783 research outputs found

    Do national resources have to be centrally managed? Vested interests and institutional reform in Norwegian fisheries governance

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    Corporatism -with its privileged access, restricted participation and centralized structures - has a long history in Norwegian fisheries governance. Co-management – understood as a decentralized, bottom-up and more inclusive form of fisheries governance - has not been considered a relevant alternative.. Why does corporatism still prevail in a context where stakeholder status in fisheries governance globally – both in principle and practice - has been awarded environmental organizations, municipal authorities and even consumer advocacy groups? Why then have alternatives to the corporatist system of centralized consultation and state governance never been seriously considered in Norway, in spite of the growing emphasis on fish as a public resource and fisheries management as human intervention in geographically confined and complex ecosystems? We suggest that thismay have to do with the fundamental assumptions behind Norwegian fisheries governance that since fish is a national resource, it must be centrally managed. We argue that this is an assumption that may be contested

    Towards the pressure and material gap in heterogeneous catalysis: hydrogenation of acrolein over silver catalysts

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    Introduction In recent time, increasing effort has been undertaken in order to answer the question, whether it is justified to transfer results from surface science studies, mostly obtained with idealised surfaces under UHV conditions, to "real" catalysis, i.e. high pressures and complex materials (the so-called pressure and material gaps). The DFG (German research foundation) has initialised a priority program (SPP 1091) in order to bring together experts from surface science, materials science, catalysis and theory with the aim of bridging the two gaps in catalysis. Within this priority program, we are currently studying the hydrogenation of acrolein over silver. Acrolein, an ,-unsaturated aldehyde, can be hydrogenated either to propanal (product of C=C-bond hydrogenation) or to allyl alcohol (product of C=O-bond hydrogenation. Whereas typical hydrogenation catalysts like Pt, Ru or Ni mainly produce the saturated aldehyde, selectivities to allyl alcohol of up to 53 % can be obtained when using monometallic silver (or gold) catalysts [ , ]. The aim of our studies is to clarify the influence of reaction pressure and material on the selectivity distribution in the acrolein hydrogenation. Catalytic experiments have been carried out with differently structured samples from single crystals to disperse Ag/support catalysts in a broad pressure range (few mbar up to 20 bar). Various methods like in situ-XAS and XPS, flow-adsorption calorimetry, infrared spectroscopy, and transient analysis of products (TAP) are performed in order to gain insight into the modes of interaction of acrolein and hydrogen with differently structured silver samples. Effects of particle size and shape are also considered as well as the influence of the support material. Experimental and Results would add a few words about the composition (Ag loading, different supports) / preparation of the catalysts and/or a reference Gas phase hydrogenation of acrolein has been carried out in a flow reaction system allowing a pressure in the range from 150 mbar up to 20 bar. When using silica supported silver catalysts, clear relations can be drawn concerning the pressure and material dependence of the selectivity to allyl alcohol: increasing partial pressure of either reactant (hydrogen or acrolein) leads to increased selectivity to allyl alcohol, also, smaller particles favour its formation. However, when using ZnO-supported catalysts, the situation becomes more complex. Catalysts prepared with the same catalyst loading and the same catalyst preparation technique but with different ZnO support materials yielded different selectivities to allyl alcohol at the same conversion. On the other hand, catalysts prepared from different precursors, but with the same support, lead to different activities but similar selectivities to allyl alcohol. TEM investigations of the Ag/ZnO and Ag/SiO2 catalysts reveal, that the particle sizes of the silica-supported catalysts are much smaller (2 nm and 15 nm in average for the two most intensively studied catalysts) whereas the silver particles in the Ag/ZnO catalysts are surprisingly large (50 nm up to several hundreds of nm). This is even more surprising since the activities of the catalysts are in the same order of magnitude, with the SiO2 catalysts however, being a bit more active. All these results indicate, that the product distribution at supported silver catalysts is governed by a complex interplay between particle size (and/or shape), pressure, and, as the obviously most important factor, the support and the interactions between silver and support. To gain more insight into the reasons for the catalytic behaviour of the Ag/support catalysts, the interaction of hydrogen alone with various silver samples has been studied. TAP (temporal analysis of products) indicates, that hydrogen interacts with nanodisperse Ag/SiO2 samples, but not with larger unsupported silver particles (several mm in size) like those from electrolyte silver. However, as monitored by transmission infrared spectroscopy, not only the Ag nanoparticles but also the SiO2 support interacts with hydrogen. SiO2 and Ag/SiO2 samples, after reduction and exposure to 100 mbar D2, show a reversible H-D-exchange, as monitored by the Si-O-H(D) bands. Time resolved IR spectra indicate, that this H-D-exchange is faster at silver-containing samples. From temperature-dependent measurements, activation energies for the H-D-exchange of ca. 28 kJ/mol for Ag/SiO2 and ca. 38 kJ/mol for SiO2 have been calculated. The interaction of acrolein with silver single crystals as well as with supported catalysts has been studied with in-situ-XAS and in-situ XPS. For both techniques the samples were contacted with mixtures of H2/acrolein in the mbar pressure range. Angular dependent XAS measurements on a Ag(111) single crystal indicated that acrolein is in the lying-down orientation. For all the samples measured the 1π* “C=O” transition is clearly increased compared to the 1π* “C=C”. Consequently, the surface concentration of C=O bonds relative to C=C bonds is higher, which is in line with concomitantly measured mass spectrometric data showing high selectivity towards C=C hydrogenation. In-situ XPS revealed that while silver foil is partly oxidic (~5%) the supported silver particles are completely reduced, as Ag is in the zero valence state. Data indicate also small amount of oxygen removal from the ZnO supported samples during the contact with hydrogen. The combination of different results suggests that metal-support interaction plays an important role in the reaction. The major difference in hydrogen activation between supported catalysts and pure silver/support provides us a hint that the so-called “adlineation sites” (the perimeter interface between silver and support) are the key sites in the mechanism

