bluuebunny/crossref_metadata_2025 huggingface dataset:
Short‐term responses in a secondary tropical forest after a severe windstorm event
Authors: Yee Alex T. K. , Lai Hao Ran , Chong Kwek Yan , Neo Louise , Koh Choon Yen , Tan Siu Yueh , Seah Wei Wei , Loh Jolyn W. , Lim Reuben C. J. , van Breugel Michiel , Tan Hugh T. W.
Published: April 2019

Questions

How do abiotic conditions, forest structure, as well as taxonomic and functional diversities and composition recover after wind‐generated treefalls? Do young and old‐growth secondary forests differ in their responses?

Location

Mandai region of the Central Catchment Nature Reserve, Singapore, where extensive treefalls occurred during an unusually powerful windstorm in 2011. Southeast Asia.

Methods

Soil nitrogen, phosphorous, potassium, canopy cover, leaf litter depth, coarse woody debris, and woody stems ≥1‐cm diameter were measured and identified in 10 × 10 m plots. Twenty‐six plots were located in treefall areas and 14 plots were located in relatively unaffected areas, with equal numbers in young and old‐growth secondary forest types. The first round of surveys took place within 3–6 months of the windstorm event and yearly re‐surveys were conducted until 2015. Specific leaf area, leaf dry matter content, leaf thickness, woody density, maximum plant height, and seed dry mass were measured or derived from various sources.

Results

There was a pulse of soil nutrient availability in both affected and unaffected areas 1 year after the wind event. Canopy cover and basal area in the affected areas recovered to similar levels as unaffected areas by the second year, and coarse woody debris by the fourth year. In affected plots, taxonomic and functional diversities increased and overshot that of—and taxonomic composition diverged from—unaffected plots after the second year. Young and old‐growth secondary forest types mainly differed in the taxonomic composition of new recruits. However, there was no evidence of changes in functional composition towards resource‐acquisitive strategies such as lower wood density or higher specific leaf area.

Conclusions

Abiotic conditions and basal area recovered rapidly within 2–4 years after the windstorm. Taxonomic composition in young and old‐growth affected forests both diverged from unaffected forests but also from each other over time.
Epigenetic dynamics during flowering plant reproduction: evidence for reprogramming?
Authors: Gehring Mary
Published: April 2019

Over the last 10 yr there have been major advances in documenting and understanding dynamic changes to DNA methylation, small RNAs, chromatin modifications and chromatin structure that accompany reproductive development in flowering plants, from germline specification to seed maturation. Here I highlight recent advances in the field, mostly made possible by microscopic analysis of epigenetic states or by the ability to isolate specific cell types or tissues and apply omics approaches. I consider in which contexts there is potentially reprogramming vs maintenance or reinforcement of epigenetic states.
Molecular mechanisms of adaptive evolution revealed by global selection for glyphosate resistance
Authors: Gaines Todd A. , Patterson Eric L. , Neve Paul
Published: April 2019

The human‐directed, global selection for glyphosate resistance in weeds has revealed a fascinating diversity of evolved resistance mechanisms, including herbicide sequestration in the vacuole, a rapid cell death response, nucleotide polymorphisms in the herbicide target (5‐enolpyruvylshikimate‐3‐phosphate synthase, EPSPS) and increased gene copy number of EPSPS. For this latter mechanism, two distinct molecular genetic mechanisms have been observed, a tandem duplication mechanism and a large extrachromosomal circular DNA (eccDNA) that is tethered to the chromosomes and passed to gametes at meiosis. These divergent mechanisms have a range of consequences for the spread, fitness, and inheritance of resistance traits, and, particularly in the case of the eccDNA, demonstrate how evolved herbicide resistance can generate new insights into plant adaptation to contemporary environmental stress.
Risk Sharing and Institutional Quality: Evidence from OECD and Emerging Economies
Authors: Faruk Balli , Eleonora Pierucci
Published: April 2019

In this paper, we investigate the impact of institutional quality on risk sharing across Organisation for Economic Co‐operation and Development (OECD) and emerging economies (EMEs). It has been found that the quality of institutions and risk sharing are significantly interrelated among OECD members (mostly through credit market channel), but not for the EMEs. Our results are consistent when we control for pre‐ and post‐GFC periods. The reason why the impact of institutional quality on risk sharing is limited among EMEs might be due to the significant monetary injections from advanced economies in the form of remittances and financial aid which might understate other factors that influence risk sharing.
Firearm Ownership and Capability for Suicide in Post‐Deployment National Guard Service Members
Authors: Goldberg Simon B. , Tucker Raymond P. , Abbas Maleeha , Schultz Megan E. , Hiserodt Michele , Thomas Kathryn A. , Anestis Michael D. , Wyman Mary F.
Published: April 2019

Objective

National Guard service members demonstrate increased suicide risk relative to the civilian population. One potential mechanism for this increased risk may be familiarity with and access to firearms following deployment. This study examined the association between firearm ownership, reasons for ownership, and firearm familiarity with a widely studied suicide risk factor—capability for suicide—among National Guard service members.

Method

Data were drawn from a cross‐sectional survey of National Guard service members conducted immediately post‐deployment in 2010. Service members (n = 2,292) completed measures of firearm ownership, firearm familiarity, and capability for suicide.

Results

Firearm ownership and increased firearm familiarity were associated with capability for suicide (d = 0.47 and r = .25, for firearm ownership and familiarity, respectively). When examined separately based on reason for ownership, owning a firearm for self‐protection (d = 0.33) or owning a military weapon (d = 0.27) remained significantly associated with capability for suicide. In contrast, owning a firearm for hobby purposes did not (d = −0.07).

