Numerical modelling and video analysis of intermediate beach state transitions

Proceedings of the Seventh International Conference on Hydroscience and Engineering, Philadelphia, PA, September 2006. http://hdl.handle.net/1860/732Numerical modelling of beach morphodynamics is generally recognized as a valuable tool for scientists and coastal managers. However, the utility of numerical models is constrained by our ability to establish that the theoretical dynamics match reality. The integrated modules for simulating wave propagation, hydrodynamics and sediment transport in Delft3D, developed by Delft Hydraulics, were applied to simulate observed beach state transitions in response to wave-induced forcing. Initial model bathymetry was derived from hydrographic surveys conducted at Narrowneck beach during the pre- and post-construction phases of the Narrowneck artificial reef (Boak, McGrath and Jackson 2000, Hutt, Black and Mead 1998). The present study addresses the validity of morphological modeling of an exposed beach by comparing the evolution of a numerical model with data observed using remote imaging. Narrowneck beach on the Gold Coast is a micro-tidal, exposed coast subject to a highly variable wave climate. This beach is monitored by an ARGUS Coastal Imaging system generating high temporal frequency geo-referenced estimates of wave dissipation that may be used to infer sub-tidal bar morphology (Alexander and Holman 2004, Aarninkhof and Ruessink 2004, Turner, Dronkers, Roman, Aarninkhof and McGrath 2001). The numerical model was broadly validated, in that, when driven by similar conditions, the surf zone morphological development is consistent with that observed via optical sensing

Uncertainties in the projected patterns of wave-driven longshore sediment transport along a non-straight coastline

This study quantifies the uncertainties in the projected changes in potential longshore sediment transport (LST) rates along a non-straight coastline. Four main sources of uncertainty, including the choice of emission scenarios, Global Circulation Model-driven offshore wave datasets (GCM-Ws), LST models, and their non-linear interactions were addressed through two ensemble modelling frameworks. The first ensemble consisted of the offshore wave forcing conditions without any bias correction (i.e., wave parameters extracted from eight datasets of GCM-Ws for baseline period 1979–2005, and future period 2081–2100 under two emission scenarios), a hybrid wave transformation method, and eight LST models (i.e., four bulk formulae, four process-based models). The differentiating factor of the second ensemble was the application of bias correction to the GCM-Ws, using a hindcast dataset as the reference. All ensemble members were weighted according to their performance to reproduce the reference LST patterns for the baseline period. Additionally, the total uncertainty of the LST projections was decomposed into the main sources and their interactions using the ANOVA method. Finally, the robustness of the LST projections was checked. Comparison of the projected changes in LST rates obtained from two ensembles indicated that the bias correction could relatively reduce the ranges of the uncertainty in the LST projections. On the annual scale, the contribution of emission scenarios, GCM-Ws, LST models and non-linear interactions to the total uncertainty was about 10–20, 35–50, 5–15, and 30–35%, respectively. Overall, the weighted means of the ensembles reported a decrease in net annual mean LST rates (less than 10% under RCP 4.5, a 10–20% under RCP 8.5). However, no robust projected changes in LST rates on annual and seasonal scales were found, questioning any ultimate decision being made using the means of the projected changes

THE BEACHCARE PROGRAM: COMMUNITY PARTICIPATION IN COASTAL DUNE RESTORATION

Coastal management through community involvement has significant advantages over non-participatory approaches as involving the community allows for consideration of multiple interests, resources, and skills that may expand the capacity for action and enhances local stewardship. Participation can help increase project efficiency as it avoids duplication of efforts. Collaborative strategies have been adopted in environmental management in the state of Queensland, Australia. Local governments have been responsible for integrating local instruments with state-level policies in coastal management. This paper analyses a community engagement program for the restoration of coastal environments in Gold Coast. One arm of the program is the BeachCare program, which involves volunteers from local communities in the restoration of coastal dunes. The program involved ten areas of coastal dunes on the Gold Coast. The study analyses the role of community participation in dune restoration by examining the following questions: 1) How do BeachCare volunteers engage with the restoration project? 2) Has community participation in dune restoration been consistent since the program was established in 2005? 3) What types of advantages, if any, did participation bring to the BeachCare program?  Data on participants were analysed and a profile of participating volunteers was established over an eleven-year period (2005-2016). Results indicate that the number of participants increased during the period studied. The number of hours of volunteer work has also increased over the years. BeachCare volunteers have provided a number of reasons why they have chosen to volunteer including benefitting from some kind of social interaction, helping the community, and due to their concern for the environment. Attracting volunteers for environmental projects can enhance the community's ability to organise and create stable collaborative networks that will act more effectively in other situations of responding to disasters and extreme weather events.

