Not So Lonely At The Top?: An Exploratory Study Of The Multiple Commitments Of Aspiring Leaders

Leadership is often viewed as a lonely endeavor, as this quote exemplifies. Leaders are frequently perceived as standing “alone” at the top of the hierarchy. Drive and sustained commitment have been linked to the attainment of leadership positions (McClelland & Boyatzis, 1982), findings that are corroborated by the many public and private sector leaders who have described the years of intense work, perseverance, and sacrifice that led to their success. Traveling the path to career success and leadership positions can come at the expense of developing rewarding relationships with friends and family (e.g., Hewlett, 2002)

Negative Outgroup Leader Actions Increase Liking for Ingroup Leaders: An Experimental Test of Intergroup Leader-Enhancement Effects

We conducted two studies to examine how information about outgroup leaders' negative actions affect ingroup leader favorability ratings. Study 1 found that people hold more favorable attitudes toward ingroup leaders (i.e. their own nation's leaders) when learning of negative actions of outgroup leaders (i.e. another nation's leaders). Study 2 replicated the finding, examining social identity strength as a moderator of this effect, and found that participants with strong national identification exhibit this intergroup leader-enhancement effect but participants with weak national identification do not. These data extend previous research on liking for leaders and are consistent with predictions derived from social identity theory. The implications of these findings for intergroup relations research and the psychological study of leadership are discussed

Formal and Informal Discrimination Against Women At Work: The Role of Gender Stereotypes

When asked to think about a hostile environment for women in the workplace, many of us would first envision overt instances of sexual harassment or blatant employment discrimination. These associations are certainly not astonishing: even in an age in which these behaviors are denounced and in large part illegal, such organizational misconduct seems almost commonplace. There have been many high-profile allegations of discrimination leveled against organizations within the last several years (Morris, Bonamici & Neering, 2005). For example, Morgan Stanley’s investment banking business recently paid out $54 million to over 300 female employees who claim to have been denied pay and promotions equal to those received by their male colleagues. Additionally, 1.6 million women who are currently, or were formerly, employed at Wal-Mart are eligible to participate in what is poised to become the largest-ever civil rights lawsuit: like the women of Morgan Stanley, they claim to have been victims of sex discrimination (Greenhouse, 2004). In fact, according to statistics from the Equal Employment Opportunity Commission, there has been no systematic decline over the last 12 years in the number of discrimination lawsuits filed, or the amount of monetary damages awarded to the plaintiffs of these suits (Equal Employment Opportunity Commission, 2004)

Shape-Memory Alloy Actuators for Small Satellites

A frequently‐used hold‐and‐release mechanism for spacecraft deployables is the “meltwire” or “burnwire”. Here an electrically resistive heating element melts through a fusible restraint to free some sliding, pivoting, or flexing element such as a hinged solar array, an instrument boom, or an antenna. The heating element is often a length of nichrome wire, but discrete electrical resistors, both surfacemount and through‐hole have also been used. Meltwire release mechanisms present a unique challenge for testing in that they cannot be reused; once melted, the fusible restraint must be replaced. Since this is often a laborious and time‐consuming task, the testing regime is often limited, particularly for small, low‐budget spacecraft. In addition, since the fusible restraint must be replaced after each use, the component that ultimately flies will be one that has not, itself, been tested. We have found that simple mechanisms actuated by Shape Memory Alloy (SMA) devices are an effective alternative to meltwires for small spacecraft applications. In contrast to meltwires, these mechanisms are easily resettable, enabling a low‐cost but robust test campaign to ensure operational reliability. In each case the heart of the device is a length of nitinol wire, nitinol being a nickel titanium alloy that can be configured to contract 3 to 4% on heating. Heating is accomplished by passing an electrical current through the wire. The resulting contraction exerts a force that can be used to move a structure attached to the wire, so implementation of SMA‐actuated release mechanisms revolves around design of mechanisms that can be operated through a simple pull force. When the nitinol returns to its original temperature, it can be stretched mechanically to its original dimension with essentially no degradation of its properties (provided it has not been overheated), allowing the mechanism to be reset and ready for the next actuation. Many of the features of SMA wire actuators are particularly suited (but not limited to) to the kinds of one‐time‐use mechanisms found on satellites. They are light, simple, and easily tested and reset. They present no magnetic signature when not energized. They can also be built into more complex devices that have multiple discrete positions and can even be used to produce or control a motor. In addition, they are clean; they can often be designed without greases or other lubricants that could pose a contamination risk, and they produce no debris when actuated. While there are many reasons to consider SMA wire actuators, prudence demands an understanding of their limitations, particularly with respect to actuation speed, electrical efficiency, longevity, and force limitations. Another key consideration is that the performance of SMA actuators can be severely degraded by overheating. As such, the thermal design must take into account operations in both air and vacuum, and particular care must be taken to ensure that vacuum test procedures do not result in unacceptable thermal stresses. SMA actuators have flown and operated successfully on six spacecraft in the AeroCube series, and these actuators are designed into a number of upcoming missions. This paper will review design, assembly, and testing techniques and present several case studies from recent AeroCube flights

