bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of Arabic gum optical properties as UV-Blue light down conversion for light emitting diode application
Authors: Salah Naeem Hayder , Ahmed Naser M. , Mohammad Sabah M. , Al Shafouri M.
Published: June 2020

LED’s as energy-efficient lighting is the best way to reduce the cost besides give good brightness. The use of Arabic gum as a remote phosphor for light down conversion. In this study, two experiments were conducted using Gum Arabic Malaysia and Gum Arabic Sudan in several annealing temperature (150°C and 200°C ) and different time 20, 40, 60, 80 and 100 minutes and using different mass, 100mg and 150mg. the gum power encapsulated in 0.7ml silicone gel and dried to do remote phosphor using for light conversion. The Gum Arabic from Sudan and Malaysia were measured using HPC-2 light source colorimeter. The measured result show that the gum Arabic has high value in rendering index, CRI (colour rendering index) if the gum annealed at longer time and at the optimal temperature. The CCT (correlated colour temperature) value that show the best result or positive values are below 2500. The gum Arabic with melting process also show improvement in result. The mass of the powder used give high concentration thus the CRI value is nearest to the 80 as references value.
Al doped LiNi0.6Co0.3-xTi0.1AlxO2 cathode material via combustion method
Authors: Wan Azizan Wan Aida Hazwani , Firdaus Kasim Muhd , Rusdi Roshidah , Elong Kelimah
Published: June 2020

Aluminium (Al) was doped into cobalt sites of LiNi0.6Co0.3Ti0.1O2 (LNCT) material, producing LiNi0.6Co0.29Ti0.1Al0.01O2, LiNi0.6Co0.27Ti0.1Al0.03O2 and LiNi0.6Co0.25Ti0.1Al0.05O2 cathode materials denoted as LCA1, LCA3 and LCA5 respectively. The synthesis of those materials were using self-propagating combustion method. The doping of Al is done to reduce the toxicity of Co element and to stabilize the cathode structure in order to increase the initial discharged capacity of the lithium-ion battery system. The characterization of the materials was done by using X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM). Based on the XRD results, all materials showed a single phase structure. Meanwhile, FESEM results revealed that all materials are polyhedral like shape but the Al doped materials have smaller crystallite size than the undoped material. The electrochemical performance of the battery system using the synthesized cathode were tested. According to the battery testing results, the initial discharged capacity of the Al doped battery were successfully increased.
Reactive Sputtering Growth of Indium Nitride Thin Films on Flexible Substrate Under Different Substrate Temperatures
Authors: Osman S. A. , Ng S. S. , Hassan Z.
Published: June 2020

Indium nitride (InN) thin films were deposited on kapton polyimide substrate by using reactive gas-timing radio frequency (RF) sputtering technique. An indium target with purity of 99.999% was used. Throughout this work, the RF power and gas ratio of argon and nitrogen were maintained at 60 W and 40:60 (Ar:N2), respectively. The substrate temperature was varied from room temperature to 300°C. The surface morphology, structural and electrical properties of the deposited thin films as a function of the substrate temperature were investigated. All the deposited InN thin films have wurtzite crystal structure with preferred orientation along the (101) direction. The InN (101) peak becomes stronger and sharper as the substrate temperature increases from 100°C to 300°C. In addition, the packing density of the grains increases as the substrate temperature increases. The deposited InN films exhibit n-type conductivity behavior and its Hall mobility increases from 720 cm2/V-s to 2670 cm2/V-s as the substrate temperature increases from room temperature to 300 °C. These results imply that nucleation and crystal growth as well as the crystalline quality were improved at higher substrate temperatures. All the results lead to conclude that the optimal substrate temperature for the deposition of InN was 300 °C.
Effects of Different Amounts of Surfactant on Characteristics of Sol-Gel Dip Coated Gallium Nitride Thin Films
Authors: Maizatul H A , Ng S S
Published: June 2020

In the present study, sol-gel dip coating method was used to synthesize GaN thin films. Gallium nitrate hydrate (Ga(NO3)3.xH2O) powder and ethanol were used to prepare the precursor solution and diethanolamine (DEA) was added as stabilizer. Different amount of DEA were added into the gallium nitride (GaN) precursor at 0 ml, 0.10 ml, 0.25 ml, 0.50 ml, 0.75 ml and 1.0 ml respectively. The effects of different amounts of DEA on GaN thin films on structural and optical properties of the GaN films were studied. The high resolution X-ray diffraction results revealed that the deposited GaN thin films have hexagonal wurtzite structure with (002) preferred orientation. The intensity of the GaN (002) diffraction peaks increases with the increase of amount of surfactant from 0 ml to 0.75 ml and degraded at 1.0 ml. The Raman signal of E2 (high) GaN peaks increases and becomes stronger at 0.75 ml. Further increase in the amount of surfactant has caused the intensity of E2 (high) GaN peak decreases. The measured results show that the amount of surfactant exerts a strong influence in improving crystallinity of GaN thin films.
Synthesis and Characterization of Silica Aerogel from Rice Husk with Ambient Pressure Drying Method
Authors: Mohamad Nor Fadilah , Abdul Rani Noor Hidayu , Jehan Elham Omar Syah , Anaziah Muhamad Siti Hajar , Muda Siti Afifah , Basear Yasmin , Mohammed Faisal Muhammad Kamarulariffin
Published: June 2020