THE BEACHCARE PROGRAM: COMMUNITY PARTICIPATION IN COASTAL DUNE RESTORATION

Coastal management through community involvement has significant advantages over non-participatory approaches as involving the community allows for consideration of multiple interests, resources, and skills that may expand the capacity for action and enhances local stewardship. Participation can help increase project efficiency as it avoids duplication of efforts. Collaborative strategies have been adopted in environmental management in the state of Queensland, Australia. Local governments have been responsible for integrating local instruments with state-level policies in coastal management. This paper analyses a community engagement program for the restoration of coastal environments in Gold Coast. One arm of the program is the BeachCare program, which involves volunteers from local communities in the restoration of coastal dunes. The program involved ten areas of coastal dunes on the Gold Coast. The study analyses the role of community participation in dune restoration by examining the following questions: 1) How do BeachCare volunteers engage with the restoration project? 2) Has community participation in dune restoration been consistent since the program was established in 2005? 3) What types of advantages, if any, did participation bring to the BeachCare program?  Data on participants were analysed and a profile of participating volunteers was established over an eleven-year period (2005-2016). Results indicate that the number of participants increased during the period studied. The number of hours of volunteer work has also increased over the years. BeachCare volunteers have provided a number of reasons why they have chosen to volunteer including benefitting from some kind of social interaction, helping the community, and due to their concern for the environment. Attracting volunteers for environmental projects can enhance the community's ability to organise and create stable collaborative networks that will act more effectively in other situations of responding to disasters and extreme weather events.

Dissecting the structural basis of MEIG1 interaction with PACRG

The product of the meiosis-expressed gene 1 (MEIG1) is found in the cell bodies of spermatocytes and recruited to the manchette, a structure unique to elongating spermatids, by Parkin co-regulated gene (PACRG). This complex is essential for targeting cargo to the manchette during sperm flagellum assembly. Here we show that MEIG1 adopts a unique fold that provides a large surface for interacting with other proteins. We mutated 12 exposed and conserved amino acids and show that four of these mutations (W50A, K57E, F66A, Y68A) dramatically reduce binding to PACRG. These four amino acids form a contiguous hydrophobic patch on one end of the protein. Furthermore, each of these four mutations diminishes the ability of MEIG1 to stabilize PACRG when expressed in bacteria. Together these studies establish the unique structure and key interaction surface of MEIG1 and provide a framework to explore how MEIG1 recruits proteins to build the sperm tail

A MEIG1/PACRG complex in the manchette is essential for building the sperm flagella

A key event in the process of spermiogenesis is the formation of the flagella, which enables sperm to reach eggs for fertilization. Yeast two-hybrid studies revealed that meiosis-expressed gene 1 (MEIG1) and Parkin co-regulated gene (PACRG) interact, and that sperm-associated antigen 16, which encodes an axoneme central apparatus protein, is also a binding partner of MEIG1. In spermatocytes of wild-type mice, MEIG1 is expressed in the whole germ cell bodies, but the protein migrates to the manchette, a unique structure at the base of elongating spermatid that directs formation of the flagella. In the elongating spermatids of wild-type mice, PACRG colocalizes with α-tubulin, a marker for the manchette, whereas this localization was not changed in the few remaining elongating spermatids of Meig1-deficient mice. In addition, MEIG1 no longer localizes to the manchette in the remaining elongating spermatids of Pacrg-deficient mice, indicating that PACRG recruits MEIG1 to the manchette. PACRG is not stable in mammalian cells, but can be stabilized by MEIG1 or by inhibition of proteasome function. SPAG16L is present in the spermatocyte cytoplasm of wild-type mice, and in the manchette of elongating spermatids, but in the Meig1 or Pacrg-deficient mice, SPAG16L no longer localizes to the manchette. By contrast, MEIG1 and PACRG are still present in the manchette of Spag16L-deficient mice, indicating that SPAG16L is a downstream partner of these two proteins. Together, our studies demonstrate that MEIG1/PACRG forms a complex in the manchette and that this complex is necessary to transport cargos, such as SPAG16L, to build the sperm flagella

