242 research outputs found
Artificial and Natural Radioactivity Measurements and Radiation Dose Assessment in the Vicinity of Ghana Nuclear Research Reactor-1 (GHARR-1)
Radioactivity concentrations of <sup>226</sup>Ra, <sup>232</sup>Th, <sup>40</sup>K and <sup>137</sup>Cs in soil samples and water sources around the Ghana Research Reactor-1 (GHARR-1) and the immediate surroundings have been measured using gamma spectrometry. The primary aim of the study was to establish baseline radioactivity levels in the environs of GHARR-1. The average activity concentration of <sup>226</sup>Ra, <sup>232</sup>Th, <sup>40</sup>K and <sup>137</sup>Cs were 22.3 ± 1.12 Bq kg<sup>-1</sup>, 49.8 ± 1.60Bq kg-1, 99.60 ± 5.81 Bq kg<sup>-1</sup> and 1.48 ± 0.25 Bq kg<sup>-1</sup> for soil and 0.60 ± 0.11 Bq l<sup>-1</sup>, 2.13 ± 0.21 Bq l<sup>-1</sup>, 10.75 ± 0.84 Bq l<sup>-1</sup> and 0.47 ± 0.05 Bq l<sup>-1</sup>for the water, respectively. The <sup>226</sup>Ra and <sup>232</sup>Th concentrations compare quite well with world averages, whilst the <sup>40</sup>K concentration was lower than the world average. The levels of <sup>137</sup>Cs observed in the samples are within the range of ‘background’  concentrations. The estimated average annual effective doses from external exposure to soil and ingestion of water samples were calculated to be 0.06 mSv and 0.53 mSv, respectively. The estimated outdoor  external gamma dose rate measured in air ranged from 20-430 nGy h<sup>-1</sup> with an average value of 100 nGy h<sup>-1</sup>, which is higher than the world average value of 59 nGy h<sup>-1</sup>. In the case of water samples, the average value was higher than the guidance level of 0.1 mSv y<sup>-1</sup>, as recommended by the European Union and the World Health Organization
Molecular screening of Borrelia miyamotoi and Tick-Borne Encephalitis Virus in ixodid ticks in urban green areas in Serbia
Introduction: Zoonotic tick-borne diseases (TBDs) represent an increasing threat in urban areas,
including city parks and green recreational areas. Borrelia miyamotoi is pathogenic to humans but
there is still little information about its circulation in nature and potential local impact on human health, while tick-borne encephalitis virus (TBEV) is endemic in many European countries and sporadic autochthonous cases in humans have been reported in Serbia.
The objective of our study was to determine the prevalence of two emerging zoonotic tick-borne
pathogens (TBPs) − B. miyamotoi and TBEV in urban areas in the city of Belgrade (24 localities),
four localities in Eastern Serbia, one in the province of the Vojvodina.
Methods: At 29 localities, a total of 480 ticks were collected from March to June 2021, and identified to the species level by using morphological keys. DNA and RNA were extracted from individual tick samples, while for molecular detection, probe-based qPCR and nested PCR were applied.Results: Among 480 ticks, 445 were identified as Ixodes ricinus (213 males, 176 females, 56 nymphs), 30 as Dermacentor reticulatus (18 females, 12 males), three Dermacentor marginatus females, one Haemaphysalis concinna female, and one Haemaphysalis punctata male. Using probe-based qPCR, the prevalence of B. miyamotoi in ticks was 1.04% (DNA was detected in five I. ricinus, two females and two males collected from three Belgrade localities and one male from Eastern Serbia), while sequencing was successful in samples of two I. ricinus females collected from two Belgrade localities and one male from Eastern Serbia. TBEV RNA was not detected in any sample. Conclusions: This is the first report on the presence of the emerging zoonotic pathogen B. miyamotoi in I. ricinus ticks in urban green areas in Serbia, indicating the risk of B. miyamotoi disease. Risk areas within cities should be identified and knowledge regarding TBPs and TBDs among the general population in urban areas should be increased
Cultural differences affecting decision-making style: a comparative study between four countries
The aim of this paper was to identify the impact of national culture on decision-making styles in selected countries: Croatia, Slovenia, Bosnia and Herzegovina and Hungary. The estimation of Hofstede’s dimensions of national cultures and comparative analyses was carried out by using a narrow-sample strategy. The estimated positions on each dimension confirmed the Hofstede’s original research ranking. The result with significant value was the confirmation of the global trend of decreasing power distance and significant movement towards the individualism. Besides the standardization procedure of comparative cross-cultural analyses, variance analyses were used to identify cultural differences in decision-making styles related to complex decisions (Janis and Mann’s typology). The proposition is that complex decisions are, above and beyond all others, the consequence of social and cultural values installed in every individual. Statistically significant dependency was identified for hyper-vigilant and vigilant decision-making style and national culture’s dimensions. A beneficial goal was to identify the differences and the similarities in value orientation and those in the decision-making style which should not be mistreated as they may influence future business cooperation and political and economic integrations within the CEE context
Višenukleonska emisija nakon pionske apsorpcije u N, Ar i Xe
Positive pion absorption was studied in an almost 4π geometry allowing simultaneous measurements of various charge and neutral multiplicities. Total absorption cross sections and its decomposition into the most important channels is determined. The results are presented for N, Ar and Xe nuclei at incident pion energies of 118,162 and 239 MeV. The role of multinucleon emission in the absorption process is emphasized.Proučava se pionska apsorpcija s blizu 4π detekcijom koja dozvoljava istovremeno mjerenje raznih nabojskih i neutralnih višestrukosti. Određuju se ukupni udarni presjeci i njihovo razlaganje u najvažnije kanale. Predstavljaju se rezultati za jezgre N, Ar i Xe na energijama 118,162 i 239 MeV. Ističe se uloga višenukleonske emisije u procesu apsorpcije
Functional Myogenic Engraftment from Mouse iPS Cells
Direct reprogramming of adult fibroblasts to a pluripotent state has opened new possibilities for the generation of patient- and disease-specific stem cells. However the ability of induced pluripotent stem (iPS) cells to generate tissue that mediates functional repair has been demonstrated in very few animal models of disease to date. Here we present the proof of principle that iPS cells may be used effectively for the treatment of muscle disorders. We combine the generation of iPS cells with conditional expression of Pax7, a robust approach to derive myogenic progenitors. Transplantation of Pax7-induced iPS-derived myogenic progenitors into dystrophic mice results in extensive engraftment, which is accompanied by improved contractility of treated muscles. These findings demonstrate the myogenic regenerative potential of iPS cells and provide rationale for their future therapeutic application for muscular dystrophies
A Model for the Roll-Out of Comprehensive Adult Male Circumcision Services in African Low-Income Settings of High HIV Incidence: The ANRS 12126 Bophelo Pele Project
Bertrand Auvert and colleagues describe the large-scale roll-out of adult male circumcision through a program in South Africa
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
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