Crackdown

The poems of Crackdown follow the progress of The Spiritual Exercises of St. Ignatius Loyola written in the 16th century. Like the Exercises, the poems are divided into sections which correspond to the week on sin and reform ( Translations/Valley of the Shadow\u27), the week on the life of Christ ( Translations/The Call of the Temporal King ), the week on the Passion ( Translations/Crackdown ), and the week on the Resurrection ( Translations/Apparition ). The work is framed by Translations/An Approach which acknowledges the Anima Christi prayer at the beginning of the Exercises as an embedded acrostic; Each section begins with a prayer and several preludes clarified by points. The first preludes ask that we imaginatively place ourselves in a spatial and sensory relationship to the mysteries under consideration, and from that vantage point, pray for what we want. I chose to render these spaces literally, in the first section, as an apartment complex and in the second, as a car on Highway 99. The points I have also considered spatially. For me, the diamond shape seemed an appropriate way to envision natural personal and collective goodness moving out expansively, and sin as a kind of narrowing to a point of no return. The use of an enclosure for the second group of points serves to illustrate the planet\u27s finitude and the fact that our sayings and doings are linked within that finitude for better and worse; The final section concerns the thirteen apparitions of Christ after his resurrection. I chose rather to render the evidence of divinity the only way I receive it--through the beauties of the natural world and through exceptional human beings. It seems to me that the process of poetry is intimately linked with the process of faith and that both are fed and strengthened by deep attentiveness and receptivity to all that life extends. I chose the Exercises as a means of bringing the two into mutual service

Developing productive learning mindsets in a freshman calculus course : an exploratory study

The promotion of belonging, purpose, and growth mindset through subtle social psychological interventions has been shown to positively impact student outcomes (Lazowski & Hulleman, 2016; Walton & Cohen, 2007; Yeager & Walton, 2011; Yeager et al., 2016). This study explores how instructor messaging and intentional course design can promote productive learning mindsets and influence student attributions of struggle or failure over time. Open-ended interviews were conducted with 15 former calculus students more than one year after the calculus course ended. A cross-case analysis was used to generate themes representative of shared experiences across interviewed students. The method of constant comparison was used to refine codes and group codes into categories using axial coding (Strauss & Corbin, 1998). Findings from this analysis suggested that students’ experiences in this introductory calculus course broadened their perspectives and taught them how to persist through challenging course work. Many students intimated that their experiences in calculus increased their confidence in their mathematical skill and their ability to be successful in difficult courses moving forward. Students described how they changed their behavior in response to the difficulty of the course and the supportive structures built into the class (e.g., homework help sessions, exam reviews, student study groups). The findings suggest that explicit instructor messaging targeting learning mindsets is most effective when the course design reinforces those messages.Curriculum and Instructio

