Dans le monde entier les introductions d'espèces dans de nouvelles régions constituent une préoccupation écologique croissante ; ces introductions peuvent conduire à des modifications drastiques des écosystèmes, entre autres du fait de la compétition avec des espèces indigènes et également par la modification des réseaux de flux d'énergie dans les écosystèmes. La moule verte Perna viridis est une espèce récemment introduite dans les eaux côtières américaines et qui s'est rapidement disséminée le long des côtes du Sud-Est des États-Unis. Cependant, il n'existe pour le moment que très peu d'informations concernant la structure des populations, et leur dynamique en réponse à la variabilité environnementale locale. Les efflorescences de marées rouges formées par le dinoflagellé toxique Karenia brevis sont fréquentes le long des côtes de Floride bordant le Golfe du Mexique, et la tolérance de P. viridis à l'égard de ces événements et des brévitoxines (PbTx) associées n'est pas connue. En outre, comme P. viridis est une espèce invasive, la potentielle concurrence (ressources trophiques, espace, …) avec des bivalves indigènes comme l'huître Crassostrea virginica, est une préoccupation majeure dans les systèmes côtiers de Floride. Cette étude vise à caractériser la dynamique des populations établies de P. viridis populations établies et leur réponse aux efflorescences naturelles de K. brevis. Les effets des efflorescences à K. brevis ont été évalués à partir des résultats d'un suivi de la croissance, de la mortalité, du recrutement, de la gamétogenèse et de la composition biochimique des tissus (protéines, glycogène et lipides) durant trois ans. En outre, les concentrations en PbTx dans les tissus ont été analysées afin de déterminer l'absorption, l'accumulation et des taux d'élimination de ces toxines. Par ailleurs, les données recueillies sur le terrain et des informations de la littérature ont été utilisées pour élaborer un modèle énergétique individuel DEB pour modéliser la croissance et la reproduction de P. viridis. Avant l'apparition de la première efflorescence à K. brevis, P. viridis présentait des taux de croissance rapide (6-11 mm mois-1) et un taux de survie élevé (mortalité <1%). Au cours des efflorescences à K. brevis, le taux de croissance a chuté de façon significative et une bioaccumulation de PbTx dans les tissus mous a été observée. Les concentrations élevées en PbTx dans les tissus ont persisté longtemps après la dissipation de l'efflorescence et les taux de mortalité élevés se sont maintenus, ce qui a réduit fortement l'abondance de P. viridis. À la fin de l'efflorescence, la concentration en PbTx dans les moules était presque le double de celle relevée chez l'huître indigène Crassostrea virginica pour des individus prélevés à la même période ; chez P. viridis, la concentration en PbTx est restée supérieure à la limite réglementaire pour la consommation humaine pendant 16 semaine, alors qu'elle est revenue en dessous de ce seuil en 2 ½ semaines chez C. virginica.La composition biochimique des tissus et la reproduction n'ont pas parues affectées par ces évènements ; P. viridis réalise sa gamétogénèse durant toute l'année et a mis en place une stratégie de ponte intermittente partielle ; elle présentait durant toute l'année une grande stabilité de la concentration en composés de réserve. L'absence de cycle saisonnier marqué de la composition biochimique suggère que la ressource trophique est suffisante pour soutenir la gamétogenèse tout au long de l'année. Cependant, la première année du suivi, deux évènements majeurs de ponte et de recrutement ont été observés au printemps et à l'automne. Au cours de la deuxième année de suivi, l'analyse histologique montre que le même patron de ponte massive est observé au printemps ; cependant, à cette période, les efflorescences toxiques ont persisté et le recrutement a été inhibé, ce qui suggère que la fécondation et / ou le développement et la survie des larves […] / Worldwide, introductions of exotic species to new regions is of rising concern which can lead to catastrophic ecosystem alterations through competition with native species and disruption in energy flow.Perna viridis is a recently introduced bivalve