122 research outputs found

    Grazing improves habitat suitability for many ground foraging birds in Mediterranean wooded grasslands

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    Wooded grasslands, usually grazed, cover vast areas in Southern Europe and Northern Africa. They host rich resident bird communities and, in winter, receive large numbers of migrants from Central and Northern European woodlands. Many species are partly or entirely dependent on ground foraging, and since in winter food is often the most limiting factor for birds, maintaining suitable ground habitat is crucial. To study how grazing influences suitability of winter ground habitat for birds, we carried out an experiment in a wooded grassland in Southern Iberia, whereby grazing was controlled in 12 purposely fenced two-hectare plots (4 x 15 sheep/ha, 4 x 3 sheep/ha and 4 x no grazing). We quantified ground habitat features, food abundance and intensity of use by ground-foraging birds in each of these 12 plots. In addition, we made focal observations of birds feeding on the ground and compared the habitat of 1m2 foraging patches with those of nearby control patches. We found that virtually all birds prefer to forage in patches with short ground vegetation and high food abundance. Measurements of these parameters in the experimental plots showed that while grazing shortens vegetation it decreases food availability, and thus has opposing effects on important determinants of habitat suitability. Nevertheless, the numbers of birds foraging in the plots indicate that, overall, grazing benefits the assemblage of ground-feeding birds, presumably because for most species the advantages of foraging in less cluttered habitats more than compensate the lower abundance of prey. However, arboreal bird species that make short foraging forays to the ground had lower numbers in grazed plots. Most bird species that forage on the ground benefited from grazing, and although they can forage under a broad range of grazing levels, some showed clear preferences along the gradient of grazing intensity. Such preferences should be taken into consideration by managers. In general, grazing should be maintained at a level sufficient to open up ground vegetation, increasing the area occupied by patches of short vegetation, in which almost all bird species prefer to forage. At moderate levels, grazing is thus a valuable management tool to promote winter bird habitat quality in Mediterranean wooded grasslands, while increasing the economic value of these threatened landscapes

    Methadone Intoxication in a Child: Toxic Encephalopathy?

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    Methadone is used in the treatment of opioid addiction. Acute intoxication can lead to severe consequences and can even be lethal. In several case reports and small series, a presumably toxic leukoencephalopathy is described resulting from inhalation of heroin. We present the case of a 3-year-old boy who ingested methadone accidentally. In a coma with acute obstructive hydrocephalus owing to massive cerebellar edema and supratentorial lesions, he was successfully treated with methylprednisolone and cerebrospinal fluid external drainage. To our knowledge, this is the first report of an encephalopathy associated with synthetic opioid intoxication

    Pseudo-homogeneous CSTR Simulation of a Fluidized Bed Reactor operating in condensed-mode including Sanchez-Lacombe n-hexane co-solubility effect predictions

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    Abstract This work explores the impact of the inert condensing agent (ICA) n-hexane in the production of Polyethylene via gasphase condensed mode bed reactor. The gas loaded to these reactors contains mainly ethylene, nitrogen and other reaction agents like hydrogen. But it also includes condensed inert agents like n-hexane. They have an important role in cooling down the bed of the reactor not only because they have a relevant heat capacity but primarily because they can be in a condensed state. As the gas-liquid mixture enters the reactor, the condensed liquid content vaporizes and removes latent heat that way allowing bigger productions. ICA's like hexane seem, in addition, to solubilize the ethylene gas in the amorphous polyethylene of the growing polymer phase (co-solubility effect) enabling even higher polymerization rates. The Sanchez-Lacombe equation of state have been successfully used in predicting the mentioned co-solubility effect of n-hexane in ethylene polymerization. Its lately computational predictions on such subject were used in the current work. This work simulates a reacting system composed by an ethylene/nitrogen/n-hexane gas phase in equilibrium with an ethylene/amorphous polyethylene/n-hexane polymer phase, using a pseudo-homogeneous steady-state CSTR approach. This system was evaluated at 7 bar ethylene, 1 bar nitrogen and within a range of 0.0 -1.0 bar n-hexane, with different operation conditions such as catalyst flowrates, inlet gas temperature and kinetic rate constants. The global results showed that from no hexane in reactor to a pressure of 0.1bar hexane there's a variation of polyethylene production of about 2% (n-hexane co-solubility effect). And as total pressure adds 0.1bar hexane, the polyethylene production variation approximately follows this trend; it is like this as far as inlet stream cooling capacity is not too high (declining temperature and, by extension, kinetics) that it subordinates the n-hexane co-solubility effect. Regarding reactor temperature, there are two distinct behaviours: if the reactor operates in a non-condensed mode (less than 0.4bar hexane), there's a moderate decrease of temperature (2% maximum) with rising hexane pressure. It falls down much faster when the reactor starts to operate in a condensed-mode reaching the 8% variation for each 0.1bar hexane increasing step

