In vitro expansion and differentiation of fresh and revitalized adult canine bone marrow-derived and adipose tissue-derived stromal cells

The objective of this study was to determine the tissue density, in vitro expansion and differentiation of canine adipose tissue-derived (ASC) and bone marrow-derived (BMSC) stromal cells. Primary (P0) and cell passages 1-6 (P1-6) cell doubling numbers (CD) and doubling times (DT) were determined in fresh cells. The P0, P3, and P6 adipogenic (CFU-Ad), osteogenic (CFU-Ob), and fibroblastic (CFU-F) colony forming unit frequencies, lineage specific mRNA levels in differentiated P3 cells and composition of P3 and P6 chondrogenic pellets were assessed in cryogenically preserved cells. Cell yields from bone marrow were significantly higher than adipose tissue. Overall ASC and BMSC CDs and DTs and P3 and P6 CFU-F, CFU-Ad, and CFU-Ob were comparable. The P0 BMSC CFU-Ob was significantly higher than ASC. Lineage specific mRNA levels were higher in differentiated versus control cells, but similar between cell types. Protein was significantly greater in P3 versus P6 ASC chondrogenic pellets. Based on these findings, fresh and revitalized canine ASCs are viable alternatives to BMSCs for stromal cell applications.     

Long-term persistence of prairie dog towns: insights for designing networks of prairie reserves

We studied the persistence of 281 towns of the black-tailed prairie dog (Cynomys ludovicianus) from surveys conducted in Oklahoma in 1966 and 1967 and again in 1988 and 1989. Town size during initial surveys tended to increase along a northwesterly gradient toward the panhandle of the State, and larger towns tended to occur in clusters while small towns occurred as isolates. Persistence of prairie dog towns from 1967 to 1989 increased significantly with town size and decreased with town isolation, with higher persistence for towns that occurred in landscapes with greater coverage of other towns. Comparisons to our studies of persistence of towns mapped in 1989 and resurveyed in 1997 [Journal of Mammalogy, 82 (2001) 937] indicate that the latter part of this pattern was reversed, with persistence highest for the most isolated towns. The reversal in persistence patterns may be attributed to an outbreak of plague (Yersinia pestis) during the early 1990s, favoring isolated towns. We recommend adaptive management and a mixed strategy for the development of prairie reserves which should include networks (clusters) of relatively large reserves, along with large but isolated reserves across the species’ native range.     

Study of Ammonium Contamination in Leachates from an Ultisol Following Application of Various Types of Amendment

The composition of leachates from an Ultisol reconstructed inlysimeters and amended with limestone, sugar foam waste and gypsum rock was studied. The typical rainfall of the area fromwhich the soil was collected was simulated under laboratory conditions over a five-month period. The soil samples treated with gypsum behaved markedly differently from the rest. Thus, the samples amended with gypsum gave leachates with substantially increased ammonium contents that might result in contamination of aquifers. The gypsum-treated samples alsoexhibited marked differences in pH, EC and the Ca, Mg, Na andK contents from the rest.     

Effect of fermentation and autoclaving on dietary fiber fractions and antinutritional factors of beans (Phaseolus vulgaris L.)

The effect of fermentation on antinutritional factors and also on total dietary fiber (TDF), insoluble (IDF) and soluble (SDF) dietary fiber fractions was studied in beans (Phaseolus vulgaris L.). The processes studied were two types of fermentation (lactic acid and natural), and a portion of the obtained flours were processed by autoclaving. The dietary fiber (DF) content and its components were determined using the enzymatic-gravimetric and enzymatic-chemical methods. The TDF content ranged from 24.5% dry matter (DM) in the raw to 25.2% DM in the processed beans. All the processing treatments significantly decreased the SDF content, and irrelevant changes were noticed in the IDF content of processed beans. Cellulose content of all samples was reduced by the processing treatments. Correspondingly, higher amounts of resistant starch was observed in the processed beans, except in the lactic acid fermented ones. However, the levels of pectic polysaccharides and Klason lignin were higher in the samples fermented by Lactobacillus plantarum. The action of microorganisms was determinant for the different degradation of the bean cell wall, disrupting the protein-carbohydrate integration, thus reducing the solubility of DF.     

