bluuebunny/crossref_metadata_2025 huggingface dataset:
Parametric investigation and characterization on SS316 built by laser-assisted directed energy deposition
Authors: Benarji K , Kumar Y Ravi , Paul CP , Jinoop AN , Bindra KS
Published: December 2019

In the present work, parametric investigation and characterization of stainless steel 316 (SS316) built by laser-assisted directed energy deposition (L-DED) is performed. Single-track L-DED experiments are carried by varying laser power, scanning speed, and powder feed rate using full factorial experimental design. The effect of L-DED process parameters on the track geometry, deposition rate, and microhardness is investigated, and three different combinations of process parameters yielding maximum deposition rate and hardness are identified for bulk investigation. The identified process parameters are laser power of 1000 W, powder feed rate of 8 g/min, and scanning speed of 0.4 m/min, 0.5 m/min, and 0.6 m/min. The austenitic phase [Formula: see text] is detected at all the conditions. However, ferrite [Formula: see text] peak is observed at 0.6 m/min due to microsegregation and thermal gradients. The minimum crystallite size is estimated to be 24.88 nm at 0.6 m/min. The porosity and microstructure analysis is carried out by optical microscopic images. The fine columnar dendritic structure is observed in L-DED samples at all conditions. An average microhardness of 317.4 HV0.98 N is obtained at 0.4 m/min, and it is observed that microhardness reduces with an increase in scanning speed mainly due to increase in lack of fusion and porosity. Tribology studies are carried out at different values of normal load and sliding velocity. The minimum specific wear rate of 0.02497 × 10−4 mm3/Nm is observed at scanning speed of 0.4 m/min. Scanning electron microscope of the wear tracks analysis shows abrasive wear as the major wear mechanism. This study provides a path for building SS316 components for various engineering applications.
Damage imaging that exploits multipath scattered Lamb waves
Authors: Zeng Liang , Huang Liping , Luo Zhi , Lin Jing
Published: December 2019

This article presents a multipath Lamb wave imaging method that leverages the extra reflections present in the recorded ultrasonic waveforms for structural prognosis. Under the ray acoustic approximation, an edge behaves like a mirror, which changes the propagation path of a wave and provides more views of the damage than can be obtained from direct scattering. To accommodate for these extra reflections, the scattering path of each wave in the residual signal is simplified as a direct scattering path from an actual or virtual transmitter (created by edge mirroring) to the damage, and then back to an actual or virtual receiver (created by edge mirroring). On this basis, the Gaussian distribution function is introduced to quantify the probabilities at each spatial node in relation to all possible damage loci. Through fusing the images obtained from all individual wave packets, the structure could be inspected with far fewer transducers compared to conventional elliptical imaging. Experimental results from carbon fiber-reinforced polymer laminates and aluminum plate are provided to illustrate the effectiveness of the imaging method, where damage is correctly detected and accurately localized even with a single transmitter–receiver pair.
Prevention Is Possible: A Brief History of the Origin and Dissemination of the Icelandic Prevention Model
Authors: Sigfusdottir Inga Dora , Soriano Humberto E. , Mann Michael J. , Kristjansson Alfgeir L.
Published: December 2019

In two decades, the Icelandic prevention model (IPM) has been employed to dramatically reduce rates of adolescent substance use in Iceland. Briefly, the IPM is a multisectoral, community-based, collaborative system where researchers, policy makers, administrative leaders, and practitioners join forces to reduce the odds of adolescent substance use over time. Comparatively, Iceland now ranks among the lowest in adolescent substance use in all of Europe. Since 2005, the IPM has garnered considerable international attention, and several countries or municipalities within them have adapted, or are presently adapting, the model to their needs. In this commentary, we first briefly review the history and formation of the IPM in Iceland from a school-based survey to a fully integrated prevention system. In the second part, we present a short overview of the national consensus building and institutional collaboration that led to the implementation of the model in Chile in Latin America, as a demonstrative example. In this volume of Health Promotion Practice, we also present a series of two practice-based articles that introduce the IPM. The first article, titled “Development and Guiding Principles of the Icelandic Model for Preventing Adolescent Substance Use,” introduces the theoretical origins of the model, five guiding principles, and evidence of effectiveness to date. In the second article, titled “Implementing the Icelandic Model for Preventing Adolescent Substance Use,” we outline 10 practice-based steps to guide model implementation in other countries. Both articles are available via open access, and both are also available online in Spanish.
Investigation on antimicrobial activity and electromagnetic shielding effectiveness of metal composite single jersey fabrics
Authors: Özkan İlkan
Published: December 2019

In this study, antimicrobial and electromagnetic shielding properties of metal composite single jersey fabrics were investigated. For this purpose, stainless steel wire, copper wire, and metalized silver polyamide filament were commingled with textured polyester. The composite yarns were knitted to single jersey fabrics. Electromagnetic shielding effectiveness of samples was measured according to free space test method between 0.8 and 5.2 GHz frequency range. In addition, antibacterial and antifungal activity tests were performed for the overall technical characterization of composite fabrics. The effects of metal type, filament form on electromagnetic shielding effectiveness, and antimicrobial properties were examined. All composite fabrics showed electromagnetic shielding properties at different levels up to 35 dB in vertical direction. Fabrics including metalized multifilament yarn exhibit higher electromagnetic shielding effectiveness in both vertical and horizontal directions. In addition, antibacterial activity level of metalized silver polyamide and copper composite fabrics reached up to 99% against Klebsiella pneumoniae and Staphylococcus aureus. Furthermore, Aspergillus niger could not grow on these composite fabrics.
Effect of combined natural convection and non-gray gas radiation on entropy generation in a circular enclosure with partial heating
Authors: Jarray Khouloud , Mazgar Akram , Ben Nejma Fayçal
Published: December 2019

