89 research outputs found

    Relative and absolute density estimates of land planarians (Platyhelminthes, Tricladida) in urban rainforest patches

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    Land planarians (Platyhelminthes) are likely important components of the soil cryptofauna, although relevant aspects of their ecology such as their density remain largely unstudied. We investigated absolute and relative densities of flatworms in three patches of secondary Brazilian Atlantic rainforest in an urban environment. Two methods of sampling were carried out, one consisting of 90 hours of active search in delimited plots covering 6,000 m² over a year, and the other consisting of leaf litter extraction from a 60 m² soil area, totaling 480‑600 l leaf litter. We found 288 specimens of 16 species belonging to the genera Geobia, Geoplana, Issoca, Luteostriata, Obama, Paraba, Pasipha, Rhynchodemus, Xerapoa, and the exotic species Bipalium kewense and Dolichoplana striata. Specimens up to 10 mm long were mostly sampled only with the leaf litter extraction method. Absolute densities, calculated from data obtained with leaf litter extraction, ranged between 1.25 and 2.10 individuals m‑². These values are 30 to 161 times higher than relative densities, calculated from data obtained by active search. Since most common sampling method used in land planarian studies on species composition and faunal inventories is active search for a few hours in a locality, our results suggest that small species might be overlooked. It remains to be tested whether similar densities of this cryptofauna are also found in primary forests

    A new Peruvian land planarian species of the genus Gigantea (Platyhelminthes, Tricladida, Geoplanidae)

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    A new species of Geoplaninae land planarian from south Peru, Gigantea urubambensis sp. nov., is described. The most outstanding features of the new species are the very dorsal location of the testes, between the dorsal diagonal and the supra-intestinal parenchymatic muscle layers; a penis papilla projecting from the roof of the male atrium and acentrally traversed by the ejaculatory duct; and the absence of glandular ridges on the penis papilla.Fil: Negrete, Lisandro Hector Luis. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Brusa, Francisco. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Carbayo, Fernando. Universidade de Sao Paulo; Brasi

    Micro-computed tomography scan and virtual histological slide data for the land planarian Obama otavioi (Platyhelminthes)

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    Abstract\ud \ud Background\ud We investigated whether images obtained through X-ray micro-computed tomography (μCT) can be used in conjunction with traditional methods for morphological studies of soft-bodied land planarians. μCT is non-invasive and provides true-to-scale three-dimensional imagery at high resolution. We compared μCT-based images of a recently described land planarian species of Obama otavioi (Platyhelminthes) with those obtained from light microphotography of histological sections, most of which were also digitized at high magnification.\ud \ud \ud Findings\ud The specimens studied were collected in 2012. Subsequent μCT-based images of the stained body of a paratype show nearly all morphological features provided by traditional histology, with the exception of particularly minute structures, smaller than 5 μm, such as the sensory pits and single muscle fibers, which are best visible on traditional histological sections. Because the technique is non-destructive, the scanned specimen is preserved without damage. The raw and derivative μCT data and virtual histological sections are freely available in GigaDB.\ud \ud \ud Conclusions\ud The μCT datasets of these stained soft-bodied organisms reveal images of external and internal structures that support previous taxonomic studies. This technique can be particularly important for non-destructively revealing internal details of whole museum specimens at a faster rate than histology alone. High-resolution virtual histological slides also allow further searches for new, previously unstudied morphological features. The use of X-ray equipment with higher resolution can enable smaller sensory organ and muscle fiber details to be seen. The image sets, μCT-based images and digitized histological slides can be disseminated without the constraints of specimen loans.Instituto de Botânica da Secretaria do Meio Ambiente do Estado de São\ud Paulo licensed the fieldwork. Marcos Santos Silva, Ana Laura Almeida and\ud Amanda Cseh helped with sampling. Ana Cristina Vasconcellos made\ud histological sections. José Ernesto Belizario and Beatriz Viana dos Santos\ud provided support with obtaining virtual histological slides (USP Proc.\ud 2012.1.17660.1.0). Beka Buckman kindly read the manuscript for English\ud improvement. São Paulo Research Foundation (FAPESP, Proc. 2014/13661-8)\ud provided financial support to FC. This work was also supported by the\ud Museum of Comparative Zoology, Harvard University

    A study on the etymology of the scientific names given to planarians (Platyhelminthes, Tricladida) by Ernest Marcus’ school

