Alterations induced by juvenile hormone in glandular cells of the Apis mellifera venom gland I - Application on the larvae (Hymenoptera: Apidae)

Histological analyses were made in order to evaluate the effects of the topic application of a synthetic juvenile hormone (JH-III Sigma) on the development of the venom glands in workers of Apis mellifera. Three experimental groups were used: the first received 1 μl of a dilution of the juvenile hormone in hexane (2μg/μl); the second group received 1 μl of hexane; and the third group, the control, did not receive any kind of treatment. The application was made on larvae at the beginning of the fifth instar and the glands were collected at different developmental stages. The results showed that the application of the diluted hormone, as well as the hexane alone, accelerated gland development in relation to the control group at all developmental stages studied. These data suggest that the juvenile hormone acts on the development of the venom gland; nevertheless, this action could be amplified by the effect of the solvent used in the present work, as well as in other studies concerning this matter.

Juvenile hormone promotes changes in the expression of hypopharyngeal gland proteins of worker Apis mellifera (Hymenoptera: Apidae)

The present investigation compares the protein electrophoreses profiles of the hypopharyngeal glands of 12 and 25 day old Apis mellifera workers, some of which were experimentally treated with an analogue of juvenile hormone in the moment of the emergence while others were not treated. According to the evaluation of the presented variations by four main bands, it is concluded that the analogue juvenile hormone changes the glandular genetic expression pattern, promoting the disappearance of two from the four main bands in 25 day old workers. The effect of this hormone is discussed as an hypopharyngeal maturation inductor, in synergetic action with the bee age acting early in the glandular cycle.

Somatic meiosis and development of the juvenile gametophyte in members of the Batrachospermales sensu lato (Rhodophyta)

Seven populations (six in culture and one sampled directly from nature) of the freshwater red algal families Batrachospermaceae, Lemaneaceae and Thoreaceae were examined, involving three species of Batrachospermum, two of Paralemanea and one of Thorea. All 'Chantransia' stages ultimately produced juvenile gametophytes. The production of juvenile gametophytes in the three populations of Batrachospermum was generally most abundant at 15°C and low irradiances (47-68 μmol photons m-2 s-1). The most abundant gametophyte development in the Paralemanea species was observed at 10°C and low or high irradiances (47-142 μmol photons m-2 s-1). Gametophyte production in Thoreaceae occurred at higher temperatures (20°C) and also at low irradiances. In species of the Batrachospermaceae and Lemaneaceae, the 'elimination cells' can be situated on the basal or suprabasal cell of the juvenile gametophyte, but the position is usually fixed in individual species. The presence and position of the elimination cells remain to be established in Thoreaceae. Our results corroborate a previous study suggesting that the position of elimination cells is such a constant feature that it is of potential diagnostic value at the generic or infrageneric (sectional or specific) level. The characteristics observed in the development of the juvenile gametophytes in species of Batrachospermaceae and Lemaneaceae essentially agreed with general descriptions in the previous studies. The characteristics of the Thoreaceae, with a distinctive developmental pattern of the juvenile gametophyte and the occurrence of two morphological types in the 'Chantransia' stage, support the proposal to elevate it to the ordinal level. Two remarkable observations in Batrachospermum species were the production of numerous juvenile gametophytes from filaments of the same plant of the 'Chantransia' stage and the formation of a system of rhizoidal filaments or cell agglomeration of the juvenile gametophytes, which produced new gametophytes. These two characteristics potentially increase the formation of additional gametophytes under favourable conditions.

