Multistage and adaptive sampling protocols combined with near-infrared spectral sensors for automated monitoring of raw materials in bulk

A near-infrared (NIR) spectroscopy-based real-time monitoring system is proposed to sample and analyse agro-industrial raw materials transported in bulk in a single stage, easing and optimising the evaluation process of incoming lots at reception of agri-food plants. NIR analysis allows rapid and cost-effective analytical results to be obtained, and hence to rethink current sampling protocols. For this purpose, multistage and adaptive sampling designs were tested in this paper, which have been reported (in soil science and ecology) to be more flexible and efficient than conventional strategies to study patterns of clustering or patchiness, which can be the result of natural phenomena. The additional spatial information provided by NIR has also been exploited, using geostatistical analysis to model the spatial pattern of key analytical constituents in Processed Animal Proteins (PAPs). This study addresses the assessment of two kinds of quality/safety issues in PAP lots – moisture accumulation and cross-contamination. After a simulation study, qualitative and quantitative analyses were carried out to make a performance comparison between sampling designs. Results show that sampling densities below 10–15% demonstrated higher estimation errors, failing to represent the actual spatial patterns, while a stratified adaptive cluster sampling design achieved the best performance

Performance comparison of sampling designs for quality and safety control of raw materials in bulk: a simulation study based on NIR spectral data and geostatistical analysis

This study exploits the potential of near infrared (NIR) spectroscopy to deliver a measurement for each sampling point. Furthermore, it provides a protocol for the modelling of the spatial pattern of analytical constituents. On the basis of these two aspects, the methodology proposed in this work offers an opportunity to provide a real-time monitoring system to evaluate raw materials, easing and optimising the existing procedures for sampling and analysing products transported in bulk. In this paper, Processed Animal Proteins (PAPs) were selected as case study, and two types of quality/safety issues were tested in PAP lots —induced by moisture and cross-contamination. A simulation study, based on geostatistical analysis and the use of a set of sampling protocols, made a qualitative analysis possible to compare the representation of the spatial surfaces produced by each design. Moreover, the Root Mean Square Error of Prediction (RMSEP), calculated from the differences between the analytical values and the geostatistical predictions at unsampled locations, was used to measure the performance in each case. Results show the high sensitivity of the process to the sampling plan used — understood as the sampling design plus the sampling intensity. In general, a gradual decrease in the performance can be observed as the sampling intensity decreases, so that unlike for higher intensities, the too low ones resulted in oversmoothed surfaces which did not manage to represent the actual distribution. Overall, Stratified and Simple Random samplings achieved the best results in most cases. This indicated that an optimal balance between the design and the intensity of the sampling plan is imperative to perform this methodology

Purification and biochemical characterization of four iron superoxide dismutases in Trypanosoma cruzi

Four superoxide dismutase (SOD) activities (SOD I, II, III, and IV) have been characterized in the epimastigote form of Trypanosoma cruzi . The total extract was subjected to two successive ammonium sulphate additions between 35 and 85%, and the resulting fraction was purified using two continuous chromatography processes (ion exchange and filtration). Enzymes were insensitive to cyanide but sensitive to hydrogen peroxide, properties characteristic of iron-containing SODs. The molecular masses of the different SODs were 20 kDa (SOD I), 60 kDa (SOD II), 50 kDa (SOD III) and 25 kDa (SOD IV), whereas the isoelectric points were 6.9, 6.8, 5.2 and 3.8, respectively. Subcellular location and digitonin experiments have shown that these SODs are mainly cytosolic, with small amounts in the low- mass organelles (SOD II and SOD I) and the mitochondrion (SOD III), where these enzymes play an important role in minimizing oxidative damage.Financial support: CGL2006-27889-E/BOS, Ministerio de Ciencia y Tecnología

Mitochondrial phylogeography and demographic history of the Vicuña: implications for conservation

