Distribuição do fitoplâncton no entorno da reserva biológica marinha do Arvoredo

Phytoplankton are one of the main components of marine aquatic systems and their distribution is influenced by several environmental factors, such as nutrients and light, in addition to temperature, turbidity and dissolved oxygen. The marine environment of the Santa Catarina platform is a subtropical, oligotrophic system. Bodies of water of oceanic origin modify the oceanographic conditions of the region (ACAS, APP, and continental contribution by PRT and CN) Despite the biological importance of this region, studies on the distribution and ecology of phytoplankton are scarce. Therefore, the objective of the present study is to evaluate the distribution of phytoplankton in the surroundings of the Arvoredo Marine Biological Reserve, over three consecutive years. This study is based on the MAArE project. Collections were carried out between 2014 and 2016, at six sampling stations and at three depths. Physical parameters were obtained in situ and chemicals collected in Van Dorn bottles for analysis of inorganic nutrients in suspension. Samples for quantitative analysis of phytoplankton, collected in a Van Dorn bottle and packaged in a 250 mL bottle, preserved in a 4% formaldehyde water solution. The identification and counting of the organisms was performed using an inverted optical microscope Olympus®, model CKX41, according to the classic Utermöhl method. High cell densities have been associated with high concentrations of silicate. During the summer, in coastal seasons, fertilization by this nutrient is under continental influence and ACAS intrusion in the deeper seasons and in winter by APP intrusion.O fitoplâncton constitui um dos principais componentes dos sistemas aquáticos marinhos e sua distribuição é influenciada por vários fatores ambientais, tais como, nutrientes e luz, além de temperatura, turbidez e oxigênio dissolvido. O ambiente marinho da plataforma de Santa Catarina é um sistema subtropical, oligotrófico. Massas de água de origem oceânica modificam as condições oceanográficas da região (ACAS, APP, e aporte continental por PRT e CN) Apesar da importância biológica dessa região, estudos sobre a distribuição e ecologia do fitoplâncton são escassos. Diante disso, o objetivo do presente estudo é avaliar a distribuição do fitoplanctônica no entorno da Reserva Biológica Marinha do Arvoredo, ao longo de três anos consecutivos. O presente estudo é baseado no projeto MAArE. Coletas foram realizadas entre os anos de 2014 a 2016, em seis estações de amostragem e em três profundidades. Parâmetros físicos foram obtidos in situ e químicos coletados em garrafas Van Dorn para análise dos nutrientes inorgânicos em suspensão. Amostras para análise quantitativa do fitoplâncton, coletados em garrafa Van Dorn e acondicionadas em frasco de 250 mL, preservadas em solução de água do mar-formaldeído a 4%. A identificação e contagem dos organismos foi realizada em microscópio ótico invertido Olympus®, modelo CKX41, segundo o método clássico de Utermöhl. Altas densidades celulares foram associadas as altas concentrações de Silicato. Durante o verão, nas estações costeiras, a fertilização por este nutriente está sob influência continental e intrusão da ACAS nas estações mais profundas e no inverno pelo intrusão APP

BET bromodomain protein inhibition is a therapeutic option for medulloblastoma

Medulloblastoma is the most common malignant brain tumor of childhood, and represents a significant clinical challenge in pediatric oncology, since overall survival currently remains under 70%. Patients with tumors overexpressing MYC or harboring a MYC oncogene amplification have an extremely poor prognosis. Pharmacologically inhibiting MYC expression may, thus, have clinical utility given its pathogenetic role in medulloblastoma. Recent studies using the selective small molecule BET inhibitor, JQ1, have identified BET bromodomain proteins, especially BRD4, as epigenetic regulatory factors for MYC and its targets. Targeting MYC expression by BET inhibition resulted in antitumoral effects in various cancers. Our aim here was to evaluate the efficacy of JQ1 against preclinical models for high-risk MYC-driven medulloblastoma. Treatment of medulloblastoma cell lines with JQ1 significantly reduced cell proliferation and preferentially induced apoptosis in cells expressing high levels of MYC. JQ1 treatment of medulloblastoma cell lines downregulated MYC expression and resulted in a transcriptional deregulation of MYC targets, and also significantly altered expression of genes involved in cell cycle progression and p53 signalling. JQ1 treatment prolonged the survival of mice harboring medulloblastoma xenografts and reduced the tumor burden in these mice. Our preclinical data provide evidence to pursue testing BET inhibitors, such as JQ1, as molecular targeted therapeutic options for patients with high-risk medulloblastomas overexpressing MYC or harboring MYC amplifications