Hodgkin disease in adult and juvenile groups from two different geographic regions in Brazil: Characterization of clinicopathologic aspects and relationship with Epstein-Barr virus infection

We analyzed clinicopathologic data, immunophenotype, and Epstein-Barr virus (EBV) status in 96 cases of Hodgkin disease (HD) in juveniles (younger than 20 years) and adults (20 years or older) from 2 distinctive states in Brazil. We studied 34 juvenile (group 1) and 16 adult (group 2) cases from Ceara and 31 juvenile (group 3) and 15 adult (group 4) cases from São Paulo. Ceara has a socioeconomic profile similar to a developing country; São Paulo is in better economic condition. Mixed cellularity (MC) was the major histologic subtype among groups 1 (22 [65%]), 3 (21 [68%]), and 4 (7 [47%]); nodular sclerosis (NS) was more frequent in group 2 (8 [50%]). EBV infection was observed in 61 cases (64%), including the following (among others): group 1, MC, 22 (65%) and NS, 4 (12%); group 2, NS, 3 (19%) and MC, 2 (12%); group 3, MC, 16 (52%) and NS, 1 (3%); and group 4, MC, 7 (47%). There was predominance of EBV+ HD cases in group 1 compared with group 3. HD in Brazilian patients is highly associated with EBV infection, but geographic differences reflect histologic subtypes and age distribution.

Effect of fish density during transportation on stress and mortality of juvenile Tambaqui Colossoma macropomum

The increased demand for juvenile tambaqui Colossoma macropomum for grow-out ponds and stocking programs in the Amazon state of Brazil has increased the transportation of this species. This study was designed to determine the optimum density of juvenile tambaqui during transportation in closed containers. Fish (51.9 ± 3.3 g and 14.9 ± 0.4 cm) were packed in sealed plastic bags and transported for 10 h at four densities: 78, 156, 234, and 312 kg/m3. After transportation, fish from each density were kept in separate 500-L tanks for 96 h. Mortality, 96-h cumulative mortality, water quality, and blood parameters (hematocrit, plasma cortisol, and glucose) were monitored. Fish mortality after transportation was significantly lower at densities of 78 and 156 kg/m3 than at 234 and 312 kg/m3. Cumulative mortality was significantly lower at a density of 78 kg/m3. Dissolved oxygen after 10 h of transportation remained high at a density of 78 kg/m3, but reached critically low values at all other densities. Ammonia concentration was highest at the lowest density and was lower at higher densities. Carbon dioxide concentration was lowest at the density of 78 kg/m3 but higher in the other treatments. Plasma glucose and cortisol increased significantly immediately after transportation at densities of 156, 234, and 312 kg/m3, returning to control values by 24 h. The best density for juvenile tambaqui during a 10-h transportation haul in a closed container was 78 kg/m3. At this density there was no fish mortality, water quality was kept within acceptable values, and fish were not stressed.

Influence of the application of juvenile hormone on the haemolymph total proteins and electrophoretic pattern of worker larvae of Apis mellifera

The aim of the present work was to verify the influence of the juvenile hormone (JH) applied on worker larvae of Apis mellifera 2 to 5 days old over the haemolymph total protein and electrophoretic pattern. Each larvae received topical applications of 1 ml of a solution of JH in hexane (1 μg/ml) on their 2 nd, 3 rd 4 th and 5 th day after hatching and had the amount and electrophoretic pattern of proteins from the haemolymph analyzed during the remaining days of their life. As a control, haemolymph of larvae of the same age that did not receive any kind of treatment was analyzed. The results show that the application of JH on larvae 3 or more days old affect the amount and electrophoretic pattern of the proteins, with this effect lasting through the subsequent days.

Electrophoretical Protein Profile in Apis mellifera (Hymenoptera; Apidae) Hypopharyngeal Glands under Juvenile Hormone Effect When the Colony is Grown in the Absence of Brood

Twelve-day-old and 25-day-old Apis mellifera workers were treated or not treated with juvenile hormone at the moment of emergence and reared in the colony without brood. Having the brood interference apart, the hormone effect on the hypopharyngeal glands protein expression was determined through the electrophoretical protein profiles of the both groups of bees. In those conditions, the hormone induced changes that were different from the control. Protein bands of 66 and 48 kDa were intensified in the 12-day-old bees, whereas band of 42 kDa was reduced in the 25-day-old bees. That indicated a different effect of the juvenile hormone in the function of bee aging, which promoted a glandular protein activation in the young bees and, in contrast, an inhibitory action in the 25-day-old bees workers.

