bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of peptides containing oxo amino acids and their crystallographic analysis
Authors: Kalita Mrinal , Archana Archana , Dimri Astha , Vasudev Prema G. , Ramapanicker Ramesh
Published: January 2019

An isolated uncharged hydrogen bond acceptor such as the carbonyl functionality of an aldehyde or a keto group is absent in natural amino acids. Although glutamine and asparagine are known to hydrogen bond through the amide carbonyl group in their side chains, they also possess the amide NH2 group, which can act as a hydrogen bond donor. This makes the structural study of peptides containing an oxo residue, with an isolated carbonyl group in the side chain, interesting. Here, we report the synthesis of δ‐ and ε‐oxo amino acids and their incorporation into oligopeptides as the N‐terminal residue. The resultant oxo peptides were extensively studied using X‐ray crystallography to understand the interactions offered by the oxo group in peptide crystals. We find that the oxo groups are capable of providing additional hydrogen bonding opportunities to the peptides, resulting in increased intermolecular interactions in crystals. The study thus offers avenues for the utilization of oxo residues to introduce intermolecular interactions in synthetic peptides.
Reproducibility of Quantitative Systems Pharmacology Models: Current Challenges and Future Opportunities
Authors: Kirouac Daniel C. , Cicali Brian , Schmidt Stephan
Published: January 2019

The provision of model code is required for publication in CPT: Pharmacometrics & Systems Pharmacology, enabling quantitative systems pharmacology (QSP) model availability. A searchable repository of published QSP models would enhance model accessibility. We assess the feasibility of establishing such a resource based on 18 QSP models published in this journal. However, because of the diversity of software platforms (nine), file formats, and functionality, such a resource is premature. We evaluated 12 of the models (those coded in R, PK‐Sim/MoBi, and MATLAB) for functionality. Of the 12, only 4 were executable in that figures from the associated manuscript could be generated via a “run” script. Many researchers are aware of the challenges involved in repurposing published models. We offer some ideas to enable model sharing going forward, including annotation guidelines, standardized formats, and the inclusion of “run” scripts. If practitioners can agree to some minimum standards for the provision of model code, model reuse and extension would be accelerated.
Statistical considerations in a delayed‐start design to demonstrate disease modification effect in neurodegenerative disorders
Authors: Wang Deli , Robieson Weining , Zhao Jun , Wiener Catherine , Koch Gary
Published: January 2019

There has been a paradigm shift in diagnostic conceptualization of Alzheimer's disease (AD) based on the current evidence suggesting that structure and biology changes start to occur before clinical symptoms emerge. Consequently, therapeutic drug development is also shifting to treat early AD patients using biomarkers for enrichment in clinical trials. A similar paradigm shift is occurring for Parkinson disease. In the absence of acceptable biomarkers that could be combined with a clinical endpoint to demonstrate a disease modification (DM) effect in neurodegenerative disorders, a delayed‐start design can be applied to demonstrate a lasting effect on the disease course. The delayed‐start design includes two treatment periods, where in period 1, patients are randomized to receive an active treatment or placebo, and in period 2, placebo patients are switched to the active treatment while patients in the active treatment arm will continue the same treatment. The hypothesis is that patients who start the active treatment later will fail to catch up to the treatment benefit achieved by patients who receive the active treatment in both periods. A usual analytical approach has sought to demonstrate the divergence of slope during period 1 and the parallelism of slopes during period 2 as the DM effect. However, due to heterogeneity in timing and the magnitude of maximal effect among patients, nonlinear response over time could be observed within the two treatment arms in both periods. We propose an approach to evaluate the DM effect with the linearity assumption for treatment differences, but not for each arm separately.
Empirics of currency crises: A duration analysis approach
Authors: Karimi Mohammad , Voia Marcel‐Cristian
Published: January 2019

This paper empirically analyzes the origins of currency crises for a group ofOECDeconomies from 1970 through 1998. We apply duration analysis to examine how the probability of a currency crisis depends on the length of non‐crisis periods, contagion channels, and macroeconomic fundamentals. Our findings confirm the negativeduration dependenceof a currency crisis—the likelihood of speculative attack sharply increases at the beginning of non‐crisis periods and then declines over time until it abruptly rises again. The results also indicate the hazard of a crisis increase with high values of the volatility of unemployment rates, inflation rates, contagion factors—which mostly work through trade channels, unemployment rates, real effective exchange rate, trade openness, and size of economy. To address concerns regarding validity of the identified crisis episodes, we exploit crisis episodes that are identified by a more objective approach based on the extreme value theory. Our results are robust under various specifications including two different crisis event sets that are identified on monthly and quarterly basis.
Alphasat Aldo Paraboni, an advanced Q/V band mission space segment
Authors: Rivera Juan J. , Martellucci Antonio , Sivac Philippe , Benzi Edoardo , Pandolfi Alberto , de Bernardo Domenico , Falzini Stefano , Codispoti Giuseppe
Published: January 2019

