235 research outputs found

    Menus for Feeding Black Holes

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    Black holes are the ultimate prisons of the Universe, regions of spacetime where the enormous gravity prohibits matter or even light to escape to infinity. Yet, matter falling toward the black holes may shine spectacularly, generating the strongest source of radiation. These sources provide us with astrophysical laboratories of extreme physical conditions that cannot be realized on Earth. This chapter offers a review of the basic menus for feeding matter onto black holes and discusses their observational implications.Comment: 27 pages. Accepted for publication in Space Science Reviews. Also to appear in hard cover in the Space Sciences Series of ISSI "The Physics of Accretion onto Black Holes" (Springer Publisher

    ACCERT: Auckland's cancer cachexia evaluating resistance training study

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    Background: Cancer Cachexia (CC) is a common problem seen in many advanced malignancies including Non- Small-Cell Lung Cancer (NSCLC). In CC there is a significant loss of adipose tissue and skeletal muscle mass. Muscle wasting is the main cause of impaired function, leading to respiratory complications and fatigue. The optimal treatment for CC is the complete removal of the tumour; unfortunately with advanced NSCLC this is unachievable. The next best options are to increase nutritional intake to counteract weight loss, address the anorexia, inflammation, and metabolic alterations i.e. loss of body fat and the skeletal muscle wasting. This requires the need to utilise a multi-targeted approach to decrease the inflammation and to stimulate the skeletal anabolic pathways with the use of progressive resistance training (PRT). PRT has shown acceptability and benefits in other cancer populations. This study aims to identify a novel multi-targeted treatment regimen that will alleviate and/or stabilise CC weight loss. Methods: This is a randomised, open-label study to investigate whether 2 sessions each week of PRT followed by essential amino acids (EAA's) high in leucine, when administered in addition to Eicosapentaenoic Acid (EPA) and a Cox-2 inhibitor is acceptable to NSCLC cachectic patients for a period of 20 weeks (primary endpoint). Secondary endpoints include Lean Body Mass, MRI thigh skeletal muscle values, QoL and Fatigue questionnaires, serum pro-inflammatory cytokine profiles, and hand and leg strength. Safety data will also be collected. Outcome measures to power a future study will be determined from the trend in difference between the two groups. 21 patients are planned to be randomised in a 1:2 ratio Arm A EPA and Cox-2 inhibitor vs. Arm B EPA, Cox-2 inhibitor, PRT followed by EAA's. All patients are offered to continue with the study medications and/or PRT sessions on compassionate use. Main inclusion criteria include: histological proven NSCLC patients who have at least 5% weight loss and fulfil the following cachectic definition (Evans Clin Nut 2008 27). A guest patient was enrolled in May 2012, followed by study participants in June 201

    Expedition 369 summary

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    The tectonic and paleoceanographic setting of the Great Australian Bight (GAB) and the Mentelle Basin (adjacent to Naturaliste Plateau) offered an opportunity to investigate Cretaceous and Cenozoic climate change and ocean dynamics during the last phase of breakup among remnant Gondwana continents. Sediment recovered from sites in both regions during International Ocean Discovery Program Expedition 369 will provide a new perspective on Earth’s temperature variation at subpolar latitudes (60°–62°S) across the extremes of the mid-Cretaceous hot greenhouse climate and the cooling that followed. Basalts and prebreakup sediments were also recovered and will provide constraints regarding the type and age of the Mentelle Basin basement and processes operating during the break up of Gondwana. The primary goals of the expedition were to • Investigate the timing and causes for the rise and collapse of the Cretaceous hot greenhouse climate and how this climate mode affected the climate–ocean system and oceanic biota; • Determine the relative roles of productivity, ocean temperature, and ocean circulation at high southern latitudes during Cretaceous oceanic anoxic events (OAEs); • Investigate potential source regions for deep-water and intermediate-water masses in the southeast Indian Ocean and how these changed during Gondwana breakup; • Characterize how oceanographic conditions at the Mentelle Basin changed during the Cenozoic opening of the Tasman Gateway and restriction of the Indonesian Gateway; and • Resolve questions on the volcanic and sedimentary origins of the Australo-Antarctic Gulf and Mentelle Basin and provide stratigraphic control on the age and nature of the prebreakup successions. Hole U1512A in the GAB recovered a 691 m thick sequence of black claystone ranging from the lower Turonian to the lower Campanian. Age control is primarily based on calcareous nannofossils, but the presence of other microfossil groups provided consistent low-resolution control. Despite the lithologic uniformity, long- and short-term variations in natural gamma radiation and magnetic susceptibility show cyclic alternations that suggest an orbital control of sediment deposition, which will be useful for developing an astrochronology for the sequence. Sites U1513, U1514, U1515, and U1516 were drilled in water depths between 850 and 3900 m in the Mentelle Basin and penetrated 774, 517, 517, and 542 meters below seafloor, respectively. Under a thin layer of Pleistocene to upper Miocene sediment, Site U1513 cored a succession of Cretaceous units from the Campanian to the Valanginian, as well as a succession of basalts. Site U1514 sampled an expanded Pleistocene to Eocene sequence and terminated in the upper Albian. The Cenomanian to Turonian interval at Site U1514 is represented by deformed sedimentary rocks that probably represent a detachment zone. Site U1515 is located on the west Australian margin at 850 m water depth and was the most challenging site to core because much of the upper 350 m was either chert or poorly consolidated sand. However, the prebreakup Jurassic(?) sediments interpreted from the seismic profiles were successfully recovered. Site U1516 cored an expanded Pleistocene, Neogene, and Paleogene section and recovered a complete Cenomanian/Turonian boundary interval containing five layers with high organic carbon content. Study of the well-preserved calcareous microfossil assemblages from different paleodepths will enable generation of paleotemperature and biotic records that span the rise and collapse of the Cretaceous hot greenhouse (including OAEs 1d and 2), providing insight to resultant changes in deep-water and surface water circulation that can be used to test predictions from earth system models. Measurements of paleotemperature proxies and other data will reveal the timing, magnitude, and duration of peak hothouse conditions and any cold snaps that could have allowed growth of a polar ice sheet. The sites contain a record of the mid-Eocene to early Oligocene opening of the Tasman Gateway and the Miocene to Pliocene restriction of the Indonesian Gateway; both passages have important effects on global oceanography and climate. Advancing understanding of the paleoceanographic changes in a regional context will provide a global test on models of Cenomanian to Turonian oceanographic and climatic evolution related both to extreme Turonian warmth and the evolution of OAE 2. The Early Cretaceous volcanic rocks and underlying Jurassic(?) sediments cored in different parts of the Mentelle Basin provide information on the timing of different stages of the Gondwana breakup. The recovered cores provide sufficient new age constraints to underpin a reevaluation of the basin-wide seismic stratigraphy and tectonic models for the region

    Expedition 369 methods

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    This chapter documents the procedures and methods used in the shipboard laboratories during International Ocean Discovery Program (IODP) Expedition 369. This introductory section in particular provides a rationale for the site locations and an overview of IODP depth conventions, curatorial procedures, and general core handling/analyses during Expedition 369. Subsequent sections describe specific laboratory procedures and instruments in more detail. This information only applies to shipboard work described in the Proceedings volume; methods used in shore-based analyses of Expedition 369 samples and/or data will be described in various scientific contributions in the open peer-reviewed literature and the Expedition Research Results chapters of this Proceedingsvolume

    New insights into the genetic etiology of Alzheimer's disease and related dementias

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    Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele
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