scholarly journals The possible role of Coriolis forces in structuring large-scale sinuous patterns of submarine channel–levee systems

2013 ◽  
Vol 371 (2004) ◽  
pp. 20120366 ◽  
Author(s):  
Mathew Wells ◽  
Remo Cossu
Keyword(s):  
Large Scale ◽  
Deep Ocean ◽  
Turbidity Currents ◽  
Radius Of Curvature ◽  
Coriolis Parameter ◽  
Coriolis Forces ◽  
Density Interface ◽  
Submarine Channel ◽  
Northern Latitudes ◽  
The Right

Submarine channel–levee systems are among the largest sedimentary structures on the ocean floor. These channels have a sinuous pattern and are the main conduits for turbidity currents to transport sediment to the deep ocean. Recent observations have shown that their sinuosity decreases strongly with latitude, with high-latitude channels being much straighter than similar channels near the Equator. One possible explanation is that Coriolis forces laterally deflect turbidity currents so that at high Northern latitudes both the density interface and the downstream velocity maximum are deflected to the right-hand side of the channel (looking downstream). The shift in the velocity field can change the locations of erosion and deposition and introduce an asymmetry between left- and right-turning bends. The importance of Coriolis forces is defined by two Rossby numbers, Ro W = U / Wf and Ro R = U / Rf , where U is the mean downstream velocity, W is the width of the channel, R is the radius of curvature and f is the Coriolis parameter. In a bending channel, the density interface is flat when Ro R ∼−1, and Coriolis forces start to shift the velocity maximum when | Ro W |<5. We review recent experimental and field observations and describe how Coriolis forces could lead to straighter channels at high latitudes.

A field-scale laboratory to study particulate transport from river source to marine sink: Bute Inlet (Canada)

2021 ◽  
Author(s):  
Sophie Hage ◽  
Sanem Acikalin ◽  
Lewis Bailey ◽  
Matthieu Cartigny ◽  
Michael Clare ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Large Scale ◽  
Sediment Cores ◽  
Past Research ◽  
Transport Processes ◽  
Small Scale ◽  
Turbidity Currents ◽  
Upstream Migration ◽  
Submarine Channel ◽  
The Impact

&lt;p&gt;It is often assumed that particles produced on land (e.g., sediment, pollutants and organic matter) are transported through watersheds to a terminal sediment sink at the seashore. However, terrestrial particles can continue their journey offshore via submarine channels, accumulating in abyssal plains of the oceans. Offshore sediment transport processes are key controls on the burial of organic carbon and the distribution of benthic food, yet they are challenging to study due to the difficulty of capturing usually short duration events within large-scale systems at great ocean depths. Fjords are sufficiently small scale to enable their submarine channel systems to be studied from river source to terminal sink on seafloor fans. Bute Inlet is an up to 650 m deep fjord in British Columbia, Canada. The Homathko and Southgate rivers both feed Bute Inlet with freshwater and terrestrial sediment. A large landslide occurred on 28&lt;sup&gt;th&lt;/sup&gt; November 2020, which caused a Glacial-Lake Outburst Flood (GLOF) which breached a moraine-dam and transported huge volumes of material through the Southgate valley and into Bute Inlet. The impact of this recent event on the submarine system in Bute is, for now, poorly constrained but ongoing work is exploring the impact of this major event on the Inlet. Bute Inlet is one of the most studied fjords worldwide, with a range of offshore campaigns that have been conducted during the last seventy years, providing an unprecedented background dataset and thus opportunity to explore what impact a large magnitude, low frequency terrestrial event had on the submarine system. This presentation will provide an overview of the past research conducted on the Bute submarine channel system, under more usual river discharge conditions and compare this background context to the recent GLOF event.&lt;/p&gt;&lt;p&gt;Previous studies have revealed that the floor of the Inlet is characterized by a 40 km long submarine channel formed by submarine avalanches of sediment (turbidity currents) that can be up to 30 m thick and reach velocities of up to 6.5 m/s. Based on time-lapse bathymetric mapping over 10 years, the evolution of this channel is known to be controlled by the fast (100 to 450 m/yr) upstream migration of 5 to 30 m high steps (called knickpoints) in the channel floor. Sediment cores reveal that the channel floor and proximal lobe are dominated by sand and up to 3 % of total organic carbon in the form of young woody debris. Research in Bute Inlet has thus allowed submarine flow processes, seafloor morphology and deposits to be linked in unprecedented detail. Using those past results as a baseline, new data collected after the GLOF will be crucial for testing the impact of high-magnitude catastrophic events on a marine system and the ultimate sink for the terrestrial material. Understanding what impact the GLOF had on the usual seafloor processes has direct implications for the preservation of benthic communities living in the fjord and for the global carbon cycle.&lt;/p&gt;

Why Has There Been No People’s Power Rebellion in North Korea?

