Study of (Ba3MMWO9)-M-II-W-IV (M-II = Ca, Zn; M-IV = Ti, Zr) perovskite oxides: Competition between 3C and 6H perovskite structures

We describe an investigation of (Ba3MMWO9)-M-II-W-IV oxides for M-II = Ca, Zn, and other divalent metals and M-IV = Ti, Zr. In general, a 1:2-ordered 6H (hexagonal, P6(3)/mmc) perovskite structure is stabilized at high temperatures (1300 degrees C) for all of the (Ba3MTiWO9)-Ti-II oxides investigated. An intermediate phase possessing a partially ordered 1:1 double perovskite (3C) structure with the cation distribution, Ba-2(Zn2/3Ti1/3)(W2/3Ti1/3)O-6, is obtained at 1200 degrees C for Ba3ZnTiWO9. Sr substitution for Ba in the latter stabilizes the cubic 3C structure instead of the 6H structure. A metastable Ba3CaZrWO9 that adopts the 3C (cubic, Fm (3) over barm) structure has also been synthesized by a low-temperature metathesis route. Besides yielding several new perovskite oxides that may be useful as dielectric ceramics, the present investigation provides new insights into the complex interplay of crystal chemistry (tolerance factor) and chemical bonding (anion polarization and d(0)-induced distortion of metal-oxygen octahedra) in the stabilization of 6H versus 3C perovskite structures for the (Ba3MMWO9)-M-II-W-IV series.

Strategic Soft Human Resource Management - The Very Idea

On the one hand this thesis attempts to develop and empirically test an ethically defensible theorization of the relationship between human resource management (HRM) and competitive advantage. The specific empirical evidence indicates that at least part of HRM's causal influence on employee performance may operate indirectly through a social architecture and then through psychological empowerment. However, in particular the evidence concerning a potential influence of HRM on organizational performance seems to put in question some of the rhetorics within the HRM research community. On the other hand, the thesis tries to explicate and defend a certain attitude towards the philosophically oriented debates within organization science. This involves suggestions as to how we should understand meaning, reference, truth, justification and knowledge. In this understanding it is not fruitful to see either the problems or the solutions to the problems of empirical social science as fundamentally philosophical ones. It is argued that the notorious problems of social science, in this thesis exemplified by research on HRM, can be seen as related to dynamic complexity in combination with both the ethical and pragmatic difficulty of ”laboratory-like-experiments”. Solutions … can only be sought by informed trials and errors depending on the perceived familiarity with the object(s) of research. The odds are against anybody who hopes for clearly adequate social scientific answers to more complex questions. Social science is in particular unlikely to arrive at largely accepted knowledge of the kind ”if we do this, then that will happen”, or even ”if we do this, then that is likely to happen”. One of the problems probably facing most of the social scientific research communities is to specify and agree upon the ”this ” and the ”that” and provide convincing evidence of how they are (causally) related. On most more complex questions the role of social science seems largely to remain that of contributing to a (critical) conversation, rather than to arrive at more generally accepted knowledge. This is ultimately what is both argued and, in a sense, demonstrated using research on the relationship between HRM and organizational performance as an example.