    The contribution of small shrubby patches to the functional diversity of wood-pastures

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    Wood-pastures are grazed systems resulting from a long-term use of natural woodlands by humans. These social-ecological systems, covering vast areas of Europe and other temperate regions, have both high biodiversity and economic values, so many are classified as High Nature Value Farmlands. However, in some regions a loss of spatial heterogeneity threatens this natural value. We investigated the potential contribution of tiny shrubby patches to increase spatial heterogeneity and functional diversity in wood-pasture landscapes. Specifically, we compared functional composition (Community Weighted Means) and functional diversity (Functional Dispersion and Functional Evenness) of assemblages of plants, beetles and lichens in those patches (252-3000 m(2)) and in the wood-pasture matrix. We found that shrubby patches and matrix harbour species assemblages with very distinct functional compositions in all studied taxonomic groups. Evergreen, woody, broad-leafed and fleshy-fruited are better represented in the patches. In beetles, the main differences were a greater prevalence of small-sized and fungivore species in the patches. Shrubby patches also mostly harboured lichens with fruticose- and foliose-broad growth forms, a greater humidity preference, and lower eutrophication tolerance. Moreover, the two indexes used to quantify functional diversity (Functional Dispersion and Functional Evenness) show that, overall, diversity is greater in patches than in the matrix; in patches Functional Dispersion is statistically higher for plants, and Evenness is statistically higher for beetles and lichen. These differences are all consistent with the very distinct ecological conditions in the matrix and patches. The greater overall functional diversity of shrubby patches, and the major differences in functional composition between patches and matrix, observed for all taxa, indicate that these patches greatly enhance the functional diversity of species assemblages in wood-pasture landscapes. Consequently, preserving and promoting tiny shrubby patches is a potentially valuable low-cost management tool to increase biodiversity and improve ecosystem functioning in wood-pasture landscapes.Peer reviewe

    Magnetic/plasmonic liposomes as nanocarriers for novel antitumor tricyclic lactones against non-small cell lung cancer

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    In this work, MnFe2O4/Au core/shell nanoparticles (NPs) and MnFe2O4 NPs decorated with Au NPs were synthesized and the structural, spectroscopic and magnetic properties evaluated. The prepared NPs were covered with a lipid bilayer, forming solid magnetoliposomes (SMLs). The heating capabilities of the nanosystems were assessed through the fluorescence quenching of Nile Red (incorporated in the lipid bilayer of the SMLs) under irradiation.UIDB/04650/2020; PTDC/QUI-QFI/28020/2017 (POCI-01-0145-FEDER-028020

    Assessing road effects on bats: the role of landscape, road features, and bat activity on road-kills

