Seedling Emergence from Seed Banks in Ludwigia hexapetala-Invaded Wetlands: Implications for Restoration

Soil seed banks play a critical role in the maintenance of wetland plant communities and contribute to revegetation following disturbances. Analysis of the seed bank can therefore inform restoration planning and management. Emergence from seed banks may vary in response to hydrologic conditions and sediment disturbances. To assess the community-level impact of exotic Ludwigia hexapetala on soil seed banks, we compared differences in species composition of standing vegetation among invaded and non-invaded wetlands and the degree of similarity between vegetation and soil seed banks in northern California. To determine potential seed bank recruitment of L. hexapetala and associated plant species, we conducted a seedling emergence assay in response to inundation regime (drawdown vs. flooded) and sediment depth (surface vs. buried). Plant species richness, evenness, and Shannon’s H’ diversity were substantially lower in standing vegetation at L. hexapetala invaded sites as compared to non-invaded sites. Over 12 months, 69 plant taxa germinated from the seed banks, including L. hexapetala and several other exotic taxa. Seedling density varied among sites, being the highest (10,500 seedlings m−2) in surface sediments from non-invaded sites subjected to drawdown treatments. These results signal the need for invasive plant management strategies to deplete undesirable seed banks for restoration success

Effect of Environmental Optimism on Responsible Electricity Consumption with Price Concern as a Moderator

The study aimed to determine the effect of environmental optimism, as a cognitive–emotional factor, on the responsible use of electricity. Furthermore, it investigated the moderating effect of consumer concern on the price of electricity. An online survey was conducted on 345 young adults in Jakarta selected through the snowball sampling method. Data were analyzed using JASP version 15.0 and IBM SPSS Statistics version 23 reinforced with PROCESS macro. Simple linear regression analysis demonstrated that environmental optimism significantly explains the variance in electricity conservation behavior. The moderating effect of price concern was also substantiated by the result of the data analysis, thus the interaction between environmental optimism and dichotomous predictors of price concern (i.e. high vs low) was found to be statistically significant in moderating the effect of environmental optimism toward electricity conservation behavior. In conclusion, when consumers are initially dominated by price concern (a rational extrinsic motivator), then it reduces the effect of environmental optimism (an emotional intrinsic motivator) on responsible electricity consumption

Indirect functional effects of neighbors on food web compartments could not overcome density-dependent limited growth of a grazing minnow

Ecosystems include diverse taxonomic and functional groups of animals with variable levels of niche overlap that can lead to direct and indirect interactions with positive or negative outcomes. Species feeding at low trophic positions might be sensitive to interactions with co-occurring functional groups (neighbors) that influence their food resources through various processes, such as indirect nutrient subsidies and trophic cascades. Employing a target-neighbor experimental design using large, outdoor mesocosms, we tested whether adding neighbors with different functional traits affected food web compartments relative to a control group that had grazing minnows, Campostoma anomalum (Central Stoneroller). Additionally, we tested whether growth and body condition of Central Stoneroller was positively influenced through interactions with each neighbor treatment: additional stonerollers, benthic-insectivorous fish Etheostoma spectabile (Orangethroat Darter), terrestrial insectivorous fish Lepomis megalotis (Longear Sunfish), or filter-feeding mussels (two-species assemblage) that are predicted to increase primary production through nutrient enrichment, a trophic cascade or both. Over the 29-day experiment, the presence of neighbors had generally negative or highly variable effects on food web compartments. Stoneroller growth was not evident during the experiment and body condition generally declined but was not influenced by neighbor treatments. Our results show that adding neighboring functional group did not reduce density-dependent growth of grazing fishes via indirect food web interactions over short temporal scales. This study suggested that indirect interactions among species and their combined influence on ecosystem properties were weak under experimental conditions representing typical prairie stream communities

Of cattle, sand flies and men : a systematic review of risk factor analyses for South Asian visceral leishmaniasis and implications for elimination

Background: Studies performed over the past decade have identified fairly consistent epidemiological patterns of risk factors for visceral leishmaniasis (VL) in the Indian subcontinent. Methods and Principal Findings: To inform the current regional VL elimination effort and identify key gaps in knowledge, we performed a systematic review of the literature, with a special emphasis on data regarding the role of cattle because primary risk factor studies have yielded apparently contradictory results. Because humans form the sole infection reservoir, clustering of kala-azar cases is a prominent epidemiological feature, both at the household level and on a larger scale. Subclinical infection also tends to show clustering around kala-azar cases. Within villages, areas become saturated over a period of several years; kala-azar incidence then decreases while neighboring areas see increases. More recently, post kalaazar dermal leishmaniasis (PKDL) cases have followed kala-azar peaks. Mud walls, palpable dampness in houses, and peridomestic vegetation may increase infection risk through enhanced density and prolonged survival of the sand fly vector. Bed net use, sleeping on a cot and indoor residual spraying are generally associated with decreased risk. Poor micronutrient status increases the risk of progression to kala-azar. The presence of cattle is associated with increased risk in some studies and decreased risk in others, reflecting the complexity of the effect of bovines on sand fly abundance, aggregation, feeding behavior and leishmanial infection rates. Poverty is an overarching theme, interacting with individual risk factors on multiple levels. Conclusions: Carefully designed demonstration projects, taking into account the complex web of interconnected risk factors, are needed to provide direct proof of principle for elimination and to identify the most effective maintenance activities to prevent a rapid resurgence when interventions are scaled back. More effective, short-course treatment regimens for PKDL are urgently needed to enable the elimination initiative to succeed