Juvenile Hormone Effect on the Venom Gland Secretory Cycle in Workers of Apis mellifera (Hymenoptera, Apidae)

The present investigation analyzed the influence of Juvenile Hormone (JH) on the venom glands of Apis mellifera workers through protein dosage and electrophoresis of venom gland extracts of newly emerged workers which were treated with 1 μl JH dissolved in hexane, in concentration of 2μg/μl. Newly emerged workers non-treated and treated with 1 μl hexane were the controls. Both JH and hexane provoke quantitative changes on the gland protein titre and on the protein electrophoretic profile. The disappearance of protein bands in the venom gland extracts of 14 day-old treated workers, a situation normally found only in 35 day-old non-treated workers, suggests that the JH treatment induces a precocious maturation of the worker venom gland.

Comparison of the population structure of the fiddler crab Uca vocator (Herbst, 1804) from three subtropical mangrove forests

The population structure of U. vocator was investigated during a one-year period in three mangrove forests in southeast Brazil. The study specifically addressed comparisons on individual size juvenile recruitment and sex-ratio. The structure of the mangrove forests, i.e. density, basal area, and diameter, and the physical properties of sediments. i.e. texture and organic matter contents, were also examined. A catch-per-unit-effort (CPUE) technique was used to sample the crab populations using 15-min sampling periods by two people. Males always outnumbered females, probably due to ecological and behavioural attributes of these crabs. The median size of fiddler crabs differed among the sampled populations. The mangroves at Indaiá and Itamambuca showed higher productivity than those at Itapanhaú, where oil spills impacting the shore were reported. Marked differences were found regarding individual size, either their size at the onset of sexual maturity or their asymptotic size, suggesting that food availability may be favouring growth in the studied populations.

Reproductive biology of the shrimp Rimapenaeus constrictus (Decapoda, Penaeidae) in the ubatuba region of Brazil

Sexual maturity, temporal reproductive pattern, and recruitment of juveniles were examined for the shrimp Rimapenaeus constrictus at three different bays in the Ubatuba region (Mar Virado, Ubatuba, and Ubatumirim), State of São Paulo (23°S 45°W). Monthly samples were taken from January 1998 to December 1999. The presence or absence of mating plugs (associated with mating and insemination) and ovarian maturity were used to examine breeding in adult females. The whole sample comprised 3863 females and 1468 males. Estimates of size (carapace length) at the onset of sexual maturity were 7.0 mm and 7.8 mm for males and females, respectively. Higher percentage of females bearing ripe gonads was observed during spring and summer over the course of the study, contrasting to the low proportion in fall 1998 and winter 1999. Juvenile shrimps were sampled year-round. These results suggest a continuous reproductive pattern for R. constrictus. Mating, spawning, and juvenile recruitment took place mostly in shallow waters up to 20-m depths in the study region. Warm to mild temperatures may favour the spawning pattern observed in this species. The classical paradigm of continuous reproduction at lower latitudes, with increased seasonality of breeding period at higher latitudes, seems to apply to this species.

Economic evaluation of Piaractus mesopotamicus juvenile production in different rearing systems

In this study, the costs and gross income related to the production of pacu Piaractus mesopotamicus juveniles were evaluated. This evaluation took into consideration a semi-intensive rearing, with direct stocking of the larvae into fertilized ponds (IL 0), or an initial intensive larviculture system, in which the larvae were fed in the laboratory for 3 (IL 3), 6 (IL 6), or 9 days (IL 9) before being transferred to the ponds. After 45 days of rearing, a gradual increase in production costs was observed as intensive larviculture time increased. Gross income also increased due to better survival rates (11.0, 25.3, 45.4, and 54.0% for IL 0, IL 3, IL 6, and IL 9, respectively). Therefore, increased profits were obtained under intensive larviculture (US$ 0.27, US$ 6.07, US$ 11.99, and US$ 13.16 per one thousand larvae in treatments IL 0, IL 3, IL 6, and IL 9, respectively). In a larger scale production simulation, the results obtained with initial intensive larviculture also showed evident economic advantages, confirming the feasibility of this system in comparison with the direct stocking of larvae in ponds for the production of pacu juveniles. © 2004 Elsevier B.V. All rights reserved.

