Chandra Observation of the Merging Cluster A168: A Late Stage in the Evolution of a Cold Front

We present Chandra observations of the cool cluster A168, for which previous X-ray imaging and optical studies indicated a merger of two subclusters nearly in the plane of the sky. We derive a temperature map for A168, which shows that the merger has proceeded beyond the core passage and is near subcluster turnaround. It also reveals an unusual feature -- the gas core of one of the subclusters forms a tongue-like structure extending ahead (in the direction of motion) of the subcluster center. The coolest cluster gas is found in a crescent-shaped region at the tip of this tongue, and forms a cold front in pressure equilibrium with the external gas. In contrast with this feature's forward location, previously observed merger cold fronts (e.g., A3667, 1E0657--56) lagged behind their host subclusters, as expected in the presense of ram pressure. We propose that A168 illustrates a much later stage in the evolution of a cold front, when its host subcluster approaches the apocenter of the merger orbit where the ram pressure on its gas drops sharply. As a result, a large chunk of the subcluster gas ``slingshots'' past the dark matter center, becomes unbound from the subcluster and expands adiabatically, as seen in some recent hydrodynamic simulations.Comment: 4 pages, 3 figures, to be published in ApJ Letter

Probabilistic Records Linkage using Historical Canadian Censuses and Vital Statistics

Poster Presentation This poster presents the results of a records linkage project to analyze potential mortality risks for young adults in Ontario during the 1918 influenza epidemic. With a team of research assistants at Western University, McMaster University, and the Université de Montréal, death records were linked to birth records in order to determine exact date of birth for the calculation of exact age at death. This date of birth is then compared to age as listed on other historical documents, such as the 1901 and 1911 Canadian censuses. The family environment (or living situation) was transcribed for each individual at each census to examine the impact of socioeconomic conditions throughout the lifecourse on mortality in 1918. Of the 23,183 deaths registered in Ontario between September and December 1918 and transcribed by the International Infectious Disease Data Archive at McMaster University, 3,316 individuals met the inclusion criteria. Both birth and death must have occurred in Ontario to establish exact date of birth and the individual must have died between the ages of 23 and 35 (born between 1883 and 1895). Of the 3,316 included death records, 2,965 were linked to at least one other record, giving a linkage success rate of 89.4%. This poster analyzes the linkage rates of the death records to birth records from 1883-1895 and the 1901 and 1911 Canadian censuses and uses logistic regression to investigate the important factors that precluded linkage. It evaluates declared age at all three time periods to discuss the suitability of these records for historical demographic analyses of past epidemic disease

The Demographic Links Between the 1890 and 1918 Influenza Pandemics in Ontario

Previous research has shown larger than expected numbers of deaths at the age of 28 during the 1918 Spanish influenza pandemic in Canada. To analyze whether this was related to the Russian influenza pandemic that occurred 28 years previously in 1890, the Western, McMaster, Montreal Influenza Pandemic (WMMIP) database was created. It utilizes the death records of 3,316 individuals who died in Ontario between the ages of 23 and 35 from September to December, 1918, and who were also born in Ontario. These were linked to birth records, the 1901 and 1911 Canadian censuses, marriage records, and attestation papers. A reconstructed date of birth was created for each individual to analyze date of potential exposure in 1890. Those who were in utero in 1890 died in greater numbers than would be expected and those in the first trimester of gestation had an unusual sex-ratio at death. Of the various hypotheses proposed to account for the high young adult mortality, these data most closely support that of antigenic imprinting. There is cautious support for the fetal growth restrictions hypothesis, but these data do not support the scarring mechanism. Further, these data do not support the hypothesized relationship between tuberculosis infection and influenza mortality. More individuals left agricultural homes of origin among the decedents than among the Ontario population in general. There were proportionally more French Canadians, more catholic individuals, and more people from Eastern Ontario. The decedents also came from larger families than were found in the general population, although this may be an artifact of the records linkage process. This research shows that the mortality pattern in Ontario during the pandemic was similar to what it was prior to the epidemic: mortality continued along the fault lines in society and did not equalize risk in a “democratic” manner. The extant records are appropriate for historical demographic analyses and the strength and weaknesses for each are detailed. As expected, individuals from the north, who were aboriginal, from smaller families, or in transient occupations were harder to link

Unified Band Theoretic Description of Electronic and Magnetic Properties of Vanadium Dioxide Phases

The debate about whether the insulating phases of vanadium dioxide (VO2) can be described by band theory or must be described by a theory of strong electron correlations remains unresolved even after decades of research. Energy-band calculations using hybrid exchange functionals or including self-energy corrections account for the insulating or metallic nature of different phases, but have not yet successfully accounted for the observed magnetic orderings. Strongly-correlated theories have had limited quantitative success. Here we report that, by using hard pseudopotentials and an optimized hybrid exchange functional, the energy gaps and magnetic orderings of both monoclinic VO2 phases and the metallic nature of the high-temperature rutile phase are consistent with available experimental data, obviating an explicit role for strong correlations. We also report a potential candidate for the newly-found metallic monoclinic phase and present a detailed magnetic structure of the M2 monoclinic phase

Age-specific mortality during the 1918 influenza pandemic: unravelling the mystery of high young adult mortality.

