24,296 research outputs found
Evaluation of a double Gimbal IPACS design
The suitability of various integrated power/attitude control systems (IPACS) rotor materials was analyzed. Three materials were investigated: (1) 6A1-4V-Titanium (the current IPACS rotor material); (2) B120 VCA Titanium; and (3) Custom 455 stainless steel. The preliminary linear vibration analysis was updated to include the weights and stiffnesses of the gimbals design. A belleville washer spring preload mechanism was designed to replace the existing helical spring and interference fit preload mechanism
A Gimbal sizing analysis for an IPACS rotating assembly
All major components of an integrated power/attitude control system (IPACS) assembly were analyzed for testing, launch, and operational stresses. The conceptual design for the outer gimbal and mounting ring structures were developed and analyzed along with preliminary designs of the pivot and torquer assemblies. Results from the system response analysis and the thermal analysis are also presented. Gimballing of this rotating assembly should present few difficulties as the maximum gimballing rate is quite low. However, the inner gimbal assembly in its current configuration must be modified to develop the system from a laboratory concept to a realistic flight hardware status
Patent Landscape of Helminth Vaccines and Related Technologies
Executive Summary This report focuses on patent landscape analysis of technologies related to vaccines targeting parasitic worms, also known as helminths. These technologies include methods of formulating vaccines, methods of producing of subunits, the composition of complete vaccines, and other technologies that have the potential to aid in a global response to this pathogen. The purpose of this patent landscape study was to search, identify, and categorize patent documents that are relevant to the development of vaccines that can efficiently promote the development of protective immunity against helminths. The search strategy used keywords which the team felt would be general enough to capture (or “recall”) the majority of patent documents which were directed toward vaccines against helminths. After extensive searching of patent literature databases, approximately 2847 publications were identified and collapsed to about 446 INPADOC families. Relevant patent families, almost half of the total relevant families (210 being total number of relevant families), were then identified and sorted into the categories of trematodes, cestodes, nematodes or nonspecific helminth. The 210 patent families that were divided into these four major categories were then further divided into sub categories relating to common fields of technology (e.g. DNA vaccine, vaccine formulations, methods to produce subunits) This sorting process increased the precision of the result set. The four major categories (cestodes, nematodes, trematodes, and non specific applications) as well as the overall data set of the 210 relevant family members were subjected to a range of analytics in order to extract as much information as possible from the dataset. First, patent landscape maps were generated to assess the accuracy of the sorting procedure and to reveal the relationships between the various technologies that are involved in creating an effective vaccine. Then, filings trends are analyzed for the overall dataset of the 210 relevant families as well as by the categories of trematodes, cestodes, and nematodes. The country of origin each member of the 210 relevant families was determined, and the range of distribution to other jurisdictions was assessed. Filings were also analyzed by year, by assignee. Finally, the various patent classification systems were mapped to find which particular classes tend to hold helminth vaccine-related technologies. Besides the keywords developed during the searches and the landscape map generation, the classifications represent an alternate way for further researchers to identify emerging helminth vaccine technologies. The analysis included creation of a map of keywords describing the relationship of the various technologies involved in the development of helminth vaccines. The map has regions corresponding to plasmids and other gene based technologies used in DNA vaccines for Japonicum Schistosoma. Important technologies listed on the map include the use of reverse genetics to create reassorted viruses targeted for the use in veterinary applications. Additionally, the map suggests that numerous subunits exist for use in vaccines targeting cestodes, trematodes, and nematodes. Another major finding was that the number of patent documents related to helminths being published has been steadily increasing in the last decade, as shown in the figure below. Until the early-1990s, there were only a few helminth vaccine related patent documents being published each year. The number of publications increased noticeably when TRIPS took effect, resulting in publication of patent applications. However, since 2006 the number of vaccine publications has exploded. In the years 2011 and 2012, about 23 references disclosing parasitic worm vaccine technologies were published each year. Thus, interest in developing new and more efficacious helminth vaccines has been growing in recent years. The origin of the vaccine-related inventions was also analyzed. The team determined the country in which the priority application was filed, which was taken as an indication of the country where the invention was made or where the inventors intended to practice the invention. By far, most of the relevant families originated with patent applications filed in the United States and China. Other prominent priority countries were the United Kingdom, Japan, Brazil, Australia and France. Countries with the most filings were also analyzed. Countries that were heavily targeted for patent filings included the United States, Australia, Canada, and New Zealand. Top assignees for these families were mostly