Bayesian submerged oil tracking with SOSim: Inference from field reconnaissance data and fate-transport model output.

When spilled oil collects at depth, questions as to where and when to dispatch response equipment become daunting, because such oil may be invisible by air, and underwater sensing technology is limited in coverage and by underwater visibility. Further, trajectory modeling based on previously recorded flow field data may show mixed results. In this work, the Bayesian model, SOSim, is modified to locate and forecast the movement of submerged oil, with confidence bound, by inferring model parameters based on any available field concentration data and the output of one or more deterministic trajectory models. Novel aspects include specification of a prior likelihood function, and generation of results in 3-D from data in the 2-D density space of the isopycnal layer containing oil. The model is demonstrated versus data collected following the Deepwater Horizon spill. This new inferential modeling approach appears complimentary to deterministic methods when field concentration data are available.

Bayesian sunken oil tracking with SOSim v2: Inference from field and bathymetric data.

Sunken oil is often difficult to detect, and few oil spill models are designed to locate and track such oil. Therefore, the multi-modal Bayesian inferential sunken oil model, SOSim (Subsurface Oil Simulator), was expanded in this work for use during emergency response and damage assessment. Rather than requiring hydrodynamic data as input, SOSim v2 accepts available field concentration data, along with default or custom bathymetric data, for inference of the location and trajectory of sunken oil. Novel aspects include inference based on bathymetry and the Coriolis Effect, by constructing a prior likelihood function from sampled bathymetric data, scaled proportionally with field concentration data. SOSim v2 is demonstrated versus field data on the ITB DBL-152 oil spill in the Gulf of Mexico, with sensitivity analysis. Results suggest that the inferential approach presented can be effective for modeling relatively slow-moving pollutant masses such as sunken oil, when field concentration data are available.

A review on the sinking mechanisms for oil and successful response technologies.

A rise in the shipping of heavier hydrocarbon products increases the potential for an oil to sink after a spill. Further, sunken oil is difficult to locate and recover, and appropriate response technologies depend on the sinking mechanism. In this review, principal sinking mechanisms for oil are described and appropriate response technologies are suggested. Then, models appropriate for tracking sunken oil are compared. Oil may sink as burn residue, microscopic oil-particle aggregates (OPAs) or macroscopic oil-sediment mixtures (OSMs), marine oil snow during a MOSSFA event, or due to its high density. The most common mechanism is by sediment entrainment, and in such scenarios manual recovery has been reported as a successful response option. Among oil tracking models, trajectory models and Bayesian oil search models are compared for sunken oil capabilities. Many oil spill models require hydrodynamic inputs, whereas Bayesian models infer parameters based on available field concentration and bathymetric data.

A model for the estimation of the mixing zone behind large sea vessels.

One of the important tasks associated with reducing the concentration of contaminants in the sea surface layer is the determination of their mixing volume, as of the most active systems for mixing the sea surface layer are sea vessels. The wake of a ship is a highly mixed medium. The study of the wake development over time is important when evaluating the mixing of various pollutants in the wake with neutralizing chemicals. As shown in some previous works, in the wake of a vessel that crosses a contaminated surface, the concentration of harmful impurities decreases to background values; however, the problem of determining the volumetric characteristics of this wake remains. In our work, we propose a relatively simple model for assessing the characteristics of a turbulent wake in the near zone behind a vessel. Based on the actual parameters of the vessels, the parameter F= (penetration depth) / (draft) was calculated, which characterizes the potential mixing effects caused by turbulence in the wake. The proposed simple model can be used, for example, to assess the mixing of oil when it is being bottled, with chemicals, to assess possible scenarios of increasing its dilution.

Improving oil spill trajectory modelling in the Arctic.

As petroleum development and other activities move further north, the potential for oil spills in ice-covered waters is of great concern. As a tool for contingency planning and forecasting during response, oil spill models play a key role. With the development of new, high-resolution coupled ice-ocean models, better predictions of sea ice are becoming available. We have updated the OSCAR oil spill model to use sea-ice velocity and coverage fields from coupled ice-ocean models to improve simulation of oil fate and transport in ice-covered waters. We describe the implementation of oil transport in the presence of ice, and demonstrate the improvement by considering three case studies. We find clear improvement when taking ice velocity from a coupled ice-ocean model into account, compared to a heuristic model that uses surface current and wind velocity. The difference is found to be especially important in a response situation near the marginal ice zone.

