7,043 research outputs found
Innovation Through Protection: Does Safeguard Protection Increase Investment in R and D?
We perform the first empirical study to focus on the relationship between trade protection and investment in Research and Development. Our results support predictions from the theoretical literature that temporary tariffs stimulate research and development, although we find no evidence that this effect diminishes as the termination of protection approaches as predicted by some theoretical models. We also find little evidence that quotas reduce research and development as predicted by multiple theoretical works. Finally, our results indicate that temporary tariffs result in decreased capital investment, perhaps because firms use periods of temporary protection to shutdown unprofitable facilities. This reveals an important distinction in firm behavior with regard to investment in tangible versus intangible capital during periods of trade protection.Research and Development, Strategic Protection
Measurement of the electron's electric dipole moment using YbF molecules: methods and data analysis
We recently reported a new measurement of the electron's electric dipole
moment using YbF molecules [Nature 473, 493 (2011)]. Here, we give a more
detailed description of the methods used to make this measurement, along with a
fuller analysis of the data. We show how our methods isolate the electric
dipole moment from imperfections in the experiment that might mimic it. We
describe the systematic errors that we discovered, and the small corrections
that we made to account for these. By making a set of additional measurements
with greatly exaggerated experimental imperfections, we find upper bounds on
possible uncorrected systematic errors which we use to determine the systematic
uncertainty in the measurement. We also calculate the size of some systematic
effects that have been important in previous electric dipole moment
measurements, such as the motional magnetic field effect and the geometric
phase, and show them to be negligibly small in the present experiment. Our
result is consistent with an electric dipole moment of zero, so we provide
upper bounds to its size at various confidence levels. Finally, we review the
prospects for future improvements in the precision of the experiment.Comment: 35 pages, 15 figure
The Role of the Dominant Modes of Precipitation Variability over Eastern Africa in Modulating the Hydrology of Lake Victoria
Previous water budget studies over Lake Victoria basin have shown that there is near balance between rainfall and evaporation and that the variability of Lake Victoria levels is determined virtually entirely by changes in rainfall since evaporation is nearly constant. The variability of rainfall over East Africa is dominated by El Niño-Southern Oscillation (ENSO); however, the second and third most dominant rainfall climate modes also account for significant variability across the region. The relationship between ENSO and other significant modes of precipitation variability with Lake Victoria levels is nonlinear. This relationship should be studied to determine which modes need to be accurately modeled in order to accurately model Lake Victoria levels, which are important to the hydroelectric industry in East Africa. The objective of this analysis is to estimate the relative contributions of the dominant modes of annual precipitation variability to the modulation of Lake Victoria levels for the present day (1950â2012). The first mode of annual rainfall variability accounts for most of the variability in Lake Victoria levels, while the effects of the second and third modes are negligible even though these modes are also significant over the region
Effects of certain disinfectants and antibiotics on biofilm formation by Staphylococcus aureus isolated from medical devices at the University Hospital Center of Sidi Bel Abbes, Algeria
Background: Staphylococcus aureus is one of the species of bacteria most frequently isolated from medical devices. The ability to produce biofilm is an important step in the pathogenesis of these staphylococci infection, and biofilm formation is strongly dependent on environmental conditions as well as antibiotics and disinfectants used in the treatment and prevention of infections.Methodology: In this study, 28 S. aureus isolated from medical devices at the University Hospital Center of Sidi Bel Abbes in Northwestern Algeria were tested for biofilm formation by culture on Red Congo Agar (RCA). The tube method (TM) and tissue culture plate (TCP) techniques were also used to investigate the effect of penicillin, ethanol and betadine on pre-formed biofilm.Results: Nineteen S. aureus isolates produced biofilm on the RCA and 7 produced biofilms by the tube method, 2 of which were high producer. In addition, 9 S. aureus isolates produced biofilm on polystyrene micro-plates, and in the presence of penicillin and ethanol, this number increased to 19 and 11 biofilm producing S. aureus isolates respectively. On the other hand, no biofilm was formed in the presence of betadine.Conclusion: It is important to test for biofilm formation following an imposed external constraint such as disinfectants and antibiotics in order to develop new strategies to combat bacterial biofilms but also to better control their formation.
