Dynamic link budget simulation

A new simulator named DLBS (Dynamic Link Budget Simulator) was written to simulate the time-varying communication link between a vehicle that re-enters the atmosphere from the outer space, and a ground station. During the vehicle descent trajectory, communications blackouts typically occur due to the effects of plasma that forms around the vehicle. A companion simulator, AIPT (Antenna In Plasma Tool), evaluates the electric field at the input of the ground station antenna, taking into consideration the vehicle structure, its antenna, the characteristics of plasma at some specified points along the vehicle trajectory, and the obtained values are stored in a file. DLBS processes the data read from the AIPT output file and evaluates the corresponding channel transfer functions. DLBS then allows to simulate the typical telemetry and telecommand links, using both CCSDS standardised and some non standard channel encoding schemes and modulations. For each generated frame, DLBS uses a channel transfer function obtained by adequately interpolating the two nearest transfer functions evaluated in the initial phase. DLBS includes realistic frame, frequency, phase and bit synchronisation, so that synchronisation errors are also included as source of performance degradation, and measures both the average bit and frame error rates, and the bit error rate at frame level, so that it is possible to appreciate the dynamic system behaviour. The paper will show the results obtained for a case stud

Dynamic link budget simulation

A new simulator named DLBS (Dynamic Link Budget Simulator) was written to simulate the time-varying communication link between a vehicle that re-enters the atmosphere from the outer space, and a ground station. During the vehicle descent trajectory, communications blackouts typically occur due to the effects of plasma that forms around the vehicle. A companion simulator, AIPT (Antenna In Plasma Tool), evaluates the electric field at the input of the ground station antenna, taking into consideration the vehicle structure, its antenna, the characteristics of plasma at some specified points along the vehicle trajectory, and the obtained values are stored in a file. DLBS processes the data read from the AIPT output file and evaluates the corresponding channel transfer functions. DLBS then allows to simulate the typical telemetry and telecommand links, using both CCSDS standardised and some non standard channel encoding schemes and modulations. For each generated frame, DLBS uses a channel transfer function obtained by adequately interpolating the two nearest transfer functions evaluated in the initial phase. DLBS includes realistic frame, frequency, phase and bit synchronisation, so that synchronisation errors are also included as source of performance degradation, and measures both the average bit and frame error rates, and the bit error rate at frame level, so that it is possible to appreciate the dynamic system behaviour. The paper will show the results obtained for a case study

Simulating reinforced concrete members. Part 2: displacement-based analyses

A companion paper described the partial-interaction localised properties that require the development of pseudo properties. If the quantification through experimental testing of these pseudo properties could be removed by the use of mechanics-based models, which is the subject of this paper, then this would: (a) substantially reduce the cost of developing new reinforced concrete products by reducing the amount of testing; (b) increase the accuracy of designing existing and novel reinforced concrete members and structures, bearing in mind that experimentally derived pseudo properties are only applicable within the range of the testing from which they were derived; and (c) reduce the cost and increase the accuracy of developing reinforced concrete design rules. This paper deals with the development of pseudo properties and behaviours directly through mechanics, as opposed to experimental testing, and their incorporation into member global simulations. It also addresses the need for a fundamental shift to displacement-based analyses as opposed to strain-based analyses.Deric J. Oehlers, Phillip Visintin, Jian-Fei Chen and Tim J. Ibel

Survey vs Scraped Data: Comparing Time Series Properties of Web and Survey Vacancy Data

This paper studies the relationship between a vacancy population obtained from web crawling and vacancies in the economy inferred by a National Statistics Office (NSO) using a traditional method. We compare the time series properties of samples obtained between 2007 and 2014 by Statistics Netherlands and by a web scraping company. We find that the web and NSO vacancy data present similar time series properties, suggesting that both time series are generated by the same underlying phenomenon: the real number of new vacancies in the economy. We conclude that, in our case study, web-sourced data are able to capture aggregate economic activity in the labor market

Identification and ethnic diversity underlie support for multicultural rights : a multilevel analysis in Bulgaria

