145,816 research outputs found
L’Atelier de Francis Bacon : 7, Reece Mews
No full textCet ouvrage résulte du don de la maison-atelier du peintre Francis Bacon (1909-1992), à l’origine située dans le quartier londonien de South Kensington, à la Hugh Lane Municipal Gallery of Modern Art de Dublin (Irlande). Avant le déménagement de l’espace, le musée a confié au photographe Perry Ogden la mission de documenter in situ ce lieu historique, reconstruit par la suite à Dublin. 7 Reece Mews se compose avant tout d’une suite de clichés photographiques en couleurs, ordonnant un parcours..
Optimising the AMF Reece sewing machines for automatic hand-stitching
No full textkatedra: KKV; přílohy: 14 prospektů, 1 dvd, 2 jehly; rozsah: 63The bachelor´ s thesis solved the problems of a machine-made hand stitch, which has become an integral part of industrial textile production. A broad area of the hand stitch application still remains at the finishing confection operations, repair operations, and adjustment of confection products. The bachelor´ s thesis is based on information obtained from literature, Internet, and personal knowledge when working with sewing machines, especially those made by the AMF Reece company. To achieve the objective of the bachelor´ s thesis, it was necessary to explain the history of the machine-made hand stitch, and to analyze the sewing technology offered on the market at the moment. The main objective of the bachelor´ s thesis consisted in labor-saving modifications of the AMF Reece sewing machine for machine-made hand stitch.Bakalářská práce řešila problematiku strojové tvorby ručního stehu, který se stal nedílnou součástí průmyslové textilní výroby. Velká oblast využití ručního stehu nadále zůstává při dokončovacích konfekčních pracích, při opravách a úpravě konfekčních výrobků. Bakalářská práce vycházela z informací, které byly získány z literatury, internetu a osobních poznatků při práci s šicími stroji především od firmy AMF Reece. Pro dosažení cíle bakalářské práce bylo nezbytné objasnit historii strojové tvorby ručního stehu a analyzovat šicí techniku aktuálně nabízenou na trhu. Hlavním cílem bakalářské práce byly racionalizační úpravy šicího stroje pro tvorbu ručního stehu firmy AMF Reece
Sex ratios in the rodent malaria parasite, Plasmodium chabaudi
No full textThe sex ratios of malaria and related Apicomplexan parasites play a major role in transmission success. Here, we address 2 fundamental issues in the sex ratios of the rodent malaria parasite, Plasmodium chabaudi. First we test the accuracy of empirical methods for estimating sex ratios in malaria parasites, and show that sex ratios made with standard thin smears may overestimate the proportion of female gametocytes. Secondly, we test whether the mortality rate differs between male and female gametocytes, as assumed by sex ratio theory. Conventional application of sex ratio theory to malaria parasites assumes that the primary sex ratio can be accurately determined from mature gametocytes circulating in the peripheral circulation. We stopped gametocyte production with chloroquine in order to study a cohort of gametocytes in vitro. The mortality rate was significantly higher for female gametocytes, with an average half-life of 8 h for female gametocytes and 16 h for male gametocytes.</p
<i>No se sabe</i>: entrevista a Lucas Gagliardi
No full textEntrevista al Licenciado y Profesor en Letras (UNLP) Lucas Gagliardi. Se especializa en literatura en lengua inglesa y en crítica genética. Se desempeña como profesor en la Universidad Pedagógica (UNIPE), en institutos de formación docente y escuelas secundarias. Ha participado en proyectos de investigación sobre archivos de escritores, publicaciones impresas. Participa en el programa de voluntariado universitario de la Facultad de Trabajo Social (UNLP) en articulación con la Biblioteca Ambulante del Hospital de Niños dictando talleres de lectura y escritura.Al hacer clic en el enlace que figura en "Documentos relacionados", pueden accederse a todos los trabajos de Lucas Gagliardi presentes en el repositorio.Radio Universidad Nacional de La Plat
<i>No se sabe</i>: entrevista a Laura Sombra del Río
No full textEntrevista a la profesora de Matemática Laura Sombra del Río, integrante del Instituto de Metodología Alternativa para la Enseñanza de la Ciencia (IMApEC). Se especializa en tecnología informática aplicada a la educación, especialmente de las ciencias duras como la matemática.Al hacer clic en el enlace que figura en "Documentos relacionados", pueden accederse a todos los trabajos de Laura Sombra del Río presentes en el repositorio.Facultad de Ingenierí
The evolutionary ecology of daily rhythms in malaria parasites
No full textCircadian rhythms are (approximately) 24-hour oscillations in biological processes such as gene expression, physiology, and behaviour, which allow organisms to schedule their activities around the predictable environmental changes caused by the Earth’s daily rotation. Being in tune with the environment confers an adaptive advantage to organisms across diverse taxa. Moreover, daily rhythms are important for interactions between hosts and pathogens, and shape infection dynamics in a variety of natural systems.
