High colloidal stability of gold nanorods coated with a peptide-ethylene glycol: Analysis by cyanide-mediated etching and nanoparticle tracking analysis

The stability of gold nanorods was assessed following coating with various charged or uncharged ligands, mostly peptides. Highly stable monodispersed gold nanorods were obtained by coating CTAB-stabilized gold nanorods with a pentapeptide with C-terminal ethylene glycol units (peptide-EG). UV-vis spectroscopy of these nanorods suspended in saline solutions indicated no signs of aggregation, and they were easily purified using size-exclusion chromatography. A more stringent measure of nanorod stability involved observing changes in the UV-vis absorbance of gold nanorods subjected to etching with cyanide. The max absorbance of peptide-EG coated nanorods red-shifted in etchant solution. The hypothesis that changes in the nanorod aspect ratio led to this red-shift was confirmed by TEM analysis, which showed pit formation along the transverse axis. The etching process was followed in solution using nanoparticle tracking analysis. The red-shift was shown to occur while the particles remained mono-dispersed, and so was not due to aggregation. Adding both etchant solution and peptide-EG to the nanorods was further shown to allow modulation of the max red-shift and increase the etchant resistance of peptide-EG nanorods. Thus, very stable gold nanorods can be produced using the peptide-EG coating approach and their optical properties modulated with etchant

Hopf algebras and Markov chains: Two examples and a theory

The operation of squaring (coproduct followed by product) in a combinatorial Hopf algebra is shown to induce a Markov chain in natural bases. Chains constructed in this way include widely studied methods of card shuffling, a natural "rock-breaking" process, and Markov chains on simplicial complexes. Many of these chains can be explictly diagonalized using the primitive elements of the algebra and the combinatorics of the free Lie algebra. For card shuffling, this gives an explicit description of the eigenvectors. For rock-breaking, an explicit description of the quasi-stationary distribution and sharp rates to absorption follow.Comment: 51 pages, 17 figures. (Typographical errors corrected. Further fixes will only appear on the version on Amy Pang's website, the arXiv version will not be updated.

Judging the impact of leadership-development activities on school practice

The nature and effectiveness of professional-development activities should be judged in a way that takes account of both the achievement of intended outcomes and the unintended consequences that may result. Our research project set out to create a robust approach that school staff members could use to assess the impact of professional-development programs on leadership and management practice without being constrained in this judgment by the stated aims of the program. In the process, we identified a number of factors and requirements relevant to a wider audience than that concerned with the development of leadership and management in England. Such an assessment has to rest upon a clear understanding of educational leadership,a clearly articulated model of practice, and a clear model of potential forms of impact. Such foundations, suitably adapted to the subject being addressed, are appropriate for assessing all teacher professional development

Individual leader to interdependent leadership: A case study in leadership development and tripartite evaluation

This article is available open access through the publisher’s website at the link below. Copyright @ 2013 Sage Publications.The Problem - In this case study we see a move away from orthodox views of school leadership as “headship” to a more contemporary model of educational leadership wherein we note a departure from functional, curricula-based school leadership toward more human resource development (HRD) approaches. The aim of this study was to consider the effectiveness of an educational development program for middle leaders within an educational establishment. The Solution - We examined the impact of a bespoke higher education leadership development intervention in Leadership (and Change) on the formation and cohesiveness of a newly formed innovative leadership structure. The Stakeholders - The leadership development intervention was designed through a tripartite collaboration including a university, senior school leaders, and staff. The intervention was designed to shift leadership from individual leader agency to interdependent human leadership agency. Through tripartite evaluation we uncover leadership development praxis that transcends the boundaries of conventional educational leadership and reemphasizes the benefits of bridging the academic/practitioner divide and the application of theory to praxis

Relação treinador-atleta e exercício da liderança no desporto: a percepção de treinadores de alta competição

