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Metal oxides and carbon are the prime candidates of gas sensor devices. For the inaugural instance, carbonaceous particulate matter was meticulously derived from the branches of Acacia auriculiformis tree indigenous to Sri Lanka to detect vapor and gas. It is worth noting that biomass derived carbon had hitherto remain unexplored in the realm of vapor and gas detection. Carbon films were fabricated via the doctor blade method. The resistivity characteristic of these carbon samples exhibited discernible variations upon exposure to methanol, ethanol, acetone vapors, and ammonia gas. Notably, the gas-sensing properties of sample derived from the central core and the outer shell of Acacia auriculiformis tree branches were independently assessed in these vapors and gas at ambient temperature. Various analytical techniques, including X-ray diffraction (XRD), UVvisible absorption spectroscopy, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM), were judiciously employed to scrutinize the structural attribute, optical band gap, chemical composition and surface morphology of the aforementioned carbon film samples, respectively. XRD analyses unequivocally confirmed the successful formation of carbonaceous films. FTIR spectra conspicuously delineated the presence of oxygen within the carbon films. Importantly, the optical band gap of our carbon films manifested within the range characteristic of organic carbon. Furthermore, the resistance of the carbon films demonstrated a significant reduction upon adsorption of each vapor. It is noteworthy that while gas sensitivities and response times were superior for carbon derived from the central core of the Acacia tree branches, the recovery times were notably expedited for carbon synthesized from the outer shell of these branches. The zenith of gas sensitivity, an impressive 187%, was recorded in response to 1000 ppm of methanol vapor, when employing carbon sourced from the central core of the acacia tree branches. [ABSTRACT FROM AUTHOR]

This study investigated the importance of applying explainable artificial intelligence (XAI) on different machine learning (ML) models developed to predict the strength characteristics of basalt-fiber reinforced concrete (BFRC). Even though ML is widely adopted in strength prediction in concrete, the black-box nature of predictions hinders the interpretation of results. Among several attempts to overcome this limitation by using explainable AI, researchers have employed only a single explanation method. In this study, we used three tree-based ML models (Decision tree, Gradient Boosting tree, and Light Gradient Boosting Machine) to predict the mechanical strength characteristics (compressive strength, flexural strength, and tensile strength) of basal fiber reinforced concrete (BFRC). For the first time, we employed two explanation methods (Shapley additive explanations (SHAP) and local interpretable model-agnostic explanations (LIME)) to provide explanations for all models. These explainable methods reveal the underlying decision-making criteria of complex machine learning models, improving the end user's trust. The comparison highlights that tree-based models obtained good accuracy in predicting strength characteristics yet, their explanations were different either by the magnitude of feature importance or the order of importance. This disagreement pushes towards complicated decision-making based on ML predictions which further stresses (1) extending XAI-based research in concrete strength predictions, and (2) involving domain experts to evaluate XAI results. The study concludes with the development of a "user-friendly computer application" which enables quick strength prediction of basalt fiber reinforced concrete (BFRC). [ABSTRACT FROM AUTHOR]

This study investigated the importance of applying explainable artificial intelligence (XAI) on different machine learning (ML) models developed to predict the strength characteristics of basalt-fiber reinforced concrete (BFRC). Even though ML is widely adopted in strength prediction in concrete, the black-box nature of predictions hinders the interpretation of results. Among several attempts to overcome this limitation by using explainable AI, researchers have employed only a single explanation method. In this study, we used three tree-based ML models (Decision tree, Gradient Boosting tree, and Light Gradient Boosting Machine) to predict the mechanical strength characteristics (compressive strength, flexural strength, and tensile strength) of basal fiber reinforced concrete (BFRC). For the first time, we employed two explanation methods (Shapley additive explanations (SHAP) and local interpretable model-agnostic explanations (LIME)) to provide explanations for all models. These explainable methods reveal the underlying decision-making criteria of complex machine learning models, improving the end user's trust. The comparison highlights that tree-based models obtained good accuracy in predicting strength characteristics yet, their explanations were different either by the magnitude of feature importance or the order of importance. This disagreement pushes towards complicated decision-making based on ML predictions which further stresses (1) extending XAI-based research in concrete strength predictions, and (2) involving domain experts to evaluate XAI results. The study concludes with the development of a "user-friendly computer application" which enables quick strength prediction of basalt fiber reinforced concrete (BFRC). [ABSTRACT FROM AUTHOR]

Jellyfish are marine invertebrates notorious for tentacles that contain venom-bearing nematocytes, which cause painful stings. Climatic changes and human activities have resulted in increasing jellyfish blooms, which have negatively affected functioning of the marine ecosystem as well as human socioeconomic activities. However, some edible jellyfish species have been consumed in Asia for centuries as a food and in medicinal purposes. Moreover, recent research studies have discovered various bioactive properties of jellyfish venoms, including antioxidant, antihypertensive, anticancer, and antimicrobial properties. This review mainly emphasizes the recent studies that have focused on the possible utilization of jellyfish in food and medical applications. [ABSTRACT FROM AUTHOR]

Gelatin, which is widely used in the food industry, is a protein derived from partial denaturation of collagen. The primary sources of industrial gelatin are porcine skin or bovine hide, but their utilization is restricted due to disease outbreaks and on religious grounds. Therefore, gelatin derived from aquatic organisms is attracting widespread interest and can be a good source for harvesting of such proteins. Also, numerous studies have demonstrated bioactive (mainly antioxidant and antihypertensive) properties of enzymatic hydrolysates of aquatic gelatins. This review summarizes sources, significance, functional and bioactive properties of aquatic gelatins as revealed by recent studies. [ABSTRACT FROM AUTHOR]

