254,362 research outputs found
Detection of TMPRSS2 : ERG fusion gene in circulating prostate cancer cells
Creative Commons Attribution-NonCommercial-Share Alike 3.0 license (CC BY-NC SA)Aim: To investigate the existence of TMPRSS2:ERG fusion gene in circulating tumor cells (CTC) from prostate cancer patients and its potential in monitoring tumor metastasis. Methods: We analyzed the frequency of TMPRSS2: ERG and TMPRSS2:ETV1 transcripts in 27 prostate cancer biopsies from prostatectomies, and TMPRSS2:ERG transcripts in CTC isolated from 15 patients with advanced androgen independent disease using reverse transcription polymerase chain reaction (RT-PCR). Fluorescence in situ hybridization (FISH) was applied to analyze the genomic truncation of ERG, which is the result of TMPRSS2:ERG fusion in 10 of the 15 CTC samples. Results: TMPRSS2: ERG transcripts were found in 44% of our samples, but we did not detect expression of TMPRSS2:ETV1. Using FISH analysis we detected chromosomal rearrangements affecting the ERG gene in 6 of 10 CTC samples, including 1 case with associated TMPRSS2:ERG fusion at the primary site. However, TMPRSS2:ERG transcripts were not detected in any of the 15 CTC samples, including the 10 cases analyzed by FISH. Conclusion: Although further study is required to address the association between TMPRSS2:ERG fusion and prostate cancer metastasis, detection of genomic truncation of the ERG gene by FISH analysis could be useful for monitoring the appearance of CTC and the potential for prostate cancer metastasis.Peer reviewedFinal Published versio
Symmetry and Time Changed Brownian Motions
In this paper we examine which Brownian Subordination with drift exhibits the symmetry property introduced by Fajardo and Mordecki (2006b). We obtain that when the subordination results in a Lévy process, a necessary and sufficient condition for the symmetry to hold is that drift must be equal to -1/2.Time Changed, Subordination, Symmetry
Bayesian Factor Selection in Dynamic Term Structure Models
This paper discusses Bayesian procedures for factor selection in dynamic term structure models through simulation methods based on Markov Chain Monte Carlo. The number of factors, besides influencing the fitting and prediction of observed yields, is also relevant to features such as the imposition of no-arbitrage conditions. We present a methodology for selecting the best specification in the Nelson-Siegel class of models using Reversible Jump MCMC.Dynamic Term Structure Models, Model Selection, Reversible Jump MCMC
An Examination of the Demographic Antecedents and Job Outcomes of Participation in Employee Resource Groups (ERGs)
Employee resource groups (ERGs) are voluntary, employee-led groups formed in the workplace that focus on providing mutual support for members and that educate the organization about its members’ culture, identity, or experiences. The study’s purpose was to examine demographic antecedents and job outcomes associated with ERG participation. Specifically, this study examined gender identity and professional tenure as demographic antecedents of ERG participation and the relationship between ERG participation and employee outcomes, including job embeddedness and organizational commitment. Participants included 154 individuals employed at a technology company in the Northwestern United States who completed a survey regarding their personal characteristics and participation in ERGs as well as their commitment to and embeddedness within the organization. Results showed that female employees were more likely to become members of an ERG and to participate frequently. Additionally, frequent participation in ERG activities was associated with a stronger affective bond with the organization. Results also showed that professional tenure was not related to ERG membership or frequency of ERG participation. Finally, no relationship was found between frequent ERG participation and job embeddedness. Based on the findings of study, it is recommended that ERGs are properly funded and managed to allow for consistent participation by all employees and that organizations focus on intersectionality in their promotion of ERG events
Trust-Based Trade
There is substantially more trade within national borders than across borders. An important explanation for this fact is the weak enforcement of international contracts. We develop a model in which agents build reputations to overcome this institutional failure. The model describes the interplay between institutional quality, reputations and the dynamics of international trade. It also rationalizes several empirical regularities. We find that history matters for trade volumes, but that its effects vary with the institutional setting of the country. The same is true for the efficacy of trade liberalization programs. Moreover, while stricter enforcement of contracts enhances trade in the short run, it makes it harder for individual traders to develop good reputations. We show that this indirect negative effect may produce an "institutional trap": for sufficiently low initial levels of contract enforcement, a small tightening in enforcement reduces future trade flows. We find also that search frictions aggravate the problems created by weak enforceability of contracts, even if they impose no direct cost on agents, but that trade liberalization can mitigate these negative effects.International trade, Export dynamics, Contract enforcement, Reputation
