bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development and Demonstration of an Orderly Recruitment Valve for Fluidic Artificial Muscles
Authors: Kim Jeong Yong , Mazzoleni Nicholas , Vemula Dheeraj , Bryant Matthew 
Published: November 2020

Abstract
Variable recruitment fluidic artificial muscle (FAM) bundles consist of multiple FAMs arranged in motor units that are sequentially activated as load demand increases. The conventional configuration of a variable recruitment FAM bundle requires a valve for each motor unit, which is referred to as a multi-valve system (MVS). As each motor unit within the bundle is selectively recruited, this configuration is highly adaptable and flexible in performance. However, as the number of motor units increases, the valve network can become complex and heavy in its design. To decrease complexity and weight, the concept of an orderly recruitment valve (ORV) has been proposed and analyzed. The ORV allows multiple motor units to be controlled using a single valve that recruits and pressurizes all motor units. The ORV concept consists of a spool valve with multiple outlet ports and a motor unit connected to each port. A linear actuator controls the position of the spool, allowing fluid flow into each port in succession. Naturally, de-recruitment happens in reverse order. The objective of the ORV is to strike a balance between performance and compactness of design. The purpose of this paper is to present analytical modeling that can be used to understand the behavior and performance of an ORV system and develop an experimental proof-of-concept that illustrates the ORV operation in hardware. A pneumatic ORV prototype was constructed and used to actuate two FAMs sequentially, each representing a motor unit. The results demonstrate the ORV as a compact system with which a variable recruitment bundle with multiple recruitment states can be controlled.
Fabrication of a 3D Bistable Composite
Authors: Akter Rizwana , Myers Oliver J. 
Published: November 2020

Abstract
Bistable composites have created much attention in engineering applications because of its ability to sustain two stable shapes. A systematic layup of carbon fiber reinforced polymer (CFRP) causes bistability in a lamina. The transition from one stable shape to another is occurred by snap-through and snap-back process. Due to their adaptive nature a lot of study has been conducted on a 2D laminate for over the past 30 years. However, fabrication of a 3D model that exhibits bistability is yet to be explored. In this research we fabricated a 3D bistable composite structure having two parallel cross-ply square laminates connected by a rigid tab at one edge. The entire structure exhibits bistability when the two laminates are actuated simultaneously. The parallel laminates are also independent when actuated individually, making the model achieve four independent stable shapes. Our goal is to understand the bistable behavior and predict the degree of curvature and the snap through response of the solid structure. This paper discusses the fabrication of a solid composite structure that can be further analyzed numerically by creating an FEA model using ABAQUS. The simulation results could be validated experimentally. In this research we also aim to put together an analytical model of this 3D laminate structure. Successful fabrication and mathematical analysis of our 3D laminate using carbon fiber reinforced polymer will hopefully inspire additive manufacturing of bistable composite structure that will lead to more complicated design of bistable materials with more morphing characteristics.
A Novel Bio-Inspired Pneumatic Valve Adapter for Soft Robotic Vasculature
Authors: Saunders Benjamin O. , Swensen John P. 
Published: November 2020

Abstract
This paper proposes a novel pneumatic valve adapter that decreases the size and quantity of pneumatic tubes and valves necessary for soft robotics by mimicking cardiovascular systems. Some cardiovascular systems, evolved to be powered by a single reservoir, the heart, which in turn powers the rest of the body by systematically opening and closing valves as needed. The presented valve adapter consists of a set of concentric tube, where both tubes have strategically patterned holes. The inner tube can be moved translationally and rotationally to align with designated hole positions in the outer tube, thus opening and closing pathways to chambers for pressure flow. The two-tube system can be used to either pressurize a chamber or depressurize a chamber or multiple chambers simultaneously.
Design of Revolute Joint With Bi-Stability Using Permanent Magnets
Authors: Yang Hyeon-Ho , Han Jae-Hung 
Published: November 2020