    Lack of growth enhancement by exogenous growth hormone treatment in yellow perch (Perca flavescens) in four separate experiments

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    Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Elsevier B. V. for personal use, not for redistribution. The definitive version was published in Aquaculture 250 (2005): 471-479, doi:10.1016/j.aquaculture.2005.03.019.The effect of exogenous growth hormone (GH) treatment on the growth of juvenile yellow perch (Perca flavescens) was investigated in four experiments. In the first two experiments, juvenile yellow perch were reared at either 13°C or 21°C, and injected weekly with bovine GH (bGH) at 0.1, 1.0 or 10.0 μg/g body weight for 84 days. No significant growth enhancement in GH-treated fish was measured in fish in either of the experiments. In the third experiment, juvenile yellow perch were treated with estradiol-17β (E2, 15 μg/g of diet), bGH (1.0 μg/g body weight) injected weekly or both hormones for 70 days at 21°C. E2 alone stimulated growth, but no further growth stimulation occurred in the E2 + bGH-treated fish. In addition, no growth enhancement was found in fish treated with bGH alone. We measured no difference in serum insulin-like growth factor-I (IGF-I) levels between the treatment groups at 12 and 24 h after the final injection of GH; however, a drop in IGF-I levels after 24 h was observed. In a fourth study, the effect of recombinant yellow perch GH (rypGH, 0.2 or 1.0 μg/g body weight) injected weekly was evaluated in yellow perch juveniles. The fish were reared for 42 days at 18°C. Neither GH dosages improved growth compared to control-injected and non-injected fish. Taken together, the lack of effect of mammalian GH or rypGH in our experiments suggests (1) low binding affinity between these hormones and the GH receptor in yellow perch, (2) that the endogenous GH levels were already at biologically maximal levels or (3) that other endocrine factors are needed in order for GH to promote yellow perch growth. The reduction in IGF-I levels 24 h after handling suggests a negative effect of handling stress on the GH-IGF-I axis in yellow perch.This work was supported by the University of Wisconsin-Madison College of Agricultural and Life Sciences and School of Natural Resources; the Wisconsin Department of Natural Resources; the University of Wisconsin Sea Grant College Program, National Oceanic and Atmospheric Administration, US Department of Commerce; the State of Wisconsin (Federal Grant NA46RG0481, Project No. R/AQ-38); and the USDA NOAA Project R/A-05-99, grant #NA86RG0048 to FG and SR. This study was also funded by the Norwegian Research Council (NFR)

