Stratigraphy and petrogenesis of the Parana continental flood basalts, southern Brazil

The Early Cretaceous (~130 Ma) Paraná lavas of South America represent the largest preserved example of a continental flood basalt (CFB) province, with a present area in excess of 1.2 x 106 km2. Magmatism is dominated by tholeiitic basalts (> 90 %), with minor rhyolites as a late-stage feature along the continental margin. The basaltic magmas show a wide diversity in trace element and isotope composition, and a revised scheme of distinct magma types is proposed, based on new geochemical data plus a review of literature analyses, which retains the previously established overall classification into high and low-Ti varieties; viz. high-Ti (> 2 wt%) - (Urubici, Pitanga, Paranapanema}, low-Ti (< 2 wt%) - (Gramado, Esmeralda, Ribeira). A preliminary regional picture of the internal north-south structure of the lava pile is presented, constrained largely by analyses of borehole drilicore chippings which have provided a window to the otherwise inaccessible deeper stratigraphical levels. Within this central/north Paraná region, the dominant magma type has evolved from Gramado to Pitangato Paranapanema with time. The stratigraphical pattern of overlapping geochemical units which dip towards the north suggests a northward migrating source for the Parana magmatism, and this was probably related to the rapid northward propagation of initial rifting of the South Atlantic ocean rather than any motion relative to an underlying hot-spot. Detailed stratigraphical investigations on the coastal Serra Geral escarpment (Santa Catarina state, Brazil) showed complex interbedding of Urubici- and Granzado- type flows. Division of the Urubici-type flows into locally correlated sub-units has allowed the effects of polybaric fractionation to be resolved. The Gramado magma type is dominated by AFC (assimilation / fractional crystallisation), and the geochemical variations are consistent with taking an average Palmas rhyolite composition (the best estimate of a local crustal melt) to be the contaminant. Within the southern Paraná region, the composition of the Gramado parental magma prior to AFC is regionally variable (in terms of Ba/Nb, (87Sr/86Sr)i, SiO2). The Urubici and Gramado magma types can not be related to a single mantle source by varying degrees of partial melting, and require distinct source regions. The 'enriched' isotopic and trace element signatures inferred for uncontaminated Gramado- and Urubicitype magmas are distinct from MORB-OIB and it is suggested that at least the trace elements (and therefore the isotopic characteristics) of the Paranä CFB were largely derived from sources within a heterogeneous lithospheric mantle. The sharp stratigraphical transition from the lithospheric-dominated Gramado magma type to more 'depleted' trace element and isotope compositions (the minor Esmeralda magma type) can not be accommodated on trace element grounds by a decrease in the amount of crustal assimilation. Instead, these late-stages of magmatism show a significant asthenospheric component, consistent with such material being available during the advanced stages of lithospheric attenuation and rifting

Disaster preparedness training for tribal leaders

It was with considerable irony that tribal leaders began a collaboration with the University of Arizona and the Arizona Department of Health Services for training in public health preparedness, as the tribes had an extended prior history of responding to a host of hazards caused by the dominant culture. The objective of the training was to ensure that Native American communities were adequately informed and trained to implement coordinated response plans for a range of potential public health emergencies on tribal lands and in surrounding communities. This commentary outlines how cultural competency (including public prayer by an elder during the training), respect for tribal sovereignity, solicitation of historical examples of indigenous preparedness, and incorporation of tribal community networks were essential to the success of this program

Boninite and Harzburgite from Leg 125 (Bonin-Mariana Forearc): A Case Study of Magma Genesis during the Initial Stages of Subduction

