bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of some variables on the removal of synthetic bentonite suspension in water by electrocoagulation using turbidity measurements
Authors: Al-Rubaiey N A , Albrazanjy M G
Published: August 2019

Electrocoagulation can be considered as a simple and an efficient method for treating both wastewater and water. In this work, a synthetic bentonite suspension water was treated using this technique to reduce turbidity caused by solid particles pollutants. This process was carried out in a batch glass reactor of 1000 ml operated with aluminium electrodes with and without agitation. The removal efficiency as a turbidity removal procedure has been examined using bentonite clay as a turbidity source. The effects of some parameters such as contact time, and electrolyte concentration on the removal efficiency were investigated and compared. The mixing effect over the range (0-800 rpm) on the removal efficiency was also evaluated. The process was found to achieve excellent turbidity removal with mild mixing (550 rpm). In addition, the effect of using Ultrasonic as a mixing source has also been studied. The lowest residual turbidity was found to be 1.0 NTU for the samples with initial turbidities of 500 NTU. Similar final turbidity of 1.0 NTU was obtained after 25 min with initial turbidity of 200 NTU. This was obtained at a current of 750 mA, a contact time of 60 min, and a calculated dissolved aluminium concentration of 10 mg/l.
The use of Mixed Bacterial Culture to improve the Biodegradation of Diesel Pollution
Authors: Jabbar N M , Mohammed A K , Jabber S M , Kadhim E H
Published: August 2019

This study was conducted to evaluate the hydrocarbon biodegradation abilities of Enterobacter cloacae, Staphylococcus aureus, Sphingomonas paucimobilis, and Pentoae species which were isolated from different diesel-contaminated soil samples. The isolates were identified by the Vitek 2 system. Fourier-transform spectroscopy (FT-IR) tested the potential of these isolates to biodegrade the diesel according to the peak areas, a significant decrease in the area of the peaks at 2856-2928 cm−1 corresponds to aliphatic hydrocarbons. The appearance of small peaks at 900-1032 cm−1 refers to substituted benzene derivative compounds. An appearance of some new peaks at 3010- 3030 cm−1 which indicate the presence of alcohol (-OH) and ketones (RC=O). A sharp peak appeared at 1712 cm−1 refers to the carbonyl group (C=O). The potential of biological surfactant production was tested using the Sigma 703D stand-alone tensiometer showed that these isolates were biological surfactant producers. The better results of the surface tension reduction test were obtained when using the mixed bacterial culture which reduced the surface tension of the medium from 66 mN/m to 35.15 mN/m. Single isolates and mixed bacterial culture have investigated their ability to degrade 3.0 % (v/v) of diesel as sole source of carbon and energy in Bushnell- Haas medium. The results demonstrated that the bacterial isolates could be effective in biodegradation of diesel spills individually and showed good biodegradation abilities when they are used together in the mixed bacterial culture.
Environmental pollution control emitted from diesel engines by Al2O3 nanoparticles
Authors: Sharif Hamadi Adel , Ghufran Khidhir Ali
Published: August 2019

One of the most important problems for diesel engines is the emissions of nitrogen oxides (NOx) and smoke, the use of emulsification technology is one of the most influential ways to control this emissions. In this present work Aluminum oxide (Al2O3) are blended by rotary-stator homogenizer at three different levels (50,100,150 ppm) with prepared Nano-emulsion at optimum composition and circumstances that are analyzed experimentally by Design Expert software. Alumina nanoparticle with its high thermal conductivity (30−1 Wm K−1 compare to diesel and high calorific value which helps to promote more internal combustion due to making higher thermal efficiency. Direct injection (DI), water cooled four cylinders, in-line, natural aspirated Fiat diesel engine was used and run at a constant speed (1500 rpm) and constant fuel injection pressure (400 bars) with varying the operation load. Multigas analyzer model 4880 was used to measure the concentration of the emission gases such as NOx, unburned total hydrocarbon HC, CO2 and CO. The engine exhaust smoke emissions were measured using the AVL-415 smoke meter. Based on these observations, the rate of CO and NOx would be reduced significantly up to 24 and 5.8 %, at 150ppm to net diesel respectively, noting that the net smoke of diesel would undergo the highest change (up to 26.5 %). The results also indicate a 6.97 % fuel consumption reduction accompanied with 6.2 % improvement in the thermal efficiency, utilizing Al2O3 nanoparticles in blended in Nano-emulsion. Enhancement in break thermal efficiency (BTE), reduction in (NOx) and smoke are noticed after mixing Al2O3 into prepared nano-emulsion.
Modify Chock Performance Equation for Tertiary Reservoir Wells in Khabaz Oil Field
Authors: Jumaah Haider A.
Published: August 2019

