1,914 research outputs found
Human response and adaptation to drought in the arid zone: lessons from southern Africa
Human adaptation and response to drought is primarily through evasion or endurance. A review of historical agricultural practices in southern Africa demonstrates evidence of drought evasion response strategies in well-established transhumance routes, where herders move livestock on a seasonal basis in order to exploit resources subject to different climatic regimes. European settlers to the arid regions of South Africa quickly recognised the necessity of these evasion options to survive drought, and adopted the transhumance practices of indigenous farmers. Areas of geographically diverse resource bases became hotly contested by settlers and indigenous farmers. The success of evasion systems are shown to hinge on good social and institutional support structures. When movement is not an option, drought endurance is pursued by attempting to limit the damage to the natural resource base. This is through a number of means such as forage conservation, varying livestock types and numbers, water and soil conservation and taking up alternative livelihood options. State responses to drought over the last century reflect the general South African pattern of racially divided and unjust policies relating to resource access. Historically the state provided considerable support to white commercial farmers. This support was frequently contradictory in its aims and generally was inadequate to enable farmers to cope with drought. Since the advent of democracy in 1994, the state has intervened less, with some support extended to previously disadvantaged and poor communal farmers. Climate change predictions suggest an increase in drought, suggesting that the adoption of mitigating strategies should be a matter of urgency. To do this South Africa needs to build social and institutional capacity, strive for better economic and environmental sustainability, embed drought-coping mechanisms into land restitution policy to ensure the success of this programme, and acknowledge the diversity of the agricultural sector
Influence of addition of plasmin or mastitic milk to cheesemilk on quality of smear-ripened cheese
peer-reviewedSmear-ripened cheese varieties are characterised by the growth of a smear culture, containing
predominantly Brevibacterium linens, on the cheese surface during ripening. In such cheese,
considerable zonal differences in biochemistry of ripening exist, due to moisture loss from, and
growth and metabolic activity of smear microflora at, the cheese surface. In this study, the effects of
adding exogenous plasmin or small amounts of mastitic milk to good quality milk on the quality of
smear-ripened cheese made subsequently was examined. Addition of plasmin did not influence
cheese composition immediately after manufacture, but slightly decreased the rate of moisture loss
during cheese ripening. Plasmin activity decreased during the early stages of ripening, but subsequently
increased towards the end of ripening, perhaps due to changing pH conditions in the cheese.
Addition of plasmin increased rates of primary proteolysis in cheese, as measured by levels of pH 4.6-
soluble N and urea-PAGE, although production of later products of proteolysis appeared less affected.
Addition ofmastitic milk had largely similar effects to addition of exogenous plasmin, which
may reflect a high content of plasmin or plasminogen activators in such milk. Overall, changes in
milk quality and enzymology appear to influence the quality of smear-ripened cheese
Quiescence: early evolutionary origins and universality do not imply uniformity
Cell cycle investigations have focused on relentless exponential proliferation of cells, an unsustainable situation in nature. Proliferation of cells, whether microbial or metazoan, is interrupted by periods of quiescence. The vast majority of cells in an adult metazoan lie quiescent. As disruptions in this quiescence are at the foundation of cancer, it will be important for the field to turn its attention to the mechanisms regulating quiescence. While often presented as a single topic, there are multiple forms of quiescence each with complex inputs, some of which are tied to conceptually challenging aspects of metazoan regulation such as size control. In an effort to expose the enormity of the challenge, I describe the differing biological purposes of quiescence, and the coupling of quiescence in metazoans to growth and to the structuring of tissues during development. I emphasize studies in the organism rather than in tissue culture, because these expose the diversity of regulation. While quiescence is likely to be a primitive biological process, it appears that in adapting quiescence to its many distinct biological settings, evolution has diversified it. Consideration of quiescence in different models gives us an overview of this diversity
Above ground perennial plant biomass across an altitudinal and land-use gradient in Namaqualand South Africa
This study set out to generate estimates of the standing perennial biomass for six different vegetation types, and associated upland and lowland habitats, across the altitudinal gradient presented by the Kamiesberg mountain range in the Namaqualand region of the Northern Cape Province of South Africa. Volume-biomass regressions, established for 94 perennial species accounting for 70–80% of the plant cover, were used to generate these estimations. Comparisons to other studies give similar findings, corroborating the method adopted. Biomass was found to vary significantly in relation to the altitudinal, and associated rainfall, gradient, as well as by habitat type where the rocky uplands have considerably more biomass that the sandy lowland habitats. An examination of the impact of sustained heavy grazing associated with a communal rangeland on this standing perennial biomass, showed a significant decrease in on the lowland habitats. This loss in biomass is principally of palatable species, with no evidence of a response in terms of perennial biomass. These findings point to degradation on the lowland habitats of the communal rangeland, with negative consequences for livestock farmers in the region
Evidence for Dirac nodes from quantum oscillations in SrFe2As2
We present a detailed study of quantum oscillations in the antiferromagnetically ordered pnictide compound SrFe2As2 as the angle between the applied magnetic field and crystalline axes is varied. Our measurements were performed on high-quality single crystals in a superconducting magnet, and in pulsed magnetic fields up to 60 T, allowing us to observe orbits from several small Fermi-surface pockets. We extract the cyclotron effective mass m☆ and frequency F for these orbits and track their values as the field is rotated away from the c axis. While a constant ratio of m☆/F is expected for a parabolic band, we observe deviations from this behavior. We conclude that this observation points to orbits derived from a band with Dirac dispersion near the Fermi level
Developing research priorities for palliative care of people with intellectual disabilities in Europe: a consultation process using nominal group technique
BACKGROUND:
Empirical knowledge around palliative care provision and needs of people with intellectual disabilities is extremely limited, as is the availability of research resources, including expertise and funding. This paper describes a consultation process that sought to develop an agenda for research priorities for palliative care of people with intellectual disabilities in Europe.
