bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Entrepreneurial Competencies of Employees within the Framework of internal Entrepreneurship Programs in the Region
Authors: Pesha Anastasiya , Shavrovskaya Marina , Borodina Oksana
Published: January 2021

The global economic environment is becoming more active and complex. Technological and social changes affect the internal processes of companies associated with the diversification of production, the introduction of new lines of products and services, the modernization of business processes. In this article, the authors present the results of a study into the ways ten large industrial companies (fuel, chemical and petrochemical, food industry, defence industry and agricultural technology) in the Omsk region develop domestic internal entrepreneurship. As a result of narrative interviews with HR directors of the selected companies, the authors formulated two approaches to the development of internal entrepreneurship. The first method is based on the development of a creative environment that stimulates the generation of initiatives to improve business. The second method involves companies implementing business projects through employee development programs. The advantages and disadvantages of both methods are subsequently highlighted. The conclusions draw attention to the problems of the development of internal entrepreneurship within large industrial companies and the need to create a special environment and infrastructure to promote the business initiatives of employees.
Formation of Entrepreneurial Skills in Students in a Changing World
Authors: Salun Maryna , Zaslavska Kateryna , Vaníčková Radka , Šindelková Kristýna
Published: January 2021

In today's global world, a number of concepts exist for the typology of a manager's personality. The personality of a manager is evident through their daily practical actions and the degree of validity thereof. The entrepreneurial skills of students is related to whether they view entrepreneurship as a career alternative. The purpose of educating successful managers is to enable them to apply and implement the principles of managerial skills in business practice. This includes the fulfilment of managerial roles and the use of basic tools to accomplish this, the principles of coaching, the creation and effective management of work teams, and knowledge of HRM techniques such as brainstorming. The aforementioned is based on the assumption that the desired result can be effectuated by one factor, but also by a combination of several factors. Qualitative comparative analysis (QCA) was therefore applied to the demands for entrepreneurial skills on the labour market and the presence of this issue in the curricula of Ukrainian universities.
Gefäßzugänge bei Kindern: Technik, Komplikationen und Fallstricke beim zentralen Venenkatheter
Authors: Schindler Ehrenfried , Mikus Marian , Velten Markus
Published: January 2021

Kinder mit komplexen Erkrankungen benötigen häufig einen zentralvenösen Katheter für die intraoperative Anwendung, zur parenteralen Ernährung, zur mehrfachen Blutentnahme und zur Verabreichung von Medikamenten. Heute gelten ultraschallbasierte Techniken als Goldstandard. In diesem Artikel werden Standardpositionen wie auch neue Alternativen vorgestellt.
Pain Alleviation and Opioid Weaning in an 80-Year-Old with Chronic Foot Pain Following Injection Therapy with Perineural Dexmedetomidine and Dexamethasone
Authors: Berger Amnon A. , Urits Ivan , Hasoon Jamal , Kaye Alan D. , Viswanath Omar , Eskander Jonathan
Published: January 2021

Opiates are routinely used for chronic pain patients, and up to 44% of them will have a prescription for an opiate medication for pain alleviation. However, of the 76 million adults prescribed opiates for pain management, about 12% report misuse, and a large number of these may find themselves addicted to opioid medications. Opioid addiction is an ongoing epidemic, costing many lives. Withdrawal is very difficult. This requires providers to consider alternative analgesic plans and minimize opiate use. Here we report the use of a dexamethasone-dexmedetomidine combination for a regional nerve block in an elderly woman chronically treated with opiate medications who had previously failed opiate weaning. Following her nerve block, she was able to completely wean off of opioids and continues having good pain control with an opioid-free regimen.
An out-of-plane sensing fluxgate magnetic field sensor with an assisted flux conductor
Authors: Hsieh Ping-Hsun , Chen Shih-Jui
Published: January 2021

An out-of-plane sensing fluxgate sensor based on the printing process and assembled with core and flux conductors is proposed. The assisted inverted V-shaped flux conductor is utilized to collect the out-of-plane magnetic flux and direct it in the in-plane direction. Through the transmitted magnetic flux, the planar construction of the coil and core achieves out-of-plane sensing. Under a sinusoidal excitation signal of frequency 50 kHz and a current of 400 mA, the presented sensor shows a sensitivity of 127.3 V/T within a linear range of 0 µT–80 µT and with nonlinearity below 5%.
Influence of magnetic nanoparticles on cells of Ehrlich ascites carcinoma
Authors: Stolyar S. V. , Kryukova O. V. , Yaroslavtsev R. N. , Bayukov O. A. , Knyazev Yu. V. , Gerasimova Yu. V. , Pyankov V. F. , Latyshev N. V. , Shestakov N. P.
Published: January 2021

The effect of magnetic nanoparticles coated with arabinogalactan on the viability of Ehrlich ascites carcinoma (EAC) cells was studied. The nanoparticles were studied by transmission electron microscopy, Mössbauer spectroscopy, IR spectroscopy, and ferromagnetic resonance. A correlation between the proportion of dead EAC cells in suspension and the intensity of the EPR signal of dinitrosyl iron complexes was found. This result may be due to the presence of NO molecules.
11 Effect of breed type on production of bovine embryos: Experience in Paraguay
Authors: Arreseigor C. , Arza-Spinzi F. , Sanchez P. , Berdugo J. A. , Konrad J. L. , Maldondo-Vargas P.
Published: January 2021

