O método potenciométrico na determinação do H+ trocável em solos

For the determination of exchangeable hydrogen ion in soils, the authors of the presente work made the extraction with normal calcium acetate solution that may have an initial pH between 7 and 8 without altering the amount of hydrogen ion extracted. The extraction was made by shaking 5,0 grams of air dry soil with 100 ml of normal calcium acetate solution, the pH of wich was ascertained to 7,0, 7,5 and 8,0 with acetic acid, in 250 mil conical flasks for 30 minutes in a Wagner shaker (30-40 rpm). The contents of the flasks were then, filtered. A 50 ml aliquot of each of the leachate was titrated with a 0,020 N NaOH solution and the volumes consumed sodium hydroxide were ploted against pH. The titration curves thus obtained showed to be straight lines between pH 8 and 9 and parallel to the curve obtained by the titration of the blank. Two ways of locating the end point of the titration showed to be possible: the use of a pHmeter or titrimeter or the use of phenolphtalein as indicator. When using a pH meter or a titrimeter, the end point may rest in any point between pH 8 and 9, and the volume of sodium hydroxide consumed is found by comparison with a similar curve obtained by the titration of the blank. When using phenolphtalein the calcium acetate solution must have a pH below 8.

Análise comparativa entre tipos de alimentação de Micrurus corallinus (Serpentes, Elapidae) em cativeiro

Micrurus corallinus (Merrem, 1820) kept in laboratory animal rooms swallow voluntarily various colubrid species. The most accepted species belong to the genera Sibynomorphus Fitzinger, 1843, Oxyrhopus Wagler, 1830 and Liophis Wagler, 1830. The voluntary feeding guaranteed resistance against pathogenic agents. The forced feeding was unsatisfactory due to stress resulting from handling, feeding frequency (30 days), susceptibility to pathogenic agents and high occurrence of pathologies.

Variação de peso e sobrevida de Micrurus corallinus sob diferentes condições de alimentação em biotério (Serpentes, Elapidae)

The weight variation in Micrurus corallinus (Merrem, 1820) during the first 60 days in laboratory animal rooms was very remarkable. This fact demonstrates the difficulty in adaptation of these animals to the captive environment. The weight loss was observed in animals under voluntary feeding as well as forced feeding. The survival rate was significantly higher in voluntarily fed animals. Sex differences were also observed with higher survival rates for males. Low survival rates were observed in both sexes under forced feeding.

Molt cycle of the natural population of Palaemonetes argentinus (Crustacea, Palaemonidae) from Los Padres Lagoon (Buenos Aires, Argentina)

The molt cycle of the natural population of Palaemonetes argentinus Nobili, 1901 from Los Padres Lagoon, Buenos Aires, Argentina, was studied in relation to age, sex, and environmental factors. A total of 1645 individuals (740 females, 539 males, and 366 juveniles) were collected and analyzed between December 1995 and December 1996. The results indicate that the sex ratio (males:females) remains around 1:1.4 throughout most of the year. The reproductive period extends from September until February (spring and summer), with maximum sexual activity in October and November. Two cohorts originated in the spring and in the summer were differentiated. Ovigerous females arrest their molt cycle during the intermolt period to restart it after oviposition. The duration of the intermolt period does not differ between adults and juveniles. Since the percentage of premolt individuals represents 60% of the total cycle, it was classified as a diecdysic cycle. Within the studied range of water temperatures, the observed variations in the span of the different stages, indicate that this factor does not alter the molt frequency. Like in the rest of decapods, the intermolt duration of P. argentinus is modified by ovarian maturation.

Descrição do ciclo reprodutivo de Donax hanleyanus (Bivalvia, Donacidae) no sul do Brasil

The changes in gonadal development in male and female of Donax hanleyanus Philippi, 1847 are described. Gonad development and spawning seasons were assessed by monthly sampling of population from Arroio Teixeira beach, southern Brazil. Histological examination of clams showed in the most of the adult population sampled that the spawning is practically continuous, without any period of sexual rest. There are two main periods of gametogenesis, in winter and in summer, being the degree of maturation longer in the latter. The water temperature is stimulant on gametes proliferation and spawning.

