Wave attenuation is a recognized function of sea grass ecosystems which is believed to depend on plant characteristics. This paper presents field data on wave attenuance collected over a 13 month ...period in a Zostera noltii meadow. The meadow showed a strong seasonality with high shoot densities in summer (approximately 4,600 shoots/m2) and low densities in winter (approximately 600 shoots/m2). Wave heights and flow velocities were measured along a transect at regular intervals during which the site was exposed to wind waves and boat wakes that differ in wave period and steepness. This difference was used to investigate whether wave attenuation by sea grass changes with hydrodynamic conditions. A seasonal change in wave attenuation was observed from the data. Results suggest that a minimum shoot density is necessary to initiate wave attenuation by sea grass. Additionally, a dependence of wave attenuation on hydrodynamics was found. Results suggest that the threshold shoot density varies with wave period and a change in energy dissipation toward the shore was observed once this threshold was exceeded. An attempt was made to quantify the bed roughness of the meadow; the applicability of this roughness value in swaying vegetation is discussed. Finally, the drag coefficient for the meadow was computed: A relationship between wave attenuance and vegetation Reynolds number was found which allows comparing the wave attenuating effect of Zostera noltii to other plant species.
Key Points
Zostera noltii attenuates waves
Wave attenuation depends on plant characteristics and hydrodynamics
Boat wakes and natural waves get attenuated differently by sea grass
STAMPEDE has previously reported that the use of upfront docetaxel improved overall survival (OS) for metastatic hormone naïve prostate cancer patients starting long-term androgen deprivation ...therapy. We report on long-term outcomes stratified by metastatic burden for M1 patients.
We randomly allocated patients in 2 : 1 ratio to standard-of-care (SOC; control group) or SOC + docetaxel. Metastatic disease burden was categorised using retrospectively-collected baseline staging scans where available. Analysis used Cox regression models, adjusted for stratification factors, with emphasis on restricted mean survival time where hazards were non-proportional.
Between 05 October 2005 and 31 March 2013, 1086 M1 patients were randomised to receive SOC (n = 724) or SOC + docetaxel (n = 362). Metastatic burden was assessable for 830/1086 (76%) patients; 362 (44%) had low and 468 (56%) high metastatic burden. Median follow-up was 78.2 months. There were 494 deaths on SOC (41% more than the previous report). There was good evidence of benefit of docetaxel over SOC on OS (HR = 0.81, 95% CI 0.69–0.95, P = 0.009) with no evidence of heterogeneity of docetaxel effect between metastatic burden sub-groups (interaction P = 0.827). Analysis of other outcomes found evidence of benefit for docetaxel over SOC in failure-free survival (HR = 0.66, 95% CI 0.57–0.76, P < 0.001) and progression-free survival (HR = 0.69, 95% CI 0.59–0.81, P < 0.001) with no evidence of heterogeneity of docetaxel effect between metastatic burden sub-groups (interaction P > 0.5 in each case). There was no evidence that docetaxel resulted in late toxicity compared with SOC: after 1 year, G3-5 toxicity was reported for 28% SOC and 27% docetaxel (in patients still on follow-up at 1 year without prior progression).
The clinically significant benefit in survival for upfront docetaxel persists at longer follow-up, with no evidence that benefit differed by metastatic burden. We advocate that upfront docetaxel is considered for metastatic hormone naïve prostate cancer patients regardless of metastatic burden.
Kassem, H.; Amos, C.L., and Thompson, C.E.L., 2023. Sea surface temperature trends in the coastal zone of southern England. Journal of Coastal Research, 39(1), 18–31. Charlotte (North Carolina), ISSN ...0749-0208. Sea surface temperature (SST) trends along the south coast of England (northern English Channel) were examined based on data from systematic buoy measurements deployed by the National Network of Regional Coastal Monitoring Programmes of England (NNRCMP) since 2003. These data were supplemented with: (1) long-term, coastal SST measurements by the Centre for Environment, Fisheries and Aquaculture Science (CEFAS); (2) global data sets compiled by the Hadley Centre since 1900, and (3) satellite-derived observations from Moderate Resolution Imaging Spectroradiometer (MODIS) (Aqua) since 2002. These data sets were used to evaluate de-seasoned nearshore trends in SST along the south coast of England and examine links to regional ocean-atmosphere teleconnections. The analyses of long-term, CEFAS data support the proposal that prior to the mid-1980s there were no de-seasoned trends in SST and conditions from year to year were relatively stable. Subsequently, interannual fluctuations appear to have increased, associated with a period of warming between 1985 and 2003 (0.28 °C/decade). Post 2003, interannual fluctuations in SST monitored by the NNRCMP buoys continued, and the warming trend appears to be greater (0.42 °C/decade). This trend in SST is greatest in the nearshore and decreases with distance offshore. The warming in SST also varied greatly from month to month. The greatest warming took place from December to March, whilst the least heating (and sometimes cooling) occurred between September and November. Analysis of Hadley (HadSST1.1) and MODIS data sets substantiated these trends. The greatest warming (post 2003) was found west of Portland Bill (up to 0.76 °C/decade) and decreased towards the Strait of Dover. Despite this west-to-east trend, all 12 NNRCMP stations between Penzance and Folkestone showed remarkably similar results, suggesting regional and global sources of heat rather than local sources. This is corroborated through wavelet coherence analysis linking SST anomalies to regional/global ocean-atmosphere teleconnection indices at seasonal scales.