A critical review of marine snow in the context of oil spills and oil spill dispersant treatment with focus on the Deepwater Horizon oil spill.

Natural marine snow (NMS) is defined as the "shower" of particle aggregates formed by processes that occur in the world's oceans, consisting of macroscopic aggregates of detritus, living organisms and inorganic matter. Recent studies from the Deepwater Horizon oil spill suggest that marine snow is also formed in association with oil spills and was an important factor for the transport of oil to the seabed. This review summarizes the research and literature on MS, mainly from the DWH oil spill, with a focus on the relation between the use of oil spill dispersants and the formation and fate of oil-related marine snow (ORMS). Studies are still required to determine ORMS processes at oil concentrations as relevant as possible for chemically dispersed oil.

Current status of deepwater oil spill modelling in the Faroe-Shetland Channel, Northeast Atlantic, and future challenges.

As oil reserves in established basins become depleted, exploration and production moves towards relatively unexploited areas, such as deep waters off the continental shelf. The Faroe-Shetland Channel (FSC, NE Atlantic) and adjacent areas have been subject to increased focus by the oil industry. In addition to extreme depths, metocean conditions in this region characterise an environment with high waves and strong winds, strong currents, complex circulation patterns, sharp density gradients, and large small- and mesoscale variability. These conditions pose operational challenges to oil spill response and question the suitability of current oil spill modelling frameworks (oil spill models and their forcing data) to adequately simulate the behaviour of a potential oil spill in the area. This article reviews the state of knowledge relevant to deepwater oil spill modelling for the FSC area and identifies knowledge gaps and research priorities. Our analysis should be relevant to other areas of complex oceanography.

Oil spill response capabilities and technologies for ice-covered Arctic marine waters: A review of recent developments and established practices.

Renewed political and commercial interest in the resources of the Arctic, the reduction in the extent and thickness of sea ice, and the recent failings that led to the Deepwater Horizon oil spill, have prompted industry and its regulatory agencies, governments, local communities and NGOs to look at all aspects of Arctic oil spill countermeasures with fresh eyes. This paper provides an overview of present oil spill response capabilities and technologies for ice-covered waters, as well as under potential future conditions driven by a changing climate. Though not an exhaustive review, we provide the key research results for oil spill response from knowledge accumulated over many decades, including significant review papers that have been prepared as well as results from recent laboratory tests, field programmes and modelling work. The three main areas covered by the review are as follows: oil weathering and modelling; oil detection and monitoring; and oil spill response techniques.

Impact of climate change and seasonal trends on the fate of Arctic oil spills.

We investigated the effects of a warmer climate, and seasonal trends, on the fate of oil spilled in the Arctic. Three well blowout scenarios, two shipping accidents and a pipeline rupture were considered. We used ensembles of numerical simulations, using the OSCAR oil spill model, with environmental data for the periods 2009-2012 and 2050-2053 (representing a warmer future) as inputs to the model. Future atmospheric forcing was based on the IPCC's A1B scenario, with the ocean data generated by the hydrodynamic model SINMOD. We found differences in "typical" outcome of a spill in a warmer future compared to the present, mainly due to a longer season of open water. We have demonstrated that ice cover is extremely important for predicting the fate of an Arctic oil spill, and find that oil spills in a warming climate will in some cases result in greater areal coverage and shoreline exposure.

The significance of dilution in evaluating possible impacts of wastewater discharges from large cruise ships.

In response to public concerns about discharges from large cruise ships, Alaska's Department of Environmental Conservation (ADEC) sampled numerous effluents in the summer of 2000. The data showed that basic marine sanitation device (MSD) technology for black water (sewage) was not performing as expected. Untreated gray water had high levels of conventional pollutants and surprisingly high levels of bacteria. Both black water and gray water discharges sometimes exceeded state water quality standards for toxicants. The state convened a Science Advisory Panel (the Panel) to evaluate impacts associated with cruise ship wastewater discharges. The effluent data received wide media coverage and increased public concerns. Consequently, legislative decisions were made at the State and Federal level, and regulations were imposed before the Panel completed its evaluation. The Panel demonstrated that following the rapid dilution from moving cruise ships, the effluent data from the Summer of 2000 would not have exceeded water quality standards, and environmental effects were not expected.

