Comparative study of periphyton community structure in long and short-hydroperiod Everglades marshes

The Florida Everglades is a mosaic of short and long-hydroperiod marshes that differ in the depth, duration, and timing of inundation. Algae are important primary producers in widespread Everglades’ periphyton mats, but relationships of algal production and community structure to hydrologic variability are poorly understood. We quantified differences in algal biomass and community structure between periphyton mats in 5 short and 6 long-hydroperiod marshes in Everglades National Park (ENP) in October 2000. We related differences to water depth and total phosphorus (TP) concentration in the water, periphyton and soils. Long and short-hydroperiod marshes differed in water depth (73 cm vs. 13 cm), periphyton TP concentrations (172μg g−1 vs. 107 μg g−1, respectively) and soil TP (284 μg g−1 vs. 145 μg g−1). Periphyton was abundant in both marshes, with short-hydroperiod sites having greater biomass than long-hydroperiod sites (2936 vs. 575 grams ash-free dry mass m−2). A total of 156 algal taxa were identified and separated into diatom (68 species from 21 genera) and “soft algae” (88 non-diatom species from 47 genera) categories for further analyses. Although diatom total abundance was greater in long-hydroperiod mats, diatom species richness was significantly greater in short- hydroperiod periphyton mats (62 vs. 47 diatom taxa). Soft algal species richness was greater in long-hydroperiod sites (81 vs. 67 soft algae taxa). Relative abundances of individual taxa were significantly different among the two site types, with soft algal distributions being driven by water depth, and diatom distributions by water depth and TP concentration in the water and periphyton. Periphyton communities differ between short and long-hydroperiod marshes, but because they share many taxa, alterations in hydroperiod could rapidly

Comparison of community structure of mangrove and riprap rock habitats along urban coastlines of south Florida

Globally, mangrove ecosystems have substantially declined, largely a result of human impacts. Mangroves provide a number of ecosystem services such as shoreline stabilization and nursery habitat for fish species. As declines continue, many of these ecosystem services are lost or altered. The need for shoreline stabilization has become increasingly apparent when chronic erosion wear away coastlines once mangroves are removed. Limestone boulders called riprap have been employed to offset continued erosion associated with mangrove clearing. In urban coastal areas adjacent to Biscayne Bay, Florida, as much as 80 percent of mangroves have been lost. More recently, riprap has been used in conjunction with mangroves to restore wetlands throughout the Bay. This riprap-mangrove habitat provides structure for marine organisms to colonize. However, fish assemblages and benthic composition could vary between this hybridized habitat and natural mangrove systems. Comparisons of fish and benthic community structure were made, to determine if abundance, species richness, and overall diversity differed between the two habitat types. Visual census and benthic quadrat surveys were conducted in vi mangrove and mangrove-riprap sites within two regions of Biscayne Bay. Total fish abundance was greater in mangroves, but the effect of habitat type on species richness varied between regions. The community structure of fishes and benthic composition differed significantly between mangroves and riprap habitats. Because species composition is so distinct, it is likely that the two communities do no function in the same manner. In areas with cleared shorelines, it may be important to consider the function of added anthropogenic structure for ecological communities.

HPA Axis Activation by Ethanol Dependence in Adult and Adolescent Rats

Alcoholism is a disorder marked by cycles of heavy drinking and chronic relapse, and adolescents are an age cohort particularly susceptible to consuming large amounts of alcohol, placing them at high risk for developing an alcohol use disorder. Adolescent humans and rats voluntarily consume more alcohol than their adult counterparts, suggesting that younger consumers of alcohol may be less sensitive to its aversive effects, which are regulated by the function of the hypothalamic-pituitary-adrenal (HPA) stress axis. While HPA axis dysfunction resulting from ethanol exposure has been extensively studied in adult animals, what happens in the adolescent brain remains largely unclear. In this study, chronic injections of ethanol was used to model alcohol dependence in adult and adolescent rats, and post-withdrawal anxiety behaviors were measured using light-dark box testing. Furthermore, corticosterone (CORT) release during treatment and after withdrawal was measured by collecting fecal and plasma samples from adults and adolescents. It was found that adults, but not adolescents, exhibit significant anxiety-like behavior following chronic ethanol withdrawal. Additionally, while the process of chronic ethanol treatment elicits an increase in day-by-day CORT release in both adults and adolescents, significantly sustained levels of CORT were not observed during withdrawal for either age group. Moreover, it was found that adults experience a longer-lasting CORT increase during chronic treatment, suggesting a larger and more robust period of dysfunction in the HPA axis for older consumers of alcohol. These results highlight CORT and glucocorticoids in general as a potential therapeutic target for treatment for alcoholism, especially that which has an onset during adolescence.

Evaluation of Community-led Complementary Feeding and Learning Sessions

Thesis (Master's)--University of Washington, 2016-08

Role of assessment components and recent adverse outcomes in risk estimation and prediction: use of the Short Term Assessment of Risk and Treatability (START) in an adult secure inpatient mental health service

The Short Term Assessment of Risk and Treatability is a structured judgement tool used to inform risk estimation for multiple adverse outcomes. In research, risk estimates outperform the tool's strength and vulnerability scales for violence prediction. Little is known about what its’component parts contribute to the assignment of risk estimates and how those estimates fare in prediction of non-violent adverse outcomes compared with the structured components. START assessment and outcomes data from a secure mental health service (N=84) was collected. Binomial and multinomial regression analyses determined the contribution of selected elements of the START structured domain and recent adverse risk events to risk estimates and outcomes prediction for violence, self-harm/suicidality, victimisation, and self-neglect. START vulnerabilities and lifetime history of violence, predicted the violence risk estimate; self-harm and victimisation estimates were predicted only by corresponding recent adverse events. Recent adverse events uniquely predicted all corresponding outcomes, with the exception of self-neglect which was predicted by the strength scale. Only for victimisation did the risk estimate outperform prediction based on the START components and recent adverse events. In the absence of recent corresponding risk behaviour, restrictions imposed on the basis of START-informed risk estimates could be unwarranted and may be unethical.

