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1.
《Aquatic Botany》2005,81(3):213-224
The annual leaf growth and shoot dynamics of Thalassia testudinum were examined in a meadow located near Havana City, Cuba, using direct censuses between January 1995 and January 1996. The net rate of shoot population change, specific shoot recruitment and mortality rates were calculated as the difference between the densities of shoots (tagged or untagged) in consecutive sampling events. The leaf biomass, the daily production, the turnover rate and the rate of leaf biomass loss were also estimated. The estimated mean dry leaf biomass (124.9 ± 9.5 g m−2), daily dry leaf production (3.3 ± 0.2 g m−2 day−1) and turnover rate (2.7 ± 0.1% day−1) were comparable to values previously reported for this species in Cuba and elsewhere. The production of leaves and shoots were higher in spring, declined towards mid summer, and showed the minimum values in January. Shoot recruitment prevailed over shoot mortality from January to March and from July to August, whereas most of the annual shoot mortality occurred between May and July and between August and October. The meadow examined was in close demographic balance along the study period. The results demonstrate that direct census provides reliable estimates of rapid shoot dynamics in T. testudinum.  相似文献   

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3.
Gulf Menhaden (Brevoortia patronus) are a species of commercial and ecological importance in the northern Gulf of Mexico, provisioning the second largest fishery by weight, in the United States, and providing critical ecosystem services in the coastal region. The recruitment and productivity dynamics of the stock are influenced by a suite of environmental factors but an understanding of the factors that determine individual variation in oil content (an indicator of an individual’s commercial value to the fishery and its dietary value to predators) has not been well described. In this work I describe the temporal dynamics of oil content and determine the demographic characteristics that provide predictive power to describe annual contrasts. I relate the predicted patterns in oil yield to a suite of seasonal environmental data series including: the magnitude of spring Mississippi River discharge, spring wind vectors, and the preceding winter El Nino conditions. Two uncorrelated (r = 0.06, p = 0.81) population-level predictor variables were identified that have explanatory power to describe temporal patterns in oil content (L kg−1); a weight-at-length power function parameter (a) and the von Bertalanffy asymptotic fork length (L, mm FL): L kg−1 =  0.158  0.026*a  0.00163*L (p < 0.05, R2 = 0.42). Analysis of the impacts of environmental variables on the oil content of Gulf Menhaden was evaluated comprehensively in a Bayesian framework by transforming the observed oil content information from two sources to a common scale. Parameters relating oil content to spring Mississippi River discharge and the preceding winter (December–February) El Nino Southern Oscillation index resulted in sample distributions from the posterior where zero was outside the 95% credible interval. This work contributes to the understanding of Gulf Menhaden as a prey species in the Gulf of Mexico and indicates that the value of the species to both the fishery and predators exhibits relatively large inter-annual variability controlled, in part, by seasonal environmental conditions.  相似文献   

4.
BackgroundMeasurement of the biomarker copeptin may help identify disease severity and risk of mortality for a various diseases. This study sought to determine the relationship between copeptin and all-cause mortality of patients with cardio-cerebrovascular disease.MethodsDatabase of Medline and Web of Science were searched for studies with data involving the baseline copeptin levels and subsequent all-cause mortality outcomes. The pooled HRs of all-cause mortality were calculated and presented with 95%CIs. Subgroup analysis and sensitivity analysis were conducted to explore the possible sources of heterogeneity.ResultsData from 14,395 participants were derived from 28 prospective studies. Higher copeptin significantly increased the risk of all-cause mortality (per unit copeptin: HR = 1.020, 95%CI = 1.004–1.036; log unit copeptin: HR = 2.884, 95%CI = 1.844–4.512; categorical copeptin: HR = 3.371, 95%CI = 2.077–5.472). Subgroup analysis indicated that the risk of all-cause death was higher in cerebrovascular patients (per unit copeptin: HR = 2.537, 95%CI = 0.956–6.731; log unit copeptin: HR = 3.419, 95%CI = 2.391–4.888) than cardiovascular patients (per unit copeptin: HR = 1.011, 95%CI = 1.002–1.020; log unit copeptin: HR = 2.009, 95%CI = 1.119–3.608).ConclusionCopeptin is associated with all-cause mortality of patients with cardiovascular and cerebrovascular disease. Our study suggests that copeptin seems to be a promising novel biomarker for prediction of mortality in cardio-cerebrovascular patients, especially for cerebrovascular patients.  相似文献   

