Pre-existing Weaknesses Research Articles

Perceived Impact of Coronavirus Disease 2019 on Surgical Training: A Brazilian Survey

IntroductionRecent studies revealed that coronavirus disease 2019 (COVID-19) negatively impacted residency programs worldwide, particularly procedure-based programs. However, most studies are from high-income countries, with scarce data from low- and middle-income countries. Pandemic effects on surgical training were likely worse in strictly apprenticeship models relying heavily on surgical volume as opposed to competency-based programs. Notably, training programs in Brazil and other low- and middle-income countries follow these strict apprenticeship style frameworks. In this study, we aimed to evaluate the trainees' perceptions of the impact of COVID-19 on their Brazilian surgical programs. MethodsA cross-sectional study was performed using an anonymous survey in Portuguese, distributed via social media platforms to surgical residents enrolled in Brazilian surgery programs. Data collection took place from August 2021 to May 2022. The survey contained 30 questions on the perception of the impact of COVID-19 on surgical training. ResultsOne-hundred sixty-two residents from 17 different surgical specialties and all five regions of Brazil responded to the survey. Of 162 residents, 145 (89%) believed the pandemic negatively impacted their surgical training. Furthermore, of 162 residents, 153 (94%) reported that elective surgical volume decreased during the pandemic and 91 (56%) were redeployed to assist with COVID-19 management. As a result, 102 of 162 (63%) residents believed their surgical skills were negatively impacted by COVID-19. Yet, 95 of 162 (59%) residents reported their residency programs did not offer resources to mitigate the pandemic's impact on training. Of 162 residents, 57 (35%) reported they did not feel on track for graduation, with no statistical difference between responses by year of residency (P = 0.083). Additionally, 124 of 162 (77%) residents reported that the pandemic negatively affected their mental health, most commonly related to stress at work, stress about transmitting COVID-19, and loss in surgical training. ConclusionsMost of the surveyed Brazilian surgical residents felt the COVID-19 pandemic negatively impacted their training. This leads to believe that the detrimental impacts of the pandemic exposed preexisting weaknesses in the Brazilian surgical training model's dependence on a strict apprenticeship model. Our findings suggest a crucial need to redesign surgical education programs to make residency programs more prepared for changes in surgical volume, evolve the apprenticeship model to competency-based approaches, and unify surgical training standards in low- and middle-income countries.

Implementation of policy and management interventions to improve health and care workforce capacity to address the COVID-19 pandemic response: a systematic review

BackgroundThe COVID-19 pandemic highlighted pre-existing weaknesses in health and care systems and services and shortages of health and care workers (HCWs). As a result, policymakers needed to adopt measures to improve the health and care workforce (HCWF) capacity. This review aims to identify countries’ range of policies and management interventions implemented to improve HCWs’ capacity to address the COVID-19 pandemic response, synthesize their evidence on effectiveness, and identify gaps in the evidence.MethodsThe literature was searched in PubMed, Embase, Scopus, LILACS–BVS, WHO’s COVID-19 Research Database and the ILO, OECD and HSRM websites for literature and documents published between January 2020 and March 2022. Eligibility criteria were HCWs as participants and policy and management interventions aiming to improve HCWF capacity to address the COVID-19 pandemic response. Risk of bias was assessed with Joanna Briggs Institute (JBI) Critical Appraisal Tools (CAT) and certainty of the evidence in presented outcomes with GRADE.ResultsThe searches retrieved 3378 documents. A total of 69 were included, but only 8 presented outcomes of interventions implemented. Most of the selected documents described at least one intervention implemented by countries at the organizational environment level to increase the flexibility and capacity of the HCWF to respond to the pandemic, followed by interventions to attract and retain HCWs in safe and decent working environments. There was a lack of studies addressing social protection, human resources for health information systems, and regarding the role of community health workers and other community-based providers. Regarding the risk of bias, most of documents were rated as medium or high quality (JBI’s CAT), while the evidence presented for the outcomes of interventions was classified as mostly low-certainty evidence (GRADE).ConclusionsCountries have implemented various interventions, some innovative, in response to the pandemic, and others had their processes started earlier and accelerated by the pandemic. The evidence regarding the impact and efficacy of the strategies used by countries during the pandemic still requires further research.

