Pre-existing Structures Research Articles

The shiny new object: Deconstructing the patient-oriented paradigm in health sciences.

A 'patient-oriented' research paradigm, also known as patient and public engagement, has infiltrated the field of health sciences and continues to spread. At first blush, it is difficult to reprove anything labelled 'patient-oriented'; however, the patient-oriented paradigm may easily become an ideological 'good', leading to unintended consequences that may well prove more detrimental than beneficial. While patient-oriented research has its roots in more radical forms of patient and public engagement, its recent instantiation betrays its roots and forecloses on more radical forms of engagement, such as critical participatory research. The objective of this article is to deconstruct the patient-oriented research narrative and to demonstrate how such a discourse imposes itself as a dominant approach in health sciences. Following Derrida's deconstructive approach, we bring to light the unexamined presuppositions, false pretences, and presumed 'goodness' and 'naturalness' of patient-oriented discourse. By deconstructing the patient-oriented narrative we demonstrate how pre-existing power structures (biomedical, economic, etc.) shape the conduct of the approach and serve to depoliticize the truly participatory aspects of research. Rather than being modelled on the evidence-based movement or seen as its natural 'evolution', patient-oriented research should resist by affirming itself as a radical form that is both participatory and emancipatory.

How subsurface and double-core anticyclones intensify the winter mixed-layer deepening in the Mediterranean Sea

Abstract. The mixed layer is the uppermost layer of the ocean, connecting the atmosphere to the subsurface ocean through atmospheric fluxes. It is subject to pronounced seasonal variations: it deepens in winter due to buoyancy loss and shallows in spring while heat flux increases and restratifies the water column. A mixed-layer depth (MLD) modulation over this seasonal cycle has been observed within mesoscale eddies. Taking advantage of the numerous Argo floats deployed and trapped within large Mediterranean anticyclones over the last decades, we reveal for the first time this modulation at a 10 d temporal scale, free of the smoothing effect of composite approaches. The analysis of 16 continuous MLD time series inside 13 long-lived anticyclones at a fine temporal scale brings to light the importance of the eddy pre-existing vertical structure in setting the MLD modulation by mesoscale eddies. Extreme MLD anomalies of up to 330 m are observed when the winter mixed layer connects with a pre-existing subsurface anticyclonic core, greatly accelerating mixed-layer deepening. The winter MLD sometimes does not achieve such connection but homogenizes another subsurface layer, then forming a multi-core anticyclone with spring restratification. An MLD restratification delay is always observed, reaching more than 2 months in 3 out the 16 MLD time series. The water column starts to restratify outside anticyclones, while the mixed layer keeps deepening and cooling at the eddy core for a longer time. These new elements provide new keys for understanding anticyclone vertical-structure formation and evolution.

Interface engineering of LDH-based material as efficient anti-corrosive system via synergetic performance of host, interlayers, and morphological features of nature-mimic architectures

