Probing the Cosmological Principle in the counts of radio galaxies at different frequencies

According to the Cosmological Principle, the matter distribution on very large scales should have a kinematic dipole that is aligned with that of the CMB. We determine the dipole anisotropy in the number counts of two all-sky surveys of radio galaxies. For the first time, this analysis is presented for the TGSS survey, allowing us to check consistency of the radio dipole at low and high frequencies by comparing the results with the well-known NVSS survey. We match the flux thresholds of the catalogues, with flux limits chosen to minimise systematics, and adopt a strict masking scheme. We find dipole directions that are in good agreement with each other and with the CMB dipole. In order to compare the amplitude of the dipoles with theoretical predictions, we produce sets of lognormal realisations. Our realisations include the theoretical kinematic dipole, galaxy clustering, Poisson noise, simulated redshift distributions which fit the NVSS and TGSS source counts, and errors in flux calibration. The measured dipole for NVSS is $\sim\!2$ times larger than predicted by the mock data. For TGSS, the dipole is almost $\sim\! 5$ times larger than predicted, even after checking for completeness and taking account of errors in source fluxes and in flux calibration. Further work is required to understand the nature of the systematics that are the likely cause of the anomalously large TGSS dipole amplitude.Comment: 13 pages, 8 figures, 2 tables; Significant improvements. Version accepted by JCA

Forecasting cosmological constraints from age of high-z galaxies

We perform Monte Carlo simulations based on current age estimates of high-z objects to forecast constraints on the equation of state (EoS) of the dark energy. In our analysis, we use two different EoS parameterizations, namely, the so-called CPL and its uncorrelated form and calculate the improvements on the figure of merit for both cases. Although there is a clear dependence of the FoM with the size and accuracy of the synthetic age samples, we find that the most substantial gain in FoM comes from a joint analysis involving age and baryon acoustic oscillation data.Comment: 4 pages, 13 figures, late

The dipole anisotropy of WISE x SuperCOSMOS number counts

We probe the isotropy of the Universe with the largest all-sky photometric redshift dataset currently available, namely WISE~$\times$~SuperCOSMOS. We search for dipole anisotropy of galaxy number counts in multiple redshift shells within the $0.10 < z < 0.35$ range, for two subsamples drawn from the same parent catalogue. Our results show that the dipole directions are in good agreement with most of the previous analyses in the literature, and in most redshift bins the dipole amplitudes are well consistent with $\Lambda$CDM-based mocks in the cleanest sample of this catalogue. In the $z<0.15$ range, however, we obtain a persistently large anisotropy in both subsamples of our dataset. Overall, we report no significant evidence against the isotropy assumption in this catalogue except for the lowest redshift ranges. The origin of the latter discrepancy is unclear, and improved data may be needed to explain it.Comment: 5 pages, 4 figures, 2 tables. Published in MNRA

Influence d'une infection expérimentale à Trypanosoma congolense sur la fonction sexuelle des béliers Djallonké et Sahéliens en zone subhumide

Influence of an experimental Trypanosoma congolense infection on the reproductive function of Djallonké and Sahelian rams in subhumid zone. To measure the effect of African animal trypanosomosis (AAT) on male reproductive function, eight 18-24 month old Djallonké (ID; 31.2 ± 2.95 kg) and Sahelian (IS; 41.7 ± 4.64 kg) rams were infected with 104 Trypanosoma congolense. Eight other Djallonké (CD) and Sahelian (CS) rams with similar bodyweight and ages were used as uninfected controls. Four weeks after infection, ID and IS were treated with a trypanocidal drug, while maintained under observation. The evolution of clinical parameters shows a higher aptitude of Djallonké than Sahelian to control the effects of infection. This interbreed difference in susceptibility to AAT was confirmed by the higher weight losses in IS (-31.3 g) when compared to ID (-12.8 g) as to CD and CS rams. The effect of a T. congolense infection consisted in a decreased libido in IS (33 s) when compared to ID (22.1 s) (P &gt; 0.05). The results indicate a significant effect of breed on ejaculate volume (CS: 1.23 ml vs CD: 0.88 ml; P &lt; 0.05). Otherwise, breed did not significantly affect the other spermatic parameters. CD sperm cells concentration (3,293.4 x 106.ml-1), total abnormality rate (15.3%), dead sperm cells rate (13.9%), mobile sperm cells rate (75.5%), individual (3.76) and mass motilities (3.94) did not differ (P &gt; 0.05) from those of CS (respectively 3,481.7 x 106.ml-1; 17.3%; 12.4%; 74.9%; 3.77; 3.36). However, the later produced 26% more total sperm cells than CD (P &gt; 0.05). The infection reduced ejaculate volume by 15.8 and 14.5%, (P &gt; 0.05), production of total sperm cells by 18.2 and 13.3% (P &gt; 0.05) and the rate of mobile sperm cells by 14.2 and 27.9% (P &lt; 0.05) respectively for Djallonké and Sahelian rams. The results show a dysfunctional state of testicles due to the harmful effects of AAT infection, hence the increase in dead sperm cells by 69.8 and 74.3% (P &gt; 0.05) and in the rate of total abnormal sperm cells by 23.6 and 24.1% (P &gt; 0.05) respectively for ID and IS rams when compared respectively to CD and CS animals. Harmful effects often more pronounced in Sahelian breeds during this experiment could indicate a higher susceptibility of this breed to AAT in comparison with Djallonké. One Sahelian ram died two weeks post-infection and azoospermia was observed in another one six weeks after chemotherapy and the disappearance of parasites from the bloodstream

