Eye tracking as feedback tool in physics teacher education

The ability to direct pupils’ attention to relevant information during the experimental process is relevant for all science teachers. The aim of this article is to investigate the effects of training the ability of prospective physics teachers to direct attention during the presentation of experiments with eye tracking visualizations of pupils’ visual attention as a feedback tool. Many eye tracking studies in the field of learning use eye movement recordings to investigate the effectiveness of an instructional design by varying cues or the presentation format. Another important line of research relates to study the teacher’s gaze in a real classroom setting (mobile eye tracking). Here we use eye tracking in a new and innovative way: Eye tracking is used as a feedback tool for prospective teachers, showing them the effects of their verbal moderations when trying to direct their pupils’ attention. The study is based on a mixed methods approach and is designed as a single factor quasi-experiment with pre-post measurement. Pre- and post-test are identical. Prospective teachers record their verbal moderations on a “silent” experimental video. The quality of the moderation is rated by several independent physics educators. In addition, pupils’ eye movements while watching the videos are recorded using eye tracking. The resulting eye movements are used by the lecturer to give individual feedback to the prospective teachers, focusing on the ability to control attention in class. The effect of this eye tracking feedback on the prospective teachers is recorded in interviews. Between the pre-test and the post-test, the results show a significant improvement in the quality of the moderations of the videos. The results of the interviews show that the reason for this improvement is the perception of one’s own impact on the pupils’ attention through eye tracking feedback. The overall training program of moderating “silent videos” including eye tracking as a feedback tool allows for targeted training of the verbal guidance of the pupils’ attention during the presentation of experiments

Two enzymes catalyze vitamin K 2,3-epoxide reductase activity in mouse: VKORC1 is highly expressed in exocrine tissues while VKORC1L1 is highly expressed in brain

AbstractVKORC1 and VKORC1L1 are enzymes that both catalyze the reduction of vitamin K2,3-epoxide via vitamin K quinone to vitamin K hydroquinone. VKORC1 is the key enzyme of the classical vitamin K cycle by which vitamin K-dependent (VKD) proteins are γ-carboxylated by the hepatic γ-glutamyl carboxylase (GGCX). In contrast, the VKORC1 paralog enzyme, VKORC1L1, is chiefly responsible for antioxidative function by reduction of vitamin K to prevent damage by intracellular reactive oxygen species. To investigate tissue-specific vitamin K 2,3-epoxide reductase (VKOR) function of both enzymes, we quantified mRNA levels for VKORC1, VKORC1L1, GGCX, and NQO1 and measured VKOR enzymatic activities in 29 different mouse tissues. VKORC1 and GGCX are highly expressed in liver, lung and exocrine tissues including mammary gland, salivary gland and prostate suggesting important extrahepatic roles for the vitamin K cycle. Interestingly, VKORC1L1 showed highest transcription levels in brain. Due to the absence of detectable NQO1 transcription in liver, we assume this enzyme has no bypass function with respect to activation of VKD coagulation proteins. Our data strongly suggest diverse functions for the vitamin K cycle in extrahepatic biological pathways

Methylation at Global LINE-1 Repeats in Human Blood Are Affected by Gender but Not by Age or Natural Hormone Cycles

Previously, we reported on inter-individual and gender specific variations of LINE-1 methylation in healthy individuals. In this study, we investigated whether this variability could be influenced by age or sex hormones in humans. To this end, we studied LINE-1 methylation in vivo in blood-derived DNA from individuals aged 18 to 64 years and from young healthy females at various hormone levels during the menstrual cycle. Our results show that no significant association with age was observed. However, the previously reported increase of LINE-1 methylation in males was reconfirmed. In females, although no correlation between LINE-1 or Alu methylation and hormone levels was observed, a significant stable individual specific level of methylation was noted. In vitro results largely confirmed these findings, as neither estrogen nor dihydrotestosterone affected LINE-1 or Alu methylation in Hek293T, HUVEC, or MDA-kb2 cell lines. In contrast, a decrease in methylation was observed in estrogen-treated T47-Kbluc cell lines strongly expressing estrogen receptor. The very low expression of estrogen receptor in blood cells could explain the observed insensitivity of methylation at LINE-1 to natural hormonal variations in females. In conclusion, neither natural cycle of hormones nor age has a detectable effect on the LINE-1 methylation in peripheral blood cells, while gender remains an important factor

Teures Window Dressing. Akkreditierung als Qualitätssicherung von Studiengängen?

Die Autoren kommen zu folgendem Fazit: Die erheblichen Kosten sind per se noch kein hinreichendes Argument, das deutsche Akkreditierungssystem abzulehnen. Sie wären eventuell gerechtfertigt, wenn die Akkreditierung zu deutlichen Qualitätsverbesserungen geführt hätte oder führen könnte. Hier aber liegen die fundamentalen Schwächen des Akkreditierungssystems. Auf einer übergeordneten, konzeptionellen Ebene der Hochschul-Qualitätsforschung zeigen die vorliegenden wissenschaftlichen Publikationen, wie problematisch die Definition von präzisen, hinreichend konsensfähigen Qualitätskriterien für Studiengänge ist. Diese wären aber Voraussetzung für ihre valide (Mindest-)Qualitätsevaluierung. (HoF/Text übernommen

Structural Modeling Insights into Human VKORC1 Phenotypes

Vitamin K 2,3-epoxide reductase complex subunit 1 (VKORC1) catalyses the reduction of vitamin K and its 2,3-epoxide essential to sustain γ-carboxylation of vitamin K-dependent proteins. Two different phenotypes are associated with mutations in human VKORC1. The majority of mutations cause resistance to 4-hydroxycoumarin- and indandione-based vitamin K antagonists (VKA) used in the prevention and therapy of thromboembolism. Patients with these mutations require greater doses of VKA for stable anticoagulation than patients without mutations. The second phenotype, a very rare autosomal-recessive bleeding disorder caused by combined deficiency of vitamin K dependent clotting factors type 2 (VKCFD2) arises from a homozygous Arg98Trp mutation. The bleeding phenotype can be corrected by vitamin K administration. Here, we summarize published experimental data and in silico modeling results in order to rationalize the mechanisms of VKA resistance and VKCFD2

VKORC1 and VKORC1L1: Why do Vertebrates Have Two Vitamin K 2,3-Epoxide Reductases?

Among all cellular life on earth, with the exception of yeasts, fungi, and some prokaryotes, VKOR family homologs are ubiquitously encoded in nuclear genomes, suggesting ancient and important biological roles for these enzymes. Despite single gene and whole genome duplications on the largest evolutionary timescales, and the fact that most gene duplications eventually result in loss of one copy, it is surprising that all jawed vertebrates (gnathostomes) have retained two paralogous VKOR genes. Both VKOR paralogs function as entry points for nutritionally acquired and recycled K vitamers in the vitamin K cycle. Here we present phylogenetic evidence that the human paralogs likely arose earlier than gnathostomes, possibly in the ancestor of crown chordates. We ask why gnathostomes have maintained these paralogs throughout evolution and present a current summary of what we know. In particular, we look to published studies about tissue- and developmental stage-specific expression, enzymatic function, phylogeny, biological roles and associated pathways that together suggest subfunctionalization as a major influence in evolutionary fixation of both paralogs. Additionally, we investigate on what evolutionary timescale the paralogs arose and under what circumstances in order to gain insight into the biological raison d’être for both VKOR paralogs in gnathostomes