Global commodity chains and the development of poor fisherfolk in Uganda

The Ugandan fishery, heavily influenced by the emergence of global markets, is extremely dynamic. In recent years a major export trade, principally in Nile perch fillets from Lake Victoria, has expanded markedly. The growth of this factory based processing industry has had a marked impact on the pre-existing artisanal fishery, which has become increasingly dependent on supplying the export market instead of its traditional local small-scale markets. The industrial fishery developed as a response to the liberalisation of the management of the Ugandan economy and the consequent opening up of the export markets in North America and Europe. The emergence of the export industry has resulted in the creation of a dual structure in the fisheries sector, with the Nile perch catching and processing chain operating to European standards, whilst the artisanal sub-sector still utilises traditional methods. This dual structure is a potential source of disadvantage to the artisanal fishery which has command over fewer financial assets than the export fishery.

A method for analysing operational complexity in supply chains

This paper proposes a method for analysing the operational complexity in supply chains by using an entropic measure based on information theory. The proposed approach estimates the operational complexity at each stage of the supply chain and analyses the changes between stages. In this paper a stage is identified by the exchange of data and/or material. Through analysis the method identifies the stages where the operational complexity is both generated and propagated (exported, imported, generated or absorbed). Central to the method is the identification of a reference point within the supply chain. This is where the operational complexity is at a local minimum along the data transfer stages. Such a point can be thought of as a 'sink' for turbulence generated in the supply chain. Where it exists, it has the merit of stabilising the supply chain by attenuating uncertainty. However, the location of the reference point is also a matter of choice. If the preferred location is other than the current one, this is a trigger for management action. The analysis can help decide appropriate remedial action. More generally, the approach can assist logistics management by highlighting problem areas. An industrial application is presented to demonstrate the applicability of the method. © 2013 Operational Research Society Ltd. All rights reserved.

Unsteady simulation paradigms for trailing edge ejection

Tucker

The search for the IFN-gamma receptor in fish: Functional and expression analysis of putative binding and signalling chains in rainbow trout Oncorhynchus mykiss

Interferons (IFNs), consisting of three major subfamilies, type I, type II (gamma) and type III (lambda) IFN, activate vertebrate antiviral defences once bound to their receptors. The three IFN subfamilies bind to different receptors, IFNAR1 and IFNAR2 for type I IFNs, IFN gamma R1 and IFN gamma R2 for type II IFN, and IL-28R1 and IL-10R2 for type III IFNs. In fish, although many types I and II IFN genes have been cloned, little is known about their receptors. In this report, two putative IFN-gamma receptor chains were identified and sequenced in rainbow trout (Oncorhynchus mykiss), and found to have many common characteristics with mammalian type II IFN receptor family members. The presented gene synteny analysis, phylogenetic tree analysis and ligand binding analysis all suggest that these molecules are the authentic IFN gamma Rs in fish. They are widely expressed in tissues, with IFN gamma R1 typically more highly expressed than IFN gamma R2. Using the trout RTG-2 cell line it was possible to show that the individual chains could be differentially modulated, with rIFN-gamma and rIL-1 beta down regulating IFN gamma R1 expression but up regulating IFN gamma R2 expression. Overexpression of the two receptor chains in RTG-2 cells revealed that the level of IFN gamma R2 transcript was crucial for responsiveness to rIFN-gamma, in terms of inducing gamma IP expression. Transfection experiments showed that the two putative receptors specifically bound to rIFN-gamma. These findings are discussed in the context of how the IFN gamma R may bind IFN-gamma in fish and the importance of the individual receptor chains to signal transduction. (c) 2009 Elsevier Ltd. All rights reserved.

