Caracterização do efetivo caprino da raça Boer em Portugal

A raça caprina Boer, originária da Africa do Sul, é considerada uma das raças mais importantes para a produção de carne, apresentando uma excelente capacidade de adaptação, sendo por isso explorada, com sucesso, em várias zonas do globo, com condições meteorológicas muito variadas. Atualmente, a exploração de caprinos desta raça em Portugal ainda tem uma expressão bastante diminuta, tendo sido concluída a criação do Livro Genealógico (LG) da raça Boer em novembro de 2015, gerido pela APCRB – Associação Portuguesa de Caprinicultores da Raça Boer. Pretendeu-se com este estudo contribuir para a caracterização do efetivo caprino Boer existente em Portugal. O trabalho baseou-se nos dados obtidos em visitas realizadas às explorações, no processo de registo dos animais no LG da raça. Atualmente, em Portugal, existem nove criadores, mas apenas oito com animais inscritos no LG, com um efetivo total de 142 animais, 112 fêmeas e 30 machos. Os animais são nascidos em Portugal (48,6%), e importados, principalmente da Alemanha (36,6%), mas também da Holanda (12,7%) e Espanha (2,1%). As explorações encontram-se distribuídas pelos concelhos de Alandroal, Benavente, Vidigueira, Campo-Maior, Coruche, Évora, Portalegre, Porto de Mós e Vila Nova de Foz Côa. Os criadores, na sua maioria, exploram os animais em sistema semi-intensivo, com base no pastoreio direto e suplementação, com feno e alimento composto comercial. Apenas um criador explora os animais em sistema extensivo. Regra geral, não existem épocas de cobrição definidas. Os machos são mantidos junto das fêmeas e a beneficiação realiza-se por cobrição natural. Excecionalmente, no ano de 2016, dois criadores recorreram à inseminação artificial, por laparoscopia, com sémen importado da Austrália. A dimensão dos efetivos por exploração é diversa, variando entre quatro e trinta animais, com um valor médio de dezoito animais. O efetivo nacional é relativamente jovem, predominando animais com idades entre um e três anos, representando 85% do efetivo. O número de nascimentos aumentou entre 2007 e 2013, ano em que se registou o valor mais elevado (42), tendo este vindo a decrescer posteriormente. A inexistência de épocas de cobrição definidas reflecte-se numa distribuição dos nascimentos ao longo de todo o ano. A pontuação obtida na classificação morfológica dos animais, efetuada até ao momento, permitiu que a sua totalidade fosse inscrita no LG. Apesar de uma expressão ainda diminuta do efetivo Boer em Portugal, a expansão desta raça afigura-se interessante, dadas as excelentes características destes animais para a produção de carne.info:eu-repo/semantics/publishedVersio

Contribution of primary producers to mercury trophic transfer in estuarine ecosystems: Possible effects of eutrophication

http://www.sciencedirect.com/science/article/B6V6N-4V2X6WR-2/2/583d9d39ab618163fcc19f359dde856

Infection characteristics of a trematode in an estuarine isopod: influence of substratum

The estuarine isopod Cyathura carinata is a second intermediate host to microphallid trematodes, which use mud snails Hydrobia spp. and shorebirds as respectively first intermediate and final hosts. To identify processes responsible for infection patterns observed in C. carinata, a short-term microcosm experiment was conducted with both macroinvertebrates and one of their common parasites – Maritrema subdolum. Fine sand collected from two different shallow water sites was used to test if sediment type could affect infection rates. After 7 days at 25 °C, C. carinata from the substratum with the highest proportion of particles µm were more surface active and obtained significantly more M. subdolum individuals than isopods from the other sediment type. No parasite-induced effects on the hosts were found during this short-term experiment. The distribution pattern of microphallid cysts and mesocercariae inside the isopods revealed that M. subdolum cercariae primarily penetrated through the pleopods and afterwards located themselves in the middle-posterior region of the host’s body. Even if it was not possible to identify the factor responsible for the observed infection patterns (cercariae production and/or host behaviour), the results of this experiment indicate that small-scale factors, such as differences in substratum and associated features, may have considerable impact on infections of host populations

Estuarine production of resident and nursery fish species: Conditioning by drought events?