One of the parameters that has the most influence on invitro embryo production programs is the number of oocytes obtained in each follicular aspiration session (ovum pickup; OPU). A significant impact of the breed of the donor on this parameter has been reported. The objective of this work was to compare the parameters of an invitro embryo production program of cows of different breeds in Paraguay. A total of 4811 OPU sessions were performed between 2016 and 2019 in cows classified according to breed and type. Beef-type breeds: Nelore (Bos indicus): n=1569; Aberdeen Angus (Bos taurus): n=1276; and Brangus (Cross): n=182 OPU, and Gyr (Bos indicus): n=1086; dairy breeds: Holstein (Bos taurus): n=401, and Girolando (Cross): n=297. The oocytes were aspirated and transported to the same laboratory located in Asunción, Paraguay. The invitro embryo production protocol was similar in all types. Bull semen tested for IVF was used. The number of oocytes, percentage viability, and percentage embryo production were evaluated. Additionally, the mean and standard deviation of the variables were calculated to show the efficiency of the processes, according to the production aptitude of the donors (meat or milk) and the breed type (Bos indicus, Bos taurus, or crosses). Continuous data were analysed with ANOVA and Tukey’s post hoc comparisons. Categorical data were analysed using Chi-squared at a significance level of 0.05. In this work, the production aptitude had no significant effect over the studied variables. However, some significant differences were found considering the breed type of the oocyte donor cow, as shown in Table 1. When crosses with the pure breeds are compared with their crosses, we found that Brangus produced more pregnancies and a greater number of oocytes/OPU compared with Angus (P<0.05). When the same comparison was made between Girolando and Holstein, no significant differences were found. The results show that Bos indicus breeds and their crosses have a greater capacity to produce more oocytes and embryos and that Bos indicus and crossbreeds were more efficient in producing pregnancies (2-fold) per OPU session than Bos taurus breeds. Additionally, crossing with meat indicus breeds generates better quality embryos and increases efficiency in the system of embryo production.

Table 1.
Comparison of embryo production parameters

Item
Breed type

Bos indicus
Cross
Bos taurus

Oocytes/OPU (mean±SD)
29.8±2.7a
26.3±7.8a
14.6±1.4b

Viable oocytes, %
64.7±3a
64.6±3.4a
60.1±3.1a

Embryo produced/OPU, %
35.2±4.7a
32.8±9.4a
26.2±4a

Embryo/OPU
6.9±1.7a
5.4±1.7a
2.3±0.4b

Pregnancy rate, %
29.6±5.5a
33.1±6.3a
25.3±5a

Pregnancies/OPU
2.1±0.9a
1.9±1a
0.6±0.2b

a,bValues within a row different letters differ (P<0.05).
111 Use of gonadotrophin-releasing hormone (GnRH) or equine and human chorionic gonadotrophins for oestrus synchronization and their influence on embryo viability and progesterone levels on day 16 and 30 of goats receiving GnRH 5 days after intrauterine insemination or natural service
Authors: Encinas F. , Rojas M. , Dawson L. , Loetz E.
Published: January 2021

Gonadotrophin-releasing hormone (GnRH) or equine and human chorionic gonadotrophins (eCG and hCG) were evaluated for oestrus/ovulation synchronization (E/OS), as well as the influence of GnRH 5 days post-breeding (dpb) on embryo viability (EV), and progesterone (P4) levels on Day 16 and 30 after laparoscopic AI (LAI) or natural service (NS). Fifty-four lactating/non-lactating Alpine breed goats (average of 3.82±1.2s.d. years of age) of mixed parity were E/OS during the early transitional breeding phase using 12±1 day of 300mg of P4 and 2mL of prostaglandin F2α analogue given at P4 removal. The experiment included a sub-group from a larger study in which a completely randomised design was used. The germane data were arranged as a 2×2×2 factorial. This study focused on goats receiving 120IU of eCG and 60IU of hCG (n=40), or GnRH analogue (n=14) 24h after P4 removal. At 5 dpb, 25 goats received 1mL (IM) of GnRH and the control (n=29) received 1mL of physiologic saline. Goats were time-bred 48h after P4 withdrawal by LAI (n=33) or NS (n=21). Pregnancy was diagnosed at 18 to 24, 30, and 40 dpb by non-return to oestrus, pregnancy-specific protein B, and ultrasound, respectively. EV was evaluated as the difference between pregnancy diagnosis results. Blood serum P4 was evaluated at 5, 16, and 30 dpb. A logistic regression model was used for statistical analysis. Pregnancy rate (PR) for LAI or NS, at 18–24, 30, and 40 days was 73 vs. 76%, 67 vs. 62%, and 64 vs. 67%, respectively (P>0.72). In contrast, when GnRH was used for E/OS, the 5 dpb GnRH influenced EV at 30 days (95 vs. 81%; P=0.06) but not at 40 days (89 vs. 86%; P>0.35), compared with placebo. Similarly, with the exception of PR at 40 days (43 vs. 72%; P=0.05), for the GnRH and eCG/hCG E/OS groups, respectively, PR was not affected (P>0.12) by either E/OS or GnRH 5 dpb or their interaction (P>0.35) at any pregnancy diagnosis (i.e. 18–24, 30, or 40 dpb). Likewise, levels of P4 at 5, 16, and 30 dpb did not affect PR at 18–24, 30, and 40 dpb (P>0.92, 0.71, and 0.11). As shown in Table 1, the level of P4 was not influenced for goats receiving GnRH or placebo at 5, 16, or 30 dpb. The baseline mean P4 blood serum level for goats receiving GnRH 5 dpb differed at 16 but not at 30 dpb (P<0.001).

