bluuebunny/crossref_metadata_2025 huggingface dataset:
Using ITS2 metabarcoding and microscopy to analyse shifts in pollen diets of honey bees and bumble bees along a mass‐flowering crop gradient
Authors: Bänsch Svenja , Tscharntke Teja , Wünschiers Röbbe , Netter Leonie , Brenig Bertram , Gabriel Doreen , Westphal Catrin
Published: October 2020

Worldwide pollinator declines lead to pollination deficits in crops and wild plants, and managed bees are frequently used to meet the increasing demand for pollination. However, their foraging can be affected by flower availability and colony size. We investigated how mass‐flowering oilseed rape (OSR) can influence the pollen resource use of small and large honey bee (Apis mellifera L.) and bumble bee (Bombus terrestris L.) colonies. Colonies were placed adjacent to strawberry fields along a gradient of OSR availability in the landscapes. We used ITS2 metabarcoding to identify the pollen richness based on ITS2 amplicon sequencing and microscopy for quantification of target pollen. Bumble bees collected pollen from more different plant genera than honey bees. In both species, strawberry pollen collection decreased with high OSR availability but was facilitated by increasing strawberry flower cover. Colony size had no effect. The relationship between next‐generation sequencing‐generated ITS2 amplicon reads and microscopic pollen counts was positive but pollen type‐specific. Bumble bees and, to a lesser degree, honey bees collected pollen from a wide variety of plants. Therefore, in order to support pollinators and associated pollination services, future conservation schemes should sustain and promote pollen plant richness in agricultural landscapes. Both bee species responded to the availability of flower resources in the landscape. Although honey bees collected slightly more strawberry pollen than bumble bees, both can be considered as crop pollinators. Metabarcoding could provide similar quantitative information to microscopy, taking into account the pollen types, but there remains high potential to improve the methodological weaknesses.
Threat to Asian wild apple trees posed by gene flow from domesticated apple trees and their “pestified” pathogens
Authors: Feurtey Alice , Guitton Ellen , De Gracia Coquerel Marie , Duvaux Ludovic , Shiller Jason , Bellanger Marie‐Noëlle , Expert Pascale , Sannier Mélanie , Caffier Valérie , Giraud Tatiana , Le Cam Bruno , Lemaire Christophe
Published: October 2020

Secondary contact between crops and their wild relatives poses a threat to wild species, not only through gene flow between plants, but also through the dispersal of crop pathogens and genetic exchanges involving these pathogens, particularly those that have become more virulent by indirect selection on resistant crops, a phenomenon known as “pestification.” Joint analyses of wild and domesticated hosts and their pathogens are essential to address this issue, but such analyses remain rare. We used population genetics approaches, demographic inference and pathogenicity tests on host–pathogen pairs of wild or domesticated apple trees from Central Asia and their main fungal pathogen, Venturia inaequalis, which itself has differentiated agricultural and wild‐type populations. We confirmed the occurrence of gene flow from cultivated (Malus domestica) to wild (Malus sieversii) apple trees in Asian forests, potentially threatening the persistence of Asian wild apple trees. Pathogenicity tests demonstrated the pestification of V. inaequalis, the agricultural‐type population being more virulent on both wild and domesticated trees. Single nucleotide polymorphism (SNP) markers and the demographic modelling of pathogen populations revealed hybridization following secondary contact between agricultural and wild‐type fungal populations, and dispersal of the agricultural‐type pathogen population in wild forests, increasing the threat of disease in the wild apple species. We detected an SNP potentially involved in pathogen pestification, generating an early stop codon in a gene encoding a small secreted protein in the agricultural‐type fungal population. Our findings, based on joint analyses of paired host and pathogen data sets, highlight the threat posed by cultivating a crop near its centre of origin, in terms of pestified pathogen invasions in wild plant populations and introgression in the wild‐type pathogen population.
Oral Paracoccidioidomycosis affecting women: A systematic review
Authors: Costa Matheus de Castro , de Carvalho Milena Moraes , Sperandio Felipe Fornias , Ribeiro Junior Noé Vital , Hanemann João Adolfo Costa , Pigossi Suzane Cristina , de Carli Marina Lara
Published: October 2020

Paracoccidioidomycosis (PCM) is an infection caused by fungi of the genus Paracoccidioides and is marked by a strong predilection for men; nevertheless, some women have had developed PCM and have presented oral involvement by the disease. Objectives: To review all published cases until August 2020 of oral PCM in women, with emphasis on the presence of systemic changes, deleterious habits (tobacco and alcohol) and oral manifestation features through a systematic review. Methods: Observational studies (both prospective and retrospective) and case reports indexed in the Embase, PubMed, Scopus, Web of Science and LIVIVO databases were selected by two reviewers in a two‐phase process following the pre‐established PICOS criteria. Results: Twenty‐five studies met the eligibility criteria and were selected for qualitative synthesis, of which 72 participants were enrolled. Brazilian White women between 40 and 50 years were the most affected and social history revealed them to be housewives or rural workers. Fifteen women (33.3% of the informed cases) presented any systemic change at the time of PCM diagnosis, namely pregnancy, HIV infection and/or depression. Moriform stomatitis was predominant and affected preferentially the gingivae and alveolar processes in the form of a single painful lesion. Most patients were treated with sulfamethoxazole + trimethoprim or itraconazole. Conclusions: Oral PCM in women is rare; some cases showed systemic changes at the time of PCM diagnosis, namely HIV infection, pregnancy and depression. New studies should be conducted to elucidate the influence of systemic alterations on the development of oral PCM in women.
China's Development Model: Can it be Replicated in Sub‐Saharan Africa?
Authors: Babones Salvatore
Published: October 2020

