Abstract
Background
Tuberculosis (TB) natural history remains poorly characterized, and new investigations are impossible as it would be unethical to follow up TB patients without treatment.
Methods
...We considered the reports identified in a previous systematic review of studies from the prechemotherapy era, and extracted detailed data on mortality over time. We used a Bayesian framework to estimate the rates of TB-induced mortality and self-cure. A hierarchical model was employed to allow estimates to vary by cohort. Inference was performed separately for smear-positive TB (SP-TB) and smear-negative TB (SN-TB).
Results
We included 41 cohorts of SP-TB patients and 19 cohorts of pulmonary SN-TB patients in the analysis. The median estimates of the TB-specific mortality rates were 0.389 year−1 (95% credible interval CrI, .335–.449) and 0.025 year−1 (95% CrI, .017–.035) for SP-TB and SN-TB patients, respectively. The estimates for self-recovery rates were 0.231 year−1 (95% CrI, .177–.288) and 0.130 year−1 (95% CrI, .073–.209) for SP-TB and SN-TB patients, respectively. These rates correspond to average durations of untreated TB of 1.57 years (95% CrI, 1.37–1.81) and 5.35 years (95% CrI, 3.42–8.23) for SP-TB and SN-TB, respectively, when assuming a non-TB-related mortality rate of 0.014 year−1 (ie, a 70-year life expectancy).
Conclusions
TB-specific mortality rates are around 15 times higher for SP-TB than for SN-TB patients. This difference was underestimated dramatically in previous TB modeling studies, raising concerns about the accuracy of the associated predictions. Despite being less infectious, SN-TB may be responsible for equivalent numbers of secondary infections as SP-TB due to its much longer duration.
A wide-ranging treatment on the meaning of death, and its juxtaposition with life, from biological, cultural, and spiritual perspectives. Dozens of case studies accompany the principal essays written ...by scholars, Indigenous community members, and curators of the exhibition Death: Life’s Greatest Mystery. This volume offers a richly illustrated companion to the exhibition, produced by Chicago’s Field Museum of Natural History, and contains full page photographs of the stunning objects in the exhibit, most from the Field Museum’s collections. This volume is intended to engage visitors to the exhibition and members of the general public who want to delve more fully into questions surrounding death and the multiple religious, historical, and cultural perspectives on it. Although not a comprehensive guide, the book touches on many world religions and case studies drawn from five continents.
In Hunting Nature, Thomas P. Hodge explores Ivan Turgenev's relationship to nature through his conception, description, and practice of hunting—the most unquenchable passion of his life. Informed by ...an ecocritical perspective, Hodge takes an approach that is equal parts interpretive and documentarian, grounding his observations thoroughly in Russian cultural and linguistic context and a wide range of Turgenev's fiction, poetry, correspondence, and other writings. Included within the book are some of Turgenev's important writings on nature—never previously translated into English. Turgenev, who is traditionally identified as a chronicler of Russia's ideological struggles, is presented in Hunting Nature as an expert naturalist whose intimate knowledge of flora and fauna deeply informed his view of philosophy, politics, and the role of literature in society. Ultimately, Hodge argues that we stand to learn a great deal about Turgenev's thought and complex literary technique when we read him in both cultural and environmental contexts. Hodge details how Turgenev remains mindful of the way textual detail is wedded to the organic world—the priroda that he observed, and ached for, more keenly than perhaps any other Russian writer.
Telling Time With Mammoths Rebecca Woods
Journal for the history of knowledge,
11/2023, Letnik:
4
Journal Article
Recenzirano
Odprti dostop
Until recent decades, permafrost-preserved frozen mammoths were among the rarest of scientific specimens: only one was successfully collected between 1806 and 1902. With global warming and increased ...industrial activity in the circumpolar north, in the twenty-first century discovering these creatures has become a seasonal phenomenon. This article traces this broad trajectory, examining how distinct temporalities—planetary, industrial, and Indigenous—intersect and inform distinct frozen mammoths that surfaced over the last 223 years. Told in four acts, the article considers how frozen mammoths tell time, informing debates over the planet’s past, present, and possible futures according to the moment into which they emerged. Frozen mammoths function as material loci for time and temperature, enabled by the cold of the circumpolar region, and enabling multi-temporal epistemologies to take shape around their remains.
