scholarly journals Secondary DNA transfer on denim using a human blood analogue

2021 ◽  
Author(s):  
Rebecca Ridings ◽  
Alon Gabriel ◽  
Colin I Elliott ◽  
Aaron Shafer

DNA quantification technology has increased in accuracy and sensitivity, now allowing for detection and profiling of trace DNA. Secondary DNA transfer occurs when DNA is deposited via an intermediary source (e.g. clothing, tools, utensils). Multiple courtrooms have now seen secondary transfer introduced as an explanation for DNA being present at a crime scene, but sparse experimental studies mean expert opinions are often limited. Here, we used bovine blood and indigo denim substrates to quantify the amount of secondary DNA transfer and quality of STRs under three different physical contact scenarios: passive, pressure, and friction. We showed that the DNA transfer was highest under a friction scenario, followed by pressure and passive treatments. The STR profiles showed a similar, albeit less pronounced trend, with correctly scored alleles and genotype completeness being highest under a friction scenario, followed by pressure and passive. DNA on the primary substrate showed a decrease in concentration and genotype completeness both immediately and at 24 hours, suggestive of a loss of DNA during the primary transfer. The majority of secondary transfer samples amplified less than 50% of STR loci regardless of contact type. This study showed that while DNA transfer is common between denim, this is not manifested in full STR profiles. We discuss the possible technical solutions to partial profiles from trace DNA, and more broadly the ubiquity of secondary DNA transfer.

Author(s):  
S.U. Lyapina ◽  
◽  
V.N. Tarasova ◽  
V.B. Ruchkin ◽  
E.O. Koscheeva ◽  
...  

The quality issues of new services directly affect the competitiveness of service organizations. However, the introduction of new services to the market is often limited only to the construction of the logistics of business processes, and the design applies only to technological equipment and infrastructure, the quality of which ultimately does not always ensure the quality of the services provided. At the same time, quality management affects mainly operational aspects, that is, it covers the later stages of the service life cycle. In resource-intensive service industries (for example, transport, communications, etc.), the high cost of equipment and infrastructure reduces the possibility of changes in service delivery technologies to improve their quality, which leads to inefficiency and market failures due to the fact that the new service does not match the real needs of customers. Despite this, forecasting and planning the quality of a service at the stage «making a decision» to launch a new service on the market remains largely without sufficient attention. The authors prove the need to design the quality of services at the stage «making a decision» to bring new services to the market. The purpose of the article is to describe the approach developed by the authors to assessing the quality of projected services at the early stages of their life cycle, which makes it possible to integrate qualitative and quantitative indicators of the future service and take into account the forecast requests of customers. The proposed approach has two features: (1) forecasting customer requirements for the quality of services is based on the results of machine learning based on data on existing and potential customers, as well as on the basis of the accumulated knowledge base of customer experience and expert opinions; (2) multi-criteria optimization is used, while some of the optimized parameters are discrete and high-quality. In conclusion, the authors demonstrated the advantages of the developed model on the examples of transport and logistics business in the field of passenger and freight transportation in Russia.


Author(s):  
T. N. Antipova ◽  
D. S. Shiroyan

The system of indicators of quality of carbon-carbon composite material and technological operations of its production is proved in the work. As a result of the experimental studies, with respect to the existing laboratory equipment, the optimal number of cycles of saturation of the reinforcing frame with a carbon matrix is determined. It was found that to obtain a carbon-carbon composite material with a low cost and the required quality indicators, it is necessary to introduce additional parameters of the pitch melt at the impregnation stage.


2021 ◽  
Vol 11 (8) ◽  
pp. 3444
Author(s):  
Sergey A. Lavrenko ◽  
Dmitriy I. Shishlyannikov

The authors focus on the process of potash ore production by a mechanized method. They show that currently there are no approved procedures for assessing the performance of heading-and-winning machines operating in the conditions of potash mines. This causes difficulties in determining the field of application of heading-and-winning machines, complicates the search for implicit technical solutions for the modernisation of existing models of mining units, prohibits real-time monitoring of the stability of stope-based technological processes and makes it difficult to assess the performance of the services concerning mining enterprises. The work represents an aggregate assessment of the performance of heading-and-winning machines for potash mines by determining complex indicators describing the technological and technical levels of organising the work in stopes. Such indicators are the coefficients of productivity and energy efficiency, respectively. Experimental studies have been carried out in the conditions of the potash mine of the Verkhnekamskoye potassium-magnesium salt deposit to assess the performance of the latest and most productive Ural-20R heading-and-winning machines manufactured in Russia. Using the above methodological approaches, this paper shows that the unsatisfactory technological performance of the studied machine is due to the low productivity of the mine district transport. The average productivity coefficient was 0.29. At the same time, high values of the energy efficiency coefficient show that the productivity of the machine is on par with design conditions.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Nicole E. van Gelder ◽  
Ditte L. van Haalen ◽  
Kyra Ekker ◽  
Suzanne A. Ligthart ◽  
Sabine Oertelt-Prigione

