bluuebunny/crossref_metadata_2025 huggingface dataset:
Advanced pathway engineering for phototrophic putrescine production
Authors: Freudenberg Robert A. , Wittemeier Luisa , Einhaus Alexander , Baier Thomas , Kruse Olaf
Published: June 2022

The polyamine putrescine (1,4‐diaminobutane) contributes to cellular fitness in most organisms, where it is derived from the amino acids ornithine or arginine. In the chemical industry, putrescine serves as a versatile building block for polyamide synthesis. The green microalga Chlamydomonas reinhardtii accumulates relatively high putrescine amounts, which, together with recent advances in genetic engineering, enables the generation of a powerful green cell factory to promote sustainable biotechnology for base chemical production. Here, we report a systematic investigation of the native putrescine metabolism in C. reinhardtii, leading to the first CO2‐based bio‐production of putrescine, by employing modern synthetic biology and metabolic engineering strategies. A CRISPR/Cas9‐based knockout of key enzymes of the polyamine biosynthesis pathway identified ornithine decarboxylase 1 (ODC1) as a gatekeeper for putrescine accumulation and demonstrated that the arginine decarboxylase (ADC) route is likely inactive and that amine oxidase 2 (AMX2) is mainly responsible for putrescine degradation in C. reinhardtii. A 4.5‐fold increase in cellular putrescine levels was achieved by engineered overexpression of potent candidate ornithine decarboxylases (ODCs). We identified unexpected substrate promiscuity in two bacterial ODCs, which exhibited co‐production of cadaverine and 4‐aminobutanol. Final pathway engineering included overexpression of recombinant arginases for improved substrate availability as well as functional knockout of putrescine degradation, which resulted in a 10‐fold increase in cellular putrescine titres and yielded 200 mg/L in phototrophic high cell density cultivations after 10 days.
Predictive competitive intelligence with prerelease online search traffic
Authors: Schaer Oliver , Kourentzes Nikolaos , Fildes Robert
Published: June 2022

In today's competitive market environment, it is vital for companies to gain insight about competitors' new product launches. Past studies have demonstrated the predictive value of prerelease online search traffic (PROST) for new product forecasting. Relying on these findings and the public availability of PROST, we investigate its usefulness for estimating sales of competing products. We propose a model for predicting the success of competitors' product launches, based on own past product sales data and competitor's prerelease Google Trends. We find that PROST increases predictive accuracy by more than 18% compared to models that only use internally available sales data and product characteristics of video game sales. We conclude that this inexpensive source of competitive intelligence can be helpful when managing the marketing mix and planning new product releases.
Postfire restoration seeding success increases with early fall seeding and simulated precipitation in the Great Basin Desert of North America
Authors: Bishop Tara B. B. , Lee Molinari Rebecca , St. Clair Samuel B.
Published: June 2022

Climate forecasts and disturbance mapping increasingly inform strategies for ecological restoration practices. Our study objectives were to understand how a postfire rehabilitation seed mix responds to fire, seeding timing, and changes in fall precipitation timing due to climate change. We planted seeds commonly used in the Great Basin Desert of North America on soil cores in a randomized block design. We imposed two experimental treatments, experimental fire (burned seedbeds or unburned seedbeds) and timing of seeding with simulated precipitation (early September vs. mid‐October) in a two‐way factorial design. We measured seedling emergence (1 month posttreatment), plant density, biomass, and seed production. Early seeding and precipitation reduced seedling emergence over 2‐fold but increased total plant density (3‐fold), biomass (13‐fold), and seed production (140‐fold) compared to delayed seeding and precipitation applications. Antelope bitterbrush was the only species with a negative response to early seeding and precipitation, with a decrease in both density and biomass (over 2‐fold) by the end of the study. Burned seedbeds overall had little effect on measured outcomes for the total plant community. Burned seedbeds decreased forb seedling emergence 2‐fold and alfalfa and Lewis blue flax density almost 3‐fold but increased overall forb seed production 7‐fold while other species and functional groups had minimal responses. Earlier seeding and precipitation interacted with the effects of burned seedbeds to increase biomass of Wyoming big sagebrush and western yarrow. The positive response of species to earlier fall seeding and precipitation underscores the importance of adapting our restoration practices for changing climate conditions.
Trade‐offs at applying tree nucleation to restore degraded high Andean forests in Colombia
Authors: Barrera‐Cataño José I. , Garibello Juan , Moreno‐Cárdenas Carolina , Basto Sofía
Published: June 2022

Tree islands, the more recognizable type of applied nucleation, and passive restoration have been proven as cost‐effective restoration strategies. Comparison between them is a priority, particularly through paired experiments in ecosystems wherein restoration research is scarce, such as high forest in the northern Andes (high Andean forests [HAF]). This ecosystem is important given its environmental benefits but also because vegetation development is more limited by abiotic conditions, unlike tropical moist forests. To address these gaps, we set up an experiment in a logged pine plantation comparing the effect of nuclei and passive restoration on vegetation structure and diversity as well as natural regeneration. In this case, we divided emergent shoots into three functional groups related to restoration goals: invasive herbs, páramo species, and woody recruits. After 3 years, nuclei had higher coverage, height, and diversity, but this was exclusively due to planted trees, as nuclei did not affect the abundance of invasive herbs and páramo species. More importantly, the abundance and richness of woody recruits were kept low and constant under nuclei, likely as a by‐product of plantation density. Conversely, it gradually increased at passive restoration plots. Since nuclei contribute to structure and diversity and passive restoration contributes to woody recruits, we propose a combination of both to restore HAF. Possible changes in the direction of the interaction between planted trees and recruits confirm the need for long‐term monitoring to accurately determine the potential of tree nuclei in HAF.
Variation on a theme: the structures and biosynthesis of specialized fatty acid natural products in plants
Authors: Scott Samuel , Cahoon Edgar B. , Busta Lucas
Published: June 2022

