Alien Registration- Dumont, Marie L. (Auburn, Androscoggin County)

https://digitalmaine.com/alien_docs/31233/thumbnail.jp

Snow spectral albedo at Summit, Greenland: measurements and numerical simulations based on physical and chemical properties of the snowpack

The broadband albedo of surface snow is determined both by the near-surface profile of the physical and chemical properties of the snowpack and by the spectral and angular characteristics of the incident solar radiation. Simultaneous measurements of the physical and chemical properties of snow were carried out at Summit Camp, Greenland (72°36´ N, 38°25´ W, 3210 m a.s.l.) in May and June 2011, along with spectral albedo measurements. One of the main objectives of the field campaign was to test our ability to predict snow spectral albedo by comparing the measured albedo to the albedo calculated with a radiative transfer model, using measured snow physical and chemical properties. To achieve this goal, we made daily measurements of the snow spectral albedo in the range 350–2200 nm and recorded snow stratigraphic information down to roughly 80 cm. The snow specific surface area (SSA) was measured using the DUFISSS instrument (DUal Frequency Integrating Sphere for Snow SSA measurement, Gallet et al., 2009). Samples were also collected for chemical analyses including black carbon (BC) and dust, to evaluate the impact of light absorbing particulate matter in snow. This is one of the most comprehensive albedo-related data sets combining chemical analysis, snow physical properties and spectral albedo measurements obtained in a polar environment. The surface albedo was calculated from density, SSA, BC and dust profiles using the DISORT model (DIScrete Ordinate Radiative Transfer, Stamnes et al., 1988) and compared to the measured values. Results indicate that the energy absorbed by the snowpack through the whole spectrum considered can be inferred within 1.10%. This accuracy is only slightly better than that which can be obtained considering pure snow, meaning that the impact of impurities on the snow albedo is small at Summit. In the near infrared, minor deviations in albedo up to 0.014 can be due to the accuracy of radiation and SSA measurements and to the surface roughness, whereas deviations up to 0.05 can be explained by the spatial heterogeneity of the snowpack at small scales, the assumption of spherical snow grains made for DISORT simulations and the vertical resolution of measurements of surface layer physical properties. At 1430 and around 1800 nm the discrepancies are larger and independent of the snow properties; we propose that they are due to errors in the ice refractive index at these wavelengths. This work contributes to the development of physically based albedo schemes in detailed snowpack models, and to the improvement of retrieval algorithms for estimating snow properties from remote sensing data

Evaluation of the noise properties of a dual-frequency VECSEL for compact Cs atomic clocks (Poster)

International audienceWe evaluate a dual-frequency and dual-polarization optically-pumped semiconductor laser emitting at 852 nm as a new laser source for compact atomic clocks based on the coherent population trapping (CPT) technique. The frequency difference between the laser modes is tunable to 9.2 GHz corresponding to the ground state hyperfine-split of Cs. Impact of the laser noise has been investigated. Laser relative intensity noise is limited by the pump-RIN transfer to a level of-110 dB/Hz. Laser frequency noise shows excess mechanical and technical noise resulting in a laser linewidth of 1 MHz at 1 s in lock operation. The noise performance and spectral properties of the laser are already adequate to realize CPT experiments and should result in Allan standard-deviation of the clock below 1 × 10-12 at 1 second

Transient self-potential anomalies associated with recent lava flows at Piton de la Fournaise volcano (Réunion Island, Indian Ocean)

International audienceSelf-potential signals are sensitive to various phenomena including ground water flow (streaming potential), thermal gradients (thermoelectric potential), and potentially rapid fluid disruption associated with vaporization of water. We describe transient self-potential anomalies observed over recent (< 9 years) lava flows at Piton de la Fournaise volcano (Reunion Island, Indian Ocean). Repeated self-potential measurements are used to determine the decay of the self-potential signals with time since the emplacement of a set of lava flow. We performed a 9 km-long self-potential profile in February 2004 in the Grand Brûlé area. This profile was repeated in July–August 2006. The second repetition of this profile crossed eight lava flows emplaced between 1998 and 2005 during seven eruptions of Piton de la Fournaise volcano. The self-potential data show clear positive anomalies (up to 330 mV) and spatially correlated with the presence of recent lava flows. The amplitude of the self-potential anomalies decreases exponentially with the age of the lava flows with a relaxation time of not, vert, similar 44 months. We explain these anomalies by the shallow convection of meteoric water and the associated streaming potential distribution but we cannot exclude possible contributions from the thermoelectric effect and the rapid fluid disruption mechanism. This field case evidences for the first time transient self-potential signals associated with recent volcanic deposits. It can be also a shallow analogue to understand the variation of self-potential signals in active geothermal areas and transient self-potential signals associated with dike intrusion at larger depths. The empirical equation we proposed can also be used to diagnose the cooling of recent lava flow on shield volcanoes

Genome-wide association study identifies 30 loci associated with bipolar disorder.