This paper provides an overview of the space segment of the Aldo Paraboni mission on the Alphasat satellite and the technology programme that has developed one of the most powerful geostationary satellites in Europe. The Aldo Paraboni technology demonstration payload, funded by ASI under European Space Agency's Advanced Research in Telecommunications System Programme, was embarked as a hosted payload on the Alphasat satellite, launched on 25 July 2013. The Aldo Paraboni payload is composed of two main elements, an experimental communication payload operating at Q/V bands (COMEX) and a scientific payload formed by 2 beacons at Ka and Q bands (SCIEX). The Aldo Paraboni payload is a key technology element of the Aldo Paraboni Mission, which covers two main objectives: the communication segment of the mission aims at assessing the performance of satellite communication links at Q/V bands and investigating use Fade Mitigation Techniques (FMT, eg, Adaptive Coding and Modulation defined in DVB‐S2 standard), while the scientific segment aims at characterizing in time, space, and frequency the K and Q band radio channel over Europe to permit development and improvement of propagation channels for slant paths.
Product proliferation, complexity, and deterrence to imitation in differentiated‐product oligopolies
Authors: Piazzai Michele , Wijnberg Nachoem M.
Published: January 2019

Research Summary

Game theory suggests that, in oligopolistic markets characterized by nonprice competition, dominant incumbents can use product proliferation to occupy a region of the product space (i.e., a subspace) and deter rivals from imitating their products. In part, this is because product proliferation makes the introduction of close substitutes comparatively less profitable; in part, it is because the strategy conveys a threat of retaliation to potential imitators. Yet this threat is only credible if the proliferator has high costs of exit from the occupied region of space. We hypothesize that complexity, as a property of product (sub)spaces, generates exit costs for the proliferator and increases the deterrent power of its strategy. We test this hypothesis by studying sequential product introductions in the U.S. recording industry, 2004–2014.

Managerial Summary

Differentiated‐product markets are often concentrated in the hands of a few dominant organizations, which strive to keep on equal footing by offering similar products. In these markets, a product proliferation strategy can help one of the dominant incumbents claim a particular submarket as its territory. Investing heavily in that submarket communicates a threat that the proliferator will retaliate against invaders to protect these investments. However, this threat is not credible enough to deter rivals unless the occupied submarket is sufficiently complex in terms of product attributes, as precisely this kind of complexity makes it harder for proliferators to back down if challenged. We find evidence of this mechanism in an analysis of product competition among major record companies and discuss implications for strategic decision‐making.

RESOURCES

This article has earned an Open Data badge for making publicly available the digitally‐shareable data necessary to reproduce the reported results. The data is available at https://github.com/piazzai/smj-18-19552. Learn more about the Open Practices badges from the Center for Open Science: https://osf.io/tvyxz/wiki.
The clinical outcome of pregnancies of unknown location: an audit of 112 cases
Authors: Young Lee , Necas Martin
Published: January 2019

Introduction

Pregnancy of unknown location (PUL) is a descriptive term applied when a woman presents with a positive pregnancy test but no signs of either intrauterine pregnancy (IUP) or ectopic pregnancy (EP) on ultrasound. This implies a level of diagnostic uncertainty requiring further investigation, with the main concern being an undetected EP.

Method

We examined the outcome of 112 pregnancies of unknown location (PUL) in a tertiary teaching hospital in New Zealand.

Results

Of 585 women referred to our service with a clinical suspicion of EP, 112 (19%) were categorised as PULs. The final outcomes in these women were complete miscarriage (52%), IUP (13%), presumed EP (11%), incomplete miscarriage (11%), confirmed EP (10%), and molar pregnancy (2%). A large proportion of women (42%) required a second ultrasound examination, and of those, 36% further required a third examination. The distribution of bHCG at presentation and symptomatology demonstrated considerable overlap in women with different clinical outcomes.

Conclusion

PUL continues to be a challenging and resource‐intensive clinical scenario. The rate of undiagnosed EP requiring intervention is around 10%, and the probability that a PUL represents a small nonvisualised ongoing IUP is relatively low (15%).
Teaching science skills and knowledge to students with developmental disabilities: A systematic review
Authors: Apanasionok Magdalena M. , Hastings Richard P. , Grindle Corinna F. , Watkins Richard C. , Paris Andreas
Published: January 2019

A comprehensive review of the literature was conducted to identify current practice on teaching science to students with intellectual disability (ID) and/or Autism Spectrum Disorder (ASD) in relation to two review questions—students' science outcomes and students' and teachers' experiences of the interventions. Six databases related to education, psychology, and science were systematically searched. A detailed protocol can be viewed on PROSPERO (registration number: CRD42017057323). Thirty studies were identified that reported on science interventions and 20 on student/teacher experiences of the interventions. The majority of the studies targeted science vocabulary and concepts. Other targets included inquiry skills and comprehension skills. The majority of the interventions used components of systematic instruction (n = 23). Five studies focused on self‐directed learning and two on comprehension‐based instruction. Students and teachers reported positive experiences of the interventions. The findings suggest that components of systematic instruction in particular might be effective in teaching science content to students with ID and/or ASD. Further research is needed to explore the effectiveness of identified interventions on teaching more complex science skills and with students with severe disabilities. Some limitations related to the search strategy are highlighted.
Prevention of ochratoxin A‐induced oxidative stress‐mediated apoptotic processes and impairment of embryonic development in mouse blastocysts by liquiritigenin
Authors: Huang Chien‐Hsun , Wang Fu‐Ting , Chan Wen‐Hsiung
Published: January 2019