Bulgaria is historically a multicultural society, composed of the Bulgarian (ethnic) majority and a number of ethnic minorities among which Bulgarian Turks and Roma are the largest. Both minority communities are stigmatized in contemporary Bulgaria, though to different degrees and for different reasons. Ethnic minorities' rights to preserve their culture, customs, and language are a topic of contentious debate. The purpose of this study was to examine individual- and context-level antecedents of the ethnic Bulgarian majority's support for multicultural rights of ethnic minorities. Multilevel regression analyses were conducted with International Social Survey Programme ISSP 2003 data (N = 920 in 28 Bulgarian districts). At the individual-level, an ethnic conception of the nation and anti-Roma symbolic prejudice were negatively related to support for multicultural rights, whereas national identification was positively related to the support of these rights. Over and above individual-level effects, and in line with recent extensions of intergroup contact theory, thepercentage ofBulgarianTurks withindistricts was positively related to support for multicultural rights. Importantly, support for multicultural rights was particularly high in districts characterized by ethnic diversity, that is, in districts with high proportions of both Bulgarian Turks and Roma. The beneficial effects of ethnic diversity and theoretical implications of findings are discussed

An additive subfamily of enlargements of a maximally monotone operator

We introduce a subfamily of additive enlargements of a maximally monotone operator. Our definition is inspired by the early work of Simon Fitzpatrick. These enlargements constitute a subfamily of the family of enlargements introduced by Svaiter. When the operator under consideration is the subdifferential of a convex lower semicontinuous proper function, we prove that some members of the subfamily are smaller than the classical $\epsilon$-subdifferential enlargement widely used in convex analysis. We also recover the epsilon-subdifferential within the subfamily. Since they are all additive, the enlargements in our subfamily can be seen as structurally closer to the $\epsilon$-subdifferential enlargement

Adhesion molecules in gamete transport, fertilization, early embryonic development, and implantation—role in establishing a pregnancy in cattle: A review

Cell–cell adhesion molecules have critically important roles in the early events of reproduction including gamete transport, sperm–oocyte interaction, embryonic development, and implantation. Major adhesion molecules involved in reproduction include cadherins, integrins, and disintegrin and metalloprotease domain-containing (ADAM) proteins. ADAMs on the surface of sperm adhere to integrins on the oocyte in the initial stages of sperm–oocyte interaction and fusion. Cadherins act in early embryos to organize the inner cell mass and trophectoderm. The trophoblast and uterine endometrial epithelium variously express cadherins, integrins, trophinin, and selectin, which achieve apposition and attachment between the elongating conceptus and uterine epithelium before implantation. An overview of the major cell–cell adhesion molecules is presented and this is followed by examples of how adhesion molecules help shape early reproductive events. The argument is made that a deeper understanding of adhesion molecules and reproduction will inform new strategies that improve embryo survival and increase the efficiency of natural mating and assisted breeding in cattle

Fatigue bond-slip properties of steel reinforcing bars embedded in UHPFRC: Extraction and development of an accumulated damage law

The occurrence of cyclic loads in RC structures is known to deteriorate the bond between the reinforcing bars and concrete by reducing both the bond strength and stiffness, eventually leading to debonding through large increases in slip. There is much research to quantify this bond deterioration for normal strength concrete but little research has considered UHPFRC, which is the subject of this paper. This research develops a testing approach and analysis procedure to quantify the deterioration in bond as a result of high-cycle fatigue. The procedure has been developed through 18 tests of steel reinforcing bars embedded in UHPFRC with steel micro fibres. A test rig has been developed to directly measure the bond-slip under monotonic and cyclic loads. Procedures are then developed for quantifying the bond stiffness and the incremental set, that is, the increase in slip per cycle, by using the known interaction between the monotonic and cyclic bond-slip already identified by other researchers. It is shown how these procedures can be used to quantify the bond degradation under combinations of fatigue loads and how simply measuring the crack width in a structure can give a very good indication of both the residual fatigue life and bond strength.Barbara Daniela Giorgini Sepulveda, Phillip Visintin, Deric John Oehler

Parental Support during the COVID-19 Pandemic: Friend or Foe? A Moderation Analysis of the Association between Maternal Anxiety and Children’s Stress in Italian Dyads

