bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Sodium Bicarbonate Additions on the Physical, Mechanical and Bioactive Property of Sol-Gel Bioglass
Authors: Fadzli SyedAdam Syed Nuzul , Irni Alias Suffi , Firuz Zainuddin
Published: November 2020

Porous bioceramics are the materials of choice for non-load bearing bone implants. Calcium phosphates and bioglass are widely used due to excellent biocompability. The primary function of porous bioceramics are as filler material for bone defects. In this research, 10% amount of sodium bicarbonates (Na2HCO3) were mixed with sol-gel derived glass powder (SiO2-CaO-P2O5) and sintered at 700 °C for 3 hours. It was found that, additions of sodium bicarbonate induced a foaming effect during sintering of bioglass thus increased the porosity content of the glass-ceramics obtained. However, the increased in porosity significantly reduced the compressive strength of the crystallized glass. The increased in porosity content and formation of sodium related phases within the crystallized glass matrix after sintering resulted in enhancement of its in vitro bioactivity property when tested in SBF solution.
A short review on polyaniline (PANI) based nanocomposites for various applications: enhancing the electrical conductivity
Authors: Khalid NorAisah , Razak Jeefferie Abd , Hasib Hazman , Ismail MohdMuzafar , Mohamad Noraiham , Junid Ramli , Puspitasari Poppy
Published: November 2020

This short review has summarized the significance of polyaniline (PANI) advanced polymer that focusing into their modification strategy, electrical conductivity and various potential applications. PANI is one type of conductive polymer that was synthesized by oxidative aniline polymerization with varied concentration of acid dopant. In recent year, many researches has been conducted specifically to enhance the electrical conductivity of PANI. There have been numbers of studies involving PANI that specially reported the electrical conductivity could be improved through proper dopant (acid) selection and robust composite strategy. The PANI based nanocomposite shows higher electrical conductivity by integrating it with nanofiller due to the filler-matrix interface contact. Therefore, by modifying the PANI properties, it could be benefited for various potential application in the future.
A short review on polyurethane-based nanocomposites for various applications
Authors: Mohamad Marina , Razak Jeefferie Abd , Mohamad Noraiham , Ahmad Sahrim Haji , Junid Ramli , Puspitasari Poppy
Published: November 2020

In recent years, polyurethane (PU) has attracted researchers’ attention due to their easily tailored properties to meet specific application requirements. PU and PU-based composites are being developed to be applied in various demanding fields such as aerospace, automotive, and electronics. This is because PU-based nanocomposites have numerous types of functional nanofiller integration. This has led to the advancement of polymer nanocomposite of PU with the inclusion of nanosised fillers for various specific purposes. In this short review article, the authors haves reviewed the fundamental or basic understanding of PU and several types of nanofillers used such as clay, carbon nanotubes, and graphene for PU-based nanocomposites development, as well as its potential applications.
Preparation of Bimetallic Catalyst: Gold-Copper (Au-Cu) Nanoparticles for Catalytic Reduction of p-Nitrophenol
Authors: Nordin Norizwan , Noor NurulAdilah Md , Wahab Najwa Afifi Abdul , Yazid Hanani , Jani AbdulMutalib Md
Published: November 2020

The combination of gold (Au) and copper (Cu) nanoparticles can enhance their chemical and physical characteristics for the application in catalysis. This combination of Au and Cu reduce the cost of Au and improve the stability of Cu towards oxidation. This study involves the preparation of Au-Cu NPs for the application in the reduction of p-nitrophenol (p-NP). The Au-Cu NPs catalyst was synthesized with different Au: Cu ratio and addition hexadecylamine (HDA). The highest rate constant (k) of 8.2 × 10−3 s−1 was obtained over 1.5 Au-Cu HDA2 catalyst. UV-Vis spectrophotometer and Transmission Electron Microscope were used to characterize the prepared sample.
Effect of glutaraldehyde as crosslinker on the properties of cellulose nanocrystal/chitosan films
Authors: Gan Pei Gie , Sam Sung Ting , Omar MohdFirdaus , Abdullah Mohammad Faiq
Published: November 2020

Cellulose nanocrystals (CNC) were isolated from the empty fruit bunch as the reinforcing filler to enhance the tensile and thermal properties of chitosan films. The addition of CNC has greatly increased the tensile strength of the chitosan films from 32.9 MPa for neat chitosan film to 50.9 MPa for 5 wt% CNC/chitosan films. The addition of glutaraldehyde as crosslinker has further improved the tensile property of chitosan films. However, the incorporation of CNC and glutaraldehyde has a negative effect on the elongation at break of the films due to restricted polymer chain mobility. Besides, the addition of CNC also enhanced the melting temperature of the chitosan films. The crosslinking process has further increased the melting temperature to 112.8°C with the addition of 5 wt% CNC. Therefore, the crosslinked CNC/chitosan films display greater property reinforcements than non-crosslinked films.
Synthesis and Characterizations of Fe3O4 Added with Al2O3 Nanoparticles via Sol-Gel Technique
Authors: Mohd Şuan MohdShahadan , Chin Chew Ke , Razak Jeefferie Abd , Hasib Hazman , Abid MohdAsyadi ‘Azam Mohd , Nurdin Irwan
Published: November 2020