Viewed as an economic long march from poverty to middle‐income status, China's four decades of rapid economic growth can seem little short of miraculous. Unsurprisingly, such a record is bound to inspire imitators, and China's political‐economic model of authoritarian capitalism or state‐sponsored neoliberalism has attracted many admirers in Africa. But viewed as a rapid rebound after the removal of catastrophic Maoist economic mismanagement, China's growth spurt has done little more than bring China up to the level of other semiperipheral countries in Asia, the post‐Soviet space, and Latin America. China's economy rapidly grew to a level commensurate with its state capacity, and it is now leveling out at that level. The low levels of state capacity that have historically prevented most African countries from reaching middle‐income levels of GDP per capita still prevail, and until these change, African countries will not be able to follow China into middle‐income status.

Related Articles (in this Special Issue)

Davidsson, Simon. 2020. “Modeling the Impact of a Model: The (Non)Relationship between China's Economic Rise and African Democracy.” Politics & Policy 48 (5).

Hodzi, Obert. 2020. “African Political Elites and the Making(s) of the China Model in Africa.” Politics & Policy 48 (5).

Hodzi, Obert, and John H. S. Åberg. 2020. “Introduction to the Special Issue: Strategic Deployment of the China Model in Africa.” Politics & Policy 48 (5).
Differential survival of nursery‐reared Acropora cervicornis outplants along the Florida reef tract
Authors: van Woesik Robert , Banister Raymond B. , Bartels Erich , Gilliam David S. , Goergen Elizabeth A. , Lustic Caitlin , Maxwell Kerry , Moura Amelia , Muller Erinn M. , Schopmeyer Stephanie , Winters R. S. , Lirman Diego
Published: October 2020

In recent decades, the Florida reef tract has lost over 95% of its coral cover. Although isolated coral assemblages persist, coral restoration programs are attempting to recover local coral populations. Listed as threatened under the Endangered Species Act, Acropora cervicornis is the most widely targeted coral species for restoration in Florida. Yet strategies are still maturing to enhance the survival of nursery‐reared outplants of A. cervicornis colonies on natural reefs. This study examined the survival of 22,634 A. cervicornis colonies raised in nurseries along the Florida reef tract and outplanted to six reef habitats in seven geographical subregions between 2012 and 2018. A Cox proportional hazards regression was used within a Bayesian framework to examine the effects of seven variables: (1) coral‐colony size at outplanting, (2) coral‐colony attachment method, (3) genotypic diversity of outplanted A. cervicornis clusters, (4) reef habitat, (5) geographical subregion, (6) latitude, and (7) the year of monitoring. The best models included coral‐colony size at outplanting, reef habitat, geographical subregion, and the year of monitoring. Survival was highest when colonies were larger than 15 cm (total linear extension), when outplanted to back‐reef and fore‐reef habitats, and when outplanted in Biscayne Bay and Broward–Miami subregions, in the higher latitudes of the Florida reef tract. This study points to several variables that influence the survival of outplanted A. cervicornis colonies and highlights a need to refine restoration strategies to help restore their population along the Florida reef tract.
Barriers to optimal vascular access for hemodialysis
Authors: Brown Robert S.
Published: October 2020

Vascular access is the Achilles heel for hemodialysis (HD). An arteriovenous fistula (AVF), considered the optimal access for HD, rather than a graft or central venous catheter (CVC) caused the “Fistula First” initiative to dominate quality assessment. However, this initiative had the unintended consequence of increasing the proportion of less desirable catheters, leading to “Fistula First, Catheter Last”. But as the end‐stage kidney disease (ESKD) population expanded with aging, sicker patients, individual assessment of the appropriate access changed the paradigm to KDOQI’s “Patient First: ESKD Life‐Plan” to attain the “right access, in the right patient, at the right time, for the right reasons”. However, such a goal has proved elusive because the optimal vascular access does not currently exist. Thus, ESKD care providers attempting to offer the “right access” must weigh the barriers to achieving the most optimal access to suit each of their HD patients. The barriers are based on shortcomings related specifically to each of the three vascular accesses and to characteristics of each ESKD patient's demographics, physical factors, quality of life, and cost considerations. This article will describe these barriers so that clinicians caring for ESKD patients initiating or receiving HD provide the most optimal vascular access for that specific patient.
Teaching linear correlation using contour plots
Authors: Paolino Jon‐Paul
Published: October 2020

This paper presents a novel method for introductory teaching of the sample linear correlation coefficient from a bivariate dataset. Linear correlation is typically included in curriculums at the secondary and introductory tertiary levels of education. The method discussed herein can be used by educators in elementary courses at either of these levels. We explain how scatterplots with the addition of contour plots can be used to teach the strength and direction of linear relationship between two variables; and demonstrate the production of contour plots using statistical computing software. Finally, we show how this innovative method could be included in classroom activities.
The central blood volume as measured by thoracic electrical impedance and plasma proANP is not compromised by donation of 900 mL of blood in men
Authors: Gybel‐Brask Mikkel , Nordsborg Nikolai Baastrup , Goetze Jens P. , Johansson Pär I. , Secher Niels H. , Bejder Jacob
Published: October 2020

Objectives

To evaluate whether the donation of 900 mL of blood reduces the central blood volume (CBV) assessed by thoracic electrical impedance (TI) and plasma pro‐atrial natriuretic peptide (proANP).

