O glutamato, quando em altas concentrações na fenda sináptica, é excitotóxico, podendo levar à morte celular devido à hiper-estimulação de seus receptores. Seu efeito neurotóxico tem sido relacionado a várias doenças agudas e crônicas do SNC, tais como isquemia, epilepsia, Alzheimer e Parkinson. A manutenção dos níveis de glutamato abaixo de seus níveis excitotóxicos é realizada através de um mecanismo de transporte de alta afinidade dependente de sódio. Os principais transportadores de glutamato, GLAST e GLT-1, estão presentes nos astrócitos. Alguns estudos demonstram que a captação de glutamato parece variar de acordo com o período de desenvolvimento e envelhecimento; entretanto, poucos estudos avaliam este parâmetro em animais imaturos, maduros e velhos utilizando uma única metodologia. Neste trabalho, nós traçamos um perfil ontogenético da captação de glutamato in vitro, durante o desenvolvimento e envelhecimento, usando fatias de estriado, hipocampo e córtex de ratos com 10, 21 e 60 dias, 15 e 26 meses. Também analisamos se a captação de glutamato era sensível à presença de guanosina. Em todas as estruturas a captação de glutamato foi maior em animais jovens decaindo então, até ratos velhos (15 meses) em estriado e hipocampo ou ratos adultos jovens (60 dias) em córtex. Em estriado e hipocampo observamos um aumento parcial e total, respectivamente, na captação em ratos muito velhos (26 meses). O efeito da guanosina parece ser idade e estrutura dependentes, visto que a mesma aumentou a captação basal de glutamato somente em fatias de córtex de ratos de 10 dias. A diminuição da captação de glutamato observada em animais com 15 meses em estriado e hipocampo pode estar relacionada às diversas desordens neurodegenerativas que ocorrem em idosos, e a recuperação deste parâmetro em ratos muito velhos (26 II meses), tanto parcial como total, parece ser um mecanismo de adaptação compensatório que pode estar ocorrendo durante o processo de envelhecimento.

Made available in DSpace on 2014-06-12T23:13:55Z (GMT). No. of bitstreams: 2 arquivo2674_1.pdf: 1127241 bytes, checksum: 36a98959942987b2af227e822b9738a8 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / Foi realizado o levantamento fitossociológico em sítios com três diferentes históricos de uso, em Santa Terezinha, na Paraíba (07º 00 S e 37º 23 W): vegetação nativa regenerando há 10 anos (R10); vegetação nativa regenerando há 25 anos (R25); e caatinga madura com mais de 50 anos, sem maior antropismo (C50). Em C50, foram estimadas as quantidades de nitrogênio fixadas anualmente, medindo as proporções de N fixado (%Ndda) e as quantidades de N nas biomassas de folhas de leguminosas arbóreas. Para cada histórico foram demarcadas três parcelas de 20 x 50m e em cada uma foram medidas todas as plantas com diâmetro do caule 3 cm. O %Ndda em C50 foi calculado comparando as concentrações de 15N das plantas leguminosas e de referência. A biomassa de folhas foi estimada usando equações alométricas baseadas nos diâmetros dos caules a altura do peito (DAP). Em R10, R25 e C50, foram encontradas 4, 13 e 16 espécies e em todos os sítios 17 espécies, pertencendo a 17 gêneros e 12 famílias. São valores de riqueza mais baixos que os registrados para a maioria de outras caatingas, mas semelhantes aos de outras áreas da Depressão de Patos e do Seridó do Rio Grande do Norte. Os valores de densidades (693, 1100 e 1200 ind.ha-1), áreas basais (5,8, 6,3 e 11,0 m2.ha-1), áreas de copa (6045, 6280 e 8460 m2.ha- 1) e biomassas aéreas (29, 30 e 52 Mg.ha-1) também foram mais baixos que os citados na literatura para outras áreas de caatinga. Estes dados comprovam o baixo porte e a fisionomia aberta da caatinga, mesmo na área de caatinga madura. O número proporcionalmente mais baixo de espécies que das outras variáveis, em R10 em relação a C50, indica que a riqueza leva mais tempo para se recuperar que a estrutura da comunidade. R10 foi dominada por Mimosa tenuiflora (>98% das medidas) que ainda era importante em R25 (50% das medidas), mas não em C50 (<4%). A Caesalpinia pyramidalis teve um padrão inverso, mas só atingiu 30-35% das medidas em C50, dividindo a dominância com Piptadenia stipulacea e Commiphora leptophloeos. Mimosa tenuiflora, Piptadenia stipulacea e Anadenanthera colubrina tiveram grandes proporções de seus conteúdos de N derivado da atmosfera. O número de espécies fixadoras em C50 foi baixo, e a biomassa de folhas correspondeu de 5 a 10% da biomassa total. A quantidade de N nas folhas foi maior nas leguminosas do que nas não11 leguminosas. A baixa densidade de plantas e a baixa biomassa de folhas das espécies fixadoras contribuíram para que fosse relativamente baixa a quantidade N fixado nas folhas (10,6 a 15,1 kg.ha-1). Embora baixa, é quase duas vezes o valor estimado para o agreste

