bluuebunny/crossref_metadata_2025 huggingface dataset:
Metaplasia of respiratory and digestive tissues in the Eastern oysterCrassostrea virginicaassociated with the Deepwater Horizon oil spill
Authors: Roopnarine Deanne S. , Roopnarine Peter D. , Anderson Laurie C. , Hwang Ji Hae , Patel Swati
Published: February 2021

Metaplasia is a well documented and deleterious effect of crude oil components on bivalved molluscs, including oysters. This reversible transformation of one cell type to another, is a common response to petroleum-product exposure in molluscs. It has been shown experimentally in previous work that eastern oysters (Crassostrea virginica) exposed to petroleum products will exhibit metaplasia of digestive tissues. Here we document for the first time that wild adult oysters inhabiting coastal waters in the northern Gulf of Mexico during and in the aftermath of the Deepwater Horizon oil spill (2010) exhibited metaplasia in both ctenidia and digestive epithelia at significantly higher levels than geographic controls ofC. virginicafrom Chesapeake Bay. Both ctenidial (respiratory and suspension feeding) and digestive tract tissues exhibited significantly higher frequencies of metaplasia in specimens from the Gulf of Mexico compared to those from Chesapeake Bay. Metaplasia included the loss of epithelial cilia, transformations of columnar epithelia, hyperplasia and reduction of ctenidial branches, and vacuolization of digestive tissues. Evidence for a reduction of metaplasia following the oil spill (2010-2013) is suggestive but equivocal.
Dual MAPK and HDAC inhibition rewires the apoptotic rheostat to trigger colorectal cancer cell death
Authors: Jenkins Laura J. , Luk Ian Y. , Palmieri Michelle , Fairlie W. Douglas , Lee Erinna F. , Schoffer Kael L. , Tan Tao , Ng Irvin , Vukelic Natalia , Tse Janson W.T. , Nightingale Rebecca , Alam Zakia , Iatropoulos George , Ernst Matthias , Afshar-Sterle Shoukat , Desai Jayesh , Gibbs Peter , Sieber Oliver M. , Dhillon Amardeep S. , Tebbutt Niall C. , Mariadason John M.
Published: February 2021

The EGFR/RAS/MEK/ERK signalling pathway (ERK/MAPK) is hyper-activated in most colorectal cancers (CRCs). A current limitation of inhibitors of this pathway is that they primarily induce cytostatic effects in CRC cells. Nevertheless, these drugs do induce expression of pro-apoptotic factors, suggesting they may prime CRC cells to undergo apoptosis. As histone deacetylase inhibitors (HDACi) induce expression of multiple pro-apoptotic proteins, we examined whether they could synergize with ERK/MAPK inhibitors to trigger CRC cell apoptosis. Combined MEK/ERK and HDAC inhibition synergistically induced apoptosis in CRC cell lines and patient-derived tumour organoids in vitro, and attenuated Apc-initiated adenoma formation in vivo. Mechanistically this effect was mediated through induction of the BH3-only pro-apoptotic proteins BIM and BMF. Importantly, we demonstrate that this treatment paradigm can be tailored to specific MAPK genotypes in CRCs, by combining HDACi with EGFR, KRASG12C or BRAFV600 inhibitors in KRAS/BRAFWT; KRASG12C, BRAFV600E CRC cell lines respectively. These findings identify a novel ERK/MAPK genotype-targeted treatment paradigm for colorectal cancer.
Venomics and antivenomics of Indian spectacled cobra (Naja naja) from the Western Ghats
Authors: Vanuopadath Muralidharan , Raveendran Dileepkumar , Nair Bipin Gopalakrishnan , Sadasivan Nair Sudarslal
Published: February 2021

Venom proteome profiling ofNaja najafrom the Western Ghats region in Kerala was achieved through SDS-PAGE and RP-HPLC followed by Q-TOF LC-MS/MS analysis, incorporating PEAKS and Novor assistedde novosequencing methodologies. A total of 115 proteins distributed across 17 different enzymatic and non-enzymatic venom protein families were identified through conventional and 39 peptides through homology-driven proteomics approaches. Fourteen peptides derived throughde novocomplements the Mascot data indicating the importance of homology-driven approaches in improving protein sequence information. Among the protein families identified, glutathione peroxidase and endonuclease were reported for the first time in the Indian cobra venom. Immunological cross-reactivity assessed using Indian polyvalent antivenoms suggested that VINS showed better EC50(2.48 μg/mL) value than that of PSAV (6.04 μg/mL) and Virchow (6.03 μg/mL) antivenoms. Western blotting experiments indicated that all the antivenoms elicited poor binding specificities, especially towards low molecular mass proteins. Second-generation antivenomics studies revealed that VINS antivenom was less efficient to detect many low molecular mass proteins such as three-finger toxins and Kunitz-type serine protease Inhibitors. Taken together, the present study enabled a large-scale characterization of the venom proteome ofNaja najafrom the Western Ghats and emphasized the need for developing more efficient antivenoms.

Highlights

Proteomics of cobra venom resulted in the identification of 115 proteins representing 17 snake venom protein families.

De novoapproaches exclusively yielded 39 peptides harbouring multiple amino acid mutations.

Glutathione peroxidase and endonuclease were identified for the first time in Indian cobra venom.

