La nécessité d'une multiplicité de concepts de gène en biologie

Le concept de gène est central en biologie. Certains ont avancé (Ruse (1971, 1976)) que la génétique classique pouvait être réduite à la génétique moléculaire. Dans le même ordre d'idée, Richard Dawkins, dans The Extended Phenotype, offre une double définition de son concept de gène qui présuppose qu'il soit possible d'opérer cette réduction. Nous comptons montrer que la génétique moléculaire et la génétique des populations ont chacune leurs problématiques propres en reconstituant l'histoire de la génétique depuis Darwin. Ensuite, nous expliciterons la position de Dawkins et soulignerons les contradictions auxquelles il parvient en raison de cette réduction infondée. À la suite de quoi, nous nous attarderons aux nouvelles découvertes moléculaires qui montrent qu'il n'est pas possible d'opérer la réduction d'un des concepts à l'autre. Nous terminerons en soulignant que la thèse génocentriste de Dawkins n'est pas mise en péril par l'abandon de la réduction, mais qu'il est nécessaire de tempérer ces prétentions. La conclusion globale de ce mémoire est qu'il est possible d'admettre le concept de Dawkins, mais pas la manière dont il l'utilise. Le concept est bon, il n'est tout simplement pas dans le bon cadre théorique.

Winds of doctrine : studies in contemporary opinion /

Title page in red and black.

Mamie's watchword /

Mode of access: Internet.

Poems and plays,

I. Preface. Essay on painting. Notes. Epistle to a friend, on the death of John Thornton, esq. Ode inscribed to John Howard, esq. Ode to Mr. Wright, of Derby. Ode to the Countess de Genlis. Sonnets, songs, and occasional verses.--II. An essay on history. Notes.--III. An essay on epic poetry. Notes.--IV. Notes to the third, fourth, and fifth epistles, of An essay on epic poetry.--V. The triumphs of temper. Plays of three acts, written for a private theatre: The happy prescription; or, The lady relieved from her lovers.--VI. Marcella; a tragedy. The two connoisseurs; a comedy. Lord Russell; a tragedy. The mausoleum; a comedy.

Winds of doctrine; studies in contemporary opinion,

The intellectual temper of the age.--Modernism and Christianity.--The philosophy of M. Henri Bergson.--The philosophy of Mr. Bertrand Russel.--Shelley: or, The poetic value of revolutionary principles.--The genteel tradition in American philosophy.

Damage by eutectic particle cracking in aluminum casting alloys A356/357

The strain dependence of particle cracking in aluminum alloys A356/357 in the T6 temper has been studied in a range of microstructures produced by varying solidification rate and Mg content, and by chemical (Sr) modification of the eutectic silicon. The damage accumulates linearly with the applied strain for all microstructures, but the rate depends on the secondary dendrite arm spacing and modification state. Large and elongated eutectic silicon particles in the unmodified alloys and large pi-phase (Al9FeMg3Si5) particles in alloy A357 show the greatest tendency to cracking. In alloy A356, cracking of eutectic silicon particles dominates the accumulation of damage while cracking of Fe-rich particles is relatively unimportant. However, in alloy A357, especially with Sr modification, cracking of the large pi-phase intermetallics accounts for the majority of damage at low and intermediate strains but becomes comparable with silicon particle cracking at large strains. Fracture occurs when the volume fraction of cracked particles (eutectic silicon and Fe-rich intermetallics combined) approximates 45 pct of the total particle volume fraction or when the number fraction of cracked particles is about 20 pct. The results are discussed in terms of Weibull statistics and existing models for dispersion hardening.

Type X pottery, Morobe Province, Papua New Guinea: Petrography and possible Micronesian relationships

Type X is one of four Post-Lapita pottery styles reported from Huon Peninsula and the Siassi Islands of Papua New Guinea. Previous petrographic work was inconclusive about its likely area of origin but indicated a possible Huon Peninsula source. Renewed analysis of a larger sample supports this conclusion and confirms the use of grog temper. This kind of temper is otherwise not recorded in the New Guinea region, and its use in the production of Type X was probably culturally driven. Comparisons between Type X and grog-tempered pottery from Palau, Yap, and Pohnpei in Micronesia lead to the suggestion that Type X probably derived from an otherwise unrecorded contact between Huon Peninsula and Palau about 1000 years ago. The article reviews other evidence for interaction between the New Guinea-Bismarck Archipelago region and various parts of Micronesia and concludes that the proposed Type X connection with Palau is but one of several prehistoric contacts between different parts of the regions. Recognition of such contacts, which could have been unintentional and on a small scale, may contribute to explaining the complex ethnolinguistic situation of Huon Peninsula.

