Historical fire regimes in ponderosa pine forests of the Colorado Front Range, and recommendations for ecological restoration and fuels management

At the request of The Nature Conservancy and the Front Range Fuels Treatment Partnership, the authors of this article are developing brief summaries of the current state of our scientific understanding of historical fire regimes in the forested landscapes of Colorado's Front Range. The area of interest extends from EI Paso and Teller Counties, near Pikes Peak, to Larimer County and the Colorado-Wyoming border. This article focuses on forests in which ponderosa pine is a dominant or co-dominant species. A subsequent article will deal with forests of lodgepole pine, spruce, and fir. M. Kaufmann and T. Veblen have conducted extensive studies of ponderosa pine forest ecology in the southern Front Range (mainly the Cheesman Reservoir area) and the northern Front Range (mainly in and around Boulder County), respectively. This research has led to substantial agreement about the historical role of fire in shaping these forests, and we emphasize these points of agreement in this article, in the section entitled "Things We Know with Relatively High Confidence." Some disagreements and uncertainties also have arisen, and we identify these..

Old-growth forests: what do we know about their ecology and management in the Southwest and Rocky Mountain Regions?

This paper reviews the science and management of old-growth forests and summarizes discussions among 30 participants at a workshop in Portal, Arizona, March 9-13, 1992. Concepts of old-growth forests -- the perceptions, values, definitions, characteristic features, ecological functions, and landscape importance -- vary widely. Because concepts are complex, scientists, resource managers, and the public will continue to bring old growth into clearer focus as knowledge is gained. Regardless of the concepts chosen for viewing old growth, on an ecological basis old-growth forests represent a stage in forest development characterized by certain structural, functional, and compositional features. Managers are concerned with how much old growth exists, where it is, and what condition it is in. Improved inventory procedures are needed, including both remote-sensing technology and conventional on-the-ground procedures. Where will tomorrows old growth be found, and how soon will younger stands attain old-growth conditions? Pathways of forest succession into old growth are poorly known for most forest types. We need better knowledge about how disturbances such as fire, insects, forest diseases, exotic organisms, pollution, and changing climate affect old growth and forest succession. Allocation is another problem for planners. How much old growth is enough? How many stands should be old growth at any given time, what are the sizes and shapes of the stands, and how should they be distributed over various forest habitat types? How should old-growth stands be connected by forest corridors, and how are their functions modified by their setting? These are difficult but researchable questions. Lacking clear answers to these questions, should managers find clues from pre-European settlement forests? Is it reasonable to attempt to restore forests to their natural conditions? Or have changes since settlement precluded returning to earlier conditions? In this paper, we review our knowledge of the influence old-growth stands on biogeochemical cycles and the roles of wildlife, decomposer organisms, cryptozoans of logs and snags, and other kinds of hidden diversity. To what extent are the legacy of old trees and other genetic reserves in old-growth forests carried into the future? We know little about how present old-growth influences the development of future forest generations. We conclude by looking at some tools for old-growth management. How can managers use fire or silviculture to assure future old-growth supplies, while at the same time meeting present and future extractive demands? Can younger stands be treated to hasten their development into old growth, or can existing old growth be altered without seriously compromising old-growth value

An Ecological Basis for Ecosystem Management

This report was prepared by the Southwestern Regional Ecosystem Management Study Team composed of management and research biologists. The USDA Forest Service Southwestern Regions Regional Forester, Larry Henson, and the Rocky Mountain Forest and Range Experiment Station Director, Denver Burns, chartered this team to recommend an ecological basis for ecosystem management. This report is not intended to provide details on all aspects of ecosystem management; it simply provides information and makes recommendations for an ecological basis for ecosystem management. The report is not a decision document. It does not allocate resources on public lands nor does it make recommendations to that effect. The report of this Study Team may be relied upon as input in processes initiated under the National Environmental Policy Act (NEPA), National Forest Management Act (NFMA), Endangered Species Act (ESA), Administrative Procedures Act (APA), and other applicable laws. The information contained in this report is general in nature, rather than site specific. Implementation of ecosystem management and allocation of resources on Forest Service administered lands is the responsibility of the National Forest System in partnership with Forest Service Research and State and Private Forestry. Implementation is done through Forest and project plans that are subject to the NEPA process of disclosing the effects of proposed actions and affording the opportunity for public comment. The Southwestern Region follows a planning process for projects called Integrated Resource Management (IRM). The opinions expressed by the authors do not necessarily represent the policy or position of the U.S. Department of Agriculture, the Forest Service, The Nature Conservancy, or the Arizona Game and Fish Department. The Study Team acknowledges the valuable input of more than 50 individuals from various agencies, universities, professional organizations, and other groups who provided thoughtful comments of an earlier draft of this document. Some of their comments are included in Appendix 3

