bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abscisic acid (ABA) sensitivity regulates desiccation tolerance in germinated Arabidopsis seeds
Authors: Maia Julio , Dekkers Bas J. W. , Dolle Miranda J. , Ligterink Wilco , Hilhorst Henk W. M. 
Published: April 2014

Summary

During germination, orthodox seeds lose their desiccation tolerance (DT) and become sensitive to extreme drying. Yet, DT can be rescued, in a well‐defined developmental window, by the application of a mild osmotic stress before dehydration. A role for abscisic acid (ABA) has been implicated in this stress response and in DT re‐establishment. However, the path from the sensing of an osmotic cue and its signaling to DT re‐establishment is still largely unknown.

Analyses of DT, ABA sensitivity, ABA content and gene expression were performed in desiccation‐sensitive (DS) and desiccation‐tolerant Arabidopsis thaliana seeds. Furthermore, loss and re‐establishment of DT in germinated Arabidopsis seeds was studied in ABA‐deficient and ABA‐insensitive mutants.

We demonstrate that the developmental window in which DT can be re‐established correlates strongly with the window in which ABA sensitivity is still present. Using ABA biosynthesis and signaling mutants, we show that this hormone plays a key role in DT re‐establishment.

Surprisingly, re‐establishment of DT depends on the modulation of ABA sensitivity rather than enhanced ABA content. In addition, the evaluation of several ABA‐insensitive mutants, which can still produce normal desiccation‐tolerant seeds, but are impaired in the re‐establishment of DT, shows that the acquisition of DT during seed development is genetically different from its re‐establishment during germination.
Discovery of pyrazines as pollinator sex pheromones and orchid semiochemicals: implications for the evolution of sexual deception
Authors: Bohman Björn , Phillips Ryan D. , Menz Myles H. M. , Berntsson Ben W. , Flematti Gavin R. , Barrow Russell A. , Dixon Kingsley W. , Peakall Rod 
Published: April 2014

Summary

Sexually deceptive orchids employ floral volatiles to sexually lure their specific pollinators. How and why this pollination system has evolved independently on multiple continents remains unknown, although preadaptation is considered to have been important. Understanding the chemistry of sexual deception is a crucial first step towards solving this mystery.

The combination of gas chromatography‐electroantennographic detection (GC‐EAD), GC‐MS, synthesis and field bioassays allowed us to identify the volatiles involved in the interaction between the orchid Drakaea glyptodon and its sexually attracted male thynnine wasp pollinator, Zaspilothynnus trilobatus.

Three alkylpyrazines and one novel hydroxymethyl pyrazine were identified as the sex pheromone of Z. trilobatus and are also used by D. glyptodon for pollinator attraction. Given that our findings revealed a new chemical system for plants, we surveyed widely across representative orchid taxa for the presence of these compounds. With one exception, our chemical survey failed to detect pyrazines in related genera. Collectively, no evidence for preadaptation was found.

The chemistry of sexual deception is more diverse than previously known. Our results suggest that evolutionary novelty may have played a key role in the evolution of sexual deception and highlight the value of investigating unusual pollination systems for advancing our understanding of the role of chemistry in evolution.
Overviewing a Nurse‐Led, Community‐Based HIV PEP Program: Applying the Extant Literature in Frontline Practice
Authors: O'Byrne Patrick , MacPherson Paul , Roy Marie , Kitson Cynthia 
Published: April 2014

AbstractThis clinical concept paper overviews a program to facilitate access to postexposure prophylaxis (PEP) for gay, bisexual, and other men who have sex with men. The project, which was a collaborative initiative involving the local School of Nursing, public health unit, AIDS service organization, hospital‐based HIV clinic, and an outpatient pharmacy, was implemented to circumvent common barriers to care identified in the literature. In this project, persons who present to one of the two participating clinics after having come, or likely having come, into contact with HIV within the previous 72 hr, are offered rapid HIV testing, also known as point‐of‐care (POC) testing, to rule out existing HIV infection, and provided with a follow‐up appointment booked at the HIV clinic. Clients are also offered comprehensive STI testing, and HIV prevention counseling. The implementation of this collaborative community‐based access‐to‐PEP project demonstrates the application of research to a real‐world health care setting, and it is hoped that others will adapt this model to their local setting, enabling ease of access to PEP for members of groups that are disproportionately affected by HIV.
A Stepwise Approach for the Management of Poisoning with Extracorporeal Treatments
Authors: Ghannoum Marc , Roberts Darren M. , Hoffman Robert S. , Ouellet Georges , Roy Louise , Decker Brian Scott , Bouchard Josée 
Published: April 2014