The relationship between onset of blood lactate accumulation, critical velocity, and maximal lactate steady state in soccer players

The objective of this study was to analyze the validity of the velocity corresponding to the onset of blood lactate accumulation (OBLA) and critical velocity (CV) to determine the maximal lactate steady state (MLSS) in soccer players. Twelve male soccer players (21.5 ± 1.0 years) performed an incremental treadmill test for the determination of OBLA. The velocity corresponding to OBLA (3.5 mM of blood lactate) was determined through linear interpolation. The subjects returned to the laboratory on 7 occasions for the determination of MLSS and CV. The MLSS was determined from 5 treadmill runs of up to 30-minute duration and defined as the highest velocity at which blood lactate did not increase by more than 1 mM between minutes 10 and 30 of the constant velocity runs. The CV was determined by 2 maximal running efforts of 1,500 and 3,000 m performed on a 400-m running track. The CV was calculated as the slope of the linear regression of distance run versus time. Analysis of variance revealed no significant differences between OBLA (13.6 ± 1.4 km·h-1) and MLSS (13.1 ± 1.2 km·h-1) and between OBLA and CV (14.4 ± 1.1 km·h-1). The CV was significantly higher than the MLSS. There was a significant correlation between MLSS and OBLA (r = 0.80), MLSS and CV (r = 0.90), and OBLA and CV (r = 0.80). We can conclude that the OBLA can be utilized in soccer players to estimate the MLSS. In this group of athletes, however, CV does not represent a sustainable steady-state exercise intensity. © 2005 National Strength & Conditioning Association.

Fermented soy product supplemented with isoflavones affected fat depots in juvenile rats

Objectives: This study investigated the effects of soy product fermented by Enterococcus faecium and Lactobacillus jugurti supplemented with isoflavones on adipose tissue, blood lipid, and glucose levels on juvenile rats. Methods: Rats were fed a cholesterol-enriched diet for 3 wk as a preliminary treatment to create hypercholesterolemia. They were then fed a chow diet (HC), a chow diet plus fermented soy product supplemented with isoflavones (HCFI), a chow diet plus placebo (HCP), or a chow diet plus placebo supplemented with isoflavones (HCPI), respectively, for an additional 3 wk. Results: The beneficial effects of fermented soy product supplemented with isoflavones on epididymal (EPI) and retroperitoneal (RET) fat pads was likely due to isoflavones because adipocyte circumference (micrometers) in the HC group was significantly larger (EPI: 105.66 ± 13.36; RET: 134.95 ± 25.40) than that in the HCFI group (EPI: 93.17 ± 12.80; RET: 108.62 ± 15.50) and HCPI group (EPI: 93.06 ± 15.10; RET: 112.34 ± 18.21). The probiotic micro-organism accentuated the antilipogenic effect of isoflavones on RET (HCFI: 108.62 ± 15.50 micrometers versus HCPI: 112.34 ± 18.21 micrometers). Moreover, the fermented product increased glucose concentration similar to that in the chow group but did not change blood lipids. Conclusion: This product may offer new approaches to obesity prevention. © 2005 Elsevier Inc. All rights reserved.

On the morphology of the juvenile stages of Ampulex compressa (Fabricius 1781) (Hymenoptera, Ampulicidae)

Ampulex compressa is a cockroach-hunting ampulicid wasp. In this survey we describe its egg, mature larva, along with the 1st and 2nd larval instars and cocoon, with emphasis on the characters considered important to the phylogeny of apoid wasps. It shares the following traits with the Sphecidae: reduced head setae, absence of antennal papilla, three antennal sensilla on antennal orbit, broad and strongly emarginate labrum, and spinneret with prominent raised lips. In common with other Ampulicidae, it has integument of the body granulose and without setae, mandibles with four or five teeth and lacking basal setae, maxillary palp larger than galea and discrete parietal bands. Distinct from the other Ampulicidae, it has a deep median longitudinal groove in the area above the salivary lips, a distinct group of five sensilla on the subgenal area, and lacks spines on the spiracular peritreme. Copyright © 2006 Magnolia Press.