[Effects of aroma massage on pruritus, skin pH, skin hydration and sleep in elders in long-term care hospitals].

PubMed

Roh, So Young; Kim, Kye Ha

2013-12-01

The purpose of this study was to examine the effects of aroma massage on pruritus, skin pH, skin hydration and sleep in elders in long-term care hospitals. The participants were elders over 65 years old admitted to long-term care. They were assigned to the experimental group (26) or control group (28). Data were collected from May to August, 2012. Visual Analogue Scale and Verran and Snyder-Halpern Sleep scale were used to identify levels of pruritus and sleep. A skin-pH meter and moisture checker were used to measure skin pH and skin hydration. Aroma massage was performed three times a week for 4 weeks for elders in the experimental group. The data were analyzed using the SPSS Win 17.0 program. There were significant differences in pruritus, skin pH and skin hydration between the two groups. However there was no significant difference in sleep. The results indicate that aroma massage is effective in reducing pruritus, skin pH and increasing skin hydration in elders. Therefore, this intervention can be utilized in clinical practice as an effective nursing intervention to reduce pruritus in elders in long-term care hospitals.

Predictors of Very Late Events After Percutaneous Mitral Valvuloplasty in Patients With Mitral Stenosis.

PubMed

Jorge, Elisabete; Pan, Manuel; Baptista, Rui; Romero, Miguel; Ojeda, Soledad; Suárez de Lezo, Javier; Faria, Henrique; Calisto, João; Monteiro, Pedro; Pêgo, Mariano; Suárez de Lezo, José

2016-06-15

Data on long-term outcomes of percutaneous mitral valvuloplasty (PMV) are still scarce. In addition, the persistence of pulmonary hypertension (PH) after PMV is a complication for which mechanisms and prognostic implications are unclear. Our aims were (1) to report the long-term outcomes of patients with rheumatic mitral stenosis treated with PMV; (2) to determine the risk factors for long-term poor outcomes; and (3) to analyze the prevalence and predictors of persistent PH. We prospectively enrolled 532 patients who underwent PMV from 1987 to 2011 at 2 hospitals. The following end points were assessed after PMV: all-cause mortality, mitral reintervention, a composite end point of all-cause mortality and mitral reintervention, and PH persistence. Survival status was available for 97% patients; the median follow-up was 10 years (interquartile range 4 to 18 years). Procedural success was achieved in 85% patients. During the follow-up, 21% patients died and 27% required mitral reintervention. Before PMV, 74% patients had PH that persisted after PMV in 45% of patients (p <0.001). Unfavorable valve anatomy (Wilkins score >8) and post-PMV mean pulmonary arterial pressure (PAP) were independent predictors of all-cause mortality, mitral reintervention, and the composite end point. Post-PMV mean PAP was significantly correlated with a mitral valve area (MVA) <2.5 cm(2) (p <0.001); in addition, on the echocardiographic follow-up, MVA was an independent predictor of systolic PAP (p <0.001). In conclusion, PMV represents an advantageous therapeutic option for patients with mitral stenosis in terms of long-term outcomes. Unfavorable valve anatomy and persistent PH were the most important predictors of long-term outcomes. The persistence of PH is associated with the MVA obtained after PMV. Copyright © 2016 Elsevier Inc. All rights reserved.

Diurnal and seasonal variations of pH for a year in the western subarctic North Pacific observed by using a hybrid pH sensor

NASA Astrophysics Data System (ADS)

Nakano, Yoshiyuki; Fujiki, Tetsuichi; Kimoto, Katsunori; Miwa, Tetsuya

2017-04-01

Ocean acidification has many far reaching impacts on plankton community in the ocean. There is great need of quality instrumentation to assess and monitor the changing seawater pH. To meet the need, we have developed the in situ high accurate pH sensor (Hybrid pH sensor: HpHS) for the long-term seawater pH monitoring to participate the Wendy Schmidt Ocean health XPRIZE. The HpHS has two types of pH sensors (i.e. potentiometric pH sensor and spectrophotometric pH sensor). The spectrophotometric pH sensor can measure pH correctly and stably, however it needs large power consumption and a lot of reagents in a long period of observation. The pH sensor used m-cresol purple (mCP) as an indicator of pH. On the other hand, although the potentiometric pH sensor is low power consumption and high-speed response (within 10 seconds), drifts in the pH of the potentiometric measurements may possibly occur for a long-term observation. The HpHS can measure in situ pH correctly and stably combining advantage of both pH sensors. The HpHS is correcting the value of the potentiometric pH (measuring frequently) by the value of the spectrophotometric pH (measuring less frequently). It is possible to calibrate in situ with Tris buffer or CRM on the spectrophotometric pH sensor. Therefore, the drifts in the value of potentiometric pH measurements can be compensated using the pH value obtained from the spectrophotometric pH measurements. Thereby, the HpHS can measure accurately the value of pH over a long period of time with low power consumption. In order to understand the seasonal and inter-annual variabilities of biogeochemical cycles and ecosystems, ship-based studies have been carried out since 1997 at time-series station K2 (47oN, 160oE) in the subarctic western North Pacific, which is a region with progression of ocean acidification. However, the ship-based studies of the open ocean have been limited in their ability to conduct high-frequency observations for understanding the biogeochemical cycles and ecosystems. To overcome the problem, we developed a hybrid profiling buoy system. The HpHS was attached to a remote automatic water sampler (200m) in the buoy system in July 2015. We recovered the buoy system in June 2016 and succeeded in observing seawater pH every four hours for a year. Here, we show an overview of the diurnal and seasonal variations of pH for a year at station K2. In addition, we examine a relationship between the pH variations and marine calcifiers recovered by the sediment trap during the same period.

ISFET sensor evaluation and modification for seawater pH measurement

NASA Astrophysics Data System (ADS)

Martz, T. R.; Johnson, K. S.; Jannasch, H.; Coletti, L.; Barry, J.; Lovera, C.

2008-12-01

In the future, short-term cycles (daily to subannual) and long-term trends (annual and greater) in the carbonate system will be observed by autonomous sensors operating from a variety of platforms (e.g., moorings, profiling floats, AUVs, etc.). Of the four carbonate parameters, pH measurement has the longest history of development - yet robust autonomous sensing techniques remain elusive due to a catalog of technical challenges. Existing commercial sensor technologies generally do not meet the stringent demands of accuracy, long-term stability, low power, pressure tolerance, resistance to biofouling, and ease of use required by the oceanographic community. We report here on some recent advances in Ion Sensitive Field Effect Transistor (ISFET) technology that may open the door for more widespread autonomous seawater pH measurements. Much of our work has focused on applications of the Honeywell Durafet pH sensor, a product designed for industrial process control. Initial results from laboratory testing and deployments in the MBARI test tank and near shore moorings will be presented. Sensor calibration techniques will be addressed. Applications of now-available off-the-shelf sensors including shipboard underway measurement, shallow water mooring deployment, and a gas controlled seawater aquarium for pH perturbation experiments will be discussed. We hope that an ongoing collaboration between MBARI and Honeywell will result in a commercially available product, designed specifically for oceanographic applications, within the next several years.

Pulmonary Hypertension in Bronchopulmonary Dysplasia

PubMed Central

Berkelhamer, Sara K.; Mestan, Karen K.; Steinhorn, Robin H.

2013-01-01

Pulmonary hypertension (PH) is a common complication of neonatal respiratory diseases including bronchopulmonary dysplasia (BPD), and recent studies have increased awareness that PH worsens the clinical course, morbidity and mortality of BPD. Recent evidence indicates that up to 18% of all extremely low birth weight infants will develop some degree of PH during their hospitalization, and the incidence rises to 25–40% of infants with established BPD. Risk factors are not yet well understood, but new evidence shows that fetal growth restriction is a significant predictor of PH. Echocardiography remains the primary method for evaluation for BPD-associated PH, and the development of standardized screening timelines and techniques for identification of infants with BPD-associated PH remains an important ongoing topic of investigation. The use of pulmonary vasodilator medications such as nitric oxide, sildenafil, and others in the BPD population is steadily growing, but additional studies are needed regarding their long-term safety and efficacy. PMID:23582967

Parastomal hernias after radical cystectomy and ileal conduit diversion

PubMed Central

Donahue, Timothy F.

2016-01-01

Parastomal hernia, defined as an "incisional hernia related to an abdominal wall stoma", is a frequent complication after conduit urinary diversion that can negatively impact quality of life and present a clinically significant problem for many patients. Parastomal hernia (PH) rates may be as high as 65% and while many patients are asymptomatic, in some series up to 30% of patients require surgical intervention due to pain, leakage, ostomy appliance problems, urinary obstruction, and rarely bowel obstruction or strangulation. Local tissue repair, stoma relocation, and mesh repairs have been performed to correct PH, however, long-term results have been disappointing with recurrence rates of 30%–76% reported after these techniques. Due to high recurrence rates and the potential morbidity of PH repair, efforts have been made to prevent PH development at the time of the initial surgery. Randomized trials of circumstomal prophylactic mesh placement at the time of colostomy and ileostomy stoma formation have shown significant reductions in PH rates with acceptably low complication profiles. We have placed prophylactic mesh at the time of ileal conduit creation in patients at high risk for PH development and found it to be safe and effective in reducing the PH rates over the short-term. In this review, we describe the clinical and radiographic definitions of PH, the clinical impact and risk factors associated with its development, and the use of prophylactic mesh placement for patients undergoing ileal conduit urinary diversion with the intent of reducing PH rates. PMID:27437533

Effect of altitude on brain intracellular pH and inorganic phosphate levels

PubMed Central

Shi, Xian-Feng; Carlson, Paul J.; Kim, Tae-Suk; Sung, Young-Hoon; Hellem, Tracy L.; Fiedler, Kristen K.; Kim, Seong-Eun; Glaeser, Breanna; Wang, Kristina; Zuo, Chun S.; Jeong, Eun-Kee; Renshaw, Perry F.; Kondo, Douglas G.

2015-01-01

Normal brain activity is associated with task-related pH changes. Although central nervous system syndromes associated with significant acidosis and alkalosis are well understood, the effects of less dramatic and chronic changes in brain pH are uncertain. One environmental factor known to alter brain pH is the extreme, acute change in altitude encountered by mountaineers. However, the effect of long-term exposure to moderate altitude has not been studied. The aim of this two-site study was to measure brain intracellular pH and phosphate-bearing metabolite levels at two altitudes in healthy volunteers, using phosphorus-31 magnetic resonance spectroscopy (31P-MRS). Increased brain pH and reduced inorganic phosphate (Pi) levels were found in healthy subjects who were long-term residents of Salt Lake City, UT (4720 ft/1438 m), compared with residents of Belmont, MA (20 ft/6 m). Brain intracellular pH at the altitude of 4720 ft was more alkaline than that observed near sea level. In addition, the ratio of inorganic phosphate to total phosphate signal also shifted toward lower values in the Salt Lake City region compared with the Belmont area. These results suggest that long-term residence at moderate altitude is associated with brain chemical changes. PMID:24768210

Model-Based Analysis of the Long-Term Effects of Fertilization Management on Cropland Soil Acidification.

PubMed

Zeng, Mufan; de Vries, Wim; Bonten, Luc T C; Zhu, Qichao; Hao, Tianxiang; Liu, Xuejun; Xu, Minggang; Shi, Xiaojun; Zhang, Fusuo; Shen, Jianbo

2017-04-04

Agricultural soil acidification in China is known to be caused by the over-application of nitrogen (N) fertilizers, but the long-term impacts of different fertilization practices on intensive cropland soil acidification are largely unknown. Here, we further developed the soil acidification model VSD+ for intensive agricultural systems and validated it against observed data from three long-term fertilization experiments in China. The model simulated well the changes in soil pH and base saturation over the last 20 years. The validated model was adopted to quantify the contribution of N and base cation (BC) fluxes to soil acidification. The net NO 3 - leaching and NO 4 + input accounted for 80% of the proton production under N application, whereas one-third of acid was produced by BC uptake when N was not applied. The simulated long-term (1990-2050) effects of different fertilizations on soil acidification showed that balanced N application combined with manure application avoids reduction of both soil pH and base saturation, while application of calcium nitrate and liming increases these two soil properties. Reducing NH 4 + input and NO 3 - leaching by optimizing N management and increasing BC inputs by manure application thus already seem to be effective approaches to mitigating soil acidification in intensive cropland systems.

Impacts of 120 years of fertilizer addition on a temperate grassland ecosystem

PubMed Central

Kidd, Jonathan; Manning, Peter; Simkin, Janet; Peacock, Simon; Stockdale, Elizabeth

2017-01-01

The widespread application of fertilizers has greatly influenced many processes and properties of agroecosystems, and agricultural fertilization is expected to increase even further in the future. To date, most research on fertilizer impacts has used short-term studies, which may be unrepresentative of long-term responses, thus hindering our capacity to predict long-term impacts. Here, we examined the effects of long-term fertilizer addition on key ecosystem properties in a long-term grassland experiment (Palace Leas Hay Meadow) in which farmyard manure (FYM) and inorganic fertilizer treatments have been applied consistently for 120 years in order to characterize the experimental site more fully and compare ecosystem responses with those observed at other long-term and short-term experiments. FYM inputs increased soil organic carbon (SOC) stocks, hay yield, nutrient availability and acted as a buffer against soil acidification (>pH 5). In contrast, N-containing inorganic fertilizers strongly acidified the soil (

Transport, retention, and long-term release behavior of ZnO nanoparticle aggregates in saturated quartz sand: Role of solution pH and biofilm coating

USDA-ARS?s Scientific Manuscript database

The transport, retention, and long-term fate of zinc oxide nanoparticles (ZnO-NPs) were investigated in saturated, bare and biofilm (Pseudomonas putida) coated sand packed columns. Almost complete retention of ZnO-NPs occurred in bare and biofilm coated sand when the influent solution pH was 9 and t...

Low-temperature solution processing of palladium/palladium oxide films and their pH sensing performance.

PubMed

Qin, Yiheng; Alam, Arif U; Pan, Si; Howlader, Matiar M R; Ghosh, Raja; Selvaganapathy, P Ravi; Wu, Yiliang; Deen, M Jamal

2016-01-01

Highly sensitive, easy-to-fabricate, and low-cost pH sensors with small dimensions are required to monitor human bodily fluids, drinking water quality and chemical/biological processes. In this study, a low-temperature, solution-based process is developed to prepare palladium/palladium oxide (Pd/PdO) thin films for pH sensing. A precursor solution for Pd is spin coated onto pre-cleaned glass substrates and annealed at low temperature to generate Pd and PdO. The percentages of PdO at the surface and in the bulk of the electrodes are correlated to their sensing performance, which was studied by using the X-ray photoelectron spectroscope. Large amounts of PdO introduced by prolonged annealing improve the electrode's sensitivity and long-term stability. Atomic force microscopy study showed that the low-temperature annealing results in a smooth electrode surface, which contributes to a fast response. Nano-voids at the electrode surfaces were observed by scanning electron microscope, indicating a reason for the long-term degradation of the pH sensitivity. Using the optimized annealing parameters of 200°C for 48 h, a linear pH response with sensitivity of 64.71±0.56 mV/pH is obtained for pH between 2 and 12. These electrodes show a response time shorter than 18 s, hysteresis less than 8 mV and stability over 60 days. High reproducibility in the sensing performance is achieved. This low-temperature solution-processed sensing electrode shows the potential for the development of pH sensing systems on flexible substrates over a large area at low cost without using vacuum equipment. Copyright © 2015 Elsevier B.V. All rights reserved.

Field Performance of ISFET based Deep Ocean pH Sensors

NASA Astrophysics Data System (ADS)

Branham, C. W.; Murphy, D. J.

2017-12-01

Historically, ocean pH time series data was acquired from infrequent shipboard grab samples and measured using labor intensive spectrophotometry methods. However, with the introduction of robust and stable ISFET pH sensors for use in ocean applications a paradigm shift in the methods used to acquire long-term pH time series data has occurred. Sea-Bird Scientific played a critical role in the adoption this new technology by commercializing the SeaFET pH sensor and float pH Sensor developed by the MBARI chemical sensor group. Sea-Bird Scientific continues to advance this technology through a concerted effort to improve pH sensor accuracy and reliability by characterizing their performance in the laboratory and field. This presentation will focus on calibration of the ISFET pH sensor, evaluate its analytical performance, and validate performance using recent field data.

The impacts of pharmaceutical drugs under ocean acidification: New data on single and combined long-term effects of carbamazepine on Scrobicularia plana.

PubMed

Freitas, Rosa; Almeida, Ângela; Calisto, Vânia; Velez, Cátia; Moreira, Anthony; Schneider, Rudolf J; Esteves, Valdemar I; Wrona, Frederick J; Figueira, Etelvina; Soares, Amadeu M V M

2016-01-15

Ocean acidification and increasing discharges of pharmaceutical contaminants into aquatic systems are among key and/or emerging drivers of environmental change affecting marine ecosystems. A growing body of evidence demonstrates that ocean acidification can have direct and indirect impacts on marine organisms although combined effects with other stressors, namely with pharmaceuticals, have received very little attention to date. The present study aimed to evaluate the impacts of the pharmaceutical drug Carbamazepine and pH 7.1, acting alone and in combination, on the clam Scrobicularia plana. For this, a long-term exposure (28 days)was conducted and a set of oxidative stress markers was investigated. The results obtained showed that S. plana was able to develop mechanisms to prevent oxidative damage when under low pH for a long period, presenting higher survival when exposed to this stressor compared to CBZ or the combination of CBZ with pH 7.1. Furthermore, the toxicity of CBZ on S. plana was synergistically increased under ocean acidification conditions (CBZ + pH 7.1): specimens survival was reduced and oxidative stress was enhanced when compared to single exposures. These findings add to the growing body of evidence that ocean acidification will act to increase the toxicity of CBZ to marine organisms,which has clear implications for coastal benthic ecosystems suffering chronic pollution from pharmaceutical drugs.

Sensors for Environmental Control

NASA Technical Reports Server (NTRS)

1996-01-01

Under a Kennedy Space Center Small Business Innovation Research contract, GEO-CENTERS, Inc. developed a sensing element or 'optrode,' which NASA needed for space life support research to measure a hydroponic culture's pH factor. The company then commercialized the technology in the PC Based pH Monitoring System. The system employs the optrode to enable long term continuous monitoring of the pH level of fluids in standing and flowing conditions, an optoelectronic board with light sensors and detectors that fits into a desktop computer, and a fiber optic cable that connects the two. The system is effective in monitoring the pH output of industries to maintain ranges acceptable to the Environmental Protection Agency.

Interaction of soil pH and phosphorus efficacy: Long-term effects of P fertilizer and lime applications on wheat, barley, and sugar beet.

PubMed

von Tucher, Sabine; Hörndl, Dorothea; Schmidhalter, Urs

2018-01-01

Phosphorus (P), a plant macronutrient, must be adequately supplied for crop growth. In Germany, many soils are high in plant-available P; specifically in arable farming, P fertilizer application has been reduced or even omitted in the last decade. Therefore, it is important to understand how long these soils can support sustainable crop production, and what concentrations of soil P are required for it. We analyzed a 36-year long-term field experiment regarding the effects of different P application and liming rates on plant growth and soil P concentrations with a crop rotation of sugar beet, wheat, and barley. Sugar beet reacted to low soil P and low soil pH levels more sensitively than wheat, which was not significantly affected by the long-term omitted P application. All three crop species showed adequate growth at soil P levels lower than the currently recommended levels, if low soil pH was optimized by liming. The increase in efficacy of soil and fertilizer P by reduced P application rates therefore requires the adaptation of the soil pH to a soil type-specific optimal level.

Effects of pH during liquid storage of goat semen on sperm viability and fertilizing potential.

PubMed

Liu, Chang-He; Dong, Hai-Bo; Ma, Dong-Li; Li, You-Wei; Han, Dong; Luo, Ming-Jiu; Chang, Zhong-Le; Tan, Jing-He

2016-01-01

A specific problem in goat semen preservation is the detrimental effect of seminal plasma on sperm viability in extenders containing yolk or milk. Thus, the use of chemically defined extenders will have obvious advantages. Although previous studies indicate that the initial pH of an extender is crucial to sustain high sperm motility, changes in extender pH during long-term semen storage have not been observed. Monitoring extender pH at different times of semen storage and modeling its variation according to nonlinear models is thus important for protocol optimization for long-term liquid semen preservation. The present results showed that during long-term liquid storage of goat semen, both sperm motility and semen pH decreased gradually, and a strong correlation was observed between the two. Whereas increasing the initial extender pH from 6.04 to 6.25 or storage with stabilized pH improved, storage with artificially lowered pH impaired sperm motility. Extender renewal improved sperm motility by maintaining a stable pH. Sperm coating with chicken (Gallus gallus) egg yolk improved motility by increasing tolerance to pH decline. A new extender (n-mZAP) with a higher buffering capacity was formulated, and n-mZAP maintained higher sperm motility, membrane integrity and acrosome intactness than the currently used mZAP extender did. Goat semen liquid-stored for 12 d in n-mZAP produced pregnancy and kidding rates similar to those obtained with freshly collected semen following artificial insemination. In conclusion, maintenance of a stable pH during liquid semen storage dramatically improved sperm viability and fertilizing potential. Copyright © 2015 Elsevier B.V. All rights reserved.

Long-term mesocosms study of the effects of ocean acidification on growth and physiology of the sea urchin Echinometra mathaei.

PubMed

Moulin, Laure; Grosjean, Philippe; Leblud, Julien; Batigny, Antoine; Collard, Marie; Dubois, Philippe

2015-02-01

Recent research on the impact of ocean acidification (OA) has highlighted that it is important to conduct long-term experiments including ecosystem interactions in order to better predict the possible effects of elevated pCO2. The goal of the present study was to assess the long-term impact of OA on a suite of physiological parameters of the sea urchin Echinometra mathaei in more realistic food conditions. A long-term experiment was conducted in mesocosms provided with an artificial reef in which the urchins principally fed on algae attached to the reef calcareous substrate. Contrasted pH conditions (pH 7.7 vs control) were established gradually over six months and then maintained for seven more months. Acid-base parameters of the coelomic fluid, growth and respiration rate were monitored throughout the experiment. Results indicate that E. mathaei should be able to regulate its extracellular pH at long-term, through bicarbonate compensation. We suggest that, within sea urchins species, the ability to accumulate bicarbonates is related to their phylogeny but also on the quantity and quality of available food. Growth, respiration rate and mechanical properties of the test were not affected. This ability to resist OA levels expected for 2100 at long-term could determine the future of coral reefs, particularly reefs where E. mathaei is the major bioeroder. Copyright © 2014 Elsevier Ltd. All rights reserved.

Long term soil pH change in rainfed cropping systems: is acidification systemic?

USDA-ARS?s Scientific Manuscript database

Many soils throughout the northern Great Plains developed from deep, moderately-weathered glacial and loess deposits under prairie vegetation. Soils of this type are typically neutral to slightly acidic in near-surface depths, and slightly to strongly alkaline in subsoil depths, with high buffer cap...

Long-term nitrogen fertilization decreased the abundance of inorganic phosphate solubilizing bacteria in an alkaline soil

NASA Astrophysics Data System (ADS)

Zheng, Bang-Xiao; Hao, Xiu-Li; Ding, Kai; Zhou, Guo-Wei; Chen, Qing-Lin; Zhang, Jia-Bao; Zhu, Yong-Guan

2017-02-01

Inorganic phosphate solubilizing bacteria (iPSB) are essential to facilitate phosphorus (P) mobilization in alkaline soil, however, the phylogenetic structure of iPSB communities remains poorly characterized. Thus, we use a reference iPSB database to analyze the distribution of iPSB communities based on 16S rRNA gene illumina sequencing. Additionally, a noval pqqC primer was developed to quantify iPSB abundance. In our study, an alkaline soil with 27-year fertilization treatment was selected. The percentage of iPSB was 1.10~2.87% per sample, and the dominant iPSB genera were closely related to Arthrobacter, Bacillus, Brevibacterium and Streptomyces. Long-term P fertilization had no significant effect on the abundance of iPSB communities. Rather than P and potassium (K) additions, long-term nitrogen (N) fertilization decreased the iPSB abundance, which was validated by reduced relative abundance of pqqC gene (pqqC/16S). The decreased iPSB abundance was strongly related to pH decline and total N increase, revealing that the long-term N additions may cause pH decline and subsequent P releases relatively decreasing the demands of the iPSB community. The methodology and understanding obtained here provides insights into the ecology of inorganic P solubilizers and how to manipulate for better P use efficiency.

Government stewardship of the for-profit private health sector in Afghanistan

PubMed Central

Sayedi, Omarzaman; Irani, Laili; Archer, Lauren C.; Sears, Kathleen; Sharma, Suneeta

2017-01-01

Abstract Background: Since 2003, Afghanistan's largely unregulated for-profit private health sector has grown at a rapid pace. In 2008, the Ministry of Public Health (MoPH) launched a long-term stewardship initiative to oversee and regulate private providers and align the sector with national health goals. Aim: We examine the progress the MoPH has made towards more effective stewardship, consider the challenges and assess the early impacts on for-profit performance. Methods: We reviewed publicly available documents, publications and the grey literature to analyse the development, adoption and implementation of strategies, policies and regulations. We carried out a series of key informant/participant interviews, organizational capacity assessments and analyses of hospital standards checklists. Using a literature review of health systems strengthening, we proposed an Afghan-specific definition of six key stewardship functions to assess progress towards MoPH stewardship objectives. Results: The MoPH and its partners have achieved positive results in strengthening its private sector stewardship functions especially in generating actionable intelligence and establishing strategic policy directions, administrative structures and a legal and regulatory framework. Progress has also been made on improving accountability and transparency, building partnerships and applying minimum required standards to private hospitals. Procedural and operational issues still need resolution and the MoPH is establishing mechanisms for resolving them. Conclusions: The MoPH stewardship initiative is notable for its achievements to date under challenging circumstances. Its success is due to the focus on developing a solid policy framework and building institutions and systems aimed at ensuring higher quality private services, and a rational long-term and sustainable role for the private sector. Although the MoPH stewardship initiative is still at an early stage, the evidence suggests that enhanced stewardship functions in the MoPH are leading to a more efficient and effective for-profit private sector. These successful early efforts offer high-leverage potential to rapidly scale up going forward. PMID:27683341

Government stewardship of the for-profit private health sector in Afghanistan.

PubMed

Cross, Harry E; Sayedi, Omarzaman; Irani, Laili; Archer, Lauren C; Sears, Kathleen; Sharma, Suneeta

2017-04-01

Since 2003, Afghanistan's largely unregulated for-profit private health sector has grown at a rapid pace. In 2008, the Ministry of Public Health (MoPH) launched a long-term stewardship initiative to oversee and regulate private providers and align the sector with national health goals. We examine the progress the MoPH has made towards more effective stewardship, consider the challenges and assess the early impacts on for-profit performance. We reviewed publicly available documents, publications and the grey literature to analyse the development, adoption and implementation of strategies, policies and regulations. We carried out a series of key informant/participant interviews, organizational capacity assessments and analyses of hospital standards checklists. Using a literature review of health systems strengthening, we proposed an Afghan-specific definition of six key stewardship functions to assess progress towards MoPH stewardship objectives. The MoPH and its partners have achieved positive results in strengthening its private sector stewardship functions especially in generating actionable intelligence and establishing strategic policy directions, administrative structures and a legal and regulatory framework. Progress has also been made on improving accountability and transparency, building partnerships and applying minimum required standards to private hospitals. Procedural and operational issues still need resolution and the MoPH is establishing mechanisms for resolving them. The MoPH stewardship initiative is notable for its achievements to date under challenging circumstances. Its success is due to the focus on developing a solid policy framework and building institutions and systems aimed at ensuring higher quality private services, and a rational long-term and sustainable role for the private sector. Although the MoPH stewardship initiative is still at an early stage, the evidence suggests that enhanced stewardship functions in the MoPH are leading to a more efficient and effective for-profit private sector. These successful early efforts offer high-leverage potential to rapidly scale up going forward. © VC The Author 2016. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine.

Long-term effect of pH on short-chain fatty acids accumulation and microbial community in sludge fermentation systems.

PubMed

Yuan, Yue; Wang, Shuying; Liu, Ye; Li, Baikun; Wang, Bo; Peng, Yongzhen

2015-12-01

Long-term effect of pH (4, 10, and uncontrolled) on short-chain fatty acid (SCFA) accumulation, microbial community and sludge reduction were investigated in waste activated sludge (WAS) fermentors for over 90days. The average SCFAs accumulation was 1721.4 (at pH 10), 114.2 (at pH 4), and 58.1 (at uncontrolled pH) mg chemical oxygen demand (COD)/L. About 31.65mgCOD/L was produced at pH 10, accounting for 20% of the influent COD. Illumina MiSeq sequencing revealed that Alcaligenes (hydrolic bacteria) and Erysipelothrix (acidogenic bacteria) were enriched at pH 10, while less acidogenic bacteria existed at pH 4 than pH 10, and no acidogenic bacteria were detected at the uncontrolled pH. The ratios of archaea to bacteria were 1:41, 1:16, and 1:9 at the pH of 10, 4, and uncontrolled. This study elucidated the effects of pH on WAS fermentation, and established the correlation of microbial structure with SCFAs accumulations and sludge reduction. Copyright © 2015 Elsevier Ltd. All rights reserved.

Long-term effect of tobacco on unstimulated salivary pH.

PubMed

Grover, Neeraj; Sharma, Jyoti; Sengupta, Shamindra; Singh, Sanjeet; Singh, Nishant; Kaur, Harjeet

2016-01-01

The aim of this study was to analyze and compare the effects of tobacco on salivary pH between tobacco chewers, smokers and controls. A total of 60 subjects (males and females) aged 25-40 years, were divided equally into three groups: Tobacco smokers (Group A), chewers (Group B) and controls (Group C). Saliva of each subject was collected under resting condition. Salivary pH was determined using the specific salivary pH meter. The mean (±standard deviation) pH for Group A was 6.75 (±0.11), Group B was 6.5 (±0.29) and Group C was 7.00 (±0.28) after comparison. The significant results showed lower salivary pH in Groups A and B as compared to controls. Salivary pH was lowest in Group B compared to Group A and Group C. This study indicates that a lower (acidic) salivary pH was observed in tobacco users as compared with control. These alterations in pH due to the long-term effect of tobacco use can render oral mucosa vulnerable to various oral and dental diseases.

The long-term use of soap does not affect the pH-maintenance mechanism of human skin.

PubMed

Takagi, Y; Kaneda, K; Miyaki, M; Matsuo, K; Kawada, H; Hosokawa, H

2015-05-01

The pH at the surface of healthy human skin is around 5. Cleansing the skin with soap increases the pH of the skin, which then returns to a more acidic pH within a few hours. However, the effects of skin cleansing with soap over a long time on the pH regulatory system is still unclear. We compared the pH of the skin between users of a soap-based cleanser and of a mild-acidic cleanser prior to and following the cleansing. This study had two groups of subjects, one group who had used a soap-based cleanser for more than 5 years and the other group who had used a mild-acidic cleanser for more than 5 years. The pH on the inner forearm of each subject was measured prior to and for 6 h after cleansing with a soap bar. There were no differences between the pH of the skin these two groups prior to cleansing, immediately after cleansing or in the pH recovery rate for 6 h. These results suggest that long-term continuous use of a soap-based cleanser does not affect the pH-maintaining mechanism of human skin. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A new model integrating short- and long-term aging of copper added to soils

PubMed Central

Zeng, Saiqi; Li, Jumei; Wei, Dongpu

2017-01-01

Aging refers to the processes by which the bioavailability/toxicity, isotopic exchangeability, and extractability of metals added to soils decline overtime. We studied the characteristics of the aging process in copper (Cu) added to soils and the factors that affect this process. Then we developed a semi-mechanistic model to predict the lability of Cu during the aging process with descriptions of the diffusion process using complementary error function. In the previous studies, two semi-mechanistic models to separately predict short-term and long-term aging of Cu added to soils were developed with individual descriptions of the diffusion process. In the short-term model, the diffusion process was linearly related to the square root of incubation time (t1/2), and in the long-term model, the diffusion process was linearly related to the natural logarithm of incubation time (lnt). Both models could predict short-term or long-term aging processes separately, but could not predict the short- and long-term aging processes by one model. By analyzing and combining the two models, we found that the short- and long-term behaviors of the diffusion process could be described adequately using the complementary error function. The effect of temperature on the diffusion process was obtained in this model as well. The model can predict the aging process continuously based on four factors—soil pH, incubation time, soil organic matter content and temperature. PMID:28820888

Pulmonary Hypertension in Patients With Severe Aortic Stenosis: Prognostic Impact After Transcatheter Aortic Valve Replacement: Pulmonary Hypertension in Patients Undergoing TAVR.

PubMed

Alushi, Brunilda; Beckhoff, Frederik; Leistner, David; Franz, Marcus; Reinthaler, Markus; Stähli, Barbara E; Morguet, Andreas; Figulla, Hans R; Doenst, Torsten; Maisano, Francesco; Falk, Volkmar; Landmesser, Ulf; Lauten, Alexander

2018-04-13

The authors investigated the development of pulmonary hypertension (PH), predictors of PH regression, and its prognostic impact on short, mid-, and long-term outcomes in patients undergoing transcatheter aortic valve replacement (TAVR) for severe aortic stenosis (AS). PH represents a common finding in patients with AS. Although TAVR is frequently associated with regression of PH, the predictors of reversible PH and its prognostic significance remain uncertain. In this study, 617 consecutive patients undergoing TAVR between 2009 and 2015 were stratified per baseline tertiles of pulmonary artery systolic pressure (PASP) as follows: normal (PASP <34 mm Hg), mild-to-moderate (34 mm Hg ≤ PASP <46 mm Hg), and severe PASP elevation (PASP ≥46 mm Hg). After TAVR, 520 patients with PH at discharge were stratified according to the presence or absence of PASP reduction. Primary outcome was all-cause mortality at 30 days, 1 year, and long-term follow-up at a maximum of 5.9 years. In patients with both mild-to-moderate and severe PH at baseline, PASP decreased significantly at discharge (ΔPASP 3.0 ± 9.3 mm Hg and 12.0 ± 10.0 mm Hg, respectively) and 1 year (ΔPASP 5.0 ± 9.7 mm Hg and 18.0 ± 14.0 mm Hg, respectively). At a median follow-up of 370 days (interquartile range [IQR]: 84 to 500 days), the risk of all-cause mortality was similar among baseline PASP groups at all time intervals evaluated. After TAVR, a significant regression of PH was observed in 46% of patients. Contrarily, patients with residual PH had a higher risk of all-cause mortality at 30 days (hazard ratio [HR]: 3.49, 95% confidence interval [CI]: 1.74 to 6.99; p < 0.001), 1 year (HR: 3.12, 95% CI: 2.06 to 4.72; p < 0.001), and long-term (HR: 2.47, 95% CI: 1.74 to 3.49; p < 0.001). Left ventricular ejection fraction (LVEF) >40% (odds ratio [OR]: 3.56, 95% CI: 2.24 to 5.65; p < 0.001), baseline PASP ≥46 mm Hg (OR: 3.26, 95% CI: 2.07 to 5.12; p < 0.001), absence of concomitant tricuspid regurgitation (TR) ≥ moderate (OR: 0.53, 95% CI: 0.34 to 0.84; p < 0.001), and logistic EuroSCORE <25% (OR: 1.59, 95% CI: 1.04 to 2.45; p = 0.03) were independent predictors of PASP reduction. In most patients with PH and AS, TAVR is associated with a significant early and late reduction of PASP. Patients with reversible PH after TAVR are at lower risk of all-cause mortality at early, mid-, and long-term follow-up. Therefore, the presence of PH should not preclude treatment with TAVR. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Influence of long-term fertilization on soil physicochemical properties in a brown soil

NASA Astrophysics Data System (ADS)

Li, Dongdong; Luo, Peiyu; Han, Xiaori; Yang, Jinfeng

2018-01-01

This study aims to explore the influence on soil physicochemical properties under a 38-y long-term fertilization in a brown soil. Soil samples (0-20 cm)were taken from the six treatments of the long-term fertilization trial in October 2016:no fertilizer (CK), N1(mineral nitrogen fertilizer), N1P (mineral nitrogen and phosphate fertilizer), N1PK (mineral nitrogen, phosphate and potassic fertilizer), pig manure (M2), M2N1P (pig manure, mineral nitrogen and phosphate fertilizer).The results showed thatthe long-term application of chemical fertilizers reduced soil pH value, while the application of organic fertilizers increased pH value. Fertilization significantly increased the content of AHN, TN and SOM. Compared with the CK treatment and chemical fertilizer treatments, organic fertilizer treatments significantly increased the content of AP and TP. The content of AK and TK were no significant difference in different treatment.

Use of Cox's Cure Model to Establish Clinical Determinants of Long-Term Disease-Free Survival in Neoadjuvant-Chemotherapy-Treated Breast Cancer Patients without Pathologic Complete Response.

PubMed

Asano, Junichi; Hirakawa, Akihiro; Hamada, Chikuma; Yonemori, Kan; Hirata, Taizo; Shimizu, Chikako; Tamura, Kenji; Fujiwara, Yasuhiro

2013-01-01

In prognostic studies for breast cancer patients treated with neoadjuvant chemotherapy (NAC), the ordinary Cox proportional-hazards (PH) model has been often used to identify prognostic factors for disease-free survival (DFS). This model assumes that all patients eventually experience relapse or death. However, a subset of NAC-treated breast cancer patients never experience these events during long-term follow-up (>10 years) and may be considered clinically "cured." Clinical factors associated with cure have not been studied adequately. Because the ordinary Cox PH model cannot be used to identify such clinical factors, we used the Cox PH cure model, a recently developed statistical method. This model includes both a logistic regression component for the cure rate and a Cox regression component for the hazard for uncured patients. The purpose of this study was to identify the clinical factors associated with cure and the variables associated with the time to recurrence or death in NAC-treated breast cancer patients without a pathologic complete response, by using the Cox PH cure model. We found that hormone receptor status, clinical response, human epidermal growth factor receptor 2 status, histological grade, and the number of lymph node metastases were associated with cure.

Development of a novel pH sensor based upon Janus Green B immobilized on triacetyl cellulose membrane: Experimental design and optimization.

PubMed

Chamkouri, Narges; Niazi, Ali; Zare-Shahabadi, Vali

2016-03-05

A novel pH optical sensor was prepared by immobilizing an azo dye called Janus Green B on the triacetylcellulose membrane. Condition of the dye solution used in the immobilization step, including concentration of the dye, pH, and duration were considered and optimized using the Box-Behnken design. The proposed sensor showed good behavior and precision (RSD<5%) in the pH range of 2.0-10.0. Advantages of this optical sensor include on-line applicability, no leakage, long-term stability (more than 6 months), fast response time (less than 1 min), high selectivity and sensitivity as well as good reversibility and reproducibility. Copyright © 2015. Published by Elsevier B.V.

The impact of concomitant pulmonary hypertension on early and late outcomes following surgery for mitral stenosis.

PubMed

Yang, Bo; DeBenedictus, Christina; Watt, Tessa; Farley, Sean; Salita, Alona; Hornsby, Whitney; Wu, Xiaoting; Herbert, Morley; Likosky, Donald; Bolling, Steven F

2016-08-01

To provide initial evidence on the management of mitral stenosis and pulmonary hypertension (PH) based on short-term and long-term outcomes following mitral valve surgery. Consecutive patients with mitral stenosis (n = 317) who had undergone mitral valve surgery between 1992 and 2014 with recorded pulmonary artery pressure (PAP) data were reviewed. PH severity, based on systolic PAP, was categorized as mild (35 to 44 mm Hg), moderate (45 to 59 mm Hg), or severe (>60 mm Hg). Primary outcomes were 30-day mortality and long-term survival. There were no significant between-group differences in age or preoperative comorbidities. Mitral valve surgery included mitral valve replacement (78%) and repair (22%). The severe PH group had more mitral valve replacement (81%; P = .04), severe tricuspid valve regurgitation (31%; P = .003), right heart failure (17%; P = .02), and concomitant tricuspid valve procedures (46%; P < .001). For severe PH, 30-day mortality was 9%, with no significant group differences. Ten- and 12-year survival were significantly worse in the moderate-severe PH group (58% and 51%, respectively) compared with the normal PAP-mild PH group (83% and 79%, respectively) with a hazard ratio of 2.98 (95% confidence interval, 1.55-5.75; P = .001). Ten-year survival after mitral valve surgery for mitral stenosis was inversely associated with preoperative PAP. Mitral valve surgery can be performed with acceptable 30-day mortality for patients with mitral stenosis and moderate to severe PH, but long-term survival is impaired by moderate to severe PH. Patients with mitral stenosis and mild PH (systolic PAP 35-44 mm Hg) should be considered for mitral valve surgery. Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Trends and variations of pH and hardness in a typical semi-arid river in a monsoon climate region during 1985-2009.

PubMed

Hao, Shaonan; Li, Xuyong; Jiang, Yan; Zhao, Hongtao; Yang, Lei

2016-09-01

The rapid growth of urbanization and industrialization, along with dramatic climate change, has strongly influenced hydrochemical characteristics in recent decades in China and thus could cause the variation of pH and general total hardness of a river. To explore such variations and their potential influencing factors in a river of the monsoon climate region, we analyzed a long-term monitoring dataset of pH, SO4 (2-), NOx, general total hardness (GH), Mg(2+), Ca(2+), and Cl(-) in surface water and groundwater in the Luan River basin from 1985 to 2009. The nonparametric Seasonal Kendall trend test was used to test the long-term trends of pH and GH. Relationship between the affecting factors, pH and GH were discussed. Results showed that pH showed a decreasing trend and that GH had an increasing trend in the long-term. Seasonal variation of pH and GH was mainly due to the typical monsoon climate. Results of correlation analysis showed that the unit area usage amounts of chemical fertilizer, NO3 (-), and SO4 (2-) were negatively correlated with pH in groundwater. In addition, mining activity affected GH spatial variation. Acid deposition, drought, and increasing the use of chemical fertilizers would contribute to the acidification trend, and mining activities would affect the spatial variation of GH. Variations of precipitation and runoff in semi-arid monsoon climate areas had significant influences on the pH and GH. Our findings implied that human activities played a critical role in river acidification in the semi-arid monsoon climate region of northern China.

Cough response and uptake of mercury by Brook trout, Salvelinus fontinalis, exposed to mercuric compounds at different hydrogen-ion concentrations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drummond, R.A.; Olson, G.F.; Battermna, A.R.

1974-01-01

The lowest concentration of methylmercuric chloride (MMC) and mercuric chloride added to Lake Superior water that caused a significant increase in cough frequency in Brook trout was 3 micrograms Hg/liter. Cough frequency is a good short-term indicator of the long-term effects of MMC. The response can be used to predict the safe concentration of mercuric chloride since the long-term effects of the compound are not known. Increases in cough frequency were proportional to the concentration (from 3 to 12 micrograms Hg/liter) of both compounds at pH 7.5. The fish were more responsive to MMC when the pH of the testmore » water was lowered to 6.0; response to mercuric chloride was not changed by lowered pH. Fish exposed to MMC at pH 6.0 contained more total mercury in their gills and red blood cells than fish tested at pH 9.0. The uptake of mercury by brook trout exposed to mercuric chloride did not differ significantly at pH 6.0 and 9.0.« less

Can Echocardiography, Especially Tricuspid Annular Plane Systolic Excursion Measurement, Predict Pulmonary Hypertension and Improve Prognosis in Patients on Long-Term Dialysis?

PubMed Central

Grabysa, Radosław; Wańkowicz, Zofia

2015-01-01

In recent years, increasing attention has been paid to pulmonary hypertension (PH) as a strong and independent risk factor for adverse outcome in the population of patients on long-term dialysis. Published results of observational studies indicate that the problem of PH refers mostly to patients on long-term hemodialysis and is less common in peritoneal dialysis patients. The main cause of this complication is proximal location of the arteriovenous fistula, causing chronically increased cardiac output. This paper presents the usefulness of transthoracic echocardiography (TTE) for measurement of the Tricuspid Annular Plane Systolic Excursion (TAPSE) in the early diagnosis of PH in dialysis patients. Echocardiographic diagnosis of pulmonary hypertension with TTE, especially in the case of HD patients, ensures the selection of the proper location for the first arteriovenous fistula and facilitates the decision to switch to peritoneal dialysis or to accelerate the process of qualification for kidney transplantation. PMID:26697754

Can Echocardiography, Especially Tricuspid Annular Plane Systolic Excursion Measurement, Predict Pulmonary Hypertension and Improve Prognosis in Patients on Long-Term Dialysis?

PubMed

Grabysa, Radosław; Wańkowicz, Zofia

2015-12-23

In recent years, increasing attention has been paid to pulmonary hypertension (PH) as a strong and independent risk factor for adverse outcome in the population of patients on long-term dialysis. Published results of observational studies indicate that the problem of PH refers mostly to patients on long-term hemodialysis and is less common in peritoneal dialysis patients. The main cause of this complication is proximal location of the arteriovenous fistula, causing chronically increased cardiac output. This paper presents the usefulness of transthoracic echocardiography (TTE) for measurement of the Tricuspid Annular Plane Systolic Excursion (TAPSE) in the early diagnosis of PH in dialysis patients. Echocardiographic diagnosis of pulmonary hypertension with TTE, especially in the case of HD patients, ensures the selection of the proper location for the first arteriovenous fistula and facilitates the decision to switch to peritoneal dialysis or to accelerate the process of qualification for kidney transplantation.

Long-term tobacco plantation induces soil acidification and soil base cation loss.

PubMed

Zhang, Yuting; He, Xinhua; Liang, Hong; Zhao, Jian; Zhang, Yueqiang; Xu, Chen; Shi, Xiaojun

2016-03-01

Changes in soil exchangeable cations relative to soil acidification are less studied particularly under long-term cash crop plantation. This study investigated soil acidification in an Ali-Periudic Argosols after 10-year (2002-2012) long-term continuous tobacco plantation. Soils were respectively sampled at 1933 and 2143 sites in 2002 and 2012 (also 647 tobacco plants), from seven tobacco plantation counties in the Chongqing Municipal City, southwest China. After 10-year continuous tobacco plantation, a substantial acidification was evidenced by an average decrease of 0.20 soil pH unit with a substantial increase of soil sites toward the acidic status, especially those pH ranging from 4.5 to 5.5, whereas 1.93 kmol H(+) production ha(-1) year(-1) was mostly derived from nitrogen (N) fertilizer input and plant N uptake output. After 1 decade, an average decrease of 27.6 % total exchangeable base cations or of 0.20 pH unit occurred in all seven tobacco plantation counties. Meanwhile, for one unit pH decrease, 40.3 and 28.3 mmol base cations kg(-1) soil were consumed in 2002 and 2012, respectively. Furthermore, the aboveground tobacco biomass harvest removed 339.23 kg base cations ha(-1) year(-1) from soil, which was 7.57 times higher than the anions removal, leading to a 12.52 kmol H(+) production ha(-1) year(-1) as the main reason inducing soil acidification. Overall, our results showed that long-term tobacco plantation not only stimulated soil acidification but also decreased soil acid-buffering capacity, resulting in negative effects on sustainable soil uses. On the other hand, our results addressed the importance of a continuous monitoring of soil pH changes in tobacco plantation sites, which would enhance our understanding of soil fertility of health in this region.

Long-Term Health Outcomes in High-Altitude Pulmonary Hypertension

PubMed Central

Abbott, Cheryl; Meadows, Christina A.; Roach, Robert C.; Honigman, Benjamin; Bull, Todd M.

2017-01-01

Abstract Robinson, Jeffrey C., Cheryl Abbott, Christina A. Meadows, Robert C. Roach, Benjamin Honigman, and Todd M. Bull. Long-term health outcomes in high-altitude pulmonary hypertension. High Alt Med Biol. 18:61–66, 2017. Background: High-altitude pulmonary hypertension (HAPH) is one of several known comorbidities that effect populations living at high altitude, but there have been no studies looking at long-term health consequences of HAPH. We aimed to determine whether HAPH during adolescence predisposes to significant pulmonary hypertension (PH) later in life, as well as identify how altitude exposure and HAPH correlate with functional class and medical comorbidities. Methods: We utilized a previously published cohort of 28 adolescents from Leadville, Colorado, that underwent right heart catheterization at 10,150 ft (3094 m) in 1962, with many demonstrating PH as defined by resting mean pulmonary arterial pressure ≥25 mmHg. We located participants of the original study and had living subjects complete demographic and health surveys to assess for the presence of PH and other medical comorbidities, along with current functional status. Results: Seventy-five percent of the individuals who participated in the original study were located. Those with HAPH in the past were more prone to have exertional limitation corresponding to WHO functional class >1. Fifty-five years following the original study, we found no significant differences in prevalence of medical comorbidities, including PH, among those with and without HAPH in their youth. Conclusions: Surveyed individuals did not report significant PH, but those with HAPH in their youth were more likely to report functional limitation. With a significant worldwide population living at moderate and high altitudes, further study of long-term health consequences is warranted. PMID:28061144

BSA-coated nanoparticles for improved SERS-based intracellular pH sensing.

PubMed

Zheng, Xiao-Shan; Hu, Pei; Cui, Yan; Zong, Cheng; Feng, Jia-Min; Wang, Xin; Ren, Bin

2014-12-16

Local microenvironment pH sensing is one of the key parameters for the understanding of many biological processes. As a noninvasive and high sensitive technique, surface-enhanced Raman spectroscopy (SERS) has attracted considerable interest in the detection of the local pH of live cells. We herein develop a facile way to prepare Au-(4-MPy)-BSA (AMB) pH nanosensor. The 4-MPy (4-mercaptopyridine) was used as the pH sensing molecule. The modification of the nanoparticles with BSA not only provides a high sensitive response to pH changes ranging from pH 4.0 to 9.0 but also exhibits a high sensitivity and good biocompatibility, stability, and reliability in various solutions (including the solutions of high ionic strength or with complex composition such as the cell culture medium), both in the aggregation state or after long-term storage. The AMB pH nanosensor shows great advantages for reliable intracellular pH analysis and has been successfully used to monitor the pH distribution of live cells and can address the grand challenges in SERS-based pH sensing for practical biological applications.

Low pH Springs - A Natural Laboratory for Ocean Acidification

NASA Astrophysics Data System (ADS)

Derse, E.; Rebolledo-Vieyra, M.; Potts, D. C.; Paytan, A.

2009-12-01

Recent increases in atmospheric carbon dioxide of 40% above pre-industrial levels has resulted in rising aqueous CO2 concentrations that lower the pH of the oceans. Currently, the surface ocean has an average pH between 8.1 and 8.2: it is estimated that over the next 100 years this value will decrease by ~0.4 pH units. Previous studies have highlighted the negative impacts that changes in pH (and the resulting CaCO3 saturation state) have on marine organisms; however, to date, very little is known about the long-term impacts of ocean acidification on ecosystems as a whole. The Yucatán Peninsula of Quintana Roo, Mexico, represents an ecosystem where naturally low pH groundwater (7.25-8.07) has been discharging offshore at highly localized points (called ojos) since the last deglaciation. We present preliminary chemical and biological data on a selection of ojos from lagoon sites in Puerto Morelos, Mexico. We address the potential long-term implications of low pH waters on marine ecosystems.

