[Growth of Octopus maya (Mollusca: Cephalopoda) of the Yucatan coast, Mexico: a long-term analysis]. / Crecimiento del pulpo Octopus maya (Mollusca: Cephalopoda) de la costa de Yucatán, México: un análisis de largo plazo.

Growth of the octopus (Octopus maya) off Yucatan (Mexico) was estimated from a long-term study (seven years) by the length-based methods ELEFAN, PROJMAT and SLCA. Some 19,251 octopuses with a range of mantle length between 50 and 240 mm were sampled from commercial landings in 1983-1987, 1989 and 1992. The jackknife technique was applied to deal with uncertainty in growth estimates resulting from chance variations in sampling design. The growth index phi' was used for comparative purposes. Results differed markedly among methods: ELEFAN produced parameter estimates within the range reported in the literature, whereas PROJMAT and SLCA showed problems to converge in an optimum combination of parameters, and tended to underestimate them. Jackknife analysis revealed very low intraannual variability in phi' but high variability among years, especially when applying PROJMAT. No significant differences were found in precision parameters--percent error and coefficient of variation--among methods. Estimates of phi' derived by ELEFAN varied between 4.19 and 5.23 and agreed with those reported in the literature (between 4.25 and 4.91), whereas PROJMAT and SLCA estimates were significantly lower. We suggest the use of ELEFAN, together with jackknife, to estimate growth parameters of Octopus maya.

[Trophic range of tilapia Oreochromis aureus (Perciformes: Cichlidae) in Infiernillo dam, Michoacán-Guerrero, Mexico]. / Espectro trófico de la tilapia Oreochromis aureus (Perciformes: Cichlidae) en la presa Infiernillo, Michoacán-Guerrero, México.

The trophic spectrum of tilapia Oreochromis aureus (Steindachner 1864), was determined by stomach content analysis in 153 organisms collected during 1993 in Michoacán-Guerrero, México. The feeding status of the fish at the time of observation was evaluated by the examination of fat surrounding the gut, gastric replection and the condition coefficient. The quantitative evaluation of the food items was carried out by the combination of the following analysis: Frequency of Occurrence, Volumetric Method, Volumetric Mean Index and Relative Importance Index. Diet consisted of: detritus and vascular plant residues as a primary food; unicellular algae as secondary food; and remains of insects and fish, graminean seeds, filamentous algae, cladocerans, ostracods, rotifers and copepods as occasional food. We detected a difference in food preferences between juveniles and adults and a variation in the consumption proportions of some food items during the rainy and dry seasons. Thus, we concluded that O. aureus is an omnivorous species with preference for detritus and vascular plant remain. Feeding seems to be determined by the abundance of food items found in the habitat and adults showed a trend to eat only detritus. Feeding does not seem to be a limiting factor in the development of the tilapia in Infiernillo dam.

Psychological variables associated with outcome of spinal cord stimulation trials.

Study Design. This is a prospective study designed to identify psychological factors associated with response to spinal cord stimulation (SCS) trial. Summary of Background Data. In most centers, implantation of a permanent SCS system is preceded by a trial of a temporary stimulating electrode. Yet, even among those who report greater than 50% pain reduction during trial, a significant number of these patients fail to receive long-term pain relief from the permanent system. Because mood disorders can alter pain report, we hypothesized that refined definition of the psychological factors associated with SCS success could result in improved selection of candidates for SCS trial. Methods. The study sample consisted of 43 chronic pain patients (72% failed back surgery syndrome, 77% with radiating low back pain) who were referred for implantable pain management. Following psychological evaluation, patients were admitted for a three-day inpatient trial of SCS. Report of at least 50% pain relief during trial was considered a success and resulted in implantation of the permanent stimulator. Patients were retrospectively divided into two groups: those whose pretrial pain was relieved by at least 50% ("success") and those whose pain was relieved by less than 50% ("failure"). Results. Univariate t-test or chi-square analyzes of group means of an extensive psychological battery followed by a global, stepwise logistic regression model of trial outcome was used to analyze between group results of a psychological test battery. MMPI depression and mania subscores were found to be significantly elevated among the two outcome groups (p = 0.007 and 0.025, respectively). Conclusions. Patient mood state is an important predictor of trial outcome. Specific indicators of SCS trial outcome are the MMPI depression and mania subscale scores with successful trials being associated with individuals who are less depressed and have higher energy levels.

Genotypic and phenotypic analysis of Salmonella strains associated with an outbreak of equine neonatal salmonellosis.

