1,026 research outputs found
Histone gene expression in Physarum polycephalum 2 Coupling of histone and DNA synthesis
AbstractThe addition of hydroxyurea to synchronously growing macroplasmodia of the slime mould, Physarum polycephalum, inhibited DNA synthesis by up to 90%. Histone protein synthesis was inhibited to the same extent. The synthesis of other nuclear proteins was not inhibited even though total RNA synthesis was inhibited. The results suggest that histone synthesis and DNA replication are tightly coupled
Transformation of serum-susceptible Escherichia coli O111 with p16Slux plasmid to allow for real-time monitoring of complement-based inactivation of bacterial growth in bovine milk
peer-reviewedComplement activity has only recently been characterized in raw bovine milk. However, the activity of this component of the innate immune system was found to diminish as milk was subjected to heat or partitioning during cream separation. Detection of complement in milk relies on a bactericidal assay. This assay exploits the specific growth susceptibility of Escherichia coli O111 to the presence of complement. Practical application of the assay was demonstrated when a reduction in complement activity was recorded in the case of pasteurized and reduced-fat milks. This presented an opportunity to improve the functionality of the bactericidal assay by incorporating bioluminescence capability into the target organism. Following some adaptation, the strain was transformed by correctly integrating the p16Slux plasmid. Growth properties of the transformed strain of E. coli O111 were unaffected by the modification. The efficacy of the strain adaptation was correlated using the LINEST function analysis [r=0.966; standard error of prediction (SEy)=0.957] bioluminescence with that of bactericidal assay total plate counts within the range of 7.5 to 9.2 log cfu/mL using a combination of raw and processed milk samples. Importantly, the transformed E. coli O111 p16Slux strain could be identified in milk and broth samples using bioluminescence measurement, thus enabling the bactericidal assay–viability test to be monitored in real time throughout incubation
High Pressure Processing of Dairy Foods
End of Project ReportThe term High Pressure Processing (HPP) is used to describe the technology whereby
products are exposed to very high pressures in the region of 50 - 800 MPa (500 - 8000
Atmospheres). The potential application of HPP in the food industry has gained popularity
in recent years, due to developments in the construction of HPP equipment which makes
the technology more affordable. Applying HPP to food products results in modifications to
interactions between individual components, rates of enzymatic reactions and inactivation
of micro-organisms.
The first commercial HPP products appeared on the market in 1991 in Japan, where HPP
is now being used commercially for products such as jams, sauces, fruit juices, rice cakes
and desserts. The pioneering research into the application of HPP to milk dates back to the
end of the 19th century. Application of HPP to milk has been shown to modify its gel
forming characteristics as well as reducing its microbial load. HPP offers the potential to
induce similar effects to those generated by heat on milk protein.
Recent reports have also indicated that HPP could accelerate the ripening of cheese. Much
of the Irish cheese industry is based on the production of Cheddar cheese, the ripening time
for which can vary from 4 - 12 months or more, depending on grade. A substantial portion
of the cost associated with Cheddar manufacture is therefore attributed to storage under
controlled conditions during ripening. Thus, any technology which may accelerate the
ripening of Cheddar cheese while maintaining a balanced flavour and texture is of major
economic significance.
While food safety is a dominant concern, consumers are increasingly demanding foods that
maintain their natural appearance and flavour, while free of chemical preservatives. HPP
offers the food industry the possibility of achieving these twin goals as this technology can
lead to reduced microbial loads without detrimentally effecting the nutritional or sensory
qualities of the product.
The development of food ingredients with novel functional properties offers the dairy
industry an opportunity to revitalise existing markets and develop new ones. HPP can lead
to modifications in the structure of milk components, in particular protein, which may
provide interesting possibilities for the development of high value nutritional and functional
ingredients.
