Resposta de les espècies algals a canvis en la disponibilitat de nutrients

L'objectiu general del projecte de tesi és el d'estudiar la resposta de les espècies algals a canvis en la disponibilitat de nutrients (i.e. NH4+/NO3-/PO43-). La hipòtesi de partida és que les alteracions en les concentracions absolutes i relatives de nutrients provoquen canvis en l'activitat de les espècies algals que seran més o menys intensos en funció de l’espècie i que són fruit de les característiques eco-evolutives intrínseques de cadascuna. Els objectius concrets es diferencien per l’escala temporal a la que s’observa la resposta, que va des de minuts fins a setmanes: Objectiu 1. Analitzar canvis a curt termini en l’activitat de les espècies degut a augments puntuals en la concentració absoluta i relativa de nutrients (NH4+/NO3-/ PO43-). S'ha vist que algunes espècies redueixen l’activitat fotosintètica a curt termini per destinar tots els recursos a l’assimilació de nutrients (Elrifi i Turpin 1986). S’estudiarà si aquesta pauta es troba de forma generalitzada i si respon a patrons evolutius, funcionals (mida, forma...) o ecològics (disponibilitat de nutrients). Objectiu 2. Analitzar, a mig termini, l’activitat de les espècies algals a diferents concentracions de NH4+/NO3-/ PO43-. Les respostes s’intentaran modelar, de manera que els paràmetres es puguin considerar trets funcionals característics de les espècies. S'estudiarà si la variabilitat en aquests trets respon a patrons evolutius o a d’altres trets funcionals com per exemple la mida. Objectiu 3. Analitzar com afecta, a llarg termini, la disponibilitat de nutrients en la composició d’espècies. Es detectarà quines espècies són més sensibles a les condicions de NH4+:NO3- i N:P del medi, i com es relaciona això amb les respostes específiques trobades en els objectius anteriors.

Obesity and survival in operable breast cancer patients treated with adjuvant anthracyclines and taxanes according to pathological subtypes: a pooled analysis.

INTRODUCTION Obesity is an unfavorable prognostic factor in breast cancer (BC) patients regardless of menopausal status and treatment received. However, the association between obesity and survival outcome by pathological subtype requires further clarification. METHODS We performed a retrospective analysis including 5,683 operable BC patients enrolled in four randomized clinical trials (GEICAM/9906, GEICAM/9805, GEICAM/2003-02, and BCIRG 001) evaluating anthracyclines and taxanes as adjuvant treatments. Our primary aim was to assess the prognostic effect of body mass index (BMI) on disease recurrence, breast cancer mortality (BCM), and overall mortality (OM). A secondary aim was to detect differences of such prognostic effects by subtype. RESULTS Multivariate survival analyses adjusting for age, tumor size, nodal status, menopausal status, surgery type, histological grade, hormone receptor status, human epidermal growth factor receptor 2 (HER2) status, chemotherapy regimen, and under-treatment showed that obese patients (BMI 30.0 to 34.9) had similar prognoses to that of patients with a BMI < 25 (reference group) in terms of recurrence (Hazard Ratio [HR] = 1.08, 95% Confidence Interval [CI] = 0.90 to 1.30), BCM (HR = 1.02, 0.81 to 1.29), and OM (HR = 0.97, 0.78 to 1.19). Patients with severe obesity (BMI ≥ 35) had a significantly increased risk of recurrence (HR = 1.26, 1.00 to 1.59, P = 0.048), BCM (HR = 1.32, 1.00 to 1.74, P = 0.050), and OM (HR = 1.35, 1.06 to 1.71, P = 0.016) compared to our reference group. The prognostic effect of severe obesity did not vary by subtype. CONCLUSIONS Severely obese patients treated with anthracyclines and taxanes present a worse prognosis regarding recurrence, BCM, and OM than patients with BMI < 25. The magnitude of the harmful effect of BMI on survival-related outcomes was similar across subtypes.