Rice husk has become global concern due to the environmental problem since it has been dumped and open burned that contributed to the emissions of carbon dioxide to the atmosphere. Therefore, utilization of rice husk to other useable product such as silica aerogel for adsorption has been study recently due to the silica content in rice husk is about 60% and this material is sustainable and cost effective. Silica aerogel was prepared from rice husk ash and dried by using ambient pressure drying method with addition of tetraethyl orthosilicate (TEOS) due to its capability to prevent the gel from crack and increase the porosity of gel to increase the capacity of adsorption process. The silica aerogel was further characterized by using Fourier Transform Infrared spectroscopy (FTIR), Elemental Anaylzer (EA) and Scanning Electron Microscopic (SEM). The results show that the silica aerogel was successfully synthesized using rice husk ash. The FTIR studies reveal that silica aerogel produced consist of amorphous silica with Si-O-Si bonding and stretching’s. From EA analysis, the carbon in the rice husk decreasing when turn into silica aerogel due to the burning of carbon content in the preparation of silica. The SEM studies confirm that the silica aerogel has a porous structure and has ability to for the application adsorption process such as carbon dioxide adsorption, methylene blue adsorption and others application.
Tensile Properties of Hybrid Pomegranate/Moringa Peel Reinforced Polyester Composites
Authors: Bin Rashidi Ahmad Ramli , Shah Buddin Meor Muhammad Hafiz
Published: June 2020

The demand for polymers escalates as a result of its expansive applications in industries such as automotive, aerospace, electronics, packaging and medical. In a reinforced polymer, synthetic fillers have been introduced to modify its mechanical properties. As part of a sustainable development effort, organic fillers are currently used instead of the synthetic type. The current work explored the potential of incorporating pomegranate peel combined with Moringa oleifera pods as a hybrid filler in the polymer to study its effect on the properties of polyester. Samples of polyester composites at different compositions of organic fillers were prepared. The composition of pomegranate peel and Moringa oleifera pods was varied from 0 to 4 wt%. A comparison study was conducted between two hybrid compositions; 4 wt% and 8 wt%. It was observed that incorporating 4 wt% of the hybrid fillers showed better characteristics. This composition of polyester recorded 6.26 MPa, 227.80 MPa and 2.91% of tensile strength(σ), Young’s modulus (E) and elongation at break (ɛ), respectively.
Luminescence Characteristics of Hybridized Polyfluorene
Authors: Hayati Ahmad Farah , Hassan Zainuriah , Jin Quah Hock , Foong Lim Way
Published: June 2020

This study was to investigate luminescence characteristics of polyfluorene (PF) hybridized with silicone (agar sample) in term of the potential application in optoelectronic. The hybridization was accomplished by preparing silicone mixture comprising of epoxy and resin into different quantities (0.625 mg, 1.25 mg, 2.5 mg) of poly [(9, 9-dioctyl-fluorenyl-2, 7-diyl)-co-(1, 4-phenylene)] end capped with dimethylphenyl dissolved in toluene solution, followed by heating at 40℃ and stirring process for 5 min. In a proof of concept phase, luminescence properties of the hybridized samples were examined by using spectroscopic techniques UV-Visible (UV-VIS), photoluminescence (PL) and electroluminescence (EL). Changes in term of the peak intensity happened with respect to the quantities of PF being hybridized. Corresponding results have been systematically presented and discussed in this work.
UV Modified Epoxy for LED Encapsulant
Authors: Cheah Lay Boon , Heng C W , Ng S Y , Teh P L , Poopalan P
Published: June 2020

Light Emitting Diode (LED) packaging is important for the protection and enhancement of light extraction efficiency in LED. The most commonly used encapsulant is epoxy resin, which is the annealing cured. Multilayer time delayed aging of the epoxy resin causes delamination during packaging process. Ultraviolet (UV) modification is introduced in the curing process of epoxy resin to enhance the curing process of the epoxy. In this paper, the samples tested are either modified with UV or vice versa. Differential Scanning Calorimeter (DSC) is used for the analysis of the sample. Six samples are tested. Data analysis is based on the heat of reactions between the mixed materials; either the process is exothermic or endothermic when the temperature changes. The reaction between the materials determines its ability to crosslink, viscosity and temperature control for the whole reaction.
Stability of quantum linear logic circuits against perturbations
Authors: Babushkin Ihar , Morgner Uwe , Demircan Ayhan
Published: June 2020

Here we study transformation of waveshapes of photons under the action of the linear logic circuits and other related architectures involving only linear optical networks and measurements. We show that the gates are working well not only in the case when all photons are separable and located in the same mode, but in some more general cases. For instance, the photonic waveshapes are allowed to be slightly different in different channels; in this case, Zeno effect prevents the photons from decoherence after the measurement, and the gate thus remains neutral to the small waveshape perturbations.
A locally hyperbolic 3-manifold that is not homotopy equivalent to any hyperbolic 3-manifold
Authors: Cremaschi Tommaso
Published: June 2020

We construct a locally hyperbolic 3-manifold

M
M

such that

π
1

(
M
)

\pi _1(M)

has no divisible subgroups. We then show that

M
M

is not homotopy equivalent to any complete hyperbolic manifold.
On the structure of hyperfields obtained as quotients of fields
Authors: Baker Matthew , Jin Tong
Published: June 2020

