The structure and ecological function of the interactions between plants and arbuscular mycorrhizal fungi through multilayer networks

Arbuscular mycorrhizas are one of the most frequent mutualisms in terrestrial ecosystems. Although studies on plant mutualistic interaction networks suggest that they may leave their imprint on plant community structure and dynamics, this has not been explicitly assessed. Thus, in the context of plant-fungi interactions, studies explicitly linking plant-mycorrhizal fungi interaction networks with key ecological functions of plant communities, such as recruitment, are lacking. 2. In this study, we analyse, in two Mediterranean forest communities of southern Iberian Peninsula, how plant-arbuscular mycorrhizal fungi (AMF) networks modulate plant-plant recruitment interaction networks. We use a new approach integrating plant-AMF and plant recruitment networks into a single multilayer structure. We also develop a new metric (Interlayer Node Neighbourhood Integration, INNI) to explore the impact of a given node on the structure across layers. 3. The similarity of plant species in their AMF communities is positively related to the observed frequency of recruitment interactions in the field. Results reveal that properties of plant-AMF networks, such as plant degree and centrality, can explain about the properties of plant recruitment network, such as in-and out-degree (i.e. sapling bank and canopy service) and its modular structure. However, these relationships differed between the two forest communities. Finally, we identify particular AMF that contribute to integrate the neighbourhood of recruitment interactions between plants. 4. This multilayer network approach is useful to explore the role of plant-AMF interactions on recruitment, a key ecosystem function enhanced by fungi. Results provide evidence that the complex structure of plant-AMF interactions impacts functional and structurally plant-plant interactions, which in turn may potentiallyMinisterio de Ciencia e Innovación, Grant/ Award Number: CGL2015-69118- C2- 2- P and PGC2018-100966- B- I0

Modulation of European air quality by Euro-Atlantic weather regimes

CRUE-CSIC (Acuerdos Transformativos 2022)This paper analyses the dependency of regional air pollution in Europe on the atmospheric circulation as represented by a set of 8 weather regimes (WRs). For this purpose, daily average PM2.5 concentrations and daily maximum concentrations of O3, NO2 and CO obtained from an atmospheric composition reanalysis have been used. The results indicate that the pollutant concentrations change substantially with the occurrence of each WR according to the associated circulation patterns. In the extended winter, the responses of PM2.5, NO2 and CO are quite similar, with zonal circulation regimes leading to better air quality than anticyclonic regimes linked to steady flows over Europe. On the other hand, the spatial patterns of O3 anomalies under most WRs resemble those of temperature in the extended summer as temperature enhancements favour the photochemical production of O3. The WR characterized by anticyclonic anomalies over Scandinavia leads to the highest concentrations at continental scale and is concurrent with an increased probability of exceeding the poor air quality limits of winter PM2.5 and summer O3 in most European countries. It is also found that a multiple linear regression model on the monthly frequency of WRs can explain a considerable fraction of the intermonthly variability of concentration anomalies over large parts of Europe regardless of the pollutant, with R2 values around 0.6–0.8 over large regions. Overall, the application of these models to sub-seasonal weather forecasts does not seem to bring major improvements to the prediction of month-ahead concentration anomalies as compared to the climatology. The poor skill of sub-seasonal forecasts in predicting the WRs for lead times beyond 15 days limits the forecast capability. However, these results open the possibility of extending current air quality forecast to scales of 5–10 days at a low cost in a near future.Depto. de Física de la Tierra y AstrofísicaFac. de Ciencias FísicasTRUEMinisterio de Economía y Competitividad (MINECO)Ministerio de Educación, Cultura y Deporte (MECD)pu

Estudio del período de vibración de puentes con vigas de acero en Panamá

In this article the main frequency of vibration obtained in 31 spans of steel beam bridges are presented, and studied together with other 25 steel beam bridges vibration frequencies presented in previous studies. An equation that estimates the main period of vibration as a function of the span length of these bridges is presented. Additionally, matching of frequency of vibration in adjacent spans with different lengths was observed in some non-continuous-beam multi-span bridges; this phenomena is considered to be related to forced vibration in the shorter spans caused by the natural vibration of the longest spans. In addition, an equation to estimate an upper bound period of vibration as a reference to identify atypical bridges, whose vibration periods are considerably far from the trend.En este artículo se presenta la frecuencia de vibración principal de 31 luces de puentes de viga de acero, y se estudian en conjunto con la frecuencia de vibración de otras 25 luces de puentes de acero presentadas en estudios anteriores. Se presenta una ecuación que estima el período de vibración principal en función de la longitud de la luz estudiada. En algunos puentes se observó una sincronización de la frecuencia de vibración en tramos adyacentes (los cuales presentan diferentes longitudes entre ellos) en puentes de varias luces con vigas no continuas; se propone que este fenómeno está relacionado con la vibración forzada en los tramos más cortos, causada​ por la vibración natural de las luces adyacentes más largas. Además, una ecuación para estimar el período de vibración que se puede utilizar como límite superior, una referencia para identificar puentes atípicos, cuyos períodos de vibración son considerablemente mayores a la tendenci

Biophysical Processes Determining the Connectivity of the Alboran Sea Fish Populations