Where microbiology meets microengineering: design and applications of reporter bacteria.

Bacteria have long been the targets for genetic manipulation, but more recently they have been synthetically designed to carry out specific tasks. Among the simplest of these tasks is chemical compound and toxicity detection coupled to the production of a quantifiable reporter signal. In this Review, we describe the current design of bacterial bioreporters and their use in a range of assays to measure the presence of harmful chemicals in water, air, soil, food or biological specimens. New trends for integrating synthetic biology and microengineering into the design of bacterial bioreporter platforms are also highlighted.

Two-sided learning in new keynesian models: dynamics, (lack of) convergence and the value of information

This paper investigates the role of learning by private agents and the central bank (two-sided learning) in a New Keynesian framework in which both sides of the economy have asymmetric and imperfect knowledge about the true data generating process. We assume that all agents employ the data that they observe (which may be distinct for different sets of agents) to form beliefs about unknown aspects of the true model of the economy, use their beliefs to decide on actions, and revise these beliefs through a statistical learning algorithm as new information becomes available. We study the short-run dynamics of our model and derive its policy recommendations, particularly with respect to central bank communications. We demonstrate that two-sided learning can generate substantial increases in volatility and persistence, and alter the behavior of the variables in the model in a signifficant way. Our simulations do not converge to a symmetric rational expectations equilibrium and we highlight one source that invalidates the convergence results of Marcet and Sargent (1989). Finally, we identify a novel aspect of central bank communication in models of learning: communication can be harmful if the central bank's model is substantially mis-specified

Epigenetic mechanisms in non-alcoholic fatty liver disease: An emerging field.

Non-alcoholic fatty liver disease (NAFLD) is an emerging health concern in both developed and non-developed world, encompassing from simple steatosis to non-alcoholic steatohepatitis (NASH), cirrhosis and liver cancer. Incidence and prevalence of this disease are increasing due to the socioeconomic transition and change to harmful diet. Currently, gold standard method in NAFLD diagnosis is liver biopsy, despite complications and lack of accuracy due to sampling error. Further, pathogenesis of NAFLD is not fully understood, but is well-known that obesity, diabetes and metabolic derangements played a major role in disease development and progression. Besides, gut microbioma and host genetic and epigenetic background could explain considerable interindividual variability. Knowledge that epigenetics, heritable events not caused by changes in DNA sequence, contribute to development of diseases has been a revolution in the last few years. Recently, evidences are accumulating revealing the important role of epigenetics in NAFLD pathogenesis and in NASH genesis. Histone modifications, changes in DNA methylation and aberrant profiles or microRNAs could boost development of NAFLD and transition into clinical relevant status. PNPLA3 genotype GG has been associated with a more progressive disease and epigenetics could modulate this effect. The impact of epigenetic on NAFLD progression could deserve further applications on therapeutic targets together with future non-invasive methods useful for the diagnosis and staging of NAFLD.

Efecte de la recurrència dels incendis sobre la vegetació i el sòl a les zones de matollar del Macizo Central Ourensano

El matollar sec europeu format per Erica australis, Erica arborea, Pterosparum tridentatum, Halimium lasianthum i Calluna vulgaris com a espècies predominants és cremat en les serralades del Massís Central de forma repetida durant el pas dels anys. Això ha sigut, tradicionalment, a causa de la necessitat de mantenir-lo transitable per al bestiar, encara que altres circumstàncies s’han afegit actualment a aquesta necessitat, que incrementen el risc d’incendi d’aquesta comunitat, disparant-se el número d’incendis en els últims 30 anys. Sabent això, vam decidir realitzar un estudi a les zones de matollar que trobem al Massís Central situat a la zona del Concello de Villariño de Conso, a Ourense, per conèixer com es comporten les espècies característiques d’aquest tipus d’ecosistema després dels incendis, mitjançant la realització de mostrejos i perfils del sòl. D’aquesta manera hem volgut veure com es desenvolupen les espècies vegetals de matollar al llarg del temps, després de ser cremats. Gràcies a l’estudi hem pogut veure com el matollar observat te unes característiques que li permet sobreviure als incendis i tindre una capacitat de regeneració elevada després de patir aquesta pertorbació. Això es degut a la capacitat per rebrotar d’aquestes espècies arbustives i a la seva competitivitat. També hem vist com a necessari, donar un valor econòmic a la bona conservació de l’hàbitat, per tal de que la població local abandoni pràctiques de gestió forestal nocives, com el foc.