5.
Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is a worldwide emerging pest of soft fruits, but its cold tolerance has not been thoroughly explored. We determined the cold tolerance strategy, low temperature thermal limits, and plasticity of cold tolerance in both male and female adult D. suzukii. We reared flies under common conditions (long days, 21 °C; control) and induced plasticity by rapid cold-hardening (RCH, 1 h at 0 °C followed by 1 h recovery), cold acclimation (CA, 5 days at 6 °C) or acclimation under fluctuating temperatures (FA). D. suzukii had supercooling points (SCPs) between −16 and −23 °C, and were chill-susceptible. 80% of control flies were killed after 1 h at −7.2 °C (males) or −7.5 °C (females); CA and FA improved survival of this temperature in both sexes, but RCH did not. 80% of control flies were killed after 70 h (male) or 92 h (female) at 0 °C, and FA shifted this to 112 h (males) and 165 h (females). FA flies entered chill coma (CTmin) at approximately −1.7 °C, which was ca. 0.5 °C colder than control flies; RCH and CA increased the CTmin compared to controls. Control and RCH flies exposed to 0 °C for 8 h took 30–40 min to recover movement, but this was reduced to <10 min in CA and FA. Flies placed outside in a field cage in London, Ontario, were all killed by a transient cold snap in December. We conclude that adult phenotypic plasticity is not sufficient to allow D. suzukii to overwinter in temperate habitats, and suggest that flies could overwinter in association with built structures, or that there may be additional cold tolerance imparted by developmental plasticity.  相似文献   

6.
Many polygynous ungulates show higher mortality of males than of females, because of the intense male–male competition during the rut and the costs associated with the development of sexual-size dimorphism. In the weakly dimorphic Alpine chamois Rupicapra rupicapra the occurrence of differential sex-specific survival strategies is controversial. To date, only two studies investigated the survivorship of males and females in this species, producing conflicting results: these works, based on the use of life tables, require confirmation from researches carried out on living populations. We assessed the survival pattern of a protected Alpine chamois population in the Swiss National Park, where 116 individuals were marked and monitored over 13 years (1996–2008). We tested for sex-, age- and year-dependence of survival by means of capture-mark-resight models. Resighting probabilities were sex-dependent, and survival rates were time-dependent. Females had higher resighting probabilities (0.84) than males (0.74). All over the time periods, sex had a weak influence on survival probability (males = 0.91; females = 0.92) and survival rates remained surprisingly high until late age (1 year = 0.90; 2–7 years = 0.91; 8+ years = 0.92). The growing evidence for a high adult survival and a weak differential mortality of the two sexes, together with the highly seasonal sexual-size dimorphism observed for Alpine chamois, might indicate the occurrence of a unique conservative survival strategy in both sexes and a low-risk mating strategy by males.  相似文献   

