheral circulation of humans over 24 h is unknown. The purpose of this study was to determine if circulating concentrations of PYY and GHR were significantly associated over 24 h in humans. Participants (n = 13) were normal weight, moderately active, women ages 18–24 yr. Blood samples were obtained q10 min for 24 h and assayed using RIA for total PYY and total GHR hourly from 0800 to 1000 h and 2000 to 0800 h and q20 min from 1000 to 2000 h. Dietary intake during the 24 h procedure was comprised of 55% carbohydrates, 30% fat, and 15% protein (three meals and a snack). Statistical analyses included linear mixed-effects modeling to test whether PYY predicted GHR concentrations over 24 h. Participants weighed 57.0 ± 1.5 kg and had 26.1 ± 1.5% body fat (15.0 ± 1.1 kg), 42.1 ± 1.1 kg fat free mass, a BMI of 21.3 ± 0.5 kg/m² and RMR of 1072 ± 28 kcal/24 h. Visually, PYY and GHR exhibited an inverse association over nearly the entire 24 h period. Statistically, circulating concentrations of 24 h PYY predicted 24 h GHR (ghrelin = 1860.51–2.14*PYY; p = 0.04). Circulating concentrations of PYY are inversely associated with GHR over 24 h. These data provide evidence that PYY may contribute to the modulation of the secretion of GHR in normal weight, premenopausal women over a 24 h period and supports similar inferences from experimental studies in animals and humans.     

Localization of the gene encoding the GABAA receptor β3 subunit to the Angelman/Prader-Willi region of human chromosome 15

Deletions of the proximal long arm of chromosome 15 (bands 15q11q13) are found in the majority of patients with two distinct genetic disorders, Angelman syndrome (AS) and Prader-Willi syndrome (PWS). The deleted regions in the two syndromes, defined cytogenetically and by using cloned DNA probes, are similar. However, deletions in AS occur on the maternally inherited chromosome 15, and deletions in PWS occur on the paternally derived chromosome 15. This observation has led to the suggestion that one or more genes in this region show differential expression dependent on parental origin (genetic imprinting). No genes of known function have previously been mapped to this region. We show here that the gene encoding the GABAA (gamma-aminobutyric acid) receptor beta 3 subunit maps to the AS/PWS region. Deletion of this gene (GABRB3) was found in AS and PWS patients with interstitial cytogenetic deletions. Evidence of beta 3 gene deletion was also found in an AS patient with an unbalanced 13;15 translocation but not in a PWS patient with an unbalanced 9;15 translocation. The localization of this receptor gene to the AS/PWS region suggests a possible role of the inhibitory neurotransmitter GABA in the pathogenesis of one or both of these syndromes.     

An invisible ubiquitin conformation is required for efficient phosphorylation by PINK1

The Ser/Thr protein kinase PINK1 phosphorylates the well‐folded, globular protein ubiquitin (Ub) at a relatively protected site, Ser65. We previously showed that Ser65 phosphorylation results in a conformational change in which Ub adopts a dynamic equilibrium between the known, common Ub conformation and a distinct, second conformation wherein the last β‐strand is retracted to extend the Ser65 loop and shorten the C‐terminal tail. We show using chemical exchange saturation transfer (CEST) nuclear magnetic resonance experiments that a similar, C‐terminally retracted (Ub‐CR) conformation also exists at low population in wild‐type Ub. Point mutations in the moving β5 and neighbouring β‐strands shift the Ub/Ub‐CR equilibrium. This enabled functional studies of the two states, and we show that while the Ub‐CR conformation is defective for conjugation, it demonstrates improved binding to PINK1 through its extended Ser65 loop, and is a superior PINK1 substrate. Together our data suggest that PINK1 utilises a lowly populated yet more suitable Ub‐CR conformation of Ub for efficient phosphorylation. Our findings could be relevant for many kinases that phosphorylate residues in folded protein domains.     

