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AbstractA well-known theorem of Philip Hall states that if a group Ghas a nilpotent normal subgroup Nsuch that $G/N'$ is nilpotent, then Gitself is nilpotent. We say that a group class 픛 is a Hall classif it contains every group Gadmitting a nilpotent normal subgroup Nsuch that $G/N'$ belongs to 픛. Hall classes have been considered by several authors, such as Plotkin [‘Some properties of automorphisms of nilpotent groups’, Soviet Math. Dokl.2(1961), 471–474] and Robinson [‘A property of the lower central series of a group’, Math. Z.107(1968), 225–231]. A further detailed study of Hall classes is performed by us in another paper [‘Hall classes of groups’, to appear] and we also investigate the behaviour of the class of finite-by-픜 groups for a given Hall class 픜 [‘Hall classes in linear groups’, to appear]. The aim of this paper is to prove that for most natural choices of the Hall class 픜, also the classes $(\mathbf{L}\mathfrak{F})\mathfrak{Y}$ and 픅픜 are Hall classes, where L픉 is the class of locally finite groups and 픅 is the class of locally finite groups of finite exponent.

This paper provides an account of results and methods from the theory of infinite groups admitting only finitely many normalizers of subgroups with a given property. Some new statements on this subject are also proved.

Let Gbe an abelian group. The aim of this short paper is to describe a way to identify pure subgroups Hof Gby looking only at how the subgroup lattice L(H)embeds in L(G). It is worth noticing that all results are carried out in a local nilpotent context for a general definition of purity.

Current manufacturing techniques in the construction sector are slow, expensive and constrained in terms of architectural shapes. In other manufacturing sectors (such as automotive and aerospace) the use of automated construction systems significantly improved the safety, speed, quality and complexity of products. To realize real-scale structural elements for construction applications without ideally any geometrical constraints either in size or shape, the most suitable manufacturing solution for metallic elements is a directed energy deposition (DED) process referred to as wire-and-arc additive manufacturing (WAAM). The main advantage of WAAM relies on the possibility to create new shapes and forms following the breakthrough design tools for modern architecture as algorithm-aided design. At the same time, the printed part ensures high structural performances with reduced material use with respect to the conventional solution. The study presents a new approach called “blended” structural optimization, which blends topology optimization with basic principles of structural design and manufacturing constraints proper of WAAM technology, towards the realization of new efficient structural elements. The approach is applied to the case study of a I-type stainless steel beam on a multi-storey frame building. The approach could pave the way towards an efficient use of WAAM process to produce a new generation of structurally optimized elements for construction, with a more conscious use of the optimization tools and an efficient application of metal 3D printing.

Boolean Network Tomography (BNT) aims at identifying failures of internal network components by means of end-to-end monitoring paths. However, when the number of failures is not known a priori, failure identification may require a huge number of monitoring paths. We address this problem by designing a Bayesian approach that progressively selects the next path to probe on the basis of its expected information utility, conditioned on prior observations. As the complexity of the computation of posterior probabilities of node failures is exponential in the number of failed paths, we propose a polynomial-time greedy strategy which approximates these values. To consider aging of information in dynamic failure scenarios where node states can change during a monitoring period, we propose a monitoring technique based on a sliding observation window of adaptive length. By means of numerical experiments conducted on real network topologies we demonstrate the practical applicability of our approach, and the superiority of our algorithms with respect to state of the art solutions based on classic BNT as well as sequential group testing.

Background: The European Working Group on Sarcopenia in Older People (EWGSOP2) recently revised its definition and diagnostic criteria for sarcopenia, placing muscle strength at the forefront. The pathogenesis of dynapenia (or low muscle strength) is still not fully understood, but there is emerging evidence that central neural factors constitute critical determinants. Methods: Our cross-sectional study included 59 community-dwelling older women (mean age 73.1 ± 4.9 years). Participants underwent detailed skeletal muscle assessments for muscle strength defined by handgrip strength and chair rise time measurements using the recently published EWGSOP2 cut-off points. Functional magnetic resonance imaging (fMRI) was assessed during the performance of a cognitive dual-task paradigm, consisting of a baseline, two single-tasks (motor and arithmetic) and one dual-task (motor and arithmetic combined). Results: Forty-seven percent (28/59) of participants were classified as dynapenic. fMRI results revealed a differential recruitment of motor circuits in the brain during the dual-task condition in dynapenic as compared with non-dynapenic participants. In particular, while the brain activity during the single-tasks did not differ between the two groups, only during the dual-task non-dynapenic participants showed significant increased activation in dorsolateral prefrontal and premotor cortex, and in supplementary motor area as compared to dynapenic participants. Conclusion: Our results point to a dysfunctional involvement of brain networks associated with motor control in dynapenia in a multi-tasking paradigm. A better knowledge of the link between dynapenia and brain functions could provide new impulses in the diagnosis and interventions for sarcopenia.

