448 research outputs found
Interaction with nanoscale topography: Adhesion quantification and signal transduction in cells of osteogenic and multipotent lineage
No full textPolymeric medical devices widely used in orthopedic surgery play key roles in fracture fixation and orthopedic implant design. Topographical modification and surface micro-roughness of these devices regulate cellular adhesion, a process fundamental in the initiation of osteoinduction and osteogenesis. Advances in fabrication techniques have evolved the field of surface modification; in particular, nanotechnology has allowed the development of nanoscale substrates for the investigation into cell-nanofeature interactions. In this study human osteoblasts (HOBs) were cultured on ordered nanoscale pits and random nano craters and islands. Adhesion subtypes were quantified by immunofluorescent microscopy and cell-substrate interactions investigated via immuno-scanning electron microscopy. To investigate the effects of these substrates on cellular function 1.7 k microarray analysis was used to establish gene profiles of enriched STRO-1+ progenitor cell populations cultured on these nanotopographies. Nanotopographies affected the formation of adhesions on experimental substrates. Adhesion formation was prominent on planar control substrates and reduced on nanocrater and nanoisland topographies; nanopits, however, were shown to inhibit directly the formation of large adhesions. STRO-1+ progenitor cells cultured on experimental substrates revealed significant changes in genetic expression. This study implicates nanotopographical modification as a significant modulator of osteoblast adhesion and cellular function in mesenchymal populations
Energy managed reporting for wireless sensor networks
No full textIn this paper, we propose a technique to extend the network lifetime of a wireless sensor network, whereby each sensor node decides its individual network involvement based on its own energy resources and the information contained in each packet. The information content is ascertained through a system of rules describing prospective events in the sensed environment, and how important such events are. While the packets deemed most important are propagated by all sensor nodes, low importance packets are handled by only the nodes with high energy reserves. Results obtained from simulations depicting a wireless sensor network used to monitor pump temperature in an industrial environment have shown that a considerable increase in the network lifetime and network connectivity can be obtained. The results also show that when coupled with a form of energy harvesting, our technique can enable perpetual network operatio
The use of nanoscale topography to modulate the dynamics of adhesion formation in primary osteoblasts and ERK/MAPK signalling in STRO-1+enriched skeletal stem cells
No full textThe physiochemical characteristics of a material with in vivo applications are critical for the clinical success of the implant and regulate both cellular adhesion and differentiated cellular function. Topographical modification of an orthopaedic implant may be a viable method to guide tissue integration and has been shown in vitro to dramatically influence osteogenesis, inhibit bone resorption and regulate integrin mediated cell adhesion. Integrins function as force dependant mechanotransducers, acting via the actin cytoskeleton to translate tension applied at the tissue level to changes in cellular function via intricate signalling pathways. In particular the ERK/MAPK signalling cascade is a known regulator of osteospecific differentiation and function. Here we investigate the effects of nanoscale pits and grooves on focal adhesion formation in human osteoblasts (HOBs) and the ERK/MAPK signalling pathway in mesenchymal populations. Nanopit arrays disrupted adhesion formation and cellular spreading in HOBs and impaired osteospecific differentiation in skeletal stem cells. HOBs cultured on 10 ?m wide groove/ridge arrays formed significantly less focal adhesions than cells cultured on planar substrates and displayed negligible differentiation along the osteospecific lineage, undergoing up-regulations in the expression of adipospecific genes. Conversely, osteospecific function was correlated to increased integrin mediated adhesion formation and cellular spreading as noted in HOBS cultured on 100 ?m wide groove arrays. Here osteospecific differentiation and function was linked to focal adhesion growth and FAK mediated activation of the ERK/MAPK signalling pathway in mesenchymal populations.<br/
Letter dated 30 January 1967 from Lorenzo Richards to A. G. ("Geoff") Norman
