Universal Magnetic Properties of sp3^3-type Defects in Covalently Functionalized Graphene

Using density-functional calculations, we study the effect of sp$^3$-type defects created by different covalent functionalizations on the electronic and magnetic properties of graphene. We find that the induced magnetic properties are {\it universal}, in the sense that they are largely independent on the particular adsorbates considered. When a weakly-polar single covalent bond is established with the layer, a local spin-moment of 1.0 $\mu_B$ always appears in graphene. This effect is similar to that of H adsorption, which saturates one $p_z$ orbital in the carbon layer. The magnetic couplings between the adsorbates show a strong dependence on the graphene sublattice of chemisorption. Molecules adsorbed at the same sublattice couple ferromagnetically, with an exchange interaction that decays very slowly with distance, while no magnetism is found for adsorbates at opposite sublattices. Similar magnetic properties are obtained if several $p_z$ orbitals are saturated simultaneously by the adsorption of a large molecule. These results might open new routes to engineer the magnetic properties of graphene derivatives by chemical means

Glucose metabolism and oscillatory behavior of pancreatic islets

A variety of oscillations are observed in pancreatic islets.We establish a model, incorporating two oscillatory systems of different time scales: One is the well-known bursting model in pancreatic beta-cells and the other is the glucose-insulin feedback model which considers direct and indirect feedback of secreted insulin. These two are coupled to interact with each other in the combined model, and two basic assumptions are made on the basis of biological observations: The conductance g_{K(ATP)} for the ATP-dependent potassium current is a decreasing function of the glucose concentration whereas the insulin secretion rate is given by a function of the intracellular calcium concentration. Obtained via extensive numerical simulations are complex oscillations including clusters of bursts, slow and fast calcium oscillations, and so on. We also consider how the intracellular glucose concentration depends upon the extracellular glucose concentration, and examine the inhibitory effects of insulin.Comment: 11 pages, 16 figure

Obtaining and evaluation of enzymatic extract from Aspergillus spp. by saccharification of sour cassava starch liqued

The saccharification enzymes are more expensive than liquefaction enzymes for that reason are sought strategies that allow the supply of these enzymes at low cost. The objectives of this study were to evolve saccharolytic enzymatic extracts from native strains, to select an extract and to determine the best variables for the production of glucose syrups from liquefied bitter cassava starch.Thirteen mushrooms isolated from sour cassava (Manihot sp). were evaluated for their saccharolytic activity, hydrolysis of maltose, glucose production and biomass formation in submerged fermentation. Aspergillus A1 was selected because it had the highest volumetric activity (0.09UI.L-1). During solid-state fermentation, the presence of proteins was corroborated by electrophoresis SDS-PAGE. Through various experiments, the best experimental condition were pH 4.0, agitation 0r.p.m and temperature 55.0°C; the effect of cofactors Cu2+, K+, Mg2+ and Na+ was evaluated, Mg2+ increases the activity in 1.32UImg-1 (32.4%). The thermal stability at 55.0°C is 120 minutes. Finally, the saccharolytic capacity of the enzymatic extract was confirmed using liquefied cassava starch.Comercialmente as enzimas de sacarificação são mais custosas do que as de liquefação, por esta razão procuram-se estratégias que permitam fornecer este tipo de enzimas a baixo custo. Os objetivos deste estúdio foram avaliar extratos enzimáticos sacarolīticos de cepas nativas, selecionar um extrato e determinar as melhores variáveis para a produção de xaropes de glicose. Para isto, de treze fungos filamentosos isolados de mandioca amarga Manihot sp., foram avaliadas a atividade sacarolítica, a hidrólise de maltose, a produção de glicose e a formação de biomassa em condições de fermentação submersa. O isolamento Aspergillus A1 foi selecionado por apresentar a maior atividade volumétrica (0,091UI.L-1). Durante a fermentação em superfície a presença de proteínas foi confirmada pelo método de eletroforese de SDS-PAGE junto com uma banda de maior intensidade com peso molecular entre os 60 e 70kDa. Para os preparados enzimáticos de Aspergillus A1 determinou-se que as melhores condições experimentais de sacarificação usando maltose como substrato foram pH 4,0, temperatura de 55,0°C, sem agitação. Igualmente na avaliação do efeito dos cofatores Cu2+, K+, Mg2+ e Na+ em concentrações de 1 mM, observou-se que todos incrementam a atividade enzimática principalmente o Mg2+ em 1,32UI.mg-1 (32,4%) em relação ao controle. A estabilidade térmica da proteína de 55,0°C é de 120 minutos. A capacidade sacarolítica do extrato enzimático foi confirmada usando substrato hidrolisado de mandioca amarga.Comercialmente las enzimas de sacarificación son más costosas que las de licuefacción, por tal razón se buscan estrategias que permitan el suministro de estas enzimas a bajo costo. Los objetivos de este estudio fueron evaluar extractos enzimáticos sacarolíticos a partir de cepas nativas, seleccionar un extracto y determinar las mejores variables para la producción de jarabes de glucosa. Para ello, en trece hongos filamentosos aislados de yuca amarga Manihot sp. fueron evaluadas la actividad sacarolítica, la hidrólisis de maltosa, la producción de glucosa y la formación de biomasa bajo condiciones de fermentación sumergida. El aislamiento identificado como Aspergillus A1 fue seleccionado por presentar la más alta actividad volumétrica (0,09UI.L-1). Durante la fermentación en estado sólido se corroboró la presencia de proteínas mediante el método de electroforesis SDS-PAGE y se evidenció una banda de mayor intensidad con peso molecular entre 60 y 70 kDa. Para el extracto enzimático de Aspergillus A1 se determinó que las mejores condiciones experimentales de sacarificación, con el uso de maltosa como sustrato, fueron pH 4,0, temperatura 55,0 °C, y sin agitación. Igualmente en la evaluación del efecto de los cofactores Cu2+, K+, Mg2+ y Na+ en concentraciones de 1 mM, se observó que todos incrementan la actividad enzimática especialmente el Mg2+ , el cual la aumenta en 1,32 UI.mg-1 (32,4%). La estabilidad térmica de la proteína a 55,0°C fue de 120 minutos. La capacidad sacarolítica del extracto enzimático fue confirmada usando como sustrato almidón de yuca amarga licuado

