3,019 research outputs found
Role of fibre in broiler diets - Firend or foe?
The fibrous fraction of the feeds encompasses a group of heterogeneous compounds differing in chemical composition and physical properties (Graham and Aman, 1991, Bach Knudsen, 2001). Dietary fiber is the most used term to define the fiber fraction of ingredients and feeds, and includes cell walls, stored non-starch polysaccharides (NSP), and lignin (Bach Knudsen, 2001). Based on their physico-chemical properties, DF can be divided into soluble and insoluble fractions with distinct effects on digestive physiology and animal metabolism. Consequently, the benefits of fiber inclusion in poultry diets will vary depending on factors such as characteristics of the fiber source, type of bird, and digestive health status
Economic crises and market performanceâA machine learning approach
This note analyzes the relationship between economic crises and tourism performance in Spain during the period 1970â2013 using machine learning techniques. Specifically, a regression tree is estimated to confirm that, although the dynamics of Spanish tourism performance is influenced by the general variables established by the literature, the crisis periods disrupt the natural functioning of these dynamics, provoking disturbances that affect the tourism market position of destinations to a greater extent than expected. Conversely, to other econometric techniques, machine learning approach allows us to achieve greater flexibility and enriches the information, estimating the interrelations and thresholds operating in this context
GSK-3ÎČ orchestrates the inhibitory innervation of adult-born dentate granule cells in vivo
Adult hippocampal neurogenesis enhances brain plasticity and contributes to the cognitive reserve during aging. Adult hippocampal neurogenesis is impaired in neurological disorders, yet the molecular mechanisms regulating the maturation and synaptic integration of new neurons have not been fully elucidated. GABA is a master regulator of adult and developmental neurogenesis. Here we engineered a novel retrovirus encoding the fusion protein Gephyrin:GFP to longitudinally study the formation and maturation of inhibitory synapses during adult hippocampal neurogenesis in vivo. Our data reveal the early assembly of inhibitory postsynaptic densities at 1 week of cell age. Glycogen synthase kinase 3 Beta (GSK-3ÎČ) emerges as a key regulator of inhibitory synapse formation and maturation during adult hippocampal neurogenesis. GSK-3ÎČ-overexpressing newborn neurons show an increased number and altered size of Gephyrin+ postsynaptic clusters, enhanced miniature inhibitory postsynaptic currents, shorter and distanced axon initial segments, reduced synaptic output at the CA3 and CA2 hippocampal regions, and impaired pattern separation. Moreover, GSK-3ÎČ overexpression triggers a depletion of Parvalbumin+ interneuron perineuronal nets. These alterations might be relevant in the context of neurological diseases in which the activity of GSK-3ÎČ is dysregulatedPID2020-113007RB-I00, SAF-2017-82185-R, PID2020-112824GB-10
An early myeloma bone disease model in skeletally mature mice as a platform for biomaterial characterization of the extracellular matrix
Multiple myeloma (MM) bone disease is characterized by osteolytic bone tissue destruction resulting in bone pain, fractures, vertebral collapse, and spinal cord compression in patients. Upon initial diagnosis of MM, almost 80% of patients suffer from bone disease. Earlier diagnosis and intervention in MM bone disease would potentially improve treatment outcome and patient survival. New preclinical models are needed for developing novel diagnostic markers of bone structural changes as early as possible in the disease course. Here, we report a proof-of-concept, syngeneic, intrafemoral MOPC315.BM MM murine model in skeletally mature BALB/c mice for detection and characterization of very early changes in the extracellular matrix (ECM) of MM-injected animals. Bioluminescence imaging (BLI) in vivo confirmed myeloma engraftment in 100% of the animals with high osteoclast activity within 21 days after tumor cell inoculation. Early signs of aggressive bone turnover were observed on the outer bone surfaces by high-resolution microcomputed