Passage Of Vessels Research Articles

Ice conditions affecting passage of Polish vessels convoy though the NSR in 1956. Long-term ice forecasts and passage strategies

Ice conditions affecting passage of Polish vessels convoy though the NSR in 1956. Long-term ice forecasts and passage strategies

Vessel noise cuts down communication space for vocalizing fish and marine mammals.

Anthropogenic noise across the world's oceans threatens the ability of vocalizing marine species to communicate. Some species vocalize at key life stages or whilst foraging, and disruption to the acoustic habitat at these times could lead to adverse consequences at the population level. To investigate the risk of these impacts, we investigated the effect of vessel noise on the communication space of the Bryde's whale Balaenoptera edeni, an endangered species which vocalizes at low frequencies, and bigeye Pempheris adspersa, a nocturnal fish species which uses contact calls to maintain group cohesion while foraging. By combining long-term acoustic monitoring data with AIS vessel-tracking data and acoustic propagation modelling, the impact of vessel noise on their communication space was determined. Routine vessel passages cut down communication space by up to 61.5% for bigeyes and 87.4% for Bryde's whales. This influence of vessel noise on communication space exceeded natural variability for between 3.9 and 18.9% of the monitoring period. Additionally, during the closest point of approach of a large commercial vessel, <10km from the listening station, the communication space of both species was reduced by a maximum of 99% compared to the ambient soundscape. These results suggest that vessel noise reduces communication space beyond the evolutionary context of these species and may have chronic effects on these populations. To combat this risk, we propose the application or extension of ship speed restrictions in ecologically significant areas, since our results indicate a reduction in sound source levels for vessels transiting at lower speeds.

Estimating River Bathymetry from Surface Velocity Observations Using Variational Inverse Modeling

AbstractAccurate river bathymetry characterization is important to understanding all aspects of the riparian environment and provides crucial information for ensuring the safe passage of vessels and guiding channel maintenance operations. Verified models based on readily collected physical data facilitate accurate predictions of changes to a riverbed caused by traffic, weather, and other influences. This paper presents a methodology for estimating river bathymetry from surface velocity data by applying variational inverse modeling to the shallow-water equations. The paper describes the mathematical framework for the methodology and the algorithm, and the numerical tools developed to test the methodology. The hydrodynamic modeling uses 2D depth-averaged solvers (under the hydrostatic assumption) and applies a standard empirical correlation that relates depth-averaged velocity to surface velocity. The application of the bathymetry estimation algorithm to water-surface velocity data was tested on a 95-km reach of the Columbia River in Washington State. The root-mean-square error (RMSE) of the estimated bathymetry field relative to the ground truth data is approximately 2 m over the entire reach. The results of the test case indicate that this approach can be used to estimate river bathymetry to a close approximation based on the bank-to-bank surface velocity data on the reach of interest.

Exploring spatial and temporal trends in the soundscape of an ecologically significant embayment

The Hauraki Gulf, a shallow embayment in north-eastern New Zealand, provides an interesting environment for ecological soundscape research. It is situated on a tectonic plate boundary, contains one of the busiest ports in the southern hemisphere and is home to a diverse range of soniferous animals. The underwater soundscape was monitored for spatial and temporal trends at six different listening stations using passive acoustic recorders. The RMS sound pressure level of ambient sound (50–24,000 Hz) at the six listening stations was similar, ranging from 90–110 dB re 1 μPa throughout the recording period. Biophony had distinct temporal patterns and biological choruses of urchins were significantly correlated to temperature. Geophony and biophony followed the acoustic niche hypothesis, where each sound exhibited both temporal and frequency partitioning. Vessel passage sound were identified in 1.9–35.2% of recordings from the different listening stations. Vessel sound recorded in the Hauraki Gulf has the potential to mask concurrent geophony and biophony, sounds that may be important to marine life. This study provides a baseline of ambient sound, useful for future management strategies in shallow embayments where anthropogenic pressure is likewise increasing.

