62 research outputs found

    The value of arboreta in South Africa

    Get PDF
    Significance:• Arboreta are documented, living collections of ligneous species cultivated for research, education and display.• Arboreta are a valuable resource for the forestry industry as gene banks.• Arboreta, together with botanic gardens, form a useful network of sentinel sites for plant pathogens and invasive species.• A survey of the species composition and status     of  arboreta in South Africa would be an important contribution to our botanical knowledge

    Effective recruitment method for the marketing department of a metallurgical enterprise

    Get PDF
    This paper presents some solutions to recruit staff for the Marketing Department of a metallurgical enterprise. Our goal is to present the psychological characteristics of a certain category of employees on a sample of 107 employees and to evaluate the relationship between the motivation to work and those characteristics. In order to realize such evaluation we used the linear mixed effects model in the statistical software program R. The results showed that a significant effect on work motivation have factors like work climate and the employee agreeability

    Electronic reconstruction at SrMnO3-LaMnO3 superlattice interfaces

    Full text link
    We use resonant soft x-ray scattering to study electronic reconstruction at the interface between the Mott insulator LaMnO3 and the "band" insulator SrMnO3. Superlattices of these two insulators were shown previously to have both ferromagnetism and metallic tendencies [Koida et al., Phys. Rev. B 66, 144418 (2002)]. By studying a judiciously chosen superlattice reflection we show that the interface density of states exhibits a pronounced peak at the Fermi level, similar to that predicted by Okamoto et al. [Phys. Rev. B 70, 241104(R) (2004)]. The intensity of this peak correlates with the conductivity and magnetization, suggesting it is the driver of metallic behavior. Our study demonstrates a general strategy for using RSXS to probe the electronic properties of heterostructure interfaces.Comment: 4.2 pages, 4 figure

    Features of Heart Rate Variability and Early Postinfarction Remodeling Process in Patients with Recurrent Myocardial Infarction

    Get PDF
    The purpose of this study was to evaluate the heart rate variability (HRV) level and the features of early post-infarction left ventricular remodeling (PIR) in patients with recurrent myocardial infarction (MI), which developed within six months post the initial Q-wave MI (Q-MI). Material and Methods: The study surveyed 105 male patients between 29 and 69 years of age (mean age 52.08±8.5), who underwent a Q-MI and who, for various reasons, have not undergone coronary angiography. All patients underwent echocardiography and the LVM, EDV, ESV and their indexed values, as well as the ejection fraction were determined, including Holter ECG monitoring. In the interim, analysis included the indicators recommended by the standards of measurement, physiological interpretation and clinical use of heart rate variability, such as SDNN, SDANN and RMSSD. The reduction of the total reduction of HRV was taken as SDNN≤100ms, and the marked reduction in HRV - SDNN≤50ms. Results: All the patients were divided into two groups: Group I consisted of patients who, within six months after the initial Q-wave MI, developed fatal or nonfatal reinfarction; Group II included those patients with a favorable course of the disease. The patients in both groups belonged to a somewhat similar age category. By localization of MI, occurrence of AH, as well as the incidence of LV aneurysm, both groups were comparable. However, the Group I patients in acute Q-MI showed significantly more preserved signs of residual myocardial ischemia, which was manifested as early post-infarction angina. The average values of SDNN in patients in Group I were noted to be significantly lower than that in the Group II patients. The same ratio was observed in both groups and also the indicator of SDANN, whereas the mean RMSSD values of the patients of both groups were not significantly different. The percentage of patients with reduced HRV in Group I was 1.8 times higher than that in Group II, including those patients with a marked reduction in HRV, which were 25% and 5.1% in Groups I and II, respectively. The patients in Group I compared with Group II patients had significantly higher values for LVM, EDV, ESV, as well as their indexed values for LVMI, iEDV, and iESV. The average values of EF in Group I were significantly lower than those in Group II. Conclusion: In patients with recurrent MI, which had developed within six months from the time of the initial Q-infarction in the acute phase of the disease, significantly more preserved signs of residual ischemia were revealed. The average EF, SDNN and SDANN values in these patients were significantly lower than in patients having a favorable course of the disease. Patients with recurrent MI differed significantly by showing higher values of the left ventricular mass, left ventricular volume indices, as well as the indexed values determined during the 10-14 day period of the primary IM

    An observational network of ground surface temperature under different land-cover types on the northeastern Qinghai–Tibet Plateau

