The effects of error transformations on classification performance.

Four experiments investigated the effects of error transformations on performance in a variety of classification tasks. Error transformations alter the sequencing of stimuli on the basis of previous subjects' errors, and two main versions of such transformations were tested, the recency and summation methods. The recency method resulted in consistent performance improvements across repeated levels of transformation in a variety of tasks, including the classification of English sentences, male and female handwriting, and samples of commercial lumber. The summation method produced initial improvements, and then degraded. Attempts to simulate the effects using similarity models of classification succeeded in reproducing the recency effect but failed to reproduce the summation effect. The article closes with some conjectures as to the reasons for the effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Health-related quality of life is maintained in hemodialysis patients receiving pharmaceutical care: A 2-year randomized, controlled study

End-stage renal disease and initiation of hemodialysis (HD) adversely affect health-related quality of life (HRQOL). There are currently no data evaluating the effect of pharmaceutical care (PC) on HRQOL in HD patients. HD patients were randomized to receive PC; one-on-one, in-depth medication reviews conducted by a clinical pharmacist or Standard of Care (SOC); and brief medication reviews conducted by dialysis nurses. The renal quality of life profile (RQLP) was administered at baseline and then at 1 and 2 years after study initiation. The RQLP is a 43-item questionnaire that has 5 dimensions: Eating/Drinking, Physical Activities, Leisure Time, Psychosocial Activities, and Impact of Treatment, where increasing scores reflect worsening of HRQOL. A total of 107 patients were enrolled (SOC: n=46; PC: n=61). Besides gender, there were no differences in the demographics or the baseline total RQLP scores. The mean±SD total RQLP scores at Year 1 were significantly worse in SOC compared with PC (88±31 vs. 71±34, respectively; P=0.03). Significant worsening of Eating and Drinking (5.9±3.3 vs. 4.4±3.1, respectively; P=0.04), Physical Activities (37±13.6 vs. 30±16.3, respectively; P=0.04), and Leisure Time scores (8.3±3.4 vs. 5.9±3.6, respectively; P=0.03) was also observed in the SOC group. After 2 years, only the SOC patients had worsening of Leisure Time (7.5±3.0 vs. 5.2±3.9, respectively; P=0.04). No other parameters were different between the groups after 2 years. These data indicate that patients who have clinical care provided by pharmacists do not have worsened HRQOL after 1 year and are able to maintain HRQOL for an additional year.     

Ultrafiltration separation of aquatic natural organic matter: Chemical probes for quality assurance

Characterization of molecular size of natural organic matter (NOM) is a valuable tool when assessing its effect on the performance of water treatment systems as well as its geochemical origin. Size fractionation can be accomplished by ultrafiltration (UF). Unfortunately, membrane manufacturing generates a range of pore sizes. Many membrane manufacturers use molecular weight cutoff (MWCO) metric based on a 90% retention of given solute after specified duration of filtration. The objective of this study was to characterize the ability of different commercially available UF membranes to separate different size fractions of NOM. The UF membranes characterized were YM (regenerated cellulose, negatively charged) and PB (polyethersulfone, negatively charged) product lines by Millipore™. The probes used to represent the size, shape and charge of NOM were polymers (polyethylene glycols (PEGs), dextrans, polystyrene sulfonates (PSSs)), dyes (bromocresol green, congo red, methyl red, methyl orange) and biological molecules (vitamin B-12 and bacitracin). The results show that MWCO definition does not hold for membranes of 5 kDa and 10 kDa pore openings using most polymers and dyes. The MWCO definition holds for 1 kDa membrane for all tested probes. Under natural water conditions PSSs assume random coil configurations that are nearly identical to Suwannee fulvic acid. The results show that PSS agrees with stated MWCOs. The study demonstrates that ultrafiltration is not a simple mechanical sieving process, but that charges on the membrane and the constituent play a significant role in the rejection process. Effective probe size was increased seven- to fourteen-fold by charge interactions between the negative probes and negatively charged membrane. Uncharged molecules larger than specified MWCOs are able to pass through pores (PEGs), while small charged molecules (dyes) do not pass. For probes with low or neutral charges, shape becomes an important factor, with globular being favored over linear structure. Thus, MWCOs cannot be trusted for purposes of NOM size characterization. The study recommends the use of YM 1 K, PB 5 K and YM 10 kDa membranes for comparative-only NOM size ultrafiltration characterization within the 1–10 kDa size range.     