Compared with clinical mastitis, the subclinical form of mastitis (SCM) is more common and thought to cause more economic losses to the dairy industry. The current study aimed to investigate the prevalence, risk factors of SCM, and effects on reproduction of dairy cows in major milk-producing areas of Sri Lanka. A total of 1,357 cows of selected farms in 3 regions were examined in the study. California Mastitis Test was conducted for individual cows, and a score of 2 or more for any quarter without any clinical symptoms and abnormalities in milk was considered as positive for SCM. Samples from infected animals were collected and subjected to bacteriological analysis. A pretested questionnaire was used to collect data on individual cows and herds. Risk factors associated with SCM were analyzed using binary logistic regression in generalized linear mixed models. The effect of SCM on calving to conception interval and days from calving to artificial insemination were analyzed by survival analysis using Cox's proportional hazards regression and Kaplan-Meier survival function estimates, respectively. A Poisson regression model was run to determine the effect of SCM on number of artificial inseminations per conception. The prevalence of SCM was 57.5, 11.8, and 45.5% in the regions A, B, and C, respectively. The most common pathogen was Staphylococcus aureus , with 87.1, 56.5, and 92.3% in the regions A, B, and C, respectively. Logistic regression analysis showed that parity, farming system, milking area, region, and herd significantly affect the prevalence of SCM. Subclinical mastitis during the pre-breeding period was associated with 14% increase in the chance of having a greater number of artificial inseminations per conception. Likewise, median days from calving to artificial insemination was longer in cows with SCM compared with normal cows (79 and 64 d, respectively). Therefore, SCM affected the inseminated proportion of studied cows. However, SCM was not associated with the calving to conception interval. The results revealed that the cow factors and milk hygiene play a significant role in the prevalence of SCM. [ABSTRACT FROM AUTHOR]

Background: Nowadays people are health-concerned and consume more of functional foods. Thus, this study is focused on developing a drinking yoghurt incorporated with green tea (Camellia sinensis) extract as a functional ingredient. Methods: Green tea extract (GTE) was obtained by brewing 02 g of dried green tea leaves in 100 mL of water at 90°C for 30 minutes. Drinking yoghurts were prepared with standardized sterilized milk incorporated with 0%, 10%, 15%, 20% and 25% (v/v) of GTE. Physio-chemical, microbial and sensory analysis were conducted to evaluate the quality attributes of the developed product. It was stored under refrigerated conditions (4°C) for 15 days. Result: Sensory data showed that 25% green tea extract incorporated drinking yoghurt had the best organoleptic properties. It had the significantly (p<0.05) highest ash and lowest fat contents compared to the control. Significantly (p<0.05) higher pH and lower titratable acidity values were observed in 25% green tea extract incorporated yoghurt compared to the control on 15th day of storage. The microbial analysis did not show the presence of coliform. In conclusion, yoghurt incorporated with 25% (v/v) green tea extract has better organoleptic properties and nutritional value while it can be stored under refrigerated conditions for 15 days without any quality deterioration while producing at affordable price. [ABSTRACT FROM AUTHOR]

As the type species of the genus Channa, the identity of the pelvic-finless snakehead Channa orientalis Bloch is important to channid systematics. Although this name has been attached to a Sri Lankan species for the past 160 years, its vaguely specified type locality, 'India Orientali', has long cast doubt as to its origin. Here, based on a collection across its range in the island and analysis of the cytochrome c oxidase subunit 1 (cox1) barcoding gene, we show that the Sri Lankan pelvic-finless Channa is composed of two geographically discrete lineages separated by an uncorrected pairwise cox1 genetic distance of 6.9–8.1%. The minimum genetic distance between these two lineages and other species of the Gachua group of Channa is 5.1%. Despite their genetic divergence, the two lineages exhibit remarkable morphological stasis: they are indistinguishable from each other in external morphology. We argue that the type locality of C. orientalis is south-western Sri Lanka, to which the species is endemic. Channa orientalis is distinguished from other species of Channa by the absence of pelvic fins, adult coloration in life, dorsal- and anal-fin ray counts, number of vertebrae, and scale counts. [ABSTRACT FROM AUTHOR]

Background: Lesions involving the outer cortical surface of the bone occur quite often among children. Broadly, these include benign cortical, juxtacortical and periarticular lesions, dysplasias affecting the cortical bone, regional and diffuse periosteal pathology and malignant tumours. Some of these lesions are unique to the paediatric population; others are more frequently seen among children than adults - yet others have an adult predilection but can occasionally be seen in children. Methods: A complete list of differential considerations for lesions involving the outer cortical surface of the bone in children is presented. Imaging characteristics on plain film radiography and MR are described in association with multiple examples and illustrations. Conclusion: A pictorial review detailing the imaging features of surface lesions of the bone in children will be a useful aide for both radiologists and their clinical colleagues, and will help them sort their way through the maze of differential diagnoses for these abnormalities. Teaching Points • Surface lesions of bones in children comprise a distinct entity and differ from those in adults. • Imaging plays an important role towards classifying surface lesions of bones in children. • MRI features may be characteristic and aid precise diagnosis, thus guiding further management. [ABSTRACT FROM AUTHOR]

Empirical statistical downscaling methods are becoming increasingly popular in climate change impact assessments that require downscaling multi-global climate model (GCM) projections. Here, empirical statistical downscaling methods are classified based on calibration strategies [bias correction (BC) and change factor (CF)] and statistical transformations (mean based, variance based, quantile mapping, quantile correcting and transfer function methods). Ten combinations of calibration strategies and transformation methods are used to represent a range of empirical statistical downscaling methods. To test the performance of these methods in downscaling daily precipitation and temperature, an inter-model cross-validation is carried out using an ensemble of 16 GCMs from the Coupled Model Intercomparison Project Phase 5 (CMIP5) dataset over the Huai River Basin in China. These downscaling methods are further applied to downscale the climate for the future period to assess the associated uncertainties. The results show that the CF-based methods outperform the BC-based methods in projecting the probability distribution of downscaled daily temperature, while both calibration strategies give comparable results in the case of precipitation. With the CF calibration strategy, simply adding (for temperature) or multiplying (for precipitation) the mean CF is sufficient to represent most of the relative changes projected by GCMs. The use of quantile-based methods appears to be advantageous only at the tails of the distribution. More sophisticated BC methods are needed to remove the biases in the higher-order statistics of the GCM outputs. The two calibration strategies lead to fundamentally different temporal structures and spatial variability of the downscaled climatic variables. The BC-based methods produce larger uncertainty bands of inter-annual variability than the CF-based methods. For downscaled future precipitation, the uncertainty arising from the downscaling methods is comparable to the uncertainty arising from GCMs, while more uncertainty is introduced by calibration strategies than by statistical transformation methods. [ABSTRACT FROM AUTHOR]