Conclusion

Our findings support theories emphasizing practical aspects of suicide (e.g., three‐step theory) and suggest that owning firearms, in particular for self‐protection, along with familiarity using firearms may be associated with greater capability for suicide.
Exploring Sensitive Topics in an Authoritarian Context: An Insider Perspective*
Authors: Yusupova Guzel
Published: April 2019

Object

This article examines the methodological challenges of ethnographic research on ethnic and religious minorities, in an authoritarian context in the Russian Federation, conducted by an insider researcher.

Method

The article focuses on the peculiarities of the insider position in the field of research on understudied topics concerning ethnic and religious minorities. These cover issues of influence of national and local academic agendas on the process of the research, credibility management in a highly dynamic political environment, research safety, and the researcher's influence on the field.

Results

The article identifies three main challenges in doing ethnography in illiberal settings. First, the imposition of oblique political limitations on the research agenda of local researchers creates a form of methodological nationalism, leading to a paucity of research on some critical topics. Second, the continuous introduction of new restrictive legislation not only results in difficulties of accessing the field, but also demands constant reevaluation of the sensitivity of the questionnaire. Respondents often express anxiety while discussing even quotidian practices because it becomes difficult for them to anticipate whether, when, or how new restrictive legislation will be enforced. Thus, they expect insider researchers to be aware of the legal ramifications of their research. Not only does this nullify the author's ability to adopt a stance of naivety, it also means that researchers bear a greater burden in convincing respondents that the information provided will be handled responsibly. Finally, the ethnographer is constantly faced with difficult decisions regarding both scholarly and ethical reliability and, hence, is required to continuously review research ethics in such a dynamic political context. This article offers suggestions for overcoming these difficulties by means of social networking services and constant critical reflexivity.

Conclusion

Authoritarian settings pose many challenges to insider researchers. The study of minority groups can be particularly sensitive since illiberal regimes often seek to homogenize their populations and portray minority groups as a threat to justify the state's increasing control over the population. Exploring even mundane, everyday manifestations of ethnicity in such situations can become highly sensitive and raise methodological problems such as limitation of available academic literature and funding, greater responsibility for research and participants’ safety, and forced partisanship.
The HLA‐DRB1*04:90 allele recognized in a Taiwanese individual
Authors: Yang Kuo‐Liang , Lin Py‐Yu
Published: April 2019

Nucleotide substitutions in codon 78 of HLA‐DRB1*04:05:01:01 result in a new allele, HLA‐DRB1*04:90.
Issues around vaginal vault closure
Authors: Moustafa Magdy , Elnasharty Mohamed
Published: April 2019

Key content

Vaginal cuff dehiscence (VCD), vault prolapse, vaginal cuff granulation and infected vault haematoma are adverse events following hysterectomy.

There are several approaches to closing the vaginal cuff, each using different techniques and sutures.

Dehiscence of the vaginal cuff is more common with laparoscopic hysterectomy. Techniques that minimise excessive use of diathermy may reduce the risk of vault dehiscence.

The incidence of post‐hysterectomy vault prolapse is estimated to be between 1.8% and 11.6%. McCall culdoplasty seems to be effective in supporting the vaginal vault.

Different techniques are used to minimise the development of vault haematoma and granulation tissue.

Learning objectives

To understand the different techniques used for vault closure during hysterectomy.

To understand the different surgical approaches used to reduce the risk of vault dehiscence, vault prolapse and haematoma after hysterectomy.

To understand the post‐operative care procedure that should be followed after hysterectomy to minimise the risk of vaginal vault complications.

Ethical issues

Patients should be aware of the risk of vaginal vault dehiscence, vault prolapse, haematoma and granulation tissue formation after hysterectomy.

Trainees should be well trained using simulators, be supervised when performing laparoscopic vaginal vault closure and be made aware that vaginal closure is another safe treatment option.
Relationship of GUN1 to FUG1 in chloroplast protein homeostasis
Authors: Marino Giada , Naranjo Belen , Wang Jing , Penzler Jan‐Ferdinand , Kleine Tatjana , Leister Dario
Published: April 2019

GUN1 integrates retrograde signals in chloroplasts but the underlying mechanism is elusive. FUG1, a chloroplast translation initiation factor, and GUN1 are co‐expressed at the transcriptional level, and FUG1 co‐immunoprecipitates with GUN1. We used mutants of GUN1 (gun1‐103) and FUG1 (fug1‐3) to analyse their functional relationship at the physiological and system‐wide level, the latter including transcriptome and proteome analyses. Absence of GUN1 aggravates the effects of decreased FUG1 levels on chloroplast protein translation, resulting in transiently more pronounced phenotypes regarding photosynthesis, leaf colouration, growth and cold acclimation. The gun1‐103 mutation also enhances variegation in the var2 mutant, increasing the fraction of white sectors, while fug1‐3 suppresses the var2 phenotype. The transcriptomes of fug1‐3 and gun1‐103 plants are very similar, but absence of GUN1 alone has almost no effect on protein levels, whereas steady‐state levels of chloroplast proteins are markedly decreased in fug1‐3. In fug1 gun1 double mutants, effects on transcriptomes and particularly on proteomes are enhanced. Our results show that GUN1 function becomes critical when chloroplast proteostasis is perturbed by decreased rates of synthesis (fug1) or degradation (var2) of chloroplast proteins, or by low temperatures. The functions of FUG1 and GUN1 appear to be related, corroborating the view that GUN1 helps to maintain chloroplast protein homeostasis (proteostasis).
CO2‐fixing liquid droplets: Towards a dissection of the microalgal pyrenoid
Authors: Wunder Tobias , Oh Zhen Guo , Mueller‐Cajar Oliver
Published: April 2019