High-performance hybrid materials with special features are desired to meet the requirements of more complex cutting-edge applications. However, the self-assembly of layered double hydroxides (LDH) with organic frameworks is hampered by a lack of understanding of the formation mechanism and the effects of the self-assembled architecture on anticorrosion activity remain a major challenge. Herein, we put forward how the honeycomb-like network would architecturally upgraded on the pre-existing hierarchical floral structure with Trimesic acid (TMA) compound resulting in a promising layer-by-layer (LBL) material. This nature-inspired network is realized to offer an ideal approach not only endows with excellent properties but also exploits the power of layered coating materials as a bastion in the fields of nanotechnology, without limiting conditions, taking advantage of the synergy beneficial effects of the self-assembled honeycomb-like TMA and the anion-exchange ability of the layered coating material. In this work, a three-dimensional assembly with an architecture closely resembling interconnected micro-petals was successfully deposited on the defective surface obtained via plasma electrolytic oxidation (PEO) of Mg alloy, where TMA compound was used for supramolecular self-assembly. The MgO layer was first formed on AZ31Mg alloy via PEO treatment and the Mg-Al LDH micro-petals were synthesized on the MgO surface in the presence of a chelating agent [diethylenetriaminepentaacetic acid (DTPA)]. In a typical synthesis, TMA compound was used as an appropriate linker for the formation of well-organized multidimensional layered materials taking advantage of the synergy beneficial effects of the self-assembled honeycomb-like TMA and the anion-exchange ability of the Mg-Al LDH coating. The results indicate that Mg alloy coated with the self-assembled TMA@LDH-MgO materials presents excellent anti-corrosion performance as compared to the bare Mg. The use of such system would open a brand-new possibility to correct, in a targeted way, the inevitable defects of the layered coating morphology while retaining its exceptional potential. First-principles calculations, quantitative molecular surface analyses and independent gradient model framework further verify the self-assembly and adsorption behavior of TMA over the Mg-Al LDH layer. The improved performance of the TMA@Mg-Al LDH film is attributed to the synergistic effects of different interactions that occurred around active sites in the hierarchical network.

The Late Devonian contraction along the Precaspian Basin north margin: Transpressional range building in the intracratonic domain

The evolution of intraplate sedimentary basins located in the vicinity of an active convergent plate boundary is often controlled by the collisional dynamics of the adjacent orogen. The transfer of compression from the orogen to the platform's interior results in the formation of complex structural geometry and kinematics that often reactivate older crustal faults, focus far-field stresses and control the evolution of associated sedimentary basins. One place where this localisation can be optimally understood is the Precaspian Basin, situated at the SE periphery of the East European Craton and bordered to the east by the Uralian orogen. The Precaspian Basin and its northern margin experienced long-term extension and subsidence interrupted by several short-lived shortening episodes. To understand the impact and role of pre-existing basement structures on the geometry and kinematics of the subsequent deformation, we analysed subsurface data from the northern margin of the Precaspian Basin by the means of 3D seismic interpretation correlated with wells and structural modelling. The analysis results provide new insights into the kinematic effects of the Late Devonian contraction event. The superposition of stratigraphic units above and below the angular unconformity suggests an intra-Famennian age of the deformation event. Steeply dipping bi-verging reverse fault zones associated with variable amounts of sinistral strike-slip movement component display an arcuate geometry, trending from WSW-ENE to NW-SE. The distribution of deformation indicates that this complex kinematic pattern was driven by a NE-SW oriented contraction and transpression, where faults show the characteristics of a restraining bend area. This area is interpreted as part of a regional transcurrent fault system developed on the northern periphery of the Precaspian Basin. Furthermore, the study results suggest that intralithospheric stress localisation transmitted by the Paleouralian subduction zone resulted in the reactivation of pre-existing basement structures, propagation of faults, and localized short-term exhumation of the Precaspian Basin north margin. Generated by the collision of Magnitogorsk volcanic arc with East European Craton, far-field stress transfer produced a zone of oblique deformation. These data and interpretation demonstrate that the northern margin of the Precaspian Basin is an excellent natural setting to investigate and better understand mechanisms of far-field strain localisation and reactivation of deformational structures in stable platform areas resulting in the intracratonic mountain building process.

Revolutions in Resolution: Cultural Passing through “Cinematic” Video

This article investigates video production in the early digital era in relation to the “cinematic mode,” a practice in which video makers have attempted to emulate the look and feel of analog film with cheaper digital video. As a marker of esteem, professionalism, and legitimacy, the “cinematic look” has served as a qualitative image standard and a visible point of separation that places cameras and their users in hierarchies of cultural importance. Utilizing the video production trade press, I discuss the differences between early digital cameras’ “video look” in relation to the cinematic standard and speak to the stakes of achieving and leveraging the “cinematic look” as a potentially revolutionary act of cultural passing, as its use elevated the status of video practitioners and enabled them to pass cultural gatekeepers, to further cultivate and diversify a culture of low-budget independent cinema and to generate opportunities for personal and company growth so long as they functioned within the preexisting industry power structure.

