bluuebunny/crossref_metadata_2025 huggingface dataset:
New Horizons Observations of the Atmosphere of Pluto
Authors: Gladstone G. Randall , Young Leslie A.
Published: May 2019

New Horizons data provide a snapshot of the current state of Pluto's atmosphere. Winds are slow and mostly controlled by sublimation of surface ices. Molecular nitrogen is the primary constituent below 1,800 km, while methane and carbon monoxide are important minor species. Photolysis of these gases leads to a thin haze that encompasses Pluto from the surface up to >500-km altitude and is important in heating and cooling the atmosphere. A cold (∼70 K) upper atmosphere curtails the escape of Pluto's molecular nitrogen to space, although there is substantial escape of methane (∼5 × 1025molecules s−1), coincidentally about equal to its loss by photochemistry. It is unknown if the current atmosphere is representative of its long-term average state. From the inferred rapid rate of haze settling, it seems that Pluto's atmosphere must occasionally undergo collapse to allow time for radiation processing of the colorless haze material into the dark deposits found on the surface. ▪ This article outlines what has been gleaned about Pluto's atmosphere in the years since the New Horizons flyby. ▪ Pluto's atmosphere is most similar to Titan's—with the photochemistry of supervolatile nitrogen and hydrocarbons resulting in a kind of factory for cold haze production. ▪ Much has been learned about Pluto's atmosphere, but many new questions have arisen, and these will likely remain unanswered until there is a follow-up mission—no doubt a long time from now.
The Compositional Diversity of Low-Mass Exoplanets
Authors: Jontof-Hutter Daniel
Published: May 2019

Low-mass planets have an extraordinarily diverse range of bulk compositions, from primarily rocky worlds to those with deep gaseous atmospheres. As techniques for measuring the masses of exoplanets advance the field toward the regime of rocky planets, from ultrashort orbital periods to Venus-like distances, we identify the bounds on planet compositions, where sizes and incident fluxes inform bulk planet properties. In some cases, the precision of measurement of planet masses and sizes is approaching the theoretical uncertainties in planet models. An emerging picture explains aspects of the diversity of low-mass planets, although some problems remain: Do extreme low-density, low-mass planets challenge models of atmospheric mass loss? Are planet sizes strictly separated by bulk composition? Why do some stellar characterizations differ between observational techniques? With the Transiting Exoplanet Survey Satellite ( TESS) mission, low-mass exoplanets around the nearest stars will soon be discovered and characterized with unprecedented precision, permitting more detailed planetary modeling and atmospheric characterization of low-mass exoplanets than ever before. ▪ Following the Kepler mission, studies of exoplanetary compositions have entered the terrestrial regime. ▪ Low-mass planets have an extraordinary range of compositions, from Earth-like mixtures of rock and metal to mostly tenuous gas. ▪ The TESS mission will discover low-mass planets that can be studied in more detail than ever before.
Seawater Chemistry Through Phanerozoic Time
Authors: Turchyn Alexandra V. , DePaolo Donald J.
Published: May 2019

The major ion balance of the ocean, particularly the concentrations of magnesium (Mg), calcium (Ca), and sulfate (SO4), has evolved over the Phanerozoic (last 550 million years) in concert with changes in sea level and the partial pressure of carbon dioxide ( pCO2). We review these changes, along with changes in Mg/Ca and strontium/calcium (Sr/Ca) of the ocean; how the changes were reconstructed; and the implication of the suggested changes for the overall charge balance of the ocean. We conclude that marine Mg, Ca, and SO4concentrations are responding to different aspects of coupled tectonic changes over the Phanerozoic and the resulting effect on sea level. We suggest a broad conceptual model for the Phanerozoic changes in Mg, Ca, and SO4concentrations along with the seawater87Sr/86Sr and sulfur isotope composition. ▪ Marine concentrations of magnesium, sulfate, and calcium have varied over the last 550 million years in sync with changes in sea level and atmospheric carbon dioxide. ▪ Seawater chemistry and sea level both respond to supercontinent formation and breakup, age of the ocean floor, and extent of continental shelf area. ▪ Changes in plate tectonics impact the ocean's chemical balance and the carbon cycle in varied ways, resulting in cyclical changes in key climatic variables over geological time.
Different contributions from lungs and chest wall to respiratory mechanics in mice, rats, and rabbits
Authors: Südy Roberta , Fodor Gergely H. , Dos Santos Rocha André , Schranc Álmos , Tolnai József , Habre Walid , Peták Ferenc
Published: May 2019

Changes in lung mechanics are frequently inferred from intact-chest measures of total respiratory system mechanics without consideration of the chest wall contribution. The participation of lungs and chest wall in respiratory mechanics has not been evaluated systematically in small animals commonly used in respiratory research. Thus, we compared these contributions in intact-chest mice, rats, and rabbits and further characterized the influence of positive end-expiratory pressure (PEEP). Forced oscillation technique was applied to anesthetized mechanically ventilated healthy animals to obtain total respiratory system impedance (Zrs) at 0, 3, and 6 cmH2O PEEP levels. Esophageal pressure was measured by a catheter-tip micromanometer to separate Zrs into pulmonary (ZL) and chest wall (Zcw) components. A model containing a frequency-independent Newtonian resistance (RN), inertance, and a constant-phase tissue damping (G) and elastance (H) was fitted to Zrs, ZL, and Zcw spectra. The contribution of Zcw to RN was negligible in all species and PEEP levels studied. However, the participation of Zcw in G and H was significant in all species and increased significantly with increasing PEEP and animal size (rabbit > rat > mice). Even in mice, the chest wall contribution to G and H was still considerable, reaching 47.0 ± 4.0(SE)% and 32.9 ± 5.9% for G and H, respectively. These findings demonstrate that airway parameters can be assessed from respiratory system mechanical measurements. However, the contribution from the chest wall should be considered when intact-chest measurements are used to estimate lung parenchymal mechanics in small laboratory models (even in mice), particularly at elevated PEEP levels.