Plants are able to construct lineage‐specific natural products from a wide array of their core metabolic pathways. Considerable progress has been made toward documenting and understanding, for example, phenylpropanoid natural products derived from phosphoenolpyruvate via the shikimate pathway, terpenoid compounds built using isopentyl pyrophosphate, and alkaloids generated by the extensive modification of amino acids. By comparison, natural products derived from fatty acids have received little attention, except for unusual fatty acids in seed oils and jasmonate‐like oxylipins. However, scattered but numerous reports show that plants are able to generate many structurally diverse compounds from fatty acids, including some with highly elaborate and unique structural features that have novel bioproduct functionalities. Furthermore, although recent work has shed light on multiple new fatty acid natural product biosynthesis pathways and products in diverse plant species, these discoveries have not been reviewed. The aims of this work, therefore, are to (i) review and systematize our current knowledge of the structures and biosynthesis of fatty acid‐derived natural products that are not seed oils or jasmonate‐type oxylipins, specifically, polyacetylenic, very‐long‐chain, and aromatic fatty acid‐derived natural products, and (ii) suggest priorities for future investigative steps that will bring our knowledge of fatty acid‐derived natural products closer to the levels of knowledge that we have attained for other phytochemical classes.
The regional whole blood program in San Antonio, TX: A 3‐year update on prehospital and in‐hospital transfusion practices for traumatic and non‐traumatic hemorrhage
Authors: Braverman Maxwell A. , Smith Allison A. , Ciaraglia Angelo V. , Radowsky Jason S. , Schauer Steven G. , Sams Valerie G. , Greebon Leslie J. , Shiels Michael D. , Jonas Rachelle Babbitt , Ngamsuntikul Samantha , Waltman Elizabeth , Epley Eric , Rose Tracee , Bynum James A. , Cap Andre P. , Eastridge Brian J. , Stewart Ronald M. , Jenkins Donald H. , Nicholson Susannah E. ,   the San Antonio Whole Blood Consortium
Published: June 2022

Low titer type O Rh‐D + whole blood (LTO + WB) has become a first‐line resuscitation medium for hemorrhagic shock in many centers around the World. Showing early effectiveness on the battlefield, LTO + WB is used in both the pre‐hospital and in‐hospital settings for traumatic and non‐traumatic hemorrhage resuscitation. Starting in 2018, the San Antonio Whole Blood Collaborative has worked to provide LTO + WB across Southwest Texas, initially in the form of remote damage control resuscitation followed by in‐hospital trauma resuscitation. This program has since expanded to include pediatric trauma resuscitation, obstetric hemorrhage, females of childbearing potential, and non‐traumatic hemorrhage. The objective of this manuscript is to provide a three‐year update on the successes and expansion of this system and outline resuscitation challenges in special populations.
Receipt of at least 4 units of low titer group O whole blood with titer <100 does not lead to hemolysis in adult trauma patients
Authors: Yazer Mark H. , Corcos Alain , L Sperry Jason , Triulzi Darrell J. , Leeper Christine
Published: June 2022

Background

The serological safety of transfusing low titer group O whole blood (LTOWB) with an anti‐A and anti‐B titer of <100 was evaluated in group O and non‐group O trauma recipients.

Methods

Civilian adult trauma patients who received ≥4 units of leukoreduced LTOWB during their initial resuscitation and who survived for >24 h after admission at two level 1 trauma centers were included in this retrospective study. Lactate dehydrogenase (LDH), total bilirubin, haptoglobin, potassium, creatinine were evaluated on the day of LTOWB transfusion (day 0) and on the next 3 days.

Results

There were 77 injured recipients evaluated: 39 non‐group O and 38 group O. The median (IQR) number of transfused LTOWB units was 4 (4–6) and 4 (4–5), respectively, and the maximum number of units was 8 and 11, respectively. The non‐group O patients received a median (IQR) volume of 1710 ml (1368–2070) of ABO‐incompatible plasma. Comparing non‐group O to group O recipients, there were no significant differences in the median haptoglobin, LDH, or creatinine concentrations at any time point. The median concentration of total bilirubin was significantly higher amongst the non‐group O recipients on days 1 and 2, while on day 0 the median potassium concentration was significantly higher amongst the group O recipients. All median elevated values were within the laboratory's normal range. Amongst the non‐group O recipients there were no reported transfusion reactions.

Conclusion

Receiving at least four LTOWB units (anti‐A&B titer <100) was not associated with biochemical/clinical evidence of hemolysis in adult trauma patients.
The effectiveness of ERAS guidelines in reducing postoperative pain
Authors: McCall Erica , Shores Ryan , McDonough John
Published: June 2022

Background

Poorly controlled acute postsurgical pain can promote chronic opioid use and misuse long after the initial surgical procedure. Enhanced recovery after surgery (ERAS) guidelines have shown promise in reducing opioid exposure and minimizing opioid‐related side effects.

