255 research outputs found

    Spatial and seasonal variation in leaf temperature within the canopy of a tropical forest

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    Understanding leaf temperature (Tleaf) variation in the canopy of tropical forests is critical for accurately calculating net primary productivity because plant respiration and net photosynthesis are highly sensitive to temperature. The objectives of this study were to (1) quantify the spatiotemporal variation of Tleaf in a semi-deciduous tropical forest in Panama and (2) create a season-specific empirical model to predict Tleaf in the canopy. To achieve this, we used a 42 m tall construction crane for canopy access and monitored the microenvironment within the canopy of mature, 20-35 m tall trees of 5 tropical tree species during the wet and the dry season. Tleaf was correlated to photosynthetic photon flux density (PPFD) in the wet season but not in the dry season, possibly due to seasonal differences in wind speed, physiology, and canopy phenology. A structural equation model showed that Tleaf is best explained by air temperature (Tair) and PPFD in the wet season, whereas in the dry season, Tair alone predicted most of the variation in Tleaf. These results suggest the utility of an empirical approach to estimate Tleaf variability where simple meteoro logical data are available. This approach can be incorporated in future models of vegetation-atmosphere carbon and water exchange models of mature tropical forests with similar seasonality. © Inter-Research 2016

    Rapid evolution and biogeographic spread in a colorectal cancer

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    How and when tumoral clones start spreading to surrounding and distant tissues is currently unclear. Here we leveraged a model-based evolutionary framework to investigate the demographic and biogeographic history of a colorectal cancer. Our analyses strongly support an early monoclonal metastatic colonization, followed by a rapid population expansion at both primary and secondary sites. Moreover, we infer a hematogenous metastatic spread under positive selection, plus the return of some tumoral cells from the liver back to the colon lymph nodes. This study illustrates how sophisticated techniques typical of organismal evolution can provide a detailed, quantitative picture of the complex tumoral dynamics over time and space.This work was supported by the European Research Council (ERC-617457- PHYLOCANCER awarded to D.P.) and by the Spanish Ministry of Economy and Competitiveness—MINECO (BFU2015-63774-P awarded to D.P.). D.P. receives further support from Xunta de Galicia. J.M.A. is currently supported by an AXA Research Fund Postdoctoral Fellowship. J.M.C.-T. is supported by Grant PI15/01501-FEDER from the Instituto de Salud Carlos III, Ministry of Science, Innovation and Universities, SpainS

    Prevalence of autism spectrum disorder in the centro region of Portugal: A population based study of school age children within the ASDEU project

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    Introduction: Accurate prevalence estimates for Autism Spectrum Disorder (ASD) are fundamental to adequately program medical and educational resources for children. However, estimates vary globally and across Europe, and it is therefore wise to conduct epidemiological studies in defined geo-cultural contexts. Methods: We used a population screening approach to estimate the prevalence of ASD in the Centro region of Portugal, using a harmonized protocol as part of the Autism Spectrum Disorders in the European Union (ASDEU) project. Results: The overall prevalence was estimated at 0.5% (95% CI 0.3–0.7), higher in schools with Autism Units (3.3%, 95%CI 2.7–3.9) than in regular schools (0.3%, 95% CI 0.1–0.5) or schools with Multiple Disability Units (0.3%, 95% CI 0.04–0.6). Discussion: The results indicate that the diagnosis of ASD is followed by the most effective educational policies in Centro Region. The variability in prevalence estimates across the different regions from the ASDEU project, and globally, is discussed.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio

    Clinical and genetic characterization of patients with eye diseases included in the Spanish Rare Diseases Patient Registry

