bluuebunny/crossref_metadata_2025 huggingface dataset:
The anti‐sigma factor MucA is required for viability in Pseudomonas aeruginosa
Authors: Schofield Melissa C. , Rodriguez Daniela Q. , Kidman Amanda A. , Cassin Erin K. , Michaels Lia A. , Campbell Elizabeth A. , Jorth Peter A. , Tseng Boo Shan
Published: April 2021

During decades‐long infections in the cystic fibrosis (CF) airway, Pseudomonas aeruginosa undergoes selection. One bacterial genetic adaptation often observed in CF isolates is mucA mutations. MucA inhibits the sigma factor AlgU. Mutations in mucA lead to AlgU misregulation, resulting in a mucoid phenotype that is associated with poor CF disease outcomes. Due to its ability to be mutated, mucA is assumed to be dispensable for bacterial viability. Here we show that, paradoxically, a portion of mucA is essential in P. aeruginosa. We demonstrate that mucA is no longer required in a strain lacking algU, that mucA alleles encoding for proteins that do not bind to AlgU are insufficient for viability, and that mucA is no longer essential in mutant strains containing AlgU variants with reduced sigma factor activity. Furthermore, we found that overexpression of algU prevents cell growth in the absence of MucA, and that this phenotype can be rescued by the overproduction of RpoD, the housekeeping sigma factor. Together, these results suggest that in the absence of MucA, the inability to regulate AlgU activity results in the loss of bacterial viability. Finally, we speculate that the essentiality of anti‐sigma factors that regulate envelope function may be a widespread phenomenon in bacteria.
A HAT1‐DELLA signaling module regulates trichome initiation and leaf growth by achieving gibberellin homeostasis
Authors: Tan Wenrong , Han Qing , Li Yan , Yang Feng , Li Jiafeng , Li Pengxu , Xu Xiumei , Lin Honghui , Zhang Dawei
Published: April 2021

Trichome initiation and leaf growth are two critical developmental processes in the plant life cycle, which need to be optimized in accordance with developmental stage and immediate surroundings. To a large extent, this optimization is achieved by fine‐tuning of hormonal pathways, including the gibberellin (GA) pathway. However, the mechanism by which plants control GA homeostasis to optimize these two developmental processes is unknown.

Here, we report that HAT1, a HD‐ZIP II transcription factor, negatively regulates GA‐mediated trichome initiation and cotyledon expansion. Both protein and transcript levels indicated that HAT1 was induced by GA, while an increased abundance of HAT1, in turn, was found to suppress GA biosynthesis and signaling, thus forming a regulatory negative feedback loop that controls GA homeostasis to fine‐tune trichome development and cotyledon expansion.

We also found that HAT1 interacts with DELLAs, including GAI and RGA. GAI inhibits both protein stability and the binding activity of HAT1 to its target genes. Overexpression of HAT1 in della5 can completely suppress the enhanced trichome initiation and enlarged cotyledon of della5.

Our findings demonstrate that HAT1 functions as a critical repressor to regulate GA‐mediated trichome initiation and cotyledon growth; in addition, we describe a novel mechanism by which the plant regulates trichome initiation and cotyledon expansion through a HAT1‐DELLA regulatory module under various GA concentrations.
Mycorrhizal associations change root functionality: a 3D modelling study on competitive interactions between plants for light and nutrients
Authors: de Vries Jorad , Evers Jochem B. , Kuyper Thomas W. , van Ruijven Jasper , Mommer Liesje
Published: April 2021

Recent studies show that the variation in root functional traits can be explained by a two‐dimensional trait framework, containing a ‘collaboration’ axis in addition to the classical fast–slow ‘conservation’ axis. This collaboration axis spans from thin and highly branched roots that employ a ‘do‐it‐yourself’ strategy to thick and sparsely branched roots that ‘outsource’ nutrient uptake to symbiotic arbuscular mycorrhizal fungi (AMF).

Here, we explore the functionality of this collaboration axis by quantifying how interactions with AMF change the impact of root traits on plant performance. To this end, we developed a novel functional–structural plant (FSP) modelling approach that simulates plants competing for light and nutrients in the presence or absence of AMF.

Our simulation results support the notion that in the absence of AMF, plants rely on thin, highly branched roots for their nutrient uptake. The presence of AMF, however, promotes thick, unbranched roots as an alternative strategy for uptake of immobile phosphorus, but not for mobile nitrogen.

This provides further support for a root trait framework that accommodates for the interactive effect of roots and AMF. Our modelling study offers unique opportunities to incorporate soil microbial interactions into root functionality as it integrates consequences of belowground trait expression.
Dilthey’s philosophy and methodology of hermeneutics: An approach and contribution to nursing science
Authors: James Dara , Komnenich Pauline
Published: April 2021