Aims

The aims of this evidence‐based practice (EBP) project were to assess the ERAS literature to guide postoperative pain management practice change at an adult colorectal surgical unit, evaluate the practice change outcomes, and disseminate the findings.

Methods

A Population, Intervention, Comparison, Outcome, and Time (PICOT) question was established to guide an ERAS literature search. Found articles were critically appraised using the FULD Critical Appraisal Tool. Following the critical appraisal, the steps of EBP were utilized to implement an ERAS guideline for adult colorectal surgical patients in a 281‐bed medical center. Outcomes of the practice change were evaluated by comparing multimodal analgesic, regional anesthesia, and opioid pain medication use before and after guideline implementation.

Results

Five articles were critically appraised for guideline development. After implementation, data demonstrated an increase in the use of multimodal analgesics and regional anesthesia and a decrease in the use of opioid pain medication. These findings were disseminated through multiple venues within the hospital, including a presentation to the stakeholders.

Linking Evidence to Action

Evidence‐based strategies to reduce postoperative pain are achievable while reducing perioperative opioid consumption. Engagement of key stakeholders and timely rollout of EBP changes are important for successful implementation. ERAS guidelines with a multimodal analgesia pathway are an effective way to reduce postoperative pain and perioperative opioid consumption.
Structural Topology Optimization of Reactionless Four-Bar Linkages
Authors: Emmanuel Ayala-Hernández J. , Briot Sébastien , Jesús Cervantes-Sánchez J.
Published: June 2022

Classical dynamic balancing techniques do not consider the linkage elastic behavior. For mechanism or robot design purpose, taking into account the flexibility of the multibody system is of utmost importance, in order to be able to manufacture a mechanism/robot which is stiff enough for a given task. This paper deals with a novel approach that allows to design mechanisms by means of structural topology optimization while specific dynamic balancing conditions are considered. In our work, the links are treated as three-dimensional flexible bodies, and the optimization process is performed for all the bodies simultaneously. Applying this methodology, the optimal design of a dynamically balanced four-bar linkage is accomplished while its compliance is minimized. Numerical validations of the optimized linkage properties are carried out using commercial software. The dynamic balancing performance of the optimized four-bar linkage is numerically validated using adams. Besides, ansys software was used in order to perform the linkage stiffness analysis and to compare it with the results of the optimization solver. In order to verify the feasibility of the proposed methodology, a prototype is built. Experimental studies are carried out in order to evaluate its dynamic balancing performance.
Better colloidal lithography: Tilt-rotate evaporation overcomes the limits of plasma etching
Authors: Caso MaCayla J. , Benton Michael G. , McPeak Kevin M.
Published: June 2022

Colloidal lithography (CL) is a promising method for large-area fabrication of nanohole and nanodot arrays with applications in optical biosensing, separations, and magnetic data storage. However, reducing the diameter of the polystyrene sphere mask by plasma etching unavoidably increases their coefficient of variation (CV) and deforms their shape, thereby limiting the pitch-to-hole-diameter ratio of the resulting nanohole array to less than 3:1 and the minimum hole size to 200 nm with a 10% or better CV. We show that tilt-rotate evaporation colloidal lithography (TRE-CL) breaks the trade-off between hole diameter and polydispersity by leveraging glancing angle evaporation, not plasma etching, to adjust the hole size. TRE-CL allows pitch-to-hole-diameter ratios as high as 7:1 and nanohole diameters down to 60 nm while maintaining a nearly constant CV below 10% and hole circularity above 91%. We transfer these hole arrays into ultrathin Si3N4 films to form nearly-monodisperse microsieves for separation applications. Furthermore, we extend TRE-CL to fabricate adhesion-layer-free plasmonic Au nanodot arrays down to 70 nm in diameter with 10% CV.
Effect of Supplementary Physical Training on Vertical Jump Height in Professional Ballet Dancers
Authors: Escobar-Álvarez Juan A. , Jiménez-Reyes Pedro , Da Conceição Filipe A. , Fuentes-García Juan P.
Published: June 2022

Dancers require many specific dance skills of a ballistic nature. The design of supplementary training to improve the strength of the lower limbs and jump height is a relevant area of research. The purpose of this study was (1) to compare the effect of plyometric training versus combined training on countermovement jump (CMJ), squat jump (SJ), and sauté in first position (sauté) height and (2) to observe whether changes in CMJ and SJ were associated with changes in sauté in female and male dancers. Eighty-one classical professional ballet dancers (41 women and 40 men, age = 22.9 [3.7] y, body mass = 59.7 [8.6] kg, height = 167.4 [7.3] cm) were divided into a control group and 2 experimental groups: plyometric training and combined training. All groups followed their common routine of training regarding classes and rehearsal practice, whereas the experimental groups added 2 sessions (1 h per session) for 9 weeks of supplementary training. Significant increases (medium to large effect size) in CMJ, SJ, and sauté height were found in the pretest versus posttest comparisons for both experimental groups. Significant, very large correlations were found between the magnitude of improvement in sauté and the magnitude of improvement in CMJ and SJ. Plyometric and combined training programs are effective ways to improve jumping ability in professional dancers. The improvement in CMJ and SJ has a good transference on sauté `performance. These findings support the use of traditional training methods to improve jump height in specific and nonspecific ballet jumping ability.
Chimpanzees (
Pan troglodytes
) navigate to find hidden fruit in a virtual environment
Authors: Allritz Matthias , Call Josep , Schweller Ken , McEwen Emma S. , de Guinea Miguel , Janmaat Karline R. L. , Menzel Charles R. , Dolins Francine L.
Published: June 2022

