Epigenetics as an Explanation for Phenotypic Variation in Monozygotic Twins

The following is the introduction of this article: Researchers often use twins as natural samples to test hypotheses regarding the contribution of genetic factors to different phenotypes, especially diseases. The classical method is comparing traits in identical, or monozygotic (MZ) twins to those of dizygotic (DZ) twins. This method has had a significant impact on our current understanding of etiologic factors in many diseases which do not follow simple Mendelian law (i.e. complex diseases), including schizophrenia, bipolar disease, and major depression

Principal component analysis for studying the world security problem

This research is a continuation of the work [1], in which the list of ten most essential global threats to the future of mankind have been presented. The initial data on each threat are taken from the respectable international organizations data bases. Then, we defined the summarized impact of the examined ten global threats totality on different countries based on cluster analysis method with the purpose of selecting groups of the countries with “close” performances of summarized threats. By using the Minkovsky type metric the foresight of the future global conflicting has been executed. To facilitate the analysis and make it easier we use the method of Principal Component Analysis (PCA) which allows reduce variables with many properties to several hidden factors. The analysis shows that currently the most considerable threats for most countries are the reduction of energy security, worsening of balance between bio capacity and human demands and the incomes inequality between people and countries.Проведено дослідження національної безпеки різних країн світу з використанням метода головних компонент (Principal Component Analysis) у просторі десяти глобальних загроз. За допомогою обчислення коефіцієнтів кореляції визначено характер залежності між головними чинниками і вихідними загрозами. Визначено три найбільш істотні загрози, які впливають на національну безпеку більшості країн світу: державна нестабільність, дефіцит енергетичних ресурсів і нерівність доходів (Gini Index). Виконано графічну інтерпретацію глобальних загроз і визначено міри залежності між їх основними групами.Проведено исследование национальной безопасности различных стран мира с использованием метода главных компонент (Principal Component Analysis) в пространстве десяти глобальных угроз. С помощью вычисления коэффициентов корреляции определен характер зависимости между главными факторами и исходными угрозами. Проведена кластеризация стран по уровню глобальных угроз. Определены три наиболее существенные угрозы, влияющие на национальную безопасность большинства стран мира: государственная нестабильность, дефицит энергетических ресурсов и неравенство доходов (Gini Index). Выполнена графическая интерпретация глобальных угроз в пространстве трех главных компонент. Проведено исследование факторной структуры угроз и определены степени зависимости между их основными группами

Дослідження проблем світової безпеки за допомогою аналізу головних компонент

Проведено дослідження національної безпеки різних країн світу з використанням метода головних компонент (Principal Component Analysis) у просторі десяти глобальних загроз. За допомогою обчислення коефіцієнтів кореляції визначено характер залежності між головними чинниками і вихідними загрозами. Визначено три найбільш істотні загрози, які впливають на національну безпеку більшості країн світу: державна нестабільність, дефіцит енергетичних ресурсів і нерівність доходів (Gini Index). Виконано графічну інтерпретацію глобальних загроз і визначено міри залежності між їх основними групами.This research is a continuation of the work [1], in which the list of ten most essential global threats to the future of mankind have been presented. The initial data on each threat are taken from the respectable international organizations data bases. Then, we defined the summarized impact of the examined ten global threats totality on different countries based on cluster analysis method with the purpose of selecting groups of the countries with “close” performances of summarized threats. By using the Minkovsky type metric the foresight of the future global conflicting has been executed. To facilitate the analysis and make it easier we use the method of Principal Component Analysis (PCA) which allows reduce variables with many properties to several hidden factors. The analysis shows that currently the most considerable threats for most countries are the reduction of energy security, worsening of balance between bio capacity and human demands and the incomes inequality between people and countries.Проведено исследование национальной безопасности различных стран мира с использованием метода главных компонент (Principal Component Analysis) в пространстве десяти глобальных угроз. С помощью вычисления коэффициентов корреляции определен характер зависимости между главными факторами и исходными угрозами. Проведена кластеризация стран по уровню глобальных угроз. Определены три наиболее существенные угрозы, влияющие на национальную безопасность большинства стран мира: государственная нестабильность, дефицит энергетических ресурсов и неравенство доходов (Gini Index). Выполнена графическая интерпретация глобальных угроз в пространстве трех главных компонент. Проведено исследование факторной структуры угроз и определены степени зависимости между их основными группами

Tailoring the physicochemical and shape memory properties of the biodegradable polymer poly(glycerol dodecanoate) via curing conditions

