An improved power threshold method for estimating tool wear during milling

It is well known that cutting forces increase as a cutting tool wears out. Current commercially available Tool Condition Monitoring (TCM) systems use this fact to set a threshold for the allowable percent power increase corresponding to a worn out tool. Typically, a training process is required whereby the first few parts cut with a sharp tool provide a baseline for comparison. This method works well when making large numbers of the same part with a single tool but is not as useful when making a single part or when the tool life is shorter than the time required to make a single part. The goal of this research is to develop a TCM system that can estimate tool wear without the necessity of a training process and in the presence of different modes of tool wear. Our hypothesis is that tool wear can be accurately correlated with the coefficients of a tangential cutting force model. The model coefficients are estimated by online measurement of spindle motor power. One of the model coefficients (Ktc) relates cutting forces to chip thickness. The other coefficient (Kte) relates to rubbing or edge forces. Research results indicate that Kte correlates well with flank wear while Ktc is a good indicator of edge chipping. A number of experiments are performed with helical flat end mills made of High Speed Steel (HSS) and carbide tools cutting 1018 steel. Spindle motor power is used to calibrate the model coefficients at periodic intervals. Generally, the percent power increase at tool failure is much higher when flank wear is the dominant mode. Tool wear is estimated based on a weighted combination of the two model coefficients thereby establishing a threshold that is independent of the combination of chipping and flank wear. Preliminary research was also performed to explore the potential of using a contact microphone mounted to the spindle for TCM. A contact microphone can provide frequency information based on the vibrations as well as relate the RMS value to cutting power

The significance of macroalgae to the diets of juvenile fish and ecosystem function in a tropical coral reef lagoon

Little information is available on the contribution of macroalgae to the food web of the Ningaloo lagoon and its importance in the diets of fish associated with it. This information is important for understanding potential trophic flows from macroalgae to juvenile fish and provides the fundamental data for constructing ecosystem models. In my Honours research, I have examined: the significance of macroalgae, its associated epibionts and infauna in the diets of juvenile and subadult fish in the Ningaloo lagoon, focussing on: 1. the significance of macroalgae in the diets of juvenile fish and how this varies between summer (February) and winter (July) (Chapter 3); and 2. the development and use of an Ecopath with Ecosim ecosystem model to assess trophic flows of macroalgae to functional fish groups (Chapter 4). Fish were sampled in macroalgal beds by a variety of techniques (herding into fence nets by SCUBA, hand spear, and rod and line fishing) in February and July, 2015. A total of 181 fish were caught representing 11 species, with six species caught in both months. Stomach contents were identified to the lowest taxonomic resolution possible and the percent volume of items recorded. Multivariate analyses were used to identify guilds (species with similar diets), and to assess differences in diets between February and July. The results showed that: fleshy macroalgae (e.g. Sargassum spp.) were not as important as filamentous algae to the diets of the juveniles of two nominally herbivorous fish species in February, but became more important in July. Macroalgae were not an important component in the diets of juvenile Lethrinidae, Lutjanidae, or Mullidae, though the infauna associated with the macroalgal beds was important in the diets. Analysis of feeding specialisation found that the smaller size classes of fish in February had a narrower trophic width and a more specialised feeding strategy than larger bodied fish of the same species in July. At this time, fish tended to show a generalist feeding strategy and broad niche width, possibly associated with increasing gape size of the larger fish sampled at this time. These studies provided the basis for defining three distinct functional feeding groups for the Ecopath model: herbivores, zoobenthivores, and carnivores (Chapter 4). The Coral Bay Ecopath model was constructed by modifying an Ecopath model for the Ningaloo system and applying it to an area of the macroalgal beds to examine trophic flows from macroalgae to higher trophic levels. The Coral Bay model had 29 functional groups based on the functional fish feeding groups (adults and juveniles of herbivores, zoobenthivores, carnivore, Lethrinus species and Lethrinus nebulosus - 10 groups) and broad dietary categories (13 groups) identified in Chapter 3, a competitor for algal resources (e.g. turtles - 1 group), predators to the fish groups (e.g. reef sharks and dolphins - 2 groups) and extra groups that were included due to having different functional roles (e.g. phytoplankton, squid and octopus - 3 groups). The model was balanced by adjusting biological parameters, with an emphasis on changing those with the fewest data from the region the most. Macroalgae were the dominant primary producers in the system, and comprised more than 70% of the total consumption of trophic level I groups. Ecopath with Ecosim was used to evaluate the effects of three categories of disturbance, (17 scenarios), affecting primary production, fishing effort and simultaneous changes in both primary production and fishing effort. The results from these predicted that changes in the rate of primary production had a much larger effect on the biomass of functional groups within the Ningaloo lagoon than changes to fishing effort. Since this model was developed with a focus on trophic understanding and not fishing, and it was not possible to tune the model with data from recreational fisheries, therefore, the predictions from the scenarios involving fishing effort should be treated with caution. The results from this study show that the macroalgal beds are important in the diets of some fish species and contribute to trophic flows in the Ningaloo lagoon. This adds to the understanding of their function as habitat for different species and highlights the value of including them in conservation planning for the Ningaloo Marine Park