Spontaneous symmetry-breaking in trilayer graphene

Multilagen-Graphen besteht aus mehreren atomar dünnen Schichten von Kohlenstoffatomen und weist eine Vielzahl ungewöhnlicher elektrischer Eigenschaften auf. Unter anderem wurde vorhergesagt, dass abhängig von externen elektrischen und magnetischen Feldern und je nach Lagenfolge der einzelnen Kohlenstofflagen der Grundzustand des Systems in einen korrelierten Zustand übergehen kann, der spontan Symmetrien des Systems bricht. Diese Zustände sind aber typischerweise sehr instabil und können nur in hochreinen Proben mit homogener Lagenfolge sichtbar gemacht werden. Im ersten Teil dieser Arbeit wurden die elektrischen Eigenschaften dieser korrelierten Zustände sowohl in Dreilagen-Graphen mit Bernal-Lagenfolge (ABA) als auch in Dreilagen-Graphen mit rhomboedrischer (ABC) Lagenfolgen genauer untersucht: In ABA Dreilagen-Graphen ist die Bandstruktur stark von externen elektrischen Feldern abhängig und bildet bei stärker werdenden Feldern mehrere zusätzliche Dirac-Kegel um den zentralen Dirac-Punkt der Bandstruktur aus. In dieser Arbeit wird gezeigt, dass mithilfe elektrischer und magnetischer Felder die Elektron-Elektron Wechselwirkung innerhalb der Dirac-Kegel verstärkt werden kann, bis der Grundzustand kontrolliert in einen korrelierten Zustand übergeht, der die Rotationssymmetrie des Systems spontan bricht. Anders verhält es sich in ABC Dreilagen-Graphen, dessen elektrische Struktur eine starke Berry-Krümmung und chirale Quasiteilchen aufweist. Als Folge davon wurde unter anderem vorhergesagt, dass bei verschwindender Ladungsträgerdichte mehrere spontane Quanten-Hall-Zustände auftreten können, die die chirale Symmetrie des Systems brechen. Messungen der Magnetotransporteigenschaften bei verschiedenen elektrischen und magnetischen Felder lassen ein vielfältiges Phasendiagramm der Quanten-Hall-Zustände erkennen, dass sogar Zustände mit intrinsischem orbitalem magnetischem Moment und Hall-Leitfähigkeit beinhaltet. Diese Erkenntnisse tragen zum tieferen Verständnis der korrelierten Zustände in Multilagen-Graphen und der Wechselwirkung von Ladungsträgern in zweidimensionalen Materialien bei. Im zweiten Teil der Arbeit wird der Ladungstransport in anorganischen Halogenid-Perowskit Nanodrähten untersucht. Halogenid-Perowskit Materialien haben aufgrund ihrer außergewöhnlichen optoelektronischen Eigenschaften bereits vielfach Anwendung als Basismaterial für Solarzellen und Photodetektoren gefunden. In diesem Teil der Arbeit wird der Ladungstransport in Feldeffekt-Transistoren mit CsPbBr3 Perowskit Nanodrähten in Abhängigkeit der Temperatur untersucht. Es wird gezeigt, dass ohne Beleuchtung der Probe der Ladungstransport stark von tiefen Fallzuständen dominiert wird und bei niedrigen Temperaturen komplett ausfriert. Wenn die Probe jedoch beleuchtet wird, steigt die Mobilität der Ladungsträger stark an und wird bei niedrigen Temperaturen nur von der Phononenstreuung limitiert. Diese Ergebnisse unterstreichen die Defekt-Toleranz, die häufig mit Perowskit-Materialien in Verbindung gebracht wird und liefern neue Einsichten in die elektrischen Fallenzustände in CsPbBr3 Perowskit-Nanodrähten.In recent years, multilayer graphene, a stack of several atomically thin layers of carbon atoms, has attracted growing interest due to its intriguing electronic properties and exceptional tunability. Depending on its stacking order, multilayer graphene has been predicted to be susceptible to a variety of correlated broken-symmetry ground states that can be accessed and explored upon appropriate tuning of its electronic structure via electrostatic gating and magnetic fields. However, in order to reveal these fragile states, excellent device quality and stacking order homogeneity are prerequisite. In this thesis, magnetotransport in Bernal-stacked (ABA) trilayer graphene encapsulated in hexagonal boron nitride as well as suspended rhombohedral (ABC) trilayer graphene is investigated. Depending on the stacking order, two families of correlated states that spontaneously break symmetries of the system are observed. In ABA trilayer graphene, external electric fields strongly deform the band structure and lead to the emergence of multiple off-center Dirac points (Dirac gullies). It is demonstrated that electric and magnetic fields can be used as tuning parameters to enhance electron-electron interactions within these Dirac gullies. At appropriate tuning, magnetotransport maps indicate the emergence of a new correlated ground state that spontaneously breaks the rotational symmetry of the system. In contrast, ABC trilayer graphene hosts chiral quasi-particles that exhibit a non-zero Berry phase when encircling one of the valleys of its band structure. It has been shown, that ABC trilayer graphene is susceptible to spontaneous chiral symmetry breaking due to its flat band structure at charge neutrality. Indeed, transport measurements demonstrate the emergence of several spontaneous quantum Hall phases that are driven by a giant Berry curvature. Mapping magnetostransport as a function of electric and magnetic fields reveals a rich phase diagram including states with non-zero orbital momentum and Hall conductivity. The findings of this thesis provide novel insights into the world correlated phases in multilayer graphene and interaction physics in two dimensions. In a second part of this thesis, charge transport in all-inorganic halide perovskite nanowires is investigated. In recent years, halide perovskites have emerged as promising novel materials for optoelectronic applications due to their large absorption coefficient and exceptional charge carrier lifetime. Yet, although the optical properties have been studied intensely, charge transport mechanisms and the influence of traps still remains elusive. In this thesis, temperature dependent charge transport in CsPbBr3 nanowire field-effect transistors is investigated. It is shown, that charge transport in the dark is dominated by deep traps and freezes out at low temperatures. However, illuminating the sample increases the mobility several orders of magnitude revealing even phonon-limited transport characteristics. These findings highlight and extend the notion of “defect-tolerance” of perovskite materials and provide novel insights into defect states in CsPbBr3 nanowires