Ochratoxin A (OTA), a mycotoxin constituent of a range of food commodities, including coffee, wine, beer, grains, and spices, exerts toxicological and pathological effects in vivo, such as nephrotoxicity, hepatotoxicity, and immunotoxicity. In a previous report, we highlighted the potential of OTA to induce apoptosis via reactive oxygen species (ROS) generation in mouse blastocysts that led to impaired preimplantation and postimplantation embryo development in vitro and in vivo. Here, we have shown that liquiritigenin (LQ), a type of flavonoid isolated from Glycyrrhiza radix, effectively protects against OTA‐mediated apoptosis and inhibition of cell proliferation in mouse blastocysts. Preincubation of blastocysts with LQ clearly prevented OTA‐triggered impairment of preimplantation and postimplantation embryonic development and fetal weight loss, both in vitro and in vivo. Detailed investigation of regulatory mechanisms revealed that OTA mediated apoptosis and embryotoxicity through ROS generation, loss of mitochondrial membrane potential (MMP), and activation of caspase‐9 and caspase‐3, which were effectively prevented by LQ. The embryotoxic effects of OTA were further validated in an animal model in vivo. Intravenous injection of dams with OTA (3 mg/kg/day) led to apoptosis of blastocysts, impairment of embryonic development from zygote to blastocyst stage and decrease in day 18 fetal weight. Notably, preinjection of dams with LQ (5 mg/kg/day) effectively prevented OTA‐induced apoptosis and toxic effects on embryo development. Our collective results clearly demonstrate that OTA exposure via injection has the potential to damage preimplantation and postimplantation embryonic development against which LQ has a protective effect.
NLRP3 inflammasome activation involved in LPS and coal tar pitch extract‐induced malignant transformation of human bronchial epithelial cells
Authors: Duan Shuyin , Wang Na , Huang Li , Shao Hua , Zhang Peng , Wang Wei , Wu Yongjun , Wang Jing , Liu Hong , Zhang Qiao , Feng Feifei
Published: January 2019

Inflammatory microenvironment has been found as a new characteristic of cancer; however, the mechanisms of inflammation‐related lung cancer remain unclear. To explore the role of NLRP3 inflammsome activation in inflammation‐related lung carcinogenesis, a cell model was set up. Human bronchial epithelial cells (BEAS‐2B) were stimulated with 1 μg/mL lipopolysaccharide (LPS) for 24 hours, and then treated with 2.4 μg/mL coal tar pitch extract (CTPE) for 24 hours, after removal of LPS and CTPE, the cells were numbered passage 1 and were passaged and treated in this way until passage 30, which was called LPS + CTPE group. DMSO and Saline were used as vehicle controls. Malignant transformation of cells in passage 30 was evaluated by morphological change, platelet clone formation assay, and tumor formation in nude mice. The mRNA levels of NLRP3 and IL‐1β were detected by real time‐PCR. The combination of NLRP3 and caspase‐1 were determined using immunofluorescence and confocal. The protein expression of NLRP3, cleaved caspase‐1(p10), and cleaved IL‐1β was detected using Western blot. It was shown that CTPE, LPS + CTPE‐stimulated BEAS‐2B cells of passage 30 changed a lot morphologically. The clone formation rates, the rates of positive cells of NLRP3 and caspase‐1 combination, the mRNA levels of NLRP3 and IL‐1β, the protein expression of NLRP3, cleaved caspase‐1(p10) and cleaved IL‐1β of cells exposed with CTPE and LPS + CTPE at passage 30 were significantly increased compared to vehicle controls. Furthermore, the ability of tumor formation in nude mice, the rates of clone formation and positive cells, mRNA and protein levels of NLRP3 inflammasome activation‐related factors in LPS + CTPE‐induced cells were all higher than those in cells stimulated with CTPE alone. In conclusion, the cell model of inflammation‐related lung cancer is set up successfully, and NLRP3 inflammasome activation may be involved in the malignant transformation of BEAS‐2B cells which induced by CTPE alone or LPS combined with CTPE.
Vitamin D protects against particles‐caused lung injury through induction of autophagy in an Nrf2‐dependent manner
Authors: Tao Shasha , Zhang Hong , Xue Lian , Jiang Xiaoyan , Wang Hongyan , Li Bingyan , Tian Hailin , Zhang Zengli
Published: January 2019