We determine all isomorphism classes of hyperfields of a given finite order which can be obtained as quotients of finite fields of sufficiently large order. Using this result, we determine which hyperfields of order at most 4 are quotients of fields. The main ingredients in the proof are the Weil bounds from number theory and a result from Ramsey theory.
Solution to a problem of Nirenberg concerning expanding maps
Authors: Ives Dean , Preiss David
Published: June 2020

By constructing a map of a separable Hilbert space into itself that is continuous, expanding, nonsurjective, and equal to the identity on the unit ball we answer a problem stated by Louis Nirenberg.
Convex hulls of polynomial Julia sets
Authors: Stawiska Małgorzata
Published: June 2020

We prove P. Alexandersson’s conjecture that for every complex polynomialppof degreed≥2d \geq 2the convex hullHpH_pof the Julia setJpJ_pofppsatisfiesp−1(Hp)⊂Hpp^{-1}(H_p) \subset H_p. We further prove that the equalityp−1(Hp)=Hpp^{-1}(H_p) = H_pis achieved if and only ifppis affinely conjugated to the Chebyshev polynomialTdT_dof degreedd, to−Td-T_d, or to a monomialczdc z^dwith|c|=1|c|=1.
Rapidly dynamic host cell heterogeneity in bacterial adhesion governs susceptibility to infection by Listeria monocytogenes
Authors: Rengarajan Michelle , Theriot Julie A.
Published: June 2020

Adhesion of pathogenic Listeria monocytogenes to human endothelial cells is not a random process. Instead, individual host cells are highly variable in their susceptibility. Susceptibility of individual cells can change rapidly, over the course of about an hour.
Hydrogen peroxide induces Arl1 degradation and impairs Golgi-mediated trafficking
Authors: Ireland Stephen C. , Huang Haoran , Zhang Jianchao , Li Jie , Wang Yanzhuang
Published: June 2020

H2O2 treatment induces the degradation of Golgi structural proteins in the trans-Golgi, including Arl1, Golgin-97, and Golgin-245, and thereby impairs membrane trafficking. This study revealed the trans-Golgi and trafficking at the trans-Golgi as novel targets of ROS in cells.
Geometry of the nuclear envelope determines its flexural stiffness
Authors: Agrawal Ashutosh , Lele Tanmay P.
Published: June 2020

We performed computational analysis of the bending of the nuclear envelope under applied force using a model that accounts for envelope geometry. Our calculations show that the effective bending modulus of the nuclear envelope is an order of magnitude larger than a single membrane and approximately five times greater than the nuclear lamina.
Recent advances in user-friendly computational tools to engineer protein function
Authors: Sequeiros-Borja Carlos Eduardo , Surpeta Bartłomiej , Brezovsky Jan
Published: June 2020

Progress in technology and algorithms throughout the past decade has transformed the field of protein design and engineering. Computational approaches have become well-engrained in the processes of tailoring proteins for various biotechnological applications. Many tools and methods are developed and upgraded each year to satisfy the increasing demands and challenges of protein engineering. To help protein engineers and bioinformaticians navigate this emerging wave of dedicated software, we have critically evaluated recent additions to the toolbox regarding their application for semi-rational and rational protein engineering. These newly developed tools identify and prioritize hotspots and analyze the effects of mutations for a variety of properties, comprising ligand binding, protein–protein and protein–nucleic acid interactions, and electrostatic potential. We also discuss notable progress to target elusive protein dynamics and associated properties like ligand-transport processes and allosteric communication. Finally, we discuss several challenges these tools face and provide our perspectives on the further development of readily applicable methods to guide protein engineering efforts.
Integrated Analytical Quality by Design (AQbD) Approach for the Development and Validation of Bioanalytical Liquid Chromatography Method for Estimation of Valsartan
Authors: Bandopadhyay Shantanu , Beg Sarwar , Katare O P , Sharma Teenu , Singh Bhupinder
Published: June 2020

The present studies describe the systematic development and validation of a simple, rapid, sensitive and cost-effective reversed-phase high-performance liquid chromatographic bioanalytical method for the estimation of valsartan in rat plasma employing analytical quality by design (AQbD) principles quality risk management was applied for identifying the critical method parameters (CMPs) and subsequently method optimization was performed employing Box–Behnken design by selecting mobile phase pH, flow rate and % organic modifier as the CMPs and evaluated for critical analytical attributes (CAAs) such as peak area, retention time, peak tailing and number of theoretical plates. The developed method was then transferred to bioanalysis, where liquid–liquid extraction process was used for separating the drug from rat plasma. The optimization of extraction process was performed with the help of face-centered cubic design by selecting centrifugation speed and centrifugation time as the CMPs for maximizing % recovery, signal-to-noise ratio and purity threshold of the drug peak after extraction as the CAAs. Optimum chromatographic solution was chosen by mathematical and graphical search techniques, and design space was demarcated. Validation studies performed for the developed method indicated linearity ranging between 5 and 100 ng.mL−1, whereas accuracy and precision study showed good percent recovery (99–102%) along with % relative standard deviation within ±2%. Sensitivity evaluation revealed limit of detection and limit of quantification were found to be 0.76 ng.mL−1 and 2.29 ng.mL−1, respectively. In a nutshell, the present work demonstrates significant merits of AQbD approach for holistic process understanding and analytical method development and validation with enhanced robustness and performance.
Pregnancy Outcomes of Women Conceiving on Antiretroviral Therapy (ART) Compared to Those Commenced on ART During Pregnancy
Authors: Theron Gerhard , Brummel Sean , Fairlie Lee , Pinilla Mauricio , McCarthy Katie , Owor Maxensia , Chinula Lameck , Makanani Bonus , Violari Avy , Moodley Dhayendre , Chakhtoura Nahida , Browning Renee , Hoffman Risa , Fowler Mary Glenn
Published: June 2020