2018 ◽  
pp. 1-34
Author(s):  
Andrew Jackson
Keyword(s):  
Rural Areas ◽  
North Korea ◽  
Large Scale ◽  
Political Elite ◽  
Information Control ◽  
Al Jazeera ◽  
The North ◽  
New Information ◽  
Effective System ◽  
The Right

One scenario put forward by researchers, political commentators and journalists for the collapse of North Korea has been a People’s Power (or popular) rebellion. This paper analyses why no popular rebellion has occurred in the DPRK under Kim Jong Un. It challenges the assumption that popular rebellion would happen because of widespread anger caused by a greater awareness of superior economic conditions outside the DPRK. Using Jack Goldstone’s theoretical expla-nations for the outbreak of popular rebellion, and comparisons with the 1989 Romanian and 2010–11 Tunisian transitions, this paper argues that marketi-zation has led to a loosening of state ideological control and to an influx of infor-mation about conditions in the outside world. However, unlike the Tunisian transitions—in which a new information context shaped by social media, the Al-Jazeera network and an experience of protest helped create a sense of pan-Arab solidarity amongst Tunisians resisting their government—there has been no similar ideology unifying North Koreans against their regime. There is evidence of discontent in market unrest in the DPRK, although protests between 2011 and the present have mostly been in defense of the right of people to support themselves through private trade. North Koreans believe this right has been guaranteed, or at least tacitly condoned, by the Kim Jong Un government. There has not been any large-scale explosion of popular anger because the state has not attempted to crush market activities outright under Kim Jong Un. There are other reasons why no popular rebellion has occurred in the North. Unlike Tunisia, the DPRK lacks a dissident political elite capable of leading an opposition movement, and unlike Romania, the DPRK authorities have shown some flexibility in their anti-dissent strategies, taking a more tolerant approach to protests against economic issues. Reduced levels of violence during periods of unrest and an effective system of information control may have helped restrict the expansion of unrest beyond rural areas.

White Backlash

2015 ◽  
Author(s):  
Marisa Abrajano ◽  
Zoltan L. Hajnal
Keyword(s):  
Ethnic Diversity ◽  
Republican Party ◽  
Large Scale ◽  
White Americans ◽  
Political Beliefs ◽  
White Backlash ◽  
Political Spectrum ◽  
Racial Divide ◽  
The Right ◽  
Political Backlash

This book provides an authoritative assessment of how immigration is reshaping American politics. Using an array of data and analysis, it shows that fears about immigration fundamentally influence white Americans' core political identities, policy preferences, and electoral choices, and that these concerns are at the heart of a large-scale defection of whites from the Democratic to the Republican Party. The book demonstrates that this political backlash has disquieting implications for the future of race relations in America. White Americans' concerns about Latinos and immigration have led to support for policies that are less generous and more punitive and that conflict with the preferences of much of the immigrant population. America's growing racial and ethnic diversity is leading to a greater racial divide in politics. As whites move to the right of the political spectrum, racial and ethnic minorities generally support the left. Racial divisions in partisanship and voting, as the book indicates, now outweigh divisions by class, age, gender, and other demographic measures. The book raises critical questions and concerns about how political beliefs and future elections will change the fate of America's immigrants and minorities, and their relationship with the rest of the nation.

Evaluation of Ovaries in Patients with Polycystic Ovary Syndrome using Shear Wave Elastography

2020 ◽  
Vol 16 (5) ◽  
pp. 578-583
Author(s):  
Aysegul Altunkeser ◽  
Zeynep Ozturk Inal ◽  
Nahide Baran
Keyword(s):  
Shear Wave ◽  
Large Scale ◽  
Polycystic Ovary ◽  
Shear Wave Elastography ◽  
Left Ovary ◽  
Control Group ◽  
Tissue Elasticity ◽  
Group I ◽  
Pcos Group ◽  
The Right