tomography (microCT). Synchrotron phase contrast-enhanced microcomputer tomography (PCE-CT) revealed very local microarchitecture differences highlighting numerous active sites of erosion and new bone at the micrometer scale. Correlative backscattered electron imaging (BSE) and confocal laser scanning microscopy allowed direct comparison of mineralized and nonmineralized matrix changes in the cortical bone. The osteocyte lacunar-canalicular network (OLCN) architecture was disorganized, and irregular-shaped osteocyte lacunae were observed in MM-injected bones after 21 days. Our model provides a potential platform to further evaluate pathological MM bone lesion development at the micro- and ultrastructural levels. These promising results make it possible to combine material science and pharmacological investigations that may improve early detection and treatment of MM bone disease
Methods to study adult hippocampal neurogenesis in humans and across the phylogeny
The hippocampus hosts the continuous addition of new neurons throughout lifeâa phenomenon named adult hippocampal neurogenesis (AHN). Here we revisit the occurrence of AHN in more than 110 mammalian species, including humans, and discuss the further validation of these data by single-cell RNAseq and other alternative techniques. In this regard, our recent studies have addressed the long-standing controversy in the field, namely whether cells positive for AHN markers are present in the adult human dentate gyrus (DG). Here we review how we developed a tightly controlled methodology, based on the use of high-quality brain samples (characterized by short postmortem delays and â€24 h of fixation in freshly prepared 4% paraformaldehyde), to address human AHN. We review that the detection of AHN markers in samples fixed for 24 h required mild antigen retrieval and chemical elimination of autofluorescence. However, these steps were not necessary for samples subjected to shorter fixation periods. Moreover, the detection of labile epitopes (such as Nestin) in the human hippocampus required the use of mild detergents. The application of this strictly controlled methodology allowed reconstruction of the entire AHN process, thus revealing the presence of neural stem cells, proliferative progenitors, neuroblasts, and immature neurons at distinct stages of differentiation in the human DG. The data reviewed here demonstrate that methodology is of utmost importance when studying AHN by means of distinct techniques across the phylogenetic scale. In this regard, we summarize the major findings made by our group that emphasize that overlooking fundamental technical principles might have consequences for any given research fieldAssociation for Frontotemporal Degeneration; Banco de Santander; Center for Networked Biomedical Research on Neurodegenerative Diseases; Consejo Nacional de Ciencia y TecnologĂa (CONACYT), Grant/Award Number: 385084; European Research Council, Grant/Award Number: ERC-CoG2020-101001916; Fundacion Ram on Areces; Secretaria de Educacion, Ciencia TecnologĂa e Innovacion (SECTEI) of the Regional Government of Ciudad de MĂ©xico (CDMX), Grant/Award Number: SECTEI/159/2021; Spanish Ministry of Economy and Competitiveness, Grant/Award Numbers: PID2020-113007RB-I00, RYC-2015-171899, SAF-2017-82185-R; The Alzheimer's Association, Grant/Award Numbers: 2015-NIRG-340709, AARG-17-528125, AARG-17-528125-RAPI
Late Holocene climate variability in the southwestern Mediterranean region: an integrated marine and terrestrial geochemical approach
A combination of marine (Alboran Sea cores, ODP 976 and TTR 300 G) and terrestrial (Zoñar Lake, Andalucia, Spain) geochemical proxies provides a high-resolution reconstruction of climate variability and human influence in the southwestern Mediterranean region for the last 4000 years at inter-centennial resolution. Proxies respond to changes in precipitation rather than temperature alone. Our combined terrestrial and marine archive documents a succession of dry and wet periods coherent with the North Atlantic climate signal. A dry period occurred prior to 2.7 cal ka BP â synchronously to the global aridity crisis of the third-millennium BC â and during the Medieval Climate Anomaly (1.4â0.7 cal ka BP). Wetter conditions prevailed from 2.7 to 1.4 cal ka BP. Hydrological signatures during the Little Ice Age are highly variable but consistent with more humidity than the Medieval Climate Anomaly. Additionally, Pb anomalies in sediments at the end of the Bronze Age suggest anthropogenic pollution earlier than the Roman Empire development in the Iberian Peninsula. The Late Holocene climate evolution of the in the study area confirms the see-saw pattern between the eastern and western Mediterranean regions and the higher influence of the North Atlantic dynamics in the western Mediterranean