Fine particulate matter is a well‐known air pollutant threatening public health. Studies have confirmed long‐term exposure to the particles could decrease the pulmonary function, induce asthma exacerbation, and chronic obstructive pulmonary disease, as well as increase the incidence and mortality of lung cancer. A clinical study has explored that the prevalence and risks of vitamin D (VD) deficiency in various chronic disease and toxins induced tissue damage. Our current study aimed to explore the mechanism and further therapeutic potential of VD administration to ameliorate fine particles exposure induced pulmonary damage in vivo and in vitro. To elucidate the effects and mechanisms of VD in particles‐induced pulmonary damage, a murine model was established with fine particles intratracheal instillation along with VD intramuscular injection. Our study demonstrated that treatment with VD attenuated particles‐induced pulmonary damage and promoted tissue repair by repressing of TGFβ1 signaling pathway and upregulation of MMP9 expression. VD treatment could also regulate the autophagy‐related signals along with activation of Nrf2 transcription factor. Furthermore, the results from the in vitro study demonstrated that VD protected against particles‐induced cells' damage through the induction of autophagy in an Nrf2‐dependent manner. VD treatment caused the degradation of P62 and its bound Keap1, which decreased the Nrf2 ubiquitination and increasing its protein stability. Our work explored a novel potential mechanism in the protection of VD in particles‐induced pulmonary injury and tissue repair, and could further bring insights into exploring antifine particles exposure caused inflammation among other natural products and contributes to inflammation disease medical therapies.
Reducing burnout amongst clinicians
Authors: Kirby Roger
Published: January 2019

In this editorial, Roger Kirby, Editor on Trends in Urology and Men's Health, discusses the current problem of burnout and job dissatisfaction among healthcare professionals and what can be done about it.
Building personal resilience as a clinician and educator
Authors: Kirby Roger
Published: January 2019

Burnout among healthcare professionals is a signifcant problem that can affect anyone in the medical profession – from medical students to senior doctors. Here the author describes burnout, its manifestations, and the methods that institutions and individuals can use to avoid it.
Urinary catheters: common urology problems in the community
Authors: Woodhouse Christopher
Published: January 2019

Urinary catheters are widely used and complications with them are common. In this article the author considers the common problems encountered when using urinary catheters and suggests what can be done about them.
Pilonidal sinus disease: a multidisciplinary approach
Authors: Marza Liliana
Published: January 2019

Pilonidal sinus disease has a significant effect on the quality of life of patients due to frequent episodes of painful abscesses requiring time off work and limiting of daily activities. It affects mainly young healthy men and the prevalence has persistently increased over the past 50 years. A high rate of recurrence following all types of surgery is reported. In this article the author describes why a multidisciplinary approach to management
is needed.
So you want to be an app developer?
Authors: Foster Luke , Green James
Published: January 2019

Digital health applications (or apps) are becoming more and more popular with health professionals and patients alike. Indeed, many apps have been produced by healthcare professionals themselves. So, for those who feel the urge to develop their own app the author provides 10 steps to doing just that.
The history of the prostate, part one: say what you see
Authors: Goddard Jonathan Charles
Published: January 2019

‘Glands which pour a humor into the urinary passages of the male to excite the sexual act’ is one very early description of the prostate gland. In this article Jonathan Goddard describes the early history of the prostate gland as our understanding of its structure and function developed over time.
A manifesto for men's health
Authors: de Winter Louise
Published: January 2019

The Urology Foundation (TUF) has been supporting urological healthcare professionals and researchers for over 25 years. In this article the TUF Chief Executive describes some of the work undertaken by TUF and calls for support in raising greater awareness of urological disease.
Sociopolitical organization, landscape change, and hydraulic engineering in the Teotihuacan Valley, Mexico: 1250 B.C.–A.D. 1810
Authors: Mejía Ramón Andrés G. , Johnson Nadia E.
Published: January 2019

The Teotihuacan Valley has witnessed the rise and fall of various civilizations since it was first inhabited by sedentary societies 3,500 years ago. Given its location in a semi‐arid environment, Teotihuacan has featured prominently in debates about the role of water and water management in the development of sedentism, culture, primary states, and large, complex societies. While many previous discussions tended to echo Wittfogel's “hydraulic hypothesis,” focusing on the ability of an elite few to monopolize water resources, we instead turn to a growing corpus of research showing varied water management strategies through time potentially resulting in distinct patterns of social organization. In this palimpsest landscape hydraulic and agricultural strategies were constrained not merely by present environmental conditions, but also by very real and material legacies of previous behavior. We discuss the state of research regarding these adaptations (and social responses) to water scarcity from the Early‐to‐Middle Formative Period (1250–650 B.C.) through the independence of Mexico (A.D. 1810), noting how previous fundamental assumptions about agriculture and hydraulic management in the Teotihuacan Valley have led to a significant number of neglected concepts and potential adaptations. If we are to address the current destruction of the Teotihuacan Valley's ecological and cultural resources in response to national development and climate change, a historical‐ecological perspective is necessary to disentangle the relevant processes that have shaped the landscape—and the cultures residing within it—to this day.

This article is categorized under:

Science of Water > Water and Environmental Change

Human Water > Water as Imagined and Represented

Engineering Water > Planning Water
Activated sludge morphology significantly impacts oxygen transfer at the air–liquid boundary
Authors: Campbell Ken , Wang Jianmin , Liu Guoqiang , Daigger Glen
Published: January 2019

Oxygen transfer is a key process determining the energy use of a biological wastewater treatment process. In this research, we investigated the effect of sludge morphology, especially the role of filamentous microorganisms, on oxygen transfer using bench‐scale complete‐mix activated sludge reactors with solids retention times (SRTs) of 10‐, 20‐, and 40‐days, respectively. Results indicated 5%–10% reduced aeration need in the 40‐day SRT reactor, compared with 10‐ and 20‐day SRT reactors to maintain the same dissolved oxygen level, due to the improvement in sludge settleability and oxygen transfer efficiency (OTE). Filamentous microorganisms adversely impacted OTE via an increase in apparent viscosity of the mixed liquor, which resulted in an increase in the air bubble size and liquid film thickness and, therefore, limited oxygen transfer at the air–liquid boundary. A statistical analysis also confirmed that the mixed liquor viscosity is a statistically significant parameter links to OTE.

