The old metal-poor open cluster ESO 92-SC05: accreted from a dwarf galaxy ?

The study of old open clusters outside the solar circle can bring constraints on formation scenarios of the outer disc. In particular, accretion of dwarf galaxies has been proposed as a likely mechanism in the area. We use BVI photometry for determining fundamental parameters of the faint open cluster ESO 92-SC05. Colour-magnitude diagrams are compared with Padova isochrones, in order to derive age, reddening and distance. We derive a reddening E(B - V) = 0.17, and an old age of similar to 6.0 Gyr. It is one of the rare open clusters known to be older than 5 Gyr. A metallicity of Z similar to 0.004 or [M/H] similar to -0.7 is found. The rather low metallicity suggests that this cluster might be the result of an accretion episode of a dwarf galaxy.

Cycloheximide enhances factor binding to the native 40S ribosomal subunit of Microsporum canis

Native and derived ribosomal particles from the mycelial cells of Microsporum canis grown in the presence and absence of cycloheximide were compared by CsCl equilibrium density gradient centrifugation. Since the buoyant densities of ribonucleoprotein complexes are dependent on the protein-RNA ratio, they reflect the composition of these particles. The native monosomes from cells grown in the presence and absence of cycloheximide had a buoyant density of 1.585 g/cc. The native 60S subunits showed a density of 1.540 g/cc from cells grown in both presence and absence of cycloheximide, while the derived subunits showed a density of 1.610 g/cc. The derived 40S subunits had a density of 1.550 g/cc while the native 40S showed a major species of density 1.535 g/cc with three other minor species ranging in densities from 1.450-1.390 g/cc. The mycelia grown in the presence of cycloheximide showed an increased proportion of native 40S subunits in the density range of 1.450-1.390 g/cc, indicating that the drug enhances factor binding to native ribosomal subunits in M. canis.

Top predators as biodiversity regulators : the dingo Canis lupus dingo as a case study

Top-order predators often have positive effects on biological diversity owing to their key functional roles in regulating trophic cascades and other ecological processes. Their loss has been identified as a major factor contributing to the decline of biodiversity in both aquatic and terrestrial systems. Consequently, restoring and maintaining the ecological function of top predators is a critical global imperative. Here we review studies of the ecological effects of the dingo Canis lupus dingo, Australia's largest land predator, using this as a case study to explore the influence of a top predator on biodiversity at a continental scale. The dingo was introduced to Australia by people at least 3500 years ago and has an ambiguous status owing to its brief history on the continent, its adverse impacts on livestock production and its role as an ecosystem architect. A large body of research now indicates that dingoes regulate ecological cascades, particularly in arid Australia, and that the removal of dingoes results in an increase in the abundances and impacts of herbivores and invasive mesopredators, most notably the red fox Vulpes vulpes. The loss of dingoes has been linked to widespread losses of small and medium-sized native mammals, the depletion of plant biomass due to the effects of irrupting herbivore populations and increased predation rates by red foxes. We outline a suite of conceptual models to describe the effects of dingoes on vertebrate populations across different Australian environments. Finally, we discuss key issues that require consideration or warrant research before the ecological effects of dingoes can be incorporated formally into biodiversity conservation programs.

Ehrlichia canis em cães atendidos em hospital veterinário de Botucatu, Estado de São Paulo, Brasil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Detecção molecular de Ehrlichia canis em cães e em órgãos de seus respectivos carrapatos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Detecção molecular de Ehrlichia canis em cães e em órgãos de seus respectivos carrapatos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ecological genetics and conservation genomics of wolf (Canis lupus)

In the present work, we apply both traditional and Next Generation Sequencing (NGS) tools to investigate some of the most important adaptive traits of wolves (Canis lupus). In the first part, we analyze the variability of three Major Histocompatibility Complex (MHC) class II genes in the Italian wolf population, also studying their possible role in mating choice and their influence on fitness traits. In the second section, as part of a larger canid genome project, we will exploit NGS data to investigate the transcript-level differences between the wolf and the dog genome that can be correlated to domestication.