Table 1
Blood serum progesterone (P4, ng mL−1) in response to gonadotrophin-releasing hormone (GnRH) or placebo given 5 days post-breeding

Sampling day
GnRH
Placebo
P >1

Mean
±SE
Mean
±SE

5 (baseline)
6.2a
0.83
5.7a
0.72
0.66

16
11.7b
1.11
11.0b
1.05
0.65

30
6.2a
0.89
7.6c
0.84
0.26

a–cMean values with different superscripts within a column signify statistical difference for GnRH (P<0.001) and placebo (P<0.02).
1Probability for mean differences in the same row.
142 Nulliparity alters gene expression in inner cell mass and trophoblast of equine blastocysts in old mares
Authors: Derisoud E. , Jouneau L. , Archilla C. , Daniel N. , Jaszczyszyn Y. , Gourtay C. , Margat A. , Dahirel M. , Peynot N. , Briot L. , De Geoffroy F. , Duranthon V. , Chavatte-Palmer P.
Published: January 2021

An increased incidence in early embryo loss has been observed in aged mares. Moreover, the first foal born to a mare is lighter than her subsequent foals, with reported impaired placental function at term. Because trophoblast function may be affected from the embryo stage, the aim of this project was to determine the effect of parity in aged mares on gene expression in Day-8.5 embryos. Middle-aged (13.5±2.2 years) nulliparous (never foaled) (ON) or multiparous (1.8±1.6 foals) (OM) Saddlebred, non-nursing mares were inseminated with the semen of one unique stallion. At 8 days post-ovulation (10 days post-hCG), embryos were recovered by uterine flushing and bisected to obtain samples of pure (trophectoderm, TE) or inner cell mass enriched (ICM) trophoblast. Paired end, non-oriented RNA sequencing was performed with Illumina (NextSEqn 500) on 5 and 6 TE and ICM collected from ON and OM, respectively. Differential expression was analysed with DESEqn 2. Embryo size was included in the model and a P<0.05 cutoff was used after false discovery rate correction. Gene set enrichment analysis (GSEA) was performed using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) databases. Out of the 13 007 and 12 706 genes expressed in ICM and TE, respectively, only 8 in ICM and 6 in TE were differentially expressed, with 2 genes in common. Nevertheless, 19 gene sets were enriched and 6 depleted in the ICM of ON, whereas 2 gene sets were enriched and 8 depleted in the TE of ON compared with OM. Gene sets involved in ribosomal activity and structure, proteasome, integral component of plasma membrane, and immune response were enriched in ICM from ON embryos, and gene sets linked to sphingolipid metabolism, nucleosome, and constituents of the extracellular matrix (ECM) were depleted. In TE from ON mares, enriched gene sets were involved with ribosomes and depleted gene sets were linked to extracellular matrix, focal adhesion, myosin complex, and sequence-specific DNA binding. Overall, 1 enriched (linked to extracellular matrix) and 1 depleted gene set (involved in ribosomal structure) were common to ICM and TE. Thus, embryos from aged nulliparous mares seem to have higher protein turnover and higher immune response compared with those of OM, whereas the depletion of gene sets associated with extracellular matrix and membrane may indicate differences in cellular organisation into lineages. More work is ongoing to study effects on subsequent development.
18 Histomorphometric comparison of right and left oviduct structure from alpaca (Vicugna pacos)
Authors: Sánchez K. , Dipaz D. , Rodriguez M. , Mellisho E.
Published: January 2021

One of the phenomena that occurs during pregnancy in camelids is that nearly all fetuses occupy the left uterine horn, even though both ovaries ovulate with equal frequency. However, there are no reports on morphometric differences between the alpaca left and right oviducts, which could indicate an effect on gamete transport. The present study was carried out to measure and compare inner and outer measurements of the left and right oviduct regions from alpaca. One hundred twenty transverse sections (5µm) of oviducts were studied from 5 adult females, all with dominant ovarian follicle collected in the slaughterhouse. The oviducts were divided into 5 regions: tubal uterus junction (UTJ), isthmus (Is), ampullary isthmus junction (AIJ), ampulla (A), and infundibulum (In), processed and stained with haematoxylin and eosin. Stained slides were studied under the trinocular microscope at 40× magnification, and the images obtained under the microscope were transferred to a computer. The luminal area, number of primary folds, height of primary folds, height of epithelium, thickness of the muscular layer, inner diameter of circular muscular layer, and thickness of the serosa layer were measured using the Motic Images Plus 2.0 software. These measurements for each 5 regions were compared between left and right oviducts using ANOVA test and the association of the parameters with Pearson correlation analysis using SPSS vs.22 software (IBM Corp.). Ampulla luminal area (399 553.5±152 551.2µm2), thickness of the muscular layer of the region UTJ (280.9±55.0µm), thickness of the muscular layer of the Isthmus region (175.4±28.9µm), and inner diameter of circular muscular layer of the UTJ region (1003.4±102.9µm) of the right side were larger (P<0.05) than those on left side. On the left side, we observed the opposite (P<0.05) in the AIJ region, with a greater height of epithelium (9.9±2.6µm) and thickness of the serosa layer (106.5±52.7µm) compared with the right side. Also, we observed a negative correlation between the thickness of the muscular layer and number of primary folds (r=−0.63; P<0.001) and between thickness of the muscular layer and height of primary folds (r=−0.18; P=0.007). In conclusion, the regions of the right and left oviductal structure present some different morphometrics that could influence the transport of gametes and embryos in South American camelids. It is necessary to carry out secretomic and gene expression studies at the oviduct level, and to expand the number of replicates to correlate the ovary with the presence of a dominant follicle and the reported measurements.
84 Characterization of agouti-signalling protein expression within the bovine ovary and early embryo
Authors: Baldwin H. , Zhang M. , Current J. , Yao J.
Published: January 2021

