2,413 research outputs found
Theories of Technological Progress and the British Textile Industry from Kay to Cartwright
Editada en la Fundación Empresa PúblicaLa industria textil británica continúa en el centro del debate sobre la revolución industrial. Las innovaciones técnicas en el período produjeron una aceleración extraordinaria del crecimiento del output y una considerable reducción de los precios de los tejidos. En este trabajo presentamos un estudio de la comunidad de los inventores responsables de la transformación tecnológica, lo que nos permite alcanzar una serie de conclusiones nuevas sobre el ritmo y dirección de la actividad innovadora durante la revolución industrialThe cotton textile industry remains central to all accounts of the first industrial revolution. Innovations in this period precipitated an extraordinary acceleration in the growth of output and a steep decline in the cost of producing all varieties of cloth. In this paper we outline an explanation through an analysis of the community of inventors responsible for the technological transformation, which enables us to offer some generalizations of the pace and pattern of the inventive activity in this period.Publicad
From The Med to The World
Seagoing Ships and Seamanship in the Bronze Age Levant, by Shelley Wachsmann; Homeric Seafaring, by Samuel Mark; Byzantine Warship vs Arab Warship, 7th–11th Centuries, by Angus Konsta
The Relationship Between Cadets who prefer Gangsta or Hip Hop Attire and Their Academic Performance
The following goals were used to direct this research: 1. Determine level of importance of academic excellence within this population; 2. Determine the importance of peer influence with regard to academic success within this population; 3. Determine post secondary school aspirations of members of this population; 4. Determine academic success of members of this populatio
The influence of locally applied platelet-derived growth factor-BB on free tendon graft remodeling after anterior cruciate ligament reconstruction
Titelblatt, Inhaltsverzeichnis, Anhänge, Danksagungen, Lebenslauf,
Eigenständigkeitserklärung
Einleitung und Zielstellung
Literaturteil
Material und Methoden
Ergebnisse
Diskussion
Zusammenfassung
Summary
LiteraturBeim Menschen ist die Verletzung des vorderen Kreuzbandes (VKB) das häufigste
Trauma des Kniegelenkes. Sie wird mangels Spontanheilung zunehmend durch eine
Rekonstruktion mit Hilfe autologer Sehnentransplantate versorgt. Entgegen dem
bekannten positiven Einfluss von platelet-derived growth factor (PDGF) bei der
Wundheilung, wurde dies bei der Heilung eines freien Sehnentransplantates
bisher nicht nachgewiesen. Ziel der Arbeit war es, elektronenmikroskopisch den
Einfluss von PDGF-BB auf die strukturelle Transformation und Wiederherstellung
eines freien Sehnentransplantates nach einer Rekonstruktion des VKB in vivo zu
untersuchen. Dazu wurde bei 48 ausgewachsenen Schafen das VKB durch ein
Transplantat aus der Endsehne des M. flexor digitalis superficialis ersetzt.
Die Tiere wurden in acht Gruppen eingeteilt, von denen vier als
Kontrollgruppen und vier als Versuchsgruppen dienten, in deren Transplantate
lokal 60 µg PDGF-BB appliziert wurde. Je zwei Gruppen wurden 3, 6, 12 und 24
Wochen post op. eingeschläfert. Anschliessend wurden
transmissionselektronenmikroskopische Untersuchungen von
Transplantatquerschnitten vorgenommen. Nach standardisierter
Materialaufarbeitung wurden von jeder Probe sechs Fotografien angefertigt, die
digital auf 80.000 vergrössert und danach ebenfalls digital ausgewertet
wurden. Als Messparameter dienten die Anzahl kollagener Fibrillen/µm2, der
Fibrillendurchmesser, die Fibrillenfläche/µm2 und die Verteilung der
verschiedenen Fibrillendurchmesser. Bänder und Sehnen unterscheiden sich
strukturell und mechanisch voneinander. Ultrastrukturell unterschieden sich
die beiden Gewebe signifikant nur in der Fibrillenfläche bei ansonsten
ähnlichen Messparametern. Deshalb wird die Flexorsehne auch aus
transmissionselektronen-mikroskopischer Sicht als geeignetes VKB-Ersatzgewebe
erachtet. Die in der Studie als VKB-Ersatz eingesetzte Flexorsehne zeigte
biomechanisch eine deutlich höhere Versagenskraft als das native VKB.
Ultrastrukturell erfolgte die Transformation der Flexorsehne nach ihrer
Transplantation in VKB-Position überwiegend in den ersten 12 Wochen post op.