No full textLetter dated 20 January 1967 from A. G. Norman at the University of Michigan to Lorenzo A. Richards at the U.S. Salinity Laboratory in Riverside, California, wishing him well on his retirement and inviting him to write an article for the next volume of \u27Advances in Agronomy,\u27 for which Norman was editor; and Richards\u27 reply dated 30 January 1967January 30, 1967 Br. A. G. Norman Administration Bldg. University of Michigan Ann Arbor, Michigan 48104 Dear Geoffs It was pleasant to receive your letter of 20 January 196? and your kind words and good wishes are much appreciated. I retired from USDA on 1 May 1906 and have been enjoying myself very much since then* I still have a hangover from the Agronomy Society, but that won\u27t last forever. I have just taken up again my old hobby of automatic irrigation and I am working on some new types of irrigation controls. Iwwish to congratulate you on your long and expert guidance of "ADVANCES IN AGRONOMY". Ton deserve great appreciation from the profession, in spite of all the headaches you have caused the poor authors* I am honored to he invited to participate in the final volume, but age brings some wisdom, and I am inolined to he wary* I have been thinking about some kind of a paper on "the leeching requirement". This would he of the nature of a review and might be suitable. X am thinking somewhat about textbook material and so would be concerned about copyrights and possible private later use of the material. Can you give me information en academic press policy in this regard? I am thinking of a length some* thing like 20 or 30 double-spaced typewritten pages. If the closing date for manuscripts is November 1967* what vould be estimated time for issuing the published volume? I am enclosing some ligfrt reading for Marian in case she happens to be an agronomist\u27s wife with a green thumb. Leeching requirement principle applies with the same inexorability to ornamental pot in an Ann Arbor sun room as to Imperial Valley. I called Anthony by telephone the other night to find that he and family are well and happy. Thewports I get indicate that he is a respected member of the department. We threaten each other court proceedings occasionally, but my attention to tennis has lagged recently. Sincerely, L. A. Richards Physicist LARjgb Encl. ADVANCES IN AGRONOMY PREPARED UNDER THE AUSPICES OF THE AMERICAN SOCIETY OF AGRONOMY E D I T O R: A. G. NORMAN ADMINISTRATION BLDG. THE UNIVERSITY OF MICHIGAN ANN ARBOR, MICHIGAN 48T04 TELEPHONE; 764-1185 P U B L I S H E R S : ACADEMIC PRESS INC. 111 FIFTH AVENUE NEW YORK, NEW YORK 1OO03 TELEPHONE; OREGON 7-6713 January 20, 1967 Dr. L. A. Richards U. S. Salinity Laboratory Riverside, California Dear Ren: Sometime ago I heard, to my surprise, that you had retired from the laboratory. I am presuming, however, that your name is sufficiently well remembered there that this letter will be forwarded to you. I feel confident that your retirement will consist of pursuing some subjects of great interest to you and that you may relish the opportunity of doing those things that you best like to do instead of some of the tasks that had to be done. Apart from wishing you well, my purpose in writing is to ask you whether you might feel moved to write, on a topic of your choice, for the next volume of Advances in Agronomy. I have a particular reason in giving you this invitation now. As you know, I have edited this series for some time, but have now come to the conclusion that there would be merit in having a change to someone closer to the field and more knowledgeable than I about the productive younger people. Accordingly Volume 2 0 will be the last for which I shall be responsible. I am particularly anxious, therefore, that it be a volume of distinction. Nothing would please me more than to include a scholarly chapter by an old friend who has always maintained the highest standards in his professional work. You would have every freedom to determine your topic and the appropriate length. Manuscripts for Volume 20 have to be in my hands by November 1 next, which allows plenty of time for one whose life might be simplier now than it has been in recent years. I hope you will be able to see your way clear to accepting this invitation. With all good wishes. Yours sincerely
Experimental and numerical investigation of secondary screw perforation in the human proximal humerus
No full textSurgical treatment of proximal humerus fractures remains challenging, with a reported failure rate ranging from 15% to 35%. The dominant failure mode is secondary, i.e. post-operative screw perforation through the glenohumeral joint. A better understanding and the ability to predict this complication could lead to improved fracture fixation and decreased failure rate. The aims of this study were (1) to develop an experimental model for single screw perforation in the human humeral head and (2) to evaluate the ability of densitometric measures and micro finite element (microFE) analyses to predict the experimental failure event.