Peace, violence & social distance: Ethnography of an elite school in India

The article attempts to understand the concept of peace through the prism of social realities. The central argument deconstructs violence and peace as a variable of social distance. Consequently, social interactions become the mechanism of inequalities to underscore how asymmetries of power restructure the social distance. However, interactions are not always actualization of the pre-existing vertical social structures (shaped by power) but how agentic dispositions can counter the course of these interactions and the resultant social distance. The recalibration or maintenance of this distance through the agency is then understood in light of peace or violence framework. The course of analysis builds upon “structural violence” and “Convivencia” as a measure of social distance in relationships. Highlighting the Foucauldian notion of “governmentality”, the article concludes social distance enabled “informal” pedagogy as a more intrusive and more insidious form of pedagogy than the disciplinary one because it attends to the affective aspects of learning. The analysis is based upon ethnographic fieldwork conducted at an elite international residential school in India. As this builds an evaluative space of “peace thinking”, it provides for complexities of peace research.

Premorbid Personality Traits as Risk Factors for Behavioral Addictions: A Systematic Review of a Vulnerability Hypothesis.

The debate on personality structure and behavioral addictions is an outstanding issue. According to some authors, behavioral addictions could arise from a premorbid personality, while for others, it could result from a pathological use of technological tools. The current study aims to investigate whether, in the latest literature, personality traits have been identified as predictors of behavioral addictions. A literature search was conducted under the PRISMA methodology, considering the most relevant studies of the five-factor model from the past 10 years. Overall, most studies on addiction, personality traits, and personality genetics proved that behavioral addiction may be an epiphenomenon of a pre-existing personality structure, and that it more easily occurs in vulnerable subjects with emotional instability, negative affects, and unsatisfactory relationships with themselves, others, and events. Such neurotic personality structure was common to any addictive behavior, and was the main risk factor for both substance and behavioral addictions. Therefore, in clinical and educational contexts, it becomes crucial to primarily focus on the vulnerability factors, at-risk personality traits, and protective and moderating traits such as extroversion, agreeableness, conscientiousness, and openness to experience; meanwhile, treatment of behavioral addictions is frequently focused on overt pathological behaviors.

Origin of the propatagium in non-avian dinosaurs

Avian wings as organs for aerial locomotion are furnished with a highly specialized musculoskeletal system compared with the forelimbs of other tetrapod vertebrates. Among the specializations, the propatagium, which accompanies a skeletal muscle spanning between the shoulder and wrist on the leading edge of the wing, represents an evolutionary novelty established at a certain point in the lineage toward crown birds. However, because of the rarity of soft-tissue preservation in the fossil record, the evolutionary origin of the avian propatagium has remained elusive. Here we focus on articulated skeletons in the fossil record to show that angles of elbow joints in fossils are indicators of the propatagium in extant lineages of diapsids (crown birds and non-dinosaurian diapsids), and then use this relationship to narrow down the phylogenetic position acquiring the propatagium to the common ancestor of maniraptorans. Our analyses support the hypothesis that the preserved propatagium-like soft tissues in non-avian theropod dinosaurs (oviraptorosaurian Caudipteryx and dromaeosaurian Microraptor) are homologous with the avian propatagium, and indicate that all maniraptoran dinosaurs likely possessed the propatagium even before the origin of flight. On the other hand, the preserved angles of wrist joints in non-avian theropods are significantly greater than those in birds, suggesting that the avian interlocking wing-folding mechanism involving the ulna and radius had not fully evolved in non-avian theropods. Our study underscores that the avian wing was acquired through modifications of preexisting structures including the feather and propatagium.