Origin of the submillimeter radio emission during the time-extended phase of a solar flare

Solar flares observed in the 200-400 GHz radio domain may exhibit a slowly varying and time-extended component which follows a short (few minutes) impulsive phase and which lasts for a few tens of minutes to more than one hour. The few examples discussed in the literature indicate that such long-lasting submillimeter emission is most likely thermal bremsstrahlung. We present a detailed analysis of the time-extended phase of the 2003 October 27 (M6.7) flare, combining 1-345 GHz total-flux radio measurements with X-ray, EUV, and H{\alpha} observations. We find that the time-extended radio emission is, as expected, radiated by thermal bremsstrahlung. Up to 230 GHz, it is entirely produced in the corona by hot and cool materials at 7-16 MK and 1-3 MK, respectively. At 345 GHz, there is an additional contribution from chromospheric material at a few 10^4 K. These results, which may also apply to other millimeter-submillimeter radio events, are not consistent with the expectations from standard semi-empirical models of the chromosphere and transition region during flares, which predict observable radio emission from the chromosphere at all frequencies where the corona is transparent.Comment: 27 pages, 7 figure

Refphase: Multi-sample phasing reveals haplotype-specific copy number heterogeneity

Most computational methods that infer somatic copy number alterations (SCNAs) from bulk sequencing of DNA analyse tumour samples individually. However, the sequencing of multiple tumour samples from a patient's disease is an increasingly common practice. We introduce Refphase, an algorithm that leverages this multi-sampling approach to infer haplotype-specific copy numbers through multi-sample phasing. We demonstrate Refphase's ability to infer haplotype-specific SCNAs and characterise their intra-tumour heterogeneity, to uncover previously undetected allelic imbalance in low purity samples, and to identify parallel evolution in the context of whole genome doubling in a pan-cancer cohort of 336 samples from 99 tumours

Post-ischaemic silencing of p66Shc reduces ischaemia/reperfusion brain injury and its expression correlates to clinical outcome in stroke

In light of the limited repertoire of therapeutical options available for the treatment of ischaemic stroke, the identification of novel potential targets is vital; in this respect, the present study demonstrates that the adaptor protein p66Shc holds this potential as an adjunct therapy to thrombolysis. Post-ischaemic silencing of p66Shc protein yielded beneficial effects in a mouse model of I/R brain injury underlying an interesting translational perspective for this target protein. Further, in proof-of-principle clinical experiments using PBMs, we demonstrate that p66Shc gene expression is transiently increased and that its levels correlate to short-term outcome in ischaemic stroke patients. Although these latter experiments are not directly relevant to the experiments performed in mice and in human endothelial cells, they provide novel important information about p66Shc regulation in stroke patients and set the basis for further investigations aimed at assessing the potential for p66Shc to become a novel therapeutic target as an adjunct of thrombolysis for the management of acute ischaemic strok

The geology and geophysics of Kuiper Belt object (486958) Arrokoth

The Cold Classical Kuiper Belt, a class of small bodies in undisturbed orbits beyond Neptune, are primitive objects preserving information about Solar System formation. The New Horizons spacecraft flew past one of these objects, the 36 km long contact binary (486958) Arrokoth (2014 MU69), in January 2019. Images from the flyby show that Arrokoth has no detectable rings, and no satellites (larger than 180 meters diameter) within a radius of 8000 km, and has a lightly-cratered smooth surface with complex geological features, unlike those on previously visited Solar System bodies. The density of impact craters indicates the surface dates from the formation of the Solar System. The two lobes of the contact binary have closely aligned poles and equators, constraining their accretion mechanism

Fine-Scale Mapping of the 5q11.2 Breast Cancer Locus Reveals at Least Three Independent Risk Variants Regulating MAP3K1

Peer reviewe

An Observational Overview of Solar Flares

We present an overview of solar flares and associated phenomena, drawing upon a wide range of observational data primarily from the RHESSI era. Following an introductory discussion and overview of the status of observational capabilities, the article is split into topical sections which deal with different areas of flare phenomena (footpoints and ribbons, coronal sources, relationship to coronal mass ejections) and their interconnections. We also discuss flare soft X-ray spectroscopy and the energetics of the process. The emphasis is to describe the observations from multiple points of view, while bearing in mind the models that link them to each other and to theory. The present theoretical and observational understanding of solar flares is far from complete, so we conclude with a brief discussion of models, and a list of missing but important observations.Comment: This is an article for a monograph on the physics of solar flares, inspired by RHESSI observations. The individual articles are to appear in Space Science Reviews (2011