This article reports a numerical analysis of combined natural convection and non-gray gas radiation within a cylindrical enclosure, isothermally heated and cooled on various arc lengths of the sidewall. Three active zone locations are studied in this article. The first heating section extends quarter the perimeter of the cavity, the second spreads across one-half of the cylinder, and the third one is made of three-quarters of the sidewall. The participating media are considered as emissive, absorbent, and non-scattering. The radiative transfer equation is resolved using the Ray-Tracing method associated to the Statistical Narrow Band–correlated K model. The effect of heater size and its location on heat transfer, fluid flow, and entropy generation are presented and discussed in this work. The results show that the optimum heater size is obtained for three-quarters heated enclosure. It was also found that choosing a heat source centered at the top of the enclosure provides the best heat transfer performance.
Dynamic evaluation of elastic bar in track transition section of fast-metro system
Authors: Chen Zhaowei , Fang Hui
Published: December 2019

In China, the rapid development of fast-metro system, along with many dynamic problems in track transition section, threatens the safe operation of the metro system. Aiming at this practical issue, this article presents an evaluation on the dynamic behaviors of elastic bars in track transition section of the fast-metro system. Primarily, an effective global–local method for evaluating the performance of elastic bar is proposed based on vehicle–track-coupled dynamics, in which two important models are established, namely, the vehicle–track transition section–coupled dynamic model and the three-dimensional finite element model of elastic bar. Then, the dynamic property of elastic bar in track transition section of the fast-metro system is evaluated employing the proposed method, focusing on the fastener force, dynamic displacement of elastic bar, and stress of elastic bar. Finally, fatigue analysis is conducted to evaluate the service life of elastic bar in track transition section. Results show that the proposed global–local method is effective to evaluate the dynamic behaviors of elastic bar in track transition section in fast-metro system. Impact appears when vehicles run through the track transition section and it mainly influences the two fasteners on each side. Operational direction of vehicle has little influence on amplitude of displacement of elastic bar. When the vehicle runs at 120 km/h, maximum stress of elastic bar is 1050 MPa, which occurs inside the rear toe. From the perspective of long-term service, traditional track transition section is not suitable for fast-metro system, which should be redesigned.
Hygrothermal performance of cold ventilated attics above different horizontal ceiling constructions: Full-scale test building
Authors: Hansen Thor , Møller Eva B , Tvedebrink Torben
Published: December 2019

It is often assumed that reduced heat flux to a ventilated attic reduces the temperature and thereby increases the relative humidity. Consequently, the importance of having a tight air and vapour barrier in the ceiling becomes more important with increased insulation. Therefore, in Denmark, the recommendation is to have a tight vapour barrier when re-insulating ceilings against cold ventilated attics to a total of 150-mm insulation material. The recommendation is independent of the insulation material’s hygroscopic properties or the indoor moisture level. The aim of this project was to test the relevance of the recommendation through testing in a full-scale test building (7 × 22 m) with a series of six different ceilings with or without a vapour barrier and variation in the insulation material comprising insulation thickness and its hygroscopic properties. The examination was performed with a controlled indoor climate after an European humidity classes 1–3 and a natural outdoor climate. The study showed very little differences in temperature and relative humidity in the cold ventilated attics, while the humidity class of the indoor climate significantly affects the absolute moisture content in the attic. However, the climate in the attic did not cause mould growth in the test sections, even for humidity class 3. Consequently, in the test building the thickness or hygroscopic properties of the insulation material did not have a significant effect on the moisture level in attics and did not determine whether a vapour barrier should be installed. In this study with the given climate, a vapour barrier is unnecessary in well-ventilated attics if the ceiling is airtight.
The Big Five personality factors as predictors of English language speaking anxiety: A cross-country comparison between Morocco and South Korea
Authors: Babakhouya Youssef
Published: December 2019

This is a comparative study that examined the relationship between the Big Five personality factors and English language speaking anxiety among Moroccans ( N=270) and Koreans ( N=257), who completed the International Personality Item Pool Big Five Inventory and the English Language Speaking Anxiety Scale. The results indicate that Openness and Neuroticism were the only significant predictors of English language speaking anxiety in the two countries, noting that Openness was the strongest significant predictor in Morocco, whereas Neuroticism was the strongest significant predictor in Korea. Implications indicated that assessing the personality of students may predict those who will experience these anxieties.
Synthesis, structures, and fluorescence properties of one novel Cobalt metal–organic framework based on a tetraphenylethene-core ligand
Authors: Xu Xiudian , Liang Yu , Li Junfeng , Zhou Lei , Chen Li-Zhuang , Wang Fang-Ming
Published: December 2019