In the planning and management of civil facilities, geospatial data plays a crucial role. Traditionally, the Geographic Information System (GIS) is the tool for storing, manipulating and analysing spatial and geographic data.

X-linked hypophosphataemia (XLH) is the most frequent cause of hypophosphataemia-associated rickets of genetic origin and is associated with high levels of the phosphaturic hormone fibroblast growth factor 23 (FGF23). In addition to rickets and osteomalacia, patients with XLH have a heavy disease burden with enthesopathies, osteoarthritis, pseudofractures and dental complications, all of which contribute to reduced quality of life. This Consensus Statement presents the outcomes of a working group of the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases, and provides robust clinical evidence on management in XLH, with an emphasis on patients’ experiences and needs. During growth, conventional treatment with phosphate supplements and active vitamin D metabolites (such as calcitriol) improves growth, ameliorates leg deformities and dental manifestations, and reduces pain. The continuation of conventional treatment in symptom-free adults is still debated. A novel therapeutic approach is the monoclonal anti-FGF23 antibody burosumab. Although promising, further studies are required to clarify its long-term efficacy, particularly in adults. Given the diversity of symptoms and complications, an interdisciplinary approach to management is of paramount importance. The focus of treatment should be not only on the physical manifestations and challenges associated with XLH and other FGF23-mediated hypophosphataemia syndromes, but also on the major psychological and social impact of the disease.

We study the behaviour, when p→+∞p\to +\infty , of the first p-Laplacian eigenvalues with Robin boundary conditions and the limit of the associated eigenfunctions. We prove that the limit of the eigenfunctions is a viscosity solution to an eigenvalue problem for the so-called ∞\infty -Laplacian. Moreover, in the second part of the article, we focus our attention on the p-Poisson equation when the datum ffbelongs to L∞(Ω){L}^{\infty }\left(\Omega )and we study the behaviour of solutions when p→∞p\to \infty .

Among various additive manufacturing (AM) technologies, wire-and-arc additive manufacturing (WAAM) is one of the most suitable for the production of large-scale metallic components, also suggesting possible applications in the construction field. Several research activities have been devoted to the WAAM of steels and titanium alloys and, recently, the application of WAAM to aluminum alloys has also been explored. This paper presents the microstructural and mechanical characterization of WAAM plates produced using a commercial ER 5183 aluminum welding wire. The aim is to evaluate the possible anisotropic behavior under tensile stress of planar elements, considering three different extraction directions in relation to the deposition layer: longitudinal (L), transversal (T) and diagonal (D). Compositional, morphological, microstructural and fractographic analyses were carried out to relate the specific microstructural features induced by WAAM to the tensile properties. An anisotropic behavior was found in regard to the specimen orientation, with the lowest strength and ductility found on T specimens. Reasoning to this was found in the presence of microstructural discontinuities unfavorably oriented with regard to the tensile direction. The results of tensile tests also highlighted an overall good mechanical behavior, comparable to that of conventional AA5083-O sheets, suggesting future use in the realization of very complex geometries and optimized shapes for lightweight structural applications.

