Performance and selection of winter durum wheat genotypes in different European conventional and organic fields

Sustainability is a key factor for the future of agriculture. Productivity in agriculture has more than tripled in developed countries since the 1950s. Beyond the success of plant breeding, the increased use of inorganic fertilizers, application of pesticides, and spread of irrigation also contributed to this success. However, impressive yield increases started to decline in the 1980s because of the lack of sustainability. One of the most beneficial ways to increase sustainability is organic agriculture. In such agro-ecosystem-based holistic production systems the prerequisite of successful farming is the availability of crop genotypes that perform well. However, selection of winter durum wheat for sub-optimal growing conditions is still mainly neglected, and the organic seed market also lacks of information on credibly tested winter durum varieties suitable for organic agriculture

Indication for π+π−\pi^+ \pi^- scattering in p+pp+p collisions at sNN=\sqrt{s_{_{NN}}} = 200 GeV

A $\rho(770)^0$ mass shift of about -40 MeV/$c^2$ was measured in $p+p$ collisions at $\sqrt{s_{_{NN}}} =$ 200 GeV at RHIC. Previous mass shifts have been observed at CERN-LEBC-EHS and CERN-LEP. We will show that phase space does not account for the $\rho(770)^0$ mass shift measured at RHIC, CERN-LEBC-EHS and CERN-LEP and conclude that there are significant scattering interactions in $p+p$ collisions.Comment: 11 pages and 7 figure

"It's a revolving door": Ego-depletion among prisoners with injecting drug use histories as a barrier to post-release success

Background: People who inject drugs (PWID) are overrepresented among prisoner populations worldwide. This qualitative study used the psychological concept of “ego-depletion” as an exploratory framework to better understand the disproportionate rates of reincarceration among people with injecting drug use histories. The aim was to illuminate mechanisms by which prospects for positive post-release outcomes for PWID are enhanced or constricted. Methods: Participants were recruited from a longitudinal cohort study, SuperMIX, in Victoria, Australia. Eligible participants were invited to participate in an in-depth interview. Inclusion criteria were: aged 18+; lifetime history of injecting drug use; incarcerated for >three months and released from custody <12 months previously. Analysis of 48 interviews examined how concepts relevant to the ego-depletion framework (self-regulation; standards; consequences and mitigators of ego-depletion) manifested in participants’ narratives. Results: Predominantly, participants aimed to avoid a return to problematic drug use and recidivism, and engaged in effortful self-regulation to pursue their post-release goals. Post-release environments were found to diminish self-regulation resources, leading to states of ego-depletion and compromising the capacity to self-regulate according to their ideals. Fatalism, stress, and fatigue associated with the transition period exacerbated ego-depletion. Strategies that mitigated ego-depletion included avoidance of triggering environments; reducing stress through opioid agonist therapy; and fostering positive affect through supportive relationships. Conclusions: Post-release environments are ego-depleting and inconducive to sustaining behavioural changes for PWID leaving prison. Corrections’ behaviourist paradigms take insufficient account of the socio-structural factors impacting on an individual's self-regulation capacities in the context of drug dependence and desistance processes. Breaking the cycles of reincarceration among PWID requires new approaches that moderate ego-depletion and facilitate long-term goal-pursuit

Replica theory for learning curves for Gaussian processes on random graphs

Statistical physics approaches can be used to derive accurate predictions for the performance of inference methods learning from potentially noisy data, as quantified by the learning curve defined as the average error versus number of training examples. We analyse a challenging problem in the area of non-parametric inference where an effectively infinite number of parameters has to be learned, specifically Gaussian process regression. When the inputs are vertices on a random graph and the outputs noisy function values, we show that replica techniques can be used to obtain exact performance predictions in the limit of large graphs. The covariance of the Gaussian process prior is defined by a random walk kernel, the discrete analogue of squared exponential kernels on continuous spaces. Conventionally this kernel is normalised only globally, so that the prior variance can differ between vertices; as a more principled alternative we consider local normalisation, where the prior variance is uniform

Probabilistic models of information retrieval based on measuring the divergence from randomness

We introduce and create a framework for deriving probabilistic models of Information Retrieval. The models are nonparametric models of IR obtained in the language model approach. We derive term-weighting models by measuring the divergence of the actual term distribution from that obtained under a random process. Among the random processes we study the binomial distribution and Bose--Einstein statistics. We define two types of term frequency normalization for tuning term weights in the document--query matching process. The first normalization assumes that documents have the same length and measures the information gain with the observed term once it has been accepted as a good descriptor of the observed document. The second normalization is related to the document length and to other statistics. These two normalization methods are applied to the basic models in succession to obtain weighting formulae. Results show that our framework produces different nonparametric models forming baseline alternatives to the standard tf-idf model

The effects of parasitism and body length on positioning within wild fish shoals

The influence of body length and parasitism on the positioning behaviour of individuals in wild fish shoals was investigated by a novel means of capturing entire shoals of the banded killifish (Fundulus diaphanus, Lesueur) using a grid-net that maintained the two-dimensional positions of individuals within shoals. Fish in the front section of a shoal were larger than those in the rear. Individuals parasitized by the digenean trematode (Crassiphiala bulboglossa, Haitsma) showed a tendency to occupy the front of shoals. Parasitized fish were also found more in peripheral positions than central ones in a significant number of shoals. Shoal geometry was affected by the overall parasite prevalence of shoal members; shoals with high parasite prevalence displayed increasingly phallanx-like shoal formations, whereas shoals with low prevalence were more elliptical. There was no relationship between body length and parasite abundance or prevalence in the fish population which suggests body length and parasite status are independent predictors of positioning behaviour. Solitary individuals found outside shoals were both more likely to be parasitized and had higher parasite abundance than individuals engaged in shoaling. Differences in the shoaling behaviour of parasitized and unparasitized fish are discussed in the context of the adaptive manipulation hypothesis