668 research outputs found
Seasonal wetlands in the Pacific coast of Costa Rica and Nicaragua: environmental characterisation and conservation state.
Seasonal wetlands in the Pacific coast of Costa Rica and Nicaragua: environmental characterisation and conservation status On the Pacific coast of Nicaragua and Costa Rica, rainfall patterns and clay-rich soils allow the development of extensive wetlands. These environments constitute unique habitats for the maintenance of aquatic biodiversity and provide significant ecological services to the surrounding seasonal dry forest. Despite these benefits, wetlands have been severely reduced in the last four decades, and little information is available on their biology and current conservation status. Here, we describe the main limnological traits of 30 sites representing different types of wetlands from four distinct physiographic regions: Tempisque River Lower Basin; Tempisque River Middle Basin; Delta del Estero Real River; and the Oriental Region of Nicaragua. At each site, samples were taken at the beginning (infilling phase), middle (maximum flooded areas) and end (desiccation phase) of the 2010 hydrological cycle. We analysed a set of water parameters (depth, temperature, pH, conductivity, dissolved oxygen, major ions and nutrient concentrations) and biological parameters (shoreline vegetation, chlorophyll a, macrophyte cover) and assessed the conservation status of wetlands using the Index of the State of Conservation of Shallow Lentic Ecosystems (ECELS). In most sites, the water was relatively clear with near basic pH-values, low conductivity, and low levels of dissolved oxygen, nitrates, nitrites, phosphates and sulphates. Chlorophyll a and alkalinity varied through the season and among regions. Ion concentrations were generally low in most wetlands except for those close to estuarine and marine coastal areas. A total of 49 taxa of aquatic plants were found in the study sites, the most common being the emergent Typha domingensis and Thalia geniculata, and the floating Pistia stratiotes and Eichhornia crassipes. Wetlands within the same region exhibited We great similarity in their aquatic plant communities but not necessarily in their physicochemical attributes. According to the ECELS index, wetlands could be ranked from medium to good quality, although most of them are threatened by anthropogenic impacts, including those protected at Delta del Estero Real Nature Reserve (Nicaragua) and Palo Verde National Park (Costa Rica). On the Pacific coast of Nicaragua and Costa Rica, rainfall patterns and clay-rich soils allow the development of extensive wetlands. These environments constitute unique habitats for the maintenance of aquatic biodiversity and provide significant ecological services to the surrounding seasonal dry forest. Despite these benefits, wetlands have been severely reduced in the last four decades, and little information is available on their biology and current conservation status. Here, we describe the main limnological traits of 30 sites representing different types of wetlands from four distinct physiographic regions: Tempisque River Lower Basin; Tempisque RiverMiddle Basin; Delta del Estero Real River; and the Oriental Region of Nicaragua. At each site, samples were taken at the beginning (infilling phase), middle (maximum flooded areas) and end (desiccation phase) of the 2010 hydrological cycle. We analysed a set of water parameters (depth, temperature, pH, conductivity, dissolved oxygen, major ions and nutrient concentrations) and biological parameters (shoreline vegetation, chlorophyll a, macrophyte cover) and assessed the conservation status of wetlands using the Index of the State of Conservation of Shallow Lentic Ecosystems (ECELS). In most sites, the water was relatively clear with near basic pH-values, low conductivity, and low levels of dissolved oxygen, nitrates, nitrites, phosphates and sulphates. Chlorophyll a and alkalinity varied through the season and among regions. Ion concentrations were generally low in most wetlands except for those close to estuarine and marine coastal areas. A total of 49 taxa of aquatic plants were found in the study sites, the most common being the emergent Typha domingensis and Thalia geniculata, and the floating Pistia stratiotes and Eichhornia crassipes. Wetlands within the same region exhibited great similarity in their aquatic plant communities but not necessarily in their physicochemical attributes. According to the ECELS index, wetlands could be ranked from medium to good quality, although most of them are threatened by anthropogenic impacts, including those protected at Delta del Estero Real Nature Reserve (Nicaragua) and Palo Verde National Park (Costa Rica)
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Levels of Lead in Breast Milk and Their Relation to Maternal Blood and Bone Lead Levels at One Month Postpartum.