Morphological comparison of the pudendal canal and its neurovascular elements in human and domestic mammals

The structural organization of the pelvis and perineum is complex and poorly understood, especially in non‐primate mammals. A relevant feature of these regions is the pudendal canal, which is the passage for the pudendal vessels and nerve at the caudal surface of the pelvic diaphragm (coccygeous and levator ani muscles). These elements are responsible for the blood supply and innervation of the perineum and involve extensive consideration in numerous clinical interventions. The pudendal canal is well described in humans, but not in other species. Therefore, with the aim of studying and comparing the pudendal canal and its neurovascular elements we dissected the pelvic diaphragm and traced the pudendal vessels and nerve in dogs (n=20), goats (n=10), pigs (n=10), horse (n=5), cats (n=3), and humans (n=20). We found that, unlike humans, the pudendal canal in domestic animals is a narrow passage that results from the extensive union of the pelvic diaphragm to the pelvic wall. In large animals, the pelvic diaphragm was a simple muscular layer with a prominent insertion in the external anal sphincter. In small animals, the diaphragm is formed by a group of muscular bundles with greater insertion at the caudal vertebrae. The presence of nerves were variable according to the specific conformation of the sacral plexus. However, the branching pattern of the pudendal vessels and nerve were similar. A notable feature in domestic animals was the presence of the caudal rectal nerve inside the pudendal canal, which is not a feature normally found in humans.

Galectin-3: A Heart Failure Biomarker as Sign of Active Coronary Heart Disease

Atherosclerosis is characterized by the accumulation of cholesterol esters, macrophages and fibrous elements on the inner artery wall. This process begins with accumulation of plasma lipoproteins on the inner wall of the artery, which leads to changes in the passage and elasticity of the blood vessels. Monocytes penetrating the arterial wall transforms into macrophages which digest cholesterol and form foam cells which is one of the first steps in atherosclerotic process. Activation of macrophages is affected by galectin-3, a β-galactoside-binding lectin which is also involved in cardiac remodeling. Cardiac matrix remodeling is the ultimate result of macrophages proliferation and chemotaxis, neutrophil extravasation, oxidative stress, apoptosis, angiogenesis, fibroblast proliferation and deposition of collagen. Studies show that elevated levels of galectin 3 within atherosclerotic lesions in humans are closely related to the development of a disease itself. With this review, we want to demonstrate the correlation between galectin-3 which is precipitated in atherosclerotic plaque and has an influence on the development of cardiovascular diseases and its role in the prognosis of recovery in cardiac patients.

Modeling of Pressure Pulse Waves in Bypass Grafting*

We investigate the dynamics of a bypass in terms of determining the optimal parameters of shunt operation. The equations that describe the propagation of pressure pulse waves in blood vessels are presented in differential form and in approximate form for the averaged values based on the conservation laws. The correspondence of these forms is shown from the solution of the initial---boundary-value problem for vascular junction. The influence of the parameters such as various diameters, wall thicknesses, and elastic properties of blood vessels on the shunt effectiveness is investigated. In particular, we investigate the influence of the shunt form and junction area, as well as the angle of the shunt connection with the vessel, on the passage of the coronary vessels and blood coagulation. On the basis of the calculations, conclusions about the influence of various parameters on the dynamics of bypass are made.

Model of passage of vessels through the waterway section forming the schedule in the course of its implementation

The model of passage of vessels through a section of the waterway is considered, which independently determines the order of passage of vessels with limited capacity of sections of the track. Such a model will consist of a number of standard algorithmic networks. When composing the schedule in the model, the following preference rules were used: first-come-first-served (that is, if the ship occupied the workplace, this decision is not canceled); The rule of the shortest operation; For the swamps the priority of vessels going downstream (the direction of flow from the source to the drain). An algorithmic network that implements the search for an acceptable schedule must implement the following for conflicting operations: the operation that has started is not interrupted; If several operations simultaneously claim for one workplace (port, reach) and their number is greater than its throughput, then the conflict resolution is carried out in accordance with predefined preference rules or based on the user's decision; If the operation is waiting for the release of the workplace, it does not occupy the resource; The resource is returned immediately after the operation is completed. The considered design of algorithmic networks allows to resolve the conflict, with a simultaneous resource request, to take the resource once, remember that it was received and return it after the end of the operation, then the resource receives a contra-controlling operation for execution. However, the use of this design introduces redundancy into the model, even if it is used only for conflicting operations. The model is presented in the language of algorithmic networks and is implemented in the system of modeling automation KOGNITRON.

Temporal patterns in the soundscape of the shallow waters of a Mediterranean marine protected area.

The study of marine soundscapes is an emerging field of research that contributes important information about biological compositions and environmental conditions. The seasonal and circadian soundscape trends of a marine protected area (MPA) in the Mediterranean Sea have been studied for one year using an autonomous acoustic recorder. Frequencies less than 1 kHz are dominated by noise generated by waves and are louder during the winter; conversely, higher frequencies (4–96 kHz) are dominated by snapping shrimp, which increase their acoustic activity at night during the summer. Fish choruses, below 2 kHz, characterize the soundscape at sunset during the summer. Because there are 13 vessel passages per hour on average, causing acoustic interference with fish choruses 46% of the time, this MPA cannot be considered to be protected from noise. On the basis of the high seasonal variability of the soundscape components, this study proposes a one-year acoustic monitoring protocol using the soundscape methodology approach and discusses the concept of MPA size.

