bluuebunny/crossref_metadata_2025 huggingface dataset:
The Quantification of Rainfall Variability Based on The Standardized Precipitation Index
Authors: Sanusi Wahidah , Sidjara Sahlan , Abdy Muhammad , Sudarmin
Published: June 2019

The objective of this research is to detect a pattern of rainfall in Gowa Regency using the standardized precipitation index (SPI). The SPI is a tool to investigate wetness and dryness events based on rainfall data in an area. In this study, monthly rainfall data are obtained from 6 rainfall stations. Data are collected from 1988 to 2017. The research result shows that the all stations have the highest frequency of normal condition of rainfall. Meanwhile, the frequency of both extreme wet and extreme dry events is the lowest about 2 percent in most stations. The result also shows that in general, Gowa Regency experiences very wet and very dry events with duration is one month, respectively.
Changes in Lactobacillus fabifermentans Population and Biochemical Changes during The Process of Controlled Corn Flour Fermentation and The Rheological Properties of Corn Flour Produced
Authors: Sukainah Andi , Fadilah Ratnawati , Mustarin Amirah , Putra Reski Praja , Taufieq Nur Anny Suryaningsih
Published: June 2019

This study aims to determine changes in population Lactobacillus fabifermentans (L. fabifermentans) and biochemical changes during controlled corn flour fermentation. The research is divided into two stages. The first stage was the making of starter by adding 48 hours culture on 50 g corn flour which was added 100 ml distilled water (1: 2), then incubation for 48 hours. The second stage is the application of a starter. The 48-hour starter was applied to cornstarch suspension (1: 2) by controlled method (starter concentrations of 1%, 3%, and 5%) and fermented using the microaerophilic technique at 24 hours and 48 hours intervals. The observed variables were a microbial count of Lactic Acid Bacteria (LAB), pH value and total acid on fermentation liquid, and rheological properties of modified corn flour. The results showed that the best rheological properties of corn flour fermentation resulted from the treatment of starter concentration of 1% with 24 hours fermentation time of 78000 Cps. The rheological properties of the resulting corn flour belong in referred the non-pseudoplastic Newtonian category. Where, during the fermentation process the starter concentration treatment of 1% with 24 hours fermentation time contained the amount of LAB (14.65 Log colony ml−1), pH value (5.08), and total acid (0.35%).
Correspondence Analysis of Breast Cancer Diagnosis Classification
Authors: Nadjib Bustan M. , Arif Tiro M. , Annas Suwardi
Published: June 2019

There are five indicators used in the diagnosis of breast cancer classification. The indicators are a type of malignancy, location, topography, morphology, behavior, and grade. This study aimed to assess how the relationship between types of diagnostic classification was given to breast cancer patients. The research is a quantitative method and used the hospital medical records were collected in the form of anatomical pathology examination results for hospital patients in the year 2017. Data were obtained from 317 pathology examinations which included 282 breast cancer patients. Each patient is given a diagnosis according to the pathologist’s observations into various classifications according to location, topography, type, morphology, grade, and behavior. The result of the analysis showed a relationship between the location of cancer and the type of malignancy. Furthermore, there is a difference in the probability of a malignant or benign tumor-attacking the right or left breast. Correspondence analysis was carried out between the location of the tumor with topography, type of malignancy, morphology, grade, and behavior respectively. The results showed that there was a significant correspondence between topography with the type of malignancy, type of malignancy with morphology, morphology with grade, and grade with behavior. Each type of diagnosis of breast cancer diagnosis is entirely accurate and has a significant correspondence relationship with each other.
An Intelligent Automatic Fault Detection Technique Incorporating Image Processing and Fuzzy Logic
Authors: Iftikhar Kulsoom , Anwar Shahzad , Khan Muhammad Tahir , Djawad Yasser Abd.
Published: June 2019

Fault detection is considered an important and challenging task to be incorporated in many industrial applications. It has gained interest in recent years, and many techniques have been proposed for developing an effective fault detection approach due to its significant importance in everyday life. This study presents an automated intelligent fault detection technique incorporating image processing and fuzzy logic. Image processing is the first step where features such as entropy estimation, color-based segmentation and depth estimation from gradients are obtained. The extracted features (number of {blobs, minima, maxima}, and estimated entropy) act as input to the fuzzy logic. The subsequent step incorporates fuzzy logic; the four inputs are fed to fuzzy which extract the fault and acts as knowledge rule-based tool and final step, i.e. the output generation, classifies it accordingly into four categories of faults (rust, bumps, hole, wrinkles/roller marks). The proposed method is compared with Linear Vector Quantization, and Multivariate Discriminant Function approaches. The method is tested on a database of 150 images. The proposed method demonstrated its significance and effectiveness with performance accuracy of 99%, 98%, 96.8% and 97.6% for rust, bumps, holes and wrinkles/roller marks respectively.
Physico-Mechanical Properties of Geopolymer Based on Laterite Deposit Sidrap, South Sulawesi
Authors: Subaer  , Haris Abdul , Irhamsyah A. , Akifah Nur , Amalia Nur Syamsih
Published: June 2019

Laterite soil deposit Sidrap, South Sulawesi, has been used as a raw material in the production of Na-Poly (sialate-siloxo) geopolymers. The main objective of this study is to investigate the physicomechanical properties of the resulting geopolymers synthesized from laterite Sidrap. Geopolymers were produced through the alkali-activation method of dehydroxylated laterite. Dehydroxylation was performed by using high-temperature furnace at 750°C for 4 hours. The resulting geopolymers were characterized based on X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Fourier Transform Infra Red (FTIR) and Scanning Electron Microscopy (SEM) in order to examine their mineralogy and microstructure properties. The physicomechanical properties of geopolymer were examined through compressive and flexural strength. It was found that geopolymer based on Sidrap laterite exhibited good and high mechanical strength which make them suitable for various structural applications.
Comparative Study of The Difficulty Index of Items Displayed with The Paper-Based Test and The Computer-Based Testing Paper
Authors: Syahrul  , Suhardi Iwan , Lu’mu
Published: June 2019

The focus of this study is to analyze whether there are differences in the difficulty index of items if the same items are displayed with the Paper Based Test (PBT) model and the Computer-Based Testing (CBT) model. The PBT and CBT models have the same paradigm of measuring estimated abilities but have differences in the context and feel aspects. These differences include the number of items in the range of eyesight, use of tools, how to work on items, basic knowledge needs about computer operations, and habit factors. These differences can affect the results of estimating the ability of test participants. This study uses development methods and quantitative methods. Development methods are used to develop package items and CBT software. Two groups of respondents were used with equal ability to work on the same question package. One group uses the PBT model, and the other group uses CBT so that the response choices are obtained in each test model. The results of the respondent’s answer choices were then analyzed by the ITEMAN software to get the item difficulty index. The item difficulty index of each model was tested statistically using SPSS software, whether there was a significant average difference between the two test models. From the results of the study and analysis in classical theory, it can be concluded that statistically there are differences in the average difficulty index of the items if the same item is displayed with the PBT and CBT models. It was found that the items displayed with the PBT model had a more difficult tendency than when displayed with the CBT model.
Introduction to multi-messenger astronomy
Authors: Neronov Andrii
Published: June 2019

The new field of multi-messenger astronomy aims at the study of astronomical sources using different types of “messenger” particles: photons, neutrinos, cosmic rays and gravitational waves. These lectures provide an introductory overview of the observational techniques used for each type of astronomical messenger, of different types of astronomical sources observed through different messenger channels and of the main physical processes involved in production of the messenger particles and their propagation through the Universe.
Ground-based Gamma-Ray Astronomy: an Introduction
Authors: Sciascio Giuseppe Di
Published: June 2019

During the last two decades Gamma-Ray Astronomy has emerged as a powerful tool to study cosmic ray physics. In fact, photons are not deviated by galactic or extragalactic magnetic fields so their directions bring the information of the production sites and are easier to detect than neutrinos. Thus the search for γ primarily address in the framework of the search of cosmic ray sources and to the investigation of the phenomena in the acceleration sites. This note is not a place for a review of ground-based gamma-ray astronomy. We will introduce the experimental techniques used to detect photons from ground in the overwhelming background of CRs and briefly describe the experiments currently in data taking or under installation.
Introduction to Black Holes
Authors: Kunz Jutta
Published: June 2019

In these lectures an introduction to black holes in general relativity is presented. First the Schwarzschild black hole and its properties are discussed by studying the geodesics of light and matter. Several coordinate systems are introduced, and the maximal analytic extension of the Schwarzschild solution is obtained, including a white hole, a second universe, and a non-traversable wormhole. Subsequently the properties of the rotating Kerr black hole are discussed. These include, in particular, the ring singularity, the horizons, frame dragging and the ergoregion. As an interesting astrophysical application the photon region and the black hole shadow are addressed.
Composite structural elements of overhead lines as a means of increasing technical efficiency
Authors: Byk F , Kityshin V , Myshkina L , Kaminskaya E
Published: June 2019

Innovations in engineering and technologies depend not so much on emergence of new properties of the equipment, production process, system of management of the enterprise, but to a greater extent on their occurrence in the necessary set of combination. Technical and economic indicators reflecting technical and economic efficiency are usually used as characteristics. The degree of technical efficiency is determined by a combination of three properties – safety, reliability and productivity. These basic properties determine the economic effect of an innovative product performing certain functions, enabling to estimate their usefulness and significance. One of the means of increasing the overhead lines technical efficiency in the electric grid is the introduction of composite structural elements. The overhead line model is proposed for assessing the impact of elements on reliability as a component of technical efficiency. Changes in the reliability of the line when introducing innovative elements are calculated and priorities are defined.
Method development for the thermotechnical calculations utilizing reduced characteristics of the RDF fuels
Authors: Kornilova N V , Trubaev P A
Published: June 2019

The paper presents method of calculation of the heat leakage and efficiency by using method of indirect heat balance, utilizing data from gas analysis, which can be employed for operational evaluation plant operation during burning of different types of waste materials. Taking into account that practically only oxygen and carbon dioxide is being measured in the exhaust gases, calculation method for heat leakage with exhaust gases, using measurements of only this component, without utilizing carbon dioxide content in combustion products, was developed. Carbon dioxide and oxygen calculated percentage content in dry complete combustion products in actual air consumption was measured with consideration of incomplete combustion. Heat leakage for low power boilers and furnaces was analyzed, heat leakage calculation method for this kind of plants was introduced. Using design factors analysis of the solid fuel boilers for burning low-calorie fuel and wood waste, was developed dependence of the outside walls specific area of the boiler on the boiler’s efficiency. Based on the developed method for seven types of the RDF fuels, tabular and graphic dependences for reduced factors, characterizing heat leakage to the atmosphere and incomplete combustion, were introduced. Suggested method was tested for calculating losses in solid fuel water heating boiler with grate stoker and designed output power of 200 kW during burning of the briquetted waste materials.
The study of energy performance of biogas from agricultural waste
Authors: Suslov D Y , Ramazanov R S
Published: June 2019

The article is devoted to determination of energy indicators of the alternative source of energy - biogas derived from agricultural waste. The main energy indicators of the burning process of biogas fuel are lower heat value, Wobbe index, ignition range, flame propagation rate, as well as amount of oxygen and air required for complete combustion of biogas. The energy indicators of biogas produced from corn silage, technical fat, pig manure, cattle manure and poultry droppings are determined during the study. It has been found out that biogas obtained from technical fat and poultry droppings is characterized by the highest energy indicators, and biogas from corn silage - by the lowest indicators. Wobbe index of biogas is more than 2 times lower than index of natural gas. The biogas produced from technical fat has the highest rate of flame propagation - 23 cm/s, which is 1.5 times lower than the rate of flame of natural gas. Biogas has a wider ignition range than natural gas: the lower limit, the upper limit. The average value of the theoretic air volume required for complete combustion of biogas is 5.8 m3, which is 1.7 times less than the value for natural gas.
In-service performance of hybrid geopolymer binders based class F fly ash
Authors: Kozhukhova N I , Teslya A Yu , Kozhukhova M I , Zhernovsky I V , Yermak S N , Ogurtsova Yu N
Published: June 2019

Production of high-performance construction materials, meeting the requirements of construction process when development of up-to-date buildings and structures is very relevant and requires the usage of effective polycomponent binding systems, including geopolymers This work studied mechanical performance, as well as strength, water absorption and water resistance of portland cement – Class F fly ash – NaOH hybrid geopolymer binding system. The bench scale testing was conducted on different mixes, including regular portland cement-based and Class F fly ash-NaOH geopolymer binders used as reference compositions. The developed hybrid binders demonstrated, that incorporation of portland cement up to 40% as a modifying agent, reduces the formation of water soluble mineral phases such as sodium carbonates and hydroxycarbonates in low reactive class F fly ash geopolymer binders. It was found, that the presence of portland cement in the system positively affects strength development and noticeably reduces water absorption and improves water resistance of the developed binders, which is related to formation of water resistant and stable calcium hydrosilicate phases (C-S-H)
Investigation of cavitation and vibration processes in the technology of treatment of the contaminated liquids
Authors: Sevostyanov V S , Belykh M M , Sevostyanova K I
Published: June 2019

This article considers the problems of treatment of contaminated liquids. Scientific works of home and foreign authors were analysed and according to this analysis it was made the conclusion. Experimental studies of the process of treatment of the contaminated liquids, in which the cavitation process in the technology of treatment of the contaminated media were investigated, as well as the process of treatment of the contaminated media in a vibration and centrifugal unit . As a result of the research, it was discovered that the cavitation method can be effectively used to treat water from heavy mechanical impurities, which makes it possible to carry out further filtration in fine filters. A vibration-rotary unit, developed in Belgorod State Technological University n.a. V G Shukhov, (Russia) at the Department of Technological Complexes, Machines and Mechanisms, was taken as a technical object, where experimental investigation of treatment of the contaminated liquids was carried out. It was also carried out the research of the stepwise process of treatment of the contaminated liquids in the developed unit. On the basis of these results the authors propose to use a stepwise method of treatment of liquid media: cavitation effect - for the preliminary phase of treatment and vibration-rotary effect – for the final stage of treatment.
Modeling of the distribution of thermal fields during spark plasma sintering of alumina ceramics
Authors: Berendeev N N , Popov A A , Pyaterikova V V , Boldin M S , Nokhrin A V , Chuvil’deev V N , Lantsev E A
Published: June 2019

The article shows the use of an experimental-calculation method for the refinement of thermoelectric constants of graphite materials and alumina ceramics by experimentally studying the heating of graphite equipment and refinement thermoelectric constants of materials using the finite element method (ANSYS WORKBENCH). To simulate the thermal fields of graphite equipment based of the data on electric current, voltage and heat exchange conditions, a coupled boundary electric and non-stationary temperature problem was realized. The application of the developed approach made it possible to clarify the thermoelectric constant of materials, which helped to reduce the difference between the experimental and simulated temperatures from 20 to 5%.
Evaluation of tensile strength of nuclear fuel samples
Authors: Goltsev V Y , Osintsev A V
Published: June 2019

For estimation of the strength of the nuclear fuel material as well and for further refinement of nuclear fuel test technology we propose to use small discoid samples, similar in shape to the elements of nuclear fuel in the context of “Brazilian test”. We present here the results of testing small discoid specimens with and without center hole, made of brittle materials, such as cast iron and graphite (both being considered as possible model materials for the nuclear fuel). We compared these materials to nuclear fuel itself (as represented by uranium dioxide). The type of deformation and fracture found in samples made from cast iron suggests that this material cannot be used as a model for the nuclear fuel. In addition, the effect of the specimen size on resistance to destruction was investigated. The results obtained in tests on samples of graphite ARV-1 were in good agreement with the results of tests on uranium dioxide. Using the data obtained in this study, a calculation formula for determining the strength of the nuclear fuel material based on the “Brazilian test” results is proposed.
Advanced methods for consolidation of powder materials by impulse electromagnetic fields
Authors: Grigoryev E G
Published: June 2019

Advanced technologies for the production of new materials and, in particular, nanostructured materials, using powder technologies require fundamentally new approaches for the formation and preservation of a given structural-phase state. Precision control of the state of materials in the process of consolidating powders of nanomaterials can be carried out using pulsed electromagnetic fields. The aim of the project is to study the effect of high-voltage and low-voltage pulsed electromagnetic fields in the technologies of powder consolidation. The experimental devices of spark-plasma sintering, flash-sintering, high-voltage consolidation and magnetic-pulse compaction are used in our laboratory for the production of advanced materials from metal powders, ceramic and composite powders. We can produce boron carbide, silicon carbide, uranium nitride, tungsten carbide - cobalt - diamond composites, tungsten heavy alloys, and others by electromagnetic methods of powder consolidation. Experimental results to consolidation metal powders, ceramic and composites powders by electromagnetic methods presage fruitful results.
Effect of nanosized titanium and silicon carbides on synthesis and consolidation of titanium silicon carbide during spark plasma sintering
Authors: Kulmet’eva V B , Kachenyuk M N , Oglezneva S A , Smetkin A A
Published: June 2019

Using spark plasma sintering method, at temperature T = 1400°C and load of 30 MPa samples of composite material Ti3SiC2/TiC were obtained. Before SPS powder mixtures with molar ratio 3Ti-1.25SiC-0.75C with addition of up to 4% wt of nanopowders of titanium carbide or silicon carbide were mechanically activated in a planetary mill. Material structure was studied using X-ray structural analysis, hardness and fracture toughness was evaluated on basis of Vicker’s indentation results. It was established that introduction of nanocarbides up to 1% wt significantly reduces contents of Ti3SiC2, and further on practically has no influence on phase composition. Increase of isothermal time from 5 to 15 min leads to an increase in the TixSiy secondary phases to 11–14%. Introduction of nano-TiC and nano-SiC into mixtures increases crack fracture toughness to 7.06–7.55 MPa·m1/2 for samples after 5 min of SPS and practically does not change it after 15 min of SPS.
Processing of Al–Zn–Mg–Cu/SiC composite prepared by mechanical alloying
Authors: Kurbatkina E I , Shavnev A A , Grishina O I , Gololobov A V
Published: June 2019

In the present work, using powder metallurgy method, mechanical alloying and extrusion, the metal matrix composite material Al–Zn–Mg–Cu/10% SiC was obtained. Phase transformations occurring during heat treatment were studied. After deformation aluminum solid solution, MgZn2 and SiC are present in the composite material. The X-ray phase analysis and TEM results showed that when the composite material is heated for quenching, the MgZn2 phase is completely dissolved. Study of the aging kinetics showed that the peak of aging of the composite material was achieved in 15 h, which is much faster than in the matrix alloy (24 h). After aging, the solid solution decomposition products appear in the form of a metastable η'- phase (MgZn2), looking like rods located in three mutually perpendicular directions <100> Al.
Combined equipment for synthesis of ultrafine metals and metal compounds powders via Flow-Levitation and crucible methods.
Authors: Kuskov M L , Zhigach A N , Leipunsky I O , Gorbachev A N , Afanasenkova E S , Safronova O A
Published: June 2019

Laboratory automated equipment for synthesis of ultrafine particles of metals, alloys and metal compounds via evaporation-condensation Flow-Levitation Guen-Miller method combined with crucible method using high-frequency (440 kHz) electromagnetic field for heating is described. The equipment synthesizes the said particles and multilayer core-shell structures with mean size ranging from tens to hundreds of nanometers with output from grams to tens of grams per hour. Synthesized particles may be collected into container with inert gas, or into non-volatile liquid, or in situ passivated with air for further handling. Examples of synthesized particles are presented.
Prospective SHS composites for high-temperature applications
Authors: Levashov E A , Kurbatkina V V , Vorotilo S , Pogozhev Yu S , Patsera E I
Published: June 2019

In this article, a succinct review of the SHS ceramics prospective for the high-temperature applications is provided. Macrokinetic features and mechanisms of combustion and structure formation were studied for the systems Ta–Zr–C, Ta–Hf–C, Zr–Ta–B, Hf–Ta–B, Zr–B–Si–C, Ta–Si–C, Mo–Hf–Si–B, and Zr–Ta–B–Si. Materials were produced by the combination of SHS with hot pressing (HP) and spark plasma sintering (SPS), and their structure and properties were investigated.
Experimental studies of the fundamental mechanism for phase formation in reactive solutions toward creation of the functional materials
Authors: Roslyakov S I , Moskovskikh D O , Nepapushev A A , Kuskov K V , Trusov G V , Sedegov A S , Mukasyan A S , Manukyan K V
Published: June 2019

In this work, we examined several modifications of solution combustion synthesis (SCS) method to produce new nanoscale non-oxide phases (nitrides, intermetallics, and alloys). In particularly two approaches were outlined: (i) so-called, catalytic SCS, where existence of one metal promotes reduction during combustion; (ii) synthesis by using media, which contains both reactive solution and solid metals, i.e. combination of solution and heterogeneous combustion.
Thermally coupled processes in a composite granular mixture (Ni + Al)–(Ti + C)
Authors: Seplyarskii B S , Kochetkov R A , Lisina T G , Abzalov N I
Published: June 2019

For the first time combustion of a thermally conjugated granulated mixture consisting of the mixture of Ni + Al and Ti + C granules, differing in burning velocity and temperature has been investigated experimentally in co-current flows of argon and nitrogen. It has been established that in the whole investigated gas flow rates the ignition of Ni + Al granules occurs in the combustion front. The high efficiency of Ti + C donor granules energy usage has been shown, since the time of heat exchange between the granules does not depend on the sample size, but is determined only by the characteristics of internal heat transfer. A strong increase in the burning rate of the composite mixture at low nitrogen flow rates has been explained via interaction of aluminum with nitrogen and effective reduction of heat loss of the donor. The possibility of isolating the target synthesis product was shown even if its melting point is below the adiabatic temperature of combustion of the composite mixture.
Effect of Calcination Temperature and Support Type of Pt/WOx/boehmite Catalyst on 1,3-propanediol Production from Hydrogenolysis of Glycerol
Authors: Uttraporn P , Praserthdam P
Published: June 2019

Hydrogenolysis of glycerol to 1,3-PDO was tested over different catalysts. To enhance 1,3-PDO selectivity, our work raised the calcination temperature from 800 °C to 900 °C that promoted Bronsted acidity, glycerol conversion and 1,3-PDO selectivity under the mild reaction condition (140 °C, 0.5 MPa). Glycerol conversion gradually raised from 32.8% to 36.6% and 1,3-PdO selectivity mildly increased from 18.2% to 21.2%. The loading of SiO2 into Pt/WOx/γ-Al2O3 had extremely favourable effects on 1,3-PDO selectivity because the amount of Bronsted acid sites increased significantly as confirmed by NH3-IR.
Role of land quality in corn acreage response to price and policy changes: evidence from the Western Corn Belt
Authors: Uludere Aragon Nazli Z
Published: June 2019

Land quality influences how farmers allocate croplands in response to market forces. Farmers in the Western Corn Belt (WCB) have historically utilized the highest quality lands for corn cultivation, putting lower quality lands to other uses. This paper questions whether high corn prices influenced expansion of corn cultivation on lower quality lands, and the role played by US biofuel policy in such land use change. Using three decades of data, I estimate that the proportional change in corn acreage to rising corn prices is nearly three times larger in counties with lowest land quality versus those with the highest land quality. This variable response, however, is driven by the changes in cropland use for corn cultivation after 2006, the period following the change in US biofuel policy, and punctuated by two crop price spikes. Marginal agricultural lands and other lower quality lands, such as grasslands used for range or pasture, are therefore prone to conversion into corn cropping disproportionately during high price periods. High price responsiveness of lower quality lands also suggests these lands may cycle in and out of corn cropping opportunistically. This has implications for marginal land availability for bioenergy crops, and poses environmental concerns to the extent lower quality lands are also more environmentally sensitive.
Can the weakening of Indian Monsoon be attributed to anthropogenic aerosols?
Authors: Saha Anamitra , Ghosh Subimal
Published: June 2019

Literature found that the increasing concentration of Anthropogenic Aerosol (AA) is the key reason behind the weakening trend of Indian Summer Monsoon Rainfall (ISMR), based on the Coupled Model Intercomparison Project Phase5 (CMIP5) simulations with AA-only forcing. Here, we re-examine and find that AA-only simulations show country-wide drying, in contrast to the observed east-west asymmetry in the recent ISMR trend. For further evaluation, we decompose the changes in moisture convergence during summer monsoon into dynamic and thermodynamic components. We find that multi-run ensemble averages for individual CMIP5 models do not capture the observed dominance of the changes in dynamic component over the thermodynamic one. An optimal fingerprinting technique for detection and attribution also fail to attribute the changes in ISMR to AA, either because of large internal variability and/or intermodel spread. This implies the need for more careful assessment of AA-only simulations for the ISMR before attributing the changes to AA.
Consumer Preferences for Country‐of‐Origin Labeling in Protected Markets: Evidence from the Canadian Dairy Market
Authors: Norris Amanda , Cranfield John
Published: June 2019

Recent trade agreements will expand Canada's market access commitments for dairy products. We explore whether Canadian consumers will respond to the increased presence of imported dairy products using a discrete choice experiment that accounts for price, country‐of‐origin (COO), production method, brand, and traceability. We use four processed dairy products to illustrate potential trade‐offs: Gouda and cheddar cheese, ice cream, and yogurt. There are statistically significant discounts associated with COO effects. These discounts vary with the dairy product and are large compared to consumer valuation of other included attributes. We find large premiums for traceability programs, suggesting that the absence of assurances related to traceability may mute actual market penetration arising from increased access to the Canadian dairy market.
How to Teach Laboratory Stewardship in the Undergraduate Medical Curriculum?
Authors: Roth Christine G , Huang William Y , Caruso Andrew C , Sekhon Navdeep , Kung Doris H , Greely Jocelyn T , Du Ye B , Holder-Haynes Juliet G , Little Jenelle E , Fielder Elaine K , Ismail Nadia J
Published: June 2019

Objectives

Promotion of high-quality care at a lower cost requires educational initiatives across the continuum of medical education. A needs assessment was performed to inform the design of an educational tool with the goal of teaching laboratory stewardship to medical students.

Methods

The needs assessment consisted of semistructured interviews with core clerkship directors and residency program directors at our institution, a national survey to the Undergraduate Medical Educators Section (UMEDS) of the Association of Pathology Chairs, and a review of existing online resources that teach high-value care.

Results

Two major themes emerged regarding opportunities to enhance laboratory stewardship education: appropriate ordering (knowledge of test indications, pretest/posttest probability, appropriateness criteria, recognition of unnecessary testing) and correct interpretation (understanding test specifications, factors that affect the test result, recognizing inaccurate results).

Conclusions

The online educational tool will focus on the curricular needs identified, using a multidisciplinary approach for development and implementation.
Peripheral T-Cell Lymphoma Arising in Patients With Chronic Lymphocytic Leukemia
Authors: Van Der Nest Bianca M , Leslie Connull , Joske David , Radeski Dejan , White Rohen , Cheah Chan Yoon
Published: June 2019

Objectives

To describe three further cases of anaplastic large cell lymphoma (ALCL) occurring in patients with preexisting chronic lymphocytic leukemia (CLL). We also reviewed the literature of previously published cases.

Methods

We discuss the clinical features, histopathology, and outcomes for three patients with ALCL and CLL from Perth, Australia. The cases were also included in a literature review of existing cases and comparisons were made with our cohort.

Results

The three patients included two men (aged 77 and 74 years) and one woman (aged 66 years). All had a history of untreated CLL with diagnosis established 4 to 16 years before. They had lymphadenopathy and/or cutaneous/soft tissue lesions that proved to be ALCL, ALK+ (one case) or ALCL, ALK– (two cases).

Conclusions

Further research is required in this area to establish prognostic and management recommendations. Increasing numbers of cases are being described. Positron emission tomography with computed tomography was not useful in our cohort for diagnosing progression.
Comprehensive study of the exposome and omic data using rexposome Bioconductor Packages
Authors: Hernandez-Ferrer Carles , Wellenius Gregory A , Tamayo Ibon , Basagaña Xavier , Sunyer Jordi , Vrijheid Martine , Gonzalez Juan R
Published: June 2019

Genomics has dramatically improved our understanding of the molecular origins of certain human diseases. Nonetheless, our health is also influenced by the cumulative impact of exposures experienced across the life course (termed ‘exposome’). The study of the high-dimensional exposome offers a new paradigm for investigating environmental contributions to disease etiology. However, there is a lack of bioinformatics tools for managing, visualizing and analyzing the exposome. The analysis data should include both association with health outcomes and integration with omic layers. We provide a generic framework called rexposome project, developed in the R/Bioconductor architecture that includes object-oriented classes and methods to leverage high-dimensional exposome data in disease association studies including its integration with a variety of high-throughput data types. The usefulness of the package is illustrated by analyzing a real dataset including exposome data, three health outcomes related to respiratory diseases and its integration with the transcriptome and methylome.

Availability and implementation

rexposome project is available at https://isglobal-brge.github.io/rexposome/.

Supplementary information

Supplementary data are available at Bioinformatics online.
Nematodes as evolutionary commuters between marine, freshwater and terrestrial habitats
Authors: Holterman Martijn , Schratzberger Michaela , Helder Johannes
Published: June 2019

Nematodes are the only major metazoan group which is persistently abundant and diverse across marine, freshwater and terrestrial ecosystems. This could be the result of a few major habitat transitions followed by extensive diversification, or numerous habitat transitions followed by moderate diversification. To pinpoint habitat transitions, we superposed nematode habitat associations on an available phylum-wide phylogenetic tree based on small subunit ribosomal DNA sequences (≈2730 SSU rDNA sequences covering ≈1750 nematode taxa). Our analysis revealed at least 30 major habitat transitions within the phylum Nematoda. These transitions as well as their directionality were unevenly spread over the 12 major clades. Most transitions reside in Clades 1–6, and these transitions are bidirectional. Members of Clades 8–12 showed five full transitions, and these took place exclusively from terrestrial to marine systems. We relate our results to the distinct secretory–excretory systems in Clades 1–6 and Clades 8–12, as well as to differences in water permeability of the nematode cuticle. Hence, the phylum Nematoda is characterized by a relatively large number of habitat transitions followed by moderate diversification. The identification of multiple habitat transitions at a low taxonomic level will facilitate future investigations into the mechanisms underlying this unusual ecological flexibility.
On nonparametric maximum likelihood estimation with double truncation
Authors: Xiao J , Hudgens M G
Published: June 2019

