Ten millennia of hepatitis B virus evolution

Hepatitis B virus (HBV) has been infecting humans for millennia and remains a global health problem, but its past diversity and dispersal routes are largely unknown. We generated HBV genomic data from 137 Eurasians and Native Americans dated between ~10,500 and ~400 years ago. We date the most recent common ancestor of all HBV lineages to between ~20,000 and 12,000 years ago, with the virus present in European and South American hunter-gatherers during the early Holocene. After the European Neolithic transition, Mesolithic HBV strains were replaced by a lineage likely disseminated by early farmers that prevailed throughout western Eurasia for ~4000 years, declining around the end of the 2nd millennium BCE. The only remnant of this prehistoric HBV diversity is the rare genotype G, which appears to have reemerged during the HIV pandemic

Postoperative complications after procedure for prolapsed hemorrhoids (PPH) and stapled transanal rectal resection (STARR) procedures

Procedure for prolapsing hemorrhoids (PPH) and stapled transanal rectal resection for obstructed defecation (STARR) carry low postoperative pain, but may be followed by unusual and severe postoperative complications. This review deals with the pathogenesis, prevention and treatment of adverse events that may occasionally be life threatening. PPH and STARR carry the expected morbidity following anorectal surgery, such as bleeding, strictures and fecal incontinence. Complications that are particular to these stapled procedures are rectovaginal fistula, chronic proctalgia, total rectal obliteration, rectal wall hematoma and perforation with pelvic sepsis often requiring a diverting stoma. A higher complication rate and worse results are expected after PPH for fourth-degree piles. Enterocele and anismus are contraindications to PPH and STARR and both operations should be used with caution in patients with weak sphincters. In conclusion, complications after PPH and STARR are not infrequent and may be difficult to manage. However, if performed in selected cases by skilled specialists aware of the risks and associated diseases, some complications may be prevented

Phylogeography of the second plague pandemic revealed through analysis of historical Yersinia pestis genomes

The second plague pandemic, caused by Yersinia pestis, devastated Europe and the nearby regions between the 14th and 18th centuries AD. Here we analyse human remains from ten European archaeological sites spanning this period and reconstruct 34 ancient Y. pestis genomes. Our data support an initial entry of the bacterium through eastern Europe, the absence of genetic diversity during the Black Death, and low within-outbreak diversity thereafter. Analysis of post-Black Death genomes shows the diversification of a Y. pestis lineage into multiple genetically distinct clades that may have given rise to more than one disease reservoir in, or close to, Europe. In addition, we show the loss of a genomic region that includes virulence-related genes in strains associated with late stages of the pandemic. The deletion was also identified in genomes connected with the first plague pandemic (541–750 AD), suggesting a comparable evolutionary trajectory of Y. pestis during both events. © 2019, The Author(s)

Analysis of 3800-year-old Yersinia pestis genomes suggests Bronze Age origin for bubonic plague

The origin of Yersinia pestis and the early stages of its evolution are fundamental subjects of investigation given its high virulence and mortality that resulted from past pandemics. Although the earliest evidence of Y. pestis infections in humans has been identified in Late Neolithic/Bronze Age Eurasia (LNBA 5000-3500y BP), these strains lack key genetic components required for flea adaptation, thus making their mode of transmission and disease presentation in humans unclear. Here, we reconstruct ancient Y. pestis genomes from individuals associated with the Late Bronze Age period (~3800 BP) in the Samara region of modern-day Russia. We show clear distinctions between our new strains and the LNBA lineage, and suggest that the full ability for flea-mediated transmission causing bubonic plague evolved more than 1000 years earlier than previously suggested. Finally, we propose that several Y. pestis lineages were established during the Bronze Age, some of which persist to the present day. © 2018 The Author(s)

The Crucial Role Of Molecular Ions In The Radial Contraction Of Argon Microwave-sustained Plasma Jets At Atmospheric Pressure