NEW & NOTEWORTHY In species commonly used in respiratory research (rabbits, rats, mice), esophageal pressure-based estimates revealed negligible contribution from the chest wall to the Newtonian resistance. Conversely, chest wall participation in the viscoelastic tissue mechanical parameters increased with body size (rabbit > rat > mice) and positive end-expiratory pressure, with contribution varying between 30 and 50%, even in mice. These findings demonstrate the potential biasing effects of the chest wall when lung tissue mechanics are inferred from intact-chest measurements in small laboratory animals.
Blockade Effects of Anti-Interferon- (IFN-) γ Autoantibodies on IFN-γ-Regulated Antimicrobial Immunity
Authors: Krisnawati Dyah Ika , Liu Yung-Ching , Lee Yuarn-Jang , Wang Yun-Ting , Chen Chia-Ling , Tseng Po-Chun , Shen Ting-Jing , Lin Chiou-Feng
Published: May 2019

The interferon- (IFN-) γ expression is elicited in response to microbial infections and activates immune surveillance by antimicrobial immune elements to induce microbial killing. Patients with adult-onset immunodeficiency who suffer from recurrent infections with microbes, particularly nontuberculous mycobacteria (NTM), commonly display genetic defects in IFN-γ signaling as well as the generation of anti-IFN-γ autoantibodies (autoAbs). Because IFN-γ is an activator of macrophage differentiation and a proinflammatory activator of innate immunity, the blockade effects of the autoAbs present in NTM patient serum on IFN-γ are hypothesized to regulate the antimicrobial function of macrophages. In the presence of patient serum, IFN-γ-induced type 1 macrophage (M1) differentiation was inhibited in PMA-stimulated human monocytic THP-1 cells. Treatment with patient serum significantly blocked the production of proinflammatory factors, including cytokines/chemokines and reactive oxygen/nitrogen species, by M1 macrophages. Importantly, IFN-γ-facilitated phagocytosis and degradation of heat-killed mycobacterium were decreased by cotreatment with patient serum. These results show the blockade activity of anti-IFN-γ autoAbs on IFN-γ-mediated antimicrobial immunity in macrophages.
Free-Electron Screening Mechanism of the Shallow Impurity Breakdown in n-GaAs: Evidences from the Photoelectric Zeeman and Cyclotron Resonance Spectroscopies
Authors: Alekperov O. Z. , Nakhmedov E. P.
Published: May 2019

A novel breakdown (BD) mechanism of shallow impurity (SI) under the electric field at low temperatures is suggested for n‐GaAs samples with the donor concentrations 1014 cm−3≤ND≤1016 cm−3 and the compensation degree 0.3≤K=NA/ND≤0.8 with acceptors of concentration NA in the external magnetic fields up to H=6.5T, oriented parallel or perpendicular to the external electric field. Diagnosis of the BD mechanism was performed by SI Zeeman (mainly from the ground state 1s to 2p+1 and other excitation states) and cyclotron resonance photoelectric spectroscopy (PES) methods in the wide interval of the electric field including the BD region too. The obtained results reveal that the BD electric field εBD does not correlate with K and the carrier’s mobility μ of the samples, which contradict to the well-known impact ionization mechanism (IIM). A serious discrepancy with IIM is that εBD does not almost depend on the magnetic field up to H=6.5T when εH though the SI ionization energy increases two times. The cyclotron resonance (CR) measurements show that the line width does not depend on the electric field for ε<εBD, indicating the lack of free-carrier (FC) heating in contradiction with IIM. A considerable decrease of the free carriers’ capture cross section (CCS) area by ionized SI centers with a subsequent increase in the FC concentration n is observed by means of PES investigation of the 1s⟶2p+1 and CR lines in the electric fields ε≤εBD and at different magnetic fields, applied along (Hε) the electric field or perpendicular (H⊥ε) to the electric field. The slope of the 1s⟶2p+1 line intensity on the electric field for εH does not depend on the magnetic field, which is valid for εBD too. Various effects determined in the PES measurements at ε=εBD, such as a drastic narrowing of the 1s⟶2p+1 and CR lines, a shift of the CR line to higher magnetic fields, and disappearing of the lines to higher excited SI states, were clarified to be a result of screening of the SI Coulomb potential by free carriers. The FC screening at the BD reduces the potential fluctuation and its influence to the PES line shape of 1s⟶2p+1 and other excited states. It is shown that an increase in the FC concentration reduces the CCS, which can be assumed as the main factor along with the increase in the ionization coefficient for the SI breakdown in the electric field. The screening length rs of the SI Coulomb potential decreases with the increasing FC concentration, reducing the CCS; the latter seems to vanish completely at rs=aB∗ (aB∗ is the effective Bohr radius), when high screening results in vanishing of all the bound states of the Coulomb potential. Note that this limit is similar to the Mott transition. Many experimental facts and our calculation of the CCS support the suggested mechanism for the SI breakdown. The well-known IIM is valid for samples with SI concentrations N≪1013 cm−3 and takes place at very high electric fields.
Experimental and Numerical Analysis of the Bolt Connections in a Low‐Rise Precast Wall Panel Structure System
Authors: Guo Wei , Zhai Zhipeng , Yu Zhiwu , Chen Feng , Gong Yongzhi , Tan Tao
Published: May 2019