Indian polyvalent antivenoms showed varying cross-reactivity towards cobra venom.

VINS antivenom was less efficient to detect many low molecular mass proteins (< 20 kDa).
Hidden Talents: Poly (I:C)-induced maternal immune activation improves mouse visual discrimination performance and reversal learning in a sex-dependent manner
Authors: Zhao Xin , Tran Hieu , DeRosa Holly , Roderick Ryland C. , Kentner Amanda C.
Published: February 2021

While there is a strong focus on the negative consequences of maternal immune activation (MIA) on developing brains, very little attention is directed towards potential advantages of early life challenges. In this study we utilized a polyinosine-polycytidylic acid (poly(I:C)) MIA model to test visual discrimination (VD) and reversal learning (RL) in mice using touchscreen technology. Significant sex differences emerged in that MIA reduced the latency for males to make a correct choice in the VD task while females reached criterion sooner, made fewer errors, and utilized fewer correction trials in RL compared to saline controls. These surprising improvements were accompanied by the sex-specific upregulation of several genes critical to cognitive functioning, indicative of compensatory plasticity in response to MIA. In contrast, when exposed to a ‘two-hit’ stress model (MIA + loss of the social component of environmental enrichment (EE)), mice did not display anhedonia but required an increased number of PD and RL correction trials. These animals also had significant reductions of CamK2a mRNA in the prefrontal cortex. Appropriate functioning of synaptic plasticity, via mediators such as this protein kinase and others, are critical for behavioral flexibility. Although EE has been implicated in delaying the appearance of symptoms associated with certain brain disorders, these findings are in line with evidence that it also makes individuals more vulnerable to its loss. Overall, with the right ‘dose’, early life stress exposure can confer at least some functional advantages, which are lost when the number or magnitude of these exposures become too great.
Crystal structure of acetoacetyl-CoA reductase fromRickettsia felis
Authors: Rodarte Justas V. , Abendroth Jan , Edwards Thomas E. , Lorimer Donald D. , Staker Bart L. , Zhang Sunny , Myler Peter J. , McLaughlin Krystle J.
Published: February 2021

Rickettsia felis, a Gram-negative bacterium that causes spotted fever, is of increasing interest as an emerging human pathogen.R. felisand several otherRickettsiastrains are classed as National Institute of Allergy and Infectious Diseases priority pathogens. In recent years,R. felishas been shown to be adaptable to a wide range of hosts, and many fevers of unknown origin are now being attributed to this infectious agent. Here, the structure of acetoacetyl-CoA reductase fromR. felisis reported at a resolution of 2.0 Å. WhileR. felisacetoacetyl-CoA reductase shares less than 50% sequence identity with its closest homologs, it adopts a fold common to other short-chain dehydrogenase/reductase (SDR) family members, such as the fatty-acid synthesis II enzyme FabG from the prominent pathogensStaphylococcus aureusandBacillus anthracis. Continued characterization of theRickettsiaproteome may prove to be an effective means of finding new avenues of treatment through comparative structural studies.
2,3-Dihydro-1H-cyclopenta[b]naphthalene-4,9-dione
Authors: Kotha Sambasivarao , Fatma Ambareen , Ansari Saima
Published: February 2021

The title compound, C13H10O2, crystallizes with two almost planar molecules in the asymmetric unit. In the crystal, slipped π–π stacking interactions help to establish the packing with the shortest centroid–centroid separation being 3.8195 (18) Å.
Constraints and opportunities facing construction organization in post-conflict condition in Afghanistan
Authors: Amarkhil Qais , Elwakil Emad
Published: February 2021

Purpose

Although there are many challenges and constraints for construction organization operation and performance in a post-conflict condition, there is insufficient construction project management literature. Therefore, the purpose of this paper is to identify a framework to understand and determine critical constraints and opportunities in a post-conflict condition facing local construction firms in Afghanistan. The proposed framework is composed of three major steps: identify and determine key performance indicators; identify challenges impacting organization operation and performance in post-conflict condition; determine critical constraints and opportunities based on prioritized performance measures; and organizational strength and weakness factors.

Design/methodology/approach

The strength, weakness, opportunities and threat matrix analysis has been used to determine post-conflict condition constraints and opportunities. Then the analytical hierarchy process has been used to prioritize the measures and identify the constraints and opportunities facing construction companies in a post-conflict situation. The mix-research method is applied to this study to analyse qualitative variables and quantitative variables obtained from the experts’ opinions and 51 filled questioners.

Findings

The study shows that there are a total of 11 critical constraints and three essential opportunities for construction companies that industry practitioners and policymakers should take into account while formulating the organizational strategy.

Practical implications

The developed framework will benefit construction companies in improving their performance and operation in after-conflict conditions.

Originality/value

This paper is the first to provide a comprehensive conceptualization of the challenges and constraints for construction organization operation and performance in a post-conflict condition. It also offers a novel conceptual framework to understand and determine critical constraints and opportunities in a post-conflict condition facing local construction firms in Afghanistan.
Reducing the risks of endoscopic sinonasal surgery in the Covid‐19 era
Authors: Leong Samuel C. , Mogre Dilesh , Andrews Peter , Davies Elgan
Published: February 2021

Objectives

Many routine sinonasal procedures utilising powered instruments are regarded as aerosol‐generating. This study aimed to assess how different instrument settings affect detectable droplet spread and patterns of aerosolised droplet spread during simulated sinonasal surgery in order to identify mitigation strategies.