7.
Functional indicators are being increasingly used to assess waterway health but their responses to pressure in non-wadeable rivers have not been widely documented or applied in modern survey designs that provide unbiased estimates of extent. This study tests the response of river metabolism and loss in cotton strip tensile strength across a land use pressure gradient in non-wadeable rivers of northern New Zealand, and reports extent estimates for river metabolism and decomposition rates. Following adjustment for probability of selection, ecosystem respiration (ER) and gross primary production (GPP) for the target population of order 5–7 non-wadeable rivers averaged −7.3 and 4.8 g O2 m−2 d−1, respectively, with average P/R < 1 indicating dominance by heterotrophic processes. Ecosystem respiration was <−3.3 g O2 m−2 d−1 for 75% of non-wadeable river length with around 20% of length between −10 and −20 g O2 m−2 d−1. Cumulative distribution functions of cotton strength loss estimates indicated a more-or-less linear relationship with river km reflecting an even spread of decay rates (range in k 0.0007–0.2875 d−1) across non-wadeable rivers regionally. A non-linear relationship with land cover was detected for GPP which was typically <5 g O2 m−2 d−1 where natural vegetation cover was below 20% and greater than 80% of upstream catchment area. For cotton strength loss, the relationship with land cover was wedge-shaped such that sites with >60% natural cover had low decay rates (<0.02 d−1) with variability below this increasing as natural cover declined. Using published criteria for assessing waterway health based on ER and GPP, 232–298 km (20–29%) of non-wadeable river length was considered to have severely impaired ecosystem functioning, and 436–530 km (42–50%) had no evidence of impact on river metabolism.  相似文献   

8.
PurposeTo examine the overall and stage-specific age-adjusted incidence, 5-year survival and mortality rates of bladder cancer (BCa) in the United States, between 1973 and 2009.Materials and methodsA total of 148,315 BCa patients were identified in the Surveillance, Epidemiology and End Results database, between years 1973 and 2009. Incidence, mortality, and 5-year cancer-specific survival rates were calculated. Temporal trends were quantified using the estimated annual percentage change (EAPC) and linear regression models. All analyses were stratified according to disease stage, and further examined according to sex, race, and age groups.ResultsIncidence rate of BCa increased from 21.0 to 25.5/100,000 person-years between 1973 and 2009. Stage-specific analyses revealed an increase incidence for localized stage: 15.4–20.2 (EAPC: +0.5%, p < 0.001) and distant stage: 0.5–0.8 (EAPC: +0.7%, p = 0.001). Stage-specific 5-year survival rates increased for all stages, except for distant disease. No significant changes in mortality were recorded among localized (EAPC: ?0.2%, p = 0.1) and regional stage (EAPC: ?0.1%, p = 0.5). An increase in mortality rates was observed among distant stage (EAPC: +1.0%, p = 0.005). Significant variations in incidence and mortality were recorded when estimates were stratified according to sex, race, and age groups.DiscussionAlbeit statistically significant, virtually all changes in incidence and mortality were minor, and hardly of any clinical importance. Little or no change in BCa cancer control outcomes has been achieved during the study period.  相似文献   

9.
ObjectiveTo compare the ability of thyroid hormones, IL-6, IL-10, and albumin to predict mortality, and to assess their relationship in case-mix acute critically ill patients.MethodsAPACHE II scores and serum thyroid hormones (FT3, FT4, and TSH), IL-6, IL-10, and albumin were obtained at EICU admission for 79 cases of mix acute critically ill patients without previous history of thyroid disease. Patients were followed for 28 days with patient’s death as the primary outcome. All mean values were compared, correlations assessed with Pearson’ test, and mortality prediction assessed by multivariate logistic regression and ROC.ResultsNon survivors were older, with higher APACHE II score (p = 0.000), IL-6 (p < 0.05), IL-10 (p = 0.000) levels, and lower albumin (p = 0.000) levels compared to survivors at 28 days. IL-6 and IL-10 had significant negative correlation with albumin (p = 0.001) and FT3 (p  0.05) respectively, while low albumin had a direct correlation with FT3 (p < 0.05). In the mortality prediction assessment, IL-10, albumin and APACHE II were independent morality predictors and showed to have a good (0.70–0.79) AUC-ROC (p < 0.05). Despite that the entire cohort showed low FT3 serum levels (p = 0.000), there was not statistical difference between survivors and non-survivors; neither showed any significance as mortality predictor.ConclusionsIL-6 and IL-10 are correlated with Low FT3 and hypoalbuminemia. Thyroid hormones assessed at EICU admission did not have any predictive value in our study. And finally, high levels of IL-6 and IL-10 in conjunction with albumin could improve our ability to evaluate disease’s severity and predict mortality in the critically ill patients. When use in combination with APACHE II scores, our model showed improved mortality prediction.  相似文献   