Targeting tachykinin receptors in neuroblastoma

Neuroblastoma is the most common extracranial tumor in children. Despite aggressive multimodal treatment, high-risk neuroblastoma remains a clinical challenge with survival rates below 50%. Adding targeted drugs to first-line therapy regimens is a promising approach to improve survival in these patients. TACR1 activation by substance P has been reported to be mitogenic in cancer cell lines. Tachykinin receptor (TACR1) antagonists are approved for clinical use as an antiemetic remedy since 2003. Tachykinin receptor inhibition has recently been shown to effectively reduce growth of several tumor types. Here, we report that neuroblastoma cell lines express TACR1, and that targeting TACR1 activity significantly reduced cell viability and induced apoptosis in neuroblastoma cell lines. Gene expression profiling revealed that TACR1 inhibition repressed E2F2 and induced TP53 signaling. Treating mice harboring established neuroblastoma xenograft tumors with Aprepitant also significantly reduced tumor burden. Thus, we provide evidence that the targeted inhibition of tachykinin receptor signaling shows therapeutic efficacy in preclinical models for high-risk neuroblastoma

Design of a multi-signature ensemble classifier predicting neuroblastoma patients' outcome

<p>Abstract</p> <p>Background</p> <p>Neuroblastoma is the most common pediatric solid tumor of the sympathetic nervous system. Development of improved predictive tools for patients stratification is a crucial requirement for neuroblastoma therapy. Several studies utilized gene expression-based signatures to stratify neuroblastoma patients and demonstrated a clear advantage of adding genomic analysis to risk assessment. There is little overlapping among signatures and merging their prognostic potential would be advantageous. Here, we describe a new strategy to merge published neuroblastoma related gene signatures into a single, highly accurate, Multi-Signature Ensemble (MuSE)-classifier of neuroblastoma (NB) patients outcome.</p> <p>Methods</p> <p>Gene expression profiles of 182 neuroblastoma tumors, subdivided into three independent datasets, were used in the various phases of development and validation of neuroblastoma NB-MuSE-classifier. Thirty three signatures were evaluated for patients' outcome prediction using 22 classification algorithms each and generating 726 classifiers and prediction results. The best-performing algorithm for each signature was selected, validated on an independent dataset and the 20 signatures performing with an accuracy > = 80% were retained.</p> <p>Results</p> <p>We combined the 20 predictions associated to the corresponding signatures through the selection of the best performing algorithm into a single outcome predictor. The best performance was obtained by the Decision Table algorithm that produced the NB-MuSE-classifier characterized by an external validation accuracy of 94%. Kaplan-Meier curves and log-rank test demonstrated that patients with good and poor outcome prediction by the NB-MuSE-classifier have a significantly different survival (p < 0.0001). Survival curves constructed on subgroups of patients divided on the bases of known prognostic marker suggested an excellent stratification of localized and stage 4s tumors but more data are needed to prove this point.</p> <p>Conclusions</p> <p>The NB-MuSE-classifier is based on an ensemble approach that merges twenty heterogeneous, neuroblastoma-related gene signatures to blend their discriminating power, rather than numeric values, into a single, highly accurate patients' outcome predictor. The novelty of our approach derives from the way to integrate the gene expression signatures, by optimally associating them with a single paradigm ultimately integrated into a single classifier. This model can be exported to other types of cancer and to diseases for which dedicated databases exist.</p

Characterization Of Commercial Magnetorheological Fluids At High Shear Rate: Influence Of The Gap

This paper reports the experimental tests on the behaviour of a commercial MR fluid at high shear rates and the effect of the gap. Three gaps were considered at multiple magnetic fields and shear rates. From an extended set of almost two hundred experimental flow curves, a set of parameters for the apparent viscosity are retrieved by using the Ostwald de Waele model for non-Newtonian fluids. It is possible to simplify the parameter correlation by making the following considerations: the consistency of the model depends only on the magnetic field, the flow index depends on the fluid type and the gap shows an important effect only at null or very low magnetic fields. This lead to a simple and useful model, especially in the design phase of a MR based product. During the off state, with no applied field, it is possible to use a standard viscous model. During the active state, with high magnetic field, a strong non-Newtonian nature becomes prevalent over the viscous one even at very high shear rate; the magnetic field dominates the apparent viscosity change, while the gap does not play any relevant role on the system behaviour. This simple assumption allows the designer to dimension the gap only considering the non-active state, as in standard viscous systems, and taking into account only the magnetic effect in the active state, where the gap does not change the proposed fluid model