A major challenge in the repair and regeneration of soft tissue damage occurring as a result of aging, injury, or disease is recapitulating the biomechanical properties of the native tissue. Ideally, a candidate biomaterial for soft tissue engineering applications should be biocompatible, nonlinearly elastic to match soft tissue mechanical behavior, biodegradable to enable tissue remodeling, and tailorable to achieve a range of nonlinear elastic mechanical properties to match specific soft tissues. In addition, for cardiac and other applications, the biomaterial should have shape memory characteristics to facilitate minimally invasive and/or catheter‐based delivery. Poly(glycerol dodecanoate) (PGD) is a shape memory material that has nonlinear elastic properties at body temperature and elastic‐plastic behavior at room temperature. In this study, we investigated the effects of curing conditions on the nonlinear elastic, shape memory, and biocompatibility properties of PGD. Increased curing and crosslinking resulted in an increase in both the initial stiffness and the nonlinear strain stiffening behavior of PGD. After shape fixation at 60% strain, 100% shape recovery was achieved within 1 min at body temperature for all conditions tested. Polymer curing had no adverse effects on the cellular biocompatibility or non‐hemolytic characteristics of PGD, indicating the potential suitability of these formulations for blood‐contacting device applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1618–1623, 2017.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136707/1/jbma35973_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136707/2/jbma35973.pd

Ресурсы баз данных информационных агентств для журналистов и аналитиков. (Аналитическая характеристика)

Using databases simplifies significantly the preparation of journalistic and analytical materials and complements online information search and verification practice. Introducing databases into everyday work of the mass-media results in the rise of the “data-driven journalism”.The authors analyze in brief the most popular foreign and Russian databases being maintained by news agencies (Bloomberg, Dow Jones Risk and Compliance, Interfax, ITAR-TASS) and by other information services (LexisNexis, Integrum, Kartoteka, Factiva, Dun & Bradstreet). Their history is discussed; they are defined by types and classified according to their content and access method (open/closed). In several cases, the database management system specifications are provided. Scenarios for use are given for journalists and analysts, for the latter the practical use is exemplified.Based on the classification they are suggesting, the authors compares the pros and drawbacks in using databases by news agencies (closed information systems) and Internet-based information retrieval systems (open systems) in journalism and analytics.Проанализированы наиболее известные зарубежные и российские базы данных информационных агентств (Bloomberg, Dow Jones Risk and Compliance, «Интерфакс», ИТАР-ТАСС) и другие справочные информационные сервисы (LexisNexis, «Интегрум», «Картотека», Factiva, Dun & Bradstreet). Представлена краткая история их появления. Системы типированы по основным признакам и классифицированы с точки зрения их контента и способов доступа (открытые/закрытые). В некоторых случаях дано техническое описание СУБД. Приведены сценарии их возможного применения в работе журналиста и аналитика. На примере последнего показано их использование в практической работе.На основе предложенной классификации проведён сравнительный анализ преимуществ и недостатков БД информационных агентств (закрытые информационные системы) и информационно-поисковых систем интернета (открытые информационные системы) в журналистской и аналитической деятельности

Rapid Prototyping of Flexible Structures for Tissue Engineered Ear Reconstruction

The tissue engineered ear has been an iconic symbol of the field since 1991, when the report of an engineered ear in a mouse model was first published A tissue engineered ear has an inherent advantage over conventional approaches because the structure is derived from the patient's own cartilage. In this approach, autologous auricular chondrocytes are harvested from the patient and grown within an ear-shaped scaffold. However, as the scaffold degrades or remodels, the ear-shaped structure undergoes significant distortion, resulting in a skewed ear shape that is smaller and often unrecognizable In order to maintain the desired ear geometry, a composite scaffold concept was developed Methods Several functional requirements for the manufacturing process were identified. First, the wire framework must be created with arbitrary three dimensional (3D) control, and with a diameter significantly smaller than the thickness of normal ear cartilage, which is about 2 mm. The bending stiffness must be sufficiently high so that shape is maintained during neocartilage maturation and sufficiently low such that flexibility of the overall structure is not impaired. The material must be approved for clinical use, and must not cause an inflammatory reaction. Finally, the manufacturing process must be capable of producing single, custom parts without significant cost burden. Plastic surgeons identified titanium and stainless steel as preferred materials due to their long history of success in medical implants Three manufacturing processes were identified that are capable of producing arbitrary shapes with the listed metals: wire bending, direct metal laser sintering (DMLS) Results Ear frameworks produced using DMLS and EBM technology are shown in Interpretation Ear frameworks produced using DMLS and EBM technology are shown i