The vicuña (Vicugna vicugna; Miller, 1924) is a conservation success story, having recovered from near extinction in the 1960s to current population levels estimated at 275 000. However, lack of information about its demographic history and genetic diversity has limited both our understanding of its recovery and the development of science-based conservation measures. To examine the evolution and recent demographic history of the vicuña across its current range and to assess its genetic variation and population structure, we sequenced mitochondrial DNA from the control region (CR) for 261 individuals from 29 populations across Peru, Chile and Argentina. Our results suggest that populations currently designated as Vicugna vicugna vicugna and Vicugna vicugna mensalis comprise separate mitochondrial lineages. The current population distribution appears to be the result of a recent demographic expansion associated with the last major glacial event of the Pleistocene in the northern (18 to 22°S) dry Andes 14–12 000 years ago and the establishment of an extremely arid belt known as the 'Dry Diagonal' to 29°S. Within the Dry Diagonal, small populations of V. v. vicugna appear to have survived showing the genetic signature of demographic isolation, whereas to the north V. v. mensalis populations underwent a rapid demographic expansion before recent anthropogenic impacts

CF2 Represses Actin 88F Gene Expression and Maintains Filament Balance during Indirect Flight Muscle Development in Drosophila

The zinc finger protein CF2 is a characterized activator of muscle structural genes in the body wall muscles of the Drosophila larva. To investigate the function of CF2 in the indirect flight muscle (IFM), we examined the phenotypes of flies bearing five homozygous viable mutations. The gross structure of the IFM was not affected, but the stronger hypomorphic alleles caused an increase of up to 1.5X in the diameter of the myofibrils. This size increase did not cause any disruption of the hexameric arrangement of thick and thin filaments. RT-PCR analysis revealed an increase in the transcription of several structural genes. Ectopic overexpression of CF2 in the developing IFM disrupts muscle formation. While our results indicate a role for CF2 as a direct negative regulator of the thin filament protein gene Actin 88F (Act88F), effects on levels of transcripts of myosin heavy chain (mhc) appear to be indirect. This role is in direct contrast to that described in the larval muscles, where CF2 activates structural gene expression. The variation in myofibril phenotypes of CF2 mutants suggest the CF2 may have separate functions in fine-tuning expression of structural genes to insure proper filament stoichiometry, and monitoring and/or controlling the final myofibril size

Risk of ischaemic heart disease and acute myocardial infarction in a Spanish population: observational prospective study in a primary-care setting

BACKGROUND: Ischaemic heart disease is a global priority of health-care policy, because of its social repercussions and its impact on the health-care system. Yet there is little information on coronary morbidity in Spain and on the effect of the principal risk factors on risk of coronary heart disease. The objective of this study is to describe the epidemiology of coronary disease (incidence, mortality and its association with cardiovascular risk factors) using the information gathered by primary care practitioners on cardiovascular health of their population. METHODS: A prospective study was designed. Eight primary-care centres participated, each contributing to the constitution of the cohort with the entire population covered by the centre. A total of 6124 men and women aged over 25 years and free of cardiovascular disease agreed to participate and were thus enrolled and followed-up, with all fatal and non-fatal coronary disease episodes being registered during a 5-year period. Repeated measurements were collected on smoking, blood pressure, weight and height, serum total cholesterol, high-density and low-density lipoproteins and fasting glucose. Rates were calculated for acute myocardial infarction and ischaemic heart disease. Associations between cardiovascular risk factors and coronary disease-free survival were evaluated using Kaplan-Meier and Cox regression analyses. RESULTS: Mean age at recruitment was 51.6 ± 15, with 24% of patients being over 65. At baseline, 74% of patients were overweight, serum cholesterol over 240 was present in 35% of patients, arterial hypertension in 37%, and basal glucose over 126 in 11%. Thirty-four percent of men and 13% of women were current smokers. During follow-up, 155 first episodes of coronary disease were detected, which yielded age-adjusted rates of 362 and 191 per 100,000 person-years in men and women respectively. Disease-free survival was associated with all risk factors in univariate analyses. After multivariate adjustments, age, male gender, smoking, high total cholesterol, high HDL/LDL ratio, diabetes and overweight remained strongly associated with risk. Relative risks for hypertension in women and for diabetes in men did not reach statistical significance. CONCLUSION: Despite high prevalence of vascular risk factors, incidence rates were lower than those reported for other countries and other periods, but similar to those reported in the few population-based studies in Spain. Effect measures of vascular risk factors were mainly as reported worldwide and support the hypothesis that protective factors not considered in this study must exist as to explain low rates. This study shows the feasibility of conducting epidemiological cohort studies in primary-care settings