Solvency II Directive 2009/138/EC requires an insurance and reinsurance undertakings assessment of a Solvency Capital Requirement by means of the so-called “Standard Formula” or by means of partial ...or full internal models. Focusing on the first approach, the bottom-up aggregation formula proposed by the regulator allows for a capital reduction due to the diversification effect, according to the typical subadditivity property of risk measures. However, once the overall capital has been assessed no specific allocation formula is provided or required in order to evaluate the contribution of each risk source on the overall Solvency Capital Requirement. The aim of this paper is twofold. First, we provide a closed formula for capital allocation fully compliant with the Solvency II Capital Requirement assessed by means of the Standard Formula. The solution enables a top-down approach to assess the allocated Solvency Capital Requirement among the risks considered in the Solvency II multilevel aggregation scheme; we demonstrate that the allocation formula adopted is consistent with the Euler allocation principle. Second, a solution is found as a result of an optimum capital allocation problem based on a Return On Risk Adjusted Capital measure; we establish the equivalence between the Return On Risk Adjusted Capital optimization, when the risk adjusted capital is calculated according to the Standard Formula, and the Markowitz mean-variance optimization.
Insulin signaling is critical for neuroplasticity, cerebral metabolism as well as for systemic energy metabolism. In rodent studies, impaired brain insulin signaling with resultant insulin resistance ...(IR) modulates synaptic plasticity and the corresponding behavioral functions. Despite discoveries of central actions of insulin, in vivo molecular mechanisms of brain IR until recently have proven difficult to study in the human brain. In the current study, we leveraged recent technological advances in molecular biology and herein report an increased number of exosomes enriched for L1CAM, a marker predominantly expressed in the brain, in subjects with major depressive disorder (MDD) as compared with age- and sex-matched healthy controls (HC). We also report increased concentration of the insulin receptor substrate-1 (IRS-1) in L1CAM
exosomes in subjects with MDD as compared with age- and sex-matched HC. We found a relationship between expression of IRS-1 in L1CAM
exosomes and systemic IR as assessed by homeostatic model assessment of IR in HC, but not in subjects with MDD. The increased IRS-1 levels in L1CAM
exosomes were greater in subjects with MDD and were associated with suicidality and anhedonia. Finally, our data suggested sex differences in serine-312 phosphorylation of IRS-1 in L1CAM
exosomes in subjects with MDD. These findings provide a starting point for creating mechanistic framework of brain IR in further development of personalized medicine strategies to effectively treat MDD.
The lead was one of the main elements in the glazes used to colour ceramic tiles. Due to its presence, ceramic sludge has been a source of environmental pollution since this dangerous waste has been ...often spread into the soil without any measures of pollution control. These contaminated sites are often located close to industrial sites in the peri-urban areas, thus representing a considerable hazard to the human and ecosystem health. In this study, we investigated the lead transfer into the vegetation layer (
Phragmites australis
,
Salix alba
and
Sambucus nigra
) growing naturally along a Pb-contaminated ditch bank. The analysis showed a different lead accumulation among the species and their plant tissues.
Salix
trees were not affected by the Pb contamination, possibly because their roots mainly develop below the contaminated deposit. Differently,
Sambucus
accumulated high concentrations of lead in all plant tissues and fruits, representing a potential source of biomagnification.
Phragmites
accumulated large amounts of lead in the rhizomes and, considering its homogeneous distribution on the site, was used to map the contamination. Analysing the Pb concentration within plant tissues, we got at the same time information about the spread, the history of the contamination and the relative risks. Finally, we discussed the role of natural recolonizing plants for the soil pollution mitigation and their capacity on decreasing soil erosion and water run-off.