Traditional methods for assessing coastal hazards have not typically incorporated a rigorous treatment of uncertainty. Such treatment is necessary to enable risk assessments which are now required by emerging risk based coastal zone management/planning frameworks. While unresolved issues remain, relating to the availability of sufficient data for comprehensive uncertainty assessments, this will hopefully improve in coming decades. Here, we present a modelling framework which integrates geological, engineering and economic approaches for assessing the climate change driven economic risk to coastal developments. The framework incorporates means for combining results from models that focus on the decadal to century time scales at which coasts evolve, and those that focus on the short term and seasonal time scales (storm bite and recovery). This paper demonstrates the functionality of the framework in deriving probabilistic coastal hazard lines and their subsequent use to establish an economically optimal setback line for development at a case study site; the Narrabeen–Collaroy embayment in Sydney, New South Wales. [ABSTRACT FROM AUTHOR]

The order of a phase transition is usually determined by the nature of the symmetry breaking at the phase transition point and the dimension of the model under consideration. For instance, q-state Potts models in two dimensions display a second order, continuous transition for q = 2, 3, 4 and first order for higher q. Tamura et al recently introduced Potts models with 'invisible' states which contribute to the entropy but not the internal energy and noted that adding such invisible states could transmute continuous transitions into first order transitions (Tamura et al 2010 Prog. Theor. Phys. 124 381; 2011 J. Phys: Conf. Ser. 297 012022; 2012 Interface Between Quantum Information and Statistical Physics; Tanaka and Tamura 2011 J. Phys.: Conf. Ser. 320 012025). Thiswas observed both in a Bragg-Williams type mean-field calculation and 2D Monte-Carlo simulations. It was suggested that the invisible state mechanism for transmuting the order of a transition might play a role where transition orders inconsistent with the usual scheme had been observed. In this paper we note that an alternative mean-field approach employing 3-regular random ('thin') graphs also displays this change in the order of the transition as the number of invisible states is varied, although the number of states required to effect the transmutation, 17 invisible states when there are 2 visible states, is much higher than in the Bragg-Williams case. The calculation proceeds by using the equivalence of the Potts model with two visible and r invisible states to the Blume-Emery-Griffiths (BEG) model, so a by-product is the solution of the BEG model on thin random graphs. [ABSTRACT FROM AUTHOR]

A database of milk progesterone profiles consisting 497 lactations in 3 dairy herds from northern and western regions of Japan was used to identify the characteristics and associated risk factors for prolonged luteal phase (PLP) and its effects on subsequent reproductive performance in high-producing Holstein cows. Milk samples were collected twice weekly and progesterone concentrations in whole milk were determined by ELISA. Herds were visited monthly and examined by vaginoscopy and transrectal palpation. Resumption of ovarian cyclicity within 35 d postpartum followed by regular cycles was considered normal. Prolonged luteal phase was defined when progesterone concentrations were ≥5 ng/mL for ≥20 d of duration in any cycle postpartum. Delay of first ovulation to 35 to 60 d (delayed first ovulation type I), >60 d (delayed first ovulation type II), a luteal phase of <14 d except in the first cycle (short luteal phase), and the absence of luteal activity >14 d between 2 cycles (cessation of cyclicity) were the other categories of abnormal ovarian resumptions considered. The overall incidence of PLP in the 3 herds was 11.9% and a significantly higher proportion of PLP was observed in the first cycle postpartum compared with the second and third cycles. Approximately 83% of the PLP were 20 to 28 d in duration, and maximum progesterone concentration was significantly higher when PLP lasted >35 d compared with PLP of 20 to 35 d in duration. Higher parity, commencement of luteal activity ≤28 d postpartum, and postpartum complications significantly increased the occurrence of PLP within 90 d postpartum. Cows with PLP showed reduced conception rate to first artificial insemination (AI) and reduced pregnancy proportions within 100, 150, and 210 d postpartum. Based on survival analysis, PLP was associated with a 56% reduction in relative pregnancy rate and a 36% reduction in AI submission rate. Cows that experienced PLP had a longer interval from calving to first AI (74 d) and from calving to pregnancy (141 d) than cows without PLP (53 and 80 d), respectively. In conclusion, 11.9% of lactations had PLP, of which approximately two-thirds were seen in the first cycle postpartum. Most of the PLP were 20 to 28 d in duration. Higher parity, postpartum complications, and early commencement of luteal activity postpartum increased the risk for PLP. Occurrence of PLP adversely affected fertility by reducing pregnancy proportions and extending calving to conception interval. [ABSTRACT FROM AUTHOR]