10.
This study is the first to calibrate acceleration transmitters with energy expenditure using a vertebrate model species. We quantified the relationship between acoustic accelerometer output and oxygen consumption across a range of swim speeds and water temperatures for Harrison River adult sockeye salmon (Oncorhynchus nerka). First, we verified that acceleration transmitters with a sampling frequency of 10 Hz could be used as a proxy for movement in sockeye salmon. Using a mixed effects model, we determined that tailbeat frequency and acceleration were positively correlated (p < 0.0001), independent of tag ID. Acceleration (p < 0.0001) was positively related to swim speed while fork length (p = 0.051) was negatively related to swim speed. Oxygen consumption and accelerometer output (p < 0.0001) had a positive linear relationship and were temperature dependent (p < 0.0001). There were no differences in swim performance (F2,12 = 1.023, p = 0.820) or oxygen consumption (F1,12 = 0.054, p = 0.332) between tagged and untagged individuals. Five tagged fish were released into the Fraser River estuary and manually tracked. Of the five fish, three were successfully tracked for 1 h. The above relationships were used to determine that the average swim speed was 1.25 ± 0.03 body lengths s? 1 and cost of transport was 3.39 ± 0.17 mg O2 kg? 1 min? 1, averaged across the three detected fish. Acceleration transmitters can be effectively used to remotely evaluate fine-scale behavior and estimate energy consumption of adult Pacific salmon throughout their homeward spawning migration.  相似文献   

11.
We determined the probability of individuals having the ‘optimal’ mitochondrial biogenesis related endurance polygenic profile, and compared the endurance polygenic profile of Israeli (Caucasian) endurance athletes (n = 74), power athletes (n = 81), and non-athletes (n = 240). We computed a mitochondrial biogenesis related ‘endurance genotype score’ (EGS, scoring from 0 to 100) from the accumulated combination of six polymorphisms in the PPARGC1A-NRF-TFAM pathway. Some of the variant alleles of the polymorphisms studied were so infrequent, that the probability of possessing an ‘optimal’ EGS (= 100) was 0% in the entire study population. However, the EGS was significantly higher (P < 0.001) in endurance athletes (38.9 ± 17.1) compared with controls (30.6 ± 12.4) or power athletes (29.0 ± 11.2). In summary, although the probability of an individual possessing a theoretically ‘optimal’ genetic background for endurance sports is very low, in general endurance athletes have a polygenic profile that is more suitable for mitochondrial biogenesis.  相似文献   

12.
《Acta Oecologica》2007,31(2):151-157
One consequence of human-induced changes in fire regimes has been the invasion of fire-prone Mediterranean ecosystems by weeds from more mesic habitats. In southern Australia, the tree Pittosporum undulatum Vent. has established in new areas, causing a serious reduction in floristic and structural diversity. Pittosporum undulatum has a high competitive ability and creates an environment that favours its own progeny at the expense of other species, making control difficult. We tested the hypothesis that fire effectively disrupts this invasion cycle by (1) eliminating the soil and canopy seed bank, (2) reducing the competitive ability of adults, and (3) minimising the number of sites favourable to invasion. To test this, the ability of P. undulatum to re-establish after a prescribed burn was estimated in a field study. The field data were then compared with the experimentally determined sensitivity of seeds and seedlings to elevated temperatures. The experimentally determined combination of temperatures and exposure time required for seed mortality (90–120 °C, depending on duration) was such that most seed stored in the canopy would be killed by prescribed burning. In addition, 90% of seedlings (ca. 0.4 m tall) were killed when heated to 180 °C for 5–10 min in the laboratory, consistent with the observed 100% seedling mortality in the burnt plots. Of the adult trees, 20% resprouted within 6 months of the fire. We conclude that the temperatures associated with wildfires are sufficient to act as a circuit breaker on the invasion cycle allowing other control measures, such as poisoning and weeding to be employed to greater effect.  相似文献   

