Manual de produção de manteiga.

Processo de fabricação. Desnate natural, mecânico. Filtração do creme, tratamento do creme. Estocagem do creme. Padronização. Neutralização. Pasteurização. Resfriamento. Maturação natural, artificial. Batedura. Lavagem da manteiga. Salga da manteiga. Malaxagem.bitstream/item/118248/1/manual-de-producao-de-manteiga.pd

Stochastic group selection model for the evolution of altruism

We study numerically and analytically a stochastic group selection model in which a population of asexually reproducing individuals, each of which can be either altruist or non-altruist, is subdivided into $M$ reproductively isolated groups (demes) of size $N$. The cost associated with being altruistic is modelled by assigning the fitness $1- \tau$, with $\tau \in [0,1]$, to the altruists and the fitness 1 to the non-altruists. In the case that the altruistic disadvantage $\tau$ is not too large, we show that the finite $M$ fluctuations are small and practically do not alter the deterministic results obtained for $M \to \infty$. However, for large $\tau$ these fluctuations greatly increase the instability of the altruistic demes to mutations. These results may be relevant to the dynamics of parasite-host systems and, in particular, to explain the importance of mutation in the evolution of parasite virulence.Comment: 12 pages, 7 figure

Electrical methods of determining soil moisture content

The electrical permittivity of soils is a useful indicator of soil moisture content. Two methods of determining the permittivity profile in soils are examined. A method due to Becher is found to be inapplicable to this situation. A method of Slichter, however, appears to be feasible. The results of Slichter's method are extended to the proposal of an instrument design that could measure available soil moisture profile (percent available soil moisture as a function of depth) from a surface measurement to an expected resolution of 10 to 20 cm

Shelf-Ocean material exchange influencing the Atlantic chemical composition off NW Iberian margin since the last glaciation

Rivers are the main conduit of sediment to the shelf. The basin geology, the drainage area and the discharge rate are the major factors that determine their sediment load (Milliman and Syvistski, 1992). Besides suspended particles, dissolved components may also give some information on the eroded crust. Sr isotopes in carbonate shells of biological organisms have been used to study, in the geological record, the influence exerted by the chemical weathering of the continental crust on the seawater composition (Macdougall, 1991). In this work, Sr isotope ratios obtained in tests of foraminifera representing the last 40 ka are presented and discussed in the scope of the palaeogeographical evolution of NW Iberia. This work aims to present and discuss the results of Sr isotope analyses (performed, by TIMS, in the Isotope Geology Laboratory of the University of Aveiro) of tests of two species of foraminifera, from nine samples taken along the OMEX core KC 024-19 (181 cm; 42°08’98’’N, 10°29´96’’W, and 2765m), collected in the Galicia Bank area, off Galicia. Taking into account that Sr contained in the carbonate tests is usually considered as preserving the signature of the contemporaneous seawater, one planktonic species (Globigerina bulloides) and one benthic species (Cibicides wuellerstorfi) were selected in order to try to detect Sr isotope variations both through time and between two different levels of the water column. The core age model, which records the last 40 ka, is based on a combination of oxygen isotope stratigraphy, eight AMS 14C datings and the synchronisation of the last four Heinrich Events in the Iberian Margin sedimentary records. As a whole, the obtained 87Sr/86Sr ratios vary between 0.709209 and 0.709108, with a mean 2σ error of 0.000025. These values lie within the range of modern marine Sr isotope ratios (0.70910-0.70922), as previously defined using analyses of both seawater and marine carbonates (see compilation by Faure and Mensing, 2005). Despite their small variation, the 87Sr/86Sr ratios obtained in G. bulloides seem to indicate that Sr dissolved in seawater at the KC 024-19 core site became slightly less radiogenic after the Last Glacial Maximum (LGM). This decrease is concomitant with diminishing amounts of the detrital components in the sediments (Fig. 1). Therefore, both the composition of dissolved Sr, as revealed by results on tests of planktonic foraminifera, and the proportions of suspended terrigenous particulate material arriving at the KC 024-19 site point to a decreasing importance of the contribution of the erosion of the Iberian Variscan crust since the Last Glacial Maximum and in the Holocene. The 87Sr/86Sr ratios measured in tests of benthic foraminifera (C. wuellerstorfi) are more erratic and no correlation can be established with palaeogeographical/palaeoclimatic constraints. The difference between the behaviour of Sr compositions in G. bulloides and C. wuellerstorfi may indicate that whilst the planktonic foraminifera should reproduce very closely the seawater composition, the benthic organisms should, in addition to the major role of seawater, also be affected by some sort of interaction with the sediments. As such, planktonic foraminifera are probably more reliable indicators of seawater composition in studies involving very small periods and corresponding very slight variations of the 87Sr/86Sr ratios. Taking into account that G. bulloides is a common planktonic species (living mostly in the first 50m of the water column), whose tests seem to be in equilibrium with sea water composition, variations in its 87Sr/86Sr ratios can be related with changes in the chemical composition of the water of the Atlantic Ocean off NW Iberian Margin. The highest 87Sr/86Sr values are contemporaneous with a period of low sea level (about -140 m; Dias et al., 2000) during the LGM. According to Dias et al. (2000) at 18 ka BP the shoreline was close to the shelf break. The summital parts of the Gerês and Estrela mountains were covered by local glaciers and close to the coast freezing occurred frequently. The river catchments, which extended far to the shelf, received more rainfall due to a longer, compared to present day conditions, wet season, which promoted both physical and chemical weathering. Higher pluviosity combined with the effect of spring ice melting maintained high river discharge and consequently caused very important sediment supply to the coastal zone. The extremely narrow shelf was a very energetic environment due to sea bottom inclination and very limited long wave refraction. Therefore, at that time, a long wet season and very competent rivers should have caused important erosion of the Variscan basement in NW Iberia. Additionally, then, the shoreline was much closer to the KC 024-19 site. The combination of all these factors favoured an important deposition of terrigenous sediments and the local slight enrichment in radiogenic Sr of the seawater. With sea level rise, after the deglaciation and during the Holocene, the river estuaries became progressively far away from the shelf break. Their competence of transport also became progressively reduced and the offshore transport of detrital sediments became progressively lower. Conversely the biogenic carbonate proportion in the sediments increased, due to lower dilution by the terrigenous particles. Simultaneously, the values of 87Sr/86Sr in the seawater at the KC 024-19 site became lower, as a consequence of a complete homogenization with the ocean global composition, which was now more effective with the increasing distance towards shoreline

