background: poor hygiene will provide good condition for corneal infections by opportunistic free-living amoebae (fla) in soft contact lens wearers. in the present study an amoebic keratitis due to hartmannella has been recognized in a 22-year-old girl with a history of improper soft contact lens use. she had unilateral keratitis on her left eye. her clinical signs were eye pain, redness, blurr...

objective(s) extracellular matrix (ecm) and basement membrane (bm) play important roles in many developmental processes during development and after birth. among the components of the bm, collagen fibers specially type iv are the most important parts. the aim of this study was to determine the time when collagen type iv appears in the bm of lens structure during mouse embryonic development. mat...

purpose : to evaluate distance and near contrast sensitivity (cs) under photopic and mesopic conditions before and after refractive lens exchange (rle) and implantation of the aspheric acrysof restor (sn6ad3 model) intraocular lens (iol) methods : sixty eyes of 30 consecutive patients after rle underwent bilateral implantation with the aspheric acrysof restor iol. the patients sample was divide...

conclusions in cases of unusual vascular lesions, metabolic diseases must be considered. in homocystinuria, early diagnosis and treatment are important. blood homocysteine levels can be returned to normal, and some complications can be prevented. introduction homocystinuria is a hereditary disease caused by a defect in the enzymes involved in metabolizing methionine. homocystinuria can influenc...

introduction: consumption of morphine, during pregnancy, in addition to inducing defects in the mother’s nervous system function, caused defects or delays in the formation and evolution of embryonic visual system. in the present study, changes in lens development were assessed in embryos exposed to morphine in utero. methods: female wistar rats (250-300 g) were mated with male rats and pregnanc...

The aim of this study was to report a new cause of cataract, namely snake bite induced cataract in a dog. A 3-year-old male mongrel dog was referred to our clinic for the assessment of cataract in both eyes. The dog was bitten by a snake nearly 4 months ago. A 40 dioptre acrylic lens with 13 mm haptics was implanted into the lens capsule. In the left eye, posterior synechia was detected in the ...

We report results from the first causal test of the knowledge burden hypothesis, one of several theories advanced to explain increasing team sizes in science. For identification, we exploit the collapse of the USSR as an exogenous shock to the knowledge frontier causing a sudden release of previously hidden research. We report evidence that team size increased disproportionately in Soviet-rich ...

Introduction International Commission on Radiological Protection (ICRP) has provided a comprehensive discussion on threshold dose for radiation-induced cataract in ICRP publication 116. Accordingly, various parts of the eye lens have different radio-sensitivities. Recently, some studies have been performed to develop a realistic eye model with the aim of providing accurate estimation of fluence...

This paper identifies a key cause for the documented diversification discount, namely diversified firms being traded at a discount relative to focused firms. We attribute such empirical findings to different distributions of diversified firms vis-à-vis focused firms over leverage in the data sample. We replicate Lang and Stulz’s (1994) and Berger and Ofek’s (1995) main results using a sample fr...