Source Vessel Research Articles

The Behavioural Response of Humpback Whales (Megaptera novaeangliae) to a 20 Cubic Inch Air Gun

Seismic surveys are widely used for exploration for oil and gas deposits below the sea floor. Despite concern they may have an impact on whale behaviour, our knowledge of marine mammal responses is limited. In the first of a series of experiments (the last one involving a full seismic array), this study tested the response of migrating humpback whale (Megaptera novaeangliae) groups to a 20 cubic inch air gun. Experiments were carried out during the southward migration of humpback whales along the east coast of Australia. Groups of whales were focally followed from land stations and/or small boats with observations before, during, and after exposure to a vessel towing the air gun. The source vessel moved either eastwards across the, migratory flow or northwards into the migratory flow In total, there were 18 control trials (where the source vessel ran the compressor and towed the air gun without it firing; n = 35 whale groups) and 16 active trials (where the air gun was firing every 11 s; a = 32 whale groups). The air gun source level was 199 dB re 1 mu Pa(2.)s (Sound Exposure Level [SEC]) at 1 m, and SELs received by the whales varied from 105 to 156 dB re 1 mu Pa(2.)s (modal value 128 dB re mu Pa(2.)s) for SELs at least 10 dB above the background noise (measured as dB re 1 mu Pa). Other baseline groups were focal followed when there was no source vessel in the area (n = 25). Results suggested that humpback whale, groups responded by decreasing both dive time and speed of southwards movement though the response magnitude was not found to be related to the proximity of the source vessel, the received level of the air gun, the tow path direction, or the exposure time, within the during phase. There was no evidence of orientation of the groups towards, or away from, the source vessel in the during phase. Interestingly, this behavioural response was found in the control trials as well as the active trials suggesting a response to the source vessel.

Calf perforator flaps: first choice for oral cavity reconstruction

Introduction: Calf perforator flaps are emerging as a popular choice in H&N reconstruction due to their favourable donor site morbidity. There are multiple source vessels in this region – the medial sural artery (MSAP) flap is the most commonly used. We document our clinical experience using calf perforator flaps in oral cavity reconstruction. In addition, we performed a cadaveric dissection study to determine predictability of perforator topography.

Simultaneous Reconstruction of Forefoot and Hindfoot Defects with a Thoracodorsal-Axis Chimeric Flap.

Simultaneous Reconstruction of Forefoot and Hindfoot Defects with a Thoracodorsal-Axis Chimeric Flap.

Source separation for simultaneous towed-streamer marine acquisition — A compressed sensing approach

Simultaneous marine acquisition is an economic way to sample seismic data and speed up acquisition, wherein single or multiple source vessels fire sources at near-simultaneous or slightly random times, resulting in overlapping shot records. The current paradigm for simultaneous towed-streamer marine acquisition incorporates “low variability” in source firing times, i.e., [Formula: see text] or 2 s because the sources and receivers are moving. This results in a low degree of randomness in simultaneous data, which is challenging to separate (into its constituent sources) using compressed-sensing-based separation techniques because randomization is key to successful recovery via compressed sensing. We have addressed the challenge of source separation for simultaneous towed-streamer acquisitions via two compressed-sensing-based approaches, i.e., sparsity promotion and rank minimization. We have evaluated the performance of the sparsity-promotion- and rank-minimization-based techniques by simulating two simultaneous towed-streamer acquisition scenarios, i.e., over/under and simultaneous long offset. A field data example from the Gulf of Suez for the over/under acquisition scenario was also developed. We observed that the proposed approaches gave good and comparable recovery qualities of the separated sources, but the rank-minimization technique outperformed the sparsity-promoting technique in terms of the computational time and memory. We also compared these two techniques with the normal-moveout-based median-filtering-type approach, which had comparable results.

