Internal Horizons Research Articles

“I didn't feel like I could trust her and that felt really risky”: a phenomenographic exploration of how Australian Midwives describe intrapartum risk

ObjectiveConcepts of intrapartum risk are not well explored in the Australian context. In response to an increasing focus on risk in maternity care, we sought to obtain insight into what Australian midwives conceptualised as intrapartum risk. DesignThe research was conducted using a phenomenographic approach. Following ethical approval, in-depth semi-structured interviews were used to determine the qualitatively different ways midwives conceptualise intrapartum risk. SettingThis project was undertaken across different midwifery practice settings in Australia. ParticipantsAustralian midwives (n=14) with expertise in caring for women in the intrapartum period volunteered to participate in the study. FindingsWhen discussing their experience of intrapartum risk, midwives focused on the external horizon of the woman as the risk, that included the internal horizons of being labelled as clinically high risk, working relationships within transdisciplinary risk and institutional risk. Risks were orientated toward the woman as well as to the midwives. Key conclusionsThe midwives in this study conceptualised that intrapartum risk was associated with the woman including being labelled as high risk in addition to certain challenges within the midwife-woman relationship, particularly if there was a lack of reciprocal trust. Implications for practiceThis study supports current evidence that improved collaborative professional relationships are integral to safety in maternity care. It reinforces continuity of midwifery care as important, and particularly as a way of mitigating intrapartum risk. Further research is required to inform what challenges experienced in the midwife-woman relationship contribute to concepts of risk.

Timelapse of the geomorphologic and stratigraphic evolution of a Late Cretaceous deep-sea fan, northern Santos basin, Brazil

Deep-sea fans are the terminal sinks of clastic sediment, nutrients and pollutants produced in continental landmasses. They are also major targets for oil and gas on continental margins. Several recent studies have applied seismic geomorphology to delineate deep-sea fans, however, most of them describe a relatively short period of the geologic time, disfavoring the observation of long-term geomorphologic changes and the resulting depositional architecture. We analyzed the geomorphologic evolution and architecture of the Maastrichtian, deeply buried, Maricá deep-sea fan in northern Santos Basin, offshore SE Brazil. Using three-dimensional seismic data and logs from three wells, we mapped five horizons (stratal slices), including fan base, fan top and three internal horizons. The examination of lobes and channel networks on each horizon resulted in a timelapse that capture major geomorphologic transformations of the deep-sea fan from inception to abandonment. The Maricá deep-sea fan is a sand-rich system deposited directly onto the irregular topography of the Maricá mass-transport deposit, and its geometry is also influenced by structural highs uplifted by active halokinesis. Six lobes were mapped, which present variable growing patterns and associated stratigraphic signatures indicative of aggradation, progradation, retrogradation, and lateral switching. Four types of channel morphology were identified (straight, sinuous, meandering, and braided-like). Channel length and sinuosity tend to increase with time in the whole fan and within individual lobes. Amplitude maps and well-log motifs suggest that sandy sediments occur mainly as channel-fill deposits and that different channel morphologies produce contrasting stratigraphic architectures and reservoir heterogeneities. Our results show that channel network and sand-body architecture evolve in a predictive fashion mostly controlled by fan aggradation. However, the interaction with the underlying topography causes morphologic changes at the lobe and depositional element scale that often deviate from the overall trend and affect sand distribution across the fan surface.

Art therapeutic practices for coping with stress in the conditions of COVID 19

The connection between people and art for centuries has provided an opportunity to stabilize the psychological state, their personal development and well-being. Today, in the conditions of "new normal" art therapy is desirable and offers us opportunities to deal with the crisis, reveals internal horizons for self-development. Positive thoughts and feelings fill a person when is engaged in creative activity. The present study marks the beginning of a study related to the impact of art therapy practices on a people emotional state in conditions of social isolation.

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A Novel Range Processing Method of Surface-Based FMCW Ice-Sounding Radar for Accurately Mapping the Internal Reflecting Horizons in Antarctica

In this article, we establish the nonlinear signal model of the surface-based frequency-modulated continuous wave ice-sounding radar, and propose a novel range processing strategy that aims at removing the frequency ramp nonlinearity effectively. The proposed algorithm takes full consideration of the dependence of nonlinearity on the round-trip delay time while providing certain robustness of noise. The theory analysis and implementation steps of the proposed algorithm are demonstrated. The full-scale simulations with different kinds of nonlinearities and various signal-to-noise ratios verify the effectiveness and robustness of the proposed algorithm. We also apply the proposed method to real dataset collected during the 31st Chinese Antarctic Research Expedition (CHINARE 31) and CHINARE 33. The result shows the effectiveness of our algorithm on illustrating clarified internal reflecting horizons of ice sheets. Compared with the echograms processed by the typical range processing scheme, our algorithm performs better in nonlinearity elimination.