A process-based modelling study was carried out by applying a depth-averaged flow module (MIKE 21 HD) and a spectral wave model (MIKE 21 SW) to examine near-shore hydrodynamics of an estuarine beach located in an open estuary: Jimmy's Beach, Port Stephens, Australia. The models were calibrated and validated against recently acquired hydrodynamic data. Model results indicate a significant spatial variability in the near-shore wave parameters along the beach, depending on shoreline orientation; proximity to the mouth of the estuary and sheltering influences of adjacent headlands. Local bathymetry and shoreline orientation play a major role in determining the near-shore ocean wave characteristics at a site along the beach. The shoal previously thought to focus higher wave energy into the erosion spot, in contrast, results in wave energy dissipation. Locally generated waves by the prevailing westerly winds at Jimmy's Beach have low wave energy. Model results also suggest that the near-shore flow patterns are complex due to the presence of tidal eddies and variations in the near-shore wave field along the beach. Currents generated by local wind waves are subordinate to wind stress induced currents. These spatial differences reflect the complex configuration of estuarine shorelines, local topographic controls and variations in exposure to each of the forcing, and may contribute to a high level of beach mobility. [ABSTRACT FROM AUTHOR]

Tidal asymmetry plays a pivotal role in the transport of sediment and morphological change in shallow inlet/estuarine systems, particularly those with extensive tidal flats and channels. This study examined tidal circulation patterns of a shallow and well-mixed estuary on the central coast of New South Wales, Australia. A numerical modelling study was carried out by applying a depth-averaged flow model (MIKE 21 HD). The model was calibrated and successfully validated against recently acquired hydrodynamic data. Model results reveal the presence of a number of eddies within the estuary, which may have substantial influence on net sediment transport when combined with wave effects. Tidal phase duration and magnitude asymmetries indicate that, in contrast to typical flood/ebb dominance, double ebb-dominance is in deep channels and the entrance cross-section, whereas the flood ramp area shows double flood-dominance. The implications of tidal asymmetry on net bed-load sediment transport were inferred from the duration and magnitude asymmetries of the above threshold velocity. The ebb-directed net transport occurs at main tidal channels and may result in further deepening channels, whereas a flood-directed net transport in the flood ramp area may cause an accumulation of sediment on the delta or a landward progradation of the tidal flat. The present-day estuary is characterised as ebb-dominated, tends to flush bed-load sediment seaward more effectively and may represent more stable geometries. [ABSTRACT FROM AUTHOR]

Economic and population growth have led to an unprecedented increase in the value at risk in coastal zones over the last century. To avoid excessive future losses, particularly in the light of projected climate change impacts, coastal zone managers have various instruments at their disposal. These primarily concern land-use planning (establishing buffer zones) and engineering solutions (beach nourishment and coastal protection). In this paper, we focus on risk mitigation through the implementation of buffer zones (setback lines). Foregoing land-use opportunities in coastal regions and protecting coasts is costly, but so is damage caused by inundation and storm erosion. Defining appropriate setback lines for land-use planning purposes is a balancing act. It is, however, unclear what level of protection is facilitated by current approaches for defining setback lines, and whether this is, at least from an economic perspective, sufficient. In this paper, we present an economic model to determine which setback lines would be optimal from an economic perspective. The outcomes of the model provide a useful reference point in the political debate about the acceptability of risk in coastal zones. The main conclusions are: (i) that it is useful to define setback lines on the basis of their exceedance probabilities; (ii) that the exceedance probability of an economically efficient setback line will typically be in the order of magnitude of 1/100 per year; (iii) that it is important to distinguish between situations in which morphological conditions are stationary and non-stationary; and (iv) that long-term uncertainties (eg. due to climate change) influence the exceedance probability of efficient setback lines but only to a limited extent. The economic model stresses the need for a probabilistic approach to beach erosion modelling. The recently-developed Probabilistic Coastal Setback Line was applied at Narrabeen beach, Sydney, Australia, to illustrate how economically optimal setback lines can be derived for specific sites. [ABSTRACT FROM AUTHOR]

Abstract: Submerged breakwaters (SBWs) are becoming a popular option for coastal protection, mainly due to their low aesthetic impact on the natural environment. However, SBWs have rarely been employed for coastal protection in the past and therefore, their efficacy remains largely unknown. The main objective of the present study was to investigate the structural and environmental conditions that govern the mode of shoreline response (i.e shoreline erosion vs shoreline accretion) to SBWs. The relative importance of the key structural and environmental parameters governing the response mode to a single shore parallel SBW is investigated through a combination of theoretical analysis and numerical modelling. Using physical considerations, a theoretical response-function model is derived under several simplifying assumptions including parallel depth contours, linear wave theory, shore normal waves, and no wave–current interaction. Numerical modelling is undertaken with the Mike21 model suite to simulate the depth averaged velocity fields (without morphological updating) due to waves acting on a single shore-parallel SBW located on a schematised beach with parallel depth contours. In total 92 coupled wave–current simulations were undertaken. The results indicate that the mode of shoreline response to the SBW can be expressed in terms of the two non-dimensional parameters h B /H 0 and (s B /h B )3/2(L B /h B )2(A 3/h B )1/2 (variables defined in the text). [ABSTRACT FROM AUTHOR]

Contents Oestrus detection error and conception rates after AI based only on secondary oestrus signs were evaluated in a high yielding, 24-h tie-stalled dairy herd with low fertility, using milk progesterone profiles. Oestrus detection was based on the secondary oestrus signs such as restlessness, swelling, congestion of vulva and clear mucus discharge. Sixty eight AI conducted after observing the secondary oestrus signs in 44 animals were included in the study. Of the 68 AI, 53 (77.9%) were conducted in the follicular phase, and 13 (19.1%) and 2 (2.9%) were carried out in the luteal phase and during pregnancy, respectively. The overall error in oestrus detection based on milk progesterone profiles was 22.1%. The oestrus detection error did not differ significantly among different secondary oestrus signs. None of the AI conducted in the luteal phase resulted in conception, whereas 20.8% of AI conducted in the follicular phase resulted in conception. No significant difference in the conception rates among the groups of cows with different secondary oestrus signs was shown. The high incidence of oestrus detection error in this study might have been caused by the detection of cows in oestrus based only on secondary oestrus signs due to the confinement of animals. In conclusion, there was a high incidence of heat detection error in the 24-h tie-stalled dairy herd and oestrus detection based only on secondary oestrus signs resulted in low conception rate. [ABSTRACT FROM AUTHOR]