Almost all animals navigate their environment to find food, shelter, and mates. Spatial cognition of nonhuman primates in large-scale environments is notoriously difficult to study. Field research is ecologically valid, but controlling confounding variables can be difficult. Captive research enables experimental control, but space restrictions can limit generalizability. Virtual reality technology combines the best of both worlds by creating large-scale, controllable environments. We presented six chimpanzees with a seminaturalistic virtual environment, using a custom touch screen application. The chimpanzees exhibited signature behaviors reminiscent of real-life navigation: They learned to approach a landmark associated with the presence of fruit, improving efficiency over time; they located this landmark from novel starting locations and approached a different landmark when necessary. We conclude that virtual environments can allow for standardized testing with higher ecological validity than traditional tests in captivity and harbor great potential to contribute to longstanding questions in primate navigation, e.g., the use of landmarks, Euclidean maps, or spatial frames of reference.
Data on the Neutron–Neutron Scattering Length from the nd-Breakup Reaction at En = 8 MeV and En = 11 MeV
Authors: Konobeevski E. S. , Kasparov A. A. , Mordovskoy M. V. , Zuyev S. V. , Potashev S. I. , Afonin A. A. , Mitcuk V. V.
Published: June 2022

A kinematically complete experiment devoted to studying the $$nd$$-breakup reaction at energies of 8 and 11 MeV via detecting all three secondary particles was performed. The $${}^{1}S_{0}$$ neutron–neutron ($$nn$$) scattering-length values of $$a_{nn}={-}19.8\pm 0.4$$ and $${-}19.0\pm 0.5$$ fm at, respectively, $$E_{n}=8$$ and $$11$$ MeV were obtained from a comparison of the experimental dependence of the yield of the $$nd$$-breakup reaction on the relative energy of the $$nn$$ pair with the results of a simulation. An analysis of the values obtained for the $$nn$$ scattering length, together with data from other experiments, confirms the hypothesis that three-nucleon forces affect the parameters of $$nn$$ interaction that are extracted from reactions involving few-nucleon systems and gives a new asymptotic $$nn$$ scattering length, $$a_{nn}={-}16.1\pm 0.1$$ fm.
Carcinoid ovary with synchronous carcinoid tumour of the appendix: report of a rare occurrence with review of literature
Authors: Baruah Upasana , Tak Apoorva , Kakoti Lopamudra , Barmon Debabrata
Published: June 2022

Carcinoid tumours are present in a wide range of organs but most frequently involve the gastrointestinal tract and rarely reported in gynaecological organs. Literature reports that the prevalence of ovarian carcinoid is 0.3%–1% of ovarian neoplasms and accounts for only 5% of ovarian teratomas. The pathogenesis of neuroendocrine tumours associated with synchronous primaries is undetermined and many theories have been proposed, such as existence of a common carcinogenic effect or a common stem cell undergoing similar genetic mutation. Paracrine or autocrine growth loop effect by the secretory peptides of the neuroendocrine cell tumours is also suggested. Since carcinoids are variably positive in neuroendocrine and organ-specific markers, there are no immunohistochemistry markers to delineate the definite primary site of origin versus metastasis. We report a rare case of carcinoid ovary with synchronous carcinoid tumour of the appendix. In our case, the presence of contralateral teratomatous elements may hint primary struma carcinoid instead of being metastatic from the appendix. A strumal carcinoid component was also highlighted by PAX8 positivity. This led us to conclude the case as concurrent appendix carcinoid with struma carcinoid as two independent primaries with uncertain pathogenesis. Histologically, as both tumours are well differentiated with Ki-67 of less than 3%, the decision of the joint tumour board was to keep the patient on surveillance, with no adjuvant treatment needed. The patient is currently on surveillance and the follow-up period of 24 months to date has been uneventful.
Use of circulating tumour DNA in nasopharyngeal carcinoma to detect minimal residual disease
Authors: Ghimire Bipin , Herrman Emma , Karki Ujjwal , Chisti Mohammad Muhsin
Published: June 2022

Circulating tumour DNA (ctDNA) is defined as short DNA sequences shed by tumour cells into the systemic circulation. A promising use of ctDNA includes the detection of minimal residual disease (MRD) and is currently being studied in multiple types of solid tumours. Literature for the use of individualised ctDNA in nasopharyngeal carcinoma (NPC) is not available, although circulating Epstein-Barr virus DNA level is validated as a prognostic factor. We present a man in his 40s diagnosed with stage IV NPC who was started on chemotherapy with cis-platinum and gemcitabine. Serial monitoring of ctDNA completed to aid in detecting MRD after treatment demonstrated initial up-trending values correlating with subsequent imaging findings showing progression. Reinitiation of a different chemotherapy regimen significantly improved the ctDNA level, with corresponding imaging exhibiting a similar response. This case provides insight into the potential use of ctDNA in NPC and the benefit of serial ctDNA monitoring during treatment.
Correlation of ex vivo and in vivo confocal microscopy imaging ofAcanthamoeba
Authors: Alantary Noor , Heaselgrave Wayne , Hau Scott
Published: June 2022

Background/aims

The aim of this study was to correlate the various forms ofAcanthamoebaon ex vivo confocal microscopy (EVCM) with in vivo confocal microscopy (IVCM) and findings from cultured positive cases ofAcanthamoeba keratitis.