In 1958, Philip Hall (Ill J Math 2:787–801, 1958) proved that if a group Ghas a nilpotent normal subgroup Nsuch that G/N′is nilpotent, then Gis nilpotent. The scope of Hall’s nilpotency criterion is not restricted to group theory, and in fact similar statements hold for Lie algebras and more generally for algebraically coherent semiabelian categories (see Chao in Math Z 103:40–42, 1968; Gray in Adv Math 349:911–919, 2019; Stitzinger in Ill J Math 22:499–505, 1978). We say that a group class Xis a Hall classif it contains every group Gadmitting a nilpotent normal subgroup Nsuch that G/N′belongs to X. Thus, Hall’s nilpotency criterion just asserts that nilpotent groups form a Hall class. Many other relevant classes of groups have been proved to be Hall classes; for example, Plotkin (Sov Math Dokl 2:471–474, 1961) and Robinson (Math Z 107:225–231, 1968) proved that locally nilpotent groups and hypercentral groups form Hall classes. Note that these generalizations also hold if groups are replaced by other algebraic structures, for example Lie algebras (see Stitzinger in Ill J Math 22:499–505, 1978). The aim of this paper is to develop a general theory of Hall classes of groups, that could later be reasonably extended to Lie algebras. Among other results, we prove that many natural types of generalized nilpotent groups form Hall classes, and we give examples showing in particular that the class of groups having a finite term in the lower central series is not a Hall class, even if we restrict to the universe of linear groups.

In this paper we characterize, in terms of their conjugacy classes, linear groups Gsuch that G/ζk(G)belongs to a certain group class Xfor several natural choices of X. Moreover, a description is given of linear groups with restrictions on layers.

Background: Fear of falling is highly prevalent in older adults and associated with numerous negative health events. The main objective of this study was to validate a scale to assess fear of falling, based on performance in real situation (Perform-FES), in a hospitalized geriatric population. Methods: In this cross-sectional study, 55 patients (mean age: 85.3 years; 58% women) hospitalized in a geriatric hospital in Geneva (Switzerland) were enrolled. The Perform-FES scale was administered to all patients in conjunction with four other fear of falling scales. We determined the floor and ceiling effects, internal consistency, reliability, construct validity, and discriminative power of the Perform-FES scale. Results: The Perform-FES scale did not demonstrate any significant floor or ceiling effect. It had a good internal consistency (Cronbach’s alpha = 0.78) and an excellent reliability (intraclass correlation coefficient = 0.94). Regarding convergent validity, good correlations were shown between the score obtained on the Perform-FES scale and those obtained on other fear of falling scales. Also, the Perform-FES scale was able to discriminate patients with severe functional impairments (area under the ROC curve = 0.81) and had significantly better discriminating performance than other fear of falling scales. Conclusion: Findings suggest that the Perform-FES scale has good psychometric properties and may be a relevant tool to assess fear of falling in a geriatric hospitalized population. Future research should focus in particular on assessing the sensitivity to change and the predictive value of this scale in longitudinal studies, and its validity in other populations.

Background: In 2016, an expert working group was convened under the auspices of the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) and formulated consensus recommendations for the conduct of clinical trials for drugs to prevent or treat sarcopenia. Aims: The objective of the current paper is to provide a 2020 update of the previous recommendations in accordance with the evidence that has become available since our original recommendations. Methods: This paper is based on literature reviews performed by members of the ESCEO working group and followed up with face to face meetings organized for the whole group to make amendments and discuss further recommendations. Results: The randomized placebo-controlled double-blind parallel-arm drug clinical trials should be the design of choice for both phase II and III trials. Treatment and follow-up should run at least 6 months for phase II and 12 months for phase III trials. Overall physical activity, nutrition, co-prescriptions and comorbidity should be recorded. Participants in these trials should be at least 70-years-old and present with a combination of low muscle strength and low physical performance. Severely malnourished individuals, as well as bedridden patients, patients with extremely limited mobility or individuals with physical limitations clearly attributable to the direct effect of a specific disease, should be excluded. Multiple outcomes are proposed for phase II trials, including, as example, physical performance, muscle strength and mass, muscle metabolism and muscle-bone interaction. For phase III trials, we recommend a co-primary endpoint of a measure of functional performance and a Patient Reported Outcome Measure. Conclusion: The working group has formulated consensus recommendations on specific aspects of trial design, and in doing so hopes to contribute to an improvement of the methodological robustness and comparability of clinical trials. Standardization of designs and outcomes would advance the field by allowing better comparison across studies, including performing individual patient-data meta-analyses, and different pro-myogenic therapies.

This paper has two souls. On one side, it is a survey on (infinite) groups in which certain systems of subgroups are complemented (like for instance the abelian subgroups). On another side, it provides generalizations and new, easier proofs of some (un)known results in this area.

