Basic principles of forest fuel reduction treatments

Successful fire exclusion in the 20th century has created severe fire problems across the West. Not every forest is at risk of uncharacteristically severe wildfire, but drier forests are in need of active management to mitigate fire hazard. We summarize a set of simple principles important to address in fuel reduction treatments: reduction of surface fuels, increasing the height to live crown, decreasing crown density, and retaining large trees of fire-resistant species. Thinning and prescribed fire can be useful tools to achieve these objectives. Low thinning will be more effective than crown or selection thinning, and management of surface fuels will increase the likelihood that the stand will survive a wildfire. Five empirical examples of such treatment are discussed: Hayfork fires, California, 1987; Tyee fire,Washington, 1994; Megram fire, California, 1999; Hayman fire, Colorado, 2002; and the Cone fire, California, 2002. Applying treatments at an appropriate landscape scale will be critical to the success of fuel reduction treatments in reducing wildfire losses in Western forests.Keywords: Prescribed fire, Western United States, Thinning, Fire ecology, Fuel treatmen

Basic principles of forest fuel reduction treatments

Successful fire exclusion in the 20th century has created severe fire problems across the West. Not every forest is at risk of uncharacteristically severe wildfire, but drier forests are in need of active management to mitigate fire hazard. We summarize a set of simple principles important to address in fuel reduction treatments: reduction of surface fuels, increasing the height to live crown, decreasing crown density, and retaining large trees of fire-resistant species. Thinning and prescribed fire can be useful tools to achieve these objectives. Low thinning will be more effective than crown or selection thinning, and management of surface fuels will increase the likelihood that the stand will survive a wildfire. Five empirical examples of such treatment are discussed: Hayfork fires, California, 1987; Tyee fire,Washington, 1994; Megram fire, California, 1999; Hayman fire, Colorado, 2002; and the Cone fire, California, 2002. Applying treatments at an appropriate landscape scale will be critical to the success of fuel reduction treatments in reducing wildfire losses in Western forests.Keywords: fire ecology, fuel treatment, western United States, prescribed fire, thinnin

The Mineralogical Record of Oxygen Fugacity Variation and Alteration in Northwest Africa 8159: Evidence for Interaction Between a Mantle Derived Martian Basalt and a Crustal Component(s)

A prominent geochemical feature of basaltic magmatism on Mars is the large range in initial Sr isotopic ratios (approx. 0.702 - 0.724) and initial epsilon-Nd values (approx. -10 to greater than +50). Within this range, the shergottites fall into three discreet subgroups. These subgroups have distinct bulk rock REE patterns, mineral chemistries (i.e. phosphate REE patterns, Ni, Co, V in olivine), oxygen fugacity of crystallization, and stable isotopes, such as O. In contrast, nakhlites and chassignites have depleted epsilon-Nd values (greater than or equal to +15), have REE patterns that are light REE enriched, and appear to have crystallized near the FMQ buffer. The characteristics of these various martian basalts have been linked to different reservoirs in the martian crust and mantle, and their interactions during the petrogenesis of these magmas. These observations pose interesting interpretive challenges to our understanding of the conditions of the martian mantle (e.g. oxygen fugacity) and the interaction of mantle derived magmas with the martian crust and surface. Martian meteorite NWA 8159 is a unique fine-grained augite basalt derived from a highly depleted mantle source as reflected in its initial epsilon-Nd value, contains a pronounced light REE depleted pattern, and crystallized presumably under very oxidizing conditions. Although considerably older than both shergottites and nahklites, it has been petrogenetically linked to both styles of martian magmatism. These unique characteristics of NWA 8159 may provide an additional perspective for deciphering the petrogenesis of martian basalts and the nature of the crust of Mars

Collagen Based Multicomponent Interpenetrating Networks as Promising Scaffolds for 3D Culture of Human Neural Stem Cells, Human Astrocytes, and Human Microglia

This work describes for the first time the fabrication and characterization of multicomponent interpenetrating networks composed of collagen I, hyaluronic acid, and poly(ethylene glycol) diacrylate for the 3D culture of human neural stem cells, astrocytes, and microglia. The chemical composition of the scaffolds can be modulated while maintaining values of complex moduli within the range of the mechanical performance of brain tissue (∼6.9 kPa) and having cell viability exceeding 84%. The developed scaffolds are a promising new family of biomaterials that can potentially serve as 3D in vitro models for studying the physiology and physiopathology of the central nervous system