The worldwide spread of a novel influenza A (H1N1) virus in 2009 showed that influenza remains a significant health threat, even for individuals in the prime of life. This paper focuses on the unusually high young adult mortality observed during the Spanish flu pandemic of 1918. Using historical records from Canada and the U.S., we report a peak of mortality at the exact age of 28 during the pandemic and argue that this increased mortality resulted from an early life exposure to influenza during the previous Russian flu pandemic of 1889-90. We posit that in specific instances, development of immunological memory to an influenza virus strain in early life may lead to a dysregulated immune response to antigenically novel strains encountered in later life, thereby increasing the risk of death. Exposure during critical periods of development could also create holes in the T cell repertoire and impair fetal maturation in general, thereby increasing mortality from infectious diseases later in life. Knowledge of the age-pattern of susceptibility to mortality from influenza could improve crisis management during future influenza pandemics

Tracking the Impact of Diseases of Despair in Appalachia—2015 to 2018

Introduction: This study provides an update on mortality due to diseases of despair within the Appalachian Region, comparing 2015 to 2018. Methods: Diseases of despair include: alcohol, prescription drug and illegal drug overdose, suicide, and alcoholic liver disease/cirrhosis of the liver. Analyses are based on National Vital Statistics System (NVSS) mortality data for individuals aged 15-64. Results: Between 2015 and 2017, the diseases of despair mortality rate increased in both Appalachia and the non-Appalachian U.S., and the disparity grew between Appalachia and the rest of the county. In 2018, the disease of despair mortality rate declined by 8 percent in Appalachia, marking the first decline for the Region since 2012. Diseases of despair continue to impact the working-age population, and while males experience a higher burden of mortality due to diseases of despair, the disparity between Appalachia and the rest of the United States is greater for females. Overdose mortality rates in Appalachia increased between 2015 and 2017, followed by a decline in 2018. During this same time frame, suicide also increased notably within the Appalachian region, and the disparity between Appalachia and the non-Appalachian U.S. increased by 50 percent. Implications: These findings document that the diseases of despair continue to have a greater impact in the Appalachian Region than in the rest of the United States. While the declining trends between 2017 and 2018 are promising, data has shown that these rates are likely to increase again, particularly as a result of the COVID-19 pandemic

Post-harvest entomology research in the United States Department of Agriculture–Agricultural Research Service

This is a review of current post-harvest entomology research conducted by the Agricultural Research Service, the research branch of the US Department of Agriculture. The review covers both durable and perishable commodities. Research on biochemistry, genetics, physiology, monitoring and control of insects infesting stored grain, dried fruits and nuts, and processed commodities is reviewed. Research on development of quarantine treatments, particularly for fruit flies, is also reviewed, including research on thermal and irradiation treatments and a discussion of risk management for quarantine pests. Two areas of research are covered more extensively: a project to map the genome of the red flour beetle, Tribolium castaneum, and the use of near-infrared spectroscopy for detection of hidden infestations in grain, quantification of insect fragments in food, determination of quality in dried fruits, identification of insect species and age-grading insects. Future research directions are identified

The Santa Fe Light Cone Simulation Project: I. Confusion and the WHIM in Upcoming Sunyaev-Zel'dovich Effect Surveys

We present the first results from a new generation of simulated large sky coverage (~100 square degrees) Sunyaev-Zeldovich effect (SZE) cluster surveys using the cosmological adaptive mesh refinement N-body/hydro code Enzo. We have simulated a very large (512^3h^{-3}Mpc^3) volume with unprecedented dynamic range. We have generated simulated light cones to match the resolution and sensitivity of current and future SZE instruments. Unlike many previous studies of this type, our simulation includes unbound gas, where an appreciable fraction of the baryons in the universe reside. We have found that cluster line-of-sight overlap may be a significant issue in upcoming single-dish SZE surveys. Smaller beam surveys (~1 arcmin) have more than one massive cluster within a beam diameter 5-10% of the time, and a larger beam experiment like Planck has multiple clusters per beam 60% of the time. We explore the contribution of unresolved halos and unbound gas to the SZE signature at the maximum decrement. We find that there is a contribution from gas outside clusters of ~16% per object on average for upcoming surveys. This adds both bias and scatter to the deduced value of the integrated SZE, adding difficulty in accurately calibrating a cluster Y-M relationship. Finally, we find that in images where objects with M > 5x10^{13} M_{\odot} have had their SZE signatures removed, roughly a third of the total SZE flux still remains. This gas exists at least partially in the Warm Hot Intergalactic Medium (WHIM), and will possibly be detectable with the upcoming generation of SZE surveys.Comment: 14 pages, 13 figures, version accepted to ApJ. Major revisions mad

Post-harvest entomology research in the United States Department of Agriculture–Agricultural Research Service

This is a review of current post-harvest entomology research conducted by the Agricultural Research Service, the research branch of the US Department of Agriculture. The review covers both durable and perishable commodities. Research on biochemistry, genetics, physiology, monitoring and control of insects infesting stored grain, dried fruits and nuts, and processed commodities is reviewed. Research on development of quarantine treatments, particularly for fruit flies, is also reviewed, including research on thermal and irradiation treatments and a discussion of risk management for quarantine pests. Two areas of research are covered more extensively: a project to map the genome of the red flour beetle, Tribolium castaneum, and the use of near-infrared spectroscopy for detection of hidden infestations in grain, quantification of insect fragments in food, determination of quality in dried fruits, identification of insect species and age-grading insects. Future research directions are identified