bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics of whole blood donors in a hospital‐based blood bank in Nigeria: a one‐year review
Authors: Fasola Foluke Atinuke , Olaniyi John Ayodele , Irabor Achiaka , Alonge Temitope , Amaunam Stella
Published: May 2019

Background and Objectives

In order to meet the WHO standard set for blood transfusion needs in any country per year and to improve the extremely low average annual blood donation rate in Nigeria, a clear understanding of the characteristics of blood donors is fundamental, hence this study.

Materials and Method

The study was a prospective descriptive analysis of data on prospective whole blood donors prior to blood donation in the blood bank of a tertiary hospital. Data were obtained from the 2017 annual report of the Total Quality Management Department of the hospital. The blood donor characteristics available were age, sex, marital status, number of previous donations and eligibility status.

Result

There were 7527 whole blood donors, of which 2022 were return blood donors with an average of one donation per year and 3·2 previous donations. Family replacement donors constituted 83% while voluntary donors accounted for 16·6%. The mean age of the donors was 33·7 ± 9·0 years (age ranged 16–68 years). The highest donors (37%) belong to the age group 25 to 34 years while the age group <25 years constituted 18·7%. The age group <25 years had one of the highest eligibility rates, and being single was significantly associated with eligibility to donate.

Conclusion

The blood donors aged <25 years with one of the highest eligibility rates were under‐represented and should be targeted by donor organizers, as they are candidate for long donor career. Suggestions were made on how to motivate replacement donors to become voluntary donors.
A prospective, randomized, controlled clinical trial on the efficacy of a single‐use negative pressure wound therapy system, compared to traditional negative pressure wound therapy in the treatment of chronic ulcers of the lower extremities
Authors: Kirsner Robert , Dove Cyaandi , Reyzelman Alex , Vayser Dean , Jaimes Henry
Published: May 2019

Multicenter, phase‐4, randomized, comparative‐efficacy study in patients with VLUs or DFUs comparing for noninferiority the percentage change in target ulcer dimensions (area, depth, and volume) a single‐use negative pressure wound therapy (s‐NPWT) system versus traditional NPWT (t‐NPWT) over a 12‐week treatment period or up to confirmed healing. Baseline values were taken at the randomization visit. Randomized by wound type and size, 164 patients with non‐infected DFUs and VLUs were included. The ITT population was composed of 161 patients (101 with VLUs, 60 with DFUs) and 115 patients completed follow‐up (64 in the s‐NPWT group and 51 in the t‐NPWT group) (PP population). The average age for all patients was 61.5 years, 36.6% were women, and treatment groups were statistically similar at baseline. Primary endpoint analyses on wound area reduction demonstrated statistically significant reduction in favor of s‐NPWT (p = 0.003) for the PP population and for the ITT population (p < 0.001). Changes in wound depth (p = 0.018) and volume (p = 0.013) were also better with s‐NPWT. Faster wound closure was observed with s‐NPWT (Cox Proportional Hazards ratio (0.493 (0.273, 0.891); p = 0.019) in the ITT population. Wound closure occurred in 45% of patients in the s‐NPWT group vs. 22.2% of patients in the t‐NPWT group (p = 0.002). Median estimate of the time to wound closure was 77 days for s‐NPWT. No estimate could be provided for t‐NPWT due to the low number of patients achieving wound closure. Device‐related AEs were more frequent in the t‐NPWT group (41 AEs from 29 patients) than in the s‐NPWT group (16 AEs from 12 patients). The s‐NPWT system met noninferiority and achieved statistical superiority vs. t‐NPWT in terms of wound progression toward healing over the treatment period. When NPWT is being considered for the management of challenging VLUs and DFUs, s‐NPWT should be considered a first choice over other types of NPWT.
Constraints on the cohomological correspondence associated to a self map
Authors: Shuddhodan K. V.
Published: May 2019

In this paper we establish some constraints on the eigenvalues for the action of a self map of a proper variety on its$\ell$-adic cohomology. The essential ingredients are a trace formula due to Fujiwara, and the theory of weights.
An effective Chabauty–Kim theorem
Authors: Balakrishnan Jennifer S. , Dogra Netan
Published: May 2019

The Chabauty–Kim method allows one to find rational points on curves under certain technical conditions, generalising Chabauty’s proof of the Mordell conjecture for curves with Mordell–Weil rank less than their genus. We show how the Chabauty–Kim method, when these technical conditions are satisfied in depth 2, may be applied to bound the number of rational points on a curve of higher rank. This provides a non-abelian generalisation of Coleman’s effective Chabauty theorem.
Asthma self-management in children: a best practice implementation project
Authors: He Yingxia , Stephenson Matthew , Gu Ying , Hu Xiaojing , Zhang Mingzhi , Jin Jie
Published: May 2019

Introduction:

Asthma is one of the most common diseases in children. A self-management program can effectively improve the outcomes for children with asthma and reduce the burden on healthcare services.

Objectives:

The aim of this project was to integrate the best evidence on asthma self-management with practice in a children's respiratory clinic and to improve compliance with best practice.

Methods:

Seven audit criteria were developed for the pre- and post-audit based on the best available evidence. The Joanna Briggs Institute (JBI) Practical Application of Clinical Evidence System and Getting Research into Practice audit and feedback tools were used in this project.

