Many studies have examined how fuels, topography, climate, and fire weather influence fire severity. Less is known about how different forest management practices influence fire severity in ...multi-owner landscapes, despite costly and controversial suppression of wildfires that do not acknowledge ownership boundaries. In 2013, the Douglas Complex burned over 19,000 ha of Oregon & California Railroad (O&C) lands in Southwestern Oregon, USA. O&C lands are composed of a checkerboard of private industrial and federal forestland (Bureau of Land Management, BLM) with contrasting management objectives, providing a unique experimental landscape to understand how different management practices influence wildfire severity. Leveraging Landsat based estimates of fire severity (Relative differenced Normalized Burn Ratio, RdNBR) and geospatial data on fire progression, weather, topography, pre-fire forest conditions, and land ownership, we asked (1) what is the relative importance of different variables driving fire severity, and (2) is intensive plantation forestry associated with higher fire severity? Using Random Forest ensemble machine learning, we found daily fire weather was the most important predictor of fire severity, followed by stand age and ownership, followed by topographic features. Estimates of pre-fire forest biomass were not an important predictor of fire severity. Adjusting for all other predictor variables in a general least squares model incorporating spatial autocorrelation, mean predicted RdNBR was higher on private industrial forests (RdNBR 521.85 ± 18.67 mean ± SE) vs. BLM forests (398.87 ± 18.23) with a much greater proportion of older forests. Our findings suggest intensive plantation forestry characterized by young forests and spatially homogenized fuels, rather than pre-fire biomass, were significant drivers of wildfire severity. This has implications for perceptions of wildfire risk, shared fire management responsibilities, and developing fire resilience for multiple objectives in multi-owner landscapes.
Christopher Dunn's history of authoritarian Brazil exposes the inventive cultural production and intense social transformations that emerged during the rule of an iron-fisted military regime during ...the sixties and seventies. The Braziliancontraculturawas a complex and multifaceted phenomenon that developed alongside the ascent of hardline forces within the regime in the late 1960s. Focusing on urban, middle-class Brazilians often inspired by the international counterculture that flourished in the United States and parts of western Europe, Dunn shows how new understandings of race, gender, sexuality, and citizenship erupted under even the most oppressive political conditions.Dunn reveals previously ignored connections between the counterculture and Brazilian music, literature, film, visual arts, and alternative journalism. In chroniclingdesbunde, the Brazilian hippie movement, he shows how the state of Bahia, renowned for its Afro-Brazilian culture, emerged as a countercultural mecca for youth in search of spiritual alternatives. As this critical and expansive book demonstrates, many of the country's social and justice movements have their origins in the countercultural attitudes, practices, and sensibilities that flourished during the military dictatorship.
As contemporary wildfire activity intensifies across the western United States, there is increasing recognition that a variety of forest management activities are necessary to restore ecosystem ...function and reduce wildfire hazard in dry forests. However, the pace and scale of current, active forest management is insufficient to address restoration needs. Managed wildfire and landscape-scale prescribed burns hold potential to achieve broad-scale goals but may not achieve desired outcomes where fire severity is too high or too low. To explore the potential for fire alone to restore dry forests, we developed a novel method to predict the range of fire severities most likely to restore historical forest basal area, density, and species composition in forests across eastern Oregon. First, we developed probabilistic tree mortality models for 24 species based on tree characteristics and remotely sensed fire severity from burned field plots. We applied these estimates to unburned stands in four national forests to predict post-fire conditions using multi-scale modeling in a Monte Carlo framework. We compared these results to historical reconstructions to identify fire severities with the highest restoration potential. Generally, we found basal area and density targets could be achieved by a relatively narrow range of moderate-severity fire (roughly 365-560 RdNBR). However, single fire events did not restore species composition in forests that were historically maintained by frequent, low-severity fire. Restorative fire severity ranges for stand basal area and density were strikingly similar for ponderosa pine (Pinus ponderosa) and dry mixed-conifer forests across a broad geographic range, in part due to relatively high fire tolerance of large grand (Abies grandis) and white fir (Abies concolor). Our results suggest historical forest conditions created by recurrent fire are not readily restored by single fires and landscapes have likely passed thresholds that preclude the effectiveness of managed wildfire alone as a restoration tool.
