Establishing relative weights for contractor prequalification criteria in a pre-qualification evaluation model

Pre-qualification criteria is a screening methodology to select contractors. Each contractor attribute has its own importance in relation to the others. It is an essential process that the relative importance'weights' of each selection criteria be identified. Several methodologies are used to identify such weights. A Delphic technique together with Analytical Hierarchy Process (AHP) utilizing pair-wise analysis was used to establish such weights through a structured questionnaire. The established weights will then be used to develop a contractor's pre-qualification model using a hybrid technique by combining a Neural Network and a Genetic Algorithm

On certain finiteness questions in the arithmetic of modular forms

We investigate certain finiteness questions that arise naturally when studying approximations modulo prime powers of p-adic Galois representations coming from modular forms. We link these finiteness statements with a question by K. Buzzard concerning p-adic coefficient fields of Hecke eigenforms. Specifically, we conjecture that for fixed N, m, and prime p with p not dividing N, there is only a finite number of reductions modulo p^m of normalized eigenforms on \Gamma_1(N). We consider various variants of our basic finiteness conjecture, prove a weak version of it, and give some numerical evidence.Comment: 25 pages; v2: one of the conjectures from v1 now proved; v3: restructered parts of the article; v4: minor corrections and change

Influencing Cost Factors in Road Projects in Gaza Strip Using ANN

Conceptual cost estimate can serve the owners’ feasibility estimate and assists in the establishment of the owner's funding which aids the engineers in designing to a specific budget. Conceptual estimating exhibits low accuracy level due to the lack of project information and the high level of uncertainty at early stage of project development. The purpose of this paper is to determine the most influencing cost factors in road projects using Delphi technique and Artificial Neural Networks. These factors were employed in a neural network (NN) for building a multi-layer perceptron (MLP) model to estimate the road project cost. Historical data of Gaza strip road projects were used to train and test the MLP model. The model developed showed a reduced error rate of 6.3% which demonstrates the ability to estimate the cost of road projects at early stage with higher accuracy

Properties of Recycled Aggregate in Concrete and Road Pavement Applications

This paper highlights the results of the performed testing program which aimed at investigating the possibility of utilizing the recycled crushed aggregates of the construction and demolition wastes (CDW) in engineering applications in Gaza Strip. The characteristics of the crushed aggregates were determined and compared to international standards. The reuse alternative is investigated in concrete mixes and road construction throughout the testing program. Eight representative samples were selected from different locations in Rafah and Khan Younis. A Technical team supervised the collection process, crushing, transporting, handling and testing program. In general, the test results showed that the recycling of the CDW aggregates and its use in both concrete and road sub-base give acceptable results. Most of the characteristic test results were within the standard limits. The results of the tests that concern road applications were good and verified the adequacy of materials. The results of the tests for concrete applications were also desirable and proved that these materials, CDW, could be used in some concrete applications. The values of the CBR ratio at 100% were 186.6 for demolition samples and 186.1 for crushed concrete samples. Comparably with the CBR of the local base course that is ranged between 100 and 130, the CBR values were high due to the large quantity of cementious materials, and achieved the minimum required value (80) for base course at 100% compaction according to AASHTO (T180-D) and (T 193). A local concrete mix design was used for testing CDW use in concrete . This mix gave a compressive strength of about 250 kg/cm2 of compressive strength at 28 days at water to cement ratio of 0.6 and 290 kg cement content. The results of the testing program of the recycled CDW were above expectations and showed, to some extent, good indications. Two testing labs were used to prepare and test the samples. Most tests at 7 and 28 days, showed high results compared to the control samples of natural materials. The results of the compressive strength of all samples at the same water to cement ratio were close to each other

Estimating the Precursor Frequency of Naive Antigen-specific CD8 T Cells

The constraint of fitting a diverse repertoire of antigen specificities in a limited total population of lymphocytes results in the frequency of naive cells specific for any given antigen (defined as the precursor frequency) being below the limit of detection by direct measurement. We have estimated this precursor frequency by titrating a known quantity of antigen-specific cells into naive recipients. Adoptive transfer of naive antigen-specific T cell receptor transgenic cells into syngeneic nontransgenic recipients, followed by stimulation with specific antigen, results in activation and expansion of both donor and endogenous antigen-specific cells in a dose-dependent manner. The precursor frequency is equal to the number of transferred cells when the transgenic and endogenous responses are of equal magnitude. Using this method we have estimated the precursor frequency of naive CD8 T cells specific for the H-2Db–restricted GP33–41 epitope of LCMV to be 1 in 2 × 105. Thus, in an uninfected mouse containing ∼2-4 × 107 naive CD8 T cells we estimate there to be 100–200 epitope-specific cells. After LCMV infection these 100–200 GP33-specific naive CD8 T cells divide >14 times in 1 wk to reach a total of ∼107 cells. Approximately 5% of these activated GP33-specific effector CD8 T cells survive to generate a memory pool consisting of ∼5 × 105 cells. Thus, an acute LCMV infection results in a >1,000-fold increase in precursor frequency of DbGP33-specific CD8 T cells from 2 × 102 naive cells in uninfected mice to 5 × 105 memory cells in immunized mice

