Reservaatbeheer met zoogkoeien kost geld

Bij de huidige vleesprijzen zijn de opbrengsten van de vleesveehouderij laag en kan een zoogkoeienhouder geen pacht betalen, maar moet hij een vergoeding krijgen om met het begrazen van natuurterreinen een inkomen te halen

Emotional Strategies as Catalysts for Cooperation in Signed Networks

The evolution of unconditional cooperation is one of the fundamental problems in science. A new solution is proposed to solve this puzzle. We treat this issue with an evolutionary model in which agents play the Prisoner's Dilemma on signed networks. The topology is allowed to co-evolve with relational signs as well as with agent strategies. We introduce a strategy that is conditional on the emotional content embedded in network signs. We show that this strategy acts as a catalyst and creates favorable conditions for the spread of unconditional cooperation. In line with the literature, we found evidence that the evolution of cooperation most likely occurs in networks with relatively high chances of rewiring and with low likelihood of strategy adoption. While a low likelihood of rewiring enhances cooperation, a very high likelihood seems to limit its diffusion. Furthermore, unlike in non-signed networks, cooperation becomes more prevalent in denser topologies.Comment: 24 pages, Accepted for publication in Advances in Complex System

Tunable Polaronic Conduction in Anatase TiO2

Oxygen vacancies created in anatase TiO2 by UV photons (80–130 eV) provide an effective electron-doping mechanism and induce a hitherto unobserved dispersive metallic state. Angle resolved photoemission reveals that the quasiparticles are large polarons. These results indicate that anatase can be tuned from an insulator to a polaron gas to a weakly correlated metal as a function of doping and clarify the nature of conductivity in this material.open1192sciescopu

Détermination de l’âge de l’aulacode (Thryonomys swinderianus

Dans le but de déterminer l’âge de l’aulacode (Thryonomys swinderianus Temminck, 1827) au Bénin, une étude a été réalisée sur les caractères morphométriques tels que la longueur tête-corps (LTC), la longueur de la queue (LQ), la longueur de l’oreille (LO), la longueur du pied postérieur gauche (LPPG) sans les griffes, le pourtour du cou (PC), le pourtour de la tête (PT), le pourtour thoracique (Pth) et le poids vif corporel de l’aulacode. Tous ces paramètres ont été mesurés et pris à l’aide d’un mètre ruban, d’un pied à coulisse et d’un peson après anesthésie de 202 mâles et de 188 femelles âgés de 2 semaines à 12 mois. Des résultats obtenus, il ressort qu’une forte corrélation existe d’une part entre les différents caractères avec un coefficient de détermination variant entre 0,764 et 0,968 et d’autre part entre l’âge de l’animal et ces caractères avec un coefficient de détermination variant entre 0,858 et 0,954. Chez l’aulacode femelle, en prenant en compte un seul caractère, les deux meilleures équations données par le Modèle Linéaire Simple (MLS) ont été Age = 3,383 + 0,015PV, avec R2 = 0,56 et Age = 3,403 + 0,043PM, avec R2 = 0,58. Celles obtenues avec deux caractères ont été les suivantes : Age = -1,481 + 0,098LPPG + 0,014PV, avec R2 = 0,56 ; Age = -11,524 + 0,128PT + 0,010PV, avec R2 = 0,56 ; Age = -1,491 + 0,108LPPG + 0,041PM, avec R2 = 0,57 ; Age = -11,544 + 0,148PT + 0,032PM, avec R2 = 0,58. Celles obtenues avec trois caractères ont été Age = 6,488 - 0,164LQ + 0,385LPPG + 0,016PV, avec R2 = 0,57, Age = 6,498 - 0,174LQ + 0,395LPPG + 0,046PM, avec R2 = 0,59 et Age = -11,479 + 0,035LPPG + 0,141PT + 0,032PM, avec R2 = 0,59. Celle donnée par le Modèle Linéaire Généralisé (MLG) en prenant en compte un seul caractère a été Age= e0,248 + 0,016PC avec AIC = 1.972,9 et celle obtenue avec deux caractères a été Age= e0,033 + 0,013LPPG + 0,011PT avec AIC = 1.944. Les équations de régression ainsi élaborées peuvent être utilisées pour estimer l’âge de l’aulacode.Mots clés : Aulacode, caractères morphométriques, estimation de l’âge, corrélation, modèle de régression, équations de prédiction, Bénin

Determination of grasscutter age (Thryonomys swinderianus Temminck, 1827) from anogenital distance

Objectives: The global objective of the survey was to determine the grasscutter age from the anogenital distance. Methodology and results: Some linear (anogenital distance) and weight measurements were taken on 390 anesthetized grasscutters (202 males and 188 females) aged from two weeks to 12 months. The results led to eight linear prediction equation models of grasscutter age from anogenital distance and body weight. The best determined grasscutter age with an elevated coefficient value was: Age = - 5.50 + 0.37 x DAG + 0.01 x WT with R2 = 0.98. The Equation determining grasscutter age with a weak determination coefficients value was: Age = -18.22 +1.26 x DAG with R2 = 0.88. These models of equations can be used by literate breeders or researchers and in semi-intensive and intensive raisings. Conclusions and application of findings: These results are useful to predict not recorded age of raised grasscutter, estimate game grasscutter age, make better management of reproduction and a good sanitary follow-up, and improvement of farming conditions, compare wild and raised grasscutter meat since meat organoleptic quality generally varies according to age. Key words: Benin, vulva, testes, brown coloration, age, model