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    Recent studies suggest that roads can significantly impact bat populations. Though bats are one of the most threatened groups of European vertebrates, studies aiming to quantify bat mortality and determine the main factors driving it remain scarce. Between March 16 and October 31 of 2009, we surveyed road-killed bats daily along a 51-km-long transect that incorporates different types of roads in southern Portugal. We found 154 road-killed bats of 11 species. The two most common species in the study area, Pipistrellus kuhlii and P. pygmaeus, were also the most commonly identified road-kill, representing 72 % of the total specimens collected. About two-thirds of the total mortality occurred between mid July and late September, peaking in the second half of August. We also recorded casualties of threatened and rare species, including Miniopterus schreibersii, Rhinolophus ferrumequinum, R. hipposideros, Barbastella barbastellus, and Nyctalus leisleri. These species were found mostly in early autumn, corresponding to the mating and swarming periods. Landscape features were the most important variable subset for explaining bat casualties. Road stretches crossing or in the vicinity of high-quality habitats for bats—including dense Mediterranean woodland (‘‘montado’’) areas, water courses with riparian gallery, and water reservoirs—yielded a significantly higher number of casualties. Additionally, more roadkilled bats were recorded on high-traffic road stretches with viaducts, in areas of higher bat activity and near known roosts

    CDH1 promoter hypermethylation and E-cadherin protein expression in infiltrating breast cancer

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    BACKGROUND: The E-cadherin gene (CDH1) maps, at chromosome 16q22.1, a region often associated with loss of heterozygosity (LOH) in human breast cancer. LOH at this site is thought to lead to loss of function of this tumor suppressor gene and was correlated with decreased disease-free survival, poor prognosis, and metastasis. Differential CpG island methylation in the promoter region of the CDH1 gene might be an alternative way for the loss of expression and function of E-cadherin, leading to loss of tissue integrity, an essential step in tumor progression. METHODS: The aim of our study was to assess, by Methylation-Specific Polymerase Chain Reaction (MSP), the methylation pattern of the CDH1 gene and its possible correlation with the expression of E-cadherin and other standard immunohistochemical parameters (Her-2, ER, PgR, p53, and K-67) in a series of 79 primary breast cancers (71 infiltrating ductal, 5 infiltrating lobular, 1 metaplastic, 1 apocrine, and 1 papillary carcinoma). RESULTS: CDH1 hypermethylation was observed in 72% of the cases including 52/71 ductal, 4/5 lobular carcinomas and 1 apocrine carcinoma. Reduced levels of E-cadherin protein were observed in 85% of our samples. Although not statistically significant, the levels of E-cadherin expression tended to diminish with the CDH1 promoter region methylation. In the group of 71 ductal cancinomas, most of the cases of showing CDH1 hypermethylation also presented reduced levels of expression of ER and PgR proteins, and a possible association was observed between CDH1 methylation and ER expression (p = 0.0301, Fisher's exact test). However, this finding was not considered significant after Bonferroni correction of p-value. CONCLUSION: Our preliminary findings suggested that abnormal CDH1 methylation occurs in high frequencies in infiltrating breast cancers associated with a decrease in E-cadherin expression in a subgroup of cases characterized by loss of expression of other important genes to the mammary carcinogenesis process, probably due to the disruption of the mechanism of maintenance of DNA methylation in tumoral cells

    Factors influencing overall survival rates for patients with pineocytoma

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    Given its rarity, appropriate treatment for pineocytoma remains variable. As the literature primarily contains case reports or studies involving a small series of patients, prognostic factors following treatment of pineocytoma remain unclear. We therefore compiled a systematic review of the literature concerning post-treatment outcomes for pineocytoma to better determine factors associated with overall survival among patients with pineocytoma. We performed a comprehensive search of the published English language literature to identify studies containing outcome data for patients undergoing treatment for pineocytoma. Kaplan–Meier analysis was utilized to determine overall survival rates. Our systematic review identified 168 total patients reported in 64 articles. Among these patients, 21% underwent biopsy, 38% underwent subtotal resection, 42% underwent gross total resection, and 29% underwent radiation therapy, either as mono- or adjuvant therapy. The 1 and 5 year overall survival rates for patients receiving gross total resection versus subtotal resection plus radiotherapy were 91 versus 88%, and 84 versus 17%, respectively. When compared to subtotal resection alone, subtotal resection plus radiation therapy did not offer a significant improvement in overall survival. Gross total resection is the most appropriate treatment for pineocytoma. The potential benefit of conventional radiotherapy for the treatment of these lesions is unproven, and little evidence supports its use at present
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