881 research outputs found
Seagrass can mitigate negative ocean acidification effects on calcifying algae
The ultimate effect that ocean acidification (OA) and warming will have on the physiology of calcifying algae is still largely uncertain. Responses depend on the complex interactions between seawater chemistry, global/local stressors and species-specific physiologies. There is a significant gap regarding the effect that metabolic interactions between coexisting species may have on local seawater chemistry and the concurrent effect of OA. Here, we manipulated CO2 and temperature to evaluate the physiological responses of two common photoautotrophs from shallow tropical marine coastal ecosystems in Brazil: the calcifying alga Halimeda cuneata, and the seagrass Halodule wrightii. We tested whether or not seagrass presence can influence the calcification rate of a widespread and abundant species of Halimeda under OA and warming. Our results demonstrate that under elevated CO2, the high photosynthetic rates of H. wrightii contribute to raise H. cuneata calcification more than two-fold and thus we suggest that H. cuneata populations coexisting with H. wrightii may have a higher resilience to OA conditions. This conclusion supports the more general hypothesis that, in coastal and shallow reef environments, the metabolic interactions between calcifying and non-calcifying organisms are instrumental in providing refuge against OA effects and increasing the resilience of the more OA-susceptible species.E.B. would like to thank the Coordenação de Aperfeiçoamento de Pessoas de Nível Superior (CAPES) for Masters
funding. Funding for this project came from the Synergism grant (CNPq 407365/2013-3). We extend our thanks
to the Brazil-based Projeto Coral Vivo and its sponsor PetroBras Ambiental for providing the Marine Mesocosm
structure and experimental assistance.info:eu-repo/semantics/publishedVersio
Rapidly rotating second-generation progenitors for the blue hook stars of {\omega} Cen
Horizontal Branch stars belong to an advanced stage in the evolution of the
oldest stellar galactic population, occurring either as field halo stars or
grouped in globular clusters. The discovery of multiple populations in these
clusters, that were previously believed to have single populations gave rise to
the currently accepted theory that the hottest horizontal branch members (the
blue hook stars, which had late helium-core flash ignition, followed by deep
mixing) are the progeny of a helium-rich "second generation" of stars. It is
not known why such a supposedly rare event (a late flash followed by mixing) is
so common that the blue hook of {\omega} Cen contains \sim 30% of horizontal
branch stars 10 , or why the blue hook luminosity range in this massive cluster
cannot be reproduced by models. Here we report that the presence of helium core
masses up to \sim 0.04 solar masses larger than the core mass resulting from
evolution is required to solve the luminosity range problem. We model this by
taking into account the dispersion in rotation rates achieved by the
progenitors, whose premain sequence accretion disc suffered an early disruption
in the dense environment of the cluster's central regions where
second-generation stars form. Rotation may also account for frequent
late-flash-mixing events in massive globular clusters.Comment: 44 pages, 8 figures, 2 tables in Nature, online june 22, 201
High-Contrast Observations in Optical and Infrared Astronomy
High-contrast observations in optical and infrared astronomy are defined as
any observation requiring a technique to reveal a celestial object of interest
that is in such close angular proximity to another source brighter by a factor
of at least 10^5 that optical effects hinder or prevent the collection of
photons directly from the target of observation. This is a relatively new type
of observation that enables research on previously obscured parts of the
Universe. In particular, it is most applicable to Comparative Planetary
Science, a field that directly attacks such questions as "how common are
planetary systems? What types of planets exist, and are there planets other
than Earth that are capable of supporting life as we know it?" We survey the
scientific motivations for high-contrast observations, provide an overview of
the techniques currently being used or developed, and discuss some ideas and
studies for future prospects.Comment: In press for Annual Review of Astronomy and Astrophysics (Vol. 47).