This chapter revises biogeophysical issues of connectivity processes for fish populations in the Alboran Sea—Strait of Gibraltar—Gulf of Cadiz area. Connectivity of early life history stages between distant spawning grounds is crucial to incorporate vital developmental rates that condition survival probabilities at critical ontogenic stages. Hydrodynamics is pivotal to the process and most particular for pelagic species originating from adult fish adapted to recurrent patterns. Therefore, special focus has been placed on the hydrodynamics of the region, particularly on the Alboran Sea where the swift and energetic eastward-flowing Atlantic Jet entering the basin from the Strait of Gibraltar determines the surface circulation patterns. The Jet establishes an obvious zonal west-to-east connectivity, prevents the one in the opposite east-to-west direction and works as a hydrodynamic barrier that hampers the north-to-south connectivity. The chapter addresses these processes, discusses possible mechanisms to achieve connectivity between north and south shores, which have to overcome the hydrodynamic barrier, and assesses the feasibility of east-to-west connectivity by means of intermediate-depth currents. Implications on the populations and ecosystems of the Alboran Sea and on the three main harvested species potentially affected by hydrodynamic connectivity in the basin (European hake, the sardine, and the blackspot seabream) are also commented.Preprin

Synthesis of a cubic Ti(BCN) advanced ceramic by a solid-gas mechanochemical reaction

In this work, a titanium boron carbonitride advanced ceramic was successfully synthesised by a solid-gas mechanochemical reaction in a planetary ball mill from a mixture of elemental Ti, B, and C under nitrogen atmosphere. This material, with a general formula of Ti(BCN), exhibits a face-centred cubic structure (NaCl type) that is analogous to Ti(CN). This phase was gradually formed with sufficient milling time as a result of diffusional processes, which were permitted by the reduction of the energy in the system caused by the decrease in the spinning rate of the planetary ball mill. In contrast, under more energetic milling conditions, a mechanically induced self-sustaining reaction (MSR) took place, leading to the formation of a TiB2-Ti(CN) ceramic composite. The microstructural characterisation revealed that Ti(BCN) was composed of ceramic particles constituted of misoriented nanocrystalline domains. B, C and N were optimally distributed in the Ti(BCN) phase. The TiB2-Ti(CN) ceramic composite was composed of micrometric and nanometric particles homogeneously distributed. Additionally, the nitrogen content obtained for Ti(BCN) was higher than for the Ti(CN) phase in the composite material.Spanish government No. MAT2014–52407-RUniversity of Seville VIPPIT-2018-I.5Laboratory for Nanoscopies and Spectroscopies (LANE) at the ICMS-CSI

Hemiepifisiodesis femoral distal mediante biomateriales reabsorbibles: Estudio experimental en el conejo

Se valoró experimentalmente un implante triangular compuesto de 3 tornillos metálicos unidos por un filamento de PDS II o Tendofil como método de epifisiodesis. Se utilizaron conejos esqueléticamente inmaduros, divididos en 4 Grupos, según el seguimiento postoperatorio (1,2,3 y 4 meses), subdivididos a su vez en 2 subgrupos según el filamento empleado. Se colocó el implante en la cara lateral de la epífisis femoral distal izquierda. La extremidad posterior derecha sirvió como control practicándose estudios radiológicos, histológicos e histomorfométrico. Las extremidades intervenidas presentaron una desviación en valgo significativa respecto a las control. El implante utilizado consiguió el frenado misario con ambos filamentos. Durante el primer mes, la eficacia del implante reabsorbible fue comparable al metálico. Posteriormente, el metálico resultó más eficaz. Los estudios histológicos e histomorfométrico mostraron un frenado asimétrico de la fisis intervenida. No hubo daños fisarios en relación con la degradación del implante reabsorbible. Nuestros resultados sugieron el diseño de implantes reabsorbibles en la cirugía del cartílago de crecimiento.A triangular implant compound by 3 metallic screws united by a filament (PDS II vs. Tendofil) as method of experimental epiphysiodesis was evaluated. They were used 32 immature rabbits, divided into 4 Groups acoording to the follow-up (1.2.3. and 4 months), and subdivided according to the employed filament. The implant was located at the lateral face of the distal left femoral epiphysis. The right extremity served as control. Radiographic, histologic and histomorphometric studies were performed. The operated legs presented a significant valgus deviation as compared to controls. The epiphysiodesis was achieved with both types of filaments. During the first month, the efficiency of the absorbable implant was comparable to the metallic. Thereafter, the metallic implant results more effective. Histologic and morphometric studies showed the hemiepiphysiodesis. No physeal damaged in relationship to the degradation of the absorbable implant was observed. Our results suggests the use of absorbable implant in growth plate surgery

RAPD-PCR molecular analysis of the threatened Cabrera’s vole populations in the Iberian Peninsula

Optimal management and conservation programs of the threatened Cabrera’s vole require investigating potential molecular genetic markers in the genomic background, if the few remaining fragile populations are to be conserved. A collection of 30 Cabrera’s vole representing four populations in Spain and Portugal was characterized by 134 RAPD-PCR markers. Molecular analyses did not detect low level of the genetic diversity or population bottlenecks in all studied populations, in discordance with the expectation of low level of viability of the Cabrera’s vole. The results described Cabrera’s vole populations as a single genetic unit with slightly restricted gene flow. Phylogenetic reconstruction suggested genetic differentiation between Northern and Southern Cabrera’s vole populations, with the basal branches formed by the southern populations, which may be an evidence of the southern origin of Iberian vole ancestral population. To our knowledge, this is the first study on the genetic diversity of Microtus cabrerae, which may have further application for the conservation programs of this threatened species of Iberian vole.Keywords: Microtus cabrerae, RAPD-PCR, Spain, Portugal, gene flow, genetic diversity, bottleneck, conservationAfrican Journal of Biotechnology Vol. 12(26), pp. 4065-407