scholarly journals Current temporal asymmetry and the role of tides: Nan-Wan Bay vs. the Gulf of Elat

2016 ◽  
Author(s):  
Yosef Ashkenazy ◽  
Erick Fredj ◽  
Hezi Gildor ◽  
Gwo-Ching Gong ◽  
Hung-Jen Lee
Keyword(s):  
Shape Parameter ◽  
Current Speed ◽  
Statistical Properties ◽  
Coastal Environments ◽  
Current Field ◽  
Temporal Asymmetry ◽  
The Mean ◽  
The Asymmetry ◽  
Mean Current

Abstract. Nan-Wan Bay in Taiwan and the Gulf of Elat in Israel are two different coastal environments, and as such, their currents are expected to have different statistical properties. While Nan-Wan Bay is shallow, has three open boundaries, and is directly connected to the open ocean, the Gulf of Elat is deep, semi-enclosed, and connected to the Red Sea via the Straits of Tiran. Surface currents have been continuously measured with fine temporal (less than or equal to one hour) and spatial resolution (less than or equal to one km) for more than a year in both environments using coastal radars (CODARs) that cover a domain of roughly 10 × 10 kms. These measurements show that the currents in Nan-Wan Bay are much stronger than those in the Gulf of Elat and that the mean current field in Nan-Wan Bay exhibits cyclonic circulation, which is stronger in the summer; in the Gulf of Elat, the mean current field is directed southward and is also stronger during the summer. We have compared the statistical properties of the current speeds in both environments and found that both exhibit large spatial and seasonal variations in the shape parameter of the Weibull distribution. However, we have found fundamental and significant differences when comparing the temporal asymmetry of the current speed (i.e., the ratio between the time during which the current speed increases and the total time). While the Nan-Wan Bay currents are significantly asymmetric, those of the Gulf of Elat are not. We then extracted the tidal component of the Nan-Wan Bay currents and found that it is strongly asymmetric, while the asymmetry of tidally filtered currents is much weaker. We thus conclude that the temporal asymmetry of the Nan-Wan Bay currents reported here is due to the strong tides in the region. We show that the asymmetry ratio in Nan-Wan Bay varies spatially and seasonally: (i) the currents increase rapidly and decay slowly in the northern part of the domain and vice versa in the southern part, and (ii) the asymmetry is stronger during summer.

scholarly journals Current temporal asymmetry and the role of tides: Nan-Wan Bay vs. the Gulf of Elat

Ocean Science ◽  
2016 ◽  
Vol 12 (3) ◽  
pp. 733-742 ◽  
Author(s):  
Yosef Ashkenazy ◽  
Erick Fredj ◽  
Hezi Gildor ◽  
Gwo-Ching Gong ◽  
Hung-Jen Lee
Keyword(s):  
Shape Parameter ◽  
Current Speed ◽  
Statistical Properties ◽  
Coastal Environments ◽  
Current Field ◽  
Temporal Asymmetry ◽  
The Mean ◽  
The Asymmetry ◽  
Mean Current

Abstract. Nan-Wan Bay in Taiwan and the Gulf of Elat in Israel are two different coastal environments, and as such, their currents are expected to have different statistical properties. While Nan-Wan Bay is shallow, has three open boundaries, and is directly connected to the open ocean, the Gulf of Elat is deep, semi-enclosed, and connected to the Red Sea via the Straits of Tiran. Surface currents have been continuously measured with fine temporal (less than or equal to 1 h) and spatial resolution (less than or equal to 1 km) for more than a year in both environments using coastal radars (CODARs) that cover a domain of roughly 10  ×  10 km. These measurements show that the currents in Nan-Wan Bay are much stronger than those in the Gulf of Elat and that the mean current field in Nan-Wan Bay exhibits cyclonic circulation, which is stronger in the summer; in the Gulf of Elat, the mean current field is directed southward and is also stronger during the summer. We have compared the statistical properties of the current speeds in both environments and found that both exhibit large spatial and seasonal variations in the shape parameter of the Weibull distribution. However, we have found fundamental and significant differences when comparing the temporal asymmetry of the current speed (i.e., the ratio between the time during which the current speed increases and the total time). While the Nan-Wan Bay currents are significantly asymmetric, those of the Gulf of Elat are not. We then extracted the tidal component of the Nan-Wan Bay currents and found that it is strongly asymmetric, while the asymmetry of tidally filtered currents is much weaker. We thus conclude that the temporal asymmetry of the Nan-Wan Bay currents reported here is due to the strong tides in the region. We show that the asymmetry ratio in Nan-Wan Bay varies spatially and seasonally: (i) the currents increase rapidly and decay slowly in the northern part of the domain and vice versa in the southern part, and (ii) the asymmetry is stronger during summer.

