Variability of developmental timings of the knee in young American children as assessed through Pyle and Hoerr's radiographic atlas

This study examines the accuracy of the Pyle and Hoerr radiographic atlas technique in an effort to document the extent of normal variation associated with developmental timings in the knee for purposes of age estimation. The atlas has been previously tested; however, accuracy rates were produced from a dataset, which spread in age from mostly 7–16 years. This study took a closer look at the younger age groups, examining radiographs from 297 children (147 female and 150 male) from birth to 6 years. Standard deviations representing the difference between the skeletal and chronological age were calculated according to two groupings. Each group represents episodes, or time periods, of differential developmental rates as expressed through the number of plates within the atlas dedicated to documenting each year of life. The beginning year of life is characterized by the most rapid of development as represented by the numerous image plates used to depict this time period. Individuals assigned to plates with a skeletal age between birth and 1 year were grouped collectively to document the variation associated with such rapidly changing morphology (SD = 2.5 months in female children; 2.3 months in male children). Years 1–3.8 years (female) and 1–4.5 years (male) were represented by two or three images within the atlas, and therefore, individuals assigned to plates with a skeletal age falling within this range were placed within a second grouping (SD = 5.2 months in female children; 7.0 months in male children). As expected, variation was observed to decrease as developmental processes accelerated in the younger children. The newly calculated standard deviations offer tighter predictions for estimating age in young children while at the same time maintaining an acceptable width that accounts for normal variation in developmental timings.</p

Ready4Work In Brief Interim Outcomes Are In: Recidivism at Half the National Average

This issue of "P/PV In Brief' reviews interim outcomes from the Ready4Work prisoner reentry initiative. Funded by the US Department of Labor and the Annie E. Casey and Ford foundations, Ready4Work is a three-year national demonstration project designed to address the needs of the growing ex-prisoner population and to test the capacity of community- and faith-based organizations to meet those needs. Ready4Work programs are providing employment services, case management and mentoring in 11 adult sites around the country (data from seven juvenile sites are being analyzed separately). Interim outcomes from the initiative are extremely encouraging, with almost 60 percent of participants becoming employed and the majority of them staying employed for three or more consecutive months. Even more striking, recidivism rates for Ready4Work participants are considerably lower than those reported by the Bureau of Justice Statistics for a similar population

Targeting Glycolysis with Epigallocatechin-3-Gallate Enhances the Efficacy of Chemotherapeutics in Pancreatic Cancer Cells and Xenografts.

Pancreatic cancer is a complex disease, in need of new therapeutic approaches. In this study, we explored the effect and mechanism of action of epigallocatechin-3-gallate (EGCG), a major polyphenol in green tea, alone and in combination with current chemotherapeutics on pancreatic cancer cell growth, focusing on glycolysis metabolism. Moreover, we investigated whether EGCG's effect is dependent on its ability to induce reactive oxygen species (ROS). EGCG reduced pancreatic cancer cell growth in a concentration-dependent manner and the growth inhibition effect was further enhanced under glucose deprivation conditions. Mechanistically, EGCG induced ROS levels concentration-dependently. EGCG affected glycolysis by suppressing the extracellular acidification rate through the reduction of the activity and levels of the glycolytic enzymes phosphofructokinase and pyruvate kinase. Cotreatment with catalase abrogated EGCG's effect on phosphofructokinase and pyruvate kinase. Furthermore, EGCG sensitized gemcitabine to inhibit pancreatic cancer cell growth in vitro and in vivo. EGCG and gemcitabine, given alone, reduced pancreatic tumor xenograft growth by 40% and 52%, respectively, whereas the EGCG/gemcitabine combination reduced tumor growth by 67%. EGCG enhanced gemcitabine's effect on apoptosis, cell proliferation, cell cycle and further suppressed phosphofructokinase and pyruvate kinase levels. In conclusion, EGCG is a strong combination partner of gemcitabine reducing pancreatic cancer cell growth by suppressing glycolysis