Holes drilled into the volcanic and ultrabasic basement of the Izu-Ogasawara and Mariana forearc terranes during Leg 125 provide data on some of the earliest lithosphere created after the start of Eocene subduction in the Western Pacific. The volcanic basement contains three boninite series and one tholeiite series. (1) Eocene low-Ca boninite and low-Ca bronzite andesite pillow lavas and dikes dominate the lowermost part of the deep crustal section through the outer-arc high at Site 786. (2) Eocene intermediate-Ca boninite and its fractionation products (bronzite andesite, andesite, dacite, and rhyolite) make up the main part of the boninitic edifice at Site 786. (3) Early Oligocene intermediate-Ca to high-Ca boninite sills or dikes intrude the edifice and perhaps feed an uppermost breccia unit at Site 786. (4) Eocene or Early Oligocene tholeiitic andesite, dacite, and rhyolite form the uppermost part of the outer-arc high at Site 782. All four groups can be explained by remelting above a subduction zone of oceanic mantle lithosphere that has been depleted by its previous episode of partial melting at an ocean ridge. We estimate that the average boninite source had lost 10-15 wt% of melt at the ridge before undergoing further melting (5-10%) shortly after subduction started. The composition of the harzburgite (<2% clinopyroxene, Fo content of about 92%) indicates that it underwent a total of about 25% melting with respect to a fertile MORB mantle. The low concentration of Nb in the boninite indicates that the oceanic lithosphere prior to subduction was not enriched by any asthenospheric (OIB) component. The subduction component is characterized by (1) high Zr and Hf contents relative to Sm, Ti, Y, and middle-heavy REE, (2) light REE-enrichment, (3) low contents of Nb and Ta relative to Th, Rb, or La, (4) high contents of Na and Al, and (5) Pb isotopes on the Northern Hemisphere Reference Line. This component is unlike any subduction component from active arc volcanoes in the Izu-Mariana region or elsewhere. Modeling suggests that these characteristics fit a trondhjemitic melt from slab fusion in amphibolite facies. The resulting metasomatized mantle may have contained about 0.15 wt% water. The overall melting regime is constrained by experimental data to shallow depths and high temperatures (1250°C and 1.5 kb for an average boninite) of boninite segregation. We thus envisage that boninites were generated by decompression melting of a diapir of metasomatized residual MORB mantle leaving the harzburgites as the uppermost, most depleted residue from this second stage of melting. Thermal constraints require that both subducted lithosphere and overlying oceanic lithosphere of the mantle wedge be very young at the time of boninite genesis. This conclusion is consistent with models in which an active transform fault offsetting two ridge axes is placed under compression or transpression following the Eocene plate reorganization in the Pacific. Comparison between Leg 125 boninites and boninites and related rocks elsewhere in the Western Pacific highlights large regional differences in petrogenesis in terms of mantle mineralogy, degree of partial melting, composition of subduction components, and the nature of pre-subduction lithosphere. It is likely that, on a regional scale, the initiation of subduction involved subducted crust and lithospheric mantle wedge of a range of ages and compositions, as might be expected in this type of tectonic setting

Annotating genericity: a survey, a scheme, and a corpus

Generics are linguistic expressions that make statements about or refer to kinds, or that report regularities of events. Non-generic expressions make statements about particular individuals or specific episodes. Generics are treated extensively in semantic theory (Krifka et al., 1995). In practice, it is often hard to decide whether a referring expression is generic or non-generic, and to date there is no data set which is both large and satisfactorily annotated. Such a data set would be valuable for creating automatic systems for identifying generic expressions, in turn facilitating knowledge extraction from natural language text. In this paper we provide the next steps for such an annotation endeavor. Our contributions are: (1) we survey the most important previous projects annotating genericity, focusing on resources for English; (2) with a new agreement study we identify problems in the annotation scheme of the largest currently available resource (ACE-2005); and (3) we introduce a linguistically-motivated annotation scheme for marking both clauses and their subjects with regard to their genericity. (4) We present a corpus of MASC (Ide et al., 2010) and Wikipedia texts annotated according to our scheme, achieving substantial agreement

A clinical guide to the management of genitourinary symptoms in breast cancer survivors on endocrine therapy.

There is increasing attention and concern about managing the adverse effects of adjuvant endocrine therapy for women with early breast cancer as the side effects of therapy influence compliance and can impair quality of life (QoL). Most side effects associated with tamoxifen (TAM) and aromatase inhibitors (AIs) are directly related to estrogen deprivation, and the symptoms are similar to those experienced during natural menopause but appear to be more severe than that seen in the general population. Prolonged estrogen deprivation may lead to atrophy of the vulva, vagina, lower urinary tract and supporting pelvic structures, resulting in a range of genitourinary symptoms that can in turn lead to pain, discomfort, impairment of sexual function and negatively impact on multiple domains of QoL. The genitourinary side effects may be prevented, reduced and managed in most cases but this requires early recognition and appropriate treatment. We provide an overview of practical clinical approaches to understanding the pathophysiology and the management of genitourinary symptoms in postmenopausal women receiving adjuvant endocrine therapy for breast cancer

Core strength: A new model for injury prediction and prevention

OBJECTIVE: Many work in injury prone awkward positions that require adequate flexibility and strength in trunk stabilizer muscle groups. Performance on a functional movement screen (FMS) that assessed those factors was conducted and an intervention was designed. METHODS: A battery of FMS tests were performed on 433 firefighters. We analyzed the correlation between FMS performance and injuries and other selected parameters. An intervention to improve flexibility and strength in trunk stabilizer or core muscle groups through a training program was evaluated. RESULTS: The intervention reduced lost time due to injuries by 62% and the number of injuries by 42% over a twelve month period as compared to a historical control group. CONCLUSION: These findings suggest that core strength and functional movement enhancement programs to prevent injuries in workers whose work involves awkward positions is warranted