CO2 enters the biosphere via the slow, oxygen‐sensitive carboxylase, Rubisco. To compensate, most microalgae saturate Rubisco with its substrate gas through a carbon dioxide concentrating mechanism. This strategy frequently involves compartmentalization of the enzyme in the pyrenoid, a non‐membrane enclosed compartment of the chloroplast stroma. Recently, tremendous advances have been achieved concerning the structure, physical properties, composition and in vitro reconstitution of the pyrenoid matrix from the green alga Chlamydomonas reinhardtii. The discovery of the intrinsically disordered multivalent Rubisco linker protein EPYC1 provided a biochemical framework to explain the subsequent finding that the pyrenoid resembles a liquid droplet in vivo. Reconstitution of the corresponding liquid‐liquid phase separation using pure Rubisco and EPYC1 allowed a detailed characterization of this process. Finally, a large high‐quality dataset of pyrenoidal protein‐protein interactions inclusive of spatial information provides ample substrate for rapid further functional dissection of the pyrenoid. Integrating and extending recent advances will inform synthetic biology efforts towards enhancing plant photosynthesis as well as contribute a versatile model towards experimentally dissecting the biochemistry of enzyme‐containing membraneless organelles.
Rhnull phenotype caused by a novel RHAG mutation, c.945+1G>A, in the Japanese population
Authors: Ushiki Takashi , Tsuneyama Hatsue , Masuko Masayoshi , Kozakai Takashi , Kasami Takuya , Tanaka Tomoyuki , Uchikawa Makoto , Kitajima Toshiki , Kasai Emiko , Komata Tae , Katagiri Takayuki , Kamimura Masami , Sato Kenji , Fuse Ichiro , Ogasawara Kenichi , Nakata Koh
Published: April 2019

BACKGROUND

The Rh complex contributes to cell membrane structural integrity of erythrocytes. Rhnull syndrome is characterized by the absence of the Rh antigen on the erythrocyte membrane, resulting in chronic hemolytic anemia. We recently came across 3 Rhnull phenotype probands within two families with the same novel RHAG mutation in the Japanese population.

MATERIALS AND METHODS

Detailed Rh phenotyping by hemagglutination was performed using monoclonal and polyclonal anti‐D, ‐C, −c, −E, and ‐e; monoclonal and polyclonal anti‐Rh17 antibodies; and polyclonal anti‐Rh29 antibodies. RHAG mRNA transcripts were analyzed by reverse transcription–polymerase chain reaction, and the mutation was verified by genomic sequencing.

RESULTS

The genomic region spanning exon 6 contained a G > A transition in the invariant GT motif of the 5′ donor splice‐site of Intron 6 (c.945+1G>A). The Rhnull phenotype was caused by an autosomal recessive mutation in Probands 1 and 2, determined by family history. Regarding clinical features, the degree of hemolysis varied slightly between these individuals, with Proband 3 displaying acute hemolytic anemia with an infection. While no standard therapy has been established, the condition of the patient in this study improved with conservative treatment, including hydration and antibiotics.

CONCLUSION

The mechanisms of hemolysis due to the Rhnull phenotype can vary, but our findings indicate that acute hemolytic crisis caused by the Rhnull syndrome could be associated with infection.
Detecting learning‐by‐exporting effects on firms' productivity distribution by accounting for heterogeneous macrofactors and panel attrition
Authors: Ferrante Maria R. , Freo Marzia
Published: April 2019

This paper aims to verify the presence of the learning‐by‐exporting effect on total factor productivity growth. The study starts, as is typical in this context, by addressing the pre‐entry selection bias at firm level but differs from the literature by focusing on the distribution of the outcome and considering the presence of the different influences of macroeconomic factors on exporters and non‐exporters. Additionally, the paper addresses the panel attrition, a current source of estimation bias in longitudinal studies. The analysis is based on a panel of Italian manufacturing firms in the 1998–2007 period. We design an experiment by aligning and pooling cohorts of firms that allow us to obtain a sufficiently large group of firms entering the international market. Our results show that internationalisation affects firms' productivity and that the effect is heterogeneous over total factor productivity distribution and larger for the firms at the bottom section of the distribution itself. Furthermore, we observe that the learning‐by‐exporting effect may be confounded without (a) considering that domestic and exporter firms may afford heterogeneous demand cycles and (b) managing the dropout of some firms from the panel.
Alar fold resection in 25 horses: Clinical findings and effect on racing performance and airway mechanics (1998‐2013)
Authors: Strand Eric , Össurardóttir Saga , Wettre Kjersti B. , Fjordbakk Cathrine T.
Published: April 2019

Objective

To report clinical findings and performance in horses in which alar fold collapse (AFC) had been diagnosed and surgically treated and to assess form and degree of respiratory obstruction.

Study design

Retrospective case series.

Animals

Twenty‐one standardbreds, 2 coldblooded trotter racehorses, 1 thoroughbred, and 1 Icelandic horse.

