Nutrient and fecal microbe sources for a eutrophic lake and recommended remediation steps, Wilgreen Lake, Madison County, Kentucky

Wilgreen Lake is a man-made lake, classified as nutrient-impaired (303d list) by the EPA and State of Kentucky. The lake drains a watershed with residential developments, cattle pasture, modified woodlands, and some industrial/urban usage in the city of Richmond. The principal tributaries are Taylor Fork and Old Town Branch that meet to form the trunk of the lake approximately one mile in length. The upper reaches of Taylor Fork are adjacent to a densely-packed (quarter-acre lots) housing development with septic systems, and its watershed drains some portions of southern Richmond. Old Town Branch drains cattle pasture and residential areas of moderate to large lot size. An intermittent tributary flowing into Pond Cove drains cattle pasture and one small housing development. Fecal material contributes both nutrients and microbes to Wilgreen Lake. Both cattle and human fecal material enter the lake as documented by high fecal microbes counts and DNA tracing techniques. DNA tracing methods are limited by our sampling frequency but show that bovine Bacteroides microbes dominate water samples even at loci where suspected septic effluent enters the lake. The nitrogen isotopic composition (d15N) of lake plankton and algae are broadly consistent with nitrogen input from human fecal material, but results are equivocal. We suspect that large amounts of nutrients do enter the lake through septic groundwater input, however, the strong bovine signal clearly suggests deployment of remediation methods that would limit runoff from pastures adjacent to Wilgreen Lake and within its watershed. Such methods include fencing cattle off from drainages and the lake, and planting vegetative buffers around stream and lake margins. Our data alone cannot justify elimination of septic systems by costly implementation of a sewage treatment system

Effect of Learning to Use a Mobility Aid on Gait and Cognitive Demands in People with Mild to Moderate Alzheimer\u27s Disease: Part I - Cane

BACKGROUND: People with Alzheimer\u27s disease (AD) exhibit balance and walking impairments that increase falls risk. Prescription of a mobility aid is done to improve stability, yet also requires increased cognitive resources. Single-point canes require unique motor sequencing for safe use. The effect of learning to use a single-point cane has not been evaluated in people with AD. OBJECTIVES: In people with AD and healthy adult controls: 1) examine changes in gait while using a cane under various walking conditions; and 2) determine the cognitive and gait costs associated with concurrent cane walking while multi-tasking. METHODS: Seventeen participants with AD (age 82.1±5.6 years) and 25 healthy controls (age 70.8±14.1 years) walked using a single-point cane in a straight (6 meter) and a complex (Figure of 8) path under three conditions: single-task (no aid), dual-task (walking with aid), and multi-task (walking with aid while counting backwards by ones). Velocity and stride time variability were recorded with accelerometers. RESULTS: Gait velocity significantly slowed for both groups in all conditions and stride time variability was greater in the AD group. Overall, multi-tasking produced a decrease in gait and cognitive demands for both groups, with more people with AD self-prioritizing the cognitive task over the gait task. CONCLUSION: Learning to use a cane demands cognitive resources that lead to detrimental changes in velocity and stride time variability. This was most pronounced in people with mild to moderate AD. Future research needs to investigate the effects of mobility aid training on gait performance

Accuracy of SIAscopy for pigmented skin lesions encountered in primary care: development and validation of a new diagnostic algorithm.

BACKGROUND: Diagnosing pigmented skin lesions in general practice is challenging. SIAscopy has been shown to increase diagnostic accuracy for melanoma in referred populations. We aimed to develop and validate a scoring system for SIAscopic diagnosis of pigmented lesions in primary care. METHODS: This study was conducted in two consecutive settings in the UK and Australia, and occurred in three stages: 1) Development of the primary care scoring algorithm (PCSA) on a sub-set of lesions from the UK sample; 2) Validation of the PCSA on a different sub-set of lesions from the same UK sample; 3) Validation of the PCSA on a new set of lesions from an Australian primary care population. Patients presenting with a pigmented lesion were recruited from 6 general practices in the UK and 2 primary care skin cancer clinics in Australia. The following data were obtained for each lesion: clinical history; SIAscan; digital photograph; and digital dermoscopy. SIAscans were interpreted by an expert and validated against histopathology where possible, or expert clinical review of all available data for each lesion. RESULTS: A total of 858 patients with 1,211 lesions were recruited. Most lesions were benign naevi (64.8%) or seborrhoeic keratoses (22.1%); 1.2% were melanoma. The original SIAscopic diagnostic algorithm did not perform well because of the higher prevalence of seborrhoeic keratoses and haemangiomas seen in primary care. A primary care scoring algorithm (PCSA) was developed to account for this. In the UK sample the PCSA had the following characteristics for the diagnosis of 'suspicious': sensitivity 0.50 (0.18-0.81); specificity 0.84 (0.78-0.88); PPV 0.09 (0.03-0.22); NPV 0.98 (0.95-0.99). In the Australian sample the PCSA had the following characteristics for the diagnosis of 'suspicious': sensitivity 0.44 (0.32-0.58); specificity 0.95 (0.93-0.97); PPV 0.52 (0.38-0.66); NPV 0.95 (0.92-0.96). In an analysis of lesions for which histological diagnosis was available (n = 111), the PCSA had a significantly greater Area Under the Curve than the 7-point checklist for the diagnosis of melanoma (0.83; 95% CI 0.71-0.95 versus 0.61; 95% CI 0.44-0.78; p = 0.02 for difference). CONCLUSIONS: The PCSA could have a useful role in improving primary care management of pigmented skin lesions. Further work is needed to develop and validate the PCSA in other primary care populations and to evaluate the cost-effectiveness of GP management of pigmented lesions using SIAscopy.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Effect of Learning to Use a Mobility Aid on Gait and Cognitive Demands in People with Mild to Moderate Alzheimer\u27s Disease: Part II - 4-Wheeled Walker.