Background: Shear wave electrography (SWE) is a novel non-invasive imaging technique which demonstrate tissue elasticity. Recent research evaluating the elasticity properties of normal and pathological tissues emphasize the diagnostic importance of this technique. Aims: Polycystic ovarian syndrome (PCOS), which is characterized by menstrual irregularity, hyperandrogenism, and polycystic overgrowth, may cause infertility. The aim of this study was to evaluate the elasticity of ovaries in patients with PCOS using SWE. Methods: 66 patients diagnosed with PCOS according to the Rotterdam criteria (PCOS = group I) and 72 patients with non-PCOS (Control = group II), were included in the study. Demographic and clinical characteristics of the participants were recorded. Ovarian elasticity was assessed in all patients with SWE, and speed values were obtained from the ovaries. The elasticity of the ovaries was compared between the two groups. Results: While there were statistically significant differences between the groups in body mass index (BMI), right and left ovarian volumes, luteinizing hormone and testosterone levels (p<0.05), no significant differences were found between groups I and II in the velocity (for the right ovary 3.89±1.81 vs. 2.93±0.72, p=0.301; for the left ovary 2.88±0.65 vs. 2.95±0.80, p=0.577) and elastography (for the right ovary 36.62±17.78 vs. 36.79±14.32, p=0.3952; for the left ovary 36.56±14.15 vs. 36.26±15.10, p=0.903) values, respectively. Conclusion: We could not obtain different velocity and elastography values from the ovaries of the patients with PCOS using SWE. Therefore, further large-scale studies are needed to elucidate this issue.

Introduction: Configuring the Green New Deal

2021 ◽  
pp. 103530462110176
Author(s):  
Anna Sturman ◽  
Natasha Heenan
Keyword(s):  
Land Use ◽  
Indigenous Peoples ◽  
New Deal ◽  
Large Scale ◽  
Political Strategy ◽  
Right Wing ◽  
Jel Codes ◽  
Economic Stagnation ◽  
Political Project ◽  
The Right

We introduce a themed collection of articles on approaches to configuring a Green New Deal as a response to the current capitalist crisis marked by ecological breakdown, economic stagnation and growing inequality. The Green New Deal is a contested political project, with pro-market, right-wing nationalist, Keynesian, democratic socialist and ecosocialist variants. Critiques of the Green New Deal include pragmatic queries as the feasibility of implementation, and theoretical challenges from the right regarding reliance on state forms and from the left regarding efforts to ameliorate capitalism. They also include concerns about technocratic bias and complaints about lack of meaningful consultation with Indigenous peoples on proposals for large-scale shifts in land use. Debates over the ideological orientation, political strategy and implementation of the Green New Deal must now account for the economic and employment impacts of COVID. JEL Codes: Q43, Q54, Q56, Q58

scholarly journals Perinatal mental health around the world: priorities for research and service development in Africa

2020 ◽  
Vol 17 (3) ◽  
pp. 56-59 ◽  
Author(s):  
Mwawi Ng'oma ◽  
Tesera Bitew ◽  
Malinda Kaiyo-Utete ◽  
Charlotte Hanlon ◽  
Simone Honikman ◽  
...  
Keyword(s):  
Mental Health ◽  
Mental Disorders ◽  
Partner Violence ◽  
Large Scale ◽  
Infant Health ◽  
Common Mental Disorders ◽  
Maternal Mental Health ◽  
Service Development ◽  
Middle Income ◽  
The Right

Africa is a diverse and changing continent with a rapidly growing population, and the mental health of mothers is a key health priority. Recent studies have shown that: perinatal common mental disorders (depression and anxiety) are at least as prevalent in Africa as in high-income and other low- and middle-income regions; key risk factors include intimate partner violence, food insecurity and physical illness; and poor maternal mental health is associated with impairment of infant health and development. Psychological interventions can be integrated into routine maternal and child healthcare in the African context, although the optimal model and intensity of intervention remain unclear and are likely to vary across settings. Future priorities include: extension of research to include neglected psychiatric conditions; large-scale mixed-method studies of the causes and consequences of perinatal common mental disorders; scaling up of locally appropriate evidence-based interventions, including prevention; and advocacy for the right of all women in Africa to safe holistic maternity care.

An experimental study of strongly nonlinear waves in a rotating system

1987 ◽  
Vol 177 ◽  
pp. 381-394 ◽  
Author(s):  
Dominique P. Renouard ◽  
Gabriel Chabert D'Hières ◽  
Xuizhang Zhang
Keyword(s):  
Equilibrium Shape ◽  
Scaling Law ◽  
Maximum Amplitude ◽  
Rotating Platform ◽  
Coriolis Parameter ◽  
Rotating System ◽  
Height Variation ◽  
Experimental Conditions ◽  
Strongly Nonlinear ◽  
The Right

The influence of rotation upon internal solitary waves is studied in a (10 m × 2 m × 0.6 m) channel located on the large rotating platform at Grenoble University. We observe an intumescence which moves along the right-hand side of the channel with respect to its direction of propagation. Along the side, once the intumescence reaches its equilibrium shape, the height variation of the interface with time is correctly described by the sech2 function, and the characteristic KdV scaling law linking the maximum amplitude and the wavelength along the side is fulfilled. The intumescence is a stable phenomenon which moves as a whole without deformation apart from the viscous damping. For identical experimental conditions, the amplitude of the intumescence along the side increases with increasing Coriolis parameter, and at a given period of rotation of the platform, the celerity along the side increases with increasing amplitude. But for identical conditions, we found that the celerity along the side is equal to the celerity that the wave would have for such conditions without rotation. The amplitude of the intumescence in a plane perpendicular to the wall decreases exponentially with increasing distance from the side, but the crest of the wave is curved backward.