The purpose of this article was to examine the historical contribution of Wilhelm Dilthey's approach to the philosophy and methodology of hermeneutics in the demarcated context of nursing science. Dilthey's work made a fundamentally significant, yet ancillary, contribution to nursing science. Organically born from a need to deduce Biblical texts, hermeneutics later developed as a means to understand the truth of another's experience, in literal German language referred to as verstehen. A German‐born empiricist and devout hermeneutic scholar, Dilthey extended the philosophy of hermeneutics to a methodological approach as a way to recapture expressed meaning of human experiences. His directive work paved a procedural pathway to probe the science of human nature while bound to the appropriate sociohistorical context. Hermeneutic methodology provides a phenomenological‐like way to more keenly understand and interpret the whole person. This methodological approach steers a truth‐seeking strategy fixed in meticulous and rigorous inquiry. Dilthey transparently recognized the humble fact that there is no true way to wholly grasp another's experience, an inherent limitation of our human abilities. The current paper posits that hermeneutical understanding verstehen can be paralleled to the concept of empathy in nursing. Understanding and empathy are foundational components to the field of nursing as a caring science. The complex yet invaluable philosophy and methodology of Wilhelm Dilthey's hermeneutics is notably relevant and applicable to nursing science as we strive to care for, treat, and heal patients as whole beings.
Evaluation of postoperative complications for patent ductus arteriosus in extremely‐low‐birthweight infants
Authors: Ishida Shuji , Yamaguchi Ayano , Ooka Mari , Kenmochi Manabu , Nakanishi Hidehiko
Published: April 2021

Background

Patent ductus arteriosus (PDA), which disrupts the hemodynamics early after birth, causes intraventricular hemorrhage and neonatal necrotizing. Unlike medical treatment for hemodynamically significant PDA, there are institutional disparities in the criteria for surgical treatment

Methods

We aimed to clarify the postoperative indications of surgery for hemodynamically significant PDA and the postoperative complications associated with surgery.

Results

Thirty‐six extremely‐low‐birthweight infants (median gestational age 25.2 weeks, median birthweight 699 g) required video‐assisted thoracoscopic surgery for PDA (VATS‐PDA). The treatment indication of VATS‐PDA was resistance to medical treatment in 17 cases, relapsed PDA in 15 cases, and no additional administration of indomethacin because of severe side effects in four cases. Complications with VATS‐PDA occurred in eight of 36 cases. There were three cases of pneumothorax, two of thoracotomy transition, two of pulmonary hemorrhage, and four of post‐ligation cardiac syndrome (PLCS). VATS‐PDA‐related death occurred in two cases due to PLCS. The frequency of four or more administrations of indomethacin, with or without postoperative complications, was 88% vs. 39%, respectively (P = 0.04).

Conclusions

All postoperative deaths were caused by PLCS, which had the highest risk of poor prognosis. VATS‐PDA should be considered for unclosed PDA after one course of indomethacin administration.
Transcript profiling of stress‐responsive genes and metabolic changes during salinity in indica and japonica rice exhibit distinct varietal difference
Authors: Basu Supratim , Roychoudhury Aryadeep
Published: April 2021

In the present study, we carried out comprehensive transcript profiling of diverse genes under salinity (200 mM NaCl) at different time points, accompanied by certain biochemical alterations of the indica (IR‐64 and Pokkali) and japonica (Nipponbare and M‐202) rice. The higher susceptibility of Nipponbare and IR‐64 was reflected by lower relative water content, chlorophyll loss, higher malondialdehyde content, and accumulation of H2O2, and reduced nitrate reductase activity, compared to M‐202 and Pokkali, where such changes were less pronounced. Enhanced levels of anthocyanins and reduced glutathione, together with elevated phenylalanine ammonia lyase activity, mainly conferred protection to Nipponbare and IR‐64, while metabolites like phenolics, flavonoids, proline, and polyamines were more induced in M‐202 and Pokkali. Varietal differences in the expression pattern of diverse groups of genes during different durations (6, 24, and 48 h) of stress were striking. A gene showing early induction for a particular variety exhibited a delayed induction in another variety or a gradually decreased expression with treatment time. Pokkali was clearly identified as the salt‐tolerant genotype among the examined varieties based on increased antioxidant potential and enhanced expression of genes encoding for PAL, CHS, and membrane transporters like SOS3, NHX‐1, and HKT‐1. The results presented in this work provide insight into the complex varying regulation patterns for different genes across the investigated rice varieties in providing salt tolerance and highlights distinct differences in expression patterns between susceptible and tolerant indica and japonica rice.
Assessing the Extreme Loneliness of Immigrant Farmworkers
Authors: Smith‐Appelson Jesse L. , Reynolds John R. , Grzywacz Joseph G.
Published: April 2021

Immigrant farmworkers in the United States are a vulnerable population who often face uncertain legal standing, fewer financial and health‐related resources, and higher exposure to work hazards. This article focuses on the loneliness—the subjective experience of social isolation—of immigrant farmworker communities, analyzes the social patterning of loneliness in this population, and estimates its association with self‐rated health. Data come from interviews with immigrant farmworkers (N = 260) at two sites in the rural Southeast. Immigrant farmworkers report substantially high levels of loneliness and appear to be lonelier than the levels found in a diverse range of other published studies of adults. Older women immigrant farmworkers, those with no formal schooling, and farmworkers experiencing food insecurity are especially lonely, and they stand to benefit most from social service outreach. However, the association between loneliness and self‐rated health is relatively weak.
Connecting engineering design and inquiry cycles: Impact on elementary preservice teachers' engineering efficacy and perspectives toward teaching engineering
Authors: Nesmith Suzanne M. , Cooper Sandi
Published: April 2021

