Types Of Connections Research Articles

Estimation of the contribution to intraoperative pathogen transmission from bacterial contamination of patient nose, patient groin and axilla, anesthesia practitioners' hands, anesthesia machine, and intravenous lumen

BackgroundEarlier studies showed net cost saving from anesthesia practitioners' use of a bundle of infection prevention products, with feedback on monitored Staphylococcus aureus intraoperative transmission. ESKAPE pathogens also include Enterococcus and gram-negative pathogens: Klebsiella, Acinetobacter, Pseudomonas, and Enterobacter. We evaluated whether bacterial contamination of patient nose, patient groin and axilla, anesthesia practitioners' hands, anesthesia machine, and intravenous lumen all contribute meaningfully to ESKAPE pathogen transmission within anesthesia work areas. MethodsThe retrospective cohort study used bacterial count data from nine hospitals, 43 months, and 448 ESKAPE pathogen transmission events within anesthesia areas of 86 operating rooms. Transmission was measured within and between pairs of successive surgical cases performed in the same operating room on the same day. ResultsThere were 203 transmission events with S. aureus, 72 with Enterococcus, and 173 with gram negatives. ESKAPE pathogens in the nose contributed to transmission for 50% (99% confidence limit ≥45%) of case pairs, on the groin or axilla for 54% (≥49%), on the hands for 53% (≥47%), on the anesthesia machine for 21% (≥17%), and in the intravenous lumen for 24% (≥20%). ESKAPE pathogens in the nose started a transmission pathway for 27% (≥22%) of case pairs, on the groin or axilla for 24% (≥19%), on the hands for 38% (≥33%), on the anesthesia machine for 11% (≥7.6%), and in the intravenous lumen for 8.0% (≥5.3%). All P ≤ 0.0022 compared with 5%. ConclusionsTo prevent intraoperative ESKAPE pathogen transmission, anesthesia practitioners would need to address all five categories of infection control approaches: nasal antisepsis (e.g., povidone-iodine applied the morning of surgery), skin antisepsis (e.g., chlorhexidine wipes), hand antisepsis with dispensers next to the patient, decontamination of the anesthesia machine before and during anesthetics, and disinfecting caps for needleless connectors, disinfecting port protectors, and disinfecting caps for open female Luer type connectors.

Impact of Optical Connectors on QKD Transmission

ABSTRACT This paper describes the effect of different optical connector polishing techniques on the quantum channel of a quantum key distribution (QKD) C l a v i s 3 system. First, the basic differences among these types of connector polishing are briefly described. Second, the paper focuses on the design of a simple optical route to measure the effect of APC/UPC (angled physical contact/ultra physical contact) connectors on the quantum channel functionality, which is attributed to the slightly different characteristics of the two types of connectors. However, both types of connectors are commonly employed in real networks. For this reason, two series of measurements are made, one measurement for APC connectors and one measurement for UPC connectors. In each series, the number of connectors is gradually increased by up to 12 connectors per route for a given type. Finally, the results of the measurements, which mainly comprise changes in the three main parameters, are presented. In particular, the key rate, interferometric visibility and QBER (quantum bit error rate) were monitored.

Bank efficiency in Middle East and North African countries: Does political connection type matter?

This study examines the effects of the political connections of chief executive officers (CEOs) or directors on technical, allocative, and cost bank efficiencies examining a panel of 144 banks operating in 12 Middle Eastern and North African (MENA) countries observed over the 2008–2021 period. Using random effect tobit regressions, we find that the three types of political connections explored (aggregate, CEO, and board of directors) have negative effects on banks’ technical and cost efficiencies. In addition, CEO political connections exhibit superior explanatory power. These findings remain robust when we consider the sample in terms of monarchist and republican countries. Further evidence reveals that the effect of political connections is observed more strongly during the pandemic period (2020–2021) than during the 2008–2009 financial crisis period. Our results indicate that banks in MENA countries must strategically regulate bank political connections during crises and consistently thereafter. Our findings have implications for regulators investors and authorities in MENA countries.

