Population growth rate of the depredating Podisus nigrispinus (Heteroptera: Pentatomidae) and of the Tuta absoluta (Leptoptera: gelechiidae) in wintering place

The fertility life table of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) preying either on Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) caterpillars or on alternative prey Tenebrio molitor L. (Coleoptera: Tenebrionidae) under greenhouse conditions (30 +/- 5 degrees C, 61 +/- 23% RH) were studied. The life table was also determined for the pest T. absoluta under the same conditions. The net reproductive rate (Ro) and the intrinsic rate of natural increase (rm) were higher 14.13 and 46.32 times for predators fed on T. molitor prey, however, the generation time (T) was similar between prey. The pest T. absoluta showed Ro and rm higher 2.15 and 32.10 times than those achieved for predators fed on this pest. However, females fed on a suitable prey T. molitor showed higher Ro and rm than those yielded for the pest. The survival curves were similar for P. nigrispinus females fed on both prey and classified as being type II by Weibull analysis. The results suggest that P. nigrispinus is able to maintain its population preying only on T. absoluta caterpillars; however, the life table parameters determined individually for both showed that the pest produces more generations per year and faster population natural growth than the predator.     

Effect of oil and dispersant on growth and chlorophyll a content of the marine microalga Tetraselmis suecica.

Low hydrocarbon concentrations stimulated the growth of Tetraselmis suecica, whereas higher concentrations (200 ppm) inhibited growth. The content of chlorophyll a in this microalga was affected in a similar way. Crude oil had the most marked effects. Dispersant SEAKLIN-101-NT and mixtures of oil and SEAKLIN-101-NT did not show selective toxicity for the microalga, although inhibitory effects could be observed at high concentrations.     

Effect of oil concentration and residence time on the biodegradation of α-pinene vapours in two-liquid phase suspended-growth bioreactors

Recently, research on the use of binary aqueous-organic liquid phase systems for the treatment of polluted air has significantly increased. This paper reports the removal of α-pinene from a waste air stream in a continuous stirred tank bioreactor (CSTB), using either a single-liquid aqueous phase or a mixed aqueous-organic liquid phase. The influence of gas flow rate, load and pollutant concentration was evaluated as well as the effect of the organic to aqueous phase ratio. Continuous experiments were carried out at different inlet α-pinene concentrations, ranging between 0.03 and 25.1 g m?3 and at four different flow rates, corresponding to residence times (RTs) of 120 s, 60 s, 36 s and 26 s. The maximum elimination capacities (ECs) reached in the CSTB were 382 g m?3 h?1 (without silicone oil) and 608 g m?3 h?1 (with 5%v/v silicone oil), corresponding to a 1.6-fold improvement using an aqueous-organic liquid phase. During shock-loads experiments, the performance and stability of the CSTB were enhanced with 5% silicone oil, quickly recovering almost 100% removal efficiency (RE), when pre-shock conditions were restored. The addition of silicone oil acted as a buffer for high α-pinene loads, showing a more stable behaviour in the case of two-liquid-phase systems.     

Identification of a direct hemolytic effect dependent on the catalytic activity induced by phospholipase‐D (dermonecrotic toxin) from brown spider venom

Brown spiders have world‐wide distribution and are the cause of health problems known as loxoscelism. Necrotic cutaneous lesions surrounding the bites and less intense systemic signs like renal failure, DIC, and hemolysis were observed. We studied molecular mechanism by which recombinant toxin, biochemically characterized as phospholipase‐D , causes direct hemolysis (complement independent). Human erythrocytes treated with toxin showed direct hemolysis in a dose‐dependent and time‐dependent manner, as well as morphological changes in cell size and shape. Erythrocytes from human, rabbit, and sheep were more susceptible than those from horse. Hemolysis was not dependent on ABO group or Rhesus system. Confocal and FACS analyses using antibodies or GFP‐phospholipase‐D protein showed direct toxin binding to erythrocytes membrane. Moreover, toxin‐treated erythrocytes reacted with annexin‐V and showed alterations in their lipid raft profile. Divalent ion chelators significantly inhibited hemolysis evoked by phospholipase‐D , which has magnesium at the catalytic domain. Chelators were more effective than PMSF (serine‐protease inhibitor) that had no effect on hemolysis. By site‐directed mutation at catalytic domain (histidine 12 by alanine), hemolysis and morphologic changes of erythrocytes (but not the toxin's ability of membrane binding) were inhibited, supporting that catalytic activity is involved in hemolysis and cellular alterations but not toxin cell binding. The results provide evidence that L. intermedia venom phospholipase‐D triggers direct human blood cell hemolysis in a catalytic‐dependent manner. J. Cell. Biochem. 107: 655–666, 2009. © 2009 Wiley‐Liss, Inc.     

Experimental Addition of Green Plants to the Nest Increases Testosterone Levels in Female Spotless Starlings

Multiple male traits and displays may act in signalling sexually selected processes during courtship. Spotless starling males (Sturnus unicolor) carry green plants into their nests before egg laying, and recent studies have shown that this behaviour is related to female breeding decisions and the production of male‐biased broods. Although the functional implications of this effect on females are not yet clear, data suggest that it could be mediated by female circulating hormones. Additionally, females may show higher androgen levels as a consequence of the increased female–female competition generated by the increase in male attractiveness. We tested this hypothesis using the same manipulation of green nesting material that has been previously shown to result in an increase of male attractiveness in male spotless starlings. We found that females in experimental nests increased their circulating testosterone levels during the laying period. In addition, there was an increase of social interferences in the experimental nests because of the addition of green plants. We hypothesise that testosterone may allow females to maintain their mating status when competing with other females for the preferred males. Addition of green plants also increased the variance in the levels of circulating testosterone, suggesting plasticity between females in their response to the manipulation. We propose that there is a functional link between high testosterone levels, male‐biased sex ratios and female resource‐holding potential in intra‐sexual competition in this species.     

