2,852 research outputs found
Valuing Limited Information in Decision Making Under Uncertainty
Fresh Juice Inc. (FJI) is in the process of determining whether they should launch a new fruit juice in a market that has been relatively stagnant for the last 15 years. Management of FJI is faced with uncertainty surrounding market share, market size, price, and competitor entry. In addition, FJI has the ability to chose between alternative production processes; this choice directly affects the likelihood the investment will return a positive Net Present Value. This case teaches students how to develop a stochastic simulation models given limited information to analyze risk investment decisions.: simulation, uncertainty, strategic management, flexibility, limited information, investment analysis
Ultrasound enhancement of microfiltration performance for natural organic matter removal
Sonication of water at 1500 W power prior to microfiltration showed that short sonication times (60 s) gave a reduced flux decline. It is suggested that a less potent, smaller molecular form of the natural organic matter (NOM) was produced by sonication. Longer sonication times diminished this beneficial effect. This may be due to the formation of aggregates or compounds that are more readily adsorbed on the membrane. Where the sonication was preceded by an alum treatment, the flux loss showed a regular decrease with longer sonication times. It is suggested that the effects of sonication on the alum flocs and on the flocs; NOM interactions may play a critical role in regulating the flux. Where sand was present on sonication at 800 and 1400 W, the cavitational energy was focussed on adsorbed organic material, resulting in more efficient destruction and the formation of compounds that counteracted the flux enhancement
Scorecarding and Heat Mapping: Tools and Concepts for Assessing Strategic Uncertainty
The dramatic changes occurring throughout the agriculture industry are creating new and different uncertainties that result from a turbulent business climate. The objective of this paper is to present a methodology to understand, assess and evaluate, and manage strategic uncertainty. The approach is to present a mental model that frames assessment of strategic uncertainty from a potential and exposure perspective. Scorecarding and heat mapping assessment tools operationalize the mental model. Participants in an executive agribusiness educational workshop applied this mental model and the assessment tools to one of three hypothetical seed companies. The participants then provided an evaluation of the usefulness and effectiveness of uncertainty scorecarding and heat mapping.Uncertainty, scorecarding, strategic uncertainty, heat mapping, potential, exposure, likelihood, Risk and Uncertainty,
FRESH VEGETABLE PRICE LINKAGE BETWEEN GROWER/SHIPPERS, WHOLESALERS AND RETAILERS
This study focused on the transmission of price adjustments between grower/shippers and wholesalers and between wholesale handlers and retailers of nine fresh vegetables (only the results associated with bell peppers are reported in this paper). Results among the nine vegetable products were not consistent with respect to the magnitude of adjustments or the time periods involved in the adjustments. In response to wholesale price changes, upward price adjustments at the retail level occur more quickly than do downward price adjustments. Price transmission relationships also varied among the vegetable products between the wholesaler and grower. Overall, the results indicate that factors in addition to changes in upstream prices are impacting retailers' and wholesalers' pricing decisions.Demand and Price Analysis,
Role of Mechanical Bowel Preparation and Perioperative Antibiotics in Pediatric Pull-Through Procedures
Background
There are no clear guidelines for the use of mechanical bowel preparation and postoperative antibiotics in children undergoing elective colorectal pull-through surgery. The objective of this study was to determine whether preoperative bowel preparation administration or duration of postoperative antibiotics impacted the rate of complications after elective pediatric pull-through surgery.
Materials and methods
Patients aged <18 y who underwent a pull-through procedure between 2011 and 2017 were retrospectively identified. Patient data included diagnosis, procedure, administration of mechanical bowel preparation, and duration of perioperative intravenous (IV) antibiotics. Outcomes of interest included surgical site infections and anastomotic complications.