COVID-19 Pandemic Lessons for Creating Effective Mental Health Safety Nets in Lower Middle-Income Countries.

The coronavirus disease 2019 (COVID-19) pandemic has posed unprecedented challenges to mental health globally, particularly in low- and middle-income countries (LMICs) such as Pakistan. This narrative review aims to synthesize the literature on the impact of the pandemic on mental health in LMICs, the challenges and opportunities for mental health system reform, and the role of safety nets in promoting mental health.A comprehensive search was conducted in several electronic databases, resulting in 35 articles being included for review. Data were extracted and analyzed to identify key themes and trends.The COVID-19 pandemic has led to a significant increase in the prevalence of mental health problems in LMICs, particularly anxiety and depression. This burden is disproportionately borne by vulnerable populations, including women, front-line workers, and those living in poverty. The pandemic has highlighted pre-existing weaknesses in mental health systems in LMICs, including inadequate funding, lack of trained mental health professionals, and stigmatization of mental illness. However, it has also presented opportunities for reform, such as increased awareness and political will, and the use of technology to expand access to mental health services. Building effective safety nets, including social protection programs and community-based interventions, can promote mental health and address social determinants of mental illness.The COVID-19 pandemic has underscored the urgent need for mental health system reform and the development of effective safety nets in LMICs. Policymakers should prioritize investment in mental health and address the social determinants of mental illness to build more resilient societies.

Multiscale evidence for weathering and the preservation of carbonaceous material in an Antarctic micrometeorite

Micrometeorites (MMs) recovered from the Earth’s surface may have undergone significant changes prior to their collection, including weathering while residing in the terrestrial environment. These alteration processes, such as the precipitation of hydrous phases, may overprint both primary and atmospheric entry features, obscuring pre-existing material properties. In addition, weathering exerts a prominent control on the geochemical interactions, such as species mobility, between extraterrestrial material and the terrestrial environment, particularly in Antarctica. In this study, we have characterised the textural and compositional consequences of weathering on an unmelted, fine-grained, Antarctic MM, which includes the mapping of nanometre-scale features using atom probe tomography. In particular, we investigate geochemical behaviour across textural boundaries in the MM and observe nanoscale elemental heterogeneity within complex alteration assemblages. In one sample region, a compositional boundary is highlighted by distinct elemental differences, consistent with a weathering encrustation of mixed mineralogies, while analyses in other targeted regions show evidence for nanoscale elemental networks, as well as a grain boundary adjacent to a carbon-rich region. We discuss our findings in the context of terrestrial weathering as a dominant cause for the nanoscale features observed. Weathering processes responsible for these features include the leaching of extraterrestrial material, precipitation of secondary alteration products with associated layering, and the influence of mechanical stress on pre-existing weaknesses. From these results, we derive a weathering sequence to explain the formation of the alteration product assemblage and highlight the controls on MM geochemistry in the terrestrial environment. Our observations show that nanoscale carbonaceous material may be preserved in oxy-hydroxides under icy conditions, which can also act as tracers for local environmental changes.

Comparing intrarift and border fault structure in the Malawi Rift: Implications for normal fault growth

Early stages of normal fault growth are seldom described using field observations of active normal faults. Here we first estimate the displacements of active border and intrarift faults in the Zomba Graben in the low extension (< 10 %) Malawi Rift, and then quantify micro-to macroscale fault damage and mineralisation associated with their surface exposures. The 22 km long Mlunguzi and 39 km long Chingale Step intrarift faults have fault zones 4–52 m wide. In contrast, we estimate the fault zone of the 51 km long Zomba border fault is 32–118 m wide. Calcite and clay alteration is limited to the fault damage zones and fault cores, and the extent and intensity of fault damage and mineral alteration is greater on the Zomba border fault compared to the intrarift faults. Relative to global compilations, normal faults in the Zomba Graben have lengthened quickly while developing narrow fault zones, given their displacement. The minor damage on these long, low-displacement normal faults may reflect the influence of lithology, negligible fault healing, and/or activation of pre-existing weaknesses.

