Bioremediation of water contaminated with uranium using Penicillium piscarium

Penicillium piscarium can be indicated as promising in the treatment of sites contaminated with uranium. Thus, this research aimed to analyze the P. piscarium dead biomass in uranium biosorption. This fungus was previously isolated from a highly contaminated uranium mine located in Brazil. Biosorption tests were carried out at pH 3.5 and 5.5 in solutions contaminated with concentrations of 1 to 100 mg/L of uranium nitrate. Our results showed that the dead biomass of P. piscarium was able to remove between 93.2 and 97.5% uranium from solutions at pH 3.5, at the end of the experiment, the pH of the solution increased to values above 5.6. Regarding the experiments carried out in solutions with pH 5.5, the dead biomass of the fungus was also able to remove between 38 and 92% uranium from the solution, at the end of the experiment, the pH of the solution increased to levels above 6.5. The analysis of electron microscopy, Energy-dispersive spectroscopy, and X-ray fluorescence demonstrated the high concentration of uranium precipitated on the surface of the fungal biomass. These results were impressive and demonstrate that the dead biomass of P. piscarium can be an important alternative to conventional processes for treating water contaminated with heavy metals, and we hope that these ecofriendly, inexpensive, and effective technologies be encouraged for the safe discharge of water from industrial activities.     

The effects of breaking or bending the stems of two rhizomatous plants, Phragmites australis and Miscanthus sacchariflorus, on their communities

To understand the effects of disturbance on vegetation, bending and cutting experiments were conducted on two rhizomatous plant species, Phragmites australis and Miscanthus sacchariflorus, in a floodplain area of the Arakawa River, Japan. The plants were damaged in the late development growth stage on 3 August 2004 (August disturbance) and in the middle development growth stage on 29 June 2005 (June disturbance). The severity of the damage was evaluated based on shoot morphology and belowground biomass. The recoveries of the two plants from the flood-like artificial disturbance were compared with undisturbed stands. The morphological response of the shoot was higher after the June disturbance than after the August disturbance in both plants. In contrast, the recovery of belowground biomass in P. australis at the end of the growth season was higher after the August disturbance (87 and 72% for bending and cutting, respectively) compared with the June disturbance (84 and 60% for the same). The recoveries in M. sacchariflorus for the two disturbances showed the opposite trend (73 and 59% for bending and cutting, respectively, after the August disturbance, and 90 and 73% after the same disturbance in June). The study demonstrated that an event like flooding, whether it is breaking or bending, will cause greater damage if it occurs at the late development growth stage in M. sacchariflorus compared with the middle development growth stage. In contrast, P. australis tolerated disturbances up to a certain magnitude; after that, the effect was more severe in the middle development growth stage compared with late development growth stage.     

In vitro and in vivo studies of cancer cell behavior under nutrient deprivation

Cancer cells are confronted with nutrient deprivation because of high proliferation rate, especially at the early stage of their development. There is a frequent assumption that nutrient deprivation decreases the basal activity of cancer cells. Contrarily, there are recent evidence suggesting that cancer cells are able to modulate signaling pathways to adapt with new condition and continue their survival. This property of cancer cells is believed to be one of the prerequisites for cancer progression and chemoresistance. Moreover, recent experiments show that serum starvation in vitro as a mimic situation of nutrient deprivation in vivo triggers different signaling pathways leading to changes in cancer cell behavior, which may interfere with experimental results. Considering these facts, a better understanding of the effect of nutrient deprivation on cancer cell behavior will help us to give more accurate conclusions regarding results of in vitro studies and also to develop new strategies to treat different cancers in vivo.     

Dorso-ventral polarity of the zebrafish embryo is distinguishable prior to the onset of gastrulation

We describe a set of observations on developing zebrafish embryos and discuss the main conclusions they allow:(1) the embryonic dorso-ventral polarity axis is morphologically distinguishable prior to the onset of gastrulation; and (2) the involution of deep layer cells starts on the prospective dorsal side of the embryo. An asymmetry can be distinguished in the organization of the blastomeres in the zebrafish blastula at the 30% epiboly stage, in that one sector of the blastoderm is thicker than the other. Dye-labelling experiments with DiI and DiO and histological analysis allow us to conclude that the embryonic shield will form on the thinner side of the blastoderm. Therefore, this side corresponds to the prospective dorsal side of the embryo. Simultaneous injections of dyes on the thinner side of the blastoderm and on the opposite side show that involution of deep layer cells during gastrulation starts at the site at which the embryonic shield will form and extends from here to the prospective ventral regions of the germ ring.     