Oviposition behavior of wild Zabrotes subfasciatus (Coleoptera, Chrysomelidae) females deprived of the host Phaseolus vulgaris (Fabaceae)

The insects oviposition behavior is fundamental to study population dynamics, life history evolution, insect-plant and parasitoid-host interactions. Zabrotes subfasciatus (Boheman, 1833) females oviposition behavior in the presence and absence of a host is unknown. The main objective of this study was to describe in detail the oviposition behavior of host deprived or non-deprived females, and observe how the several situations of deprivation (days without host) influence oviposition. Six groups were assembled, three deprived of the host (for 2, 5 and 8 days) and three control groups (with host), each containing one newly-emerged couple (0-24h) of wild Z. subfasciatus, The non-deprived (control) groups received the hosts every day (5 bean seeds Phaseolus vulgaris (Fabaceae)) and the others were deprived for 2, 5 and 8 days, respectively. For each group 12 repetitions were made. Consequently, 12 couples were host deprived during two days, 12 couples were host deprived during five days and 12 couples were host deprived during eight days. When the seeds of the deprived groups were added the experiments started. There was a control group for each deprived group. The experiments and the insects were maintained at constant temperature 29 ± 2ºC and 70-80% relative humidity. At 15 minutes interval, the number of times the females manifested the different categories of behavior was observed (frequency). The behavior categories were: rest inside the box, locomotion, resource exploration (seeds), copulation and oviposition. The deprived females stayed most of the time in contact with the host to carry out oviposition, while the non-deprived (control) females spent most of the time at rest. This was observed in all the deprivation times. The results show that host deprivation influences the oviposition behavior of the studied species and also shows the flexibility in the oviposition strategies that these females present when the environment changes (absence and presence of resources)

Conservation status assessment of the amphibians and reptiles of Uruguay

The native species of amphibians and reptiles of Uruguay were categorized according to the IUCN Red List criteria. Out of 47 amphibian species, seven are listed as Critically Endangered (CR), five as Endangered (EN), one as Vulnerable (VU), three as Near Threatened (NT), and two as Data Deficient (DD); the remaining species are considered to be Least Concern (LC). Among the 64 species of reptiles evaluated, one is listed as Critically Endangered (CR), seven as Endangered (EN), two as Vulnerable (VU), one as Near Threatened (NT) and seven as Data Deficient (DD); the rest are considered to be Least Concern (LC). The use of these results as an additional criterion in the definition of protected areas in Uruguay will contribute towards the conservation of the aforementioned threatened species and their associated ecosystems.

Population ecology of the multivoltine Neotropical gall midge Eugeniamyia dispar (Diptera, Cecidomyiidae)

Our understanding of the population ecology of insect gallers is largely built on examples from temperate zones, but tropical and subtropical gallers may present distinct patterns of abundance and distribution across time. Eugeniamyia dispar Maia, Mendonça & Romanowski, 1996 is a multivoltine Neotropical cecidomyiid that induces spongy leaf galls on Eugenia uniflora (Myrtaceae). Galls were censused in the urban area of Porto Alegre, southern Brazil on six plants at two sites, for two years, at roughly weekly intervals. Overall 9,694 eggs, galling attempts and galls were counted. New galls continuously appear on developing leaves, but galls with live inducers are absent from June to at least early August. Galls on a same shoot develop synchronically, thus the shoot is probably the unit for oviposition. Given the also synchronic appearance of galls on different plants on a site, it seems midges can disperse and attack close-by plants. Gall cohorts varied in abundance by two orders of magnitude; there were more galls during summer than for spring and autumn, in a wave-like pattern. Host plant leaf production was seasonal, with low production during winter and cyclic production during the rest of the year. Perhaps because of this very variable pattern, gall abundance did not follow leaf production: this galler is not synchronised with its host at least during most of the year. This multivoltine gall inducer with "labile" galls, short development time, partially overlapping generations and low host synchronisation differs from the commonly studied species of the temperate regions providing a subject for ecological comparisons.

A new species of Leiostracus from Bahia, Brazil (Gastropoda, Pulmonata, Orthalicidae)

A remarkable new species of pulmonate snail was recently collected in a small Atlantic Rainforest fragment near the city of Canavieiras, state of Bahia, Brazil, an area known for a high diversity of land snails. It is described herein as Leiostracus fetidus sp. nov. and can be easily identified by its color pattern of irregular brown to black axial stripes on a white to yellow background, a reddish axial band "separating" the white peristome from the rest of the shell and a broad brown spiral band surrounding the umbilical region. Other diagnostic features include a relatively small size, a proto columellar fold and two very weak folds delimiting the basal region of the aperture. This discovery is a reminder of how little this fauna is known and also an alarm for proper conservation of these forest fragments.