Design of reinforced concrete structures with loop joints of rebar in accordance with State Standard R 70447-2022

Introduction. Currently, loop overlapping joints of reinforcing bars are used in reinforced concrete structures. These types of working rebar connections are most widely used in NPP structures for the construction of slabs and walls made of monolithic reinforced concrete. Loop joints in these structures are used to connect adjacent three-dimensional reinforced blocks that are assembled in advance and installed in the design position before concreting. This type of connection leads to an increase in the manufacturability of construction and installation works, as it significantly reduces labor costs on the construction site when installing reinforcement frames.The relevance of the development of the standard is due to the fact that the current regulatory framework did not contain detailed instructions on the design requirements for such connections. The absence of these provisions led to significant difficulties in the design of such structures, which led to excessive material and time costs.The aim of the work is to improve the system of urban planning activities in terms of clarifying and supplementing existing regulatory documents on the design of reinforced concrete structures.Materials and methods. The development of the standard was carried out taking into account modern requirements, as well as an analysis of the results of recent scientific research. Additionally, the practical domestic experience of using loop joints in the construction of nuclear power facilities was analyzed.Results. The result of the work is the State Standard R 70447-2022 standard, the provisions of which include new calculation methods, as well as clarifications of existing calculation and design methods, and updated requirements. The draft standard passed public discussions, as well as the necessary expertise and was put into effect.Conclusions. The standard State Standard R 70447-2022 "Reinforced concrete structures with loop joints of reinforcement for nuclear power facilities" has been developed, the provisions of which will allow developing reliable structural solutions for such structures, including achieving a certain economic effect. At the same time, certain areas for improving the provisions of this standard are noted.

Design and characterization of subsea pipeline rehabilitation connectors

This paper examined the technology for repairing deep water pipelines and designed a new type of subsea pipeline repair connector for a depth of 1500 m with a diameter of 12 inches. The technical specifications of subsea pipeline repair connectors and the characteristics of deepwater environments were used to propose an overall design plan. Static analysis, elastic mechanics theory, and finite element simulation were used to analyze contact stress distribution on the main rubber sealing ring surface. A mathematical relationship was evident between the axial driving force and positive anchoring pressure. A mechanical model was established for the free and constrained deformation stages of the rubber sealing ring and the relationship between the sealing driving force and contact stress. The structure was optimized using the contact stress distribution law. The anchoring and sealing performance of the designed connector were analyzed and optimized.

Fatigue strength of new explosively welded steel-aluminum transition joint used in ships

The paper presents the results of tension-compression fatigue tests of a new steel-aluminum welding transition joint with a titanium Grade 1 interlayer. The new explosive welded transition joint prototype used as a connector in the shipbuilding industry has been developed by the Explomet company situated in Opole-Poland. The paper discusses the advantages of the use of these types of connectors in comparison to the classical approach of using the bolted joints as connectors between non-weldable materials in ships. We are emphasizing its eco-friendly effect on fuel consumption by lowering the weight of the whole structure. The thickness of the new prototype of the transition joint is lower than the standard thicknesses used by other manufacturers. The multilayer metallic composite was subjected to microstructural analysis. Factors influencing fatigue durability were analyzed and the basic analysis of fatigue cracks observed during tests was presented in form of crack propagation curves. The obtained fatigue results show that in most of the analyzed cases, the crack initiation is spotted in the heat-affected zone. According to the standard procedure of fatigue testing none of the prototype test specimens would fulfill the requirements set in the ABS standard used for the testing. This is crucial information in terms of the modification of the welding technology of the transition joint which has to be adapted. Nevertheless, the presented results show that there is a place for improvement in the used welding technology.

Determination of Harness Production Time and Defective Product Formation Risk Factors with Artificial Neural Network

The aim of this research is to estimate the projected production times of the cable harnesses produced for the tender in a company operating in the aviation and defense industry in our country by artificial neural network. For this, artificial neural network model has been formed for the number of work order, the number of cable harness module, the number of cable harness pin, the number of cable harness label, the number of cable harness back shell, the number of cable harness heat shrink tube, and the number of cable harness terminal variables which may have an effect on the projected production times of cable harnesses for the tender. Multiple linear regression analysis method is used to compare the predictive power of this model and the most appropriate method for estimating the projected production time of cable harnesses for the tender is provided. The aim of the research is to determine the effect of cable harness connector type, cable harness label type and personnel competence level risk factors on the formation of faulty cable harnesses determined during the quality control and electrical testing steps in the production process using logistic regression analysis.

