Advance and Retreat of Cordilleran Ice Sheets in Washington, U.S.A.

Cordilleran Ice Sheet glaciations show characteristic patterns of advance and retreat, consisting of (1) advance out outwash, (2) glacial scouring, (3) deposition of till, (4) deposition of recessional outwash south of Seattle in the southern Puget Lowland, glaciomarine drift in the northern lowland, and eskers, kames, and small moraines on the Columbia Plateau. Radiocarbon dates show that the Puget and Juan de Fuca lobes advanced and retreated synchronously. The Puget lobe backwasted to Seattle by 13.4-14 ka yrs BP, where the thinning ice floated in seawater northward to Canada by 13 ka yrs BP depositing glaciomarine drift contemporaneously over 18,000 km2. Compelling evidence against the backwasting, calving, terminus model for the origin of the glaciomarine drift includes: 1) abundant 14C dates demonstrate simultaneous deposition of glaciomarine drift over the entire area; 2) stagnant-ice deposits closely related to glaciomarine drift are not consistent with an actively-calving, backwasting terminus; 3) irrefutable evidence for the nonmarine origin of Deming sand shows that Cordilleran ice was absent immediately prior to deposition of the overlying glaciomarine drift. The pattern of events in the northern Puget Lowland includes: 1) glacial loading under 1800 m of ice during the Vashon maximum; 2) rapid glacial thinning and floating of the ice deposited Kulshan glaciomarine drift 12-13 ka yrs BP; 3) emergence and deposition of fluvial Deming sand 11.5 ka yrs BP; 4) resubmer-gence and deposition of Bellingham glaciomarine drift up to -200 m, well beyond global eustatic sea level rise; 5) emergence 10.5-11.5 ka yrs BP and deposition of Sumas outwash on Bellingham glaciomarine drift; 6) Holocene eustatic sea level rise kept pace with isostatic rebound, thus, post-Sumas marine terraces are absent.Dans la Cordillère, les glaciations se sont produites selon des modes caractéristiques d'avancée et de recul : 1) dépôts fluvioglaciaires d'avancée; 2) poli glaciaire; 3) till; 4) dépôts fluvio-glaciaires de retrait au sud de Seattle, dans le sud des basses-terres de Puget, dépôts glacio-marins dans les basses-terres du nord, et eskers, terrasses fluvioglaciaires et petites moraines sur le plateau de Columbia. La datation au radiocarbone indique que les lobes de Puget et de Juan de Fuca ont avancé et reculé synchroniquement. Parmi les preuves qui nous contraignent à rejeter l'hypothèse selon laquelle un front en fusion, qui vêlait, serait à l'origine des dépôts glacio-marins, citons : 1) les nombreuses datations au radiocarbone qui révèlent la mise en place simultanée de dépôts glacio-marins sur tout le territoire; 2) les dépôts issus de la fusion de la glace stagnante, intimement associés aux dépôts glacio-marins; 3) les preuves irréfutables d'une origine autre que marine des sables de Deming qui révèlent que la Cordillère était libre de glace immédiatement avant la mise en place des dépôts glacio-marins. Dans le nord des basses-terres de Puget le déroulement des événements comprend les étapes suivantes : 1) au cours du maximum de Vashon, charge glaciaire sous 1800 m de glace; 2) 12-13 ka BP, amincissement rapide du glacier et dérive de la glace contribuant à la mise en place des dépôts glacio-marins de Kulshan; 3) vers 11 500 ans BP, emersion et dépôt des sables de Deming d'origine fluviale; 4) nouvelle submersion et mise en place des dépôts glacio-marins de Bellingham jusqu'à une hauteur d'environ 200 m, bien supérieure à l'élévation eustatique du niveau de la mer; 5) vers 10 500-11 500 ans BP, emersion et mise en place des dépôts fluvio-glaciaires de Sumas sur les dépôts glacio-marins de Bellingham; 6) à l'Holocène, élévation eustatique du niveau de la mer au même rythme que le relèvement isostatique.Die Vereisung der Kordilleren-Eisdecke zeigt charakteristische VorstoB- und Rùckzugsmuster, bestehend aus (1) glazialem SchwemmvorstoB, (2) glazialem Scheuern, (3) Ablagerung der Grundmoràne, (4) Ablagerung von Rùckzugsschwemm-Material sùdlich von Seattle im sûdlichen Puget-Lowland, glaziomarines Material im nôrdlichen Tiefland und Esker, Kames und kleine Morànen auf dem Columbia-Plateau. Radiokarbondaten zeigen, daf3 die Puget - und Juan de Fuca-Loben gleichzeitig vorstieBen und sich zurûckzogen. Gegen das rùcklàufige, kalbende Terminus-Modell fur den Ursprung des glaziomarinen Materials sprechen die folgenden Tatsachen in zwingender Weise: 1) zahlreiche '"C-Daten beweisen die gleichzeitige Ablagerung von glaziomarinem Material ùber das gesamte Gebiet; 2) Ablagerungen von stagnierendem Eis, die in enger Verbindung zu glaziomarinem Material stehen, stimmen nicht mit einem aktiv kalbenden rùcklàufigen Terminus ùberein; 3) unwiderlegbares Beweismaterial fur den nichtmarinen Ursprung des Sands von Deming zeigt, daB es kein Kordilleren-Eis gab unmittelbar vor der Ablagerung darùberliegen-den glaziomarinen Materials. Die Abfolge der Ereignisse im nôrdlichen Puget Lowland bein-haltet: 1) glaziale Fracht unter 1800 m Eis wàhrend des Vashon Maximums; 2) schnelles glaziales Ausdùnnen und treibendes Eis lagerte 12-13 ka Jahre v.u.Z. das glazioma-rine Material von Kulshan ab; 3) Auftauchen und Ablagerung von Deming-FluBsand -11.5ka Jahre v.u.Z.; 4) Wiederuntertauchen und Ablagerung von glaziomarinem Belligham-Material bis zu - 200 m, weit ùber die globale eustatische Meeresan-hebung hinaus; 5) Auftauchen - 10.5-11.5 ka Jahre v.u.Z. und Ablagerung von Sumas-Schwemm-Material auf dem glaziomarinen Bellingham-Material; 6) die eustatische Anhebung des Meeresspiegels im Holozàn hielt Schritt mit dem isostatischen Ruckprall

