Influence of nutrient enrichment on the growth, recruitment and trophic ecology of a highly invasive freshwater fish

The establishment probability of introduced alien fish can be context dependent, varying according to factors including propagule pressure and biotic resistance. The influence of nutrient enrichment on establishment outcomes of alien fishes is uncertain, yet this is a common anthropogenic stressor of many freshwaters. Here, the small-bodied alien topmouth gudgeon Pseudorasbora parva was used in mesocosms to experimentally test how a gradient of nutrient enrichment affected their growth rates, recruitment and trophic ecology. A ‘Control’ represented ambient, mesotrophic conditions, while treatments covered three levels of nutrient enrichment: Low (eutrophic), Medium (hypertrophic) and High (very hypertrophic). Each mesocosm was seeded with 6 mature P. parva (equal sex ratio) at the start of their reproductive season. After 100 days, length increments of the adult fish were significantly elevated in the Low treatment, and these fish had also produced significantly higher numbers of 0+ fish compared to all other treatments. The trophic niche width of the mature fish was substantially higher in the Control than the treatments, but this did not appear to confer any advantages to them in somatic growth rate or reproductive output. These results suggest that the nutrient status of receiving waters can have substantial impacts on the outcomes of fish introductions, where eutrophic conditions can assist the rapid population establishment of some alien species

Quantifying the AGN-driven outflows in ULIRGs (QUADROS) I: VLT/Xshooter observations of 9 nearby objects

Although now routinely incorporated into hydrodynamic simulations of galaxy evolution, the true importance of the feedback effect of the outflows driven by active galactic nuclei (AGNs) remains uncertain from an observational perspective. This is due to a lack of accurate information on the densities, radial scales and level of dust extinction of the outflow regions. Here we use the unique capabilities of VLT/Xshooter to investigate the warm outflows in a representative sample of nine local (0.06 < z < 0.15) Ultraluminous Infrared Galaxies (ULIRGs) with AGNs and, for the first time, accurately quantify the key outflow properties. We find that the outflows are compact (0.06 < R[O III] < 1.2 kpc), significantly reddened (median E(B − V) ∼ 0.5 magnitudes), and have relatively high electron densities (3.4 < log10 ne (cm−3) < 4.8). It is notable that the latter densities – obtained using trans-auroral [S II] and [O II] emission-line ratios – exceed those typically assumed for the warm, emission-line outflows in active galaxies, but are similar to those estimated for broad and narrow absorption line outflow systems detected in some type 1 AGN. Even if we make the most optimistic assumptions about the true (deprojected) outflow velocities, we find relatively modest mass outflow rates (0.07 < M < ˙ 14 M yr−1) and kinetic powers measured as a fraction of the AGN bolometric luminosities (4 × 10−4 < E/L ˙ BOL < 0.8 per cent). Therefore, although warm, AGN-driven outflows have the potential to strongly affect the star formation histories in the inner bulge regions (r ∼ 1 kpc) of nearby ULIRGs, we lack evidence that they have a significant impact on the evolution of these rapidly evolving systems on larger scales

Doença Pulmonar Obstrutiva Crónica em Portugal: estudo Pneumobil (1995) e estudo de prevalência de 2002 revisitados