Osmolarity and composition of cell culture media affect further development and survival in zebrafish embryos

With the aim of carrying out chimaerism and somatic cell-midblastula transition (MBT) embryos co-culture experiments in freshwater fish species, we evaluated the effect of osmolarity and composition of two media commonly used in cell fish culture on MBT zebrafish embryos and their further development and survival. To this end, wild zebrafish dechorionated embryos in midblastula stage were cultured for 6 days (Experiment 1: 189 embryos) or 1 h (Experiment 2: 150 embryos) in three different media: Hanks' 10% (H-10), 35 mOsm; Hanks' 100% (CH), 315 mOsm; and L-15 with serum (L-15: 315 mOsm). High osmolarity affected the survival rate (6 days: L-15: 45.1% v. CH: 72.34% v. H-10: 100%, P < 0.05; after 6 days: 0% both in L-15 and CH) and slowed their developmental timing. Embryos showed tail deformation (curly) as well as body paralysis at 48 h when they showed tail movements at 28 h. Differences in tail deformation were observed between high-osmolarity groups (CH: 85.10% v. L-15: 98.04%; P < 0.05). In Experiment 2, no effects on survival rate were observed. Teratogenic effects were only observed in L-15 (L-15: 12.98% v. CH: 0%; P< 0.05). Loss of motility was not detected in any group at 48 h. Optimum osmolar condition for cultured cells and also embryonic cells is around 315 mOsm and so, during chimaerism experiments (usually practised at MBT stage), present results indicate that midblastula embryos can acceptably bear the effects caused by 315 mOsm (CH) for 1 h, even though this involves a certain delay in developmental timing.     

Comparison in men of physiological responses to exercise of increasing intensity at low and moderate ambient temperatures

In six male subjects the sweating thresholds, heart rate (fc), as well as the metabolic responses to exercise of different intensities [40%, 60% and 80% maximal oxygen uptake (VO2max)], were compared at ambient temperatures (Ta) of 5 degrees C (LT) and 24 degrees C (MT). Each period of exercise was preceded by a rest period at the same temperature. In LT experiments, the subjects rested until shivering occurred and in MT experiments the rest period was made to be of exactly equivalent length. Oxygen uptake (VO2) at the end of each rest period was higher in LT than MT (P less than 0.05). During 20-min exercise at 40% VO2max performed in the cold no sweating was recorded, while at higher exercise intensities sweating occurred at similar rectal temperatures (Tre) but at lower mean skin (Tsk) and mean body temperatures (Tb) in LT than MT experiments (P less than 0.001). The exercise induced VO2 increase was greater only at the end of the light (40% VO2max) exercise in the cold in comparison with MT (P less than 0.001). Both fc and blood lactate concentration [1a]b were lower at the end of LT than MT for moderate (60% VO2max) and heavy (80% VO2max) exercises. It was concluded that the sweating threshold during exercise in the cold environment had shifted towards lower Tb and Tsk. It was also found that subjects exposed to cold possessed a potentially greater ability to exercise at moderate and high intensities than those at 24 degrees C since the increases in Tre, fc and [1a]b were lower at the lower Ta.     

Changes in the activation state of rubisco in bean leaves in relation to recovery of photosynthetic activity after various treatments

Changes in the activation level of rubisco from bean leaves were studied by measuring carboxylation rates after either a prolonged period in the dark after photoinhibitory treatment. Plants kept for 11 h in darkness were subjected to three stages of strong irradiance: stage I, photosynthesis in air; stage II, exposure in1% O₂ and CO₂-free N₂; stage III, reintroduction of air. Decrease in the rate of CO₂ uptake at stage III are due to photoinhibition. From the end of stage I to stage III, initial carboxylase activity, measured in extracts, exhibited large variations whereas changes for total activity were much smaller. Initial activity was four times lower at stage II compared to stage I. It increased in several minutes to high values at stage III where rates of CO₂ uptake were attained more gradually. No large amount of ribulose 1–5 bisp phosphate (RuBP) appeared to be bound to inactive enzyme at stage II. When darkened leaves were illuminated (stage I) the increase of both initial and total activity was slow and parallel to disappeance of the inhibitor carboxyarabinitol-1-phosphate (CA1P). Conversely, increase of CO₂ uptake rate was more rapid.     

