Middle Management Strategic Roles: Strategic Role Conflict and its Antecedents

The middle-management perspective has produced a great understanding of the connection of middle managers involvement in strategy and organizational outcomes (Floyd & Wooldridge, 1992, 1996; Floyd & Wooldridge, 2000; Wooldridge & Floyd, 1990). Strategic role conflict has been identified in the literature as a hindrance, even an impediment, to effective middle-management involvement in strategy (Floyd & Lane, 2000). Despite a growing body of theoretical work by scholars on the strategy process, there has been limited empirical research of the antecedents of strategic role conflict. Drawing from the literatures of role conflict, middle management perspective, and social exchange theory, this dissertation hypothesized that demographic characteristics of middle managers, the nature of their position within the organization, the quality of their relationships with top management, and the degree of dissimilarity of their environmental perceptions vis-à-vis top management are associated with middle managers’ strategic role conflict. A large, global manufacturing company based in the United States participated in the study. Survey data was collected from 249 middle managers at four organizational levels within two divisions. Two structural models were tested. Data showed that the more parsimonious model was not supported while the less parsimonious model was supported. Results indicated that key predictors of middle managers’ strategic role conflict were the amount of boundary spanning that middle managers engage in as part of their jobs, the degree of disparity in their perception of the products and factors markets vis-à-vis top management, the frequency of their direct communication with their top manager, the amount of mutual trust between the top manager and the middle manager, and the amount of disparity in the feelings of mutual affect between the top manager and the middle manager. This study contributes to the strategy literature by demonstrating the applicability of role conflict theory to the strategy process in explicating links between strategic role conflict and its antecedents. A better understanding of strategic role conflict is important to the strategy process literature because of its theorized interference with middle manager’s effective strategic performance and its possible negative consequences for the organization. An alternative model of strategic role conflict is presented

The NGC 4013 tale: a pseudo-bulged, late-type spiral shaped by a major merger

Many spiral galaxy haloes show stellar streams with various morphologies when observed with deep images. The origin of these tidal features is discussed, either coming from a satellite infall or caused by residuals of an ancient, gas-rich major merger. By modelling the formation of the peculiar features observed in the NGC 4013 halo, we investigate their origin. By using GADGET -2 with implemented gas cooling, star formation, and feedback, we have modelled the overall NGC 4013 galaxy and its associated halo features. A gas-rich major merger occurring 2.7-4.6 Gyr ago succeeds in reproducing the NGC 4013 galaxy properties, including all the faint stellar features, strong gas warp, boxy-shaped halo and vertical 3.6 mum luminosity distribution. High gas fractions in the progenitors are sufficient to reproduce the observed thin and thick discs, with a small bulge fraction, as observed. A major merger is able to reproduce the overall NGC 4013 system, including the warp strength, the red colour and the high stellar mass density of the loop, while a minor merger model cannot. Because the gas-rich model suffices to create a pseudo-bulge with a small fraction of the light, NGC 4013 is perhaps the archetype of a late-type galaxy formed by a relatively recent merger. Then late type, pseudo-bulge spirals are not mandatorily made through secular evolution, and the NGC 4013 properties also illustrate that strong warps in isolated galaxies may well occur at a late phase of a gas-rich major merger.Comment: 11 pages,9 figures,accepted for publication in MNRA

Does the dwarf galaxy system of the Milky Way originate from Andromeda?

The Local Group is often seen to be a quiescent environment without significant merger events. However an ancient major merger may have occurred in the most massive galaxy. Numerical simulations have shown that tidal tails formed during gas-rich major mergers are long-lived and could be responsible for old stellar streams and likely induce the formation of tidal dwarf galaxies (TDGs). Using several hydrodynamical simulations we have investigated the most prominent tidal tail formed during the first passage, which is gas-rich and contains old and metal poor stars. We discovered several striking coincidences after comparing its location and motion to those of the Milky Way (MW) and of the Magellanic Clouds (MCs). First, the tidal tail is sweeping a relatively small volume in which the MW precisely lies. Because the geometry of the merger is somehow fixed by the anisotropic properties of the Giant Stream (GS), we evaluate the chance of the MW to be at such a rendez-vous with this gigantic tidal tail to be 5 %. Second, the velocity of the tidal tail matches the LMC proper motion, and reproduce quite well the geometrical and angular momentum properties of the MW dwarfs, i.e. the so-called disk of satellites, better called Vast Polar Structure (VPOS). Third, the simulation of the tidal tail reveals one of the formed TDG with mass and location almost comparable to those of the LMC. Our present modeling is however too limited to study the detailed interaction of gas-rich TDGs with the potential of the MW, and a complementary study is required to test whether the dwarf intrinsic properties can be accounted for by our scenario. Nevertheless this study suggests a causal link between an ancient, gas-rich major merger at the M31 location, and several enigma in the Local Group, the GS, the VPOS, and the presence of the MCs.Comment: 17 pages accepted MNRA

Towards a robust estimate of the merger rate evolution using near-IR photometry

We use a combination of deep, high angular resolution imaging data from the CDFS (HST/ACS GOODS survey) and ground based near-IR $K_s$ images to derive the evolution of the galaxy major merger rate in the redshift range $0.2 \leq z \leq 1.2$. We select galaxies on the sole basis of their J-band rest-frame, absolute magnitude, which is a good tracer of the stellar mass. We find steep evolution with redshift, with the merger rate $\propto (1+z)^{3.43\pm0.49}$ for optically selected pairs, and $\propto (1+z)^{2.18\pm0.18}$ for pairs selected in the near-IR. Our result is unlikely to be affected by luminosity evolution which is relatively modest when using rest-frame J band selection. The apparently more rapid evolution that we find in the visible is likely caused by biases relating to incompleteness and spatial resolution affecting the ground based near IR photometry, underestimating pair counts at higher redshifts in the near-IR. The major merger rate was $\sim$5.6 times higher at $z\sim1.2$ than at the current epoch. Overall 41%$\times$(0.5\gyr/$\tau$) of all galaxies with $M_J\leq-19.5$ have undergone a major merger in the last \sim8 \gyr, where $\tau$ is the merger timescale. Interestingly, we find no effect on the derived major merger rate due to the presence of the large scale structure at $z=0.735$ in the CDFS.Comment: Accepted for Publication in ApJ. 9 Figure

Could M31 be the result of a major merger?