Background

Globally, the number of infected women of childbearing age living with human immunodeficiency virus (HIV) and conceiving on antiretroviral therapy (ART) is increasing. Evidence of ART safety at conception and during pregnancy and adverse pregnancy outcomes remains conflicting. The Promoting Maternal and Infant Survival Everywhere (PROMISE) 1077 breastfeeding (BF) and formula feeding (FF) international multisite trials provide an opportunity to examine the impact of ART at conception on pregnancy outcomes with subsequent pregnancies.

Methods

The PROMISE 1077BF/1077FF trials were designed to address key questions in the management of HIV-infected women who did not meet clinical guidelines for ART treatment during the time of the trials. After the period of risk of mother-to-child transmission was over, women were randomized to either continue or discontinue ART. We compared subsequent pregnancy outcomes of nonbreastfeeding women randomized to continue ART following delivery, or breastfeeding women randomized to continue ART following breastfeeding cessation who conceived while on ART to women randomized to discontinue ART, who restarted ART after pregnancy was diagnosed.

Results

Pregnancy outcomes of 939 subsequent pregnancies of 826 mothers were recorded. The intention-to-treat analyses showed increased incidence of low birth weight (<2500 g) for women who conceived while on ART (relative risk, 2.65 [95% confidence interval {CI}, 1.20–5.81]), and also a higher risk of spontaneous abortion, stillbirth, or neonatal death (hazard ratio, 1.40 [95% CI, .99–1.98]) compared to women who restarted ART after they were found to be pregnant during trial follow-up.

Conclusions

We found an increased risk for adverse pregnancy outcomes in women conceiving on ART, emphasizing the need for improved obstetric and neonatal care for this group.

Clinical Trials Registration

NCT01061151.
Tree Swallow selection for wetlands in agricultural landscapes predicted by central-place foraging theory
Authors: Elgin Andrew S , Clark Robert G , Morrissey Christy A
Published: June 2020

Millions of wetland basins, embedded in croplands and grasslands, are biodiversity hotspots in North America’s Prairie Pothole Region, but prairie wetlands continue to be degraded and drained, primarily for agricultural activities. Aerial insectivorous swallows are known to forage over water, but it is unclear whether swallows exhibit greater selection for wetlands relative to other habitats in croplands and grasslands. Central-place foraging theory suggests that habitat selectivity should increase with traveling distance from a central place, such that foragers compensate for traveling costs by selecting more profitable foraging habitat. Using global positioning system (GPS) tags, we evaluated habitat selection by female Tree Swallows (Tachycineta bicolor) at 4 sites containing wetlands and where terrestrial land cover was dominated by grasslands (grass, herbaceous cover) and/or cultivated cropland. We also used sweep-net transects to assess the abundance and biomass of flying insects in different habitats available to swallows (wetland pond margins, grassy field margins, and representative uplands). As expected for a central-place forager, GPS-tagged swallows selected more for wetland ponds (disproportionate to availability), and appeared to increasingly select for wetlands with increasing distance from their nests. On cropland-dominated sites, insect abundance and biomass tended to be higher in pond margins or grassy field margins compared to cropped uplands, while abundance and biomass were more uniform among sampled habitats at sites dominated by grass and herbaceous cover. Swallow habitat selection was not clearly explained by the distribution of sampled insects among habitats; however, traditional terrestrial sampling methods may not adequately reflect prey distribution and availability to aerially foraging swallows. Overall, our results underscore the importance of protecting and enhancing prairie wetlands and other non-crop habitats in agricultural landscapes, given their disproportionate use and capacity to support breeding swallow and insect populations.
Patient loneliness in an urban, underserved family medicine residency clinic: prevalence and relationship to health care utilization
Authors: Hooker Stephanie A , Stadem Paul , Sherman Michelle D , Ricco Jason
Published: June 2020

Background

Mounting evidence suggests that loneliness increases the risk of poor health outcomes, including cardiovascular disease and premature mortality.Objective: This study examined the prevalence of loneliness in an urban, underserved family medicine residency clinic and the association of loneliness with health care utilization.

Methods

Adult patients (N = 330; M age = 42.1 years, SD = 14.9; 63% female; 58% African American) completed the 3-item UCLA Loneliness screener at their primary care visits between November 2018 and January 2019. A retrospective case–control study design was used to compare health care utilization [hospitalizations, emergency department (ED) visits, primary care visits, no-shows and referrals] in the prior 2 years between patients who identified as lonely versus those who did not. Covariates included demographics and clinical characteristics.

Results

Nearly half (44%) of patients exceeded the cut-off for loneliness. Patients who were lonely were more likely to identify as African American, have depression and have a substance use disorder. Patients in the lonely group had significantly longer hospital stays and more primary care visits, no-shows and referrals than patients in the non-lonely group; there were no differences in number of hospitalizations or ED visits.