Abstract
Bi-stable mechanisms are systems with two distinct stable equilibrium positions within their range of operation. They are capable of steadily staying in positions without external power input and require less energy to move to the next stable state because of their snap-through behavior. Diverse applications including switches, deployable structures, and reconfigurable robots can benefit from bi-stability characteristics. However, the complexity of implementation and the limitation of structure configuration have made it difficult to apply conventional bi-stable mechanisms to the structures that require rotational bi-stability. Thus, in this paper, we proposed an implementation method using cylindrical magnets for the rotational bi-stable mechanism.
The proposed bi-stable mechanism consists of a revolute joint with two links; one is the rotational link and the other is the fixed link. It has rotational bi-stability through the magnetic force relationship between the array of magnets on each link. To identify the characteristics of the proposed bi-stable mechanism, a cylindrical permanent magnet is considered as an electromagnet model that consists of one ring with a virtual electric current. Consequently, the magnetic field of the cylindrical permanent magnet can be calculated using Biot-Savart law. Similarly, the magnetic force between two cylindrical permanent magnets of the electromagnet model is calculated using Lorentz force law.
The criteria of the magnet array for symmetric bi-stability are proposed and the potential energy diagram of the rotation link is considered as the performance criterion to identify the stable state.
Real-Time Model Updating Algorithm for Structures Experiencing High-Rate Dynamic Events
Authors: Hong Seong Hyeon , Drnek Claire , Downey Austin , Wang Yi , Dodson Jacob 
Published: November 2020

Abstract
Real-time model updating of active structures subject to unmodeled high-rate dynamic events require structural model updates on the timescale of 2 ms or less. Examples of active structures subjected to unmodeled high-rate dynamic events include hypersonic vehicles, active blast mitigation, and orbital infrastructure. Due to the unmodeled nature of the events of interest, the real-time model updating algorithm should circumvent any model pre-calculations. In this work, we present a methodology that updates the finite element analysis (FEA) model of a structure experiencing varying dynamics through online measurements. The algorithm is demonstrated for a testbed, comprised of a cantilever beam and a roller that serves as movable support. The structure’s state is updated (i.e. the position of the moving roller) by continuously updating the associated FEA model through an online adaptive meshing and search algorithm. The structure’s state is continuously estimated by comparing the measured signals with FEA models. New FEA models are built based on the enhanced estimate of the structure’s state through adaptive meshing for modal analysis and adaptive search space for the FEA model selection. The proposed methodology is verified experimentally in real-time using the testbed. It is demonstrated that the adaptive features can achieve accurate state estimations within the required 2 ms timescale.
A new glacial varve chronology along the southern Laurentide Ice Sheet that spans the Younger Dryas–Holocene boundary
Authors: Breckenridge A. , Lowell T.V. , Peteet D. , Wattrus N. , Moretto M. , Norris N. , Dennison A. 
Published: November 2020

Abstract
Glacial varves can detail ice-margin positions and provide a proxy for meltwater discharge at resolutions comparable to those of the Greenland ice core archives, and thus they can be critical paleorecords for assessing the response of both ancient and modern ice sheets to climate change. Here we provide an ∼1500 yr varve chronology straddling the Younger Dryas (YD)–Holocene boundary (11.65 cal. kyr B.P.), the first such chronology in North America. The varves are from glacial Lake Agassiz (central North America). The chronology is pinned on accelerator mass spectrometry radiocarbon-dated terrestrial macrofossils at the base of a widespread red-clay bed deposited during flooding from the Lake Superior basin. We illustrate the utility of this record by examining ice-margin retreat and melting through the late Younger Dryas and across the Holocene boundary. The ice margin receded at a constant rate, not only during the late YD, but for at least 300 yr after the onset of the Holocene. In contrast, varve thicknesses increased at the boundary, and a moraine formed over a 50 yr period, perhaps in response to the warming climate. Our expectation is that this time series will continue to be developed, expanded, and refined because it promises to be the longest and most geographically extensive glacial varve data set in North America.
Pulsed volcanic combustion events coincident with the end-Permian terrestrial disturbance and the following global crisis
Authors: Kaiho Kunio , Aftabuzzaman Md. , Jones David S. , Tian Li 
Published: November 2020