Methods

Acanthamoebalive, dead and empty cysts, and live trophozoites were prepared in vitro and inoculated into porcine cornea using a sterile 26-gauge needle and examined ex vivo using the Heidelberg Retina Tomograph II/Rostock Corneal Module. IVCM images from 12 cultured positiveAcanthamoebacases, obtained using the same instrument, were compared with EVCM findings. Phase contrast images were also obtained to compare with both EVCM and IVCM findings. The change in cyst morphology with depth was evaluated by imaging the same cysts over a defined cornea depth measurement.

Results

EVCM morphologies for live cysts included four main types—hyper-reflective central dot with hyper-reflective outer ring, hyper-reflective central dot with hyporeflective outer region, stellate shaped hyper-reflective centre with hyporeflective outer region and hyper-reflective round/polygonal shaped cyst; one main type for dead cysts—hyper-reflective central dot with hyporeflective outer region; two main types for empty cysts— hyper-reflective central dot with hyper-reflective outer ring/hyporeflective outer region; and one main type for trophozoites—large coarse speckled area of heterogeneous hyper-reflective material. Matching IVCM images show good correlation with EVCM. Cyst morphology altered when imaged at different depths.

Conclusion

EVCM demonstrated the various forms ofAcanthamoebacyst and trophozoites can be used as a reference to identify similar structures on IVCM.
Nivolumab in patients with relapsed or refractory peripheral T-cell lymphoma: modest activity and cases of hyperprogression
Authors: Bennani N Nora , Kim Hyo Jin , Pederson Levi D , Atherton Pamela J , Micallef Ivana N , Thanarajasingam Gita , Nowakowski Grzegorz S , Witzig Thomas , Feldman Andrew L , Ansell Stephen M
Published: June 2022

Peripheral T-cell lymphomas (PTCL), a heterogeneous group of mature aggressive non-Hodgkin’s lymphomas, carry a worse prognosis for most subtypes when compared with their B-cell counterparts. Despite recent approval of newer therapies, the outlook for patients with relapsed/refractory (RR) PTCL remains poor and new treatment strategies are clearly needed. Targeting the profoundly immunosuppressive tumor microenvironment in PTCL is one such approach. To determine whether immune checkpoint blockade targeting program death receptor 1 would be effective in PTCL, we conducted an investigator-initiated phase 2 prospective study of single-agent nivolumab for RR PTCL. We report here results of the pre-specified interim analysis.

Methods

The primary objective was to assess the overall response rate (ORR). Secondary objectives were to assess safety and tolerability of nivolumab in PTCL and to assess progression-free survival (PFS), duration of response (DOR) and overall survival (OS). Hyperprogressive disease (HPD) was defined as time-to-treatment failure of less than or equal to one month from initiation of therapy.

Results

Twelve patients who received at least one cycle of nivolumab were included in this interim analysis. Half (6/12) of the patients had angioimmunoblastic T-cell lymphoma (AITL), 3/12 had PTCL, not otherwise specified. Most (11/12) were advanced stage, had extranodal disease (97.1%) and had received a prior autologous stem cell transplant (50%). The ORR was 33% (95% CI: 12.3 to 63.7%) with two complete response and two partial response. The median PFS was however short at 2.7 months (95% CI: 1.5 to NE); and the median OS was 6.7 months (95% CI: 3.4 to NE). The median DOR was also short at 3.6 months (95% CI: 1.9 to NE). HPD occurred in four patients, three of whom had AITL. Observed grade 3 and higher adverse events (AEs) were non-hematologic in 5/12 (42%), while hematologic AEs were seen in 3/12 (25%).

Conclusions

Nivolumab had modest clinical activity in R/R PTCL. Due to a high number of hyperprogression and short DOR, a decision was made to halt the study. These findings likely reflect the distinct biology of PTCL and should be considered when designing future studies using checkpoint inhibitors in these diseases.

Trial registration number

NCT03075553.
Analytical characterization of choline chloride in oilfield process waters and commercial samples by capillary electrophoresis
Authors: Tran Vi T. , Catenza Karizza F. , Donkor Kingsley K. , Schmidt Kenneth J. , Crabtree H. John , Warrender Neil A.
Published: June 2022