A single step sol-gel has been established as a new route for synthesizing AkCb-added Fe3O4 nanoparticles. In this work, the effects of Al2O3 composition towards the micro structure and magnetic properties of AkCb-added Fe3O4 samples were investigated. A series of Fe and Al nitrate mixture solutions were prepared by varying the Al nitrate composition from 2.0 wt. % to 10.0 wt. %. A dropwise of propylene oxide has dimed out the clear red mixture solution with a significant release of heat before turned into a gel. The gel was dried at 90 °C for 48 h in a ventilated oven which then pulverized into a powder by using mortar grinder. The powder was calcinated at 900 °C for 1 h in a normal furnace atmosphere. The XRD results revealed that the existence of polycrystalline Fe3O4 were completed at calcination temperature 900 °C. The SEM images of the Fe3O4 with 10.0 wt.% of Al2O3 samples showed a distinct nanoparticles micro structure due to the increased of Fe3O4 nucleation initiated by Al2O3 nanoparticles. The Vickers microhardness of the Al2O3 added Fe3O4 samples were significantly increased as the Al2O3 content was increased up to 10.0 wt.% attributed from good distribution of Al2O3 nanoparticles in the sample. Subsequently, the magnetic properties of Fe3O4 investigated by alternating gradient magnetometer, AGM was insignificantly reduced by the addition of Al2O3 nanoparticles. This work indicated that the sol-gel reaction is an effective method to achieve uniform distribution and high purity of AkCb-added Fe3O4 nanoparticles with optimum microhardness and ferromagnetic performances.
A Recent blend of thermoplastic polyurethane (TPU)
Authors: Ahad Nor Azwin
Published: November 2020

Polymer blending is a well-developed manufacturing process with features of efficient production, ease of processing and good controllability. It can effectively modify and adjust the properties of polymer in order to have greater mechanical, thermal and physical properties, and thus has been commonly used to make functional polymer materials. However, the differences in polarity as well as poor interfacial between each polymer in the blend will promote the difference in polarity between the immiscible and incompatible polymers, and then the blends did not succeed as a good blend. The blending of thermoplastic polyurethane (TPU) with other polymer has been widely study with focus on the improvement of mechanical properties, wear resistance, thermal stability, toughness and other related properties. This review only focuses on the latest studies on blending TPU with other polymer, just in the range of 3 years from 2017 to 2019.
Bonding and Phases Analysis of Geopolymer Materials
Authors: Azhar Nor Shida Dalila Mohd , Zainal Farah Farhana , Abdullah Mohd Mustafa Al Bakri
Published: November 2020

This paper presents the bondings and mineral phases exist in geopolymer material consist of raw fly ash, raw metakaolin and also fly ash and metakaolin blend geopolymer. Fly ash used is a waste materials from Lumut power plant by combusting coal while metakaolin was obtained by calcining the kaolin at 750 °C for 4 hours. Alkaline activators that act as binder were sodium silicate (Na2SiO3) solution and sodium hydroxide (NaOH) solution with the ratio of Na2SiO3/NaOH is 2.5 to 1. The samples undergo Functional Group Identification (FTIR) and Phase Analysis (XRD). FTIR results show that after geopolymerization process, the band shifted to lower wavenumber (776 cm−1 ) due to interaction of Al atoms in the silicate geopolymer network because of higher cross-linking. XRD results show mineral phases of quartz and mullite in geopolymer after geopolymerization process and it can be said that not all mineral phases from raw material participating in formation of geopolymer matrix.
The Effect of Sodium Hydroxide (NaOH) Solution Concentration on Properties of Geopolymer Paste
Authors: Zainal Farah Farhana , Sulotoha Nurqistina , Daud Yusrina Mat , Hashim Mohammad Firdaus Abu , Hasri  , Hartati
Published: November 2020

This research analyzes the effect of sodium hydroxide (NaOH) solution concentration ranging from 8M to 12M as alkaline activator on the properties of geopolymer paste. Alkaline activator is essentially a mixture of sodium hydroxide and sodium silicate solution. In this research, the main component used was raw kaolin. In order to produce kaolin based geopolymer paste, the alkaline activator solution was prepared with 0.24:1.00 ratio of Na2SiO3/NaOH and this alkaline activator solution was prepared for 24 hours prior before used in another process. The solid-to-liquid ratio which is kaolin-to alkaline activator solution ratio was 0.80:1.00. The mixture of kaolin based geopolymer paste were placed in cube moulds with a size of 50x50x50 mm, and left for 24 hours until it hardened. Then, the samples were cured at 80? in the oven for 24 hours. The samples of kaolin based geopolymer paste were tested based on compressive strength, morphology analysis, water absorption and porosity after 28 days. In this project, 8M concentration of NaOH solution was the best concentration in order to study the synthesis of kaolin based geopolymer paste as the sample had the highest amount of compressive strength with 0.992 MPa and had the lowest water absorption and porosity with 1.246% and 24.08% respectively. Scanning Electron Microscope (SEM) was used to observe the morphological structure of the kaolin based geopolymer paste. The sample with 8M concentration of NaOH solution shows that least amount of unreacted particles. The structure of kaolin based geopolymer paste was more dense at 8M concentration as the size of pore decreases. The kaolin based geopolymer paste is suitable for use in the construction building industry as a finishing product such as coating.
Thermal behaviour and microstructural analysis of Sn-40Pb alloy and Sn-40Pb soldered on electroless nickel/immersion gold
Authors: Teoh Ai Ling , Salleh Mohd Arif Anuar Mohd , Halin Dewi Suriyani Che , Foo Kai Loong
Published: November 2020

