abstract research and development (r&d;) spending plays a major role in innovation, raising productivity and increasing economic growth. the purpose of this paper is to investigate the impact of r&d; spending on growth and total factor productivity (tfp) in iran's agricultural sector. we estimate growth and productivity models using auto-regressive distributed lag (ardl) approach and data over ...

purpose: to compare the effects of short-tem and long-term systemic corticosteroids in the treatment of confirmed ocular toxoplasmosis. methods: this randomized comparative clinical trial was performed on 69 patients with confirmed active ocular toxoplasmosis with typical clinical manifestations. the subjects were randomly assigned to receive either 10 days (group a, 33 cases) or 4-6 weeks (gro...

Water erosion causes reduced farmland productivity, and with a longer period of cultivation, agricultural productivity becomes increasingly vulnerable. The vulnerability of farmland productivity needs assessment due to long-term water erosion. The key to quantitative assessment is to propose a quantitative method with water loss scenarios to calculate productivity losses due to long-term water ...

Abstract This paper analyses quarterly estimates of productivity growth at industry level for three advanced economies, France, the UK and US, 2020. We use detailed industry-level data to distinguish reallocations working hours between industries from pure within-industry gains or losses. find that all countries showed positive rates aggregate output per hour in 2020 over 2019. However, after r...

background: this study aims to investigate the patterns of bioaccumulation and depuration of copper in the selected kidney and liver of capoeta fusca. methods: the fish were collected between september and november 2010 from a qanat in birjand. they were exposed to two types treatments with copper (0.25 and 0.75 mg/l) for a period of 41 days. the fish under study were exposed to the above-menti...

objective: successful bonding of a dental implant to bone, which was referred to as osseointegration by branemark has been well documented. however, long-term prognosis of an implant depends on adequate maintenance and long-term care. an effective maintenance program is required to preserve the health of peri-implant tissues. several techniques have been suggested for this purpose but it is not...