790 research outputs found

    A Cross-Cultural Test of Implicit Leadership Theory

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    This research builds on Implicit Leadership Theory, which suggests that a leader’s performance is likely to be higher when there is congruence between a follower’s prototype of what a leader should be and his or her perception of the leader’s behaviour. The essence of effective leadership, according to this theory, is being seen as a leader by others. Data were collected from 196 leaders and 1,738 followers from 23 countries within Cargill Incorporated, a US food and agricultural multinational. The research was conducted in two phases. During the first phase data were collected on followers’ desired leadership values and their perception of their leader’s behaviour on the same dimensions. These data were used to compute a congruence score based on a weighted sum of absolute differences. The congruence score data formed the heart of an individualised Leadership Fit Report written for each leader in the study showing the extent of congruence across 21 leadership characteristics (see Appendix A). The second phase of the study focused on a subset of 933 followers from five countries testing the two hypotheses. The two hypotheses in Phase Two were partially supported. The first was that congruence between desired leadership values and perceived behaviour leads to high performance of a leader and incongruence leads to lower performance. The second was that the relationship between congruence and leader performance varied by nationality. The cross-cultural test of Implicit Leadership Theory captured in Hypothesis 2 was particularly important to Cargill because it revealed unique and important 9 differences between the five countries included in the second data set. This study found that the nature of the relationship between congruence and leader performance varies significantly between all five countries. More specifically the data suggests that congruence does not always lead to high performance. This study, albeit exploratory, makes theoretical, methodological and practical contributions in the following ways. i. A cross cultural test of Implicit Leadership Theory in a multinational organisation with a significant sample size. ii. An existing desired leadership values questionnaire was used and developed further to measure leadership values and leader perception. iii. All 196 leaders received a personalised feedback report showing the level of congruence (or degree of fit) for 21 leadership characteristics. iv. A methodological contribution was made by using Polynomial Regression Equations and Response Surface Methodology to measure the nature of the relationship between desired leadership values, perceived behaviour and leaders’ performance. Implicit Leadership Theory was shown to be complex yet very relevant to management practice. The research undertaken was exploratory yet it has created the basis for on going discussion

    A Remote Laser System for Material Characterization at High Temperatures

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    For many years, new techniques have been developed to overcome the problems involved with the generation and detection of ultrasound in materials at high temperature [1,2]. A non-contacting technique is described using lasers to generate and detect ultrasound and which can be used to study the variation in acoustic velocity as a function of temperature. Results are presented for the change in longitudinal velocity (vâ„“) with increasing temperature in five polycrystalline materials, namely Dural, aluminum, AISI-310 stainless steel, iron and graphite

    Selective in vitro replication of herpes simplex virus type 1 (HSV-1) ICP34.5 null mutants in primary human CNS tumours--evaluation of a potentially effective clinical therapy.

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    Primary tumours of the central nervous system (CNS) are an important cause of cancer-related deaths in adults and children. CNS tumours are mostly glial cell in origin and are predominantly astrocytomas. Conventional therapy of high-grade gliomas includes maximal resection followed by radiation treatment. The addition of adjuvant chemotherapy provides little improvement in survival time and hence assessment of novel therapies is imperative. We have evaluated the potential therapeutic use of the herpes simplex virus (HSV) mutant 1716 in the treatment of primary brain tumours. The mutant is deleted in the RL1 gene and fails to produce the virulence factor ICP34.5. 1716 replication was analysed in both established human glioma cell lines and in primary cell cultures derived from human tumour biopsy material. In the majority of cultures, virus replication occurred and consequential cell death resulted. In the minority of tumour cell lines which are non-permissive for mutant replication, premature shut-off of host cell protein synthesis was induced in response to lack of expression of ICP34.5. Hence RL1-negative mutants have the distinct advantage of providing a double hit phenomenon whereby cell death could occur by either pathway. Moreover, 1716, by virtue of its ability to replicate selectively within a tumour cell, has the potential to deliver a 'suicide' gene product to the required site immediately. It is our opinion that HSV which fails to express ICP34.5 could provide an effective tumour therapy

    Silver(I) complexes of 9-anthracenecarboxylic acid and imidazoles: synthesis, structure and antimicrobial activity

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    [Ag2(9-aca)2] (1) (9-acaH = 9-anthracenecarboxylic acid) reacts with a series of imidazoles to give [Ag(imidH)2.3(CH3CN)0.7](9-aca) (3), [Ag6(imidH)4(9-aca)6(MeOH)2] (4), {[Ag(1-Me-imid)2]2[Ag4(9- aca)6]} (5), {[Ag(1-Bu-imid)2]2[Ag4(9-aca)6]} (6) and [Ag(apim)](9-aca)·H2O (7) (imidH = imidazole; 1-Me-imid = 1-methylimidazole; 1-Bu-imid = 1-butylimidazole; apim = 1-(3-aminopropyl)imidazole). The mononuclear complex 3, hexanuclear 4–6, and polymeric 7, were all characterised using X-ray crystallography. While many of the complexes possess excellent in vitro antifungal and antibacterial activities they are, unanimously, more effective against fungal cells. The insect, Galleria mellonella, can survive high doses of the Ag(I) complexes administered in vivo, and a number of the complexes offer significant protection to larvae infected with a lethal dose of pathogenic Candida albicans cells

    The tumor suppressor protein OPCML potentiates anti-EGFR and anti-HER2 targeted therapy in HER2-positive ovarian and breast cancer.

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    OPCML is a tumor suppressor gene that is frequently inactivated in ovarian cancer and many other cancers by somatic methylation. We have previously shown that OPCML exerts its suppressor function by negatively regulating a spectrum of receptor tyrosine kinases (RTKs), such as ErbB2/HER2, FGFR1 and EphA2, thus attenuating their related downstream signaling. The physical interaction of OPCML with this defined group of RTKs is a prerequisite for their downregulation. Overexpression/gene amplification of EGFR and HER2 is a frequent event in multiple cancers including ovarian and breast cancers. Molecular therapeutics against EGFR/HER2 or EGFR only, such as lapatinib and erlotinib respectively, were developed to target these receptors but resistance often occurs in relapsing cancers. Here we show that, though OPCML interacts only with HER2 and not with EGFR, the interaction of OPCML with HER2 disrupts the formation of the HER2-EGFR heterodimer and this translates into a better response to both lapatinib and erlotinib in HER2-expressing ovarian and breast cancer cell lines. Also, we show that high OPCML expression is associated with better response to lapatinib therapy in breast cancer patients and better survival in HER2-overexpressing ovarian cancer patients, suggesting that OPCML co-therapy could be a valuable sensitizing approach to RTK inhibitors
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