254 research outputs found
Transient increase of raf protein kinase-like immunoreactivity in the rat dentate gyrus during long-term potentiation.
Oxygen minimum zone-type biogeochemical cycling in the Cenomanian-Turonian Proto-North Atlantic across Oceanic Anoxic Event 2
Highlights
âą We present a 5 myr record of biogeochemical cycling in a Cretaceous upwelling area.
âą A novel quantitative approach for the evaluation of Fe speciation proxies was applied.
âą Ferruginous proxy signature reflects intense chemical weathering rather than anoxia.
âą Water column redox conditions evolved from oxic to nitrogenous to euxinic before OAE2.
âą Smaller seawater nitrate inventory facilitated sedimentary H2S release and euxinia.
Abstract
Oceanic Anoxic Events (OAEs) in Earth's history are regarded as analogues for current and future ocean deoxygenation, potentially providing information on its pacing and internal dynamics. In order to predict the Earth system's response to changes in greenhouse gas concentrations and radiative forcing, a sound understanding of how biogeochemical cycling differs in modern and ancient marine environments is required. Here, we report proxy records for iron (Fe), sulfur and nitrogen cycling in the Tarfaya upwelling system in the Cretaceous Proto-North Atlantic before, during and after OAE2 (âŒ93 Ma). We apply a novel quantitative approach to sedimentary Fe speciation, which takes into account the influence of terrigenous weathering and sedimentation as well as authigenic Fe (non-terrigenous, precipitated onsite) rain rates on Fe-based paleo-redox proxies. Generally elevated ratios of reactive Fe (i.e., bound to oxide, carbonate and sulfide minerals) to total Fe (FeHR/FeT) throughout the 5 million year record are attributed to transport-limited chemical weathering under greenhouse climate conditions. Trace metal and nitrogen isotope systematics indicate a step-wise transition from oxic to nitrogenous to euxinic conditions over several million years prior to OAE2. Taking into consideration the low terrigenous sedimentation rates in the Tarfaya Basin, we demonstrate that highly elevated FeHR/FeT from the mid-Cenomanian through OAE2 were generated with a relatively small flux of additional authigenic Fe. Evaluation of mass accumulation rates of reactive Fe in conjunction with the extent of pyritization of reactive Fe reveals that authigenic Fe and sulfide precipitation rates in the Tarfaya Basin were similar to those in modern upwelling systems. Because of a smaller seawater nitrate inventory, however, chemolithoautotrophic sulfide oxidation with nitrate was less efficient in preventing hydrogen sulfide release into the water column. As terrigenous weathering and sediment flux determine how much authigenic Fe is required to generate an anoxic euxinic or ferruginous proxy signature, we emphasize that both have to be taken into account when interpreting Fe-based paleo-redox proxies
can concomitant diseases predict the compliance with cisplatin plus rt in patients with la scchn an exploratory endpoint analysis of the comply trial
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Functional Contribution and Targeted Migration of Group-2 Innate Lymphoid Cells in Inflammatory Lung Diseases: Being at the Right Place at the Right Time
During the last decade, group-2 innate lymphoid cells (ILC2s) have been discovered and successfully established as crucial mediators of lung allergy, airway inflammation and fibrosis, thus affecting the pathogenesis and clinical course of many respiratory diseases, like for instance asthma, cystic fibrosis and chronic rhinosinusitis. As an important regulatory component in this context, the local pulmonary milieu at inflammatory tissue sites does not only determine the activation status of lung-infiltrating ILC2s, but also influences their motility and migratory behavior. In general, many data collected in recent murine and human studies argued against the former concept of a very strict tissue residency of innate lymphoid cells (ILCs) and instead pointed to a context-dependent homing capacity of peripheral blood ILC precursors and the inflammation-dependent capacity of specific ILC subsets for interorgan trafficking. In this review article, we provide a comprehensive overview of the so far described molecular mechanisms underlying the pulmonary migration of ILC2s and thereby the numeric regulation of local ILC2 pools at inflamed or fibrotic pulmonary tissue sites and discuss their potential to serve as innovative therapeutic targets in the treatment of inflammatory lung diseases
