The composition and weathering of the continents over geologic time

The composition of continental crust records the balance between construction by tectonics and destruction by physical and chemical erosion. Quantitative constraints on how igneous addition and chemical weathering have modified the continents’ bulk composition are essential for understanding the evolution of geodynamics and climate. Using novel data analytic techniques we have extracted temporal trends in sediments’ protolith composition and weathering intensity from the largest available compilation of sedimentary major element compositions: ∼15,000 samples from 4.0 Ga to the present. We find that the average Archean upper continental crust was silica-rich and had a similar compositional diversity to modern continents. This is consistent with an early Archean, or earlier, onset of plate tectonics. In the Archean, chemical weathering sequestered ∼25 % more CO2 per mass eroded for the same weathering intensity than in subsequent time periods, consistent with carbon mass balance despite higher Archean outgassing rates and more limited continental exposure. Since 2.0 Ga, over long (>0.5 Gyr) timescales, crustal weathering intensity has remained relatively constant. On shorter timescales over the Phanerozoic, weathering intensity is correlated to global climate state, consistent with a weathering feedback acting in response to changes in CO2 sources or sinks

Variation in neurosurgical management of traumatic brain injury

Background: Neurosurgical management of traumatic brain injury (TBI) is challenging, with only low-quality evidence. We aimed to explore differences in neurosurgical strategies for TBI across Europe. Methods: A survey was sent to 68 centers participating in the Collaborative European Neurotrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. The questionnaire contained 21 questions, including the decision when to operate (or not) on traumatic acute subdural hematoma (ASDH) and intracerebral hematoma (ICH), and when to perform a decompressive craniectomy (DC) in raised intracranial pressure (ICP). Results: The survey was completed by 68 centers (100%). On average, 10 neurosurgeons work in each trauma center. In all centers, a neurosurgeon was available within 30 min. Forty percent of responders reported a thickness or volume threshold for evacuation of an ASDH. Most responders (78%) decide on a primary DC in evacuating an ASDH during the operation, when swelling is present. For ICH, 3% would perform an evacuation directly to prevent secondary deterioration and 66% only in case of clinical deterioration. Most respondents (91%) reported to consider a DC for refractory high ICP. The reported cut-off ICP for DC in refractory high ICP, however, differed: 60% uses 25 mmHg, 18% 30 mmHg, and 17% 20 mmHg. Treatment strategies varied substantially between regions, specifically for the threshold for ASDH surgery and DC for refractory raised ICP. Also within center variation was present: 31% reported variation within the hospital for inserting an ICP monitor and 43% for evacuating mass lesions. Conclusion: Despite a homogeneous organization, considerable practice variation exists of neurosurgical strategies for TBI in Europe. These results provide an incentive for comparative effectiveness research to determine elements of effective neurosurgical care

Patterns of coping and psychological adjustment in women with early breast cancer

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN009099 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Neoplasmas da bexiga associados à hematúria enzoótica bovina Urinary bladder neoplasms associated with bovine enzootic hematuria

Relatam-se três casos de hematúria enzoótica bovina (HEB) em animais provenientes do município de Jaguari, RS, Brasil. As pastagens de todas as propriedades de origem estavam altamente infestadas por samambaia (Pteridium aquilinum). Três bovinos, com idades entre 4 e 7 anos, apresentaram sinais clínicos que incluíam emagrecimento progressivo, hematúria intermitente e palidez das mucosas. As principais lesões foram observadas na bexiga e consistiam de três tipos de neoplasmas: hemangioma capilar, hemangiossarcoma e carcinoma de células escamosas. A epidemiologia, os sinais clínicos e as lesões macroscópicas e microscópicas observadas nos três bovinos são consistentes com o diagnóstico de HEB.<br>Three cases of bovine enzootic hematuria (BHE) are described in cattle from the municipality of Jaguari, Rio Grande do Sul, Brazil. The pastures of all affected farms were highly infested with bracken fern (Pteridium aquilinum). Three 4-7-year-old bovine had clinical signs of progressive weight loss, intermittent hematuria, and mucosal pallor. The main lesions were observed in the urinary bladder and consisted of three types of neoplasms: capillary hemangioma, hemangiosarcoma, and squamous cell carcinoma. The epidemiology, the clinical signs, and the gross and microscopic lesions observed in all three bovine were of BHE