906 research outputs found

    A Broadened Approach to Understanding IT Organizational Structure

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    With the increasingly influential impact of the information systems/technology (IT) organization on most firms, it is important to understand the implications of alternative structures of the IT organization. With limited exceptions, literature in this area has focused on the locus of decision rights in the IT organization. This research uses broader dimensions found in the general organization structure literature to characterize IT organizational structure. Our analysis suggests that IT organizations aimed at promoting innovation emphasize standardization and flexibility while deemphasizing specialization, IT organizations aimed at integration emphasize standardization, and IT organizations aimed at scalability through sourcing emphasize standardization while deemphasizing specialization. IT managers seeking to match their organization to the values of their firm may utilize the IT organization structure survey instrument exhibited here to do so

    Dark cloud cores and gravitational decoupling from turbulent flows

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    We test the hypothesis that the starless cores may be gravitationally bound clouds supported largely by thermal pressure by comparing observed molecular line spectra to theoretical spectra produced by a simulation that includes hydrodynamics, radiative cooling, variable molecular abundance, and radiative transfer in a simple one-dimensional model. The results suggest that the starless cores can be divided into two categories: stable starless cores that are in approximate equilibrium and will not evolve to form protostars, and unstable pre-stellar cores that are proceeding toward gravitational collapse and the formation of protostars. The starless cores might be formed from the interstellar medium as objects at the lower end of the inertial cascade of interstellar turbulence. Additionally, we identify a thermal instability in the starless cores. Under par ticular conditions of density and mass, a core may be unstable to expansion if the density is just above the critical density for the collisional coupling of the gas and dust so that as the core expands the gas-dust coupling that cools the gas is reduced and the gas warms, further driving the expansion.Comment: Submitted to Ap

    A lack of response of the financial behaviors of biodiversity conservation nonprofits to changing economic conditions

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    The effectiveness of conservation organizations is determined in part by how they adapt to changing conditions. Over the previous decade, economic conditions in the United States (US) showed marked variation including a period of rapid growth followed by a major recession. We examine how biodiversity conservation nonprofits in the US responded to these changes through their financial behaviors, focusing on a sample of 90 biodiversity conservation nonprofits and the largest individual organization (The Nature Conservancy; TNC). For the 90 sampled organizations, an analysis of financial ratios derived from tax return data revealed little response to economic conditions. Similarly, more detailed examination of conservation expenditures and land acquisition practices of TNC revealed only one significant relationship with economic conditions: TNC accepted a greater proportion of conservation easements as donated in more difficult economic conditions. Our results suggest that the financial behaviors of US biodiversity conservation nonprofits are unresponsive to economic conditions

    AN ECONOMIC ANALYSIS OF GENETIC INFORMATION: LEPTIN GENOTYPING IN FED CATTLE

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    The use of genetic knowledge is widespread in crop production but is just recently being utilized in livestock production. This study investigates the economic value to feedlots of a polymorphism in the bovine leptin gene. Previous studies indicate that this polymorphism is associated with fat deposition. Since fed cattle are often priced on a grid that considers both yield and quality grades, fat deposition is an important factor in the value and profitability of fed cattle. Using data from 590 crossbred steers and heifers, we estimate growth curves for relevant biological traits, both with and without genotypic information. Using the resulting functions, we then simulate carcass traits to various days-on-feed and compute the associated profit under three price grids. Maximum profits are determined in an unconstrained profit maximization model and in a model that constrains cattle to be marketed in 45-head "potloads." Results indicate that leptin genotypic knowledge has little impact on optimal days-on-feed but may play a role in valuing feeder cattle. The differences in value of cattle varied by as much as $37 per head between genotypes.genetics, leptin genotype, beef cattle, value of information, Livestock Production/Industries,

    Distribution, habitat associations, and conservation status updates for the pilose crayfish Pacifastacus gambelii (Girard, 1852) and Snake River pilose crayfish Pacifastacus connectens (Faxon, 1914) of the western United States