The Perils of Positivity

The passion and productivity that characterizes research on positive organizational behavior (POB) is impressive. Yet POB research is accumulating so rapidly that it may exceed what the field's conceptual, methodological, and ideological foundation can bear. I discuss here six concerns prompted by the articles in this special issue. These concerns are (1) the emphasis of positive organizational scholarship on individual-level phenomena, (12) the ahistorical character of POB research and writing, (3) the construct validity of key concepts, (4) over-reliance on a particular research strategy, (5) implicit acceptance of fundamental flaws in how work and organizations are designed, and (6) the seductiveness of new research paradigms.Psycholog

Teaching Leadership from a Communication Perspective

Interest in leadership has intensified during the past decade. This heightened interest in leadership appears to be encouraging communication departments to offer leadership coursework. This article provides a model for a communication-based course in leadership. A sample syllabus, information on preferred teaching methods, and instructional resources are presented

Asking the Right Questions About Leadership: Discussion and Conclusions

Five questions prompted by the articles in the American Psychologist special issue on leadership (January 2007, Vol. 62, No. 1) suggest some new directions for leadership research: (1) Not do leaders make a difference, but under what conditions does leadership matter? (2) Not what are the traits of leaders, but how do leaders' personal attributes interact with situational properties to shape outcomes? (3) Not do there exist common dimensions on which all leaders can be arrayed, but are good and poor leadership qualitatively different phenomena? (4) Not how do leaders and followers differ, but how can leadership models be reformulated so they treat all system members as both leaders and followers? (5) Not what should be taught in leadership courses, but how can leaders be helped to learn?Psycholog

Organizations in Changing Environments: The Case of East German Symphony Orchestras

Two periods of radical political-economic change in the former East Germany illuminate dynamics of organization-environment relationships that generally are hidden from view. Historical, qualitative, and survey data from a longitudinal comparative study of 78 orchestras in four nations show that the contexts of East German orchestras changed significantly when the socialist regime took power after World War II, and then again in 1990 when that regime fell. Socialist rule only modestly affected orchestras' institutional features, however; they continued to reflect centuries-old German musical traditions. The collapse of socialism in 1990, by contrast, provoked differentiation among orchestras-some adapted successfully to the new political-economic context, but others floundered. Successful adaptation was found to be a joint function of an orchestra's prior strength as an organization and the kinds of leadership initiatives taken by orchestra leaders and players. Overall, the findings suggest that the size and character of environmental effects depend on the degree to which contextual changes alter (a) the strength of the link between organizational actions and resources obtained (resource contingency) and (b) organizations' latitude to manage their own affairs (operational autonomy).Psycholog

Magnetic field topology of the RS CVn star II Pegasi

The dynamo processes in cool active stars generate complex magnetic fields responsible for prominent surface stellar activity and variability at different time scales. For a small number of cool stars magnetic field topologies were reconstructed from the time series of spectropolarimetric observations using the Zeeman Doppler imaging (ZDI) method. In this study we follow a long-term evolution of the magnetic field topology of the RS CVn binary star II Peg. We collected high-resolution circular polarisation observations of II Peg using the SOFIN spectropolarimeter at the Nordic Optical Telescope. These data cover 12 epochs spread over 7 years. A multi-line diagnostic technique in combination with a new ZDI code is applied to interpret these observations. Magnetic inversions using these data reveals evolving magnetic fields with typical local strengths of 0.5-1.0 kG and complex topologies. Despite using a self-consistent magnetic and temperature mapping technique, we do not find a clear correlation between magnetic and temperature features in the ZDI maps. Neither do we confirm the presence of persistent azimuthal field rings found in other RS CVn stars. Reconstruction of the magnetic field topology of II Peg reveals significant evolution of both the surface magnetic field structure and the extended magnetospheric field geometry. From 2004 to 2010 the total field energy drastically declined and the field became less axisymmetric. This also coincided with the transition from predominantly poloidal to mainly toroidal field topology. A qualitative comparison of the ZDI maps of II Peg with the prediction of dynamo theory suggests that the magnetic field in this star is produced mainly by the turbulent alpha^2 dynamo rather than the solar alphaOmega dynamo. Our results do not show a clear active longitude system, nor is there an evidence of the presence of an azimuthal dynamo wave.Comment: 20 pages, 10 figures; accepted for publication in Astronomy & Astrophysic