Understanding higher structures through Quillen-Segal objects

If $\mathscr{M}$ is a model category and $\mathcal{U}: \mathscr{A} \rightarrow \mathscr{M}$ is a functor, we defined a Quillen-Segal $\mathcal{U}$-object as a weak equivalence $\mathscr{F}: s(\mathscr{F}) \xrightarrow{\sim} t(\mathscr{F})$ such that $t(\mathscr{F})=\mathcal{U}(b)$ for some $b\in \mathscr{A}$. If $\mathcal{U}$ is the nerve functor $\mathcal{U}: \mathbf{Cat} \rightarrow \mathbf{sSet}_J$, with the Joyal model structure on $\mathbf{sSet}$, then studying the comma category $(\mathbf{sSet}_J \downarrow \mathcal{U})$ leads naturally to concepts, such as Lurie's $\infty$-operad. It also gives simple examples of presentable, stable $\infty$-category, and higher topos. If we consider the \textit{coherent nerve} $\mathcal{U}: \mathbf{sCat}_B \rightarrow \mathbf{sSet}_J$, then the theory of QS-objects directly connects with the program of Riehl and Verity. If we apply our main result when $\mathcal{U}$ is the identity $Id: \mathbf{sSet}_Q \rightarrow \mathbf{sSet}_Q$, with the Quillen model structure, the homotopy theory of QS-objects is equivalent to that of Kan complexes and we believe that this is an \textit{avatar} of Voevodsky's \textit{Univalence axiom}. This equivalence holds for any combinatorial and left proper $\mathscr{M}$. This result agrees with our intuition, since by essence the `\textit{Quillen-Segal type}' is the \textit{Equivalence type}Comment: 9 pages, First draft. Comment are always welcom

Amiens – 36 rue Cordier

Suite au projet de réalisation d’un immeuble d’habitation situé le long de la rue Cordier au numéro 36, une opération de diagnostic archéologique a été réalisée. Deux tranchées perpendiculaires respectivement de 4,60 m et 7,50 m de long sur 2 m de large n’ont permis de déceler aucune structure manifestant une occupation humaine du secteur antérieure au xxe s. Seules diverses couches de remblais et/ou de niveaux de destruction ont été observé jusqu’à une profondeur maximum de 60 m au-delà de l..

Amiens – 32-32bis-34 rue Cordier

Suite au projet de réalisation d’un immeuble d’habitation situé le long de la rue Cordier aux nos 32-32b et 34, une opération de diagnostic archéologique a été réalisée. Trois tranchées d’environ 14 m de long sur 2 m de large n’ont permis de déceler aucune structure manifestant une occupation humaine du secteur antérieure au xxe s. Seules diverses couches de remblais et/ou de niveaux de destruction ont été observé jusqu’à une profondeur maximum de 1,60 m au-delà de laquelle le niveau naturel ..

Tibetan -las, -nas, and -bas

In descriptions of Tibetan grammar it is common to treat -las and -nas together in the discussion of case marking, signalling merely that -las is capable of forming comparisons whereas -nas is not. Similarly, in the discussion of comparison most authors make no distinction between the suffixes -bas and -las. A look at a few examples of these three morphemes demonstrates that they have quite distinct syntax and semantics

TECTONIC CONTROLS ON FLUVIAL LANDSCAPE DEVELOPMENT IN CENTRAL-EASTERN PORTUGAL: INSIGHTS FROM LONG PROFILE TRIBUTARY STREAM ANALYSES