46 pages, 15 figure
"I am your mother and your father!": In vitro derived gametes and the ethics of solo reproduction
In this paper, we will discuss the prospect of human reproduction achieved with gametes originating from only one person. According to statements by a minority of scientists working on the generation of gametes in vitro, it may become possible to create eggs from men’s non-reproductive cells and sperm from women’s. This would enable, at least in principle, the creation of an embryo from cells obtained from only one individual: ‘solo reproduction’. We will consider what might motivate people to reproduce in this way, and the implications that solo reproduction might have for ethics and policy. We suggest that such an innovation is unlikely to revolutionise reproduction and parenting. Indeed, in some respects it is less revolutionary than in vitro fertilisation as a whole. Furthermore, we show that solo reproduction with in vitro created gametes is not necessarily any more ethically problematic than gamete donation—and probably less so. Where appropriate, we draw parallels with the debate surrounding reproductive cloning. We note that solo reproduction may serve to perpetuate reductive geneticised accounts of reproduction, and that this may indeed be ethically questionable. However, in this it is not unique among other technologies of assisted reproduction, many of which focus on genetic transmission. It is for this reason that a ban on solo reproduction might be inconsistent with continuing to permit other kinds of reproduction that also bear the potential to strengthen attachment to a geneticised account of reproduction. Our claim is that there are at least as good reasons to pursue research towards enabling solo reproduction, and eventually to introduce solo reproduction as an option for fertility treatment, as there are to do so for other infertility related purposes
Incidence of intussusception in Singaporean children aged less than 2 years: A hospital-based prospective study
10.1186/1471-2431-13-161BMC Pediatrics131-BPME
Lysyl oxidase-like 2 (LOXL2), a new regulator of cell polarity required for metastatic dissemination of basal-like breast carcinomas
Basal-like breast carcinoma is characterized by the expression of basal/
myoepithelial markers, undifferentiated phenotype, highly aggressive behaviour
and frequent triple negative status (ESR , PR , Her2neu ). We have previously
shown that epithelial–mesenchymal transition (EMT) occurs in basal-like breast
tumours and identified Lysyl-oxidase-like 2 (LOXL2) as an EMT player and poor
prognosis marker in squamous cell carcinomas. We now show that LOXL2 mRNA is
overexpressed in basal-like human breast carcinomas. Breast carcinoma cell lines
with basal-like phenotype show a specific cytoplasmic/perinuclear LOXL2 expression,
and this subcellular distribution is significantly associated with distant
metastatic incidence in basal-like breast carcinomas. LOXL2 silencing in
basal-like carcinoma cells induces a mesenchymal-epithelial transition (MET)
associated with a decrease of tumourigenicity and suppression of metastatic
potential. Mechanistic studies indicate that LOXL2 maintains the mesenchymal
phenotype of basal-like carcinoma cells by a novel mechanism involving transcriptional
downregulation of Lgl2 and claudin1 and disorganization of cell
polarity and tight junction complexes. Therefore, intracellular LOXL2 is a new
candidate marker of basal-like carcinomas and a target to block metastatic
dissemination of this aggressive breast tumour subtypeThis work was supported by
grants from the Spanish Ministry of Science and Innovation,
MICINN, (SAF2007-53061; SAF2010-21143; Consolider Ingenio
CSD2007/00017, to AC; SAF2007-63075; SAF2010-20175 to
GM-B); Fundacion Mutua Madrileña (2007, 2009 to AC and
GM-B); Instituto de Salud Carlos III (ISCIII) (PI 080971 to JP),
and Junta de Andalucıa (PI-0384/2007; PI 080971, P07-CVI-
03100 to JP). FS and A Martı´n are recipients of JAE-pre and
JAE-postdoc contracts from the Spanish Research Council
(CSIC), respectively; MAC is founded by the RETICS (ISCIII)
Shifts in soil ammonia-oxidizing community maintain the nitrogen stimulation of nitrification across climatic conditions
This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: The data that support the findings of this study are openly available in Figshare at https://doi.org/10.6084/m9.figshare.20022878 (Zhang, Cheng, et al., 2023).Anthropogenic nitrogen (N) loading alters soil ammonia-oxidizing archaea (AOA) and bacteria (AOB) abundances, likely leading to substantial changes in soil nitrification. However, the factors and mechanisms determining the responses of soil AOA:AOB and nitrification to N loading are still unclear, making it difficult to predict future changes in soil nitrification. Herein, we synthesize 68 field studies around the world to evaluate the impacts of N loading on soil ammonia oxidizers and nitrification. Across a wide range of biotic and abiotic factors, climate is the most important driver of the responses of AOA:AOB to N loading. Climate does not directly affect the N-stimulation of nitrification, but does so via climate-related shifts in AOA:AOB. Specifically, climate modulates the responses of AOA:AOB to N loading by affecting soil pH, N-availability and moisture. AOB play a dominant role in affecting nitrification in dry climates, while the impacts from AOA can exceed AOB in humid climates. Together, these results suggest that climate-related shifts in soil ammonia-oxidizing community maintain the N-stimulation of nitrification, highlighting the importance of microbial community composition in mediating the responses of the soil N cycle to N loading.National Natural Science Foundation of ChinaEuropean Union Horizon 2020Aarhus University Research FoundationDanish Independent Research FoundationNordic Committee of Agriculture and Food ResearchNatural Environment Research Council (NERC)Pioneer Center for Research in Sustainable Agricultural Futures (Land-CRAFT)DNR
