90 research outputs found

    Renormalization of the weak hadronic current in the nuclear medium

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    The renormalization of the weak charge-changing hadronic current as a function of the reaction energy release is studied at the nucleonic level. We have calculated the average quenching factors for each type of current (vector, axial vector and induced pseudoscalar). The obtained quenching in the axial vector part is, at zero momentum transfer, 19% for the sd shell and 23% in the fp shell. We have extended the calculations also to heavier systems such as 56^{56}Ni and 100^{100}Sn, where we obtain stronger quenchings, 44% and 59%, respectively. Gamow--Teller type transitions are discussed, along with the higher order matrix elements. The quenching factors are constant up to roughly 60 MeV momentum transfer. Therefore the use of energy-independent quenching factors in beta decay is justified. We also found that going beyond the zeroth and first order operators (in inverse nucleon mass) does not give any substantial contribution. The extracted renormalization to the ratio CP/CAC_P/C_A at q=100 MeV is -3.5%, -7.1$%, -28.6%, and +8.7% for mass 16, 40, 56, and 100, respectively.Comment: 28 pages, 6 figure

    Shell-Model Effective Operators for Muon Capture in ^{20}Ne

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    It has been proposed that the discrepancy between the partially-conserved axial-current prediction and the nuclear shell-model calculations of the ratio CP/CAC_P/C_A in the muon-capture reactions can be solved in the case of ^{28}Si by introducing effective transition operators. Recently there has been experimental interest in measuring the needed angular correlations also in ^{20}Ne. Inspired by this, we have performed a shell-model analysis employing effective transition operators in the shell-model formalism for the transition 20Ne(0g.s.+)+Ό−→20F(1+;1.057MeV)+ΜΌ^{20}Ne(0^+_{g.s.})+\mu^- \to ^{20}F(1^+; 1.057 MeV) + \nu_\mu. Comparison of the calculated capture rates with existing data supports the use of effective transition operators. Based on our calculations, as soon as the experimental anisotropy data becomes available, the limits for the ratio CP/CAC_P/ C_A can be extracted.Comment: 9 pages, 3 figures include

    Towards the solution of the CP/CAC_{P}/C_{A} anomaly in shell-model calculations of muon capture

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    Recently many authors have performed shell-model calculations of nuclear matrix elements determining the rates of the ordinary muon capture in light nuclei. These calculations have employed well-tested effective interactions in large scale shell-model studies. For one of the nuclei of interest, namely 28^{28}Si, there exists recent experimental data which can be used to deduce the value of the ratio CP/CAC_{P}/C_{A} by using the calculated matrix elements. Surprisingly enough, all the abovementioned shell-model results suggest a very small value (≃0\simeq 0) for CP/CAC_{P}/C_{A}, quite far from the PCAC prediction and recent data on muon capture in hydrogen. We show that this rather disturbing anomaly is solved by employing effective transition operators. This finding is also very important in studies of the scalar coupling of the weak charged current of leptons and hadrons.Comment: Revtex, 6 pages, 2 figs include

    Sex differences associated with adverse drug reactions resulting in hospital admissions

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    Background Adverse drug events, including adverse drug reactions (ADRs), are responsible for approximately 5% of unplanned hospital admissions: a major health concern. Women are 1.5-1.7 times more likely to develop ADRs. The main objective was to identify sex differences in the types and number of ADRs leading to hospital admission. Methods ADR-related hospital admissions between 2005 and 2017 were identified from the PHARMO Database Network using hospital discharge diagnoses. Patients aged >= 16 years with a drug possibly responsible for the ADR and dispensed within 3 months before admission were included. Age-adjusted odds ratios (OR) with 95% CIs for drug-ADR combinations for women versus men were calculated. Results A total of 18,469 ADR-related hospital admissions involving women (0.35% of all women admitted) and 14,678 admissions involving men (0.35% of all men admitted) were included. Most substantial differences were seen in ADRs due to anticoagulants and diuretics. Anticoagulants showed a lower risk of admission with persistent haematuria (ORadj 0.31; 95%CI 0.21, 0.45) haemoptysis (ORadj 0.47, 95%CI 0.30,0.74) and subdural haemorrhage (ORadj 0.61; 95%CI 0.42,0.88) in women than in men and a higher risk of rectal bleeding in women (ORadj 1.48; 95%CI 1.04,2.11). Also, there was a higher risk of admission in women using thiazide diuretics causing hypokalaemia (ORadj 3.03; 95%CI 1.58, 5.79) and hyponatraemia (ORadj 3.33, 95%CI 2.31, 4.81) than in men. Conclusions There are sex-related differences in the risk of hospital admission in specific drug-ADR combinations. The most substantial differences were due to anticoagulants and diuretics.Peer reviewe

    Induced pseudoscalar coupling of the proton weak interaction

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    The induced pseudoscalar coupling gpg_p is the least well known of the weak coupling constants of the proton's charged--current interaction. Its size is dictated by chiral symmetry arguments, and its measurement represents an important test of quantum chromodynamics at low energies. During the past decade a large body of new data relevant to the coupling gpg_p has been accumulated. This data includes measurements of radiative and non radiative muon capture on targets ranging from hydrogen and few--nucleon systems to complex nuclei. Herein the authors review the theoretical underpinnings of gpg_p, the experimental studies of gpg_p, and the procedures and uncertainties in extracting the coupling from data. Current puzzles are highlighted and future opportunities are discussed.Comment: 58 pages, Latex, Revtex4, prepared for Reviews of Modern Physic

    Polarization transfer in the 16^{16}O(p,pâ€Č)(p,p') reaction at forward angles and structure of the spin-dipole resonances

