428 research outputs found
Noise considerations in twin-core channel equalisers
Fibre optic channel equalisers are devices of prime importance in multi-channel telecommunication links and networks. They are used to compensate for the channel power imbalances accumulated along amplified long links and stabilise the channel optical powers. In multi-stage amplified optical links, channel power imbalances occur as a result two factors. Firstly, the emission and absorption cross-section variations across the erbium-doped fibre amplifier (EDFA) bandwidth result in channels experiencing different gains and acquiring unequal output power. Secondly, the output power imbalances are further deteriorated by the fact that the Er3+ transition is predominantly homogeneously broadened at room temperature. Therefore, the strongest signal (channel) saturates the gain medium and compresses the gain uniformly at the expense of the power of the weaker signals
Report on the development of the national assessment method for the ecological status of natural lakes in Greece, using the Biological Quality Element “Macrophytes” (Hellenic Lake Macrophytes-HeLM assessment method)
This report discusses the development of the national ecological assessment method for Greek natural lakes, based on the Biological Quality Element (BQE) “macrophytes”. Due to lack of a common natural lake type within the Mediterranean Lake Geographical intercalibration Group, there has not been a Med GIG Intercalibration Exercise for macrophytes in natural lakes. As a result, there are neither proposed assessment methods with common boundaries within the Med GIG, nor proposed metrics for the assessment of lakes based on macrophytes. It is noted that at the Mediterranean Lake Phytoplankton GIG Intercalibration Report, Member States defined two common water body types (L-M5/7 and L-M8) for reservoirs but none for natural lakes. The operation of the Greek water monitoring network started in 2012, following the publication of a Joint Ministerial Decision in 2011. The development of the current assessment method, as described in this report, is based on the data from this national water monitoring network. In particular, 50 lake water bodies (including 26 reservoirs) have been included in the monitoring network, out of which 16 have been monitored for macrophytes during the 3-year period of 2013-2015. Eight of them are warm monomictic, deep natural lakes with mean depth >9m (GR-DNL), when the other eight are polymictic, shallow natural lakes with mean depth 3-9m (GR-SNL). In these 16 lakes, a total of 272 monitoring sites were established for sampling macrophytes, which resulted in an equal number of macrophytic sampling transects, the data of which have been added in the national dataset. Thirty six of these sites were revisited during the 3-year period, and a total of 308 measurements of maximum macrophytic colonization depth were made. On this national dataset, the most suitable lake macrophyte based assessment components proposed by WISER deliverables D3.2-1 (Kolada et al., 2009), D3.2-2 (Dudley et al., 2011) and D3.2-3 (Kolada et al., 2011) were tested, in various combinations, so as to reach a final form that can be used as a national assessment method for Greece. As already mentioned, this is the first effort to establish a national method, which may need additions and improvements in the future, as well as intercalibration exercises among Member States in the Mediterranean GIG
Optimization of linearly chirped grating dispersion compensated systems
The optimum design for a 10Gb/s NRZ chirped fibre grating dispersion compensated system operating at 1.55µm over standard fibre is investigated. The study considers self-phase modulation, dispersion, modulator chirp and amplifier noise. Transmission over 1700km of fibre may be achieved by incorporating gratings every 200km and optimising the modulator chirp
HeLM: a macrophyte-based method for monitoring and assessment of Greek lakes
Zervas, D., Tsiaoussi, V. & Tsiripidis, I. HeLM: a macrophyte-based method for monitoring and assessment of Greek lakes. Environ Monit Assess 190, 326 (2018). https://doi.org/10.1007/s10661-018-6708-
A phytosociological survey of aquatic vegetation in the main freshwater lakes of Greece. Vegetation
Zervas D, Tsiripidis I, Bergmeier E, Tsiaoussi V (2020) A phytosociological survey of aquatic vegetation in the main freshwater lakes of Greece. Vegetation Classification and Survey 1: 53-75. https://doi.org/10.3897/VCS/2020/48377This study aims to contribute to the knowledge of European freshwater lake ecosystems with updated and new information on aquatic plant communities, by conducting national-scale phytosociological research of freshwater lake vegetation in Greece. Moreover, it investigates the relationship between aquatic plant communities and lake environmental parameters, including eutrophication levels and hydro-morphological conditions. Study area: Lakes in Greece, SE Europe
Grazing Animal Production Systems and Grazing Land Characteristics in a Semi-Arid Region of Greece
Rough grazing in Greece cover about 40% of the total land area, is publicly owned and managed extensively (Hadjigeorgiou et al., 2002). The Prefecture of Larisa is in the centre of Greece, and has 212,000 ha of rough grazing land, with a variable topography ranging from sea level up to 3,000 m a.s.l. This area is utilized by a total population of 135,000 LU (mainly sheep, goats and some suckler cows), which consumes annually an appreciable fraction of their total nutrient requirements from rough grazing
Limited Depressive and Anxiety Symptoms Late in Pregnancy Are Not Related to Neonatal Outcomes
Background: Prior studies have reported inconsistent findings regarding the link between antenatal depressive and anxiety symptomatology, with neonatal outcomes.