Effects of water on mechanical behavior and acoustic emission characteristics of coal in Brazilian tests

An in-depth understanding of how water affects mechanical behavior of coal and fracture failure modes is important for evaluating the stability of underground engineering. In this paper, Brazilian splitting tests are carried out on coal samples with different moisture contents (0%, 1.10%, 2.20%, 3.29% and 4.41%), and acoustic emission (AE) signals are collected simultaneously. The fractal dimension of splitting surfaces is calculated by the cubic covering method to quantitatively describe characteristics of specimens. Combined with two microscopic imaging technologies, i.e. computed tomography (CT) technology and scanning electron microscopy (SEM), the mechanism of crack propagation and strength degradation in coal samples under the effect of water is discussed. Experimental results present that moisture contents change the mechanical strength, AE signals and failure mode of coal samples. As moisture contents increase, the tensile strength of coal samples reduces exponentially, the plastic behavior increases, while the wave velocity increases logarithmically. In the perspective of AE signals, the maximum R value (ratio of cumulative AE hits to cumulative AE energy) increases with the increase of moisture contents, indicating that specimens under higher moisture content conditions can induce more low-energy events, and more complicated crack network. After the splitting failure in coal samples, the fractal dimension of splitting surfaces increases logarithmically with the growth of moisture contents. Based on the macroscopic and mesoscopic characterization results such as AE signals, CT and SEM, it is considered that the existence of water reduces the strength of pre-existing weaknesses (beddings and cleats) in coal samples. As a result, the splitting surface develops along pre-existing weaknesses, which increases the fractal dimension of splitting surfaces and reduces the intensity of AE signals.

Numerical simulation of hydraulic fracturing with consideration of the pore pressure distribution based on the unified pipe-interface element model

Understanding hydraulic fracture propagation behaviours is vital for optimizing fracturing design in oil and gas production. It has been observed that the stress and pore pressure distribution are much more complex during fracturing treatment as a result of long-term fluid injection and production in the reservoir. When rock is subjected to internal hydraulic pressure and external mechanical loading, the closing, opening, or other interactions of pre-existing weaknesses or induced new fractures will be altered. In this paper, a number of hydraulic simulation scenarios are performed to investigate the effect of pore pressure distribution on fracture initiation and propagation using the unified pipe-interface element method (UP-IEM). The proposed method for predicting the hydraulic fracture path in the permeable porous medium with non-uniform pore pressure field is validated with experimental results. Considering the arrangement of well patterns and natural fractures in the rock, the problems of hydraulic fracture propagation behaviours with wellbore interaction and pore pressure induced natural fracture activation are simulated. The influence of pore pressure saturation and the injection sequence of wellbores on hydraulic fracturing are researched. A sensitivity analysis is carried out to investigate the parameter effects on pre-existing fracture tortuosity, opening width and breakdown pressure under pore pressure. These numerical examples provide guidance to engineers to estimate the probability of danger or possibilities to improve the injection and production of wells.

Hurricane María and Public Health in Puerto Rico: Lessons Learned to Increase Resiliency and Prepare for Future Disasters.

