Title: Physiological responses on standardized climbing task in sport climbers Purpose: To determine the effect of height, wall angle, climbing speed and climbing ability on physiological responses in sport climbers. Methods: The study was divided into three parts. 75 sport climbers (36 female and 39 male) completed differing tests on climbing wall and motorized climbing ergometer. Perceived exertion was assessed on a scale suggested by Borg. Indirect calorimetry, venous blood samples and near-infrared spectroscopy were used to assess physiological response, hormonal response and muscle oxygen saturation, respectively. Results: Perceived exertions were higher when climbing to height as opposes to climbing low to the ground on the treadwall (+5,3%; P = 0,013; ηp 2 = 0,149) (Study 1A). The physiological response was higher on the climbing wall as opposed to the treadwall: V̇ O2 (+6%; P = 0,03; ηp 2 = 0,22), SF (+4%; P = 0,04; ηp 2 = 0,20), V̇ E (+9%; P = 0,01; ηp 2 = 0,30) a EC (+16%; P < 0,001; ηp 2 = 0,48). There was an interaction for climbing ability and post- climbing catecholamine concentration (P < 0,01, ηp 2 = 0,28) (Study 1B). With increasing climbing speed greater differences were found for V̇ O2 (P < 0,001, ηp 2 = 0,923) than for StO2 (P < 0,001, ηp 2 = 0,448). Between-subject effect...

Measles immunization coverage in Namibia has not yet reached the WHO target of 90% in all provinces and districts, particularly in Luderitz district. The study aimed to determine the factors associated with the uptake of measles immunization among children in Luderitz district. A quantitative cross-sectional study was conducted among 150 parents/caregivers and their children who visited Luderitz clinic during July 2019 to August 2019. A developed questionnaire collected data on the several factors including child-related ,health service related and the perception of parents/caregivers. Data was analysed using STATA 14. Measles immunization uptake was 61% and significantly associated with child’s age (p=0.001) and gender (p=0.003), parents/caregivers age (p≤0.0001), gender (p=0.021), marital status (p≤0.0001) and employment status (p=0.009). Barriers to measles immunization were mainly inconvenient vaccination time (44%) and forgetfulness (25%) while suggested cues to action, were sending the reminders (30%), providing immunization the whole day (40%) and health education and promotion. / Health Studies / M.A. (Nursing Science)

AbstractUnderwater sports such as artistic swimming and freediving, are characterized by periods of voluntary arrest of breathing, known as apnoea, while exercising. It is well known that apnoea leads to bradycardia and some other oxygen conserving responses, but little is known when exercise is conducted underwater, and the differences between exercise with intermittent and maximal apnoea periods. This review aims to understand and compare the physiological responses of the exercise performed underwater and the effect of the diving reflex in the heart rate, blood lactate, arterial pressure, arterial oxygen saturation and oxygen uptake, in different types of apnoea. A systematic review was conducted, searching studies in five scientific databases, according to specific criteria. 14 articles were selected for the analysis, using the method called PRISMA with systematic research, including just articles where trials were performed underwater. Artistic swimming and depth modalities of freediving are perceived as high intensity exercise. Blood lactate concentration (BLa), heart rate peak (HRpeak) and mean arterial pressure (MAP), depend more on exercise intensity, whereas arterial oxygen saturation (SaO2) and minimum heart rate (HRmin) is more related to apnoea duration. The diving response is more pronounced in freediving depth modalities due to impossibility of breathing. High intensity exercise mildly counteracts the diving reflex due to muscular and oxygen demands. Further investigation is needed in underwater sports, and physiological measurements should be performed according to a general consensus among researchers in order to avoid wide ranges of values in trial outcomes.