Engineering has become increasingly prominent in science education, with documents such as Next Generation Science Standards detailing the importance of introducing students at all grade levels to science and engineering practices. Yet, many elementary teachers may lack sufficient engineering content and pedagogical knowledge and report feeling unprepared to teach engineering content and processes. To prepare future elementary teachers to teach engineering, two university faculty members in science and mathematics education designed an engineering unit that was incorporated within an elementary science methods course and supported through an elementary mathematics methods course. This unit focused on the engineering design process as well as connections between the work of scientists and engineers; the processes of science, engineering, and mathematics; and the cycles of engineering design and inquiry. The results of the study provide evidence that the unit had a positive influence on the 27 preservice teacher participants’ engineering teaching efficacy, understanding of engineering, and comprehension of the implementation of engineering in the elementary classroom.
Prevalence and associated factors of depressive symptoms among people living with HIV on antiretroviral therapy in Jakarta, Indonesia
Authors: Yunihastuti Evy , Lestari Agusin Regina , Sari Vidya , Jhariah Hidayah Ainum , Wulunggono Wulunggono , Pramukti Hikmat , Shinta Mutiara , Shatri Hamzah , Harjono Karjadi Teguh
Published: April 2021

Objective

We aimed to investigate the prevalence of depressive symptoms among people living with HIV (PLHIV) on antiretroviral therapy (ART) in a large HIV treatment facility in Jakarta, Indonesia, and to assess associated factors.

Methods

The Indonesian version of Beck Depression Inventory‐II was used to assess depressive symptoms of 346 participants visiting the HIV Integrated Clinic Cipto Mangunkusumo hospital between June and November 2018.

Results

Depressive symptoms (BDI‐II score ≥14) were exhibited by 50.9% of participants, with prevalences of mild, moderate and severe depression of 30.4%, 15.6% and 4.9%, respectively. Poisson regression with robust variance analysis indicated that having lower income (aPR = 1.38, 95% CI 1.12–1.63), duration of ART for 1–5 years (aPR = 1.25, 95% CI 1.01–1.54) and same‐sex partnership (aPR = 1.27, 95% CI 1.02–1.58) were positively associated with depressive symptoms. Age, sex and history of using intravenous drugs, and ART‐based regimen were not associated with depressive symptoms.

Conclusions

Depressive symptoms were common among our population despite long‐term ART use and were associated with having low‐income, ART for 1–5 years and same‐sex partnership.
Use of polyamide cable ties during experimental omentectomy in adult horses with histopathological assessment
Authors: Hurcombe Samuel D. , Klein Chelsea E. , Roessner Holly A. , Engiles Julie B. , Hopster Klaus
Published: April 2021

Objective

To report the use of nylon cable ties (NCT) for omentectomy in the horse.

Study design

Experimental study.

Animals

Eight healthy adult horses.

Methods

Horses underwent nylon cable tie (NCT) ligation of the greater omentum after ventral midline celiotomy. The time required to complete the omentectomy was recorded. Horses were recovered for 14 days before repeat celiotomy, adhesions assessment, and histological examination of the omentectomy site using a proposed histologic grading scheme. The total time for omentectomy procedure and histologic score was assessed for normality. Data are expressed as mean ± standard deviation.

Results

NCT ligation provided sufficient hemostasis to complete the omentectomy (28 ± 15 s), without rescue ligation. No gross evidence of intra‐abdominal adhesion or morbidity was associated with the omentectomy site 14 days after surgery. NCT were intact at the site of application, covered with smooth fibrous connective tissue. Adiponecrosis with minimal inflammation and fibrovascular occlusion of omental vessels was present at the surgical site. Mild inflammation was present at the NCT‐tissue interface.

Conclusion

The use of NCT resulted in fast and effective omentectomy in healthy horses without short‐term evidence of inflammatory reaction or intra‐abdominal adhesion.

Clinical significance

The described technique provides an alternative for omentectomy in healthy adult horses.
A specialization inequality for tropical complexes
Authors: Cartwright Dustin
Published: April 2021

We prove a specialization inequality relating the dimension of the complete linear series on a variety to the tropical complex of a regular semistable degeneration. Our result extends Baker's specialization inequality to arbitrary dimension.
Scientific writing within the framework of a microbiology laboratory
Authors: Moreno Mosquera Emilce , Quevedo-Hidalgo Balkys
Published: April 2021

Este artículo aborda las prácticas de escritura en laboratorios, particularmente los problemas recurrentes en la presentación de informes de laboratorio. Se analizan las percepciones de los estudiantes y profesores sobre estos problemas, y se presentan una serie de recomendaciones de apoyo relacionadas con la escritura en este género. Se observaron clases de laboratorio y se tomó una muestra aleatoria cegada de 20 informes. El análisis de esta muestra se centró en las secciones de resultados, discusión y conclusiones que causan las mayores dificultades para los estudiantes. Profesores y estudiantes también fueron entrevistados. Los datos recopilados sugieren que el escenario de laboratorio puede promover la enseñanza de géneros como la presentación de informes y se presta a la presentación y discusión de información e ideas dentro de una comunidad en una disciplina académica.
Should a Vehicle Always Deviate to the Tire Blowout Side?—A New Tire Blowout Model With Toe Angle Effects
Authors: Li Ao , Chen Yan , Du Xinyu , Lin Wen-Chiao
Published: April 2021

As a severe tire failure, tire blowout during driving can significantly threaten vehicle stability and road safety. Tire blowout models were developed in the literature to conclude that a vehicle always deviates to the tire blowout side. However, this conclusion is proved to be inaccurate in this paper, since one important factor was largely ignored in the existing tire blowout models. Toe angle, as a basic and widely applied setup on ground vehicles, can provide preset and symmetric lateral tire forces for normal driving. However, when tire blowout occurs, different toe angle setups can impact vehicle motions in different ways. For the first time, the toe angle is explicitly considered and integrated into a tire blowout model in this paper. For different tire blowout locations, driving maneuvers, and drivetrain configurations, the impacts of different toe angle setups on the variations of tire friction forces and vehicle motions are analyzed. The developed tire blowout model with toe angles is validated through both high-fidelity carsim simulation results and experimental results of a scaled test vehicle. Both simulation and experimental results show that a vehicle may not deviate to the tire blowout side, depending on the toe angle setups and driving maneuvers. Moreover, the experimental results also validate that the proposed tire blowout model can accurately evaluate the tire blowout impacts on vehicle dynamics.
An Energy Efficient Power-Split Hybrid Transmission System to Drive Hydraulic Implements in Construction Machines
Authors: Bertolin Mateus , Vacca Andrea
Published: April 2021