Recently, the F1FO-ATP synthase, due to its dual role of life enzyme as main adenosine triphosphate (ATP) maker and of death enzyme, as ATP dissipator and putative structural component of the mitochondrial permeability transition pore (mPTP), which triggers cell death, has been increasingly considered as a drug target. Accordingly, the enzyme offers new strategies to counteract the increased antibiotic resistance. The challenge is to find or synthesize compounds able to discriminate between prokaryotic and mitochondrial F1FO-ATP synthase, exploiting subtle structural differences to kill pathogens without affecting the host. From this perspective, the eukaryotic enzyme could also be made refractory to macrolide antibiotics by chemically produced posttranslational modifications. Moreover, because the mitochondrial F1FO-ATPase activity stimulated by Ca2+instead of by the natural modulator Mg2+is most likely involved in mPTP formation, effectors preferentially targeting the Ca2+-activated enzyme may modulate the mPTP. If the enzyme involvement in the mPTP is confirmed, Ca2+-ATPase inhibitors may counteract conditions featured by an increased mPTP activity, such as neurodegenerative and cardiovascular diseases and physiological aging. Conversely, mPTP opening could be pharmacologically stimulated to selectively kill unwanted cells. On the basis of recent literature and promising lab findings, the action mechanism of F1and FOinhibitors is considered. These molecules may act as enzyme modifiers and constitute new drugs to kill pathogens, improve compromised enzyme functions, and limit the deathly enzyme role in pathologies. The enzyme offers a wide spectrum of therapeutic strategies to fight at the molecular level diseases whose treatment is still insufficient or merely symptomatic.

The analyses of the structural damages detected on the Italian churches after the recent earthquakes (Emilia 2012, Umbria-Marche 2016) highlighted the high vulnerability to the overturning of the façades. The façades collapse mechanisms are strongly dependent on the connection details between orthogonal masonry walls, the windows, the construction techniques and the possible restraining horizontal elements, such as tie-beams, bi-lateral connected roof, etc. Several studies focus on the evaluation of vulnerability of the church façades using different approaches, from global analyses (FEM and /or Discrete Element Methods) of the entire building, to local analyses (linear and non-linear kinematic approaches). The aims of the present paper is to use the method based on capacity spectra to evaluate the vulnerability of the church facades and the optimization of specific devices as tie-rods to improve their seismic behavior. The non-linear approach is now accepted by several standards regarding the evaluation of risks of collapse mechanisms for masonry walls of the facades. Appropriate devices have been considered in order to calibrate the capacity curve and to optimize the interventions. The out of plane rotation of blocks can be modified with various elasto-perfect-plastic tendons with appropriate retentions (while composite materials could be used to preserve integrity of blocks). The tendons can be allocated in proper location and the length of each calibrated to best determine their stiffness. This procedure have been here applied to the study of the façade of Aula Magna S. Lucia of the Bologna University, considering also the problem of the interaction with the structure of the roof.

The main purpose of this paper is to investigate the behaviour of uncountable groups of cardinality $\aleph$in which all proper subgroups of cardinality $\aleph$are nilpotent. It is proved that such a group $G$is nilpotent, provided that $G$has no infinite simple homomorphic images and either $\aleph$has cofinality strictly larger than $\aleph _{0}$or the generalized continuum hypothesis is assumed to hold. Furthermore, groups whose proper subgroups of large cardinality are soluble are studied in the last part of the paper.

Structural Health Monitoring (SHM) has a crucial role in the diagnosis and conservation of historical buildings, which are typically characterized by articulated fabrics, constructed over decades using different materials and construction techniques. All these issues lead to very complex structural behaviour whose reliable assessment cannot disregard from a sound interpretation of data from SHM systems. SHM systems can be classified into (i) static systems, monitoring the long term time evolutions of specific quantities (such as amplitude of cracks, inclination of walls, relative distances, etc.) and (ii) dynamic systems, continuously monitoring the dynamic response (velocities, accelerations) in order to gather information upon overall dynamic properties such as natural frequencies, mode shapes and damping ratios. The recorded raw data need to be processed in order to distinguish eventual evolutionary trends from the seasonal and daily variations related to thermal effects. In the present work, a simple unified approach for data interpretation acquired from both static and dynamic SHM systems installed in historical buildings is presented. The approach is aimed at: (i) introducing reference quantities for interpretation of seasonal and daily variations, (ii) providing order of magnitudes of reference quantities and (iii) identifying eventual evolutionary trends which could be related to the presence of potential structural criticalities. The approach is illustrated referring to the “Two Towers” of Bologna.

