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Results for “Environment, Controlled”

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At least 847 records · Page 47Linked to original sources

PubMed2007

Anammox enrichment from different conventional sludges.

Three sets of sequencing batch reactor (SBR) were used for Anammox enrichment from conventional sludges including upflow anaerobic sludge blanket, activated sludge, and anaerobic digestion sludge. After four months of operation, the Anammox activity occurred in all reactors allowing continuous removal of ammonium and nitrite. The morphology of the cultivated Anammox sludge was observed using scanning electron microscope. The photographs showed that the obtained culture was mostly spherical in shape, presumably Anammox culture. There were also filamentous-like bacteria co-existing in the system. Fluorescence in situ hybridization (FISH) analysis using 16S rRNA targeting oligonucleotide probes PLA46 and Amx820 showed that the dominant population developed in all SBRs was hybridized with both PLA46 and Amx820 gene probes. It means that the cultivated biomass in all SBRs was classified in the group of Planctomycetales bacteria with respect to the anaerobic ammonium-oxidizing bacteria, Candidatus Brocadia anammoxidans and Candidatus Kuenenia stuttgartiensis. Numerous time sequences were tested in this experiment. The shortest workable reaction time was found in the range from 5 to 7 h. Good quiescence of sludge was obtained at 30 min of settle period followed by a discharge period of 15 min. A long-term performance showed a near perfect removal of nitrite based on the influent NO2(-)-N concentration of 50-70 mg l(-1). The maximum ammonia removal efficiency was 80% with the influent NH4(+)-N concentration of 40-60 mg l(-1). It is, therefore, concluded that Anammox cultivation from conventional sludges was highly possible under control environment within four months.

Ammonia↗

PubMed2005

A graphic tool for curating molecular interaction networks from the literature.

We propose a graphic tool for curating molecular interaction networks constructed from the literature by information extraction (IE). In order to turn preliminary results from IE into useful biomedical resources, we propose to use a controlled environment in which visualization and IE work synergistically. The usability of the proposed graphic tool is shown with respect to the identification of incorrectly extracted results that are due to the much troubling coordination phenomena in natural language texts. Through the experiment on molecular interactions in Saccaharomyces cerevisiae, we have seen a meaningful increase (from 91.5% to 97.5%) in the number of correctly extracted interaction information.

Computational Biology↗

PubMed2005

Yield enhancement genes: seeds for growth.

Yield is a multifactorial trait, integrating various developmental and physiological processes. Despite this complexity, evidence is mounting that yield can be increased by the genetic modification of single genes. Positive results have been obtained by targeting different yield constituents, indicating that there is ample room for further yield improvement by genetic means. Successful targets include photosynthesis, starch biosynthesis, plant architecture and transcriptional networks controlling plant development. Most of the current data have been obtained in a (semi-)controlled environment and relate to yield calculated on a per plant basis. Demonstrating the ability to transfer these effects to field-grown plants and with reference to yield on a per area unit basis will be a crucial step in establishing the agronomic importance of these findings.

Arabidopsis↗

PubMed2005

Possible impacts of changes in UV-B radiation on North American trees and forests.

Approximately 35 species representing 14 tree genera have been evaluated for responses to UV-B radiation in North America. The best representation has been in the conifers where some 20 species representing three genera have been studied. Overall, about 1/3 of these have demonstrated some deleterious response to UV-B. However, most negative impacts have been observed under controlled environment conditions where sensitivity may be enhanced. Therefore, it seems unlikely that expected levels of ozone depletion will result in direct losses in productivity. However, the role that ambient or enhanced levels of UV-B may play in forest ecosystem processes is more difficult to access. One possible indirect response of forests to changes in UV-B radiation levels could be via alterations in plant secondary metabolites. Increases in phenolics and flavonoids that enhance epidermal UV-screening effectiveness may also influence leaf development, water relations or ecosystem processes such as plant-herbivore interactions or decomposition.

Acclimatization↗

PubMed2006

Modelling the dynamic air-water-sediment coupled fluxes and occurrence of polychlorinated biphenyls in a high altitude lake.