Gilbert correlation has been modified to determine the performance of multiphase fluid-flow through the wellhead and choke. The modification present two sets of new correlations based on statistical analysis of 33 production tests data from 12 wells produce from Tertiary Reservoir in Khabaz oil field, first correlation is modified of Gilbert equation to predict liquid flow rates as a function of wellhead flowing pressure, gas-liquid ratio and choke size, the second correlation takes the effect of water cut and sediment (BS & W) as an effective parameter to minimize error. A comparison between the results of each correlation with measured date has been made to select the best correlation to predict flow rate in newly drilled wells. The oil flow rates predicted by the new correlations show excellent agreement with the measured rates and the second modified Gilbert correlation are found to be closest to all ranges of flow rate variables with an average error of 10 % and R2=0.9493.
Dynamic model of Tertiary reservoir in Khabaz Oil field
Authors: Mousa Mohamad B. , Qader Nabaz
Published: August 2019

This study deals with building a reservoir model for Tertiary reservoir in Khabaz oil field and calculate oil and gas in place by volumetric method using Petrel RE software and by Dynamic method through material balance by using MBAL software, testing the reservoir dynamic model through history match over 26 years, and predicted (4) case of reservoir and well performance over 29 years start at the end of history match (1/1/2016 ) until (1/1/2045) by natural depletion for case-1 Do nothing (current producing wells), Case-2 Base case (work over non-producing wells) case-4 new wells ( drill 6 new wells) and add water injection for case-3 (drill 7new water injector wells).
A New Algorithm for Foot-By-Foot Permeability and Irreducible water Saturation Estimation in Iraqi Limestone Reservoirs
Authors: Haider Qays M , Ruya Ahmed G
Published: August 2019

This paper discusses the methodology developed for petrophysical modeling and its application to the main limestone formations in the Mid-region of Iraq. The systematic approach presented in this study evaluates not only combination of porosity, permeability and irreducible water saturation at each depth, but also free-water level and capillary pressure curve, such that water-cut of flow tests is closely reproduced in numerical simulation. It is one of the major achievements in this study. The algorithm matched to several sets of core samples: 2,903 porosity, 2,767 permeability, and 95 Irreducible water saturation samples that give the algorithm the robustness for future properties prediction. To develop the prediction Algorithm, it was employed multiple regression analysis (MRA) which mathematically requires independence between explanatory variables. Since possible explanatory variables (porosity, permeability and facies) indicate interdependency, it was investigated when necessary to transform the variables into independent axes. It was found that logarithm of permeability has correlations positive to porosity and FZI and negative to irreducible water saturation. Therefore, foot-by-foot evaluation shall meet the following conditions, (Sw) along wells shall be explained by single free-water level (FWL) for each pressure compartment and Water-cut observed on production test shall also be closely simulated with the FWL, For modeling purposes, Sw is split into irreducible water saturation (Swir) and transitional (mobile) water saturation (Swm) as water-cut is a function of only the latter.
Evaluation of Formation Capacity and Skin Phenomena of Mishrif Reservoir -Garraf Oil Field
Authors: Baker H A , Al-Rikaby A , Salih I S
Published: August 2019

Mishrif Formation is the main reservoir in Garraf Oil Field. It is divided into three productive units (M1, L1.1, and L1.2), the unit L2 contains a very small percentage of oil with high majority of water so it is considered to be of a non-economic feasibility. Developing of such reservoir requires a study of its capacity and how the effective communication properties changes laterally. Build up pressure testing was conducted for five wells (A16P, Ga-1, A4P, B5P and C43P) in Garraf oil field. The data have been analysed by Ecrin Kappa Saphir program and well behaviour was detected by pressure and pressure derivative responses (or signature) with time. The results show a difference in capacity with good flowing capabilities. All the wells exhibit a negative skin factor due to stimulation
The effect of coarse aggregate inclusion on the performance of reactive powder concrete exposed to oil products
Authors: al-Attar T S , Ali A S , Al-Numan B S
Published: August 2019

Reactive powder concrete, RPC, is an ultra-high strength and high ductility cementitious composite with advanced mechanical and physical properties. RPC is composed of very fine powders (cement, sand, quartz powder and silica fume), steel fibers (optional) and superplasticizer. A basic principle, which was presented by the first developers of RPC, is to eliminate the coarse aggregate in mixture to enhance homogeneity. The main purpose of the present investigation is to modify RPC by including natural graded coarse aggregate in the mixture in different approaches. The investigation was devoted to monitor the strength development, total absorption and permeability of RPC after exposure to two types of oil products, kerosene and gas oil, up to 180 days. The current results showed that eliminating coarse aggregate as a principle could be gone-beyond. The better way for including coarse aggregate in RPC was to replace the fine sand and the most useful FA/A ratio is expected to be within the range of 0 - 25 % by weight. This range was found to create an optimum situation between strength and absorption for kerosene and gas oil exposures. It is not recommended to include the coarse aggregate in RPC mixtures as a replacement to the binder specially when dealing with oil products storage.
Optimization of the output device of a disk pump for high viscous fluid
Authors: Cheremushkin V , Polyakov A
Published: August 2019

In this paper the problem of designing an output device for dynamic pumps operating at a high fluid viscosity on the example of a disk pump was considered. The main objective of the study was to increase the pump efficiency by optimizing the geometry of the wet part of its volute. The dependences of the efficiency on the geometrical parameters of the output device estimated section were obtained. The results of the study are represented in a form of graphs and scalar field distributions.
Finding the minimum number of optimization points for an axial aircraft pump
Authors: Protopopov A , Mukhlaeva A , Vdovin D
Published: August 2019