Isolates of Salmonella choleraesuis serotype ohio (S. ohio) recovered during an outbreak of equine neonatal salmonellosis on a Thoroughbred farm were compared with isolates of the same serotype from various animal, feed and environmental sources. Biochemical profiles, antimicrobial susceptibility patterns, phage susceptibility, plasmid profiles, restriction endonuclease analysis and ribotyping were used to compare relatedness of the strains. A total of 46 outbreak and non-outbreak associated isolates of S. ohio were studied. Differences in antimicrobial susceptibility patterns, phage susceptibility and plasmid profiles were useful for differentiating outbreak isolates from other equine isolates as well as bovine, porcine and some poultry isolates. Feed and other poultry isolates, most in geographic proximity to the outbreak, were indistinguishable from outbreak isolates by any of the methods employed. Investigative studies on the farm along with results of genotypic and phenotypic analysis of isolates suggested that contaminated feed was the most likely source of Salmonella in this outbreak.

The Rey AVLT recognition memory task measures motivational impairment after mild head trauma.

The effect of financial incentives on Rey AVLT recognition memory performance was assessed. Clinically referred mild head trauma (MHT) patients with financial incentives were compared to patients with neurologically documented brain dysfunction who did not have financial incentives. The MHT group was subdivided into a group with strong performance on a measure of motivation, the Portland Digit Recognition Test (PDRT), and a group with weak performance on the PDRT. The resulting three groups were equated on Rey AVLT acquisition, age, and education. The MHT subgroup with poor PDRT scores also was significantly impaired on recognition memory. In the total sample the prevalence of recognition scores of less than 6 correct was 27% in the MHT group and 5% in the brain dysfunction group. We conclude that severe Rey AVLT recognition memory impairment likely reflects motivation to exaggerate deficits, at least in MHT patients with no neurological evidence of brain injury.

An outbreak of equine neonatal salmonellosis.

An outbreak of salmonellosis in foals occurred on a large Thoroughbred farm in California. Only foals less than 8 days of age exhibited clinical signs, which included depression, anorexia, and diarrhea. Three foals died from septicemia. The agent responsible was Salmonella ohio, which is rarely involved in salmonellosis in horses. During the course of the outbreak, S. ohio was isolated from 27 of 97 mares (27.8%) and 34 of 97 foals (35.1%). Mares were the presumed source of infection for foals. The absence of clinical signs in mares allowed for increased exposure of foals through environmental contamination. Although foals continued to become infected after strict control measures were adopted, none became ill. Salmonella serotypes of seemingly low virulence can produce serious disease outbreaks.

Recovery of Streptococcus agalactiae and Staphylococcus aureus from fresh and frozen bovine milk.

Three hundred seventy-three milk samples were screened for Streptococcus agalactiae and Staphylococcus aureus. After sample storage at -20 C for 23 days, the frequency of Str agalactiae isolation increased 2.50 times. The frequency of S aureus isolation increased 1.48 times in the same interval. Increases in the proportion of these isolates were highly significant (P = 0.000006 and 0.0001, respectively). Results of the study indicate that optimal procedures for microbiological testing for these mastitis pathogens may include preculture freezing. The magnitude of the increase in the proportion of isolates indicates the existence of an important population of infected cattle shedding bacteria at concentrations not detected by use of standard microbiological techniques.

[Role of polyphenols in the low nutritive value of Vicia faba]. / Papel de los polifenoles en el bajo valor nutritivo de la Vicia faba.

The inclusion of field bean (Vicia faba) in diets for growing experimental animals, reduced their growth performance in a similar way as compared with controls fed a casein diet, with 0.2% tannic acid. Hydroalcoholic extracts or isolated tannins obtained from Vicia faba seeds, decreased the intestinal transport of D-glucose. The addition of 0.05, 0.1 or 0.2% of tannic acid to the perfusion solutions containing D-glucose proportionally diminished the intestinal uptake of sugar according to its poliphenolic content. It has been postulated that polyphenols reduce, at least partially, the nutritive value of legumes, by altering monosaccharide absorption. Other constituents, however, could also be involved.

Papel de los polifenoles en el bajo valor nutritivo de la Vicia faba / Role of polyphenols in the low nutritive value of Vicia faba

La inclusión de harina de habas (Vicia faba) en la dieta de animales de experimentación produce un retardo en el crecimiento, semejante al inducido por la adición de 0.2% de ácido tánico en dietas control de caseína. Tanto los extractos hidroalcohólicos obtenidos a partir de semillas de havas. Asimismo, la presencia de ácido tánico al 0.05, 0.1 y 0.2% en las soluciones de glucosa, disminuye proporcionalmente la absorción de ésta por el intestino. Los resultados en cuestión parecen sugerir que los polifenoles afectan, al menos parcialmente, el valor nutritivo d ela leguminosa (Vivia faba), si bien otros componentes d elas mismas también podrían estar involucrados