Background

Donation of 450 mL of blood carries a 1% risk of a vasovagal reaction. Withdrawal of 900 mL of blood decreases cardiac output; however, the effect on CBV remains unknown.

Methods/Materials

A randomised, single‐blinded, placebo‐controlled, crossover design was used, where 21 healthy semi‐recumbent men donated 2 × 450 mL blood or were sham‐phlebotomised. Changes in CBV were estimated by proANP and TI at 1.5 (TI1.5) and 100 (TI100) kHz, reflecting extracellular volume and (regional) total body water, respectively, and the index value (IDX; 1/T1.5‐1/TI100) was used to estimate changes in intracellular (red cell) volume. Systolic, diastolic and mean arterial blood pressure; heart rate; stroke volume; cardiac output; and systemic vascular resistance were monitored. After completion of the study, 1000 mL of isotonic saline was infused.

Results

Changes (mean% ± SD) in TI1.5, TI100 and IDX were similar after 450 mL (−0.2 ± 1.6%, 0.0 ± 1.1%, −0.4 ± 10.1%) and 900 mL (0.1 ± 1.6%, 0.2 ± 1.5% and −2.0 ± 15.8%) of blood donation compared to after a sham donation of 450 mL (−0.9 ± 1.2%, −0.5 ± 1.5% and −0.1 ± 6.1%) and 900 mL (−1.2 ± 1.5%, −0.6 ± 1.3% and 0.5 ± 9.9%). In addition, changes in plasma proANP were similar after 450 and 900 mL of blood donation (−0.8 ± 6.7% and −7.6 ± 7.9%) as after sham donations (1.3 ± 7.3% and −4.5 ± 5.6%). Monitoring haemodynamic variables revealed that stroke volume decreased after the donation of 900 mL of blood (−12 ± 12 mL) compared to sham donations.

Conclusion

During a 900‐mL blood loss in semi‐recumbent men, CBV measured by TI and plasma proANP is not affected.
Transition from room temperature to cold‐stored platelets for the preservation of blood inventories during the COVID‐19 pandemic
Authors: Warner Matthew A. , Kurian Emil B. , Hammel Scott A. , van Buskirk Camille M. , Kor Daryl J. , Stubbs James R.
Published: October 2020

Background

The COVID‐19 pandemic has placed great strain on blood resources. In an effort to extend platelet (PLT) shelf life and minimize waste, our institution transitioned room temperature to cold‐stored PLTs for administration to bleeding patients.

Study Design and Methods

We describe the administrative and technical processes involved in transitioning room temperature PLTs to cold storage in April 2020. Additionally, we describe the clinical utilization of cold‐stored PLTs in the first month of this practice change, with a focus on changes in PLT counts after transfusion, hemostasis, and safety outcomes.

Results

A total of 61 cold‐stored PLT units were transfused to 40 bleeding patients, with a median (interquartile range [IQR]) of 1 (1‐2) units per patient. The median age was 68 (59‐73) years; 58% male. Median pretransfusion and posttransfusion PLTs counts were 88 (67‐109) and 115 (93‐145). A total of 95% of transfusions were administered in the operating room: 57% cardiac surgery, 20% vascular surgery, 8% general surgery, and 5% solid organ transplantation. Hemostasis was deemed to be adequate in all cases after transfusion. There were no transfusion reactions. One patient (3%) experienced a fever and infection within 5 days of transfusion, which was unrelated to transfusion. Median (IQR) hospital length of stay was 8.5 (6‐17) days. Two patients (5%) died in the hospital of complications not related to transfusion.

Conclusion

Cold‐stored PLT utilization was associated with adequate hemostasis and no overt signal for patient harm. Conversion from room temperature to cold‐stored PLTs may be one method of reducing waste in times of scarce blood inventories.
Aging Mechanisms and Thermal Characteristics of Commercial 18650 Lithium-Ion Battery Induced by Minor Mechanical Deformation
Authors: Li Ling , Chen Xiaoping , Hu Rufu , Wang Tao , Ji Hongbo , Yuan Quan , Ji Yingping , Jiang Zhongqing , Liu Wen , Zheng Weigong
Published: October 2020

Lithium-ion batteries (LIBs) inevitably encounter abusive mechanical loading during engineering applications and result in mechanical deformation, internal short circuit, and even thermal runaway. A 18650 LIB under minor mechanical deformation is subjected to cyclic charge/discharge experiments in this study to analyze its aging behavior. Aging mechanism of the battery with minor deformation is qualitatively investigated through the incremental capacity analysis (ICA). ICA, a commonly used method for exploring degradation mechanism of LIBs, can transform flat voltage plateaus into peaks in the capacity increase curve (IC curve). Experimental data during the battery charging/discharging cycle can be used to calculate the IC curve, which can reflect the characteristics of electrochemical changes inside the battery. Results showed that the LIB suffers from deterioration in the state of health (SOH) in the entire charge/discharge cycle upon minor mechanical deformation. Possible explanations for the slight decrease in SOH with the increasing number of cycles in the early stages and the rapid decrease in the charge/discharge capacity in the late stages were provided. However, precise mechanisms for these phenomena require further detailed research. Moreover, damaged cells demonstrate considerably higher temperature increments than original ones. This temperature difference will increase if additional charging/discharging cycles are conducted. This research infers that additional metallic lithium deposits in damaged cells compared with the original ones cause serious exothermic reactions and lead to enhanced heat accumulation.
Parametric Study on the Safety Behavior of Mechanically Induced Short Circuit for Lithium-Ion Pouch Batteries
Authors: Li Honggang , Zhou Dian , Du Chunlin , Zhang Chao
Published: October 2020

