bluuebunny/crossref_metadata_2025 huggingface dataset:
Imprint of magnetic flux expulsion at the core–mantle boundary on geomagnetic field intensity variations
Authors: Troyano M , Fournier A , Gallet Y , Finlay C C
Published: March 2020

During the last decade, rapid or extreme geomagnetic field intensity variations associated with rates greater than the maximum currently observed have been inferred from archeomagnetic data in the Near-East and in Western Europe. The most extreme events, termed geomagnetic spikes, are defined as intensity peaks occurring over a short time (a few decades), and are characterized by high variation rates, up to several μT yr–1. Magnetic flux expulsion from the Earth’s outer core has been suggested as one possible explanation for these peaks but has not yet been examined in detail. In this study, we develop a 2-D kinematic model for magnetic flux expulsion whose key control parameter is the magnetic Reynolds number Rm, the ratio of magnetic diffusion time to advection time. This model enables the tracking of magnetic field lines which are distorted and folded by a fixed flow pattern. Two processes govern the magnetic evolution of the system. The first is the expulsion of magnetic flux from closed streamlines, whereby flux gradually concentrates near the boundaries of the domain, which leads to an increase of the magnetic energy of the system. If the upper boundary separates the conducting fluid from an insulating medium, a second process then takes place, that of diffusion through this interface, which we can quantify by monitoring the evolution of the vertical component of magnetic induction along this boundary. It is the conjunction of these two processes that defines our model of magnetic flux expulsion through the core–mantle boundary. We analyse several configurations with varying flow patterns and magnetic boundary conditions. We first focus on flux expulsion from a single eddy. Since this specific configuration has been widely studied, we use it to benchmark our implementation against analytic solutions and previously published numerical results. We next turn our attention to a configuration which involves two counter-rotating eddies producing an upwelling at the centre of the domain, and comprises an upper boundary with an insulating medium. We find that the characteristic rise time and maximum instantaneous variation rate of the vertical component of the magnetic field that escapes the domain scale like $\sim R_m^{0.15}$ and $\sim R_m^{0.45}$, respectively. Extrapolation of these scaling laws to the Earth’s régime is compared with various purported archeointensity highs reported in the Near-East and in Western Europe. According to our numerical experiments magnetic flux expulsion is unlikely to produce geomagnetic spikes, while intensity peaks of longer duration (one century and more) and smaller variation rates appear to be compatible with this process.
Multiplicity and Concentration Results for a Magnetic Schrödinger Equation With Exponential Critical Growth in ℝ2
Authors: d’Avenia Pietro , Ji Chao
Published: March 2020

In this paper we study the following nonlinear Schrödinger equation with magnetic field $$\begin{align*} \left(\frac{\varepsilon}{i}\nabla-A(x)\right)^{2}u+V(x)u=f(| u|^{2})u,\quad x\in\mathbb{R}^{2}, \end{align*}$$where $\varepsilon>0$ is a parameter, $V:\mathbb{R}^{2}\rightarrow \mathbb{R}$ and $A: \mathbb{R}^{2}\rightarrow \mathbb{R}^{2}$ are continuous potentials, and $f:\mathbb{R}\rightarrow \mathbb{R}$ has exponential critical growth. Under a local assumption on the potential $V$, by variational methods, penalization technique, and Ljusternik–Schnirelmann theory, we prove multiplicity and concentration of solutions for $\varepsilon $ small.
Genotype-Specific Neutralization of Norovirus Is Mediated by Antibodies Against the Protruding Domain of the Major Capsid Protein
Authors: Ford-Siltz Lauren A , Wales Samantha , Tohma Kentaro , Gao Yamei , Parra Gabriel I
Published: March 2020

Human noroviruses are the most common viral agents of acute gastroenteritis. Recently, human intestinal enteroids were shown to be permissive for norovirus infection. We tested their suitability as a system to study norovirus neutralization. Hyperimmune sera raised against virus-like particles (VLPs) representing different genotypes showed highly specific neutralization activity against GII.4 and GII.6 noroviruses. Carbohydrate blocking assays and neutralization exhibited similar patterns in antibody responses. Notably, sera produced against chimeric VLPs that presented swapped structural shell and protruding (P) domains, from different genotypes showed that neutralization is primarily mediated by antibodies mapping to the P domain of the norovirus capsid protein. This study provides empirical information on the antigenic differences among genotypes as measured by neutralization, which could guide vaccine design.
Optimization of proppant parameters for CBM extraction using hydrofracturing by orthogonal experimental process
Authors: Li Haoze , Huang Bingxiang , Cheng Qingying , Zhao Xinglong
Published: March 2020

Proppant placement concentration, particle size and creep time are important factors that affect the embedment of proppant into coal. Based on multistage creep, an orthogonal test is conducted, and an optimal proppant scheme for different closure stresses obtained. The results show that with increased proppant placement concentration, the number of coal fractures increases and the elastic modulus of the fracture area decreases. As the proppant particle size decreases, the plasticity of fracture-proppant assemblies increases gradually. The yield limit is highest when the particle size is 20/40 mesh. During the proppant embedding process, localization or uneven distribution of proppant results in tensile stress parallel to the fracture surface, which induces tensile fracture in the coal. In the fracture-proppant assembly areas, proppant fractures are severe and yield lines appear. As proppant concentration increases, more energy is accumulated during the proppant compaction stage, resulting in energy release producing craters and crevasses. The energy released also causes increased stress in the proppant-coal contact area and fracturing to the coal mass. The longer the creep time, the weaker the impact and the smaller is fluctuation. Moreover, we find that the orthogonal test can effectively analyze the importance of each parameter. Proppant placement concentration was found to have the highest influence on the process of proppant embedding into coal, followed by particle size and then time. Under experimental conditions, the lowest proppant-embedded value in coal samples was observed with proppant placement concentration of 2 kg m−2 and particle size of 20/40 mesh.
Does Size Matter? Mate Choice in Two Lekking Flies
Authors: Tejeda Marco Tulio , Arredondo José , Díaz-Fleischer Francisco , Pérez-Staples Diana
Published: March 2020