In this study, a rapid and sensitive method using capillary electrophoresis with indirect UV detection and minimal sample pretreatment was developed and evaluated to analyze choline chloride in oilfield process water samples. To improve peak resolution and separation of choline chloride from other cations present in the samples, the addition of a cationic visualization agent in the background electrolyte, imidazole, and a complexing agent, 18-crown-6, were introduced. Other factors affecting separation and sensitivity were also investigated. Under optimized conditions, choline chloride was baseline separated (<7 min) from common cationic adulterants in commercial choline chloride products with a peak resolution of >1.5 between adjacent peaks. The limits of detection (signal-to-noise ratio = 3) and quantitation (signal-to-noise ratio = 10) were 14.7 and 48.9 mg L−1, respectively. The peak area and migration time’s intraday and interday precision (percent RSD) were all <15%, and the recoveries ranged from 79.4% to 115.2% at different spiking levels. Finally, statistical (Student’s t-test) comparison of the choline chloride content data of oilfield process water samples from the proposed capillary electrophoresis (CE) method compare favourably with traditional methods such as liquid chromatography – mass spectrometry (LC–MS) and Reinecke salt gravimetry.
Canada's forage fish: an important but poorly understood component of marine ecosystems
Authors: Boldt Jennifer L. , Murphy Hannah M. , Chamberland Jean-Martin , Debertin Allan , Gauthier Stéphane , Hackett Brooke , Hagel Paige S. , Majewski Andrew R. , McDermid Jenni L. , Mérette David , Robinson Cliff L.K. , Rooper Christopher N. , Sherbo Bryanna , Van Beveren Elisabeth , Walkusz Wojciech
Published: June 2022

Forage fish form a critical trophic link in marine ecosystems, and yet, for many species, there is limited information available. As nations move from single species stock assessments to ecosystem approaches to fisheries management (EAFMs), more information on forage fish will be required. In this study, 50 years of scientific literature were systematically mapped for 11 forage fish species in Canada's Arctic, Atlantic, and Pacific oceans. The objectives were to identify (1) knowledge clusters and gaps and (2) the pressures studied in relation to forage fish outcomes. Of the 2897 articles mapped, the majority studied adults and the distribution, productivity, growth, and life history of commercially fished species. Knowledge gaps were identified for forage fish: (1) that were noncommercially exploited; (2) egg and larval life history stages of most species and juveniles of noncommercial species; (3) diets of most species; (4) migration and performance for all species and survival of noncommercial species; and (5) the effects of some pressures (e.g., large-scale climate pressures). Addressing these knowledge gaps would improve the application of EAFMs.
Baryon asymmetry from Barrow entropy: theoretical predictions and observational constraints
Authors: Luciano Giuseppe Gaetano , Saridakis Emmanuel N.
Published: June 2022

We investigate the generation of baryon asymmetry from the corrections brought about in the Friedman equations due to Barrow entropy. In particular, by applying the gravity-thermodynamics conjecture one obtains extra terms in the Friedmann equations that change the Hubble function evolution during the radiation-dominated epoch. Hence, even in the case of standard coupling between the Ricci scalar and baryon current they can lead to a non-zero baryon asymmetry. In order to match observations we find that the Barrow exponent should lie in the interval $$0.005\lesssim \Delta \lesssim 0.008$$

0.005
≲
Δ
≲
0.008

, which corresponds to a slight deviation from the standard Bekenstein–Hawking entropy. The upper bound is tighter than the one of other observational constraints, however the interesting feature is that in the present analysis we obtain a non-zero lower bound. Nevertheless this lower bound would disappear if the baryon asymmetry in Barrow-modified cosmology is generated by other mechanisms, not related to the Barrow modification.
Joint Optimization of Multiple Supply Chains Under Cap-And-Trade Regulation: A Bi-Level Programming Model and Solution Algorithm
Authors: Avval Akram Esmaeili , Dehghanian Farzad , Pirayesh Mohammadali
Published: June 2022

Among the carbon regulation policy schemes, the cap-and-trade has received more attention because of its efficiency and flexibility. Two primary challenges with the cap-and-trade scheme are determining the correct cap and carbon trading price in the carbon market. This paper presents a bi-level model to investigate these two challenges in the cap-and-trade scheme formed between multiple supply chains and the government. At the first level, the government minimizes the cap in such a way that the costs of the supply chains do not rise too much. At the second level, the supply chains minimize their costs according to their cap and trade the dedicated allowances. An exact and a heuristic method are developed to solve the bi-level model. The computational results on a set of randomly generated instances show the effectiveness of the presented heuristic. Sensitivity analysis demonstrates that the government should choose proper amounts of caps to balance costs and environmental benefits.
Quantum fluctuations of fields and stress tensors
Authors: Ford L. H.
Published: June 2022

This is a review of recent work on quantum fluctuations of the electric field and of stress tensor operators and their physical effects. The probability distribution for vacuum fluctuations of the electric field is Gaussian, but that for quadratic operators, such as the energy density, can have a more slowly decreasing tail, leading to an enhanced probability of large fluctuations. This effect is very sensitive to the details of how the measurement is performed. Some possible physical effects of these large fluctuations will be discussed.
Probabilistic Progressive Failure of Multiwall Carbon Nanotube-Reinforced Composite Plate Under Transverse Patch Loading
Authors: Lal Achchhe , Magar Ashok , Gamit Divyang
Published: June 2022

