Guidance on validation of lethal control measures for foodborne pathogens in foods

Food manufacturers are required to obtain scientific and technical evidence that a control measure or combination of control measures is capable of reducing a significant hazard to an acceptable level that does not pose a public health risk under normal conditions of distribution and storage. A validation study provides evidence that a control measure is capable of controlling the identified hazard under a worst-case scenario for process and product parameters tested. It also defines the critical parameters that must be controlled, monitored, and verified during processing. This review document is intended as guidance for the food industry to support appropriate validation studies, and aims to limit methodological discrepancies in validation studies that can occur among food safety professionals, consultants, and third-party laboratories. The document describes product and process factors that are essential when designing a validation study, and gives selection criteria for identifying an appropriate target pathogen or surrogate organism for a food product and process validation. Guidance is provided for approaches to evaluate available microbiological data for the target pathogen or surrogate organism in the product type of interest that can serve as part of the weight of evidence to support a validation study. The document intends to help food manufacturers, processors, and food safety professionals to better understand, plan, and perform validation studies by offering an overview of the choices and key technical elements of a validation plan, the necessary preparations including assembling the validation team and establishing prerequisite programs, and the elements of a validation report.     

Uniform Cooling of Alloys

A phase separation process model formed by the Cahn– Hilliard equation and the heat equation is considered. The mobility coefficient in the Cahn–Hilliard equation is assumed to be an increasing function of the temperature. This property is of importance at the latest stage of the cooling process. The existence and uniqueness of a weak solution is proved, and a uniform cooling problem is studied. Obtained results can be used to control the cooling process and to create alloys with a uniform structure. 2000 Mathematics Subject Classification. 35K30, 35Q99, 49J20.     

Desulphurization of damped battery paste by sodium carbonate and sodium hydroxide

The paper treats investigation of the desulphurization process of damped Pb-paste by Na₂CO₃ or NaOH. There is determined the effect of Na₂CO₃ (NaOH) concentration and the liquid–solid phase ratio on the process parameters (degree of desulphurization and degree of Na₂CO₃ (NaOH) utilization in function of the temperature and process duration). The optimum conditions for carrying out desulphurization of Pb-pastes by Na₂CO₃ or NaOH are determined in dependence of the used reactors (common reactor with laboratory agitator and rotary reactor of drum type). The content of inclusions in the solutions is examined with the purpose of producing sufficiently pure crystalline Na₂SO₄ for the industry.     

Computed tomography in a case of pseudomembranous colitis

Pseudomembranous colitis (PMC) is an infectious colitis usually occurring as a complication of antibiotic therapy. The computed tomography (CT) findings of 10 patients with PMC are reviewed. All patients demonstrated an abnormal large bowel wall with an average thickness of 13 mm (range 7-31 mm). Additional, but less frequent findings included mesenteric inflammation, ascites, pleural effusions, and dilatation of the large or small bowel. Pancolonic involvement was seen in 7 cases, while three patients had focal colitis. Although the CT appearance of PMC is not specific, the diagnosis may be suggested in the proper clinical setting.     

Maximum entropy for periodically correlated processes from nonconsecutive autocovariance coefficients

Abstract.  We consider the maximum entropy extension of a partially specified autocovariance sequence of a periodically correlated process. The sequence may be specified on a non-contiguous set. We give a method which solves the problem completely – it gives the positive definite solution when it exists and reports that it does not exist otherwise. The method is numerically reliable even when the solution is 'almost' semidefinite. It also works when only positive semidefinite extension(s) exist.     

Preparation and properties of RF sputtered indium-tin oxide thin films for applications as heat mirrors in photothermal solar energy conversion

In the present research, in order to deposit indium-tin oxide (ITO) thin films the method of RF reactive sputtering was used. Sputtering of two types indium-tin targets in the presence of oxygen as reactive gas was made. The technological parameters were optimized to obtain films with good quality on different substrates. The films' microstructure was studied by TEM and SAED. To identify the optical properties of the films the methods of infrared spectrometry and laser ellipsometry were used. UV-VIS spectrophotometry showed the high visible transmittance of the RF sputtered ITO films. Heating of the substrates during the films sputtering and their post deposition thermal treatment also were studied. The ultimate goal of the present research activities was to develop new technological processes leading to low-cost, highly effective optical coatings for application in photo thermal solar energy conversion and utilization.     

Behavior of blood pressure during pregnancy

In 948 women of the blood-pressure behaviour was registered weekly, from the 12. up to the 42. week of normal pregnancy. The normal range is stated with the single and double dissemination of the blood-pressure values; depending from the number of weeks being pregnant, and dessignation and meening to the pathological behaviour are represented. Desides, the frequency of various course-types of the blood-pressure during pregnancy is given, their possible meaning being discussed. For this purpose, 1337 single courses of the blood-pressure behaviour within pregnancy were explored.     

Biological controls in mixed trichostrongyle infections

The parasite reaction phenotype of 80 lambs was determined with natural infection on pasture. These lambs were then assigned to outcome groups and randomized into treatment groups. Developing some simple but unusual analytical techniques it was possible to demonstrate that mixed natural infections of trichostrongyles with the chief biomass component Haemonchus contortus cayugensis protected against superinfections with 35000 infective larvae but protected against superinfections with 1000 infective larvae per day only within the limits characteristic of the enclosing barn ecosystem. The limits of the barn ecosystem were less constraining on more diathetic sheep than the natural pasture infection. Internal evidence from the experiment suggests that the interaction of sheep X pasture X infective trichostrongylid larvae constrains the parasite biomass in the host in more diathetic animals at significantly lower levels. Anaphylactoid 'self-cure' did not occur in this experiment but something like premunition certainly did.