Les chélates de Gd sont largement utilisés en tant qu’agents de contraste en imagerie par résonance magnétique. En 2015, un lien a été établi entre l’observation d’hypersignaux T1 de certaines structures cérébrales et le nombre d’administrations préalables de ces chélates de Gd reçues par les patients. Cette observation fortuite pose la question de la tolérance à long-terme de ces molécules. L’ion Gd³⁺ ayant un rayon ionique très proche de celui du Ca²⁺, il interfère avec de nombreux processus biologiques Ca²⁺-dépendants. Sa chélation par un ligand améliore considérablement sa tolérance. Les chélates de Gd sont répartis en 2 classes : macrocycliques et linéaires, différant par leur stabilité thermodynamique et donc leur tendance à se dissocier. Il est classiquement admis que les chélates de Gd ne traversent pas la barrière hémato-encéphalique saine. L’observation de ces hypersignaux au niveau du noyau dentelé du cervelet, du globus pallidus et parfois d’autres structures, remet en cause ce postulat.Les travaux de cette thèse visent à étudier le mécanisme d’accumulation du Gd dans le système nerveux central (voies de passage, localisations, spéciation du Gd accumulé). Les potentiels effets neurotoxiques associés à la présence de Gd dans le cerveau ont aussi été recherchés.Nous avons mis en évidence chez le Rat que l’accumulation cérébrale est d’autant plus importante que la stabilité thermodynamique du chélate de Gd est faible, confirmant les observations cliniques. Les hypersignaux T1 sont en effet liés à des injections répétées de chélates linéaires de Gd. Nous avons aussi établi qu’une insuffisance rénale modérée potentialise la capture cérébrale de Gd dans le cas d’un chélate de Gd linéaire. Nous avons observé que les structures cérébrales accumulent d’autant plus de Gd qu’elles sont riches en fer endogène. Une augmentation de la zincurie, après administration de chélates de Gd linéaires, a également été observée, suggérant un phénomène de transmétallation.La combinaison des techniques de fluorescence X (XRF), de microscopie électronique en transmission (TEM) et du NanoSIMS, a permis l’observation des dépôts de Gd à différentes échelles et sous différentes formes. Cela a permis de documenter les voies de passage du Gd, le rôle des métaux endogènes et du phosphore. L’analyse XRF a permis d’observer qu’au sein des noyaux cérébelleux profonds du Rat, la majorité du Gd est accumulée sous la forme de structures allongées et ramifiées. Ces structures pourraient être des vaisseaux sanguins. Le Gd serait accumulé dans l’espace périvasculaire. En TEM, des dépôts insolubles de Gd ont été observés dans les lames basales de vaisseaux, dans l’interstitium cérébelleux, et dans l’espace périvasculaire. Ces dépôts à l’apparence épineuse sont riches en phosphore, suggérant des dépôts de GdPO₄. Du Gd et du phosphore ont également été identifiés dans des cellules gliales, au sein de pigments intracellulaires de lipofuscine. Aucun dépôt de Gd n’a été trouvé chez des rats traités par un chélate de Gd macrocyclique.L’hypothèse mécanistique établie consiste en l’accès précoce des chélates de Gd au liquide céphalo-rachidien (LCR), puis leur diffusion passive dans le parenchyme proche des ventricules cérébraux, à travers l’épendyme. Arrivés dans des zones riches en métaux endogènes et/ou en phosphore, leschélates de Gd les moins stables thermodynamiquement se dissocieraient, le Gd se liant à des macromolécules endogènes, ou précipitant. La circulation du LCR le long des artérioles pénétrantes piègerait également du Gd au niveau périvasculaire. Les chélates de Gd intacts seraient éliminés par le système glymphatique périvasculaire ou « drainage périartériel intrapariétal ». On retrouve aussi du Gd probablement dissocié à ce niveau.Hormis une hypoactivité, non spécifique, les études neurocomportementales, histopathologiques et neurochimiques menées chez le Rat n’ont pas permis de mettre en évidence une toxicité avérée, même à des doses élevées. / Gd chelates are widely used as contrast agents in magnetic resonance imaging. In 2015, the finding of T1 hyperintensities in brain structures was associated with the prior administrations of these agents in patients. This observation raised the question of the long-term tolerance of these molecules. The Gd³⁺ ionic radius is very close to that of Ca²⁺, and therefore this lanthanide interferes with numerous Ca²⁺-dependent biological processes. Its chelation by a ligand considerably improves its tolerance. Gd chelates are categorized into 2 classes: macrocylic and linear agents, differing in their thermodynamic stabilities, and therefore in their ability to dissociate. It is classically admitted that Gd chelates do not cross the healthy blood-brain-barrier. The observation of these hyperintensities, in the dentate nucleus of the cerebellum, the globus pallidus, and sometimes other structures, questioned this assumption.This thesis aimed to study the mechanism of Gd accumulation in the central nervous system: access pathways, tissue and subcellular location, Gd speciation). Potential neuro-toxicological effects associated with long term Gd presence in the brain were also researched.Using a rat model, we evidenced that the lower the thermodynamic stability of Gd chelates, the greater the cerebral Gd concertation was, thus confirming clinical observations. T1 hyperintensities exclusively appeared following administrations of linear Gd chelates. We also established that moderate renal failure potentiates Gd brain uptake in the case of linear Gd chelate. We also observed that brain structures accumulate even more Gd that their endogenous Fe concentration is high. Administration of linear Gd chelates resulted in an increased zincuria. Gadolinium vs. Zn transmetalation may be responsible for this effect.The combination of X fluorescence, transmission electronic microscopy, and NanoSIMS, showed Gd deposits at various scales and in various forms. It allowed us to document Gd pathways, and the role of endogenous metals and phosphorus in this phenomenon. X fluorescence analysis depicted, in rat deep cerebellar nuclei, that the majority of Gd was accumulated in the form of elongated and ramified structures, believed to be blood vessels where Gd would be retained in the perivascular area. By means of electron microscopy in rats, Gd insoluble deposits were observed in basal lamina of vessels, in cerebellar interstitium, and in the perivascular space. These Gd deposits, of spiny aspect, were rich in phosphorus, thus suggesting the presence of GdPO₄. Co-presence of Gd and phosphorous was also identified into glial cells, accumulated in intracellular lipofuscine pigments. No Gd deposits were found in rats treated with a macrocyclic Gd chelate.The established mechanistic hypothesis consists in the early access of Gd chelates to cerebrospinal fluid, followed by their passive diffusion into the parenchyma close to cerebral ventricles, through the ependyma. Encountering areas rich in endogenous metals and/or phosphorus, the less thermodynamically stable Gd chelates would dissociate, and Gd would bind endogenous macromolecules, or precipitate. Cerebrospinal fluid circulation along penetrating arterioles would also trap Gd at the perivascular level. Intact Gd chelates would be eliminated through perivascular glymphatic pathway, or “intramural periarterial drainage”, where probably dissociated Gd is also found.Except a non-specific hypoactivity, neurobehavioural, histopathological and neurochemical studies performed in rats did not demonstrate any obvious neurotoxicity, even at high doses.

