The corruption process of a law enforcement officer: a paradigm of occupational stress and deviancy

The public does not want all laws enforced. In the closed society of law enforcement institutions, police discretion, the conspiracy of silence, the lack of an administration with integrity, and susceptible law enforcement officers contribute to the development of corruption from occupational deviance. Corruption in law enforcement agencies may have similar roots in business, law, medicine, and other professions. Understanding the law enforcement corruption paradigm may therefore be helpful in correcting and curbing corruption in other professions.     

Development and evaluation of a compliance test for patients taking disulfiram

A breath test for carbon disulfide, a major excretion product of disulfiram, is described and evaluated. All breath excretions were standardized by collecting a fixed amount based on CO2 control. Excretion of CS2 falls rapidly (half life 8 to 18 hours), so that 20 to 30 hours following the last dose of disulfiram the test becomes negative. Approximately 300 tests in hospitalized patients taking disulfiram were positive; 40 tests in patients not taking this drug were negative. In an active disulfiram outpatient clinic more than one third of the patients who claimed to have taken disulfiram on the previous day had, as determined by this test, failed to do so. Of subjects judged by the professional staff to be almost certainly compliant 20% were not taking medication. Of the total of 52 patients tested in clinic only 25 were taking disulfiram.     

Decreased uptake of 14C-labeled dicarboxylic amino acids in rapidly growing hepatomas

In contrast to the increased uptake of amino acids which has been found in many neoplastic cells, we have observed a decrease in the net uptake of [14C]aspartate and [14C]glutamate in rapidly growing hepatomas relative to rat host liver. When measured 10 min after s.c. injection, the radioactivity from 14C-labeled dicarboxylic amino acids was greater in liver than in all other tissues examined (blood, skeletal, muscle, heart, spleen, lung, and brain) except kidney, where there was an approximately 2-fold greater uptake of aspartate and 10-fold greater uptake of glutamate. Mean uptakes in the rapidly growing Morris hepatomas 7288CTC and 7777 were 19 to 26% of corresponding values for the host livers. Comparison with uptake of 3H2O indicated that these low values were not solely due to differences in circulation. Decreased uptake was not accompanied by equivalent decreases in the concentration of aspartate and glutamate in the tumors. There were small changes in the net uptake of these amino acids in the slowly growing hepatoma 7787 and no significant differences in regenerating liver and hepatoma 5123C, a tumor of intermediate growth rate. The net uptake of [14C]arginine and [14C]lysine in the hepatomas was similar to that in host livers, except for a 250% increase in uptake of [14C]lysine in hepatoma 5123C. A decreased uptake of the magnitude seen with dicarboxylic amino acids in rapidly growing hepatomas has not been observed with other amino acids.     

Apical meristems: the plant's fountain of youth

During postembryonic development, all organs of a plant are ultimately derived from a few pluripotent stem cells found in specialized structures called apical meristems. Here we discuss our current knowledge about the regulation of plant stem cells and their environments with main emphasis on the shoot apical meristem of Arabidopsis thaliana. Recent studies suggest that stem cells are localized in specialized niches where signals from surrounding cells maintain their undifferentiated state. In the shoot meristem, initiation of stem cells during embryogenesis, regulation of stem-cell homeostasis and termination of stem-cell maintenance during flower development appear to primarily involve regulation of the stem-cell niche.     

Leachate from Land Disposed Residential Construction Waste

Solid waste from construction and demolition (C&D) activities is often disposed in unlined landfills. Leachate from unlined landfills poses a potential risk to groundwater quality. An understanding of the types of chemical constituents likely to be encountered in C&D waste landfill leachate and the concentrations at which they occur help assess this risk. An experiment was performed to characterize leachate from land-disposed residential construction waste. Four 54 m2 (580 ft2) test cells were excavated, lined, and filled with waste. Leachate samples were collected and analyzed for a number of water quality parameters over a 6 month period. No volatile or semivolatile organic compounds were detected at elevated constituent levels in the leachate. Inorganic ions were found to account for the bulk of the pollutant mass leached. Calcium and sulfate were the predominant ions in the leachate, resulting from the dissolution of gypsum drywall. The concentrations of several leachate constituents were found to exceed water quality standards. These constituents included aluminum, arsenic, copper, manganese, iron, sulfate, and total dissolved solids. Arsenic was the only primary water quality standard exceeded. The arsenic was concluded to result from chromated copper arsenate (CCA)-treated wood. The potential risk of impacting groundwater was examined by comparing the measured constituent concentrations with the water quality standards to assess the amount of dilution and attenuation needed in the groundwater so that a water quality standard would not be exceeded. The water quality standard exceeded by the greatest magnitude was manganese, followed by iron.     