AbstractThe use of an extracorporeal treatment (ECTR) in a poisoned patient may be life‐saving in a limited number of scenarios. The decision‐processes surrounding the use of ECTR in poisoning is complex: most nephrologists are not trained to assess a poisoned patient while clinical toxicologists rarely prescribe ECTRs. Deciding on which ECTR is most appropriate for a poison requires a good understanding of the poison's physicochemical and pharmacokinetic properties. Further, a detailed understanding of the capabilities and limitations of the different ECTRs can be useful to select the most appropriate ECTR for a given clinical situation. This manuscript provides a stepwise approach to assess the usefulness of ECTRs in poisoning.
A depositional model for hydromagnesite–magnesite playas near Atlin, British Columbia, Canada
Authors: Power Ian M. , Wilson Sasha , Harrison Anna L. , Dipple Gregory M. , McCutcheon Jenine , Southam Gordon , Kenward Paul A. 
Published: April 2014

AbstractThis study formulates a comprehensive depositional model for hydromagnesite–magnesite playas. Mineralogical, isotopic and hydrogeochemical data are coupled with electron microscopy and field observations of the hydromagnesite–magnesite playas near Atlin, British Columbia, Canada. Four surface environments are recognized: wetlands, grasslands, localized mounds (metre‐scale) and amalgamated mounds composed primarily of hydromagnesite [Mg5(CO3)4(OH)2·4H2O], which are interpreted to represent stages in playa genesis. Water chemistry, precipitation kinetics and depositional environment are primary controls on sediment mineralogy. At depth (average ≈ 2 m), Ca–Mg‐carbonate sediments overlay early Holocene glaciolacustrine sediments indicating deposition within a lake post‐deglaciation. This mineralogical change corresponds to a shift from siliciclastic to chemical carbonate deposition as the supply of fresh surface water (for example, glacier meltwater) ceased and was replaced by alkaline groundwater. Weathering of ultramafic bedrock in the region produces Mg–HCO3 groundwater that concentrates by evaporation upon discharging into closed basins, occupied by the playas. An uppermost unit of Mg‐carbonate sediments (hydromagnesite mounds) overlies the Ca–Mg‐carbonate sediments. This second mineralogical shift corresponds to a change in the depositional environment from subaqueous to subaerial, occurring once sediments ‘emerged’ from the water surface. Capillary action and evaporation draw Mg–HCO3 water up towards the ground surface, precipitating Mg‐carbonate minerals. Evaporation at the water table causes precipitation of lansfordite [MgCO3·5H2O] which partially cements pre‐existing sediments forming a hardpan. As carbonate deposition continues, the weight of the overlying sediments causes compaction and minor lateral movement of the mounds leading to amalgamation of localized mounds. Radiocarbon dating of buried vegetation at the Ca–Mg‐carbonate boundary indicates that there has been ca 8000 years of continuous Mg‐carbonate deposition at a rate of 0·4 mm yr−1. The depositional model accounts for the many sedimentological, mineralogical and geochemical processes that occur in the four surface environments; elucidating past and present carbonate deposition.
Efficient gene targeting and removal of foreign DNA by homologous recombination in the picoeukaryote Ostreococcus
Authors: Lozano Jean‐Claude , Schatt Philippe , Botebol Hugo , Vergé Valérie , Lesuisse Emmanuel , Blain Stéphane , Carré Isabelle A. , Bouget François‐Yves 
Published: April 2014

