14 research outputs found
Een leiders-volgersmodel voor online sociale netwerken, gebaseerd op een SIR-model voor het Zikavirus
No full textOnline sociale netwerken zijn zeer populair tegenwoordig. Het gebruik en de invloed van debedrijven achter deze netwerken hebben veel invloed op de maatschappij en hun macht is ver-strekkend. Niet alleen op het voor de hand liggende sociale aspect, maar ook op het gebiedvan privacy en de economie. Het zijn immers zeer grote bedrijven waar zeer veel geld in omgaat en daarmee zijn de belangen enorm. Het gebruik modelleren van online sociale netwerkenis dus interessant voor zowel bedrijven als ook individuen. In dit verslag worden verschillendevormen van SIR-model bekeken, alsmede uitbreidingen. Ook wordt een implementatie gege-ven van een model voor het verloop van het Zikavirus. Hierbij worden de invloeden van tweeverschillende populaties op elkaar en de effecten daarvan gemodelleerd. Het concept van tweeverschillende groepen die effect op elkaar hebben wordt ook gebruikt om de populatie in tweegroepen te verdelen bij het modelleren van het gebruik van online sociale netwerken. Er wordt onderscheid gemaakt tussen leiders en volgers, ook wel ‘early adaptors’ en ‘followers’ genoemd. Ook wordt er rekening gehouden met het effect van leiders op volgers bij dit model. Het mo-del wordt vergeleken met een bekende uitbreiding op het SIR-model, het irSIRSbd-model. Hetzo genoemde leiders-volgersmodel presteert beter dan het SIR-model, en vergelijkbaar met hetirSIRSbd-model, terwijl er geen vergelijkbare uitbreidingen aan zijn toegevoegd. De parameters voor de modellen zijn geoptimaliseerd in Matlab metfminsearchde kleinst mogelijke sum of squared errors te geven ten op zichte van de bekende zoekdata
Nurturing religious citizens for the public sphere: an examination of the public regulation of religious schools in Taiwan
No full textThis thesis examines Taiwan's regulatory scheme with regard to religious schooling by considering the role of religious citizens in the public sphere of a liberal democratic society. Inspired by the writings of Daniel Conkle on the concept of religious reconcilers, the author argues that the goal of public regulation of religious schooling should be oriented toward producing religious reconcilers, whose political participation benefits society as a whole. The goal of producing religious reconcilers supplies the state with positive reasons to encourage religious schools to commit themselves to cultivating a solid religious worldview in their students. On the other hand, that goal warrants the state to deploy proper regulatory measures to ensure that religious schools encourage their students to engage with people who have different religious or moral convictions. The author conducts a case study on Quebec's "Ethic and Religious Culture" program in order to know whether imposing such a civic program on religious schools constitutes a reasonable constraint on the schools in view of the goal of producing religious reconcilers. Finally, the author applies the concept of religious reconcilers as well as its educational implications to analyze the recent controversies surrounding the public regulation of religious schools in Taiwan. The author advocates that religious schools in Taiwan should be given more room to pursue their separate educational goals, on the condition that they cultivate a positive attitude toward engaging with others at the same time.Cette thèse examine le régime de réglementation Taiwan en considérant le rôle des citoyens religieux dans la sphère publique d'une société démocratique libérale. Inspiré par les écrits de Daniel Conkle sur le concept de réconciliateurs religieux, l'auteur fait valoir que l'objectif de la régulation publique de l'enseignement religieux doit être orienté vers la production réconciliateurs religieuses, dont la participation politique profite à la société dans son ensemble. Le objectif de produire des réconciliateurs religieuses fournit l'état de raisons positives pour encourager les écoles religieuses à s'engager à cultiver une vision religieuse du monde solide chez leurs élèves. D'autre part, cet objectif justifie l'état de déployer des mesures réglementaires appropriées pour assurer que les écoles religieuses encouragent leurs étudiants à s'engager avec des gens qui ont des convictions religieuses différentes ou morales. L'auteur procède à une étude de cas «Ethique et culture religieuse» du programme de Québec afin de savoir si l'imposition d'un tel programme civique sur les écoles religieuses constitue une contrainte raisonnable sur les écoles en vue de l'objectif de produire des réconciliateurs religieuses. Enfin, l'auteur applique le concept de réconciliateurs religieuses ainsi que ses implications pédagogiques d'analyser les récentes controverses entourant la réglementation public des écoles religieuses à Taiwan. L'auteur préconise que les écoles religieuses à Taiwan devraient avoir plus d'espace pour poursuivre leurs objectifs éducatifs distincts, à la condition qu'ils cultivent une attitude positive envers engager avec les autres en même temps
Sperm numbers in drone honeybees (Apis mellifera) depend on body size
Get PDFThe effect of drone honeybee's body size on semen production was evaluated. In the same colonies, drones were either reared in drone cells (large drones) or in worker cells (small drones). Wing lengths (size indicator) and sperm numbers of small and large drones were compared. Small drones (~13% reduced wing size) produce significantly fewer spermatozoa (7.5 0.5 million) than normally sized drones (11.9 1.0 million spermatozoa). There is a significant positive correlation between sperm number and wing size within the small drones and in both groups combined. In the large group alone no correlation was found. The rearing investment per spermatozoon is lower for small than for normally sized drones because small drones produce more spermatozoa in relation to their body weight. Since colonies usually produce large drones, the enhanced investment must be outweighed by a mating advantage of large drones
Testing reliability of a potential island mating apiary using DNA microsatellites
No full textInternational audienc
Testing reliability of a potential island mating apiary using DNA microsatellites
