209 research outputs found
Effects of \u3ci\u3eParthenium hysterophorus\u3c/i\u3e on Grassland Community in Nyando Sub-County, Kisumu County, Kenya
Parthenium hysterophorus is an invasive alien species native to South and Central America. The plant is ranked as one of the most dreaded weeds of the world. Parthenium hysterophorus affects grassland community through the release of allelochemicals that inhibit the germination and growth of grass species. However, little is known about its effects on native grassland community in Nyando sub-county of Kenya. Therefore, this study sought to investigate the effects of P. hysterophorus on grass species, livestock production and its control. A total of 121 farm household heads were interviewed using semi-structured interview schedules. Descriptive analysis and the T-test at 5% level of significance were used to analyse data. Sixty-three percent of respondents reported that P. hysterophorus replaced major native pasture species consequently reducing the quantity of milk yield per cow significantly by 3.81 litres. Majority households (98.3%) controlled P. hysterophorus by uprooting, slashing and hoeing while the remaining households used herbicides. The cost of controlling P. hysterophorus is expensive at about Kes. 6,253.33 per acre. Parthenium hysterophorus has the potential to negatively affect grasslands in Kenya with adverse impact on human livelihoods by reducing milk and beef production, lack of high quality nutrition food as well as the attainment of development targets such as those set in the Big Four Agenda, the Vision 2030 and the Sustainable Development Goals
Experimental achievement of the entanglement assisted capacity for the depolarizing channel
We experimentally demonstrate the achievement of the entanglement assisted
capacity for classical information transmission over a depolarizing channel.
The implementation is based on the generation and local manipulation of 2-qubit
Bell states, which are finally measured at the receiver by a complete Bell
state analysis. The depolarizing channel is realized by introducing quantum
noise in a controlled way on one of the two qubits. This work demonstrates the
achievement of the maximum allowed amount of information that can be shared in
the presence of noise and the highest reported value in the noiseless case.Comment: 4 pages, 3 figure
Acknowledgements
The allocation of time is a crucial decision that influences many aspects of household welfare. According to standard theory it depends on the potential wage rate of spouses relative to their domestic productivity. A major problem, however, is that individual productivities are not observed. As a consequence, an important source of difference in household living standards alongside with heterogeneity in preferences and wage rates, cannot be accounted for. This paper presents a new methodology to estimate individual domestic productivity based on the informational content of a standard time use survey, with time inputs observable but domestic output immeasurable. It provides empirical evidence based on a sample of French two-earner couples. As a test of the empirical validity of this approach, the paper shows that the estimate of female domestic productivity is a significant variable in explaining the overall intra-household distribution of resources
Experimental Quantum Networking Protocols via Four-Qubit Hyperentangled Dicke States
We report the experimental demonstration of two quantum networking protocols,
namely quantum 1->3 telecloning and open-destination teleportation, implemented
using a four-qubit register whose state is encoded in a high-quality two-photon
hyperentangled Dicke state. The state resource is characterized using criteria
based on multipartite entanglement witnesses. We explore the characteristic
entanglement-sharing structure of a Dicke state by implementing high-fidelity
projections of the four-qubit resource onto lower-dimensional states. Our work
demonstrates for the first time the usefulness of Dicke states for quantum
information processing.Comment: 4 pages + Supplementary Information, 6 figures; revised version:
Accepted for publication in Phys. Rev. Let
Fully nonlocal quantum correlations
Quantum mechanics is a nonlocal theory, but not as nonlocal as the
no-signalling principle allows. However, there exist quantum correlations that
exhibit maximal nonlocality: they are as nonlocal as any non-signalling
correlations and thus have a local content, quantified by the fraction of
events admitting a local description, equal to zero. Exploiting the link
between the Kochen-Specker and Bell's theorems, we derive, from every
Kochen-Specker proof, Bell inequalities maximally violated by quantum
correlations. We then show that these Bell inequalities lead to experimental
bounds on the local content of quantum correlations which are significantly
better than those based on other constructions. We perform the experimental
demonstration of a Bell test originating from the Peres-Mermin Kochen-Specker
proof, providing an upper bound on the local content .Comment: 9 pages, 5 figures and three tables. To appear in PR
Development of a Toolkit for Participatory Management of Rural Watersheds in Kenya
Effective public participation is a foundation for sustainable watershed management, yet there are no demonstrated methods for or examples of its achievement in tropical semi-arid rural grassland watersheds of Kenya which support critical downstream water services. Within the Sustainable Management of Watersheds (SUMAWA) multidisciplinary international research project, a set of tools has been developed and tested to engage local communities and stakeholders in a dialogue and decision-making process to improve the development and management of the River Njoro Watershed in Kenya and reverse declining water quality and quantity problems. A toolkit manual based on the experience is under preparation for general distribution
Engineering a C-Phase quantum gate: optical design and experimental realization
A two qubit quantum gate, namely the C-Phase, has been realized by exploiting
the longitudinal momentum (i.e. the optical path) degree of freedom of a single
photon. The experimental setup used to engineer this quantum gate represents an
advanced version of the high stability closed-loop interferometric setup
adopted to generate and characterize 2-photon 4-qubit Phased Dicke states. Some
experimental results, dealing with the characterization of multipartite
entanglement of the Phased Dicke states are also discussed in detail.Comment: accepted for publication on EPJ
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