PENEGAKAN HUKUM DI KAWASAN ALUR LAUT KEPULAUAN INDONESIA (ALKI) MENURUT KONSEPSI HUKUM INTERNASIONAL DAN HUKUM NASIONAL INDONESIA

Indonesia is an archipelago consisting of 17,504 islands with the second longest coastline in the world after Canada. Indonesian territory that stretches from Sabang to Merauke composed of 1/3 and 2/3 of the ocean and the mainland after Indonesia ratified UNCLOS in 1982. Based on Law No. 17 of 1985, the extent to 7.9 million km2 comprising of 2 million km2 of land and 5.9 million km2 of ocean. Because Indonesia has good sea area that is subject to the sovereignty and are subject to or falls below the rights and territorial region. In addition to have ratified the Convention on the Law of the Sea 1982 (UNCLOS) Indonesia has also been transformed into Law No. 6 of 1996 and the subsequent Indonesian Government Regulation No. 37 of 2002 on the rights and obligations of foreign ships and aircraft in exercising the right of archipelagic sea lanes passage through archipelagic sea lanes set. Government Regulation No. 38 of 2002 also enhance the rules on listing Baselines of Indonesia where the establishment of ALKI also based on Law No. 17 of 1985 in addition to the Law No. 43 Year 2008 on the territory of the State as well as for guidance in enforcing the law in the territory of the Republic of Indonesia. Importance of the sea in the relations between nations led to the important role of international maritime law, because of the law, among others define the limits of state sovereignty coastal or island states in managing and utilizing sea space especially sea area under the sovereignty such as the territorial sea and archipelagic waters, Archilepagic Sea island nation is the right to give a right of passage for vessels in exercising the right of archipelagic sea lanes passage through predefined. In addition to the island nation that has the right to ensure the safety of crossing ALK passer, passer also have rights and obligations if doing track in the archipelagic sea lane, while respecting the legal provisions in force nationally in a State.

Simulation of electricity generation by marine current turbines at Istanbul Bosphorus Strait

In this work, several simulations and analyses are carried out to investigate the feasibility of generating electricity from underwater sea currents at Istanbul Bosphorus Strait. Bosphorus is a natural canal which forms a border between Europe and Asia by connecting Black Sea and Marmara Sea. The differences in elevation and salinity ratios between these two seas cause strong marine currents. Depending on the morphology of the canal the speed of the flow varies and at some specific locations the energy intensity reaches to sufficient levels where electricity generation by marine current turbines becomes economically feasible.In this study, several simulations are performed for a 10 MW marine turbine farm/cluster whose location is selected by taking into account several factors such as the canal morphology, current speed and passage of vessels. 360 different simulations are performed for 15 different virtual sea states. Similarly, 8 different configurations are analyzed in order to find the optimum spacing between the turbines. Considering the spatial variations in the current speed within the selected region, the analyses are performed for three different flow speeds corresponding to ±10% change in the average value. For each simulation the annual energy yield and cluster efficiency are calculated.

Harbour porpoises react to low levels of high frequency vessel noise.

Cetaceans rely critically on sound for navigation, foraging and communication and are therefore potentially affected by increasing noise levels from human activities at sea. Shipping is the main contributor of anthropogenic noise underwater, but studies of shipping noise effects have primarily considered baleen whales due to their good hearing at low frequencies, where ships produce most noise power. Conversely, the possible effects of vessel noise on small toothed whales have been largely ignored due to their poor low-frequency hearing. Prompted by recent findings of energy at medium- to high-frequencies in vessel noise, we conducted an exposure study where the behaviour of four porpoises (Phocoena phocoena) in a net-pen was logged while they were exposed to 133 vessel passages. Using a multivariate generalised linear mixed-effects model, we show that low levels of high frequency components in vessel noise elicit strong, stereotyped behavioural responses in porpoises. Such low levels will routinely be experienced by porpoises in the wild at ranges of more than 1000 meters from vessels, suggesting that vessel noise is a, so far, largely overlooked, but substantial source of disturbance in shallow water areas with high densities of both porpoises and vessels.

Imaging of peritoneal ligaments by endoscopic ultrasound (with videos).

