Visual impairment in Swedish children. III. Diagnoses

PURPOSE: To gain an overview of the spectrum of diagnoses among Swedish visually impaired children. METHODS: An epidemiological study of all known visually impaired children was made by review of medical records. RESULTS AND CONCLUSION: In all we found 2373 children, 0-19 years of age, with an age-specific prevalence of 10.9/10,000. The two largest diagnostic groups included neuro-ophthalmological and retinal diseases. The most frequent disorders were cerebral visual impairment, non-hereditary optic atrophy, retinal dystrophy (when regarded as a general entity), congenital hypoplasia of the optic nerve and congenital cataract. Nystagmus secondary to brain disorder, albinism, congenital nystagmus, retinopathy of prematurity and high myopia were also found in a considerable number of patients. The leading diagnoses in children with WHO-defined childhood blindness were non-hereditary optic atrophy, cerebral visual impairment and retinopathy of prematurity. A large proportion of the children, especially in the groups with neuro-ophthalmological disorders and malformations of the posterior segment had additional impairments, emphasizing the importance of a multi-disciplinary approach when assessing multi-handicapped children.     

Interaction of RecBCD enzyme with DNA at double-strand breaks produced in UV-irradiated Escherichia coli: requirement for DNA end processing

The RecBCD enzyme has a powerful duplex DNA exonuclease activity in vivo. We found that this activity decreased strongly when cells were irradiated with UV light (135 J/m2). The activity decrease was seen by an increase in survival of phage T4 2(-) of about 200-fold (phage T4 2(-) has defective duplex DNA end-protecting gene 2 protein). The activity decrease depended on excision repair proficiency of the cells and a postirradiation incubation. During this time, chromosome fragmentation occurred as demonstrated by pulsed-field gel electrophoresis. In accord with previous observations, it was concluded that the RecBCD enzyme is silenced during interaction with duplex DNA fragments containing Chi nucleotide sequences. The silencing was suppressed by induction or permanent derepression of the SOS system or by the overproduction of single-strand DNA binding protein (from a plasmid with ssb+) which is known to inhibit degradation of chromosomal DNA by cellular DNases. Further, mutations in xonA, recJ, and sbcCD, particularly in the recJ sbcCD and xonA recJ sbcCD combinations, impeded RecBCD silencing. The findings suggest that the DNA fragments had single-stranded tails of a length which prevents loading of RecBCD. It is concluded that in wild-type cells the tails are effectively removed by single-strand-specific DNases including exonuclease I, RecJ DNase, and SbcCD DNase. By this, tailed DNA ends are processed to entry sites for RecBCD. It is proposed that end blunting functions to direct DNA ends into the RecABCD pathway. This pathway specifically activates Chi-containing regions for recombination and recombinational repair.     

Physical characteristics of the ECAT 953B/31: a new high resolution brain positron tomograph

A high spatial resolution brain positron tomograph, the ECAT 953B/31, is presented. The machine consists of two 76.5 cm diameter rings (patient port diameter: 36 cm) made of 24 8x8 BGO detector blocks each, each block being coupled to four 1 in(2) Hammamatsu phototubes. The machine has 15 9 cmx1 mm motorized removable septa, which allows reconstruction of 31 slices 3.375 mm apart. The transaxial resolution (FWHM) in the reconstructed image (with wobbling) is 4.5 mm at center, 5.2 mm (tangential) and 5.6 mm at 10 cm from center. With septa out of the field of view (FOV), the axial resolution degrades to 5.5 mm a center and 6.3 mm at 10 cm from center. At 1 muCi/cc with a 250 keV threshold and a 12 ns coincidence window, the sensitivity is 146100 true events, the ratio of randoms to trues is 0.10, the scatter fraction is 17% and the dead-time losses are 30%. With septa out of the FOV, the sensitivity is increased by a factor 3.6, while the scatter fraction reaches 0.9. Images obtained with (18 )F-DG and H(2)(15)O in human brains and (18 )F-DOPA in a baboon brain demonstrate that the ECAT 953B/31 will be suitable for high resolution and for low count rate brain studies.     

On the transport of gaseous matter through permeable media between cylidrical cavities

The solution of the steady-state diffusion equation is found for a geometry consisting of two parallel, infinitely long cavities carrying unequal pressures. A simple expression for the transport of material between the cavities is developed for a practical case. The expression is then generalized to the case where slightly non-parallel alignment of the cavities exists.     

Effectiveness of antismoking public service announcements on children's intent to smoke.