Large and severe wildfires are an observable consequence of an increasingly arid American West. There is increasing consensus that human communities, land managers, and fire managers need to adapt ...and learn to live with wildfires. However, a myriad of human and ecological factors constrain adaptation, and existing science-based management strategies are not sufficient to address fire as both a problem and solution. To that end, we present a novel risk-science approach that aligns wildfire response decisions, mitigation opportunities, and land management objectives by consciously integrating social, ecological and fire management system needs. We use fire-prone landscapes of the US Pacific Northwest as our study area, and report on and describe how three complementary risk-based analytic tools-quantitative wildfire risk assessment, mapping of suppression difficulty, and atlases of potential control locations-can form the foundation for adaptive governance in fire management. Together, these tools integrate wildfire risk with fire management difficulties and opportunities, providing a more complete picture of the wildfire risk management challenge. Leveraging recent and ongoing experience integrating local experiential knowledge with these tools, we provide examples and discuss how these geospatial datasets create a risk-based planning structure that spans multiple spatial scales and uses. These uses include pre-planning strategic wildfire response, implementing safe wildfire response balancing risk with likelihood of success, and alignment of non-wildfire mitigation opportunities to support wildfire risk management more directly. We explicitly focus on multi-jurisdictional landscapes to demonstrate how these tools highlight the shared responsibility of wildfire risk mitigation. By integrating quantitative risk science, expert judgement and adaptive co-management, this process provides a much-needed pathway to transform fire-prone social ecological systems to be more responsive and adaptable to change and live with fire in an increasingly arid American West.
Cockayne syndrome (CS) is an accelerated aging disorder characterized by progressive neurodegeneration caused by mutations in genes encoding the DNA repair proteins CS group A or B (CSA or CSB). ...Since dietary interventions can alter neurodegenerative processes, Csbm/m mice were given a high-fat, caloric-restricted, or resveratrol-supplemented diet. High-fat feeding rescued the metabolic, transcriptomic, and behavioral phenotypes of Csbm/m mice. Furthermore, premature aging in CS mice, nematodes, and human cells results from aberrant PARP activation due to deficient DNA repair leading to decreased SIRT1 activity and mitochondrial dysfunction. Notably, β-hydroxybutyrate levels are increased by the high-fat diet, and β-hydroxybutyrate, PARP inhibition, or NAD+ supplementation can activate SIRT1 and rescue CS-associated phenotypes. Mechanistically, CSB can displace activated PARP1 from damaged DNA to limit its activity. This study connects two emerging longevity metabolites, β-hydroxybutyrate and NAD+, through the deacetylase SIRT1 and suggests possible interventions for CS.
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•Hyperactivation of PARP1 drives SIRT1 depression in Cockayne syndrome (CS)•A high-fat diet, β-hydroxybutyrate, or NAD+ replenishment rescue phenotypes in CS•PARP inhibition and β-hydroxybutyrate increase SIRT1 activity in CS-cells•CSB displaces PARylated PARP1 from damaged DNA and suppresses its activity
Cockayne syndrome group B (CSB) is associated with hyperactivation of the DNA damage response enzyme PARP1 leading to NAD+ depletion, SIRT1 attenuation, and decreased acetyl-CoA formation. Increasing NAD+ or enhancing acetyl-CoA via ketogenesis rescues the accelerated aging. CSB protein interacts with PARP1 to prevent increasing signaling.
High-quality and complete reference genome assemblies are fundamental for the application of genomics to biology, disease, and biodiversity conservation. However, such assemblies are available for ...only a few non-microbial species
. To address this issue, the international Genome 10K (G10K) consortium
has worked over a five-year period to evaluate and develop cost-effective methods for assembling highly accurate and nearly complete reference genomes. Here we present lessons learned from generating assemblies for 16 species that represent six major vertebrate lineages. We confirm that long-read sequencing technologies are essential for maximizing genome quality, and that unresolved complex repeats and haplotype heterozygosity are major sources of assembly error when not handled correctly. Our assemblies correct substantial errors, add missing sequence in some of the best historical reference genomes, and reveal biological discoveries. These include the identification of many false gene duplications, increases in gene sizes, chromosome rearrangements that are specific to lineages, a repeated independent chromosome breakpoint in bat genomes, and a canonical GC-rich pattern in protein-coding genes and their regulatory regions. Adopting these lessons, we have embarked on the Vertebrate Genomes Project (VGP), an international effort to generate high-quality, complete reference genomes for all of the roughly 70,000 extant vertebrate species and to help to enable a new era of discovery across the life sciences.
Objective
Alterations of the gut microbiota have been implicated in many forms of arthritis, but an examination of cartilage microbial patterns has not been performed. This study was undertaken to ...characterize the microbial DNA profile of articular cartilage and determine changes associated with osteoarthritis (OA).