Screw perforation was investigated experimentally in twenty cuboidal specimens cut from four pairs of fresh-frozen human cadaveric proximal humeral heads. A centrally inserted 3.5 mm screw was pushed quasi-statically at a constant displacement rate until perforation of the articular cartilage in each specimen. Force and displacement were recorded and evaluated at both initial screw loosening and perforation events. Bone volume was calculated around and in front of the screw and tip-to-joint distance was measured on the combined pre- and post-instrumentation micro computed tomography (microCT) scans. Implicit linear and explicit non-linear microFE models were created based on the microCT scans. The strength of these densitometric, geometrical and microFE methods to predict the experimental results was evaluated via correlation analysis. The bone volume measures were optimized in a parametric analysis to maximize correlation coefficients.
The strongest and quantitatively correct predictions of perforation force (R2 = 0.93) and displacement (R2 = 0.77) were achieved using the explicit, non-linear microFE models. Linear microFE simulations provided the strongest predictions of loosening force (R2 = 0.90). Correlation strengths reached by optimized bone volume measures for predicting experimental force and by tip-to-joint distance for predicting displacement were only slightly inferior compared to the results of microFE models.
The strong correlations achieved with densitometric and geometric measures indicate that monotonic perforation of single screws through the articular surface of the humeral head can be well predicted with these easily accessible measures. However, non-linear microFE models delivered even stronger correlations and quantitatively correct predictions of perforation force and displacement. This indicates that if computational resources are available, non-linear simulations may have a high potential to investigate more complex fixations and loading scenarios
How does fair trade, as practised by Trade Aid and MINKA, contribute to the aspirations of Quechua producers in Peru?
Full text linkAs part of a Master of Indigenous Studies from the University of Otago, Trade Aid staff member, Michelia Ward, conducted research throughout 2011 and 2012 on whether fair trade is able to contribute to the aspirations of indigenous producers. The research focused on fair trade as practiced by Trade Aid, New Zealand and one of its Peruvian partners, MINKA.Fair trade is a development mechanism that aims to support food and craft producers around the world to improve their lives through trade. Many indigenous communities are producers of craft or food products such as woven textiles and coffee, and have engaged in fair trade relationships selling mainly to Western consumers. Fair trade organisations have universal principles that provide guarantees to consumers about working conditions, fair payment and trading relations with producer groups. This research project focuses on whether a universal framework designed to bring development to disadvantaged and marginalized producers can work for unique indigenous cultures across multiple continents. This research focuses on Trade Aid in New Zealand and their partnership with a Peruvian fair trade organisation, MINKA, who works with Quechua producers in the Andes. Indigenous theorists place large value on local epistemes (knowledge systems) and local solutions to local problems. Is fair trade one of these local solutions, or just another solution imposed from the outside upon indigenous producers
Accn_2338_Bx_2_Fd_5-accn 2338 bx 2 fd 5_Loose Pages Part 3
No full textA set of letter (mostly undated) to or from Lorenzo A. Richards: [1] Letter (undated) from Lorenzo A. Richards to The WIlliams and Wilkins Company of Baltimore, Maryland, sending a check for renewing a subscription for 1981; [2] Letter (undated) from Jim Thorup, Executive Secretary of the California Chapter, American Society of Agronomy, to members regarding an upcoming conference; [3] Letter dated 25 June (no year given) from Paul Richards to Lorenzo A. Richards with birthday wishes; [4] Letter (undated) from Bill Raney at Cary, Mississippi, to friends regarding recent retirement from the Agricultural Research Service; [5] Letter (undated) from Lorenzo A. Richards to Bill Brock, Chairman of the Republican National Committee; [6] Letter (undated) from Lorenzo A. Richards to Wall Street Week, requesting a transcript; [7] Note (undated) from Lorenzo A. Richards regarding forwarding mail; [8] Letter (undated) from Lorenzo A. Richards to Herback & Rademan Inc. of Philadelphia, Pennsylvania, returning an unsatisfactory hearing aid and asking for a refund; [9] Note (undated) from "Ken" to neighbors (including Lorenzo and Zilla Richards) offering services for yard care and