Firm technological responses to regulatory changes: A longitudinal study in the Le Mans Prototype racing

Despite the critical role of regulations on competition and innovation, little is known about firm responses and related effects on performance under regulatory contingencies that are permissive or restrictive. By longitudinally investigating hybrid cars competing in the Le Mans Prototype racing (LMP1), we counter-intuitively suggest that permissive regulations increase technological uncertainty and thus decrease the firms’ likelihood of shifting their technological trajectory, while restrictive regulations lead to the opposite outcome. Further, we suggest that permissive regulations favour firms that innovate their products by sequentially upgrading core and peripheral subsystems, while restrictive regulations—in the long term— favour firms upgrading them simultaneously. Implications for theory and practice are discussed

Load Balancing a Cluster of Web Servers using Distributed Packet Rewriting

In this paper, we propose and evaluate an implementation of a prototype scalable web server. The prototype consists of a load-balanced cluster of hosts that collectively accept and service TCP connections. The host IP addresses are advertised using the Round Robin DNS technique, allowing any host to receive requests from any client. Once a client attempts to establish a TCP connection with one of the hosts, a decision is made as to whether or not the connection should be redirected to a different host---namely, the host with the lowest number of established connections. We use the low-overhead Distributed Packet Rewriting (DPR) technique to redirect TCP connections. In our prototype, each host keeps information about connections in hash tables and linked lists. Every time a packet arrives, it is examined to see if it has to be redirected or not. Load information is maintained using periodic broadcasts amongst the cluster hosts.National Science Foundation (CCR-9706685); Microsof

Large Transverse Momentum Jet Production and DIS Distributions of the Proton

We have calculated the single jet inclusive cross section as measured at Fermilab in next-to-leading order QCD using recent parton distributions of the CTEQ collaboration. We studied the scheme dependence of the jet cross section by employing the \overline{\mbox{MS}} and DIS factorization schemes consistently. For $E_T > 200$ GeV, we find that the cross section in the DIS scheme is larger than in the \overline{\mbox{MS}} scheme yielding a satisfactory description of the CDF data over the whole $E_T$ range in the DIS scheme.Comment: 7 pages, latex, 2 figures include

A história da educacâo matemática como linha de pesquisa em um mestrado profissional em educacâo matemática

A Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) criou no Brasil, desde 2002, uma segunda modalidade de pós-graduação em nível de mestrado: aos mestrados acadêmicos juntaram-se os mestrados profissionais. As pesquisas nesse nível de formação na linha de História da Educação Matemática têm sido normalmente desenvolvidas por programas acadêmicos. Como contribuição ao debate, trago as experiências vividas pelo Laboratório de Pesquisa em História da Educação Matemática (LaPHEM), em especial sobre as adequações que vem desenvolvendo em produções de um mestrado profissional nessa linha de pesquisa

Measurement of the neutral pion cross section in proton-proton collisions at sqrt{s}=200GeV with PHENIX

The inclusive cross section for neutral pion production in the range 1<p_T<13GeV/c in |eta|<0.35 has been measured by the PHENIX experiment in proton-proton collisions at sqrt{s}=200GeV. An NLO pQCD calculation is, within the experimental and theoretical uncertainties, consistent with the measurement.Comment: 4 pages, 4 figures. Talk presented at Quark Matter 2002, Nantes, France, July 18-24, 2002. To appear in the proceedings (Nucl. Phys. A

Heavy-quark jets in hadronic collisions

We present a next-to-leading order QCD calculation of the production rates of jets containing heavy quarks. This calculation is performed using the standard Snowmass jet algorithm; it therefore allows a comparison with similar results known at next-to-leading order for generic jets. As an application, we present results for the inclusive transverse energy of charm and bottom jets at the Tevatron collider, with a complete study of the dependence on the jet cone-size and of the theoretical uncertainties.Comment: 23 pages Latex, uses epsfig.sty, 16 eps figures appended as uuencoded, gzipped, tarred fil

VLA and ATCA Search for Natal Star Clusters in Nearby Star-Forming Galaxies

In order to investigate the relationship between the local environment and the properties of natal star clusters, we obtained radio observations of 25 star-forming galaxies within 20 Mpc using the Very Large Array (VLA) and the Australia Telescope Compact Array (ATCA). Natal star-forming regions can be identified by their characteristic thermal radio emission, which is manifest in their spectral index at centimeter wavelengths. The host galaxies in our sample were selected based upon their likelihood of harboring young star formation. In star-forming regions, the ionizing flux of massive embedded stars powers the dominant thermal free-free emission of those sources, resulting in a spectral index of {\alpha} {\gtrsim} -0.2 (where S{\nu} {\propto} {\nu}{\alpha}), which we compute. With the current sensitivity, we find that of the 25 galaxies in this sample only five have radio sources with spectral indices that are only consistent with a thermal origin; four have radio sources that are only consistent with a non-thermal origin; six have radio sources whose nature is ambiguous due to uncertainties in the spectral index; and sixteen have no detected radio sources. For those sources that appear to be dominated by thermal emission, we infer the ionizing flux of the star clusters and the number of equivalent O7.5 V stars that are required to produce the observed radio flux densities. The most radio-luminous clusters that we detect have an equivalent of ~7x103 O7.5 V stars, and the smallest only have an equivalent of ~102 O7.5 V stars; thus these star-forming regions span the range of large OB-associations to moderate "super star clusters" (SSCs). With the current detection limits, we also place upper limits on the masses of clusters that could have recently formed...Comment: Subject headings: galaxies: star clusters--galaxies: irregular--galaxies: starburst--stars: formation--HII regions 34 pages, 11 figures, accepted for publication in The Astronomical Journal (1 February 2011