Combining and Steganography of 3D Face Textures

One of the serious issues in communication between people is hiding information from others, and the best way for this, is deceiving them. Since nowadays face images are mostly used in three dimensional format, in this paper we are going to steganography 3D face images, detecting which by curious people will be impossible. As in detecting face only its texture is important, we separate texture from shape matrices, for eliminating half of the extra information, steganography is done only for face texture, and for reconstructing 3D face, we can use any other shape. Moreover, we will indicate that, by using two textures, how two 3D faces can be combined. For a complete description of the process, first, 2D faces are used as an input for building 3D faces, and then 3D textures are hidden within other images.Comment: 6 pages, 10 figures, 16 equations, 5 section

Seismic modelling and paleoceanography at DSDP Site 574

The analysis of high-resolution watergun seismic profiles collected in support of DSDP Leg 85 drilling reveals sev eral major, regionally traceable reflectors that can be correlated over more than 360,000 km2 in the central equatorial Pacific. Synthetic seismograms generated from shipboard physical property measurements (carefully corrected to in situ values) for DSDP Site 574 show excellent agreement with the field records; the agreement suggests that the traveltime to-depth conversion is accurate and permits the precise (± 5 m) location of reflectors in the cored section. The reflectors can be dated (±0.5 Ma) as follows: Orange, 21.5 to 22.5 Ma; Yellow, 20.5 to 21.5 Ma; Lavender, 16 to 17 Ma; Red, 13.5 to 14.5 Ma; Purple, 11 to 12 Ma; Brown, 7 to 8 Ma; and Green, 3 to 4 Ma. Similar analyses at the other Leg 85 sites result in identical ages. The reflectors are thus time surfaces; this chapter relates them to major paleoceanographic events and changes in the relative sea-level curve. The Orange and Yellow reflectors are associated with a marked increase in δ 1 3C, a major change in planktonic foraminiferal assemblages, the development of the deep Circum-Antarctic Current, and the establishment of steep thermal gradients between tropical and polar regions. This reorganization of the oceanic circulation system was probably a response to the opening of the Drake Passage, and it resulted in changes in the chemistry of tropical Pacific waters that caused the induration (and thus impedance contrasts) associated with these reflectors. The Lavender reflector is associated with a large carbonate minimum, the Chron 16 carbon shift, a widespread hiatus (NH2), major eustatic sea-level fluctuations, and a significant increase in silica deposition in the Pacific. It is not associated with 18O enrichment or climatic cooling. We conclude that this event represents an intensification in Antarc tic Bottom Water (AABW) circulation and the partitioning of silica between the Atlantic and the Pacific, caused by the introduction of North Atlantic Deep Water (NADW) in response to paleobathymetric and tectonic events. The Red re flector is associated with a subdued carbonate minimum, a widespread hiatus (NH3), a sea-level drop, significant changes in microfossil assemblages, and a major increase in δ 1 8 that has been linked with the buildup of Antarctic ice. Detailed isotopic analyses reveal that this isotopic shift occurred within an interval of 30,000 yr. and precisely at the depth of the Red reflector. The Purple reflector is associated with an extremely large carbonate minimum, a change in the style of carbonate deposition in the Pacific, a major lithologic boundary, a widespread hiatus (NH4), an increase in the provincialism be tween low and high latitudes in all planktonic microfossil assemblages, an apparent fall in eustatic sea level, an enrich ment in δ 1 8 , and a major North Atlantic reflector interpreted as representing an intensification of North Atlantic bot tom-water circulation. The Brown reflector is roughly associated with a small carbonate minimum, an enrichment in δ 1 8 , the late Miocene 1 3C depletion, a drop in the relative sea-level curve, and major faunal changes. The Green reflector is associated with a large carbonate minimum, an enrichment in δ 1 8 , a major western North Atlantic erosional event, and a widespread eastern Atlantic seismic reflector. The bulk of evidence supports correlation with the onset of Northern Hemisphere glaciation, but detailed isotopic analyses indicate that this isotopic event may be linked to the establishment of colder bottom waters without major ice-sheet development. Several types of reflectors have been identified. The reflectors in the older section result from diagenetic effects; the regionally correctable reflectors are associated with global events. In the younger (post-18 Ma) section, local reflectors are characterized by velocity contrasts, whereas regional reflectors are associated with density contrasts caused by car bonate minima. Two modes of generation of carbonate minima (and thus of reflectors) spanning the equatorial Pacific are (1) the intensification of AABW without the concurrent intensification of NADW and so without fractionation of silica between the Atlantic and the Pacific; this mode results in the less extreme carbonate minima; and (2) the intensifi cation of AABW in response to the intensification of NADW; this mode results in extreme carbonate minima and a cor relation of equatorial Pacific reflectors with North Atlantic events