species to US coastal waters and has vigorously spread throughout the southeastern US. However, little information regarding population structure and response to local environmental factors has been reported. Red tide blooms formed by the toxic dinoflagellate Karenia brevis are frequent along the Gulf coast of Florida and as a recently introduced species, it is unclear what tolerance P. viridis has toward these events and associated brevetoxins (PbTx). Further, as an invasive species ecological concerns have risen regarding potential for spread and competition with native bivalve species, particularly the eastern oyster Crassostrea virginica.This study aimed to characterize the population dynamics of established P. viridis populations and their response to naturally occurring K. brevis blooms. This was completed through monitoring of growth, mortality, juvenile recruitment, gametogenesis and biochemical composition (protein, glycogen and lipid) throughout a three year monitoring period to evaluate the effects of K. brevis blooms. Additionally, tissue PbTx concentrations were analyzed to determine uptake, accumulation and elimination rates. Data collected from the field and information reported in the literature were used to create a functional DEB model to predict individual growth and reproduction of P. viridis under environmentally realistic conditions.Prior to onset of the first K. brevis bloom event, P. viridis showed rapid growth rates (6 – 11 mm month-1) and high survival (mortality <1%). However, during K. brevis blooms growth rate dropped significantly and bioaccumulation of PbTx in the soft tissue was observed. High tissue PbTx concentrations persisted long after bloom dissipation and high rates of mortality ensued, severely reducing population densities. PbTx in mussels nearly doubled that of oysters sampled during the same time and remained above the regulatory limit for significantly longer, 2 ½ weeks and 16 weeks, respectively.Biochemical composition and reproduction appeared unaffected, exhibiting year round gametogenesis with a partial, intermittent spawning strategy and stability in reserves. A lack of significant seasonal cycles in biochemical composition suggests sufficient food and energy availability to support the observed year round gametogenesis. While continuous spawning capabilities were evident two major peaks in spawning and recruitment were observed (spring and fall), suggesting reduced fertilization and / or larval development and survival due to the presence of K. brevis and associated ichthyotoxins and hemolysins.These results indicate that while high tissue PbTx concentrations may lead to reduced growth in P. viridis, gametogenesis is not inhibited, allowing the population to survive K. brevis bloom exposure and reproduce, even while individual mortality was high. Prolonged bioconcentration of PbTx may lead to increased threat of post bloom trophic transfer, resulting in negative impacts on other important fisheries and higher food web implications. While it cannot be conclusively determined that the cause of reduced growth, survival and recruitment is due to red tide events, the parallels observed suggest that K. brevis is an important factor in the drastic changes in population structure.Through the work presented here, population dynamics of locally established P. viridis populations were characterized through monthly monitoring and the development of a DEB model to accurately predict the growth and reproduction under dynamic environmental conditions. This work aims to synthesize our knowledge on the individual bioenergetics of P. viridis and to aid in understand population dynamics and potential for competition with local C. virginica [...]