Factors present in the oocyte and surrounding follicular cells aid in the attainment of oocyte competence. Agouti-signalling protein (ASIP) is a known regulator of melanocyte function through binding to melanocortin receptors including MC1R and MC4R. Additionally, ASIP has been classified as an adipokine due to a link with insulin resistance and obesity in humans. In mice, expression is limited to hair follicles where ASIP regulates hair pigmentation. In cattle, however, ASIP mRNA has been detected in a variety of tissues, including adipose, skin, heart, testis, and the ovary. Despite ovarian expression, the role of ASIP in reproduction remains undetermined. Bovine ASIP is a secreted protein consisting of 133 amino acids. The aim of this experiment was to provide a detailed description of the ASIP expression profile within the bovine ovary and during early embryonic development. Reverse transcription PCR (RT-PCR) was conducted to analyse ASIP, MC1R, and MC4R mRNA expression. Samples examined included fetal ovaries from gestational day 90 to 250, adult ovary, fetal testis, adult testis, and 12 somatic tissues including adrenal, cerebral cortex, gut, heart, intestine, kidney, liver, lung, muscle, pituitary, stomach, and thymus. Amplification of ribosomal protein L19 (RPL19) served as a positive control for all samples. Expression of ASIP was detected in the fetal testis, 9 somatic tissues, and the fetal and adult ovary. In the fetal ovary, ASIP was detected as early as 90 days of gestation and continued throughout gestation. Expression of the ASIP receptors, MC1R and MC4R, were detected exclusively in the fetal ovary. To further characterise ASIP expression, quantitative real-time PCR (RT-qPCR) was utilised to examine samples including germinal vesicle and MII oocytes (pool of 10 oocytes), invitro-produced embryos ranging from the 2-cell to blastocyst stages (pool of 10 embryos), and cumulus and granulosa cells collected from a pool from 5 cumulus–oocyte complexes (COCs) and follicles, respectively. Theca cells from a single follicle were analysed. Samples with cycle threshold values below 35 were considered to express the gene of interest. Of the follicular cells examined, ASIP expression was present in theca, granulosa, and cumulus cells. ASIP expression was detected in both GV and MII oocytes. Early embryonic expression of ASIP was detected in the 2-cell embryo and continued to the blastocyst stage of development. In conclusion, ASIP is present in the bovine adult and fetal ovary, follicular cells including cumulus, granulosa, and theca cells, GV and MII oocytes, and invitro-produced embryos from the 2-cell to blastocyst stages. Future research will focus on identifying the function of ovarian and early embryonic ASIP in cattle.
Media vs. candidates and minorities vs. majorities
Authors: Trifiro Briana , Zhang Yiyan
Published: January 2021

Despite an abundance of research dedicated to the first level agenda setting process in political elections, there is a
considerable gap within the literature regarding how the amount of media coverage granted to minority candidates – people of color and
women – influence their salience in public opinion. The current study seeks to address this gap by analyzing the effects of online coverage
of minority candidates and their subsequent performance in national polling data from June 1, 2019 to November 20, 2019. The present study
utilizes a time-series analysis to compare three information formats: Twitter accounts of major media organizations, online web mentions of
candidates from these organizations, and the candidates’ own Twitter presence. The presented findings illustrate important relationships –
specifically, where candidates of color were able to set their own agenda through their Twitter accounts as opposed to coverage that they
received from the media.
Modeling and Characterization of Aisi S-7 Steel Using the Johnson Cook Model – an Explicit Analysis
Authors: Abhinav  , Ribeiro Rahul , Jain Ranjana , Arunkumar D
Published: January 2021

: A two dimensional, uniformly distributed grains model has been developed for AISI S-7 grade Steel and the orthogonal machining process, in the pursuit of determining the various effects of temperature rise, residual stresses, chip morphology, and strain hardening. A Johnson-Cook material model, along with a numerical, technique was used to simulate the machining process using ANSYS 15 academic license. The machining has been carried out at different velocities: 60, 70, and 80 ms-1 and with depths of cut of 2, 3, and 5 mm. Results revealed that the accumulation of tandem grains offers a maximum resistance ahead of the tool-chip interface due to the strain hardening effect, during the metal removal process. This effect leads to a maximum rise in temperature up to 912.59 °C, which has been observed in the secondary shear zone. Serrated chip flow was observed mainly at a low speed of 60 ms-1. The Strain hardening effect was more substantial at 60 ms-1 and 5 mm depth of cut compared to any other machining parameters. A great deal of discussion has been made on the above material machining process that may serve as a useful resource to the tool designer and manufacturing scientist.
Numerical study on fly ash–Cu hybrid nanofluid heat transfer characteristics
Authors: Kanti Praveen , Sharma K.V. , Ramachandra C.G. , Gurumurthy M , Raghundana Raghava B M
Published: January 2021

