Thermal preferences and limits of Triatoma brasiliensis in its natural environment - Field observations while host searching

The goal of this work was to explore the thermal relationship betweenforaging Triatoma brasiliensis and its natural habitat during thehottest season in the state of Ceará, Brazil. The thermal profiles were determinedusing infrared analysis. Although the daily temperature of rock surfaces varied in awide range, T. brasiliensis selected to walk through areas withtemperatures between 31.7-40.5ºC. The temperature of T. brasiliensisbody surface ranged from 32.8-34.4ºC, being higher in legs than the abdomen.A strong relationship was found between the temperature of the insect and thetemperature of rock crevices where they were hidden (r: 0.96, p < 0.05). Thespecies was active at full sunlight being a clear example of how the light-darkrhythm may be altered, even under predation risk. Our results strongly suggest athermal borderline for T. brasiliensis foraging activity near 40ºC.The simultaneous determination of insect body and rock temperatures here presentedare the only obtained in natural habitats for this or other triatomines.     

Amlodipine preserves the glomerular number in spontaneously hypertensive rats

The calcium channel blockers have individual pharmacological and therapeutic properties that may vary, but as a group, they are effective antihypertensive agents in patients with renal disease. Their effects on the kidney may extend beyond BP reduction alone. Fifteen one-year-old male spontaneously hypertensive rats (SHR) were separated in three groups: Initial control group (IC), Final control group (FC, SHR received standard rat chow and fresh water ad libitum during 15 weeks), Amlodipine group (Aml, SHR) received 0.2 mg/kg/day of amlodipine in addition to food and water during 15 weeks. The glomerular number was estimated using the disector method. In the Control group, the BP level increased almost 20 per cent in the first six weeks (from 186 +/- 11 to 223 +/- 16 mmHg, p<0.01) and then BP level increased almost 15 percent until week 15 (from 223 +/- 16 to 258 +/- 20 mmHg, p<0.01). In the same period, the Aml group showed a progressively low BP, reaching a level almost 50 per cent lower in the week 15 than in the week 1 (from 190 +/- 15 to 101+/-8 mmHg, p<0.01). Amlodipine treatment significantly decreased the serum creatinine, more than 12 per cent lower than the FC group (from 70.4 +/- 6.2 to 61.4 +/- 5.2 micromol/L, p<0.05). However, proteinuria was not different when groups were compared. The FC group reached a glomerular number almost 20 percent smaller than the IC and Aml groups (from 35 x 10(3) +/- 7 x 10(3) in IC group, 34 x 10(3) +/- 4 x 10(3) in Aml group to 27 x 10(3) +/- 3 x 10(3) in FC group, p<0.05). A possible protective effect of amlodipine against the loss of glomeruli in SHR is a major additional action of amlodipine in the treatment of hypertension mainly when the renal lesion already exists.     

Effect of centrifugation and sugar supplementation on the semen cryopreservation of captive collared peccaries (Tayassu tajacu)

The present study is aimed at evaluating the effect of centrifugation for seminal plasma removal and the supplementation of fructose or glucose to the Tris-based extender on the kinematic patterns of the motility parameters of frozen–thawed semen obtained from captive collared peccaries (Tayassu tajacu). Semen samples (n = 14) were collected from 10 sexually mature male collared peccaries by electroejaculation. These samples were further evaluated for parameters such as motility, vigor, sperm viability, membrane integrity, and sperm morphology. The samples were divided into four aliquots, and only two of these aliquots were centrifuged. The semen aliquots (centrifuged and raw semen samples) were diluted in Tris-based extenders supplemented with fructose or glucose. Egg yolk (20%) and glycerol (3%) were added to all the samples which were cryopreserved in liquid nitrogen and thawed at 37 °C/1 min. The frozen–thawed semen was evaluated for the same parameters described for the fresh semen. On the other hand, the kinematic motility patterns were evaluated by a computer-aided system. After thawing, it was observed that the values for the total sperm motility were around 30% for all the samples. A negative effect of centrifugation was verified for parameters such as sperm morphology, linearity, straightness, and beat cross frequency (P < 0.05). However, no differences between fructose and glucose were verified for any semen end point (P > 0.05). In conclusion, it is not recommended to centrifuge the ejaculates from collared peccaries prior to conducting the cryopreservative procedures using a Tris-based extender supplemented with fructose or glucose.     