Fourteen ions (Ar+, Ar2+, ArH+, H2O +, H+(H2O), H+(H2O) 2, O+, O2+, OH+, NO+, N2+, N +, Ar2+, N4+) were detected, by mass-resolved ion-energy measurements when the discharge was operated at 50 W and fluxes of 2.5 and 5.0 slm. The crucial role of three molecular ions (Ar2+, ArH+, H2O +) during the radial contraction, from diffuse (r = (750 ± 50) μm) to contracted plasma jet (r = (500 ± 50) μm), and the relationship between power, gas flow and molecular ions production were pointed out. Ion energy distributions for Ar2+, ArH+ and H2O + exhibit their maxima at high-energies due to low-energy threshold for three-body collision reactions. © 2014 Elsevier B.V. All rights reserved.595-5968386Moisan, M., Zakrzewski, Z., (1991) J. Phys. D Appl. Phys., 24, p. 1025Jankowski, K., Reszke, E., (2013) J. Anal. At. Spectrom., 28, p. 1196Kudela, J., Odrobina, I., Kando, M., (1998) Jpn. J. Appl. Phys., 37, p. 4169Cahng, J.-S., (2001) Sci. Technol. Adv. Mater., 2, p. 571Levaton, J., Ricard, A., Henriques, J., Silva, H.R.T., Amorim, J., (2006) J. Phys. D Appl. Phys., 39, p. 3285Purevdorj, D., Igura, N., Ariyada, O., Hayakawa, I., (2002) Lett. Appl. Microbiol., 37, p. 1008Golubovskii, Y.B., Nekuchaev, V., Gorchakov, S., Uhrlandt, D., (2011) Plasma Sources Sci. Technol., 20, p. 053002Kenty, C., (1962) Phys. Rev. e, 126, p. 1235Massey, J.T., (1965) J. Appl. Phys., 36, p. 373Kabouzi, Y., Calzada, M.D., Moisan, M., Tran, K.C., Trassy, C., (1965) J. Appl. Phys., 91, p. 361Varey, R.H., Smalley, J., Richards, P.H., Gozna, C.F., Swift-Hook, D.T., (1971) J. Phys. D Appl. Phys., 4, p. 1520Daniels, P.G., Franklin, R.N., Snell, J., (1990) J. Phys. D Appl. Phys., 23, p. 823Yu Baranov, V., Ul'Yanov, K.N., (1969) Sov. Phys. Tech. Phys., 14, p. 176Golubovskii, Y.B., Sonneburg, R., (1979) Sov. Phys. Tech. Phys., 24, p. 173Golubovskii, Y.B., Sonneburg, R., (1979) Sov. Phys. Tech. Phys., 24, p. 177Golubovskii, Yu.B., Lange, H., Maiorov, V.A., Porokhova, I.A., Sushkov, V.P., (2003) J Phys. D, 36, p. 694Petrov, G.M., Ferreira, C.M., (1999) Phys. Rev. e, 59, p. 3571Castanos-Martínez, E., Moisan, M., (2011) IEEE Trans. Plasma Sci., 39, p. 2192Lukác, P., Mikus, O., Morva, I., Zábudlá, J., Trnovec, Z., Morvová, M., (2011) Plasma Sources Sci. Technol., 20, p. 055012Castanos-Martínez, E., Moisan, M., Kabouzi, Y., (2009) J. Phys. D Appl. Phys., 42, p. 012003Ridenti, M.A., Souza-Corrêa, J.A., Amorim, J., (2014) J. Phys. D Appl. Phys., 47, p. 045204Benedikt, J., Hecimovic, A., Ellerweg, D., Von Keudell, A., (2012) J. Phys. D Appl. Phys., 45, p. 403001Bruggeman, P., Iza, F., Lauwers, D., Gonzalvo, Y.A., (2010) J. Phys. D Appl. Phys, 43, p. 012003Hamers, E.A.G., Van Sark, W.G.J.H.M., Bezemer, J., Goeddheer, W.J., Van De Weg, W.F., (2010) Int. J. Mass Spectrom. Ion Process., 43, p. 012003Lukác, P., Mikus, O., Morva, I., Zábudlá, Z., Trnovec, J., Morvová, M., (2011) Plasma Sources Sci. Technol., 20, p. 055012Massey, J.T., Cannon, S.M., (1965) J. Appl. Phys., 36, p. 361Castanos-Martínez, E., Kabouzi, Y., Makasheva, K., Moisan, M., (2004) Phys. Rev. e, 70, p. 066405Amorim, J., Oliveira, C., Souza-Corrêa, J.A., Ridenti, M.A., (2013) Plasma Process. Polym., 10, p. 670Bundaleska, N., Tatarova, E., Dias, F.M., Lino Da Silva, M., Ferreira, C.M., Amorim, J., (2014) J. Phys. D Appl. Phys., 47, p. 05520