Upper Medial Tigh Perforator Flap in the Lower Extremity Reconstruction

INTRODUCTION: The medial circumflex femoral perforator flap was named according to the convention of the Gent consensus for perforator flap nomenclature1, on the basis of its customary source vessel. It is a true perforator flap, because intramuscular dissection of the gracilis musculocutaneous perforators is necessary to ensure inflow to the cutaneous flap2.In this report, we present upper medial tigh perforator flap (gracilis perforator flap) in a hori- zontal (transverse to the gracilis muscle) manner based on any reliable perforators from the upper medial thigh. MATERIALS AND METHODS: All of four patient have lower extremity soft tissue defects due to traumatic injuries. There were 1 female patients and 3 male patients. The average age of the patients was 23 years (range, 6 to 35 years). All flaps were raised subfascially in a free-style flap fashion. RESULTS: All perforators were originated from the medial circumflex femoral artery and the perforators were musculocutaneous. Mean flap diameter were 13x6,5cm. In one patient, gracilis muscle also included in flap design and upper medial tigh perforator based skin island also harvested. All flaps were survived and donor sites were closed primarily (Figure 1).Figure 1: Preoperative view of patient (A), the view of harvested upper medial tigh perforator flap (B;C), Postoperative view of patient (D).CONCLUSION: The major advantages of this flap were noted as its donor site that allowed surgeon concealing scar to gluteal creases. However, its major disadvantages was inconsistent perforator position and we believe that free style free flap approach can solve this advantages in experienced hands. The flap can obtain reasonable size, well-hidden scar, function, good pliability.

Perforator chimerism for the reconstruction of complex defects: A new chimeric free flap classification system

Complex defects present structural and functional challenges to reconstructive surgeons. When compared to multiple free flaps or staged reconstruction, the use of chimeric flaps to reconstruct such defects have many advantages such as reduced number of operative procedures and donor site morbidity as well as preservation of recipient vessels. With increased popularity of perforator flaps, chimeric flaps' harvest and design has benefited from 'perforator concept' towards more versatile and better reconstruction solutions. This article discusses perforator based chimeric flaps and presents a practice based classification system that incorporates the perforator flap concept into "Perforator Chimerism". The authors analyzed a variety of chimeric patterns used in 31 consecutive cases to present illustrative case series and their new classification system. Accordingly, chimeric flaps are classified into four types. Type I: Classical Chimerism, Type II: Anastomotic Chimerism, Type III: Perforator Chimerism and Type IV Mixed Chimerism. Types I on specific source vessel anatomy whilst Type II requires microvascular anastomosis to create the chimeric reconstructive solution. Type III chimeric flaps utilizes the perforator concept to raise two components of tissues without microvascular anastomosis between them. Type IV chimeric flaps are mixed type flaps comprising any combination of Types I to III. Incorporation of the perforator concept in planning and designing chimeric flaps has allowed safe, effective and aesthetically superior reconstruction of complex defects. The new classification system aids reconstructive surgeons and trainees to understand chimeric flaps design, facilitating effective incorporation of this important reconstructive technique into the armamentarium of the reconstruction toolbox.

Bimodal Treatment of a Huge Hypervascular Neurofibroma on the Groin.

Bimodal Treatment of a Huge Hypervascular Neurofibroma on the Groin.

Influence of the source size on domino effect risk caused by fragments

We developed the movement equations for fragments with the size of the bursting vessel. The ground distributions of fragments, the probability of impact between the fragments and the target, the rupture probability of the impacted target, and the domino effect risk caused by fragments were investigated for different source types and sizes using Monte-Carlo simulations. The distribution of fragments from the lower half of the source vessels onto the ground was non-zero, that is, it is probable that the fragments would hit the target vessel close to the source. The relative difference of impact probability is larger than 10% when the target vessel is within eight times the source diameter for the three types of sources considered. The proportion of impacts of fragments from the lower part of the source to total impact decreased with distance, while that for fragments from the upper part increased. The proportion of upper and lower parts is equal for distance approximately five times the source diameter. The source size needs to be considered along with the distance from the source to the target when less than approximately 14 times the source diameter. Its effect on impact probability and domino effect risk was significant. The rupture probability of the target depended very little on the source size.

Assembly and gap management strategy for the ITER NBI vessel passive magnetic shield

The neutral beam system for ITER consists of two heating and current drive neutral ion beam injectors (HNB) and a diagnostic neutral beam (DNB) injector. The proposed physical plant layout allows a possible third HNB injector to be installed later. The HNB Passive Magnetic Shield (PMS) works in conjunction with the active compensation/correction coils to limit the magnetic field inside the Beam Line Vessel (BLV), Beam Source Vessel (BSV), High Voltage Bushing (HVB) and Transmission Line (TL) elbow to acceptable levels that do not interfere with the operation of the HNB components. This paper describes the current design of the PMS, having had only minor modifications since the preliminary design review (PDR) held in IO in April 2013, and the assembly strategy for the vessel PMS.