First record of Sinoxylon conigerum Gerstäcker (Coleoptera: Bostrichidae) in Brazil

This is the first register of Sinoxylon conigerum attacking timber of teak (Tectona grandis L.f.), mango tree (Mangifera indica L.) and (Astronium fraxinifolium Schott) in the municipalities of Cuiabá and Várzea Grande, State of Mato Grosso, Brazil.     

Histological description of the ink gland of the tropical sea hare Aplysia dactylomela Rang, 1828

This work describes for the first time the ink gland of Aplysia dactylomela Rang, 1828 using light microscopy and histochemical tests. The results reveal that this organ is covered by a layer of simple epithelium and that there are some differences between the epithelium facing the mantle shelf and that facing the mantle cavity. The former consists of columnar cells, which may have a secretory function, whereas the latter is a cuboidal epithelium. Underneath the epithelium and along the whole gland there are fibres of smooth muscle and collagen, organized in groups of parallel bundles. There are vesicles of different diameters, apparently with similar morphology. Some are filled with ink, whereas others are either granular or clear. The ink is released through a duct formed by invaginations of the cuboidal epithelium. Tests with bromophenol blue and periodic acid Schiff indicated that the ink and granulated vesicles contain proteins and carbohydrates or maybe glycoproteins. Between the fibre bundles and the vesicles there are dispersed cells. A diagram is presented emphasizing the covering epithelium, the distribution of muscle and collagen fibres, the dispersed cells, vesicles and ducts. This organization is similar to that of the other Aplysia species studied to date, A. californica.     

Photosynthetic efficiency and rate of CO2 assimilation by Arthrospira (Spirulina) platensis continuously cultivated in a tubular photobioreactor

Similar to other photosynthetic microorganisms, the cyanobacterium Arthrospira platensis can be used to produce pigments, single cell proteins, fatty acids (which can be used for bioenergy), food and feed supplements, and biofixation of CO₂. Cultivation in a specifically designed tubular photobioreactor is suitable for photosynthetic biomass production, because the cultivation area can be reduced by distributing the microbial cells vertically, thus avoiding loss of ammonia and CO₂. The aim of this study was to investigate the influence of light intensity and dilution rate on the photosynthetic efficiency and CO₂ assimilation efficiency of A. platensis cultured in a tubular photobioreactor in a continuous process. Urea was used as a nitrogen source and CO₂ as carbon source and for pH control. Steady‐state conditions were achieved in most of the runs, indicating that continuous cultivation of this cyanobacterium in a tubular photobioreactor could be an interesting alternative for the large‐scale fixation of CO₂ to mitigate the greenhouse effect while producing high protein content biomass.     

Effects of light intensity and dilution rate on the semicontinuous cultivation of Arthrospira (Spirulina) platensis. A kinetic Monod-type approach

Semicontinuous cultures were carried out at different dilution rates (D) and light intensities (I) to determine the maximum productivity of Arthrospira platensis cultivated in helicoidal photobioreactor up to the achievement of pseudo-steady-state conditions. At I=108 μmol photons m(-2) s(-1), the semicontinuous regime ensured the highest values of maximum cell concentration (X(m)=5772±113 mg L(-1)) and productivity (P(XS)=1319±25 mg L(-1) d(-1)) at the lowest (D=0.1 day(-1)) and the highest (D=0.3 day(-1)) dilution rates, respectively. A kinetic model derived from that of Monod was proposed to determine the relationship between the product of light intensity to dilution rate (ID) and the cell productivity, which were shown to exert a combined influence on this parameter. This result put into evidence that pseudo-steady-state conditions could be modified according to circumstances, conveniently varying one or other of the two independent variables.