3,823 research outputs found
Why Supply Chain Collaboration Fails: The Socio-Structural View Of Resistance To Collaboration Strategies
Purpose
The relational view posits that supply chain integration can be a source of competitive advantage. Few firms, however, successfully co-create value to attain supernormal relational rents. We therefore elaborate theory regarding the reasons why collaboration strategies fail.
Design/methodology/approach
This study employs a quasi-longitudinal, multi-case interview methodology to explore the reasons why collaboration strategies fail to deliver intended results. We interviewed managers at 49 companies in Period 1 and managers at 57 companies in Period 2. Fifteen companies participated in both rounds of interviews.
Findings
This paper builds and describes a taxonomy of relational resistors. We then explore how sociological and structural resistors reinforce each other to undermine collaborative behavior. Specifically, the interplay among resistors 1) obscures the true sources of resistance, 2) exacerbates a sense of vulnerability to non-collaborative behavior that reduces the willingness to invest in relational architecture, and 3) inhibits the development of essential relational skills and organizational routines.
Originality/value
This research identifies and describes the behaviors and processes that impede successful supply chain alliances. By delving into the interplay among relational resistors, the research explains the detail and nuance of inter-firm rivalry and supply chain complexity. Ultimately, it is the re-enforcing nature of various resistors that make it so difficult for firms have to realize relational rents
Vacuum ultraviolet instrumentation for solar irradiance and thermospheric airglow
A NASA sounding rocket experiment was developed to study the solar extreme ultraviolet (EUV) spectral irradiance and its effect on the upper atmosphere. Both the solar flux and the terrestrial molecular nitrogen via the Lyman-Birge-Hopfield bands in the far ultraviolet (FUV) were measured remotely from a sounding rocket on October 27, 1992. The rocket experiment also includes EUV instruments from Boston University (Supriya Chakrabarti), but only the National Center for Atmospheric Research (NCAR)/University of Colorado (CU) four solar instruments and one airglow instrument are discussed here. The primary solar EUV instrument is a 1/4 meter Rowland circle EUV spectrograph which has flown on three rockets since 1988 measuring the solar spectral irradiance from 30 to 110 nm with 0.2 nm resolution. Another solar irradiance instrument is an array of six silicon XUV photodiodes, each having different metallic filters coated directly on the photodiodes. This photodiode system provides a spectral coverage from 0.1 to 80 nm with about 15 nm resolution. The other solar irradiance instrument is a silicon avalanche photodiode coupled with pulse height analyzer electronics. This avalanche photodiode package measures the XUV photon energy providing a solar spectrum from 50 to 12,400 eV (25 to 0.1 nm) with an energy resolution of about 50 eV. The fourth solar instrument is an XUV imager that images the sun at 17.5 nm with a spatial resolution of 20 arc-seconds. The airglow spectrograph measures the terrestrial FUV airglow emissions along the horizon from 125 to 160 nm with 0.2 nm spectral resolution. The photon-counting CODACON detectors are used for three of these instruments and consist of coded arrays of anodes behind microchannel plates. The one-dimensional and two-dimensional CODACON detectors were developed at CU by Dr. George Lawrence. The pre-flight and post-flight photometric calibrations were performed at our calibration laboratory and at the Synchrotron Ultraviolet Radiation Facility (SURF) at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland
Insurance type and sepsis-associated hospitalizations and sepsis-associated mortality among US adults: A retrospective cohort study
Ozone depletion potential of CH_3Br
The ozone depletion potential (ODP) of methyl bromide (CH_3Br) can be determined by combining the modelâcalculated bromine efficiency factor (BEF) for CH_3Br and its atmospheric lifetime. This paper examines how changes in several key kinetic data affect BEF. The key reactions highlighted in this study include the reaction of BrO + HO_2, the absorption cross section of HOBr, the absorption cross section and the photolysis products of BrONO_2, and the heterogeneous conversion of BrONO_2 to HOBr and HNO_3 on aerosol particles. By combining the calculated BEF with the latest estimate of 0.7 year for the atmospheric lifetime of CH_3Br, the likely value of ODP for CH_3Br is 0.39. The modelâcalculated concentration of HBr (âŒ0.3 pptv) in the lower stratosphere is substantially smaller than the reported measured value of about 1 pptv. Recent publications suggested models can reproduce the measured value if one assumes a yield for HBr from the reaction of BrO + OH or from the reaction of BrO + HO_2. Although the DeMore et al. [1997] evaluation concluded any substantial yield of HBr from BrO + HO_2 is unlikely, for completeness, we calculate the effects of these assumed yields on BEF for CH_3Br. Our calculations show that the effects are minimal: practically no impact for an assumed 1.3% yield of HBr from BrO + OH and 10% smaller for an assumed 0.6% yield from BrO + HO_2
Normal histone modifications on the inactive X chromosome in ICF and Rett syndrome cells: implications for methyl-CpG binding proteins
