Vibration of open cylindrical shells: A three-dimensional elasticity approach

The three-dimensional elastic analysis of the vibration of open cylindrical shells are presented. Transverse normal stress usually neglected in plate and shell higher-order theories has been considered. The natural frequencies and vibration mode shapes have been obtained via a three-dimensional displacement-based extremum energy principle. Excessive requirements for memory and computational effort have been overcome, without sacrificing numerical accuracy, by (i) decoupling the three-dimensional displacements into the product of a set of beam and shell shape functions; and (ii) classifying the vibration modes. The effects of subtended angle and aspect ratio have been concluded for shells with various boundary conditions. Typical vibration mode shapes demonstrating the dependence of vibration characteristics on boundary constraints are presented. ©1998 Acoustical Society of America.published_or_final_versio

A importância dos valores numa gestão de recursos humanos socialmente responsável - estudo de caso numa empresa seguradora angolana

A análise dos valores e a importância dos mesmos na organização e na gestão é o ponto de partida do tema em abordagem. Pretende-se entender como a observância de valores é determinante na gestão socialmente responsável. Destacaremos o papel dos modelos de gestão de recursos humanos e da cultura da organização, onde são criados e veiculados os valores organizacionais, enfatizando-se a ética e a responsabilidade social. Nesta Dissertação realizou-se um Estudo de Caso numa grande seguradora angolana, onde através da análise documental, da observação directa e de entrevistas semi-estruturadas a informantes-chave foi possível inventariar os valores organizacionais e caracterizar as principais políticas numa perspectiva de gestão de recursos humanos socialmente responsável; ABSTRACT: The analysis of the values and its importance at organization and management is the starting point of the theme approach. The aim is to understand how the observance of values is crucial in the socially responsible management. Highlight the role of models in human resource management and organizational culture, where they are created and conveyed organizational values, emphasizing ethics and social responsibility. In this thesis we performed a case study in a large insurance company of Angola, where through the document analysis, direct observation and semi-structured interviews with key informants was possible to make an inventory of organizational values and characterize the main policies from the perspective of resource management socially responsible human

Insights into biofilm dispersal regulation from the crystal structure of the PAS-GGDEF-EAL region of RbdA from Pseudomonas aeruginosa

© 2018 American Society for Microbiology. RbdA is a positive regulator of biofilm dispersal of Pseudomonas aeruginosa. Its cytoplasmic region (cRbdA) comprises an N-terminal Per-ARNT-Sim (PAS) domain followed by a diguanylate cyclase (GGDEF) domain and an EAL domain, whose phosphodiesterase activity is allosterically stimulated by GTP binding to the GGDEF domain. We report crystal structures of cRbdA and of two binary complexes: one with GTP/Mg 2+ bound to the GGDEF active site and one with the EAL domain bound to the c-di-GMP substrate. These structures unveil a 2-fold symmetric dimer stabilized by a closely packed N-terminal PAS domain and a noncanonical EAL dimer. The autoinhibitory switch is formed by an α-helix (S-helix) immediately N-terminal to the GGDEF domain that interacts with the EAL dimerization helix (α6-E) of the other EAL monomer and maintains the protein in a locked conformation. We propose that local conformational changes in cRbdA upon GTP binding lead to a structure with the PAS domain and S-helix shifted away from the GGDEF-EAL domains, as suggested by small-angle X-ray scattering (SAXS) experiments. Domain reorientation should be facilitated by the presence of an α-helical lever (H-helix) that tethers the GGDEF and EAL regions, allowing the EAL domain to rearrange into an active dimeric conformation

Structural insight into SUMO chain recognition and manipulation by the ubiquitin ligase RNF4

The small ubiquitin-like modifier (SUMO) can form polymeric chains that are important signals in cellular processes such as meiosis, genome maintenance and stress response. The SUMO-targeted ubiquitin ligase RNF4 engages with SUMO chains on linked substrates and catalyses their ubiquitination, which targets substrates for proteasomal degradation. Here we use a segmental labelling approach combined with solution nuclear magnetic resonance (NMR) spectroscopy and biochemical characterization to reveal how RNF4 manipulates the conformation of the SUMO chain, thereby facilitating optimal delivery of the distal SUMO domain for ubiquitin transfer

