Stability of the Malvinas Current.

Deterministic and probabilistic tools from nonlinear dynamics are used to assess enduring near-surface Lagrangian aspects of the Malvinas Current. The deterministic tools are applied to a multiyear record of velocities derived from satellite altimetry data, revealing a resilient cross-stream transport barrier. This is composed of shearless-parabolic Lagrangian coherent structures (LCSs), which, extracted over sliding time windows along the multiyear altimetry-derived velocity record, lie in near-coincidental position. The probabilistic tools are applied on a large collection of historical satellite-tracked drifter trajectories, revealing weakly communicating flow regions as basins of attraction for long-time asymptotic almost-invariant sets on either side of the altimetry-derived barrier. Shearless-parabolic LCSs are detected for the first time from altimetry data, and their significance is supported on satellite-derived ocean color data, which reveal shapes that quite closely resemble the peculiar V shapes, dubbed "chevrons," that have recently confirmed the presence of similar LCSs in the atmosphere of Jupiter. Finally, using available in situ velocity and hydrographic data, sufficient and necessary conditions for nonlinear symmetric stability are found to be satisfied, suggesting a duality between Lagrangian and Eulerian stability for the Malvinas Current.

Sea level anomaly on the Patagonian continental shelf: Trends, annual patterns and geostrophic flows.

We study the annual patterns and linear trend of satellite sea level anomaly (SLA) over the southwest South Atlantic continental shelf (SWACS) between 54ºS and 36ºS. Results show that south of 42°S the thermal steric effect explains nearly 100% of the annual amplitude of the SLA, while north of 42°S it explains less than 60%. This difference is due to the halosteric contribution. The annual wind variability plays a minor role over the whole continental shelf. The temporal linear trend in SLA ranges between 1 and 5 mm/yr (95% confidence level). The largest linear trends are found north of 39°S, at 42°S and at 50°S. We propose that in the northern region the large positive linear trends are associated with local changes in the density field caused by advective effects in response to a southward displacement of the South Atlantic High. The causes of the relative large SLA trends in two southern coastal regions are discussed as a function meridional wind stress and river discharge. Finally, we combined the annual cycle of SLA with the mean dynamic topography to estimate the absolute geostrophic velocities. This approach provides the first comprehensive description of the seasonal component of SWACS circulation based on satellite observations. The general circulation of the SWACS is northeastward with stronger/weaker geostrophic currents in austral summer/winter. At all latitudes, geostrophic velocities are larger (up to 20 cm/s) close to the shelf-break and decrease toward the coast. This spatio-temporal pattern is more intense north of 45°S.

Patients' survival after free flap reconstructive surgery of head and neck squamous cell carcinoma: a retrospective multicentre study.

Head and neck squamous cell carcinoma of the (HNSCC) represents approximately 5% of malignant tumours in Italy. HNSCC are commonly treated with surgery or radiotherapy, or a combination of such therapies. The objectives of treatment are maximum cure rate balanced with organ preservation, restoration of form and function, reduction of morbidities and improvement or maintenance of the patient's quality of life. Immediate reconstructive surgery: local, regional or free flaps are now widely advised in the treatment of these patients. Microsurgical transfer requires expertise, is time and resource consuming, and as a whole requires substantial costs. These considerations introduce some concerns about the wide or indiscriminate use of free flap reconstructive surgery. When considering cost-benefit outcomes of such treatment, the main objective is undoubtedly, survival. This data is underreported in the current literature, whereas functional outcomes of free flaps have been largely diffused and accepted. This study collects data from 1178 patients treated with free flap reconstructive surgery following ablation of HNSCC in a group of Italian tertiary hospitals, all members of the Head & Neck Group affiliated with the Italian Society of Microsurgery. According to many authors, free flap surgery for HNSCC seems to be a beneficial option for treatment even in terms of survival.

Poincaré-Birkhoff theorem in quantum mechanics.

Quantum manifestations of the dynamics around resonant tori in perturbed hamiltonian systems, dictated by the Poincaré-Birkhoff theorem, are shown to exist. They are embedded in the interactions involving states which differ in a number of quanta equal to the order of the classical resonance. Moreover, the associated classical phase space structures are mimicked in the quasiprobability density functions and their zeros.

Autonomous reparative unit (ARU): a new concept of repairing free flap donor site with local full-thickness skin graft.