Conclusions

The prevalence of loneliness in an urban, underserved primary care clinic was much higher than prior prevalence estimates in primary care. Patients who are lonely may use more health care resources than patients who are not lonely. Primary care may be an ideal setting in which to identify patients who are lonely to further understand the impact of loneliness on health care outcomes.
Cascading effects in freshwater microbial food webs by predatory Cercozoa, Katablepharidacea and ciliates feeding on aplastidic bacterivorous cryptophytes
Authors: Šimek Karel , Grujčić Vesna , Mukherjee Indranil , Kasalický Vojtěch , Nedoma Jiří , Posch Thomas , Mehrshad Maliheh , Salcher Michaela M
Published: June 2020

Heterotrophic nanoflagellates (HNF) are considered as major planktonic bacterivores, however, larger HNF taxa can also be important predators of eukaryotes. To examine this trophic cascading, natural protistan communities from a freshwater reservoir were released from grazing pressure by zooplankton via filtration through 10- and 5-µm filters, yielding microbial food webs of different complexity. Protistan growth was stimulated by amendments of five Limnohabitans strains, thus yielding five prey-specific treatments distinctly modulating protistan communities in 10- versus 5-µm fractions. HNF dynamics was tracked by applying five eukaryotic fluorescence in situ hybridization probes covering 55–90% of total flagellates. During the first experimental part, mainly small bacterivorous Cryptophyceae prevailed, with significantly higher abundances in 5-µm treatments. Larger predatory flagellates affiliating with Katablepharidacea and one Cercozoan lineage (increasing to up to 28% of total HNF) proliferated towards the experimental endpoint, having obviously small phagocytized HNF in their food vacuoles. These predatory flagellates reached higher abundances in 10-µm treatments, where small ciliate predators and flagellate hunters also (Urotricha spp., Balanion planctonicum) dominated the ciliate assemblage. Overall, our study reports pronounced cascading effects from bacteria to bacterivorous HNF, predatory HNF and ciliates in highly treatment-specific fashions, defined by both prey-food characteristics and feeding modes of predominating protists.
Profiling of Human Circulating Dendritic Cells and Monocyte Subsets Discriminates Between Type and Mucosal Status in Patients With Inflammatory Bowel Disease
Authors: Ortega Moreno Lorena , Fernández-Tomé Samuel , Chaparro María , Marin Alicia C , Mora-Gutiérrez Irene , Santander Cecilio , Baldan-Martin Montserrat , Gisbert Javier P , Bernardo David
Published: June 2020

Background

Intestinal dendritic cells (DC) and macrophages drive disease progression in patients with inflammatory bowel disease (IBD). We aimed to characterize the activation and homing profile of human circulating DC and monocyte subsets in healthy control patients (CP) and IBD patients.

Methods

Eighteen CP and 64 patients with IBD were categorized by diagnoses of Crohn disease (CD) and ulcerative colitis (UC), either endoscopically active (inflamed) or quiescent. Circulating type 1 conventional DC, type 2 conventional DC, plasmacytoid DC, classical monocytes, nonclassical monocytes, and intermediate monocytes were identified by flow cytometry in each individual and characterized for the expression of 18 markers. Association between DC/monocytes and IBD risk was tested by logistic regression. Discriminant canonical analyses were performed to classify the patients in their own endoscopy category considering all markers on each subset.

Results

CCRL1, CCR3, and CCR5 expression on circulating type 1 DC; CCRL1 expression on nonclassical monocytes; and CCR9 and β7 expression on classical monocytes allowed us to discriminate among the different study groups. Indeed, the same markers (excluding β7) were also associated with IBD when all DC and monocyte subsets were considered at the same time.

Conclusions

Monitoring the phenotype of human circulating DC and monocyte subsets may provide novel tools as biomarkers for disease diagnosis (CD/UC) or mucosal status (inflamed/noninflamed) in the absence of an invasive colonoscopy.
Convergent Evolution of Cichlid Fish Pharyngeal Jaw Dentitions in Mollusk-Crushing Predators: Comparative X-Ray Computed Tomography of Tooth Sizes, Numbers, and Replacement
Authors: Hulsey C Darrin , Meyer Axel , Streelman J Todd
Published: June 2020

Dental convergence is a hallmark of cichlid fish adaptive radiations. This type of repeated evolution characterizes both the oral jaws of these fishes as well as their pharyngeal jaws that are modified gill arches used to functionally process prey like hard-shelled mollusks. To test several hypotheses regarding the evolution of cichlid crushing pharyngeal dentitions, we used X-ray computed tomography scans to comparatively examine dental evolution in the pharyngeal jaw of a diversity of New World Heroine cichlid lineages. The substantial variation in erupted tooth sizes and numbers as well as replacement teeth found in these fishes showed several general patterns. Larger toothed species tended to have fewer teeth suggesting a potential role of spatial constraints in cichlid dental divergence. Species with larger numbers of erupted pharyngeal teeth also had larger numbers of replacement teeth. Replacement tooth size is almost exactly predicted (r = 0.99) from the size of erupted teeth across all of the species. Mollusk crushing was, therefore, highly associated with not only larger pharyngeal teeth, but also larger replacement teeth. Whether dental divergence arises as a result of environmental induced plasticity or originates via trophic polymorphism as found in the species Herichthys minckleyi, there appear to be general rules that structure interspecific divergence in cichlid pharyngeal erupted and replacement dentitions.
The Radiologist’s Role in a Breast Multidisciplinary Tumor Board
Authors: Rockoff Steven J , Flanagan Meghan R , Kim Janice N , Banda Kalyan , Calhoun Kristine E , Lam Diana L
Published: June 2020