Peripheral communities of the Eastern Lau Spreading Center and Valu Fa Ridge: community composition, temporal change and comparison to near-vent communities

Western Pacific hydrothermal vents will soon be subjected to deep-sea mining and peripheral sites are considered the most practical targets. The limited information on community dynamics and temporal change in these communities makes it difficult to anticipate the impact of mining activities and recovery trajectories. We studied community composition of peripheral communities along a cline in hydrothermal chemistry on the Eastern Lau Spreading Center and Valu Fa Ridge (ELSC-VFR) and also studied patterns of temporal change. Peripheral communities located in the northern vent fields of the ELSC-VFR are significantly different from those in the southern vent fields. Higher abundances of zoanthids and anemones were found in northern peripheral sites and the symbiont-containing mussel Bathymodiolus brevior, brisingid seastars and polynoids were only present in the northern peripheral sites. By contrast, certain faunal groups were seen only in the southern peripheral sites, such as lollipop sponges, pycnogonids and ophiuroids. Taxonomic richness of the peripheral communities was similar to that of active vent communities, due to the presence of non-vent endemic species that balanced the absence of species found in areas of active venting. The communities present at waning active sites resemble those of peripheral sites, indicating that peripheral species can colonize previously active vent sites in addition to settling in the periphery of areas of venting. Growth and mortality were observed in a number of the normally slow-growing cladorhizid stick sponges, indicating that these animals may exhibit life history strategies in the vicinity of vents that differ from those previously recorded. A novel facultative association between polynoids and anemones is proposed based on their correlated distributions.

Bacterial community characterization of water and intestine of the shrimp Litopenaeus stylirostris in a biofloc system

Background Biofloc technology (BFT), a rearing method with little or no water exchange, is gaining popularity in aquaculture. In the water column, such systems develop conglomerates of microbes, algae and protozoa, together with detritus and dead organic particles. The intensive microbial community presents in these systems can be used as a pond water quality treatment system, and the microbial protein can serve as a feed additive. The current problem with BFT is the difficulty of controlling its bacterial community composition for both optimal water quality and optimal shrimp health. The main objective of the present study was to investigate microbial diversity of samples obtained from different culture environments (Biofloc technology and clear seawater) as well as from the intestines of shrimp reared in both environments through high-throughput sequencing technology. Results Analyses of the bacterial community identified in water from BFT and “clear seawater” (CW) systems (control) containing the shrimp Litopenaeus stylirostris revealed large differences in the frequency distribution of operational taxonomic units (OTUs). Four out of the five most dominant bacterial communities were different in both culture methods. Bacteria found in great abundance in BFT have two principal characteristics: the need for an organic substrate or nitrogen sources to grow and the capacity to attach to surfaces and co-aggregate. A correlation was found between bacteria groups and physicochemical and biological parameters measured in rearing tanks. Moreover, rearing-water bacterial communities influenced the microbiota of shrimp. Indeed, the biofloc environment modified the shrimp intestine microbiota, as the low level (27 %) of similarity between intestinal bacterial communities from the two treatments. Conclusion This study provides the first information describing the complex biofloc microbial community, which can help to understand the environment-microbiota-host relationship in this rearing system.

Massachusetts College of Art and Design y Universidad de Cuenca. Acuerdo de Intercambio Estudiantil. Memorándum de Acuerdo entre Massachusetts College of Art and Design (Massart), Boston, Massachusetts, U:S:A. y la Universidad de Cuenca, Ecuador

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Retail centers for community : addressing both pedestrian and car traffic

The purpose of this thesis was to redesign a commercial center in Miami, Florida in a manner that incorporates the needs of pedestrians as well as the automobile. In my research, I studied projects that had been successful at integrating cars in retail design. I applied the strategies learned from this research to the design of a center that creates a positive interaction of pedestrian and car traffic, addressing the needs of the surrounding community. I designed a master plan that includes a mix of residential, retail, commercial and parking space. The parking is designed so that the retail center is not dominated by surface parking. Rather, the automobile is introduced into the different layers of the proposed buildings. The design focused on connecting pedestrian plazas and parking areas beneath them through the introduction of light and greenery. The findings show how a shopping center might transform the area around it by including spaces for residential, civic, cultural and social functions, as well as for the automotive infrastructure that make those functions possible.

Professor gender, age, and “hotness” in influencing college students’ generation and interpretation of professor ratings

Undergraduate psychology students rated expectations of a bogus professor (randomly designated a man or woman and hot versus not hot) based on an online rating and sample comments as found on RateMyProfessors.com (RMP). Five professor qualities were derived using principal components analysis (PCA): dedication, attractiveness, enhancement, fairness, and clarity. Participants rated current psychology professors on the same qualities. Current professors were divided based on gender (man or woman), age (under 35 or 35 and older), and attractiveness (at or below the median or above the median). Using multivariate analysis of covariance (MANCOVA), students expected hot professors to be more attractive but lower in clarity. They rated current professors as lowest in clarity when a man and 35 or older. Current professors were rated significantly lower in dedication, enhancement, fairness, and clarity when rated at or below the median on attractiveness. Results, with previous research, suggest numerous factors, largely out of professors’ control, influencing how students interpret and create professor ratings. Caution is therefore warranted in using online ratings to select courses or make hiring and promotion decisions.