Contracting out public transit operation services: an incentive performance-based approach

The literature on public transit services contracting, emphasizes the need of efficient contracting designs to promote parties’ interest alignment. There is, however, limited research addressing specific incentive mechanisms. The paper contributes to that literature by developing a performance-based model with an embedded incentive bonus/malus (B/M) mechanism for contracting out transit services. Monte Carlo simulation documents that model’s performance appears sensitive to stochastic specification of some of the B/M drivers, and responsive to changes in the contractual performance factors out of the sub-concessionaire’s control. Evidence on the operation of a light-rail transit system designed based on a version of the model, document that it may contribute to promote ridership patronage, increase the average ride, and ultimately promote the economic operating efficiency of the system. Some policy implications are drawn, namely in terms of public funds allocative efficiency, and promotion of social welfare in contracting transit services.info:eu-repo/semantics/publishedVersio

Contracting out public transit services: a competitive performance-based approach

This paper develops a bonus / malus incentive model to contracting out public transit services, and provides evidence on performance measures of a lightrail transit system operation, procured with a contract designed based on our modeling approach. Empirical results document that the implementation of a performance-based contract with an embedded incentive bonus / malus mechanism, may contribute to promote ridership patronage, increase the average ride, and ultimately significantly improving the overall economic operating efficiency of the system, measured by a 40 percent increase in the operating costs coverage ratio during the contract term

Carbohydrate-active enzymes from pigmented Bacilli: a genomic approach to assess carbohydrate utilization and degradation

<p>Abstract</p> <p>Background</p> <p>Spore-forming <it>Bacilli </it>are Gram-positive bacteria commonly found in a variety of natural habitats, including soil, water and the gastro-intestinal (GI)-tract of animals. Isolates of various <it>Bacillus </it>species produce pigments, mostly carotenoids, with a putative protective role against UV irradiation and oxygen-reactive forms.</p> <p>Results</p> <p>We report the annotation of carbohydrate active enzymes (CAZymes) of two pigmented <it>Bacilli </it>isolated from the human GI-tract and belonging to the <it>Bacillus indicus </it>and <it>B. firmus </it>species. A high number of glycoside hydrolases (GHs) and carbohydrate binding modules (CBMs) were found in both isolates. A detailed analysis of CAZyme families, was performed and supported by growth data. Carbohydrates able to support growth as the sole carbon source negatively effected carotenoid formation in rich medium, suggesting that a catabolite repression-like mechanism controls carotenoid biosynthesis in both <it>Bacilli</it>. Experimental results on biofilm formation confirmed genomic data on the potentials of <it>B. indicus </it>HU36 to produce a levan-based biofilm, while mucin-binding and -degradation experiments supported genomic data suggesting the ability of both <it>Bacilli </it>to degrade mammalian glycans.</p> <p>Conclusions</p> <p>CAZy analyses of the genomes of the two pigmented <it>Bacilli</it>, compared to other <it>Bacillus </it>species and validated by experimental data on carbohydrate utilization, biofilm formation and mucin degradation, suggests that the two pigmented <it>Bacilli </it>are adapted to the intestinal environment and are suited to grow in and colonize the human gut.</p

Validation of Automated Protein Annotation

Given the large amount of data stored in biological databases, the management of uncertainty and incompleteness in them is a non-trivial problem. To cope with the large amount of sequences being produced, a significant number of genes and proteins have been functionally characterized by automated tools. However, these tools have also produced a significant number of misannotations that are now present in the databases. This paper proposes a new approach for validating the automated annotations, which uses the large amount of publicly available information to compare automated annotations with preexisting curated annotations. To test the proposed approach, we developed a novel unsupervised method for filtering misannotations provided by automated annotation systems. We evaluated our method using the automated annotations submitted to BioCreAtIvE, a joint evaluation of state-of-the-art text-mining systems in Biology. The method scored each of these annotations and those scored below a certain threshold were discarded. The results have shown a small trade-off in recall for a large improvement in precision. For example, we were able to discard 44.6%, 66.8% and 81% of the misannotations, maintaining 96.9%, 84.2%, and 47.8% of the correct annotations, respectively. Moreover, we were able to outperform each individual submission to BioCreAtIvE by proper adjustment of the threshold. These results show the effectiveness of our approach in assisting curators of large biological databases in the use of contemporary tools for automatic identification of annotation

Selecting Critical Properties of Terpenes and Terpenoids through Group-Contribution Methods and Equations of State

