The development of ophthalmacrosis in the domestic chicken

A series of 12 experiments was conducted to study factors involved in the development of ophthalmacrosis in chickens. It was found that exposure of chicks to continuous light, regardless of color or intensity, caused the eyeballs to enlarge, but more strikingly that continuous darkness caused the enlargement to an even greater extent. Breaking the day into long, short, or superimposed photoperiods resulted in less apparent eye enlargement than was found in birds exposed to a continuous lighting regime. When the birds were exposed to a diurnal light cycle the eyes appeared to be unaffected. Chicks hatched from eggs incubated in continuous darkness appeared to have ophthalmacrosis at hatching time; however, when the chicks were subsequently placed under a diurnal light cycle they returned to normal. When these chicks were placed under a continuous lighting regime upon hatching the condition continued to worsen and permanently impaired vision resulted. Regardless of whether the birds were placed under a continuous lighting regime from 0-8 weeks or from 6-22 weeks of age they developed ophthalmacrosis; however, the symptoms appeared more slowly in the 8-22 week period. When birds with ophthal macrosis were switched to a diurnal light cycle from 8-22 weeks all returned to normal but with varying degrees of retinal damage. Switching birds with normal eyes to a continuous lighting regime from 8-22 weeks of age resulted in varying degrees of ophthal macrosis and retinal damage. In all cases the degree of retinal damage was positively related to the degree of ophthalmaorosis. The development of ophthalmaorosis was found to be related to the accumulation of excess amounts of sodium and water in the eye. The effects of pinealectomy, estrogen implantation, and the feeding of thiouracil and protamone on the development of ophthalmaorosis were studied. The relationships of pituitary, bursa, and thyroid weights to ophthalmaorosis were determined, A hypothesis, involving the hypothalmic-pituitary-adrenal complex, to explain the development of ophthalmaorosis is presented

Assessing students’ epistemic beliefs related to professional and school science

The school context, like other influences, affects the development of students’ epistemic beliefs (EBs), with theoretical conceptualizations suggesting a distinction between EBs related to professional and school science. However, empirical studies rarely address this distinction, and instruments separately assessing these EBs are not available. We address this research gap by providing a new questionnaire that is based on the established instrument by Conley et al. (2004) and which uses pairs of analogous items referring to the contexts of professional and school science. We succeeded in simultaneously assessing students’ EBs with reliable scales that allow for direct comparisons. Cross-sectional data is reported from a cohort study (N = 405) in grades 6 (n = 132), 8 (n = 167) and 10 (n = 106) that showed higher agreement with the scales related to professional science as well as higher agreement in higher grade levels. We further discuss methodological aspects of scale-formation, and highlight promising implementations of our questionnaire that future research could benefit from

Edge states in a two-dimensional honeycomb lattice of massive magnetic skyrmions

We study the collective dynamics of a two-dimensional honeycomb lattice of magnetic skyrmions. By performing large-scale micromagnetic simulations, we find multiple chiral and non-chiral edge modes of skyrmion oscillations in the lattice. The non-chiral edge states are due to the Tamm-Shockley mechanism, while the chiral ones are topologically protected against structure defects and hold different handednesses depending on the mode frequency. To interpret the emerging multiband nature of the chiral edge states, we generalize the massless Thiele's equation by including a second-order inertial term of skyrmion mass as well as a third-order non-Newtonian gyroscopic term, which allows us to model the band structure of skrymion oscillations. Theoretical results compare well with numerical simulations. Our findings uncover the importance of high order effects in strongly coupled skyrmions and are helpful for designing novel topological devices.Comment: 6 pages,4 figures,accepted by Physical Review B as a Rapid Communicatio

International collaborative follow - up investigation of graduating high school students’ understandings of the nature of scientific inquiry: is progress Being made?

Understandings of the nature of scientific inquiry (NOSI), as opposed to engaging students in inquiry learning experiences, are included in science education reform documents around the world. However, little is known about what students have learned about NOSI during their pre-college school years. The purpose of this large-scale follow-up international project (i.e. 32 countries and regions, spanning six continents and including 3917 students for the high school sample) was to collect data on what exiting high school students have learned about NOSI. Additionally, the study investigated changes in 12th grade students’ NOSI understandings compared to seventh grade (i.e. 20 countries and regions) students’ understandings from a prior investigation [Lederman et al. (2019). An international collaborative investigation of beginning seventh grade students’ understandings of scientific inquiry: Establishing a baseline. Journal of Research in Science Teaching, 56(4), 486–515. https://doi.org/10.1002/tea.21512]. This study documents and discusses graduating high school students’ understandings and compares their understandings to seventh grade students’ understandings of the same aspects of scientific inquiry for each country. It is important to note that collecting data from each of the 130+ countries globally was not feasible. Similarly, it was not possible to collect data from every region of each country. A concerted effort was made, however, to provide a relatively representative picture of each country and the world

Herausforderungen und Potenziale interdisziplinärer Forschung

Auf der Tagung der Fachsektion Didaktik der Biologie (FDdB) im VBio 2017 in Halle (Saale) wurden im Rahmen eines World Cafés zwei Tische zum Thema „Herausforderungen und Potenziale interdisziplinärer Forschung” angeboten. Hier diskutierten Professoren, Doktoranden und Lehrer der Biologiedidaktik und des Biologieunterrichts über die aktuelle Thematik. Der Artikel soll unter den Aspekten „Forschungskooperationen“, „Nutzung von Methoden“ und „Themenschwerpunkte“ Hürden und Chancen für die Weiterentwicklung disziplinübergreifender Forschung berichten, die im Rahmen der Diskussion aufgeworfen wurden. Zusätzlich sollen ausgewählte Aspekte nochmals ausgeführt werden, um den im World Café geäußerten Bedarfen zu begegnen und diese theoretisch einzuordnen. (Autor)At the conference for Biology Education of FDdB 2017 in Halle (Saale), Germany, the topic “Challenges and potentials of interdisciplinary research” was discussed at two tables during the world café session. With regard to the aspects “research-cooperations”, “use of methods” and “central topics” the article summarizes the discussions with respect to barriers and opportunities for the enhancement of interdisciplinary research. Furthermore, aspects in need for further clarification are addressed and elaborated in more detail. (DIPF/Orig.