Exclusivity of Agrifood Supply Chains: Seven Fundamental Economic Characteristics

The IFAMR is published by the International Food and Agribusiness Management Association. IFAMA. www.ifama.orgagrifood supply chains, exclusive economic characteristics, risk, market power, globalization, Agribusiness, Demand and Price Analysis, Research and Development/Tech Change/Emerging Technologies, Risk and Uncertainty, Q130,

Scheduling unit processing time arc shutdown jobs to maximize network flow over time: complexity results

We study the problem of scheduling maintenance on arcs of a capacitated network so as to maximize the total flow from a source node to a sink node over a set of time periods. Maintenance on an arc shuts down the arc for the duration of the period in which its maintenance is scheduled, making its capacity zero for that period. A set of arcs is designated to have maintenance during the planning period, which will require each to be shut down for exactly one time period. In general this problem is known to be NP-hard. Here we identify a number of characteristics that are relevant for the complexity of instance classes. In particular, we discuss instances with restrictions on the set of arcs that have maintenance to be scheduled; series parallel networks; capacities that are balanced, in the sense that the total capacity of arcs entering a (non-terminal) node equals the total capacity of arcs leaving the node; and identical capacities on all arcs

DNA-based memory device and method of reading and writing same

The present invention is directed to a memory device having very high storage density capability. In general, the memory device includes an array of individual memory cells which store information that is assigned a value based on the molecular contents of the memory cell. In a preferred embodiment, the molecules utilized for storing information in the memory cells may be single-strand polynucleotides, for instance single-strand oligonucleotides of between about 5 and about 20 monomer units. The present invention is also directed to methods and systems useful for writing and reading the molecular-based memory devices. In particular, the devices may be written and read via modified atomic force microscopy processes

DNA-Based Memory Device and Method of Reading and Writing Same

The present invention is directed to a memory device having very high storage density capability. In general, the memory device includes an array of individual memory cells which store information that is assigned a value based on the molecular contents of the memory cell. In a preferred embodiment, the molecules utilized for storing information in the memory cells may be single-strand polynucleotides, for instance single-strand oligonucleotides of between about 5 and about 20 monomer units. The present invention is also directed to methods and systems useful for writing and reading the molecular-based memory devices. In particular, the devices may be written and read via modified atomic force microscopy processes

Wind-tunnel free-flight investigation of a supersonic persistence fighter

Wind-tunnel free-flight tests have been conducted in the Langley 30- by 60-Foot Wind Tunnel to examine the high-angle-of-attack stability and control characteristics and control law design of a supersonic persistence fighter (SSPF) at 1 g flight conditions. In addition to conventional control surfaces, the SSPF incorporated deflectable wingtips (tiperons) and pitch and yaw thrust vectoring. A direct eigenstructure assignment technique was used to design control laws to provide good flying characteristics well into the poststall angle-of-attack region. Free-flight tests indicated that it was possible to blend effectively conventional and unconventional control surfaces to achieve good flying characteristics well into the poststall angle-of-attack region

Evaluierung praxisorientierter Ökolandbauforschung

Evaluierung praxisorientierter Ökolandbauforschung soll die Praxisrelevanz/-wirkung und die Beiträge für eine Weiterentwicklung des Ökolandbaus bewerten. Dabei ist sowohl der besondere Aufwand praxisorientierter Forschung als auch der Erfolg in der Praxis zu berücksichtigen. Die Kombination aus einer Selbstdokumentation der Wissenschaftler und einer externen Qualitätskontrolle auf Basis breiter Praxisbeteiligung, stellt das geeignete Instrumentarium dar, muss jedoch noch weiter operationalisiert werden

Cholecystogastric fistula: a brief report and review of the literature.

Cholecystogastric fistula is a rare, life-threatening complication of cholelithiasis that presents a difficult challenge to the surgeon when it occurs in elderly and co-morbid patients. Following a case of a 68-year-old female who presented with a short history of epigastric pain and vomiting, and in whom a cholecystogastric fistula was identified on abdominal computed tomography and confirmed on upper gastrointestinal endoscopy, we performed a systematic review of the literature on the management of cholecystogastric fistula. Our patient underwent laparotomy without excision of the fistula nor cholecystectomy and had an uncomplicated post-operative course. Surgical management using an open approach remains the mainstay of treatment of cholecystogastric fistula although laparoscopic techniques are used with increasing success. Surgical closure of the fistula is not always necessary. Improved surgical techniques including the use of laparoscopic surgery have led to improved outcomes in the management of cholecystogastric fistula