Methods

Alar fold collapse was diagnosed on the basis of continuous abnormal expiratory flutter noise coinciding with filling of the false nostrils during exercise on a high‐speed treadmill that was alleviated by suturing the alar folds (AF) temporarily in a dorsal position. In 5 cases, nasopharyngeal airway pressures were assessed. Performance after complete, bilateral AF resection was assessed by reviewing career race records and by owner or trainer telephone interviews.

Results

Horses presented because of poor performance, abnormal respiratory noise, or both. Additional dynamic disorders were identified in 12 of 21 standardbreds (intermittent dorsal displacement of the soft palate: n = 10; collapse of the roof of the nasopharynx: n = 2). Expiratory nasopharyngeal pressures seemed elevated in horses with AFC (range, +10.8 to +21.8 cm H2O) compared with normal reference values. Dorsal fixation as well as complete surgical resection of the AF improved expiratory nasopharyngeal pressures to reported normal levels. At a mean of 68 months (range, 7‐121) follow‐up, 20 of 25 horses had competed after surgery, and 13 of 17 of the harness racehorses had established or improved their kilometer racing time marks.

Conclusion

Alar fold collapse caused mild to moderate expiratory obstruction and may have contributed to secondary nasopharyngeal collapse in this population.

Clinical significance

Complete surgical resection seems effective for treating AFC. Nasopharyngeal pressure measurement is a potential tool for confirming the diagnosis of AFC.
IN VITRO PRESERVATION OF RODENT TUBER (TYPHONIUM FLAGELLIFORME LODD.) PEKALONGAN ACCESSION WITH PACLOBUTRAZOL
Authors: Sianipar Nesti Fronika , Naftalia Naftalia , Purnamaningsih Ragapadmi
Published: April 2019

Rodent tuber plant (Typhonium flagelliforme Lodd.), as one of the most potent medicinal plants, has to be developed as an active ingredient of degenerative drugs, including cancer drugs. However, this enormous potential must be supported by sustainable cultivation of the plant. The conventional preservation of rodent tuber can be done by planting various accessions in the field, but it will need land availability and intensive plant maintenance. Preservation through in vitro culture is an alternative method that can be used. The aim of this study was to determine the effect of paclobutrazol in suppressing the growth of rodent tuber cultures, and test the ability of culture regeneration after being preserved with paclobutrazol. The media formulation used was Murashige and Skoog (1962) (MS) with the addition of paclobutrazol at concentrations of 4, 5, 6, and 7 mg L-1. The results showed that using paclobutrazol at 5 mg L-1 was the best concentration that can inhibit the elongation of buds, seedling formation, leaf formation, and root elongation until 5 months. Cultures of paclobutrazol treatment at 5 mg L-1 had shoot heights, number of shoots, number of leaves, and root lengths of 0.49, 2.33, 7.23, and 0.3 cm, respectively. Paclobutrazol could inhibit the growth of in vitroculture of rodent tuber and prolong the shelf life of culture up to 5 months. The culture of rodent tuber from paclobutrazol treatment had normal growth and regenerative ability after transfer to the medium regeneration.
MULTI-TEMPORAL MODIS FOR DETECTION AND PUBLISHED LITERATURES FOR VALIDATION OF PHYTOPLANKTON BLOOMS IN SABAH AND SARAWAK, MALAYSIA
Authors: Hossain Mohammad Shawkat , Hashim Mazlan , Muslim Mohamed Aidy
Published: April 2019

The coastal region of Sabah, Malaysia is mostly affected by harmful algal blooms (HABs) that often cause massive fish kills, and sometimes human casualties. Lack of a well-agreed, transparent and reproducible method, aperiodic nature and limited (technical) ability to monitor HAB at large regional scale, have all led to reinforced methodological improvement for bloom prediction, scientific management of coastal water resources, and regulatory attention. MODerate Resolution Imaging Spectroradiometer (MODIS), one of the well validated ocean colour sensors, enables acquiring high spectral resolution images, with short revisit time, freely accessible, and bay-wide coverage. Yet, the relative efficiency of MODIS-derived Chl-a (Chlorophyll-a), ABI (Algal Bloom Index), and nFLH (normalized Fluorescence Line Height) have not been compared in coastal regions of Malaysia. Fifteen MODIS Level 2 images acquired between 2005 and 2013 were considered as time series data that matched HAB events mentioned in previous studies. As historical real time in-situ data collection is often difficult (inaccessible), and thus unavailable; this project had to validate results obtained from literature, assuming that in-situ, would indicate HAB location at least during MODIS acquisition dates. Variations of HAB affected areas with temporal and spatial scales derived from bloom indices are shown in colour maps. Reliability of bloom information was measured by subjectively comparing HAB results provided by indices, and previously published in-situ results. ABI outperformed Chl-a and nFLH indices based on comparisons in both normal and HAB conditions occurring in the coastal waters of Sabah and Sarawak. The configuration and reliability retrieved from MODIS-ABI allowed their application in different likely tropical region as automated HAB monitoring systems and coastal water management programmes.
TREATING PALM OIL MILL EFFLUENT BY ACTIVATED SLUDGE PROCESS USING SUBMERGED MECHANICAL AERATOR/AGITATOR REPLACING SURFACE AERATOR
Authors: Hawari Yahaya , Yahya Wira Jazair , Sonda Ikuma , Kawashima Hirotaka , Mohamad Zahari , Abu Bakar Muhammad Aiman , Abd Kadir Hasannuddin
Published: April 2019

