The logic of organizational markets: thinking through resource partitioning theory

Resource partitioning theory claims that Increasing concentration enhances the life chances of specialist organizations. We systemati- cally think through this theory,specify implicit background assump- tions,sharpen concepts,and rigorously check the theory s logic.As a result,we increase the theory s explanatory power,and claim contrary to received opinion that under certain eneral conditions, resource partitioning and the proliferation of specialists can take place independently of organizational mass and relative size effects, size localized competition,diversifying consumer tastes, increasing number of dimensions of the resource space,and changing niche widths. Our analysis makes furthermore clear that specialist and generalist strategies are asymmetric, and shows that not concentration enhances the life chances of specialists but economies of scale instead.Under the conditions explicated,we argue that if scale economies come to dominate,the number of organizations in the population increases, regardless of the incumbents sizes.

Density results for automorphic forms on Hilbert modular groups

We give density results for automorphic representations of Hilbert modular groups. In particular, we show that there are infinitely many automorphic representations that have a prescribed discrete series factor at some (but not all) real places.Comment: 35 pages, LaTe

Mixed state Hall effect in the multiphase superconductors

Hall effect below Tc in multiphase superconductors has been studied on Bi-based superconductors. Samples with different relative content of 2212 and 2223 phase have been prepared. The phase content has been verified by X-ray diffraction. Results show that while resistance and ac susceptibility is almost insensitive to the content of 2212 phase, the qualitative behavior of the Hall resistance is strongly influenced by the presence of both phases. Theoretical calculation of Hall resistance has been made based on effective medium approximation and compared with experimental results.Comment: 7 pages, 7 figure

Validation of the Dutch Freiburg mindfulness inventory in patients with medical illness

Most validation studies of the Freiburg Mindfulness Inventory (FMI) involved healthy subjects. Validation in patients who suffer from a life-threatening medical illness is needed, to investigate the FMI’s validity in medical psychology research and practice. Psychometric properties of the Dutch FMI were examined in two patient groups of two different studies: (Sample 1) cardiac patients (n = 114, M age = 56 ± 7 years, 18% women) and (Sample 2) severely fatigued cancer survivors (n = 158, M age = 50 ± 10 years, 77% women). Confirmatory factor analysis (studied only in Sample 2) provided good fit for the two-factor solution (Acceptance and Presence), while the one-factor solution provided suboptimal fit indices. Internal consistency was good for the whole scale in both samples (Sample 1 α = .827 and Sample 2 α = .851). The two-factor model showed acceptable to good internal consistency in Sample 2 (Presence: α = .823; Acceptance α = .744), but poor to acceptable in Sample 1 (Presence subscale: α = .577, Acceptance subscale: α = .791). Clinical sensitivity was supported in both samples, and construct validity (studied only in Sample 1) was acceptable. The Dutch FMI is an acceptable instrument to measure mindfulness in patients who experienced a life-threatening illness in a Dutch-speaking populatio

Optical conductivity of a granular metal at not very low temperatures

We study the finite-temperature optical conductivity, sigma(omega,T), of a granular metal using a simple model consisting of a array of spherical metallic grains. It is necessary to include quantum tunneling and Coulomb blockade effects to obtain the correct temperature dependence of sigma(omega, T), and to consider polarization oscillations to obtain the correct frequency dependence. We have therefore generalized the Ambegaokar-Eckern-Schoen (AES) model for granular metals to obtain an effective field theory incorporating the polarization fluctuations of the individual metallic grains. In contrast to the DC conductivity, which is determined by inter-grain charge transfer and obeys an Arrhenius law at low temperature, the AC conductivity is dominated by a resonance peak for intra-grain polarization oscillations, which has a power-law tail at low frequencies. More importantly, although the resonance frequency agrees with the classical prediction, the resonance width depends on intergrain quantum tunneling and Coulomb blockade parameters, in addition to the classical Drude relaxation within the grain. This additional damping is due to inelastic cotunneling of polarization fluctuations to neighbouring grains and it qualitatively differs from the DC conductivity in its temperature dependence quite unlike the expectation from Drude theory.Comment: Added figures, published version, 16 pages, REVTe

The course of depressive symptoms and prescribing patterns of antidepressants in schizophrenia in a one-year follow-up study

AbstractBackgroundAntidepressants are frequently prescribed in patients with psychotic disorders, but little is known about their effects in routine clinical practice. The objective was to investigate the prescribing patterns of antidepressants in relation to the course of depressive symptoms in patients with psychotic disorders.MethodsA cohort of 214 Dutch patients with psychotic disorders received two assessments of somatic and psychiatric health, including a clinician-rated screening for depressive symptoms, as part of annual routine outcome monitoring.ResultsDepressive symptoms were prevalent among 43% (93) of the patients. Antidepressants were prescribed for 40% (86) of the patients and the majority 83% (71) continued this therapy after one year. Multivariable analysis showed that patients with more severe psychopathology had a higher risk to develop depressive symptoms the following year (OR [95% CI]=0.953 [0.912–0.995]). For patients with depressive symptoms at baseline, polypharmacy was a potential risk factor to keep having depressive symptoms (OR [95% CI]=1.593 [1.123–2.261]). Antidepressant use was not an independent predictor in both analyses.ConclusionsRoutine outcome monitoring in patients with psychotic disorders revealed a high prevalence of depressive symptoms. Antidepressants were frequently prescribed and continued in routine clinical practice

Cost-effectiveness and budget impact of a lifestyle intervention to improve cardiometabolic health in patients with severe mental illness

Introduction: This study assessed the cost-effectiveness and budget impact of a lifestyle intervention to improve cardiometabolic health in severe mentally ill (SMI) patients in the LION trial.Methods: Patients (n = 244) were randomized to receive either care-as-usual or a lifestyle intervention in which mental health nurses coached patients in changing their lifestyle by using a web tool. Costs and quality of life were assessed at baseline and at 6 and 12 months. Incremental costs per centimeter waist circumference (WC) lost and per Quality-Adjusted Life Year (QALY) gained were assessed. Budget impact was estimated based on three intervention-uptake scenarios using a societal and a third-party payer perspective.Results: Costs and reduction in WC were higher in the intervention (n = 114) than in the control (n = 94) group after 12 months, although not statistically significant, resulting in (sic)1,370 per cm WC lost. QALYs did not differ between the groups, resulting in a low probability of the intervention being cost-effective in cost/QALY gained. The budget impact analysis showed that for a reasonable participation of 43%, total costs were around (sic)81 million over 5 years, or on average (sic)16 million annually (societal perspective).Conclusions: The intervention is not cost-effective at 12 months and the budget impact over 5 years is substantial. Possibly, 12 months was too short to implement the intervention, improve cardiometabolic health, and reduce care costs. Therefore, the incentive for this intervention cannot be found in short-term financial advantages. However, there may be benefits associated with lifestyle interventions in the long term that remain unclear.</p

Modularity in signaling systems

Modularity is a property by which the behavior of a system does not change upon interconnection. It is crucial for understanding the behavior of a complex system from the behavior of the composing subsystems. Whether modularity holds in biology is an intriguing and largely debated question. In this paper, we discuss this question taking a control system theory view and focusing on signaling systems. In particular, we argue that, despite signaling systems being constituted of structural modules, such as covalent modification cycles, modularity does not hold in general. As in any engineering system, impedance-like effects, called retroactivity, appear at interconnections and alter the behavior of connected modules. We further argue that while signaling systems have evolved sophisticated ways to counter-act retroactivity and enforce modularity, retroactivity may also be exploited to finely control the information processing of signaling pathways. Testable predictions and experimental evidence are discussed with their implications