Practitioner points

Filamentous organisms reduce oxygen transfer via increasing mixed liquor viscosity, which increases air bubble size and liquid film thickness at the air‐liquid boundary.

Increasing solids retention time reduces filament density.

As a result, very long solids retention time promotes oxygen transfer.
Detection and quantification of heavy metal elements in gallstones using X‐ray fluorescence spectrometry
Authors: Jaswal Brij Bir Singh , Rai Pradeep Kumar , Singh Tejbir , Zorba Vassilia , Singh Vivek Kumar
Published: January 2019

Gallbladder cancer, which is associated with the heavy metal toxicity, is one of the most dangerous malignancies. High occurrence of gallstones in the gallbladder is a well‐recognized risk factor for gallbladder cancer. Accumulation of heavy and toxic metals in the biliary system is one of the main causes of gallstone formation and leads to gallbladder cancer if it remains untreated. In this work, we investigate heavy and toxic metals in gallstones to identify their association as potential risk factors for gallbladder cancer. Detection and quantification of the heavy and toxic chemicals present in gallstones are important to define etiopathogenic factors that, in turn, are useful to identify preventive and therapeutic strategies. We quantified the heavy metals in gallstones collected from patients of different age groups and dietary habits. We carried out chemical composition studies of trace and heavy metal elements present in gallstones by applying Fourier transform infrared (FTIR) spectroscopy and wavelength‐dispersive X‐ray fluorescence (WD‐XRF) spectrometry. We also compared our experimental results with the results obtained from atomic absorption spectroscopy, as well as values previously reported in literature. These findings demonstrate the potential of WD‐XRF spectrometry and FTIR spectroscopy as important emerging diagnostic tools in the field of gastroenterology.
Analysis of precious metals from the tomb of the “Lady of Cao” by X‐ray microtomography and digital radiography
Authors: R. Azeredo Soraia , Cesareo Roberto , F. Jordan Régulo , Fernandez Arabel , E. Gigante Giovanni , Bustamante Angel , T. Lopes Ricardo
Published: January 2019

Investigative analyses of metallic objects from the tomb of a queen of the Moche civilization, who lived around 100 to 300 AD in the northern coast of current Peru, known as Lady of Cao, have been carried out by researchers in the last 4 years using various destructive techniques. Many of these objects found inside the tomb are jewelry produced using silver, gilded copper, copper, and gold sheets. The application of X‐ray microtomography (μCT) and X‐ray digital radiography techniques using a portable system had the objective of obtaining more information on the structures of the objects studied, and thus to obtain some evidences about the production methods used by Moche artisans. In this way, radiographic and microtomographic images were acquired, and qualitative and quantitative analyses were performed. A fish in gold and a nose decoration in silver were examined by radiographic methods, whereas a silver earring and a gold needle were analyzed by μCT. Important information on the structure of these objects were gained.
Interaction effect of familism and socioeconomic status on academic outcomes of adolescent children of Latino immigrant families
Authors: Toyokawa Noriko , Toyokawa Teru
Published: January 2019

Introduction

Previous research has shown inconsistent findings of the effect of familism on academic outcomes among adolescents from Latino immigrant families. Guided by social capital theory and the concept of gendered familism, the current study examined differential effects of family obligation and family cohesion as subcomponents separately. This study also investigated the moderating effect of familial SES on the association of each component of familism and academic outcomes by gender.

Methods

Participants were 1801 adolescents from Latino immigrant families (Mage = 14.1 years, SD = 0.83, range = 14–17) drawn from the Children of Immigrant Longitudinal Studies. The current study employed a series of multiple regression analyses to examine the effects of familism, assessed by family obligation and family cohesion, on adolescents' grade point average (GPA), educational expectations and aspirations. Multigroup analyses were also conducted to examine gender differences in the effect of familism on adolescents’ academic outcomes.

Results

Analyses revealed the positive main effect of family cohesion and the negative effect of family obligations on Latino and Latina adolescents' GPA and educational expectations. For Latino adolescents, negative effect of family obligation on GPA was stronger for adolescents from high‐SES families than those from low‐SES families.

Conclusion

It is imperative for researchers to conceptualize familism and operationalize the construct clearly. The effect of differences in family context and gender role expectation also needs to be considered in examining the association between familism and the academic outcomes of adolescents from immigrant families.
Spreading in space–time periodic media governed by a monostable equation with free boundaries, Part 2: Spreading speed
Authors: Ding Weiwei , Du Yihong , Liang Xing
Published: January 2019

This is Part 2 of our work aimed at classifying the long-time behavior of the solution to a free boundary problem with monostable reaction term in space–time periodic media. In Part 1 (see [2]) we have established a theory on the existence and uniqueness of solutions to this free boundary problem with continuous initial functions, as well as a spreading-vanishing dichotomy. We are now able to develop the methods of Weinberger [15,16] and others [6–10] to prove the existence of asymptotic spreading speed when spreading happens, without knowing a priori the existence of the corresponding semi-wave solutions of the free boundary problem. This is a completely different approach from earlier works on the free boundary model, where the spreading speed is determined by firstly showing the existence of a corresponding semi-wave. Such a semi-wave appears difficult to obtain by the earlier approaches in the case of space–time periodic media considered in our work here.
Longitudinal study of hearing loss and subjective cognitive function decline in men
Authors: Curhan Sharon G. , Willett Walter C. , Grodstein Francine , Curhan Gary C.
Published: January 2019

Introduction

We examined the relation between self‐reported hearing loss, hearing aid use, and risk of subjective cognitive function (SCF) decline.

