Evaluation of microbial culture techniques for the isolation of Pythium insidiosum from equine tissues.

The purpose of this study was to evaluate the effects of sample handling, storage, and culture techniques on the isolation of Pythium insidiosum from infected equine tissues. Tissue and kunker samples obtained immediately posteuthanasia from a horse with subcutaneous pythiosis were used to assess the effects of sample type (kunkers vs. tissues), media type (selective vs. nonselective), storage technique, and storage time on P. insidiosum isolation rate. Overall, isolation rates were higher from fresh kunkers (94.6%) and stored kunkers (76.4%) than from fresh tissues (8.3%) or stored tissues (4.6%). Isolation of P. insidiosum also occurred more often on antibiotic-containing media than on nonselective media for both fresh and stored samples. For samples that were stored for 1-3 days prior to culture, P. insidiosum isolation rates were highest for the following techniques: kunkers stored at room temperature and plated on selective media (100%), kunkers stored at 4 C and then plated on either nonselective (91.7%) or selective (95.8%) media, kunkers stored on cold packs and then plated on either nonselective (93.8%) or selective (100%) media, kunkers stored in ampicillin solution and plated on selective media (100%), and kunkers stored in ampicillin/gentocin solution and plated on selective media (87.5%). For samples stored for 4-5 days, P. insidiosum isolation rates were highest for kunkers stored at 4 C and then plated on either nonselective (81.3%) or selective (87.5%) media, kunkers stored in ampicillin solution and then plated on selective media (87.5%), and kunkers stored in ampicillin/gentocin solution and plated on selective media (87.5%). Results of this study suggest that optimal isolation rates of P. insidiosum from infected equine tissues are achieved by culturing fresh kunkers on selective media. For samples that cannot be processed immediately, acceptable handling techniques include storage at room temperature for up to 3 days, refrigeration for up to 5 days, shipping on cold packs, and storage in antibiotic solution, each combined with subsequent inoculation on selective media.     

Plant–Water Relations of Kidney Bean Plants Treated with NaCl and Foliarly Applied Glycinebetaine

Salinity is at present one of the most serious environmental problems influencing crop growth. It has been extensively demonstrated that salinity affects several physiological processes in the plant, including the plant–water relations of most salt-sensitive crops species. In this study, the effects of salinity on the plant–water relations of kidney bean ( Phaseolus vulgaris L.) and the possibility that foliarly applied glycinebetaine improves these water relations are examined. Kidney bean plants were grown in a greenhouse and treated with 0, 30, 50 and 100 m M NaCl, combined with 0, 10 and 30 m M glycinebetaine in foliar applications. Increased salinity levels decreased stomatal conductance, photosynthetic rate, transpiration and leaf relative water content in the 30, 50 and 100 m M treatments relative to the control treatment. Glycinebetaine applications of 10 m M increased stomatal conductance at 50 m M NaCl, ameliorating significantly the effect of salinity on water relations through increases in the leaf relative water content. At 100 m M NaCl, 30 m M glycinebetaine applications in particular contributed to osmotic stress, and had an adverse effect on plants. Our experiment suggests that glycinebetaine can be used as an alternative treatment to reduce the effects of salt stress on the water relations of salt-sensitive plants, but only to limited salinity levels. Furthermore, the improvement in the water status of kidney beans was dose dependent, suggesting that the concentration of glycinebetaine essential for the survival of salt-sensitive plants is species specific and must be determined individually for each plant species.     

Topographie des Collecteurs Lymphatiques Mammaires de la Chienne

The topography of the lymph drainage was examined by in vivo injections of india ink into the mammary parenchyma of 73 female dogs. Only one gland was injected at a time on each side. Only the cranial abdominal mammary gland had direct drainage to the axillary as well as to the superficial inguinal nodes. The principal routes of drainage differ for each gland. The glands on each side are completely independent as regards their lymph drainage. The cranial thoracic mammary glands on each side had their own collecting duct which led to the sternal lymph nodes. The results of this study suggest to develop a new model for the surgical extirpation of mammary tumors in the bitch.     

Indirect immunofluorescence and immunodiffusion tests in the detection of antibodies to foot-and-mouth disease virus

The antibody response detected by indirect immunofluorescence (IIF) as well as that directed against 140 S and virus infection associated antigen (VIA), as detected by agar immunodiffusion, was studied in three mammal species susceptible to Foot and Mouth Disease Virus, after challenge with living virus, immunization and hyperimmunization with inactivated virus, and immunization followed by challenge. By spot indirect immunofluorescence, antibodies were detected only in animals undergoing an active infection, and were not detected in immunized or hyperimmunized animals. This behaviour was similar to that of the anti-VIA antibodies in the same groups of animals and differed from that of anti-140 S antibodies. It appeared that spot indirect immunofluorescence for the detection of VIA antigen is comparable to the immunodiffusion test, but the speed of IIF and the possibility of handling many samples make it more practical.     

Heterologous strain immunity in bovine babesiosis using a culture-derived soluble Babesia bovis immunogen

The cross-protective capacity of culture-derived soluble immunogens against heterologous Babesia bovis strains from different geographical locations of Latin America was examined. Susceptible yearling cattle were either immunized with immunogens derived from Venezuelan or Mexican strains, or were administered a multi-component immunogen containing antigens of the Australian, Mexican and Venezuelan strains. Cattle were challenged with virulent B. bovis organisms of the Argentinian, Colombian, Ecuadorean, Mexican and Venezuelan strains. The major parameters used to evaluate cross-protection were the following: presence, level and duration of parasitemia; maximal PCV reduction; level and duration of fever; determination of fibrinogen and cryofibrinogen; homologous and heterologous antibody levels; and net gains in body weight. Results showed good protection with a Venezuelan B. bovis immunogen after homologous and heterologous challenge exposures. A low degree of cross-immunity was observed when cattle vaccinated with the Mexican immunogen were challenged with each of the heterologous strains.     