This paper develops a novel dry connection utilizing high‐strength bolts and introduces the corresponding low‐rise precast wall panel structure system. To investigate the seismic performance of the structure system with full bolt connections, monotonic loading tests of the connection joint and cyclic lateral loading tests of three full‐scaled precast shear walls are both conducted. Based on the test data, axial and shear mechanical models of the connection are given. Meanwhile, experimental results show that the failure mode of the connection is dominated by anchored rebar ductile rupture, and the precast structure system presents a stable energy dissipation capacity and a good seismic ductility. The numerical model of the precast shear wall is then developed and validated by the cyclic loading test. Also a simplified calculation method to predict the lateral strength of the precast shear wall is proposed. According to the calculation results, the distance between the center of the connection and the edge of the shear wall is suggested to be 150 mm, while the wall thickness is recommended to be 120 mm or 150 mm. Finally, a three‐story precast wall panel structure is employed to assess the collapse performance of the proposed precast structure system by using the presented numerical model. The results indicate that the proposed structure system with full bolt connections has high stiffness and high seismic resistance against collapse.
Effects of Different Nanoscale Microelement-Containing Formulations for Presowing Seed Treatment on Growth of Soybean Seedlings
Authors: Chau Nguyen Hoai , Doan Quang Ha , Chu Thi Hao , Nguyen Thi Thuy , Dao Trong Hien , Ngo Quoc Buu
Published: May 2019

Effects of nanoscale microelement-containing formulations for presowing seed treatment on germination and growth of soybean were studied. The formulations were prepared based on some well-known commercial products such as Doktor Tarsa Company and Wuxal Company. The results showed that all the tested formulations demonstrated noticeably higher stimulation effects on germination and soybean seedlings growth, among which the nanosized Co- and MoO3-containing formulations exhibited the highest growth indices compared with the control (overpassed by about 10%), asserting the role of Co and Mo together with biostimulants as an effective nutrient mixture for growth and development of soybean plants. Enzymatic analysis of the nanotreated soybean shoots also demonstrated a similar feature; the studied formulations exhibited higher amylase and lipase activities compared with those of the control.
The Combination of Mulberry Extracts and Silk Amino Acids Alleviated High Fat Diet-Induced Nonalcoholic Hepatic Steatosis by Improving Hepatic Insulin Signaling and Normalizing Gut Microbiome Dysbiosis in Rats
Authors: Park Sunmin , Zhang Ting , Qiu Jing Yi , Wu Xuangao
Published: May 2019

Mulberry water extracts (MB) and silk amino acids (SA) are reported to improve oxidative stress and inflammation, respectively. We hypothesized whether the mixture of mulberry water extracts and silk amino acids can alleviate nonalcoholic fatty liver disease (NAFLD) induced by high fat diets. Male Sprague Dawley rats were orally provided with high fat diets containing different ratios of MB and SA (1:3, MS1:3, or 1:5, MS1:5) or cellulose (the disease-control) for 12 weeks. Rats had 200 or 600 mg/kg bw of MS1:3 and MS1:5 (MS1:3-L, MS1:3-H; MS1:5-L, and MS1:5-H). Rats in the normal-control group were fed the 20% fat diet with cellulose. Disease-control rats exhibited much greater triglyceride (TG) deposition in the liver than the normal-control rats along with increased body weight gain, visceral fat mass, serum concentrations of cholesterol, triglyceride and nonesterified fatty acid (NEFA), and insulin resistance. Disease-control rats also had liver damage with increased oxidative stress and inflammation compared to the normal-control rats. MS1:3-H and MS1:5-H were found to have greater hepatic glycogen accumulation and decreased hepatic TG, insulin resistance, and dyslipidemia, with MS1:5-H being similar to the normal-control. MS1:3-H alleviated oxidative stress with lower hepatic lipid peroxide compared to MS1:5-H whereas MS1:5-H ameliorated inflammation and hepatocyte damage better than MS1:3-H. Both MS1:3-H and MS1:5-H potentiated hepatic insulin signaling (pAkt⟶pACC) and reduced the mRNA expression of TG synthesis genes mRNA (FAS and SREBP-1c). In the gut microbiome MS1:3-H elevated the ratio of Bacteroidales to Clostridiales in the cecum better than MS1:5-H but MS1:5-H reduced the proinflammatory Turicibacterales. In conclusion, both MS1:3-H and MS1:5-H prevented liver damage induced by high fat diets, mainly by suppressing oxidative stress and inflammation, respectively. MS1:3 and MS1:5 might be used as therapeutic agent for NAFLD.
Biomarkers in Inflammatory Bowel Disease-Associated Spondyloarthritis: State of the Art and Unmet Needs
Authors: Benfaremo Devis , Luchetti Michele Maria , Gabrielli Armando
Published: May 2019

