Full Tècnic. Conreus Extensius. Comarques de Girona, núm. 14 (2008)

El sorgo per a gra és una planta rústica, interessant principalment en les situacions on la disponibilitat d’aigua és limitada: • En secà, pot presentar rendibilitats superiors al gira-sol, en els terrenys més fèrtils i amb una bona reserva hídrica. • En regadiu, pot donar rendibilitats superiors al blat de moro, quan l’aigua que es disposa és marcadament insuficient per cobrir les necessitats d’aquest conreu.

Groupes diagnostiques utilisés sur SIMULIT 14

Un premier exercice avait proposé un regroupement des diagnostics pour la planification des lits. Ce regroupement avait été établi empiriquement sur une base de données provenant des hôpitaux de zone vaudois (1983-1984). Lorsqu'il s'est agi d'appliquer cette grille au Centre Hospitalier Universitaire Vaudois (CHUV), il est rapidement apparu que la structure de la clientèle d'un tel hôpital rendait indispensable le remaniement de la grille descriptive. C'est l'objet du présent cahier... [Auteurs]

A simple genetic basis for complex social behaviour mediates widespread gene expression differences.

A remarkable social polymorphism is controlled by a single Mendelian factor in the fire ant Solenopsis invicta. A genomic element marked by the gene Gp-9 determines whether workers tolerate one or many fertile queens in their colony. Gp-9 was recently shown to be part of a supergene with two nonrecombining variants, SB and Sb. SB/SB and SB/Sb queens differ in how they initiate new colonies, and in many physiological traits, for example odour and maturation rate. To understand how a single genetic element can affect all these traits, we used a microarray to compare gene expression patterns between SB/SB and SB/Sb queens of three different age classes: 1-day-old unmated queens, 11-day-old unmated queens and mated, fully reproductive queens collected from mature field colonies. The number of genes that were differentially expressed between SB/SB and SB/Sb queens of the same age class was smallest in 1-day-old queens, maximal in 11-day-old queens and intermediate in reproductive queens. Gene ontology analysis showed that SB/SB queens upregulate reproductive genes faster than SB/Sb queens. For all age classes, genes inside the supergene were overrepresented among the differentially expressed genes. Consistent with the hypothesized greater number of transposons in the Sb supergene, 13 transposon genes were upregulated in SB/Sb queens. Viral genes were also upregulated in SB/Sb mature queens, consistent with the known greater parasite load in colonies headed by SB/Sb queens compared with colonies headed by SB/SB queens. Eighteen differentially expressed genes between reproductive queens were involved in chemical signalling. Our results suggest that many genes in the supergene are involved in regulating social organization and queen phenotypes in fire ants.

MC1R-dependent, melanin-based colour polymorphism is associated with cell-mediated response in the Eleonora's falcon.

Colour polymorphism in vertebrates is usually under genetic control and may be associated with variation in physiological traits. The melanocortin 1 receptor (Mc1r) has been involved repeatedly in melanin-based pigmentation but it was thought to have few other physiological effects. However, recent pharmacological studies suggest that MC1R could regulate the aspects of immunity. We investigated whether variation at Mc1r underpins plumage colouration in the Eleonora's falcon. We also examined whether nestlings of the different morphs differed in their inflammatory response induced by phytohemagglutinin (PHA). Variation in colouration was due to a deletion of four amino acids at the Mc1r gene. Cellular immune response was morph specific. In males, but not in females, dark nestling mounted a lower PHA response than pale ones. Although correlative, our results raise the neglected possibility that MC1R has pleiotropic effects, suggesting a potential role of immune capacity and pathogen pressure on the maintenance of colour polymorphism in this species.

Compartmentalized Cerebral Metabolism of [1,6-(13)C]Glucose Determined by in vivo (13)C NMR Spectroscopy at 14.1 T.