Annotation

This article discusses issues related to the calculation of aircraft axial pumps. These pumps are subject to ever-increasing demands due to high competition in the aviation industry. The highest requirements for parameters are the dimensions of the impeller and power consumption. This article discusses the method of constructing the diameter of the impeller - the expended power of an axial pump.
Optimization of a radial guide device with a no-vane transfer channel
Authors: Isaev N , Valiev T , Morozova E , Bondareva D
Published: August 2019

Various studies show that the centrifugal multistage pump guide vanegreatly determines the hydraulic efficiency of the pump and, as a result, the optimal mode of its operation. In order to increase the pump efficiency, the radial guide vane with a no-blade transfer channelwas optimized. Three geometrical parameters and the number of channels of the guide vanewere chosen as optimization parameters; the hydraulic efficiency was the optimization criterion. 128 computational models were made, and the efficiency values at the operating point were obtained by the method of hydrodynamic modeling. As a result, significant increase in the pump efficiency was achieved.
On the centrifugal pump optimization question
Authors: Tkachyk V , Atamas V , Shablovskiy A
Published: August 2019

There is a wide range of rotor rotational frequencies and cavitation cavitatin margins used in the industrial centrifugal pumps. The effect of these parameters on the dimensions criteria and cavitation characteristics of a pump is studied in this paper, the Sobol method is proposed for it and the task is to find the minimum number of point sat which the best ratio of the parameters will be achieved.
Optimization of centrifugal pump radial guide vanes
Authors: Morozova E , Bondareva D , Shablovsky A
Published: August 2019

Centrifugal multi-stage pump hydraulic efficiency and, as a result, its optimal mode of operation depend primarily on guide vanes. Radial crossover guide vanes were optimized in order to increase pump hydraulic efficiency. Three geometric parameters and the number of guide vane channels were chosen as optimization parameters, and pump hydraulic efficiency was chosen as the criterion. Automatic parameterized design method produced 128 design models; hydraulic efficiency in work mode was calculated with the help of hydrodynamic simulation. Optimization brought about significant increase of pump hydraulic efficiency.
Comparison of various simulation methods of a two-phase flow in a multiphase pump
Authors: Boyarshinova A , Lomakin V , Petrov A
Published: August 2019

Annotation

The article presents a mathematical model of a two-phase flow in a multiphase helico-axial pump. In this paper, the model of a multiphase incompressible fluid flow (ρ = const) were used. Numerical simulation is based on solving discrete anagoges of the basic hydrodynamic equations. The hydrodynamic simulation of the described mathematical model was performed in two ways: in a simplified form, using a multiphase volumeoffluid model (VOF), and the segregated flow method. The results of the calculation of two-phase flows for various values of the gas contaent are given. The influence of gas content on the pump performance and its pressure is considered. A comparison of calculation results of two methods of hydrodynamic simulation of two-phase flow is shown.
Mathematical modeling and analysis of the electrohydraulic actuator with the throttle control
Authors: Sosnovsky N , Ganieva D
Published: August 2019

Annotation

High demands to modern electrohydraulic actuators are placed. This applies to the static and dynamic characteristics of the drives, which is achieved by using different correcting devices (controllers). In the article analysis of the most effective regulator for an electro-hydraulic actuator is conducted during the comparison of its dynamic characteristics at introduction of various types of correcting devices: the introduction of state controller, the introduction of additional pressure feedback and a proportional controller. Block diagrams of the electrohydraulic actuator are constructed according to the corresponding mathematical models. The optimization of the control parameters was carried out to improve the static characteristics of the actuator.
Quad bike frame dynamic load evaluation using full vehicle simulation model
Authors: Vdovin D , Chichekin I , Ryakhovsky O
Published: August 2019

The paper describes a quad bike multi-body model intended to extract maximum dynamic forces acting on the vehicle frame. This complex full-vehicle model includes all essential systems such assuspension, steering, frame, power train, brakes, payload, as well as tire-road interaction model. A number of the quad bike operation events has been simulated. Time histories of the forces acting on the vehicle frame and tire contact patch have been analyzed and load cases with maximum forces have been extracted for subsequent finite-element analysis of the frame. In case the sufficient number of the events is simulated, the load cases can be used in the design optimization process, such as topology optimization, at early stages of the frame development.
Light frame design for quad bike using topology optimization
Authors: Vdovin D , Levenkov Y , Chichekin V
Published: August 2019

The paper describes a quad bike frame design procedure with the use of topology optimization technique. The design space specific properties, quad bike specific load cases and problem formulation for topology optimization are presented. Topology optimization results – beneficial load paths of the frame structure – have been interpreted into a new frame design providing sufficient space for placement of all systems of the vehicle. The new frame strength has been proved using finite element method. Comparing with the previous steel frame design, the new frame of the quad bike has become 2 times as stiff and 17% lighter while having low stress levels due to the substitution of aluminum material for steel and a new optimized topology of the frame load-bearing structure.
Mathematical model of interaction of a rolling elastic wheel with elastic-visco-plastic support base taking into account the history of loading
Authors: Zhileykin M , Zakharov A , Panshin M
Published: August 2019

One of the main methods to predict permeability is a simulation of the motion of wheeled vehicles in different operating conditions, which are based on mathematical models of interaction between elastic tires with deformable irregularities of the support base. Currently in the theoretical study of the interaction of propellers with the ground formed two main directions: analytical method involving a mathematical description of the process under study and the finite element method based on computer simulation. The aim of this study is to develop a mathematical model of rolling elastic wheels on deformable rough reference base, taking into account the deformation of the contact patch at each end of the elementary playground. A mathematical model of the curvilinear rolling of the elastic wheel on an uneven elastic-visco-plastic support base is developed, taking into account the deformation of the contact spot in each finite elementary site; the influence of ground hooks on the parameters of the wheel movement; coupling properties of the support base in the horizontal direction under the action of a vertical load; change in the direction of radial and tangential reactions; elastic- visco-plastic properties of the support base;“history” of loading of each elementary platform of the support base; condition of the support base on its physical and mechanical characteristics.
Comparison of various simulation methods of a two-phase flow in a multiphase pump
Authors: Boyarshinova A , Lomakin V , Petrov A
Published: August 2019

Annotation

The article presents a mathematical model of a two-phase flow in a multiphase helico-axial pump. In this paper, the model of a multiphase incompressible fluid flow (ρ = const) were used. Numerical simulation is based on solving discrete analogues of the basic hydrodynamic equations. The hydrodynamic simulation of the described mathematical model was performed in two ways: in a simplified form, using a multiphase volume of fluid model (VOF), and the segregated flow method. The results of the calculation of two-phase flows for various values of the gas content are given. The influence of gas content on the pump performance and its pressure is considered. A comparison of calculation results of two methods of hydrodynamic simulation of two-phase flow is shown.
Study of the corrosion rate of the paths walls of aluminum heat exchangers in the ethylene glycol antifreezes environment under developed aeration of power fluid
Authors: Petrov A , Saatashvili G , Averianov A , Bilenko I
Published: August 2019

Annotation

An experimental and theoretical research work on the corrosion processes of heat exchanger channels made from different aluminum alloys in an ethylene glycol antifreeze environment conducted by the authors is described in the article. The hydrodynamic simulation of the flow in the paths was performed. Significant effects of the aeration of the power fluid, the possibility of electrochemical corrosion are proved. The comparative of anti-corrosion property of different aluminum alloys is shown when operating in a wide range of power fluid velocities and temperatures.
Investigation of the performance of the oil gas separator depending on the gas content of the pumped liquid. Development of methods for optimizing the geometry of flow-through parts of centrifugal gas separators
Authors: Ershov M , Lomakin V
Published: August 2019

Annotation

This article formulates the problems of using oil separators in the current conditions of well operation, as well as research and pilot implementation of innovative oil production technologies. A variant of the improved flow part of the separator was proposed, a mathematical model was written for its further calculation, and the hydrodynamic calculation itself was carried out, the results of which will later be used to study methods for optimizing the geometry of flow parts of centrifugal gas separators.
Travelling salesman problem concerning to manipulator Kawasaki FS03N trajectory formation
Authors: Kulakov B , Kulakov D
Published: August 2019

An idea of travelling salesman problem (TSP) application to an optimal manipulator path finding was implemented. A set of known poses robot should pass is given. The poses sequence may vary. A traveling time is a performance criteria to be minimized. This task was realized concerning to a special case of Kawasaki FS03N manipulator movement by dynamic programming method. A special Bellman function state notation was used that in some cases gives an ability to solve the task at industrial robot controller. The state notation rule is one-one mapping rule between TSP state and array index it is stored.
Descriptive study of homeless patients’ perceptions that affect medication adherence
Authors: Richler Matthew J , Yousaf Sara , Hwang Stephen W , Dewhurst Norman F
Published: August 2019

Purpose

Results of a study to elucidate perceptions, attitudes, and beliefs about prescribed medications held by hospitalized patients who are homeless are reported.

Methods

A qualitative descriptive study involving semistructured interviews was conducted to gather information and characterize hospitalized homeless patients’ views and attitudes regarding medication use, with a focus on medication nonadherence. Medication nonadherence has been shown to be a factor contributing to higher rates of emergency department visits, increased hospital lengths of stay, and increased healthcare costs in homeless populations. Interviews were conducted during patients’ admissions to the internal medicine service of a tertiary care, inner-city hospital. Interviews were audio-recorded and transcribed. Data were analyzed using conventional qualitative content analysis to generate data-driven codes and themes.

Results

Twelve interviews were conducted (median patient age, 48.5 years). Eight patients (66.7%) were living in a shelter, and 11 (91.7%) had a mental illness. Patients were prescribed a median of 4 medications at the time of hospital admission. Four themes were identified: (1) a new appreciation of medications was acquired during hospitalization, (2) medications were perceived as necessary for maintaining health, (3) there was an interest in receiving medication education, and (4) concerns were expressed regarding medication adverse effects.