Alzheimer′s disease has recently emerged as a possible field of application for PDE4D inhibitors (PDE4DIs). The great structure similarity among the various PDE4 isoforms and, furthermore, the lack of the full length crystal structure of the enzyme, impaired the rational design of new selective PDE4DIs. In this paper, with the aim of exploring new insights into the PDE4D binding, we tackled the problem by performing a computational study based on docking simulations combined with molecular dynamics (D‐MD). Our work uniquely identified the binding mode and the key residues involved in the interaction with a number of in‐house catechol iminoether derivatives, acting as PDE4DIs. Moreover, the new binding mode was tested using a series of analogues previously reported by us and it was used to confirm their key structural features to allow PDE4D inhibition. The binding model disclosed within the current computational study may prove to be useful to further advance the design and synthesis of novel, more potent and selective, PDE4D inhibitors.

The porticoes, together with medieval masonry towers, are the architectural element which mainly characterizes the city of Bologna, northern Italy. These porticoes, which extend all inside the city centre for a total length of almost 40 kilometres, have a high artistic and cultural relevance at the point that they are candidates as “Unesco World Heritage Site”. One of portico of highest heritage value is that next to the church of Santa Maria dei Servi, which is suffering important structural pathologies requiring urgent strengthening interventions. The ones strictly necessary to preserve the stability have been already implemented. It is known that for historical constructions appropriate strategies of interventions are to be adopted with special attention in the aspects related to the compatibility, durability, integrity of the original configuration. The aim of this paper is to identify the main criticalities and priorities of interventions. Based on the identified criticalities and priorities possible strategies of interventions are finally identified. A possible cause of the actual bad state of conservation could be related to the continues vibrations induced by the traffic. For this reason, measurements noises have been recently conducted by the Italian National Institute of Geophysics and Volcanology (INGV) in order to quantify their influence of the stress levels of the columns of the portico.

Many design methods for the design of viscous dampers to be inserted in building structures are available in the scientific literature and building codes. Among others, the authors proposed a five-step procedure guiding the practioner from the choice of a target reduction in the seismic response of the structural system (with respect to the response of a structure without any additional damping devices), to the identification of the corresponding damping ratio and the mechanical characteristics of the commercially available viscous dampers. The original procedure required the development of numerical simulations for the evaluations of the peak inter-storey velocity profiles, necessary for the evaluation of the non-linear damping coefficient. More recently, a fully analytical version of the 5-step procedure (direct) has been also introduced. In the present work, an application of the direct procedure for a three-storey school building is presented.

To describe the clinical and biochemical profile of patients with primary hyperparathyroidism (PHPT) of the Swiss Hyperparathyroidism Cohort, with a focus on neurobehavioral and cognitive symptoms and on their changes in response to parathyroidectomy. From June 2007 to September 2012, 332 patients were enrolled in the Swiss PHPT Cohort Study, a nationwide prospective and non-interventional project collecting clinical, biochemical, and outcome data in newly diagnosed patients. Neuro-behavioral and cognitive status were evaluated annually using the Mini-Mental State Examination, the Hospital Anxiety and Depression Scale, and the Clock Drawing tests. Follow-up data were recorded every 6 months. Patients with parathyroidectomy had one follow-up visit 3–6 months’ postoperatively. Symptomatic PHPT was present in 43 % of patients. Among asymptomatic patients, 69 % (131/189) had at least one of the US National Institutes for Health criteria for surgery, leaving thus a small number of patients with cognitive dysfunction or neuropsychological symptoms, but without any other indication for surgery. At baseline, a large proportion showed elevated depression and anxiety scores and cognitive dysfunction, but with no association between biochemical manifestations of the disease and test scores. In the 153 (46 %) patients who underwent parathyroidectomy, we observed an improvement in the Mini-Mental State Examination (P= 0.01), anxiety (P= 0.05) and depression (P= 0.05) scores. PHPT patients often present elevated depression and anxiety scores and cognitive dysfunction, but rarely as isolated manifestations. These alterations may be relieved upon treatment by parathyroidectomy.