Inflammatory bowel disease-associated spondyloarthritis is a systemic disease characterized by the chronic inflammation of both the gastrointestinal tract and the musculoskeletal system. Since inflammatory bowel disease-associated spondyloarthritis has been associated with a significant diagnostic delay, which may lead to poor quality of life and progression of joint damage, efforts to discover new reliable and noninvasive diagnostic biomarkers have been made. We reviewed the state of the art of biomarker research in inflammatory bowel disease-associated spondyloarthritis, showing that to date it has been largely unsatisfactory. Only a few of the biomarkers that have been investigated are likely to enter the clinical practice upon further validation in independent cohorts. The research of new and innovative biomarkers for inflammatory bowel disease-associated spondyloarthritis is warranted.
A Case of Babesiosis in a Pregnant Patient Treated with Red Blood Cell Exchange Transfusion
Authors: Abittan Baruch , Nizam Aaron , Oey Michael , Callan Felicia , Simmonds Lisa , Pachtman Sarah L.
Published: May 2019

Babesiosis, caused predominantly by Babesia microti, is an emerging health risk in the Northeastern and Midwestern United States. We present a case of a pregnant woman with history of splenectomy diagnosed with babesiosis at 23 5/7 weeks of gestational age refractory to antimicrobial therapy. She underwent the first reported red blood cell exchange transfusion for babesiosis in pregnancy, at 24 4/7 weeks of gestational age, which resulted in resolution of parasitemia. She had a full term, uncomplicated cesarean delivery. Exchange transfusion is potentially a safe treatment option for severe babesiosis infection in pregnancy and should be considered when other methods are poorly tolerated or ineffective.
Violão e identidade nacional: a “moral” do instrumento
Authors: Llanos Carlos Fernando Elias
Published: May 2019

O texto analisa parte da literatura sobre a história do violão no Brasil nas primeiras décadas do século XX, no contexto das complexas relações sociais e políticas da Primeira República na cidade de Rio de Janeiro. A ideia central é discutir a noção de violão-arte, que teria surgido a partir da tradição do violão erudito europeu (como construção de discurso), em contraposição a outras práticas violonisticas que a historiografia do instrumento não menciona ou o faz ressaltando sua progressiva aceitação “moral” e distanciamento do estigma da boêmia e a vadiagem. O texto conclui problematizando como o violão configurou-se como meio de execução e corporificação de representações sociais, que chamamos de instrumento-documento, violentamente empobrecido (pois, na passagem do século XIX ao XX ele era sinônimo de marginalidade), precariamente empregado, com escassa ou nula instrução formal (não havia onde aprender a tocar) e principalmente autodidata (aprendido na prática e na tradição oral).
A new flower fly species of Cepa Thompson & Vockeroth (Diptera: Syrphidae) from the Valdivian evergreen forest hotspot, Chile
Authors: BARAHONA-SEGOVIA RODRIGO M. , BARCELÓ MATÍAS
Published: May 2019

The Neotropical region has a high species richness of flower flies. However, there are many known species awaiting proper description. Cepa Thompson & Vockeroth is a Neotropical genus with scattered records and few individuals collected of its three species. In the present study, a female of a new species of Cepa is described, C. simonettii Barahona-Segovia sp. nov., from the Valdivian evergreen forest representing the first record of this genus in Chile. In addition, an identification key to all known species of Cepa is provided. Morphological and biogeographic aspects of this new Cepa species are discussed, as well as the potential phylogenetic relationship with other members of Merodontini.
On the Creation and Evolution of Small-Scale Low-Level Vorticity Anomalies during Tropical Cyclogenesis
Authors: Smith Warren P. , Nicholls Melville E.
Published: May 2019

Recent numerical modeling and observational studies indicate the importance of vortical hot towers (VHTs) in the transformation of a tropical disturbance to a tropical depression. It has recently been recognized that convective-scale downdraft outflows that form within VHTs also preferentially develop positive vertical vorticity around their edges, which is considerably larger in magnitude than ambient values. During a numerical simulation of tropical cyclogenesis it is found that particularly strong low-level convectively induced vorticity anomalies (LCVAs) occasionally form as convection acts on the enhanced vorticity at the edges of cold pools. These features cycle about the larger-scale circulation and are associated with a coincident pressure depression and low-level wind intensification. The LCVAs studied are considerably deeper than the vorticity produced at the edges of VHT cold pool outflows, and their evolution is associated with persistent convection and vortex merger events that act to sustain them. Herein, we highlight the formation and evolution of two representative LCVAs and discuss the environmental parameters that eventually become favorable for one LCVA to reach the center of a larger-scale circulation as tropical cyclogenesis occurs.
Interpretable Deep Learning for Spatial Analysis of Severe Hailstorms
Authors: Gagne II David John , Haupt Sue Ellen , Nychka Douglas W. , Thompson Gregory
Published: May 2019