Subglottic carcinoma: review of a series and characterization of its patterns of spread.

The rarity of primary subglottic malignancies, along with the varied definitions of the anatomic confines of this region, have limited our understanding of the patterns of tumor spread within the subglottis. We conducted a retrospective chart review to analyze clinical and pathologic data in patients with subglottic carcinoma. A pattern of disease progression was identified, which is defined by the cartilaginous laryngeal framework, with the fibroelastic barriers susceptible to tumor invasion. We conclude that although cartilaginous laryngeal structures are preserved until late in the disease course, the ability of tumors to invade the fibroelastic membranes provides them with an insidious means of escape. Specifically, tumor progression occurs primarily within the paraglottic space and extralaryngeal compartments; the potential for mucosal spread is limited. The lack of mucosal disease in patients whose cartilaginous laryngeal structures are intact may present a facade of normality in patients with advanced disease, and perhaps delay the early diagnosis of subglottic malignancies by physical and radiologic examination.

Unknown primary of the head and neck.

The occurrence of metastases to the cervical lymph nodes from an unknown primary tumour is seen in approximately three to six per cent of patients with cervical adenopathy and the primary tumour commonly remains elusive. Single modality treatment is occasionally advocated but combined treatment seems to obtain the best results. A retrospective analysis of patients' charts with unknown primary of the head and neck in the University of Michigan Medical Center was undertaken for the years 1978-1992. Forty-eight records met study criteria and were reviewed. Our series' size and heterogeneity prevents drawing conclusions regarding treatment effectiveness. The majority (67.5 per cent) of our patients were treated by surgery followed by irradiation. Our overall survival rates compare favourably with the general statistics although it should be noted that longer follow-up in our first group of patients may alter our results. Extracapsular spread did not adversely affect survival in our small series of five cases. We discovered six primary sites within one year and three additional cases within four years. The primary site was included in the radiation fields in all instances of squamous cell tumours that were eventually found. It has been suggested than eventual manifestation of the primary site adversely affects prognosis, which is in agreement with our results.

Elevated arginine vasopressin levels in squamous cell cancer of the head and neck.

The reported effectiveness of single tumor markers (TMs) associated with squamous cell cancer of the head and neck ranges from 15% to 71%, with most studies reporting sensitivity no higher than 50%. An increased incidence of the syndrome of inappropriate secretion of antidiuretic hormone or arginine vasopressin (SIADH) in patients with head and neck cancer has been reported. Serum arginine vasopressin (AVP) was studied as a possible TM in these patients. Sixty-three patients with squamous cell carcinoma of the head and neck determined as potentially curable were prospectively evaluated before treatment and compared to 17 patients with apparent cure of head and neck squamous cell cancer who served as controls. Serum AVP levels were obtained and determined by radioimmunoassay in the preoperative period and 1 week postoperatively in 15 patients. Thirty-four patients were staged as T4, 26 as T3, and 3 as T2. Twenty-one (33%) of the 63 patients had no neck involvement. Twenty-four (38%) of 63 patients had elevated serum AVP levels corrected for serum osmolarity. Of the 15 patients evaluated before and after surgery, 8 (53%) had elevated serum AVP levels preoperatively. Of these 8 patients, 3 had reduction in AVP levels and 5 had complete normalization after 1 week. The result obtained for serum AVP do not exceed results of other TMs reported. AVP may also not be as specific as other TMs for cancer of the head and neck. Our group with AVP sampled postoperatively is too small for us to draw conclusions, but reduction of its levels after treatment in all patients may be significant. These preliminary results indicate that further evaluation of AVP during the posttreatment course in a larger number of cases, and perhaps with other TMs as well, is warranted.

Violence in the health care environment.