Genotypic effects of sorghum accessions on fecundity of sorghum head bug,Calocoris angustatus Lethiery

Summary Sorghum head bug (Calocoris angustatus Leth.) (Hemiptera: Miridae) is an important pest of grain sorghum in India. We studied the fecundity of head bug females reared for one to three generations on head bug-resistant and head bug-susceptible genotypes during the 1988 and 1989 rainy and 1988–89 post-rainy seasons. Head bug population increase was lower for the first, second and/or third generation when the bugs were reared on IS 2761, IS 19955, IS 14334, IS 23748, IS 16357, IS 17610, and IS 21444 compared with the susceptible controls CSH 1, CSH 5, and CSH 9. These genotypes also suffered a low grain damage (damage rating (DR) 5) (except IS 2761) compared with the susceptible controls (DR>6). A marginal decrease in fecundity was observed when the bugs were reared on IS 2761, IS 14334, IS 16357, IS 20740 and IS 17610 and then transferred to the susceptible control, CSH 1. Sorghum genotypes having lower increase in bug population across generations, suffering low grain damage, and showing adverse effects on fecundity can be used in breeding for resistance to head bugs.     

Use of the Single Seed Descent Method in Breeding Safflower (Carthamus tinctorius L.)

The single seed descent (SSD) method of selection has been evaluated in safflower (Carthamus tinctorius L.). The initial population of this study was a BC₂F₁ from a cross between a well adapted and a high oil cultivar. Transgressive segregation for yield and oil content producing lines with considerably higher values than the better parent was observed in BC₂F₄ and BC₂F₅ generations. These results and the great saving of time and effort makes the SSD method a very desirable tool for safflower breeders.     

Biodiversity of mannose-specific lectins within Narcissus species

Mannose-specific lectins (MSLs) were isolated from the bulbs of 27 species of wild Spanish Narcissi and compared to the commercially available MSL from daffodil (Narcissus pseudonarcissus, NPA). Molecular weight analysis showed the monomers of all the MSLs were at, or around, 12.5 kD. Haemagglutination assays showed that the MSLs exhibited activities at up to four times greater than that displayed by NPA and other MSLs derived from other species such as Galanthus nivalus (snowdrop) and Allium ursinum (ramson). Elution profiles from ion exchange chromatography exhibited similarities for species within the same taxonomic section suggesting that this method could aid in species classification. Further analysis by isoelectric focusing showed many isolectins are present in vivo and that even within a single peak from ion exchange chromatography there are numerous isolectins present. The basis of the isolectin heterogeneity is suggested to reside in the tetraploidy (sometime triploidy) nature of Narcissus genes.     

Impacts of urbanization on Florida Key deer behavior and population dynamics

Rapid human population growth and urbanization have had a negative impact on species biodiversity. As competition for resources between man and wildlife continues, it is important to understand the effects of urbanization on species. Endangered Key deer (Odocoileus virginianus clavium) are endemic to the Florida Keys which have undergone rapid human population growth and development over the past 30 years. Our study objectives were to evaluate the impacts of urban development on Key deer habitat use, population dynamics, behavior, and body mass. We used data from two comprehensive studies on Key deer spanning 30 years to evaluate these changes. Our results suggest that Key deer have become more urbanized, using urban areas more today than they did 30 years ago. Contrary to our predictions, survival was higher for more urban deer than for less urban deer. Problems still exist with mortality factors heavily impacting some portions of the deer population including lower survival associated with less urban male deer. Analysis of Key deer body mass also was converse to our predictions as deer weights appear to have increased over time. Collectively, our results suggest that over the past 30 years Key deer have become more urbanized and that deer plasticity has allowed them to adapt and persist in an urbanizing environment. However, the future ability of Key deer to persist in an environment with continued urban development is unknown. At some threshold, urban development would become unsustainable and unlike other forms of habitat change or environmental disturbances, urban development is in most cases irreversible requiring careful planning in habitat conservation strategies.     

Assessment of the Extent to Which Intensively-studied Lakes are Representative of the Adirondack Region and Response to Future Changes in Acidic Deposition

Many lakes in the Adirondack Mountains, New York, have acidified over the past century due to acidic atmospheric deposition. More recently, most monitored lakes have shown signs of chemical recovery (increase in acid neutralizing capacity) as sulfur deposition levels have declined in response to the Clean Air Act and other emissions control legislation. We used measured and modeled trends in past lakewater acidification and projections of future recovery from acidification to extrapolate results from judgment samples of intensively studied lakes to the population of acid-sensitive Adirondack lakes. Simulations were developed for 70 watersheds using the Model of Acidification of Groundwater in Catchments (MAGIC) to classify lakes according to their sensitivity to change in atmospheric S and N deposition. MAGIC simulations suggested that the modeled Adirondack Long-Term Monitoring Project (ALTM) and Adirondack Effects Assessment Project (AEAP) lakes were largely among the lakes in the population that had acidified most between 1850 and 1990. Most of the modeled ALTM/AEAP lakes were within the top 36% of acid sensitivity, based on model projections of past acidification and future chemical recovery, compared with the 1,829 Adirondack lakes in EPA’s Environmental Monitoring and Assessment Program (EMAP) statistical frame. Results of this research will allow fuller utilization of data from on-going chemical and biological monitoring and process-level studies by providing a basis for regionalization of findings and developing/refining relationships among watershed characteristics, chemical change, and biological responses to changing levels of acidic deposition.