This paper proposes a novel hybrid power-split transmission to drive hydraulic implements in construction machinery. The highly efficient power-split hybrid transmission is combined with displacement-controlled (DC) actuators to eliminate throttling losses within the hydraulic system and achieve higher fuel savings. The architecture design, sizing, and power-management are addressed. Simulation results considering a realistic truck-loading cycle on a mini-excavator demonstrate the feasibility of the idea. A systematic comparison between the proposed system and the previously developed series–parallel hybrid is also carried out. The paper compares engine operation and fuel consumption of the previously mentioned hybrid system with the original nonhybrid load-sensing (LS) machine. It is shown that by implementing an efficient engine operation control, the proposed system can achieve up to 60.2% improvement in fuel consumption when compared to the original machine and consume 11.8% less than the previously developed series–parallel hybrid with DC actuation. Other advantages of the proposed solution include a much steadier engine operation, which open to the possibility of designing an engine for optimal consumption and emissions at a single operating point as well as greatly reduce pollutant emissions. A steadier prime mover operation should also benefit fully electric machines, as the battery would not be stressed with heavy transients.
A Novel Model for Oil–Water Stratified Flow in Horizontal Wells With a Curved Interface Based on Dynamic Contact Angle
Authors: Songyi Guo , Zhiming Wang , Quanshu Zeng
Published: April 2021

During the process of oil production and transportation, oil–water two-phase flow is a common occurrence. Well completion optimization and production design are greatly affected by the prediction accuracy of two-phase flow characteristics. In this paper, a novel model is proposed to predict the influence of interface shape on stratified flow. Dynamic contact angle theory and minimum energy method are introduced to solve the momentum equations with a curved interface and dispersed phase holdup in the lower water layer or the upper oil layer, respectively. When the Eotvos number is lower than ten, the interface shape changes from a flat surface to a curved surface, and the flow area of the upper water layer and the lower oil layer will increase and decrease, respectively. Results show that the dynamic contact angle and pressure gradient are greatly affected by oil superficial velocity, oil viscosity, and pipe diameter. By comparing the prediction with available experiment results, the validity of the model is evaluated. Results show that the novel model has an overall good prediction performance for the pressure gradient, with an average percentage error of 13.12%. While the average percentage error of Liu's model and two-fluid model are 22.89% and 34.98%, respectively. The novel model is a unified model that could be used to solve the problem with a curved/flat interface. It will also promote the oil well production design and horizontal well completion optimization.
Perceptions of Physical Activity Changes Due to COVID-19 Restrictions Among Women in the United Kingdom
Authors: Forsyth Jacky J. , Makay Lorna , Riley Victoria
Published: April 2021

The purpose of the current study was to explore, via interview, how and why women felt their physical activity levels and active lifestyles had been affected by COVID-19. Telephone interviews were conducted with 23 women, aged between 28 and 52 years from a variety of socioeconomic backgrounds in the United Kingdom. Based on reflexive thematic analysis, the perceived reduction in exercise and the increase in sedentary behavior that many of these women experienced were felt to be a result of the physical restrictions imposed through gym and leisure-facility closure, the change in circumstance (both work and home life), the perceived risks associated with exercising during a pandemic, as well as a lack of peer support. In contrast, some women experienced increased opportunity and time to exercise, which they felt benefited their health. For any future pandemic-related restrictions, exercise practitioners should consider promoting exercise with others in a safe environment in order to ensure that women’s healthy exercise and lifestyle behaviors are maintained.
Tim-3 adaptor protein Bat3 is a molecular checkpoint of T cell terminal differentiation and exhaustion
Authors: Zhu Chen , Dixon Karen O. , Newcomer Kathleen , Gu Guangxiang , Xiao Sheng , Zaghouani Sarah , Schramm Markus A. , Wang Chao , Zhang Huiyuan , Goto Kouichiro , Christian Elena , Rangachari Manu , Rosenblatt-Rosen Orit , Okada Hitoshi , Mak Tak , Singer Meromit , Regev Aviv , Kuchroo Vijay
Published: April 2021

Tim-3 adaptor protein Bat3 regulates T cell terminal differentiation and exhaustion in an mTORC2-dependent manner.
Metaform optics: Bridging nanophotonics and freeform optics
Authors: Nikolov Daniel K. , Bauer Aaron , Cheng Fei , Kato Hitoshi , Vamivakas A. Nick , Rolland Jannick P.
Published: April 2021

A miniature imager is demonstrated using a metaform—a rotationally variant optic with an integrated metasurface.
Pandemic-Related Instructor Talk: How New Instructors Supported Students at the Onset of the COVID-19 Pandemic
Authors: Seah Yee Mey , Chang Ana M. , Dabee Smritee , Davidge Brittney , Erickson Jami R. , Olanrewaju Ayokunle O. , Price Rebecca M.
Published: April 2021