Results:

The baseline audit showed a gap between clinical practice and the best evidence. The only criterion that achieved high compliance was provision of inhaler guidance (100%). After implementation, there were substantial improvements in compliance for many criteria. Training of clinicians increased from 13% at baseline to 67% at follow-up. Education of parents improved, with specific education about asthma triggers increasing from 55% to 100%, education about warning signs from 30% to 85% and education about effective asthma treatment options from 40% to 85%. Use of written asthma action plans increased from 0% to 25%.

Conclusion:

Strategies developed in this project were effective at providing necessary information for parents and improved the compliance with evidence. Further implementation strategies and audits are still needed to improve the use of asthma action plans and ensure they are reviewed periodically.
Youths with asthma and their experiences of self-management education: a qualitative systematic review protocol
Authors: McTague Karen , Prizeman Geraldine , Shelley Stephen , Eustace-Cook Jessica , McCann Edward
Published: May 2019

Review question:

What are the experiences of youths with asthma in self-management education?
Clinical nursing handovers for continuity of safe patient care in adult surgical wards: a best practice implementation project
Authors: Wong Xiaoling , Tung Yi Jung , Peck Sin Yee , Goh Mien Li
Published: May 2019

Objectives:

The objective of this evidence-based quality improvement project was to improve clinical nursing handovers between registered nurses.

Introduction:

Clinical nursing handovers transfer critical information about the patient's care to oncoming shift nurses. Nurses use structured handover tools to handover patient information. In three adult surgical wards of a Singapore tertiary hospital, a lack of consistency was found in the local handover process when shifts changed. These resulted in ineffective handovers and compromised the patient's safety. Thus, evidence-based interventions were needed so that patient handovers and continuity in safe patient care could improve.

Methods:

This project was implemented in three phases from January 2017 to November 2017 at three adult surgical wards of a tertiary hospital, utilizing the Joanna Briggs Institute Practical Application of Clinical Evidence System (JBI PACES) and Getting Research into Practice (GRiP) module. The pre- and post-implementation audits were conducted using JBI PACES audit criteria. An evidence-based four-pronged approach was employed, including adequate human resource coverage during handovers, a structured and standardized handover, visual cues and a teaching video.

Results:

The results of the post-implementation audit of nurses performing handovers (n = 33) showed that handovers using standardized documentation improved from 0% to 21.0% (p = 0.005), which was statistically significant. However, handovers of detailed observations of patients improved from 72.7% to 87.9% (p = 0.215) and handovers of relevant history of patients improved slightly from 93.9% to 97.0% (p = 1.000) but was not statistically significant. Medication error incidents related to handovers was reduced by 72% over a six-month period.

Conclusion:

The multi-modal approach improved the comprehensiveness and completeness of clinical nursing handovers. These strategies had a significant effect on reducing medication errors related to handovers.
Shift of leading pacemaker site during reflex vagal stimulation and altered electrical source‐to‐sink balance
Authors: Ashton Jesse L. , Trew Mark L. , LeGrice Ian J. , Paterson David J. , Paton Julian FR. , Gillis Anne M. , Smaill Bruce H.
Published: May 2019

Key points

Vagal reflexes slow heart rate and can change where the heartbeat originates within the sinoatrial node (SAN). The mechanisms responsible for this process – termed leading pacemaker (LP) shift – have not been investigated fully.

We used optical mapping to measure the effects of baroreflex, chemoreflex and carbachol on pacemaker entrainment and electrical conduction across the SAN.

All methods of stimulation triggered shifts in LP site from the central SAN to one or two caudal pacemaker regions. These shifts were associated with reduced current generation capacity centrally and increased electrical load caudally.

Previous studies suggest LP shift is a rate‐dependent phenomenon whereby acetylcholine slows central pacemaker rate disproportionately, enabling caudal cells that are less acetylcholine sensitive to assume control. However, our findings indicate the LP region is defined by both pacemaker rate and capacity to drive activation.

Shifts in LP site provide an important homeostatic mechanism for rapid switches in heart rate.

Reflex vagal activity causes abrupt heart rate slowing with concomitant caudal shifts of the leading pacemaker (LP) site within the sinoatrial node (SAN). However, neither the mechanisms responsible nor their dynamics have been investigated fully. Therefore, the objective of this study was to elucidate the mechanisms driving cholinergic LP shift. Optical maps of right atrial activation were acquired in a rat working heart–brainstem preparation during baroreflex and chemoreflex stimulation or with carbachol. All methods of stimulation triggered shifts in LP site from the central SAN to caudal pacemaker regions, which were positive for HCN4 and received uniform cholinergic innervation. During baroreflex onset, the capacity of the central region to drive activation declined with a decrease in amplitude and gradient of optical action potentials (OAPs) in the surrounding myocardium. Accompanying this decline, there was altered entrainment in the caudal SAN as shown by decreased conduction velocity, OAP amplitude, gradient and activation time. Atropine abolished these responses. Chemoreflex stimulation produced similar effects but central capacity to drive activation was preserved before the LP shift. In contrast, carbachol produced a prolonged period of reduced capacity to drive and altered entrainment. Previous studies suggest LP shift is a rate‐dependent phenomenon whereby acetylcholine slows central pacemaker rate disproportionately, enabling caudal cells that are less acetylcholine sensitive to assume control. Our findings indicate that cholinergic LP shifts are also determined by altered electrical source‐to‐sink balance in the SAN. We conclude that the LP region is defined by both rate and capacity to drive atrial activation.
The State of American Manufacturing 2019
Authors: Brown Alan S.
Published: May 2019

