Proc Natl Acad Sci U S A
December 2009
Increased female reproductive rates usually result in accelerated senescence. This correlation provides a link between the evolutionary conflict of the sexes and aging when ejaculate components elevate female reproductive rates at the cost of future reproduction. It is not clear whether this female cost is manifest as shorter lifespan or an earlier onset or a steeper rate of reproductive senescence.
View Article and Find Full Text PDFEcosystem stewardship is an action-oriented framework intended to foster the social-ecological sustainability of a rapidly changing planet. Recent developments identify three strategies that make optimal use of current understanding in an environment of inevitable uncertainty and abrupt change: reducing the magnitude of, and exposure and sensitivity to, known stresses; focusing on proactive policies that shape change; and avoiding or escaping unsustainable social-ecological traps. As we discuss here, all social-ecological systems are vulnerable to recent and projected changes but have sources of adaptive capacity and resilience that can sustain ecosystem services and human well-being through active ecosystem stewardship.
View Article and Find Full Text PDFAquaculture's pressure on forage fisheries remains hotly contested. This article reviews trends in fishmeal and fish oil use in industrial aquafeeds, showing reduced inclusion rates but greater total use associated with increased aquaculture production and demand for fish high in long-chain omega-3 oils. The ratio of wild fisheries inputs to farmed fish output has fallen to 0.
View Article and Find Full Text PDFPrevious studies have highlighted a role for the Notch signalling pathway during pronephrogenesis in the amphibian Xenopus laevis, and in nephron development in the mammalian metanephros, yet a mechanism for this function remains elusive. Here, we further the understanding of how Notch signalling patterns the early X. laevis pronephros anlagen, a function that might be conserved in mammalian nephron segmentation.
View Article and Find Full Text PDFThe rapid evolution of ejaculate components is considered to be largely driven by sexual selection. Less attention has been paid to the fact that sperm and microorganisms frequently meet; we consequently predict selection for substances that protect a male's ejaculate. We report, for the first time, bacteriolytic activity (lysozyme-like immune activity [LLA]) in the ejaculate of an animal, the common bedbug Cimex lectularius.
View Article and Find Full Text PDFObjectives: To assess timeliness of carotid endarterectomy services in the United Kingdom.
Design: Observational study with follow-up to March 2008.
Setting: UK hospitals performing carotid endarterectomy.
Background: The purpose of this study was to determine whether third-year medical students can become proficient in open technical skills through simulation laboratory training.
Methods: A total of 204 students participated in a structured curriculum including bladder catheterization, breast examination, and knot-tying. Proficiency was documented using global rating scales and validated, objective, model-based metrics.
Increasing clinical engagement is an NHS priority. Some medical staff have been reluctant to get involved in management. Giving clinicians more data about what their interventions are costing and how this compares with their peers could help get them more involved.
View Article and Find Full Text PDFBedbugs are a public health problem and can cause significant economic losses, but little is known about the effects of bites on humans. We reviewed case reports and published papers on bedbug bites to assess the empirical basis of the commonly cited figure that only approximately 80% of the population are sensitive to bedbug bites. We found the sensitivity estimate to be based on only one study carried out 80 years ago.
View Article and Find Full Text PDFHigher growing season temperatures can have dramatic impacts on agricultural productivity, farm incomes, and food security. We used observational data and output from 23 global climate models to show a high probability (>90%) that growing season temperatures in the tropics and subtropics by the end of the 21st century will exceed the most extreme seasonal temperatures recorded from 1900 to 2006. In temperate regions, the hottest seasons on record will represent the future norm in many locations.
View Article and Find Full Text PDFCurr Alzheimer Res
December 2008
Alzheimer's disease (AD) is the most common form of dementia in the elderly, and is characterized by the deposition of extracellular amyloid plaques primarily composed of the beta-amyloid peptide (Abeta). While these plaques define the pathology of AD, disease progression has been shown to correlate more closely with the level of synaptotoxicity induced by soluble Abeta oligomers. Recent evidence suggests that these oligomers are covalently crosslinked, possibly due to the interaction of Abeta with redox-active metal ions.
