The amygdala is composed of multiple nuclei with unique functions and connections in the limbic system and to the rest of the brain. However, standard in vivo neuroimaging tools to automatically ...delineate the amygdala into its multiple nuclei are still rare. By scanning postmortem specimens at high resolution (100–150µm) at 7T field strength (n = 10), we were able to visualize and label nine amygdala nuclei (anterior amygdaloid, cortico-amygdaloid transition area; basal, lateral, accessory basal, central, cortical medial, paralaminar nuclei). We created an atlas from these labels using a recently developed atlas building algorithm based on Bayesian inference. This atlas, which will be released as part of FreeSurfer, can be used to automatically segment nine amygdala nuclei from a standard resolution structural MR image. We applied this atlas to two publicly available datasets (ADNI and ABIDE) with standard resolution T1 data, used individual volumetric data of the amygdala nuclei as the measure and found that our atlas i) discriminates between Alzheimer's disease participants and age-matched control participants with 84% accuracy (AUC=0.915), and ii) discriminates between individuals with autism and age-, sex- and IQ-matched neurotypically developed control participants with 59.5% accuracy (AUC=0.59). For both datasets, the new ex vivo atlas significantly outperformed (all p < .05) estimations of the whole amygdala derived from the segmentation in FreeSurfer 5.1 (ADNI: 75%, ABIDE: 54% accuracy), as well as classification based on whole amygdala volume (using the sum of all amygdala nuclei volumes; ADNI: 81%, ABIDE: 55% accuracy). This new atlas and the segmentation tools that utilize it will provide neuroimaging researchers with the ability to explore the function and connectivity of the human amygdala nuclei with unprecedented detail in healthy adults as well as those with neurodevelopmental and neurodegenerative disorders.
•We visualized 9 nuclei boundaries (anterior amygdaloid area, cortico-amygdaloid transition area; basal, lateral, accessory basal, central, cortical medial, paralaminar nuclei) using ultra-high-resolution ex vivo imaging.•Nuclei were consistent across cases and raters.•We built a segmentation atlas of the amygdala nuclei, which will be distributed with FreeSurfer.•Atlas was applied to 2 datasets and showed higher discriminability of Alzheimer's & autism than previously possible.•The atlas will provide neuroimaging researchers with the ability to test nucleus function with greater spatial specificity.
We study two galaxies samples selected in near-ultraviolet (NUV) and in far-infrared (FIR) for which the spectral energy distributions (SEDs) from the far-UV (FUV) to the FIR are available. We ...compared the observed SEDs to modelled SEDs with several star formation histories (SFHs; decaying star formation rate plus burst) and dust attenuation laws (power law + 2175 Å bump). The Bayesian method allows one to estimate statistically the best parameters by comparing each observed SED to the full set of 82 800 models. We reach the conclusion that the UV dust attenuation cannot be estimated correctly from SED analysis if the FIR information is not used. The dispersion is larger than with the FIR data. The distribution is also not symmetrically distributed about zero: there is an overestimation for UV-selected galaxies and an underestimation for FIR-selected galaxies. The output from the analysis process suggests that UV-selected galaxies have attenuation laws in average similar to the Large Magellanic Cloud extinction law while FIR-selected galaxies attenuation laws resemble more the Milky Way extinction law. The dispersion about the average relation in the log (Fdust/FFUV) versus FUV-NUV diagram (once the main relation with FUV - NUV accounted for) is explained by two other parameters: the slope of the attenuation law and the instantaneous birthrate parameters b0 for UV-selected galaxies and the same ones plus the strength of the bump for the FIR-selected galaxies. We propose a recipe to estimate the UV dust attenuation for UV galaxies only (that should only be used whenever the FIR information is not available because the resulting AFUV is poorly defined with an uncertainty of about 0.32): AFUV= 1.4168 (FUV - NUV)2+ 0.3298 (NUV - I)2+ 2.1207 (FUV - NUV) + 2.7465 (NUV - I) + 5.8408.
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•Arenesulfonic SBA-15 successfully used in the synthesis of EMF from fructose.•High catalytic activity ascribed to adequate textural properties and acid sites strength.•DMSO used as ...co-solvent significantly enhances the production of EMF.•Reaction conditions (T, catalyst loading and DMSO concentration) optimized via experimental design.
The use of sulfonic acid-functionalized heterogeneous catalysts in conjunction with the use of dimethyl sulfoxide (DMSO) as co-solvent in the catalytic transformation of fructose in ethanol to produce 5-ethoxymethyl furfural (EMF) is shown as an interesting alternative route for the production of this advanced biofuel. Arenesulfonic acid-modified SBA-15 mesostructured silica (Ar-SO3H-SBA-15) has been the most active catalyst, ascribing its higher catalytic performance to the combination of excellent textural properties, acid sites surface concentration and acid strength. Noticeably, DMSO promotes the formation of EMF and HMF, reducing the extent of side reactions. Reaction conditions (temperature, catalyst loading and DMSO concentration) where optimized for Ar-SO3H-SBA-15 via response surface methodology leading to a maximum EMF yield of 63.4% at 116 °C, 13.5mol% catalyst loading based on starting fructose and 8.3vol.% of DMSO in ethanol after 4h of reaction. Catalyst was reused up to 4 consecutive times, without regeneration treatment, showing a slight gradual decay in activity attributed to the formation of organic deposits on the catalyst’s surface.