Surface coal mine land reclamation using a dry flue gas desulfurization product: Short-term and long-term water responses.

PubMed

Chen, Liming; Stehouwer, Richard; Tong, Xiaogang; Kost, Dave; Bigham, Jerry M; Dick, Warren A

2015-09-01

Abandoned coal-mined lands are a worldwide concern due to their potential negative environmental impacts, including erosion and development of acid mine drainage. A field study investigated the use of a dry flue gas desulfurization product for reclamation of abandoned coal mined land in USA. Treatments included flue gas desulfurization product at a rate of 280 Mg ha(-1) (FGD), FGD at the same rate plus 112 Mg ha(-1) yard waste compost (FGD/C), and conventional reclamation that included 20 cm of re-soil material plus 157 Mg ha(-1) of agricultural limestone (SOIL). A grass-legume sward was planted after treatment applications. Chemical properties of surface runoff and tile water (collected from a depth of 1.2m below the ground surface) were measured over both short-term (1-4 yr) and long-term (14-20 yr) periods following reclamation. The pH of surface runoff water was increased from approximately 3, and then sustained at 7 or higher by all treatments for up to 20 yr, and the pH of tile flow water was also increased and sustained above 5 for 20 yr. Compared with SOIL, concentrations of Ca, S and B in surface runoff and tile flow water were generally increased by the treatments with FGD product in both short- and long-term measurements and concentrations of the trace elements were generally not statistically increased in surface runoff and tile flow water over the 20-yr period. However, concentrations of As, Ba, Cr and Hg were occasionally elevated. These results suggest the use of FGD product for remediating acidic surface coal mined sites can provide effective, long-term reclamation. Copyright © 2015. Published by Elsevier Ltd.

A long-term stability study of Prussian blue: A quality assessment of water content and cesium binding.

PubMed

Mohammad, Adil; Yang, Yongsheng; Khan, Mansoor A; Faustino, Patrick J

2015-01-25

Prussian blue (PB) is the active pharmaceutical ingredient (API) of Radiogardase, the first approved medical countermeasure for the treatment of radiocesium poisoning in the event of a major radiological incident such as a "dirty bomb" or nuclear attack. The purpose of this study is to assess the long-term stability of Prussian blue drug products (DPs) and APIs under laboratory storage condition by monitoring the loss in water content and the in vitro cesium binding. The water content was measured by thermal gravimetric analysis (TGA). The in-vitro cesium binding study was conducted using a surrogate model to mimic gastric residence and intestinal transport. Free cesium was analyzed using a validated flame atomic emission spectroscopy (AES) method. The binding equilibrium was reached at 24h. The Langmuir isotherm was plotted to calculate the maximum binding capacity (MBC). Comparison of the same PB samples with 2003 data samples, the water content of both APIs and DPs decreased on an average by approximately 12-24%. Consequently, the MBC of cesium was decreased from 358mg/g in 2003 to 265mg/g @ pH 7.5, a decrease of approximately 26%. The binding of cesium is also pH dependent with lowest binding at pH 1.0 and maximum binding at pH 7.5. At pH 7.5, the amount of cesium bound decreased by an average value of 7.9% for APIs and 8.9% for DPs (for 600ppm initial cesium concentration). These findings of water loss, pH dependence and decrease in cesium binding are consistent with our previously published data in 2003. Over last 10 years the stored DPs and APIs of PB have lost about 20% of water which has a negative impact on the PB cesium binding, however PB still meets the FDA specification of >150mg/g at equilibrium. The study is the first quantitative assessment of the long-term stability of PB and directs that proper long-term and short-term storage of PB is required to ensure that it is safe and efficacious at the time of an emergency situation. Published by Elsevier B.V.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Casella, Amanda J.; Hylden, Laura R.; Campbell, Emily L.

Knowledge of real-time solution properties and composition is a necessity for any spent nuclear fuel reprocessing method. Metal-ligand speciation in aqueous solutions derived from the dissolved commercial spent fuel is highly dependent upon the acid concentration/pH, which influences extraction efficiency and the resulting speciation in the organic phase. Spectroscopic process monitoring capabilities, incorporated in a counter current centrifugal contactor bank, provide a pathway for on-line real-time measurement of solution pH. The spectroscopic techniques are process-friendly and can be easily configured for on-line applications, while classic potentiometric pH measurements require frequent calibration/maintenance and have poor long-term stability in aggressive chemical andmore » radiation environments. Our research is focused on developing a general method for on-line determination of pH of aqueous solutions through chemometric analysis of Raman spectra. Interpretive quantitative models have been developed and validated under the range of chemical composition and pH using a lactic acid/lactate buffer system. The developed model was applied to spectra obtained on-line during solvent extractions performed in a centrifugal contactor bank. The model predicted the pH within 11% for pH > 2, thus demonstrating that this technique could provide the capability of monitoring pH on-line in applications such as nuclear fuel reprocessing.« less

2D ratiometric fluorescent pH sensor for tracking of cells proliferation and metabolism.

PubMed

Ma, Jun; Ding, Changqin; Zhou, Jie; Tian, Yang

2015-08-15

Extracellular pH plays a vital role no matter in physiological or pathological studies. In this work, a hydrogel, CD@Nile-FITC@Gel (Gel sensor), entrapping the ratiometric fluorescent probe CD@Nile-FITC was developed. The Gel sensor was successfully used for real-time extracellular pH monitoring. In the case of CD@Nile-FITC, pH-sensitive fluorescent dye fluorescein isothiocyanate (FITC) was chosen as the response signal for H(+) and Nile blue chloride (Nile) as the reference signal. The developed fluorescent probe exhibited high selectivity for pH over other metal ions and amino acids. Meanwhile, the carbon-dots-based inorganic-organic probe demonstrated excellent photostability against long-term light illumination. In order to study the extracellular pH change in processes of cell proliferation and metabolism, CD@Nile-FITC probe was entrapped in sodium alginate gel and consequently formed CD@Nile-FITC@Gel. The MTT assay showed low cytotoxicity of the Gel and the pH titration indicated that it could monitor the pH fluctuations linearly and rapidly within the pH range of 6.0-9.0, which is valuable for physiological pH determination. As expected, the real-time bioimaging of the probe was successfully achieved. Copyright © 2015 Elsevier B.V. All rights reserved.

Long-term evolution of highly alkaline steel slag drainage waters.

PubMed

Riley, Alex L; Mayes, William M

2015-07-01

The disposal of slag generated by the steel industry can have negative consequences upon the surrounding aquatic environment by the generation of high pH waters, leaching of potentially problematic trace metals, and rapid rates of calcite precipitation which smother benthic habitats. A 36-year dataset was collated from the long-term ambient monitoring of physicochemical parameters and elemental concentrations of samples from two steel slag leachate-affected watercourses in northern England. Waters were typified by elevated pH (>10), high alkalinity, and were rich in dissolved metals (e.g. calcium (Ca), aluminium (Al), and zinc (Zn)). Long-term trend analysis was performed upon pH, alkalinity, and Ca concentration which, in addition to Ca flux calculations, were used to highlight the longevity of pollution arising as a result of the dumping and subsequent leaching of steel slags. Declines in calcium and alkalinity have been modest over the monitoring period and not accompanied by significant declines in water pH. If the monotonic trends of decline in alkalinity and calcium continue in the largest of the receiving streams, it will be in the region of 50-80 years before calcite precipitation would be expected to be close to baseline levels, where ecological impacts would be negligible.

Limitations and possibilities of green synthesis and long-term stability of colloidal Ag nanoparticles

NASA Astrophysics Data System (ADS)

Velgosová, Oksana; Mražíková, Anna

2017-12-01

In this paper the influence of algae life cycle and the solutions pH on the green synthesis of colloidal Ag nanoparticles (AgNPs) as well as effect of different storage conditions on AgNPs long-term stability was investigated. Silver nanoparticles were biologically synthesized using extracts of Parachlorella kessleri algae cultivated 1, 2, 3 and 4 weeks. The formation of AgNPs was monitored using a UV-vis spectrophotometer and verified by TEM observation. The results confirmed formation of polyhedron and/or near polyhedron AgNPs, ranging between 5 and 60 nm in diameter. The age of algae influenced the synthesis rate and an amount of AgNPs in solution. The best results were obtained using tree weeks old algae. UV-vis analysis and TEM observation also revealed that the size and the stability of AgNPs depend on the pH of solution. AgNPs formed in solutions of higher pH (8 and 10) are polyhedron, fine, with narrow size interval and stabile. Nanoparticles formed in solutions of low pH (2, 4 and 6) started to lose their stability on 10th day of experiment, and the particle size interval was wide. The long-term stability of AgNPs can be influenced by light and temperature conditions. The most significant stability loss was observed at day light and room temperature (21°C). After 200-days significant amount of agglomerated particles settled on the bottom of the Erlenmeyer flask. AgNPs stored at dark and room temperature showed better long-term stability, weak particles agglomeration was observed. AgNPs stored at dark and at temperature 5°C showed the best long-term stability. Such AgNPs remained spherical, fine (5-20 nm), with narrow size interval and stable (no agglomeration) even after more than six months.

How Do You Motivate Long-Term Behavior Change to Prevent Cancer?

Cancer.gov

John P. Pierce PhD, a professor in the Department of Family and Preventive Medicine at the University of California, San Diego and Director of Population Science at Moores Cancer Center, presented "How Do You Motivate Long-Term Behavior Change to Prevent Cancer?" 

Acid production potentials of massive sulfide minerals and lead-zinc mine tailings: a medium-term study.

PubMed

Çelebi, Emin Ender; Öncel, Mehmet Salim; Kobya, Mehmet

2018-01-01

Weathering of sulfide minerals is a principal source of acid generation. To determine acid-forming potentials of sulfide-bearing materials, two basic approaches named static and kinetic tests are available. Static tests are short-term, and easily undertaken within a few days and in a laboratory. In contrast, kinetic tests are long-term procedures and mostly carried out on site. In this study, experiments were conducted over a medium-term period of 2 months, not as short as static tests and also not as long as kinetic tests. As a result, pH and electrical conductivity oscillations as a function of time, acid-forming potentials and elemental contents of synthetically prepared rainwater leachates of massive sulfides and sulfide-bearing lead-zinc tailings from abandoned and currently used deposition areas have been determined. Although the lowest final pH of 2.70 was obtained in massive pyrite leachate, massive chalcopyrite leachate showed the highest titrable acidity of 1.764 g H 2 SO 4 /L. On the other hand, a composite of currently deposited mine tailings showed no acidic characteristic with a final pH of 7.77. The composite abandoned mine tailing leachate had a final pH of 6.70, close to the final pH of massive galena and sphalerite leachates, and produced a slight titrable acidity of 0.130 g H 2 SO 4 /L.

A comparative study on oxidative stress response in the hepatopancreas and midgut of the white shrimp Litopenaeus vannamei under gradual changes to low or high pH environment.

PubMed

Han, Si-Yin; Wang, Meng-Qiang; Wang, Bao-Jie; Liu, Mei; Jiang, Ke-Yong; Wang, Lei

2018-05-01

White shrimp Litopenaeus vannamei were reared under conditions of gradual changes to a low pH (gradual-low pH, 6.65-8.20) or a high pH (gradual-high pH, 8.20-9.81) versus a normal pH environment (8.14-8.31) during a 28-day period. Survival of shrimp, and ROS production, antioxidant responses and oxidative damage in the hepatopancreas and midgut were investigated. Consequently, shrimp enhanced MnSOD, GPx, and Hsp70 transcripts as early defense mechanism in the hepatopancreas and midgut to scavenge excessive ROS during short-term (≤ 7 days) gradual-low and high pH stress. Meanwhile, the hepatopancreas was more sensitive to ROS than midgut because of earlier ROS production increase, antioxidant response and oxidative damage. Then, suppressed antioxidant response in the hepatopancreas and midgut of shrimp suggested a loss of antioxidant regulatory capacity caused by aggravated oxidative damage after long-term (≥ 14 days) gradual-high pH stress, leading to continuous death. However, enhanced GPx, GST, and Hsp70 transcripts in the hepatopancreas and midgut might be long-term(≥ 14 days) antioxidant adaptation mechanism of shrimp to gradual-low pH stress, which could prevent further ROS perturbation and weaken oxidative damage to achieve a new immune homeostasis, contributing to stable survival rate. Therefore, we have a few insights that it is necessary to protect hepatopancreas for controlling shrimp death under gradual-high pH stress. Copyright © 2018 Elsevier Ltd. All rights reserved.

Long-term stability study of Prussian blue-A quality assessment of water content and cyanide release.

PubMed

Mohammad, A; Yang, Y; Khan, M A; Faustino, P J

2015-02-01

Prussian blue, ferric hexacyanoferrate is approved for (oral) treatment of internal contamination with radioisotopes of cesium or thallium. Cyanide makes up 35-40% of Prussian blue's molecular composition; thus, cyanide may be released during transit through the digestive tract under physiological pH conditions. The purpose of this study is to assess the long-term stability of Prussian blue drug products and active pharmaceutical ingredients and its impact on cyanide release. The study involves the determination and comparison of the loss in water content and cyanide released from Prussian blue under pH conditions that bracket human physiological exposure. Test samples of active pharmaceutical ingredient and drug product were stored for 10 years at ambient temperatures that mimic warehouse storage conditions. Water loss from Prussian blue was measured using thermogravimetric analysis. An in vitro physiological pH model that brackets gastric exposure and gastrointestinal transit was utilized for cyanide release. Prussian blue was incubated in situ at pH: 1.0, 5.0, and 7.0 @ 37°C for 1-24 h. Cyanide was measured using a validated colorimetric method by UV-Vis spectroscopy. Although the water content (quality attribute) of Prussian blue active pharmaceutical ingredient and drug product decreased by about 10.5% and 13.8%, respectively, since 2003, the cyanide release remained comparable. At pH of 7.0 for 24 h cyanide released from active pharmaceutical ingredient-1 was 21.33 ± 1.76 μg/g in 2004, and 28.45 ± 3.15 μg/g in 2013; cyanide released from drug product-1 was 21.89 ± 0.56 μg/g in 2004, and 27.31 ± 5.78 μg/g in 2013. At gastric pH of 1.0 and upper gastrointestinal pH of 5.0, the data for active pharmaceutical ingredients and drug products were also comparable in 2013. The cyanide release is still pH-dependent and follows the same trend as observed in 2003 with minimum release at pH of 5.0 and maximal release at pH of 1.0. In summary, this is the long-term stability study of Prussian blue which correlates cyanide release to water loss. Cyanide released from Prussian blue was maximum at pH of 1.0 (47.47 μg/g) and minimum at pH of 5.0-7.0 (20.01 μg/g). Based on maximal dose, maximal residence time in stomach and intestine, the maximal cyanide released from Prussian blue is about 1.31 mg, which is far below the minimal lethal dose of cyanide of 50 mg, and therefore does not present a safety concern following long-term storage.

THE PHYTOAVAILABILITY OF CADMIUM TO LETTUCE IN LONG-TERM BIOSOLIDS-AMENDED SOILS

EPA Science Inventory

A field study was conducted to assess the phytoavailability of Cd in long-term biosolids-amended field plots managed at high and low pH. The experiment, established 13-15 yr prior to the present cropping, on a Christiana fine sandy loam soil (a clayey, kaolinitic, mesic Typic Pa...

A novel axial-stress bioreactor system combined with a substance exchanger for tissue engineering of 3D constructs.

PubMed

Li, Song-Tao; Liu, Yong; Zhou, Qiang; Lue, Ren-Fa; Song, Lei; Dong, Shi-Wu; Guo, Ping; Kopjar, Branko

2014-03-01

This study introduced a prototype of an axial-stress bioreactor system that supports long-term growth and development of engineered tissues. The main features of this bioreactor are an integrated substance exchanger and feedback control of pH and PO₂. A 21-day study was conducted to validate the system's ability to maintain a stable environment, while remaining sterile. Our results showed that the pH, PO₂, and nutrient (glucose) remained balanced at appropriate levels, while metabolic waste (lactic acid) was removed. No bacteria or fungi were detected in the system or tissue; thus, demonstrating that it was sterile. These data indicate the bioreactor's strong potential for long-term tissue culture. To explore this idea, the effect of dynamic culture, including cyclic compression and automatic substance exchange, on mouse bone-marrow mesenchymal stem cells (BMSCs) seeded in decalcified bone matrix was studied using the bioreactor prototype. Histological sections of the engineered tissues showed higher cell densities in scaffolds in dynamic culture compared to those in static culture, while cell cycle analysis showed that dynamic culture promoted BMSC proliferation (proliferation index, PI=34.02±1.77) more effectively than static culture (PI=26.66±1.81). The results from a methyl thiazolyl tetrazolium assay were consistent with the loading experimental data. Furthermore, elevated alkaline phosphatase activity and calcium content were observed in dynamic condition compared to static culture. In conclusion, this bioreactor system supplies a method of modulating the pH and PO₂ in defined ranges with only small fluctuations; it can be used as a physiological or pathological analog. Automatic control of the environment is a practical solution for long-term, steady-state culture for future commercialization.

Antiepileptic drug use and the occurrence of pressure ulcers among bedridden institutionalized elderly patients: a retrospective chart review.

PubMed

Arinzon, Zeev; Zeilig, Gabriel; Berner, Yitshal N; Adunsky, Abraham

2005-09-01

Phenytoin (PH) is indicated primarily for the control of grand mal and psychomotor seizures. However, topical PH has been used for the treatment of various types of ulcers, including pressure ulcers. The aim of this study was to investigate the possibility of a relationship between the use of oral PH and the prevalence of pressure ulcers among bedridden institutionalized elderly patients. This retrospective chart review was conducted in a state-run urban geriatric medical center in Israel and involved long-term bedridden institutionalized patients who were receiving chronic antiepileptic medication during the 7-year period between January 1996 and December 2003. The prevalence of pressure ulcers in patients who received treatment with PH alone or in combination with other antiepileptic drugs was compared with that in patients who received antiepileptic agents other than PH. The study analyzed data from the medical charts of 153 patients, 72 of whom received PH alone or in combination with other antiepileptic drugs, and 81 of whom received antiepileptic agents other than PH. Patients' mean (SD) age was 78.5 (7.2) years; 106 (69.3%) were women. All patients were totally dependent with respect to activities of daily living (mean Katz score, 2.0 [2.0]) and had severe cognitive decline (mean Mini-Mental State Examination score, 3.5 [3.3]). Pressure ulcers occurred in 9.7% of PH recipients and 27.2% of non-PH recipients (P = 0.006; chi2 = 7.55). In PH recipients, 85.7% of pressure ulcers were of mild to moderate severity (stage I or II), compared with 59.1% of ulcers in non-PH recipients; the difference between groups was not statistically significant. Four (18.2%) non-PH recipients and no PH recipients had stage IV pressure ulcers. In the PH group, 71.4% of patients had a pressure ulcer in only 1 anatomic location, compared with 22.7% of the non-PH group (P = 0.023; chi2 = 5.13); 28.6% of PH recipients and 63.6% of non-PH recipients had pressure ulcers in 2 or 3 anatomic locations; and 3 (13.6%) non-PH recipients and no PH recipients had pressure ulcers in > or = 4 areas. In the long-term bedridden institutionalized patients studied, those who received PH had lower rates of pressure ulcers, as well as less severe ulcers. PH may be a useful anticonvulsive agent in frail elderly patients, who are at risk for the development of pressure ulcers.

Instrument development and field application of the in situ pH Calibrator at the Ocean Observatory

NASA Astrophysics Data System (ADS)

Tan, C.; Ding, K.; Seyfried, W. E.

2012-12-01

A novel, self-calibrating instrument for in-situ measurement of pH in deep sea environments up to 4000 m has recently been developed. The device utilizes a compact fluid delivery system to perform measurement and two-point calibration of the solid state pH sensor array (Ir|IrOx| Ag|AgCl), which is sealed in a flow cell to enhance response time. The fluid delivery system is composed of a metering pump and valves, which periodically deliver seawater samples into the flow cell to perform measurements. Similarly, pH buffer solutions can be delivered into the flow cell to calibrate the electrodes under operational conditions. Sensor signals are acquired and processed by a high resolution (0.25 mV) datalogger circuit with a size of 114 mm×31 mm×25 mm. Eight input channels are available: two high impedance sensor input channels, two low impedance sensor input channel, two thermocouple input channels and two thermistor input channels. These eight channels provide adequate measurement flexibility to enhance applications in deep sea environments. The two high impedance channels of the datalogger are especially designed with the input impedance of 1016 Ω for YSZ (yittria-stabilized zirconia) ceramic electrodes characterized by the extremely low input bias current and high resistance. Field tests have been performed in 2008 by ROV at the depth up to 3200 m. Using the continuous power supply and TCP/IP network capability of the Monterey Accelerated Research System (MARS) ocean observatory, the so-called "pH Calibrator" has the capability of long term operation up to six months. In the observatory mode, the electronics are configured with DC-DC power converter modules and Ethernet to serial module to gain access to the science port of seafloor junction box. The pH Calibrator will be deployed at the ocean observatory in October and the in situ data will be on line on the internet. The pH Calibrator presents real time pH data at high pressures and variable temperatures, while the in situ calibration capability enhances the accuracy of electrochemical measurements of seawater pH, fulfilling the need for long term objectives for marine studies.

Engineering of acidic O/W emulsions with pectin.

PubMed

Alba, K; Sagis, L M C; Kontogiorgos, V

2016-09-01

Pectins with distinct molecular design were isolated by aqueous extraction at pH 2.0 or 6.0 and were examined in terms of their formation and stabilisation capacity of model n-alkane-in-water emulsions at acidic pH (pH 2.0). The properties and stability of the resulting emulsions were examined by means of droplet size distribution analysis, Lifshitz-Slyozov-Wagner modelling, bulk rheology, interfacial composition analysis, large-amplitude oscillatory surface dilatational rheology, electrokinetic analysis and fluorescence microscopy. Both pectin preparations were able to emulsify alkanes in water but exhibited distinct ageing characteristics. Emulsions prepared using pectin isolated at pH 6.0 were remarkably stable with respect to droplet growth after thirty days of ageing, while those prepared with pectin isolated at pH 2.0 destabilised rapidly. Examination of chemical composition of interfacial layers indicated multi-layered adsorption of pectins at the oil-water interface. The higher long-term stability of emulsions prepared with pectin isolated at high pH is attributed to mechanically stronger interfaces, the highly branched nature and the low hydrodynamic volume of the chains that result in effective steric stabilisation whereas acetyl and methyl contents do not contribute to the long-term stability. The present work shows that it is possible by tailoring the fine structure of pectin to engineer emulsions that operate in acidic environments. Copyright © 2016 Elsevier B.V. All rights reserved.

Short- and long-term effects of nicotine and the histone deacetylase inhibitor phenylbutyrate on novel object recognition in zebrafish.

PubMed

Faillace, M P; Pisera-Fuster, A; Medrano, M P; Bejarano, A C; Bernabeu, R O

2017-03-01

Zebrafish have a sophisticated color- and shape-sensitive visual system, so we examined color cue-based novel object recognition in zebrafish. We evaluated preference in the absence or presence of drugs that affect attention and memory retention in rodents: nicotine and the histone deacetylase inhibitor (HDACi) phenylbutyrate (PhB). The objective of this study was to evaluate whether nicotine and PhB affect innate preferences of zebrafish for familiar and novel objects after short- and long-retention intervals. We developed modified object recognition (OR) tasks using neutral novel and familiar objects in different colors. We also tested objects which differed with respect to the exploratory behavior they elicited from naïve zebrafish. Zebrafish showed an innate preference for exploring red or green objects rather than yellow or blue objects. Zebrafish were better at discriminating color changes than changes in object shape or size. Nicotine significantly enhanced or changed short-term innate novel object preference whereas PhB had similar effects when preference was assessed 24 h after training. Analysis of other zebrafish behaviors corroborated these results. Zebrafish were innately reluctant or prone to explore colored novel objects, so drug effects on innate preference for objects can be evaluated changing the color of objects with a simple geometry. Zebrafish exhibited recognition memory for novel objects with similar innate significance. Interestingly, nicotine and PhB significantly modified innate object preference.

Effects of Radiation on the Microbiota and Intestinal Inflammatory Disease

DTIC Science & Technology

2016-09-01

focal (GI tract) irradiation of mice on the bacterial and fungal microbiota. We have identified substantial changes in intestinal microbial...minimal acute symptoms, will develop long-term consequences of irradiation including permanent changes to bowel function and intestinal fibrosis, which...mice exposed to total body irradiation (TBI) or focal radiation to the GI tract. Timeline Status Site 1 (Stephen Shiao, MD, PhD) Site 2

Influence on bacterial communities under the condition of organic manure substituting nitrogen fertilizer in a 36-year field experiment of Chinese Mollisols

NASA Astrophysics Data System (ADS)

Ma, M.; Jiang, X.; Li, J.

2016-12-01

In recent years, the black soil of northeastern China has been degenerated over time owing to intensive farming practices and inappropriate uses of fertilizer. The objective of this research was to evaluate the impacts of long-term organic manure substituting inorganic nitrogen fertilizer on bacterial communities in Chinese Mollisols. Four treatments were sampled as follows, CK (without fertilizer), PK (inorganic fertilizers PK), NPK (inorganic fertilizers NPK) and MPK (inorganic fertilizers PK with manure). Quantitative PCR analysis of microbial community size and Illumina platform-based analysis of the V4 16S rRNA gene region were followed. The results showed, long term MPK application had no significant effect on soil pH, while NPK and PK application decreased it significantly. Soil OM showed the same trend with soil pH. Compared with CK, NPK treatment decreased gene copy numbers, whereas PK and MPK treatments increased them with a significant difference for MPK (P<0.05). There was no difference on ACE between samples, but long term NPK application significantly decreased CHAO and Shannon index. When comes to bacterial community, all samples were dominated by phyla Proteobacteria, which were represented by 29.59 to 35.73% of the sequences, followed by Acidobacteria (13.23-16.39%), Actinobacteria (9.26-10.83%), Verrucomicrobia (8.62-9.92%) and Planctomycetes (7.03-8.04%). Long term fertilization regimes had a significantly effect on bacterial β-diversity with the bacterial communities. Compared to the other treatments, long term application of NPK changed the bacterial communities conspicuously. Soil pH (F=8.6, P=0.002) and the concentration of OM (F=2.2, P=0.008) were the two most important contributors to the variation in bacterial communities. Our findings suggested that, long-term inorganic fertilizer regimes reduced the biodiversity and abundance of bacteria, and inorganic fertilizer plus manure increased microbial diversity and improved microbial composition.

Green Synthesis of Novel Polyaniline Nanofibers: Application in pH Sensing.

PubMed

Tanwar, Shivani; Ho, Ja-an Annie

2015-10-13

An optically active polyaniline nanomaterial (PANI-Nap), doped with (S)-naproxen, was developed and evaluated as a potent pH sensor. We synthesized the material in one pot by the addition of the dopant, (S)-naproxen, prior to polymerization, followed by the addition of the oxidizing agent (ammonium persulfate) that causes polymerization of the aniline. This green chemistry approach allowed us to take only 1 h to produce a water-soluble and stable nanomaterial. UV-visible spectroscopy, fluorescence spectroscopy, FT-IR spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) were used to characterize the designed nanomaterial. This nanomaterial exhibited excellent pH sensing properties and showed long term stability (up to one month) without loss of sensor performance.

The impact of low pH, low aragonite saturation state on calcifying corals: an in-situ study of ocean acidification from the "ojos" of Puerto Morelos, Mexico

NASA Astrophysics Data System (ADS)

Crook, E. D.; Paytan, A.; Potts, D. C.; Hernandez Terrones, L.; Rebolledo-Vieyra, M.

2010-12-01

Recent increases in atmospheric carbon dioxide have resulted in rising aqueous CO2 concentrations that lower the pH of the oceans (Caldeira and Wickett 2003, 2005, Doney et al., 2009). It is estimated that over the next 100 years, the pH of the surface oceans will decrease by ~0.4 pH units (Orr et al., 2005), which is expected to hinder the calcifying capabilities of numerous marine organisms. Previous field work (Hall-Spencer et al., 2008) indicates that ocean acidification will negatively impact calcifying species; however, to date, very little is known about the long-term impacts of ocean acidification from the in-situ study of coral reef ecosystems. The Yucatán Peninsula of Quintana Roo, Mexico, represents an ecosystem where naturally low pH groundwater (7.14-8.07) has been discharging offshore at highly localized points (called ojos) for millennia. We present preliminary chemical and biological data on a selection of ojos from lagoon sites in Puerto Morelos, Mexico. Our findings indicate a decrease in species richness and size with proximity to the low pH waters. We address the potential long-term implications of low pH, low aragonite saturation state on coral reef ecosystems.

Long-Term Trends in Calcifying Plankton and pH in the North Sea

PubMed Central

Beare, Doug; McQuatters-Gollop, Abigail; van der Hammen, Tessa; Machiels, Marcel; Teoh, Shwu Jiau; Hall-Spencer, Jason M.

2013-01-01

Relationships between six calcifying plankton groups and pH are explored in a highly biologically productive and data-rich area of the central North Sea using time-series datasets. The long-term trends show that abundances of foraminiferans, coccolithophores, and echinoderm larvae have risen over the last few decades while the abundances of bivalves and pteropods have declined. Despite good coverage of pH data for the study area there is uncertainty over the quality of this historical dataset; pH appears to have been declining since the mid 1990s but there was no statistical connection between the abundance of the calcifying plankton and the pH trends. If there are any effects of pH on calcifying plankton in the North Sea they appear to be masked by the combined effects of other climatic (e.g. temperature), chemical (nutrient concentrations) and biotic (predation) drivers. Certain calcified plankton have proliferated in the central North Sea, and are tolerant of changes in pH that have occurred since the 1950s but bivalve larvae and pteropods have declined. An improved monitoring programme is required as ocean acidification may be occurring at a rate that will exceed the environmental niches of numerous planktonic taxa, testing their capacities for acclimation and genetic adaptation. PMID:23658686

Chlorite, Biotite, Illite, Muscovite, and Feldspar Dissolution Kinetics at Variable pH and Temperatures up to 280 C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carroll, S.; Smith, M.; Lammers, K.

2016-10-05

Summary Sheet silicates and clays are ubiquitous in geothermal environments. Their dissolution is of interest because this process contributes to scaling reactions along fluid pathways and alteration of fracture surfaces, which could affect reservoir permeability. In order to better predict the geochemical impacts on long-term performance of engineered geothermal systems, we have measured chlorite, biotite, illite, and muscovite dissolution and developed generalized kinetic rate laws that are applicable over an expanded range of solution pH and temperature for each mineral. This report summarizes the rate equations for layered silicates where data were lacking for geothermal systems.

Chlorite dissolution kinetics at pH 3–10 and temperature to 275°C

DOE PAGES

Smith, Megan M.; Carroll, Susan A.

2015-12-02

Sheet silicates and clays are ubiquitous in geothermal environments. Their dissolution is of interest because this process contributes to scaling reactions along fluid pathways and alteration of fracture surfaces which could affect reservoir permeability. Here, in order to better predict the geochemical impacts on long-term performance of engineered geothermal systems, we have measured chlorite dissolution and developed a generalized kinetic rate law applicable over an expanded range of solution pH and temperature. Chlorite, (Mg,Al,Fe) 12(Si,Al) 8O 20(OH) 16, commonly occurs in many geothermal host rocks as either a primary mineral or alteration product.

Chlorite dissolution kinetics at pH 3–10 and temperature to 275°C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Megan M.; Carroll, Susan A.

Sheet silicates and clays are ubiquitous in geothermal environments. Their dissolution is of interest because this process contributes to scaling reactions along fluid pathways and alteration of fracture surfaces which could affect reservoir permeability. Here, in order to better predict the geochemical impacts on long-term performance of engineered geothermal systems, we have measured chlorite dissolution and developed a generalized kinetic rate law applicable over an expanded range of solution pH and temperature. Chlorite, (Mg,Al,Fe) 12(Si,Al) 8O 20(OH) 16, commonly occurs in many geothermal host rocks as either a primary mineral or alteration product.

Proteome modification in tomato plants upon long-term aluminum treatment

USDA-ARS?s Scientific Manuscript database

This study aimed to identify the aluminum (Al)-induced proteomes in tomato (Solanum lycopersicum, “Micro-Tom”) after long-term exposure to the stress factor. Plants were treated in Magnavaca’s solution (pH 4.5) supplemented with 7.5 uM Al3+ ion activity over a 4 month period beginning at the emergen...

Dryland soil chemical properties and crop yields affected by long-term tillage and cropping sequence

USDA-ARS?s Scientific Manuscript database

Information on the effect of long-term management on soil nutrients and chemical properties is scanty. We examined the 30-yr effect of tillage frequency and cropping sequence combination on dryland soil Olsen-P, K, Ca, Mg, Na, SO4-S, and Zn concentrations, pH, electrical conductivity (EC), and catio...

Pre-emptive liver transplantation for primary hyperoxaluria (PH-I) arrests long-term renal function deterioration.

PubMed

Perera, M Thamara P R; Sharif, Khalid; Lloyd, Carla; Foster, Katharine; Hulton, Sally A; Mirza, Darius F; McKiernan, Patrick J

2011-01-01

Primary hyperoxaluria-I (PH-I) is a serious metabolic disease resulting in end-stage renal disease. Pre-emptive liver transplantation (PLT) for PH-I is an option for children with early diagnosis. There is still little information on its effect on long-term renal function in this situation. Long-term assessment of renal function was conducted using Schwartz's formula (estimated glomerular filtration rate-eGFR) in four children (Group A) undergoing PLT between 2002 and 2008, and a comparison was done with eight gender- and sex-matched controls (Group B) having liver transplantation for other indications. All patients received a liver graft from a deceased donor. Median follow-up for the two groups was 64 and 94 months, respectively. One child in Group A underwent re-transplantation due to hepatic artery thrombosis, while acute rejection was seen in one. A significant difference was seen in eGFR at transplant (81 vs 148 mL/min/1.73 m(2)) with greater functional impairment seen in the study population. In Group A, renal function reduced by 21 and 11% compared with 37 and 35% in Group B at 12 and 24 months, respectively. At 2 years post-transplantation, there was no significant difference in eGFR between the two groups (72 vs 100 mL/min/1.73 m(2), respectively; P = 0.06). Renal function remains relatively stable following pre-emptive LTx for PH-I. With early diagnosis of PH-I, isolated liver transplantation may prevent progression to end-stage renal disease and the need for renal transplantation.

Internal pH regulation facilitates in situ long-term acclimation of massive corals to end-of-century carbon dioxide conditions.

PubMed

Wall, M; Fietzke, J; Schmidt, G M; Fink, A; Hofmann, L C; de Beer, D; Fabricius, K E

2016-08-01

The resilience of tropical corals to ocean acidification depends on their ability to regulate the pH within their calcifying fluid (pHcf). Recent work suggests pHcf homeostasis under short-term exposure to pCO2 conditions predicted for 2100, but it is still unclear if pHcf homeostasis can be maintained throughout a corals lifetime. At CO2 seeps in Papua New Guinea, massive Porites corals have grown along a natural seawater pH gradient for decades. This natural gradient, ranging from pH 8.1-7.4, provides an ideal platform to determine corals' pHcf (using boron isotopes). Porites maintained a similar pHcf (~8.24) at both a control (pH 8.1) and seep-influenced site (pH 7.9). Internal pHcf was slightly reduced (8.12) at seawater pH 7.6, and decreased to 7.94 at a site with a seawater pH of 7.4. A growth response model based on pHcf mirrors the observed distribution patterns of this species in the field. We suggest Porites has the capacity to acclimate after long-time exposure to end-of-century reduced seawater pH conditions and that strong control over pHcf represents a key mechanism to persist in future oceans. Only beyond end-of-century pCO2 conditions do they face their current physiological limit of pH homeostasis and pHcf begins to decrease.

Levels of uric acid may predict the future development of pulmonary hypertension in systemic lupus erythematosus: a seven-year follow-up study.

PubMed

Castillo-Martínez, D; Marroquín-Fabián, E; Lozada-Navarro, A C; Mora-Ramírez, M; Juárez, M; Sánchez-Muñoz, F; Vargas-Barrón, J; Sandoval, J; Amezcua-Guerra, L M

2016-01-01

The objective of this paper is to assess whether pulmonary hypertension (PH) may be detected at one point in time or longitudinally predicted by serum uric acid (sUA) levels in systemic lupus erythematosus (SLE). We conducted a post-hoc analysis of a long-term followed cohort of Mexican SLE patients. Echocardiography-based definitions of PH by the ESC/ERS/ISHLT and its associations with clinical and laboratory data on enrollment were studied. Especially, the impact that sUA levels at baseline may have on the future development of PH in patients with normal pulmonary artery systolic pressure (PASP) was explored. Out of the 156 SLE patients originally enrolled in the cohort, 44 met the inclusion criteria for the present study and were grouped as having (n =10) or not having (n = 34) PH. At baseline, sUA levels of 5.83 ± 1.79 and 5.82 ± 1.97 mg/dl (p = ns) were found in patients with and without PH, respectively. No association between PASP and other markers was found. In patients with normal PASP, the presence of sUA ≥ 7 mg/dl at baseline predicted future development of PH (relative risk 8.5, 1.0009 to 72; p = 0.04). In SLE, sUA levels at one point in time are useless to detect PH. However, steady hyperuricemia may predict the future development of PH in patients with normal PASP at baseline. © The Author(s) 2015.

Fluorescent Silicon Nanorods-Based Ratiometric Sensors for Long-Term and Real-Time Measurements of Intracellular pH in Live Cells.

PubMed

Chu, Binbin; Song, Bin; Ji, Xiaoyuan; Su, Yuanyuan; Wang, Houyu; He, Yao

2017-11-21

Long-term and real-time investigation of the dynamic process of pH i changes is critically significant for understanding the related pathogenesis of diseases and the design of intracellular drug delivery systems. Herein, we present a one-step synthetic strategy to construct ratiometric pH sensors, which are made of europium (Eu)-doped one-dimensional silicon nanorods (Eu@SiNRs). The as-prepared Eu@SiNRs have distinct emission maxima peaks at 470 and 620 nm under 405 nm excitation. Of particular note, the fluorescence emission intensity at 470 nm decreases along with the increase of pH, while the one at 620 nm is nearly unaffected by pH changes, making Eu@SiNRs a feasible probe for pH sensing ratiometrically. Moreover, Eu@SiNRs are found to be responsive to a broad pH range (ca. 3-9), biocompatible (e.g., ∼100% of cell viability during 24 h treatment) and photostable (e.g., ∼10% loss of intensity after 40 min continuous UV irradiation). Taking advantages of these merits, we employ Eu@SiNRs for the visualization of the cytoplasmic alkalization process mediated by nigericin in living cells, for around 30 min without interruption, revealing important information for understanding the dynamic process of pH i fluctuations.

Effects of Radiation on the Microbiota and Intestinal Inflammatory Disease

DTIC Science & Technology

2016-09-01

completion of initial experiments investigating the effect of whole body and focal (GI tract) irradiation of mice on the bacterial and fungal microbiota. We...acute symptoms, will develop long-term consequences of irradiation including permanent changes to bowel function and intestinal fibrosis, which can...exposed to total body irradiation (TBI) or focal radiation to the GI tract. Timeline Status Site 1 (Stephen Shiao, MD, PhD) Site 2

An attempt to optimize potassium sorbate use to preserve low pH (4.5-5.5) intermediate moisture bakery products by modelling Eurotium spp., Aspergillus spp. and Penicillium corylophilum growth.

PubMed

Guynot, M Elena; Marín, Sonia; Sanchis, Vicente; Ramos, Antonio J

2005-05-25

Mould growth was modelled on fermented bakery product analogues (FBPA) of two different pH (4.5 and 5.5), different water activity (a(w)) levels (0.80-0.90) and potassium sorbate concentrations (0-0.3%) by using seven moulds commonly causing spoilage of bakery products (Eurotium spp., Aspergillus spp. and Penicillium corylophilum). For the description of fungal growth (growth rates) as a function of a(w), potassium sorbate concentration and pH, 10-terms polynomial models were developed. Modelling enables prediction of spoilage during storage as a function of the factors affecting fungal growth. At pH 4.5 the concentration of potassium sorbate could be reduced to some extent only at low levels of a(w), whereas at pH 5.5 fungal growth was observed even by adding 0.3% of potassium sorbate. However, this preservative could be a valuable alternative as antifungal in such bakery product, of slightly acidic pH, if a long shelf life has not to be achieved.

Miniaturized pH Sensors Based on Zinc Oxide Nanotubes/Nanorods

PubMed Central

Fulati, Alimujiang; Ali, Syed M.Usman; Riaz, Muhammad; Amin, Gul; Nur, Omer; Willander, Magnus

2009-01-01

ZnO nanotubes and nanorods grown on gold thin film were used to create pH sensor devices. The developed ZnO nanotube and nanorod pH sensors display good reproducibility, repeatability and long-term stability and exhibit a pH-dependent electrochemical potential difference versus an Ag/AgCl reference electrode over a large dynamic pH range. We found the ZnO nanotubes provide sensitivity as high as twice that of the ZnO nanorods, which can be ascribed to the fact that small dimensional ZnO nanotubes have a higher level of surface and subsurface oxygen vacancies and provide a larger effective surface area with higher surface-to-volume ratio as compared to ZnO nanorods, thus affording the ZnO nanotube pH sensor a higher sensitivity. Experimental results indicate ZnO nanotubes can be used in pH sensor applications with improved performance. Moreover, the ZnO nanotube arrays may find potential application as a novel material for measurements of intracellular biochemical species within single living cells. PMID:22291545

Long-term stream chemistry monitoring on the fernow experiment forest: implications for sustainable management of hardwood forests

Treesearch

Mary Beth Adams; James N. Kochenderfer

2007-01-01

Long-term monitoring of stream chemistry of forested watersheds on the Fernow Experimental Forest in West Virginia has been conducted to determine the effects of both human induced and natural disturbances on nutrient cycling and stream chemistry. We compare mean annual stream water pH, and nitrate (NO3), sulfate (SO4), and...

Liquid Crystalline Properties of Amyloid Protein Fibers in Water

NASA Astrophysics Data System (ADS)

Mezzenga, Raffaele; Jung, Jin-Mi

2010-03-01

We have studied the liquid crystalline features of two colloidal systems consisting of food protein amyloid fibrils in water, obtained by heat-denaturation and aggregation of β-lactoglobulin, a globular dairy protein. The resulting fibrils, have a monodisperse cross section of about 4 nm and two groups of polydisperse contour lengths: (i) fibrils 1-10 μm long, showing semiflexible polyeletrolyte-like behaviour and (ii) rigid rods 100-200 nm long. In both systems, the fibers are highly charged (+5 e/nm) and stable in water at low ionic strength (0.01 M) and low pH (pH 2). The physical properties of these systems are studied using a polymer physics approach and phase diagrams of these two systems are obtained by changing concentration and pH. Both systems exhibit rich phase behaviours. Interestingly, the experimentally measured isotropic-nematic phase transition was found to occur at concentrations more than one order of magnitude lower than what expected based on Onsager theory. Experimental results are revisited in terms of the Flory theory developed for rigid polymers in solvent of varying conditions.

Benthic foraminifera show some resilience to ocean acidification in the northern Gulf of California, Mexico.

PubMed

Pettit, L R; Hart, M B; Medina-Sánchez, A N; Smart, C W; Rodolfo-Metalpa, R; Hall-Spencer, J M; Prol-Ledesma, R M

2013-08-30

Extensive CO2 vents have been discovered in the Wagner Basin, northern Gulf of California, where they create large areas with lowered seawater pH. Such areas are suitable for investigations of long-term biological effects of ocean acidification and effects of CO2 leakage from subsea carbon capture storage. Here, we show responses of benthic foraminifera to seawater pH gradients at 74-207m water depth. Living (rose Bengal stained) benthic foraminifera included Nonionella basispinata, Epistominella bradyana and Bulimina marginata. Studies on foraminifera at CO2 vents in the Mediterranean and off Papua New Guinea have shown dramatic long-term effects of acidified seawater. We found living calcareous benthic foraminifera in low pH conditions in the northern Gulf of California, although there was an impoverished species assemblage and evidence of post-mortem test dissolution. Copyright © 2013 Elsevier Ltd. All rights reserved.

Environmental controls on denitrifying communities and denitrification rates--Insights from molecular methods

USGS Publications Warehouse

Wallenstein, Matthew D.; Myrold, David D.; Firestone, Mary; Voytek, Mary

2006-01-01

The advent of molecular techniques has improved our understanding of the microbial communities responsible for denitrification and is beginning to address their role in controlling denitrification processes. There is a large diversity of bacteria, archaea, and fungi capable of denitrification, and their community composition is structured by long-term environmental drivers. The range of temperature and moisture conditions, substrate availability, competition, and disturbances have long-lasting legacies on denitrifier community structure. These communities may differ in physiology, environmental tolerances to pH and O2, growth rate, and enzyme kinetics. Although factors such as O2, pH, C availability, and NO3− pools affect instantaneous rates, these drivers act through the biotic community. This review summarizes the results of molecular investigations of denitrifier communities in natural environments and provides a framework for developing future research for addressing connections between denitrifier community structure and function.

Dramatic Variability of the Carbonate System at a Temperate Coastal Ocean Site (Beaufort, North Carolina, USA) Is Regulated by Physical and Biogeochemical Processes on Multiple Timescales

PubMed Central

Johnson, Zackary I.; Wheeler, Benjamin J.; Blinebry, Sara K.; Carlson, Christina M.; Ward, Christopher S.; Hunt, Dana E.

2013-01-01

Increasing atmospheric carbon dioxide (CO2) from anthropogenic sources is acidifying marine environments resulting in potentially dramatic consequences for the physical, chemical and biological functioning of these ecosystems. If current trends continue, mean ocean pH is expected to decrease by ~0.2 units over the next ~50 years. Yet, there is also substantial temporal variability in pH and other carbon system parameters in the ocean resulting in regions that already experience change that exceeds long-term projected trends in pH. This points to short-term dynamics as an important layer of complexity on top of long-term trends. Thus, in order to predict future climate change impacts, there is a critical need to characterize the natural range and dynamics of the marine carbonate system and the mechanisms responsible for observed variability. Here, we present pH and dissolved inorganic carbon (DIC) at time intervals spanning 1 hour to >1 year from a dynamic, coastal, temperate marine system (Beaufort Inlet, Beaufort NC USA) to characterize the carbonate system at multiple time scales. Daily and seasonal variation of the carbonate system is largely driven by temperature, alkalinity and the balance between primary production and respiration, but high frequency change (hours to days) is further influenced by water mass movement (e.g. tides) and stochastic events (e.g. storms). Both annual (~0.3 units) and diurnal (~0.1 units) variability in coastal ocean acidity are similar in magnitude to 50 year projections of ocean acidity associated with increasing atmospheric CO2. The environmental variables driving these changes highlight the importance of characterizing the complete carbonate system rather than just pH. Short-term dynamics of ocean carbon parameters may already exert significant pressure on some coastal marine ecosystems with implications for ecology, biogeochemistry and evolution and this shorter term variability layers additive effects and complexity, including extreme values, on top of long-term trends in ocean acidification. PMID:24358377

Storability Investigations of Water Long-Term Storage Evaluation

DTIC Science & Technology

1974-12-01

of 17 - 4PH H-1025 Stainless Steel Containers after 19 Storage in Oxygen Free Water, Magnification 3/5X 11 Interior of 17 - 4PH 1-1025 Stainless Steel...Stainless Steel Containers 21 Adherent Metallic Granular Material Found in 17 - 4PH Staluiess 35 Steel Containers. Lower Photo Is Bright Area Shown in Figure...material. Hence, the selected materials are: 304L stainless steel, A-286, 17 - 4PH stainless steel, Inconel 718 and 6A1-4V titanium. During fabrication, some

Evaluation of long-term survival: use of diagnostics and robust estimators with Cox's proportional hazards model.

PubMed

Valsecchi, M G; Silvestri, D; Sasieni, P

1996-12-30

We consider methodological problems in evaluating long-term survival in clinical trials. In particular we examine the use of several methods that extend the basic Cox regression analysis. In the presence of a long term observation, the proportional hazard (PH) assumption may easily be violated and a few long term survivors may have a large effect on parameter estimates. We consider both model selection and robust estimation in a data set of 474 ovarian cancer patients enrolled in a clinical trial and followed for between 7 and 12 years after randomization. Two diagnostic plots for assessing goodness-of-fit are introduced. One shows the variation in time of parameter estimates and is an alternative to PH checking based on time-dependent covariates. The other takes advantage of the martingale residual process in time to represent the lack of fit with a metric of the type 'observed minus expected' number of events. Robust estimation is carried out by maximizing a weighted partial likelihood which downweights the contribution to estimation of influential observations. This type of complementary analysis of long-term results of clinical studies is useful in assessing the soundness of the conclusions on treatment effect. In the example analysed here, the difference in survival between treatments was mostly confined to those individuals who survived at least two years beyond randomization.

Development of Online Spectroscopic pH Monitoring for Nuclear Fuel Reprocessing Plants: Weak Acid Schemes.

PubMed

Casella, Amanda J; Ahlers, Laura R H; Campbell, Emily L; Levitskaia, Tatiana G; Peterson, James M; Smith, Frances N; Bryan, Samuel A

2015-05-19

In nuclear fuel reprocessing, separating trivalent minor actinides and lanthanide fission products is extremely challenging and often necessitates tight pH control in TALSPEAK (Trivalent Actinide-Lanthanide Separation by Phosphorus reagent Extraction from Aqueous Komplexes) separations. In TALSPEAK and similar advanced processes, aqueous pH is one of the most important factors governing the partitioning of lanthanides and actinides between an aqueous phase containing a polyaminopolycarboxylate complexing agent and a weak carboxylic acid buffer and an organic phase containing an acidic organophosphorus extractant. Real-time pH monitoring would significantly increase confidence in the separation performance. Our research is focused on developing a general method for online determination of the pH of aqueous solutions through chemometric analysis of Raman spectra. Spectroscopic process-monitoring capabilities, incorporated in a counter-current centrifugal contactor bank, provide a pathway for online, real-time measurement of solution pH. The spectroscopic techniques are process-friendly and can be easily configured for online applications, whereas classic potentiometric pH measurements require frequent calibration/maintenance and have poor long-term stability in aggressive chemical and radiation environments. Raman spectroscopy discriminates between the protonated and deprotonated forms of the carboxylic acid buffer, and the chemometric processing of the Raman spectral data with PLS (partial least-squares) regression provides a means to quantify their respective abundances and therefore determine the solution pH. Interpretive quantitative models have been developed and validated under a range of chemical composition and pH conditions using a lactic acid/lactate buffer system. The developed model was applied to new spectra obtained from online spectral measurements during a solvent extraction experiment using a counter-current centrifugal contactor bank. The model predicted the pH of this validation data set within 11% for pH > 2, thus demonstrating that this technique could provide the capability of monitoring pH online in applications such as nuclear fuel reprocessing.