PPAR-mediated activity of phthalates: A link to the obesity epidemic?

The endocrine disruption hypothesis asserts that exposure to small amounts of some chemicals in the environment may interfere with the endocrine system and lead to harmful effects in wildlife and humans. Many of these chemicals may interact with members of the nuclear receptor superfamily. Peroxisome proliferator-activated receptors (PPARs) are such candidate members, which interact with many different endogenous and exogenous lipophilic compounds. More particularly, the roles of PPARs in lipid and carbohydrate metabolism raise the question of their activation by a sub-class of pollutants, tentatively named "metabolic disrupters". Phthalates are abundant environmental micro-pollutants in Europe and North America and may belong to this class. Mono-ethyl-hexyl-phthalate (MEHP), a metabolite of the widespread plasticizer di-ethyl-hexyl-phthalate (DEHP), has been found in exposed organisms and interacts with all three PPARs. A thorough analysis of its interactions with PPARgamma identified MEHP as a selective PPARgamma modulator, and thus a possible contributor to the obesity epidemic.

Using environmental niche modeling to understand biological invasions in a changing world

L'activité humaine affecte particulièrement la biodiversité, qui décline à une vitesse préoccupante. Parmi les facteurs réduisant la biodiversité, on trouve les espèces envahissantes. Symptomatiques d'un monde globalisé où l'échange se fait à l'échelle de la planète, certaines espèces, animales ou végétales, sont introduites, volontairement ou accidentellement par l'activité humaine (par exemple lors des échanges commerciaux ou par les voyageurs). Ainsi, ces espèces atteignent des régions qu'elles n'auraient jamais pu coloniser naturellement. Une fois introduites, l'absence de compétiteur peut les rendre particulièrement nuisibles. Ces nuisances sont plus ou moins directes, allant de problèmes sanitaires (p. ex. les piqûres très aigües des fourmis de feu, originaires d'Amérique du Sud et colonisant à une vitesse fulgurante les USA, l'Australie ou la Chine) à des nuisances sur la biodiversité (p. ex. les ravages de la perche du Nil sur la diversité unique des poissons Cichlidés du Lac Victoria). Il est donc important de pouvoir prévenir de telles introductions. De plus, pour le biologiste, ces espèces représentent une rare occasion de pouvoir comprendre les mécanismes évolutifs et écologiques qui expliquent le succès des envahissantes dans un monde où les équilibres sont bouleversés. Les modèles de niche environnementale sont un outil particulièrement utile dans le cadre de cette problématique. En reliant des observations d'espèces aux conditions environnementales où elles se trouvent, ils peuvent prédire la distribution potentielle des envahissantes, permettant d'anticiper et de mieux limiter leur impact. Toutefois, ils reposent sur des hypothèses pas évidentes à démontrer. L'une d'entre elle étant que la niche d'une espèce reste constante dans le temps, et dans l'espace. Le premier objectif de mon travail est de comparer si la niche d'une espèce envahissante diffère entre sa distribution d'origine native et celle d'origine introduite. En étudiant 50 espèces de plantes et 168 espèces de Mammifères, je démontre que c'est le cas et que par corolaire, il est possible de prédire leurs distributions. La deuxième partie de mon travail consiste à comprendre quelles seront les interactions entre le changement climatiques et les envahissantes, afin d'estimer leur impact sous un climat réchauffé. En étudiant la distribution de 49 espèces de plantes envahissantes, je démontre que les montagnes, régions relativement préservée par ce problème, deviendront bien plus exposées aux risques d'invasions biologiques. J'expose aussi comment les interactions entre l'activité humaine, le réchauffement climatique et les espèces envahissantes menacent la vigne sauvage en Europe et propose des zones géographiques particulièrement adaptée pour sa conservation. Enfin, à une échelle beaucoup plus locale, je montre qu'il est possible d'utiliser ces modèles de niches le long d'une rivière à une échelle extrêmement fine (1 mètre), potentiellement utile pour rationnaliser des mesures de conservations sur le terrain. - Biodiversity is significantly negatively affected by human activity. Invasive species are one of the most important factors causing biodiversity's decline. Intimately linked to the era of