Background:On September 20, 2017, Hurricane Maria, a devastating Category 5 storm struck the Caribbean Island of Puerto Rico and officially took the lives of 2 975 people although the Harvard University survey in 2018 placed that number much higher at 4 645 [12]. The island’s infrastructure was devastated. Eight months later in May 2020, many vital services including telecommunications, utilities, and health care systems had not yet been repaired.Objectives:To (1) review the immediate public health problems and the longer-term repercussions of Hurricane Maria; (2) identify pre-existing infrastructural deficiencies, health disparities, and problems in governance that may have increased vulnerability and delayed recovery; and (3) offer proposals for preventive measures to increase resiliency and adequately prepare Puerto Rico for future disasters.Methods:Data from the CDC and the Puerto Rico’s Health Department were collected and analyzed. Government publications, news articles, scholarly journal entries and previous research were examined. Interviews were conducted with local citizens and public health professionals. The author’s personal experience is referenced.Findings:The Puerto Rican Electric Power Authority (PREPA) and the Puerto Rico Aqueduct and Sewer Authority (PRASA) both had severely weakened infrastructures before the hurricane as a result of a massive financial crisis that had begun in 2006. These pre-existing weaknesses increased vulnerability and made reconstruction more challenging. Approximately 95% of the cell towers in Puerto Rico sustained significant damage during the hurricane and resulted in almost total loss of cell phone communication [3]. Subpar management of relief efforts by both federal agencies and the local government further hindered recovery, resulting in mass emigration of Puerto Ricans. The public health problems of Hurricane Maria continue to plague Puerto Rico’s citizens and will have long-term consequences.Conclusion:Lack of resilience in Puerto Rico’s infrastructure and government agencies rendered the island highly vulnerable to the detrimental effects of Hurricane María. Improvements to infrastructures and a transition towards a more sustainable way of life could improve Puerto Rico’s preparation and response to future disasters – natural and human-made.

Evolution of the Munali Intrusive Complex: Host to a carbonate-rich Ni-(Cu-PGE) sulfide deposit

The Munali Intrusive Complex is hosted within supracrustal metasedimentary rocks located along a major structural lineament within the Zambezi Belt in southern Zambia. The complex comprises unmineralised gabbro surrounded by a marginal heterogeneous mafic–ultramafic breccia unit that is host to Ni-Fe sulfide. This marginal unit comprises a range of variably evolved brecciated mafic–ultramafic rocks that include gabbro, olivine-gabbro and dolerite, alongside younger, pegmatitic, apatite-magnetite-bearing clinopyroxenite, wehrlite and dunite. The magmatic evolution is most consistent with a model whereby early mafic rocks interact with hot, MgO- and volatile-rich melts along gabbro contacts, causing localised metasomatism of gabbro and pyroxenites, and progressively replacing pyroxene-rich rocks with olivine, forming pegmatitic ‘replacive dunites’. Sulfide mineralisation is characterised by a carbonate-rich apatite-magnetite-bearing assemblage predominately present as lenses of semi-massive to massive sulfide ore. The complex is enveloped almost entirely within a unit of marble, yet C and O isotope signatures of carbonate at Munali have revealed a clear mantle signature for some of the carbonate associated with sulfide, alongside a more dominant, crustally derived component. The carbonate occurring alongside sulfide displays micro to macro textures signifying the presence of carbonate melts formed from anatectic melting of the country rocks. The presence of fracture sets that define coarse breccia clasts (>1 m) indicate that the host rock was significantly crystallised and brittly deformed prior to carbonate and sulfide melt infiltration. Both carbonate and sulfide melts appear to have independently utilised these pre-existing weaknesses producing a pseudobreccia, and accounting for the seemingly chaotic nature of the orebody. The indication of sulfide being a significantly later phase suggests that the sulfide did not form in situ and was mobilised from elsewhere to be subsequently emplaced late within the Munali system.

The role of pre-existing weaknesses in intraplate metamorphic core complex formation during slab retreat: 2-D thermomechanical modelling