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    Leading zoologist and taxonomist Ernest Marcus (1893-1968) and his school described numerous new invertebrate taxa, including planarians, or triclads (Platyhelminthes). These authors rarely provided the etymology of names for the new taxa. In this paper, the etymology of 149 names of genera and specific epithets of planarians lacking etymology (or honoring people) is investigated. The etymology of most names was retrieved from original descriptive papers and from Eudóxia Maria Froehlich’s recollections, a fellow of Marcus’ school. It was discovered that the names were usually freely derived from words of the language spoken in the country where the species was found. Some names were motivated by an aspect of the biology of the species. Other names honored people or are arbitrary. The etymology of 19 names could not be retrieved and are only suggested. The origin of another 19 names could not be discovered, nor even their meaning. Knowing the etymology makes it easier to memorize a name and it is a way to preserve the historical and emotional aspects of the authors. Through the retrieved etymologies, the personality of Marcus can also be glimpsed

    Land planarians (Platyhelminthes) also prey on web-building spiders

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    Although spiders and land planarians constitute diverse groups of terrestrial predators, interactions between them are still unknown. Here, we describe a predatory event of a land planarian (Choeradoplana cf. gladismariae) on a web-building spider (Helvibis longicauda) in the Brazilian Atlantic Forest. The prey was constricted and covered with sticky mucus while remaining on its web trying to protect its egg sac. The event was observed in the middle-end afternoon at ca. 1.80 m height. Our observation broadens the scope of possible natural enemies of web-building spiders and the prey items of land planarians. It also indicates that these organisms can capture and overpower dangerous predatory arthropods, suggesting that even complex three-dimensional sticky webs can be ineffective against the attack of land planarians. Finally, we also show that land planarians can exhibit a flexible foraging strategy, exploiting the environment during the day and at higher heights from the ground. Our observation opens new possibilities involving focal observations and experiments using spiders and land planarians as models in predator-prey research

    The ERICE-score: the new native cardiovascular score for the low-risk and aged mediterranean population of Spain

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    [Abstract] Introduction and objectives. In Spain, data based on large population-based cohorts adequate to provide an accurate prediction of cardiovascular risk have been scarce. Thus, calibration of the EuroSCORE and Framingham scores has been proposed and done for our population. The aim was to develop a native risk prediction score to accurately estimate the individual cardiovascular risk in the Spanish population. Methods. Seven Spanish population-based cohorts including middle-aged and elderly participants were assembled. There were 11 800 people (6387 women) representing 107 915 person-years of follow-up. A total of 1214 cardiovascular events were identified, of which 633 were fatal. Cox regression analyses were conducted to examine the contributions of the different variables to the 10-year total cardiovascular risk. Results. Age was the strongest cardiovascular risk factor. High systolic blood pressure, diabetes mellitus and smoking were strong predictive factors. The contribution of serum total cholesterol was small. Antihypertensive treatment also had a significant impact on cardiovascular risk, greater in men than in women. The model showed a good discriminative power (C-statistic = 0.789 in men and C = 0.816 in women). Ten-year risk estimations are displayed graphically in risk charts separately for men and women. Conclusions. The ERICE is a new native cardiovascular risk score for the Spanish population derived from the background and contemporaneous risk of several Spanish cohorts. The ERICE score offers the direct and reliable estimation of total cardiovascular risk, taking in consideration the effect of diabetes mellitus and cardiovascular risk factor management. The ERICE score is a practical and useful tool for clinicians to estimate the total individual cardiovascular risk in Spain.[Resumen] Introducción y objetivos. En España no existen unas cohortes poblacionales suficientemente grandes para hacer predicciones precisas del riesgo cardiovascular. Las ecuaciones de Framingham y EuroSCORE calibradas son las más utilizadas en España. El objetivo es desarrollar la primera ecuación de predicción autóctona para estimar con precisión el riesgo cardiovascular individual en España. Métodos. Análisis conjunto de siete cohortes españolas de población de mediana edad y anciana. La población del estudio —11.800 personas (6.387 mujeres)— aportó un total de 107.915 personas-año de seguimiento y 1.214 eventos cardiovasculares (633 de ellos, mortales). Se efectuó un análisis de regresión de Cox para examinar la contribución de los diferentes factores al riesgo de cualquier evento cardiovascular (mortal y no mortal). Resultados. La edad fue el principal factor de riesgo de eventos cardiovasculares. La presión arterial sistólica, la diabetes mellitus, el tabaquismo y el tratamiento antihipertensivo fueron factores predictivos fuertemente asociados con el riesgo cardiovascular. En cambio, la contribución del colesterol total sérico fue pequeña, especialmente en los mayores de 70 años. El modelo final de riesgo mostró un buen poder discriminatorio (estadístico C = 0,789 en varones y C = 0,816 en mujeres). Conclusiones. ERICE es una nueva ecuación de riesgo cardiovascular genuinamente española obtenida a partir del riesgo concurrente individual de los participantes en varias cohortes. La ecuación ERICE ofrece una estimación directa y fiable del riesgo cardiovascular total teniendo en cuenta factores como la diabetes mellitus y el tratamiento farmacológico de los factores de riesgo cardiovascular, habitualmente no incluidos en otras ecuaciones.Instituto de Salud Carlos III; G03/065Instituto de Salud Carlos III; PI05/1464Instituto de Salud Carlos III; RD06/0014/001

