Growing Up In Water Valley, Kentucky

Growing Up In Water Valley, Kentucky Zee W. Piqu

Effects of conversion of pure pine stands on spiders of canopy space (Arachnida: Araneae) as potential pest antagonists

Die historische Waldwirtschaft Sachsens war vor allem durch massive Eingriffe in das natürliche Baumartenspektrum geprägt. Ungeregelte Übernutzungen führten im 19. Jahrhundert zur Holzarmut und zum Wiederaufbau devastierter Wälder mit robusteren Baumarten (Pinus sylvestris, Picea abies) (SMUL 2003). Infolge der nicht standortsgerechten Bestockung und Förderung strukturarmer Bestände wurden Zufallsnutzungen wie Sturmwurf, Schneebruch und besonders Insektenkalamitäten begünstigt (BUTTER 2000, OTTO 2000). Seit der Neuordnung der Forstwirtschaft gilt es, naturferne Bestockungen in naturnahe, leistungsfähige und stabile Mischwälder umzubauen, um die Nutz-, Schutz- und Erholungsfunktionen nachhaltig zu sichern (SPELLMANN 1995, 1996, IRRGANG 1999, BUTTER 2000). Dieses Ziel lässt sich vorzugsweise durch die Förderung der natürlichen und Einbringung der künstlichen Verjüngung steuern (HEINSDORF 1999, LAF 1999, LEDER 2002). Unterschiedliche Baumartenmischungen (z.B. Quercus sp., Fagus sylvatica L.) und eine variierende Bestandesstrukturierung nehmen dabei Einfluss auf mikroklimatische Parameter (HORVATH et al. 2000, JÄKEL et al. 2004), die eine Steigerung der Diversität und des Leistungspotenzials der Antagonistengilde erwarten lassen (HARTLEY & MACMAHON 1980, SCHAEFER 2001). Die vorliegende Untersuchung befasste sich mit den Auswirkungen verschiedener Umbaumaßnahmen von Kiefernmonokulturen (Naturverjüngung, Voranbau von Traubeneiche und Rotbuche) auf die Struktur und Funktion der akrodendrischen Spinnenzönose. Neben den Steuergrößen (Mikroklima, Raumstruktur) wurde die Funktionalität der Araneae als Antagonisten von phyllophagen Lepidoptera im Kronenraum thematisiert.The effects of conversion of commercial pine stands by planting decidious trees or tolerating natural regeneration were investigated on the structure and functionality of spiders in the tree crown layer of northern Saxonian Lowlands. The study sites (n=7) were established in two different areas (latency- & gradation area), which were characterized by different climatic parameters and the susceptibility to mass gradation of pest insects. One pure pine forest served as reference in each area. Spiders were collected by branch-eclectors (n=16 per forest stand) and flight-intercepting traps (n=8 per forest stand) during the vegetation periods of 2000 and 2001. The results were based on the determination of 19.280 Araneae (72 species, 16 families), among them 5 Araneae listed in the Red Data Book of Germany and 5 species of Saxony respectively. The dominant families were Linyphiidae (n=25), Theridiidae (n=9) and Salticidae (n=7) regarding to their species abundance. In contrast to this the relative abundance and activity biomass shows a dominance of the Philodromidae (30 %, 17 %), Clubionidae (23 %, 23 %) and Thomisidae (10 %, 13 %). Forest conversion, especially the grow of beech and oak trees on the understory in the crown layer, showed effects. In the latency area species diversity, individual numbers and activity biomass increased with complexity of the forest structure in the tree crown layer. Similar results like the contrasting effects of forest conversion on ground-dwelling spiders wasn´t confirm. The coincidence between different live stages of phytophagous Lepidoptera (Dendrolimus pini Linné) and spider antagonists indicated an increase in the predation potential, due to high activity abundance