Methods
We performed 16S ribosomal RNA gene deep sequencing on eroded and intact cartilage samples from knee OA patients (n = 21 eroded and 21 intact samples) and hip OA patients (n = 34 eroded and 33 intact samples) and cadaver controls (n = 10 knee samples and 10 hip samples). Microbial DNA diversity was assessed, groups were compared, and metagenomic profiles were reconstructed. Confirmation was performed in an independent cohort by clade‐specific quantitative polymerase chain reaction. Findings in human cartilage were compared to those in cartilage from OA‐susceptible C57BL/6 (B6) mice and OA‐resistant MRL/MpJ (MRL) mice. Germ‐free B6 mouse cartilage was analyzed as a methodologic control.
Results
Alpha diversity was reduced in human OA versus control samples (P < 0.0001), and in hip versus knee samples (P < 0.0001). Numerous clades were different in human OA versus control samples, and similar findings were noted in comparisons of murine B6 versus MRL mice. Hip samples were microbiologically distinct from knee samples. OA microbial DNA demonstrated increased gram‐negative constituents (P = 0.02). Functional analysis demonstrated increases in lipopolysaccharide production (P = 9.9 × 10−3), phosphatidylinositol signaling (P = 4.2 × 10−4), and nitrogen metabolism (P = 8 × 10−3) and decreases in sphingolipid metabolism (P = 7.7 × 10−4) associated with OA.
Conclusion
Our study reveals a microbial DNA signature in human and mouse cartilage. Alterations in this signature, including increases in gram‐negative constituents, occur during the development and progression of human OA. Furthermore, our findings indicate that strain‐specific signatures exist within mouse cartilage that mirror human patterns. Further study of the establishment and potential pathogenic role of these DNA signatures is needed.
Knee osteoarthritis (OA) is a leading cause of chronic disability worldwide, but no diagnostic or prognostic biomarkers are available. Increasing evidence supports epigenetic dysregulation as a ...contributor to OA pathogenesis. In this pilot study, we investigated epigenetic patterns in peripheral blood mononuclear cells (PBMCs) as models to predict future radiographic progression in OA patients enrolled in the longitudinal Osteoarthritis Initiative (OAI) study. PBMC DNA was analyzed from baseline OAI visits in 58 future radiographic progressors (joint space narrowing at 24 months, sustained at 48 months) compared to 58 non-progressors. DNA methylation was quantified via Illumina microarrays and beta- and M-values were used to generate linear classification models. Data were randomly split into a 60% development and 40% validation subsets, models developed and tested, and cross-validated in a total of 40 cycles. M-value based models outperformed beta-value based models (ROC-AUC 0.81 ± 0.01 vs. 0.73 ± 0.02, mean ± SEM, comparison p = 0.002), with a mean classification accuracy of 73 ± 1% (mean ± SEM) for M- and 69 ± 1% for beta-based models. Adjusting for covariates did not significantly alter model performance. Our findings suggest that PBMC DNA methylation-based models may be useful as biomarkers of OA progression and warrant additional evaluation in larger patient cohorts.
Deputy ministers in Canada Dunn, Christopher; Bourgault, Jacques
Deputy ministers in Canada,
2014, 2014, 2014-01-27, 2014-02-05
eBook
Collectively, provincial deputy ministers command the largest assembly of government budgets, employees, and influence in Canada, but despite their importance, they have not been the subject of ...systematic study until now. This unique volume, which deals with a uniquely significant topic, reviews the role of deputy ministers within government, providing a major new understanding of their responsibilities and interactions at both the federal and provincial levels. It also contributes important comparative analysis not previously available.
Featuring contributions by many of Canada’s most prominent scholars of public administration, Deputy Ministers in Canada examines a number of factors in the evolution of deputies’ roles. Taking into account social, political, and administrative history, the essays probe topics such as the socio-economic characteristics of administrative elites, the politicization of recruitment processes, the impact of New Public Management, and varieties of ministerial-bureaucratic relations. Together, the essays in Deputy Ministers in Canada make an important contribution to the political science and public administration literature.
Long-read sequence assembly of the gorilla genome Gordon, David; Huddleston, John; Chaisson, Mark J. P. ...
Science (American Association for the Advancement of Science),
04/2016, Letnik:
352, Številka:
6281
Journal Article
Recenzirano
Odprti dostop
Accurate sequence and assembly of genomes is a critical first step for studies of genetic variation. We generated a high-quality assembly of the gorilla genome using single-molecule, real-time ...sequence technology and a string graph de novo assembly algorithm. The new assembly improves contiguity by two to three orders of magnitude with respect to previously released assemblies, recovering 87% of missing reference exons and incomplete gene models. Although regions of large, high-identity segmental duplications remain largely unresolved, this comprehensive assembly provides new biological insight into genetic diversity, structural variation, gene loss, and representation of repeat structures within the gorilla genome. The approach provides a path forward for the routine assembly of mammalian genomes at a level approaching that of the current quality of the human genome.
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