1,542 research outputs found
Multidrug-resistant Streptococcus pneumoniae in Poland: identification of emerging clones
Penicillin resistance among Streptococcus pneumoniae isolates has rapidly
emerged in Poland during the last decade and has reached prevalence levels
of up to 14.4% in 1997. In order to investigate the nature of this
increase, a molecular epidemiological analysis of
non-penicillin-susceptible multidrug-resistant pneumococci isolated in
1995 and 1996 was conducted. Thirty-seven patients who suffered mainly
from upper respiratory tract infections and pneumococcal pneumonia were
enrolled in this study. The medical centers to which the patients were
admitted were located in 16 Polish towns across the country. Eight
distinct BOX PCR types were observed, representing 14 subtypes.
Restriction fragment end labeling (RFEL) analysis divided the pneumococcal
strains into 16 distinct types. By combining the BOX PCR and RFEL data,
four genetically distinct clusters of strains were identified. Two
clusters represented the genetic clones 23F and 9V, which have recently
emerged all over the world. The two other genetic clusters, which
represented serotypes 23F and 6B, clearly predominated in the analyzed
collection of Polish non-penicillin-susceptible pneumococcal strains.
Since the latter clusters did not match any of the 133 RFEL types of
non-penicillin-susceptible pneumococci collected in 15 other countries,
their Polish clonal origin is most likely
Future scenarios modeling of urban stormwater management response to impacts of climate change and urbanization
Future scenario modeling was used to investigate the effectiveness of urban stormwater infrastructure and its response to potential future changes. The changes of urban stormwater, both in-flow quantity and water quality, in response to climate change and urbanization were examined and tested in two highly developed urban catchments using the US Environmental Protection Agency’s Storm Water
Management Model. Similar responses were observed in the two catchments, despite their differences in size and land use. Flow quantity and water quality appeared to be more sensitive to urbanization factors than to climatic change. With respect to factors attributable to urbanization, urban
intensification (land use plus population density) had more of an effect than land-use changes alone. Low-impact development, as a key adaptation measure, could be effective in mitigating the adverse impacts of future changes on urban stormwater. The methodology developed in this study may be useful for urban stormwater planning and testing such plans against future urbanization and climate change scenarios
Security, Local Community, and the Democratic Political Culture in Africa
In this study, the idea of the local African community as a social structure ensuring the security of its members is presented. An understanding of the concept of security is first briefly discussed, followed by the meaning of the concept of the local African community. The chapter also makes an a priori distinction between what one can call “moderate” and “radical” types of communal life and two case studies exemplifying them are presented. The chapter aims to analyze the trade off, in terms of provision of security, including economic security, by local communities, for the shaping of a democratic political culture in Sub-Saharan Africa. Most importantly, however, this chapter also highlights the rationality that underpins the seemingly low-quality democratic political activities of members of local African communities
Recommended from our members
Antibodies to Conserved Pneumococcal Antigens Correlate with, but Are Not Required for, Protection against Pneumococcal Colonization Induced by Prior Exposure in a Mouse Model
In mice following intranasal exposure to Streptococcus pneumoniae, protection against pneumococcal colonization was independent of antibody but dependent on CD4+ T cells. Nonetheless, concentrations of antibodies to three conserved pneumococcal antigens correlated with protection against colonization. Concentrations of antibodies to conserved pneumococcal antigens may be correlates of protection without being effectors of protection
Improving the quality of set yoghurt using milk fat globule membrane fragments
Lacprodan PL20, a dairy ingredient that is rich in protein and polar lipids, was added into set yoghurts produced from nonhomogenized raw milk. The set yoghurts were prepared using concentrations of 2%, 4%, and 6% Lacprodan PL20, while the control sample was only supplemented with skim milk powder. The effect of Lacprodan PL20 concentrations on the physical and chemical properties, rheology, and microstructure of set yoghurt was thoroughly investigated to determine some likely improvement or changes in quality. Consequently, Lacprodan PL20 showed a gradual improvement in the set yoghurt nutritive values, water holding capacity, and apparent viscosity. The results indicated that the firmness of set yoghurt was altered which steadily improved the gel strength, especially at 4% and 6% concentrations. The fermentation process was slightly delayed at 4% and 6% concentrations and pH values were raised as Lacprodan PL20 concentration increased. The microstructures of the set yoghurts produced with Lacprodan PL20, as examined by scanning electron microscopy, revealed compacted structures with fewer and smaller holes in the gel matrices. Also, a slight color change was observed in set yoghurt using a colorimeter. These results vividly showed that Lacprodan PL20, an enriched milk fat globule membrane fragment, has the potential to improve set yoghurt quality by reducing some defects associated with set yoghurt, such as low gel strength, low dry solids, and the likes