beautification; [10] Letter (undated) from the World Affairs Council of Inland Southern California to Lorenzo A. Richards regarding renewal of his membership; [11] Letter (undated) from Joe Vale, circulation manager for Irrigation Age, to Lorenzo A. Richards regarding his change of address; [12] Draft Letter (undated) from Lorenzo and Zilla Richards to "Helen and Geoff" regarding their Christmas card; [13] Letter (undated) from Lorenzo A. Richards to Horace Mann, Attorney at Brigham City, Utah; [14] Letter (undated) from Jane Johnston Smith, Circulation promotion manager for Irrigation Age, to Lorenzo A. Richards; [15] Letter (undated) from K. O. Kessler of Kessler Sales Corporation to Lorenzo A. Richards with offer of booklet on marketing his inventions; [16] Draft Letter (undated) from Lorenzo A. Richards to "Clara" in Farmington, Utah, regarding a recent storm there; [17] Memo (undated) from Lorenzo A. Richards to Tom and Betty Schultz and Kenneth and Shirly Larson [18] Letter (undated) from Lorenzo A. Richards to Helen and Geoff [Bodman] thanking them for a portrait of Monterey BayCalifornia Chapter AMERICAN SOCIETY OF AGRONOMY Dear Member, The purpose of this letter is two-fold. First, we wish to inform you of our next conference far enough ahead so you can arrange your schedules to attend. The dates we have set are January 28 - 30, 1981. The conference will be held at the Sacramento Inn in Sacramento. This is the same location we were at last year. You will receive programs and registration information in December, following the National A.S.A. meetings in Detroit. The second purpose of this letter is to solicit your assistance in obtaining new members for our California Chapter. Enclosed you will find a brochure containing an application for membership. Please give this to a friend who should belong to our Chapter and encourage him to join. Looking forward to seeing you in Sacramento next January. Sincerely, JTTrhh Enclosure JIM THORUP Executive Secretary Dear Friends: My years of wDrk for ARS were wDnderful! The associates were marvelous and my "send off" at retirement was terrific. I had every intention of writing a letter to each of you - one of thanks. Those plans have not wDrked out. My priorities have changed. The care and management of flowers, vegetables and weeds has top priority. On the two acres - there are 36 rows of vegetables - each 70* long and between rains the grass has less chance of survival than such things as corn, beans, peas, okra, peanuts, tomatoes, squash, peppers, cucumbers, egg plants and gladiolas. First harvest was cucumbers. Flowers in beds around the yard were in\u27the most part grown fran seed in a new greenhouse (rainy day activity) - marigolds, zinnias, begonias, pansies, periwinkles and sunflowers. I also have 36 dahlias and 400 caladiums. Our front porch has pots of plants like ferns, begonias, gloxinias, cocks comb, vinca, zebrina, philadendron, etc. - plants that have graduated from the greenhouse. Left in the greenhouse are plants that survived the winter indoors and new ones such as ornamental peppers and batchelor buttons. Plants in our car enroute to Mississippi were badly damaged by cold. The ferns died. I rescued parts of philadendron and have about 60 rooted cuttings. The gardenia is doing fine. Jane Raney had to put a house full of furniture into a house full of furniture no easy task. We moved into the house with her Father. Our hDuse in Maryland remains unsold - interest rates got too high. We see children and grandchildren almost every week and I enjoy having a 3-year old and a 2-year old grandson help plant azalias and other" plants in areas where there\u27s partial shade. Only the garden has full sun. We\u27d like to have you ccme by for a visit. Our deep freeze is well stocked with catfish. If you all ccme at once, w= can catch seme* I\u27m an excellent fish cleaner. ,y>n oy^i Yours, THIS PRODUCT IS GUARANTEED BY H & R Refer any claim on this product to: HERBACH & RADEMANJNC 401 East Erie Avenue * Philadelphia, Penna. * 19134 PHONE: (215) 426-1700 Attention: Claims Dept Dear Neighbors: My name is Ken. I specialize in yard care and beautification. I can maintain your yard for a lot less money than you probably would have expected. I do basic yard maintenance, landscaping, some painting and most everything related to the yard. My rates are very reasonable and I am available on a regular basis or to help catch up on things for you. Please call between 6PM - #PM for estimates or an appointment. Ask for Ken. 684-2644* WORLD AFFAIRS COUNCIL OF PPAAD APUA AA AuAARNA A MEMBERSHIP REMINDER, ...AND PROGRAM UPDATE It has come to my attention that we have not received the renewal of your World Affairs Council membership for the current season. We have greatly appreciated your support in the past. You know the Council