993 research outputs found

    Comparison of black soldier fly larvae pre-treatments and drying techniques on the microbial load and physico-chemical characteristics

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    Black soldier fly larvae (BSFL) are good candidates for upcycling wet organic residuals. Like other unprocessed raw animal products, BSFL require processing to prevent spoilage and degradation during storage and to facilitate their use as feed ingredients. In this study, hot-air drying and freeze-drying were examined as means to ensure long-term preservation. Pre-treatments of larvae, such as puncturing, blanching (40 s) and scalding (2, 4, 6 and 8 min) in boiling water reduced drying times, most likely by affecting the integrity of the wax-coated cuticle that protects the larvae against desiccation. Overall, the larvae dried two to six times faster using hot-air compared to freeze-drying, and larvae pre-treatments were proven to effectively improve drying efficacy. Pre-treating larvae in boiling water followed by a shorter drying time with hot air was effective at reducing primary and secondary oxidation as well as darkening/browning (colour lightness, L* value) compared to the untreated control (rawthawed) larvae. The larvae pre-treatments in boiling water also led to a significant reduction in microbial load (3.21 to 4.83 log) in the dry product compared to the control. BSFL powder, produced from grinding thawed larvae that were pre-treated for 4 min in boiling water before being dried in hot air (60 °C; 6 h), had a water activity below 0.4. This led to a relatively stable product with limited colour changes over a 30-day storage period. These processing treatments also resulted in a product with no detectable Salmonella and Escherichia coli counts ranging from 100 to 1000 cfu/g. Overall, the powdered BSFL product was deemed suitable to incorporate into pelleted feed under the current regulations in Canada

    Effects of killing methods on lipid oxidation, colour and microbial load of black soldier fly (Hermetia illucens) larvae

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    The projected global population growth by 2050 will require an increase in the production of high-quality food. Insects represent a promising alternative ingredient for feed with a lower environmental impact than conventional livestock such as poultry, swine and bovine species. In a context of commercial-scale production and considering the great diversity of insects, it is crucial to optimize the processing steps, including those used to kill insects. In addition to being able to maximize the nutritional and microbiological quality of the final product, insect killing methods should be rapid and effective. This project aims to optimize killing methods, i.e., blanching, desiccation, freezing (−20 °C; −40 °C; liquid nitrogen), high hydrostatic pressure, grinding and asphyxiation (CO2; N2; vacuum conditioning), and to evaluate their impact on the composition, lipid oxidation, colour and microbiological quality on the black soldier fly larvae. Blanching appears to be the most appropriate strategy since it is a rapid and effective killing method reducing larval moisture while minimizing lipid oxidation, microbial contamination and colour alteration. Ultimately, this work will help to establish a standardized protocol that meets the Canadian regulatory quality requirements for feed. Abstract : Black soldier fly (BSF) larvae represent a promising alternative ingredient for animal feed. Post-production processing can, however, affect their quality. This project aimed to optimize larval killing by comparing the effects on the nutritional and microbiological quality of 10 methods, i.e., blanching (B = 40 s), desiccation (D = 60 °C, 30 min), freezing (F20 = −20 °C, 1 h; F40 = −40 °C, 1 h; N = liquid nitrogen, 40 s), high hydrostatic pressure (HHP = 3 min, 600 MPa), grinding (G = 2 min) and asphyxiation (CO2 = 120 h; N2 = 144 h; vacuum conditioning, V = 120 h). Some methods affected the pH (B, asphyxiation), total moisture (B, asphyxiation and D) and ash contents (B, p < 0.001). The lipid content (asphyxiation) and their oxidation levels (B, asphyxiation and D) were also affected (p < 0.001). Killing methods altered the larvae colour during freeze-drying and in the final product. Blanching appears to be the most appropriate strategy since it minimizes lipid oxidation (primary = 4.6 ± 0.7 mg cumen hydroperoxide (CHP) equivalents/kg; secondary = 1.0 ± 0.1 mg malondialdehyde/kg), reduces microbial contamination and initiates dehydration (water content = 78.1 ± 1.0%). We propose herein, an optimized protocol to kill BSF that meet the Canadian regulatory requirements of the insect production and processing industry

    Knowledge, Attitudes, Practices and Beliefs about Medical Male Circumcision (MMC) among a Sample of Health Care Providers in Haiti

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    Background Haiti has the highest number of people living with HIV infection in the Caribbean/Latin America region. Medical male circumcision (MMC) has been recommended to help prevent the spread of HIV. We sought to assess knowledge, attitudes, practices and beliefs about MMC among a sample of health care providers in Haiti. Methods A convenience sample of 153 health care providers at the GHESKIO Centers in Haiti responded to an exploratory survey that collected information on several topics relevant to health providers about MMC. Descriptive statistics were calculated for the responses and multivariable logistic regression was conducted to determine opinions of health care providers about the best age to perform MMC on males. Bayesian network analysis and sensitivity analysis were done to identify the minimum level of change required to increase the acceptability of performing MMC at age less than 1 year. Results The sample consisted of medical doctors (31.0%), nurses (49.0%), and other health care professionals (20.0%). Approximately 76% showed willingness to offer MMC services if they received training. Seventy-six percent believed that their male patients would accept circumcision, and 59% believed infancy was the best age for MMC. More than 90% of participants said that MMC would reduce STIs. Physicians and nurses who were willing to offer MMC if provided with adequate training were 2.5 (1.15–5.71) times as likely to choose the best age to perform MMC as less than one year. Finally, if the joint probability of choosing “the best age to perform MMC” as one year or older and having the mistaken belief that MMC prevents HIV entirely is reduced by 63% then the probability of finding that performing MMC at less than one year acceptable to health care providers is increased by 35%. Conclusion Participants demonstrated high levels of knowledge and positive attitudes towards MMC. Although this study suggests that circumcision is acceptable among certain health providers in Haiti, studies with larger and more representative samples are needed to confirm this finding