The Early Stages of the Integration of the Internet in EU Newsrooms

The current study explores the perceived integration of the internet inside European newsrooms. The authors carried out a survey with 239 journalists working for 40 of the most-read outlets in 11 European countries.The study shows that journalists consider the internet a useful tool mainly for practical functions, rather than to enhance the core values and functions of their profession. However, news production continues to be based on direct interaction, and journalists’ professional identity is still anchored to print newspapers. Moreover, a lack of communication between publishers and newsrooms emerges. Professional and personal profiles and nationality play a relevant role in the development of attitudes towards the implementation of the internet in newsrooms

A Generalized Q-operator for U_q(\hat(sl_2)) Vertex Models

In this paper, we construct a Q-operator as a trace of a representation of the universal R-matrix of $U_q(\hat{sl}_2)$ over an infinite-dimensional auxiliary space. This auxiliary space is a four-parameter generalization of the q-oscillator representations used previously. We derive generalized T-Q relations in which 3 of these parameters shift. After a suitable restriction of parameters, we give an explicit expression for the Q-operator of the 6-vertex model and show the connection with Baxter's expression for the central block of his corresponding operator.Comment: 22 pages, Latex2e. This replacement is a revised version that includes a simple explicit expression for the Q matrix for the 6-vertex mode

Robust and efficient preconditioners for the discontinuous Galerkin time-stepping method

The discontinuous Galerkin time-stepping method has many advantageous properties for solving parabolic equations. However, its practical use has been limited by the large and challenging nonsymmetric systems to be solved at each time-step. This work develops a fully robust and efficient preconditioning strategy for solving these systems. We first construct a left preconditioner, based on inf-sup theory, that transforms the linear system to a symmetric positive definite problem that can be solved by the preconditioned conjugate gradient (PCG) algorithm. We then prove that the transformed system can be further preconditioned by an ideal block diagonal preconditioner, leading to a condition number κ bounded by 4 for any time-step size, any approximation order and any positive self-adjoint spatial operators. Numerical experiments demonstrate the low condition numbers and fast convergence of the algorithm for both ideal and approximate preconditioners, and show the feasibility of the high-order solution of large problems

From governance to choreography: coordination of innovation ecosystems

Purpose – Innovation ecosystems can emerge and grow organically, but the process can also be managed through conscious intervention. Therefore, this study observes different motivations and expectations for each group of actors. The lack of alignment between actors could have a negative influence on the development of innovation ecosystems. This study aims to analyze the coordination strategies of the actors throughout the life cycle of innovation ecosystems. Design/methodology/approach – This study develops and proposes a model for coordinating innovation ecosystems based on the theoretical backgrounds of the ecosystem life cycle and ecosystem coordination. Findings – This study argues that each stage of an innovation ecosystem’s life cycle – inception, launching, growth and maturity – demands different coordination strategies. Initially, networks are simpler and thus the coordination issues are less difficult. However, as the ecosystem evolves and the complexity of the networks increases, a more sophisticated strategy, such as orchestration or choreography, is needed. Research limitations/implications – This is a theoretical study that recommends further research to test this model. Practical implications – The understanding of coordination and stages of the life cycle of an innovation ecosystem can guide actors in the design of strategies for developing of ecosystems. Social implications – The proposed framework could support strategies to engage civil society in actions to develop innovation ecosystems. Originality/value – This study presents a framework to understand the coordination strategies better, considering the stages of an innovation ecosystem’s life cycle

Multicolor urn models with reducible replacement matrices

Consider the multicolored urn model where, after every draw, balls of the different colors are added to the urn in a proportion determined by a given stochastic replacement matrix. We consider some special replacement matrices which are not irreducible. For three- and four-color urns, we derive the asymptotic behavior of linear combinations of the number of balls. In particular, we show that certain linear combinations of the balls of different colors have limiting distributions which are variance mixtures of normal distributions. We also obtain almost sure limits in certain cases in contrast to the corresponding irreducible cases, where only weak limits are known.Comment: Published in at http://dx.doi.org/10.3150/08-BEJ150 the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm