Genetic diversity and structure of blue whales (Balaenoptera musculus) in Australian feeding aggregations

The worldwide distribution of blue whales (Balaenoptera musculus) has not prevented this species from becoming endangered due to twentieth century whaling. In Australia there are two known feeding aggregations of blue whales, which most likely are the pygmy subspecies (B. m. brevicauda). It is unknown whether individuals from these feeding aggregations belong to one breeding stock, or multiple breeding stocks that either share or occupy separate feeding grounds. This was investigated using ten microsatellite loci and mitochondrial DNA control region sequences (N = 110). Both sets of markers revealed no significant genetic structure, suggesting that these whales are likely to belong to the same breeding stock.     

So different, yet so similar: meta-analysis and policy modeling of willingness to participate in clinical trials among Brazilians and Indians

Background

With the global expansion of clinical trials and the expectations of the rise of the emerging economies known as BRICs (Brazil, Russia, India and China), the understanding of factors that affect the willingness to participate in clinical trials of patients from those countries assumes a central role in the future of health research.

Methods

We conducted a systematic review and meta-analysis (SRMA) of willingness to participate in clinical trials among Brazilian patients and then we compared it with Indian patients (with results of another SRMA previously conducted by our group) through a system dynamics model.

Results

Five studies were included in the SRMA of Brazilian patients. Our main findings are 1) the major motivation for Brazilian patients to participate in clinical trials is altruism, 2) monetary reimbursement is the least important factor motivating Brazilian patients, 3) the major barrier for Brazilian patients to not participate in clinical trials is the fear of side effects, and 4) Brazilian patients are more likely willing to participate in clinical trials than Indians.

Conclusion

Our study provides important insights for investigators and sponsors for planning trials in Brazil (and India) in the future. Ignoring these results may lead to unnecessary fund/time spending. More studies are needed to validate our results and for better understanding of this poorly studied theme.     

Nest site selection of the Kelp gull (Larus dominicanus) in the Beagle Channel, Tierra del Fuego, Argentina

Nest site selection of Kelp gulls Larus dominicanus breeding in Conejo and Bridges islands, Tierra del Fuego, Argentina, was assessed between 14 and 30 December 2005 to describe variability in nest site features and determine variables affecting nest choice. Fourteen microhabitat variables were quantified at 40 nest sites and at 40 random points in each island during the late incubation stage. Nests at the two colonies were placed on different kinds of substrates across areas with varying degrees of cover provided either by rocks or vegetation. Despite the variability observed in nest site features, rock cover and rocky substrates were the main factors determining nest site selection. At Conejo Island, nest sites presented more rock cover, less percentage of vegetation cover and of vegetation debris substrate, and were placed further from the nearest vegetation in comparison to random points. Similarly, gulls at Bridges Island selected nest sites with more rock cover which were placed mainly on rocky and vegetation substrates. This contrasts with results previously obtained in Argentina, which indicated that vegetation is a key factor influencing Kelp gull nest site selection. Over 80% of the nests at both study colonies were placed on the northern slopes of the islands, relatively more protected from the strong prevailing southwest winds, and nests at both colonies tended to be more protected on their southern side either by rocks or vegetation. Results obtained at Tierra del Fuego confirm the plasticity of microhabitat use by Kelp gulls, and their ability to take advantage of nesting sites according to availability and local environmental factors.     

Effect of repeated cycles of chemical disinfection on the roughness and hardness of hard reline acrylic resins

doi:10.1111/j.1741‐2358.2009.00282.x
Effect of repeated cycles of chemical disinfection on the roughness and hardness of hard reline acrylic resins Objective: The aim of this study was to assess the effect of repeated cycles of five chemical disinfectant solutions on the roughness and hardness of three hard chairside reliners. Methods: A total of 180 circular specimens (30 mm × 6 mm) were fabricated using three hard chairside reliners (Jet; n = 60, Kooliner; n = 60, Tokuyama Rebase II Fast; n = 60), which were immersed in deionised water (control), and five disinfectant solutions (1%, 2%, 5.25% sodium hypochlorite; 2% glutaraldehyde; 4% chlorhexidine gluconate). They were tested for Knoop hardness (KHN) and surface roughness (μm), before and after 30 simulated disinfecting cycles. Data was analysed by the factorial scheme (6 × 2), two‐way analysis of variance (anova ), followed by Tukey’s test. Results: For Jet (from 18.74 to 13.86 KHN), Kooliner (from 14.09 to 8.72 KHN), Tokuyama (from 12.57 to 8.28 KHN) a significant decrease in hardness was observed irrespective of the solution used on all materials. For Jet (from 0.09 to 0.11 μm) there was a statistically significant increase in roughness. Kooliner (from 0.36 to 0.26 μm) presented a statistically significant decrease in roughness and Tokuyama (from 0.15 to 0.11 μm) presented no statistically significant difference after 30 days. Conclusions: This study showed that all disinfectant solutions promoted a statistically significant decrease in hardness, whereas with roughness, the materials tested showed a statistically significant increase, except for Tokuyama. Although statistically significant values were registered, these results could not be considered clinically significant.     