Abstract: Due to the unprecedented growth in population and economic development along the coastal zone all over the world, knowledge about future extreme oceanographic events will assist in ensuring human and property safety. This will be a task with increasing significance in the light of projected climate change impacts. A joint estimation of extreme storm events' variates of deep water wave conditions was performed. It can be used for multivariate descriptions of wave climate variates, such as wave height, period, steepness, and storm duration. The storm sequences can be simulated and extrapolated from limited observational data for optimal structure protection strategies and various disaster risk analysis, like erosion or overtopping. The analysis not only shows the effectiveness of the proposed statistical approaches for improving multivariate modelling of the storm parameters but also highlights the most compatible approach for the Dutch wave climate data from 1979 to 2009. We used the Monte-Carlo method and four methods to construct the dependency structures, based on copula functions, physical relationship and extreme value theory. The marginal probabilistic distribution functions of wave climate variables and the joint probability were then obtained. The simulated data group performs a reasonable similarity to the field measurements according to the goodness-of-fit test, and the Gaussian copula model was found to be the best wave climate simulation method for the Dutch coast. [Copyright &y& Elsevier]

ABSTRACT This study presents an analysis of the wind-wave climate on the south-east Australian continental margin and its potential changes under the effects of projected climate change. The wind-wave climate is modelled for three 20 year time-slices (1981-2000, 2031-2051, and 2081-2100) using a dynamical wave modelling approach in which the WaveWatch III spectral wave model, with a nested domain SWAN model, is the region of interest. Surface wind forcing is obtained from an ensemble of three global climate model runs (CSIRO Mk3.5, GFDLcm2.0, and GFDLcm2.1) dynamically downscaled using CSIRO's Cubic conformal atmospheric model (CCAM), under two greenhouse gas emission scenarios (a high emission SRES A2 and low emission SRES B1 scenario). A third level of uncertainty associated with adjusting climate model derived winds for climate and variability bias is found to be the largest source of uncertainty among the limited range of sources considered in the twenty-eight 20 year wave model simulations undertaken herein. The ensemble of wave model runs for the 2081-2100 time-slice project a robust decrease in mean significant wave height along the south-east Australian coast relative to present (1981-2000) conditions. The magnitude of projected change in mean annual significant wave height is less than 0.2 m, with larger values in the north of the region of interest, and is associated with a projected decrease in storm wave energy in the region. An anticlockwise rotation in mean wave direction of approximately 5° is also projected over the same period. Copyright © 2012 Royal Meteorological Society [ABSTRACT FROM AUTHOR]

Abstract: Multiple bar systems often show a cyclic net offshore directed migration with return periods on the order of years. Generally, a bar is generated near the shoreline, grows in height and width, while migrating offshore before finally decaying at the seaward limit of the surf zone. Based on a three-year hindcast of a bar cycle at Noordwijk (Netherlands) and on additional synthetic runs using a wave-averaged cross-shore process model, this study identifies the dominant mechanisms that govern the bar amplitude growth and decay during net interannual offshore migration. The bar amplitude response is particularly sensitive to the water depth above the bar crest, h Xb , and the angle of wave incidence, θ. These variables largely control the amount of waves breaking on the bar and the strength and cross-shore distribution of the associated longshore current. The longshore current has its maximum landward of the bar crest, inducing additional stirring of sediment on the landward bar slope and trough. The enhanced sediment concentration in the trough region shifts the cross-shore transports peak landward of the bar crest forcing bar amplitude growth during offshore migration. For increased h Xb -values wave breaking becomes less frequent, consequently reducing the influence of the longshore current on sediment stirring. Therefore, the resulting dominance of the cross-shore current results in a sediment transport peak at the bar crest causing bar amplitude decay. All four types of bar response (viz. all combinations of onshore/offshore migration and bar amplitude growth/decay) can occur for a single wave height and wave period combination, depending on h Xb and θ. Additional hindcast runs in which the wave direction was assumed time-invariant confirmed that h Xb and θ largely control the transient bar amplitude response. [Copyright &y& Elsevier]

Abstract The Bight of Benin in the Gulf of Guinea, West Africa, forms an embayment between the Volta River delta in the west (Ghana) and the Niger River delta (Nigeria) in the east. The bight coast comprises sandy beaches backed by Holocene beach-ridge barriers. Incident swell waves, beachface gradient and the unidirectional longshore sand transport from west to east are intimately linked, generating a classic example of a strongly wave-dominated drift-aligned coast. The stability of this coast, which hosts several major cities in addition to three large international deepwater ports, has been strongly affected by human activities. We analyzed shoreline mobility and coastal area change over the period 1990–2015. Our results show how the stability of this coast has been strongly affected by the three ports therein, and by natural and human-altered shoreline dynamics related to the Volta River delta and to distributaries at the northwestern flank of the Niger delta. The combination of these factors has impacted alongshore sediment redistribution by segmenting the previously unrestrained longshore transport of sand that prevailed along this open coast. The result is a mixture of natural and artificial sediment cells increasingly dominated by shoreline stretches subject to erosion, endangering parts of the rapidly expanding port cities of Lomé (Togo), Cotonou (Benin) and Lagos (Nigeria), coastal roads and infrastructure, and numerous villages. Post-2000, the entire bight shoreline has undergone a significant decrease in accretion, which is here attributed to an overall diminution of sand supply via the longshore transport system. We attribute this diminution to the progressive depletion of sand-sized bedload supplied to the coast through the main Volta river channel downstream of the Akosombo dam, built between 1961 and 1965. Sand mining to cater for urban construction in Lomé, Cotonou and Lagos has also contributed locally to beach sediment budget depletion. Although alongshore sediment supply from the Volta River has been the dominant source of sand for the stability or progradation of the Bight of Benin coast, potential sand supply from the shoreface, and the future impacts of sea-level rise on this increasingly vulnerable coast are also important. The continued operation of the three ports and of existing river dams, and sea-level rise, will lead to sustained shoreline erosion along the Bight of Benin in the coming decades. Highlights • The wave-dominated Bight of Benin coast is subject to strong west-east longshore sand transport. • The unidirectional longshore sediment transport system has been segmented by several ports. • The resulting mix of natural and artificial sediment cells is associated with increasing shoreline erosion. • This erosion threatens the coastal cities of Lomé, Cotonou and Lagos, and numerous villages. • Lower sand supply from the dammed Volta River, ports, sea-level rise will maintain erosion. [ABSTRACT FROM AUTHOR]

