The Relationships Among Gender, Work Experience, and Leadership Experience in Transformational Leadership

Transformational leadership is an organizational leadership theory centered around the ability to inspire and motivate followers to achieve results greater than originally planned and for internal reward The investigation into transformational leadership began in the mid-1980s with a number of influential publications by Bass (1985), Bennis and Nanus (1985), Kouzes and Posner (1987) and Tichy and Devanna (1986). In the 1980s, the study of transformational leadership was focused on case-based research (Conger, 1999). By late 1990s, a substantial body of empirical investigations on transformational leadership had been conducted

Distinguishing impurity concentrations in GaAs and AlGaAs, using very shallow undoped heterostructures

We demonstrate a method of making a very shallow, gateable, undoped 2-dimensional electron gas. We have developed a method of making very low resistivity contacts to these structures and systematically studied the evolution of the mobility as a function of the depth of the 2DEG (from 300nm to 30nm). We demonstrate a way of extracting quantitative information about the background impurity concentration in GaAs and AlGaAs, the interface roughness and the charge in the surface states from the data. This information is very useful from the perspective of molecular beam epitaxy (MBE) growth. It is difficult to fabricate such shallow high-mobility 2DEGs using modulation doping due to the need to have a large enough spacer layer to reduce scattering and switching noise from remote ionsied dopants.Comment: 4 pages, 5 eps figure

The Ultraluminous X-ray Sources near the Center of M82

We report the identification of a recurrent ultraluminous X-ray source (ULX), a highly absorbed X-ray source (possibly a background AGN), and a young supernova remnant near the center of the starburst galaxy M82. From a series of Chandra observations taken from 1999 to 2005, we found that the transient ULX first appeared in 1999 October. The source turned off in 2000 January, but later reappeared and has been active since then. The X-ray luminosity of this source varies from below the detection level (~2.5e38 erg/s) to its active state in between ~7e39 erg/s and 1.3e40 erg/s (in the 0.5-10 keV energy band) and shows unusual spectral changes. The X-ray spectra of some Chandra observations are best fitted with an absorbed power-law model with photon index ranging from 1.3 to 1.7. These spectra are similar to those of Galactic black hole binary candidates seen in the low/hard state except that a very hard spectrum was seen in one of the observations. By comparing with near infrared images taken with the Hubble Space Telescope, the ULX is found to be located within a young star cluster. Radio imaging indicates that it is associated with a H II region. We suggest that the ULX is likely to be a > 100 solar mass intermediate-mass black hole in the low/hard state. In addition to the transient ULX, we also found a highly absorbed hard X-ray source which is likely to be an AGN and an ultraluminous X-ray emitting young supernova remnant which may be related to a 100-year old gamma-ray burst event, within 2 arcsec of the transient ULX.Comment: 9 pages, 8 figures. Accepted for publication in Ap

IL-33 ameliorates Alzheimer’s disease-like pathology and cognitive decline

Alzheimer’s disease (AD) is a devastating condition with no known effective treatment. AD is characterized by memory loss as well as impaired locomotor ability, reasoning, and judgment. Emerging evidence suggests that the innate immune response plays a major role in the pathogenesis of AD. In AD, the accumulation of β-amyloid (Aβ) in the brain perturbs physiological functions of the brain, including synaptic and neuronal dysfunction, microglial activation, and neuronal loss. Serum levels of soluble ST2 (sST2), a decoy receptor for interleukin (IL)-33, increase in patients with mild cognitive impairment, suggesting that impaired IL-33/ST2 signaling may contribute to the pathogenesis of AD. Therefore, we investigated the potential therapeutic role of IL-33 in AD, using transgenic mouse models. Here we report that IL-33 administration reverses synaptic plasticity impairment and memory deficits in APP/PS1 mice. IL-33 administration reduces soluble Aβ levels and amyloid plaque deposition by promoting the recruitment and Aβ phagocytic activity of microglia; this is mediated by ST2/p38 signaling activation. Furthermore, IL-33 injection modulates the innate immune response by polarizing microglia/macrophages toward an antiinflammatory phenotype and reducing the expression of proinflammatory genes, including IL-1β, IL-6, and NLRP3, in the cortices of APP/PS1 mice. Collectively, our results demonstrate a potential therapeutic role for IL-33 in AD

Preventing and Treating Type 2 Diabetes Through a Physically Active Lifestyle

By the late 1960s, the increasing number of type 2 diabetic cases in children and adolescents rapidly presented a signifi cant public health issue recognized by the American Diabetes Association (2000). Since then, the prevalence of pediatric type 2 diabetes appears to be on the rise not only in the United States but all around the world (Gungor et al., 2005). In the United States, an increase from fewer than four percent to more than 50 percent of new cases of type 2 diabetes in the pediatric population was reported between the years of 1982 and 1998 (American Diabetes Association, 2000). An increasing percentage of pediatric cases of newly diagnosed type 2 diabetes were also reported in population-based data (Gungor et al., 2005). Therefore, the purpose of this article is to discuss how regular physical activity can help to prevent and treat type 2 diabetes

Inhibition of purple acid phosphatase with a-alkoxynaphthylmethylphosphonic acids

Purple acid phosphatases (PAPs) are binuclear hydrolases that catalyse the hydrolysis of a range of phosphorylated substrates. Human PAP is a major histochemical marker for the diagnosis of osteoporosis. In patients suffering from this disorder, PAP activity contributes to increased bone resorption and, therefore, human PAP is a key target for the development of anti-osteoporotic drugs. This manuscript describes the design and synthesis of derivatives of 1-naphthylmethylphosphonic acids as inhibitors of PAP. The Ki values of these compounds are as low as 4 lM, the lowest reported to date for a PAP inhibitor

Crossover from Fermi liquid to Wigner molecule behavior in quantum dots

The crossover from weak to strong correlations in parabolic quantum dots at zero magnetic field is studied by numerically exact path-integral Monte Carlo simulations for up to eight electrons. By the use of a multilevel blocking algorithm, the simulations are carried out free of the fermion sign problem. We obtain a universal crossover only governed by the density parameter $r_s$. For $r_s>r_c$, the data are consistent with a Wigner molecule description, while for $r_s<r_c$, Fermi liquid behavior is recovered. The crossover value $r_c \approx 4$ is surprisingly small.Comment: 4 pages RevTeX, 3 figures, corrected Tabl

AP-1 as a Regulator of MMP-13 in the Stromal Cell of Giant Cell Tumor of Bone

Matrix-metalloproteinase-13 (MMP-13) has been shown to be an important protease in inflammatory and neoplastic conditions of the skeletal system. In particular, the stromal cells of giant cell tumor of bone (GCT) express very high levels of MMP-13 in response to the cytokine-rich environment of the tumor. We have previously shown that MMP-13 expression in these cells is regulated, at least in part, by the RUNX2 transcription factor. In the current study, we identify the expression of the c-Fos and c-Jun elements of the AP-1 transcription factor in these cells by protein screening assays and real-time PCR. We then used siRNA gene knockdown to determine that these elements, in particular c-Jun, are upstream regulators of MMP-13 expression and activity in GCT stromal cells. We conclude that there was no synergy found between RUNX2 and AP-1 in the regulation of the MMP13 expression and that these transcription factors may be independently regulated in these cells