Leakage-resistant blood vessels in mice transgenically overexpressing angiopoietin-1

Angiopoietin-1 (Ang1) and vascular endothelial growth factor (VEGF) are endothelial cell-specific growth factors. Direct comparison of transgenic mice overexpressing these factors in the skin revealed that the VEGF-induced blood vessels were leaky, whereas those induced by Ang1 were nonleaky. Moreover, vessels in Ang1-overexpressing mice were resistant to leaks caused by inflammatory agents. Coexpression of Ang1 and VEGF had an additive effect on angiogenesis but resulted in leakage-resistant vessels typical of Ang1. Ang1 therefore may be useful for reducing microvascular leakage in diseases in which the leakage results from chronic inflammation or elevated VEGF and, in combination with VEGF, for promoting growth of nonleaky vessels.     

Biospheric primary production during an ENSO transition

The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) provides global monthly measurements of both oceanic phytoplankton chlorophyll biomass and light harvesting by land plants. These measurements allowed the comparison of simultaneous ocean and land net primary production (NPP) responses to a major El Ni?o to La Ni?a transition. Between September 1997 and August 2000, biospheric NPP varied by 6 petagrams of carbon per year (from 111 to 117 petagrams of carbon per year). Increases in ocean NPP were pronounced in tropical regions where El Ni?o-Southern Oscillation (ENSO) impacts on upwelling and nutrient availability were greatest. Globally, land NPP did not exhibit a clear ENSO response, although regional changes were substantial.     

Design of Nonionic Surfactants for Supercritical Carbon Dioxide

Interfacially active block copolymer amphiphiles have been synthesized and their self-assembly into micelles in supercritical carbon dioxide (CO2) has been demonstrated with small-angle neutron scattering (SANS). These materials establish the design criteria for molecularly engineered surfactants that can stabilize and disperse otherwise insoluble matter into a CO2 continuous phase. Polystyrene-b-poly(1,1-dihydroperfluorooctyl acrylate) copolymers self-assembled into polydisperse core-shell-type micelles as a result of the disparate solubility characteristics of the different block segments in CO2. These nonionic surfactants for CO2 were shown by SANS to be capable of emulsifying up to 20 percent by weight of a CO2-insoluble hydrocarbon into CO2. This result demonstrates the efficacy of surfactant-modified CO2 in reducing the large volumes of organic and halogenated solvent waste streams released into our environment by solvent-intensive manufacturing and process industries.     

Evaluation of Practical Feed Formulations and Dietary Supplements for Red Swamp Crayfish

Three 6 wk feeding trials were conducted with juvenile red swamp crayfish Procambarus clarkii in a flow-through culture system to evaluate practical feed formulations and specific dietary sup plements. Diets were formulated to contain 30% crude protein from various practical ingredients with or without supplemental cholesterol, lecithin, astaxanthin, vitamin premix and mineral premix. Peanut meal consistently provided inferior weight gain of crayfish compared to soybean, fish and shrimp meals, and a combination of soybean meal and fish meal supported the most rapid weight gain. Supplementation of 1.0% cholesterol did not enhance crayfish weight gain compared to a basal diet, whereas supplementation of 6% lecithin improved weight gain. Astaxanthin supplementation at 13 mg/kg diet marginally improved crayfish weight gain compared to a diet containing 1% beta-carotene. Deletion of a complete vitamin premix impaired crayfish weight gain while deletion of a trace mineral premix did not. Results from this study indicate that protein quality significantly influenced weight gain of crayfish in a flow-through culture system, and supplernentation of a complete vitamin premix was most critical.     

Immunological response of chickens to eastern equine encephalomyelitis virus

The dominant immunoglobulin against eastern equine encephalomyelitis (EEE) virus and its duration and the longevity of the EEE virus haemagglutination inhibition (HI) antibodies were determined in sentinel and 125 immunised and hyperimmunised domestic chickens by enzyme-linked immunosorbent assay and the HI test respectively. The chickens ranged in age from 10 weeks to 18 months, were of varied pedigrees and from different countries. Results show that the HI antibody (IgG) is short-lived. It peaks and disappears within 30 days. The secondary response is dominated by the IgM immunoglobulin which is relatively long-lasting. These results are contrary to classical expectations and were observed in all the chickens studied. If these observations are found to be characteristic of birds generally, the present standard method of EEE virus seroepidemiological surveillance must be modified to be effective.     