Second-order statistics of progressive failure response of multiwall carbon nanotube-reinforced composite (MWCNTRC) plate subjected to the transverse loading is presented. The mathematical model is based on the higher-order shear deformation theory (HSDT) and von Karman nonlinear kinematics through the mechanics of the material approach. Second-order perturbation technique (SOPT) and polynomial chaos (PC) methods are used for the uncertainty quantification. The properties of the MWCNTRC plate are obtained by using the Halpin–Tsai model. Epoxy-matrix reinforced with multiwall carbon nanotube (MWCNT) is considered as a new matrix and boron fiber is reinforced with this new matrix in an orthotropic way to get MWCNTRC. The distribution of volume fraction of carbon nanotube (CNT) in the epoxy matrix is considered in the functionally graded (FG) manner for thermo-mechanical loading. Stochastic progressive failure analysis (PFA) along with the probability of failure of MWCNTRC plate is performed by using the progressive damage model incorporated in the ply discount method and considering randomness in the material properties, the geometry of plate and loading. The conclusions are based on the effect of the parameters like stacking sequence, fiber volume fraction, temperature, CNT distribution, fiber material and number of CNT on the mean of first and last ply failure loads (FPFL and LPFL) and coefficient of variance (COV) of MWCNTRC plate. Stochastic failure analysis of MWCNTRC plate up to last ply failure by considering patch loading, nonlinearity and FG distribution of CNT is unique in this work.
AMBIGUITY AVERSION AND INDIVIDUAL ADAPTATION TO CLIMATE CHANGE: EVIDENCE FROM A FARMER SURVEY IN NORTHEASTERN THAILAND
Authors: SHIIBA NAGISA , YOKOO HIDE-FUMI , SAENGAVUT VORAVEE , BUMRUNGKIT SIRAPRAPA
Published: June 2022

Understanding the triggers of individual adaptation behavior is critical for empowering those who are highly vulnerable to climate change. This study explores the effect of ambiguity aversion on adaptation behaviors in the context of climate change. We conduct a field survey among 230 rice farmers in northeastern Thailand to examine the association between elicited ambiguity aversion and the implementation of climate change adaptation. We find that ambiguity aversion does not encourage farmers’ adaptation behaviors and can even discourage the uptake of adaptation strategies. The role of ambiguity aversion varies depending on the characteristics of the adaptation strategy: ambiguity-averse farmers are less likely to adopt adaptation strategies that entail shifts from the status-quo. A deliberate approach is needed to understand farmers’ adaptation behaviors outside the laboratory setting and to reduce ambiguity in the results concerning adaptation to increasing climate risk.
Tick Size, Institutional Trading, and Market Making: A Study of the SEC Tick Size Pilot Program
Authors: Gao Xin , Lin Kaitao , Liu Rui
Published: June 2022

Using the 2016 SEC Tick Size Pilot Program, we study the effects of an increase in tick size on institutional trading, market making costs, profitability, and activities. We find that increasing the tick size deters institutional trading participation, as it results in unfavorable stock characteristics, such as greater price impact and depressed share prices. In particular, we show that the implementation of the pilot program creates a substitution effect, which causes mutual funds to migrate from pilot (wider-tick) stocks to control (narrower-tick) peers. Furthermore, we document that widening the tick size increases adverse selection and inventory costs and thus reduces market making profitability, leading to lower market-making activities. Further analysis shows that these adverse effects can be attributed to the trade-at rule that prevents price-matching in non-displaying trading centers, while the quote rule that mandates a minimum quote increment of five cents enriches market makers and promotes liquidity provision. Finally, we show that our results are more pronounced for tick-constrained stocks than for unconstrained ones. Overall, the evidence contradicts the SEC’s intent to use a larger tick size to incentivize market making in small-cap stocks and attract more investors to trade these stocks, and dispraises the “one-size-fits-all” approach undertaken by regulators.
Design and Gene Delivery Application of Polymeric Materials in Cancer Immunotherapy
Authors: Chen Ying , Ke Lingjie , Loh Xian Jun , Wu Yun-Long
Published: June 2022

Immunotherapy has offered an alternative therapy method for cancer patients with metastatic tumors or who are not suitable for surgical resection. Different from traditional surgery, radiotherapy and chemotherapy, immunotherapy mainly restores the activity of the body’s own immune cells silenced in the tumor microenvironment to achieve anticancer therapy. Gene therapy which corrects abnormal expression of immune cells in tumor microenvironment by delivering exogenous genes to specific immune cells, is the most widely studied immunotherapy. Although most available gene delivery vectors are still viral vectors, the further application of viral vectors is still limited by the immunogenicity and mutagenesis. Based on this, cationic polymeric gene vectors with high flexibility, high feasibility, low cost and high safety have been widely used in gene delivery. The structural variability of polymers allows specific chemical modifications to be incorporated into polymer scaffolds to improve their physicochemical properties for more stable loading of genes or more targeted delivery to specific cells. In this review, we have summarized the structural characteristics and application potential in cancer immunotherapy of these polymeric gene vectors based on poly(L-lysine), poly(lactic-co-glycolic acid), polyethyleneimine, poly(amidoamine) and hydrogel system.
Effect of Mn-Based Slurries on Chemical Mechanical Polishing of SiC Substrates
Authors: Zhao Panpan , Yin Tao , Doi Toshiro , Kurokawa Syuhei , Seshimo Kiyoshi , Ye Dongfen , Cai Jianchen
Published: June 2022