A new three-dimensional luminescent cobalt (II) metal–organic framework, [Co(Titpe)(bcpf)·(DMF)]·(H2O)2·(DMF) (compound 1, JUST-8) (Titpe = 1,1,2,2-tetrakis(4-(1H-imidazol-1-yl)phenyl)ethane, bcpf = 4,4′-sulfonyldibenzoic acid; DMF =  N, N-dimethylformamide), has been solvothermally synthesized by using CoCl2·6H2O and a mixture of ligands: Titpe ligand and bcpf ligand. Single crystal X-ray analysis reveals that 1 crystallizes in the triclinic system and [Formula: see text] space group with a = 13.2097(14) Å, b = 13.9519(14) Å, c = 14.4413(15) Å, α = 89.949(7)°, β = 70.303(7)°, γ = 80.322(7)°, V = 2465.7(5) Å3, Z = 2, Mr =1032.97, Dc = 1.391 g/cm3, μ = 0.455 mm−1, F(000) = 1070, R = 0.0585, and wR = 0.1540 for 8674 observed reflections ( I > 2σ( I)). Its overall structure is a double-fold interpenetrated framework, and it shows a porosity of 12.97% based on a calculation by PLATON and a 4- c type topological network with the point symbol of {6^5.8}. The Co atom bridges the Titpe ligands to form the one-dimensional chains into a two-dimensional layered structure and then connects the auxiliary ligands to get a three-dimensional structure. Compound 1 showed a blue fluorescence emission with the peak maximum at 431 nm (λex = 314 nm).
Remade: Sovereign: Decolonizing Guam in the age of environmental anxiety
Authors: Delgado Francisco
Published: December 2019

Linking Cultural Memory Studies, Indigenous Studies, as well as the growing field of Environmental Humanities, my article casts decolonization efforts in Guam not only as a process steeped in history, politics, and economics, but also as a necessary means to address environmental precarity. I use Craig Santos Perez’s poetry to highlight the multifaceted scope of decolonization: namely, that it entails the use of the Indigenous Chamorro language, the decolonizing of the imaginations of Chamorro people, who continue to enlist for (and die for) a nation that exploits their lands, waters, and bodies and finally the deliberate retrieval of cultural memory that promotes balance between humans and nature. Cultural memory and decolonization are thus linked. Together, they assuage the environmental impact of settler colonialism in Guam and elsewhere.
Novel presentation of eosinophilic granuloma complex in a cat
Authors: Hopke Kaitlin P , Sargent Sandra J
Published: December 2019

Case summary

A 9-year-old neutered male domestic shorthair cat was presented for multiple deep lesions on all four limbs and a nodule on the right pinna. The limb lesions ranged from nodules with necrotic surfaces to full-thickness ulcerations with exposure of muscles and tendons. The cat lived indoors only in a single-pet household and had no prior history of trauma. The owner reported that the lesions appeared abruptly and that the cat was not apparently painful or pruritic. Histopathology of the limb lesions and pinnal nodule confirmed severe lesions of the eosinophilic granuloma complex. Resolution of lesions was achieved with a combination of antibiotics, prednisolone, topical therapies, diet change and ciclosporin.

Relevance and novel information

This case report demonstrates a severe, aggressive presentation of eosinophilic granuloma complex. It will expose practitioners to atypical clinical signs of this commonly diagnosed disease.
Radiologic Contrast Media Desensitization for Delayed Cardiac Catheterization
Authors: Sanan Neha , Rowane Marija , Hostoffer Robert
Published: December 2019

This protocol for rapid desensitization to intravenous radiographic contrast material (RCM) improves the strategy first reported by Uppal et al. Desensitization is a validated preventative measure for medical emergencies, such as cardiac catheterization, when patients present with histories of anaphylactoid reactions to the allergen of concern. The patient required another catheterization that was modified to repeat the final dosage of 320 mg/mL of Visipaque®, accommodating cardiac catheterization postponement, contrary to readministration of doses 4 (0.625 mg/mL) and 8 (10 mg/mL) as reported in Uppal et al. Our risk score calculations suggested that the patient was at low risk of contrast-induced nephropathy (CIN) that did not necessitate reduced dosage. No complications were reported following catheterization. We propose repetition of the final RCM dosage as a more effective and efficient desensitization strategy, as long as the scoring system does not indicate high risk for CIN.
A STEM Achievement Motivation Program: Perspectives of Elementary School Students
Authors: Schmit Erika L. , Smith Robert L. , Ratanavivan Wannigar , Ermis-Demirtas Hulya , Rosenbaum Lorena A. , Monteiro Marta P. , Dyurich Adriana
Published: December 2019

Researchers explored the perspectives of third-grade students attending a 6-week science, technology, engineering, and mathematics (STEM) achievement motivation pilot program at a university’s early childhood development center serving a Hispanic population. Researchers obtained data from interviews, observations, and a focus group. Four major themes emerged from this phenomenological qualitative investigation. Findings support the implementation by school counselors of STEM achievement motivation programs with young students, who in this study reported an understanding of concepts presented and their application to math and science projects. The findings have implications for counselors employed in school settings.
Comparison of the Clinical Effectiveness of Single Versus Multiple Injections of Platelet-Rich Plasma in the Treatment of Knee Osteoarthritis: A Systematic Review and Meta-analysis
Authors: Vilchez-Cavazos Félix , Millán-Alanís Juan Manuel , Blázquez-Saldaña Jaime , Álvarez-Villalobos Neri , Peña-Martínez Víctor Manuel , Acosta-Olivo Carlos Alberto , Simental-Mendía Mario
Published: December 2019

Background:

Reports have concluded that platelet-rich plasma (PRP) is an effective and safe biological approach in the treatment of knee osteoarthritis (OA). However, no consensus has been established regarding the number of injections required to observe a therapeutic effect.

