Saben comptar els animals?

La complexitat de les matemàtique

Social evolution: A biological history of cooperation

To talk about life is to talk about cooperation. Its evolutionary origin, different levels of organisation, and current complexity are the result of cooperation between different biological entities. This is also the case with animal societies, including the most complex of them all, the human society. Our language and extraordinary culture, our cities and vast social networks, are the fruit of cooperation. In a world dominated by Darwinian competition, how has cooperation come to play such an important role? Social evolution, the study of the biological bases of cooperation, tackles this question. From the origin of the first cell and to the explosion of social life in animals, social evolution explains how and why cooperation has guided life on our planet.; Hablar de la vida es hablar de cooperación. Su origen evolutivo, sus distintos niveles de organización o su actual complejidad son consecuencia de la cooperación entre entidades biológicas distintas. También lo son las sociedades animales, entre las que se incluye la sociedad más compleja de todas, la humana. Nuestro lenguaje, nuestra extraordinaria cultura, nuestras ciudades y vastas redes sociales, son fruto de la cooperación. ¿Cómo es posible que, en un mundo dominado por la competencia por los recursos, por la evolución darwiniana, la cooperación haya llegado a jugar un papel tan relevante? La evolución social, el estudio de las bases biológicas de la cooperación, nos permite responder a esta pregunta. En un recorrido que empieza con la primera célula y termina con la explosión de la vida social en los animales, la evolución social nos explica cómo y por qué la cooperación ha guiado la historia de la vida en este planeta.; Parlar de la vida és parlar de cooperació. El seu origen evolutiu, els seus diferents nivells d’organització o la seua actual complexitat són conseqüència de la cooperació entre entitats biològiques diferents. També ho són les societats animals, entre les quals s’inclou la societat més complexa de totes, la humana. El nostre llenguatge, la nostra extraordinària cultura, les nostres ciutats i vastes xarxes socials, són fruit de la cooperació. Com és possible que, en un món dominat per la competència pels recursos, per l’evolució darwiniana, la cooperació haja arribat a representar un paper tan rellevant? L’evolució social, l’estudi de les bases biològiques de la cooperació, ens permet respondre a aquesta pregunta. En un recorregut que comença amb la primera cèl·lula i acaba amb l’explosió de la vida social en els animals, l’evolució social ens explica com i per què la cooperació ha guiat la història de la vida en aquest planeta

Sex ratio at mating does not modulate age fitness effects in Drosophila melanogaster

Understanding the effects of male and female age on reproductive success is vital to explain the evolution of life history traits and sex‐specific aging. A general prediction is that pre‐/postmeiotic aging processes will lead to a decline in the pre‐ and post‐copulatory abilities of both males and females. However, in as much the sexes have different strategies to optimize their fitness, the decline of reproductive success late in life can be modulated by social context, such as sex ratio, in a sex‐specific manner. In this study, we used Drosophila melanogaster to investigate whether sex ratio at mating modulates age effects on male and female reproductive success. As expected, male and female age caused a decrease in reproductive success across male‐biased and female‐biased social contexts but, contrary to previous findings, social context did not modulate age‐related fitness decline in either of the two sexes. We discuss these results in the light of how sex ratio might modulate pre‐/postcopulatory abili‐ties and the opportunity for inter‐ and intrasexual competition in D. melanogaster, and generally suggest that social context effects on these processes are likely to be species specific

Perception costs of reproduction can magnify sexual selection

We outline two avenues for future research:(1) in model organisms (for example, D. melanogaster), manipulating perception costs in males of varying quality and subsequently testing whether this results in an increase or decrease of male fitness variance; and (2) comparing short-term (that is, no perception costs) versus long-term estimations of male fitness variance in single cohorts via meta-analysis or ad hoc behavioural experiments

Rir para refletir : um pedacinho do mundo de Luis Fernando Veríssimo (Caderno de leitura)

Recurso pedagógico desenvolvido como parte da dissertação: SANTANA, Catiana Santos Correia. Crônica de humor : objeto de ensino-aprendizagem na perspectiva do interacinismo sociodiscursivo. 2016. 180 f. Dissertação (Mestrado Profissional em Letras) - Universidade Federal de Sergipe, Itabaiana, SE, 2016.Itabaiana, S

La evolución es un hecho tan indiscutible como que la Tierra no es plana

Reproducció del document publicat a: https://theconversation.com/la-evolucion-es-un-hecho-tan-indiscutible-como-que-la-tierra-no-es-plana-162135Nos ha sorprendido leer un artículo donde un conocido escritor niega la evolución biológica, ignorando la evidencia científica. No es nuestra intención antagonizar con dicho autor ni discutir uno por uno los muchos errores que contiene su text

High incidence of clinical fragility fractures in postmenopausal women with rheumatoid arthritis. A case-control study.