(Table 1) Lipid content and organohalogen contaminant concentration in captive sledge dogs (Canis familiaris) and wild female polar bears (Ursus maritimus) from Greenland

The limited knowledge and/or the inability to control physiological condition parameters that influence the fate of organohalogen contaminants (OHCs) has been the foremost confounding aspect in monitoring programs and health risk assessments of wild top predators in the Arctic such as the polar bear (Ursus maritimus). In the present comparative study, we used a potential surrogate Canoidea species for the East Greenland polar bear, the captive sledge dog (Canis familiaris), to investigate some factors that may influence the bioaccumulation and biotransformation of major chlorinated and brominated OHCs in adipose tissue and blood (plasma) of control (fed commercial pork fat) and exposed (fed West Greenland minke whale (Balaenoptera acutorostrata) blubber) adult female sledge dogs. Furthermore, we compared the patterns and concentrations of OHCs and their known or suggested hydroxylated (OH) metabolites (e.g., OH-PCBs) in sledge dogs with those in adipose tissue and blood (plasma) of East Greenland adult female polar bears, and blubber of their main prey species, the ringed seal (Pusa hispida). The two-year feeding regime conducted with sledge dogs led to marked differences in overall adipose tissue (and plasma) OHC residue accumulation between the control and exposed groups. Characteristic prey-to-predator OHC bioaccumulation dynamics for major PCB and PBDE congeners (patterns and concentrations) and biotransformation capacity with respect to PCB metabolite formation and OH-PCB retention distinguished, to some extent, captive sledge dogs and wild polar bears. Based on the present findings, we conclude that the use of surrogate species in toxicological investigations for species in the Canoidea family should be done with great caution, although they remain essential in the context of contaminants research with sensitive arctic top carnivore species such as the polar bear.

An abundantly expressed mucin-like protein from Toxocara canis infective larvae: the precursor of the larval surface coat glycoproteins.

Evasion of host immunity by Toxocara canis infective larvae is mediated by the nematode surface coat, which is shed in response to binding by host antibody molecules or effector cells. The major constituent of the coat is the TES-120 glycoprotein series. We have isolated a 730-bp cDNA from the gene encoding the apoprotein precursor of TES-120. The mRNA is absent from T. canis adults but hyperabundant in larvae, making up approximately 10% of total mRNA, and is trans-spliced with the nematode 5' leader sequence SL1. It encodes a 15.8-kDa protein (after signal peptide removal) containing a typical mucin domain: 86 amino acid residues, 72.1% of which are Ser or Thr, organized into an array of heptameric repeats, interspersed with proline residues. At the C-terminal end of the putative protein are two 36-amino acid repeats containing six Cys residues, in a motif that can also be identified in several genes in Caenorhabditis elegans. Although TES-120 displays size and charge heterogeneity, there is a single copy gene and a homogeneous size of mRNA. The association of overexpression of some membrane-associated mucins with immunosuppression and tumor metastasis suggests a possible model for the role of the surface coat in immune evasion by parasitic nematodes.

(Table 1) Organohalogen contaminants in adipose tissue of captive sledge dogs (Canis familiaris) fed with whale blubber or pork fat

Studies on the fate of organohalogen contaminants (OHCs) in wild top predator mammals in the Arctic have often been a challenge due to important knowledge deficiencies in the life history of the sampled animals. The present study investigated the influence of age, dietary and trans-generational factors on the fate of major lipophilic chlorinated and brominated OHCs in adipose tissue of a potential surrogate captive species for the polar bear (Ursus maritimus), the sledge dog (Canis familiaris) in West Greenland. Adult female sledge dogs (P) and their sexually-mature (F1) and/or pre-weaning pups (F1-MLK) were divided into an exposed group (EXP) fed blubber from a Greenland minke whale (Balaenoptera acutorostrata) and a control group (CON) given commercially available pork fat. Large dietary treatment-related differences in summed and individual congener/compound adipose tissue concentrations of polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB), chlordanes (CHLs) and polychlorinated biphenyls (PCBs) were found between the EXP and CON groups for all the sledge dog cohorts. However, among the F1-MLK, F1 and P dogs in both of the EXP and CON groups, little or no difference existed in PBDE, HCB, CHL and PCB concentrations, suggesting higher state of equilibrium in adipose tissue concentrations from a very early stage of life. In contrast, the distribution pattern (proportions to the summed concentrations) of OHC classes, and the major congeners/ compounds constituting those classes, varied on a dietary group- and/or cohort-dependent manner. The present captive sledge dog study demonstrated the importance of the confounding effects of diet composition, mother-pup association (maternal transfer), reproductive status (nursing), and to a lesser extent age in the fate of OHCs in adipose tissue of a large top carnivore mammal.

Guidelines on building design and operation to minimize air quality impacts from major roads in transit oriented development

Poor air quality has a huge detrimental effect, both economic and on the quality of life, in Australia. Transit oriented design (TOD), which aims to minimise urban sprawl and lower dependency on vehicles, leads to an increasing number of buildings close to transport corridors. This project aims at providing guidelines that are appropriate to include within City Plan to inform future planning along road corridors, and provide recommendations on when mitigation measures should be utilised.