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Subcutaneous adipose tissue (scAT) and peripheral blood mononuclear cells (PBMCs) play a significant role in obesity-associated systemic low-grade inflammation. High-fat diet (HFD) is known to induce inflammatory changes in both scAT and PBMCs. However, the time course of the effect of HFD on these systems is still unknown. The aim of the current study was to determine the time course of the effect of high fat diet (HFD) on PBMCs and scAT. New Zealand white rabbits were fed HFD for 5 or 10 weeks (i.e., HFD-5 and HFD-10), or regular chow (i.e., CNT-5 and CNT-10). Thereafter, metabolic and inflammatory parameters of PBMCs and scAT were quantitated. HFD induced hyperfattyacidemia in HFD-5 and HFD-10 groups, with the development of insulin resistance (IR) in HFD-10, while no changes were observed in scAT lipid metabolism and inflammatory status. HFD activated the inflammatory pathways in PBMCs of HFD-5 group, and induced modified autophagy in that of HFD-10. The rate of fat oxidation in PBMCs was directly associated with the expression of inflammatory markers; and tended to inversely associate with autophagosome formation markers in PBMCs. HFD affected systemic substrate metabolism, and the metabolic, inflammatory, and autophagy pathways in PBMCs in the absence of metabolic and inflammatory changes in scAT. Dietary approaches or interventions to avert HFD-induced changes in PBMCs could be essential in prevention of metabolic and inflammatory complications of obesity, and promote healthier living.
In the UK, the pig industry is leading the way in the adoption of welfare outcome measures as part of their farm assurance scheme. The welfare outcome assessment (WOA), known as Real Welfare, is conducted by the farmers’ own veterinary surgeon. For the first time, this has allowed the pig industry to evaluate welfare by directly assessing the animal itself and to document the welfare of the UK pig industry as a whole. Farmer perspectives of the addition of a welfare outcome assessment to their farm assurance scheme have yet to be explored. Here, we investigate how the introduction of the Real Welfare protocol has been perceived by the farmers involved, what value it has (if any), whether any practical changes on farm have been a direct consequence of Real Welfare and ultimately whether they consider that the welfare of their pigs has been improved by the introduction of the Real Welfare protocol. Semi-structured interviews with 15 English pig farmers were conducted to explore their perceptions and experiences of the Real Welfare process. Our findings fall into three key areas: the lived experience of Real Welfare, on-farm changes resulting from Real Welfare and suggested improvements to the Real Welfare process as it currently stands. In all the three areas, the value farmers placed on the addition of WOA appeared to reflect their veterinary surgeon’s attitude towards the Real Welfare protocol. If the vet was engaged in the process and actively included the farmer, for example through discussion of their findings, the farmers interviewed had a greater appreciation of the benefits of Real Welfare themselves. It is recommended that future similar schemes should work with veterinary surgeons to ensure their understanding and engagement with the process, as well as identifying and promoting how the scheme will practically benefit individual farmers rather than assuming that they will be motivated to engage for the good of the industry alone. Retailers should be encouraged to use Real Welfare as a marketing tool for pig products to enhance the perceived commercial value of this protocol to farmers.
All sectors of livestock production are in the process of shifting from small populations on many farms to large populations on fewer farms. A concurrent shift has occurred in the number of livestock moved across political boundaries. The unintended consequence of these changes has been the appearance of multifactorial diseases that are resistant to traditional methods of prevention and control. The need to understand complex animal health conditions mandates a shift toward the collection of longitudinal animal health data. Historically, collection of such data has frustrated and challenged animal health specialists. A promising trend in the evolution toward more efficient and effective livestock disease surveillance is the increased use of aggregate samples, e.g. bulk tank milk and oral fluid specimens. These sample types provide the means to monitor disease, estimate herd prevalence, and evaluate spatiotemporal trends in disease distribution. Thus, this article provides an overview of the use of bulk tank milk and pen-based oral fluids in the surveillance of livestock populations for infectious diseases.