Safety issues of lithium-ion batteries under mechanical abuse have attracted worldwide attention due to its high uncertainty and high risks, following by the rapid increase of market share for lithium-ion battery-driven smart products. In this work, the safety behavior of a pouch battery under mechanical abuse conditions is numerically investigated using a simultaneously coupled mechanical–electrochemical–thermal model. The short-circuit and electrochemical–thermal responses of lithium-ion batteries under various mechanical abuse conditions are successfully predicted and compared. The main impact factors, including the state of charge (SOC), indenter shape and size, and loading displacement, are systematically studied and analyzed. The comprehensive parametric studies show that the battery is in a more dangerous state under higher SOC, identify the critical distinction of the short-circuit behavior between sharp indenter and blunt indenters for battery, and explain the discrepancies in the repeated mechanical abuse tests. These conclusions provide theoretical insights for understanding the failure mechanism of lithium-ion batteries under mechanical abuse, and technical support for the safety design of battery packs.
Effect of Ligament Properties on Nonlinear Dynamics and Wear Prediction of Knee Prostheses
Authors: Askari Ehsan , Andersen Michael S.
Published: October 2020

Although wear is known as the primary cause of long-time failure of total knee arthroplasty (TKA), it can be vital in short- and midterm TKA failure due to laxity. One of the reasons leading to joint laxity and instability is ligamentous insufficiency. This study, therefore, aims to investigate the effects of insufficient ligaments-related knee laxity on both nonlinear dynamics and wear of TKA. The study hypothesizes (a) ligamentous insufficiency can increase TKA damage; (b) stiffness reduction of each of the posterior cruciate ligament (PCL) and medial–lateral collateral ligaments (MCL-LCL) can differently contribute to TKA damage. A forward dynamics methodology is developed and the ligament behavior is simulated employing an asymmetric nonlinear elastic model. External loads and moment, due to the presence of all soft tissues, e.g., muscles and hip joint reaction forces, applied to the femoral bone are determined using a musculoskeletal approach linked to the developed model. A mesh density analysis is performed and comparing outcomes with that available in the literature allows for the assessment of our approach. From the results acquired, reduced PCL stiffness leads to an increase in linear wear rates and results in the maximum damage in TKAs. However, the maximum linear wear rates on both condyles occur once the stiffness of all ligaments is reduced. Moreover, the worn area of the tibia surface increases with the reduction in MCL-LCL stiffness on the medial condyle. The joint with insufficient PCL also shows a considerable increase in ligament forces right after toe-off.
Numerical Analysis of Gas Distribution in 1000 W-Class Solid Oxide Fuel Cell Stack With Internal and External Manifolding
Authors: Blesznowski M. , Boiski M. , Kupecki J.
Published: October 2020

Solid oxide fuel cells (SOFC) can generate electricity and heat with a minimal negative impact on the environment and with high electrical efficiency (∼60%). SOFC stacks are the key component of cogeneration units in the range from several kiloWatts up to hundreds of kiloWatts. The larger power output of a system is achieved by the multiplication of a number of separate modules, which are usually based on 1000 W class stacks. In the design of the SOFC stack, the following parts are distinguished: two terminating plates (top and bottom), interconnectors, separators, gaskets, electrical connections, fuel and oxidant delivery lines, and fuel cells. Geometric features and physical and chemical properties of the aforementioned components affect the performance and mechanical strength of the SOFC stack. Two different approaches for air supply can be used and were investigated, namely internal and external manifolding. Comprehensive analysis of the geometric features of the stack together with inserts, the supply and discharge piping of reaction gases, was performed in order to determine the optimal operating conditions on the latest third generation of the SOFC stack, which is currently under development at the Institute of Power Engineering (IEN). This study includes the results of laboratory tests and numerical studies. The results obtained indicate the set of parameters that influence the performance and lifetime of SOFCs. Among others, the most important variables are as follows: fuel type, operating conditions, homogeneity of temperature distribution, and uniformity of gas flow.
Determining Isolated Thumb Forces in Osteoarthritic and Healthy Persons
Authors: Vocelle Amber R. , Shafer Gail , Bush Tamara Reid
Published: October 2020

Carpometacarpal (CMC) osteoarthritis (OA) can dramatically impair thumb function resulting in the inability to complete basic tasks. Development of a method to detect thumb forces changes is essential to understand of the progression of carpometacarpal osteoarthritis and the effects of treatment. The goals of this study were to (1) develop a method to measure thumb forces in multiple directions, (2) perform an initial demonstration of this method on three populations, young healthy (YH), older healthy (OH), and older participants with carpometacarpal osteoarthritis, and (3) determine the effects of short-term exercises on thumb force production in these pilot groups. A multi-axis load cell with a custom-built apparatus and a hand grip dynamometer were used to measure thumb and grip forces. Forces were collected in four directions: radial abduction and adduction, and palmar abduction and adduction. All participants completed thumb and grip testing prior to (week 0), during (week 2), and following (week 6), a hand exercise regimen. Group differences and the effects of exercise on force production were determined. Hand exercises improved thumb forces in young healthy female participants during radial (p = 0.017) and palmar abduction (p = 0.031) and female participants with osteoarthritis during palmar abduction (p = 0.010). Exercise improved grip strength in young healthy males (p = 0.028), young healthy females (p = 0.041), and females with osteoarthritis (p = 0.027). This research demonstrates the successful use of a new device to determine isolated thumb forces, and its clinical utility to identify changes after a short exercise regimen.
Comparison of Poincaré Normal Forms and Floquet Theory for Analysis of Linear Time Periodic Systems
Authors: Subramanian Susheelkumar C. , Redkar Sangram
Published: October 2020