Revolving around political connections: the negative effect of government venture capital backing on IPO valuation

Abstract We examine how government venture capital (GVC)—a specific type of political connection—affected initial public offering (IPO) valuation. Contrary to the well-recognized benefits of political connections in channeling access to financial resources in China, our analysis of 959 IPOs between 2008 and 2014 suggests that GVC backing lowers IPO valuation. This baseline effect is moderated by other sources of political connection (e.g. government ownership, state sector experience of top management team members, private sector partner status, and institutional environments). We argue that it is the negative signaling mechanism revolving around political connections that accounts for this observable pattern. This research enriches the signaling theory by uncovering signal emergence and analyzing the interactions between several signaling sources of political connection. Specifically, it contributes to a better understanding of political connections by specifying an undesirable consequence of state-led financialization, which has timely practical relevance as China’s capital market is steering toward a rule-based system.

Machine learning based dynamic super twisting sliding mode controller for increase speed and accuracy of MPPT using real-time data under PSCs

Photovoltaic (PV) systems are created according to the series, parallel or series-parallel connection type of PV panels. Solar panels that form the PV system can have different irradiance values at different times of the day. This condition, which is called partial shading, causes the current and voltage values produced by the panels to fluctuate. Maximum power point tracking (MPPT) algorithms are used to ensure that PV systems operate at maximum power under all environmental conditions. MPPT algorithms are used to optimize the duty cycle of DC-DC converters in order to transfer maximum power to the load. In this study, a two-stage structure is used for MPPT. In the first stage, a reference voltage value is generated using the gaussian process regression (GPR) machine learning algorithm. In the second stage, the duty cycle of the PWM signal required for MPPT is optimized using the super twisting sliding mode controller (STSMC). The performance of the proposed method for three different scenarios is compared with the cuckoo search algorithm (CSA) from metaheuristic optimization algorithms and the perturb and observe (P&O) algorithm from classical optimization algorithms using real-time data. The software used to analyze and compare the researched methods is MATLAB/Simulink R2021b. The proposed method has performed better compared to both CSA and P&O for four conducted scenarios. Additionally, it was observed that the proposed method leads to less oscillation at the MPP point compared to P&O and CSA.

Biomechanical Analysis of Titanium Dental Implants in the All-on-4 Treatment with Different Implant-Abutment Connections: A Three-Dimensional Finite Element Study.

The type of implant-abutment connection is one of the factors influencing the distribution of occlusal forces. This study aims to investigate the biomechanical performance of the mandibular all-on-4 treatment with different implant-abutment connections. Two connection types with 30° abutments and 18-mm implant fixtures were chosen for the posterior implants of the all-on-4 assembly. For the external hexagon connection (EHC) group, the implants with 4 mm in diameter were used. For the internal hexagon connection (IHC) group, we selected implants with 4.3 mm in diameter. A vertical force of 190 N was applied to the cantilever region. The FEA results indicated that the most stressed region in the two groups was prosthetic screws, followed by multi-unit abutments (MUAs). The lowest values of von Mises stress were both observed on the bone. The peak stress value of the implant screw and implant fixture in the EHC group were 37.75% and 33.03% lower than the IHC group, respectively. For stress distribution patterns, the load force tended to be concentrated at locations where components were interconnected. The EHC and IHC are clinically durable under the tested loading conditions, but the prosthetic screws and MUAs can be the weak point on the posterior implant within the mandibular all-on-four assembly. The peak stress values of implant screw and implant fixture in the EHC groups were lower than the IHC group.

Managing marine resources sustainably – Ecological, societal and governance connectivity, coherence and equivalence in complex marine transboundary regions

This overview proposes a novel typology of characteristics required to ensure that marine assessment and management is connected, coherent and/or equivalent across boundaries, both within or between national and international jurisdictions. This defines the types of connectivity, coherence nature and equivalences with their relevance and examples in a marine transboundary context. It indicates the way of identifying impediments to be addressed to ensure that the management across marine boundaries is sustainable and adequate, and it also gives examples of the way of overcoming those barriers. The typology covers natural environmental, governance (policies, politics, administration and legislation), economic and management regimes. It encompasses sector (e.g. fishing, navigation, etc.) and their activity-, pressures-, effects- and management response-footprints and Maritime Spatial Planning and Marine Protected Area-designation. This links monitoring, assessment and reporting across boundaries and within the physico-chemical and ecological realms and in marine conservation across boundaries. Finally, it shows connectivity, coherence and equivalence should reflect wider societal and cultural aspects as well as governance approaches, principles and outcomes in adjacent countries (States) and regions. These aspects are summarised by analysing the so-called 10-tenets for sustainable and successful marine management. Although this typology is developed largely from a European and North America perspective, it is proposed here for validating with examples in other areas worldwide.

