In the Mediterranean Sea, the Strait of Messina (MS) is a very peculiar area, connecting highly different regions and representing a privileged observatory for an early comprehension and assessment ...of ecosystems shifts. It is hypothesized that the outbreaks observed near the coast of many sites in the Mediterranean Sea may be the result of transport of permanent populations of P. noctiluca in pelagic waters to the coast, caused by specific hydrodynamic conditions. By both visual observations and numerical experiments our objective is twofold: (A) to help clarify whether the basin of the Aeolian Islands Archipelago (AIA), in the Southern Tyrrhenian Sea (STS), may be the site from which large populations of P. noctiluca are transported to the MS, and (B) to evaluate whether the upwelling turbulent system of the MS can be an energetic opportunity for this species. It should offer a rich habitat without jeopardizing the overall survival of the population, that is subject to stranding due to strong currents. Although very different, the two involved ecosystems (AIA and MS ) are complementary for the success of Pelagia noctiluca life cycle. Outputs obtained by coupling the 3D hydrodynamic model (SHYFEM) with a Lagrangian particle tracking model support the hypothesis of a connectivity between these two ecosystems, particularly in the first half of the year, indicating the coastal areas around the AIA as potential optimal source location for Pelagia larval stages. We support the very attractive hypothesis that two connected systems exist, the former one favours Pelagia's reproduction and acts as a nursery and the latter favours its growth due to higher productivity. We speculate that the reproductive population of the AIA is not permanent, but is renewed every year by individuals who have fed and quickly grown in the MS and who are passively transported by downwelling along canyon "corridors".
•We have modeled the shelf dense water production and spreading in the Adriatic Sea.•The effect of the 2012 cold air outbreak has been simulated with an ocean-wave modeling system.•Wave-induced ...forcings have been considered during the dense waters generation and spreading phases.•Tides modulate the spreading of dense waters in the Adriatic Sea.
The paper describes formation and spreading of dense shelf waters in the Adriatic Sea (North Adriatic Dense Water, NAdDW) during the winter of 2012 as a consequence of an intense and long cold air outbreak of northeasterly Bora winds. As a result, during February 2012 northern Adriatic Sea water temperature dropped to about 6°C and density exceeded 1030kg/m3, most likely the maximum value since 1929. NAdDW dynamics has been investigated by means of a 3-D ocean-wave coupled model running on a high resolution and eddy-permitting grid. The numerical experiments have relied on the Coupled-Ocean–Atmosphere-Wave-Sediment-Transport (COAWST) system forced one-way with atmospheric forcings provided by the model COSMO-I7. A suite of observational data has been used to characterize the Bora event and evaluate numerical model performance. At sub-basin scales, the newly formed waters flowing southerly have produced a water renewal of the northern Adriatic, as more than 50% of water volumes have left the basin. Dense waters volume transports, evaluated through different Adriatic cross-sections, have been modulated by tides (damped for the densest water masses) and reached about 1Sv. The contribution of wave-induced forcings has been quantified and examined, indicating that these represent a major driving mechanism during NAdDW production and spreading phases. This work provides evidence that NAdDW is spread accordingly with two different mechanisms: at early stages of its formation, the wind-driven ocean circulation pushes newly formed waters to leave the northern basin with relatively high speeds (about 0.30m/s). Later on, remaining NAdDW leaks slowly out (0.09m/s as average) from the production site. Residence times of dense waters in the north, middle, and south Adriatic Sea are also documented.