Integrating farmers' knowledge, attitude and practice in the development of sustainable Striga control interventions in southern Mali

Technologies for Striga control have not been widely adopted because of the mis-match between technologies and farmers' socio- economic conditions. This study uses a participatory rural appraisal technique at the village, household and plot levels to diagnose the extent of the Striga problem in two agro- ecological zones in southern Mali. It has led to the understanding of farmers' attitudes and constraints to Striga control, and opportunities for the development of sustainable technologies suitable for a wide range of farming conditions. Results show that the degree of Striga infestation, levels of farmer knowledge and control practices vary substantially across village territories and fields, and that the severity of the infestation is clearly linked with soil fertility condition and farming practices. It was concluded that in general, the Striga control interventions that would most likely appeal to farmers would be those that will simultaneously improve soil fertility and suppress the development of Striga

The trypanocidal benzoxaborole AN7973 inhibits trypanosome mRNA processing

Kinetoplastid parasites—trypanosomes and leishmanias—infect millions of humans and cause economically devastating diseases of livestock, and the few existing drugs have serious deficiencies. Benzoxaborole-based compounds are very promising potential novel anti-trypanosomal therapies, with candidates already in human and animal clinical trials. We investigated the mechanism of action of several benzoxaboroles, including AN7973, an early candidate for veterinary trypanosomosis. In all kinetoplastids, transcription is polycistronic. Individual mRNA 5'-ends are created by trans splicing of a short leader sequence, with coupled polyadenylation of the preceding mRNA. Treatment of Trypanosoma brucei with AN7973 inhibited trans splicing within 1h, as judged by loss of the Y-structure splicing intermediate, reduced levels of mRNA, and accumulation of peri-nuclear granules. Methylation of the spliced leader precursor RNA was not affected, but more prolonged AN7973 treatment caused an increase in S-adenosyl methionine and methylated lysine. Together, the results indicate that mRNA processing is a primary target of AN7973. Polyadenylation is required for kinetoplastid trans splicing, and the EC50 for AN7973 in T. brucei was increased three-fold by over-expression of the T. brucei cleavage and polyadenylation factor CPSF3, identifying CPSF3 as a potential molecular target. Molecular modeling results suggested that inhibition of CPSF3 by AN7973 is feasible. Our results thus chemically validate mRNA processing as a viable drug target in trypanosomes. Several other benzoxaboroles showed metabolomic and splicing effects that were similar to those of AN7973, identifying splicing inhibition as a common mode of action and suggesting that it might be linked to subsequent changes in methylated metabolites. Granule formation, splicing inhibition and resistance after CPSF3 expression did not, however, always correlate and prolonged selection of trypanosomes in AN7973 resulted in only 1.5-fold resistance. It is therefore possible that the modes of action of oxaboroles that target trypanosome mRNA processing might extend beyond CPSF3 inhibition

Efficiency of common washing treatments in reducing microbial levels on lettuce in Mali

Lettuce is one of the most cultivated vegetables (eaten raw) in Mali with a percentage of 69.4 amongst leafy vegetables and 30.4 of all vegetables. Vegetables consumed raw, particularly lettuce, are sources of foodborne pathogens. This study was conducted to assess bacterial contamination of unwashed lettuce and the efficiency of disinfecting it with tap water and varying concentrations of some chemical disinfectants: bleach (0.00285, 0.00570 and 0.00855 ppm), potassium permanganate (170, 340 and 510 ppm), vinegar (0.00285, 0.00570 and 0.00855 ppm) and common salt (500, 1000 and 1500 ppm) based on the three consecutive washing protocol recommended for vegetables in Mali. Lettuce samples were randomly selected from farms irrigated with untreated river water within communities five and six in Bamako. Lettuce leaves were exposed to low concentration of the chemical disinfectants at 15 min, intermediate at 10 min and high at 5 min. A bleach (0.00285 ppm)/vinegar (0.00285 ppm) combination disinfection was also tested at 15 min. Tap water, bleach, potassium permanganate, vinegar and common salt reduced faecal coliform populations by 1.3–2.9, 1.5–3.0 and 1.9–3.5 log CFU/100 g, at 5, 10 and 15 min, respectively. Disinfection treatment using bleach (0.00285 ppm) was found to be more effective than other disinfectants at all contact times. All the disinfectants reduced Escherichia coli populations by 2.0–2.8 log CFU/100 g on lettuce and completely eliminated Salmonella spp. at all treatment contact times. Disinfection treatment using bleach/vinegar combination at 15 min also reduced faecal coliform populations on lettuce by 2.8 log CFU/100 g and completely eliminated E. coli and Salmonella spp. All chemical disinfectants including tap water at 15 min reduced faecal coliform populations below the undesirable ICMSF (2011) level (1000 CFU/100 g wet weight). These could contribute to reduce the health risk associated with the consumption of lettuce in Mali