Abstract
Eruption of the Siberian Traps large igneous province (LIP) is thought to have triggered the Permian-Triassic biological crisis, the largest of the Phanerozoic mass extinctions. Mercury concentration enrichments have been widely used as a proxy for volcanic inputs to sediments, especially for ancient LIP eruptions. However, detailed correlations of magmatic pulses with extinction events in the terrestrial and marine realms are not fully resolved. Here we use paired coronene (a six-ring polycyclic aromatic hydrocarbon, a high-temperature combustion proxy) and mercury spikes as a refined proxy for LIP emplacement. In records from stratigraphic sections in south China and Italy, we identify two sets of paired coronene-mercury spikes accompanied by land plant biomarker spikes, followed by a rapid decrease coinciding with terrestrial ecological disturbance and extinction of marine metazoans. Each short-term episode is likely caused by high-temperature combustion of sedimentary hydrocarbons during initial sill emplacement of the Siberian Traps LIP. These data indicate that discrete volcanic eruptions could have caused the terrestrial ecosystem crisis followed by the marine ecosystem crisis in ∼60 k.y., and that the terrestrial ecosystem was disrupted by smaller global environmental changes than the marine ecosystem.
Normal and abnormal foveal development
Authors: Thomas Mervyn G , Papageorgiou Eleni , Kuht Helen J , Gottlob Irene 
Published: November 2020

Normal foveal development begins in utero at midgestation with centrifugal displacement of inner retinal layers (IRLs) from the location of the incipient fovea. The outer retinal changes such as increase in cone cell bodies, cone elongation and packing mainly occur after birth and continue until 13 years of age. The maturity of the fovea can be assessed invivo using optical coherence tomography, which in normal development would show a well-developed foveal pit, extrusion of IRLs, thickened outer nuclear layer and long outer segments. Developmental abnormalities of various degrees can result in foveal hypoplasia (FH). This is a characteristic feature for example in albinism, aniridia, prematurity, foveal hypoplasia with optic nerve decussation defects with or without anterior segment dysgenesis without albinism (FHONDA) and optic nerve hypoplasia. In achromatopsia, there is disruption of the outer retinal layers with atypical FH. Similarly, in retinal dystrophies, there is abnormal lamination of the IRLs sometimes with persistent IRLs. Morphology of FH provides clues to diagnoses, and grading correlates to visual acuity. The outer segment thickness is a surrogate marker for cone density and in foveal hypoplasia this correlates strongly with visual acuity. In preverbal children grading FH can help predict future visual acuity.
Exercise interventions in lateral elbow tendinopathy have better outcomes than passive interventions, but the effects are small: a systematic review and meta-analysis of 2123 subjects in 30 trials
Authors: Karanasios Stefanos , Korakakis Vasileios , Whiteley Rod , Vasilogeorgis Ioannis , Woodbridge Sarah , Gioftsos Georgios 
Published: November 2020

ObjectiveTo evaluate the effectiveness of exercise compared with other conservative interventions in the management of lateral elbow tendinopathy (LET) on pain and function.DesignSystematic review and meta-analysis.MethodsWe used the Cochrane risk-of-bias tool 2 for randomised controlled trials (RCTs) to assess risk of bias and the Grading of Recommendations Assessment, Development and Evaluation methodology to grade the certainty of evidence. Self-perceived improvement, pain intensity, pain-free grip strength (PFGS) and elbow disability were used as primary outcome measures.Eligibility criteriaRCTs assessing the effectiveness of exercise alone or as an additive intervention compared with passive interventions, wait-and-see or injections in patients with LET.Results30 RCTs (2123 participants, 5 comparator interventions) were identified. Exercise outperformed (low certainty) corticosteroid injections in all outcomes at all time points except short-term pain reduction. Clinically significant differences were found in PFGS at short-term (mean difference (MD): 12.15, (95% CI) 1.69 to 22.6), mid-term (MD: 22.45, 95% CI 3.63 to 41.3) and long-term follow-up (MD: 18, 95% CI 11.17 to 24.84). Statistically significant differences (very low certainty) for exercise compared with wait-and-see were found only in self-perceived improvement at short-term, pain reduction and elbow disability at short-term and long-term follow-up. Substantial heterogeneity in descriptions of equipment, load, duration and frequency of exercise programmes were evident.ConclusionsLow and very low certainty evidence suggests exercise is effective compared with passive interventions with or without invasive treatment in LET, but the effect is small.PROSPERO registration numberCRD42018082703.
Home-related and work-related injuries in Makwanpur district, Nepal: a household survey
Authors: Pant Puspa Raj , Deave Toity , Banstola Amrit , Bhatta Sumiksha , Joshi Elisha , Adhikari Dhruba , Manandhar Sunil Raja , Joshi Sunil Kumar , Mytton Julie A 
Published: November 2020

