9,708 research outputs found
Subsistence food production and marketing in Papua New Guinea : a research paper presented in partial fulfilment of the requirements for the degree of Master in Philosophy in Development Studies at Massey University
Agriculture is the main component of the economic sector of the Less Developed Countries (LDC's) of Asia, Africa and Latin America. In most of these countries, which includes Papua New Guinea (PNG), subsistence agriculture dominates despite the tremendous advances in agricultural technology elsewhere, especially in Developed Countries, in the course of the twentieth century. The characteristic feature of these subsistence farms is low productivity which means small, if any, production surplus over consumption, which results in very little trade between the agriculture sector and other sectors of the country. In LDC's, this has often led to declining food production and increased dependence on imported food as the bulk of domestic food supply is produced by the subsistence sector. In PNG, very similar trends are noted.
This paper examines some issues affecting smallholder agriculture and implications for increasing agricultural productivity in PNG. Specifically, the research problem and the focus of this study is firstly, how to increase subsistence food production and secondly, how to effectively move the rural surplus to urban consumers where it is required.
To increase productivity, LDC's are faced with two choices; extend land area under cultivation if land is available or improve agricultural technology if land is scarce. While PNG is relatively well endowed with land (more than four times the average for developing countries) , much of the land is too mountainous to convert to arable land, with only less than 0.3 per cent of the land used for annual crops and grazing. The choice of strategy thus is determined by land.
This paper shows that the PNG government has under-invested in agriculture, particularly subsistence agriculture. Further investment in research and technology is required, focusing especially on their farming systems. Traditional farmers are not traditionalist by choice. Agricultural techniques have been developed over centuries, through years of accumulated experience of generations of farmers. Extensive literature in agriculture economics show that traditional farmers cannot normally adopt technological innovations unless the circumstances in which they operate are first changed.
The important role of marketing in economic development is also underplayed. It is a common fallacy to assume that markets when left to their own devices can lead to increased productivity and efficiency within the distribution system. Government intervention is also necessary in marketing to achieve social goals of self sufficiency in food production. This study attempts to demonstrate that given the right incentives, mostly institutional and technological, subsistence food production can be increased in PNG
Calibration Wizard: A Guidance System for Camera Calibration Based on Modelling Geometric and Corner Uncertainty
It is well known that the accuracy of a calibration depends strongly on the
choice of camera poses from which images of a calibration object are acquired.
We present a system -- Calibration Wizard -- that interactively guides a user
towards taking optimal calibration images. For each new image to be taken, the
system computes, from all previously acquired images, the pose that leads to
the globally maximum reduction of expected uncertainty on intrinsic parameters
and then guides the user towards that pose. We also show how to incorporate
uncertainty in corner point position in a novel principled manner, for both,
calibration and computation of the next best pose. Synthetic and real-world
experiments are performed to demonstrate the effectiveness of Calibration
Wizard.Comment: Oral presentation at ICCV 201
Hybrid quantum device with nitrogen-vacancy centers in diamond coupled to carbon nanotubes
We show that nitrogen-vacancy (NV) centers in diamond interfaced with a
suspended carbon nanotube carrying a dc current can facilitate a
spin-nanomechanical hybrid device. We demonstrate that strong magnetomechanical
interactions between a single NV spin and the vibrational mode of the suspended
nanotube can be engineered and dynamically tuned by external control over the
system parameters. This spin-nanomechanical setup with strong, \emph{intrinsic}
and \emph{tunable} magnetomechanical couplings allows for the construction of
hybrid quantum devices with NV centers and carbon-based nanostructures, as well
as phonon-mediated quantum information processing with spin qubits.Comment: Selected by PRL as "Editors' Suggestion
TeV Lepton Number Violation: From Neutrinoless Double Beta Decay to the LHC
We analyze the sensitivity of next-generation tonne-scale neutrinoless double
-decay () experiments and searches for same-sign
di-electrons plus jets at the Large Hadron Collider to TeV scale lepton number
violating interactions. Taking into account previously unaccounted for physics
and detector backgrounds at the LHC, renormalization group evolution, and
long-range contributions to nuclear matrix elements, we find
that the reach of tonne-scale generally exceeds that of the
LHC. However, for a range of heavy particle masses near the TeV scale, the high
luminosity LHC and tonne-scale may provide complementary
probes.Comment: 5 pages, 3 figure
Confinement-induced resonance in quasi-one-dimensional systems under transversely anisotropic confinement
We theoretically investigate the confinement-induced resonance for
quasi-one-dimensional quan- tum systems under transversely anisotropic
confinement, using a two-body s-wave scattering model in the zero-energy
collision limit. We predict a single resonance for any transverse anisotropy,
whose position shows a slight downshift with increasing anisotropy. We compare
our prediction with the recent experimental result by Haller et al. [Phys. Rev.