Accurate wave height prediction along the shore plays an important role in coastal protection and management. To account for the effect of submerged vegetation in wave-attenuation models, it is ...important to understand how the interaction between vegetation characteristics and hydrodynamic forcing affects wave attenuation. To determine the effect of vegetation characteristics, we used seagrass mimics that varied in (1) blade stiffness, (2) shoot density and (3) leaf length; to investigate the effect of hydrodynamic forcing, we studied wave attenuation in the absence and presence of a tidal current. Results show that wave attenuation is positively correlated with blade stiffness and for a given wave in shallow water, attenuation is dependent on a combination of shoot density and leaf length, which can be described by the leaf area index. The presence of a tidal current strongly reduced the wave-attenuating capacity of seagrass mimics, and this reduction was most pronounced at high shoot densities. Thus, most studies that have been carried out under waves only will structurally overestimate wave attenuation for tidal environments, emphasising that tidal currents need to be taken into account in future studies on wave attenuation by vegetation.
THOC6 is a part of the THO complex, which is involved in coordinating mRNA processing with export. The THO complex interacts with additional components to form the larger TREX complex (transcription ...export complex). Previously, a homozygous missense mutation in THOC6 in the Hutterite population was reported in association with syndromic intellectual disability. Using exome sequencing, we identified three unrelated patients with bi‐allelic mutations in THOC6 associated with intellectual disability and additional clinical features. Two of the patients were compound heterozygous for a stop and a missense mutation, and the third was homozygous for a missense mutation; the missense mutations were predicted to be pathogenic by in silico analysis and modeling. Clinical features of the three newly identified patients and those previously reported are reviewed; intellectual disability is moderate to severe, and malformations are variable including renal and heart defects, cleft palate, microcephaly, and corpus callosum dysgenesis. Facial features are variable and include tall forehead, short upslanting palpebral fissures +/− deep set eyes, and a long nose with overhanging columella. These subtle facial features render the diagnosis difficult to make in isolation with certainty. Our results expand the mutational and clinical spectrum of this rare disease, confirm that THOC6 is an intellectual disability causing gene, while providing insight into the importance of the THO complex in neurodevelopment.
Kassem, H.; Sutherland, T.F., and Amos, C.L., 2021. Hydrodynamic controls on the particle size of resuspended sediment from sandy and muddy substrates in British Columbia, Canada. Journal of Coastal ...Research, 37(4), 691–707. Coconut Creek (Florida), ISSN 0749-0208. A benthic annular flume, Sea Carousel, was deployed at both sand-dominated (Baynes Sound) and mud-dominated (Carrie Bay) stations in British Columbia, Canada, to examine the character of near-bed flow over these contrasting bottom types and its control on particle size of resuspended sediment. An assessment has also been made of the turbidity-induced drag reduction due to suspension of bottom sediments. The median sizes of suspended material from the sandy sites have been compared with the well-known Rouse theory, whereas the aggregates resuspended from muddy stations were scaled with the energy dissipation rate (ε) determined from high-frequency three-dimensional flow measures in the flume. There was no evidence in the turbulence spectra in the Sea Carousel of energy inputs in the paddle and lid rotational frequencies, and a f–5/3 slope for f > 2 Hz in turbulent transitional flows was evident. The bed roughness length of sandy sites was Reynolds-number dependent but was asymptotic to a constant value of 2 mm at high flows. This equated to a dimensionless drag coefficient at 1 m above bed of a constant, 3 × 10–3 (also at high Reynolds numbers), which agrees well with values reported in the literature. The median size of suspended sand (from the sandy sites) and equivalent still water settling rate (ws) scaled with the friction velocity (u*) in the form ws/u* = D*/8. The median size of resuspended aggregates (df) scaled inversely with dissipation (ε) in the form df = 5 × 10–6ε–0.24m, which is close to the relationship found in the literature.
