bluuebunny/crossref_metadata_2025 huggingface dataset:
Multistage Decision Processes: The Impact of Attribute Order on How Consumers Mentally Represent Their Choice
Authors: Schrift Rom Y , Parker Jeffrey R , Zauberman Gal , Srna Shalena
Published: September 2017

With the ever-increasing number of options from which consumers can choose, many decisions are made in stages. Whether using decision tools to sort, screen, and eliminate options, or intuitively trying to reduce the complexity of a choice, consumers often reach a decision by making sequential, attribute-level choices. The current article explores how the order in which attribute-level choices are made in such multistage decisions affects how consumers mentally represent and categorize their chosen option. The authors find that attribute choices made in the initial stage play a dominant role in how the ultimately chosen option is mentally represented, while later attribute choices serve only to update and refine the representation of that option. Across 13 studies (six of which are reported in the supplemental online materials), the authors find that merely changing the order of attribute choices in multistage decision processes alters how consumers (1) describe the chosen option, (2) perceive its similarity to other available options, (3) categorize it, (4) intend to use it, and (5) replace it. Thus, while the extant decision-making literature has mainly explored how mental representations and categorization impact choice, the current article demonstrates the reverse: that the choice process itself can impact mental representations.
Asymptomatic Cardiovascular Syphilis With Aortic Regurgitation Requiring Surgical Repair in an HIV-Infected Patient
Authors: Graciaa Daniel S , Mosunjac Marina B , Workowski Kimberly A , Kempker Russell R
Published: September 2017

A 47-year-old man with HIV infection presented 10 years after initial secondary syphilis diagnosis and treatment for routine follow-up. His HIV was well controlled on antiretroviral therapy. Rapid plasma reagin was 1:1, and TP-PA was reactive. Physical examination revealed a wide pulse pressure, a systolic murmur, and an early diastolic decrescendo murmur. Echocardiogram revealed moderate to severe aortic regurgitation, and subsequent computed tomography angiogram showed a 6.8-cm fusiform aneurysm of the proximal ascending aorta. Aortic valve and ascending hemiarch replacement were performed. Pathology showed adventitial inflammation with plasma cells, gumma-like amorphous areas surrounded by histiocytes, and giant cells with calcified plaques. Cardiovascular syphilis, while rare, remains a relevant cause of aortic aneurysm, even in previously treated patients. The physical exam can be critical in identifying this potentially fatal complication.
Comparison of Expert Opinion, Majority Rule, and a Clinical Prediction Rule to Estimate Distal Radius Malalignment
Authors: Luokkala Toni , Flinkkilä Tapio , Paloneva Juha , Karjalainen Teemu V.
Published: September 2017

Objectives:

To investigate the ability of individual surgeons [expert opinion (EO)] to predict distal radius fracture (DRF) healing above a threshold malalignment compared with the majority prediction of the group of surgeons [“majority rule,” (MR)] and a statistically derived clinical prediction formula [Edinburgh wrist calculator (EWC)].

Design:

Comparative diagnostic study from prospectively collected data of consecutive patients.

Setting:

Two academic level 1 and 1 academic level 2 trauma centers.

Patients/Participants:

Eighteen surgeons assessed probability of healing above a threshold malalignment (often referred to as fracture “instability”) for 71 fractures based on radiographs taken initially and after closed reduction and cast application. The probability of losing alignment according to the EWC was dichotomized (likely to lose alignment ≥0.5 vs. unlikely <0.5).

Main Outcome Measures:

Accuracy parameters of prediction of EO, MR, and EWC.

Results:

EWC and MR demonstrated higher accuracy (0.77 and 0.75, respectively) and sensitivity (0.95 and 0.79, respectively) compared with EO (accuracy, 0.66 and sensitivity, 0.58) for predicting healing above the threshold malalignment. Reliability was higher for MR (kappa 0.88) than for EWC (kappa 0.63) or EO (kappa coefficient 0.44). The negative predictive value of the EWC for healing above a threshold of malalignment was excellent (0.97).

Conclusions:

Surgeon opinion is not reliable or accurate for predicting loss of alignment of a DRF above a threshold malalignment after closed reduction and immobilization. Dichotomized EWC may be a useful tool in predicting loss of alignment (instability) of a DRF.

Level of Evidence:

Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.
Utilization and Outcomes of Temporary Mechanical Circulatory Support for Graft Dysfunction After Heart Transplantation
Authors: Phan Kevin , Luc Jessica G. Y. , Xu Joshua , Maltais Simon , Stulak John M. , Yan Tristan D. , Tchantchaleishvili Vakhtang
Published: September 2017