Endocrinologic Control of Men's Sexual Desire and Arousal/Erection

Several hormones and neurotransmitters orchestrate men's sexual response, including the appetitive (sexual desire) and consummative (arousal and penile erection) phases. AIM: To provide an overview and recommendations regarding endocrinologic control of sexual desire and arousal and erection and their disturbances. METHODS: Medical literature was reviewed by the subcommittee of the International Consultation of Sexual Medicine, followed by extensive internal discussion, and then public presentation and discussion with other experts. The role of pituitary (prolactin, oxytocin, growth hormone, and α-melanocyte-stimulating hormone), thyroid, and testicular hormones was scrutinized and discussed. MAIN OUTCOME MEASURES: Recommendations were based on grading of evidence-based medical literature, followed by interactive discussion. RESULTS: Testosterone has a primary role in controlling and synchronizing male sexual desire and arousal, acting at multiple levels. Accordingly, meta-analysis indicates that testosterone therapy for hypogonadal individuals can improve low desire and erectile dysfunction. Hyperprolactinemia is associated with low desire that can be successfully corrected by appropriate treatments. Oxytocin and α-melanocyte-stimulating hormone are important in eliciting sexual arousal; however, use of these peptides, or their analogs, for stimulating sexual arousal is still under investigation. Evaluation and treatment of other endocrine disorders are suggested only in selected cases. CONCLUSION: Endocrine abnormalities are common in patients with sexual dysfunction. Their identification and treatment is strongly encouraged in disturbances of sexual desire and arousal

Buenos Aires, algo más que contenedores: la presencia de la arquitectura en la infraestructura portuaria

Los puertos son –y han sido- sitios de encuentro de personas, mercancías y actividades diversas a lo largo del tiempo, aunque las necesidades de usos y apropiación territorial de sus emplazamientos muten permanentemente. En la reestructuración portuaria muchas de sus instalaciones han sido desmanteladas, otras conservadas y reconvertidas, y otras subsisten “inútiles” frente a la gran metrópolis que las ignora. Los almacenes, depósitos, silos y muelles expresan la tecnología industrial de fines de siglo XIX; hormigón, hierro, madera y piedra conforman un patrimonio construido, y sus edificios conforman un paisaje que combina grandes volúmenes, líneas simples y detalles que definen un estilo de color homogéneo y memoria colectiva de un tiempo que trasciende a través de ellos. El puerto de Buenos Aires es intrínsicamente un paisaje en si mismo; las instalaciones preexistentes hablan de relaciones socioculturales e inducen el poder nacional de la época en que fueron concebidas, promoviendo el dialogo entre memoria colectiva y actualidad, definiendo el skyline urbano de la ciudad de Buenos Aires frente al río. La intención de este trabajo es identificar el patrimonio edilicio –arquitectónico e ingenieril- presente en el territorio portuario de la ciudad de Buenos Aires, y destacar su importancia en las relaciones urbanas, algo olvidadas y escondidas detrás de contenedores, camiones y grúas.Port are and have been places where people meet, exchange goods and develop diverse activities along the time, although the needs of uses and territorial appropriation of their emplacements change permanently. In port restructuring (*) many of its facilities have been dismantled, others retained and converted, and others remain “useless” facing the great metropolis that ignore them. Stores, warehouses, silos and piers express the industrial technology of late nineteenth century; concrete, iron, wood and stone constitute a built heritage, and its buildings form a landscape that combines large volumes, simple lines and details that define a style of homogeneous color and collective memory from a time that transcends through them. The Port of Buenos Aires is intrinsically a landscape in itself; the existing facilities speak of sociocultural relations and remind the national power at the time they were conceived, promoting dialogue between collective memory and actuality, defining the urban skyline of Buenos Aires city facing the river.The aim of this paper is to identify the architectural and engineering heritage present in the port territory of Buenos Aires city, and highlight its importance in urban relationships, something forgotten and hidden behind containers, trucks and cranes

La escala del paisaje portuario en tiempos de contenedores: el Puerto de Buenos Aires: imágenes en transición

La identidad de los ambientes portuarios, esta en el imaginario colectivo asociado a diversos acontecimientos, por un lado a un lugar de trabajo arduo –como lo retrato Quinquela-, por otro fue lugar de ingreso de nuestros antepasados –la inmigración europea a principios del siglo XX-. Hay muchas imágenes coligadas al paisaje del puerto y su entorno, pero en esta presentación, nos centraremos en el cambio de actividades del puerto de Buenos Aires de principios del siglo XX a principios del siglo XXI, y su repercusión en el paisaje a partir de la incorporación del contenedor. Los contextos portuarios son sitios en transición, dinámicos, que expresan la magnitud del paso del tiempo a través del ordenamiento del espacio físico, esto deriva en un cambio del paradigma en cuanto al paisaje que devuelve a la ciudad, ya que no es incorporado en la identidad del porteño. El apilamiento de contenedores en el escenario de algunos puertos –en este caso Buenos Aires- reconstruye paisajes que dialogan –o no- con el ciudadano y el afuera, asimilables -o no- en la dialéctica “puerto-ciudad”, estos espacios están ahí, confieren imágenes del tiempo y el espacio al que corresponden. Se crean así nuevas identidades referentes al paisaje, hoy día el puerto de contenedores ofrece una perspectiva colorida y geométrica de cajas acumuladas, y de grúas y camiones que se agitan dentro del espacio portuario, hasta ahora la hipótesis que sostenemos es que ese “paisaje otro” es ajeno a la ciudad. Este es el desafío que nos proponemos, reflexionar acerca de la dinámica paisajista del puerto de Buenos Aires y por qué no es incorporado como una imagen de arquitectura paisajística