Early contact between late farming and pastoralist societies in southeastern Europe

Archaeogenetic studies have described two main genetic turnover events in prehistoric western Eurasia: one associated with the spread of farming and a sedentary lifestyle starting around 7000-6000 BC (refs. 1-3) and a second with the expansion of pastoralist groups from the Eurasian steppes starting around 3300 BC (refs. 4,5). The period between these events saw new economies emerging on the basis of key innovations, including metallurgy, wheel and wagon and horse domestication6-9. However, what happened between the demise of the Copper Age settlements around 4250 BC and the expansion of pastoralists remains poorly understood. To address this question, we analysed genome-wide data from 135 ancient individuals from the contact zone between southeastern Europe and the northwestern Black Sea region spanning this critical time period. While we observe genetic continuity between Neolithic and Copper Age groups from major sites in the same region, from around 4500 BC on, groups from the northwestern Black Sea region carried varying amounts of mixed ancestries derived from Copper Age groups and those from the forest/steppe zones, indicating genetic and cultural contact over a period of around 1,000 years earlier than anticipated. We propose that the transfer of critical innovations between farmers and transitional foragers/herders from different ecogeographic zones during this early contact was integral to the formation, rise and expansion of pastoralist groups around 3300 BC.Sandra Penske, Adam B. Rohrlach, Ainash Childebayeva, Guido Gnecchi-Ruscone, Clemens Schmid, Maria A. Spyrou, Gunnar U. Neumann, Nadezhda Atanassova, Katrin Beutler, Kamen Boyadzhiev, Yavor Boyadzhiev, Igor Bruyako, Alexander Chohadzhiev, Blagoje Govedarica, Mehmet Karaucak, Raiko Krauss, Maleen Leppek, Igor Manzura, Karen Privat, Shawn Ross, Vladimir Slavchev, Adéla Sobotkova, Meda Toderaş, Todor Valchev, Harald Ringbauer, Philipp W. Stockhammer, Svend Hansen, Johannes Krause & Wolfgang Haa

Optimisation of energy absorbing liner for equestrian helmets. Part I: Layered foam liner

The energy absorbing foam liner used in safety helmets was optimised using finite element modelling. Computational simulations of certification standard tests were carried out to obtain the best performing configurations of helmet liner. For each test condition, the best configuration of helmet liner was identified. Two alternative designs were considered: the first was composed of three layers of different foam density, the second was a conventional liner of one single uniform density. The observed reduction in peak acceleration for the best performing helmet liners in various test conditions are directly related to the contact area, the distribution of material stresses and the dissipated plastic energy density (DPED). Peak linear accelerations are shown to be lowered by increasing the contact areas of the inner and outer surfaces of the energy absorbing liner, or by varying the foam density through the thickness of the liner to ensure that the foam absorbs energy plastically when the stress reaches the late plateau stage of the foam stress–strain curve.Deposited by bulk importAM