Sea-bed photographs (benthos) from the AWI-Hausgarten area along OFOS profile PS62/191-1

Although the use of deep-sea imagery considerably increased during the last decades, reports on nekton falls to the deep seafloor are very scarce. Whereas there are a few reports describing the finding of whale carcasses in the deep north-eastern and south-eastern Pacific, descriptions of invertebrate or vertebrate food-falls at centimetre to metre scale are extremely rare. After 4 years of extensive work at a deep-sea long-term station in northern polar regions (AWI-"Hausgarten"), including large-scale visual observations with various camera systems covering some 10 000 m2 of seafloor at water depths between 1250 and 5600 m, this paper describes the first observation of a fish carcass at about 1280 m water depth, west off Svålbard. The fish skeleton had a total length of 36 cm and an approximated biomass of 0.5 kg wet weight. On the basis of in situ experiments, we estimated a very short residence time of this particular carcass of about 7 h at the bottom. The fast response of the motile deep-sea scavenger community to such events and the rapid utilisation of this kind of organic carbon supply might partly explain the extreme rarity of such an observation.

THE ELEMENTARY TEACHERS’ PERCEPTIONS OF MOTIVATION FOR AND THE PRINCIPAL’S INFLUENCE ON THEIR ENGAGEMENT IN SELF-DIRECTED PROFESSIONAL DEVELOPMENT

All teachers participate in self-directed professional development (PD) at some point in their careers; however, the degree to which this participation takes place varies greatly from teacher to teacher and is influenced by the leadership of the school principal. The motivation behind why teachers choose to engage in PD is an important construct. Therefore, there is a need for better understanding of the leader’s role with respect to how and why teachers engage in self-directed professional development. The purpose of the research was to explore the elementary teachers’ motivation for and the school principal’s influence on their engagement in self-directed professional development. Three research questions guided this study: 1. What motivates teachers to engage in self-directed professional development? 2. What are the conditions necessary for promoting teachers’ engagement in self-directed professional development? 3. What are teachers’ perceptions of the principal’s role in supporting, fostering, encouraging, and sustaining the professional development of teachers? A qualitative research approach was adopted for this study. Six elementary teachers from one south-eastern Ontario school board, consisting of three novice and three more experienced teachers, provided their responses to a consistent complement of 14 questions. Their responses were documented via individual interviews, transcribed verbatim, and thematically analysed. The findings suggested that, coupled with the individual motivating influences, the culture of the school was found to be a conditional dynamic that either stimulated or dissuaded participation in self-directed PD. The school principal provided an additional catalyst or deterrence via relational disposition. When teachers felt their needs for competency, relatedness, and autonomy were satisfied, the conditions necessary to motivate teachers to engage in PD were fulfilled. A principal who personified the tenets of transformational leadership served to facilitate teachers’ inclinations to take on PD. A leadership style that was collaborative and trustful and allowed for personal autonomy was a dominant foundational piece that was critical for participant participation in self-directed PD. Finally, the principals were found to positively impact school climate by partaking in PD alongside teachers and ensuring there was a shared vision of the school so that teachers could tailor PD to parallel school interests.

Impact of selection and demography on the diffusion of lactase persistence.

The lactase enzyme allows lactose digestion in fresh milk. Its activity strongly decreases after the weaning phase in most humans, but persists at a high frequency in Europe and some nomadic populations. Two hypotheses are usually proposed to explain the particular distribution of the lactase persistence phenotype. The gene-culture coevolution hypothesis supposes a nutritional advantage of lactose digestion in pastoral populations. The calcium assimilation hypothesis suggests that carriers of the lactase persistence allele(s) (LCT*P) are favoured in high-latitude regions, where sunshine is insufficient to allow accurate vitamin-D synthesis. In this work, we test the validity of these two hypotheses on a large worldwide dataset of lactase persistence frequencies by using several complementary approaches. Methodology We first analyse the distribution of lactase persistence in various continents in relation to geographic variation, pastoralism levels, and the genetic patterns observed for other independent polymorphisms. Then we use computer simulations and a large database of archaeological dates for the introduction of domestication to explore the evolution of these frequencies in Europe according to different demographic scenarios and selection intensities. Conclusions Our results show that gene-culture coevolution is a likely hypothesis in Africa as high LCT*P frequencies are preferentially found in pastoral populations. In Europe, we show that population history played an important role in the diffusion of lactase persistence over the continent. Moreover, selection pressure on lactase persistence has been very high in the North-western part of the continent, by contrast to the South-eastern part where genetic drift alone can explain the observed frequencies. This selection pressure increasing with latitude is highly compatible with the calcium assimilation hypothesis while the gene-culture coevolution hypothesis cannot be ruled out if a positively selected lactase gene was carried at the front of the expansion wave during the Neolithic transition in Europe.

Sedimentology of a Middle Jurassic Base-of-Slope environment, Cutri Formation, Mallorca

The Cutri Formation’s, type location, exposed in the NW of Mallorca, Spain has previously been described by Álvaro et al., (1989) and further interpreted by Abbots (1989) unpublished PhD thesis as a base-of-slope carbonate apron. Incorporating new field and laboratory analysis this paper enhances this interpretation. From this analysis, it can be shown without reasonable doubt that the Cutri Formation was deposited in a carbonate base-of-slope environment on the palaeowindward side of a Mid-Jurassic Tethyan platform. Key evidence such as laterally extensive exposures, abundant deposits of calciturbidtes and debris flows amongst hemipelagic deposits strongly support this interpretation.