Summary Researchers have long recognized the importance of ecological differences at the species level in structuring natural communities yet until recently have often overlooked the influence of intraspecific trait variation, which can profoundly alter community dynamics [ 1 ]. Human extraction of living resources can reduce intraspecific trait variation by, for example, causing truncation of age and size structure of populations, where numbers of older individuals decline far more with exploitation than younger individuals. Age truncation can negatively affect population and community stability, increasing variability in population and community biomass [ 2–6 ], reducing productivity [ 7–10 ] and life-history diversity in traits such as the spatial and temporal pattern of reproduction and migration [ 4, 11–16 ]. Here, we quantified the extent of age truncation in 63 fished populations across five ocean regions, as measured by how much the proportions of fish in the oldest age groups declined over time. The proportion of individuals in the oldest age classes decreased significantly in 79% to 97% of populations (compared to historical or unfished values, respectively), and the magnitude of decline was greater than 90% in 32% to 41% of populations. The pervasiveness and intensity of age truncation indicates that fishing is likely reducing the stability of many marine communities. Our findings suggest that more emphasis should be given to management measures that reduce the impact of fishing on age truncation, including no-take areas, slot limits that prohibit fishing on all except a narrow range of fish sizes, and rotational harvesting. [ABSTRACT FROM AUTHOR]

Beach nourishment on open ocean beaches not bounded by headlands or other structures suffers from high rates of lateral losses of fill volume as the nourished shoreline equilibrates with its surroundings. Estimates of lateral losses are essential for beach nourishment design, these predictions have been made in the last decade utilizing empirical formulations, one line models or lately, process-based coastal morphology models. Coastal morphology models are, however, complex and computationally intensive and in order to maintain a balance between model complexities, computational effort and processing capacity, schematization of model input (input reduction) is necessary. This paper is divided into two main sections. In the first section techniques of wave input reduction for morphological models are evaluated with focus on open ocean wave-dominated coasts. Subsequently, the optimized morphological model is applied to evaluate coastal engineering interventions aimed at reducing volume losses from the Delray Beach nourishment project. Wave input reduction is defined here as the process of reducing the full wave climate of a given coastal region to a set of representative wave-wind conditions, ‘running’ a model with these representative wave conditions in sequence for a smaller time period ( i.e. a few tide cycles) and multiplying its effect on the morphology by a Morfac value, that is related to the frequency of occurrence of that wave condition in nature, or its weight in the overall wave climate. Five different techniques of wave input reduction were tested. Of all the methods of wave climate schematization tested the methods defined as ‘Energy Flux Method’ and ‘Opti Method’ showed best results in terms of representing accurately the sediment transport patterns of the study area. The tests conducted indicate that a number around 12 representative wave cases was enough to represent an annual wave climate compared to a very detailed wave climate used as benchmark. The optimized model was used to evaluate alternative engineering solutions to reduce volumetric losses from the beach nourishment project. Engineering solutions evaluated included a construction of a breakwater field, backfilling all dredge pits located offshore of the project site, construction of a groin field at the downdrift end of the project, and backfilling the deepest dredge pit. These engineering interventions caused a reduction in beach volume losses within the project limits with varying levels of effect on the downdrift beaches. Reduction of the volume loss from the project site is technically feasible and may be economically feasible pending further economic feasibility evaluation. [ABSTRACT FROM AUTHOR]

Abessolo Ondoa, G.; Almar, R.; Kestenare, E.; Bahini, A.; Houngue, G-H.; Jouanno, J.; Du Penhoat, Y.; Castelle, B.; Melet, A.; Meyssignac, B.; Anthony E.; Laibi, R.; Alory, G., and Ranasinghe R., 2016. Potential of video cameras in assessing event and seasonal coastline behaviour: a case study at Grand Popo, Benin (Gulf of Guinea). In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No.75, pp. 442-446. Coconut Creek (Florida), ISSN 0749-0208. In this study, we explore the potential of a nearshore video system to obtain a long-term estimation of coastal variables (shoreline, beach slope, sea level elevation and wave forcing) at Grand Popo beach, Benin, West Africa, from March 2013 to February 2015. We first present a validation of the video system with field data over a 10-day experiment conducted on Grand Popo beach in 2014. Secondly, 2-years daily and monthly timeseries are extracted and their variability is described as a function of regional forcing and climatic modes. All variables show large monthly variability. The longshore sediment transport estimated locally from video is in agreement with that derived from Era-Interim wave data re-analyses. Results show that the shoreline responds predominantly to tides at the event scale and to waves. Overall, this study suggests that video stations are efficient tools to monitor coastal processes over the long term, in complement with other conventional approaches. Although no clear conclusions can be drawn on inter-annual variability, the results show that it is important to build up extended coastal observation networks to address coastline changes over a wide range of scales. [ABSTRACT FROM AUTHOR]

