2,380 research outputs found
mtDNA Heteroplasmy in Hair Shafts versus Buccal Swabs for Forensic Applications
Mitochondrial DNA (mtDNA) analysis has several forensic applications such as criminal investigations, identification of human remains, and missing person investigations. It is also the only type of DNA that is available from certain sample types such as hair shafts. The presence of mtDNA heteroplasmy within and between tissue types can lead to mtDNA sequence differences when comparing samples originating from the same individual. Studies on mtDNA heteroplasmy are increasingly being carried out for their implications in forensic interpretation of mtDNA sequences. Specifically, mtDNA in buccal swabs compared to hair samples from one individual may show differences in sequence due to heteroplasmy, and casework samples compared to reference swabs may exhibit differences that must be correctly interpreted to prevent faulty conclusions made by investigators and scientists alike. Establishing expected rates of heteroplasmy in mtDNA extracted from hair shaft samples and comparison to mtDNA extracted from buccal swab samples will lead to increased confidence in mtDNA interpretation.
The goals of this study were to (1) successfully sequence the entire mtDNA control region from buccal swab samples from 5 volunteers using Sanger sequencing, (2) amplify smaller (\u3c300bp) sections of overlapping regions of the mtDNA control region from 15-20 hair shafts collected from three areas of the scalp using three methods of DNA extraction, and (3) evaluate mtDNA sequences from hair shafts and buccal swabs to identify heteroplasmy within and between samples. Overall, only 20% of the extracted hair samples resulted in half of Hypervariable Region 1 (HV1) being successfully sequenced from either the 5´ or 3´ end. Two out of five participants showed length heteroplasmy in the poly-cytosine region beginning at position 303 within the HV2 region. Point heteroplasmy was observed in one participant at one position in the buccal swab (nucleotide position 16093) as well as at two different positions in a hair sample (nucleotide positions 16258 and 16288) that did not show heteroplasmy in the buccal swab. The heteroplasmy seen in the buccal swab could not be compared to the hair sample as position 16093 did not fall within the successfully sequenced region in the hair. Although only a small subset of hair shafts were successfully sequenced, this study has succeeded in showing that mtDNA heteroplasmy seen in a hair shaft may not be present in buccal swab mtDNA. Further research into rates of heteroplasmy in hair shafts vs. buccal swabs is paramount to bettering the interpretative abilities of forensic scientists working with mtDNA and preventing false exclusions
Deterministic and stochastic study for a microscopic angiogenesis model: applications to the Lewis lung carcinoma
Angiogenesis modelling is an important tool to understand the underlying mechanisms yielding tumour growth. Nevertheless, there is usually a gap between models and experimental data. We propose a model based on the intrinsic microscopic reactions defining the angiogenesis process to link experimental data with previous macroscopic models. The microscopic characterisation can describe the macroscopic behaviour of the tumour, which stability analysis reveals a set of predicted tumour states involving different morphologies. Additionally, the microscopic description also gives a framework to study the intrinsic stochasticity of the reactive system through the resulting Langevin equation. To follow the goal of the paper, we use available experimental information on the Lewis lung carcinoma to infer meaningful parameters for the model that are able to describe the different stages of the tumour growth. Finally we explore the predictive capabilities of the fitted model by showing that fluctuations are determinant for the survival of the tumour during the first week and that available treatments can give raise to new stable tumour dormant states with a reduced vascular network
Searching for Organics Preserved in 4.5 Billion Year Old Salt
