Understanding teacher design practices for digital inquiry-based science learning: the case of Go-Lab.

Designing and implementing online or digital learning material is a demanding task for teachers. This is even more the case when this material is used for more engaged forms of learning, such as inquiry learning. In this article, we give an informed account of Go-Lab, an ecosystem that supports teachers in creating Inquiry Learning Spaces (ILSs). These ILSs are built around STEM-related online laboratories. Within the Go-Lab ecosystem, teachers can combine these online laboratories with multimedia material and learning apps, which are small applications that support learners in their inquiry learning process. The Go-Lab ecosystem offers teachers ready-made structures, such as a standard inquiry cycle, alternative scenarios or complete ILSs that can be used as they are, but it also allows teachers to configure these structures to create personalized ILSs. For this article, we analyzed data on the design process and structure of 2414 ILSs that were (co)created by teachers and that our usage data suggest have been used in classrooms. Our data show that teachers prefer to start their design from empty templates instead of more domain-related elements, that the makeup of the design team (a single teacher, a group of collaborating teachers, or a mix of teachers and project members) influences key design process characteristics such as time spent designing the ILS and number of actions involved, that the characteristics of the resulting ILSs also depend on the type of design team and that ILSs that are openly shared (i.e., published in a public repository) have different characteristics than those that are kept private.

Heterogeneity in Palaeolithic Population Continuity and Neolithic Expansion in North Africa.

North Africa is located at the crossroads of the Mediterranean Sea, the Middle East, and the Sahara Desert. Extensive migrations and gene flow in the region have shaped many different cultures and ancestral genetic components through time [1-6]. DNA data from ancient Moroccan sites [7, 8] has recently shed some light to the population continuity-versus-replacement debate, i.e., the question of whether current North African populations descend from Palaeolithic groups or, on the contrary, subsequent migrations swept away all pre-existing genetic signal in the region. In the present study, we analyze 21 complete North African genomes and compare them with extant and ancient genome data in order to address the demographic continuity-versus-replacement debate, to assess whether these demographic events were homogeneous (including Berber and Arabic-speaking groups), and to explore the effect of Neolithization and posterior migration waves. The North African genetic pool is defined as a melting pot of genetic components, including an endemic North African Epipalaeolithic component at low frequency that forms a declining gradient from Western to Eastern North Africa. This scenario is consistent with Neolithization having shaped most of the current genetic variation in the region when compared to posterior back-to-North-Africa migration waves such as the Arabization. A common and distinct genetic history of the region is shown, with internal different proportions of genetic components owing to differential admixture with surrounding groups as well as to genetic drift due to isolation and endogamy in certain populations.

Whole-genome sequence analysis of a Pan African set of samples reveals archaic gene flow from an extinct basal population of modern humans into sub-Saharan populations.

BACKGROUND: Population demography and gene flow among African groups, as well as the putative archaic introgression of ancient hominins, have been poorly explored at the genome level. RESULTS: Here, we examine 15 African populations covering all major continental linguistic groups, ecosystems, and lifestyles within Africa through analysis of whole-genome sequence data of 21 individuals sequenced at deep coverage. We observe a remarkable correlation among genetic diversity and geographic distance, with the hunter-gatherer groups being more genetically differentiated and having larger effective population sizes throughout most modern-human history. Admixture signals are found between neighbor populations from both hunter-gatherer and agriculturalists groups, whereas North African individuals are closely related to Eurasian populations. Regarding archaic gene flow, we test six complex demographic models that consider recent admixture as well as archaic introgression. We identify the fingerprint of an archaic introgression event in the sub-Saharan populations included in the models (~ 4.0% in Khoisan, ~ 4.3% in Mbuti Pygmies, and ~ 5.8% in Mandenka) from an early divergent and currently extinct ghost modern human lineage. CONCLUSION: The present study represents an in-depth genomic analysis of a Pan African set of individuals, which emphasizes their complex relationships and demographic history at population level.

Control and synchronization of hyperchaotic states in mathematical models of Bènard-Marangoni convective experiments.

Mathematical models are of great interest for experimentalists since they provide a way for controlling and synchronizing different chaotic states. In previous works, we have used a Takens-Bogdanov (T-B) system under hyperchaotic dynamic conditions (two or more positive Lyapunov exponents) because they adequately reflect the dynamics of the patterns in small aspect ratio pre-turbulent Bènard-Marangoni convection near a codimension-2 point (with resonance between 2:1 modes), in square symmetry (D4). In this paper, we discuss the coupling of two different four dimensional hyperchaotic models derived from the Lorenz equations by using the same method introduced in previous works. As in the former system of used equations, we found that two identical hyperchaotic systems based on either Chen or Lü equation systems evolve into different states in the pattern space, where the synchronization state or the complexity could be controlled by a small external signal, as was shown in T-B equations.

The genetic landscape of Mediterranean North African populations through complete mtDNA sequences.

BACKGROUND: The genetic composition of human North African populations is an amalgam of different ancestral components coming from the Middle East, Europe, south-Saharan Africa and autochthonous to North Africa. This complex genetic pattern is the result of migrations and admixtures in the region since Palaeolithic times. AIMS: The objective of the present study is to refine knowledge of the population history of North African populations through the analysis of complete mitochondrial sequences. SUBJECTS AND METHODS: This study has sequenced complete mitochondrial DNAs (mtDNAs) in several North African and neighbouring individuals. RESULTS: The mtDNA haplogroup classification and phylogeny shows a high genetic diversity in the region as a result of continuous admixture. The phylogenetic analysis allowed us to identify a new haplogroup characterised by positions 10 101 C and 146 C (H1v2), a sub-branch of H1v, which is restricted to North Africa and whose origins are estimated as ∼4000 years ago. CONCLUSIONS: The analysis of the complete mtDNA genome has allowed for the identification of a North African sub-lineage that might be ignored by the analysis of partial mtDNA control region sequences, highlighting the phylogeographic relevance of mtDNA complete sequence analysis.