DESORPTION OF PHOSPHATE FROM SOILS USING ANION EXCHANGE RESINS

After 100h reaction with Cl-resin and 300h reaction with HCO₃-resin (approaching equilibrium), the concentration of anions complementary to phosphate was the critical variable affecting the transfer of P from soil to resin. Solution concentrations of H₃0⁺, Ca²⁺ and phosphate indicated that desorption of P by OH^-, and dissolution of Ca phosphates, controlled P release from soils. P extracted by HCO₃-resin was much greater than by Cl-resin from an acid soil, due to lower total anion and higher desorbing anion concentrations, but there was little difference between the two resins with a calcareous soil. HCO₃-resin extracted a constant proportion of isotopically-exchangeable P from different soils whereas Cl-resin did not. Anion exchange resins provide a convenient means for producing P desorption curves for soils.     

Malassezia dermatitis in the dog: a retrospective histopathological and immunopathological study of 86 cases (1990–95)

A retrospective histopathological and immunopathological study was conducted on 86 dogs with Malassezia dermatitis. West Highland White terriers, English Setters, Shih Tzus, Basset Hounds, American Cocker Spaniels, spayed females, and castrated males were found to be at increased risk. The histopathological reaction pattern of lymphocytic superficial perivascular to interstitial dermatitis with parakeratotic hyperkeratosis, irregular epidermal hyperplasia, diffuse intercellular oedema and lymphocytic exocytosis was found to be consistent with a diagnosis of Malassezia dermatitis whether yeast were histologically visible (73.3% of the cases) or not (26.7%). Immunopathological studies revealed that 60– > 90% of the inflammatory cells within the epidermis, and 25–75% of those within the dermis were CD3+T lymphocytes, and that the only immunoglobulin-positive cells were dermal plasma cells.     

The life history of Haplorchis pumilio (Looss, 1896) from cultured tilapias

Abstract. The metacercaria of Haplorchis pumilio (Looss, 1896) (Digenea: Hetero-phyidae) was found to occur commonly in intensively reared tilapias ( Tilapia, Sarotherodon ) in an East African fish farm. The life cycle on the farm was found to involve the gastropod Melanoides tuberculata (Müller) as the first intermediate host. The infection was experimentally transmitted to fish in fresh water from naturally infected molluscs. The salinity of the water on the farm varied with season from 0 to 3%₀, but cercariae were shown to remain infective up to 10%₀ although longevity was reduced at 7.5%₀. Piscivorous predators, Ardea cinerea L., Phalocrocorax sp. and Varanus sp., which were resident or regular visitors to the farm were heavily infected with the parasite. Mice, hamsters and pigeons were found to be convenient laboratory hosts. H. pumilio shows a lack of specificity at the second intermediate and final host level as well as a wide geographic range and has been reported to infect man. Its potential as a possible cause of zoonoses, and control methods are discussed.     

The Impact of Migration on Social Capital: Do Migrants Take Their Bowling Balls with Them?

Questions surrounding the impact of population migration on social capital is the focus of this study. Putnam observed that “for people as for plants, frequent repotting disrupts root systems. It takes time for a mobile individual to put down new roots.” However, because of a trending decrease in mobility over time, Putnam rules out migration as an explanation for the long‐term decline in social capital that was the subject of his widely read 1995 book Bowling Alone: America's Declining Social Capital. This study undertakes an empirical examination of the impact of migration on county‐level social capital, which in tribute to Putnam one might view as an attempt to answer the question—do migrants take their bowling balls with them when they move? The potential for county‐level migration of population to impact social capital levels at particular locations in space arises from the conventional argument that social capital promotes trust and cooperation among agents. This trust increases socially efficient collective action but requires investment in relationships and commitment of scarce resources to build social capital. It seems plausible that migration of population might have a negative impact on the stock of social capital by interfering with trust and cooperation among agents. However, it is also possible that migrants may take their social capital with them to new places of residence. In other words, the propensity to join social and civic organizations might reflect inherent traits of individuals who are willing to make commitments of their resources to building social capital in any community where they reside.     

Effect of Prosthesis Number and Position on Rima Glottidis Area in Equine Laryngeal Specimens

Objective— To assess the effect of 1 or 2 laryngeal prosthetic sutures on rima glottidis areas in equine laryngeal specimens. Study Design— Experimental, randomized design. Animals— Cadaveric equine larynges (n=16). Methods— Larynges were collected from 10 horses; 2 sutures each were preplaced in the right and left sides of each larynx. A dorsal suture (DS) was placed through the caudal rim of the dorsal midline of the cricoid cartilage, under the cricopharyngeus muscle and through the proximal and rostral aspect of the muscular process. A lateral suture (LS) was placed 1.5 cm lateral to the DS and through the muscular process more distal and caudal to the 1st suture. Larynges were positioned in a customized stand and the rima glottidis photographed after each suture (LS or DS) or suture combination (CS) was tied in random sequence. An additional 6 larynxes were used to determine whether the tension applied to the sutures was repeatable. Sutures were preplaced in both the right and left side of each larynx as described above and each suture and CS was tied and released 3 times in each larynx. Photographs were taken of the rima glottidis after each suture or CS was tied generating 3 replicates for each suture configuration on each side of the 6 larynges. Results— Mean rima glottidis area was not different between DS and LS when tied alone (P=.85); however, mean area after CS (DS+LS) was greater than DS (P<.001) and LS (P<.001) alone. The coefficient of variation for the 6 suture patterns were low (1–7%) and the intraclass correlation coefficient estimates were very high (0.997–0.998) demonstrating excellent repeatability between replicates for each of the 3 suture configurations. Conclusion— Our results suggest that laryngoplasty using 2 prostheses; 1 placed dorsally in the cricoid and through the rostral and proximal muscular process and 1 placed 1.5 cm lateral to the 1st and more caudal and distal in the muscular process results in a greater cross sectional area of the rima glottidis than either suture used alone. Clinical Relevance— Seemingly prosthetic sutures contribute independently to each other in determining the contour of the rima glottidis. Use of 2 prosthetic sutures improves crosssectional area of the rima glottidis compared with each suture alone and may improve surgical outcome in laryngoplasty.     

Disinfection of Oreochromis mossambicus (Peters) eggs against commonly occurring potentially pathogenic bacteria and fungi under artificial hatchery conditions

Abstract. There is an increasing potential for artificial incubation of tilapia eggs. Hatchability observed in artificial systems is less than 62%. Four chemicals generally used as disinfectants for the fish eggs were tested in a controlled experiment together with ultraviolet irradiation of the water. A range of dose levels was tested for each chemical and is compared and assessed in terms of improved hatching rates. Effective disinfection improved the hatchability of eggs above 90%.     

THE EFFECT OF THE EARTHWORM DENDROBAENA RUBIDA ON THE SOLUBILITY OF LEAD, ZINC, AND CALCIUM IN HEAVY METAL CONTAMINATED SOIL IN WALES

The quantities of lead, zinc, and calcium dissolved by various extraction techniques from soil, earthworm faeces, and decayed earthworm (Dendrobuena rubida, Savigny) corpses have been studied. A small proportion of the total metals was water soluble and the amount of lead in faeces was significantly higher than in soil. Putrefied earthworm extracts gave by far the highest concentrations of all three metals. Acetic acid extractable lead was higher in soil than faeces but putrified earthworm extracts gave the highest concentration of lead. The quantities of zinc and calcium extracted were lowest in soil, higher in faeces, and much higher in decomposed earthworms. This particular species of earthworm can therefore be considered as a possible source of lead and zinc contamination in heavy metal polluted, acid soil.