Селекция и компенсация сигналов спуфинга в гражданской аппаратуре потребителя глобальной навигационной спутниковой системы с многоканальной приемной системой

A method for selecting spoofing signals in consumer equipment with a multichannel antenna system is proposed. The method provides for consistent filtering of the received signals at the outputs of all antenna system elements and by ranging codes of all navigation satellites, detection and measurement of the time delay of the true and false navigation signals in each code channel by the output signal of one of the antenna system elements, measurement of the phase difference of the signals at the outputs of the antenna system elements and the selected reference element for the estimated time delay in each channel by code. Compensation of spoofing signals is carried out in the spatial domain by estimating the correlation matrix of processes at the outputs of the antenna system channels by the corresponding countdown of code channel signals after matched filtering and forming of a weight vector while minimizing the output power of spoofing signals by directly inverting the estimate of the correlation matrix and carrying out weight processing of the adopted implementation. The simulation results are presented, confirming the efficiency of the method.Предложен метод селекции сигналов спуфинга (от англ. spoofing – подмена) в гражданской аппаратуре потребителя с многоканальной антенной системой. Метод предполагает согласованную фильтрацию принимаемых сигналов на выходах всех элементов антенной системы и по дальномерным кодам всех навигационных спутников, обнаружение и измерение времен задержки истинных и ложных навигационных сигналов в каждом кодовом канале по выходному сигналу одного из элементов антенной системы, измерение разности фаз сигналов на выходах элементов антенной системы и выбранного опорного элемента по расчетным временам задержки в каждом канале по коду. Компенсация сигналов спуфинга осуществляется в пространственной области путем оценивания корреляционной матрицы процессов на выходах каналов антенной системы по соответствующим отсчетам сигналов кодовых каналов после согласованной фильтрации, формирования весового вектора при минимизации выходной мощности сигналов спуфинга путем непосредственного обращения оценки корреляционной матрицы и проведения весовой обработки принятой реализации. Представлены результаты моделирования, подтверждающие эффективность метода

Spoofing’s Selection and Compensation in the Global Navigation Satellite System Consumer Navigation Equipment with Multi-Channel Antenna System

A method for selecting spoofing signals in consumer equipment with a multichannel antenna system is proposed. The method provides for consistent filtering of the received signals at the outputs of all antenna system elements and by ranging codes of all navigation satellites, detection and measurement of the time delay of the true and false navigation signals in each code channel by the output signal of one of the antenna system elements, measurement of the phase difference of the signals at the outputs of the antenna system elements and the selected reference element for the estimated time delay in each channel by code. Compensation of spoofing signals is carried out in the spatial domain by estimating the correlation matrix of processes at the outputs of the antenna system channels by the corresponding countdown of code channel signals after matched filtering and forming of a weight vector while minimizing the output power of spoofing signals by directly inverting the estimate of the correlation matrix and carrying out weight processing of the adopted implementation. The simulation results are presented, confirming the efficiency of the method

Селекция и компенсация сигналов спуфинга в гражданской аппаратуре потребителя глобальной навигационной спутниковой системы с многоканальной приемной системой

A method for selecting spoofing signals in consumer equipment with a multichannel antenna system is proposed. The method provides for consistent filtering of the received signals at the outputs of all antenna system elements and by ranging codes of all navigation satellites, detection and measurement of the time delay of the true and false navigation signals in each code channel by the output signal of one of the antenna system elements, measurement of the phase difference of the signals at the outputs of the antenna system elements and the selected reference element for the estimated time delay in each channel by code. Compensation of spoofing signals is carried out in the spatial domain by estimating the correlation matrix of processes at the outputs of the antenna system channels by the corresponding countdown of code channel signals after matched filtering and forming of a weight vector while minimizing the output power of spoofing signals by directly inverting the estimate of the correlation matrix and carrying out weight processing of the adopted implementation. The simulation results are presented, confirming the efficiency of the method

‘Fish out of water’: a cross-sectional study on the interaction between social and neighbourhood effects on weight management behaviours

Objective: To analyse whether an individual’s neighbourhood influences the uptake of weight management strategies and whether there is an interaction between individual socio-economic status and neighbourhood deprivation. Methodology: Data were collected from the Yorkshire Health Study (2010–2012) for 27 806 individuals on the use of the following weight management strategies: ‘slimming clubs’, ‘healthy eating’, ‘increasing exercise’ and ‘controlling portion size’. A multi-level logistic regression was fit to analyse the use of these strategies, controlling for age, sex, body mass index, education, neighbourhood deprivation and neighbourhood population turnover (a proxy for neighbourhood social capital). A cross-level interaction term was included for education and neighbourhood deprivation. Lower Super Output Area was used as the geographical scale for the areal unit of analysis. Results: Significant neighbourhood effects were observed for use of ‘slimming clubs’, ‘healthy eating’ and ‘increasing exercise’ as weight management strategies, independent of individual- and area-level covariates. A significant interaction between education and neighbourhood deprivation was observed across all strategies, suggesting that as an area becomes more deprived, individuals of the lowest education are more likely not to use any strategy compared with those of the highest education. Conclusions: Neighbourhoods modify/amplify individual disadvantage and social inequalities, with individuals of low education disproportionally affected by deprivation. It is important to include neighbourhood-based explanations in the development of community-based policy interventions to help tackle obesit

A randomised trial found online questionnaires supplemented by postal reminders generated a cost-effective and generalisable sample, but don't forget the reminders.