Design

Simulation series using three‐dimensional (3‐D) printed sinonasal model. Fluorescein droplet spread was assessed following microdebriding and drilling of fluorescein‐soaked grapes and bones, respectively.

Setting

University dry lab.

Participants

3‐D printed sinonasal model.

Main outcome measures

Patterns of aerosolised droplet spread.

Results and Conclusion

There were no observed fluorescein droplets or splatter in the measured surgical field after microdebridement of nasal polyps at aspecific irrigation rate and suction pressure. Activation of the microdebrider in the presence of excess fluid in the nasal cavity (reduced or blocked suction pressure, excessive irrigation fluid or bleeding) resulted in detectable droplet spread. Drilling with either coarse diamond or cutting burs resulted in detectable droplets and greater spread was observed when drilling within the anterior nasal cavity. High‐speed drilling is a high‐risk AGP but the addition of suction using a third hand technique reduces detectable droplet spread outside the nasal cavity. Using the instrument outside the nasal cavity inadvertently, or when unblocking, produces greater droplet spread and requires more caution.
First experience of POLARx™ versus Arctic Front Advance™: An early technology comparison
Authors: Creta Antonio , Kanthasamy Viijayabharathy , Schilling Richard J. , Rosengarten James , Khan Fakhar , Honarbakhsh Shohreh , Earley Mark J. , Hunter Ross J. , Finlay Malcom
Published: February 2021

Introduction

Cryoballoon ablation is an established technique to achieve pulmonary vein isolation in patients with atrial fibrillation (AF). Recently, a new manufacturer of cryoballoon achieved regulatory CE marking (POLARx™; Boston Scientific). We describe our early experience of using this new market entrant of the technology and describe procedural aspects in comparison to the incumbent Medtronic Arctic Front Advance™.

Methods

We assessed the first 40 AF ablations performed with the POLARx catheter at the Barts Heart Centre. These patients were compared with a contemporaneous series of patients undergoing ablation by the same operators using the Arctic Front Advance. Procedural metrics were prospectively recorded.

Results

A total of four operators undertook 40 cases using the POLARx catheter, compared with 40 cases using the Arctic Front Advance. Procedure times (60.0 vs. 60.0 min) were similar between the two technologies, however left atrial dwell time (35.0 vs 39.0 min) and fluoroscopy times (3.3 vs. 5.2 min) were higher with the POLARx. Measured nadir and isolation balloon temperatures were significantly lower with POLARx. Almost all veins were isolated with a median freezing time of 16.0 (POLARx) versus 15.0 (Arctic Front Advance) min. The rate of procedural complications was low in both groups.

Conclusion

The POLARx cryoballoon is effective for pulmonary vein isolation. Measured isolation and nadir temperatures are lower compared with the predicate Arctic Front Advance catheter. The technology appears similar in acute efficacy and has a short learning curve, but formal dosing studies may be required to prove equivalence of efficacy.
Nursing students’ experience and training in healthcare aid during the COVID‐19 pandemic in Spain
Authors: Hernández‐Martínez Antonio , Rodríguez‐Almagro Julián , Martínez‐Arce Alejandro , Romero‐Blanco Cristina , García‐Iglesias Juan Jesús , Gómez‐Salgado Juan
Published: February 2021

Background

During the COVID‐19 pandemic health crisis, in some countries such as Spain, nursing students have offered to provide health assistance, but the role they have played, their degree of preparedness to face the situation, and what must be improved in their training to be ready for these situations is unknown.

Objective

Describe the experience and perceptions of students of the Nursing university degree during their participation as health support in the COVID‐19 health crisis in Spain.

Design

We conducted a cross‐sectional survey study.

Method

503 students enrolled in the 4th course of the Nursing degree in Spain during the months of March and April 2020. An online questionnaire was developed, based on a pilot study and distributed through the Nursing Association, students’ unions and students’ associations. Variables were used to describe their participation, degree of preparedness and training needs to determine how to improve training through descriptive statistics, as well as nonparametric tests to analyse the relationship between training and degree of preparedness nursing students. Results are reported according to the STROBE Statement.

Results

73.2% (368) of students offered to participate in healthcare aid, of which 225 were actively involved. 27.8% carried out nursing tasks without supervision, and 47.7% assisted COVID‐19 patients as any other nurse. Only 3.4% felt very prepared to work in the field of intensive care, finding that those students who perceived a higher degree of preparedness had received previous training in personal protective equipment and mechanical ventilation (p < 0.005). The highest scores for training activities that may improve their preparedness were simulations to improve levels of anxiety and stress when managing critical patients, simulation in ventilatory support and mandatory practices in services where ventilators are used.

Conclusions

Although three out of four students were willing to provide health assistance, they recognise that they were not specially prepared in the field of intensive care and demand training with simulation to improve anxiety and stress levels in the management of critical patients and simulation in ventilatory support.