    Designing assisted living technologies 'in the wild' : preliminary experiences with cultural probe methodology

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    Background There is growing interest in assisted living technologies to support independence at home. Such technologies should ideally be designed ‘in the wild’ i.e. taking account of how real people live in real homes and communities. The ATHENE (Assistive Technologies for Healthy Living in Elders: Needs Assessment by Ethnography) project seeks to illuminate the living needs of older people and facilitate the co-production with older people of technologies and services. This paper describes the development of a cultural probe tool produced as part of the ATHENE project and how it was used to support home visit interviews with elders with a range of ethnic and social backgrounds, family circumstances, health conditions and assisted living needs. Method Thirty one people aged 60 to 98 were visited in their homes on three occasions. Following an initial interview, participants were given a set of cultural probe materials, including a digital camera and the ‘Home and Life Scrapbook’ to complete in their own time for one week. Activities within the Home and Life Scrapbook included maps (indicating their relationships to people, places and objects), lists (e.g. likes, dislikes, things they were concerned about, things they were comfortable with), wishes (things they wanted to change or improve), body outline (indicating symptoms or impairments), home plan (room layouts of their homes to indicate spaces and objects used) and a diary. After one week, the researcher and participant reviewed any digital photos taken and the content of the Home and Life Scrapbook as part of the home visit interview. Findings The cultural probe facilitated collection of visual, narrative and material data by older people, and appeared to generate high levels of engagement from some participants. However, others used the probe minimally or not at all for various reasons including limited literacy, physical problems (e.g. holding a pen), lack of time or energy, limited emotional or psychological resources, life events, and acute illness. Discussions between researchers and participants about the materials collected (and sometimes about what had prevented them completing the tasks) helped elicit further information relevant to assisted living technology design. The probe materials were particularly helpful when having conversations with non-English speaking participants through an interpreter. Conclusions Cultural probe methods can help build a rich picture of the lives and experiences of older people to facilitate the co-production of assisted living technologies. But their application may be constrained by the participant’s physical, mental and emotional capacity. They are most effective when used as a tool to facilitate communication and development of a deeper understanding of older people’s needs

    Analysis of structural transformations during the synthesis of a MoVTeNb mixed oxide calalyst

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    This work presents a detailed investigation of the preparation routine for the multi-metal oxide Mo1V0.30Te0.23Nb0.125Ox used as catalyst for the selective oxidation of propane to acrylic acid. In situ Raman spectroscopy on the initial aqueous polyoxometalate solution prepared from ammonium heptamolybdate, ammonium metavanadate and hexaoxotelluric acid reveals the coexistence of Anderson-type anions [TeM6O24]n−, M = Mo, V; n ≥ 6 and protonated decavanadate species [HxV10O28](6−x)−. Raman analysis showed that the monomeric motif of the Anderson-type tellurate is preserved after addition of the Nb precursor and the subsequent spray-drying process. Calcination of the X-ray amorphous spray-dried material in air at 548 K seems to be the essential step, leading to a re-arrangement of the tellurate building blocks, generating nanocrystalline precursors of the phases finally established during treatment in helium at 873 K

    Protein intake and exercise for optimal muscle function with aging: recommendations from the ESPEN Expert Group.