For insect pests controlled through the Sterile Insect Technique (SIT), which consists in the mass production, sterilization, and release of target insects into affected areas, sterile male mating success with wild females is the key that will reduce population levels in the next generation. Male size is assumed to be important for mating success, but often without any concrete evidence or confounded by other parameters. Here, we evaluated male size and its interaction with male origin (laboratory or wild) on female choice for two lekking species controlled through SIT, Anastrepha obliqua (Macquart) and Anastrepha ludens (Loew) (Diptera: Tephritidae). In field cages, we tested wild females mating with: large wild males competing against small wild males; large wild males against small laboratory-sterile males; and large laboratory-sterile males against small wild males. We found evidence of large male advantage for A. obliqua but no effect of male size on mating competitiveness for A. ludens. For A. obliqua large wild males had a greater mating success over small laboratory males, yet large laboratory males secured a similar amount of copulations than small wild males. For A. ludens, there was no effect of male size on mating success. We discuss why A. obliqua is sensitive to size and origin while no effect was seen in A. ludens. SIT programs should not assume that male mating success is dependent on a large size. Alternatively, when an advantage exists for large males, mass-rearing programs should stride to produce and release large males.
Study of the solid electrolyte interphase of Li-O2 battery electrolyte by analytical transmission electron microscopy
Authors: Kitta Mitsunori , Sano Hikaru
Published: March 2020

Investigation of solid electrolyte interphases (SEIs) on negative electrode surfaces is essential to improve the stable charge-discharge performance of rechargeable lithium-air batteries (Li-O2 batteries). In this study, a direct investigation of SEI films is conducted using analytical transmission electron microscopy (TEM). A thin Cu specimen is prefabricated for TEM observation and is utilised as a model substrate for SEI formation. The electrochemical cell constructed using dissolved oxygen in the electrolyte exhibits a greater electrochemical overpotential during the Li-metal deposition process than that constructed with a pristine electrolyte. This suggests that different electrochemical passivation features occur in each different electrochemical cell. TEM observation confirms that the surface film formed by O2 dissolute electrolyte is a polycrystalline Li2O film with a thickness of ~5 nm, whereas the film formed by the pristine electrolyte is organic-based, amorphous-like and 20–50 nm thick. The dissolved oxygen molecules are more easily reduced than the components of the electrolyte, leading to the formation of Li2O as a stable passivation SEI film, which is expected to exhibit good charge-discharge features during the operation of the Li-O2 battery.
Harnessing Platform Envelopment in the Digital World
Authors: Condorelli Daniele , Padilla Jorge
Published: March 2020

We revisit the economics of “platform envelopment strategies,” whereby a dominant platform (the enveloper) operating in a multi-sided market (the origin market) enters a second multi-sided market (the target market) by leveraging the data obtained from its shared user relationships. In particular, we analyze the logic and effects of “privacy policy tying,” a strategy whereby the enveloper requests consumers to grant their consent to combining their data in both origin and target markets. This may allow the enveloper to fund the services offered to all sides of the target market by monetizing data in the origin market, monopolize the target market, and entrench its dominant position in the origin market. We conclude by considering a range of possible policy interventions that may serve to limit such potential anticompetitive effects, while preserving the efficiencies generated by conglomerate platforms.
The impact of a native hemiparasite on a major invasive shrub is affected by host size at time of infection
Authors: Cirocco Robert M , Facelli José M , Watling Jennifer R
Published: March 2020

Many studies have investigated the effect of parasitic plants on their hosts; however, few have examined how parasite impact is affected by host size. In a glasshouse experiment, we investigated the impact of the Australian native hemiparasitic vine, Cassytha pubescens, on a major invasive shrub, Ulex europaeus, of different sizes. Infected plants had significantly lower total, shoot, and root biomass, but the parasite’s impact was more severe on small than on large hosts. When infected, small but not large hosts had significantly lower nodule biomass. Irrespective of size, infection significantly decreased the host shoot/root ratio, pre-dawn and midday quantum yields, maximum electron transport rates, and carbon isotope composition, and the host nodule biomass per gram of root biomass significantly increased in response to infection. Infection did not affect host foliar nitrogen concentration or midday shoot water potential. Parasite biomass was significantly lower on small relative to large hosts, but was similar when expressed on a per gram of host total biomass basis. Parasite stem nitrogen, phosphorus, and potassium concentrations were significantly greater when C. pubescens was growing on small than on large hosts. Our results clearly show that C. pubescens strongly decreases performance of this major invasive shrub, especially when hosts are small. This suggests that C. pubescens could be used most effectively as a native biocontrol when deployed on smaller hosts.
The orbital clusters among the near-Earth asteroids
Authors: Jopek Tadeusz J
Published: March 2020