Compositional diversity in the Mare Marginis and Mare Smythii: An insight into the volcanism in the region

The Marginis-Smythii region of the eastern limb of the Moon is a unique geological setting with the presence of equally widespread volcanism both inside and outside of an impact basin. Mare Marginis (13.3°N, 86.1°E) is a large mare deposit lying north of the pre-Nectarian Smythii Basin (13.3°N, 86.1°E). The basalts from Mare Marginis are deposited in a topographically low area outside an impact basin, i.e. the Smythii Basin. The Marginis-Smythii region is important to understand the geological controls on basalt emplacement on the Moon. In this study, we carry out a detailed investigation of the Mare Marginis and Mare Smythii basalts using the Moon Mineralogy Mapper (M3) data to understand the compositional diversity of the basalt deposits. Our study reveals that the basalts in the Mare Marginis can be divided into two distinct units: i) the central and eastern Marginis basalts that are spectrally similar to the Mare Smythii basalts, and ii) the western lacus, described as Margins west which is a small basalt deposit in the western fringes of Mare Marginis having a spectral composition different from the rest of Mare Marginis and Mare Smythii. We report that the volcanism in this compositionally distinct unit of Marginis west occurred up to ∼3.1 Ga when volcanism was still active in the Smythii Basin. We found that the volcanism in Mare Marginis was influenced by both; Crisium and Smythii Basins implying that the pre-existing structures in the lunar crust generated by large-scale impacts play an important role in the volcanism on the Moon.

Effect of Pre-Existing Underground Structures on Groundwater Flow and Strata Movement Induced by Dewatering and Excavation

Based on an actual excavation of a metro station in Tianjin, China, a fluid–solid coupling numerical model was developed to study the characteristics of groundwater flow and strata movement induced by dewatering and excavation considering the barrier effect of pre-existing adjacent underground structures. Two parameters were selected for the model: the distance between the excavation and the existing underground structure (D), and the buried depth of the adjacent structure (H). By comparing the distribution of groundwater drawdown and deformation modes of the retaining structure and the strata under different working conditions, the influence mechanism of adjacent structures on the movement of groundwater and strata was revealed. The results show that the pile foundations have different effects on the groundwater flow and excavation deformation. Generally, the maximum groundwater drawdown could be enlarged by considering the adjacent underground structure, while the retaining structure deflection would be reduced and the ground settlement could be either enlarged or reduced. Additionally, as D decreases and H increases, a much greater groundwater drawdown and a much smaller retaining structure deflection would appear, which together affect the ground behavior. On the one hand, greater groundwater drawdown would lead to greater ground settlement by soil consolidation, while on the other hand, a smaller retaining structure deflection would lead to smaller ground settlement. Thus, a complex development of ground settlement would appear, and a specific analysis should be performed to assess this in practice, based on a specific H and D.

Mid-crustal reactivation processes linked to frictional melting and deep void development during seismogenic slip: examples from the Lewisian Complex, NW Scotland

Exhumed examples of ancient fault voids formed during seismic slip at depths >10 km are well preserved in the Assynt Terrane of the Lewisian Complex, NW Scotland. They are interpreted to have formed during regional Mesoproterozoic ( c. 1.55 Ga; ‘Assyntian’) strike-slip faulting. Deformation is characterized by sinistral reactivation of pre-existing NW–SE-trending features including intrusive contacts of ( c. 2.4 Ga) mafic dykes and Paleoproterozoic ductile shear zone fabrics ( c. 1.75 Ga). Reactivation occurred at palaeodepths of 10–15 km, where frictional–viscous deformation synchronous with co-seismic frictional melting led to cycles of millimetre- to decimetre-scale cavity dilation and collapse. Although individual melt-generating slip surfaces may have become rapidly welded, faulting was able to repeatedly localize along adjacent pre-existing planar anisotropies favourably oriented for slip, leading to the creation of a mesh of foliation-parallel melt generation surfaces linked by foliation-perpendicular dilational voids. The latter features are filled by chaotic clast-supported wall rock collapse breccias, localized injected frictional melts and hydrothermal mineralization. The fills act as natural props, holding cavities open and preserving them as long-term, pipe-like fluid flow conduits. These exhumed features are likely to be typical of multi-rupture seismogenic fault systems formed by direct reactivation of pre-existing basement structures.