The role of oxidation in the protection of sliding metal surfaces

This study is concerned with the mechanisms of growth and wear of protective oxide films formed under various tribological conditions. In the study three different tribological systems are examined in each of which oxidational wear is the dominant equilibrium mode. These are an unlubricated steel on steel system sliding at low and elevated temperatures, a boundary lubricated aluminium bronze on steel system and an unlubricated reciprocating sliding 9% Cr steel system operated at elevated temperature, in an atmosphere of carbon dioxide. The results of mechanical measurements of wear and friction are presented for a range of conditions of load, speed and temper.ature for the systems, together with the results of extensive examinations of the surfaces and sub­ surfaces by various physical methods of analysis. The major part of the thesis, however, is devoted to the development and application of surface models and theoretical quantative expressions in order to explain the observed oxidational wear phenomena. In this work, the mechanisms of formation of load bearing ox ide plateaux are described and are found to be dependent on system geometry and environment. The relative importance of ''in contact" and "out of contact" oxidation is identified together with growth rate constants appropriate to the two situations. Hypotheses are presented to explain the mechanisms of removal of plateaux to form wear debris. The latter hypotheses include the effects of cyclic stressing and dislocation accumulation, together with effects associated with the kinetics of growth and physical properties of the various oxides. The proposed surf ace mode1s have led to the develop­ ment of quantitative expressions for contact temperature, unlubricated wear rates, boundary lubricated wear rates and the wear of rna ter ial during the transition from severe to mild wear. In general theoretical predictions from these expressions are in very good agreement with experimental values.

Toughness variations during the tempering of a plain carbon, martensitic steel

The aim of this paper is to present results of toughness measurements and fractographic observations made on a quenched and tempered 0. 6%, carbon steel and to use these as a basis for a discussion of the factors affecting "623K (350 °C) embrittlement" (one-step temper embrittlement).

Gravel music

Gravel Music is a collection of poems, encompassing a wide range of styles from free verse to sonnets, including several unique forms, using rhyme where it was deemed pertinent, but also operating in a deconstructive mode where prosody is concerned. The book is divided into three sections. Poems in the first section strive toward political and critical utterance, addressing Marxism, Darwinism, neo-pragmatism, and humanism in a sequence of interrogations of the barriers between aesthetics, politics, critical theory, and philosophy, hoping to find traces of truth, fact, and authenticity that transcend category. The second section is comprised of a single lyrical narrative which follows a married couple as they interact on their small farm in late Autumn, addressing themes of literacy, love, and domesticity. The third section continues the focus on domestic life, but also addresses themes of nostalgia for childhood and lost love. The poems of this section move away from the formal, socio-political outbursts of the first section, instead operating primarily through persona and voice, bringing the book to a quiet, personal close.

Ocean acidification and the loss of phenolic substances in marine plants

Rising atmospheric CO2 often triggers the production of plant phenolics, including many that serve as herbivore deterrents, digestion reducers, antimicrobials, or ultraviolet sunscreens. Such responses are predicted by popular models of plant defense, especially resource availability models which link carbon availability to phenolic biosynthesis. CO2 availability is also increasing in the oceans, where anthropogenic emissions cause ocean acidification, decreasing seawater pH and shifting the carbonate system towards further CO2 enrichment. Such conditions tend to increase seagrass productivity but may also increase rates of grazing on these marine plants. Here we show that high CO2 / low pH conditions of OA decrease, rather than increase, concentrations of phenolic protective substances in seagrasses and eurysaline marine plants. We observed a loss of simple and polymeric phenolics in the seagrass Cymodocea nodosa near a volcanic CO2 vent on the Island of Vulcano, Italy, where pH values decreased from 8.1 to 7.3 and pCO2 concentrations increased ten-fold. We observed similar responses in two estuarine species, Ruppia maritima and Potamogeton perfoliatus, in in situ Free-Ocean-Carbon-Enrichment experiments conducted in tributaries of the Chesapeake Bay, USA. These responses are strikingly different than those exhibited by terrestrial plants. The loss of phenolic substances may explain the higher-than-usual rates of grazing observed near undersea CO2 vents and suggests that ocean acidification may alter coastal carbon fluxes by affecting rates of decomposition, grazing, and disease. Our observations temper recent predictions that seagrasses would necessarily be "winners" in a high CO2 world.