We investigated a scenario in which M31 could be the remnant of a gas-rich major merger. Galaxy merger simulations, highly constrained by observations, were run using GADGET 2 in order to reproduce M31. We succeeded in reproducing the global shape of M31, the thin disk and the bulge, and in addition some of the main M31 large-scale features, such as the thick disk, the 10kpc ring and the Giant Stream. This lead to a new explanation of the Giant Stream which could be caused by tidal tail stars that have been captured by the galaxy potential.Comment: Proceedings for the conference "Assembling the puzzle of the Milky Way", 2 page

Morphology with Light Profile Fitting of Confirmed Cluster Galaxies at z=0.84

We perform a morphological study of 124 spectroscopically confirmed cluster galaxies in the z=0.84 galaxy cluster RX J0152.7-1357. Our classification scheme includes color information, visual morphology, and 1-component and 2-component light profile fitting derived from Hubble Space Telescope riz imaging. We adopt a modified version of a detailed classification scheme previously used in studies of field galaxies and found to be correlated with kinematic features of those galaxies. We compare our cluster galaxy morphologies to those of field galaxies at similar redshift. We also compare galaxy morphologies in regions of the cluster with different dark-matter density as determined by weak-lensing maps. We find an early-type fraction for the cluster population as a whole of 47%, about 2.8 times higher than the field, and similar to the dynamically young cluster MS 1054 at similar redshift. We find the most drastic change in morphology distribution between the low and intermediate dark matter density regions within the cluster, with the early type fraction doubling and the peculiar fraction dropping by nearly half. The peculiar fraction drops more drastically than the spiral fraction going from the outskirts to the intermediate-density regions. This suggests that many galaxies falling into clusters at z~0.8 may evolve directly from peculiar, merging, and compact systems into early-type galaxies, without having the chance to first evolve into a regular spiral galaxy.Comment: 13 pages, 11 figures, accepted for publication in A&

Comparación del Análisis Dinamico de una Vivienda Multifamiliar por los Métodos Modal Espectral y Tiempo Historia en Concepcion

La presente investigación tuvo como problema general: ¿Cómo es la comparación del análisis dinámico de una vivienda multifamiliar por los métodos modal espectral y tiempo historia en Concepción?, el objetivo general fue: Comparar el análisis dinámico de una vivienda multifamiliar por los métodos modal espectral y tiempo historia en Concepción y la hipótesis general que se verificó fue: El resultado de la comparación de ambos métodos dinámicos uno tiene una mejor determinación sobre el comportamiento sismorresistente de una vivienda multifamiliar. El método general de investigación fue el científico, el tipo de investigación fue aplicada, el nivel de investigación fue el descriptivo comparativo y el diseño de la investigación: no experimental, en lo concerniente a la La población está conformada por todas las viviendas de la urbanización de los Cipreses del distrito de Orcotuna de la provincia de Concepción y la muestra fue la vivienda multifamiliar de la familia Colonio Sobrevilla, la muestra viene a ser los elementos estructurales por ser único cada elemento en su comportamiento estructural. Todo esto nos llevó a la conclusión general que la vivienda multifamiliar de la familia Colonio Sobrevilla por los métodos modal espectral y tiempo – historia llegando a la conclusión de que el primer método mencionado es el más crítico en lo que refiere a los desplazamientos laterales debido a que estos alcanzan un valor máximo de 0.0067 y 0.0068 para el sentido X – X y para el sentido Y – Y respectivamente, mientras que el segundo método mencionado es el más crítico en lo que refiere a la cortante basal debido a que los registros Loreto 2019 presentan un factor de escala mayor a 1.00 en ambos sentidos lo que ocasionará que las cargas aumenten y el presupuesto de la obra sea mayor

Reproducing properties of MW dSphs as descendants of DM-free TDGs

The Milky Way (MW) dwarf spheroidal (dSph) satellites are known to be the most dark-matter (DM) dominated galaxies with estimates of dark to baryonic matter reaching even above one hundred. It comes from the assumption that dwarfs are dynamically supported by their observed velocity dispersions. However their spatial distributions around the MW is not at random and this could challenge their origin, previously assumed to be residues of primordial galaxies accreted by the MW potential. Here we show that alternatively, dSphs could be the residue of tidal dwarf galaxies (TDGs), which would have interacted with the Galactic hot gaseous halo and disk. TDGs are gas-rich and have been formed in a tidal tail produced during an ancient merger event at the M31 location, and expelled towards the MW. Our simulations show that low-mass TDGs are fragile to an interaction with the MW disk and halo hot gas. During the interaction, their stellar content is progressively driven out of equilibrium and strongly expands, leading to low surface brightness feature and mimicking high dynamical M/L ratios. Our modeling can reproduce the properties, including the kinematics, of classical MW dwarfs within the mass range of the Magellanic Clouds to Draco. An ancient gas-rich merger at the M31 location could then challenge the currently assumed high content of dark matter in dwarf galaxies. We propose a simple observational test with the coming GAIA mission, to follow their expected stellar expansion, which should not be observed within the current theoretical framework.Comment: 17 pages, 11 figures, accepted by the Monthly Notices of the Royal Astronomical Society (MNRAS