198 research outputs found

    Morphosedimentary and phytogeography reconstruction of the middle section of the river Jarama (Madrid, Spain) during the second half of the Holocene.

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    [Abstract] Two sites located on the alluvial plain of the Jarama River, near Madrid, Spain, have been studied using geological, palynological and xylological techniques. Uniquely for this region, numerous wood subfossils of Alnus and Ulmus have been found together with an strobile of Pinus halepensis. This has allowed the stablishment of a coherent radiocarbon chronology, which demonstrates that these sedimentary environments began to develop during the mid Holocene. The dated sediments, which also contains appreciable amounts of pollen, have been deposited upon older palaeosols which has in turn developed directly on the geological substrate. Palynological analyses of these levels have provided valuable insights into the floristic composition of the communities associated with the different biotopes present in the area. As a result of these multiproxy analyses an interpretation of Holocene landscape history and vegetation dynamics is presente

    Diagnosis of multiple sclerosis using optical coherence tomography supported by artificial intelligence

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    Background: Current procedures for diagnosing multiple sclerosis (MS) present a series of limitations, making it critically important to identify new biomarkers. The aim of the study was to identify new biomarkers for the early diagnosis of MS using spectral-domain optical coherence tomography (OCT) and artificial intelligence. Methods: Spectral domain OCT was performed on 79 patients with relapsing-remitting multiple sclerosis (RRMS) (disease duration ≤ 2 years, no history of optic neuritis) and on 69 age-matched healthy controls using the posterior pole protocol that incorporates the anatomic Positioning System. Median retinal thickness values in both eyes and inter-eye difference in healthy controls and patients were evaluated by area under the receiver operating characteristic (AUROC) curve analysis in the foveal, parafoveal and perifoveal areas and in the overall area spanned by the three rings. The structures with the greatest discriminant capacity — retinal thickness and inter-eye difference — were used as inputs to a convolutional neural network to assess the diagnostic capability. Results: Analysis of retinal thickness and inter-eye difference in RRMS patients revealed that greatest alteration occurred in the ganglion cell (GCL), inner plexiform (IPL), and inner retinal (IRL) layers. By using the average thickness of the GCL (AUROC = 0.82) and the inter-eye difference in the IPL (AUROC = 0.71) as inputs to a two-layer convolutional neural network, automatic diagnosis attained accuracy = 0.87, sensitivity = 0.82, and specificity = 0.92. Conclusion: This study adds weight to the argument that neuroretinal structure analysis could be incorporated into the diagnostic criteria for MS

    Engineering DNA-grafted quatsomes as stable nucleic acid-responsive fluorescent nanovesicles

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    The development of artificial vesicles into responsive architectures capable of sensing the biological environment and simultaneously signaling the presence of a specific target molecule is a key challenge in a range of biomedical applications from drug delivery to diagnostic tools. Herein, the rational design of biomimetic DNA-grafted quatsome (QS) nanovesicles capable of translating the binding of a target molecule to amphiphilic DNA probes into an optical output is presented. QSs are synthetic lipid-based nanovesicles able to confine multiple organic dyes at the nanoscale, resulting in ultra-bright soft materials with attractiveness for sensing applications. Dye-loaded QS nanovesicles of different composition and surface charge are grafted with fluorescent amphiphilic nucleic acid-based probes to produce programmable FRET-active nanovesicles that operate as highly sensitive signal transducers. The photophysical properties of the DNA-grafted nanovesicles are characterized and the highly selective, ratiometric detection of clinically relevant microRNAs with sensitivity in the low nanomolar range are demonstrated. The potential applications of responsive QS nanovesicles for biosensing applications but also as functional nanodevices for targeted biomedical applications is envisaged

    Crecimiento Y Partición De Biomasa De Dos Cultivares De Maní (Arachis hypogaea L.) En Distintas Fechas De Siembra En Río Cuarto, Córdoba (Argentina)

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    Crop management practices like the choice of sowing date and of the cultivar modify and affect the environmental conditions of radiation and temperature in which peanut crop grows and develops. The aim of this study was to evaluate the effect that three contrasting sowing dates (SD) had on the growth and partition of biomass of two peanut cultivars of different cycle length; in the peanut-region of Rio Cuarto, Córdoba (Argentina). The experiment was conducted under field circumstances, without restrictions in water, nutrition or sanitary conditions during 2009/10 and 2010/11 growing season in the experimental field of the FAV-UNRC. On a Typical Haplustol soil with a clear light sandy texture. The Granoleico cultivars (runner type with cycle> 155 days) and Utre cultivars (cross runner x Spanish cycle of 130-140 days) were sown in early October, November and December (1st, 2nd and 3rd SD, respectively). During the growth cycle, environmental conditions were recorded, ecophysiological variables of development (phenology, thermal date) and growth (radiation interception, crop growth rate, biomass partitioning factor) of the crop were determined. At harvest, the yield components and market quality were determined, and the conditions to which the crop was exposed were analyzed. The phenological stages of peanut occurred in different environmental regimen due to variations in cycle length of the cultivars, sowing dates and the interaction between these variables. During the early SD, the duration of the cycle was longer, obtaining a greater amount of radiation as compared to the other SD. Both parameters, duration of the cycle and intercepted radiation (IPAR), decreased with late sowing. By delaying the SD, the crop growth rate (CGR) is greater during the initial periods of the crop cycle; an anticipation in the moment of maximum CGR can be seen, changes that occur in response to increased temperature and incident radiation (PAR), reflected in the pattern of biomass production and partition to the different plant organs. The combination of the SD and the length cycle of the cultivars affected the location of the critical period of definition of the yield components and the amount of radiation obtained by the crop. Particularly, the weight of ripe pod and grains was affected, which decreased by delaying the SD, with similar behavior in both cultivars and years of study. As a result, the pod yield and market quality is reduced with the delay of sowing date in both cultivars