Purpose:

To compare the clinical effectiveness reported in randomized controlled trials (RCTs) of single versus multiple PRP injections in the treatment of knee OA.

Study Design:

Systematic review; Level of evidence, 1.

Methods:

A comprehensive search was conducted for RCTs published between 1970 and 2019 that compared the effect of single versus multiple PRP injections on pain and functionality in patients with knee OA. Searched databases included MEDLINE, Scopus, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials. A data extraction form was designed to obtain bibliographic information of the study as well as patient, intervention, comparison, and outcomes of interest data. A random-effects model was used to pool quantitative data from the primary outcomes.

Results:

We included 5 clinical trials with a low-moderate risk of bias that reported data for 301 patients. Meta-analysis showed that, at 6 months after the intervention, single and multiple (double or triple) injections had similar pain improvement, with no significant differences (standardized mean difference [SMD], 0.61 [95% CI, −1.09 to 2.31]; I 2 = 97%; P = .48). A significant improvement in knee functionality was observed in favor of multiple injections (SMD, 2.29 [95% CI, 0.45-4.12]; I 2 = 97%; P = .01). Subanalysis showed that the significant improvement was only evident for the results of single versus triple injections (SMD, 3.12 [95% CI, 0.64-5.60]; I 2 = 97%; P = .01).

Conclusion:

According to our results, a single injection was as effective as multiple PRP injections in pain improvement; however, multiple injections seemed more effective in joint functionality than a single injection at 6 months. We consider that the available evidence is still insufficient, and future research on this specific topic is needed to confirm our results.
Evaluation of In Vivo Antidiarrheal Activities of Hydroalcoholic Leaf Extract of Dodonaea viscosa L.(Sapindaceae) in Swiss Albino Mice
Authors: Abdela Jemal
Published: December 2019

Traditionally people used Dodonaea viscosa for the treatment of various ailments, including diarrhea. Therefore, this study was aimed to evaluate the antidiarrheal activity of the 80% methanolic leaf extract of D viscosa against castor oil-induced diarrhea in mice models. Different doses of 80% methanolic leaf extract of D viscosa (100, 200, and 400 mg/kg) were evaluated for their antidiarrheal activities using castor oil–induced diarrhea, gastrointestinal transit, and enteropooling models in Swiss albino mice. At all test doses, the plant extract showed significant ( P < .05) inhibition in the frequency of defecation of wet feces and total fecal output as compared to the control group. Similarly, at all dose ranges used the plant extract demonstrated significant ( P < .05) reduction in an intraluminal fluid accumulation as compared to the untreated group. Besides, at higher doses, the plant extract also indicated significant ( P < .05) antimotility activity in comparison with the control. In conclusion, these findings illustrated that the 80% methanolic leaf extract of D viscosa supported the traditional claim of antidiarrheal activity of the plant though further investigations are warranted.
Exploring the Coordination Effect of GO@MOF-5 as Catalyst on Thermal Decomposition of Ammonium Perchlorate
Authors: Wang Shuang , Ye Baoyun , An Chongwei , Wang Jingyu , Li Qianbing , Guo Hao , Zhang Jianwei
Published: December 2019

Prepared composite materials based on [Zn4O(benzene-1,4-dicarboxylate)3] (MOF-5) and graphene oxide (GO) via a simple green solvothermal method, at which GO was used as platform to load MOF-5, and applied to the thermal decomposition of AP. The obtained composites were characterized by various techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), nitrogen adsorption, Fourier transform infrared (FT-IR), differential scanning calorimetry and thermalgravimetric (DSC-TG). The analyses confirmed that the composite material (GO@) MOF-5 can not only improve the decomposition peak temperature of AP from the initial 409.7 °C to 321.9 °C, but also can improve the enthalpy (△H) from 576 J g−1 to 1011 J g−1 and reduce the activation energy (Ea), thereby accelerating the decomposition reaction. The high-specific surface area of the MOF material can provide a large number of active sites, so that the transition metal ions supported thereon can participate more effectively in the electron transfer process, and GO plays its role as a bridge by its efficient thermal and electrical conductivity. Together, accelerate the thermal decomposition process of AP.
Mitochondrial aminoacyl-tRNA synthetase disorders: an emerging group of developmental disorders of myelination
Authors: Fine Amena Smith , Nemeth Christina L. , Kaufman Miriam L. , Fatemi Ali
Published: December 2019

Background

The mitochondrial aminoacyl-tRNA synthetase proteins (mt-aaRSs) are a group of nuclear-encoded enzymes that facilitate conjugation of each of the 20 amino acids to its cognate tRNA molecule. Mitochondrial diseases are a large, clinically heterogeneous group of disorders with diverse etiologies, ages of onset, and involved organ systems. Diseases related to mt-aaRS mutations are associated with specific syndromes that affect the central nervous system and produce highly characteristic MRI patterns, prototypically the DARS2, EARS, and AARS2 leukodystrophies, which are caused by mutations in mitochondrial aspartyl-tRNA synthetase, mitochondria glutamate tRNA synthetase, and mitochondrial alanyl-tRNA synthetase, respectively.