Deep learning models, such as convolutional neural networks, utilize multiple specialized layers to encode spatial patterns at different scales. In this study, deep learning models are compared with standard machine learning approaches on the task of predicting the probability of severe hail based on upper-air dynamic and thermodynamic fields from a convection-allowing numerical weather prediction model. The data for this study come from patches surrounding storms identified in NCAR convection-allowing ensemble runs from 3 May to 3 June 2016. The machine learning models are trained to predict whether the simulated surface hail size from the Thompson hail size diagnostic exceeds 25 mm over the hour following storm detection. A convolutional neural network is compared with logistic regressions using input variables derived from either the spatial means of each field or principal component analysis. The convolutional neural network statistically significantly outperforms all other methods in terms of Brier skill score and area under the receiver operator characteristic curve. Interpretation of the convolutional neural network through feature importance and feature optimization reveals that the network synthesized information about the environment and storm morphology that is consistent with our understanding of hail growth, including large lapse rates and a wind shear profile that favors wide updrafts. Different neurons in the network also record different storm modes, and the magnitude of the output of those neurons is used to analyze the spatiotemporal distributions of different storm modes in the NCAR ensemble.
Borders moving across people: Narratives of belonging among Crimean youth after 2014
Authors: Zeveleva Olga , Bludova Anastasia
Published: May 2019

This article explores how senses of belonging, place, and mobility are linked to each other in the context of rapid socio-political change and human mobility. Using the sociological concept of place-belongingness, the article examines narratives of belonging among young people from Crimea who moved to Moscow to pursue higher education in the two years following Russia’s 2014 annexation of the peninsula. Drawing on 38 biographical interviews conducted in Moscow with young people from Crimea, the article demonstrates how ‘movements of borders across people’ (to build on Rogers Brubaker’s expression) result in a non-binary construction of belonging across places, based on the access an individual has to constellations of resources different places offer. The analysis shows that narratives of belonging among young people from Crimea revolve around resource categories that include economic resources, emotional resources, resources that reconcile multiple identities, and ontological security resources. This study moves beyond analysis of identities as linked to nation-building in the post-Soviet space, focusing on categories of ‘place’ emerging from the perspectives of study participants.
Fear, Boldness, and Familiarity: The Therapeutic Landscapes of Undocumented Latina Immigrants in Atlanta, Georgia
Authors: Lane Rebecca
Published: May 2019

Drawing from 56 semi-structured interviews, this article details how undocumented Latina immigrants living in Atlanta, Georgia, in 2013 cultivated health and well-being in an insecure environment. In addition to the myriad challenges that immigrants face in accessing health care in their new communities, undocumented immigrants living in Atlanta at that time faced the legal barrier presented by Georgia’s new “show me your papers” law, which imbued public space with the risk of deportation for those who are undocumented. This law complicated health care access by making the trip to the doctor’s office risky. Immigrants’ health care decisions were thus shaped by the “geography of fear” that permeated their new communities. This fear presented itself not only in public space but also in clinics and hospitals, where many immigrants feared – and sometimes received – bad treatment. Despite the obstacles fear and immigrant policing presented, many of the women I interviewed showed boldness in their health care decisions, staking their claim to medical attention where they saw fit. Additionally, many maintained transnational networks and continued with familiar health practices from home. Combined, these strategies worked to create complex and shifting “therapeutic landscapes” in an environment permeated by insecurity and fear.
Caribbean-Atlantic Discourses of Race, Equality, and Humanity in the Age of Revolution
Authors: Reid-Vazquez Michele
Published: May 2019

As geopolitical warfare intensified in the late 18th and early 19th centuries, free individuals of African heritage increasingly disputed European ideologies that condemned them as naturally inferior and lacking in humanity. With the onset of the Haitian Revolution (1791-1804) and the Latin American wars for independence (1810-1825), individuals and groups of African descent circulated their own views. I argue that free Blacks from colonial Saint Domingue, Jamaica, and Cuba employed similar rhetorical strategies across the French, British, and Spanish empires. Their speeches, petitions, and declarations forged distinct Afro-Atlantic counter-discourses that proclaimed their equality and advocated for their human and civil rights.
Fabrication and characterization of aluminum hybrid composites reinforced with silicon nitride/graphene nanoplatelet binary particles
Authors: Şenel Mahmut Can , Gürbüz Mevlüt , Koç Erdem
Published: May 2019

In this study, pure aluminum was reinforced with pure silicon nitride (varying from 1 to 12 wt%), pure graphene nanoplatelets (changing from 0.1 to 0.5 wt%), and their hybrid form (silicon nitride/graphene nanoplatelets) by using powder metallurgy method. The results show that Vickers hardness increased to 57.5 ± 3 HV (Al-9Si3N4) and 57 ± 2.5 HV (Al-0.1GNPs) from 28 ± 2 HV (pure aluminum). Similarly, ultimate compressive strength of the pure silicon nitride and pure graphene nanoplatelet-reinforced aluminum composite was improved to 268 ± 6 MPa (Al-9Si3N4) and 138 ± 4 MPa (Al-0.5GNPs) from 106 ± 4 MPa (pure aluminum), respectively. Interestingly, the highest Vickers hardness, ultimate compressive strength, and ultimate tensile strength of aluminum-silicon nitride-graphene nanoplatelet hybrid composites were determined as 82 ± 3 HV (Al-9Si3N4-0.5GNPs), 334 ± 9 MPa (Al-9Si3N4-0.1GNPs), and 132 MPa (Al-9Si3N4-0.1GNPs), respectively. The Vickers hardness (for Al-9Si3N4-0.5GNPs), ultimate compressive strength (for Al-9Si3N4-0.1GNPs), and ultimate tensile strength (for Al-9Si3N4-0.1GNPs) improved ∼193%, ∼215%, and ∼47% when compared to pure Al, respectively. Above 9 wt% silicon nitride and 0.1 wt% graphene nanoplatelets content, an adverse effect was observed due to the agglomeration of silicon nitride and graphene nanoplatelets in aluminum matrix composites. Also, energy-dispersive X-ray and scanning electron microphotographs confirmed the presence of both silicon nitride and graphene nanoplatelets and uniformly distributed in the aluminum matrix.
Harmful Effects of Mental Imagery and Customer Orientation During New Product Screening
Authors: DeRosia Eric D. , Elder Ryan S.
Published: May 2019