The kinetics of intrinsic factor-vitamin B12 binding

The kinetic behaviour of intrinsic factor-vitamin B₁₂ binding has been examined under varying conditions using an albuminised charcoal separation technique. The overall reaction obeys second order rate laws. The intrinsic factor considered alone obeys first order laws; the velocity of reaction of vitamin B₁₂ is too fast for measurement by the technique described but by deduction obeys first order laws. Rate constants as three temperatures, (k₂ at 25°C=1.56·10⁸·mole^?1·s^?1) the activation energy (E=12.7 kJ·mole^?1) and Arrhenius constant (A=2.7·10¹⁰ 1·mole^?1·s^?1 have been calculated. There is the possibility of diffusion control of the reaction in which case the E and A values are invalid. The effect of pH on the reaction has been studied and the results discussed in relation to the pH studies of other workers whose results show disagreement. Albumin coated charcoal was shown to discriminate between intrinsic factor-vitamin B₁₂ and free vitamn B₁₂ over a wide pH range. The apparent under-estimation of intrinsic factor in dilute solution was shown to be due to adsorption of the intrinsic factor to plastic tubes.     

Using clinicopathological analysis of general practitioner skin surgery to determine educational requirements and guidelines.

OBJECTIVE--To study the impact of skin surgery in general practice on the workload of a pathology laboratory and to identify what further training might be helpful. DESIGN--Analysis of skin biopsy specimens from general practitioners before and after their new contract to determine numbers of specimens, changes in diagnoses, adequacy of treatment of malignant tumours, and areas of low diagnostic accuracy. SETTING--District general hospital. SUBJECTS--All 1017 skin biopsy specimens from general practice for 15 months before and 12 months after the new general practitioner contract. RESULTS--The number of pathology specimens received increased from 16 to 65 per month (median = 6 submitted by each general practitioner in the post-contract year). The proportion of the more common pathological diagnoses was unchanged between the two periods, but the proportion of correctly diagnosed naevi, cysts, and seborrhoeic keratoses increased in the second. Although few diagnoses were overtly incorrect, accurate diagnosis of dermatofibromas and malignancies decreased after the contract, and the overall correct diagnosis rate for seborrhoeic keratoses, dermatofibromas, rashes, and malignancies was below 30%. Only nine out of 21 squamous cell carcinomas were adequately excised with tumour free margins, and follow up of malignant tumours may have been inadequate. CONCLUSIONS--Skin surgery in general practice has advantages but matters of concern are the increase in laboratory workload, the excision of some benign lesions, and the inappropriateness of biopsy of rashes. Squamous cell carcinoma and other malignant tumours submitted for pathological examination were often unsuspected and inadequately excised, and heightened suspicion is recommended. Pathology request forms may need redesigning to encourage provision of clinical details.     

Ivermectin is a specific inhibitor of importin α/β-mediated nuclear import able to inhibit replication of HIV-1 and dengue virus

The movement of proteins between the cytoplasm and nucleus mediated by the importin superfamily of proteins is essential to many cellular processes, including differentiation and development, and is critical to disease states such as viral disease and oncogenesis. We recently developed a high-throughput screen to identify specific and general inhibitors of protein nuclear import, from which ivermectin was identified as a potential inhibitor of importin α/β-mediated transport. In the present study, we characterized in detail the nuclear transport inhibitory properties of ivermectin, demonstrating that it is a broad-spectrum inhibitor of importin α/β nuclear import, with no effect on a range of other nuclear import pathways, including that mediated by importin β1 alone. Importantly, we establish for the first time that ivermectin has potent antiviral activity towards both HIV-1 and dengue virus, both of which are strongly reliant on importin α/β nuclear import, with respect to the HIV-1 integrase and NS5 (non-structural protein 5) polymerase proteins respectively. Ivermectin would appear to be an invaluable tool for the study of protein nuclear import, as well as the basis for future development of antiviral agents.