Breast multidisciplinary tumor boards (MTBs) play an important role in determining treatment. This article serves as a guide for the radiologist participating in a breast MTB, as the information presented at MTB can significantly influence treatment plans and dictate future steps for further patient work-up. Multidisciplinary tumor board preparation involves a careful review of the patient’s history while gathering all relevant imaging studies, and reinterpreting them when appropriate. Presented images should be carefully selected, annotated, and displayed clearly before providing final recommendations for localization and incompletely assessed findings. Anatomic staging factors from the AJCC Breast Cancer Staging System, such as tumor size and degree of suspected skin involvement, should be described. In addition, there are many other types of information that the treatment specialists want to know. The surgeon is interested in anatomic information that will help them decide whether breast conservation therapy is feasible or if local structures, such as the nipple, can be spared. The radiation oncologist may need to know whether accelerated partial breast irradiation is feasible or if postmastectomy radiation therapy is indicated. The medical oncologist is looking for factors that may provide an indication for neoadjuvant therapy and ensuring there is a reliable follow-up method for evaluating the response to treatment, such as comparative MRI. Additionally, all specialists need to know the extent of suspected nodal involvement. By clearly and comprehensively presenting this information to the rest of the MTB team, the radiologist provides a vital contribution that guides treatment and ensures adherence to clinical guidelines.
Molecular Response of the Mediterranean Fruit Fly (Diptera: Tephritidae) to Heat
Authors: Anantanawat Kay , Papanicolaou Alexie , Hill Kelly , Xu Wei
Published: June 2020

Tephritid fruit flies are highly successful invaders and some—such as the Mediterranean fruit fly, Ceratitis capitata (Wiedemann)—are able to adapt to a large range of crops. Biosecurity controls require that shipments of produce are ensured to be pest-free, which is increasingly difficult due to the ban of key pesticides. Instead, stress-based strategies including controlled atmosphere, temperature, and irradiation can be used to eradicate flies inside products. However, unlike pesticide science, we do not yet have a robust scientific approach to measure cost-effectively whether a sufficiently lethal stress has been delivered and understand what this stress does to the biology of the pest. The latter is crucial as it would enable a combination of stresses targeting multiple molecular pathways and thus allow for lower doses of each to achieve higher lethality and reduce the development of resistance. Using heat as an example, this is the first study investigating the molecular stress response to heat in Tephritidae. Using a novel setup delivering measured doses of heat on C. capitata larvae and a high-density 11 timepoint gene expression experiment, we identified key components of lethal heat-stress response. While unraveling the complete molecular mechanism of fruit fly response to lethal stress would be a long-term project, this work curates and develops 31 potential biomarkers to assess whether sufficient lethal stress has been delivered. Further, as these protocols are straightforward and less expensive than other—omic approaches, our studies and approach will assist other researchers working on stress response.
Unveiling the Feeding Behavior of Tibraca limbativentris (Hemiptera: Pentatomidae) on Rice Using an Electropenetrography Waveform Library
Authors: Almeida André Cirilo de S , de Jesus Flávio Gonçalves , Barrigossi José Alexandre F
Published: June 2020

The rice stalk stink bug, Tibraca limbativentris Stål, damages plant stalks while feeding, making it one of the most important rice pests in South America. Because the feeding behavior of T. limbativentris has not yet been studied in rice, we investigated T. limbativentris stylet penetration (probing) in rice stalks. A waveform library was created using the new AC-DC EPG monitor with different levels of input resistance (Ri). Six different waveforms were recorded and correlated via histological studies and grouped into three phases: non-probing waveforms (Z and Np), pathway waveforms (Tl1), and ingestion waveforms (Tl2 and Tl3). The Z waveform was observed when the stink bug was standing still on the plant surface, Np when the stink bug was walking on plant surface, Tl1 was associated with stylet insertion and deep penetration into the plant tissue, and Tl2 when the stink bug was feeding on xylem vessels. The Tl3 waveform was associated with the rupture of stalk cells and was divided into two subtypes (Tl3a and Tl3b). The Tl3a waveform probably represents cell laceration with combined enzymatic maceration of stalk tissues, while Tl3b represents a short ingestion period of macerated tissues. Tibraca limbativentris uses two strategies to feed on rice stalks: a salivary sheath for feeding on xylem vessels and cell rupture (laceration and maceration) for feeding on parenchyma cells. Our study provides crucial benchmark definitions of waveforms. Future studies can now compare effects of treatments on stink bug feeding, to ultimately improve management of this pest in rice.
Multiple Primary Melanoma Incidence Trends Over Five Decades: A Nationwide Population-Based Study
Authors: Helgadottir Hildur , Isaksson Karolin , Fritz Ildiko , Ingvar Christian , Lapins Jan , Höiom Veronica , Newton-Bishop Julia , Olsson Håkan
Published: June 2020

Background

Over the past decades, many regions have experienced a steady increase in the incidence of cutaneous melanoma. Here, we report on incidence trends for subsequent primary melanoma.

