bluuebunny/crossref_metadata_2025 huggingface dataset:
Escherichia coli small heat shock protein IbpA is an aggregation‐sensor that self‐regulates its own expression at posttranscriptional levels
Authors: Miwa Tsukumi , Chadani Yuhei , Taguchi Hideki
Published: September 2020

Aggregation is an inherent characteristic of proteins. Risk management strategies to reduce aggregation are critical for cells to survive upon stresses that induce aggregation. Cells cope with protein aggregation by utilizing a variety of chaperones, as exemplified by heat‐shock proteins (Hsps). The heat stress‐induced expression of IbpA and IbpB, small Hsps in Escherichia coli, is regulated by the σ32 heat‐shock transcriptional regulator and the temperature‐dependent translational regulation via mRNA heat fluctuation. We found that, even without heat stress, either the expression of aggregation‐prone proteins or the ibpA gene deletion profoundly increases the expression of IbpA. Combined with other evidence, we propose novel mechanisms for the regulation of the small Hsps expression. Oligomeric IbpA self‐represses the ibpA/ibpB translation, and mediates its own mRNA degradation, but the self‐repression is relieved by sequestration of IbpA into the protein aggregates. Thus, the function of IbpA as a chaperone to form co‐aggregates is harnessed as an aggregation sensor to tightly regulate the IbpA level. Since the excessive preemptive supply of IbpA in advance of stress is harmful, the prodigious and rapid expression of IbpA/IbpB on demand is necessary for IbpA to function as a first line of defense against acute protein aggregation.
Challenge of managing opposing rhythms in a mother and fetus
Authors: Chaudhry‐Waterman Nadia , Kumar Vineet , Karr Sharon , Fitzpatrick Andrew , Cohen Mitchell I.
Published: September 2020

Introduction

We report a case of a fetus with complex congenital heart disease and supraventricular tachycardia in the setting of maternal high grade atrioventricular block at 26 weeks’ gestation.

Methods and results

Electroanatomic mapping allowed successful implantation of a permanent pacemaker to provide adequate back‐up pacing in the mother with zero radiation exposure, thus allowing safe delivery of transplacental anti‐arrhythmic medications to reduce the fetal arrhythmia burden and optimize the fetal ventricular rate.

Conclusion

This is the first reported case of using electroanatomic mapping, with zero fluoroscopy use, for pacemaker lead placement and for a novel indication.
Etiology of syncope in patients with preexisting atrioventricular conduction disorders
Authors: Mitro Peter , Šimurda Miloš , Lazúrová Zora , Jakubová Marta
Published: September 2020

Background

The discussion about the feasibility of empiric pacemaker implantation in patients with preexisting atrioventricular (AV) conduction disorders continues. The aim of the study was to determine the etiology of syncope and the need for pacemaker insertion in patients with AV conduction impairment using implantable loop recorder (ILR).

Methods

ILR was implanted after negative diagnostic workup in 37 patients with syncope (24 men, 13 women, age 72 ± 10 years) and preexisting impairment of AV conduction. First‐degree AV block (AVB I) was present in 26 patients, and bundle branch block (BBB) in 17 patients.

Results

ILR‐based diagnosis was made in 28 patients (75%)—sinus arrest in 13 patients, complete AVB in 10 patients, and vasodepressor syncope in five patients. In patients with preexisting BBB, sinus arrest occurred during ILR monitoring significantly more frequently than in patients without BBB (53% vs 20%, P = .03). Complete AVB was significantly less common in patients with preexisting BBB than in patients without BBB (12% vs 40%, P = .04). On multivariate regression analysis, the only independent predictor of AVB occurrence during ILR monitoring was preexisting AVB I (P = .03). The only independent predictor of sinus arrest during ILR monitoring was preexisting BBB (P = .03).

Conclusions

In patients with preexisting AV conduction disorders, prevailing syncopal mechanism during ILR monitoring was asystole. However, sinus arrest occurred more often than complete AVB and was predicted by preexisting BBB. Preexisting AVB was a predictor of complete AVB during ILR monitoring.
Preventing inadvertent Endobronchial intubation: Upper incisor to manubriosternal joint length as a predictor of airway length in children
Authors: Jain Apoorv , Wadhwa Bharti , Saxena Kirti Nath
Published: September 2020

Background

Malpositioning of the endotracheal tube within the airway can lead to serious complications. The estimated insertion depth of the endotracheal tube should be accurate and reliable.

Aims and objectives

To study whether the upper incisor‐manubriosternal joint length in the extended head position can be used as a predictor of airway length to guide the depth of insertion of endotracheal tube in children and to evaluate the correlation of upper incisor‐manubriosternal joint length with the upper incisor‐carina length in the neutral head position, in Indian pediatric population.

Materials and methods

After induction of anesthesia, upper incisor‐manubriosternal joint length was measured using a flexible metallic tape. Endotracheal tube was inserted and secured in the midline over the upper incisors. The degree of the maximum head extension was recorded with a goniometer, and the upper incisor‐carina length was measured with the help of a fiberoptic bronchoscope.

