Productivity of American psychologists: Quantity versus quality.

"The answer to the question as to whether high producers also produce higher quality work seems to depend upon the severity of the criterion used to measure quality. If a severe criterion is used, the difference tends to favor the low producers. If less severe criteria are used, the high producers are favored. Although these results make it appear doubtful that high producers do better research than psychologists in general, they still make a greater contribution to the field by virtue of publishing a greater absolute number of high quality articles." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparability and repeatability of methods for estimating the dietary intake of the heterocyclic amine contaminant 2-amino-1-methyl-6-phenylimidazo[4,5b]pyridine (PhIP)

Inconsistent risk estimates for dietary heterocyclic amine (HCA) exposure and cancers may be due to differences in exposure assessment methods and the associated measurement error. We evaluated repeatability and comparability of intake estimates of the HCA 2-amino-1-methyl-6-phenylimidazo[4,5b]pyridine (PhIP) among two food frequency questionnaire (FFQ) collections, three diary collections, and three measurements of urinary PhIP and its metabolites in 36 non-smokers in Baltimore, Maryland, during 2004-2005. Collections spanned ～9 months. Method repeatability was characterised with intraclass correlation coefficients (ICCs). Comparability among methods was assessed with Spearman correlation coefficients. Within-subject variability in PhIP intake was comparably high across all methods (ICCs of 0.20, 0.30, and 0.15 for FFQ, diary, and creatinine-adjusted urinary PhIP, respectively). Mean diary-based PhIP intake and mean urinary PhIP concentration were strongly correlated when restricting the analysis to participants with at least one non-zero diary-based estimate of PhIP intake (n?=?15, r?=?0.75, p?=?0.001), but not in the full study population (n?=?36, r?=?0.18, p?=?0.28). Mean PhIP intake from the FFQ was not associated with that either based on the diary or urinary PhIP separately, but was modestly correlated with a metric that combined the diary- and biomarker-based approaches (r?=?0.30, p?=?0.08). The high within-subject variability will result in significantly attenuated associations if a single measure is used to estimate exposure within an epidemiologic study. Improved HCA assessment tools, such as a combination of methods or validated biomarkers that capture long term exposure, are needed.     

Environmental lighting on dynamic objects using hemicube bit masks

We present a method for environmental lighting on rigid objects that move within a static environment, such as cars driving through a city. Self-occlusion of the objects and occlusion due to the environment are precomputed and stored in hemicube bit masks. At run-time, local and environmental occlusion are rotated to a common space, combined and integrated with the BRDF. We show that all these computations can be done very efficiently with hemicube bit masks, resulting in real-time frame rates even for glossy objects and large environments.     

Improved equivalent circuit and analytical model for amorphoussilicon solar cells and modules

An improved equivalent circuit for hydrogenated amorphous silicon (a-Si:H) solar cells and modules is presented. It is based on the classic combination of a diode with an exponential current-voltage characteristic, of a photocurrent source plus a new term representing additional recombination losses in the i-layer of the device. This model/equivalent circuit matches the I(V) curves of a-Si:H cells over an illumination range of six orders of magnitude. The model clearly separates effects related to the technology of the device (series and parallel resistance) and effects related to the physics of the p-i-n junction (recombination losses). It also allows an effective μτ product in the i-layer of the device to be determined, characterizing its state of degradation     

a-Si:H/a-Si:H stacked cell from VHF-deposition in a single chamber reactor with 9% stabilized efficiency

In the present paper we present results on a-Si:H/a-Si:H stacked cells deposited in a single-chamber reactor by the very high frequency-glow discharge (VHF-GD) deposition technique at 70 MHz. Hydrogen dilution of the i-layer yields more stable amorphous p-i-n solar cells, similar to what is observed for RF deposition. High dilution ratios of the i-layer are found to enhance contaminations. This is, for the single-chamber reactor, due to the etching effect of the highly reactive H₂-plasma. Additionally, oxygen incorporation into the i-layer is favored by the high hydrogen dilution. Different means to suppress the contaminations are employed and discussed. Regarding the stacked cell design, we show by experiment and simulation that it is important to carefully adjust the current mismatch between the component cells such as to obtain a slight top-cell-limited behavior after degradation. We present an a-Si:H/a-Si:H stacked cell with an initial efficiency of 9.8% showing only 8% relative degradation which results in a stabilized efficiency of 9%. The deposition rate of the employed H₂-diluted i-layer material is 4 Å/s. It is therefore demonstrated that it is possible to make highly efficient stacked cells showing good stability also in a single-chamber system and employing the VHF technique to obtain higher rates.     

Miniaturized, high-power diode-pumped, Q-switched Nd:YAG laser oscillator-amplifier

A miniaturized, passively Q-switched Nd:YAG laser oscillator-power amplifier is reported, which is axially pumped by a compact, fiber-coupled, high-power, quasi-cw diode laser module. The pumping intensity of the oscillator crystal can be adjusted independently of the pumping intensity of the amplifier. This ensures that the oscillator pulse enters the amplifier when its maximum population density is reached. Furthermore, pulse bursts can be generated with a definite, adjustable number of single pulses. Maximum pulse energies of 8.4?and 22?mJ were achieved for a single pulse and for a pulse burst, respectively, at a pumping power of 470?W. The pulse widths were 2?ns, whereas the beam quality corresponded to M2<1.5. The laser is appropriate for scaling the power to the 10?MW range. Operation by using a 100?m pumping fiber was demonstrated.     

What happens with cow behavior when replacing concrete slatted floor by rubber coating: a case study

An enhanced productive life cycle and improved animal welfare are aims pursued in dairy husbandry. This study assesses experimental observations on floor-associated behavior during the stepwise replacement of concrete slatted flooring by rubber mats. For this purpose, estrus (mounting) and hygiene behavior (licking while standing on 3 legs and caudal licking) within a herd of 50 loose-housed Brown Swiss dairy cows were analyzed by video observation before and after floor reconstruction. Still photographs and pedometers were used to asses step length and number of steps, representing walking behavior. Compared with the concrete floor surface, rubber coating led to an increase in step length (58 ± 1 vs. 70 ± 1 cm; n = 35) and in steps per day (4,226 ± 450 vs. 5,611 ± 495; mean ± SEM; n = 9). Mounting was higher on the flooring covered with rubber mats (23 vs. 112). Collapsing or slipping during mounting only occurred on concrete slatted flooring (in 19 out of 23 mounting actions). Licking while standing on 3 legs and caudal licking increased up to 4-fold (105 vs. 511 observations). In conclusion, improvements were found in behavior when rubber-coated slatted floor surfaces were used in dairy cattle housing in transition from concrete flooring. Disorders in estrus and hygiene behavior were associated with the flooring of the barn and were relatively easy to investigate within the framework of farm welfare assessments.