Fifteen orbital clusters (associations) were identified among ${\sim }20\, 000$ near-Earth asteroids (NEAs). All associations were found with a high statistical reliability using a single linkage cluster analysis algorithm and three orbital similarity functions. The identified groups constitute a small fraction (4.74 per cent) of the entire sample. Notwithstanding, they may be hazardous to Earth and its inhabitants. As with meteoroid streams, every year Earth comes very close to the orbits of each association. In two cases (2008TC3 and 2017FU102), the distance between the asteroid’s orbit and Earth’s orbit was shorter than Earth’s radius. Among the members of the identified associations, we found 331 objects larger than the Chelyabinsk asteroid and all of them approach Earth’s orbit at a distance smaller than 0.05 au. Two of the identified groups, (4179) Toutatis and (251430) Itokawa, support the hypothesis regarding the catastrophic origins of the asteroids Toutatis and Itokawa through violent collisions. This study does not focus on the origin of the NEA associations, but rather focuses on tracing the associations. Regardless of their origin, the identified groups pose a serious threat to Earth. Hence, to facilitate their monitoring of we calculated coordinates of the theoretical radiants and the calendar dates of their potential activity.
Merging game theory and control theory in the era of AI and autonomy
Authors: Cao Ming
Published: March 2020

Game theory and control theory, each powerful in its own right, can nourish each other in the focused area of intelligent and autonomous decision-making processes. In fact, the two theories enhancing each other is a must in response to the opportunity and need to design and implement AI and autonomy.
W.H. Hutt and the conceptualization of consumers’ sovereignty
Authors: Desmarais-Tremblay Maxime
Published: March 2020

This article examines the meaning of consumers’ sovereignty in the interwar thought of the economist William Harold Hutt. For Hutt, consumers’ sovereignty was an ideal, a norm against which economists could assess different economic systems. It connected the value of individual freedom, the commitment to a market society and an appeal to a liberal democracy. By coining the expression of consumers’ sovereignty, Hutt operated a creative re-description of the Millian idea of individual sovereignty which reflected the rise of the figure of the consumer in the public space. Hutt’s vision had been forged by the teaching he received at the London School of Economics and his involvement in the Individualist movement in the 1920s.
Septic Arthritis and the Opioid Epidemic: 1465 Cases of Culture-Positive Native Joint Septic Arthritis From 1990–2018
Authors: Ross John J , Ard Kevin L , Carlile Narath
Published: March 2020

Background

The clinical spectrum of septic arthritis in the era of the opioid crisis is ill-defined.

Methods

This is a retrospective chart review of 1465 cases of culture-positive native joint septic arthritis at Boston teaching hospitals between 1990 and 2018.

Results

Between 1990–2008 and 2009–2018, the proportion of septic arthritis cases involving people who inject drugs (PWID) rose from 10.3% to 20% (P < .0000005). Overall, methicillin-sensitive Staphylococcus aureus (MSSA) caused 41.5% of cases, and methicillin-resistant Staphylococcus aureus (MRSA) caused 17.9%. Gram-negative rods caused only 6.2% of cases. Predictors of MRSA septic arthritis included injection drug use (P < .001), bacteremia (P < .001), health care exposure (P < .001), and advancing age (P = .01). Infections with MSSA were more common in PWID (56.3% vs 38.8%; P < .00001), as were infections with MRSA (24% vs 16.8%; P = .01) and Serratia sp. (4% vs 0.4%; P = .002). Septic arthritis in the setting of injection drug use was significantly more likely to involve the sacroiliac, acromioclavicular, and facet joints; 36.8% of patients had initial synovial fluid cell counts of <50 000 cells/mm3.

Conclusions

Injection drug use has become the most common risk factor for septic arthritis in our patient population. Septic arthritis in PWID is more often caused by MRSA, MSSA, and Serratia sp., and is more prone to involve the sacroiliac, acromioclavicular, sternoclavicular, and facet joints. Synovial fluid cell counts of <50 000 cells/mm3 are common in culture-positive septic arthritis.
Does Intensive Treatment Select for Praziquantel Resistance in High-Transmission Settings? Parasitological Trends and Treatment Efficacy Within a Cluster-Randomized Trial
Authors: Tushabe John Vianney , Lubyayi Lawrence , Sserubanja Joel , Kabuubi Prossy , Abayo Elson , Kiwanuka Samuel , Nassuuna Jacent , Kaweesa James , Corstjens Paul , van Dam Govert , Sanya Richard E , Ssenyonga William , Tukahebwa Edridah Muheki , Kabatereine Narcis B , Elliott Alison M , Webb Emily L ,   LaVIISWA trial team, Sanya Richard , Nampijja Margaret , Mpairwe Harriet , Nerima Barbara , Serubanja Joel , Webb Emily , Lubyayi Lawrence , Akurut Hellen , Okello Justin , Owilla Sebastian , Ochola Jacob , Zziwa Christopher , Namutebi Milly , Nakazibwe Esther , Tumusiime Josephine , Ninsiima Caroline , Amongi Susan , Kamukama Grace , Iwala Susan , Asherwin Rita , Nampijja Rehema , Akello Florence , Akello Mirriam , Kizindo Robert , Sewankambo Moses , Nsubuga Denis , Cose Stephen , Nakawungu Prossy Kabuubi , Niwagaba Emmanuel , Oduru Gloria , Kabami Grace , Abayo Elson , Kakooza Fred Muwonge , Kabagenyi Joyce , Nkurunungi Gyaviira , Nalwoga Angela , Tushabe John Vianney , Nassuuna Jacent , Walusimbi Bridgious , Abiriga David , Walusimbi Richard , Kabonesa Cynthia , Kaweesa James , Tukahebwa Edridah , Kizza Moses , Elliott Alison
Published: March 2020

Background

Praziquantel mass drug administration (MDA) is recommended in schistosomiasis-endemic areas. Animal models demonstrate Schistosoma parasite resistance to praziquantel after repeated exposure.