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    Cross sections and polarization transfer observables in the 16^{16}O(p,pâ€Č)(p,p') reactions at 392 MeV were measured at several angles between Ξlab=\theta_{lab}= 0∘^\circ and 14∘^\circ. The non-spin-flip (ΔS=0{\Delta}S=0) and spin-flip (ΔS=1{\Delta}S=1) strengths in transitions to several discrete states and broad resonances in 16^{16}O were extracted using a model-independent method. The giant resonances in the energy region of Ex=19−E_x=19-27 MeV were found to be predominantly excited by ΔL=1{\Delta}L=1 transitions. The strength distribution of spin-dipole transitions with ΔS=1{\Delta}S=1 and ΔL=1{\Delta}L=1 were deduced. The obtained distribution was compared with a recent shell model calculation. Experimental results are reasonably explained by distorted-wave impulse approximation calculations with the shell model wave functions.Comment: 28 pages RevTex, including 9 figures, to be published in Phys. Rev. C.; a typo in Eq. (3b) was correcte

    Multifaceted value profiles of forest owner categories in South Sweden: The river helge Ă„ catchment as a case study

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    Forest landscapes provide benefits from a wide range of goods, function and intangible values. But what are different forest owner categories\u27 profiles of economic use and non-use values? This study focuses on the complex forest ownership pattern of the River Helge Ä catchment including the Kristianstad Vattenrike Biosphere Reserve in southern Sweden. We made 89 telephone interviews with informants representing the four main forest owner categories. Our mapping included consumptive and non-consumptive direct use values, indirect use values, and non-use values such as natural and cultural heritage. While the value profiles of non-industrial forest land owners and municipalities included all value categories, the forest companies focused on wood production, and the Swedish Environmental Protection Agency on nature protection. We discuss the challenges of communicating different forest owners\u27 economic value profiles among stakeholders, the need for a broader suite of forest management systems, and fora for collaborative planning. © 2013 The Author(s)

    Contemporary radiation doses in interventional cardiology: a nationwide study of patient doses in Finland

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    The amount of interventional procedures such as percutaneous coronary intervention (PCI), transcatheter aortic valve implantation (TAVI), pacemaker implantation (PI) and ablations has increased within the previous decade. Simultaneously, novel fluoroscopy mainframes enable lower radiation doses for patients and operators. Therefore, there is a need to update the existing diagnostic reference levels (DRLs) and propose new ones for common or recently introduced procedures. We sought to assess patient radiation doses in interventional cardiology in a large sample from seven hospitals across Finland between 2014 and 2016. Data were used to set updated national DRLs for coronary angiographies (kerma-air product (KAP) 30 Gycm2) and PCIs (KAP 75 cm2), and novel levels for PIs (KAP 3.5 Gycm2), atrial fibrillation ablation procedures (KAP 25 Gycm2) and TAVI (KAP 90 Gycm2). Tentative KAP values were set for implantations of cardiac resynchronization therapy devices (CRT, KAP 22 Gycm2), electrophysiological treatment of atrioventricular nodal re-entry tachycardia (6 Gycm2) and atrial flutter procedures (KAP 16 Gycm2). The values for TAVI and CRT device implantation are published for the first time on national level. Dose from image acquisition (cine) constitutes the major part of the total dose in coronary and atrial fibrillation ablation procedures. For TAVI, patient weight is a good predictor of patient dose.</p

    Climate and colonialism

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    Recent years have seen a growth in scholarship on the intertwined histories of climate, science and European imperialism. Scholarship has focused both on how the material realities of climate shaped colonial enterprises, and on how ideas about climate informed imperial ideologies. Historians have shown how European expansion was justified by its protagonists with theories of racial superiority, which were often closely tied to ideas of climatic determinism. Meanwhile, the colonial spaces established by European powers offered novel ‘laboratories’ where ideas about acclimatisation and climatic improvement could be tested on the ground. While historical scholarship has focused on how powerful ideas of climate informed imperial projects, emerging scholarship in environmental history, history of science and historical geography focuses instead on the material and cognitive practices by which the climates of colonial spaces were made known and dealt with in fields such as forestry, agriculture and human health. These heretofore rather disparate areas of historical research carry great contemporary relevance of studies of how climates and their changes have been understood, debated and adapted to in the past

    EMN for radiation protection - an evolving European metrology network

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    The European Council DIRECTIVE 2013/59/EURATOM laying down the basic safety standards for protection against the dangers arising from exposure to ionizing radiation is currently the main European regulation on ionizing radiation. The practical implementation of the European basic safety standards has become more complex due to the lack of consideration of the metrological implications and the adaptation to new technological developments, which lead to new standards, technological innovations, and improved capabilities. It was considered by EURAMET to be of a vital importance to have a metrology network that acts as a focal point between the metrology communities and the relevant radiation protection stakeholders, including regulators, standardization bodies, manufacturers, users of radiation sources and international organizations and radiation protection platforms. One of the most important tasks of this European Metrology Network (EMN) for Radiation Protection is to give a strong voice to the field of radiation protection metrology in Europe, so that it can provide responsible guidance and support to future technological developments. Additionally, metrological competence and capacity are essential to determine ambient or occupational exposures and urgent metrological needs exist in case of emergency situations. The EMN for Radiation Protection is in operation since 2021. The first Chair, Annette Röttger (PTB, Germany), Vice-Chair, Teemu Siiskonen (STUK, Finland) and Secretary Behnam Khanbabaee (PTB, Germany) have been elected. At the second meeting in 2022, first actions have been identified. In this contribution, the planned actions and next steps will be presented.ERPW 2022 - European Radiation Protection Week, 9-14th October 2022, Estoril, Portuga
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