Instabilities in the wake of an inclined prolate spheroid

We investigate the instabilities, bifurcations and transition in the wake behind a 45-degree inclined 6:1 prolate spheroid, through a series of direct numerical simulations (DNS) over a wide range of Reynolds numbers (Re) from 10 to 3000. We provide a detailed picture of how the originally symmetric and steady laminar wake at low Re gradually looses its symmetry and turns unsteady as Re is gradually increased. Several fascinating flow features have first been revealed and subsequently analysed, e.g. an asymmetric time-averaged flow field, a surprisingly strong side force etc. As the wake partially becomes turbulent, we investigate a dominating coherent wake structure, namely a helical vortex tube, inside of which a helical symmetry alteration scenario was recovered in the intermediate wake, together with self-similarity in the far wake.Comment: Book chapter in "Computational Modeling of Bifurcations and Instabilities in Fluid Dynamics (A. Gelfgat ed.)", Springe

Prevalence of <em>Cryptosporidium</em> spp. and <em>Giardia</em> spp. in cattle in the Setif region of Northeastern Algeria

The prevalence of Cryptosporidium spp. and Giardia spp. in cattle was studied in 13 dairy farms in the Setif region of Northeastern Algeria. A total of 634 fecal samples were col­lected from 302 calves and 332 adults. Cryptosporidium spp. was identified in nine farms (69.2%) and 22% of animals. The parasite was observed in all age groups but with a higher prevalence in calves aged 4–30 days (p < 0.01). Cryptosporid­ium spp. oocyst excretion was highly significantly associated with diarrheas, with a higher prevalence in calves under 30 days of age (p < 0.001). Giardia spp. was identified in 53.8% of farms and 13.8% of animals. Contrary to Cryptosporidium spp., infection by Giardia spp. seemed higher in older calves (4–12 months) (p < 0.05). No significant link was established between Giardia spp. cyst excretion and the type of feces. The presence of both parasites was revealed in 10.2% of diarrheic calves. This work shows the importance of Cryptosporidium spp. and, for the first time, that of Giardia spp. in dairy cattle of the region of Setif

Effect of feed on the milk protein and fat composition

Abstract. Feed is considered the most important factor affecting the composition of cow’s milk of which the quality can be evaluated, essentially, through two parameters, the fat and protein content, because of their industrial interest. This study aims to evaluate the impact of seven different rations (R1-R7) on the protein and fat content of Prim’holstein cow milk in a cattle farm in Algiers. The results showed that the dry matter (DM) content of forages and concentrate was 72.74% (62.94% - 81.49%) and 27.25% (18.51% - 37.06%), respectively. The forage unit milk (FUM) and the digestible nitrogen matter (DNM) contents of forage were 60.50% (51.37% - 72.08%) and 61.15% (46.73% - 74.63%), respectively. In concentrate, the FUM and DNM contents were 39.50% (24.85 - 51.5%) and 38.85% (25.37 - 52.39%), respectively (Table 3). The forages showed significantly higher DM, FUM and DNM contents than the concentrate (p<0.0001). The type of ration showed a highly significant effect on the quantity of milk produced per day, protein content and defatted dry matter. However, no significant influence was observed for the fat content. The highest milk production (ranging from 17.31 to 19.64 liters/day) and the highest defatted dry matter (87.03 and 87.92 g/l) were recorded in cows which received rations R2, R3, R4 and R5 (p<0.0001). The highest protein content values (32.87 and 33.20 g/l) were observed in the milk of cows that were fed with rations R2, R3 and R4. The lowest levels were observed for rations R6 (31.80 g/l) and R7 (31.22 g/l) (p<0.0001). Protein to fat content ratio ranged from 0.79 to 0.84 and fat to protein content ratio ranged from 1.19 to 1.27. Good management of the diet and feeding practices of the dairy cows allow having an adequate protein and fat content in the milk. A diet composed of forages with an adequate supplementation in concentrate leads to the optimal results. Further studies are important to evaluate the effect of the physical form of the diet on the physicochemical quality of the milk

Somatic Mutations in MLH1 and MSH2 Are a Frequent Cause of Mismatch-Repair Deficiency in Lynch Syndrome-Like Tumors

Contains fulltext : 136846pub.pdf (publisher's version ) (Closed access)Lynch syndrome is caused by germline mutations in the mismatch repair (MMR) genes. Tumors are characterized by microsatellite instability (MSI). However, a considerable number of MSI-positive tumors have no known molecular mechanism of development. By using Sanger and ion semiconductor sequencing, 25 MSI-positive tumors were screened for somatic mutations and loss of heterozygosity in mutL homolog 1 (MLH1) and mutS homolog 2 (MSH2). In 13 of 25 tumors (8 MLH1-deficient and 5 MSH2-deficient tumors), we identified 2 somatic mutations in these genes. We conclude that 2 acquired events explain the MMR-deficiency in more than 50% of the MMR-deficient tumors without causal germline mutations or promoter methylation

Universal Tumor DNA BRCA1/2 Testing of Ovarian Cancer: Prescreening PARPi Treatment and Genetic Predisposition

Contains fulltext : 218615pub.pdf (publisher's version ) (Open Access)BACKGROUND: Women with epithelial ovarian cancer (OC) have a higher chance to benefit from poly (ADP-ribose) polymerase inhibitor (PARPi) therapy if their tumor has a somatic or hereditary BRCA1/2 pathogenic variant. Current guidelines advise BRCA1/2 genetic predisposition testing for all OC patients, though this does not detect somatic variants. We assessed the feasibility of a workflow for universal tumor DNA BRCA1/2 testing of all newly diagnosed OC patients as a prescreen for PARPi treatment and cancer predisposition testing. METHODS: Formalin-fixed paraffin-embedded tissue was obtained from OC patients in seven hospitals immediately after diagnosis or primary surgery. DNA was extracted, and universal tumor BRCA1/2 testing was then performed in a single site. Diagnostic yield, uptake, referral rates for genetic predisposition testing, and experiences of patients and gynecologists were evaluated. RESULTS: Tumor BRCA1/2 testing was performed for 315 (77.6%) of the 406 eligible OC samples, of which 305 (96.8%) were successful. In 51 of these patients, pathogenic variants were detected (16.7%). Most patients (88.2%) went on to have a genetic predisposition test. BRCA1/2 pathogenic variants were shown to be hereditary in 56.8% and somatic in 43.2% of patients. Participating gynecologists and patients were overwhelmingly positive about the workflow. CONCLUSIONS: Universal tumor BRCA1/2 testing in all newly diagnosed OC patients is feasible, effective, and appreciated by patients and gynecologists. Because many variants cannot be detected in DNA from blood, testing tumor DNA as the first step can double the identification rate of patients who stand to benefit most from PARP inhibitors