Neste artigo apresentamos os resultados de quatro entrevistas levadas a cabo com treinadores de alta competição portugueses, onde se procurou recolher informações sobre as competências necessárias para exercer a actividade de treinador, os princípios e filosofia adoptada no trabalho, as principais áreas de exercício da liderança e os valores defendidos na modalidade e na prática profissional. Os resultados permitiram verificar um acordo quanto à importância de possuírem boas competências conceptuais e pessoais, princípios claros e aceites pelos atletas, boas condições de trabalho e atletas com qualidade para a alta competição. Paralelamente, foi evidente a complexidade de tarefas assumidas na orientação dos atletas (nove dimensões do exercício da liderança). Por último, é de salientar a importância dada à obtenção dos resultados competitivos (objectivo principal) em conjunto com a análise satisfatória do trabalho realizado e a valorização do desenvolvimento pessoal, tanto no treinador como nos atletas (objectivos “periféricos”).Coach-athlete relationship and leadership practice: the perceptions of four high level competition coaches. On this article we present the results on interviewing four high level competition Portuguese coaches. The aim was to look for information on the essential coaching competences, the working principles and philosophy, the main leadership exercise areas and the defended values on sports and professional practice. The results showed the relevancy of gathering good conceptual and personal competencies, clear and accepted principals, good working conditions and qualified athletes. Also evident were the complex tasks assumed on guiding the athletes (nine leadership exercise dimensions were found). Finally, it is essential to point out the importance given to obtaining sporting results (main goal) as well as the satisfactory working analyses and the value given to coaches’ and athletes’ self-development (side goals).(undefined

The influence of distributed leadership on teachers' organizational commitment: a multilevel approach

In the present study the effects of a cooperative leadership team, distributed leadership, participative decision-making, and context variables on teachers' organizational commitment are investigated. Multilevel analyses on data from 1522 teachers indicated that 9% of the variance in teachers' organizational commitment is attributable to differences between schools. The analyses revealed that especially the presence of a cooperative leadership team and the amount of leadership support played a significantly positive key role in predicting teachers' organizational commitment. Also, participative decision-making and distribution of the supportive leadership function had a significant positive impact on teachers' organizational commitment. In contrast, distribution of the supervisory leadership function and teachers' job experience had a significant negative impact

The Importance of Ethics and Ethical Leadership in the Accounting Profession

The emergence of the twenty-first century was plagued with extensive, evasive and disheartening leadership failures. Despite the accounting profession’s standards of professional ethics, it was also tainted with ethical leadership indiscretions during this era. In response to these ethical leadership failings, renewed interest in developing accounting professionals with strong ethical principles and ethical leadership behaviors has emerged. In many firms training and development of ethical behavior is now at the forefront of the firm’s communications and professional development efforts. The question remains however, can the profession instill in its members the importance of ethical conduct? Can ethical leaders be developed that model and monitor ethical behavior? In response to the call for leaders who are ethical and moral, this research examined a model that examines ethical leadership and its impact on leader effectiveness for leaders within the accounting industry. The analysis shows that ethical and transformational leadership make incremental independent contributions in explaining leader effectiveness. The study comments on how the findings that ethically and morally focused leaders may impact the accounting profession and restore an industry tarnished with accusations of unethical behavior to one that regains its original prominence based on consistent, moral, ethical, and effective leaders

Child Psychosocial Adjustment and Parenting in Families Affected by Maternal HIV/AIDS

Child adjustment and parenting were examined in 23 9-through 16-year-old youth from families affected by maternal HIV infection and 20 same-age peers whose mothers were not infected. Children whose mothers were seropositive reported significantly more externalizing problems. Infected mothers reported less age-appropriate supervision/monitoring relative to non-infected mothers. Better mother-child relationship quality and less impairment in parental supervision/monitoring of age-appropriate youth behaviors were associated with fewer externalizing difficulties among the HIV-positive group only. Similarly, only among HIV-infected mothers was refraining from engaging in inconsistent disciplinary tactics associated with lower reports of internalizing and externalizing problems. These data highlight the promise of programs targeting parenting skills to prevent or ameliorate child difficulties

Governance tools for board members : adapting strategy maps and balanced scorecards for directorial action

The accountability of members of the board of directors of publicly traded companies has increased over years. Corresponding to these developments, there has been an inadequate advancement of tools and frameworks to help directorial functioning. This paper provides an argument for design of the Balanced Scorecard and Strategy Maps made available to the directors as a means of influencing, monitoring, controlling and assisting managerial action. This paper examines how the Balanced Scorecard and Strategy Maps could be modified and used for this purpose. The paper suggests incorporating Balanced Scorecards in the Internal Process perspective, ‘internal’ implying here not just ‘internal to the firm’, but also ‘internal to the inter-organizational system’. We recommend that other such factors be introduced separately under a new ‘perspective’ depending upon what the board wants to emphasize without creating any unwieldy proliferation of measures. Tracking the Strategy Map over time by the board of directors is a way for the board to take responsibility for the firm’s performance. The paper makes a distinction between action variables and monitoring variables. Monitoring variables are further divided on the basis of two considerations: a) whether results have been met or not and b) whether causative factors have met the expected levels of performance or not. Based on directorial responsibilities and accountability, we take another look at how the variables could be specified more completely and accurately with directorial recommendations for executives