Despite the many well-recognized benefits of breast-feeding for both mothers and infants, detectable levels of lead in breast milk have been documented in population studies of women with no current environmental or occupational exposures. Mobilization of maternal bone lead stores has been suggested as a potential endogenous source of lead in breast milk. We measured lead in breast milk to quantify the relation between maternal blood and bone lead levels and breast-feeding status (exclusive vs. partial) among 310 lactating women in Mexico City, Mexico, at 1 month postpartum. Umbilical cord and maternal blood samples were collected at delivery. Maternal breast milk, blood, and bone lead levels were obtained at 1 month postpartum. Levels of lead in breast milk ranged from 0.21 to 8.02 microg/L (ppb), with a geometric mean (GM) of 1.1 microg/L; blood lead ranged from 1.8 to 29.9 microg/dL (GM = 8.4 microg/dL); bone lead ranged from less than 1 to 67.2 microg/g bone mineral (patella) and from less than 1 to 76.6 microg/g bone mineral (tibia) at 1 month postpartum. Breast milk lead was significantly correlated with umbilical cord lead [Spearman correlation coefficient (r) = 0.36, p less than 0.0001] and maternal blood lead (r= 0.38, p less than 0.0001) at delivery and with maternal blood lead (r = 0.42, p less than 0.0001) and patella lead (r= 0.15, p less than 0.01) at 1 month postpartum. Mother's age, years living in Mexico City, and use of lead-glazed ceramics, all predictive of cumulative lead exposure, were not significant predictors of breast milk lead levels. Adjusting for parity, daily dietary calcium intake (milligrams), infant weight change (grams), and breast-feeding status (exclusive or partial lactation), the estimated effect of an interquartile range (IQR) increase in blood lead (5.0 microg/dL) was associated with a 33% increase in breast milk lead [95% confidence interval (CI), 24 to 43%], whereas an IQR increase in patella lead (20 microg/g) was associated with a 14% increase in breast milk lead (95% CI, 5 to 25%). An IQR increase in tibia lead (12.0 microg/g) was associated with a 5% increase in breast milk lead (95% CI, -3% to 14%). Our results indicate that even among a population of women with relatively high lifetime exposure to lead, levels of lead in breast milk are low, influenced both by current lead exposure and by redistribution of bone lead accumulated from past environmental exposures
Dislocation Emission around Nanoindentations on a (001) fcc Metal Surface Studied by STM and Atomistic Simulations
We present a combined study by Scanning Tunneling Microscopy and atomistic
simulations of the emission of dissociated dislocation loops by nanoindentation
on a (001) fcc surface. The latter consist of two stacking-fault ribbons
bounded by Shockley partials and a stair-rod dislocation. These dissociated
loops, which intersect the surface, are shown to originate from loops of
interstitial character emitted along the directions and are usually
located at hundreds of angstroms away from the indentation point. Simulations
reproduce the nucleation and glide of these dislocation loops.Comment: 10 pages, 4 figure
Óptimos económicos en corderos pelibuey engordados en corral
Los óptimos técnico (OT) y económico (OE) fueron estimados durante ocho semanas en 24 corderos Pelibuey machos (PVI 20+-0.52 k y edad 75+-15 d). Los valores del OT para alimentación y número de semanas fueron 107.40 k y 34.3, con ganancias de 1 147.61, y los del OE fueron 95.1 k y 34.26, con ganancias de 1 148.13. El peso máximo in vivo no necesariamente significa un máximo ingreso neto
Determination of the atmospheric neutrino fluxes from experimental data
The precise knowledge of the atmospheric neutrino fluxes is a key ingredient
in the interpretation of the results from any atmospheric neutrino experiment.
In the standard atmospheric neutrino data analysis, these fluxes are
theoretical inputs obtained from sophisticated numerical calculations. In this
contribution we present an alternative approach to the determination of the
atmospheric neutrino fluxes based on the direct extraction from the
experimental data on neutrino event rates.Comment: 4 pages, 3 figs, to appear in the proceedings of the Multi-Messenger
Approach to High-Energy Gamma-Ray Sources Conference, Barcelona July 200
Modelos de crecimiento y producción en España: historia, ejemplos contemporáneos y perspectivas
En el presente trabajo se presenta una revisión sobre los modelos forestales desarrollados en España durante los últimos años, tanto para la producción maderable como no maderable y, para la dinámica de los bosques (regeneración, mortalidad). Se presentan modelos tanto de rodal completo como de clases diamétricas y de árbol individual. Los modelos desarrollados hasta la fecha se han desarrollado a partir de datos procedentes de parcelas permanentes, ensayos y el Inventario Forestal Nacional. En el trabajo se muestran los diferentes submodelos desarrollados hasta la fecha, así como las plataformas informáticas que permiten utilizar dichos modelos. Se incluyen las principales perspectivas
de desarrollo de la modelización forestal en España.In this paper we present a review of forest models developed in Spain in recent years for both timber and non timber production and forest dynamics (regeneration, mortality). Models developed are whole stand, size (diameter) class and individual-tree. The models developed to date have been developed using data from permanent plots, experimental
sites and the National Forest Inventory. In this paper we show the different sub-models developed so far and the friendly use software. Main perspectives of forest modeling in Spain are presented.The models described in this paper were funded by
different regional, national and European projects, and
some of them were elaborated by the authors. This