Due to the toxicity of lead solder, the lead-free solder has been developing and improved in order to replace the lead solder. However, the behaviour and properties of lead solder is still better than the lead-free solder, especially in application when soldering on substrate. Hence, a common lead solder, Sn-40Pb is studied in this research by comparing with Sn-40Pb soldering on electroless nickel/immersion gold (ENIG) substrate. The thermal behaviour by differential scanning calorimeter (DSC) and microstructure formation with elemental analysis by scanning electron microscope (SEM) were carried out for Sn-40Pb solder alloy and Sn-40Pb soldered on ENIG substrate in this study. The result showed that the pasty range of Sn-40Pb was lower than Sn-40Pb/ENIG while the undercooling was higher. The diffusion and dissolution of Ni and Cu elements from ENIG substrate into the solder, forming the lead-rich phase with Ni elements and interfacial (Cu,Ni)6Sn5 with Pb elements in Sn-40Pb/ENIG. The diffusion and dissolution of elements from substrate into the solder affects the thermal behaviour and microstructural of solder.
Grassmann semialgebras and the Cayley-Hamilton theorem
Authors: Gatto Letterio , Rowen Louis
Published: November 2020

We develop a theory of Grassmann semialgebra triples using Hasse-Schmidt derivations, which formally generalizes results such as the Cayley-Hamilton theorem in linear algebra, thereby providing a unified approach to classical linear algebra and tropical algebra.
Identification of new OPA1 cleavage site reveals that short isoforms regulate mitochondrial fusion
Authors: Wang Ruohan , Mishra Prashant , Garbis Spiros D. , Moradian Annie , Sweredoski Michael J. , Chan David C.
Published: November 2020

OPA1 is a dynamin-family GTPase that is the central mediator of mitochondrial inner membrane fusion. The Opa1 gene generates both long and short isoforms (l-OPA1 and s-OPA1) through proteolytic processing. We identify a new s-OPA1 and show that it functions with l-OPA1 to tune the level of mitochondrial fusion.
High-Risk Human Papillomavirus Testing, Genotyping, and Histopathologic Follow-up in Women With Abnormal Glandular Cells on Papanicolaou Tests
Authors: Zuo Tao , Levi Angelique W , Lin Qiongqiong , Abi-Raad Rita , Adeniran Adebowale J , Cai Guoping
Published: November 2020

Objectives

This study examined the association of high-risk human papillomavirus (hrHPV) status and HPV genotype with histopathologic follow-ups in women with an atypical glandular cell (AGC) interpretation.

Methods

Cases with AGC interpretation on a Papanicolaou (Pap) test were retrieved along with hrHPV testing, genotyping, and histologic follow-up results if available.

Results

A total of 561 AGC cases were identified, with histologic follow-up available for 471 cases (84%). The follow-up diagnoses included benign or reactive changes (60% of cases), low-grade cervical intraepithelial neoplasia (18%), high-grade cervical intraepithelial neoplasia (CIN2-3; 7%), cervical carcinoma (5%), and other malignancies (10%). Tests for hrHPV were positive in 128 of 426 (30%) cases, including HPV16 (30%), HPV18 (14%) and other HPV subtypes (56%). A positive hrHPV result significantly increased the risk of developing CIN2-3 or cervical carcinoma (odds ratio, 24.6; 95% CI, 9.9-58.9) and HPV16 or HPV18 further increased the risk (odds ratio, 49.5; 95% CI, 17.7-123.7).

Conclusions

Our data demonstrate that in women with an AGC Pap interpretation, a positive hrHPV result, especially type 16 or 18, is associated with an increased risk of developing cervical CIN2-3 or higher lesions, suggesting potential implications of hrHPV testing for the management of patients with an AGC result on a Pap test.
Predicting Nash equilibria for microbial metabolic interactions
Authors: Cai Jingyi , Tan Tianwei , Chan Siu H J
Published: November 2020

Motivation

Microbial metabolic interactions impact ecosystems, human health and biotechnology profoundly. However, their determination remains elusive, invoking an urgent need for predictive models seamlessly integrating metabolism with evolutionary principles that shape community interactions.

Results

Inspired by the evolutionary game theory, we formulated a bi-level optimization framework termed NECom for which any feasible solutions are Nash equilibria of microbial community metabolic models with/without an outer-level (community) objective function. Distinct from discrete matrix games, NECom models the continuous interdependent strategy space of metabolic fluxes. We showed that NECom successfully predicted several classical games in the context of metabolic interactions that were falsely or incompletely predicted by existing methods, including prisoner’s dilemma, snowdrift and cooperation. The improved capability originates from the novel formulation to prevent ‘forced altruism’ hidden in previous static algorithms while allowing for sensing all potential metabolite exchanges to determine evolutionarily favorable interactions between members, a feature missing in dynamic methods. The results provided insights into why mutualism is favorable despite seemingly costly cross-feeding metabolites and demonstrated similarities and differences between games in the continuous metabolic flux space and matrix games. NECom was then applied to a reported algae-yeast co-culture system that shares typical cross-feeding features of lichen, a model system of mutualism. 488 growth conditions corresponding to 3221 experimental data points were simulated. Without training any parameters using the data, NECom is more predictive of species’ growth rates given uptake rates compared with flux balance analysis with an overall 63.5% and 81.7% reduction in root-mean-square error for the two species respectively.

Availability and implementation

Simulation code and data are available at https://github.com/Jingyi-Cai/NECom.git.

