An approach for assessing CCP effectiveness in food production applications by predictive QRA modelling

The basic process in creating hazard analysis and critical control point (HACCP) plans is that significant hazards associated with a food product are determined, and then the key steps where a hazard might occur in food production are redesigned in an effort to avoid insertion of a critical control point (CCP). In the event that it is not possible to remove the risk of a hazard by redesigning the process steps, a CCP should be inserted. Production of safe food ultimately relies on the effectiveness, i.e. the capability and reliability, of process design and, where necessary, control and monitoring systems at a CCP. Therefore, pre-established thresholds must be monitored and managed to ensure that food safety is maintained. Doménech et al. [Assessing the effectiveness of critical control points to guarantee food safety. Food Control 2008;19:557-65] proposed an original approach to quantify the effectiveness of a CCP based on the consideration of the capability and reliability of the control and monitoring system related to food manufacturing and public health. The article described a methodology for measuring the effectiveness of a CCP in terms of the risk to consumer health as well as the potential impact on company revenues. This paper presents the fundamentals of an application example of the methodology to integrate CCP effectiveness assessment into predictive QRA modelling. The method is original and its application in the food industry could provide the decision-maker with a quantitative tool for setting critical limits and monitoring variations at a CCP. This would allow risk management decisions to be made at-line (i.e., in real time) during a specific process. Not only could this prevent a hazardous food from reaching the consumer, but it also could contribute to reduced expense for the producer. The wasted expense of product completion incorporating a tainted material would be avoided as well as the potentially higher costs associated with product liability issues.     

Performance and energy effects on task-based parallelized applications

Heterogeneity, parallelization and vectorization are key techniques to improve the performance and energy efficiency of modern computing systems. However, programming and maintaining code for these architectures poses a huge challenge due to the ever-increasing architecture complexity. Task-based environments hide most of this complexity, improving scalability and usage of the available resources. In these environments, while there has been a lot of effort to ease parallelization and improve the usage of heterogeneous resources, vectorization has been considered a secondary objective. Furthermore, there has been a swift and unstoppable burst of vector architectures at all market segments, from embedded to HPC. Vectorization can no longer be ignored, but manual vectorization is tedious, error-prone and not practical for the average programmer. This work evaluates the feasibility of user-directed vectorization in task-based applications. Our evaluation is based on the OmpSs programming model, extended to support user-directed vectorization for different SIMD architectures (i.e., SSE, AVX2, AVX512). Results show that user-directed codes achieve manually optimized code performance and energy efficiency with minimal code modifications, favoring portability across different SIMD architectures.     

Blocking versus robustness in industrial contexts

The paper discusses the similarities and differences between blocking factors (blocked designs) and noise factors (robust designs) in industrial two‐level factorial experiments. The discussion covers from the objectives of both design types and the nature of blocking and noise factors to the types of designs and the assumptions needed in each case. The conclusions are as follows: the nature and characteristics of noise and blocking factors are equal or very similar; the designs used in both situations are also similar; and the main differences lie in the assumptions and the objectives. The paper argues that the objectives are not in conflict and can easily be harmonized. In consequence, we argue in favor of a unified approach that would clarify the issue, especially for students and practitioners.     

An approach to integrating surveillance and maintenance tasks to prevent the dominant failure causes of critical components

Surveillance requirements and maintenance activities in a nuclear power plant aim to preserve components' inherent reliability. Up to now, predictive and preventive maintenance mainly concerned plant staff, but the US Nuclear Regulatory Commission Maintenance Rule released in July 1991 will have significant impact on how nuclear power plants perform and document this maintenance. Reliability Centered Maintenance (RCM) is a systematic methodology to establish maintenance tasks for critical components in plant with a high degree of compliance with the goals of the Rule. RCM pursues the identification of applicable and efficient tasks to prevent these components from developing their dominant failure causes, and, in turn, towards achieving proper levels of components availability with low cost. In this paper, we present an approach for identifying the most suitable set of tasks to achieve this goal, which involves the integration of maintenance activities and surveillance requirements for each critical component based on the unavailability and cost associated with each individual task which is performed on it.     

Comparing effectiveness and efficiency in technical specifications and maintenance optimization

Optimization of technical specification requirements and maintenance (TS&M) has been found interesting from the very beginning at Nuclear Power Plants (NPPs). However, the resolution of such a kind of optimization problem has been limited often to focus only on individual TS&M-related parameters (STI, AOT, PM frequency, etc.) and/or adopting an individual optimization criterion (availability, costs, plant risks, etc.). Nevertheless, a number of reasons exist (e.g. interaction, similar scope, etc.) that justify the interest to focus on the coordinated optimization of all of the relevant TS&M-related parameters based on multiple criteria.The purpose of this paper is on signifying benefits and improvement areas in performing the coordinated optimization of TS&M through reviewing the effectiveness and efficiency of common strategies for optimizing TS&M at system level. A case of application is provided for a stand-by safety-related system to demonstrate the basic procedure and to extract a number of conclusions and recommendations from the results achieved. Thus, it is concluded that the optimized values depend on the particular TS&M-related parameters being involved and the solutions with the largest benefit (minimum risk or minimum cost) are achieved when considering the simultaneous optimization of all of them, although increased computational resources are also required. Consequently, it is necessary to analyze not only the value reached but also the performance of the optimization procedure through effectiveness and efficiency measures which lead to recommendations on potential improvement areas.     