Conclusion

In interviews conducted during hospital admission, homeless patients expressed positive perceptions about the necessity of their medications but also concerns about medication adverse effects. Interventions to improve adherence may be successful if directed toward addressing treatment-related concerns.
Accurate position exchange of stamen and stigma by movement in opposite direction resolves the herkogamy dilemma in a protandrous plant, Ajuga decumbens (Labiatae)
Authors: Ye Zhong-Ming , Jin Xiao-Fang , Yang Jian , Wang Qing-Feng , Yang Chun-Feng
Published: August 2019

Herkogamy is an effective way to reduce sexual interference. However, the separation of stigma and anther potentially leads to a conflict because the pollen may be placed in a location on the pollinator different from the point of stigma contact, which can reduce pollination accuracy. Floral mechanisms aiming to resolve this conflict have seldom been explored. The floral biology of protandrous Ajuga decumbens was studied to uncover how the herkogamy dilemma can be resolved. Flower anthesis was divided into male, middle, female and wilting phases. The positions of stigma and stamen were dissimilar in different flower development stages. We measured the distance of the stamen and stigma to the lower corolla lip at different floral phases, which was the pollinators’ approaching way. The pollen viability, stigma receptivity, pollen removal and pollen deposition on stigma were investigated at different phases. During the male phase, the dehisced anthers were lower than the stigma, located at the pollinators’ approaching way, and dispersed most pollen with high viability. As the flower developed, the anthers moved upwards, making way for pollen deposition during the female phase. Meanwhile, the stigma becomes receptive by moving into the way and consequently was deposited with sufficient pollen. The position exchange of the stamen and stigma created a dynamic herkogamy at the floral phase with different sexual functions. This floral mechanism effectively avoided sexual interference and maintained pollination accuracy. In Ajuga, the movement herkogamy might be of adaptive significance in response to the changes in the pollination environment.
The defensive benefit and flower number cost of selenium accumulation in Brassica juncea
Authors: Steven Janet C , Culver Alexander
Published: August 2019

Some plant species accumulate selenium in their tissues in quantities far above soil concentrations, and experiments demonstrate that selenium can serve as a defence against herbivores and pathogens. However, selenium may also cause oxidative stress and reduce growth in plants. We measured growth, selenium accumulation and herbivory in four varieties of the selenium accumulator Brassica juncea to investigate the cost of accumulation as well as its benefit in reducing herbivory. We measured selenium levels, plant size and flower number in four varieties of B. juncea watered with sodium selenate or treated as controls. We also conducted no-choice herbivory trials on leaves from both treatments with the specialist herbivore Pieris rapae. The selenate treatment slightly increased leaf number over the control, but tissue concentrations of selenium and flower number were negatively correlated in some varieties. In herbivory trials, leaves from the plants in the selenate treatment lost less leaf tissue, and the majority of larvae given leaves from selenate-treated plants ate very little leaf tissue at all. In the variety with the highest selenium accumulation, leaves from selenate-treated plants that showed reduced flower production also experienced less herbivory in feeding trials. The protective advantage of greater selenium accumulation may be offset by negative effects on reproduction, and the relatively low level of selenium accumulation in this species as compared to more extreme hyperaccumulators could reflect the minimum level necessary to enhance protection from herbivory.
Clinical Utility of Two- and Three-Dimensional Visuoconstructional Tasks in Mild Cognitive Impairment and Early Alzheimer's Disease.
Authors: Martins-Rodrigues Rafaela , da Fonsêca Égina Karoline Gonçalves , Lucena-Alves Silvia Sanaly , Contador Israel , Trojano Luigi , Grossi Dario , Fernández-Calvo Bernardino
Published: August 2019

Objective

The aim of this study was to investigate whether different types of visuoconstructional abilities are useful to distinguish individuals with mild cognitive impairment (MCI) and Alzheimer’s disease (AD) from healthy controls (HCs).

Method

We selected 20 patients with MCI and 14 with AD diagnosis based on standard criteria. The neuropsychological performance of MCI and AD groups were compared with that of a group of 11 HCs using a standard neuropsychological battery and visuoconstructional tasks that differed difficulty and type of implicated skills (graphomotor vs. non-graphomotor): two-dimensional (Clock Drawing Test, CDT; Block Design, BD; and Visual Puzzles, VP) and three-dimensional Block Construction (TBC).

Results

AD group scored significantly lower than HCs in BD, VP and TBC tasks, but no significant differences were found between HCs and MCI. CDT (copy condition) scores did not differ significantly among the groups. The receiver operating characteristic analysis showed that BD [sensitivity (se) = .85, specificity (sp) = .90, Youden index (J) = .76], VP (se = .78 and sp = .72, J = .51) and TBC (se = .71, sp = 100, J = .71) were accurate tasks to discriminate between AD and HCs. Moreover, BD tasks (se = .85, sp = .70, J = .55) and TBC (se = .71, sp = .80, J = .51) showed fair accuracy to differentiate between MCI and AD groups.

