370 research outputs found
Sea Level Changes Affect Seismicity Rates in a Hydrothermal System Near Istanbul
Small stress changes such as those from sea level fluctuations can be large enough to trigger earthquakes. If small and large earthquakes initiate similarly, high-resolution catalogs with low detection thresholds are best suited to illuminate such processes. Below the Sea of Marmara section of the North Anatolian Fault, a segment of urn:x-wiley:00948276:media:grl65397:grl65397-math-0001150 km is late in its seismic cycle. We generated high-resolution seismicity catalogs for a hydrothermal region in the eastern Sea of Marmara employing AI-based and template matching techniques to investigate the link between sea level fluctuations and seismicity over 6 months. All high resolution catalogs show that local seismicity rates are larger during time periods shortly after local minima of sea level, when it is already rising. Local strainmeters indicate that seismicity is promoted when the ratio of differential to areal strain is the largest. The strain changes from sea level variations, on the order of 30â300 nstrain, are sufficient to promote seismicity
Experimental Investigation on Thermal Diffusivity of PM Steels
The scanty literature data on thermal diffusivity of P/M steels seems contradictory, if the cooling speed on quenching is the evaluation parameter. Due to the basic importance of diffusivity on the response of P/M steels to heat-treating, an experimental survey has been carried out, to collect data on various P/M steels, based on prealloyed, or diffusion-bonded, or admixed powders. The study has also covered the influence of processing parameters, such as compaction pressure and sintering temperature. The flash method has been used to measure the thermal diffusivity of P/M steels. This method directly measures the thermal diffusivity of a sample in slab shape. A plane-parallel sample is inserted in the test apparatus and then a short light pulse, produced by a laser or a flash lamp, heats the front surface of the sample. The heat diffuses through the sample, leading to a temperature rise on the sample rear surface. An infrared detector measures this temperature rise, versus time, and thermal diffusivity is derived from the least square regression on the whole temperature trend, using the analytical solution of heat conduction. The results show that thermal diffusivity increases as density increases. This achievement can be justified by a simple theoretical analysis of the thermal conductivity on thermal diffusivity. The collected data also enable us to ascertain the influence of sintered material composition and carbon content on thermal diffusivity. The results should contribute to clarify some uncertainties and perplexities on the behavior of properly elaborated P/M steels, to be hardened by heat treatment, conventional â such as oil quenching â or innovative, such as sinter -hardening
An extended assessment of bowel habits in a general population.
Bowel habits are difficult to study, and most data on defecatory behaviour in the general population have been obtained on the basis of recalled interview. The objective assessment of this physiological function and its pathological aspects continues to pose a difficult challenge. The aim of this prospective study was to objectively assess the bowel habits and related aspects in a large sample drawn from the general population
Direct Evidence of a SlowâSlip Transient Modulating the Spatiotemporal and FrequencyâMagnitude Earthquake Distribution: Insights From the Armutlu Peninsula, Northwestern Turkey
Earthquakes and slowâslip events interact, however, detailed studies investigating their interplay are still limited. We generate the highest resolution microseismicity catalog to date for the northern Armutlu Peninsula in a âŒ1âyear period to perform a detailed seismicity distribution analysis and correlate the results with a local, geodetically observed slowâslip transient within the same period. Seismicity shows a transition of clusterâtype behavior from swarmâlike to burstâlike, accompanied by an increasing relative proportion of clustered (nonâPoissonian) relative to background (Poissonian) seismicity and gradually decreasing bâvalue as the geodetically observed slowâslip transient ends. The observed slowâslip transient decay correlates with gradually increasing effectiveâstressâdrop values. The observed correlation between the bâvalue and geodetic transient highlights the influence of aseismic deformation on seismic deformation and the impact of slowâslip transients on local seismic hazard
PN_SCD1, VESICLE TRAFFICKING REGULATOR IS DEMETHYLATED AND OVEREXPRESSED IN FLORETS OF APOMICTIC PASPALUM NOTATUM GENOTYPES
Apomixis (asexual reproduction through seeds) is considered a deviation of the sexual
reproductive pathway leading to the formation of clonal progenies genetically identical to the
mother plant. It has been suggested that apomixis might be a consequence of epigenetic alterations,
such as interspecific hybridization and polyploidization, resulting in a wide deregulation of
reproductive development. Studies on epigenetic are transforming our actual idea of the structural
variation and diversity that prevails at key steps of plant female gametogenesis, with deep
implications for understanding the evolutionary trends that model innovation in reproductive
development and adaptation. Recent results have provided evidences indicating that epigenetic
mechanisms are crucial to control events that distinguish sexual from apomictic development.
Therefore, the epigenetic regulation of apomixis is an attractive theory as it potentially accounts for
the facultative nature of apomixis as well as the ability of apomictic to revert back to sexuality. In
this work we used the Methylation-Sensitive Amplification Polymorphism (MSAP) technique to
characterize floral genome cytosine methylation patterns occurring in sexual and aposporous
Paspalum notatum genotypes, in order to identify epigenetically-controlled genes putatively
involved in apomixis development. A partial and rather divergent methylation reprogramming was
detected in apomictic genotypes. From twelve polymorphic MSAP-derived sequences, one
(PN_6.6, renamed PN_SCD1) was selected due to its relevant annotation and differential
representation in 454 floral transcriptome libraries of sexual and apomictic P. notatum. PN_6.6
encodes the DENN domain/WD repeat-containing protein SCD1, which interacts with RAB
GTPases- and/or MAPKs to promote specialized cell division, functions in clathrin-mediated
membrane transport and was defined as potential substrate receptor of CUL4 E3 ubiquitin ligases.