    Comparing algorithms for automated vessel segmentation in computed tomography scans of the lung: the VESSEL12 study

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    The VESSEL12 (VESsel SEgmentation in the Lung) challenge objectively compares the performance of different algorithms to identify vessels in thoracic computed tomography (CT) scans. Vessel segmentation is fundamental in computer aided processing of data generated by 3D imaging modalities. As manual vessel segmentation is prohibitively time consuming, any real world application requires some form of automation. Several approaches exist for automated vessel segmentation, but judging their relative merits is difficult due to a lack of standardized evaluation. We present an annotated reference dataset containing 20 CT scans and propose nine categories to perform a comprehensive evaluation of vessel segmentation algorithms from both academia and industry. Twenty algorithms participated in the VESSEL12 challenge, held at International Symposium on Biomedical Imaging (ISBI) 2012. All results have been published at the VESSEL12 website http://vessel12.grand-challenge.org. The challenge remains ongoing and open to new participants. Our three contributions are: (1) an annotated reference dataset available online for evaluation of new algorithms; (2) a quantitative scoring system for objective comparison of algorithms; and (3) performance analysis of the strengths and weaknesses of the various vessel segmentation methods in the presence of various lung diseases.Rudyanto, RD.; Kerkstra, S.; Van Rikxoort, EM.; Fetita, C.; Brillet, P.; Lefevre, C.; Xue, W.... (2014). Comparing algorithms for automated vessel segmentation in computed tomography scans of the lung: the VESSEL12 study. Medical Image Analysis. 18(7):1217-1232. doi:10.1016/j.media.2014.07.003S1217123218

    Impact of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients: A nationwide study in Spain

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    Objective To assess the effect of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients in Spain. Settings The initial flood of COVID-19 patients overwhelmed an unprepared healthcare system. Different measures were taken to deal with this overburden. The effect of these measures on neurosurgical patients, as well as the effect of COVID-19 itself, has not been thoroughly studied. Participants This was a multicentre, nationwide, observational retrospective study of patients who underwent any neurosurgical operation from March to July 2020. Interventions An exploratory factorial analysis was performed to select the most relevant variables of the sample. Primary and secondary outcome measures Univariate and multivariate analyses were performed to identify independent predictors of mortality and postoperative SARS-CoV-2 infection. Results Sixteen hospitals registered 1677 operated patients. The overall mortality was 6.4%, and 2.9% (44 patients) suffered a perioperative SARS-CoV-2 infection. Of those infections, 24 were diagnosed postoperatively. Age (OR 1.05), perioperative SARS-CoV-2 infection (OR 4.7), community COVID-19 incidence (cases/10 5 people/week) (OR 1.006), postoperative neurological worsening (OR 5.9), postoperative need for airway support (OR 5.38), ASA grade =3 (OR 2.5) and preoperative GCS 3-8 (OR 2.82) were independently associated with mortality. For SARS-CoV-2 postoperative infection, screening swab test <72 hours preoperatively (OR 0.76), community COVID-19 incidence (cases/10 5 people/week) (OR 1.011), preoperative cognitive impairment (OR 2.784), postoperative sepsis (OR 3.807) and an absence of postoperative complications (OR 0.188) were independently associated. Conclusions Perioperative SARS-CoV-2 infection in neurosurgical patients was associated with an increase in mortality by almost fivefold. Community COVID-19 incidence (cases/10 5 people/week) was a statistically independent predictor of mortality. Trial registration number CEIM 20/217
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