Impact of pre-transplant pulmonary hypertension on survival after heart transplantation: a UNOS registry analysis.

PubMed

Vakil, Kairav; Duval, Sue; Sharma, Alok; Adabag, Selcuk; Abidi, Kashan Syed; Taimeh, Ziad; Colvin-Adams, Monica

2014-10-20

Severe pre-transplant pulmonary hypertension (PH) has been associated with adverse short-term clinical outcomes after heart transplantation in relatively small single-center studies. The impact of pre-transplant PH on long-term survival after heart transplantation has not been examined in a large, multi-center cohort. Adults (≥18 years) who underwent first time heart transplantation in the United States between 1987 and 2012 were retrospectively identified from the United Network for Organ Sharing registry. Pre-transplant PH was classified as mild, moderate, or severe based on pulmonary vascular resistance (PVR), trans-pulmonary gradient (TPG), and pulmonary artery (PA) mean pressure. Primary outcome was all-cause mortality. Data from 26,649 heart transplant recipients (mean age 52±12 years; 76% male; 76% Caucasian) were analyzed. During a mean follow-up of 5.7±4.8 years, there were 10,334 (39%) deaths. Pre-transplant PH (PVR≥2.5 WU) was a significant predictor of mortality (hazard ratio 1.10, 95% confidence interval 1.05-1.14, p<0.0001) in multivariable analysis. However, the severity of pre-transplant PH (mild/moderate vs. severe) did not affect short or long-term survival. Similarly, even in patients who were supported with either a left ventricular assist device or a total artificial heart prior to transplant, severe pre-transplant PH was not associated with worse survival when compared to patients with mild/moderate pre-transplant PH. Pre-transplant PH (PVR≥2.5 WU) is associated with a modest increase in mortality when compared to patients without pre-transplant PH. However, the severity of pre-transplant PH, assessed by PVR, TPG, or mean PA pressure, is not a discriminating factor for poor survival in patients listed for heart transplantation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Long-term survival of Streptococcus pyogenes in rich media is pH-dependent

PubMed Central

McShan, William M.

2012-01-01

The mechanisms that allow Streptococcus pyogenes to survive and persist in the human host, often in spite of antibiotic therapy, remain poorly characterized. Therefore, the determination of culture conditions for long-term studies is crucial to advancement in this field. Stationary cultures of S. pyogenes strain NZ131 and its spontaneous small-colony variant OK171 were found to survive in rich medium for less than 2 weeks, and this inability to survive resulted from the acidification of the medium to below pH 5.5, which the cells did not tolerate for longer than 6–7 days. The growth of NZ131 resulted in acidification of the culture to below pH 5.5 by the onset of stationary phase, and the loss of viability occurred in a linear fashion. These results were also found to be true for M49 strain CS101 and for M1 strain SF370. The S. pyogenes strains could be protected from killing by the addition of a buffer that stabilized the pH of the medium at pH 6.5, ensuring bacterial survival to at least 70 days. By contrast, increasing the glucose added to the medium accelerated the loss of culture viability in strain NZ131 but not OK171, suggesting that the small-colony variant is altered in glucose uptake or metabolism. Similarly, acidification of the medium prior to inoculation or at the middle of exponential phase resulted in growth inhibition of all strains. These results suggest that control of the pH is crucial for establishing long-term cultures of S. pyogenes. PMID:22361943

A randomised controlled trial of ablation of Barrett's oesophagus with multipolar electrocoagulation versus argon plasma coagulation in combination with acid suppression: long term results

PubMed Central

Sharma, P; Wani, S; Weston, A P; Bansal, A; Hall, M; Mathur, S; Prasad, A; Sampliner, R E

2006-01-01

Background Many modalities have been used to ablate Barrett's oesophagus (BO). However, long term results and comparative effectiveness are unknown. Aims Our aim was to compare the long term efficacy of achieving complete reversal (endoscopic and histological) between multipolar electrocoagulation (MPEC) and argon plasma coagulation (APC) in BO patients and assess factors influencing successful ablation. Methods Patients with BO, 2–6 cm long, underwent 24 hour pH testing on proton pump inhibitor (PPI) therapy. Patients were then randomised by BO length to undergo ablation with MPEC or APC every 4–8 weeks until endoscopic reversal or maximal of six treatment sessions. Results Thirty five BO patients have been followed for at least two years following endoscopic ablation, 16 treated with MPEC and 19 with APC. There was complete reversal of BO in 24 patients (69%); 75% with MPEC and 63% with APC (p = 0.49). There was no difference in the number of sessions required in the two groups. There was no difference in age, pH results, BO length, PPI dose, or hiatal hernia size between patients with and without complete reversal. One patient developed an oesophageal stricture but there were no major complications such as bleeding or perforation. Conclusions In BO patients treated with MPEC or APC in combination with acid suppression, at long term follow up, complete reversal of BO can be maintained in approximately 70% of patients, irrespective of the technique. There are no predictors associated with achieving complete reversal of BO. Continued surveillance is still indicated in the post ablative setting. As yet, these techniques are not ready for clinical application (other than for high grade dysplasia or early oesophageal adenocarcinoma) and cannot be offered outside the research arena. PMID:16905695

Long-term nitrogen fertilization decreases bacterial diversity and favors the growth of Actinobacteria and Proteobacteria in agro-ecosystems across the globe.

PubMed

Dai, Zhongmin; Su, Weiqin; Chen, Huaihai; Barberán, Albert; Zhao, Haochun; Yu, Mengjie; Yu, Lu; Brookes, Philip C; Schadt, Christopher W; Chang, Scott X; Xu, Jianming

2018-04-12

Long-term elevated nitrogen (N) input from anthropogenic sources may cause soil acidification and decrease crop yield, yet the response of the belowground microbial community to long-term N input alone or in combination with phosphorus (P) and potassium (K) is poorly understood. We explored the effect of long-term N and NPK fertilization on soil bacterial diversity and community composition using meta-analysis of a global dataset. Nitrogen fertilization decreased soil pH, and increased soil organic carbon (C) and available N contents. Bacterial taxonomic diversity was decreased by N fertilization alone, but was increased by NPK fertilization. The effect of N fertilization on bacterial diversity varied with soil texture and water management, but was independent of crop type or N application rate. Changes in bacterial diversity were positively related to both soil pH and organic C content under N fertilization alone, but only to soil organic C under NPK fertilization. Microbial biomass C decreased with decreasing bacterial diversity under long-term N fertilization. Nitrogen fertilization increased the relative abundance of Proteobacteria and Actinobacteria, but reduced the abundance of Acidobacteria, consistent with the general life history strategy theory for bacteria. The positive correlation between N application rate and the relative abundance of Actinobacteria indicates that increased N availability favored the growth of Actinobacteria. This first global analysis of long-term N and NPK fertilization that differentially affects bacterial diversity and community composition provides a reference for nutrient management strategies for maintaining belowground microbial diversity in agro-ecosystems worldwide. © 2018 John Wiley & Sons Ltd.

Different mechanisms for acid weathering of crystalline basalt vs. basaltic glass and implications for detection on Mars

NASA Astrophysics Data System (ADS)

Horgan, B. H. N.; Smith, R.; Christensen, P. R.; Cloutis, E.

2016-12-01

Silica-rich acid leached rinds and coatings occur in volcanic environments on Earth and have been identified using orbital spectroscopy on Mars, but their development is poorly understood. We simulated long-term open-system acid weathering in a laboratory by repeatedly submerging and rinsing crystalline and glassy basalts in pH 1 and 3 acidic solutions for 220 days. Visible/near-infrared (VNIR; 0.3-2.5 μm) and thermal-infrared (TIR; 5-50 μm) spectra of the samples were compared to their microscopic properties from scanning electron microscopy (SEM). While previous studies have shown that exposure to moderately low pH ( 3) solutions can produce mineral precipitates, we find that there is very little spectral or microphysical effect on the underlying parent material. In contrast, materials exposed to very low pH ( 1) solutions were visibly altered in SEM images, and contained regions enriched in amorphous silica. These samples exhibited clear silica VNIR and TIR spectral signatures that increased in intensity with their glass content. In addition, glass exposed to low pH solutions often exhibited blue and concave up VNIR slopes. SEM indicates that these spectral differences correspond to different modes of alteration. In glass, low pH alteration occurs only at the surface and produces a silica-enriched rind. In more crystalline samples, alteration penetrates the interior to cause dissolution and replacement by silica. Thus, along with the pH of the aqueous environment, the crystallinity of a rock can greatly affect the way and the degree to which it is weathered. Because alteration is restricted to the surface of glassy materials, bulk glass is more stable than crystalline basalt under long-term acidic leaching. Leached glasses are consistent with OMEGA and TES spectra of the martian northern lowlands, and may contribute to the high-silica phases detected globally in TES Surface Type 2. Thus, both glass-rich deposits and acidic weathering may have been widespread on Mars.

Pulmonary hypertension in chronic obstructive pulmonary disease and interstitial lung diseases.

PubMed

Weitzenblum, Emmanuel; Chaouat, Ari; Canuet, Matthieu; Kessler, Romain

2009-08-01

Pulmonary hypertension (PH) is a common complication of chronic respiratory diseases and particularly of chronic obstructive pulmonary disease (COPD) and interstitial lung diseases (ILD). Owing to its frequency COPD is by far the most common cause of PH. It is generally a mild to moderate PH, pulmonary artery mean pressure (PAP) usually ranging between 20 and 25 mm Hg, but PH may worsen during exercise, sleep, and particularly during exacerbations of the disease. These acute increases in PAP may lead to the development of right heart failure. A small proportion of COPD patients may present "disproportionate" PH defined by a resting PAP >35 to 40 mm Hg. The prognosis is particularly poor in these patients. PH is relatively frequent in advanced ILD and particularly in idiopathic pulmonary fibrosis. As in COPD the diagnosis is suggested by Doppler echocardiography, but the confirmation still requires right heart catheterization. As in COPD, functional (alveolar hypoxia) and morphological factors (vascular remodeling, destruction of the pulmonary parenchyma) explain the elevation of pulmonary vascular resistance that leads to PH. Also as in COPD PH is most often mild to moderate. In ILD the presence of PH predicts a poor prognosis. The treatment of PH relies on long-term oxygen therapy. "New" vasodilator drugs have rarely been used in COPD and ILD patients exhibiting severe PH. In advanced ILD the presence of PH is a supplemental argument for considering lung transplantation.

Launching a Geoscience Career: Insights Gained from MS PHD'S Beyond the PhD

NASA Astrophysics Data System (ADS)

Guzman, W. I.; Johnson, A.; Williamson Whitney, V.; Jansma, P. E.; Huggans, M. J.; Ricciardi, L.

2013-05-01

The Beyond the PhD (B-PhD) Professional Development Program is the newest addition to the Minorities Striving and Pursuing Higher Degrees of Success (MS PHD'S®) Professional Development Program in Earth System Science. This exciting new program is designed to facilitate the development of a new community of underrepresented minority (URM) doctoral candidates and recent doctorate degree recipients in Earth system science (ESS)-related fields. Building upon MS PHD'S extensive professional development activities provided to URM undergraduate and graduate students, B-PhD's vision is to encourage and support URM doctoral students and early career PhD's in becoming part of the global workforce. (Since its inception in 2003, MSPHD'S supports 213 participants of which 42 have achieved the doctoral degree and another 71 are enrolled in doctoral programs.) By providing customized support and advocacy for participants, B-PhD facilitates smoother and informed transitions from graduate school to postdoctoral and tenure-track positions, as well as other "first" jobs in academia, government, industry, and non-profit organizations. In 2011, the first conference for 18 doctoral candidate and recent graduates was hosted at the University of Texas at Arlington's (UTA) College of Science. Using a format of guest speakers, brown bag discussions, and interactive breakout sessions, participants engaged in sessions entitled "Toolkits for Success in Academia, Business and Industry, Federal Government and Non-Profits", "Defining Short, Mid and Long Term Career Goals", "Accessing and Refining Skill Sets and Other Door Openers", "International Preparation and Opportunities", "Paying it Forward/Lifting as You Climb", and "Customized Strategies for Next Steps". This presentation will discuss outcomes from this pilot project, the use of social media to track and support ongoing B-PhD activities, and objectives for future B-PhD workshops.

IN SITU SOURCE TREATMENT OF CR(VI) USING A FE(II)-BASED REDUCTANT BLEND: LONG-TERM MONITORING AND EVALUATION

EPA Science Inventory

The long-term effectiveness of a FeSO4 + Na2S2O4 reductant solution blend for in situ saturated zone treatment of dissolved and solid phase Cr(VI) in a high pH chromite ore processing solid waste (COPSW) fill material was investigated. Two field pilot injection studies were cond...

Analysis of long-term bacterial vs. chemical Fe(III) oxide reduction kinetics

NASA Astrophysics Data System (ADS)

Roden, Eric E.

2004-08-01

Data from studies of dissimilatory bacterial (10 8 cells mL -1 of Shewanella putrefaciens strain CN32, pH 6.8) and ascorbate (10 mM, pH 3.0) reduction of two synthetic Fe(III) oxide coated sands and three natural Fe(III) oxide-bearing subsurface materials (all at ca. 10 mmol Fe(III) L -1) were analyzed in relation to a generalized rate law for mineral dissolution (J t/m 0 = k'(m/m 0) γ, where J t is the rate of dissolution and/or reduction at time t, m 0 is the initial mass of oxide, and m/m 0 is the unreduced or undissolved mineral fraction) in order to evaluate changes in the apparent reactivity of Fe(III) oxides during long-term biological vs. chemical reduction. The natural Fe(III) oxide assemblages demonstrated larger changes in reactivity (higher γ values in the generalized rate law) compared to the synthetic oxides during long-term abiotic reductive dissolution. No such relationship was evident in the bacterial reduction experiments, in which temporal changes in the apparent reactivity of the natural and synthetic oxides were far greater (5-10 fold higher γ values) than in the abiotic reduction experiments. Kinetic and thermodynamic considerations indicated that neither the abundance of electron donor (lactate) nor the accumulation of aqueous end-products of oxide reduction (Fe(II), acetate, dissolved inorganic carbon) are likely to have posed significant limitations on the long-term kinetics of oxide reduction. Rather, accumulation of biogenic Fe(II) on residual oxide surfaces appeared to play a dominant role in governing the long-term kinetics of bacterial crystalline Fe(III) oxide reduction. The experimental findings together with numerical simulations support a conceptual model of bacterial Fe(III) oxide reduction kinetics that differs fundamentally from established models of abiotic Fe(III) oxide reductive dissolution, and indicate that information on Fe(III) oxide reactivity gained through abiotic reductive dissolution techniques cannot be used to predict long-term patterns of reactivity toward enzymatic reduction at circumneutral pH.

A novel environmental chamber for neuronal network multisite recordings.

PubMed

Biffi, E; Regalia, G; Ghezzi, D; De Ceglia, R; Menegon, A; Ferrigno, G; Fiore, G B; Pedrocchi, A

2012-10-01

Environmental stability is a critical issue for neuronal networks in vitro. Hence, the ability to control the physical and chemical environment of cell cultures during electrophysiological measurements is an important requirement in the experimental design. In this work, we describe the development and the experimental verification of a closed chamber for multisite electrophysiology and optical monitoring. The chamber provides stable temperature, pH and humidity and guarantees cell viability comparable to standard incubators. Besides, it integrates the electronics for long-term neuronal activity recording. The system is portable and adaptable for multiple network housings, which allows performing parallel experiments in the same environment. Our results show that this device can be a solution for long-term electrophysiology, for dual network experiments and for coupled optical and electrical measurements. Copyright © 2012 Wiley Periodicals, Inc.

Accelerated barrier recovery and enhancement of the barrier integrity and properties by topical application of a pH 4 compared to a pH 5.8 w/o emulsion in aged skin.

PubMed

Angelova-Fischer, I; Fischer, T W; Abels, C; Zillikens, D

2018-03-25

Increased skin surface pH is an important host-related factor for deteriorated barrier function in the aged. We investigated whether restoration of the skin pH through topical application of a water-in-oil (w/o) emulsion with pH 4 improved the barrier homeostasis in aged skin and compared the effects to an identical galenic formulation with pH 5.8. The effects of the test formulations on the barrier recovery were investigated by repeated measurements of transepidermal water loss (TEWL) and skin pH 3 h, 6 h and 24 h after acetone-induced impairment of the barrier function in aged skin. The long-term effects of the pH 4 and pH 5.8 emulsions were analyzed by investigation of the barrier integrity/cohesion, the skin surface pH and the skin roughness and scaliness before and after a 4-week, controlled application of the formulations. The application of the pH 4 emulsion accelerated the barrier recovery in aged skin: 3 h and 6 h after acetone-induced barrier disruption the differences in the TEWL recovery between the pH4-treated and acetone control field were significant. Furthermore, the long-term application of the pH 4 formulation resulted in significantly decreased skin pH, enhanced barrier integrity and reduced skin surface roughness and scaliness. At the same time points, the pH 5.8 formulation exerted only minor effects on the barrier function parameters. Exogenous acidification through topical application of a w/o emulsion with pH 4 leads to improvement of the barrier function and maintenance of the barrier homeostasis in aged skin. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Oyster reproduction is compromised by acidification experienced seasonally in coastal regions.

PubMed

Boulais, Myrina; Chenevert, Kyle John; Demey, Ashley Taylor; Darrow, Elizabeth S; Robison, Madison Raine; Roberts, John Park; Volety, Aswani

2017-10-16

Atmospheric carbon dioxide concentrations have been rising during the past century, leading to ocean acidification (OA). Coastal and estuarine habitats experience annual pH variability that vastly exceeds the magnitude of long-term projections in open ocean regions. Eastern oyster (Crassostrea virginica) reproduction season coincides with periods of low pH occurrence in estuaries, thus we investigated effects of moderate (pH 7.5, pCO 2 2260 µatm) and severe OA (pH 7.1, pCO 2 5584 µatm; and 6.7, pCO 2 18480 µatm) on oyster gametogenesis, fertilization, and early larval development successes. Exposure at severe OA during gametogenesis caused disruption in oyster reproduction. Oogenesis appeared to be more sensitive compared to spermatogenesis. However, Eastern oyster reproduction was resilient to moderate OA projected for the near-future. In the context of projected climate change exacerbating seasonal acidification, OA of coastal habitats could represent a significant bottleneck for oyster reproduction which may have profound negative implications for coastal ecosystems reliant on this keystone species.

Characterization of highly concentrated antibody solution - A toolbox for the description of protein long-term solution stability

PubMed Central

Schermeyer, Marie-Therese; Wöll, Anna K.; Eppink, Michel; Hubbuch, Jürgen

2017-01-01

ABSTRACT High protein titers are gaining importance in biopharmaceutical industry. A major challenge in the development of highly concentrated mAb solutions is their long-term stability and often incalculable viscosity. The complexity of the molecule itself, as well as the various molecular interactions, make it difficult to describe their solution behavior. To study the formulation stability, long- and short-range interactions and the formation of complex network structures have to be taken into account. For a better understanding of highly concentrated solutions, we combined established and novel analytical tools to characterize the effect of solution properties on the stability of highly concentrated mAb formulations. In this study, monoclonal antibody solutions in a concentration range of 50–200 mg/ml at pH 5–9 with and without glycine, PEG4000, and Na2SO4 were analyzed. To determine the monomer content, analytical size-exclusion chromatography runs were performed. ζ-potential measurements were conducted to analyze the electrophoretic properties in different solutions. The melting and aggregation temperatures were determined with the help of fluorescence and static light scattering measurements. Additionally, rheological measurements were conducted to study the solution viscosity and viscoelastic behavior of the mAb solutions. The so-determined analytical parameters were scored and merged in an analytical toolbox. The resulting scoring was then successfully correlated with long-term storage (40 d of incubation) experiments. Our results indicate that the sensitivity of complex rheological measurements, in combination with the applied techniques, allows reliable statements to be made with respect to the effect of solution properties, such as protein concentration, ionic strength, and pH shift, on the strength of protein-protein interaction and solution colloidal stability. PMID:28617076

Development and validation of a simple and robust method for arsenic speciation in human urine using HPLC/ICP-MS.

PubMed

Sen, Indranil; Zou, Wei; Alvaran, Josephine; Nguyen, Linda; Gajek, Ryszard; She, Jianwen

2015-01-01

In order to better distinguish the different toxic inorganic and organic forms of arsenic (As) exposure in individuals, we have developed and validated a simple and robust analytical method for determining the following six As species in human urine: arsenous (III) acid (As-III), As (V) acid, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine (AsB), and arsenocholine. In this method, human urine is diluted using a pH 5.8 buffer, separation is performed using an anion exchange column with isocratic HPLC, and detection is achieved using inductively coupled plasma-MS. The method uses a single mobile phase consisting of low concentrations of both phosphate buffer (5 mM) and ammonium nitrate salt (5 mM) at pH 9.0; this minimizes the column equilibration time and overcomes challenges with separation between AsB and As-III. In addition, As-III oxidation is prevented by degassing the sample preparation buffer at pH 5.8, degassing the mobile phase online at pH 9.0, and by the use of low temperature (-70 °C) and flip-cap airtight tubes for long term storage of samples. The method was validated using externally provided reference samples. Results were in agreement with target values at varying concentrations and successfully passed external performance test criteria. Internal QC samples were prepared and repeatedly analyzed to assess the method's long-term precision, and further analyses were completed on anonymous donor urine to assess the quality of the method's baseline separation. Results from analyses of external reference samples agreed with target values at varying concentrations, and results from precision studies yielded absolute CV values of 3-14% and recovery from 82 to 115% for the six As species. Analysis of anonymous donor urine confirmed the well-resolved baseline separation capabilities of the method for real participant samples.

Enhancement of Immune Memory Responses to Respiratory Infection

DTIC Science & Technology

2017-08-01

Unlimited Distribution 13. SUPPLEMENTARY NOTES 14. ABSTRACT Maintenance of long - term immunological memory against pathogens is crucial for the rapid...highly expressed in memory B cells in mice, and Atg7 is required for maintenance of long - term memory B cells needed to protect against influenza...AWARD NUMBER: W81XWH-16-1-0360 TITLE: Enhancement of Immune Memory Responses to Respiratory Infection PRINCIPAL INVESTIGATORs: Dr Min Chen PhD

Acid rock drainage passive remediation using alkaline clay and impacts of vegetation and saturated sand barrier

NASA Astrophysics Data System (ADS)

Plaza, F.; Wen, Y.; Liang, X.

2017-12-01

Acid rock drainage (ARD) caused by abundance of coal refuse (CR) deposits in mining regions requires adequate treatment to prevent serious water pollution due to its acidity and high concentrations of sulfate and metals/metalloids. Over the past decades, various approaches have been explored and developed to remediate ARD. This study uses laboratory experiments to investigate the effectiveness and impacts of ARD passive remediation using alkaline clay (AC), a by-product of the aluminum refining process. Twelve column kinetic leaching experiments were set up with CR/AC mixing ratios ranging from 1%AC to 10%AC. Samples were collected from these columns to measure the pH, sulfate, metals/metalloids, acidity and alkalinity. Additional tests of XRD and acid base accounting were also conducted to better characterize the mineral phase in terms of the alkalinity and acidity potential. Based on the leachate measurement results, these columns were further classified into two groups of neutral/near neutral pH and acidic pH for further analysis. In addition, impacts of the vegetation and saturated sand layer on the remediation effectiveness were explored. The results of our long-term (more than three years in some cases) laboratory experiments show that AC is an effective ARD remediation material for the neutralization of leachate pH and immobilization of sulfate and metals such as Fe, Mn, Cu, Zn, Ni, Pb, Cd, Co. The CR/AC mixing ratios higher than 3%AC are found to be effective, with 10% close to optimal. Moreover, the results demonstrate the benefits of using vegetation and a saturated sand barrier. Vegetation acted as a phytoaccumulation/phytoextraction agent, causing an additional immobilization of metals. The saturated sand barrier blocked the oxygen and water diffusion downwards, leading to a reduction of the pyrite oxidation rate. Finally, the proposed remediation approach shows that the acidity consumption will likely occur before all the alkalinity is exhausted, guaranteeing an adequate long-term performance of this remediation approach.

The collaborative African genomics network training program: A trainee perspective on training the next generation of African scientists

USDA-ARS?s Scientific Manuscript database

The Collaborative African Genomics Network (CAfGEN) aims to establish sustainable genomics research programs in Botswana and Uganda through long-term training of PhD students from these countries at Baylor College of Medicine. Here, we present an overview of the CAfGEN PhD training program alongside...

Pulmonary hypertension: Real-world data from a Portuguese expert referral centre.

PubMed

Gomes, A; Cruz, C; Rocha, J; Ricardo, M; Vicente, M; Melo, A; Santos, M; Carvalho, L; Gonçalves, F; Reis, A

2018-04-16

Pulmonary hypertension (PH) is a heterogeneous, debilitating condition with highly relevant impact on functional capacity, quality of life, and life-expectancy. This study aims to provide long-term data on the Portuguese PH population, by characterising the clinical presentation, evolution, and outcomes of PH patients in a specialised referral centre. Retrospective analysis of a cohort of 101 patients with pre-capillary PH (pcPH) referenced to an expert tertiary care referral centre in northern Portugal from 2002 to 2013. Diagnosis was confirmed by right heart catheterisation (RHC). PH classification followed consensus criteria from the 5th World Symposium in Nice, 2013. The most frequent causes of pcPH were Group 1 PH - pulmonary arterial hypertension (PAH) (54.4%) and Group 4 PH - Chronic thromboembolic pulmonary hypertension (CTEPH) (25.7%); importantly, 17.8% of patients presented PH associated with multiple aetiologies. Targeted therapy was used in 91.1% of patients (48.5% combination therapy). 1-, 3-, and 5-year survival was estimated at 86.6%, 76.7%, and 64.1%, respectively. Survival was significantly better for those ≤40 years old (10.5 vs. 6.4 years; P=0.003) and for women with I/HPAH (9.3 vs. 4.5 years; P=0.039). This study provides long-term, real-world data for the management of PAH and CTEPH in Portugal and demonstrates the importance of dedicated electronic medical records and well defined clinical management protocols for better patient outcomes. Patients presented mostly with intermediate or high risk of mortality, which suggests delayed diagnosis and highlights the need to increase awareness among clinicians. Copyright © 2018 Sociedade Portuguesa de Pneumologia. Published by Elsevier España, S.L.U. All rights reserved.

Activation of immunity, immune response, antioxidant ability, and resistance against Vibrio alginolyticus in white shrimp Litopenaeus vannamei decrease under long-term culture at low pH.

PubMed

Chen, Yu-Yuan; Chen, Jiann-Chu; Tseng, Kuei-Chi; Lin, Yong-Chin; Huang, Chien-Lun

2015-10-01

The growth, activation of immunity, immune parameters, and transcript levels of cytMnSOD, mtMnSOD, ecCuZnSOD, glutathione peroxidase (GPx), catalase, lysozyme, and penaeidin 3a were examined in white shrimp Litopenaeus vannamei reared at pH 6.8 and 8.1 after 24 weeks. No significant difference in growth was observed between the two groups. An in vitro study indicated that phenoloxidase activity and respiratory bursts (RB, release of the superoxide anion) were significantly higher in the haemocytes of pH 8.1 shrimp (shrimp reared at pH 8.1) than in pH 6.8 shrimp (shrimp reared at pH 6.8). An in vivo study indicated that the levels of immune parameters of pH 8.1 shrimp were significantly higher than in pH 6.8 shrimp, and the transcript levels of cytMnSOD, ecCuZnSOD, glutathione peroxidase, lysozyme, and penaeidin 3a were down-regulated in pH 6.8 shrimp. In another experiment, shrimp reared at pH 6.8 and 8.1 for 24 weeks were challenged with Vibrio alginolyticus. The mortality rate of pH 6.8 shrimp was significantly higher than in pH 8.1 shrimp over 12-168 h. Phagocytic activity, phagocytic index, and clearance efficiency to V. alginolyticus were significantly lower in pH 6.8 shrimp. We concluded that shrimp under long-term culture at pH 6.8 exhibited decreased resistance against V. alginolyticus as evidenced by reductions in the activation of immunity and immune parameters together with decreased transcript levels of cytMnSOD, ecCuZnSOD, GPx, lysozyme, and penaeidin 3a. Copyright © 2015 Elsevier Ltd. All rights reserved.

Presentation and role of transplantation in adult patients with type 1 primary hyperoxaluria and the I244T AGXT mutation: Single-center experience.

PubMed

Lorenzo, V; Alvarez, A; Torres, A; Torregrosa, V; Hernández, D; Salido, E

2006-09-01

Primary hyperoxaluria type 1 (PH1) is a rare genetic disorder characterized by allelic and clinical heterogeneity. We aim to describe the presentation and full single-center experience of the management of PH1 patients bearing the mutation described in our community (I244T mutation+polymorphism P11L). Since 1983, 12 patients with recurrent renal lithiasis have been diagnosed with PH1 and renal failure in the Canary Islands, Spain. Diagnostic confirmation was based on the presence of oxalosis in undecalcified bone or kidney allograft biopsy, reduced alanine:glyoxylate aminotransferase activity in liver biopsy, and blood DNA analysis. Patients underwent different treatment modalities depending on individual clinical circumstances and therapeutic possibilities at the time of diagnosis: hemodialysis, isolated kidney, simultaneous liver-kidney, or pre-emptive liver transplantation. In all cases, the presentation of advanced renal disease was relatively late (>13 years) and no cases were reported during lactancy or childhood. The eight patients treated with hemodialysis or isolated kidney transplantation showed unfavorable evolution leading to death over a variable period of time. In contrast, the four patients undergoing liver transplantation (three liver+kidney and one pre-emptive liver alone) showed favorable long-term allograft and patient survival (up to 12 years follow-up). In conclusion, in this PH1 population, all bearing the I244T mutation, the development of end-stage renal disease was distinctive during late adolescence or adulthood. Our long-term results support pre-emptive liver transplantation at early stages of renal failure, and kidney-liver transplantation for those with advanced renal disease.

Acidic weathering of basalt and basaltic glass: 1. Near-infrared spectra, thermal infrared spectra, and implications for Mars

NASA Astrophysics Data System (ADS)

Horgan, Briony H. N.; Smith, Rebecca J.; Cloutis, Edward A.; Mann, Paul; Christensen, Philip R.

2017-01-01

Acid-leached rinds and coatings occur in volcanic environments on Earth and have been identified using orbital spectroscopy on Mars, but their development is poorly understood. We simulated long-term open-system acidic weathering in a laboratory by repeatedly rinsing and submerging crystalline and glassy basalts in pH 1 and pH 3 acidic solutions for 213 days and compared their visible/near-infrared (0.3-2.5 µm) and thermal infrared (5-50 µm) spectral characteristics to their microscopic physical and chemical properties from scanning electron microscopy (SEM). We find that while alteration at moderately low pH ( 3) can produce mineral precipitates from solution, it has very little spectral or physical effect on the underlying parent material. In contrast, alteration at very low pH ( 1) results in clear silica spectral signatures for all crystalline samples while glasses exhibit strong blue concave-up near-infrared slopes. SEM indicates that these spectral differences correspond to different modes of alteration. In glass, alteration occurs only at the surface and produces a silica-enriched leached rind, while in more crystalline samples, alteration penetrates the interior to cause dissolution and replacement by silica. We confirm that glass is more stable than crystalline basalt under long-term acidic leaching, suggesting that glass could be enriched and common in terrains on Mars that have been exposed to acidic weathering. Leached glasses are consistent with both OMEGA and Thermal Emission Spectrometer (TES) spectra of the Martian northern lowlands and may contribute to the high-silica phases detected globally in TES Surface Type 2. Thus, both glass-rich deposits and acidic weathering may have been widespread on Mars.

Long-term sustainability of metal immobilization by soil amendments: cyclonic ashes versus lime addition.

PubMed

Ruttens, A; Adriaensen, K; Meers, E; De Vocht, A; Geebelen, W; Carleer, R; Mench, M; Vangronsveld, J

2010-05-01

A soil column leaching experiment was used to gain insight into the long-term metal immobilization capacity of cyclonic ashes (CAH) compared to lime (LIME). Twenty six years of rainfall were simulated. Initially, all amended soils were brought to an equal soil pH. This was done to obtain optimal conditions for the detection of metal immobilization mechanisms different from just a pH effect. During the simulation period, soil pH in all treatments decreased in parallel. However, the evolution of metal mobility and phytoavailability showed a clearly distinct pattern. The strong reduction in metal immobilizing efficiency observed in the lime treatment at the end of the simulation period was much less pronounced, or even absent, in the CAH treatments. Moreover, metal accumulation in plants grown on the CAH amended soil was significantly lower compared to the untreated and the lime treated soil. CAH + SS treatment delivered the strongest reductions in metal mobility and bioavailability. Copyright 2009 Elsevier Ltd. All rights reserved.

Long-term, High Frequency, High Precision pH Measurements on the MBARI deep-water FOCE Experiment at the MARS Cabled Observatory in Monterey Bay, CA

NASA Astrophysics Data System (ADS)

Peltzer, E. T.; Maughan, T.; Barry, J. P.; Brewer, P. G.; Headley, K. L.; Herlien, R.; Kirkwood, W. J.; Matsumoto, G. I.; O'Reilly, T. C.; Salamy, K. A.; Scholfield, J.; Shane, F. F.; Walz, P. M.

2012-12-01

The MBARI deep-water FOCE experiment was deployed on the MARS cabled observatory in Monterey Bay on May 4th, 2011. It has been in continuous operation (excluding a few minor shore based power outages) ever since. During the fifteen months of deployment, we have been able to observe both the daily variation in pH in response to water mass movements associated with the semi-diurnal tides, internal waves and longer-term trends as a function of the seasonal variations in the water masses within the Monterey Bay Canyon. Our experimental site is located at 890 meters, just below the oxygen minimum for Monterey Bay, and we clearly see the anticipated inverse correlation between seawater temperature and pH. Daily variation in pH is on the order of 0.020-0.030 pH units with longer term trends adding an additional variation of similar magnitude. Instrumentation on this experiment included two CTDs with oxygen sensors (Sea-Bird 52). One CTD is mounted on the external FOCE framework to measure the background conditions, and one CTD is installed within the FOCE pH control area to monitor the experimentally manipulated conditions. In addition, 6 MBARI modified Sea-Bird 18 pH sensors were mounted on the FOCE apparatus. Four of these pH sensors monitored pH inside the experimental chamber and two monitored the external background seawater conditions. Although we originally intended to conduct several in situ CO2 enrichment experiments to study the impact of ocean acidification on the benthic biology and then recover the apparatus after one year, unanticipated changes in the ship schedule have left the FOCE experiment in place for nearly fifteen months at the time of this writing. Throughout this time period, all sensor data has been logged by the MBARI Shore-Side Data System (SSDS) resulting in the longest continuous record of high precision pH measurements in the intermediate water column. We present an analysis of the data obtained from this unique data set, and discuss our in-situ calibration techniques used to compensate for long term sensor drift associated with the reference electrode.

An Autonomous Indicator-based pH Sensor for Oceanographic Research and Monitoring

DTIC Science & Technology

2010-01-01

E-mail: michael.degrandpre@umontana.edu Co-PI: Jim Beck , MSME Sunburst Sensors, LLC, 1121 E. Broadway, Suite 114, Missoula, MT 59802 Phone...NOPP Award Number: ONR- BAA -07-040 NSF Award Number: OCE-0836807 LONG-TERM GOALS This project, funded under NOPP Topic 3A Sensors for...Spaulding continued work on establishing long- term stability of mCP. Jim Beck coordinated improvements to the design of the software and hardware

Deep-Sea DuraFET: A Pressure Tolerant pH Sensor Designed for Global Sensor Networks.

PubMed

Johnson, Kenneth S; Jannasch, Hans W; Coletti, Luke J; Elrod, Virginia A; Martz, Todd R; Takeshita, Yuichiro; Carlson, Robert J; Connery, James G

2016-03-15

Increasing atmospheric carbon dioxide is driving a long-term decrease in ocean pH which is superimposed on daily to seasonal variability. These changes impact ecosystem processes, and they serve as a record of ecosystem metabolism. However, the temporal variability in pH is observed at only a few locations in the ocean because a ship is required to support pH observations of sufficient precision and accuracy. This paper describes a pressure tolerant Ion Sensitive Field Effect Transistor pH sensor that is based on the Honeywell Durafet ISFET die. When combined with a AgCl pseudoreference sensor that is immersed directly in seawater, the system is capable of operating for years at a time on platforms that cycle from depths of several km to the surface. The paper also describes the calibration scheme developed to allow calibrated pH measurements to be derived from the activity of HCl reported by the sensor system over the range of ocean pressure and temperature. Deployments on vertical profiling platforms enable self-calibration in deep waters where pH values are stable. Measurements with the sensor indicate that it is capable of reporting pH with an accuracy of 0.01 or better on the total proton scale and a precision over multiyear periods of 0.005. This system enables a global ocean observing system for ocean pH.

MICROBIAL BIOMASS IN SOILS OF RUSSIA UNDER LONG-TERM MANAGEMENT PRACTICES

EPA Science Inventory

Non-tilled and tilled plots on a spodosol (C-org 0.65-1.70%; pH 4.1-4.5) and a mollisol (C-org 3.02-3.13%, pH 4.9-5.3), located in the European region of Russia, were investigated to determine variances in soil microbial biomass and microbial community composition. Continuous, lo...

Long-term impacts of ocean acidification on parent sea urchins and subsequent recruitment

NASA Astrophysics Data System (ADS)

Suckling, C. C.; Clark, M. S.; Peck, L. S.; Harper, E.; Beveridge, C.; Brunner, L.; Hughes, A. D.; Davies, A. J.; Cook, E. J.

2011-12-01

Our oceans have become progressively more acidic over recent decades, yet we still know little about how this will affect marine biota. To survive, organisms must acclimate and adapt. Surprisingly no studies have investigated this beyond focussing on limited parts of the life-cycle and without pre-exposing parents to reduced pH conditions. Using echinoids, we present our findings on the long-term impacts of exposing parents to forecasted reduced pH conditions (IPCC IS92a scenario; ~1000 ppm CO2) and the consequences on their reproductive success through to recruitment. This study will contribute significantly towards our understanding of organismal reactions towards ocean acidification and determine whether they have intergenerational capacities to acclimate and adapt towards conditions well beyond natural-rates of ocean acidification.

The spinodal decomposition in 17-4PH stainless steel subjected to long-term aging at 350 deg. C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Jun; Zou Hong; Li Cong

2008-05-15

The influence of aging time on the microstructure evolution of 17-4 PH martensitic stainless steel was studied by transmission electron microscopy (TEM). Results showed that the martensite decomposed by a spinodal decomposition mechanism after the alloy was subjected to long-term aging at 350 deg. C. The fine scale spinodal decomposition of {alpha}-ferrite brought about a Cr-enriched bright stripe and a Fe-enriched dark stripe, i.e., {alpha}' and {alpha} phases, separately, which were perpendicular to the grain boundary. The spinodal decomposition started at the grain boundary. Then with prolonged aging time, the decomposition microstructure expanded from the grain boundary to interior. Themore » wavelength of the spinodally decomposed microstructure changed little with extended aging time.« less

Gastroesophageal Acid Reflux Control 5 Years After Antireflux Surgery, Compared With Long-term Esomeprazole Therapy.

PubMed

Hatlebakk, Jan G; Zerbib, Frank; Bruley des Varannes, Stanislas; Attwood, Stephen E; Ell, Christian; Fiocca, Roberto; Galmiche, Jean-Paul; Eklund, Stefan; Långström, Göran; Lind, Tore; Lundell, Lars R

2016-05-01

We compared the ability of laparoscopic antireflux surgery (LARS) and esomeprazole to control esophageal acid exposure, over a 5-year period, in patients with chronic gastroesophageal reflux disease (GERD). We also studied whether intraesophageal and intragastric pH parameters off and on therapy were associated with long-term outcomes. We analyzed data from a prospective, randomized, open-label trial comparing the efficacy and safety of LARS vs esomeprazole (20 or 40 mg/d) over 5 years in patients with chronic GERD. Ambulatory intraesophageal and intragastric 24-hour pH monitoring data were compared between groups before LARS or the start of esomeprazole treatment, and 6 months and 5 years afterward. A secondary aim was to evaluate the association between baseline and 6-month pH parameters and esomeprazole dose escalation, reappearance of GERD symptoms, and treatment failure over 5 years in patients receiving LARS or esomeprazole. In the LARS group (n = 116), the median 24-hour esophageal acid exposure was 8.6% at baseline and 0.7% after 6 months and 5 years (P < .001 vs baseline). In the esomeprazole group (n = 151), the median 24-hour esophageal acid exposure was 8.8% at baseline, 2.1% after 6 months, and 1.9% after 5 years (P < .001, therapy vs baseline, and LARS vs esomeprazole). Gastric acidity was stable in both groups. Patients who required a dose increase to 40 mg/d had more severe supine reflux at baseline, and decreased esophageal acid exposure (P < .02) and gastric acidity after dose escalation. Esophageal and intragastric pH parameters, off and on therapy, did not predict long-term symptom breakthrough. In a prospective study of patients with chronic GERD, esophageal acid reflux was reduced greatly by LARS or esomeprazole therapy. However, patients receiving LARS had significantly greater reductions in 24-hour esophageal acid exposure after 6 months and 5 years. Esophageal and gastric pH, off and on therapy, did not predict long-term outcomes of patients. Abnormal supine acid exposure predicted esomeprazole dose escalation. ClinicalTrials.Gov identifier: NCT00251927 (available: http://clinicaltrials.gov/ct2/show/NCT00251927). Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.

Trends in Seawater Boron-based Proxies during the Late Paleocene and Early Eocene Associated with Long-term Warming

NASA Astrophysics Data System (ADS)

Harper, D. T.; Penman, D. E.; Hoenisch, B.; Zachos, J. C.

2014-12-01

Boron isotopes (δ11B) and boron/calcium ratios (B/Ca) in tests of planktic foraminifera are controlled by equilibrium reactions between boron and carbon species in seawater, and thus represent important proxies of past marine carbonate chemistry. Indeed, the recent application of these boron-based proxies to fossil shells of planktic foraminifera from cores spanning the Paleocene-Eocene Thermal Maximum (PETM; 56Ma, an abrupt global warming and ocean acidification event) reveal a decline of ~0.3 in the pH of the mixed-layer [1], an anomaly that is well within the range of estimates based on the observed shoaling of the carbonate compensation depth (CCD) [2, and references therein]. The PETM occurred superimposed on a long-term warming trend that initiated in the Late Paleocene and continued into the Early Eocene (LPEE; 53-59Ma). The magnitude of warming [3] and deepening of the CCD [4] indicate that the LPEE was driven by a rise in pCO2 nearly equivalent to that of the PETM [5]. Here we extend the PETM record of boron-based proxies at IODP Site 1209 across the LPEE, in conjunction with stable carbon and oxygen isotopes in planktic foraminifera, in order to better constrain the long-term changes in pH and carbonate chemistry that accompanied the suggested rise in atmospheric CO2. The 20kyr resolution B/Ca record shows a long-term decline of ~25% during the LPEE, as well as subtle 400kyr cycles associated with eccentricity that mirror those observed in δ13C, and thus might reflect on changes in pH. The lower resolution δ11B record exhibits little change during the Late Paleocene before decreasing step-wise to lower values following the PETM, indicating that either pH in the upper ocean did not change significantly prior to the PETM, despite warming and inferred pCO2 increase, or changes in δ11Bseawater compensated for pH driven changes. As verification of these observations at Site 1209, complementary B/Ca and δ11B records are being generated for Atlantic IODP Sites 1262 and 1263. [1] Penman et al. 2014. Paleoceanography. [2] Palike et al. 2012. Nature. [3] Zachos et al. 2001. Science. [4] Leon-Rodriguez and Dickens 2010. Palaeogeogrphy, Palaeoclimatology, and Palaeoecology. [5] Komar, Zeebe and Dickens 2013. Paleoceanography.

Pulmonary hypertension in patients with chronic obstructive pulmonary disease: advances in pathophysiology and management.

PubMed

Barberà, Joan Albert; Blanco, Isabel

2009-06-18

Pulmonary hypertension (PH) is an important complication in the natural history of chronic obstructive pulmonary disease (COPD). Its presence is associated with reduced survival and greater use of healthcare resources. The prevalence of PH is high in patients with advanced COPD, whereas in milder forms it might not be present at rest but may develop during exercise. In COPD, PH is usually of moderate severity and progresses slowly, without altering right ventricular function in the majority of patients. Nevertheless, a small subgroup of patients (1-3%) may present with out-of-proportion PH, that is, with pulmonary arterial pressure largely exceeding the severity of airway impairment. These patients depict a clinical picture similar to more severe forms of PH and have higher mortality rates. PH in COPD is caused by the remodelling of pulmonary arteries, which is characterized by the intimal proliferation of poorly differentiated smooth muscle cells and the deposition of elastic and collagen fibres. The sequence of changes that lead to PH in COPD begins at early disease stages by the impairment of endothelial function, which is associated with impaired release of endothelium-derived vasodilating agents (nitric oxide, prostacyclin) and increased expression of growth factors. Products contained in cigarette smoke play a critical role in the initiation of pulmonary endothelial cell alterations. Recognition of PH can be difficult because symptoms due to PH are not easy to differentiate from the clinical picture of COPD. Suspicion of PH should be high if clinical deterioration is not matched by the decline in pulmonary function, and in the presence of profound hypoxaemia or markedly reduced carbon monoxide diffusing capacity. Patients with suspected PH should be evaluated by Doppler echocardiography and, if confirmed, undergo right-heart catheterization in those circumstances where the result of the procedure can determine clinical management. To date, long-term oxygen therapy is the treatment of choice in COPD patients with PH and hypoxaemia because it slows or reverses its progression. Conventional vasodilators are not recommended because of their potential detrimental effects on gas exchange, produced by the inhibition of hypoxic pulmonary vasoconstriction and their lack of effectiveness after long-term treatment. In the subgroup of patients with out-of-proportion PH, new specific therapy available for pulmonary arterial hypertension (PAH) [prostanoids, endothelin-1 receptor antagonists and phosphodiesterase-5 inhibitors] may be considered in the setting of clinical trials. The use of specific PAH therapy in COPD patients with moderate PH is discouraged because of the potential detrimental effect of some of these drugs on gas exchange and there are no data demonstrating their efficacy.

Patent ductus arteriosus in an adult cat with pulmonary hypertension and right-sided congestive heart failure: hemodynamic evaluation and clinical outcome following ductal closure.

PubMed

Novo-Matos, José; Hurter, Karin; Bektas, Rima; Grest, Paula; Glaus, Tony

2014-09-01

Right-sided congestive heart failure (CHF) developed secondary to severe pulmonary hypertension (PH) in an 8-year-old cat with a left-to-right shunting patent ductus arteriosus (PDA). Vascular reactivity was tested prior to shunt ligation by treatment with oxygen and sildenafil. This treatment was associated with a significant decrease in pulmonary artery pressure as assessed by echocardiography. Subsequently surgical shunt ligation was planned. During thoracotomy, digital occlusion of the PDA was performed for 10 min with simultaneous catheter measurement of right ventricular pressure, which did not increase. Permanent shunt ligation resulted in a complete and sustained clinical recovery. A lung biopsy sample obtained during thoracotomy demonstrated histopathological arterial changes typical of PH. Cats can develop clinically severe PH and right-sided CHF secondary to a left-to-right PDA even at an advanced age. Assuming there is evidence of pulmonary reactivity, PDA occlusion might be tolerated and can potentially produce long-term clinical benefits. Copyright © 2014 Elsevier B.V. All rights reserved.

The impact of a diphenyl diselenide-supplemented diet and aerobic exercise on memory of middle-aged rats.

PubMed

Cechella, José L; Leite, Marlon R; Gai, Rafaela M; Zeni, Gilson

2014-08-01

Selenium is an essential trace element for human health and has received attention for its role as a nutrient. The combination of exercise and nutrients has been proposed to promote health. The aim of this study was to determine the effects of a diet supplemented with diphenyl diselenide (PhSe)2 and swimming exercise on memory of middle-aged rats. Male Wistar rats (12months) received standard diet chow supplemented with 1ppm of (PhSe)2 for 4weeks. Rats were submitted to swimming training (20min per day for 4weeks). After 4weeks, memory was evaluated in the object recognition test (ORT) and in the object location test (OLT). The hippocampal levels of phosphorylated cAMP-response element-binding protein (CREB) were determined. The results of the present study demonstrated that the association of (PhSe)2-supplemented diet and swimming exercise improved short-term memory, long-term memory and spatial learning, and this effect was not related to the increase in hippocampal p-CREB levels in middle-age rats. This study also revealed that middle-aged rats in the swimming exercise group had the best performance in short- and long-term memory. In conclusion, we demonstrated that swimming exercise, (PhSe)2-supplemented diet or the association of these factors improved learning and memory functioning. The hippocampal levels of CREB were not directly related to the benefits of swimming exercise and (PhSe)2-supplemented diet association in memory of middle-aged rats. Copyright © 2014 Elsevier Inc. All rights reserved.

Spatial competition dynamics between reef corals under ocean acidification.

PubMed

Horwitz, Rael; Hoogenboom, Mia O; Fine, Maoz

2017-01-09

Climate change, including ocean acidification (OA), represents a major threat to coral-reef ecosystems. Although previous experiments have shown that OA can negatively affect the fitness of reef corals, these have not included the long-term effects of competition for space on coral growth rates. Our multispecies year-long study subjected reef-building corals from the Gulf of Aqaba (Red Sea) to competitive interactions under present-day ocean pH (pH 8.1) and predicted end-of-century ocean pH (pH 7.6). Results showed coral growth is significantly impeded by OA under intraspecific competition for five out of six study species. Reduced growth from OA, however, is negligible when growth is already suppressed in the presence of interspecific competition. Using a spatial competition model, our analysis indicates shifts in the competitive hierarchy and a decrease in overall coral cover under lowered pH. Collectively, our case study demonstrates how modified competitive performance under increasing OA will in all likelihood change the composition, structure and functionality of reef coral communities.

Spatial competition dynamics between reef corals under ocean acidification

NASA Astrophysics Data System (ADS)

Horwitz, Rael; Hoogenboom, Mia O.; Fine, Maoz

2017-01-01

Climate change, including ocean acidification (OA), represents a major threat to coral-reef ecosystems. Although previous experiments have shown that OA can negatively affect the fitness of reef corals, these have not included the long-term effects of competition for space on coral growth rates. Our multispecies year-long study subjected reef-building corals from the Gulf of Aqaba (Red Sea) to competitive interactions under present-day ocean pH (pH 8.1) and predicted end-of-century ocean pH (pH 7.6). Results showed coral growth is significantly impeded by OA under intraspecific competition for five out of six study species. Reduced growth from OA, however, is negligible when growth is already suppressed in the presence of interspecific competition. Using a spatial competition model, our analysis indicates shifts in the competitive hierarchy and a decrease in overall coral cover under lowered pH. Collectively, our case study demonstrates how modified competitive performance under increasing OA will in all likelihood change the composition, structure and functionality of reef coral communities.

High-density mammalian cell cultures in stirred-tank bioreactor without external pH control.