Tectonic geomorphology of the Ottawa-Bonnechere Graben, Eastern Canada: implications for regional uplift and intraplate seismicity

In intraplate areas where regional tectonic strain is accommodated by the reactivation of pre-existing structures, the level of seismic hazard associated with faults may be underestimated due to the poor surface expression of faults, scattered earthquake distribution, and long earthquake recurrence intervals. The cause(s) of seismicity in eastern Canada remains unresolved. This is partially because surface expressions of faults have been eroded during glacial and deglacial periods and in the Ottawa-Bonnechere Graben (OBG) are undetectable until a seismic event. Morphotectonic analysis has been widely applied to assess relative tectonic activity in various geological settings. To establish whether active uplift is occurring and to investigate the spatial distribution of relative uplift rates, 131 bedrock drainage basins in OBG were analysed. The aim of this was to (1) test the applicability of geomorphic indices for quantifying active deformation, (2) quantify the spatiotemporal distribution of relative uplift rates, and (3) explore the implications for faulting mechanisms, deformation styles, and ultimately regional seismic hazard. We measured valley floor width-to-height ratio ( Vf), basin elongation ratio ( Re), basin hypsometric integral, and normalized channel steepness index ( ksn). The results show that high relative uplift rates exist in all the six bedrock escarpment sections investigated, suggesting that they are presumably related with regional broad wavelength uplift (epeirogeny) caused by a complex interaction between far-field tectonic stress and glacial isostatic adjustment (GIA). Our analysis showed that Vf, Re, and ksn reveals no considerable spatial differences in high relative uplift rates, consistent with the Canadian Base Network GPS uplift rates. Highlights Geomorphic indices are applied in a low relief and low-medium seismicity area. Geomorphic indices reveal a broad wavelength regional uplift and show relative tectonic activity in the OBG. Relatively high geomorphic indices values provide longer term deformation history compared to global positioning system (GPS) records. Landscape formation and river incision is driven by a complex interaction between GIA and far-field tectonic stresses. Relative uplift rate results show similar patterns to published GPS uplift rates. Possible link between relative tectonic activity and current seismicity.

Transverse tectonics control on the Late Quaternary development of the Central Main Ethiopian Rift

Extension of continental plates should typically result in the development of normal faults perpendicular or sub-perpendicular to the plate motion vector. However, several factors such as linkage of rift segments and the presence of pre-existing fabrics may result in the development of complex fault systems, with structures oblique or even sub-parallel to the extension vector. This paper is focused on the extension-related deformation of the central sector of the Main Ethiopian Rift (MER) and shows the presence of a transverse structure (ie., sub-parallel to extension) in the central MER that played an important role during the Late Quaternary, influencing the hydrographic evolution in this area. Structural data evidence its tectonic activity and the analysis of distribution of magmatic centres and other volcanic features shows that interaction between transverse structures and the faults delimiting the rift may favour formation of volcanic centres. The orientation of this transverse structure, sub-parallel to extension, is interpreted as being caused by the linkage of major segments of the MER that likely exploited pre-existing structures, as widely documented in the MER.

Does integument arise de novo or from pre-existing structures? ── Insights from the key regulatory genes controlling integument development.