Nitric oxide production by pig endothelial cells in response to human-derived injury

BACKGROUND: Metamorphopsia is a visual illusion that distorts the size, shape, or inclination of objects. Reversal of vision metamorphopsia (RVM) is a rare transient form of metamorphopsia described as an upside-down, 180 degrees rotation of the visual field in the coronal plane. The pathophysiological characteristics of RVM remain unclear. DESIGN: Patients with RVM had a complete neurologic examination during or shortly after an episode of metamorphopsia, with particular emphasis on gaze disorders, visual fields, visually guided hand movements, and perceptual or cognitive deficits. Workup included imaging studies, visual field examinations, and brainstem auditory and visual evoked response. SETTING: Department of Neurology, Hadassah University Hospital, Hebrew University-Hadassah Medical School, Jerusalem, Israel. PATIENTS: Six consecutive patients were evaluated from 1991 to 1996. RESULTS: Five patients had parieto-occipital brain insult sparing the primary visual cortex, and 3 also had evidence of a concomitant brainstem or cerebellar syndrome. One patient had pure brainstem syndrome underlying the RVM. Three patients had complete RVM as well as oblique RVM of less than 180 degrees. CONCLUSIONS: These cases imply a possible anatomical localization of the central integrator of visual extrapersonal orientation. Our observations suggest that a separate central mechanism of visual orientation might exist in each cerebral hemisphere and that occipital and parietal lesions that spare the optic radiations may account for the oblique and complete RVM. We postulate that failure to perceive space in an allocentric coordinate frame, particularly in the coronal roll plane, is potentially the critical event underlying RVM.     

Effect of prenatal multiple micronutrient supplements on maternal weight and skinfold changes: a randomized double-blind clinical trial in Mexico

BACKGROUND: Recent trials of prenatal multivitamin-mineral supplements have yielded mixed findings for outcomes such as birth size, but the benefits of prenatal multivitamin-mineral supplements for maternal outcomes are unknown. OBJECTIVE: The main objective of this study was to examine the effect of prenatal multiple micronutrient supplements (MM) compared to iron only (FE) supplements on changes in maternal weight and body composition during pregnancy and the early postpartum period. METHODS: A randomized double-blind clinical trial was conducted in semi-rural Mexico. Women received either MM or FE supplements, 6 days per week from early pregnancy to delivery. Anthropometric measurements were obtained at recruitment, 26 and 37 weeks pregnancy, and 1 month postpartum. Women in both groups were similar at recruitment except that body-mass index (BMI) was greater in the FE group. RESULTS: Mean weight gain during pregnancy was significantly greater (-0.6 kg) in the MM group (n = 283) compared to the FE group (n = 287), but not after adjusting for maternal BMI at recruitment. Overweight women in the MM group gained 0.53 kg between recruitment and 1 month postpartum, whereas those in the FE group lost 0.63 kg; there were no differences between experimental groups among non-overweight women (p =.06 for interaction). CONCLUSIONS: Compared to iron supplements, MM supplements did not increase weight gain during pregnancy after adjusting for baseline differences in BMI but may lead to greater postpartum weight retention among overweight women.     

The hospitalized child with asthma

The recent cloning of receptors for calcitonin (CT) and parathyroid hormone (PTH)/parathyroid hormone-related peptide (PTHrP) has enabled very rapid progress in understanding the molecular and cell biology of these receptors. In particular, much has been learnt about the tissue distribution of these receptors, as well as their mode of interaction with ligands, signal transduction and regulation of expression. The conventional view of these hormone-receptors systems as "calciotropic" has been broadened by recent work showing important developmental roles. Isoforms of the CT receptor (CTR), with interesting functional differences, have been identified and a new form of the PTH receptor, highly specific for PTH, has been cloned. Investigation of the homologous regulation of the CTR in osteoclasts by CT treatment of mouse marrow cultures, has shown that continuous exposure to CT results in formation of resorption competent, CTR-deficient osteoclasts. Treatment of mature osteoclasts causes a rapid and prolonged decrease in CTR mRNA levels, reflected in a loss of cell surface CTR. Since these cells regain resorption competence, the data support the concept that the clinical phenomenon of "escape" from the hypocalcemic action of CT results from a loss of CT sensitivity by osteoclasts to the hormone.     

Consequences of using estimated response values from negligible interactions in factorial designs

This article analyzes the increase in the probability of committing type I and type II errors in assessing the significance of the effects when some properly selected runs have not been carried out, and their responses have been estimated from the interactions considered null from scratch. This is done by simulating the responses from known models that represent a wide variety of practical situations that the experimenter will encounter; the responses considered to be missing are then estimated, and the significance of the effects is assessed. Through comparison with the parameters of the model, the errors are then identified. To assess the significance of the effects when there are missing values, the Box‐Meyer method has been used. The conclusions are that one missing value in eight run designs, and up to three missing values in 16 run designs experiments can be estimated without hardly any notable increase in the probability of error when assessing the significance of the effects.     

Sputtered NiO as electron blocking layer in P3HT:PCBM solar cells fabricated in ambient air

We fabricated P3HT:PCBM bulk hetero-junction solar cells, where a 5 nm layer of NiO sputtered on top of ITO is used as an effective electron blocking layer. All the steps involving the processing of the organic materials were performed in ambient air. Under 1 sun of AM1.5G illumination such NiO cells exhibited a power conversion efficiency of 3.3% compared to 3.1% exhibited by a PEDOT:PSS cell fabricated under similar conditions. We observed that for the NiO cell processing in air was not detrimental to the ulterior performance of the cell, which in ambient air degraded with a time constant of 303 h. On the contrary, the PEDOT:PSS cell degraded very rapidly and the loss in efficiency was shown to be 29 times faster when compared to that of the NiO cell.