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    The aging process is associated with gradual and progressive loss of muscle mass along with lowered strength and physical endurance. This condition, sarcopenia, has been widely observed with aging in sedentary adults. Regular aerobic and resistance exercise programs have been shown to counteract most aspects of sarcopenia. In addition, good nutrition, especially adequate protein and energy intake, can help limit and treat age-related declines in muscle mass, strength, and functional abilities. Protein nutrition in combination with exercise is considered optimal for maintaining muscle function. With the goal of providing recommendations for health care professionals to help older adults sustain muscle strength and function into older age, the European Society for Clinical Nutrition and Metabolism (ESPEN) hosted a Workshop on Protein Requirements in the Elderly, held in Dubrovnik on November 24 and 25, 2013. Based on the evidence presented and discussed, the following recommendations are made (a) for healthy older people, the diet should provide at least 1.0-1.2 g protein/kg body weight/day, (b) for older people who are malnourished or at risk of malnutrition because they have acute or chronic illness, the diet should provide 1.2-1.5 g protein/kg body weight/day, with even higher intake for individuals with severe illness or injury, and (c) daily physical activity or exercise (resistance training, aerobic exercise) should be undertaken by all older people, for as long as possible

    Comparison of the substrate-binding pockets of the Rous sarcoma virus and human immunodeficiency virus type 1 proteases

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    A steady state kinetic analysis of the avian myeloblastosis virus/Rous sarcoma virus (AMV/RSV) and human immunodeficiency virus Type 1 (HIV-1) retroviral proteases (PRs) was carried out using a series of 40 peptide substrates that are derivatives of the AMV/RSV nucleocapsid-PR cleavage site. These peptides contain single amino acid substitutions in each of the seven positions of the minimum length substrate required by the PR for specific and efficient cleavage. These peptide substrates are distinguished by the individual enzyme subsites of the AMV/RSV and HIV-1 PRs. The molecular basis for similarities and differences of the individual subsites for both proteases is discussed using steady state kinetic data and modeling based on crystal structures

    MPA in Labor: Securing the Pearl Cays of Nicaragua

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    Implementation of Marine Protected Areas (MPAs) has always a step-zero, i.e., an initial phase when the idea is incepted, communicated and negotiated among stakeholders. What happens during this phase is likely to have an impact later on. If not done right, the management of the MPA may encounter problems at later stage that will be difficult to correct. Inspired by this working theory, this article describes the effort to establish the Pearl Cays off the Caribbean coast of Nicaragua as a protected area. This case-study illustrates the critical actions to be taken during step-zero, i.e., what needs to be considered and done before an MPA is formally declared. The area investigated consists of a number of small islands (cays) and coral reefs, fishing grounds and marine turtle nesting areas. Throughout history, the cays have played an important role in sustaining livelihoods of nearby communities. Although the idea of an MPA was originally conservation, the communities saw it as an opportunity to regain ownership and control of the cays. By Nicaraguan law, in order to establish protected areas, consultation and approval from local people is required. In the case of the Pearl Cays, this has proved difficult. The article demonstrates how MPA initiatives must sometimes relate to already ongoing complex social processes in the area where they are to be instigated

    Digital Avatars for Older People’s Care

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    Es el preprint de: Bertoa M.F., Moreno N., Perez-Vereda A., Bandera D., Álvarez-Palomo J.M., Canal C. (2020) Digital Avatars for Older People’s Care. In: García-Alonso J., Fonseca C. (eds) Gerontechnology. IWoG 2019. Communications in Computer and Information Science, vol 1185. Springer, Cham. doi:10.1007/978-3-030-41494-8_6.The continuous increase in life expectancy poses a challenge for health systems in modern societies, especially with respect to older people living in rural low-populated areas, both in terms of isolation and difficulty to access and communicate with health services. In this paper, we address these issues by applying the Digital Avatars framework to Gerontechnology. Building on our previous work on mobile and social computing, in particular the People as a Service model, Digital Avatars make intensive use of the capabilities of current smartphones to collect information about their owners, and applies techniques of Complex Event Processing extended with uncertainty for inferring the habits and preferences of the user of the phone and building with them a virtual profile. These virtual profiles allow to monitor the well-being and quality of life of older adults, reminding pharmacological treatments and home health testings, and raising alerts when an anomalous situation is detected.This work has been funded by the Spanish Government under grant PGC2018-094905-B-100
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