RESUMEN
The influence of ocean acidification in deep-sea ecosystems is poorly understood but is expected to be large because of the presumed low tolerance of deep-sea taxa to environmental change. We used a newly developed deep-sea free ocean CO2 enrichment (dp-FOCE) system to evaluate the potential consequences of future ocean acidification on the feeding behavior of a deep-sea echinoid, the sea urchin, Strongylocentrotus fragilis. The dp-FOCE system simulated future ocean acidification inside an experimental enclosure where observations of feeding behavior were performed. We measured the average movement (speed) of urchins as well as the time required (foraging time) for S. fragilis to approach its preferred food (giant kelp) in the dp-FOCE chamber (-0.46 pH units) and a control chamber (ambient pH). Measurements were performed during each of 4 trials (days -2, 2, 24, 27 after CO2 injection) during the month-long period when groups of urchins were continuously exposed to low pH or control conditions. Although urchin speed did not vary significantly in relation to pH or time exposed, foraging time was significantly longer for urchins in the low-pH treatment. This first deep-sea FOCE experiment demonstrated the utility of the FOCE system approach and suggests that the chemosensory behavior of a deep-sea urchin may be impaired by ocean acidification.
Asunto(s)
Ácidos/química , Dióxido de Carbono/análisis , Conducta Alimentaria , Océanos y Mares , Erizos de Mar/fisiología , Análisis de Varianza , Animales , Concentración de Iones de Hidrógeno , Movimiento , Factores de TiempoRESUMEN
PURPOSE: Radical cystectomy as standard treatment of muscle-invasive urothelial carcinoma of the urinary bladder cures less than 50% of patients with locally advanced bladder cancer. We compared two adjuvant combination chemotherapies in patients with stage pT3a-4a and/or pathologic node-positive transitional-cell carcinoma of the bladder after radical cystectomy. PATIENTS AND METHODS: A total of 327 patients were randomly assigned to either adjuvant systemic chemotherapy with three cycles of cisplatin 70 mg/qm(2) on day 1 and methotrexate 40 mg/qm(2) on days 8 and 15 of a 21-day cycle (CM) or three cycles of methotrexate 30 mg/qm(2) on days 1, 15, and 22, vinblastine 3 mg/qm(2) on days 2, 15, and 22, epirubicin 45 mg/qm(2) on day 2, and cisplatin 70 mg/qm(2) on day 2 of a 28-day cycle (M-VEC). RESULTS: The hazard ratio for progression-free survival as the primary end point was 1.13 (90% CI, 0.86 to 1.48) for 163 CM patients compared with 164 M-VEC patients whose right-hand limit remained below the upper bound compatible with the noninferiority hypothesis (alpha = .0403). The 5-year progression-free, tumor-specific, and overall survival rates (point estimates +/- SE) for CM versus M-VEC were 46.3% +/- 4.6% v 48.8% +/- 4.5%, 52.0% +/- 4.6% v 52.3% +/- 4.8%, and 46.1% +/- 4.3% v 45.1% +/- 4.6%, respectively. WHO grade 3 and 4 leukopenia occurred in 7.0% of patients treated with CM and 22.2% of patients treated with M-VEC (P < .0001). CONCLUSION: CM cannot be considered inferior to M-VEC with regard to progression-free survival of patients with locally advanced bladder cancer after radical cystectomy. Moreover, patients receiving adjuvant CM combination therapy experienced significantly less grade 3 and 4 leukopenia than patients treated with M-VEC.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Cisplatino/administración & dosificación , Progresión de la Enfermedad , Epirrubicina/administración & dosificación , Femenino , Humanos , Masculino , Metotrexato/administración & dosificación , Persona de Mediana Edad , Análisis de Supervivencia , Resultado del Tratamiento , Neoplasias de la Vejiga Urinaria/cirugía , Vinblastina/administración & dosificaciónRESUMEN
Central to the Interacting Cognitive Subsystems framework (ICS) is the assertion that meaning exists at both the propositional and implicational levels. This assertion was tested by having 26 fast-year undergraduates make speeded judgements of emotional expression and emotional content in separate tasks on 120 single recorded words. Propositional meaning was represented by the content of the words while implicational meaning was conveyed by the expression of the word. In two tasks, participants decided whether the content or the expression of the word was emotional or neutral. In the expression task main effects were found for expression but not for content. In the content task main effects were found for both content and expression with an interaction between the two factors. Some congruency effects were evident in both tasks. Predictions of the framework concerning the independent processing and eventual integration of these two levels of meaning were partially supported. The significance of separating conceptual and schematic processing for other models of multilevel cognitive processing is addressed.