There is evidence that parental psychological disorders in stressful situations increase the risk of disturbance in child development. This has been investigated in disasters but not in pandemics, which are sensibly different from other types of traumatic events. We investigated the relationship between mothers’ anxiety and their children’s (self-reported) stress and the boundary conditions of this association during the first full COVID-19 lockdown in Italy. During the COVID-19 pandemic, mothers might have increased their protective attitudes to secure and support their children; we tested whether the relationship between mothers’ anxiety and children’s stress was weaker (buffer effect) or stronger (over-protection effect) when perceived parental support was high. We measured mothers’ anxiety, children’s perceived parental support, and children’s stress in a sample of 414 8- to 11-year-old primary school children (229 females, Mage = 9.44) and 395 mothers (Mage = 42.84). Results supported the over-protection scenario and provided the first evidence for the “helicopter-parent effect” during the COVID-19 pandemic: mothers’ anxiety was positively associated with children’s stress only when perceived support was high. Our finding highlights the importance of educating parents (for example, via emotional training) to prevent the worst consequences of adverse events in children and promote their mental health

Presence and distribution of the brown bear (Ursus arctos) in Friuli Venezia Giulia, from 2004 to 2011, through the non-invasive genetic monitoring ad conservation implications

After having disappeared at the beginning of 1900, the brown bear has started in a late 1960s a slow process of recolonization of the north-eastern Alps, through an expansion of Dinaric population. At the end of the 1990s the University of Udine began the occasional monitoring of the species and from 2004 non-invasive genetic monitoring became systematic. In the last 8 years 217 hair traps have been activated in the region to monitore: Natisone Valleys, the Julian and Carnic Alps and Prealps. Twenty-six hair traps were monitored in all years, whereas 40 were observed only in 2004, 2007 and 2011. The 26 hair traps constantly monitored from 2004 to 2011 showed 17% of average success of hair’s collecting (brown bear samples collected/day control: BBSD). The 40 hair traps, monitored in the window period, showed 12% of BBSD. The BBSD value varied in relation to both season (highest in spring) and year, with a dramatic decline from 2008, and interaction between year and area. From 2004, 13 genotypes, through systematic hair traps monitoring, were identified, while only 2 genotypes were sampled opportunistically. It was observed a high turnover of the genotypes: only 7 genotypes were sampled for more than 2 years (47% of total), 4 genotypes (27% of the total) were sampled for 3 years or more. The annual attendance of bear have been constant from 2004 to 2007, with 5-6 genotypes present every year. In the period between 2008 and 2010 there was a drastic decrease in the successful collection at the hair traps, with and average of 1-2 animals genotyped per year. However, opportunistic samples have increased in the recent times, probably due to the arrivals of 3 genotypes from Trentino (KJ2G2 in 2009 and DG2 and MJ4 in 2011). The year 2011 showed a further increase in the presence of bears with 5 animals genotyped in Friuli Venezia Giulia. Three of these animals belonged to the Slovenian population, while the other 2 genotypes were from the Trentino population. The results seem to confirm the exchange of some individuals between the Dinaric and central alpine population. As an example, the dinaric bear M5 was genotyped in Friuli Venezia Giulia in 2008 and then sampled in 2009 and captured in 2010 in Trentino and finally slot in Slovenia in 2011. The distribution in the alpine and prealpine areas has changed year by year: from the 2004 to 2007 the Natisone Valley and the Julian prealpine areas along the border with Slovenia were the areas more used, whilst from 2009 there was an apparent higher presence of bears in the Carnian Prealps and Alps, and in the Julian Alps. This shift could be due to human disturbance (i.e hunting management), control of the species carried out in neighbouring Slovenia, with a decreasing of immigrant from dinaric populations, and new immigration of bears from the central Alps. The present work has highlighted the necessity for a trans-regional and cross-border management of the species, especially in consideration to the population control applied in Slovenia, which seem to limit the Dinaric population expansion in the Alps, and furthermore the philopatry behaviour of bear females, which implies the absence of females in Friuli Venezia Giulia and induces a movement bach to Slovenia (at least 3 bears genotyped in Italy were shot in Slovenia). All these elements seem to exert important limitations to the consolidation and stabilization of the population of brown bears in north-eastern Alps. From the methodological point of view the protocol of systematic non-invasive genetic monitoring, shared at the trans-regional and trans-boundary level, is fundamental to monitore the dynamics and distribution of bear; the protocol should follow a systematic experimental design and should be integrated with a efficient opportunistic data collection