Biomimetic poly(glycerol sebacate)/poly(L-lactic acid) blend scaffolds for adipose tissue engineering

Large three-dimensional poly(glycerol sebacate) (PGS)/poly(l-lactic acid) (PLLA) scaffolds with similar bulk mechanical properties to native low and high stress adapted adipose tissue were fabricated via a freeze-drying and a subsequent curing process. PGS/PLLA scaffolds containing 73 vol.% PGS were prepared using two different organic solvents, resulting in highly interconnected open-pore structures with porosities and pore sizes in the range of 91–92% and 109–141 μm, respectively. Scanning electron microscopic analysis indicated that the scaffolds featured different microstructure characteristics, depending on the organic solvent in use. The PGS/PLLA scaffolds had a tensile Young’s modulus of 0.030 MPa, tensile strength of 0.007 MPa, elongation at the maximum stress of 25% and full shape recovery capability upon release of the compressive load. In vitro degradation tests presented mass losses of 11–16% and 54–55% without and with the presence of lipase enzyme in 31 days, respectively. In vitro cell tests exhibited clear evidence that the PGS/PLLA scaffolds prepared with 1,4-dioxane as the solvent are suitable for culture of adipose derived stem cells. Compared to pristine PLLA scaffolds prepared with the same procedure, these scaffolds provided favourable porous microstructures, good hydrophilic characteristics, and appropriate mechanical properties for soft tissue applications, as well as enhanced scaffold cell penetration and tissue in-growth characteristics. This work demonstrates that the PGS/PLLA scaffolds have potential for applications in adipose tissue engineering

Thermoresponsive, stretchable, biodegradable and biocompatible poly(glycerol sebacate)-based polyurethane hydrogels

Thermoresponsive, stretchable, biodegradable and biocompatible polyester-based polyurethane (PEU) hydrogels, based on poly(glycerol sebacate) pre-polymer and poly(ethylene glycol)s of different molecular masses were synthesized by a facile solvent-based two-step method. The chemical and physical characteristics of the PEU hydrogels are tunable, enabling the design of various negatively thermosensitive, mechanically stable and biodegradable systems. The PEU hydrogels demonstrate reversible responses to a change in medium temperature from 5 °C to 37 °C, with the swelling ratio at equilibrium varying from 499% to 12%. The hydrogels have a tensile Young’s modulus, ultimate tensile strength and elongation at break in the range of 0.02–0.20 MPa, 0.05–0.47 MPa and 426–623%, respectively, and show high stretchability and full shape recovery after compression. These are similar to the mechanical properties of adipose tissues. In vitro degradation tests show mass losses of 8.7–16.3% and 10.7–20.7% without and with the presence of lipase enzyme for 31 days, respectively. In vitro cell tests show clear evidence that some of the PEU hydrogels are suitable for culturing adipose-derived stem cells and dermal fibroblasts and hence for future soft tissue regeneration. The functionalities of the PEU hydrogels were also evaluated for potential applications in drug delivery, thermal actuation and ultralow power generation. The results demonstrate the versatility of these PEU hydrogels for a variety of biomedical and engineering application

Drosophila mini-white model system: new insights into positive position effects and the role of transcriptional terminators and gypsy insulator in transgene shielding

The white gene, which is responsible for eye pigmentation, is widely used to study position effects in Drosophila. As a result of insertion of P-element vectors containing mini-white without enhancers into random chromosomal sites, flies with different eye color phenotypes appear, which is usually explained by the influence of positive/negative regulatory elements located around the insertion site. We found that, in more than 70% of cases when mini-white expression was subject to positive position effects, deletion of the white promoter had no effect on eye pigmentation; in these cases, the transposon was inserted into the transcribed regions of genes. Therefore, transcription through the mini-white gene could be responsible for high levels of its expression in most of chromosomal sites. Consistently with this conclusion, transcriptional terminators proved to be efficient in protecting mini-white expression from positive position effects. On the other hand, the best characterized Drosophila gypsy insulator was poorly effective in terminating transcription and, as a consequence, only partially protected mini-white expression from these effects. Thus, to ensure maximum protection of a transgene from position effects, a perfect boundary/insulator element should combine three activities: to block enhancers, to provide a barrier between active and repressed chromatin, and to terminate transcription