2,158 research outputs found

    CCm performance in Arctic and Antarctic seaweeds in a warming and acidifying marine environment

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    Presentación oral al congresoOcean acidification and warming are affecting with special intensity the polar coastal ecosystems. The Arctic kelps Saccharina latissima and Laminaria solidungula from Kongsfjorden (Svalbard) were cultured at 4 and 9 ºC in combination with current (390 ppm, CC) and increased (1200 ppm, HC) levels of atmospheric CO2. The Antarctic endemic Desmarestia anceps and D. menziesii were cultured at 2 and 7 ºC, and also at CC and HC.For all these species ∂13C values suggested an absence of deactivation of carbon concentrating mechanisms at increased CO2 levels. The lack of inhibition of CCM at high CO2 shown by ∂13C values seems to be a common pattern in polar species, but it is not related to responses in photosynthesis and growth. Growth of both Arctic species were largely unaffected by increased CO2 conditions, regardless the temperature. In contrast, the Antarctic species were favored by high CO2, specially at the highest temperature. External carbonic anhydrase (eCA) was responsible for about 50% to 80% of the photosynthetic O2 evolution in all the species, according to inhibition assays using DBS. CO2 promoted a decrease in eCA contribution to O2 evolution in the Antarctic species but not in the Arctic ones. The addition of EZ did not promote further inhibition in any species, indicating a low relevance of internal CA, although a concomitant inhibition of eCA may mask this contribution if no other mechanism of active transport was operating. Our latest results of the gene expression of D. anceps reveal that there is a low response to CO2. The relevance of this resilience to CO2 in polar environments will be discussed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Food or medicine? The food-medicine interface in households in Sylhet.

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    Bangladesh has a rich traditional plant-medicine use, drawing on Ayurveda and Unami medicine. How these practices translate into people׳s homes and lives vary. Furthermore, the overlap between food and medicine is blurred and context-specific. This paper explores the food-medicine interface as experienced by Bengali women in their homes, in the context of transnational and generational changes

    Food, home and health: the meanings of food amongst Bengali Women in London

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    Background This paper explores the nature of food and plants and their meanings in a British Bengali urban context. It focuses on the nature of plants and food in terms of their role in home making, transnational connections, generational change and concepts of health. Methods An ethnographic approach to the research was taken, specific methods included participant observation, focus group discussions and semi-structured interviews. Thirty women of Bengali origin were mostly composed of “mother” and “daughter” pairs. The mothers were over 45 years old and had migrated from Bangladesh as adults and their grown-up daughters grew up in the UK. Results Food and plants play an important role in the construction of home “here” (London) while continuing to connect people to home “there” (Sylhet). This role, however, changes and is re-defined across generations. Looking at perceptions of “healthy” and “unhealthy” food, particularly in the context of Bengali food, multiple views of what constitutes “healthy” food exist. However, there appeared to be little two-way dialogue about this concept between the research participants and health professionals. This seems to be based on “cultural” and power differences that need to be addressed for a meaningful dialogue to occur. Conclusion In summary, this paper argues that while food is critical to the familial spaces of home (both locally and globally), it is defined by a complex interplay of actors and wider meanings as illustrated by concepts of health and what constitutes Bengali food. Therefore, we call for greater dialogue between health professionals and those they interact with, to allow for an enhanced appreciation of the dynamic nature of food and plants and the diverse perceptions of the role that they play in promoting health

    The workload of web-based consultations with atopic eczema patients at home

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    Abstract Background Atopic eczema is a chronic inflammatory non-contagious skin disease characterised by intensive itch and inflamed skin. Due to its chronic and relapsing course atopic eczema imposes a great burden on affected families. Review articles about home care telemedicine have indicated advantageous effects of home telehealth. However, few studies have investigated how home care telemedicine applications affect the workload of the clinician. Methods The use of a web-based counselling system was recorded through computerised logging. The doctor who answered the requests sent via the Internet recorded the amount of time needed for reading and answering 93 consecutive requests. Results The time needed by the physician to read and answer a request was less than 5 minutes in 60% of the cases. The doctor spent significantly more time to answer requests that had photographs attached compared to requests without photographs (P = 0.005). The time needed to answer requests received during the winter season (October-March) was significantly longer than the rest of the year (P = 0.023). There was no correlation between the answering time and the age of the patient. Conclusions Individual web-based follow-up of atopic eczema patients at home is feasible. The amount of time needed for the doctor to respond to a request from the patient appears to be small. The answering time seems to depend on whether photographs are supplied and also on seasonal variations of disease activity. Since the management of atopic eczema is complex involving many different types of treatments and educational aspects, we expect this type of communication to be useful also to other chronic disease patients requiring close follow-up.</p