SUMMARY A number of metamorphic core complexes (MCCs) developed in the North China Craton and adjacent regions in the Early Cretaceous and were characterized by consistent extensional orientations. These MCCs formed in the continental interior and were conceptually attributed to the retreat of the Palaeo-Pacific (Izanagi) Plate, but the exact physical mechanism remains enigmatic. Here we utilize 2-D thermomechanical simulations to study how mechanical conditions of the continental crust respond to stresses derived from oceanic subduction and their roles in the formation of MCCs. Our results demonstrate that pre-existing weaknesses are key for localized formation within the continental interior. These weaknesses first undergo compression to form thrust faults in response to shallow subduction of the oceanic slab. These thrust faults gradually transform into extensional ones as the oceanic slab starts to retreat, eventually causing the synchronous exhumation of middle-to-lower crustal rocks that form the MCCs. The P-T paths of metamorphic rocks in the core of MCCs reveal a two-stage exhumation, with isothermal decompression followed by rapid isobaric cooling. Sensitivity tests show that (1) stronger upper crust and weaker lower crust favour MCC formation, while lithospheric strength could exert an influence on the formation time of MCCs and (2) when the continental crust is hot (TMoho = 800 °C), a new magmatic dome could form along the continental margin. We suggest that pre-existing weaknesses in the North China Craton played a key role in generating the quasi-simultaneous MCC series in response to the retreating Palaeo-Pacific Plate.

IN-SIMS zircon U-Pb geochronology from the Snowbird tectonic zone Large igneous Province (STZ LIP), western Churchill Province, Canada

IN-SIMS (in-situ secondary ionization mass spectrometry) micro-zircon geochronology resolves the age of the Chipman and Kazan mafic dike swarms exposed along the central segment of the Snowbird Tectonic Zone (STZ), the geophysically defined feature separating the Rae and Hearne subprovinces of the western Churchill Province. Long-considered syn-kinematic with respect to Paleoproterozoic transpressional deformation, the primitive composition of the STZ Large Igneous Province (LIP) and granulite grade metamorphic overprint has made establishing crystallization ages difficult. In-situ U-Pb isotopic analysis of micro-zircon yielded scattered and discordant results, except for four zircon crystals, which yielded a weighted mean of 2113 Ma +/- 22 (n = 8 analyses; MSWD: 0.46). This age is similar to other mafic complexes in the western Churchill Province including the Griffin Gabbro sills interpreted to have formed during opening of the Manikewan Ocean. Nd isotopic analyses of Kazan dikes paired with geochemical data suggest that the Chipman and Kazan dikes were asthenospherically-derived but contaminated by a metasomatized lithospheric root. At ca. 2.1 Ga, the STZ was the site of intracratonic extension within a coherent Rae-Hearne crustal block (Snowbird LIP Phase I). Existing data suggests that subsequent tectonism led to focused dextral transpression along the trace of the dike swarm and attests to a long-lived interplay of preexisting weaknesses and deformation.

Episodic back-arc spreading centre jumps controlled by transform fault to overriding plate strength ratio

Spreading centre jumps are a common feature of oceanic back-arc basins. Jumps are conventionally suggested to be triggered by plate velocity changes, pre-existing weaknesses, or punctuated events such as the opening of slab windows. Here, we present 3D numerical models of back-arc spreading centre jumps evolving naturally in a homogeneous subduction system surrounded by continents without a trigger event. Spreading centres jump towards their subduction zone if the distance from trench to spreading centre becomes too long. In particular, jumps to a new spreading centre occur when the resistance on the boundary transform faults enabling relative motion of back-arc and neighbouring plates is larger than the resistance to break the overriding plate closer to trench. Time and distance of spreading centres jumps are, thus, controlled by the ratio between the transform fault and overriding plate strengths. Despite being less complex than natural systems, our models explain why narrow subducting plates (e.g. Calabrian slab), have more frequent and closely-spaced spreading jumps than wider subduction zones (e.g. Scotia). It also explains why wide back-arc basins undergo no spreading centre jumps in their life cycle.

