On totally geodesic submanifolds in the Jacobian locus

We study submanifolds of A_g that are totally geodesic for the locally symmetric metric and which are contained in the closure of the Jacobian locus but not in its boundary. In the first section we recall a formula for the second fundamental form of the period map due to Pirola, Tortora and the first author. We show that this result can be stated quite neatly using a line bundle over the product of the curve with itself. We give an upper bound for the dimension of a germ of a totally geodesic submanifold passing through [C] in M_g in terms of the gonality of C. This yields an upper bound for the dimension of a germ of a totally geodesic submanifold contained in the Jacobian locus, which only depends on the genus. We also study the submanifolds of A_g obtained from cyclic covers of the projective line. These have been studied by various authors. Moonen determined which of them are Shimura varieties using deep results in positive characteristic. Using our methods we show that many of the submanifolds which are not Shimura varieties are not even totally geodesic.Comment: To appear on International Journal of Mathematic

The tool switching problem revisited.

In this note we study the complexity of the tool switching problem with non-uniform tool sizes. More speci cally, we consider the problem where the job sequence is given as part of the input. We show that the resulting tooling problem is strongly NP-complete, even in case of unit loading and unloading costs. However, we show that if the capacity of the tool magazine is also given as part of the input, the problem is solvable in polynomial time.Research; Studies; Complexity; Job; Costs; Time;

On some differential-geometric aspects of the Torelli map

In this note we survey recent results on the extrinsic geometry of the Jacobian locus inside $\mathsf{A}_g$. We describe the second fundamental form of the Torelli map as a multiplication map, recall the relation between totally geodesic subvarieties and Hodge loci and survey various results related to totally geodesic subvarieties and the Jacobian locus.Comment: To appear on Boll. UMI, special volume in memory of Paolo de Bartolomei

Resilience in the face of adversity in adults with an intellectual disability:A literature review

Background: Persons with an intellectual disability are at a higher risk of experiencing adversities. The concept of resilience offers promising insights into facilitating personal growth after adversity. The current study aims at providing an overview of the current research on resilience and the way this can contribute to quality of life in people with intellectual disability.  Method: A literature review was conducted in the databases PsycINFO and Web of Science. To evaluate the quality of the studies, the Mixed Method Appraisal Tool (MMAT) was used.  Results: The themes, autonomy, self-acceptance and physical health, were identified as internal sources of resilience. External sources of resilience can be found within the social network and daily activities.  Conclusion: The current overview shows promising results to address resilience in adults with intellectual disability. More research is needed to identify the full range of resiliency factors

Assessing the quality of support and discovering sources of resilience during COVID-19 measures in people with intellectual disabilities by professional carers

BACKGROUND: During COVID-19 measures face-to-face contact is limited and professional carers have to find other ways to support people with intellectual disabilities. COVID-19 measures can increase stress in people with intellectual disabilities, although some people may adapt to or grow from these uncertain situations. Resilience is the process of effectively negotiating, adapting to, or managing significant sources of stress and trauma. The current study aims to provide professional carers with new insights into how they can support people with intellectual disabilities. METHOD: An online survey was shared through the social media and organizational newsletters of MEE ZHN (a non-governmental organization for people with disabilities). The resilience framework by Ungar (2019) was adapted to fit to people with intellectual disabilities during COVID-19 measures. Statistical analyses were performed in SPSS statistics version 26. RESULTS: Results show that professional carers applied diverse and distal methods to maintain contact with people with intellectual disabilities during the COVID-19 measures. Professional carers reported a significant decrease in the quality of contact with clients with intellectual disabilities, but overall high levels of resilience in the same clients. IMPLICATIONS: Online methods of communication are possibly insufficient for professionals to cover all needs of people with intellectual disabilities. During this pandemic professionals should be aware of stress but also of resilience in people with intellectual disabilities