Physical and Chemical Correlates of Microbial Activity and Biomass in Composting Municipal Sewage Sludge

Various physical and chemical parameters were monitored to evaluate their influence on the microbial communities present in composting municipal sewage sludge. Temperature, moisture content, depth, pH, protein content, total nitrogen, total carbon, lipid phosphate biomass, and the rates of microbial incorporation of substrates into lipids were measured at several times throughout the 17- to 19-day composting runs. Temperature was found to have the most consistent and dramatic effect on microbial activity and biomass. When temperatures exceeded 55 to 60°C, microbial activity fell dramatically, usually by more than 1 order of magnitude. Microbial activity was generally greatest in samples taken from the 35 to 50°C areas of the composting piles. Changes in the composition of the compost over time included increased pH, increased protein content, and decreased total organic content. The changes in these parameters appeared to reflect the microbial activity and biomass present. The results of this study indicate that the rate of composting may best be optimized by controlling the composting temperatures, provided that the other parameters fall within reasonable limits in the starting material.     

What makes wild rabbits drink?

Wild rabbits Oryctolagus cuniculus (L) introduced to Australia over a century ago successfully colonized diverse environments in a large part of the continent varying from arid desert, alps, to lush grasslands and coastline where water and salt may be either abundant or very scarce. Wild rabbits caught in Northern Victoria were studied under laboratory conditions, where they adapted to dry pelleted food and drank regularly water and a cafeteria of electrolyte solutions offered. Intracerebroventricular (IVT) infusion of angiotensin II (AII) in doses 10, 50 and 500 ng/h did not increase their water drinking, but increased salt appetite, although it was delayed one or more days after the beginning of AII infusion. IVT infusion of AII 500 ng/h for one day caused a halving in water intake and a tenfold increase in sodium excretion. These were followed by compensatory changes in water and 0.5 M NaCl intake on the consecutive days. IVT infusion of AII 50 ng/h for one day induced an increased urinary sodium excretion, a negative sodium balance which was not followed by an increased salt appetite. IVT infusion of AII 10 ng/h for five days caused a progressive increase in sodium excretion and salt appetite which were significant on the fourth day of infusion and both remained eight-ten times greater than control levels for three days after the cessation of infusion. Water intake was unchanged. IVT infusion of 0.3 M Na-CSF for two days reduced water and food intake, and caused a negative sodium balance on the second day of infusion which was not followed by increase in salt appetite.(ABSTRACT TRUNCATED AT 250 WORDS)     

Improvements in and Environmental Applications of Double-Vial Radiorespirometry for the Study of Microbial Mineralization

Several variations in the scintillation mixture and the filter paper arrangements for double-vial radiorespirometry were compared. Improved efficiencies (44%) and shorter response times were found by adding wetting agents and methanolic NaOH to the scintillation mixture in the filter paper. The scintillation chemicals used did not contain dioxane and were found to be nontoxic to the test microbiota in this system. Covering the inner reaction vial with aluminum foil minimized the reduction in counting efficiency when testing colored or dense environmental samples. Mineralization rates were determined with ¹⁴C-labeled glucose, acetate, and glutamate and [¹⁴C]cellulose- and [¹⁴C]lignin-labeled lignocellulose for composting cow manure, forest soil, and arctic lake sediment microbiota. This improved method can be used in a variety of procedures involving the measurement of microbial mineralizations of organic compounds. Since no liquid scintillation cocktail is used for counting, the radioactive wastes are aqueous or can be incinerated, making disposal easy.     

The synthesis and biological activity of Ala3,14-somatostatin

The tetradecapeptide H-Ala-Gly-Ala-Lys-Asn-Phe-Phe-Trp-Lys-Thr-Phe-Thr-Ser-Ala-OH (Ala³, 14-somatostatin) an analog of the somatotropin release inhibiting factor (somatostatin SRIF) was synthesized by solid phase peptide methods. It shows somatotropin release inhibiting activity $\text{in vitro}$ at 5 μg/ml concentration.     

Permeability of sarcoplasmic reticulum membrane. The effect of changed ionic environments on Ca2+ release

Summary Permeability properties and the effects of a changed membrane potential on Ca²⁺ release of sarcoplasmic reticulum vesicles of rabbit skeletal muscle were investigated by Millipore filtration. The relative permeability of sarcoplasmic reticulum to solutes determined under conditions of isotope exchange at equilibrium and/or under conditions of net flow of solute and water into the vesicles was as follows: sucrose, Ca²⁺, Mn²⁺–, choline⁺, Tris⁺–+, Na⁺, Li⁺, Cl^–. Transient membrane potentials were induced by rapidly changing the ionic environment of the vesicles. Knowledge of the relative permeation rates of the above ions allowed prediction of the direction and extent of membrane polarization. Osmotic effects in the polarization measurements due to the rapid influx of solute and water into the vesicles were minimized by using media containing a fast (K⁺ or Cl^–) and a relatively slow (gluconate^– or choline⁺) penetrating ion.⁴⁵Ca²⁺ efflux from vesicles derived from different parts of the sarcoplasmic reticulum structure was not appreciably changed when vesicles were made more positive inside (choline chloride potassium gluconate) or more negative inside (potassium gluconate choline chloride). These studies suggest that part or all of the ion-induced changes in sarcoplasmic reticulum membrane permeability, previously interpreted to indicate depolarization-induced Ca²⁺ release, may be due to osmotic effects.     