Conclusions

These findings indicate that non-graphomotor visuoconstructional tasks are already impaired in the early stages of AD, but are preserved in MCI individuals when compared with HCs.
Copula-based semiparametric regression method for bivariate data under general interval censoring
Authors: Sun Tao , Ding Ying
Published: August 2019

This research is motivated by discovering and underpinning genetic causes for the progression of a bilateral eye disease, age-related macular degeneration (AMD), of which the primary outcomes, progression times to late-AMD, are bivariate and interval-censored due to intermittent assessment times. We propose a novel class of copula-based semiparametric transformation models for bivariate data under general interval censoring, which includes the case 1 interval censoring (current status data) and case 2 interval censoring. Specifically, the joint likelihood is modeled through a two-parameter Archimedean copula, which can flexibly characterize the dependence between the two margins in both tails. The marginal distributions are modeled through semiparametric transformation models using sieves, with the proportional hazards or odds model being a special case. We develop a computationally efficient sieve maximum likelihood estimation procedure for the unknown parameters, together with a generalized score test for the regression parameter(s). For the proposed sieve estimators of finite-dimensional parameters, we establish their asymptotic normality and efficiency. Extensive simulations are conducted to evaluate the performance of the proposed method in finite samples. Finally, we apply our method to a genome-wide analysis of AMD progression using the Age-Related Eye Disease Study data, to successfully identify novel risk variants associated with the disease progression. We also produce predicted joint and conditional progression-free probabilities, for patients with different genetic characteristics.
Better-than-chance classification for signal detection
Authors: Rosenblatt Jonathan D , Benjamini Yuval , Gilron Roee , Mukamel Roy , Goeman Jelle J
Published: August 2019

The estimated accuracy of a classifier is a random quantity with variability. A common practice in supervised machine learning, is thus to test if the estimated accuracy is significantly better than chance level. This method of signal detection is particularly popular in neuroimaging and genetics. We provide evidence that using a classifier’s accuracy as a test statistic can be an underpowered strategy for finding differences between populations, compared to a bona fide statistical test. It is also computationally more demanding than a statistical test. Via simulation, we compare test statistics that are based on classification accuracy, to others based on multivariate test statistics. We find that the probability of detecting differences between two distributions is lower for accuracy-based statistics. We examine several candidate causes for the low power of accuracy-tests. These causes include: the discrete nature of the accuracy-test statistic, the type of signal accuracy-tests are designed to detect, their inefficient use of the data, and their suboptimal regularization. When the purpose of the analysis is the evaluation of a particular classifier, not signal detection, we suggest several improvements to increase power. In particular, to replace V-fold cross-validation with the Leave-One-Out Bootstrap.
Punitiveness Beyond Criminal Justice: Punishable and Punitive Subjects in an Era of Prevention, Anti-Migration and Austerity
Authors: Carvalho Henrique , Chamberlen Anastasia , Lewis Rachel
Published: August 2019

This article advances a holistic conceptualization of punitiveness that acknowledges its complexity and contemporary social and political pervasiveness. We argue that punitiveness is best understood as a phenomenological complex operating at a personal, symbolic, political and structural level, which borrows from, but extrapolates the confines of criminal justice institutions. The article examines limitations in articulations of punitiveness in criminological scholarship, and then draws on three contemporary case studies to investigate how the political deployment of anxieties and hostilities around the ‘crises’ of prevention, anti-migration and austerity reveal and reproduce punitive logics. It then outlines an original conceptual framework to argue that punitiveness ultimately revolves around the construction of, and dynamics between, punitive and punishable subjects.
Advances in the treatment of cytomegalovirus
Authors: Krishna B A , Wills M R , Sinclair J H
Published: August 2019

Background

Human cytomegalovirus (HCMV) is a threat to immunologically weak patients. HCMV cannot yet be eliminated with a vaccine, despite recent advances.

Sources of data

Sources of data are recently published research papers and reviews about HCMV treatments.

Areas of agreement

Current antivirals target the UL54 DNA polymerase and are limited by nephrotoxicity and viral resistance. Promisingly, letermovir targets the HCMV terminase complex and has been recently approved by the FDA and EMA.

Areas of controversy

Should we screen newborns for HCMV, and use antivirals to treat sensorineural hearing loss after congenital HCMV infection?

Growing points

Growing points are developing drugs against latently infected cells. In addition to small molecule inhibitors, a chemokine-based fusion toxin protein, F49A-FTP, has shown promise in killing both lytically and latently infected cells.

Areas timely for developing research

We need to understand what immune responses are required to control HCMV, and how best to raise these immune responses with a vaccine.
Tracy–Singh Product and Genetic Whale Optimization Algorithm for Retrievable Data Perturbation for Privacy Preserved Data Publishing in Cloud Computing
Authors: Revathi S Thanga , Ramaraj N , Chithra S
Published: August 2019