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    ABSTRACT: BACKGROUND: The low prevalence of rare diseases poses a significant challenge in advancing their understanding. This study aims to delineate the clinical and genetic characteristics of patients with rare eye diseases (RED) enrolled in the Spanish Rare Diseases Patient Registry. METHODS: A total of 864 patients from the registry database were included. Diseases were categorized into inherited retinal dystrophies (n=688); anterior segment diseases (n=48); congenital malformations (n=27); and syndromic diseases with ocular involvement including muscular (n=46), neurological (n=34), or metabolic (n=13); inflammatory diseases (n=4); and tumors (n=4). Data on visual acuity (VA) and/or visual field (VF), symptoms and signs, concurrent diseases in syndromic cases, age of onset and at diagnosis, affected genes, disability rating, inability to work and dependency grade recognition were collected. RESULTS: A mean diagnostic delay of 7 years from symptom onset was observed. Commonly reported symptoms included photophobia, night blindness, and progressive vision loss (≥57% of patients). Cataract was the most prevalent secondary disease (46%), with pseudophakia being the most common ocular surgery (26%). Hearing loss and cardiovascular diseases were the most prevalent concurrent systemic diseases (≥13%). Certificates of disability, incapacity for work, and dependency were held by 87%, 42%, and 19% of patients, respectively. Among the 719 patients with available VA data, 193 (27%) were blind, and 188 (26%) had moderate to severe visual impairment. Over half of the patients (54%) exhibited VF defects, and 216 (25%) had concentric contraction ≤5° or abolished VF. Most had genetic diseases with autosomal recessive (55%), autosomal dominant (30%), X-linked (9%), and mitochondrial (6%) patterns. One patient had mutations in both recessive USH2A and dominant RHO genes simultaneously. Of the 656 patients (75.7%) who underwent genetic testing, only 461 (70.3%) received a positive result (pathogenic or likely pathogenic mutations explaining the phenotype). We found 62 new gene variants related to RED not previously reported in databases of genetic variants related to specific phenotypes. CONCLUSIONS: This study delineates the clinical and genotypic profiles of RED in Spain. Genetic diseases, particularly retinal disorders, predominate, but a significant proportion of affected patients remain genetically undiagnosed, hindering potential gene therapy endeavors. Despite notable improvements in reducing diagnosis delays, it is still remarkable. RED frequently lead to disability and blindness among young populations

    Simplified Interval Observer Scheme: A New Approach for Fault Diagnosis in Instruments

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    There are different schemes based on observers to detect and isolate faults in dynamic processes. In the case of fault diagnosis in instruments (FDI) there are different diagnosis schemes based on the number of observers: the Simplified Observer Scheme (SOS) only requires one observer, uses all the inputs and only one output, detecting faults in one detector; the Dedicated Observer Scheme (DOS), which again uses all the inputs and just one output, but this time there is a bank of observers capable of locating multiple faults in sensors, and the Generalized Observer Scheme (GOS) which involves a reduced bank of observers, where each observer uses all the inputs and m-1 outputs, and allows the localization of unique faults. This work proposes a new scheme named Simplified Interval Observer SIOS-FDI, which does not requires the measurement of any input and just with just one output allows the detection of unique faults in sensors and because it does not require any input, it simplifies in an important way the diagnosis of faults in processes in which it is difficult to measure all the inputs, as in the case of biologic reactors

    The Spanish toxic oil syndrome 20 years after its onset: a multidisciplinary review of scientific knowledge.

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    In 1981, in Spain, the ingestion of an oil fraudulently sold as olive oil caused an outbreak of a previously unrecorded condition, later known as toxic oil syndrome (TOS), clinically characterized by intense incapacitating myalgias, marked peripheral eosinophilia, and pulmonary infiltrates. Of the 20,000 persons affected, approximately 300 died shortly after the onset of the disease and a larger number developed chronic disease. For more than 15 years, a scientific committee supported by the World Health Organization's Regional Office for Europe and by the Institute of Health Carlos III in Madrid has guided investigation intended to identify the causal agent(s), to assess toxicity and mode of action, to establish the pathogenesis of the disease, and to detect late consequences. This report summarizes advances in research on this front. No late mortality excess has been detected. Among survivors, the prevalence of some chronic conditions (e.g., sclerodermia, neurologic changes) is high. Attempts to reproduce the condition in laboratory animals have been unsuccessful, and no condition similar to TOS has been reported in the scientific literature. Laboratory findings suggest an autoimmune mechanism for TOS, such as high levels of seric soluble interleukin-2 receptor. Epidemiologic studies integrated with chemical analyses of case-related oils have shown that the disease is strongly associated with the consumption of oils containing fatty acid esters of 3-(N-phenylamino)-1,2-propanediol (PAP). These chemicals have also been found in oils synthesized under conditions simulating those hypothesized to have occurred when the toxic oil was produced in 1981. Whether PAP esters are simply markers of toxicity of oils or have the capability to induce the disease remains to be elucidated

    Neurologic outcomes of toxic oil syndrome patients 18 years after the epidemic.