Effects of simulated precipitation extremes on crayfish (Procambarus clarkii Girard) oviposition in artificial burrows

Mature female Procambarus clarkii were housed individually in artificial burrows simulating conditions in natural burrows. Crayfish were exposed to conditions of simulated temporary flooding dislocation (Experiment 1) or simulated drought (Experiment 2). In Experiment 1, females were dislocated from burrows to simulate 0, 1, 3 or 6 temporary flooding dislocations, and in Experiment 2, females were exposed to the following simulated drought conditions: wet control (no drought), dry control (no free water), month‐long periods without free water during July, August, September and October (1 month drought), two consecutive months without free water (August–September), and three consecutive months without free water (August–October). In Experiment 1, no significant differences in survival or oviposition rate were observed following transfer of individuals from ‘settled/sealed’ burrows to ‘new burrow’ containers, even after six consecutive dislocations. In Experiment 2, simulated drought of 2 or 3 month's duration had a significant negative impact on oviposition. Survival was significantly reduced only among females exposed to no free water during the 6‐month study. No spawning occurred without the presence of free water in the burrows, and when free water was absent during the peak spawning months of September and/or October, oviposition was delayed until free water was returned. These results indicate that brood female P. clarkii can withstand short‐term conditions without free water in the burrow with little effect, but reproduction and survival are significantly reduced by prolonged drought.     

Economic analysis of aquaponics and hydroponics production in the U.S. Midwest

This article examined the profitability of aquaponics in the U.S. Midwest. Three sources of data were considered for the study: (1) three active aquaponics farms, (2) a university greenhouse experiment, and (3) published research. The first analysis compares the economics of aquaponics and hydroponics systems under similar operations. Results suggest that the aquaponics system requires higher investment and operating cost but has lower production of vegetables compared with the hydroponics system. However, if aquaponics vegetable production is managed as an organic production, and the produce is sold at 20% premium price, aquaponics becomes profitable. The second analysis constructed three different representative farm sizes of aquaponics production of basil and tilapia—small, medium, and large. The production of basil provides better economic returns than the fish. All farm sizes are feasible when the basil price is above $10.00 per kg. The larger farm has the best results because of lower cost of production.     

Model substrates for an RNA enzyme

M1 RNA, the catalytic RNA subunit of Escherichia coli ribonuclease P, can cleave novel transfer RNA (tRNA) precursors that lack specific domains of the normal tRNA sequence. The smallest tRNA precursor that was cleaved efficiently retained only the domain of the amino acid acceptor stem and the T stem and loop. The importance of the 3' terminal CCA nucleotide residues in the processing of both novel and normal tRNA precursors implies that the same enzymatic function of M1 RNA is involved.     

Assessment of glycosaminoglycan concentration in equine synovial fluid as a marker of joint disease.

A modification of a colorimetric assay was used to determine synovial fluid total and individual sulphated-glycosaminoglycan concentration in various clinical presentations of joint disease in horses. Concentrations of synovial fluid and serum sulphated-glycosaminoglycan (GAG) were measured by the 1,9-dimethylmethylene blue (DMMB) dye assay in normal horses (n = 49), horses with acute (n = 26) or chronic (n = 27) joint disease (defined by clinical, radiographic, and clinicopathological parameters), and horses with cartilaginous lesions at diagnostic arthroscopy, but with normal radiographs and synovial fluid (n = 9). Horses with acute joint disease were subdivided into moderate acute (n = 21) and severe acute (n = 5) joint disease on the basis of synovial fluid analysis and clinical examination. Horses with chronic joint disease were subdivided into mild chronic (n = 9), moderate chronic (n = 10), and severe chronic (n = 8) joint disease on the basis of synovial fluid analysis, clinical examination, and radiographic findings. The concentrations of chondroitin sulphate (CS) and keratan sulphate (KS) were analyzed in each sample following sequential enzymatic digestion of the sample with chondroitinase or keratanase. In addition, the concentration of hyaluronate (HA) in each sample was determined by a colorimetric assay following digestion of the sample with microbial hyaluronidase.(ABSTRACT TRUNCATED AT 250 WORDS)