Effects of organic and ‘low input’ production methods on food quality and safety

The intensification of agricultural production in the last century has resulted in a significant loss of biodiversity, environmental problems and associated societal costs. The use of shorter rotations or monocropping and high levels of mineral fertilisers, pesticides and crop growth regulators may also have had negative impacts on food quality and safety. To reverse the negative environmental and biodiversity impacts of agricultural intensification, a range of different ‘low input’ farming systems have been developed and are now supported by EU and government support schemes. A range of recent reviews concluded that switching to low input, integrated or organic farming practices results in significant environmental benefits and increased biodiversity in agro-ecosystems. Some recent studies also reported higher levels of nutritionally desirable compounds (e.g. vitamins, antioxidants, mineral nutrients) in foods from organic and ‘low input’ production systems compared to food from conventional systems. The increasing demand and current price premiums achieved by foods from low input and especially organic production systems were shown to be closely linked to consumer perceptions about nutritional and health benefits of such foods. However, there are other studies reporting no significant differences in composition between low input and conventional foods, or inconsistent results. There is currently a lack of (a) factorial studies, which allow the effect of individual production system components (e.g. rotation design, fertility management, crop health management, variety choice) on food composition to be assessed and (b) dietary intervention or cohort studies which compare the effect of consuming foods from different production systems on animal and/or human health. It is therefore currently not possible to draw overall conclusions about the effect of low input production on food quality and safety. This paper will (a) describe the range of organic and other ‘low input’ standards, certification and support systems currently used, (b) summarise the currently available information on effects of organic and other low input crop production systems on the environment, biodiversity and food quality, and (c) describe the methodologies and results from subproject 2 of the EU-funded Integrated project QualityLowInputFood. This project focused on improving our knowledge about the effect of organic and low input crop and livestock production systems on food quality and safety parameters

On the non-normal two-point Padé table

AbstractThe M-table for two power series expansions, one about the origin and the other about infinity, is generalized to the non-normal case. It is shown that equal entries appear in square blocks, quadrants or half planes. In addition, the continued fractions whose convergents are diagonal or horizontal sequences are constructed. The results are based on a transformation that reduces the study of the two-point table to that of the Padé table

Motivation as a predictor of outcomes in school-based humanistic counselling

Recent years have seen a growth in the provision of counselling within UK secondary schools, and research indicates that it is associated with significant reductions in psychological distress. However, little is known about the moderators and mediators of positive therapeutic benefit. In the field of adult mental health, motivation has been found to be one of the strongest predictors of therapeutic outcomes, and it was hypothesised that this may also be a predictor of outcomes for young people in school-based counselling services. To assess the relationship between young people’s motivation for counselling and its effectiveness within a secondary school setting. Eighty-one young people (12 - 17 years old) who attended school-based humanistic counselling services in Scotland. Clients completed a measure of motivation for counselling at the commencement of their therapeutic work and a measure of psychological wellbeing at the commencement and termination of counselling. Motivation for counselling was not found to be significantly related to outcomes. The results indicate that the association between motivation and outcomes may be weaker in young people as compared with adults. However, a number of design factors may also account for the non-significant findings: insufficient participants, marginal reliability of the motivation measure and social desirability effects

On the use of a corresponding sequence algorithm for δ-fractions

AbstractThis paper discusses an algorithm for generating a new type of continued fraction, a δ-fraction, from a given power series. The δ-fraction corresponds to the given power series at z = 0. Included are convergence results and truncation error bounds

A model for single electron decays from a strongly isolated quantum dot

Recent measurements of electron escape from a non-equilibrium charged quantum dot are interpreted within a 2D separable model. The confining potential is derived from 3D self-consistent Poisson-Thomas-Fermi calculations. It is found that the sequence of decay lifetimes provides a sensitive test of the confining potential and its dependence on electron occupation.Comment: 9 pages, 10 figure

Sedation for fibre optic bronchoscopy

AbstractMost current sedative regimens for fibre optic bronchoscopy use an opioid, a benzodiazepine or a combination of both. This study compares midazolam (M) (a benzodiazepine), alfentanil (A) (an opioid) and a combination of both drugs (M + A).One hundred and three patients were randomized in double-blind manner into groups M(35), A(33) and M + A(35). The number of coughs, number of additional aliquots of lignocaine and duration of the procedures were recorded along with oxygen desaturation. The patient's level of discomfort was assessed by patient and bronchoscopist and expressed as a visual analogue score.There were significantly fewer coughs per minute in Group A compared with Group M (P=0·0053), and significantly less lignocaine was required in Group A (P=0·005) and in Groups M + A (P<0·002) compared with Group M. There was no significant difference in the assessment of discomfort between the groups. There was a trend for Group M + A to desaturate more than the other two with a significant difference between desaturation in Group M + A and Group A (P=0·033).Alfentanil is a more effective anti-tussive agent than midazolam for outpatient fibre optic bronchoscopy. The combination of alfentanil and midazolam does not provide any better anti-tussive effect and may have the risk of a greater degree of desaturation secondary to increased sedation