Interactions between 2,4-bis-pteridine-1,5-benzodiazepine and group 12 dihalides: synthesis, spectral and XRD structural studies and theoretical calculations
2,4-Bis(1,3,7-trimethyl-pteridine-2,4(1H,3H)-dione-6-yl)-2,3-dihydro-2-methyl-1H-1,5-benzodiazepine (DLMBZD) has been prepared and its molecular and crystal structures have been determined from spectral and XRD data. The benzodiazepine ligand was reacted with zinc(II), cadmium(II) and mercury(II) chloride, bromide and iodide to give complexes with general formula [M(DLMBZD)X2]. The complexes have been synthesized and characterized by IR, NMR and elemental analysis. The structure of seven complexes has been obtained by single crystal X-ray diffraction. In all the cases, the metal is (2 + 2 + 1)-five-coordinated by two halide ligands, two nitrogen atoms from pyrazine and diazepine rings and a carbonyl oxygen from a pteridine ring. The coordinated-metal environment is a square-based pyramid, with increasing trigonality from Hg(II) to Zn(II) complexes. To coordinate the metals, the ligand folds itself, establishing four intramolecular ÏâÏ interactions with the pyrimidine and pyrazine rings. A topological analysis of the electron density using the Quantum Theory of Atoms in Molecules and the complexes stability has been performed.Supported by the University of JaĂ©n (Plan de Apoyo a la InvestigaciĂłn, al Desarrollo TecnolĂłgico y a la InnovaciĂłn), Junta de AndalucĂa (PAIDI groups FQM195, FQM273 and FQM337) and the State Secretariat for Research, Development and Innovation of Spanish Ministry of Economy and Competitivity (Project âRed de Excelencia MetalBioâ, CTQ2015-71211-REDT)
Charged-current inclusive neutrino cross sections in the SuperScaling model
SuperScaling model (SuSA) predictions to neutrino-induced charged-current Ï+ production in the Î-resonance region are explored under MiniBooNE experimental conditions. The SuSA charged-current Ï+ results are in good agreement with data on neutrino flux-averaged double-differential cross sections. The SuSA model for quasielastic scattering and its extension to the pion production region are used for predictions of charged-current inclusive neutrino- nucleus cross sections. The contribution of two-particle-two-hole vector meson-exchange current excitations is also considered within a fully relativistic model. Results are compared with the T2K experimental data for inclusive scattering.España, DGI y FundaciĂłn FEDER FIS2011-28738-C02-01, FPA2013-41267Junta de AndalucĂa CSD2007-0004
1,3,7-Trimethyl-2,4-dioxo-1,2,3,4-tetraÂhydroÂpteridine-6-carboxylic acid hemihydrate
In the title compound, C10H10N4O4·0.5H2O, the two rings of the pteridine system are nearly coplanar [dihedral angle = 4.25â
(9)°]. The atoms of the carboxyl group are also coplanar with the pteridine unit [r.m.s. deviation from the mean plane of the pteridine skeleton = 0.092â
(2)â
Ă
]. In the crystal, the presence of the water molecule of crystallization (O atom site symmetry 2) leads to a hydrogen-bonding pattern different from the one shown by many carboxylic acid compounds (dimers formed through OâHâŻO hydrogen bonds between neighbouring carboxyl groups): in the present structure, the water molÂecule, which lies on a binary axis, acts as a bridge between two molÂecules, forming a hydrogen-bonded dimer. In addition to the hydrogen bonds, there are ÏâÏ ring stacking interÂactions involving the pyrimidine and pyrazine rings [centroidâcentroid distance = 3.689â
(1)Ă
], and two different pyrazine rings [centroidâcentroid distance = 3.470â
(1)Ă
]. Finally, there is a CâOâŻÏ contact involving a carboxylÂate CâO and the pyrimidine ring with a short OâŻCg distance of 2.738â
(2)â
Ă
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