Activated sludge process (ASP) is gaining recognition as a process technique for the control of biological oxygen demand (BOD) in palm oil mill effluent (POME). Surface aerators or diffusing plates are often used in aeration tanks serving as core of the ASP. For consistent improvement in water quality within the aeration tank utilising the ASP and in particular, mitigating its BOD effluent stream, this study replaced the surface aerator with submerged mechanical aerator/agitator incorporating separate “agitation function” and “agitation diffusing function” intended for use in aeration tank of polishing plant that contains surface aerators. In order to confirm the activated state of the sludge in the aeration tanks, sludge was observed by microscopy (magnification 600 ´ or lower). The water analysis, POME, BOD, ammonium, and total nitrogen were analsyed. As a result of the study, improvement in water quality criteria including the agitation state in the aeration tank, mixed liquid dissolved oxygen, and BOD were observed. The BOD has improved from 34.7% to 93.1% at a maximum removal rate.
RELATIVE CHARACTERIZATION OF IMMOBILIZED BETA-GLUCOSIDASE ON CALCIUM-ALGINATE AND ACID FUNCTIONALIZED MULTIWALLED CARBON NANOTUBES
Authors: Jameel Ahmad T. , Maalim Kauthar Y. , Yusof Faridah
Published: April 2019

Natural polymeric gel such as alginate and carrageenan, and carbon nanomaterials, especially MWCNT and graphene are gaining increasing popularity as immobilization support owing to their biocompatibility. Thus, this study attempts to make a relative characterization of the immobilized β-glucosidase on alginate and multiwalled carbon nanotubes (MWCNT) to assess their relative merits as biocatalyst. Acid functionalization of MWCNT lead to the formation of carboxyl groups at the MWCNT surface which seemed to have role in the stable attachment of the enzyme on the MWCNT surface. The effectiveness of the immobilized enzyme was evaluated using hydrolysis of p-nitrophenyl-β-D-glucopyranoside to p-nitrophenol. The optimum immobilization conditions were found to be 17 mg MWCNT and 4 h incubation time for MWCNT, and 3.5 wt% sodium alginate solution and 2 h incubation time for the Ca-alginate beads. The immobilization yield on MWCNT was found to be 96% and that for the Ca-alginate beads was 86%. The residual activity of the enzyme at the third cycle of subsequent reuse was 85% for the enzyme-MWCNT and almost 50% for the enzyme-alginate beads. Both, Ca-alginate and MWCNT immobilized enzyme were found to follow Michaelis-Menten kinetics. The kinetic data were best represented by the Langmuir plot. The kinetic constants Vmax and Km for the MWCNT immobilized enzyme were obtained as 1.324 mM/min and 0.801 mM, respectively, while for the alginate immobilized enzyme, the constants predicted were 1.240 mM/min and 0.524 mM, respectively. Thus MWCNT immobilized β-glucosidase exhibited greater stability in terms of activity and reusability compared to Ca-alginate beads.
Fluid–Structure Interaction Effects on Free Vibration of Containerships
Authors: Sepehrirahnama Shahrokh , Xu Dong , Ong Eng Teo , Lee Heow Pueh , Lim Kian-Meng
Published: April 2019

The interaction between fluid and structure affects the vibration response of the structure due to the additional hydrodynamic pressure. These effects are accounted for by incorporating the so-called added mass into the vibration equation of the structure. In this paper, a containership was used to study the impact of the added mass on its free vibration response. The natural frequencies of the ship decrease after including the added mass in the vibration analysis. It is shown that the frequency-ascending sequence of the wet mode shapes, for which the added mass is accounted for, may differ from that obtained for the dry state of the ship. Also, the effects of different draft levels on the mode shapes of the ship are reported. These results provide a better insight for designing ships based on their wet-state frequencies and mode shapes, which is the typical operation condition when sailing in the open seas.
Analysis of an Additively Manufactured Cooled Ultra Compact Combustor Vane
Authors: DeMarco Kevin J. , Bohan Brian T. , Polanka Marc D. , Rutledge James L. , Akbari Pejman
Published: April 2019

The ultra compact combustor (UCC) aims to increase the thrust-to-weight ratio of an aircraft gas turbine engine by decreasing the size, and thus weight, of the engine’s combustor. The configuration of the UCC as a primary combustor enables a unique cooling scheme to be employed for the hybrid guide vane (HGV). A previous effort conducted a computational fluid dynamics (CFD) analysis that evaluated whether it would be possible to cool this vane by drawing in freestream flow at the stagnation region of the airfoil. Based on this study, a cooling scheme was designed and modified with internal supports to make additive manufacturing of the vanes possible. This vane was computationally evaluated comparing the results with those of a solid vane and hollow vane without cooling holes as a demonstration of the improvements offered by this design. Furthermore, the effects of the internal support structure were deemed beneficial to surface cooling when evaluated through comparisons of internal pressure distribution and overall effectiveness. Following the computational study, the vane was manufactured and experimentally evaluated with the results compared to those of an uncooled solid vane. The experimental results validated the computational analysis and demonstrated through pressure and temperature measurements that the cooled vane had a reduced surface temperature compared to the uncooled vane and that pressure distributions supported coolant flow through film-cooling holes.
Atomic layer deposition of amorphous tin-gallium oxide films
Authors: Larsson Fredrik , Keller Jan , Primetzhofer Daniel , Riekehr Lars , Edoff Marika , Törndahl Tobias
Published: April 2019