The BIODEP model in terms of atmosphere-lake interactions was developed. The model was applied to an oligotrophic, dimictic high altitude lake (Lake Redo, Pyrenees) for a range of polychlorinated biphenyl (PCB) congeners. High altitude lakes, which receive their contaminant inputs uniquely from the atmosphere through long-range atmospheric transport, provide ideal controlled environments for the study of the interactions between atmospheric depositional and water column biogeochemical processes. The BIODEP model was able to predict dissolved water concentrations and PCB accumulation in the lake sediment within a factor of 2. This shows that the BIODEP model captures the essential processes driving the sink of POPs in high altitude lakes and that POP occurrence in the lake is driven by direct atmospheric inputs with limited influence from the watershed. An important seasonal variability in water column concentrations is predicted which should have important implications in sampling strategies. Furthermore, it is shown that diffusive air-water exchange dominated the PCB dynamics in the lake, especially for the less chlorinated biphenyls.

Air↗

PubMed2005

Ozone sensitivity of currant tomato (Lycopersicon pimpinellifolium), a potential bioindicator species.

The wild tomato species Lycopersicon pimpinellifolium (currant tomato) was exposed to different O3 concentration, both in controlled environment fumigation facilities and in open-top chambers, to assess its sensitivity and to verify its potential as a bioindicator plant. Plants appeared particularly sensitive to O3 at an early stage of growth, responding with typical chlorotic spots within 24 h after exposure to a single pulse of 50 ppb for 3 h, and differentiating peculiar symptoms, such as reddish necrotic stipples, bronzing and extensive necrosis, depending on O3 concentration. Histo-cytochemical investigations with 3,3'-diaminobenzidine, to localize H2O2, and Evans blue, to detect dead cells, suggested that currant tomato sensitivity to O3 could be due to a deficiency in the anti-oxidant pools. The combination of these stainings proved to be useful, either to predict visible symptoms, early before their appearance, and to validate leaf ozone injury.

Biomarkers↗

PubMed2026

Precision UV-B irradiation for flavonoid biofortification in indoor-cultivated Morus nigra: Integrated multi-omics and molecular docking insights.

Precision application of UV irradiation represents an effective strategy for improving the quality of functional food crops under controlled environmental conditions. Morus nigra serves as a significant functional food resource in Xinjiang, with its leaves being rich in diverse bioactive compounds with nutritional and health-promoting properties. In this study, a low-dose UV-B treatment regimen was developed to enhance flavonoids in indoor-cultivated M. nigra without growth penalty. Multi-omics revealed a hormone shift (suppressed auxin vs. activated JA signaling). This triggered transcriptional reprogramming of PAL/4CL and CHS/CYP75B1, redirecting carbon flux towards flavonoid biosynthesis. Transient overexpression of MYB, NAC, and TIFY variants validated this regulatory network. The UV-B-induced NAC upregulated key genes and flavonoids, while different TIFY members showed diverse regulatory effects. Molecular docking predicted that the induced flavonoids had hypoglycemic, antioxidant, and anti-browning potential. This study indicates targeted UV-B as a green biofortification strategy for high-value crops in controlled environments.

Flavonoid biosynthesis↗

PubMed2006

Heterosis of haemolymph analytes of two geographic populations in Chinese shrimp Fenneropenaeus chinensis.

Fenneropenaeus chinensis is distributed along the coasts of the northern seacoast of China and the Korean Peninsula. According to their migration routes, spawning and overwintering places, F. chinensis is divided mainly into three geographic variety populations. These populations represent potentially different genetic resources important to hybridisation breeding programs. To evaluate heterosis of the total protein concentration (PC), haemocyanin concentration (HC), penoloxidase (PO) activity, acid phosphatase (ACP) activity, alkaline phosphatase (ALP) activity and antimicrobial activity (Ua) mating was produced between and within Yellow and Bo sea (YB) population and southern seacoast of Korean Peninsula (SK) population, and the offspring of 49 families was reared to 7.64 g in the controlled environment. The results showed that the content of all haemolymph analytes of SK population was higher than that of YB population, and the immunocompetence in all hybridisations were higher than that in YB male x YB female except of HC in YB male x SK female. Nine of 12 hybridisations had manifested positive heterosis in six haemolymph analytes. Heterosis of SK x YB was all-positive, and this hybridisation was better than YB x SK in HC, PO, ALP activity and Ua. The results suggested that the haemolymph analytes of YB and SK populations had many genetic differences, and hybridisation was an important tool to increase immune reaction and adverse resistance.