Keywords : Staphylococcus aureus, biofilm, medical device, disinfectant, antibiotic
French Title: Effets de certains désinfectants et antibiotiques sur la formation de biofilms par Staphylococcus aureus isolé à partir de dispositifs médicaux au Centre Hospitalier Universitaire de Sidi Bel AbbÚs, Algérie
Contexte: Staphylococcus aureus est l'une des espÚces de bactéries les plus fréquemment isolées des dispositifs médicaux. La capacité de produire du biofilm est une étape importante dans la pathogenÚse de ces infections à staphylocoques, et la formation de biofilm dépend fortement des conditions environnementales ainsi que des antibiotiques et des désinfectants utilisés dans le traitement et la prévention des infections.
Méthodologie: Dans cette étude, 28 S. aureus isolés à partir de dispositifs médicaux au Centre hospitalier universitaire de Sidi Bel AbbÚs dans le nord-ouest de l'Algérie ont été testés pour la formation de biofilm par culture sur gélose rouge du Congo (RCA). La méthode des tubes (TM) et les techniques de plaques de culture tissulaire (TCP) ont également été utilisées pour étudier l'effet de la pénicilline, de l'éthanol et de la bétadine sur le biofilm préformé.
Résultats: Dix-neuf isolats de S. aureus ont produit un biofilm sur le RCA et 7 ont produit des biofilms par la méthode des tubes, dont 2 étaient trÚs productifs. De plus, 9 isolats de S. aureus ont produit du biofilm sur des microplaques en polystyrÚne, et en présence de pénicilline et d'éthanol, ce nombre est passé à 19 et 11 isolats de S. aureus producteurs de biofilm respectivement. En revanche, aucun biofilm ne s'est formé en présence de bétadine.
Conclusion: Il est important de tester la formation de biofilm suite à une contrainte externe imposée comme les désinfectants et les antibiotiques afin de développer de nouvelles stratégies pour lutter contre les biofilms bactériens mais aussi pour mieux contrÎler leur formation.
Mots-clés: Staphylococcus aureus, biofilm, dispositif médical, désinfectant, antibiotique
 
SOCIETYâS EMPOWERMENT THROUGH THE UTILIZATION OF PRODUCTIVE ZAKAT AT DOMPET DHUAFA AMIL ZAKAT INSTITUTION OF SOUTH SULAWESI
The main problem of this research is how to empower society through utilizing productive zakat at the Dompet Dhuafa Amil Zakat institution of South Sulawesi. This study classifies the main issue into three problems: (1) What is productive zakat utilization in the Dompet Dhuafa Amil Zakat institution of South Sulawesi? (2) What factors influence society empowerment through utilizing productive zakat in Dompet Dhuafa Amil Zakat institution of South Sulawesi? And (3) The impact of the utilization of productive zakat at Dompet Dhuafa Amil Zakat institution of South Sulawesi on Society Empowerment. The approach used in this study was qualitative descriptive in terms of Case study. The results of this study were; First, the form of productive zakat utilization carried out by Dompet Dhuafa Amil Zakat institution of South Sulawesi, namely 1). Surplus Zakat Budget; refers to Amilâs zakat funds as companiesâ funding by making mustahik zakat as workers. 2) In-Kind; refers to zakat funds given in the form of production tools used by mustahik to run a productive business. 3). Revolving Fund; it refers to the utilization of zakat by providing loan funds to mustahik in the form of qardhul hasan or benevolent loans.The main problem of this research is how to empower society through utilizing productive zakat at the Dompet Dhuafa Amil Zakat institution of South Sulawesi. This study classifies the main issue into three problems: (1) What is productive zakat utilization in the Dompet Dhuafa Amil Zakat institution of South Sulawesi? (2) What factors influence society empowerment through utilizing productive zakat in Dompet Dhuafa Amil Zakat institution of South Sulawesi? And (3) The impact of the utilization of productive zakat at Dompet Dhuafa Amil Zakat institution of South Sulawesi on Society Empowerment. The approach used in this study was qualitative descriptive in terms of Case study. The results of this study were; First, the form of productive zakat utilization carried out by Dompet Dhuafa Amil Zakat institution of South Sulawesi, namely 1). Surplus Zakat Budget; refers to Amilâs zakat funds as companiesâ funding by making mustahik zakat as workers. 