scholarly journals Four Current Meter Models Compared in Strong Currents in Drake Passage

2013 ◽  
Vol 30 (10) ◽  
pp. 2465-2477 ◽  
Author(s):  
D. Randolph Watts ◽  
Maureen A. Kennelly ◽  
Kathleen A. Donohue ◽  
Karen L. Tracey ◽  
Teresa K. Chereskin ◽  
...  
Keyword(s):  
Drake Passage ◽  
Current Speed ◽  
The Other ◽  
High Current ◽  
Velocity Measurements ◽  
Time Intervals ◽  
Current Events ◽  
The Mean ◽  
Reference Measurements ◽  
Mean Current

Abstract Seven current meters representing four models on a stiffly buoyed mooring were placed for an 11-month deployment to intercompare their velocity measurements: two vector-measuring current meters (VMCMs), two Aanderaa recording current meter (RCM) 11s, two Aanderaa SEAGUARDs, and a Nortek Aquadopp. The current meters were placed 6-m apart from each other at about 4000-m depth in an area of Drake Passage expected to have strong currents, nearly independent of depth near the bottom. Two high-current events occurred in bursts of semidiurnal pulses lasting several days, one with peak speeds up to 67 cm s−1 and the other above 35 cm s−1. The current-speed measurements all agreed within 7% of the median value when vector averaged over simultaneous time intervals. The VMCMs, chosen as the reference measurements, were found to measure the median of the mean-current magnitudes. The RCM11 and SEAGUARD current speeds agreed within 2% of the median at higher speeds (35–67 cm s−1), whereas in lower speed ranges (0–35 cm s−1) the vector-averaged speeds for the RCM11 and SEAGUARD were 4%–5% lower and 3%–5% higher than the median, respectively. The shorter-record Aquadopp current speeds were about 6% higher than the VMCMs over the range (0–40 cm s−1) encountered.

A Multimoment Bulk Microphysics Parameterization. Part I: Analysis of the Role of the Spectral Shape Parameter

2005 ◽  
Vol 62 (9) ◽  
pp. 3051-3064 ◽  
Author(s):  
J. A. Milbrandt ◽  
M. K. Yau
Keyword(s):  
Growth Rates ◽  
Moment Method ◽  
Shape Parameter ◽  
Number Concentration ◽  
Spectral Shape ◽  
Size Spectrum ◽  
Atmospheric Models ◽  
Size Sorting ◽  
The Mean

Abstract With increasing computer power, explicit microphysics schemes are becoming increasingly important in atmospheric models. Many schemes have followed the approach of Kessler in which one moment of the hydrometeor size distribution, proportional to the mass content, is predicted. More recently, the two-moment method has been introduced in which both the mass and the total number concentration of the hydrometeor categories are independently predicted. In bulk schemes, the size spectrum of each hydrometeor category is often described by a three-parameter gamma distribution function, N(D) = N0Dαe−λD. Two-moment schemes generally treat N0 and λ as prognostic parameters while holding α constant. In this paper, the role of the spectral shape parameter, α, is investigated by examining its effects on sedimentation and microphysical growth rates. An approach is introduced for a two-moment scheme where α is allowed to vary diagnostically as a function of the mean-mass diameter. Comparisons are made between calculations using various bulk approaches—a one-moment, a two-moment, and a three-moment method—and an analytic bin model. It is found that the size-sorting mechanism, which exists in a bulk scheme when different fall velocities are applied to advect the different predicted moments, is significantly different amongst the schemes. The shape parameter plays an important role in determining the rate of size sorting. Likewise, instantaneous growth rates related to the moments are shown to be significantly affected by this parameter.