Results

Analysis revealed a positive correlation between upper incisor‐carina length and upper incisor‐manubriosternal joint length (R = .456, R2 = .208, P = .000) and also between upper incisor‐carina length and the height of the patient (R = .528, R2 = .279, P‐value .000). The degree of maximum head extension did not influence the upper incisor‐carina length and the upper incisor‐manubriosternal joint length relationship.

Conclusion

The upper incisor‐carina length shows a positive correlation with the patient's upper incisor‐manubriosternal joint length and the patient's standing height, while the degree of maximum head extension has no significant bearing on this relationship. The upper incisor‐manubriosternal joint length can be used as a predictor of airway length and the depth of insertion of endotracheal tube in children.
Female and male fitness of a sexually deceptive orchid with a narrow distribution area: from phenotypic traits to spatial distribution patterns
Authors: Borràs J. , Cursach J.
Published: September 2020

The Orchidaceae family presents one of the most extravagant pollination mechanisms: deception. While many studies on reproductive success have been performed on food‐deception orchids, less have been performed on sexually deceptive orchids. Here, we focused on Ophrys balearica P. Delforge, an endemic orchid of the Balearic Islands, to study its reproductive ecology, the spatio‐temporal variation of its reproductive success and the individual (floral display and geospatial position) and population parameters (patch size, shape and density) that affect its reproductive success.

We performed hand‐pollination experiments, along with the recording of floral display parameters and GPS position of over 1,100 individuals from seven populations in two consecutive years. We applied, for the first time, GIS tools to analyse the effects of individual’s position within the population on the reproductive success. Reproductive success was measured both in male (removed pollinia) and female (fruit set) fitness.

The results confirm that this species is pollinator‐dependent and mostly allogamous, but also self‐compatible. This species showed high values for the cumulative inbreeding depression index and high pollen limitation. Male fitness was almost equal to female fitness between years and populations, and reproductive success exhibited huge spatio‐temporal variation.

Although we did not find strong correlations between floral display and reproductive success, patches with low‐plant density and individuals in the external portion of the population showed significantly higher plant fitness. These findings must be considered in conservation actions for endangered orchid species, especially considering that most orchids are strongly dependent on pollinators for their species’ fitness.
Using ectomycorrhizae to improve the restoration of Neotropical coastal zones
Authors: Weidlich Emanuela W. A. , Mioto Paulo T. , Furtado Ariadne N. M. , Ferst Lara M. , Ernzen João P. , Neves Maria A.
Published: September 2020

As restoration ecology begins to engage more formally with the role of belowground interactions, we note that there is an even greater gap in knowledge of the role ectomycorrhizae (ECMs) have in ecological restoration in the Neotropical region. Even though there are a few records of ECMs in the Neotropics not much is known about their function. Here we highlight the underestimated importance of ECMs in Neotropical coastal zones, discuss how we could use the vegetation on the coast of the Atlantic Forest, called restinga, as a model to investigate tropical ECMs, and explore further possibilities that can be used in restoration projects.
Rapid restoration of belowground structure and fauna of a seagrass habitat
Authors: Tanner Jason E. , McSkimming Chloe , Russell Bayden D. , Connell Sean D.
Published: September 2020

Seagrass meadows are habitat for an abundance and diversity of animal life, and their continuing global loss has focused effort on their restoration. This restoration not only aims to re‐establish the structure of the seagrass, but also to restore its function, particularly as habitat. The success of seagrass restoration is typically measured by the recovery of aboveground structure, but this ignores the important role of the belowground component of seagrass ecosystems, which may not recover at the same rate, and is equally important for faunal communities. We quantify infaunal communities (abundance, richness, and composition) within expanding plots of restored seagrass, and relate their change to the recovery of belowground seagrass biomass and sediment properties. We found that infaunal abundance and composition converged on that found in natural seagrass within 2 years, while the overall infaunal richness was not affected by habitat. The carbon content of surface sediments also recovered within 2 years, although recovery of belowground biomass and sediment grain size took 4 to 6 years. These results suggest that the structure of recovering seagrass habitats may not need to attain that of natural meadows before they support infauna that is comparable to natural communities. This pace and effectiveness of recovery provides some optimism for future seagrass restoration.
Spatio‐temporal dynamics of Aedes aegypti and Aedes albopictus oviposition in an urban area of northeastern Brazil
Authors: Moura Márcia Cristina Bernardo de Melo , de Oliveira Josinaldo Vidal , Pedreira Rodrigo Moreira , Tavares Alessandre de Medeiros , de Souza Talita Araujo , de Lima Kenio Costa , Barbosa Isabelle Ribeiro
Published: September 2020

Objective

The objective of this study was to analyse abundance and spatial distribution of Aedes aegypti and Aedes albopictus oviposition in the city of Natal‐RN, 2016 to 2018.

Methods

Three hundred and seven oviposition traps were installed covered the whole city and were monitored weekly from January 2016 to December 2018. To verify the abundance of the vector based on its location, the formation of oviposition clusters was studied using the Kernel statistics. Egg Density Index (EDI) and Oviposition Positivity Index (OPI) values were calculated.

