University of Portsmouth

About: University of Portsmouth is a education organization based out in Portsmouth, Portsmouth, United Kingdom. It is known for research contribution in the topics: Population & Galaxy. The organization has 5452 authors who have published 14256 publications receiving 424346 citations. The organization is also known as: Portsmouth and Gosport School of Science and Art & Portsmouth and Gosport School of Science and the Arts.

Determinants of Grain Production and Technical Efficiency in China

Abstract: A stochastic frontier production function is used to investigate the prospect to bring China's grain production and productivity to higher levels using a panel data set on 30 provinces from 1987–92. Given an irreversible trend of declining agricultural land, the only feasible way to raise total grain output is to increase land productivity if China does not want to rely on large-scale imports to feed her huge and still growing population. Considerable regional differences in grain yields suggest that there is still a vast potential for raising grain output. The short term solution is to use more land-augmenting inputs such as fertilisers and irrigation in the medium and low yield regions. However, the law of diminishing returns is in operation as more physical inputs are applied to shrinking land. Growth in grain output in the long term must rely on improvements in technical efficiency.

Mindfulness, Eating Behaviours, and Obesity: A Review and Reflection on Current Findings.

Abstract: Mindfulness and mindful eating have become popular in recent years. In this review, we first explore what mindfulness is in the context of psychological research, and why it offers promise for eating behaviours and weight loss. Second, we review the main empirical findings for weight loss in mindfulness-based intervention programmes. Third, contradictions in the findings are explored in more depth, and suggestions are made regarding why they may be occurring. Fourth, the benefits of adding self-compassion (and compassion) training to mindfulness practise to assist weight loss is discussed. Finally, the limitations of the research literature (and possible solutions) are explored. Overall, it is concluded that while mindfulness meditations that specifically focus on eating may be extremely helpful in promoting better eating behaviours, and assist in weight regulation, work is still needed to make such interventions appeal to a wider audience.

A Choice Modeling Application for Greek Heritage Attractions

Abstract: The article adopts a discrete choice modeling methodology with a focus on capturing systematic heterogeneity to evaluate tourists’ preferences for two Greek heritage attractions. This methodology provides useful insights on the preferences of tourists belonging in different demand segments while also providing direction for future policy making in this area. The article presents empirical justification for the frequently cited argument for adopting a more customer-oriented rationale for the optimal use of heritage resources. Overall, the article supports the claim that tourists value positively the introduction of services and amenities that improve the quality of customer service. Thus, policy makers and heritage managers should pay more attention to visitors’ needs and their particular requirements.

Axons and astrocytes release ATP and glutamate to evoke calcium signals in NG2-glia.

Abstract: NG2-glia are an abundant population of cells in the adult CNS that make up a novel glial cell type. Here, we have examined calcium signals in NG2-glia identified by expression of the fluorescent protein DsRed under the control of the NG2 promoter in the white matter of the mouse optic nerve. We focused on mice aged postnatal day (P)12-16, after the main period of oligodendrocyte generation. Using fluo-4 and fura-2 calcium imaging in isolated intact nerves, we show that glutamate and ATP evoke Ca(2+) signals in NG2-glia in situ, acting on AMPA-type glutamate receptors and P2Y(1) and P2X(7) purine receptors; NMDA evoked a weak Ca(2+) signal in a small proportion of NG2-glia. We show that axonal action potentials and mechanical stimulation of astrocytes effect the release of glutamate and ATP to act on NG2-glia; ATP alone evokes robust Ca(2+) signals, whereas glutamate did not unless AMPA receptor desensitization was blocked with cyclothiazide. We identify the precise contacts that NG2-glia form with axons at nodes of Ranvier, and the intricate bipartite sheaths formed between the processes of NG2-glia and astrocytes. In addition, we provide evidence that NG2-glia express synaptophysin, indicating they have mechanisms for transmitting as well as receiving signals. This study places NG2-glia within a neuron-glial network, and identifies roles for glutamate and ATP in communication with astrocytes as well as axons.