Biomass and Burning Characteristics of Sugar Pine Cones

We investigated the physical and burning characteristics of sugar pine (Pinus lambertiana Douglas) cones and their contribution to woody surface fuel loadings. Field sampling was conducted at the Yosemite Forest Dynamics Plot (YFDP), a 25.6 ha mapped study plot in Yosemite National Park, California, USA. We developed a classification system to describe sugar pine cones of different sizes and decay conditions, and examined differences among cone classes in biomass, bulk density, flame length, burning time, consumption, and relative contribution to surface fuel loads. Sugar pine cones comprised 601 kg ha-1 of surface fuels. Mature cones comprised 54% of cone biomass, and aborted juvenile cones accounted for 44%. Cone biomass, diameter, and bulk density differed among cone condition classes, as did burning characteristics (one-way ANOVA, P \u3c 0.001 in all cases). Flame lengths ranged from 5 cm to 94 cm for juvenile cones, and 71 cm to 150 cm for mature cones. Our results showed that the developmental stage at which sugar pine cones become surface fuels determines their potential contribution to surface fire behavior in Sierra Nevada mixed-conifer forests. Sugar pine cones burn with greater flame lengths and flame times than the cones of other North American fire-tolerant pine species studied to date, indicating that cones augment the surface fire regime of sugar pine forests, and likely do so to a greater degree than do cones of other pine species

The University of Salford Sound of Laughter project

What follows is a report of the University of Salford’s Sound of Laughter Project (2018). This pilot study was set up as an initial attempt to ascertain whether it is possible to discern any meaning from the different laughter sounds that audiences might make during a stand-up comedy show. The experiment also aimed to discover whether comedians can recognise variations in the properties of laughter responses made during the act of public joking. Further, the study aimed to establish whether performers can discern these different audience laughter sounds in real time and use them as identifiable ‘cues’ to check the efficacy (or otherwise) of their comic communication. This combined report on the pilot study has been prepared by a group of researchers at the University of Salford, all of which were involved in different stages of the experiment and whose initials are appended to each relevant section of the report. Keywords: Audience laughter; stand-up comedy; joking; psychoacoustics, audience respons

Through a Glass, Darkly:The CIA and Oral History

This article broaches the thorny issue of how we may study the history of the CIA by utilizing oral history interviews. This article argues that while oral history interviews impose particular demands upon the researcher, they are particularly pronounced in relation to studying the history of intelligence services. This article, nevertheless, also argues that while intelligence history and oral history each harbour their own epistemological perils and biases, pitfalls which may in fact be pronounced when they are conjoined, the relationship between them may nevertheless be a productive one. Indeed, each field may enrich the other provided we have thought carefully about the linkages between them: this article's point of departure. The first part of this article outlines some of the problems encountered in studying the CIA by relating them to the author's own work. This involved researching the CIA's role in US foreign policy towards Afghanistan since a landmark year in the history of the late Cold War, 1979 (i.e. the year the Soviet Union invaded that country). The second part of this article then considers some of the issues historians must confront when applying oral history to the study of the CIA. To bring this within the sphere of cognition of the reader the author recounts some of his own experiences interviewing CIA officers in and around Washington DC. The third part then looks at some of the contributions oral history in particular can make towards a better understanding of the history of intelligence services and the CIA

Ecological effects of alternative fuel-reduction treatments: highlights of the National Fire and Fire Surrogate study (FFS)

The 12-site National Fire and Fire Surrogate study (FFS) was a multivariate experiment that evaluated ecological consequences of alternative fuel-reduction treatments in seasonally dry forests of the US. Each site was a replicated experiment with a common design that compared an un-manipulated control, prescribed fire, mechanical and mechanical + fire treatments. Variables within the vegetation, fuelbed, forest floor and soil, bark beetles, tree diseases and wildlife were measured in 10-ha stands, and ecological response was compared among treatments at the site level, and across sites, to better understand the influence of differential site conditions. For most sites, treated stands were predicted to be more resilient to wildfire if it occurred shortly after treatment, but for most ecological variables, short-term response to treatments was subtle and transient. Strong site-specificity was observed in the response of most ecosystem variables, suggesting that practitioners employ adaptive management at the local scale. Because ecosystem components were tightly linked, adaptive management would need to include monitoring of a carefully chosen set of key variables. Mechanical treatments did not serve as surrogates for fire for most variables, suggesting that fire be maintained whenever possible. Restoration to pre-settlement conditions will require repeated treatments over time, with eastern forests requiring more frequent applications.Keywords: Oak, Prescribed fire, Frequent fire regimes, Pine, Mechanical treatment, Forest thinning, Dry forest management, Seasonally dry forest

Association studies of up to 1.2 million individuals yield new insights into the genetic etiology of tobacco and alcohol use

Tobacco and alcohol use are leading causes of mortality that influence risk for many complex diseases and disorders 1 . They are heritable 2,3 and etiologically related 4,5 behaviors that have been resistant to gene discovery efforts 6–11 . In sample sizes up to 1.2 million individuals, we discovered 566 genetic variants in 406 loci associated with multiple stages of tobacco use (initiation, cessation, and heaviness) as well as alcohol use, with 150 loci evidencing pleiotropic association. Smoking phenotypes were positively genetically correlated with many health conditions, whereas alcohol use was negatively correlated with these conditions, such that increased genetic risk for alcohol use is associated with lower disease risk. We report evidence for the involvement of many systems in tobacco and alcohol use, including genes involved in nicotinic, dopaminergic, and glutamatergic neurotransmission. The results provide a solid starting point to evaluate the effects of these loci in model organisms and more precise substance use measures