1,25-dihydroxyvitamin D3 [1,25(0H)2D3] has been shown to promote phosphate transport rapidly in the perfused duodenal loop, relative to controls, reaching treated/av basal at T = 40 min = 1.82 ± 0.42 and 1.11 ± 0.21, respectively. By using isolated chick enterocytes, studies were undertaken to determine whether 1,25(0H)2D3 has a direct effect on isolated intestinal cells that is manifested by either enhanced uptake or extrusion of phosphate. In time course studies, with 4- to 8-wk-old chicks, 32P uptake in enterocytes at 10 min after addition of test substance was 0%, 130%, 151%, and 123% of controls for 10 pM, 50 pM, 130 pM, and 300 pM 1,25(0H)2D3, respectively. The metabolite 24,25- dihydroxyvitamin D3 [24,25(0H)2D3] exerted an inhibitory effect on phosphate uptake by 1,25(0H)2D3 at a concentration of 130 pM. This result was in agreement with perfusion studies and supports the physiological relevance of isolated cell studies. For signal transduction studies, isolated enterocytes were incubated with 20 µM forskolin (an activator of protein kinase A), 100 nM phorbol ester (an activator of protein kinase C), or 2 µM BAY K 8644 (a calcium channel activator). Enhanced 32P levels relative to controls were found for phorbol ester (126% of controls at T = 7 min, P < 0.05) and BAY K 8644 (150% of controls at T = 7 min, P < 0.05) but not for forskolin, suggesting involvement of protein kinase C and calcium channel signal transduction pathways in uptake. These results paralleled those observed for the perfused duodenal loop. For aging studies, white leghorn roosters were raised for 7, 14, and 28 wk prior to experiments. These studies showed a 1,25(0H)2D3-mediated increase in 32P uptake in isolated cells at 7 wk, but not at 14 or 28 wk. Further analysis of isolated basal lateral membrane (BLM) on SDS-PAGE followed by Western analysis with a well characterized antibody (Ab099) showed a decreased expression of the putative membrane receptor for 1,25(0H)2D3 with increasing age, paralleling the results obtained for 32P uptake in isolated intestinal cell studies. Analyses of 1,25(0H)2D3 effect on protein kinase C activity likewise revealed hormone-mediated stimulation in cells from 7-wk- old chicks, with decreasing responsiveness at a later age. The combined results indicate a physiologically important role for 1,25(0H)2D3 membrane-initiated phosphate uptake in enterocytes of young, rapidly growing animals. Furthermore, these studies validate the use of isolated intestinal cells for further studies on ribozyme-mediated ablation of the 1,25(0H)2D3 membrane receptor function.

