Primary school teachers need adequate professional knowledge and motivational orientations to qualify scientifically and technologically literate students. Previous studies have focused on the impact of coursework on (pre-service) primary teachers’ content knowledge, rather than on the development of academic self-concepts. In addition, the influence of the course format and the major field of study has not been investigated much to this date. Thus, this study examines the effects of an interdisciplinary course on pre-service primary teachers’ content knowledge and academic self-concepts in science and technology using a quasi-experimental, quantitative, pre-post-follow-up design (n = 202). Whilst no significant changes in knowledge were revealed for the baseline group not participating in the course, significant short-term and long-term cognitive gains were found for the experimental group. Biology-, chemistry-, physics- and technology-related self-concepts increased significantly when participating in the course. The results also indicate that the course format and major field of study can have an impact on the development of pre-service teachers’ professional knowledge. Regarding the development of academic self-concepts in the experimental group, it can be assumed that both the weekly and block course format are beneficial for heterogeneous learner groups consisting of pre-service teachers with different major fields of study.
African elephants are capable of discriminating scents up to a single changed molecule and show the largest reported repertoire of olfactory receptor genes. Olfaction plays an important role in family bonding. However, to the best of our knowledge, no empirical data exist on their ability to remember familiar scents long-term. In an ethological experiment, two mother-daughter pairs were presented with feces of absent kin, absent non-kin, and present non-kin. Video recordings showed reactions of elephants recognizing kin after long-term separation but only minor reactions to non-kin. Results give the empirical implication that elephants have an olfactory memory longer than 1 year and up to 12 years and can distinguish between kin and non-kin just by scent. These findings confirm the significance of scent for family bonds in African elephants.
The introduction of elephants into new groups is necessary for breeding programmes. However, behavioural studies on the reactions of these animals at first encounters are missing. In the present study, female African elephants (Loxodonta africana) living in zoos were observed during unifications with unfamiliar elephants (introduction of two to one females and one to two females; n = 6) and reunifications with related elephants (two mother–daughter-pairs; n = 4) that were separated for 2 and 12 years, respectively. First encounters of the elephants were observed and recorded by scan sampling. The parameters measured were (a) signs of the characteristic Greeting Ceremony, (b) distance to the fence separating the elephants during first contact, and (c) time until trunks touched for the first time. The data were statistically analysed with SPSS. The results showed that related elephants performed a full Greeting Ceremony on reunifications. Unrelated elephants only expressed a minor greeting. During first encounters, related elephants predominantly showed affiliative behaviour (p = 0.001), whilst unrelated elephants expressed more agonistic behaviour (p = 0.001). The distance to the fence was significantly smaller for related elephants than for unrelated elephants (p = 0.038). first contact of trunks occurred on average after 3.00 s. in related elephants and 1026.25 s. in unrelated elephants. These findings indicate that related elephants recognise their kin after up to 12 years of separation, meet them with a full Greeting Ceremony during reunification, and seek contact to the related elephant, while unrelated elephants are hesitant during unifications with unfamiliar elephants and express more agonistic behaviour. The results testify that zoo elephants show the same species-specific social behaviour as their conspecifics in the wild. It also confirms the cognitive abilities of elephants and the significance of matrilines for breeding programmes.
The precise mechanisms that allow animals and phototrophic organisms to form a stable photosymbiotic relationship are still unknown. While previous studies focused on genomic adaptations of the animal host, more recent research looked into the role of bacteria in photosymbiosis. Here, we analyzed the core microbiome of the sea slug Berghia stephanieae and its food source Exaiptasia diaphana to understand if the microbiome and the linked bacterial metabolic pathways differ between unstable and stable photosymbiosis. This sea slug feeds solely on the model cnidarian E. diaphana and steals their photobionts which the slug can only maintain for a week. We additionally examined the influence of light and starvation stress on the slug’s bacterial composition, which are common experimental set-ups to elucidate the photosymbiotic relationship in the slugs. Our results show that the core microbiome of B. stephanieae and E. diaphana differed significantly suggesting that the slug’s microbiome is not obtained from its food source or the water column and indicates a vertical transmission. Further, differences in metabolic pathways imply that the microbiome of B. stephanieae does not support a stable photosymbiosis due to an insufficient nitrogen cycle on part of the photobiont. Starving the slugs induced a shift towards an increased abundance of potential pathogens and led to a downregulation in the sulphur cycle. Yet, starvation in darkness resulted in the depletion of most bacteria and induced a metabolic switch toward bacterial nitrogen fixation. This emphasizes that different holobiont members contribute to essential nutrient cycles, and it is important to look beyond the photobiont to understand the sea slug holobiont.
30 March 2022 in lnternational Electronic Journal of Elementary Education
Primary school students often do not have differentiated conceptions of human organs and organ systems. As understanding the inner structure of the human body is an elementary prerequisite for the development of health awareness, appropriate forms of teaching must be developed to modify students’ fragmented preconceptions about the inside of their bodies into scientifically accurate concepts. Anatomical models are considered a medium to raise awareness of organs and their systemic integration; however, only a few studies have investigated their effectiveness in the context of primary school. This intervention study, therefore, examines the effect of anatomical models on the conceptions of inner organs in German primary school students (N = 45) in a pretest, posttest, and follow-up test design with anatomy teaching between pre- and posttests. Concepts were measured using students' drawings in two treatment groups (anatomical models versus anatomical illustrations). While in both treatment groups students' conceptions changed toward more scientific concepts, there was little difference in the changes between the two groups. There were even indications that the students of the control group showed more pronounced increases, for example, in long-term systemic integration of the organs. We discuss the reasons for this and furnish recommendations for effective teaching practices.
African zoo elephants live in safe environments with sufficient resources, are protected from threats, and have their health and body conditions cared for. Calves ex situ undergo the same developmental stages as in situ and are raised by the whole family unit. However, due to environmental differences, there might be behavioral modifications between calves in situ and ex situ. We hypothesize that these differences increase with ongoing generations. This ethological study compares social and general behavior and the distance calves kept to their mothers’ between calves of the first (F1) and second (F2) zoo generation and the wild. Using ethological methods, data were collected for ~90 in situ calves and 16 ex situ (8 F1, 8 F2) between the ages of 0.5 to 4 years (120 observation hours per group). Results showed that in situ calves spent significantly more time close to mothers than the F1 and the F2 zoo generations (F1/in situ: p = <0.001; F2/in situ: p = 0.007). The behaviors of eating, drinking, trunk movement, washing, and affiliative behaviors showed significant differences between in situ and ex situ calves. The amount and distribution of affiliative and agonistic behavior initiated and received by calves was displayed with a greater variety ex situ. Ex situ calves not only performed affiliative but, in contrast to the in situ, also agonistic behavior (F1/in situ: initiated p = 0.002, received p = 0.010; F2/in situ: initiated p = 0.050, received p = 0.037). The comparison of zoo generations suggests that differences did not increase with the generation. The more casual binding between mothers and offspring in zoos and the age-dependent improvement of social behavior of zoo-born calves are seen as a result of elephants’ adaptation to secure zoo conditions. The results of this study agree with the faster development of ex situ African elephants, like earlier puberty and more frequent breeding patterns, as known from the literature.