Supplementary information

Supplementary data are available at Bioinformatics online.
On the validity of the planar wave approximation to compute synthetic seismograms of teleseismic body waves in a 3-D regional model
Authors: Monteiller Vadim , Beller Stephen , Plazolles Bastien , Chevrot Sébastien
Published: November 2020

Injection methods are a very efficient means to compute synthetic seismograms of short-period teleseismic body waves in 3-D regional models. The principle is to inject an incident teleseismic wavefield inside a regional 3-D Cartesian spectral-element grid. We have developed an opern-source package that allows us to inject either an incident plane wave, computed with a frequency–wavenumber method, or the complete wavefield, computed in a spherically symmetric reference earth model with AxiSEM. The computations inside the regional spectral-element grid are performed with SPECFEM3D_Cartesian. We compare the efficiency and reliability of the two injection methods for teleseismic P waves, considering a wide range of epicentral distance and hypocentral depths. Our simulations demonstrate that in practice the effects of wave front and Earth curvature are negligible for moderate size regional domains (several hundreds of kilometres) and for periods larger than 2 s. The main differences observed in synthetic seismograms are related to secondary phases that have a different slowness from the one of the reference P phase.
Engineering CGTase to improve synthesis of alkyl glycosides
Authors: Ara Kazi Zubaida Gulshan , Linares-Pastén Javier A , Jönsson Jonas , Viloria-Cols Maria , Ulvenlund Stefan , Adlercreutz Patrick , Karlsson Eva Nordberg
Published: November 2020

Alkyl glycoside surfactants with elongated carbohydrate chains are useful in different applications due to their improved biocompatibility. Cyclodextrin glucanotransferases can catalyze the elongation process through the coupling reaction. However, due to the presence of a hydrophobic tail, the interaction between an alkyl glycoside acceptor and the active site residues is weaker than the interaction with maltooligosaccharides at the corresponding site. Here we report the mutations of F197, G263 and E266 near the acceptor subsites in the CGTase CspCGT13 from Carboxydocella sp. The results showed that substitutions of both F197 and G263 were important for the binding of acceptor substrate dodecyl maltoside during coupling reaction. The double mutant F197Y/G263A showed enhanced coupling activity and displayed a 2-fold increase of the primary coupling product using γ-cyclodextrin as donor when compared to wildtype CspCGT13. Disproportionation activity was also reduced, which was also the case for another double mutant (F197Y/E266A) that however not showed the corresponding increase in coupling. A triple mutant F197Y/G263A/E266A maintained the increase in primary coupling product (1.8-fold increase) using dodecyl maltoside as acceptor, but disproportionation was approximately at the same level as in the double mutants. In addition, hydrolysis of starch was slightly increased by the F197Y and G263A substitutions, indicating that interactions at both positions influenced the selectivity between glycosyl and alkyl moieties.
Community health worker models in South Africa: a qualitative study on policy implementation of the 2018/19 revised framework
Authors: Murphy Joshua P , Moolla Aneesa , Kgowedi Sharon , Mongwenyana Constance , Mngadi Sithabile , Ngcobo Nkosinathi , Miot Jacqui , Evans Denise , Pascoe Sophie
Published: November 2020

South Africa has a long history of community health workers (CHWs). It has been a journey that has required balancing constrained resources and competing priorities. CHWs form a bridge between communities and healthcare service provision within health facilities and act as the cornerstone of South Africa’s Ward-Based Primary Healthcare Outreach Teams. This study aimed to document the CHW policy implementation landscape across six provinces in South Africa and explore the reasons for local adaptation of CHW models and to identify potential barriers and facilitators to implementation of the revised framework to help guide and inform future planning. We conducted a qualitative study among a sample of Department of Health Managers at the National, Provincial and District level, healthcare providers, implementing partners [including non-governmental organizations (NGOs) who worked with CHWs] and CHWs themselves. Data were collected between April 2018 and December 2018. We conducted 65 in-depth interviews (IDIs) with healthcare providers, managers and experts familiar with CHW work and nine focus group discussions (FGDs) with 101 CHWs. We present (i) current models of CHW policy implementation across South Africa, (ii) facilitators, (iii) barriers to CHW programme implementation and (iv) respondents’ recommendations on how the CHW programme can be improved. We chronicled the differences in NGO involvement, the common facilitators of purpose and passion in the CHWs’ work and the multitude of barriers and resource limitations CHWs must work under. We found that models of implementation vary greatly and that adaptability is an important aspect of successful implementation under resource constraints. Our findings largely aligned to existing research but included an evaluation of districts/provinces that had not previously been explored together. CHWs continue to promote health and link their communities to healthcare facilities, in spite of lack of permanent employment, limited resources, such as uniforms, and low wages.
SARS-CoV-2–Specific Neutralizing Antibody Responses in Norwegian Health Care Workers After the First Wave of COVID-19 Pandemic: A Prospective Cohort Study
Authors: Trieu Mai-Chi , Bansal Amit , Madsen Anders , Zhou Fan , Sævik Marianne , Vahokoski Juha , Brokstad Karl Albert , Krammer Florian , Tøndel Camilla , Mohn Kristin G I , Blomberg Bjørn , Langeland Nina , Cox Rebecca J ,   Bergen COVID-19 Research Group, Kittang Bård , Linchausen Dagrunn Waag , Amdam Håkon , Onyango Therese Bredholt , Bredholt Geir , Ertesvåg Nina , Lartey Sarah , Sandnes Helene Heitmann , Grøvan Fredrik , Bartsch Hauke , Syre Heidi , Real Francisco , Berg Åse Garløv
Published: November 2020

Background

During the coronavirus disease 2019 (COVID-19) pandemic, many countries experienced infection in health care workers (HCW) due to overburdened health care systems. Whether infected HCW acquire protective immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear.