    Morphology and Nanomechanics of Sensory Neurons Growth Cones following Peripheral Nerve Injury

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    A prior peripheral nerve injury in vivo, promotes a rapid elongated mode of sensory neurons neurite regrowth in vitro. This in vitro model of conditioned axotomy allows analysis of the cellular and molecular mechanisms leading to an improved neurite re-growth. Our differential interference contrast microscopy and immunocytochemistry results show that conditioned axotomy, induced by sciatic nerve injury, did not increase somatic size of adult lumbar sensory neurons from mice dorsal root ganglia sensory neurons but promoted the appearance of larger neurites and growth cones. Using atomic force microscopy on live neurons, we investigated whether membrane mechanical properties of growth cones of axotomized neurons were modified following sciatic nerve injury. Our data revealed that neurons having a regenerative growth were characterized by softer growth cones, compared to control neurons. The increase of the growth cone membrane elasticity suggests a modification in the ratio and the inner framework of the main structural proteins

    Signatures of arithmetic simplicity in metabolic network architecture

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    Metabolic networks perform some of the most fundamental functions in living cells, including energy transduction and building block biosynthesis. While these are the best characterized networks in living systems, understanding their evolutionary history and complex wiring constitutes one of the most fascinating open questions in biology, intimately related to the enigma of life's origin itself. Is the evolution of metabolism subject to general principles, beyond the unpredictable accumulation of multiple historical accidents? Here we search for such principles by applying to an artificial chemical universe some of the methodologies developed for the study of genome scale models of cellular metabolism. In particular, we use metabolic flux constraint-based models to exhaustively search for artificial chemistry pathways that can optimally perform an array of elementary metabolic functions. Despite the simplicity of the model employed, we find that the ensuing pathways display a surprisingly rich set of properties, including the existence of autocatalytic cycles and hierarchical modules, the appearance of universally preferable metabolites and reactions, and a logarithmic trend of pathway length as a function of input/output molecule size. Some of these properties can be derived analytically, borrowing methods previously used in cryptography. In addition, by mapping biochemical networks onto a simplified carbon atom reaction backbone, we find that several of the properties predicted by the artificial chemistry model hold for real metabolic networks. These findings suggest that optimality principles and arithmetic simplicity might lie beneath some aspects of biochemical complexity

    Abundant Fas expression by gastrointestinal stromal tumours may serve as a therapeutic target for MegaFasL

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    Although the tyrosine kinase inhibitor imatinib has been shown to be an active agent in patients with gastrointestinal stromal tumours (GIST), complete remissions are almost never seen and most patients finally experience disease progression during their course of treatment. An alternative therapeutic option is to target death receptors such as Fas. We showed that a panel of imatinib-sensitive (GIST882) and imatinib-resistant (GIST48, GIST430 and GIST430K-) cell lines expressed Fas. MegaFasL, a recently developed hexameric form of soluble Fas ligand (FasL), appeared to be an active apoptosis-inducing agent in these cell lines. Moreover, MegaFasL potentiated the apoptotic effects of imatinib. Immunohistochemical evaluations, in 45 primary GISTs, underscored the relevance of the Fas pathway: Fas was expressed in all GISTs and was expressed strongly in 93%, whereas FasL was expressed at moderate and strong levels in 35 and 53% of GISTs, respectively. Fas and FasL expression were positively correlated in these primary GISTs, but there was no association between Fas or FasL expression and primary site, histological subtype, tumour size, mitotic index, risk classification, and KIT mutation status. The abundant immunohistochemical Fas and FasL expression were corroborated by western blot analysis. In conclusion, our data implicate Fas as a potential therapeutic target in GIST
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