The authors randomly assigned 5th- and 8th-grade students to 1 of 3 treatment conditions to study the effects of frequency of exposure to an antismoking public service announcement (PSA) on the students' intent to smoke over time. They found that, among younger children only, viewing an antismoking PSA at least once reduced smoking intentions, although these positive effects did not remain over time. However, the antismoking PSA was effective for younger at-risk children. After younger at-risk children viewed the antismoking PSA once, their intent to smoke decreased significantly. Notably, these positive effects remained stable over time and mirrored the smoking intentions of younger children who were not identified as at risk. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

THE INFLUENCE OF HYDROLOGICAL CONNECTIVITY ON FOOD WEB STRUCTURE IN FLOODPLAIN LAKES

Hydrological connectivity is an important driver of ecosystem structure in floodplain rivers; however, little is known of how hydrological connectivity affects the structure and functioning of food webs in these systems. This study examines aquatic food web structure in 10 floodplain lakes on a dryland river floodplain in eastern Australia across a connectivity gradient. Results for fishes suggest that benthic carbon sources are more important in high connectivity billabongs than in low connectivity billabongs and that pelagic sources are more important in low connectivity billabongs than in high connectivity billabongs. Fishes in less connected billabongs were also found to feed at higher trophic levels than in more connected billabongs. We hypothesize that in high connectivity billabongs, where suitable benthic primary sources are abundant, common fish species such as carp and bony bream feed as detritivores or herbivores; while in low connectivity billabongs, where benthic sources are less abundant, the same species feed as planktivores, insectivores or piscivores. This dietary difference may also be promoted by greater predation efficiency in less structurally complex low connectivity billabongs. The feeding behaviour of these fish species subsequently influences the trophic positions of fishes higher in the food chain and ultimately the total food chain lengths that high and low connectivity billabongs support. The results of this study highlight the importance of hydrological connectivity to the structure of food webs in these systems and the potential for them to be affected by water resource development. Copyright © 2011 John Wiley & Sons, Ltd.     

Development of a predictive simulation method for thin flash generation in flashless precision forging processes of aluminum parts using FEA and experiments

In this paper, the investigation of thin flash generation in precision forging process of an aluminum long flat part is described. The aim was to derive a predictive simulation method for thin flash generation in order to increase both process and part quality in the future. The forging processes were varied by use of different preforms with equal volumes but different mass distributions while using the same final part geometry. The experimentally forged parts were analyzed concerning the amount and part area of the generated thin flash. The conducted FE simulations were analyzed concerning the hydrostatic pressure values p in the part areas near to the tool gap between upper and lower die immediately before form-filling. For a more detailed comparison, single p values were included to hydrostatic pressure functions P. The comparison between the P functions and the experimentally determined thin flash height shows, that high pressure values as well as high gradients of the P functions indicate less thin flash generation. The method therefore allows a qualitative prediction of thin flash generation. It can provide two kind of information. First: The prediction of the specific locations where thin flash is likely to occur in one final part by use of one single preform. Second: The qualitative prediction of the specific final part areas were thin flash is likely to occur depending on different preform geometries. This method will decreases the necessity of time-consuming forging trials and can shorten the preform designing process in the future.     

Early treatment can improve prognosis in diabetic nephropathy

Prognosis in diabetic nephropathy has changed dramatically during the past decade, and slowing of the disease process has been made possible by intervention against specific risk factors. Nonetheless, diabetic nephropathy has become the leading cause of end stage renal disease. Early detection and prevention, or at least delaying, of disease progression have become crucial aims, and several treatment strategies designed to prevent end stage renal disease have recently been published. The common denominator of these strategies is screening for microalbuminuria in diabetic patients rather than awaiting the appearance of overt symptoms.     

Parental knowledge and choice regarding live and inactivated poliovirus vaccines

BACKGROUND: Concern about the 8 to 10 cases per year of vaccine-associated paralytic poliomyelitis caused by the live oral poliovirus vaccine (OPV) has led to revised guidelines for immunization of children in the United States. The use of inactivated poliovirus vaccine (IPV) at 2 and 4 months of age could require administration of 3 injections per visit until combination products are available. OBJECTIVE: To determine parents' knowledge of poliovirus vaccines and the choices they would make between IPV and OPV. METHODS: Parents of 240 children aged 2 weeks to 18 months under the care of 10 private pediatricians in the Baltimore, Md, metropolitan area were interviewed prior to the announcement of revised advisory committee guidelines. RESULTS: The majority (62.5%) of respondents were not aware that 2 poliovirus vaccines are available. After reviewing standardized information about the vaccines and 2 alternate schedules, most (75%) parents would consult someone (primarily their physician) before making a final choice of a vaccine schedule. If parents made the choice without consulting anyone else, 61.3% would choose to have their child receive IPV and 3 injections per visit as compared with an all-OPV schedule and 2 injections per visit. Inactivated poliovirus vaccine was preferred by most parents because it would reduce the risk for vaccine-associated paralytic poliomyelitis. Oral poliovirus vaccine was preferred by 37.9% of parents primarily because it was given orally. If the number of injections at each visit was the same for both vaccines, 76.3% of parents would choose the IPV schedule, and if the number of injections was reduced to 2 by combining IPV with another vaccine, 87.9% of parents would choose IPV. CONCLUSION: The number of injections per visit is an important issue, but a majority of parents would choose to have their children receive extra injections to prevent the low risk for vaccine-associated paralytic poliomyelitis.