Lett. 104, 153203 (2010)], in which two resonances are observed in the presence
of transverse anisotropy. The discrepancy between theory and experiment remains
to be resolved.Comment: 6 pages, 5 figures, accepted for publication in Phys. Rev.
Learning Compositional Visual Concepts with Mutual Consistency
Compositionality of semantic concepts in image synthesis and analysis is
appealing as it can help in decomposing known and generatively recomposing
unknown data. For instance, we may learn concepts of changing illumination,
geometry or albedo of a scene, and try to recombine them to generate physically
meaningful, but unseen data for training and testing. In practice however we
often do not have samples from the joint concept space available: We may have
data on illumination change in one data set and on geometric change in another
one without complete overlap. We pose the following question: How can we learn
two or more concepts jointly from different data sets with mutual consistency
where we do not have samples from the full joint space? We present a novel
answer in this paper based on cyclic consistency over multiple concepts,
represented individually by generative adversarial networks (GANs). Our method,
ConceptGAN, can be understood as a drop in for data augmentation to improve
resilience for real world applications. Qualitative and quantitative
evaluations demonstrate its efficacy in generating semantically meaningful
images, as well as one shot face verification as an example application.Comment: 10 pages, 8 figures, 4 tables, CVPR 201
HoxA9 binds and represses the Cebpa +8 kb enhancer
C/EBPα plays a key role in specifying myeloid lineage development. HoxA9 is expressed in myeloid progenitors, with its level diminishing during myeloid maturation, and HOXA9 is over-expressed in a majority of acute myeloid leukemia cases, including those expressing NUP98-HOXD13. The objective of this study was to determine whether HoxA9 directly represses Cebpa gene expression. We find 4-fold increased HoxA9 and 5-fold reduced Cebpa in marrow common myeloid and LSK progenitors from Vav-NUP98-HOXD13 transgenic mice. Conversely, HoxA9 decreases 5-fold while Cebpa increases during granulocytic differentiation of 32Dcl3 myeloid cells. Activation of exogenous HoxA9-ER in 32Dcl3 cells reduces Cebpa mRNA even in the presence of cycloheximide, suggesting direct repression. Cebpa transcription in murine myeloid cells is regulated by a hematopoietic-specific +37 kb enhancer and by a more widely active +8 kb enhancer. ChIP-Seq analysis of primary myeloid progenitor cells expressing exogenous HoxA9 or HoxA9-ER demonstrates that HoxA9 localizes to both the +8 kb and +37 kb Cebpa enhancers. Gel shift analysis demonstrates HoxA9 binding to three consensus sites in the +8 kb enhancer, but no affinity for the single near-consensus site present in the +37 kb enhancer. Activity of a Cebpa +8 kb enhancer/promoter-luciferase reporter in 32Dcl3 or MOLM14 myeloid cells is increased ~2-fold by mutation of its three HOXA9-binding sites, suggesting that endogenous HoxA9 represses +8 kb Cebpa enhancer activity. In contrast, mutation of five C/EBPα-binding sites in the +8 kb enhancer reduces activity 3-fold. Finally, expression of a +37 kb enhancer/promoter-hCD4 transgene reporter is reduced ~2-fold in marrow common myeloid progenitors when the Vav-NUP98-HOXD13 transgene is introduced. Overall, these data support the conclusion that HoxA9 represses Cebpa expression, at least in part via inhibition of its +8 kb enhancer, potentially allowing normal myeloid progenitors to maintain immaturity and contributing to the pathogenesis of acute myeloid leukemia associated with increased HOXA9
- …