A wide range of applications benefit from transparent semiconducting oxides with tunable electronic properties, for example, electron transport layers in solar cell devices, where the electron affinity is a key parameter. Presently, a few different ternary oxides are used for this purpose, but the attainable electron affinity range is typically limited. In this study, the authors develop a low-temperature atomic layer deposition (ALD) process to grow amorphous Sn1–xGaxOy thin films from dimethylamino-metal complexes and water. This oxide is predicted to provide a wide selection of possible electron affinity values, from around 3 eV for pure Ga2O3 to 4.5 eV for pure SnO2. The ALD process is evaluated for deposition temperatures in the range of 105–195 °C by in situ quartz crystal microbalance and with ex situ film characterization. The growth exhibits an ideal-like behavior at 175 °C, where the film composition can be predicted by a simple rule of mixture. Depending on film composition, the growth per cycle varies in the range of 0.6–0.8 Å at this temperature. Furthermore, the film composition for a given process appears insensitive to the deposition temperature. From material characterization, it is shown that the deposited films are highly resistive, fully amorphous, and homogeneous, with moderate levels of impurities (carbon, nitrogen, and hydrogen). By tailoring the metal cation ratio in films grown at 175 °C, the optical bandgap can be varied in the range from 2.7 eV for SnO2 to above 4.2 eV for Ga2O3. The bandgap also varies significantly as a function of deposition temperature. This control of properties indicates that Sn1–xGaxOy is a promising candidate for an electron transport layer material in a wide electron affinity range.
Comment on “Acceleration due to buoyancy and mass renormalization” [Am. J. Phys. 87, 165–170 (2019)]
Authors: Derbes David , Griffiths David , Sohn Richard
Published: April 2019

In a recent article, reference is made to a paper of George Green as quoted in the quantum field theory lectures of Sidney Coleman. The article describes Coleman's lectures as thus far unpublished. The purpose of this note is to announce the publication of Coleman's lectures and to provide details for the work cited.
Comment on “Relativistic phase velocity transformation” [Am. J. Phys. 57(7), 628–630 (1989)]
Authors: Drake Samuel Picton , Pointer Geoff
Published: April 2019

A formula for the transformation of phase velocity between two inertial observers is given. This is a correction of the formula provided by R. A. Bachman in Am. J. Phys. 57(7), 628–630 (1989), in which the transformation of the phase velocity perpendicular to the relative velocity of the two frames was incorrectly stated.
REVIEWS OF ACOUSTICAL PATENTS
Authors: Fulop Sean A.
Published: April 2019

The purpose of these acoustical patent reviews is to provide enough information for a Journal reader to decide whether to seek more information from the patent itself. Any opinions expressed here are those of the reviewers as individuals and are not legal opinions. Patents are available via the internet at the USPTO website, and also using Google Patents.
Geometric shapes effect of in-duct perforated orifices on aeroacoustics damping performances at low Helmholtz and Strouhal number
Authors: Zhao Dan , Ji Chenzhen , Wang Bing
Published: April 2019

In this work, experimental studies are conducted to measure the aeroacoustics damping performances of 11 in-duct perforated plates in a cold-flow pipe with a variable Mach number. These in-duct plates have the same porosities but different number N and geometric shaped orifices. Here six shapes are considered, i.e., (1) triangle, (2) square, (3) pentagon, (4) hexagon, (5) star, and (6) circle. It is shown that the orifice shape has little influence on power absorption Δ and reflection coefficient R at a lower Helmholtz number He ≤ 0.0903. However, as He is increased, the in-duct plate with a star-shaped orifice is shown to be with much lower Δ in comparison with that of other plates with different shape orifices. In addition, the perforated orifice with the same shape and porosity but a larger N is shown to be associated with 20% more power absorption at approximately He = 0.1244. Δmax is observed to be approximately 85% at about He = 0.0244, as Ma≈0.029. To gain more insights, the quasi-steady model is applied, depending on the Strouhal number Sr. The transition from quasi-steady flow behaviors to unsteady behaviors occurs at approximately Sr = 0.45. The measured minimum reflection coefficient Rmin occurs at Ma ≈ 0.024. This experimental finding is consistent with the quasi-steady prediction.
Direct observation of valley-coupled topological current in MoS
2
Authors: Hung Terry Y. T. , Camsari Kerem Y. , Zhang Shengjiao , Upadhyaya Pramey , Chen Zhihong
Published: April 2019

Electrical generation and detection of valley currents in MoS
2
is demonstrated as a robust phenomenon even at room temperature.
Prolonged evolution of the memory B cell response induced by a replicating adenovirus-influenza H5 vaccine
Authors: Matsuda Kenta , Huang Jinghe , Zhou Tongqing , Sheng Zizhang , Kang Byong H. , Ishida Elise , Griesman Trevor , Stuccio Sarah , Bolkhovitinov Lyuba , Wohlbold Teddy J. , Chromikova Veronika , Cagigi Alberto , Leung Kwanyee , Andrews Sarah , Cheung Crystal S. F. , Pullano Alyssa A. , Plyler Jason , Soto Cinque , Zhang Baoshan , Yang Yongping , Joyce M. Gordon , Tsybovsky Yaroslav , Wheatley Adam , Narpala Sandeep R. , Guo Yicheng , Darko Sam , Bailer Robert T. , Poole April , Liang C. Jason , Smith Jon , Alexander Jeff , Gurwith Marc , Migueles Stephen A. , Koup Richard A. , Golding Hana , Khurana Surender , McDermott Adrian B. , Shapiro Lawrence , Krammer Florian , Kwong Peter D. , Connors Mark
Published: April 2019