The use of underground geological repositories, such as in radioactive waste disposal (RWD) and in carbon capture (widely known as Carbon Capture and Storage; CCS), constitutes a key environmental priority for the 21st century. Based on the identification of key scientific questions relating to the geophysics, geochemistry and geobiology of geodisposal of wastes, this paper describes the possibility of technology transfer from high-technology areas of the space exploration sector, including astrobiology, planetary sciences, astronomy, and also particle and nuclear physics, into geodisposal. Synergies exist between high technology used in the space sector and in the characterization of underground environments such as repositories, because of common objectives with respect to instrument miniaturization, low power requirements, durability under extreme conditions (in temperature and mechanical loads) and operation in remote or otherwise difficult to access environments.
Lameness in dairy cows is an important welfare issue. As part of a welfare assessment, herd level lameness prevalence can be estimated from scoring a sample of animals, where higher levels of accuracy are associated with larger sample sizes. As the financial cost is related to the number of cows sampled, smaller samples are preferred. Sequential sampling schemes have been used for informing decision making in clinical trials. Sequential sampling involves taking samples in stages, where sampling can stop early depending on the estimated lameness prevalence. When welfare assessment is used for a pass/fail decision, a similar approach could be applied to reduce the overall sample size. The sampling schemes proposed here apply the principles of sequential sampling within a diagnostic testing framework. This study develops three sequential sampling schemes of increasing complexity to classify 80 fully assessed UK dairy farms, each with known lameness prevalence. Using the Welfare Quality herd-size-based sampling scheme, the first ‘basic’ scheme involves two sampling events. At the first sampling event half the Welfare Quality sample size is drawn, and then depending on the outcome, sampling either stops or is continued and the same number of animals is sampled again. In the second ‘cautious’ scheme, an adaptation is made to ensure that correctly classifying a farm as ‘bad’ is done with greater certainty. The third scheme is the only scheme to go beyond lameness as a binary measure and investigates the potential for increasing accuracy by incorporating the number of severely lame cows into the decision. The three schemes are evaluated with respect to accuracy and average sample size by running 100 000 simulations for each scheme, and a comparison is made with the fixed size Welfare Quality herd-size-based sampling scheme. All three schemes performed almost as well as the fixed size scheme but with much smaller average sample sizes. For the third scheme, an overall association between lameness prevalence and the proportion of lame cows that were severely lame on a farm was found. However, as this association was found to not be consistent across all farms, the sampling scheme did not prove to be as useful as expected. The preferred scheme was therefore the ‘cautious’ scheme for which a sampling protocol has also been developed.
The Welfare Quality® protocols provide a multidimensional assessment of welfare, which is lengthy, and hence limited in terms of practicality. The aim of this study was to investigate potential ‘iceberg indicators’ which could reliably predict the overall classification as a means of reducing the length of time for an assessment and so increase the feasibility of the Welfare Quality® protocol as a multidimensional assessment of welfare. Full Welfare Quality® assessments were carried out on 92 dairy farms in England and Wales. The farms were all classified as Acceptable or Enhanced. Logistic regression models with cross validation were used to compare model fit for the overall classification on farms. ‘Absence of prolonged thirst’, on its own, was found to correctly classify farms 88% of the time. More generally, the inclusion of more measures in the models was not associated with greater predictive ability for the overall classification. Absence of prolonged thirst could thus, in theory, be considered to be an iceberg indicator for the Welfare Quality® protocol, and could reduce the length of time for a farm assessment to 15 min. Previous work has shown that the parameters within the Welfare Quality® protocol are important and relevant for welfare assessment. However, it is argued that the credibility of the published aggregation system is compromised by the finding that one resource measure (Absence of prolonged thirst) is a major driver for the overall classification. It is therefore suggested that the prominence of Absence of prolonged thirst in this role may be better understood as an unintended consequence of the published measure aggregation system rather than as reflecting a realistic iceberg indicator.
Pores in archaeological ceramics can form in a number of different ways, and reflect both deliberate choices and uncontrollable factors. Characterizing porosity by digital image analysis of thin sections holds a number of advantages as well as limitations. We present the results of experiments aimed at improving this method, focusing on high-resolution scans of entire thin sections. We examine the reproducibility of pore measurements by petrographic image analysis of ceramic thin sections using laboratory-prepared specimens of clay mixed with sand of known amount and size. We outline protocols for measuring Total Optical Porosity, using the Image-Pro Premier software package. We also briefly discuss use of pore size and pore shape (aspect ratio and roundness) in characterizing archaeological ceramics. While discerning reasons for observed amounts, sizes, and shapes of pores is an extremely complex problem, the quantitative analysis of ceramic porosity is one tool for characterizing a ware and comparing a product to others. The methods outlined here are applied to a case study comparing historic bricks from the Read House in New Castle, Delaware; the porosity studies indicate that different construction campaigns used bricks from different sources.
