The Leadership Teachers Want from Principals – Transformational

The data shared in this paper is part a preliminary study.  A more detailed and robust analysis of data will be conducted later.  From a randomly generated sample of 135 public schools in the Province of Alberta, Canada 77 agreed to participate in a study on leadership attributes of principals.  Ten randomly selected teachers from each participating school were asked to complete the Multifactor Leadership Questionnaire (MLQ) (Bass & Avolio, 1995; 1997; 2000) for their respective principals.  Based on the MLQ results principals were stratified into categories as having high or low levels of transformational leadership qualities.  Ten teachers were then selected for in depth interviews.  For one of the qualitative components teachers from ten schools were selected of in-depth interviews.  Five of the teachers worked with principals that were characterized as highly transformational and five worked with teachers that were characterized as low in transformational leadership attributes (one subsequently withdrew from the study).  The data interpretation allowed for stating that teachers strongly preferred principal behaviors that aligned with selected aspects of transformational leadership

A Computational Model of Cellular Mechanisms of Temporal Coding in the Medial Geniculate Body (MGB)

Acoustic stimuli are often represented in the early auditory pathway as patterns of neural activity synchronized to time-varying features. This phase-locking predominates until the level of the medial geniculate body (MGB), where previous studies have identified two main, largely segregated response types: Stimulus-synchronized responses faithfully preserve the temporal coding from its afferent inputs, and Non-synchronized responses, which are not phase locked to the inputs, represent changes in temporal modulation by a rate code. The cellular mechanisms underlying this transformation from phase-locked to rate code are not well understood. We use a computational model of a MGB thalamocortical neuron to test the hypothesis that these response classes arise from inferior colliculus (IC) excitatory afferents with divergent properties similar to those observed in brain slice studies. Large-conductance inputs exhibiting synaptic depression preserved input synchrony as short as 12.5 ms interclick intervals, while maintaining low firing rates and low-pass filtering responses. By contrast, small-conductance inputs with Mixed plasticity (depression of AMPA-receptor component and facilitation of NMDA-receptor component) desynchronized afferent inputs, generated a click-rate dependent increase in firing rate, and high-pass filtered the inputs. Synaptic inputs with facilitation often permitted band-pass synchrony along with band-pass rate tuning. These responses could be tuned by changes in membrane potential, strength of the NMDA component, and characteristics of synaptic plasticity. These results demonstrate how the same synchronized input spike trains from the inferior colliculus can be transformed into different representations of temporal modulation by divergent synaptic properties

Wake interaction and power production of variable height model wind farms

Understanding wake dynamics is an ongoing research topic in wind energy, since wakes have considerable effects on the power production when wind turbines are placed in a wind farm. Wind tunnel experiments have been conducted to study the wake to wake interaction in a model wind farm in tandem with measurements of the extracted power. The aim is to investigate how alternating mast height influences the interaction of the wakes and the power production. Via the use of stereo-particle image velocimetry, the flow field was obtained in the first and last rows of the wind turbine array as a basis of comparison. It was found that downstream of the exit row wind turbine, the power was increased by 25% in the case of a staggered height configuration. This is partly due to the fact that the taller turbines reach into a flow area with a softened velocity gradient. Another aspect is that the wake downstream of a tall wind turbine to some extent passes above the standard height wind turbine. Overall the experiments show that the velocity field downstream of the exit row changes considerably when the mast height is alternating

Investigating the Accuracy of One-Dimensional Volcanic Plume Models using Laboratory Experiments and Field Data

During volcanic eruptions, model predictions of plume height are limited by the accuracy of entrainment coefficients used in many plume models. Typically, two parameters are used, and , which relate the entrained air speed to the jet speed in the axial and cross-flow directions, respectively. To improve estimates of these parameters, wind tunnel experiments have been conducted for a range of cross-wind velocities and turbulence conditions. Measurements are compared directly to computations from the 1-D plume model, Plumeria, in the near-field, bending region of the jet. Entrainment coefficients are determined through regression analysis, demonstrating optimal combinations of effective and values. For turbulent conditions, all wind speeds overlapped at a single combination, = 0.06 and = 0.46, each of which are slightly reduced from standard values. Refined coefficients were used to model plume heights for 20 historical eruptions. Model accuracy improves modestly in most cases, agreeing to within 3 km with observed plume heights. For weak eruptions, uncertainty in field measurements can outweigh the effects of these refinements, illustrating the challenge of applying plume models in practice

A genome wide association study for backfat thickness in Italian Large White pigs highlights new regions affecting fat deposition including neuronal genes.

