Entrance-channel Mass-asymmetry Dependence of Compound-nucleus Formation Time in Light Heavy-ion Reactions

The entrance-channel mass-asymmetry dependence of the compound nucleus formation time in light heavy-ion reactions has been investigated within the framework of semiclassical dissipative collision models. the model calculations have been succesfully applied to the formation of the $^{38}$Ar compound nucleus as populated via the $^{9}$Be+$^{29}$Si, $^{11}$B+$^{27}$Al, $^{12}$C+$^{26}$Mg and $^{19}$F+$^{19}$F entrance channels. The shape evolution of several other light composite systems appears to be consistent with the so-called "Fusion Inhibition Factor" which has been experimentally observed. As found previously in more massive systems for the fusion-evaporation process, the entrance-channel mass-asymmetry degree of freedom appears to determine the competition between the different mechanisms as well as the time scales involved.Comment: 12 pages, 3 Figures available upon request, Submitted at Phys. Rev.

Heavy-ion resonance and statistical fission competition in the Mg24+24Mg system at Ec.m.=44.4 MeV

The fully energy-damped cross sections of the Mg24+24Mg reaction at Ec.m.=44.4 MeV have been measured for all of the major fission channels. High-resolution Q-value spectra have been obtained for the large-angle yields in the Mg24+24Mg and Ne20+28Si channels. Calculations based on the transition-state model are found to reproduce the fully damped cross sections in all of the observed mass channels. The pronounced structure that is observed in the excitation-energy spectra for the more symmetric mass channels, even for the strongly damped yields, is shown to be qualitatively reproduced by assuming a spin-weighted population of the fragment states. There is no evidence, however, that the structure of the nascent fission fragments at scission may influence the population of states in the fragments. These results, taken together with earlier measurements of the resonance behavior of this system, suggest the coexistence of fission from the normal, compact compound nucleus with that from the deformed configurations believed to be responsible for the resonance behavior

Influence of highway 3D coordination on drivers' perception of horizontal curvature and available sight distance

"This paper is a preprint of a paper submitted to [journal] and is subject to Institution of Engineering and Technology Copyright. If accepted, the copy of record will be available at IET Digital Library"Drivers' road perception is an important human factor of comfort and safety on driving. Available sight distance of crest vertical curves superimposed on horizontal curves can be geometrically optimised by applying 3D coordination criteria. However, drivers might not perceive available sight distance improvements. Two approaches were used to investigate the effect of geometrical optimised design on perceived sharpness and visibility of isolated crest vertical curves overlapped with horizontal curves. A survey-based approach was used to evaluate subjective perception of 100 drivers. Three-dimensional renderings were displayed to subjects; who were asked to rank the curves by sharpness and sight distance. Moreover, 50 of those drivers previously participated on a driving simulation experiment involving the same curves, so objective driving data were collected too. Drivers' survey results indicate that driver's curve perception depends on the algebraic difference of grades while coordination of vertical and horizontal curves does not appear to affect this perception. On the other hand, the operating speeds on different curves were not statistically different from each other. Surprisingly, the operating speeds on a flat curve tended to be lower than on the vertical crest curves superimposed on the same horizontal curve. Likely causes are discussed in the paper.Moreno Chou, AT.; García García, A.; Camacho Torregrosa, FJ.; Llorca Garcia, C. (2013). Influence of highway 3D coordination on drivers' perception of horizontal curvature and available sight distance. IET Intelligent Transport Systems. 7(2):244-250. doi:10.1049/iet-its.2012.0146S24425072Hassan, Y., & Easa, S. M. (2000). Modeling of Required Preview Sight Distance. Journal of Transportation Engineering, 126(1), 13-20. doi:10.1061/(asce)0733-947x(2000)126:1(13)García, A. (2004). Discussion of «Optimal Vertical Alignment Analysis for Highway Design» by T. F. Fwa, W. T. Chan, and Y. P. Sim. Journal of Transportation Engineering, 130(1), 138-138. doi:10.1061/(asce)0733-947x(2004)130:1(138)Bidulka, S., Sayed, T., & Hassan, Y. (2002). Influence of Vertical Alignment on Horizontal Curve Perception: Phase I: Examining the Hypothesis. Transportation Research Record: Journal of the Transportation Research Board, 1796(1), 12-23. doi:10.3141/1796-02Hassan, Y., Sayed, T., & Bidulka, S. (2002). Influence of Vertical Alignment on Horizontal Curve Perception: Phase II: Modeling Perceived Radius. Transportation Research Record: Journal of the Transportation Research Board, 1796(1), 24-34. doi:10.3141/1796-03Hasan, M., Sayed, T., & Hassan, Y. (2005). Influence of vertical alignment on horizontal curve perception: effect of spirals and position of vertical curve. Canadian Journal of Civil Engineering, 32(1), 204-212. doi:10.1139/l04-090Wang, F., & Easa, S. M. (2009). Validation of Perspective-View Concept for Estimating Road Horizontal Curvature. Journal of Transportation Engineering, 135(2), 74-80. doi:10.1061/(asce)0733-947x(2009)135:2(74)Bella, F. (2007). Parameters for Evaluation of Speed Differential. Transportation Research Record: Journal of the Transportation Research Board, 2023(1), 37-43. doi:10.3141/2023-05Ben-Bassat, T., & Shinar, D. (2011). Effect of shoulder width, guardrail and roadway geometry on driver perception and behavior. Accident Analysis & Prevention, 43(6), 2142-2152. doi:10.1016/j.aap.2011.06.004Jia, L., Wang, J., & Lu, M. (2011). Using real-world data to calibrate a driving simulator measuring lateral driving behaviour. IET Intelligent Transport Systems, 5(1), 21-31. doi:10.1049/iet-its.2009.0094Antonson, H., Mårdh, S., Wiklund, M., & Blomqvist, G. (2009). Effect of surrounding landscape on driving behaviour: A driving simulator study. Journal of Environmental Psychology, 29(4), 493-502. doi:10.1016/j.jenvp.2009.03.005Land, M. F., & Lee, D. N. (1994). Where we look when we steer. Nature, 369(6483), 742-744. doi:10.1038/369742a0Zuriaga, A. M. P., García, A. G., Torregrosa, F. J. C., & D’Attoma, P. (2010). Modeling Operating Speed and Deceleration on Two-Lane Rural Roads with Global Positioning System Data. Transportation Research Record: Journal of the Transportation Research Board, 2171(1), 11-20. doi:10.3141/2171-02Kweon, B.-S., Ellis, C. D., Lee, S.-W., & Rogers, G. O. (2006). Large-Scale Environmental Knowledge. Environment and Behavior, 38(1), 72-91. doi:10.1177/001391650528009