Age stratigraphy in the East Antarctic Ice Sheet inferred from radio-echo sounding horizons

Abstract. The East Antarctic Ice Sheet contains a wealth of information that can be extracted from its internal architecture such as distribution of age, past flow features, and surface and basal properties. Airborne radar surveys can sample this stratigraphic archive across broad areas. Here, we identify and trace key horizons across several radar surveys to obtain the stratigraphic information. We transfer the age–depth scales from ice cores to intersecting radar data. We then propagate these age scales across the ice sheet using the high fidelity continuity of the radar horizons. In Dronning Maud Land, including Dome Fuji, we mapped isochrones with ages of 38 and 74 ka. In the central region of East Antarctica around Dome Concordia, Vostok and Dome Argus, we use isochrone ages of 38, 48, 90 and 161 ka. Taking together both regions, we provide isochrone depths traced along a combined profile length of more than 40 000 km and discuss uncertainties of the obtained stratigraphy, as well as factors important to consider for further expansion. This data set is the most extensive distribution of internal horizons in East Antarctica to date. The isochrone depths presented in this study are available on PANGAEA (https://doi.org/10.1594/PANGAEA.895528; Winter et al., 2018).

Two Horizons of Fusion

ABSTRACTIn this paper, we aim to differentiate the internal and external horizons of fusion. Fusion in the internal horizon relates to the structure and meaning of the object of learning as experienced by the learner. It clarifies the interrelationships among an object's critical features and aspects. It also illuminates the part-whole relationships of these features and aspects with the object itself. Fusion in the external horizon elucidates the relationships between the object of learning and its environment as seen by the learner. These relationships extend beyond the object's boundaries. This paper uses classroom data to show how these two horizons of fusion function at different levels and scopes to help learners achieve a deeper understanding of objects of learning.

Evolution of a high-latitude sediment drift inside a glacially-carved trough based on high-resolution seismic stratigraphy (Kveithola, NW Barents Sea)

Abstract Kveithola is a glacially-carved, E-W trending trough located in the NW Barents Sea, an epicontinental shelf sea of the Arctic Ocean located off northern Norway and Russia. A set of confined sediment drifts (the “Kveithola Drift”) is located in the inner part of the trough. In general, drift deposits are commonly characterized by high lateral continuity, restricted occurrence of hiatuses and relatively high accumulation rates, and thus represent excellent repositories of paleo-environmental information. We provide for the first time a detailed morphological and seismostratigraphic insight into this sediment drift, which is further supported by some preliminary lithological and sedimentological analyses. The complex morphology of the drift, imaged by combining all available multibeam data, includes a main and a minor drift body, two drift lenses in the outer part of the trough, more or less connected drift patches in the innermost part and small perched sediment patches in a structurally-controlled channel to the north. The seismic (PARASOUND) data show that the main and minor drift bodies are mainly well-stratified, characterized by sub-parallel reflections of moderate to high amplitude and good lateral continuity. The reflectors show an abrupt pinch-out on the northern edge where a distinct moat is present, and a gradual tapering to the south. Internally we identify the base of the drift and four internal horizons, which we correlate throughout the drift. Two units display high amplitude reflectors, marked lensoidal character and restricted lateral extent, suggesting the occurrence of more energetic sedimentary conditions. Facies typical for contourite deposition are found in the sediment cores, with strongly bioturbated sediments and abundant silty/sandy mottles that contain shell fragments. These characteristics, along with the morphological and seismic information, suggest a strong control by a bottom current flowing along the moat on the northern edge of the drift. Though both Atlantic and Arctic waters are known to enter the trough, from the west and the north respectively, brine-enriched shelf water (BSW) produced during winter and flowing westward in the moat, is suggested to be responsible for the genesis of the Kveithola Drift. The formation of BSW is inferred to have started around 13 cal ka BP, the onset of drift deposition, suggesting that conditions leading to atmospheric cooling of the surface waters and/or the presence of coastal polynyas and wind or floating ice shelves have persisted on the western Barents Shelf since that time. The units inferred to have been deposited under more energetic sedimentary conditions (tentatively dated to the Younger Dryas and to 8.9–8.2 cal ka BP) are suggestive of stronger BSW formation. In general, we infer that variations in the bottom current regime were mainly related to BSW formation due to atmospheric changes. They could also have been a response to successive episodes of grounded and sea ice retreat that allowed for a first limited, later open shelf current, which progressively established on the western Barents Sea shelf.