Double layered peritoneal folds or ligaments act as conduits for the passage of blood vessels in intraperitoneal organs and also provide a pathway for the spread of disease. It is difficult to identify these normal peritoneal folds at imaging. Computed tomography is the most common imaging modality used to detect diseases of the peritoneum. The ultrasound (US) has been also used for evaluation of diseases involving ligaments. Endoscopic ultrasound (EUS) is being increasingly used both for diagnostic and interventional purposes in abdomen. In this article, we have described the normal EUS anatomy of the peritoneal ligaments.

Typification of vessel-induced waves and their interaction with different bank types, including management implications for river restoration projects

Restoration projects often aim to initiate side erosion processes in order to improve the ecological situation, leading to banks of gentle slopes which positively affect biotic habitats. However, within navigable reaches such measures have to be planned under consideration of the impact of vessel-generated waves on YOY-fish. Hence an extensive study was conducted at different bank types to analyze and describe waves, induced by passing vessels. A high resolution wave gauge was exposed, to obtain wave data of different vessel types over a broad discharge range. Simultaneously vessel passage was recorded using an automatic identification system. Attributed to the ships, different wave types could be distinguished and their specific parameters (e.g., wave height) were described. Additionally we analyzed by which of these parameters wave height is primarily affected. For passenger ships a speed reduction of 5 km h−1 results in a reduction of wave height of 14 cm at the Danube. A morphological analysis was accomplished to identify habitat loss and shift of the water’s edge based on ship induced maximum drawdown. Habitat loss, expressed as retrogression of the water’s edge, ranged between 0.88 and 35 m for the highest drawdown recorded.

Imaging of peritoneal ligament by endoscopic ultrasound

Double layered peritoneal folds, variously named as ligaments, omenta and mesenteries connect the intraperitoneal organs to the abdominal wall. Some of these ligaments contain blood vessels and lymph nodes while others are avascular. The peritoneal folds not only act as conduits for the passage of blood vessels from the retroperitoneum to reach intraperitoneal organs, but also provide a pathway for the spread of disease processes. It is difficult to identify these normal peritoneal folds at imaging. Computed tomography is the most common imaging modality used to detect diseases of the peritoneum to fully delineate peritoneal anatomy and the extent of disease. The endoscopic ultrasound (EUS) can be used to image peritoneal ligaments with the advantage of lack of ionizing radiation and lower cost. Though EUS is being increasingly used both for diagnostic and interventional purposes in the abdomen, it has not been used to assess the peritoneal ligaments till now. We did this study in 50 patients using linear echo endoscope to delineate various peritoneal ligaments. The technique of evaluation of ligament has been described in this review. The peritoneal ligaments can be delineated with accuracy by EUS.

Lateralising paraumbilical medial row perforators: Dangers and pitfalls in DIEP FLAP planning: A systematic review of 1116 DIEP flaps

The DIEP flap remains the gold standard for autologous breast reconstruction. Recently, the 'perforasome concept' has advanced our understanding of DIEP flap physiology and planning. This study highlights a patient sub-population that produces anomalies to the perforasome hypothesis: those with paramedian, paraumbilical perforators. Operation notes and pre-operative CT angiograms from 1116 consecutive DIEP flaps were reviewed retrospectively. Patients with paramedian, paraumbilical perforators (n = 153) were contrasted against a control group whose perforators were not paraumbilical (n = 963). Further sub-group analysis was performed within the study group, comparing paraumbilical perforators that held a lateral course within the flap (n = 25) versus those that held a medial course (n = 128). Rates of post-operative DIEP flap partial necrosis was greater in the study population compared with the control group (6.54% vs. 3% p = 0.032). When analysis was made contrasting paraumbilical perforators that held a lateral course in the flap versus perforators that held a median course, flap necrosis was significantly greater in those with a lateral course (24% vs. 3.13%). The perforasome concept has improved our understanding of perfusion from perforators in DIEP flaps. However when the umbilicus presents a physical barrier to blood vessel passage resulting in lateralizing paraumbilical medial row perforators it appears an exception to the "perforasome" rule. Our experience suggests that when a paraumbilical perforator is harvested, a hemi-flap is safe but caution should be exercised when further volume is needed from the contralateral side.

Mixed-methods analytic approach for determining potential impacts of vessel noise on sperm whale click behavior.

