212 research outputs found
Implicit integration scheme for porous viscoplastic potential-based constitutive equations
This paper deals with a viscoplastic potential-based model allowing thermomechanical damage behavior modeling of porous materials. The model describes rate dependent effects, hardening, creep as well as defects coalescence and propagation. Kinematic and isotropic hardening effects are taken into account by a set of internal state variables. The integration and implementation of the model into the FE code using a fully implicit integration scheme is exposed. Finally, it 19s used to predict mechanical behaviour degradation of solder layers used in power electronic packaging. Stress-strain behaviour and the evolution of volumic fraction of voids for the material under cyclic loading are presented
Detection of tet(M) gene from raw milk by rapid DNA extraction followed by a two-step PCR with nested primers.
The likelihood that milk and milk products may act as a vehicle for antibiotic-resistant bacterial genes has become a concern to the food industry and a public health issue, and the demand for rapid tests has increased. The purity of DNA extracted from food samples is a key issue in the sensitivity and usefulness of biological analyses, such as PCR for pathogens and nonpathogens. A rapid, phenol-chloroform free method based on a modification of a sodium iodide DNA extraction, followed by a two-step PCR was developed for direct detection of the tet(M) gene in milk samples within a single working day. This study compares the proposed method with a traditional phenol solvent extraction method and with a commercial kit (QIAamp DNA blood mini kit, Qiagen). The three DNA extraction methods were used to ensure access to the tet(M) gene from 1 ml of raw milk, inoculated with a strain of Enterococcus faecalis, which carries the tet(M) gene. The proposed method, followed by a two-step PCR with nested primers specific for the tet(M) gene, was able to reach a detection limit below 10 CFU/ml in less than 4 h, including the two amplification cycles, thus outperforming in sensitivity and rapidity both the traditional and the commercial method
In-situ Analysis of Laminated Composite Materials by X-ray Micro-Computed Tomography and Digital Volume Correlation
The complex mechanical behaviour of composite materials, due to internal heterogeneity and multi-layered composition impose deeper studies. This paper presents an experimental investigation technique to perform volume kinematic measurements in composite materials. The association of X-ray micro-computed tomography acquisitions and Digital Volume Correlation (DVC) technique allows the measurement of displacements and deformations in the whole volume of composite specimen. To elaborate the latter, composite fibres and epoxy resin are associated with metallic particles to create contrast during X-ray acquisition.
A specific in situ loading device is presented for three-point bending tests, which enables the visualization of transverse shear effects in composite structures
Characterization and growth under different storage temperatures of ropy slime-producing leuconostoc mesenteroides isolated from cooked meat products
Enterotoxin production by Staphylococcus aureus isolated from mastitic cows.
Staphylococcus aureus is an important cause of mastitis in cows. The ability of S. aureus strains to produce one or more enterotoxins in milk and dairy products is linked to staphylococcal food poisoning. To determine whether staphylococci causing bovine mastitis could cause human foodborne intoxication, the production of staphylococcal enterotoxins A through D (SEA, SEB, SEC, and SED) by 160 S. aureus isolates was evaluated with the use of a reverse passive latex agglutination enterotoxin kit. All S. aureus strains were isolated over a 9-month period from 2,343 routine submissions of a composite quarter collection of individual mastitic cows at 18 dairy farms in the San Joaquin Valley in California. Prior to enterotoxin detection, isolates were grown by a method that enhances the in vitro synthesis of enterotoxin. Twenty-two of 160 S. aureus isolates produced enterotoxin. Seven produced SEC, 12 produced SED, and 3 produced both SEC and SED. None of the isolates produced SEA or SEB
Roles of Traditional Birth Attendants and Perceptions on the Policy Discouraging Home Delivery in Coastal Kenya