Diabetes Alters Diurnal Rhythm of Electroretinogram in db/db Mice
Diabetic retinopathy (DR) is the most common complications of diabetes and a leading cause of blindness in the United States. The retinal neuronal changes precede the vascular dysfunction observed in DR. The electroretinogram (ERG) determines the electrical activity of retinal neural and non-neuronal cells. The retinal ERG amplitude is reduced gradually on the progression of DR to a more severe form. Circadian rhythms play an important role in the physiological function of the body. While ERG is known to exhibit a diurnal rhythm, it is not known whether a progressive increase in the duration of diabetes affects the physiological rhythm of retinal ERG. To study this, we determined the ERG rhythm of db/db mice, an animal model of type 2 diabetes at 2, 4, and 6 months of diabetes under a regular light-dark cycle and constant dark. Our studies demonstrate that the diurnal rhythm of ERG amplitude for retinal a-wave and b-wave was altered in diabetes. The implicit time was increased in db/db mice while the oscillatory potential was reduced. Moreover, there was a progressive decline in an intrinsic rhythm of ERG upon an increase in the duration of diabetes. In conclusion, our studies provide novel insights into the pathogenic mechanism of DR by showing an altered circadian rhythm of the ERG
The Evolution of International Output Differences (1960-2000): From Factors to Productivity
This article presents a group of exercises of level and growth decomposition of output per worker using cross-country data from 1960 to 2000. It is shown that at least until 1975 factors of production (capital and education) were the main source of output dispersion across economies and that productivity variance was considerably smaller than in later years. Only after this date did the prominence of productivity start to show up in the data, as the majority of the literature has found. The growth decomposition exercises showed that the reversal of relative importance of productivity vis-a-vis factors is explained by the very good (bad) performance of productivity of fast- (slow-) growing economies. Although growth in the period, is on average, is mostly due to factor accumulation, its variance is explained by productivity.Cross-Country Income Inequality, Development, Total Factor Productivity, Aggregate Production Function, Growth Decomposition
Skinning the Cat: Education Distribution, Changes in the School Premium and Earnings Inequality
This paper applies the procedure in JUHN ET ALL (1993) to decompose changes in income inequality over time in terms of education-related causal factors: school premiums, educational distribution and residual changes. The main conclusion is that reductions in the school premiums have systematically had a negative impact on income inequality during the last twenty years. At the same time, education has become more unequally distributed for individuals below the median labor income level and more equally distributed for those above it. The combination of the two forces has reduced income dispersion for the top half of earners, and slightly increased it among the bottom half. This difference in trends of educational distribution lies behind an apparently stable profile of income inequality (considering the whole earnings distribution).
Ownership Structure and the Market for Corporate Control
We study the impact of the ownership structure of a corporation on the characteristics and efficiency of the market for corporate control. We adopt a general mechanism design approach, in which endogenous sources of inefficiency in the market, including adverse selection, moral hazard, budget balance and voluntary trading, may preclude the possibility of efficiently restructuring control and ownership. We identify necessary and sufficient conditions for an efficient market, and describe the characteristics of efficient restructuring mechanisms, when they exist. In efficient restructuring, corporations typically increase the number of shares of the incumbent manager when he remains in control, or give him a generous golden parachute when he is deposed. Corporations are also reluctant to assign full control and full ownership to a single stockholder, unless agency costs are severe. We characterize the set of ownership structures for which efficient restructuring is possible. While the distribution of ownership among the non-controlling shareholders is irrelevant, the level of initial managerial ownership is a central determinant of this set. Typically, efficient restructuring is easier to obtain for low levels of managerial ownership.ownership, corporate control, restructuring, mechanism design
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