The survival of the black tobacco farmer: Empirical results and policy dilemmas

Panel data from a survey of small-scale farmers in the North Carolina Piedmont are used to investigate the survival of black smallholders. Results of a multivariate analysis show that owning tobacco quota and having high gross farm income, high amounts of on-farm household labor and small household size increase the propensity to survive in agriculture. Over the five-year period studied, approximately 50 percent of the original respondents were no longer actively operating farms. These results point to the complex problems that policies designed to assist minority and small-scale farmers must address.Revised version of a paper presented at the annual meetings of the Rural Sociological Society, Norfolk, Virginia, August, 1990. This research received support from the North Carolina State University Title XII Strengthening Grant (AID/DSAN-XII-G-103) funded jointly by the U.S. Agency for International Development and the North Carolina Agricultural Research Service and conducted in collaboration with the North Carolina Agricultural Extension Service and the North Carolina A&T State University (Greensboro). Additional support was received from the North Carolina Agricultural Foundation. The opinions expressed are those of the authors.     

NAVICULAR BONE FRACTURE IN THE PELVIC LIMB IN TWO HORSES

The case history, radiographic and scintigraphic findings of two horses with pelvic limb navicular bone fractures are presented. In both cases the fractures were of traumatic origin. One horse had a bilateral fracture of the navicular bone, distal border, the other horse had a fracture of the proximal articular border in one pelvic limb navicular bone.     

Failure of pH to predict ionized calcium percentage in healthy horses

Blood, serum, and plasma total calcium concentrations and plasma and serum ionized calcium concentrations were anaerobically determined by use of a calcium-specific electrode for samples obtained from 39 healthy horses. Mean (+/- SD) serum ionized calcium concentration was 6.6 +/- 0.3 mg/dl (1.6 +/- 0.1 mmol/L) and the mean serum ionized calcium percentage was 58.2 +/- 3.4%. Serum ionized calcium percentage was not significantly correlated with serum pH. Plasma ionized calcium percentage was weakly correlated with plasma pH (r = -0.480; P less than or equal to 0.05). Ionized calcium concentration was determined in serum samples manipulated in vitro by additions of 1 to 80 microliters of 0.1N hydrochloric acid or sodium hydroxide to yield 6 to 10 pH values between 6.8 and 8.2. In all horses, the relationship between serum ionized calcium percentage and serum pH at these pH values was then examined by use of a repeated-measures multiple regression analysis. Correlations between serum ionized calcium percentage and adjusted serum pH value for each horse were highly significant (P less than or equal to 0.05); however, analysis of pooled data from all horses indicated that a statistically significant relationship between serum pH and ionized calcium percentage did not exist. Lack of a significant relationship between these variables was most likely attributable to heterogeneity of variance of ionized calcium percentage among horses, reflecting variation in undefined biochemical constituents of serum that affect the equilibrium of calcium binding. When it is essential to evaluate the calcium status of a horse, direct measurement of serum ionized calcium concentration is recommended.     

Radula Tooth Structure of the Gastropod Conus imperialis Elucidated by Scanning Electron Microscopy

Scanning electron microscopy of the hollow, harpoon-like radula tooth of the toxoglossan gastropod Conus has elucidated the structure and relationships of its component parts: apex, cutting edge, barbs, serration, adapical and basal openings of the lumen, external and internal folds of the shaft, and base. The functional roles of these components in prey capture are proposed.     

Gaschromatographische Untersuchungen an elektronenbestrahlten Fetten

Zusammenfassung Untersuchungen über die chemischen Veränderungen in Fetten, die mit 100 Mrad bestrahlt wurden, ergaben, daß Verbindungen mit mittelkettigen Fettsäuren entstehen. Neben einer Abspaltung endständiger Methylgruppen tritt besonders eine Trennung der mittelständigen C-C-Bindungen auf, wodurch gesättigte und ungesättigte C₆- bis C₁₁-Bruchstücke nachweisbar werden. Die Doppelbindungen selbst sind relativ stabil, doch werden die der Doppelbindung benachbarten C-C-Einfachbindungen bevorzugt gespalten. Neben der Bildung von Fettsäuren findet auch eine solche von Carbonylverbindungen statt. Mehr als 20 verschiedene Ketone und Aldehyde konnten gaschromatographisch nachgewiesen werden. Die Aufspaltung der Ester-C-O-C-Bindung ist meist von einer Zerstörung der Fettsäurekette begleitet, wodurch Carbonylverbindungen mit 6 bis 12 C-Atomen entstehen. Relativ große Mengen von ungesättigten C₉-Ketonen und geringe Menge von Ketonen mit mehr als 13 C-Atomen werden in bestrahltem Tripalmitin sowie in bestrahlter Palmitinsäure gefunden. In ungesättigten Ölen treten diese Verbindungen nicht auf, dagegen enthalten diese mehr C₁₁-und C₁₂-Ketone.

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Summary Experiments on the chemical transformation of fats irradiated at 100 Mrads have shown the formation of fatty acid, median-branched bonds.Besides a separation of terminal branchings of methyl groups appears more particularly a scission of the median branchings C-C, following which saturated and unsaturated fragments from C₆ to C₁₁ have been made apparent. The double bonds themselves are relatively stable, while the single bonds adjacent to the double one, are in majority separated. Aside from the formation of fatty acids occurs also the formation of carbonyl bonds.More than 20 different ketones and aldehydes have been detected by gas chromatography. The scission of the bond ester-C-O-C is generally accompanied by a destruction of the fatty acid chain, following which appears the carbonyl bonds, with 6 to 12 atoms of carbon.Relatively great quantities of unsaturated C₉ ketones and small quantities of ketones with more than 13 atoms of carbon have been found in irradiated tripalmitin and in irradiated palmitic acid. In unsaturated oils these compounds are not found, but, on the other hand these oils have a greater content in C₁₁ and C₁₂ ketones.