ResumoIntroduçãoA doença pulmonar obstrutiva crónica (DPOC) tem sido, ao longo dos anos, uma importante causa de morbilidade e mortalidade no mundo. Em 1995, a implementação de um rastreio da função respiratória pareceu a forma mais adequada para alertar para os sintomas respiratórios negligenciados e sensibilizar para os rastreios espirométricos. Em 2002, foram criadas novas normas consensuais de diagnóstico e o reconhecimento de que a prevalência da DPOC depende dos critérios de definição de obstrução das vias aéreas. O objetivo deste estudo foi revisitar estes 2 estudos e publicar alguns dos resultados e respetivas metodologias.MétodosDos 12 684 indivíduos que constavam da base de dados do Pneumobil, apenas os indivíduos com 40 e mais anos (n = 9061) foram considerados para esta análise. No estudo de 2002 foi incluída uma amostra aleatorizada e representativa de 1384 indivíduos, com idades entre os 35 e os 69 anos.ResultadosA prevalência da DPOC foi de 8,96% no estudo Pneumobil e de 5,34% no estudo de 2002. Em ambos os estudos, a presença da DPOC foi superior no sexo masculino, tendo-se verificado uma associação positiva entre a presença da DPOC e os grupos etários mais velhos. Nos fumadores e ex-fumadores encontrou-se maior proporção de casos com DPOC.ConclusõesA prevalência em Portugal é mais baixa do que noutros países europeus, o que pode estar relacionado com uma menor prevalência de tabagismo. De um modo geral, os fatores de risco mais importantes que mostraram a associação com a DPOC foram a idade maior do que 60 anos, o sexo masculino e a exposição tabágica. Todos os aspetos e as limitações que se referem a diferentes critérios de definição e a metodologias de recrutamento realçam a necessidade de métodos padronizados para determinar a prevalência da DPOC e os fatores de risco associados, cujos resultados possam ser comparados entre países, como acontece no projeto BOLD.AbstractBackgroundChronic Obstructive Pulmonary Disease (COPD) has been a leading cause of morbidity and mortality worldwide, over the years. In 1995, the implementation of a respiratory function survey seemed to be an adequate way to draw attention to neglected respiratory symptoms and increase the awareness of spirometry surveys. By 2002 there were new consensual guidelines in place and the awareness that prevalence of COPD depended on the criteria used for airway obstruction definition. The purpose of this study is to revisit the two studies and to turn public some of the data and respective methodologies.MethodsFrom Pneumobil study database of 12,684 subjects, only the individuals with 40+ years old (n = 9.061) were selected. The 2002 study included a randomized representative sample of 1,384 individuals with 35-69 years old.ResultsThe prevalence of COPD was 8.96% in Pneumobil and 5.34% in the 2002 study. In both studies, presence of COPD was greater in males and there was a positive association between presence of COPD and older age groups. Smokers and ex-smokers showed a higher proportion of cases of COPD.ConclusionsPrevalence in Portugal is lower than in other European countries. This may be related to lower smokers’ prevalence. Globally, the most important risk factors associated with COPD were age over 60 years, male gender and smoking exposure. All aspects and limitations regarding different recruitment methodologies and different criteria for defining COPD cases highlight the need of a standardized method to evaluate COPD prevalence and associated risks factors, whose results can be compared across countries, as it is the case of BOLD project

Hippocampal Insulin Signaling And Neuroprotection Mediated By Physical Exercise In Alzheimeŕs Disease

Epidemiological studies indicate continuous increases in the prevalence of Alzheimer's Disease (AD) in the next few decades. The key feature of this disease is hippocampal neurodegeneration. This structure has an important role in learning and memory. Intense research efforts have sought to elucidate neuroprotective mechanisms responsible for hippocampal integrity. Insulin signaling seems to be a very promising pathway for the prevention and treatment of AD. This hormone has been described as a powerful activator of neuronal survival. Recent research showed that reduced insulin sensitivity leads to low-grade inflammation, and both phenomena are closely related to AD genesis. Concomitantly, exercise has been shown to exert anti-inflammatory effects and to promote improvement in insulin signaling in the hippocampus, which supports neuronal survival and constitutes an interesting non-pharmacological alternative for the prevention and treatment of AD. This review examines recent advances in understanding the molecular mechanisms involved in hippocampal neuroprotection mediated by exercise.2

Escapes of non-native fish from flooded aquaculture facilities: the case of Paranapanema River, southern Brazil

Non-native species are a major driver of biodiversity loss. Aquaculture activities play a key role in introductions, including the escape of fishes from fish farm facilities. Here, the impact of flooding due to El Niño rains in 2015/2016 in the Lower and Middle Paranapanema River basin, southern Brazil, was investigated by evaluating fish escapes from 12 fish farms. The flooding resulted in the escape of approximately 1.14 million fishes into the river, encompassing 21 species and three hybrids. Non-native species were the most abundant escapees, especially Oreochormis niloticus and Coptodon rendalli (96% of all fish). Only seven native fishes were in the escapee fauna, comprising 1% of all fish. Large floods, coupled with inadequate biosecurity, thus resulted in considerable inputs of non-native fish into this already invaded system