2) In-Kind; refers to zakat funds given in the form of production tools used by mustahik to run a productive business. 3). Revolving Fund; it refers to the utilization of zakat by providing loan funds to mustahik in the form of qardhul hasan or benevolent loans
Pulsed beams as field probes for precision measurement
We describe a technique for mapping the spatial variation of static electric,
static magnetic, and rf magnetic fields using a pulsed atomic or molecular
beam. The method is demonstrated using a beam designed to measure the electric
dipole moment of the electron. We present maps of the interaction region,
showing sensitivity to (i) electric field variation of 1.5 V/cm at 3.3 kV/cm
with a spatial resolution of 15 mm; (ii) magnetic field variation of 5 nT with
25 mm resolution; (iii) radio-frequency magnetic field amplitude with 15 mm
resolution. This new diagnostic technique is very powerful in the context of
high-precision atomic and molecular physics experiments, where pulsed beams
have not hitherto found widespread application.Comment: 6 pages, 12 figures. Figures heavily compressed to comply with
arxiv's antediluvian file-size polic
First report of Barley Yellow Dwarf Viruses (BYDVs) on dicotyledonous weed hosts in Turkey
Yellow dwarf viruses (YDVs) are economically destructive viral diseases of cereal crops, which cause the reduction of harvested yield and quality of grains. Up to now the identification of such viruses was limited to monocotyledonous Poaceae weed hosts, and was not investigated in dicotyledons. In this study, using DAS-ELISA and RT-PCR methods, 6 dicotyledonous weed species, collected from Trakya, Turkey, were examined for the presence of the YDVs pathogens BYDV-PAV, BYDV-MAV, BYDV-RMV, BYDV-SGV and CYDV-RPV. The screening tests revealed certain samples of Geranium dissectum L. and Juncus compressus Jacq. were infected with BYDV-PAV, while other samples of the same species were positive for BYDV-MAV. Additionally, RT-PCR tests of both weed species revealed cases of mixed infection by BYDV-PAV and BYDV-MAV. Transmission experiments using the aphid species Rhopalosiphum padi L. showed that BYDV-PAV was transmitted persistently from Geranium dissectum to barley cv. Barbaros seedlings. To our knowledge, this is the first report of Geranium dissectum and Juncus compressus as possible plant hosts of BYDV-PAV and BYDV-MAV in Turkey
1.90-1.88Ga arc magmatism of central Fennoscandia: geochemistry, U-Pb geochronology, Sm-Nd and Lu-Hf isotope systematics of plutonic-volcanic rocks from southern Finland
The earliest Svecofennian magmatism in southern Finland has been dated at 1.90-1.88Ga. As an example of this, the OrijĂ€rvi (ca. 1.89Ga) and Enklinge (ca. 1.88Ga) volcanic centres comprise bimodal plutonic batholiths surrounded by volcanic rocks of comparable ages and chemical compositions. Here, we report geochemical and Sm-Nd isotope data from intrusive and extrusive samples, combined with zircon U-Pb and Lu-Hf isotopes for granodiorites from both study areas. The samples range from gabbros to granites and indicate a subduction-related continental margin setting. The zircons from the OrijĂ€rvi granodiorite define an age of 1892±4Ma whereas the Enklinge granodiorite yields an age of 1882±6Ma. Several inherited