Internal structure of the ice sheet between Kohnen station and Dome Fuji, Antarctica, revealed by airborne radio-echo sounding

AbstractThis study aims to demonstrate that deep ice cores can be synchronized using internal horizons in the ice between the drill sites revealed by airborne radio-echo sounding (RES) over a distance of >1000km, despite significant variations in glaciological parameters, such as accumulation rate between the sites. In 2002/03 a profile between the Kohnen station and Dome Fuji deep ice-core drill sites, Antarctica, was completed using airborne RES. The survey reveals several continuous internal horizons in the RES section over a length of 1217 km. The layers allow direct comparison of the deep ice cores drilled at the two stations. In particular, the counterpart of a visible layer observed in the Kohnen station (EDML) ice core at 1054 m depth has been identified in the Dome Fuji ice core at 575 m depth using internal RES horizons. Thus the two ice cores can be synchronized, i.e. the ice at 1560 m depth (at the bottom of the 2003 EDML drilling) is ∼49ka old according to the Dome Fuji age/depth scale, using the traced internal layers presented in this study.

Regional and temporal variation of accumulation around NorthGRIP derived from ground-penetrating radar

AbstractDuring the summer of 2003, a ground-penetrating radar survey around the North Greenland Icecore Project (NorthGRIP) deep ice-core drilling site (75˚06’N, 42˚20’W; 2957ma.s.l.) was carried out using a shielded 250 MHz radar system. The drill site is located on an ice divide, roughly 300 km north-northwest of the summit of the Greenland ice sheet. More than 430 km of profiles were measured, covering a 10 km by 10 km area, with a grid centered on the drilling location, and eight profiles extending beyond this grid. Seven internal horizons within the upper 120 m of the ice sheet were continuously tracked, containing the last 400 years of accumulation history. Based on the age-depth and density-depth distribution of the deep core, the internal layers have been dated and the regional and temporal distribution of accumulation rate in the vicinity of NorthGRIP has been derived. The distribution of accumulation shows a relatively smoothly increasing trend from east to west from 145 kgm–2a–1 to 200 kg m–2 a -1 over a distance of 50 km across the ice divide. The general trend is overlain by small-scale variations on the order of 2.5 kgm–2a-1 km- 1 , i.e. around 1.5% of the accumulation mean. The temporal variations of the seven periods defined by the seven tracked isochrones are on the order of ± 4% of the mean of the last 400 years, i.e. at NorthGRIP ± 7 kg m–2 a-1. If the regional accumulation pattern has been stable for the last several thousand years during the Holocene, and ice flow has been comparable to today, advective effects along the particle trajectory upstream of NorthGRIP do not have a significant effect on the interpretation of climatically induced changes in accumulation rates derived from the deep ice core over the last 10 kyr.

Narrative in the Feminine: Daphne Marlatt and Nicole Brossard by Susan Knutson

REVIEWS materials gathered here provide guidance, factual information, and a range of critical analyses. Individually, or as a group, they illuminate Pollock’s work and contribute to an understanding of the place of theatre in our culture and history. SH ER R ILL E. G R A C E / U n iversity o f B ritish Colum bia Susan Knutson. Narrative in the Feminine: Daphne Marlatt and Nicole Brossard. Waterloo: Wilfrid Laurier University Press, 2002. 248. $59.95 cloth. Having taught and written on both Daphne Marlatt and Nicole Brossard, I was eager to review this new critical study of their works. I was particularly interested because the author of Nar­ rative in the Feminine is Susan Knutson, a writer whose anal­ yses of poetics I have often found instructive. Her 1995 char­ acterization of Brossard’s motive as “the drive to reach the internal horizons of meaning” (“Reading” 12) is one I return to, particularly as it accommodates a poetic committed to in­ terrogating and romancing the words we have inherited. The word “internal” acknowledges the impossibility of imagining a space wholly external to the symbolic, while “horizon,” a highly invested term in Brossard’s œuvre, signifies the liminal site of productive exploration and renovation. While Knutson and oth­ ers have fostered an interesting critical discussion about how Brossard and Marlatt negotiate a language sedimented with cultural bias, here we have an original study of the ways these poets approach the horizons of the larger grammar of narrative. Knutson brings classical narratology to bear on Marlatt’s long poem How Hug a Stone (1983) and Brossard’s novel Pic­ ture Theory (1982), a tack that leads her inevitably to a con­ comitant critique of this hermeneutic and the introduction of feminist narratology. Both authors are known for the way in which their creative projects blur with and serve as theoretical works, and here Knutson is able to draw from the primary texts themselves as they address traditional narratological assump­ tions. Marlatt, for example, challenges the notion of quest as universal narrative structure; while deploying this heroic model in her account of a trip to England with her son, she overtly 319 ESC 28, 2002 thematizes the failure of such a model to address adequately the intersubjective bond between parent and child and to move out of the gendered schema: male hero/female matrix. A narratological analysis of Knutson’s own book would note the reso­ nance (or to use the narratological term, “mirroring” ) between Marlatt’s simultaneous embrace and refusal of quest narrative and Knutson’s simultaneous adherence to and critique of narratology . Readers unfamiliar with the field of narratology will not be left behind in Knutson’s discussion. She very deftly introduces the key terms and methodologies of the discipline even as she promptly embarks on their application and interrogation. The strategy of committing to a theoretical approach while under­ mining it proves a tricky balancing act. For the most part, Knut­ son’s rigorous narratological analysis proves an excellent vehicle for the elucidation of the complex narrative structures of both Brossard and Marlatt. Since the narrative innovations of their texts ultimately throw into relief the flaws of traditional narra­ tology, however, there are moments when the reader might lose interest in the meticulous structuralist mapping that Knutson has undertaken here. I am grateful, for instance, that Knut­ son has articulated Brossard’s notion of the hologram more thoroughly than any critic to date, but that articulation in­ volves several tabulations of fabula (the chronological sequence of events, or deep structure) that read like statistics. Outside of some of these empirical moments, Narrative in the Feminine is a pleasure to read for its elegant style and intimate knowledge of feminist poetics. The text is bookended by introductory and concluding chap­ ters that address questions surrounding écriture au fém inin: W hat is it? And have these poets, indeed, written in the fem­ inine? Knutson rehearses feminist debates on the topic over several decades and situates specific dialogues and conflicts in France, America, Québec, and English Canada. She also demon­ strates the important contributions Marlatt and Brossard have made to these histories. The confluence of this body...