Cerebral metabolism is compartmentalized between neurons and glia. Although glial glycolysis is thought to largely sustain the energetic requirements of neurotransmission while oxidative metabolism takes place mainly in neurons, this hypothesis is matter of debate. The compartmentalization of cerebral metabolic fluxes can be determined by (13)C nuclear magnetic resonance (NMR) spectroscopy upon infusion of (13)C-enriched compounds, especially glucose. Rats under light α-chloralose anesthesia were infused with [1,6-(13)C]glucose and (13)C enrichment in the brain metabolites was measured by (13)C NMR spectroscopy with high sensitivity and spectral resolution at 14.1 T. This allowed determining (13)C enrichment curves of amino acid carbons with high reproducibility and to reliably estimate cerebral metabolic fluxes (mean error of 8%). We further found that TCA cycle intermediates are not required for flux determination in mathematical models of brain metabolism. Neuronal tricarboxylic acid cycle rate (V(TCA)) and neurotransmission rate (V(NT)) were 0.45 ± 0.01 and 0.11 ± 0.01 μmol/g/min, respectively. Glial V(TCA) was found to be 38 ± 3% of total cerebral oxidative metabolism, accounting for more than half of neuronal oxidative metabolism. Furthermore, glial anaplerotic pyruvate carboxylation rate (V(PC)) was 0.069 ± 0.004 μmol/g/min, i.e., 25 ± 1% of the glial TCA cycle rate. These results support a role of glial cells as active partners of neurons during synaptic transmission beyond glycolytic metabolism.

Vitamin D deficiency and a CYP27B1-1260 promoter polymorphism are associated with chronic hepatitis C and poor response to interferon-alfa based therapy

BACKGROUND: Vitamin D is an important immune modulator and preliminary data indicated an association between vitamin D deficiency and sustained virologic response (SVR) rates in patients with chronic hepatitis C. We therefore performed a comprehensive analysis on the impact of vitamin D serum levels and of genetic polymorphisms within the vitamin D cascade on chronic hepatitis C and its treatment. METHODS: Vitamin D serum levels, genetic polymorphisms within the vitamin D receptor and the 1α- hydroxylase were determined in a cohort of 468 HCV genotype 1, 2 and 3 infected patients who were treated with interferon-alfa based regimens. RESULTS: Chronic hepatitis C was associated with a high incidence of severe vitamin D deficiency compared to controls (25(OH)D3<10 ng/mL in 25% versus 12%, p<0.00001), which was in part reversible after HCV eradication. 25(OH)D3 deficiency correlated with SVR in HCV genotype 2 and 3 patients (63% and 83% SVR for patients with and without severe vitamin D deficiency, respectively, p<0.001). In addition, the CYPB27-1260 promoter polymorphism rs10877012 had substantial impact on 1-25- dihydroxyvitamin D serum levels and SVR rates in HCV genotype 1, 2 and 3 infected patients. CONCLUSIONS: Chronic hepatitis C virus infection is associated with vitamin D deficiency. Reduced 25- hydroxyvitamin D levels and CYPB27-1260 promoter polymorphism are associated with failure to achieve SVR in HCV genotype 1, 2, 3 infected patients.

Strongyloides ferreirai Rodrigues, Vicente & Gomes, 1985 (Nematoda, Rhabdiasoidea) in rodent coprolites (8.000-2.000 years BP), from archaeological sites from Piauí, Brazil

Eggs and larvae of Strongyloides ferreirai Rodrigues, Vicente & Gomes, 1985 are identified in Kerodon rupestris (Wied.) coprolites dated from 8.000-2.000 years BP (Before Present), collected from archaeological sites from the northeast of Brazil.

Phylogeographical footprints of the Strait of Gibraltar and Quaternary climatic fluctuations in the western Mediterranean: a case study with the greater white-toothed shrew, Crocidura russula (Mammalia: Soricidae).