This paper proposes a retrievable data perturbation model for overcoming the challenges in cloud computing. Initially, genetic whale optimization algorithm (genetic WOA) is developed by integrating genetic algorithm (GA) and WOA for generating the optimized secret key. Then, the input data and the optimized secret key are given to the Tracy–Singh product-based model for transforming the original database into perturbed database. Finally, the perturbed database can be retrieved by the client, if and only if the client knows the secret key. The performance of the proposed model is analyzed using three databases, namely, chess, T10I4D100K and retail databases from the FIMI data set based on the performance metrics, privacy and utility. Also, the proposed model is compared with the existing methods, such as Retrievable General Additive Data Perturbation, GA and WOA, for the key values 128 and 256. For the key value 128, the proposed model has the better privacy and utility of 0.18 and 0.83 while using the chess database. For the key value 256, the proposed model has the better privacy and utility of 0.18 and 0.85, using retail database. From the analysis, it can be shown that the proposed model has better privacy and utility values than the existing models.
Artificial Intelligence-Based Model For Drought Prediction and Forecasting
Authors: Kaur Amandeep , Sood Sandeep K
Published: August 2019

Drought is considered as one of the most extremely destructive natural disasters with catastrophic impact on hydrological balance, agriculture outcome, wildlife habitat and financial budget. Therefore, there is a need for an efficient system to predict and forecast drought situations. There are a number of drought indices to assess the severity of droughts considering different causing factors. Most of them does not take important factors into consideration. Internet of Things (IoT) has demonstrated phenomenal growth and has successfully worked in monitoring environmental conditions. This paper proposes an IoT-enabled fog-based framework for the prediction and forecasting of droughts. At the fog layer, the dimensions of the data are decreased using singular vector decomposition. Artificial neural network with genetic algorithm classifier is used to assess drought severity category to the given event and Holt-Winters method is used to predict the future drought conditions. The proposed system is implemented using datasets from government agencies and it proves its effectiveness in assessing drought severity level.
Diet and nutritional status during early adult life have immediate and persistent effects on queen bumble bees
Authors: Woodard S Hollis , Duennes Michelle A , Watrous Kristal M , Jha Shalene
Published: August 2019

Many insects sequester nutrients during developmentally programmed periods, which they metabolize during subsequent life history stages. During these periods, failure to store adequate nutrients can have persistent effects on fitness. Here, we examined a critical but under-studied nutrient storage period in queen bumble bees: the first days of adult life, which are followed by a diapause period typically coinciding with winter. We experimentally manipulated availability of pollen (the primary dietary source of lipids and protein) and the sugar concentration of artificial nectar (the primary source of carbohydrates) for laboratory-reared queens during this period and examined three nutritional phenomena: (i) diet impacts on nutritional status, (ii) the timescale upon which nutrient sequestration occurs and (iii) the fitness consequences of nutrient sequestration, specifically related to survival across the life cycle. We found evidence that pollen and nectar starvation negatively impact lipid storage, whereas nectar sugar concentration impacts stored carbohydrates. The majority of nutrients were stored during the first ~ 3 days of adult life. Nutrients derived from pollen during this period appear to be more critical for surviving earlier life stages, whereas nutrients sequestered from nectar become more important for surviving the diapause and post-diapause periods. Negative impacts of a poor diet during early life persisted in our experiment, even when pollen and a relatively high (50%) nectar sugar concentration were provided post-diapause. Based on these findings, we posit that the nutritional environment during the early adult life of queens has both immediate and persistent impacts on fitness. These findings underscore the importance of examining effects of stage-specific nutritional limitations on physiology and life history traits in this social insect group. Moreover, the findings may shed light on how declining food resources are contributing to the decline of wild bumble bee populations.
Long-Term Bowel Function and Fate of the Ileal Pouch After Restorative Proctocolectomy in Patients With Crohn’s Disease: A Systematic Review With Meta-Analysis and Metaregression
Authors: Pellino Gianluca , Vinci Danilo , Signoriello Giuseppe , Kontovounisios Christos , Canonico Silvestro , Selvaggi Francesco , Sciaudone Guido
Published: August 2019

Background and Aims

Debate exists on whether ileal pouch anal anastomosis [IPAA] can be safely offered to patients diagnosed with Crohn’s disease [CD]. Our aim was to assess the outcome of IPAA for CD vs ulcerative colitis [UC].

Methods

We used a PRISMA/MOOSE-compliant meta-analysis. Studies published between 1993 and 2018 were retrieved. Primary end points included complications. Secondary endpoints included functional outcome. The time of CD diagnosis was considered [intentional vs incidental IPAA].

Results

Eleven studies comprising 6770 patients [CD = 352, UC = 6418] were included, with 44–120 months of follow-up. Pouch fistulae were more common in CD (CD vs UC; odds ratio (OR) 6.08; p = 0.0003, GRADE+++), as were strictures [OR 1.82; p = 0.02, GRADE+++] and failure [OR 5.27; p < 0.0001, GRADE++++]. Compared with UC, postoperative CD diagnosis was associated with a much higher risk of fistulae [OR 6.23; p = 0.006, GRADE+++] and failure [OR 8.53; p < 0.0001, GRADE++++] than intentional IPAA in CD [fistula: OR 4.17; p = 0.04, GRADE+++; failure: OR 2.48; p = 0.009, GRADE++++]. Age at surgery was positively associated with failure in CD [p = 0.007]. Obstruction was more common after intentional IPAA for CD. The risk of pouchitis did not differ between CD and UC [OR 1.07, p = 0.76, GRADE+++]. CD patients were at a higher risk of seepage [OR 2.27; p = 0.010, GRADE++].