Aging is accompanied by profound changes in many physiological functions, leading to a decreased ability to cope with stressors. Many changes are subtle, but can negatively affect nutrient intake, ...leading to overt malnutrition. Poor oral health may affect food selection and nutrient intake, leading to malnutrition and, consequently, to frailty and sarcopenia. On the other hand, it has been highlighted that sarcopenia is a whole-body process also affecting muscles dedicated to chewing and swallowing. Hence, muscle decline of these muscle groups may also have a negative impact on nutrient intake, increasing the risk for malnutrition. The interplay between oral diseases and malnutrition with frailty and sarcopenia may be explained through biological and environmental factors that are linked to the common burden of inflammation and oxidative stress. The presence of oral problems, alone or in combination with sarcopenia, may thus represent the biological substratum of the disabling cascade experienced by many frail individuals. A multimodal and multidisciplinary approach, including personalized dietary counselling and oral health care, may thus be helpful to better manage the complexity of older people. Furthermore, preventive strategies applied throughout the lifetime could help to preserve both oral and muscle function later in life. Here, we provide an overview on the relevance of poor oral health as a determinant of malnutrition and sarcopenia.
Dentistry has evolved significantly with the introduction of digital technologies and materials; however, clinical evidence for the performance of the complete digital workflow for single ...implant–supported posterior crowns is lacking.
The purpose of this cross-sectional retrospective clinical study was to compare the clinical outcomes of 2 types of implant-supported crown used to replace a single missing posterior tooth in a completely digital workflow: transocclusal screw-retained monolithic lithium disilicate crowns versus transocclusal screw-retained monolithic zirconia crowns.
A total of 38 participants who had been provided with dental implants and transocclusal screw-retained monolithic lithium disilicate or zirconia single crowns were evaluated in the study. Clinical and esthetic outcomes were recorded after a 3-year follow-up.
Both groups had comparable clinical outcomes with a survival rate of 100%. In the lithium disilicate group, 89% of the participants were free of technical complications, and 95%, in the zirconia group. Only 1 patient experienced minor chipping affecting a lithium disilicate crown. All complications were considered minor and were easily resolved, and none of the participants required replacement of a crown. No biological complications were recorded in either group.
Within the limitations of this cross-sectional retrospective clinical study, monolithic lithium disilicate and zirconia screw-retained single crowns fabricated using computer-aided design and computer-aided manufacturing (CAD-CAM) and a fully digital workflow were found to be reliable and suitable clinical options for restoring a posterior missing tooth on a dental implant.
Background
Nowadays, due to the esthetic and social demands of patients, conventional staged protocols seem to be increasingly replaced by faster, one-step protocols. The purpose of the present ...systematic review is to assess the peri-implant soft tissue changes after immediate implant placement and provisionalization (IIPP) comparing patients treated with or without a sub-epithelial connective tissue graft (SCTG) when replacing a single tooth in the esthetic region.
Methods
The present systematic review was written following the PRISMA checklist. Immediate implants placed with a connective tissue graft and without one were compared. The researched primary outcomes were the mid-buccal mucosa level (MBML) facial soft tissue thickness (FSTT) and marginal bone loss (MBL). The weighted mean differences (WMD) were estimated for all three outcomes.
Results
The change in the mid-buccal mucosa level in the intervention group was significantly higher (WMD 0.54; 95% CI 0.33–0.75), with no indication of heterogeneity (I
2
= 16%). The facial soft tissue thickness increased significantly in the intervention group (WMD 0.79; 95% CI 0.37–1.22). The marginal bone loss was significantly higher in the control group (WMD 0.13; 95% CI 0.07–0.18), with no indication of heterogeneity (I
2
= 0%).
Conclusions
The results of the meta-analyses showed a statistically significant reduced change of the marginal bone loss and vestibular recession, as well as higher soft tissue thickness, when a graft was used. The included studies had a short observation time; therefore, studies with longer follow-ups are needed to confirm these findings.