Evaluación de cuatro protocolos anestésicos fijos en diferentes técnicas quirúrgicas en Caninos

El presente estudio se llevó a cabo en la clínica veterinaria ubicada en la Facultad de Ciencia Animal de la Universidad Nacional Agraria . Se determinaron diferentes variables a evaluar para comparar la acción de 4 distintos protocolos anestésicos en caninos, utilizando propofol, ketamina, d iazepam, xilacina 2%, m idazolam, sulfato de atropina, maleato de acepromacina y ketoprofeno mediantes los cuales se evaluó el comportamiento de los 14 pacientes quirúr gicos determinándose los siguientes resultados: La frecuencia respiratoria promedio en los diferentes tiempo s fue: pre operatorio : 76 – 20 con una media de 48 , trans operatorio : 56 – 10 con una media de 33 y post operatorio : 36 – 8 con una media de 22 movi mientos por minuto. La frecuencia cardiaca promedio en los diferente tiempos fue: pre operatorio : 140 – 40 con una media de 90 , trans operatorio : 180 – 64 con una media de 122 y post operatorio 160 - 40 con una media de 100 pulsaciones por minuto. La temper atura rectal promedio en los di ferentes tiempo fue: pre operatorio : 40.4 - 37. 5 con una media de 38.9 , trans operatorio : 40 – 37 con una media de 38.5 y post operatorio : 39.2 - 37.2 con una media de °C. El porcentaje de hematocrito promedio en los diferentes tiempos fue: pre operatorio : 47 – 25 con una media de 37 , trans operatorio : 3 9 – 24 con una media de 31.5 y post operatorio : 39 – 24 con una media de 31.5 % . Donde al comparar la acción de estos protocolos en los diferentes tiempos, no conllevaron a ninguno de los pacientes intervenidos a situaciones críticas que condujeran a emergencias en el intraoperatorio, concluyendo que los protocolos empleados tienen amplio margen de seguridad y garantizaro n integralmente los cuatro puntos cardinales de la anestesia

Le couple conceptuel "public - privé" à l'intérieur de la littérature portant sur le problème des mains sales

Résumé: Le rapport entre la morale et la politique est un des plus vieux problèmes et des plus durables que s’est posé la philosophie morale, la philosophie politique, et plus récemment la philosophie du droit. Pour certains, la Morale, au sens large, doit guider les actions humaines dans toutes les sphères d’activité et les individus devraient ainsi, au mieux de leur capacité, chercher à se conformer à ses exigences. Dans ce cas, il ne peut y avoir de dilemme moral entre les exigences normatives issues de l’univers politique et les exigences, prétendument universelles, de la Morale. En contrepartie, d’autres suggèrent que l’on peut être justifié d’enfreindre, à certains moments, les exigences que l’on considère comme morales dans la vie « ordinaire » étant donné le caractère adversatif de la politique. Le dilemme se présente, ainsi, comme une tension entre deux normativités qui suggèrent une distinction entre ce qui relève du public et ce qui relève du privé. C’est en voulant répondre à ce dernier problème que s’est développé une littérature qui porte au cœur de sa conception le problème de la justification morale d’une action politique qui est moralement condamnable. Dans son ensemble, ce mémoire s’intéresse à analyser comment la littérature portant sur le problème des mains sales traite la question du couple conceptuel public – privé. Nous soutenons, qu’en retenant la possibilité d’une réelle distinction entre ces deux univers à normativités différentes, l’hypothèse qu’il y a effectivement une tension entre le domaine privé et le domaine public, qui ne peut totalement se soumettre aux exigences de la morale étant donné les particularités de l’action politique. Ceci étant dit, nous désirons nuancer une telle prise de position qui fait écho aux écrits de Machiavel. Ainsi, nous soutiendrons que cette distance entre le public et le privé est bien réelle, cependant, elle ne se présente pas aussi radicalement. Plutôt, elle se présente comme une distinction qui est liée à l’enjeu de l’évaluation, du jugement moral, faite par les individus qui sont hors de la politique et de ceux étant à l’intérieur de la politique.