Abstract Background The COVID-19 pandemic and lockdown evoked great worries among professionals in the field of domestic violence and abuse (DVA) as they expected a rise of the phenomenon. While many countries reported increased DVA, the Netherlands did not. To understand this discrepancy and the overall impact of the lockdown on DVA support services, we interviewed DVA professionals about their experiences with DVA during the rise of COVID-19, the impact of the lockdown on clients and working conditions, and views on eHealth and online tools. Methods Semi-structured interviews were conducted among 16 DVA professionals with various specializations. This data was analyzed using open thematic coding and content analysis. Results Most professionals did not see an increase in DVA reports but they did notice more severe violence. They experienced less opportunities to detect DVA and worried about their clients’ wellbeing and the quality of (online) care. Furthermore, their working conditions rapidly changed, with working from home and online, and they expressed frustration, insecurity and loneliness. Professionals feel eHealth and online tools are not always suitable but they do see them as an opportunity to increase reach and maintain services when physical contact is not possible. Conclusion This study suggests DVA was probably under-detected during the lockdown rather than not having increased. The Dutch system heavily relies on professionals to detect and report DVA, suggesting a need for critical evaluation of the accessibility of professional help. Professionals experienced significant challenges and should themselves be supported psychologically and in their changed work practices to maintain their ability to aid survivors.


Author(s):  
V. N. Pristupa ◽  
D. S. Torosyan

The purpose of the work was to study and identify the main factors aff ecting the quantity and quality of beef produced and sold in the Southern Federal district. A comparative assessment of the growth, development, formation of meat productivity and quality of beef of young animals of beef, dual and dairy breeds with stall-pasture technology and intensive rearing in the industrial complex. Experimental studies have been carried out in farms in the Rostov region. The object of research was cows with calves of Kalmyk, Hereford, Aberdeen-Angus, Russian komolaya, Kazakh White-headed breeds, as well as young animals of the same breeds, in addition, Black-and-White and Swiss breeds. Removable live weight in Hereford steers at 18 months of age was 658,0 kg, and Aberdeen-Angus – 655,2 kg. Domestic steers of Kalmyk were 41–44 kg lower in live weight than their herdmates of two imported breeds. However, with intensive rearing at 18 months of age, steers of Kalmyk breed had a removable live weight of more than 613,7 kg and a carcass weight of 326 kg. The yield of hot carcass was 55,4 %, and the slaughter yield was 58,89 %, which was only 1–2 % lower than the world’s leading beef breeds. It has been found when analyzing the results of boning the half-carcasses of experimental steers that the biggest weight of half-carcasses and the content of muscle and fat tissue in them in absolute terms were in Hereford steers. Steers of Kalmyk breed took the third place in terms of weight of large-sized semi–fi nished products and signifi cantly lost to Aberdeen-Angus herdmates by 7,3 kg or 6,5 %, and Hereford steers by 9,2 kg or 8,3 %. The results obtained prove the expediency of using stallpasture technology in the dry-steppe zone of the Southern Federal district when rearing young animals for beef up to 350–400 kg live weight at 15 months of age and its subsequent intensive rearing under industrial technology, in order to obtain the live weight of more than 570 kg and produce cost-eff ective beef.


Author(s):  
М.А. Минасян ◽  
А.М. Минасян ◽  
Ц. Цзэн

Объектом исследования является опытный образец запатентованной канатностержневой муфты (КСМ) «MAMSAR+А» в качестве привода дизель-генераторного агрегата ДГА-8,83 мощностью 9,56 кВт при частоте вращения 1500 мин-1 с дизелем 2Ч 8,5/11 и генератором «ГК-5,6». Целью исследования является экспериментальная оценка коэффициента эффективности вибрационной защиты КСМ. Поставленная цель достигается разработкой и реализацией оригинальной методики экспериментальной оценки коэффициента эффективности КСМ с анализом и выводами результатов экспериментальных исследований. Экспериментальные исследования проводятся в два этапа. Первый этап – с упругим соединением КСМ, второй этап – с жестким соединением. Оригинальность методики экспериментальной оценки коэффициента эффективности вибрационной защиты КСМ главным образом заключается в том, что между двумя этапами экспериментальных исследований КСМ не демонтируется. Следовательно, качество центровки не нарушается. Усредненный коэффициент эффективности виброизоляции КСМ составляет от 3 до 8 дБ. The object of this research is a prototype of the patented wire rope coupling (KSM) "MAMSAR+A" as a drive for a diesel-generator unit DGA-8.83 with a power of 9.56 kW at a speed of 1500 min-1 with a 2CH 8.5/11 diesel engine and a generator "KG-5.6". The aim of the research is to experimentally evaluate the efficiency coefficient of vibration protection of the KSM. This goal is achieved by developing and implementing an original method for experimental evaluation the efficiency coefficient of the KSM with analysis and conclusions of the results of experimental studies. Experimental studies are conducted in two stages. The first stage - with an elastic connection of the coupling, the second stage - with a rigid connection. The originality of the method of experimental evaluation of the efficiency coefficient of vibration protection of the KSM mainly lies in the fact that the KSM is not dismantled between the two stages of experimental research. Therefore, the quality of alignment is not violated. The average coefficient of vibration isolation efficiency of the KSM is from 3 to 8 dB.