PubMed

Xu, Sen; Chen, Hao

2016-08-10

Maintaining desired pH is a necessity for optimal cell growth and protein production. It is typically achieved through a two-sided pH control loop on the bioreactor controller. Here we investigated cell culture processes with minimum or no pH control and demonstrated that high-density mammalian cell cultures could be maintained for long-term protein production without pH control. The intrinsic interactions between pCO2, lactate, and pH were leveraged to maintain culture pH. Fed-batch cultures at the same lower pH limit of 6.75 but different upper pH limits (7.05, 7.30, 7.45, 7.65) were evaluated in the 3L bioreactors and comparable results were obtained. Neither CO2 sparging nor base addition was required to control pH in the pH range of 6.75-7.65. The impact of sparger configurations (drilled hole sparger vs. frit sparger) and scales (3L vs. 200L) on CO2 accumulation and culture pH was also demonstrated. The same principle was applied in two perfusion cultures with steady state cell densities at 42.5±3.3 or 68.3±6.0×10(6)cells/mL with low cell specific perfusion rates (15±2 to 23±3pL/cell/day), achieving up to 1.9±0.1g/L/day bioreactor productivity. Culture pH level in the 3L perfusion bioreactors was steadily maintained by controlling the residual lactate and pCO2 levels without the requirement of external pH control for up to 40days with consistent productivity and product quality. Furthermore, culture pH could be potentially modulated via adjusting residual glucose levels and CO2 stripping capability in perfusion cultures. To the best of our knowledge, this is the first time a systematic study was performed to evaluate the long-term cell cultivation and protein production in stirred-tank bioreactors without external pH control. Copyright © 2016 Elsevier B.V. All rights reserved.

[Stabilization and long-term effect of chromium contaminated soil].

PubMed

Wang, Jing; Luo, Qi-Shi; Zhang, Chang-Bo; Tan, Liang; Li, Xu

2013-10-01

Short-term (3 d and 28 d) and long-term (1 a) stabilization effects of Cr contaminated soil were investigated through nature curing, using four amendments including ferrous sulfide, ferrous sulfate, zero-valent iron and sodium dithionite. The results indicated that ferrous sulfide and zero-valent iron were not helpful for the stabilization of Cr(VI) when directly used because of their poor solubility and immobility. Ferrous sulfate could effectively and rapidly decrease total leaching Cr and Cr(VI) content. The stabilization effect was further promoted by the generation of iron hydroxides after long-term curing. Sodium dithionite also had positive effect on soil stabilization. Appropriate addition ratio of the two chemicals could help maintain the soil pH in range of 6-8.

Efficacy and safety of sildenafil in the treatment of severe pulmonary hypertension in patients with hemoglobinopathies.

PubMed

Derchi, Giorgio; Forni, Gian Luca; Formisano, Francesco; Cappellini, Maria Domenica; Galanello, Renzo; D'Ascola, Giandomenico; Bina, Patrizio; Magnano, Carmelo; Lamagna, Martina

2005-04-01

During the last decade new approaches to the treatment of pulmonary arterial hypertension (PH) have increased symptomatic relief and prolonged survival. PH is a common sequel of the hemoglobinopathies, thalassemia and sickle cell anemia, but the use of standard oral treatment options, such as calcium channel blockers, endothelin receptor antagonists, and long-term anticoagulation therapy, is limited because of toxicity and poor effectiveness. Sildenafil citrate is a selective and potent inhibitor of cGMP-specific phosphodiesterase-5 (PDE5) which promotes selective smooth muscle relaxation in lung vasculature and has been utilized successfully in the treatment of PH. The primary objective of this study was to evaluate the efficacy of sildenafil treatment in the control of PH in patients with hemoglobinopathies. In this study patients with hemoglobinopathies (thalassemia intermedia n=4; thalassemia major n=2; sickle thalassemia n=1) suffering from severe PH were treated with sildenafil citrate (50 mg b.i.d.) for periods ranging from 4 to 48 months. A significant decrease in pulmonary pressure and improvement in exercise capacity and functional class were observed in all patients. No significant adverse events were reported. These data, in a small group of patients, indicate that sildenafil citrate is effective in the treatment of PH in hemoglobinopathies that cannot be treated with alternative oral drugs and is well tolerated long-term at a daily dose of 100 mg, though studies including more patients may uncover toxicities and limitations of efficacy.

Sucrose concentration and pH in liquid oral pediatric medicines of long-term use for children.

PubMed

Passos, Isabela Albuquerque; Sampaio, Fábio Correia; Martínez, Cosme Rafael; Freitas, Cláudia Helena Soares de Morais

2010-02-01

To determine the pH and sucrose concentrations (SC) of pediatric liquid drugs of long-term use by children in order to evaluate the potential risk for dental caries and dental erosion. After assessing the pH, we analyzed 71 aqueous medicine samples for sucrose by the Lane-Eynon general volumetric method. The pH and SC values (mean +/- standard deviation (SD) were calculated according to therapeutic action. The highest and the lowest SC values (mean +/- SD) were found in respiratory (37.75% +/- 17.23%) and endocrine drugs (11.97% +/- 15.16%) (p < 0.01). The values for medicines prescribed for daily ingestion were 47.15% +/- 9.57%, whereas for twice daily and three or four times a day, these numbers were 24.42% +/- 18.03% and 34.43% +/- 14.83%, respectively (p < 0.01). The SC (mean +/- SD)) values were higher in syrups (36.32% +/- 17.62%) than in other formulations (p > 0.05). The overall pH (mean +/- SD) was 5.89 +/- 2.02 (range 2.3 +/- 0.01 to 10.6 +/- 0.02). In products with acidic pH, the SC (mean +/- SD) was significantly lower (22.14% +/- 15.72%) than in nonacidic medicines (39.22% +/- 15.82%) (p < 0.001). It can be concluded that the pediatric medicines studied have a high SC and low pH, which vary according to therapeutic class, daily dose, and brand. Caution about dental caries, dental erosion, and systemic diseases such as diabetes mellitus is warranted when these medicines are ingested frequently.

Sorption of Lincomycin by Manure-Derived Biochars from Water

PubMed Central

Liu, Cheng-Hua; Chuang, Ya-Hui; Li, Hui; Teppen, Brian J.; Boyd, Stephen A.; Gonzalez, Javier M.; Johnston, Cliff T.; Lehmann, Johannes; Zhang, Wei

2018-01-01

The presence of antibiotics in agroecosystems raises concerns about the proliferation of antibiotic-resistant bacteria and adverse effects to human health. Soil amendment with biochars pyrolized from manures may be a win-win strategy for novel manure management and antibiotics abatement. In this study, lincomycin sorption by manure-derived biochars was examined using batch sorption experiments. Lincomycin sorption was characterized by two-stage kinetics with fast sorption reaching quasi-equilibrium in the first 2 d, followed by slow sorption over 180 d. The fast sorption was primarily attributed to surface adsorption, whereas the long-term slow sorption was controlled by slow diffusion of lincomycin into biochar pore structures. Two-day sorption experiments were performed to explore effects of biochar particle size, solid/water ratio, solution pH, and ionic strength. Lincomycin sorption to biochars was greater at solution pH 6.0 to 7.5 below the dissociation constant of lincomycin (7.6) than at pH 9.9 to 10.4 above its dissociation constant. The enhanced lincomycin sorption at lower pH likely resulted from electrostatic attraction between the positively charged lincomycin and the negatively charged biochar surfaces. This was corroborated by the observation that lincomycin sorption decreased with increasing ionic strength at lower pH (6.7) but remained constant at higher pH (10). The long-term lincomycin sequestration by biochars was largely due to pore diffusion plausibly independent of solution pH and ionic composition. Therefore, manure-derived biochars had lasting lincomycin sequestration capacity, implying that biochar soil amendment could significantly affect the distribution, transport, and bioavailability of lincomycin in agroecosystems. PMID:27065399

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, T.P.

Sensors for the determination of pH have been developed which are based on the immobilization of direct dyes at hydrolyzed cellulosic films. The performance and structural characteristics of the sensors were investigated by a variety of spectroscopic methods, and applications for remote sensing were developed. Films of cellulose acetate were base hydrolyzed in 0.07 M KOH to yield a porous support structure. The structural changes resulting from the hydrolysis on cellulose acetate were probed with infrared internal reflectance spectroscopy. The progress of the hydrolysis reaction was monitored by the changes in vibrational modes of the acetyl group, and other spectralmore » changes indicated changes in film thickness as a result of solvent incorporation. Direct dyes, including Congo Red and C. I. Direct Blue 8, were then immobilized at these porous cellulosic films. The optical response characteristics of the Congo Red pH sensor were characterized, including the UV-visible absorption spectra as a function of pH, the response time as a function of ionic strength and ionic size of electrolyte, the long-term stability of the sensor, the effects of metal-ion interference, and the concentration of Congo Red in the polymer film. The structural characteristics of the sensor were investigated by internal reflectance spectroscopy and resonance-enhanced Raman spectroscopy, and the protonation sites were identified as the two azo groups of Congo Red. Infrared internal reflection spectra of immobilized Congo Red led to the development of a sensor for pH based on infrared spectroscopy. Finally, a two-wavelength fiber-optic photometer, which is based on solid-state sources and detectors, and a fiber-optic photometer, which is based on solid-state sources and detectors, and a fiber-optic probe were developed for pH determinations using Congo Red and C. I. Direct Blue 8 pH sensors.« less

Characterization of the pH and Temperature in the Rabbit, Pig, and Monkey Eye: Key Parameters for the Development of Long-Acting Delivery Ocular Strategies.

PubMed

Lorget, Florence; Parenteau, Audrey; Carrier, Michel; Lambert, Daniel; Gueorguieva, Ana; Schuetz, Chris; Bantseev, Vlad; Thackaberry, Evan

2016-09-06

Many long-acting delivery strategies for ocular indications rely on pH- and/or temperature-driven release of the therapeutic agent and degradation of the drug carrier. Yet, these physiological parameters are poorly characterized in ocular animal models. These strategies aim at reducing the frequency of dosing, which is of particular interest for the treatment of chronic disorders affecting the posterior segment of the eye, such as macular degeneration that warrants monthly or every other month intravitreal injections. We used anesthetized white New Zealand rabbits, Yucatan mini pigs, and cynomolgus monkeys to characterize pH and temperature in several vitreous locations and the central aqueous location. We also established post mortem pH changes in the vitreous. Our data showed regional and species differences, which need to be factored into strategies for developing biodegradable long-acting delivery systems.

Acid Mine Drainage Passive Remediation: Potential Use of Alkaline Clay, Optimal Mixing Ratio and Long Term Impacts

NASA Astrophysics Data System (ADS)

Plaza, F.; Liang, X.; Wen, Y.; Perone, H.

2015-12-01

Acid mine drainage (AMD) is one of the most adverse environmental problems of the mine industry. Surface water and ground water affected by this pollution are characterized by their acidity and the high content of sulfates and heavy metals. In this study, alkaline clay, an industrial waste with a high pH, which is utilized in the alumina refining process, was used as the remediation material to inhibit pyrite oxidation. Through a series of batch and column experiments, complemented with field measurements and geochemical modeling, three important issues associated with this passive and auto sustainable acid mine drainage remediation method were investigated: 1) the potential use of alkaline clay as an AMD remediation material, 2) the adequate alkaline clay/coal refuse mixing ratio (AC/CR) to ensure pH values near to neutral conditions, and, 3) the prediction of long term impacts, in terms of the trends of the main parameters involved in this process such as pH, concentrations of sulfate, iron and other dissolved contaminants. Both field measurements and the samples used for the experiments came from a coal waste site located in Mather, Pennsylvania. Alkaline clay proved to be an effective remediation material for AMD. It was found that 10% AC/CR is an adequate mixing ratio (i.e. the upper limit), which has been also indicated by field measurements. The concentrations of some contaminants such as iron, manganese or sulfate are significantly reduced with the remediation approach, compared to those representative concentrations found in mine tailings. Moreover, results suggest a very reliable long-term stability of the remediation (i.e. neutral pH conditions are maintained), thus enhancing the generation of iron precipitates that could produce pyrite grain coating and hardpan (i.e. cemented layer) on the surface. These processes also made the amended layer less porous, thus increasing water retention and hindering oxygen diffusion.

Predicting plant uptake of cadmium: validated with long-term contaminated soils.

PubMed

Lamb, Dane T; Kader, Mohammed; Ming, Hui; Wang, Liang; Abbasi, Sedigheh; Megharaj, Mallavarapu; Naidu, Ravi

2016-10-01

Cadmium accumulates in plant tissues at low soil loadings and is a concern for human health. Yet at higher levels it is also of concern for ecological receptors. We determined Cd partitioning constants for 41 soils to examine the role of soil properties controlling Cd partitioning and plant uptake. From a series of sorption and dose response studies, transfer functions were developed for predicting Cd uptake in Cucumis sativa L. (cucumber). The parameter log K f was predicted with soil pH ca , logCEC and log OC. Transfer of soil pore-water Cd 2+ to shoots was described with a power function (R 2  = 0.73). The dataset was validated with 13 long-term contaminated soils (plus 2 control soils) ranging in Cd concentration from 0.2 to 300 mg kg -1 . The series of equations predicting Cd shoot from pore-water Cd 2+ were able to predict the measured data in the independent dataset (root mean square error = 2.2). The good relationship indicated that Cd uptake to cucumber shoots could be predicted with Cd pore and Cd 2+ without other pore-water parameters such as pH or Ca 2+ . The approach may be adapted to a range of plant species.

Longitudinal meta-analysis of NIST pH Standard Reference Materials(®): a complement to pH key comparisons.

PubMed

Pratt, Kenneth W

2015-04-01

This meta-analysis assesses the long-term (up to 70 years) within-laboratory variation of the NIST pH Standard Reference Material® (SRM) tetroxalate, phthalate, phosphate, borate, and carbonate buffers. Values of ΔpH(S), the difference between the certified pH value, pH(S), of each SRM issue and the mean of all pH(S) values for the given SRM at that Celsius temperature, t, are graphed as a function of the SRM issue and t. In most cases, |ΔpH(S)| < 0.004. Deviations from the nominal base:acid amount (mole) ratio of a buffer yield t-independent, constant shifts in ΔpH(S). The mean ΔpH(S) characterizes such deviations. The corresponding mole fraction of impurity in the conjugate buffer component is generally <0.3 %. Changes in the equipment, personnel, materials, and methodology of the pH(S) measurement yield t-dependent variations. The standard deviation of ΔpH(S) characterizes such changes. Standard deviations of ΔpH(S) are generally 0.0015 or less. The results provide a long-term, single-institution complement to the time-specific, multi-institution results of pH key comparisons administered by the Consultative Committee for Metrology in Chemistry and Biology (CCQM).

Instrument developments for chemical and physical characterization, mapping and sampling of extreme environments (Antarctic sub ice environment)

NASA Astrophysics Data System (ADS)

Vogel, S. W.; Powell, R. D.; Griffith, I.; Lawson, T.; Schiraga, S.; Ludlam, G.; Oen, J.

2009-12-01

A number of instrumentation is currently under development designed to enable the study of subglacial environments in Antarctica through narrow kilometer long boreholes. Instrumentation includes: - slim line Sub-Ice ROV (SIR), - Geochemical Instrumentation Package for Sub Ice Environments (GIPSIE) to study geochemical fluxes in water and across the sediment water interface (CO2, CH4, dO, NH4, NO3, Si, PO4, pH, redox, T, H2, HS, O2, N2O, CTD, particle size, turbidity, color camera, current meter and automated water sampler) with real-time telemetry for targeted sampling, - long term energy-balance mooring system, - active source slide hammer sediment corer, and - integration of a current sensor into the ITP profiler. The instrumentation design is modular and suitable for remote operated as well as autonomous long-term deployment. Of interest to the broader science community is the development of the GIPSIE and efforts to document the effect of sample recovery from depth on the sample chemistry. The GIPSIE is a geochemical instrumentation package with life stream telemetry, allowing for user controlled targeted sampling of water column and the water sediment interphase for chemical and biological work based on actual measurements and not a preprogrammed automated system. The porewater profiler (pH, redox, T, H2, HS, O2, N2O) can penetrate the upper 50 cm of sediment and penetration is documented with real time video. Associated with GIPSIE is an on-site lab set-up, utilizing a set of identical sensors. Comparison between the insitu measurements and measurements taken onsite directly after samples are recovered from depth permits assessing the effect of sample recovery on water and sediment core chemistry. Sample recovery related changes are mainly caused by changes in the pressure temperature field and exposure of samples to atmospheric conditions. Exposure of anaerobic samples to oxygen is here a specific concern. Recovery from depth effects in generally pH, solubility of gases and nutrients and can initiate complex chemical reaction, the product of which is later measured in the lab. Further information on the instrument developments can be found at http://jove.geol.niu.edu/faculty/svogel/Technology/Technology-index.html

Pulmonary hypertension in chronic obstructive pulmonary disease.

PubMed

Weitzenblum, Emmanuel; Chaouat, Ari; Kessler, Romain

2013-01-01

Pulmonary hypertension (PH) is a common complication of advanced chronic obstructive pulmonary disease (COPD) and is defined by a mean pulmonary artery pressure (PAP) ≥ 25 mm Hg at rest in the supine position. Owing to its frequency, COPD is a common cause of PH; in fact, it is the second most frequent cause of PH, just after left heart diseases. PH is due to the elevation of pulmonary vascular resistance, which is caused by functional and morphological factors, chronic alveolar hypoxia being the most important. In COPD PH is generally mild to moderate, PAP usually ranging between 25 and 35 mm Hg in a stable state of the disease. A small proportion of COPD patients may present a severe or "disproportionate" PH with a resting PAP > 35-40 mm Hg. The prognosis is particularly poor in these patients. In COPD PH worsens during exercise, sleep and severe exacerbations of the disease, and these acute increases in afterload may favour the development of right heart failure. The diagnosis of PH relies on Doppler echocardiography, and right heart catheterization is needed in a minority of patients. Treatment of PH in COPD relies on long-term oxygen therapy (≥ 16h/day) which generally stabilizes or at least attenuates the progression of PH. Vasodilator drugs, which are commonly used in idiopathic pulmonary arterial hypertension, have rarely been used in COPD, and we lack studies in this field. Patients with severe PH should be referred to a specialist PH centre where the possibility of inclusion in a controlled clinical trial should be considered.

Biophysical characterization and conformational stability of Ebola and Marburg virus-like particles.

PubMed

Hu, Lei; Trefethen, Jared M; Zeng, Yuhong; Yee, Luisa; Ohtake, Satoshi; Lechuga-Ballesteros, David; Warfield, Kelly L; Aman, M Javad; Shulenin, Sergey; Unfer, Robert; Enterlein, Sven G; Truong-Le, Vu; Volkin, David B; Joshi, Sangeeta B; Middaugh, C Russell

2011-12-01

The filoviruses, Ebola virus and Marburg virus, cause severe hemorrhagic fever with up to 90% human mortality. Virus-like particles of EBOV (eVLPs) and MARV (mVLPs) are attractive vaccine candidates. For the development of stable vaccines, the conformational stability of these two enveloped VLPs produced in insect cells was characterized by various spectroscopic techniques over a wide pH and temperature range. Temperature-induced aggregation of the VLPs at various pH values was monitored by light scattering. Temperature/pH empirical phase diagrams (EPDs) of the two VLPs were constructed to summarize the large volume of data generated. The EPDs show that both VLPs lose their conformational integrity above about 50°C-60°C, depending on solution pH. The VLPs were maximally thermal stable in solution at pH 7-8, with a significant reduction in stability at pH 5 and 6. They were much less stable in solution at pH 3-4 due to increased susceptibility of the VLPs to aggregation. The characterization data and conformational stability profiles from these studies provide a basis for selection of optimized solution conditions for further vaccine formulation and long-term stability studies of eVLPs and mVLPs. Copyright © 2011 Wiley-Liss, Inc.

Long-term wireless pH monitoring of the distal esophagus: prolonging the test beyond 48 hours is unnecessary and may be misleading.

PubMed

Capovilla, G; Salvador, R; Spadotto, L; Voltarel, G; Pesenti, E; Perazzolo, A; Nicoletti, L; Merigliano, S; Costantini, M

2017-10-01

Wireless pH monitoring of the esophagus has been widely used to detect GERD for more than a decade. It is generally well tolerated and accepted by patients, but it is still unclear whether prolonging a recording beyond the usual 48 hours can improve the test's diagnostic value. The aim of this study is to examine the diagnostic yield of 96-hour pH monitoring vis-à-vis 24- and 48-hour tests, and to ascertain whether any gain in diagnostic terms was of genuine clinical utility. Patients with suspected GERD underwent 4-day PPI-off wireless pH monitoring of the distal esophagus. The capsule was inserted under endoscopic control, 6 cm above the squamocolumnar junction. Average acid exposure time was calculated after 24, 48, and 96 hours of recording. Ninety-nine patients completed the 96 hour test, and formed the study sample. The wireless test method was used in 42 patients (42.4%) unable to tolerate the traditional pH-monitoring catheter, and in 57 (57.6%) with a previous negative pH study despite symptoms suggestive of GERD. On complete analysis, 47 patients (47.5%) had a pathological test result: 19 patients within the first 24 hours (19.2%, 24 hour group); another 16 after 48 hours (+16.2%, 48 hour group), and a further 12 (+12.1%, 96 hour group) only after 96 hours of monitoring. All 47 patients with an abnormal acid exposure were offered and accepted surgery (10 patients) or medical therapy (37 patients). Clinical follow-up was obtained in all patients with a positive Bravo test result after a median 67 months (IQR: 38-98) using a validated symptom questionnaire. A good outcome after fundoplication or medical therapy was achieved in 73.7% of patients in the 24 hour group, in 62.5% of those in the 48 hour group, and in only 25% of those in the 96 hour group, P = 0.02. Long-term wireless pH monitoring enables an increase in the diagnostic yield over traditional 24- and 48-hour pH studies, but prolonging the test may constitute an unwanted bias and prompt the recruitment of more complex patients, in whom the outcome of surgical or medical therapy may prove less than satisfactory. These findings should be taken into account when establishing the guidelines for assessing GERD with such long-term pH monitoring methods. © The Authors 2017. Published by Oxford University Press on behalf of International Society for Diseases of the Esophagus. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Bioengineering vascularized tissue constructs using an injectable cell-laden enzymatically crosslinked collagen hydrogel derived from dermal extracellular matrix.

PubMed

Kuo, Kuan-Chih; Lin, Ruei-Zeng; Tien, Han-Wen; Wu, Pei-Yun; Li, Yen-Cheng; Melero-Martin, Juan M; Chen, Ying-Chieh

2015-11-01

Tissue engineering promises to restore or replace diseased or damaged tissue by creating functional and transplantable artificial tissues. The development of artificial tissues with large dimensions that exceed the diffusion limitation will require nutrients and oxygen to be delivered via perfusion instead of diffusion alone over a short time period. One approach to perfusion is to vascularize engineered tissues, creating a de novo three-dimensional (3D) microvascular network within the tissue construct. This significantly shortens the time of in vivo anastomosis, perfusion and graft integration with the host. In this study, we aimed to develop injectable allogeneic collagen-phenolic hydroxyl (collagen-Ph) hydrogels that are capable of controlling a wide range of physicochemical properties, including stiffness, water absorption and degradability. We tested whether collagen-Ph hydrogels could support the formation of vascularized engineered tissue graft by human blood-derived endothelial colony-forming cells (ECFCs) and bone marrow-derived mesenchymal stem cells (MSC) in vivo. First, we studied the growth of adherent ECFCs and MSCs on or in the hydrogels. To examine the potential formation of functional vascular networks in vivo, a liquid pre-polymer solution of collagen-Ph containing human ECFCs and MSCs, horseradish peroxidase and hydrogen peroxide was injected into the subcutaneous space or abdominal muscle defect of an immunodeficient mouse before gelation, to form a 3D cell-laden polymerized construct. These results showed that extensive human ECFC-lined vascular networks can be generated within 7 days, the engineered vascular density inside collagen-Ph hydrogel constructs can be manipulated through refinable mechanical properties and proteolytic degradability, and these networks can form functional anastomoses with the existing vasculature to further support the survival of host muscle tissues. Finally, optimized conditions of the cell-laden collagen-Ph hydrogel resulted in not only improving the long-term differentiation of transplanted MSCs into mineralized osteoblasts, but the collagen-Ph hydrogel also improved an increased of adipocytes within the vascularized bioengineered tissue in a mouse after 1 month of implantation. We reported a method for preparing autologous extracellular matrix scaffolds, murine collagen-Ph hydrogels, and demonstrated its suitability for use in supporting human progenitor cell-based formation of 3D vascular networks in vitro and in vivo. Results showed extensive human vascular networks can be generated within 7 days, engineered vascular density inside collagen-Ph constructs can be manipulated through refinable mechanical properties and proteolytic degradability, and these networks can form functional anastomoses with existing vasculature to further support the survival of host muscle tissues. Moreover, optimized conditions of cell-laden collagen-Ph hydrogel resulted in not only improving the long-term differentiation of transplanted MSCs into mineralized osteoblasts, but the collagen-Ph hydrogel also improved an increased of adipocytes within the vascularized bioengineered tissue in a mouse. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Effects of experimental long-term CO2 exposure on Daphnia magna (Straus 1820): From physiological effects to ecological consequences.

PubMed

Parra, Gema; Galotti, Andréa; Jiménez-Melero, Raquel; Guerrero, Francisco; Sánchez-Moyano, Emilio; Jiménez-Gómez, Francisco; Conradi, Mercedes

2016-08-01

The carbon capture and storage (CCS) technologies that were proposed to mitigate environmental problems arising from anthropogenic CO2 emissions, also have potential environmental risks. An eventual CCS leak might induce very low pH values in the aquatic system. Due to the lack of knowledge of long-term CO2 exposures with very low pH values, this study aims to know the effects and consequences of such a situation for zooplankton, using the Daphnia magna experimental model. A CO2 injection system was used to provide the experimental condition. A twenty-one days experiment with control and low pH treatment (pH = 7) replicates was carried out under light and temperature-controlled conditions. Survival, individual growth, RNA:DNA ratio, and neonates production were analysed during the aforementioned period. No differences on survival (except last day), individual growth and RNA:DNA ratio were observed between both control and low pH treatments. However, clear differences were detected in neonates production and, consequently, in population growth rates and secondary production. The observed differences could be related with an energy allocation strategy to ensure individual survival but would have ecological consequences affecting higher trophic levels. Copyright © 2016 Elsevier Ltd. All rights reserved.

One-year stability for a glucose/oxygen biofuel cell combined with pH reactivation of the laccase/carbon nanotube biocathode.

PubMed

Reuillard, Bertrand; Abreu, Caroline; Lalaoui, Noémie; Le Goff, Alan; Holzinger, Michael; Ondel, Olivier; Buret, Francois; Cosnier, Serge

2015-12-01

This study reports a mixed operational/storage stability of a MWCNT-based glucose biofuel cell (GBFC) over one year. The latter was examined by performing a one hour discharge every day during one month followed by several discharges over a period of 11 months. Under continuous discharge in physiological conditions (5 mM glucose, 37°, pH7), the GBFC exhibits a 25% power decrease after 1 h of operation. This decrease is mainly due to the deactivation of laccase biocathodes at neutral pH. Nevertheless, the biocathodes can be reversibly reactivated via storage in phosphate buffer (pH 5). Under these conditions, the GBFC finally exhibits 22% of its initial maximum power density after one year at intermittent reactivation/discharge cycles. Although both GBFC electrodes can exhibit one year stability, short-term experiments show that biocathodes are limited by hydroxide inhibition while long-term experiments indicate that bioanodes are likely limited by the stability of the GOx itself. While most of the GBFCs in the literature present stability in the range of several weeks, these results demonstrate the viability of a GBFC for industrial applications in a long period of time. Copyright © 2015 Elsevier B.V. All rights reserved.

Integrated approach to modeling long-term durability of concrete engineered barriers in LLRW disposal facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, J.H.; Roy, D.M.; Mann, B.

1995-12-31

This paper describes an integrated approach to developing a predictive computer model for long-term performance of concrete engineered barriers utilized in LLRW and ILRW disposal facilities. The model development concept consists of three major modeling schemes: hydration modeling of the binder phase, pore solution speciation, and transport modeling in the concrete barrier and service environment. Although still in its inception, the model development approach demonstrated that the chemical and physical properties of complex cementitious materials and their interactions with service environments can be described quantitatively. Applying the integrated model development approach to modeling alkali (Na and K) leaching from amore » concrete pad barrier in an above-grade tumulus disposal unit, it is predicted that, in a near-surface land disposal facility where water infiltration through the facility is normally minimal, the alkalis control the pore solution pH of the concrete barriers for much longer than most previous concrete barrier degradation studies assumed. The results also imply that a highly alkaline condition created by the alkali leaching will result in alteration of the soil mineralogy in the vicinity of the disposal facility.« less

Coping with PH over the Long Term

MedlinePlus

... review Conflict of Interest Disclosures for PHA’s medical leadership, visit: Disclosures Last reviewed: April 2012 Support About ... Rare Disorders (NORD) awarded PHA the Abbey S. Meyers Leadership Award in 2012 for outstanding service to PHA ...

Long-term nitrogen fertilization decreases bacterial diversity and favors the growth of Actinobacteria and Proteobacteria in agro-ecosystems across the globe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai, Zhongmin; Su, Weiqin; Chen, Huaihai

Long-term Elevated nitrogen (N) input from anthropogenic sources may cause soil acidification and decrease crop yield, yet the response of the belowground microbial community to long-term N input and the input of N combined with phosphorus (P) and potassium (K) is still poorly understood. Here, we explored the effect of long-term N and NPK fertilization on soil bacterial diversity and community composition using meta-analysis of a global dataset. Nitrogen fertilization decreased soil pH, and increased soil organic carbon (C) and available N contents. Bacterial taxonomic diversity was decreased by N fertilization alone, but was increased by NPK fertilization. The effectmore » of N fertilization on bacterial diversity depends on soil texture and water management, but independent of crop type or N application rate. Both soil pH and organic C content were positively related to changes in bacterial diversity under N fertilization, while soil organic C was the dominant factor determining changes in bacterial diversity under NPK fertilization. Microbial biomass C decreased with decreasing bacterial diversity under long-term N fertilization. Nitrogen fertilization increased the relative abundance of copiotrophic bacteria (i.e. Proteobacteria and Actinobacteria), but reduced the abundance of oligotrophic taxa (i.e. Acidobacteria), consistent with the general life history strategy theory for bacteria. The relative abundance of Proteobacteria was also increased by NPK fertilization. The positive correlation between N application rate and the relative abundance of Actinobacteria indicates that increased N availability favored the growth of Actinobacteria. This first global analysis of long-term N and NPK fertilization effect on bacterial diversity and community composition suggests that N input decreases bacterial diversity but favors the growth of copiotrophic bacteria, providing a reference for nutrient management strategies for maintaining belowground microbial diversity in agro-ecosystems worldwide.« less

Long-term nitrogen fertilization decreases bacterial diversity and favors the growth of Actinobacteria and Proteobacteria in agro-ecosystems across the globe

DOE PAGES

Dai, Zhongmin; Su, Weiqin; Chen, Huaihai; ...

2018-04-25

Long-term Elevated nitrogen (N) input from anthropogenic sources may cause soil acidification and decrease crop yield, yet the response of the belowground microbial community to long-term N input and the input of N combined with phosphorus (P) and potassium (K) is still poorly understood. Here, we explored the effect of long-term N and NPK fertilization on soil bacterial diversity and community composition using meta-analysis of a global dataset. Nitrogen fertilization decreased soil pH, and increased soil organic carbon (C) and available N contents. Bacterial taxonomic diversity was decreased by N fertilization alone, but was increased by NPK fertilization. The effectmore » of N fertilization on bacterial diversity depends on soil texture and water management, but independent of crop type or N application rate. Both soil pH and organic C content were positively related to changes in bacterial diversity under N fertilization, while soil organic C was the dominant factor determining changes in bacterial diversity under NPK fertilization. Microbial biomass C decreased with decreasing bacterial diversity under long-term N fertilization. Nitrogen fertilization increased the relative abundance of copiotrophic bacteria (i.e. Proteobacteria and Actinobacteria), but reduced the abundance of oligotrophic taxa (i.e. Acidobacteria), consistent with the general life history strategy theory for bacteria. The relative abundance of Proteobacteria was also increased by NPK fertilization. The positive correlation between N application rate and the relative abundance of Actinobacteria indicates that increased N availability favored the growth of Actinobacteria. This first global analysis of long-term N and NPK fertilization effect on bacterial diversity and community composition suggests that N input decreases bacterial diversity but favors the growth of copiotrophic bacteria, providing a reference for nutrient management strategies for maintaining belowground microbial diversity in agro-ecosystems worldwide.« less

Long-term mortality rates (>8-year) improve as compared to the general and obese population following bariatric surgery.

PubMed

Telem, Dana A; Talamini, Mark; Shroyer, A Laurie; Yang, Jie; Altieri, Maria; Zhang, Qiao; Gracia, Gerald; Pryor, Aurora D

2015-03-01

Sparse data are available on long-term patient mortality following bariatric surgery as compared to the general population. The purpose of this study was to assess long-term mortality rates and identify risk factors for all-cause mortality following bariatric surgery. New York State (NYS) Planning and Research Cooperative System (SPARCS) longitudinal administrative data were used to identify 7,862 adult patients who underwent a primary laparoscopic bariatric surgery from 1999 to 2005. The Social Security Death Index database identified >30-day mortalities. Risk factors for mortality were screened using a univariate Cox proportional hazard (PH) model and analyzed using a multiple PH model. Based on age, gender, and race/ethnicity, actuarial projections for NYS mortality rates obtained from Centers of Disease Control were compared to the actual post-bariatric surgery mortality rates observed. The mean bariatric mortality rate was 2.5 % with 8-14 years of follow-up. Mean time to death ranged from 4 to 6 year and did not differ by operation (p = 0.073). From 1999 to 2010, the actuarial mortality rate predicted for the general NYS population was 2.1 % versus the observed 1.5 % for the bariatric surgery population (p = 0.005). Extrapolating to 2013, demonstrated the actuarial mortality predictions at 3.1 % versus the bariatric surgery patients' observed morality rate of 2.5 % (p = 0.01). Risk factors associated with an earlier time to death included: age, male gender, Medicare/Medicaid insurance, congestive heart failure, rheumatoid arthritis, pulmonary circulation disorders, and diabetes. No procedure-specific or perioperative complication impact for time-to-death was found. Long-term mortality rate of patients undergoing bariatric surgery significantly improves as compared to the general population regardless of bariatric operation performed. Additionally, perioperative complications do not increase long-term mortality risk. This study did identify specific patient risk factors for long-term mortality. Special attention and consideration should be given to these "at risk" patient sub-populations.

Training Patterns and Lifetime Career Achievements of US Academic Cardiothoracic Surgeons.

PubMed

Rosati, Carlo Maria; Valsangkar, Nakul P; Gaudino, Mario; Blitzer, David; Vardas, Panos N; Girardi, Leonard N; Turrentine, Mark W; Brown, John W; Koniaris, Leonidas G

2017-03-01

We aimed to investigate the impact of taking dedicated time for research (DTR) during training and/or getting a PhD on subsequent career achievements of US academic cardiothoracic surgeons. Online resources (institutional Web sites, CTSNet, Scopus, NIH RePORTER) were queried to collect training information (timing of medical school/residency/fellowship graduation, DTR, PhD) and academic metrics (publications, citations, research funding) for 694 academic cardiothoracic surgeons practicing at 56 premiere US institutions. Excluding missing data, 464 (75 %) surgeons took DTR and 156 (25 %) did not; 629 (91 %) were MD only and 65 (9 %) also had a PhD. DTR was associated with higher number of ongoing publications (~5.6/year vs. ~3.8/year), with no difference for accrued number of total citations. History of DTR was more prevalent among surgeons with versus without NIH funding (87 vs. 71 %; p < 0.001), but no difference was seen across academic ranks and among those who were division/department chiefs. No overall increase in publications/citations, academic rank advancement, NIH funding, or leadership roles was found for those with a PhD. Among cardiothoracic surgeons, devoting time during the training years exclusively to research might be associated with higher career-long academic productivity in terms of annual number new publications and ability to get NIH funding, but without significant impact in terms of academic rank or institutional role advancement. No significant difference was found between those with versus without a PhD in terms of career-long number of publications/citations, academic rank, NIH funding, or leadership role, even though sample size might have been insufficient to identify any such potential difference.

Phosphate reactivity in long-term poultry litter-amended southern Delaware sandy soils

USGS Publications Warehouse

Arai, Y.; Livi, K.J.T.; Sparks, D.L.

2005-01-01

Eutrophication caused by dissolved P from poultry litter (PL)-amended agricultural soils has been a serious environmental concern in the Delaware-Maryland-Virginia Peninsula (Delmarva), USA. To evaluate state and federal nutrient management strategies for reducing the environmental impact of soluble P from long-term PL-amended Delaware (DE) soils, we investigated (i) inorganic P speciation; (ii) P adsorption capacity; and (iii) the extent of P desorption. Although the electron microprobe (EMP) analyses showed a strong correlation between P and Al/Fe, crystalline Al/Fe-P precipitates were not detected by x-ray diffraction (XRD). Instead, the inorganic P fractionation analyses showed high levels of oxalate extractable P, Al, and Fe fractions (615-858, 1215-1478, and 337-752 mg kg-1, respectively), which were susceptible to slow release during the long-term (30-d) P desorption experiments at a moderately acidic soil pHwater. The labile P in the short-term (24-h) desorption studies was significantly associated with oxalate and F extractable Fe and Al, respectively. This was evident in an 80% reduction maximum in total desorbable P from NH4 oxalate/F pretreated soils. In the adsorption experiments, P was strongly retained in soils at near targeted pH of lime (???6.0), but P adsorption gradually decreased with decreasing pH near the soil pHwater (???5.0). The overall findings suggest that P losses from the can be suppressed by an increase in the P retention capacity of soils via (i) an increase in the number of lime applications to maintain soil pHwater at near targeted pH values, and/or (ii) alum/iron sulfate amendments to provide additional Al- and Fe-based adsorbents. ?? Soil Science Society of America.

Polyaniline deposition on tilted fiber Bragg grating for pH sensing

NASA Astrophysics Data System (ADS)

Lopez Aldaba, A.; González-Vila, Á.; Debliquy, M.; Lopez-Amo, M.; Caucheteur, C.; Lahem, D.

2017-04-01

In this paper, we present the results of a new pH sensor based on a polyaniline (PAni) coating on the surface of a tilted fiber Bragg grating. The pH-sensitive PAni was deposited by in situ chemical oxidative polymerization. The performance of the fabricated pH sensor was tested and the obtained pH values were compared with the results obtained using a pH meter device. It was found that the sensor exhibits response to pH changes in the range of 2-12, achieving a sensitivity of 46 pm/pH with a maximum error due to the hysteresis effect of +/-1.14 pH. The main advantages of this PAni-TFBG pH sensor are biochemical compatibility, temperature independence, long-term stability and remote realtime multipoint sensing features. This type of sensor could be used for biochemical applications, pipeline corrosion monitoring or remote-multipoint measurements.

Seagrass ecosystem response to long-term high CO2 in a Mediterranean volcanic vent.

PubMed

Apostolaki, Eugenia T; Vizzini, Salvatrice; Hendriks, Iris E; Olsen, Ylva S

2014-08-01

We examined the long-term effect of naturally acidified water on a Cymodocea nodosa meadow growing at a shallow volcanic CO2 vent in Vulcano Island (Italy). Seagrass and adjacent unvegetated habitats growing at a low pH station (pH = 7.65 ± 0.02) were compared with corresponding habitats at a control station (pH = 8.01 ± 0.01). Density and biomass showed a clear decreasing trend at the low pH station and the below- to above-ground biomass ratio was more than 10 times lower compared to the control. C content and δ(13)C of leaves and epiphytes were significantly lower at the low pH station. Photosynthetic activity of C. nodosa was stimulated by low pH as seen by the significant increase in Chla content of leaves, maximum electron transport rate and compensation irradiance. Seagrass community metabolism was intense at the low pH station, with significantly higher net community production, respiration and gross primary production than the control community, whereas metabolism of the unvegetated community did not differ between stations. Productivity was promoted by the low pH, but this was not translated into biomass, probably due to nutrient limitation, grazing or poor environmental conditions. The results indicate that seagrass response in naturally acidified conditions is dependable upon species and geochemical characteristics of the site and highlight the need for a better understanding of complex interactions in these environments. Copyright © 2014 Elsevier Ltd. All rights reserved.

Identification of long-term trends and seasonality in high-frequency water quality data from the Yangtze River basin, China.

PubMed

Duan, Weili; He, Bin; Chen, Yaning; Zou, Shan; Wang, Yi; Nover, Daniel; Chen, Wen; Yang, Guishan

2018-01-01

Comprehensive understanding of the long-term trends and seasonality of water quality is important for controlling water pollution. This study focuses on spatio-temporal distributions, long-term trends, and seasonality of water quality in the Yangtze River basin using a combination of the seasonal Mann-Kendall test and time-series decomposition. The used weekly water quality data were from 17 environmental stations for the period January 2004 to December 2015. Results show gradual improvement in water quality during this period in the Yangtze River basin and greater improvement in the Uppermost Yangtze River basin. The larger cities, with high GDP and population density, experienced relatively higher pollution levels due to discharge of industrial and household wastewater. There are higher pollution levels in Xiang and Gan River basins, as indicated by higher NH4-N and CODMn concentrations measured at the stations within these basins. Significant trends in water quality were identified for the 2004-2015 period. Operations of the three Gorges Reservoir (TGR) enhanced pH fluctuations and possibly attenuated CODMn, and NH4-N transportation. Finally, seasonal cycles of varying strength were detected for time-series of pollutants in river discharge. Seasonal patterns in pH indicate that maxima appear in winter, and minima in summer, with the opposite true for CODMn. Accurate understanding of long-term trends and seasonality are necessary goals of water quality monitoring system efforts and the analysis methods described here provide essential information for effectively controlling water pollution.

Spatial competition dynamics between reef corals under ocean acidification

PubMed Central

Horwitz, Rael; Hoogenboom, Mia O.; Fine, Maoz

2017-01-01

Climate change, including ocean acidification (OA), represents a major threat to coral-reef ecosystems. Although previous experiments have shown that OA can negatively affect the fitness of reef corals, these have not included the long-term effects of competition for space on coral growth rates. Our multispecies year-long study subjected reef-building corals from the Gulf of Aqaba (Red Sea) to competitive interactions under present-day ocean pH (pH 8.1) and predicted end-of-century ocean pH (pH 7.6). Results showed coral growth is significantly impeded by OA under intraspecific competition for five out of six study species. Reduced growth from OA, however, is negligible when growth is already suppressed in the presence of interspecific competition. Using a spatial competition model, our analysis indicates shifts in the competitive hierarchy and a decrease in overall coral cover under lowered pH. Collectively, our case study demonstrates how modified competitive performance under increasing OA will in all likelihood change the composition, structure and functionality of reef coral communities. PMID:28067281

Identifying key controls on the behavior of an acidic-U(VI) plume in the Savannah River Site using reactive transport modeling.

PubMed

Bea, Sergio A; Wainwright, Haruko; Spycher, Nicolas; Faybishenko, Boris; Hubbard, Susan S; Denham, Miles E

2013-08-01

Acidic low-level waste radioactive waste solutions were discharged to three unlined seepage basins at the F-Area of the Department of Energy (DOE) Savannah River Site (SRS), South Carolina, USA, from 1955 through 1989. Despite many years of active remediation, the groundwater remains acidic and contaminated with significant levels of U(VI) and other radionuclides. Monitored Natural Attenuation (MNA) is a desired closure strategy for the site, based on the premise that regional flow of clean background groundwater will eventually neutralize the groundwater acidity, immobilizing U(VI) through adsorption. An in situ treatment system is currently in place to accelerate this in the downgradient portion of the plume and similar measures could be taken upgradient if necessary. Understanding the long-term pH and U(VI) adsorption behavior at the site is critical to assess feasibility of MNA along with the in-situ remediation treatments. This paper presents a reactive transport (RT) model and uncertainty quantification (UQ) analyses to explore key controls on the U(VI)-plume evolution and long-term mobility at this site. Two-dimensional numerical RT simulations are run including the saturated and unsaturated (vadose) zones, U(VI) and H(+) adsorption (surface complexation) onto sediments, dissolution and precipitation of Al and Fe minerals, and key hydrodynamic processes are considered. UQ techniques are applied using a new open-source tool that is part of the developing ASCEM reactive transport modeling and analysis framework to: (1) identify the complex physical and geochemical processes that control the U(VI) plume migration in the pH range where the plume is highly mobile, (2) evaluate those physical and geochemical parameters that are most controlling, and (3) predict the future plume evolution constrained by historical, chemical and hydrological data. The RT simulation results show a good agreement with the observed historical pH and concentrations of U(VI), nitrates and Al concentrations at multiple locations. Mineral dissolution and precipitation combined with adsorption reactions on goethite and kaolinite (the main minerals present with quartz) could buffer pH at the site for long periods of time. UQ analysis using the Morris one-at-a-time (OAT) method indicates that the model/parameter is most sensitive to the pH of the waste solution, discharge rates, and the reactive surface area available for adsorption. However, as a key finding, UQ analysis also indicates that this model (and parameters) sensitivity evolves in space and time, and its understanding could be crucial to assess the temporal efficiency of a remediation strategy in contaminated sites. Results also indicate that residual U(VI) and H(+) adsorbed in the vadose zone, as well as aquifer permeability, could have a significant impact on the acidic plume long-term mobility. Copyright © 2013 Elsevier B.V. All rights reserved.

Long-term leaching of photovoltaic modules

NASA Astrophysics Data System (ADS)

Nover, Jessica; Zapf-Gottwick, Renate; Feifel, Carolin; Koch, Michael; Metzger, Jörg W.; Werner, Jürgen H.

2017-08-01

Some photovoltaic module technologies use toxic materials. We report long-term leaching on photovoltaic module pieces of 5 × 5 cm2 size. The pieces are cut out from modules of the four major commercial photovoltaic technologies: crystalline and amorphous silicon, cadmium telluride as well as from copper indium gallium diselenide. To simulate different environmental conditions, leaching occurs at room temperature in three different water-based solutions with pH 3, 7, and 11. No agitation is performed to simulate more representative field conditions. After 360 days, about 1.4% of lead from crystalline silicon module pieces and 62% of cadmium from cadmium telluride module pieces are leached out in acidic solutions. The leaching depends heavily on the pH and the redox potential of the aqueous solutions and it increases with time. The leaching behavior is predictable by thermodynamic stability considerations. These predictions are in good agreement with the experimental results.

Assessment of the long-term durability of concrete in radioactive waste repositories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Atkinson, A.; Goult, D.J.; Hearne, J.A.

1986-01-01

A preliminary assessment of the long-term durability of concrete in a repository sited in clay is presented. The assessment is based on recorded experience of concrete structures and both field and laboratory studies. It is also supported by results of the examination of a concrete sample which had been buried in clay for 43 years. The engineering lifetime of a 1 m thick reinforced concrete slab, with one face in contact with clay, and the way in which pH in the repository as a whole is likely to vary with time have both been estimated from available data. The estimatesmore » indicate that engineering lifetimes of about 10/sup 3/ years are expected (providing that sulfate resisting cement is used) and that pH is likely to remain above 10.5 for about 10/sup 6/ years.« less

Addressing the challenges of phenotyping pediatric pulmonary vascular disease

PubMed Central

Goss, Kara N.; Everett, Allen D.; Mourani, Peter M.; Baker, Christopher D.; Abman, Steven H.

2017-01-01

Pediatric pulmonary vascular disease (PVD) and pulmonary hypertension (PH) represent phenotypically and pathophysiologically diverse disease categories, contributing substantial morbidity and mortality to a complex array of pediatric conditions. Here, we review the multifactorial nature of pediatric PVD, with an emphasis on improved recognition, phenotyping, and endotyping strategies for pediatric PH. Novel tailored approaches to diagnosis and treatment in pediatric PVD, as well as the implications for long-term outcomes, are highlighted. PMID:28680562

SERDP and ESTCP Workshop on Long Term Management of Contaminated Groundwater Sites

DTIC Science & Technology

2013-11-01

Yasmin Shafiq HydroGeoLogic, Inc. Allen Shapiro, Ph.D. U.S. Geological Survey Thomas Simpkin, Ph.D. CH2M HILL Mike Singletary NAVFAC...Buffalo ALLEN SHAPIRO, U.S. Geological Survey LENNY SIEGEL, Center for Public Environmental Oversight WILLIAM WALSH, Pepper Hamilton LLP Presenters...MNA Challenges Not appropriate for many CVOC sites (McGuire et al., Historical and Retrospective Survey of MNA... WSRC-TR-2003-00333) MNA Challenges

Sand smelt ability to cope and recover from ocean's elevated CO2 levels.

PubMed

Silva, Cátia S E; Lemos, Marco F L; Faria, Ana M; Lopes, Ana F; Mendes, Susana; Gonçalves, Emanuel J; Novais, Sara C

2018-06-15

Considered a major environmental concern, ocean acidification has induced a recent research boost into effects on marine biodiversity and possible ecological, physiological, and behavioural impacts. Although the majority of literature indicate negative effects of future acidification scenarios, most studies are conducted for just a few days or weeks, which may be insufficient to detect the capacity of an organism to adjust to environmental changes through phenotypic plasticity. Here, the effects and the capacity of sand smelt larvae Atherina presbyter to cope and recover (through a treatment combination strategy) from short (15 days) and long-term exposure (45 days) to increasing pCO 2 levels (control: ~515 μatm, pH = 8.07; medium: ~940 μatm, pH = 7.84; high: ~1500 μatm, pH = 7.66) were measured, addressing larval development traits, behavioural lateralization, and biochemical biomarkers related with oxidative stress and damage, and energy metabolism and reserves. Although behavioural lateralization was not affected by high pCO 2 exposure, morphometric changes, energetic costs, and oxidative stress damage were impacted differently through different exposures periods. Generally, short-time exposures led to different responses to either medium or high pCO 2 levels (e.g. development, cellular metabolism, or damage), while on the long-term the response patterns tend to become similar between them, with both acidification scenarios inducing DNA damage and tending to lower growth rates. Additionally, when organisms were transferred to lower acidified condition, they were not able to recover from the mentioned DNA damage impacts. Overall, results suggest that exposure to future ocean acidification scenarios can induce sublethal effects on early life-stages of fish, but effects are dependent on duration of exposure, and are likely not reversible. Furthermore, to improve our understanding on species sensitivity and adaptation strategies, results reinforce the need to use multiple biological endpoints when assessing the effects of ocean acidification on marine organisms. Copyright © 2018 Elsevier Inc. All rights reserved.

Differences in the skin surface pH and bacterial microflora due to the long-term application of synthetic detergent preparations of pH 5.5 and pH 7.0. Results of a crossover trial in healthy volunteers.

