A systematic literature review on the quality of moocs

This paper presents the findings from a systematic literature review on the quality of massive open online courses (MOOCs). The main research question was “How can the quality criteria for MOOCs identified in the analysed studies from the systematic literature review be best organ-ised in a categorisation scheme?” The systematic literature review was conducted using the PRISMA procedures. After conducting the screening and eligibility analysis according the pre-defined crite-ria, 103 studies were finally selected. The analysis was done in iterative cycles for continuous im-provements of the assignments and clustering of the quality criteria. The final version was validated in consensus through the categorisation and assignment of all 103 studies in a consistent way to four dimensions (pedagogical, organisational, technological, and social) and their sub-categories. This quality framework can be re-used in future MOOC research and the discussion of the analysed studies provides a current literature overview on the quality of MOOCs

The Quality Reference Framework for MOOC Design

This paper introduces "The Quality Reference Framework (QRF) for the Quality of MOOCs". It was developed by the European Alliance for the Quality of Massive Open Online Courses (MOOCs), called MOOQ that could involve in the QRF finalization more than 10,000 MOOC learners, designers, facilitators and providers. The QRF consists of three dimensions: Phases, Perspectives and Roles. It includes two quality instruments: the QRF Key Quality Criteria for MOOC experts and QRF Quality Checklist for MOOC beginners

Association mapping reveals gene action and interactions in the determination of flowering time in barley

The interaction between members of a gene network has an important impact on the variation of quantitative traits, and can influence the outcome of phenotype/genotype association studies. Three genes (Ppd-H1, HvCO1, HvFT1) known to play an essential role in the regulation of flowering time under long days in barley were subjected to an analysis of nucleotide diversity in a collection of 220 spring barley accessions. The coding region of Ppd-H1 was highly diverse, while both HvCO1 and HvFT1 showed a rather limited level of diversity. Within all three genes, the extent of linkage disequilibrium was variable, but on average only moderate. Ppd-H1 is strongly associated with flowering time across four environments, showing a difference of five to ten days between the most extreme haplotypes. The association between flowering time and the variation at HvFT1 and HvCO1 was strongly dependent on the haplotype present at Ppd-H1. The interaction between HvCO1 and Ppd-H1 was statistically significant, but this association disappeared when the analysis was corrected for the geographical origin of the accessions. No association existed between flowering time and allelic variation at HvFT1. In contrast to Ppd-H1, functional variation at both HvCO1 and HvFT1 is limited in cultivated barley

Upwelling of melt-depleted mantle under Iceland

Seafloor anomalies along mid-ocean ridges with exceptionally thick and compositionally distinct basaltic crust, for example, at Iceland, suggest that the underlying mantle is hotter and chemically different from the adjacent subridge mantle. Here we present hafnium and neodymium isotope ratios of peridotites from the Charlie Gibbs Transform Zone, which is located at the southern end of the Reykjanes Ridge south-west of Iceland. These peridotites are strongly depleted in incompatible elements with extremely high hafnium isotope ratios, suggesting that they had already melted to a large extent before being incorporated into the plume, at least 1 billion years ago, and thereby also became less dense. We argue that seismic velocity anomalies, geodynamic models and geochemical affinities of ridge basalts connect the peridotites from the Charlie Gibbs Transform Zone to the 'Iceland plume'. The thermochemical buoyancy of the moderately hot Iceland plume, but also that of other plumes worldwide, may therefore be strongly influenced by composition. Variable peridotite depletion along the rising Iceland plume could also cause the transient, density-driven pulses in plume flux, which have formed the V-shaped Reykjanes Ridge south of Iceland. Overall, expansion of a ridge-centred plume along adjacent ridges and melting of heterogeneous plume material explains the topographic swell, the seismic anomaly and the formation of V-shaped ridges, as well as the regional distribution of basalts with Icelandic affinity.The upwelling mantle beneath Iceland underwent melt depletion at least 1 billion years ago and is therefore compositionally buoyant, according to a study of neodymium and hafnium isotope ratios in peridotites from the Charlie Gibbs Transform Zone

Indirect and direct optical transitions in In0.5Ga0.5As/GaP quantum dots

We present a study of self-assembled In0.5Ga0.5As quantum dots on GaP(001) surfaces linking growth parameters with structural, optical, and electronic properties. Quantum dot densities from 5.0 × 107 cm−2 to 1.5 × 1011 cm−2 are achieved. A ripening process during a growth interruption after In0.5Ga0.5As deposition is used to vary the quantum dot size. The main focus of this work lies on the nature of optical transitions which can be switched from low-efficient indirect to high-efficient direct ones through improved strain relief of the quantum dots by different cap layers

Genetic dissection of photoperiod response based on GWAS of pre-anthesis phase duration in spring barley