Usually, harvesting free flap in the limbs creates an inevitable sequence of aesthetic damage not only in the donor site but also in the area of the graft used to repair the free flap donor site. Aim of the study was to standardize a simple method, defined Autonomous Reparative Unit, that allows closing of the donor site defects with a skin graft from the adjacent cutaneous area, avoiding further aesthetic damage in a third area. We define the "Autonomous Reparative Unit" as the rectangular shaped skin area of the flap and the dermoepidermic skin graft designed as an isoscele triangle with the base adjacent to the smaller side of the flap defect. From 2003 to 2008, at the Fondazione IRCCS Istituto Nationale Tumori of Milan, 143 free radial forearm flaps and 42 free osteofasciocutaneous fibula flaps have been performed for head and neck cancer. The autonomous reparative unit has been applicable in 177 cases (92.1%). The autonomous reparative unit method allows a "standard"primary reconstructive unit to be created which can be used in a single or in multiple ways thus avoiding an additional surgical scar and a subsequent additional aesthetic impairment.

Review of 346 patients with free-flap reconstruction following head and neck surgery for neoplasm.

We present our 14-year experience of free tissue transfer following surgery for head and neck neoplasm. We evaluated 346 patients mean age 57 years, 65% had squamous cell carcinoma; the most frequent sites were oral cavity and mandible (168) craniomaxillo facial region (94) pharynx +/- cervical oesophagus and oropharyngostomes (84). In 327 (95%) cases the reconstruction was a success. Flap revision was necessary in 29 (8.4% of total) and recovery was successful in 10/29. Nine patients (2.6%) died perioperatively. Poor preoperative condition, previous treatment, and requirement for vein graft were significantly associated with increased risk of major complications after surgery. Cosmetic and functional outcomes were assessed on 1-10 scales: 69 and 77% of patients, respectively, had cosmetic and functional results in the 7-10 range, indicating successful outcome. Overall survival probabilities, estimated on 338 patients with malignant disease, were 53% at 2 years and 32% at 5 years. Most patients, but not all, had advanced disease stage, and 188 (54%) had recurrent disease. Hence, overall survival rates are acceptable and justify the use of complex reconstruction procedures in such patients.

Adenocarcinoma of ethmoid sinus: an occupational disease.

Sinonasal tumours, particularly those of ethmoidal origin, are rare neoplasms, of which adenocarcinoma is the most frequent histotype in Europe. The association between sinonasal malignancies and exposure to wood or leather dusts has been widely documented, however, the precise tumour site and histology has seldom been reported. In the present study, exposure to wood or leather dusts was investigated in 499 patients diagnosed with sinonasal tumours, who were treated at the Head and Neck Surgery Department of the National Cancer Institute of Milan, Italy, between 1987 and 2001. The original tumour site and histology were carefully assessed. Of the 499 patients evaluated, 249 had ethmoidal tumours; 124 of which adenocarcinomas, affecting 115 males; 9 females. Of the males with adenocarcinoma, 90.4% had been exposed to wood or leather dusts; 16.3% of these had only been exposed for a short time and long before onset of the disease (median exposure 11 years; median latency 31 years). Of the remaining 125 patients with ethmoidal tumours other than adenocarcinomas, only 2 (1.6%) had ever been exposed to these dusts. Non-ethmoidal sinonasal tumours were seen in 250 cases; 17 of these (6.8%) were adenocarcinomas; no exposure to wood or leather dusts was reported in any of these patients. Ethmoid proved to be the sinonasal site affected by adenocarcinomas induced by exposure to wood or leather dusts. Even brief exposure, which may have occurred a very long time before onset of the disease, seems to be sufficient to increase the incidence of this tumour type. No significant correlation was observed between exposure and either non-ethmoidal sinonasal neoplasms or ethmoidal tumours other than adenocarcinomas.

Fredholm methods for billiard eigenfunctions in the coherent state representation

We obtain a semiclassical expression for the projector onto eigenfunctions by means of the Fredholm theory. We express the projector in the coherent state basis, thus obtaining the semiclassical Husimi representation of the stadium eigenfunctions, which is written in terms of classical invariants: periodic points, their monodromy matrices, and Maslov indices.

The quantized D-transformation.

We construct a new example of a quantum map, the quantized version of the D-transformation, which is the natural extension to two dimensions of the tent map. The classical, quantum and semiclassical behavior is studied. We also exhibit some relationships between the quantum versions of the D-map and the parity projected baker's map. The method of construction allows a generalization to dissipative maps which includes the quantization of a horseshoe. (c) 1996 American Institute of Physics.

Anatomy of the trace formula for the baker's map.

The structure of the trace formula for quantum maps on a compact phase space is analyzed. An explicit expression for the functional determinant in terms of a finite number of traces is derived which is algebraic and independent of any approximation. For the specific case of the baker's map, its simple structure allows the implementation of a symbolic decomposition of the propagator which is exact and which has the structure of usual semiclassical formulas. The method allows the testing of the accuracy of the individual contribution of each periodic orbit to the functional determinant.