Methods

We conducted a parasitological survey in 26 fishing communities in Uganda after 4 years of quarterly (13 communities) or annual (13 communities) praziquantel MDA, with Schistosoma infection detected by single-stool-sample Kato-Katz. A test of cure was done in participants who were positive on both urine circulating cathodic antigen test and 3-sample Kato-Katz. We calculated cure rates (CRs) and egg reduction rates (ERRs) based on 3-sample Kato-Katz and infection intensity using worm-specific circulating anodic antigen (CAA) in blood, comparing these between quarterly and annually treated participants.

Results

Single-sample Kato-Katz Schistosoma mansoni prevalence was 22% in 1,056 quarterly treated participants and 34% in 1,030 annually treated participants (risk ratio, 0.62; 95% confidence interval [CI], 0.40 to 0.94). Among 110 test-of-cure participants, CRs were 65% and 51% in annually and quarterly treated villages, respectively (odds ratio, 0.65; 95% CI, 0.27 to 1.58); ERRs were 94% and 81% (difference, –13%; 95% CI, –48% to 2%). There was no impact of quarterly vs annual praziquantel on S. mansoni by CAA.

Conclusions

In this schistosomiasis hot spot, there was little evidence of decreased praziquantel efficacy. However, in the absence of alternative therapies, there remains a need for continued vigilance of praziquantel efficacy in the MDA era.
sRIS: A Small RNA Illustration System for Plant Next-Generation Sequencing Data Analysis
Authors: Tseng Kuan-Chieh , Chiang-Hsieh Yi-Fan , Pai Hsuan , Wu Nai-Yun , Zheng Han-Qin , Chow Chi-Nga , Lee Tzong-Yi , Chang Song-Bin , Lin Na-Sheng , Chang Wen-Chi
Published: March 2020

Small RNA (sRNA), such as microRNA (miRNA) and short interfering RNA, are well-known to control gene expression based on degradation of target mRNA in plants. A considerable amount of research has applied next-generation sequencing (NGS) to reveal the regulatory pathways of plant sRNAs. Consequently, numerous bioinformatics tools have been developed for the purpose of analyzing sRNA NGS data. However, most methods focus on the study of sRNA expression profiles or novel miRNAs predictions. The analysis of sRNA target genes is usually not integrated into their pipelines. As a result, there is still no means available for identifying the interaction mechanisms between host and virus or the synergistic effects between two viruses. For the present study, a comprehensive system, called the Small RNA Illustration System (sRIS), has been developed. This system contains two main components. The first is for sRNA overview analysis and can be used not only to identify miRNA but also to investigate virus-derived small interfering RNA. The second component is for sRNA target prediction, and it employs both bioinformatics calculations and degradome sequencing data to enhance the accuracy of target prediction. In addition, this system has been designed so that figures and tables for the outputs of each analysis can be easily retrieved and accessed, making it easier for users to quickly identify and quantify their results. sRIS is available at http://sris.itps.ncku.edu.tw/.
What’s in a name? Perceptions and promotion of responsible research and innovation practices across Europe
Authors: Christensen Malene Vinther , Nieminen Mika , Altenhofer Marlene , Tancoigne Elise , Mejlgaard Niels , Griessler Erich , Filacek Adolf
Published: March 2020

After a decade of efforts to mainstream Responsible Research and Innovation (RRI) across Europe, the policy momentum is now uncertain. We explore how 217 organisations perceive responsibility in relation to their work, what mechanisms they apply to promote responsible practices, and what hindrances to promoting RRI they observe. Most organisations are unfamiliar with RRI but employ diverse perceptions of responsibility and mechanisms to promote it nonetheless. Civil society organisations are primarily outward oriented; collaborating with others and hosting science events. Private companies are more internally focussed and more likely to formalise this effort in strategies and internal guidelines. Universities resemble private companies, while private and public funders use funding-specific tools to incentivise responsible practices. Our results suggest that RRI is still poorly institutionalised and that some areas lack attention among actors in the research and innovation systems. Future policy endeavours might benefit from addressing deficits and tapping into existing perceptions of responsibility.
Changes in abscisic acid content during and after drought are related to carbohydrate mobilization and hydraulic recovery in poplar stems
Authors: Brunetti Cecilia , Savi Tadeja , Nardini Andrea , Loreto Francesco , Gori Antonella , Centritto Mauro
Published: March 2020

Drought compromises plant's ability to replace transpired water vapor with water absorbed from the soil, leading to extensive xylem dysfunction and causing plant desiccation and death. Short-term plant responses to drought rely on stomatal closure, and on the plant's ability to recover hydraulic functioning after drought relief. We hypothesize a key role for abscisic acid (ABA) not only in the control of stomatal aperture, but also in hydraulic recovery. Young plants of Populus nigra L. were used to investigate possible relationships among ABA, non-structural carbohydrates (NSC) and xylem hydraulic function under drought and after re-watering. In Populus nigra L. plants subjected to drought, water transport efficiency and hydraulic recovery after re-watering were monitored by measuring the percentage loss of hydraulic conductivity (PLC) and stem specific hydraulic conductivity (Kstem). In the same plants ABA and NSC were quantified in wood and bark. Drought severely reduced stomatal conductance (gL) and markedly increased the PLC. Leaf and stem water potential, and stem hydraulic efficiency fully recovered within 24 h after re-watering, but gL values remained low. After re-watering, we found significant correlations between changes in ABA content and hexoses concentration both in wood and bark. Our findings suggest a role for ABA in the regulation of stem carbohydrate metabolism and starch mobilization upon drought relief, possibly promoting the restoration of xylem transport capacity.
Mindfulness Meditation and Anxiety in Nursing Students
Authors: Stinson Cynthia , Curl Eileen Deges , Hale Gina , Knight Stacey , Pipkins Cynthia , Hall Iva , White Kelli , Thompson Nancy , Wright Christy
Published: March 2020