Hence these projects set out to investigate the potential of HPP in the dairy industry and
to identify products and processes to which it could be applied.Department of Agriculture, Food and the Marin
Ballistic electron transport through magnetic domain walls
Electron transport limited by the rotating exchange-potential of domain walls
is calculated in the ballistic limit for the itinerant ferromagnets Fe, Co, and
Ni. When realistic band structures are used, the domain wall magnetoresistance
is enhanced by orders of magnitude compared to the results for previously
studied two-band models. Increasing the pitch of a domain wall by confinement
in a nano-structured point contact is predicted to give rise to a strongly
enhanced magnetoresistance.Comment: 4 pages, 2 figures; to appear in PRB as a brief repor
Modeling the influence of snow cover on low Arctic net ecosystem exchange
The Arctic net ecosystem exchange (NEE) of CO2 between the land surface and the atmosphere is influenced by the timing of snow onset and melt. The objective of this study was to examine whether uncertainty in model estimates of NEE could be reduced by representing the influence of snow on NEE using remote sensing observations of snow cover area (SCA). Observations of NEE and time-lapse images of SCA were collected over four locations at a low Arctic site (Daring Lake, NWT) in May-June 2010. Analysis of these observations indicated that SCA influences NEE, and that good agreement exists between SCA derived from time-lapse images, Landsat and MODIS. MODIS SCA was therefore incorporated into the vegetation photosynthesis respiration model (VPRM). VPRM was calibrated using observations collected in 2005 at Daring Lake. Estimates of NEE were then generated over Daring Lake and Ivotuk, Alaska (2004-2007) using VPRM formulations with and without explicit representations of the influence of SCA on respiration and/or photosynthesis. Model performance was assessed by comparing VPRM output against unfilled eddy covariance observations from Daring Lake and Ivotuk (2004-2007). The uncertainty in VPRM estimates of NEE was reduced when respiration was estimated as a function of air temperature when SCA ≤ 50% and as a function of soil temperature when SCA > 50%
The Role of Burn Centers in the Treatment of Necrotizing Soft-Tissue Infections:A Nationwide Dutch Study
Patients with extensive and complex wounds due to Necrotizing Soft-Tissue Infections (NSTI) may be referred to a burn center. This study describes the characteristics, outcomes, as well as diagnostic challenges of these patients. Patients admitted to three hospitals with a burn center for the treatment of NSTI in a 5-year period were included. Eighty patients (median age 54 years, 60% male) were identified, of whom 30 (38%) were referred by other centers, usually after survival of the initial septic phase. Those referred from other centers, compared to those primarily admitted to the study hospitals, were more likely to have group A streptococcal involvement (62% vs 35%, p = .02), larger wounds (median 7% vs 2% total body surface area, p < .001), and a longer length of stay (median 49 vs 22 days, p < .001). Despite a high incidence of septic shock (50%), the mortality rate was low (12%) for those primarily admitted. Approximately half (53%) of the patients were initially misdiagnosed upon presentation, which was associated with delay to first surgery (16 hours vs 4 hours, p < .001). Those initially misdiagnosed had more (severe) comorbidities, and less frequently reported pain or blue livid discoloration of the skin. This study underlines the burn centers' function as referral centers for extensively affected patients with NSTI. Besides the unique wound and reconstructive expertise, the low mortality rate indicates these centers provide adequate acute care as well. A major remaining challenge remains recognition of the disease upon presentation. Future studies in which factors associated with misdiagnosis are explored are needed.</p
Assessing the probability of introduction and transmission of lumpy skin disease virus within the United Kingdom
Several emerging exotic diseases are currently oscillating on the eastern borders of the European Union (EU) including the bovine pathogen Lumpy skin disease virus (LSDV). Given the recent transboundary spread of LSDV into the EU, assessing the probability of further expansion is an important part of EU surveillance and can inform policy regarding risk mitigation priorities. This qualitative assessment focuses on the probability of introduction and onward transmission of LSDV into the United Kingdom (UK) for the time period June 2017 to June 2018. Overall the probability of introduction was considered, at most, to be very low. The probability of onward transmission was considered highest for vector mediated routes either via contact of an infected vector with susceptible cattle or contact of a competent native vector with an infected cattle. Factors with high uncertainty were identified to emphasise their impact on the assessment conclusions and for future research requirements. Medium to high uncertainty surrounds the probability of introduction to the UK via several of the routes assessed, in particular, the species of vectors involved and the illegal/legal import of meat and milk products; all estimates made consequential to these probabilities are therefore underpinned by high uncertainty. Whilst the assessment was UK centric the knowledge gaps are relevant to the probability of introduction and spread of LSDV in any geographical region. The value of estimating uncertainty lies in the identification of research required to make conclusions more robust
Inclusive electron scattering in a relativistic Green function approach
A relativistic Green function approach to the inclusive quasielastic (e,e')
scattering is presented. The single particle Green function is expanded in
terms of the eigenfunctions of the nonhermitian optical potential. This allows
one to treat final state interactions consistently in the inclusive and in the
exclusive reactions. Numerical results for the response functions and the cross
sections for different target nuclei and in a wide range of kinematics are
presented and discussed in comparison with experimental data.Comment: 12 pages, 7 figures, REVTeX
Absence seizures as resetting mechanisms of brain dynamics
To understand the increase in age-related incidence and frequency of absence seizures in the rat brain, we investigated the effect of these seizures on brain dynamics. This paper puts forward the hypothesis that age-related differences in the expression of absence seizures are associated with the ability of the seizures to reset brain dynamics
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