The production of resident (Pomatoschistus minutus and Pomatoschistus microps) and marine juvenile fish species using the Mondego estuary (central Portugal) as nursery grounds (Dicentrarchus labrax, Platichthys flesus, Solea solea), was assessed in order to: (1) understand the potential of the estuary for fish production; (2) know the production of nursery fish species likely to be exported to the coastal stocks; and (3) how anthropogenic and natural stress could influence the estimated production. Sampling occurred from June 2003 to May 2006 and together the 5 species in study comprised around 70% of the whole fish community numbers and biomass. Increasing drought conditions were observed, starting with a normal hydrological year in 2003 until attaining a severe drought in 2005, which resulted in low river discharges (1/3 of the mean river discharges in 2003). Additionally, high water temperatures were observed in 2003 and 2005 (24 and 26 °C, night temperatures). The secondary production was estimated using the increment summation method, after recognition of the cohorts. Production was in general lower in the Mondego estuary when compared to other systems, which was associated to the estuary's small area (only 3.4 km2, less than 1/4 of area compared to other studied systems). Dicentrarchus labrax was among the most productive species. Production decreased in the drought year for all species, especially evident for D. labrax, P. minutus and P. flesus. No direct effects could be attributable to the salinity and temperature variations and to the low freshwater discharges (resulting from the drought and high temperatures), yet these were pointed as probable major reasons for the decreased production. A significant reduction (15-45% reduction in the estuarine production) was also concluded for the potential production to be exported for coastal areas by the nursery species in the drought conditions.http://www.sciencedirect.com/science/article/B6WDV-4R9GGXS-2/1/663d5981f8928a75fea6999bf328f16

Impact of eutrophication on the life cycle, population dynamics and production of Ampithoe valida (Amphipoda) along an estuarine spatial gradient (Mondego estuary, Portugal)

The life cycle, population dynamics and production of Ampithoe valida was studied from an intertidal mudflat in central Portugal, close to the northern limit of the species¹ distributional range in the eastern Atlantic Ocean. Sampling was carried out in eutrophicated areas, where macroalgae blooms of Enteromorpha spp. occur usually from January to early summer, and also in non-eutrophicated areas, with Zostera noltii meadows. A. valida showed a contagious distribution and the population density clearly changed during the study period along the eutrophication gradient. No migratory patterns were detected between the estuary and the sea, but migrations inside the estuary might have occurred. Females were morphologically recognisable at smaller sizes than males. Females reached sexual maturity before males, but males may live slightly longer than females. Females are iteroparous, producing 2, perhaps 3, broods. A 2-generation life cycle involving a short-lived (7 mo), fast-growing summer generation and a longer-lived (9 mo), slower-growing generation that overwinters is hypothesised. Ovigerous females were present year-round. Eggs, depending on the season, increase differently in volume during marsupial development. No correlations were found between fecundity (number of eggs) and the size of females. Along the eutrophication gradient no differences were found regarding the biology of the species. Besides these features, differences were observed between eutrophicated and non-eutrophicated areas with regard to productivity. Growth production (P) of A. valida in the most eutrophicated area was 0.098 g m-2 18 mo-1 and 0.64 g m-2 18 mo-1 in the Z. noltii meadows. P/B- and E/B- ratios (where E is the elimination production and B- is the average population biomass) ranged from 1.42 and 3.06 in the most eutrophicated area to 5.98 and 12.41 in the Z. noltii beds. To a certain extent, the increase of macroalgae biomass may favour A. valida populations, but extensive blooms affecting the whole area of distribution of this species will determine its disappearanc

Modeling ultra-high frequency radiation emission in PIC codes

From the mysterious?ray bursts, which can be studied through the spatiotemporal structure of the radiation we receive, to the creation of sources of x-rays capable of probing nanoscale structures, radiation emission by relativistic charges is a key research field in plasma physics.The processes behind radiation emission in plasmas result from strongly non-linear many body interactions which involve relativistic effects, so they are best modeled through Particle-In-Cell (PIC) simulations. However, capturing this radiation directly in PIC simulations is very challenging due to the large disparity between the temporal and spatial scales associated with such phenomena. Current algorithms only describe radiation processes in the Fourier space (e.g.JRAD [1]), missing the spatiotemporal features of the emitted radiation, which is crucial to many fields, such as super-resolution microscopy [2] and astrophysics [3].info:eu-repo/semantics/publishedVersio

RaDiO: An efficient spatiotemporal radiation diagnostic for particle-in-cell codes