Electron‐Rich Alcohol‐Soluble Neutral Conjugated Polymers as Highly Efficient Electron‐Injecting Materials for Polymer Light‐Emitting Diodes

We report the design and synthesis of three alcohol‐soluble neutral conjugated polymers, poly[9,9‐bis(2‐(2‐(2‐diethanolaminoethoxy) ethoxy)ethyl)fluorene] (PF‐OH), poly[9,9‐bis(2‐(2‐(2‐diethanol‐aminoethoxy)ethoxy)ethyl)fluorene‐alt‐4,4′‐phenylether] (PFPE‐OH) and poly[9,9‐bis(2‐(2‐(2‐diethanolaminoethoxy) ethoxy)ethyl)fluorene‐alt‐benzothiadizole] (PFBT‐OH) with different conjugation length and electron affinity as highly efficient electron injecting and transporting materials for polymer light‐emitting diodes (PLEDs). The unique solubility of these polymers in polar solvents renders them as good candidates for multilayer solution processed PLEDs. Both the fluorescent and phosphorescent PLEDs based on these polymers as electron injecting/transporting layer (ETL) were fabricated. It is interesting to find that electron‐deficient polymer (PFBT‐OH) shows very poor electron‐injecting ability compared to polymers with electron‐rich main chain (PF‐OH and PFPE‐OH). This phenomenon is quite different from that obtained from conventional electron‐injecting materials. Moreover, when these polymers were used in the phosphorescent PLEDs, the performance of the devices is highly dependent on the processing conditions of these polymers. The devices with ETL processed from water/methanol mixed solvent showed much better device performance than the devices processed with methanol as solvent. It was found that the erosion of the phosphorescent emission layer could be greatly suppressed by using water/methanol mixed solvent for processing the polymer ETL. The electronic properties of the ETL could also be influenced by the processing conditions. This offers a new avenue to improve the performance of phosphorescent PLEDs through manipulating the processing conditions of these conjugated polymer ETLs.     

Crystallographic anisotropy of growth and etch rates of CVD diamond

The investigation of orientation dependent crystal growth and etch processes can provide deep insights into the underlying mechanisms and thus helps to validate theoretical models. Here, we report on homoepitaxial diamond growth and oxygen etch experiments on polished, polycrystalline CVD diamond wafers by use of electron backscatter diffraction (EBSD) and white-light interferometry (WLI). Atomic force microscopy (AFM) was applied to provide additional atomic scale surface morphology information. The main advantage of using polycrystalline diamond substrates with almost random grain orientation is that it allows determining the orientation dependent growth (etch) rate for different orientations within one experiment. Specifically, we studied the effect of methane concentration on the diamond growth rate, using a microwave plasma CVD process. At 1% methane concentration a maximum of the growth rate near <100> and a minimum near <111> is detected. Increasing the methane concentration up to 5% shifts the maximum towards <110> while the minimum stays at <111>. Etch rate measurements in a microwave powered oxygen plasma reveal a pronounced maximum at <111>. We also made a first attempt to interpret our experimental data in terms of local micro-faceting of high-indexed planes.     

Coping and adaptation to facial pain in contrast to other stressful life events.

Investigates whether coping with chronic pain influences adaptation to other negative life events using data on Temporomandibular Pain and Dysfunction Syndrome (TMPDS) patients (N?=?99) and nonpatient controls (N?=?98). It is found that cases cope very differently with pain than with other stressful events and that cases and controls do not differ on coping with nonpain events, with 2 exceptions. Cases view nonfateful events as more outside their control and they have more negative changes in usual activities following negative events. This excess of negative change is associated with greater demoralization and physical exhaustion. It is concluded that coping with repeated pain episodes leaves cases vulnerable to stressful events. Alternative interpretations, especially those involving the role of preexisting personality differences, are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)