Tratamento eclético da lepra: 20 anos de experiência

The author gives the clinical records of 20 patients, 14 of which were treated during 17 months, and the rest much less. The method used for treatment was the ecclectical — preferred by the A. since many years —, in which he associates electricity with minor surgery, chaulmestrol (pure or with 0.5 p. c. iodine or 4 p. c. creosote) and other auxilliary curative agents. The chaulmoogra derivatives were used daily as nostrils tamponage (2 p.c. mentholated or thymolated ester), periodically by injections inside the enlarged lymph nodes and nerve abscesses, and twice weekly by subcutaneous infiltrations (MUIR method) 5 c.c. each, and chaulmoogra soap tablets per os. The galvanocauterisation session was once per week, on active leprotic lesions, followed by painting with 30 p. c. trichloracetic acid solution. All 20 patients were bacilliferous before treatment, and became stronger positive after some months treatment. At the end 14 negativated and 6 remained positive and sometimes bacilli being very scanty. 16 out of 20 gave interesting serological reactions, viz.: Wassermann, Stern, Kahn. Rubino, Witebsky and Gaté (Formol-gel) positive in 5; Stern, Rubino. Witebsky and Gaté positive and Wassermann and Kahn negative in 2; Stern. Kahn, Witebsky and Gaté positive and Wassermann anticomplementary in 1; Wassermann. Stern, Kahn, Rubino and Gaté negative in 1. in the beginning, and a few months later Stern. Witebsky and Gaté becoming positive; Stern. Rubino. Witebsky and Gaté positive and anticomplementary W. in 1; Stern, Witebsky and Gaté positive and Wassermann. Kahn and Rubino negative in 1; Witebsky and Gaté positive and Wassermann, Stern, Kahn and Rubino negative in 1; Witebsky 3 times anticomplemantary and strongly positive Gaté in 1; Wassermann and Gaté positive in 1; Stern and Rubino positive in 1 and Stern test negative in one. In 7 cases high Formol-gel were associated with a high sedimentation index. Many cases had very high S.I. being a false measure of the severity of the disease; others remained very high notwithstanding the great improvement of the disease. All patients with more than 12 months treatment became practically symptom free. Lepra reaction amongst them was rare and always started by embolic rash, being controlled by destruction of such skin lesions by galvanocauterisation. In a few cases the lepromata infiltrated with "Subintrol" (a 3 p. c. special chaulmoogra soap prepared by Dr. ASTROGILDO MACHADO) were completely destroyd and never relapsed. In October 1946 Dr. ERNEST MUIR saw here a few cases treated by the author's method and suggested the combination of Diasone with galvanocauterisation which is being done now with satifactory results. The second part of this paper, reporting many leprosy cases treated by the so-called ecclectical method, which are symptom free and negativated since five to ten years, will be published as soon as the sulfone-therapy be summarised in some reliable scientific report to be compared with.