BACKGROUND: In mammals, there is evidence suggesting that methyl-CpG binding proteins may play a significant role in histone modification through their association with modification complexes that can deacetylate and/or methylate nucleosomes in the proximity of methylated DNA. We examined this idea for the X chromosome by studying histone modifications on the X chromosome in normal cells and in cells from patients with ICF syndrome (Immune deficiency, Centromeric region instability, and Facial anomalies syndrome). In normal cells the inactive X has characteristic silencing type histone modification patterns and the CpG islands of genes subject to X inactivation are hypermethylated. In ICF cells, however, genes subject to X inactivation are hypomethylated on the inactive X due to mutations in the DNA methyltransferase (DNMT3B) genes. Therefore, if DNA methylation is upstream of histone modification, the histones on the inactive X in ICF cells should not be modified to a silent form. In addition, we determined whether a specific methyl-CpG binding protein, MeCP2, is necessary for the inactive X histone modification pattern by studying Rett syndrome cells which are deficient in MeCP2 function. RESULTS: We show here that the inactive X in ICF cells, which appears to be hypomethylated at all CpG islands, exhibits normal histone modification patterns. In addition, in Rett cells with no functional MeCP2 methyl-CpG binding protein, the inactive X also exhibits normal histone modification patterns. CONCLUSIONS: These data suggest that DNA methylation and the associated methyl-DNA binding proteins may not play a critical role in determining histone modification patterns on the mammalian inactive X chromosome at the sites analyzed
On positivity of Ehrhart polynomials
Ehrhart discovered that the function that counts the number of lattice points
in dilations of an integral polytope is a polynomial. We call the coefficients
of this polynomial Ehrhart coefficients, and say a polytope is Ehrhart positive
if all Ehrhart coefficients are positive (which is not true for all integral
polytopes). The main purpose of this article is to survey interesting families
of polytopes that are known to be Ehrhart positive and discuss the reasons from
which their Ehrhart positivity follows. We also include examples of polytopes
that have negative Ehrhart coefficients and polytopes that are conjectured to
be Ehrhart positive, as well as pose a few relevant questions.Comment: 40 pages, 7 figures. To appear in in Recent Trends in Algebraic
Combinatorics, a volume of the Association for Women in Mathematics Series,
Springer International Publishin
Prevention effects on trajectories of African American adolescents\u27 exposure to interparental conflict and depressive symptoms.
The present study investigates the trajectory of children\u27s exposure to interparental conflict during adolescence, its effects on adolescents\u27 psychological adjustment, as well as the ability of a family-centered prevention program to alter this trajectory. A total of 331 African American couples with an adolescent or preadolescent child participated in a randomized control trial of the Promoting Strong African American Families program, a newly developed program targeting couple and cocaregiving processes. Using a multi-informant, latent growth curve approach, child exposure to interparental conflict during adolescence was found to be stable over a period of 2 years among families in the control group, but significantly declined among families in the treatment condition. Rates of change were significantly different between intervention and control groups based on parents\u27 report of youth exposure to interparental conflict, but not for child\u27s report. Structural equation models found trajectory parameters of interparental conflict predicted changes in adolescent depressive symptoms, with increasing rates of changes in conflict associated with increases in adolescent internalizing symptoms over the 2-year duration of the study. Finally, a significant indirect effect was identified linking treatment, changes in parents\u27 reports of child exposure to interparental conflict, and adolescent depressive symptoms. The implications for research and intervention are discussed
Knowledge Translation Consensus Conference: Research Methods
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72708/1/j.1553-2712.2007.tb02378.x.pd
Perspectives of choice and control in daily life for people following brain injury: A qualitative systematic review and meta-synthesis
Background and Objective: Acquired brain injury (ABI) can result in considerable life changes. Having choice and control over daily life is valued by people following ABI. This meta-synthesis will analyse and integrate international research exploring perspectives of choice and control in daily life following ABI. Methods: Databases were searched from 1980 to 13 January 2022 for eligible qualitative studies. After duplicates were removed, 22,768 studies were screened by title and abstract, and 241 studies received full-text assessment with 56 studies included after pearling. Study characteristics and findings were extracted that related to personal perspectives on choice and control by people with an ABI (including author interpretation and quotes). Data from each study were coded and then segments of coded data across the studies were compared to create multiple broad categories. Findings: Findings were then reduced from categories into 3 overarching themes with 12 subthemes. These themes were: (1) feeling like a second-class citizen; (2) reordering life and (3) choosing a path. Participants with an ABI tussled between their feelings of loss following brain injury and their thinking about how they start to regain control and become agents of their own choices. The themes describe their sense of self, their changed self and their empowered self in relation to âchoice and controlâ. Conclusions: Re-engaging with choice and control after ABI is dynamic and can be challenging. Health professionals and supporters need to facilitate a gradual and negotiated return to agency for people following ABI. A sensitive and person-centred approach is needed that considers the readiness of the person with ABI to reclaim choice and control at each stage of their recovery. Clear service or process indicators that are built on lived experience research are needed to facilitate changes in service delivery that are collaborative and inclusive. Patient or Public Contribution: This review included the voices of 765 people living with ABI and was conducted by a diverse team of allied health professionals with practice knowledge and research experience with people following ABI. Twenty-nine of the 56 included studies had participants contributing to their design or analysis
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