The current numerical study is aimed to examine the forced convection heat transfer of fly ash-Copper (80:20% by volume) water-based hybrid nanofluids flowing in a horizontal circular copper tube under a constant heat flux of 7962W/m2 using STAR CCM+ software. The volume concentrations of 0.5% and 1% are considered for the analysis within the Reynolds number range of 6900-26500. The findings show that the heat transfer coefficient and the Nusselt number of hybrid nanofluid at a concentration of 1 vol.% are increased by about 66.0% and 36.67% compared to that of water.
Date Palm fibre reinforced composite by multiple resin to enhance the properties of a composite - A Review
Authors: Rajan Rajthilak Krishnan , Ramesh S , Lokesh G.N. , Boppana Satish Babu
Published: January 2021

Numerous applications of the composites have been increased in this Era. The Research on polymer matrix composites using Natural fibre is wide. Natural fibres are one of the most abundant resources that exist in nature. In this paper, Date palm fibre is discussed for making of composites as it is one of the most available natural fibres in the world. It is the basic agricultural crop, especially in Middle East countries. Specific strength is the Parameter which makes date palm fibre superior compared to other fibres. To improve proper adhesion, the natural fibres are to be chemically treated to attain the better properties when compared to the untreated fibres. However, resins play a vital role in preparing a Composite. There are multiple resins used as matrices to make a composite. Hence, this paper is to analyse the date palm fibre-based polymer matrix composites for different resins for their Mechanical properties and Thermal properties. The Properties of various Natural fibres are also discussed in this paper.
Design of Parallel Sorting System Using Discrete-Time Neural Circuit Model
Authors: Tymoshchuk Pavlo V
Published: January 2021

A parallel sorting system based on discrete-time K-Winners-Take-All (KWTA) neural circuit (NC) model is designed. The system is described by a set of difference equations and by step functions. The KWTA NC model of discrete-time is given by difference equation and by step functions. Corresponding functional block-diagrams of the system are presented. The upper limit on the number of iterations required to achieve a convergence of the sorting process to the steady state is defined. The system does not need a knowledge of range of input data change. In order to use the system, the minimal difference between the inputs should be known. The system is suitable for processing unknown inputs of finite values located in arbitrary unknown finite range. The system is characterized by arbitrary finite resolution of inputs, high speed, moderate computational complexity and complexity of software implementation. The results of computer simulations illustrating efficiency of the system are provided.
Development and Modeling of Remote Laboratory Works for Engineering Education
Authors: Sus B B , Zagorodnyuk S P , Bauzha O S , Kozinetz A
Published: January 2021

The basic principles of finite-state machine synthesis and simulation on Proteus CAD and VHDL are discussed. The main steps of designing an electronic circuit of the control and operating finite-state machines that perform the calculation of a given algebraic expression were described. The main steps of consistent performance of a complex task for the development of cross-cutting knowledge and skills, which must be performed by the student in the framework of the normative discipline ware analysed in detail. It is shown that the developed cycle of laboratory works can be successfully implemented in various training courses.
Design Model for Determination of the Strength Fiber-Reinforced Concrete
Authors: Sylovanyuk Viktor , Lisnichuk Riy , Kolesnyk Kostiantyn , Panchak Roman
Published: January 2021

The model of fiber-reinforced concrete for determination of strength under tensile was developed. Formula for assessment of the strength of fiber-reinforced concrete, which takes into account micro-cracks and pores in the materials structure and the presence of reinforcing fibers, was established on the basis of the model. Experimental study for establishment of strength of cement reinforced with fiber of different nature and different volume content were conducted to confirm the received formula. It was shown that theoretical prediction of fiber-reinforced concrete strength correlates with experimental data.
Issues with Belt Guidance and Device Controls in the Automated Conveyor and Drive Belt Perforation Process
Authors: Wojtkowiak D , Talaśka K , Domek G , Wilczyński D , Górecki J
Published: January 2021

The perforation process for multi-layer composite polymer belts presents numerous challenges due to the varied mechanical characteristics and geometrical parameters of the entire range of belts used in the industry. Many problems can be minimized or eliminated with correct development of construction features of the machines for high precision mechanical belt perforation. Regardless of the construction solutions employed in the devices, a major factor influencing the quality of the final product as well as machine reliability is the method of controlling their operation as well as the correct guidance of the belt throughout the entire flow of material in the manufacturing process. The present work provides an analysis of the assemblies ensuring correct belt guidance and presents the causes and effects of incorrect development of these systems. Furthermore, it touches upon the aspects involving the control solutions for such equipment involving the definition of actuators and controllers, the selection of sensors and methods of measuring linear displacement of the belt and perforating head position together with the control algorithms for carrying out different patterns of perforation.
Does Reproducibility Drive Clinical Accuracy?
Authors: Emancipator Kenneth
Published: January 2021

Objectives

To develop a stochastic model relating measurement uncertainty, including reproducibility, to clinical accuracy, as demonstrated by the receiver operating characteristic curve.