Our understanding of early solar system fluids took a dramatic turn a decade ago with the discovery of fluid inclusion-bearing halite (NaCl) crystals in the matrix of two freshly fallen brecciated H chondrite falls, Monahans and Zag. Both meteorites are regolith breccias, and contain xenolithic halite (and minor admixed sylvite -- KCl, crystals in their regolith lithologies. The halites are purple to dark blue, due to the presence of color centers (electrons in anion vacancies) which slowly accumulated as 40K (in sylvite) decayed over billions of years. The halites were dated by K-Ar, Rb-Sr and I-Xe systematics to be 4.5 billion years old. The "blue" halites were a fantastic discovery for the following reasons: (1) Halite+sylvite can be dated (K is in sylvite and will substitute for Na in halite, Rb substitutes in halite for Na, and I substitutes for Cl). (2) The blue color is lost if the halite dissolves on Earth and reprecipitates (because the newly-formed halite has no color centers), so the color serves as a "freshness" or pristinity indicator. (3) Halite frequently contains aqueous fluid inclusions. (4) Halite contains no structural oxygen, carbon or hydrogen, making them ideal materials to measure these isotopic systems in any fluid inclusions. (5) It is possible to directly measure fluid inclusion formation temperatures, and thus directly measure the temperature of the mineralizing aqueous fluid. In addition to these two ordinary chondrites halite grains have been reliably reported in several ureilites, an additional ordinary chondrite (Jilin), and in the carbonaceous chondrite (Murchison), although these reports were unfortunately not taken seriously. We have lately found additional fluid inclusions in carbonates in several additional carbonaceous chondrites. Meteoritic aqueous fluid inclusions are apparently relatively widespread in meteorites, though very small and thus difficult to analyze
41: Pre-Transplant Administration of Keratinocyte Growth Factor Affects Peripheral T-cell Homeostasis Through Increased Recent Thymic Emigrant Export and Affects the Course of Murine Chronic Graft-Vs.-Host Disease
Ремоделювання великої підшкірної вени при посттромбофлебітичній хворобі
We analyzed the features of remodeling of the structural components of the great saphenous vein in case of postthromboflebitic disease. We set the following features: thrombosis with formation of capillary angiomatosis, the predominance of sclerotic processes according to the type of muscular-elastic and muscular – fibrous, circular and focal narrowing of the lumen of the vein, angiogenesis of tunica media, hyperelastosis with dyscomplexation of elastic fibers, swelling, lymphocytic infiltration and morphological outcome of capillary-metabolic failure.Проаналізовано особливості ремоделювання структурних компонентів великої підшкірної вени при посттромбофлебітичній хворобі. Встановлено такі особливості: тромбоз із формуванням капілярного ангіоматозу, переважання фібропластичних процесів за типом м’язово-еластичного і м’язово-фіброзного, циркулярного та осередкового звуження просвіту вени, неоангіогенез середньої оболонки, гіпереластоз із дискомплексацією еластичних волокон, набряк, лімфоцитарну інфільтрацію та морфологічні прояви капілярно-метаболічної недостатності
ФАКТОРИ РИЗИКУ ПРОФЕСІЙНИХ ЗАХВОРЮВАНЬ МЕДИЧНИХ ПРАЦІВНИКІВ (ОГЛЯД ЛІТЕРАТУРИ)
Вивчення факторів ризику професійних захворювань становить із практичної і соціальної точок зору актуальну медико-соціальну проблему, що вважається теоретичною основою щодо розробки методів їх профілактики. Дані офіційних
статистичних звітів свідчать, що в Україні понад 60,0 % із 1,1 млн медичних працівників працюють у шкідливих та небезпечних умовах. У структурі професійних захворювань медичних працівників перше місце займає туберкульоз (80–100 %, у середньому – 87,7 %), друге – захворювання опорно-рухового апарату (від 1,3 до 6,7 %, у середньому – 3,1 %), на третьому місці алергічні захворювання – від 1,0 до 5,1 % (у середньому 2,3 %).
Мета дослідження – вивчити й узагальнити причини професійних захворювань медичних працівників в Україні.
Матеріали і методи. Професійна захворюваність медичного персоналу зумовлена впливом комплексу факторів ризику: механічних, фізичних, хімічних, біологічних, нервово-емоційних. Негативним механічним впливам піддаються медичні працівники із статичними умовами праці. Шкідлива дія фізичного фактора суттєво збільшується у наш час за умов широкого впровадження у лікувальний і діагностичний процеси апаратури із світловим, електромагнітним та радіоактивним випромінюванням. В умовах швидкого розвитку хімічної та фармацевтичної промисловості суттєво зросла кількість хімічних речовин, які мають здатність спричиняти не тільки лікувальний ефект на пацієнта, а й здійснювати негативний вплив на медичних працівників при систематичному їх використанні.