At the same time that COVID-19 cases in the United States first began to increase, fellows in a mentored teaching apprenticeship for postdoctoral scientists began to teach undergraduate seminars. The fellows suddenly needed to support students emotionally and switch to online instruction.
Adjusting Expectations: The Impact of 2020 Campus Closures on Advisors’ Approaches to Graduate Student Mentorship
Authors: Koth Zoe , Lane A. Kelly
Published: April 2021

The spring 2020 campus closures due to the COVID-19 pandemic may have posed particular challenges related to the mentorship of science graduate students. In this study, science faculty mentors from one U.S. university report on potential delays to degree completion and their expectations of their mentees during this time.
Instructional Communities of Practice during COVID-19: Social Networks and Their Implications for Resilience†
Authors: Grunspan Daniel Z. , Holt Emily A. , Keenan Susan M.
Published: April 2021

In response to the COVID-19 pandemic, most spring 2020 university courses were abruptly transitioned mid-semester to remote learning. The current study was an exploratory investigation into the interactions among individuals within a single biology department during this transition.
Tunes in the Zoom Room: Remote Learning via Videoconference Discussions of Physiology Songs
†
Authors: Halpin Patricia A. , Crowther Gregory J.
Published: April 2021

As most instruction has been forced online, biology instructors have become acutely aware of the many advantages and limitations of online teaching. Here, we investigate one possible advantage of online education: the ease of allowing remote guest speakers to interact with students in real time.
Triage and Recovery of STEM Laboratory Skills
Authors: Sonbuchner Timothy M. , Mundorff Emily C. , Lee Jacqueline , Wei Sujun , Novick Peter A.
Published: April 2021

The global COVID-19 pandemic left universities with few options but to turn to remote learning. With much effort, STEM courses made this change in modality; however, many laboratory skills, such as measurement and handling equipment, are more difficult to teach in an online learning environment.
Titrating Teaching: An Interdisciplinary Case Study of Online and Face-to-Face Undergraduate Biochemistry Instruction†
Authors: Keppetipola Niroshika , Patchen Terri
Published: April 2021

Although many science education researchers have investigated developing science education at the K–12 levels to meet the needs of underrepresented students in science, far fewer have considered how shifts to online instruction in undergraduate science courses might provide insights into better supporting the achievement of students from diverse backgrounds at the university level. This case study aims to fill this gap by engaging in a reflective interdisciplinary “deep dive” into the instruction of one biochemistry professor at a designated Hispanic-Serving Institution, across two distinct modalities: face-to-face and online.
COVID-360: A Collaborative Effort to Develop a Multidisciplinary Set of Online Resources for Engaging Teaching on the COVID-19 Pandemic
Authors: Del Gaizo Moore Victoria , Scheifele Lisa Z. , Chihade Joseph W. , Provost Joseph J. , Roecklein-Canfield Jennifer A. , Tsotakos Nikolaos , Wolyniak Michael J.
Published: April 2021

The COVID-19 pandemic has challenged undergraduate instructors and students in an unprecedented manner.
Evidence of Carboniferous arc magmatism preserved in the Chicxulub impact structure
Authors: Ross Catherine H. , Stockli Daniel F. , Rasmussen Cornelia , Gulick Sean P.S. , de Graaff Sietze J. , Claeys Philippe , Zhao Jiawei , Xiao Long , Pickersgill Annemarie E. , Schmieder Martin , Kring David A. , Wittmann Axel , Morgan Joanna V.
Published: April 2021

Determining the nature and age of the 200-km-wide Chicxulub impact target rock is an essential step in advancing our understanding of the Maya Block basement. Few age constraints exist for the northern Maya Block crust, specifically the basement underlying the 66 Ma, 200 km-wide Chicxulub impact structure. The International Ocean Discovery Program-International Continental Scientific Drilling Program Expedition 364 core recovered a continuous section of basement rocks from the Chicxulub target rocks, which provides a unique opportunity to illuminate the pre-impact tectonic evolution of a terrane key to the development of the Gulf of Mexico. Sparse published ages for the Maya Block point to Mesoproterozoic, Ediacaran, Ordovician to Devonian crust are consistent with plate reconstruction models. In contrast, granitic basement recovered from the Chicxulub peak ring during Expedition 364 yielded new zircon U-Pb laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) concordant dates clustering around 334 ± 2.3 Ma. Zircon rare earth element (REE) chemistry is consistent with the granitoids having formed in a continental arc setting. Inherited zircon grains fall into three groups: 400–435 Ma, 500–635 Ma, and 940–1400 Ma, which are consistent with the incorporation of Peri-Gondwanan, Pan-African, and Grenvillian crust, respectively. Carboniferous U-Pb ages, trace element compositions, and inherited zircon grains indicate a pre-collisional continental volcanic arc located along the Maya Block's northern margin before NW Gondwana collided with Laurentia. The existence of a continental arc along NW Gondwana suggests southward-directed subduction of Rheic oceanic crust beneath the Maya Block and is similar to evidence for a continental arc along the northern margin of Gondwana that is documented in the Suwannee terrane, Florida, USA, and Coahuila Block of NE México.
Time to desaturation in preterm infants undergoing endotracheal intubation
Authors: Kothari Radhika , Hodgson Kate Alison , Davis Peter G , Thio Marta , Manley Brett James , O'Currain Eoin
Published: April 2021

Background

Neonatal endotracheal intubation is often associated with physiological instability. The Neonatal Resuscitation Program recommends a time-based limit (30 s) for intubation attempts in the delivery room, but there are limited physiological data to support recommendations in the neonatal intensive care unit (NICU). We aimed to determine the time to desaturation after ceasing spontaneous or assisted breathing in preterm infants undergoing elective endotracheal intubation in the NICU.