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Esta tese de doutorado apresenta um estudo sobre a utilizaÃÃo de dois bioprodutos, o primeiro a base de extrato lÃquido da palma forrageira gigante (Opuntia ficus indica) liofilizado e o segundo a Ãgua de coco em pà ACP-104, como diluente de sÃmen de curimatà comum (Prochilodus brevis). Este estudo foi motivado pela escassez de informaÃÃes sobre o sÃmen da espÃcie, dos bioprodutos testados e pela necessidade de desenvolver um protocolo de resfriamento e criopreservaÃÃo utilizando sÃmen de curimatà comum associados aos bioprodutos à base de palma forrageira e ACP-104. A tese està apresentada em trÃs capÃtulos. O primeiro capÃtulo trata de um artigo de revisÃo contendo as biotÃcnicas empregadas na conservaÃÃo de gametas. Nele relatam-se as tÃcnicas de resfriamento, congelaÃÃo e descongelaÃÃo de sÃmen e avaliaÃÃo morfolÃgica e computadorizada de espermatozoides de curimatà comum (P. brevis). O segundo capÃtulo objetiva a criopreservaÃÃo e anÃlise morfolÃgica dos espermatozoides de curimatà comum (P. brevis) diluÃdos em soluÃÃes a base de extrato de palma forrageira gigante (O. ficus) liofilizado, ACP (Ãgua de coco em pÃ) e soluÃÃo de glicose a 5%. Neste experimento foi utilizado o programa computacional CASA (Computer-Assisted Sperm Analyser) para analisar as propriedades de trajetÃria e velocidade dos espermatozoides para cada soluÃÃo estudada. Esta pesquisa teve como objetivo principal avaliar os efeitos da criopreservaÃÃo do sÃmen de curimatà comum (P.brevis), utilizando como diluente o extrato de palma forrageira gigante (O. ficus) liofilizado (EPFL). A metodologia empregada na criopreservaÃÃo do sÃmen de curimatÃ, utilizando os diluentes ELPF 30%; ELPF 50%, ACP-104 e Glicose 5%, permitiu a obtenÃÃo de taxas de motilidade pÃs-descongelamento superiores a 60%. O melhor meio de congelaÃÃo seminal de P. brevis, nas condiÃÃes testadas à o que utiliza a associaÃÃo do ACP-104 com o DMSO 10%. A metodologia empregada na criopreservaÃÃo do sÃmen de curimatà (P. brevis), utilizando os diluentes ELPF 30%; ELPF 50%, ACP-104 e Glicose a 5%, foram adequadas, permitindo a obtenÃÃo de taxas de motilidade pÃs-descongelamento superiores a 60%. Os resultados expressivos foram aqueles obtidos quando se utilizou a associaÃÃo do ACP-104 e DMSO 10%. Os demais tratamentos podem ser considerados num programa de reproduÃÃo assistida, jà que apresentaram desempenho dentro dos padrÃes de utilizaÃÃo de sÃmen criopreservados na espÃcie Prochilodus brevis. / This thesis presents a study on the use of two bioproducts, the first base of liquid extract of giant cactus pear (Opuntia ficus indica) lyophilized and the second the coconut powder ACP-104 as diluent semen common curimatà (Prochilodus brevis). This study was motivated by the scarcity of information about the semen of species of tested bioproducts and the need to develop a protocol for cooling and cryopreservation of semen using common curimatà associated with bioproducts based on cactus pear and ACP-104. The thesis is presented in three chapters. The first chapter is a review article containing biotechnologies employed in the preservation of gametes. Report him to the techniques of cooling, freezing and thawing of semen and morphological and computerized assessment of sperm of common curimatà (P. brevis). The second chapter aims to morphological analysis and cryopreservation of sperm of common curimatà (P. brevis) diluted in solutions based on extracts of giant cactus pear (O. ficus) lyophilized, ACP (coconut milk powder) and glucose solution 5%. In this experiment the computer program CASA (Computer-Assisted Sperm Analyser) was used to analyze the properties of trajectory and speed of sperm for each solution studied. This research aimed to evaluate the effects of cryopreservation of semen from common curimatà (P.brevis), using as diluent extract giant cactus pear (O. ficus) lyophilized (EPFL). The methodology used in sperm cryopreservation of curimatà using the diluents ELPF 30%; ELPF 50%, ACP-104 and 5% dextrose, afforded the rate of post-thaw motility higher than 60%. The best way of semen freezing P. brevis, the tested conditions is what uses the association of ACP-104 with 10% DMSO. The methodology used in sperm cryopreservation of curimatà (P. brevis) using diluents ELPF 30%; ELPF 50%, ACP-104 and 5% glucose were suitable, capable of producing rates higher post-thaw motility 60%. The significant results were those obtained when using the combination of ACP-104 and 10% DMSO. The other treatments may be considered an assisted reproductive program, as presented within the performance standards for the use of cryopreserved semen in species Prochilodus brevis.