Muscarinic modulation of voltage-dependent Ca2+ channels in insulin-secreting HIT-T15 cells

1998 ◽  
Vol 274 (2) ◽  
pp. G397-G405 ◽  
Author(s):  
Jeffrey A. Love ◽  
Neil W. Richards ◽  
Chung Owyang ◽  
David C. Dawson
Keyword(s):  
High Threshold ◽  
Muscarinic Agonist ◽  
Kinase C ◽  
Open Time ◽  
Voltage Dependent ◽  
The Mean ◽  
Mean Current ◽  
Muscarinic Modulation ◽  
Ca2 Channels

Potentiation of insulin secretion from pancreatic β-cells by acetylcholine requires ongoing cyclic electrical activity initiated by other depolarizing secretagogues. Patch-clamp recordings in glucose-free solutions were made from the clonal β-cell line HIT-T15 to determine whether the muscarinic agonist bethanechol (BCh) modulated voltage-dependent Ca2+ channels independent of effects on membrane potential. Only high-threshold, dihydropyridine-sensitive (L-type) Ca2+ channels with a mean conductance of 26 pS were observed in cell-attached patches. BCh (100 μM) caused a two- to threefold increase in both fractional open time and mean current of single Ca2+channels. These changes resulted from a 44% decrease in the longer of two apparent mean closed times and a 25% increase in the mean open time. Similar BCh-stimulated increases in macroscopic Ca2+ currents were recorded in whole cell, perforated-patch recordings. The role of protein kinase C (PKC) in the muscarinic activation of Ca2+ channels was tested using a variety of PKC activators and inhibitors. Acute application of either the active phorbol ester phorbol 12-myristate 13-acetate (PMA) or the membrane-permeable diacylglycerol analog 1,2-didecanoyl- rac-glycerol mimicked the effects of BCh, whereas an inactive phorbol (4α) had no effect. Depletion of PKC activity by chronic exposure to PMA or acute application of the PKC inhibitor staurosporine greatly reduced or abolished muscarinic activation of Ca2+ channels. These results are consistent with muscarinic activation of L-type, voltage-dependent Ca2+ channels mediated in large part by PKC.

Long-term dynamics and destruction of marsh vegetation in the Kolokolkova Bay of the Barents Sea

2012 ◽  
pp. 66-77 ◽  
Author(s):  
I. A. Lavrinenko ◽  
O. V. Lavrinenko ◽  
D. V. Dobrynin
Keyword(s):  
Species Composition ◽  
Plant Communities ◽  
Barents Sea ◽  
Mean Value ◽  
Marsh Vegetation ◽  
Composition And Structure ◽  
The Mean ◽  
Species Composition And Structure

The satellite images show that the area of marshes in the Kolokolkova bay was notstable during the period from 1973 up to 2011. Until 2010 it varied from 357 to 636 ha. After a severe storm happened on July 24–25, 2010 the total area of marshes was reduced up to 43–50 ha. The mean value of NDVI for studied marshes, reflecting the green biomass, varied from 0.13 to 0.32 before the storm in 2010, after the storm the NDVI decreased to 0.10, in 2011 — 0.03. A comparative analysis of species composition and structure of plant communities described in 2002 and 2011, allowed to evaluate the vegetation changes of marshes of the different topographic levels. They are fol­lowing: a total destruction of plant communities of the ass. Puccinellietum phryganodis and ass. Caricetum subspathaceae on low and middle marches; increasing role of halophytic species in plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. typicum on middle marches; some changes in species composition and structure of plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. festucetosum rubrae on high marches and ass. Parnassio palustris–Salicetum reptantis in transition zone between marches and tundra without changes of their syntaxonomy; a death of moss cover in plant communities of the ass. Caricetum mackenziei var. Warnstorfia exannulata on brackish coastal bogs. The possible reasons of dramatic vegetation dynamics are discussed. The dating of the storm makes it possible to observe the directions and rates of the succession of marches vegetation.