13.
Visfatin is linked to inflammation and associated with clinical outcomes of intracerebral hemorrhage. This study was designed to investigate whether visfatin might serve as a marker of severity and prognosis in aneurysmal subarachnoid hemorrhage. In this study, plasma visfatin levels of 172 consecutive patients and 172 sex and age-matched healthy subjects were determined using enzyme-linked immunosorbent assay. The recorded clinical outcomes included in-hospital mortality and 6-month mortality and unfavorable outcome (Glasgow Outcome Scale score of 1–3). Plasma visfatin level was substantially higher in patients than in healthy controls (92.1 ± 20.5 ng/mL vs. 12.4 ± 3.2 ng/mL; P < 0.001), was significantly associated with the World Federation of Neurological Surgeons (WFNS) score (r = 0.569, P < 0.001) and Fisher score (r = 0.657, P < 0.001), was an independent predictor of in-hospital mortality [odds ratio (OR), 1.378; 95% confidence interval (CI), 1.036–1.866; P = 0.002] and 6-month mortality (OR, 1.261; 95% CI, 1.018–1.745; P = 0.004) and unfavorable outcome (OR, 1.207; 95% CI, 1.012–1.682; P = 0.008) in multivariate logistic regression analysis and had high predictive value for in-hospital mortality [area under curve (AUC), 0.849; 95% CI, 0.787–0.899; P < 0.001] and 6-month mortality (AUC, 0.868; 95% CI, 0.808–0.915; P < 0.001) and unfavorable outcome (AUC, 0.859; 95% CI, 0.797–0.907; P < 0.001) using receiver operating characteristic curves. AUCs of visfatin were similar to those of WFNS score and Fisher score (all P > 0.05), but visfatin did not improve the predictive values of WFNS score and Fisher score (all P > 0.05). Thus, visfatin may be associated with clinical severity of aneurysmal subarachnoid hemorrhage and also have prognostic value for clinical outcomes.  相似文献   

14.
BackgroundElevated plasma vitamin B12 levels (cobalamin, Cbl) are associated with increased short-term cancer risk among patients referred for this laboratory measurement. We aimed to assess prognosis in cancer patients with elevated plasma Cbl.MethodsWe conducted a population-based cohort study using data from Danish medical registries during 1998–2014. The study included 25,017 patients with a cancer diagnosis and Cbl levels of 200–600 pmol/L (reference/normal range), 601–800 pmol/L and >800 pmol/L measured up to one year prior to diagnosis, and a comparison cohort of 61,988 cancer patients without a plasma Cbl measurement. Patients treated with Cbl were excluded. Survival probability was assessed using Kaplan–Meier curves. Mortality risk ratios (MRR) were computed using Cox proportional hazard regression, adjusted for age, sex, calendar year, cancer stage and comorbidity, scored using the Charlson comorbidity index.ResultsSurvival probabilities were lower among patients with elevated Cbl levels than among patients with normal levels and among members of the comparison cohort [(1-year survival,%) Cbl: 200–600 pmol/L: 69.3%; 601–800 pmol/L: 49.6%; >800 pmol/L: 35.8%; comparison cohort: 72.6%]. Thirty-day mortality was elevated for patients with Cbl levels of 601–800 pmol/L or >800 pmol/L, compared to patients with levels of 200–600 pmol/L [(MRR (95% confidence interval): 601–800 pmol/L vs. 200–600 pmol/L: 1.9 (1.6–2.2); >800 pmol/L vs. 200–600 pmol/L: 2.7 (2.4–3.1)]. This association remained robust for 31–90-day and 91–365-day mortality, showing similar dose-response patterns.ConclusionCancer patients with elevated Cbl levels had higher mortality than those with normal Cbl levels. These findings may have clinical significance for assessing the prognosis of cancer patients.  相似文献   

