University of Extremadura

About: University of Extremadura is a education organization based out in Badajoz, Spain. It is known for research contribution in the topics: Population & Hyperspectral imaging. The organization has 7856 authors who have published 18299 publications receiving 396126 citations. The organization is also known as: Universidad de Extremadura.

Diversity, loss, and gain of malaria parasites in a globally invasive bird

Abstract: Invasive species can displace natives, and thus identifying the traits that make aliens successful is crucial for predicting and preventing biodiversity loss. Pathogens may play an important role in the invasive process, facilitating colonization of their hosts in new continents and islands. According to the Novel Weapon Hypothesis, colonizers may out-compete local native species by bringing with them novel pathogens to which native species are not adapted. In contrast, the Enemy Release Hypothesis suggests that flourishing colonizers are successful because they have left their pathogens behind. To assess the role of avian malaria and related haemosporidian parasites in the global spread of a common invasive bird, we examined the prevalence and genetic diversity of haemosporidian parasites (order Haemosporida, genera Plasmodium and Haemoproteus) infecting house sparrows (Passer domesticus). We sampled house sparrows (N = 1820) from 58 locations on 6 continents. All the samples were tested using PCR-based methods; blood films from the PCR-positive birds were examined microscopically to identify parasite species. The results show that haemosporidian parasites in the house sparrows’ native range are replaced by species from local host-generalist parasite fauna in the alien environments of North and South America. Furthermore, sparrows in colonized regions displayed a lower diversity and prevalence of parasite infections. Because the house sparrow lost its native parasites when colonizing the American continents, the release from these natural enemies may have facilitated its invasion in the last two centuries. Our findings therefore reject the Novel Weapon Hypothesis and are concordant with the Enemy Release Hypothesis.

Cytochrome P450 gene polymorphism and cancer.

Abstract: Human cytochrome P450 (CYP) enzymes play a key role in the metabolism of drugs and environmental chemicals. Several CYP enzymes metabolically activate procarcinogens to genotoxic intermediates. Phenotyping analyses revealed an association between CYP enzyme activity and the risk to develop several forms of cancer. Research carried out in the last decade demonstrated that several CYP enzymes are polymorphic due to single nucleotide polymorphisms, gene duplications and deletions. As genotyping procedures became available for most human CYP, an impressive number of association studies on CYP polymorphisms and cancer risk were conducted. Here we review the findings obtained in these studies regarding CYP1A1, CYP1A2, CYP1B1, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C18, CYP2C19, CYP2D6, CYP2E1, CYP3A4, CYP3A5, CYP3A7, CYP8A1 and CYP21 gene polymorphisms. Consistent evidences for association between CYP polymorphisms and lung, head and neck, and liver cancer were reported. Controversial findings suggest that colorectal and prostate cancers may be associated to CYP polymorphisms, whereas no evidences for a relevant association with breast or bladder cancers were reported. We summarize the available information related to the association of CYP polymorphisms with leukaemia, lymphomas and diverse types of cancer that were investigated only for some CYP genes, including brain, esophagus, stomach, pancreas, pituitary, cervical epithelium, melanoma, ovarian, kidney, anal and vulvar cancers. This review discusses on causes of heterogeneity in the proposed associations, controversial findings on cancer risk, and identifies topics that require further investigation. In addition, some recommendations on study design, in order to obtain more conclusive findings in further studies, are provided.

Current trends in economy, sustainable development, and energy: a circular economy view

Abstract: Nowadays, it is widely recognized that the current production and consumption models are no longer adequate because of the inefficient use of resources (especially energy) and its dramatical consequences, environmental load and social inequality (UNEP 2011). In this context, Circular Economy (CE) has started to be considered a sustainable economic paradigm (Geissdoerfer et al. 2017), enabled by novel business models (Lewandowski 2016) and responsible consumers (Borrello et al. 2017). As highlighted by McDowall et al. 2017), the origin of the concept emerged in Europe in the 1980s and 1990s, together with early policies of the EuropeanUnionmember states, drawing on ideas that can be traced to the 1970s. Driven by a desire to divert waste from landfill, the Netherlands and Germany pioneered concepts of waste prevention and reduction, with the waste hierarchy introduced to the Dutch Parliament in 1979. However, even acknowledging that CE was rooted in environmental economics, there is today a huge interdisciplinary framework underpinning CE. This new framework offers good prospect for gradual involvement of the present economic system, including production and consumption models. We can say that at the moment, CE has the supreme goal of promoting sustainable development through the dissociation of environmental pressure from economic growth (Ghisellini et al. 2016; Schandl et al. 2016; Bruel et al. 2019). According to Ghisellini et al. (2016), CE is a new economic system aiming to increase the efficiency of resource use to achieve improvements in the existing balance between economy, environment and society. In this line, the concept of CE has recently been proposed as a new development strategy that aims to mitigate the contradiction between the rapid economic growth and the shortage of raw materials and energy (Christis et al. 2019). Although there is no commonly accepted definition of CE so far, the core of CE is the closed flow of materials and the use of raw materials and energy through multiple phases (Gan et al. 2013). The ‘3R’ principles—reduction, reuse, and recycling of materials and energy—are often cited to describe the three possible approaches in practice (the goals of reduce, reuse, and especially recycle have become the only acceptable ways of disposing of waste (Yong 2007, Yellishetty et al. 2011, Samiha 2013, Ahmadi 2017, Huang et al. 2018). This concept has been pursued by many countries’ environmental policy makers as a potential strategy to solve existing environmental problems (Preston and Carr 2018). As one of the main objectives of governments is to promote the sustainable development of economy and society, it also helps to achieve sustainable environmental protection (Yuan et al. 2006). Once the high economic potential of CE has been recognized, in the European Union, different CE Action Plans have been proposed as new initiatives, changes or adaptations to legislation, mainly related to waste and landfills at the beginning. In 2015, a range of policy measures collectively known as the Circular Economy Package, and later replaced by the Closing the Loop-An Action Plan for the CE, were approved in Europe (COM2015). At present times the CE is a priority for Europe. Nearly 1 billion from Horizon 2020’s final Work Responsible editor: Philippe Garrigues