M.Tech. (Homoeopathy) / It is estimated that more than 29% of South African men and 56% of women are overweight or obese (Goedecke et al., 2005). Obesity can be classified as a chronic disease, with a number of detrimental health consequences, including the risk of developing insulin resistance, dyslipidaemia and hypertension (Beers et al., 2006). Conventional treatments for weight loss exist, but their use may be associated with unwanted side effects (Beers et al., 1999). While herbal medications are considered safer by many people, in general, studies of herbal medicinal products have been too few, of limited duration and small sample size (Mattsson and Nilsson, 2002). This indicates that further research into herbal weight loss treatments, with minimal or no side-effects, is required. The aim of this study is to determine the effect of a herbal formulation consisting of caffeine, Camellia sinensis, Coffea canephora bean, Coleus forskholii, Evodiamine, Ilex paraguariensis and Phaseolus vulgaris on human resting metabolic rate and body composition in overweight and obese individuals. The study was a double-blind, placebo-controlled study and formed part of a larger study where the research sample was shared by two additional researchers. A sample group of sixty healthy male and female participants between the ages of 18 and 45 years, with a body mass index of more than 25kg/m² and less than 35 kg/m², was recruited from the University of Johannesburg Doornfontein Campus Homoeopathic Health Clinic. Participants were randomly allocated into either an experimental or placebo group, in matched pairs according to gender and BMI. Both groups underwent an assessment of body composition and resting metabolic rate at the initial consultation, as well as at the two week, six week, and final twelve week follow-up consultations. Participant checklists recorded data documenting changes in general lifestyle factors for the duration of the study (Appendix E). The experimental group took two capsules of the herbal formulation daily and the control group took two capsules of the placebo, five days a week with a two day rest, for a period of twelve weeks. Data was collected and statistically analyzed using the Shapiro Wilk test, the Mann-Whitney test, the Friedman test, and the Wilcoxon signed ranks test (Smith, 2011).

Dopamine (DA) is a key neuromodulator in the striatum, and is important for action selection and reinforcement learning. Dysfunctions in striatal DA signalling contribute to numerous disorders including Parkinson’s disease (PD) and drug addiction. Midbrain DA neurons switch from low to high frequency firing in response to reward-related events, which is proposed to increase striatal DA release. However, in addition to DA neuron firing pattern, striatal DA signalling depends upon the short-term plasticity of DA release, which is controlled by presynaptic and local network factors. This thesis uses fast-scan cyclic voltammetry, in murine striatal slices, to detect subsecond changes in extracellular DA, and investigate the presynaptic control of striatal DA release and release plasticity. Acetylcholine from striatal cholinergic interneurons, acting at nicotinic receptors (nAChRs) on DA terminals, is one factor that strongly influences DA release. This thesis particularly explores how presynaptic factors interact with nAChRs to control DA release. Firstly, release probability, a key determinant of release plasticity at many synapses, was found to be only weakly related to DA release plasticity, and only when nAChRs are inactive. Secondly, a direct role of the DA uptake transporter (DAT) in controlling DA release plasticity was identified, when nAChRs are inactive. Thirdly, regional differences were identified in the role of the DAT in controlling DA release via control of D2 receptor activation, when nAChRs are active. Finally, mutant α-synuclein, which causes PD in humans, was found to only subtly affect striatal DA release. These data suggest that the control of striatal DA release differs substantially from other central transmitters. Release probability and α-synuclein play only minor roles, but nAChRs and the DAT significantly control DA release plasticity. These findings review our understanding of striatal DA release and may have implications for understanding the actions of drugs of abuse and early PD pathogenesis.

No description available.

This project studied the physical and chemical effects of typical impurities on CO2 storage using both experimental approaches and theoretical simulation. Results show that the presence of typical non-condensable impurities from oxyfuel combustion such as N2, O2, and Ar resulted in lower density than pure CO2, leading to decreased CO2 storage capacity and increased buoyancy in saline aquifers. In contrast, inclusion of condensable SO2 in CO2 resulted in higher density than pure CO2 and therefore increased storage capacity. These impurities also had a significant impact on the phase behaviours of CO2, which is important to CO2 transportation. Different effects on rock chemistry were detected with experimental systems containing pure CO2, CO2 with SO2, or CO2 with SO2 and O2 under conditions simulating that in a potential storage site. An equation was proposed to predict the effects of the rock chemistry on the porosity of rocks.