15.
Blooms caused by some species belonging to the dinoflagellate genus Alexandrium are known to cause large-scale mortality of fish. Thus, the dynamics of these species is important and of concern to scientists, officials, and people in the aquaculture industry. To understand the dynamics of such species, their growth and mortality due to predation need to be assessed. The newly described dinoflagellate Alexandrium pohangense is known to grow slowly, with a maximum autotrophic growth rate of 0.1 d−1. Thus, it may not form bloom patches if its mortality due to predation is high. Therefore, to explore the mortality of A. pohangense due to predation, feeding on this species by the common heterotrophic dinoflagellates Gyrodinium dominans, Gyrodinium moestrupii, Luciella masanensis, Noctiluca scintillans, Oxyrrhis marina, Oblea rotunda, Polykrikos kofoidii, and Pfiesteria piscicida, as well as by the ciliate Tiarina fusus, was examined. None of these potential predators was able to feed on A. pohangense. In contrast, these potential predators were killed and their bodies were dissolved when incubated with A. pohangense cells or cell-free culture filtrates. The survival of G. moestrupii, O. marina, P. kofoidii, and T. fusus on incubation with 10 cells ml−1 of A. pohangense was 20–60%, while that at the equivalent culture filtrates was 20–70%. With increasing A. pohangense cell-concentration (up to 1000 cells ml−1 or equivalent culture filtrates), the survival rate of G. moestrupii, O. marina, P. kofoidii, and T. fusus rapidly decreased. The lethal concentration (LC50) for G. moestrupii, O. marina, P. kofoidii, and T. fusus at the elapsed time of 24 h with A. pohangense cells (cultures of 11.4, 13.3, 1.6, and 3.3 cells ml−1, respectively) was lower than that with A. pohangense filtrates (culture filtrates of 35.5, 30.6, 5.5, and 5.0 cells ml−1, respectively). Furthermore, most of the ciliates and heterotrophic dinoflagellates in the water collected from the coast of Tongyoung, Korea, were killed when incubated with cultures of 1000 A. pohangense cells ml−1 and equivalent culture filtrates. The relatively slow growing A. pohangense may form blooms by reducing mortality due to predation through killing potential protist predators.  相似文献   

16.
BackgroundThe aim of this study was to investigate the association between statin use and survival in a population-based colorectal cancer (CRC) cohort and perform an updated meta-analysis to quantify the magnitude of any association.MethodsA cohort of 8391 patients with newly diagnosed Dukes’ A-C CRC (2009–2012) was identified from the Scottish Cancer Registry. This cohort was linked to the Prescribing Information System and the National Records of Scotland Death Records (until January 2015) to identify 1064 colorectal cancer-specific deaths. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for cancer-specific mortality by statin use were calculated using time dependent Cox regression models. The systematic review included relevant studies published before January 2016. Meta-analysis techniques were used to derive combined HRs for associations between statin use and cancer-specific and overall mortality.ResultsIn the Scottish cohort, statin use before diagnosis (HR = 0.84, 95% CI 0.75–0.94), but not after (HR = 0.90, 95% CI 0.77–1.05), was associated with significantly improved cancer-specific mortality. The systematic review identified 15 relevant studies. In the meta-analysis, there was consistent (I2 = 0%,heterogeneity P = 0.57) evidence of a reduction in cancer-specific mortality with statin use before diagnosis in 6 studies (n = 86,622, pooled HR = 0.82, 95% CI 0.79–0.86) but this association was less apparent and more heterogeneous (I2 = 67%,heterogeneity P = 0.03) with statin use after diagnosis in 4 studies (n = 19,152, pooled HR = 0.84, 95% CI 0.68–1.04).ConclusionIn a Scottish CRC cohort and updated meta-analysis there was some evidence that statin use was associated with improved survival. However, these associations were weak in magnitude and, particularly for post-diagnosis use, varied markedly between studies.  相似文献   

