Universality of Single Spin Asymmetries in Hard Processes

We discuss the use of time reversal symmetry in the classification of parton correlators. Specifically, we consider the role of (small) intrinsic transverse momenta in these correlators and the determination of the proper color gauge link. The transverse momentum weighted correlators in hard processes can be expressed as a product of universal gluonic pole matrix elements and gluonic pole cross sections.Comment: Contributed paper at DIS2006, 4 page

Anisotropic yield functions in a co-rotating reference frame

In metal forming simulations large deformations are often treated based on objective formulations. Large rotations are accounted for by rotating the stress tensor or approximating the rotation by some integration rule for the rate of rotation. For isotropic material behavior, this is easily done. For anisotropic material behavior however, not only the stresses, but also the relation between stress rate and strain rate must be updated. In this case it is easier to take a co-rotating reference frame and apply the constitutive relations on a strain measure that is neutralized for rigid body translations and rotations. This paper presents an algorithm that is based on the latter idea. The algorithm directly uses the increments in the deformation gradient, avoiding as much as possible to take time derivatives that should then be integrated subsequently. The algorithm is applied to a constitutive model including an initial anisotropic yield function and isotropic and kinematic hardening. The kinematic hardening makes use of a maximal back stress surface [1] to account for behavior observed in cyclic loading

Single spin asymmetries in hadron-hadron collisions

We study weighted azimuthal single spin asymmetries in hadron-hadron scattering using the diagrammatic approach at leading order and assuming factorization. The effects of the intrinsic transverse momenta of the partons are taken into account. We show that the way in which $T$-odd functions, such as the Sivers function, appear in these processes does not merely involve a sign flip when compared with semi-inclusive deep inelastic scattering, such as in the case of the Drell-Yan process. Expressions for the weighted scattering cross sections in terms of distribution and fragmentation functions folded with hard cross sections are obtained by introducing modified hard cross sections, referred to as gluonic pole cross sections.Comment: 22 pages, 4 figures; minor text modifications and some additional reference

Ph.D. prepared: research skill development across the undergraduate years

Purpose: Many countries are looking for ways to enable students to engage more effectively with PhD study. This paper aims to consider the effects of explicit discipline-specific research skill development embedded in multiple semesters of an undergraduate degree on PhD preparedness. Design/methodology/approach: This case study of one Bachelor of Health Science programme determined the effectiveness of the implementation of a conceptual model, the Researcher Skill Development framework, across the undergraduate degree programme. Data were gathered through interviews of 9 academic staff and 14 students in their fourth year of undergraduate study, which is a research-focused year. Findings: All students and academics stated the benefits of the use of the Researcher Skill Development framework in undergraduate study including: deepening metacognition of research processes; assisting students toward acting and thinking like researchers; and the research-capacity building of the school. While all academics and all but one student recommended that the framework be used early in the degree programme, a number of interviewees specified problems with the existing implementation of the framework. Research limitations/implications: While the results are not generalisable, the approach is worth studying in other degree programme-wide contexts to determine its broader capacity to enable students to be more research ready for PhD study when compared to current practice. Practical implications: When adapted to the context, whole-of-degree research skill development may enable developing countries to have more students and developed countries to better prepared students commencing PhD studies. Originality/value: No studies currently provide results for explicit research skill development across a degree programme, or of the benefits of this approach for PhD preparation.John Willison, Femke Buisman-Pijlma

Weidegang in de biologische melkgeitenhouderij : resultaten onderzoek 2008

Weidegang is een belangrijk middel in de biologisch melkgeitenhouderij om zich te onderscheiden van gangbare productie en vanaf 2010 verplicht voor alle biologische melkgeitenhouders. Het weiden met geiten blijkt in de praktijk moeilijk vanwege met name arbeid, droge stof opname en maagdarmwormen. In Frankrijk is veel onderzoek gedaan naar weidegang met melkgeiten. Dit onderzoek is gedaan om informatie te winnen rondom weidegang in Nederland en dit te kunnen vergelijken met Franse literatuur. Uit het onderzoek kan over het algemeen worden geconcludeerd dat grasopname cijfers uit Frans onderzoek hoger zijn, en niet overeen komen met Nederland, en dus zijn de beweidingsadviezen uit Frankrijk niet volledig te gebruiken. Groei en totale droge stof opname van lammeren lijkt overeen te komen. Het graasgedrag gedurende de dag in Frankrijk lijkt deels overeen te komen met Nederland, maar doordat de weidedag korter was in Nederland waren er verschillen. Met name het graasgedrag in de namiddag/ avond van melkgeiten was in Nederland minde