Relevance to clinical practice

Students have been vital resources for our health system and society when they have been needed. It is now up to us, both teachers and health authorities, to share their efforts by implementing the necessary improvements in training and safety measures not only because these affects the health and safety of the patient, but because they will be essential parts in future pandemics.
Strategic and cultural contexts of real options reasoning in innovation portfolios
Authors: Kaufmann Carsten , Kock Alexander , Gemünden Hans Georg
Published: February 2021

Decision makers find creating an innovation portfolio challenging, because more innovative projects are associated with a higher degree of uncertainty. In this study, we investigate the potential benefits of applying real options reasoning (ROR) in innovation portfolio management from an attention‐based view. Using a sample of 137 innovation portfolios with multiple informants, we investigate ROR's influence on portfolio innovativeness and, ultimately, on portfolio success in a mediated model. Further, we analyze the moderating influence of an innovation portfolio's organizational context—entrepreneurial orientation and innovation climate—on ROR's application. The results support ROR's positive relationship to portfolio innovativeness and portfolio success. The analysis also supports the positive interaction between entrepreneurial orientation and ROR with respect to portfolio innovativeness. This study contributes to the literature by demonstrating the relationship between ROR and portfolio success, mediated by portfolio innovativeness. In addition, the study's analysis offers an explanation of previously mixed findings regarding ROR's benefits by considering the firm's strategic and cultural innovation contexts. The findings underline the relevance of strategic support for ROR's effectiveness in innovation portfolio management. Furthermore, the findings encourage managers to implement ROR, but also stress the essential contribution an entrepreneurial orientation makes when the managers do so.
Widespread bacterial utilization of guanidine as nitrogen source
Authors: Sinn Malte , Hauth Franziskus , Lenkeit Felina , Weinberg Zasha , Hartig Jörg S.
Published: February 2021

Guanidine is sensed by at least four different classes of riboswitches that are widespread in bacteria. However, only very few insights into physiological roles of guanidine exist. Genes predominantly regulated by guanidine riboswitches are Gdx transporters exporting the compound from the bacterial cell. In addition, urea/guanidine carboxylases and associated hydrolases and ABC transporters are often found combined in guanidine‐inducible operons. We noted that the associated ABC transporters are configured to function as importers, challenging the current view that riboswitches solely control the detoxification of guanidine in bacteria. We demonstrate that the carboxylase pathway enables utilization of guanidine as sole nitrogen source. We isolated three enterobacteria (Raoultella terrigena, Klebsiella michiganensis, and Erwinia rhapontici) that utilize guanidine efficiently as N‐source. Proteome analyses show that the expression of a carboxylase, associated hydrolases and transport genes is strongly induced by guanidine. Finding two urea/guanidine carboxylase enzymes in E. rhapontici, we demonstrate that the riboswitch‐controlled carboxylase displays specificity toward guanidine, whereas the other enzyme prefers urea. We characterize the distribution of riboswitch‐associated carboxylases and Gdx exporters in bacterial habitats by analyzing available metagenome data. The findings represent a paradigm shift from riboswitch‐controlled detoxification of guanidine to the uptake and assimilation of this enigmatic nitrogen‐rich compound.
Several geranylgeranyl diphosphate synthase isoforms supply metabolic substrates for carotenoid biosynthesis in tomato
Authors: Barja M. Victoria , Ezquerro Miguel , Beretta Stefano , Diretto Gianfranco , Florez‐Sarasa Igor , Feixes Elisenda , Fiore Alessia , Karlova Rumyana , Fernie Alisdair R. , Beekwilder Jules , Rodríguez‐Concepción Manuel
Published: February 2021

Geranylgeranyl diphosphate (GGPP) produced by GGPP synthase (GGPPS) serves as a precursor for many plastidial isoprenoids, including carotenoids. Phytoene synthase (PSY) converts GGPP into phytoene, the first committed intermediate of the carotenoid pathway.

Here we used biochemical, molecular, and genetic tools to characterise the plastidial members of the GGPPS family in tomato (Solanum lycopersicum) and their interaction with PSY isoforms.

The three tomato GGPPS isoforms found to localise in plastids (SlG1, 2 and 3) exhibit similar kinetic parameters. Gene expression analyses showed a preferential association of individual GGPPS and PSY isoforms when carotenoid biosynthesis was induced during root mycorrhization, seedling de‐etiolation and fruit ripening. SlG2, but not SlG3, physically interacts with PSY proteins. By contrast, CRISPR‐Cas9 mutants defective in SlG3 showed a stronger impact on carotenoid levels and derived metabolic, physiological and developmental phenotypes compared with those impaired in SlG2. Double mutants defective in both genes could not be rescued.

Our work demonstrates that the bulk of GGPP production in tomato chloroplasts and chromoplasts relies on two cooperating GGPPS paralogues, unlike other plant species such as Arabidopsis thaliana, rice or pepper, which produce their essential plastidial isoprenoids using a single GGPPS isoform.
The Effect of Laser Bio‐modulation on Dysplastic Lesions, an Animal Study
Authors: Pourshahidi Sara , Ghasem Zadeh Hoseini Elaheh , Shirazian Shiva , Ebrahimi Hooman , Chiniforush Nasim , Alaeddini Mojgan , Etemad‐Moghadam Shahroo , Amaral Mendes Rui
Published: February 2021

