709 research outputs found
Breeding progress in grain yield of winter wheat cultivars grown at different nitrogen levels in semiarid conditions
The objectives of this study were to estimate the progress in wheat genetic yield potential, associated with changes in some agronomic traits, under different N rates. Twenty-four cultivars of winter wheat (T. aestivtum L.) representing most of the cultivars released in Serbia from 1955 to 2006 were analyzed. The cultivars were grown for four years (2005-2008) in field trails with two levels of agronomic inputs (low nitrogen-N-45 and high nitrogen-N-110). Data were collected on 1000-kernel weight, kernels per spike, kernels per square meter, spikes per square meter, plant height, harvest index, heading time and grain yield. Mean difference between the two fertilization levels was 0.44 t ha(-1). The average rate of increase in yield potential per year of release, estimated from the slope, was 41 kg ha(-1) year(-1) and it was significantly different from zero (P lt = 0.01). It was 35 kg ha(-1) year(-1) or 0.55% at the low level of N input, and 46 kg ha(-1) year(-1) or 0.68% at the high level of N input. This suggests that modern cultivars are better adapted to high N input. Our results suggested that individual contribution of the most of analyzed traits may vary depending on the genotype as well as environmental conditions
Anisotropic inharmonic Higgs oscillator and related (MICZ-)Kepler-like systems
We propose the integrable (pseudo)spherical generalization of the
four-dimensional anisotropic oscillator with additional nonlinear potential.
Performing its Kustaanheimo-Stiefel transformation we then obtain the
pseudospherical generalization of the MICZ-Kepler system with linear and
potential terms. We also present the generalization of the
parabolic coordinates, in which this system admits the separation of variables.
Finally, we get the spherical analog of the presented MICZ-Kepler-like system.Comment: 7 page
Coats disease ‒ case report
Coats disease is a rare, in about 90% of cases unilateral idiopathic eye pathology. It is characterized by telangiectatic and aneurysmally altered retinal blood vessels and progressive intra- and subretinal exudation, which can lead to exudative retinal detachment. Most often the symptoms manifest in the advanced stages. Purpose: To report a case with Coats disease. 10 year old boy, admitted to the Eye Clinic of the University Alexandrovska Hospital – Sofia, with leucocoria and strabismus of the right eye. Method: Full ophthalmic and orthoptic examination, OCT. Results: 3B stage of Coats disease of the right eye was established. The chance for improvement after surgery was evaluated as very little, so our patient remained under observation with protective glasses and prevention of complications. Conclusion: It is of great importance to early diagnose the disease, so to have more treatment options
Gender influence in perception and adoption of e-learning platforms
The main objective of this study is to examine gender differences and the adoption of technology in
higher education students. TAM model is the tool used to measure the acceptance and use of e-learning of the
respondents. We used Partial Least Squares (PLS), specifically, the PLS multi-group analysis was used to
compare differences between groups. In summary, results show that students’ behavior of acceptance of elearning technology do not manifest statistically significant differences between women and men
Vitamin D status in children with myopia
Introduction. A dramatic increase of myopia worldwide has been observed in recent years. New risk factors for the development of myopia have been the target of numerous investigations. The basis of our research is the correlation between serum levels of vitamin D [25(OH)D] and myopia itself.Purpose: To find out the relationship between serum levels of 25(OH) D and myopia. Patients and methods: The study included 222 children with different refraction status. Full ophthalmologic examination, cycloplegic refraction, echobiometry were performed. The serum levels of 25(OH)D were measured by liquid chromatographic mass spectrometry (level of insufficiency < 80 nmol/L).Results: The average patients’ age (51% boys and 48,2% girls) was 11,7 y (SD ± 3,03). They were subdivided into two groups – children with myopia (84,7%) and those without myopia (15,3%). The mean serum 25(OH)D level of all tested was 61,48 nmol/L (16-140 nmol/L; SD ± 20,15); of myopia – 59,67 nmol/L (16-140 nmol/L; SD ± 19,30) and of the non-myopia group – 71,91 nmol/L (33-111 nmol/L; SD ± 21,79). There was a statistically significant difference in serum levels between the two groups (Р = 0,001). The risk of myopia was higher with the decrease of 25(OH)D values (OR = 1,028 ; 95% CI 1,008-1,048). Conclusion. In our investigation group we established low serum levels of 25(OH)D which indicated the need for conducting a population study of its status among Bulgarian children. The correlation between the higher risk of myopia and the vitamin D scarcity has to be further studied, also considering the factor of outdoor/sun-exposure time.
3D Oscillator and Coulomb Systems reduced from Kahler spaces
We define the oscillator and Coulomb systems on four-dimensional spaces with
U(2)-invariant Kahler metric and perform their Hamiltonian reduction to the
three-dimensional oscillator and Coulomb systems specified by the presence of
Dirac monopoles. We find the Kahler spaces with conic singularity, where the
oscillator and Coulomb systems on three-dimensional sphere and two-sheet
hyperboloid are originated. Then we construct the superintegrable oscillator
system on three-dimensional sphere and hyperboloid, coupled to monopole, and
find their four-dimensional origins. In the latter case the metric of
configuration space is non-Kahler one. Finally, we extend these results to the
family of Kahler spaces with conic singularities.Comment: To the memory of Professor Valery Ter-Antonyan, 11 page
Quantum oscillator as 1D anyon
It is shown that in one spatial dimension the quantum oscillator is dual to
the charged particle situated in the field described by the superposition of
Coulomb and Calogero-Sutherland potentials.Comment: 9 pages, LaTe
Why honey is effective as a medicine. 1. Its use in modern medicine
Honey has been used as a medicine for thousands of years and its curative properties are well documented. However, modern medicine turned its back on honey and it is only now, with the advent of multi-resistant bacteria, that the antibiotic properties of honey are being rediscovered
Espon-Interstrat. Espon in Integrated Territorial Strategies.
The INTERSTRAT project’s overall aim is “to encourage and facilitate the use of ESPON 2013 Programme findings in the creation and monitoring of Integrated Territorial Development Strategies (ITDS) and to support transnational learning about the actual and potential contribution of ESPON to integrated policy-making.” We defined integrated territorial development as ‘the process of shaping economic, social and environmental change through spatially sensitive policies and programmes’
Critique of deinstitutionalisation in postsocialist Central and Eastern Europe
In this paper, we explore critically deinstitutionalisation reform, focusing specifically on the postsocialist region of Central and Eastern Europe (CEE). We argue that
deinstitutionalisation in postsocialist CEE has generated re-institutionalising outcomes, including renovation of existing institutions and/or creation of new, smaller settings that have nevertheless reproduced key features of institutional life. To explain these trends, we first consider the historical background of the reform, highlighting the legacy of state socialism and the effects of postsocialist neoliberalisation. We then discuss the impact of ‘external’ drivers of deinstitutionalisation in CEE, particularly the European Union and its funding, as well as human rights discourses incorporated in the UN Convention on the Rights of Persons with Disabilities. The analysis is supported by looking at the current situation in Hungary and Bulgaria through recent reports by local civil society organisations. In conclusion, we propose some definitional tactics for redirecting existing resources towards genuine community-based services
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