Objectives: To describe the roles of Traditional Birth Attendants (TBAs), to determine the perceptions of TBAs and Skilled Birth Attendants (SBAs) towards the policy discouraging home delivery by TBAs and to establish the working relationship between TBAs and SBAs in Kwale, Kenya.Design: Community based cross-sectional study.Setting: Mwaluphamba, Kinango and Golini locations of Kwale County, Kenya.Subjects: Fifty eight participants were involved in the study. Interviews were conducted with 22 TBAs and 8 SBAs as well as 3 FGDs with 28 TBAs were carried out in July 2012.Main outcome measures: Roles of TBAs, policy awareness and support as well as the working relationship between TBAs and SBAs.Results: Before delivery, the main role of TBAs was checking position of the baby in the womb (86%) while during delivery, the main role was stomach massage (64%). However, majority (95%) of the TBAs did not provide any after delivery. All SBAs and 59% of TBAs were aware of the policy while 88% SBAs and 36% of TBAs supported it. The working relationship between TBAs and SBAs mainly involved the referral of women to health facilities (HFs). Sometimes, TBAs accompanied women to the HFoffering emotional support until after delivery.Conclusion: TBAs in Kwale have a big role to play especially during pregnancy and delivery periods. Awareness and support of the policy as well as the collaboration between SBAs and TBAs should be enhanced in Kwale
KORELASI GENOTIPIK ANTARA HASIL DENGAN TINGKAT KETAHANAN TERHADAP PENYAKIT BERCAK DAUN HITAM PADA KACANG TANAH
A field evaluation was conducted to study the genotypic correlation between yield potentials and resistance level to the late leafspot of peanut. The experiment was carried out at Muara experimental-field from October 1994 to January 1995 using 100 genotypes with natural late leafspot inoculation. The result showed that the resistance level to late leafspot, wish was quantitatively reflected by the fresh-leaves percentage has negative genotypic correlation with total and filled-pod numbe1: The negative genotypic correlation were also found between resistance level and the weight of total pod, filled pod, as kernel, although not significant
Proteomics-derived basal biomarker DNA-PKcs is associated with intrinsic subtype and long-term clinical outcomes in breast cancer
Precise biomarkers are needed to guide better diagnostics and therapeutics for basal-like breast cancer, for which DNA-dependent protein kinase catalytic subunit (DNA-PKcs) has been recently reported by the Clinical Proteomic Tumor Analysis Consortium as the most specific biomarker. We evaluated DNA-PKcs expression in clinically-annotated breast cancer tissue microarrays and correlated results with immune biomarkers (training set: n = 300; validation set: n = 2401). Following a pre-specified study design per REMARK criteria, we found that high expression of DNA-PKcs was significantly associated with stromal and CD8 + tumor infiltrating lymphocytes. Within the basal-like subtype, tumors with low DNA-PKcs and high tumor-infiltrating lymphocytes displayed the most favourable survival. DNA-PKcs expression by immunohistochemistry identified estrogen receptor-positive cases with a basal-like gene expression subtype. Non-silent mutations in PRKDC were significantly associated with poor outcomes. Integrating DNA-PKcs expression with validated immune biomarkers could guide patient selection for DNA-PKcs targeting strategies, DNA-damaging agents, and their combination with an immune-checkpoint blockade
KNOWLEDGE, ATTITUDE AND PRACTICE TOWARDS HIV/AIDS IN A RURAL KENYAN COMMUNITY
The aim of this research was to explore people’s knowledge, attitude, behaviour and practice towards HIV/AIDS and sexual activity in rural Kenya, where HIV is widespread. The study community was located in south-eastern Kenya, 50 km north of Mombassa, and had an estimated population of 1500. Subjects aged between 16 and 49 were recruited using a stratified cluster-sampling method and they completed self-administered questionnaires.Almost all respondents knew the word ‘HIV’. Around 50% knew of a person living with HIV. About 80% gave ‘death’ or ‘fear’ as words representing their image of AIDS. With regard to sexual activity, the distribution of answers to the question ‘how many partners have you ever had in your life’ was bimodal in males but had only one peak in females, indicating that some men have a large number of sexual partners in their lifetime. First sexual intercourse was at around 12?13 years for both sexes, but female teenagers were more sexually experienced than their male counterparts
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