Innerhalb der ersten sechs Wochen post op. war sie durch einen weitgehenden
Strukturverlust des Transplantates, Verringerung der Fibrillenanzahl, Zunahme
des Fibrillendurchmessers und der Fibrillenfläche gekennzeichnet. Die
Verteilung der Fibrillendurchmesser hatte sich in Richtung der Fibrillen mit
einem Durchmesser > 140 nm verschoben. Anschliessend folgte eine
Restrukturierungsphase, die sich durch eine signifikante Steigerung der
Fibrillenanzahl, Verringerung des Fibrillendurchmessers und der
Fibrillenfläche bei absoluter Dominanz der dünnen Fibrillen mit einem
Durchmesser von 20-60 nm auszeichnete. Was die Wirkung des applizierten PDGF
angeht, so waren die strukturellen Veränderungen bei den Kontroll- und
Versuchsgruppen grundsätzlich ähnlich, wobei die Transplantate 24 Wochen post
op. die morphologischen Eigenschaften des intakten VKB noch nicht erlangt
hatten. Der wesentliche Unterschied lag in der um drei Wochen früheren
Restrukturierung und einer nach 12 Wochen signifikant höheren Fibrillenanzahl
der Transplantate aus den PDGF-behandelten Versuchsgruppen. Die Unterschiede
zwischen den PDGF-behandelten und den Kontrolltransplantaten, lassen auf eine
förderliche Wirkung von PDGF schliessen. Flankierende Untersuchungen der
Arbeitsgruppe hinsichtlich biomechanischem Verhalten und histologischen
Veränderungen des Transplantates im Zeitverlauf bestätigten die eigenen
ultrastrukturellen Beobachtungen in den Grundaussagen. Um die Wirksamkeit von
PDGF, seine Konzentration und Kinetik sowie die Wirkung von PDGF alleine oder
in Kombination mit anderen Wachstumsfaktoren bei der Transplantatheilung in
vivo noch genauer zu verfolgen, müssen noch weitere Studien durchgeführt
werden. Insgesamt zeigte sich jedoch, dass die lokale Applikation von PDGF
sich positiv, wenn auch nicht stark ausgeprägt auf die Transplantatheilung
auswirkte und der Einsatz dieses Wachstumsfaktors Möglichkeiten eröffnet,
speziell in der frühen postoperativen Phase, die strukturellen und
mechanischen Eigenschaften eines Kreuzbandersatzes zu verbessern.Injury to the anterior cruciate ligament (ACL) is the most frequent trauma of
the knee joint in humans. Due to its inability to heal spontaneously, surgical
treatment of ACL injuries is constantly increasing. Although the positive
influence of platelet-derived growth factor (PDGF) on wound healing has been
proved, up to date there is no data of its influence on the healing of a free
tendon graft. The objective of the study was to electron microscopically
evaluate the effect of PDGF-BB on the structural transformation and recovery
of a free tendon graft after ACL reconstruction in vivo. In 48 sheep with
skeletally mature hindlegs, the ACL was reconstructed using the superficial
digital flexor tendon. The animals were divided into eight groups four of
which served as control groups and four served as study groups. The grafts of
the study groups received a local dose of 60 µg of PDGF-BB. Two groups each
were sacrificed 3, 6, 12 and 24 weeks postoperatively. Subsequently, electron
microscopical evaluation of cross sections of midsubstance graft tissue
samples was performed. Following standardized sample processing, six
photomicrographs of randomly selected areas were taken and digitally analyzed
at a magnification of 80,000. The following parameters were determined: total
number of collagen fibrils/µm2, fibril diameter, fibril area/µm2 and
distribution of the different fibril diameters within the graft. Ligaments and
grafts are structurally and mechanically different. With regard to
ultrastructure, only the fibril area/µm2 of the two tissues was significantly
different, whereas all other parameters were similar. The flexor tendon used
in this study presented a significantly higher failure load compared to the
intact ACL. Based on these findings, also from an electron microscopical point
of view, the digital flexor tendon is considered to be a suitable graft for
ACL reconstruction. Ultrastructurally, after reconstruction of the ACL,
transformation of the flexor tendon graft took place primarily in the first 12
weeks postoperatively. Within the first six weeks, it was characterized by a
large structural loss, decrease in number of fibrils, increase in fibril
diameter and fibril area. Distribution of the different fibril diameters had
shifted towards fibrils > 140 nm. This phase of degeneration was followed by a
phase of regeneration, characterized by a significant increase in numbers of
collagen fibrils, decrease in fibril diameter and fibril area, and absolute
dominance of thin fibrils with a diameter of 20-60 nm. In terms of PDGF
application, the structural alterations of the graft after ACL reconstruction
was similar in both groups, however, the graft had not reached the
morphological features of a the native ACL. The most striking difference
between the control and study groups was the fact that the latter one
underwent reconstruction three weeks earlier and presented a significantly
higher number of collagen fibrils 12 weeks post surgically compared to the
control groups. The differences between the study and control groups suggested
a positive, albeit not very pronounced influence of PDGF on graft healing.