Out-of-equilibrium physics in driven dissipative coupled resonator arrays

Coupled resonator arrays have been shown to exhibit interesting many- body physics including Mott and Fractional Hall states of photons. One of the main differences between these photonic quantum simulators and their cold atoms coun- terparts is in the dissipative nature of their photonic excitations. The natural equi- librium state is where there are no photons left in the cavity. Pumping the system with external drives is therefore necessary to compensate for the losses and realise non-trivial states. The external driving here can easily be tuned to be incoherent, coherent or fully quantum, opening the road for exploration of many body regimes beyond the reach of other approaches. In this chapter, we review some of the physics arising in driven dissipative coupled resonator arrays including photon fermionisa- tion, crystallisation, as well as photonic quantum Hall physics out of equilibrium. We start by briefly describing possible experimental candidates to realise coupled resonator arrays along with the two theoretical models that capture their physics, the Jaynes-Cummings-Hubbard and Bose-Hubbard Hamiltonians. A brief review of the analytical and sophisticated numerical methods required to tackle these systems is included.Comment: Chapter that appeared in "Quantum Simulations with Photons and Polaritons: Merging Quantum Optics with Condensed Matter Physics" edited by D.G.Angelakis, Quantum Science and Technology Series, Springer 201

A new nail with a locking blade for complex proximal humeral fractures

INTRODUCTION: The objective of this study was to assess the clinical outcome of displaced proximal humerus fracture treated with a new locking blade nail. MATERIALS AND METHODS: This prospective study included a series of 92 patients with acute fracture of the proximal humerus treated in one hospital level I trauma centre with locking blade nail between December 2010 and December 2013. According to the Neer classification, all fractures were two- to four-part fractures. Age adopted Constant score, DASH and visual analogue scores were used as outcome measures. RESULTS: A total of 92 patients were enrolled in the study. However, 29 patients were excluded due to loss to follow-up and death. Ultimately, 63 patients were available for final follow-up and data analysis. The mean duration of follow-up was 22 months (range 16–48 months). On average at 1 year, all fractures had united. The mean weighted Constant score was 84.2 % and the median disabilities of the arm, shoulder and hand (DASH) score was 26, the range of elevation was 115 and range of abduction was 97. The head shaft angle was 130, and pain visual analogue was 1.6. We found that 5 of the 63 patients (8 %) demonstrated complications. Two patients (3 %) displayed secondary displacement and require device removal. Two patients (3 %) had impingement due to prominent metal work, and one patient had a superficial wound infection which was treated with a course of antibiotics. CONCLUSION: Our study shows excellent results with new locking blade nail for displaced proximal humerus fractures. We think the locking blade nail offers stiff triangular fixation of the head fragment and support of the medial calcar region to prevent secondary varus collapse. LEVEL OF EVIDENCE: III

Executive summary of the KDIGO 2021 Guideline for the Management of Glomerular Diseases.

The Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline for the Management of Glomerular Diseases is an update to the KDIGO 2012 guideline. The aim is to assist clinicians caring for individuals with glomerulonephritis (GN), both adults and children. The scope includes various glomerular diseases, including IgA nephropathy and IgA vasculitis, membranous nephropathy, nephrotic syndrome, minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), infection-related GN, antineutrophil cytoplasmic antibody (ANCA) vasculitis, lupus nephritis, and anti-glomerular basement membrane antibody GN. In addition, this guideline will be the first to address the subtype of complement-mediated diseases. Each chapter follows the same format providing guidance related to diagnosis, prognosis, treatment, and special situations. The goal of the guideline is to generate a useful resource for clinicians and patients by providing actionable recommendations based on evidence syntheses, with useful infographics incorporating views from experts in the field. Another aim is to propose research recommendations for areas where there are gaps in knowledge. The guideline targets a broad global audience of clinicians treating GN while being mindful of implications for policy and cost. Development of this guideline update followed an explicit process whereby treatment approaches and guideline recommendations are based on systematic reviews of relevant studies, and appraisal of the quality of the evidence and the strength of recommendations followed the "Grading of Recommendations Assessment, Development and Evaluation" (GRADE) approach. Limitations of the evidence are discussed, with areas of future research also presented