The knowledge of critical properties is fundamental in engineering process calculations for the estimation of thermodynamic properties and phase equilibria. A literature survey shows a large number of methods for predicting critical properties of different classes of compounds, but no previous study is available to evaluate their suitability for terpenes and terpenoids. In this work, the critical properties of terpenes and terpenoids were first estimated using the group-contribution methods of Joback, Constantinou and Gani, and Wilson and Jasperson. These were then used to calculate densities and vapor pressure through the equations of state Peng-Robinson (PR) and Soave-Redlich-Kwong (SRK) and then compared with the experimental values. On other hand, density and vapor pressure experimental data were used to estimate the critical properties directly by the same equations of state (EoSs), allowing a comparison between the two estimation procedures. For this purpose densities for 17 pure terpenes and terpenoids were here measured at atmospheric pressure in the temperature range (278.15 to 368.15) K. Using the first approach, the best combination is the Joback's method with the Peng-Robinson EoS, despite the high relative deviations found for vapor pressure calculations and difficulties to predict density at low temperatures. Following the second approach, the set of critical properties and acentric factors estimated are able to adequately correlate the experimental data. Both equatio ns show a similar capability to correlate the data with SRK EoS presenting a global %ARD of 3.16 and 0.62 for vapor pressure and density, respectively; while the PR EoS presented 3.61 and 0.66, for the same properties, both giving critical properties estimates also closer to those calculated by the Joback method, which is the recommended group-contribution method for this type of compounds.This work was developed in the scope of the projects POCI-01- 0145-FEDER-007679-CICECO-Aveiro Institute of Materials (ref. FCT UID/CTM/50011/2013), POCI-01-0145-FEDER- 006984−Associate Laboratory LSRE-LCM both funded by European Regional Development Fund (ERDF) through COMPETE2020, Programa Operacional Competitividade e Internacionalização (POCI), and by national funds through FCT (Fundação para a Ciência e a Tecnologia). This work is also a result of project “AIProcMat@N2020 (Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020)”, with the reference NORTE-01- 0145-FEDER-000006, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through ERDF. M.A.R.M. acknowledges FCT for her Ph.D. grant (SFRH/BD/87084/ 2012) and COST for the STSM Grant from COST action CM1206. P. J. Carvalho also acknowledges FCT for a contract under the Investigador FCT 2015, Contract No. IF/00758/ 2015. A.M.P. acknowledges Infochem-KBC for his Ph.D. grant. The software Multiflash from Infochem-KBC was applied in some of the calculationsinfo:eu-repo/semantics/publishedVersio

Самосборка низкоразмерных систем Al, Ni, Ti и Si в условиях околоравновесной конденсации

Дисертація присвячена вивченню закономірностей структуро- утворення тривимірних мікро- та наносистем Al, Ni, Ti та Si за умов близькорівноважної стаціонарної конденсації. Вивчена залежність механізмів структуроутворення конденсату від основних параметрів технологічного процесу: часу конденсації, тиску робочого газу та потужності розряду. Проаналізовані фізичні процеси, що відбуваються під час роботи накопичувальних систем плазма-конденсат. Для цих систем розроблено математичну модель самоорганізації критично малих стаціонарних пересичень, яка вивчена за допомогою фазової площини. Досліджено вплив на кінетику формування мікро- та наносистем Al, Ni, Ti та Si взаємозв’язаних ефекту Гіббса-Томсона та польової селективності. Розроблені та апробовані за допомогою побудови фазових траєкторій математичні моделі, які описують процес самозбірки низькорозмірних систем. Встановлено, що за близько-рівноважних умов можна реалізувати різні структурно-морфологічні форми конденсатів. При цитуванні документа, використовуйте посилання http://essuir.sumdu.edu.ua/handle/123456789/24862Диссертация посвящена изучению закономерностей структуро- образования микро- и наносистем Al, Ni, Ti и Si в условиях критически малых пересыщений. Изучены процессы формирования конденсатов под влиянием структурной и полевой селективностей, степень проявления которых зависит от таких основных технологических параметров, как время конденсации, давление рабочего газа и мощность разряда. Проанализированы конструкции существующих распылитель- ных систем, разработана и создана накопительная система плазма- конденсат (НСПК) на базе планарного магнетрона и совмещенного с ним полого катода. Проанализированы происходящие в НСПК физические процессы и разработана математическая модель, описы- вающая изменение во времени таких нелинейно взаимозависимых технологических параметров, как пересыщение и температура ростовой поверхности. Методом фазовой плоскости установлена возможность самоорганизации критически малых стационарных пресыщений. С помощью математического моделирования показано, что при повышении давления рабочего газа происходит усреднение энергии распыленных атомов, что является необходимым условием повышения стационарности технологического процесса. Изучен механизм формирования фракталов Ni при осаждении предельно слабых паровых потоков на нагретые до относительно высоких температур (620 К) подложки. Показано, что снижение пересыщения паров Ni до критического значения может предельно локализировать области закрепления атомов и является основой для формирования на ростовой поверхности вискеров. Впервые показано, что диссипативная самоорганизация предельно малых стационарных пересыщений в накопительных системах плазма-конденсат приводит к консервативной самоорганизации низкоразмерных систем в виде тех или иных структурно-морфологических состояний поверхности конденсата. Изучены механизмы самосборки пористых пленок Al, трехмерных систем Ti в виде слабо связанных друг с другом ограненных или округлых кристаллов. Показано, что основой такой самосборки конденсатов является предельная минимизация свободной энергии конденсата. При этом селективная самосборка развитой поверхности металлов при проявлении полевой селективности является следствием выравнивания химических потенциалов в различных точках ростовой поверхности до уровня, при котором локальные скорости наращивания конденсатов не зависят от координат поверхности и не изменяются во времени. Изучены механизмы структурообразования конденсатов Si и разработана математическая модель, описывающая самоорганизацию островков одинаковых размеров и формы. При цитировании документа, используйте ссылку http://essuir.sumdu.edu.ua/handle/123456789/24862The aim of dissertation is the study of regularities of Al, Ni, Ti and Si micro- and nanosystems formation under the conditions of critically small supersaturations. It have been studied the processes of condensates forming at influence of structural and field selectivity, they are depend on main technological parameters of condensation process such as time of condensation, pressure of working gas and power discharge. Physical processes in the accumulative ion-plasma system have been analyzed. For this systems was created mathematical model of selforganization extremely low steady-state supersaturation and studied by method of phase plane. The influence of interdependent effects of Gibbs-Thomson and field selectivities on forming kinetic of micro- and nanosystems of Al, Ni, Ti and Si was investigated. It was created and tested due to plotting of phase trajectories mathematical models, which reply for the self-assembly process of low dimensional systems. It was established that different structuralmorphological forms of condensates could be obtain at near equilibrium conditions. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2486