PubMed

Korting, H C; Hübner, K; Greiner, K; Hamm, G; Braun-Falco, O

1990-01-01

Skin cleansing preparations consisting of identical synthetic detergents but differing in pH-value (pH 5.5 and 7.0) were applied twice daily on the forehead and forearm of healthy volunteers in a randomized crossover trial. The skin surface pH was found to be significantly higher when the neutral preparation had been used, as was the propionibacterial count (p less than 0.05). The number of propionibacteria was significantly linked to the skin pH. Hence even minor differences in the pH of skin cleansing preparations seem to be of importance for the integrity of the skin surface. This should be taken into account when planning the formulation of optimal skin care products.

Effects of maturation and acidosis on the chaos-like complexity of the neural respiratory output in the isolated brainstem of the tadpole, Rana esculenta

PubMed Central

Samara, Ziyad; Fiamma, Marie-Noëlle; Bautin, Nathalie; Ranohavimparany, Anja; Le Coz, Patrick; Golmard, Jean-Louis; Darré, Pierre; Zelter, Marc; Poon, Chi-Sang; Similowski, Thomas

2011-01-01

Human ventilation at rest exhibits mathematical chaos-like complexity that can be described as long-term unpredictability mediated (in whole or in part) by some low-dimensional nonlinear deterministic process. Although various physiological and pathological situations can affect respiratory complexity, the underlying mechanisms remain incompletely elucidated. If such chaos-like complexity is an intrinsic property of central respiratory generators, it should appear or increase when these structures mature or are stimulated. To test this hypothesis, we employed the isolated tadpole brainstem model [Rana (Pelophylax) esculenta] and recorded the neural respiratory output (buccal and lung rhythms) of pre- (n = 8) and postmetamorphic tadpoles (n = 8), at physiologic (7.8) and acidic pH (7.4). We analyzed the root mean square of the cranial nerve V or VII neurograms. Development and acidosis had no effect on buccal period. Lung frequency increased with development (P < 0.0001). It also increased with acidosis, but in postmetamorphic tadpoles only (P < 0.05). The noise-titration technique evidenced low-dimensional nonlinearities in all the postmetamorphic brainstems, at both pH. Chaos-like complexity, assessed through the noise limit, increased from pH 7.8 to pH 7.4 (P < 0.01). In contrast, linear models best fitted the ventilatory rhythm in all but one of the premetamorphic preparations at pH 7.8 (P < 0.005 vs. postmetamorphic) and in four at pH 7.4 (not significant vs. postmetamorphic). Therefore, in a lower vertebrate model, the brainstem respiratory central rhythm generator accounts for ventilatory chaos-like complexity, especially in the postmetamorphic stage and at low pH. According to the ventilatory generators homology theory, this may also be the case in mammals. PMID:21325645

Effects of maturation and acidosis on the chaos-like complexity of the neural respiratory output in the isolated brainstem of the tadpole, Rana esculenta.

PubMed

Straus, Christian; Samara, Ziyad; Fiamma, Marie-Noëlle; Bautin, Nathalie; Ranohavimparany, Anja; Le Coz, Patrick; Golmard, Jean-Louis; Darré, Pierre; Zelter, Marc; Poon, Chi-Sang; Similowski, Thomas

2011-05-01

Human ventilation at rest exhibits mathematical chaos-like complexity that can be described as long-term unpredictability mediated (in whole or in part) by some low-dimensional nonlinear deterministic process. Although various physiological and pathological situations can affect respiratory complexity, the underlying mechanisms remain incompletely elucidated. If such chaos-like complexity is an intrinsic property of central respiratory generators, it should appear or increase when these structures mature or are stimulated. To test this hypothesis, we employed the isolated tadpole brainstem model [Rana (Pelophylax) esculenta] and recorded the neural respiratory output (buccal and lung rhythms) of pre- (n = 8) and postmetamorphic tadpoles (n = 8), at physiologic (7.8) and acidic pH (7.4). We analyzed the root mean square of the cranial nerve V or VII neurograms. Development and acidosis had no effect on buccal period. Lung frequency increased with development (P < 0.0001). It also increased with acidosis, but in postmetamorphic tadpoles only (P < 0.05). The noise-titration technique evidenced low-dimensional nonlinearities in all the postmetamorphic brainstems, at both pH. Chaos-like complexity, assessed through the noise limit, increased from pH 7.8 to pH 7.4 (P < 0.01). In contrast, linear models best fitted the ventilatory rhythm in all but one of the premetamorphic preparations at pH 7.8 (P < 0.005 vs. postmetamorphic) and in four at pH 7.4 (not significant vs. postmetamorphic). Therefore, in a lower vertebrate model, the brainstem respiratory central rhythm generator accounts for ventilatory chaos-like complexity, especially in the postmetamorphic stage and at low pH. According to the ventilatory generators homology theory, this may also be the case in mammals.

Trophic transfer of essential elements in the clownfish Amphiprion ocellaris in the context of ocean acidification.

PubMed

Jacob, Hugo; Pouil, Simon; Lecchini, David; Oberhänsli, François; Swarzenski, Peter; Metian, Marc

2017-01-01

Little information exists on the effects of ocean acidification (OA) on the digestive and post-digestive processes in marine fish. Here, we investigated OA impacts (Δ pH = 0.5) on the trophic transfer of select trace elements in the clownfish Amphiprion ocellaris using radiotracer techniques. Assimilation efficiencies of three essential elements (Co, Mn and Zn) as well as their other short-term and long-term kinetic parameters in juvenile clownfish were not affected by this experimental pH change. In complement, their stomach pH during digestion were not affected by the variation in seawater pH. Such observations suggest that OA impacts do not affect element assimilation in these fish. This apparent pCO2 tolerance may imply that clownfish have the ability to self-regulate pH shifts in their digestive tract, or that they can metabolically accommodate such shifts. Such results are important to accurately assess future OA impacts on diverse marine biota, as such impacts are highly species specific, complex, and may be modulated by species-specific metabolic processes.

Trophic transfer of essential elements in the clownfish Amphiprion ocellaris in the context of ocean acidification

PubMed Central

Pouil, Simon; Lecchini, David; Oberhänsli, François; Swarzenski, Peter; Metian, Marc

2017-01-01

Little information exists on the effects of ocean acidification (OA) on the digestive and post-digestive processes in marine fish. Here, we investigated OA impacts (Δ pH = 0.5) on the trophic transfer of select trace elements in the clownfish Amphiprion ocellaris using radiotracer techniques. Assimilation efficiencies of three essential elements (Co, Mn and Zn) as well as their other short-term and long-term kinetic parameters in juvenile clownfish were not affected by this experimental pH change. In complement, their stomach pH during digestion were not affected by the variation in seawater pH. Such observations suggest that OA impacts do not affect element assimilation in these fish. This apparent pCO2 tolerance may imply that clownfish have the ability to self-regulate pH shifts in their digestive tract, or that they can metabolically accommodate such shifts. Such results are important to accurately assess future OA impacts on diverse marine biota, as such impacts are highly species specific, complex, and may be modulated by species-specific metabolic processes. PMID:28399186

Development of a colorimetric microfluidic pH sensor for autonomous seawater measurements.

PubMed

Rérolle, Victoire M C; Floquet, Cedric F A; Harris, Andy J K; Mowlem, Matt C; Bellerby, Richard R G J; Achterberg, Eric P

2013-07-05

High quality carbonate chemistry measurements are required in order to fully understand the dynamics of the oceanic carbonate system. Seawater pH data with good spatial and temporal coverage are particularly critical to apprehend ocean acidification phenomena and their consequences. There is a growing need for autonomous in situ instruments that measure pH on remote platforms. Our aim is to develop an accurate and precise autonomous in situ pH sensor for long term deployment on remote platforms. The widely used spectrophotometric pH technique is capable of the required high-quality measurements. We report a key step towards the miniaturization of a colorimetric pH sensor with the successful implementation of a simple microfluidic design with low reagent consumption. The system is particularly adapted to shipboard deployment: high quality data was obtained over a period of more than a month during a shipboard deployment in northwest European shelf waters, and less than 30 mL of indicator was consumed. The system featured a short term precision of 0.001 pH (n=20) and an accuracy within the range of a certified Tris buffer (0.004 pH). The quality of the pH system measurements have been checked using various approaches: measurements of certified Tris buffer, measurement of certified seawater for DIC and TA, comparison of measured pH against calculated pH from pCO2, DIC and TA during the cruise in northwest European shelf waters. All showed that our measurements were of high quality. The measurements were made close to in situ temperature (+0.2°C) in a sampling chamber which had a continuous flow of the ship's underway seawater supply. The optical set up was robust and relatively small due to the use of an USB mini-spectrometer, a custom made polymeric flow cell and an LED light source. The use of a three wavelength LED with detection that integrated power across the whole of each LED output spectrum indicated that low wavelength resolution detectors can be used instead of the current USB mini spectrophotometer. Artefacts due to the polychromatic light source and inhomogeneity in the absorption cell are shown to have a negligible impact on the data quality. The next step in the miniaturization of the sensor will be the incorporation of a photodiode as detector to replace the spectrophotometer. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

The collaborative African genomics network training program: a trainee perspective on training the next generation of African scientists.

PubMed

Mlotshwa, Busisiwe C; Mwesigwa, Savannah; Mboowa, Gerald; Williams, Lesedi; Retshabile, Gaone; Kekitiinwa, Adeodata; Wayengera, Misaki; Kyobe, Samuel; Brown, Chester W; Hanchard, Neil A; Mardon, Graeme; Joloba, Moses; Anabwani, Gabriel; Mpoloka, Sununguko W

2017-07-01

The Collaborative African Genomics Network (CAfGEN) aims to establish sustainable genomics research programs in Botswana and Uganda through long-term training of PhD students from these countries at Baylor College of Medicine. Here, we present an overview of the CAfGEN PhD training program alongside trainees' perspectives on their involvement. Historically, collaborations between high-income countries (HICs) and low- and middle-income countries (LMICs), or North-South collaborations, have been criticized for the lack of a mutually beneficial distribution of resources and research findings, often undermining LMICs. CAfGEN plans to address this imbalance in the genomics field through a program of technology and expertise transfer to the participating LMICs. An overview of the training program is presented. Trainees from the CAfGEN project summarized their experiences, looking specifically at the training model, benefits of the program, challenges encountered relating to the cultural transition, and program outcomes after the first 2 years. Collaborative training programs like CAfGEN will not only help establish sustainable long-term research initiatives in LMICs but also foster stronger North-South and South-South networks. The CAfGEN model offers a framework for the development of training programs aimed at genomics education for those for whom genomics is not their "first language." Genet Med advance online publication 06 April 2017.

The collaborative African genomics network training program: a trainee perspective on training the next generation of African scientists

PubMed Central

Mlotshwa, Busisiwe C.; Mwesigwa, Savannah; Mboowa, Gerald; Williams, Lesedi; Retshabile, Gaone; Kekitiinwa, Adeodata; Wayengera, Misaki; Kyobe, Samuel; Brown, Chester W.; Hanchard, Neil A.; Mardon, Graeme; Joloba, Moses; Anabwani, Gabriel; Mpoloka, Sununguko W.

2017-01-01

Purpose: The Collaborative African Genomics Network (CAfGEN) aims to establish sustainable genomics research programs in Botswana and Uganda through long-term training of PhD students from these countries at Baylor College of Medicine. Here, we present an overview of the CAfGEN PhD training program alongside trainees’ perspectives on their involvement. Background: Historically, collaborations between high-income countries (HICs) and low- and middle-income countries (LMICs), or North–South collaborations, have been criticized for the lack of a mutually beneficial distribution of resources and research findings, often undermining LMICs. CAfGEN plans to address this imbalance in the genomics field through a program of technology and expertise transfer to the participating LMICs. Methods: An overview of the training program is presented. Trainees from the CAfGEN project summarized their experiences, looking specifically at the training model, benefits of the program, challenges encountered relating to the cultural transition, and program outcomes after the first 2 years. Conclusion: Collaborative training programs like CAfGEN will not only help establish sustainable long-term research initiatives in LMICs but also foster stronger North–South and South–South networks. The CAfGEN model offers a framework for the development of training programs aimed at genomics education for those for whom genomics is not their “first language.” Genet Med advance online publication 06 April 2017 PMID:28383545

Minorities Striving and Pursuing Higher Degrees of Success in Earth System Science (MS PHD'S) Beyond the PhD Professional Development Program: A Pilot Project

NASA Astrophysics Data System (ADS)

Johnson, A.; Jearld, A.; Williamson Whitney, V.; Huggans, M.; Ricciardi, L.; Thomas, S. H.; Jansma, P. E.

2012-12-01

In 2011 the Minorities Striving and Pursuing Higher Degrees of Success in Earth System Science (MS PHD'S)® initiative launched its newest activity entitled the MS PHD'S "Beyond the PhD (B-PhD) Professional Development Program." This exciting new program was designed to facilitate the development of a new community of underrepresented minority (URM) doctoral candidates and recent doctorate degree recipients in Earth system science (ESS)-related fields. The MS PHD'S B-PhD provides customized support and advocacy for MS PHD'S B-PhD participants in order to facilitate smoother and informed transitions from graduate school, to postdoctoral and tenure-track positions, as well as other "first" jobs in government, industry, and non-profit organizations. In November 2011 the first cohort of MS PHD'S B-PhD participants engaged in intensive sessions on the following topics: "Toolkits for Success for Academia, Business/Industry, Federal Government and Non-Profits", "Defining Short, Mid and Long Term Career Goals", "Accessing and Refining Skill Sets and Other Door Openers", "International Preparation and Opportunities", "Paying it Forward/Lifting as You Climb", and "Customized Strategies for Next Steps". This pilot event, which was hosted by the University of Texas at Arlington's (UTA) College of Science, also provided opportunities for participants to serve as guest lecturers in the UTA's Colleges of Science and Engineering and included one-on-one discussions with MS PHD'S B-PhD mentors and guest speakers who are well established within their individual ESS fields. Insights regarding opportunities, challenges and obstacles commonly faced by URMs within the ESS fields, as well as strategies for success were shared by MS PHD'S B-PhD mentors and guest speakers. Survey results indicate that MS PHD'S B-PhD participants appreciated not only the material covered during this pilot activity, but also appreciated the opportunity to become part of a community of young URM ESS professionals who are committed to achieving successful careers and supporting one another. This presentation will discuss outcomes from this pilot project, the use of social media to track and support ongoing MS PHD'S B-PhD activities, and "next steps" for the MS PHD'S B-PhD Professional Development Program.

Quality testing of autoclaved rodent drinking water during short-term and long-term storage.

PubMed

Peveler, Jessica L; Crisler, Robin; Hickman, Deb

2015-06-01

All animals need clean water to drink. At the authors' animal facility, drinking water for immunocompromised rodents is filtered by reverse osmosis, acidified during bottling and sterilized in an autoclave. Autoclaved water bottles can be stored in unopened autoclave bags for 7 d or in opened bags for 2 d; if not used during that time, they are emptied, cleaned, refilled and sterilized again. The authors wished to determine whether the storage period of 2-7 d was adequate and necessary to ensure the quality of drinking water. They tested water bottles for pH levels and for the presence of adenosine triphosphate as a measure of organic contamination during short-term and long-term storage. The pH of autoclaved drinking water generally remained stable during storage. Furthermore, no instances of organic contamination were detected in autoclaved water bottles stored for up to 22 d in unopened bags and only one instance was detected in bottles stored for up to 119 d in opened bags in a room with individually ventilated cages. On the basis of these findings, the acceptable storage period for autoclaved water bottles in opened bags at the authors' facility was extended to 21 d.

Experience with long-term glucocorticoid treatment in congenital adrenal hyperplasia: growth pattern compared with genetic height potential.

PubMed

Aycan, Zehra; Ocal, Gonul; Berberoglu, Merih; Cetinkaya, Ergun; Adiyaman, Pelin; Evliyaoglu, Olcay

2006-03-01

Long-term replacement treatment with high doses of steroids in congenital adrenal hyperplasia (CAH) is known to have a negative influence on growth. We evaluated the effects of long-term steroid treatment in patients with classical CAH on height development in relation to genetic height potential. Twenty-three patients with CAH (16 females, 7 males, mean age: 9.8 +/- 3.5 years) were included in this longitudinal study. The effect of steroid treatment on growth was determined by monitoring patients for 8.61 +/- 3.46 years (2-17 years) while they were treated with hydrocortisone at a mean dosage of 17.64 +/- 3.60 mg/m2/day. The height standard deviation scores (Ht-SDS), target Ht-SDS, and corrected Ht-SDS for target height was calculated for all patients. Predicted adult height according to bone age was calculated and it was determined whether height was developing according to the genetic height potential. In addition, patients were grouped as 'tight control' or 'poor control' according to their mean serum 17OH-progesterone or ACTH levels while on treatment. We evaluated whether height development was different for the tight and poor control groups. The mean chronological age of our patients at the time of the study was 9.89 +/- 3.53 years, Ht-SDS -0.77 +/- 1.57, target height (TH) 161.03 +/- 6.54 cm, TH-SDS -0.60 +/- 0.90, predicted height (PH) 157.2 +/- 11.16 cm, PH-SDS -1.1 +/- 1.69, and corrected Ht-SDS -0.75 +/- 1.14. There was no significant difference between the actual Ht-SDS and TH-SDS of our patients (p >0.05) but the corrected Ht-SDS was less than zero. Only 28.5% of our patients had normal height according to their genetic potential while 71.5% were shorter than their genetic height potential. While the Ht-SDS and corrected Ht-SDS were similar in the tight and poor metabolic control groups, the predicted height was significantly greater in the tight control group. We demonstrated that a hydrocortisone dose of 17.64 +/- 3.60 mg/m2/day in classical CAH had a negative influence on height development for genetic height potential in 8.5 years of follow-up and that it is necessary to use the lowest possible steroid dosage by individualizing the dose.

Water quality changes in acid mine drainage streams in Gangneung, Korea, 10 years after treatment with limestone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shim, Moo Joon; Choi, Byoung Young; Lee, Giehyeon

To determine the long-term effectiveness of the limestone treatment for acid mine drainage (AMD) in Gangneung, Korea, we investigated the elemental distribution in streams impacted by AMD and compared the results of previous studies before and approximately 10 years after the addition of limestone. Addition of limestone in 1999 leads to a pH increase in 2008, and with the exception of Ca, the elemental concentrations (e.g., Fe, Mn, Mg, Sr, Ni, Zn, S) in the streams decreased. The pH was 2.5–3 before the addition of limestone and remained stable at around 4.5–5 from 2008 to 2011, suggesting the reactivity ofmore » the added limestone was diminished and that an alternative approach is needed to increase the pH up to circumneutral range and maintain effective long-term treatment. To identify the processes causing the decrease in the elemental concentrations, we also examined the spatial (approximately 7 km) distribution over three different types of streams affected by the AMD. Lastly, the elemental distribution was mainly controlled by physicochemical processes including redox reactions, dilution on mixing, and co-precipitation/adsorption with Fe (hydr)oxides.« less

Water quality changes in acid mine drainage streams in Gangneung, Korea, 10 years after treatment with limestone

DOE PAGES

Shim, Moo Joon; Choi, Byoung Young; Lee, Giehyeon; ...

2015-09-28

To determine the long-term effectiveness of the limestone treatment for acid mine drainage (AMD) in Gangneung, Korea, we investigated the elemental distribution in streams impacted by AMD and compared the results of previous studies before and approximately 10 years after the addition of limestone. Addition of limestone in 1999 leads to a pH increase in 2008, and with the exception of Ca, the elemental concentrations (e.g., Fe, Mn, Mg, Sr, Ni, Zn, S) in the streams decreased. The pH was 2.5–3 before the addition of limestone and remained stable at around 4.5–5 from 2008 to 2011, suggesting the reactivity ofmore » the added limestone was diminished and that an alternative approach is needed to increase the pH up to circumneutral range and maintain effective long-term treatment. To identify the processes causing the decrease in the elemental concentrations, we also examined the spatial (approximately 7 km) distribution over three different types of streams affected by the AMD. Lastly, the elemental distribution was mainly controlled by physicochemical processes including redox reactions, dilution on mixing, and co-precipitation/adsorption with Fe (hydr)oxides.« less

Effects of Ocean Acidification on the Brown Alga Padina pavonica: Decalcification Due to Acute and Chronic Events

PubMed Central

Gil-Díaz, Teba; Haroun, Ricardo; Tuya, Fernando; Betancor, Séfora; Viera-Rodríguez, María A.

2014-01-01

Since the industrial revolution, anthropogenic CO2 emissions have caused ocean acidification, which particularly affects calcified organisms. Given the fan-like calcified fronds of the brown alga Padina pavonica, we evaluated the acute (short-term) effects of a sudden pH drop due to a submarine volcanic eruption (October 2011–early March 2012) affecting offshore waters around El Hierro Island (Canary Islands, Spain). We further studied the chronic (long-term) effects of the continuous decrease in pH in the last decades around the Canarian waters. In both the observational and retrospective studies (using herbarium collections of P. pavonica thalli from the overall Canarian Archipelago), the percent of surface calcium carbonate coverage of P. pavonica thalli were contrasted with oceanographic data collected either in situ (volcanic eruption event) or from the ESTOC marine observatory data series (herbarium study). Results showed that this calcified alga is sensitive to acute and chronic environmental pH changes. In both cases, pH changes predicted surface thallus calcification, including a progressive decalcification over the last three decades. This result concurs with previous studies where calcareous organisms decalcify under more acidic conditions. Hence, Padina pavonica can be implemented as a bio-indicator of ocean acidification (at short and long time scales) for monitoring purposes over wide geographic ranges, as this macroalga is affected and thrives (unlike strict calcifiers) under more acidic conditions. PMID:25268231

Long term (1987-2012) trends in water chemistry of acid sensitive Swedish lakes

NASA Astrophysics Data System (ADS)

Futter, Martyn; Valinia, Salar; Fölster, Jens

2014-05-01

Acidification of surface waters is a serious concern in Sweden. During the 1970s and 1980s, many surface waters in Sweden were acidified by long-range pollution. Legislated emissions reductions have led to the recovery of many water bodies but today, there are concerns about the possibility of re-acidification. Sweden is committed to a goal of natural acidification only (i.e. no anthropogenic acidification). Here, we present long term (1987-2012) trends in strong acid anion, base cation, organic carbon and alkalinity measurements. Lakes are defined as acidified in Sweden if pH is more than 0.4 units less than a reference (1860) pH estimated using MAGIC, a widely used process-based model of acidification. Using this criteria, many acid sensitive Swedish lakes are still acidified. A changing climate and more intensive forest harvesting may further delay the recovery from acidification. Average measured alkalinity in the 38 lakes presented here was <= 0.02 mekv/l between 2000-2012. Strong acid anion concentrations declined, primarily as a result of declines in sulfate. Chloride is now the dominant anion in many of these lakes. Base cations concentrations have declined less rapidly, leading to an increase in charge balance ANC. This increase in charge balance ANC has not been matched by an increase in measured alkalinity. Total organic carbon concentrations have increased significantly in many of these lakes, to the point where modeled organic acidity is now approximately equal to inorganic acidity. While the results presented here conform to acidification theory, they illustrate the value of long-term monitoring for assessing the effects of pollutant reduction measures, identifying new threats to water quality and corroborating model results. Most importantly, the long-term monitoring results presented here can be an important tool for informing environmental policy.

Investigation of the leaching behavior of lead in stabilized/solidified waste using a two-year semi-dynamic leaching test.

PubMed

Xue, Qiang; Wang, Ping; Li, Jiang-Shan; Zhang, Ting-Ting; Wang, Shan-Yong

2017-01-01

Long-term leaching behavior of contaminant from stabilization/solidification (S/S) treated waste stays unclear. For the purpose of studying long-term leaching behavior and leaching mechanism of lead from cement stabilized soil under different pH environment, semi-dynamic leaching test was extended to two years to investigate leaching behaviors of S/S treated lead contaminated soil. Effectiveness of S/S treatment in different scenarios was evaluated by leachability index (LX) and effective diffusion coefficient (D e ). In addition, the long-term leaching mechanism was investigated at different leaching periods. Results showed that no significant difference was observed among the values of the cumulative release of Pb, D e and LX in weakly alkaline and weakly acidic environment (pH value varied from 5.00 to 10.00), and all the controlling leaching mechanisms of the samples immersed in weakly alkaline and weakly acidic environments turned out to be diffusion. Strong acid environment would significantly affect the leaching behavior and leaching mechanism of lead from S/S monolith. The two-year variation of D e appeared to be time dependent, and D e values increased after the 210 th day in weakly alkaline and weakly acidic environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biochar as possible long-term soil amendment for phytostabilisation of TE-contaminated soils.

PubMed

Bopp, Charlotte; Christl, Iso; Schulin, Rainer; Evangelou, Michael W H

2016-09-01

Soils contaminated by trace elements (TEs) pose a high risk to their surrounding areas as TEs can spread by wind and water erosion or leaching. A possible option to reduce TE transfer from these sites is phytostabilisation. It is a long-term and cost-effective rehabilitation strategy which aims at immobilising TEs within the soil by vegetation cover and amendment application. One possible amendment is biochar. It is charred organic matter which has been shown to immobilise metals due to its high surface area and alkaline pH. Doubts have been expressed about the longevity of this immobilising effect as it could dissipate once the carbonates in the biochar have dissolved. Therefore, in a pot experiment, we determined plant metal uptake by ryegrass (Lolium perenne) from three TE-contaminated soils treated with two biochars, which differed only in their pH (acidic, 2.80; alkaline, 9.33) and carbonate (0.17 and 7.3 %) content. Root biomass was increased by the application of the alkaline biochar due to the decrease in TE toxicity. Zinc and Cu bioavailability and plant uptake were equally reduced by both biochars, showing that surface area plays an important role in metal immobilisation. Biochar could serve as a long-term amendment for TE immobilisation even after its alkalinity effect has dissipated.

Formic acid excretion in rats exposed to trichloroethylene: a possible explanation for renal toxicity in long-term studies.

PubMed

Green, T; Dow, J; Foster, J R; Hext, P M

1998-05-15

Rats exposed to trichloroethylene, either by gavage or by inhalation, excreted large amounts of formic acid in urine which was accompanied by a change in urinary pH, increased excretion of ammonia, and slight increases in the excretion of calcium. Following a single 6-h exposure to 500 ppm trichloroethylene, the excretion of formic acid was comparable to that seen after a 500 mg/kg dose of formic acid itself, yet the half-life was markedly different. Formate excretion in trichloroethylene treated rats reached a maximum on day 2 and had a half-life of 4-5 days, whereas urinary excretion was complete within 24 h following a single dose of formic acid itself. Formic acid was shown not to be a metabolite of trichloroethylene. When rats were exposed to 250 or 500 ppm trichloroethylene, 6 h/day, for 28 days, the only significant effects were increased formic acid and ammonia excretion, and a change in urinary pH. There was no evidence of morphological liver or kidney damage. Long-term exposure to formic acid is known to cause kidney damage suggesting that excretion of this acid may contribute to the kidney damage seen in the long-term studies with trichloroethylene.

Drivers of spatio-temporal changes in paddy soil pH in Jiangxi Province, China from 1980 to 2010.

PubMed

Guo, Xi; Li, Hongyi; Yu, Huimin; Li, Weifeng; Ye, Yingcong; Biswas, Asim

2018-02-09

The spatio-temporal distribution soil pH is critical for understanding the productivity and long-term sustainability of our agri-ecosystem. This study quantified the spatio-temporal distribution of paddy soil pH in Jiangxi province, China, and the potential driver of the change between 1980 and 2010. Data from the Soil Survey Information of Jiangxi province (1980s) and Jiangxi Soil Testing and Fertilizer Recommendation study (2010s) were collected and categorized into six pH ranges from strongly-acidic to strongly-alkaline with unit pH differences. Changes were calculated from the maps developed using the Pedological Knowledge base for 1980s data (without geolocation) and geostatistical methods for the 2010s data (geolocated). An overall 0.6-unit decrease and a major shift of soil pH from weakly-acidic (54% → 18%) to acidic (35% → 74%) was observed over the province in a scattered fashion with concentration in the central part and the Poyang Lake area. About half of the area under paddy cultivation went through acidification by at least one pH unit and 7% by at least 2 pH units, while 40% of the area remained unchanged. Excessive fertilizer application and acid-rain intensity contributed to the acidification. Thus, a more knowledge-based and comprehensive fertilizer management should be adopted to make paddy production sustainable in the province.

Cost-Effectiveness of 2009 Pandemic Influenza A(H1N1) Vaccination in the United States

PubMed Central

Prosser, Lisa A.; Lavelle, Tara A.; Fiore, Anthony E.; Bridges, Carolyn B.; Reed, Carrie; Jain, Seema; Dunham, Kelly M.; Meltzer, Martin I.

2011-01-01

Background Pandemic influenza A(H1N1) (pH1N1) was first identified in North America in April 2009. Vaccination against pH1N1 commenced in the U.S. in October 2009 and continued through January 2010. The objective of this study was to evaluate the cost-effectiveness of pH1N1 vaccination. Methodology A computer simulation model was developed to predict costs and health outcomes for a pH1N1 vaccination program using inactivated vaccine compared to no vaccination. Probabilities, costs and quality-of-life weights were derived from emerging primary data on pH1N1 infections in the US, published and unpublished data for seasonal and pH1N1 illnesses, supplemented by expert opinion. The modeled target population included hypothetical cohorts of persons aged 6 months and older stratified by age and risk. The analysis used a one-year time horizon for most endpoints but also includes longer-term costs and consequences of long-term sequelae deaths. A societal perspective was used. Indirect effects (i.e., herd effects) were not included in the primary analysis. The main endpoint was the incremental cost-effectiveness ratio in dollars per quality-adjusted life year (QALY) gained. Sensitivity analyses were conducted. Results For vaccination initiated prior to the outbreak, pH1N1 vaccination was cost-saving for persons 6 months to 64 years under many assumptions. For those without high risk conditions, incremental cost-effectiveness ratios ranged from $8,000–$52,000/QALY depending on age and risk status. Results were sensitive to the number of vaccine doses needed, costs of vaccination, illness rates, and timing of vaccine delivery. Conclusions Vaccination for pH1N1 for children and working-age adults is cost-effective compared to other preventive health interventions under a wide range of scenarios. The economic evidence was consistent with target recommendations that were in place for pH1N1 vaccination. We also found that the delays in vaccine availability had a substantial impact on the cost-effectiveness of vaccination. PMID:21829456

Identification of long-term trends and seasonality in high-frequency water quality data from the Yangtze River basin, China

PubMed Central

He, Bin; Chen, Yaning; Zou, Shan; Wang, Yi; Nover, Daniel; Chen, Wen; Yang, Guishan

2018-01-01

Comprehensive understanding of the long-term trends and seasonality of water quality is important for controlling water pollution. This study focuses on spatio-temporal distributions, long-term trends, and seasonality of water quality in the Yangtze River basin using a combination of the seasonal Mann-Kendall test and time-series decomposition. The used weekly water quality data were from 17 environmental stations for the period January 2004 to December 2015. Results show gradual improvement in water quality during this period in the Yangtze River basin and greater improvement in the Uppermost Yangtze River basin. The larger cities, with high GDP and population density, experienced relatively higher pollution levels due to discharge of industrial and household wastewater. There are higher pollution levels in Xiang and Gan River basins, as indicated by higher NH4-N and CODMn concentrations measured at the stations within these basins. Significant trends in water quality were identified for the 2004–2015 period. Operations of the three Gorges Reservoir (TGR) enhanced pH fluctuations and possibly attenuated CODMn, and NH4-N transportation. Finally, seasonal cycles of varying strength were detected for time-series of pollutants in river discharge. Seasonal patterns in pH indicate that maxima appear in winter, and minima in summer, with the opposite true for CODMn. Accurate understanding of long-term trends and seasonality are necessary goals of water quality monitoring system efforts and the analysis methods described here provide essential information for effectively controlling water pollution. PMID:29466354

Oxygen and sulfur isotope systematics of sulfate produced by bacterial and abiotic oxidation of pyrite

USGS Publications Warehouse

Balci, N.; Shanks, Wayne C.; Mayer, B.; Mandernack, K.W.

2007-01-01

To better understand reaction pathways of pyrite oxidation and biogeochemical controls on ??18O and ??34S values of the generated sulfate in acid mine drainage (AMD) and other natural environments, we conducted a series of pyrite oxidation experiments in the laboratory. Our biological and abiotic experiments were conducted under aerobic conditions by using O2 as an oxidizing agent and under anaerobic conditions by using dissolved Fe(III)aq as an oxidant with varying ??18OH2O values in the presence and absence of Acidithiobacillus ferrooxidans. In addition, aerobic biological experiments were designed as short- and long-term experiments where the final pH was controlled at ???2.7 and 2.2, respectively. Due to the slower kinetics of abiotic sulfide oxidation, the aerobic abiotic experiments were only conducted as long term with a final pH of ???2.7. The ??34SSO4 values from both the biological and abiotic anaerobic experiments indicated a small but significant sulfur isotope fractionation (???-0.7???) in contrast to no significant fractionation observed from any of the aerobic experiments. Relative percentages of the incorporation of water-derived oxygen and dissolved oxygen (O2) to sulfate were estimated, in addition to the oxygen isotope fractionation between sulfate and water, and dissolved oxygen. As expected, during the biological and abiotic anaerobic experiments all of the sulfate oxygen was derived from water. The percentage incorporation of water-derived oxygen into sulfate during the oxidation experiments by O2 varied with longer incubation and lower pH, but not due to the presence or absence of bacteria. These percentages were estimated as 85%, 92% and 87% from the short-term biological, long-term biological and abiotic control experiments, respectively. An oxygen isotope fractionation effect between sulfate and water (??18 OSO4 s(-) H2 O) of ???3.5??? was determined for the anaerobic (biological and abiotic) experiments. This measured ??18 OSO42 - s(-) H2 O value was then used to estimate the oxygen isotope fractionation effects (??18 OSO42 - s(-) O2) between sulfate and dissolved oxygen in the aerobic experiments which were -10.0???, -10.8???, and -9.8??? for the short-term biological, long-term biological and abiotic control experiments, respectively. Based on the similarity between ??18OSO4 values in the biological and abiotic experiments, it is suggested that ??18OSO4 values cannot be used to distinguish biological and abiotic mechanisms of pyrite oxidation. The results presented here suggest that Fe(III)aq is the primary oxidant for pyrite at pH < 3, even in the presence of dissolved oxygen, and that the main oxygen source of sulfate is water-oxygen under both aerobic and anaerobic conditions. ?? 2007 Elsevier Ltd. All rights reserved.

[Effects of long-term fertilization on pH buffer system of sandy loam calcareous fluvor-aquic soil].

PubMed

Wang, Ji-Dong; Qi, Bing-Jie; Zhang, Yong-Chun; Zhang, Ai-Jun; Ning, Yun-Wang; Xu, Xian-Ju; Zhang, Hui; Ma, Hong-Bo

2012-04-01

Soil samples (0-80 cm) were collected from a 30-year fertilization experimental site in Xuzhou, Jiangsu Province of East China to study the variations of the pH, calcium carbonate and active calcium carbonate contents, and pH buffer capacity of sandy loam calcareous fluvor-aquic soil under different fertilization treatments. Thirty-year continuous application of different fertilizers accelerated the acidification of topsoil (0-20 cm), with the soil pH decreased by 0.41-0.70. Under different fertilization, the soil pH buffer capacity (pHBC) varied from 15.82 to 21.96 cmol x kg(-1). As compared with no fertilization, single N fertilization decreased the pHBC significantly, but N fertilization combined with organic fertilization could significantly increase the pHBC. The soil pHBC had significant positive correlations with soil calcium carbonate and active calcium carbonate contents, but less correlation with soil organic matter content and soil cation exchange capacity, suggesting that after a long-term fertilization, the sandy loam calcareous fluvor-aquic soil was still of an elementary calcium carbonate buffer system, and soil organic matter and cation exchange capacity contributed little to the buffer system. The soil calcium carbonate and active calcium carbonate contents were greater in 0-40 cm than in 40-80 cm soil layer. Comparing with soil calcium carbonate, soil active calcium carbonate was more sensitive to reflect the changes of soil physical and chemical properties, suggesting that the calcium carbonate buffer system could be further classified as soil active calcium carbonate buffer system.

77 FR 72326 - Endangered Species; File No. 17381

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-05

... Kristen Hart, Ph.D., United States Geological Survey, Southeast Ecological Science Center, 3205 College... for the purposes of scientific research. DATES: Written, telefaxed, or emailed comments must be... continue long-term research on the demographics and movements of green, loggerhead, hawksbill, and Kemp's...

Effects of long-term drainage on microbial community composition vary between peatland types

NASA Astrophysics Data System (ADS)

Urbanová, Zuzana; Barta, Jiri

2016-04-01

Peatlands represent an important reservoir of carbon, but their functioning can be threatened by water level drawdown caused by climate or land use change. Knowledge of how microbial communities respond to long-term drainage in different peatland types could help improve predictions of the effect of climate change on these ecosystems. We investigated the effect of long-term drainage on microbial community composition in bog, fen and spruce swamp forests (SSF) in the Sumava Mountains (Czech Republic), using high-throughput barcoded sequencing, in relation to peat biochemical properties. Longterm drainage had substantial effects, which depended strongly on peatland type, on peat biochemical properties and microbial community composition. The effect of drainage was most apparent on fen, followed by SSF, and lowest on bog. Long-term drainage led to lower pH, reduced peat decomposability and increased bulk density, which was reflected by reduced microbial activity. Bacterial diversity decreased and Acidobacteria became the dominant phylum on drained sites, reflecting a convergence in bacterial community composition across peatlands after long-term drainage. The archaeal communities changed very strongly and became similar across drained peatlands. Overall, the characteristic differences between distinct peatland types under natural conditions were diminished by long-term drainage. Bog represented a relatively resilient system while fen seemed to be very sensitive to environmental changes.

Effect of pH on H2O2 production in the radiolysis of water.

PubMed

Roth, Olivia; LaVerne, Jay A

2011-02-10

The yields of hydrogen peroxide have been measured in the radiolysis of aqueous solutions of acrylamide, bromide, nitrate, and air in the pH range of 1-13. Hydrogen peroxide is the main stable oxidizing species formed in the radiolysis of water, and its long-term yield is found to be very sensitive to the system used in the measurements. Experiments with γ-irradiation combined with model calculations show that the primary yields of hydrogen peroxide are nearly independent of pH in the range of 2-12. Slightly higher primary yields are suggested at very low pH in particular when O(2) is present, while the yields seem to decrease at very high pH. Irradiations were performed with 5 MeV H ions, 5 MeV He ions, and 10 MeV C ions to evaluate the intratrack and homogeneous kinetic contributions to H(2)O(2) formation with different ions. Many of the trends in hydrogen peroxide yields with pH observed with γ-irradiations are observed with irradiation by the heavy ions. The lower yields of radicals in the homogeneous phase with the heavier ions tend to minimize the effects of radicals on the hydrogen peroxide yields at long times.

Research for Lunar Exploration: ADVANCE Program

NASA Technical Reports Server (NTRS)

Rojdev, Kristina

2009-01-01

This viewgraph presentation reviews the work that the author has been involved with in her undergraduate and graduate education and the ADVANCE Program. One project was the Lunar Entry and Approach Platform For Research On Ground (LEAPFROG). This vehicle was to be a completely autonomous vehicle, and was developed in successive academic years with increases in the perofmamnce and capability of the simulated lander. Another research project for the PhD was on long-term lunar radiation degradation of materials to be used for construction of lunar habitats. This research has concentrated on developing and testing light-weight composite materials with high strength characteristics, and the ability of these composite materials to withstand the lunar radiation environment.

Oral manifestations in gastroesophageal reflux disease.

PubMed

Preetha, A; Sujatha, D; Patil, Bharathi A; Hegde, Sushmini

2015-01-01

Many systemic diseases exert their influence on oral health. Among these, gastroesophageal reflux disease (GERD) is the most common. In this study, 100 patients who were previously diagnosed with GERD were examined following a 12-hour fast and evaluated in terms of the severity (grade) of the disease as well as any oral, dental, and/or salivary pH changes. Results found 11 patients with tooth erosion. These patients were older, and their average mean duration of GERD was longer in comparison to those without erosion. There was an inverse relationship between salivary pH and the GERD duration and grade of severity. As the GERD grade increased, the severity of tooth erosion increased. Patients with erosion also exhibited oral mucosal changes. Thus severe, long-term GERD was found to be potentially detrimental to oral soft tissues, dental structures, and salivary pH, whereas milder forms of the disease did not necessarily cause dental side effects.

Teaching Engineering Ethics to PhD Students: A Berkeley-Delft Initiative : Commentary on "Ethics Across the Curriculum: Prospects for Broader (and Deeper) Teaching and Learning in Research and Engineering Ethics".

PubMed

Taebi, Behnam; Kastenberg, William E

2016-07-13

A joint effort by the University of California at Berkeley and Delft University of Technology to develop a graduate engineering ethics course for PhD students encountered two types of challenges: academic and institutional. Academically, long-term collaborative research efforts between engineering and philosophy faculty members might be needed before successful engineering ethics courses can be initiated; the teaching of ethics to engineering graduate students and collaborative research need to go hand-in-hand. Institutionally, both bottom-up approaches at the level of the faculty and as a joint research and teaching effort, and top-down approaches that include recognition by a University's administration and the top level of education management, are needed for successful and sustainable efforts to teach engineering ethics.

GERD: Diagnosing and treating the burn.

PubMed

Alzubaidi, Mohammed; Gabbard, Scott

2015-10-01

Gastroesophageal reflux disease (GERD) is chronic, very common, and frequently encountered in internal medicine and subspecialty clinics. It is often diagnosed on clinical grounds, but specialized testing such as endoscopy and pH monitoring may be necessary in certain patients. Although proton pump inhibitors (PPIs) are the mainstay of treatment, clinicians should be aware of their short-term and long-term side effects. Copyright © 2015 Cleveland Clinic.

Modelling study of soil C, N and pH response to air pollution and climate change using European LTER site observations.

PubMed

Holmberg, Maria; Aherne, Julian; Austnes, Kari; Beloica, Jelena; De Marco, Alessandra; Dirnböck, Thomas; Fornasier, Maria Francesca; Goergen, Klaus; Futter, Martyn; Lindroos, Antti-Jussi; Krám, Pavel; Neirynck, Johan; Nieminen, Tiina Maileena; Pecka, Tomasz; Posch, Maximilian; Pröll, Gisela; Rowe, Ed C; Scheuschner, Thomas; Schlutow, Angela; Valinia, Salar; Forsius, Martin

2018-05-31

Current climate warming is expected to continue in coming decades, whereas high N deposition may stabilize, in contrast to the clear decrease in S deposition. These pressures have distinctive regional patterns and their resulting impact on soil conditions is modified by local site characteristics. We have applied the VSD+ soil dynamic model to study impacts of deposition and climate change on soil properties, using MetHyd and GrowUp as pre-processors to provide input to VSD+. The single-layer soil model VSD+ accounts for processes of organic C and N turnover, as well as charge and mass balances of elements, cation exchange and base cation weathering. We calibrated VSD+ at 26 ecosystem study sites throughout Europe using observed conditions, and simulated key soil properties: soil solution pH (pH), soil base saturation (BS) and soil organic carbon and nitrogen ratio (C:N) under projected deposition of N and S, and climate warming until 2100. The sites are forested, located in the Mediterranean, forested alpine, Atlantic, continental and boreal regions. They represent the long-term ecological research (LTER) Europe network, including sites of the ICP Forests and ICP Integrated Monitoring (IM) programmes under the UNECE Convention on Long-range Transboundary Air Pollution (LRTAP), providing high quality long-term data on ecosystem response. Simulated future soil conditions improved under projected decrease in deposition and current climate conditions: higher pH, BS and C:N at 21, 16 and 12 of the sites, respectively. When climate change was included in the scenario analysis, the variability of the results increased. Climate warming resulted in higher simulated pH in most cases, and higher BS and C:N in roughly half of the cases. Especially the increase in C:N was more marked with climate warming. The study illustrates the value of LTER sites for applying models to predict soil responses to multiple environmental changes. Copyright © 2017 Elsevier B.V. All rights reserved.

Regional Monitoring of Acidic Lakes and Streams

EPA Pesticide Factsheets

This asset provides data on the acid-base status of lakes and streams. Key chemical indicators measured include: sulfate, nitrate, ammonium, chloride, Acid Neutralizing Capacity (ANC), pH, base cations, dissolved organic carbon (DOC), total aluminum. TIME and LTM are part of EPA's Environmental Monitoring and Assessment Program (EMAP). Long-term monitoring of the acid-base status (pH, ANC, SO4, NO3, NH4, DOC, base cations, Al) in lakes and streams. Monitoring is conducted in acid sensitive regions of the Eastern U.S.

Role of Acidophilic Methanotrophs in Long Term Natural Attenuation of cVOCs in Low pH Aquifers

DTIC Science & Technology

2017-06-15

well was < 0.2 mg/L, although the ORP was slightly oxidizing at +131 mV. The pH was ~4.4 in the microcosms (data not shown). Oxygen consumption was...significant losses of methane were observed in the live or killed samples over 5 weeks, despite the continuing oxygen consumption (Figure 15). Based on...15% (Figure 22). There was significant oxygen consumption in all samples over the first day of incubation, with headspace concentrations dropping to

Long-term conversion of 45S5 bioactive glass-ceramic microspheres in aqueous phosphate solution.

PubMed

Fu, Hailuo; Rahaman, Mohamed N; Day, Delbert E; Huang, Wenhai

2012-05-01

The conversion of 45S5 glass and glass-ceramics to a hydroxyapatite (HA)-like material in vitro has been studied extensively, but only for short reaction times (typically <3 months). In this paper, we report for the first time on the long-term conversion of 45S5 glass-ceramic microspheres (designated 45S5c) in an aqueous phosphate solution. Microspheres of 45S5c (75-150 μm) were immersed for 10 years at room temperature (~25 °C) in K(2)HPO(4) solution with a concentration of 0.01 M or 1.0 M, and with a starting pH of 7.0 or 9.5. The reacted 45S5c microspheres and solutions were analyzed using structural and analytical techniques. Only 25-45 vol% of the 45S5c microspheres were converted to an HA-like material after the 10 year reaction. In solutions with a starting pH of 9.5, an increase in the K(2)HPO(4) concentration from 0.01 to 1.0 M resulted in a doubling of the volume of the microspheres converted to an HA-like material but had little effect on the composition of the HA-like product. In comparison, reaction of the 45S5c microspheres in the solution with a starting pH of 7.0 resulted in an HA-like product in the 0.01 M K(2)HPO(4) solution but a calcium pyrophosphate product, Ca(10)K(4)(P(2)O(7))(6).9H(2)O, in the 1.0 M solution. The consequences of these results for the long-term use of 45S5 glass-ceramics in biomedical applications are discussed.

Long-term statin therapy could be efficacious in reducing the lipoprotein (a) levels in patients with coronary artery disease modified by some traditional risk factors.

PubMed

Xu, Ming-Xing; Liu, Chang; He, Yong-Ming; Yang, Xiang-Jun; Zhao, Xin

2017-05-01

Lipoprotein (a) [Lp (a)] is a well-established risk factor for coronary artery disease (CAD). However, up till now, treatment of patients with higher Lp (a) levels is challenging. This current study aimed to investigate the therapeutic effects of short-, medium and long-term statin use on the Lp (a) reduction and its modifying factors. The therapeutic duration was categorized into short-term (median, 39 days), medium term (median, 219 days) and long-term (median, 677 days). The lipid profiles before therapy served as baselines. Patients at short-, medium or long-term exactly matched with those at baseline. Every patient's lipid profiles during the follow-ups were compared to his own ones at baselines. The current study demonstrated that long-term statin therapy significantly decreased the Lp (a) levels in CAD patients while short-term or medium term statin therapy didn't. When grouped by statin use, only long-term simvastatin use significantly decreased the Lp (a) levels while long-term atorvastatin use insignificantly decreased the Lp (a) levels. Primary hypertension (PH), DM, low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) could modify the therapeutic effects of statin use on the Lp (a) levels in CAD patients. The long-term statin therapy could be efficacious in reducing the Lp (a) levels in CAD patients, which has been modified by some traditional risk factors. In the era of commercial unavailability of more reliable Lp (a) lowering drugs, our findings will bolster confidence in fighting higher Lp (a) abnormalities both for patients and for doctors.

Review of National Work Programme on the Long Term Effects of Sustained High G on the Cervical Spine (Analyse du programme de travail national : les effets long terme sur la colonne cervicale d’un nombre de G lev et prolong )

DTIC Science & Technology

2008-12-01

Prof. Karin Harms-Ringdahl, PhD, RPT Karolinska Institutet Department of Neurobiology, Care Sciences, and Society Division of Physiotherapy 23100...Äng Karolinska Institutet Department of Neurobiology, Care Sciences, and Society Division of Physiotherapy Alfred Nobels Allé 23100 SE-14183...report is in preparation. The RAF has an ongoing project (from August 2006 to September 2007) determining the need for physiotherapy for aircrew on the

A workshop on leadership for senior MD–PhD students

PubMed Central

Meador, Catherine B.; Parang, Bobak; Musser, Melissa A.; Haliyur, Rachana; Owens, David A.; Dermody, Terence S.

2016-01-01

Leadership skills are essential for a successful career as a physician-scientist, yet many MD–PhD training programs do not offer formal training in leadership. The Vanderbilt Medical Scientist Training Program (MSTP) previously established a 2-day leadership workshop that has been held biennially since 2006 for students in the first and second years of the graduate school portion of combined MD and PhD training (G1/G2 students). Workshop attendees have consistently rated this workshop as a highly effective experience. However, opportunities for structured training in leadership competencies during the subsequent 3–5 years of MD–PhD training are limited. Given the success of the G1/G2 leadership workshop and the need for continuity in this model of leadership training, we developed a half-day workshop for MSTP students in the clinical years of medical school (M3/M4 students) to foster continued training in leadership. Our workshop curriculum, based in part on original cases drafted by Vanderbilt MSTP students, provides concrete strategies to manage conflict and navigate leadership transitions in the physician-scientist career path. The curriculum emphasizes both short-term competencies, such as effective participation as a member of a clinical team, and long-term competencies, such as leadership of a research team, division, or department. Our inaugural senior leadership workshop, held in August, 2015, was judged by student participants to be well organized and highly relevant to leadership concepts and skills. It will be offered biennially in our training curriculum for M3 and M4 MSTP students. PMID:27499363

A workshop on leadership for senior MD-PhD students.

PubMed

Meador, Catherine B; Parang, Bobak; Musser, Melissa A; Haliyur, Rachana; Owens, David A; Dermody, Terence S

2016-01-01

Leadership skills are essential for a successful career as a physician-scientist, yet many MD-PhD training programs do not offer formal training in leadership. The Vanderbilt Medical Scientist Training Program (MSTP) previously established a 2-day leadership workshop that has been held biennially since 2006 for students in the first and second years of the graduate school portion of combined MD and PhD training (G1/G2 students). Workshop attendees have consistently rated this workshop as a highly effective experience. However, opportunities for structured training in leadership competencies during the subsequent 3-5 years of MD-PhD training are limited. Given the success of the G1/G2 leadership workshop and the need for continuity in this model of leadership training, we developed a half-day workshop for MSTP students in the clinical years of medical school (M3/M4 students) to foster continued training in leadership. Our workshop curriculum, based in part on original cases drafted by Vanderbilt MSTP students, provides concrete strategies to manage conflict and navigate leadership transitions in the physician-scientist career path. The curriculum emphasizes both short-term competencies, such as effective participation as a member of a clinical team, and long-term competencies, such as leadership of a research team, division, or department. Our inaugural senior leadership workshop, held in August, 2015, was judged by student participants to be well organized and highly relevant to leadership concepts and skills. It will be offered biennially in our training curriculum for M3 and M4 MSTP students.

