Description of Macrochaetus kostei n.sp (Rotifera,Trichotriidae) from a coastal lagoon of Rio de Janeiro,Brazil

A new rotifer is described and figured based on females taken from Comprida lagoon, Rio de Janeiro State, in southeastern Brazil. This new animal belongs to the Genus Macrochaetus which includes several species recorded in South America. A key to species of the Genus Macrochaetus of the Neotropical Region is presented.     

Effect of tebuthiuron and temperature increase related to climate change on the photosynthesis of Nitella microcarpa var. wrightii (Charophyceae)

Journal of Applied Phycology - The Charales is an important order of freshwater algae, closely related to embryophytes and relevant primary producer in the aquatic food web, capable of increasing...     

Influence of breeding site availability on the oviposition behaviour of Aedes aegypti

Despite the importance of the mosquito Aedes aegypti in the transmission of arboviruses, such as yellow fever, Chikungunya fever and dengue fever, some aspects of their behaviour remain unknown. In the present study, the oviposition behaviour of Ae. aegypti females that were exposed to different densities of breeding sites (2, 4, 8 and 16) was evaluated in laboratory and semi-field conditions. The number of breeding sites that were used was proportional to the number available, but tended towards stabilisation. Females used four-six breeding sites on average, with a maximum of 11. A high percentage of eggs was observed in the water, along with the presence of a breeding site termed “favourite”, which received at least 40% of the eggs. The results are discussed in ecological, evolutionary and epidemiological approaches.     

LXR stimulates a metabolic switch and reveals cholesterol homeostasis as a statin target in Tasmanian devil facial tumor disease

1. Download : Download high-res image (163KB)
2. Download : Download full-size image

     

Strength training during pregnancy influences hippocampal plasticity but not body development in neonatal rats

Objective:To describe the effects of strength exercise practice during pregnancy on the offspring’s development parameters: growth and motor performance, hippocampal neuroplasticity, and stress levels.Methods:Pregnant Wistar rats were divided into two groups: sedentary and exercised rats. Exercised pregnant rats were subjected to a strength training protocol (vertical ladder climbing) throughout the gestational period. Male offspring’s body weight, length, and head size were evaluated during the neonatal period (postnatal days [P]2–P21), as well as motor milestones during P0–P8. At P8, a set of male pups were subjected to global hippocampal DNA methylation, hippocampal cell proliferation, and plasma corticosterone concentration.Results:Offspring from trained mothers presented a transient change in body morphometric evaluations, no differences in milestone assessments, enhancement of cell proliferation in the dentate gyrus of the hippocampus, and decreased global hippocampal DNA methylation compared with the offspring from sedentary mothers. Furthermore, strength training during pregnancy did not change the corticosterone concentration of exercised mothers and their offspring.Conclusions:These data indicate that strength training can protect offspring’s development and could impact positively on parameters linked to cognitive function. This study provides a greater understanding of the effects of strength exercise practiced during pregnancy on the offspring’s health.     

The tax revenue potential of manganese nodules

Abstract

Mounting interest in deep seabed mining has raised high expectations in the tax revenue potential of the future nodule industry. In the absence of any existing commercial nodule mining operation, estimates of the likely “take”; are highly conjectural. This paper develops four alternative estimates for 1985 based on sets of variables on nodule mining, mineral markets and “tax rates”; that range from conservative to overly optimistic. The resulting “take”; from these calculations range from $22 million to $I .2 billion, with the most likely actual figure between 50 and 150 million dollars by 1985.     

Berberine reverts hepatic mitochondrial dysfunction in high-fat fed rats: A possible role for SirT3 activation

Berberine is an isoquinoline alkaloid with anti-diabetic properties. Despite the central role of liver and thus hepatic mitochondria in whole-body metabolism, berberine effects on hepatic mitochondrial function in an obesity model are still unknown. Here, we demonstrate that berberine treatment recovers mitochondrial efficiency when altered by a high-fat feeding. Mitochondria isolated from the liver of high-fat fed rats exhibited decreased capacity to accumulate calcium and impaired oxidative phosphorylation (OXPHOS) capacity, as shown by impaired mitochondrial membrane potential, oxygen consumption and cellular ATP levels. Interestingly, the recovery of mitochondrial function by berberine was associated with an increased activity of the mitochondrial sirtuin 3 (SirT3). In conclusion, berberine potent protective effects against metabolic syndrome may rely on increasing mitochondrial SirT3 activity, normalizing mitochondrial function and preventing a state of energetic deficit caused by impaired OXPHOS.     

Unraveling the mechanism of the farnesyltransferase enzyme

Farnesyltransferase enzyme (FTase) is currently one of the most fascinating targets in cancer research. Studies in other areas, namely in the fight against parasites and viruses, have also led to very promising results. However, in spite of the thrilling achievements in the development of farnesyltransferase inhibitors (FTIs) over the past few years, the farnesylation mechanism remains, to some degree, a mystery. This review tries to shed some light on this puzzling enzyme by analyzing seven key mechanistic dilemmas, based on recent studies that have dramatically changed the way this enzyme is currently perceived.