This work describes a novel radiation algorithm designed to capture the three-dimensional, space-time resolved electromagnetic field structure emitted by large ensembles of charged particles. The algorithm retains the full set of degrees of freedom that characterize electromagnetic waves by employing the Liénard-Wiechert fields to retrieve radiation emission. Emitted electric and magnetic fields are deposited in a virtual detector using a temporal interpolation scheme. This feature is essential to accurately predict field amplitudes and preserve the continuous character of radiation emission, even though particle dynamics is known only in a discrete set of temporal steps. Our algorithm retains and accurately captures, by design, full spatial and temporal coherence effects. We demonstrate that our numerical approach recovers well known theoretical radiated spectra in standard scenarios of radiation emission. We show that the algorithm is computationally efficient by computing the full spatiotemporal radiation features of High Harmonic Generation through a plasma mirror in a Particle-In-Cell (PIC) simulation.info:eu-repo/semantics/publishedVersio

Phosphorus speciation and availability in intertidal sediments of a temperate estuary: relation to eutrophication and annual P-fluxes

For a better understanding of the phosphorus dynamics and bioavailability in temperate climates, sequential chemical extraction techniques were used to study sediment P-pools distribution and relative importance in a eutrophicated estuary.http://www.sciencedirect.com/science/article/B6WDV-4D34K0B-4/1/81664d8a2942d81fa74d7a11d696e2b

Determination of seventeen endocrine disruptor compounds and their spatial and seasonal distribution in Ria Formosa Lagoon (Portugal)

In spite of its outstanding ecological and touristic importance the Ria Formosa Lagoon shows signs of anthropogenic pollution. Nonetheless, until the present survey no studies had ever documented the measurement of natural and pharmaceutical estrogens (17β-estradiol, estrone, and 17α-ethynylestradiol), xenoestrogenic industrial pollutants (4-octylphenol, 4- nonylphenol, and their mono and diethoxylates and bisphenol A), phytoestrogens (formononetin, biochanin A, daidzein, genistein), and sitosterol in this area. The 17 compounds measured herein are known as endocrine disrupters (EDCs) and act over the endocrine system even in few amounts (ng L−1–μg L−1). Thus to conclude about the influx of EDCs in the lagoon, water samples were taken every 2 months, during 1 year (2010), in low tide at nine sites distributed along the coastline. Water samples (1 L) were preconcentrated in the Oasis HLB cartridges and cleaned in silica cartridges before their analysis by GC-MS. Data showed the ubiquitous presence of potentially hazardous amounts of estrogens (particularly of ethynylestradiol, up to 24.3 ng L−1), nonylphenol (up to 547 ng L−1), and sitosterol (up to 12,300 ng L−1), mainly in summer, suggesting that the increase of the local number of inhabitants (tourists), the rise of the water temperature (up to 26 °C), and the blooming of local flora may interfere with the water quality parameters. This makes the lagoon a potential model to study. Taking into account the data, it was concluded that there are conditions for the occurrence of endocrine disruption in aquatic animals, even in areas included in the natural park of the Formosa. Besides, both the high amounts of un-ionized ammonia (up to 0.3 mg L−1) and phosphates (up to 1.6 mg L−1) my pose risks for local fauna and humans.This work was financially supported by FEDER funds through the Competitiveness and Trade Expansion Program—COMPETE and by National Funds provided by Fundação para a Ciência e a Tecnologia (FCT), via the project PTDC/MAR/70436/2006

PCB bioaccumulationin three mullet species — A comparison study

Polychlorinatedbiphenyls(PCBs)arelipophiliccontaminantsthattendtoaccumulateinorganisms.PCBs weredetectedin Chelon labrosus, Liza aurata and Liza ramada, alongdifferentagegroups. L. ramada presentedthehighestconcentration,anditincreasedwithage,whereas C. labrosus and L. aurata concentration remainedconstant. L. ramada high concentrationcanbeattributedtoitsecologicalniche, since thisspeciesisabletoaccumulatePCBsalongitsdifferentagegroupseveninlowenvironmental contamination conditions.PCBs101,118,138,149,153,170and180werethecongenersthatmore contributed tothesespeciescontamination,beingPCB138and153thecongenerswithhigher concentration. Mulletsareedibleinmanycountries,beingimportantin fisheries andaquaculture. L. ramada is themostcommonmulletforcaptureandhumanconsumption.Allspeciespresented concentrations belowtheregulationlimitestablishbytheEuropeanUnion,andthereforesafeforhuman consumption.The authorswishtothankallthecolleaguesthathelpedinthe field and laboratorywork.ThisworkwassupportedbyFCT(Fundaçãopara a CiênciaeTecnologia)throughaPhDgrantattributedtoJ.Baptista (SFRH/BD/48262/2008),fundedbyProgramaOperacionalPotencial HumanoofQRENPortugalandbythe Portuguesebudgetthroughthe Ministry ofScienceTechnologyandEducation.P.Patoacknowledgesa postdoctoralfellowshipfromFCT(SFRH/BPD/35068/2007)