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Greatest Contributor (greatest + contributor)

Distribution by Scientific Domains

Medical Sciences	60%
Chemistry	40%

Selected Abstracts

Persistent Organic Pollutants in Fish Oil Supplements on the Canadian Market: Polychlorinated Biphenyls and Organochlorine Insecticides

JOURNAL OF FOOD SCIENCE, Issue 1 2009
Dorothea F.K. Rawn
ABSTRACT:, Fish and seal oil dietary supplements, marketed to be rich in omega-3 fatty acids, are frequently consumed by Canadians. Samples of these supplements (n,= 30) were collected in Vancouver, Canada, between 2005 and 2007. All oil supplements were analyzed for polychlorinated biphenyls (PCBs) and organochlorine insecticides (OCs) and each sample was found to contain detectable residues. The highest ,PCB and ,DDT (1,1,1-trichloro-di-(4-chlorophenyl)ethane) concentrations (10400 ng/g and 3310 ng/g, respectively) were found in a shark oil sample while lowest levels were found in supplements prepared using mixed fish oils (anchovy, mackerel, and sardine) (0.711 ng ,PCB/g and 0.189 ng ,DDT/g). Mean ,PCB concentrations in oil supplements were 34.5, 24.2, 25.1, 95.3, 12.0, 5260, 321, and 519 ng/g in unidentified fish, mixed fish containing no salmon, mixed fish with salmon, salmon, vegetable with mixed fish, shark, menhaden (n,= 1), and seal (n,= 1), respectively. Maximum concentrations of the other OCs were generally observed in the seal oil. The hexachlorinated PCB congeners were the dominant contributors to ,PCB levels, while ,DDT was the greatest contributor to organochlorine levels. Intake estimates were made using maximum dosages on manufacturers' labels and results varied widely due to the large difference in residue concentrations obtained. Average ,PCB and ,DDT intakes were calculated to be 736 ± 2840 ng/d and 304 ± 948 ng/d, respectively. [source]

Fractional contribution of major ions to the membrane potential of Drosophila melanogaster oocytes

ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 4 2009
Susan M. Munley
Abstract In ovarian follicles of Drosophila melanogaster, ion substitution experiments revealed that K+ is the greatest contributor (68%) in setting oocyte steady-state potential (Em), while Mg2+ and a metabolic component account for the rest. Because of the intense use made of Drosophila ovarian follicles in many lines of research, it is important to know how changes in the surrounding medium, particularly in major diffusible ions, may affect the physiology of the cells. The contributions made to the Drosophila oocyte membrane potential (Em) by [Na+]o, [K+]o, [Mg2+]o, [Ca2+]o, [Cl,]o, and pH (protons) were determined by substitutions made to the composition of the incubation medium. Only K+ and Mg2+ were found to participate in setting the level of Em. In follicles subjected to changes in external pH from the normal 7.3 to either pH 6 or pH 8, Em changed rapidly by about 6,mV, but within 8,min had returned to the original Em. Approximately half of all follicles exposed to reduced [Cl,]o showed no change in Em, and these all had input resistances of 330,k, or greater. The remaining follicles had smaller input resistances, and these first depolarized by about 5,mV. Over several minutes, their input resistances increased and they repolarized to a value more electronegative than their value prior to reduction in [Cl,]o. Together, K+ and Mg2+ accounted for up to 87% of measured steady-state potential. Treatment with sodium azide, ammonium vanadate, or chilling revealed a metabolically driven component that could account for the remaining 13%. © 2009 Wiley Periodicals, Inc. [source]

A new way of looking at Caesarean section births

AUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 4 2007
Fergus P. McCARTHY
Abstract Aims:, To implement the Robson Ten Group Classification System (TGCS) at the Royal Women's Hospital (RWH), Melbourne, in order to determine the main contributors to the rising Caesarean section (CS) rate. Methods:, The TGCS divides women into ten groups according to parity, past obstetric history, singleton or multiple pregnancy, fetal presentation, gestational age and mode of onset of labour/delivery. The TGCS was applied retrospectively to the population of women who had a registered birth at the RWH between January 2005 and 31 December 2005. Results:, A total of 5833 women gave birth to 6011 babies during the study period. A total of 1651 women (28.3%) had a CS birth. The total CS rates ranged from 3.7% (group 3) to 100% (group 9). Women in groups 1 and 2 were the greatest contributors to the emergency CS rate, 4.2% and 4.9%, respectively. Women in group 5 were the single greatest contributor to both the elective CS rate and the total CS rate. Conclusions:, The TGCS was successfully implemented at the RWH in 2005. The TGCS is ongoing, enabling monitoring of CS rates. The Robson TGCS demonstrates the need to focus on the care of women in groups 1, 2 and 5 in particular, if CS rates are to be reduced. [source]

Assessment of the upper limb in acute stroke: The validity of hierarchal scoring for the Motor Assessment Scale

AUSTRALIAN OCCUPATIONAL THERAPY JOURNAL, Issue 3 2010
Rebekah L. Pickering
Background/aim:, Stroke is the greatest contributor to disability in Australian adults and much of this disability results from a stroke-affected upper limb. This study aimed to determine the validity of hierarchal scoring for the upper limb subscale of the Motor Assessment Scale (UL-MAS) in acute stroke using Rasch analysis. Method:, This study applied Rasch analysis to 40 UL-MAS assessment results across 25 subjects to determine the validity of the hierarchy of the three upper limb subsets: upper arm function (six), hand movements (seven) and advanced hand activities (eight). Rasch analysis examines the relationship between ,item difficulty' and ,person ability' and produces an output which represents the difficulty of each item in relation to each other. Results:, As hypothesised, the hierarchy was upheld within subset 6. In subset 7, the hierarchy was not upheld. Results indicated that item 3 was the least difficult, followed by items 1, 4, 2, 5 and 6 in order of increasing difficulty. In subset 8 the hierarchy was not upheld. Results indicated that item 1 was the least difficult, followed by item 6, then 2 and 5 of equal value and then 3 and 4 of equal value. Conclusions:, The hierarchal scoring is not supported for subsets 7 and 8 and future research is required to explore the validity of alternate scoring methods. At present, the authors recommend that the UL-MAS should be scored non-hierarchally, meaning that every item within the subsets should be scored regardless of its place within the hierarchy (UL-MAS-NH). [source]