    Dye-Loaded Quatsomes Exhibiting FRET as Nanoprobes for Bioimaging

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    Fluorescent organic nanoparticles (FONs) are emerging as an attractive alternative to the well-established fluorescent inorganic nanoparticles or small organic dyes. Their proper design allows one to obtain biocompatible probes with superior brightness and high photostability, although usually affected by low colloidal stability. Herein, we present a type of FONs with outstanding photophysical and physicochemical properties in-line with the stringent requirements for biomedical applications. These FONs are based on quatsome (QS) nanovesicles containing a pair of fluorescent carbocyanine molecules that give rise to Förster resonance energy transfer (FRET). Structural homogeneity, high brightness, photostability, and high FRET efficiency make these FONs a promising class of optical bioprobes. Loaded QSs have been used for in vitro bioimaging, demonstrating the nanovesicle membrane integrity after cell internalization, and the possibility to monitor the intracellular vesicle fate. Taken together, the proposed QSs loaded with a FRET pair constitute a promising platform for bioimaging and theranostics

    Bayesian reasoning with emotional material in patients with schizophrenia.

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    Delusions are one of the most classical symptoms described in schizophrenia. However, despite delusions are often emotionally charged, they have been investigated using tasks involving non-affective material, such as the Beads task. In this study we compared 30 patients with schizophrenia experiencing delusions with 32 matched controls in their pattern of responses to two versions of the Beads task within a Bayesian framework. The two versions of the Beads task consisted of one emotional and one neutral, both with ratios of beads of 60:40 and 80:20, considered, respectively, as the “difficult” and “easy” variants of the task. Results indicate that patients showed a greater deviation from the normative model, especially in the 60:40 ratio, suggesting that more inaccurate probability estimations are more likely to occur under uncertainty conditions. Additionally, both patients and controls showed a greater deviation in the emotional version of the task, providing evidence of a reasoning bias modulated by the content of the stimuli. Finally, a positive correlation between patients’ deviation and delusional symptomatology was found. Impairments in the 60:40 ratio with emotional content was related to the amount of disruption in life caused by delusions. These results contribute to the understanding of how cognitive mechanisms interact with characteristics of the task (i.e., ambiguity and content) in the context of delusional thinking. These findings might be used to inform improved intervention programs in the domain of inferential reasoning.post-print700 K

    Empirical mode decomposition-based filter applied to multifocal electroretinograms in multiple sclerosis diagnosis

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    As multiple sclerosis (MS) usually affects the visual pathway, visual electrophysiological tests can be used to diagnose it. The objective of this paper is to research methods for processing multifocal electroretinogram (mfERG) recordings to improve the capacity to diagnose MS. MfERG recordings from 15 early-stage MS patients without a history of optic neuritis and from 6 control subjects were examined. A normative database was built from the control subject signals. The mfERG recordings were filtered using empirical mode decomposition (EMD). The correlation with the signals in a normative database was used as the classification feature. Using EMD-based filtering and performance correlation, the mean area under the curve (AUC) value was 0.90. The greatest discriminant capacity was obtained in ring 4 and in the inferior nasal quadrant (AUC values of 0.96 and 0.94, respectively). Our results suggest that the combination of filtering mfERG recordings using EMD and calculating the correlation with a normative database would make mfERG waveform analysis applicable to assessment of multiple sclerosis in early-stage patients

    A computer-aided diagnosis of multiple sclerosis based on mfVEP recordings.

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    Introduction: The aim of this study is to develop a computer-aided diagnosis system to identify subjects at differing stages of development of multiple sclerosis (MS) using multifocal visual-evoked potentials (mfVEPs). Using an automatic classifier, diagnosis is performed first on the eyes and then on the subjects. Patients: MfVEP signals were obtained from patients with Radiologically Isolated Syndrome (RIS) (n = 30 eyes), patients with Clinically Isolated Syndrome (CIS) (n = 62 eyes), patients with definite MS (n = 56 eyes) and 22 control subjects (n = 44 eyes). The CIS and MS groups were divided into two subgroups: those with eyes affected by optic neuritis (ON) and those without (non-ON). Methods: For individual eye diagnosis, a feature vector was formed with information about the intensity, latency and singular values of the mfVEP signals. A flat multiclass classifier (FMC) and a hierarchical classifier (HC) were tested and both were implemented using the k-Nearest Neighbour (k-NN) algorithm. The output of the best eye classifier was used to classify the subjects. In the event of divergence, the eye with the best mfVEP recording was selected. Results: In the eye classifier, the HC performed better than the FMC (accuracy = 0.74 and extended Matthew Correlation Coefficient (MCC) = 0.68). In the subject classification, accuracy = 0.95 and MCC = 0.93, confirming that it may be a promising tool for MS diagnosis. Chirped-pulse φOTDR provides distributed strain measurement via a time-delay estimation process. We propose a lower bound for performance, after reducing sampling error and compensating phase-noise. We attempt to reach the limit, attaining unprecedented pε/√Hz sensitivities. Conclusion: In addition to amplitude (axonal loss) and latency (demyelination), it has shown that the singular values of the mfVEP signals provide discriminatory information that may be used to identify subjects with differing degrees of the disease.Secretaría de Estado de Investigación, Desarrollo e InnovaciónInstituto de Salud Carlos II
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