Foot problems are not only the most common but in general also the most severe of the diabetic complications. The age group 15-50 yrs in this study was chosen because these patients were considered to be at their most active age and were felt to require optimal foot function. 380 patients (96 %) participated, 78 % with Type 1, 20 % Type 2 and 1 % with secondary diabetes mellitus (DM) and 100 healthy controls. Only six patients had signs of peripheral ischaemia but half of the patients had deformities such as fallen forefoot arches and hammer toes. With sensory thresholds and clinical signs it was demonstrated that age, duration of DM and tall stature are major risk factors for diabetic neuropathy. Gender differences depend on differences in height. Dorsiflexion of the toes against resistance was used to test the function and volume of m.extensor digitorum brevis. When compared with measurements of sensory thresholds for vibration, perception and pain, it was found to be a valuable test for screening of distal motor neuropathy. To prevent worsening of foot deformities 266 patients with Type 1 DM were followed for 3 years. Those with the most pronounced deformities were fitted with custom-made insoles and had repeated examinations. Improvement was more common in patients with insoles compared to patients without insoles. Bone mineral density (BMD) was measured in nine patients with osteopathy in their feet and 18 controls. BMD was lower in L2-L3, but not in the proximal femur, implying osteopenia being a possible risk factor for distal osteopathy. Plaster cast treatment was used in 33 diabetic patients with severe foot ulcers who were selected because previous conservative treatment had been unsuccessful and they had been judged unsuitable for vascular surgery. The lesions healed in 19 patients. In conclusion, the main findings demonstrate the need for an increased awareness of early preventive foot care in young and middle-aged diabetic patients. / <p>S. 1-46: sammanfattning, s. 47-120: 6 uppsatser</p> / digitalisering@umu

I have enjoyed this year, writing pieces that are special to me because they relate to experiences during 2008. I've written for orchestra, choir and an ensemble of xylophones and saxophone. Each piece has extended my skills and creativity in different ways from previous compositions. Prelude to the Unspoken This work is for symphony orchestra. Last year, it was rehearsed and recorded by the NZSO as part of the NZSO/Todd Young Composers Awards 2008. The pieces were recorded in the Michael Fowler Centre and conducted by Hamish McKeich. It was exciting to hear the piece come alive and watch the orchestra rehearse. Now I have heard the recording in a calmer state and know what it actually sounds like, I have been able to evaluate some decisions and whether or not they worked. As long as I have played instruments, I have played in orchestras. I can draw on these experiences when composing because as a clarinettist, you sit in the middle of the orchestra, and can hear the different sections playing and how their parts/notes relate to the rest of the orchestra. As a percussionist, hearing the orchestra from the back (when counting rests!) also reveals a different point of view. This year I chose to compose a slower, more contemplative piece. Last year, my compositions were dense and busy, so writing this piece required me to use space and texture in new ways. The title Prelude to the Unspoken alludes to something being stated but stopping before anything is revealed. A Schulwerk Orffering I was inspired to compose for the forces used in this piece because of an Orff- Schulwerk teacher training course I attended in 2008. As part of the Masters of Music degree, I completed a Level 1 workshop and on-line component - Orff Music Education-Theory and Practice 1, and more recently, completed the Level 2 workshop. Orff-Schulwerk education is a holistic, hands-on approach that explores music physically and through different instruments such as body percussion and approachable instruments (for children) such as recorders, mallet instruments and small percussion. One activity during the course was playing a tune from the Orff-Schulwerk volumes, where everyone was playing a mallet instrument - xylophone, marimba, glockenspiel, from soprano to bass, while the teacher improvised a tune on the recorder, over the top of this moving carpet of sound we were making with our ostinatos and drones. This was just like being in the middle of the orchestra. While playing my ostinato, I was in the centre of all of this sound, hearing how each simple ostinato made an interesting accompaniment. I was also influenced by Philip GIass' Fascades, where the cross rhythms of the accompaniment create a carpet of sound, while the simple saxophone melody floats over top. I wanted to create something similar with tenor saxophone and the educational xylophones. I chose to write for two alto and two bass xylophones (small, educational instruments with no chromatic notes). These instruments were available at the course and I was able to have these with me while I composed. Because I do not usually play a mallet instrument, I composed ostinatos that I was able to play. All the techniques are those explored in Orff-Schulwerk - ostinato, drone, sound carpet, imitation. The saxophone sits quite high in the first movement, holding long notes, while in the second movement, the saxophone is active with a wide range of notes. I recently had an item about this piece in the Orff New Zealand Aotearoa newsletter 'Sounding Orff'. I hope to get a recording/performance of this piece from a response to the newsletter. Missa Brevis I sing in the Hamilton Civic Choir and have sung many Masses so was interested in writing a Missa Brevis. The movements Kyrie, Gloria, Sanctus, Benedictus and Agnus Dei are for SATB with some movements scored for divisi voices. The style of this piece is approachable for many choirs because of traditional harmonic and musical organisation, while including modern arrangements of the text and approach to the music. Some choir members queried the fact that sometimes their part does not say a whole word, for example, just singing 'Dom', not 'Domine'. The words were deliberately set like this because when using block writing, as opposed to polyphony, I felt the extra syllables would change the desired musical and rhythmic texture. I wrote this piece with the Hamilton Civic Choir in mind because I know their capabilities. For example, I know the second basses can reach a low D. For the very low notes, I've added an octave option for the first basses or all basses if another choir cannot reach them. This recording by members of the choir was not up to the choir's usual standard because of time restrictions. The piano is used in my recording but is for rehearsal use only. The Gloria will be performed in the Choir's first 2009 concert in March.