Curved orogenic belts, back-arc basins, and obduction as consequences of collision at irregular continental margins

Abstract Continental collisions commonly involve highly curved passive plate margins, leading to diachronous continental subduction during trench rollback. Such systems may feature back-arc extension and ophiolite obduction postdating initial collision. Modern examples include the Alboran and Banda arcs. Ancient systems include the Newfoundland and Norwegian Caledonides. While external forces or preexisting weaknesses are often invoked, we suggest that ophiolite obduction can equally be caused by internal stress buildup during collision. Here, we modeled collision with an irregular subducting continental margin in three-dimensional (3-D) thermo-mechanical models and used the generated stress field evolution to understand resulting geologic processes. Results show how tensional stresses are localized in the overriding plate during the diachronous onset of collision. These stresses thin the overriding plate and may open a back-arc spreading center. Collision along the entire trench follows rapidly, with inversion of this spreading center, ophiolite obduction, and compression in the overriding plate. The models show how subduction of an irregular continental margin can form a highly curved orogenic belt. With this mechanism, obduction of back-arc oceanic lithosphere naturally evolves from a given initial margin geometry during continental collision.

Pregnancy and birth in the United States during the COVID-19 pandemic: The views of doulas.

BackgroundMuch of the emerging research on the effects of SARS‐CoV‐2 disease (COVID‐19) on pregnant people and their infants has been clinical, devoting little attention to how the pandemic has affected families navigating pregnancy and birth. This study examined the perspectives of doulas, or nonclinical labor support professionals, on how pregnancy and birth experiences and maternal health care delivery systems changed in the early weeks of the COVID‐19 pandemic.MethodsSemi‐structured interviews using open‐ended questions were conducted over the phone with 15 birth doulas. Doulas were invited to participate because of their close relationships with pregnant and birthing people and the comprehensive support they offer. The interview transcripts were analyzed inductively.ResultsDoulas’ clients faced three predominant COVID‐19‐related pregnancy and birth challenges: (a) fear of exposure; (b) limited access to their expected support systems; and (c) uncertainties surrounding hospital restrictions on labor and birth. Doulas responded creatively to help their clients confront these challenges. Participants expressed various criticisms of how maternal health care systems handled the emerging crisis, argued that COVID‐19 exposed preexisting weaknesses in US maternity care, and called for a coordinated care model involving doulas.DiscussionDoulas' close relationships with pregnant people enabled them to be an important source of support during the COVID‐19 pandemic. Added to the larger body of work on the impacts of doula care, this study supports widespread calls for universally integrating doulas into maternity care systems as a targeted strategy to better support pregnant and birthing people in both crisis and noncrisis situations.

Impact of Covid-19 Pandemic on Trade

Covid-19 surprised the whole world. It was originally seen as problem for china and then for the South-East Asia. On 17 November 2019 in China, the first COVID-19 infection was identified and on 30 January 2020 in India. As the pandemic continued, many countries had to enter a partial or total lock-down that affected the world economy. China, which was the epicentre of the pandemic, has suffered thousands and thousands of deaths and, at first, had news in the world because the economic trade was not kept too long shut and rapid recoveries were also thought to have occurred. The epidemic Covid-19 definitely very infectious and dangerous disease; spreads rapidly and has a major negative effect on the life and economy(WHO). More than 1 million people have lost their lives since the outbreak in 2019 coronavirus disease (COVID-19), and the global economy is projected to decline by 4.3% in 2020.The virus spreads mainly through small, coughing, sneezing and talking droplets during close contact with people. Instead of travelling over long distances, droplets usually come to the ground or surfaces. Unfortunately, it can be infected by touching and then touching the face of a contaminated surface. It is most contagious in the first three days after symptoms begin, but spreading is possible before symptoms occur and in persons with no symptoms. Millions of jobs are lost, millions of livelihoods are at risk, and another 130 million people are estimated to live in extreme poverty if there is a crisis that continues. This pandemic poses immense challenges and human suffering. The COVID-19 is still unfinished. In many countries there is an increasing number of new COVID-19 cases, while a second wave is already an unhappy situation for many countries. While the pandemic is still highly unclear as to how and when, the unprecedented economic shock caused by the world health crisis has already strongly exposed the pre-existing weaknesses of the world economy and has seriously sparked progress in development around the world. In current literature, the effects of epidemics and pandemics in the manufacturing sector and trades have not been taken into account. Rather, most research on the disruptive effects of public health crises such as these has focused on humanitarian issues, such as the effective distribution of food and other forms of relief (Dasaklis et al. 2012; Ivanov 2020a; Paul &amp; Chowdhury 2020). The effects of these disruptions are serious because these crises have lasting reaction and can have simultaneous impacts on operations at multiple levels, including procurement, production and distribution.