Formation and Evolution of Supermassive Black Holes

The correlation between the mass of supermassive black holes in galaxy nuclei and the mass of the galaxy spheroids or bulges (or more precisely their central velocity dispersion), suggests a common formation scenario for galaxies and their central black holes. The growth of bulges and black holes can commonly proceed through external gas accretion or hierarchical mergers, and are both related to starbursts. Internal dynamical processes control and regulate the rate of mass accretion. Self-regulation and feedback are the key of the correlation. It is possible that the growth of one component, either BH or bulge, takes over, breaking the correlation, as in Narrow Line Seyfert 1 objects. The formation of supermassive black holes can begin early in the universe, from the collapse of Population III, and then through gas accretion. The active black holes can then play a significant role in the re-ionization of the universe. The nuclear activity is now frequently invoked as a feedback to star formation in galaxies, and even more spectacularly in cooling flows. The growth of SMBH is certainly there self-regulated. SMBHs perturb their local environment, and the mergers of binary SMBHs help to heat and destroy central stellar cusps. The interpretation of the X-ray background yields important constraints on the history of AGN activity and obscuration, and the census of AGN at low and at high redshifts reveals the downsizing effect, already observed for star formation. History appears quite different for bright QSO and low-luminosity AGN: the first grow rapidly at high z, and their number density decreases then sharply, while the density of low-luminosity objects peaks more recently, and then decreases smoothly.Comment: 31 pages, 13 figures, review paper for Astrophysics Update

Fusion and Binary-Decay Mechanisms in the 35^{35}Cl+24^{24}Mg System at E/A ≈\approx 8 MeV/Nucleon

Compound-nucleus fusion and binary-reaction mechanisms have been investigated for the $^{35}$Cl+$^{24}$Mg system at an incident beam energy of E$_{Lab}$= 282 MeV. Charge distributions, inclusive energy spectra, and angular distributions have been obtained for the evaporation residues and the binary fragments. Angle-integrated cross sections have been determined for evaporation residues from both the complete and incomplete fusion mechanisms. Energy spectra for binary fragment channels near to the entrance-channel mass partition are characterized by an inelastic contribution that is in addition to a fully energy damped component. The fully damped component which is observed in all the binary mass channels can be associated with decay times that are comparable to, or longer than the rotation period. The observed mass-dependent cross sections for the fully damped component are well reproduced by the fission transition-state model, suggesting a fusion followed by fission origin. The present data cannot, however, rule out the possibility that a long-lived orbiting mechanism accounts for part or all of this yield.Comment: 41 pages standard REVTeX file, 14 Figures available upon request -

The burden of unintentional drowning: Global, regional and national estimates of mortality from the Global Burden of Disease 2017 Study