One of the traditional tenets of marketing is that managers considering whether to develop and launch a new product should adopt a customer orientation and consider whether the product would satisfy the needs of customers. This research discovers that adopting a customer orientation causes managers to experience undesirable cognitive effects. The authors find that when considering customers’ needs during the screening phase of the new product development process, managers often voluntarily engage in mental imagery (i.e., cognitive simulation) that biases their evaluation of a new product idea toward unrealistic optimism—even for a flawed product that would not satisfy customer needs. Furthermore, the authors find that managers who exert greater vigilance to achieve more accurate evaluations of the new product idea are especially vulnerable to the biasing effect, leading to less accurate evaluations. The authors test an analytical technique (i.e., a theory-based approach to analyzing the new product) that successfully allows a manager to adopt a customer orientation without an attendant bias toward optimism.
Strategic Manipulation of University Rankings, the Prestige Effect, and Student University Choice
Authors: Dearden James A. , Grewal Rajdeep , Lilien Gary L.
Published: May 2019

A multiperiod, theoretical model characterizes the relationship between a publication that ranks universities and prospective students who might use this ranking to decide which university to attend. The published ranking offers information about the universities’ objective quality but also affects their prestige, which may increase student utility. This prestige effect gives the commercial publication incentive to act contrary to the best interest of the students. If a ranking created with the commonly used attribute-and-aggregate methodology creates prestige, then to maximize profit the publication needs to (1) choose attribute score weights that do not match student preferences and (2) alter those attribute score weights over time, even in the absence of changes to student preferences and/or education technology. Without a prestige effect, the publication should choose attribute score weights that match student preferences. This model also defines a student-optimal ranking methodology that maximizes the sum of the students’ utilities. The results offer insights for prospective students who use existing rankings to choose a university, as well as which ranking designs would better align with students’ preferences.
Hope and Physical Exercise: The Contributions of Hope, Self-Efficacy, and Optimism in Accounting for Variance in Exercise Frequency
Authors: Anderson Craig L. , Feldman David B.
Published: May 2019

We examine the relationship of hope with exercise using Snyder’s hope model, which defines hope as a combination of goal-directed planning (pathways) and motivation (agency). We surveyed 102 participants online via Amazon MTurk. The Adult Hope Scale and Goal-Specific Hope Scale assessed general hope and hope regarding exercise. The Leisure-Time Exercise Questionnaire assessed frequency of exercise and of any activity “long enough to work up a sweat.” We also measured optimism, exercise self-efficacy, depression, anxiety, and stress. Because hope emphasizes planning and motivation (both likely needed in fitness regimens), we expected it to relate to exercise frequency after controlling for these other variables. Indeed, exercise goal-specific hope was correlated with frequency of exercise and activity long enough to sweat, though general hope was not. This relationship held after controlling for all other variables. Future research may be useful in investigating causality, including whether hope-based interventions result in increased exercise engagement.
Acquired Factor VII deficiency – a rare but important consideration
Authors: Zaidi Mehmood Hussain , Stanley Arran , Khan Mohammed
Published: May 2019

Introduction

Isolated acquired Factor VII deficiency is a rare coagulation disorder which is independent of vitamin K deficiency. The exact pathophysiological basis of this condition is unclear. We present a series of cases highlighting different clinical scenarios where this condition was encountered.

Case series

The first case presented with intra-abdominal sepsis. The second was a patient admitted with acute kidney injury and subsequently diagnosed with myeloma. The final case presented with microangiopathic haemolytic anaemia and was suspected of having atypical Haemolytic Uraemic Syndrome. In each case, there was no family or personal history of a bleeding disorder. Follow-up Factor VII levels after recovery from illness was normal in all three cases.

Conclusion

Acquired Factor VII deficiency is an uncommon but important finding which should be considered in the general medical setting when an isolated prolonged prothrombin time is detected.
The most perfect natural laboratory in the world: Making and knowing Hawaii National Park
Authors: Shih Ashanti
Published: May 2019

This article reimagines the meanings of U.S. national parks and so-called ‘natural’ places in our environmental histories and histories of science. Environmental historians have created a compelling narrative about the creation and use of U.S. national parks as places for recreation and natural resource conservation. Although these motivations were undoubtedly significant, I argue that some of the early parks were created and used for a third, often overlooked, reason: to preserve a permanent, state-sanctioned space for scientific knowledge production. Deconstructing the concept of the “natural laboratory,” I show how scientists helped justify and then benefited from the creation of national parks.

Hawaii National Park serves as my case study. Advocates of the national park aimed to give settler colonial scientists in the Hawaiian archipelago a permanent place for their research, while tying Hawai‘i’s exotic landscape into the sublime nature of the American West. The park was framed as a perfect laboratory for U.S. experts to study “curious” flora, fauna, and geological processes, becoming a major site of knowledge production in volcanology.