Potentially malignant disorders are one of the clinical challenges. Dysplasia in these lesions can be a predictor of more potential for malignant changes. Photo‐bio‐modulation in benign lesions has advantages, but there is doubt on its safety in potentially malignant lesions. This study aims to assess if low‐level laser can promote dysplastic changes while the method can play an important role in management of dysplastic lesions. Dysplasia was induced on anterior wall of the buccal pouch of 80 young Syrian male hamsters. Then, hamsters were divided to four groups to receive 4 and 12 sessions irradiation of 660 and 810 nanometers low‐level lasers. For histopathologic study of the tissue, we used light microscopes. Using SPSS, data were analyzed via Wilcoxon signed rank test and Mann–Whitney U‐test. In all of our four groups, the severity of dysplasia had no statistical difference in study sides comparing with their own controls. Wavelength and numbers of laser irradiation sessions had no statistically meaningful effect on the severity of dysplasia either. Low‐level lasers appear to show no relevant or significant effect over the aggravation of the dysplasia's severity. Neither the wavelength nor the number of sessions appear to have any impact in the results.
Neural markers of procrastination in white matter microstructures and networks
Authors: Chen Zhiyi , Liu Peiwei , Zhang Chenyan , Yu Zeyuan , Feng Tingyong
Published: February 2021

More than 15% of adults suffer from pathological procrastination, which leads to substantial harm to their mental and psychiatric health. Our previous work demonstrated the role of three neuroanatomical networks as neural substrates of procrastination, but their potential interaction remains unknown. Three large‐scale independent samples (total n = 901) were recruited. In sample A, tract‐based spatial statistics (TBSS) and connectome‐based graph‐theoretical analysis was conducted to probe association between topological properties of white matter (WM) network and procrastination. In sample B, the above analysis was reproduced to demonstrate replicability. In sample C, machine learning models were built to predict individual procrastination. TBSS results showed a negative association between procrastination and WM integrity of limbic‐prefrontal connection, and a positive relationship between intra‐connection within the limbic system and procrastination. Also, both the efficiency and integrity of limbic WM network were found to be linked to procrastination. The above findings were all confirmed to replicate in an independent sample; prediction models demonstrated that these WM features can predict procrastination accurately in sample C. In conclusion, this study moves forward our understanding of procrastination by clarifying the role of interplay of self‐control and emotional regulation with it.
D‐index as a marker of bloodstream infections in patients with allogeneic hematopoietic stem cell transplantation
Authors: Vijayvargiya Prakhar , Lara Abad Cybele , Esquer Garrigos Zerelda , O'Horo John C. , Walker Randall C. , Hogan William J. , Tande Aaron J.
Published: February 2021

Background

Neutropenia is a risk factor for development of infections; however, the direct effect of neutropenia on development of bloodstream infection (BSI) is not known. D‐index, which is area between the neutrophil time curve and a neutrophil count of 0.5 × 109/L, incorporates the combined effect of severity and duration of neutropenia. We aimed to evaluate whether D‐index can be used as a marker for BSI in patients with allogeneic stem cell transplantation.

Method

We conducted a retrospective cohort study of patients undergoing allogeneic stem cell transplantation between January 1, 2005, and September 30, 2015. The primary outcome measure was the development of BSI within 30 days of transplantation.

Results

A total of 714 patients were included in the study of whom 101 developed BSI. Patients with BSI had a significantly higher median D‐index value compared with patients who did not have BSI (4990 vs. 3570, P < .001). As a marker, the performance of the D‐index was similar to that of the duration of profound neutropenia (P = .18) and significantly better than the total duration of neutropenia (P = .001).

Conclusion

The D‐index performed better than the total duration of neutropenia as a marker for BSI in patients with allogeneic stem cell transplantation. There was no difference between D‐index and, a more easily calculable indicator, duration of profound neutropenia.
An Efficient Assisted Bidirectional Glenn Design With Lowered Superior Vena Cava Pressure for Stage-One Single Ventricle Patients
Authors: Jia Dongjie , Peroni Matthew , Khalapyan Tigran , Esmaily Mahdi
Published: February 2021

Recently, the assisted bidirectional Glenn (ABG) procedure has been proposed as an alternative to the modified Blalock–Taussig shunt (mBTS) operation for neonates with single-ventricle physiology. Despite success in reducing heart workload and maintaining sufficient pulmonary flow, the ABG also raised the superior vena cava (SVC) pressure to a level that may not be tolerated by infants. To lower the SVC pressure, we propose a modified version of the ABG (mABG), in which a shunt with a slit-shaped nozzle exit is inserted at the junction of the right and left brachiocephalic veins. The proposed operation is compared against the ABG, the mBTS, and the bidirectional Glenn (BDG) operations using closed-loop multiscale simulations. Both normal (2.3 Wood units-m2) and high (7 Wood units-m2) pulmonary vascular resistance (PVR) values are simulated. The mABG provides the highest oxygen saturation, oxygen delivery, and pulmonary flow rate in comparison to the BDG and the ABG. At normal PVR, the SVC pressure is significantly reduced below that of the ABG and the BDG (mABG: 4; ABG: 8; BDG: 6; mBTS: 3 mmHg). However, the SVC pressure remains high at high PVR (mABG: 15; ABG: 16; BDG: 12; mBTS: 3 mmHg), motivating an optimization study to improve the ABG hemodynamics efficiency for a broader range of conditions in the future. Overall, the mABG preserves all advantages of the original ABG procedure while reducing the SVC pressure at normal PVR.
An Inconspicuous, Integrated Electronic Travel Aid for Visual Impairment
Authors: Boldini Alain , Garcia Andy Louis , Sorrentino Marc , Beheshti Mahya , Ogedegbe Okpe , Fang Yi , Porfiri Maurizio , Rizzo John-Ross
Published: February 2021