Plancto e hidrobiologia sanitária de tanques tropicais com dáfnias e rotíferos

The engineers of the modern University City are constructing a graceful bridge, named PONTE OSWALDO CRUZ, that crosses a portion of the Guanabara Bay (Fig. 1). The work at west pillar stopped for 3 years (The concret structure in Est. 1). As it will be seen from n.º 1 — 5 of the fig. 1, Est. I, the base of the structure will have five underground boxes of reinforcement, but, to-day they are just like as five uncovered water ponds, until at present: May 1963. (Est. I — fig. 3, n.º 3 — pond n.º 3; A. — old level of the water; B.— actual level of the water; c.— green water; E.— mass of bloom of blue algae Microcystis aeruginosa). Soon after SW portion, as 5 cells in series, of the pillar abutments, and also the NE portion nearly opposite in the Tibau Mount will be filled up with earth, a new way will link Rio City and the University City. We see to day Est. I, fig. 1 — the grasses on the half arenous beach of the Tibau Point. These natural Cyperaceae and Gramineae will be desappear because of so a new road, now under construction, when completed will be 33 feet above the mean sea level, as high as the pillar, covering exactly as that place. Although rainfall was the chief source of water for these ponds, the first water (before meterorological precipitations of whatever first rain it might fall) was a common tap water mixed with Portland Cement, which exuded gradually through the pores of the concret during its hardenning process. Some data of its first cement water composition are on the chemical table, and in Tab. n.º 4 and "Resultado n.º 1". The rain — receiving surface of each pond were about 15 by 16 feet, that is, 240 square feet; when they were full of water, their depth was of 2 feet 3", having each pond about 4,000 gallons. Climatic conditions are obviously similar of those of the Rio de Janeiro City: records of temperature, of precipitation and evaporation are seen on the graphics, figs. 2, 3, 4. Our conceptions of 4 phases is merely to satisfy an easy explanation thus the first phase that of exudation of concrete. We consider the 2nd. phase formation of bacterian and cyanophycean thin pellicel. 3rd. phase - dilution by rains, and fertilisation by birds; the 4th phase - plankton flora and fauna established. The biological material arrived with the air, the rains, and also with contaminations by dusts; with big portion of sand, of earth, and leaves of trees resulted of the SW wind actions in the storming days (See - Est. I, fig. 3, G. - the mangrove trees of the Pinheiro Island). Many birds set down and rest upon the pillar structure, its faeces which are good fertilizers fall into the ponds. Some birds were commonly pigeons, black ravens, swallows, sparrows and other sea mews, moor hens, and a few sea birds of comparatively rare occurence. We get only some examples of tropical dust contaminated helioplankton, of which incipient observations were been done sparcely. See the systematic list of the species of plankters. Phytoplankters - Cyanophyta algae as a basic part for food of zooplankters, represented chiefly by rotiferse, water-fleas Moinodaphnia and other Crustacea: Ostracoda Copepoda and Insecta: Chironomidae and Culicidae larvae. The polysaprobic of septic irruptions have not been done only by heating in summer, and, a good reason of that, for example: when the fifth pond was in polysaprobic phase as the same time an alike septic phase do not happened into the 3rd. pond, therefore, both were in the same conditions of temperature, but with unlike contaminations. Among the most important aquatic organisms used as indicatiors of pollution - and microorganisms of real importance in the field of sanitary science, by authorities of renown, for instance: PALMER, PRESCOTT, INGRAM, LIEBMANN, we choose following microalgae: a) The cosmopolite algae Scenedesmus quadricuada, a common indicator in mesosaprobio waters, which lives between pH 7,0 and it is assimilative of NO[3 subscripted] and NH[4 subscripted]. b) Species of the genus Chlamydomonas; it is even possible that all the species of theses genus inhabit strong-mesosaprobic to polysaprobic waters when in massive blooms. c) Several species of Euglenaceae in fast growing number, at the same time of the protozoa Amoebidae, Vorticellidae and simultaneous with deposition of the decaying cells of the blue algae Anacystis cyanea (= Microcystis) when the consumed oxygen by organic matter resulted in 40 mg. L. But, we found, among various Euglenacea the cosmopolite species (Euglena viridis, a well known polysaprobic indicatior of which presence occur in septic zone. d) Analcystis cyanea (= M. aeruginosa) as we observed was in blooms increasing to the order of billions of cells per litter, its maximum in the summer. Temperatures 73ºF to 82ºF but even 90ºF, the pH higher than 8. When these blue algae was joined to the rotifer Brachionus calyflorus the waters gets a milky appearance, but greenished one. In fact, that cosmopolite algae is used as a mesosaprobic indicator. Into the water of the ponds its predominance finished when the septic polysaprobic conditions began. e) Ankistrodesmus falcatus was present in the 5th pond from 26the. April untill the 26th July, and when N.NH[4 subscripted] gets 1.28 mg. L. and when chlorinity stayed from 0.034 to 0.061 mg. L. It never was found at N.NH[4 subscripted] higher than 1 mg. L. The green algae A. falcatus, an indicatior of pollution, lives in moderate mesosaprobic waters. f) As everyone knows, the rotifer eggs may be widely dispersed by wind. The rotifer Asplanchna brightwelli in our observation seemed like a green colored bag, overcharged by green cells and detritus, specially into its spacious stomach, which ends blindly (the intestine, cloaca, being absent). The stock of Asplanchna in the ponds, during the construction of the bridge "PONTE OSWALDO CRUZ" inhabits alkaline waters, pH 8,0 a 8,3, and when we observed we noted its dissolved oxygen from 3.5 to 4 mg. L. In these ponds Asplanchna lived in 0,2 P.PO[4 subscripted]. (Remember the hydobiological observations foreign to braslian waters refer only from 0.06 to 0,010 mg. L. P.PO[4 subscripted]; and they refer resistance to 0.8 N.NH[4 subscripted]). By our data, that rotiger resist commonly to 1.2 until 1.8 mg. L.N.NH[4 subscripted]; here in our ponds and, when NO[2 subscripted] appears Asplanchna desappears. It may be that Asplanchna were devoured by nitrite resistant animals of by Culicidae or other mosquitoes devoured by Due to these facts the number and the distribution of Asplanchna varies considerabley; see - plates of plankton successions. g) Brachionus one of the commonest members of class Rotatoria was frquently found in abundance into the ponds, and we notice an important biological change produce by the rotifer Brachonus colyciflorus: the occurence of its Brachionus clayciflorus forms pallas, is rare in Brazil, as we know about this. h) When we found the water flea MOinodaphnia we do not record simultanous presence of the blue algae Agmenellun (= Merismopedia).