Formation of extensor digitorum muscle proportions before and after birth

Studies on the formation of the extensor digitorum muscle morphological characteristics were carried out on material of 85 human fetuses (42 males and 43 females), 16 to 36 weeks old, and 45 adults (31 males and 14 females). Intermediary conclusions were drawn on probable changes occurring in the morphological formation of the muscle after birth, as a result of comparing proportions of the muscle at the fetal stage with its form in adults. In this work, the anthropometric method of study and statistical analysis of results have been applied. Analysis of the results in the fetal group has shown that all metrical characteristics of the muscle reach their maximum values at the end of the investigated ontogenetic space. This is, naturally, a consequence of evolution and growth of all fetal body measures, including elongation of forearms. However, the evolution of the individual muscle characteristics is not regular and though the direction of this growth is similar, its extent varies, and also differs slightly in sexual groups. Comparison of the values of muscle indices for 9 month old fetuses with the same indices for adults shows that relative dimensions of all investigated muscular characteristics decrease during the post-natal period except the relative length of the tendon.     

Some effects of dexamethasone on nucleic acid metabolism in skin of Merino sheep

The effects of 8-day intravenous infusions of dexamethasone on deoxyribonucleic and ribonucleic acid metabolism have been examined in the skin of the Merino sheep. In two separate experiments, depilatory doses of dexamethasone (8.4 mg kg-0.75 body weight) were shown to inhibit the [3H]thymidine incorporation into DNA in the skin by about 80%. In the presence of excess thymidine the amount of radioactivity in DNA at the end of infusion decreased to about 50% of the pretreatment values. The incorporation of [3H]uridine into RNA in the skin was not affected. Decreases in the wet weight, DNA and RNA contents of skin were observed at the end of the dexamethasone infusion. In two experiments, wool growth was reduced to 36 +/- 9% (s.e.m.) and 52 +/- 8% of the respective pretreatment values. The results suggest that the dexamethasone caused a reduction in the wool growth by inhibiting DNA biosynthesis of wool follicle cells.     

Comparison of Alexa Fluor<Superscript>®</Superscript> and CyDye<Superscript>™</Superscript> for practical DNA microarray use

Microarrays are a powerful tool for comparison and understanding of gene expression levels in healthy and diseased states. The method relies upon the assumption that signals from microarray features are a reflection of relative gene expression levels of the cell types under investigation. It has previously been reported that the classical fluorescent dyes used for microarray technology, Cy3 and Cy5, are not ideal due to the decreased stability and fluorescence intensity of the Cy5 dye relative to the Cy3, such that dye bias is an accepted phenomena necessitating dye swap experimental protocols and analysis of differential dye affects. The incentive to find new fluorophores is based on alleviating the problem of dye bias through synonymous performance between counterpart dyes. Alexa Fluor 555 and Alexa Fluor 647 are increasingly promoted as replacements for CyDye in microarray experiments. Performance relates to the molecular and steric similarities, which will vary for each new pair of dyes as well as the spectral integrity for the specific application required. Comparative analysis of the performance of these two competitive dye pairs in practical microarray applications is warranted towards this end. The findings of our study showed that both dye pairs were comparable but that conventional CyDye resulted in significantly higher signal intensities (P < 0.05) and signal minus background levels (P < 0.05) with no significant difference in background values (P > 0.05). This translated to greater levels of differential gene expression with CyDye than with the Alexa Fluor counterparts. However, CyDye fluorophores and in particular Cy5, were found to be less photostable over time and following repeated scans in microarray experiments. These results suggest that precautions against potential dye affects will continue to be necessary and that no one dye pair negates this need.     