With a globally aging population, visual impairment is an increasingly pressing problem for our society. Visual disability drastically reduces quality of life and constitutes a large cost to the health care system. Mobility of the visually impaired is one of the most critical aspects affected by this disability, and yet, it relies on low-tech solutions, such as the white cane. Many avoid solutions entirely. In part, reluctance to use these solutions may be explained by their obtrusiveness, a strong deterrent for the adoption of many new devices. Here, we leverage new advancements in artificial intelligence, sensor systems, and soft electroactive materials toward an electronic travel aid with an obstacle detection and avoidance system for the visually impaired. The travel aid incorporates a stereoscopic camera platform, enabling computer vision, and a wearable haptic device that can stimulate discrete locations on the user’s abdomen to signal the presence of surrounding obstacles. The proposed technology could be integrated into commercial backpacks and support belts, thereby guaranteeing a discreet and unobtrusive solution.
A Simplified Algorithm for Count Rate Processing in Radiation Monitors That Address Statistical Fluctuations and Spurious Counts
Authors: Nanda Biswamohan , Madhavi Voleti , Suguna Devi S. V. , Balachandran R.
Published: February 2021

While processing the signals from radiation detectors, for finding the true mean-count-rate, algorithms with hybrid pulse collection methodology have been proposed and used over the years. An algorithm based on this technique with a new methodology of adoption and implementation including spurious rejection is proposed here. It enables a specified and controllable error when the mean-count-rate remains within certain predefined limits from its true value. Effort is made to optimize the response time of prediction at low count rates preserving the optimum possible relative-standard-deviation (RSD). Chi-squared test is utilized for verifying the counting system to check if the observed fluctuations are consistent with the expected statistical fluctuations. A C-program code has been developed to test the algorithm. An observed set of detector outputs are given as input to the program and the corresponding Output is analyzed. A comparative study between the proposed method and floating-mean method is presented for the same set of observations. A typical short-lived high voltage (HV) induced spurious noise pattern is fed as input to the program verifying limited-spurious rejection capability of the algorithm. An embedded C program was written for microcontroller implementation of the algorithm. Case-study of a neutron roentgen equivalent man (REM) counter is presented for evaluating response time for various ranges of operation with calculation of RSD at these ranges. This general-purpose algorithm can enhance the read-out accuracy of radiation monitors used for radiation safety applications.
Numerical and Experimental Modeling of the Thermal Flow in a Modern Rotary Transfer Machine
Authors: Robusto Francesco , Croccolo Dario , De Agostinis Massimiliano , Fini Stefano , Olmi Giorgio , Rizzitelli Marco , Vincenzi Nicolò
Published: February 2021

The aim of this study is to estimate the relative displacement between the spindle nose and the clamping vice in a rotary transfer machine due to temperature variations. The study was focused on the relative displacements caused by temperature variations produced by two heat sources: the environment around the machine and the three-axis computer numerical control station during the duty cycle. Regarding the last point, an analytical model was developed, in order to account for different thermal sources inside the three-axis module (e.g., ball-screws, rolling bearings, and guideways friction heat, as well as heat generation in the motor). The complete numerical model was calibrated and successfully validated. A comparison was run between numerical results and experimental data in the framework of trials involving a newly developed transfer machine. Finally, the complete model, considering the combination of both the heat sources, has made it possible to estimate spindle nose-clamp relative displacement during a typical working day, highlighting that the radial displacement risks affecting seriously the accuracy of a workpiece.
Analysis of the Positioning Process of Objects by the System of Oblique Friction Force Fields on the Example of the MSC Adams Model
Authors: Piatkowski Tomasz , Wolski Miroslaw
Published: February 2021

The paper concerns modelling of the rotational positioning process of cuboid objects with the system of oblique friction force fields produced by two conveyors. These conveyors are used when introducing streams of objects onto trays of the cross-belt sorting system. The purpose of positioning is to place the objects parallel to the edges of the trays with the greatest possible precision. The positioning precision depends on the choice of the conveyors’ motion velocities and conveyors’ position to each other, which can be determined on the basis of numerical simulations. During theoretical analyses, contact and friction models available in the MSC Adams environment were taken into account.
Experiment Study for Evaluation of Phase Change Material Cooling Vest’s Effectiveness at Two Melting Points Used by People With Paraplegia During Exercise
Authors: Mneimneh Farah , Ghaddar Nesreen , Ghali Kamel , Moussalem Charbel , Omeis Ibrahim
Published: February 2021

Phase change material (PCM) cooling vests were tested on people with thoracic (T1-T12) spinal cord injury (SCI), also called people with paraplegia (PA), during exercise in heat. The purpose was to reduce heat stress, limit the increase in core temperature, and improve thermal comfort for PA under high metabolic rates and hot ambient conditions. This health risk was a result of thoracic SCI and disruption of thermoregulatory responses in PA. The current study aims to evaluate the efficacy of cooling vest on PA during arm-crank exercise at two melting points, 20°C (V20) and 14°C (V14) compared to no vest test (NV).