    Laser Light Scattering, from an Advanced Technology Development Program to Experiments in a Reduced Gravity Environment

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    Recent advancements in laser light scattering hardware are described. These include intelligent single card correlators; active quench/active reset avalanche photodiodes; laser diodes; and fiber optics which were used by or developed for a NASA advanced technology development program. A space shuttle experiment which will employ aspects of these hardware developments is previewed

    Efeitos do tratamento com inibidor da rock durante o estágio de pós-aquecimento de oócitos bovinos vitrificados sobre desenvolvimento embrionário / Effects of treatment with rock inhibitor during the post-warming stage of vitrified bovine oocytes on embryo development

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    Diversas biotécnicas vem sendo utilizadas para a preservação de material genético e manutenção a medio e longo prazo de gametas e embrioes de elevado valor genético, contribuindo para o avanço das estratégias para produção pecuária. O processo de vitrificação de oocitos bovinos é uma delas, entretanto com aplicação ainda restrita, pois durante o processo  podem ocorrer varias crio injurias. Afim de reduzir os danos causados pelo congelamento de oócitos e melhorar as taxas de  clivagem e desenvolvimento embrionário obtidas no cultivo in vitro, utilizou-se a exposição a Y-27632, um inibidor seletivo de quinases de proteínas específicas associadas com Rho durante o estágio de pós-aquecimento.  Nosso estudo demonstrou que a utilização de Y-27632 em oocitos bovinos maturados e submetidos a vitrificação promoveu  taxas mais elevadas de sobrevivência bem como maior número de embriões atingindo o etágio de blastocisto.

    Geological interpretation of volcanism and segmentation of the Mariana back-arc spreading center between 12.7°N and 18.3°N

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    The relationships between tectonic processes, magmatism, and hydrothermal venting along ∼600 km of the slow-spreading Mariana back-arc between 12.7°N and 18.3°N reveal a number of similarities and differences compared to slow-spreading mid-ocean ridges. Analysis of the volcanic geomorphology and structure highlights the complexity of the back-arc spreading center. Here, ridge segmentation is controlled by large-scale basement structures that appear to predate back-arc rifting. These structures also control the orientation of the chains of cross-arc volcanoes that characterize this region. Segment-scale faulting is oriented perpendicular to the spreading direction, allowing precise spreading directions to be determined. Four morphologically distinct segment types are identified: dominantly magmatic segments (Type I); magmatic segments currently undergoing tectonic extension (Type II); dominantly tectonic segments (Type III); and tectonic segments currently undergoing magmatic extension (Type IV). Variations in axial morphology (including eruption styles, neovolcanic eruption volumes, and faulting) reflect magma supply, which is locally enhanced by cross-arc volcanism associated with N-S compression along the 16.5°N and 17.0°N segments. In contrast, cross-arc seismicity is associated with N-S extension and increased faulting along the 14.5°N segment, with structures that are interpreted to be oceanic core complexes—the first with high-resolution bathymetry described in an active back-arc basin. Hydrothermal venting associated with recent magmatism has been discovered along all segment types

    Engaging basic scientists in translational research: identifying opportunities, overcoming obstacles

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    This report is based on the Federation of American Societies for Experimental Biology’s symposium, “Engaging basic Scientists in Translational Research: Identifying Opportunities, Overcoming Obstacles,” held in Chevy Chase, MD, March 24–25, 2011. Meeting participants examined the benefits of engaging basic scientists in translational research, the challenges to their participation in translational research, and the roles that research institutions, funding organizations, professional societies, and scientific publishers can play to address these challenges

    Rare mutations in SQSTM1 modify susceptibility to frontotemporal lobar degeneration

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    Mutations in the gene coding for Sequestosome 1 (SQSTM1) have been genetically associated with amyotrophic lateral sclerosis (ALS) and Paget disease of bone. In the present study, we analyzed the SQSTM1 coding sequence for mutations in an extended cohort of 1,808 patients with frontotemporal lobar degeneration (FTLD), ascertained within the European Early-Onset Dementia consortium. As control dataset, we sequenced 1,625 European control individuals and analyzed whole-exome sequence data of 2,274 German individuals (total n = 3,899). Association of rare SQSTM1 mutations was calculated in a meta-analysis of 4,332 FTLD and 10,240 control alleles. We identified 25 coding variants in FTLD patients of which 10 have not been described. Fifteen mutations were absent in the control individuals (carrier frequency < 0.00026) whilst the others were rare in both patients and control individuals. When pooling all variants with a minor allele frequency < 0.01, an overall frequency of 3.2 % was calculated in patients. Rare variant association analysis between patients and controls showed no difference over the whole protein, but suggested that rare mutations clustering in the UBA domain of SQSTM1 may influence disease susceptibility by doubling the risk for FTLD (RR = 2.18 [95 % CI 1.24-3.85]; corrected p value = 0.042). Detailed histopathology demonstrated that mutations in SQSTM1 associate with widespread neuronal and glial phospho-TDP-43 pathology. With this study, we provide further evidence for a putative role of rare mutations in SQSTM1 in the genetic etiology of FTLD and showed that, comparable to other FTLD/ALS genes, SQSTM1 mutations are associated with TDP-43 pathology
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