Graft dysfunction is the main cause of early mortality after heart transplantation. In cases of severe graft dysfunction, temporary mechanical circulatory support (TMCS) may be necessary. The aim of this systematic review was to examine the utilization and outcomes of TMCS in patients with graft dysfunction after heart transplantation. Electronic search was performed to identify all studies in the English literature assessing the use of TMCS for graft dysfunction. All identified articles were systematically assessed for inclusion and exclusion criteria. Of the 5,462 studies identified, 41 studies were included. Among the 11,555 patients undergoing heart transplantation, 695 (6.0%) required TMCS with patients most often supported using venoarterial extracorporeal membrane oxygenation (79.4%) followed by right ventricular assist devices (11.1%), biventricular assist devices (BiVADs) (7.5%), and left ventricular assist devices (LVADs) (2.0%). Patients supported by LVADs were more likely to be supported longer (p = 0.003), have a higher death by cardiac event (p = 0.013) and retransplantation rate (p = 0.015). In contrast, patients supported with BiVAD and LVAD were more likely to be weaned off support (p = 0.020). Overall, no significant difference was found in pooled 30 day survival (p = 0.31), survival to discharge (p = 0.19), and overall survival (p = 0.51) between the subgroups. Temporary mechanical circulatory support is an effective modality to support patients with graft dysfunction after heart transplantation. Further studies are needed to establish the optimal threshold and strategy for TMCS and to augment cardiac recovery and long-term survival.
Elevated Postvoid Residual Urine Volume: Identifying Risk Factors and Predicting Resolution in Women With Pelvic Organ Prolapse
Authors: Ulrich Amanda , Davis Patricia , Propst Katie , O'Sullivan David M. , Tulikangas Paul
Published: September 2017

Objectives

This study aims to identify risk factors for elevated preoperative postvoid residual (PVR) and persistently elevated postoperative PVR and to evaluate the resolution rate of elevated PVR urine volume in patients undergoing reconstructive surgery for pelvic organ prolapse (POP).

Methods

This was a retrospective cohort study comparing 50 women with elevated preoperative PVR (≥100 mL) and 50 women with normal PVR (<100 mL). Preoperative demographic, physical examination, urodynamic data, type of surgery performed, and postoperative trial of void data were collected. Variables were evaluated for association with elevated PVR using Student t test or Mann-Whitney U test, and χ2 or Fisher exact test.

Results

The elevated PVR cohort was older (65.5 ± 13.3 vs 60.6 ± 10.1 years, P = 0.04). The cohorts did not differ by body mass index, parity, number of cesarean deliveries, prior hysterectomy, incontinence, prolapse surgery, menopausal status, hormone replacement therapy, history of recurrent urinary tract infections, diabetes mellitus, or maximum bladder capacity. Most patients had preoperative anterior prolapse stage 2 or 3. Complaints of incontinence, incomplete bladder emptying, and overactive bladder did not differ between groups. Performed Surgical procedures, cystoscopy findings, and rate of postoperative trial of void failures did not differ between groups. One patient per cohort learned clean intermittent self-catheterization for persistently elevated PVR.

Conclusions

All women undergoing surgery for POP had postoperative resolution of elevated PVR. Patients with nonneurogenic-elevated PVR can be reassured that bladder emptying will improve after surgical repair of POP.
Increasing Anteroposterior Genital Hiatus Widening Does Not Limit Apical Descent for Prolapse Staging During Valsalva's Maneuver: Effect on Symptom Severity and Surgical Decision Making
Authors: Guanzon Anna , Heit Michael , Khoder Waseem
Published: September 2017

Objective

Determine if anteroposterior genital hiatus (GH) widening obscures rather than facilitates signs and symptoms, inadvertently altering management decisions for women with pelvic organ prolapse (POP) during Valsalva's Maneuver, at a given total vaginal length (TVL).

Methods

We performed a retrospective cohort with nested cross-sectional study of patients who underwent POP surgery. Data from obstetric and gynecologic history, preoperative and postoperative physical examinations, and 20-item Pelvic Floor Distress Inventory (PFDI-20) and 7-item Pelvic Floor Impact Questionnaire (PFIQ-7) scores were extracted. Study participants were compared in 2 groups: anteroposterior widened (>3 cm) and not widened (≤3 cm) GH, for baseline leading edge and POP stage, while controlling for TVL. Baseline PFDI-20 and PFIQ-7 scores were evaluated within GH groups. Delta GH, PFDI-20, and PFIQ-7 scores after apical suspension with and without posterior colporrhaphy were compared to assess the clinical value of the procedure.

Results

Study participants with anteroposterior GH widening during Valsalva maneuver had greater baseline leading edge descent and higher POP stage compared with those without anteroposterior GH widening after controlling for TVL. Baseline PFDI-20 and PFIQ-7 scores were similar within both GH categories controlling for prolapse severity. Adding posterior colporrhaphy to apical suspension resulted in a greater anteroposterior GH reduction without improving delta PFDI-20 or PFIQ-7 scores.