This quasi-experimental study used a convenience sample of nursing students (n = 49) to evaluate the effectiveness of mindfulness meditation on anxiety. Students participated in mindfulness meditation sessions and completed the State-Trait Anxiety Inventory. A statistically significant reduction in trait anxiety was found in the intervention group (p = .000); state anxiety decreased but not significantly. In contrast, anxiety increased significantly in the comparison group, but progression was not significantly different between groups. Trait anxiety may decrease with mindfulness meditation.
Prospective Implementation and Evaluation of a Decision-Tree Algorithm for Route of Hysterectomy
Authors: Schmitt Jennifer J. , Baker Mary V. , Occhino John A. , McGree Michaela E. , Weaver Amy L. , Bakkum-Gamez Jamie N. , Dowdy Sean C. , Pasupathy Kalyan S. , Gebhart John B.
Published: March 2020

OBJECTIVE:

To evaluate the rate of vaginal hysterectomy and outcomes after initiation of a prospective decision-tree algorithm to determine the optimal surgical route of hysterectomy.

METHODS:

A prospective algorithm to determine optimal route of hysterectomy was developed, which uses the following factors: history of laparotomy, uterine size, and vaginal access. The algorithm was implemented at our institution from November 24, 2015, to December 31, 2017, for patients requiring hysterectomy for benign indications. Expected route of hysterectomy was assigned by the algorithm and was compared with the actual route performed to identify compliance compared with deviation. Surgical outcomes were analyzed.

RESULTS:

Of 365 patients who met inclusion criteria, 202 (55.3%) were expected to have a total vaginal hysterectomy, 57 (15.6%) were expected to have an examination under anesthesia followed by total vaginal hysterectomy, 52 (14.2%) were expected to have an examination under anesthesia followed by robotic-assisted total laparoscopic hysterectomy, and 54 (14.8%) were expected to have an abdominal or robotic–laparoscopic route of hysterectomy. Forty-six procedures (12.6%) deviated from the algorithm to a more invasive route (44 robotic, two abdominal). Seven patients had total vaginal hysterectomy when robotic-assisted total laparoscopic hysterectomy or abdominal hysterectomy was expected by the algorithm. Overall, 71% of patients were expected to have a vaginal route of hysterectomy per the algorithm, of whom 81.5% had a total vaginal hysterectomy performed; more than 99% of the total vaginal hysterectomies attempted were successfully completed.

CONCLUSION:

Vaginal surgery is feasible, carries a low complication rate with excellent outcomes, and should have a place in gynecologic surgery. National use of this prospective algorithm may increase the rate of total vaginal hysterectomy and decrease health care costs.
Racial and Ethnic Disparities in Perinatal Insurance Coverage
Authors: Daw Jamie R. , Kolenic Giselle E. , Dalton Vanessa K. , Zivin Kara , Winkelman Tyler , Kozhimannil Katy B. , Admon Lindsay K.
Published: March 2020

OBJECTIVE:

To measure the association between race–ethnicity and insurance status at preconception, delivery, and postpartum and the frequency of insurance gaps and transitions (disruptions) across these time points.

METHODS:

We conducted a cross-sectional analysis of survey data from 107,921 women in 40 states participating in the Centers for Disease Control and Prevention's Pregnancy Risk Assessment and Monitoring System from 2015 to 2017. We calculated unadjusted estimates of insurance status at preconception, delivery, and postpartum and continuity across these time points for seven racial–ethnic categories (white non-Hispanic, black non-Hispanic, indigenous, Asian or Pacific Islander, Hispanic Spanish-speaking, Hispanic English-speaking, and mixed race or other). We also examined unadjusted estimates of uninsurance at each perinatal time period by state of residence. We calculated adjusted differences in the predicted probability of uninsurance at preconception, delivery, and postpartum using logistic regression models with interaction terms for race–ethnicity and income.

RESULTS:

For each perinatal time point, all categories of racial–ethnic minority women experienced higher rates of uninsurance than white non-Hispanic women. From preconception to postpartum, 75.3% (95% CI 74.7–75.8) of white non-Hispanic women had continuous insurance compared with 55.4% of black non-Hispanic women (95% CI 54.2–56.6), 49.9% of indigenous women (95% CI 46.8–53.0) and 20.5% of Hispanic Spanish-speaking women (95% CI 18.9–22.2). In adjusted models, lower-income Hispanic women and indigenous women had a significantly higher predicted probability of uninsurance in the preconception and postpartum period compared with white non-Hispanic women.