Assessing climate model software quality: a defect density analysis of three models

A climate model is an executable theory of the climate; the model encapsulates climatological theories in software so that they can be simulated and their implications investigated. Thus, in order to trust a climate model, one must trust that the software it is built from is built correctly. Our study explores the nature of software quality in the context of climate modelling. We performed an analysis of defect reports and defect fixes in several versions of leading global climate models by collecting defect data from bug tracking systems and version control repository comments. We found that the climate models all have very low defect densities compared to well-known, similarly sized open-source projects. We discuss the implications of our findings for the assessment of climate model software trustworthiness

“Finding rhythms made me find my rhythm in prison”: the role of a music program in promoting social engagement and psychological well-being among inmates

This article presents a mixed-methods evaluation of the Finding Rhythms (FR) charity music program in U.K. prisons. Results across two studies indicate that FR group activities and the development of a shared FR identity lead to a positive well-being outcome. Furthermore, FR involvement dissolves rivalries between prisoners and provides them with a sense of purpose that extends into prison life and beyond. We provide evidence for the social cure properties of the FR group and the music program that promotes social engagement and psychological well-being among inmates

“I changed and hid my old ways”: how social rejection and social identities shape wellbeing among ex-prisoners

Being a member of a rejected group negatively affects well‐being but can also increase group identification, which can have positive effects on well‐being. However, this rejection‐identification model has never been investigated among the highly stigmatized group of ex‐prisoners. Furthermore, the potential buffering role of multiple group memberships has never been investigated within the rejection‐identification model. We conduct a novel investigation of a combined rejection‐identification and social cure model of group‐based rejection among ex‐prisoners. A survey of 199 ex‐prisoners found that experiencing group‐based rejection was associated with poorer well‐being and increased ex‐prisoner identification. However, identification as an ex‐prisoner magnified, rather than buffered, the relationship between rejection and reduced well‐being. Furthermore, the negative relationship between rejection and well‐being was particularly pronounced among ex‐prisoners with a higher number of group memberships. Ex‐prisoners with a greater number of group memberships experienced greater levels of rejection, suggesting group memberships increase their exposure to rejection. We therefore provide evidence of a boundary condition for the social cure properties of groups. Among members of strongly rejected social groups, multiple group memberships can be a social curse rather than social cure

Improving refugee well-being with better language skills and more intergroup contact

The effects of intergroup contact on prejudice are well established. However, its effects on minority group well-being have been rarely studied. We hypothesised that contact with members of the majority culture will be related to better well-being, and that this is facilitated by majority language proficiency. We tested this hypothesis in a three-wave longitudinal study of refugees over two years (N = 180). Cross-lagged path modelling confirmed that intergroup contact at earlier time points was associated with increased well-being at later time points; the reverse associations (from earlier well-being to later contact) were not reliable. Self-rated earlier English language competence was positively associated with later intergroup contact (but not the reverse), suggesting that improving majority language proficiency might be the key to better well-being of refugees, with intergroup contact being the mediator between language and well-being

Sub-optimal CD4 reconstitution despite viral suppression in an urban cohort on Antiretroviral Therapy (ART) in sub-Saharan Africa: Frequency and clinical significance

