Surface Fuel Loadings in Mulching Treatments in Colorado Coniferous Forests

Recent large-scale, severe wildfires in the western United States have prompted extensive fuel treatment programs to reduce potential wildfire size and severity. Often, unmerchantable material is mechanically masticated because removing the material is cost-prohibitive. Mastication treatments involve shredding, chopping, or chipping small trees and/or shrubs into small chunks and leaving the material on site. While it is obvious that mechanical treatments will increase surface fuel loads, few studies have addressed how treatments alter fuel particle size and quantity. We examined how mastication treatments alter the distribution of woody material size by comparing paired masticated and untreated sites in lodgepole pine (Pinus contorta), ponderosa pine/Douglas-fir (Pinus ponderosa/Pseudotsuga menziesii), and 3) Pinyon pine (Pinus edulis) ecosystems 2-4 years after mechanical treatment. As expected, total woody fuel loadings increased in the treated areas of each ecosystem. However, the magnitude of the total increase differed among the ecosystems (lodgepole pine \u3e ponderosa pine \u3e pinyon-juniper). Average total woody fuel loads in the untreated areas ranged between 7 to 9 Mg/ha, but increased to 29 to 50 Mg/ha in treated areas. Large diameter fuels (\u3e7.62 cm) represent about 33 to 65% of the total woody fuel load in the untreated areas, but only about 11% of the total fuel load in the treated areas. The majority of woody fuels in treated areas were \u3c2.54 cm in diameter. Needle litter mass was similar among treatments, indicating that needles are still a component of the forest floor complex, but are mixed with other fuel types or buried. The increased surface woody fuel component in treated areas corresponds to a shift from a needle fuel bed to a compact woody/needle fuel bed. This change in the fuel bed composition and orientation will likely influence fire behavior and effects

Case ascertainment uncertainties in prevalence surveys of Parkinson's disease

Using unpublished data from five completed prevalence surveys of Parkinson's disease (PD), we investigated case ascertainment uncertainties that potentially have a direct effect on prevalence. These uncertainties arise from the choice of diagnostic criteria, the choice of screening method, and the amount of information lost because of nonresponse. The surveys were conducted in Argentina, India, China, Italy, and the Netherlands. Our analyses consisted of simple comparisons of prevalence results, positive predictive values (a screening measure), and nonresponse percentages. We found that (a) prevalence comparisons between surveys have diminished value if the surveys used different diagnostic criteria for PD; (b) screening performance may be affected adversely if symptom questions are answered by one family member for the entire family living together rather than by each family member individually; and (c) nonresponse from refusal or unavailability does not necessarily lead to bias, but special caution may be appropriate with prevalence results pertaining to elderly women

Autour du fonds Poinssot

Julien Poinssot (1844-1900), Louis Poinssot (1879-1967) et Claude Poinssot (1928-2002), archéologues de père en fils, ont été, à des titres divers, des acteurs et des témoins privilégiés de l’histoire de l’archéologie en Tunisie. Entre les années 1870 et 1990, ils ont réuni un ensemble documentaire exceptionnel et original sur l’histoire de l’Afrique du Nord, de l’Antiquité au XXe siècle. Constitué d’une bibliothèque de plus de 4 500 volumes, de 25 mètres-linéaires d’archives issues de leurs recherches et de celles de leurs confrères – Bernard Roy (1846-1919), Paul Gauckler (1866-1911), Alfred Merlin (1876-1965) – le fonds Poinssot offre aux chercheurs d’aujourd’hui une documentation sans équivalent sur l’archéologie française en Afrique du Nord. Les contributions présentées ici explorent l’activité de trois générations de chercheurs, mus autant par le culte de l’archéologie que par le respect du document. Elles mettent au jour les multiples aspects de l’activité scientifique de cette famille d’archéologues, tout autant que les contraintes intellectuelles, matérielles et économiques qui pesaient sur elle

Atomic force microscopy of DNA in solution and DNA modelling show that structural properties specify the eukaryotic replication initiation site