Results
A total of 180 patients met inclusion criteria, of which 47.2% received mechanical bowel preparation. The combined rate of infectious and anastomotic complications was 12.2%. There was no significant difference in combined complication rate among those receiving bowel preparation compared with those who did not (14.1% versus 10.5%, P = 0.46). Administration of bowel preparation in the perineal anoplasty subgroup was associated with higher rates of wound infection (33.3% versus 3.3%, P = 0.05). One hundred five patients (58.3%) received perioperative IV antibiotics for â€24 h. This group had similar rates of complications (13.3%) compared with those receiving IV antibiotics for longer than 24 h (11.6%, P = 0.74).
Conclusions
Although mechanical bowel preparation did not affect the overall complication rate for pull-through procedures, it was associated with more wound infections in those undergoing perineal anoplasty. Duration of postoperative IV antibiotics was not significantly associated with the rate of wound and anastomotic complications
Coulomb blockade in an atomically thin quantum dot coupled to a tunable Fermi reservoir
Gate-tunable quantum-mechanical tunnelling of particles between a quantum
confined state and a nearby Fermi reservoir of delocalized states has
underpinned many advances in spintronics and solid-state quantum optics. The
prototypical example is a semiconductor quantum dot separated from a gated
contact by a tunnel barrier. This enables Coulomb blockade, the phenomenon
whereby electrons or holes can be loaded one-by-one into a quantum dot.
Depending on the tunnel-coupling strength, this capability facilitates single
spin quantum bits or coherent many-body interactions between the confined spin
and the Fermi reservoir. Van der Waals (vdW) heterostructures, in which a wide
range of unique atomic layers can easily be combined, offer novel prospects to
engineer coherent quantum confined spins, tunnel barriers down to the atomic
limit or a Fermi reservoir beyond the conventional flat density of states.
However, gate-control of vdW nanostructures at the single particle level is
needed to unlock their potential. Here we report Coulomb blockade in a vdW
heterostructure consisting of a transition metal dichalcogenide quantum dot
coupled to a graphene contact through an atomically thin hexagonal boron
nitride (hBN) tunnel barrier. Thanks to a tunable Fermi reservoir, we can
deterministically load either a single electron or a single hole into the
quantum dot. We observe hybrid excitons, composed of localized quantum dot
states and delocalized continuum states, arising from ultra-strong
spin-conserving tunnel coupling through the atomically thin tunnel barrier.
Probing the charged excitons in applied magnetic fields, we observe large
gyromagnetic ratios (~8). Our results establish a foundation for engineering
next-generation devices to investigate either novel regimes of Kondo physics or
isolated quantum bits in a vdW heterostructure platform.Comment: Published in Nature Nanotechnology. 7 pages + 14 supplementary
information pages. 14 figure
Serverification of Molecular Modeling Applications: the Rosetta Online Server that Includes Everyone (ROSIE)
The Rosetta molecular modeling software package provides experimentally
tested and rapidly evolving tools for the 3D structure prediction and
high-resolution design of proteins, nucleic acids, and a growing number of
non-natural polymers. Despite its free availability to academic users and
improving documentation, use of Rosetta has largely remained confined to
developers and their immediate collaborators due to the code's difficulty of
use, the requirement for large computational resources, and the unavailability
of servers for most of the Rosetta applications. Here, we present a unified web
framework for Rosetta applications called ROSIE (Rosetta Online Server that
Includes Everyone). ROSIE provides (a) a common user interface for Rosetta
protocols, (b) a stable application programming interface for developers to add
additional protocols, (c) a flexible back-end to allow leveraging of computer
cluster resources shared by RosettaCommons member institutions, and (d)
centralized administration by the RosettaCommons to ensure continuous
maintenance. This paper describes the ROSIE server infrastructure, a
step-by-step 'serverification' protocol for use by Rosetta developers, and the
deployment of the first nine ROSIE applications by six separate developer
teams: Docking, RNA de novo, ERRASER, Antibody, Sequence Tolerance,
Supercharge, Beta peptide design, NCBB design, and VIP redesign. As illustrated
by the number and diversity of these applications, ROSIE offers a general and
speedy paradigm for serverification of Rosetta applications that incurs
negligible cost to developers and lowers barriers to Rosetta use for the
broader biological community. ROSIE is available at
http://rosie.rosettacommons.org
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