BACKGROUND: Cognitive deficits and gait problems are common and progressive in Alzheimer\u27s disease (AD). Prescription of a 4-wheeled walker is a common intervention to improve stability and independence, yet can be associated with an increased falls risk. OBJECTIVES: 1) To examine changes in spatial-temporal gait parameters while using a 4-wheeled walker under different walking conditions, and 2) to determine the cognitive and gait task costs of walking with the aid in adults with AD and healthy older adults. METHODS: Twenty participants with AD (age 79.1±7.1 years) and 22 controls (age 68.5±10.7 years) walked using a 4-wheeled walker in a straight (6 m) and Figure of 8 path under three task conditions: single-task (no aid), dual-task (walking with aid), and multi-task (walking with aid while counting backwards by ones). RESULTS: Gait velocity was statistically slower in adults with AD than the controls across all conditions (all p values CONCLUSION: Learning to use a 4-wheeled walker is cognitively demanding and any additional tasks increases the demands, further adversely affecting gait. The increased cognitive demands result in a decrease in gait velocity that is greatest in adults with AD. Future research needs to investigate the effects of mobility aid training on gait performance

The experiences of people with Alzheimer’s dementia and their caregivers in acquiring and using a mobility aid_ a qualitative study

Purpose: Cognitive deficits and gait and balance problems are progressive in people with Alzheimer’s dementia. Yet, mobility aids are associated with an increased falls risk in people with dementia. Our objectives were to identify the perceptions of people living with mild-to-moderate Alzheimer’s dementia, and their caregivers, on the use of mobility aids. Methods: A qualitative study using semi-structured, face-to-face interviews was conducted. Community-dwelling older adults with dementia attending a day hospital program were recruited. Thematic analysis was conducted and the text was coded into broad themes aligned with the research questions. The coded text was examined for patterns and similarities, and grouped to form inductive themes. Results: Twenty-four people (12 living with dementia and their 12 caregivers) participated. Five themes were identified: (1) acknowledgement of need; (2) protecting a sense of self; (3) caregiver oversight and relief of burden; (4) healthcare professional involvement; (5) environment and design of aids. Conclusions: The findings suggest that people with Alzheimer’s dementia and their caregivers regard mobility aid use as increasing independence. There is a role for healthcare professionals to be involved in the prescription, provision and training for use of mobility aids among people living with dementia to ensure uptake and safety.IMPLICATIONS FOR REHABILITATION Mobility aid use is regarded as increasing independence by people with Alzheimer’s disease and their caregivers. Falls risk associated with mobility aid use was not well known and caregivers perceived mobility aids as a means to reduce falls. Most people do not see a healthcare professional when they acquire a mobility aid and there is a role for healthcare professionals to be involved in the prescription, provision and training of people living with dementia in the use of mobility aids in order to increase the uptake of aids and their safe use