BACKGROUND: Carcass fatness is an important trait in most pig breeding programs. Following market requests, breeding plans for fresh pork consumption are usually designed to reduce carcass fat content and increase lean meat deposition. However, the Italian pig industry is mainly devoted to the production of Protected Designation of Origin dry cured hams: pigs are slaughtered at around 160 kg of live weight and the breeding goal aims at maintaining fat coverage, measured as backfat thickness to avoid excessive desiccation of the hams. This objective has shaped the genetic pool of Italian heavy pig breeds for a few decades. In this study we applied a selective genotyping approach within a population of ~ 12,000 performance tested Italian Large White pigs. Within this population, we selectively genotyped 304 pigs with extreme and divergent backfat thickness estimated breeding value by the Illumina PorcineSNP60 BeadChip and performed a genome wide association study to identify loci associated to this trait. RESULTS: We identified 4 single nucleotide polymorphisms with P 645.0E-07 and additional 119 ones with 5.0E-07<P 645.0E-05. These markers were located throughout all chromosomes. The largest numbers were found on porcine chromosomes 6 and 9 (n=15), 4 (n=13), and 7 (n=12) while the most significant marker was located on chromosome 18. Twenty-two single nucleotide polymorphisms were in intronic regions of genes already recognized by the Pre-Ensembl Sscrofa10.2 assembly. Gene Ontology analysis indicated an enrichment of Gene Ontology terms associated with nervous system development and regulation in concordance with results of large genome wide association studies for human obesity. CONCLUSIONS: Further investigations are needed to evaluate the effects of the identified single nucleotide polymorphisms associated with backfat thickness on other traits as a pre-requisite for practical applications in breeding programs. Reported results could improve our understanding of the biology of fat metabolism and deposition that could also be relevant for other mammalian species including humans, confirming the role of neuronal genes on obesity

Janus kinase (JAK) 2 V617F mutation as the cause of primary thrombocythemia in acromegaly with severe visceromegaly and divergence between growth hormone and insulin-like growth factor-1 concentrations during the follow-up: causal or casual association?

OBJECTIVE: An increased prevalence of hematological abnormalities is reported in acromegaly, but to date no reports about the presence of the Janus Kinase (JAK) 2 mutation in acromegalic patients have been described. DESIGN: We report the complex clinical presentation of the unique case, never described, of acromegaly due to GH-secreting pituitary adenoma associated with JAK2 V617F mutation. RESULTS: The patient shows primary thrombocythemia and myelofibrosis, due to JAK2 V617F mutation, severe visceromegaly and a peculiar clinical course of the disease characterized by discrepant values of GH and IGF-1 during somatostatin analog (SA) treatment despite a significant reduction in pituitary adenoma size and therapeutic resistance both to SA and pegvisomant. CONCLUSIONS: The presence of JAK2 V617F mutation is a cause of primary thrombocythemia and myelofibrosis in acromegaly. In this patient, a peculiar clinical course of acromegaly was observed, with the difficulty in controlling the disease. More data, on a larger cohort of patients, could clarify whether JAK2 V617F mutation has a serious impact on the clinical features and course of acromegaly.OBJECTIVE: An increased prevalence of hematological abnormalities is reported in acromegaly, but to date no reports about the presence of the Janus Kinase (JAK) 2 mutation in acromegalic patients have been described. DESIGN: We report the complex clinical presentation of the unique case, never described, of acromegaly due to GH-secreting pituitary adenoma associated with JAK2 V617F mutation. RESULTS: The patient shows primary thrombocythemia and myelofibrosis, due to JAK2 V617F mutation, severe visceromegaly and a peculiar clinical course of the disease characterized by discrepant values of GH and IGF-1 during somatostatin analog (SA) treatment despite a significant reduction in pituitary adenoma size and therapeutic resistance both to SA and pegvisomant. CONCLUSIONS: The presence of JAK2 V617F mutation is a cause of primary thrombocythemia and myelofibrosis in acromegaly. In this patient, a peculiar clinical course of acromegaly was observed, with the difficulty in controlling the disease. More data, on a larger cohort of patients, could clarify whether JAK2 V617F mutation has a serious impact on the clinical features and course of acromegaly

The Role of Surface Vorticity during Unsteady Separation

Unsteady flow separation in rotationally augmented flow fields plays a significant role in a variety of fundamental flows. Through the use of time-resolved particle image velocimetry, vorticity accumulation and vortex shedding during unsteady separation over a three-dimensional airfoil are examined. The results of the study describe the critical role of surface vorticity accumulation during unsteady separation and reattachment. Through evaluation of the unsteady characteristics of the shear layer, it is demonstrated that the buildup and shedding of surface vorticity directly influence the dynamic changes of the separation point location. The quantitative characterization of surface vorticity and shear layer stability enables improved aerodynamic designs and has a broad impact within the field of unsteady fluid dynamics

Fully 3D GPU PET reconstruction

Fully 3D iterative tomographic image reconstruction is computationally very demanding. Graphics Processing Unit(GPU) has be enproposed formany years as potential accelerators incomplex scientific problems, but it has not be enuseduntil there cent advances in the programmability of GPU sthat the best available reconstruction code shave started tobe implemented toberunon GPUs. This work presents a GPU based fully 3D PET iterative reconstruction sofware. This new code may reconstruct sinogram data from several commercially available PET scanners. The most important and time consuming part soft he code,the forward and backward projection operations, arebasedonan accurate model of the scanner obtained with the MonteCarlo code PeneloPET and they have been massively parallelize don the GPU.For the PET scanners considered, the GPU based code is more than 70 times faster than asimilar code running on a single core of a fast CPU, obtainingin both cases the same images. The code has been designed to be easily adapted to reconstruct sinograms from any other PET scanner, including scanner prototypes.This work has been supported by MEC(FPA200762216), UCM (Grupos UCM,910059), CPAN(Consolider Ingenio 2010) CSPD 200700042,the RECAVARETIC network, ARTEMISS2009/ DPI 1802, European Regional Development,ENTEPRASE grant, PSE 30000020095 and TEC20080675C0201, Ministerio de Ciencia e Innovación, Spanish Government.Publicad