Body

The disease patterns emerging for these leukodystrophies are distinct in terms of the age of onset, nature of disease progression, and predominance of involved white matter tracts. In DARS2 and EARS2 disorders, earlier disease onset is typically correlated with more significant brain abnormalities, rapid neurological decline, and greater disability. In AARS2 leukodystrophy cases reported thus far, there is nearly invariable progression to severe disability and atrophy of involved brain regions, often within a decade. Although most mutations are compound heterozygous inherited in an autosomal recessive fashion, homozygous variants are found in each disorder and demonstrate high phenotypic variability. Affected siblings manifest disease on a wide spectrum.

Conclusion

The syndromic nature and selective vulnerability of white matter tracts in these disorders suggests there may be a shared mechanism of mitochondrial dysfunction to target for study. There is evidence that the clinical variability and white matter tract specificity of each mt-aaRS leukodystrophy depend on both canonical and non-canonical effects of the mutations on the process of mitochondrial translation. Furthermore, different sensitivities to the mt-aaRS mutations have been observed based on cell type. Most mutations result in at least partial retention of mt-aaRS enzyme function with varied effects on the mitochondrial respiratory chain complexes. In EARS2 and AARS2 cells, this appears to result in cumulative impairment of respiration. Mt-aaRS mutations may also affect alternative biochemical pathways such as the integrated stress response, a homeostatic program in eukaryotic cells that typically confers cytoprotection, but can lead to cell death when abnormally activated in response to pathologic states. Systematic review of this group of disorders and further exploration of disease mechanisms in disease models and neural cells are warranted.
Spatiotemporal development of spinal neuronal and glial populations in the Ts65Dn mouse model of Down syndrome
Authors: Aziz Nadine M. , Klein Jenny A. , Brady Morgan R. , Olmos-Serrano Jose Luis , Gallo Vittorio , Haydar Tarik F.
Published: December 2019

Background

Down syndrome (DS), caused by the triplication of chromosome 21, results in a constellation of clinical features including changes in intellectual and motor function. Although altered neural development and function have been well described in people with DS, few studies have investigated the etiology underlying the observed motor phenotypes. Here, we examine the development, patterning, and organization of the spinal cord throughout life in the Ts65Dn mouse, a model that recapitulates many of the motor changes observed in people with DS.

Methods

Spinal cords from embryonic to adult animals were processed for gene and protein expression (immunofluorescence) to track the spatiotemporal development of excitatory and inhibitory neurons and oligodendroglia. Postnatal analyses were focused on the lumbar region due to the reflex and gait abnormalities found in Ts65Dn mice and locomotive alterations seen in people with DS.

Results

Between embryonic days E10.5 and E14.5, we found a larger motor neuron progenitor domain in Ts65Dn animals containing more OLIG2-expressing progenitor cells. These disturbed progenitors are delayed in motor neuron production but eventually generate a large number of ISL1+ migrating motor neurons. We found that higher numbers of PAX6+ and NKX2.2+ interneurons (INs) are also produced during this time frame. In the adult lumbar spinal cord, we found an increased level ofHb9and a decreased level ofIrx3gene expression in trisomic animals. This was accompanied by an increase in Calretinin+ INs, but no changes in other neuronal populations. In aged Ts65Dn animals, both Calbindin+ and ChAT+ neurons were decreased compared to euploid controls. Additionally, in the dorsal corticospinal white matter tract, there were significantly fewer CC1+ mature OLs in 30- and 60-day old trisomic animals and this normalized to euploid levels at 10–11 months. In contrast, the mature OL population was increased in the lateral funiculus, an ascending white matter tract carrying sensory information. In 30-day old animals, we also found a decrease in the number of nodes of Ranvier in both tracts. This decrease normalized both in 60-day old and aged animals.

Conclusions

We show marked changes in both spinal white matter and neuronal composition that change regionally over the life span. In the embryonic Ts65Dn spinal cord, we observe alterations in motor neuron production and migration. In the adult spinal cord, we observe changes in oligodendrocyte maturation and motor neuron loss, the latter of which has also been observed in human spinal cord tissue samples. This work uncovers multiple cellular perturbations during Ts65Dn development and aging, many of which may underlie the motor deficits found in DS.
Accuracy of genomic BLUP when considering a genomic relationship matrix based on the number of the largest eigenvalues: a simulation study
Authors: Pocrnic Ivan , Lourenco Daniela A. L. , Masuda Yutaka , Misztal Ignacy
Published: December 2019

Background

The dimensionality of genomic information is limited by the number of independent chromosome segments (Me), which is a function of the effective population size. This dimensionality can be determined approximately by singular value decomposition of the gene content matrix, by eigenvalue decomposition of the genomic relationship matrix (GRM), or by the number of core animals in the algorithm for proven and young (APY) that maximizes the accuracy of genomic prediction. In the latter, core animals act as proxies to linear combinations ofMe. Field studies indicate that a moderate accuracy of genomic selection is achieved with a small dataset, but that further improvement of the accuracy requires much more data. When only one quarter of the optimal number of core animals are used in the APY algorithm, the accuracy of genomic selection is only slightly below the optimal value. This suggests that genomic selection works on clusters ofMe.