 Coupled with geological and geographical history, climatic oscillations during the Pleistocene period had remarkable effects on species biodiversity and distribution along the northwestern ...Pacific. To detect the population structure and demographic history of Odontamblyopus lacepedii , 547-bp fragments of the mitochondrial DNA control region were sequenced. A low level of nucleotide diversity (0.0065 ± 0.0037) and a high level of haplotype diversity (0.98 ± 0.01) was observed. The Maximum Likelihood (ML) and Bayesian Inference phylogenetic trees showed no significant genealogical structure corresponding to sampling locations. The results of AMOVA and pairwise F sub.ST values revealed some significant genetic differentiation among populations, and the isolation by distance (IBD) analysis supported that the genetic differentiation was associated with the geographic distances. The demographic history of O. lacepedii examined by neutrality tests, mismatch distribution analysis, and Bayesian Skyline Plots (BSP) analysis suggested a sudden population expansion, and the expansion time was estimated to be around the Pleistocene. We hypothesize that the climate changes during the Pleistocene, ocean currents, and larval dispersal capabilities have played an important role in shaping contemporary phylogeographic pattern and population structure of O. lacepedii . Keywords: Conservation, control region, fishery management, genetic diversity, genetic structure, Odontamblyopus lacepedii , population demography
Retroviruses infect a broad range of vertebrate hosts that includes amphibians, reptiles, fish, birds and mammals. In addition, a typical vertebrate genome contains thousands of loci composed of ...ancient retroviral sequences known as endogenous retroviruses (ERVs). ERVs are molecular remnants of ancient retroviruses and proof that the ongoing relationship between retroviruses and their vertebrate hosts began hundreds of millions of years ago. The long-term impact of retroviruses on vertebrate evolution is twofold: first, as with other viruses, retroviruses act as agents of selection, driving the evolution of host genes that block viral infection or that mitigate pathogenesis, and second, through the phenomenon of endogenization, retroviruses contribute an abundance of genetic novelty to host genomes, including unique protein-coding genes and cis-acting regulatory elements. This Review describes ERV origins, their diversity and their relationships to retroviruses and discusses the potential for ERVs to reveal virus-host interactions on evolutionary timescales. It also describes some of the many examples of cellular functions, including protein-coding genes and regulatory elements, that have evolved from ERVs.
The great therapeutic achievements of antibiotics have been dramatically undercut by the evolution of bacterial strategies that overcome antibiotic stress. These strategies fall into two classes. ...'Resistance' makes it possible for a microorganism to grow in the constant presence of the antibiotic, provided that the concentration of the antibiotic is not too high. 'Tolerance' allows a microorganism to survive antibiotic treatment, even at high antibiotic concentrations, as long as the duration of the treatment is limited. Although both resistance and tolerance are important reasons for the failure of antibiotic treatments, the evolution of resistance is much better understood than that of tolerance. Here we followed the evolution of bacterial populations under intermittent exposure to the high concentrations of antibiotics used in the clinic and characterized the evolved strains in terms of both resistance and tolerance. We found that all strains adapted by specific genetic mutations, which became fixed in the evolved populations. By monitoring the phenotypic changes at the population and single-cell levels, we found that the first adaptive change to antibiotic stress was the development of tolerance through a major adjustment in the single-cell lag-time distribution, without a change in resistance. Strikingly, we found that the lag time of bacteria before regrowth was optimized to match the duration of the antibiotic-exposure interval. Whole genome sequencing of the evolved strains and restoration of the wild-type alleles allowed us to identify target genes involved in this antibiotic-driven phenotype: 'tolerance by lag' (tbl). Better understanding of lag-time evolution as a key determinant of the survival of bacterial populations under high antibiotic concentrations could lead to new approaches to impeding the evolution of antibiotic resistance.
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