Field-wide implementation of time and distance separated source techniques on a 3D OBC survey offshore Abu Dhabi, UAE

ADMA-OPCO undertook a large 3D-4C OBC (ocean bottom cable) survey over an oil and gas field offshore Abu Dhabi, UAE. The survey was designed to acquire a high-fold dataset having wide azimuth and long offset sampling. The survey utilized, for the first time, two simultaneous source techniques so-called DS3 (Distance Separated Simultaneous Shooting) and MSS (Managed Spread and Sources) to enhance survey productivity and minimize HSE exposure in the field. DS3 and MSS involve two source vessels operating simultaneously while maintaining predetermined separations among shots in time and space to produce records with minimal contamination of seismic interferences. Unlike land surveys, these two techniques had not previously been applied to an OBC survey. To ensure adequacy of the techniques, the acquisition started with 2D tests prior to full-field implementation. With DS3 and MSS, the 3D survey yielded remarkable enhancement of survey productivity as compared to conventional single source vessel configuration. DS3 and MSS along with proper temporal and spatial source vessel separations enable recorded data to be handled as if acquired by non-simultaneous source survey.

“NACsomes”: A new classification system of the blood supply to the nipple areola complex (NAC) based on diagnostic breast MRI exams

Breast MRIs have become increasingly common in breast cancer work-up. Previously obtained breast MRIs may facilitate oncoplastic surgery by delineating the blood supply to the nipple-areola complex (NAC). The aim of this study was to identify and classify the invivo blood supply to the NAC using breast MRI exams. Breast MRIs obtained over a one-year period were retrospectively reviewed. Patients with negative MRI findings (BI-RADS category 1) were included; patients with diagnoses of breast cancer or previous breast surgery were excluded. Twenty-six patients were evaluated. Dominant blood supply was determined by maximum filling at 70s post-contrast. Blood supply to the NAC was classified into five anatomic zones: medial (type I), lateral (type II), central (type III), inferior (type IV) and superior (type V). Patient age ranged from 33 to 70 years. Fifty-two breasts were evaluated and 80 source vessels were identified (37 right, 43 left). Twenty-eight breasts had type I only blood supply, 22 breasts had multi-zone blood supply (type I+II, n=20; type I+III n=2), one breast had type II only blood supply, and a single breast had type III only blood supply. Anatomic symmetry was observed in 96% of patients. This study utilized MRI to evaluate invivo vascular anatomy of the NAC, classify NAC perfusion ("NACsomes"), and assess vascular symmetry between breasts. Superomedial source vessels supplying the NAC were predominant. Preoperatively defining NAC blood supply may aid planning for oncoplastic procedures.

Perforator Flap versus Conventional Flap.

The introduction of perforator flaps represented a significant advance in microsurgical reconstruction. However, confusion has developed due to the erroneous belief that perforator flaps are different from conventional flaps. The concept of the perforator is not new, but is an idea that evolved from the conventional flap. In fact, some of the flaps used by microsurgeons were perforator flaps. The only difference is the anatomical level of the blood vessels involved; the perforator concept is focused on the distal circulation, so-called 'perforator'. Therefore, thinner sections of tissue can be taken from the conventional donor sites of myocutaneous flaps. With the use of perforators, there are no longer "flap of choice" for specific reconstructions, because conventional donor sites have become universal donor sites, enabling the harvesting of a variety of flaps. Moreover, depending on the surgeon's ability, any flap can be utilized as a perforator-based island flap whose source vessel has been completely preserved. Therefore, tissues can be efficiently customized and tailored into any configuration required for reconstruction. The application of perforator flap technique enables more precise dissection, and allows more selective harvesting of thinner flaps, which will expand options in reconstructive surgery. No doubt the technique will continue to evolve.

Successful Deep Inferior Epigastric Perforator Flap Breast Reconstruction Following Prior Deep Inferior Epigastric Source Vessel Ligation