Methods

Observational study at The Royal Women’s Hospital, Melbourne. A secondary analysis was performed of video recordings of neonates ≤32 weeks’ postmenstrual age undergoing elective intubation. Infants received premedication including atropine, a sedative and muscle relaxant. Apnoeic oxygenation time (AOT) was defined as the time from the last positive pressure or spontaneous breath until desaturation (SpO2 <90%).

Results

Seventy-eight infants were included. The median (IQR) gestational age at birth was 27 (26–29) weeks and birth weight 946 (773–1216) g. All but five neonates desaturated to SpO2 <90% (73/78, 94%). The median (IQR) AOT was 22 (14–32) s. The median (IQR) time from ceasing positive pressure ventilation to desaturation <80% was 35 (24–44) s and to desaturation <60% was 56 (42–68) s. No episodes of bradycardia were seen.

Conclusions

This is the first study to report AOT in preterm infants. During intubation of preterm infants in the NICU, desaturation occurs quickly after cessation of positive pressure ventilation. These data are important for the development of clinical guidelines for neonatal intubation.

Trial registration number

ACTRN12614000709640
Comparative analysis of immunosuppressive therapies for myelin oligodendrocyte glycoprotein antibody-associated optic neuritis: a cohort study
Authors: Xie Lindan , Zhou Huanfen , Song Honglu , Sun Mingming , Yang Mo , Lai Ying Meng , Xu Quangang , Wei Shihui
Published: April 2021

Aims

The optimal immunosuppressive therapy (IST) in patients with myelin oligodendrocyte glycoprotein antibody-associated optic neuritis (MOG-ON) remains uncertain. This study aimed to observe the disease course of MOG-ON and evaluate the therapeutic efficacy and tolerability of conventional immunosuppressants through Chinese cohort analysis.

Methods

This bidirectional cohort study included 121 patients with MOG-ON between January 2015 and December 2018. The clinical features and annualised relapse rate (ARR) of patients with and without IST were analysed.

Results

The median age at onset was 17.5 years, and the sex ratio (F:M) was 1.24. Of 121 patients, 77 patients relapsed and 61 patients were younger than 18 years at disease onset. The overall median ARR of 63 patients in the non-IST group was 0.5, with 46.0% patients showing relapse at a median follow-up of 33.5 months. In the IST group, the ARR decreased from 1.75 pre-IST to 0.00 post-IST in 53 patients who received IST exceeding 6 months, with 20.8% patients showing relapse at a median follow-up of 23.8 months. The relapse rates of patients treated with rituximab (RTX) and mycophenolate mofetil (MMF) were not statistically different, but the rate of discontinuation was significantly lower in the RTX-treated group (18.2% vs 57.7%, p=0.0017).

Conclusion

This study provides Class III evidence that both MMF and RTX may lower disease activity in patients with MOG-ON, and RTX showed better tolerability than MMF. However, observation after a single attack remains a good option because less than half of patients not on treatment suffered a relapse.
Corneal confocal microscopy identifies a reduction in corneal keratocyte density and sub-basal nerves in children with type 1 diabetes mellitus
Authors: Gad Hoda , Al-Jarrah Bara , Saraswathi Saras , Mohamed Sara , Kalteniece Alise , Petropoulos Ioannis N , Khan Adnan , Ponirakis Georgios , Singh Parul , Khodor Souhaila Al , Elawad Mamoun , Almasri Wesam , Hendaus Mohamed A , Akobeng Anthony K , Hussain Khalid , Malik Rayaz A
Published: April 2021

Purpose

To assess whether alterations in stromal keratocyte density are related to loss of corneal nerve fibres in children with type 1 diabetes mellitus (T1DM).

Methods

Twenty participants with T1DM and 20 age-matched healthy controls underwent corneal confocal microscopy. Corneal sub-basal nerve morphology and corneal keratocyte density (KD) were quantified.

Results

Corneal nerve fibre density (CNFD) (p<0.001), corneal nerve branch density (p<0.001), corneal nerve fibre length (CNFL) (p<0.001) and inferior whorl length (IWL) (p<0.001) were lower in children with T1DM compared with healthy controls. Anterior (p<0.03) and mid (p=0.03) stromal KDs were lower with no difference in posterior KD (PKD) in children with T1DM compared with controls. Age, duration of diabetes, height, weight and body mass index did not correlate with anterior (AKD), mid (MKD) or PKD. Inverse correlations were found between glycated haemoglobin and PKD (r=−0.539, p=0.026), bilirubin with MKD (r=−0.540, p=0.025) and PKD (r=−0.531, p=0.028) and 25-hydroxycholecalciferol with MKD (r=−0.583, p=0.018). CNFD, CNFL and IWL did not correlate with AKD, MKD or PKD.

Conclusion

This study demonstrates a reduction in corneal nerves and anterior and mid stromal KD in children with T1DM, but no correlation between corneal nerve and keratocyte cell loss.
Effect of COVID-19 pandemic on glaucoma surgical practices in the UK
Authors: Holland Lee Joseph , Kirwan James F , Mercieca Karl J
Published: April 2021

Background/Aim

The aim of the study was to examine the effect of the COVID-19 pandemic on glaucoma surgical practices within the UK.