Aluminum is a promising material as an alternative green energy carrier thanks to its very high volumetric energy density and full recyclability. Aluminum oxidation with steam in the temperature range of 600–900 °C is investigated as an innovative and promising methodology for aluminum conversion resulting in hydrogen and heat production. Reaction times, hydrogen production rate and yield are assessed varying operational parameters such as temperature, steam to aluminum ratio, and gas hourly space velocity within the reactor. The conversion yield of aluminum is assessed at 73.13% at 900 °C and ambient pressure, with reaction times comparable with the one reported in the literature for water oxidation in batch‐pressurized reactors. Moreover, over 750 °C, alumina is produced in microparticles, allowing reactor operating times up to 1 h without incurring in the clogging effect. The obtained results are promising for the continuous operating condition of a future full‐scale reactor. Aluminum is a promising green energy carrier thanks to its very high volumetric energy density (>23 kWh L−1) and full recyclability. Its conversion reaction with steam at high temperature (600–900 °C) results in hydrogen and heat production. The conversion yield of aluminum is assessed at 73.13% after 1 h at 900 °C and ambient pressure.

It is proved that if $$G$$ G is a strongly locally graded group of infinite rank whose proper subgroups of infinite rank are (locally finite)-by-nilpotent, then $$G$$ G itself is (locally finite)-by-nilpotent. A corresponding result is also obtained for groups whose proper subgroups of infinite rank are (locally finite)-by-(locally nilpotent).

Activated Protein C (APC) is a multifunctional serine protease, primarily known for its anticoagulant function in the coagulation system. Several studies have already elucidated its role in counteracting apoptosis and inflammation in cells, while significant effort is still ongoing for defining its involvement in sepsis. Earlier literature has shown that the antiseptic function of APC is mediated by its binding to leukocyte integrins, which is due to the presence of the integrin binding motif Arg-Gly-Asp at the N-terminus of the APC catalytic chain. Many natural mutants have been identified in patients with Protein C deficiency diagnosis including a variant of specificity pocket (Gly216Asp). In this work, we present a molecular model of the complex of APC with αVβ3 integrin obtained by protein–protein docking approach. A computational analysis of this variant is hereby presented, based on molecular dynamics and docking simulations, aiming at investigating the effects of the Gly216Asp mutation on the protein conformation and inferring its functional implications. Our study shows that such mutation is likely to impair the protease activity while preserving the overall protein fold. Moreover, superposition of the integrin binding motifs in wild-type and mutant forms suggests that the interaction with integrin can still occur and thus the mutant is likely to retain its antiseptic function related to the neutrophyl integrin binding. Therapeutic applications could result in this APC mutant which retains antiseptic function without anticoagulant side effects.

BackgroundThe so-called off hour effect—that is, increased mortality for patients admitted outside normal working hours—has never been demonstrated in trauma care. However, most of the studies excluded transferred cases. Because these patients are a special challenge for trauma systems, we hypothesised that their processes of care could be more sensitive to the off hour effect.MethodsThe study design was retrospective, cohort and population based. We compared the mortality of all patients by daytime and night-time admittance to hospitals in an Italian region, with 4.5 million inhabitants, following a major injury in 2011. Logistic regression was used, adjusted for demographics and severity of injury (TMPM-ICD9), and stratified by transfer status.Results1940 major trauma cases were included; 105 were acutely transferred. Night-time admission had a significant pejorative effect on mortality in the adjusted analysis (OR=1.49; 95% CI 1.05 to 2.11). This effect was most evident in transferred cases (OR=3.71; 95% CI 1.11 to 12.43).ConclusionsThe night-time effect in trauma care was demonstrated for the first time and was maximal in transferred cases. This may explain why it was not found in previous studies where these patients were mostly excluded. Also, the use of population based data—whereby patients not accessing trauma centre care and presumably receiving poorer care were included—may have contributed to the findings.

Hip fracture is becoming a major public health concern, with associated mortality and morbidity particularly in the elderly. This study aims to investigate factors (i.e. patient factors and hospital variables) associated with increased risk for delaying surgery after hip fractures, and to assess whether and to what extent timing was associated with mortality risk.All patients aged 65 and over, resident in Emilia Romagna Region (Italy) and admitted to hospital for hip fracture (2009 - 2010) were selected. Data on surgical delay were adjusted using multilevel logistic regression model. A Cox proportional hazard model was fitted to a propensity score matched sample to assess mortality between delayed and early treated patients.Of the 10, 995 patients included (mean age: 83.3 years), 44.9% underwent surgery within 2 days. Significant risk factors for delayed surgery were: gender (OR: 1.16), comorbidity (OR: 1.29), anticoagulant (OR: 7.64), antiplatelet medication (OR: 2.43), type of procedure (OR: 1.37) and day of admission (OR: Thu-Fri: 6.05; Sat-Sun: 1.17). Type of hospital and annual volume of hip fracture surgeries were not sufficient to explain hospital variability. A significant difference in mortality rate between early and delayed surgery emerged six months post surgery.