RESUMEN
We review the rapid progress made in the applications of Raman spectroscopy to deep-ocean science. This is made possible by deployment of instrumentation on remotely operated vehicles used for providing power and data flow and for precise positioning on targets of interest. Early prototype systems have now been replaced by compact and robust units that have been deployed well over 100 times on an expeditionary basis over a very wide range of ocean depths without failure. Real-time access to the spectra obtained in the vehicle control room allows for expedition decision making. Quantification of some of the solutes in seawater or pore waters observed in the spectra is made possible by self-referencing to the ubiquitous ν(2) water bending peak. The applications include detection of the structure and composition of complex thermogenic gas hydrates both occurring naturally on the sea floor and in controlled sea floor experiments designed to simulate the growth of such natural systems. New developments in the ability to probe the chemistry of sediment pore waters in situ, long thought impossible candidates for Raman study due to fluorescence observed in recovered samples, have occurred. This permits accurate measurement of the abundance of dissolved methane and sulfide in sediment pore waters. In areas where a high gas flux is observed coming out of the sediments a difference of about ×30 between in situ Raman measurement and the quantity observed in recovered cores has been found. New applications under development include the ability to address deep-sea biological processes and the ability to survey the sea floor chemical conditions associated with potential sub-sea geologic CO(2) disposal in abandoned oil and gas fields.
RESUMEN
The long-term fate of chemical weapon debris disposed of in the ocean some 50 years ago, now sinking into marine sediments and leaking into the ocean environment, is poorly known. Direct evidence exists showing chemical weapon agents actively being released on the sea floor with detrimental effects including harm to marine life. Thus there is strong interest in determining the fate and lifetime of these materials, their decomposition products, and the affected zones around these sites. Here we study the geochemical properties of a mustard gas breakdown product, 1,4-thioxane (TO), using Raman spectroscopy. We show that TO forms a hydrate with a help-gas (a second guest added to stabilize the hydrate), such as methane or hydrogen sulfide, with the hydrate stability regime some 10 degrees C above pure methane hydrate. The temperature, pressure, and reducing conditions required for hydrate formation commonly occur at known disposal sites. The TO solubility was measured in seawater and found to vary from 0.65 to 0.63 mol/kg water between 4.5 and 25.0 degrees C. Similar to other hydrate systems, the TO solubility decreased in the presence of hydrate. A low solubility in water coupled with its ability to form a hydrate within marine sediments can greatly decrease molecular mobility and increase its lifetime. These results demonstrate how unanticipated reactions with marine sediments can occur, and how little is known of the processes controlling the environmental science of these materials.
Asunto(s)
Guerra Química , Compuestos Heterocíclicos con 1 Anillo/análisis , Agua de Mar/química , Contaminantes Químicos del Agua/análisis , Solubilidad , Espectrometría RamanRESUMEN
A 24-yr-old woman presented with gross haematuria and a huge tumour of the right bladder wall. At transurethral resection, a solid tumour was seen covered with normal mucosa. The pathological evaluation revealed a solitary fibrous tumour (SFT) of the urinary bladder. For final treatment, a partial cystectomy was performed; tumour-free margins were ensured by frozen-section analysis. This is the first case in the literature presenting intravesically in a young woman. Due to the difficulty in discriminating between malignant and benign growth pattern of this tumour entity, a regular follow-up after conservative treatment is mandatory.
Asunto(s)
Hematuria/etiología , Hemodinámica/fisiología , Tumores Fibrosos Solitarios/complicaciones , Neoplasias de la Vejiga Urinaria/complicaciones , Cistectomía/métodos , Cistoscopía , Diagnóstico Diferencial , Femenino , Estudios de Seguimiento , Hematuria/diagnóstico , Hematuria/fisiopatología , Humanos , Imagen por Resonancia Magnética , Tumores Fibrosos Solitarios/diagnóstico , Tumores Fibrosos Solitarios/cirugía , Tomografía Computarizada por Rayos X , Neoplasias de la Vejiga Urinaria/diagnóstico , Neoplasias de la Vejiga Urinaria/cirugía , Adulto JovenRESUMEN
We used a newly developed in situ laser Raman spectrometer (LRS) for detection of elevated levels of dissolved CO2 in seawater. The experiment was carried out at 500 m depth, 6 degrees C, to examine new protocols for detection of CO2-enriched seawater emanating from a liquid CO2 source in the ocean, and to determine current detection limits under field conditions. A system of two interconnected 5 L chambers was built, with flow between them controlled by a valve and pump system, and this unit was mounted on an ROV. The first chamber was fitted with a pH electrode and the optical probe of the LRS. In the second chamber approximately 580 mL of liquid CO2 was introduced. Dissolution of CO2 across the CO2-seawater interface then occurred, the valves were opened, and a fixed volume of low-pH/CO2-enriched seawater was transferred to the first chamber for combined pH/Raman sensing, where we estimate a mean dissolution rate of approximately 0.5 (micromol/cm2)/s. This sequence was repeated, resulting in measurement of a progressively CO2 enriched seawater sample. The rapid in-growth of CO2 was readily detected as the Fermi dyad of the dissolved state with a detection limit of approximately 10 mM with spectral acquisition times of 150 s. The detection of background levels of CO2 species in seawater (approximately 2.2 mM, dominantly HCO3-) will require an improvement in instrument sensitivity by a factor of 5-10, which could be obtained by the use of a liquid core waveguide.