Results

Temperature and humidity presented weak and very weak correlation, respectively, with the oviposition indicators. The median of oviposition positivity index (OPI) was 60.5%, and the egg density index (EDI) was 45.4 eggs/trap. The OPI (71.1%) was higher in the second quarter of the year. The areas with the most persistent oviposition are located in a continuous strip that extends from the extreme of the northern district and extends along the western district of the city. Also noteworthy is the proximity to the strategic points.

Conclusion

The spatio‐temporal distribution of oviposition revealed that there is spatial segregation and marked seasonality. Therefore, this study highlights the importance of maintaining surveillance targeting and control strategies focused on these areas, especially during the most important period of the year.
Quantification of axonal ingrowth and functional recovery in a myocutaneous flap model in rats with strong clinical implications
Authors: Xie Yun , Fang Fang , Su Ping , Xiao Jiting , Zheng Haibo , Zhuang Yuehong
Published: September 2020

The process of reinnervation, an important component of functional restoration after flap transfer, is understudied, making it necessary to carry out a further investigation for delineation of the exact timeline. Seventy‐six Sprague‐Dawley rats were used as the experimental animals. An anatomic study was first conducted to clarify the pattern of nerve distribution in the dorsal skin of 16 rats. Afterward, a myocutaneous flap was harvested on the right flanks of 40 rats, which were then assigned into seven time points. At each time point, skin samples were harvested and immunofluorescent staining was performed using α‐Bungarotoxin, and antibodies against NF‐200, p75, α‐SMA, and TH. One‐way analysis of variance was adopted for comparison of nerve density after surgery. For evaluation of functional return, cutaneous trunci muscle reflex (CTMr) test was performed on 10 additional rats, and the Chi‐square test was used for comparison of reflex intensity among six time points after surgery. The outcomes revealed that the cutaneous branches from the intercostal nerves and the dorsothoracic nerve from the brachial plexus could be found entering the dorsal skin, distributed in the skin proper and the panniculus carnosus, respectively. After flap surgery, full spontaneous reinnervation of the skin proper and vessels within the flaps could be achieved at day 180. However, if the stumps of cutaneous branches of the intercostal nerves were damaged, the nerve density in the skin proper underwent a 2/3 decline. The panniculus carnosus in the cranial part had a much better reinnervation than that in the caudal part. The CTMr test showed that the flap could regain most of its sensate and motor activity. Our study shows that strong spontaneous reinnervation could be expected after flap surgery. The pattern of the original nerve distribution in both the recipient and donor sites may have a big impact on the reinnervation of the flap.
ELECTROSPUN STRONTIUM CROSS-LINKED SULFONATED POLY (ETHER ETHER KETONE) SPEEK NANOFIBER FOR PROTON EXCHANGE MEMBRANE FUEL CELL
Authors: Engku Indong Engku Safiah , Ahmad Sekak Khairunnadim
Published: September 2020

Strontium (Sr) cross-linked nanofibrous membranes of sulfonated polyether ether ketone (SPEEK) were successfully prepared using the electrospinning technique. Metal-polymer physical cross-linked has been proposed as a way to improve the mechanical and chemical stabilities of the electrospun SPEEK membrane which we found in this finding can help to reduced water uptake compared with the non-crosslinked membrane. Physical cross-linked of Sr-SPEEK membranes were fabricated by immersion process which were than electrospun into nanofibrous membranes. The morphologies of electrospun Sr-SPEEK membrane, fabricated under different concentrations of Sr were presented which show up to 6% concentration of Strontium was able to be electrospun. On the electrical properties of the electrospun membrane, conductivity for the sample with 6% Sr weight percentage has given 0.188 S/cm which is about 80% higher than the film cast Nafion-117 at 80˚C as cited before. This particular result is a hallmark of the studies as it shows that a combination of nanostructured with crosslink is proven to work in favor of producing proton exchange membrane fuel cell (PEMFC) which performed much better than Nafion based membrane.
TISSUE OXYGEN LEVEL IN ACUTE AND CHRONIC WOUND: A COMPARISON STUDY
Authors: Philimon Sheena P. , Huong Audrey K. C. , Ngu Xavier T. I.
Published: September 2020

Adequate oxygen supply to granulating tissue and its surroundings is considered as an elementary factor to render an optimum condition for proper wound healing. This paper focused on comparing the quantitative mean of transcutaneous oxygen saturation (StO2) between acute superficial wounds and chronic diabetic wounds in a randomized clinical study. A multispectral imaging system was employed for in-vivo measurement of wound StO2 across a visible wavelength range of  nm. Processed StO2 maps of wounds using a reconstructed mathematical model revealed a mean StO2 of  and , respectively, in acute and chronic wounds. The statistical test on the difference in the values between these two groups of wounds was shown to be statistically significant (). These crucial findings contribute to the existing knowledge on the StO2 range and its variation in different wound conditions. In conclusion, the proposed multispectral imaging system is able to produce clinical information of wound oxygenation level for a better understanding of the obligatory role of oxygen as a key determinant in healing outcomes.
Additional in‐series compliance does not affect the length dependence of activation in rat medial gastrocnemius
Authors: MacDougall Keenan B. , Kristensen Anders M. , MacIntosh Brian R.
Published: September 2020

New Findings

What is the central question of this study?