Myoclonus in adult Huntington's disease

Two brothers with clinically definite adult Huntington's disease developed disabling myoclonus years after the first signs of the disease. Their electroencephalograms were consistent with a primary generalized epilipsy, although neither man had seizures. The myoclonus was controlled with valproic acid therapy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50341/1/410290217_ftp.pd

High aqueous salinity does not preclude germination of invasive Iris pseudacorus from estuarine populations

Estuarine ecosystems are threatened by climate change and biological invasions. Among global changes, sea-level rise is broadly impacting tidal wetlands, through increases in salinity and alteration of inundation regimes. Extant freshwater plant species are often presumed to be limited to reaches of estuaries with low salinity and narrow tidal ranges. However, the potential for invasive freshwater species (e.g., Iris pseudacorus) to persist and spread with increased salinity and flooding is poorly understood and can jeopardize native biodiversity and other wetland ecosystem services. The successful establishment of invasive plants will be dependent on their tolerance to salinity and inundation, starting with the germination life stage. Changes to abiotic estuarine gradients may alter the germination process of tidal wetland plant species that underlies significant patterns of plant community composition and biodiversity. We explored germination responses of seeds from two invasive I. pseudacorus populations from freshwater and brackish tidal sites in California’s San Francisco Bay–Delta Estuary. We tested germination dynamics under salinity levels ranging from freshwater to seawater (0, 12.5, 25, and 45 dS/m) and two hydrological conditions (moist and flooded). Salinity levels >12.5 dS/m inhibited germination of seeds from both populations, consistent with viviparism and seedling emergence recorded at field sites. However, seeds exposed to seawater for 55 d germinated once exposed to freshwater. Germination velocity and seed buoyancy differed between populations, likely due to differences in seed coat thickness. Our results demonstrate that after 55 d in seawater, buoyant seeds of I. pseudacorus retain their ability to germinate, and germinate quickly with freshwater exposure. This suggests that invasive populations of I. pseudacorus can colonize new sites following potentially long-distance dispersal of buoyant seeds with tidal currents. These findings inform risk assessments and highlight the need to prioritize the management of invasive I. pseudacorus in estuarine ecosystems impacted by rising sea level

Do mobile consumers homogenize the distribution of resources in stream food webs? A test with overlapping fish and mussel aggregations

In streams, unionoid mussels and fish form aggregations that exert bottom-up and top-down effects on food webs, but the magnitude and spatial extent of their effects are controlled by species traits. Sedentary mussels live burrowed in the sediment in patchily distributed dense aggregations (mussel beds) where they filter seston and provide a local, relatively constant nutrient subsidy. In contrast, fish move on and off mussel beds, and thus comprise a transient nutrient subsidy. We asked how overlap between fish and mussels influences nutrient recycling and resource distribution in streams. We conducted an 8-week study in experimental streams where we created mussel beds (comprised of two species, Actinonaias ligamentina and Amblema plicata), manipulated the occurrence of a grazing minnow (Campostoma anomalum), and tracked nutrient (nitrogen and phosphorus) and resource (algae, detritus, and chironomids) abundance up and downstream of the mussel beds. In general, neither consumer had strong effects on the concentration or spatial distribution of nutrients. Water turnover time in our experimental streams may have diluted fish and mussel nutrient excretion effects, making it difficult to detect spatial patterns during a given sampling period. Fish controlled the abundance and productivity of algae. In treatments without fish, large mats of filamentous algae formed early in the experiment. These algae senesced, decomposed, and were not replaced. When fish were present, algae consisted of attached biofilms with consistent biomass and spatial distribution over time. Although previous work has shown that mussels can have strong, seasonal bottom-up effects on both primary and secondary production, our results suggested that adding grazing mobile fishes, led to a more consistent and homogenous supply of algal resources. Because mussels rarely occur in the absence of fish, considering their combined influence on ecosystem dynamics is likely to be important

Cognitive and Behavioral Resilience Among Young Gay and Bisexual Men Living with HIV

Purpose: HIV/AIDS disproportionately affects young gay, bisexual, and other men who have sex with men (Y-GBMSM). Resilience remains understudied among Y-GBMSM living with HIV, but represents a potentially important framework for improving HIV-related outcomes in this population. We sought to explore cognitive and behavioral dimensions of resilience and their correlates among Y-GBMSM to gain insights to inform future interventions

Finding common ground: identifying and eilciting metacognition in ePortfolios

Research has suggested ePortfolios reveal and support students’ metacognition, that is, their awareness, tracking, and evaluation of their learning over time. However, due to the wide variety of purposes and audiences for ePortfolios, it has been unclear whether there might be common criteria for identifying and assessing metacognition in ePortfolios across varied contexts. The purpose of this study was to identify evidence of metacognition across ePortfolios of three distinct populations of students: traditional-age undergraduates, graduate Education students, and adults returning to school to complete a bachelor’s degree. We set out to explore if and how ePortfolios could support these different learners’ growth as reflective, intentional learners and professionals. Through a qualitative coding process, we identified four key metacognition markers across students’ ePortfolios in these three populations. We conclude students can be guided to engage in metacognition in ways through thoughtful assignment design and assessment process, no matter their context