Methods

A cross-sectional online survey was distributed to all consultant glaucoma specialists who are on the UK and Eire Glaucoma Society contact list. Participants were asked specific questions regarding preferences in glaucoma surgical practices and whether these had changed subsequent to the onset of the COVID-19 pandemic.

Results

Trabeculectomy was the procedure of choice for 61 (87%) glaucoma specialists. A total of 51 (73%) respondents reported performing minimally invasive glaucoma surgery (MIGS) procedures before the COVID-19 pandemic. The most commonly performed MIGS procedure was the iStent inject (51%), followed by XEN 45 (36%) and Preserflo (17%). Forty-three (61%) respondents reported modifying their glaucoma surgery practice subsequent to the onset of the COVID-19 pandemic. Of the glaucoma specialists who modified their surgical practices, 21 (43%) specifically reduced the number of trabeculectomies performed. In combination, diode laser (both micropulse and conventional trans-scleral cyclodiode) was the most common alternative procedure. Glaucoma drainage devices, deep sclerectomy and Preserflo were also commonly chosen alternatives.

Conclusion

Although trabeculectomy remains the most commonly performed established glaucoma surgery, it is being performed with reduced frequency during the COVID-19 pandemic due to the number of postoperative visits and procedures required. Alternatives such as conventional and micropulse diode laser, glaucoma drainage devices, deep sclerectomy and Preserflo appear to be the favoured alternative procedures.
Prevalence and risk factors of frailty among people in rural areas: a systematic review and meta-analysis
Authors: Xu Rui , Li Qiufang , Guo Feifei , Zhao Maoni , Zhang Luyao
Published: April 2021

Objective

Older people in rural areas are possibly more frail due to the limited medical resources and lower socioeconomic status. Given the negative healthy outcomes caused by frailty, knowing the epidemiology of frailty in rural areas is of great importance. We tried to synthesise the existing evidences for the prevalence and risk factors of frailty in rural areas.

Design

A systematic review and meta-analysis.

Data sources

PubMed, Embase, MEDLINE, Cochrane Library, Web of Science and Scopus were used to identify the articles from inception to 30 April 2019.

Eligibility criteria

Observational studies providing cross-sectional data on the prevalence of frailty in rural elderly were extracted.

Data extraction and synthesis

Two independent investigators selected studies, extracted data and assessed the methodological quality of included studies. The pool prevalence of frailty was calculated by the random effects model and the OR and 95% CI were used to calculate the risk factors.

Results

The literature search yielded 2219 articles, of which 23 met the study criteria and were included in this analysis. The pooled prevalence of frailty and pre-frailty were 18% (95% CI 15% to 21%, I2=98.5%, p<0.001) and 50% (95% CI 45% to 56%, I2=98.4%, p<0.001), respectively. The pooled frailty prevalence was 15% for the Fried Phenotype, 18% for the Frailty Index and 23% for other criteria. The pooled prevalence of frailty was 17% for males and 26% for females. The pooled prevalence of frailty was 17% in developing countries and 23% in developed countries. Age, cognitive impairment, depressive symptom, risk of malnutrition, activity of daily living (ADL) disability and poor self-perception of health were associated with frailty. There was no publication bias.

Conclusions

Frailty influences almost one in five older people in rural areas, and increasing age, cognitive impairment, depressive symptom, risk of malnutrition, ADL disability and poor self-perception of health were all risk factors for frailty. We should be cautious about the research results due to the heterogeneity between studies.
Different pedagogies for acquisition of knowledge and skill: a systematic review and network meta-analysis
Authors: Jhou Hong-Jie , Ou-Yang Liang-Jun , Lin Ming-Hsun , Chen Po-Huang , Ho Ching-Liang , Lee Cho-Hao
Published: April 2021

Background

This network meta-analysis aimed to assess the efficacy of different educational methods for healthcare professionals.

Methods

A systematic literature search was conducted to identify relevant randomised controlled trials. The standardised mean difference (SMD) with 95% CI was estimated using network meta-analysis for knowledge acquisition and skill performance, and ranked the effects of different educational methods using the surface under the cumulative ranking area (SCURA) technique.

Results

Fifty-five randomised controlled trials including of 4292 participants were identified. Compared with no intervention, the results demonstrated all education methods achieved significant improvements in knowledge acquisition (SMD 1.73–2.66). Only education methods involving high fidelity virtual patient simulation reported significantly better skill performance (SMD 1.25–1.81). High fidelity virtual patient simulation plus self-directed learning was the most effective educational method both in terms of knowledge acquisition (SMD 2.66, 95% CI 1.4 to 4.12, SCURA 0.78) and skill performance (SMD 1.81, 95% CI 0.42 to 3.2, SCURA 0.89).

Conclusions

Our study demonstrates all educational methods have positive effects on knowledge acquisition, but education methods involving high fidelity virtual patient simulation are better at improving skill performance than other methods.
Functional electrical stimulation‐assisted cycle ergometry-based progressive mobility programme for mechanically ventilated patients: randomised controlled trial with 6 months follow-up
Authors: Waldauf Petr , Hrušková Natália , Blahutova Barbora , Gojda Jan , Urban Tomáš , Krajčová Adéla , Fric Michal , Jiroutková Kateřina , Řasová Kamila , Duška František
Published: April 2021

Purpose

Functional electrical stimulation-assisted cycle ergometry (FESCE) enables in-bed leg exercise independently of patients’ volition. We hypothesised that early use of FESCE-based progressive mobility programme improves physical function in survivors of critical care after 6 months.