SummaryWith fewer than 8000 genes and a minimalist cellular organization, the green picoalga Ostreococcus tauri is one of the simplest photosynthetic eukaryotes. Ostreococcus tauri contains many plant‐specific genes but exhibits a very low gene redundancy. The haploid genome is extremely dense with few repeated sequences and rare transposons. Thanks to the implementation of genetic transformation and vectors for inducible overexpression/knockdown this picoeukaryotic alga has emerged in recent years as a model organism for functional genomics analyses and systems biology. Here we report the development of an efficient gene targeting technique which we use to knock out the nitrate reductase and ferritin genes and to knock in a luciferase reporter in frame to the ferritin native protein. Furthermore, we show that the frequency of insertion by homologous recombination is greatly enhanced when the transgene is designed to replace an existing genomic insertion. We propose that a natural mechanism based on homologous recombination may operate to remove inserted DNA sequences from the genome.
The location of sites and effect of semiconductor diode trans‐scleral cyclophotocoagulation on the buphthalmic equine globe
Authors: Gemensky‐Metzler Anne J. , Wilkie David A. , Weisbrode Steven E. , Kuhn Sonia E. 
Published: April 2014

AbstractPurposeTo determine appropriate location and energy settings for trans‐scleral cyclophotocoagulation (TSCPC) for buphthalmic equine globes.AnimalsEleven horses with a buphthalmic eye blinded by glaucoma presented for enucleation.MethodsGlobe and corneal dimensions were measured via ultrasonography and calipers, andTSCPCwas performed under general anesthesia immediately prior to enucleation. Part 1: In nine globes, sixty sites were lasered 4 mm posterior to the limbus in the dorsotemporal and ventrotemporal quadrants at settings of 1500 milliwatts and 1500 ms. Globes were processed and sectioned sagitally over the temporal aspect in two blocks, each with five histologic sections examined by light microscopy. A digital imaging system was used to determine the location and length of the pars plicata on one slide from each block. Part 2: Based on results in Part 1, two globes were measured and lasered using the same time and energy settings at the following distances posterior to the limbus: 8 mm dorsally, 6 mm dorsotemporally, 5 mm ventrotemporally, and 5 mm ventrally.ResultsGlobe and corneal dimensions exceeded normal values in all globes. Part 1: In all nine globes, photocoagulation affected the anterior ciliary processes and iris base and in 8/9 coagulation of the pectinate ligaments was noted. Part 2: In both globes, coagulation was confined to the pars plicata.ConclusionsThe previously recommendedTSCPCsites are located too far anteriorly for a buphthalmic globe. Buphthalmic equine globes should haveTSCPCperformed at the following distances posterior to the limbus: 6–8 mm dorsally, 5–6 mm dorsotemporally, 4–5 mm ventrotemporally, and 4–5 mm ventrally.
The Use of Direct‐Fed Microbials to Reduce Shedding of Escherichia coli O157 in Beef Cattle: A Systematic Review and Meta‐analysis
Authors: Wisener L. V. , Sargeant J. M. , O'Connor A. M. , Faires M. C. , Glass‐Kaastra S. K. 
Published: April 2014