Subglacial topography and internal structure of central and western Dronning Maud Land, Antarctica, determined from airborne radio echo sounding

During five austral summers, from 1994/1995 until 1998/1999, the Alfred Wegener Institute (AWI) carried out a large airborne radio echo sounding (RES) survey in Dronning Maud Land (DML), Antarctica. These ice thickness measurements are part of the AWI contribution to the pre-site survey for a deep ice core drill site in DML within the European Project for Ice Coring in Antarctica (EPICA). The survey encompasses more than 90,000 km of RES profiles over DML and the adjacent coastal area, covering more than 1 million km 2. The lower boundary of the ice sheet could be determined area-wide. Internal horizons occurring in the upper two-thirds of the ice column can also be traced for several hundred kilometers. This work presents the latest maps of the subglacial topography of the investigated area as well as of an internal horizon.

Solitons and black holes in non-Abelian Einstein–Born–Infeld theory

Recently it was shown that the Born–Infeld modification of the quadratic Yang–Mills action gives rise to classical particle-like solutions in the flat space which have a striking similarity with the Bartnik–McKinnon solutions obtained within the gravity coupled Yang–Mills theory. We show that both families of solutions are continuously related within the framework of the Einstein–Born–Infeld theory via interpolating sequences of parameters. We also investigate an internal structure of the associated black holes and find that the Born–Infeld non-linearity changes drastically the black hole interior typical for the usual quadratic Yang–Mills theory. In the latter case a generic solution exhibits violent metric oscillations near the singularity. In the Born–Infeld case the generic interior solution is smooth, the metric tends to the standard Schwarzschild type singularity, and we did not observe internal horizons. Smoothing of the `violent' EYM singularity may be interpreted as a result of non-gravitational quantum effects.

Vesicles in thick komatiite lava flows, Kambalda, Western Australia

Traditionally, vesicles have been considered to be rare in komatiites, however, field studies at Kambalda, Western Australia, and critical literature examination suggest that vesicle presence and content in komatiites are grossly underestimated. At Kambalda, vesicles are observed in significant amounts (up to 30%) in internal horizons within komatiite lavas. The vesicular horizons are inferred to represent bubbles frozen in place below the upper crust, during multiple episodes of flow through of bubble‐rich lava. We conclude that vesicle and crystal distribution are compatible with many komatiites being emplaced under laminar flow conditions, analogous to models for basalt lava emplacement.

Borehole evidence for a thick layer of basal ice in the central Ronne Ice Shelf

The Ronne Ice Shelf, floating between Berkner Island and the Antarctic peninsula, is the biggest ice shelf in Antarctica. It drains an estimated 1.2 × 106km2 of the Antarctic ice sheet, much of it resting on bedrock below sea level. Consequently, the balance and dynamics of this ice shelf is of importance to Antarctic glaciology, especially with regard to the integration of this part of the cryo-sphere into the global processes that control the climate of the Earth. Extensive radio-echo sounding (RES) by Robin and others revealed reflections in the central part of the Ronne Ice Shelf at the relatively shallow depth of 100–200 m below surface1. The interpretation of these echoes, which varied in strength, was ambiguous, and the possibility of internal reflecting horizons was thoroughly discussed. But after surface elevation measurements by radar altimeter from drifting balloons appeared to fit the presence of thin ice, it was decided to base a thickness map of the Ronne Ice Shelf on these RES echoes1–4. We now present direct observational evidence from boreholes that the total ice thickness is much greater than mapped, and that the shallow RES reflections therefore do come from internal horizons.