Conclusions

Patients with CD have 5-fold higher risk of failure, and a 2-fold risk of strictures after IPAA compared with UC. The risk is much higher if diagnosis is performed after IPAA. Function in those who retain the pouch seemed similar to that of patients with UC. CD does not increase the risk of pouchitis. IPAA could be offered to a selected population of CD patients after proper preoperative counselling.

[PROSPERO registry 116811]
3D Facial morphology in children affected by spinal muscular atrophy type 2 (SMAII)
Authors: Pucciarelli Valentina , Gibelli Daniele , Mastella Chiara , Bertoli Simona , Alberti Katia , De Amicis Ramona , Codari Marina , Dolci Claudia , Battezzati Alberto , Baranello Giovanni , Sforza Chiarella
Published: August 2019

Objectives

The main objective of this study was to assess the three-dimensional facial characteristics of children affected by spinal muscular atrophy (SMA), a severe muscular disorder characterized by hypotonia, areflexia, weakness, and respiratory impairment.

Materials/Methods

Stereophotogrammetric facial scans from 22 SMA type II patients aged 2–7 years were obtained. Data were analysed using both inter-landmark distances and principal component analysis and compared with data collected from matched control subjects.

Results

Patients had wider transverse facial diameters, but smaller biocular width. Middle and lower anterior face heights were increased, whereas the mandibular ramus was shorter, with a reduced posterior-to-anterior face height ratio. Facial width-to-length ratio was reduced. In the sagittal plane, mandibular body length, and facial divergence were increased, whereas the gonial angles were decreased. In the horizontal plane, lower facial convexity was greater in patients, whereas mandibular convexity was smaller. Patients had smaller and down-slanted eye fissures, with a larger and more vertically developed nose.

Limitations

This study assessed a relatively small number of patients, due to the rare frequency of SMA type II.

Conclusions/Implications

SMA type II children possess peculiar facial alterations that may be due to the altered muscular activity. As feeding problems may derive also by malocclusion and masticatory muscular alterations, a detailed assessment of the craniofacial individual alterations should be considered in the standards of care of these patients.
Proteomics insights into the responses of Saccharomyces cerevisiae during mixed-culture alcoholic fermentation with Lachancea thermotolerans
Authors: Peng Chuantao , Andersen Birgit , Arshid Samina , Larsen Martin R , Albergaria Helena , Lametsch Rene , Arneborg Nils
Published: August 2019

The response of Saccharomyces cerevisiae to cocultivation with Lachancea thermotolerans during alcoholic fermentations has been investigated using tandem mass tag (TMT)-based proteomics. At two key time-points, S. cerevisiae was sorted from single S. cerevisiae fermentations and from mixed fermentations using flow cytometry sorting. Results showed that the purity of sorted S. cerevisiae was above 96% throughout the whole mixed-culture fermentation, thereby validating our sorting methodology. By comparing protein expression of S. cerevisiae with and without L. thermotolerans, 26 proteins were identified as significantly regulated proteins at the early death phase (T1), and 32 significantly regulated proteins were identified at the late death phase (T2) of L. thermotolerans in mixed cultures. At T1, proteins involved in endocytosis, increasing nutrient availability, cell rescue and resistance to stresses were upregulated, and proteins involved in proline synthesis and apoptosis were downregulated. At T2, proteins involved in protein synthesis and stress responses were up- and downregulated, respectively. These data indicate that S. cerevisiae was stressed by the presence of L. thermotolerans at T1, using both defensive and fighting strategies to keep itself in a dominant position, and that it at T2 was relieved from stress, perhaps increasing its enzymatic machinery to ensure better survival.
Investigating microbial indicators of anthropogenic marine pollution by 16S and 18S High-Throughput Sequencing (HTS) library analysis
Authors: Buccheri Maria Antonietta , Salvo Eliana , Coci Manuela , Quero Grazia M , Zoccarato Luca , Privitera Vittorio , Rappazzo Giancarlo
Published: August 2019

High-Throughput Sequencing technologies are providing unprecedented inventories of microbial communities in aquatic samples, offering an invaluable tool to estimate the impact of anthropogenic pressure on marine communities. In this case study, the Mediterranean touristic site of Aci Castello (Italy) was investigated by High-Throughput Sequencing of 16S and 18S rRNA genes. The sampling area falls within a Marine Protected Area and, notwithstanding, features an untreated urban wastewater discharge. Seawater samples were collected close to the wastewater output (COL) and at a second station about 400 m further off (PAN), before and after a summer increase in population. Prokaryotic communities clustered according to stations, rather than to seasons. While PAN showed a typical, not impacted, marine microbial composition, COL was consistently enriched in Epsilonproteobacteria and Firmicutes. Protist communities showed a peculiar clustering, as COL at springtime stood alone and was dominated by Ciliophora, while the other samples were enriched in Dinophyta. Analysis of alternative, detectable by High-Throughput Sequencing, microbial indicators, including both faecal- and sewage-associated, allowed uncovering the different sources of pollution in coastal and anthropogenically impacted marine ecosystems, underpinning the relevance of High-Throughput Sequencing-based screening as rapid and precise method for water quality management.