Biphasic changes in relaxation following reperfusion after myocardial ischemia

The present study provides evidences of left ventricular diastolic alterations following reperfusion in a model of global ischemia. Isolated perfused rabbit and rat hearts, were subjected to ischemia for 15 and 20 min respectively, followed by 30 min of reperfusion. In rabbit heart at the end of the reperfusion period, isovolumic left ventricular developed pressure (LVDP) and +dP/dt_max stabilized at 55 ± 3% and 60 ± 2% of preischemic values respectively and, in rat heart LVDP = 61 ± 8% and +dP/dt_max = 57 ± 9% of preischemic values. Stunned heart was then obtained from both species. Left ventricular end diastolic pressure (LVEDP) values stabilized at the end of reperfusion period at values higher than preischemic conditions in both species (38.9 ± 4.4 mmHg and 30.3 ± 3.1 mmHg in rabbit and rat respectively). The time constant of relaxation (T) increased early in reperfusion in both species, but then decreased and stabilized at the end of reperfusion period at values lower than preischemic values. The ratio between both maximal velocities (+P/-P), also showed a transitory impairment in relaxation, followed by normalization and stabilization at values lower than preischemic values. This biphasic pattern in relaxation was detected in both species. The changes in relaxation were dissociated from the diastolic compliance and could be the result of a transitory calcium overload and/or sarcoplasmic reticulum dysfunction. The faster myocardial relaxation at the end of reperfusion period is consistent with the decreased myofilament sensitivity, which characterizes the stunned myocardium.     

Application of Modeling to Scale-up Dissolution in Pharmaceutical Manufacturing

Liquid mixing scale-up in pharmaceutical industry has often been based on empirical approach in spite of tremendous understanding of liquid mixing scale-up in engineering fields. In this work, we attempt to provide a model-based approach to scale-up dissolution process from a 2 l lab-scale vessel to a 4,000 l scale vessel used in manufacturing. Propylparaben was used as a model compound to verify the model predictions for operating conditions at commercial scale that would result in similar dissolution profile as observed in lab scale. Geometric similarity was maintained between both of the scales to ensure similar mixing characteristics. We utilized computational fluid dynamics (CFD) to ensure that the operating conditions at laboratory and commercial scale will result in similar power per unit volume (P/V). Utilizing this simple scale-up criterion of similar P/V across different scales, results obtained indicate fairly good reproducibility of the dissolution profiles between the two scales. Utilization of concepts of design of experiments enabled summarizing scale-up results in statistically meaningful parameters, for example −90% dissolution in lab scale at a given time under certain operating conditions will result in 75–88% at commercial scale with 95% confidence interval when P/V is maintained constant across the two scales. In this work, we have successfully demonstrated that scale-up of solid dissolution can be done using a systematic process of lab-scale experiments followed by simple CFD modeling to predict commercial-scale experimental conditions.     

Chemopreventive action of Phyllanthus urinaria Linn on DMBA-induced skin carcinogenesis in mice

The inhibition of tumor incidence by hydro-alcoholic extract of the whole plant of P. urinaria was evaluated in 6-7 weeks old female albino mice on two-stage process of skin carcinogenesis induced by a single application of 7,12-dimethylbenz(a)anthracene (50 microg/50 microl of acetone), and 2 weeks later, promoted by repeated application of croton oil (1% in acetone/three times a week) till the end of the experiment (15 weeks). Topical application of the extract at a dose of 5 mg/kg body weight/day for 15 weeks at the peri-initiational stage (i.e., 7 days before and 7 days after DMBA application), promotional stage (i.e., from the time of croton oil application) and both peri and post-initiational stages (i.e., 7 days prior to DMBA application and continued till the end of the experiment) on the shaven backs of the mice recorded a significant reduction in tumor incidence to 50, 33.3 and 16.7% respectively in comparison to the control (i.e., the mice treated with DMBA and croton oil only) where tumor incidence was found to be 81.8%. The average number of papillomas per mouse was also significantly reduced. The results suggest a possible chemopreventive property of P. urinaria against DMBA-induced skin papillomagenesis in mice.     