Methods

In a Norwegian prospective cohort study, we enrolled 607 HCW before and after the first COVID-19 wave. Exposure history, COVID-19–like symptoms, and serum samples were collected. SARS-CoV-2–specific antibodies were characterized by spike-protein IgG/IgM/IgA enzyme-linked immunosorbent and live-virus neutralization assays.

Results

Spike-specific IgG/IgM/IgA antibodies increased after the first wave in HCW with, but not in HCW without, COVID-19 patient exposure. Thirty-two HCW (5.3%) had spike-specific antibodies (11 seroconverted with ≥4-fold increase, 21 were seropositive at baseline). Neutralizing antibodies were found in 11 HCW that seroconverted, of whom 4 (36.4%) were asymptomatic. Ninety-seven HCW were tested by reverse transcriptase polymerase chain reaction (RT-PCR) during follow-up; 8 were positive (7 seroconverted, 1 had undetectable antibodies).

Conclusions

We found increases in SARS-CoV-2 neutralizing antibodies in infected HCW, especially after COVID-19 patient exposure. Our data show a low number of SARS-CoV-2–seropositive HCW in a low-prevalence setting; however, the proportion of seropositivity was higher than RT-PCR positivity, highlighting the importance of antibody testing.
Rifabutin pharmacokinetics and safety among TB/HIV-coinfected children receiving lopinavir/ritonavir-containing second-line ART
Authors: Rawizza Holly E , Oladokun Regina , Ejeliogu Emeka , Oguche Stephen , Ogunbosi Babatunde O , Agbaji Oche , Odaibo Georgina , Imade Godwin , Olaleye David , Wiesner Lubbe , Darin Kristin M , Okonkwo Prosper , Kanki Phyllis J , Scarsi Kimberly K , McIlleron Helen M
Published: November 2020

Background

Treatment options are limited for TB/HIV-coinfected children who require PI-based ART. Rifabutin is the preferred rifamycin for adults on PIs, but the one study evaluating rifabutin with PIs among children was stopped early due to severe neutropenia.

Methods

We evaluated rifabutin safety and plasma pharmacokinetics among coinfected children 3–15 years of age receiving rifabutin 2.5 mg/kg daily with standard doses of lopinavir/ritonavir. The AUC0–24 at 2, 4 and 8 weeks after rifabutin initiation was described using intensive sampling and non-compartmental analysis. Clinical and laboratory toxicities were intensively monitored at 12 visits throughout the study.

Results

Among 15 children with median (IQR) age 13.1 (10.9–14.0) years and weight 25.5 (22.3–30.5) kg, the median (IQR) rifabutin AUC0–24 was 5.21 (4.38–6.60) μg·h/mL. Four participants had AUC0–24 below 3.8 μg·h/mL (a target for the population average exposure) at week 2 and all had AUC0–24 higher than 3.8 μg·h/mL at the 4 and 8 week visits. Of 506 laboratory evaluations during rifabutin, grade 3 and grade 4 abnormalities occurred in 16 (3%) and 2 (0.4%) instances, respectively, involving 9 (60%) children. Specifically, grade 3 (n = 4) and grade 4 (n = 1) neutropenia resolved without treatment interruption or clinical sequelae in all patients. One child died at week 4 of HIV-related complications.

Conclusions

In children, rifabutin 2.5 mg/kg daily achieved AUC0–24 comparable to adults and favourable HIV and TB treatment outcomes were observed. Severe neutropenia was relatively uncommon and improved with ongoing rifabutin therapy. These data support the use of rifabutin for TB/HIV-coinfected children who require lopinavir/ritonavir.
Too Much or Too Little Messaging? Situational Determinants of Guilt About Mobile Messaging
Authors: Halfmann Annabell , Meier Adrian , Reinecke Leonard
Published: November 2020

Mobile messaging has been associated with guilt. Guilt about too much messaging may result from self-control failures during goal conflicts. Conversely, guilt about too little messaging may result from violating the salient norm to be available. This research considers both boundary conditions of guilt about mobile communication—goal conflicts and availability norm salience—simultaneously for the first time. We conducted two preregistered experiments to investigate their interplay. Results from a vignette experiment, but not from a laboratory experiment, support the hypotheses that goal conflicts trigger guilt about using messengers and that guilt about not using messengers arises if the availability norm is salient. In both studies, using messengers elicited more guilt than not using messengers. The boundary conditions did not interact in influencing guilt. Overall, this research emphasizes the importance of self-control, norms, and usage contexts when studying effects of mobile media use on emotional well-being.
Differences in Bifenthrin and Fipronil Susceptibility Among Invasive Latrodectus spp. (Araneae: Theridiidae) and Nontarget Spiders in Japan
Authors: Hayasaka Daisuke , Numa Tomoki , Sawahata Takuo
Published: November 2020