Acid Phosphatase↗

PubMed2006

Simulator training in endoscopic hemostasis.

Simulation of upper gastrointestinal (GI) hemorrhage provides the opportunity to practice endoscopic hemostasis without the risk of patient harm and time limitations. Various models have been developed to simulate an acute bleeding source in the upper GI tract to evaluate the feasibility of new endoscopic devices or to practice interventional techniques in a calm and controlled environment. Increasingly available ex vivo models provide this opportunity without the ethical concerns involved with live-animal courses. Validation studies have proven acceptance of ex vivo models and improved clinical performance by repetitive training using these models.

Animals↗

PubMed2004

Numerical simulation of tissue differentiation around loaded titanium implants in a bone chamber.

The application of a bone chamber provides a controlled environment for the study of tissue differentiation and bone adaptation. The influence of different mechanical and biological factors on the processes can be measured experimentally. The goal of the present work is to numerically model the process of peri-implant tissue differentiation inside a bone chamber, placed in a rabbit tibia. 2D and 3D models were created of the tissue inside the chamber. A number of loading conditions, corresponding to those applied in the rabbit experiments, were simulated. Fluid velocity and maximal distortional strain were considered as the stimuli that guide the differentiation process of mesenchymal cells into fibroblasts, chondrocytes and osteoblasts. Mesenchymal cells migrate through the chamber from the perforations in the chamber wall. This process is modelled by the diffusion equation. The predicted tissue phenotypes as well as the process of tissue ingrowth into the chamber show a qualitative agreement with the results of the rabbit experiments. Due to the limited number of animal experiments (four) and the observed inter-animal differences, no quantitative comparison could be made. These results however are a strong indication of the feasibility of the implemented theory to predict the mechano-regulation of the differentiation process inside the bone chamber.

Animals↗

PubMed2004

Stress development during drying of calcium carbonate suspensions containing carboxymethylcellulose and latex particles.

Stress development during drying of coatings produced from aqueous dispersions of calcium carbonate particles in the presence and absence of organic binders was studied using a controlled-environment stress apparatus that simultaneously monitored drying stress, weight loss, and relative humidity. Specifically, the influence of two organic binders on drying stress evolution was investigated: (1) carboxymethylcellulose, a water-soluble viscosifying aid, and (2) a styrene-butadiene latex emulsion of varying glass transition temperature. The stress histories exhibited three distinct regions. First, a period of stress rise was observed, which reflected the capillary tension exerted by the liquid on the particle network. Second, a maximum stress was observed. Third, it was followed by a period of either stress decay or rise depending on the organic species present. Significant differences in stress histories were observed between coatings containing soluble and nonsoluble binders. Maximum drying stresses (sigmamax) of 0.2-0.5 MPa were observed for coatings produced from pure calcium carbonate or calcium carbonate-latex suspensions, whereas coatings with carboxymethylcellulose exhibited substantially higher sigmamax values of 1-2 MPa. Upon drying, these coatings were quite hygroscopic, such that cyclic variations in relative humidity induced large cyclic changes in residual stress.

Journal Article↗

PubMed2005

Soluble organic additive effects on stress development during drying of calcium carbonate suspensions.

The effect of polymer, plasticizer, and surfactant additives on stress development during drying of calcium carbonate particulate coatings was studied using a controlled-environment apparatus that simultaneously monitors drying stress, weight loss, and relative humidity. We found that the calcium carbonate coatings display a drying stress evolution typical of granular films, which is characterized by a sharp capillary-induced stress rise followed by a rapid stress relaxation. The addition of a soluble polymer to the CaCO3 suspension resulted in a two-stage stress evolution process. The initial stress rise stems from capillary-pressure-induced stresses within the film, while the second, larger stress rise occurs due to solidification and shrinkage of the polymeric species. Measurements on the corresponding pure polymer solutions established a clear correlation between the magnitude of residual stress in both the polymer and CaCO3-polymer films to the physical properties of the polymer phase, i.e. its glass transition temperature, T(g), and Young's modulus. The addition of small organic molecules can reduce the residual stress observed in the CaCO3-polymer films; e.g., glycerol, which acts as a plasticizer, reduces the drying stress by lowering T(g), while surfactant additions reduce the surface tension of the liquid phase, and, hence, the magnitude of the capillary pressure within the film.