The “Palazzo della Civiltà Italiana” is a monumental building characterized by a reinforced concrete structure composed of parallel (cast in situ) portal frames and composite (reinforced concrete + hollow bricks floors which spans between adjacent portals: a common construction technique in Italy. The floors being characterised by a large span of about 10.0 meters. The construction took place between 1939 and 1943, most likely according to the Italian building code published in 1939. The authors have coordinated a comprehensive experimental campaign aimed at (a) the identification of the characteristics of the structural materials and members, and (b) the identification of eventual damages. Based upon the experimental results a number of analytical and numerical investigations have been developed in order to assess the structural reliability of the “Palazzo” which up to date still is remains in its “original” configuration, as no substantial intervention of structural retrofit or rehabilitation have been implemented so far. These analysis allowed to identify two major reliability issues: (i) the load bearing capacities of the floors do not allow the intended use, and (ii) the seismic vulnerability of the building does not satisfy the reliability standards required by current codes. On the basis of all data acquired and investigations performed, a simple (non invasive) structural retrofit solution capable of bringing the “Palazzo” to the level of structural safety required by current codes is identified.

RiassuntoGli autori presentano la distribuzione aggiornata di Fritillaria montanaHoppe (Liliaceae) in Toscana, tramite l'analisi di campioni d'erbario, riferimenti bibliografici ed indagini di campo. F. montanarisulta segnalata per otto diverse località, tre nella Toscana meridionale e cinque nella Toscana settentrionale, delle quali una non confermata ed una di nuova segnalazione. Sono stati contati in totale 9273 individui, oltre la metà dei quali concentrati in una singola popolazione (Monte Cetona). In tutte le popolazioni è stata osservata una prevalenza numerica degli stadi giovanili (sempre al di sopra del 70%), rispetto agli adulti immaturi ed agli adulti fioriferi; ciò indica molto probabilmente una elevata mortalità giovanile in questa specie, ma anche popolamenti sostanzialmente all'equilibrio. Il rischio di estinzione in Toscana è prevalentemente dovuto alla possibile perdita o riduzione degli habitat in cui la specie si inserisce. Ciò ha indotto gli autori a considerare F. montanacome una specie Nearly Threatened (NT) a livello regionale, in accordo con i criteri IUCN per l'attribuzione delle categorie per le Liste Rosse.

AbstractThe radially decreasing symmetrization is well known not to increase Dirichlet type integrals of Sobolev functions. In the present paper, the deviation of a function from its symmetral is estimated in terms of the gap between their Dirichlet integrals.

Die chronische Niereninsuffizienz ist mit einer verminderten Produktion des aktiven Metaboliten des Vit D, 1 alpha, 25 Dihydroxy-Vitamin D assoziiert. Dies hat mehrere Konsequenzen, die nicht nur auf das Skelettsystem beschränkt sind. In der Tat besitzt Vit D verschiedene Wirkungen, die in diesem Review diskutiert werden. Die Substitution des Vit D wird sehr früh bei der Behandlung der chronischen Niereninsuffizienz in Betracht gezogen, dennoch herrscht noch Unsicherheit über die Art der Substitution. Die Rolle der Vit D-Analoga wird in diesem Review betont, wobei Calcitriol und Paricalcitol verglichen werden.

We obtain the BLT-set associated with the sporadic semifield flock of the quadratic cone in PG(3,35) as the complete intersection of the Payne–Thas and the Kantor–Knuth ovoids of the parabolic quadric Q(4,35. Also, we give an alternative construction of the Penttila–Williams ovoid of Q(4,35).

We prove the existence of bounded solutions for a class of nonlinear elliptic problems of type −div(a(x,u,Du))=H(x,u,Du)+f u∈W1,p0(Ω)∩L∞(Ω) where 〈a(x,η,ξ)ξ〉≥b(|η|)|ξ|p, bis a continuous monotone decreasing function and |H(x,η,ξ)| ≤ k(η)|ξ|p, kis a continuous monotone increasing function.