Heading time is a complex trait, and natural variation in photoperiod responses is a major factor controlling time to heading, adaptation and grain yield. In barley, previous heading time studies have been mainly conducted under field conditions to measure total days to heading. We followed a novel approach and studied the natural variation of time to heading in a world-wide spring barley collection (218 accessions), comprising of 95 photoperiod-sensitive (Ppd-H1) and 123 accessions with reduced photoperiod sensitivity (ppd-H1) to long-day (LD) through dissecting pre-anthesis development into four major stages and sub-phases. The study was conducted under greenhouse (GH) conditions (LD; 16/8 h; ∼20/∼16°C day/night). Genotyping was performed using a genome-wide high density 9K single nucleotide polymorphisms (SNPs) chip which assayed 7842 SNPs. We used the barley physical map to identify candidate genes underlying genome-wide association scans (GWAS). GWAS for pre-anthesis stages/sub-phases in each photoperiod group provided great power for partitioning genetic effects on floral initiation and heading time. In addition to major genes known to regulate heading time under field conditions, several novel QTL with medium to high effects, including new QTL having major effects on developmental stages/sub-phases were found to be associated in this study. For example, highly associated SNPs tagged the physical regions around HvCO1 (barley CONSTANS1) and BFL (BARLEY FLORICAULA/LEAFY) genes. Based upon our GWAS analysis, we propose a new genetic network model for each photoperiod group, which includes several newly identified genes, such as several HvCO-like genes, belonging to different heading time pathways in barley

Разработка информационно-измерительного комплекса для учета расхода электроэнергии в многоквартирном доме

Объектом исследования является автоматизированная система учета расхода электроэнергии в многоквартирном доме. Цель работы – разработать автоматизированную систему учета расхода электроэнергии в многоквартирном доме, с передачей данных на центральный сервер ресурсоснабжающей организации. В процессе исследования проводился сбор данных, систематизация и анализ информации по теме данного дипломного проекта, проектирование АСКУЭ. Область применения: учет расхода энергоресурсов бытовых потребителей.The object of research is automated system of metering of electricity consumption in an apartment building. Purpose - to develop an automated electricity metering system in an apartment building, with the transfer of data to a central server power company. The study was conducted to collect data, organize and analyze information on the subject of the degree project, the design of AMR. Scope: Accounting consumption of household energy consumers

Growth and structure of In0.5Ga0.5Sb quantum dots on GaP(001)

Stranski-Krastanov (SK) growth of In0.5Ga0.5Sb quantum dots (QDs) on GaP(001) by metalorganic vapor phase epitaxy is demonstrated. A thin GaAs interlayer prior to QD deposition enables QD nucleation. The impact of a short Sb-flush before supplying InGaSb is investigated. QD growth gets partially suppressed for GaAs interlayer thicknesses below 6 monolayers. QD densities vary from 5 × 109 to 2 × 1011 cm−2 depending on material deposition and Sb-flush time. When In0.5Ga0.5Sb growth is carried out without Sb-flush, the QD density is generally decreased, and up to 60% larger QDs are obtained

Re-Os isotope and platinum group elements of a FOcal ZOne mantle source, Louisville Seamounts Chain, Pacific ocean

The Louisville Seamount Chain (LSC) is, besides the Hawaiian-Emperor Chain, one of the longest-lived hotspot traces. We report here the first Re-Os isotope and platinum group element (PGE) data for Canopus, Rigil, and Burton Guyots along the chain, which were drilled during IODP Expedition 330. The LSC basalts possess (187Os/188Os)i = 0.1245–0.1314 that are remarkably homogeneous and do not vary with age. A Re-Os isochron age of 64.9 ± 3.2 Ma was obtained for Burton seamount (the youngest of the three seamounts drilled), consistent with 40Ar-39Ar data. Isochron-derived initial 187Os/188Os ratio of 0.1272 ± 0.0008, together with data for olivines (0.1271–0.1275), are within the estimated primitive mantle values. This (187Os/188Os)i range is similar to those of Rarotonga (0.124–0.139) and Samoan shield (0.1276–0.1313) basalts and lower than those of Cook-Austral (0.136–0.155) and Hawaiian shield (0.1283–0.1578) basalts, suggesting little or no recycled component in the LSC mantle source. The PGE data of LSC basalts are distinct from those of oceanic lower crust. Variation in PGE patterns can be largely explained by different low degrees of melting under sulfide-saturated conditions of the same relatively fertile mantle source, consistent with their primitive mantle-like Os and primordial Ne isotope signatures. The PGE patterns and the low 187Os/188Os composition of LSC basalts contrast with those of Ontong Java Plateau (OJP) tholeiites. We conclude that the Re-Os isotope and PGE composition of LSC basalts reflect a relatively pure deep-sourced common mantle sampled by some ocean island basalts but is not discernible in the composition of OJP tholeiites