Characterization of Spatial and Environmental Influences On Stream Diatoms and Cyanobacteria

Primary producing algae form the basis of carbon fixation, oxygen production, and food webs in aquatic ecosystems globally. However, human activities disrupt climate and freshwater physicochemistry. These impacts alter the health of algal communities and the ecosystem services algae provide. Meanwhile, spatial processes like dispersal and landscape characteristics like geology also influence algal structure and function. Diatoms are indicators of stream health and are model organisms for understanding the processes underlying microbial biogeography. Benthic cyanobacteria present risks to human health through the proliferation of toxin-producing blooms. With this dissertation, I investigate the ecosystem processes that influence diatom and cyanobacterial community composition and taxon distributions. My goal is to advance the understanding of ecosystem controls on algal biogeography and to characterize taxon-specific autecology for use in environmental management. First, I measured the extent of wind-mediated dispersal of benthic diatoms across aquatic habitats to better understand how community composition is structured by spatial processes across the McMurdo Dry Valleys polar desert in Antarctica. I found that inter-habitat dispersal is common but less influential on community composition than intra-habitat factors such as environmental conditions. I then used non-linear, multivariable modeling to assess the relative influences of climate, watershed characteristics, and in-stream stressors on the relative abundances of 268 diatom taxa across gradients of human impact in the northeast United States. My results indicate diatom taxa are affected by different suites of environmental conditions but that taxa belong to ecological guilds based on shared responsiveness to environmental factors. Finally, I applied multivariable modeling towards understanding the effects of aquatic stressors, including herbicides and persistent organic pollutants, on the distributions of benthic cyanobacteria across northeast U.S. streams. I found that watershed characteristics, streamflow, and herbicides were more influential than light availability, water temperature, and nutrients on the distributions of potentially toxigenic cyanobacterial genera. Collectively, this research expands the knowledge of how benthic algal communities and taxon distributions are structured at large spatial scales along gradients of unimpacted and human-altered environmental conditions. I provide a novel modeling framework and taxon-specific autecological information that can be applied to environmental assessments of stream health and future algal research.</p

Music\u27s Emotional Journey

Music has an emotion-evoking effect on its audience through form. This is exemplified throughout history, but we will be focusing on \u27Don\u27t Stop Believin\u27 \u27 by Journey as a prime example. Part of this influence is due to the fact that it contrast with other widely-used forms. Presentation Time: Thursday, 3-4 p.m

Earth construction in Algeria between tradition and modernity

In the south of Algeria, many indigenous settlements have been built using local earth construction techniques; in the north, despite the availability of suitable earth, only a few rural contemporary settlements have been built using ‘improved’ earth construction. This paper adopts a case study approach to examine and compare structural deficiencies of two earth-built housing settlements in different regions in Algeria. In the indigenous earth settlement in the south, where adobe was used in combination with local timber and stones, the dwellings exhibit many structural defects. Stabilisation of the soil and introduction of modern materials in the contemporary rammed earth settlement in the north has not, however, helped produce structurally adequate dwellings. These dwellings also exhibited many cracks and debonding of rendering, and thus did not fulfil the requirements and aspirations of their occupants. The study concludes that for a potentially successful earth building scheme there are inter-related factors that should be considered: selection of an appropriate soil and construction technique, implementation of a suitable structural design, construction and post-completion processes, availability of relevant skills and provision of adequate training on the construction technique

Bird species involved in west nile virus epidemiological cycle in southern Québec

Despite many studies on West Nile Virus (WNV) in the US, including the reservoir role of bird species and the summer shifts of the Culex mosquito, feeding from birds to mammals, there have been few equivalent studies in the neighboring regions of Canada where WNV is endemic. Here, a priority list of bird species likely involved in WNV transmission in the greater Montréal area is constructed by combining three sources of data: (i) from WNV surveillance in wild birds (2002–2015); (ii) blood meal analysis of Culex pipiens–restuans (CPR), the primary enzootic vectors of WNV in the region, collected from surveillance in 2008 and 2014; (iii) literature review on the sero-prevalence/host competence of resident birds. Each of these data sources yielded 18, 23 and 53 species, and overall, 67 different bird species were identified as potential WNV amplifiers/reservoirs. Of those identified from CPR blood meals, Common starlings, American robins, Song sparrows and House sparrows ranked the highest and blood meal analysis demonstrated a seasonal shift in feed preference from birds to mammals by CPR. Our study indicates that there are broad similarities in the ecology of WNV between our region and the northeastern US, although the relative importance of bird species varies somewhat between regions

Population genetics, taxonomy, phylogeny and evolution of Borrelia burgdorferi sensu lato

In order to understand the population structure and dynamics of bacterial microorganisms, typing systems that accurately reflect the phylogenetic and evolutionary relationship of the agents are required. Over the past 15 years multilocus sequence typing schemes have replaced single locus approaches, giving novel insights into phylogenetic and evolutionary relationships of many bacterial species and facilitating taxonomy. Since 2004, several schemes using multiple loci have been developed to better understand the taxonomy, phylogeny and evolution of Lyme borreliosis spirochetes and in this paper we have reviewed and summarized the progress that has been made for this important group of vector-borne zoonotic bacteria

Some quit, others persist: similarities and disparities of healthcare providers' speech concerning obesity