Guidance for Medical Ethicists to Enhance Social Cooperation to Mitigate the Pandemic.

The Covid-19 pandemic has presented major challenges to society, exposing preexisting ethical weaknesses in the modern social fabric’s ability to respond. Distrust in government and a lessened authority of science to determine facts have both been exacerbated by the polarization and disinformation enhanced by social media. These have impaired society’s willingness to comply with and persevere with social distancing, which has been the most powerful initial response to mitigate the pandemic. These preexisting weaknesses also threaten the future acceptance of vaccination and contact tracing, two other tools needed to combat epidemics. Medical ethicists might best help in this situation by promoting truth-telling, encouraging the rational adjudication of facts, providing transparent decision-making and advocating the virtue of cooperation to maximize the common good. Those interventions should be aimed at the social level. The same elements of emphasizing cooperation and beneficence also apply to the design of triage protocols for when resources are overwhelmed. A life-stages approach increases beneficence and reduces harms. Triage should be kept as simple and straightforward as reasonably possible to avoid unwieldly application during a pandemic.

Observations of breakage for transversely isotropic shale using acoustic emission and X-ray computed tomography: Effect of bedding orientation, pre-existing weaknesses, and pore water

Shale is typically an anisotropic material for which the mechanical characteristics can vary significantly along different orientations with regard to its bedding planes. In underground formations, the strength of shale shows strong dependence on the pre-existing weaknesses and the water content. This study is concerned with the mechanical behavior of Marcellus shale specimens under three-point bending where loading is applied in different directions with respect to its bedding plane orientation under both dry and saturated conditions. Acoustic Emission (AE) is recorded in order to investigate the nucleation of microfracturing via AE locations and Moment Tensor Analysis (MTA). Complimentary to the AE detection and analysis, X-ray Computed Tomography (CT) is utilized to image internal damage sustained due to loading. Experimental results show lower nominal tensile strength when bending loads are applied parallel to bedding in dry samples. Further comparisons between tests under different conditions point to the strong impact of the pore water and pre-existing weaknesses on the samples. Detailed results from MTA show tensile microfracturing is the dominant crack type. Surprisingly, event locations show a large number of AE events occur in areas of the beam that are nominally subjected to compressive stress, implying that fracturing can be strongly impacted by local stress fluctuations which may result in opening of the interfaces between bedding layers even when the nominal stress in an area is compressive. In several cases, AE associate with visible fractures in the CT scan which are not connected to the main rupture surface through the specimen. Additionally, visualization of the internal fracture paths using image segmentation on the CT results show more complex fracture systems in parallel loading cases, which brings together localized fractures generated by different mechanisms.

Pre-cenozoic evolution of the northern Qilian Orogen from zircon geochronology: Framework for early growth of the northern Tibetan Plateau