We prove the existence of bounded solutions for a class of nonlinear elliptic problems whose model is in the form: − div (a(x,u,Du))=k 1 (|u|)|Du|+k 2 (|u|)f,u∈W 0 (Ω)∩L(Ω), where 〈a(x,η,ξ)ξ〉b(|η|)|ξ| , b is a continuous monotone decreasing function and k 1 and k 2 are continuous monotone increasing functions.

We prove estimates for the gradient of solutions u of the homogeneous Dirichlet problem for an equation in the form A(u)=f, where A(u) is a p-laplacian type operator and f is a summable function. The estimate on |Du| is obtained via an estimate on its rearrangement.

This paper focuses on the development of a linear analytical model (even though servo-hydraulic actuation systems are inherently non-linear, especially for large amplitude simulations — near the performance capacity of the system — linearized models proved experimentally to be quite effective overall in capturing the salient features of shaking table dynamics) of a uni-axial, servo-hydraulic, stroke controlled shaking table system by using jointly structural dynamics and linear control theory. This model incorporates the proportional, integral, derivative, feed-forward, and differential pressure gains of the control system. Furthermore, it accounts for the following physical characteristics of the system: time delay in the servovalve response, compressibility of the actuator fluid, oil leakage through the actuator seals and the dynamic properties of both the actuator reaction mass and test structure or payload. The proposed model, in the form of the total shaking table transfer function (i.e. between commanded and actual table motions), is developed to account for the specific characteristics of the Rice University shaking table. An in-depth sensitivity study is then performed to determine the effects of the table control parameters, payload characteristics, and servovalve time delay upon the total shaking table transfer function. The sensitivity results reveal: (a) a potential strong dynamic interaction between the oil column in the actuator and the payload, and (b) the very important effect of the servovalve time delay upon the total shaking table transfer function. Copyright © 2000 John Wiley & Sons, Ltd.

Wire-and-Arc Additively Manufactured (WAAM) alloys are characterized by specific mechanical properties which can largely differ from the conventionally-manufactured alloys. In detail, the printing process results in a peculiar microstructure, characterized by preferential crystallographic orientation with reference to the printing direction, that leads to an anisotropic mechanical behavior of the printed part. Previous experimental tests on WAAM-produced stainless steel plates showed in particular a strong anisotropic elastic behavior. Based on the above, the present work formulates a specific anisotropic elastic model for a WAAM-processed austenitic stainless steel, considering an orthogonally anisotropic (or orthotropic) constitutive law and a procedure to calibrate the elastic parameters based on the experimental results. In detail, the procedure is applied to calibrate the numerical values of the elastic parameters of a specific WAAM 304L austenitic stainless steel. For this aim, specific investigations on both the mechanical and microstructural features were carried out. Experimental tensile tests were performed on specimens with different orientations with reference to the printing direction. In detail, Young’s modulus and Poisson’s ratios were evaluated for samples oriented along three different orientations with regard to the printing deposition layers: longitudinally (L), transversally (T) and diagonally (D) to them. Digital Image Correlation (DIC) optical measuring system was used to acquire the full strain fields during the test. Microstructural analysis was also carried out to study the inherent microstructure, characterized by a distinctive grain growth direction, and to assess the preferred crystallographic orientations of specimens extracted along the three considered directions. The experimental results are used to calibrate the orthotropic elastic model. From the calibrated model additional material properties in terms of Young’s and shear modulus for any printing direction are derived. The resulting values exhibit very large variations with the printing angle, with ratios between minimum to maximum values around 2 for the Young’s modulus and 3.5 for the shear modulus. This marked orthotropic behavior could open unexplored design possibilities based on deformability issues. Additionally, the calibrated orthotropic model can also be used for future experimental explorations of the mechanical properties of WAAM alloys and for stiffness-based structural design optimizations.

We give some comparison results for solutions of Dirichlet problems of elliptic equations and variational inequalities by means of Schwarz symmetrization.

In questo lavoro dimostriamo due teoremi di esistenza di soluzioni periodiche per due classi di equazioni ellittiche totalmente non lineari.

Moser-type estimates for functions whose gradient is in the Lorentz space L(n, q), 1=q=8, are given. Similar results are obtained for solutions u?Hinf0sup1of Au=(fi)xi, where A is a linear elliptic second order differential operator and |f|?L(n, q), 2=q=8.