Advances in hormone replacement therapy: making the menopause manageable
The importance of the results of some large, randomized controlled trials (RCTs) on Hormone Replacement Therapy (HRT) has modified the risk/benefit perception of HRT. Recent literature review supports a different management
Decision making under uncertainty in environmental projects using mathematical simulation modeling
The final publication is available at Springer via http://dx.doi.org/10.1007/s12665-016-6135-yIn decision-making processes, reliability and risk aversion play a decisive role. The aim of this study is to perform an uncertainty assessment of the effects of future scenarios of sustainable groundwater pumping strategies on the quantitative and chemical status of an aquifer. The good status of the aquifer is defined according to the terms established by the EU Water Framework Directive (WFD). A decision support systems (DSS) is presented, which makes use of a stochastic inverse model (GC method) and geostatistical approaches to calibrate equally likely realizations of hydraulic conductivity (K) fields for a particular case study. These K fields are conditional to available field data, including hard and soft information. Then, different future scenarios of groundwater pumping strategies are generated, based on historical information and WFD standards, and simulated for each one of the equally likely K fields. The future scenarios lead to different environmental impacts and levels of socioeconomic development of the region and, hence, to a different degree of acceptance among stakeholders. We have identified the different stakeholders implied in the decision-making process, the objectives pursued and the alternative actions that should be considered by stakeholders in a public participation project (PPP). The MonteCarlo simulation provides a highly effective way for uncertainty assessment and allows presenting the results in a simple and understandable way even for non-experts stakeholders. The methodology has been successfully applied to a real case study and lays the foundations to performa PPP and stakeholders' involvement in a decisionmaking process as required by the WFD. The results of the methodology can help the decision-making process to come up with the best policies and regulations for a groundwater system under uncertainty in groundwater parameters and management strategies and involving stakeholders with conflicting interests.Llopis Albert, C.; Palacios Marqués, D.; Merigó -Lindahl, JM. (2016). Decision making under uncertainty in environmental projects using mathematical simulation modeling. Environmental Earth Sciences. 75(19):1-11. doi:10.1007/s12665-016-6135-yS1117519Arhonditsis GB, Perhar G, Zhang W, Massos E, Shi M, Das A (2008) Addressing equifinality and uncertainty in eutrophication models. Water Resour Res 44:W01420. doi: 10.1029/2007WR005862Capilla JE, Llopis-Albert C (2009) Gradual conditioning of non-gaussian transmissivity fields to flow and mass transport data. 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BRCA1 tumours correlate with a HIF-1α phenotype and have a poor prognosis through modulation of hydroxylase enzyme profile expression
BACKGROUND: There are limited data regarding the hypoxia pathway in familial breast cancers. We therefore performed a study of hypoxic factors in BRCA1, BRCA2 and BRCAX breast cancers. METHODS: Immunoperoxidase staining for HIF-1alpha, PHD1, PHD2, PHD3, VEGF and FIH was carried out in 125 (38 BRCA1, 33 BRCA2 and 54 BRCAX) breast carcinomas. These were correlated with clinicopathological parameters and the intrinsic breast cancer phenotypes. RESULTS: BRCA1 tumours correlated with positivity for HIF-1alpha (P=0.008) and negativity for PHD3 (P=0.037). HIF-1alpha positivity (P=0.001), PHD3 negativity (P=0.037) and nuclear FIH negativity (P=0.011) was associated with basal phenotype. HIF-1alpha expression correlated with high tumour grade (P=0.009), negative oestrogen receptor (ER) status (P=0.001) and the absence of lymph node metastasis (P=0.028). Nuclear FIH expression and PHD3 correlated with positive ER expression (P=0.024 and P=0.035, respectively). BRCA1 cancers with positive HIF-1alpha or cytoplasmic FIH had a significantly shorter relapse-free survival (P=0.007 and P=0.049, respectively). CONCLUSIONS: The aggressive nature of BRCA1 and basal-type tumours may be partly explained by an enhanced hypoxic drive and hypoxia driven ER degradation because of suppressed PHD and aberrantly located FIH expression. This may have important implications, as these tumours may respond to compounds directed against HIF-1alpha or its downstream targets
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