Reimagining the parks in this way has ramifications for how we think about issues of access and justice. Environmental historians who have explored the ‘dark side’ of the conservation movement have yet to consider the other half of the story: the parks not only barred certain peoples and their ways of life, but also provided access to scientists – a set of actors whose work was deemed more complementary to conservationist goals than the activities of the Native Hawaiians – and marginalized local and indigenous epistemologies. Thus, the question so often asked in environmental history, “Who is nature for?” might be supplemented by the question, “Who has the power to know nature?”
The New Solitary Confinement? A Conceptual Framework for Guiding and Assessing Research and Policy on “Restrictive Housing”
Authors: Mears Daniel P. , Hughes Vivian , Pesta George B. , Bales William D. , Brown Jennifer M. , Cochran Joshua C. , Wooldredge John
Published: May 2019

As part of the rise of “get tough” punishment in recent decades, prison systems increasingly have relied on solitary confinement and what many contemporary accounts have termed “restrictive housing.” The latter includes an emphasis on some form of isolation and restrictions on privileges. Use of solitary-like confinement has engendered considerable debate because of differing views about whether it is moral or effective and whether it harms inmates. Despite this debate and the ubiquity of solitary-like confinement, there is much that remains unknown about its uses or effects. A central reason stems from inconsistent operationalizations of such housing in research and policy. This situation creates problems in generalizing the results of studies to diverse settings and populations. The goals of this article are to highlight these points and to advance scholarship and policy debates by presenting a conceptual framework for guiding and assessing research on restrictive housing.
Perceived Student Benefits of an Undergraduate Physiological Psychology Laboratory Course
Authors: Lloyd Steven A. , Shanks Ryan A. , Lopatto David
Published: May 2019

Undergraduate research (UR) is a high-impact practice associated with many positive student outcomes. However, extending UR opportunities to all students is not practical for all psychology programs. Classroom-based UR experiences (CUREs) provide a scalable solution to this problem, but there is a paucity of empirically validated, authentic CUREs across all programs and all areas of the undergraduate psychology curriculum. A quasi-experimental design involving a semester-long CURE in an upper-level physiological psychology laboratory course was conducted. Students participating in the lecture and the CURE reported significant perceived benefits across many key domains, more positive attitudes toward science, and favorable changes in postgraduation plans, especially toward graduate school and careers in science, when compared to students in the lecture-only group. The results support the call for UR in the psychology curriculum, demonstrate the effectiveness of an authentic CURE to meet this goal for all students, and provide a model for CURE dissemination in a physiological psychology laboratory course.
Correlation Between Sensorineural Hearing Loss and Chronic Otorrhea
Authors: Dobrianskyj Fernanda Martinho , Dias Gonçalves Ísis Rocha , Tamaoki Yumi , Mitre Edson Ibrahim , Quintanilha Ribeiro Fernando A.
Published: May 2019

Many studies have been trying to correlate chronic otorrhea, both in children and in adults, with the sensorineural hearing loss in the affected ear, but have been obtaining contradictory results. This loss might be due to the likely toxicity of the bacteria involved, effects of inflammatory cytokines, or constant use of ototoxic antibiotics. All the studies evaluated up to the present date compared the affected ear with the normal contralateral ear. From the digitized archive of otological surgery files of the Department of Otorhinolaryngology, the ears of patients with chronic otorrhea were evaluated visually and compared with the normal contralateral ears. Ears with otorrhea were also compared to ears with dry tympanic perforation of other patients. Ears with suppuration were evaluated for cholesteatoma. The duration of otorrhea was taken into account. The sensorineural hearing threshold was evaluated for the frequencies of 500, 1000, 2000, and 4000 Hz. A total of 98 patients with chronic otorrhea and 60 with dry tympanic membrane perforation were evaluated. From a statistical study, a correlation between sensorineural hearing loss and the chronic otorrhea was observed, in comparison both with contralateral normal ears and with dry perforated ears of other patients. There was no relationship with the duration of suppuration or with whether this was due to cholesteatoma. Sensorineural hearing loss occurs in ears with chronic otorrhea. The duration of otorrhea and the etiology of suppuration did not influence the hearing loss. The great majority of otorrhea cases begin during childhood.
Otomycosis With Tympanic Membrane Perforation: A Review of the Literature
Authors: Koltsidopoulos Petros , Skoulakis Charalampos
Published: May 2019

Objective:

The purpose of the present study was to assess the rate of tympanic membrane perforation in patients with otomycosis and to discuss the literature regarding the difficulties in managing this condition.

Data Sources:

Literature review from 1999 to 2019, Web of Science, PubMed, and Medline.

Study Selection:

We searched for eligible articles concerning the clinical entity of tympanic membrane perforation secondary to otomycosis. Case series and clinical trials were the types of articles included for this review.

Data Extraction:

All the articles described in the study selection were used for this review.

Data Synthesis:

Statistical techniques were not used.