Specific Heat Study of 1D and 2D Excitations in the Layered Frustrated Quantum Antiferromagnets CsCuClBr
We report an experimental and theoretical study of the low-temperature
specific heat and magnetic susceptibility of the layered anisotropic
triangular-lattice spin-1/2 Heisenberg antiferromagnets
CsCuClBr with = 0, 1, 2, and 4. We find that the ratio
of the exchange couplings ranges from 0.32 to , implying a
change (crossover or quantum phase transition) in the materials' magnetic
properties from one-dimensional (1D) behavior for to
two-dimensional (2D) behavior for behavior. For , realized for = 0, 1, and 4, we find a magnetic contribution to the
low-temperature specific heat, , consistent with spinon
excitations in 1D spin-1/2 Heisenberg antiferromagnets. Remarkably, for =
2, where implies a 2D magnatic character, we also observe
. This finding, which contrasts the prediction of made by standard spin-wave theories, shows that Fermi-like
statistics also plays a significant role for the magnetic excitations in
frustrated spin-1/2 2D antiferromagnets
Health status, use of healthcare, and socio-economic implications of cancer survivorship in Portugal : results from the fourth national health survey
Health status, use of healthcare, and socio-economic implications of cancer survivorship in Portugal: results from the Fourth National Health SurveyUnderstanding the morbidity and socio-economic implications of cancer survivorship is essential for a comprehensive management of oncological diseases. We compared cancer survivors (CS) with the general population regarding health status, use of healthcare resources and socio-economic condition.
We analyzed data from a representative sample of the Portuguese population aged a parts per thousand yen15 years (n = 35,229). We defined three groups of CS, according to the time since diagnosis and the latest cancer treatment: CS 1 diagnosis within 12 months of interview; CS 2 diagnosis more than 12 months before and treatment in the previous 12 months; CS 3 diagnosis and treatment more than 12 months before. These were compared with the general population, adjusting for differences in sex, age, and place of residence.
The prevalence of CS was 2.2 % (CS 1: 0.2 %; CS 2: 0.9 %, CS 3: 1.1 %). Self-perceived health status was worse among CS and short-time incapacity more frequent among CS 1 and CS 2. Health expenses were higher in the early stages of survivorship. Lower household income and financial difficulties were more frequent in CS 1 and CS 3 men, respectively.
This study confirmed the higher consumption of healthcare resources and worse financial situation among CS.
Our study provides valuable information for understanding the global impact of cancer survivorship.The authors thank the National Health Systems Observatory (Observatorio Nacional de Saude), National Institute of Health Dr. Ricardo Jorge (INSA), Ministry of Health and the National Institute of Statistics (INE) for providing the data (Ministerio da Saude, Instituto Nacional de Saude Dr. Ricardo Jorge; IP, Departamento de Epidemiologia/Instituto Nacional de Estatistica: Inquerito Nacional de Saude 2005/2006). Luis Pacheco-Figueiredo received a grant from the Fundacao para a Ciencia e a Tecnologia (SFRH/SINTD/60124/2009)
Inhibiting PGGT1B Disrupts Function of RHOA, Resulting in T-cell Expression of Integrin α4ÎČ7 and Development of Colitis in Mice
Fertility Ideals of Women and Men Across the Life Course
This paper explores the stability of womenâs and menâs fertility preferences across the life course. The data come from the first six waves of the German Family Panel (pairfam), which span the period from 2008/2009 until 2013/2014. In our analysis, fertility preferences are measured using the following question: âUnder ideal circumstances, how many children would you like to have?â The average number cited by both women and men is 2.2. With rising age, this number declines modestly. Relying on fixed-effects modelling, we find that neither partnership status nor economic circumstances have any causal effect on fertility preferences. However, as the number of children a respondent has increases, his or her ideal number of children is also likely to grow. Thus, fertility ideals appear to undergo changes over time, and are adjusted in line with the size of the respondentâs own family
