4,082 research outputs found
EFFECT OF RECREATIONAL TRAIL TRAFFIC LEVEL ON EASTERN RED-BACKED SALAMANDER (PLETHODON CINEREUS) RELATIVE ABUNDANCE
The effects of roads and trails on terrestrial salamanders, primarily plethodontids, can be important. The abundance of terrestrial salamanders often increases with distance from roads. Less is known about the effects of recreational or hiking trails on terrestrial salamanders than is known about the effects of roads. We explored how low and high traffic trails in a suburban biological reserve affect the relative abundance of Eastern Red-backed Salamanders (Plethodon cinereus). We found more salamanders under cover objects next to low traffic trails compared to either high traffic trails or wooded areas without trails. At wooded sites, we found only striped morphs whereas at high traffic sites we found only unstriped morphs. Low traffic sites included a range of color morph frequencies. The proportion of females found in each site did not differ, nor did the mean size of the salamanders. Our results suggest that the impact of recreational walking trails needs to be examined more closely to see how and why the distributions of P. cinereus, and potentially other woodland salamanders, are affected and what trail characteristics are important in driving the apparent effects. Such information will contribute to the design and maintenance of walking trails in natural areas that minimize effects on terrestrial salamanders, and likely other organisms
Effects of age and group size on habitat selection and activity level in Xenopus laevis tadpoles
Effects of Age and Group Size on Habitat Selection and Activity Level in \u3ci\u3eXenopus Laevis\u3c/i\u3e Tadpoles
We experimentally examined the effects of age and group size on habitat selection and activity level in Xenopus laevis tadpoles. Tadpoles were introduced into an experimental arena at two ages (early and late) and at three group sizes (one, two, and six tadpoles). Group size did not affect habitat selection or activity level. Late tadpoles were more active and used the bottom of the arena more than early tadpoles. Our results suggest that an intrinsic cue (age) is important in determining the behavior of these tadpoles
Subadult Growth Stunting at Schroeder Mounds (11He177): A Late Woodland Sample from Illinois
Constitutional growth delay in subadults may be caused by chronic illness, malnutrition, and/or undernutrition. Very little is known about the community health of the presumptive forager-farmers of the Late Woodland (~ AD 900-1150) period site of Schroeder Mounds (Henderson County, Illinois). In an effort to increase understanding of community health, the subadults (N=15) were examined by age-at-death for evidence of growth stunting as reflected in forelimb shortening. Crural and brachial indices were calculated for those subadults preserving measurable femora and tibiae and/or measurable humeri and radii. These indices were compared by age category to indices calculated from normal bone lengths taken from published clinical data. Stunting was evident for all ages-at-death in the Schroeder Mounds sample. The stunting was contextualized by assessing the presence/absence of potentially causative or synergistically related skeletally visible chronic health stress indicators (i.e., porotic hyperostosis, cribra orbitalia, linear enamel hypoplasia, periostosis). The results indicated that all subadults exhibited growth stunting regardless of the presence of the quantified health issues. This may suggest that stunting is potentially a free-standing osteological marker of developmental stress. Within Schroeder Mounds, stunting may ultimately be due to various environmental (e.g., harvest or resource shortfall) and cultural (e.g., weaning, child labor) factors
A cohort study of the recovery of health and wellbeing following colorectal cancer (CREW study): protocol paper
Background: the number of people surviving colorectal cancer has doubled in recent years. While much of the literature suggests that most people return to near pre-diagnosis status following surgery for colorectal cancer, this literature has largely focused on physical side effects. Longitudinal studies in colorectal cancer have either been small scale or taken a narrow focus on recovery after surgery. There is a need for a comprehensive, long-term study exploring all aspects of health and wellbeing in colorectal cancer patients. The aim of this study is to establish the natural history of health and wellbeing in people who have been treated for colorectal cancer. People have different dispositions, supports and resources, likely resulting in individual differences in restoration of health and wellbeing. The protocol described in this paper is of a study which will identify who is most at risk of problems, assess how quickly people return to a state of subjective health and wellbeing, and will measure factors which influence the course of recovery. Methods: this is a prospective, longitudinal cohort study following 1000 people with colorectal cancer over a period of two years, recruiting from 30 NHS cancer treatment centres across the UK. Questionnaires will be administered prior to surgery, and 3, 9, 15 and 24 months after surgery, with the potential to return to this cohort to explore on-going issues related to recovery after cancer. Discussion: outcomes will help inform health care providers about what helps or hinders rapid and effective recovery from cancer, and identify areas for intervention development to aid this process. Once established the cohort can be followed up for longer periods and be approached to participate in related projects as appropriate and subject to funding<br/
Evaluation of the rate of artificial coverboard use by the salamander, Plethodon cinereus, in the vicinity of natural cover objects
- âŚ