Integrating Extrinsic and Intrinsic Cues into a Minimal Model of Lineage Commitment for Hematopoietic Progenitors

Autoregulation of transcription factors and cross-antagonism between lineage-specific transcription factors are a recurrent theme in cell differentiation. An equally prevalent event that is frequently overlooked in lineage commitment models is the upregulation of lineage-specific receptors, often through lineage-specific transcription factors. Here, we use a minimal model that combines cell-extrinsic and cell-intrinsic elements of regulation in order to understand how both instructive and stochastic events can inform cell commitment decisions in hematopoiesis. Our results suggest that cytokine-mediated positive receptor feedback can induce a “switch-like” response to external stimuli during multilineage differentiation by providing robustness to both bipotent and committed states while protecting progenitors from noise-induced differentiation or decommitment. Our model provides support to both the instructive and stochastic theories of commitment: cell fates are ultimately driven by lineage-specific transcription factors, but cytokine signaling can strongly bias lineage commitment by regulating these inherently noisy cell-fate decisions with complex, pertinent behaviors such as ligand-mediated ultrasensitivity and robust multistability. The simulations further suggest that the kinetics of differentiation to a mature cell state can depend on the starting progenitor state as well as on the route of commitment that is chosen. Lastly, our model shows good agreement with lineage-specific receptor expression kinetics from microarray experiments and provides a computational framework that can integrate both classical and alternative commitment paths in hematopoiesis that have been observed experimentally

High resolution melting analysis for a rapid identification of heterozygous and homozygous sequence changes in the MUTYH gene

Background: MUTYH-associated polyposis (MAP) is an autosomal recessive form of intestinal polyposis predisposing to colorectal carcinoma. High resolution melting analysis (HRMA) is a mutation scanning method that allows detection of heterozygous sequence changes with high sensitivity, whereas homozygosity for a nucleotide change may not lead to significant curve shape or melting temperature changes compared to homozygous wildtype samples. Therefore, HRMA has been mainly applied to the detection of mutations associated with autosomal dominant or X-linked disorders, while applications to autosomal recessive conditions are less common. Methods: MUTYH coding sequence and UTRs were analyzed by both HRMA and sequencing on 88 leukocyte genomic DNA samples. Twenty-six samples were also examined by SSCP. Experiments were performed both with and without mixing the test samples with wild-type DNA. Results: The results show that all MUTYH sequence variations, including G > C and A > T homozygous changes, can be reliably identified by HRMA when a condition of artificial heterozygosity is created by mixing test and reference DNA. HRMA had a sensitivity comparable to sequencing and higher than SSCP. Conclusions: The availability of a rapid and inexpensive method for the identification of MUTYH sequence variants is relevant for the diagnosis of colorectal cancer susceptibility, since the MAP phenotype is highly variable

Gene Expression Studies in Major Depression

The dramatic technical advances in methods to measure gene expression on a genome-wide level thus far have not been paralleled by breakthrough discoveries in psychiatric disorders—including major depression (MD)—using these hypothesis-free approaches. In this review, we first describe the methodologic advances made in gene expression analysis, from quantitative polymerase chain reaction to next-generation sequencing. We then discuss issues in gene expression experiments specific to MD, ranging from the choice of target tissues to the characterization of the case group. We provide a synopsis of the gene expression studies published thus far for MD, with a focus on studies using mRNA microarray methods. Finally, we discuss possible new strategies for the gene expression studies in MD that circumvent some of the addressed issues