Noise and the quality of sleep in two hospitals in the city of Belo Horizonte, Brazil.

Male patients of two hospitals in Belo Horizonte completed a questionnaire during an interview on the day of discharge in order to evaluate sleeping conditions related to noise during the previous night and were retested 24 h later. Patients had a worse perception of sleep at the noisier hospital, the University Hospital of the Federal University of Minas Gerais (N = 13), whose internal mean nocturnal noise level was Leq = 53.7 db(A), than at the quieter hospital, Baleia (N = 22), whose internal mean nocturnal noise level was Leq = 45.5 db(A). Noise was the only sleep-disturbing factor which was statistically significant.

Noise and the quality of sleep in two hospitals in the city of Belo Horizonte, Brazil

Male patients of two hospitals in Belo Horizonte completed a questionnaire during an interview on the day of discharge in order to evaluate sleeping conditions related to noise during the previous night and were retested 24 h later. Patients had a worse perception of sleep at the noisier hospital, the University Hospital of the Federal University of Minas Gerais (N = 13), whose internal mean nocturnal noise level was Leq = 53.7 db(A), than at the quieter hospital, Baleia (N = 22), whose internal mean nocturnal noise level was Leq = 45.5 db(A). Noise was the only sleep-disturbing factor which was statistically significant.

Effect of external carbon dioxide concentration on electric organ dischargge frequency by the gymnotiform fish Apteronotus albifrons

A model is described for the instantaneous frequency (F) of electric organ discharge in Apteronotus albifrons: F=H/(aH + b), where a and b are linear parameters and H, hydrogen ion concentration, pH from 7.10 to 4.89 was modified by increasing external carbon dioxide concentrations. With the increase in pH from 5.17 to 7.40, corresponding to a decrease of carbon dioxide concentration, the equation was as follows: F=(logH)/(a ,log H=b). The model search consisted of the adjustment of a simple linear regression using fucntion transformation for the most adequate residue analysis by the Durbin-Watson test. The parallelism was checked by comparing regression lines with homogeneous variances and using other tests for non-homogeneous variances

Effect of temperature on the reproduction of the snail Biomphalaria glabrata.

1. The reproduction of the snail Biomphalaria glabrata, one of the intermediate hosts of Schistosoma mansoni, was evaluated under laboratory conditions by measuring egg production, number of ovipositions, number of eggs per oviposition, and hatching rate using a Latin square design with five different temperature treatments. This permitted the elimination of occasional variation in oviposition due to manipulation or a priori group. 2. Egg production and spawning rates were higher at temperatures between 20.0 and 27.5 degrees C than at 17.5 degrees C. Number of eggs per spawning and hatching rate did not vary with temperature. 3. During a 3-day adaptation phase, a short-term thermal effect appeared in which some indices of reproductive rates differed significantly from those of the experimental phase.

Influence of experimental illumination and seasonal variation on crossbreending mating in the snail Biomphalaria

The crossbreeding activities of the Schistosoma mansoni vector snail Biomphalaria glabrata were counted in a laboratory aquarium throughout the year under two regimes of 12h light: 12h dark from 7 A., M. to 10 P. M. Mating increased significantly in Authmn and Winter and just missed a significant inverse correlation with temperature and a direct one with locomotion. Other similar experiments were carried out to compare mating under various ilumination conditions in complete daily cycle measurements. Mating counts decreased under the regimes which submited snail to a total exposure of 12h light and 12 dark during a daily cycle in the following sequence: 12h light: 12h dark alternating hourly with light gradient, 12h light: 12h dark, 1h light: 1h dark and 12h dark: 12h light. Under two constant illuminations, the mating scored less than under the previous conditions, except under 12h light. Under darkeness the mating count was lower than light conditions. There was no way to differentiate the night and day rhythms of mating on different days in each regime, except for mating under 12h light: 12 dark alternating with light gradient, constant dark and 12h dark: 12h light conditions. Mating increased in certain light and temperature conditions, in wich the intensities, should have an optimum value

Influence of experimental illumination and seasonal variation on crossbreeding mating in the snail Biomphalaria glabrata.

