Tunable photoemission from an excitonic antitrap

We study the influence of lithographically defined, electrostatic trap configurations on the photon emission from dipolar excitons in coupled quantum wells. The emission is surprisingly enhanced for an excitonic antitrap compared to a trap configuration, an effect more pronounced for a trap with smaller diameter. We explain the observations by the interplay between the exciton formation process, the lateral charge-carrier dynamics, and the dipole-dipole interactions between the excitons. Exploiting this interplay allows us to efficiently tune the excitonic emission energy with very small intensity variation.     

Recovery, redemption, and extreme programming

The author retells a downtrodden project's attempt to rejuvenate itself by doing extreme programming, discussing successes, shortcomings, and, ultimately, lessons learned. In particular, the author credits the team's composition for its ultimate success. Although XP wasn't the team's immediate salvation, it made the application sustainable past the project's deadline     

Overexpression of the sarcolemmal calcium pump in the myocardium of transgenic rats

The plasma membrane calmodulin-dependent calcium ATPase (PMCA) is a calcium-extruding enzyme controlling Ca2+ homeostasis in nonexcitable cells. However, its function in the myocardium is unclear because of the presence of the Na+/Ca2+ exchanger. We approached the question of the physiological function of the calcium pump using a transgenic "gain of function" model. Transgenic rat lines carrying the human PMCA 4 cDNA under control of the ventricle-specific myosin light chain-2 promoter were established, and expression in the myocardium was ascertained at the mRNA, protein, and functional levels. In vivo hemodynamic measurements in adult homozygous animals showed no differences in baseline and increased cardiac performance recruited by volume overload compared with controls. No differences between transgenic and control cardiomyocytes were found in patch clamp voltage dependence, activation/inactivation behavior of the L-type Ca2+ current, or fast [Ca2+]i transients (assessed by the Fura-2 method). To test whether the PMCA might be involved in processes other than beat-to-beat regulation of contraction/relaxation, we compared growth processes of neonatal transgenic and control cardiomyocytes. A 1.6- and 2.3-fold higher synthesis rate of total protein was seen in cells from transgenic animals compared with controls on incubation with 2% FCS for 24 hours and 36 hours, respectively. An effect of similar magnitude was observed using 20 micromol/L phenylephrine. A 1.4-fold- and 2.0-fold-higher protein synthesis peak was seen in PMCA-overexpressing cardiomyocytes after stimulation with isoproterenol for 12 hours and 24 hours, respectively. Because pivotal parts of the alpha- and beta-adrenergic signal transduction pathways recently have been localized to caveolae, we tested the hypothesis that the PMCA might alter the amplitude of alpha- and beta-adrenergic growth signals by virtue of its localization in caveolae. Biochemical as well as immunocytochemical studies suggested that the PMCA in large part was colocalized with caveolin 3 in caveolae of cardiomyocytes. These results indicate that the sarcolemmal Ca2+-pump has little relevance for beat-to-beat regulation of contraction/relaxation in adult animals but likely plays a role in regulating myocardial growth, possibly through modulation of caveolar signal transduction.     

Suppression of dyskinesias in advanced Parkinson's disease: moderate daily clozapine doses provide long-term dyskinesia reduction

Dyskinesias commonly appear during L-dihydroxyphenylalanine (L-DOPA) therapy of advanced Parkinson's disease (PD) and can occur in both dose-related and dose-independent patterns. Clozapine exerts a dose-related suppression of L-DOPA-induced dyskinesias by shifting the i.v. L-DOPA dose-response curve for production of dyskinesias without altering relief of parkinsonism. We report our outpatient experience with 13 patients on daily clozapine therapy (maximum dose 400 mg/day), followed for 3-21 months (median 10). Beneficial effects of clozapine, determined from twice-weekly diaries, included increased "on time" and decreased "off time" and time "on with dyskinesia." Improvements were statistically apparent by 75 mg/day and remained so through 200 mg/day. Sedation was a common problem, reflected by increased time "asleep" which was significant by 50 mg/day. Sedation was dose limiting in most patients. Orthostatic hypotension and sialorrhea were variably present. No patients had seizures, bone marrow toxicity, or detectable loss of efficacy of clozapine with chronic use. We conclude that clozapine is an effective agent for suppression of dyskinesias in PD with an effective daily dose for most patients of 100-200 mg/day.     

Activation by marginally perceptible ("subliminal") stimuli: Dissociation of unconscious from conscious cognition.

Introduces a linear regression method for investigating unconscious cognition. For words that were obscured by simultaneous dichoptic masking, indirect effects (semantic priming) and direct effects (perceptual identification) were assessed in 20 experiments (total N?=?2,026). When measures of both indirect and direct effects have rational zero points, a statistically significant intercept in the indirect-on-direct-measure regression shows that (a) the indirect effect occurred in the absence of the direct effect, and (b) unconscious cognition is involved. For a position discrimination task, but not for an evaluative decision task, indirect-on-direct regression showed the significant intercept effect. Although small in magnitude, this intercept effect provides the statistically most secure finding yet obtained of a much-sought and controversial data pattern—indirect effect with no direct effect. With one added assumption (which appears plausible for the present data), this pattern indicates that unconscious cognition is dissociated from (i.e., occurs separately from) conscious cognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Penalty-free GSM-1800 and WCDMA radio-over-fibre transmission using multimode fibre and 850 nm VCSEL

Penalty-free GSM-1800 and WCDMA radio-over-fibre transmission over 600 m of multimode fibre using low-cost gigabit Ethernet components operating at 850 nm is presented.     

Influence of diterpene resin acids on feeding and growth of larch sawfly,Pristiphora erichsonii (Hartig)

Diterpene resin acids significantly affect consumption rates, feeding efficiencies, and growth rates of the larch sawfly,Pristiphora erichsonii (Hartig) when topically applied to their natural food, tamarackLarix laricina (DuRoi) K. Koch. Abietic acid, neoabietic acid, dehydroabietic acid, and isopimaric acid significantly reduced consumption rates, feeding efficiencies, and growth rates. Sandaracopimaric acid reduced growth and efficiency but did not influence consumption rate. Two-way analysis of variance indicates a significant interaction between chemical and concentration for growth rate, feeding efficiency, and consumption rate. This interaction indicates that increasing chemical concentrations do not influence the larch sawfly in a uniform manner, supporting the concept of concentration-dependent biological activity of allelochemics.Research supported by School of Natural Resources College of Agriculture and Life Sciences, University of Wisconsin-Madison and School of Forestry, Northern Arizona Univeristy under grants from the McIntire-Stennis Program.