Developmental expression of prion protein gene in brain

Synthesis of the cellular isoform of the prion protein (PrPC) was found to be regulated during development of the hamster brain. PrP poly A(+) RNA was readily detectable 10 days postpartum; after 20 days of age, no change in its level could be detected through 13 months of age. Low levels of PrP poly A(+) RNA were detectable 1 day after birth. By contrast, myelin basic protein poly A(+) RNA was found at high levels in brain at 30 days of age and thereafter declined steadily. Using monospecific PrP antisera, immunoprecipitable cell-free translation products were detected at low levels 2 days after birth and increased progressively through 10 days of age. How the levels of PrP mRNA participate in brain development and function remains to be established.     

Maximum tag to body size ratios for an endangered coho salmon (<Emphasis Type="Italic">O. kisutch</Emphasis>) stock based on physiology and performance

Many coho salmon stocks (Oncorhynchus kisutch) have been in decline during the past three decades. Canada’s most endangered salmon stock, the Thompson River coho salmon, is being studied extensively as managers attempt to reverse these population declines. Investigators are using acoustic telemetry to track the migratory behaviour and survival of the Thompson River (and other) coho salmon stocks. Coho salmon pre-smolts are relatively small compared with salmonid species that are typically studied using acoustic telemetry; therefore the identification of the appropriate sizes of fish and tags to use is critical. This study tested the effects of surgically implanting the three smallest sizes of acoustic tags currently available on the growth, survival, tag retention, swimming performance and physical condition of coho salmon pre-smolts for 300 days post-surgery. Maximum tag size to body size ratios ranged from 15–17% by fork length and 7–8% by mass for the three tag sizes (11 cm fork length for a 6 × 19 mm tag, 12.5 cm for a 7 × 19 mm tag, and 14 cm for a 9 × 21 mm tag). Based on our results, it is unlikely that coho salmon pre-smolts implanted with acoustic transmitters following these size guidelines would have poor survival in studies of freshwater migratory behaviour as a result of the surgery or the tag.     

Electron-impact induced fragmentations and structures of benzeneboronates of acyclic tetraols

The isomeric 4,4′-bi-2-phenyl-1,3,2-dioxaborolanes and 2,7-diphenyl-1,3,6,8-tetraoxa-2,7-diborabicyclo[4.4.0]decanes have been distinguished by their electron-impact induced fragmentation. The bisbenzeneboronates of erythritol, L-threitol, 1-deoxy-D-arabinitol, 1-deoxy-D-lyxitol, 1-deoxy-D-ribitol, 1-deoxy-D-xylitol, 1,6-dideoxygalactitol, and 1,6-dideoxy-L-mannitol are likely to be mixtures of structural isomers.     

Wnt5a Regulates the Assembly of Human Adipose Derived Stromal Vascular Fraction-Derived Microvasculatures

Human adipose-derived stromal vascular fraction (hSVF) cells are an easily accessible, heterogeneous cell system that can spontaneously self-assemble into functional microvasculatures in vivo. However, the mechanisms underlying vascular self-assembly and maturation are poorly understood, therefore we utilized an in vitro model to identify potential in vivo regulatory mechanisms. We utilized passage one (P1) hSVF because of the rapid UEA1+ endothelium (EC) loss at even P2 culture. We exposed hSVF cells to a battery of angiogenesis inhibitors and found that the pan-Wnt inhibitor IWP2 produced the most significant hSVF-EC networking decrease (~25%). To determine which Wnt isoform(s) and receptor(s) may be involved, hSVF was screened by PCR for isoforms associated with angiogenesis, with only WNT5A and its receptor, FZD4, being expressed for all time points observed. Immunocytochemistry confirmed Wnt5a protein expression by hSVF. To see if Wnt5a alone could restore IWP2-induced EC network inhibition, recombinant human Wnt5a (0–150 ng/ml) was added to IWP2-treated cultures. The addition of rhWnt5a significantly increased EC network area and significantly decreased the ratio of total EC network length to EC network area compared to untreated controls. To determine if Wnt5a mediates in vivo microvascular self-assembly, 3D hSVF constructs containing an IgG isotype control, anti-Wnt5a neutralizing antibody or rhWnt5a were implanted subcutaneously for 2w in immune compromised mice. Compared to IgG controls, anti-Wnt5a treatment significantly reduced vessel length density by ~41%, while rhWnt5a significantly increased vessel length density by ~62%. However, anti-Wnt5a or rhWnt5a did not significantly affect the density of segments and nodes, both of which measure vascular complexity. Taken together, this data demonstrates that endogenous Wnt5a produced by hSVF plays a regulatory role in microvascular self-assembly in vivo. These findings also suggest that manipulating Wnt signaling could enhance control of hSVF vascularization in tissue engineering applications.