Alien Registration- Paradis, Delia (Lewiston, Androscoggin County)

https://digitalmaine.com/alien_docs/29704/thumbnail.jp

Some effects of Machiavellianism and change of leaders on group productivity.

Business AdministrationDoctor of Philosophy (Ph.D.

Alien Registration- Desfosses, Gabriel D. (Lewiston, Androscoggin County)

https://digitalmaine.com/alien_docs/29705/thumbnail.jp

Fracture-of the Calcaneum:

n/

Stratégiaváltás az Ikarusz-nál - amerikai szemmel

Az esettanulmány jellegű írás "külföldi szemmel" tekinti át az IKARUSZ közelmúltját, s a stratégiaváltással kapcsolatosan felmerülő, meglehetősen széles problémakört

Analyse d'images de microscopie électronique de biopolymères hélicoïdaux flexibles

Flexible helical protein polymers exemplified by actin filaments, microtubules and bacterial flagella areubiquitous in biology. Due to their size and intrinsic irregularities, the structure of these polymers cannot be solved by Xraycrystallography. Since half a century, three-dimensional (3D) reconstruction from two-dimensional (2D) ElectronMicroscopy (EM) images appears as a method of choice to solve the structure of large helical polymers. However,depending on the degree of flexibility of the analyzed helices, the 3D reconstruction process can still be a daunting task.For the most regular helices, the classical reciprocal space-based Fourier-Bessel approach can allow both to determinethe helical symmetry and to calculate 3D structures. For more flexible structures, recent “single-particle” approachesconsist in segmentation of long irregular helices into short (i.e. locally more regular) segments and their processing asasymmetrical objects with defined symmetry-imposed constraints (Egelman, 2000; Sachse et al., 2007). However, twomajor difficulties remain: the heterogeneous data must be sorted into homogeneous populations and the helical symmetryfor each population has to be determined. In the presented work, we explored various single-particle approaches,developed new analysis methods, and implemented most of them into a user-friendly processing pipeline. The targetbiological objects were helical nucleocapsids of two negative strand RNA viruses, Measles (MeV) and VesicularStomatitis Virus (VSV ; the prototype for Rabies), the latter being particularly flexible in terms of helical parameters(diameter, number of subunits per turn). Nucleocapsids are formed by the viral genomic RNA coated by thenucleoprotein and serve as a template for viral replication and transcription. To overcome the heterogeneity problem, weused 2D classification, described general processing protocols and applications for helical segments, and introduced anew classification method based on the power spectra of the images. The determination of helical symmetry(ies) wasaddressed by a novel approach relying on ab initio exhaustive search of helical parameters whereby we start from asingle 2D image, reconstruct as many 3D structures as parameters to test by cropping the image and assigning views tothe obtained segments, and calculate the cross-correlation (CC) of the reprojection of the 3D model with the initialimage. Applied to artificial data sets, the method was effectively able to detect a maximum of CC for the true symmetryparameters, but also showed intrinsic ambiguities of helical symmetry determination on which we extensively comment.Altogether, the result of this method-oriented work allowed us to address several biological questions. First, the 3Dreconstruction by negative stain EM of two forms of nucleocapsids of MeV coupled to a docking of a homologouscrystal structure enabled us to determine the orientation of the nucleoprotein and of the RNA in the nucleocapsids.Secondly, we assessed the structure of in vitro formed nucleocapsids of VSV and showed that assemblies close to thenative viral nucleocapsids can be formed in the absence of any other viral proteins, thus providing new insights into theassembly of this virus. As a perspective of this work, our pipeline of flexible helical analysis is being extended andsuccessfully used for other projects.Le virus de la Rougeole reste le plus meurtrier des virus contre lesquels il existe un vaccin, avec environ 350000 décès par an dans le monde. Ce virus appartient à la famille des Paramyxoviridae, qui sont des virus enveloppés de forme sphérique dont le génome est composé d’un seul brin d’ARN de polarité négative. L’élément central de la réplication et de la transcription du génome viral est le complexe, de forme hélicoïdale, entre l’ARN du virus et la nucléoprotéine. Cette association intime appelée nucléocapside a des propriétés étonnantes non encore élucidées. En effet, l’ARN des virus à ARN négatif a la particularité de n’être jamais nu, même lors des étapes de réplication/transcription nécessitant pourtant le passage de la polymérase virale. On suppose que l’interaction avec la phosphoprotéine, cofacteur de la polymérase, provoque un changement de la conformation de la nucléoprotéine pour rendre l’ARN viral accessible à la polymérase. Lorsque la nucléoprotéine est exprimée dans des cellules d’insectes, elle se fixe aux ARNs cellulaires et forme des nucléocapsides recombinantes. Les études précédentes sur d’autres virus à ARN négatif (Rage, Marbourg, Sendaï) ont montré que les nucléocapsides recombinantes sont semblables aux nucléocapsides virales. Au sein de la nucléocapside, le domaine C-terminal de la nucléoprotéine joue un rôle crucial en interagissant avec de nombreux partenaires viraux et cellulaires, notamment avec la phosphoprotéine dans les étapes de réplication/transcription du génome viral. Cependant, des observations en microscopie électronique à transmission avaient montré que les nucléocapsides recombinantes contenant la nucléoprotéine entière était trop flexibles pour envisager leur reconstruction tridimensionnelle par analyse d’image, ce qui avait conduit à les rigidifier par un traitement protéasique dont l’effet latéral est justement l’élimination du domaine C-terminal de la nucléoprotéine. Nous avons mis au point des conditions de préparation en coloration négative permettant de rigidifier la nucléocapside intacte, afin d’en calculer une reconstruction tridimensionnelle à basse résolution et de la comparer avec celle de la nucléocapside protéolysée. Nous avons ainsi montré que les nucléocapsides de la Rougeole changeaient radicalement de structure tridimensionnelle en réponse au traitement protéolytique, non seulement en terme de pas de l’hélice ou de nombre de sous-unités par tour, mais aussi au niveau de la conformation de la nucléoprotéine et de ses contacts avec les sous-unités adjacentes, ce qui n’avait encore jamais été observé aussi clairement