Comparison between Fluoride and Nano-hydroxyapatite in Remineralizing Initial Enamel Lesion: An in vitro Study.

PubMed

Daas, Issa; Badr, Sherine; Osman, Essam

2018-03-01

The aim of this study was to compare the effectiveness of nano-hydroxyapatite (nano-HAP) paste and fluoride varnish in remineralizing initial enamel lesion in young permanent teeth and their ability to resist secondary caries under dynamic pH cycling quantitatively and qualitatively. Initial caries-like lesions were artificially developed on 45 specimens. Specimens were divided into three groups: (1) Control (without treatment), (2) fluoride varnish (3M ESPE), and (3) nano-HAP paste (Desensibilize Nano P). The nano-HAP paste was applied twice separated by one pH cycle, and the varnish was applied only once followed by 7 days of pH cycling. All specimens were examined using DIAGNOdent® pen (KaVo, Germany), and a representative specimen was randomly selected from each group for qualitative evaluation using scanning electron microscope (SEM) at four stages: Baseline, after lesion formation, immediately after remineralization, and after pH cycling. Data were statistically analyzed with Statistical Package for the Social Sciences (SPSS), version 20. The degree of demineralization was significantly elevated in control group; however, no significant difference was found between fluoride varnish group and nano-HAP paste group (p < 0.001). Nano-HAP paste showed promising long-term protective effect in terms of surface depositions and maintaining a smooth surface compared with fluoride varnish. Based on the findings of this study, nano-HAP paste might be recommended as alternative remineralizing agent with lower fluoride concentration than fluoride varnish that could be beneficial for children, pregnant females, and those who are at high risk of dental fluorosis.

[Biocompatibility of peritoneal dialysis fluids].

PubMed

Boulanger, Eric; Moranne, Olivier; Wautier, Marie-Paule; Rougier, Jean-Phillipe; Ronco, Pierre; Pagniez, Dominique; Wautier, Jean-Luc

2005-03-01

Repeated and long-term exposure to conventional glucose-based peritoneal dialysis fluids (PDFs) with poor biocompatibility plays a central role in the pathogenesis of the functional and structural changes of the peritoneal membrane. We have used immortalized human peritoneal mesothelial cells in culture to assess in vitro the biocompatibility of PDFs. Low pH, high glucose concentration and heat sterilization represent major factors of low biocompatibility. Two recent groups of glucose derivatives have been described. Glucose degradation products (GDPs) are formed during heat sterilization (glycoxidation) and storage. GDPs can bind protein and form AGEs (Advanced Glycation End-products), which can also result from the binding of glucose to free NH2 residues of proteins (glycation). The physiological pH, and the separation of glucose during heat sterilization (low GDP content) in the most recent PDFs dramatically increase the biocompatibility. The choice of PD programs with high biocompatibility PDFs allows preserving the function of the peritoneal membrane. Improvement of PDF biocompatibility may limit the occurrence of chronic chemical peritonitis and may allow long-term PD treatment.

Long-term trends and variation of acidity, COD(Mn) and colour in coastal rivers of Western Finland in relation to climate and hydrology.

PubMed

Saarinen, Tuomas; Vuori, Kari-Matti; Alasaarela, Erkki; Kløve, Bjørn

2010-10-01

High acidity caused by geochemical processes and intensive land use of acid sulphate (AS) soils have continuously degraded the status of water bodies in Western Finland. Despite this, research on the long-term pattern and dynamics of acidification in rivers affected by acid sulphate soils is scarce. This study examined changes in alkalinity and pH value during the period 1913-2007 in nine large Finnish rivers discharging into the Gulf of Bothnia. In addition, patterns of COD(Mn) and colour were analysed during the period 1961-2007. Relationships between pH, alkalinity, COD(Mn) and colour and climate variables were also studied. In four rivers with no AS soil impact (Kokemäenjoki, Kemijoki, Iijoki and Oulujoki), critically low pH levels did not occur during the study period, whereas three rivers exposed to minor or moderate levels of runoff from AS soils (Lestijoki, Kalajoki, and Siikajoki) had all periods with critically low pH and alkalinity. The most severe acidity problems occurred in the rivers Kyrönjoki and Lapuanjoki, with extensive drainage of AS soils being the main reason for the low pH status. Maximum discharge was clearly related to the acidity status of many rivers during the autumn-winter runoff period, when a significant negative linear correlation was found between maximum discharge and minimum pH in the rivers affected by AS soils. There was also a more distinct relationship between maximum chemical oxygen demand (COD(Mn)) and minimum pH in autumn runoff than in spring. COD(Mn) levels significantly increased with increasing discharge in the rivers with no or minor AS soil impact. Climate change is predicted to increase river flow in general and winter discharge in particular, and therefore the acidity problems in affected rivers may increase in a future climate. Copyright 2010 Elsevier B.V. All rights reserved.

Development and validation of a liquid chromatographic method for the simultaneous determination of aniracetam and its related substances in the bulk drug and a tablet formulation.

PubMed

Papandreou, Georgios; Zorpas, Kostas; Archontaki, Helen

2011-11-01

Simultaneous determination of aniracetam and its related impurities (2-pyrrolidinone, p-anisic acid, 4-p-anisamidobutyric acid and (p-anisoyl)-4-methyl-2-pyrrolidinone) was accomplished in the bulk drug and in a tablet formulation using a high performance liquid chromatographic method with UV detection. Separation was achieved on a Hypersil BDS-CN column (150 mm × 4.0 mm, 5 μm) using a gradient elution program with solvent A composed of phosphate buffer (pH 4.0; 0.010 M) and solvent B of acetonitrile-phosphate buffer (pH 4.0; 0.010 M) (90:10, v/v). The flow rate of the mobile phase was 1.0 mL min(-1) and the total elution time, including the column re-equilibration, was approximately 20 min. The UV detection wavelength was varied appropriately among 210, 250 and 280 nm. Injection volume was 20 μL and experiments were conducted at ambient temperature. The developed method was validated in terms of system suitability, selectivity, linearity, range, precision, accuracy, limits of detection and quantification for the impurities, short term and long term stability of the analytes in the prepared solutions and robustness, following the ICH guidelines. Therefore, the proposed method was suitable for the simultaneous determination of aniracetam and its studied related impurities. Copyright © 2011 Elsevier B.V. All rights reserved.

The impact of additional cytogenetic abnormalities at diagnosis and during therapy with tyrosine kinase inhibitors in Chronic Myeloid Leukaemia.

PubMed

Crisan, A M; Coriu, D; Arion, C; Colita, A; Jardan, C

2015-01-01

Chronic Myeloid Leukemia's (CML) treatment was optimized since the development of tyrosine kinase inhibitors (TKI) and an increased overall survival during TKI was noticed. During the TKI era, protocols for assessing response and resistance to treatment were developed. Additional chromosomal abnormalities (ACAs) are strongly associated with disease progression but their prognostic impact and influence on treatment response are yet to be defined. The aim of this study was to analyze the impact of ACAs on time to achieve complete cytogenetic response (CCyR), treatment and overall survival. Since 2005 until 2013, the data from the Hematology and Bone Marrow Transplantation Department of Fundeni Clinical Institute was collected. In this observational retrospective single centre study, 28 CML patients with ACAs at diagnosis and during TKI treatment were included. From ACAs at diagnosis group, the most frequent major route ACAs were trisomy 8, trisomy 19 and second Philadelphia (Ph) chromosome and the most frequent minor route ACAs were monosomies and structural abnormalities (inversions and translocations). From the ACAs during the TKI group, the most frequent major route cytogenetic abnormalities in Ph positive and negative cells were trisomy 8, trisomy 19 and second Ph chromosome and the most frequent minor route cytogenetic abnormalities in Ph positive and negative cells were marker chromosomes and structural abnormalities (inversions, translocations and dicentric chromosomes). In both groups, the time to CCyR was longer and long-term results were inferior in comparison with standard patients but the differences were not significant and in accordance to published data. The 12 months follow-up after the study's end showed that 26 patients were alive and in long-term CCyR and 2 deaths were reported. CML = Chronic Myeloid Leukemia, BCR-ABL1 = Break Cluster Region - Abelson gene, TKI = tyrosine kinase inhibitor treatment, ACAs = additional cytogenetic abnormalities, CCyR = complete cytogenetic response, PCyR = partial cytogenetic response, mCyR = minor cytogenetic response, MMR = major molecular response, HSCT = hematopoietic stem cell transplant, HLA = human leukocyte antigens, CP = chronic phase, AP = accelerated phase, BP = blast phase, OS = overall survival, CBA = chromosome banding analysis, +8 = trisomy 8, i(17q) = isochromosome (17q), +Ph = second Philadelphia chromosome, -7 = monosomy 7, -17 = monosomy 17, +17 = trisomy 17, -21 = monosomy 21, +21 = trisomy 21, -Y = loss of Y chromosome, ELN = European LeukemiaNet, IMA600 = Imatinib 600 mg daily, IMA400 = Imatinib 400 mg daily, NILO600 = Nilotinib 600 mg daily, DASA100 = Dasatinib 100mg daily, DASA140 = Dasatinib 140 mg daily.

Sub-optimal pH Preadaptation Improves the Survival of Lactobacillus plantarum Strains and the Malic Acid Consumption in Wine-Like Medium

PubMed Central

Succi, Mariantonietta; Pannella, Gianfranco; Tremonte, Patrizio; Tipaldi, Luca; Coppola, Raffaele; Iorizzo, Massimo; Lombardi, Silvia Jane; Sorrentino, Elena

2017-01-01

Forty-two oenological strains of Lb. plantarum were assessed for their response to ethanol and pH values generally encountered in wines. Strains showed a higher variability in the survival when exposed to low pH (3.5 or 3.0) than when exposed to ethanol (10 or 14%). The study allowed to individuate the highest ethanol concentration (8%) and the lowest pH value (4.0) for the growth of strains, even if the maximum specific growth rate (μmax) resulted significantly reduced by these conditions. Two strains (GT1 and LT11) preadapted to 2% ethanol and cultured up to 14% of ethanol showed a higher growth than those non-preadapted when they were cultivated at 8% of ethanol. The evaluation of the same strains preadapted to low pH values (5.0 and 4.0) and then grown at pH 3.5 or 3.0 showed only for GT1 a sensitive μmax increment when it was cultivated in MRS at pH 3 after a preadaptation to pH 5.0. The survival of GT1 and LT11 was evaluated in Ringer's solution at 14% ethanol after a long-term adaptation in MRS with 2% ethanol or in MRS with 2% ethanol acidified at pH 5.0 (both conditions, BC). Analogously, the survival was evaluated at pH 3.5 after a long-term adaptation in MRS at pH 5.0 or in MRS BC. The impact of the physiologic state (exponential phase vs stationary phase) on the survival was also evaluated. Preadapted cells showed the same behavior of non-preadapted cells only when cultures were recovered in the stationary phase. Mathematical functions were individuated for the description of the survival of GT1 and LT11 in MRS at 14% ethanol or at pH 3.5. Finally, a synthetic wine (SW) was used to assess the behavior of Lb. plantarum GT1 and LT11 preadapted in MRS at 2% ethanol or at pH 5.0 or in BC. Only GT1 preadapted to pH 5.0 and collected in the stationary phase showed constant values of microbial counts after incubation for 15 days at 20°C. In addition, after 15 days the L-malic acid resulted completely degraded and the pH value increased of about 0.3 units. PMID:28382030

Bluetooth technology for prevention of dental caries.

PubMed

Kolahi, Jafar; Fazilati, Mohamad

2009-12-01

Caries is caused when the pH at the tooth surface drops below 5.5. A miniaturized and autonomous pH monitoring nodes can be attached to the tooth surface, like a tooth jewel. This intelligent sensor includes three components: (a) digital micro pH meter, (b) power supply, (c) wireless communicating device. The micro pH meter facilitates long term tooth surface pH monitoring and providing real time feedback to the patients and dental experts. Power supply of this system will be microfabricated biocatalytic fuel cell (enzymatic micro-battery) using organic compounds (e.g. formate or glucose) as the fuel to generate electricity. When micro pH meter detects the pH lower than 5.5, wireless Bluetooth device sends a caution (e.g. "you are at risk of dental caries") to external monitoring equipment such as mobile phone or a hands-free heads. After reception of the caution, subjects should use routine brushing and flossing procedure or use a medicated chewing gum (e.g. chlorhexidine containing chewing gum) or rinse with a mouthwash.

Sulphursoil - Delano Development Corporation

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1985-06-01

A sizable amount of technical information has been accumulated on the effects of agricultural applications of the natural mineral product called Sul-Fe. This technical information supports the field observations of farmers, landscapers and gardeners who have used the product. Sul-Fe is often evaluated in terms of its sulphur content alone. When compared to elemental sulphur (100% sulphur), the 18 to 21% sulphur content of Sul-Fe seems relatively low. However, as the following technical data indicates, when judged on actual effects, Sul-Fe's complex mixture of minerals has several advantages over elemental sulphur. When judged on the basis of soil acidulation, Sul-Femore » has more immediate effects than elemental sulphur. The rapid acidifying effect is due to Sul-Fe's content of crystalline sulphuric acid. Sul-Fe also has long-term effects on soil pH due to its content of sulphur and sulfides and the time required to oxidize these materials. Elemental sulphur contains sulphur in only one chemical form which must be microbially oxidized before it becomes reactive in the soil solution, a reaction that takes quite some time in some soils. Sul-Fe is thus better than elemental sulphur in terms of immediate effects and comparable in terms of long term effects. Applied blends of Sul-Fe supplemented with elemental sulphur may provide for a maximization of both short and long term effects. An additional benefit derived from the use of Sul-Fe is the addition to the soil of a variety of trace nutrients including iron, calcium, zinc, copper, manganese, magnesium, and molybdenum.« less

Flexible pH-Sensing Hydrogel Fibers for Epidermal Applications.

PubMed

Tamayol, Ali; Akbari, Mohsen; Zilberman, Yael; Comotto, Mattia; Lesha, Emal; Serex, Ludovic; Bagherifard, Sara; Chen, Yu; Fu, Guoqing; Ameri, Shideh Kabiri; Ruan, Weitong; Miller, Eric L; Dokmeci, Mehmet R; Sonkusale, Sameer; Khademhosseini, Ali

2016-03-01

Epidermal pH is an indication of the skin's physiological condition. For example, pH of wound can be correlated to angiogenesis, protease activity, bacterial infection, etc. Chronic nonhealing wounds are known to have an elevated alkaline environment, while healing process occurs more readily in an acidic environment. Thus, dermal patches capable of continuous pH measurement can be used as point-of-care systems for monitoring skin disorder and the wound healing process. Here, pH-responsive hydrogel fibers are presented that can be used for long-term monitoring of epidermal wound condition. pH-responsive dyes are loaded into mesoporous microparticles and incorporated into hydrogel fibers using a microfluidic spinning system. The fabricated pH-responsive microfibers are flexible and can create conformal contact with skin. The response of pH-sensitive fibers with different compositions and thicknesses are characterized. The suggested technique is scalable and can be used to fabricate hydrogel-based wound dressings with clinically relevant dimensions. Images of the pH-sensing fibers during real-time pH measurement can be captured with a smart phone camera for convenient readout on-site. Through image processing, a quantitative pH map of the hydrogel fibers and the underlying tissue can be extracted. The developed skin dressing can act as a point-of-care device for monitoring the wound healing process. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Epimural bacterial community structure in the rumen of Holstein cows with different responses to a long-term subacute ruminal acidosis diet challenge.

PubMed

Wetzels, S U; Mann, E; Pourazad, P; Qumar, M; Pinior, B; Metzler-Zebeli, B U; Wagner, M; Schmitz-Esser, S; Zebeli, Q

2017-03-01

Subacute ruminal acidosis (SARA) is a prevalent metabolic disorder in cattle, characterized by intermittent drops in ruminal pH. This study investigated the effect of a gradual adaptation and continuously induced long-term SARA challenge diet on the epimural bacterial community structure in the rumen of cows. Eight rumen-cannulated nonlactating Holstein cows were transitioned over 1 wk from a forage-based baseline feeding diet (grass silage-hay mix) to a SARA challenge diet, which they were fed for 4 wk. The SARA challenge diet consisted of 60% concentrates (dry matter basis) and 40% grass silage-hay mix. Rumen papillae biopsies were taken at the baseline, on the last day of the 1-wk adaptation, and on the last day of the 4-wk SARA challenge period; ruminal pH was measured using wireless sensors. We isolated DNA from papillae samples for 16S rRNA gene amplicon sequencing using Illumina MiSeq. Sequencing results of most abundant key phylotypes were confirmed by quantitative PCR. Although they were fed similar amounts of concentrate, cows responded differently in terms of ruminal pH during the SARA feeding challenge. Cows were therefore classified as responders (n = 4) and nonresponders (n = 4): only responders met the SARA criterion of a ruminal pH drop below 5.8 for longer than 330 min/d. Data showed that Proteobacteria, Firmicutes, and Bacteroidetes were the most abundant phyla, and at genus level, Campylobacter and Kingella showed highest relative abundance, at 15.5 and 7.8%, respectively. Diversity analyses revealed a significant increase of diversity after the 1-wk adaptation but a decrease of diversity and species richness after the 4-wk SARA feeding challenge, although without distinction between responders and nonresponders. At the level of the operational taxonomic unit, we detected diet-specific shifts in epimural community structure, but in the overall epimural bacterial community structure, we found no differences between responders and nonresponders. Correlation analysis revealed significant associations between grain intake and operational taxonomic unit abundance. The study revealed major shifts in the 3 dominating phyla and, most importantly, a loss of diversity in the epimural bacterial communities during a long-term SARA diet challenge, in which 60% concentrate supply for 4 wk was instrumental rather than the magnitude of the drop of ruminal pH below 5.8. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Toward Standardizing a Lexicon of Infectious Disease Modeling Terms.

PubMed

Milwid, Rachael; Steriu, Andreea; Arino, Julien; Heffernan, Jane; Hyder, Ayaz; Schanzer, Dena; Gardner, Emma; Haworth-Brockman, Margaret; Isfeld-Kiely, Harpa; Langley, Joanne M; Moghadas, Seyed M

2016-01-01

Disease modeling is increasingly being used to evaluate the effect of health intervention strategies, particularly for infectious diseases. However, the utility and application of such models are hampered by the inconsistent use of infectious disease modeling terms between and within disciplines. We sought to standardize the lexicon of infectious disease modeling terms and develop a glossary of terms commonly used in describing models' assumptions, parameters, variables, and outcomes. We combined a comprehensive literature review of relevant terms with an online forum discussion in a virtual community of practice, mod4PH (Modeling for Public Health). Using a convergent discussion process and consensus amongst the members of mod4PH, a glossary of terms was developed as an online resource. We anticipate that the glossary will improve inter- and intradisciplinary communication and will result in a greater uptake and understanding of disease modeling outcomes in heath policy decision-making. We highlight the role of the mod4PH community of practice and the methodologies used in this endeavor to link theory, policy, and practice in the public health domain.

Toward Standardizing a Lexicon of Infectious Disease Modeling Terms

PubMed Central

Milwid, Rachael; Steriu, Andreea; Arino, Julien; Heffernan, Jane; Hyder, Ayaz; Schanzer, Dena; Gardner, Emma; Haworth-Brockman, Margaret; Isfeld-Kiely, Harpa; Langley, Joanne M.; Moghadas, Seyed M.

2016-01-01

Disease modeling is increasingly being used to evaluate the effect of health intervention strategies, particularly for infectious diseases. However, the utility and application of such models are hampered by the inconsistent use of infectious disease modeling terms between and within disciplines. We sought to standardize the lexicon of infectious disease modeling terms and develop a glossary of terms commonly used in describing models’ assumptions, parameters, variables, and outcomes. We combined a comprehensive literature review of relevant terms with an online forum discussion in a virtual community of practice, mod4PH (Modeling for Public Health). Using a convergent discussion process and consensus amongst the members of mod4PH, a glossary of terms was developed as an online resource. We anticipate that the glossary will improve inter- and intradisciplinary communication and will result in a greater uptake and understanding of disease modeling outcomes in heath policy decision-making. We highlight the role of the mod4PH community of practice and the methodologies used in this endeavor to link theory, policy, and practice in the public health domain. PMID:27734014

Long-term dentin remineralization by poly(amido amine) and rechargeable calcium phosphate nanocomposite after fluid challenges.

PubMed

Liang, Kunneng; Xiao, Shimeng; Wu, Junling; Li, Jiyao; Weir, Michael D; Cheng, Lei; Reynolds, Mark A; Zhou, Xuedong; Xu, Hockin H K

2018-04-01

Previous studies investigated short-term dentin remineralization; studies on long-term dentin remineralization after fluid challenges mimicking fluids in oral environment are lacking. The objective of this study was to develop a long-term remineralization method to via poly(amido amine) (PAMAM) and rechargeable composite containing nanoparticles of amorphous calcium phosphate (NACP) after fluid challenges for the first time. NACP composite was immersed at pH 4 to exhaust its calcium (Ca) and phosphate (P) ions, and then recharged with Ca and P ions, to test the remineralization of the exhausted and recharged NACP composite. Dentin was acid-etched with 37% phosphoric acid. Four groups were prepared: (1) dentin control, (2) dentin with PAMAM, (3) dentin with the recharged NACP composite, and (4) dentin with PAMAM plus recharged NACP composite. PAMAM-coated dentin was immersed in phosphate-buffered saline with shaking for 72 days, because there is fluid flow in the mouth which could potentially detach the PAMAM from dentin. Specimens were treated with a cyclic artificial saliva/lactic acid regimen for 35 days. After 72days of immersion plus shaking, the PAMAM still successfully fulfilled its mineralization nucleation. The recharged NACP composite still provided acid-neutralization and ion re-release, which did not decrease with increasing the number of recharge cycles. The immersed-PAMAM plus NACP achieved complete dentin remineralization and restored the hardness to that of healthy dentin. In conclusion, superior long-term remineralization of the PAMAM plus NACP method was demonstrated for the first time. The immersed-PAMAM plus recharged NACP completely remineralized the pre-demineralized dentin, even after prolonged fluid-challenge similar to that in oral environment. The novel PAMAM plus NACP composite method is promising to provide long-term tooth protection and caries inhibition. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

The Effect of Long-Term Continuous Cropping of Black Pepper on Soil Bacterial Communities as Determined by 454 Pyrosequencing.

PubMed

Xiong, Wu; Li, Zhigang; Liu, Hongjun; Xue, Chao; Zhang, Ruifu; Wu, Huasong; Li, Rong; Shen, Qirong

2015-01-01

In the present study, 3 replanted black pepper orchards with continuously cropping histories for 10, 21, and 55 years in tropical China, were selected for investigating the effect of monoculture on soil physiochemical properties, enzyme activities, bacterial abundance, and bacterial community structures. Results showed long-term continuous cropping led to a significant decline in soil pH, organic matter contents, enzymatic activities, and resulted in a decrease in soil bacterial abundance. 454 pyrosequencing analysis of 16S rRNA genes revealed that the Acidobacteria and Proteobacteria were the main phyla in the replanted black pepper orchard soils, comprising up to 73.82% of the total sequences; the relative abundances of Bacteroidetes and Firmicutes phyla decreased with long-term continuous cropping; and at genus level, the Pseudomonas abundance significantly depleted after 21 years continuous cropping. In addition, bacterial diversity significantly decreased after 55 years black pepper continuous cropping; obvious variations for community structures across the 3 time-scale replanted black pepper orchards were observed, suggesting monoculture duration was the major determinant for bacterial community structure. Overall, continuous cropping during black pepper cultivation led to a significant decline in soil pH, organic matter contents, enzymatic activities, resulted a decrease in soil bacterial abundance, and altered soil microbial community membership and structure, which in turn resulted in black pepper poor growth in the continuous cropping system.

The Effect of Long-Term Continuous Cropping of Black Pepper on Soil Bacterial Communities as Determined by 454 Pyrosequencing

PubMed Central

Xiong, Wu; Li, Zhigang; Liu, Hongjun; Xue, Chao; Zhang, Ruifu; Wu, Huasong; Li, Rong; Shen, Qirong

2015-01-01

In the present study, 3 replanted black pepper orchards with continuously cropping histories for 10, 21, and 55 years in tropical China, were selected for investigating the effect of monoculture on soil physiochemical properties, enzyme activities, bacterial abundance, and bacterial community structures. Results showed long-term continuous cropping led to a significant decline in soil pH, organic matter contents, enzymatic activities, and resulted in a decrease in soil bacterial abundance. 454 pyrosequencing analysis of 16S rRNA genes revealed that the Acidobacteria and Proteobacteria were the main phyla in the replanted black pepper orchard soils, comprising up to 73.82% of the total sequences; the relative abundances of Bacteroidetes and Firmicutes phyla decreased with long-term continuous cropping; and at genus level, the Pseudomonas abundance significantly depleted after 21 years continuous cropping. In addition, bacterial diversity significantly decreased after 55 years black pepper continuous cropping; obvious variations for community structures across the 3 time-scale replanted black pepper orchards were observed, suggesting monoculture duration was the major determinant for bacterial community structure. Overall, continuous cropping during black pepper cultivation led to a significant decline in soil pH, organic matter contents, enzymatic activities, resulted a decrease in soil bacterial abundance, and altered soil microbial community membership and structure, which in turn resulted in black pepper poor growth in the continuous cropping system. PMID:26317364

Soil bacterial communities are shaped by temporal and environmental filtering: evidence from a long-term chronosequence.

PubMed

Freedman, Zachary; Zak, Donald R

2015-09-01

Soil microbial communities are abundant, hyper-diverse and mediate global biogeochemical cycles, but we do not yet understand the processes mediating their assembly. Current hypothetical frameworks suggest temporal (e.g. dispersal limitation) and environmental (e.g. soil pH) filters shape microbial community composition; however, there is limited empirical evidence supporting this framework in the hyper-diverse soil environment, particularly at large spatial (i.e. regional to continental) and temporal (i.e. 100 to 1000 years) scales. Here, we present evidence from a long-term chronosequence (4000 years) that temporal and environmental filters do indeed shape soil bacterial community composition. Furthermore, nearly 20 years of environmental monitoring allowed us to control for potentially confounding environmental variation. Soil bacterial communities were phylogenetically distinct across the chronosequence. We determined that temporal and environmental factors accounted for significant portions of bacterial phylogenetic structure using distance-based linear models. Environmental factors together accounted for the majority of phylogenetic structure, namely, soil temperature (19%), pH (17%) and litter carbon:nitrogen (C:N; 17%). However, of all individual factors, time since deglaciation accounted for the greatest proportion of bacterial phylogenetic structure (20%). Taken together, our results provide empirical evidence that temporal and environmental filters act together to structure soil bacterial communities across large spatial and long-term temporal scales. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

Long-term effect of municipal solid waste amendment on microbial abundance and humus-associated enzyme activities under semiarid conditions.

PubMed

Bastida, Felipe; Kandeler, Ellen; Hernández, Teresa; García, Carlos

2008-05-01

Microbial ecology is the key to understanding the function of soil biota for organic matter cycling after a single amendment of organic waste in semiarid soils. Therefore, in this paper, the long-term effect (17 years) of adding different doses of a solid municipal waste to an arid soil on humus-enzyme complexes, a very stable and long-lasting fraction of soil enzymes, as well as on microbial and plant abundance, was studied. Humic substances were extracted by 0.1 M pH 7 sodium pyrophosphate from soil samples collected in experimental plots amended with different doses of a solid municipal waste (0, 65, 130, 195, and 260 t/ha) 17 years before. The activity of different hydrolases related with the C (beta-glucosidase), N (urease), and P (alkaline phosphatase) cycles and with the formation of humic substances (o-diphenol oxidase) were determined in this extract. The density and diversity of plant cover in the plots, as well as the fungal and bacterial biomass (by analyzing phopholipid fatty acids) were also determined. In general, the amended plots showed greater humic substance-related enzymatic activity than the unamended plots. This activity increased with the dose but only up to a certain level, above which it leveled off or even diminished. Plant diversity and cover density followed the same trend. Fungal and bacterial biomass also benefited in a dose-dependent manner. Different signature molecules representing gram+ and gram- bacteria, and those corresponding to monounsaturated and saturated fatty acids showed a similar behavior. The results demonstrate that organic amendment had a noticeable long-term effect on the vegetal development, humic substances-related enzyme activity and on the development of bacteria and fungi in semiarid conditions.

Effect of L-arginine dietary supplementation on salivary urea concentration and pH in physically active individuals.

PubMed

Vuletic, L; Spalj, S; Rogic, D; Ruzic, L; Alajbeg, I

2013-12-01

The aim of this study was to assess if the consumption of 3 g of a commercially available L-arginine dietary supplement causes a postabsorptive rise in urea concentration or pH of unstimulated saliva in a group of physically active individuals. Salivary urea and pH were determined for 117 participants in a randomized double-blinded placebo-controlled study. Samples were collected by 'spitting' method in fasting conditions. One hour prior to their second visit, participants consumed three tablets of L-arginine or placebo. Urea concentration was significantly lower at second measurement for both the study and control group. The magnitude of the change was not significant between the groups. pH was higher for both groups at second measurement, but only significant for the study group. The magnitude of the change was significant between the groups. Participants who intermittently ingested protein dietary supplements and those with a Body Mass Index (BMI) higher than 25 had significantly higher basal urea concentration. The results of this study did not confirm the hypothesis. Further studies are needed to determine the effects of different doses of L-arginine supplements on the biochemical composition of saliva and the influence of their long-term consumption on the risk of developing dental diseases. © 2013 Australian Dental Association.

The effects of pH and pCO2 on photosynthesis and respiration in the diatom Thalassiosira weissflogii.

PubMed

Goldman, Johanna A L; Bender, Michael L; Morel, François M M

2017-04-01

The response of marine phytoplankton to the ongoing increase in atmospheric pCO 2 reflects the consequences of both increased CO 2 concentration and decreased pH in surface seawater. In the model diatom Thalassiosira weissflogii, we explored the effects of varying pCO 2 and pH, independently and in concert, on photosynthesis and respiration by incubating samples in water enriched in H 2 18 O. In long-term experiments (~6-h) at saturating light intensity, we observed no effects of pH or pCO 2 on growth rate, photosynthesis or respiration. This absence of a measurable response reflects the very small change in energy used by the carbon concentrating mechanism (CCM) compared to the energy used in carbon fixation. In short-term experiments (~3 min), we also observed no effects of pCO 2 or pH, even under limiting light intensity. We surmise that in T. weissflogii, it is the photosynthetic production of NADPH and ATP, rather than the CO 2 -saturation of Rubisco that controls the rate of photosynthesis at low irradiance. In short-term experiments, we observed a slightly higher respiration rate at low pH at the onset of the dark period, possibly reflecting the energy used for exporting H + and maintaining pH homeostasis. Based on what is known of the biochemistry of marine phytoplankton, our results are likely generalizable to other diatoms and a number of other eukaryotic species. The direct effects of ocean acidification on growth, photosynthesis and respiration in these organisms should be small over the range of atmospheric pCO 2 predicted for the twenty-first century.

Short-Term and Long-Term Survival and Virulence of Legionella pneumophila in the Defined Freshwater Medium Fraquil.

PubMed

Mendis, Nilmini; McBride, Peter; Faucher, Sébastien P

2015-01-01

Legionella pneumophila (Lp) is the etiological agent responsible for Legionnaires' disease, a potentially fatal pulmonary infection. Lp lives and multiplies inside protozoa in a variety of natural and man-made water systems prior to human infection. Fraquil, a defined freshwater medium, was used as a highly reproducible medium to study the behaviour of Lp in water. Adopting a reductionist approach, Fraquil was used to study the impact of temperature, pH and trace metal levels on the survival and subsequent intracellular multiplication of Lp in Acanthamoeba castellanii, a freshwater protozoan and a natural host of Legionella. We show that temperature has a significant impact on the short- and long-term survival of Lp, but that the bacterium retains intracellular multiplication potential for over six months in Fraquil. Moreover, incubation in Fraquil at pH 4.0 resulted in a rapid decline in colony forming units, but was not detrimental to intracellular multiplication. In contrast, variations in trace metal concentrations had no impact on either survival or intracellular multiplication in amoeba. Our data show that Lp is a resilient bacterium in the water environment, remaining infectious to host cells after six months under the nutrient-deprived conditions of Fraquil.

Acid-base balance and metabolic response of the sea urchin Paracentrotus lividus to different seawater pH and temperatures.

PubMed

Catarino, Ana I; Bauwens, Mathieu; Dubois, Philippe

2012-07-01

In order to better understand if the metabolic responses of echinoids could be related to their acid-base status in an ocean acidification context, we studied the response of an intertidal sea urchin species, Paracentrotus lividus, submitted to low pH at two different temperatures. Individuals were submitted to control (8.0) and low pH (7.7 and 7.4) at 10°C and 16°C (19 days). The relation between the coelomic fluid acid-base status, the RNA/DNA ratio of gonads and the individual oxygen uptake were studied. The coelomic fluid pH decreased with the aquarium seawater, independently of temperature, but this explained only 13% of the pH variation. The coelomic fluid showed though a partial buffer capacity that was not related to skeleton dissolution ([Mg(2+)] and [Ca(2+)] did not differ between pH treatments). There was an interaction between temperature and pH on the oxygen uptake (V (O2)) which was increased at pH 7.7 and 7.4 at 10°C in comparison with controls, but not at 16°C, indicating an upregulation of the metabolism at low temperature and pH. However, gonad RNA/DNA ratios did not differ according to pH and temperature treatments, indicating that even if maintenance of physiological activities has an elevated metabolic cost when individuals are exposed to stress, they are not directly affected during short-term exposure. Long-term studies are needed in order to verify if gonad production/growth will be affected by low pH seawaters exposure.

Effect of inflammatory conditions and H2O2 on bare and coated Ti-6Al-4V surfaces: Corrosion behavior, metal ion release and Ca-P formation under long-term immersion in DMEM

NASA Astrophysics Data System (ADS)

Höhn, Sarah; Virtanen, Sannakaisa

2015-12-01

The surface oxide film and calcium-phosphate (Ca-P) formation on Ti-6Al-4V during long-term immersion in biological environments play a decisive role for the biocompatibility of the implant. Hence, the aim of the study was to evaluate the corrosion resistance, metal ion release and Ca-P formation in DMEM under physiological conditions at pH values of 7.4 and in comparison under simulated inflammatory conditions with pH 5 and in presence of H2O2. Furthermore, the influence of the immersion conditions was investigated on different surface treatments: on bare Ti-6Al-4V, after anodization, and for TiO2 nanoparticle (NP) and hydroxyapatite (HA)-incorporated TiO2-NP coatings. In the absence of H2O2, the impedance response indicated a stable thin oxide film and Ca-P formation after 28 days or 56 days depending on the coating, while under inflammatory conditions the Ca-P formation on the surface is time-delayed and dissolution of the anodized oxide layer as well as selective etching of the β-phase and phase boundaries in case of the bare alloy occur. Electrochemical impedance spectroscopy (EIS), however, indicates a good general corrosion behavior in all cases. The quantities of Ti, Al and V released from the bare and coated Ti-6Al-4V alloy markedly increased with decreasing pH (pH ≤ 5). Although the rapid increase of metal release was observed for all samples at pH 5, the quantities were significantly higher for the bare and anodized alloy than after coating with TiO2-NP or HA.

Proton sensitivity of rat cerebellar granule cell GABAA receptors: dependence on neuronal development

PubMed Central

Krishek, Belinda J; Smart, Trevor G

2001-01-01

The effect of GABAA receptor development in culture on the modulation of GABA-induced currents by external H+ was examined in cerebellar granule cells using whole-cell and single-channel recording. Equilibrium concentration-response curves revealed a lower potency for GABA between 11 and 12 days in vitro (DIV) resulting in a shift of the EC50 from 10.7 to 2.4 μM. For granule cells before 11 DIV, the peak GABA-activated current was inhibited at low external pH and enhanced at high pH with a pKa of 6.65. For the steady-state response, low pH was inhibitory with a pKa of 5.56. After 11 DIV, the peak GABA-activated current was largely pH insensitive; however, the steady-state current was potentiated at low pH with a pKa of 6.84. Single GABA-activated ion channels were recorded from outside-out patches of granule cell bodies. At pH 5.4-9.4, single GABA channels exhibited multiple conductance states occurring at 22-26, 16-17 and 12-14 pS. The conductance levels were not significantly altered over the time period of study, nor by changing the external H+ concentration. Two exponential functions were required to fit the open-time frequency histograms at both early (< 11 DIV) and late (> 11 DIV) development times at each H+ concentration. The short and long open time constants were unaffected either by the extracellular H+ concentration or by neuronal development. The distribution of all shut times was fitted by the sum of three exponentials designated as short, intermediate and long. At acidic pH, the long shut time constant decreased with development as did the relative contribution of these components to the overall distribution. This was concurrent with an increase in the mean probability of channel opening. In conclusion, this study demonstrates in cerebellar granule cells that external pH can either reduce, have no effect on, or enhance GABA-activated responses depending on the stage of development, possibly related to the subunit composition of the GABAA receptors. The mode of interaction of H+ at the single-channel level and implications of such interactions at cerebellar granule cell GABAA receptors are discussed. PMID:11208970

EXPERIMENTAL ACIDIFICATION OF A STREAM TRIBUTARY TO HUBBARD BROOK

EPA Science Inventory

Long (5 mo.) and short-term (1 h to 2 days) effects of acidic pH have been measured in a poorly buffered mountain stream within the Hubbard Brook Experimental Forest, New Hampshire. Over a 5-month period aluminum, calcium, magnesium, and potassium were mobilized into the stream w...

SOM Stability under Long-term Recovery from Acidic Deposition in a Northern Hardwood Forest

NASA Astrophysics Data System (ADS)

Marinos, R.; Bernhardt, E. S.; Groffman, P. M.; Likens, G.; Rosi-Marshall, E. J.

2016-12-01

Forested ecosystems in the Northeast U.S.A. are currently recovering from decades of acidic deposition that decreased soil pH, leached base cations, and increased soluble aluminum (Al) in soils. Because most research examining SOM dynamics in these ecosystems has taken place against a background of acidic deposition, it remains poorly understood how SOM pools will change as a result of the long-term trajectory of recovery from acidic deposition throughout the region. These potential changes may alter soil fertility status as well as the chemistry of receiving freshwater bodies. Watershed-scale experiments that increase soil pH and base cation status may provide insight into how SOM pools in these recovering ecosystems will respond on timescales of decades to centuries, but results from these experiments have been equivocal. At Hubbard Brook Experimental Forest in New Hampshire, a watershed-scale acid remediation treatment of calcium silicate caused a 40% decline of SOM pools in the humic (Oa) soil horizon, in addition to increasing soil pH and base saturation. We sought to understand the mechanisms driving this substantial loss of SOM. We found that, in the Oa horizon of the treatment watershed, respiration and nitrogen (N) mineralization were significantly, positively correlated with exchangeable calcium (Ca) and uncorrelated with soil pH; in a linear regression, exchangeable Ca explained 76% of the variation in respiration and 74% of the variation in nitrogen mineralization in the treatment soils. These metrics were uncorrelated in soils from a nearby reference watershed, where Ca is uniformly low. This suggests that the rate and magnitude of soil Ca changes during recovery from acid deposition may provide an important long-term control on the stability of SOM in these ecosystems. Additionally, we found substantially enhanced in-stream biotic uptake of the inorganic N released from this enhanced SOM decomposition, with growing-season N flux from the treatment watershed attenuated by 15-55% due to in-stream uptake. This suggests that receiving headwaters undergoing recovery from acid deposition have the capacity to mitigate enhanced nutrient efflux due to increased SOM decomposition.

Comparative analysis of time-scaling properties about water pH in Poyang Lake Inlet and Outlet on the basis of fractal methods.

PubMed

Shi, K; Liu, C Q; Huang, Z W; Zhang, B; Su, Y

2010-01-01

Detrended fluctuation analysis (DFA) and multifractal methods are applied to the time-scaling properties analysis of water pH series in Poyang Lake Inlet and Outlet in China. The results show that these pH series are characterised by long-term memory and multifractal scaling, and these characteristics have obvious differences between the Lake Inlet and Outlet. The comparison results suggest that monofractal and multifractal parameters can be quantitative dynamical indexes reflecting the capability of anti-acidification of Poyang Lake. Furthermore, we investigated the frequency-size distribution of pH series in Poyang Lake Inlet and Outlet. Our findings suggest that water pH is an example of a self-organised criticality (SOC) process. The results show that it is different SOC behaviours that result in the differences of power-law relations between pH series in Poyang Lake Inlet and Outlet. This work can be helpful to improvement of modelling of lake water quality.

Anomalous Dynamics of a Lipid Recognition Protein on a Membrane Surface

PubMed Central

Yamamoto, Eiji; Kalli, Antreas C.; Akimoto, Takuma; Yasuoka, Kenji; Sansom, Mark S. P.

2015-01-01

Pleckstrin homology (PH) domains are lipid-binding modules present in peripheral membrane proteins which interact with phosphatidyl-inositol phosphates (PIPs) in cell membranes. We use multiscale molecular dynamics simulations to characterize the localization and anomalous dynamics of the DAPP1 PH domain on the surface of a PIP-containing lipid bilayer. Both translational and rotational diffusion of the PH domain on the lipid membrane surface exhibit transient subdiffusion, with an exponent α ≈ 0.5 for times of less than 10 ns. In addition to a PIP3 molecule at the canonical binding site of the PH domain, we observe additional PIP molecules in contact with the protein. Fluctuations in the number of PIPs associated with the PH domain exhibit 1/f noise. We suggest that the anomalous diffusion and long-term correlated interaction of the PH domain with the membrane may contribute to an enhanced probability of encounter with target complexes on cell membrane surfaces. PMID:26657413

Development of a fluorescence endoscopic system for pH mapping of gastric tissue

NASA Astrophysics Data System (ADS)

Rochon, Philippe; Mordon, Serge; Buys, Bruno; Dhelin, Guy; Lesage, Jean C.; Chopin, Claude

2003-10-01

Measurement of gastro intestinal intramucosal pH (pHim) has been recognized as an important factor in the detection of hypoxia induced dysfonctions. However, current pH measurements techniques are limited in terms of time and spatial resolutions. A major advance in accurate pH measurement was the development of the ratiometric fluorescent indicator dye, 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein (BCECF). BCECF which pKa is in the physiological pH range is suitable for pH tissue measurements in vivo. This study aimed to develop and evaluate an endoscopic imaging system for real time pH measurements in the stomach in order to provide to ICU a new tool for gastro intestinal intramucosal pH (pHim) measurements. This fluorescence imaging technique should allow the temporal exploration of sequential events, particularly in ICU where the pHim provides a predictive information of the patient' status. The experimental evaluations of this new and innovative endoscopic fluorescence system confirms the accuracy of pH measurement using BCECF.

Solar industrial process heat systems: An assessment of standards for materials and components

NASA Astrophysics Data System (ADS)

Rossiter, W. J.; Shipp, W. E.

1981-09-01

A study was conducted to obtain information on the performance of materials and components in operational solar industrial process heat (PH) systems, and to provide recommendations for the development of standards including evaluative test procedures for materials and components. An assessment of the needs for standards for evaluating the long-term performance of materials and components of IPH systems was made. The assessment was based on the availability of existing standards, and information obtained from a field survey of operational systems, the literature, and discussions with individuals in the industry. Field inspections of 10 operational IPH systems were performed.

Jupiter Climatological Database from Frequent 5-25 µm Mid-IR Spectral Mapping using IRTF/TEXES

NASA Astrophysics Data System (ADS)

Fletcher, Leigh N.; Orton, Glenn S.; Greathouse, Thomas K.; Sinclair, James; Irwin, Patrick G. J.; Giles, Rohini S.; Encrenaz, Therese; Drossart, Pierre

2015-11-01

We report on the development of a long-term Jovian Climatological Database (JCliD) to explore variability in Jupiter’s atmospheric temperatures, winds, clouds and composition- from long-term seasonal changes to short-term major upheavals. Radiometrically calibrated spectral scan maps of Jupiter have been regularly obtained using the TEXES instrument (Texas Echelon cross Echelle Spectrograph, Lacy et al. 2002, PASP 114, p153-168) between 2012 and 2015. Ten settings between 5 and 25 µm (10-20 cm-1 wide settings at spectral resolutions of 2000-10000) were selected to be sensitive to jovian temperatures (via H2, CH4 and CH3D), tropospheric phosphine and ammonia, tropospheric haze opacity and stratospheric hydrocarbons ethane and acetylene. Diffraction-limited spatial resolutions of 0.6-1.6” were achieved. Observations over consecutive nights allow the creation of full spatial maps for comparison with the visible light record, revealing ephemeral stratospheric wave activity, NEB hotspots, heating at the northern auroral oval, and complex thermal signatures associated with tropospheric vortices, waves and barges. Full spectra are inverted via the NEMESIS retrieval algorithm (Irwin et al., 2008, JSQRT 109, p1136-1150) to map temperatures at multiple altitudes (1-600 mbar), winds, aerosol opacity and gaseous composition. The spatial and spectral resolutions of the resulting maps surpass those obtained during the Cassini flyby of Jupiter in 2000, and permit temporal interpolation to understand the environmental conditions related to the emergence and evolution of discrete features. In December 2014 we find warmer temperatures in the northern stratosphere (a seasonal effect in late northern summer despite Jupiter’s small axial tilt); a hemispheric asymmetry in the tropospheric PH3 distribution due to variations in the vigour of vertical mixing and photolytic shielding; elevated PH3, aerosols and NH3 in the equatorial zone (EZ) related to equatorial uplift; elevated aerosol opacity in the northern and southern tropical zones (NTrZ and STrZ); and enhanced PH3 and aerosols over the Great Red Spot. Maps of retrieved properties will be assembled as a database (JCliD) to aid in the interpretation of Juno data during 2016-2017.

Short- and Long-Term Outcomes of Student Field Research Experiences in Special Populations.

PubMed

Soliman, Amr S; Chamberlain, Robert M

2016-06-01

Global health education and training of biomedical students in international and minority health research is expending through U.S. academic institutions. This study addresses the short- and long-term outcomes of an NCI-funded R25 short-term summer field research training program. This program is designed for MPH and Ph.D. students in cancer epidemiology and related disciplines, in international and minority settings (special populations) in a recent 7-year period. Positive short-term outcome of 73 students was measured as publishing a manuscript from the field research data and having a job in special populations. Positive long-term outcome was measured as having a post-doc position, being in a doctoral program, and/or employment in special populations at least 3 years from finishing the program. Significant factors associated with both short- and long-term success included resourcefulness of the student and compatibility of personalities and interests between the student and the on-campus and off-campus mentors. Short-term-success of students who conducted international filed research was associated with visits of the on-campus mentor to the field site. Short-term success was also associated with extent of mentorship in the field site and with long-term success. Future studies should investigate how field research sites could enhance careers of students, appropriateness of the sites for specific training competencies, and how to maximize the learning experience of students in international and minority research sites.

Local technicians in long-term research projects: evaluation of 25 years experience in an active tropical research station.

PubMed

Hurtado, Johanna; Clark, David B

2011-12-01

Most field ecology is conceived and financed by scientists from urban areas but is actually carried out in rural areas. Field staff can either be imported from urban areas or recruited from local residents. We evaluated the advantages and disadvantages of involving rural residents as local technicians over a 25- year period at active field research site in Costa Rica. We defined "local technicians" as local residents with no university education who acquired significant experience in field data collection, data management and/or laboratory work. We analyzed the experiences of incorporating these technicians into field research in developing countries from the points of view of scientist and of the local technicians themselves. Primary data were written responses from to a standardized survey of 19 senior scientists and Ph.D. students,and results from standardized personal interviews with 22 local technicians. Researchers highlighted the advantages of highly-skilled technicians with minimal staff turnover, as well as the technicians' knowledge of local ecological conditions. Local technicians considered the primary advantages of their jobs to be opportunities for continuing education training in science as well as cultural enrichment through interactions with people of different cultures. The main challenges identified by researchers were the lack of long-term funding for projects and extended training required for local technicians. Local technicians can be of great benefit to research projects by providing high-quality data collection at reasonable costs with low staff turnover. Over the last 25 years the research model at the field station we studied has evolved to the point that most long-term projects now depend heavily on local technicians. This model of involving local technicians in long-term research has multiple benefits for the researchers, the technicians and the local community, and could be adapted to a variety of settings in rural areas of developing countries.

Strengthening the career development of clinical translational scientist trainees: a consensus statement of the Clinical Translational Science Award (CTSA) Research Education and Career Development Committees.

PubMed

Meyers, Frederick J; Begg, Melissa D; Fleming, Michael; Merchant, Carol

2012-04-01

The challenges for scholars committed to successful careers in clinical and translational science are increasingly well recognized. The Education and Career Development (EdCD) of the national Clinical and Translational Science Award consortium gathered thought leaders to propose sustainable solutions and an agenda for future studies that would strengthen the infrastructure across the spectrum of pre- and postdoctoral, MD and PhD, scholars. Six consensus statements were prepared that include: (1) the requirement for career development of a qualitatively different investigator; (2) the implications of interdisciplinary science for career advancement including institutional promotion and tenure actions that were developed for discipline-specific accomplishments; (3) the need for long-term commitment of institutions to scholars; (4) discipline-specific curricula are still required but curricula designed to promote team work and interdisciplinary training will promote innovation; (5) PhD trainees have many pathways to career satisfaction and success; and (6) a centralized infrastructure to enhance and reward mentoring is required. Several themes cut across all of the recommendations including team science, innovation, and sustained institutional commitment. Implied themes include an effective and diverse job force and the requirement for a well-crafted public policy that supports continued investments in science education. © 2012 Wiley Periodicals, Inc.

Ehlers-Danlos syndrome: a cause of epilepsy and periventricular heterotopia.

PubMed

Verrotti, Alberto; Monacelli, Debora; Castagnino, Miriam; Villa, Maria Pia; Parisi, Pasquale

2014-11-01

Ehlers-Danlos syndrome (EDS) comprises a variety of inherited connective tissue disorders that have been described in association with various neurological features. Until now the neurological symptoms have not been studied in detail; therefore, the aim of this review is to analyze the possible association between EDS, epilepsy and periventricular heterotopia (PH). We have carried out a critical review of all cases of epilepsy in EDS patients with and without PH. Epilepsy is a frequent neurological manifestation of EDS; generally, it is characterized by focal seizures with temporo-parieto-occipital auras and the most common EEG findings epileptiform discharges and slow intermittent rhythm with delta-theta waves. Epilepsy in EDS patients is usually responsive to common antiepileptic therapy; very few cases of drug resistant focal epilepsy requested surgical treatment, with favorable results in terms of outcome. Epilepsy is the most common presenting neurological manifestation associated with PH in EDS patients. Abnormal anatomic circuitries (including heterotopic nodules) could generate epilepsy in patients with PH. Among the principal neurological manifestations, epilepsy and PH have a considerable importance and can influence the long-term evolution of these patients. We hypothesize that PH may determine the epileptic manifestations in patients with EDS; much remains to be learnt about the relationships between nodules and the epileptic manifestations in EDS syndrome. Copyright © 2014 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Response of Syntrophic Propionate Degradation to pH Decrease and Microbial Community Shifts in an UASB Reactor.