INTRODUCTION: Deep inferior epigastric perforator (DIEP) flaps represent an excellent method of breast reconstruction. Its success is predicated upon careful dissection of the dominant deep inferior epigastric (DIE) perforators and the patency of its associated source vessels. Prior ligation of the DIE vessels would thereby negatively impact DIEP flap harvest. If collateral branches maintain the patency of these source vessels, DIEP flap harvest may still be possible. We have successfully performed two bilateral DIEP breast reconstructions following prior ligation of the DIE source vessels. METHODS: A retrospective review of two cases of DIEP breast reconstruction was performed following prior ligation of the DIE source vessels. The characteristics and findings in these specific cases were analyzed. RESULTS: The first patient had multiple failed attempts at bilateral breast reconstruction using implants and latissimus flaps. The right chest wall had been previously radiated. A bilateral salpingo-oophorectomy had been performed for ovarian carcinoma via a Pfannenstiel incision. The DIE source vessels were found to be ligated and transected bilaterally from her gynecologic procedure near their origin at the iliac vessels. Although diminutive in size, intercostal collaterals near the hemoclips maintained source vessel patency and bilateral DIEP reconstruction was completed. The second patient had prior latissimus-based breast reconstructions with submuscular implants. This was complicated by a right-sided infected seroma and bilateral implant capsular contracture. She had undergone a prior delay procedure for possible pedicled TRAM flap reconstruction but did not wish to sacrifice her rectus muscles. CT angiography was performed of the abdomen and pelvis for possible gluteal artery perforator flap reconstruction. Despite clips on the DIE vessels near their origin, they appeared patent and of suitable caliber with sufficient length for bilateral breast reconstruction. Bilateral DIEP breast reconstruction was successfully performed without any associated complications. CONCLUSION: Successful DIEP flap reconstruction depends upon the patency of the DIE source vessels and sufficient perforators to maintain normal flap perfusion. Prior ligation of the DIE source vessels would therefore negatively impact successful flap harvest. If, however, collateral vessels maintain the patency of these source vessels, DIEP flap reconstruction can thereby be carried out successfully as demonstrated by these two cases. Radiologic imaging can aid in identifying such cases.

Anatomy of anteromedial thigh perforators: CT-angiography study.

The anatomy of perforator for anteromedial thigh (AMT) flap is a very much-debated issue. In this article, we report AMT perforator vascular anatomy by CT-Angiography (CTA) evaluation of 68 consecutive healthy thighs. Perforators emergence, caliber, length, course, and source vessel in the central three fifth of the thigh were studied by a virtual coordinate system. A mean 4.94 ± 1.75 perforators per thigh (average length, 2.6 ± 0.99 cm) from superficial femoral artery (SFA) were found, emerging medial and lateral to sartorius muscle. A mean 0.4 ± 0.74 perforators per thigh (average length, 2.45 ± 0.97 cm) branched from rectus femoris artery, of which 80% were emerging lateral to sartorius muscle. A mean 0.62 ± 0.91 perforators per thigh (average length, 3.1 ± 1.23 cm) branched from an unnamed branch of SFA, of which 88% were emerging lateral to the sartorius muscle. Perforators' calibre was inferior to 1-5 mm in 177 perforators (51.6%), between 1.5 and 2 mm in 159 (46.7%), and over 2 mm in 7 (2%). The findings from this study show that AMT region is plenty of reliable perforators with overlapping fascial emergence but branching from three different source arteries.

Variation in harbour porpoise activity in response to seismic survey noise.

Animals exposed to anthropogenic disturbance make trade-offs between perceived risk and the cost of leaving disturbed areas. Impact assessments tend to focus on overt behavioural responses leading to displacement, but trade-offs may also impact individual energy budgets through reduced foraging performance. Previous studies found no evidence for broad-scale displacement of harbour porpoises exposed to impulse noise from a 10 day two-dimensional seismic survey. Here, we used an array of passive acoustic loggers coupled with calibrated noise measurements to test whether the seismic survey influenced the activity patterns of porpoises remaining in the area. We showed that the probability of recording a buzz declined by 15% in the ensonified area and was positively related to distance from the source vessel. We also estimated received levels at the hydrophones and characterized the noise response curve. Our results demonstrate how environmental impact assessments can be developed to assess more subtle effects of noise disturbance on activity patterns and foraging efficiency.

Posterior interosseous artery perforator-free flap: Treating intermediate-size hand and foot defects

Ambiguous defects on the hand and foot, especially on the fingers and toes, are still challenging to treat despite achievements in reconstruction. The purpose of this study was to evaluate the use of the posterior interosseous artery perforator flap for resurfacing intermediate-sized defects and provide adequate coverage over tendons and bones. Between October 2008 and March 2013, a total of 19 patients with soft-tissue defects on the hand or foot were treated. Flap elevation, anatomy, and clinical progress were evaluated. All flaps survived and covered the defects, which ranged in area from 12 to 45 cm(2). The freestyle approach was used to harvest the flaps. The average length of the pedicle was 2.5 cm, and the pedicle was harvested without affecting the source vessel. The average diameter of the artery was 0.8 mm, and the average thickness of the flap was 3.5 mm. Anastomosis was performed either end-to-end on the perforator, or end-to-side on deep vessels. No subsequent thinning or surgical flap correction was necessary. Ambulation was allowed at 3 days postsurgery. The donor site was closed primarily to leave an acceptable donor site. A posterior interosseous artery perforator-free flap is a suitable choice for intermediate-size defects that are too large to cover using a local flap or too small for a first-line perforator flap. Up to 45 cm(2) of adequate coverage can be provided using a thin posterior interosseous artery perforator-free flap that does not require additional debulking. The disadvantages of a short pedicle can be overcome using perforator-to-perforator supermicrosurgery.