Recent debates about decolonising research suggest that researchers should reframe how they think of research participants in the Global South: not as data points, but as partners who are involved from research design to dissemination. However, the findings of development research are rarely shared with participants or other non-decision-maker audiences in the Global South.This study explores the structural factors that have led a research funder, the UK Foreign and Commonwealth Development Office (FCDO) (formerly Department for International Development (DFID)), to focus its research communication efforts almost exclusively on policy audiences, and how this has shifted in the years since DFID was first established in 1997.

Bakgrund: Strålningen från radioaktiva ämnen utnyttjas för både diagnostik och terapi av olika typer av sjukdomar. För att kunna genomföra en nuklearmedicinsk undersökning krävs ett radiofarmaka och nästan all administrering sker genom en perifer venkateter (PVK). En del PVK är utrustade med slang och dessa skall helst undvikas. Forskning har visat att en del av aktiviteten kan fastna i PVK vid administrering av radiofarmaka. Syftet med denna studie är att undersöka om aktivitetsupptaget av de mest använda radioaktiva farmaka skiljer sig mellan BD Nexiva™ och i BD Venflon™ Pro Safety. Även den optimala volymen NaCl för genomspolning av PVK efter injektion av radiofarmaka kommer att studeras. Metod: En beräknad mängd aktivitet drogs upp. Aktiviteten i plastsprutan mättes före samt efter injektion via PVK. Därefter mättes PVK efter injektion av radiofarmaka utan genomspolning av NaCl samt efter genomspolning med 3 ml, 5 ml, 10 ml, 20 ml samt 30 ml NaCl. Resultat: Det erhållna resultatet för de två olika PVK visade att efter sköljning av NaCl minskade residual aktiviteten för samtliga radiofarmaka. Det radiofarmaka som hade mest residual aktivitet i båda PVK var 99mTc-Myoview. Konklusion: Det finns ingen skillnad mellan Nexiva™ och Venflon™. Dock måste det tas hänsyn till att BD Nexiva™ har en plastslang som inte är strålskyddad. Den mest gynnsamma mängden för genomspolning i PVK bestämdes till 10 ml. / Background: The radiation from radioactive substances is used for diagnostic and therapy of various diseases. It requires a radiopharmaceutical to perform a nuclear medicine examination. Most of the radiopharmaceuticals are administrated through a peripheral venous catheter (PVC). There is a few PVC that is equipped with a plastic tube, which should be avoided. Research has shown that the activity from the radiopharmaceuticals can adsorb in the PVC during the administration. The aim of this study is to examine if the activity uptake of the most commonly used radiopharmaceuticals are different between BD Nexiva ™ and BD Venflon™ Pro Safety. The optimal volume of sodium chloride for flushing in the PVC after an injection of the radiopharmaceutical will also be studied. Method: The amount of activity that was used for this study was estimated. The activity in the plastic syringe was measured before and after the injection through the PVC. Then the PVC was measured after injection of radiopharmaceutical, both with and without the flushing of sodium chloride. First with 3 ml and then 5 ml, 10 ml, 20 ml and 30 ml of sodium chloride. Results: The obtained result for the two different PVC, BD Nexiva ™ and BD Venflon, showed that after rinsing with sodium chloride the residual activity of all radiopharmaceuticals decreased. The radiopharmaceuticals that held the most residual activity in both PVC were 99mTc-Myoview. Conclusion: This study showed that there is no difference between Nexiva™ and Venflon™. However it must be taken into consideration that BD Nexiva™ has a plastic tube that is not shielded from radiation. The optimal volume of sodium chloride for flushing was determined to 10 ml.