In this work, the authors draw comparisons between the Floquet theory and Normal Forms technique and apply them towards the investigation of stability bounds for linear time periodic systems. Though the Normal Forms technique has been predominantly used for the analysis of nonlinear equations, in this work, the authors utilize it to transform a linear time periodic system to a time-invariant system, similar to the Lyapunov–Floquet (L–F) transformation. The authors employ an intuitive state augmentation technique, modal transformation, and near identity transformations to facilitate the application of time-independent Normal Forms. This method provides a closed form analytical expression for the state transition matrix (STM). Additionally, stability analysis is performed on the transformed system and the comparative results of dynamical characteristics and temporal variations of a simple linear Mathieu equation are also presented in this work.
An In Situ Fabrication of CuGa2 Film on Copper Surface With Improved Tribological Properties
Authors: Li Xing , Yan Chao , Liu Qi , Dong Guangneng
Published: October 2020

Interface interaction between gallium-based liquid metal and copper-based materials results in the formation of intermetallic CuGa2 grains. In particular, CuGa2 grains are able to produce a uniform film and the newly formed CuGa2 film holds peculiar characteristics, which have not been fully explored up to now. In this study, we present an electrochemical fabrication method of an in situ CuGa2 film on copper surface. Surface morphology and chemical composition of this film are confirmed. Tribological experiments demonstrate that the CuGa2 film enables good antifriction and antiwear abilities. Furthermore, the lubrication mechanisms of the CuGa2 film are revealed.
Oblique angle initiated chemical vapor deposition for patterning film growth
Authors: Welchert Nicholas A. , Cheng Christine , Karandikar Prathamesh , Gupta Malancha
Published: October 2020

Initiated chemical vapor deposition (iCVD) can be used to deposit thin polymer films on a variety of substrates. In this work, the monomer precursor was introduced at an oblique angle to the substrate using an inlet extension, and the pattern of the resulting polymer film was studied as a function of deposition time, substrate temperature, monomer flow rate, reactor pressure, and vapor flow angle. The polymerizations of n-butyl acrylate, methacrylic acid, and 2-hydroxyethyl methacrylate were examined to determine the generality of the trends across several monomers. It was found that the monomer flow rate significantly affected the pattern of the deposited polymer by shifting the location of the thickest point in the films. Increasing the deposition time, decreasing the substrate temperature, and increasing the reactor pressure all increased the polymer deposition rate consistent with conventional iCVD; however, the pattern of the deposited polymer did not vary with these parameters. Computational analysis was used to determine how the inlet extension affects the pressure and velocity profiles within the reactor. The data demonstrate that the introduction of a monomer precursor at an oblique angle can be used to pattern polymer films during iCVD.
Asteroid (101955) Bennu’s weak boulders and thermally anomalous equator
Authors: Rozitis B. , Ryan A. J. , Emery J. P. , Christensen P. R. , Hamilton V. E. , Simon A. A. , Reuter D. C. , Al Asad M. , Ballouz R.-L. , Bandfield J. L. , Barnouin O. S. , Bennett C. A. , Bernacki M. , Burke K. N. , Cambioni S. , Clark B. E. , Daly M. G. , Delbo M. , DellaGiustina D. N. , Elder C. M. , Hanna R. D. , Haberle C. W. , Howell E. S. , Golish D. R. , Jawin E. R. , Kaplan H. H. , Lim L. F. , Molaro J. L. , Munoz D. Pino , Nolan M. C. , Rizk B. , Siegler M. A. , Susorney H. C. M. , Walsh K. J. , Lauretta D. S.
Published: October 2020

Heterogeneous thermal properties of Bennu are due primarily to spatial mixing of two boulder types with differing strengths.
Behavioral nudges reduce failure to appear for court
Authors: Fishbane Alissa , Ouss Aurelie , Shah Anuj K.
Published: October 2020

“Nudges” and criminal justice

Criminal justice policy in the United States focuses on increasing negative consequences to deter undesired behavior. However, defendants often appear relatively insensitive to these changes in the severity of consequences. Fishbane
et al.
considered a different policy lever: improving the communication of information necessary to adhere to desired behavior (see the Perspective by Kohler-Hausmann). They found that redesigning a criminal summons form to highlight critical information and providing text message reminders increased the likelihood that defendants would show up to their appointed court date, thus eliminating a substantial percentage of arrest warrants for failing to appear in court. In follow-up experiments, the authors found that laypeople, but not experts, believe that such failures to appear are relatively intentional, and this belief reduces their support for interventions aimed at increasing awareness rather than punishment. These findings have implications for policies aimed at improving criminal justice outcomes.