ObjectiveTo describe the epidemiology of home-related and work-related injuries, their mechanisms, inequalities and costs associated with these injuries.MethodsA household survey was undertaken in three palikas of Makwanpur district between April and June 2019. Data were collected electronically on non-fatal injuries that occurred in the previous 3 months and fatal injuries that occurred in the previous 5 years.Findings17 593 individuals were surveyed from 3327 households. Injury rates were 8.0 per 1000 population for home injuries and 6.4 per 1000 for work-related injuries; 61.0% of home injuries were among women and 69.9% of work-related injuries among men. Falls were the cause of 48% home injuries, affecting 50.9% of men and 46.5% of women. Burns/scalds were higher in women than men, affecting 17.4% of women reporting home injuries. Cuts and piercings accounted for 39.8% of all work-related injuries and 36.3% were falls. Injury incidence varied by ethnic group: home injuries were highest in Brahmin (12.0 per 1000) and work-related injuries highest in Rai groups (21.0 per 1000). The total mean costs (transport and treatment) of work-related injury was US$143.3 (SD 276.7), higher than for home injuries (US$130.4, SD 347.6). The number of home (n=74, 64.9%) and work-related (n=67, 77.9%) injuries were higher in families below the poverty line than families in the next income bracket (home: n=22, 19.3%; work: n=11, 12.8%).ConclusionsHome-related and work-related fall injuries are common. The inequalities in injury identified in our study by rurality, age, sex, income level and ethnic group can help target injury prevention interventions for vulnerable groups.
Associations of APOE e2 genotype with cerebrovascular pathology: a postmortem study of 1275 brains
Authors: Goldberg Terry E , Huey Edward D , Devanand Davangere P 
Published: November 2020

ObjectiveWe assessed the association of apolipoprotein E (APOE) genotype with cerebrovascular disease (CVD) in a large neuropathological database maintained by the National Alzheimer’s Coordinating Center (NACC). Such a comprehensive investigation of APOE and CVD pathology has not heretofore been conducted. We focused on APOE e2, an established neuroprotective genetic variant against Alzheimer’s disease.MethodsTo implement these objectives APOE associations in the NACC database of 1275 brains with 11 CVD pathologies, including old and recent infarcts, haemorrhages, cerebral amyloid angiopathy (CAA) and arteriosclerosis, were examined. These pathologies were uniformly and semiquantitatively measured across 39 Alzheimer’s Disease Center sites. We used χ2 statistics and ordinal regression to assess the significance of associations and Bonferroni corrected for multiple comparisons.ResultsOf the cases, 98 were e2/e3 or e2/e2 genotypes (‘e2’ carriers), 621 were e3 homozygotes (‘e3’ group), and 556 were e4/e3 (442) or e4/e4 (114) genotypes (‘e4’ group). Results indicated that the APOE e4 allele significantly increased risk for CAA. After stratification by CAA presence/absence, we found that in those cases in which CAA was present, APOE e2 significantly increased risk for gross haemorrhage. All other associations were negative.ConclusionsIn this, the largest study of APOE e2 effects on pathologically verified CVD, e2 was not protective against any CVD pathology compared with e3 homozygotes, including CAA. Regarding the latter pathology, e4 was associated with increases in its severity. Furthermore, and perhaps unexpectedly, e2 significantly increased risk of acute/subacute gross haemorrhage in the presence of CAA. Thus, there were limits to e2 neuroprotection against amyloidosis, despite its known and large protective effects against diffuse and neuritic amyloid plaques compared with e3/e3 and e4 carriers in this very collection.
Prevalence, predictors and prognosis of incidental intracranial aneurysms in patients with suspected TIA and minor stroke: a population-based study and systematic review
Authors: Hurford Robert , Taveira Isabel , Kuker Wilhelm , Rothwell Peter M 
Published: November 2020