The length dependence of activation (LDA) is typically explained by a length‐dependent increase in calcium sensitivity, but recently calcium‐independent mechanisms have been suggested: does active muscle shortening provided by a compliant in‐series component impact the muscle length at which force output is maximized, thus contributing to LDA?

What is the main finding and its importance?

Using an in situ rat medial gastrocnemius set‐up and varying the magnitude of muscle shortening via an artificial compliant series‐elastic component, we were unable to observe any change in optimal length between conditions, contrary to some previous findings. More research is therefore required to explain these discrepancies.

The force–length relationship dictates the amount of force a muscle can produce as a function of its length, during maximal isometric contractions. When activation is submaximal, it has been shown that the length at which force production is highest (the optimal length) is longer. This is typically explained by a length‐dependent increase in Ca2+ sensitivity, known as the ‘length dependence of activation’. Recent reports have implicated shortening against in‐series compliance to be a potential factor in the observed optimal length (L0) of muscle, via the phenomenon of shortening‐induced force depression (a phenomenon which describes the relative reduction in muscle force when a muscle is actively shortening to a given length compared to contracting isometrically at that same length). In the current study, rat medial gastrocnemius was stimulated with single and triple pulses (200 Hz) over a range of lengths, both with and without additional in‐series compliance provided by a small piece of silicon tubing in series with the muscle, which allowed greater fascicle shortening upon activation. Fascicle length was measured using sonomicrometry crystals, and peak force (Fpeak) and L0 were estimated by curve‐fitting of the force–length data. The additional in‐series compliance significantly reduced Fpeak by approximately 14% and 25% for the single and triple pulses, respectively (P = 0.003, P < 0.001), yet L0 remained unchanged (P = 0.405), suggesting that in our model, shortening against in‐series compliance does not affect L0. We offer potential explanations for the discrepancies seen and discuss whether the velocity of shortening may have a role in the length dependence of force.
A Hybrid Numerical-Experimental Method for Determining Thermal Conductivities
Authors: Evangelakis G. A. , Lagaris I. E. , Papageorgiou D. G. , Prouskas K. , Zisopoulou A. E.
Published: September 2020

Determining the thermal conductivity of a material from temperature measurements in a cooling or heating process belongs to the class of inverse problems. In this article, we present a method for a simple experimental setup, consisting of a glass tube containing the material under investigation, two thermistors for temperature monitoring (one at the central axis and the other attached on the outer surface of the tube), and a water heat bath maintained at a desired temperature. We solve the direct problem, i.e., the transient heat conduction equation, treating the thermal conductivity as a parameter whose value is determined by minimizing the difference between the calculated and the experimentally measured temperatures. The method is based on the numerical solution of the one-dimensional transient heat conduction equation in cylindrical coordinates that accurately describes the temperature evolution of a material in a narrow, long glass tube. The technique has been validated by applying it to the lauric and capric acids, whose thermal conductivities are accurately known and therefore it could be a valuable tool for the determination of the thermal properties of phase change materials suitable for thermal storage applications.
An Experimental Investigation of Constrained Melting Heat Transfer of Nano-Enhanced Phase Change Materials in a Horizontal Cylindrical Capsule Using Thermochromic Liquid Crystal Thermography
Authors: Hu Nan , Li Zi-Rui , Zhang Run-Hui , Liu Jia , Fan Li-Wu
Published: September 2020

The constrained melting of nano-enhanced phase change materials (NePCM) in a horizontal cylindrical capsule was investigated via the utilization of thermochromic liquid crystal (TLC) technique for tracking the invisible phase interfaces. A parametric study was carried out by varying both the loading of NePCM (i.e., 0 wt %, 1 wt %, and 3 wt %) and the wall superheat (at 10 °C and 30 °C), leading to a total of six cases. Numerical simulations, based on the enthalpy-porosity method, were also performed to reveal the evolutions of temperature and convective flow fields during melting. It was first shown that the numerically predicted melting front evolutions are in good agreement with the TLC imaging results. A comparison among the six cases indicated that there is a similar melting pattern that heat conduction dominates the initial stage of melting and natural convection then takes over to play a more important role when melting proceeds. With the TLC-assisted reconstruction of the melting fronts, the instantaneous melting and heat storage rates were estimated, and melting was clearly found to slow down with increasing the loading of NePCM, as a result of the dramatically increased viscosity that deteriorates the contribution of natural convection to melting heat transfer.
A Numerical Simulation on the Effect of Vaccination and Treatments for the Fractional Hepatitis B Model
Authors: Habenom Haile , Suthar D. L. , Baleanu D. , Purohit S. D.
Published: September 2020

The aim of this paper is to develop a fractional order mathematical model for describing the spread of hepatitis B virus (HBV). We also provide a rigorous mathematical analysis of the stability of the disease-free equilibrium (DFE) and the endemic equilibrium of the system based on the basic reproduction number. Here, the infectious disease HBV model is described mathematically in a nonlinear system of differential equations in a caputo sense, and hence, Jacobi collocation method is used to reduce into a system of nonlinear equations. Finally, Newton Raphson method is used for the systems of nonlinear equations to arrive at an approximate solution and matlab 2018 has helped us to simulate the nature of each compartment and effects of the possible control strategies (i.e., vaccination and isolation).
Effects of Process Parameters on Graphene Growth Via Low-Pressure Chemical Vapor Deposition
Authors: Lee Byoungdo , Chu Weishen , Li Wei
Published: September 2020