Amos, C.L.; Kassem, H.; Bergamasco, A.; Sutherland, T.F., and Cloutier, D., 2021. The mass settling flux of suspended particulate matter in Venice Lagoon, Italy. Journal of Coastal Research, 37(6), ...1099–1116. Coconut Creek (Florida), ISSN 0749-0208. A multidisciplinary study of the stability of the tidal flats of Venice Lagoon has provided field and laboratory data on the factors influencing the mass settling rates of material in suspension. This work was performed using two in situ benthic flumes (Sea Carousel and Mini Flume) in association with a wide range of physical and biological measurements undertaken during the summer of 1998 and the subsequent winter. Also, controlled experiments on erosion/sedimentation of prepared beds were carried out using Lab Carousel, a laboratory equivalent of Sea Carousel. Particle size and mass settling rates were found to be largely independent of suspended sediment concentration but strongly controlled by the antecedent bed shear stresses that led to the suspension. Results between the three flume types differed because of differences in the induced stress history created in each case. Comparable results were obtained by normalizing mass settling rate to the mean friction velocity of the flow during settling, i.e. the Rouse parameter () , and by use of the mean dimensionless particle diameter (D*). Results fell in line with results on carbonate and silica sands of the inlets of the lagoon. The mean particle diameter (df) varied in proportion to the applied shear stress and shear rate (G) suggesting that the suspended particles were eroded aggregates not floccules. The effective density of these aggregates was least (∼16 kgm–3) at the largest sizes (df > 1 × 10–4 m) and greatest (∼160–1600 kgm–3) at the smallest sizes (df < 1 × 10–4 m). The lack of an increase in df at low shear rates suggests that flocculation was not taking place. The mean deposition threshold (all experiments) was 0.68 Pa, which is less than the mean erosion threshold from these sites (0.78 Pa).
The Terra Nova Bay (TNB) and Ross Ice Shelf (RIS) polynyas are simulated using a coupled atmosphere–sea ice model in winter 2002 and summer 2000. The atmospheric component of the model is compared ...with Automatic Weather Stations (AWS) data and shows a significantly increased skill over the ECMWF atmospheric variables. During winter, the sea ice production in TNB is largely determined by katabatic winds. We estimate the monthly production rate to be 8.7 km3/month of sea ice during winter. In early summer (November), the katabatics are weaker and the sea ice production is more influenced by the synoptic wind. The net sea ice production is weaker during November at 1.2 km3/month. The summer production is characterized by a diurnal cycle of melt and sea ice formation. For small coastal polynyas, like TNB, it is important to resolve all the glacier valleys accurately. Increasing the model resolution by a factor of five leads to a doubling of the sea ice formation during winter simulations due to the point intensity of the katabatics winds. For open coastal polynyas, like RIS polynya, sea ice production is largely controlled by synoptic winds and resolution is less important. The RIS polynya production is 61.3 km3 during winter and 19.1 km3 during November. These results are comparable to RIS polynya observations. Although the TNB polynya has a smaller winter sea ice production, the sea ice rate of growth per unit area is 1.6 times that of the RIS polynya.
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).
Although hereditary von Willebrand disease (VWD) is the most common bleeding disorder, its epidemiology is not well understood. A systematic review (PROSPERO CRD42020197674/CRD42021244374) on the ...epidemiology/burden of illness of VWD was conducted to better understand patients' unmet needs.
Observational studies (published January 1, 2010 to April 14, 2021) were identified in MEDLINE and Embase databases, using free-text keywords and thesaurus terms for VWD and outcomes of interest. Pragmatic web-based searches of the gray literature, including conference abstracts, were performed, and reference lists of retained publications were manually searched for additional sources. Case reports and clinical trials (phase 1-3) were excluded. Outcomes of interest were incidence, prevalence, mortality, patient characteristics, burden of illness, and therapeutic management/treatments currently used for VWD.
Of the 3095 identified sources, 168 were included in this systematic review. Reported VWD prevalence (22 sources) ranged from 108.9 to 2200 per 100,000 in population-based studies and from 0.3 to 16.5 per 100,000 in referral-based studies. Reported times between first symptom onset and diagnosis (two sources; mean 669 days; median 3 years) highlighted gaps in timely VWD diagnosis. Bleeding events reported in 72-94% of the patients with VWD (all types; 27 sources) were mostly mucocutaneous including epistaxis, menorrhagia, and oral/gum bleeding. Poorer health-related quality of life (three sources) and greater health care resource utilization (three sources) were reported for patients with VWD than in general populations.