Study of the flexural performance and a novel calculation formula for the degree of composite action for precast concrete sandwich panels

SummaryThis study investigates the flexural performance and degree of composite action (DCA) of precast concrete sandwich panels (PCSPs) with four types of connectors. Five full‐scale specimens were designed, and 4‐point bending tests were performed. The specimens included four PCSPs utilizing glass fiber reinforced polymer (GFRP) truss connectors, steel truss connectors, concrete rib connectors, and GFRP pin connectors, respectively, along with a solid panel (SP). The results indicated that the flexural performance and DCA provided by the four types of connectors followed an ascending order as follows: GFRP pin‐type connectors, GFRP truss connectors, steel truss connectors, and concrete rib‐type connectors. Moreover, the study presented a novel method for calculating DCA, namely, the neutral axis method, which was compared with the displacement and strain methods. The reasonableness and accuracy of the neutral axis method in calculating DCA during the linear elastic stage were verified. Results indicated that the neutral axis method provided more precise and reasonable DCA that closely matched the experimental results compared with the displacement and strain methods. Additionally, the neutral axis method was simpler to calculate DCA and had a broader range of applications. Finally, the study provided recommendations for the optimal application scenarios of each calculation method.

Numerical Study on Seismic Behavior of Demountable Joints Consisting of Reinforced Concrete Columns and Steel Beams

In this study, three new types of demountable connections, consisting of reinforced concrete columns and steel beams, are proposed, and their seismic performance is investigated through the use of cyclic loading tests. The test results reveal that these three demountable RCS joints show good seismic performance, in which the ductility coefficients of specimens RCS-1 and RCS-2 are improved by 69% and 109%, respectively, compared with the reference group of RCS-0 specimens. Various parameters, such as the beam flange thickness, bolt strength, and connecting steel strength, were analyzed using the finite element software ABAQUS 2021 to determine the effect of these parameters on the seismic performance and behavior of the connections. The results also show that the three demountable RCS joints are very sensitive to the variation in beam flange steel thickness, while the connector steel strength and bolt type have very little effect on the joint load-carrying capacity. In addition, different current theoretical approaches for calculating the shear bearing capacity in the panel zone of joints are discussed.

Effects of Recycled Concrete on Structural Behavior of Composite Beams with Y-Rib Shear Connectors

This study inspects the structural behavior of composite steel concrete beams connected together by Y-Rib shear connectors using recycled concrete. The main method involves using stud shear connectors with normal concrete. By comparing the structural performance of Y-Rib shear connectors with conventional stud shear connectors, the study aims to determine the benefit of using this type of connector with recycled concrete. Improved results in terms of maximum load-bearing capacity before failure and maintaining structural integrity until failure would indicate a viable solution to the sliding issue seen in traditional composite beams. Regardless of challenges in acquiring traditional shear connectors, the study also explores an alternative: 20mm diameter reinforcing bars. Although this falls outside the primary research scope, the main focus remains on the behavior of composite beams connected by Y-shaped shear connectors with recycled concrete. The investigation encompasses 18 shear connector types, divided into two groups: 9 models with normal coarse aggregate concrete (35.17 MPa) and 9 models with recycled coarse aggregate concrete (33.48 MPa) to determine the benefit of recycled aggregate concrete usage.

Marine spatial planning for connectivity and conservation through ecological corridors between marine protected areas and other effective area-based conservation measures