Graphene has attracted enormous research interest due to its extraordinary material properties. Process control to achieve high-quality graphene is indispensable for graphene-based applications. This research investigates the effects of process parameters on graphene quality in a low-pressure chemical vapor deposition (LPCVD) graphene growth process. A fractional factorial design of experiment is conducted to provide understanding on not only the main effect of process parameters, but also the interaction effect among them. Graphene quality including the number of layers and grain size is analyzed. To achieve monolayer graphene with large grain size, a condition with low CH4–H2 ratio, short growth time, high growth pressure, high growth temperature, and slow cooling rate is recommended. This study considers a large set of process parameters with their interaction effects and provides guidelines to optimize graphene growth via LPCVD focusing on the number of graphene layers and the grain size.
Multifunctional Three-Dimensional Curvilinear Self-Folding of Glassy Polymers
Authors: Lee Jae Gyeong , Won Sukyoung , Park Jeong Eun , Wie Jeong Jae
Published: September 2020

The selective light absorption of prestretched thermoplastic polymeric films enables wireless photothermal shape morphing from two-dimensional Euclidean geometry of films to three-dimensional (3D) curvilinear architectures. For a facile origami-inspired programming of 3D folding, black inks are printed on glassy polymers that are used as hinges to generate light-absorption patterns. However, the deformation of unpatterned areas and/or stress convolution of patterned areas hinder the creation of accurate curvilinear structures. In addition, black inks remain in the film, prohibiting the construction of transparent 3D architectures. In this study, we demonstrate the facile preparation of transparent 3D curvilinear structures with the selection of the curvature sign and chirality via the selective light absorption of detachable tapes. The sequential removal of adhesive patterns allowed sequential folding and the control of strain responsivity in a single transparent architecture. The introduction of multiple heterogeneous nonresponsive materials increased the complexity of strain engineering and functionality. External stimuli responsive kirigami-based bridge triggered the multimaterial frame to build the Gaussian curvature. Conductive material casted on the film in a pattern retained the conductivity, despite local deformation. This type of tape patterning system, adopting various materials, can achieve multifunction including transparency and conductivity.
A physical model for intuiting linear regression
Authors: Cervantes Phillip , Purdue Patricia , Steele Jeffrey
Published: September 2020

The application of linear regression to data analysis is traditionally a tedious calculation delegated to a computer. This article presents a physical model to facilitate an intuitive way of thinking about the slope of a fit. In this simple model, data points are envisioned as beads applying torques on a massless, rigid, horizontal rod. To illustrate how this model can help colleagues directly address special questions about fits, the model is applied to two situations in which there are repeated measurements of data. This rod-and-bead model also arrives at the coefficient of determination formula in a very straightforward way and makes the recollection of the least-squared slope formula and coefficient of determination much easier.
Comment on “The equivalence principle in the Schwarzschild geometry” [Am. J. Phys. 62, 1037 (1994)]
Authors: Bernar Rafael P. , Crispino Luís C. B. , Higuchi Atsushi , Lima Junior Haroldo C. D.
Published: September 2020

In the article “The equivalence principle in the Schwarzschild geometry” [Am. J. Phys. 62, 1037–1040 (1994)], some manifestation of the equivalence principle in Schwarzschild spacetime was studied. We point out that the result for the Riemann-tensor component in this article is incorrect because only the first order terms in the metric expansion are taken into account. We show the corrected result, illustrating the importance of the second order terms in the approximate metric in computing curvature quantities.
The quantum character of buckling instabilities in thin rods
Authors: Engstrom T. A.
Published: September 2020

Here the buckling of inextensible rods due to axial body forces is mapped to 1D, nonrelativistic, time-independent quantum mechanics. Focusing on the pedagogical case of rods confined to 2D, three simple and physically realizable applications of the mapping are given in detail; the quantum counterparts of these are particle in a box, particle in a delta-function well, and particle in a triangular well. A fourth application examines the buckling counterpart of a quantum many-body problem (in the Hartree approximation). Through a fifth application, given in the form of an exercise, the reader can explore the surprising consequences of adding a second transverse dimension to the rod buckling problem and imposing periodic boundary conditions.
A perfectly inelastic collision: Bulk prey engulfment by baleen whales and dynamical implications for the world's largest cetaceans
Authors: Potvin Jean , Cade David E. , Werth Alexander J. , Shadwick Robert E. , Goldbogen Jeremy A.
Published: September 2020