The replication origins (ORIs) of Schizosaccharomyces pombe, like those in most eukaryotes, are long chromosomal regions localized within A+T-rich domains. Although there is no consensus sequence, the interacting proteins are strongly conserved, suggesting that DNA structure is important for ORI function. We used atomic force microscopy in solution and DNA modelling to study the structural properties of the Spars1 origin. We show that this segment is the least stable of the surrounding DNA (9 kb), and contains regions of intrinsically bent elements (strongly curved and inherently supercoiled DNAs). The pORC-binding site co-maps with a superhelical DNA region, where the spatial arrangement of adenine/thymine stretches may provide the binding substrate. The replication initiation site (RIP) is located within a strongly curved DNA region. On pORC unwinding, this site shifts towards the apex of the curvature, thus potentiating DNA melting there. Our model is entirely consistent with the sequence variability, large size and A+T-richness of ORIs, and also accounts for the multistep nature of the initiation process, the specificity of pORC-binding site(s), and the specific location of RIP. We show that the particular DNA features and dynamic properties identified in Spars1 are present in other eukaryotic origins

Mechanics of the IL2RA Gene Activation Revealed by Modeling and Atomic Force Microscopy

Transcription implies recruitment of RNA polymerase II and transcription factors (TFs) by DNA melting near transcription start site (TSS). Combining atomic force microscopy and computer modeling, we investigate the structural and dynamical properties of the IL2RA promoter and identify an intrinsically negative supercoil in the PRRII region (containing Elf-1 and HMGA1 binding sites), located upstream of a curved DNA region encompassing TSS. Conformational changes, evidenced by time-lapse studies, result in the progressive positioning of curvature apex towards the TSS, likely facilitating local DNA melting. In vitro assays confirm specific binding of the General Transcription Factors (GTFs) TBP and TFIIB over TATA-TSS position, where an inhibitory nucleosome prevented preinitiation complex (PIC) formation and uncontrolled DNA melting. These findings represent a substantial advance showing, first, that the structural properties of the IL2RA promoter are encoded in the DNA sequence and second, that during the initiation process DNA conformation is dynamic and not static

Granulysin, a novel marker for extranodal NK/T cell lymphoma, nasal type

Granulysin is a cytolytic protein expressed in cytotoxic T and natural killer (NK) cells. Abnormal serum levels of granulysin in lymphomas with NK and cytotoxic phenotype have been shown to correlate with tumour progression. In this study, we investigated the expression pattern of granulysin in routine sections of normal and reactive lymphoid tissues as well as in a large series of lymphomas. In normal tissues, granulysin labelled a small population of cells that double immunostaining revealed to belong to the pool of cytotoxic T/NK cells. Among lymphoid neoplasms, the highest expression of granulysin (71%) was found in extranodal NK/T cell lymphomas of nasal type (ENKTL). To note is that 29% of ENKTLs, which were negative for one or more of classical cytotoxic markers strongly expressed granulysin. Furthermore, expression of granulysin was observed in rare cases of T cell lymphomas with a cytotoxic phenotype (i.e. ALK-negative anaplastic large cell lymphoma (26%), enteropathy-associated T cell lymphoma (12%) and peripheral T cell lymphoma, NOS (4%)). None of the investigated non-Hodgkin B cell lymphomas, Hodgkin lymphoma and plasma cell myeloma were granulysin positive. The results suggest granulysin as a novel marker for a subset of cytotoxic NK cell derived malignancies and its usefulness is highlighted in those ENKTLs that lack expression of other cytotoxic markers but retain granulysin expression

A regional assessment of the ecological effects of chipping and mastication fuels reduction and forest restoration treatments.

Over the past several years, fire managers have increased their use of mastication treatments, the on-site disposal of shrubs and small-diameter trees through chipping and shredding. Mastication is a relatively untested management practice that alters the chemical and physical conditions of the forest floor and may influence vegetation regrowth and fuel development for years or decades. Eighteen sites were established across four ecosystems of the southern Rocky Mountains and the Colorado Plateau: lodgepole pine (Pinus contorta), mixed conifer (Pinus ponderosa, Pseudotsuga menziesii, Pinus flexilis, and Pinus contorta), ponderosa pine (Pinus ponderosa), and pinyon pine/juniper (Pinus edulis/Juniperus sp.). These sites were distributed across a wide geographic range throughout Colorado and represent treatments across several federal, state, and other land agencies. The sites were mulched between 2004 and 2006 and first measured in 2007 or 2008. The mechanical treatment added a substantial amount of 1-hr and 10-hr woody fuel

Differences in Plant Species Composition as Evidence of Alternate States in the Sagebrush Steppe