Karenia brevis is the major harmful algal bloom-forming species in the Gulf of Mexico, and produces neurotoxins, known as brevetoxins, that cause large fish kills, neurotoxic shellfish poisoning, and human respiratory distress. Brevetoxins are polyethers that bind voltage-sensitive sodium channels, opening them for prolonged periods of time. Clonal cultures of K. brevis exhibit unique brevetoxin profiles, which not only differ from one another, but also change when subjected to different environmental conditions. The brevetoxin structures were elucidated 30 years ago without any breakthroughs for the biosynthetic pathway. These unique ladder-like polyethers have 10 (PbTx-1) or 11 (PbTx-2) rings, indicating that they are synthesized as secondary metabolites by polyketide synthases. The extensive size of the genome and the lack of histones and nucleosomes combined with the additional regulatory step of a trans-splicing spliced leader sequence make normal molecular techniques ineffective in determining the genes involved in toxin synthesis. The goal of this project is to identify a potential link between toxin, gene, and function. One objective is to take the next step towards identifying the genes associated with the synthesis and regulation of brevetoxins and to help elucidate the hypothesized gene clusters of multi-protein enzymatic complexes involved in brevetoxin production, one for each backbone. The second objective is to make an effort to determine the in vivo function of the costly brevetoxins by identifying possible ion channels, which could be osmotically regulated by the toxins. Genes for polyketide synthases (PKS) were identified in K. brevis, obtained from Expressed Sequence Tag (EST) libraries. In this work, reverse transcription polymerase chain reactions (RT-PCR) were used to generate pools of complementary DNA (cDNA), which was used in real-time quantitative polymerase chain reactions (qPCR) to give relative amounts of PKS transcripts. K. brevis clones have shown a significant increase in toxin production after a rapid shift from high salinity to low salinity, indicating a regulation of brevetoxin synthesis. To gain a better understanding of regulation of toxin production during algal blooms, we compared the toxin levels under different conditions to the transcript levels of PKS genes, as determined by quantitative RT-PCR. In a separate line of investigation, an in silico analysis of the EST library was performed to identify ion channel genes expressed by K. brevis, which may be the in vivo binding site of brevetoxin. The information generated from this project will help to elucidate the effects of environmental variations on toxin production and the biological function of toxin production -- valuable information for the shellfish industries and public health.