CONCLUSION:

Disruptions in perinatal insurance coverage disproportionately affect indigenous, Hispanic, and black non-Hispanic women. Differential insurance coverage may have important implications for racial–ethnic disparities in access to perinatal care and maternal–infant health.
Prenatal Diagnosis of a Furcate Placenta
Authors: Cohen Bruce , Wilson Monika , Cohen Austin , Yum Mimi
Published: March 2020

BACKGROUND:

A furcate placental cord insertion is rare and potentially dangerous. Prenatal diagnosis of this finding has been reported on only two prior occasions.

CASE:

We present the case of a 33-year-old patient who, at 35 weeks of gestation, was suspected on ultrasonography to have a cord insertion that was both furcate and velamentous. Because of this finding, the patient underwent labor induction at 37 weeks of gestation and delivered a vigorous neonate vaginally. Pathologic evaluation confirmed furcate placenta.

CONCLUSION:

The identification of a furcate placenta, a potentially lethal umbilical cord insertion site abnormality, is possible prenatally. Future research should elucidate the prevalence of furcate cord insertions as well as whether they impose increased fetal risk.
Plasma Concentrations of Tranexamic Acid in Postpartum Women After Oral Administration
Authors: Muhunthan Kopalasuntharam , Balakumar Sandrasegarampillai , Navaratnaraja Thiyahini S. , Premakrishna Sundaralingam , Arulkumaran Sabaratnam
Published: March 2020

OBJECTIVE:

To evaluate the pharmacokinetics of tranexamic acid after oral administration to postpartum women.

METHODS:

We conducted a single-center pharmacokinetic study at Teaching Hospital—Jaffna, Sri Lanka, on 12 healthy postpartum women who delivered vaginally. After oral administration of 2 g of immediate-release tranexamic acid 1 hour after delivery, pharmacokinetic parameters were measured on plasma samples at 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 10, and 12 hours. Plasma tranexamic acid concentrations were determined by high-performance liquid chromatography. The outcome measures were maximum observed plasma concentration, time to maximum plasma concentration, time to reach effective plasma concentration, time period effective serum concentration lasted, area under the curve for drug concentration, and half-life of tranexamic acid.

RESULTS:

The mean maximum observed plasma concentration was 10.06 micrograms/mL (range 8.56–12.22 micrograms/mL). The mean time to maximum plasma concentration was 2.92 hours (range 2.5–3.5 hours). Mean time taken to reach the effective plasma concentration of 5 micrograms/mL and the mean time this concentration lasted were 0.87 hours and 6.73 hours, respectively. Duration for which plasma tranexamic acid concentration remained greater than 5 micrograms/mL was 5.86 hours. Half-life was 1.65 hours. Area under the curve for drug concentration was 49.16 micrograms.h/mL (range 43.75–52.69 micrograms.h/mL).

CONCLUSION:

Clinically effective plasma concentrations of tranexamic acid in postpartum women may be achieved within 1 hour of oral administration. Given the promising pharmacokinetic properties, we recommend additional studies with larger sample sizes to investigate the potential of oral tranexamic acid for the treatment or prophylaxis of postpartum hemorrhage.
Antenatal Diagnosis of Marginal and Velamentous Placental Cord Insertion and Pregnancy Outcomes
Authors: O'Quinn Candace , Cooper Stephanie , Tang Selphee , Wood Stephen
Published: March 2020

OBJECTIVE:

To evaluate the association between antenatal diagnosis of velamentous and marginal placental cord insertions with adverse perinatal outcomes of small-for-gestational-age (SGA) birth weight (less than the 5th percentile), caesarean birth, and perinatal mortality.

METHODS:

Using a diagnostic imaging database, we performed a cohort study of all consecutive singleton pregnancies (35,391), including 1,427 cases of marginal and 107 cases of velamentous cord insertion, delivered after 24 6/7 weeks of gestation between January 1, 2012, and December 31, 2015, at a single Canadian tertiary care center. Cases with placenta previa, vasa previa, no documented cord insertion, or fetal anomalies were excluded.

RESULTS:

In the overall cohort, the rate of birth weight less than the 5th percentile was 5.2%, the rate of cesarean delivery was 27.1%, and the rate of perinatal mortality was 0.24%. Velamentous cord insertion was associated with SGA (relative risk [RR] 2.19, 95% CI 1.28–3.74). This persisted after controlling for smoking during pregnancy, diabetes, and hypertension (adjusted odds ratio [aOR] 1.98, 95% CI 1.03–3.84). Velamentous cord insertion was also associated with an increased risk of caesarean birth (RR=1.38, 95% CI=1.08–1,77) and perinatal death (1.87%, RR 8.15, 95% CI 2.02–32.8), a relationship that persisted after controlling for smoking during pregnancy, diabetes, and hypertension (aOR 1.53, 95% CI 1.01–2.32). Marginal cord insertion was not associated with birth weight less than the 5th percentile (RR 1.23, 95% CI 1.00–1.51), cesarean delivery (RR 1.01, 95% CI 0.92–1.10), or perinatal death (RR 1.53, 95% CI 0.62–3.78).

CONCLUSION:

Antenatal diagnosis of velamentous placental cord insertion is associated with birth weight less than the 5th percentile.
Patterns of Screening, Infection, and Treatment of Chlamydia trachomatis and Neisseria gonorrhea in Pregnancy
Authors: Goggins Emily R. , Chamberlain Allison T. , Kim Tesia G. , Young Marisa R. , Jamieson Denise J. , Haddad Lisa B.
Published: March 2020

OBJECTIVE:

To describe factors associated with not being tested for Chlamydia trachomatis and Neisseria gonorrhea infection during pregnancy and for testing positive and to describe patterns of treatment and tests of reinfection.