PubMed

Zhang, Liguo; Ban, Qiaoying; Li, Jianzheng; Jha, Ajay Kumar

2016-08-28

The effect of pH on propionate degradation in an upflow anaerobic sludge blanket (UASB) reactor containing propionate as a sole carbon source was studied. Under influent propionate of 2,000 mg/l and 35ºC, propionate removal at pH 7.5-6.8 was above 93.6%. Propionate conversion was significantly inhibited with stepwise pH decrease from pH 6.8 to 6.5, 6.0, 5.5, 5.0, 4.5, and then to 4.0. After long-term operation, the propionate removal at pH 6.5-4.5 maintained an efficiency of 88.5%-70.1%, whereas propionate was hardly decomposed at pH 4.0. Microbial composition analysis showed that propionate-oxidizing bacteria from the genera Pelotomaculum and Smithella likely existed in this system. They were significantly reduced at pH ≤5.5. The methanogens in this UASB reactor belonged to four genera: Methanobacterium, Methanospirillum, Methanofollis, and Methanosaeta. Most detectable hydrogenotrophic methanogens were able to grow at low pH conditions (pH 6.0-4.0), but the acetotrophic methanogens were reduced as pH decreased. These results indicated that propionate-oxidizing bacteria and acetotrophic methanogens were more sensitive to low pH (5.5-4.0) than hydrogenotrophic methanogens.

Liquid crystalline phase behavior of protein fibers in water: experiments versus theory.

PubMed

Jung, Jin-Mi; Mezzenga, Raffaele

2010-01-05

We have developed a new method allowing the study of the thermodynamic phase behavior of mesoscopic colloidal systems consisting of amyloid protein fibers in water, obtained by heat denaturation and aggregation of beta-lactoglobulin, a dairy protein. The fibers have a cross section of about 5.2 nm and two groups of polydisperse contour lengths: (i) long fibers of 1-20 microm, showing semiflexible behavior, and (ii) short rods of 100-200 nm long, obtained by cutting the long fibers via high-pressure homogenization. At pH 2 without salt, these fibers are highly charged and stable in water. We have studied the isotropic-nematic phase transition for both systems and compared our results with the theoretical values predicted by Onsager's theory. The experimentally measured isotropic-nematic phase transition was found to occur at 0.4% and at 3% for the long and short fibers, respectively. For both systems, this phase transition occurs at concentrations more than 1 order of magnitude lower than what is expected based on Onsager's theory. Moreover, at low enough pH, no intermediate biphasic region was observed between the isotropic phase and the nematic phase. The phase diagrams of both systems (pH vs concentration) showed similar, yet complex and rich, phase behavior. We discuss the possible physical fundamentals ruling the phase diagram as well as the discrepancy we observe for the isotropic-nematic phase transition between our experimental results and the predicted theoretical results. Our work highlights that systems formed by water-amyloid protein fibers are way too complex to be understood based solely on Onsager's theories. Experimental results are revisited in terms of the Flory's theory (1956) for suspensions of rods, which allows accounting for rod-solvent hydrophobic interactions. This theoretical approach allows explaining, on a semiquantitative basis, most of the discrepancies observed between the experimental results and Onsager's predictions. The sources of protein fibers complex colloidal behavior are analyzed and discussed at length.

Long-term dynamic and pseudo-state modeling of complete partial nitrification process at high nitrogen loading rates in a sequential batch reactor (SBR).

PubMed

Soliman, Moomen; Eldyasti, Ahmed

2017-06-01

Recently, partial nitrification has been adopted widely either for the nitrite shunt process or intermediate nitrite generation step for the Anammox process. However, partial nitrification has been hindered by the complexity of maintaining stable nitrite accumulation at high nitrogen loading rates (NLR) which affect the feasibility of the process for high nitrogen content wastewater. Thus, the operational data of a lab scale SBR performing complete partial nitrification as a first step of nitrite shunt process at NLRs of 0.3-1.2kg/(m 3 d) have been used to calibrate and validate a process model developed using BioWin® in order to describe the long-term dynamic behavior of the SBR. Moreover, an identifiability analysis step has been introduced to the calibration protocol to eliminate the needs of the respirometric analysis for SBR models. The calibrated model was able to predict accurately the daily effluent ammonia, nitrate, nitrite, alkalinity concentrations and pH during all different operational conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Long-term passive restoration following fluvial deposition of sulphidic copper tailings: nature filters out the solutions.

PubMed

Nikolic, Nina; Böcker, Reinhard; Nikolic, Miroslav

2016-07-01

Despite the growing popularity of ecological restoration approach, data on primary succession on toxic post-mining substrates, under site environmental conditions which considerably differ from the surrounding environment, are still scarce. Here, we studied the spontaneous vegetation development on an unusual locality created by long-term and large-scale fluvial deposition of sulphidic tailings from a copper mine in a pronouncedly xerothermic, calcareous surrounding. We performed multivariate analyses of soil samples (20 physical and chemical parameters) and vegetation samples (floristic and structural parameters in three types of occurring forests), collected along the pollution gradients throughout the affected floodplain. The nature can cope with two types of imposed constraints: (a) excessive Cu concentrations and (b) very low pH, combined with nutrient deficiency. The former will still allow convergence to the original vegetation, while the latter will result in novel, depauperate assemblages of species typical for cooler and moister climate. Our results for the first time demonstrate that with the increasing severity of environmental filtering, the relative importance of the surrounding vegetation for primary succession strongly decreases.

The geostatistic-based spatial distribution variations of soil salts under long-term wastewater irrigation.

PubMed

Wu, Wenyong; Yin, Shiyang; Liu, Honglu; Niu, Yong; Bao, Zhe

2014-10-01

The purpose of this study was to determine and evaluate the spatial changes in soil salinity by using geostatistical methods. The study focused on the suburb area of Beijing, where urban development led to water shortage and accelerated wastewater reuse to farm irrigation for more than 30 years. The data were then processed by GIS using three different interpolation techniques of ordinary kriging (OK), disjunctive kriging (DK), and universal kriging (UK). The normality test and overall trend analysis were applied for each interpolation technique to select the best fitted model for soil parameters. Results showed that OK was suitable for soil sodium adsorption ratio (SAR) and Na(+) interpolation; UK was suitable for soil Cl(-) and pH; DK was suitable for soil Ca(2+). The nugget-to-sill ratio was applied to evaluate the effects of structural and stochastic factors. The maps showed that the areas of non-saline soil and slight salinity soil accounted for 6.39 and 93.61%, respectively. The spatial distribution and accumulation of soil salt were significantly affected by the irrigation probabilities and drainage situation under long-term wastewater irrigation.

Evaluation of swine fertilisation medium (SFM) efficiency in preserving spermatozoa quality during long-term storage in comparison to four commercial swine extenders.

PubMed

Fantinati, P; Zannoni, A; Bernardini, C; Forni, M; Tattini, A; Seren, E; Bacci, M L

2009-02-01

In pig production, artificial insemination is widely carried out and the use of fresh diluted semen is predominant. For this reason, there are increasing interests in developing new extenders and in establishing the optimal storage conditions for diluted spermatozoa. In the last few decades, we utilised a homemade diluent (swine fertilisation medium (SFM)) for spermatozoa manipulation and biotechnological application as the production of transgenic pigs utilising the sperm-mediated gene transfer technique. The purpose of the present study is therefore to analyse the ability of SFM, in comparison to four commercial extenders, in preserving the quality of diluted boar semen stored at 16.5°C till 15 days. We utilised some of the main predictive tests as objectively measured motility, acrosome and sperm membrane integrity, high mitochondrial membrane potential and pH. Based on our in vitro study, SFM could be declared as a good long-term extender, able to preserve spermatozoa quality as well as Androhep Enduraguard for up to 6 to 9 days and more.

Developing Critical Loads of acidity for streams in the Great Smoky Mountains National Park, using PnET-BGC model

NASA Astrophysics Data System (ADS)

Fakhraei, H.

2015-12-01

Acid deposition has impaired acid-sensitive streams and reduced aquatic biotic integrity in Great Smoky Mountains National Park (GRSM) by decreasing pH and acid neutralizing capacity (ANC). Twelve streams in GRSM are listed by the state of Tennessee as impaired due to low stream pH (pH<6.0) under Section 303(d) of the Clean Water Act. A dynamic biogeochemical model, PnET-BGC, was used to evaluate past, current and potential future changes in soil and water chemistry of watersheds of GRSM in response to changes in acid deposition. Calibrating 30 stream-watersheds in GRSM (including 12 listed impaired streams) to the long-term stream chemistry observations, the model was parameterized for the Park. The calibrated model was used to evaluate the level of atmospheric deposition above which harmful effects occur, known as "critical loads", for individual study watersheds. Estimated critical loads and exceedances (levels of deposition above the critical load) of atmospheric sulfur and nitrogen deposition were depicted through geographic information system maps. Accuracy of model simulations in the presence of uncertainties in the estimated model parameters and inputs was assessed using three uncertainty and sensitivity techniques.

Accelerated ageing of blended OPC cements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quillin, K.C.; Duerden, S.L.; Majumdar, A.J.

1994-12-31

An accelerated experimental technique using high water:cement ratios has been developed to study the long term hydration of blended cements that may be used in a repository for the disposal of radioactive waste. This technique has been used to investigate the hydration reactions of Ordinary Portland Cement (OPC) blended with ground granulated blastfurnace slag (ggbs) or pulverised fuel ash (pfa). The effects of high sulphate-bearing and high carbonate-bearing ground waters on the compounds formed on hydration were investigated. Solid/solution compositional data were collected during the course of the hydration process for periods up to 2 years. Thomsonite, thaumasite, afwillite andmore » a tobermorite-like phase were found in addition to the expected cement hydration products. The pH of the aqueous solution in contact with 60 pfa:40 OPC blends hydrated at 90{degrees}C fell to below 8. This is lower than the value required to inhibit the corrosion of steel canisters in a repository. The pH of the aqueous solution in contact with OPC and 75 ggbs:25 OPC blends remained above 11, although if the ground waters in contact with the OPC/ggbs blends were periodically replaced the pH eventually fell below 10.« less

Characterization of squamous esophageal cells resistant to bile acids at acidic pH: implication for Barrett's esophagus pathogenesis

PubMed Central

Goldman, Aaron; Chen, Hwu Dau Rw; Roesly, Heather B.; Hill, Kimberly A.; Tome, Margaret E.; Dvorak, Bohuslav; Bernstein, Harris

2011-01-01

Barrett's esophagus (BE) is a premalignant condition, where normal squamous epithelium is replaced by intestinal epithelium. BE is associated with an increased risk of developing esophageal adenocarcinoma (EAC). However, the BE cell of origin is not clear. We hypothesize that BE tissue originates from esophageal squamous cells, which can differentiate to columnar cells as a result of repeated exposure to gastric acid and bile acids, two components of refluxate implicated in BE pathology. To test this hypothesis, we repeatedly exposed squamous esophageal HET1A cells to 0.2 mM bile acid (BA) cocktail at pH 5.5 and developed an HET1AR-resistant cell line. These cells are able to survive and proliferate after repeated 2-h treatments with BA at pH 5.5. HET1AR cells are resistant to acidification and express markers of columnar differentiation, villin, CDX2, and cytokeratin 8/18. HET1AR cells have increased amounts of reactive oxygen species, concomitant with a decreased level and activity of manganese superoxide dismutase compared with parental cells. Furthermore, HET1AR cells express proteins and activate signaling pathways associated with inflammation, cell survival, and tumorigenesis that are thought to contribute to BE and EAC development. These include STAT3, NF-κB, epidermal growth factor receptor (EGFR), cyclooxygenase-2, interleukin-6, phosphorylated mammalian target of rapamycin (p-mTOR), and Mcl-1. The expression of prosurvival and inflammatory proteins and resistance to cell death could be partially modified by inhibition of STAT3 signaling. In summary, our study shows that long-term exposure of squamous cells to BA at acidic pH causes the cells to display the same characteristics and markers as BE. PMID:21127259

Micro-scale investigations on soil heterogeneity: Impacts on Zn retention and uptake in Zn contaminated soils

USDA-ARS?s Scientific Manuscript database

Metal contaminants in soils can persist for millennia, causing lasting negative impacts on local ecosystems. Long-term contaminant bioavailability is related to soil pH and the strength and stability of their solid phase associations. We combined physical density separation with synchrotron-based mi...

Geochemical Impacts to Groundwater from Geologic Carbon Sequestration: Controls on pH and Inorganic Carbon Concentrations from Reaction Path and Kinetic Modeling

EPA Science Inventory

Geologic carbon sequestration has the potential to cause long-term reductions in global emissions of carbon dioxide to the atmosphere. Safe and effective application of carbon sequestration technology requires an understanding of the potential risks to the quality of underground...

The effects of tea catechins on fecal conditions of elderly residents in a long-term care facility.

PubMed

Goto, K; Kanaya, S; Ishigami, T; Hara, Y

1999-01-01

This study was carried out to evaluate the effects of tea catechins on fecal contents and metabolites of elderly people who were on a diet of solid food. The subjects were 35 residents in a long-term care facility who were all on the same diet, consisting of rice gruel and minced food. Tea catechins (300 mg), which were divided into 3 doses a day, were a meal supplement every day for 6 weeks. Fecal specimens were collected by the nursing staff, and their moisture content, pH, ammonia, sulfide, and oxidation-reduction potential (ORP) were determined before, during, and after the administration of tea catechins. In a comparison of values before the administration, all these fecal parameters decreased significantly during the tea catechin administration. After termination of the administration, these data tended to return toward the levels before administration. The reduction of such fecal parameters as moisture, pH, ammonia, sulfide, and ORP by tea catechin administration indicated very favorable improvements of the subjects' bowel conditions.

Advanced biological activated carbon filter for removing pharmaceutically active compounds from treated wastewater.

PubMed

Sbardella, Luca; Comas, Joaquim; Fenu, Alessio; Rodriguez-Roda, Ignasi; Weemaes, Marjoleine

2018-04-28

Through their release of effluents, conventional wastewater treatment plants (WWTPs) represent a major pollution point sources for pharmaceutically active compounds (PhACs) in water bodies. The combination of a biological activated carbon (BAC) filter coupled with an ultrafiltration (UF) unit was evaluated as an advanced treatment for PhACs removal at pilot scale. The BAC-UF pilot plant was monitored for one year. The biological activity of the biofilm that developed on the granular activated carbon (GAC) particles and the contribution of this biofilm to the overall removal of PhACs were evaluated. Two different phases were observed during the long-term monitoring of PhACs removal. During the first 9200 bed volumes (BV; i.e., before GAC saturation), 89, 78, 83 and 79% of beta-blockers, psychiatric drugs, antibiotics and a mix of other therapeutic groups were removed, respectively. The second phase was characterized by deterioration of the overall performances during the period between 9200 and 13,800 BV. To quantify the respective contribution of adsorption and biodegradation, a lab-scale setup was operated for four months and highlighted the essential role played by GAC in biofiltration units. Physical adsorption was indeed the main removal mechanism. Nevertheless, a significant contribution due to biological activity was detected for some PhACs. The biofilm contributed to the removal of 22, 25, 30, 32 and 35% of ciprofloxacin, bezafibrate, ofloxacin, azithromycin and sulfamethoxazole, respectively. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Modelling of Pesticide Transport During An Injection Experiment In A Physical and Geochemical Heterogeneous Aquifer

NASA Astrophysics Data System (ADS)

Hojberg, A. L.; Engesgaard, P.; Bjerg, P. L.

The fate of selected pesticides under natural groundwater conditions was studied by natural gradient short and long term injection experiments in a shallow uncon- fined aerobic aquifer. Bentazone, DNOC, MCPP, dichlorprop, isoproturon, and BAM (dichlobenil metabolite) were injected in aqueous solution with bromide as a nonre- active tracer. The Bromide and pesticide plumes were sampled during the initial 25 m of migration in a dense monitoring net of multilevel samplers. The aquifer was physical and geochemical heterogeneous, which affected transport of several of the pesticides. A 3D reactive transport code was developed including one- and two-site linear/nonlinear equilibrium/nonequilibrium sorption and first-order as well as single Monod degradation kinetic coupled to microbial growth. Model simulations demon- strated that microbial growth was likely supported by the phenoxy acids MCPP and dichlorprop, while degradation of DNOC was adequately described by first-order degradation with no initial lag time. An observed vertical increase in pH was observed at the site and implemented in the transport code. The numerical analysis indicated that degradation of the three degradable pesticides may have been affected by vertical pH variations. Spatial variability in observed DNOC sorption was similarly suspected to be an effect of varying pH. pH dependency on DNOC sorption was confirmed by the model recognized by a match to observed breakthrough at the individual sampling points, when pH variation was included in the simulations.

Influence of pH on Cr(VI) ions removal from aqueous solutions using carboxymethyl cellulose-based hydrogel as adsorbent

NASA Astrophysics Data System (ADS)

Anah, L.; Astrini, N.

2017-03-01

The major problem in heavy metal pollution is that these metals are not biodegradable and accordingly accumulate in the bodies of living organisms, causing dangerous diseases and serious cell disorder. According to World Health Organization (WHO), the long term exposure of Cr(VI) levels of over 0.1 ppm causes respiratory problems, liver and kidney damage, and carcinogenicity.Due to its easy operation and of various cheap adsorbents development, adsorption has been proved to be efficient and most economically attractive technique and feasible to the removal of toxic heavy metal from wastewater. The study aimed to report the removal of Cr(VI) ions from aqueous solutions through adsorption process using carboxymethyl cellulose-graft-poly(acrylic acid) (CMC-g-PAA) hydrogel as adsorbent.Effect of pH was studied to remove hexavalent chromium.Graft copolymerization of poly(acrylic acid) onto carboxymethyl cellulose was carried out in the presence of benzoyl peroxide redox initiator and methylenbisacrylamide as crosslinker agent. Batch experiments were carried out to investigate the effects ofinitial pH.The adsorption of Cr(VI) ions as a function of pH was conducted in the initial pH range of 1 to 8. The results indicated that acidic pH strongly favored the adsorption. The optimum pH for adsorption of Cr(VI) ranged from 1 to 3, and the maximum uptake of Cr(VI) from the solution was 6.53 mg/g at pH 1 and 30°C. FTIR spectroscopy, SEM analyses were performed on the adsorbent before and after Cr(VI) binding. All analyses confirmed the complexation of Cr(VI) ions on the adsorbent.

The effects of antiperspirant on the perineal skin flora of patients with spinal cord injury.

PubMed

Montgomerie, J Z; Gilmore, D S; Graham, I E; Schick, D G

1988-07-01

The relationship of pH and moisture to Pseudomonas aeruginosa and Klebsiella pneumoniae colonization of the perineal skin was studied in male patients with spinal cord injury. The increased pH of the perineal skin was significantly associated with the presence of P. aeruginosa but not other bacterial species. No correlation between colonization and moisture or pH and moisture was found. An antiperspirant produced a significant reduction in the number of total aerobic bacteria, total gram-negative bacilli, P. aeruginosa and K. pneumoniae over a 24-h period. Long-term use of the antiperspirant for 10 days did not alter the persistence of P. aeruginosa of the same serotypes on the perineum.

Poly[(ethylene oxide)-co-(methylene ethylene oxide)]: A hydrolytically-degradable poly(ethylene oxide) platform.

PubMed

Lundberg, Pontus; Lee, Bongjae F; van den Berg, Sebastiaan A; Pressly, Eric D; Lee, Annabelle; Hawker, Craig J; Lynd, Nathaniel A

2012-11-20

A facile method for imparting hydrolytic degradability to poly(ethylene oxide) (PEO), compatible with current PEGylation strategies, is presented. By incorporating methylene ethylene oxide (MEO) units into the parent PEO backbone, complete degradation was defined by the molar incorporation of MEO, and the structure of the degradation byproducts was consistent with an acid-catalyzed vinyl-ether hydrolysis mechanism. The hydrolytic degradation of poly[(ethylene oxide)-co-(methylene ethylene oxide)] was pH-sensitive, with degradation at pH 5 being significantly faster than at pH 7.4 at 37 °C in PBS buffer while long-term stability could be obtained in either the solid-state or at pH 7.4 at 6 °C.

Effect of Probiotic Curd on Salivary pH and Streptococcus mutans: A Double Blind Parallel Randomized Controlled Trial.

PubMed

Srivastava, Shivangi; Saha, Sabyasachi; Kumari, Minti; Mohd, Shafaat

2016-02-01

Dairy products like curd seem to be the most natural way to ingest probiotics which can reduce Streptococcus mutans level and also increase salivary pH thereby reducing the dental caries risk. To estimate the role of probiotic curd on salivary pH and Streptococcus mutans count, over a period of 7 days. This double blind parallel randomized clinical trial was conducted at the institution with 60 caries free volunteers belonging to the age group of 20-25 years who were randomly allocated into two groups. Test Group consisted of 30 subjects who consumed 100ml of probiotic curd daily for seven days while an equal numbered Control Group were given 100ml of regular curd for seven days. Saliva samples were assessed at baseline, after ½ hour 1 hour and 7 days of intervention period using pH meter and Mitis Salivarius Bacitracin agar to estimate salivary pH and S. mutans count. Data was statistically analysed using Paired and Unpaired t-test. The study revealed a reduction in salivary pH after ½ hour and 1 hour in both the groups. However after 7 days, normal curd showed a statistically significant (p< 0.05) reduction in salivary pH while probiotic curd showed a statistically significant (p< 0.05) increase in salivary pH. Similarly with regard to S. mutans colony counts probiotic curd showed statistically significant reduction (p< 0.05) as compared to normal curd. Short-term consumption of probiotic curds showed marked salivary pH elevation and reduction of salivary S. mutans counts and thus can be exploited for the prevention of enamel demineralization as a long-term remedy keeping in mind its cost effectiveness.

Effects of Long-Term Protein Restriction on Meat Quality, Muscle Amino Acids, and Amino Acid Transporters in Pigs.

PubMed

Yin, Jie; Li, Yuying; Zhu, Xiaotong; Han, Hui; Ren, Wenkai; Chen, Shuai; Bin, Peng; Liu, Gang; Huang, Xingguo; Fang, Rejun; Wang, Bin; Wang, Kai; Sun, Liping; Li, Tiejun; Yin, Yulong

2017-10-25

This study aimed to investigate the long-term effects of protein restriction from piglets to finishing pigs for 16 weeks on meat quality, muscle amino acids, and amino acid transporters. Thirty-nine piglets were randomly divided into three groups: a control (20-18-16% crude protein, CP) and two protein restricted groups (17-15-13% CP and 14-12-10% CP). The results showed that severe protein restriction (14-12-10% CP) inhibited feed intake and body weight, while moderate protein restriction (17-15-13% CP) had little effect on growth performance in pigs. Meat quality (i.e., pH, color traits, marbling, water-holding capacity, and shearing force) were tested, and the results exhibited that 14-12-10% CP treatment markedly improved muscle marbling score and increased yellowness (b*). pH value (45 min) was significantly higher in 17-15-13% CP group than that in other groups. In addition, protein restriction reduced muscle histone, arginine, valine, and isoleucine abundances and enhanced glycine and lysine concentrations compared with the control group, while the RT-PCR results showed that protein restriction downregulated amino acids transporters. Mechanistic target of rapamycin (mTOR) signaling pathway was inactivated in the moderate protein restricted group (17-15-13% CP), while severe protein restriction with dietary 14-12-10% CP markedly enhanced mTOR phosphorylation. In conclusion, long-term protein restriction affected meat quality and muscle amino acid metabolism in pigs, which might be associated with mTOR signaling pathway.

The mechanical stability of polyimide films at high pH

NASA Technical Reports Server (NTRS)

Croall, Catharine I.; St.clair, Terry L.

1990-01-01

Polyimide insulated electrical wire has been widely used in the aerospace industry in commercial, military, and to a lesser degree, general aviation aircraft since the early 1970s. Wiring failures linked to insulation damage have drawn much attention in the media and concerns have developed regarding the long term stability and safety of polyimide insulated electrical wire. The mechanical durability and chemical stability of polyimide insulated wire are affected by hydrolysis, notch propagation, wet and dry arc tracking, topcoat flaking, and degradation due to high pH fluids. Several polyimides were selected for evaluation for resistance to degradation by various aqueous alkaline solutions. The polyimides under evaluation include commercially available films such as KAPTON (tradename), APICAL (tradename), LARC-TPI, and UPILEX (tradename) R and S, as well as a number of experimental films prepared at NASA-Langley. Material properties investigated include viscosity, solubility, moisture absorption, glass transition temperature, dielectric constant, and mechanical properties before and after exposure to various conditions.

Postdoctoral Opportunities and Career Options

NASA Astrophysics Data System (ADS)

Manka, R. H.

2001-05-01

Following the completion of a Ph.D. degree, in the sciences a postdoctoral appointment has traditionally been a key step in career development to expand the student's background and broaden their perspective. The postdoctoral appointment often is almost a requirement to obtain some positions in academia and government laboratories. In addition, postdoctoral positions in industry are becoming more common and offer an opportunity to explore a field without making a long-term commitment. We describe the nature of a postdoctoral appointment and discuss the advantages and disadvantages of the recent Ph.D. taking a postdoctoral position. We comment on the role such positions play in university, government and the corporate research. Finally, we describe some of the national postdoctoral opportunities that exist including large programs offered by the National Research Council through Federal laboratories including those of NASA, NOAA, EPA, and the Department of Defense. Exciting new interdisciplinary opportunities such as fellowships at the NASA Astrobiology Institute are summarized, as are international opportunities such as the von Humboldt fellowships in Germany.

Precision medicine and personalising therapy in pulmonary hypertension: seeing the light from the dawn of a new era.

PubMed

Savale, Laurent; Guignabert, Christophe; Weatherald, Jason; Humbert, Marc

2018-06-30

Pulmonary hypertension (PH) and pulmonary arterial hypertension (PAH) include different cardiopulmonary disorders in which the interaction of multiple genes with environmental and behavioural factors modulates the onset and the progression of these severe conditions. Although the development of therapeutic agents that modulate abnormalities in three major pathobiological pathways for PAH has revolutionised our approach to the treatment of PAH, the long-term survival rate remains unsatisfactory. Accumulating evidence has underlined that clinical outcomes and responses to therapy in PAH are modified by multiple factors, including genetic variations, which will be different for each individual. Since precision medicine, also known as stratified medicine or personalised medicine, aims to better target intervention to the individual while maximising benefit and minimising harm, it has significant potential advantages. This article aims to assemble and discuss the different initiatives that are currently underway in the PH/PAH fields together with the opportunities and prospects for their use in the near future. Copyright ©ERS 2018.

Pharmaceutical care: the PCNE definition 2013.

PubMed

Allemann, Samuel S; van Mil, J W Foppe; Botermann, Lea; Berger, Karin; Griese, Nina; Hersberger, Kurt E

2014-06-01

Twenty-three years after Hepler and Strand published their well-known definition of Pharmaceutical Care (PhC), confusion remains about what the term includes and how to differentiate it from other terms. The board of the Pharmaceutical Care Network Europe (PCNE) felt the need to redefine PhC and to answer the question: "What is Pharmaceutical Care in 2013". The aims of this paper were to review existing definitions of PhC and to describe the process of developing a redefined definition. A literature search was conducted in the MEDLINE database (1964-January 2013). Keywords included "Pharmaceutical Care", "Medication (Therapy) Management", "Medicine Management", and "Pharmacist Care" in the title or abstract together with the term "defin*". To ease comparison between definitions, we developed a standardised syntax to paraphrase the definitions. During a dedicated meeting, a moderated discussion about the definition of PhC was organised. The initial literature search produced 186 hits, with eight unique PhC definitions. Hand searching identified a further 11 unique definitions. These 19 definitions were paraphrased using the standardised syntax (provider, recipient, subject, outcome, activities). Fourteen members of PCNE and 10 additional experts attended the moderated discussion. Working groups of increasing size developed intermediate definitions, which had similarities and differences to those retrieved in the literature search. At the end of the session, participants reached a consensus on a "PCNE definition of Pharmaceutical Care" reading: "Pharmaceutical Care is the pharmacist's contribution to the care of individuals in order to optimize medicines use and improve health outcomes". It was possible to paraphrase definitions of PhC using a standardised syntax focusing on the provider, recipient, subject, outcomes, and activities included in PhC practice. During a one-day workshop, experts in PhC research agreed on a definition, intended to be applicable for the present time, representative for various work settings, and valid for countries inside and outside of Europe.

Development of Ocean Acidification Flow-Thru Experimental Raceway Units (OAFTERU): Simulating the Future Reefs in the Keys Today

NASA Astrophysics Data System (ADS)

Hall, E. R.; Vaughan, D.; Crosby, M. P.

2011-12-01

Ocean acidification, a consequence of anthropogenic CO2 production due to fossil fuel combustion, deforestation, and cement production, has been referred to as "the other CO2 problem" and is receiving much attention in marine science and public policy communities. Critical needs that have been identified by top climate change and marine scientists include using projected pCO2 (partial pressure of CO2 in seawater) levels in manipulative experiments to determine physiological indices of ecologically important species, such as corals. Coral reefs were one of the first ecosystems to be documented as susceptible to ocean acidification. The Florida Keys reef system has already experienced a long-term deterioration, resulting in increased calls for large scale coral reef ecosystem restoration of these critical resources. It has also been speculated that this decline in reef ecosystem health may be exacerbated by increasing atmospheric CO2 levels with resulting ocean acidification. Therefore, reef resilience to ocean acidification and the potential for successful restoration of these systems under forecasted long-term modified pH conditions in the Florida Keys is of great concern. Many studies for testing effects of ocean acidification on corals have already been established and tested. However, many employ pH modification experimental designs that include addition of acid to seawater which may not mimic conditions of climate change induced ocean acidification. It would be beneficial to develop and maintain an ocean acidification testing system more representative of climate change induced changes, and specific to organisms and ecosystems indigenous to the Florida Keys reef tract. The Mote Marine Laboratory research facility in Summerland Key, FL has an established deep well from which its supply of seawater is obtained. This unique source of seawater is 80 feet deep, "fossil" marine water. It is pumped from the on-site aquifer aerated to reduce H2S and ammonia, and passed through filters for biofiltration, and clarification. The resulting water has a pH that is relatively acidic (pH around 7.6, pCO2 ranging from 200 to 2000 μatm). However, further aeration will adjust the pH of the water, by driving off more CO2, yielding pH levels at varying levels between 7.6 and present day values (>8.0-8.4). We are currently testing methods for utilizing this unique seawater system as the foundation for manipulative ocean acidification studies with Florida Keys corals and other reef ecosystem species in both flow-through and large mesocosm-based designs. Advance knowledge of potential climate-driven trends in coral growth and health will permit improved modeling for prediction and more effectively guide policy decisions for how financial resources should be directed to protection and restoration of coral reef ecosystems. Developing such longterm research infrastructure at the existing Mote Marine Laboratory Summerland Key facility will provide an optimum global research center for examining and modeling effects of ocean acidification on corals as well as other important estuarine and marine species.

Technical note: development and testing of a radio transmission pH measurement system for continuous monitoring of ruminal pH in cows.

PubMed

Sato, Shigeru; Mizuguchi, Hitoshi; Ito, Kazunori; Ikuta, Kentaro; Kimura, Atushi; Okada, Keiji

2012-03-01

An indwelling ruminal pH system has been used for the continuous recording of ruminal pH to evaluate subacute ruminal acidosis (SARA) in dairy cows. However this system does not allow the field application. The objective of this study was to develop a new radio transmission pH measurement system, and to assess its performance and usefulness in a continuous evaluation of ruminal pH for use on commercial dairy farms. The radio transmission pH measurement system consists of a wireless pH sensor, a data measurement receiver, a relay unit, and a personal computer installed special software. The pH sensor is housed in a bullet shaped bolus, which also encloses a pH amplifier circuit, a central processing unit (CPU) circuit, a radio frequency (RF) circuit, and a battery. The mean variations of the measurements by the glass pH electrode were +0.20 (n=10) after 2 months of continuous recording, compared to the values confirmed by standard pH solutions for pH 4 and pH 7 at the start of the recording. The mean lifetime of the internal battery was 2.5 months (n=10) when measurements were continuously transmitted every 10 min. Ruminal pH recorded by our new system was compared to that of the spot sampling of ruminal fluid. The mean pH for spot sampling was 6.36 ± 0.55 (n=96), and the mean pH of continuous recording was 6.22 ± 0.54 (n=96). There was a good correlation between continuous recording and spot sampling (r=0.986, P<0.01). We also examined whether our new pH system was able to detect experimentally induced ruminal acidosis in cows and to record long-term changes in ruminal pH. In the cows fed acidosis-inducing diets, the ruminal pH dropped markedly during the first 2h following the morning feeding, and decreased moreover following the evening feeding, with many pulse-like pH changes. The pH of the cows showed the lowest values of 5.3-5.2 in the midnight time period and it recovered to the normal value by the next morning feeding. In one healthy periparturient cow, the circadian changes in ruminal pH were observed as a constant pattern in the pre-parturient period, however that pattern became variable in the post-partum period. The frequency of the ruminal pH lower than 5.5 increased markedly 3 and 4 days after parturition. We demonstrated the possible application of a radio transmission pH measurement system for the assessment and monitoring of the ruminal pH of cows. Our new system might contribute to accurate assessment and prevention of SARA. Copyright © 2011 Elsevier B.V. All rights reserved.

Response of Posidonia oceanica seagrass and its epibiont communities to ocean acidification.

PubMed

Guilini, Katja; Weber, Miriam; de Beer, Dirk; Schneider, Matthias; Molari, Massimiliano; Lott, Christian; Bodnar, Wanda; Mascart, Thibaud; De Troch, Marleen; Vanreusel, Ann

2017-01-01

The unprecedented rate of CO2 increase in our atmosphere and subsequent ocean acidification (OA) threatens coastal ecosystems. To forecast the functioning of coastal seagrass ecosystems in acidified oceans, more knowledge on the long-term adaptive capacities of seagrass species and their epibionts is needed. Therefore we studied morphological characteristics of Posidonia oceanica and the structure of its epibiont communities at a Mediterranean volcanic CO2 vent off Panarea Island (Italy) and performed a laboratory experiment to test the effect of OA on P. oceanica photosynthesis and its potential buffering capacity. At the study site east of Basiluzzo Islet, venting of CO2 gas was controlled by tides, resulting in an average pH difference of 0.1 between the vent and reference site. P. oceanica shoot and leaf density was unaffected by these levels of OA, although shorter leaves at the vent site suggest increased susceptibility to erosion, potentially by herbivores. The community of sessile epibionts differed in composition and was characterized by a higher species richness at the vent site, though net epiphytic calcium carbonate concentration was similar. These findings suggest a higher ecosystem complexity at the vent site, which may have facilitated the higher diversity of copepods in the otherwise unaffected motile epibiont community. In the laboratory experiment, P. oceanica photosynthesis increased with decreasing pHT (7.6, 6.6, 5.5), which induced an elevated pH at the leaf surfaces of up to 0.5 units compared to the ambient seawater pHT of 6.6. This suggests a temporary pH buffering in the diffusive boundary layer of leaves, which could be favorable for epibiont organisms. The results of this multispecies study contribute to understanding community-level responses and underlying processes in long-term acidified conditions. Increased replication and monitoring of physico-chemical parameters on an annual scale are, however, recommended to assure that the biological responses observed during a short period reflect long-term dynamics of these parameters.

Response of Posidonia oceanica seagrass and its epibiont communities to ocean acidification

PubMed Central

Weber, Miriam; de Beer, Dirk; Schneider, Matthias; Molari, Massimiliano; Lott, Christian; Bodnar, Wanda; Mascart, Thibaud; De Troch, Marleen; Vanreusel, Ann

2017-01-01

The unprecedented rate of CO2 increase in our atmosphere and subsequent ocean acidification (OA) threatens coastal ecosystems. To forecast the functioning of coastal seagrass ecosystems in acidified oceans, more knowledge on the long-term adaptive capacities of seagrass species and their epibionts is needed. Therefore we studied morphological characteristics of Posidonia oceanica and the structure of its epibiont communities at a Mediterranean volcanic CO2 vent off Panarea Island (Italy) and performed a laboratory experiment to test the effect of OA on P. oceanica photosynthesis and its potential buffering capacity. At the study site east of Basiluzzo Islet, venting of CO2 gas was controlled by tides, resulting in an average pH difference of 0.1 between the vent and reference site. P. oceanica shoot and leaf density was unaffected by these levels of OA, although shorter leaves at the vent site suggest increased susceptibility to erosion, potentially by herbivores. The community of sessile epibionts differed in composition and was characterized by a higher species richness at the vent site, though net epiphytic calcium carbonate concentration was similar. These findings suggest a higher ecosystem complexity at the vent site, which may have facilitated the higher diversity of copepods in the otherwise unaffected motile epibiont community. In the laboratory experiment, P. oceanica photosynthesis increased with decreasing pHT (7.6, 6.6, 5.5), which induced an elevated pH at the leaf surfaces of up to 0.5 units compared to the ambient seawater pHT of 6.6. This suggests a temporary pH buffering in the diffusive boundary layer of leaves, which could be favorable for epibiont organisms. The results of this multispecies study contribute to understanding community-level responses and underlying processes in long-term acidified conditions. Increased replication and monitoring of physico-chemical parameters on an annual scale are, however, recommended to assure that the biological responses observed during a short period reflect long-term dynamics of these parameters. PMID:28792960

Repopulation of the fibrotic/cirrhotic rat liver by transplanted hepatic stem/progenitor cells and mature hepatocytes

PubMed Central

Yovchev, Mladen I.; Xue, Yuhua; Shafritz, David A.; Locker, Joseph; Oertel, Michael

2013-01-01

Background & Aim Considerable progress has been made in developing anti-fibrotic agents and other strategies to treat liver fibrosis; however, significant long-term restoration of functional liver mass has not yet been achieved. Therefore, we investigated whether transplanted hepatic stem/progenitor cells can effectively repopulate the liver with advanced fibrosis/cirrhosis. Methods Stem/progenitor cells derived from fetal livers or mature hepatocytes from DPPIV+ F344 rats were transplanted into DPPIV− rats with thioacetamide (TAA)-induced fibrosis/cirrhosis; rats were sacrificed 1, 2, or 4 months later. Liver tissues were analyzed by histochemistry, hydroxyproline determination, RT-PCR, and immunohistochemistry. Results After chronic TAA administration, DPPIV− F344 rats exhibited progressive fibrosis, cirrhosis and severe hepatocyte damage. Besides stellate cell activation, increased numbers of stem/progenitor cells (Dlk-1+, AFP+, CD133+, Sox-9+, FoxJ1+) were observed. In conjunction with partial hepatectomy (PH), transplanted stem/progenitor cells engrafted, proliferated competitively compared to host hepatocytes, differentiated into hepatocytic and biliary epithelial cells, and generated new liver mass with extensive long-term liver repopulation (40.8 ± 10.3%). Remarkably, more than 20% liver repopulation was achieved in the absence of PH, associated with reduced fibrogenic activity (e.g., expression of α-SMA, PDGFRβ, desmin, vimentin, TIMP1) and fibrosis (reduced collagen). Furthermore, hepatocytes can also replace liver mass with advanced fibrosis/cirrhosis, but to a lesser extent than FLSPCs. Conclusions This study is a Proof of Principle demonstration that transplanted epithelial stem/progenitor cells can restore injured parenchyma in a liver environment with advanced fibrosis/cirrhosis and exhibit anti-fibrotic effects. PMID:23840008

The Long-Term Conditions Questionnaire: conceptual framework and item development.

PubMed

Peters, Michele; Potter, Caroline M; Kelly, Laura; Hunter, Cheryl; Gibbons, Elizabeth; Jenkinson, Crispin; Coulter, Angela; Forder, Julien; Towers, Ann-Marie; A'Court, Christine; Fitzpatrick, Ray

2016-01-01

To identify the main issues of importance when living with long-term conditions to refine a conceptual framework for informing the item development of a patient-reported outcome measure for long-term conditions. Semi-structured qualitative interviews (n=48) were conducted with people living with at least one long-term condition. Participants were recruited through primary care. The interviews were transcribed verbatim and analyzed by thematic analysis. The analysis served to refine the conceptual framework, based on reviews of the literature and stakeholder consultations, for developing candidate items for a new measure for long-term conditions. Three main organizing concepts were identified: impact of long-term conditions, experience of services and support, and self-care. The findings helped to refine a conceptual framework, leading to the development of 23 items that represent issues of importance in long-term conditions. The 23 candidate items formed the first draft of the measure, currently named the Long-Term Conditions Questionnaire. The aim of this study was to refine the conceptual framework and develop items for a patient-reported outcome measure for long-term conditions, including single and multiple morbidities and physical and mental health conditions. Qualitative interviews identified the key themes for assessing outcomes in long-term conditions, and these underpinned the development of the initial draft of the measure. These initial items will undergo cognitive testing to refine the items prior to further validation in a survey.

Electrochemistry and dissolution kinetics of magnetite and ilmenite

USGS Publications Warehouse

White, A.F.; Peterson, M.L.; Hochella, M.F.

1994-01-01

Natural samples of magnetite and ilmenite were experimentally weathered in pH 1-7 anoxic solutions at temperatures of 2-65 ??C. Reaction of magnetite is described as [Fe2+Fe23+]O4(magnetite) + 2H+ ??? ??[Fe23+]O3(maghemite) + Fe2+ + H2O. Dynamic polarization experiments using magnetite electrodes confirmed that this reaction is controlled by two electrochemical half cells, 3[Fe2+Fe23+]O4(magnetite) ??? 4??[Fe23+]O3(maghemite) + Fe2+ + 2e- and [Fe2+Fe23+]O4(magnetite) + 8 H+ + 2e- ??? 3Fe2+ + 4H2O, which result in solid state Fe3+ reduction, formation of an oxidized layer and release of Fe(II) to solution. XPS data revealed that iron is present in the ferric state in the surfaces of reacted magnetite and ilmenite and that the Ti Fe ratio increased with reaction pH for ilmenite. Short-term (<36 h) release rates of Fe(II) were linear with time. Between pH 1 and 7, rates varied between 0.3 and 13 ?? 10-14 mol ?? cm-2 ?? s-1 for magnetite and 0.05 and 12.3 ?? 10-14 mol ?? cm-2 ?? s-1 for ilmenite. These rates are two orders of magnitude slower than electrochemical rates determined by Tafel and polarization resistance measurements. Discrepancies are due to both differences in geometric and BET surface area estimates and in the oxidation state of the mineral surface. In long-term closed-system experiments (<120 days), Fe(II) release slowed with time due to the passivation of the surfaces by increasing thicknesses of oxide surface layers. A shrinking core model, coupling surface reaction and diffusion transport, predicted that at neutral pH, the mean residence time for sand-size grains of magnetite and ilmenite will exceed 107 years. This agrees with long-term stability of these oxides in the geologic record. ?? 1994.

Evolutionary engineering reveals divergent paths when yeast is adapted to different acidic environments.

PubMed

Fletcher, Eugene; Feizi, Amir; Bisschops, Markus M M; Hallström, Björn M; Khoomrung, Sakda; Siewers, Verena; Nielsen, Jens

2017-01-01

Tolerance of yeast to acid stress is important for many industrial processes including organic acid production. Therefore, elucidating the molecular basis of long term adaptation to acidic environments will be beneficial for engineering production strains to thrive under such harsh conditions. Previous studies using gene expression analysis have suggested that both organic and inorganic acids display similar responses during short term exposure to acidic conditions. However, biological mechanisms that will lead to long term adaptation of yeast to acidic conditions remains unknown and whether these mechanisms will be similar for tolerance to both organic and inorganic acids is yet to be explored. We therefore evolved Saccharomyces cerevisiae to acquire tolerance to HCl (inorganic acid) and to 0.3M L-lactic acid (organic acid) at pH 2.8 and then isolated several low pH tolerant strains. Whole genome sequencing and RNA-seq analysis of the evolved strains revealed different sets of genome alterations suggesting a divergence in adaptation to these two acids. An altered sterol composition and impaired iron uptake contributed to HCl tolerance whereas the formation of a multicellular morphology and rapid lactate degradation was crucial for tolerance to high concentrations of lactic acid. Our findings highlight the contribution of both the selection pressure and nature of the acid as a driver for directing the evolutionary path towards tolerance to low pH. The choice of carbon source was also an important factor in the evolutionary process since cells evolved on two different carbon sources (raffinose and glucose) generated a different set of mutations in response to the presence of lactic acid. Therefore, different strategies are required for a rational design of low pH tolerant strains depending on the acid of interest. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Development and validation of a stability-indicating high performance liquid chromatographic assay for benoxinate.

PubMed

Chorny, Michael; Levy, Daniel; Schumacher, Ilana; Lichaa, Chaim; Gruzman, Boris; Livshits, Oleg; Lomnicky, Yossi

2003-04-24

Benoxinate is a local anaesthetic used for ophthalmic applications. The aim of this study was to develop a rapid and simple stability-indicating method for the determination of benoxinate formulated for ophthalmic use, evaluate its long-term stability and identify its major degradation product. Benoxinate was eluted on a 10 microm Spherisorb phenyl column, 250 x 3.2 mm, with a mobile phase consisting of acetonitrile-buffer (pH 3.5) (35:65, v/v), pumped at 0.8 ml min(-1) flow rate. The buffer was composed of sodium dihydrogen phosphate (50 mM), sodium hydrogen sulfate (2.5 mM) and 1-heptanesulfonic acid sodium salt (5 mM). The analyte was quantified spectrophotometrically at 308 nm. The chromatograms of benoxinate formulations obtained by this method showed benoxinate (t = 4.5 min) well resolved from its degradation product (t = 2.3 min), which was separately identified by means of HPLC-MS as 4-amino-3-butoxybenzoic acid. The assay was demonstrated to have high accuracy, precision and linearity. The method was implemented in investigating the long-term stability of benoxinate 0.4% ophthalmic solutions. The method was found to be simple, quick and selective in determining benoxinate concentrations in fresh and aged preparations.

Automated pH Control of Nutrient Solution in a Hydroponic Plant Growth System

NASA Technical Reports Server (NTRS)

Smith, B.; Dogan, N.; Aglan, H.; Mortley, D.; Loretan, P.

1998-01-01

Over, the years, NASA has played an important role in providing to and the development of automated nutrient delivery and monitoring, systems for growing crops hydroponically for long term space missions. One example are the systems used in the Biomass Production Chamber (BPC) at Kennedy Space Center (KSC). The current KSC monitoring system is based on an engineering workstation using standard analog/digital input/output hardware and custom written software. The monitoring system uses completely separate sensors to provide a check of control sensor accuracy and has the ability to graphically display and store data form past experiment so that they are available for data analysis [Fortson, 1992]. In many cases, growing systems have not been fitted with the kind of automated control systems as used at KSC. The Center for Food and Environmental Systems for Human Exploration of Space (CFESH) located on the campus of Tuskegee University, has effectively grown sweetpotatoes and peanuts hydroponically for the past five years. However they have adjusted the pH electrical conductivity and volume of the hydroponic nutrient solution only manually at times when the solution was to be replenished or changed out according to its protocol (e.g. one-week, two-week, or two-day cycle). But the pH of the nutrient solution flowing through the channel is neither known nor controlled between the update, change out, or replenishment period. Thus, the pH of the nutrient solution is not held at an optimum level over the span of the plant's growth cycle. To solve this dilemma, an automated system for the control and data logging of pH data relative to sweetpotato production using the nutrient film technique (NFT) has been developed, This paper discusses a microprocessor-based system, which was designed to monitor, control, and record the pH of a nutrient solution used for growing sweetpotatoes using NFT.

Thin-film microextraction coupled to LC-ESI-MS/MS for determination of quaternary ammonium compounds in water samples.

PubMed

Boyacı, Ezel; Sparham, Chris; Pawliszyn, Janusz

2014-01-01

The dual nature of the quaternary ammonium compounds, having permanently charged hydrophilic quaternary ammonium heads and long-chain hydrophobic tails, makes the sample preparation step and analysis of these compounds challenging. A high-throughput method based on thin-film solid-phase microextraction (SPME) and liquid chromatography mass spectrometry was developed for simultaneous quantitative analysis of nine benzylic and aliphatic quaternary ammonium compounds. Chromatographic separation and detection of analytes were obtained in reverse-phase mode in 8 min using a triple quadrupole mass spectrometer. Hydrophilic lipophilic balance particle-coated blades were found to be the most suitable among the different coatings tested in terms of recoveries and carryover on the blades. For desorption solvents, 70/30, v/v (A/B) with 0.1 % formic acid (where A is 10 mM ammonium acetate in acetonitrile/water (95/5 , v/v) and B is 0.1 %  (v/v) formic acid in isopropyl alcohol) was shown to be the most efficient solvent for the desorption of the analytes from the SPME sorbent. The SPME method was optimised in terms of extraction, pH, and preconditioning, as well as extraction and desorption times. Optimum conditions were 45 min of extraction time and 15 min of desorption time, all with agitation. The extraction was found to be optimum in a range of pH 6.0 to 8.0, which is consistent with the natural pH of water samples. Wide linear dynamic ranges with the developed method were obtained for each compound, enabling the application of the method for a wide range of concentrations. The developed method was validated according to the Food and Drug Administration criteria. The proposed method is the first SPME-based approach describing the applicability of the high-throughput thin-film SPME in a 96-well system for analysis of such challenging compounds.

Physical and antimicrobial properties of thyme oil emulsions stabilized by ovalbumin and gum arabic.

PubMed

Niu, Fuge; Pan, Weichun; Su, Yujie; Yang, Yanjun

2016-12-01

Natural biopolymer stabilized oil-in-water emulsions were formulated using ovalbumin (OVA), gum arabic (GA) solutions and their complexes. The influence of interfacial structure of emulsion (OVA-GA bilayer and OVA/GA complexes emulsions) on the physical properties and antimicrobial activity of thyme oil (TO) emulsion against Escherichia coli (E. coli) was evaluated. The results revealed that the two types of emulsions with different oil phase compositions remained stable during a long storage period. The oil phase composition had an appreciable influence on the mean particle diameter and retention of the TO emulsions. The stable emulsion showed a higher minimum inhibitory concentration (MIC), and the TO emulsions showed an improved long-term antimicrobial activity compared to the pure thyme oil, especially complexes emulsion at pH 4.0. These results provided useful information for developing protection and delivery systems for essential oil using biopolymer. Copyright © 2016 Elsevier Ltd. All rights reserved.

