104 research outputs found

    Metabolic rate throughout the annual cycle reveals the demands of an Arctic existence in Great Cormorants

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    Aquatic endotherms living in polar regions are faced with a multitude of challenges, including low air and water temperatures and low illumination, especially in winter. Like other endotherms from cold environments, Great Cormorants (Phalacrocorax carbo) living in Arctic waters were hypothesized to respond to these challenges through combination of high daily rate of energy expenditure (DEE) and high food requirements, which are met by a high rate of catch per unit effort (CPUE). CPUE has previously been shown in Great Cormorants to be the highest of any diving bird. In the present study, we tested this hypothesis by making the first measurements of DEE and foraging activity of Arctic-dwelling Great Cormorants throughout the annual cycle. We demonstrate that, in fact, Great Cormorants have surprisingly low rates of DEE. This low DEE is attributed primarily to very low levels of foraging activity, particularly during winter, when the cormorants spent only 2% of their day submerged. Such a low level of foraging activity can only be sustained through consistently high foraging performance. We demonstrate that Great Cormorants have one of the highest recorded CPUEs for a diving predator; 18.6 g per minute submerged (95% prediction interval 13.0-24.2 g/min) during winter. Temporal variation in CPUE was investigated, and highest CPUE was associated with long days and shallow diving depths. The effect of day length is attributed to seasonal variation in prey abundance. Shallow diving leads to high CPUE because less time is spent swimming between the surface and the benthic zone where foraging occurs. Our study demonstrates the importance of obtaining accurate measurements of physiology and behavior from free-living animals when attempting to understand their ecology

    The rationale of opportunistic bilateral salpingectomies (OBS) during benign gynaecological and obstetric surgery : a consensus text of the Flemish Society of Obstetrics and Gynaecology (VVOG)

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    Ovarian cancer (OC), is a disease difficult to diagnose in an early stage implicating a poor prognosis. The 5-year overall survival in Belgium has not changed in the last 18 years and remains 44 %. There is no effective screening method (secondary prevention) to detect ovarian cancer at an early stage. Primary prevention of ovarian cancer came in the picture through the paradigm shift that the fallopian tube is often the origin of ovarian cancer and not the ovary itself. Opportunistic bilateral salpingectomy (OBS) during benign gynaecological and obstetric surgery might have the potential to reduce the risk of ovarian cancer by as much as 65 %. Bilateral risk-reducing salpingectomy during a benign procedure is feasible, safe, appears to have no impact on the ovarian function and seems to be cost effective. The key question is whether we should wait for a RCT or implement OBS directly in our daily practice. Guidelines regarding OBS within our societies are therefore urgently needed. Our recommendation is to inform all women without a child wish, undergoing a benign gynaecological or obstetrical surgical procedure about the pro’s and the con’s of OBS and advise a bilateral salpingectomy. Furthermore, there is an urgent need for a prospective registry of OBS. The present article is the consensus text of the Flemish Society of Obstetrics and Gynaecology (VVOG) regarding OBS

    Immunological analysis of a Lactococcus lactis-based DNA vaccine expressing HIV gp120

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    For reasons of efficiency Escherichia coli is used today as the microbial factory for production of plasmid DNA vaccines. To avoid hazardous antibiotic resistance genes and endotoxins from plasmid systems used nowadays, we have developed a system based on the food-grade Lactococcus lactis and a plasmid without antibiotic resistance genes. We compared the L. lactis system to a traditional one in E. coli using identical vaccine constructs encoding the gp120 of HIV-1. Transfection studies showed comparable gp120 expression levels using both vector systems. Intramuscular immunization of mice with L. lactis vectors developed comparable gp120 antibody titers as mice receiving E. coli vectors. In contrast, the induction of the cytolytic response was lower using the L. lactis vector. Inclusion of CpG motifs in the plasmids increased T-cell activation more when the E. coli rather than the L. lactis vector was used. This could be due to the different DNA content of the vector backbones. Interestingly, stimulation of splenocytes showed higher adjuvant effect of the L. lactis plasmid. The study suggests the developed L. lactis plasmid system as new alternative DNA vaccine system with improved safety features. The different immune inducing properties using similar gene expression units, but different vector backbones and production hosts give information of the adjuvant role of the silent plasmid backbone. The results also show that correlation between the in vitro adjuvanticity of plasmid DNA and its capacity to induce cellular and humoral immune responses in mice is not straight forward

    Fine Tuning of the Lactate and Diacetyl Production through Promoter Engineering in Lactococcus lactis

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    Lactococcus lactis is a well-studied bacterium widely used in dairy fermentation and capable of producing metabolites with organoleptic and nutritional characteristics. For fine tuning of the distribution of glycolytic flux at the pyruvate branch from lactate to diacetyl and balancing the production of the two metabolites under aerobic conditions, a constitutive promoter library was constructed by randomizing the promoter sequence of the H2O-forming NADH oxidase gene in L. lactis. The library consisted of 30 promoters covering a wide range of activities from 7,000 to 380,000 relative fluorescence units using a green fluorescent protein as reporter. Eleven typical promoters of the library were selected for the constitutive expression of the H2O-forming NADH oxidase gene in L. lactis, and the NADH oxidase activity increased from 9.43 to 58.17-fold of the wild-type strain in small steps of activity change under aerobic conditions. Meanwhile, the lactate yield decreased from 21.15±0.08 mM to 9.94±0.07 mM, and the corresponding diacetyl production increased from 1.07±0.03 mM to 4.16±0.06 mM with the intracellular NADH/NAD+ ratios varying from 0.711±0.005 to 0.383±0.003. The results indicated that the reduced pyruvate to lactate flux was rerouted to the diacetyl with an almost linear flux variation via altered NADH/NAD+ ratios. Therefore, we provided a novel strategy to precisely control the pyruvate distribution for fine tuning of the lactate and diacetyl production through promoter engineering in L. lactis. Interestingly, the increased H2O-forming NADH oxidase activity led to 76.95% lower H2O2 concentration in the recombinant strain than that of the wild-type strain after 24 h of aerated cultivation. The viable cells were significantly elevated by four orders of magnitude within 28 days of storage at 4°C, suggesting that the increased enzyme activity could eliminate H2O2 accumulation and prolong cell survival

    Does corporate reputation matter? Role of social media in consumer intention to purchase innovative food product

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    The exponential growth of the corporate reputation in food industry has resulted in innovations in every link of its supply chain. There have been studies that have characterized innovation in various industries from the perspective of technology, but far fewer in the area of corporate reputation, consumer perception, and intention towards innovations in food products. This research analyses the innovations in the food industry from the perspective of the consumer and provides a conceptual framework of food innovation stages. The study also investigates the relationship between corporate reputation and intention towards food innovation along with the other components of TPB model with an extension of social media engagement. The results from India and US samples confirm that social media engagement have a significant role to play in creating intention to purchase innovative food products. The study compares the US and Indian samples and identifies differences in subjective norms and perceived behavioural control

    Effecten van geluidhinder door militaire activiteiten op gedrag en ecologie van wadvogels

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