Uncertainties in wave-driven longshore sediment transport projections presented by a dynamic CMIP6-based ensemble

In this study four experiments were conducted to investigate uncertainty in future longshore sediment transport (LST) projections due to: working with continuous time series of CSIRO CMIP6-driven waves (experiment #1) or sliced time series of waves from CSIRO-CMIP6-Ws and CSIRO-CMIP5-Ws (experiment #2); different wave-model-parametrization pairs to generate wave projections (experiment #3); and the inclusion/exclusion of sea level rise (SLR) for wave transformation (experiment #4). For each experiment, a weighted ensemble consisting of offshore wave forcing conditions, a surrogate model for nearshore wave transformation and eight LST models was used. The results of experiment # 1 indicated that the annual LST rates obtained from a continuous time series of waves were influenced by climate variability acting on timescales of 20-30 years. Uncertainty decomposition clearly reveals that for near-future coastal planning, a large part of the uncertainty arises from model selection and natural variability of the system (e.g., on average, 4% scenario, 57% model, and 39% internal variability). For the far future, the total uncertainty consists of 25% scenario, 54% model and 21% internal variability. Experiment #2 indicates that CMIP6 driven wave climatology yield similar outcomes to CMIP5 driven wave climatology in that LST rates decrease along the study area’s coast by less than 10%. The results of experiment #3 indicate that intra- and inter-annual variability of LST rates are influenced by the parameterization schemes of the wave simulations. This can increase the range of uncertainty in the LST projections and at the same time can limit the robustness of the projections. The inclusion of SLR (experiment #4) in wave transformation, under SSP1-2.6 and SSP5-8.5 scenarios, yields only meagre changes in the LST projections, compared to the case no SLR. However, it is noted that future research on SLR influence should include potential changes in nearshore profile shapes

Dose of Prophylactic Platelet Transfusions and Prevention of Hemorrhage

We conducted a trial of prophylactic platelet transfusions to evaluate the effect of platelet dose on bleeding in patients with hypoproliferative thrombocytopenia

Objective beach-state classification from optical sensing of cross-shore dissipation profiles

Remote sensing using terrestrial optical CCD cameras is a useful data-collection method for geophysical measurement in the near-shore zone, where in situ measurement is difficult and time consuming. In particular, optical video sensing of the variability in the visible spectrum from the sea surface due to the near-shore incident wave field is becoming an established method for distal measurement of near-shore sub-tidal morphology. We report on the use of a low-mounted shore-normal camera for gathering data on cross-shore dissipative characteristics of a dynamic, open beach. Data is analysed for the purposes of classifying three of Wright and Shorts’ intermediate classes of morphological beach state, as determined by expert raters. Although these beach states are usually thought of as being distinctive in terms of their longshore bar variability, theory predicts that differences should also be observed in cross-shore dissipative characteristics. Three methods of generating features from statistical features from the archived optical data are described and compared, in terms of their ability to discriminate between the beach states. The best performance was obtained using an pixel intensity percentile representation (which does not assume a Gaussian intensity distribution), which classified 85% of the 284 cases correctly. Class centre moment profiles for each beach state were constructed, and results indicate that cross-shore wave dissipation becomes more disorganized as linear bars devolve into more complex transverse structures