U.S. manufacturers had a great 2018, but concerns continue to accompany every positive trend. There were some bright spots as well as concerns - both count because manufacturing still matters. It accounts for 70 percent of U.S. private sector R&D, 55 percent of its patents, and 60 percent of its exports. And it employs 30 percent of its engineers. How manufacturers resolve those issues will make a difference. This study examines them in greater depth.
Combined Pinch and Exergy Evaluation for Fault Analysis in a Steam Power Plant Heat Exchanger Network
Authors: Njoku Howard O. , Egbuhuzor Linus C. , Eke Mkpamdi N. , Enibe Samuel O. , Akinlabi Esther A.
Published: May 2019

This study demonstrates comparative applications of the standard pinch and exergy analysis and the combined pinch-exergy analysis methodologies to a gas-fired steam power plant’s heat exchanger network. The extent to which each methodology could be used for pin-pointing the location of performance deteriorations in the network and their relative criticality were shown. Using a 12 °C minimum temperature difference, the network minimum hot utility requirement in current operation was determined by a pinch analysis as 539,491 kW, at a supply temperature of 549 °C. This represented a 6% (30,618 kW) increase in the utility requirement when compared with the design minimum requirement (508,873.7 kW). The combined exergy pinch analysis showed the severity of performance deteriorations more clearly, determining a 25% increase in global plant exergy losses with respect to design conditions. With a standard exergy analysis, additional information on the actual network components responsible for the changes was obtained—there were general declines in component performances except for two heaters and the deaerator, whose operation performances improved slightly. Furthermore, avoidable and inevitable exergy losses (Ξ˙d,AVO and Ξ˙d,INE, respectively) were determined for network components. Whereas both were highest for the boiler, the values of the ratio Ξ˙d,AVO/Ξ˙d,INE showed that higher potentials for performance improvement existed in the other network components. This indicates the ratio Ξ˙d,AVO/Ξ˙d,INE as an appropriate measure for deciding equipment in the heat exchanger network that are in need critical attention.
Estimation-Based Maximum Power Point Tracking in a Self-Balancing Photovoltaic Battery Energy Storage System
Authors: Mishra Partha P. , Denlinger Michelle , Fathy Hosam K.
Published: May 2019

This paper examines the problem of controlling the exchange of current in photovoltaic-plus-storage systems to achieve photovoltaic (PV) maximum power point tracking (MPPT). This work is motivated by the need for MPPT algorithms that are less costly and complex to implement in PV farms with integrated battery energy storage. We study the online optimal control of a “hybrid” PV/lithium (Li)-ion battery integration topology that is self-balancing in nature. The self-balancing behavior ensures that the state of charge (SOC) across different cells balances to the same stable equilibrium value without needing any balancing power electronics, thereby significantly reducing the integration cost. The DC–DC converters in this hybrid system are controlled to achieve PV MPPT that maximizes energy generation and storage. However, sensing needs for traditional MPPT controllers can render the hybrid system unnecessarily complex and costly. We surmount this problem by: (i) developing a novel model-based PV power estimation algorithm that only requires voltage measurement, and (ii) using this algorithm together with extremum-seeking (ES) control to achieve closed-loop, estimation-based PV MPPT. Simulation case studies show that this estimation-based MPPT controller is able to harness more than 99% of the maximum available solar energy under different irradiation profiles.
Contributions of Tip Leakage and Inlet Diffusion on Inducer Backflow
Authors: Fanning D. Tate , Gorrell Steven E. , Maynes Daniel , Oliphant Kerry
Published: May 2019

Inducers are used as a first stage in pumps to minimize cavitation and allow the pump to operate at lower inlet head conditions. Inlet flow recirculation or backflow in the inducer occurs at low flow conditions and can lead to instabilities and cavitation-induced head breakdown. Backflow of an inducer with a tip clearance (TC) of τ = 0.32% and with no tip clearance (NTC) is examined with a series of computational fluid dynamics simulations. Removing the TC eliminates tip leakage flow; however, backflow is still observed. In fact, the NTC case showed a 37% increase in the length of the upstream backflow penetration. Tip leakage flow does instigate a smaller secondary leading edge tip vortex that is separate from the much larger backflow structure. A comprehensive analysis of these simulations suggests that blade inlet diffusion, not tip leakage flow, is the fundamental mechanism leading to the formation of backflow.
The Design and Validation of a Thermal Boundary Layer Wall Plate
Authors: Biles Drummond , Ebadi Alireza , Allard Michael P. , White Christopher M.
Published: May 2019