Adolescent development of psychosis as an outcome of hearing impairment: a 10-year longitudinal study

Background It has long been acknowledged that hearing impairment may increase the risk for psychotic experiences. Recent work suggests that young people in particular may be at risk, indicating a possible developmental mechanism. Method The hypothesis that individuals exposed to hearing impairment in early adolescence would display the highest risk for psychotic symptoms was examined in a prospective cohort study of a population sample of originally 3021 adolescents and young adults aged 14-24 years at baseline, in Munich, Germany (Early Developmental Stages of Psychopathology Study). The expression of psychosis was assessed at multiple time points over a period of up to 10 years, using a diagnostic interview (Munich Composite International Diagnostic Interview; CIDI) administered by clinical psychologists. Results Hearing impairment was associated with CIDI psychotic symptoms [odds ratio (OR) 2.04, 95% confidence interval (CI) 1.10-3.81], particularly more severe psychotic symptoms (OR 5.66, 95% CI 1.64-19.49). The association between hearing impairment and CIDI psychotic symptoms was much stronger in the youngest group aged 14-17 years at baseline (OR 3.28, 95% CI 1.54-7.01) than in the older group aged 18-24 years at baseline (OR 0.82, 95% CI 0.24-2.84). Conclusions The finding of an age-specific association between hearing impairment and psychotic experiences suggests that disruption of development at a critical adolescent phase, in interaction with other personal and social vulnerabilities, may increase the risk for psychotic symptom

Evidence that bipolar disorder is the poor outcome fraction of a common developmental phenotype: an 8-year cohort study in young people

Background Reported rates of bipolar syndromes are highly variable between studies because of age differences, differences in diagnostic criteria, or restriction of sampling to clinical contacts. Method In 1395 adolescents aged 14-17 years, DSM-IV (hypo)manic episodes (manic and hypomanic episodes combined), use of mental health care, and five ordinal subcategories representing the underlying continuous score of (hypo)manic symptoms (‘mania symptom scale') were measured at baseline and approximately 1.5, 4 and 10 years later using the Munich-Composite International Diagnostic Interview (DIA-X/M-CIDI). Results Incidence rates (IRs) of both (hypo)manic episodes and (hypo)manic symptoms (at least one DSM-IV core symptom) were far higher (714/105 person-years and 1720/105 person-years respectively) than traditional estimates. In addition, the risk of developing (hypo)manic episodes was very low after the age of 21 years [hazard ratio (HR) 0.031, 95% confidence interval (CI) 0.0050-0.19], independent of childhood disorders such as attention deficit hyperactivity disorder (ADHD). Most individuals with hypomanic and manic episodes were never in care (87% and 62% respectively) and not presenting co-morbid depressive episodes (69% and 60% respectively). The probability of mental health care increased linearly with the number of symptoms on the mania symptom scale. The incidence of the bipolar categories, in particular at the level of clinical morbidity, was strongly associated with previous childhood disorders and male sex. Conclusions This study showed, for the first time, that experiencing (hypo)manic symptoms is a common adolescent phenomenon that infrequently predicts mental health care use. The findings suggest that the onset of bipolar disorder can be elucidated by studying the pathway from non-pathological behavioural expression to dysfunction and need for car

Critical Infrastructures You Can Trust: Where Telecommunications Fits

This paper discusses two NISs: the public telephone network (PTN) and the Internet. Being themselves large and complex NISs, they not only merit study in their own right but can help us to understand some of the technical problems faced by the developers and operators of other NISs. In addition, the high cost of building a global communications infrastructure from the ground up implies that one or both of these two networks is likely to furnish communications services for most other NISs. Therefore, an understanding of the vulnerabilties of the PTN and Internet informs the assessment of the trustworthiness of other NISs. Ideas for improving the trustworthiness of the PTN and Internet are also proposed, both for the short-term (by improved use of existing technologies and procedures) and for the long-term (by identifying some areas where the state-of-the-art is inadequate and research is therefore needed). Finally, some observations are offered about Internet telephony and the use of the Internet for critical infrastructures

Gewasbescherming in goede aarde : Terugblik op de KNPV-najaarsbijeenkomst, 8 december 2010, Wageningen

De KNPV-najaarsbijeenkomst op 8 december, had dit jaar als onderwerp ‘De Bodem’. Het programma is samengesteld in samenwerking met de Werkgroep Bodempathogenen en bodemmicrobiologie. De dag was tevens ook de najaarbijeenkomst van deze KNPV-werkgroep. Een recordaantal van 125 deelnemers, enthousiast publiek, gezelligheid, netwerken, een afwisselend programma, en inspirerende sprekers, maakten de dag tot een overdonderend succes