Ensembl regulation resources

New experimental techniques in epigenomics allow researchers to assay a diversity of highly dynamic features such as histone marks, DNA modifications or chromatin structure. The study of their fluctuations should provide insights into gene expression regulation, cell differentiation and disease. The Ensembl project collects and maintains the Ensembl regulation data resources on epigenetic marks, transcription factor binding and DNA methylation for human and mouse, as well as microarray probe mappings and annotations for a variety of chordate genomes. From this data, we produce a functional annotation of the regulatory elements along the human and mouse genomes with plans to expand to other species as data becomes available. Starting from well-studied cell lines, we will progressively expand our library of measurements to a greater variety of samples. Ensembl's regulation resources provide a central and easy-to-query repository for reference epigenomes. As with all Ensembl data, it is freely available at http://www.ensembl.org, from the Perl and REST APIs and from the public Ensembl MySQL database server at ensembldb.ensembl.org.Database URL: http://www.ensembl.org.Wellcome Trust grant: (WT098051); National Human Genome Research Institute grants: (U41HG007234, 1U01 HG004695); Biotechnology and Biological Sciences Research Council grant: (BB/L024225/1); European Molecular Biology Laboratory; European Union’s Seventh Framework Programme; European Research Council

International Workshop on Recreational Fishing Surveys

Recreational fishing surveys have been conducted by the Department of Primary Industries and Regional Development (DPIRD, formerly Department of Fisheries) since 1975 (Tate et al., 2020). Within Western Australia, the first international workshop on recreational fishing surveys was held in January 2010 at the Western Australian Fisheries Marine Research Laboratories in Perth. The workshop aimed to audit existing survey methods and make recommendations for the design of integrated surveys to estimate recreational fishing harvest, catch and effort at statewide and bioregional scales (Wise & Fletcher 2013)