No full textTwenty-four virgin sister queens were kept for 21 days in mating nuclei on the drone-free island Baltrum to test the reliability of a potential mating area. On each of the neighbouring islands Nordemey and Langeoog (750 m and 2 km away) 12 sister queens were kept with drones. Workers from colonies with island-mated queens (Baltrum n = 11, Langeoog n = 7 and Nordemey n = 6) were genotyped with four DNA microsatellite loci (n = 996) to estimate queen mating frequency. No differences in queen mating frequency were observed between Langeoog and Nordemey. However, the level of polyandry on Baltrum was significantly lower than on the neighbouring islands, indicating that mating conditions were much more difficult. The standard genetic distance and differences in allele frequencies between the populations were determined to estimate putative origins of the drones. In this study, 43.7 % of the identified drone fathers did not descend from any of the queens on the adjacent islands. They were most likely from mainland colonies at least 5.4 km (3 km across open water) away, showing that the combination of distances over open water and over dry land is important in explaining the mating behaviour of honeybee queens. © Inra/DIB/AGIB/Elsevier, Pari
Validity of the new lifestyles NL-1000 accelerometer for measuring time spent in moderate-to-vigorous physical activity in school settings
Get PDFCurrent interest in promoting physical activity in the school environment necessitates an inexpensive, accurate method of measuring physical activity in such settings. Additionally, it is recognized that physical activity must be of at least moderate intensity in order to yield substantial health benefits. The purpose of the study, therefore, was to determine the validity of the New Lifestyles NL-1000 (New Lifestyles, Inc., Lee's Summit, Missouri, USA) accelerometer for measuring moderate-to-vigorous physical activity in school settings, using the Actigraph GT1M (ActiGraph, Pensacola, Florida, USA) as the criterion. Data were collected during a cross-country run (n = 12), physical education (n = 18), and classroom-based physical activities (n = 42). Significant and meaningful intraclass correlations between methods were found, and NL-1000 estimates of moderate-to-vigorous physical activity were not meaningfully different from GT1M-estimated moderate- to-vigorous physical activity. The NL-1000 therefore shows promising validity evidence as an inexpensive, convenient method of measuring moderate-to-vigorous physical activity in school settings
Empiric Antimicrobial Treatment of Anastomotic Leakage after Esophageal Resection:The Most Commonly Used Antimicrobial Regimens in the Netherlands and an Antimicrobial Treatment Recommendation Based on a Single-Center Population
Get PDFIntroduction: The development of anastomotic leakage (AL) after esophagectomy is a severe complication, often leading to mediastinitis and systemic infections. Effective empiric antimicrobial therapy is crucial, but there is no consensus on the optimal regimen. This study aimed to document antimicrobial regimens used in the Netherlands and to evaluate culture results from AL after esophagectomy at our center. Methods: An online questionnaire about the preferred antimicrobial treatment of AL after esophagectomy was sent to all upper gastrointestinal surgeons in the Netherlands. In addition, drain culture results from patients with AL after esophagectomy in our center were retrospectively analyzed. Results: From 76 responses, 28 were included, representing 13 of the 15 esophagectomy-performing centers in the Netherlands. For treating AL after esophagectomy, respondents typically choose broad-spectrum regimens covering Gram-negative, Gram-positive, and anaerobic bacteria. The cultures of 57 patients were analyzed. Overall, 61% had positive cultures for yeast, 61% of patients for Enterobacterales, and 16% for Pseudomonas and other non-fermenters. Conclusion: Based on the studied cultures, empiric antibiotics should cover Gram-positive, Gram-negative, anaerobe bacteria and Pseudomonas. We recommend the use of empiric amoxicillin/clavulanic acid with tobramycin for patients with AL after esophagectomy, which is now protocol in our center. The addition of antifungals remains debatable. Given the high incidence of yeast-positive cultures in the studied cohort, we recommend the addition of an echinocandin in clinically unstable patients. 2025 The Author(s).</p
Infestation levels of Apis mellifera scutellata swarms by socially parasitic Cape honeybee workers (Apis mellifera capensis)
No full textInternational audienc
Infestation levels of Apis mellifera scutellata swarms by socially parasitic Cape honeybee workers (Apis mellifera capensis)
No full textA single clonal lineage of socially parasitic Cape honeybee workers, Apis mellifera capensis, has caused dramatic losses in managed populations of A. m. scutellata, raising concerns that wild populations might also be affected. We surveyed A. m. scutellata swarms at 27 localities in beekeeping areas (N = 87) and in nature reserves (N = 79). While eleven swarms were infested in beekeeping areas, we found no infestations in nature reserves. Eight swarms had no symptoms except workers with black tergites. However, DNA data revealed that these workers are not parasitic, showing that diagnoses based on tergite colour alone yield false positive results. Nevertheless, it is practical because we had no false negative diagnoses either. Nature reserves may be important refuges to protect wild A. m. scutellata populations against imported honeybees
Conclusions of the Worldwide Integrated Assessment on the risks of neonicotinoids and fipronil to biodiversity and ecosystem functioning
Get PDFThe side effects of the current global use of pesticides on wildlife, particularly at higher levels of biological organization: populations, communities and ecosystems, are poorly understood (Köhler and Triebskorn 2013). Here, we focus on one of the problematic groups of agrochemicals, the systemic insecticides fipronil and those of the neonicotinoid family. The increasing global reliance on the partly prophylactic use of these persistent and potent neurotoxic systemic insecticides has raised concerns about their impacts on biodiversity, ecosystem functioning and ecosystem services provided by a wide range of affected species and environments. The present scale of use, combined with the properties of these compounds, has resulted in widespread contamination of agricultural soils, freshwater resources, wetlands, non-target vegetation and estuarine and coastal marine systems, which means that many organisms inhabiting these habitats are being repeatedly and chronically expose ..