The crossbreeding activities of the Schistosoma mansoni vector snail Biomphalaria glabrata were counted in a laboratory aquarium throughout the year under two regimes of 12h light: 12h dark from 7 A. M. to 10 P. M. Mating increased significantly in Autumn and Winter and just missed a significant inverse correlation with temperature and a direct one with locomotion. Other similar experiments were carried out to compare mating under various illumination conditions in complete daily cycle measurements. Mating counts decreased under the regimes which submitted snail to a total exposure of 12h light and 12h dark during a daily cycle in the following sequence: 12h light:12h dark alternating hourly with light gradient, 12h light:12h dark, 1h light:1h dark and 12h dark:12h light. Under two constant illuminations, the mating scored less than under the previous conditions, except under 12h dark:12h light. Under darkness the mating count was lower than under light conditions. There was no way to differentiate the night and day rhythms of mating on different days in each regime, except for mating under 12h light:12h dark alternating with light gradient, constant dark and 12h dark:12h light conditions. Mating increased in certain light and temperature conditions, in which the intensities should have an optimum value.

Electric organ discharge frequencies from two weakly electric gymnotiform fish exposed to carbon dioxide, conductivity and pH changes.

Electric organ discharge (EOD) frequencies of two weakly electric, gymnotiform, water-breathing fish decreased abruptly with an increase in carbon dioxide concentration and decrease in pH, caused by bubbling carbon dioxide in water. After carbon dioxide bubbling ceased, the recovery of EOD frequencies was linear with the return toward normal pH, but with a lag, so that the frequency was below normal even 24 h after pH returned to the control value. In another series of experiments, blood collected by cardiac puncture after carbon dioxide bubbling was cut off showed pH values below normal, indicating a lag in the blood buffering capability. Conductivity of the water did not influence EOD frequency.

Electric organ discharge rhythms and social interactions in a weakly electric fish, Rhamphichthys rostratus, (Rhamphichthyidae, Gymnotiformes) in an aquarium.

Pairs of fish of the South American "pulse" species (of 40-100 Hz frequency), Rhamphichthys rostratus, were studied for position and motor behaviour in tanks fitted with hollow tiles on the bottom. Each pair consisted of a larger and a smaller fish. The larger fish in each pair seemed to be territorially dominant and tended to stay inside the tiles more than the smaller one; the smaller fish moved around more than the larger one. All animals stayed more frequently inside the tiles during the daytime period. During rainy weather, or when each fish was studied separately rather than in pairs, the animals stayed more frequently inside the tiles, usually resting for long periods of time. The larger fish in each pair spent more time on its side than the smaller one, showing a diurnal rhythm in the amount of time spent in this position, whereas no such rhythm was observed for the smaller fish. The acceleration of the frequency of electric organ discharges (EOD), called "jump", and social interaction were also recorded. Smaller fish showed more jump activity than larger ones. The occurrence of jumps was related to the anti-parallel and tandem position of the two fish, seemed to increase with time of settled position and favourable temperature, was more likely to occur when the individuals were quite close to each other and to decrease during rainy weather.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of seasonal temperature and experimental illumination on reproductive rate in the snail Biomphalaria glabrata.

1. Reproduction in the snail Biomphalaria glabrata, a vector of Schistosoma mansoni, was measured by egg production and other parameters such as number of clutches, eggs per clutch and egg hatching, under laboratory conditions. 2. Reproductive rates were highest in terms of total number of eggs, clutches and hatching under constant illumination, followed by conditions similar to the natural rhythm of illumination. The greatest reduction in reproduction occurred in constant darkness. In summary, reproductive rate was dependent on both the intensity of absolute illumination and the schedule of illumination exposure. 3. Seasonal variation in reproductive rate appeared to vary inversely with local temperature in Belo Horizonte, situated in a tropical zone (latitude 20 S) owing probably to a temperature preference of 20 to 25 degrees C by the snail. The highest reproductive rates occurred in winter, except for the parameter eggs per clutch which was maximal in autumn. Snail reproduction appeared to be most reduced during summer. There was no linear correlation between reproductive rate and temperature.