Bipolar disorder is a highly heritable psychiatric disorder. We performed a genome-wide association study (GWAS) including 20,352 cases and 31,358 controls of European descent, with follow-up analysis of 822 variants with P &lt; 1 × 10-4 in an additional 9,412 cases and 137,760 controls. Eight of the 19 variants that were genome-wide significant (P &lt; 5 × 10-8) in the discovery GWAS were not genome-wide significant in the combined analysis, consistent with small effect sizes and limited power but also with genetic heterogeneity. In the combined analysis, 30 loci were genome-wide significant, including 20 newly identified loci. The significant loci contain genes encoding ion channels, neurotransmitter transporters and synaptic components. Pathway analysis revealed nine significantly enriched gene sets, including regulation of insulin secretion and endocannabinoid signaling. Bipolar I disorder is strongly genetically correlated with schizophrenia, driven by psychosis, whereas bipolar II disorder is more strongly correlated with major depressive disorder. These findings address key clinical questions and provide potential biological mechanisms for bipolar disorder

Scalable Rules for Coherent Group Motion in a Gregarious Vertebrate

Individuals of gregarious species that initiate collective movement require mechanisms of cohesion in order to maintain advantages of group living. One fundamental question in the study of collective movement is what individual rules are employed when making movement decisions. Previous studies have revealed that group movements often depend on social interactions among individual members and specifically that collective decisions to move often follow a quorum-like response. However, these studies either did not quantify the response function at the individual scale (but rather tested hypotheses based on group-level behaviours), or they used a single group size and did not demonstrate which social stimuli influence the individual decision-making process. One challenge in the study of collective movement has been to discriminate between a common response to an external stimulus and the synchronization of behaviours resulting from social interactions. Here we discriminate between these two mechanisms by triggering the departure of one trained Merino sheep (Ovis aries) from groups containing one, three, five and seven naïve individuals. Each individual was thus exposed to various combinations of already-departed and non-departed individuals, depending on its rank of departure. To investigate which individual mechanisms are involved in maintaining group cohesion under conditions of leadership, we quantified the temporal dynamic of response at the individual scale. We found that individuals' decisions to move do not follow a quorum response but rather follow a rule based on a double mimetic effect: attraction to already-departed individuals and attraction to non-departed individuals. This rule is shown to be in agreement with an adaptive strategy that is inherently scalable as a function of group size

Haplotype analysis of TP53 polymorphisms, Arg72Pro and Ins16, in BRCA1 and BRCA2 mutation carriers of French Canadian descent

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Bibliothèques et sciences de l\u27information : quel dialogue ? - Programme

Face aux évolutions technologiques, scientifiques, économiques, sociales, culturelles et politiques de leur environnement, les bibliothèques en tant qu\u27organismes culturels et scientifiques doivent repenser leurs pratiques, leur positionnement économique, politique et institutionnel, et leur rôle social, culturel et scientifique. Dans ce contexte, qu\u27attendent les bibliothèques de la recherche ? Quels thématiques et projets de recherche répondraient à leurs besoins ? Les sciences de l\u27information peuvent-elles apporter des réponses aux enjeux actuels ? Pour répondre aux interrogations posées par ces nouveaux défis, le colloque croise les approches et expériences de bibliothécaires et chercheurs en sciences de l\u27information de nombreux pays ( France, Canada, Etats-Unis, Allemagne, Royaume-Uni...

Unlike for Human Monocytes after LPS Activation, Release of TNF-α by THP-1 Cells Is Produced by a TACE Catalytically Different from Constitutive TACE

Tumor necrosis factor-alpha (TNF-α) is a pro-inflammatory cytokine today identified as a key mediator of several chronic inflammatory diseases. TNF-α, initially synthesized as a membrane-anchored precursor (pro-TNF-α), is processed by proteolytic cleavage to generate the secreted mature form. TNF-α converting enzyme (TACE) is currently the first and single protease described as responsible for the inducible release of soluble TNF-α.Here, we demonstrated the presence on THP-1 cells as on human monocytes of a constitutive proteolytical activity able to cleave pro-TNF-α. Revelation of the cell surface TACE protein expression confirmed that the observed catalytic activity is due to TACE. However, further studies using effective and innovative TNF-α inhibitors, as well as a highly selective TACE inhibitor, support the presence of a catalytically different sheddase activity on LPS activated THP-1 cells. It appears that this catalytically different TACE protease activity might have a significant contribution to TNF-α release in LPS activated THP-1 cells, by contrast to human monocytes where the TACE activity remains catalytically unchanged even after LPS activation.On the surface of LPS activated THP-1 cells we identified a releasing TNF-α activity, catalytically different from the sheddase activity observed on human monocytes from healthy donors. This catalytically-modified TACE activity is different from the constitutive shedding activity and appears only upon stimulation by LPS