METHODS:

We conducted a retrospective cohort study of women who delivered at an urban teaching hospital from July 1, 2016 to June 30, 2018. Women with at least one prenatal care or triage visit were included. The index delivery was included for women with multiple deliveries. We used logistic regression to analyze factors associated with not being tested and for testing positive for these infections in pregnancy. Cox proportional hazards models were used to examine factors associated with time to treatment and tests of reinfection. We reviewed medical records to determine reasons for delays in treatment longer than 1 week.

RESULTS:

Among 3,265 eligible deliveries, 3,177 (97%) women were tested during pregnancy. Of these, 370 (12%) tested positive (287 chlamydia, 35 gonorrhea, 48 both), and 15% had repeat infections. Prenatal care adequacy and insurance status were risk factors for not being tested. Age, race and ethnicity, alcohol use, and sexually transmitted infection history were associated with testing positive. Time to treatment ranged from 0 to 221 days, with the majority (55%) of patients experiencing delays of more than 1 week. Common reasons for delays included lack of clinician recognition and follow-up of abnormal results (65%) and difficulty contacting the patient (33%).

CONCLUSION:

Traditional risk factors are associated with increased risk of infection during pregnancy. Prenatal care adequacy and insurance status were associated with the likelihood of being tested. Delays in treatment and tests of reinfection were common. Point-of-care testing and expedited partner therapy should be explored as ways to improve the management of these infections in pregnancy.
Trends in cup position utilizing computer-assisted navigation during total hip arthroplasty: A retrospective observational study
Authors: Mays Rachel R. , Benson Jessica R. , Muir Jeffrey M. , Meftah Morteza
Published: March 2020

Background:

Proper positioning of the acetabular cup deters dislocation after total hip arthroplasty (THA) and is therefore a key focus for orthopaedic surgeons. The concept of a safe zone for acetabular component placement remains widely utilized in contemporary THA practice; however, components positioned in this safe zone still dislocate. The purpose of this study was to characterize trends in acetabular cup positioning and to determine if the surgical approaches used affected the rate at which the components were placed in the safe zones.

Methods:

This retrospective, observational study reviewed acetabular cup position in 1236 patients who underwent THA using computer-assisted navigation. Outcomes included acetabular cup position measurements derived from a surgical navigation device and surgical approach.

Results:

The overall mean cup position of all recorded cases was 21.8 degrees (±7.7 degrees, 95% CI=6.7 degrees, 36.9 degrees) of anteversion and 40.9 degrees (±6.5 degrees, 95% CI=28.1 degrees, 53.7 degrees) of inclination. For anteversion and inclination, 65.5% (809/1236) of acetabular cup components were within the Lewinnek safe zone, and 58.4% (722/1236) were within the Callanan safe zone. Acetabular cups were placed at a mean of 6.8 degrees of anteversion (posterior/lateral approach: 7.0 degrees, anterior approach: 5.6 degrees) higher than the Lewinnek and Callanan safe zones, whereas inclination was positioned 0.9 degrees higher than the reported Lewinnek safe zone and 3.4 degrees higher than the Callanan safe zone.

Conclusions:

Our data show that while most acetabular cups were placed within the traditional safe zones, the mean anteversion orientation is considerably higher than those suggested by the Lewinnek and Callanan safe zones. The implications of this observation warrant further investigation.

Level of Evidence:

Level III.
Student Nurses' Digital Literacy Levels
Authors: Brown Janie , Morgan Alani , Mason Jaci , Pope Nicole , Bosco Anna Maria
Published: March 2020

The rapid uptake of technology is changing the way health professionals provide care to patients and communities. While this presents opportunities to improve, enhance, and positively transform care and treatment, graduates must have the requisite knowledge, skills, and attitudes to make effective use of the technology and data available to them. This research explored nursing students' self-reported digital literacy levels. We undertook a student survey at one university in Australia, utilizing the validated Self-Assessment Nursing Informatics Competencies Scale–SF30 instrument. Overall, 90% of students rated their basic computer knowledge and skills as at least “competent” including performing basic troubleshooting, using the Internet, and conducting online literature searches. However, only 55% of students considered their overall applied computer skills as at least “competent,” which included using applications for diagnostic coding and to extract data from clinical data sets. Students have digital literacy in everyday settings; however, their ability to translate this into practice is limited, restricting their access to and use of digital tools in the workplace. Our findings provide the opportunity to address practice issues related to digital literacy and to embed appropriate content in curricula to enable the delivery of improved patient care and the appropriate use of data in various settings.
The antinociceptive effects of a dual kappa-delta opioid receptor agonist in the mouse formalin test
Authors: Ulker Esad , Toma Wisam , White Alyssa , Uprety Rajendra , Majumdar Susruta , Damaj M. Imad
Published: March 2020

Pain management is a challenging and unmet medical need. Despite their demonstrated efficacy, currently used opioid drugs and nonsteroidal anti-inflammatory drugs are frequently associated with several adverse events. The identification of new and safe analgesics is therefore needed. MP1104, an analogue of 3′−iodobenzoyl naltrexamine, is a potent nonselective full agonist at mu (MOR), kappa (KOR), and delta (DOR) opioid receptors, respectively. It was shown to possess potent antinociceptive effects in acute thermal pain assays without aversion in mice. In this study, we investigated MP1104 in the formalin test, a model of tonic pain. MP1104 (0.05, 0.1, and 1.0 mg/kg) reduced pain-like behaviors in phases I and II of the formalin test in male and female ICR mice. Pretreatment with KOR antagonist (norbinaltorphimine 10 mg/kg) and DOR antagonist (naltrindole 10 mg/kg) abolished the antinociceptive effects of MP1104 in the formalin test. These findings support the development of MP1104 for further testing in other pain models.
Adnexal Masses in Pregnancy
Authors: MCMINN ERIN , SCHWARTZ NADAV
Published: March 2020

