Foodborne illness outbreaks from microbial contaminants in spices, 1973–2010

This review identified fourteen reported illness outbreaks attributed to consumption of pathogen-contaminated spice during the period 1973–2010. Countries reporting outbreaks included Canada, Denmark, England and Wales, France, Germany, New Zealand, Norway, Serbia, and the United States. Together, these outbreaks resulted in 1946 reported human illnesses, 128 hospitalizations and two deaths. Infants/children were the primary population segments impacted by 36% (5/14) of spice-attributed outbreaks. Four outbreaks were associated with multiple organisms. Salmonella enterica subspecies enterica was identified as the causative agent in 71% (10/14) of outbreaks, accounting for 87% of reported illnesses. Bacillus spp. was identified as the causative agent in 29% (4/10) of outbreaks, accounting for 13% of illnesses. 71% (10/14) of outbreaks were associated with spices classified as fruits or seeds of the source plant. Consumption of ready-to-eat foods prepared with spices applied after the final food manufacturing pathogen reduction step accounted for 70% of illnesses. Pathogen growth in spiced food is suspected to have played a role in some outbreaks, but it was not likely a contributing factor in three of the larger Salmonella outbreaks, which involved low-moisture foods. Root causes of spice contamination included contributions from both early and late stages of the farm-to-table continuum.     

Process control for error-free software: a software success story

Can you develop a bug-free mission-critical system on time? This author's customized approach delivered a highly sensitive missile warning system to NORAD's Cheyenne Mountain Operations Center within budget and meeting all the customer requirements     

Analysis of a low-pass filter employing a 4-pin capacitor

Capacitors with two or three leads tend to make poor low-pass filters at high frequencies (e.g., >100 MHz) due to the mutual inductance between the input and output sides of the filter. This work proposes a four-lead low-pass filter capacitor design that minimizes the magnetic flux coupling between the input and output. Measurements of a prototype capacitor confirm that it performs significantly better than a typical two-lead capacitor at high frequencies.     

An EMI estimate for shielding-enclosure evaluation

A relatively simple, closed-form expression has been developed to estimate the EMI from shielding enclosures due to coupling from interior sources through slots and apertures at the enclosure cavity modes. A power-balance method, Bethe's (1944) small-hole theory, and empirically developed formulas for the relation between radiation, and slot length and number of slots, were employed to estimate an upper bound on the radiated EMI from shielding enclosures. Comparisons between measurements and estimated field strengths suitably agree within engineering accuracy     

Quantifying SMT decoupling capacitor placement in dc power-busdesign for multilayer PCBs

Noise on a dc power-bus that results from device switching, as well as other potential mechanisms, is a primary source of many signal integrity (SI) and electromagnetic interference (EMI) problems. Surface mount technology (SMT) decoupling capacitors are commonly used to mitigate this power-bus noise. A critical design issue associated with this common practice in high-speed digital designs is placement of the capacitors with respect to the integrated circuits (ICs). Local decoupling, namely, placing SMT capacitors in proximity to ICs, is investigated in this study. Multilayer PCB designs that employ entire layers or area fills for power and ground in a parallel plate structure are considered. The results demonstrate that local decoupling can provide high-frequency benefits for certain PCB geometries through mutual inductive coupling between closely spaced vias. The associated magnetic flux linkage is between the power and ground layers. Numerical modeling using an integral equation formulation with circuit extraction is used to quantify the local decoupling phenomenon. Local decoupling can effectively reduce high-frequency power-bus noise, though placing capacitors adjacent to ICs may limit routing flexibility, and tradeoffs need to be made based on design requirements. Design curves are generated as a function of power-bus layer thickness and SMT capacitor/IC spacing using the modeling approach to quantify the power-bus noise reduction for decoupling capacitors located adjacent to devices. Measurement data is provided to corroborate the modeling approach     

Differential effects of load stiffness on matching pinch force, finger span, and effort

(1) The effects of the neurotoxin 3-acetylpyridine on the levels of soluble proteins and enzyme activities in various tissues of Japanese quail were investigated. (2) SDS-polyacrylamide gel electrophoresis showed that in the brain the soluble proteins with a molecular mass corresponding to 18 kDa were increased in quail treated with this toxin. The soluble liver proteins with the largest molecular masses (200, 120, 98, 80.5 and 58 kDa) were either missing or present at lower concentrations in the treated group compared to those in the controls while those of lower molecular mass (62, 55, 45, 36.5 and 24 kDa) were found to be present in higher concentrations. Similarly, treatment with 3-acetylpyridine tended to decrease the concentration of soluble proteins in pectoral muscle having a high molecular mass (160, 98, 60, 33, 30.5, 22 and 14 kDa) and to increase those having a low molecular mass (26, 20, 19.5 and 16 kDa). (3) There was a marked reduction in the treatment group in the concentration of NAD in pectoral muscle but not in other tissues. A similar observation was also made with total RNAs levels. (4) The specific activity of malic enzyme and glyceraldehyde-3-phosphate dehydrogenase was markedly reduced in the liver and pectoral muscle of the treatment group but was not affected in other tissues. The specific activity of 6-phosphogluconate dehydrogenase was significantly lower in the liver only, and that of lactic dehydrogenase and acetylcholinesterase was not affected in any of the tissues examined. (5) The results suggest that the metabolic actions of 3-acetylpyridine are quite distinct from those shown by niacin deficiency and its analog such as 6-aminonicotinamide.     

Identification of genes controlling germ cell migration and embryonic gonad formation in Drosophila

Gonadogenesis in the Drosophila embryo is a complex process involving numerous cellular migratory steps and cell-cell interactions. The mechanisms guiding germ cells to move through, recognize and adhere to specific cell types are poorly understood. In order to identify genes that are required for these processes, we have conducted an extensive mutagenesis of the third chromosome and screened for mutations disrupting germ cell migration at any point in embryonic development. Phenotypic analysis of these mutants demonstrates that germ cell migration can be broken down into discrete developmental steps, with each step requiring a specific set of genes. Many of these genes are involved in the development of gonadal mesoderm, the tissue that associates with germ cells to form the embryonic gonad. Moreover, mutations that we isolated affecting embryonic patterning as well as germ cell migration suggest that the origin of gonadal mesoderm lies within the eve domain of the developing mesoderm.     

Numerical modeling of electrostatic discharge generators

The discharge current and the transient fields of an electrostatic discharge (ESD) generator in the contact mode are numerically simulated using the finite-difference time-domain method. At first the static field is established. Then the conductivity of the relay contact is changed, which initiates the discharge process. The simulated data are used to study the effect of design choices on the current and fields. They are compared to measured field and current data using a multidecade broadband field and current sensors. The model allows accurate prediction of the fields and currents of ESD generators, thus it can be used to evaluate different design choices.