A feedback controlled thermal wall plate designed to investigate thermal boundary layer flows is described and validated. The unique capabilities of the design are the ability to modify the thermal boundary conditions in a variety of ways or to hold the wall-temperature fixed even when the flow above the wall is unsteady and strongly three-dimensional. These capabilities allow for the generation and study of thermal transport in nonequilibrium boundary layer flows driven by different perturbations and of varying complexity. The thermal wall plate and the experimental facility in which the thermal wall plate is installed are first described. The wall-plate is then validated in a zero-pressure-gradient (ZPG) boundary layer flow for conditions of a uniform wall temperature and a temperature step. It is then shown that the wall temperature can be held constant even when a hemisphere body is placed on the wall that produces large localized variations in the convective heat transfer coefficient. Last, since the thermal wall plate is intended to support the study of thermal transport in a variety of nonequilibrium boundary layer flow, several possible experimental configurations are presented and described.
Comparison of DDES and URANS for Unsteady Tip Leakage Flow in an Axial Compressor Rotor
Authors: Liu Yangwei , Zhong Luyang , Lu Lipeng
Published: May 2019

Tip leakage vortex (TLV) has a large impact on compressor performance and should be accurately predicted by computational fluid dynamics (CFD) methods. New approaches of turbulence modeling, such as delayed detached eddy simulation (DDES), have been proposed, the computational resources of which can be reduced much more than for large eddy simulation (LES). In this paper, the numerical simulations of the rotor in a low-speed large-scale axial compressor based on DDES and unsteady Reynolds-averaged Navier–Stokes (URANS) are performed, thus improving our understanding of the TLV dynamic mechanisms and discrepancy of these two methods. We compared the influence of different time steps in the URANS simulation. The widely used large time-step makes the unsteadiness extremely weak. The small time-step shows a better result close to DDES. The time-step scale is related to the URANS unsteadiness and should be carefully selected. In the time-averaged flow, the TLV in DDES dissipates faster, which has a more similar structure to the experiment. Then, the time-averaged and instantaneous results are compared to divide the TLV into three parts. URANS cannot give the loss of stability and evolution details of TLV. The fluctuation velocity spectra show that the amplitude of high frequencies becomes obvious downstream from the TLV, where it becomes unstable. Last, the anisotropy of the Reynolds stress of these two methods is analyzed through the Lumley triangle to see the distinction between the methods and obtain the Reynolds stress. The results indicate that the TLV latter part in DDES is anisotropic, while in URANS it is isotropic.
Multi-Objective Optimization of Multistage Centrifugal Pump Based on Surrogate Model
Authors: Shuiguang Tong , Hang Zhao , Huiqin Liu , Yue Yu , Jinfu Li , Feiyun Cong
Published: May 2019

In this paper, the hydraulic efficiency optimization calculation method of a ten-stage centrifugal pump is researched. According to the hydraulic loss model, a multi-objective optimization calculation method based on surrogate models is proposed. In order to study the highly nonlinear relationship between key design variables and centrifugal pump external characteristic values, this paper builds the quadratic response surface, the radial basis Gaussian response surface, and Kriging three surrogate models using computer fluid dynamics (CFD) simulation analysis. Two types of calculation models (hydraulic loss model and three surrogate models) combined NSGA-Π genetic algorithm are applied to optimize the key design variables and to find the optimal solution of each model. The accuracy and effectiveness of the efficiency optimization methods based on the two types of calculation models are compared and analyzed. The results show that the calculation method of hydraulic loss model based on the semitheoretical and semi-empirical formula is less time-consuming but inaccurate. In contrast, the optimization method based on surrogate models using CFD simulation is accurate. What's more, comparing the surrogate models, the results based on the complete quadratic response surface model which make the efficiency of the first stage centrifugal pump reach 77.26% are more accurate.
Expression of emotional valence in pig closed-mouth grunts: Involvement of both source- and filter-related parameters
Authors: Briefer Elodie F. , Vizier Emilie , Gygax Lorenz , Hillmann Edna
Published: May 2019

Emotion expression plays a crucial role for regulating social interactions. One efficient channel for emotion communication is the vocal-auditory channel, which enables a fast transmission of information. Filter-related parameters (formants) have been suggested as a key to the vocal differentiation of emotional valence (positive versus negative) across species, but variation in relation to emotions has rarely been investigated. Here, whether pig (Sus scrofa domesticus) closed-mouth grunts differ in source- and filter-related features when produced in situations assumed to be positive and negative is investigated. Behavioral and physiological parameters were used to validate the animals' emotional state (both in terms of valence and arousal, i.e., bodily activation). Results revealed that grunts produced in a positive situation were characterized by higher formants, a narrower range of the third formant, a shorter duration, a lower fundamental frequency, and a lower harmonicity compared to negative grunts. Particularly, formant-related parameters and duration made up most of the difference between positive and negative grunts. Therefore, these parameters have the potential to encode dynamic information and to vary as a function of the emotional valence of the emitter in pigs, and possibly in other mammals as well.
Rheology of liquid metal particle-based polymer composites: A comparative study
Authors: Nesaei Sepehr , Cavanagh Davis James , Gozen Arda
Published: May 2019

Using room-temperature liquid metal particles as fillers in polymer composites (PCs) has recently been of utmost interest as the resultant composites exhibit improved toughness along with electrical and thermal conductivity. This paper presents a comprehensive study on shear and extensional rheology of the aqueous solutions (inks) of liquid EGaIn (eutectic gallium-indium) particle and poly(ethylene oxide)-based PCs. The rheology of this material system is compared to solid-state, rigid graphene-based PC inks having the same polymer matrix and filler concentrations. Results show that EGaIn-based PC inks exhibit unique rheological behavior that is inconsistent with that of the conventional rigid filler-based Polymer Nanocomposites (PNs), exemplified by increased extensional flow capability and elasticity. We postulate that the source of this behavior is the elastic nature of the oxide covered EGaIn particles. EGaIn-based PCs eliminate common trade-offs for conductive PCs and thus can have a significant impact in several technologies including solid-state energy storage and 3D-printing.
Signals trigger state-specific transcriptional programs to support diversity and homeostasis in immune cells
Authors: Fischer Cornelius , Metsger Maria , Bauch Sophia , Vidal Ramon , Böttcher Michael , Grote Phillip , Kliem Magdalena , Sauer Sascha
Published: May 2019

Single-cell data reveal the major transcriptional regulators for distinct macrophage states.
Turning off cellular stress
Authors: Williams Erin R.
Published: May 2019

Independently of autophagy, the kinases ULK1/2 promote stress granule disassembly and prevent the development of skeletal muscle disease.
Time-Restricted Inquiry-Based Learning Promotes Active Student Engagement in Undergraduate Zoology Laboratory
Authors: Sumranwanich Thitinun , Boonthaworn Kanpong , Singhakaew Sombat , Ounjai Puey
Published: May 2019

Organizing a zoology laboratory for an undergraduate course is often a challenge, particularly in a limited-resource setting, due to the vast variety of topics to cover and the limited numbers of preserved specimens and permanent slides. In zoology, the class structure generally takes the form of a lecture demonstration followed by sample exhibition stations. This setting often fails to actively engage the majority of students in exploring the specimens. Here we propose an alternative organization of a zoology class lab format comprised of short guided-inquiry, time-restricted lab stations, and a freely structured follow-up project intended to increase attention and conceptual understanding of the lab topic. The lab is designed in two parts: a 10-minute in-class rotation portion, where small groups of students take turns investigating specimens following an instructor demonstration, and an after-class group assignment. We implemented the strategy for two years, and it is clear that our approach significantly increased students’ active engagement in the class. The time-restricted scheme ensures all students participate despite limited resources, while the guided instructions keep the students focused on the topic. Furthermore, the team assignment portion, in particular the media creation aspect, promoted teamwork among group members.
The Genome Solver Project: Faculty Training and Student Performance Gains in Bioinformatics
Authors: Mathur Vinayak , Arora Gaurav S. , McWilliams Mindy , Russell Janet , Rosenwald Anne G.
Published: May 2019

Bioinformatics brings together biology, mathematics, statistics, and computer science to analyze biological sequence information. Anyone with a computer, access to the Internet, and basic training in this field can contribute to genomics research. Yet many biology faculty feel they lack training in the use of bioinformatics tools and therefore include little bioinformatics content in their courses. To overcome this challenge, the Genome Solver Project was created to empower undergraduate faculty by offering training and resources for creating hands-on bioinformatics course materials. In this study, we show the results of one survey completed directly after the workshop and a further follow-up survey to gain insight into the impact the workshop had on faculty willingness to include bioinformatics content in their courses and what challenges they still faced. We also measured student performance at five different institutions using a 20-question multiple-choice quiz delivered before and after bioinformatics instruction. Data collected from 640 students at these five schools demonstrated student performance increased, suggesting that bioinformatics training workshops can be an effective means of encouraging faculty to engage in bioinformatics instruction and positively influence student learning.
Problem-Solving Exercise for Undergraduate Students Involving the Japanese Fermented Food Natto
Authors: Yoshiyama Yoko , Shima Jun , Fushiki Toru
Published: May 2019

Natto is a traditional Japanese food made from soybeans fermented by
Bacillus subtilis natto
. Because natto is high in protein and contains healthful bacteria, dieticians and producers have campaigned for higher consumption of natto in areas such as Kansai, where our university is located. One of the reasons for the low consumption of natto is its distinctive flavor. As a problem-solving exercise, undergraduate students attempted to make natto more marketable. Students set a goal of modifying natto flavor by adding spices to achieve flavors deemed palatable by organoleptic tests. During the exercise, they noticed that lemongrass,
Cymbopogon citratus
, had a flavor-masking ability that reduced the intensity of natto flavor, and they finally determined that it was a useful food additive to make natto marketable. The exercise was an active learning process that effectively induced voluntary student effort of to solve problems originating from microorganisms.
With Big Data Comes Big Responsibilities for Science Equity Research
Authors: Ballen Cissy J. , Holmegaard Henriette Tolstrup
Published: May 2019

Our ability to collect and access large quantities of data over the last decade has been revolutionary for many social sciences. Suddenly, it is possible to measure human behavior, performance, and activity on an unprecedented scale, opening the door to fundamental advances in discovery and understanding. Yet such access to data has limitations that, if not sufficiently addressed and explored, can result in significant oversights. Here we discuss recent research that used data from a large global sample of high school students to demonstrate, paradoxically, that in nations with higher gender equality, fewer women pursued science, technology, engineering, and mathematics (STEM) degrees than would be expected based on aptitude in those subjects. The
reasons
for observed patterns is central to current debates, with frequent disagreement about the nature and magnitude of problems posed by the lack of female representation in STEM and the best ways to deal with them. In our international efforts to use big data in education research, it is necessary to critically consider its limitations and biases.
Comics as an Educational Resource To Teach Microbiology in the Classroom
Authors: Morel María , Peruzzo Nicolás , Juele Alejandro Rodriguez , Amarelle Vanesa
Published: May 2019

New educational resources are being implemented as an initiative to foster learning. In order to contribute to the toolkit of innovative educational resources, we developed a microbiology comic book. The aim of this comic is to provide educators with a fun, accessible, and rigorous way to generate awareness of the invisible world that surrounds us and that inhabits us. Bacteria have a reputation as harmful and disgusting entities. Mass media, with advertisements of disinfectants, soaps, and house cleaning products, are sending a distorted message about microbes. We must debunk these misconceptions and emphasize the importance of microorganisms, and particularly bacteria, in the environment and our lives. Education is the means to this end, and therefore this comic is intended to help educators teach microbiology in an attractive, accurate, and straightforward way. Here, we present this educational tool and give some tips on the different themes that can be addressed in the classroom using this resource.
Vegetation and habitat change in southern California through the Middle Miocene Climatic Optimum: Paleoenvironmental records from the Barstow Formation, Mojave Desert, USA
Authors: Loughney Katharine M. , Hren Michael T. , Smith Selena Y. , Pappas Janice L.
Published: May 2019

The Barstow Formation (ca. 19–13 Ma) of southern California, USA, is a terrestrial sequence known for its diverse Miocene mammalian faunas. The formation spans the Middle Miocene Climatic Optimum (MMCO; 17–14 Ma) and offers the opportunity to study environmental change during the last major interval of global warming of the Cenozoic. We combined isotopic analyses of carbon and hydrogen from sedimentary n-alkanes and bulk soil organic matter with analysis of phytoliths (plant silica) and diatoms to reconstruct vegetation composition, habitat structure, and moisture dynamics through the formation. The δ13C and δD of long-carbon-chain n-alkanes derived from terrestrial plants and preserved in sediments of the Barstow Formation record drying prior to the MMCO and through the Middle Miocene Climatic Transition (MMCT; beginning ca. 14 Ma), punctuated by increased moisture in fluvial environments during the peak of the MMCO. Variable isotopic results relate to changes in moisture, driven partly by facies, vegetation composition, tectonic activity, and climatic variability coinciding with intervals of high pCO2. Phytolith assemblages are dominated by forest indicators in riparian habitats during the MMCO, and grass morphotypes constitute significant components of phytolith assemblages after the MMCO, indicating a shift to drier, more open-canopy habitats. The establishment of dry, wooded grasslands in the Barstow Basin coincides with the beginning of the MMCT and cooling sea-surface temperatures in the Pacific Ocean. Our results indicate that moist, closed-canopy habitats formed in southern California during climatic warming, followed by savannah during climatic cooling and the shift to seasonal precipitation regimes.
Unique case of delayed external iliac artery pseudoaneurysm after a remote total hip arthroplasty
Authors: Shahait Awni D , Chagas Cristian , Hussein Shakir , Bhat Zeenat
Published: May 2019

Vascular intrapelvic complications due to total hip arthroplasty failure are uncommon, with less than 30 cases reported in the literature. Herein, we report a case of unusual asymptomatic delayed vascular complication after 10 years from right total hip arthroplasty. A man in mid-50s, with multiple comorbidities including end-stage renal disease. The patient was admitted for the renal transplant surgery. Intraoperatively, right external iliac artery pseudoaneurysm was discovered, which required the transplantation to be done on the left side. After recovery from the renal transplant surgery, the patient underwent resection of the right external iliac artery pseudoaneurysm with primary anastomosis by vascular surgery, with resection of the migrated screw by orthopaedic surgery.
Gangrenous ischaemic colitis following lung wedge resection
Authors: Hayashi Kazuki , Ohshio Yasuhiko , Hanaoka Jun
Published: May 2019

A 77-year-old man, who was taking prednisolone 7.5 mg, underwent wedge resection for nodules in the right lower lobe of the lung. The nodules were diagnosed as amyloid tumour. On the sixth postoperative day, sudden tachycardia, fever, creatine phosphokinase increase, renal dysfunction and metabolic acidosis were observed. CT showed no signs of infection, exacerbation of interstitial pneumonia, pulmonary embolism or occlusion in the major vessels of the mesentery. Exploratory laparotomy revealed intestinal necrosis in the inferior mesenteric artery area, and left hemicolectomy was performed. Postoperative pathological examination revealed gangrenous ischaemic colitis. Although gangrenous ischaemic colitis is not a complication specific to general thoracic surgery, it can be fatal. Because of the high risk of developing gangrenous ischaemic colitis in elderly patients and the increase in concomitant diseases, thoracic surgeons should always be mindful of the condition.
Synchronous recurrence of concurrent colon adenocarcinoma and dedifferentiated liposarcoma
Authors: Jung Eric E , Heinemann F Scott , Egelston Colt A , Wang Jennifer , Pollock Raphael E , Lee Peter P , Tseng William W
Published: May 2019

A 62-year-old man presented with concurrent sigmoid colon adenocarcinoma and small bowel mesenteric dedifferentiated liposarcoma. Following surgical resection of the colon cancer, complete excision of the mesenteric sarcoma and adjuvant folinic acid, fluorouracil and oxaliplatin (FOLFOX) chemotherapy, the patient demonstrated no radiological evidence of disease for more than 2 years. The patient then developed synchronous recurrence of both cancers: the colon cancer metastasised to the liver and a pelvic lymph node, and the liposarcoma recurred in the original location. The patient underwent additional chemotherapy with complete response of the metastatic colon cancer and stable disease for the liposarcoma. The recurrent mesenteric tumour was subsequently resected. Although concurrent cancers have been reported, this unique case of synchronous recurrence raises interesting hypotheses regarding host–tumour interaction and immune surveillance.
Significance of dynamic contour tonometry in evaluation of progression of glaucoma in patients with a history of laser refractive surgery
Authors: Lee Sang Yeop , Kim Eun Woo , Choi Wungrak , Park Chan Keum , Kim Sangah , Bae Hyoung Won , Seong Gong Je , Kim Chan Yun
Published: May 2019

Aims

In this study, we tested the hypothesis that intraocular pressure (IOP) parameters measured by dynamic contour tonometry (DCT) would be more relevant in progression of glaucoma when there is a history of laser refractive surgery (LRS) than the IOP parameters measured by Goldmann applanation tonometry (GAT) or calculated by correction formulae.

Methods

Ninety-eight eyes in 54 patients with open-angle glaucoma and a history of LRS were included in this retrospective study. IOP was measured by both GAT and DCT during follow-up. Baseline, mean, and peak IOP, IOP fluctuation, and IOP reduction were measured by each tonometry method. Corrected IOP parameters using central corneal thickness and mean keratometry values were also analysed. Clustered logistic regression was used to identify variables correlated with progression of glaucoma. Areas under the curve (AUCs) for correlated variables were also compared.

Results

The mean DCT value (OR 1.36, p=0.024), peak DCT value (OR 1.19, p=0.02) and pattern SD (OR 1.10, p=0.016) were significant risk factors for progression. There was a significant difference in the predictive ability of the mean DCT and GAT values (AUC 0.63 and 0.514, respectively; p=0.01) and of the peak DCT and GAT values (0.646 and 0.503, respectively, p=0.009). The AUCs for corrected IOP did not exceed those of DCT.

Conclusions

IOP measurements were more associated with progression of glaucoma when measurements were obtained by DCT than by GAT or correction formulae in eyes with a history of LRS.
Angiomatosis of the breast: a clinicopathological and immunophenotypical characterisation of seven cases
Authors: Ginter Paula S , McIntire Patrick J , Irshaid Lina , Liu Yi-Fang , Shin Sandra J
Published: May 2019

Aims

Mammary angiomatosis is a rare, benign vascular lesion that morphologically mimics low-grade angiosarcoma (LGAS). To date, only occasional reports of this entity have been published, none of which included analysis by immunohistochemistry. The purpose of this study was to further characterise mammary angiomatosis by clinical, histological, and immunohistochemical means while emphasising distinguishing features from LGAS.

Methods

Seven cases of primary mammary angiomatosis were evaluated. For one patient, a subsequent recurrence was also evaluated.

Results

All patients were female with a median age at presentation of 51 years (range: 19–58 years). The most common clinical presentation was that of a palpable abnormality or mass (5/8) and the median primary tumour size was 3.1 cm (range: 2–9 cm). Of the six patients with follow-up, one developed a recurrence 6 years after initial presentation. Histologically, all cases were composed of variably sized ectatic, thin-walled vessels lined by flat normochromic endothelium diffusely infiltrating mammary stroma. Where present, lesional vessels infiltrated between and around terminal duct lobular units but not into individual intralobular stroma. Most cases (6/8) showed a combination of lymphatic-appearing and haemangiomatous-appearing vessels. Lymphatic-appearing vessels were D2-40 positive in all but one case. D2-40 was negative or weak in haemangiomatous-appearing vessels. All lesional vessels were CD31 positive. Ki-67 indices were <1% in all but one case (5%).

Conclusions

Mammary angiomatosis is a rare vascular lesion that shares clinical, morphological and immunohistochemical features with LGAS; however, certain key traits make the distinction possible.
Simultaneous R2*and quantitative susceptibility mapping measurement enables differentiation of thrombus hematocrit and age: an in vitro study at 3 T
Authors: Christiansen Spencer D , Liu Junmin , Boffa Michael B , Drangova Maria
Published: May 2019

Background

The efficacy of acute ischemic stroke treatment is affected by thrombus composition and age, yet no diagnostic method capable of quantitative thrombus characterization currently exists. This in vitro study evaluates the use of R2*, quantitative susceptibility mapping (QSM), and proton density fat fraction (FF) maps derived from a single gradient echo (GRE) MRI acquisition for characterizing clot of various hematocrit, as well as added calcified and lipidic components, throughout aging.

Methods

Two thrombus phantoms containing porcine clots (10–60% hematocrit, one with added calcium or lard) were scanned serially throughout 6 days of aging. Three-dimensional multi-echo GRE imaging was used to generate R2*, QSM, and FF maps, from which mean values for all clots at every time point were obtained. Receiver operating characteristic analysis was used to derive thresholds differentiating acute from chronic clot, and measured R2*and QSM were tested for their ability to estimate clot hematocrit.

Results

R2*and QSM varied minimally over the first 6 hours of aging (acute), and QSM was found to linearly relate to clot hematocrit. Beyond 6 hours (chronic), R2*and QSM increased considerably over time and hematocrit could be estimated from the R2*/QSM ratio. R2*and QSM thresholds of 22 s-1and 0.165 ppm differentiated acute from chronic clots with a sensitivity/specificity of 100%/100% and 85%/92%, respectively. QSM and FF maps definitively distinguished calcium and lipid, respectively, from clots of any hematocrit and age.

Conclusions

R2*, QSM, and FF from a single multi-echo GRE scan discriminated hematocrit and age, and distinguished calcification and lipid withinin vitro clot.
Flow diversion beyond the circle of Willis: endovascular aneurysm treatment in peripheral cerebral arteries employing a novel low-profile flow diverting stent
Authors: Schob Stefan , Hoffmann Karl-Titus , Richter Cindy , Bhogal Pervinder , Köhlert Katharina , Planitzer Uwe , Ziganshyna Svitlana , Lindner Dirk , Scherlach Cordula , Nestler Ulf , Meixensberger Jürgen , Quäschling Ulf
Published: May 2019

Background

Flow diversion (FD) has emerged as superior minimally invasive therapy for cerebral aneurysms. However, aneurysms of small peripheral vessel segments have not yet been adequately treatable. More specifically, currently established devices necessitate large microcatheters which impede atraumatic maneuvering. The Silk Vista Baby (SVB), a novel flow diverter, offers the as yet unique feature of deliverability via a 0.017 inch microcatheter. This study reports our first experience with the SVB in challenging intracranial vessels employing a vessel-specific tailored microcatheter strategy.

Materials and methods

25 patients (27 aneurysms) were prospectively included. A total of 30 SVBs were employed, predominantly targeting demanding aneurysms of the anterior communicating artery complex. The efficacy of the FD was assessed using two-dimensional vector-based perfusion and conventional digital subtraction angiography (DSA) after implantation and at the first follow-up at 3 months. The first follow-up was available in 22 patients.

Results

All devices were implanted without technical or clinical complications. Eleven treatments were performed using the recommended Headway 17. In 14 interventions the even more maneuverable Excelsior SL10 was used, which was previously tried and tested for safety ’in vitro’ as an alternative delivery system. Aneurysmal influx was strongly reduced after implantation. All parent vessels remained patent. 17/27 aneurysms were completely occluded at first follow-up (∼2.7 months), 6/27 aneurysms showed decreased influx or delayed washout and one remained unchanged. In three cases follow-up DSAs are remaining.

Conclusions

SVB provides enhanced controllability in vulnerable segments beyond the circle of Willis. Smaller variants (2.25 mm and 2.75 mm) can safely be implanted via the superiorly navigable Excelsior SL10. Hence, the SVB represents the next evolutionary step in minimally invasive treatment of cerebral aneurysms.
Clipping of recanalized intracerebral aneurysms initially treated by the Woven EndoBridge device
Authors: Pierot Laurent , Bannery Christophe , Batchinsky-Parrou Valery , Kleiber Jean-Charles , Soize Sebastien , Litre Claude Fabien
Published: May 2019

Background and purpose

Intrasaccular flow disruption using the Woven EndoBridge (WEB) is a safe and effective method to treat intracranial aneurysms, particularly wide neck bifurcation aneurysms. However mid term and long term follow-up imaging can show aneurysm remnant or recanalization, and retreatment is therefore sometimes necessary. In most cases, retreatment is performed using an endovascular approach. The present series reports and analyzes aneurysm clipping of recanalized or incompletely occluded aneurysms following WEB treatment.

Methods

All patients treated with the WEB device since the beginning of our experience in June 2011 were prospectively collected in a local database. Among them, patients who were retreated by clipping for aneurysm remnants were included in the present series.

Results

In the cumulative population of 130 patients with aneurysms treated by the WEB device from June 2011 to February 2019, 4 patients (3.1%) were retreated with surgical clipping due to incomplete occlusion (2 patients) and aneurysm recanalization (2 patients). Three of the four aneurysms retreated (75%) were located in the middle cerebral artery and one in the anterior communicating artery (25.0%). The aneurysm was ruptured in 1 of 4 patients (25%). Clipping was performed 10–54 months after initial treatment with the WEB. Surgical exposure showed that the WEB device was inside the aneurysm sac in all cases. Clipping was easily performed in all but 1 case. Control DSA showed complete occlusion in two aneurysms and a neck remnant in two.

Conclusion

Clipping is a feasible option for treating aneurysm remnants following initial treatment with intrasaccular flow disruption using the WEB.