The Enlightenment Idea of History as a Legitimation Tool of Kemalism in Turkey

The study analyzes the effort to build political legitimacy in the Republic of Turkey by ex-ploring a group of influential texts produced by Kemalist writers. The study explores how the Kemalist regime reproduced certain long-lasting enlightenment meta-narrative in its effort to build political legitimacy. Central in this process was a hegemonic representation of history, namely the interpretation of the Anatolian Resistance Struggle of 1919 1922 as a Turkish Revolution executing the enlightenment in the Turkish nation-state. The method employed in the study is contextualizing narratological analysis. The Kemalist texts are analyzed with a repertoire of concepts originally developed in the theory of narra-tive. By bringing these concepts together with epistemological foundations of historical sciences, the study creates a theoretical frame inside of which it is possible to highlight how initially very controversial historical representations in the end manage to construct long-lasting, emotionally and intellectually convincing bases of national identity for the secular middle classes in Turkey. The two most important explanatory concepts in this sense are di-egesis and implied reader. The diegesis refers to the ability of narrative representation to create an inherently credible story-world that works as the basis of national community. The implied reader refers to the process where a certain hegemonic narrative creates a formula of identification and a position through which any individual real-world reader of a story can step inside the narrative story-world and identify oneself as one of us of the national narra-tive. The study demonstrates that the Kemalist enlightenment meta-narrative created a group of narrative accruals which enabled generations of secular middle classes to internalize Kemalist ideology. In this sense, the narrative in question has not only worked as a tool utilized by the so-called Kemalist state-elite to justify its leadership, but has been internalized by various groups in Turkey, working as their genuine world-view. It is shown in the study that secular-ism must be seen as the core ingredient of these groups national identity. The study proposes that the enlightenment narrative reproduced in the Kemalist ideology had its origin in a simi-lar totalizing cultural narrative created in and for Europe. Currently this enlightenment project is challenged in Turkey by those who are in an attempt to give religion a greater role in Turkish society. The study argues that the enduring practice of legitimizing political power through the enlightenment meta-narrative has not only become a major factor contributing to social polarization in Turkey, but has also, in contradiction to the very real potentials for crit-ical approaches inherent in the Enlightenment tradition, crucially restricted the development of critical and rational modes of thinking in the Republic of Turkey.

The role of competition and habitat in structuring small mammal communities in a tropical montane ecosystem in southern India

Small mammals were sampled in two natural habitats (montane stunted evergreen forests and montane grassland) and four anthropogenic habitats (tea, wattle, bluegum and pine plantation) in the Upper Nilgiris in southern India. Of the species trapped, eight were in montane evergreen forests and three were in other habitats. Habitat discrimination was studied in the rodents Rattus rattus and Mus famulus and the shrew Suncus montanus in the montane forest habitat. Multivariate tests on five variables (canopy cover, midstorey density, ground cover, tree density, canopy height) showed that R. rattus uses areas of higher tree density and lower canopy cover. Suncus montanus and M. famulus use habitat with higher tree density and ground cover and lower canopy height. Multivariate tests did not discriminate habitat use between the species. Univariate tests, however, showed that M. famulus uses areas of higher tree density than R. rattus and S. montanus. Rattus rattus was the dominant species in the montane forest, comprising 60.9% of total density, while the rodent Millardia meltada was the dominant species in the grassland. Studies of spatial interaction between these two species in habitats where they coexisted showed neither overlap nor avoidance between the species. Rattus rattus, however, did use areas of lower ground cover than did M. meltada. The analysis of spatial interactions between the species, habitat discrimination and use, and the removal experiments suggest that interspecific competition may not be a strong force in structuring these small mammal communities. There are distinct patterns in the use of different habitats by some species, but microhabitat selection and segregation is weak. Other factors such as intraspecific competition may play a more important role in these communities.

A Comparative Kinetic and Thermodynamic Perspective of the sigma-Competition Model in Escherichia coli

Transcription is the most fundamental step in gene expression in any living organism. Various environmental cues help in the maturation of core RNA polymerase (RNAP; alpha(2)beta beta'omega) with different sigma-factors, leading to the directed recruitment of RNAP to different promoter DNA sequences. Thus it is essential to determine the sigma-factors that affect the preferential partitioning of core RNAP among various a-actors, and the role of sigma-switching in transcriptional gene regulation. Further, the macromolecular assembly of holo RNAP takes place in an extremely crowded environment within a cell, and thus far the kinetics and thermodynamics of this molecular recognition process have not been well addressed. In this study we used a site-directed bioaffinity immobilization method to evaluate the relative binding affinities of three different Escherichia coli sigma-factors to the same core RNAP with variations in temperature and ionic strength while emulating the crowded cellular milieu. Our data indicate that the interaction of core RNAP-sigma is susceptible to changes in external stimuli such as osmolytic and thermal stress, and the degree of susceptibility varies among different sigma-factors. This allows for a reversible sigma-switching from housekeeping factors to alternate sigma-factors when the organism senses a change in its physiological conditions.