Methods

In this nationwide population-based study, patients diagnosed with a first primary cutaneous melanoma reported to the Swedish Cancer Registry were followed for up to 10 years for a diagnosis of subsequent primary melanoma. Patients were grouped with patients diagnosed with first melanoma in the same decade (1960s, 1970s, 1980s, 1990s, and 2000s, respectively). Frequencies, incidence rates (IRs), standardized incidence ratios (SIRs), and 95% confidence intervals (CIs) for second melanomas were calculated. All tests of statistical significance were 2-sided.

Results

Of patients with melanoma, 54 884 were included and 2469 were diagnosed, within 10 years, with subsequent melanomas. Over the 5 decades, there was a statistically significant steady increase in the frequency, IR, and SIR for second primary melanoma. For example, in the 1960s cohort, less than 1% (IR = 1.0, 95% CI = 0.5 to 1.7, and IR = 1.1, 95% CI = 0.5 to 1.9 per 1000 person-years in women and men, respectively) had second primary melanoma, and this rose to 6.4% (IR = 7.5, 95% CI = 6.8 to 8.3, per 1000 person-years) in the women and 7.9% (IR = 10.3, 95% CI = 9.3 to 11.2, per 1000 person-years) in the men in the 2000s cohort. This rise was seen independent of age, sex, invasiveness, or site of the melanoma. Further, in patients diagnosed with a second melanoma, the frequency of those having more than 2 melanomas increased statistically significantly and was 0.0% in the 1960s and rose to 18.0% in the 2000s (P < .001).

Conclusions

This is the first study to evaluate and report on a rising trend for subsequent primary melanoma. Additional primary melanomas worsen the patients’ survival, and precautions are needed to turn this steep upgoing trend.
Measuring the matter density of the Galactic disc using stellar streams
Authors: Widmark Axel , Malhan Khyati , de Salas Pablo F , Sivertsson Sofia
Published: June 2020

We present a novel method for determining the total matter surface density of the Galactic disc by analysing the kinematics of a dynamically cold stellar stream that passes through or close to the Galactic plane. The method relies on the fact that the vertical component of energy for such stream stars is approximately constant, such that their vertical positions and vertical velocities are interrelated via the matter density of the Galactic disc. By testing our method on mock data stellar streams, with realistic phase-space dispersions and Gaia uncertainties, we demonstrate that it is applicable to small streams out to a distance of a few kilo-parsec, and that the surface density of the disc can be determined to a precision of $6{{\ \rm per\ cent}}$. This method is complementary to other mass measurements. In particular, it does not rely on any equilibrium assumption for stars in the Galactic disc, and also makes it possible to measure the surface density to good precision at large distances from the Sun. Such measurements would inform us of the matter composition of the Galactic disc and its spatial variation, place stronger constraints on dark disc substructure, and even diagnose possible non-equilibrium effects that bias other types of dynamical mass measurements.
On the divergence of first-order resonance widths at low eccentricities
Authors: Malhotra Renu , Zhang Nan
Published: June 2020

Orbital resonances play an important role in the dynamics of planetary systems. Classical theoretical analyses found in textbooks report that libration widths of first-order mean motion resonances diverge for nearly circular orbits. Here, we examine the nature of this divergence with a non-perturbative analysis of a few first-order resonances interior to a Jupiter-mass planet. We show that a first-order resonance has two branches, the pericentric and the apocentric resonance zone. As the eccentricity approaches zero, the centres of these zones diverge away from the nominal resonance location but their widths shrink. We also report a novel finding of ‘bridges’ between adjacent first-order resonances: at low eccentricities, the apocentric libration zone of a first-order resonance smoothly connects with the pericentric libration zone of the neighbouring first-order resonance. These bridges may facilitate resonant migration across large radial distances in planetary systems, entirely in the low-eccentricity regime.
Revisiting sticking property of submillimetre-sized aggregates
Authors: Arakawa Sota
Published: June 2020

Understanding the physical properties of dust aggregates is of great importance in planetary science. In this study, we revisited the sticking property of submillimetre-sized aggregates. We revealed that the ‘effective surface energy’ model used in previous studies underestimates the critical pulling force needed to separate two sticking aggregates. We also derived a new and simple model of the critical pulling force based on the canonical theory of two contacting spheres. Our findings indicate that we do not need to consider the ‘effective surface energy’ of dust aggregates when discussing the physical properties of loose agglomerates of submillimetre-sized aggregates.
The first simultaneous measurement of Hubble constant and post-Newtonian parameter from time-delay strong lensing
Authors: Yang Tao , Birrer Simon , Hu Bin
Published: June 2020

Strong gravitational lensing has been a powerful probe of cosmological models and gravity. To date, constraints in either domain have been obtained separately. We propose a new methodology through which the cosmological model, specifically the Hubble constant, and post-Newtonian parameter can be simultaneously constrained. Using the time-delay cosmography from strong lensing combined with the stellar kinematics of the deflector lens, we demonstrate that the Hubble constant and post-Newtonian parameter are incorporated in two distance ratios that reflect the lensing mass and dynamical mass, respectively. Through the re-analysis of the four publicly released lenses distance posteriors from the H0LiCOW (H0 Lenses in COSMOGRAIL’s Wellspring) collaboration, the simultaneous constraints of Hubble constant and post-Newtonian parameter are obtained. Our results suggest no deviation from the general relativity; $\gamma _{\tt {PPN}}=0.87^{+0.19}_{-0.17}$ with a Hubble constant that favours the local Universe value, $H_0=73.65^{+1.95}_{-2.26}$ km s−1 Mpc−1. Finally, we forecast the robustness of gravity tests by using the time-delay strong lensing for constraints we expect in the next few years. We find that the joint constraint from 40 lenses is able to reach the order of $7.7{{\ \rm per\ cent}}$ for the post-Newtonian parameter and $1.4{{\ \rm per\ cent}}$ for the Hubble constant.
Integrating Alternative and Augmentative Communication into Music Therapy Clinical Practice: A Clinician’s Perspective
Authors: Devlin Kerry , Meadows Anthony
Published: June 2020