Recomendações técnicas para o processamento de hortaliças congeladas.

Fluxograma de processamento. Descrição das etapas de produção: recepção da matéria-prima e lavagem; descascamento; seleção e corte; branqueamento; resfriamento; embalagem; congelamento; armazenamento.bitstream/item/34377/1/2000-DOC-0040.pd

Probing ferroelectricity in highly conducting materials through their elastic response: persistence of ferroelectricity in metallic BaTiO3-d

The question whether ferroelectricity (FE) may coexist with a metallic or highly conducting state, or rather it must be suppressed by the screening from the free charges, is the focus of a rapidly increasing number of theoretical studies and is finally receiving positive experimental responses. The issue is closely related to the thermoelectric and multiferroic (also magnetic) applications of FE materials, where the electrical conductivity is required or spurious. In these circumstances, the traditional methods for probing ferroelectricity are hampered or made totally ineffective by the free charges, which screen the polar response to an external electric field. This fact may explain why more than 40 years passed between the first proposals of FE metals and the present experimental and theoretical activity. The measurement of the elastic moduli, Young's modulus in the present case, versus temperature is an effective method for studying the influence of doping on a FE transition because the elastic properties are unaffected by electrical conductivity. In this manner, it is shown that the FE transitions of BaTiO3-d are not suppressed by electron doping through O vacancies; only the onset temperatures are depressed, but the magnitudes of the softenings, and hence of the piezoelectric activity, are initially even increased

Temporal and spatial distributions of delphinid species in Massachusetts Bay (USA) using passive acoustics from ocean gliders

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Silva, T. L., Mooney, T. A., Sayigh, L. S., & Baumgartner, M. F. Temporal and spatial distributions of delphinid species in Massachusetts Bay (USA) using passive acoustics from ocean gliders. Marine Ecology Progress Series, 631, (2019): 1-17, doi:10.3354/meps13180.Knowledge about marine mammal habitat use is necessary for informing ecosystem-based management and mitigating human impacts. Massachusetts Bay is an important marine mammal foraging area in the Gulf of Maine and an area of substantial human activity, but delphinid habitat use is poorly understood. The goals of this work were to (1) document temporal and spatial occurrence of delphinid species in Massachusetts Bay using passive acoustic monitoring from ocean gliders and (2) explore the potential influences of environmental conditions on delphinid distributions. Gliders were deployed in late fall and early winter of 2014 and 2015-2016 and were equipped with a digital acoustic recorder and conductivity-temperature-depth instrument. Gliders surveyed an area of approximately 1000 km2. Delphinid whistles were detected on 93 of 128 (73%) deployment days. Animals were detected more often at night. Presence was consistent over 2 years, although detection rates showed annual and monthly variability. Spatial distribution differed between years, but most detections occurred close to Stellwagen Bank. Visual assessment of spectrograms suggests the presence of 2 species, Atlantic white-sided dolphins and common dolphins. The reoccurrence of 2 probable signature whistles over several weeks and consecutive winter seasons suggests prolonged occupancy during winter and possible annual site fidelity. These data show a consistent and frequent presence of delphinids near a known marine mammal foraging area (Stellwagen Bank) during late fall and winter and are a first step towards understanding both how odontocetes influence the Massachusetts Bay/Gulf of Maine ecosystem and how they may be impacted by human activities.We gratefully acknowledge the NOAA Northeast Fisheries Science Center, Stellwagen Bank National Marine Sanctuary, The Nature Conservancy, Massachusetts Division of Marine Fisheries, and the University of Massachusetts Dartmouth for their collaboration and support for this project. We thank Susan Parks, Julie Oswald, Sofie Van Parijs, and Danielle Cholewiak for helpful discussionsand sharing acoustic recordings for species comparisons. We are grateful to Ben Hodges for critical assistance with preparing, deploying, and recovering gliders. Thanks to Michael Thompson for assistance with spatial analysis and Dave Wiley for support and insights into the Stellwagen Bank ecosystem. The WHOI Marine Mammal Center provided additional funding for this work. Funding support for T.L.S. was provided by the NOAA Dr. Nancy Foster Scholarship. Finally, we thank the 3 anonymous re viewers for their comments and suggestions that improved this manuscript