9,273 research outputs found
Is there a credibility crisis in strategic management research? Evidence on the reproducibility of study findings
Recent studies report an inability to replicate previously published research, leading some to suggest that scientific knowledge is facing a credibility crisis. In this essay, we provide evidence on whether strategic management research may itself be vulnerable to these concerns. We conducted a study whereby we attempted to reproduce the empirical findings of 88 articles appearing in the Strategic Management Journal using data reported in the articles themselves. About 70% of the studies did not disclose enough data to permit independent tests of reproducibility of their findings. Of those that could be retested, almost one-third reported hypotheses as statistically significant which were no longer so and far more significant results were found to be non-significant in the reproductions than in the opposite direction. Collectively, incomplete reporting practices, disclosure errors, and possible opportunism limit the reproducibility of most studies. Until disclosure standards and requirements change to include more complete reporting and facilitate tests of reproducibility, the strategic management field appears vulnerable to a credibility crisis
Economic benefits of Mt. Cook National Park
Market and non-market valued decisions are associated with New Zealand's system of national parks. The use benefits of Mount Cook National Park are not priced by the market mechanism, whereas many of the inputs necessary to operate and maintain the Park are priced. Estimates of the economic benefits are relevant information when deciding upon the allocation of resources to, and within, a system of national parks.
In 1984, the consumers' surplus for adult New Zealand visitors was about 58. These expenditures give rise to secondary economic benefits and create opportunities for regional development. Visitor expenditures in the Mackenzie Basin area are associated with 6.8 million of additional regional income, and 196 jobs. These effects derive their significance from regional objectives; they are not indicators of the national benefits associated with Mount Cook National Park
Onset of Phase Synchronization in Neurons Conneted via Chemical Synapses
We study the onset of synchronous states in realistic chaotic neurons coupled
by mutually inhibitory chemical synapses. For the realistic parameters, namely
the synaptic strength and the intrinsic current, this synapse introduces
non-coherences in the neuronal dynamics, yet allowing for chaotic phase
synchronization in a large range of parameters. As we increase the synaptic
strength, the neurons undergo to a periodic state, and no chaotic complete
synchronization is found.Comment: to appear in Int. J. Bif. Chao
Simian immunodeficiency virus infection in wild-caught chimpanzees from Cameroon
Simian immunodeficiency viruses (SIVcpz) infecting chimpanzees (Pan troglodytes) in west central Africa are the closest relatives to all major variants of human immunodeficiency virus type 1 ([HIV-1]; groups M, N and O), and have thus been implicated as the source of the human infections; however, information concerning the prevalence, geographic distribution, and subspecies association of SIVcpz still remains limited. In this study, we tested 71 wild-caught chimpanzees from Cameroon for evidence of SIVcpz infection. Thirty-nine of these were of the central subspecies (Pan troglodytes troglodytes), and 32 were of the Nigerian subspecies (Pan troglodytes vellerosus), as determined by mitochondrial DNA analysis. Serological analysis determined that one P. t. troglodytes ape (CAM13) harbored serum antibodies that cross-reacted strongly with HIV-1 antigens; all other apes were seronegative. To characterize the newly identified virus, 14 partially overlapping viral fragments were amplified from fecal virion RNA and concatenated to yield a complete SIVcpz genome (9,284 bp). Phylogenetic analyses revealed that SIVcpzCAM13 fell well within the radiation of the SIVcpzPtt group of viruses, as part of a clade including all other SIVcpzPtt strains as well as HIV-1 groups M and N. However, SIVcpzCAM13 clustered most closely with SIVcpzGAB1 from Gabon rather than with SIVcpzCAM3 and SIVcpzCAM5 from Cameroon, indicating the existence of divergent SIVcpzPtt lineages within the same geographic region. These data, together with evidence of recombination among ancestral SIVcpzPtt lineages, indicate long-standing endemic infection of central chimpanzees and reaffirm a west central African origin of HIV-1. Whether P. t. vellerosus apes are naturally infected with SIVcpz requires further study