Prompt responses to invasive Latrodectus spiders introduced unintentionally are needed worldwide due to their medical and ecological importance. Latrodectus species are chemically controlled using pyrethroid insecticides despite concerns about the ecological impacts of these compounds on biodiversity/ecosystems. Here, the relative sensitivities (acute toxicity: 48-h LC50) of Latrodectus hasseltii Thorell and Latrodectus geometricus C.L. Koch from Japan to the conventional neurotoxic insecticide bifenthrin (pyrethroid) and a new candidate insecticide, fipronil (phenylpyrazole), were examined. Acute residual toxicity tests of these compounds in two nontarget spiders (Parasteatoda tepidariorum C.L. Koch (Araneae: Theridiidae), Badumna insignis L. Koch (Araneae: Desidae)) were conducted for comparison. To test whether bifenthrin and fipronil toxicities differed among the four spiders, corresponding species sensitivity distributions (SSDs) were compared, and hazardous concentrations were determined. Sensitivity (especially in the nontarget species) was two to four orders of magnitude higher for bifenthrin than for fipronil. The SSD patterns of the two insecticides differed significantly, with the spider communities being more sensitive to bifenthrin than to fipronil. The lethal bifenthrin concentration for Latrodectus may reduce spider populations by over 70–90%. If L. hasseltii (established throughout Japan) is targeted for effective population suppression rather than L. geometricus (with a limited distribution range) using the specified insecticide concentration (LC50 value) for fipronil, less than 20% of spider communities will be impacted. Chemical operations aimed at the effective population management and subsequent eradication of invasive Latrodectus spiders while supporting local biodiversity conservation would benefit from considerations of fipronil dosages and target species sensitivities.
Prolonged growth during the food-restricted dry season in a small African mammal
Authors: Rimbach Rebecca , Pillay Neville , Schradin Carsten
Published: November 2020

Studying how different environmental parameters, such as resource availability and ambient temperature, affect growth rates aids to understand the evolution of different growth strategies. Low levels of food availability restrict growth, and high ambient temperature can constrain growth via trade-offs between body temperature maintenance and heat produced during digestion. We studied growth of African striped mice (Rhabdomys pumilio), a small mammal living in a seasonally arid habitat. Striped mice are born during spring with high food availability and low ambient temperature, and typically enter the food-restricted dry season before reaching adulthood. We predicted low food availability and high ambient temperature would negatively affect growth. We therefore expected an extended period of slow growth during the long dry season. We repeatedly measured body length of 369 free-living individuals, examined how ambient temperature and food availability influenced growth rate, and seasonal changes in growth rate. In addition, we investigated whether mice (N = 27) born in summer (atypical breeding season) have slower growth rates than those born in spring. Growth rate increased with increasing food availability and decreased with increasing ambient temperature. Individuals born in summer grew slower than those born in spring. Sexes reached asymptotic body length at 258 days (females) and 285 days (males), which is an unusually long growth period compared with other small rodents. As most striped mice live for less than 1 year, this period encompasses the entire life for most individuals, but stops at old age, which could indicate senescence. Our results demonstrate a positive influence of food availability on growth, a relationship mediated by ambient temperature. We conclude that striped mice enter the food-restricted dry season before postnatal growth is terminated, and early exposure to harsh environmental conditions during the long dry season likely explains the prolonged growth period in striped mice.
Solar wind temperature–velocity relationship over the last five solar cycles and Forbush decreases associated with different types of interplanetary disturbance
Authors: Melkumyan A A , Belov A V , Abunina M A , Abunin A A , Eroshenko E A , Yanke V G , Oleneva V A
Published: November 2020

The behaviour of the solar wind (SW) proton temperature and velocity and their relationship during Forbush decreases (FDs) associated with various types of solar source – coronal mass ejections (CMEs) and coronal holes (CHs) – have been studied. Analysis of cosmic ray variations, SW temperature, velocity, density, plasma beta, and magnetic field (from 1965–2019) is carried out using three databases: the OMNI database, Variations of Cosmic Rays database (IZMIRAN) and Forbush Effects & Interplanetary Disturbances database (IZMIRAN). Comparison of the observed SW temperature (T) and velocity (V) for the undisturbed SW allows us to derive a formula for the expected SW temperature (Texp, the temperature given by a T–V formula, if V is the observed SW speed). The results reveal a power-law T–V dependence with a steeper slope for low speeds (V < 425 km s−1, exponent = 3.29 ± 0.02) and flatter slope for high speeds (V > 425 km s−1, exponent = 2.25 ± 0.02). A study of changes in the T–V dependence over the last five solar cycles finds that this dependence varies with solar activity. The calculated temperature index KT = T/Texp can be used as an indicator of interplanetary and solar sources of FDs. It usually has abnormally large values in interaction regions of different-speed SW streams and abnormally low values inside magnetic clouds (MCs). The results obtained help us to identify the different kinds of interplanetary disturbance: interplanetary CMEs, sheaths, MCs, corotating interaction regions, high-speed streams from CHs, and mixed events.
New radial velocity observations of AH Her: evidence for material outside the tidal radius
Authors: Echevarría J , Hernández Santisteban J V , Segura Montero O , Ramírez S H , Ruelas-Mayorga A , Sánchez L J , Michel R , Costero R , González-Buitrago D H , Olivares J
Published: November 2020