The Gulf of Mexico is a center of marine activities from seismic exploration to shipping, drilling, platform installation, lightering, and construction, among others. This analysis explored whether sperm whales respond to the passage of vessels using changes in total number of clicks during vessel passages as a proxy for potential variation in behavior. The data for this analysis were collected in 2001 as part of a larger Littoral Acoustic Demonstration Center project using the Environmental Acoustics Recording System buoys. These buoys were bottom moored, autonomous, and self-recording systems consisting of an omni-directional hydrophone and instrument package. Data from 36 days of continuous acoustic monitoring were recorded at a sampling rate of 11.725 kHz, and produced reliable recordings from 5 Hz to ∼5.8 kHz. Multiple preparatory steps were executed including calibration of an automatic click detector. Results indicate a significant decrease (32%) in the number of clicks detected as a ship approached an area. There were also significantly fewer clicks detected after the vessel passed than before (23%).

Distribution and abundance of fin whales (&lt;i&gt;Balaenoptera physalus&lt;/i&gt;) in the Northeast and Central Atlantic as inferred from the North Atlantic Sightings Surveys 1987-2001

North Atlantic Sightings Surveys (NASS) is a series of large scale international cetacean line transect surveys, conducted in 1987, 1989, 1995 and 2001, that covered a large part of the central and eastern North Atlantic. Target species were fin (Balaenoptera physalus), common minke (B. acutorostrata), pilot (Globicephala melas) and sei (B. borealis) whales. Here we present new estimates of abundance for fin whales from the 2 most recent surveys and analysis of trends throughout the survey period. Fin whales were found in highest densities in the Irminger Sea between Iceland and Greenland. Abundance of fin whales in the survey area of the Icelandic and Faroese vessels (Central North Atlantic) was estimated as 19,672 (95% C.I. 12,083-28,986) animals in 1995 and 24,887 (95% C.I. 18,186-30,214) in 2001. The estimates are negatively biased because of whales diving during the passage of vessels, and whales being missed by observers, but these and other potential biases are likely small for this species. The abundance of fin whales increased significantly over the survey period. For all areas combined the estimated annual growth rate was 4%. An estimated annual increase of 10% in the area between Iceland and Greenland was responsible for most of this overall increase in numbers of fin whales in the area. Although high, the estimated rates of increase are not out of bounds of biological plausibility and can thus be viewed as recovery of a depleted population. However, the apparent pattern of population growth and the whaling history in the area indicate that fin whales made a significant recovery during the first half of the 20th century and that the recent observed high growth rates cannot be explained solely by recovery after overexploitation.

Examining thin layer cap behaviour in a freshwater industrial harbour

A sediment remediation project in Hamilton Harbour, Lake Ontario, Canada, proposes to use a thin layer cap for managing residual contamination from dredging as well as areas of marginal contamination not included in the dredge plan. Bottom shear stress (BSS) from weather, as well as propeller wash, have the potential to severely erode thin layer caps. The proposed thin layer cap was examined with respect to the BSS expected in Hamilton Harbour over a 6-month period. BSS from vessels was estimated using published equations and BSS from weather using the MIKE 3 model. Critical shear stress for the capping sand was estimated using established equations and an annular flume. Estimated BSS from marine vessels was found to exceed the critical shear stress in most cases. However, the extent of impact was difficult to determine and was mitigated to some extent by short vessel passage times, slightly differing routes and further sediment movement caused by weather. The average estimated BSS from weather for the study period was found to be below the critical shear stress for the capping sand, but the maximum BSS exceeded for a small area of the site. Apart from the shipping routes, the majority of the capping area should remain well below the critical shear stress. However, consideration of a larger grain size of capping material for the shallow areas should be considered. This would be of value for future storm conditions which might exceed what was experienced during the 6-month study period.

Comprehensive scenario analysis for mitigation of risks of the maritime traffic in the Strait of Istanbul

In this paper, the results of a scenario analysis are presented using the models developed by the authors in their prior work. Therein an aggregate risk-simulation model of the maritime traffic in the Strait of Istanbul was developed giving consideration to traffic rules, vessel profiles, pilotage services, meteorological, geographical conditions, and vessel scheduling. A risk assessment was carried out by incorporating a probabilistic accident risk model into the simulation model to establish a baseline level of risk. Herein, 16 scenarios are described as modifications of the baseline scenario for the purpose of studying maritime risk mitigation in this geographic context. We have evaluated the impact of several factors such as vessel arrival rates, vessel pursuit distances, number of pilots, local traffic density, and vessel scheduling practices such as the single-lane traffic regime start time on safety risks. We also present a discussion on the impact of each factor on vessel passages and waiting times at both entrances of the Strait. We conclude with risk mitigation recommendations that reduce both risk and waiting times, and thus can be considered ‘win-win’ from both an operational and risk reduction perspective.