We used mitochondrial cyt b sequences to investigate the phylogenetic relationships of Crocidura russula (sensu lato) populations across the Strait of Gibraltar, western Europe, Maghreb, and the Mediterranean and Atlantic islands. This revealed very low genetic divergence between European and Moroccan populations. The application of a molecular clock previously calibrated for shrews suggested that the separation of European from Moroccan lineages occurred less than 60 000 bp, which is at least 5 million years (Myr) after the reopening of the Strait of Gibraltar. This means that an overwater dispersal event was responsible for the observed phylogeographical structure. In contrast, genetic analyses revealed that Moroccan populations were highly distinct from Tunisian ones. According to the molecular clock, these populations separated about 2.2 million years ago (Ma), a time marked by sharp alternations of dry and humid climates in the Maghreb. The populations of the Mediterranean islands Ibiza, Pantelleria, and Sardinia were founded from Tunisian populations by overwater dispersal. In conclusion, overwater dispersal across the Strait of Gibraltar, probably assisted by humans, is possible for small terrestrial vertebrates. Moreover, as in Europe, Quaternary climatic fluctuations had a major effect on the phylogeographical structure of the Maghreb biota.

Species identification in mammals from mixed biological samples based on mitochondrial DNA control region length polymorphism.

The ability to identify the species origin of an unknown biological sample is relevant in the fields of human and wildlife forensics. However, the detection of several species mixed in the same sample still remains a challenge. We developed and tested a new approach for mammal DNA identification in mixtures of two or three species, based on the analysis of mitochondrial DNA control region interspecific length polymorphism followed by direct sequencing. Contrary to other published methods dealing with species mixtures, our protocol requires a single universal primer pair and is not based on a pre-defined panel of species. Amplicons can be separated either on agarose gels or using CE. The advantages and limitations of the assay are discussed under different conditions, such as variable template concentration, amplicon sizes and size difference among the amplicons present in the mixture. For the first time, this protocol provides a simple, reliable and flexible method for simultaneous identification of multiple mammalian species from mixtures, without any prior knowledge of the species involved.

Influence of climate on the presence of colour polymorphism in two montane reptile species.

The coloration of ectotherms plays an important role in thermoregulation processes. Dark individuals should heat up faster and be able to reach a higher body temperature than light individuals and should therefore have benefits in cool areas. In central Europe, montane local populations of adder (Vipera berus) and asp viper (Vipera aspis) exhibit a varying proportion of melanistic individuals. We tested whether the presence of melanistic V. aspis and V. berus could be explained by climatic conditions. We measured the climatic niche position and breadth of monomorphic (including strictly patterned individuals) and polymorphic local populations, calculated their niche overlap and tested for niche equivalency and similarity. In accordance with expectations, niche overlap between polymorphic local populations of both species is high, and even higher than that of polymorphic versus monomorphic montane local populations of V. aspis, suggesting a predominant role of melanism in determining the niche of ectothermic vertebrates. However, unexpectedly, the niche of polymorphic local populations of both species is narrower than that of monomorphic ones, indicating that colour polymorphism does not always enable the exploitation of a greater variability of resources, at least at the intraspecific level. Overall, our results suggest that melanism might be present only when the thermoregulatory benefit is higher than the cost of predation.

Lack of directed V alpha 14-J alpha 281 rearrangements in NK1+ T cells.

NK1.1+ T cells are an unusual subset of TCR alpha beta cells distinguished by their highly restricted V beta repertoire and predominant usage of an invariant V alpha 14-J alpha 281 chain. To assess whether a directed rearrangement mechanism could be responsible for this invariant alpha chain, we have analyzed V alpha 14 rearrangements by polymerase chain reaction and Southern blot in a panel of cloned T-T hybrids derived from thymic NK1.1+ T cells. As expected a high proportion (17/20) of the hybrids had rearranged V alpha 14 to J alpha 281. However, V alpha 14-J alpha 281 rearrangements always occurred on only one chromosome and were accompanied by other V alpha-J alpha rearrangements (not involving V alpha 14) on the homologous chromosome. These data argue that rigorous ligand selection rather than directed rearrangement is responsible for the high frequency of V alpha 14-J alpha 281 rearrangements in NK1.1+ T cells.