State-and-transition models (STMs), conceptual models of vegetation change based on alternate state theory, are increasingly applied as tools for land management decision-making. As STMs are created throughout the United States, it is crucial to ensure that they are supported by ecological evidence. Plant species composition reflects ecosystem processes that are difficult to measure and may be a useful indicator of alternate states. This study aims to create data-driven STMs based on plant species composition for two ecological sites (Claypan and Mountain Loam) in northwestern Colorado sagebrush steppe. We sampled 76 plots with different management and disturbance histories. Drawing on the hierarchical approach currently taken to build STMs, we hypothesized that A) differences in species composition between the two ecological sites would be related to environmental factors and B) differences in species composition within each ecological site would be related to management and disturbance history. Relationships among species composition, site history, and environmental variables were evaluated using multivariate statistics. We found that between ecological sites, species composition was related to differences in soil texture, supporting Hypothesis A and the creation of separate STMs for each site. Within ecological sites, species composition was related to site history and also to environmental variation. This finding partially supports Hypothesis B and the identification of alternate states using species composition, but also suggests that these ecological sites are not uniform physical templates upon which plant community dynamics play out. This data-driven, plant species-based approach created two objective, credible STMs with states and transitions that are consistent with the sagebrush steppe literature. Our findings support the hierarchical view of landscapes currently applied in building STMs. An approach that acknowledges environmental heterogeneity within ecological sites is necessary to help define finer-resolution ecological sites and elucidate cases in which specific abiotic conditions make transitions between states more likely./Los Modelos de Estado y Transición (MET), que son modelos conceptuales en cambios de la vegetación basados la teoría delestado alternativo, su aplicación está en aumento como herramienta para la tomada de decisiones en el manejo de la tierra. Como los MET se han creado a través de los Estados Unidos, es vital que aseguremos que estos están apoyados por evidencia ecológica. La composición de especies refleja el proceso del ecosistema que es difícil de medir y podría ser un indicador útil d eestados alternativos. Este estudio ayuda a crear un MET dirigido por datos basado en las composición de especies de plantas dedos sitios ecológicos (Claypan y Mountain Loam) en la estepa de artemisa al noroeste de de Colorado. Muestramos 76 parcelas con diferente manejo e historias de disturbio. Dibujando el concepto jerárquico actualmente usado para construir los MET, establecimos las siguientes hipótesis A) Las diferencias en la composición de especies entre los dos sitios ecológicos podrían estar relacionadas a factores medioambientales y B) las diferencias en la composición de especies dentro de cada sitio ecológicos podrían estar relacionadas por el manejo y la historia de disturbio. Las relaciones entre la composición de especies, la historia del sitio y las variables medioambientales fueron evaluadas usando estadística multivariada. Encontramos que entre sitios ecológicos, la composición de especies estuvo relacionada con las diferentes texturas del suelo, apoyando la Hipotesis A y la creación de MET separados. Dentro de los sitios ecológicos, la composición de especies estuvo relacionada a la historia del sitio y también a variables medioambientales. Estos resultados apoyan parcialmente la Hipotesis B y la identificación de estados alternativos usando la composición de especies, pero también sugieren que estos sitios ecológicos no son uniformes en laplantilla física que es donde la dinámica de la comunidad vegetal se desenvuelve. Este concepto basado en datos dirigidos en especies de plantas creo dos objetivos, creíbles MET con estados y transiciones que son consistentes con la literatura de la estepade artemisa. Nuestros resultados apoyan el punto de vista jerárquico de paisajes que se usan actualmente para construir MET’s.Un enfoque que reconoce la heterogeneidad medioambiental dentro de sitios ecológicos es necesaria para ayudar a definir mejor resolución de sitios ecológicos y aclarar casos donde condiciones abióticas especificas hacen la transición mas probable.The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Challenges to Educating the Next Generation of Wildland Fire Professionals in the United States

Over the last 20 years, the duties of US fire professionals have become more complex and risk laden because of fuel load accumulation, climate change, and the increasing wildland-urban interface. Incorporation of fire use and ecological principles into fire management policies has further expanded the range of expertise and knowledge required of fire professionals. The educational and training systems that produce these professionals, however, have been slow to organize an updated and coordinated approach to preparing future practitioners. Consequently, aspiring fire professionals face numerous challenges related to scheduling conflicts, limited higher education programs in fire science, lack of coordination between fire training and higher education entities, and the overall difficulty of obtaining education and training without sacrificing experience. Here, we address these and other challenges with potential solutions and outline the first steps toward their implementation. We organize the necessary aspects of professional fire preparation into a representative model: a fire professional development triangle comprised of education, training, and experience. For each of these aspects, we suggest changes that can be made by employers, educators, and nongovernmental organizations to provide a more streamlined mechanism for preparing the next generation of wildland fire professionals in the United States