Seasonal trends in the stable isotopic composition of snow and meltwater runoff in a subarctic catchment at Okstindan, Norway

2004 ◽  
Vol 35 (2) ◽  
pp. 119-137 ◽  
Author(s):  
S.D. Gurney ◽  
D.S.L. Lawrence
Keyword(s):  
Isotopic Composition ◽  
Mean Value ◽  
Mean Values ◽  
Stable Isotopic Composition ◽  
Meltwater Runoff ◽  
Stable Isotopic ◽  
The Mean ◽  
The Difference ◽  
Δ18o And Δd

Seasonal variations in the stable isotopic composition of snow and meltwater were investigated in a sub-arctic, mountainous, but non-glacial, catchment at Okstindan in northern Norway based on analyses of δ18O and δD. Samples were collected during four field periods (August 1998; April 1999; June 1999 and August 1999) at three sites lying on an altitudinal transect (740–970 m a.s.l.). Snowpack data display an increase in the mean values of δ18O (increasing from a mean value of −13.51 to −11.49‰ between April and August), as well as a decrease in variability through the melt period. Comparison with a regional meteoric water line indicates that the slope of the δ18O–δD line for the snowpacks decreases over the same period, dropping from 7.49 to approximately 6.2.This change points to the role of evaporation in snowpack ablation and is confirmed by the vertical profile of deuterium excess. Snowpack seepage data, although limited, also suggest reduced values of δD, as might be associated with local evaporation during meltwater generation. In general, meltwaters were depleted in δ18O relative to the source snowpack at the peak of the melt (June), but later in the year (August) the difference between the two was not statistically significant. The diurnal pattern of isotopic composition indicates that the most depleted meltwaters coincide with the peak in temperature and, hence, meltwater production.

scholarly journals Forensic Investigation of Four Monitored Green Infrastructure Inlets

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1787
Author(s):  
Leena J. Shevade ◽  
Franco A. Montalto
Keyword(s):  
Measurement Uncertainty ◽  
Green Infrastructure ◽  
Stormwater Management ◽  
Catchment Area ◽  
Low Flow ◽  
Inflow Rate ◽  
Forensic Investigation ◽  
Flow Conditions ◽  
The Mean

Green infrastructure (GI) is viewed as a sustainable approach to stormwater management that is being rapidly implemented, outpacing the ability of researchers to compare the effectiveness of alternate design configurations. This paper investigated inflow data collected at four GI inlets. The performance of these four GI inlets, all of which were engineered with the same inlet lengths and shapes, was evaluated through field monitoring. A forensic interpretation of the observed inlet performance was conducted using conclusions regarding the role of inlet clogging and inflow rate as described in the previously published work. The mean inlet efficiency (meanPE), which represents the percentage of tributary area runoff that enters the inlet was 65% for the Nashville inlet, while at Happyland the NW inlet averaged 30%, the SW inlet 25%, and the SE inlet 10%, considering all recorded events during the monitoring periods. The analysis suggests that inlet clogging was the main reason for lower inlet efficiency at the SW and NW inlets, while for the SE inlet, performance was compromised by a reverse cross slope of the street. Spatial variability of rainfall, measurement uncertainty, uncertain tributary catchment area, and inlet depression characteristics are also correlated with inlet PE. The research suggests that placement of monitoring sensors should consider low flow conditions and a strategy to measure them. Additional research on the role of various maintenance protocols in inlet hydraulics is recommended.

scholarly journals High Ripple-Density Resolution for Discriminating Between Rippled and Nonrippled Signals: Effect of Temporal Processing or Combination Products?

