Signature of a three-dimensional photonic band gap observed on silicon inverse woodpile photonic crystals

We have studied the reflectivity of CMOS-compatible three-dimensional silicon inverse woodpile photonic crystals at near-infrared frequencies. Polarization-resolved reflectivity spectra were obtained from two orthogonal crystal surfaces corresponding to 1.88 pi sr solid angle. The spectra reveal broad peaks with high reflectivity up to 67 % that are independent of the spatial position on the crystals. The spectrally overlapping reflectivity peaks for all directions and polarizations form the signature of a broad photonic band gap with a relative bandwidth up to 16 %. This signature is supported with stopgaps in plane wave bandstructure calculations and with the frequency region of the expected band gap.Comment: 9 pages, 5 figure

Assaults on belonging : how Dutch youth without ‘blue eyes, cheese, and clogs’ experience everyday racism in educational contexts

Minoritized students’ ethnic backgrounds and racial appearances influence their academic opportunities and belonging experiences, and limit their access to safe and equal learning environments. In the Netherlands, limited research has focused on minoritized students’ experiences. In this study, we drew upon a theoretical framework focused on Othering and belonging as well as macro-/micro- connections related to racism to investigate the contemporary educational experiences of students from nondominant backgrounds. Participants experienced everyday racism and Othering in the: continuous centering of Whiteness and marginalization of the non-White Other; persistent obstacles perpetuated by educators that prevented parental participation; and consistent underestimation of students’ abilities by teachers and peers. As a step toward more just schooling, participants suggest that educators become more aware of minoritized students’ backgrounds and create spaces of belonging

Problematic weed species in organic arable agriculture around the Baltic Sea - an expert database

Weeds are a perpetual challenge in Organic agriculture. However, they serve multiple ecosystem services and a low competitive weed cover can be tolerated. Adding to this, is the fact that only a few species prove problematic for both the crop and the farmer. The international PRODIVA project researches the effect of crop diversity strategies on the diversity of weed communities, hypothesizing that by increasing the weed diversity, the development of problematic weeds will mitigated. A preparatory study was conducted to list the most problematic weed species in spring sown cereals in the countries involved with PRODIVA. For this a literature review was conducted in all participating countries, collecting local sources including grey literature. This was combined with the opinion of local extension services and other weed experts. From this a list of 10 most problematic weeds was deducted for each country. We found both annual and perennial species to be mentioned as problematic. A majority of the more problematic species were shared between countries, such as Cirsium arvensis, Elitrigia repens and Chenopodium album. Still, all countries revealed to have individual weed challenges as well. These findings are published as a folder that will be available to local stakeholders

Online One-Stop Shop for Disaster Response Services After the MH17 Airplane Crash:An Evaluation Study

Background: A one-stop shop for disaster response services provides a central location for information and advice in an accessible way. Yet little is known about its organization and outcomes. After the MH17 airplane crash, the one-stop shop concept was realized through a digital environment called the Information and Referral Center (IRC). The aim of this study was to evaluate the experiences of users and providers in regard to the IRC and to identify improvement points for future IRCs. Method: Data was collected among affected ones as well as involved organizations, using interviews, focus groups, surveys and online user information. Existing evaluation and quality models were combined to design the study and analyze the data. Results: First, affected ones and a variety of organizations involved were positive about the merits of the IRC. Affected ones indicated they perceived the IRC as a reliable source of information and appreciated the referral possibilities. Second, the feature of the IRC to serve as a community where affected ones could meet, share experiences and support each other was hardly used according to participants. Lastly, tracking evolving psychosocial needs and problems through the IRC was hampered due to difficulty in accessing relevant data. Conclusions: The IRC helped organizations to structure and align their services. Affected ones were positive about its reliability and accessibility. An IRC has to be embedded within the established care structures. Future research could indicate whether an IRC is useful in other event types and population contexts as well

Combining Individual-Level Discrete Choice Experiment Estimates and Costs to Inform Health Care Management Decisions about Customized Care: The Case of Follow-Up Strategies after Breast Cancer Treatment

AbstractObjectiveCustomized care can be beneficial for patients when preferences for health care programs are heterogeneous. Yet, there is little guidance on how individual-specific preferences and cost data can be combined to inform health care decisions about customized care. Therefore, we propose a discrete choice experiment–based approach that illustrates how to analyze the cost-effectiveness of customized (and noncustomized) care programs to provide information for hospital managers.MethodsWe exploit the fact that choice models make it possible to determine whether preference heterogeneity exists and to obtain individual-specific parameter estimates. We present an approach of how to combine these individual-specific parameter estimates from a random parameter model (mixed logit model) with cost data to analyze the cost-effectiveness of customized care and demonstrate our method in the case of follow-up after breast cancer treatment.ResultsWe found that there is significant preference heterogeneity for all except two attributes of breast cancer treatment follow-up and that the fully customized care program leads to higher utility and lower costs than the current standardized program. Compared with the single alternative program, the fully customized care program has increased benefits and higher costs. Thus, it is necessary for health care decision makers to judge whether the use of resources for customized care is cost-effective.ConclusionsDecision makers should consider using the results obtained from our methodological approach when they consider implementing customized health care programs, because it may help to find ways to save costs and increase patient satisfaction

Carbon-grain sublimation: a new top-down component of protostellar chemistry

Earth's carbon deficit has been an outstanding problem in our understanding of the formation of our Solar System. A possible solution would be the sublimation of carbon grains at the so-called soot line (~300 K) early in the planet-formation process. Here, we argue that the most likely signatures of this process are an excess of hydrocarbons and nitriles inside the soot line, and a higher excitation temperature for these molecules compared to oxygen-bearing complex organics that desorb around the water snowline (~100 K). Such characteristics have been reported in the literature, for example, in Orion KL, although not uniformly, potentially due to differences in observational settings and analysis methods of different studies or related to the episodic nature of protostellar accretion. If this process is active, this would mean that there is a heretofore unknown component to the carbon chemistry during the protostellar phase that is acting from the top down - starting from the destruction of larger species - instead of from the bottom up from atoms. In the presence of such a top-down component, the origin of organic molecules needs to be re-explored.Comment: Accepted for publication in ApJL. 14 pages, 2 figures, 1 table (4 pages

Modular symbols and Hecke operators

We survey techniques to compute the action of the Hecke operators on the cohomology of arithmetic groups. These techniques can be seen as generalizations in different directions of the classical modular symbol algorithm, due to Manin and Ash-Rudolph. Most of the work is contained in papers of the author and the author with Mark McConnell. Some results are unpublished work of Mark McConnell and Robert MacPherson.Comment: 11 pp, 2 figures, uses psfrag.st