Eleven participants with high- (T1-T3) and mid-thoracic SCI (T4-T8) were selected to participate in three tests. Core and skin temperatures and heart rate values were measured during 15-min precondition, 30-min exercise and 15-min recovery. Subjective voting of thermal comfort, sensation, skin wettedness and perceived exertion were recorded during exercise only. The main findings revealed significant reduction in change in core temperature (0.42±0.3°C;0.38±0.2°C) in V20 and V14 compared to NV tests for mid-thoracic group. For high-thoracic group, V20 and V14 were least effective in reducing core temperature (p > 0.05). Improvements in thermal comfort was established when using V14 and V20 compared to NV by 85% and 30% for high-thoracic group and by 72% and 53% for mid-thoracic group.
Fluid Structure Interaction Simulation of a Benchmark Configuration With a Stress Blended-Eddy Simulation Model
Authors: Pratomo Hariyo P. S.
Published: February 2021

In this work, the application of a shear stress transport based-RANS/LES turbulence modelling approach on a fluid-structure interaction (FSI) benchmark is considered after a transient computation of turbulent flow over the configuration on an LES quality mesh is to be performed. Within the unsteady decoupled simulation the scale resolving method successfully produces complex unsteady eddy sizes behind the reference test case. At a subcritical Reynolds number, a numerical Strouhal number of 0.184 which is close to a reference value of 0.18 is demonstrated by the RANS/LES turbulence model. In this scenario, a rubber added on the back part of a fixed circular cylinder is treated as a rigid thin plate during the pure flow simulation. On the LES grid resolution, the shielding function resided in the hybrid limiter of the scale resolving formulation is found to be strong to safeguard the activation of the RANS mode in the near wall region where the demarcation line between the RANS and LES modes uniquely resembles the geometry. Moreover, in the FSI simulation resolved turbulence scales interacting with moving and deforming rubber immersed in the subcritical Reynolds number-turbulent flow are successfully captured by the hybrid modelling technique coupled with a structural solver under the coupling procedure of an implicit partitioned approach. Similar with earlier studies with different scale-resolving proposals on the same FSI case, a periodic oscillating motion of the rubber that is produced from a phase-averaging method is also demonstrated in this present investigation. Nevertheless, a non-physical deformation of the rubber in the spanwise direction occurs. The new FSI result is evaluated with existing results from earlier works as a pivotal basis for further researches, such as implementations of new mesh stiffness model and filter width.
Re-Sizable Quadrupedal Robot Platform: HARQ
Authors: Sohn Kiwon , Hussain Salman , Bradnan Matthew , May Owen
Published: February 2021

This paper presents the development of kinematically adjustable quadrupedal robot platform, HARQ (Human Assistive and Robust Quadruped) which has been designed and built by ART (Assistive Robot Team) in University of Hartford since 2019. The main objective of HARQ is to assist various tasks of human workers in dangerous work environments such as disasters. In this paper, the mechanical design and building processes of HARQ which focused on kinematic adaptivity and low-cost manufacturing as its main technical design requirements are described first. Then, the kinematic analysis and its implementation in the low-level body controller of the quadrupedal robot are described. Lastly, HARQ is tested and evaluated both in a simulated environment using its virtual model and in an outdoor environment using the physically built platform with various whole body motions which are designed for the robot’s navigation.
Energetic and Economic Potential for Load Control for Residential Customers in Austin, TX
Authors: Bandyopadhyay Arkasama , Conger Julia P. , Beagle Emily A. , Webber Michael E. , Leibowicz Benjamin D.
Published: February 2021

This study uses a linear optimization framework to evaluate the effect of different demand response (DR)/load control mechanisms on reduction in peak load and energy consumption from the electricity grid in a home with four major controllable appliances — HVAC (heating, ventilation, and air-conditioning) systems, electric water heaters (EWHs), electric vehicles (EVs), and pool pumps (PPs). Two incentive-based DR methods and four price-based DR schemes — real time pricing (RTP), time-of-use (TOU) rates, critical peak prices (CPP), and variable peak prices (VPP) — are analyzed. Load reduction potential is evaluated for scenarios where the home has both onsite solar and storage, only solar, and no solar or storage. Results show that, from the utility’s perspective, the optimal load control schemes, which result in greatest reduction in peak load and energy consumption from the grid during peak hours, are CPP and VPP (critical price option). By considering the combined effect of demand response, solar generation, and energy storage systems, this study aims to equip electric utilities with the ability to make decisions about dynamic rate design and direct load control to curtail peak demand and shift energy usage.
Manufacturing Capability Index of 3D Printing Parts for Impact Applications
Authors: Schmitz Anne
Published: February 2021