Methods

We enrolled mechanically ventilated adults estimated to need >7 days of intensive care unit (ICU) stay into an assessor-blinded single centre randomised controlled trial to receive either FESCE-based protocolised or standard rehabilitation that continued up to day 28 or ICU discharge.

Results

We randomised in 1:1 ratio 150 patients (age 61±15 years, Acute Physiology and Chronic Health Evaluation II 21±7) at a median of 21 (IQR 19–43) hours after admission to ICU. Mean rehabilitation duration of rehabilitation delivered to intervention versus control group was 82 (IQR 66–97) versus 53 (IQR 50–57) min per treatment day, p<0.001. At 6 months 42 (56%) and 46 (61%) patients in interventional and control groups, respectively, were alive and available to follow-up (81.5% of prespecified sample size). Their Physical Component Summary of SF-36 (primary outcome) was not different at 6 months (50 (IQR 21–69) vs 49 (IQR 26–77); p=0.26). At ICU discharge, there were no differences in the ICU length of stay, functional performance, rectus femoris cross-sectional diameter or muscle power despite the daily nitrogen balance was being 0.6 (95% CI 0.2 to 1.0; p=0.004) gN/m
2
less negative in the intervention group.

Conclusion

Early delivery of FESCE-based protocolised rehabilitation to ICU patients does not improve physical functioning at 6 months in survivors.

Trial registration number

NCT02864745
.
Tomato growth, yield, and quality response to mixed chemical–organic fertilizers and grafting treatments in a high tunnel environment
Authors: Buajaila Fairuz , Cowan Jeremy S. , Inglis Debra , Carpenter-Boggs Lynne , Miles Carol
Published: April 2021

Tomato (Solanum lycopersicum L.) is a major vegetable crop world-wide and grown in high tunnels in many regions. This study investigates the use of two fertilizer sources, chemical and integrated (composted poultry manure plus urea) fertilizers, and grafting on growth, nitrate-N content, yield, and fruit quality of tomato grown in high tunnels in northwestern Washington. Grafting treatments consisted of ‘Panzer’ tomato grafted on one of three tomato rootstocks ‘Estamino’, Maxifort’, ‘DRO138TX’, or non-grafted (control). Application of chemical fertilizer increased number of leaves per plant, plant height, and cumulative fresh biomass of pruned suckers relative to tomato plants grown with the integrated fertilizer treatment. Grafted tomato plants had greater plant growth than non-grafted plants throughout the growing season. There was no significant difference between fertilizer treatments on nitrate-N concentration in plant tissue or fresh petiole sap; however, grafted plants contained higher levels of nitrate-N than non-grafted plants. Total and marketable fruit weight and number did not differ due to fertilizer source, but total and marketable fruit weight was higher for grafted plants than for non-grafted plants in 2016. There was no significant effect due to fertilizer source on fruit firmness, water content, pH, titratable acidity, and β-carotene; however, total soluble solids (TSS) and lycopene content were higher for fruit grown with integrated fertilizer in 2016. Grafting enhanced water content of tomato fruit in 2015, and TSS (°Brix) in 2016.
Combined theoretical study of the $$D^+ \rightarrow \pi ^+ \eta \eta $$ and $$D^+ \rightarrow \pi ^+ \pi ^0 \eta $$ reactions
Authors: Ikeno Natsumi , Bayar Melahat , Oset Eulogio
Published: April 2021

We study the$$D^+ \rightarrow \pi ^+ \eta \eta $$D+→π+ηηand$$D^+ \rightarrow \pi ^+ \pi ^0 \eta $$D+→π+π0ηreactions, which are single Cabibbo suppressed and can proceed both through internal and external emission. The primary mechanisms at quark level are considered, followed by hadronization to produce three mesons in the$$D^+$$D+decay, and after that the final state interaction of these mesons leads to the production of the$$a_0(980)$$a0(980)resonance, seen in the$$\pi ^+ \eta $$π+η,$$\pi ^0 \eta $$π0ηmass distributions. The theory has three unknown parameters to determine the shape of the distributions and the ratio between the$$D^+ \rightarrow \pi ^+ \eta \eta $$D+→π+ηηand$$D^+ \rightarrow \pi ^+ \pi ^0 \eta $$D+→π+π0ηrates. This ratio restricts much the sets of parameters but there is still much freedom leading to different shapes in the mass distributions. We call for a measurement of these mass distributions that will settle the reaction mechanism, while at the same time provide relevant information on the way that the$$a_0(980)$$a0(980)resonance is produced in the reactions.
Hydrodynamic limit of a coupled Cucker–Smale system with strong and weak internal variable relaxation
Authors: Kim Jeongho , Poyato David , Soler Juan
Published: April 2021

In this paper, we present the hydrodynamic limit of a multiscale system describing the dynamics of two populations of agents with alignment interactions and the effect of an internal variable. It consists of a kinetic equation coupled with an Euler-type equation inspired by the thermomechanical Cucker–Smale (TCS) model. We propose a novel drag force for the fluid-particle interaction reminiscent of Stokes’ law. While the macroscopic species is regarded as a self-organized background fluid that affects the kinetic species, the latter is assumed sparse and does not affect the macroscopic dynamics. We propose two hyperbolic scalings, in terms of a strong and weak relaxation regime of the internal variable towards the background population. Under each regime, we prove the rigorous hydrodynamic limit towards a coupled system composed of two Euler-type equations. Inertial effects of momentum and internal variable in the kinetic species disappear for strong relaxation, whereas a nontrivial dynamics for the internal variable appears for weak relaxation. Our analysis covers both the case of Lipschitz and weakly singular influence functions.