Molecular cloning and characterization of common carp (Cyprinus carpio L.) TCR gamma and CD3 gamma/delta chains

Partial cDNA sequences of TCR gamma and CD3 gamma/delta were isolated from the thymus of common carp (Cyprinus carpio L.) by the method of suppression subtractive hybridization (SSH). Subsequently the full length cDNAs of carp TCR gamma and CD3 gamma/delta were obtained by means of 3' RACE and 5' RACE, respectively. The full length of carp TCR gamma chain is 1368 bp and encodes 326 amino acids including a signal peptide region of 19 amino acids and a transmembrane region of 23 amino acids at the C-terminal region from aa 291 to 313. The V region of carp TCR gamma contains 109 amino acids, the core motif FGXG in J segment was also found in carp TCR gamma. The C region of carp TCR gamma contains the characteristic CX6PX6WX45C motif. The CP region of carp TCR C gamma contains 37 amino acids. The full length of carp CD3 gamma/delta is 790 bp and encodes 175 amino acids including a signal peptide region of 17 amino acids and a transmembrane region of 23 amino acids from aa 93 to 115. Similar to other known CD3 gamma/delta s, four cysteine residues in the extracellular domain and an immunoreceptor tyrosine-based activation motif ITAM (YxxL/Ix6-8YxxL/I) in the intracellular domain are also included in carp CD3 gamma/delta. Differing from other known CD3 gamma/delta s, carp CD3 gamma/delta tacks the CXXCXE motif in the extracellular domain. RTPCR analysis demonstrated that the expression of TCR gamma gene was mainly in the thymus and gill of 6-month carp, but in 18-month carp, TCR gamma gene was detected in all the examined tissues. The expression of CD3 gamma/delta gene was detected in all examined tissues of 6 and 18-month carp; among them, the highest expression level was in the thymus of 6-month carp. In situ hybridization showed that CD3 gamma/delta-expressing cells were widely distributed in the head kidney, spleen and kidney of carp, whereas in the thymus, they were densely distributed in the lymphoid outer zone and scattered in the epithelioid inner zone. (c) 2007 Published by Etsevier Ltd.

Mass chains with passive interconnection: Complex iterative maps and scalability

This paper introduces the problem of passive control of a chain of N identical masses in which there is an identical passive connection between neighbouring masses and a similar connection to a movable point. The problem arises in the design of multi-storey buildings which are subjected to earthquake disturbances, but applies in other situations, for example vehicle platoons. The paper will study the scalar transfer functions from the disturbance to a given intermass displacement. It will be shown that these transfer functions can be conveniently represented in the form of complex iterative maps and that these maps provide a method to establish boundedness in N of the H ∞-norm of these transfer functions for certain choices of interconnection impedance. © 2013 IEEE.

DTADH and quantum critical phenomena caused by anisotropy and external magnetic field for spin-1/2 Heisenberg diamond chains

Using the transfer matrix renormalization group (TMRG) method, we study the connection between the first derivative of the thermal average of driving-term Hamiltonian (DTADH) and the trace of quantum critical behaviors at finite temperatures. Connecting with the exact diagonalization method, we give the phase diagrams and analyze the properties of each phase for both the ferromagnetic and anti-ferromagnetic frustrated J(3) anisotropy diamond chain models. The finite-temperature scaling behaviors near the critical regions are also investigated. Further, we show the critical behaviors driven by external magnetic field, analyze the formation of the 1/3 magnetic plateau and the influence of different interactions on those critical points for both the ferrimagnetic and anti-ferromagnetic distorted diamond chains.

Optical study of lateral carrier transfer in (In,Ga)As/GaAs quantum-dot chains

We have studied the lateral carrier transfer in a specially designed quantum dot chain structure by means of time-resolved photoluminescence (PL) and polarization PL. The PL decay time increases with temperature, following the T-1/2 law for the typical one-dimensional quantum system. The decay time depends strongly on the emission energy: it decreases as the photon energy increases. Moreover, a strong polarization anisotropy is observed. These results are attributed to the efficient lateral transfer of carriers along the chain direction. (c) 2008 American Institute of Physics.

Comparative study of optical properties between quantum dot chains band quantum dots

A comparative study of the steady-state and transient optical properties was made between InGaAs/GaAs quantum do chains (QDCs) and quantum dots (QDs). It was found that the photoluminescence (PL) decay time of QDCs exhibited a strong photon energy dependence, while it was less sensitive in QDs. The PL decay time increased much faster with the excitation power in the QDCs than that in QDs. When the excitation power was large enough, the PL decay time tended to be saturated. In addition, it was also found that the PL rise time was much shorter in QDCs than in QDs. All these experimental results show that there is a strong carrier coupling along the chain direction in the QD chain structure. The polarization PL measurements further confirm the carrier transfer process along the chain direction.