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    Our study evaluates the distribution, habitat associations, and current conservation status of the Snake River pilose crayfish Pacifastacus connectens (Faxon, 1914) and pilose crayfish Pacifastacus gambelii (Girard, 1852), two little-studied and data-deficient species endemic to the western United States. We first developed a species distribution model (SDM) for the pilose crayfishes based on their historical occurrence records using boosted regression trees and freshwater GIS data layers. We then sampled 163 sites in the summers of 2016 and 2017 within the distribution of these crayfishes, including 50 where these species were observed historically. We next compared our field results to modeled predictions of suitable habitat from the SDM. Our SDM predicted 73 sites (45%) we sampled as suitable for the pilose crayfishes, with a moderate AUC value of 0.824. The pilose crayfishes were generally predicted to occur in larger streams and rivers with less extreme upstream temperature and precipitation seasonality. We found the pilose crayfishes at only 20 (12%) of the 163 total sites we sampled, 14 (20%) of the 73 sites predicted as suitable for them by our SDM, and 12 (24%) of 50 historical sites that we sampled. We found the invasive virile crayfish Faxonius virilis (Hagen, 1870) at 22 sites total and 12 (24%) historical sites for the pilose crayfishes, and we found the “native invader” signal crayfish Pacifastacus leniusculus (Dana, 1852) at 29 sites total and 6 (12%) historical sites for the pilose crayfishes. We subsequently used a single classification tree to identify factors associated with our high rate of false positives for contemporary pilose crayfish distributions relative to our SDM. This classification tree identified the presence of invasive crayfishes, impairment of the benthic community, and sampling method as some of the factors differentiating false positives relative to true positives for the pilose crayfishes. Our study identified the historical distribution and habitat associations for P. connectens and P. gambelii using an SDM and contrasted this prediction to results of contemporary field sampling. We found that the pilose crayfishes have seemingly experienced substantial range declines, attributable to apparent displacement by invasive crayfishes and impairment or change to stream communities and habitat. We recommend increased conservation and management attention to P. connectens and P. gambelii in response to these findings

    California Solar Regatta

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    This Final Design Review report details the research, analysis, and design conducted by a Cal Poly Mechanical Engineering senior project team working on the propulsion system for a solar powered boat. Working in coordination with another senior project team responsible for making the hull, the two teams comprised the Cal Poly team who entered the Sacramento Municipal Utility District (SMUD) 2020 California Solar Regatta Competition. The SMUD Solar Regatta is an annual competition for high school and college students to design and build boats powered by solar power. The solar panels are provided by SMUD, and the battery storage is limited by competition regulations. The scope of this project was to design a propulsion system that would efficiently transfer energy, be easily integrated into the hull design and be competitive in the three races: endurance, slalom, and sprint. This document covers research conducted, objectives for the design, design concepts considered, the chosen final design, manufacturing and verification plans, and project management

    Observations on the Formation of Massive Stars by Accretion

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    Observations of the H66a recombination line from the ionized gas in the cluster of newly formed massive stars, G10.6-0.4, show that most of the continuum emission derives from the dense gas in an ionized accretion flow that forms an ionized disk or torus around a group of stars in the center of the cluster. The inward motion observed in the accretion flow suggests that despite the equivalent luminosity and ionizing radiation of several O stars, neither radiation pressure nor thermal pressure has reversed the accretion flow. The observations indicate why the radiation pressure of the stars and the thermal pressure of the HII region are not effective in reversing the accretion flow. The observed rate of the accretion flow, 0.001 solar masses/yr, is sufficient to form massive stars within the time scale imposed by their short main sequence lifetimes. A simple model of disk accretion relates quenched HII regions, trapped hypercompact HII regions, and photo-evaporating disks in an evolutionary sequence

    A Programmable True Random Number Generator Using Commercial Quantum Computers

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    Random number generators (RNG) are essential elements in many cryptographic systems. True random number generators (TRNG) rely upon sources of randomness from natural processes such as those arising from quantum mechanics phenomena. We demonstrate that a quantum computer can serve as a high-quality, weakly random source for a generalized user-defined probability mass function (PMF). Specifically, QC measurement implements the process of variate sampling according to a user-specified PMF resulting in a word comprised of electronic bits that can then be processed by an extractor function to address inaccuracies due to non-ideal quantum gate operations and other system biases. We introduce an automated and flexible method for implementing a TRNG as a programmed quantum circuit that executes on commercially-available, gate-model quantum computers. The user specifies the desired word size as the number of qubits and a definition of the desired PMF. Based upon the user specification of the PMF, our compilation tool automatically synthesizes the desired TRNG as a structural OpenQASM file containing native gate operations that are optimized to reduce the circuit's quantum depth. The resulting TRNG provides multiple bits of randomness for each execution/measurement cycle; thus, the number of random bits produced in each execution is limited only by the size of the QC. We provide experimental results to illustrate the viability of this approach.Comment: 15 pages, 7 figures, SPIE Defense + Commercial Sensing: Quantum Information Science, Sensing, and Computation X

    The Different Structures of the Two Classes of Starless Cores

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    We describe a model for the thermal and dynamical equilibrium of starless cores that includes the radiative transfer of the gas and dust and simple CO chemistry. The model shows that the structure and behavior of the cores is significantly different depending on whether the central density is either above or below about 10^5 cm-3. This density is significant as the critical density for gas cooling by gas-dust collisions and also as the critical density for dynamical stability, given the typical properties of the starless cores. The starless cores thus divide into two classes that we refer to as thermally super-critical and thermally sub-critical.This two-class distinction allows an improved interpretation of the different observational data of starless cores within a single model.Comment: ApJ in pres
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