The largest animals are the rorquals, a group of whales which rapidly engulf large aggregations of small-bodied animals along with the water in which they are embedded, with the latter subsequently expulsed via filtration through baleen. Represented by species like the blue, fin, and humpback whales, rorquals can exist in a wide range of body lengths (8–30 m) and masses (4000–190,000 kg). When feeding on krill, kinematic data collected by whale-borne biologging sensors suggest that they first oscillate their flukes several times to accelerate towards their prey, followed by a coasting period with mouth agape as the prey-water mixture is engulfed in a process approximating a perfectly inelastic collision. These kinematic data, used along with momentum conservation and time-averages of a whale's equation of motion, show the largest rorquals as generating significant body forces (10–40 kN) in order to set into forward motion enough engulfed water to at least double overall mass. Interestingly, a scaling analysis of these equations suggests significant reductions in the amount of body force generated per kilogram of body mass at the larger sizes. In other words, and in concert with the allometric growth of the buccal cavity, gigantism would involve smaller fractions of muscle mass to engulf greater volumes of water and prey, thereby imparting a greater efficiency to this unique feeding strategy.
Captain Einstein: A VR experience of relativity
Authors: Van Acoleyen Karel , Van Doorsselaere Jos
Published: September 2020

Captain Einstein is a virtual reality (VR) movie that takes you on a boat trip in a world with a slow speed of light. This allows for a direct experience of the theory of special relativity, much in the same spirit as in the Mr. Tompkins adventure by George Gamow (1939). In this paper, we go through the different relativistic effects (e.g., length contraction, time dilation, Doppler shift, light aberration) that show up during the boat trip, and we explain how these effects were implemented in the 360° video production process. We also provide exercise questions that can be used-in combination with the VR movie-to gain insight and sharpen the intuition on the basic concepts of special relativity.
Individualized estimation of the Speech Intelligibility Index for short sentences: Test-retest reliability
Authors: Shen Yi , Yun Donghyeon , Liu Yi
Published: September 2020

The speech intelligibility index (SII) model was modified to allow individualized parameters. These parameters included the relative weights of speech cues in five octave-frequency bands ranging from 0.25 to 4 kHz, i.e., the band importance function, and the transfer function that allows the SII to generate predictions on speech-recognition scores. A Bayesian adaptive procedure, the quick-band-importance-function (qBIF) procedure, was utilized to enable efficient estimation of the SII parameters from individual listeners. In two experiments, the SII parameters were estimated for 30 normal-hearing adults using Institute of Electrical and Electronics Engineers (IEEE) sentences at speech levels of 55, 65, and 75 dB sound pressure level (in Experiment I) and for 15 hearing-impaired (HI) adult listeners using amplified IEEE or AzBio sentences (in Experiment II). In both experiments, even without prior training, the estimated model parameters showed satisfactory reliability between two runs of the qBIF procedure at least one week apart. For the HI listeners, inter-listener variability in most estimated SII parameters was larger than intra-listener variability of the qBIF procedure.
Changes in Self-Reported Physical Fitness, Performance, and Side Effects Across the Phases of the Menstrual Cycle Among Competitive Endurance Athletes
Authors: Solli Guro S. , Sandbakk Silvana B. , Noordhof Dionne A. , Ihalainen Johanna K. , Sandbakk Øyvind
Published: September 2020

Purpose: To investigate changes in self-reported physical fitness, performance, and side effects across the menstrual cycle (MC) phases among competitive endurance athletes and to describe their knowledge and communication with coaches about the MC. Methods: The responses of 140 participants (older than 18 y) competing in biathlon or cross-country skiing at the (inter)national level were analyzed. Data were collected via an online questionnaire addressing participants’ competitive level, training volume, MC history, physical fitness, and performance during the MC, MC-related side effects, and knowledge and communication with coaches about the MC and its effects on training and performance. Results: About 50% and 71% of participants reported improved and reduced fitness, respectively, during specific MC phases, while 42% and 49% reported improved and reduced performance, respectively. Most athletes reported their worst fitness (47%) and performance (30%) and the highest number of side effects during bleeding (P < .01; compared with all other phases). The phase following bleeding was considered the best phase for perceived fitness (24%, P < .01) and performance (18%, P < .01). Only 8% of participants reported having sufficient knowledge about the MC in relation to training, and 27% of participants communicated about it with their coach. Conclusions: A high proportion of athletes perceived distinct changes in fitness, performance, and side effects across the MC phases, with their worst perceived fitness and performance during the bleeding phase. Because most athletes indicate a lack of knowledge about the MC’s effect on training and performance and few communicate with coaches on the topic, the authors recommend that more time be devoted to educating athletes and coaches.
Experiential Learning of University Students Delivering a Coaching Workshop in Belize
Authors: Jacobs Jennifer M. , Kuipers Karisa L. , Richards K. Andrew R. , Wright Paul M.
Published: September 2020

Prior research has demonstrated the importance of engaging college students in a global curriculum that prepares them for the everchanging landscape of the sports industry. International learning experiences are one way to facilitate this type of professional preparation and often include the added benefit of having a deep personal impact. The purpose of this study was to understand university students’ experiences leading sessions for Belizean coaches as part of an international teaching experience. Participants were four university students pursuing interdisciplinary sport majors. Data sources included recorded interviews and daily group debrief sessions, reflective journals, social media-based photo journals, and observational fieldnotes. Qualitative data analysis resulted in the construction of three themes that described the participants’ experiences and learning outcomes: (a) personal and professional growth, (b) developing and maintaining relationships, and (c) engaging with culture. Results suggest that an international program designed to foster experiential, global learning was enhanced by the opportunity to teach in a new context, foster relationships with local stakeholders, and participate in pre- and posttrip training.
A synthetic synaptic organizer protein restores glutamatergic neuronal circuits
Authors: Suzuki Kunimichi , Elegheert Jonathan , Song Inseon , Sasakura Hiroyuki , Senkov Oleg , Matsuda Keiko , Kakegawa Wataru , Clayton Amber J. , Chang Veronica T. , Ferrer-Ferrer Maura , Miura Eriko , Kaushik Rahul , Ikeno Masashi , Morioka Yuki , Takeuchi Yuka , Shimada Tatsuya , Otsuka Shintaro , Stoyanov Stoyan , Watanabe Masahiko , Takeuchi Kosei , Dityatev Alexander , Aricescu A. Radu , Yuzaki Michisuke
Published: September 2020