    Get PDF
    Ground surface temperature (GST), measured at approximately 5 cm in depth, is a key controlling parameter for subsurface biophysical processes at the land–atmosphere boundary. This work presents a valuable dataset of GST observations at various spatial scales in the Headwater Area of the Yellow River (HAYR), a representative area of high-plateau permafrost on the northeastern Qinghai–Tibet Plateau (QTP). GST was measured every 3 h using 72 iButton temperature loggers (DS1922L) at 39 sites from 2019 to 2020. At each site, GST was recorded in two plots at distances from 2 to 16 m under similar and different land-cover conditions (steppe, meadow, swamp meadow, and bare ground). These sensors proved their reliability in harsh environments because there were only 165 biased measurements from a total of 210 816. A high significant correlation (&gt;0.96, p&lt;0.001) was observed between plots, with a mean absolute error (MAE) of 0.2 to 1.2 °C. The daily intra-plot differences in GST were mainly &lt;2 °C for sites with similar land cover in both plots and &gt;2 °C when GST of bare ground was compared to that of sites with vegetation. From autumn to spring, the differences in GST could increase to 4–5 °C for up to 15 d. The values of the frost number (FN) were quite similar between the plots with differences in FN &lt;0.05 for most of the sites. This dataset complements the sparse observations of GST on the QTP and helps to identify the permafrost distribution and degradation at high resolution as well as to validate and calibrate the permafrost distribution models. The datasets are openly available in the National Tibetan Plateau/Third Pole Environment Data Center (https://doi.org/10.11888/Cryos.tpdc.272945, Şerban and Jin, 2022).</p

    Fresh Water Resources in the Natura 2000 Pricop-Huta Certeze and Tisa Superioară Protected Areas

    Get PDF
    The Transcarpatic Basin which includes the Maramureş Basin (and within it the PHCTS area) is the largest intra-Carpathian lowland area, structured on a substrate with different geology, consisting in igneous rocks and crystalline schists, in the high areas and sandstones, conglomerates, marl, clay and sands in the central lower part. These features along with important rainfall amounts (up to 1800 mm in Ukrainian side) create conditions for a surplus in water resources budget, along with extreme hydrological events which are becoming very common. The average discharge values in PCHTS area go up to 40 l/s.km2 in high mountain area, while in the lowland space the values are around to 5 l/s.km2. Although, the surface water resource is plentiful its capitalization is facing serious problems due to pollution of various origins, from the one related to former mining activities, to those linked to the existence of human habitats which provides different residues. As for the underground water resource, the relatively impermeable substrate creates poor conditions for reserves accumulation and gives unfavorable chemical properties for accumulated water. Overall, water balance is in surplus with rainfall values nearly double compared to the drainage ones and aridity index values which barely exceed 0.5

    Postero-lateral approach with open view vertebroplasty - ”eggshell” technique

    Get PDF
    Since august 2008 we used in Spine Surgery Department, Emergency Clinical Hospital “Bagdasar-Arseni”, Bucharest, a new technique for the surgical treatment of thoraco-lumbar burst fractures. This technique is based on a postero-lateral approach of the thoraco-lumbar spine, reconstruction of anterior column using cement (PMMA) and stabilization of posterior column using metallic instrumentation uni- or bilateral. The paper presents the technical and biomechanical data of this spinal procedure

    Normal and intruder configurations in Si- 34 populated in the beta(-) decay of Mg-34 and Al-34

    Get PDF
    The structure of Si-34 was studied through gamma spectroscopy separately in the beta(-) decays of Mg-34 and Al-34 at the ISOLDE facility of CERN. Different configurations in Si-34 were populated independently from the two recently identified beta-decaying states in Al-34 having spin-parity assignments J(pi) = 4(-) dominated by the normal configuration pi(d(5/2))(-1) circle times nu(f(7/2)) and J(pi) = 1(+) by the intruder configuration pi(d(5/2))(-1) circle times nu(d(3/2))(-1) (f(7/2))(2). The paper reports on spectroscopic properties of Si-34 such as an extended level scheme, spin and parity assignments based on log(ft) values and gamma-ray branching ratios, absolute beta feeding intensities, and neutron emission probabilities. A total of 11 newly identified levels and 26 transitions were added to the previously known level scheme of Si-34. Large scale shell-model calculations using the SDPF-U-MIX interaction, able to treat higher order intruder configurations, are compared with the new results and conclusions are drawn concerning the predictive power of SDPF-U-MIX, the N = 20 shell gap, the level of mixing between normal and intruder configurations for the 0(1)(+), 0(2)(+), and 2(1)(+) states, and the absence of triaxial deformation in Si-3(4).Peer reviewe

    Network analyses in systems biology: new strategies for dealing with biological complexity

    Get PDF
    The increasing application of network models to interpret biological systems raises a number of important methodological and epistemological questions. What novel insights can network analysis provide in biology? Are network approaches an extension of or in conflict with mechanistic research strategies? When and how can network and mechanistic approaches interact in productive ways? In this paper we address these questions by focusing on how biological networks are represented and analyzed in a diverse class of case studies. Our examples span from the investigation of organizational properties of biological networks using tools from graph theory to the application of dynamical systems theory to understand the behavior of complex biological systems. We show how network approaches support and extend traditional mechanistic strategies but also offer novel strategies for dealing with biological complexity
    corecore