Asunto(s)
Dióxido de Carbono/análisis , Monitoreo del Ambiente/métodos , Agua de Mar/química , Animales , Electrodos , Concentración de Iones de Hidrógeno , Rayos Láser , Espectrometría Raman/métodos , TemperaturaRESUMEN
We have carried out the second phase of field studies to determine the effectiveness of a coflow injector which mixes liquid CO2 and ambient seawater to produce a hydrate slurry as a possible CO2 delivery method for ocean carbon sequestration. The experiments were carried out at ocean depths of 1000-1300 m in Monterey Bay, CA, using a larger injector than that initially employed under remotely operated vehicle control and imaging of the product. Solidlike composite particles comprised of water, solid CO2 hydrate, and liquid CO2 were produced in both studies. In the recent injections, the particles consistently sank at rates of approximately 5 cm s(-1). The density of the sinking particles suggested that approximately 40% of the injected CO2 was converted to hydrate, while image analysis of the particle shrinking rate indicated a CO2 dissolution rate of 0.76-1.29 micromol cm(-2) s(-1). Plume modeling of the hydrate composite particles suggests that while discrete particles may sink 10-70 m, injections with CO2 mass fluxes of 1-1000 kg s(-1) would result in sinking plumes 120-1000 m belowthe injection point.
Asunto(s)
Dióxido de Carbono/análisis , Carbono/química , Monitoreo del Ambiente/métodos , Agua de Mar/química , Carbono/análisis , Dióxido de Carbono/química , Concentración de Iones de Hidrógeno , Procesamiento de Imagen Asistido por Computador , Modelos Teóricos , Nitrógeno/análisis , Solubilidad , Factores de TiempoRESUMEN
PURPOSE: We evaluated the prognostic parameters of necrotic residual tumors after chemotherapy of advanced germ cell tumors to improve on the current indications for surgery. MATERIALS AND METHODS: Between January 1996 and January 2000, in 8 centers of the German Testicular Cancer Study Group, preoperative parameters were assessed to predict necrosis in the residual tumors of 261 patients with retroperitoneal residual tumor resection after first (92%) and second line (8%) chemotherapy. RESULTS: Of 232 evaluable patients 39 had pure seminoma and 5 had viable cancer (1 with seminoma) in the residual tumor. Of the remaining 193 patients with nonseminoma 35% had necrosis, 34% teratoma and 31% had viable carcinoma in the residual tumor. After multivariate analysis and exclusion of patients with seminoma, the 3 parameters independently predictive of necrosis were alpha-fetoprotein before chemotherapy less than 20 ng/ml, and tumor volume before and after chemotherapy. A mathematical model to predict necrosis yielded a test accuracy of 75%, a sensitivity to predict necrosis of 52% and a specificity of 87%. CONCLUSIONS: Patients with pure seminoma should not undergo residual tumor resection because 97% of patients who received adequate chemotherapy were found to have no residual seminoma. In cases of nonseminoma alpha-fetoprotein values before chemotherapy less than 20 ng/ml and a high percentage of shrinkage during chemotherapy reliably predicted only 19% of cases of necrosis. Therefore, this model is clinically irrelevant and patients with minimal residual disease should undergo surgery. New methods are necessary to improve the preoperative selection of patients after chemotherapy.
Asunto(s)
Germinoma/tratamiento farmacológico , Germinoma/patología , Neoplasias Testiculares/tratamiento farmacológico , Neoplasias Testiculares/patología , Humanos , Masculino , Necrosis , Estadificación de Neoplasias , Neoplasia Residual , Pronóstico , Estudios Prospectivos , Neoplasias Retroperitoneales/patologíaRESUMEN
This paper reports on the formation and dissolution of CO2/seawater/CO2 hydrate composite particles produced during field experiments in Monterey Bay, CA using a CO2 injector system previously developed in the laboratory. The injector consisted of a coflow reactor wherein water was introduced as a jet into liquid CO2, causing vigorous mixing of the two immiscible fluids to promote the formation of CO2 hydrate that is stable at ambient pressures and temperatures typical of ocean depths greater than approximately 500 m. Using flow rate ratios of water and CO2 of 1:1 and 5:1, particulate composites of CO2 hydrate/liquid CO2/seawater phases were produced in seawater at depths between 1100 and 1300 m. The resultant composite particles were tracked by a remotely operated vehicle system as they freely traveled in an imaging box that had no bottom or top walls. Results from the field experiments were consistent with laboratory experiments, which were conducted in a 70 L high-pressure vessel to simulate the conditions in the ocean at intermediate depths. The particle velocity and volume histories were monitored and used to calculate the conversion of CO2 into hydrate and its subsequent dissolution rate after release into the ocean. The dissolution rate of the composite particles was found to be higher than that reported for pure CO2 droplets. However, when the rate was corrected to correspond to pure CO2, the difference was very small. Results indicate that a higher conversion of liquid CO2 to CO2 hydrate is needed to form negatively buoyant particles in seawater when compared to freshwater, due primarily to the increased density of the liquid phase but also due to processes involving brine rejection during hydrate formation.