Pathogenesis of Pulmonary Cryptococcus gattii Infection: A Rat Model

A model of pulmonary cryptococcosis in immunocompetent rats was developed to better understand the virulence of Cryptococcus gattii. Six isolates were studied, representing four molecular genotypes (VGI-MATα, VGIIa-MATα, VGIIa-MAT a, VGIIb-MATα), obtained from Australia, Vancouver (Canada) and Colombia. These originated from human patients, a cat and the environment and were administered intratracheally (i.t.) or transthoracically into Fischer 344 or Wistar-Furth rats in doses varying from 10⁴ to 10⁷ colony-forming units (CFU) in 0.1 ml of saline. With the exception of animals given the VGIIa-MAT a isolate, rats consistently became ill or died of progressive cryptococcal pneumonia following i.t. doses exceeding 10⁷ CFU. Affected lungs increased in weight up to tenfold and contained numerous circumscribed, gelatinous lesions. These became larger and more extensive, progressing from limited hilar and/or tracheal lesions, to virtually confluent gelatinous masses. Disease was localized to the lungs for at least 3–4 weeks, with dissemination to the brain occurring in some animals after day 29. The dose–response relationship was steep for two VGI isolates studied (human WM179, environmental WM276); doses up to 10⁶ CFU i.t. did not produce lesions, while 10⁷ or more yeast cells produced progressive pneumonia. Intratracheal inoculation of rats with C. gattii provides an excellent model of human pulmonary cryptococcosis in healthy hosts, mimicking natural infections. Disease produced by C. gattii in rats is distinct from that caused by C. neoformans in that infections are progressive and ultimately fatal.     

Superoxidedismutase-mimetic copper(II) complexes containing saccharinate and 4-aminopyridine/4-cyanopyridine

Two copper(II) complexes, [Cu(sac)₂(4-cypy)₂(H₂O)], 1 and [Cu(sac)₂(4-Ampy)₂(H₂O)], 2 (4-cypy: 4-cyanopyridine; 4-Ampy: 4-aminopyridine) were prepared. Physicochemical properties of the complexes were studied by spectroscopic (solution UV–vis, diffuse reflectance and IR) techniques. Structural X-ray diffraction data could be obtained only for [Cu(sac)₂(4-cypy)₂(H₂O)] that it crystallized in the tetragonal space group P4cc with a=b=15.313(1), c=13.240(1) Å, and Z=4 molecules per unit cell. The complex was cited on a crystallographic C₂-axis with the Cu(II) ion in a square–pyramidal environment, coordinated at the pyramid basis to the nitrogen atom of two saccharine anions [d(Cu–N)=2.011(3) Å] and the pyridine N-atom of two 4-cyanopyridine ligands [d(Cu–N)=2.038(4) Å]. The coordination was completed by a water molecule at the pyramid apex [d(Cu–Ow)=2.189(5) Å]. Elemental and spectroscopic analyses revealed an O-saccharinate coordination mode for complex 2 and a square–pyramidal structure. Only complex 2 retained its structure in methanolic solution. However, both complexes were able to catalyze the dismutation of superoxide anion (O₂^?) (pH 7.5) at micromolar concentrations. Therefore, these complexes behaved as useful SOD-mimetic compounds.     

Experimental solubility profiling of marketed CNS drugs, exploring solubility limit of CNS discovery candidate

We determined the experimental solubility of CNS marketed drugs. Of the 98 drugs measured, greater than 90% had solubility >10 μM in pH 7.4 buffer. Only seven drugs had solubility <10 μM. Using these data, we established a solubility criterion to support CNS discovery. The implication of poor solubility with potential safety concerns and undesirable side effects are discussed.     

Perspectives from Ten Years of Protist Studies by High‐Throughput Metabarcoding

During the last decade, high‐throughput metabarcoding became routine for analyzing protistan diversity and distributions in nature. Amid a multitude of exciting findings, scientists have also identified and addressed technical and biological limitations, although problems still exist for inference of meaningful taxonomic and ecological knowledge based on short DNA sequences. Given the extensive use of this approach, it is critical to settle our understanding on its strengths and weaknesses and to synthesize up‐to‐date methodological and conceptual trends. This article summarizes key scientific and technical findings, and identifies current and future directions in protist research that uses metabarcoding.     

Field collection of egg parasitoids of Pentatomidae and Scutelleridae in Northwest Italy and their efficacy in parasitizing Halyomorpha halys under laboratory conditions

The invasion of Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) has caused severe economic damage in crops in North America and Europe, motivating research to identify its natural enemies, both in native and invaded areas. In its Asian native range, the main natural enemies are egg parasitoids, among which the most effective are Trissolcus japonicus (Ashmead) and Trissolcus mitsukurii (Ashmead) (Hymenoptera: Scelionidae) in China and Japan, respectively. In Europe, biology, host range, and impact of most native scelionid species are not well‐known. The present study aimed to investigate (1) presence and abundance of scelionid species that parasitize native Pentatomidae and Scutelleridae eggs in Northwest Italy, and (2) their ability to develop on H. halys eggs. During 4‐year field surveys, egg masses were collected and reared until bug nymph or adult parasitoid emergence. Then, the obtained scelionid females were tested for their ability to parasitize H. halys eggs in laboratory no‐choice experiments. Egg masses of all collected bug species were parasitized, and Telenomus spp. (Hymenoptera: Scelionidae), Trissolcus belenus (Walker), and Anastatus bifasciatus (Geoffroy) (Hymenoptera: Eupelmidae) were the most common parasitoids. In the laboratory, Trissolcus kozlovi Rjachovskij was the only species to significantly produce offspring from fresh H. halys eggs, whereas all tested Trissolcus species significantly induced host egg abortion (non‐reproductive effects). This study provides knowledge of the parasitoid species associated with native bugs, and represents a starting point to investigate the intricate interactions between native and exotic parasitoids recently found in northern Italy. These egg parasitoids could potentially be effective biocontrol agents of H. halys.