View Article and Find Full Text PDFBasic Clin Pharmacol Toxicol
August 2008
The effect of cannabinoids on motion-induced emesis is unknown. The present study investigated the action of phytocannabinoids against motion-induced emesis in Suncus murinus. Suncus murinus were injected intraperitoneally with either cannabidiol (CBD) (0.
View Article and Find Full Text PDFOptimal male and female mating rates rarely coincide. Males often shift the rate in their favor by either increased signaling and by overcoming female resistance to copulation. The concept of sensory exploitation posits that males produce signals that mimic naturally selected benefits and so deceitfully attract females.
View Article and Find Full Text PDFBackground: Endometriosis is considered a premalignant process whose association with carcinoma is well documented. We discuss a case of clear cell carcinoma with an unusual presentation in that it was located outside the abdominal cavity and was the only lesion noted clinically and radiologically. The histopathologic diagnostic criteria will be reviewed, as will the association of carcinomas with endometriosis.
View Article and Find Full Text PDFThe chemotherapeutic drug cisplatin is associated with severe gastrointestinal toxicity that can last for several days. A recent strategy to treat the nausea and emesis includes the combination of a 5-HT3 receptor antagonist, a glucocorticoid, and an NK1 receptor antagonist. The present studies explore the use of the selective noradrenaline reuptake inhibitors, (R)-sila-venlafaxine, (R,R)-reboxetine and (S,S)-reboxetine to prevent cisplatin (5 mg/kg, i.
View Article and Find Full Text PDFObjective: To determine whether variables in the surgery resident selection process will predict attrition or performance during residency training.
Design: Retrospective study.
Setting: A university residency program.
Qual Saf Health Care
April 2008
Background: In paediatric inpatients, medication errors occur as frequently as 1 in 4.2 drug orders, with up to 80% of these being prescribing errors.
Context: The children's unit of a district general hospital in West Yorkshire, UK.
This paper provides an original account of global land, water, and nitrogen use in support of industrialized livestock production and trade, with emphasis on two of the fastest-growing sectors, pork and poultry. Our analysis focuses on trade in feed and animal products, using a new model that calculates the amount of "virtual" nitrogen, water, and land used in production but not embedded in the product. We show how key meat-importing countries, such as Japan, benefit from "virtual" trade in land, water, and nitrogen, and how key meat-exporting countries, such as Brazil, provide these resources without accounting for their true environmental cost.
View Article and Find Full Text PDFInvestments aimed at improving agricultural adaptation to climate change inevitably favor some crops and regions over others. An analysis of climate risks for crops in 12 food-insecure regions was conducted to identify adaptation priorities, based on statistical crop models and climate projections for 2030 from 20 general circulation models. Results indicate South Asia and Southern Africa as two regions that, without sufficient adaptation measures, will likely suffer negative impacts on several crops that are important to large food-insecure human populations.
View Article and Find Full Text PDFJ Comp Physiol B
July 2008
The marsupial genus Antechinus is a group of small carnivorous marsupials from the order Dasyuromorphia (Family Dasyuridae) and is found in eastern Australia. The life history of all species in the genus is characterized by a complex, but highly synchronized life cycle in both sexes, culminating in a short mating period followed by total male mortality (semelparity). The breeding season is defined by a specific rate of increase in photoperiod, which is different for each species.
View Article and Find Full Text PDFAlzheimer's disease (AD) is the most common form of dementia and is associated with the deposition of the 39- to 43-amino acid beta-amyloid peptide (Abeta) in the brain. C-terminal fragments (CTFs) of amyloid precursor protein (APP) can accumulate in endosomally derived multivesicular bodies (MVBs). These intracellular structures contain intraluminal vesicles that are released from the cell as exosomes when the MVB fuses with the plasma membrane.
View Article and Find Full Text PDFSexual conflict can produce several evolutionary outcomes, one of which is female-limited trait polymorphism. We examine the African bat bug Afrocimex constrictus (Cimicidae), a species where both sexes are subjected to traumatic intromission from males. We show that males possess female genital structures that in related species ameliorate the costs of traumatic insemination.
View Article and Find Full Text PDFSigns of severe otitis media in 20% of dairy calves on one farm were associated with Mycoplasma bovis infection, based on isolation from the external ear canal and nares. Affected calves seroconverted to M. bovis and no other significant bacteria were isolated.
View Article and Find Full Text PDF