21,748 research outputs found
Comparative growth and survival of fry of Clarias gariepinus (B), Clarias anguillaris (L), Heterobranchus bidorsalis (G), Heteroclarias, Clariabranchus and Clarias hybrids under outdoor nursery management system
Hybrids of Clariid catfishes; C. gariepinus (Netherlands), C. anguillaris, H. bidorsalis and their parental species were monitored for 8 weeks in 2 x 2 x 1m outdoor concrete tanks. The fry were fed NIFFR diet (40% crude protein) twice daily, 7 days of the week. Growth and survival records were taken weekly. The male HEB X female CLG hybrid showed an overall highest performance in growth rate while the lowest was recorded in male CLA X female CLG hybrid. The male HEB X female CLG hybrid grew at a faster rate than its reciprocal hybrid. In view or their growth rate, it is possible that the growth and survival rates or H. bidorsalis especially at the fry to fingerling stage could be improved through hybridization. The hybrid have potential as commercial food fis
The Role Of Local Authorities In Health Issues: A Policy Document Analysis
Prior to the passing of the Health and Social Care Act 2012 the Communities and Local Government (CLG) Select Committee conducted an investigation into the proposed changes to the Public Health System in England. The Committee considered 40 written submissions and heard oral evidence from 26 expert witnesses. Their report, which included complete transcripts of both oral and written submissions, provided a rich and informed data on which to base an analysis of the proposed new public health system. This report analyses the main themes that emerged from the evidence submissions and forms part of our preliminary work for PRUComm’s PHOENIX project examining the development of the new public health system
Affordable housing definitions and Section 106 contributions in England
This paper examines whether Local Planning Authority definitions of affordable housing provide adequate clarity with which to negotiate affordable housing contributions with private sector house builders. The paper updates Government research, Delivering Affordable Housing through Planning Policy (ODPM, 2002), by systematically interrogating the affordable housing definitions of 51 Local Planning Authorities in England. LPA housing and planning documents were scrutinised in respect of the local definition of affordable housing, whether it conformed to the Governments ‘new’ PPS3 definition, the thresholds set at which the requirement for affordable housing is triggered and the target level at which Section 106 contributions are set. The findings indicate that although Local Planning Authority definitions of affordable housing have improved in terms of their quality, precision and clarity, one in five LPAs still did not provide a concise definition of affordable housing
If the Current Clique Algorithms are Optimal, so is Valiant's Parser
The CFG recognition problem is: given a context-free grammar
and a string of length , decide if can be obtained from
. This is the most basic parsing question and is a core computer
science problem. Valiant's parser from 1975 solves the problem in
time, where is the matrix multiplication
exponent. Dozens of parsing algorithms have been proposed over the years, yet
Valiant's upper bound remains unbeaten. The best combinatorial algorithms have
mildly subcubic complexity.
Lee (JACM'01) provided evidence that fast matrix multiplication is needed for
CFG parsing, and that very efficient and practical algorithms might be hard or
even impossible to obtain. Lee showed that any algorithm for a more general
parsing problem with running time can
be converted into a surprising subcubic algorithm for Boolean Matrix
Multiplication. Unfortunately, Lee's hardness result required that the grammar
size be . Nothing was known for the more relevant
case of constant size grammars.
In this work, we prove that any improvement on Valiant's algorithm, even for
constant size grammars, either in terms of runtime or by avoiding the
inefficiencies of fast matrix multiplication, would imply a breakthrough
algorithm for the -Clique problem: given a graph on nodes, decide if
there are that form a clique.
Besides classifying the complexity of a fundamental problem, our reduction
has led us to similar lower bounds for more modern and well-studied cubic time
problems for which faster algorithms are highly desirable in practice: RNA
Folding, a central problem in computational biology, and Dyck Language Edit
Distance, answering an open question of Saha (FOCS'14)
Scaling behavior of the conserved transfer threshold process
We analyze numerically the critical behavior of an absorbing phase transition
in the conserved transfer threshold process. We determined the steady state
scaling behavior of the order parameter as a function of both, the control
parameter and an external field, conjugated to the order parameter. The
external field is realized as a spontaneous creation of active particles which
drives the system away from criticality. The obtained results yields that the
conserved transfers threshold process belongs to the universality class of
absorbing phase transitions in a conserved field.Comment: 6 pages, 8 figures, accepted for publication in Phys. Rev.
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