Three-dimensional (3D) printing with high-resolution stereolithography (SLA) has grown in popularity for creating personalized medical devices. 3D printing is now starting to expand to weight-bearing components, e.g. prosthetic feet, as data on the dynamic properties impact and fatigue is published in the literature. The next step towards using 3D printing in impact applications is to assess the capability of the high-resolution SLA process to manufacture components of uniform impact resistance. Because impact testing is destructive, a surrogate measure to check a part’s viability for resisting an impact load also needs to be established. Thirteen notched Izod specimens were printed on a Form2 SLA printer using the manufacturer’s clear V4, photocurable resin. Once all the specimens were printed, washed in isopropyl alcohol, and cured with ultraviolet light, the impact resistance was quantified using a pendulum impact tester in a notched Izod configuration. Then, the hardness of the specimens was quantified using a HBW 10/250 scale. The impact resistance of the clear, SLA polymer was 0.59 ± 0.14 ft-lb/in. With an upper standard limit of 0.53 ft-lb/in, the process capability index was 0.133. Impact resistance and Brinell hardness were not correlated with a Spearman coefficient of r = −0.108, p = 0.73. Since the process capability index was less than one, 3D printing with SLA polymers is not a viable manufacturing process for creating parts of consistent impact resistance. The current technology would lead to too many rejected parts. Also, Brinell hardness and impact strength were not related. Therefore, there is no non-destructive method to spot-check these components before use.
Finite Frequency Robust Vibration Control of Flexible-Rigid Coupled Spacecraft
Authors: Xu Shidong
Published: February 2021

This paper is concerned with robust vibration control of flexible-rigid coupling spacecraft with finite frequency constraint. Considering that the major vibration energy of flexible structure is induced by the vibration modes located in a specific frequency range, the dynamics of the considered spacecraft are derived as a system with given vibration modes. A novel robust finite frequency controller is proposed by using output feedback method, which focuses on suppressing the vibration modes in given frequency region. Compared with the classic entire frequency controller, the newly proposed controller can achieve better vibration attenuation performance. Finally, illustrative simulation results are provided to demonstrate the effectiveness and superiority of our proposed control method.
Data Modeling and Workflow Analysis of Cyber-Manufacturing Systems
Authors: Song Zhengyi , Moon Young
Published: February 2021

Cyber-Manufacturing System (CMS) is a vision for the factory of the future, where physical manufacturing resources and processes are integrated with computational workflows to provide on-demand, adaptive, and scalable manufacturing services. In CMS, functional manufacturing components in a factory floor are digitized and encapsulated in production services; and are accessible by users throughout the network. CMS utilizes data-centric technologies to program manufacturing activities in factory floors. Leveraging advanced technologies, CMS can provide robust solutions to achieve better manufacturing agility, flexibility, scalability, and sustainability than from traditional factories.

While data is the main driver of the manufacturing activities in CMS, the lack of (i) a generic data model of explicit representation of the entities and stakeholders in CMS and (ii) workflow definition and analysis for service-orientated functionalities and manufacturing intelligence of CMS is still hindering the implementation of a fully executable CMS. To address such problems, this paper (i) formalizes a data modeling of CMS using Entity-Relationship (E-R) diagram, (ii) presents the definition and analysis of workflows along with data pipelines and Extract/Transform/Load (ETL) processes that automate the entire lifecycle activities in CMS and (iii) deploys the proposed data model and workflows in a Web-based application, and (iv) tests the functionality of this application with an industrial case and eventually validates the proposed data model and workflows.
Flow Induced by a Two Stage Electrohydrodynamic Gas Pump in a Square Channel
Authors: Mazumder A. K. M. Monayem H. , Trombley Grace S. , Cusinio Brendon G.
Published: February 2021

In this study, fluid flow induced by a two stage electrohydrodynamic (EHD) gas pump in a square channel has been evaluated by experimental measurement and numerical simulations. This study is implemented for a two stage EHD gas pump with three emitting electrode configurations: 8, 24, and 56 respectively to seek the relation between the number of stages and emitting electrodes. The EHD pump is evaluated for a wide range of operating voltages starting from 20 kV up to 28 kV for further improvement in its performance over a single stage. To achieve the maximum enhancement, the emitting electrodes of the EHD gas pump are flush mounted on the channel walls so that the corona wind produced directly disturbs the boundary layer thickness and improves the heat transfer. This is leading to a higher velocity near the channel walls and resulting in an inverted parabolic velocity profile at the center of the channel, which is opposite to the fully developed velocity profile of a forced flow. Velocities are measured at three cross-sections along the tube length and then integrated to obtain the volume flow rate. The results show that EHD technique has a great potential for many engineering applications.
A Study of the Effect of Extended Hounsfield Unit Range and Voxel Size on Defect Detection in Friction Stir Welds
Authors: Baydoun Ahmad M. R. , Hamade Ramsey F.
Published: February 2021

Friction stir welding (FSW) is a novel welding method that is garnering attention, in part, due to its ability to join dissimilar materials. One of the challenges in producing dissimilar friction welded joints is ensuring the welds are defect-free. Nondestructive testing (NDT) methods such as ultrasonic waves, gamma rays, X-rays, and X-ray CT, are gaining popularity as a method to detect internal defects in FSW joints.

In this study, dissimilar AA1050-AA6061-T6 FSW lap welds are Manufactured and then examined using an NDT X-ray CT technique. The effects of two critical X-ray CT scanning parameters (voxel size and Hounsfield unit (HU)) on the detection of internal defects are investigated. The samples are scanned via X-ray CT at two different voxel sizes (2.457 E−02 and 1.420 E−03 mm3) and two HU ranges (12-bit and 16-bit depth). The generated Digital Imaging and Communications in Medicine (DICOM) images are segmented based on a proper HU threshold found via the Otsu thresholding method. The findings show that Small voxel size (higher resolution) improves the ability of detecting internal defects and improves the effectiveness of the thresholding process. Higher HU range results in a wider separation between detected material peaks, thus enhancing the effectiveness of the thresholding process as well.