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Résumé Des expériences sur les transformations chimiques des matières grasses, irradiées à 100 Mrad, ont montré la formation de liaisons à branchements médians d'acides gras.A côté d'une séparation de branchements terminaux de groupes méthyles, apparait en particulier une scission des branchements médians C-C, à la suite de laquelle des fragments saturés et non saturés de C₆ jusqu'à C₁₁ ont été mis en évidence. Les liaisons doubles mêmes sont relativement stables, cependant les liaisons simples, voisines à la liaison double, se trouvent en prédominance séparées.A côté de la formation d'acides gras, la formation de liaisons carbonylées a également lieu.Plus de 20 différents cétones et aldéhydes ont pu être mis en évidence par la chromatographie en phase gazeuse. La scission de la liaison ester-C-O-C-est généralement accompagnée d'une destruction de la chaîne d'acide gras, à la suite de laquelle naissent les liaisons carbonylées de 6 à 12 atomes de carbone.Des quantités relativement grandes des cétones C₉ non saturés et de petites quantités de cétones avec plus de 13 atomes de carbone ont été trouvées dans la tripalmine irradiée, ainsi que dans l'acide palmitique irradié. Dans les huiles non saturées, ces combinaisons ne se trouvent pas, par contre ces huiles contiennent davantage de cétones C₁₁ et C₁₂.

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mit 3 Fig.     

Metallic colloids in molten salts

Gold, silver, and silver iodide sols were prepared in mixed nitrate melts. Electron micographs of the gold and silver sols show particles smaller than 1 micron. The gold sols exhibit conventional absorption and scattering spectra. Both gold amid silver sols show unusual stability.     

Effects of chronic renal disease on the transport of vitamin A in plasma and urine of dogs

OBJECTIVE: To determine plasma and urine concentrations of retinol, retinyl esters, retinol-binding protein (RBP), and Tamm-Horsfall protein (THP) in dogs with chronic renal disease (CRD). ANIMALS: 17 dogs with naturally developing CRD and 21 healthy control dogs. PROCEDURE: A diagnosis of CRD was established on the basis of clinical signs, plasma concentrations of creatinine and urea, and results of urinalysis. Concentrations of retinol and retinyl esters were measured by use of reverse-phase high-performance liquid chromatography. Concentrations of RBP and THP were measured by use of sensitive ELISA systems. RESULTS: Dogs with CRD had higher plasma concentrations of retinol, which were not paralleled by differences in plasma concentrations of RBP. Calculated ratio of urinary total vitamin A (sum of concentrations of retinol and retinyl esters to creatinine concentration) and ratio of the concentration of urinary retinyl esters to creatinine concentration did not differ between groups. However, we detected a significantly higher retinol-to-creatinine ratio in the urine of dogs with CRD, which was paralleled by a higher urinary RBP-to-creatinine ratio. Thus, in dogs with CRD, the estimated fractional clearance of total vitamin A, retinol, and RBP was increased. Furthermore, dogs with CRD had a reduced urinary THP-to-creatinine ratio. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study documented that CRD affects the concentrations of retinol in plasma and urine of dogs. Analysis of the data indicates that measurement of urinary RBP and urinary THP concentrations provides valuable information that can be helpful in follow-up monitoring of dogs with CRD.     

Neurologic complications after melarsomine dihydrochloride treatment for Dirofilaria immitis in three dogs

Melarsomine dihydrochloride is highly effective against both sexes of adult and L5 Dirofilaria immitis. Common adverse reactions include injection site irritation and reluctance to move. Neurologic complications associated with i.m. injection of melarsomine dihydrochloride for treatment of heartworm disease in 3 dogs are described. Different degrees of neurologic complications have been identified; the pathophysiologic features are unknown. It is speculated that the compound migrates out of the injection site via fascial planes and causes an ascending inflammation along nerve roots. The resulting extradural cord compression secondary to extensive inflammation and necrosis of epidural fat could induce a variety of neurologic deficits. Alternatively, inappropriate injection technique may result in direct contact of melarsomine with neural tissue. A heightened awareness of proper injection technique might prevent the development of most neurologic complications.     

Use of rocuronium for endotracheal intubation of North American Gulf Coast box turtles

OBJECTIVE: To determine whether rocuronium, a reversible neuromuscular blocking agent, would provide safe, short-term immobilization to facilitate endotracheal intubation in turtles. DESIGN: Prospective study. ANIMALS: 30 healthy adult Gulf Coast box turtles. PROCEDURE: Turtles were given rocuronium, and responses were recorded every 3 minutes. Times to onset of effects, intubation, and recovery were recorded and analyzed for associations with dose and patient characteristics to determine an optimal dose range. Neostigmine and glycopyrrolate were given to augment recovery from neuromuscular blockade. RESULTS: Rocuronium administered at a dose of 0.25 to 0.5 mg/kg (0.11 to 0.23 mg/lb), IM, permitted intubation; lower doses were not effective. Mean +/- SD time to loss of the palpebral reflex was 6.4 +/- 4.0 minutes, and mean time to intubation was 9.2 +/- 6.4 minutes. Mean time to return of the palpebral reflex was 44 +/- 13.2 minutes, and mean time to walking was 55 +/- 16.6 minutes. Time to onset of effects was not associated with dose, but recovery times were prolonged with higher doses of rocuronium. Cardiac arrhythmias were observed in 13 (43%) turtles. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of rocuronium at a dose of 0.25 to 0.5 mg/kg is a safe and effective adjunct to general anesthesia in Gulf Coast box turtles. Because rocuronium does not provide any analgesic or sedative effects, the duration of neuromuscular blockade without anesthesia should be minimized to avoid undue distress.