3,363 research outputs found
A Tale of Two Sylamores: Understanding Relationships Among Land Use, Nutrients, and Aquatic Communities Across a Subsidy-Stress Gradient
Agricultural land use is known to degrade aquatic systems with high inputs of nutrients, sediments, and pesticides. Increased nutrients can lead to increased algal growth and thus possible hypoxic conditions in slow moving water, while increased sediment loads have been shown to obstruct light and reduce substrate stability. These conditions negatively impact primary producers, macroinvertebrates, and fish. However, small-scale changes in land use can subsidize an aquatic ecosystem instead, where an increase in nutrients allows nutrient-limited biota to flourish, and minor increases in sedimentation may help support populations of collector-filterers. The stimulation in performance caused by small disturbances is part of the subsidy-stress gradient, where increasing perturbation subsidizes an ecosystem until a certain threshold is reached, at which a decline in performance and increased variability starts to occur. The North and South Sylamore watersheds in north Arkansas provide a useful template to investigate the subsidy-stress gradient in relation to land use. North Sylamore flows through the Ozark National Forest and has a heavily forested catchment, while South Sylamore flows through mostly private land, some of which is pasture (23%). Physicochemical, macroinvertebrate, and fish data were collected from multiple sites within each watershed to determine if South Sylamore is exhibiting a response to pasture/agriculture characteristic of a subsidy-stress gradient. Sites within South Sylamore had significantly higher nitrate levels, larger macroinvertebrate populations dominated by collector-filterers, and greater abundance of algivorous fish, suggesting South Sylamore may be subsidized by the surrounding pastoral lands. However, South Sylamore also had a significantly lower proportional abundance of sensitive macroinvertebrate taxa and more unique tolerant fish taxa, suggesting South Sylamore is experiencing stress as well. Habitat quality of South Sylamore could be improved by restoration of trees within the riparian zone. Monitoring aquatic systems for subsidy-stress responses can inform restoration/management decisions and guide intervention prior to watersheds and aquatic communities becoming overly stressed
Substantial Red Wolf Genetic Ancestry Persists in Wild Canids of Southwestern Louisiana
Concerns over red wolf (Canis rufus) extinction caused by hybridization with coyotes (C. latrans) led to the capture and removal of remnant wild wolves from southwestern Louisiana and southeastern Texas, United States, during the 1970s. Here we show that despite decades of unmitigated hybridization, and declaration of endangered red wolves as functionally extinct in the wild, red wolf mitochondrial or nuclear DNA ancestry persists in ∼55% of contemporary wild canids sampled in southwestern Louisiana. Surprisingly, one individual had 78–100% red wolf ancestry, which is within the range for 75% red wolf, red wolf backcross, or putative red wolf, depending on estimation method. Our findings bolster support for designation of red wolves as a distinct species, demonstrate a critical need for the United States Government to consider adopting an existing but unimplemented hybrid policy, and suggest that immediate reassessment of canid management and taxonomic designation in southwestern Louisiana may be warranted
Anthropogenically forced change in aquatic ecosystems: Reflections on the use of monitoring, archival and palaeolimnological data to inform conservation
The open collection “Aquatic transitions: Tracking the nature and trajectories of anthropogenically forced change in freshwater and coastal ecosystems” stems from a session of the same name at the ASLO (Association for the Sciences of Limnology and Oceanography) Aquatic Sciences Meeting 2017 in Honolulu, Hawai'i. The five papers gathered here reflect the focus of the special session on long-term ecosystem research and monitoring (LTERM), and collectively make use of monitoring data, palaeolimnology, and historical and documentary records to explore the timing, extent, and causes of human-related impacts on aquatic ecosystems. Collectively, they demonstrate that because timescales of ecological change often extend beyond contemporary monitoring, LTERM plays a crucial role in supporting evidence-based conservation. In this introduction, we reflect on the role that LTERM has had in each of the ecosystems studied, and discuss the opportunities for LTERM work to inform future conservation
Teaching Trauma Theory and Practice in Counselor Education: A Multiple Case Study
Teaching about trauma theory and practice is an integral part of counselor preparation. The purpose of this multiple case study was to understand how counselor educators (CEs) designed and facilitated significant learning experiences regarding trauma theory and practice. The researchers aimed to answer two research questions (1.) how do CEs choose which content to address in trauma courses and (2.) which teaching methods do CEs use to facilitate significant learning experiences in trauma courses? The study participants were three CEs teaching trauma courses in multiple formats (face-to-face, online, and hybrid) in CACREP programs. The results indicated that instructors faced unique situational factors that impacted their choice of teaching and learning activities and assessment measures. The themes Instructor Role, Instructor Identity, and Eliciting Fundamental Change in Learners impacted which teaching methods were chosen to facilitate significant learning experiences. The manuscript includes implications for CEs designing and teaching trauma courses
Evaluating Otter Reintroduction Outcomes Using Genetic Spatial Capture-Recapture Modified for Dendritic Networks