Daily rhythms are a hallmark of malaria infections, in which single-celled Plasmodium parasites replicate in vertebrate hosts’ blood by cyclically invading red blood cells (RBCs), multiplying, and eventual RBC bursting. This bursting often occurs synchronously, at 24- 48- or 72-hour intervals, depending on the parasite species. Asexual parasites progress through this intra-erythrocytic developmental cycle (IDC) as three consecutive developmental stages (ring, trophozoite, schizont), and in each IDC a small but variable proportion of parasites form sexual transmission stages (gametocytes), which are infectious to the mosquito vector.
The IDC is responsible for many of the disease symptoms in malaria and asexual replication fuels transmission potential by boosting parasite density in the blood. The timing of RBC bursting is set by the host’s feeding-fasting rhythm – parasites burst during hosts’ feeding time – but this coordination can be misaligned. When parasites are misaligned with the host’s rhythm, they experience fitness costs, which suggests IDC rhythms are important to parasites and may be a target for intervention. Moreover, synchrony in replication varies between and within infections, and some Plasmodium species replicate asynchronously but the selective pressures that lead to the evolution of different replication rhythms, and the costs and benefits of (un)coordinated replication are unclear. In my thesis, I use an evolutionary-ecological framework to investigate the costs and benefits of synchrony, and how daily rhythms in replication and alignment with host rhythms interact with virulence and drug efficacy in a murine model system using the synchronous species Plasmodium chabaudi.
In Chapter 1, I ask if synchronous replication is costly or beneficial for parasites and hosts, and if this is dependent on host daily rhythms. I compare parasite fitness proxies in synchronous and asynchronous infections in rhythmic and arrhythmic hosts, and the impacts on host health. I show that, surprisingly, asynchronous development in the blood could be advantageous to parasites, as gametocytes are more abundant in asynchronous infections. Harbouring synchronous infections takes moderately higher toll on hosts’ health, disproportionately lowering blood glucose concentration and disrupting body temperature more severely than asynchronous infections. My findings also indicate that infecting rhythmic hosts confers both costs and benefits to parasites, in the form of lower asexual but higher sexual parasite densities. Additionally, host rhythmicity phenotype has conflicting consequences for the hosts themselves, as rhythmic hosts lose less of their blood glucose but more of their RBCs, and their locomotor rhythms are more disrupted than for arrhythmic hosts.
In Chapter 2, inspired by previous research that suggests more virulent parasites cope better with a variety of challenges in the within-host environment, I investigate whether virulent genotypes are less affected by host-parasite temporal misalignment than avirulent genotypes. I also test the prediction that virulent parasites, which reach a high density and deplete more host RBCs, exhibit dampened synchrony to avoid costs of crowding. I compare two genetically related parasite clones – one significantly more virulent than the other – in infections aligned or misaligned to host rhythms. My results demonstrate that virulent parasites are indeed less synchronous and have the potential to recover more rapidly from misalignment compared to their avirulent counterparts. This warns that virulent genotypes could compensate more readily against any future intervention strategies aimed at disrupting parasite rhythms.
Lastly, in Chapter 3 I focus on how the IDC rhythm affects drug-based interventions. I examine drug efficacy of the front-line antimalarial artemisinin when treating younger (rings) versus older parasite stages (trophozoites). To separate the potential impacts of IDC stage and host time of day, I treat each parasite stage at several different times of day – in aligned and misaligned infections. I find that trophozoites are more sensitive to artemisinin than rings and that although host rhythms per se do not have a direct effect, uncoupling host and parasite rhythms exacerbates the stage-specificity in drug efficacy. These data reveal that parasite sensitivity to drugs may be enhanced (for trophozoites) or attenuated (for rings) by perturbing the IDC’s timing in relation to the host.