Science
, this issue p.
eabb6591
; see also p.
658
Widespread carbon-bearing materials on near-Earth asteroid (101955) Bennu
Authors: Simon Amy A. , Kaplan Hannah H. , Hamilton Victoria E. , Lauretta Dante S. , Campins Humberto , Emery Joshua P. , Barucci M. Antonietta , DellaGiustina Daniella N. , Reuter Dennis C. , Sandford Scott A. , Golish Dathon R. , Lim Lucy F. , Ryan Andrew , Rozitis Benjamin , Bennett Carina A.
Published: October 2020

The complex history of Bennu's surface

The near-Earth asteroid (101955) Bennu is a carbon-rich body with a rubble pile structure, formed from debris ejected by an impact on a larger parent asteroid. The Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) spacecraft is designed to collect a sample of Bennu's surface and return it to Earth. After arriving at Bennu, OSIRIS-REx performed a detailed survey of the asteroid and reconnaissance of potential sites for sample collection. Three papers present results from those mission phases. DellaGiustina
et al.
mapped the optical color and albedo of Bennu's surface and established how they relate to boulders and impact craters, finding complex evolution caused by space weathering processes. Simon
et al.
analyzed near-infrared spectra, finding evidence for organic and carbonate materials that are widely distributed across the surface but are most concentrated on individual boulders. Kaplan
et al.
examined more detailed data collected on the primary sample site, called Nightingale. They identified bright veins with a distinct infrared spectrum in some boulders, which they interpreted as being carbonates formed by aqueous alteration on the parent asteroid. Together, these results constrain Bennu's evolution and provide context for the sample collected in October 2020.

Science
, this issue p.
eabc3660
, p.
eabc3522
, p.
eabc3557
Generation of helical topological exciton-polaritons
Authors: Liu Wenjing , Ji Zhurun , Wang Yuhui , Modi Gaurav , Hwang Minsoo , Zheng Biyuan , Sorger Volker J. , Pan Anlian , Agarwal Ritesh
Published: October 2020

Polaritons with a twist

The ability to design and fabricate optical systems with tunable topological features makes them especially attractive for developing analogs of topological condensed matter systems, which by themselves tend to be fixed or limited in their tunability. Liu
et al.
now show that the combination of a two-dimensional material with a photonic crystal can be used to develop an analogous quantum spin Hall system. The strong coupling between the monolayer tungsten disulfide excitons with a nontrivial hexagonal photonic crystal gives rise to helical topological polaritons observed at up to 200 kelvin. The topological polaritons can be actively tuned by temperature and may further be manipulated with electric or magnetic fields, thereby providing a flexible platform with which to explore exotic topological phenomena and new phases of quantum matter.

Science
, this issue p.
600
Role of
metAB
in Methionine Metabolism and Optimal Chicken Colonization in Campylobacter jejuni
Authors: Ruddell Brandon , Hassall Alan , Sahin Orhan , Zhang Qijing , Plummer Paul J. , Kreuder Amanda J.
Published: October 2020

Campylobacter jejuni
is a zoonotic pathogen and is one of the leading causes of human gastroenteritis worldwide.
C. jejuni
IA3902 (representative of the sheep abortion clone) is genetically similar to
C. jejuni
W7 (representative of strain type NCTC 11168); however, there are significant differences in the ability of
luxS
mutants of these strains to colonize chickens. LuxS is essential for the activated methyl cycle and generates homocysteine for conversion to
l
-methionine.
Fifteen-minute consultation: Severe traumatic brain injury in paediatrics
Authors: Molloy Seana , Batchelor Gemma , Mallett Peter , Thompson Andrew , Bourke Thomas , Fitzsimons Andrew , Richardson Julie
Published: October 2020

Paediatric traumatic brain injury (TBI) is a non-degenerative, acquired brain insult. Following a blow or penetrating trauma to the head, normal brain function is disrupted. If it occurs during the early stages of development, deficits may not immediately become apparent but unfold and evolve over time. We address the difficulties that arise when treating a child with severe TBI.
Managing head injury risks in competitive skateboarding: what do we know?
Authors: McIntosh Andrew Stuart , Patton Declan Alexander , McIntosh Alexander GD
Published: October 2020

Objectives

The broad objective of this paper is to inform policy, practice and research regarding the management of head injury risks in competitive skateboarding. The main motivation for the current study was the question of mandating helmet use in competitive skateboarding. The specific aims are to present current knowledge on (A) head injury risks in skateboarding, (B) preliminary biomechanical data on falls and head injury risks in a selection of competitive skateboarding events similar to those planned for the Summer Olympics, (C) standards for skateboard-styled helmets and (D) impact performance of helmets commonly used in skateboarding.

Methods

A narrative review of the published literature on head injuries in skateboarding was conducted. Videos of skateboarding competitions from Vans Park Professional League, Street League Skateboarding and Dew Tour were reviewed to describe crashes and falls. Standards databases including the International Organization for Standardization (ISO), British Standards Institution (BSI), Snell, United States Consumer Product Safety Commission (CPSC) and American Society for Testing and Materials (ASTM) were searched for skateboarding-styled helmet standards. A sample of helmets considered suitable for skateboarding was tested in standard impact tests.

Results

The majority of previous literature focused on the paediatric population in a recreational setting with little data from competitive skateboarding. Head injuries comprised up to 75% of all injuries and helmet use was less than 35%. Video analysis identified high rates of falls and crashes during competitive skateboarding, but also a capacity for the athletes to control falls and limit head impacts. Less than 5% of competitive skateboarders wore helmets. In addition to dedicated national skateboard helmet standards, there are several national standards for skateboard-styled helmets. All helmets, with the exception of one uncertified helmet, had similar impact attenuation performance; that is, at 0.8 m drop height, 114–148 g; at 1.5 m, 173–220 g; and at 2.0 m, 219–259 g. Impact performance in the second impact was degraded in all helmets tested.

