35 research outputs found
Global patterns of extinction risk and conservation needs for Rodentia and Eulipotyphla
AIM: To explore global patterns in spatial aggregations of species richness, vulnerability and data deficiency for Rodentia and Eulipotyphla. To evaluate the adequacy of existing protected area (PA) network for these areas. To provide a focus for local conservation initiatives. LOCATION: Global. METHODS: Total species, globally threatened (GT) species, and Data Deficient (DD) species richness were calculated for a 1° resolution grid. Correspondence analyses between global species richness against GT species richness were performed. To assess PA network adequacy, a correspondence analysis was conducted to identify areas of high richness and GT species richness that have poor protection. RESULTS: Six hotspots were identified for GT eulipotyphlans, encompassing 40% of GT species. Three of these contain higher numbers of GT species than would be expected based on their overall species richness. Ten priority regions were identified for GT rodents, which together contain 34% of all GT species. Six contain higher numbers of GT rodent species than would be expected based on their overall species richness. For DD species, 15% of DD eulipotyphlans were represented within three priority regions, whereas 18 were identified for rodents, capturing 53% of all DD species. Areas containing lower numbers of protected GT eulipotyphlan species than expected include Mexico; Cameroonian Highlands; Albertine Rift; Tanzania; Kenya; Ethiopia; western Asia; India; and Sri Lanka. Areas containing lower numbers of protected GT rodent species than expected are Borneo, Sumatra and Sulawesi. Five eulipotyphlans and 44 rodents have ranges which fall completely outside of PAs. MAIN CONCLUSION: Rodentia and Eulipotyphla priority regions should be considered separately to one another and to other mammals. This analysis approach allows us to pinpoint and delineate geographical areas which represent key regions at a global level for rodents and eulipotyphlans, in order to facilitate conservation, field research and capacity building at a local level
Epigenetic regulation of caloric restriction in aging
The molecular mechanisms of aging are the subject of much research and have facilitated potential interventions to delay aging and aging-related degenerative diseases in humans. The aging process is frequently affected by environmental factors, and caloric restriction is by far the most effective and established environmental manipulation for extending lifespan in various animal models. However, the precise mechanisms by which caloric restriction affects lifespan are still not clear. Epigenetic mechanisms have recently been recognized as major contributors to nutrition-related longevity and aging control. Two primary epigenetic codes, DNA methylation and histone modification, are believed to dynamically influence chromatin structure, resulting in expression changes of relevant genes. In this review, we assess the current advances in epigenetic regulation in response to caloric restriction and how this affects cellular senescence, aging and potential extension of a healthy lifespan in humans. Enhanced understanding of the important role of epigenetics in the control of the aging process through caloric restriction may lead to clinical advances in the prevention and therapy of human aging-associated diseases
Impact of caloric and dietary restriction regimens on markers of health and longevity in humans and animals: a summary of available findings
Considerable interest has been shown in the ability of caloric restriction (CR) to improve multiple parameters of health and to extend lifespan. CR is the reduction of caloric intake - typically by 20 - 40% of ad libitum consumption - while maintaining adequate nutrient intake. Several alternatives to CR exist. CR combined with exercise (CE) consists of both decreased caloric intake and increased caloric expenditure. Alternate-day fasting (ADF) consists of two interchanging days; one day, subjects may consume food ad libitum (sometimes equaling twice the normal intake); on the other day, food is reduced or withheld altogether. Dietary restriction (DR) - restriction of one or more components of intake (typically macronutrients) with minimal to no reduction in total caloric intake - is another alternative to CR. Many religions incorporate one or more forms of food restriction. The following religious fasting periods are featured in this review: 1) Islamic Ramadan; 2) the three principal fasting periods of Greek Orthodox Christianity (Nativity, Lent, and the Assumption); and 3) the Biblical-based Daniel Fast. This review provides a summary of the current state of knowledge related to CR and DR. A specific section is provided that illustrates related work pertaining to religious forms of food restriction. Where available, studies involving both humans and animals are presented. The review includes suggestions for future research pertaining to the topics of discussion