Understanding how different combinations of plant functional traits contribute to species fitness is a question of considerable ecological interest, that can give insights into the mechanisms ...controlling community assembly, and into the processes by which climate change can modify plant community structure and composition. We investigated the changes in cover degree of three shrubs (Cistus monspeliensis, Dorycnium pentaphyllum and Helichrysum microphyllum) growing in a Mediterranean garrigue subjected for 11 years to a reduced rainfall regime, following a conceptual framework based on the two‐phase resource dynamic model: considering the seasonal drought typical of the Mediterranean climate, the two‐phases were identified based on high (pulse phase) and low (interpulse phase) soil water availability. We developed a parameter proportional to the whole plant photosynthesis (plant photosynthetic index, PPI), scaling up the leaf photosynthesis to canopy level, taking into account the different canopy densities and the fluctuations in leaf biomass due to summer leaf shedding. PPI was used to derive plant performance estimators for both pulse (maximum value reached by PPI, PPImax) and interpulse phase (duration of the exhaustion phase, Durep, when drought constrains PPI below the plant carbon compensation point determining carbon starvation). For each species the ratio between PPImax and Durep (named PPIred) was used as an index of plant performance. The reduced rainfall regime mainly decreased the performances of the dominant species C. monspeliensis, both limiting PPImax and extending Durep. Under both natural and the manipulated rainfall regime, PPIred was proportional to plant success, measured as the cover degree variation rate of the species. This result suggests that a mechanistic approach using functional traits to quantify the different performance of co‐occurring species can be used to investigate 1) the drivers of the medium‐term changes in species abundance and 2) the processes responsible for change in plant community composition under climate change.
The tree belowground compartment, especially fine roots, plays a relevant role in the forest ecosystem carbon (C) cycle, contributing largely to soil CO2 efflux (SR) and to net primary production ...(NPP). Beyond the well-known role of environmental drivers on fine root production (FRP) and SR, other determinants such as forest structure are still poorly understood. We investigated spatial variability of FRP, SR, forest structural traits, and their reciprocal interactions in a mature beech forest in the Mediterranean mountains. In the year of study, FRP resulted in the main component of NPP and explained about 70% of spatial variability of SR. Moreover, FRP was strictly driven by leaf area index (LAI) and soil water content (SWC). These results suggest a framework of close interactions between structural and functional forest features at the local scale to optimize C source–sink relationships under climate variability in a Mediterranean mature beech forest.
The capacity to forecast the effects of climate change on biodiversity largely relies on identifying traits capturing mechanistic relationships with the environment through standardized field ...experiments distributed across relevant spatial scales. The effects of short‐term experimental manipulations on local communities may overlap with regional climate gradients that have been operating during longer time periods. However, to the best of our knowledge, there are no studies simultaneously assessing such long‐term macroecological drivers with local climate manipulations.
We analysed this issue with springtails (Class Collembola), one of the dominant soil fauna groups, in a standardized climate manipulation experiment conducted across six European countries encompassing broad climate gradients. We combined community data (near 20K specimens classified into 102 species) with 22 eco‐morphological traits and reconstructed their phylogenetic relationships to track the evolution of adaptations to live at different soil depths, which is key to cope with desiccation. We then applied joint species distribution models to investigate the combined effect of the regional aridity gradient with the local experimental treatment (drought and warming) over the assembly of springtail communities and tested for significant trait–environment relationships mediating their community‐level responses.
Our results show (1) a convergent evolution in all three major collembolan lineages of species adapted to inhabit at different soil strata; (2) a clear signature of aridity selecting traits of more epigeic species at a biogeographical scale and (3) the association of short‐term experimental drought with traits related to more euedaphic life‐forms.
The hemiedaphic condition would be the plesiomorphic state for Collembola while the adaptations for an epigeic life would have been secondarily gained. Epigeic springtails are not only more resistant to drought, but also have a higher dispersal capacity that allows them to seek more favourable micro‐habitats after experiencing drier conditions. The observed relative edaphization of the springtail communities after short‐term experimental drought may thus be a transient community response.
The disparity between macroecological trends and fast community‐level responses after climate manipulations highlights the need of simultaneously assessing long‐term and short‐term drivers at broad spatial scales to adequately interpret trait–environment relationships and better forecast biodiversity responses to climate change.