Conclusion

Helmets styled for skateboarding are available ‘off the shelf’ that will offer protection to the head against skull fractures and intracranial injuries in competitive skateboarding. There is an urgent need to commence a programme of research and development to understanding and control head injury risks.
Effect of exercise training for five years on all cause mortality in older adults—the Generation 100 study: randomised controlled trial
Authors: Stensvold Dorthe , Viken Hallgeir , Steinshamn Sigurd L , Dalen Håvard , Støylen Asbjørn , Loennechen Jan P , Reitlo Line S , Zisko Nina , Bækkerud Fredrik H , Tari Atefe R , Sandbakk Silvana B , Carlsen Trude , Ingebrigtsen Jan E , Lydersen Stian , Mattsson Erney , Anderssen Sigmund A , Fiatarone Singh Maria A , Coombes Jeff S , Skogvoll Eirik , Vatten Lars J , Helbostad Jorunn L , Rognmo Øivind , Wisløff Ulrik
Published: October 2020

Objective

To evaluate the effect of five years of supervised exercise training compared with recommendations for physical activity on mortality in older adults (70-77 years).

Design

Randomised controlled trial.

Setting

General population of older adults in Trondheim, Norway.

Participants

1567 of 6966 individuals born between 1936 and 1942.

Intervention

Participants were randomised to two sessions weekly of high intensity interval training at about 90% of peak heart rate (HIIT, n=400), moderate intensity continuous training at about 70% of peak heart rate (MICT, n=387), or to follow the national guidelines for physical activity (n=780; control group); all for five years.

Main outcome measure

All cause mortality. An exploratory hypothesis was that HIIT lowers mortality more than MICT.

Results

Mean age of the 1567 participants (790 women) was 72.8 (SD 2.1) years. Overall, 87.5% of participants reported to have overall good health, with 80% reporting medium or high physical activity levels at baseline. All cause mortality did not differ between the control group and combined MICT and HIIT group. When MICT and HIIT were analysed separately, with the control group as reference (observed mortality of 4.7%), an absolute risk reduction of 1.7 percentage points was observed after HIIT (hazard ratio 0.63, 95% confidence interval 0.33 to 1.20) and an absolute increased risk of 1.2 percentage points after MICT (1.24, 0.73 to 2.10). When HIIT was compared with MICT as reference group an absolute risk reduction of 2.9 percentage points was observed (0.51, 0.25 to 1.02) for all cause mortality. Control participants chose to perform more of their physical activity as HIIT than the physical activity undertaken by participants in the MICT group. This meant that the controls achieved an exercise dose at an intensity between the MICT and HIIT groups.

Conclusion

This study suggests that combined MICT and HIIT has no effect on all cause mortality compared with recommended physical activity levels. However, we observed a lower all cause mortality trend after HIIT compared with controls and MICT.

Trial registration

ClinicalTrials.govNCT01666340.
Eccentric cycling ergometer to address skeletal muscle dysfunction in hospitalised patients: ergometer design, construction and demonstration
Authors: Doyle Mathew , Brown Marc , Kemp Lucy , McLennan Peter , Peoples Gregory
Published: October 2020

Purpose

Continuous eccentric cycling has demonstrated metabolic efficiency when compared with equivalent concentric workloads. The profile of continuous eccentric cycling is well suited to hospitalised patients, however, its application has been restricted to outpatient settings as ergometers appropriate for the acute setting are currently unavailable. The aim of this study was to construct an eccentric cycle ergometer specifically for use in an acute care hospital ward and demonstrate its performance in healthy subjects.

Methods

An eccentric cycle ergometer (asynchronous 125 W motor) was constructed with strain gauge technology (SRM PowerMetre) to allow instantaneous biofeedback to the user. Ten healthy participants (20–64 years) were used to test the capacity of the ergometer to maintain consistent force production (repeated 5 min duration) with appropriate physiology responses (heart rate, minute ventilation, arterial saturation, electromyography and muscle tissue oxygen saturation) for low to moderate eccentric workloads.

Results

Eccentric power output was consistently achieved without mechanical or ergonomic issues for two workloads (31.1±5.7 W and 56.6±8.8 W, respectively). Participant heart rate (rest: 68±13 bpm) and minute ventilation (rest: 12.4±3.5 L/min) increased incrementally with workload 1 (HR: 83±16 bpm V
E
: 21.76±6.5 L.min-1, p<0.001 vs rest) and workload 2 (HR: 94±14 bpm V
E
: 26.5±8.9 L/min, p<0.001 vs rest) while local muscle oxygen saturation remained unchanged for both workloads.

Conclusion

This study describes the successful construction of an eccentric cycle ergometer and demonstrated the efficacy of the ergometer to deliver constant eccentric workloads in healthy adults. Eccentric cycling could be potentially provided to hospitalised patients using this ergometer.
Evaluating spillover of HIV knowledge from study participants to their network members in a stepped-wedge behavioural intervention in Tanzania
Authors: Rewley Jeffrey , Fawzi Mary C Smith , McAdam Keith , Kaaya Sylvia , Liu Yuanyuan , Todd Jim , Andrew Irene , Onnela Jukka Pekka
Published: October 2020

Objectives

We aim to describe the social network members of participants of a behavioural intervention, and examine how the effects of the intervention may spillover among network members.