Maritime Spatial Planning (MSP) promotes the sustainable human activities development and uses in the marine space, playing a role in their effective management. The enhancement of connectivity is crucial for the conservation of biodiversity and landscape planning. Ecological Corridors (ECs) are an important type of connectivity for biodiversity conservation in fragmented habitats. The EU Biodiversity Strategy 2030 includes ECs into the network of protected areas and allows for the creation of additional protected areas. MSP studies considering ECs remain still lacking, especially for the design of networks between Marine Protected Areas (MPAs) and Other Effective area-based Conservation Measures (OECMs). In this paper, knowledge, and tools for investigating marine ECs were reviewed, with a systematic bibliometric analysis to summarize the current scientific research. Previous studies integrating ecological connectivity into planning for marine conservation have focused on models of larval dispersal, adult movements, and dispersal of single species by using benthic habitat proxies. Few studies were found on ECs in marine environments: in the coral Caribbean reef systems in the Gulf of Mexico; within benthic habitats along the Pacific coast of Canada; between MPAs in British Columbia (Canada); and by analyzing migratory species in the Yangtze estuary (China). Commonly used approaches to project and map ECs in marine environments are least-cost and circuit theories allowing to incorporate movement with cost or resistance to movement, depending on species and preferred habitats. The systematic bibliometric analysis returned 25 studies, most of which were from North America (40%) and European countries (36%) and the largest share of papers (68%) from 2018 to 2022. This review pinpointed the need of integrating different disciplines to investigate connectivity and the need by policymakers and practitioners to recognize the importance of ecological connectivity, even there are significant challenges for integrating connectivity into policies, planning, and conservation.

Seismic Response of Reinforced-Concrete One-Storey Precast Industrial Buildings with Horizontal Cladding Panels

An extensive parametric study of the seismic response of one-storey precast buildings with horizontal cladding panels frequently used in Central Europe was conducted to analyse the panels’ influence on the overall response of buildings and to find out if the panels can be considered non-structural elements when they are attached to the main building with the connections typically used in practice in Central Europe. The studied structural system consisted of reinforced concrete columns and beams connected by dowels. Horizontal cladding panels were attached to columns using one of the most frequently used isostatic fastening systems. The top connections provided out-of-plane stability, and the bottom connections supported the panel in the vertical direction. The parametric study was preceded by extensive experimental research, including cyclic tests on connections and full-scale shaking table tests of whole buildings. The results of experiments were used to reveal the basic response mechanisms of panels and connections and to develop, validate and calibrate numerical models employed in the parametric study presented herein. Fifteen generalised structures with different masses and heights were subjected to 30 accelerograms with two peak ground acceleration (PGA) intensities of 0.3 g and 0.5 g, corresponding to significant damage and near-collapse limit states. The effects of the construction imperfections in connections, the silicon sealant panel-to-panel connections and different types of connections of the bottom panel to the foundation were analysed. The crucial parameter influencing the response was the displacement capacity of the connections, which was considerably affected by the construction imperfections and, consequently, difficult to estimate. It has been observed that in some buildings, particularly in shorter structures with smaller mass, cladding panels can have a somewhat more notable influence on the overall response. However, in general, when the considered types of connections are used, the panels can be considered as non-structural elements, which do not importantly influence the response of the main building. Owing to structural imperfections and relatively short available gaps, the failure of the considered top connections and falling of the panels is very likely in the high seismicity regions. In the most adverse cases, it can occur even in the moderate seismicity regions.

Experimental investigation on the seismic behavior of composite steel plate shear wall restrained by ECC panels

The composite structures using engineered cementitious composites (ECC) and steel are promising to achieve good seismic performance due to their excellent deformability and energy dissipation. This paper proposed a novel composite steel plate shear wall restrained by ECC panels. The shear wall system consists of boundary frame, steel plate and precast ECC panels. The steel plate is sandwiched between two precast ECC panels by bolts. Then, the sandwich panel is bolted to the boundary frame by angle steels. Experimental investigation was conducted on the proposed composite shear walls to evaluate their seismic performance. Five one-story one-span specimens with ECC panels considering the effects of panel-frame connection types, reinforcement ratio in ECC panels and aspect ratio were tested, as well as a control specimen with concrete panels. Test results revealed that compared with ordinary buckling-restrained steel plate shear wall, the proposed composite shear walls displayed sufficient ductility, high initial stiffness and satisfactory energy dissipated capacity. Severe cracking and spalling of concrete panels were detected, while the ECC panels still maintained integrity and had high residual strength in the later stage of loading. ECC panels made a considerable contribution to shear resistance in addition to effectively restraining the buckling of the steel plate. In comparison with the specimen using partial four-side connection, the shear capacity, initial lateral stiffness and accumulated dissipated energy of the specimen using four-side connection were notably enhanced by 103%, 22.8% and 108%, respectively. Moreover, using two-side connection weakened the shear capacity and initial lateral stiffness of the specimen by 29.4% and 29.8%, because it could not exhibit complete shear and tension field actions as the specimen using four-side connection.