Calcium Carbonate↗

PubMed2004

Method for measurement of the blood-brain barrier permeability in the perfused mouse brain: application to amyloid-beta peptide in wild type and Alzheimer's Tg2576 mice.

The role of transport exchanges of neuroactive solutes across the blood-brain barrier (BBB) is increasingly recognized. To take full advantage of genetically altered mouse models of neurodegenerative disorders for BBB transport studies, we adapted a brain perfusion technique to the mouse. During a carotid brain perfusion with a medium containing sheep red blood cells and mock plasma, the physiological parameters in the arterial inflow, regional cerebral blood flow (14C-iodoantipyrine autoradiography), ultrastructural integrity of the tissue, barrier to lanthanum, brain water content, energy metabolites and lactate levels remain unchanged. Amyloid-beta peptides (Abeta) were iodinated by lactoperoxidase method. Non-oxidized mono-iodinated Abeta monomers were separated by HPLC (as confirmed by MALDI-TOF spectrometry) and used in transport measurements. Transport of intact 125I-Abeta40 across the BBB was time- and concentration-dependent in contrast to negligible 14C-inulin uptake. In 5-6 months old Alzheimer's Tg2576 mice, Abeta40 BBB transport was increased by >eight-fold compared to age-matched littermate controls, and was mediated via the receptor for advanced glycation endproducts. We conclude the present arterial brain perfusion method provides strictly controlled environment in cerebral microcirculation suitable for examining transport of rapidly and slowly penetrating molecules across the BBB in normal and transgenic mice.

Adenosine Triphosphate↗

PubMed2006

From the combat medic to the forward surgical team: the Madigan model for improving trauma readiness of brigade combat teams fighting the Global War on Terror.

BACKGROUND: Medics assigned to combat units have a notable paucity of trauma experience. Our goal was to provide intense trauma refresher training for the conventional combat medic to better prepare them for combat casualty care in the War on Terror. MATERIALS AND METHODS: Our Tactical Combat Casualty Care Course (TC3) consisted of the following five phases: (1) One and one-half-day didactic session; (2) Half-day simulation portion with interactive human surgical simulators for anatomical correlation of procedures and team building; (3) Half-day of case presentations and triage scenarios from Iraq/Afghanistan and associated skills stations; (4) Half-day live tissue lab where procedures were performed on live anesthetized animals in a controlled environment; and (5) One-day field phase where live anesthetized animals and surgical simulators were combined in a real-time, field-training event to simulate realistic combat injuries, evacuation problems, and mass casualty scenarios. Data collection consisted of surveys, pre- and posttests, and after-action comments. RESULTS: A total of 1317 personnel participated in TC3 from October 2003 through May 2005. Over the overlapping study period from December 2004 to April 2005, 327 soldiers participated in the formal five-phase course. Three hundred four (94%) students were combat medics who were preparing for combat operations in Iraq or Afghanistan. Of those completing the training, 97% indicated their confidence and ability to treat combat casualties were markedly improved. Moreover, of those 140 medics who took the course and deployed to Iraq for 1 year, 99% indicated that the principles taught in the TC3 course helped with battlefield management of injured casualties during their deployment. CONCLUSION: The hybrid training model is an effective method for training medical personnel to deal with modern battle injuries. This course increases the knowledge and confidence of combat medics deploying and fighting the Global War on Terrorism.

Anesthesia↗

PubMed2007

The current role of medical simulation in american urological residency training programs: an assessment by program directors.

PURPOSE: Although medical simulation opportunities are increasingly available, resident training to date has involved primarily hands-on, subjective assessments. The role of simulation and computer based training for urology residents remains unknown. We evaluated the current status of medical simulation among urological training programs in the United States. MATERIALS AND METHODS: An anonymous questionnaire was developed and mailed to the program director at the 119 Accreditation Council for Graduate Medical Education accredited United States urology training programs, and consisted of 17 questions documenting the prior experience of the responder to medical simulation as well as the current status of simulation at their institution. An additional 14 questions sought the responders' opinion of medical simulation in urology training programs. RESULTS: The questionnaire was returned by 41 program directors (35%). Among respondents, access to a laparoscopy simulator was 76%. In comparison, reported access to cystoscopy, ureteroscopy, transurethral resection and percutaneous access simulators was 16%, 21%, 8% and 12%, respectively. Respondents indicated that these simulators were good educational tools, realistic and easy to use. Unanimous agreement was reported for simulation training in residency and that simulators allow practice in a controlled environment. Disagreement was reported about the cost effectiveness, validity and ability of simulators to replace hands-on instruction in the operating room. CONCLUSIONS: Among responders a high level of access to laparoscopic simulators for urology residents is coupled with low levels of access to other endoscopic trainers. Urology residency program directors unanimously recognize a role for simulation training in residency, although the extent to which they may be incorporated remains to be resolved.