ages of 2.25-1.95Ga as well as younger ages of 1.86-1.80Ga were found in the Enklinge granodiorite. The initial ΔNd values from the mafic rocks from both locations fall in the range +1.1 to +2.9 whereas the felsic rocks exhibit initial ΔNd values of -0.4 to +1.2. The magmatic zircons from the OrijĂ€rvi and Enklinge granodiorites show average initial ΔHf values of -1.1 (at 1892Ma) and zero (at 1882Ma), respectively, each with a spread of about 7 Δ-units. The initial ΔHf values for the inherited zircons from Enklinge range from +3.5 to +7.6 with increasing age. The Sm-Nd data indicate that the mafic rocks were derived from a âmildly depletedâ mantle source while the felsic rocks show larger crustal contribution. Also, the variation in ΔHf values indicates minor mixing between mildly depleted mantle derived magmas and crustal sources. U-Pb ages and Hf isotopes for inherited zircons in the Enklinge granodiorite suggest the presence of juvenile Svecofennian âproto-crustâ at depth
Composition and variations of the fish assemblage of Posidonia oceanica (L.) Delile, seagrass meadows in Annaba bay (Algeria)
During an annual cycle (July 2004 - June 2005), two coastal sites, one far away from anthropic action (site A : AĂŻn Achir) and the other subjected to immediate discharge of waste water (site B : la Caroube), were sampled during the
day (8 h -18 h) and by night (19 h - 7 h), with a net (50 m long, 2 m high) located at a depth of -5 m. According to the frequency of fish species captured, their ecological status was determined. The Shannon-Weaver diversity index (Hâ) was calculated to better understand the structure and
organization of fish assemblages in both sites. In site A, 19 species belonging to 8 families were fished during the day. At night, the fish assemblage was represented by 15 species and 9 families. The family Sparidae was the most diversified, followed by Labridae and Serranidae. Labridae
were the most numerous family by day and by night. Numbers of species and individuals collected in site B during the day (16) as well as by night (11) were significantly lower than those of site A. During daytime, diversity (Hâ) and equitability (R) indices were respectively 2.51 and 0.33 in
site A and of 2.87 and 0.43 in site B. At night, diversity index was lower (site A : 0.64 and site B : 2.55) and equitability was close to 0.41 in the two sitesAu cours d'un cycle annuel (juillet 2004 - juin 2005), deux sites cÎtiers, l'un éloigné de l'action anthropique (site A: Aïn-Achir) et l'autre recevant les rejets directs des eaux usées de la ville d'Annaba (site B: la Caroube),
ont été échantillonnés de jour et de nuit à l'aide d'un filet trémail. En fonction de sa fréquence, le statut écologique de chaque espÚce a été déterminé. L'indice de diversité biologique de Shannon-Weaver (H') a été calculé pour mieux comprendre la structure et l'organisation du peuplement
de poissons dans les deux sites. Dans le site A, 19 espĂšces appartenant Ă 8 familles ont Ă©tĂ© pĂȘchĂ©es de jour. La nuit, le peuplement ichtyologique est reprĂ©sentĂ© par 15 espĂšces et 9 familles. La famille des SparidĂ©s est la plus diversifiĂ©e, suivie de celle des LabridĂ©s et des SerranidĂ©s. Les
Labridés sont les mieux représentés numériquement, aussi bien de jour que de nuit. Dans le site B, les nombres d'espÚces et d'individus capturés, aussi bien de jour (16 espÚces) que de nuit (11 espÚces), sont nettement inférieurs à ceux obtenus dans le site A. De jour, les indices de
diversité (H') et d'équitabilité (R) sont respectivement de 2,51 et de 0,33 dans le site A et de 2,87 et de 0,43 dans le site B. La nuit, l'indice de diversité est plus faible (site A: 0,64 ; site B: 2,55) et l'équitabilité est proche de 0,41 dans les deux sites
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