Available data suggest that patients with VWD experience high disease burden in terms of bleeding, poor quality of life, and health care resource utilization.
Global solutions to involutive systems BERGAMASCO, A. P.; KIRILOV, A.; NUNES, W. V. L. ...
Proceedings of the American Mathematical Society,
November 1, 2015, 20151101, 2015-11-00, Letnik:
143, Številka:
11
Journal Article
Recenzirano
Odprti dostop
In this work we consider a class of systems of two vector fields on the 3-torus associated to a closed smooth complex 1-form c=a+ib exact. Necessary conditions and sufficient conditions for this ...system to be globally solvable are provided in terms of the position of the global extrema and the connectedness of sublevel and superlevel sets of the primitives of b.
Resistance training (RT) induces muscle growth at varying rates across RT phases, and evidence suggests that the muscle-molecular responses to training bouts become refined or attenuated in the ...trained state. This study examined how proteolysis-related biomarkers and extracellular matrix (ECM) remodeling factors respond to a bout of RT in the untrained (UT) and trained (T) state.
Participants (19 women and 19 men) underwent 10 weeks of RT. Biopsies of vastus lateralis were collected before and after (24 h) the first (UT) and last (T) sessions. Vastus lateralis cross-sectional area (CSA) was assessed before and after the experimental period.
There were increases in muscle and type II fiber CSAs. In both the UT and T states, calpain activity was upregulated and calpain-1/-2 protein expression was downregulated from Pre to 24 h. Calpain-2 was higher in the T state. Proteasome activity and 20S proteasome protein expression were upregulated from Pre to 24 h in both the UT and T. However, proteasome activity levels were lower in the T state. The expression of poly-ubiquitinated proteins was unchanged. MMP activity was downregulated, and MMP-9 protein expression was elevated from Pre to 24 h in UT and T. Although MMP-14 protein expression was acutely unchanged, this marker was lower in T state. TIMP-1 protein levels were reduced Pre to 24 h in UT and T, while TIMP-2 protein levels were unchanged.
Our results are the first to show that RT does not attenuate the acute-induced response of proteolysis and ECM remodeling-related biomarkers.
A year-long controlled growth experiment of 60 specimens of the Antarctic bivalve Adamussium colbecki was conducted in Terra Nova Bay (Ross Sea) to evaluate its reliability as a suitable archive of ...water mass properties. Nine shells were sub-sampled for stable oxygen and carbon isotope analysis to study the inter and intra specimen variations. Slow-growing A. colbecki precipitate their calcitic shells close to the expected oxygen and carbon isotopic equilibrium, whereas the fast-growing individuals are strongly influenced by biogenetic and kinetic effects. The equation of Kim and O'Neil (1997) is considered a fair approximation for the δ18O-temperature relationship in slow-growing individuals. The reconstructed temperature is closer to the mean experimental summer temperature than the annual one. This fact is interpreted as reflecting a possible winter decrease of shell growth, the salinity variation and the corrections for negative temperature on calibrating the δ18O-temperature relationship. Our results support the hypothesis that A. colbecki might represent a good archive for encoding Antarctic Shelf water summer temperature information. Further improvements in adopting A. colbecki as a paleotemperature archive will require the evaluation of the seasonal variability in shell growth rate through culturing slow-growing A. colbecki individuals at near-freezing temperatures to calibrate a species-specific δ18O-temperature equation.
► Intra and inter specimen investigation on A. colbecki isotope equilibrium ► Slow-growing shells are mineralize homogenously in isotopic equilibrium. ► Kim and O'Neil's equation approximates well the A. colbecki δ18O–temperature relation. ► Mean temperature estimation analytical error is ±0.5°C and specimen variability is ±1°C. ► A. colbecki is potentially a good summer temperature proxy for Antarctic Shelf waters.
PDF