Results

The simulation included datasets with different population sizes and amounts of phenotypic information. Computations were done by genomic best linear unbiased prediction (GBLUP) with selected eigenvalues and corresponding eigenvectors of the GRM set to zero. About four eigenvalues in the GRM explained 10% of the genomic variation, and less than 2% of the total eigenvalues explained 50% of the genomic variation. With limited phenotypic information, the accuracy of GBLUP was close to the peak where most of the smallest eigenvalues were set to zero. With a large amount of phenotypic information, accuracy increased as smaller eigenvalues were added.

Conclusions

A small amount of phenotypic data is sufficient to estimate only the effects of the largest eigenvalues and the associated eigenvectors that contain a large fraction of the genomic information, and a very large amount of data is required to estimate the remaining eigenvalues that account for a limited amount of genomic information. Core animals in the APY algorithm act as proxies of almost the same number of eigenvalues. By using an eigenvalues-based approach, it was possible to explain why the moderate accuracy of genomic selection based on small datasets only increases slowly as more data are added.
The importance of controlled mating in honeybee breeding
Authors: Plate Manuel , Bernstein Richard , Hoppe Andreas , Bienefeld Kaspar
Published: December 2019

Background

Controlled mating procedures are widely accepted as a key aspect of successful breeding in almost all animal species. In honeybees, however, controlled mating is hard to achieve. Therefore, there have been several attempts to breed honeybees using free-mated queens. In such breeding schemes, selection occurs only on the maternal path since the drone sires are random samples of the population. The success rates of breeding approaches without controlled mating have so far not been investigated on a theoretical or simulation-based level.

Methods

Stochastic simulation studies were carried out to examine the chances of success in honeybee breeding with and without controlled mating. We investigated the influence of different sizes of breeding populations (500, 1000, 2000 colonies per year) and unselected passive populations (0, 500, 1000, 2000, infinitely many colonies per year) on selection for a maternally (queen) and directly (worker group) influenced trait with moderate ($$r_{md}=-\,0.53$$rmd=-0.53) or strong ($$r_{md}=-\,0.88$$rmd=-0.88) negative correlation between the two effects. The simulations described 20 years of selection.

Results

Our simulations showed a reduction of breeding success between 47 and 99% if mating was not controlled. In the most drastic cases, practically no genetic gain could be generated without controlled mating. We observed that in the trade-off between selection for direct or maternal effects, the absence of mating control leads to a shift in favor of maternal effects. Moreover, we describe the implications of different breeding strategies on the unselected passive population that benefits only indirectly via the transfer of queens or drones from the breeding population. We show that genetic gain in the passive population develops parallel to that of the breeding population. However, we found a genetic lag that became significantly smaller as more breeding queens served as dams of queens in the passive population.

Conclusions

We conclude that even when unwanted admixture of subspecies can be excluded in natural matings, controlled mating is imperative for successful breeding efforts. This is especially highlighted by the strong positive impact that controlled mating in the breeding population has on the unselected passive population.
EvoFreq: visualization of the Evolutionary Frequencies of sequence and model data
Authors: Gatenbee Chandler D. , Schenck Ryan O. , Bravo Rafael R. , Anderson Alexander R. A.
Published: December 2019

Background

High throughput sequence data has provided in depth means of molecular characterization of populations. When recorded at numerous time steps, such data can reveal the evolutionary dynamics of the population under study by tracking the changes in genotype frequencies over time. This necessitates a simple and flexible means of visualizing an increasingly complex set of data.

Results

Here we offer EvoFreq as a comprehensive tool set to visualize the evolutionary and population frequency dynamics of clones at a single point in time or as population frequencies over time using a variety of informative methods. EvoFreq expands substantially on previous means of visualizing the clonal, temporal dynamics and offers users a range of options for displaying their sequence or model data.

Conclusions

EvoFreq, implemented in R with robust user options and few dependencies, offers a high-throughput means of quickly building, and interrogating the temporal dynamics of hereditary information across many systems. EvoFreq is freely available viahttps://github.com/MathOnco/EvoFreq.
Predicting associations among drugs, targets and diseases by tensor decomposition for drug repositioning
Authors: Wang Ran , Li Shuai , Cheng Lixin , Wong Man Hon , Leung Kwong Sak
Published: December 2019

Background

Development of new drugs is a time-consuming and costly process, and the cost is still increasing in recent years. However, the number of drugs approved by FDA every year per dollar spent on development is declining. Drug repositioning, which aims to find new use of existing drugs, attracts attention of pharmaceutical researchers due to its high efficiency. A variety of computational methods for drug repositioning have been proposed based on machine learning approaches, network-based approaches, matrix decomposition approaches, etc.