global trade, some plant or animal species can be accidentally or casually introduced with human activity (e.g. trade or travel). In this way, these species reach areas they could never reach through natural dispersal. Once naturalized, the lack of competitors can make these species highly noxious. Their effect is more or less direct, from sanitary problems (e.g. the harmful sting of Fire Ants, originating from South America and now spreading throughout USA, China and Australia) or can affect biodiversity (e.g. the Nile perch, devastating the one of the richest hotspot of Cichlid fishes diversity in Lake Victoria). It is thus important to prevent such harmful introductions. Moreover, invasive species represent for biologists one of the rare occasions to understand the evolutionary and ecological mechanisms behind the success of invaders in a world where natural equilibrium is already disturbed. Environmental niche models are particularly useful to tackle this problematic. By relating species observation to the environmental conditions where they occur, they can predict the potential distribution of invasive species, allowing a better anticipation and thus limiting their impact. However, they rely on strong assumption, one of the most important being that the modeled niche remains constant through space and time. The first aim of my thesis is to quantify the difference between the native and the invaded niche. By investigating 50 plant and 168 mammal species, I show that the niche is at least partially conserved, supporting for reliable predictions of invasive' s potential distributions. The second aim of my thesis is to understand the possible interactions between climate change and invasive species, such as to assess their impact under a warmer climate. By studying 49 invasive plant species, I show that mountain areas, which were relatively preserved, will become more suitable for biological invasions. Additionally, I show how interactions between human activity, global warming and invasive species are threatening the wild grapevine in Europe and propose geographical areas particularly adapted for conservation measures. Finally, at a much finer scale where conservation plannings ultimately take place, I show that it is possible to model the niche at very high resolution (1 meter) in an alluvial area allowing better prioritizations for conservation.

Iron and transfusion medicine.

Blood bankers have focused their energy to secure blood transfusion, and only recently have studies been published on the effect of blood donation on iron metabolism. In many facilities, hemoglobin measurement is only performed just before or even during blood donation, but the determination of iron stores is largely ignored. The 2013 paradox of transfusion medicine is due to the fact that blood donation may be harmful and leads to iron deficiency with or without anemia, but for other individuals, it may be a healthy measure preventing type 2 diabetes. The purpose of this review is to discuss iron metabolism in the perspective of blood donation, notably regarding their possible genetic profiles that eventually will discriminate "good" iron absorbers from "bad" iron responders.

Is it worth treating fever in intensive care unit patients? Preliminary results from a randomized trial of the effect of external cooling.

BACKGROUND: Antipyresis is a common clinical practice in intensive care, although it is unknown if fever is harmful, beneficial, or a negligible adverse effect of infection and inflammation. METHODS: In a randomized study, rectal temperature and discomfort were assessed in 38 surgical intensive care unit patients without neurotrauma or severe hypoxemia and with fever (temperature >/=38.5 degrees C) and systemic inflammatory response syndrome. Eighteen patients received external cooling while 20 received no antipyretic treatment. RESULTS: Temperature and discomfort decreased similarly in both groups after 24 hours. No significant differences in recurrence of fever, incidence of infection, antibiotic therapy, intensive care unit and hospital length of stay, or mortality were noted between the groups. CONCLUSIONS: These results suggest that the systematic suppression of fever may not be useful in patients without severe cranial trauma or significant hypoxemia. Letting fever take its natural course does not seem to harm patients with systemic inflammatory response syndrome or influence the discomfort level and may save costs.