Local adoptive immunotherapy of advanced head and neck tumors with LAK cells and interleukin-2.

Since October 1987 a pilot phase I-II study on the effect of loco-regional injections of recombinant interleukin 2 (rIL-2) in association with LAK cells has been performed in advanced, recurrent head and neck cancer patients. Fourteen patients were treated with autologous LAKs and rIL-2 (Glaxo) given peritumorally and in the mastoid region (rIL-2 only in the latter site). LAKs (2-70 x 10(7)) + rIL-2 were injected on the first day of therapy, followed by 9 daily injections of rIL-2 only. The total daily dose of rIL-2 was escalated from 2,400 to 1.8 x 10(6) IU. Clinical evaluation was performed 30 days from the onset of therapy; 3 partial (95%, 66% and 50% reduction) and 3 minor responses were seen in the evaluated patients. All the other patients with a progressive disease after the first cycle were shifted to palliative chemotherapy. The partial responses were found in patients with a tumor burden less than 20 cm2. Cervical node metastasis did not respond to treatment. No relevant side effects occurred. These results indicate that loco-regional immunotherapy with rIL-2 and LAK cells can produce clinical responses in advanced head and neck cancer patients.

In vivo interleukin 2-induced activation of lymphokine-activated killer cells and tumor cytotoxic T-cells in cervical lymph nodes of patients with head and neck tumors.

To study whether regional injection of recombinant interleukin 2 (rIL-2) can induce an in vivo lymphocyte activation in cervical lymph nodes (LNs) of patients with head and neck carcinoma, 12 patients, candidates for prophylactic dissection, were treated for 7-10 days prior to surgery with rIL-2, 10(5) units/day, injected in the perimastoid region. A marked induction of cytotoxic activity against allogeneic (K562 and Daudi lines) and autologous target cells (fresh spindle cell carcinomas of the tongue) was observed in lymphocytes obtained from jugular, spinal, and, to a lesser extent, submandibular LNs of all treated patients. An increase of cytotoxicity was also present in LNs contralateral to the rIL-2 injection side. On the other hand, only a borderline increase in spontaneous proliferation was detected. Moreover, in the two cases tested, a marked and apparently autologous tumor (Auto-Tu)-specific lysis was found in CD5+ lymphocytes obtained from LNs, whereas lymphokine-activated killer activity was mainly exerted by CD16+ natural killer cells. T-lymphocytes, when cultured with irradiated Auto-Tu cells and low doses of rIL-2, showed an increased Auto-Tu lysis, while cytotoxicity against allogeneic tumor cells (including K562) was not observed. These data indicate that regional injection of rIL-2 can activate lymphokine-activated killer cells from LN lymphocytes but also induce and/or expand a T-cell population expressing a restricted Auto-Tu cytotoxicity.

Alternating cisplatinum and VAC ineffective in end stage squamous cell carcinoma of the head and neck.

Sixteen patients with end stage squamous cell carcinoma of the head and neck were admitted to a phase II study of alternating courses of cisplatinum (100 mg/m2) and VAC (vincristine 1.4 mg/m2, adriamycin 50 mg/m2, cyclophosphamide 750 mg/m2) given at three weekly intervals. Only two patients achieved a response (12 per cent). The median survival time was 62 days which is much the same as that of a similar group of patients who received no chemotherapy in a previous trial (70 days).

[Precancerous oral lesions. Diagnostic and therapeutic protocol]. / Le precancerosi orali. Protocollo di diagnosi e terapia.

The NRC (National Research Council) task force on head and neck cancer issued this document to help clinicians involved in diagnosing and treating precancerous oral diseases. Chapter 1 includes definition, epidemiology, risk factors (alcohol, smoking, poor oral hygiene), WHO classification, clinical picture of leukoplakias, erythroplasia, lichen planus, as well as their natural history. Chapter 2 points out the clinical signs to be looked for in order to make a proper diagnosis and discusses biopsy techniques. Chapter 3 deals with therapeutic procedures (surgical technique and medical treatment), while Chapter 4 concerns follow-up according to the clinical and histological diagnosis. Finally, some statistical forms are enclosed: Form 1 consists of information regarding educational qualifications, occupation, alcohol consumption, smoking and dietary habits; Form 2 consists of information about previous diseases and the history of the present disease; Form 3 records the signs and symptoms observed for the precancerous lesion; Form 4 records treatment modalities; Form 5 records patient follow-up.