The rapid rise in the incidence of violence in our society is an increasing risk to all Americans. As violence increases for our patients and in society around us, it becomes an ever greater problem for all health care personnel. The number of threats and violent acts against health care providers has been steadily increasing in recent years. The most effective method of managing violence is to prevent it. A critical step in prevention is in differentiating between an angry individual and a potentially violent individual based on his or her speech, appearance, and behavior. Heightened security and changes in the medical environment are additional ways of preventing violence. Management of a violent incident includes early recognition, de-escalation techniques, and a collaborative effort with security personnel.

Recurrent cytogenetic abnormalities in squamous cell carcinomas of the head and neck region.

We characterized the breakpoints, gains, and losses of chromosome material in squamous cell carcinomas of the head and neck region from 29 patients. Cell lines were karyotyped in 1/3 of cases, direct preparations or early in vitro harvests in 1/3, and both in 1/3 of cases. GTG-banding was employed in all cases, as were C-banding and RBG- and AgNOR-staining in most. Some tumors were near-diploid and others near-tetraploid, but many had mixed populations, with diploid, tetraploid, and octoploid subclones representing essentially the same karyotypic pattern. The most frequent changes were deletions. Losses affecting 3p13-p24, 5q12-q23, 8p22-p23, 9p21-p24, and 18q22-q23 ranged in frequency from 40% to 60% of tumors. Loss of the short arm of the inactive X occurred in 70% of tumors from female patients, and loss or rearrangement of the Y occurred in 74% of tumors from male patients. Loss of 18q appeared to be associated with short survival, as did the presence of multiple deletions. There was gain (2-5 extra copies) of 3q21-qter, 5p, 7p, 8q, and 11q13-q23 in 28-38% of tumors. Three tumors had an hsr involving 11q13-q21. Gain of material at 11q13 is postulated to be associated with amplification of the PRADI/CCND gene at that locus. A translocation between proximal 1p and either an acrocentric short arm or proximal 8p or 9p was observed in squamous cell carcinomas of the head and neck region but not in female genital tract tumors. No other abnormalities appeared to be site specific, suggesting a pattern of genetic evolution in squamous cell carcinoma that is independent of anatomic site.

Olfactory neuroblastoma: the results of modern treatment approaches at the University of Michigan.

A retrospective study was undertaken to review patterns of treatment and survival for patients with olfactory neuroblastomas at the University of Michigan since the introduction of craniofacial resection in the late 1970s. Recent results were compared to previous reports. Disease-free and overall survival for patients with Kadish stage B tumors were unchanged from prior years. Improvement in both disease-free intervals and overall survival was evident for patients with stage C tumors. Interestingly, in two patients with "unresectable" local disease, complete responses to induction chemotherapy followed by radiotherapy were noted.

Serial studies of autologous antibody reactivity to squamous cell carcinoma of the head and neck.

In previous studies we evaluated the incidence and specificity of autologous antibody reactivity against squamous cell carcinoma of the head and neck (SCCHN). We were able to demonstrate that autologous antibody reactivity is present in native sera but was usually of too low a titer to allow further analysis. Dissociation of immune complexes by acidification and ultrafiltration of serum augmented autologous antibody reactivity in nine out of nine autologous systems tested. Native antibody and antibody derived from immune complexes produced by the host and reactive with autologous tumor cells may be directed against physiologically relevant antigens. Therefore, correlations of antibody titers with clinical course may provide insight into the nature of the host response to cancer. In the present analysis, serological studies of six patients with SCCHN were performed with serum samples obtained over many months. Results of serial serological assays were correlated to tumor progression and clinical course. Fluctuations in autologous antibody reactivity were noted over time. In four cases, rises in autologous antibody titers preceded the clinical diagnosis of recurrence by several months. Drops in autologous antibody reactivity were noted in two cases following surgery or radiation therapy. In two cases of long-term survivors, no correlation between antibody reactivity and clinical course was noted. Specificity analysis of the six autologous systems demonstrated reactivity against autologous and allogeneic SCCHN as well as melanoma cell lines. These sera did not react with glioma, neuroblastoma, renal cell, breast, bladder and colon carcinoma cell lines nor with fetal calf serum, pooled lymphocytes, red blood cells and platelets. Autologous serial serological studies may provide a means by which to evaluate the host/tumor relationship in patients with SCCHN.