Non-destructive investigation, chemically fingerprinting, and authentication of ceramic cultural artifacts is a challenging analytical problem. Electron paramagnetic resonance (EPR) spectroscopy is capable of distinguishing between clays based on the paramagnetic metals present, and firing temperature (TF) based on the complexes of these metals formed at different TF values. Unfortunately, the 9 GHz frequency of conventional X-band EPR restricts sample size to a few mm and limits its applicability to small fragments. Low frequency EPR (LFEPR) is based on an EPR spectrometer operating at a few hundred MHz. LFEPR can utilize larger samples on the order of a few cm, but has a lower sensitivity due to the smaller Boltzmann ratio. Additionally, LFEPR may not be capable of detecting a spectral transition if the LFEPR operating frequency is less then the zero-field splitting of the paramagnetic metal complex. We utilized an LFEPR operating at 300 MHz which scans the applied magnetic field between the local Earth’s magnetic field and 26 mT to determine the feasibility of detecting EPR signals from clays, pigments, and glazes. Various clay samples were studied at 100 < TF < 1200 °C. Spectral differences were seen as a function of both clay type and TF. Differences in the LFEPR spectra of Han, Egyptian, and Ultramarine blue support the ability to distinguish among pigments. Paramagnetic impurities in glass may allow distinction between glaze spectra. We have also explored the utility of LFESR by the use of a radio frequency surface coil rather than an enclosed resonator. Although the active volume of the surface coil is ∼1 cm3, objects as large as 20 cm in diameter might be easily characterized with our spectrometer.
As scientists are able to understand and manipulate ever smaller scales of matter, research in the fields of biotechnology and nanotechnology has converged to enable such radical innovations as lab-on-a-chip devices, targeted drug delivery, and other forms of minimally invasive therapy and diagnostics. This paper provides a descriptive overview of the emerging bio-nano sector, identifying what types of firms are entering, from what knowledge base, where they are located, and their strategic choices in terms of technological diversity and R&D strategy. The firms engaged in bio-nano research and development span the range from start-up firm to multinational pharmaceutical, biotech, chemical, and electronics firms: two thirds of bio-nano firms are relatively young and relatively small. The United States dominates this sector, with more than half of all bio-nano firms located in the USA. Even within this sector which epitomizes the convergence of technology, there is a broad range of technological diversity, with the most diverse firms overall coming from a base in electronics, the most diverse start-up firms coming from a base in nanomaterials, and the most narrowly focused firms coming from a biotechnology/pharmaceutical base. We find that hybridization has been the dominant knowledge diversity strategy, with 93% of the bio-nano firms with nano-patents holding multiclass patents.
A new technique for direct determination of the density of electronic states (DOS) in disordered semiconductors is described. It involves Laplace transformation of transient photocurrent data I(t) followed by the numerical solution of the system of linear algebraic equations obtained from the Fredholm integral of the first kind, for a DOS represented by a series of discrete levels. No approximations are used in the solution, and no prior assumptions as to the form of the DOS are made. The fidelity of this method is assessed and compared with existing techniques by application to computer-simulated I(t) data generated from single-level and continuous DOS profiles, and to experimental data.
The effects of random noise on density of states determination from transient photocurrent data are examined by superimposing noise levels similar to those found experimentally (1% to 20%) on computer-simulated current-time data. Mathematically approximate methods based on Fourier and Laplace transformations are found to operate effectively at noise levels of up to 20%. Mathematically exact methods offer higher resolution, but this is compromised by greater susceptibility to noise. A Tikhonov regularisation method yields both high resolution and good noise tolerance.
