37 research outputs found

    A New Horned Crocodile from the Plio-Pleistocene Hominid Sites at Olduvai Gorge, Tanzania

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    BACKGROUND: The fossil record reveals surprising crocodile diversity in the Neogene of Africa, but relationships with their living relatives and the biogeographic origins of the modern African crocodylian fauna are poorly understood. A Plio-Pleistocene crocodile from Olduvai Gorge, Tanzania, represents a new extinct species and shows that high crocodylian diversity in Africa persisted after the Miocene. It had prominent triangular "horns" over the ears and a relatively deep snout, these resemble those of the recently extinct Malagasy crocodile Voay robustus, but the new species lacks features found among osteolaemines and shares derived similarities with living species of Crocodylus. METHODOLOGY/PRINCIPAL FINDINGS: The holotype consists of a partial skull and skeleton and was collected on the surface between two tuffs dated to approximately 1.84 million years (Ma), in the same interval near the type localities for the hominids Homo habilis and Australopithecus boisei. It was compared with previously-collected material from Olduvai Gorge referable to the same species. Phylogenetic analysis places the new form within or adjacent to crown Crocodylus. CONCLUSIONS/SIGNIFICANCE: The new crocodile species was the largest predator encountered by our ancestors at Olduvai Gorge, as indicated by hominid specimens preserving crocodile bite marks from these sites. The new species also reinforces the emerging view of high crocodylian diversity throughout the Neogene, and it represents one of the few extinct species referable to crown genus Crocodylus

    Human total, basal and activity energy expenditures are independent of ambient environmental temperature

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    Lower ambient temperature (Ta) requires greater energy expenditure to sustain body temperature. However, effects of Ta on human energetics may be buffered by environmental modification and behavioral compensation. We used the IAEA DLW database for adults in the USA (n = 3213) to determine the effect of Ta (−10 to +30°C) on TEE, basal (BEE) and activity energy expenditure (AEE) and physical activity level (PAL). There were no significant relationships (p > 0.05) between maximum, minimum and average Ta and TEE, BEE, AEE and PAL. After adjustment for fat-free mass, fat mass and age, statistically significant (p < 0.01) relationships between TEE, BEE and Ta emerged in females but the effect sizes were not biologically meaningful. Temperatures inside buildings are regulated at 18–25°C independent of latitude. Hence, adults in the US modify their environments to keep TEE constant across a wide range of external ambient temperatures

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

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    In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

    IV Alcohol in Prevention of Delirium Tremens

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    Occupational therapy for children with cerebral palsy.

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    Objectives: The object of our systematic review, therefore, was to determine whether OT interventions improve functional abilities and social participation in children with cerebral palsy. Criteria for considering Studies for this Review: Types of studies: Studies with one of the following designs will be entered in the review. 1) Randomised controlled clinical trial (RCT): An experiment in which investigators randomly allocate eligible people into treatment and control groups. Cross-over trials will be considered as RCTs according to the Cochrane Collaboration Guidelines (Clarke 2000). 2) Controlled clinical trial (CCT): an experiment in which eligible people are in a non-randomized way allocated to the treatment and the control groups 3) Other than controlled designs (OD): patient series and pre-post studies. Such ODs can only contribute in a limited way to the best evidence synthesis. Types of participants: Studies with children/ adolescents aged <20 years with a clinical diagnosis of cerebral palsy will be included. Types of intervention: Occupational therapy interventions will be regarded as "comprehensive OT" (when all five intervention categories are part of the evaluated OT treatment) or will be classified into five specific intervention categories: 1) training of sensory-motor functions; 2) training of skills; 3) parental counselling; 4) advice or instruction regarding the use of assistive devices; and 5) provision of splints. All studies with above specified interventions according to a group of four experienced occupational therapists and reviewer CHME (see Methods of the review) are eligible for inclusion in this review. Types of outcome measures: Primary outcome measures: Functional ability and/or social participation. Secondary outcome measures: Motor-function (either balance or arm-hand function) and/or muscle tone
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