Massive pulmonary embolism in patients with extreme bleeding risk: a case series on the successful use of ultrasound-assisted, catheter directed thrombolysis in a district general hospital
This is the final version. Available from the publisher via the DOI in this record.Massive pulmonary embolism (PE), characterised by profound arterial hypotension, is a life-threatening emergency with a
90-day mortality of over 50%. Systemic thrombolysis can signifcantly reduce the risk of death or cardiovascular collapse
in these patients, by around 50%, but these benefts are ofset by a fvefold increased risk of intracranial haemorrhage and
major bleeding, which may limit its use in patients at high risk of catastrophic haemorrhage. We describe a case series of
3 patients presenting with massive PE, each with extreme risk of bleeding and contra-indication to systemic thrombolysis,
treated successfully with ultrasound-assisted, catheter directed thrombolysis (U-ACDT). Our experience of this novel technique using the EkoSonic Endovascular System (Ekos, BTG, London, UK) on carefully selected patients has demonstrated
the potential to improve clinical status in shocked patients, with minimal bleed risk. There have been several clinical studies
evaluating the Ekos system. Both the ULTIMA and SEATTLE II studies have shown signifcant reductions in RV/LV ratio
by CT scanning when compared to standard anticoagulation in patients with intermediate-risk PE, with minimal bleeding
complications. However, there is a pressing need for a randomised trial demonstrating improvement in robust clinical outcomes when comparing U-ACDT to simple anticoagulation. We believe that this case series adds new insight and highlights
the potential of catheter directed thrombolysis in this high-risk patient cohort and consideration should be made to its use
in cases where systemic thrombolysis is felt to be too high ris
Behavior and Weight Loss of Feeder Calves in a Railcar Modified for Feeding and Watering in Transit
The behavior of 164kg Angus and Hereford calves was studied in a double deck 26m x 2.6m jumbo railcar equipped with feed and water. A 4,180 liter water tank positioned in the center of each deck divided the car into four compartments. Fifty head were loaded into the lower and upper forward compartment (252kg/m2floor space], each containing 675kg of hay in racks. The two rear compartments served as quarters for equipment and researchers. Two video cameras were mounted in the upper forward compartment containing calves. Behavior of the calves was monitored, with portions video taped during rail transport from Memphis, Tennessee to Amarillo, Texas (57 hr) in June, 1979. The calves commenced eating and drinking immediately after being loaded in the railcar. Up to 75% of the cattle could lie down while the car was not in motion (14.4 hr of trip]. Calves stood at high speeds (80km/h] on unimproved track but continued to eat, drink and move about. Self and mutual grooming commonly occurred while traveling up to 40km/hr. Railcar temperature and relative humidity ranged from 17.8 to 41.1°C and 54 to 99%, respectively, and was identical to outside. Weight loss for 50 similar calves shipped by truck was 10.6% while rail calves lost 4.5% during truck transport to the railcar (11.3 hr) and 2.1% during rail transport for a total of 6.6%. Average daily gain (ADG) from initial weight to 7 days postshipment was .45kg for rail and -.02kg for truck, but ADG became similar at 30 days indicating full recovery. One truck calf was dead on arrival and 8% of the truck and 5% of the rail calves were treated for shipping fever. Excluding feedcosts, rail transport at 252kg/m 2 floor space costs 30% less per calf than transport in fully loaded trucks
Behavior and Weight Loss of Feeder Calves in a Railcar Modified for Feeding and Watering in Transit
The behavior of Angus and Hereford calves was studied in a double deck 26m x 2.6m jumbo railcar equipped with feed and water. A 4,180-liter water tank positioned in the center of each deck divided the car into four compartments. Fifty heads were loaded into the lower and upper forward compartments (252kg/m2 floor space], each containing 675kg of hay in racks. The two rear compartments served as quarters for equipment and researchers. Two video cameras were mounted in the upper forward compartment containing calves. The behavior of the calves was monitored, with portions video-taped during rail transport from Memphis, Tennessee, to Amarillo, Texas (57 hours) in June 1979. The calves commenced eating and drinking immediately after being loaded in the railcar. Up to 75% of the calves could lie down while the car was not in motion (14.4 hours of the trip]. Calves stood at high speeds (80km/h] on an unimproved track but continued to eat, drink