Methods

We conducted an 8‐year (2008–2016) longitudinal study of 10,107 men aged ≥62 years who reported their hearing status in 2006 and had no subjective cognitive concerns in 2008. Change in SCF scores was assessed by a 6‐item questionnaire, and subjective decline was defined as new report of at least one SCF concern during follow‐up.

Results

Hearing loss was associated with higher risk of SCF decline. Compared with no hearing loss, the multivariable‐adjusted relative risk (95% CI) of incident SCF decline was 1.30 (1.18, 1.42), 1.42 (1.26, 1.61), and 1.54 (1.22, 1.96) among men with mild, moderate, and severe hearing loss (no hearing aids), respectively (P‐trend < .001). Among men with severe hearing loss who used hearing aids, the multivariable‐adjusted relative risk (95% CI) was 1.37 (1.18, 1.60).

Discussion

Hearing loss was associated with substantially higher risk of subsequent subjective cognitive decline in men.
Digital Authorship
Authors: Skains R. Lyle
Published: January 2019

This Element looks at contemporary authorship via three key authorial roles: indie publisher, hybrid author, and fanfiction writer. The twenty-first century's digital and networked media allows writers to disintermediate the established structures of royalty publishing, and to distribute their work directly to - and often in collaboration with - their readers. This demotic author, one who is 'of the people', often works in genres considered 'popular' or 'derivative'. The demotic author eschews the top-down communication flow of author > text > reader, in favor of publishing platforms that generate attention capital, such as blogs, fanfiction communities, and social media.
Chaotic Dynamics
Authors: Goodson Geoffrey R.
Published: January 2019

This undergraduate textbook is a rigorous mathematical introduction to dynamical systems and an accessible guide for students transitioning from calculus to advanced mathematics. It has many student-friendly features, such as graded exercises that range from straightforward to more difficult with hints, and includes concrete applications of real analysis and metric space theory to dynamical problems. Proofs are complete and carefully explained, and there is opportunity to practice manipulating algebraic expressions in an applied context of dynamical problems. After presenting a foundation in one-dimensional dynamical systems, the text introduces students to advanced subjects in the latter chapters, such as topological and symbolic dynamics. It includes two-dimensional dynamics, Sharkovsky's theorem, and the theory of substitutions, and takes special care in covering Newton's method. Mathematica code is available online, so that students can see implementation of many of the dynamical aspects of the text.
Calving controlled by melt-under-cutting: detailed calving styles revealed through time-lapse observations
Authors: How Penelope , Schild Kristin M. , Benn Douglas I. , Noormets Riko , Kirchner Nina , Luckman Adrian , Vallot Dorothée , Hulton Nicholas R. J. , Borstad Chris
Published: January 2019

We present a highly detailed study of calving dynamics at Tunabreen, a tidewater glacier in Svalbard. A time-lapse camera was trained on the terminus and programmed to capture images every 3 seconds over a 28-hour period in August 2015, producing a highly detailed record of 34 117 images from which 358 individual calving events were distinguished. Calving activity is characterised by frequent events (12.8 events h−1) that are small relative to the spectrum of calving events observed, demonstrating the prevalence of small-scale calving mechanisms. Five calving styles were observed, with a high proportion of calving events (82%) originating at, or above, the waterline. The tidal cycle plays a key role in the timing of calving events, with 68% occurring on the falling limb of the tide. Calving activity is concentrated where meltwater plumes surface at the glacier front, and a ~ 5 m undercut at the base of the glacier suggests that meltwater plumes encourage melt-under-cutting. We conclude that frontal ablation at Tunabreen may be paced by submarine melt rates, as suggested from similar observations at glaciers in Svalbard and Alaska. Using submarine melt rate to calculate frontal ablation would greatly simplify estimations of tidewater glacier losses in prognostic models.
More Seriously Wrong, More Importantly Right
Authors: HURKA THOMAS
Published: January 2019

Commonsense morality divides acts into those that are right and those that are wrong, but it thinks some wrong acts are more seriously wrong than others, for example, murder than breaking a promise. This has several implications. If an act is more seriously wrong, you should feel more guilt about it and, other things equal, you are more blameworthy for it and can deserve more punishment; we may also need to consider serious wrongness when choosing in conditions of risk or moral uncertainty. This paper examines how one act can be more seriously wrong than another, and, when it is, what makes this so. More specifically, it considers a number of different views about the ground of serious wrongness and explores the possibility that this may be different when acts violate deontological versus consequentialist duties. It also asks whether there is a parallel concept that admits of degrees on the side of rightness, one of being, as we can say, more importantly right. It aims to expand the scope of deontic theory from binary questions about right versus wrong to ones whose answers admit of degrees.
Palliative and end-of-life care education in Canadian emergency medicine residency programs: A national cross-sectional survey
Authors: Baylis Jared , Harris Devin R. , Chen Charlie , Ting Daniel K. , Clark Kevin , Kwan Anthony , Crawford Skye , Williscroft David
Published: January 2019