With the increased use and quality of ultrasound in pregnancy, adnexal masses are being encountered with greater frequency. Fortunately, the vast majority of such masses are benign and resolve on their own. However, it is important for clinicians to be familiar with the types of adnexal masses that may be visualized in pregnancy to best counsel these women. In addition, complications such as ovarian torsion, and rarely, even malignancy can occur. In this article, we review the available literature on this subject to help guide the clinician in the diagnosis and management of adnexal masses in pregnancy.
Estimation of the Effective Dose of Radiation Workers: Optimization Based on the Weight Percentile
Authors: Shahri Keyhandokht Karimi
Published: March 2020

Radiation workers might be exposed to polyenergetic photon radiation beams at different directions in their working environments. In this regard, their effective dose (E) should be accurately estimated using a two-dosimeter algorithm (TDA), based on the measurements of two thermoluminescent dosimeters (TLDs) or film badges that are mounted on the front and back of the body. However, considering different human anatomies, radiation workers may have a variety of weight percentiles. This work sought to find whether TDA obtained for the reference weight percentile (50th) can be used for higher weight percentiles (including; 65th, 75th, 85th, and 95th). MCNPX was used to simulate different weight percentiles on the revised ORNL phantom by adding extra layers of muscle and adipose on the torso. Then front and back TLD responses were calculated for external beam photon energies of 40 keV to 10 MeV in different irradiation geometries. The results revealed that E value declines with increasing the weight percentile. In this study, three TDA were investigated consisting of Eest = 0.73 Rf + 0.53 Rb (73/53), Eest = 0.55 Rf + 0.50 Rb (55/50), and Eest = 0.70 Rf + 0.30 Rb (70/30). The ratio of Eest/E was calculated for each TDA in different energy bins and weight percentiles. Results obtained using the 55/50 and 70/30 showed higher underestimation for most of the energy bins, especially for PA and AP geometries. Compared to these two TDA, the 73/53 algorithm resulted in higher overestimation for RLAT and LLAT geometries for the same energy bins. Variation of the algorithms showed a similar trend for the studied weight percentiles. To conclude, results obtained by TDA for the 50% weight percentile are applicable for weight percentiles >50%.
Amount of Brain Edema Correlates With Neurologic Recovery in Pediatric Cerebral Malaria
Authors: Kampondeni Samuel , Seydel Karl B. , Zhang Bo , Small Dylan S. , Birbeck Gretchen L. , Hammond Collen A. , Chilingulo Cowles , Taylor Terrie E. , Potchen Michael J.
Published: March 2020

Background:

Cerebral malaria (CM) remains a leading cause of mortality and morbidity in children in sub-Saharan Africa. Recent studies using brain magnetic resonance imaging have revealed increased brain volume as a major predictor of death. Similar morphometric predictors of morbidity at discharge are lacking. The aim of this study was to investigate the utility of serial cranial cisternal cerebrospinal fluid (CSF) volume measurements in predicting morbidity at discharge in pediatric CM survivors.

Methods:

In this case–control study, 54 Malawian pediatric CM survivors with neurologic sequelae evident at discharge who underwent serial magnetic resonance imaging scans while comatose were matched to concurrently admitted children with serial imaging who made full recoveries. Serial cranial cisternal CSF volume quantified by radiologists blinded to outcome was evaluated as a predictor of neurologic deficits at discharge. The probability of neurologic sequelae was determined using a model that included coma duration and changes in cisternal CSF volume over time.

Results:

Coma duration before admission was similar between cases and controls (16.1 vs. 15.3; P = 0.81), but overall coma was longer among children with sequelae (60 vs. 38 hours; P < 0.01). Lower initial CSF volumes and decreased volumes over time were both associated with a higher probability of neurologic sequelae at discharge.

Conclusions:

Among pediatric CM survivors with prolonged coma, lower initial CSF volume and decreasing volume during coma is associated with neurologic sequelae at discharge. These findings suggest that cerebral edema is an underlying contributor to both morbidity and mortality in pediatric CM.
Intestinal Spirochetes in Cancer Patients
Authors: Cheema Asima , Jejelowo Oluwafisayo , Syed Misbahuddin , Ramsakal Asha , Greene John N.
Published: March 2020

The clinical significance of human intestinal spirochetosis is a debated topic, with possible links to various gastrointestinal symptoms such as diarrhea and hematochezia. The most commonly associated organisms in humans involve Brachyspira aalborgi and Brachyspira pilosicoli. However, the presence of spirochetes within the colorectal epithelium does not always suggest pathogenicity, and treatment does not always lead to symptom improvement. Men who have sex with men and patients infected with the HIV have been considered at higher risk of colonization and subsequently becoming symptomatic, possibly related to an underlying immunosuppressed state. We present a series of 3 case reports of human intestinal spirochetosis in immunocompromised cancer patients at the Moffitt Cancer Center and Research Institute. The aim of this study is to increase awareness of this entity in immunocompromised cancer patients and non–HIV-positive immunosuppressed patients, particularly when presenting with gastrointestinal symptoms of unclear etiology.