2,369 research outputs found
On the Complexity of the Single Individual SNP Haplotyping Problem
We present several new results pertaining to haplotyping. These results
concern the combinatorial problem of reconstructing haplotypes from incomplete
and/or imperfectly sequenced haplotype fragments. We consider the complexity of
the problems Minimum Error Correction (MEC) and Longest Haplotype
Reconstruction (LHR) for different restrictions on the input data.
Specifically, we look at the gapless case, where every row of the input
corresponds to a gapless haplotype-fragment, and the 1-gap case, where at most
one gap per fragment is allowed. We prove that MEC is APX-hard in the 1-gap
case and still NP-hard in the gapless case. In addition, we question earlier
claims that MEC is NP-hard even when the input matrix is restricted to being
completely binary. Concerning LHR, we show that this problem is NP-hard and
APX-hard in the 1-gap case (and thus also in the general case), but is
polynomial time solvable in the gapless case.Comment: 26 pages. Related to the WABI2005 paper, "On the Complexity of
Several Haplotyping Problems", but with more/different results. This papers
has just been submitted to the IEEE/ACM Transactions on Computational Biology
and Bioinformatics and we are awaiting a decision on acceptance. It differs
from the mid-August version of this paper because here we prove that 1-gap
LHR is APX-hard. (In the earlier version of the paper we could prove only
that it was NP-hard.
APOM-project : a study of pharmacy practice
In 1994, a Ph.D-study started regarding pharmacy, organization and management (APOM) in the Netherlands. The APOM-project deals with the structuring and steering of pharmacy organization. This article describes the summary of the empirical results of a survey in a relatively large sample (n=169). Generalization to the population of pharmacies in the Netherlands was made. The results for thought, the perceived importance of activities, comprised a total number of seven clusters of priorities of pharmacy mixes. Most pharmacy managers perceived the product (pharmaceutical) activities and the customer activities as the most important. The results for action, the actual performance of activities, comprised a total number of five clusters of activities of pharmacy mixes. Most pharmacy managers performed the product activities and the process (financial-economic) activities most frequently. The results showed that the traditional conception of the work in the community pharmacy is still vividly present.
APOM-project: a pilot study of pharmacy organization and management
Recently, in a joint cooperation of Stichting VNA, SAL Apotheken, the Faculty of Management and Organization, and the University Centre for Pharmacy, University of Groningen in the Netherlands, a Ph.D-study started regarding Apot(he)ek, Organization and Management (APOM). The APOM-project deals with the structuring and steering of pharmacy organization. The manageability of the internal pharmacy organization, and the manageability of the direct environment of pharmacy organization is the subject matter. The theoretical background of the APOM-project is described. A literature study was made to find mixes of objectives. Three mixes of objectives in pharmacy organization are postulated; the product mix, the process mix, and the customer mix. The typology will be used as a basic starting point for the empirical study in the next phase of the APOM-project.
APOM-project: an investigation of pharmacy organization and management
Recently, in a joint cooperation of Stichting VNA, SAL Apotheken, the Faculty of Management and Organization, and the University Centre for Pharmacy, University of Groningen in the Netherlands, a Ph.D-study started regarding Apot(he)ek, Organization and Management (APOM). The APOM-project deals with the structuring and steering of pharmacy organization. The manageability of the internal pharmacy organization, and the manageability of the direct environment of pharmacy organization is the subject matter. The theoretical background of the APOM-project is described. A literature study was made to find mixes of objectives. Three mixes of objectives in pharmacy organization are postulated; the product mix, the process mix, and the customer mix. The typology will be used as a basic starting point for the empirical study in the next phase of the APOM-project.
The Effect of Fermentation Time (as Induced by Fermentation and Must Conditions) on the Chemical Profile and Quality of a Chenin blanc Wine
Pattern recognition and simple factorial analyses were applied to chemical profiles determined on wines resulting from an experiment in which the effect of grape solids, assimilable nitrogen, bentonite and fermentation temperaturelevels as well as culture aeration on total fermentation time was investigated. It was found that fermentation times of the untreated Chenin blanc must could be shortened considerably by increasing grape solid levels and/ or nitrogen as well as temperature. However, it was established that the speeding up of fermentation at sub-optimal assimilable nitrogen levels leads to wines relatively high in higher alcohols and low in esters
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