Role of hypoxia‐inducible factor 1α as a potential biomarker for renal diseases—A systematic review

Renal cells need oxygen for homeostasis; it is known for adjusting cellular functioning and the energy obtainment have a broad relationship with cellular respiration, through the O₂ bioavailability. O₂ homeostasis regulation in the kidney is mediated by hypoxia‐inducible factors (HIFs). HIF is divided into three α isoforms, represented by HIF‐1α, HIF‐2α, and HIF‐3α in addition to three paralogs of HIF‐1β; these are involved in some metabolic processes, as well as in the pathogenesis of several diseases. Renal biopsy analyses of patients and experimental animal models aim to understand the relationship between HIF and protection against developing renal diseases or the induction of their onset, being thus this molecule can be considered a potential biomarker of renal disease. We carried out a systematic review to which we included studies on HIF‐1α and renal disease in the last 5 years (2013‐2018) in researches with humans and/or animal model through searches in three databases: LILACS, PubMed, and SciELO by two researchers. We obtained 22 articles that discussed the relationship with HIF as inductor or protector against renal disease and no relation between HIF and renal. We observed controversies remain regarding the relation between of HIF with renal diseases; this may be related to the different intracellular pathways mediated by HIF‐1α, thereby determining differentiated cellular responses.     

Instantaneously measured traits may detect non-plastic ecophysiological performances in response to drought, explaining distributions of Styrax species in the Cerrado

We analyzed the differences between irrigated and non-irrigated plants of three congeneric Styrax species that present distinct distribution patterns in the physiognomies of the Cerrado vegetation in Brazil. Styrax ferrugineus showed a stomatal conductance (g _s) unresponsive to soil water deficit in potted plants. This may explain the high gas exchange and photochemical efficiency found in this species, which is well adapted to the Cerrado sensu stricto (s. str.), a savanna-type vegetation. S. camporum, which is widely distributed in the Cerrado sensu lato (s. l.) areas, was the only species that exhibited increased intrinsic water use efficiency on the days of maximum water deficit. This result distinguishes S. camporum from S. pohlii, which is a forest species, since the g _s of both species decreased during the days of maximum water stress. In contrast to other studies, we propose that instantaneously measured traits, such as leaf gas exchange rates and chlorophyll fluorescence, may be used to detect non-plastic performances in response to environmental stress, helping explain distinct geographical distributions of congeneric species in the Cerrado vegetation.     

Development and reproduction of a predatory stinkbug, Podisus nigrispinus in relation to two different prey types and environmental conditions

Abiotic factors, prey availability, prey type, and plant host actsimultaneously under field conditions. Their combined effects werepartially investigated for the predatory stinkbugPodisus nigrispinus(Dallas) (Heteroptera: Pentatomidae) preying on tomato leafminer (TLM)caterpillars Tuta absoluta (Meyrick)(Lepidoptera: Gelechiidae) (a preyfeeding on a plant host), and compared to yellow mealworm (YMW)Tenebrio molitor (Coleoptera: Tenebrionidae)pupae (a prey not feeding ona plant host). These experiments were carried out in the laboratory and inan open-sided greenhouse. In general, the environmental variationsbetween laboratory and open-sided greenhouse did not induce differencesin life history characteristics forP. nigrispinus feeding on the sameprey type. However, development and reproductionof P. nigrispinuswas greatly affected by prey type. Nymphal developmental times weresimilar between prey types under laboratory conditions; but were longer(and produced adults of lower body weight) when predators in theopen-sided greenhouse were fed on TLM compared with YMW. Mean mortalityduring the second instar was higher on both prey types in the open-sidedgreenhouse than in the laboratory. Adult emergencewas 38.5 and 50% inthe laboratory, and 32.5 and 48.6%in the open-sided greenhouse for bugsfed on TLM and YMW, respectively. Reproductive characteristics weresimilar for the different environmental conditions when the predator fed onthe same prey, but offspring production was greater for females fed on YMWcompared to females fed on TLM. These results suggest thatP. nigrispinus can adjust its performance accordingto the type of prey available, independently from environmentalvariations. It has the ability to survive on alternative prey,enabling it to maintain a presence in thetomato ecosystem until a primary pest species arrives.     

Feathers at nests are potential female signals in the spotless starling

Although the presence of feathers in the nest is widespread among birds, it has not been previously suggested that feathers can be used as sexual signals. Females of the spotless starling (Sturnus unicolor) regularly carry feathers to their nest, mostly during laying and incubation. We show that the arrangement of these feathers was non-random with respect to the side (obverse or reverse) placed upwards (which can be viewed from the nest entrance). Feathers of the wood pigeon (Columba palumbus) and the spotless starling, which exhibit higher ultraviolet and visible reflectance on their reverse side, were predominantly placed with this side upwards. On the contrary, feathers of the jay (Garrulus glandarius) were predominantly found exhibiting the obverse side, which possesses higher reflectance in this species. Feathers of the azure-winged magpie (Cyanopica cyana), with similar reflectance values on either side, were placed indiscriminately in obverse and reverse positions. The results suggest that feathers are arranged to maximize their conspicuousness within the nest and hence that they might be potentially used as intraspecific signals.