makes a unique contribution to the educational and cultural life of our conmunities. Annual dues are minimal, but your continued support is vital at this time for the Council\u27s operation. I hope you will respond to my letter by renewing your membership now. As you know, the Council is a nonpartisan, nonprofit educational organization and memberships are tax deductible. Programs are for Council members and their guests. Only members will receive invitations to future programs, and no tickets will be sold at the door. In the immediate future, members will be invited to meet with Senator William Proxmire (Jan.10); humorist Art Buchwald; CIA Director Stansfield Turner; Washington Post columnist David Broder; Ambassadors of the U.S. and foreign nations, and high-ranking officials debating SALT II. Gen. Alexander Haig and Senator S.I. Hayakawa each had several hundred Council members attending when they spoke to our forum this fall. Incidentally, few of us can attend all meetings. However, your membership dues make it possible for us to open our programs, free, to students from our area colleges and high schools Please send your renewal by Dec. 31, in order to remain on our invitation list. And do include your suggestions for future programs. Best Wishes Maryl__ri Jaceosen Executive Director Vice President Riverside, California 92521 • (714) 787-5744 The Council serves the Riverside-San Bernardino-Pomona region Dear IRRIGATION AGE Reader: Thank you for notifying us of your recent change of address. In order for us to process this change, you must complete and return the enclosed subscription card. (Please make sure to check the box that describes your operation.) As soon as we receive the completed card with your new address, we can begin sending you IRRIGATION AGE to your new address. Thanks for your interest in IRRIGATION AGE. -<Xoe Vale Circulation Manager Enclosure Irrigation Age A Webb Publication • 1999 Shepard Road-Saint Paul, Minnesota 55116-612 690-7203 Dear Irrigation Equipment Dealer: Have you ever been offered money to market your product? It Sounds like a girtmick, but when you hear my offer, you\u27ll see the legitimacy of it. As you\u27re well aware, many of the advertisers in Irrigation Age magazine are among the manufacturers you represent. Therefore, your products are exposed to thousands of irrigators all over the United States and Canada. Now I\u27d like tooffer FREE subscriptions to Irrigation Age to your customers. If you\u27ll send me the names and addresses of your irrigation equipment customers on the enclosed form, I\u27ll pay you 25C for every name you send WHO IS NOT NOW RECEIVING Irrigation Age. Your customers will have the opportunity to see your products advertised, while collecting a library of irrigation farming facts, through ten issues a year. Best of all, neither you nor your customer is under ANY obligation. (You have my assurance that all the names will be kept strictly confidential) . The deadline on my offer is March 7, 1986. Send your list today and I\u27ll send you a check promptly. (Please be sure to sign and date the form before returning your list). We appreciate your cooperation, and your customers will thank you, too. Sincerely, IRRIGATION AGE Jane Johnston Smith Circulation Promotion Manager JJS/ms encl. Reference: Chamber of Commerce, Fremont, Ohio; Society National Bank, Fremont, Ohio, or Your own Bank, Credit Bureau, or Chamber of Commerce 6SSL6R SALES CORPORATION KESSLER BUILDING • 124-T NAPOLEON STREET • FREMONT, OHIO 4-34-20 CABLE ADDRESS: KESCO • TELEPHONE: 332-64-96 AREA CODE 4-19 Dear Inventor: If you don\u27t send for your FREE copy of our booklet, "HCW TO OFFER YOUR INVENTION FOR SALE" we honestly believe you will be missing out on one of the finest invention bocklets yet published. The booklet is yours to keep, without any obligation whether or not you ever use our service. Here are just seme of the subjects you will find discussed in this booklet: "WHAT IS A SALEABLE INVENTION?" "HOW TO GO ABOUT SUBMITTING YOUR INVENTION TO PROSPECTIVE MANUFACTURERS" "APPROXIMATE ROYALTY RATES CURRENTLY BEING PAID" "IF YOUR INVENTION IS SOLD FOR CASH" "IF YOUR INVENTION IS SOLD FOR PART CASH, PART ROYALTY" "THE IMPORTANT POINTS IN LICENSING AGREEMENTS" All these subjects - and a lot more - are vitally important to you as an inventor. We offer it free because inventions are our business. There is no obligation on 37our part. None whatever. Just give us your name and address on the en osed card. No postage is necessary. But please do it now while the ooklets are available. Sincerely, y& YK. 0. Kessler KOK:cep P.S. If you have already written us, them you have your copy of the booklet by now. (If you have, then please disregard this letter, and if you have any questions about inventing that you would like answered, just write us.