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Resumen
La capacidad de predecir los efectos negativos del cambio climático sobre la biodiversidad depende en gran medida de identificar aquellos atributos que capturan relaciones mecánicas con el ambiente mediante experimentos manipulativos de campo distribuidos a escalas espaciales relevantes. No obstante, los efectos de las manipulaciones experimentales a corto plazo sobre las comunidades locales pueden solaparse con los gradientes climáticos regionales que han operado durante periodos de tiempo más prolongados. No obstante, de acuerdo a nuestro conocimiento, no hay estudios que hayan evaluado simultáneamente factores macroecológicos a largo plazo junto con manipulaciones climáticas a corto plazo a escalas espaciales relevantes.
Analizamos este asunto usando como ejemplo a los colémbolos (Clase Collembola), un importante grupo de la fauna del suelo, mediante un experimento de campo de manipulación climática estandarizado y llevado a cabo en 6 países europeos abarcando así amplios gradientes de temperatura y precipitación. Combinamos datos de comunidades de colémbolos (cerca de 20 mil especímenes clasificados en 102 especies) con 22 atributos eco‐morfológicos y reconstruimos sus relaciones filogenéticas para rastrear la evolución de las adaptaciones para vivir a distintas profundidades del suelo, lo cual es clave para lidiar con la sequedad. Aplicamos entonces modelos de distribución conjunta de especies para investigar el efecto combinado del gradiente regional de aridez con el tratamiento experimental local (sequía y calentamiento) sobre el ensamblado de las comunidades de colémbolos, y además, testamos la existencia de relaciones atributo‐ambiente significativas mediando las respuestas de las comunidades de colémbolos a las manipulaciones climáticas.
Nuestros resultados muestran: (1) una evolución convergente en los tres linajes principales de colémbolos de especies adaptadas a habitar en distintos estratos del suelo. (2) una clara signatura de la aridez seleccionando atributos de especies más epigeas a escala biogeográfica, y (3) la asociación de la sequía experimental a corto plazo con atributos relacionados con formas de vida más eu‐edáficas.
La condición hemiedáfica seria el estado plesiomórfico de Collembola mientras que las adaptaciones a una vida completamente epigea habrían sido desarrolladas secundariamente y de manera repetida en distintos linajes. Los colémbolos epigeos son más resistentes a la sequía pero también presentan una capacidad de dispersión mayor lo cual les permite buscar activamente micro‐hábitats más favorables tras experimentar condiciones ambientales adversas. La relativa edafización de las comunidades de colémbolos observada tras la sequía experimental a corto plazo seria por lo tanto una respuesta transitoria de la comunidad.
La disparidad entre las tendencias macroecológicas y las rápidas respuestas a nivel de comunidad tras las manipulaciones climáticas ponen de manifiesto la necesidad de evaluar simultáneamente factores de cambio ambiental operando a corto y a largo plazo, y a escalas espaciales amplias, para poder interpretar adecuadamente las relaciones entre atributos y ambiente y así poder predecir mejor las respuestas de la biodiversidad al cambio climático.
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The growing relevance of risk-based valuations of insurance contracts has stimulated the extension of the traditional deterministic lapse rate models towards a dynamic modelling. A popular dynamic ...model uses deterministic lapse rates as base rates and dynamic adjustment factors, generally assuming a relationship between lapses and one or more economic factors to describe policyholder behaviour. This relationship is generally represented by an S-Shaped function. This implies a monotonic increase in lapse rate by increasing the economic variable, usually set equal to a “market spread” between a benchmark rate and the policy crediting rate. In this paper, we assume a different policyholder behaviour, based on the assumption that the policyholder does not modify his/her behaviour for small values of the market spread. Hence, for a better description of such behaviour, the double-sigmoid function appears to be more adequate. The double-sigmoid function is obtained as a combination of two logits in their sum or product. Theoretical features and practical applications of the model are discussed.
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