SummaryHuman illness due to infections with Escherichia coli O157 is a serious health concern. Infection occurs through direct contact with infected animals or their faeces, through contaminated food or water and/or through person‐to‐person transmission. A reduction in faecal E. coli O157 shedding in cattle might reduce the burden of human infections. We used systematic review and meta‐analysis to assess the efficacy of direct‐fed microbials (DFM), compared with placebo or no treatment, fed during the pre‐harvest stage of production in reducing faecal E. coli O157 shedding in beef cattle during field trials. Four electronic databases, Nebraska Beef Reports and review article reference lists were searched. A total of 16 publications assessing faecal shedding at the end of the trial and/or throughout the trial period were included. The majority of publicly disseminated trials evaluated the prevalence of E. coli O157 faecal shedding; only two evaluated the concentration of organisms in faeces. The prevalence of faecal E. coli O157 shedding in cattle is significantly reduced by DFM treatments (summary effect size for all DFM – OR = 0.46; CI = 0.36–0.60). The DFM combination Lactobacillus acidophilus (NP51) and Propionibacterium freudenreichii (NP24) was more efficacious in reducing the prevalence of faecal E. coli O157 shedding at the time of harvest and throughout the trial period compared with the group of other DFM, although this difference was not statistically significant. Furthermore, we found that the combination [NP51 and NP24] treatment was more efficacious in reducing the prevalence of faecal E. coli O157 shedding at the time of harvest and throughout the trial period when fed at the dose of 109 CFU/animal/day than any lesser amount, although this difference was not statistically significant. Feeding beef cattle DFM during the pre‐harvest stage of production reduces the prevalence of E. coli O157 faecal shedding and might effectively reduce human infections.
Experimental Investigations Into the Finishing Force and Torque in Magnetic Abrasive Finishing Process
Authors: Mulik R. S. , Pandey P. M. 
Published: April 2014

Magnetic abrasive finishing (MAF) is a finishing process in which surface is finished by removing the material in the form of micro-chips by the magnetic and abrasive particles in the presence of a magnetic field. In a finishing process, forces have direct influence on the generation of finished surface and accuracy of the workpiece.
The magnitude of force or torque is also of importance as the surface integrity is affected. In the present research work, new design of electromagnet which gave relatively lesser force and torque as compared to conventional annular electromagnet was used to perform MAF. The measurements of normal force and finishing torque were carried out at different processing conditions using Kistler’s dynamometer and were found in the order of 24 N and 8 Nm respectively. The experiments were planned using Taguchi’s L16 orthogonal array and supply voltage to electromagnet, rpm of electromagnet, finishing gap and abrasive weight percentage at four levels were considered as process parameters. Supply voltage to the electromagnet and finishing gap were found to be the significant factors affecting finishing force and torque in this work. The scanning electron microscopy (SEM) study of the finished workpiece showed that there was no surface or subsurface damage due to very low finishing force and torque.
Productivity Theory for Industrial Automated Lines
Authors: Usubamatov Ryspek , Sin Tan Chan , Hamzas Mohd Fidzwan B. Md. Amin 
Published: April 2014

The basic attributes of any industrial machines and systems are productivity rate and quality of products. Attributes of productivity are related to the theory of reliability let alone the theory of efficiency of machines. Publications in area of productivity of the industrial systems enable to write the productivity theory for the industrial machines and systems. This theory shows the links between productivity, reliability, technological and technical parameters and the structure of machines with complex designs. Automated production lines are considered industrial systems for the collection of serial and parallel stations arranged according to a certain structure that depends on a technological process of machining parts. Manufacturers require correct and clear mathematical models to calculate the productivity of the automated lines with high accuracy.
The mathematical models for productivity rate of industrial systems with complex design define their structures according to the level of output. This paper presents an analytical approach to the productivity rate of automated lines with stations and mechanisms that display different failure rates and processing times. The typical designs of industrial automated lines are considered by three types of structure: multi-station ’s automated line of serial, parallel action and serial-parallel action. All designs can be presented using linear, circular and rotary arrangements. The analytical equations allow for the output of the automated lines to be modeled with different failure rates for the stations and mechanisms yielding results close to the actual productivity values.
Product Innovation Needs Improved Design Process of Screw Joints
Authors: Friedrich C. , Hubbertz H. 
Published: April 2014