and move about. Self and mutual grooming commonly occur while traveling up to 40km/hr. Railcar temperature and relative humidity ranged from 17.8 to 41.1oC and 54 to 99%, respectively, and were identical to the outside. Weight loss for 50 similar calves shipped by truck was 10.6%, while rail calves lost 4.5% during truck transport to the railcar (11.3 hours] and 2.1% during rail transport for a total of 6.6%. Average daily gain (ADG) from initial weight to 7 days post shipment was .45kg for rail and -.02 kilograms for truck, but ADG became similar at 30 days indicating full recovery. One truck calf was dead on arrival, and 8% of the truck and 5% of the rail calves were treated for shipping fever. Excluding feed costs, rail transport at 252kglm 2-floor space costs 30% less per calf than transport in fully loaded trucks
Predicting Ares I Reaction Control System Performance by Utilizing Analysis Anchored with Development Test Data
The Ares I launch vehicle is an integral part of NASA s Constellation Program, providing a foundation for a new era of space access. The Ares I is designed to lift the Orion Crew Module and will enable humans to return to the Moon as well as explore Mars.1 The Ares I is comprised of two inline stages: a Space Shuttle-derived five-segment Solid Rocket Booster (SRB) First Stage (FS) and an Upper Stage (US) powered by a Saturn V-derived J-2X engine. A dedicated Roll Control System (RoCS) located on the connecting interstage provides roll control prior to FS separation. Induced yaw and pitch moments are handled by the SRB nozzle vectoring. The FS SRB operates for approximately two minutes after which the US separates from the vehicle and the US Reaction Control System (ReCS) continues to provide reaction control for the remainder of the mission. A representation of the Ares I launch vehicle in the stacked configuration and including the Orion Crew Exploration Vehicle (CEV) is shown in Figure 1. Each Reaction Control System (RCS) design incorporates a Gaseous Helium (GHe) pressurization system combined with a monopropellant Hydrazine (N2H4) propulsion system. Both systems have two diametrically opposed thruster modules. This architecture provides one failure tolerance for function and prevention of catastrophic hazards such as inadvertent thruster firing, bulk propellant leakage, and over-pressurization. The pressurization system on the RoCS includes two ambient pressure-referenced regulators on parallel strings in order to attain the required system level single Fault Tolerant (FT) design for function while the ReCS utilizes a blow-down approach. A single burst disk and relief valve assembly is also included on the RoCS to ensure single failure tolerance for must-not-occur catastrophic hazards. The Reaction Control Systems are designed to support simultaneously firing multiple thrusters as require
Forest Economics and Policy
The economics of deriving raw materials from forests is examined. Competitive markets are consistent with the notion of efficiency, although they may not produce results that are fair. Sustainability as an alternative criterion suffers from problems of commensurability and an inability to identify preferred options when a choice between alternative patterns of use is possible. Given a choice among a number of sustainable use rates, competitive markets satisfy both criteria. Institutional arrangements are significant variables in forestry policy because they provide a basis for competitive markets and they determine the distribution of benefits and costs associated with use.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55468/1/Hull B - 1988 - Forest Economics - NZ Forestry.pd
The Value of a Forest: A Critique of the Groome and Associates IRR Method
The Groome and Associates Internal Rate of Return method for estimating the value of a standing forest is compelling in its simplicity. A forest manager need only be aware of current lumber prices, aware of harvesting cost, and able to estimate the average rate of growth in the value of a tree about to be planted. The technique also produces consistent results. Any forest manager should arrive at the same estimate of value for any forest. However, the simplicity of the method disguises several important errors. The age at which trees are harvested influences a forest's value. If trees are cut in the wrong year, the value of the forest is reduced. Determining cutting year is properly an explicit part of estimating forest value, but is excluded from the GA method. By contrast, net present value easily calculates optimal cutting year.http://deepblue.lib.umich.edu/bitstream/2027.42/61262/1/Hull_B_1985_Working_Paper_32_Value_of_a_Forest.pd
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