Basement structure of the northern Ontong Java Plateau

Site surveys conducted in conjunction with Leg 130 on the Ontong Java Plateau reveal a strong seismic reflector at 0.8 to 1.0 s below the seafloor that drilling at Sites 803 and 807 confirmed is Cretaceous basalt. This reflector is generally smooth, except for the northeastern margin of the plateau, where it forms a series of small, irregularly shaped depressions. Correlatable reflectors present at the bottom of the depressions are also present on the adjacent highs, suggesting that these depressions are original volcanic topography. A strong sub-basalt reflector occurs on many seismic profiles on the northeastern portion of the plateau. This reflection may be caused by a density and velocity contrast between pillow lavas and flood basalt flows or it may result from interbedded sediment and thus may represent significant lulls in volcanic activity. The presence of sub-basalt reflectors near Site 803 may indicate that later volcanic episodes occurred there, in contrast to Site 807, where this reflector was not observed and where older basalt ages were obtained

Associations of dyslipidaemia and lipid-lowering treatment with risk of postoperative cognitive dysfunction: a systematic review and meta-analysis

BACKGROUND: Lipid imbalance is linked to age-related cognitive impairment, but its role in postoperative cognitive dysfunction (POCD) is unknown. Here, we present a systematic review and meta-analysis on dyslipidaemia, lipid-lowering treatment and POCD risk. METHODS: PubMed, Ovid SP and Cochrane databases were searched for longitudinal studies that reported on associations of any measure of dyslipidaemia and/or lipid-lowering treatment with POCD as relative risks (RRs) or ORs. Fixed-effects inverse variance models were used to combine effects. RESULTS: Of 205 articles identified in the search, 17 studies on 2725 patients (grand mean age 67 years; mean age range 61-71 years) with follow-up periods of 1 day to 4 years (median 7 days; IQR 1-68 days) were included. Studies focused almost exclusively on hypercholesterolaemia as a measure of dyslipidaemia and on statins as lipid-lowering treatment. Across 12 studies on hypercholesterolaemia, we found no association with POCD risk (RR 0.93; 95% CI 0.80 to 1.08; P=0.34). Statin use before surgery was associated with a reduced POCD risk across eight studies (RR 0.81; 95% CI 0.67 to 0.98; P=0.03), but data on treatment duration were lacking. CONCLUSION: Statin users appear to be at reduced risk of POCD although hypercholesterolaemia per se may not be associated with POCD risk. Trial studies are needed to evaluate the usefulness of statins in POCD prevention

Hypertension and risk of post-operative cognitive dysfunction (POCD): a systematic review and meta-analysis

BACKGROUND: Post-operative cognitive dysfunction (POCD) occurs frequently after major surgery. Hypertension is well-established as a risk factor for age-related cognitive impairment, but it is unclear whether or not it also increases the risk of POCD. OBJECTIVE: To evaluate the role of hypertension in POCD risk in a systematic review and meta-analysis. METHOD: PubMed, Ovid SP and the Cochrane Database of Systematic Reviews were searched for longitudinal studies of adults undergoing surgery with reporting of hypertension, blood pressure and/or anti-hypertensive treatment associations with POCD as relative risks or odds ratios. Fixed-effects meta-analyses were performed using Review Manager (version 5.3). RESULTS: Twenty-four studies on 4317 patients (mean age 63 years) were included. None of the studies had set out to assess hypertension as a risk factor for POCD. Hypertension was used as a categorical predictor throughout and only 2 studies adjusted for potential confounders. Across all 24 studies, hypertension was not significantly associated with POCD risk (RR 1.01; 95% CI 0.93, 1.09; p=0.82), though among 8 studies with >75% males, we found hypertension associations with a 27% increased risk of POCD (RR 1.27, 95% CI 1.07, 1.49; p=0.005). CONCLUSION: Our findings do not support the hypothesis that hypertension is a risk factor for POCD. However, since none of the studies included in our analysis were hypothesis-driven and most did not adjust for potential confounders, further systematic investigations are needed to evaluate the role of hypertension in the epidemiology of POCD