Results

We propose a novel computational method for drug repositioning. We construct and decompose three-dimensional tensors, which consist of the associations among drugs, targets and diseases, to derive latent factors reflecting the functional patterns of the three kinds of entities. The proposed method outperforms several baseline methods in recovering missing associations. Most of the top predictions are validated by literature search and computational docking. Latent factors are used to cluster the drugs, targets and diseases into functional groups. Topological Data Analysis (TDA) is applied to investigate the properties of the clusters. We find that the latent factors are able to capture the functional patterns and underlying molecular mechanisms of drugs, targets and diseases. In addition, we focus on repurposing drugs for cancer and discover not only new therapeutic use but also adverse effects of the drugs. In the in-depth study of associations among the clusters of drugs, targets and cancer subtypes, we find there exist strong associations between particular clusters.

Conclusions

The proposed method is able to recover missing associations, discover new predictions and uncover functional clusters of drugs, targets and diseases. The clustering of drugs, targets and diseases, as well as the associations among the clusters, provides a new guiding framework for drug repositioning.
Thymol tolerance in Escherichia coli induces morphological, metabolic and genetic changes
Authors: Al-Kandari Fatemah , Al-Temaimi Rabeah , van Vliet Arnoud H. M. , Woodward Martin J.
Published: December 2019

Background

Thymol is a phenolic compound used for its wide spectrum antimicrobial activity. There is a limited understanding of the antimicrobial mechanisms underlying thymol activity. To investigate this, E. coli strain JM109 was exposed to thymol at sub-lethal concentrations and after 16 rounds of exposure, isolates with a 2-fold increased minimal inhibitory concentration (MIC) were recovered (JM109-Thyr). The phenotype was stable after multiple sub-cultures without thymol.

Results

Cell morphology studies by scanning electron microscopy (SEM) suggest that thymol renders bacterial cell membranes permeable and disrupts cellular integrity. 1H Nuclear magnetic resonance (NMR) data showed an increase in lactate and the lactic acid family amino acids in the wild type and JM109-Thyr in the presence of thymol, indicating a shift from aerobic respiration to fermentation. Sequencing of JM109-Thyr defined multiple mutations including a stop mutation in the acrR gene resulting in a truncation of the repressor of the AcrAB efflux pump. AcrAB is a multiprotein complex traversing the cytoplasmic and outer membrane, and is involved in antibiotic clearance.

Conclusions

Our data suggests that thymol tolerance in E. coli induces morphological, metabolic and genetic changes to adapt to thymol antimicrobial activity.
Role of membrane compartment occupied by Can1 (MCC) and eisosome subdomains in plant pathogenicity of the necrotrophic fungus Alternaria brassicicola
Authors: Colou Justine , N’Guyen Guillaume Quang , Dubreu Ophélie , Fontaine Kévin , Kwasiborski Anthony , Bastide Franck , Manero Florence , Hamon Bruno , Aligon Sophie , Simoneau Philippe , Guillemette Thomas
Published: December 2019

Background

MCC/eisosomes are membrane microdomains that have been proposed to participate in the plasma membrane function in particular by regulating the homeostasis of lipids, promoting the recruitment of specific proteins and acting as provider of membrane reservoirs.

Results

Here we showed that several potential MCC/eisosomal protein encoding genes in the necrotrophic fungusA. brassicicolawere overexpressed when germinated spores were exposed to antimicrobial defence compounds, osmotic and hydric stresses, which are major constraints encountered by the fungus during the plant colonization process. Mutants deficient for key MCC/eisosome components did not exhibit any enhanced susceptibility to phytoalexins and to applied stress conditions compared to the reference strain, except for a slight hypersensitivity of the∆∆abpil1a-abpil1bstrain to 2 M sorbitol. Depending on the considered mutants, we showed that the leaf and silique colonization processes were impaired by comparison to the wild-type, and assumed that these defects in aggressiveness were probably caused by a reduced appressorium formation rate.

Conclusions

This is the first study on the role of MCC/eisosomes in the pathogenic process of a plant pathogenic fungus. A link between these membrane domains and the fungus ability to form functional penetration structures was shown, providing new potential directions for plant disease control strategies.
Comparison of emergence agitation between succinylcholine and rocuronium-sugammadex in adults following closed reduction of a nasal bone fracture: a prospective randomized controlled trial
Authors: Lee Seok-Jin , Sung Tae-Yun , Cho Choon-Kyu
Published: December 2019

Background

Sugammadex allows rapid recovery from rocuronium-induced neuromuscular blockade. Succinylcholine is often used for brief surgeries but is associated with myalgia, headache, histamine release, and increased lactate levels. Thus, we hypothesized that succinylcholine may affect emergence agitation (EA) and compared the effects of succinylcholine and rocuronium-sugammadex on EA in patients undergoing closed reduction of a nasal bone fracture under general anesthesia.

Methods

Forty-two patients were prospectively enrolled and allocated randomly to the succinylcholine group (group SC) or the rocuronium-sugammadex group (group RS; eachn = 21). Neuromuscular block and its reversal were achieved with succinylcholine and normal saline in group SC, whereas rocuronium and sugammadex were administered in group RS. After surgery, the incidence of EA as a primary outcome, the incidence of dangerous EA, and duration of EA as secondary outcomes were compared.