The origin of seeds is one of the key innovations in land plant evolution. Ovules are the developmental precursors of seeds. The integument is the envelope structure surrounding the nucellus within the ovule and developing into the seed coat when ovules mature upon fertilization. The question of whether the integument arise de novo or evolve from elaboration of pre-existing structures has caused much debate. By exploring the origin and evolution of the key regulatory genes controlling integument development and their functions during both individual and historical developmental processes, we showed the widespread presence of the homologs of ANT, CUC, BEL1, SPL, C3HDZ, INO, ATS, and ETT in seedless plant genomes. All of these genes have undergone duplication-divergence events in their evolutionary history, with most of the descendant paralogous suffering motif gain and/or loss in the coding regions. Expression and functional characterization have shown that these genes are key components of the genetic program that patterns leaf-like lateral organs. Serial homology can thus be postulated between integuments and other lateral organs in terms of the shared master regulatory genes. Given that the genetic program patterning leaf-like lateral organs formed in seedless plants, and was reused during seed origin, the integument is unlikely to arise de novo but evolved from the stem segment-specific modification of pre-existing serially homologous structures. The master 'switches' trigging the modification to specify the integument identity remain unclear. We propose a successive transformation model of integument origin.

Establishment of an interdisciplinary vascular anomalies program in Tanzania, East Africa.

The aim of this project is the sustainable implementation of a vascular anomalies (VA) program in Tanzania. In 2021 the first interdisciplinary VA program was initiated at Muhimbili National Hospital (MNH), Dar Es Salaam, Tanzania in a stepwise approach. During the planning phase the clinical need for minimally-invasive therapies of VAs and the preexisting structures were assessed by the local Interventional Radiology (IR) team at MNH. During the initiation phase, an IR team from two German VA centers joined the interdisciplinary team at MNH for clinical workup, image-guided procedures and follow-up. VA patients were recruited from existing patient records or seen at clinics as de novo presentations following nationwide advertisement. In the post-processing phase joined online conferences for follow-up and support in management of new patients were established. Further follow-up was supported by attending providers from other established VA centers, traveling to bolster the primary operators of MNH. The first interdisciplinary VA program was successfully launched in Tanzania. Minimally-invasive treatments were successfully trained, by performing ultrasound-guided sclerotherapy with polidocanol and bleomycin in twelve patients with slow-flow malformations, one endovascular embolization of a high-flow malformation, and medical treatment of an aggressive infantile hemangioma. Regular online follow-up presentations have been initiated. Follow-up evaluation and required treatment was sustained when appropriate. The presented "hands-on" training set the ground for the first interdisciplinary VA program in Tanzania. This framework is expected to establish comprehensive and sustainable care of patients with VAs in East Africa and can serve as a blueprint for other sites.

Critical reflections of postgraduate researchers on a collaborative interdisciplinary research project

By employing a retrospective collaborative autoethnographic approach, this work aims to better understand how an interdisciplinary context shaped the authors’ experiences of British academia during their Ph.D research. The authors bring together their individual observations and experiences to collectively interrogate and critically reflect on their position as postgraduate researchers (PGRs) on a collaborative interdisciplinary research project. These reflections are taken as a lens through which to interrogate the contemporary British university. Pre-existing tensions within the academy are characterised as ‘asymmetries’ along dimensions of risk, disciplinary hierarchy, and knowledge. It is argued that the authors’ experience of uncertainty and precarity as junior academics stems principally from pre-existing structures within British academia, rather than the interdisciplinary environment in which they were immersed. By emphasising the role of the successfully trained doctoral candidate as an outcome itself, it is argued that indicators of success can be reframed, shifting the power asymmetry to place greater value on PGRs within the neoliberal academy. Highlighting the ambiguity of their convergent and divergent personal experiences, the authors suggest there is a need for a greater focus on the contested role of the PGR within the contemporary university system.

“I am Sámi, but I am not a Sámi”

This article gives voice to coastal Sámi students and explores their negotiations over being Sámi or Norwegian within the Norwegian education system. Through interviews, students share insights on the extent to which education focuses on Sámi issues and reflect upon their identity. The article explores how youths negotiate personal identity within pre-existing structures by employing Archer’s theory on structure and agency as a backdrop. The changing phases in how ‘western’ societies view indigenous practices and knowledges are applied together with (de)colonial perspectives to understand (colonial) structures. Some key findings are that the coastal Sámi students’ identity negotiations are complex, as official discourses seem to restrict them from identifying as ‘real’ Sámi, and that the local Sámi is within a discursive void due to unintended consequences resulting from the unification in the centralised education system. In focusing on students and using the educational system as a backdrop, this article seeks to deepen the understanding of how society and the educational system in particular condition students’ notions of what it entails to be Sámi and how students negotiate their identity.