Using and evaluating CASE tools : from software engineering to phenomenology
Full text linkCASE (Computer-Aided Systems Engineering) is a recent addition to the long line of
"silver bullets" that promise to transform information systems development, delivering
new levels of quality and productivity. CASE is particularly intriguing because
information systems (IS) practitioners spend their working lives applying information
technology (IT) to other people's work, and now they are applying it to themselves.
CASE research to date has been dominated by accounts of tool development,
normative writings (for example practitioner success stories) and surveys recording
IT specialists' perceptions. There have been very few in-depth studies of tool use,
and very few attempts to quantify benefits, therefore the essence of the CASE process
remains largely unexplored, and the views of stakeholders other than the IT specialists
have yet to be heard.
The research presented here addresses these concerns by adopting a hybrid research
approach combining action research, grounded theory and phenoinenology and using
both qualitative and quantitative data in order to tell the story of a system developer's
experience in using CASE tools in three information systems projects for a major UK
car manufacturer over a four year period. The author was the lead developer on all
three projects. Action research is a learning process, the researcher is an explorer.
At the start of this project it was assumed that the tools would be the focus of the
work. As the research progressed it became evident that the tools were but part of
a richer organisational context in which culture, politics, history, external initiatives
and cognitive limitations played important roles. The author continued to record
experiences and impressions of tool use in the project diary together with quality and
productivity metrics. But the diary also became home to a story of organisational
developments that had not originally been foreseen.
The principal contribution made by the work is to identity the narrow positivistic
nature of CASE knowledge, and to show via the research stories the overwhelming
importance of organisational context to systems development success and how the
exploration of context is poorly supported by the tools. Sixteen further contributions
are listed in the Conclusions to the thesis, including a major extension to Wynekoop
and Conger's CASE research taxonomy, an identification of the potentially
misleading nature of quantitative IS assessment and further evidence of the limitations
of the "scientific" approach to systems development.
The thesis is completed by two proposals for further work. The first seeks to
advance IS theory by developing further a number of emerging process models of IS
development. The second seeks to advance IS practice by asking the question "How
can CASE tools be used to stimulate awareness and debate about the effects of
organisational context?", and outlines a programme of research in this area
Enforcing reputation constraints on business process workflows
Full text linkThe problem of trust in determining the flow of execution of business processes has been in the centre of research interst in the last decade as business processes become a de facto model of Internet-based commerce, particularly with the increasing popularity in Cloud computing. One of the main mea-sures of trust is reputation, where the quality of services as provided to their clients can be used as the main factor in calculating service and service provider reputation values. The work presented here contributes to the solving of this problem by defining a model for the calculation of service reputa-tion levels in a BPEL-based business workflow. These levels of reputation are then used to control the execution of the workflow based on service-level agreement constraints provided by the users of the workflow. The main contribution of the paper is to first present a formal meaning for BPEL processes, which is constrained by reputation requirements from the users, and then we demonstrate that these requirements can be enforced using a reference architecture with a case scenario from the domain of distributed map processing. Finally, the paper discusses the possible threats that can be launched on such an architecture
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