Edible insects unlikely to contribute to transmission of coronavirus SARS-CoV-2

In the context of food safety, edible insects are evaluated for biological hazards such as microbial pathogens according to regulations currently in place. When the European Food Safety Authority evaluated the hazards of edible insects as a potential source of pathogenic viruses for humans and livestock, the novel zoonotic coronavirus SARS-CoV-2 had not yet emerged but other pathogenic coronaviruses such as SARS (SARS-CoV) and MERS (MERS-CoV) were known. As a result of the COVID-19 pandemic, animal sources of protein for human consumption are being evaluated for the risks of being a transmission vector of coronaviruses, like SARS-CoV-2. Insects lack a receptor that can bind SARS-CoV-2, thus preventing the virus from replicating in insects, unlike some vertebrate livestock species and companion animals. Despite extensive monitoring, coronaviruses have never been recorded in insect microbiomes. Contamination of insects produced for food or feed may occur during the production process, resulting from rearing substrate or from insect farmers. However, the currently permitted rearing substrates do not include animal products and the farming process is highly automated, thus limiting interactions between farmers and insects. If contamination would still occur, the fact that the insects in production are not hosts to SARS-CoV-2 precludes virus replication and the further processing of the insects will destroy the contamination. We conclude that the hazard of edible insects being a transmission vector of SARS-CoV-2 is extremely low.</p

Soil nitrogen supply of peat grasslands estimated by degree days and soil organic matter content

Accurate estimates of the quantity and rate of soil nitrogen supply (SNS) are essential to increase soil and farm N use efficiencies, in particular for soils high in organic matter. The objective of this work was to enhance the empirical understanding of the SNS of dairy grasslands on peat soils, using soil properties and weather variables. Data were collected from studies on herbage N uptake carried out between 1992 and 2017 in the western peat district of the Netherlands. For the period between March to mid October, SNS was estimated from the sum of mean growing season daily temperatures, soil organic matter (SOM) and applied calcium ammonium nitrate (CAN) N with a residual standard error of 25–27 kg ha−1. Each °C growing season temperature sum affected SNS by 78–90 g ha−1 and each g SOM per 100 g dry soil affected SNS by 3.6–3.9 kg ha−1, respectively. SNS was equally estimated for conditions with and without CAN fertilisation. Validation with data from independent field trials showed similar impacts of SOM and growing season temperature sum on SNS. The error of prediction of the presented models, however, was still too large for direct on-farm application and led to underestimations for a specific site. Nevertheless, the obtained models allow for an increased understanding of soil and farm N balances. The models can therefore be used for improved temporal and spatial SNS-adapted farming practice advice, which can potentially lead to reduced soil and farm N surpluses.</p

Individual differences underlying susceptibility to addiction: Role for the endogenous oxytocin system

AbstractRecent research shows that the effects of oxytocin are more diverse than initially thought and that in some cases oxytocin can directly influence the response to drugs and alcohol. Large individual differences in basal oxytocin levels and reactivity of the oxytocin system exist. This paper will review the literature to explore how individual differences in the oxytocin system arise and examine the hypothesis that this may mediate some of the individual differences in susceptibility to addiction and relapse.Differences in the oxytocin system can be based on individual factors, e.g. genetic variation especially in the oxytocin receptor, age or gender, or be the result of early environmental influences such as social experiences, stress or trauma. The paper addresses the factors that cause individual differences in the oxytocin system and the environmental factors that have been identified to induce long-term changes in the developing oxytocin system during different life phases.Individual differences in the oxytocin system can influence effects of drugs and alcohol directly or indirectly. The oxytocin system has bidirectional interactions with the stress-axis, autonomic nervous system, neurotransmitter systems (e.g. dopamine, serotonin and GABA/glutamate) and the immune system. These systems are all important, even vital, in different phases of addiction.It is suggested that early life adversity can change the development of the oxytocin system and the way it modulates other systems. This in turn could minimise the negative feedback loops that would normally exist. Individuals may show only minor differences in behaviour and function unless subsequent stressors or drug use challenges the system. It is postulated that at that time individual differences in oxytocin levels, reactivity of the system or interactions with other systems can influence general resilience, drug effects and the susceptibility to develop problematic drug and alcohol use

Oxytocin as an indicator of psychological and social well-being in domesticated animals: a critical review

Mini reviewOxytocin is often portrayed as a hormone specific to social behavior, reflective of positive welfare states, and linked to mental states. Research on oxytocin in domesticated animal species has been few to date but is rapidly increasing (in dog, pig, cattle, sheep), with direct implications for animal welfare. This review evaluates the evidence for the specificity of oxytocin as an indicator of: 1. Social, 2. Positive, and 3. Psychological well-being. Oxytocin has most often been studied in socially relevant paradigms, with a lack of non-social control paradigms. Oxytocin research appears biased toward investigating positive valence, with a lack of control in valence or arousal. Oxytocin actions are modulated by the environmental and social contexts, which are important factors to consider. Limited evidence supports that oxytocin's actions are linked to psychological states; nevertheless whether this is a direct effect of oxytocin per se remains to be demonstrated. Overall, it is premature to judge oxytocin's potential as an animal welfare indicator given the few and discrepant findings and a lack of standardization in methodology. We cover potential causes for discrepancies and suggest solutions through appropriate methodological design, oxytocin sampling or delivery, analysis and reporting. Of particular interest, the oxytocinergic system as a whole remains poorly understood. Appreciation for the differences that social contact and group living pose in domesticated species and the way they interact with humans should be key considerations in using oxytocin as a psychosocial indicator of well-being.Jean-Loup Rault, Marleen van den Munkhof and Femke T. A. Buisman-Pijlma