Jasmonic acid (JA) and its methyl ester (JA-Me) are able to introduce the accumulation of several specific polypeptides in cut leaf segments of barley. Two of the most prominent JA-induced proteins of M(r) 15,000 and 23,000 have been characterized by isolating and sequencing complete cDNA sequences. While the sequence of the M(r) 23,000 polypeptide shows no similarity to published sequences, the sequence of the M(r) 15,000 polypeptide corresponds to the higher-molecular-weight precursor of a leaf thionin previously characterized. Transcripts for the M(r) 23,000 and M(r) 15,000 polypeptides accumulate in leaf segments shortly after the beginning of JA treatment. JA and JA-Me induce the appearance of the two proteins not only in leaf segments but also in intact barley seedlings. However, in seedlings the accumulation of JA-induced proteins occurs much more slowly and requires high concentrations of volatile JA-Me. Thus, in barley it seems unlikely that volatile JA-Me is involved in the interaction between different members of this species, as has been proposed recently for tomato seedlings.

The frequency of possible "horizontal" gene transfer between a plant and a tightly associated bacterial pathogen was studied in a model system consisting of transgenic Solanum tuberosum, containing a beta-lactamase gene linked to a pBR322 origin of replication, and Erwinia chrysanthemi. This experimental system offers optimal conditions for the detection of possible horizontal gene transfer events, even when they occur at very low frequency. Horizontal gene transfer was not detected under conditions mimicking a "natural" infection. The gradual, stepwise alteration of artificial, positive control conditions to idealized natural conditions, however, allowed the characterization of factors that affected gene transfer, and revealed a gradual decrease of the gene transfer frequency from 6.3 x 10(-2) under optimal control conditions to a calculated 2.0 x 10(-17) under idealized natural conditions. These data, in combination with other published studies, argue that horizontal gene transfer is so rare as to be essentially irrelevant to any realistic assessment of the risk involved in release experiments involving transgenic plants.

Background: Inquiry-based science education (IBSE) is suitable to teach scientific contents as well as to foster scientific skills. Similar conclusions are drawn by studies with respect to scientific literacy, motivational aspects, vocabulary knowledge, conceptual understandings, critical thinking, and attitudes toward science. Nevertheless, IBSE is rarely adopted in schools. Often barriers for teachers account for this lack, with the result that even good teachers struggle to teach science as inquiry. More importantly, studies indicate that several barriers and constraints could be ascribed to problems teacher students have at the university stage. Purpose: The purpose of this explorative investigation is to examine the problems teacher students have when teaching science through inquiry. In order to draw a holistic picture of these problems, we identified problems from three different points of view leading to the research question: What problems regarding IBSE do teacher students have from an objective, a subjective, and a self-reflective perspective? Design & method: Using video analysis and observation tools as well as qualitative content analysis and open questionnaires we identified problems from each perspective. Results: The objectively stated problems comprise the lack of essential features of IBSE especially concerning 'Supporting pupils' own investigations' and 'Guiding analysis and conclusions.' The subjectively perceived problems comprise concerns about 'Teachers' abilities' and 'Pupils' abilities,' 'Differentiated instruction' and institutional frame 'Conditions' while the self-reflectively noticed problems mainly comprise concerns about 'Allowing inquiry,' 'Instructional Aspects,' and 'Pupils' behavior.' Conclusions: Each of the three different perspectives provides plenty of problems, partially overlapping, partially complementing one another, and partially revealing completely new problems. Consequently, teacher educators have to consider these three perspectives.

Promoting preservice science teachers' experimentation competency is required to provide a basis for meaningful learning through experiments in schools. However, preservice teachers show difficulties when experimenting. Previous research revealed that cognitive scaffolding promotes experimentation competency by structuring the learning process, while metacognitive and multimedia support enhance reflection. However, these support measures have not yet been tested in combination. Therefore, we decided to use cognitive scaffolding to support students' experimental achievements and supplement it by metacognitive and multimedia scaffolds in the experimental groups. Our research question is to what extent supplementing cognitive support by metacognitive and multimedia scaffolding further promotes experimentation competency. The intervention has been applied in a two-factorial design to a two-month experimental course for 63 biology teacher students in their first bachelor year.Pre-post-test measured experimentation competency in a performance assessment. Preservice teachers worked in groups of four. Therefore, measurement took place at group level (N = 16). Independent observers rated preservice teachers' group performance qualitatively on a theory-based system of categories. Afterwards, experimentation competency levels led to quantitative frequency analysis. The results reveal differing gains in experimentation competency but contrary to our hypotheses. Implications of combining scaffolding measures on promoting experimentation competency are discussed.

The Conceptual Model Map (CMM) presented here is intended to show the connections between different theories and constructs in the field of health and nutrition behavior (including literacy models, the knowledge–attitude(s)–practice(s) survey structure (KAP), behavior change theories, and Maslow’s pyramid of needs). The CMM can be used as a map to locate existing and future studies, to show their range of effect as well as their limitations. In this context, the CMM also reveals reasons for the attitude/intention–behavior gap.

No abstract

BACKGROUND: Food literacy, a sub-area of health literacy, is achieving attention in schools, academia, research, health care, businesses, and governments worldwide. Against the current COVID-19 pandemic backdrop, the relevance of food literacy's interconnected attributes such as nutritional knowledge, food skills, and food environment is gaining traction. Enhancing health and food literacy in the K-12 school environment are important empowerment tools with the potential to reduce health inequalities as vulnerable people are at risk of limited health literacy. METHODS:We aim to clarify the meaning of food literacy and its relationship to health literacy and other factors influencing eating behavior. RESULTS:We offer a proposed conceptual model depicting connections between relevant theories and constructs in the field of health and nutrition. Concrete actions are offered that contemporary schools can take guided by the utility of the model. CONCLUSIONS:This visual can help guide schools' multidimensional health and food literacy efforts while considering the realities of the current COVID-19 pandemic context and beyond. This model will provide an overarching reference for schools to consider key constructs to support practice, research, policy, and intervention efforts to advance their health and food literacy agendas.

At the beginning of the COVID-19 pandemic in spring 2020, school and university learning were abruptly switched to distance learning, coming along with psychological strains and various learning lags on the part of the students. These problems come to a head when focusing on university teacher students, since an expectable competence lag on their part, similarly arising from pandemic-caused distance learning in university teacher training, could affect their future teaching in schools, possibly then disadvantaging school students a second time. To determine changes of teacher students’ self-concept of professional knowledge, we used data of a repeated cross-sectional survey carried out in a period from 2018 to 2021, including several comparable cohorts of overall N = 395 teacher students. This design allowed for splitting the participants in two groups relating to times before and after switching to distance learning. Our results show that the switch to distance learning goes hand in hand with lower scores on almost every dimension of teacher students’ self-concept of professional knowledge, although, in parallel, their scores on variables such as openness to experiences, agreeableness, and conscientiousness increased significantly, indicating a certain degree of compliance with the new situation. Beyond that, we report on an evaluative survey among N = 84 teacher students carried out in July 2020, offering further insights into their situation during the first semester of distance learning. Its results primarily show which specific aspects of distance learning the students consider in need of improvement. On the other hand, it becomes clear that they experienced handicaps in various areas, accompanied by a significant decrease of their core self-evaluations when comparing them to a reference sample. Practical implications and recommendations that can be derived from these results are discussed.