No description available.

Peer reviewed literature was searched to identify research pertaining to the uptake of heavy metals (As, Cd, Pb and Zn) by vegetables (cabbage, carrot, lettuce, and radish). The objectives of this research were to 1) determine the relationship between heavy metal concentrations in the soil and heavy metal concentrations in vegetables, and 2) determine the level of risk associated with exposure to heavy metals through ingestion of contaminated vegetables. Highly variable estimates and biologically implausible regression equations resulted from this meta-analysis. Exposure to arsenic through the ingestion of lettuce grown on contaminated soil significantly increases cancer risk, especially in children. Highly variable hazard quotients prevent strong statements concerning toxic effects from exposure to Pb, Cd, or Zn. A more in-depth meta-analysis (multiple-regression and nonlinear curve-fitting) and an upgrade in data reporting standards are recommended.

Proton channels are essential for many of the processes of life. The influenza A viral protein M2 is responsible for sensing the conditions necessary for viral RNA release. The proton-translocating FoF1 ATPase (ATP synthase) uses a proton gradient to drive adenosine triphosphate (ATP) synthesis. We have directly measured proton uptake in vesicles containing reconstituted M2 or FO by monitoring external pH after addition of valinomycin to vesicles with 100-fold diluted external [K+]. This proton flux assay was utilized to quantify proton flux through single M2 and Fo channels. Contrary to previous reports, proton uptake by M2 was not significantly altered by acidification of the extravesicular pH. We conclude that pH only weakly affects proton flux through M2 in the pH range of 5.4 - 7.0. Theoretical analysis utilized for such vesicle uptake assays illuminates the appropriate time scale of the initial slope and an important limitation that must be placed on inferences about channel ion selectivity. The rise in pH over 10 seconds after ionophore addition yielded time-averaged single channel conductances of 0.35±0.2 aS and 0.72±0.4 aS at pH 5.4 and 7.0 respectively. Such a low time-average conductance implies that M2 is only conductive 10^-6 to 10^-4 of the time. M2 selectivity for hydrogen over potassium is ~10^7. Fo translocates protons across membranes, converting electrochemical energy to rotational inertia. Previous experiments have been partially confounded by a contaminating channel, CL, which co-purifies with Fo and leaks cations. CL activity is shown to not decrease following deletion of the previously uncharacterized yraM open reading frame of E. coli. Fo purified from a deletion strain lacking yraM is just as active as Fo purified from the wild-type strain. Using Fo from the deletion strain, the single-hit hypothesis of DCCD inhibition of passive proton flux through Fo was examined. A DCCD-induced reduction in ATP synthase activity correlates with a reduction in the total initial slope, the number of functional Fo per µg protein, and the single channel proton flux. At least 2 DCCD per Fo are required to totally inactivate passive proton flux. M2 and Fo have similar single channel conductances but different open probabilities.