We examine different approaches to the analysis of noise in amorphous hydrogenated silicon associated with trapping and generation – recombination processes, which appear to predict very different noise spectra. In one approach the broad noise spectrum observed is assumed to be composed of a distribution of Lorentzian noise spectra, each associated with traps at a given energy depth, with appropriate weighting according to the energy distribution of characteristic time constants. This latter weighting is taken to mirror the energy distribution of states in the gap. This represents a linear superposition of the (weighted) contribution from individual trapping levels, each with its own characteristic time constant. This approach thus assumes that each trap level is an independent source of fluctuation in free carrier number, unaffected by the presence of other traps in the material. At first sight this assertion seems plausible, since in the multi-trapping situation envisaged, cross-correlation effects must be very small. However, the presence of several groups of traps, or, in the limit, a continuum, results in a distribution of characteristic time constants, which is not a simple linear superposition of the time constants for each level. Thus the assertion that a flat density of states, or a region which is flat, such as the top of a broadened level, results in a region of 1/f slope in the noise spectrum, may not be valid. We present an alternative model in which the distribution of time constants is appropriately incorporated, and compare the predictions of this model with the ‘superposition’ approach, using computed noise spectra.
Three Laplace transform methods for recovering the density of electronic states from transient photocurrent data are evaluated through a study of light-induced defect creation in PECVD a-Si:H films. A mathematically approximate method is shown to be sufficient to resolve the deep defects, whose density is estimated to increase by a factor of five from the annealed state after 3 hours' exposure to simulated AM1 illumination. An exact method, and a method employing Tikhonov regularisation, are found to give very similar results, provided the current-time data are smoothed beforehand in the former case. The increased resolution available is, however, unnecessary here, and these methods are shown to be more suited to the study of discrete levels or narrow distributions.
We have investigated the electronic properties of films of arsenic triselenide into which the transition metal nickel has been introduced by a co-sputtering technique. Measurement of d.c. conductivity, thermopower, optical absorption and photomobility have been performed to characterise the material. These measurements give new information concerning the influence of nickel on the optical gap, the position of the Fermi-level, and other aspects of transport in As2 Se3. In the most heavily doped sample the d.c. conductivity is increased by 11 orders of magnitude and the position of the Fermi-level is shifted by ΔEF∼0.6 eV. The results are explained in terms of a model in which an acceptor level is introduced into the valence band tail of a background density of states (DOS) obtained earlier for the undoped material. In contrast to the suggestion by previous workers that the incorporation of high concentrations of nickel can produce a transition to n-type conduction, we argue that the Fermi-level remains in the valence band tail and that hopping conduction of carriers close the Fermi-level yields a negative sign in thermopower.
An account is given for the conditions under which the collection efficiency in hydrogen ated amorphous silicon pin-diodes increases to values larger than 100 %. By specific bias illumination through the p-side bias generated photocarriers are collected under certain probe beam conditions of the collection efficiency measurement, leading to apparent large collection efficiencies. By numerical modelling we investigated the influence of the diode thickness, bias photon flux and probe absorption coefficient as well as applied voltage for possible sensor applications which may utilise this optical amplifying principle. The alternative with bias light through the n-side and probe light through the p-side is also explored. Collection efficiency values determined by the photogating of bias generated holes become only slightly larger than 100 % in contrast to the electron case where values in excess of 3000 % are presented.
We report measured electron and hole gating in thick a-Si:H (3.5 μm) p-i-n diodes under reverse bias conditions. Previous publications have shown very high collection efficiency values for electron gating (p-side bias, n-side probe) of up to 50 (i.e. 5000%) for measured and simulated data and predictions of up to 400 (i.e. 40000%) from simulations. Reversing the usual sides of illumination for (electron) gating a situation can be created where, by n-side bias and p-side probe illumination, holes can be gated to travel through the sample to be collected at the contact. Even though the holes have much lower mobility, by this process we can still obtain collection efficiencies greater than unity. This measurement is more difficult because of unwanted illumination by stray bias beam photons on the more sensitive p-side, caused by reflections within the apparatus. Simulation of this situation corroborates qualitatively the measured data. A wide ranging study of the gating phenomenon in relation to different incident wavelengths and photon fluxes for bias and probe beam is reported. We present comparisons of electron and hole gating by measurement and simulation and explain the phenomenon for both electron and hole gating in terms of field changes near to the incident bias interface.