ABSTRACT
Using new Very Large Telescope (VLT)/XShooter spectral observations we analyse the physical properties of five z ∼ 0.3–0.4 confirmed Lyman continuum (LyC) leakers. Strong resonant Mg ...ii λλ2796, 2803 Å emission lines (I(λλ2796, 2803)/I(Hβ) ≃ 10–38 per cent) and non-resonant Fe ii* λλ2612, 2626 Å emission lines are observed in spectra of five and three galaxies, respectively. We find high electron densities Ne ∼ 400 cm−3, significantly higher than in typical low-z, but comparable to those measured in z ∼ 2–3 star-forming galaxies (SFGs). The galaxies have a mean value of log N/O = –1.16, close to the maximum values found for SFGs in the metallicity range of 12 + log O/H ≃ 7.7–8.1. All 11 low-z LyC emitting galaxies found by Izotov et al., including the ones considered in this study, are characterized by high equivalent width (EW) (Hβ) ∼ 200–400 Å, high ionization parameter (log(U) = –2.5 to –1.7), high average ionizing photon production efficiency ξ = 1025.54 Hz erg−1, and hard ionizing radiation. On the Baldwin–Phillips–Terlevich (BPT) diagram we find the same offset of our leakers from low-z main-sequence SFGs as that for local analogues of Lyman-break galaxies (LBGs) and extreme SFGs at z ∼ 2–3. We confirm the effectiveness of the He i emission lines diagnostics proposed by Izotov et al. in searching for LyC leaker candidates and find that their intensity ratios correspond to those in a median with low neutral hydrogen column density N(H i) = 1017–5 × 1017 cm−2 that permit leakage of LyC radiation, likely due to their density-bounded H ii regions.
The neonicotinoid insecticide imidacloprid (IMI) affects the insect central nervous system and is successfully applied to control pests for a variety of agricultural crops. In the current study, ...acute toxicity and genotoxicity of the IMI-containing commercial formulation insecticide Glacoxan Imida (35 percent IMI) was evaluated on Hypsiboas pulchellus (Anura: Hylidae) tadpoles exposed under laboratory conditions. A lethal effect was evaluated as the end point for lethality, whereas micronucleus (MN) frequency and DNA single-strand breaks evaluated by the single cell gel electrophoresis (SCGE) assay were employed as end points for genotoxicity. Sublethal end points were assayed within the 12.5–37.5mg/L IMI concentration range. Experiments were performed on tadpoles at stage 36 (range, 35–37) according to the classification proposed by Gosner. Lethality studies revealed an LC50 96h value of 52.622mg/L IMI. Increased frequency of MNs was only observed when 25.0mg/L was assayed for 96h, whereas no other nuclear abnormalities were induced. Increase of the genetic damage index was observed at 48h of treatment within the 12.5–37.5mg/L concentration range, whereas an increased frequency of DNA damage was observed only in tadpoles treated with 37.5mg/L IMI for 96h. This study represents the first evidence of the acute lethal and genotoxic effects exerted by IMI on tadpoles of an amphibian species native to Argentina under laboratory conditions.
•IMI lethal and genotoxic properties were evaluated on Hypsiboas pulchellus.•Determination of LC50 96h was employed as lethal end point.•IMI induced micronuclei and DNA single-strand breaks in circulating blood cells.•First evidence of genotoxicity exerted by IMI on an Argentinean amphibian species.
Volume deficits of the hippocampus in schizophrenia have been consistently reported. However, the hippocampus is anatomically heterogeneous; it remains unclear whether certain portions of the ...hippocampus are affected more than others in schizophrenia. In this study, we aimed to determine whether volume deficits in schizophrenia are confined to specific subfields of the hippocampus and to measure the subfield volume trajectories over the course of the illness. Magnetic resonance imaging scans were obtained from Data set 1: 155 patients with schizophrenia (mean duration of illness of 7 years) and 79 healthy controls, and Data set 2: an independent cohort of 46 schizophrenia patients (mean duration of illness of 18 years) and 46 healthy controls. In addition, follow-up scans were collected for a subset of Data set 1. A novel, automated method based on an atlas constructed from ultra-high resolution, post-mortem hippocampal tissue was used to label seven hippocampal subfields. Significant cross-sectional volume deficits in the CA1, but not of the other subfields, were found in the schizophrenia patients of Data set 1. However, diffuse cross-sectional volume deficits across all subfields were found in the more chronic and ill schizophrenia patients of Data set 2. Consistent with this pattern, the longitudinal analysis of Data set 1 revealed progressive illness-related volume loss (~2-6% per year) that extended beyond CA1 to all of the other subfields. This decline in volume correlated with symptomatic worsening. Overall, these findings provide converging evidence for early atrophy of CA1 in schizophrenia, with extension to other hippocampal subfields and accompanying clinical sequelae over time.
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