Entropy and equilibrium state of free market models

Many recent models of trade dynamics use the simple idea of wealth exchanges among economic agents in order to obtain a stable or equilibrium distribution of wealth among the agents. In particular, a plain analogy compares the wealth in a society with the energy in a physical system, and the trade between agents to the energy exchange between molecules during collisions. In physical systems, the energy exchange among molecules leads to a state of equipartition of the energy and to an equilibrium situation where the entropy is a maximum. On the other hand, in the majority of exchange models, the system converges to a very unequal condensed state, where one or a few agents concentrate all the wealth of the society while the wide majority of agents shares zero or almost zero fraction of the wealth. So, in those economic systems a minimum entropy state is attained. We propose here an analytical model where we investigate the effects of a particular class of economic exchanges that minimize the entropy. By solving the model we discuss the conditions that can drive the system to a state of minimum entropy, as well as the mechanisms to recover a kind of equipartition of wealth

Graph Creation, Visualisation and Transformation

We describe a tool to create, edit, visualise and compute with interaction nets - a form of graph rewriting systems. The editor, called GraphPaper, allows users to create and edit graphs and their transformation rules using an intuitive user interface. The editor uses the functionalities of the TULIP system, which gives us access to a wealth of visualisation algorithms. Interaction nets are not only a formalism for the specification of graphs, but also a rewrite-based computation model. We discuss graph rewriting strategies and a language to express them in order to perform strategic interaction net rewriting

The Electronic Smell of the Orchard Fruit

Assessing fruit maturity at the end of the season is a hard task for fruit growers. This task is either made by visual inspection – which is tedious and time consuming - or using destructive procedures for measuring biophysical properties of the fruits, such as the sugar content. An alternative to measure the ripeness of fruits is measuring the volatile organic compounds emitted by the fruits. An important compound produced by the fruits in this stage is ethylene (C2H4). The recent advances in electro chemical semiconductors have enabled the rapid growth of electronic noses technologies and applications. Nevertheless, the research reported where its characteristics and limitations are explored only addresses experiments in controlled and indoor settings.Therefore, many questions remain regarding the electronic noses applicability in outdoor environments. This work presents preliminary evidences that there are good chances that ethylene can be detected outdoors via an electronic nose placed within an orchard field. The results presented are measurements acquired in a Conference pear (Pyruscommunis) orchard in September 2017. The measurements where acquired on several points within the field, and the maximum ethylene detection shows an increase of 10% over 400 seconds. These results were contrasted with a theoretical study where gas dispersion patterns can be appreciated when subject to the wind speeds recorded in the field. The simulation results indicated a good correlation between the practical and the theoretical simulation results. To the best of our knowledge this work is the first to report results from measurements using electronic noses in a non-controlled environment, and detecting spatial-temporal variability of natural gas sources

Simulación de sistemas de riego hibridos FV-RED: aplicación a riego directo

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMEN: Este artículo presenta la metodología utilizada en una herramienta de simulación de la productividad de sistemas de riego híbridos fotovoltaico-red, así como su aplicación a un sistema de riego directo en Marrakech, Marruecos. Se trata de una finca de olivar intensivo, cuyas necesidades de riego son 8 horas diarias entre marzo y octubre. La aportación fotovoltaica en ese periodo es de 1456 kWh/kWp, mientras que la red eléctrica tiene que aportar 66 kWh/kWp. Entre los meses de noviembre y febrero toda la energía fotovoltaica es desaprovechada (550 kWh/kWp) puesto que no se riega. Con el objetivo de generalizar el estudio, se analiza la influencia de las necesidades de riego diarias en la aportación FV mediante cuatro simulaciones adicionales para necesidades de riego diarias de 4 h, 10 h, 12 h y 16 h. Por ejemplo, en el mes de junio, y considerando 4 h de riego al día, la aportación FV es 104 kWh/kWp (cuando para las 8 h es 185 kWh/kWp), llegando a 239 kWh/kWp a partir de las 12 h de riego al día.ABSTRACT: This article explains the methodology used in a hybrid photovoltaic-grid irrigation system simulation tool, as well its application to a direct pumping system in Marrakech, Morocco. It is an intensive olive tree cultivation, with a daily irrigation need of 8 hours between March and October. The photovoltaic energy used in this period is 1456 kWh/kWp, while the grid electricity consumption is 66 kWh/kWp. Between November and February, the photovoltaic energy is wasted (550 kWh/kWp). To evaluate the influence of the irrigation needs in terms of the number of irrigation hours per day, four additional simulations were performed – for 4 h, 10 h, 12 h, and 16 h. For example, in June, and considering 4 h of irrigation per day, the photovoltaic energy used is 104 kWh/kWp (while it is 185 kWh/kWp for 8 hours), achieving 239 kWh/kWp from 12 hours of irrigation per day.info:eu-repo/semantics/publishedVersio