The case for grazing dairy cows

The case for grazing dairy cows at pasture is reviewed in six categories: i) Optimal land use for food production; ii) Soil carbon sequestration; iii) Carbon footprint; iv) Animal health and welfare; v) Effects on human health of milk produced from grazed pasture; vi) Consumer demand for milk from grazed cows. Land best-suited to grazing is uncultivatable peaty soil receiving relatively low levels of fertilisation. With soil carbon sequestration, carbon footprint is lower for grazing than for other systems of milk production. Some indices of animal health and welfare (e.g. lameness, status of hock integument) are influenced positively by extent of grazing. Benefits to human health may accrue from higher levels of essential amino acids, carotenoids, omega-3 fatty acids and conjugated linoleic acid in milk from cows given pasture compared to diets based on silage and concentrates. Milk producers, processors and supermarkets are responding to consumer demand for milk and milk products from cows given access to pasture during the grazing season. The major constraint to milk production from grazing is energy intake. Research opportunities to address this constraint include application of remote sensing and artificial intelligence to grazing managemen

Understanding Terrorist Organizations with a Dynamic Model

Terrorist organizations change over time because of processes such as recruitment and training as well as counter-terrorism (CT) measures, but the effects of these processes are typically studied qualitatively and in separation from each other. Seeking a more quantitative and integrated understanding, we constructed a simple dynamic model where equations describe how these processes change an organization's membership. Analysis of the model yields a number of intuitive as well as novel findings. Most importantly it becomes possible to predict whether counter-terrorism measures would be sufficient to defeat the organization. Furthermore, we can prove in general that an organization would collapse if its strength and its pool of foot soldiers decline simultaneously. In contrast, a simultaneous decline in its strength and its pool of leaders is often insufficient and short-termed. These results and other like them demonstrate the great potential of dynamic models for informing terrorism scholarship and counter-terrorism policy making.Comment: To appear as Springer Lecture Notes in Computer Science v2: vectorized 4 figures, fixed two typos, more detailed bibliograph

Can cohort data be treated as genuine panel data?

If repeated observations on the same individuals are not available it is not possible to capture unobserved individual characteristics in a linear model by using the standard fixed effects estimator. If large numbers of observations are available in each period one can use cohorts of individuals with common characteristics to achieve the same goal, as shown by Deaton (1985). It is tempting to analyze the observations on cohort averages as if they are observations on individuals which are observed in consecutive time periods. In this paper we analyze under which conditions this is a valid approach. Moreover, we consider the impact of the construction of the cohorts on the bias in the standard fixed effects estimator. Our results show that the effects of ignoring the fact that only a synthetic panel is available will be small if the cohort sizes are sufficiently large (100, 200 individuals) and if the true means within each cohort exhibit sufficient time variation

Origin of intermittent accretion-powered X-ray oscillations in neutron stars with millisecond spin periods

We have shown previously that many of the properties of persistent accretion-powered millisecond pulsars can be understood if their X-ray emitting areas are near their spin axes and move as the accretion rate and structure of the inner disk vary. Here we show that this "nearly aligned moving spot model" may also explain the intermittent accretion-powered pulsations that have been detected in three weakly magnetic accreting neutron stars. We show that movement of the emitting area from very close to the spin axis to about 10 degrees away can increase the fractional rms amplitude from less than about 0.5 percent, which is usually undetectable with current instruments, to a few percent, which is easily detectable. The second harmonic of the spin frequency usually would not be detected, in agreement with observations. The model produces intermittently detectable oscillations for a range of emitting area sizes and beaming patterns, stellar masses and radii, and viewing directions. Intermittent oscillations are more likely in stars that are more compact. In addition to explaining the sudden appearance of accretion-powered millisecond oscillations in some neutron stars with millisecond spin periods, the model explains why accretion-powered millisecond oscillations are relatively rare and predicts that the persistent accretion-powered millisecond oscillations of other stars may become undetectable for brief intervals. It suggests why millisecond oscillations are frequently detected during the X-ray bursts of some neutron stars but not others and suggests mechanisms that could explain the occasional temporal association of intermittent accretion-powered oscillations with thermonuclear X-ray bursts.Comment: 5 pages, 1 figure; includes additional discussion and updated references; accepted for publication in ApJ