The research in my thesis helps identify novel ways to target malaria parasites, demonstrates how they might recover from perturbations and more broadly, contributes to growing efforts to determine how rhythmicity impacts infection dynamics, disease severity, intervention success and evolutionary trajectories in host-parasite interactions
The meaning of death : evolution and ecology of apoptosis in protozoan parasites
No full textThis work was funded by the Wellcome Trust (SER: WT082234MA; http://www.wellcome.ac.uk/), the NERC (LCP: studentship), the Royal Society of London (AG: University Research Fellowship; http://royalsociety.org/), and Balliol College, University of Oxford (AG; http://www.balliol.ox.ac.uk/).The discovery that an apoptosis-like, programmed cell death (PCD) occurs in a broad range of protozoan parasites offers novel therapeutic tools to treat some of the most serious infectious diseases of humans, companion animals, wildlife, and livestock. Whilst apoptosis is an essential part of normal development, maintenance, and defence in multicellular organisms, its occurrence in unicellular parasites appears counter-intuitive and has proved highly controversial: according to the Darwinian notion of "survival of the fittest", parasites are expected to evolve strategies to maximise their proliferation, not death. The prevailing, and untested, opinion in the literature is that parasites employ apoptosis to "altruistically" self-regulate the intensity of infection in the host/vector. However, evolutionary theory tells us that at most, this can only be part of the explanation, and other non-mutually exclusive hypotheses must also be tested. Here, we explain the evolutionary concepts that can explain apoptosis in unicellular parasites, highlight the key questions, and outline the approaches required to resolve the controversy over whether parasites "commit suicide". We highlight the need for integration of proximate and functional approaches into an evolutionary framework to understand apoptosis in unicellular parasites. Understanding how, when, and why parasites employ apoptosis is central to targeting this process with interventions that are sustainable in the face of parasite evolution.Peer reviewe
Evolution of apoptosis-like programmed cell death in unicellular protozoan parasites
No full textApoptosis-like programmed cell death (PCD) has recently been described in multiple taxa of unicellular protists, including the protozoan parasites Plasmodium, Trypanosoma and Leishmania. Apoptosis-like PCD in protozoan parasites shares a number of morphological features with programmed cell death in multicellular organisms. However, both the evolutionary explanations and mechanisms involved in parasite PCD are poorly understood. Explaining why unicellular organisms appear to undergo 'suicide' is a challenge for evolutionary biology and uncovering death executors and pathways is a challenge for molecular and cell biology. Bioinformatics has the potential to integrate these approaches by revealing homologies in the PCD machinery of diverse taxa and evaluating their evolutionary trajectories. As the molecular mechanisms of apoptosis in model organisms are well characterised, and recent data suggest similar mechanisms operate in protozoan parasites, key questions can now be addressed. These questions include: which elements of apoptosis machinery appear to be shared between protozoan parasites and multicellular taxa and, have these mechanisms arisen through convergent or divergent evolution? We use bioinformatics to address these questions and our analyses suggest that apoptosis mechanisms in protozoan parasites and other taxa have diverged during their evolution, that some apoptosis factors are shared across taxa whilst others have been replaced by proteins with similar biochemical activities
Analysis and optimalization of warehouse stock management in the AMF Reece Company
No full textBakalářská práce se zabývá hledáním možných nákladových úspor v oblasti vnitropodnikové logistiky v podniku AMF Reece s.r.o. Pro práci byl vybrán průmyslový šicí stroj z firemního sortimentu S-4000 ISBH+I, na kterém byly vytipovány strategicky významné díly. Byla provedena analýza současného stavu řízení zásob a nákupu vybraných dílů v období let 2003-2008. Vytvořeno bylo pět nových návrhů změn v současném systému, jejichž cílem je dosáhnout možných úspor. Pro tvorbu návrhů posloužila zpracovaná spotřební a finanční prognóza pro rok 2009. Návrhy nových řešení se pohybují v oblasti dodavatelské scény a přepravy materiálu zásobovací strategie..In the bachelor thesis, possible costs reductions are sought for the internal logistics of the firm AMF Reece s.r.o. From the company products, the industrial sewing machine S-4000 ISBH+I was chosen and its strategically important parts were specified. An analysis was carried out dealing with the current situation of the stock management and the management of machine parts purchase between 2003 and 2008. Five changes of the current system are thus suggested to reduce the costs. The suggestions are based on consumer and financial prognosis for 2009 and involve changes concerning suppliers and logistics
<i>No se sabe</i>: entrevista a José Eduardo Jorge
No full textEntrevista al investigador de la UNLP José Eduardo Jorge, especialista en cultura política. Jorge, además, es miembro del Consejo Directivo del Instituto de Investigación en Comunicación (IICOM), director de proyectos de investigación acreditados y autor de un centenar de artículos científicos y de divulgación sobre Cultura Política y Comunicación Política. Autor también del libro Cultura Política y Democracia en Argentina (Edulp, 2010). Revisor de artículos científicos de la revista Questión.Al hacer clic en el enlace que figura en "Documentos relacionados", pueden accederse a todos los trabajos de José Eduardo Jorge presentes en el repositorio.Radio Universidad Nacional de La Plat
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