This article provides an overview of Alternative and Augmentative Communication (AAC) and discusses ways in which AAC may be integrated into music therapy clinical practice with neurodivergent children and young adults. The article begins with an overview of commonly used AAC modalities and subsequently explores their use in clinical practice through a series of vignettes. This article may be of value to students who wish to understand the myriad ways in which AAC may be integrated into their clinical work and to clinicians interested in developing their clinical practice knowledge in this area.
scIGANs: single-cell RNA-seq imputation using generative adversarial networks
Authors: Xu Yungang , Zhang Zhigang , You Lei , Liu Jiajia , Fan Zhiwei , Zhou Xiaobo
Published: June 2020

Single-cell RNA-sequencing (scRNA-seq) enables the characterization of transcriptomic profiles at the single-cell resolution with increasingly high throughput. However, it suffers from many sources of technical noises, including insufficient mRNA molecules that lead to excess false zero values, termed dropouts. Computational approaches have been proposed to recover the biologically meaningful expression by borrowing information from similar cells in the observed dataset. However, these methods suffer from oversmoothing and removal of natural cell-to-cell stochasticity in gene expression. Here, we propose the generative adversarial networks (GANs) for scRNA-seq imputation (scIGANs), which uses generated cells rather than observed cells to avoid these limitations and balances the performance between major and rare cell populations. Evaluations based on a variety of simulated and real scRNA-seq datasets show that scIGANs is effective for dropout imputation and enhances various downstream analysis. ScIGANs is robust to small datasets that have very few genes with low expression and/or cell-to-cell variance. ScIGANs works equally well on datasets from different scRNA-seq protocols and is scalable to datasets with over 100 000 cells. We demonstrated in many ways with compelling evidence that scIGANs is not only an application of GANs in omics data but also represents a competing imputation method for the scRNA-seq data.
The methyltransferase TrmA facilitates tRNA folding through interaction with its RNA-binding domain
Authors: Keffer-Wilkes Laura Carole , Soon Emily F , Kothe Ute
Published: June 2020

tRNAs are the most highly modified RNAs in all cells, and formation of 5-methyluridine (m5U) at position 54 in the T arm is a common RNA modification found in all tRNAs. The m5U modification is generated by the methyltransferase TrmA. Here, we test and prove the hypothesis that Escherichia coli TrmA has dual functions, acting both as a methyltransferase and as a tRNA chaperone. We identify two conserved residues, F106 and H125, in the RNA-binding domain of TrmA, which interact with the tRNA elbow and are critical for tRNA binding. Co-culture competition assays reveal that the catalytic activity of TrmA is important for cellular fitness, and that substitutions of F106 or H125 impair cellular fitness. We directly show that TrmA enhances tRNA folding in vitro independent of its catalytic activity. In conclusion, our study suggests that F106 and H125 in the RNA-binding domain of TrmA act as a wedge disrupting tertiary interactions between tRNA’s D arm and T arm; this tRNA unfolding is the mechanistic basis for TrmA’s tRNA chaperone activity. TrmA is the second tRNA modifying enzyme next to the pseudouridine synthase TruB shown to act as a tRNA chaperone supporting a functional link between RNA modification and folding.
Mechanism of translation inhibition by type II GNAT toxin AtaT2
Authors: Ovchinnikov Stepan V , Bikmetov Dmitry , Livenskyi Alexei , Serebryakova Marina , Wilcox Brendan , Mangano Kyle , Shiriaev Dmitrii I , Osterman Ilya A , Sergiev Petr V , Borukhov Sergei , Vazquez-Laslop Nora , Mankin Alexander S , Severinov Konstantin , Dubiley Svetlana
Published: June 2020

Type II toxin–antitoxins systems are widespread in prokaryotic genomes. Typically, they comprise two proteins, a toxin, and an antitoxin, encoded by adjacent genes and forming a complex in which the enzymatic activity of the toxin is inhibited. Under stress conditions, the antitoxin is degraded liberating the active toxin. Though thousands of various toxin–antitoxins pairs have been predicted bioinformatically, only a handful has been thoroughly characterized. Here, we describe the AtaT2 toxin from a toxin–antitoxin system from Escherichia coli O157:H7. We show that AtaT2 is the first GNAT (Gcn5-related N-acetyltransferase) toxin that specifically targets charged glycyl tRNA. In vivo, the AtaT2 activity induces ribosome stalling at all four glycyl codons but does not evoke a stringent response. In vitro, AtaT2 acetylates the aminoacyl moiety of isoaccepting glycyl tRNAs, thus precluding their participation in translation. Our study broadens the known target specificity of GNAT toxins beyond the earlier described isoleucine and formyl methionine tRNAs, and suggest that various GNAT toxins may have evolved to specificaly target other if not all individual aminoacyl tRNAs.