Spectroscopic observations of AH Herculis during a deep quiescent state are put forward. We found the object in a rare long minima, allowing us to derive accurately the semi-amplitudes: $K_1 =121 \pm \, 4$ km s−1 and K2 = 152 ± 2 km s−1 and its mass functions MWsin 3i = 0.30 ± 0.01 M⊙ and MRsin 3i = 0.24 ± 0.02 M⊙, while its binary separation is given by asin i = 1.39 ± 0.02 R⊙. The orbital period Porb =  0.25812 ± 0.00032 d was found from a power spectrum analysis of the radial velocities of the secondary star. These values are consistent with those determined by Horne, Wade & Szkody. Our observations indicate that K5 is the most likely spectral type of the secondary. We discuss why we favour the assumption that the donor in AH Her is a slightly evolved star, in which case we find that the best solution for the inclination yields i = 48° ± 2°. None the less, should the donor be a ZAMS star, we obtain that the inclination is between i = 43° and i = 44°. We also present Doppler tomography of H α and H β, and found that the emission in both lines is concentrated in a large asymmetric region at low velocities, but at an opposite position to the secondary star, outside the tidal radius and therefore at an unstable position. We also analyse the H α and H β line profiles, which show a single broad peak and compare it with the previous quiescent state study that shows a double-peaked profile, providing evidence for its transient nature.
The effect of impact parameter on tidal disruption events
Authors: Spaulding Alexandra , Chang Philip
Published: November 2020

Stars that pass too close to a supermassive black hole are disrupted by the black hole’s tidal gravity. Some debris is ejected while the remainder accretes into the black hole. To better study the physics of these debris, we use the moving mesh code manga to follow the evolution of the star from its initial encounter to its complete destruction. By varying the impact parameter (β) of the star, we study the energy distribution of the remaining material and the fallback rate of the material into the black hole as a function of time. We show that the spread of energy in the debris and peak luminosity time (tpeak) are both directly related to the impact parameter. In particular, we find a β1/2 scaling for the energy spread for β = 2 − 10 that levels off at β ≳ 10. We discuss implication of this scaling for the rise time of the light curve and broadness of the luminosity peak for these lower β’s. These relationships provide a possible means of inferring the impact parameters for observed tidal disruption events.
3D spectroscopic analysis of helium-line white dwarfs
Authors: Cukanovaite Elena , Tremblay Pier-Emmanuel , Bergeron Pierre , Freytag Bernd , Ludwig Hans-Günter , Steffen Matthias
Published: November 2020

In this paper, we present corrections to the spectroscopic parameters of DB and DBA white dwarfs with −10.0 ≤ log (H/He) ≤ −2.0, 7.5 ≤ log g ≤ 9.0, and $12\, 000$ ≲ Teff $\lesssim 34\, 000\,\mathrm{ K}$, based on 282 3D atmospheric models calculated with the co5bold radiation-hydrodynamics code. These corrections arise due to a better physical treatment of convective energy transport in 3D models when compared to the previously available 1D model atmospheres. By applying the corrections to an existing Sloan Digital Sky Survey (SDSS) sample of DB and DBA white dwarfs, we find significant corrections both for effective temperature and surface gravity. The 3D log g corrections are most significant for Teff ≲ 18 000 K, reaching up to −0.20 dex at log g = 8.0. However, in this low effective temperature range, the surface gravity determined from the spectroscopic technique can also be significantly affected by the treatment of the neutral van der Waals line broadening of helium and by non-ideal effects due to the perturbation of helium by neutral atoms. Thus, by removing uncertainties due to 1D convection, our work showcases the need for improved description of microphysics for DB and DBA model atmospheres. Overall, we find that our 3D spectroscopic parameters for the SDSS sample are generally in agreement with Gaia Data Release 2 absolute fluxes within 1σ–3σ for individual white dwarfs. By comparing our results to DA white dwarfs, we determine that the precision and accuracy of DB/DBA atmospheric models are similar. For ease of user application of the correction functions, we provide an example python code.
Rapid CO gas dispersal from NO Lup’s class III circumstellar disc
Authors: Lovell J B , Kennedy G M , Marino S , Wyatt M C , Ansdell M , Kama M , Manara C F , Matrà L , Rosotti G , Tazzari M , Testi L , Williams J P
Published: November 2020

We observed the K7 class III star NO Lup in an ALMA survey of the 1–3 Myr Lupus association and detected circumstellar dust and CO gas. Here we show that the J = 3–2 CO emission is both spectrally and spatially resolved, with a broad velocity width ∼19 km s−1 for its resolved size ∼1 arcsec (∼130 au). We model the gas emission as a Keplerian disc, finding consistency, but only with a central mass of ∼11M⊙, which is implausible given its spectral type and X-Shooter spectrum. A good fit to the data can also be found by modelling the CO emission as outflowing gas with a radial velocity ∼22 km s−1. We interpret NO Lup’s CO emission as the first imaged class III circumstellar disc with outflowing gas. We conclude that the CO is continually replenished, but cannot say if this is from the breakup of icy planetesimals or from the last remnants of the protoplanetary disc. We suggest further work to explore the origin of this CO, and its higher than expected velocity in comparison to photoevaporative models.
Interactions between the land snails Theba pisana and Cernuella virgata in the laboratory
Authors: Baker Geoff H
Published: November 2020