__Background:__ Drowning is a leading cause of injury-related mortality globally. Unintentional drowning (International Classification of Diseases (ICD) 10 codes W65-74 and ICD9 E910) is one of the 30 mutually exclusive and collectively exhaustive causes of injury-related mortality in the Global Burden of Disease (GBD) study. This study's objective is to describe unintentional drowning using GBD estimates from 1990 to 2017. __Methods:__ Unintentional drowning from GBD 2017 was estimated for cause-specific mortality and years of life lost (YLLs), age, sex, country, region, Socio-demographic Index (SDI) quintile, and trends from 1990 to 2017. GBD 2017 used standard GBD methods for estimating mortality from drowning. __Results:__ Globally, unintentional drowning mortality decreased by 44.5% between 1990 and 2017, from 531 956 (uncertainty interval (UI): 484 107 to 572 854) to 295 210 (284 493 to 306 187) deaths. Global age-standardised mortality rates decreased 57.4%, from 9.3 (8.5 to 10.0) in 1990 to 4.0 (3.8 to 4.1) per 100 000 per annum in 2017. Unintentional drowning-associated mortality was generally higher in children, males and in low-SDI to middle-SDI countries. China, India, Pakistan and Bangladesh accounted for 51.2% of all drowning deaths in 2017. Oceania was the region with the highest rate of age-standardised YLLs in 2017, with 45 434 (40 850 to 50 539) YLLs per 100 000 across both sexes. __Conclusions:__ There has been a decline in global drowning rates. This study shows that the decline was not consistent across countries. The results reinforce the need for continued and improved policy, prevention and research efforts, with a focus on low-and middle-income countries

Mapping geographical inequalities in childhood diarrhoeal morbidity and mortality in low-income and middle-income countries, 2000–17 : analysis for the Global Burden of Disease Study 2017

Background Across low-income and middle-income countries (LMICs), one in ten deaths in children younger than 5 years is attributable to diarrhoea. The substantial between-country variation in both diarrhoea incidence and mortality is attributable to interventions that protect children, prevent infection, and treat disease. Identifying subnational regions with the highest burden and mapping associated risk factors can aid in reducing preventable childhood diarrhoea. Methods We used Bayesian model-based geostatistics and a geolocated dataset comprising 15 072 746 children younger than 5 years from 466 surveys in 94 LMICs, in combination with findings of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, to estimate posterior distributions of diarrhoea prevalence, incidence, and mortality from 2000 to 2017. From these data, we estimated the burden of diarrhoea at varying subnational levels (termed units) by spatially aggregating draws, and we investigated the drivers of subnational patterns by creating aggregated risk factor estimates. Findings The greatest declines in diarrhoeal mortality were seen in south and southeast Asia and South America, where 54·0% (95% uncertainty interval [UI] 38·1–65·8), 17·4% (7·7–28·4), and 59·5% (34·2–86·9) of units, respectively, recorded decreases in deaths from diarrhoea greater than 10%. Although children in much of Africa remain at high risk of death due to diarrhoea, regions with the most deaths were outside Africa, with the highest mortality units located in Pakistan. Indonesia showed the greatest within-country geographical inequality; some regions had mortality rates nearly four times the average country rate. Reductions in mortality were correlated to improvements in water, sanitation, and hygiene (WASH) or reductions in child growth failure (CGF). Similarly, most high-risk areas had poor WASH, high CGF, or low oral rehydration therapy coverage. Interpretation By co-analysing geospatial trends in diarrhoeal burden and its key risk factors, we could assess candidate drivers of subnational death reduction. Further, by doing a counterfactual analysis of the remaining disease burden using key risk factors, we identified potential intervention strategies for vulnerable populations. In view of the demands for limited resources in LMICs, accurately quantifying the burden of diarrhoea and its drivers is important for precision public health

Anemia prevalence in women of reproductive age in low- and middle-income countries between 2000 and 2018

Anemia is a globally widespread condition in women and is associated with reduced economic productivity and increased mortality worldwide. Here we map annual 2000–2018 geospatial estimates of anemia prevalence in women of reproductive age (15–49 years) across 82 low- and middle-income countries (LMICs), stratify anemia by severity and aggregate results to policy-relevant administrative and national levels. Additionally, we provide subnational disparity analyses to provide a comprehensive overview of anemia prevalence inequalities within these countries and predict progress toward the World Health Organization’s Global Nutrition Target (WHO GNT) to reduce anemia by half by 2030. Our results demonstrate widespread moderate improvements in overall anemia prevalence but identify only three LMICs with a high probability of achieving the WHO GNT by 2030 at a national scale, and no LMIC is expected to achieve the target in all their subnational administrative units. Our maps show where large within-country disparities occur, as well as areas likely to fall short of the WHO GNT, offering precision public health tools so that adequate resource allocation and subsequent interventions can be targeted to the most vulnerable populations.Peer reviewe