Conclusions

Facilitation through herniation rather than obscuration from anteroposterior GH widening explains why patients will not be undertreated based on signs and symptoms of disease. Adding posterior colporrhaphy to apical suspension more effectively reduces anteroposterior GH widening without differential improvement in symptoms rendering the operation to no more than a cosmetic procedure.
Avoiding ascertainment bias in the maximum likelihood inference of phylogenies based on truncated data
Authors: Tamuri Asif , Goldman Nick
Published: September 2017

Some phylogenetic datasets omit data matrix positions at which all taxa share the same state. For sequence data this may be because of a focus on single nucleotide polymorphisms (SNPs) or the use of a technique such as restriction site-associated DNA sequencing (RADseq) that concentrates attention onto regions of differences. With morphological data, it is common to omit states that show no variation across the data studied. It is already known that failing to correct for the ascertainment bias of omitting constant positions can lead to overestimates of evolutionary divergence, as the lack of constant sites is explained as high divergence rather than as a deliberate data selection technique. Previous approaches to using corrections to the likelihood function in order to avoid ascertainment bias have either required knowledge of the omitted positions, or have modified the likelihood function to reflect the omitted data. In this paper we indicate that the technique used to date for this latter approach is a conditional maximum likelihood (CML) method. An alternative approach — unconditional maximum likelihood (UML) — is also possible. We investigate the performance of CML and UML and find them to have almost identical performance in the phylogenetic SNP dataset context. We also make some observations about the nucleotide frequencies observed in SNP datasets, indicating that these can differ systematically from the overall equilibrium base frequencies of the substitution process. This suggests that model parameters representing base frequencies should be estimated by maximum likelihood, and not by empirical (counting) methods.
Adult facilitation becomes competition as juvenile soapberry bugs age
Authors: Cenzer Meredith L
Published: September 2017

Whether intraspecific interactions are facilitative or competitive may change across individual ontogeny. In plant-feeding insects, the direction of this interaction is likely to be mediated by host plant defenses. Here I conducted two experiments looking at the direct effect of a physical seed defense and the role of intraspecific facilitation in reducing the effects of that defense for juveniles. I first demonstrate that juveniles of the red-shouldered soapberry bug (Jadera haematoloma) are severely inhibited by the tough seed coat of their host plant, leading to high mortality early in development. Adults, in contrast, can create holes through which other individuals could potentially feed. I then manipulated whether or not seeds experienced adult feeding on two host plant species: a well-defended native host, balloon vine (Cardiospermum corindum) and a poorly defended introduced golden rain tree species (Koelreuteria elegans). I measured the effect of prior adult feeding on survival, development time, and final body size of soapberry bug juveniles. Survival in the first week of development was dramatically improved by prior adult feeding on both hosts. However, the benefits of prior adult feeding ceased after the first week of development and shifted to having a negative effect on performance. These results indicate that adults breaking through the seedcoat initially facilitate juveniles, but that this facilitation becomes competition as juveniles age.
Multiplane and Spectrally-Resolved Single Molecule Localization Microscopy with Industrial Grade CMOS Cameras
Authors: Babcock Hazen P.
Published: September 2017

In this work we explore the use of industrial grade CMOS cameras for single molecule localization microscopy (SMLM). We show that the performance of these cameras in single imaging plane SMLM applications is comparable to much more expensive scientific CMOS (sCMOS) cameras. We show that these cameras can be used in more demanding biplane, multiplane and spectrally resolved SMLM applications. The 10-40× reduction in camera cost makes it practical to build SMLM setups with 4 or more cameras. In addition we provide open-source software for simultaneously controlling multiple CMOS cameras and for the reduction of the movies that are acquired to super-resolution images.
Correlative three-dimensional fluorescence and refractive index tomography: bridging the gap between molecular specificity and quantitative bioimaging
Authors: Kim Kyoohyun , Park Wei Sun , Na Sangchan , Kim Sangbum , Kim Taehong , Heo Won Do , Park YongKeun
Published: September 2017

Optical diffraction tomography (ODT) provides label-free three-dimensional (3D) refractive index (RI) measurement of biological samples. However, due to the nature of the RI values of biological specimens, ODT has limited access to molecular specific information. Here, we present an optical setup combining ODT with three-channel 3D fluorescence microscopy, to enhance the molecular specificity of the 3D RI measurement. The 3D RI distribution and 3D deconvoluted fluorescence images of HeLa cells and NIH-3T3 cells are measured, and the cross-correlative analysis between RI and fluorescence of live cells are presented.
Minimizing carry-over PCR contamination in expanded CAG/CTG repeat instability applications
Authors: Aeschbach Loréne , Dion Vincent
Published: September 2017

Expanded CAG/CTG repeats underlie the aetiology of 14 neurological and neuromuscular disorders. The size of the repeat tract determines in large part the severity of these disorders with longer tracts causing more severe phenotypes. Expanded CAG/CTG repeats are also unstable in somatic tissues, which is thought to modify disease progression. Routine molecular biology applications involving these repeats, including quantifying their instability, are plagued by low PCR yields. This leads to the need for setting up more PCRs of the same locus, thereby increasing the risk of carry-over contamination. Here we aimed to reduce this risk by pre-treating the samples with a Uracil N-Glycosylase (Ung) and using dUTP instead of dTTP in PCRs. We successfully applied this method to the PCR amplification of expanded CAG/CTG repeats, their sequencing, and their molecular cloning. In addition, we optimized the gold-standard method for measuring repeat instability, small-pool PCR, such that it can be used together with Ung and dUTP-containing PCRs, without compromising data quality. We expect that the protocols herein to be applicable for molecular diagnostics of expanded repeat disorders and to manipulate other tandem repeats.
Evaluating the Functional Pore Size of Chloroplast TOC and TIC Protein Translocons
Authors: Ganesan Iniyan , Shi Lan-Xin , Labs Mathias , Theg Steven M.
Published: September 2017

The degree of residual structure retained by proteins while passing through biological membranes is a fundamental mechanistic question of protein translocation. Proteins are generally thought to be unfolded while transported through canonical proteinaceous translocons, which has historically been the thought for the translocons of the outer and inner chloroplast envelope membranes (TOC and TIC). Here, we readdressed the issue and found that medium-sized tightly folded proteins such as the 22 kDa dihydrofolate reductase (DHFR) can be tolerated by TOC and TIC. Chimeric DHFR fused with RuBisCO small subunit transit peptide (tp22DHFR) was found to be imported into chloroplasts in complex with its stabilizing ligand, methotrexate (MTX), in a folded conformation. Following import, both mature tp22DHFR and MTX were found in the chloroplast stroma. A subsaturating concentration of MTX was used to exclude the possibility that MTX was stripped off tp22DHFR, independently imported into the chloroplasts, and reassociated with imported tp22DHFR. Independent MTX import was further excluded by use of fluorescein conjugated MTX (FMTX), which has very slow membrane transport rates relative to unconjugated MTX. The TOC/TIC pore size was determined by probing the translocons with particles of fixed diameter and found to be greater than 25.6 Å, large enough to support folded DHFR import. The pore size is also larger than those of the mitochondrial protein translocons that have a requirement for protein unfolding.

SIGNIFICANCE

The chloroplast TOC and TIC translocons are responsible for the import of up to 95% of all chloroplast proteins and are therefore essential for plastid biogenesis and photosynthesis. However, the mechanisms of protein import into chloroplasts are not well understood. The TOC/TIC translocons have long been suggested to have a strong unfoldase activity relative to other comparable protein translocons. Here, we present data suggesting that this is not true, and that instead, they possess a relatively large pore size. This identifies TOC and TIC as rather unique protein translocons capable of transporting folded proteins across a double membrane barrier, which has important implications in the mechanisms of TOC/TIC function and biogenesis of photosynthetic proteins.

Classification - Biochemistry
Thermal Tolerance is linked with Virulence in a Fish Pathogen
Authors: Ashrafi Roghaieh , Bruneaux Matthieu , Sundberg Lotta-Riina , Pulkkinen Katja , Valkonen Janne , Ketola Tarmo
Published: September 2017

Although increase in temperatures may boost the number of pathogens, a complex process involving the interaction of a susceptible host, a virulent strain, and environmental factors would influence disease virulence in unpredictable ways. Here we explored if the virulence of an environmentally growing opportunistic fish pathogen,Flavobacterium columnare, would be malleable to evolutionary changes via correlated selection on thermal tolerance. Virulence among the strains increased over years, but tolerance to higher temperatures was associated with reduced virulence. Our results suggest that observed increase in frequency of columnaris epidemics over the last decade is most likely associated with increased length of growing season, or other time dependent change in environment, rather than increased regional average temperatures. Our results also indicate that most virulent bacteria had weaker ability to tolerate outside host environments, which suggest trade-off between more obligate pathogen behaviour and ability to grow outside host.
Anoctamin 9/TMEM16J is a Cation Channel Activated by cAMP/PKA Signal
Authors: Kim Hyungsup , Kim Hyesu , Lee Jesun , Lee Byeongjun , Kim Heeryang , Jung Jooyoung , Lee Mi-Ock , Oh Uhtaek
Published: September 2017

Anoctamins are membrane proteins that consist of 10 homologs. ANO1 and ANO2 are anion channels activated by intracellular calcium that meditate numerous physiological functions. ANO6 is a scramblase that redistributes phospholipids across the cell membrane. However, the others are not well characterized. We found ANO9/TMEM16J is a cation channel activated by a cAMP-dependent PKA. Intracellular cAMP activated robust currents in whole-cells expressing ANO9 and inhibited by PKA blockers. A cholera toxin and purified PKA also activated ANO9. The cAMP-induced ANO9 currents were permeable to cations. The mutation of a possible phosphorylation site at Ser245 elicited a block of the cAMP-dependent activation. High levels ofAno9transcripts were found in intestines. Human intestinal SW480 cells showed cAMP-dependent currents. We conclude that ANO9 is a cation channel activated by the cAMP/PKA pathway and could play a role in intestine function.
Drivers of diversity in individual life courses: Sensitivity of the population entropy of a Markov chain
Authors: Steiner Ulrich K. , Tuljapurkar Shripad
Published: September 2017

Individuals differ in their life courses, but how this diversity is generated, how it has evolved and how maintained is less understood. However, this understanding is crucial to comprehend evolutionary and ecological population dynamics. In structured populations, individual life courses represent sequences of stages that end in death. These sequences can be described by a Markov chain and individuals diversify over the course of their lives by transitioning through diverse discrete stages. The rate at which stage sequences diversify with age can be quantified by the population entropy of a Markov chain. Here, we derive sensitivities of the population entropy of a Markov chain to identify which stage transitions generate—or contribute—most to diversification in stage sequences, i.e. life courses. We then use these sensitivities to reveal potential selective forces on the dynamics of life courses. To do so we correlated the sensitivity of each matrix element (stage transition) with respect to the population entropy, to its sensitivity with respect to fitness λ, the population growth rate. Positive correlation between the two sensitivities would suggest that the stage transitions that selection has acted most strongly on (sensitivities with respect to λ) are also those that contributed most to the diversification of life courses. Using an illustrative example on a seabird population, the Thick-billed Murres on Coats Island, that is structured by reproductive stages, we show that the most influential stage transitions for diversification of life courses are not correlated with the most influential transitions for population growth. Our finding suggests that observed diversification in life courses is neutral rather than adaptive. We are at an early stage of understanding how individual level dynamics shape ecological and evolutionary dynamics, and many discoveries await.
Input-dependent modulation of MEG gamma oscillations reflects gain control in the visual cortex
Authors: Orekhova Elena V. , Sysoeva Olga V. , Schneiderman Justin F. , Lundström Sebastian , Galuta Ilia A. , Goiaeva Dzerasa E. , Prokofyev Andrey O. , Riaz Bushra , Keeler Courtney , Hadjikhani Nouchine , Gillberg Christopher , Stroganova Tatiana A.
Published: September 2017

Gamma-band oscillations arise from the interplay between neural excitation (E) and inhibition (I) and may provide a non-invasive window into the state of cortical circuitry. A bell-shaped modulation of gamma response power by increasing the intensity of sensory input was observed in animals and is thought to reflect neural gain control. Here we sought to find a similar input-output relationship in humans with MEG via modulating the intensity of a visual stimulation by changing the velocity/temporal-frequency of visual motion.

In the first experiment, adult participants observed static and moving gratings. The frequency of the MEG gamma response monotonically increased with motion velocity whereas power followed a bell-shape. In the second experiment, on a large group of children and adults, we found that despite drastic developmental changes in frequency and power of gamma oscillations, the relative suppression at high motion velocities was scaled to the same range of values across the life-span.

In light of animal and modeling studies, the modulation of gamma power and frequency at high stimulation intensities characterizes the capacity of inhibitory neurons to counterbalance increasing excitation in visual networks. Gamma suppression may thus provide a non-invasive measure of inhibitory-based gain control in the healthy and diseased brain.
Nucleolin internalizesBothrops asperLys49 phospholipase A2forming cell surface amyloid-like assemblies
Authors: Massimino Maria Lina , Simonato Morena , Spolaore Barbara , Franchin Cinzia , Arrigoni Giorgio , Marin Oriano , Monturiol-Gross Laura , Fernández Julián , Lomonte Bruno , Tonello Fiorella
Published: September 2017

Phospholipases A2(PLA2s) are a major component of snake venoms. Some of them cause severe muscle necrosis through a still unknown mechanism. Phospholipid hydrolysis is a possible explanation of their toxic action, but catalytic and toxic properties of PLA2s are not directly connected. In addition, viperid venoms contain PLA2-like proteins, which are very toxic even if they lack catalytic activity due to a critical mutation in position 49. Nucleolin, a main component of the nucleolus, is a disordered protein involved in many protein assembly and phase separation phenomena. In some circumstances nucleolin is exposed on the cell surface from where it is involved in the internalization of many ligands.

In this work we demonstrate thatBothrops aspermyotoxin II (Mt-II), a Lys49 PLA2-like toxin, interacts with, and is internalized in cells by nucleolin. The internalization process is functional to the toxicity of the protein, as both an antibody and an aptamer specific for nucleolin protect cells from intoxication. We identified central RRM and the C-terminal R/F-GG domain of nucleolin as the regions involved in the interaction with Mt-II. Finally we observed that Mt-II forms, on the cell surface, amyloid-like assemblies that colocalize with nucleolin and that can be involved in the activation of the internalization process. The presence, in the three dimensional structure of Mt-II and related PLA2homologues, of four exposed loops enriched in prion-like amino acid sequences reinforces this hypothesis.

Phospholipases A2| Lys49 myotoxins | nucleolin | amyloid-like | molecular assemblies

SIGNIFICANCE

The main finding of this work, the role of nucleolin asBothrops asperMt-II receptor, is a remarkable step forward in understanding the mechanism of action of cytotoxic PLA2s. It may suggest new strategies for anti-venom therapies and explain the anti-tumoral and anti-viral pharmacological action of snake PLA2s, since nucleolin is a receptor for many growth factors and virus.

The proposed internalization mechanism, via formation of molecular assemblies among Mt-II amyloid-like structures and other proteins, including nucleolin, can be of general validity. Cell surface molecular assemblies couldbepointsofselectionandconcentrationnotonlyofsnake,butalsoofmammaliansecretedPLA2s, proteins involved in different pathologies, and trigger the internalization pathway only when their molarity exceeds a threshold dose.
Development and Validation of a New Walking Pace Function Using Crowd-Sourced GPS Data
Authors: Pharoah Paul D.P.
Published: September 2017

There are several functions that hikers can use to predict walking time based on elevation change or slope of the ground. The most commonly used is the Naismith function that was first published over 100 years ago. The availability of GPS devices to record tracks now make it possible to evaluate the performance of walking time functions. Four data sources were used: 98 tracks downloaded from the Wikiloc web site; 55 tracks recorded by the author; 19 tracks recorded by the blogger Iron Hiker; and 20 tracks recorded by the blogger Hiking Guy. The ․gpx files were processed to generate segements of ~100m in length, with the associated segment duration and elevation change. The association between walking pace and elevation change was assessed in the Wikiloc data using linear spline regression. The performance of the linear spline function was then compared with the Naismith, Tobler and Laingmuir functions. The linear spline performed the best, but all four performed reasonably well. While the linear spline function could easily be programmed into the software of standard GPS devices, the Naismith function provides a simple-to-use rule-of-thumb for estimating walking time for a typical hike in the mountains.

Funding

None

Acknowledgements

I thank Chris Hazzard and Keith Wilson for sharing their hiking records and for helpful comments on the manuscript.

Disclosure of interests

The authors have no interest to disclose
A Cdk1 phosphomimic mutant of MCAK impairs microtubule end recognition
Authors: Belsham Hannah R. , Friel Claire T.
Published: September 2017

The microtubule depolymerising kinesin-13, MCAK, is phosphorylated at residue T537 by Cdk1. This is the only known phosphorylation site within MCAK’s motor domain. To understand the impact of phosphorylation by Cdk1 microtubule depolymerisation activity, we have investigated the molecular mechanism of the phosphomimic mutant T537E. This mutant significantly impairs microtubule depolymerisation activity and when transfected into cells causes metaphase arrest and misaligned chromosomes. We show that the molecular mechanism underlying the reduced depolymerisation activity of this phosphomimic mutant is an inability to recognise the microtubule end. The microtubule-end residence time is reduced relative to wild-type MCAK, whereas the lattice residence time is unchanged by the phosphomimic mutation. Further, the microtubule-end specific stimulation of ADP dissociation, characteristic of MCAK, is abolished by this mutation. Our data shows that T537E is unable to distinguish between the microtubule end and the microtubule lattice.
Integrative analysis of RNA polymerase II and transcriptional dynamics upon MYC activation
Authors: de Pretis Stefano , Kress Theresia R. , Morelli Marco J. , Sabò Arianna , Locarno Chiara , Verrecchia Alessandro , Doni Mirko , Campaner Stefano , Amati Bruno , Pelizzola Mattia
Published: September 2017

Overexpression of the MYC transcription factor causes its widespread interaction with regulatory elements in the genome but leads to the up- and down-regulation of discrete sets of genes. The molecular determinants of these selective transcriptional responses remain elusive. Here, we present an integrated time-course analysis of transcription and mRNA dynamics following MYC activation in proliferating mouse fibroblasts, based on chromatin immunoprecipitation, metabolic labeling of newly synthesized RNA, extensive sequencing, and mathematical modeling. Transcriptional activation correlated with the highest increases in MYC binding at promoters. Repression followed a reciprocal scenario, with the lowest gains in MYC binding. Altogether, the relative abundance (henceforth, “share”) of MYC at promoters was the strongest predictor of transcriptional responses in diverse cell types, predominating over MYC's association with the corepressor ZBTB17 (also known as MIZ1). MYC activation elicited immediate loading of RNA polymerase II (RNAPII) at activated promoters, followed by increases in pause-release, while repressed promoters showed opposite effects. Gains and losses in RNAPII loading were proportional to the changes in the MYC share, suggesting that repression by MYC may be partly indirect, owing to competition for limiting amounts of RNAPII. Secondary to the changes in RNAPII loading, the dynamics of elongation and pre-mRNA processing were also rapidly altered at MYC regulated genes, leading to the transient accumulation of partially or aberrantly processed mRNAs. Altogether, our results shed light on how overexpressed MYC alters the various phases of the RNAPII cycle and the resulting transcriptional response.
Does KFC sell rat? Analysis of tweets in the wake of a rumor outbreak
Authors: Pal Anjan , Chua Alton Y.K. , Goh Dion Hoe-Lian
Published: September 2017

Purpose

In the wake of a rumor outbreak, individuals exchange three types of messages: rumor messages, counter-rumor messages, and uncertainty-expressing messages. However, the properties of the three types of messages are relatively unknown particularly in the social media context. Hence, the purpose of this paper is to examine these three types of messages posted on social media in the wake of a rumor outbreak.

Design/methodology/approach

Data included tweets posted after the outbreak of a rumor that wrongly accused the fast food chain Kentucky Fried Chicken (KFC) for selling rats instead of chicken. Using a deductive approach, codes were derived via content analysis on the tweets. Volume and exposure of tweets were also examined.

Findings

Counter-rumor tweets (52 percent) outnumbered rumors tweets (32 percent) and uncertainty-expressing tweets (16 percent). Emotions and personal involvement were abundant in rumor tweets. Expressions of credence and references to URLs were high in counter-rumor tweets. Social ties were found widely in uncertainty-expressing tweets. The high volume and exposure of counter-rumor tweets compared with those of either rumor tweets or uncertainty-expressing tweets highlight the potential of counter-rumors to mitigate rumors.

Originality/value

This research ventures into a relatively unexplored territory by concurrently examining rumor messages, counter-rumor messages and uncertainty-expressing messages in the wake of a rumor outbreak. It reveals that counter-rumor messages have the potential to mitigate rumors on social media.
Spirituality at work: enhancing levels of employee engagement
Authors: Devendhiran Sangeetha , Wesley J. Reeves
Published: September 2017

Purpose

The purpose of the paper is to highlight the concept of workplace spirituality, its benefits, importance in organization, and the strategies to implement workplace spirituality to enhance employee engagement in the organization.

Design/methodology/approach

Viewpoint paper.

Findings

This paper suggests that workplace spirituality will improve the level of engagement of employees.

Originality/value

This paper provides various strategies of workplace spirituality. This will help the organization to implement it in the work setting.
Numerical simulation for magnetohydrodynamic three dimensional flow of Casson nanofluid with convective boundary conditions and thermal radiation
Authors: Gupta Sumit , Sharma Kalpna
Published: September 2017

Purpose

The purpose of this study is to analyze magnetohydrodynamic three-dimensional flow of Casson nanofluid over a stretching sheet in presence of thermophoresis and Brownian motion effects. In contrast, the convective surface boundary conditions with the effects of radiation are applied.

Design/methodology/approach

The governing partial differential equations are transformed into highly nonlinear coupled ordinary differential equations consisting of the momentum, energy and nanoparticle concentration via suitable similarity transformations, which are then solved the using optimal homotopy analysis method (OHAM) a Mathematica Package BVPh2.0.

Findings

The influence of emerging physical flow parameters on fluid velocity component, temperature distribution and nanoparticle concentration are discussed in detail. Also, an OHAM solution demonstrates very good correlation with those obtained in the previously published results. It is noticed that OHAM can overcome the earlier restriction, assumptions and limitation of traditional perturbation method. The main advantage of this method is that OHAM can be applied directly to nonlinear differential equations without using linearization and round-off errors, and therefore, it cannot be affected by error associated to discretization.

Originality/value

Here the approximate solutions are compared with the numerical results published in earlier work.
The comparison of two reliable methods for the accurate solution of fractional Fisher type equation
Authors: Saha Ray S.
Published: September 2017

Purpose

The purpose of this paper is the comparative analysis of Haar Wavelet Method and Optimal Homotopy Asymptotic Method for fractional Fisher type equation. In this paper, two reliable techniques, Haar wavelet method and optimal homotopy asymptotic method (OHAM), have been presented. The Haar wavelet method is an efficient numerical method for the numerical solution of fractional order partial differential equation like the Fisher type. The approximate solutions of the fractional Fisher-type equation are compared with those of OHAM and with the exact solutions. Comparisons between the obtained solutions with the exact solutions exhibit that both the featured methods are effective and efficient in solving nonlinear problems. However, the results indicate that OHAM provides more accurate value than the Haar wavelet method.

Design/methodology/approach

Comparisons between the solutions obtained by the Haar wavelet method and OHAM with the exact solutions exhibit that both featured methods are effective and efficient in solving nonlinear problems.

Findings

The comparative results indicate that OHAM provides a more accurate value than the Haar wavelet method.

Originality/value

In this paper, two reliable techniques, the Haar wavelet method and OHAM, have been proposed for solving nonlinear fractional partial differential equation, i.e. fractional Fisher-type equation. The proposed novel methods are well suited for only nonlinear fractional partial differential equations. It also exhibits that the proposed method is a very efficient and powerful technique in finding the solutions for the nonlinear time fractional differential equations. The main significance of the proposed method is that it requires less amount of computational overhead in comparison to other numerical and analytical approximate methods. The application of the proposed methods for the solutions of time fractional Fisher-type equations satisfactorily justifies its simplicity and efficiency.
Solving imprecisely defined vibration equation of large membranes
Authors: Tapaswini Smita , Mu Chunlai , Behera Diptiranjan , Chakraverty Snehashish
Published: September 2017

Purpose

Vibration of large membranes has great utility in engineering application such as in important parts of drums, pumps, microphones, telephones and other devices. So, to obtain a numerical solution of this type of problems is necessary and important. In general, in existing approaches, involved parameters and variables are defined exactly. Whereas in actual practice, it may contain uncertainty owing to error in observations, maintenance-induced error, etc. So, the main purpose of this paper is to solve this important problem numerically under fuzzy and interval uncertainty to have an uncertain solution and to study its behaviour.

Design/methodology/approach

In this study, the authors have considered a new approach is known as double parametric form of fuzzy number to model uncertain parameters. Along with this a semianalytical approach, i.e. variational iteration method, has been used to obtain uncertain bounds of the solution.

Findings

The variational iteration method has been successfully implemented along with the double parametric form of fuzzy number to find the uncertain solution of the vibration equation of a large membrane. The advantage of this approach is that the solution can be written in a power series or a compact form. Also, this method converges rapidly to obtain an accurate solution. Various cases depending on the functional value involved in the initial conditions have been studied and the behaviour has been analysed. Applying the double parametric form reduces the computational cost without separating the fuzzy equation into coupled differential equations as done in traditional approaches.

Originality/value

The vibration equation of large membranes has been solved under fuzzy and interval uncertainty. Uncertainties have been considered in the initial conditions. New approaches, i.e. variational iteration method along with the double parametric form, have been applied to solve the vibration equation of large membranes.
Particle shape, thermal radiations, viscous dissipation and joule heating effects on flow of magneto-nanofluid in a rotating system
Authors: Khan Umar , Abbasi Adnan , Ahmed Naveed , Mohyud-Din Syed Tauseef
Published: September 2017

Purpose

The purpose of this paper is to explore the impact of thermal radiation, viscous dissipation and Joule heating effects on the flow of a magneto-nanofluid between two horizontally placed plates. Three distinct shapes of nanoparticles in a base fluid (water) are considered to compose the nanofluid.

Design/methodology/approach

Introducing feasible similarity variables, the flow model is transformed into a nonlinear and coupled system of ordinary differential equations. The consequent system is solved by using homotopy analysis method.

Findings

Furthermore, the influence of embedded parameters on velocity and temperature profiles is highlighted graphically. The same is done for showing the variations in skin friction coefficient and local rate of heat transfer. Under certain conditions, present results compared with already existing results in the literature. Some main findings are pinpointed in the last section before the bibliography. From presented work, it is analyzed that the velocity field along y-axis and x-axis are increasing and decreasing functions of suction/injection parameter. The velocity of the fluid starts increases for Reynolds number and declines for volumetric fraction of the nanoparticles. Significant variations in angular velocity are observed for volumetric fraction and Reynolds number, respectively. Thermal field increases rapidly for brick-shaped nanoparticles, and for platelet-shaped nanoparticles, it decreases rapidly. Local rate of heat transfer increases for radiation and Reynolds number and starts decreasing for Eckert number.

Originality/value

The study presented is original and has not been submitted to any other journal for the publication purpose. The contents are original and proper references have been provided wherever applicable.
Hydromagneto quadratic natural convection on a lid driven square cavity with isothermal and non-isothermal bottom wall
Authors: K. Venkatadri , S. Gouse Mohiddin , M. Suryanarayana Reddy
Published: September 2017

Purpose

This paper aims to focus on linear and non-linear convection in a lid-driven square cavity with isothermal and non-isothermal bottom surface.

Design/methodology/approach

It is assumed that the top moving wall is adiabatic and the bottom wall is heated in two modes, and the rest of the walls are maintained at uniform cold temperature. The coupled governing non-linear partial differential equations are solved numerically with MAC algorithm for conducting a parametric study with uniform and non-uniform temperature bottom wall.

Findings

The numerical results are depicted in the form of streamlines, temperature contours and variation of local Nusselt number. The local Nusselt number at the bottom wall of the cavity increases in presence of non-linear temperature parameter as compared with linear temperature parameter and heat transfer reduces with increasing of Ha for uniform and non-uniform heating of bottom wall.

Research limitations/implications

The numerical investigation is conducted for unsteady, two-dimensional natural convective flow in a square cavity. An extension of the present study with the effect of inclination of cavity, wavy walls and triangular cavity will be the interest of future work.

Originality/value

This work studies the effect of magnetic field in the presence of linear convection and non-linear convection. This study might be useful to cooling of electronic components, alloy casting, crystal growth and fusion reactors, etc.
Evaluating planting date and variety management strategies for adapting winter wheat to climate change impacts in arid regions
Authors: Hesam Arefi Iman , Saffari Mehri , Moradi Rooholla
Published: September 2017

Purpose

The purpose of this study is to simulate the climate change impacts on winter wheat production and evaluate the possibilities of using various varieties and shifting planting date as two climate change adaptation strategies in Kerman Province, Iran.

Design/methodology/approach

Two types of global circulation model and three scenarios for three periods were used. Daily climatic parameters were generated by LARS-WG (Long Ashton Research Station-Weather Generator). The CERES-wheat model was used to simulate future winter wheat growth, development and production.

Findings

The results showed that CO2had no effect on the phenology of winter wheat, and the negative impact of temperature on the grain yield was higher than the positive effect of CO2enrichment. The length of the reproductive growth period of the winter wheat was significantly shortened as affected by the negative impacts of rise in temperature. The simulated results indicated that the grain yield of common (medium maturing) variety of winter wheat will decline, ranging from −0.27 to −18.71 per cent according to future climate changes. Adaptation strategies showed that the early maturing variety had a higher and more stable grain yield under climate change conditions than medium and delayed maturing varieties. Earlier planting date (20 October) increased wheat grain yield under future climatic conditions than common (November 5) planting date. In reverse, later planting (November 20) would accelerate harmful effects of climate change on wheat grain yield.

Originality/value

The results highlighted the potential of early maturing variety and early planting date as the appropriate agronomical approaches for mitigating harmful impacts of climate change on winter wheat production in arid regions.