work was funded by the Spanish Government by the
SELVIRED network (code AGL2008-03740) and the
strategic project «Restauración y Gestión Forestal»
(code PSE-310000-2009-4)
Imported malaria in pregnancy in Madrid
<p>Abstract</p> <p>Background</p> <p>Malaria in pregnancy is associated with maternal and foetal morbidity and mortality in endemic areas, but information on imported cases to non-endemic areas is scarce.</p> <p>The aim of this study was to describe the clinical and epidemiological characteristics of malaria in pregnancy in two general hospitals in Madrid, Spain.</p> <p>Methods</p> <p>Retrospective descriptive study of laboratory-confirmed malaria in pregnant women at the Fuenlabrada University Hospital and the Príncipe de Asturias University Hospital, in Madrid, over a six- and 11-year period, respectively. Relevant epidemiological, clinical and laboratory data was obtained from medical records.</p> <p>Results</p> <p>There were 19 pregnant women among 346 malaria cases (5.4%). The average age was 27 years. The gestational age (trimester) was: 53% 3<sup>rd</sup>, 31% 1st, 16% 2<sup>nd</sup>. All but one were multigravidae. Three were HIV positive. All were sub-Saharan immigrants: two were recently arrived immigrants and seventeen (89%) had visited friends and relatives. None had taken prophylaxis nor seeked pre-travel advice. Presentation: 16 symptomatic patients (fever in fourteen, asthenia in two), three asymptomatic. Median delay in diagnosis: 7.5 days. Laboratory tests: anaemia (cut off Hb level 11 g/dl) 78.9% (mild 31.6%, moderate 31.6%, severe 15.8%) thrombocytopaenia 73.7%, hypoglycaemia 10.5%. All cases were due to <it>Plasmodium falciparum</it>, one case of hyperparasitaemia. Quinine + clindamycin prescribed in 84%. Outcomes: no severe maternal complications or deaths, two abortions, fifteen term pregnancies, no low-birth-weight newborns, two patients were lost to follow-up.</p> <p>Conclusions</p> <p>Though cases of malaria in pregnancy are uncommon, a most at risk group is clearly defined: young sub-Saharan mothers visiting friends and relatives without pre-travel counselling and recently-arrived immigrants. The most common adverse maternal and foetal effects were anaemia and stillbirth. Given that presentation can be asymptomatic, malaria should always be considered in patients with unexplained anaemia arriving from endemic areas. These findings could help Maternal Health programme planners and implementers to target preventive interventions in the immigrant population and should create awareness among clinicians.</p
Distinct GSDMB protein isoforms and protease cleavage processes differentially control pyroptotic cell death and mitochondrial damage in cancer cells
Gasdermin (GSDM)-mediated pyroptosis is functionally involved in multiple diseases, but Gasdermin-B (GSDMB) exhibit cell death-dependent and independent activities in several pathologies including cancer. When the GSDMB pore-forming N-terminal domain is released by Granzyme-A cleavage, it provokes cancer cell death, but uncleaved GSDMB promotes multiple pro-tumoral effects (invasion, metastasis, and drug resistance). To uncover the mechanisms of GSDMB pyroptosis, here we determined the GSDMB regions essential for cell death and described for the first time a differential role of the four translated GSDMB isoforms (GSDMB1-4, that differ in the alternative usage of exons 6-7) in this process. Accordingly, we here prove that exon 6 translation is essential for GSDMB mediated pyroptosis, and therefore, GSDMB isoforms lacking this exon (GSDMB1-2) cannot provoke cancer cell death. Consistently, in breast carcinomas the expression of GSDMB2, and not exon 6-containing variants (GSDMB3-4), associates with unfavourable clinical-pathological parameters. Mechanistically, we show that GSDMB N-terminal constructs containing exon-6 provoke cell membrane lysis and a concomitant mitochondrial damage. Moreover, we have identified specific residues within exon 6 and other regions of the N-terminal domain that are important for GSDMB-triggered cell death as well as for mitochondrial impairment. Additionally, we demonstrated that GSDMB cleavage by specific proteases (Granzyme-A, Neutrophil Elastase and caspases) have different effects on pyroptosis regulation. Thus, immunocyte-derived Granzyme-A can cleave all GSDMB isoforms, but in only those containing exon 6, this processing results in pyroptosis induction. By contrast, the cleavage of GSDMB isoforms by Neutrophil Elastase or caspases produces short N-terminal fragments with no cytotoxic activity, thus suggesting that these proteases act as inhibitory mechanisms of pyroptosis. Summarizing, our results have important implications for understanding the complex roles of GSDMB isoforms in cancer or other pathologies and for the future design of GSDMB-targeted therapies.This study has been supported by the Ministerio de Ciencia, Innovación y Universidades, Agencia Estatal de Investigación (MICINN-AEI, PID2019-104644RB-I00, PDC2022-133252-I00) -GMB-, (PID2021-126625OB-I00-MCIN/AEI/10.13039/501100011033 FEDER, EU.2022- and DTS20-00024 -ISCIII-) -PGP-, the Instituto de Salud Carlos III (CIBERONC, CB16/12/00295 -GMB- and CB16/12/00241 -JA-, and AC21_2/00020 ERA PerMed ERA-NET, PMP22/00054 Immune4ALL Personalized Medicine -GMB-, cofunded by NextGenerationEU), I “Semilla” CIBERONC-GEICAM Grant -GMB- and the AECC Scientific Foundation (FCAECC PROYE19036MOR and GCTRA18014MATI -GMB-), the National Institutes of Health (NIH, USA) (R01-DK123475) -J-KK- and it has been also supported by a startup fund to -J-KK- from the Ohio State University, the College of Medicine, Department of Surgery. DS contract is funded by CIBERONC partly supported by FEDER funds. SO is funded by the FCAECC (POSTD20028OLTR), SC is funded by the MICINN-AEI PRE2020-095658
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