Incidence of serum antibody reactivity to autologous head and neck cancer cell lines and augmentation of antibody reactivity following acid dissociation and ultrafiltration.

Serum antibody reactivity to squamous cell carcinoma of the head and neck (SCCHN) was evaluated in 41 autologous serum-tumor cell line combinations using the protein A hemadsorption assay. Autologous antibody reactivity (median titer of 1:4) was detected in sera from 24 of the patients tested. In 10 cases autologous antibody reactivity could be detected only in undiluted serum precluding further analysis. Analysis of higher titer sera from one patient revealed antibodies that define an antigen expressed on autologous tumor cells cultured from both the primary tumor (UM-SCC-17A) and from a metastasis (UM-SCC-17B). Absorption analysis showed that this antigen was also expressed on 6 of 10 allogeneic SCCHN cell lines but not on autologous fibroblasts or on allogeneic melanoma cell lines. Due to the low titer of autologous antibody reactivity in most sera, we sought to determine if dissociation of immune complexes through acidification and ultrafiltration of serum might enhance detectable antibody reactivity as has been done in previous studies in melanoma. Twelve serum samples from eight patients were subjected to acid dissociation and ultrafiltration (AD-U). Only six of the untreated sera had detectable antibody reactivity against the autologous SCCHN cell line whereas following AD-U all 12 sera had enhanced IgG reactivity against autologous SCCHN. Specificity analysis of one serum sample after dissociation revealed that the antibody detected an antigen common to SCCHN cell lines as well as melanoma, glioma, renal, and colon carcinoma cell lines. Circulating immune complexes may provide a reservoir of antibody with potential diagnostic and therapeutic applications.

Clinical nasal obstruction and objective respiratory mode determination.

Nasal obstruction represents a considerable portion of the symptoms addressed by the otolaryngologist. It has received widespread interest in the orthodontic literature as well, because of the presumed relation between nasal obstruction and facial growth, especially vertical maxillary excess. The range of normal variation in oral versus nasal breathing has not been defined. This study attempted to correlate patient symptoms with respiratory mode. A sample of 20 symptomatic adult subjects presenting with nasal obstruction was compared to a control sample of 20 asymptomatic adults by means of SNORT (Simultaneous Nasal and Oral Respirometric Technique). Nasal resistance was significantly different between the two groups, but percent nasality (that proportion of the total volume of air breathed nasally) was a more consistent and significant finding. The relevance of these results to both clinical and basic physiology is discussed.

Nasofacial defect following fibrosarcoma excision and radiotherapy.

For initial reconstruction, Dr. Burget suggests that he would have advanced the cheek flap medially toward the nasal septum and, subsequently, reconstructed the missing right half of the nose with a forehead flap and cartilage grafts. Dr. Panje suggested early prosthetic rehabilitation, while Dr. Krause's concepts were similar to Dr. Burget's, with forehead flap nasal reconstruction, after cheek reconstruction to the nasofacial and nasolabial lines with a medially advanced cheek flap. Dr. Panje recommended an immediate maxillary denture prosthesis, as did Dr. Krause (who supplemented this with foam rubber). Dr. Burget placed the prosthesis 3 weeks after tumor ablation. For skin grafts, Drs. Panje and Burget suggested split thickness grafts to all new surfaces to decrease wound contracture, while Dr. Krause used dermis grafts for the same purpose. Other reconstructive methods mentioned were the (1) cervical tubed flap, (2) free scapular flap, (3) Washio flap, (4) tissue expansion, and (5) nasolabial flap. Suggestions for isolated defects included: Lower eyelid--increase internal support by building up the prosthesis; release lower lid from deltopectoral flap and V-Y advancement; support graft or irradiated cartilage (1-2 mm sheet) under orbicularis oculi. Nasal ala--bring present ala down and insert cartilage graft; turn internal skin down and fill the resulting defect with a composite graft. Upper lip--multiple Z-plasty. Retrodisplacement of cheek due to maxillectomy--release buccal scar; skin graft the raw internal surface and build up prosthesis.