Ad4-H5 vaccine induces prolonged increases in H5-specific B cell frequency, antibody affinity, and somatic hypermutation.
New insights into the Precambrian tectonic evolution and continental affinity of the Qilian block: Evidence from geochronology and geochemistry of metasupracrustal rocks in the North Wulan terrane
Authors: Wang Lu , Johnston Stephen T. , Chen Nengsong
Published: April 2019

The Qilian block, one of the Precambrian terranes in the Qinling-Qilian-Kunlun orogenic system, is a critical region for reconstruction of the overall architecture and tectonic evolution of NW China. This investigation of zircon U-Pb and Lu-Hf isotopes and whole-rock geochemistry of a metasupracrustal sequence in the North Wulan terrane provides new insights into the Qilian block. A Statherian–Calymmian unit (ca. 1.67–1.5 Ga), dominated by Al- and Si-rich gneisses, arkosites, quartzites, and amphibolites with minor calc-silicate rocks and marbles, is interpreted to have been deposited during continental rifting. Detrital zircons show two main age populations of 2685–2276 and 2098–1761 Ma with mostly negative εHf(t) values (–14.0 to +3.6). The sources are characterized by mixed felsic to intermediate igneous rocks as well as recycled components and are interpreted as being derived from the Tarim craton because of the age distribution of their detrital zircons. A Stenian–Tonian unit (ca. 1.1–0.9 Ga) consists mainly of felsic gneisses, quartzites, calc-silicate rocks, marbles, metavolcanic rocks, and amphibolites. The metasedimentary rocks yielded detrital zircon ages clustering at ca. 1.64, 1.43, 1.3–1.2, 1.1, and 0.94 Ga with predominantly positive εHf(t) values (–7.1 to +9.7). One metavolcanic rock has an age of ca. 1110 Ma and εHf(t) values of +6.5 to +9.1. The provenance is dominated by local syndepositional arc-related igneous rocks with older detritus possibly from Laurentia, again based on the age distribution of the detrital zircons. The Central Qilian and Hualong terranes show strong affinities with the North Wulan terrane and together constituted a single coherent Qilian block prior to their involvement in the Qilian–North Qaidam orogen. The Qilian block was probably once part of the Tarim craton and had a strong linkage to South Tarim, which drifted from North Tarim during the breakup of Columbia in the early Mesoproterozoic. We suggest that, from the late Mesoproterozoic to early Neoproterozoic, the South Tarim–Qilian formed an active continental margin located close to Laurentia during the assembly of Rodinia. The final collision occurred in the early Neoproterozoic with the formation of a significant continent that included the reunified Tarim-Qilian as well as Qaidam-Kunlun and Qinling terranes, Alxa block, Kyrgyz-Chinese Tianshan, and Yili block.
Prehospital determinants of successful resuscitation after traumatic and non-traumatic out-of-hospital cardiac arrest
Authors: Barnard Ed B G , Sandbach Daniel D , Nicholls Tracy L , Wilson Alastair W , Ercole Ari
Published: April 2019

Background

Out-of-hospital cardiac arrest (OHCA) is prevalent in the UK. Reported survival is lower than in countries with comparable healthcare systems; a better understanding of outcome determinants may identify areas for improvement.

Methods

An analysis of 9109 OHCA attended in East of England between 1 January 2015 and 31 July 2017. Univariate descriptives and multivariable analysis were used to understand the determinants of survival for non-traumatic cardiac arrest (NTCA) and traumatic cardiac arrest (TCA). Two Utstein outcome variables were used: survival to hospital admission and hospital discharge.

Results

The incidence of OHCA was 55.1 per 100 000 population/year. The overall survival to hospital admission was 27.6% (95% CI 26.7% to 28.6%) and the overall survival to discharge was 7.9% (95% CI 7.3% to 8.5%). Survival to hospital admission and survival to hospital discharge were both greater in the NTCA group compared with the TCA group: 27.9% vs 19.3% p=0.001, and 8.0% vs 3.8% p=0.012 respectively.

Determinants of NTCA and TCA survival were different, and varied according to the outcome examined. In NTCA, bystander cardiopulmonary resuscitation (CPR) was associated with survival at discharge but not at admission, and the likelihood of bystander CPR was dependent on geographical socioeconomic status. An air ambulance was associated with increased survival to both hospital admission and discharge in NTCA, but only with survival to admission in TCA.

Conclusion

NTCA and TCA are clinically distinct entities with different predictors for outcome—future OHCA reports should aim to separate arrest aetiologies. Determinants of survival to hospital admission and discharge differ in a way that likely reflects the determinants of neurological injury. Bystander CPR public engagement may be best focused in more deprived areas.
Building capacity for injury prevention: a process evaluation of a replication of the Cardiff Violence Prevention Programme in the Southeastern USA
Authors: Mercer Kollar Laura M , Sumner Steven A. , Bartholow Brad , Wu Daniel T , Moore Jasmine C , Mays Elizabeth W , Atkins Elizabeth V , Fraser David A , Flood Charles E , Shepherd Jonathan P
Published: April 2019

Objectives

Violence is a major public health problem in the USA. In 2016, more than 1.6 million assault-related injuries were treated in US emergency departments (EDs). Unfortunately, information about the magnitude and patterns of violent incidents is often incomplete and underreported to law enforcement (LE). In an effort to identify more complete information on violence for the development of prevention programme, a cross-sectoral Cardiff Violence Prevention Programme (Cardiff Model) partnership was established at a large, urban ED with a level I trauma designation and local metropolitan LE agency in the Atlanta, Georgia metropolitan area. The Cardiff Model is a promising violence prevention approach that promotes combining injury data from hospitals and LE. The objective was to describe the Cardiff Model implementation and collaboration between hospital and LE partners.