IntroductionUnruptured intracranial aneurysms (UIAs) are common incidental imaging findings, but there are few data in patients with transient ischaemic attack (TIA)/stroke. The frequency of UIA might be higher due to shared risk factors, but rupture risk might be reduced by intensive secondary prevention. We determined the prevalence and prognosis of UIA in patients with suspected TIA/minor stroke.MethodsAll patients referred to the population-based Oxford Vascular Study (2011–2020) with suspected TIA/minor stroke and non-invasive angiography were included. We determined the prevalence of incidental asymptomatic UIA and the risk of subsequent subarachnoid haemorrhage (SAH) by follow-up on intensive medical treatment, with guideline-based monitoring/management. We also did a systematic review of UIA prevalence/prognosis in cohorts with TIA/stroke.FindingsAmong 2013 eligible patients, 95 (4.7%) had 103 previously unknown asymptomatic UIA. Female sex (OR 2.3, 95% CI 1.5 to 3.7), smoking (2.1, 1.2 to 3.6) and hypertension (1.6, 1.0 to 2.5) were independently predictive of UIA, with a prevalence of 11.1% in those with all three risk factors. During mean follow-up of 4.5 years, only one SAH occurred: 2.3 (95% CI 0.3 to 16.6) per 1000 person-years. We identified 19 studies of UIA in TIA/stroke cohorts (n=12 781), all with either symptomatic carotid stenosis or major acute stroke. The pooled mean UIA prevalence in patients with TIA/stroke was 5.1% (95% CI 4.8 to 5.5) and the incidence of SAH was 4.6 (95% CI 1.9 to 11.0) per 1000 person-years.InterpretationThe 5% prevalence of UIA in patients with confirmed TIA/minor stroke is likely higher than that in the general population. However, the risk of SAH on intensive medical treatment and guideline-based management/monitoring is low.
The Paleoproterozoic porphyry copper–molybdenum deposit of Kourki (Liptako Province, western Niger)
Authors: Hallarou Mallam Mamane , Konaté Moussa , Olatunji Akinade Shadrach , Ahmed Yacouba 
Published: November 2020

Abstract
The Kourki porphyry Cu–Mo deposit is located in the southern part of the Gorouol greenstone belt in Western Niger. The potential Cu–Mo mineralization is hosted by granitoids (granodiorite and diorite) and veins, in Paleoproterozoic plutonic rocks, which are the main porphyry Cu–Mo system. The scientific objective of this study was to determine the characteristics of Kourki Cu–Mo mineralization and to compare them with other porphyry systems in the world and particularly with those of the West African Craton. The methods implemented consist of a field study and a polarizing microscope analysis in transmitted and reflected light on the rocks bearing Cu–Mo mineralization. The use of reference diagrams made it possible, on the one hand, to confirm the origin of the Cu–Mo mineralization and, on the other hand, to specify conditions of the formation of this mineralization. The geology of the study area shows a granodiorite–tonalite pluton in close contact with dioritic intrusions to the north, clastic sediments to the east, and volcano-sedimentary rocks to the SE. The pluton is crosscut by an intrusion of molybdenum porphyry dyke with irregular shape that can be observed in outcrop. The geochemical study shows that the granodiorite–tonalite pluton can be related to a calc-alkaline plutonic series which characterizes an arc type environment. Large areas of hydrothermal quartz breccia have been identified within the pluton. They were set up by hydraulic fracturing along the zones of weakness. Most of the Cu–Mo mineralization in the Kourki deposit occurs as hydrothermal breccia, filled with veins, and was disseminated in the porphyry diorite and quartz–diorite stockworks. The mineralogical assemblage is marked by a predominance of pyrite, molybdenite, chalcopyrite and quartz with some bornite and chalcocite. The alterations include potassic alteration, propylitic alteration, sericitization and epidotization. All of these data show that the Kourki porphyry represents a characteristic system of an environmental arc, quite comparable with that of the Andean Cordillera.