Synthetic excitatory synaptic organizer

The human brain contains trillions of synapses within a vast network of neurons. Synapse remodeling is essential to ensure the efficient reception and integration of external stimuli and to store and retrieve information. Building and remodeling of synapses occurs throughout life under the control of synaptic organizer proteins. Errors in this process can lead to neuropsychiatric or neurological disorders. Suzuki
et al.
combined structural elements of natural synaptic organizers to develop an artificial version called CPTX, which has different binding properties (see the Perspective by Salinas). CPTX could act as a molecular bridge to reconnect neurons and restore excitatory synaptic function in animal models of cerebellar ataxia, familial Alzheimer's disease, and spinal cord injury. The findings illustrate how structure-guided approaches can help to repair neuronal circuits.

Science
, this issue p.
eabb4853
; see also p.
1052
Outer Membrane
c
-Type Cytochromes OmcA and MtrC Play Distinct Roles in Enhancing the Attachment of
Shewanella oneidensis
MR-1 Cells to Goethite
Authors: Jing Xinxin , Wu Yichao , Shi Liang , Peacock Caroline L. , Ashry Noha Mohamed , Gao Chunhui , Huang Qiaoyun , Cai Peng
Published: September 2020

Shewanella
species are one group of versatile and widespread dissimilatory iron-reducing bacteria, which are capable of respiring insoluble iron minerals via six multiheme
c
-type cytochromes. Outer membrane
c
-type cytochromes (
c
-Cyts) OmcA and MtrC are the terminal reductases in this pathway and have comparable protein structures. In this study, we elucidate the different roles of OmcA and MtrC in the interaction of
S. oneidensis
MR-1 with goethite at the whole-cell level. OmcA confers enhanced affinity toward goethite and results in rapid attachment. Meanwhile, MtrC significantly increases the contact area of bacterial cells with goethite and promotes the interfacial reaction, which may explain its central role in extracellular electron transfer. This study provides novel insights into the role of bacterial surface macromolecules in the interfacial interaction of bacteria with minerals, which is critical to the development of a comprehensive understanding of cell-mineral interactions.
Comprehensive Assessment of the Antigenic Impact of Human Papillomavirus Lineage Variation on Recognition by Neutralizing Monoclonal Antibodies Raised against Lineage A Major Capsid Proteins of Vaccine-Related Genotypes
Authors: Godi Anna , Boampong Dolcibella , Elegunde Busayo , Panwar Kavita , Fleury Maxime , Li Shaowei , Zhao Qinjian , Xia Ningshao , Christensen Neil D. , Beddows Simon
Published: September 2020

Human papillomavirus (HPV) is the causative agent of cervical and some other epithelial cancers. HPV vaccines generate functional (neutralizing) antibodies that target the virus particles (or capsids) of the most common HPV cancer-causing genotypes. Each genotype comprises variant forms that have arisen over millennia and which include changes within the capsid proteins. In this study, we explored the potential for these naturally occurring variant capsids to impact recognition by neutralizing monoclonal antibodies. All genotypes included at least one variant form that exhibited reduced recognition by at least one antibody, with some genotypes affected more than others. These data highlight the impact of naturally occurring variation on the structure of the HPV capsid proteins of vaccine-relevant oncogenic HPV genotypes.
Role of the Herpes Simplex Virus CVSC Proteins at the Capsid Portal Vertex
Authors: Huet Alexis , Huffman Jamie B. , Conway James F. , Homa Fred L.
Published: September 2020

Herpes simplex virus 1 (HSV-1) is the causative agent of several pathologies ranging in severity from the common cold sore to life-threatening encephalitic infection. A critical step during productive HSV-1 infection is the cleavage and packaging of replicated, concatemeric viral DNA into preformed capsids. A key knowledge gap is how the capsid engages the replicated viral genome and the subsequent packaging of a unit-length HSV genome. Here, biochemical and structural studies focused on the unique portal vertex of wild-type HSV and packaging mutants provide insights into the mechanism of HSV genome packaging. The significance of our research is in identifying the portal proteins pUL6 and pUL17 as key viral factors for engaging the terminase complex with the capsid and the subsequent cleavage, packaging, and stable incorporation of the viral genome in the HSV-1 capsid.
White Spot Syndrome Virus Benefits from Endosomal Trafficking, Substantially Facilitated by a Valosin-Containing Protein, To Escape Autophagic Elimination and Propagate in the Crustacean Cherax quadricarinatus
Authors: Meng Chuang , Liu Ling-Ke , Li Dong-Li , Gao Rui-Lin , Fan Wei-Wei , Wang Ke-Jian , Wang Han-Ching , Liu Hai-Peng
Published: September 2020