High-resolution mass models of dwarf galaxies from LITTLE THINGS

We present high-resolution rotation curves and mass models of 26 dwarf galaxies from LITTLE THINGS. LITTLE THINGS is a high-resolution Very Large Array HI survey for nearby dwarf galaxies in the local volume within 11 Mpc. The rotation curves of the sample galaxies derived in a homogeneous and consistent manner are combined with Spitzer archival 3.6 micron and ancillary optical U, B, and V images to construct mass models of the galaxies. We decompose the rotation curves in terms of the dynamical contributions by baryons and dark matter halos, and compare the latter with those of dwarf galaxies from THINGS as well as Lambda CDM SPH simulations in which the effect of baryonic feedback processes is included. Being generally consistent with THINGS and simulated dwarf galaxies, most of the LITTLE THINGS sample galaxies show a linear increase of the rotation curve in their inner regions, which gives shallower logarithmic inner slopes alpha of their dark matter density profiles. The mean value of the slopes of the 26 LITTLE THINGS dwarf galaxies is alpha =-0.32 +/- 0.24 which is in accordance with the previous results found for low surface brightness galaxies (alpha = -0.2 +/- 0.2) as well as the seven THINGS dwarf galaxies (alpha =-0.29 +/- 0.07). However, this significantly deviates from the cusp-like dark matter distribution predicted by dark-matter-only Lambda CDM simulations. Instead our results are more in line with the shallower slopes found in the Lambda CDM SPH simulations of dwarf galaxies in which the effect of baryonic feedback processes is included. In addition, we discuss the central dark matter distribution of DDO 210 whose stellar mass is relatively low in our sample to examine the scenario of inefficient supernova feedback in low mass dwarf galaxies predicted from recent Lambda SPH simulations of dwarf galaxies where central cusps still remain.Peer reviewe

The M81 Group Dwarf Irregular Galaxy DDO 165. I. High Velocity Neutral Gas in a Post-Starburst System

We present new multi-configuration VLA HI spectral line observations of the M81 group dIrr post-starburst galaxy DDO 165. The HI morphology is complex, with multiple column density peaks surrounding a large region of very low HI surface density that is offset from the center of the stellar distribution. The bulk of the neutral gas is associated with the southern section of the galaxy; a secondary peak in the north contains ~15% of the total HI mass. These components appear to be kinematically distinct, suggesting that either tidal processes or large-scale blowout have recently shaped the ISM of DDO 165. Using spatially-resolved position-velocity maps, we find multiple localized high-velocity gas features. Cross-correlating with radius-velocity analyses, we identify eight shell/hole structures in the ISM with a range of sizes (~400-900 pc) and expansion velocities (~7-11 km/s). These structures are compared with narrow- and broad-band imaging from KPNO and HST. Using the latter data, recent works have shown that DDO 165's previous "burst" phase was extended temporally (>1 Gyr). We thus interpret the high-velocity gas features, HI holes, and kinematically distinct components of the galaxy in the context of the immediate effects of "feedback" from recent star formation. In addition to creating HI holes and shells, extended star formation events are capable of creating localized high velocity motion of the surrounding interstellar material. A companion paper connects the energetics from the HI and HST data.Comment: The Astrophysical Journal, in press. Full-resolution version available on request from the first autho

The VLT-FLAMES survey of massive stars: constraints on stellar evolution from the chemical compositions of rapidly rotating Galactic and Magellanic Cloud B-type stars

We have previously analysed the spectra of 135 early B-type stars in the LMC and found several groups of stars that have chemical compositions that conflict with the theory of rotational mixing. Here we extend this study to Galactic and SMC metallicities with the analysis of ~50 Galactic and ~100 SMC early B-type stars with rotational velocities up to ~300km/s. The surface nitrogen abundances are utilised as a probe of the mixing process. In the SMC, we find a population of slowly rotating nitrogen-rich stars amongst the early B type core-hydrogen burning stars, similar to the LMC. In the Galactic sample we find no significant enrichment amongst the core hydrogen-burning stars, which appears to be in contrast with the expectation from both rotating single-star and close binary evolution models. However, only a small number of the rapidly rotating stars have evolved enough to produce a significant nitrogen enrichment, and these may be analogous to the non-enriched rapid rotators previously found in the LMC sample. Finally, in each metallicity regime, a population of highly enriched supergiants is observed, which cannot be the immediate descendants of core-hydrogen burning stars. Their abundances are, however, compatible with them having gone through a previous red supergiant phase. Together, these observations paint a complex picture of the nitrogen enrichment in massive main sequence and supergiant stellar atmospheres, where age and binarity cause crucial effects. Whether rotational mixing is required to understand our results remains an open question at this time, but could be answered by identifying the true binary fraction in those groups of stars that do not agree with single-star evolutionary models (abridged).Comment: Accepted paper - 86 pages with tables and figure

Assessing the Impact of the Small Farmer-Tuskegee University-Walmart Project on the Household Economy of Small and Limited Resource Farmers in Alabama

Abstract This study focused on the impact of the Small Farmer-Tuskegee University-Walmart Project, an agribusiness opportunity for small and limited resource farmers in rural Alabama. The Project provided a package of programs that strengthened the farmers’ entrepreneurial capacity and secured a market with Walmart for contracted produce. The study applied the triangulation approach to collect field data, and conducted a case study using quantitative and qualitative tools to measure socioeconomic and environmental impacts. The results revealed that the target group benefitted enormously, as desired variables, namely, family income; technical knowledge; agribusiness entrepreneurial skill; leadership quality; factor productivity; direct, indirect, and induced impacts; and employment in the community, changed positively. Keywords: Entrepreneurship, Household Economy, Small and Limited Resource Farmers, Walmart Initiativ