Groundwater control for construction projects in chalk

Abstract Construction excavations and tunnels in chalk can encounter groundwater challenges, including high water flow rates, instability of excavations in weathered chalk and basal instability in overlying aquitards caused by high groundwater pressures in deeper chalk aquifers. In hydrogeological settings where the chalk has been exposed to periglacial weathering during the Quaternary Period the upper zones may be degraded to structureless chalk which can potentially be of very low hydraulic conductivity (putty chalk) or very high hydraulic conductivity (chalk bearings). In deeper, structured chalk groundwater flow tends to be concentrated along fissures associated with pre-existing geological structures such as bedding planes, flint beds or faults. A range of groundwater control strategies can be deployed, including open pumping, pre-drainage pumping, shallow and deep cut-off walls, ground treatment and, for tunnels and shafts, application of fluid counter pressures to exclude groundwater. The strategy appropriate to a given site must be selected based on a thorough understanding of the hydrogeological setting and chalk weathering profile. This requires a ground investigation of appropriate scope, using suitable techniques to characterize the chalk. Borehole geophysics can play a key role in identifying discrete zones of inflow.

Leveling the Battlefield: Development of a Pre-Deployment Vascular Access Curriculum for the Nonsurgical Provider.

Timely vascular access is critical, as hemorrhage is the number one cause of death on the battlefield. Anecdotal evidence in the Military Health System identified an operationally relevant procedural skills gap in vascular access, and data exist in civilian literature showing high rates of iatrogenic injuries when lack of robust procedural opportunity exists. Multiple pre-deployment training courses are available for surgical providers, but no comprehensive pre-deployment vascular access training exists for non-surgical providers. This mixed-method review aimed to find relevant, operationally focused, vascular access training publications. A literature review was done to identify both relevant military clinical practice guidelines (CPGs) and full text articles. Reviewers also investigated available pre-deployment trainings for both surgeons and non-surgeons in which course administrators were contacted and details regarding the courses were described. We identified seven full-text articles and four CPGs. Two existing surgical training programs and Army, Navy, and Air Force pre-deployment training standards for non-surgeons were evaluated. A cost-effective and accessible pre-deployment curriculum utilizing reviewed literature in a "learn, do, perfect" structure is suggested, building on pre-existing structures while incorporating remotely accessible didactics, hands-on practice with portable simulation models, and live-feedback training.

Static reinforcement and vibration reduction of structures using topology optimization

This paper presents a topology optimization formulation based on the Solid Isotropic Material with Penalization (SIMP) method and solved by the Modified Optimality Criteria (MOC) algorithm. It addresses mechanical design problems such as structural reinforcement adding elastic material or vibration reduction using viscoelastic layers. The aim is thus to attach on a pre-existing given structure a design domain in order to improve the behavior of this elastic structure, according to an objective function. This can be useful when one wants to use, for example, additive manufacturing to reinforce a pre-existing structure or to maximize structural damping. Two objective functions are tested in both linear statics and dynamics: a compliance based objective function and a displacement based one. In the dynamic case, written in the frequency domain, the two proposed objective functions include the viscoelastic material model (a Zener fractional derivative one) used to fill the design domain. The displacement criteria is developed using a general formula able to take into account as many degree of freedom as necessary. Finally, some applications based on beams and CubeSat-like structures are shown in this article. The proposed examples show that in both statics and dynamics, the optimization of a restrained design domain attached to an existing structure can improve its behavior: stiffness improvement or vibration reduction.