Temperature influence and social interaction on the frequency of electric organ discharges in Rhamphicthys rostratus

The frequency of electric organ discharges (EOD) of a gymnotiform fish of "pulse" frequency (40-100 Hz) from South America - Ramphicthys rostratuswas studied. The animals were settled in pairs in a aquarium and thus observed: variation in EOD frequency had at least two components: one more positively correlated with temperature, another less positively correlated due to social interaction.

A frequência de descargas do órgão elétrico {DOE) de um peixe gymnotiforme de freqüência "em pulso" (40-100 Hz) da América do Sul - Rhamphicthys rostratus - foi estudada. Os animais foram colocados aos pares em aquários e depois observados: variação da freqüência do DOE tinha sido menor duas componentes: uma mais positivamente correlacionada devido a interação social.

[Dualist nature of cutaneous pain. Review of the literature]. / Natureza dualista da dor cutanea. Revisão da literatura.

The double nature of the cutaneous pain is evident since the peripheral level, projecting in different structures of the central nervous system. In certain levels their ways converge, in other ones they diverge. Their characteristics appear since the stimulation, going beyond through different properties of receptive fields, and reaching particular associated responses. They seem also different in the ways of blocking and have interactions between them and with the dorsal column and lemniscal system, that conveys the sensibility of fine touch.

Natureza dualista da dor cutanea: revisao da literatura. / Dualist nature of cutaneous pain:review of the literature

A natureza dualista da dor cutanea aparece desde o nivel periferico, projetando-se em diferentes estruturas no sistema nervoso central. Em certos pontos ha convergencia, em outros ha divergencia das vias. Suas caracteristicas aparecem desde as formas de estimulacao, passando pelas propriedades diversas dos campos receptivos, e associadas a respostas particulares. Parecem tambem diferentes nas formas de bloqueio e exercem interacoes entre si e com os sistemas da coluna dorsallemniscal, que conduz a sensibilidade do tato fino

Somatic sensory cortical regions of the agouti, Dasyprocta aguti.

The localization and organization of primary (SmI) and secondary (SmI) somatic sensory cortical regions in agoutis, have been studied with micro- and macroelectrode-evoked potential techniques. For SmI, the mean surface area determined using microelectrodes was 13% smaller than that obtained using macroelectrodes. The location and organization of SmI are similar to those of other rodents: the largest representations were those of the vibrissae, the perioral regions and the first digit of the hand. As in some other animals, SmII is related to both sides of the body. It shows excellent somatopic differentiation and was located lateral and posterior to SmI, in relation to which it is arranged as a reduced mirror image. The area of SmII represents 31% of that of SmI in agoutis. The large size of the forepaw representation in SmI is reflected in SmII, that of the face representation is not; this agrees with similar findings from several other species. SmI was completely mapped using light touch stimuli, and contains many projections from vibrissae and hairs along with some proprioceptive projections. SmI overlaps with visual projections. SmII receives less light touch, vibrissae and hair projections than SmI, and it receives numerous deep mechanical and auditory projections. In SmII latencies were 10.96 msec for somesthetic and 13.39 msec for auditory stimuli; in SmI latencies were 13.25 msec for somesthetic and 39.80 msec for visual stimuli. One sulcus separates the SmI projections of the forelimb from those of the hindlimb, and another is often found marking the posterolateral boundary of SmII.

Origins of the spontaneous receptor potential in the tuberous organ in a mormyrid fish.

In an electroreceptor of a Mormyrid fish: 1. The correlations between the number of sensory cells in each receptor organ and the mode of the intervals of time between receptor potentials are not significant within the temperature ranges of 20.0-26.0 degrees C, 20.5-21.5 degrees C, 22.0-23.0 degrees C and are significant at a level of 4.9% within 25.0-26.0 degrees C. 2. The correlations between the mode of intervals of time between receptor potentials and temperature are significant at a level inferior to 1% for isolated receptor organs and also at a level of 5.8% for 21 different receptor organs from 9 different fishes.