2021 ◽  
Vol 25 ◽  
pp. 233121652110101
Author(s):  
Dmitry I. Nechaev ◽  
Olga N. Milekhina ◽  
Marina S. Tomozova ◽  
Alexander Y. Supin
Keyword(s):  
Low Frequency ◽  
Noise Signal ◽  
Density Variation ◽  
Choice Procedure ◽  
Masker Level ◽  
Reference Signals ◽  
Forced Choice Procedure ◽  
The Mean ◽  
Density Resolution

The goal of the study was to investigate the role of combination products in the higher ripple-density resolution estimates obtained by discrimination between a spectrally rippled and a nonrippled noise signal than that obtained by discrimination between two rippled signals. To attain this goal, a noise band was used to mask the frequency band of expected low-frequency combination products. A three-alternative forced-choice procedure with adaptive ripple-density variation was used. The mean background (unmasked) ripple-density resolution was 9.8 ripples/oct for rippled reference signals and 21.8 ripples/oct for nonrippled reference signals. Low-frequency maskers reduced the ripple-density resolution. For masker levels from −10 to 10 dB re. signal, the ripple-density resolution for nonrippled reference signals was approximately twice as high as that for rippled reference signals. At a masker level as high as 20 dB re. signal, the ripple-density resolution decreased in both discrimination tasks. This result leads to the conclusion that low-frequency combination products are not responsible for the task-dependent difference in ripple-density resolution estimates.

scholarly journals Trends and Clinico-Epidemiological Features of Human Rabies Cases in Bangladesh, 2006–2018

2020 ◽  
Vol 41 (S1) ◽  
pp. s416-s416
Author(s):  
Sumon Ghosh ◽  
Md. Sohel Rana ◽  
Sukanta Chowdhury
Keyword(s):  
Effective Means ◽  
Scale Up ◽  
Traditional Healers ◽  
Human Rabies ◽  
Epidemiological Analysis ◽  
Increasing Trend ◽  
The Mean ◽  
Death Cases ◽  
Death Data

Background: Vaccinating dogs against rabies is an effective means of reducing human rabies. Methods: We analyzed 1,327 clinically diagnosed human rabies deaths and mass dog vaccination (MDV) data during 2006–2018 to quantify the impacts of MDV on human rabies incidence in Bangladesh and a subset of rabies death data (n = 422) for clinico-epidemiological analysis. Results: We found a positive and increasing trend of dog population vaccination (P = .01 and τ = 0.71) and a negative and declining trend (P < .001 and τ = −0.88) of human rabies cases (correlation coefficient, −0.82). Among 422 human rabies death cases, most victims (78%) sought treatment from traditional healers, and 12% received postexposure prophylaxis (PEP). The mean incubation period of rabies cases with exposure sites on the head and neck (35 days) was shorter than the upper limb (mean, 64 days; P = .02) and lower limb (mean, 89 days; P < .01). MDV is effective for reducing human rabies cases in Bangladesh. Conclusions: Creating awareness among the animal bite victims to stop relying on traditional healers rather seeking PEP, addressing the role of traditional healers through an awareness education program in respect to the treatment of dog bites, ensuring availability of PEP, and continuing to scale up MDV can help prevent human rabies deaths.Funding: NoneDisclosures: None

scholarly journals SAT0267 ROLE OF AGGRESSIVE IMMUNOSUPPRESSION ON SUBGLOTTIC STENOSIS IN GRANULOMATOSIS WITH POLYANGIITIS: RETROSPECTIVE ANALYSIS OF A MONOCENTRIC COHORT

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1076.1-1077
Author(s):  
L. Moroni ◽  
L. Giudice ◽  
G. A. Ramirez ◽  
S. Sartorelli ◽  
A. Cariddi ◽  
...  
Keyword(s):  
Medical Treatment ◽  
Clinical Characteristics ◽  
Granulomatosis With Polyangiitis ◽  
Balloon Catheter ◽  
Subglottic Stenosis ◽  
Damage Accrual ◽  
The Mean ◽  
The One