Doubly truncated survival data arise if failure times are observed only within certain time intervals. The nonparametric maximum likelihood estimator is widely used to estimate the underlying failure time distribution. Using a directed graph representation of the data suggested by Vardi (1985), a certain graphical condition holds if and only if the nonparametric maximum likelihood estimate exists and is unique. If this condition does not hold, then such an estimate may exist but need not be unique, so another graphical condition is proposed to check whether such an estimate exists. The conditions are simple to check using existing graphical software. Reanalysis of an AIDS incubation time dataset shows that a nonparametric maximum likelihood estimate does not exist for these data.
Acquisition of visual priors and induced hallucinations in chronic schizophrenia
Authors: Valton Vincent , Karvelis Povilas , Richards Katie L , Seitz Aaron R , Lawrie Stephen M , Seriès Peggy
Published: June 2019

Prominent theories suggest that symptoms of schizophrenia stem from learning deficiencies resulting in distorted internal models of the world. To test these theories further, we used a visual statistical learning task known to induce rapid implicit learning of the stimulus statistics. In this task, participants are presented with a field of coherently moving dots and are asked to report the presented direction of the dots (estimation task), and whether they saw any dots or not (detection task). Two of the directions were more frequently presented than the others. In controls, the implicit acquisition of the stimuli statistics influences their perception in two ways: (i) motion directions are perceived as being more similar to the most frequently presented directions than they really are (estimation biases); and (ii) in the absence of stimuli, participants sometimes report perceiving the most frequently presented directions (a form of hallucinations). Such behaviour is consistent with probabilistic inference, i.e. combining learnt perceptual priors with sensory evidence. We investigated whether patients with chronic, stable, treated schizophrenia (n = 20) differ from controls (n = 23) in the acquisition of the perceptual priors and/or their influence on perception. We found that although patients were slower than controls, they showed comparable acquisition of perceptual priors, approximating the stimulus statistics. This suggests that patients have no statistical learning deficits in our task. This may reflect our patients’ relative wellbeing on antipsychotic medication. Intriguingly, however, patients experienced significantly fewer (P = 0.016) hallucinations of the most frequently presented directions than controls when the stimulus was absent or when it was very weak (prior-based lapse estimations). This suggests that prior expectations had less influence on patients’ perception than on controls when stimuli were absent or below perceptual threshold.
Specialized Somatosensory–Motor Integration Functions in Musicians
Authors: Hirano Masato , Kimoto Yudai , Furuya Shinichi
Published: June 2019

Somatosensory signals play roles in the fine control of dexterous movements through a somatosensory–motor integration mechanism. While skilled individuals are typically characterized by fine-tuned somatosensory functions and dexterous motor skills, it remains unknown whether and in what manner their bridging mechanism, the tactile–motor and proprioceptive–motor integration functions, plastically changes through extensive sensorimotor experiences. Here, we addressed this issue by comparing physiological indices of these functions between pianists and nonmusicians. Both tactile and proprioceptive stimuli to the right index finger inhibited corticospinal excitability measured by a transcranial magnetic stimulation method. However, the tactile and proprioceptive stimuli exerted weaker and stronger inhibitory effects, respectively, on corticospinal excitability in pianists than in nonmusicians. The results of the electroencephalogram measurements revealed no significant group difference in the amplitude of cortical responses to the somatosensory stimuli around the motor and somatosensory cortices, suggesting that the group difference in the inhibitory effects reflects neuroplastic adaptation of the somatosensory–motor integration functions in pianists. Penalized regression analyses further revealed an association between these integration functions and motor performance in the pianists, suggesting that extensive piano practice reorganizes somatosensory–motor integration functions so as to enable fine control of dexterous finger movements during piano performances.
Human Immunodeficiency Virus Pre-exposure Prophylaxis and Increased Incidence of Sexually Transmitted Infections in the United States
Authors: Serpa Jose A , Huynh Gabriel N , Nickell Julie B , Miao Hongyu
Published: June 2019

Background

Human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP) decreases HIV transmission. Some studies have raised concerns about a potential association between the implementation of HIV PrEP and the growing incidence rates of sexually transmitted infections (STIs) in the United States.

Methods

We conducted a quasi-experimental (interrupted time series) analysis of STI (syphilis, gonorrhea, and chlamydia) rates before (2000–2012) and after (2013–2017) the implementation of HIV PrEP. We also performed correlations between HIV PrEP utilization and STI cases at the national (2012–2017) and state (2017) levels. We defined HIV PrEP utilization as the number of people taking tenofovir disoproxil fumarate/emtricitabine for HIV prevention.

Results

HIV PrEP implementation was associated with 25% (relative risk [RR] 1.254, 95% confidence interval [CI] 1.245–1.263; P < .001) and 26% (RR 1.260, 95% CI 1.257–1.264; P < .001) increases in syphilis and gonorrhea rates, respectively, and a 12% reduction in chlamydia rates (RR: 0.884, 95% CI 0.883–0.885; P < .001). HIV PrEP utilization was correlated with the numbers of syphilis, gonorrhea, and chlamydia cases (spearman coefficients 1.00, 0.94, and 0.94, respectively; P < .001, P < .01, and P < .01, respectively). At the state level, HIV PrEP was also correlated with the number of cases of syphilis, gonorrhea, and chlamydia (spearman coefficients 0.85, 0.81, and 0.85, respectively; Ps < .001 for all correlations).