Conclusion:

Based on the available literature, it seems that tympanic membrane perforation secondary to otomycosis is not uncommon. The presence of this complication is associated with 2 problems: Antimycotic solutions are irritant to middle ear and may be ototoxic to the cochlea. Although most cases of fungus caused tympanic membrane (TM) perforation resolve with proper medical treatment, in a few patients a tympanoplasty may be required.
The paradox and continuum of digital disengagement: denaturalising digital sociality and technological connectivity
Authors: Kuntsman Adi , Miyake Esperanza
Published: May 2019

This theoretical intervention puts forward a concept of ‘digital disengagement’ to discuss new socio-cultural, economic and political demarcations and implications surrounding the relationship between digital media, culture and society. At present, despite a proliferation of calls to reduce both the range of digital devices and communication platforms, and the time spent using them, and despite a growing body of academic work on disconnection or opt-out, disengagement from the digital is still conceptualised by media research as a spatiotemporal or an ideological aberration. To challenge this framework, we propose a paradigmatic shift. We invite digital media scholarship to denaturalise the digital by centring digital disengagement both as a complex phenomenon currently unfolding and as a conceptual entry point into thinking about sociality, agency, rights and everyday life more broadly. Mobilising digital disengagement as a theoretical lens, our piece provides the following: first, we critically assess the prevalent conflation of digitality with social networking, which leads to a limited understanding of disengagement as being only about disconnecting from social media platforms. Second, we challenge the normalisation of the technological in practices of disconnection, arguing instead that disengagement might be structured, but should not be determined, by the technological. Third, we demonstrate that digital disengagement is not a single phenomenon but a complex continuum of practices, motivations and effects. Understood as such, it has the potential to open new ways of imagining relations between technologies and freedoms, engagement and digitality and sociality and refusal.
Right main bronchus para-occluder fistula closure with a septal defect occluder
Authors: Bashenow Alexander Victorovich , Motus Igor Yakovlevich , Tsvirenko Anna Sergeevna , Medvinskiy Igor Davydovich , Dovbnya Sergey Alexandrovich , Dotsenko Ivan Alexandrovich
Published: May 2019

We present a case of successful closure of a para-occluder fistula. The bronchopleural fistula occurred after a right-sided pneumonectomy performed for multidrug-resistant tuberculosis. Initial closure of the bronchopleural fistula with the use of an atrial septal defect occluder 3 years later led to relapse of the fistula after 2 years. To manage the relapsing bronchopleural fistula, we partially destroyed the former nonfunctioning occluder, measured the size of the bronchial defect with a sizing balloon, and installed an atrial septal defect occluder of a larger size.
When virtue is not an option: Decision making in unhealthy food choices
Authors: Trabold Apadula Lauren , Martins Chrissy M
Published: May 2019

Background:

Health conscious consumers often make choices from constrained sets of food options, such as a restaurant menu, in which healthy options may not be present.

Aim:

The aim of this research was to examine how different decision strategies, such as selection versus rejection, influence the food option chosen when a choice set is restricted to unhealthy options. The mediating role of anticipated guilt was also explored.

Methods:

An experiment was conducted using a hypothetical choice scenario, in which participants were randomly assigned to a decision making strategy (select versus reject), health objective (diet versus indulge), and relative preference for the options (choice between two preferred options versus one preferred and one non-preferred option) was manipulated.

Results:

When using a selection strategy, consumers are more likely to choose their most preferred option, regardless of their health objectives, but when using a rejection strategy, health conscious consumers are more likely to avoid their most preferred option and consume a lesser liked alternative. Further, this effect is driven by reduced feelings of guilt. Important boundary conditions include consumer preference for the food options, as health conscious consumers will not reject their favorite option if they do not like the alternative.

Conclusions:

Decision making strategy influences health conscious consumers’ choices between unhealthy food options.
Cardiac-gated steady-state multifrequency magnetic resonance elastography of the brain: Effect of cerebral arterial pulsation on brain viscoelasticity
Authors: Schrank Felix , Warmuth Carsten , Tzschätzsch Heiko , Kreft Bernhard , Hirsch Sebastian , Braun Jürgen , Elgeti Thomas , Sack Ingolf
Published: May 2019

In-vivo brain viscoelasticity measured by magnetic resonance elastography (MRE) is a sensitive imaging marker for long-term biophysical changes in brain tissue due to aging and disease; however, it is still unknown whether MRE can reveal short-term periodic alterations of brain viscoelasticity related to cerebral arterial pulsation (CAP). We developed cardiac-gated steady-state MRE (ssMRE) with spiral readout and stroboscopic sampling of continuously induced mechanical vibrations in the brain at 20, 31.25, and 40 Hz frequencies. Maps of magnitude |G*| and phase ϕ of the complex shear modulus were generated by multifrequency dual visco-elasto inversion with a temporal resolution of 40 ms over 4 s. The method was tested in 12 healthy volunteers. During cerebral systole, |G*| decreased by 6.6 ± 1.9% (56 ± 22 Pa, p < 0.001, mean ± SD), whereas ϕ increased by 0.5 ± 0.5% (0.006 ± 0.005 rad, p = 0.002). The effect size of CAP-induced softening slightly decreased with age by 0.10 ± 0.05% per year ( p = 0.04), indicating lower cerebral vascular compliance in older individuals. Our data show for the first time that the brain softens and becomes more viscous during systole, possibly due to an effect of CAP-induced arterial expansion and increased blood volume on effective-medium tissue properties. This sensitivity to vascular-solid tissue interactions makes ssMRE potentially useful for detection of cerebral vascular disease.