The short, medium and long-term evolution of the sandy coastline of the Bight of Benin in the Gulf of Guinea, West Africa, has become a major regional focal point due to the rapid socio-economic development that is occurring in the region, including rapid urbanization and a sharp increase in harbor-based trade. Harbors have a significant impact on the present evolution of this coast, notably by affecting longshore sediment transport. However, little is known of the environmental drivers, notably the wave climate, that governs longshore sediment transport and the ensuing pattern of shoreline evolution of this coastal zone. This article aims to address this important knowledge gap by providing a general overview of coastal evolution in the Bight of Benin and the physical processes that control this evolution. Here, the 1979–2012 ERA-Interim hindcast is used to understand the temporal dynamics of longshore sediment transport. Oblique waves (annual average H s =1.36 m, T p =9.6 s, S-SW incidence) drive an eastward drift of approximately 500,000 m 3 /yr. The waves driving this large longshore transport can be separated into two components with distinct origins and behavior: wind waves generated locally in the Gulf of Guinea and swell waves generated in the southern hemisphere sub- (30–35°S), and extra-tropics (45–60°S). The analysis undertaken here shows that the contribution to the gross annual longshore transport from swell wave-driven longshore currents is an order of magnitude larger than the local wind wave-driven longshore currents. Swell waves are dominantly generated by westerlies in the 40–60°S zone and to a lesser extent by trade winds at 30–35°S. The longshore sediment drift decay (−5% over 1979–2012) is found to be linked with a decrease in the intensity of westerly winds associated with their southward shift, in addition to a strengthening of the trade winds, which reduces the eastward sediment transport potential. The equatorial fluctuation of the Inter-Tropical Convergence Zone (ITCZ) is found to explain most of the variability in transport induced by wind waves, while the Southern Annular Mode (SAM), an extra-tropical mode, has a predominant influence on transport induced by swell waves. The ITCZ and SAM have, respectively, a negative and positive trend over the period 1979–2012 that explains the decrease in both wind- and swell-wave-induced transport. For future scenarii, General Circulation Models (GCMs) predict a stabilization of the SAM, and, thus, a non-substantial or weak change in longshore sediment transport can be expected on the coast of the Bight of Benin. [ABSTRACT FROM AUTHOR]

Knowledge about future oceanographic events will assist governments to better manage risk in coastal zones, a crucial task in the light of projected sea level rise, population growth and economic development. In this study, a 31-year data set of deep water wave climate parameters and bathymetry measurements (yearly cross-shore transect surveys) at Noordwijk, the Netherlands, were analysed to jointly estimate storm events variates of deep water wave conditions, and to probabilistically compute dune erosion volume and the resulting dune retreat distance with the simulated wave climate and possible local sea level rise scenarios by 2100. The probabilistic dune retreat models were applied and adjusted to the study site. Based on the outcomes of this application, a modelling technique can be established to propose a framework for probabilistically describing the coastal erosion and recession along the coast protected by dunes. [ABSTRACT FROM AUTHOR]

The number of so-called invisible states which need to be added to the q-state Potts model to transmute its phase transition from continuous to first order has attracted recent attention. In the q = 2 case, a Bragg-Williams (mean-field) approach necessitates four such invisible states while a 3-regular random graph formalism requires seventeen. In both of these cases, the changeover from second- to first-order behaviour induced by the invisible states is identified through the tricritical point of an equivalent Blume-Emery-Griffiths model. Here we investigate the generalized Potts model on a Bethe lattice with z neighbours. We show that, in the q = 2 case, rc(z) = 4z/3(z-1) (z-1/z-2)z invisible states are required to manifest the equivalent Blume-Emery-Griffiths tricriticality. When z = 3, the 3-regular random graph result is recovered, while z → ∞ delivers the Bragg-Williams (mean-field) result. [ABSTRACT FROM AUTHOR]

Li, F., van Gelder, P.H.A.J.M., Callaghan, D.P., Jongejan, R.B., den Hijer, C. and Ranasinghe, R., 2013. Probabilistic modelling of wave climate and predicting dune erosion considering sea level rise Knowledge about future oceanographic events will assist governments to better manage risk in coastal zones, a crucial task in the light of projected sea level rise, population growth and economic development. In this study, a 31-year data set of deep water wave climate parameters and bathymetry measurements (yearly cross-shore transect surveys) at Noordwijk, the Netherlands, were analyzed (1) to jointly estimate storm events variates of deep water wave conditions, and (2) to probabilistically compute dune erosion volume and the resulting coastal retreat distance with the simulated wave climate and plausible local sea level rise scenarios by 2100. The probabilistic coastline retreat models were applied and adjusted to the study site. Based on the outcomes of this application, a modeling technique can be established to propose a framework for probabilistically describing the coastal risk along the Dutch coast. [ABSTRACT FROM AUTHOR]

Abstract: Dunes provide protection for low lying hinterland against flooding due to storms. Due to the dynamic nature of dunes, safety levels provided vary in time. This paper aims to gain insight in how dune building processes govern dune behavior on the yearly to decadal timescale. Dunes grow mainly due to aeolian transport. Most sediment transport formulations suggest that wind velocity is the most important governing parameter for aeolian dune growth. However, in several coastal studies, wind-driven sediment transport has been shown to reach limiting conditions regardless of the wind velocity. Factors that limit the wind-driven sediment transport, such as sediment properties, moisture and beach geometry, can be more important than the wind velocity. The Dutch JARKUS dataset is used to analyze yearly to decadal dune behavior where dune volume changes are taken as a measurable parameter of dune behavior. Measurements of dune volume changes over these timescales mainly show a positive linear trend. Therefore a constant dune growth could be assumed for these specific profiles, which simplifies predictive possibilities. However, the magnitude of the linear dune behavior varies in space (alongshore). It is aimed to find spatial and temporal variations in dune behavior and how these correlate with wind conditions and beach slope. The dune volume changes are found to depend on beach slope which is a transport limiting parameter but no relation between dune behavior and wind forcing is found on the yearly to decadal timescale. Annually averaged erosion volumes as a result of extreme marine events are found to be of similar order as the aeolian growth. In future modeling of decadal dune behavior, we suggest that the variability of transport limiting parameters is of interest rather than time varying forcing conditions such as varying wind speeds and drift potentials. [Copyright &y& Elsevier]