The northern Qilian Shan, located along the northeastern margin of the Tibetan Plateau, experienced multiple phases of orogeny throughout the Phanerozoic, culminating in fold-thrust and strike-slip deformation associated with the Cenozoic India-Asia collision. Earlier phases of deformation in the Qilian Shan have been severely reactivated or transformed by the most recent Cenozoic strain. To better understand the tectonic evolution of this complex region, we conducted an integrated investigation of field observations, U–Pb dating of igneous and detrital zircons, and a synthesis of previously published data to constrain and reconstruct the pre-Cenozoic history of the northern Qilian Shan. This effort reveals five major age populations important to the history of this region: 2550–2350, 1850–1750, 1050–950, 500–435, and 320–240 Ma. Using this dataset, we identified three major depositional shifts and/or variations in drainage patterns that affected sediment provenance of the northern Qilian Orogen. Observed regional geologic constraints, the magmatic history, and new geophysical observations of the deep structure allow us to propose a coherent tectonic model for the pre-Cenozoic evolution of the northeastern margin of the Tibetan Plateau. (1) Late Neoproterozoic to Cambrian rifting opened the Qilian Ocean. (2) Early Cambrian subduction initiation along the margins of Qaidam and North China–Tarim continents resulted in Cambrian-Ordovician bivergent subduction, arc magmatism within these two continents, and consumption of the Qilian Ocean. (3) Final ocean closure and continental collision occurred at ca. 440 Ma and was associated with syn- and post-orogenic magmatism. (4) Collisional orogeny variably eroded the basement rocks, reorganized drainage networks, and altered sedimentary provenance for the lower Paleozoic to upper Paleozoic deposits. (5) Mesozoic extension led to the development of thick Jurassic–Cretaceous terrestrial basins. This pre-Cenozoic history resulted in preexisting weaknesses and/or low-friction detachment horizons that played a decisive role in controlling the pattern, distribution, and timing of Cenozoic deformation across the northern Tibetan Plateau.

Climate migration and health system preparedness in the United States

ABSTRACT Every country will have to prepare for climate change. Despite obvious risks to national security in terms of safety, food, and infrastructure as well as impending economic losses, countries like the United States (US) have declined to pursue meaningful federal action. The human impact of climate change – specifically climate migration and its health implications – has been largely neglected at a policy level. Yet climate migration is predicted to have tremendous consequences for people in the next 30 years and beyond, and with it comes a host of difficulties – political, cultural, economic, and structural. Preparedness will be of great importance to potential migrants and how they adapt to their receiving (host) locations. Health systems are one of the most significant institutions impacting long-term migration and these systems’ strengths and weaknesses will determine the integration and well-being of migrants for years to come. A critical analysis of existing literature exposes that there is little current research on health system preparedness as it relates to climate migration, especially in the US. To help address this gap, this paper focuses on how the American health system, already fraught with limitations, can prepare for the expected increase in mostly internal migrants in the face of climate change. Key policy insights Climate migration in the US will pose huge challenges for health systems because of the American health system’s unique, pre-existing weaknesses. To prepare for climate migration, federal, state, local, tribal, and territorial governments should focus on adopting a universal healthcare policy, shifting primary care tasks away from physicians and towards other qualified and more ubiquitous professionals, and investing in telemedicine, retail clinics, and a national electronic health record system. A ‘health in all policies’ approach, which applies a health lens to legislation, needs to be applied in the context of health system strengthening for climate migration since countless environmental determinants of health and infrastructural decisions shape the vulnerability of communities.

Human factors: the pharmaceutical supply chain as a complex sociotechnical system.

BackgroundThe Covid 19 pandemic has exacerbated pre-existing weaknesses in the global supply chain. Regional assessments by the Food and Drug Administration (FDA), European Medicine Agency (EMA), and independent consultants, have demonstrated various contributory causal factors requiring changes in policy, relationships, and incentives within the dynamic and developing networks. Human Factors/Ergonomics (HFE) is an approach that encourages sociotechnical systems thinking to optimise the performance of systems that involve human activity. The global supply chain can be considered such a system. However, it has neither been systematically examined from this perspective.MethodsIn 2015, the UK Chartered Institute of Ergonomics and Human Factors established the Pharmaceutical Sector Group. This unique group is open to all who work in the pharmaceutical sector at any level and in any discipline who share the vision of a pharmaceutical system that places an understanding of HFE at the heart of improving the use of healthcare products throughout their life cycles including their supply chains.ResultsFor this complex system to work efficiently it is paramount that we have effective coordination and integration between the different elements in the supply chain. HFE can give valuable insights and solutions for developing these complex social-technical systems effectively.ConclusionBy partnering with international groups such as Biophorum and Bio Supply Chain Management Alliance, the wish stimulate discussion about how sociotechnical thinking about HFE may help develop better monitoring and investigative techniques to strengthen global supply chains.