Revista de Vertebrados de la Estación Biológica de Doñana

Datos sobre la fauna de anfibios del Bajo GuadalquivirDiet of the Black Vulture (Aegypius monachus) in the Iberian PeninsulaBiología de reproducción de una pareja de Hieraetus fasciatus en España central.Sobre la migraclon de la focha común (Fulica atra) en el Mediterráneo Occidental en base a la información de la Estación Biológica de laTour du Valat (Camargue, Francia)Problemática y medidas de conservación de la Foca fraile (Monachus monachus, Hermann 1779) en el Sahara OccidentaNuevas citas de sifonápteros parásitos de mamíferos en España.Contribución al estudio de Lacerta monticola en la Sierra de Gredos (Avila. España)A melanistic Spanish smooth snake (Coranella a. austriaca)Nueva localidad para Vipera b. berus en el. Norte de EspañaSegunda cita en España de Porphyrula alleni (Thomson, 1842)Peer reviewe

alpha-particle production in the scattering of 6He by 208Pb at energies around the Coulomb barrier

New experimental data from the scattering of 6He+208Pb at energies around and below the Coulomb barrier are presented. The yield of breakup products coming from projectile fragmentation is dominated by a strong group of $\alpha$ particles. The energy and angular distributions of this group have been analyzed and compared with theoretical calculations. This analysis indicates that the $\alpha$ particles emitted at backward angles in this reaction are mainly due to two-neutron transfer to weakly bound states of the final nucleus.Comment: 20 pages, 5 figures. Nuclear Physics A792 (2007) 2-1

Nonlinear dispersive waves in repulsive lattices

[EN] The propagation of nonlinear waves in a lattice of repelling particles is studied theoretically and experimentally. A simple experimental setup is proposed, consisting of an array of coupled magnetic dipoles. By driving harmonically the lattice at one boundary, we excite propagating waves and demonstrate different regimes of mode conversion into higher harmonics, strongly influenced by dispersion and discreteness. The phenomenon of acoustic dilatation of the chain is also predicted and discussed. The results are compared with the theoretical predictions of $\alpha$-FPU equation, describing a chain of masses connected by nonlinear quadratic springs and numerical simulations. The results can be extrapolated to other systems described by this equation.The work was supported by Spanish Ministry of Economy and Innovation (MINECO) and European Union FEDER through Project No. FIS2015- 65998-C2-2 and by Project No. AICO/2016/060 by Conselleria de Educacion, Investigacion, Cultura y Deporte de la Generalitat Valenciana. L.J.S.-C. gratefully acknowledge the support of PAID-01-14 at Universitat Politscnica de Valsncia. A. M. gratefully acknowledge to Generalitat Valenciana (Santiago Grisolia program).Mehrem, A.; Jimenez, N.; Salmerón-Contreras, LJ.; García-Andrés, FX.; García-Raffi, LM.; Picó Vila, R.; Sánchez Morcillo, VJ. (2017). Nonlinear dispersive waves in repulsive lattices. Physical Review E. 96(1). https://doi.org/10.1103/PhysRevE.96.012208S00220096

Tunable dual-wavelength operation of an all- fiber thulium-doped fiber laser based on tunable fiber Bragg gratings