Quantitative RT-PCR and comparative RNAseq analyses of laser microdissected nucellar cells
confirmed PN_SCD1 upregulation in florets of apomictic plants and revealed that overexpression
takes place just before the onset of apospory initials. Moreover, we found that several SCD1
molecular partners are upregulated in florets of P. notatum apomictic plants. Our results revealed a
specific vesicle trafficking molecular pathway epigenetically modulated during apomixis. Results
will be presented and critically discussed
Combining preclinical tools and models to unravel tumor complexity: Jump into the next dimension
Tumors are complex and heterogeneous diseases characterized by an intricate milieu and dynamically in connection with surrounding and distant tissues. In the last decades, great efforts have been made to develop novel preclinical models able to recapitulate the original features of tumors. However, the development of an in vitro functional and realistic tumor organ is still utopic and represents one of the major challenges to reproduce the architecture of the tumor ecosystem. A strategy to decrypt the whole picture and predict its behavior could be started from the validation of simplified biomimetic systems and then proceed with their integration. Variables such as the cellular and acellular composition of tumor microenvironment (TME) and its spatio-temporal distribution have to be considered in order to respect the dynamic evolution of the oncologic disease. In this perspective, we aim to explore the currently available strategies to improve and integrate in vitro and in vivo models, such as three-dimensional (3D) cultures, organoids, and zebrafish, in order to better understand the disease biology and improve the therapeutic approaches
A Stochastic Multi-scale Approach for Numerical Modeling of Complex Materials - Application to Uniaxial Cyclic Response of Concrete
In complex materials, numerous intertwined phenomena underlie the overall
response at macroscale. These phenomena can pertain to different engineering
fields (mechanical , chemical, electrical), occur at different scales, can
appear as uncertain, and are nonlinear. Interacting with complex materials thus
calls for developing nonlinear computational approaches where multi-scale
techniques that grasp key phenomena at the relevant scale need to be mingled
with stochastic methods accounting for uncertainties. In this chapter, we
develop such a computational approach for modeling the mechanical response of a
representative volume of concrete in uniaxial cyclic loading. A mesoscale is
defined such that it represents an equivalent heterogeneous medium: nonlinear
local response is modeled in the framework of Thermodynamics with Internal
Variables; spatial variability of the local response is represented by
correlated random vector fields generated with the Spectral Representation
Method. Macroscale response is recovered through standard ho-mogenization
procedure from Micromechanics and shows salient features of the uniaxial cyclic
response of concrete that are not explicitly modeled at mesoscale.Comment: Computational Methods for Solids and Fluids, 41, Springer
International Publishing, pp.123-160, 2016, Computational Methods in Applied
Sciences, 978-3-319-27994-
46 Measurements of Reactive Oxygen Species production induced by Gold Nanoparticles in Radiotherapy protocols
Cancer incidence in pet dogs: findings of the Animal Tumor Registry of Genoa, Italy.
Background: The occurrence of spontaneous tumors in pet animals has been estimated in a few European and North American veterinary cancer registries with dissimilar methodologies and variable reference populations. Objectives: The Animal Tumor Registry (ATR) of Genoa, Italy, was established in 1985 with the aim of estimating the occurrence of spontaneous tumors in dogs. Methods: Six thousand seven hundred and forty-three tumor biopsy specimens were received from local veterinarians in the Municipality of Genoa between 1985 and 2002. Three thousand and three hundred and three (48.9%) biopsy specimen samples were diagnosed as cancer and were coded according to the International Statistical Classification of Diseases (ICD-9). Results: Mammary cancer was the most frequently diagnosed cancer in female dogs, accounting for 70% of all cancer cases. Incidence of all cancers was 99.3 per 100,000 dog-years (95% CI: 93.6â105.1) in male dogs and 272.1 (95% CI: 260.7â283.6) in female dogs. The highest incidence rates were detected for mammary cancer (IR = 191.8, 95% CI: 182.2â201.4) and for non-Hodgkin's lymphoma (IR = 22.9, 95% CI: 19.7â26.5) in bitches and for non-Hodgkin's lymphoma (IR = 19.9, 95% CI: 17.4â22.7) and skin cancer (IR = 19.1, 95% CI: 16.6â21.8) in male dogs. All cancer IR increased with age ranging between 23.7 (95% CI: 18.4â30.1) and 763.2 (95% CI: 700.4â830.1) in bitches and between 16.5 (95% CI: 12.8â21.1) and 237.6 (95% CI: 209.1â269.0) in male dogs aged â€3 years and >9â11 years. Conclusion: This study summarizes the work done by the ATR of Genoa, Italy, between 1985 and 2002. All cancer incidence was 3 times higher in female than in male dogs, a difference explained by the high rate of mammary cancer observed in bitches. Because a biopsy specimen was required to make a cancer diagnosis, cancer rates for internal organs cancers, such as respiratory and digestive tract cancers may have been underestimated in the study population
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