Scour hole development in river beds with mixed sand-clay-peat stratigraphy

River deltas are often characterized by a heterogeneous subsoil stratigraphy, composed of layers of sand, clay and peat. This has important consequences for the riverbed morphology and in particular the formation of scour holes. When the riverbed is composed of poorly erodible clay or peat, erosion processes are retarded. However, when thinner parts of clay or peat layers erode; underlying sand patches are incised and large scour holes may develop within in a short amount of time. The unpredictability and fast development makes these scour holes difficult to manage while stability of dikes and infrastructure may be at stake. In this paper we study the scour hole formation and development in heterogeneous subsoil. The Rhine-Meuse estuary forms the ideal system for this analysis as it has been intensively measured and contains about 100 scour holes. Based on nearly 60 years of river bed topography data and data on the subsurface lithography and hydrodynamics, we present a system analysis of scour hole formation in heterogeneous subsoil stratigraphy. In addition the detailed growth of a recently formed scour hole is studied and compared to scale model tests

Charity Fundraising Project:A Team-Based Project for Developing Problem-Structuring Skills

Increasingly, graduates of business schools will face business and organizational situations with a high degree of complexity and ambiguity. In this context, teaching and learning strategies need to develop students’ abilities in problem structuring and complex problem solving. This article describes a team-based project set to teams of four or five students, who are required to design and deliver a fundraising event for their chosen charity. The goal of the fundraising activity is to raise as much money as they can in a 24-hour period. Using ideas from problem-based learning (PBL), students learn frameworks and tools to increase their confidence in these situations. This article describes this activity and will be of interest to teachers of final-year undergraduate and master’s programs looking for a fun and inspiring activity to do with students.Increasingly, graduates of business schools will face business and organizational situations with a high degree of complexity and ambiguity. In this context, teaching and learning strategies need to develop students’ abilities in problem structuring and complex problem solving. This article describes a team-based project set to teams of four or five students, who are required to design and deliver a fundraising event for their chosen charity. The goal of the fundraising activity is to raise as much money as they can in a 24-hour period. Using ideas from problem-based learning (PBL), students learn frameworks and tools to increase their confidence in these situations. This article describes this activity and will be of interest to teachers of final-year undergraduate and master’s programs looking for a fun and inspiring activity to do with students

Distortion Product Otoacoustic Emissions Evoked by Tone Complexes

Distortion product otoacoustic emissions (DPOAEs) are traditionally evoked by two-tone stimuli. In this study, emission data from Mongolian gerbils are reported that were obtained with stimuli consisting of six to 10 tones. The stimuli were constructed by replacing one of the tones of a tone pair by a narrowband multitone complex. This produced rich spectra of the ear canal sound pressure in which many of the third-order DPOAEs originated from the interaction of triplets of stimulus components. A careful choice of the stimulus frequencies ensured that none of these DPOAE components coincided. Three groups of DPOAEs are reported, two of which are closely related to DPOAEs evoked by tone pairs. The third group has no two-tone equivalent and only arises when using a multitone stimulus. We analyzed the relation between multitone-evoked DPOAEs and DPOAEs evoked by tone pairs, and explored the new degrees of freedom offered by the multitone paradigm

Selective serotonin reuptake inhibitor antidepressant use in first trimester pregnancy and risk of specific congenital anomalies: A European register-based study

Evidence of an association between early pregnancy exposure to selective serotonin reuptake inhibitors (SSRI) and congenital heart defects (CHD) has contributed to recommendations to weigh benefits and risks carefully. The objective of this study was to determine the specificity of association between first trimester exposure to SSRIs and specific CHD and other congenital anomalies (CA) associated with SSRI exposure in the literature (signals). A population-based case-malformed control study was conducted in 12 EUROCAT CA registries covering 2.1 million births 1995-2009 including livebirths, fetal deaths from 20 weeks gestation and terminations of pregnancy for fetal anomaly. Babies/fetuses with specific CHD (n = 12,876) and non-CHD signal CA (n = 13,024), were compared with malformed controls whose diagnosed CA have not been associated with SSRI in the literature (n = 17,083). SSRI exposure in first trimester pregnancy was associated with CHD overall (OR adjusted for registry 1.41, 95% CI 1.07-1.86, fluoxetine adjOR 1.43 95% CI 0.85-2.40, paroxetine adjOR 1.53, 95% CI 0.91-2.58) and with severe CHD (adjOR 1.56, 95% CI 1.02-2.39), particularly Tetralogy of Fallot (adjOR 3.16, 95% CI 1.52-6.58) and Ebstein's anomaly (adjOR 8.23, 95% CI 2.92-23.16). Significant associations with SSRI exposure were also found for ano-rectal atresia/stenosis (adjOR 2.46, 95% CI 1.06-5.68), gastroschisis (adjOR 2.42, 95% CI 1.10-5.29), renal dysplasia (adjOR 3.01, 95% CI 1.61-5.61), and clubfoot (adjOR 2.41, 95% CI 1.59-3.65). These data support a teratogenic effect of SSRIs specific to certain anomalies, but cannot exclude confounding by indication or associated factors

Developing Student Engagement in China Through Collaborative Action Research

As its market and society open up, China has transformed itself from a closed agrarian socialist economy to an urban state and an economic force. This has released accumulated tourism demand, led to the development of a diversified industry, and the spread of university and vocational courses in this field. However, the industry faces challenges to recruit and retain staff, with tourism education in higher education blamed for the shortfall in numbers and quality of candidates with suitable purpose, knowledge, and passion to serve. This chapter provides a background to the development of and problems facing tourism education in China, and suggests how to support student engagement and hence the future workforce