Two are Better than One: Combining ZnO and MgF2 Nanoparticles Reduces Streptococcus pneumoniae and Staphylococcus aureus Biofilm Formation on Cochlear Implants

Streptococcus pneumoniae (S. pneumoniae) and Staphylococcus aureus (S.aureus) are considered the most common colonizers of cochlear implants (CI), which have prompted the search for new ways to inhibit their growth and biofilm development. In the current study, CI‐based platforms are prepared and sonochemically coated with ZnO or MgF₂ nanoparticles (NPs), two agents previously shown to possess antibacterial properties. Additionally, a method is developed for coating both ZnO and MgF₂ on the same platform to achieve synergistic activity against both pathogens. Each surface is characterized, and the optimal conditions for the NP homogenous distribution on the surface are determined. The ZnO‐MgF₂ surface significantly reduces the S. pneumoniae and S. aureus biofilm compared with the surfaces coated with either ZnO or MgF₂, even though it contains smaller amounts of each NP type. Importantly, leaching assays show that the NPs remain anchored to the surface for at least 7 d. Finally, biocompatibility studies demonstrate that coating with low concentrations of ZnO‐MgF₂ results in no toxicity toward primary human fibroblasts from the auditory canal. Taken together, these findings underscore the potential of using NP combinations such as the one presented here to efficiently inhibit bacterial colonization and growth on medical devices such as CIs.     

Effects of contact pressure,molecular weight,and supplier on the wear behavior and transfer film of polyetheretherketone (PEEK)

Polyetheretherketone (PEEK) is a designation given to materials of the polyaryletherketone family having a characteristic distribution of ether and ketone groups in the polymer backbone. PEEK materials have high strength and chemical resistance as well as very high melting points and glass transition temperatures. Because of this combination of properties, PEEK materials find use for wear application in extreme environments where they provide a light-weight and corrosion resistant bearing material that often does not require lubrication. This study focused on determining the effects of supplier and molecular weight on the wear of particular PEEK materials, in addition to the effect of contact pressure. Multidirectional wear testing was performed on four PEEK materials. The materials were obtained from two different suppliers, and two molecular weights were chosen for each supplier. Extensive analysis of transfer films produced during wear testing was performed using optical microscopy. White light profilometry was used to measure transfer film thickness in order to calculate a mean film thickness for given experimental conditions. Dynamic mechanical analysis, as well as gel permeation chromatography and differential scanning calorimetry were used to characterize each material's viscoelastic behavior, molecular weight, and crystallinity, respectively. It was found that the wear of PEEK materials was significantly affected by both contact pressure and molecular weight, but not by supplier. However, an interaction was observed that showed the low molecular weight material from one of the suppliers was more vulnerable to wear at high contact pressures than the other three materials. Results of transfer film analysis showed that film thickness was greatest in locations where pin sliding direction was perpendicular to the counterface roughness direction, but that mean transfer film thickness did not correlate to wear amounts. This work is significant because it highlights the fact that tribologically relevant polymers, such as PEEK materials, vary greatly in terms of their polymer morphology and processing history, and this variation must be recognized by investigators when reporting wear data.     

Potential use of physical measurements including ultrasound for a better mango fruit quality characterization

The potential use of ultrasound measurements, combined with other physical measurements, has been investigated. The good relationship between soluble solids content (SSC) and ultrasonic wave velocity reported in the literature being confirmed by our study, our main goal was to evaluate the added value of ultrasound measurements around 25 MHz for the determination of biochemical compounds responsible of organoleptic quality of mangoes. Among the main sugar constituents of mango juice, only sucrose content prediction was improved by combining SSC and ultrasonic waves velocity using a PLS model (R² = 0.81, RMSECV = 12.3, bias = 0.10, RPD = 2.3) when compared to the linear model with SSC only (R² = 0.75, SEP = 14.05, bias = 0.08). The same conclusion was obtained for titratable acidity PLS model using whole fruit hardness, SSC and ultrasonic wave velocity (R² = 0.82, RMSECV = 1.84, bias = 0.02, RPD = 2.4) compared to the linear model with fruit hardness only (R² = 0.78, SEP = 2.07, bias = 0.02). However, the added value of ultrasound measurements was not always found to be significant (P = 0.05) when a Wilcoxon statistical tests was conducted on the residuals of the linear and PLS models for both sucrose and titratable acidity.