Super-orbital variability of LS I+61 degrees 303 at TeV energies

Context. The gamma-ray binary LS I +61º303 is a well-established source from centimeter radio up to very high energy (VHE; E > 100 GeV). The broadband emission shows a periodicity of ∼26.5 days, coincident with the orbital period. A longer (super-orbital) period of 1667 ± 8 days was proposed from radio variability and confirmed using optical and high-energy (HE; E ¿ 100 MeV) gamma-ray observations. In this paper, we report on a four-year campaign performed by MAGIC together with archival data concentrating on a search for a long-timescale signature in the VHE emission from LS I +61º303. Aims. We focus on the search for super-orbital modulation of the VHE emission, similar to that observed at other energies, and on the search for correlations between TeV emission and an optical determination of the extension of the circumstellar disk. Methods. A four-year campaign has been carried out using the MAGIC telescopes. The source was observed during the orbital phases when the periodic VHE outbursts have occurred (φ = 0.55 – 0.75, one orbit = 26.496 days). Additionally, we included archival MAGIC observations and data published by the VERITAS collaboration in these studies. For the correlation studies, LS I +61◦303 has also been observed during the orbital phases where sporadic VHE emission had been detected in the past (φ = 0.75 – 1.0). These MAGIC observations were simultaneous with optical spectroscopy from the LIVERPOOL telescope. Results. The TeV flux of the periodical outburst in orbital phases φ = 0.5 – 0.75 was found to show yearly variability consistent with the long-term modulation of ∼4.5 years found in the radio band. This modulation of the TeV flux can be well described by a sine function with a best-fit period of 1610±58 days. The complete data, including archival observations, span two super-orbital periods. There is no evidence for a correlation between the TeV emission and the mass-loss rate of the Be star, but this may be affected by the strong, short-timescale (as short as intra-day) variation displayed by the Hα fluxes.

A Search for Muon Neutrinos in Coincidence with Gamma-Ray Bursts in the Southern Hemisphere Sky Using the IceCube Neutrino Observatory

The origin of observed ultra-high energy cosmic rays (UHECRs, energies in excess of $10^{18.5}$ eV) remains unknown, as extragalactic magnetic fields deflect these charged particles from their true origin. Interactions of these UHECRs at their source would invariably produce high energy neutrinos. As these neutrinos are chargeless and nearly massless, their propagation through the universe is unimpeded and their detection can be correlated with the origin of UHECRs. Gamma-ray bursts (GRBs) are one of the few possible origins for UHECRs, observed as short, immensely bright outbursts of gamma-rays at cosmological distances. The energy density of GRBs in the universe is capable of explaining the measured UHECR flux, making them promising UHECR sources. Interactions between UHECRs and the prompt gamma-ray emission of a GRB would produce neutrinos that would be detected in coincidence with the GRB’s gamma-ray emission. The IceCube Neutrino Observatory can be used to search for these neutrinos in coincidence with GRBs, detecting neutrinos through the Cherenkov radiation emitted by secondary charged particles produced in neutrino interactions in the South Pole glacial ice. Restricting these searches to be in coincidence with GRB gamma-ray emis- sion, analyses can be performed with very little atmospheric background. Previous searches have focused on detecting muon tracks from muon neutrino interactions fromthe Northern Hemisphere, where the Earth shields IceCube’s primary background of atmospheric muons, or spherical cascade events from neutrinos of all flavors from the entire sky, with no compelling neutrino signal found. Neutrino searches from GRBs with IceCube have been extended to a search for muon tracks in the Southern Hemisphere in coincidence with 664 GRBs over five years of IceCube data in this dissertation. Though this region of the sky contains IceCube’s primary background of atmospheric muons, it is also where IceCube is most sensitive to neutrinos at the very highest energies as Earth absorption in the Northern Hemisphere becomes relevant. As previous neutrino searches have strongly constrained neutrino production in GRBs, a new per-GRB analysis is introduced for the first time to discover neutrinos in coincidence with possibly rare neutrino-bright GRBs. A stacked analysis is also performed to discover a weak neutrino signal distributed over many GRBs. Results of this search are found to be consistent with atmospheric muon backgrounds. Combining this result with previously published searches for muon neutrino tracks in the Northern Hemisphere, cascade event searches over the entire sky, and an extension of the Northern Hemisphere track search in three additional years of IceCube data that is consistent with atmospheric backgrounds, the most stringent limits yet can be placed on prompt neutrino production in GRBs, which increasingly disfavor GRBs as primary sources of UHECRs in current GRB models.