High-efficiency and high-quality chemical mechanical polishing (CMP) of silicon carbide (SiC) substrates was achieved using slurries prepared with manganese oxide (MnO2, Mn2O3) particles. Experimental results showed that the oxidation-reduction potential (ORP) and zeta potential of these manganese (Mn)-based slurries decreased with increasing pH. For alkaline pH values (> 7), MnO2 particles were converted into strongly oxidizing MnO4
2− ions that promoted interfacial chemical reactions during CMP, thereby increasing the material removal rate. Observation and analysis of the SiC substrate surface showed that the surface roughness (Ra) reached 1 nm after polishing, but slight surface scratches remained. The binding energy of elemental oxygen (O) and Mn (O1s and Mn2p) indicated that the atoms on the substrate surface underwent an oxidation reaction, which weakened the Si-C molecular bond and thus increased the material removal rate.
Seismic Response and Economic Study of New Light Steel-Wood-Plastic Structure in Rural Yunnan, China
Authors: Jiang Shujiang , Yang Jie , Liu Dewen , Xu Jingran , Li Zhiang , Gao Liang , Yang Yutong , Ma Bingxing
Published: June 2022

A new type of light steel-wood-plastic residential structure in rural has popular in recent years in rural Yunnan, China. The application of light steel, wood, and new plastic materials in practical engineering is gradually increasing due to its advantages of green ecology and waste utilization, and its response characteristics under earthquakes have attracted great attention. In this paper, seismic-resistant models, seismic-isolated models, and seismic-damped models for multistorey light steel-wood-plastic structures were established using the SAP2000 finite element software based on different seismic response methods. The seismic-isolated model is divided into five schemes, namely, LRB400, LRB500, LRB600, high damped, and friction pendulum-isolated bearings, and the seismic-damped model is divided into three schemes, namely, ordinary bracing, soft-steel bracing, and BRB bracing at the same locations around the 2nd floor of the building. Nonlinear time analysis was carried out for the nine schemes, comparing the period, structural interstorey displacement, base shear, top displacement, top acceleration, and economy of the structure under the action of an 8-degree earthquake. Results show that the period of the seismic-isolated system increased by approximately 130% compared to the seismic-resistant system, and the period of the damped system decreased slightly compared to the seismic system, the interstorey displacement, base shear, and top acceleration of both the seismic-isolated system and the damped system were smaller than those of the seismic-resistant system, and the seismic-isolated system decreased by approximately 40% compared to the damped system, and the seismic-isolated system was more effective than the damped system. From the comparison of postearthquake damage cost and full-cycle cost, the economic performance of the seismic-isolated structure is better than that of the damped and seismic-resistant structures. The conclusions of this paper can provide a scientific reference for promoting the use of new light steel-wood-plastic residential buildings.
Study on the Relationship between the Fluidity of Paste in Stope and the Rheological Properties of Paste
Authors: Wang Liang , Qiao DengPan , Xie JinCheng , Wang Jun , Huang Fei
Published: June 2022

Paste should be kept in homogeneous state without segregation or weak segregation during pipeline transportation, which can reduce the occurrence of pipe blockage accidents in engineering application. Only when the paste is homogeneous can the paste have good stope fluidity, and the stope fluidity is also restricted by the geometric size of the stope and other factors. Therefore, it is very important to study the homogeneity of paste and analyze the influence of paste rheological characteristics on stope fluidity. In this paper, it is pointed out that the vertical settling velocity of solid phase materials in paste in the liquid‐phase dense medium is the main factor affecting the homogeneity of paste. Increasing the plastic viscosity and yield stress of the liquid‐phase dense medium is beneficial to increase the drag force of aggregate and then reduce the settling speed of aggregate in the liquid‐phase dense medium. On this basis, the homogeneity of paste can be judged. In the simplified paste flow field, using Cauchy stress equation and flow boundary conditions, the relationship between paste stope flow performance and paste rheological properties was analyzed, and the relationship model between the slope angle of paste flow formation and paste rheological properties was established. Compared with the experimental results, the error of the model results is small, and the slope angle of paste flow can be well predicted.
The Correlation between Children’s Intelligence Quotient and Their Behavior in Dental Setting: A Cross‐Sectional Study
Authors: Khosrozadeh M. , Ghadimi S. , Kazemzadeh Gharghabi M. , Kharrazifard M. J. , Hamrah M. H. , Baghalian A.
Published: June 2022

Children with high intelligence quotient (IQ) are more capable of managing adverse situations. These children may show more cooperation to receive dental treatments. This study assessed the effect of intelligence quotient (IQ) of 5‐10‐year‐old children on their cooperation during dental treatments. Eighty children without previous dental history and in need of pulpotomy and stainless steel crowns in one tooth were selected. A written consent was obtained from the parents, and after the children’s IQ was measured by Raven intelligence test, the treatments were performed and their cooperation level was determined using Frankl’s behavior rating scale with rating 1 to rating 4 (definitely negative, negative, positive, and definitely positive). In this cross‐sectional study, the relationship between IQ and cooperation level was analyzed by one‐way ANOVA test while the effect of age and gender on IQ and cooperation level was studied by ordinal regression test. Out of the total samples, 5% had definitely negative, 16.2% had negative, 56.3% had positive, and 22.5% had definitely positive level of cooperation according to Frankl criteria. There was a significant and positive correlation between IQ and level of cooperation (r = 0.87, p < 0.001). According to the results of the linear regression analysis, to examine the effect of age, sex, and IQ variables on cooperation, children’s age (p value = 0.003) had a positive effect on their cooperation, but gender had no effect on predicting IQ and cooperation level (p value = 0.557). Regarding significant relationship between IQ scores and cooperation level, dentists can predict cooperation in pediatric patients to deliver better treatments and increase patients’ satisfaction.