Результати досліджень та їх обговорення. Актуальною проблемою охорони здоров’я України залишаються група професійних захворювань, спричинених збудниками туберкульозу, токсоплазмозу, вірусного гепатиту, мікозів шкіри, сифілісу, ВІЛ-інфекції. Ризик зараження ВІЛ складає близько 0,3 % і досягає 10,0 % на вірус гепатиту С, і 30,0 % – вірус гепатиту В. В Україні, за даними Міністерства охорони здоров’я, щороку виявляють 30,0–50,0 тис. хворих на цю недугу (84,1 на 100 тис. населення). Прояви ураження емоційної сфери як симптомокомплекс професійного вигоряння виявлено майже в 80 % лікарів-психіатрів, психотерапевтів, психіатрів-наркологів, у 61,8 % лікарів-стоматологів, у 60,6 % медичних сестер онкологічних відділень.
Висновки. Розподіл випадків професійних захворювань медичних працівників України серед різних закладів у 2011–2017 рр. показав, що найбільшу кількість профзахворювань реєструють у закладах протитуберкульозного профілю – 70,1–95,5 %. Від 3,0 до 16,4 % усіх професійних захворювань у медичній галузі реєструють у лікарнях загального профілю, від 1,5 до 10,2 – у лікарнях психоневрологічного профілю, 1,9–3,0 % – у бюро судово-медичної експертизи та 2,6–3,0 % – у наукових закладах
A Closed-Form Solution of the Multi-Period Portfolio Choice Problem for a Quadratic Utility Function
In the present paper, we derive a closed-form solution of the multi-period
portfolio choice problem for a quadratic utility function with and without a
riskless asset. All results are derived under weak conditions on the asset
returns. No assumption on the correlation structure between different time
points is needed and no assumption on the distribution is imposed. All
expressions are presented in terms of the conditional mean vectors and the
conditional covariance matrices. If the multivariate process of the asset
returns is independent it is shown that in the case without a riskless asset
the solution is presented as a sequence of optimal portfolio weights obtained
by solving the single-period Markowitz optimization problem. The process
dynamics are included only in the shape parameter of the utility function. If a
riskless asset is present then the multi-period optimal portfolio weights are
proportional to the single-period solutions multiplied by time-varying
constants which are depending on the process dynamics. Remarkably, in the case
of a portfolio selection with the tangency portfolio the multi-period solution
coincides with the sequence of the simple-period solutions. Finally, we compare
the suggested strategies with existing multi-period portfolio allocation
methods for real data.Comment: 38 pages, 9 figures, 3 tables, changes: VAR(1)-CCC-GARCH(1,1) process
dynamics and the analysis of increasing horizon are included in the
simulation study, under revision in Annals of Operations Researc
NUMERICAL ANALYSIS OF LIQUID FRACTION AND HEAT FLUX IN THE SOLIDIFICATION PROCESS OF ERYTHRITOL IN SPHERES
The demand for renewable energy resources and the need for the development of components which increase how it collects, transforms, stores and distributes this energy, emphasizes the importance of improving current technological systems to meet these demands. Phase change materials (PCM) offer great potential in this area. as they can increase energy efficiency in thermal systems as well as save energy by storing solar energy or waste heat from industrial processes, which is made possible by the high amount of energy stored per mass and volume unit, with low temperature variation. Therefore, it is of high importance that the suggested mathematical and numerical models are capable of analyzing its energy performance. The present work uses a mathematical and numerical model of Computational Fluid Dynamics (CFD), capable of reproducing the solidification process of erythritol in spheres of 10, 20, 30 and 40 mm diameters, with temperature differences of 10, 15, 20, 25, 30 and 40 K between the sphere wall and the phase change temperature of the material. The problem is considered two- dimensional and transient. The model consists of mass, energy, momentum and volume fraction equations. The mathematical and numerical model is validated with experimental results from the literature, presenting good agreement between them. After space and time discretization tests, we analyze liquid fraction over time and heat flux at the sphere wall. The results show that liquid fraction suffers a strong reduction in the beginning of the solidification process due to the high heat flux in the early stages. As the solid layer near the wall increases, it causes an increase in thermal resistance, causing a significant reduction in heat flux
A photoelectron spectroscopy study of the electronic structure evolution in CuInSe2-related compounds at changing copper content
Evolution of the valence-band structure at gradually increasing copper content has been analysed by x-ray photoelectron spectroscopy (XPS) in In2Se3, CuIn5Se8, CuIn3Se5, and CuInSe2 single crystals. A comparison of these spectra with calculated total and angular-momentum resolved density-of-states (DOS) revealed the main trends of this evolution. The formation of the theoretically predicted gap between the bonding and non-bonding states has been observed in both experimental XPS spectra and theoretical DOS
- …