A thermostable GH45 endoglucanase from yeast: impact of its atypical multimodularity on activity

BACKGROUND: The gene encoding an atypical multi-modular glycoside hydrolase family 45 endoglucanase bearing five different family 1 carbohydrate binding modules (CBM1), designated PpCel45A, was identified in the Pichia pastoris GS115 genome. RESULTS: PpCel45A (full-length open reading frame), and three derived constructs comprising (i) the catalytic module with its proximal CBM1, (ii) the catalytic module only, and (iii) the five CBM1 modules without catalytic module, were successfully expressed to high yields (up to 2 grams per litre of culture) in P. pastoris X33. Although the constructs containing the catalytic module displayed similar activities towards a range of glucans, comparison of their biochemical characteristics revealed striking differences. We observed a high thermostability of PpCel45A (Half life time of 6 h at 80°C), which decreased with the removal of CBMs and glycosylated linkers. However, both binding to crystalline cellulose and hydrolysis of crystalline cellulose and cellohexaose were substantially boosted by the presence of one CBM rather than five. CONCLUSIONS: The present study has revealed the specific features of the first characterized endo β-1,4 glucanase from yeast, whose thermostability is promising for biotechnological applications related to the saccharification of lignocellulosic biomass such as consolidated bioprocessing

Magnetoliposomes based on magnetite nanoparticles

In this work, magnetic nanoparticles of magnetite were prepared by soft chemical methods, using different surfactants as templating media. These nanoparticles were either covered with a lipid bilayer, forming dry magnetoliposomes, or entrapped in liposomes - aqueous magnetoliposomes.FCT, FEDER, COMPETE/QREN/EU for financial support to CFUM (Strategic Project PEst-C/FIS/UI0607/2011) and to the research project PTDC/QUI/81238/2006 (FCOMP-01-0124-FEDER-007467)

Soluble starch and composite starch Bioactive Glass 45S5 particles : synthesis, bioactivity, and interaction with rat bone marrow cells

For many biomedical applications, biodegradable and simultaneously bioactive materials are desired. These materials should at the same time be able to support cell function and co-exist with the organism without triggering a relevant immune response. In this work, the synthesis as well as the bioactivity evaluation of newly developed polymer soluble potato starch and composite (with Bioactive Glass 45S5) micron-size particles are reported. An extremely interesting result is that although with different properties, both polymer and composite particles were able to form a calcium phosphate layer at their surface, which is a clear indication of their bioactivity. The cytotoxicity and the ability to support cell attachment and growth of the developed materials were also studied, and both polymer and composite materials were shown to be non-cytotoxic. Preliminary results show that both types of materials were found to allow rat bone marrow cells to attach and to proliferate on their surface and to express osteogenic markers, such as alkaline phosphatase and osteopontin. The obtained results indicate that the developed carriers might be used as substrates for cell culture in vitro, in order to form constructs that might be used as a part of a tissue engineering strategy