The role of tusks, musth and body size in male-male competition among Asian elephants, Elephas maximus

The evolution of sexually dimorphic, elaborate male traits that are seemingly maladaptive may be driven by sexual selection (male-male competition and or female mate choice). Tusk possession in the Asian elephant is sexually dimorphic and exaggerated but its role in male-male competition has not yet been determined. We examined the role of the tusks in establishing dominance along with two other known male-male signals, namely, body size and musth (a temporary physiologically heightened sexual state) in an Asian elephant population in northeastern India with equal proportions of tusked and tuskless males. We observed 116 agonistic interactions with clear dominance outcomes between adult (>15 years) males during 458 field days in the dry season months of 2008-2011. A generalized linear mixed-effects model was used to predict the probability of winning as a function of body size, tusk possession and musth status relative to the opponent. A hierarchy of the three male-male signals emerged from this analysis, with musth overriding body size and body size overriding tusk possession. In this elephant population tusk possession thus plays a relatively minor role in male-male competition. An important implication of musth and body size being stronger determinants of dominance than tusk possession is that it could facilitate rapid evolution of tuskless males in the population under artificial selection against tusked individuals, which are poached for ivory. (C) 2013 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Modification of Extended Open Frameworks with Fluorescent Tags for Sensing Explosives: Competition between Size Selectivity and Electron Deficiency

Three new electron-rich metal-organic frameworks (MOF-1-MOF-3) have been synthesized by employing ligands bearing aromatic tags. The key role of the chosen aromatic tags is to enhance the -electron density of the luminescent MOFs. Single-crystal X-ray structures have revealed that these MOFs form three-dimensional porous networks with the aromatic tags projecting inwardly into the pores. These highly luminescent electron-rich MOFs have been successfully utilized for the detection of explosive nitroaromatic compounds (NACs) on the basis of fluorescence quenching. Although all of the prepared MOFs can serve as sensors for NACs, MOF-1 and MOF-2 exhibit superior sensitivity towards 4-nitrotoluene (4-NT) and 2,4-dinitrotoluene (DNT) compared to 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitrobenzene (TNB). MOF-3, on the other hand, shows an order of sensitivity in accordance with the electron deficiencies of the substrates. To understand such anomalous behavior, we have thoroughly analyzed both the steady-state and time-resolved fluorescence quenching associated with these interactions. Determination of static Stern-Volmer constants (K-S) as well as collisional constants (K-C) has revealed that MOF-1 and MOF-2 have higher K-S values with 4-NT than with TNT, whereas for MOF-3 the reverse order is observed. This apparently anomalous phenomenon was well corroborated by theoretical calculations. Moreover, recyclability and sensitivity studies have revealed that these MOFs can be reused several times and that their sensitivities towards TNT solution are at the parts per billion (ppb) level.

How mutualisms between plants and insects are stabilized

While the idea of cooperation between individuals of a species has received considerable attention, how mutualistic interactions between species can be protected from cheating by partners in the interaction has only recently been examined from theoretical and empirical perspectives. This paper is a selective review of the recent literature on host sanctions, partner-fidelity feedback and the concept of punishment in such mutualisms. It describes new ideas, borrowed from microeconomics, such as screening theory with and without competition between potential partners for a host. It explores mutualism-stabilizing mechanisms using examples from interactions between figs and fig wasps, and those between ants and plants. It suggests new avenues for research.

Continuum in the X-Z-Y Weak Bonds: Z= Main Group Elements

The Continuum in the variation of the X-Z bond length change from blue-shifting to red-shifting through zero-shifting in the X-Z---Y complex is inevitable. This has been analyzed by ab-initio molecular orbital calculations using Z= Hydrogen, Halogens, Chalcogens, and Pnicogens as prototypical examples. Our analysis revealed that, the competition between negative hyperconjugation within the donor (X-Z) molecule and Charge Transfer (CT) from the acceptor (Y) molecule is the primary reason for the X-Z bond length change. Here, we report that, the proper tuning of X-and Y-group for a particular Z-can change the blue-shifting nature of X-Z bond to zero-shifting and further to red-shifting. This observation led to the proposal of a continuum in the variation of the X-Z bond length during the formation of X-Z---Y complex. The varying number of orbitals and electrons available around the Z-atom differentiates various classes of weak interactions and leads to interactions dramatically different from the H-Bond. Our explanations based on the model of anti-bonding orbitals can be transferred from one class of weak interactions to another. We further take the idea of continuum to the nature of chemical bonding in general. (C) 2015 Wiley Periodicals, Inc.