White spot disease is currently the most devastating viral disease in farmed crustaceans, such as shrimp and crayfish, and has resulted in a severe ecological problem for both brackish water and freshwater aquaculture areas worldwide. Efficient antiviral control of WSSV disease is still lacking due to our limited knowledge of its pathogenesis. Importantly, research on the WSSV infection mechanism is also quite meaningful for the elucidation of viral pathogenesis and virus-host coevolution, as WSSV is one of the largest animal viruses, in terms of genome size, that infects only crustaceans. Here, we found that most of the endocytic WSSV virions were directed to the endosomal delivery system, strongly facilitated by
Cq
VCP, so that they avoided autophagic degradation and successfully delivered the viral genome into the Hpt cell nucleus for propagation. Our data point to a virus-sorting model that might also explain the escape of other enveloped DNA viruses.
Diversity of Sea Star-Associated Densoviruses and Transcribed Endogenous Viral Elements of Densovirus Origin
Authors: Jackson Elliot W. , Wilhelm Roland C. , Johnson Mitchell R. , Lutz Holly L. , Danforth Isabelle , Gaydos Joseph K. , Hart Michael W. , Hewson Ian
Published: September 2020

The primary interest in sea star densoviruses, specifically SSaDV, has been their association with sea star wasting syndrome (SSWS), a disease that has decimated sea star populations across the West Coast of the United States since 2013. The association of SSaDV with SSWS was originally drawn from metagenomic analysis, which was further studied through field surveys using quantitative PCR (qPCR), with the conclusion that it was the most likely viral candidate in the metagenomic data based on its representation in symptomatic sea stars compared to asymptomatic sea stars. We reexamined the original metagenomic data with additional genomic data sets and found that SSaDV was 1 of 10 densoviruses present in the original data set and was no more represented in symptomatic sea stars than in asymptomatic sea stars. Instead, SSaDV appears to be a widespread, generalist virus that exists among a large diversity of densoviruses present in sea star populations.
Supplemental Material: Focused fluid flow and methane venting along the Queen Charlotte fault, offshore Alaska (USA) and British Columbia (Canada)
Authors: Prouty N.G. , al. et
Published: September 2020

Contains additional information on neural-network chimney meta-attribute analysis, U-Th analysis as well as additional figures for water column data, multichannel seismic reflection profile, and multibeam echosounder (MBES) data.
Supplemental Material: A magnetostratigraphic age constraint for the proximal synorogenic conglomerates of the Late Cretaceous Cordilleran foreland basin, northeast Utah, USA
Authors: Haque Ziaul , al. et
Published: September 2020

Table S1: Paleomagnetic results from the samples collected at different stratigraphic levels of Echo Canyon Conglomerate and Weber Canyon Conglomerate from the Echo Canyon area of northeast Utah, USA; Table S2: Paleomagnetic results from the samples collected from the red siltstone, likely Triassic age, intraclasts (cobbles and boulders) from the Echo Canyon and Weber Canyon Conglomerates in the Echo Canyon area of northeast Utah, USA.
Relationship between high-sensitivity C reactive protein and the risk of gallstone disease: results from the Kailuan cohort study
Authors: Liu Tong , Siyin Sarah Tan , Yao Nan , Duan Ning , Xu Guoshuai , Li Wenqiang , Qu Jun , Liu Siqing
Published: September 2020

Objectives

Gallstone disease (GSD) can be caused by various health and clinical factors such as obesity, dyslipidaemia and an unhealthy diet, all of which are associated with higher high-sensitivity C reactive protein (hs-CRP) concentrations. Whether hs-CRP represents an independent risk factor for GSD is still unclear. We prospectively investigated hs-CRP in relation to the occurrence of GSD based on the Kailuan study.

Study design

Prospective cohort study.

Setting

The Kailuan cohort study was conducted in Tangshan City in northern China.

Participants

95 319 participants who were free from GSD were recruited in this study. Epidemiological data, anthropometric parameters and biochemical data of participants were collected.

Primary and secondary outcome measures

Cox proportional hazards regression models were used to evaluate the association between hs-CRP concentrations and the risk of GSD after adjustments for potential confounders.

Results

During the mean 7.58 years of follow-up among 95 319 participants, 4205 participants were identified as newly diagnosed with GSD or having undergone cholecystectomy for cholelithiasis. Compared with the hs-CRP<1 mg/L group, elevated hs-CRP concentrations were significantly associated with higher risk of GSD with the corresponding HR of 1.11 (95% CI 1.03 to 1.19), 1.12 (95% CI 1.04 to 1.22) in the 1≤hs-CRP≤3 mg/L and hs-CRP>3 mg/L group, respectively. The multivariate model which included hs-CRP not only had a better line of fitness but also had better predictive values to help identify new cases of GSD during follow-up.

Conclusion

Elevated hs-CRP concentration is an independent risk factor for new-onset GSD among the Chinese population.

Trial registration number

ChiCTR-TNC-11001489.