17.
《Cytokine》2007,37(5-6):283-290
The aim of the present study was to investigate which biomarker/s reliably assess severity and mortality early in the sepsis process. In 47 critically-ill patients within the 24 h of septic onset, Interleukins (IL)-8, -1β, -6, -10, and -12p70, tumor necrosis factor-α (TNF-α), procalcitonin (PCT) and C-reactive protein (CRP) were measured in serum. Additionally, CD64 expression was measured in neutrophils. In early sepsis, neutrophil CD64 expression and IL-8 levels are the only biomarkers that increased with sepsis severity, differentiating disease stages: sepsis, severe sepsis and septic shock (p < 0.001). The biomarkers that best evaluate the severity of sepsis (via APACHE II) were CD64, IL-8 and IL-6 (p < 0.01), and the severity of organ failure (via SOFA) were CD64 and IL-8 (p < 0.01). CD64 expression and IL-8 levels were associated with mortality within 28-days (OR = 1.3, p = 0.01 for CD64 and OR = 1.26, p = 0.024 for IL-8 by logistic regression analysis) and ROC curve analysis showed high sensitivity and specificity for predicting sepsis stages and the 28 day mortality. We conclude that there is an early increase of neutrophil CD64 expression and IL-8 levels during sepsis. Based on this single measurement it is possible to reliably assess the stage, detect the severity and predict the 28-day mortality of sepsis.  相似文献   

18.
Shrimp head waste is a major byproduct of crustacean processing in North-eastern Brazil and represents an interesting source of bioactive molecules. Additionally, its use increases the sustainability of processing fishery products. The present study reports a process developed for recovering bioactive molecules from shrimp heads through autolysis. A protein hydrolysate (120 ± 0.4 g) formed by a 9% (w/v) solution was recovered and lyophilized from 1 kg of shrimp heads. Approximately 195 ± 0.5 mg of carotenoids was recovered as an ethanolic extract. The recovery of chitin and chitosan were 25 ± 2 g kg?1 and 17 ± 4 g kg?1 wet processing waste, respectively. Chitosans were characterized by 13C NMR, and FT-IR analysis and exhibited a variable degree of deacetylation (60–80%). Sulfated glycosaminoglycans that exhibited electrophoretic migration similar to mammalian standards were also recovered (79 ± 2 mg kg?1 wet processing waste), and their degradation products suggested the presence of C6-sulfated heparan sulfate. These data point to the feasibility of an integrated process for isolating highly bioactive molecules, such as sulfated- and amino-polysaccharides, with a broad spectrum of applications from shrimp processing waste.  相似文献   

19.
The aim of this study was to investigate the effectiveness of bioaugmentation and transfer of plasmid pWWO (TOL plasmid) to mixed microbial populations in pilot and laboratory scale sequencing batch biofilm reactors (SBBRs) treating synthetic wastewater containing benzyl alcohol (BA) as a model xenobiotic. The plasmid donor was a Pseudomonas putida strain chromosomally tagged with the gene for the red fluorescent protein carrying a green fluorescent protein labeled TOL plasmid, which confers degradation capacity for several compounds including toluene and BA. In the pilot scale SBBR donor cells were disappeared 84 h after inoculation while transconjugants were not detected at all. In contrast, both donor and transconjugant cells were detected in the laboratory scale reactor where the ratio of transconjugants to donors fluctuated between 1.9 × 10?1 and 8.9 × 10?1 during an experimental period of 32 days. BA degradation rate was enhanced after donor inoculation from 0.98 mg BA/min prior to inoculation to 1.9 mg BA/min on the seventeenth day of operation. Survival of a bioaugmented strain, conjugative plasmid transfer and enhanced BA degradation was demonstrated in the laboratory scale SBBR but not in the pilot scale SBBR.  相似文献   

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