Monitoring the demographics and genetics of reintroduced populations is critical to evaluating reintroduction success, but species ecology and the landscapes that they inhabit often present challenges for accurate assessments. If suitable habitats are restricted to hierarchical dendritic networks, such as river systems, animal movements are typically constrained and may violate assumptions of methods commonly used to estimate demographic parameters. Using genetic detection data collected via fecal sampling at latrines, we demonstrate applicability of the spatial capture–recapture (SCR) network distance function for estimating the size and density of a recently reintroduced North American river otter (Lontra canadensis) population in the Upper Rio Grande River dendritic network in the southwestern United States, and we also evaluated the genetic outcomes of using a small founder group (n = 33 otters) for reintroduction. Estimated population density was 0.23–0.28 otter/km, or 1 otter/3.57–4.35 km, with weak evidence of density increasing with northerly latitude (β = 0.33). Estimated population size was 83–104 total otters in 359 km of riverine dendritic network, which corresponded to average annual exponential population growth of 1.12–1.15/year since reintroduction. Growth was ≥40% lower than most reintroduced river otter populations and strong evidence of a founder effect existed 8–10 years post-reintroduction, including 13–21% genetic diversity loss, 84%–87% genetic effective population size decline, and rapid divergence from the source population (FST accumulation = 0.06/generation). Consequently, genetic restoration via translocation of additional otters from other populations may be necessary to mitigate deleterious genetic effects in this small, isolated population. Combined with non-invasive genetic sampling, the SCR network distance approach is likely widely applicable to demogenetic assessments of both reintroduced and established populations of multiple mustelid species that inhabit aquatic dendritic networks, many of which are regionally or globally imperiled and may warrant reintroduction or augmentation efforts
A Systematic Approach to Multiple Case Study Design in Professional Counseling and Counselor Education
Case study research is a qualitative methodology that allows researchers to explore complex phenomena in a structured way, that is rigorous and provides an enormous amount of depth. Three scholars are credited with major contributions to the case study literature: Merriam (1998), Stake (1995/2006), and Yin (1994). The purpose of this paper is to explore case study design for use in the counseling profession. The authors provide instruction on the case study scholars, data collection, analysis, and reporting for both single and multiple case study research designs. Finally, implications for student counselors, counselor educators, and counseling professionals are provided
Minimum Information about a Neuroscience Investigation (MINI) Electrophysiology
This module represents the formalized opinion of the authors and the CARMEN consortium, which identifies the minimum information required to report the use of electrophysiology in a neuroscience study, for submission to the CARMEN system (www.carmen.org.uk).

Using DNA Metabarcoding to Identify the Floral Composition of Honey:A New Tool for Investigating Honey Bee Foraging Preferences
Identifying the floral composition of honey provides a method for investigating the plants that honey bees visit. We compared melissopalynology, where pollen grains retrieved from honey are identified morphologically, with a DNA metabarcoding approach using the rbcL DNA barcode marker and 454-pyrosequencing. We compared nine honeys supplied by beekeepers in the UK. DNA metabarcoding and melissopalynology were able to detect the most abundant floral components of honey. There was 92% correspondence for the plant taxa that had an abundance of over 20%. However, the level of similarity when all taxa were compared was lower, ranging from 22–45%, and there was little correspondence between the relative abundance of taxa found using the two techniques. DNA metabarcoding provided much greater repeatability, with a 64% taxa match compared to 28% with melissopalynology. DNA metabarcoding has the advantage over melissopalynology in that it does not require a high level of taxonomic expertise, a greater sample size can be screened and it provides greater resolution for some plant families. However, it does not provide a quantitative approach and pollen present in low levels are less likely to be detected. We investigated the plants that were frequently used by honey bees by examining the results obtained from both techniques. Plants with a broad taxonomic range were detected, covering 46 families and 25 orders, but a relatively small number of plants were consistently seen across multiple honey samples. Frequently found herbaceous species were Rubus fruticosus, Filipendula ulmaria, Taraxacum officinale, Trifolium spp., Brassica spp. and the non-native, invasive, Impatiens glandulifera. Tree pollen was frequently seen belonging to Castanea sativa, Crataegus monogyna and species of Malus, Salix and Quercus. We conclude that although honey bees are considered to be supergeneralists in their foraging choices, there are certain key species or plant groups that are particularly important in the honey bees environment. The reasons for this require further investigation in order to better understand honey bee nutritional requirements. DNA metabarcoding can be easily and widely used to investigate floral visitation in honey bees and can be adapted for use with other insects. It provides a starting point for investigating how we can better provide for the insects that we rely upon for pollination
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