Huntington’s disease is an inherited neurodegenerative disease characterized by the degeneration of the cerebral cortex, thalamus, and striatum. The loss of neurons in the cerebral cortex and the thalamus may affect the synaptic circuitry in the striatum as these regions send glutamatergic projections (corticospinal & thalamostriatal) to neurons in the striatum. Prior studies have suggested the detrimental impact that the mutant Huntingtin protein (mHTT) may have on corticostriatal afferents, but less is known thalamic inputs to the dorsal striatum. In this study, we report a 50% reduction in thalamostriatal axospinous synapse density and significant reductions in dendritic spine volume at the ultrastructural level using electron microscopy. Additionally, dystrophic alterations to mitochondria size and morphology were also found. At the microcircuit level, we report a reduction in the spatial abundance of thalamostriatal axon terminals at the rostral, middle, and caudal levels of the dorsolateral striatum while an inverse distribution was observed for mHTT, suggesting a novel topographic distribution of thalamostriatal projections and mHTT along the rostral-caudal axis of the dorsolateral striatum. These findings are novel in the Q175 HD mouse model and supports the theory of an excitatory: inhibitory imbalance contributing to structural synaptic changes in the dorsal striatum. Further studies of the corticostriatal projections will determine the global extent of this imbalance.

No description available.

Avocado is an economically important crop with ~ 60-70 % oil, by dry weight, in its fruit mesocarp tissue. The steady increase in global demand for avocado (9% per year) has driven interest to identify the biochemical and molecular factors that regulate its triacylglycerol (TAG, oil) biosynthesis. Using 454- and Illumina-based RNA-Seq approaches, we examined the transcriptional basis for TAG biosynthesis in developing mesocarp of avocado, in relation to other seed and non-seed tissues. Deep transcriptional profiling data allowed us to identify several transcripts that were differentially represented between the early and late developmental stages of mesocarp. Additionally, in all oil-rich tissues analyzed, irrespective of the species, an increased expression was noted for genes mostly associated with fatty acid biosynthesis in plastid, but much less increase in those for TAG assembly in the endoplasmic reticulum. Transcripts associated with hexose metabolism in plastid also showed higher expression, relative to cytosol; this is likely associated with the need for high pyruvate flux directed toward plastid fatty acid synthesis. Moreover, WRINKLED1 transcription factor, a regulatory element associated with oil biosynthesis in seed and non-seed tissues of monocot and dicot plants, was identified in avocado as well. Our studies point to distinctive modes of regulation of fatty acid biosynthesis and TAG assembly that are conserved in both seed and non-seed oil-rich plants. In addition to improving avocado oil production, our study will lead to understanding regulation of oil biosynthesis in coordination with fruit development and identification of ways to generate oil-rich bioenergy crops; a direct implication for the science & society. This study provides an evolutionary insight into conserved nature of oil biosynthesis in a basal angiosperm (avocado) in relation to a monocot (oil palm) and a dicot (brassica). This research will lead to publications for students, sustain existing collaborations (Israel, CA, FL avocado researchers) and generate external funds.

Bakgrund: Depression är ett samhällsproblem i som ofta leder till samsjuklighet med fysisk eller psykisk sjukdom. Det främsta symtomet på depression är nedstämdhet, men det förekommer även fysiska symtom som smärta, muskelspänningar, svårigheter att andas och att kroppen känns främmande. Dessa symtom kan fysioterapeuter hjälpa till med genom att arbeta med basal kroppskännedom. Fysioterapeuter kan även använda sig av fysisk aktivitet som kan minska symtomen hos patienterna. Det finns få studier som beskriver fysioterapeutens perspektiv av att arbeta med patienter som har depression. Syfte: Syftet med studien var att utforska fysioterapeuters erfarenhet av att behandla patienter med depression inom öppenvårdspsykiatrin. Metod: Kvalitativ design med fenomenologisk ansats. Data samlades in genom tre semistrukturerade intervjuer med fysioterapeuter som arbetade inom öppenvårdspsykiatrin. Intervjuerna bearbetades med en kvalitativ innehållsanalys. Resultat: Analysen resulterade i fyra kategorier och tolv underkategorier. Kategorier som bildades var “komplexa diagnoser”, “varierande arbetsuppgifter”, “fysioterapeutiska interventioner” och “utmaningar”. Konklusion: Samtliga deltagare träffade patienter med en komplex symtombild där depression inte var den huvudsakliga diagnosen. De arbetade främst utifrån basal kroppskännedom, med kroppen som verktyg för att hjälpa patienterna att förstå och hantera kroppsliga besvär, för att patienterna skulle få en ny syn på kroppen. Motivation till fysisk aktivitet var även viktigt. Arbetet krävde en hög kompetensnivå hos fysioterapeuterna och en utmaning var att vara kreativ och individanpassa behandlingarna. Det behövs fler studier om fysioterapeuters erfarenheter av att arbeta inom psykiatrin både för att bekräfta det som denna studie beskrivit och för att få en djupare bild av deras erfarenheter.