Association of FCGR3A and FCGR3B haplotypes with rheumatoid arthritis and primary Sjögren's syndrome [POSTER PRESENTATION]

Background Rheumatoid arthritis (RA) is an autoimmune disease that is thought to arise from a complex interaction between multiple genetic factors and environmental triggers. We have previously demonstrated an association between a Fc gamma receptor (FcγR) haplotype and RA in a cross-sectional cohort of RA patients. We have sought to confirm this association in an inception cohort of RA patients and matched controls. We also extended our study to investigate a second autoanti-body associated rheumatic disease, primary Sjögren's syndrome (PSS). Methods The FCGR3A-158F/V and FCGR3B-NA1/NA2 functional polymorphisms were examined for association in an inception cohort of RA patients (n = 448), and a well-characterised PSS cohort (n = 83) from the United Kingdom. Pairwise disequilibrium coefficients (D') were calculated in 267 Blood Service healthy controls. The EHPlus program was used to estimate haplotype frequencies for patients and controls and to determine whether significant linkage disequilibrium was present. A likelihood ratio test is performed to test for differences between the haplotype frequencies in cases and controls. A permutation procedure implemented in this program enabled 1000 permutations to be performed on all haplotype associations to assess significance. Results There was significant linkage disequilibrium between FCGR3A and FCGR3B (D' = -0.445, P = 0.001). There was no significant difference in the FCGR3A or FCGR3B allele or genotype frequencies in the RA or PSS patients compared with controls. However, there was a significant difference in the FCGR3A-FCGR3B haplotype distributions with increased homozygosity for the FCGR3A-FCGR3B 158V-NA2 haplotype in both our inception RA cohort (odds ratio = 2.15, 95% confidence interval = 1.1–4.2 P = 0.027) and PSS (odds ratio = 2.83, 95% confidence interval = 1.0–8.2, P = 0.047) compared with controls. The reference group for these analyses comprised individuals who did not possess a copy of the FCGR3A-FCGR3B 158V-NA2 haplotype. Conclusions We have confirmed our original findings of association between the FCGR3A-FCGR3B 158V-NA2 haplotype and RA in a new inception cohort of RA patients. This suggests that there may be an RA-susceptibility gene at this locus. The significant increased frequency of an identical haplotype in PSS suggests the FcγR genetic locus may contribute to the pathogenesis of diverse autoantibody-mediated rheumatic diseases

Chaos and Preheating

We show evidence for a relationship between chaos and parametric resonance both in a classical system and in the semiclassical process of particle creation. We apply our considerations in a toy model for preheating after inflation.Comment: 7 pages, 9 figures; uses epsfig and revtex v3.1. Matches version accepted for publication in Phys. Rev.

Study of the dependence of 198Au half-life on source geometry

We report the results of an experiment to determine whether the half-life of \Au{198} depends on the shape of the source. This study was motivated by recent suggestions that nuclear decay rates may be affected by solar activity, perhaps arising from solar neutrinos. If this were the case then the $\beta$-decay rates, or half-lives, of a thin foil sample and a spherical sample of gold of the same mass and activity could be different. We find for \Au{198}, $(T_{1/2})_{\rm foil}/(T_{1/2})_{\rm sphere} = 0.999 \pm 0.002$, where $T_{1/2}$ is the mean half-life. The maximum neutrino flux at the sample in our experiments was several times greater than the flux of solar neutrinos at the surface of the Earth. We show that this increase in flux leads to a significant improvement in the limits that can be inferred on a possible solar contribution to nuclear decays.Comment: 5 pages, 1 figur

Thomas-Fermi-Poisson theory of screening for latterally confined and unconfined two-dimensional electron systems in strong magnetic fields

We examine within the self-consistent Thomas-Fermi-Poisson approach the low-temperature screening properties of a two-dimensional electron gas (2DEG) subjected to strong perpendicular magnetic fields. Numerical results for the unconfined 2DEG are compared with those for a simplified Hall bar geometry realized by two different confinement models. It is shown that in the strongly non-linear screening limit of zero temperature the total variation of the screened potential is related by simple analytical expressions to the amplitude of an applied harmonic modulation potential and to the strength of the magnetic field.Comment: 12 pages, 12 figure