Methods

The Cardiff Model was replicated in the USA. A process evaluation was conducted by reviewing project materials, nurse surveys and interviews and ED–LE records.

Results

Cardiff Model replication centred around four activities: (1) collaboration between the hospital and LE to form a community safety partnership locally called the US Injury Prevention Partnership; (2) building hospital capacity for data collection; (3) data aggregation and analysis and (4) developing and implementing violence prevention interventions based on the data.

Conclusions

The Cardiff Model can be implemented in the USA for sustainable violent injury data surveillance and sharing. Key components include building a strong ED–LE partnership, communicating with each other and hospital staff, engaging in capacity building and sustainability planning.
Public interest in gun control in the USA
Authors: Niforatos Joshua D , Zheutlin Alexander R , Pescatore Richard M
Published: April 2019

To characterise public interest in gun control in the USA using internet search queries, we undertook a cross-sectional study of the relative popularity Google Trends searchers for ‘Gun Control’, ‘Second Amendment’, ‘National Rifle Association’ and ‘Mass Shooting’ from May 2015 to December 2018. 740 weeks of data were queried. Graphed data revealed nine major inflection points. Seven of the nine (78%) major inflection points were associated with mass shootings, while two of the nine (22%) were related to political events by either the president of the USA or a presidential candidate. Our exploration of Google Trends shows the frequency of national searches related to gun control peaks with mass shootings over a 1–2-week period and then stabilises to nominal relative popularity thereafter suggesting a need to engage the public on gun control during ‘trough’ periods in order to sustain national interest and dialogue.
Changing pattern of recurrences in patients with early HER2-positive breast cancer receiving neoadjuvant chemotherapy in the era of dual anti-HER2 therapy
Authors: Chiu Joanne W , Leung Roland , Tang Vikki , Cheuk Wai Yin , Lo Jessica , Kwok Gin Wai , Wong Hilda , Suen Dacita , Cheung Polly , Wong Ting Ting , Yau Thomas , Kwong Ava
Published: April 2019

Background

Over the last 10 years, there has been a major treatment revolution for early human epidermal growth factor receptor 2 (HER2)–positive breast cancer. We aimed to explore the outcome of different neoadjuvant chemotherapy in a tertiary breast cancer centre with early HER2-positive breast cancer as well as factors associated with pathological complete response (pCR) and recurrence-free survival (RFS). The pattern of recurrence was also studied.

Methods

This retrospective study analysed the outcome of neoadjuvant chemotherapy during the period 2005 to 2016 in a tertiary referral centre in Hong Kong. Patients were divided into three groups according to the neoadjuvant chemotherapy they received: chemotherapy only (Chemo), chemotherapy plus trastuzumab (Chemo-H) and chemotherapy plus double anti-HER2 therapy (Chemo-DH).

Results

There were 226 cases analysed during the study period. The rate of pCR was 5%, 26% and 60% in Chemo, Chemo-H and Chemo-DH groups, respectively (Chemo vs pooled Chemo-H/DH: p<0.0001; Chemo-H vs Chemo-DH: p<0.0001). This was accompanied by a trend of increased rate of breast conservation therapy in Chemo-DH cohort (p=0.046). Use of double anti-HER2 therapy, older age (>50 years) and hormone receptor negativity were associated with more pCR. pCR was associated with better RFS. Among those with recurrence, the proportion of patients with brain as the only site of recurrence increased remarkably with more efficacious anti-HER2 treatment (0% in Chemo, 8% in Chemo-H, 67% in Chemo-DH).

Conclusion

pCR remains an important predictive factor for improved RFS. In the era of dual anti-HER2 neoadjuvant therapy, brain-only recurrence poses a challenge to disease surveillance and treatment.
New cost-effective pleural procedure training: manikin-based model to increase the confidence and competency in trainee medical officers
Authors: Heraganahally Subash , Mehra Sumit , Veitch Daisy , Sajkov Dimitar , Falhammar Henrik , Morton Sharon
Published: April 2019

Purpose of the study

Pleural diseases are common in clinical practice. Doctors in training often encounter these patients and are expected to perform diagnostic and therapeutic pleural procedures with confidence and safely. However, pleural procedures can be associated with significant complications, especially when performed by less experienced. Structured training such as use of training manikin and procedural skills workshop may help trainee doctors to achieve competence. However, high costs involved in acquiring simulation technology or attending a workshop may be a hurdle. We hereby describe a training model using a simple manikin developed in our institution and provide an effective way to document skill acquisition and assessment among trainee medical officers.

Study design

This was a prospective observational study. The need for training, competence and confidence of trainees in performing pleural procedures was assessed through an online survey. Trainees underwent structured simulation training through a simple manikin developed at our institute. Follow-up survey after the training was then performed to access confidence and competence in performing pleural procedures.

Results

Forty-seven trainees responded to an online survey and 91% of those expressed that they would like further training in pleural procedure skills. 81% and 85% of responders, respectively, indicated preferred method of training is either practising on manikin or performing the procedure under supervision. Follow-up survey showed improvement in the confidence and competence.

Conclusion

Our pleural procedure training manikin model is a reliable, novel and cost-effective method for acquiring competences in pleural procedures.