Design

Secondary analysis of a step-wedge randomised controlled trial.

Setting

Change agents (CAs) were recruited from waiting rooms of HIV treatment facilities in Dar es Salaam, Tanzania, and their network members (NMs) were recruited directly by CAs.

Participants

We enrolled 662 CAs in an HIV behavioural intervention. They, along with 710 of their NMs, completed baseline and follow-up interviews from 2011 to 2013.

Primary and secondary outcomes

The primary outcome of this study was change in NMs’ HIV knowledge, and the secondary outcome was whether the NM was lost to follow-up.

Results

At baseline, many characteristics were different between NMs and CAs. We found a number of NM characteristics significantly associated with follow-up of NMs, particularly female gender (OR=1.64, 95% CI: 1.02 to 2.63) and HIV knowledge (OR=20.0, 95% CI: 3.70 to 125); only one CA variable was significantly associated with NM follow-up: having a private source of water (OR=2.17, 95% CI: 1.33 to 3.57). The 14.2% increase in NMs’ HIV knowledge was largely due to CAs feeling empowered to pass on prior knowledge, rather than transmitting new knowledge to their NMs.

Conclusions

Characteristics of social network members of persons living with HIV persons living with HIV may play a role in study retention. Additionally, the HIV knowledge of these NMs increased largely as a function of CA participation in the intervention, suggesting that intervening among highly-connected individuals may maximise benefits to the potential population for whom spillover can occur.

Trial registration number

Clinical Trial: NCT01693458; Post-results
Health, illness and healthcare-seeking behaviour of the street dwellers of Dhaka City, Bangladesh: qualitative exploratory study
Authors: Tune Samiun Nazrin Bente Kamal , Hoque Roksana , Naher Nahitun , Islam Nazia , Mazedul Islam Md. , Ahmed Syed Masud
Published: October 2020

Objective

This study explored the illness experiences and healthcare-seeking behaviour of a cross-section of street dwellers of Dhaka City for designing a customised intervention.

Design

A qualitative exploratory study of a sample of street dwellers of Dhaka City.

Setting

Samples were taken from three purposively selected spots of Dhaka City with a high concentration of the target population.

Participants

Fifteen in-depth interviews and six informal group discussions with 40 street dwellers (≥18 years), and key informant interviews with service providers (n=6) and policymakers (n=3) were conducted during January–June 2019 to elicit necessary data.

Primary outcome measures

Qualitative narrative of illness experiences of the sampled street dwellers, relevant healthcare-seeking behaviour and experiences of interactions with health systems.

Results

We focused on three main themes, namely, reported illnesses, relevant healthcare-seeking behaviour and health system experiences of the street dwellers. Findings reveal that most of the street dwellers suffered from fever and respiratory illnesses in the last 6 months; however, a majority did not visit formal facilities. They preferred visiting retail drug shops for advice and treatment or waited for self-recovery. Formal facilities were visited only when treatment from drug shops failed to cure them or they suffered serious illnesses or traumatic injury. The reproductive-age women did not seek pregnancy care and most deliveries took place in the street dwellings. Lack of awareness, financial constraints and fear of visiting formal facilities were some of the reasons mentioned. Those who visited formal facilities faced barriers like the cost of medicines and diagnostic tests, long waiting time and opportunity cost.

Conclusions

The street dwellers lacked access to formal health systems for needed services as the latter lags far behind to outreach this extremely vulnerable population. What they need is explicit targeting with a customised package of services based on their illness profile, at a time and place convenient to them with minimum or no cost implications.
How have changes in death by cause and age group contributed to the recent stalling of life expectancy gains in Scotland? Comparative decomposition analysis of mortality data, 2000–2002 to 2015–2017
Authors: Ramsay Julie , Minton Jon , Fischbacher Colin , Fenton Lynda , Kaye-Bardgett Maria , Wyper Grant M A , Richardson Elizabeth , McCartney Gerry
Published: October 2020

Objective

Annual gains in life expectancy in Scotland were slower in recent years than in the previous two decades. This analysis investigates how deaths in different age groups and from different causes have contributed to annual average change in life expectancy across two time periods: 2000–2002 to 2012–2014 and 2012–2014 to 2015–2017.

Setting

Scotland.

Methods

Life expectancy at birth was calculated from death and population counts, disaggregated by 5 year age group and by underlying cause of death. Arriaga’s method of life expectancy decomposition was applied to produce estimates of the contribution of different age groups and underlying causes to changes in life expectancy at birth for the two periods.

Results

Annualised gains in life expectancy between 2012–2014 and 2015–2017 were markedly smaller than in the earlier period. Almost all age groups saw worsening mortality trends, which deteriorated for most cause of death groups between 2012–2014 and 2015–2017. In particular, the previously observed substantial life expectancy gains due to reductions in mortality from circulatory causes, which most benefited those aged 55–84 years, more than halved. Mortality rates for those aged 30–54 years and 90+ years worsened, due in large part to increases in drug-related deaths, and dementia and Alzheimer’s disease, respectively.

Conclusion

Future research should seek to explain the changes in mortality trends for all age groups and causes. More investigation is required to establish to what extent shortcomings in the social security system and public services may be contributing to the adverse trends and preventing mitigation of the impact of other contributing factors, such as influenza outbreaks.