Objectives: To estimate the incidence of clinical fragility fractures in postmenopausal women with rheumatoid arthritis (RA) and analyze risk factors for fracture. Methods: Incidence of clinical fragility fractures in 330 postmenopausal women with RA was compared to that of a control population of 660 age-matched postmenopausal Spanish women. Clinical fractures during the previous five years were recorded. We analyzed associations with risk factors for fracture in both populations and with disease-related variables in RA patients. Results: Median age of RA patients was 64 years; median RA duration was eight years. Sixty-nine percent were in remission or on low activity. Eighty-five percent had received glucocorticoids (GCs); 85 %, methotrexate; and 40 %, ≥1 biologic DMARD. Fifty-four patients and 47 controls had ≥1 major osteoporotic fracture (MOF). Incidence of MOFs was 3.55 per 100 patient-year in patients and 0.72 in controls (HR: 2.6). Risk factors for MOFs in RA patients were age, previous fracture, parental hip fracture, years since menopause, BMD, erosions, disease activity and disability, and cumulative dose of GCs. Previous fracture in RA patients was a strong risk for MOFs (HR: 10.37). Conclusion: Of every 100 postmenopausal Spanish women with RA, 3-4 have a MOF per year. This is more than double that of the general population. A previous fracture poses a high risk for a new fracture. Other classic risk factors for fracture, RA disease activity and disability, and the cumulative dose of GCs are associated with fracture development

A systematic map of studies testing the relationship between temperature and animal reproduction

Funding: This work was funded by the European Society for Evolution (which funds a Special Topic Network on Evolutionary Ecology of Thermal Fertility Limits to CF, AB, RRS and TARP), the Natural Environment Research Council (NE/P002692/1 to TARP, AB and RRS, NE/X011550/1 to LRD and TARP), the Biotechnology and \Biological Sciences Research Council (BB/W016753/1 to AB, TARP and RRS) and a Heisenberg fellowship from the German Research Foundation (FR 2973/11-1 to CF).1. Exposure to extreme temperatures can negatively affect animal reproduction, by disrupting the ability of individuals to produce any offspring (fertility), or the number of offspring produced by fertile individuals (fecundity). This has important ecological consequences, because reproduction is the ultimate measure of population fitness: a reduction in reproductive output lowers the population growth rate and increases the extinction risk. Despite this importance, there have been no large‐scale summaries of the evidence for effect of temperature on reproduction. 2. We provide a systematic map of studies testing the relationship between temperature and animal reproduction. We systematically searched for published studies that statistically test for a direct link between temperature and animal reproduction, in terms of fertility, fecundity or indirect measures of reproductive potential (gamete and gonad traits). 3. Overall, we collated a large and rich evidence base, with 1654 papers that met our inclusion criteria, encompassing 1191 species. 4. The map revealed several important research gaps. Insects made up almost half of the dataset, but reptiles and amphibians were uncommon, as were non‐arthropod invertebrates. Fecundity was the most common reproductive trait examined, and relatively few studies measured fertility. It was uncommon for experimental studies to test exposure of different life stages, exposure to short‐term heat or cold shock, exposure to temperature fluctuations, or to independently assess male and female effects. Studies were most often published in journals focusing on entomology and pest control, ecology and evolution, aquaculture and fisheries science, and marine biology. Finally, while individuals were sampled from every continent, there was a strong sampling bias towards mid‐latitudes in the Northern Hemisphere, such that the tropics and polar regions are less well sampled. 5. This map reveals a rich literature of studies testing the relationship between temperature and animal reproduction, but also uncovers substantial missing treatment of taxa, traits, and thermal regimes. This database will provide a valuable resource for future quantitative meta‐analyses, and direct future studies aiming to fill identified gaps.Publisher PDFPeer reviewe

Multicentre, randomised, single-blind, parallel group trial to compare the effectiveness of a Holter for Parkinson's symptoms against other clinical monitoring methods: study protocol

Introduction In recent years, multiple studies have aimed to develop and validate portable technological devices capable of monitoring the motor complications of Parkinson's disease patients (Parkinson's Holter). The effectiveness of these monitoring devices for improving clinical control is not known. Methods and analysis This is a single-blind, cluster-randomised controlled clinical trial. Neurologists from Spanish health centres will be randomly assigned to one of three study arms (1:1:1): (a) therapeutic adjustment using information from a Parkinson?s Holter that will be worn by their patients for 7 days, (b) therapeutic adjustment using information from a diary of motor fluctuations that will be completed by their patients for 7 days and (c) therapeutic adjustment using clinical information collected during consultation. It is expected that 162 consecutive patients will be included over a period of 6 months. The primary outcome is the efficiency of the Parkinson?s Holter compared with traditional clinical practice in terms of Off time reduction with respect to the baseline (recorded through a diary of motor fluctuations, which will be completed by all patients). As secondary outcomes, changes in variables related to other motor complications (dyskinesia and freezing of gait), quality of life, autonomy in activities of daily living, adherence to the monitoring system and number of doctor?patient contacts will be analysed. The noninferiority of the Parkinson's Holter against the diary of motor fluctuations in terms of Off time reduction will be studied as the exploratory objective. Ethics and dissemination approval for this study has been obtained from the Hospital Universitari de Bellvitge Ethics Committee. The results of this study will inform the practical utility of the objective information provided by a Parkinson's Holter and, therefore, the convenience of adopting this technology in clinical practice and in future clinical trials. We expect public dissemination of the results in 2022.Funding This work is supported by AbbVie S.L.U, the Instituto de Salud Carlos III [DTS17/00195] and the European Fund for Regional Development, 'A way to make Europe'