Competitive interactions between species of freshwater snails: I. Laboratory: Ia. General methodology

For the development of laboratory experiments on the competitive interacitons between freshwater snail populations, special snail rooms were set up in the main building of the Research Center "Aggeu Magalhães". In the current paper, the first of a series on this subject, the general methodology of the laboratory work is described in detail. Using indoor cement channels in which a uniform seminatural environment was created, interactions of freshwater snail populations can be studied with minimal interference of the usual variables. Controlled indoor environmental techniques, as described in the current paper, may also be utilized in different types of experiments in malacology, and represent a substantial technical advance in malacological work.

Rotaviruses as a cause of nosocomial, infantile diarrhoea in Northern Brazil: pilot study

Faecal samples were obtained from 190 children, aged 0 to 5 years, admitted to a public hospital in Belém, Pará, Brazil. These patients were placed in a pediatric ward with 40 beds distributed in six rooms. Case were classified into three groups: (a) nosocomial: children who developed gastroenteritis 72 hr or later after admission; (b) community-acquired: patients admitted either with diarrhoea or who had diarrhoea within 72 hr following admission; (c) non-diarrhoeic: those children who had no diarrhoea three days before and three days after collection of formed faecal sample. Specimens were routinely processed for the presence of rotaviruses, bacteria and parasites. Rotaviruses were detected through enzyme-linked immunosorbent assay (ELISA) and subsequently serotyped/electrophoretyped. Rotaviruses were the most prevalent enteropathogens among nosocomial cases, accounting for 39 % (9/23) of diarrhoeal episodes; on the other hand, rotaviruses ocurred in 8.3 % (11/133) and 9 % (3/34) of community-acquired and non-diarrhoeic categories, respectively. Mixed infections involving rotavirus and Giardia intestinalis and rotavirus plus G. intestinalis and Entamoeba histolytica were detected in frequencies of 8.6 and 4.3 %, respectively, in the nosocomial group. The absence of bacterial pathogens in this category, and the unusual low prevalence of these agents in the other two groups may reflect the early and routine administration of antibiotics following admission to this hospital. Rotavirus serotype 2 prevailed over the other types, accounting for 77.8 % of isolates from nosocomial diarrhoeal episodes. In addition, at least five different genomic profiles could be observed, of which one displayed an unusual five-segment first RNA cluster. Dehydration was recorded in all cases of hospital-acquired, rotavirus-associated diarrhoea, whereas in only 57 % of nosocomial cases of other aetiology. It was also noted that nosocomial, rotavirus-associated diarrhoeal episodes occur earlier (7 days), following admission, if compared with those hospital-acquired cases of other aetiology (14 days).

Persistent Infections by Leishmania (Viannia) braziliensis

Here we review the phenomenon of persistency in Leishmania (Viannia) braziliensis infections. In other Leishmania species where appropriate animal models exist, considerable advances in the understanding of basic immunologic mechanisms of persistency have been made; for a review see Aebisher (1994). On the contrary, the evidences of persistence in infections with L. braziliensis rest on studies of human clinical cases many of which we summarized and discussed in this work

Prevalência de Anofelinos (Diptera: Culicidae) no Crepúsculo Vespertino em Áreas da Usina Hidrelétrica de Itaipu, no Município de Guaíra, Estado do Paraná, Brasil

Systematic collections of anophelines were conducted from November 1994 to August 1995 from 18:00 to 20:00 hr using Shannon traps and human-bait along the lake margin which forms the Itaipu Hydroelectric reservoir, State of Paraná, Brazil. Species prevalence was studied at 15 min intervals. Anopheles albitarsis sensu latu and An. galvaoi, were the most frequently collected mosquitoes. All Anopheles species populations peaked between 18:45 and 19:30 hr. The observations illustrate the existence of a haematophagic activity cycle during the early evening hours: exogenous stimulus (the beginning of sunset) ® Shannon trap (light attraction) ® human bait (haematophagy) ® rest and digestion ® exogenous stimulus ® Shannon trap or surrounding vegetation. The greater abundance of An. albitarsis collected in human-bait and Shannon trap suggests it may be a potential malaria vector in the region