Diamondback moth resistance to Bacillus thuringiensis transgenic canola: evaluation of refugia size with non-recessive resistant insects

Abstract:  Current recommendations to delay the evolution of resistance to Bacillus thuringiensis crops are that a minimum of 5–50% of a crop-growing region should include non- B. thuringiensis varieties as refuges. These recommendations are based in part on the assumption that resistance will be inherited as a recessive trait. Laboratory microcosm experiments are described with transgenic canola expressing Cry1Ac and a non-recessive Cry1Ac resistant population of the diamondback moth Plutella xylostella , in which the effect of different sizes of refugia (0%, 20% and 50%) on resistance was compared over five generations. The LC₅₀ values for Cry1Ac increased markedly in the P. xylostella sub-populations with 0% (>100-fold) and 20% refugia (>35-fold) but showed little change (less than fivefold increase) with 50% refugia. The results support the idea that relatively high levels of refugia (non- B. thuringiensis varieties) may be required where resistance is not functionally recessive at the level of toxin expressed in the B. thuringiensis crop.     

Cross sectional longitudinal study of spot morning urine protein:creatinine ratio, 24 hour urine protein excretion rate,glomerular filtration rate,and end stage renal failure in chronic renal disease in patients without diabetes.

OBJECTIVE: To evaluate whether the protein:creatinine ratio in spot morning urine samples is a reliable indicator of 24 hour urinary protein excretion and predicts the rate of decline of glomerular filtration rate and progression to end stage renal failure in non-diabetic patients with chronic nephropathy. DESIGN: Cross sectional correlation between the ratio and urinary protein excretion rate. Univariate and multivariate analysis of baseline predictors, including the ratio and 24 hour urinary protein, of decline in glomerular filtration rate and end stage renal failure in the long term. SETTING: Research centre in Italy. SUBJECTS: 177 non-diabetic outpatients with chronic renal disease screened for participation in the ramipril efficacy in nephropathy study. MAIN OUTCOME MEASURES: Rate of decline in filtration rate evaluated by repeated measurements of unlabelled iohexol plasma clearance and rate of progression to renal failure. RESULTS: Protein:creatinine ratio was significantly correlated with absolute and log transformed 24 hour urinary protein values (P = 0.0001 and P < 0.0001, respectively.) Ratios also had high predictive value for rate of decline of the glomerular filtration rate (univariate P = 0.0003, multivariate P = 0.004) and end stage renal failure (P = 0.002 and P = 0.04). Baseline protein:creatinine ratios and rate of decline of the glomerular filtration rate were also significantly correlated (P < 0.0005). In the lowest third of the protein:creatinine ratio (< 1.7) there was 3% renal failure compared with 21.2% in the highest third (> 2.7) (P < 0.05). CONCLUSIONS: Protein:creatinine ratio in spot morning urine samples is a precise indicator of proteinuria and a reliable predictor of progression of disease in non-diabetic patients with chronic nephropathies and represents a simple and inexpensive procedure in establishing severity of renal disease and prognosis.     

Enzymic hydrolysis of lignocellulosic materials: I. Models for the hydrolysis process--a theoretical study

At the end of an enzymic hydrolysis process involving a solid lignocellulosic substrate, enzymes are found both in solution and absorbed to the substrate residue. Removal of residue from the system will result in loss of some of the enzymes, the extent of which will depend on the design of the process. To minimize enzyme loss, a study has been conducted in which six process models have been formulated and an enzyme loss function derived for each model based on the total amount of enzymes lost through residue removal. Model 1 is a reference model, characterized by an uninterrupted hydrolysis throughout the entire hydrolysis period. The residue is then washed in order to recover both sugar and adsorbed enzymes before the residue is discarded. Models 2-6 are all characterized by the removal of hydrolysate three times during the process, recirculation of dissolved and adsorbed enzymes to various points in the process and selection of a stage at which the residue is removed. The following conclusions could be drawn from the derived enzyme loss functions: Increased enzyme adsorption leads to increased enzyme loss.The enzyme loss decreases if the solid residue is removed late in the process.Both adsorbed and dissolved enzymes should be introduced at the starting point of the process. This is particularly important for dissolved enzymes. Three models were chosen for experimental studies, which are reported in a second, accompanying article. The experimental results obtained are compared with the theoretical study reported here.     

