The influence of optimization target selection on the structure of arterial tree models generated by constrained constructive optimization

The computational method of constrained constructive optimization was used to generate complex arterial model trees by optimization with respect to a target function. Changing the target function also changes the tree structure obtained. For a parameterized family of target functions a series of trees was created, showing visually striking differences in structure that can also be quantified by appropriately chosen numerical indexes. Blood transport path length, pressure profile, and an index for relative segment orientation show clear dependencies on the optimization target, and the nature of changes can be explained on theoretical grounds. The main goal was to display, quantify, and explain the structural changes induced by different optimization target functions.     

Ca2+ Sensitivity of Ca2+-Dependent Protein Kinase Activities Toward Intrinsic Proteins in Synaptosomal Membrane Fragments from Rat Cerebral Tissue

The Ca2+ and calmodulin sensitivity of endogenous protein kinase activity in synaptosomal membrane fragments from rat brain was studied in medium containing Ca2+ plus EGTA using a modified computer programme to calculate free Ca2+ concentrations that took into account the effect of all competing cations and chelators. The Ca2+-dependent phosphorylation of 10 major polypeptide acceptors with Mr values ranging from 50 to 360 kilodaltons required calmodulin in reactions that were all equally sensitive to Ca2+; half-maximal phosphorylation required a free Ca2+ concentration of 45 nM and maximal phosphorylation approximately 110 nM. The significance of these values in relation to published data on the intracellular concentration of free Ca2+ in the nervous system is discussed. One acceptor of 45 kilodaltons was phosphorylated in a Ca2+-dependent reaction that did not require calmodulin. This polypeptide appeared to correspond to the B-50 protein, an established substrate of the lipid-dependent protein kinase C. Further study of this phosphorylating system showed that the reaction was only independent of calmodulin at saturating concentrations of Ca2+; at subsaturating concentrations (in the range 50-130 nM), a small but significant stimulation of the enzyme by calmodulin was demonstrated. The possible significance of this finding is discussed.     

Aboveground nitrogen and phosphorus use by five plantation-grown trees with different leaf longevities

Aboveground nitrogen (N) and phosphorus (P) requirement, retranslocation and use efficiency were determined for 28-year-old red oak (Quercus rubra L.), European larch (Larix decidua Miller), white pine (Pinus strobes L.), red pine (Pinus resinosa Ait.) and Norway spruce (Picea abies (L) Karst.) plantations on a similar soil in southwestern Wisconsin. Annual aboveground N and P requirements (kg/ha/yr) totaled 126 and 13 for red oak, 86 and 9 for European larch, 80 and 9 for white pine, 38 and 6 for red pine, and 81 and 13 for Norway spruce, respectively. Nitrogen and P retranslocation from current foliage ranged from 81 and 72%, respectively, for European larch, whereas red pine retranslocated the smallest amount of N (13%) and Norway spruce retranslocated the smallest amount of P (18%). In three evergreen species, uptake accounted for 72 to 74% of annual N requirement whereas for two deciduous species retranslocation accounted for 76 to 77% of the annual N requirement. Nitrogen and P use (ANPP/uptake) was more efficient in deciduous species than evergreen species. The results from this common garden experiment demonstrate that differences in N and P cycling among species may result from intrinsic characteristics (e.g. leaf longevity) rather than environmental conditions.     

Quantitative analysis of organophosphorus pesticides in freshwater using an optimized firefly luciferase‐based coupled bioluminescent assay

In this paper, a coupled bioluminescent assay, relying on the coupling of the enzymes acetylcholinesterase, S‐acetyl‐coenzyme A synthetase and firefly luciferase, for the detection and quantitation of organophosphorus pesticides, is presented. Using malathion as a model organophosphorus pesticide, the assay was optimized through statistical experimental design methodology, namely Plackett–Burman and central composite designs. The optimized method requires only 20 μL of sample. The linear range for the assay was 2.5–15 μM of malathion, with limits of detection and quantitation of 1.5 and 5.0 μM, respectively. This simple, fast and robust method allows samples to be analyzed at room temperature and without any pretreatment. Copyright © 2013 John Wiley & Sons, Ltd.     

Comparative double-blind study of cephalexin and co-trimoxazole in urinary tract infections.

Treatment with cephalexin 1 g twiec daily and cotrimoxazole 2 tablets twice daily was compared in a double-blind, randomised study of 100 women with urinary tract infections. CO-trimoxazole gave a significantly higher cure rate compared with cephalexin two and six weeks after the one-week course of treatment. The higher failure rate with cephalexin was not related to the age of the patient, presentation, pyelographic appearances, or type of organism in the initial infection. Among the failures all but one of the organisms were sensitive to cephalexin. With the dosage regimen and duration of treatment used in this study cotrimoxazole appears to be superior to cephalexin in the management of acute urinary infections.     

Tissue specific O-linked glycosylation of the neural cell adhesion molecule (N-CAM)

We have shown previously that the predominant N-CAM isoform in skeletal muscle myotubes contains as a result of alternative splicing a novel domain (MSD1) in its extracellular region. Here we show that this region represents a site for O-linked carbohydrate attachment. The lipid tailed N-CAM in myotubes was found to bind peanut lectin while the transmembrane isoform from myoblasts lacking MSD1 did not. In addition, N-CAM from a variety of neural sources failed to bind the lectin. Analysis of 3T3 fibroblasts transfected with various N-CAM cDNAs, showed that peanut lectin binding was correlated specifically with the expression of the MSD1 region. The oligosaccharides isolated from a purified preparation of myotube N-CAM were shown to contain an O-linked oligosaccharide whose core structure was a sialylated version of Gal beta 1----3GalNac which is the structure recognized specifically by peanut lectin. These data provide the first evidence for the expression of O-linked carbohydrate on any N-CAM isoform and more specifically target this oligosaccharide to the MSD1 region of myotube N-CAM.     

Adiponectin multimers and metabolic syndrome traits: relative adiponectin resistance in African Americans

African Americans (AAs) tend to have lower total adiponectin levels compared to European Americans (EA); however, it is not known whether race affects adiponectin multimer distribution and their relationships to metabolic traits. We measured total adiponectin, high molecular weight (HMW), low molecular weight (LMW) (i.e., hexamer), and trimer adiponectin in 132 normoglycemic premenopausal women (75 AAs, 57 EAs), together with measures of total and abdominal fat, plasma lipids, insulin sensitivity (S(i)), and genetic admixture estimates. We found that lower total adiponectin in AAs was explained by reduced LMW, and trimer forms because levels of HMW did not differ between races. In EAs, HMW was highly correlated with multiple metabolic syndrome traits. In contrast, the LMW and trimer forms were most highly correlated with metabolic traits in AAs, including abdominal adiposity, lipids, and S(i). At similar levels of visceral adiposity, AAs exhibited significantly lower LMW adiponectin than EAs. Similarly, at comparable levels of HMW and LMW adiponectin, AAs were more insulin resistant than their EA counterparts. In conclusion, (i) serum adiponectin is lower in AAs predominantly as a result of reduced concentrations of LMW and trimers multimeric forms; (ii) LMW and trimer, not HMW, are most broadly correlated with metabolic traits in AAs. Thus, HMW adiponectin may exert less bioactivity in explaining the metabolic syndrome trait cluster in populations of predominant African genetic background.