787 research outputs found

    Managing aquaculture in multi-use freshwater bodies: the case of Jatiluhur reservoir

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    The pressure on scarce freshwater resources from intensifying human activity is rising across the globe. This study presents the case of Jatiluhur—Indonesia\u27s largest reservoir, where unregulated aquaculture expansion has contributed to environmental degradation and associated conflicts with other water-users. Aiming to identify a strategy to improve the sustainability of cage aquaculture within Jatiluhur reservoir and other freshwater bodies facing similar challenges, this study consisted of an initial analysis of time bound satellite images of the reservoir and a systematic survey of 112 aquaculture farms. The results revealed that, with more than 45 000 production units in 2020, more than half of which are placed outside government-approved aquaculture zones, the carrying capacity of the reservoir is exceeded. An analysis of the farm-level production practices, pertinent to environmental regulation, indicated the existence of three main production strategies, with significant differences in eutrophication potential among them that would lead to better articulated policy actions. A feed manufacturer-focused policy to reduce total phosphorus levels in formulated diets by more than half, but still within the optimal level for fish performance, would have the most impact. Enforcement of registration and removal of illegal production units supported by satellite-based monitoring of compliance are key recommendations to support intensive cage culture remaining an important economic activity

    Isotopic evidence of a wide spectrum of feeding strategies in Southern hemisphere humpback whale baleen records

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    Our current understanding of Southern hemisphere humpback whale (Megaptera novaeangliae) ecology assumes high-fidelity feeding on Antarctic krill in Antarctic waters during summer, followed by fasting during their annual migration to and from equatorial breeding grounds. An increase in the number of reported departures from this feeding/fasting model suggests that the current model may be oversimplified or, alternatively, undergoing contemporary change. Information about the feeding and fasting cycles of the two Australian breeding populations of humpback whales were obtained through stable isotope analysis of baleen plates from stranded adult individuals. Comparison of isotope profiles showed that individuals from the West Australian breeding population strongly adhered to the classical feeding model. By contrast, East Australian population individuals demonstrated greater heterogeneity in their feeding. On a spectrum from exclusive Antarctic feeding to exclusive feeding in temperate waters, three different strategies were assigned and discussed: classical feeders, supplemental feeders, and temperate zone feeders. Diversity in the interannual feeding strategies of humpback whales demonstrates the feeding plasticity of the species, but could also be indicative of changing dynamics within the Antarctic sea-ice ecosystem. This study presents the first investigation of trophodynamics in Southern hemisphere humpback whales derived from baleen plates, and further provides the first estimates of baleen plate elongation rates in the species

    A criterion for separating process calculi

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    We introduce a new criterion, replacement freeness, to discern the relative expressiveness of process calculi. Intuitively, a calculus is strongly replacement free if replacing, within an enclosing context, a process that cannot perform any visible action by an arbitrary process never inhibits the capability of the resulting process to perform a visible action. We prove that there exists no compositional and interaction sensitive encoding of a not strongly replacement free calculus into any strongly replacement free one. We then define a weaker version of replacement freeness, by only considering replacement of closed processes, and prove that, if we additionally require the encoding to preserve name independence, it is not even possible to encode a non replacement free calculus into a weakly replacement free one. As a consequence of our encodability results, we get that many calculi equipped with priority are not replacement free and hence are not encodable into mainstream calculi like CCS and pi-calculus, that instead are strongly replacement free. We also prove that variants of pi-calculus with match among names, pattern matching or polyadic synchronization are only weakly replacement free, hence they are separated both from process calculi with priority and from mainstream calculi.Comment: In Proceedings EXPRESS'10, arXiv:1011.601

    Experimental evidence of parametric decay processes in the variable specific impulse magnetoplasma rocket (VASIMR) helicon plasma source

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    Decay waves have been observed in the megahertz range in the helium plasma generated by the variable specific impulse magnetoplasma rocket magnetoplasma thruster. They are measured using one of the tips of a triple probe connected to a 50 Ω input of a spectrum analyzer via a dc block (a small capacitor). The maximum amplitude of all waves is in the center of the plasma and does not appear correlated to the radial electron density or temperature profiles. The waves seem to be generated close to the helicon antenna that was 91 cm “upstream” from the measuring Langmuir probe. A possible explanation is parametric decay of the large amplitude helicon wave that also generates the plasma.This project was proudly supported by the International Science Linkages programme established under the Australian Government’s innovation statement Backing Australia’s Ability

    Protective effects of antiâ C5a peptide antibodies in experimental sepsis

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    We evaluated antibodies to different peptide regions of rat C5a in the sepsis model of cecal ligation and puncture (CLP) for their protective effects in rats. Rabbit polyclonal antibodies were developed to the following peptide regions of rat C5a: aminoâ terminal region (A), residues 1â 16; middle region (M), residues 17â 36; and the carboxylâ terminal region (C), residues 58â 77. With rat neutrophils, the chemotactic activity of rat C5a was significantly inhibited by antibodies with the following rank order: antiâ C > antiâ M â « antiâ A. In vivo, antibodies to the M and C (but not A) regions of C5a were protective in experimental sepsis, as determined by survival over a 10â day period, in a doseâ dependent manner. The relative protective efficacies of antiâ C5a preparations (in descending order of efficacy) were antiâ C â ¥ antiâ M â « antiâ A. In CLP rats, a delay in infusion of antibodies, which were injected at 6 or 12 h after CLP, still resulted in significant improvement in survival rates. These in vivo and in vitro data suggest that there are optimal targets on C5a for blockade during sepsis and that delayed infusion of antiâ C5a antibody until after onset of clinical evidence of sepsis still provides protective effects.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154417/1/fsb2fj000653fje-sup-0001.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154417/2/fsb2fj000653fje.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154417/3/fsb2fj000653fje-sup-0002.pd

    Ageing and Long-Term Care Planning Perceptions of Hispanics in the USA: Evidence from a Case Study in New London, Connecticut

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    This paper explores the ageing attitudes and long-term care planning behavior of adult Hispanics in New London, Connecticut, a town with 30 thousand inhabitants that is rapidly ageing. We conducted six focus groups and had 37 participants share their ageing perceptions and long-term care needs. Our main findings suggest that informal care arrangements are vulnerable and unsustainable especially since women have historically and disproportionately provided most family eldercare even at their own personal and financial expense. Though male participants expected their female relatives to care for them when they age and need personal assistance, female participants did not necessarily expect the same from their relatives including their daughters. Also, both formal and government long-term care systems lack cultural competence and can be prohibitively costly. Therefore, Hispanics plan for ageing within their circles of family care and their resilience in a context of cultural exclusion and socio-economic disadvantage epitomizes strong intergenerational values. These support networks may help explain why may outlive whites (the Hispanic paradox ) who, on average, have higher wealth and education levels. Long-term care planning is a complex process that cannot be relayed to families only. Adequate training for family members from other relatives, and from private and government entities to appropriately convey this type of planning is vital to ensure that Hispanic families understand their options
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