Methods

A model is developed based on the symmetric case of the well-known binormal distribution. The overall distribution is partitioned further into analytical and biological components based on assumptions derived from the Cotlove criterion. Explicit mathematical solutions are derived and further verified by Monte Carlo analyses.

Results

The model demonstrates that tests with analytical error that conforms to the classic Cotlove criterion can achieve receiver operating characteristic curves with areas under the curve of 0.68 to 0.76 and Youden indices of 0.26 to 0.38 but have overall agreement for duplicate measurements of only 80% to 82%. Furthermore, the analytically accurate agreement is only 75% to 78%, and the clinically accurate agreement is only 50% to 60%.

Conclusions

The model suggests that assays may have reasonable clinical accuracy despite having reproducibility of less than 85%. Imperfect assays can substantially improve medical decision-making. The findings must be interpreted with caution given the binormal assumptions, but such assumptions are often useful as a first approximation. Practicing pathologists should feel comfortable performing semiquantitative assays shown to have a strong biological association with clinical outcome.
V-pipe: a computational pipeline for assessing viral genetic diversity from high-throughput data
Authors: Posada-Céspedes Susana , Seifert David , Topolsky Ivan , Jablonski Kim Philipp , Metzner Karin J , Beerenwinkel Niko
Published: January 2021

Motivation

High-throughput sequencing technologies are used increasingly not only in viral genomics research but also in clinical surveillance and diagnostics. These technologies facilitate the assessment of the genetic diversity in intra-host virus populations, which affects transmission, virulence and pathogenesis of viral infections. However, there are two major challenges in analysing viral diversity. First, amplification and sequencing errors confound the identification of true biological variants, and second, the large data volumes represent computational limitations.

Results

To support viral high-throughput sequencing studies, we developed V-pipe, a bioinformatics pipeline combining various state-of-the-art statistical models and computational tools for automated end-to-end analyses of raw sequencing reads. V-pipe supports quality control, read mapping and alignment, low-frequency mutation calling, and inference of viral haplotypes. For generating high-quality read alignments, we developed a novel method, called ngshmmalign, based on profile hidden Markov models and tailored to small and highly diverse viral genomes. V-pipe also includes benchmarking functionality providing a standardized environment for comparative evaluations of different pipeline configurations. We demonstrate this capability by assessing the impact of three different read aligners (Bowtie 2, BWA MEM, ngshmmalign) and two different variant callers (LoFreq, ShoRAH) on the performance of calling single-nucleotide variants in intra-host virus populations. V-pipe supports various pipeline configurations and is implemented in a modular fashion to facilitate adaptations to the continuously changing technology landscape.

Availabilityand implementation

V-pipe is freely available at https://github.com/cbg-ethz/V-pipe.

Supplementary information

Supplementary data are available at Bioinformatics online.
Second-site revertants of Escherichia coli trp repressor mutants.
Authors: Klig L S , Oxender D L , Yanofsky C
Published: January 2021

Second-site reversion studies were performed with five missense mutants with defects in the trp repressor of Escherichia coli. These mutants were altered throughout the gene. The same unidirectional mutagen used in the isolation of these mutants, hydroxylamine, was used in reversion studies, to increase the likelihood that the revertants obtained would have second-site changes. Most of the second-site revertants were found to have the same amino acid substitutions detected previously as superrepressor changes. These second-site revertant repressors were more active in vivo than their parental mutant repressors, in the presence or absence of exogenous tryptophan. Apparently superrepressor changes at many locations in this protein can act globally to increase the activity of mutant repressors.
Structure and evolution of the Adh genes of Drosophila mojavensis.
Authors: Atkinson P W , Mills L E , Starmer W T , Sullivan D T
Published: January 2021

The nucleotide sequence of the Adh region of Drosophila mojavensis has been completed and the region found to contain a pseudogene, Adh-2 and Adh-1 arranged in that order. Comparison of the sequence divergence of these genes to one another and to the Adh region of Drosophila mulleri and other species has allowed the development of a model for the evolution of the duplication of the Adh genes. There have been two major events. An initial duplication of an Adh gene whose dual promoter structure was similar to Drosophila melanogaster, resulted in a species with two Adh genes, one of which may have had only a proximal promoter. A second duplication of this gene generated an Adh region containing three genes. It is proposed that one of these is the ancestral gene having dual promoters, while the other two possess only proximal promoters. Subsequent events have resulted in both a change in the regulation of Adh-2 such that it is expressed as if it had a "distal" type promoter and the mutational inactivation of the most upstream gene resulting in the creation of a pseudogene. The sequence of the D. mojavensis Adh region has also revealed the presence of an element which is composed of juxtaposed inverted imperfectly repeated elements. There is a surprising and not fully explainable strong similarity of the nucleotide sequence of the 5' flanking region of the pseudogene in D. mojavensis and D. mulleri.
The alcohol dehydrogenase polymorphism in Drosophila melanogaster: fitness measurements and predictions under conditions with no alcohol stress.
Authors: Bijlsma-Meeles E , Bijlsma R
Published: January 2021