Laser in situ scattering and transmissometry (LISST) instruments are used to measure the particle size distributions (PSDs) and volume concentration of individual and groups of phytoplankton in water. The objective of this research was to test the LISST’s ability in detecting monospecific blooms in-situ and the ability to detect aggregation after diatoms were subjected to different temperatures and bacteria concentrations. The PSDs of ten harmful algal bloom (HAB) species were measured with the LISST characterizing the peak location, peak height, peak width, and peak range resulting in a scattering signature for each species. Each species had specific characteristics that would allow for their detection with the LISST, though microscope observations would be needed for complete accuracy. The LISST was able to detect HABs placed in natural seawater collected off the Texas coast. Blooms of four HAB species before they reached full” bloom concentrations were detected making the LISST a possible low cost, effective tool in the early detection and monitoring of HABs. The diatom, Odontella aurita, was used to test how well the LISST could monitor aggregation, an important process in the termination of many phytoplankton blooms. Increasing temperature causes an increase in transparent exopolymer particle (TEP) production in diatoms, which is a critical sticky particle that increases the probability of aggregation. An increase in temperature can also cause an increase in bacteria concentration that can positively effect TEP production and thus aggregation. O. aurita was grown at 20 °C and 28 °C and showed a significant increase in TEP abundance with temperature (p = 0.002), though no relationship between TEP production and bacteria concentration existed. Coomassie stained particles (CSP) are proteinaceous gel-like particles, which are currently understudied. CSP was consistently produced though it did not appear to be dependent upon any single factor. The increase in ocean temperatures has implications for an increase in phytoplankton blooms making the monitoring and understanding of these blooms even more important as they can affect the carbon cycle and potentially the microbial loop.

Thesis (M.S.)--University of North Carolina at Wilmington, 2003. / Includes bibliographical references (leaves : [88]-96).

Polyether compounds are a subgroup of natural products with regular occurrence of multiple C-O-C motifs. The biosynthetic origin of polycylic polethers has been studied and the majority of them are derived from polyketide or terpene pathways. Normally, the polycyclic polyethers can be divided into two groups based on their structural features: the first group features multiple rings that are interconnected by carbon-carbon single bond, which are produced by a biosynthetic cascade of exo epoxide-opening reactions; the other group has multiple fused cyclic ethers and are formed by an cascade of endo epoxide-opening reactions. Karenia brevis (K. brevis) is known as principle harmful bloom (HAB) organism of the Gulf of Mexico which can cause red tides. Brevetoxins (PbTx) are a suit of cyclic polyether ladder compounds produced by K. brevis. Brevetoxins are neurotoxins that can bind to voltage-gated sodium channels in nerve and muscle cells, resulting in disruption of normal neurological processes causing the human illness which is clinically described as neurotoxic shellfish poisoning (NSP). Inspired by Cane-Celmer-Wesley’s proposal regarding monensin biosynthesis, Nakanishi and Shimizu proposed a biosynthetic pathway for brevetoxin which suggests that PKS-mediated synthesis of the polyene is followed by epoxidation to afford a polyepoxide which then undergoes an epoxide-opening cascade, catalyzed by an epoxide hydrolase (EH). To find evidence to support the hypothesis that an epoxide hydrolase from polyether ladder producing dinoflagellates will catalyze the construction of the polyether ladder framework from polyepoxide substrates, and to study the role of epoxide hydrolase in the biosynthesis of polyether ladder compounds, it is necessary to identify and produce one or more epoxide hydrolase from dinoflagellates. The methods to detect epoxide hydrolase activity in K. brevis and different techniques to obtain epoxide hydrolases from K. brevis are discussed. A microsomal EH identified from a K. brevis EST library was cloned and expressed. The characterization of this EH, including substrate selectivity and enantioselectivity as well as its potential to catalyze the critical ento-tet cyclization epoxy alcohol, is discussed.

Many clinicians believe exercise associated muscle cramps (EAMC) occur because of dehydration and electrolyte losses. Experimental research supporting this theory is lacking. Mild hypohydration (3% body mass loss) does not alter cramp threshold frequency (TF), a measure of cramp susceptibility, when fatigue and exercise intensity are controlled. No experimental research has examined TF following significant (3-5% body mass loss) or serious hypohydration (>5% body mass loss). TF and blood variables of ten subjects were measured pre-post exercise. Subjects exercised in an environmental heat chamber alternating between upper arm ergometry and non-dominant leg cycling every 15 minutes until they lost 5% of their body mass or were too exhausted to continue. Significant (n=5) or serious hypohydration (n=5) did not alter cramp TF, cramp intensity, or cramp EMG amplitude. Significant and serious hypohydration with moderate electrolyte losses does not alter cramp susceptibility when fatigue and exercise intensity are controlled.

No description available.