<p>Abstract</p> <p>Background</p> <p>A proportion of individuals who start antiretroviral therapy (ART) fail to achieve adequate CD4 cell reconstitution despite sustained viral suppression. We determined the frequency and clinical significance of suboptimal CD4 reconstitution despite viral suppression (SO-CD4) in an urban HIV research cohort in Kampala, Uganda</p> <p>Methods</p> <p>We analyzed data from a prospective research cohort of 559 patients initiating ART between 04/04–04/05. We described the patterns of SO-CD4 both in terms of:- I) magnitude of CD4 cell increase (a CD4 count increase < 50 CD4 cells/μl at 6 months, <100 cells/μl at 12 months; and <200 cells/μl at 24 months of ART) and II) failure to achieve a CD4 cell count above 200 cells/μl at 6,12 and 24 months of ART. Using criteria I) we used logistic regression to determine the predictors of SO-CD4. We compared the cumulative risk of clinical events (death and/or recurrent or new AIDS-defining illnesses) among patients with and without SO-CD4.</p> <p>Results</p> <p>Of 559 patients initiating ART, 386 (69%) were female. Median (IQR) age and baseline CD4 counts were 38 yrs (33–44) and 98 cells/μl (21–163) respectively; 414 (74%) started a d4T-based regimen (D4T+3TC+NVP) and 145 (26%) a ZDV-based regimen (ZDV+3TC+EFV). After 6, 12 and 24 months of ART, 380 (68%), 339 (61%) and 309 (55%) had attained and sustained HIV-RNA viral suppression. Of these, 78 (21%), 151 (45%) and 166 (54%) respectively had SO-CD4 based on criteria I), and 165(43%), 143(42%) and 58(19%) respectively based on criteria II). With both criteria combined, 56 (15%) and 129 (38%) had SO-CD4 at 6 and 12 months respectively. A high proportion (82% and 58%) of those that had SO-CD4 at 6 months (using criteria I) maintained SO-CD4 at 12 and 24 months respectively. There were no statistically significant differences in the incidence of clinical events among patients with [19/100PYO (12–29)] and without SO-CD4 [23/100PYO (19–28)].</p> <p>Conclusion</p> <p>Using criteria I), the frequency of SO-CD4 was 21% at 6 months. Majority of patients with SO-CD4 at 6 months maintained SO-CD4 up to 2 years. We recommend studies of CD4 T-cell functional recovery among patients with SO-CD4.</p

Validating Requirements for Fault Tolerant Systems Using Model Checking

Model checking is shown to be an effective tool in validating the behavior of a fault tolerant embedded spacecraft controller. The case study presented here shows that by judiciously abstracting away extraneous complexity, the state space of the model could be exhaustively searched allowing critical functional requirements to be validated down to the design level. Abstracting away detail not germane to the problem of interest leaves by definition a partial specification behind. The success of this procedure shows that it is feasible to effectively validate a partial specification with this technique. Three anomalies were found in the system one of which is an error in the detailed requirements, and the other two are missing/ambiguous requirements. Because the method allows validation of partial specifications, it also is an effective methodology towards maintaining fidelity between a co-evolving specification and an implementation

Accessing the phenomenon of incompatibility in working students’ experience of university life

University students in paid employment have less time for studying, report more stress, and participate in fewer extracurricular activities than non-employed students. These negative outcomes that result from combining work and study can cause employed students to experience the domains of work, study, and social life as practically incompatible, but also to experience a sense of identity incompatibility. Therefore, we used insights from previous quantitative and qualitative data on employed students and previous work on identity incompatibility to generate two research questions (RQs): RQ1. What type(s) of incompatibility (practical, identity or other) do employed students experience? and RQ2. What strategies have they adopted to reduce the experienced incompatibility? In order to answer these questions, we performed a thematic analysis with a deductive approach on transcripts from 21 UK university students who we interviewed. The students reported two types of incompatibilities: practical incompatibility, which stems from the lack of time, lack of energy, and lack of social contact associated with combining work and study; and identity incompatibility, which emanates from status differences and differences between one’s own and others’ perception of oneself. In order to reduce or resolve these incompatibilities, the students also developed practical (e.g. taking paid leave) and cognitive (e.g. compartmentalising contexts) strategies. Finally, the students also noted how the experience of practical incompatibility can reaffirm their values of hard work and productivity and make them resilient learners

Tackling educational inequalities with social psychology: identities, contexts, and interventions

Some groups of students—typically those who have suffered because of historical inequality in society—disproportionately experience psychological barriers to educational success. These psychological barriers—feelings of threat to their social identity and the sense that their identity is incompatible with educational success—make substantial contributions to inequalities in educational outcomes between groups, even beyond economic, historical, and structural inequalities. A range of wise psychological interventions can help remove these barriers by targeting students’ subjective interpretation of their local educational context. In this review, we outline the Identities in Context model of educational inequalities, which proposes that interactions between students’ social identities and features of the local educational context—expectations about a group's academic performance, a group's representation in positions associated with academic success, and a group's orientation towards education—can trigger social identity threat and identity incompatibility in ways that vary considerably across contexts. We present an implementation process, based on the Identities in Context model, that academic researchers, policymakers, and practitioners can follow to help them choose and tailor wise interventions that are effective in reducing educational inequalities in their local context. Throughout the review, we make policy recommendations regarding how educational practices can be altered to help remove psychological barriers for underperforming groups of students and so reduce educational inequalities