Practices and Perceptions of Biosand Filter Users in Treating Drinking Water in a Rural District of Zimbabwe

A field survey was conducted in Bindura district of Zimbabwe in January 2012 to evaluate the perceptions and practices of rural households on biosand filters after two years of use. A questionnaire was administered to 33 sampled households during an unannounced visit to solicit information on demography, use of biosand filters and safe water storage. A field kit (Oxfam delAgua) was used to estimate faecal coliforms in 83 water samples drawn from the household source (17), filter-spout (33) and storage vessel (33). Results indicate that biosand filters were structurally intact and operational with a mean treatment efficiency of 95.9±1.4% (n=33) suggesting a high sustained use. Households (n=33) expressed great satisfaction with the use of biosand filters as they got adequate drinking water (90.9%). Households cited improved health (100%), clean water (100%); good taste (100%) and ease of use (90.9%) as perceived benefits of using the biosand filter. The mean faecal coliform level of biosand filter-treated water (3.2±1.4cfu/100ml) was significantly lower than that of source water (37.1±8.9cfu/100ml) (p<0.05). Biosand filters (78.8%) provided safe drinking water (0cfu/100ml) but were recontaminated (26.9%, n=26) during storage. Poor household hygiene, unrecommended storage methods and withdrawal practices were attributed to recontamination of stored treated water.

Influence of the Cylindrical Source Size on Impact Probability Caused by Fragments

The movement equations of fragment with the size of the bursting vessel were developed. The ground distributions of fragments, and the probability of impact between the fragments and the target were investigated in consideration of cylindrical source size using Monte-Carlo simulations. The results showed that the distributions of the fragments from the lower half of the source vessels on the ground were larger than 0, it was simply probable that the fragments would hit the target around the source. The relative deviation of impact probability would be larger than 10% when the target vessel was located in the distance less than 8 times of the cylindrical source diameter. The proportion of impact probability of lower part of the source to the total impact probability decreased with the distance, but that of upper part increased. The proportion of upper and lower parts would be equal if the distance was about 5 times of the source diameter. The source size should be considered with the distance from the source to the target less than 14 times of the source diameter, and its effect on the impact probability was significant.

Vascular malformation of upper lip and left eye: A case report with nomenclature review

The term Hemangioma though traditional yet until date is the most frequently misused terminology by many radiologists for reporting all variety of vascular anomalies. Mulliken in 1982 developed a thorough study and classification, based on the cellular kinetics of anomalous vessels, and includes two entities:Hemangioma/vascular tumor andVascular malformations (VM).However, the continuous use of an older nomenclature causes confusion resulting in inaccurate diagnoses and hence potential mismanagement. The management of these abnormalities presents both a diagnostic and therapeutic challenges and they expand to include the preservation of both functional concerns and cosmetic appearance of the affected structures. Further the application of more advanced diagnostic techniques, all gives the precise localization of the source vessel allowing for making excision and reconstructive planning more accurate and satisfactory. Here we present a case of a 16-year-boy diagnosed with low flow VM affecting upper lip causing and left eye.

Three-dimensional primary acoustic field characterization for a seismic airgun array

The Littoral Acoustic Demonstration Center conducted the Source Characterization Study in 2007 (SCS07) to measure the 3-D acoustic field of a seismic airgun array in the Gulf of Mexico. Three moorings with sensitive and desensitized hydrophones at different depths were deployed as well as hydrophones suspended from a ship, while a seismic source vessel shot specified lines. Hydrophone positions were measured. Peak pressures, RMS sound pressure levels (SPL), sound exposure levels, total shot energy spectra, one-third octave band analyses, and source directivity studies are used to characterize the field. Summary results are first calculated for each hydrophone. These are then combined to give isopleths for azimuthal cuts at 0, 45, 90 degrees, etc., for the spatial domain measures. Plots for each solid angle bin give these and frequency measures analyzed versus range. Zero-to-peak pressures directly under the array go from 210 dB for depths less than 200 m down to 195 dB at 1200 m. At 2000 m horizontal range the pressures go from 160 dB near the surface to 175 to 180 dB at 1200 m. RMS SPL is about 5 dB smaller. [Research supported by the Joint Industry Programme through the International Association of Oil and Gas Producers.]