Folding model study of the charge-exchange scattering to the isobaric analog state and implication for the nuclear symmetry energy

The Fermi transition (\Delta L=\Delta S=0 and \Delta T=1) between the nuclear isobaric analog states (IAS), induced by the charge-exchange (p,n) or (3He,t) reaction, can be considered as "elastic" scattering of proton or 3He by the isovector term of the optical potential (OP) that flips the projectile isospin. The accurately measured (p,n) or (3He,t) scattering cross-section to the IAS can be used, therefore, to probe the isospin dependence of the proton or 3He optical potential. Within the folding model, the isovector part of the OP is determined exclusively by the neutron-proton difference in the nuclear densities and the isospin dependence of the effective nucleon-nucleon (NN) interaction. Because the isovector coupling explicitly links the isovector part of the proton or 3He optical potential to the cross section of the charge-exchange (p,n) or (3He,t) scattering to the IAS, the isospin dependence of the effective (in-medium) NN interaction can be well tested in the folding model analysis of these charge-exchange reactions. On the other hand, the same isospin- and density dependent NN interaction can also be used in a Hartree-Fock calculation of asymmetric nuclear matter, to estimate the nuclear matter energy and its asymmetry part (the nuclear symmetry energy). As a result, the fine-tuning of the isospin dependence of the effective NN interaction against the measured (p,n) or (3He,t) cross sections should allow us to make some realistic prediction of the nuclear symmetry energy and its density dependence.Comment: Accepted for publication in European Physical Journal A - "Hadrons and Nuclei

Availability of Free-Space Laser Communication Link with the Presence of Clouds in Tropical Regions

Free-space laser communication (lasercom), a great application of using free-space optics (FSO) for satellite communication, has been gaining significant attraction. However, despite of great potential of lasercom, its performance is limited by the adverse effects of atmospheric turbulence and cloud attenuation, which directly affect the quality and availability of lasercom links. The paper, therefore, concentrates on evaluating the cloud attenuation in the FSO downlinks between satellite and ground stations in tropical regions. The meteorological ERA-Interim database provided by the European Center for Medium-Range Weather Forecast (ECMWF) from 2015 to 2020 is used to get the cloud database in several areas in tropical regions. This study proposed a novel probability density function of cloud attenuation, which is validated by using a well-known curve-fitting method. Moreover, we derive a closed-form of satellite-based FSO link availability by applying the site diversity technique to improve the system performance. Numerical results, which demonstrate the urgency of the paper, reveal that the impact of clouds on tropical regions is more severe than in temperate regions

Do the internet, economic growth, and environmental quality spur people's happiness during Covid-19 pandemic?

Factors affecting people's happiness have attracted much attention in the context of the COVID-19 pandemic. This paper was conducted to investigate whether internet use, economic growth, and environmental quality improvements can ease psychological darns caused by the COVID-19 pandemic. In the context of Southeast countries, and by applying the Bayesian inference, the findings of this study are summarized: (i) internet use and economic growth positively drive people's happiness; (ii) the effect of environmental quality on happiness is unclear in the context of the COVID-19 pandemic. Based on this evidence, the study suggests practical implications for policymakers in boosting economic growth and enhancing people's happiness

Foreign direct investment in Vietnam: Is there any evidence of technological spillover effects

In the context of integrating more deeply into the world economy the Vietnamese policy makers have undertaken several measures to attract foreign direct investment to the country, with the culmination of FDI inflows in 2007 reaching over USD 20 billion, an increase of 69% over 2006. The policy has been taken on the ground that the FDI inflows will create employment and bring along the much needed technological advances, which will spill over to domestic firms. In this paper, we use a firm-level panel data constructed from the Census 2000-2005 to investigate not only the horizontal spillovers but also the backward and forward linkages. Adding to the current literature which focused mainly on the spillovers in the manufacturing sector, our paper provide the first estimates of the spillover effects in the service sector (at least in the context of developing countries). We also distinguish between the horizontal output spillovers (which capture demonstration effects and competition effects) and the horizontal employment spillover (which captures the labour mobility effect). The results obtained from our regression models are mixed. Different channels of spillovers are at work for the manufacturing and the service sectors. We find evidence of the positive backward technological spillovers for the manufacturing and positive horizontal spillovers for the service sector

Foreign direct investment in Vietnam: Is there any evidence of technological spillover effects

In the context of integrating more deeply into the world economy the Vietnamese policy makers have undertaken several measures to attract foreign direct investment to the country, with the culmination of FDI inflows in 2007 reaching over USD 20 billion, an increase of 69% over 2006. The policy has been taken on the ground that the FDI inflows will create employment and bring along the much needed technological advances, which will spill over to domestic firms. In this paper, we use a firm-level panel data constructed from the Census 2000-2005 to investigate not only the horizontal spillovers but also the backward and forward linkages. Adding to the current literature which focused mainly on the spillovers in the manufacturing sector, our paper provide the first estimates of the spillover effects in the service sector (at least in the context of developing countries). We also distinguish between the horizontal output spillovers (which capture demonstration effects and competition effects) and the horizontal employment spillover (which captures the labour mobility effect). The results obtained from our regression models are mixed. Different channels of spillovers are at work for the manufacturing and the service sectors. We find evidence of the positive backward technological spillovers for the manufacturing and positive horizontal spillovers for the service sector

Class based Influence Functions for Error Detection

Influence functions (IFs) are a powerful tool for detecting anomalous examples in large scale datasets. However, they are unstable when applied to deep networks. In this paper, we provide an explanation for the instability of IFs and develop a solution to this problem. We show that IFs are unreliable when the two data points belong to two different classes. Our solution leverages class information to improve the stability of IFs. Extensive experiments show that our modification significantly improves the performance and stability of IFs while incurring no additional computational cost.Comment: Thang Nguyen-Duc, Hoang Thanh-Tung, and Quan Hung Tran are co-first authors of this paper. 12 pages, 12 figures. Accepted to ACL 202

The Temperature-sensitivity of a Critical Electric Field Induced Magnetic Easy-axis Reorientation Ferromagnetic/ferroelectric Layered Heterostructures

We have investigated the effects of temperature on the magnetic easy axis reorientation (EARs) in polycrystalline ferromagnetic (FM) nano-scale thin films, i.e. (001)-oriented cubic films such as Fe, Ni, CFO and (0001)-oriented hexagonal films such as Co, grown on ferroelectric (FE) substrates, for example PZT, BTO substrates. The model of FM/FE bilayered heterostructures has been applied to study the total free energy of the FM films. By minimizing this energy, we have shown that temperature has a significant effect on a critical electric field induced magnetic reorientation

Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke