bluuebunny/crossref_metadata_2025 huggingface dataset:
How Do Transcatheter Heart Valves Fit in Mitral Annuloplasty Rings and Which Combination Can be Recommended?
Authors: Ostovar Roya , Kuehnel Ralf-Uwe , Erb Michael , Hartrumpf Martin , Claus Thomas , Haase Robert , Albes Johannes M.
Published: May 2018

Background Transcatheter heart valve (THV) as valve-in-ring is increasingly used in the mitral position. Semi-rigid rings may serve as a more appropriate scaffold for proper anchoring of a THV as they may change from their oval to a round shape thereby fitting to the implanted THV.

Methods One rigid and five semi-rigid rings of four manufacturers, Edwards Physio I and II, Sorin 3D Memo, Medtronic Simulus, and St. Jude Medical (SJM) Saddle and SJM Sequin, with sizes 28 to 36 mm and Edwards Sapien III THV 23, 26, and 29 mm were used. Preevaluation comprised insertion/inflation of the THV into the ring and visual inspection for the paravalvular gap ≥ 4 mm2. Only valves not showing paravalvular gap were then submitted to hemodynamic evaluation with a pulse duplicator. Cusp movement was assessed with a high-speed-camera. Mean transvalvular gradients (TVGs) were measured.

Results SJM Saddle ring of all sizes and SJM Sequin ring 34 showed marked gaps combined with all THV sizes, thus not undergoing hemodynamic testing. It was further shown that ring sizes ≥ 36 mm did not allow for a proper fit of even the largest THV into the ring of all the manufacturers and were consequently not hemodynamically evaluated. The 23 mm THV was too small for any ring size. The lowest gradients were achieved with the 26 mm THV in 30 and 32 mm and the 29 mm THV in 32 and 34 mm rings.

Conclusion Not all currently available annuloplasty rings are ideal scaffolds for THV placement. It appears that a more proper fit can be achieved with semi-rigid rings than with rigid ones. Note that 23 mm THV appeared to be too small for an adequate anchoring in even the smallest available ring. Thus, 26 mm as well as 29 mm THV fit properly in ring sizes between 28 and 34 mm. Surgeons may consider to choose from those ring brands and sizes which allow for good placement of a THV in view of possible valve degeneration in the later course.
Comparable efficacy of endoscopic transpapillary gallbladder drainage and percutaneous transhepatic gallbladder drainage in acute cholecystitis
Authors: Iino Chikara , Shimoyama Tadashi , Igarashi Takasato , Aihara Tomoyuki , Ishii Kentaro , Sakamoto Juichi , Tono Hiroshi , Fukuda Shinsaku
Published: May 2018

Background and study aims Although endoscopic transpapillary gallbladder drainage (ETGBD) is reportedly useful in patients who have acute cholecystitis, its efficacy has not been compared to that of percutaneous transhepatic gallbladder drainage (PTGBD). We retrospectively compared the efficacy and safety of ETGBD and PTGBD in patients with acute cholecystitis.

Patients and methods We studied 75 patients who required gallbladder drainage for acute cholecystitis between January 2014 and December 2016. Using propensity score matching analysis, we compared the clinical efficacy and length of hospitalization in patients successfully treated with ETGBD and PTGBD. Moreover, we assessed the predictive factors for hospitalization period < 30 days using multivariate analysis.

Results ETGBD and PTGBD were successfully performed in 33 patients (77 %) and 42 patients (100 %) (P < 0.001). Twenty-seven matched pairs were obtained after propensity score matching analysis. No significant differences were observed between patients treated with ETGBD and those treated with PTGBD with respect to improvement in white blood cell count and serum C-reactive protein level. The length of hospitalization in patients treated with ETGBD was significantly shorter than in those treated with PTGBD regardless of the need for surgery. Multivariate logistic regression analysis revealed ETGBD (odds ratio, 7.07; 95 % confidence interval 2.22 – 22.46) and surgery (odds ratio 0.26; 95 % confidence interval 0.09 – 0.79) as independent factors associated with hospitalization period. There were no significant differences in occurrence of complications in ETGBD and PTGBD procedure.

Conclusions ETGBD was shown to be as useful as PTGBD for treatment of acute cholecystitis and was associated with shorter hospitalization period. ETGBD can be an alternative treatment option for acute cholecystitis at times when PTGBD is not possible.
Approximate isotropic cloak for the Maxwell equations
Authors: Ghosh Tuhin , Tarikere Ashwin
Published: May 2018

We construct a regular isotropic approximate cloak for the Maxwell system of equations. The method of transformation optics has enabled the design of electromagnetic parameters that cloak a region from external observation. However, these constructions are singular and anisotropic, making practical implementation difficult. Thus, regular approximations to these cloaks have been constructed that cloak a given region to any desired degree of accuracy. In this paper, we show how to construct isotropic approximations to these regularized cloaks using homogenization techniques so that one obtains cloaking of arbitrary accuracy with regular and isotropic parameters.
Controllability of symmetric spin networks
Authors: Albertini Francesca , D’Alessandro Domenico
Published: May 2018

We consider a network of n spin 12 systems which are pairwise interacting via Ising interaction and are controlled by the same electro-magnetic control field. Such a system presents symmetries since the Hamiltonian is unchanged if we permute two spins. This prevents full (operator) controllability, in that not every unitary evolution can be obtained. We prove however that controllability is verified if we restrict ourselves to unitary evolutions which preserve the above permutation invariance. For low dimensional cases, n = 2 and n = 3, we provide an analysis of the Lie group of available evolutions and give explicit control laws to transfer between two arbitrary permutation invariant states. This class of states includes highly entangled states such as Greenberger-Horne-Zeilinger (GHZ) states and W states, which are of interest in quantum information.
SVM-based multisensor data fusion for phase concentration measurement in biomass-coal co-combustion
Authors: Wang Xiaoxin , Hu Hongli , Jia Huiqin , Tang Kaihao
Published: May 2018

In this paper, the electrical method combines the electrostatic sensor and capacitance sensor to measure the phase concentration of pulverized coal/biomass/air three-phase flow through data fusion technology. In order to eliminate the effects of flow regimes and improve the accuracy of the phase concentration measurement, the mel frequency cepstrum coefficient features extracted from electrostatic signals are used to train the Continuous Gaussian Mixture Hidden Markov Model (CGHMM) for flow regime identification. Support Vector Machine (SVM) is introduced to establish the concentration information fusion model under identified flow regimes. The CGHMM models and SVM models are transplanted on digital signal processing (DSP) to realize on-line accurate measurement. The DSP flow regime identification time is 1.4 ms, and the concentration predict time is 164 μs, which can fully meet the real-time requirement. The average absolute value of the relative error of the pulverized coal is about 1.5% and that of the biomass is about 2.2%.
Helix structure for low frequency acoustic energy harvesting
Authors: Yuan Ming , Cao Ziping , Luo Jun , Pang Zongqiang
Published: May 2018

In this study, a novel helix acoustic resonator is proposed to realize acoustic energy harvesting (AEH). Compared with the traditional acoustic resonators, the proposed structure occupies a small volume and is suitable for the low frequency range. At a specific incident frequency, the mechanical component of the AEH device can be intensely excited and the bonded piezoelectric patch is utilized to convert the strain energy into electrical energy. Analytical studies are carried out to disclose the acoustic resonant system properties. Meanwhile, the pure acoustic and coupled vibro-acoustic properties of the proposed device are analyzed via the finite element method. The major part of the AEH device is fabricated via 3D printing for experimental study, which is favored for rapid prototyping. At acoustic resonance frequency 175 Hz, 100 dB sound pressure level excitation working condition, the measured experimental data show that the harvested power can be up to 7.3 μW.
A digital, constant-frequency pulsed phase-locked-loop instrument for real-time, absolute ultrasonic phase measurements
Authors: Haldren H. A. , Perey D. F. , Yost W. T. , Cramer K. E. , Gupta M. C.
Published: May 2018

A digitally controlled instrument for conducting single-frequency and swept-frequency ultrasonic phase measurements has been developed based on a constant-frequency pulsed phase-locked-loop (CFPPLL) design. This instrument uses a pair of direct digital synthesizers to generate an ultrasonically transceived tone-burst and an internal reference wave for phase comparison. Real-time, constant-frequency phase tracking in an interrogated specimen is possible with a resolution of 0.000 38 rad (0.022°), and swept-frequency phase measurements can be obtained. Using phase measurements, an absolute thickness in borosilicate glass is presented to show the instrument’s efficacy, and these results are compared to conventional ultrasonic pulse-echo time-of-flight (ToF) measurements. The newly developed instrument predicted the thickness with a mean error of −0.04 μm and a standard deviation of error of 1.35 μm. Additionally, the CFPPLL instrument shows a lower measured phase error in the absence of changing temperature and couplant thickness than high-resolution cross-correlation ToF measurements at a similar signal-to-noise ratio. By showing higher accuracy and precision than conventional pulse-echo ToF measurements and lower phase errors than cross-correlation ToF measurements, the new digitally controlled CFPPLL instrument provides high-resolution absolute ultrasonic velocity or path-length measurements in solids or liquids, as well as tracking of material property changes with high sensitivity. The ability to obtain absolute phase measurements allows for many new applications than possible with previous ultrasonic pulsed phase-locked loop instruments. In addition to improved resolution, swept-frequency phase measurements add useful capability in measuring properties of layered structures, such as bonded joints, or materials which exhibit non-linear frequency-dependent behavior, such as dispersive media.
Shock response of poly[methyl methacrylate] (PMMA) measured with embedded electromagnetic gauges
Authors: Lacina David , Neel Christopher , Dattelbaum Dana
Published: May 2018

The shock response of poly[methyl methacrylate] (PMMA) acquired from two providers, Spartech and Rohm & Haas, has been measured to investigate the shock response variations related to material pedigree. These measurements have also been used to examine the effects of viscoelasticity on Spartech PMMA. Measurements of the Hugoniot curves, release wave speeds, and index of refraction have been acquired up to previously unexplored stresses, ∼10.7 GPa, for Spartech PMMA. In-situ, time-resolved particle velocity wave profiles, as a function of time and depth, were obtained using twelve separate electromagnetic gauge elements embedded at different depths in the PMMA. A comparison of the new data to the shock response data for Rohm and Haas PMMA, used as a “standard” material in shock compression studies, shows that there are no significant differences in shock response for the two materials. From the index of refraction measurements, the apparent particle velocity correction for a PMMA window exhibits an interesting oscillation, increasing at up = 0.3 km/s after decreasing up to that point. The results are generalized into guidelines for sourcing PMMA for use in shock studies.
Characteristics of soft x-ray and extreme ultraviolet (XUV) emission from laser-produced highly charged rhodium ions
Authors: Barte Ellie Floyd , Hara Hiroyuki , Tamura Toshiki , Gisuji Takuya , Chen When-Bo , Lokasani Ragava , Hatano Tadashi , Ejima Takeo , Jiang Weihua , Suzuki Chihiro , Li Bowen , Dunne Padraig , O'Sullivan Gerry , Sasaki Akira , Higashiguchi Takeshi , Limpouch Jiří
Published: May 2018

We have characterized the soft x-ray and extreme ultraviolet (XUV) emission of rhodium (Rh) plasmas produced using dual pulse irradiation by 150-ps or 6-ns pre-pulses, followed by a 150-ps main pulse. We have studied the emission enhancement dependence on the inter-pulse time separation and found it to be very significant for time separations less than 10 ns between the two laser pulses when using 6-ns pre-pulses. The behavior using a 150-ps pre-pulse was consistent with such plasmas displaying only weak self-absorption effects in the expanding plasma. The results demonstrate the advantage of using dual pulse irradiation to produce the brighter plasmas required for XUV applications.
Tuning the nanostructures and optical properties of undoped and N-doped ZnO by supercritical fluid treatment
Authors: Li Yaping , Wang Hui-Qiong , Chu Tian-Jian , Li Yu-Chiuan , Li Xiaojun , Liao Xiaxia , Wang Xiaodan , Zhou Hua , Kang Junyong , Chang Kuan-Chang , Chang Ting-Chang , Tsai Tsung-Ming , Zheng Jin-Cheng
Published: May 2018

Treatment of ZnO films in a supercritical fluid (SCF) has been reported to improve the performance of devices in which the treated ZnO films are incorporated; however, the mechanism of this improvement remains unclear. In this paper, we study the transformation of the surface morphologies and emission properties of ZnO films before and after SCF treatment, establishing the relationship between the treated and untreated structures and thereby enabling tuning of the catalytic or opto-electronic performance of ZnO films or ZnO-film-based devices. Both undoped and N-doped ZnO nanostructures generated by SCF treatment of films are investigated using techniques to characterize their surface morphology (scanning electron microscopy (SEM) and atomic force microscopy (AFM)) as well as room-temperature photoluminescence (RT-PL) spectroscopy. The water-mixed supercritical CO2 (W-SCCO2) technology was found to form nanostructures in ZnO films through a self-catalyzed process enabled by the Zn-rich conditions in the ZnO films. The W-SCCO2 was also found to promote the inhibition of defect luminescence by introducing -OH groups onto the films. Two models are proposed to explain the effects of the treatment with W-SCCO2. This work demonstrates that the W-SCCO2 technology can be used as an effective tool for the nanodesign and property enhancement of functional metal oxides.
Ferromagnetic Josephson junctions based on epitaxial NbN/Ni60Cu40/NbN trilayer
Authors: Li Feng , Zhang Hui , Zhang Lu , Peng Wei , Wang Zhen
Published: May 2018

We fabricated and characterized a weakly coupled magnetic Josephson junction based on epitaxial NbN/Ni60Cu40/NbN trilayer heterostructures on single crystal MgO (100) substrates. X-ray diffraction and cross-sectional scanning transmission electron microscopy were used to verify the epitaxial growth of NbN/Ni60Cu40/NbN trilayer, while the ferromagnetic properties of NiCu on NbN film were recorded by plotting the magnetization as a function of both the temperature and the magnetic field strength. The NbN/Ni60Cu40/NbN junctions demonstrated typical Josephson effect with a nonlinear overdamped current–voltage characteristic and a characteristic voltage of 9.1 μV. The magnetic field dependence of the junction critical current showed a nearly ideal Fraunhofer-like pattern with a magnetic field shift of about 12 Oe due to the remanent magnetization of Ni60Cu40 layer.
The effect of the dietary protein restriction and re-feeding on the content of leptin, IGF-I and urea nitrogen in the blood plasma and growth performance in pigs
Authors: Brestenský M. , Nitrayová S. , Sirotkin A. V. , Patráš P. , Heger J.
Published: May 2018

The aim of the present study was to examine the effect of the dietary protein restriction on the plasma concentrations of leptin, insulin-like growth factor (IGF-I), blood urea nitrogen (BUN) and growth performance in growing pigs. A total of 12 gilts were divided into experimental (ET) and control (CT) treatments. After the 14-day dietary restriction period during which the ET fed a low-protein diet (LPD, 5% of crude protein) and the CT fed a standard diet (SD, 16% of crude protein) the second 14-day re-feeding period followed, in which LPD was replaced by a SD that was fed by the both treatments. During the dietary protein restriction reduced (P < 0.05) N intake, average daily gain (ADG), concentration of BUN and tendency (P = 0.084) to the lower IGF-I in ET compared with CT were observed. Feed to gain ratio was greater (P < 0.05) in ET. During the subsequent re-feeding period, there was a tendency to the greater daily feed intake (P = 0.068) and N intake (P = 0.070), greater (P < 0.05) ADG, BUN and plasma leptin but no IGF-I in ET. These observations suggest that dietary protein restriction promotes body growth in pigs, which is associated with increase in blood leptin and BUN level in ET during the re-feeding, indicating that the increased ADG can be due to increased fat deposition but not of protein synthesis.
A rapid method for the analysis of perfluorinated alkyl substances in serum by hybrid solid-phase extraction
Authors: Honda Masato , Robinson Morgan , Kannan Kurunthachalam
Published: May 2018

Environmental contextAlthough the environmental occurrence of perfluoroalkyl substances was first reported almost 20 years ago, there are continuing concerns about human exposure to these potentially toxic chemicals. Such concerns have necessitated the development of reliable methods for rapid determination of perfluoroalkyl substances in human serum. This article describes a rapid and sensitive analytical method suitable for monitoring human exposure to perfluoroalkyl substances. AbstractA method for the analysis of 13 perfluorinated alkyl substances (PFASs) in human serum was developed based on hybrid solid-phase extraction (hybrid-SPE) and ultrahigh-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS). Serum PFASs were extracted using hybrid-SPE-phospholipid cartridge after precipitating proteins and other endogenous biological interferences with 1 % ammonium formate in methanol. The average intra-day accuracy (measured as percent recoveries from fortified samples) and precision of the method (measured as relative standard deviation [RSD, %] between analyses) were 88.7–117 % and 1.0–13.4 %, respectively. The average inter-day precision was 2.8–6.9 %. The method was sensitive, with limits of quantification (LOQs) in the range of 0.05 to 0.09 ng mL−1 for all 13 PFASs. The applicability of this method was tested by analysing serum-certified standard reference material and proficiency test samples. In an hour, 100 samples can be processed by hybrid-SPE, and the instrumental run time is 5 min per sample. The developed method is rapid, inexpensive, accurate, precise, and extremely sensitive for the analysis of PFASs in human serum.
Untangling Lepidocyrtus (Collembola, Entomobryidae): new molecular data shed light on the relationships of the European groups
Authors: Mateos Eduardo , Escuer Paula , Buşmachiu Galina , Riutort Marta , Álvarez-Presas Marta
Published: May 2018

European Lepidocyrtus species are usually grouped into five species-groups within two subgenera, Lepidocyrtus s.s. and Lanocyrtus, defined by the distribution of scale covering and dorsal head and body macrochaetotaxy. The discovery of several Lepidocyrtus populations with morphological characters intermediate between two species-groups suggested the need for the present study to test whether molecular data provide support to these groups. The morphology and gene sequences of 110 specimens belonging to 19 species of European Lepidocyrtus have been studied. Our molecular results are congruent with the distribution of the European species into the five groups established in the literature on the basis of morphological characters, but also indicated that subgenus Lanocyrtus is paraphyletic while subgenus Lepidocyrtus s.s. is monophyletic. A new species, Lepidocyrtus intermedius, is described, and a redefinition of European species-groups is proposed based on chaetotaxy.
Experimental Tensile Strength Analysis of Woven-Glass/Epoxy Composite Plates with Central Circular Hole
Authors: K. Hadi Bambang , K. Rofa Bima
Published: May 2018

The use of composite materials in aerospace engineering, as well as in maritime structure has increased significantly during the recent years. The extensive use of composite materials in industrial applications should make composite structural engineers and scientists more aware of the advantage and disadvantage of this material and provide them with necessary data and certification process. One of the problems in composite structures is the existence of hole. Hole can not be avoided in actual structures, since it may be the necessity of providing access for maintenance or due to impact damage. The presence of hole will weaken the structures. Therefore, in this paper, the effect of hole on the strength of glass-woven/epoxy composite will be discussed. Extensive tests have been carried out to study the effect of hole-diameter on the tensile strengths of these specimens. The results showed that the bigger the hole-diameter compared to the width of the specimens has weakened the structures further, as expected. Further study should be carried in the future to model it with the finite element and theoretical analysis precisely.
Three Point Bending of Top-Hat Stiffened Chopped Short Fibre Ramie/HDPE Thermoplastic Composite Beam
Authors: K. Hadi Bambang , S. Nuril Yogie
Published: May 2018

The use of natural fibre and thermoplastic matrices in composite materials increased significantly during the last decade especially in the automotive industries. Ramie is one of these potential natural fibres. In this paper, a three point bending of top-hat beam made of ramie/HDPE (High-Density-Polyethylene) composites was performed. Top-hat stiffened structures were common structures found in the aerospace industries. Nevertheless, these structures are beginning to be applied in automotive structures in the forms of chassis and bumpers. The ramie/HDPE composite was manufactured using hot-press technique. The temperature was set to be 135°C and the pressure was 6 bars. Chopped short ramie fibre was used, due to good drape ability characteristics. The experiments showed that the beams produced a large non-linearity. Linear Finite Element Analysis was carried out to be compared with the experimental data. The differences are reasonable.
Madden-Julian Oscillation (MJO) Signal over Kototabang, West Sumatera Based on the Mini Automatic Weather Station (MAWS) Data Analysis Using the Wavelet Technique
Authors: Hermawan E
Published: May 2018

This study is mainly concerned an application of Mini Automatic Weather Station (MAWS) at Kototabang, West Sumatera nearby the location of an Equatorial Atmosphere Radar (EAR) side. We are interest to use this data to investigate the propagation of the Madden-Julian Oscillation (MJO). We examined of daily MAWS data for 3 years observations started from January 2001 to Mei 2004. By applying wavelet analysis, we found the MJO at Kototabang have 32 days oscillations as shown in Fig.1 below. In this study, we concentrate just for local mechanis only. We will show in this paper that at the phase of the MJO with a dipole structure to the convection anomalies, there is enhanced tropical convection over the eastern Indian Ocean and reduced convection over the western Pacific. Over the equatorial western Indian Ocean, the equatorial Rossby wave response to the west of the enhanced convection includes a region of anomalous surface divergence associated with the anomalous surface westerlies and pressure ridge. This tends to suppress ascent in the boundary layer and shuts off the deep convection, eventually leading to a convective anomaly of the opposite sign. Over the Indonesian sector, the equatorial Kelvin wave response to the east of the enhanced convection includes a region of anomalous surface convergence into the anomalous equatorial surface easterlies and pressure trough, which will tend to favour convection in this region. The Indonesian sector is also influenced by an equatorial Rossby wave response (of opposite sign) to the west of the reduced convection over the western Pacific, which also has a region of anomalous surface convergence associated with its anomalous equatorial surface easterlies and pressure trough. Hence, convective anomalies of either sign tend to erode themselves from the west and initiate a convective anomaly of opposite sign via their equatorial Rossby wave response, and expand to the east via their equatorial Kelvin wave response.
Mechanism of action vasodilation Annona muricata L. leaves extract mediated vascular smooth muscles
Authors: Ismail S , Hayati N , Rahmawati N
Published: May 2018

Annona muricata L. leaves (AML) is used as ethnomedicine by the Dayak Abai ethnicity in North Kalimantan for its already known use to reduce blood pressure. However, the mechanism of action in the vessel is still poorly understood. Aim study to prove the mechanism of action of AML in blood vessels. AML was extracted with a maceration technique using ethanol solvent. Mechanism of action test was performed with isolated rat aortic with endothelium (endo-intact) and without endothelium (endo-denuded). AML extract intervention on rats aorta with endo-intact and endo-denuded can induction vasodilatation activity. Increasing AML extract concentration can improve decrease vasodilatation activity on isolated rats aortic with endo-intact compared to endo-denuded, it means that endothelium can weaken vasodilatation activity of aorta mediated by vascular smooth muscle after the extract was given.
Nonsurgical Medical Penile Girth Augmentation: A Retrospective Study of Psychological and Psychosexual Outcomes
Authors: Sharp Gemma , Oates Jayson
Published: May 2018

Background

Although interest in penile augmentation procedures is increasing, there is a significant lack of research into the psychological and psychosexual outcomes of these procedures.

Objectives

To investigate the psychological and psychosexual outcomes of nonsurgical medical penile girth augmentation.

Methods

This retrospective study involved a mixed method approach. Twenty-five men who had undergone a nonsurgical medical penile girth augmentation between 1 and 12 months prior (mean, 6.6 months) completed an online questionnaire containing measures of procedure motivation, procedure satisfaction, genital self-image, penile-focused body dysmorphic disorder symptoms, self-esteem, and sexual relationship satisfaction. Six of these men elected to complete in-depth one-to-one semi-structured phone interviews to further explore the psychological impacts of the procedure.

Results

In the online questionnaire, most men were satisfied with their penile size, appearance, and function after penile girth augmentation. The men also reported statistically significant improvements in their genital self-image (P < 0.001) and self-esteem (P = 0.008), and a reduction in penile-focused body dysmorphic disorder symptoms (P = 0.002) at the time of completing the questionnaire compared to recalled pre-procedural levels. The in-depth interviews yielded 3 themes surrounding penile augmentation outcomes: (1) high satisfaction with increased penis girth; (2) increased self-confidence, particularly in situations in which the penis would be seen, such as a locker room; and (3) increased sexual confidence, but some mixed impacts on sexual relationships.

Conclusions

Most men appear to be satisfied with their nonsurgical medical penile girth augmentation results, and they also seem to experience improvements in their overall self-esteem.

Level of Evidence: 4
Cell-Specific Loss of SNAP25 from Cortical Projection Neurons Allows Normal Development but Causes Subsequent Neurodegeneration
Authors: Hoerder-Suabedissen Anna , Korrell Kim V , Hayashi Shuichi , Jeans Alexander , Ramirez Denise M O , Grant Eleanor , Christian Helen C , Kavalali Ege T , Wilson Michael C , Molnár Zoltán
Published: May 2018

Synaptosomal associated protein 25 kDa (SNAP25) is an essential component of the SNARE complex regulating synaptic vesicle fusion. SNAP25 deficiency has been implicated in a variety of cognitive disorders. We ablated SNAP25 from selected neuronal populations by generating a transgenic mouse (B6-Snap25tm3mcw (Snap25-flox)) with LoxP sites flanking exon5a/5b. In the presence of Cre-recombinase, Snap25-flox is recombined to a truncated transcript. Evoked synaptic vesicle release is severely reduced in Snap25 conditional knockout (cKO) neurons as shown by live cell imaging of synaptic vesicle fusion and whole cell patch clamp recordings in cultured hippocampal neurons. We studied Snap25 cKO in subsets of cortical projection neurons in vivo (L5—Rbp4-Cre; L6—Ntsr1-Cre; L6b—Drd1a-Cre). cKO neurons develop normal axonal projections, but axons are not maintained appropriately, showing signs of swelling, fragmentation and eventually complete absence. Onset and progression of degeneration are dependent on the neuron type, with L5 cells showing the earliest and most severe axonal loss. Ultrastructural examination revealed that cKO neurites contain autophagosome/lysosome-like structures. Markers of inflammation such as Iba1 and lipofuscin are increased only in adult cKO cortex. Snap25 cKO can provide a model to study genetic interactions with environmental influences in several disorders.
The history and promise of holism in health promotion
Authors: Michaelson Valerie , Pickett William , Davison Colleen
Published: May 2018

Holism is an ancient theme concept that has resurfaced in recent literature, and that requires informed and intentional use in order to preserve its utility. This paper provides a historical and conceptual reintroduction of the notion of holism as it relates to health, with the hopes of informing the term's use in public health discourse. It also addresses the challenges that a lack of conceptual clarity about holistic health imposes on public health and health promotion discussions. It describes how the use and conceptualizations of holism are shifting in health promotion and argues that failing to accurately define and delineate its scope risks diluting its utility for future health promotion applications. We address these two problems, and build an argument for a rediscovery of the theory of holism in public health and health promotion, globally.
Determinants of Gammaherpesvirus Shedding in Saliva Among Ugandan Children and Their Mothers
Authors: Newton Robert , Labo Nazzarena , Wakeham Katie , Marshall Vickie , Roshan Romin , Nalwoga Angela , Sebina Ismail , Muhangi Lawrence , Webb Emily L , Miley Wendell , Rochford Rosemary , Elliott Alison M , Whitby Denise
Published: May 2018

Among Ugandan mother-child pairs, Epstein-Barr virus was more likely to be shed in saliva than Kaposi sarcoma–associated virus. Child’s sex and parasitic infections influenced viral shedding. Shedding of each virus was inversely related, suggesting an interaction between them.
Genetic Variation of the Pathogen Causing Impatiens Downy Mildew Predating and Including Twenty-first Century Epidemics on Impatiens walleriana
Authors: Salgado-Salazar Catalina , LeBlanc Nicholas , Ismaiel Adnan , Rivera Yazmín , Warfield Colleen Y. , Crouch Jo Anne
Published: May 2018

Impatiens downy mildew (IDM) of cultivated Impatiens walleriana has had a significant economic impact on the ornamental horticulture industry in the United States and globally. Although recent IDM outbreaks started in 2003, downy mildews on noncultivated Impatiens species have been documented since the 1880s. To understand the relationship between the pathogen causing recent epidemics and the pathogen historically present in the United States, this work characterized genetic variation among a collection of 1,000 samples on 18 plant hosts. Samples included collections during recent IDM epidemics and historical herbarium specimens. Ten major genotypes were identified from cloned rDNA amplicon sequencing and endpoint SNP genotyping. Three genotypes accounted for >95% of the samples, with only one of these three genotypes found on samples predating recent IDM outbreaks. Based on phylogenetic analysis integrating data from three markers and the presence of individual genotypes on multiple Impatiens species, there was some evidence of pathogen-specific infection of I. noli-tangere, but the distinction between genotypes infecting I. walleriana and I. balsamina was not upheld. Overall, this work provides evidence that the majority of rDNA genotypes recovered from recent IDM epidemics are different from historical U.S. genotypes, and that these genotypes can infect Impatiens spp. other than I. walleriana.
Genotypic and Pathogenic Diversity ofColletotrichum sublineolaIsolates from Sorghum (Sorghum bicolor) and Johnsongrass (S. halepense) in the Southeastern United States
Authors: Xavier K. V. , Mizubuti E. S. G. , Queiroz M. V. , Chopra S. , Vaillancourt L.
Published: May 2018

Anthracnose caused by Colletotrichum sublineola is an important disease of cultivated sorghum (Sorghum bicolor) worldwide. Anthracnose is also common on the ubiquitous wild sorghum relative Johnsongrass (S. halepense). Analysis of repetitive molecular fingerprinting markers revealed that isolates of C. sublineola from both hosts in the southeastern United States were genotypically diverse, with relatively few haplotypes found in more than one location. With few exceptions, isolates recovered from S. bicolor belonged to a population that was genetically distinct from the population recovered from S. halepense. Twenty-three isolates from cultivated sorghum were all pathogenic to at least one of 13 heritage inbred lines of S. bicolor. In all, 4 of 10 isolates from S. halepense were also pathogenic to one or more of the lines, while the rest caused no disease in greenhouse assays. The four pathogenic isolates from S. halepense were less aggressive, on average, than isolates from S. bicolor, although the ranges overlapped. Pathogenicity tests involving 15 representative pathogenic isolates from S. bicolor and S. halepense on eight heritage inbred lines of S. bicolor identified 12 races. The combined results of this study demonstrated that C. sublineola comprises two separate host-associated subpopulations in the field, even though some isolates from S. halepense were able to cause disease on S. bicolor under ideal greenhouse conditions. Nonetheless, the apparent existence of infrequent cross-infection events in the field, indicated by molecular fingerprinting, suggests that Johnsongrass has the potential to serve as a refuge and an incubator for genetic diversity in C. sublineola, which can complicate efforts to develop and deploy resistant sweet sorghum varieties in the region.
Mechanistic Origins of Dynamic Instability in Filaments from the Phage Tubulin, PhuZ
Authors: Zehr Elena A. , Rohu Alexis , Liu Yanxin , Verba Kliment A. , Pogliano Joe , Grigorieff Nikolaus , Agard David A.
Published: May 2018

A bacteriophage-encoded tubulin homologue, PhuZ, harnesses dynamic instability to position genomes of ՓKZ-like bacteriophage at the midline of their Pseudomonas hosts, facilitating phage infectivity. While much has been learned about molecular origins of microtubule dynamics, how GTP binding and hydrolysis control dynamics in the divergent 3-stranded PhuZ filaments is not understood. Here we present cryo-EM reconstructions of the PhuZ filamentin a pre-hydrolysis (3.5Å) and three post-hydrolysis states (4.2 Å, 7.3 Å and 8.1 Å resolutions), likely representing distinct depolymerization stages. Core polymerization-induced structural changes reveal similarities to αβ-tubulin, suggesting broad conservation within the tubulin family. By contrast, GTP hydrolysis is sensed quite differently and is communicated by the divergent PhuZ C-terminus to the lateral interface, leading to PhuZ polymer destabilization. This provides a contrasting molecular description of how nucleotide state can be harnessed by the tubulin fold to regulate filament assembly, metastability and disassembly.
Expert Specification of the ACMG/AMP Variant Interpretation Guidelines for Genetic Hearing Loss
Authors: Oza Andrea M. , DiStefano Marina T. , Hemphill Sarah E. , Cushman Brandon J. , Grant Andrew R. , Siegert Rebecca K. , Shen Jun , Chapin Alex , Boczek Nicole J. , Schimmenti Lisa A. , Murry Jaclyn B. , Hasadsri Linda , Nara Kiyomitsu , Kenna Margaret , Booth Kevin T. , Azaiez Hela , Griffith Andrew , Avraham Karen B. , Kremer Hannie , Rehm Heidi L. , Amr Sami S. , Abou Tayoun Ahmad N. ,   ClinGen Hearing Loss Clinical Domain Working Group
Published: May 2018

Due to the high genetic heterogeneity of hearing loss, current clinical testing includes sequencing large numbers of genes, which often yields a significant number of novel variants. Therefore, the standardization of variant interpretation is crucial to provide consistent and accurate diagnoses. The Hearing Loss Variant Curation Expert Panel was created within the Clinical Genome Resource to provide expert guidance for standardized genomic interpretation in the context of hearing loss. As one of its major tasks, our Expert Panel has adapted the American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) standards and guidelines for the interpretation of sequence variants in hearing loss genes. Here, we provide a comprehensive illustration of the newly specified ACMG/AMP hearing loss rules. Three rules remained unchanged, four rules were removed, and the remaining twenty-one rules were specified. Of the specified rules, four had general recommendations, seven were gene/disease considerations, seven had strength-level specifications, and three rules had both gene/disease and strength-level specifications. These rules were further validated and refined using a pilot set of 51 variants assessed by curators. These hearing loss-specific ACMG/AMP rules will help standardize variant interpretation, ultimately leading to better care for individuals with hearing loss.

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Research reported in this publication was supported by the National Human Genome Research Institute (NHGRI) under award number U41HG006834.
Estimating the timing of multiple admixture pulses during local ancestry inference
Authors: Medina Paloma , Thornlow Bryan , Nielsen Rasmus , Corbett-Detig Russell
Published: May 2018

Admixture, the mixing of genetically distinct populations, is increasingly recognized as a fundamental biological process. One major goal of admixture analyses is to estimate the timing of admixture events. Whereas most methods today can only detect the most recent admixture event, here we present coalescent theory and associated software that can be used to estimate the timing of multiple admixture events in an admixed population. We extensively validate this approach and evaluate the conditions under which it can succesfully distinguish one from two-pulse admixture models. We apply our approach to real and simulated data of Drosophila melanogaster. We find evidence of a single very recent pulse of cosmopolitan ancestry contributing to African populations as well as evidence for more ancient admixture among genetically differentiated populations in sub-Saharan Africa. These results suggest our method can quantify complex admixture histories involving genetic material introduced by multiple discrete admixture pulses. The new method facilitates the exploration of admixture and its contribution to adaptation, ecological divergence, and speciation.
Functional impact of the H2A.Z histone variant during meiosis inSaccharomyces cerevisiae
Authors: González-Arranz Sara , Cavero Santiago , Morillo-Huesca Macarena , Andújar Eloisa , Pérez-Alegre Mónica , Prado Félix , San-Segundo Pedro
Published: May 2018

Among the collection of chromatin modifications that influence its function and structure, the substitution of canonical histones by the so-called histone variants is one of the most prominent actions. Since crucial meiotic transactions are modulated by chromatin, here we investigate the functional contribution of the H2A.Z histone variant during both unperturbed meiosis and upon challenging conditions where the meiotic recombination checkpoint is triggered in budding yeast by the absence of the synaptonemal complex component Zip1. We have found that H2A.Z localizes to meiotic chromosomes in an SWR1-dependent manner. Although meiotic recombination is not substantially altered, thehtz1mutant (lacking H2A.Z) shows inefficient meiotic progression, impaired sporulation and reduced spore viability. These phenotypes are likely accounted for by the misregulation of meiotic gene expression landscape observed inhtz1. In thezip1mutant, the absence of H2A.Z results in a tighter meiotic arrest imposed by the meiotic recombination checkpoint. We have found that Mec1-dependent Hop1-T318 phosphorylation and the ensuing Mek1 activation are not significantly altered inzip1 htz1; however, downstream checkpoint targets, such as the meiosis I-promoting factors Ndt80, Cdc5 and Clb1, are drastically down-regulated. The study of the checkpoint response inzip1 htz1has also allowed us to reveal the existence of an additional function of the Swe1 kinase, independent of CDK inhibitory phosphorylation, which is relevant to restrain meiotic cell cycle progression. In summary, our study shows that the H2A.Z histone variant impacts various aspects of meiotic development adding further insight into the relevance of chromatin dynamics for accurate gametogenesis.
Seed Selection Strategies for Overlap Detection
Authors: Teutenberg Jonathan
Published: May 2018

The current state-of-the-art assemblers of long, error-prone reads rely on detecting all-vs-all overlaps within the set of reads with overlaps represented by a sparse selection of short subsequences or “seeds”. Though the quality of selection of these seeds can impact both accuracy and speed of overlap detection, existing algorithms do little more than ignore over-represented seeds. Here we propose several more informed seed selection strategies to improve precision and recall of overlaps. These strategies are evaluated against real long-read data sets with a range of fixed seed sizes. We show that these strategies substantially improve the utility of individual seeds over uninformed selection.
Repression of ferritin light chain translation by human eIF3
Authors: Pulos-Holmes Mia C. , Srole Daniel N. , Lee Amy S. Y. , Juarez Maria G. , McSwiggen David T. , Ingolia Nicholas T. , Cate Jamie H. D.
Published: May 2018

A central problem in human biology remains the discovery of causal molecular links between mutations identified in genome-wide association studies (GWAS) and their corresponding disease traits. This challenge is magnified for variants residing in non-coding regions of the genome. Single-nucleotide polymorphisms (SNPs) in the 5’ untranslated region (5’-UTR) of the ferritin light chain (FTL) gene that cause hyperferritinemia are thought to disrupt translation repression by altering iron regulatory protein (IRP) interactions with theFTLmRNA 5’-UTR. Here, we show that human eukaryotic translation initiation factor 3 (eIF3) acts as a distinct repressor ofFTLmRNA translation, and eIF3-mediatedFTLrepression is disrupted by a subset of SNPs inFTLthat cause hyperferritinemia. These results identify a direct role for eIF3-mediated translational control in a specific human disease.
Anisotropic growth is achieved through the additive mechanical effect of material anisotropy and elastic asymmetry
Authors: Bou Daher Firas , Chen Yuanjie , Bozorg Behruz , Clough Jack , Jönsson Henrik , Braybrook Siobhan A
Published: May 2018

Fast directional growth is a necessity for the young seedling: after germination, the seedling needs to quickly reach through the soil to begin its autotrophic life. In most dicot plants, this rapid escape is due to the anisotropic elongation of the hypocotyl, the columnar organ between the root and the shoot meristems. Such anisotropic growth is common in many plant organs and is canonically attributed to cell wall anisotropy produced by oriented cellulose fibers in the cell wall. More recently, a mechanism based on asymmetric cell wall elasticity has been proposed, produced by differential pectin biochemistry. Here we present a harmonizing model for anisotropic growth control in the dark-grown Arabidopsis hypocotyl: basic anisotropic information is provided by cellulose orientation (proxied by microtubules) and additive anisotropic information is provided by pectin-based elastic asymmetry in the epidermis. We demonstrate that hypocotyl growth was always anisotropic with axial and transverse walls growing differently, from germination. We present experimental evidence for pectin biochemical differences and wall mechanics underlying this differential growth. We demonstrate that pectin biochemical changes control the transition to rapid growth characteristic of Arabidopsis hypocotyl elongation, and provide evidence for a substantial mechanical role for pectin in the cell wall when microtubules are compromised. Lastly, our in silico modelling experiments indicate an additive combination for pectin biochemistry and cellulose orientation in promoting anisotropic growth.
Genetic incompatibility combined with female-lethality is effective and robust in simulations of Aedes aegypti population control
Authors: Maselko Maciej , Heinsch Stephen , Das Siba , Smanski Michael J.
Published: May 2018

Recent reports of CRISPR/Cas9-based suppression gene drives in insects underscore the challenge of overcoming genetic resistance. Here we present results from agent-based simulation modeling of a novel Field-Amplified Male Sterility System (FAMSS) that outperforms suppression gene drives when challenged with genetic resistance. FAMSS combines a recently described synthetic genetic incompatibility approach with previously demonstrated female-lethality constructs. Our results suggest that FAMSS will be an effective strategy for temporally and spatially self-limited suppression of the disease vectoring mosquito, Aedes aegypti.
Habitat heterogeneity reduces richness of ant species by increasing abundance of the local dominant species
Authors: Travassos-Britto B. , Rocha P. B. L.
Published: May 2018

The effect of environmental heterogeneity on species richness is frequently discussed in ecology. However, the empirical evidence has been contradictory as to the direction of the effect. Although some authors have considered that this might be a methodological problem, we argue that for ants, ecological interactions within the community, as interspecific competition is more important. We analyzed the plausibility of models in explaining the ant richness distribution patterns in a semi-desert environment. We used three predicting variables in the construction of the models to explain ant richness distribution: heterogeneity based on the amount of structures regardless of their type, heterogeneity based on the diversity of structures, and the abundance of individuals of the dominant species. We used ANOVA to chose the best model and corroborated the prediction that in this system abundance of dominant species is the best predictor of ant species richness. Neither of the heterogeneity conceptions contributed much to explain richness distribution. However, in a second analysis, we concluded that heterogeneity could affect the abundance of the dominant species. We conclude that competitive dominance is a better predictor of species richness distribution patterns than structural heterogeneity. However, the structural heterogeneity affects the distribution of dominant individuals. We suggest that some unexplained patterns observed about the relationship between heterogeneity and richness could be due to an indirect effect.