The polynomial identity testing problem, or PIT, asks how we can decide if a polynomial is equivalent to zero. A read-once polynomial (ROP) is a polynomial over some field that can be expressed with an arithmetic formula where each variable appears at most once. We construct a deterministic polynomial time algorithm for identity testing a black-box ROP. In particular, we show that for a read-on...

BACKGROUND This study aims to investigate the incidence and the relative risk factors of retinopathy of prematurity (ROP) and posterior-ROP (P-ROP): ROP in Zone I and posterior Zone II, as well as to analyze the occurrence of surgical treatment of ROP and to evaluate the short term outcome of the disease in Italy. METHODS It is a prospective multicenter observational study; all infants with a...

Retinopathy of Prematurity (ROP) is a disorder afflicting prematurely born infants. ROP can be positively diagnosed a few weeks after birth. The goal of this study is to build an automatic tool for prediction of the incidence of ROP from standard clinical factors recorded at birth for premature babies. The data presents various challenges including mixing of categorical and numeric attributes a...

OBJECTIVE To determine the incidence and severity of Retinopathy of Prematurity (ROP) in the Murcia region of Spain. METHODS This was a retrospective study of all infants born preterm in the Murcia region during 2004, who were screened for ROP. Our screening criteria were: Infants with a gestational age <or= 32 weeks (GA) or with a birth weight <or= 1500 g (BW). We evaluated sex, GA, BW, pari...

Laser treatment for retinopathy of prematurity (ROP) has been proven to be beneficial. We present a case of uncommon, progressive anterior eye segment complication treated with diode laser photocoagulation for ROP which subsequently required surgical management. A 1210 g premature infant, born at 28 weeks of gestation, had bilateral stage 3 threshold ROP on his first screening, at 5 weeks of ag...

BACKGROUND/AIMS A recent report has highlighted the decreasing prevalence in recent years of severe intraventricular haemorrhage (IVH) in very low birthweight (VLBW) infants (<1500 g). This study attempted to identify the severity of the grade of IVH in infants with stage 3 retinopathy of prematurity (ROP), and to re-examine the association between threshold ROP and IVH. METHODS This was a re...

OBJECTIVE To prospectively study the incidence and nature of retinopathy of prematurity (ROP) at a University Hospital in Riyadh, Kingdom of Saudi Arabia. METHODS This study was carried out the Neonatal Intensive Care Unit of King Khalid University Hospital in Riyadh, Kingdom of Saudi Arabia. One hundred and ninety-five consecutive preterm infants with a birth weight of 2000 g or less were sc...

Rho-type small GTP-binding plant proteins function as two-state molecular switches in cellular signalling. There is accumulating evidence that Rho-of-plants (ROP) signalling is positively controlled by plant receptor kinases, through the ROP guanine nucleotide exchange factor proteins. These signalling modules regulate cell polarity, cell shape, hormone responses, and pathogen defence, among ot...

The plant-specific Rop subfamily of Rho GTPases, most closely related to the mammalian Cdc42 and Rac GTPases, plays an important role in the regulation of calcium-dependent pollen tube growth, H(2)O(2)-mediated cell death, and many other processes in plants. In a search for Rop interactors using the two-hybrid method, we identified a family of Rho GTPase-activating proteins (GAP) from Arabidops...

The Sec1 family of proteins is thought to function in both non-neuronal and neuronal secretion, although the precise role of this protein family has not been defined. Here, we study the function of ROP, the Drosophila Sec1 homolog, in neurotransmitter release. Electrophysiological analyses of transgenic lines overexpressing ROP and syntaxin, a presynaptic membrane protein, indicate that ROP int...