Results

The incidence of EA was higher in group SC than in group RS (90.5% vs. 47.6%, respectively; relative risk [RR] 4.3; 95% confidence interval [CI] 1.2 to 15.7;P = .006). The incidence of dangerous EA increased in group SC compared to group RS (33.3% vs. 4.8%, respectively; RR 2.1; 95% CI 1.3 to 3.4;P = .045). The duration of agitation was longer in group SC than in group RS [106.5 (65.1) vs. 40.4 (26.0) sec; mean difference 66.1 s; 95% CI 31.0 to 101.1; effect size 1.3;P = .001).

Conclusion

Succinylcholine increases the incidence, severity, and duration of EA compared to rocuronium-sugammadex in patients undergoing closed reduction of a nasal bone fracture.

Trial registration

CRiS Registration numberKCT0002673. Initial registration date was 31 January 2018 (Retrospectively registered).
Opportunities and barriers for providing HIV testing through community health centers in mainland China: a nationwide cross-sectional survey
Authors: Ong Jason J. , Peng Ming Hui , Wong William W. , Lo Ying-Ru , Kidd Michael R. , Roland Martin , Zhu Shan Zhu , Jiang Sun Fang
Published: December 2019

Background

Primary care may be an avenue to increase coverage of HIV testing but it is unclear what challenges primary healthcare professionals in low- and middle-income countries face. We describe the HIV testing practices in community health centres (CHCs) and explore the staff’s attitude towards further development of HIV testing services at the primary care level in China.

Methods

We conducted a national, cross-sectional survey using a stratified random sample of CHCs in 20 cities in 2015. Questionnaires were completed by primary care doctors and nurses in CHCs, and included questions regarding their demographics, clinical experience and their views on the facilitators and barriers to offering HIV testing in their CHC. Multivariate logistic regression was conducted to examine the association between staff who would offer HIV testing and their sociodemographic characteristics.

Results

A total of 3580 staff from 158 CHCs participated. Despite the majority (81%) agreeing that HIV testing was an important part of healthcare, only 25% would provide HIV testing when requested by a patient. The majority (71%) were concerned about reimbursement, and half (47%) cited lack of training as a major barrier. Almost half (44%) believed that treating people belonging to high-risk populations would scare other patients away, and 6% openly expressed their dislike of people belonging to high-risk populations. Staff who would offer HIV testing were younger (adjusted odds ratio (aOR) 0.97 per year increase in age, 95% confidence interval (CI):0.97–0.98); trained as a doctor compared to a nurse (aOR 1.79, 95%CI:1.46–2.15); held a bachelor degree or above (aOR 1.34, 95%CI:1.11–1.62); and had previous HIV training (aOR 1.55, 95%CI:1.27–1.89).

Conclusions

Improving HIV training of CHC staff, including addressing stigmatizing attitudes, and improving financial reimbursement may help increase HIV testing coverage in China.
Correction to: Homozygous missense variant in the TTN gene causing autosomal recessive limb-girdle muscular dystrophy type 10
Authors: Khan Amjad , Wang Rongrong , Han Shirui , Umair Muhammad , Abbas Safdar , Khan Muhammad Ismail , Alshabeeb Mohammad A. , Alfadheland Majid , Zhang Xue
Published: December 2019

Please be advised that following publication of the original article [1], the authors have identified the following errors with the scientific content.
An investigation of oxidant/antioxidant balance in patients with migraine: a case-control study
Authors: Togha Mansoureh , Razeghi Jahromi Soodeh , Ghorbani Zeinab , Ghaemi Amir , Rafiee Pegah
Published: December 2019

Background

In recent years, the role of neuroinflammation and oxidative stress in migraine pathogenesis has achieved considerable interest; however, to date findings are equivocal. Thus, the objective of this study was to investigate biomarkers of oxidative stress in episodic and chronic migraineurs (EM and CM patients) and controls.

Methods

Forty-four patients with EM, 27 individuals with CM and 19 age-sex-matched controls were enrolled. After collecting data on demographic and headache characteristics, blood samples were collected and analyzed to detect serum levels of oxidative stress biomarkers (malondialdehyde (MDA) and nitric oxide (NO)); total antioxidant capacity using Trolox equivalent antioxidant capacity (TEAC) assay; and antioxidant enzymes (catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase-1 (GPx-1)).

Results

Serum levels of CAT and SOD were significantly lower in the CM group than the EM group and controls. However, serum GPx-1 levels of the CM patients were slightly higher than the EM patients and controls (P-value≤0.001). CM patients had lower mean TEAC values than EM patients and controls. In addition, serum levels of NO and MDA were significantly elevated among subjects with CM compared to EM and control individuals (P-value≤0.001). Pearson correlation analysis revealed negative correlations between the number of days of having headaches per month and serum concentrations of the two antioxidant enzymes CAT (r = − 0.60, P-value< 0.001) and SOD (r = − 0.50, P-value< 0.001) as well as TEAC values (r = − 0.61, P-value< 0.001); however, there were positive correlations between headache days and serum GPx-1 levels (r = 0.46, P-value< 0.001), NO (r = 0.62, P-value< 0.001), and MDA (r = 0.64, P-value< 0.001).

Conclusion

Present findings highlighted that chronic migraineurs had lower total non-enzymatic antioxidant capacity and higher oxidative stress than episodic migraineurs and control individuals. Although more studies are needed to confirm these data, applying novel prophylactic medications or dietary supplements with antioxidant properties could be promising in migraine therapy.