The regular edge connectivity of regular networks

Classical connectivity is a vital metric to assess the reliability of interconnection networks, while it has defects in the defective assumption that all neighbours of one node may fail concurrently. To overcome this deficiency, many new generalizations of traditional connectivity, such as g-component (edge) connectivity, restricted (edge) connectivity, g-extra (edge) connectivity and so on, have been suggested. For any positive integer a, the a-regular edge connectivity of a connected graph G is the minimum cardinality of an edge cut, whose deletion disconnects G so that each component is a a-regular graph. In this work, we investigate the a-regular edge connectivity of some regular networks, which provides a novel idea for further exploring the reliability of networks. Finally, simulations are carried out to compare the a-regular connectivity with other types of connectivity in some regular networks. The comparison results imply that the a-regular edge connectivity has its superiority.

Bearing capacity analysis of perfobond rib shear connectors in steel-concrete composite structures

Perfobond rib shear connectors (PBL shear connectors) are a commonly used method for connecting steel beams to concrete slabs. However, the varying factors of material strength, geometric parameters, and testing methods lead to notable differences in theoretical models, thereby requiring further research for accurate prediction of bearing capacity. In this paper, the load transfer process and damage evolution mechanism during loading of PBL shear connectors are reviewed. Twenty-five sets of single-ribbed plate test data, consisting of both conventional type and deep-buried type tests, have been selected for analysis. The effects of concrete strength, hole area, transverse rebar area, and steel plate thickness on the bearing capacity have been quantitatively analyzed using linear regression. The analysis results demonstrate that an increase in concrete strength, hole area, transverse rebar area, and steel plate thickness by one unit results in a corresponding increase in bearing capacity by 1.034%, 0.011%, 0.102%, and 0.214% for the conventional type of PBL shear connectors, respectively. An increase in concrete strength, hole area and transverse rebar area by one unit results in a corresponding increase in bearing capacity by 0.511%, 0.015% and 0.094% for the deep-buried type of PBL shear connectors, respectively. Additionally, taking theoretical analysis into account, a predictive equation for the bearing capacity of both conventional type and deep-buried type specimens is proposed. The accuracy and reliability of the proposed equation are verified through comparison with experimental results.

Contemporary outcomes for functional single ventricle with total anomalous pulmonary venous connection

ObjectiveIn 2004, we reported improved early survival for patients with functional single ventricle anatomy and total anomalous pulmonary venous connection. This study sought to discover if outcomes have been ameliorated in the contemporary era. MethodsThis was a single-center review of patients with single ventricle anatomy and total anomalous pulmonary venous connection who were admitted from 1984 to 2021. The cohort was divided into similarly sized groups by date of admission: Era 1: 1984 to 1992, Era 2: 1993 to 2007, and Era 3: 2008 to 2021. Survival was compared, and Cox proportional hazards models were used to evaluate the likelihood of mortality. ResultsWe included 190 patients with single ventricle anatomy and total anomalous pulmonary venous connection. Unbalanced atrioventricular canal defect (70%) was the most common primary diagnosis. The most common type of total anomalous pulmonary venous connection was supracardiac (49%). Approximately one-third (32%) of patients had pulmonary venous obstruction. There were no significant differences in patient characteristics across eras. Early survival after initial palliative operation improved between Eras 1 and 2, and then remained stable in Era 3. Overall survival improved from Era 1 to Eras 2 and 3 (P < .001), but not between Era 2 and 3. Survival to 10 years by Eras 1 to 3 was 15%, 51%, and 54%, respectively. The anatomic features associated with worse survival were hypoplastic left heart syndrome diagnosis (hazard ratio, 1.60; 1.04-2.57) and pulmonary venous obstruction (hazard ratio, 1.80; 1.24-2.69). ConclusionsOverall survival for patients with single ventricle anatomy and total anomalous pulmonary venous connection has plateaued since the early 2000s. Even in the most recent era, survival to age 10 years remains less than 60%. Risk factors for mortality include the diagnosis of hypoplastic left heart syndrome and pulmonary venous obstruction. Further studies should focus on identification of the pathophysiological factors underlying the increased mortality.