Buyer-assisted lean intervention in supplier firms: a supplier development approach

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Imranul Hoque
Keyword(s):  
Financial Incentives ◽  
Large Scale ◽  
Qualitative Data ◽  
Research Approach ◽  
Capability Development ◽  
Content Type ◽  
Production Capability ◽  
Lean Tools ◽  
The Right ◽  
The Impact

PurposeThis study aims to investigate how buyer-assisted lean intervention in garment supplier factories affects garment suppliers' productivity and production capability development.Design/methodology/approachEmploying a qualitative research approach and a lean intervention design, a multiple case study method was adopted for this study. Quantitative data on productivity performance and qualitative data on production capability development were collected from a Danish buyer and their four corresponding garment suppliers. Collected data were analysed using standard lean measurement tools and qualitative data analysis techniques.FindingsThis study demonstrates that buyer-assisted lean intervention is a useful strategy for garment suppliers to enhance their productivity and production capability. However, suppliers need to select the right lean tools, ensure seriousness and commitment to lean initiatives, substantial involvement of top management and workers, arrange formal and informal training, provide performance-based financial/non-financial incentives and nurture a learning culture to facilitate suppliers' production capability development.Research limitations/implicationsThis study implemented few lean tools in a single sewing line in four supplier factories for a short intervention duration. Thus, there is a scope for future studies to investigate the impact of the lean intervention on a large scale.Practical implicationsThe findings of this study might bring new insights to the management of buyer and supplier firms concerning how buyers could involve in suppliers' lean intervention initiatives and what suppliers need to ensure to develop production capability.Originality/valueFor the first time, this study engaged a buyer in suppliers' lean intervention initiatives to improve productivity and production capability in the garment industry of a developing country.

Microsurgically generated discontinuities provoke heritable changes in cellular handedness of a ciliate, Stylonychia mytilus

Development ◽  
1991 ◽  
Vol 111 (2) ◽  
pp. 337-356
Author(s):  
X.B. Shi ◽  
Z.I. Qiu ◽  
W. He ◽  
J. Frankel
Keyword(s):  
Large Scale ◽  
Mirror Image ◽  
The Other ◽  
Left Edge ◽  
Left Handed ◽  
Specific Manner ◽  
The Right ◽  
Anteroposterior Polarity ◽  
Posterior Anterior ◽  
Stylonychia Mytilus

Stylonychia mytilus is a dorsoventrally flattened ciliate with compound ciliary structures arranged in a specific manner on the cell surface. In mirror-image (MI) doublets of this ciliate, two nearly complete sets of ciliary structures are arrayed side-by-side, one in a normal or ‘right-handed’ (RH) arrangement, the other in a reversed or ‘left-handed’ (LH) arrangement. MI-doublets exist in two forms, one with the RH component on the right, the LH component on the left, and feeding structures near the center (‘buccal-adjoining MI-doublet’); the other with the RH component on the left, the LH component on the right, and feeding structures on the lateral edges (‘buccal-opposing MI-doublet’). We describe an operation that can generate either type of MI-doublet. This operation interchanges large anterior and posterior regions of the cell, transposing the original posterior region anteriorly (P—A) and the original anterior region posteriorly (A—P), while retaining the original anteroposterior polarity of each region. Two sets of new ciliary structures then are formed in mirror-image arrangement, with the set in the P—A region oriented normally and the set in the A—P region undergoing a reversal of polarity along its anteroposterior axis. This sometimes creates end-to-end MI forms, but more commonly produces side-by-side MI-doublets through a folding together of the P—A and A—P regions. This folding occurs because one lateral edge of the cell had been removed during the operation; if the left edge was removed, the complex folds to the left and forms a buccal-adjoining MI-doublet, whereas if the right edge was removed, the complex folds to the right and forms a buccal-opposing MI-doublet. Both types can reorganize and later divide true-to-type, although the ‘buccal-opposing’ type is by far the more stable of the two. The generation of mirror-image forms is dependent on the prior abnormal juxtaposition of regions from opposite ends of the cell, and involves a coordinated respecification of large-scale organization. We interpret this response to be a consequence of intercalation of missing intervening positional values in the zone of posterior-anterior abutment.

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