An essential task in today’s engineering is to realize a multifunctional design which needs an optimization process to achieve highest performance (load profile), minimized energy consumption (fuel, gas, electricity in production and life time of product) and maximized sustainability (during entire life cycle from idea to end of life) at an affordable prize in combination. Another point is that the performance of products is increased steadily up to now, which shifts the load profile towards higher peak loads.
Consequently, a related design methodology is necessary which takes into account modern techniques of CAD (Computer Aided Design) and FEA (Finite Element Analysis) besides analytical engineering calculation and testing. Also the inclusion of nontechnical aspects must be possible (e.g. experience, rating of economy). Besides this the local stressing, time dependency and non-linear behavior must be considered in more detail; examples are proposed below.
This methodology can be illustrated very well for the example of screw joints in products with high mechanical loading between components. Established technical literature mainly refers to pure technical aspects of bolted joints, e.g. [1, 2, 3].
Another important aspect for modern products is the increased use of mechatronic functions (mechanical system added by sensors, actuators and controller as well as controlling software). These functions raise the variety of failure modes significantly, which requires improved reliability. The paper describes, how screw joints are affected, because the number of screw joints increases and that engineers have to use reliable design methods to develop robust products. Looking to the packaging of mechatronic products, smaller screws joints are used because of space restrictions coming from the high number of components. In the end this means higher stressing of smaller screws. Countersunk heads offer benefits regarding space requirements, but need to consider positioning tolerances.
For optimization process always non-linear relations are challenging; they need special description of the mechanisms and increase the demand for quality of the optimization method (e.g. convergence of numerical methods).
Conclusions from this result in fastening perspectives for the design of innovative products for the future (automation of engineering design for fast product development considering complex interactions).
Temperature-Supported Forming of Automobile Related Magnesium Components
Authors: Schieck Frank , Drossel Welf-Guntram , Bräunlich Hans , Scheffler Sören , Pierschel Norbert 
Published: April 2014

Lightweight design in passenger cars is gaining more and more importance. Independent from conventionally or electrically drive train concepts, weight reduction is one of the most rated defining variables for fuel or energy consumption, thus affecting the range of the vehicle. Overall, the potential for using steel in lightweight bodywork construction has attained a high level of development with the result that the potential for further optimisation is increasingly diminishing. As a consequence, alternative lightweight construction materials are set to become more important in the future.
Compared to the beneficial application potential regarding bending and distortion of steel- and Aluminium compared to Magnesium blanks, this material becomes more and more interesting for automobile applications.
Beside challenges like corrosion and recycling, mainly an appropriate forming technology lies in the focus of investigations. Due to the insufficient forming conditions of Magnesium at room temperature the focus of investigation was related to the characterisation of material properties depending on temperature, the thermo-mechanical forming simulation for process and tool design and the practical realisation of complex, car-related part geometries as well as requirements for forming tools and additional devices.
In the following article we will present the results of studies into the forming of magnesium sheets (AZ31) including tailored blanks, achieved within a growth cell (TeMaK and TeMaK+).
Predictive Modeling of Surface Microstructure of Hardened Steel Subject to Drilling
Authors: Shen Ninggang , Ding Hongtao , Li Wei 
Published: April 2014

Hole surface microstructures are very critical to the mechanical performance and fatigue life of metallic products from drilling processes. When steel material is drilled at a fully hardened condition, hole surface microstructures are often subject to transition because of the intense thermo-mechanical loading in the drilling process. A white layer can be formed on the surface of a drilled hole of carbon steels with high matrix hardness. The formation of the white layer mainly results from two reasons: thermally driven phase transformation and mechanical grain refinement due to severe plastic deformation on the machined surface.
In this study, a multi-step numerical analysis is conducted to investigate the potential mechanism of surface microstructure alterations in the drilling process of hardened steels. First, three-dimensional (3D) Finite Element (FE) simulations are performed using a relative coarse mesh with AdvantEdge for hard drilling of AISI 1060 steel to achieve the steady-state solution for thermal and deformation fields. Defining the initial condition of the cutting zone using the previous 3D simulation results, a multi-physics model is then implemented in two-dimensional (2D) coupled Eulerian-Lagrangian (CEL) finite element analysis in ABAQUS to model both phase transformation and grain refinement at a fine mesh to comprehend the surface microstructure alteration. The interaction among surface microstructures, drilling parameters and the hardness of the workpiece material are studied simultaneously. With the comparison to related experimental results, the capabilities of the multi-physics model to accurately predict critical surface microstructural attributes such as phase compositions, grain size, and microhardness during the drilling of carbon steel are demonstrated.