Callaghan, D. P., Nielsen, P. and Ranasinghe, R., 2007. Estimating extreme beach erosion frequency from a Monte Carlo simulation of wave climate. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 88 – 92. Gold Coast, Australia, ISSN 0749.0208 Recent developments in extreme value modelling has been used to develop a robust and defendable framework for determining coastal erosion hazard on sandy coastlines. This framework reproduced well (within factor 2 up to the 15 year return level) the extreme beach erosion volumes obtained from field measurements at Narrabeen Beach, Australia. This encouraging finding was achieved using a simple beach erosion and accretion model following the equilibrium profile approach with exponential response after KRIEBEL and DEAN (1993). The method includes allowances for joint probability between all basic erosion parameters including; wave height, period and direction, event duration, tidal anomalies and event occurrence intensities. This framework includes event grouping where significantly more erosion can occur. This is handled by simulating the event history and estimating the beach accretion between events. [ABSTRACT FROM AUTHOR]

Abstract: Recent developments in extreme values modelling have been used to develop a framework for determining the coastal erosion hazard on sandy coastlines. This framework quantitatively reproduced the extreme beach erosion volumes obtained from field measurements at Narrabeen Beach, Australia. This encouraging finding was achieved using Kriebel and Dean''s [Kriebel, D.L. and Dean, R.G., 1993. Convolution method for time-dependent beach profile response. Journal of Waterway, Port, Coastal and Ocean Engineering, 119(2): 204–226.] simple beach erosion and accretion model. The method includes allowances for joint probability between all basic erosion variates including; wave height, period and direction, event duration, tidal anomalies and event spacing. A new formulation for the dependency between wave height and period has been developed. It includes the physical wave steepness limitation. Event grouping, where significantly more erosion can occur from two closely spaced storms is handled by temporally simulating the synthetic wave climate and the resulting beach erosion and accretion. [Copyright &y& Elsevier]

To guarantee port accessibility, navigation approach channels need to be well maintained. Annual dredging efforts to maintain navigable channels may well exceed tens of millions m 3 of sediment per year, which results in high recurrent costs for port operators. Quantification of expected siltation rates with process-based numerical models helps to effectively design and optimise approach channels. The setup of such models requires several assumptions and parameter settings which introduce uncertainty in model output. However, traditional Monte Carlo methods to quantify that uncertainty in model output are often too resource-intensive with current standard computer resources to be feasibly applied in coastal engineering projects such as approach channel design. Here, we use an alternative multifidelity approach to estimate the probability density function of channel siltation, at lower computational costs compared to direct Monte Carlo simulation. The idea behind this method is to map the output uncertainty of a faster, but inaccurate model to a preferred high-detailed model. The key requirement is that the faster, low-fidelity model and the detailed high-fidelity model are correlated, and that his correlation can be modelled with a probabilistic function. Since linearity of the correlation is not a requirement, the coarse-grid model can be very inaccurate but still serve as an adequate predictor of the high-fidelity model. In this study we did observe a highly nonlinear correlation, which in our case is explained by underestimation of channel siltation near the surf zone by the coarse model. In the presented multifidelity approach we adopted a combination of quasi-random Monte Carlo simulation and a non-parametric Gaussian process transfer function to estimate the uncertainty of total siltation and spatial patterns of siltation in a port approach channel. We argue that the multifidelity approach is conceptually straightforward and found that it can be used to significantly decrease the costs of probabilistic analysis; in our case we found a 85% decrease compared to direct Monte Carlo simulation. An additional advantage is that the approach allows for a trade-off between precision and efficiency by varying the number of high-fidelity model runs. Therefore, we conclude that the multifidelity framework is a potential powerful alternative for cases in which direct Monte Carlo simulation is infeasible or undesirable. • A multifidelity method to quantify high-resolution model uncertainty is presented. • We estimated the probability density functions and spatial siltation patterns of approach channel siltation. • Advantages of the multifidelity method include computational efficiency and a conceptually straightforward approach. • In our case, the computational cost is 85% lower compared to direct Monte Carlo simulation. • The number of high-resolution model runs can be increased to increase estimation precision, or decreased to increase efficiency. [ABSTRACT FROM AUTHOR]

Vila-Concejo, A., Short, A.D., Hughes, M.G. and Ranasinghe, R., 2007. Flood-tide Delta Morphodynamics and Management Implications, Port Stephens, Australia. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 705 – 709. Gold Coast, Australia, ISSN 0749.0208 Port Stephens is a drowned river valley estuary located in SE Australia. Its flood-tide delta is part of the morphological transition between the wave-dominated open coast and the tide-dominated estuarine environment. The sand surface of the flood-tide delta is subject to episodic disturbance by large ocean waves that penetrate into Port Stephens. Moreover, the flood-tide delta is a dynamic feature that responds to variations in the forcing mechanisms. Shoal Bay, Nelson Bay and Jimmy's Beach located on both sides of the entrance have experienced severe erosion for the last 40 years, resulting in expensive shoreline management controls. The evolution of these beaches has been linked to the flood-tide delta morphodynamics. Most of the morphologic features in outer Port Stephens have undergone erosion processes during at least the last 40 years. Yacaaba Head seems to be the only morphologic unit that has undergone sedimentary accretion. Results from numerical models obtained by other authors found eastward directed sediment transport occurring on the eroding beaches. Field measurements and observations show westward sediment transport. Further studies to identify the sediment exchange mechanisms and controls are needed to clarify the morphodynamics of the outer part of Port Stephens. [ABSTRACT FROM AUTHOR]