Screening and assessment tools for gaming disorder: A comprehensive systematic review

The inclusion of gaming disorder (GD) as an official diagnosis in the ICD-11 was a significant milestone for the field. However, the optimal measurement approaches for GD are currently unclear. This comprehensive systematic review aimed to identify and evaluate all available English-language GD tools and their corresponding evidence. A search of PsychINFO, PsychArticles, ScienceDirect, Scopus, Web of Science, and Google Scholar identified 32 tools employed in 320 studies (N = 462,249 participants). The evaluation framework examined tools in relation to: (1) conceptual and practical considerations; (2) alignment with DSM-5 and ICD-11 criteria; (3) type and quantity of studies and samples; and (4) psychometric properties. The evaluation showed that GD instrumentation has proliferated, with 2.5 tools, on average, published annually since 2013. Coverage of DSM-5 and ICD-11 criteria was inconsistent, especially for the criterion of continued use despite harm. Tools converge on the importance of screening for impaired control over gaming and functional impairment. Overall, no single tool was found to be clearly superior, but the AICA-Sgaming, GAS-7, IGDT-10, IGDS9-SF, and Lemmens IGD-9 scales had greater evidential support for their psychometric properties. The GD field would benefit from a standard international tool to identify gaming-related harms across the spectrum of maladaptive gaming behaviors.Peer reviewedFinal Accepted Versio

Multi-phonon Raman scattering in semiconductor nanocrystals: importance of non-adiabatic transitions

Multi-phonon Raman scattering in semiconductor nanocrystals is treated taking into account both adiabatic and non-adiabatic phonon-assisted optical transitions. Because phonons of various symmetries are involved in scattering processes, there is a considerable enhancement of intensities of multi-phonon peaks in nanocrystal Raman spectra. Cases of strong and weak band mixing are considered in detail. In the first case, fundamental scattering takes place via internal electron-hole states and is participated by s- and d-phonons, while in the second case, when the intensity of the one-phonon Raman peak is strongly influenced by the interaction of an electron and of a hole with interface imperfections (e. g., with trapped charge), p-phonons are most active. Calculations of Raman scattering spectra for CdSe and PbS nanocrystals give a good quantitative agreement with recent experimental results.Comment: 16 pages, 2 figures, E-mail addresses: [email protected], [email protected], [email protected], accepted for publication in Physical Review

Exploring network structure and the role of key stakeholders to understand the obesity prevention system in an Australian metropolitan health service: Study protocol

Introduction: Little progress has been made to address the increasing obesity prevalence over the past few decades, and there is growing concern about the far-reaching consequences for health and well-being related to obesity on a global scale. Systems thinking is emerging as a suitable approach for obesity prevention, as it allows health researchers, practitioners and policy-makers to systematically synthesise existing data, expose gaps, inform priority setting and identify leverage points in the system. The aim of this study is to trial a systems thinking approach to better understand the local obesity prevention system, and identify gaps and viable opportunities for health promotion activities to strengthen obesity prevention efforts in an Australian metropolitan health service. Methods and analysis: A mixed methods design will be undertaken in a metropolitan health service area in Perth, Western Australia in 2019-2020. A systems inventory audit will be used to identify physical activity, nutrition and overweight/obesity prevention activities taking place in the study area. An organisational network survey will be administered, and a social network analysis undertaken to examine relationships between organisations in the network. The relationships and interactions will compare the level and type of interactions each organisation has within the network. Parameters including density, centrality and betweenness will be computed using UCINET and Netdraw. Ethics and dissemination: Ethics approval has been obtained from the Curtin University Human Research Ethics Committee (approval number HRE2017-0862). Results will be reviewed with members of the advisory group, submitted to relevant journals and presented at relevant conferences to health promotion practitioners and policy-makers. The area health service, as co-producers of the research, will use findings to inform policy and strategy across the study area