The relative fitnesses of the different Adh genotypes under normal laboratory conditions and in the absence of alcohol stress were estimated in Drosophila melanogaster according to Prout's method. The larval component (viability) did not reveal fitness differences between the genotypes but for the adult component significant differences were observed. The female adult component (fecundity) showed an overdominant pattern: both homozygous genotypes showed a relative fitness significantly lower than the heterozygous genotype. For the male adult component (virility) also differences were observed. The homozygous SS genotype showed a lower relative fitness than the other two genotypes. Predictions for gene frequency changes based on the estimated fitness values do show a reasonably good correspondence with frequency changes actually observed in a number of experimental cage populations and indicate a globally stable equilibrium around a frequency of the F allele of 0.40-0.70. The relevance of these fitness estimates, obtained under conditions with no alcohol stress, for the explanation of the Adh polymorphisms observed in nature is discussed.
Recombination within a subclass of restriction fragment length polymorphisms may help link classical and molecular genetics.
Authors: Meagher R B , McLean M D , Arnold J
Published: January 2021

Restriction fragment length polymorphisms (RFLPs) are being used to construct complete linkage maps for many eukaryotic genomes. These RFLP maps can be used to predict the inheritance of important phenotypic loci and will assist in the molecular cloning of linked gene(s) which affect phenotypes of scientific, medical and agronomic importance. However, genetic linkage implies very little about the actual physical distances between loci. An assay is described which uses genetic recombinants to measure physical distance from a DNA probe to linked phenotypic loci. We have defined the subset of all RFLPs which have polymorphic restriction sites at both ends as class II RFLPs. The frequency of class II RFLPs is computed as a function of sequence divergence and total RFLP frequency for highly divergent genomes. Useful frequencies exist between organisms which differ by more than 7% in DNA sequence. Recombination within class II RFLPs will produce fragments of novel sizes which can be assayed by pulsed field electrophoresis to estimate physical distance in kilobase pairs between linked RFLP and phenotypic loci. This proposed assay should have particular applications to crop plants where highly divergent and polymorphic species are often genetically compatible and thus, where class II RFLPs will be most frequent.
King's formula for the mutation load with epistasis.
Authors: Kondrashov A S , Crow J F
Published: January 2021

A formula by J. L. King gives the equilibrium mutation load as L = 2 sigma ui(1 - qi)/z - x) in which ui is the mutation rate to deleterious alleles at the ith locus, qi is the frequency of mutant alleles at this locus, x is the mean number of such mutant genes per individual before selection, z is the mean number in individuals eliminated by selection, and the summation is over all relevant loci. We show that this rule is inaccurate for intense selection and that a correct formula is L = 2 sigma ui(1 - qi) w/(z - x) = 2U w/(z - x) = 2U/(z - x + 2U) in which U is the mean number of new mutations per haploid genome in the population and w is the mean relative fitness before selection. If w/(z - x) less than 1/2, the mutation load is less than the Haldane value (U less than or equal to L less than or equal to 2U) and can be considerably less. In a diploid asexual population, however, with independent occurrence of mutations, L = 1 - e-2U regardless of the mode of selection.
Amplification of KP elements associated with the repression of hybrid dysgenesis in Drosophila melanogaster.
Authors: Jackson M S , Black D M , Dover G A
Published: January 2021

Mobile P elements in Drosophila melanogaster cause hybrid dysgenesis if their mobility is not repressed. One type of repression, termed P cytotype, is a complex interaction between chromosomes carrying P elements and cytoplasm and is transmitted through the cytoplasm only of females. Another type of repression is found in worldwide M' strains that contain approximately 30 copies per individual of one particular P element deletion-derivative termed the KP element. This repression is transmitted equally through both sexes. In the present study we show that biparentally transmitted repression increases in magnitude together with a rapid increase in KP copy-number in genotypes starting with one or a few KP elements and no other deletion-derivatives. Such correlated increases in repression and KP number per genome occur only in the presence of complete P elements, supporting the interpretation that they are probably a consequence of the selective advantage enjoyed by flies carrying the highest numbers of KP elements. Analysis of Q strains also reveals the presence of qualitative differences in the way the repression of dysgenesis is transmitted. In general, Q strains not containing KP elements have the P cytotype mode of repression, whereas Q strains with KP elements transmit repression through both sexes. This difference among Q strains further supports the existence of at least two types of repression of P-induced hybrid dysgenesis in natural populations of D. melanogaster.
A CRITICAL EXAMINATION OF THE USE OF THE JOLICOEUR-BRUNEL DIAGRAMS TO DEMONSTRATE SELECTION IN BIOLOGICAL POPULATIONS
Authors: Wool David
Published: January 2021

The use of the Jolicoeur-Brunel hexagonal diagrams to demonstrate selection in biological populations was tested in a computer-simulation study.—The results show convincingly that the probabilities associated with the six deviation patterns illustrated in the hexagonal diagrams are not equal, but depend on the sample size and in particular on the genetic composition of the sampled population. The diagrams thus cannot be used to demonstrate selection, but only to illustrate trends of deviation patterns, which may be real biologically.
AN INVESTIGATION OF THE COMPONENTS OF SEGREGATION-DISTORTER SYSTEMS IN DROSOPHILA MELANOGASTER
Authors: Miklos George L Gabor
Published: January 2021