Progress toward developing the TMT adaptive optical systems and their components

Atmospheric turbulence compensation via adaptive optics (AO) will be essential for achieving most objectives of the TMT science case. The performance requirements for the initial implementation of the observatory's facility AO system include diffraction-limited performance in the near IR with 50 per cent sky coverage at the galactic pole. This capability will be achieved via an order 60x60 multi-conjugate AO system (NFIRAOS) with two deformable mirrors optically conjugate to ranges of 0 and 12 km, six high-order wavefront sensors observing laser guide stars in the mesospheric sodium layer, and up to three low-order, IR, natural guide star wavefront sensors located within each client instrument. The associated laser guide star facility (LGSF) will consist of 3 50W class, solid state, sum frequency lasers, conventional beam transport optics, and a launch telescope located behind the TMT secondary mirror. In this paper, we report on the progress made in designing, modeling, and validating these systems and their components over the last two years. This includes work on the overall layout and detailed opto-mechanical designs of NFIRAOS and the LGSF; reliable wavefront sensing methods for use with elongated and time-varying sodium laser guide stars; developing and validating a robust tip/tilt control architecture and its components; computationally efficient algorithms for very high order wavefront control; detailed AO system modeling and performance optimization incorporating all of these effects; and a range of supporting lab/field tests and component prototyping activities at TMT partners. Further details may be found in the additional papers on each of the above topics

Progress toward developing the TMT adaptive optical systems and their components

Atmospheric turbulence compensation via adaptive optics (AO) will be essential for achieving most objectives of the TMT science case. The performance requirements for the initial implementation of the observatory's facility AO system include diffraction-limited performance in the near IR with 50 per cent sky coverage at the galactic pole. This capability will be achieved via an order 60x60 multi-conjugate AO system (NFIRAOS) with two deformable mirrors optically conjugate to ranges of 0 and 12 km, six high-order wavefront sensors observing laser guide stars in the mesospheric sodium layer, and up to three low-order, IR, natural guide star wavefront sensors located within each client instrument. The associated laser guide star facility (LGSF) will consist of 3 50W class, solid state, sum frequency lasers, conventional beam transport optics, and a launch telescope located behind the TMT secondary mirror. In this paper, we report on the progress made in designing, modeling, and validating these systems and their components over the last two years. This includes work on the overall layout and detailed opto-mechanical designs of NFIRAOS and the LGSF; reliable wavefront sensing methods for use with elongated and time-varying sodium laser guide stars; developing and validating a robust tip/tilt control architecture and its components; computationally efficient algorithms for very high order wavefront control; detailed AO system modeling and performance optimization incorporating all of these effects; and a range of supporting lab/field tests and component prototyping activities at TMT partners. Further details may be found in the additional papers on each of the above topics

Gastroesophageal Reflux and Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) and Gastroesophageal reflux disease (GERD) commonly co-exist. Pathophysiological mechanisms causing IPF are still not well understood, and GERD has been implicated in both as a probable causative and disease-promoting entity. Although not conclusively proven, this relationship has been the subject of several studies, including therapeutic interventions aimed at treating GERD and its resultant effect on IPF and related outcomes. Our review aims to present the current concepts and understanding of these two disease processes, which are multifaceted. Their complex interaction includes epidemiology, pathophysiology, diagnosis, treatment, review of research studies conducted to date, and future directions for research

Increased Skeletal Muscle 11βHSD1 mRNA Is Associated with Lower Muscle Strength in Ageing

Background: Sarcopenia, the loss of muscle mass and function with age, is associated with increased morbidity and mortality. Current understanding of the underlying mechanisms is limited. Glucocorticoids (GC) in excess cause muscle weakness and atrophy. We hypothesized that GC may contribute to sarcopenia through elevated circulating levels or increased glucocorticoid receptor (GR) signaling by increased expression of either GR or the GC-amplifying enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11βHSD1) in muscle. Methods: There were 82 participants; group 1 comprised 33 older men (mean age 70.2years, SD 4.4) and 19 younger men (22.2years, 1.7) and group 2 comprised 16 older men (79.1years, 3.4) and 14 older women (80.1years, 3.7). We measured muscle strength, mid-thigh cross-sectional area, fasting morning plasma cortisol, quadriceps muscle GR and 11βHSD1 mRNA, and urinary glucocorticoid metabolites. Data were analysed using multiple linear regression adjusting for age, gender and body size. Results: Muscle strength and size were not associated with plasma cortisol, total urinary glucocorticoids or the ratio of urinary 5β-tetrahydrocortisol +5α-tetrahydrocortisol to tetrahydrocortisone (an index of systemic 11βHSD activity). Muscle strength was associated with 11βHSD1 mRNA levels (β -0.35, p = 0.04), but GR mRNA levels were not significantly associated with muscle strength or size. Conclusion: Although circulating levels of GC are not associated with muscle strength or size in either gender, increased cortisol generation within muscle by 11βHSD1 may contribute to loss of muscle strength with age, a key component of sarcopenia. Inhibition of 11βHSD1 may have therapeutic potential in sarcopenia