This study examines the long profiles of tributaries of the Tejo (Tagus) and Zêzere rivers in central eastern Portugal (West Iberia) in order to provide new insights into the patterns, timing and controls on drainage development during the Pleistocene to Holocene incision stage. The long profiles were extracted from lower order tributary streams associated with the trunk drainage of the Tejo River and one main tributary, the Zêzere River (Fig. 1). These streams flow through a landscape strongly influenced by variations in bedrock lithology (mainly granites and metasediments), fault structures delimiting crustal blocks with distinct uplift rates, and a base-level lowering history (tectonic uplift / eustatic). The long profiles of the tributaries of the Tejo and Zêzere rivers record a series of transient and permanent knickpoints. The permanent knickpoints have direct correlation with the bedrock strength, corresponding to the outcropping of very hard quartzites or to the transition from softer (slates/metagreywaques) to harder (granite) basement. The analyzed streams/rivers record also an older transient knickpoint/knickzone separating: a) an upstream relict graded profile, with lower steepness and higher concavity, that reflects a long period of quasi-equilibrium conditions reached after the beginning of the incision stage; and b) a downstream reach displaying a rejuvenated long profile, with steeper gradient and lower concavity, particularly for the final segment, which is often convex (Fig. 2). The rejuvenated reaches testify the upstream propagation of several incision waves that are the response of each stream to continuous or increasing crustal uplift and dominant periods of base-level lowering by the trunk drainages, coeval of low sea level conditions. The long profiles and their morphological configurations enabled spatial and relative temporal patterns of incision to be quantified for each individual tributary stream. The incision values of streams flowing in uplifted blocks of the Portuguese Central Range (PCR) (ca.380-280 m) indicate differential uplift and are higher than the incision values of streams flowing on the adjacent South Portugal planation surface – the Meseta (ca. 200 m). The normalized steepness index, calculated using the method of Wobus et al. (2006), proved to be sensitive to active tectonics, as lower ksn values were found in relict graded profiles of streams located in less uplifted blocks, (e.g. Sertã stream in the PCR), or in those flowing through tectonic depressions. Fig. 1 – Geological map of the study area. 1 – fluvial terraces (Pleistocene); 2 – sedimentary cover (Paleogene and Neogene); 3 – slates and metasandstones (Devonian); 4 – slates and quartzites (Silurian); 5 – quartzites (Ordovician); 6 – slates and metagreywackes (Precambrian to Cambrian); 7 – slates, metagreywackes and limestones (Precambrian); 8 – granites and ortogneisses; 9 – diorites and gabros; 10 - fault. SFf – Sobreira Formosa fault; Sf – Sertã fault; Pf – Ponsul fault; Gf – Grade fault. The differential uplift indicated by the distribution of the ksn values and by the fluvial incision was likely accumulated on a few major faults, as the Sobreira Formosa fault (SFf), thus corroborating the tectonic activity of these faults. Due to the fact that the relict graded profiles can be correlated with other geomorphic references documented in the study area, namely the T1 terrace of the Tagus River (with an age of ca. 1 Myr), the following incision rates can be estimated: a) for the studied streams located in uplifted blocks of the PCR, 0.38 m/kyr to 0.28 m/kyr; b) for the streams flowing on the South Portugal planation surface, 0.20 m/kyr. The differential uplift inferred between crustal blocks in the study area corroborates the neotectonic activity of the bordering faults, which has been proposed in previous studies based upon less robust data. Fig. 2 – Longitudinal profile of the Nisa stream a tributary of the Tejo River. Note the equilibrium relict profile upstream the older transient knickpoint (hatched line) and the downstream rejuvenated profile (continuous line). Legend: tKP – transient knickpoint; rKp – resistant knickpoint; Mt – schist and phyllite; Gr – granite; Hf – hornfels; Og – orthogneisse. In the inset Distance – Slope plots, fill circles correspond to the relict graded profile, crosses correspond to the rejuvenated profile located downstream the older transient knickpoint (tKP)

Saint-Quentin – 27 rue du Docteur Cordier

Identifiant de l'opération archéologique : 9271 Date de l'opération : 2007 (EX) Les six tranchées de sondage totalisant 400 m² ont été réalisées au 27 de la rue du docteur Cordier. Elles ont été exécutées sur 5 116 m², dont environ 2 200 m² sont concernés par les travaux de construction. Elles ont permis la mise au jour principalement d’un four à briques, de fosses d’extraction d’argile ainsi que d’une série d’ornières. Ces structures sont concentrées dans le nord-est de la parcelle 796. Le f..

SVOM pointing strategy: how to optimize the redshift measurements?

The Sino-French SVOM mission (Space-based multi-band astronomical Variable Objects Monitor) has been designed to detect all known types of gamma-ray bursts (GRBs) and to provide fast and reliable GRB positions. In this study we present the SVOM pointing strategy which should ensure the largest number of localized bursts allowing a redshift measurement. The redshift measurement can only be performed by large telescopes located on Earth. The best scientific return will be achieved if we are able to combine constraints from both space segment (platform and payload) and ground telescopes (visibility).Comment: Proceedings of Gamma-Ray Bursts 2007 conference, Santa Fe, USA, 5-9 November 2007. Published in AIP conf. proc. 1000, 585-588 (2008

Components of genetic counsellor education: A systematic review of the peer-reviewed literature.

The need for appropriately trained genetic counsellors to support genetic healthcare is now acknowledged. However, while programmes for education of genetic counsellors exist in a number of countries, these do not conform to any specific international standards. As genetic techniques, educational standards and professional standards have been evolved, and with increasing mobility of genetic counsellors, it is of great importance to have some comparison of education and training between different countries. This systematic review was conducted to determine the components of educational programmes for genetic counsellors worldwide that have been published in peer-reviewed literature. Databases were searched for studies published in English from 2000 to 2014 related to the topic. We identified 406 potential papers, of these, 11 studies met the inclusion criteria. The findings indicate that, in most cases, the theoretical components of genetic counsellor programmes conform to the recommendations and requirements of relevant professional bodies. However, clinical preparation of genetic counsellors in real-life professional practice settings seems to be less well addressed as this is essential to ensure genetic counsellors are able to provide safe patient care after graduation. Further work to gain agreement internationally on genetic counsellor education is needed

Pierrelatte – Les Blachettes, « Espace Moulins »

Identifiant de l'opération archéologique : 229609 Date de l'opération : 2007 (EX) Les sondages réalisés cette année concernent une partie de la parcelle 157 section YH, au lieudit des Blachettes, qui s’étend sur une surface de 3 ha. Au total trente-huit sondages sous forme de tranchées ont été réalisés. L’emprise de la parcelle repose sur la terrasse würmienne du Rhône ; malheureusement dans ce secteur le recouvrement sédimentaire est très peu important, entre 0,50 m et 0,80 m, ce qui ne fav..