OBJECTIVE: To compare the response rates, data completeness and representativeness of survey data produced by online and postal surveys. STUDY DESIGN AND SETTING: A randomised trial nested within a cohort study in Yorkshire, United Kingdom. Participants were randomised to receive either an electronic (online) survey questionnaire with paper reminder (N=2982), or paper questionnaire with electronic reminder (N=2855). RESULTS: Response rates were similar for electronic contact and postal contacts (50.9% versus 49.7%, difference = 1.2%, 95% confidence interval -1.3% to 3.8%). The characteristics of those responding to the two groups were similar. Participants nevertheless demonstrated an overwhelming preference for postal questionnaires, with the majority responding by post in both groups. CONCLUSION: Online survey questionnaire systems need to be supplemented with a postal reminder to achieve acceptable uptake, but doing so provides a similar response rate and case mix when compared to postal questionnaires alone. For large surveys, online survey systems may be cost saving

Bacterial factors of cariogenicity (literature review)

Introduction: According to the 2003 WHO report, dental caries affects from 60% to 90% of school-age children and adults that makes it one of the most common diseases worldwide. The aim was to systematize data about the modern conception of plaque formation and role of microorganisms in its development.Materials and methods: Biblosemantic, 50 medical literature sources were systematically reviewed as the material for the research.Review: According to Miller's theory, oral microorganisms can decompose dietary carbohydrates into acids, which in turn dissolve the calcium phosphates found in the enamel, causing it demineralisation Along with Streptococcus mutans, nowadays some other bacteria as Streptococcus sorbinus, Lactobacillus spp. and Actinomyces spp. have been well studied as caries contributors. However, the disease is related to plaque-mediated, because a much larger number of normal oral microflora representatives are involved in creating favourable preconditions for its development. There are a lot of original research papers about a role of bacteria in caries decay but compositions and characters of oral microflora are changing nowadays. Therefore, authors show the main cariogenic bacteria and their factors of pathogenicity which create special conditions for caries lesions. Modern concepts of dental plaque formation and pathogenesis of plaque-assosiative diseases are presented according to the new actual dental research. A lot of attention is paid to the biochemical properties of cariogenic bacteria and chemical process in biofilm. Role of acid and alkali production by oral bacteria in caries decay are shown in this article. Moreover, mechanisms of bacterial acid-fast and acid-tolerance are presented.Conclusions: Analysis of literature demonstrates a lot of bacterial pathogenicity factors which play key role in caries development

Personalised versus standard text message prompts for increasing trial participant response to telephone follow-up: an embedded randomised controlled retention trial

Background Improving retention within randomised controlled trials is important. The effectiveness of different strategies can be assessed using a Study Within A Trial (SWAT). Previous research has shown personalised text message reminders improve clinic attendance rates; however, the results are mixed on improving postal questionnaire return. This SWAT aims to assess whether personalised text message reminders improve completion rates for scheduled telephone follow-ups. Methods This SWAT is a two-arm, multi-centre randomised controlled trial with equal allocation. The host trial was the Melatonin for Anxiety prior to General anaesthesia In Children trial (ISRCTN 18296119), where the child’s caregiver was to answer a scheduled telephone follow-up 14 days post-surgery; participants for the SWAT were therefore the caregiver. Text messages were sent 24–48 h before the scheduled call and the personalised version contained the first name of the caregiver which was omitted in the non-personalised version. The primary outcome was questionnaire completion rate, defined as the proportion of caregivers successfully contacted, and completed any of the questionnaires, over the telephone within the follow-up window (day 14 + 7 days). Results The SWAT included 100 of the 110 (91%) participants randomised into the host trial. Randomisation within the SWAT was equal between non-personalised (n = 50) and personalised (n = 50) interventions. The overall questionnaire response rate was 73% with a difference between the two interventions of 68% in the non-personalised text message arm and 78% in the personalised text message arm. The adjusted absolute risk difference was 7.1% (95% confidence interval = −10.2%, 24.4%). There was no difference in either the time to response or the number of contact attempts between the two interventions. Conclusions There is some evidence that personalised text messages could be effective at increasing response rates when data is collected via telephone and in a population of caregivers for paediatric trial participants. However, similar SWATs have shown mixed results. Given the low-cost and low risks associated with personalising text message reminders, this SWAT could be implemented easily in other RCTs scheduling telephone follow-up appointments. Trial Registration ISRCTN 18296119, SWAT 35 (MRC Northern Ireland Network for Trials Methodology Network)