Objectives

Emergency physicians play an important role in providing care at the end-of-life as well as identifying patients who may benefit from a palliative approach. Several studies have shown that emergency medicine (EM) residents desire further training in palliative care. We performed a national cross-sectional survey of EM program directors. Our primary objective was to describe the number of Canadian postgraduate EM training programs with palliative and end-of-life care curricula.

Methods

A 15-question survey in English and French was sent by email to all program directors of both the Canadian College of Family Physicians emergency medicine (CCFP(EM)) and the Royal College of Physicians and Surgeons of Canada emergency medicine (RCPSC-EM) postgraduate training programs countrywide using FluidSurveys™ with a modified Dillman approach.

Results

We received a total of 26 responses from the 36 (response rate = 72.2%) EM postgraduate programs in Canada. Ten out of 26 (38.5%) programs had a structured educational program pertaining to palliative and end-of-life care. Lectures or seminars were the exclusive choice to teach content. Clinical palliative medicine rotations were mandatory in one out of 26 (3.8%) programs. The top two barriers to implementation of palliative and end-of-life care curricula were lack of time (84.6%) and curriculum development concerns (80.8%).

Conclusions

Palliative and end-of-life care training within EM has been identified as an area of need. This cross-sectional survey demonstrates that a minority of Canadian EM programs have palliative and end-of-life care curricula. It will be important for all EM training programs, RCPSC-EM and CCFP(EM), in Canada, to develop an agreed upon set of competencies and to structure their curricula around them.
The Mental Health Impact of Hurricane Maria on Puerto Ricans in Puerto Rico and Florida
Authors: Scaramutti Carolina , Salas-Wright Christopher P. , Vos Saskia R. , Schwartz Seth J.
Published: January 2019

Objectives

The aim of this study was to compare the effect of Hurricane Maria on internalizing and posttraumatic stress disorders (PTSD) among Puerto Ricans who moved to Florida after the storm versus those who stayed on the island.

Methods

In March through April 2018 (6 months after Hurricane Maria), an online survey was used to assess the effects of the storm on mental health. A sample of 213 displaced Puerto Ricans living in urban and rural/suburban areas in Florida, as well as urban and rural areas of Puerto Rico, participated in the study.

Results

Rates of PTSD were high in both sites (Florida, 65.7%; Puerto Rico, 43.6%); however, participants in Florida were far more likely than those in Puerto Rico to meet diagnostic criteria for PTSD (OR, 2.94; 95% CI, 1.67-5.26). Among participants in both Florida and Puerto Rico, those living in urban areas were more likely than those in rural/suburban areas to meet criteria for PTSD and generalized anxiety disorder.

Conclusions

Results suggest that post-Hurricane Maria adjustment and adaptation may have been more psychologically taxing for Puerto Ricans who moved to Florida than it was for those who remained on the island, and more difficult for those in urban areas than it was for those in suburban or rural areas. (Disaster Med Public Health Preparedness. 2019;13:24–27)
A Life at the Company: Oral History and Sense Making
Authors: KROEZE RONALD , VERVLOET JASMIJN
Published: January 2019

This article explores the ways that oral history can help business historians to better understand how employees experience and make sense of their life at the company in relation to a company’s identity. The research is based on two case studies. The first concentrates on Heineken. Specifically, it focuses on the closing of the Heineken brewery in Amsterdam in 1988. The second case was a commissioned project to write a book for the eightieth anniversary of the Amsterdam-based consultancy firm Van de Bunt Adviseurs. This project was concluded in 2016 with a publication that, like the research itself, was inspired by a cultural history approach and thus paid attention to founder narratives, sensemaking, and corporate identity construction. The article shows that oral history can broaden knowledge, especially of how employees experienced life at the company and how they made sense of it while referring to the (changing) company’s identity. Through the oral history method, employees were given a voice that showed how the same events were (differently) experienced. Moreover, the oral histories made the personal impact of abstract developments more concrete, notably issues such as internationalization, mergers and acquisitions, changing workings conditions, scaling up or down, or closure. Stories about the founders and the ample use of the family metaphor, which stood out in both cases, expressed employees’ feelings of being part of a company with a specific identity, as well as a longing for it. The article concludes with several suggestions that should be taken into account when conducting oral history research.
Snowball Sampling in Business Oral History: Accessing and Analyzing Professional Networks in the Australian Property Industry
Authors: BAILEY MATTHEW
Published: January 2019