Modelling growth of brown trout, Salmo trutta, in terms of weight and energy units

1. The chief objectives were: (i) to compare two growth models, one based on weight and the other on energy, using the same data set for the analyses; (ii) to discover if weight and energy units can be simply interchanged for growth assessment. The data set was for 183 brown trout, Salmo trutta (live weight 1–300 g), fed to satiation on shrimps, Gammarus pulex, and grown individually over 42 days at constant temperatures (range 3.8–20.4 °C). 2. Rates of change in weight or energy content, and final weight or energy content at the end of 42 days growth, were estimated from the models and were excellent fits to the experimental data (P < 0.001). The shape of the temperature relationship for rates of change or final values was triangular for the weight model and curvilinear for the energetics model. Optimum temperatures for growth according to the weight and energetics models were 13.1 and 13.9 °C, respectively, for rates of change and 13.1 and 13.5 °C, respectively, for final values. When the growth period was extended to 100 and then 300 days, the triangular relationship and optimum temperature remained the same for the weight model, but the curvilinear relationship became more triangular for the energetics model and the optimum temperature identical to that in the weight model. The relationship between gross efficiency and temperature also differed in shape between the two models but maximum efficiencies occurred at a similar value of 9 ± 0.1 °C (18 and 32% for weight and energetics models). As fish weight increased, gross efficiency remained constant in terms of energy units, but decreased markedly in terms of weight. 3. These comparisons showed that different conclusions can be drawn from the two models, even if the same data set was analysed. There was a close relationship between initial wet weight and energy content for stock trout used in the experiments, but the relationship was not so close at the end of the experiments, and interchangeability of units could no longer be assumed. A variable error, often as high as 10–12%, would occur if the relationship for initial values was used to predict one unit from the other. Therefore, weight and energy units cannot be simply interchanged for growth assessment, especially in comparisons for trout of different sizes.     

The Use of Restriction Endonucleases to Measure Mitochondrial DNA Sequence Relatedness in Natural Populations. I. Population Structure and Evolution in the Genus Peromyscus

In this study we introduce to natural population analysis a molecular technique that involves the use of restriction endonucleases to compare mitochondrial DNA (mtDNA) sequences. We have examined the fragment patterns produced by six restriction endonucleases acting upon mtDNA isolated from 23 samples of three species of the rodent Peromyscus. Our observations confirm the following conclusions derived from previous experiments with laboratory animals: (1) mtDNA within an individual homogeneous; (2) at least the majority of mtDNA present in an individual is inherited from the female parent. Our experiments demonstrate for the first time that there is detectable heterogeneity in mtDNA sequences within and among natural geographic populations of a species and that this heterogeneity can readily be used to estimate relatedness between individuals and populations. Individuals collected within a single locale show less than 0.5% sequence divergence, while those collected from conspecific populations separated by 50 ti 500 miles differ by approximately 1.5%. The mtDNAs of the closely related sibling species P. polionotus and P. maniculatus differ from each other by 13 to 17%; nonsibling species differ by more than 20%. Qualitative and quantitative approaches to analysis of digestion patterns are suggested. The results indicate that restriction analysis of mtNDA may become the most sensitive and powerful technique yet available for reconstructing evolutionary relationships among conspecific organisms.     

Effect of rice plants on CH4 production,transport, oxidation and emission in rice paddy soil

To understand the integrated effects of rice plants (variety Wuyugeng 2) on CH₄ emission during the typical rice growth stage, the production, oxidation and emission of methane related to rice plants were investigated simultaneously through laboratory and greenhouse experiments. CH₄ emission was significantly higher from the rice planted treatment than from the unplanted treatment. In the rice planted treatment, CH₄ emission was higher at tillering stage than at panicle initiation stage. An average of 36.3% and 54.7% of CH₄ produced was oxidized in the rhizosphere at rice tillering stage and panicle initiation stage, respectively, measured by using methyl fluoride (MF) technique. In the meantime, CH₄ production in the planted treatments incubated under O₂-free N₂ condition was reduced by 44.9 and 22.3%, respectively, compared to unplanted treatment. On the contrary, the presence of rice plants strongly stimulated CH₄ production by approximately 72.3% at rice ripening stage. CH₄ emission through rice plants averaged 95% at the tillering stage and 89% at the panicle initiation stage. Based on these results, conclusions are drawn that higher CH₄ emission from the planted treatment than from unplanted treatment could be attributed to the function of rice plants for transporting CH₄ from belowground to the atmosphere at tillering and panicle initiation stage, and that a higher CH₄ emission at tillering stage than at panicle initiation stage is due to the lower rhizospheric CH₄ oxidation and more effective transport mediated by rice plants.