Загальна мікробіологія, вірусологія та імунологія. Збірник завдань з мікробіології, вірусології та імунології для підготовки до тестового іспиту “Крок 1”

Collection contains to the test of task, which are intended for the current, intermediate and eventual control of knowledge of dental and medical faculty students; Збірник містить тестові завдання, які призначені для поточного, проміжного і кінцевого контролю знань студентів стоматологічного факультету

Susceptibility of planktonic and film forms of candida glabrata and candida albicans to cationic surfactant antiseptics

The aim of the study was to investigate the sensitivity of planktonic and film forms of C. albicans and C. glabrata to cationic surfactant antiseptics. Materials and methods. The study was based on investigating 20 clinical strains of C. albicans and 15 C. glabrata isolated from surgical inpatientsю. The sensitivity of planktonic forms of investigated strains to antiseptic agents was quantitatively evaluated by two-fold serial dilutions (macrodilution) in Sabouraud liquid nutrient medium. Biofilm-forming properties of clinical strains C. albicans and C. glabrata were assessed by using the Christensen’s spectrophotometric method (MtP-test “microtiter plate test”). The influence of the antiseptics on C. albicans and C. glabrata film forms was assessed by the reproduction of the biofilms according to the above-described procedure with adding antiseptics in sub-bacteriostatic concentrations and the subsequent spectrophotometric ODU assessment. In the study we used antiseptics based on cationic surfactants, chlorhexidine digluconate 0.05 (Chlorhexidine-KR, manufactured by PJSC “Khimfarmzavod “Chervona zirka"”, Kharkiv, Ukraine (CHH)) and decamethoxin 0.2 (Decasan, produced by Yuria-Farm LLC ", Kyiv, Ukraine (DCM)). Results. According to the research results, lower sensitivity of C. glabrata strains to CHH was found, compared to the sensitivity of C. albicans strains. In addition, the activity of DCM in the investigated representatives of Candida spp. did not differ significantly. Clinical strains of C. glabrata were more susceptible to DCM compared to their susceptibility to CHH. C. albicans strains showed medium film-forming properties, while C. glabrata - high. The investigated cationic surfactant antiseptics possessed the same degree of activity on the film-forming properties of clinical strains of Candida spp. Conclusions. Cationic surfactant antiseptics (CHH and DCM) possess antifungal activity against planktonic and film forms of C. albicans and C. glabrata; Дослідити чутливість планктонних і плівкових форм C. albicans та C. glabrata до антисептиків на основі катіонних поверхнево-активних речовин (ПАР). Матеріали та методи дослідження. Об’єктом дослідження стали 20 клінічних штамів C. albicans та 15 C. glabrata, виділених від хворих хірургічних відділень. Чутливість планктонних форм досліджуваних штамів мікроорганізмів до антисептичних засобів вивчали за допомогою кількісного макрометоду подвійних серійних розведень у рідкому поживному середовищі Сабуро. Біоплівкоутворюючі властивості досліджуваних клінічних штамів визначали за допомогою спектрофотометричного методу за G.D. Christensen (MtP-test). Вплив антисептиків на плівкові форми Candida spp. визначали шляхом відтворення біоплівок за вищеописаною методикою з додаванням суббактеріостатичних концентрацій антисептиків. В дослідженні використовували антисептики на основі катіонних ПАР хлоргексидину біглюконат 0,05 (Хлоргексидин-КР, виробництва ПАТ «Хімфармзавод «Червона зірка», м. Харків, Україна (ХГ)) та декаметоксин 0,2 (Декасан, виробництва ТОВ «Юрія-Фарм», м. Київ, Україна (ДКМ)). Результати. За результатами досліджень встановлено нижчу чутливість штамів C. glabrata до ХГ, у порівнянні з чутливістю штамів C. albicans. Поряд з цим, активність ДКМ щодо досліджуваних представників Candida spp. достовірно не відрізнялась. Клінічні штами C. glabrata виявилися більш чутливими до ДКМ порівняно з їх чутливістю до ХГ. Штами C. albicans проявили середні плівкоутворюючі властивості, в той час як C. glabrata – високі. Досліджувані антисептики на основі катіонних ПАР володіли в однаковій мірі потужною активністю щодо плівкоутворення клінічних штамів Candida spp. Висновки. Антисептики на основі катіонних ПАР (ХГ та ДКМ) володіють протигрибковою активністю щодо планктонних і плівкових форм клінічних штамів C. albicans та C. glabrata