Author(s):  
K.P. Topalov ◽  
◽  
Ye.K. Skoromets ◽  

The article analyzes 249 expert opinions on the quality of medical care from the standpoint of the responsibility of medical workers for their professional activities. The principles of moral responsibility for medical workers are outlined.


Author(s):  
SHAPOVALOVA Nataliia ◽  
VEZHLIVTSEVA Svitlana ◽  
ANTIUSHKO Dmytro

Background. The deficiency of essential nutrients in the human body is the root cause of reduced efficiency, general resistance of the body to various diseases. That is an urgent problem in the context of the spread of coronavirus infection. In this regard, the search for opportunities to meet the needs of the population in food products that contain biologically active substances (BAS) through the use of high-value and at the same time available plant raw materials is extremely important. Marigolds attract special attention among such raw materials. The aim of the work is to study the chemical composition and evaluate the consumer properties of Tagetes L. varieties, zoned in the Kiev region, to prove the possibility of increasing the biological value of pasta by adding to their recipe powder from marigold inflorescences. Materials and methods. The object of research is pasta of B group (noodles). Inflorescences of marigolds of different varieties gathered during the flowering period in July-September 2019–2020 in the territory of Vasylkiv and Obukhiv districts of Kyiv region, Ukraine were used as enriching plant raw materials. The quality of finished pasta was assessed by organoleptic and physicochemical indexes (moisture content and titratable acidity). The content of mineral elements in the fine powder of marigold inflorescences was determined on the EXHERT-3L device, the quantitative composition and BAS identification – by spectrophotometric analysis on the device Specord-200 Analytic Jena UV-vis. The integrated quality index of pasta products was calculated taking into account the importance factors of individual indexes. Results. Comparing the obtained results, we can state that all the studied varieties – Gold Kopfen, Orange Flame, Hawaii, Equinox are characterized by high biological value, regardless of the area of collection. As a result of calculated and experimental studies it was determined that the addition of 7 % of the supplement does not provide the required supply of vitamins and minerals. Replacing the flour in the recipe by 20 % significantly improves the mineral composition, but deteriorates the taste and aromatic properties of pasta. The most optimal and rational amount of added additive is 15 %, as it improves the organoleptic properties of pasta and enriches their BAS. Conclusion. The usage of non-traditional vegetable raw materials, in particular powder from marigold inflorescences, which is rich in biologically active substances, allows not only to expand the range, improve the quality of finished products, but also increase the biological value of the product. The optimal amount of additive –powder from marigold inflorescences, was defined. It is 15 % by weight of flour in the production of noodles. This concentration allows not only to improve the organoleptic properties, but also to increase the content of biologically active substances – vitamins, micro- and macronutrients. The usage of non-traditional natural raw materials (powder from marigold inflorescences) allows to abandon artificial colorsand give the finished pasta a pleasant colorand aroma.


2018 ◽  
Vol 284 ◽  
pp. 1178-1183 ◽  
Author(s):  
D.A. Zherebtcov ◽  
Oksana N. Gruba ◽  
K.R. Smolyakova

The article deals with the method of obtaining a hard chromium coating on details of the "body of rotation" type with the use of an abrasive tool. The influence of the composition and hardness of the elastic abrasive tool on the results of galvanomechanical chromium plating of rotating cylindrical parts has been studied. Binder compositions for an abrasive tool used to improve the roughness of the deposited chromium layer have been developed. A series of experimental studies has been carried out with chromium plating of steel cylindrical parts with simultaneous abrasive processing. Beforehand, an abrasive tool with previously developed binder formulations was manufactured. The obtained results of the influence of the characteristics of the abrasive tool and its pressing force on the chromium-plated part on the quality of the precipitated chromium made it possible to determine the optimum modes for obtaining a coating of the required thickness. Also, a suitable abrasive tool has been chosen to obtain a coating of proper quality.


2012 ◽  
Vol 44 (3) ◽  
pp. 281-286
Author(s):  
A.V. Aleksandrov ◽  
V.V. Aleksandrov

This article deals with the use of computer modeling to develop technical solutions to ensure better quality of alumina-containing sinter. The simulation accounted for the influence of the feed materials on the thermal processes in the furnace. The energy balance (including thermal conductivity, heat convection and radiant heat exchange) was solved assuming steady state. A good correlation was observed for the actual and calculated temperatures of the solids and gases, with less than 15% discrepancy. Using the model of the furnace investigated the possibility of lowering the temperature of sintering by removing heat from the outside of the furnace shell. To reduce the sintering temperature to 1000 ?C length of the refractory lined steel is 5 m, the height of the lining should not exceed - 0.06 m, the required rate of cold water - 54.7 m3/h


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