Accompanying evaluations of the research group in terms of biomechanical and
histological changes of the graft post surgically, confirmed the fundamental
assertions of the own ultrastructural results. In order to more accurately
assess the potency of PDGF, its concentration and kinetics as well as its
effectiveness alone or in combination with other growth factors on graft
healing in vivo, further studies will have to be done. In conclusion it can be
stated, however, that the local application of PDGF had a positive influence
on graft healing and especially in the early postoperative healing phase, this
growth factor provides opportunities, to enhance the structural and mechanical
characteristics of a reconstructed ACL
Tortious Tweets: A Practical Guide to Applying Traditional Defamation Law to Twibel Claims
The article discusses certain actions and defenses related to Twitter, an online social networking service, and its features which can help in defamation analysis. It explores the ways in which Twitter can be used and discusses measures to resolve claims related to Twibel, a concept which has been introduced to fight people who abuse the power of Twitter. It reflects on the revision of current defamation framework and discusses application of traditional considerations to Twibel claims
Taxes and Ability to Pay in Municipal Bankruptcy
Scholars and commentators have argued that municipalities can and should use bankruptcy to shed unwanted liabilities, particularly employee healthcare and pension commitments. Courts increasingly have agreed: Detroit’s approved bankruptcy plan cut pensions, and the bankruptcy court overseeing the bankruptcy of Stockton, California brought down barriers to pension-cutting. Both courts found their way around state provisions arguably protecting municipal pensions. Now that pension-cutting in bankruptcy has momentum, we can expect to hear arguments for using bankruptcy not just in cases like Detroit and Stockton where the municipality cannot meet all its obligations, but also in cases where residents or politicians come to regret municipal promises to workers. This Article presents the most sustained, straightforward, and comprehensive argument to date that existing law requires bankruptcy courts to provide relief only when municipalities are reasonably unable to meet their obligations. The legislative history of the municipal bankruptcy statutes consistently sounds this theme, and judicial precedents are in agreement. Congress did not provide a clear standard for courts to apply when looking at tax levels in municipal bankruptcy. Although the legislative history and case law provide some support for the proposition that municipalities should be required to tax at the level that maximizes revenue, the Article suggests a more moderate criterion: absent a compelling explanation, courts could require that a municipality tax at the top of its peer group as a condition of bankruptcy eligibility and plan confirmation
Constitutionalized Consent: Preemption of State Tax Limits in Municipal Bankruptcy
Many states impose absolute limits on municipal taxes, such as a one percent maximum property tax. States also commonly require electoral approval of municipal taxes. California\u27s Proposition 13 is the best-known example of such state-imposed requirements. Such restrictions reduce municipal flexibility in dealing with financial distress and may contribute to municipal financial distress
Interview with Patrick Hunt by Mike Hastings
Biographical NotePatrick E. Hunt was born on August 19, 1946, in Bangor, Maine, and grew up in Island Falls with his parents, Theodore E. Hunt and Margaret I. Doherty, and his three sisters. Theodore attended Husson College, and operated a restaurant in Island Falls until the 1960s, when he became the village postmaster; Margaret was from Boston, a graduate of Charlestown High School, and of Irish descent from Clonmany County, Donegal. Patrick attended Ricker College, entered the Army in 1968, and served in Korea; he completed his degree in economics at Ricker in 1971. Subsequently, he joined the Drug Enforcement Administration of the United States Department of Justice in Massachusetts, attending evening law school courses, before returning to Island Falls in 1983 to start his own law practice. He was still practicing there at the time of this interview.
SummaryInterview includes discussion of: family and educational background; Island Falls, Maine, community; Ed Muskie’s ideas for economic improvements; Drug Enforcement Administration; George Mitchell as U.S. attorney; politic aspects of U.S. Attorney’s Office; family background and Joe Doherty’s Northern Ireland story; George Mitchell’s work in Northern Ireland; thoughts on George Mitchell as president; and politics and economics in Aroostook County
Credit Ratings in Insurance Regulation: The Missing Piece of Financial Reform
The Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010 directed federal financial regulators to remove credit ratings from their rules, but had nothing to say about the use of credit ratings by state insurance regulators. This omission is significant because insurers own nearly twice as many foreign, corporate, and municipal bonds as banks do. During the 2000s, state insurance regulators came to rely increasingly on rating agencies rather than the regulators’ in-house valuation office to assess the credit risks of these holdings. After the perceived widespread failure of ratings in the crisis, the insurance regulators did undertake a review of their use of ratings in regulation. This review, which has been going on for over two years, does not seem to be on a path to eliminate the use of credit ratings in insurance regulation. The one decisive action regulators have taken in this area, ceasing reliance on credit ratings on mortgage-backed securities in favor of a standard more favorable to the industry, seems to be an example of what I call a rule bailout —an ad hoc regulatory rule change to benefit a struggling industry during a crisis. The increasing dependence on outsourced credit ratings under industry pressure during a boom, rule bailout during a crisis, and subsequent reconsideration of the use of credit ratings suggests a political cycle of financial regulation, in which significant reform is feasible only in the aftermath of crisis. This cycle complicates several leading technical proposals for improving capital regulation and may limit what we can expect from the project of financial regulation generally
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