This paper presents results from experiments in a large flume on wave and flow attenuation by a full-scale artificial Posidonia oceanica seagrass meadow in shallow water. Wave height and in-canopy ...wave-induced flows were reduced by the meadow under all tested regular and irregular wave conditions, and were affected by seagrass density, submergence and distance from the leading edge. The energy of irregular waves was reduced at all components of the spectra, but reduction was greater at the peak spectral frequency. Energy dissipation factors were largest for waves with small orbital amplitudes and at low wave Reynolds numbers. An empirical model, commonly applied to predict friction factors by rough beds, proved applicable to the P. oceanica bed. However at the lowest Reynolds numbers, under irregular waves, the data deviated significantly from the model. In addition, the wave-induced flow dissipation in the lower canopy increased with increasing wave orbital amplitude and increasing density of the mimics. The analysis of the wave-induced flow spectra confirm this trend: the reduction of flow was greatest at the longer period component of the spectra. Finally, we discuss the implications of these findings for sediment dynamics and the role of P. oceanica beds in protecting the shore from erosion.
► Full scale tests with Posidonia oceanica indicate that the seagrass reduces wave energy and wave-induced flows. ► Energy dissipation factors produced by the submerged canopy decay with wave orbital amplitude. ► Energy dissipation may be predicted by existing empirical formulae and canopy roughness may be estimated. ► In-canopy wave-induced flow reduction increases with increasing wave orbital amplitude and with increasing period of the flow spectra component. ► Effects of plant density, submergence ratios (hs/D) and distance from the leading edge were analysed.
Seabed properties in Venice Lagoon were examined in situ in two multidisciplinary field campaigns. The purpose of this study was to understand the mechanisms controlling the stability of bed types. ...Two benthic annular flumes (Sea Carousel and Mini Flume) were deployed simultaneously from a floating pontoon at 24 sites during summer (1998), which were considered representative of the range in bed/habitat types. As well, bottom sampling and coring, water-column monitoring and benthic habitat analyses were carried out. All but three sites were on cohesive sediments. Bed types included bare shelly mudflats and regions colonised by the seagrasses
Cymodocea nodosa and
Zostera noltii, by filamentous cyanobacteria, and by patches of the macrophytes
Ulva rigida and
Chaetomorpha sp. A subset (13) of these sites was visited during the subsequent winter to evaluate seasonal changes. Six of the sites were intertidal, the remainder were in the sublittoral zone.
Water temperature varied between 5 and 30 °C, and salinity varied between 20 and 38 psu. In the absence of waves, turbidity was generally low (<10 mg/l) and was composed of high amounts of organic matter (25–50%). This indicates that the tidal flows were not competent to support estuarine sediment. Higher levels of turbidity were measured during wind events or boat passage as a result of resuspension from the bed. Bed (saturated) density was, on average, 1770 kg/m
3, which was extremely high for estuarine sediments.
Sea Carousel and Mini Flume provided comparable results, despite large differences in instrument footprints. Trends from the two instruments were similar and showed that summertime bed strength exceeded the winter by up to five times. Mean summer erosion thresholds for Sea Carousel and Mini Flume were 1.10 and 0.82 Pa, respectively, whereas during winter, they were 0.69 and 0.74 Pa. The northern lagoon had the most resistant tidal flats due to the stabilizing effect of filamentous cyanobacteria (Biostabilization Index: BI=244%), microphytobenthos (BI=153%) and
Z. noltii (BI=206%). The stabilizing effects of
C. nodosa (BI=74%),
U. rigida (BI=115%) and shell debris (BI=115%) were intermediate, while bare sublittoral mud beds were the least resistant (BI=58%). Summer erosion rates (as a function of applied stress) were lower than winter ones, probably due to water temperature changes. The algorithm
E=
χτ
s
β
, yielded good results and indicated that erosion rates in Venice Lagoon were high, notwithstanding the high erosion thresholds. The mean summertime friction coefficient was
φ=62° and was highest in the central lagoon. The wintertime
φ=69° showed that there was no seasonal fluctuation in bed stability. Mass settling in Venice Lagoon was a strong function of suspended sediment concentration (
S) and a decay constant (
k) of the exponential function
S(
t)=
S
o
e
−
kt
; it was found to be in continuity with examples from other locations worldwide (and therefore normal).