Conclusions

The implementation and utilization of HIV PrEP in the United States were associated with increased rates of STIs. Further studies to confirm these associations and to elucidate potential causes are needed.
Creatinine clearance after cimetidine administration in a new short procedure: comparison with plasma and renal clearances of iohexol
Authors: Stehlé Thomas , El Karoui Khalil , Sakka Mehdi , Ismail Ahmad , Matignon Marie , Grimbert Philippe , Canoui-Poitrine Florence , Prié Dominique , Audard Vincent
Published: June 2019

Background

Creatinine clearance after cimetidine administration (Cim-CreatClr) was once proposed as a method of glomerular filtration rate (GFR) measurement, but has been largely abandoned. We investigated whether a new short procedure for Cim-CreatClr determination could be considered an appropriate method for GFR measurement.

Methods

A 150-min protocol involving oral cimetidine administration was developed to determine Cim-CreatClr. In total, 168 patients underwent simultaneous assessments of creatinine clearance before and after cimetidine administration [basal creatinine clearance (Basal-CreatClr) and Cim-CreatClr, respectively], renal iohexol clearance and plasma iohexol clearance (R-iohexClr and P-iohexClr, respectively). We compared the agreement between the various methods of GFR measurement, using Bland–Altman plots to determine biases, precisions (standard deviation of the biases) and accuracy (proportions of GFR values falling within 10, 15 and 30% of the mean: P10, P15 and P30, respectively).

Results

After cimetidine administration, Basal-CreatClr decreased by 19.8% [95% reference limits of agreement (95% LoA): −2.2 to 41.7%]. The bias between Cim-CreatClr and P-iohexClr was −0.6% (95% LoA −26.8 to 28%); the precision was 14.0%; P10, P15 and P30 were 57.1% [95% confidence interval (95% CI) 49.3 to 64.7%], 73.2% (95% CI 65.8 to 79.7%) and 97.0% (95% CI 93.2 to 99.0%), respectively. Due to the positive bias (16.7%; 95% LoA −3.6 to 36.9%) of Cim-CreatClr relative to R-iohexClr, accuracy of Cim-CreatClr relative to R-iohexClr was poor despite a good precision (10.3%).

Conclusions

Our study shows a high level of agreement between Cim-CreatClr and P-iohexClr. These results suggest that this short Cim-CreatClr procedure is a valid method for GFR measurement, which might be useful, in particular, in situations in which P-iohexClr is not suitable or not available.
Sex and regional differences in myocardial plasticity in aortic stenosis are revealed by 3D model machine learning
Authors: Bhuva Anish N , Treibel Thomas A , De Marvao Antonio , Biffi Carlo , Dawes Timothy J W , Doumou Georgia , Bai Wenjia , Patel Kush , Boubertakh Redha , Rueckert Daniel , O’Regan Declan P , Hughes Alun D , Moon James C , Manisty Charlotte H
Published: June 2019

Aims

Left ventricular hypertrophy (LVH) in aortic stenosis (AS) varies widely before and after aortic valve replacement (AVR), and deeper phenotyping beyond traditional global measures may improve risk stratification. We hypothesized that machine learning derived 3D LV models may provide a more sensitive assessment of remodelling and sex-related differences in AS than conventional measurements.

Methods and results

One hundred and sixteen patients with severe, symptomatic AS (54% male, 70 ± 10 years) underwent cardiovascular magnetic resonance pre-AVR and 1 year post-AVR. Computational analysis produced co-registered 3D models of wall thickness, which were compared with 40 propensity-matched healthy controls. Preoperative regional wall thickness and post-operative percentage wall thickness regression were analysed, stratified by sex. AS hypertrophy and regression post-AVR was non-uniform—greatest in the septum with more pronounced changes in males than females (wall thickness regression: −13 ± 3.6 vs. −6 ± 1.9%, respectively, P < 0.05). Even patients without LVH (16% with normal indexed LV mass, 79% female) had greater septal and inferior wall thickness compared with controls (8.8 ± 1.6 vs. 6.6 ± 1.2 mm, P < 0.05), which regressed post-AVR. These differences were not detectable by global measures of remodelling. Changes to clinical parameters post-AVR were also greater in males: N-terminal pro-brain natriuretic peptide (NT-proBNP) [−37 (interquartile range −88 to −2) vs. −1 (−24 to 11) ng/L, P = 0.008], and systolic blood pressure (12.9 ± 23 vs. 2.1 ± 17 mmHg, P = 0.009), with changes in NT-proBNP correlating with percentage LV mass regression in males only (ß 0.32, P = 0.02).

Conclusion

In patients with severe AS, including those without overt LVH, LV remodelling is most plastic in the septum, and greater in males, both pre-AVR and post-AVR. Three-dimensional machine learning is more sensitive than conventional analysis to these changes, potentially enhancing risk stratification.

Clinical trial registration

Regression of myocardial fibrosis after aortic valve replacement (RELIEF-AS); NCT02174471. https://clinicaltrials.gov/ct2/show/NCT02174471.