Cadaverine production by Azospirillum brasilense and its possible role in plant growth promotion and osmotic stress mitigation

Polyamines are considered as plant growth regulating compounds; among them, cadaverine has been correlated with root growth promotion or osmotic stress mitigation in some plant species. The purpose of this study was to evaluate the capacity of bacterial Azospirillum brasilense Az39 strain to produce cadaverine in chemically defined medium and inoculated plants, and to correlate this capacity with root growth promotion or osmotic stress mitigation in hydroponics conditions. To evaluate cadaverine production in chemically defined medium A. brasilense Az39 was cultivated aerobically at 30 °C and 80 rpm in NFb medium or NFb-l supplemented with the precursor l-lysine. To evaluate the bacterial cadaverine production and growth promotion in plants, rice (Oryza sativa L.) cv. El Paso 144 seedlings were inoculated and hydroponically cultured under optimal conditions in growth chamber. In both, cadaverine was identified and quantified by dansyl-derivative method using a fluorescence-HPLC system, and lysine decarboxylase (LDC) activity was determined by ¹⁴CO₂ production in a closed tube system fed with [¹⁴C]-lysine. To evaluate the possible role of bacterial cadaverine in osmotic stress conditions, abscisic acid (ABA) production was analyzed in rice seedlings hydroponically cultured under 0 (no stress), ?0.47 (stress) or ?0.82 (severe stress) MPa osmotic potential generated by mannitol, with the addition of 1 nM or 1 μM cadaverine or A. brasilense Az39 inoculation. Our results indicate that A. brasilense Az39 promoted root growth and helped mitigate osmotic stress in rice seedlings, due in part to cadaverine production.     

Gas-phase ionic reactions: dynamics and mechanism of nucleophilic displacements

Nucleophilic displacement reactions (the SN2 reaction) of ions in the gas phase are a prototypical reaction system that allows a study of dynamics, mechanisms, and structure-energy relations. This article reviews aspects of the kinetics (especially the applicability of statistical reaction rate theory), the relation of structure and reactivity, and the effects of small numbers of solvent molecules on the reaction and compares the behavior of the ionic reaction in the gas phase with that in solution.     

A Profound Effect of Hyperthermia on Survival of Litopenaeus vannamei Juveniles Infected with White Spot Syndrome Virus

This study was conducted to examine the effect of increasing seawater temperature on White Spot Syndrome Virus (WSSV) infection in juvenile Pacific White shrimp ( Litopenaeus vannamei ). Infection by WSSV was achieved using two methods, intramuscular injection and per os (oral) administration. Forty injected and 20 per os infected animals were kept in heated tanks at 32.3 ± 0.8 C, and the same number of WSSV infected animals were maintained in tanks at ambient temperature (25.8 ± 0.7 C). Despite the route of exposure, there were no survivors among the animals kept at ambient temperature; whereas, in heated tanks the survival of the WSSV infected juvenile shrimp was always above 80%, suggesting the existence of a beneficial effect from hyperthermia that mitigated the progression of WSSV disease. Moreover, this beneficial effect was not attributable to viral inactivation. Infected animals kept at 32 C had histologically detectable lymphoid organ spheroids suggestive of a chronic viral infection but were PCR negative (hemolymph) for WSSV. These findings might be related to low viral replication in WSSV-infected shrimp held at the higher environmental temperature. When the WSSV-infected shrimp were transferred from 32 C to ambient temperature, the mortality from WSSV ensued and was always 100%. Although the mechanism related to the beneficial effect of heating was not determined, our results indicate that increasing the water temperature modifies dramatically the natural history of the WSSV disease and the survival curves of WSSV-infected juvenile Pacific White shrimp.     

Development of a DNA-based method aimed at identifying the fish species present in food products

Analysis of restriction fragment length polymorphism (RFLP) profiles of a 464 bp amplicon obtained from the mitochondrial cytochrome b gene was used to differentiate between several different fish species. The method was tested by a collaborative study in which 12 European laboratories participated to ascertain whether the method was reproducible. Each laboratory was required to identify 10 unknown samples by comparison with RFLP profiles from authentic species. From a total of 120 tests performed, unknown samples were correctly identified in 96% of cases. Further work attempting to use the method to analyze mixed and processed fish samples was also performed. In all cases the species contained within mixed samples were correctly identified, indicating the efficacy of the method for detecting fraudulent substitution of fish species in food products.     

Improved efficiency of in vitro propagation of Camellia reticulata cv. Captain Rawes

Effects of various factors were studied on the in vitro multiplication and rooting of a clone of Camellia reticulata cv. Captain Rawes established in vitro from shoots of an adult tree. Multiplication rates were increased by repeated harvesting of cultures in which shoots were subcultured in a horizontal rather than a vertical position. Best rooting responses were obtained with 175.3 mM sucrose in the rooting medium using 8 week old shoots cultured in 500 ml glass jars; these shoots contained more anthocyanin than those from test-tube cultures. The orientation and repeated harvesting of the mother shoots had no effect on rooting response.