Computer Simulation↗

PubMed2004

Innate and adaptive immune requirements for induction of autoimmune demyelinating disease by molecular mimicry.

Molecular mimicry is the main postulated mechanism by which infectious agents induce autoimmune disease. A number of animal models have been utilized to establish a link between molecular mimicry and autoimmunity. However, a model of infectious disease whereby a natural pathogen expressing a known mimic epitope can induce autoimmunity to a known self-antigen leading to clinical autoimmune disease is still lacking. We have engineered a recombinant Theiler's murine encephalomyelitis virus (TMEV) to express an encephalitogenic myelin proteolipid protein PLP139-151 epitope (PLP-TMEV) and a PLP139-151 mimic peptide naturally expressed by Haemophilus influenzae (HI-TMEV). Infection of mice with either PLP-TMEV or HI-TMEV induces early-onset disease that is associated with the activation of cross-reactive PLP139-151-specific immunopathologic CD4+ Th1 cells. Based on results from this model, we hypothesize, due to the considerable degeneracy in the T cell repertoire, that induction of full-blown autoimmune disease via molecular mimicry is a tightly regulated process requiring multiple factors related to the pathogen expressing the potential mimic epitope. In this review, we will discuss how various factors related to the infectious environment control whether or not autoimmune disease is initiated. Contributing factors include the nature of the innate immune response to the pathogen which determines the immunopathologic potential of the induced cross-reactive T cells, the capacity of the mimic epitope to be processed and presented from its natural flanking sequences in the pathogen-encoded protein, the site(s) of the primary infection in the host and the ability of the pathogen to persist, and the potential requirement for multiple infections with the same or different pathogens.

Animals↗

PubMed2004

Using virtual reality to analyze links between handball thrower kinematics and goalkeeper's reactions.

This work investigates the design of a new method to evaluate the importance of visual elements taken into account by a handball goalkeeper facing a thrower. Virtual reality was used to design and reproduce standardised situations in a controlled environment. Under such conditions, it was possible to isolate for investigation one visual element in the thrower's gestures. The goalkeeper's movements were recorded in order to compare his reactions to two separate throws where only one visual element was modified. Our systems allowed us to measure and record the effects of small changes in the thrower's movements. With the numerical values we obtained from our results we were able to come up with a scale of significance for each isolated element. These preliminary results look promising for neuroscience, allowing us to better understand the strategies used in duel situations.

Biomechanical Phenomena↗

PubMed2005

Evaluation of EEG localization methods using realistic simulations of interictal spikes.

Performing an accurate localization of sources of interictal spikes from EEG scalp measurements is of particular interest during the presurgical investigation of epilepsy. The purpose of this paper is to study the ability of six distributed source localization methods to recover extended sources of activated cortex. Due to the frequent lack of a gold standard to evaluate source localization methods, our evaluation was performed in a controlled environment using realistic simulations of EEG interictal spikes, involving several anatomical locations with several spatial extents. Simulated data were corrupted by physiological EEG noise. Simulations involving pairs of sources with the same amplitude were also studied. In addition to standard validation criteria (e.g., geodesic distance or mean square error), we proposed an original criterion dedicated to assess detection accuracy, based on receiver operating characteristic (ROC) analysis. Six source localization methods were evaluated: the minimum norm, the minimum norm weighted by multivariate source prelocalization (MSP), cortical LORETA with or without additional minimum norm regularization, and two derivations of the maximum entropy on the mean (MEM) approach. Results showed that LORETA-based and MEM-based methods were able to accurately recover sources of different spatial extents, with the exception of sources in temporo-mesial and fronto-mesial regions. Several spurious sources were generated by those methods, however, whereas methods using the MSP always located very accurately the maximum of activity but not its spatial extent. These findings suggest that one should always take into account the results from different localization methods when analyzing real interictal spikes.

Algorithms↗