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    Toxic oil syndrome (TOS) resulted from consumption of rapeseed oil denatured with 2% aniline and affected more than 20,000 persons. Eighteen years after the epidemic, many patients continue to report neurologic symptoms that are difficult to evaluate using conventional techniques. We conducted an epidemiologic study to determine whether an exposure to toxic oil 18 years ago was associated with current adverse neurobehavioral effects. We studied a case group of 80 adults exposed to toxic oil 18 years ago and a referent group of 79 adult age- and sex-frequency-matched unexposed subjects. We interviewed subjects for demographics, health status, exposures to neurotoxicants, and responses to the Kaufman Brief Intelligence Test (K-BIT), Programa Integrado de Exploracion Neuropsicologica (PIEN), and Goldberg depression questionnaires and administered quantitative neurobehavioral and neurophysiologic tests by computer or trained nurses. The groups did not differ with respect to educational background or other critical variables. We examined associations between case and referent groups and the neurobehavioral and neurophysiologic outcomes of interest. Decreased distal strength of the dominant and nondominant hands and increased vibrotactile thresholds of the fingers and toes were significantly associated with exposure to toxic oil. Finger tapping, simple reaction time latency, sequence B latency, symbol digit latency, and auditory digit span were also significantly associated with exposure. Case subjects also had statistically significantly more neuropsychologic symptoms compared with referents. Using quantitative neurologic tests, we found significant adverse central and peripheral neurologic effects in a group of TOS patients 18 years after exposure to toxic oil when compared with a nonexposed referent group. These effects were not documented by standard clinical examination and were found more frequently in women

    Phylogenetic Relationships among Deep-Sea and Chemosynthetic Sea Anemones: Actinoscyphiidae and Actinostolidae (Actiniaria: Mesomyaria)

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    Sea anemones (Cnidaria, Actiniaria) are present in all marine ecosystems, including chemosynthetic environments. The high level of endemicity of sea anemones in chemosynthetic environments and the taxonomic confusion in many of the groups to which these animals belong makes their systematic relationships obscure. We use five molecular markers to explore the phylogenetic relationships of the superfamily Mesomyaria, which includes most of the species that live in chemosynthetic, deep-sea, and polar sea habitats and to test the monophyly of the recently defined clades Actinostolina and Chemosynthina. We found that sea anemones of chemosynthetic environments derive from at least two different lineages: one lineage including acontiate deep-sea taxa and the other primarily encompassing shallow-water taxa

    An Earthworm Riddle: Systematics and Phylogeography of the Spanish Lumbricid Postandrilus

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    As currently defined, the genus Postandrilus Qui and Bouché, 1998, (Lumbricidae) includes six earthworm species, five occurring in Majorca (Baleares Islands, western Mediterranean) and another in Galicia (NW Spain). This disjunct and restricted distribution raises some interesting phylogeographic questions: (1) Is Postandrilus distribution the result of the separation of the Baleares-Kabylies (BK) microplate from the proto-Iberian Peninsula in the Late Oligocene (30-28 Mya)--vicariant hypothesis? (2) Did Postandrilus diversify in Spain and then colonize the Baleares during the Messinian salinity crisis (MSC) 5.96-5.33 Mya--dispersal hypothesis? (3) Is the distribution the result of a two-step process--vicariance with subsequent dispersal?To answer these questions and assess Postandrilus evolutionary relationships and systematics, we collected all of the six Postandrilus species (46 specimens - 16 locations) and used Aporrectodea morenoe and three Prosellodrilus and two Cataladrilus species as the outgroup. Regions of the nuclear 28S rDNA and mitochondrial 16S rDNA, 12S rDNA, ND1, COII and tRNA genes (4,666 bp) were sequenced and analyzed using maximum likelihood and Bayesian methods of phylogenetic and divergence time estimation. The resulting trees revealed six new Postandrilus species in Majorca that clustered with the other five species already described. This Majorcan clade was sister to an Iberian clade including A. morenoe (outgroup) and Postandrilus bertae. Our phylogeny and divergence time estimates indicated that the split between the Iberian and Majorcan Postandrilus clades took place 30.1 Mya, in concordance with the break of the BK microplate from the proto-Iberian Peninsula, and that the present Majorcan clade diversified 5.7 Mya, during the MSC.Postandrilus is highly diverse including multiple cryptic species in Majorca. The genus is not monophyletic and invalid as currently defined. Postandrilus is of vicariant origin and its radiation began in the Late Oligocene
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