Background Recent studies indicate that healthcare providers, especially in primary healthcare, have negative beliefs and attitudes towards obese, which are negatively affecting their practices by not taking this issue as seriously as they should and, therefore, compromising the success of obesity treatment. However, data is not conclusive and quantitative research is not being able to clarify how health professionals' practices and roles are affected by the way they perceive obesity and obese people. Method Semi-structured interviews about beliefs, attitudes and practices about obesity were conducted withe Portuguese general practitioners, nutritionists and nurses working in primary health care centers in the north of Portugal. Data was analyzed according to thematic analysis' procedures. Results The main themes indicate that all groups are concerned about the obesity pandemic and have similar negative beliefs and attitudes toward obese, who are described as being unmotivated, noncompliant and demonstrating a passive coping and a lack of understanding about the gravity of their condition. General practitioners, due to patients' lack of compliance and success, feel frustrated, have lower expectations of efficacy and are negative about their role in the treatment, giving up in most of the cases. Nutritionists and nurses demonstrate an active role, are persistent, perceived themselves as being able to positively modify obese motivation and believe in the success of the interventions, which, however, are described as a constant struggle between them and the patients. It seems to exist communication problems between these three groups. Discussion In order to achieve success, healthcare providers should be aware of how their beliefs and attitudes can influence their practices. Education and training concerning treatment options and communications skills should be improved as well as a bigger emphasis should be put on a multidisciplinary approach to obesity.Introdução Investigações recentes no âmbito da obesidade sugerem que as crenças, atitudes e práticas de vários profissionais de saúde, principalmente ao nível dos cuidados de saúde primários, parecem estar a influenciar negativamente o comportamento destes técnicos no tratamento desta doença, não lhe dando a devida importância e contribuindo para a manutenção das taxas de obesidade. As críticas têm apontado para a primazia de investigações quantitativas e para a ausência de estudos comparativos com diferentes grupos de profissionais de saúde. Método Neste estudo foram realizadas entrevistas semiestruturadas a médicos de família, nutricionistas e enfermeiros, a laborar em centros de saúde dos distritos de Braga, Porto e Aveiro. As entrevistas foram transcritas e analisadas, segundo os princípios da análise temática. Resultados Os 3 grupos apresentam crenças e atitudes negativas em relação aos obesos, que são descritos como desmotivados e passivos face ao tratamento, não aderindo na maioria das vezes, visto desvalorizarem a obesidade enquanto problema de saúde. Os médicos de família possuem baixas expectativas de sucesso, sentindo‐se frustrados com a falta de adesão, o que os leva a adotar uma postura passiva e resignada face ao tratamento. Os nutricionistas e enfermeiros percecionam‐se como agentes ativos, considerando‐se capazes de influenciar a motivação dos obesos; acreditam no seu sucesso, mas descrevem o processo como uma luta constante. Há várias referências a problemas de comunicação entre os 3 grupos de profissionais. Discussão Para uma maior eficácia no tratamento da obesidade torna‐se peremptório alertar os profissionais de saúde para o impacto que as suas crenças poderão exercer na prática, reforçar a abordagem multidisciplinar e promover o aumento dos conhecimentos e de opções de tratamento, e a melhoria da comunicação entre os vários profissionais(undefined)info:eu-repo/semantics/publishedVersio

Assessing the functional significance of ecstasy-related memory deficits using a virtual paradigm

Rationale/Objectives: Previous research shows that the use of ecstasy results in working memory and executive impairments in some users. The present study sought to assess the functional significance of such deficits using a virtual reality task. Methods: Twenty-three ecstasy-polydrug users and 26 nonusers were recruited. Individuals completed a drug use questionnaire measures of sleep quality and fluid intelligence. Participants also completed a virtual reality executive function task in which they play the role of an office worker for the day completing predefined tasks such as prioritising different activities according to their importance, organising the physical office environment and managing the outgoing mail in accordance with a delivery schedule. Results: MANOVA revealed that ecstasy users performed worse on the virtual reality task overall, and this was due to poorer performance on the planning and selection subscales. Contrary to expectations, ecstasy-polydrug users performed better on the time-based prospective memory subscale. Indices of ecstasy use were correlated with the planning subscale of the virtual task. Conclusions: The present study provides further support for ecstasy/polydrug related deficits in executive functioning. As it is possible that this task is more ecologically valid and relevant to day-to-day activities of many users, previous research finding null results on executive function tasks may have underestimated the impact of ecstasy-polydrug use on executive functioning

Dimensions of distance: international flight connections, historical determinism, and economic relations in Africa

Purpose: The paper examines how distance manifests in terms of air passenger transport links between countries and focuses on the 48 countries of sub-Saharan Africa (SSA). It asks to what extent do existing flight connections reflect economic relations between countries and if so, do they represent past, current or future relations? It asks whether the impact of distance is similar for all countries and at different stages of development. Design/methodology/approach: Passenger flight connection data was extracted to generate map images and flight frequencies in order to observe inter-relationships between different locations and to observe emerging patterns. The paper uses ESRIs ArcGIS software to visualise all these data into maps. Findings: SSA is poorly connected both intra- and inter-continentally. Cultural and historical ties dominate and elements of historical determinism appear within flight connections in SSA reflecting the biases associated with colonialism. Larger economies in SSA are less dependent on these past ties and their flight connections reveal a greater level of diversity and interests. SSA has generally been slow to develop flight routings to the new emerging markets. Originality/value: Its contribution lies not only in examining these flight patterns for an under-researched region but aides in future work on SSA and its integration into the global economy and international business networks. It argues that whilst distance matters; how it matters varies