Two Mediterranean snails, Theba pisana and Cernuella virgata, are agricultural pests in southern Australia. The two species are rarely found together in large numbers in the field, at small scales (<1 m2). In laboratory experiments, the presence of T. pisana reduced the survival of C. virgata, but only when food (carrot + lettuce) was provided. When C. virgata was exposed to only the mucus trails and faeces of T. pisana, produced while feeding on lettuce, both the survival and activity of C. virgata were reduced. When carrot was substituted for lettuce, there was less effect. In addition, when C. virgata was exposed to T. pisana’s faeces only, derived from access to a mix of lettuce and carrot, there was no effect on C. virgata’s survival. The observed reductions in the survival of C. virgata were stronger in autumn (the breeding season for both snail species) compared with spring. Inhibitory components within the mucus trails of T. pisana may (1) help explain the observed distribution patterns of the two species at small scales in the field and (2) provide a novel method for control of pest populations of C. virgata, in some situations.
Deploying MMEJ using MENdel in precision gene editing applications for gene therapy and functional genomics
Authors: Martínez-Gálvez Gabriel , Joshi Parnal , Friedberg Iddo , Manduca Armando , Ekker Stephen C
Published: November 2020

Gene-editing experiments commonly elicit the error-prone non-homologous end joining for DNA double-strand break (DSB) repair. Microhomology-mediated end joining (MMEJ) can generate more predictable outcomes for functional genomic and somatic therapeutic applications. We compared three DSB repair prediction algorithms – MENTHU, inDelphi, and Lindel – in identifying MMEJ-repaired, homogeneous genotypes (PreMAs) in an independent dataset of 5,885 distinct Cas9-mediated mouse embryonic stem cell DSB repair events. MENTHU correctly identified 46% of all PreMAs available, a ∼2- and ∼60-fold sensitivity increase compared to inDelphi and Lindel, respectively. In contrast, only Lindel correctly predicted predominant single-base insertions. We report the new algorithm MENdel, a combination of MENTHU and Lindel, that achieves the most predictive coverage of homogeneous out-of-frame mutations in this large dataset. We then estimated the frequency of Cas9-targetable homogeneous frameshift-inducing DSBs in vertebrate coding regions for gene discovery using MENdel. 47 out of 54 genes (87%) contained at least one early frameshift-inducing DSB and 49 out of 54 (91%) did so when also considering Cas12a-mediated deletions. We suggest that the use of MENdel helps researchers use MMEJ at scale for reverse genetics screenings and with sufficient intra-gene density rates to be viable for nearly all loss-of-function based gene editing therapeutic applications.
Spetzler-Martin Grade III Arteriovenous Malformations: A Multicenter Propensity-Adjusted Analysis of the Effects of Preoperative Embolization
Authors: Catapano Joshua S , Frisoli Fabio A , Nguyen Candice L , Wilkinson D Andrew , Majmundar Neil , Cole Tyler S , Baranoski Jacob F , Whiting Alexander C , Kim Helen , Ducruet Andrew F , Albuquerque Felipe C , Cooke Daniel L , Spetzler Robert F , Lawton Michael T
Published: November 2020

BACKGROUND

Spetzler-Martin (SM) grade III arteriovenous malformations (AVMs) are at the boundary of safe operability, and preoperative embolization may reduce surgical risks.

OBJECTIVE

To evaluate the benefits of preoperative AVM embolization by comparing neurological outcomes in patients with grade III AVMs treated with or without preoperative embolization.

METHODS

All microsurgically treated grade III AVMs were identified from 2011 to 2018 at 2 medical centers. Neurological outcomes, measured as final modified Rankin Scale scores (mRS) and changes in mRS from preoperative baseline to last follow-up evaluation, were compared in patients with and without preoperative embolization.

RESULTS

Of the 102 patients with grade III AVMs who were treated microsurgically, 57 (56%) underwent preoperative embolization. Significant differences were found between the patients with and without embolization in AVM eloquence (74% vs 93%, P = .02), size ≥ 3 cm (47% vs 73%, P = .01), diffuseness (7% vs 22%, P = .04), and mean final mRS (1.1 vs 2.0, P = .005). Poor outcomes were more frequent in patients without embolization (38%) than with embolization (7%) (final mRS > 2; P < .001). Propensity-adjusted analysis revealed AVM resection without embolization was a risk factor for poor outcome (mRS score > 2; odds ratio, 4.2; 95% CI, 1.1-16; P = .03).

CONCLUSION

Nonembolization of SM grade III AVMs is associated with an increased risk of poor neurological outcomes after microsurgical resection. Preoperative embolization of intermediate-grade AVMs selected because of large AVM size, surgical inaccessibility of feeding arteries, and high flow should be employed more often than anticipated, even in the context of increasing microsurgical experience with AVMs.
Beyond adverse outcome pathways: making toxicity predictions from event networks, SAR models, data and knowledge
Authors: Ball Thomas , Barber Christopher G , Cayley Alex , Chilton Martyn L , Foster Robert , Fowkes Adrian , Heghes Crina , Hill Emma , Hill Natasha , Kane Steven , Macmillan Donna S , Myden Alun , Newman Daniel , Polit Artur , Stalford Susanne A , Vessey Jonathan D
Published: November 2020

Adverse outcome pathways have shown themselves to be useful ways of understanding and expressing knowledge about sequences of events that lead to adverse outcomes (AOs) such as toxicity. In this paper we use the building blocks of adverse outcome pathways—namely key events (KEs) and key event relationships—to construct networks which can be used to make predictions of the likelihood of AOs. The networks of KEs are augmented by data from and knowledge about assays as well as by structure activity relationship predictions linking chemical classes to the observation of KEs. These inputs are combined within a reasoning framework to produce an information-rich display of the relevant knowledge and data and predictions of AOs both in the abstract case and for individual chemicals. Illustrative examples are given for skin sensitization, reprotoxicity and non-genotoxic carcinogenicity.