The Shc protein Rai enhances T-cell survival under hypoxia

Hypoxia occurs in physiological and pathological conditions. T cells experience hypoxia in pathological and physiological conditions as well as in lymphoid organs. Indeed, hypoxia-inducible factor 1α (HIF-1α) affects T cell survival and functions. Rai, an Shc family protein member, exerts pro-survival effects in hypoxic neuroblastoma cells. Since Rai is also expressed in T cells, we here investigated its role in hypoxic T cells. In this work, hypoxia differently affected cell survival, proapoptotic, and metabolic programs in T cells, depending upon Rai expression. By using Jurkat cells stably expressing Rai and splenocytes from Rai^−/−mice, we demonstrated that Rai promotes T cell survival and affects cell metabolism under hypoxia. Upon exposure to hypoxia, Jurkat T cells expressing Rai show (a) higher HIF-1α protein levels; (b) a decreased cell death and increased Akt/extracellular-signal-regulated kinase phosphorylation; (c) a decreased expression of proapoptotic markers, including caspase activities and poly(ADP-ribose) polymerase cleavage; (d) an increased glucose and lactate metabolism; (e) an increased activation of nuclear factor-kB pathway. The opposite effects were observed in hypoxic splenocytes from Rai^−/−mice. Thus, Rai plays an important role in hypoxic signaling and may be relevant in the protection of T cells against hypoxia.     

IDENTIFICATION OF A CALCIUM-BINDING, BRAIN SPECIFIC PROTEIN IN THE AXOPLASM OF SQUID GIANT AXONS

Abstract— An acidic protein has been isolated from the optic lobes of two cephalopods, Sepia officinalis and Loligo vulgaris. The protein has been obtained in pure form by fractionation with ammonium sulphate and chromatography on DEAE-cellulose and Sephadex G 100. Its apparent molecular weight is 13,000–15,000. Glutamic and aspartic acids account for 35 per cent of the amino acid residues. The protein binds Ca²⁺ ions with an apparent dissociation constant of 2·5 × 10⁻⁵ M at physiological concentrations of KCI. Antibodies have been prepared against the protein purified from Sepia officinalis. By the micro-complement fixation technique it has been shown that the protein is highly concentrated in the nervous system of cephalopods and that the amount in the axoplasm of squid giant axons is eight to nine-fold higher than in the optic lobes of the same animal.     

Recovering mountain Mediterranean grasslands for breeding birds: ecology and population status shape species responses to management

The Mediterranean basin is considered one of the most important biodiversity hotspots. This extraordinary richness originates mainly from thousands of years of human activities that deeply modified the landscape. Safeguarding the so-called cultural landscapes plays a key role in biodiversity conservation. In this paper we present the results of our monitoring of the effects of the life project “Preservation of mountain grasslands of the Tuscan Apennines”, mainly characterized by shrub-cutting actions, on bird populations in the Pratomagno pasture, one of the two areas where the project was implemented, a SPA in eastern Tuscany. The monitoring plan covers a period of 5 years. We tested the effects of shrub clearing on a series of bird community parameters, such as abundance and richness of common species and of some ecological guilds. We also tested the timing of the response to the interventions (immediate or drawn out over time). Our results show a dramatic decrease of birds associated with shrubland, while there were no important increases in grassland species, with the sole exception of Woodlark. Regardless of their positive or negative effects, our results show different response times for individual species or groups of species. Moreover, species with a bad regional conservation status increased less than those with a good one. Broadly speaking, these results suggest that the efficacy of such projects depends on a careful preliminary assessment of a number of aspects, encompassing the nature of the interventions themselves and the characteristics of the target sites, but also the type of response of target species and the conservation status of target populations.     

Review: predatory soil mites as biocontrol agents of above- and below-ground plant pests

Biological pest control is becoming increasingly important for sustainable agriculture. Although many species of natural enemies are already being used commercially, efficient biological control of various pests is still lacking, and there is a need for more biocontrol agents. In this review, we focus on predatory soil mites, their role as natural enemies, and their biocontrol potential, mainly in vegetable and ornamental crops, with an emphasis on greenhouse systems. These predators are still underrepresented in biological control, but have several advantages compared to predators living on above-ground plant parts. For example, predatory soil mites are often easy and affordable to mass rear, as most of them are generalist predators, which also means that they may be used against various pests and can survive periods of pest scarcity by feeding on alternative prey or food. Many of them can also endure unfavourable conditions, making it easier for them to establish in various crops. Based on the current literature, we show that they have potential to control a variety of pests, both in greenhouses and in the field. However, more research is needed to fully understand and appreciate their potential as biocontrol agents. We review and discuss several methods to increase their efficiency, such as supplying them with alternative food and changing soil/litter structure to enable persistence of their populations. We conclude that predatory soil mites deserve more attention in future studies to increase their application in agricultural crops.

     

Annual Acoustic Presence of Fin Whale (Balaenoptera physalus) Offshore Eastern Sicily,Central Mediterranean Sea

In recent years, an increasing number of surveys have definitively confirmed the seasonal presence of fin whales (Balaenoptera physalus) in highly productive regions of the Mediterranean Sea. Despite this, very little is yet known about the routes that the species seasonally follows within the Mediterranean basin and, particularly, in the Ionian area. The present study assesses for the first time fin whale acoustic presence offshore Eastern Sicily (Ionian Sea), throughout the processing of about 10 months of continuous acoustic monitoring. The recording of fin whale vocalizations was made possible by the cabled deep-sea multidisciplinary observatory, “NEMO-SN1”, deployed 25 km off the Catania harbor at a depth of about 2,100 meters. NEMO-SN1 is an operational node of the European Multidisciplinary Seafloor and water-column Observatory (EMSO) Research Infrastructure. The observatory was equipped with a low-frequency hydrophone (bandwidth: 0.05 Hz–1 kHz, sampling rate: 2 kHz) which continuously acquired data from July 2012 to May 2013. About 7,200 hours of acoustic data were analyzed by means of spectrogram display. Calls with the typical structure and patterns associated to the Mediterranean fin whale population were identified and monitored in the area for the first time. Furthermore, a background noise analysis within the fin whale communication frequency band (17.9–22.5 Hz) was conducted to investigate possible detection-masking effects. The study confirms the hypothesis that fin whales are present in the Ionian Sea throughout all seasons, with peaks in call detection rate during spring and summer months. The analysis also demonstrates that calls were more frequently detected in low background noise conditions. Further analysis will be performed to understand whether observed levels of noise limit the acoustic detection of the fin whales vocalizations, or whether the animals vocalize less in the presence of high background noise.     

Charting the history of agricultural experiments

Agricultural experimentation is a world in constant evolution, spanning multiple scientific domains and affecting society at large. Even though the questions underpinning agricultural experiments remain largely the same, the instruments and practices for answering them have changed constantly during the twentieth century with the advent of new disciplines like molecular biology, genomics, statistics, and computing. Charting this evolving reality requires a mapping of the affinities and antinomies at work within the realm of agricultural research, and a consideration of the practices, tools and social and political structures in which agricultural experiments are grounded. Three main questions will be addressed to provide an overview of the complex world of agricultural research investigated by the special issue: What is an agricultural experiment? Who is an experimenter in agriculture? Where do agricultural experiments take place? It will become apparent that agricultural experiments have a wide relevance for human development as they touch upon concerns related to human health and nutrition, contribute to policy discussions, and can affect the social and political structures in which farming is embedded.