Simplified Models for Dark Matter and Missing Energy Searches at the LHC

The study of collision events with missing energy as searches for the dark matter (DM) component of the Universe are an essential part of the extensive program looking for new physics at the LHC. Given the unknown nature of DM, the interpretation of such searches should be made broad and inclusive. This report reviews the usage of simplified models in the interpretation of missing energy searches. We begin with a brief discussion of the utility and limitation of the effective field theory approach to this problem. The bulk of the report is then devoted to several different simplified models and their signatures, including s-channel and t-channel processes. A common feature of simplified models for DM is the presence of additional particles that mediate the interactions between the Standard Model and the particle that makes up DM. We consider these in detail and emphasize the importance of their inclusion as final states in any coherent interpretation. We also review some of the experimental progress in the field, new signatures, and other aspects of the searches themselves. We conclude with comments and recommendations regarding the use of simplified models in Run-II of the LHC.Comment: v2. references added, version submitted to journal. v1. 47 pages, 13 plot

The Dark Matter Halos of Moderate Luminosity X-ray AGN as Determined fromWeak Gravitational Lensing and Host Stellar Masses

Understanding the relationship between galaxies hosting active galactic nuclei (AGN) and the dark matter haloes in which they reside is key to constraining how black hole fuelling is triggered and regulated. Previous efforts have relied on simple halo mass estimates inferred from clustering, weak gravitational lensing, or halo occupation distribution modelling. In practice, these approaches remain uncertain because AGN, no matter how they are identified, potentially live a wide range of halo masses with an occupation function whose general shape and normalization are poorly known. In this work, we show that better constraints can be achieved through a rigorous comparison of the clustering, lensing, and cross-correlation signals of AGN hosts to the fiducial stellar-to-halo mass relation (SHMR) derived for all galaxies, irrespective of nuclear activity. Our technique exploits the fact that the global SHMR can be measured with much higher accuracy than any statistic derived from AGN samples alone. Using 382 moderate luminosity X-ray AGN at z < 1 from the COSMOS field, we report the first measurements of weak gravitational lensing from an X-ray-selected sample. Comparing this signal to predictions from the global SHMR, we find that, contrary to previous results, most X-ray AGN do not live in medium size groups – nearly half reside in relatively low mass haloes with M_(200b) ∼ 10^(12.5) M_⊙. The AGN occupation function is well described by the same form derived for all galaxies but with a lower normalization – the fraction of haloes with AGN in our sample is a few per cent. The number of AGN satellite galaxies scales as a power law with host halo mass with a power-law index α = 1. By highlighting the relatively ‘normal’ way in which moderate luminosity X-ray AGN hosts occupy haloes, our results suggest that the environmental signature of distinct fuelling modes for luminous quasars compared to moderate luminosity X-ray AGN is less obvious than previously claimed

ALMA Observations for CO Emission from Luminous Lyman-break Galaxies at z=6.0293z=6.0293-6.20376.2037

We present our new Atacama Large Millimeter/submillimeter Array (ALMA) observations targeting CO(6-5) emission from three luminous Lyman break galaxies (LBGs) at $z_{\rm spec} = 6.0293$-$6.2037$ found in the Subaru/Hyper Suprime-Cam survey, whose [OIII]$88\mu$m and [CII]$158\mu$m emission have been detected with ALMA. We find a marginal detection of the CO(6-5) line from one of our LBGs, J0235-0532, at the $\simeq 4 \sigma$ significance level and obtain upper limits for the other two LBGs, J1211-0118 and J0217-0208. Our $z=6$ luminous LBGs are consistent with the previously found correlation between the CO luminosity and the infrared luminosity. The unique ensemble of the multiple far-infrared emission lines and underlying continuum fed to a photodissociation region model reveal that J0235-0532 has a relatively high hydrogen nucleus density that is comparable to those of low-$z$ (U)LIRGs, quasars, and Galactic star-forming regions with high $n_{\rm H}$ values, while the other two LBGs have lower $n_{\rm H}$ consistent with local star-forming galaxies. By carefully taking account of various uncertainties, we obtain total gas mass and gas surface density constraints from their CO luminosity measurements. We find that J0235-0532 locates below the Kennicutt-Schmidt (KS) relation, comparable to the previously CO(2-1) detected $z=5.7$ LBG, HZ10. Combined with previous results for dusty starbursts at similar redshifts, the KS relation at $z=5$-$6$ is on average consistent with the local one.Comment: 33 pages, 12 figures, accepted for publication in Ap