The forthcoming STAMPEDE2 trial has three comparisons in metastatic hormone-sensitive prostate cancer. We aim to determine clinical practices among STAMPEDE trial investigators for access to imaging ...and therapeutic choices and explore their interest in participation in STAMPEDE2.
The survey was developed and distributed online to 120 UK STAMPEDE trial sites. Recipients were invited to complete the survey between 16 and 30 May 2022. The survey consisted of 30 questions in five sections on access to stereotactic ablative body radiotherapy (SABR), 177lutetium-prostate-specific membrane antigen-617 (177Lu-PSMA-617), choice of systemic therapies and use of positron emission tomography/computerised tomography and whole-body magnetic resonance imaging.
From 58/120 (48%) sites, 64 respondents completed the survey: 55/64 (86%) respondents were interested to participate in SABR, 44/64 (69%) in 177Lu-PSMA-617 and 56/64 (87.5%) in niraparib with abiraterone comparisons; 45/64 (70%) respondents had access to bone, spine and lymph node metastases SABR delivery and 7/64 (11%) to 177Lu-PSMA-617. In addition to androgen deprivation therapy, 60/64 (94%) respondents used androgen receptor signalling inhibitors and 46/64 (72%) used docetaxel; 29/64 (45%) respondents would consider triplet therapy with androgen deprivation therapy, androgen receptor signalling inhibitors and docetaxel. Positron emission tomography/computerised tomography was available to 62/64 (97%) respondents and requested by 45/64 (70%) respondents for disease uncertainty on conventional imaging and 39/64 (61%) at disease relapse. Whole-body magnetic resonance imaging was available to 24/64 (38%) respondents and requested by 13/64 (20%) respondents in highly selected patients. In low-volume disease, 38/64 (59%) respondents requested scans at baseline and disease relapse. In high-volume disease, 29/64 (45%) respondents requested scans at baseline, best response (at prostate-specific antigen nadir) and disease relapse; 54/64 (84%) respondents requested computerised tomography and bone scan for best response assessment.
There is noteworthy disparity in clinical practice across current study sites, however most have expressed an interest in participation in the forthcoming STAMPEDE2 trial.
•STAMPEDE trial investigators have great interest in participation in STAMPEDE2.•Metastatic prostate cancer management varies significantly across UK trial sites.•PET/CT imaging is commonly used in various clinical settings.•Triplet systemic therapy will be considered by clinicians with available funding.
The in situ annular flume, Voyager II, was deployed at three sites in the North Sea in order to investigate resuspension events, to determine the physical characteristics of the seabed, to determine ...the threshold of resuspension of the bed and to quantify erosion rates and erosion depths. These are the first controlled, in situ flume experiments to study resuspension in the North Sea, and were combined with long-term measurements of waves and currents. Resuspension experiments were undertaken at two muddy, and one sandy site: north of the Dogger Bank (DG: water depths ∼80
m, very fine, poorly sorted, very fine-skewed sediment experiencing seasonal thermal stratification of the water column along with oxygen depletion); the Oyster Grounds (OG: ∼40
m, similar bed properties, year round water column thermal stratification, Atlantic forcing); and in the Sean Gas Field (SGF: ∼20
m, moderately sorted, very coarse-skewed sand, and well mixed water column). The erosion thresholds of the bed were found to be 0.66–1.04
Pa (DG) and 0.91–1.27
Pa (OG), with corresponding erosion depths of 0.1–0.15
mm and 0.02–0.06
mm throughout the experiments.
Evaluation of a year of current velocities from 2007 indicated that at OG, resuspension of the consolidated bed was limited to on average ∼8% of the time as a result of tidal forcing alone for short (<30
min) durations, but would potentially increase during the winter as a result of wave influences. At DG, under similar conditions this would increase to 13%, and in the SGF, wave-induced resuspension events occurred throughout the year, with the potential exceedance of the threshold for suspension greater than 50% in January and March.
Resuspension of bed material and erosion rates were closely related to applied bed shear stresses, and eroded depths were significantly correlated with the physical properties of the bed. Therefore, while complex variations in biogeophysical factors affected the critical threshold of erosion, once exceeded, erosion rates were related to the nature of the sediment.
► Erosion thresholds, rates and depths were measured using an in situ annular flume. ► Local resuspension most likely driven by waves events. ► Complex variations in biogeophysical factors affect critical threshold of erosion. ► Erosion rates more directly related to nature of sediment.
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