Estudi del valor socioeducatiu de l’amistat en el procés d’integració social dels adolescents immigrants a Catalunya

L'escola és avui dia un espai de cohabitació on els adolescents immigrants construeixen i consoliden la seva identitat. En aquest context les relacions d'amistat determinen en bona mesura el grau d'aprenentatge de la cultura del país d'acolliment així com la vinculació simbòlica amb la societat que els acull. Aquesta investigació explora les característiques de les relacions d'amistat dels adolescents immigrants en el context de l'escola. La mostra va estar integrada per 682 estudiants dels últims cursos de Secundària Bàsica Obligatòria (15-16 anys), de sis instituts de Catalunya. Els resultats revelen que els adolescents immigrants en bona mesura nominen com a amics a altres adolescents de la seva mateixa cultura i a altres pertanyents a altres cultures però amb els quals comparteix la condició d'immigrant. En canvi, els amics dels adolescents autòctons pertanyen, majoritàriament, a la seva pròpia cultura. Finalment, s'aprecien algunes diferències respecte al suport que ofereixen els amics dels diferents grups, sent lleugerament inferior el suport que perceben els adolescents d'origen estranger. Aquests resultats confirmen les conclusions d'estudis precedents i alerten sobre la necessitat d'aprofundir en les seves causes per evitar els negatius efectes que pot generar per als adolescents immigrats les deficiències del procés de socialització a l'entorn de l'escola.

Passive smoking in babies: The BIBE Study (Brief Intervention in babies. Effectiveness)

Background: There is evidence that exposure to passive smoking in general, and in babies in particular, is an important cause of morbimortality. Passive smoking is related to an increased risk of pediatric diseases such as sudden death syndrome, acute respiratory diseases, worsening of asthma, acute-chronic middle ear disease and slowing of lung growth.The objective of this article is to describe the BIBE study protocol. The BIBE study aims to determine the effectiveness of a brief intervention within the context of Primary Care, directed to mothers and fathers that smoke, in order to reduce the exposure of babies to passive smoking (ETS).Methods/DesignCluster randomized field trial (control and intervention group), multicentric and open. Subject: Fathers and/or mothers who are smokers and their babies (under 18 months) that attend pediatric services in Primary Care in Catalonia.The measurements will be taken at three points in time, in each of the fathers and/or mothers who respond to a questionnaire regarding their baby's clinical background and characteristics of the baby's exposure, together with variables related to the parents' tobacco consumption. A hair sample of the baby will be taken at the beginning of the study and at six months after the initial visit (biological determination of nicotine). The intervention group will apply a brief intervention in passive smoking after specific training and the control group will apply the habitual care.Discussion: Exposure to ETS is an avoidable factor related to infant morbimortality. Interventions to reduce exposure to ETS in babies are potentially beneficial for their health. The BIBE study evaluates an intervention to reduce exposure to ETS that takes advantage of pediatric visits. Interventions in the form of advice, conducted by pediatric professionals, are an excellent opportunity for prevention and protection of infants against the harmful effects of ETS.

Practical considerations for conducting ecotoxicity test methods with manufactured nanomaterials: what have we learnt so far?

