Using taxonomically unbiased criteria to prioritize resource allocation for oceanic island species conservation

Oceanic islands have been the grand stage of documented extinctions. In view of limited resources, efficient prioritization is crucial to avoid the extinction of taxa. This work lists the top 100 management priority species for the European archipelagos of the Macaronesian region (Azores, Madeira and the Canary Islands), taking into account both their protection priority and their management feasibility. Bryophytes, vascular plants, molluscs, arthropods and vertebrates were scored by species experts following two sets of criteria: (i) protection priority, including ecological value, singularity, public institutions’ management responsibilities and social value; (ii) management feasibility, including threats knowledge and control feasibility, external socio-economical support for management and biological recovery potential. Environmental managers weighted the same criteria according to their management importance. Final species scores were determined by the combination of both species valuation and criteria weighting. Vascular plants dominate the Top 100 list, followed by arthropods and vertebrates. The majority of listed taxa are endemic to one archipelago or even to a single island. The management feasibility criteria did not dictate that all taxa must be eminently endangered, as for most of the species it should be relatively easy to control threats. The main advantages of this process are the independent participation of scientists and conservation managers, the inclusion of criteria on both protection priority and management feasibility and the taxonomically unbiased nature of the process. This study provides a potentially useful biodiversity conservation tool for the Macaronesian archipelagos that could be readily implemented by the respective regional governments in future legislation.     

Extracellular inosine participates in tumor necrosis factor-alpha induced nitric oxide production in cultured Sertoli cells

Recent reports have described purinergic modulation of tumor necrosis factor-alpha (TNF-α) signaling in neutrophils and astrocytes. In Sertoli cells, both TNF-R1 and TNF-R2 TNF-α receptors are present and this cytokine modulates many functions of these cells related to the maintenance of spermatogenesis. Sertoli cells express distinct purinoreceptors and previous work has shown that these cells secrete extracellular nucleotides and their metabolites. In this work, we studied the possible role of extracellular purines in TNF-α signaling in cultured Sertoli cells. This cytokine increased inosine concentration from 30 min to 6 h, with no effect at 24 h. Both TNF-α and inosine increased nitrite accumulation and nitric oxide synthase activity. Erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA), an adenosine deaminase inhibitor, abolished the TNF-α induced inosine increase, nitrite accumulation and nitric oxide synthase activity. These results suggest that extracellular inosine acts as intermediary in TNF-α stimulated nitric oxide production in cultured Sertoli cells.     

Leishmania donovani peroxin 14 undergoes a marked conformational change following association with peroxin 5

The import of PTS1 proteins into the glycosome or peroxisome requires binding of a PTS1-laden PEX5 receptor to the membrane-associated protein PEX14 to facilitate translocation of PTS1 proteins into the lumen of these organelles. Quaternary structure analysis of protozoan parasite Leishmania donovani PEX14 (LdPEX14) revealed that this protein forms a homomeric complex with a size > 670 kDa. Moreover, deletion mapping indicated that disruption of LdPEX14 oligomerization correlated with the elimination of the hydrophobic region and coiled-coil motif present in LdPEX14. Analysis of the LdPEX5-LdPEX14 interaction by isothermal titration calorimetry revealed a molar binding stoichiometry of 1:4 (LdPEX5: LdPEX14) and an in-solution dissociation constant (K(d)) of approximately 74 nm. Calorimetry, circular dichroism, intrinsic fluorescence, and analytical ultracentrifugation experiments showed that binding of LdPEX5 resulted in a dramatic conformational change in the LdPEX14 oligomeric complex that involved the reorganization of the hydrophobic segment in LdPEX14. Finally, limited tryptic proteolysis assays established that in the presence of LdPEX5, LdPEX14 became more susceptible to proteolytic degradation consistent with this protein interaction triggering a significant conformational change in the recombinant and native LdPEX14 structures. These structural changes provide essential clues to how LdPEX14 functions in the translocation of folded proteins across the glycosomal membrane.     

Skeletal Muscle Abnormalities in Pulmonary Arterial Hypertension

Background

Pulmonary arterial hypertension is a progressive disease that is characterized by dyspnea and exercise intolerance. Impairment in skeletal muscle has recently been described in PAH, although the degree to which this impairment is solely determined by the hemodynamic profile remains uncertain. The aim of this study was to verify the association of structural and functional skeletal muscle characteristics with maximum exercise in PAH.

Methods

The exercise capacity, body composition, CT area of limb muscle, quality of life, quadriceps biopsy and hemodynamics of 16 PAH patients were compared with those of 10 controls.

Results

PAH patients had a significantly poorer quality of life, reduced percentage of lean body mass, reduced respiratory muscle strength, reduced resistance and strength of quadriceps and increased functional limitation at 6MWT and CPET. VO₂ max was correlated with muscular variables and cardiac output. Bivariate linear regression models showed that the association between muscular structural and functional variables remained significant even after correcting for cardiac output.

Conclusion

Our study showed the coexistence of ventilatory and quadriceps weakness in face of exercise intolerance in the same group of PAH patients. More interestingly, it is the first time that the independent association between muscular pattern and maximum exercise capacity is evidenced in PAH, independently of cardiac index highlighting the importance of considering rehabilitation in the treatment strategy for PAH.     