METHODS:
A two-day workshop was convened, attended by 16 academics and clinicians in the field of palliative care and intellectual disability from six European countries. The first day consisted of round-table presentations and discussions about the current state of the art, research challenges and knowledge gaps. The second day was focused on developing consensus research priorities with 12 of the workshop participants using nominal group technique, a structured method which involved generating a list of research priorities and ranking them in order of importance.
RESULTS:
A total of 40 research priorities were proposed and collapsed into eleven research themes. The four most important research themes were: investigating issues around end of life decision making; mapping the scale and scope of the issue; investigating the quality of palliative care for people with intellectual disabilities, including the challenges in achieving best practice; and developing outcome measures and instruments for palliative care of people with intellectual disabilities.
CONCLUSIONS:
The proposal of four major priority areas and a range of minor themes for future research in intellectual disability, death, dying and palliative care will help researchers to focus limited resources and research expertise on areas where it is most needed and support the building of collaborations. The next steps are to cross-validate these research priorities with people with intellectual disabilities, carers, clinicians, researchers and other stakeholders across Europe; to validate them with local and national policy makers to determine how they could best be incorporated in policy and programmes; and to translate them into actual research studies by setting up European collaborations for specific studies that require such collaboration, develop research proposals and attract research funding
Perinatal mortality in Ireland. Annual report 2014.
Perinatal mortality refers to the death of babies in the weeks before or after birth. Perinatal mortality includes stillbirths (babies born with no signs of life after 24 weeks of pregnancy or weighing at least 500 grams) and the deaths of babies within 28 days of being born. Perinatal mortality is an important indicator of the quality of obstetric and neonatal care. Measurement of the outcome of care is central to the development of safe and high quality healthcare services. In recent years, the National Perinatal Epidemiology Centre (NPEC) has worked with colleagues in developing an in-depth clinical audit of perinatal mortality.
Smoking and substance use - page 2
Emotions and ethics: A Foucauldian framework for becoming an ethical educator
This paper provides examples of how a teacher and a principal construct their ‘ethical selves’. In doing so we demonstrate how Foucault's four-part ethical framework can be a scaffold with which to actively connect emotions to a personal ethical position. We argue that ethical work is and should be an ongoing and dynamic life long process rather than a more rigid adherence to a ‘code of ethics’ that may not meaningfully engage its adherents. We use Foucault's four-part framework of ethical practice as a framework through which an ‘ethical self’ can be purposely constructed. This is important work, as those who have authority over others must know how to monitor themselves against the misuse of the power of their positions
Pilot-aided estimation and equalisation of a Radio-over-Fibre system in Wideband Code Division Multiple Access
In this study, the impact of a Radio-over-Fibre (RoF) subsystem on the capacity performance of wideband code division multiple access is evaluated. This study investigates the use of pilot-aided channel estimation to compensate for the optical subsystem non-linearities for different channel conditions, estimation intervals and coding schemes. The results show that pilot-aided channel estimation is an effective method for compensating the composite impairments of the optical subsystem and the radio frequency (RF) channel. It is found that there is always a suitable pilot power level which maximises the system capacity performance regardless of coding scheme and channel condition. Also, the peak capacity is only slightly affected by a decrease in the estimation interval
Plural valuation of nature for equity and sustainability: Insights from the Global South
Plural valuation is about eliciting the diverse values of nature articulated by different stakeholders in order to inform decision making and thus achieve more equitable and sustainable outcomes. We explore what approaches align with plural valuation on the ground, as well as how different social-ecological contexts play a role in translating plural valuation into decisions and outcomes. Based on a co-constructed analytical approach relying on empirical information from ten cases from the Global South, we find that plural valuation contributes to equitable and sustainable outcomes if the valuation process: 1) is based on participatory value elicitation approaches; 2) is framed with a clear action-oriented purpose; 3) provides space for marginalized stakeholders to articulate their values in ways that can be included in decisions; 4) is used as a tool to identify and help reconcile different cognitive models about human-nature relations; and 5) fosters open communication and collaboration among stakeholders. We also find that power asymmetries can hinder plural valuation. As interest and support for undertaking plural valuation grows, a deeper understanding is needed regarding how it can be adapted to different purposes, approaches, and social-ecological contexts in order to contribute to social equity and sustainability
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