large pharmaceutical companies, with the majority of patent families coming from Heska, followed by Merck & Co., Institute Pasteur, AusBiotech Biotechnology, and Biological Sciences Research Council. Lastly, the jurisdictions were inventors have sought protection for their vaccine technologies were determined, and the number of patent families filing in a given country is plotted on the world map shown (Fig. 25). The United States, Canada, Australia, Japan, New Zealand and France have the highest level of filings, followed by Germany, Brazil, India, United Kingdom and Spain. However, although there are a significant number of filings in Brazil, the remainder of Central and South America has only sparse filings. Of concern, with the exception of South Africa, few other African nations have a significant number of filings. In summary, the goal of this report is to provide a knowledge resource for making informed policy decisions and for creating strategic plans concerning the assembly of vaccines targeting highly prevalent helminth infections. The ITTI team has defined the current state of the art of technologies involved in the manufacture of helminth vaccines, and the important assignees, inventors, and countries have been identified. This document should aid in evaluating the current state of vaccines technologies targeting helminths and the potential outgrows of these technological fields. Furthermore, as this report illustrates, the steady increase in helminth patenting, expanded diversity of assignees and greater global filings, indicates that intellectual property protection does not inhibit the development of crucial innovations for this class of neglected diseases, but, on the contrary, appears to be a driver of accelerated research and development
A Component Based Heuristic Search Method with Evolutionary Eliminations
Nurse rostering is a complex scheduling problem that affects hospital
personnel on a daily basis all over the world. This paper presents a new
component-based approach with evolutionary eliminations, for a nurse scheduling
problem arising at a major UK hospital. The main idea behind this technique is
to decompose a schedule into its components (i.e. the allocated shift pattern
of each nurse), and then to implement two evolutionary elimination strategies
mimicking natural selection and natural mutation process on these components
respectively to iteratively deliver better schedules. The worthiness of all
components in the schedule has to be continuously demonstrated in order for
them to remain there. This demonstration employs an evaluation function which
evaluates how well each component contributes towards the final objective. Two
elimination steps are then applied: the first elimination eliminates a number
of components that are deemed not worthy to stay in the current schedule; the
second elimination may also throw out, with a low level of probability, some
worthy components. The eliminated components are replenished with new ones
using a set of constructive heuristics using local optimality criteria.
Computational results using 52 data instances demonstrate the applicability of
the proposed approach in solving real-world problems.Comment: 27 pages, 4 figure
Ejaculate allocation by male sand martins, Riparia riparia
Males of many species allocate sperm to ejaculates strategically in response to variation in the risk and intensity of sperm competition. The notable exception is passerine birds, in which evidence for strategic allocation is absent. Here we report the results of a study testing for strategic ejaculate allocation in a passerine bird, the sand martin (Riparia riparia). Natural ejaculates were collected from males copulating with a model female. Ejaculates transferred in the presence of a rival male contained significantly more sperm than ejaculates transferred in the absence of a rival male. There was no evidence that this difference was due to the confounding effects of the year of ejaculate collection, the identity of the model female, the colony, the stage of season or the period of the day in which ejaculates were collected. A more detailed examination of the ejaculate patterns of individual males, achieved by the DNA profiling of ejaculates, provided additional evidence for strategic allocation of sperm
Services within a busy period of an M/M/1 queue and Dyck paths
We analyze the service times of customers in a stable M/M/1 queue in
equilibrium depending on their position in a busy period. We give the law of
the service of a customer at the beginning, at the end, or in the middle of the
busy period. It enables as a by-product to prove that the process of instants
of beginning of services is not Poisson. We then proceed to a more precise
analysis. We consider a family of polynomial generating series associated with
Dyck paths of length 2n and we show that they provide the correlation function
of the successive services in a busy period with (n+1) customers
Occasional essay: upper motor neuron syndrome in amyotrophic lateral sclerosis
The diagnosis of amyotrophic lateral sclerosis (ALS) requires recognition of both lower (LMN) and upper motor neuron (UMN) dysfunction.1 However, classical UMN signs are frequently difficult to identify in ALS.2 LMN involvement is sensitively detected by electromyography (EMG)3 but, as yet, there are no generally accepted markers for monitoring UMN abnormalities,4 the neurobiology of ALS itself, and disease spread through the brain and spinal cord,.5 Full clinical assessment is therefore necessary to exclude other diagnoses and to monitor disease progression. In part, this difficulty regarding detection of UMN involvement in ALS derives from the definition of ‘the UMN syndrome’. Abnormalities of motor control in ALS require reformulation within an expanded concept of the UMN, together with the neuropathological, neuro-imaging and neurophysiological abnormalities in ALS. We review these issues here
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