Background:Subglottic stenosis (SGS) is defined as airway narrowing below the vocal cords and is a common and potentially life-threatening manifestation of Granulomatosis with Polyangiitis (GPA), with an estimated prevalence of 16-23% (1). Balloon catheter dilation is effective in GPA-related SGS, but relapses are frequent. Little is known about the role of immunosuppression in this setting.Objectives:to analyse the clinical characteristics of a monocentric GPA cohort, describe phenotype differences among patients with and without SGS and investigate the role of surgical and medical treatments on relapse risk and general outcome.Methods:Biopsy-proven patients with SGS were identified by review of medical charts among a cohort of patients with GPA, classified according to the algorithm of the European Medicine Agency (2). The clinical characteristics of patients with SGS were retrospectively collected over a median follow-up time of 15.9 years and compared to those of patients without SGS.Results:Fourteen patients with SGS-GPA were identified, with a female to male ratio of 1:1 and a prevalence of 29.2% among the cohort. The mean ± SD age at GPA onset was 30.8 ± 14.4 years, with a mean time from GPA diagnosis to SGS onset of 4.7 ± 4.2 years. ANCA were positive in 78.6% (54.0% anti-PR3, 18.1% anti-MPO and 27.9% IFI only). The mean Birmingham Vasculitis Activity Score (BVAS) at onset was 10.0 ± 5.6. The main clinical manifestations associated with SGS were crusty rhinitis (100%), sinusitis (78%), pulmonary disease (72.7%), otitis/mastoiditis (50%), glomerulonephritis (42.9%), orbital pseudotumor (28.6%). Six patients (42.9%) received medical treatment only, other six (42.9%) had one to three balloon dilations and two (14.2%) underwent four or more procedures. Eight patients had no SGS relapse (maximum one dilation) and they all received immunosuppression with rituximab (RTX), cyclophosphamide (CYC) or azathioprine (AZA). All patients who received no immunosuppression, methotrexate (MTX) or mycophenolate (MMF) had at least one relapse. Patients treated with MTX or MMF had a mean relapse-free survival of 13.1 months, which was comparable to the one of patients not receiving medical treatment (40.2 months; p=NS) and shorter than the one of patients receiving CYC or RTX (153.2 months; p=0.032). CYC use also inversely correlated with the number of surgical procedures (r=-0.691, p=0.006). Compared to patients without SGS (31 consecutive patients with at least 4 years of follow-up), patients with SGS-GPA had an earlier disease onset (mean age 30.8 vs 50.4 years; p<0.001), but with lower BVAS (mean 10.0 vs 15.3; p=0.013) and showed a higher prevalence of crusty rhinitis (100% vs 67.7%; p=0.019). No difference was observed in damage accrual over time between the two groups.Conclusion:Subglottic stenosis is highly prevalent in patients with GPA and may define a milder disease subset occurring more frequently in younger patients. MTX and MMF might be insufficient to prevent SGS relapses requiring balloon dilation. Aggressive immunosuppression (CYC or RTX) might have a non-redundant role in this setting and reduce the risk of relapses.References:[1]Quinn KA, et al. Subglottic stenosis and endobronchial disease in granulomatosis with polyangiitis. Rheumatology 2019; 58 (12), 2203-2211.[2]Watts R, et al. Development and validation of a consensus methodology for the classification of the ANCA associated vasculitides and polyarteritis nodosa for epidemiological studies. Ann Rheum Dis 2007; 66: 222-7.Disclosure of Interests:Luca Moroni: None declared, Laura Giudice: None declared, Giuseppe Alvise Ramirez: None declared, Silvia Sartorelli: None declared, adriana cariddi: None declared, Angelo Carretta: None declared, Enrica Bozzolo: None declared, Lorenzo Dagna Grant/research support from: The Unit of Immunology, Rheumatology, Allergy and Rare Diseases (UnIRAR) received unresctricted research/educational grants from Abbvie, Bristol-Myers Squibb, Celgene, Janssen, Merk Sharp & Dohme, Mundipharma Pharmaceuticals, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI., Consultant of: Prof Lorenzo Dagna received consultation honoraria from Abbvie, Amgen, Biogen, Bristol-Myers Squibb, Celltrion, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI.

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