A training model for relatives and friends in cognitive behaviour therapy (CBT) informed care for psychosis

Relatives and close friends provide life-long support as informal carers to those living with psychosis. We introduce a model for training informal carers in cognitive behaviour therapy (CBT) for psychosis, called Psychosis Recovery by Enabling Adult Carers at Home (Psychosis REACH). The model aims to address the carers’ own emotional needs and at the same time build their capabilities of promoting the recovery trajectory of the person they care for. We delivered two- and five-day workshops, underpinned by the Psychosis REACH model, to a cohort of 95 self-identified carers recruited via a charitable organisation in Canada. In a single-group before-and-after design, carers’ anxiety, depression and mental well-being significantly improved within a few days. A handful of carers who returned data for their cared-for-person after the end of training, observed either no change or a positive change in functioning. Our findings generated hypotheses that deserve further research to test whether training large groups of relatives and friends in CBT-informed care for psychosis can improve their anxiety, depression and mental well-being in the context of their caring role, as well as improve the functioning of those they care for

Interplay between pleiotropy and secondary selection determines rise and fall of mutators in stress response

Dramatic rise of mutators has been found to accompany adaptation of bacteria in response to many kinds of stress. Two views on the evolutionary origin of this phenomenon emerged: the pleiotropic hypothesis positing that it is a byproduct of environmental stress or other specific stress response mechanisms and the second order selection which states that mutators hitchhike to fixation with unrelated beneficial alleles. Conventional population genetics models could not fully resolve this controversy because they are based on certain assumptions about fitness landscape. Here we address this problem using a microscopic multiscale model, which couples physically realistic molecular descriptions of proteins and their interactions with population genetics of carrier organisms without assuming any a priori fitness landscape. We found that both pleiotropy and second order selection play a crucial role at different stages of adaptation: the supply of mutators is provided through destabilization of error correction complexes or fluctuations of production levels of prototypic mismatch repair proteins (pleiotropic effects), while rise and fixation of mutators occur when there is a sufficient supply of beneficial mutations in replication-controlling genes. This general mechanism assures a robust and reliable adaptation of organisms to unforeseen challenges. This study highlights physical principles underlying physical biological mechanisms of stress response and adaptation

Parasite Evolution and Life History Theory

Beth F. Kochin is with Emory University, James J. Bull is with UT Austin, Rustom Antia is with Emory University.As a group, parasites are extraordinarily diverse. Even closely related parasites may behave very differently, infecting different host species, causing different pathologies, or infecting different tissues. For example, Escherichia coli bacteria, a typically harmless inhabitant of the human gut, can, in different forms, cause diarrhea, intestinal bleeding, urinary tract infections, kidney bleeding, meningitis, and other diseases. Underlying this diversity is evolution.This work is supported by the National Institutes of Health and the Fannie and John Hertz Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Cellular and Molecular Biolog

Reconciling Estimates of Cell Proliferation from Stable Isotope Labeling Experiments.

Stable isotope labeling is the state of the art technique for in vivo quantification of lymphocyte kinetics in humans. It has been central to a number of seminal studies, particularly in the context of HIV-1 and leukemia. However, there is a significant discrepancy between lymphocyte proliferation rates estimated in different studies. Notably, deuterated (2)H2-glucose (D2-glucose) labeling studies consistently yield higher estimates of proliferation than deuterated water (D2O) labeling studies. This hampers our understanding of immune function and undermines our confidence in this important technique. Whether these differences are caused by fundamental biochemical differences between the two compounds and/or by methodological differences in the studies is unknown. D2-glucose and D2O labeling experiments have never been performed by the same group under the same experimental conditions; consequently a direct comparison of these two techniques has not been possible. We sought to address this problem. We performed both in vitro and murine in vivo labeling experiments using identical protocols with both D2-glucose and D2O. This showed that intrinsic differences between the two compounds do not cause differences in the proliferation rate estimates, but that estimates made using D2-glucose in vivo were susceptible to difficulties in normalization due to highly variable blood glucose enrichment. Analysis of three published human studies made using D2-glucose and D2O confirmed this problem, particularly in the case of short term D2-glucose labeling. Correcting for these inaccuracies in normalization decreased proliferation rate estimates made using D2-glucose and slightly increased estimates made using D2O; thus bringing the estimates from the two methods significantly closer and highlighting the importance of reliable normalization when using this technique