Hadley circulation and precipitation changes control black shale deposition in the Late Jurassic Boreal Seaway
New climate simulations using the HadCM3L model with a paleogeography of the Late Jurassic [155.5âMa], and proxy-data corroborate that warm and wet tropical-like conditions reached as far north as the UK sector of the Jurassic Boreal Seaway [~35oN]. This is associated with a northern hemisphere Jurassic Hadley cell and an intensified subtropical jet which both extend significantly polewards than in the modern (July-September). Deposition of the Kimmeridge Clay Formation [KCF] occurred in the shallow, storm-dominated, epeiric Boreal Seaway. High resolution paleo-environmental proxy data from the Kimmeridge Clay Formation [KCF; ~155â150âMa], UK are used to test for the role of tropical atmospheric circulation on meter-scale heterogeneities in black shale deposition. Proxy and model data show that the most organic-rich section [eudoxus to mid-hudlestoni zones] is characterised by a positive ÎŽ13Corg excursion and up to 37âwt% total organic carbon [%TOC]. Orbital-modulation of organic carbon burial primarily in the long eccentricity power band combined with a clear positive correlation between %TOC carbonate-free and the kaolinite/illite ratio supports peak organic carbon burial under the influence of very humid climate conditions, similar to the modern tropics. This re-interpretation of large-scale climate relationships, supported by independent modelling and geological data, has profound implications for atmospheric circulation patterns and processes affecting marine productivity and organic carbon burial further north along the Boreal Seaway, including the Arctic
Foraminiferal assemblages as palaeoenvironmental bioindicators in Late Jurassic epicontinental platforms: relation with trophic conditions
Foraminiferal assemblages from the neritic environment reveal the palaeoecological impact of nutrient types in relation to shore distance and sedimentary setting. Comparatively proximal siliciclastic settings from the Boreal Domain (Brora section, Eastern Scotland) were dominated by innerâshelf primary production in the water column or in sea bottom, while in relatively seawards mixed carbonateâsiliciclastic settings from the Western Tethys (Prebetic, Southern Spain), nutrients mainly derived from the innerâshelf source. In both settings, benthic foraminiferal assemblages increased in diversity and proportion of epifauna from eutrophic to oligotrophic conditions. The proximal setting example (Brora Brick Clay Mb.) corresponds to Callovian offshore shelf deposits with a high primary productivity, bottom accumulation of organic matter, and a reduced sedimentation rate for siliciclastics. Eutrophic conditions favoured some infaunal foraminifera. Lately, inner shelf to shoreface transition areas (Fascally Siltstone Mb.), show higher sedimentation rates and turbidity, reducing euphoticâzone range depths and primary production, and then deposits with a lower organic matter content (highâmesotrophic conditions). This determined less agglutinated infaunal foraminifera content and increasing calcitic and aragonitic epifauna, and calcitic opportunists (i.e., Lenticulina). The comparatively distal setting of the Oxfordian example (Prebetic) corresponds to: (i) outerâshelf areas with lower nutrient input (relative oligotrophy) and organic matter accumulation on comparatively firmer substrates (lumpy lithofacies group) showing dominance of calcitic epifaunal foraminifera, and (ii) midâshelf areas with a higher sedimentation rate and nutrient influx (lowâmesotrophic conditions) favouring potentially deep infaunal foraminifers in comparatively unconsolidated and nutrientârich substrates controlled by instable redox boundary (marlâlimestone rhythmite lithofacies).This research was carried out with the financial support of projects CGL2005â06636âC0201 and CGL2005â01316/BTE, and University of Oslo, NorwayâStatoil cooperation. M.R. holds a Juan de la Cierva grant from the Ministry of Science and Technology of Spain
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