Thermographic evaluation of climatic conditions on lambs from different genetic groups

In production systems the characterization of genetic resources in relation to their capacity to respond to environmental conditions is necessary. The objective of this study was to evaluate the use of infrared thermography for separation of animals from different genetic groups and determine which phenotypic traits are important for climatic adaptation. A total of 126 suckling lambs from four different genetic groups (Santa Inês – SI, Bergamasca – B, Bergamasca X Santa Inês – BS, and Ile de France X Santa Inês – IL) were used. The animals were divided into two groups, one housed and another in an outside paddock. Thermograph photographs were taken at four-hour intervals over three full days. Temperatures of the nose, skull, neck, fore and rear flanks and rump were measured, as well as coat depth, the density and length of hairs, reflectance and color. The daily temperature range during the experimental period was more than 20°C, with animals experiencing heat (12 h to 15 h) and cold (24 h to 4 h) stress. The three main phenotypic traits that influenced genetic group separation were hair density, height of coat, and length of hairs. Thermograph temperatures were able to detect different responses of the genetic groups to the environment. Therefore, infrared thermography is a promising technique to evaluate the response of animals to the environment and to differentiate between genetic groups.     

Effect of caffeine on skeletal muscle function before and after fatigue

We studied the effect of caffeine on voluntary and electrically stimulated contractions of the adductor pollicis muscle in five adult volunteers. Caffeine (500 mg) was administered orally in a double-blind fashion. Electrical stimulation of the ulnar nerve was performed at 10, 20, 30, 50, and 100 Hz before and after a sustained voluntary contraction held at 50% of the maximal voluntary contraction (MVC). A brief tetanus at 30 Hz was also performed to calculate relaxation rate in the fresh muscle. Contractile properties, relaxation rate, and endurance were then assessed after caffeine and placebo, as well as the response of the fatigued muscle to different frequencies of stimulation. There was no difference in the maximal tension obtained with electrical stimulation (T100) or in the MVC between placebo and caffeine. The tensions developed with electrical stimulation at lower frequencies increased significantly with caffeine ingestion, shifting the frequency-force curve to the left, both before and after fatigue. Mean plasma caffeine concentration associated with these responses was 12.2 +/- 4.9 mg/l. We conclude that caffeine has a direct effect on skeletal muscle contractile properties both before and after fatigue as demonstrated by electrical stimulation.     

Occurrence of Euphoria lurida (Fabricius) (Coleoptera: Scarabaeidae) in the corn cultivated in Lowland at Rio Grande do Sul State

Euphoria lurida adults (Fabricius) is registered as pests of some fruits and flowers. However, this is the first record of this insect in maize fields. In march, 2006 adults attacked about 15% of maize plants in an area with almost 1 ha. The damage occurred in plants in the reproductive stage. Transversal and longitudinal holes were found in the stalks just above the ear insertion. The attack to the ear occurred more intensively in the upper part of the plant, where the insect fed on the silk and the filling grains.     

Red Blood Cells Preconditioned with Hemin Are Less Permissive to Plasmodium Invasion In Vivo and In Vitro

Malaria is a parasitic disease that causes severe hemolytic anemia in Plasmodium-infected hosts, which results in the release and accumulation of oxidized heme (hemin). Although hemin impairs the establishment of Plasmodium immunity in vitro and in vivo, mice preconditioned with hemin develop lower parasitemia when challenged with Plasmodium chabaudi adami blood stage parasites. In order to understand the mechanism accounting for this resistance as well as the impact of hemin on eryptosis and plasma levels of scavenging hemopexin, red blood cells were labeled with biotin prior to hemin treatment and P. c. adami infection. This strategy allowed discriminating hemin-treated from de novo generated red blood cells and to follow the infection within these two populations of cells. Fluorescence microscopy analysis of biotinylated-red blood cells revealed increased P. c. adami red blood cells selectivity and a decreased permissibility of hemin-conditioned red blood cells for parasite invasion. These effects were also apparent in in vitro P. falciparum cultures using hemin-preconditioned human red blood cells. Interestingly, hemin did not alter the turnover of red blood cells nor their replenishment during in vivo infection. Our results assign a function for hemin as a protective agent against high parasitemia, and suggest that the hemolytic nature of blood stage human malaria may be beneficial for the infected host.     

Ecotoxicological assessment of water and sediment of the Corumbataí River, SP, Brazil.

The Corumbataí River drains an economically important area which is mainly represented by the municipalities of Piracicaba and Rio Claro. In view of the impacts caused by the discharge of industrial waste and domestic sewage into the Piracicaba River, the Corumbataí has become increasingly significant as a source of water for the municipality of Piracicaba. However, chemical, physical, and microbiological analyses carried out prior to the present study had already indicated a decline in the quality of the Corumbataí waters. This study aimed to assess, through water and sediment samples, both acute and chronic toxicity to Daphnia magna and Daphnia similis, and to analyze acid-volatile sulfide (AVS) and simultaneously extracted metal (SEM) in the sediment. Resulting data were intended to be a contribution to future projects for the management and recuperation of this system. To that aim, water and sediment were collected at seven Corumbataí sampling stations in November 2003 and March 2004. Acute toxicity to D. similis was detected in water and sediment samples from the Piracicaba station, located at the mouth of the Corumbataí River. Chronic toxicity was identified in the water or sediment samples of all stations, with the exception of Analandia Montante (upstream), at the head of the river. This was found to affect survival, growth, and fecundity of the test-organisms. The AVS and SEM analyses showed the bioavailability of the metals, thus explaining toxicity found in bioassaying samples of water and sediment. The use of two test-organism species made it possible to obtain a better assessment of the condition of both water and sediment samples of the Corumbataí River.