This article reports on the methodology for recruiting oral history interviewees for a project on the history of shopping center development in Australia. Snowball sampling produced a data set that added value to extant archival and media sources, rendering detailed information about firm operations, strategies, and innovations. The construction of the sample was also revealing of the industry itself, with interviewee referral chains connecting individuals across firms, industry sectors, and generations. These links marked not only social connections but also paths through which knowledge was transferred via mentoring or shared experience, personal friendships that developed in workplaces, and professional contacts that evolved within a complex and constantly changing industry. Snowball sampling, though, also proved to be selective and contingent on the social networks of interviewees, requiring ongoing management of the chain referral process.
GAMES AND RAMSEY-LIKE CARDINALS
Authors: NIELSEN DAN SAATTRUP , WELCH PHILIP
Published: January 2019

We generalise the α-Ramsey cardinals introduced in Holy and Schlicht (2018) for cardinals α to arbitrary ordinals α, and answer several questions posed in that paper. In particular, we show that α-Ramseys are downwards absolute to the core model K for all α of uncountable cofinality, that strategic ω-Ramsey cardinals are equiconsistent with remarkable cardinals and that strategic α-Ramsey cardinals are equiconsistent with measurable cardinals for all α > ω. We also show that the n-Ramseys satisfy indescribability properties and use them to provide a game-theoretic characterisation of completely ineffable cardinals, as well as establishing further connections between the α-Ramsey cardinals and the Ramsey-like cardinals introduced in Gitman (2011), Feng (1990), and Sharpe and Welch (2011).
Coarse fundamental groups and box spaces
Authors: Delabie Thiebout , Khukhro Ana
Published: January 2019

We use a coarse version of the fundamental group first introduced by Barcelo, Kramer, Laubenbacher and Weaver to show that box spaces of finitely presented groups detect the normal subgroups used to construct the box space, up to isomorphism. As a consequence, we have that two finitely presented groups admit coarsely equivalent box spaces if and only if they are commensurable via normal subgroups. We also provide an example of two filtrations (Ni) and (Mi) of a free groupFsuch thatMi > Nifor alliwith [Mi:Ni] uniformly bounded, but with$\squ _{(N_i)}F$not coarsely equivalent to$\squ _{(M_i)}F$. Finally, we give some applications of the main theorem for rank gradient and the first ℓ2Betti number, and show that the main theorem can be used to construct infinitely many coarse equivalence classes of box spaces with various properties.
Hausdorff operators on holomorphic Hardy spaces and applications
Authors: Hung Ha Duy , Ky Luong Dang , Quang Thai Thuan
Published: January 2019

The aim of this paper is to characterize the non-negative functions φ defined on (0,∞) for which the Hausdorff operator
$${\rm {\cal H}}_\varphi f(z) = \int_0^\infty f \left( {\displaystyle{z \over t}} \right)\displaystyle{{\varphi (t)} \over t}{\rm d}t$$is bounded on the Hardy spaces of the upper half-plane ${\rm {\cal H}}_a^p ({\open C}_ + )$, $p\in [1,\infty ]$. The corresponding operator norms and their applications are also given.
Spatial interdependence and instrumental variable models
Authors: Betz Timm , Cook Scott J. , Hollenbach Florian M.
Published: January 2019

Instrumental variable (IV) methods are widely used to address endogeneity concerns. Yet, a specific kind of endogeneity – spatial interdependence – is regularly ignored. We show that ignoring spatial interdependence in the outcome results in asymptotically biased estimates even when instruments are randomly assigned. The extent of this bias increases when the instrument is also spatially clustered, as is the case for many widely used instruments: rainfall, natural disasters, economic shocks, and regionally- or globally-weighted averages. Because the biases due to spatial interdependence and predictor endogeneity can offset, addressing only one can increase the bias relative to ordinary least squares. We demonstrate the extent of these biases both analytically and via Monte Carlo simulation. Finally, we discuss a general estimation strategy – S-2SLS – that accounts for both outcome interdependence and predictor endogeneity, thereby recovering consistent estimates of predictor effects.
Non-Zero Radial Solutions for Elliptic Systems with Coupled Functional BCs in Exterior Domains
Authors: Cianciaruso Filomena , Infante Gennaro , Pietramala Paolamaria
Published: January 2019

We prove new results on the existence, non-existence, localization and multiplicity of non-trivial radial solutions of a system of elliptic boundary value problems on exterior domains subject to non-local, nonlinear, functional boundary conditions. Our approach relies on fixed point index theory. As a by-product of our theory we provide an answer to an open question posed by do Ó, Lorca, Sánchez and Ubilla. We include some examples with explicit nonlinearities in order to illustrate our theory.
POVERTY'S PASTS: A CASE FORLONGUE DURÉESTUDIES
Authors: STEPHENS RHIANNON
Published: January 2019

This article examines how historians have approached the history of poverty in Africa before European colonisation. From an earlier focus on the emergence of class difference to more recent studies on the emergence of poverty, scholars have demonstrated the longevity of economic inequality in Africa. This historiography counters a linear view of the growth of economic inequality and the idea that poverty is a necessary corollary of wealth. The article then considers how historians have studied the meanings of poverty within particular societies to the nineteenth century allowing us to move beyond the inadequacy of quantitative data. It ends by arguing for morelongue duréestudies of poverty in Africa with a focus on the qualitative and on the internal dynamics of particular societies. This will improve our knowledge about how colonial rule changed the experience and reality of poverty for people across the continent and form a basis for comparative studies.