Tunable dual-wavelength emission of a Tm-doped fiber laser based on two fiber Bragg gratings(FBGs) is experimentally demonstrated. By using two FBGs with central wavelengths at 2069.30 and 2069.44 nm, stable dual-wavelength laser generation in the 2 μm wavelength region is achieved by adjusting the differential loss of the two wavelengths in the laser cavity. Strain applied on the FBG allows independent tuning of the simultaneously generated wavelengths with separation between the laser lines in a range from 0.54 to 9 nm. The laser has output power fluctuations less than 0.093% for an output power of 77.3 mW

Repeatedly Northwards and Upwards: Southern African Grasslands Fuel the Colonization of the African Sky Islands in Helichrysum (Compositae)

The Afromontane and Afroalpine areas constitute some of the main biodiversity hotspots of Africa. They are particularly rich in plant endemics, but the biogeographic origins and evolutionary processes leading to this outstanding diversity are poorly understood. We performed phylogenomic and biogeographic analyses of one of the most species-rich plant genera in these mountains, Helichrysum (Compositae-Gnaphalieae). Most previous studies have focused on Afroalpine elements of Eurasian origin, and the southern African origin of Helichrysum provides an interesting counterexample. We obtained a comprehensive nuclear dataset from 304 species (≈50% of the genus) using target-enrichment with the Compositae1061 probe set. Summary-coalescent and concatenation approaches combined with paralog recovery yielded congruent, well-resolved phylogenies. Ancestral range estimations revealed that Helichrysum originated in arid southern Africa, whereas the southern African grasslands were the source of most lineages that dispersed within and outside Africa. Colonization of the tropical Afromontane and Afroalpine areas occurred repeatedly throughout the Miocene-Pliocene. This timing coincides with mountain uplift and the onset of glacial cycles, which together may have facilitated both speciation and intermountain gene flow, contributing to the evolution of the Afroalpine flora.This work received financial support from the Spanish Ministry of Science, Innovation and Universities (PID2019-105583GB-C22/AEI/10.13039/501100011033) and the Catalan government (“Ajuts a grups consolidats” 2021SGR00315 and FI grant to C.B.-G. 2022FI_B 00150). The Ph.D. thesis was carried out under the Ph.D. program “Plant Biology and Biotechnology” of the Autonomous University of Barcelona (UAB). Additional support was provided by the Czech Science Foundation GAČR project no. 20-10878S to R.S. and F.K. and long-term research development project (RVO 67985939) of the Czech Academy of Sciences. Additional funds were obtained from the Norwegian Programme for Development, Research and Higher Education (NUFU; project AFROALP-II, no 2007/1058) and the Research Council of Norway (project SpeciationClock, no 274607) to C.B.Abstract 1. Introduction 2. Materials and Methods 2.1. Taxon Sampling 2.2. DNA Extraction, Library Preparation, Target Capture, and Sequencing 2.3. Molecular Data Processing and Phylogenetic Analyses 2.4. Divergence Time Estimation 2.5. Ancestral Range Estimation 3. Results 3.1. Alignment Processing and Filtering 3.2. Phylogenetic Analyses 3.3. Divergence Time and Ancestral Range Estimation 3.4. Number, Type, and Directionality Estimation of Biogeographical Events 4. Discussion 4.1. Utility of Target-Enrichment Strategies in Reconstructing the Radiation of Helichrysum 4.2. The Early History of Helichrysum and Colonization of Madagascar 4.3. Repeatedly Northwards 4.4. Repeatedly Upwards 5. Conclusions Supplementary Materials Author Contributions Funding Data Availability Statement Acknowledgments Conflicts of Interest Reference

Next generation flow for minimally-invasive blood characterization of MGUS and multiple myeloma at diagnosis based on circulating tumor plasma cells (CTPC)

Here, we investigated for the first time the frequency and number of circulating tumor plasma cells (CTPC) in peripheral blood (PB) of newly diagnosed patients with localized and systemic plasma cell neoplasms (PCN) using next-generation flow cytometry (NGF) and correlated our findings with the distinct diagnostic and prognostic categories of the disease. Overall, 508 samples from 264 newly diagnosed PCN patients, were studied. CTPC were detected in PB of all active multiple myeloma (MM; 100%), and smoldering MM (SMM) patients (100%), and in more than half (59%) monoclonal gammopathy of undetermined significance (MGUS) cases (p < 0.0001); in contrast, CTPC were present in a small fraction of solitary plasmacytoma patients (18%). Higher numbers of CTPC in PB were associated with higher levels of BM infiltration and more adverse prognostic features, together with shorter time to progression from MGUS to MM (p < 0.0001) and a shorter survival in MM patients with active disease requiring treatment (p <= 0.03). In summary, the presence of CTPC in PB as assessed by NGF at diagnosis, emerges as a hallmark of disseminated PCN, higher numbers of PB CTPC being strongly associated with a malignant disease behavior and a poorer outcome of both MGUS and MM