The problems of the Segregation-Distorter system are approached and unified in terms of an orthodox quantitative genetic system. It is shown that the SD system involves positive and negative modifier genes of varying strengths, that there is no major Stabiliser gene, and that the Activator gene is not unique. It is further argued that the SD phenomenon is mainly male limited, with "female effects" being of small magnitude.
SELECTION IN FINITE POPULATIONS WITH MULTIPLE ALLELES. III. GENETIC DIVERGENCE WITH CENTRIPETAL SELECTION AND MUTATION
Authors: Latter B D H
Published: January 2021

Natural selection for an intermediate level of gene or enzyme activity has been shown to lead to a high frequency of heterotic polymorphisms in populations subject to mutation and random genetic drift. The model assumes a symmetrical spectrum of mutational variation, with the majority of variants having only minor effects on the probability of survival. Each mutational event produces a variant which is novel to the population. Allelic effects are assumed to be additive on the scale of enzyme activity, heterosis arising whenever a heterozygote has a mean level of activity closer to optimal than that of other genotypes in the population.—A new measure of genetic divergence between populations is proposed, which is readily interpreted genetically, and increases approximately linearly with time under centripetal selection, drift and mutation. The parameter is closely related to the rate of accumulation of mutational changes in a cistron over an evolutionary time span.—A survey of published data concerning polymorphic loci in man and Drosophila suggests than an alternative model, based on the superiority of hybrid molecules, is not of general importance. Thirteen loci giving rise to hybrid zones on electrophoresis have a mean heterozygote frequency of 0.22 ±.06, compared with a value of 0.23 ±.04 for 16 loci classified as producing no hybrid enzyme.
DOSAGE OF THE MATERNAL EFFECT GENE ASSOCIATED WITH THE TUMOROUS-HEAD ABNORMALITY IN DROSOPHILA MELANOGASTER
Authors: Siervogel R M
Published: January 2021

The penetrance of tuh-3 observed in the progeny of triploids with two doses of tuh-1 was not statistically different from that occurring in the progeny of their diploid sisters with two doses. A higher penetrance was observed in the progeny of triploids with three doses of tuh-1 than in the progeny of their diploid sisters with two doses. These observations suggest that the maternal effect responsible for increasing the penetrance of tuh-3, the gene causing the tumorous-head abnormality, is caused by a specific gene product of tuh-1, the maternal-effect allele. In addition there is probably a maternal-effect threshold, lying between amounts produced by one and two doses of tuh-1, below which no increased penetrance of tuh-3 is observed.
CIRCULAR DNA MOLECULES IN THE GENUS DROSOPHILA
Authors: Travaglini E C , Schultz J
Published: January 2021

The satellite DNA's from the embryos of five species of Drosophila (D. melanogaster, D. simulans, D. nasuta, D. virilis and D. hydei) have been analyzed for the presence of closed circular duplex DNA molecules, as determined by CsCl-EBr gradients. Circular DNA molecules were found in every species but D. melanogaster. Analyses of cell fractions from adult Drosophila and organ fractions from Drosophila larvae show that fractions containing mitochondria are highly enriched in these molecules.
MACRONUCLEAR GENETICS OF TETRAHYMENA I. RANDOM DISTRIBUTION OF MACRONUCLEAR GENE COPIES IN T. PYRIFORMIS, SYNGEN 1
Authors: Orias Eduardo , Flacks Miriam
Published: January 2021

The objective of this study was to test the idea that the macronuclear (somatic) genetic information is randomly distributed at each cell division in Tetrahymena pyriformis, syngen 1. We took advantage of a quick and reliable test for the detection of stable vegetative segregants in clones heterozygous for ts2, a heat-sensitive mutation. Clones that originated from cells inferred to contain very few (1-3) copies of the ts2  + allele in their macronuclei were selected for pedigree analysis. Experimental results were compared with the results of a computer simulation of the experiment. Our results are fully consistent with the predictions of the Allen-Nanney-Schensted model concerning the replication and distribution of functional gene copies. This model proposes that the macronucleus contains many functional copies of a given gene that are duplicated once during the cell cycle and are randomly distributed to the two-daughter nuclei. Our work has provided a more sensitive test of the assumption of randomness than was previously available. Our evidence for complete randomness suggests that 45, the effective number of macronuclear gene copies previously inferred from the segregation rate, indeed represents the actual number of copies. This conclusion, coupled with previously available evidence that the macronucleus is approximately 45-ploid, suggests that the segregating genetic units in the macronucleus are in effect haploid. This appears to remove the need to postulate inter-allelic repression to account for the phenomenon of phenotypic assortment. Our results, as well as those of others, also are inconsistent with any simple form of the master-slave hypothesis of Allen and Gibson.
DIFFERENTIAL SENSITIVITIES AND THE TARGET OF HEAT-INDUCED RECOMBINATION AT THE BASE OF THE X CHROMOSOME OF DROSOPHILA MELANOGASTER
Authors: Lifschytz Eliezer
Published: January 2021

The effect of heat on two small adjacent segments at the base of the X chromosome was examined. Recombination in the two segments delimited by recessive lethals was measured after treatment with 30° and 34°.Both segments were sensitive at 30°, while only the proximal one responded to 34° treatment. When the same segments were studied in structural heterozygotes (for deletions) the relative increase in recombination was greater, suggesting that heat exerts its effect on the "pairing" rather than the "exchange" components of crossing over. The effect of c (3) G/+ on the same segments in both homozygous and heterozygous structurals was studied. The results indicate that this meiotic mutant mediates its effect on a step different than that affected by heat.