Objectives: The aim of the present study was to assess the possible association of prenatal depressive and anxiety symptoms, in the third trimester of pregnancy, with perinatal outcomes (birth weight of the newborn, Apgar score and the newborn’s admission in neonatal intensive care unit) in a sample of pregnant women, in Greece.
Patients and Methods: A total of 117 women from Athens, during the 32nd to 35th week of pregnancy, participated in the study. Demographic and obstetric history data, as well as neonatal outcomes, were recorded. Three self-administered psychometric scales (Beck depression inventory (BDI), Edinburg postnatal depression scale (EPDS) and beck anxiety inventory (BAI)) were used to evaluate in detail the prenatal depressive and anxiety symptoms. Descriptive statistics, Spearman’s Rho coefficients, Mann-Whitney U and Kruskal-Wallis testes were applied to analyze the data.
Results: On the basis of BDI, 81.1% of the sample showed minimal, 15.4% mild, 2.6% moderate and 0.9% severe depressive symptoms, respectively. Furthermore, 80.3% of the participants, scored on EPDS below the cut-off point for a likely diagnosis of depression. According to BAI scale, 43.6% showed minimal, 42.7% women mild, 10.3% moderate and 3.4% severe anxiety symptoms. No statistically significant correlations were found between depressive and anxiety symptoms and neonatal outcomes (birth weight, Apgar score and admission in neonatal intensive care unit).
Conclusions: Limited levels of prenatal depressive and anxiety symptoms do not seem to be associated with neonatal outcomes. In clinical practice, pregnant women, who suffer from low levels of prenatal depressive and anxiety symptoms, may be reassured, in respect of the adverse outcomes of these mood symptoms on the neonate
Online simulation games for guided learning: a sport business case study
Business simulation games (BSG) have become a very popular pedagogical tool in university courses and programmes all around the world. Their immense popularity has been a subject of research and academic discourse, especially the past twenty years when many experts have called for more student-centric and reality based pedagogical approaches. Their implementation in business schools has been particularly successful, leading to improved student outcomes, satisfaction and skills development. Their use in sport business courses, though, has been surprisingly neglected in the pertinent literature. In the present study, we attempt to close this gap in the literature by exploring the effectiveness of BSG implementation in sport business courses, as well as the conditions and factors that facilitate the teaching and learning experience in such cases. In doing so, this research followed a mixed methods case study approach. Our findings expand previous conclusions and arguments on the effectiveness of BSGs’ use in universities, to the case of sport business courses. They also identify conditions under which the teaching and learning experience is improved, namely effective group work, student engagement, satisfaction from the game and others. Based on these findings we propose useful recommendations and suggestions for future research. We also establish BSG as a form of independent, guided learning activity which is facilitated merely by individual engagement and group work and less from the tutors
15 PROFESOR DILANTIK AHLI SENAT USM ISI KEKOSONGAN SESI 2014-2017
USM, PULAU PINANG, 26 Ogos 2016 - Pemilihan Profesor sebagai Ahli Senat Universiti Sains Malaysia
(USM) bagi mengisi kekosongan sesi 2014-2017 telah diadakan pada 18 Ogos 2016 lalu secara atas
talian atau e-Undi Senat
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