This review paper reports the consensus of a technical workshop hosted by the European network, NanoImpactNet (NIN). The workshop aimed to review the collective experience of working at the bench with manufactured nanomaterials (MNMs), and to recommend modifications to existing experimental methods and OECD protocols. Current procedures for cleaning glassware are appropriate for most MNMs, although interference with electrodes may occur. Maintaining exposure is more difficult with MNMs compared to conventional chemicals. A metal salt control is recommended for experiments with metallic MNMs that may release free metal ions. Dispersing agents should be avoided, but if they must be used, then natural or synthetic dispersing agents are possible, and dispersion controls essential. Time constraints and technology gaps indicate that full characterisation of test media during ecotoxicity tests is currently not practical. Details of electron microscopy, dark-field microscopy, a range of spectroscopic methods (EDX, XRD, XANES, EXAFS), light scattering techniques (DLS, SLS) and chromatography are discussed. The development of user-friendly software to predict particle behaviour in test media according to DLVO theory is in progress, and simple optical methods are available to estimate the settling behaviour of suspensions during experiments. However, for soil matrices such simple approaches may not be applicable. Alternatively, a Critical Body Residue approach may be taken in which body concentrations in organisms are related to effects, and toxicity thresholds derived. For microbial assays, the cell wall is a formidable barrier to MNMs and end points that rely on the test substance penetrating the cell may be insensitive. Instead assays based on the cell envelope should be developed for MNMs. In algal growth tests, the abiotic factors that promote particle aggregation in the media (e.g. ionic strength) are also important in providing nutrients, and manipulation of the media to control the dispersion may also inhibit growth. Controls to quantify shading effects, and precise details of lighting regimes, shaking or mixing should be reported in algal tests. Photosynthesis may be more sensitive than traditional growth end points for algae and plants. Tests with invertebrates should consider non-chemical toxicity from particle adherence to the organisms. The use of semi-static exposure methods with fish can reduce the logistical issues of waste water disposal and facilitate aspects of animal husbandry relevant to MMNs. There are concerns that the existing bioaccumulation tests are conceptually flawed for MNMs and that new test(s) are required. In vitro testing strategies, as exemplified by genotoxicity assays, can be modified for MNMs, but the risk of false negatives in some assays is highlighted. In conclusion, most protocols will require some modifications and recommendations are made to aid the researcher at the bench. [Authors]

Voice Transformations for Extreme Vocal Effects

Extreme Vocal Effects (EVE) in music are so recent that few studies have been carried out about how they are physiologically produced and whether they are harmful or not for the human voice.Voice Transformations in real-time are possible nowadays thanks to new technologies and voice processing algorithms. This Master's Thesis pretends to define and classify these new singing techniques and to create a mapping between the physiological aspect of each EVE to its relative spectrumvariations.Voice Transformation Models based on these mappings are proposed and discussed for each one of these EVEs. We also discuss different transformation methods and strategies in order to obtain better results.A subjective evaluation of the results of the transformations is also presented and discussed along with further work, improvements, and working lines on this field.

Spirituality and religion in outpatients with schizophrenia: A multi-site comparative study of Switzerland, Canada, and the United States

Objective: To assess the importance of spirituality and religious coping among outpatients with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder living in three countries. Method: A total of 276 outpatients (92 from Geneva, Switzerland, 121 from Trois-Rivières, Canada, and 63 from Durham, North Carolina), aged 18-65, were administered a semi-structured interview on the role of spirituality and religiousness in their lives and to cope with their illness. Results: Religion is important for outpatients in each of the three country sites, and religious involvement is higher than in the general population. Religion was helpful (i.e., provided a positive sense of self and positive coping with the illness) among 87% of the participants and harmful (a source of despair and suffering) among 13%. Helpful religion was associated with better social, clinical and psychological status. The opposite was observed for the harmful aspects of religion. In addition, religion sometimes conflicted with psychiatric treatment. Conclusions: These results indicate that outpatients with schizophrenia or schizoaffective disorder often use spirituality and religion to cope with their illness, basically positively, yet sometimes negatively. These results underscore the importance of clinicians taking into account the spiritual and religious lives of patients with schizophrenia.