Yield scaling, size hierarchy and fluctuations of observables in fragmentation of excited heavy nuclei
Multifragmentation properties measured with INDRA are studied for single
sources produced in Xe+Sn reactions in the incident energy range 32-50 A MeV
and quasiprojectiles from Au+Au collisions at 80 A MeV. A comparison for both
types of sources is presented concerning Fisher scaling, Zipf law, fragment
size and fluctuation observables. A Fisher scaling is observed for all the
data. The pseudo-critical energies extracted from the Fisher scaling are
consistent between Xe+Sn central collisions and Au quasi-projectiles. In the
latter case it also corresponds to the energy region at which fluctuations are
maximal. The critical energies deduced from the Zipf analysis are higher than
those from the Fisher analysis.Comment: 30 pages, accepted for publication in Nuclear Physics A, references
correcte
Semiclassical theory of shot noise in ballistic n+-i-n+ semiconductor strucutres: relevance of Pauli and long range Coulomb correlations
We work out a semiclassical theory of shot noise in ballistic n+-i-n+
semiconductor structures aiming at studying two fundamental physical
correlations coming from Pauli exclusion principle and long range Coulomb
interaction. The theory provides a unifying scheme which, in addition to the
current-voltage characteristics, describes the suppression of shot noise due to
Pauli and Coulomb correlations in the whole range of system parameters and
applied bias. The whole scenario is summarized by a phase diagram in the plane
of two dimensionless variables related to the sample length and contact
chemical potential. Here different regions of physical interest can be
identified where only Coulomb or only Pauli correlations are active, or where
both are present with different relevance. The predictions of the theory are
proven to be fully corroborated by Monte Carlo simulations.Comment: 15 pages, 11 figures. Title changed and Introduction rewritten.
Accepted for publication in Physical Review
Recommended from our members
The Building Design Advisor
The Building Design Advisor (BDA) is a software environment that supports the integrated use of multiple analysis and visualization tools throughout the building design process, from the initial, schematic design phases to the detailed specification of building components and systems. Based on a comprehensive design theory, the BDA uses an object-oriented representation of the building and its context, and acts as a data manager and process controller to allow building designers to quickly navigate through the multitude of descriptive and performance parameters addressed by the analysis and visualization tools linked to the BDA. Through the Browser the user can edit the values of input parameters and select any number of input and/or output parameters for display in the Decision Desktop. The Desktop allows building designers to compare multiple design alternatives with respect to any number of parameters addressed by the tools linked to the BDA
Pion radii in nonlocal chiral quark model
The electromagnetic radius of the charged pion and the transition radius of
the neutral pion are calculated in the framework of the nonlocal chiral quark
model. It is shown in this model that the contributions of vector mesons to the
pion radii are noticeably suppressed in comparison with a similar contribution
in the local Nambu--Jona-Lasinio model. The form-factor for the process
gamma*pi+pi- is calculated for the -1 GeV^2<q^2<1.6 GeV^2. Our results are in
satisfactory agreement with experimental data.Comment: 7 pages, 7 figure
Search for eta-mesic 4He in the dd->3He n pi0 and dd->3He p pi- reactions with the WASA-at-COSY facility
The search for 4He-eta bound states was performed with the WASA-at-COSY
facility via the measurement of the excitation function for the dd->3He n pi0
and dd->3He p pi- processes. The beam momentum was varied continuously between
2.127 GeV/c and 2.422 GeV/c, corresponding to the excess energy for the dd->4He
eta reaction ranging from Q=-70 MeV to Q=30 MeV. The luminosity was determined
based on the dd->3He n reaction and quasi-free proton-proton scattering via
dd->pp n_spectator n_spectator reactions. The excitation functions determined
independently for the measured reactions do not reveal a structure which could
be interpreted as a narrow mesic nucleus. Therefore, the upper limits of the
total cross sections for the bound state production and decay in
dd->(4He-eta)_bound->3He n pi0 and dd->(4He-eta)_bound->3He p pi- processes
were determined taking into account the isospin relation between both the
channels considered. The results of the analysis depend on the assumptions of
the N* momentum distribution in the anticipated mesic-4He. Assuming as in the
previous works, that this is identical with the distribution of nucleons bound
with 20 MeV in 4He, we determined that (for the mesic bound state width in the
range from 5 MeV to 50 MeV) the upper limits at 90% confidence level are about
3 nb and about 6 nb for npi0 and ppi- channels, respectively. However, based on
the recent theoretical findings of the N*(1535) momentum distribution in the
N*-3He nucleus bound by 3.6 MeV, we find that the WASA-at-COSY detector
acceptance decreases and hence the corresponding upper limits are 5 nb and 10
nb for npi0 and ppi- channels respectively.Comment: This article will be submitted to JHE
- …