Three-decade long fertilization-induced soil organic carbon sequestration depends on edaphic characteristics in six typical croplands

PubMed Central

Liang, Feng; Li, Jianwei; Yang, Xueyun; Huang, Shaomin; Cai, Zejiang; Gao, Hongjun; Ma, Junyong; Cui, Xian; Xu, Minggang

2016-01-01

Fertilizations affect soil organic carbon (SOC) content but the relative influences of the edaphic and climate factors on SOC storage are rarely studied across wide spatiotemporal scales. This study synthesized long-term datasets of fertilization experiments in six typical Chinese croplands, and calculated annual C input from crops and manure amendments, changes in SOC storage (ΔSOC) and C sequestration efficiency (i.e. the percentage of soil C change per unit of C input, hereafter referred as CSE) in 0–20 cm soil over three decades. Three fertilization treatments include no fertilization (CK), chemical nitrogen, phosphorus and potassium fertilizers (NPK) and combined chemical fertilizers and manure (NPKM). Results showed significant fertilization effects on C input and ΔSOC (NPKM>NPK>CK), and significantly higher CSE in Qiyang at Hunan than Zhengzhou at Henan and Heihe at Heilongjiang. The variance partitioning analysis (VPA) showed more variance of CSE can be explained by edaphic factors (up to 39.7%) than other factors. Furthermore, soil available N content and pH were identified as the major soil properties explaining CSE variance. This study demonstrated key controls of soil fertility factors on SOC sequestration and informs the need to develop strategic soil management plan to promote soil carbon sequestration under long-term intensive fertilization. PMID:27492771

Three-decade long fertilization-induced soil organic carbon sequestration depends on edaphic characteristics in six typical croplands

NASA Astrophysics Data System (ADS)

Liang, Feng; Li, Jianwei; Yang, Xueyun; Huang, Shaomin; Cai, Zejiang; Gao, Hongjun; Ma, Junyong; Cui, Xian; Xu, Minggang

2016-08-01

Fertilizations affect soil organic carbon (SOC) content but the relative influences of the edaphic and climate factors on SOC storage are rarely studied across wide spatiotemporal scales. This study synthesized long-term datasets of fertilization experiments in six typical Chinese croplands, and calculated annual C input from crops and manure amendments, changes in SOC storage (ΔSOC) and C sequestration efficiency (i.e. the percentage of soil C change per unit of C input, hereafter referred as CSE) in 0-20 cm soil over three decades. Three fertilization treatments include no fertilization (CK), chemical nitrogen, phosphorus and potassium fertilizers (NPK) and combined chemical fertilizers and manure (NPKM). Results showed significant fertilization effects on C input and ΔSOC (NPKM>NPK>CK), and significantly higher CSE in Qiyang at Hunan than Zhengzhou at Henan and Heihe at Heilongjiang. The variance partitioning analysis (VPA) showed more variance of CSE can be explained by edaphic factors (up to 39.7%) than other factors. Furthermore, soil available N content and pH were identified as the major soil properties explaining CSE variance. This study demonstrated key controls of soil fertility factors on SOC sequestration and informs the need to develop strategic soil management plan to promote soil carbon sequestration under long-term intensive fertilization.

Three-decade long fertilization-induced soil organic carbon sequestration depends on edaphic characteristics in six typical croplands.

PubMed

Liang, Feng; Li, Jianwei; Yang, Xueyun; Huang, Shaomin; Cai, Zejiang; Gao, Hongjun; Ma, Junyong; Cui, Xian; Xu, Minggang

2016-08-05

Fertilizations affect soil organic carbon (SOC) content but the relative influences of the edaphic and climate factors on SOC storage are rarely studied across wide spatiotemporal scales. This study synthesized long-term datasets of fertilization experiments in six typical Chinese croplands, and calculated annual C input from crops and manure amendments, changes in SOC storage (ΔSOC) and C sequestration efficiency (i.e. the percentage of soil C change per unit of C input, hereafter referred as CSE) in 0-20 cm soil over three decades. Three fertilization treatments include no fertilization (CK), chemical nitrogen, phosphorus and potassium fertilizers (NPK) and combined chemical fertilizers and manure (NPKM). Results showed significant fertilization effects on C input and ΔSOC (NPKM>NPK>CK), and significantly higher CSE in Qiyang at Hunan than Zhengzhou at Henan and Heihe at Heilongjiang. The variance partitioning analysis (VPA) showed more variance of CSE can be explained by edaphic factors (up to 39.7%) than other factors. Furthermore, soil available N content and pH were identified as the major soil properties explaining CSE variance. This study demonstrated key controls of soil fertility factors on SOC sequestration and informs the need to develop strategic soil management plan to promote soil carbon sequestration under long-term intensive fertilization.

Development of the Glass Electrode and the pH Response

ERIC Educational Resources Information Center

Graham, Daniel J.; Jaselskis, Bruno; Moore, Carl E.

2013-01-01

The glass electrode is the most commonly used device to access the pH of an aqueous solution. It attains highly accurate measurements via simple and well-established procedures. However, the reasons why the glass electrode potential scales with hydrogen ion concentration according to almost Nernstian potential values have been long-standing…

Physiological compensation for environmental acidification is limited in the deep-sea urchin Strongylocentrotus fragilis

NASA Astrophysics Data System (ADS)

Taylor, J. R.; Lovera, C.; Whaling, P. J.; Buck, K. R.; Pane, E. F.; Barry, J. P.

2013-05-01

Anthropogenic CO2 is now reaching depths over 1000 m in the Eastern Pacific, overlapping the Oxygen Minimum Zone (OMZ). Deep-sea animals - particularly, calcifiers - are suspected to be especially sensitive to environmental acidification associated with global climate change. We have investigated the effects of hypercapnia and hypoxia on the deep-sea urchin Strongylocentrotus fragilis, during two long-term exposure experiments (1 month and 4 month) at three levels of reduced pH at in situ O2 levels of approx. 10% saturation, and also to control pH at 100% O2 saturation. During the first experiment, internal acid-base balance was investigated during a one-month exposure; results show S. fragilis has limited ability to compensate for the respiratory acidosis brought on by reduced pH, due in part to low non-bicarbonate extracellular fluid buffering capacity. During the second experiment, longer-term effects of hypercapnia and variable O2 on locomotion, feeding, growth, and gonadosomatic index (GSI) were investigated; results show significant mortality and correlation of all measured parameters with environmental acidification at pH 6.6. Transient adverse effects on locomotion and feeding were seen at pH 7.2, without compromise of growth or GSI. Based on the expected changes in ocean pH and oxygen, results suggest extinction of S. fragilis in the eastern North Pacific is unlikely. Rather, we expect a shoaling and contraction of its bathymetric range.

Stability of a pH-sensitive polymer matrix

DOE Office of Scientific and Technical Information (OSTI.GOV)

Northrup, M.A.; Langry, K.; Angel, S.M.

1990-03-01

A ratiometric pH-sensitive fluorescent dye (hydroxypyrenetrisulfonic acid) was covalently attached to an acrylamide polymer. These pH-sensitive copolymers were either covalently bonded to the end of an optical fiber or polymerized into separate gels. Long-term, accelerated aging studies were performed on the fibers and gels in 43{degree}C distilled H{sub 2}O. The fiber-immobilized optrodes gave good pH responses for up to 2 months. The pH-sensitive gels were physically attached to optical fibers and gave very good pH responses for over one year. These physically immobilized, one-year-old, pH-sensitive copolymers provided optrodes with linear pH responses between pH 6 and 8 and resolution greatermore » than 0.25 pH unit. A simple photostability experiment on these optrodes showed that they were very photostable. The results of this study indicate that pH-sensitive copolymers in a simple optrode design can be employed as pH sensors with useful lifetimes exceeding one year. 11 refs., 6 figs.« less

Effects of ocean acidification on the shells of four Mediterranean gastropod species near a CO2 seep.

PubMed

Duquette, Ashley; McClintock, James B; Amsler, Charles D; Pérez-Huerta, Alberto; Milazzo, Marco; Hall-Spencer, Jason M

2017-11-30

Marine CO 2 seeps allow the study of the long-term effects of elevated pCO 2 (ocean acidification) on marine invertebrate biomineralization. We investigated the effects of ocean acidification on shell composition and structure in four ecologically important species of Mediterranean gastropods (two limpets, a top-shell snail, and a whelk). Individuals were sampled from three sites near a volcanic CO 2 seep off Vulcano Island, Italy. The three sites represented ambient (8.15pH), moderate (8.03pH) and low (7.73pH) seawater mean pH. Shell mineralogy, microstructure, and mechanical strength were examined in all four species. We found that the calcite/aragonite ratio could vary and increased significantly with reduced pH in shells of one of the two limpet species. Moreover, each of the four gastropods displayed reductions in either inner shell toughness or elasticity at the Low pH site. These results suggest that near-future ocean acidification could alter shell biomineralization and structure in these common gastropods. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Production Rate and Employment of Ph.D. Astronomers

NASA Astrophysics Data System (ADS)

Metcalfe, Travis S.

2008-02-01

In an effort to encourage self-regulation of the astronomy job market, I examine the supply of, and demand for, astronomers over time. On the supply side, I document the production rate of Ph.D. astronomers from 1970 to 2006 using the UMI Dissertation Abstracts database, along with data from other independent sources. I compare the long-term trends in Ph.D. production with federal astronomy research funding over the same time period, and I demonstrate that additional funding is correlated with higher subsequent Ph.D. production. On the demand side, I monitor the changing patterns of employment using statistics about the number and types of jobs advertised in the AAS Job Register from 1984 to 2006. Finally, I assess the sustainability of the job market by normalizing this demand by the annual Ph.D. production. The most recent data suggest that there are now annual advertisements for about one postdoctoral job, half a faculty job, and half a research/support position for every new domestic Ph.D. recipient in astronomy and astrophysics. The average new astronomer might expect to hold up to 3 jobs before finding a steady position.

Spatial distribution of ammonium and calcium in optimally fertilized pine plantation soils

Treesearch

Ivan Edwards; Andrew Gillespie; Jennifer Chen; Kurt Johnsen; Ronald Turco

2005-01-01

Commercial timber production is increasingly reliant on long-term fertilization to maximize stand productivity, yet we do not understand the extent to which this practice homogenizes soil properties. The effects of 16 yr of optimal fertilization and optimal fertilization with irrigation (fertigation) on forest floor depth, pH, total organic carbon (TOC) and total...

Soil pH and exchangeable cation responses to tillage and fertilizer in dryland cropping systems

USDA-ARS?s Scientific Manuscript database

Long-term use of nitrogen (N) fertilizers can lead to soil acidification and other chemical changes that can lower fertility. Here, we present near-surface (0-7.6 cm) soil chemistry data from 16 years of two different crop rotations in the US northern Great Plains: (1) continuous crop (CC; spring w...

Solubility of lead and copper in biochar-amended small arms range soils: influence of soil organic carbon and pH

USDA-ARS?s Scientific Manuscript database

In situ application of heavy metal stabilizing agents has in some cases increased the mobility of target metal contaminants. Mechanistic understandings are necessary to better predict (1) the dynamic short- and long-term response to soil amendments, and (2) the utility of biochars in nonremoval and...

Remediation of Stratified Soil Acidity Through Surface Application of Lime in No-Till Cropping Systems

USDA-ARS?s Scientific Manuscript database

Yield reduction and reduced crop vigor, resulting from soil acidification, are of increasing concern in eastern Washington and northern Idaho. In this region, soil pH has been decreasing at an accelerated rate, primarily due to the long-term use of ammonium based fertilizers. In no-till systems, the...

Selection harvests in Amazonian rainforests: long-term impacts on soil properties

Treesearch

K.L. McNabb; M.S. Miller; B.G. Lockaby; B.J. Stokes; R.G. Clawson; John A. Stanturf; J.N.M. Silva

1997-01-01

Surface soil properties were compared among disturbance classes associated with a single-tree selection harvest study installed in 1979 in the Brazilian Amazon. Response variables included pH, total N, total organic C, extractable P, exchangeable K, Ca, Mg, and bulk density. In general, concentrations of all elements displayed residual effects 16 years after harvests...

The Long-Term Conditions Questionnaire: conceptual framework and item development

PubMed Central

Peters, Michele; Potter, Caroline M; Kelly, Laura; Hunter, Cheryl; Gibbons, Elizabeth; Jenkinson, Crispin; Coulter, Angela; Forder, Julien; Towers, Ann-Marie; A’Court, Christine; Fitzpatrick, Ray

2016-01-01

Purpose To identify the main issues of importance when living with long-term conditions to refine a conceptual framework for informing the item development of a patient-reported outcome measure for long-term conditions. Materials and methods Semi-structured qualitative interviews (n=48) were conducted with people living with at least one long-term condition. Participants were recruited through primary care. The interviews were transcribed verbatim and analyzed by thematic analysis. The analysis served to refine the conceptual framework, based on reviews of the literature and stakeholder consultations, for developing candidate items for a new measure for long-term conditions. Results Three main organizing concepts were identified: impact of long-term conditions, experience of services and support, and self-care. The findings helped to refine a conceptual framework, leading to the development of 23 items that represent issues of importance in long-term conditions. The 23 candidate items formed the first draft of the measure, currently named the Long-Term Conditions Questionnaire. Conclusion The aim of this study was to refine the conceptual framework and develop items for a patient-reported outcome measure for long-term conditions, including single and multiple morbidities and physical and mental health conditions. Qualitative interviews identified the key themes for assessing outcomes in long-term conditions, and these underpinned the development of the initial draft of the measure. These initial items will undergo cognitive testing to refine the items prior to further validation in a survey. PMID:27621678

Urbanization accelerates long-term salinization and alkalinization of fresh water

NASA Astrophysics Data System (ADS)

Kaushal, S.; Duan, S.; Doody, T.; Haq, S.; Smith, R. M.; Newcomer Johnson, T. A.; Delaney Newcomb, K.; Gorman, J. K.; Bowman, N.; Mayer, P. M.; Wood, K. L.; Belt, K.; Stack, W.

2017-12-01

Human dominated land-use increases transport a major ions in streams due to anthropogenic salts and accelerated weathering. We show long-term trends in calcium, magnesium, sodium, alkalinity, and hardness over 50 years in the Baltimore metropolitan region and elsewhere. We also examine how major ion concentrations have increased significantly with impervious surface cover in watersheds across land use. Base cations show strong relationships with acid anions, which illustrates the coupling of major biogeochemical cycles in urban watersheds over time. Longitudinal patterns in major ions can also show increasing trends from headwaters to coastal waters, which suggests coupled biogeochemical cycles over space. We present new results from manipulative experiments and long-term monitoring across different urban regions regarding patterns and processes of salinization and alkalinization. Overall, our work demonstrates that urbanization dramatically increases major ions, ionic strength, and pH over decades from headwaters to coastal waters, which impacts the integrity of aquatic life, infrastructure, drinking water, and coastal ocean alkalinization.

Regularities in Low-Temperature Phosphatization of Silicates

NASA Astrophysics Data System (ADS)

Savenko, A. V.

2018-01-01

The regularities in low-temperature phosphatization of silicates are defined from long-term experiments on the interaction between different silicate minerals and phosphate-bearing solutions in a wide range of medium acidity. It is shown that the parameters of the reaction of phosphatization of hornblende, orthoclase, and labradorite have the same values as for clayey minerals (kaolinite and montmorillonite). This effect may appear, if phosphotization proceeds, not after silicate minerals with a different structure and composition, but after a secondary silicate phase formed upon interaction between silicates and water and stable in a certain pH range. Variation in the parameters of the reaction of phosphatization at pH ≈ 1.8 is due to the stability of the silicate phase different from that at higher pH values.

Issues in the Development of Long Term Care Gerontology Centers: The Centers Concept. Selected Topics in Long Term Care. Volume 6.

ERIC Educational Resources Information Center

Mortenson, Lee E.; Berdes, Celia M.

This document, one in a series developed to provide technical assistance to 22 Long-Term Care Gerontology Centers, describes the current administrative and structural phenomenon of these centers. Precedents useful in assessing both the current climate and actual prospects for development of long term care centers are cited. The first section…

Chronic exposure to combined carcinogens enhances breast cell carcinogenesis with mesenchymal and stem-like cell properties.

PubMed

Pluchino, Lenora Ann; Wang, Hwa-Chain Robert

2014-01-01

Breast cancer is the most common type of cancer affecting women in North America and Europe. More than 85% of breast cancers are sporadic and attributable to long-term exposure to small quantities of multiple carcinogens. To understand how multiple carcinogens act together to induce cellular carcinogenesis, we studied the activity of environmental carcinogens 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and benzo[a]pyrene (B[a]P), and dietary carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) using our breast cell carcinogenesis model. Our study revealed, for the first time, that combined NNK and B[a]P enhanced breast cell carcinogenesis chronically induced by PhIP in both non-cancerous and cancerous breast cells. Co-exposure was more potent than sequential exposure to combined NNK and B[a]P followed by PhIP in inducing carcinogenesis. Initiation of carcinogenesis was measured by transient endpoints induced in a single exposure, while progression of carcinogenesis was measured by acquisition of constitutive endpoints in cumulative exposures. Transient endpoints included DNA damage, Ras-Erk-Nox pathway activation, reactive oxygen species elevation, and increased cellular proliferation. Constitutive endpoints included various cancer-associated properties and signaling modulators, as well as enrichment of cancer stem-like cell population and activation of the epithelial-to-mesenchymal transition program. Using transient and constitutive endpoints as targets, we detected that a combination of the green tea catechins ECG and EGCG, at non-cytotoxic levels, was more effective than individual agents in intervention of cellular carcinogenesis induced by combined NNK, B[a]P, and PhIP. Thus, use of combined ECG and EGCG should be seriously considered for early intervention of breast cell carcinogenesis associated with long-term exposure to environmental and dietary carcinogens.

Chronic Exposure to Combined Carcinogens Enhances Breast Cell Carcinogenesis with Mesenchymal and Stem-Like Cell Properties

PubMed Central

Pluchino, Lenora Ann; Wang, Hwa-Chain Robert

2014-01-01

Breast cancer is the most common type of cancer affecting women in North America and Europe. More than 85% of breast cancers are sporadic and attributable to long-term exposure to small quantities of multiple carcinogens. To understand how multiple carcinogens act together to induce cellular carcinogenesis, we studied the activity of environmental carcinogens 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and benzo[a]pyrene (B[a]P), and dietary carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) using our breast cell carcinogenesis model. Our study revealed, for the first time, that combined NNK and B[a]P enhanced breast cell carcinogenesis chronically induced by PhIP in both non-cancerous and cancerous breast cells. Co-exposure was more potent than sequential exposure to combined NNK and B[a]P followed by PhIP in inducing carcinogenesis. Initiation of carcinogenesis was measured by transient endpoints induced in a single exposure, while progression of carcinogenesis was measured by acquisition of constitutive endpoints in cumulative exposures. Transient endpoints included DNA damage, Ras-Erk-Nox pathway activation, reactive oxygen species elevation, and increased cellular proliferation. Constitutive endpoints included various cancer-associated properties and signaling modulators, as well as enrichment of cancer stem-like cell population and activation of the epithelial-to-mesenchymal transition program. Using transient and constitutive endpoints as targets, we detected that a combination of the green tea catechins ECG and EGCG, at non-cytotoxic levels, was more effective than individual agents in intervention of cellular carcinogenesis induced by combined NNK, B[a]P, and PhIP. Thus, use of combined ECG and EGCG should be seriously considered for early intervention of breast cell carcinogenesis associated with long-term exposure to environmental and dietary carcinogens. PMID:25372613

Dynamic patterns and ecological impacts of declining ocean pH in a high-resolution multi-year dataset.

PubMed

Wootton, J Timothy; Pfister, Catherine A; Forester, James D

2008-12-02

Increasing global concentrations of atmospheric CO(2) are predicted to decrease ocean pH, with potentially severe impacts on marine food webs, but empirical data documenting ocean pH over time are limited. In a high-resolution dataset spanning 8 years, pH at a north-temperate coastal site declined with increasing atmospheric CO(2) levels and varied substantially in response to biological processes and physical conditions that fluctuate over multiple time scales. Applying a method to link environmental change to species dynamics via multispecies Markov chain models reveals strong links between in situ benthic species dynamics and variation in ocean pH, with calcareous species generally performing more poorly than noncalcareous species in years with low pH. The models project the long-term consequences of these dynamic changes, which predict substantial shifts in the species dominating the habitat as a consequence of both direct effects of reduced calcification and indirect effects arising from the web of species interactions. Our results indicate that pH decline is proceeding at a more rapid rate than previously predicted in some areas, and that this decline has ecological consequences for near shore benthic ecosystems.

From municipal sewage to drinking water: fate and removal of pharmaceutical residues in the aquatic environment in urban areas.

PubMed

Heberer, Th; Reddersen, K; Mechlinski, A

2002-01-01

Recently, the occurrence and fate of pharmaceutically active compounds (PhACs) in the aquatic environment was recognized as one of the emerging issues in environmental chemistry and as a matter of public concern. Residues of PhACs have been found as contaminants in sewage, surface, and ground- and drinking water samples. Since June 2000, a new long-term monitoring program of sewage, surface, ground- and drinking water has been carried out in Berlin, Germany. Samples, collected periodically from selected sites in the Berlin area, are investigated for residues of PhACs and related contaminants. The purpose of this monitoring is to investigate these compounds over a long time period to get more reliable data on their occurrence and fate in the different aquatic compartments. Moreover, the surface water investigations allow the calculation of season-dependent contaminant loads in the Berlin waters. In the course of the monitoring program, PhACs and some other polar compounds were detected at concentrations up to the microg/L-level in all compartments of the Berlin water cycle. The monitoring is accompanied and supported by several other investigations such as laboratory column experiments and studies on bank filtration and drinking water treatment using conventional or membrane filtration techniques.

Reforming long-term care financing through insurance

PubMed Central

Meiners, Mark R.

1988-01-01

Until recently, insurance for long-term care was not viewed as feasible. This perception has changed dramatically in the past few years. Several models of long-term care insurance have begun to be tested. Although the application of insurance principles to long-term care is still new, the emergence of private market interest in developing long-term care insurance has been a catalyst to renewed public-policy support for reforming the way we pay for long-term care. States, in particular, have become interested in developing public-private partnerships to support the emergence of long-term care insurance that could help relieve the mounting pressure on Medicaid budgets. PMID:10312962

An African grassland responds similarly to long-term fertilization to the Park Grass experiment.

PubMed

Ward, David; Kirkman, Kevin; Tsvuura, Zivanai

2017-01-01

We compared the results of a long-term (65 years) experiment in a South African grassland with the world's longest-running ecological experiment, the Park Grass study at Rothamsted, U.K. The climate is warm and humid in South Africa and cool and temperate in England. The African grassland has been fertilized with two forms of nitrogen applied at four levels, phosphorus and lime in a crossed design in 96 plots. In 1951, about 84% of plant cover consisted of Themeda triandra, Tristachya leucothrix and Setaria nigrirostris. Currently, the dominant species are Panicum maximum, Setaria sphacelata and Eragrostis curvula, making up 71% of total biomass. As in the Park Grass experiment, we found a significant (additive) interaction effect on ANPP of nitrogen and phosphorus, and a (marginally significant) negative correlation between ANPP and species richness. Unlike the Park Grass experiment, there was no correlation between ANPP and species richness when pH was included as a covariate. There was also a significant negative effect of nitrogen amount and nitrogen form and a positive effect of lime on species richness and species diversity. Soil pH had an important effect on species richness. Liming was insufficient to balance the negative effects on species richness of nitrogen fertilization. There was a significant effect of pH on biomass of three abundant species. There were also significant effects of light on the biomass of four species, with only Panicum maximum having a negative response to light. In all of the abundant species, adding total species richness and ANPP to the model increased the amount of variance explained. The biomass of Eragrostis curvula and P. maximum were negatively correlated with species richness while three other abundant species increased with species richness, suggesting that competition and facilitation were active. Consistent with the results from the Park Grass and other long-term fertilization experiments of grasslands, we found a positive effect of soil pH and a negative effect of nitrogen amount on species richness, a more acutely negative effect on species richness of acidic ammonium sulphate fertilizer than limestone ammonium nitrate, a negative relationship between species richness and biomass, and a positive effect on species richness of lime interacting with nitrogen.

Impacts of ocean acidification on sea urchin growth across the juvenile to mature adult life-stage transition is mitigated by warming.

PubMed

Dworjanyn, Symon A; Byrne, Maria

2018-04-11

Understanding how growth trajectories of calcifying invertebrates are affected by changing climate requires acclimation experiments that follow development across life-history transitions. In a long-term acclimation study, the effects of increased acidification and temperature on survival and growth of the tropical sea urchin Tripneustes gratilla from the early juvenile (5 mm test diameter-TD) through the developmental transition to the mature adult (60 mm TD) were investigated. Juveniles were reared in a combination of three temperature and three pH/ p CO 2 treatments, including treatments commensurate with global change projections. Elevated temperature and p CO 2 /pH both affected growth, but there was no interaction between these factors. The urchins grew more slowly at pH 7.6, but not at pH 7.8. Slow growth may be influenced by the inability to compensate coelomic fluid acid-base balance at pH 7.6. Growth was faster at +3 and +6°C compared to that in ambient temperature. Acidification and warming had strong and interactive effects on reproductive potential. Warming increased the gonad index, but acidification decreased it. At pH 7.6 there were virtually no gonads in any urchins regardless of temperature. The T. gratilla were larger at maturity under combined near-future warming and acidification scenarios (+3°C/pH 7.8). Although the juveniles grew and survived in near-future warming and acidification conditions, chronic exposure to these stressors from an early stage altered allocation to somatic and gonad growth. In the absence of phenotypic adjustment, the interactive effects of warming and acidification on the benthic life phases of sea urchins may compromise reproductive fitness and population maintenance as global climatic change unfolds. © 2018 The Author(s).

Social scientist on board in long-term management of high level and/or long-lived radioactive waste in Belgium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parotte, C.

In Belgium, the long-term management of radioactive waste is under the exclusive competence of the Belgian Agency for Radioactive Waste and Enriched Fissile Materials (knew as ONDRAF/NIRAS). Unlike low-level waste, no institutional policy has yet been formally approved for the long-term management of high level and/or long-lived radioactive waste (knew as B and C waste). In this context, ONDRAF/NIRAS considers the public and stakeholders' participation as an essential factor in the formulation of an effective and legitimate policy. This is why it has decided to integrate them in different ways during the elaboration of the Waste Plan (ONDRAF/NIRAS-document containing guidelinesmore » to make a principled policy decision about nuclear waste management). To do so, social scientists have been regularly mobilized either as external evaluators, follow-up committee members, or participatory observants. Hence, the Waste Plan is only the first step in a long decision-making process. For a PhD student under contract with ONDRAF/NIRAS, this mandate consists of thinking out a way to construct an inter-organizational innovative communication system that would be participative, transparent and embedded in a long-term perspective, thus integrating all the further legal steps to take throughout the decision-making process. In this regard, two paradoxical constraints must be taken into account: on the one hand, my own influence on the legal decision-making process should remain limited, because of a series of constraints, lock-ins and previous decisions which have to be respected; on the other hand, ONDRAF/NIRAS expects the research conclusions to be policy relevant and useful. In this paper, the purpose is twofold. Firstly, the issues raised by this policy mandate is an opportunity to question the per-formative dimensions of the social scientist in the decision-making process and, more specifically, to have a reflexive view on our position as PhD Student. Secondly, assuming the role of 'embarked' social scientist, numerous of answers will discuss to face the different dilemmas of the researcher 'in action'. Those reflections follow on, among others, those from previous papers discussed in Quimper in April 2013 and in Leuven in June 2013. (authors)« less

Long-term grazing effects on vegetation characteristics and soil properties in a semiarid grassland, northern China.

PubMed

Zhang, Jing; Zuo, Xiaoan; Zhou, Xin; Lv, Peng; Lian, Jie; Yue, Xiyuan

2017-05-01

Understanding the responses of vegetation characteristics and soil properties to grazing disturbance is useful for grassland ecosystem restoration and management in semiarid areas. Here, we examined the effects of long-term grazing on vegetation characteristics, soil properties, and their relationships across four grassland types (meadow, Stipa steppe, scattered tree grassland, and sandy grassland) in the Horqin grassland, northern China. Our results showed that grazing greatly decreased vegetation cover, aboveground plant biomass, and root biomass in all four grassland types. Plant cover and aboveground biomass of perennials were decreased by grazing in all four grasslands, whereas grazing increased the cover and biomass of shrubs in Stipa steppe and of annuals in scattered tree grassland. Grazing decreased soil carbon and nitrogen content in Stipa steppe and scattered tree grassland, whereas soil bulk density showed the opposite trend. Long-term grazing significantly decreased soil pH and electrical conductivity (EC) in annual-dominated sandy grassland. Soil moisture in fenced and grazed grasslands decreased in the following order of meadow, Stipa steppe, scattered tree grassland, and sandy grassland. Correlation analyses showed that aboveground plant biomass was significantly positively associated with the soil carbon and nitrogen content in grazed and fenced grasslands. Species richness was significantly positively correlated with soil bulk density, moisture, EC, and pH in fenced grasslands, but no relationship was detected in grazed grasslands. These results suggest that the soil carbon and nitrogen content significantly maintains ecosystem function in both fenced and grazed grasslands. However, grazing may eliminate the association of species richness with soil properties in semiarid grasslands.

Low Cost Inkjet Printed Smart Bandage for Wireless Monitoring of Chronic Wounds

PubMed Central

Farooqui, Muhammad Fahad; Shamim, Atif

2016-01-01

Chronic wounds affect millions of patients around the world and their treatment is challenging as the early signs indicating their development are subtle. In addition, a type of chronic wound, known as pressure ulcer, develops in patients with limited mobility. Infection and frequent bleeding are indicators of chronic wound development. In this article, we present an unprecedented low cost continuous wireless monitoring system, realized through inkjet printing on a standard bandage, which can send early warnings for the parameters like irregular bleeding, variations in pH levels and external pressure at wound site. In addition to the early warnings, this smart bandage concept can provide long term wound progression data to the health care providers. The smart bandage comprises a disposable part which has the inkjet printed sensors and a reusable part constituting the wireless electronics. This work is an important step towards futuristic wearable sensors for remote health care applications. PMID:27353200

Low Cost Inkjet Printed Smart Bandage for Wireless Monitoring of Chronic Wounds

NASA Astrophysics Data System (ADS)

Farooqui, Muhammad Fahad; Shamim, Atif

2016-06-01

Chronic wounds affect millions of patients around the world and their treatment is challenging as the early signs indicating their development are subtle. In addition, a type of chronic wound, known as pressure ulcer, develops in patients with limited mobility. Infection and frequent bleeding are indicators of chronic wound development. In this article, we present an unprecedented low cost continuous wireless monitoring system, realized through inkjet printing on a standard bandage, which can send early warnings for the parameters like irregular bleeding, variations in pH levels and external pressure at wound site. In addition to the early warnings, this smart bandage concept can provide long term wound progression data to the health care providers. The smart bandage comprises a disposable part which has the inkjet printed sensors and a reusable part constituting the wireless electronics. This work is an important step towards futuristic wearable sensors for remote health care applications.

Low Cost Inkjet Printed Smart Bandage for Wireless Monitoring of Chronic Wounds.

PubMed

Farooqui, Muhammad Fahad; Shamim, Atif

2016-06-29

Chronic wounds affect millions of patients around the world and their treatment is challenging as the early signs indicating their development are subtle. In addition, a type of chronic wound, known as pressure ulcer, develops in patients with limited mobility. Infection and frequent bleeding are indicators of chronic wound development. In this article, we present an unprecedented low cost continuous wireless monitoring system, realized through inkjet printing on a standard bandage, which can send early warnings for the parameters like irregular bleeding, variations in pH levels and external pressure at wound site. In addition to the early warnings, this smart bandage concept can provide long term wound progression data to the health care providers. The smart bandage comprises a disposable part which has the inkjet printed sensors and a reusable part constituting the wireless electronics. This work is an important step towards futuristic wearable sensors for remote health care applications.

Consider long-term care as service alternative.

PubMed

Loria, L S

1987-04-01

The increasing demand for elderly care services, pressures on inpatient average length of stay and payment levels, and potential financial rewards from providing additional services, makes long-term care look attractive to hospitals. Long-term care, however, is not for every hospital. Before deciding to establish long-term care services, management should examine how the service fits within the hospital's strategic plan. The action plan below provides guidance in evaluating a decision to use hospital facilities for long-term care. Examine how long-term care services fit within the hospital's strategic plan. Study area demographics and competitors to assess the need and supply of long-term care services. Survey the medical staff, consumers and payers to determine attitudes, perceptions and interests regarding long-term care services. Develop a facility plan that identifies areas of excess capacity that can be most easily converted into long-term care with minimal effects on hospital operations. Prepare a financial feasibility analysis of the contribution margin and return on investment attributable to long-term care services. Include an impact analysis on hospital operations. Establish a management task force to develop a detailed implementation plan including assigned individual responsibilities and related timetable. Develop an effective marketing plan designed to generate increased patient market share.

Adaptation to low pH and lignocellulosic inhibitors resulting in ethanolic fermentation and growth of Saccharomyces cerevisiae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Narayanan, Venkatachalam; Sànchez i Nogué, Violeta; van Niel, Ed W. J.

Here, lignocellulosic bioethanol from renewable feedstocks using Saccharomyces cerevisiae is a promising alternative to fossil fuels owing to environmental challenges. S. cerevisiae is frequently challenged by bacterial contamination and a combination of lignocellulosic inhibitors formed during the pre-treatment, in terms of growth, ethanol yield and productivity. We investigated the phenotypic robustness of a brewing yeast strain TMB3500 and its ability to adapt to low pH thereby preventing bacterial contamination along with lignocellulosic inhibitors by short-term adaptation and adaptive lab evolution (ALE). The short-term adaptation strategy was used to investigate the inherent ability of strain TMB3500 to activate a robust phenotypemore » involving pre-culturing yeast cells in defined medium with lignocellulosic inhibitors at pH 5.0 until late exponential phase prior to inoculating them in defined media with the same inhibitor cocktail at pH 3.7. Adapted cells were able to grow aerobically, ferment anaerobically (glucose exhaustion by 19 +/- 5 h to yield 0.45 +/- 0.01 g ethanol g glucose -1) and portray significant detoxification of inhibitors at pH 3.7, when compared to non-adapted cells. ALE was performed to investigate whether a stable strain could be developed to grow and ferment at low pH with lignocellulosic inhibitors in a continuous suspension culture. Though a robust population was obtained after 3600 h with an ability to grow and ferment at pH 3.7 with inhibitors, inhibitor robustness was not stable as indicated by the characterisation of the evolved culture possibly due to phenotypic plasticity. With further research, this short-term adaptation and low pH strategy could be successfully applied in lignocellulosic ethanol plants to prevent bacterial contamination.« less

Adaptation to low pH and lignocellulosic inhibitors resulting in ethanolic fermentation and growth of Saccharomyces cerevisiae

DOE PAGES

Narayanan, Venkatachalam; Sànchez i Nogué, Violeta; van Niel, Ed W. J.; ...

2016-08-26

Here, lignocellulosic bioethanol from renewable feedstocks using Saccharomyces cerevisiae is a promising alternative to fossil fuels owing to environmental challenges. S. cerevisiae is frequently challenged by bacterial contamination and a combination of lignocellulosic inhibitors formed during the pre-treatment, in terms of growth, ethanol yield and productivity. We investigated the phenotypic robustness of a brewing yeast strain TMB3500 and its ability to adapt to low pH thereby preventing bacterial contamination along with lignocellulosic inhibitors by short-term adaptation and adaptive lab evolution (ALE). The short-term adaptation strategy was used to investigate the inherent ability of strain TMB3500 to activate a robust phenotypemore » involving pre-culturing yeast cells in defined medium with lignocellulosic inhibitors at pH 5.0 until late exponential phase prior to inoculating them in defined media with the same inhibitor cocktail at pH 3.7. Adapted cells were able to grow aerobically, ferment anaerobically (glucose exhaustion by 19 +/- 5 h to yield 0.45 +/- 0.01 g ethanol g glucose -1) and portray significant detoxification of inhibitors at pH 3.7, when compared to non-adapted cells. ALE was performed to investigate whether a stable strain could be developed to grow and ferment at low pH with lignocellulosic inhibitors in a continuous suspension culture. Though a robust population was obtained after 3600 h with an ability to grow and ferment at pH 3.7 with inhibitors, inhibitor robustness was not stable as indicated by the characterisation of the evolved culture possibly due to phenotypic plasticity. With further research, this short-term adaptation and low pH strategy could be successfully applied in lignocellulosic ethanol plants to prevent bacterial contamination.« less

Challenges of Supervising Part-Time PhD Students: Towards Student-Centred Practice

ERIC Educational Resources Information Center

Watts, Jacqueline H.

2008-01-01

The supervision of part-time doctoral students is a long-term academic enterprise requiring stamina both on the part of the supervisor and the student. Because of the fractured student identity of the part-time doctoral candidate, who is usually balancing a range of work, study, and family commitments, strategies to support their progress have to…

THE EFFECT OF LONG TERM WASTEWATER CROSS-CONNECTION'S EFFECT ON THE BIOFILM OF A SIMULATED WATER DISTRIBUTION SYSTEM

EPA Science Inventory

Under the current regulations (CFR 503), Class B biosolids may be land applied with certain site restrictions. One method for achieving Class B status is to raise the pH of the sludge to >12 for a minimum of 2 hours with an alkaline material (normally lime). Alternately, a Clas...

Psychological operations supporting counterinsurgency: 4th Psyop Group in Vietnam.

DTIC Science & Technology

2007-06-15

LTC Karl D . Zetmeir, MS. Accepted this 15th day of June 2007 by: , Director, Graduate Degree Programs Robert F. Baumann, Ph.D...APPENDIX C. PSYOP TASK ORGANIZATION.........................................................108 APPENDIX D . MAP OF PSYOP UNIT LOCATIONS...while Sandler’s is a more general long-term history of military PSYOP. Lieutenant Colonel Harry D . Latimer’s U.S. Psychological Operations in

Hydrogen ion input to the Hubbard Brook Experimental Forest, New Hampshire, during the last decade

Treesearch

Gene E. Likens; F. Herbert Bormann; John S. Eaton; Robert S. Pierce; Noye M. Johnson

1976-01-01

Being downwind of eastern and midwestern industrial centers, the Hubbard Brook Experimental Forest offers a prime location to monitor long-term trends in atmospheric chemistry. Continuous measurements of precipitation chemistry during the last 10 years provide a measure of recent changes in precipitation inputs of hydrogen ion. The weighted average pH of precipitation...

Layered Double Hydroxides: Potential Release-on-Demand Fertilizers for Plant Zinc Nutrition.

PubMed

López-Rayo, Sandra; Imran, Ahmad; Bruun Hansen, Hans Chr; Schjoerring, Jan K; Magid, Jakob

2017-10-11

A novel zinc (Zn) fertilizer concept based on Zn-doped layered double hydroxides (Zn-doped Mg-Fe-LDHs) has been investigated. Zn-doped Mg-Fe-LDHs were synthesized, their chemical composition was analyzed, and their nutrient release was studied in buffered solutions with different pH values. Uptake of Zn by barley (Hordeum vulgare cv. Antonia) was evaluated in short- (8 weeks), medium- (11 weeks), and long-term (28 weeks) experiments in quartz sand and in a calcareous soil enriched with Zn-doped Mg-Fe-LDHs. The Zn release rate of the Zn-doped Mg-Fe-LDHs was described by a first-order kinetics equation showing maximum release at pH 5.2, reaching approximately 45% of the total Zn content. The Zn concentrations in the plants receiving the LDHs were between 2- and 9.5-fold higher than those in plants without Zn addition. A positive effect of the LDHs was also found in soil. This work documents the long-term Zn release capacity of LDHs complying with a release-on-demand behavior and serves as proof-of-concept that Zn-doped Mg-Fe-LDHs can be used as Zn fertilizers.

Sorption, dissolution and pH determine the long-term equilibration and toxicity of coated and uncoated ZnO nanoparticles in soil.

PubMed

Waalewijn-Kool, Pauline L; Diez Ortiz, Maria; van Straalen, Nico M; van Gestel, Cornelis A M

2013-07-01

To assess the effect of long-term dissolution on bioavailability and toxicity, triethoxyoctylsilane coated and uncoated zinc oxide nanoparticles (ZnO-NP), non-nano ZnO and ZnCl2 were equilibrated in natural soil for up to twelve months. Zn concentrations in pore water increased with time for all ZnO forms but peaked at intermediate concentrations of ZnO-NP and non-nano ZnO, while for coated ZnO-NP such a clear peak only was seen after 12 months. Dose-related increases in soil pH may explain decreased soluble Zn levels due to fixation of Zn released from ZnO at higher soil concentrations. At T = 0 uncoated ZnO-NP and non-nano ZnO were equally toxic to the springtail Folsomia candida, but not as toxic as coated ZnO-NP, and ZnCl2 being most toxic. After three months equilibration toxicity to F. candida was already reduced for all Zn forms, except for coated ZnO-NP which showed reduced toxicity only after 12 months equilibration. Copyright © 2013 Elsevier Ltd. All rights reserved.

The effect of microstructural evolution on hardening behavior of type 17-4PH stainless steel in long-term aging at 350 deg. C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Jun; Zou Hong; Li Cong

2006-12-15

The effect of microstructural evolution on hardening behavior of 17-4PH stainless steel in long-term aging at 350 deg. C was studied by X-ray diffraction and transmission electron microscopy. The results showed that there is the matrix of lath martensite and nanometer-sized particles of {epsilon}-Cu precipitated from the matrix after the alloy is solution treated and tempered. When the alloy was aged 350 deg. C for 9 months, {alpha}-{alpha}' spinodal decomposition occurred along the grain boundaries and caused an increase in hardness which compensated for the weakening effect due to ripening of the {epsilon}-copper precipitates. Upon further aging to 12 months,more » the Cr-rich {alpha}'-phase and M{sub 23}C{sub 6} precipitated, both of which strengthened the alloy considerably and led to enhanced hardening despite the continued softening by overaging of the {epsilon}-copper precipitates. With the aging time extended to 15 months, substantial reversed austenite transformed and precipitation of the intermetallic G-phase occurred near the {epsilon}-Cu precipitates in the matrix. The abundant amount of reversed austenite that transformed led to rapid softening.« less

A Multi-Parametric Device with Innovative Solid Electrodes for Long-Term Monitoring of pH, Redox-Potential and Conductivity in a Nuclear Waste Repository

PubMed Central

Daoudi, Jordan; Betelu, Stephanie; Tzedakis, Theodore; Bertrand, Johan; Ignatiadis, Ioannis

2017-01-01

We present an innovative electrochemical probe for the monitoring of pH, redox potential and conductivity in near-field rocks of deep geological radioactive waste repositories. The probe is composed of a monocrystalline antimony electrode for pH sensing, four AgCl/Ag-based reference or Cl− selective electrodes, one Ag2S/Ag-based reference or S2− selective electrode, as well as four platinum electrodes, a gold electrode and a glassy-carbon electrode for redox potential measurements. Galvanostatic electrochemistry impedance spectroscopy using AgCl/Ag-based and platinum electrodes measure conductivity. The use of such a multi-parameter probe provides redundant information, based as it is on the simultaneous behaviour under identical conditions of different electrodes of the same material, as well as on that of electrodes made of different materials. This identifies the changes in physical and chemical parameters in a solution, as well as the redox reactions controlling the measured potential, both in the solution and/or at the electrode/solution interface. Understanding the electrochemical behaviour of selected materials thus is a key point of our research, as provides the basis for constructing the abacuses needed for developing robust and reliable field sensors. PMID:28608820

"Biocompatible" Neutral pH Low-GDP Peritoneal Dialysis Solutions: Much Ado About Nothing?

PubMed

Misra, Paraish S; Nessim, Sharon J; Perl, Jeffrey

2017-03-01

Adverse outcomes in peritoneal dialysis (PD), including PD related infections, the loss of residual kidney function (RKF), and longitudinal, deleterious changes in peritoneal membrane function continue to limit the long-term success of PD therapy. The observation that these deleterious changes occur upon exposure to conventional glucose-based PD solutions fuels the search for a more biocompatible PD solution. The development of a novel PD solution with a neutral pH, and lower in glucose degradation products (GDPs) compared to its conventional predecessors has been labeled a "biocompatible" solution. While considerable evidence in support of these novel solutions' biocompatibility has emerged from cell culture and animal studies, the clinical benefits as compared to conventional PD solutions are less clear. Neutral pH low GDP (NpHLGDP) PD solutions appear to be effective in reducing infusion pain, but their effects on other clinical endpoints including peritoneal membrane function, preservation of RKF, PD-related infections, and technique and patient survival are less clear. The literature is limited by studies characterized by relatively few patients, short follow-up time, heterogeneity with regards to the novel PD solution type under study, and the different patient populations under study. Nonetheless, the search for a more biocompatible PD solution continues with emerging data on promising non glucose-based solutions. © 2017 Wiley Periodicals, Inc.

pH-Responsive Micelle Sequestrant Polymers Inhibit Fat Absorption.

PubMed

Qian, Jian; Sullivan, Bradley P; Berkland, Cory

2015-08-10

Current antiobesity therapeutics are associated with side effects and/or poor long-term patient compliance, necessitating development of more efficacious and safer alternatives. Herein, we designed and engineered a new class of orally acting pharmaceutical agents, or micelle sequestrant polymers (MSPs), that could respond to the pH change in the gastrointestinal (GI) tract and potentially sequester lipid micelles; inhibiting lipid absorption through a pH-triggered flocculation process. These MSPs, derived from poly(2-(diisopropylamino)ethyl methacrylate) and poly(2-(dibutylamino)ethyl methacrylate), were soluble in acidic media, but they transitioned to become insoluble around pH 7.2 and 6.1, respectively. MSPs showed substantial bile acid and triglyceride sequestration capacity with fast pH response tested in vitro. In vivo study showed that orally dosed MSPs significantly enhanced fecal elimination of triglycerides and bile acids. Several MSPs increased fecal elimination of triglycerides by 9-10 times compared with that of the control. In contrast, fecal concentration of bile acids, but not triglycerides, was increased by cholestyramine or Welchol. Importantly, fecal elimination of bile acids and triglycerides was unaltered by addition of control dietary fibers. MSPs may serve as a novel approach to weight loss that inhibits excess caloric intake by preventing absorption of excess dietary triglycerides.

Lignor process for acidic rock drainage treatment.

PubMed

Zhuang, J M; Walsh, T

2004-09-01

The process using lignosulfonates for acidic rock drainage (ARD) treatment is referred to as the Lignor process. Lignosulfonates are waste by-products produced in the sulfite pulping process. The present study has shown lignosulfonates are able to protect lime from developing an external surface coating, and hence to favor its dissociation. Further, the addition of lignosulfonates to ARD solutions increased the dotting and settling rate of the formed sludge. The capability of lignosulfonates to form stable metal-lignin complexes makes them very useful in retaining metal ions and thus improving the long-term stability of the sludge against leaching. The Lignor process involves metal sorption with lignosulfonates, ARD neutralization by lime to about pH 7, pH adjustment with caustic soda to 9.4 - 9.6, air oxidation to lower the pH to a desired level, and addition of a minimum amount of FeCl3 for further removal of dissolved metals. The Lignor process removes all concerned metals (especially Al and Mn) from the ARD of the Britannia Mine (located at Britannia Beach, British Columbia, Canada) to a level lower than the limits of the B.C. Regulations. Compared with the high-density sludge (HDS) process, the Lignor process has many advantages, such as considerable savings in lime consumption, greatly reduced sludge volume, and improved sludge stability.

A Multi-Parametric Device with Innovative Solid Electrodes for Long-Term Monitoring of pH, Redox-Potential and Conductivity in a Nuclear Waste Repository.

PubMed

Daoudi, Jordan; Betelu, Stephanie; Tzedakis, Theodore; Bertrand, Johan; Ignatiadis, Ioannis

2017-06-13

We present an innovative electrochemical probe for the monitoring of pH, redox potential and conductivity in near-field rocks of deep geological radioactive waste repositories. The probe is composed of a monocrystalline antimony electrode for pH sensing, four AgCl/Ag-based reference or Cl - selective electrodes, one Ag₂S/Ag-based reference or S 2- selective electrode, as well as four platinum electrodes, a gold electrode and a glassy-carbon electrode for redox potential measurements. Galvanostatic electrochemistry impedance spectroscopy using AgCl/Ag-based and platinum electrodes measure conductivity. The use of such a multi-parameter probe provides redundant information, based as it is on the simultaneous behaviour under identical conditions of different electrodes of the same material, as well as on that of electrodes made of different materials. This identifies the changes in physical and chemical parameters in a solution, as well as the redox reactions controlling the measured potential, both in the solution and/or at the electrode/solution interface. Understanding the electrochemical behaviour of selected materials thus is a key point of our research, as provides the basis for constructing the abacuses needed for developing robust and reliable field sensors.

1999 Horton Research Grants awarded

NASA Astrophysics Data System (ADS)

The Horton (Hydrology) Research Grant Committee presented three grants at the 1999 AGU Spring Meeting in Boston, Massachusetts, last June. S. Jean Birks is currently a Ph.D. candidate in the Earth Sciences Department at the University of Waterloo under the supervision of Tom Edwards and Victoria Remenda (Queen's University). The title of her Ph.D. dissertation is “Long-term Natural Tracer Migration in Thick Unfractured Clay: Implications for Reconstructing the Post-glacial Isotopic History of Precipitation from Aquitards in the Northern Great Plains.” Jean received her B.Sc. in geography and environmental science from McMaster University and her M.Sc. in hydrogeology from Queen's University.

Screening for Cellulase Encoding Clones in Metagenomic Libraries.

PubMed

Ilmberger, Nele; Streit, Wolfgang R

2017-01-01

For modern biotechnology there is a steady need to identify novel enzymes. In biotechnological applications, however, enzymes often must function under extreme and nonnatural conditions (i.e., in the presence of solvents, high temperature and/or at extreme pH values). Cellulases have many industrial applications from the generation of bioethanol, a realistic long-term energy source, to the finishing of textiles. These industrial processes require cellulolytic activity under a wide range of pH, temperature, and ionic conditions, and they are usually carried out by mixtures of cellulases. Investigation of the broad diversity of cellulolytic enzymes involved in the natural degradation of cellulose is necessary for optimizing these processes.

Characterization of Growing Soil Bacterial Communities across a pH gradient Using H218O DNA-Stable Isotope Probing

NASA Astrophysics Data System (ADS)

Welty-Bernard, A. T.; Schwartz, E.

2014-12-01

Recent studies have established consistent relationships between pH and bacterial diversity and community structure in soils from site-specific to landscape scales. However, these studies rely on DNA or PLFA extraction techniques from bulk soils that encompass metabolically active and inactive, or dormant, communities, and loose DNA. Dormant cells may comprise up to 80% of total live cells. If dormant cells dominate a particular environment, it is possible that previous interpretations of the soil variables assumed to drive communities could be profoundly affected. We used H218O stable isotope probing and bar-coded illumina sequencing of 16S rRNA genes to monitor the response of actively growing communities to changes in soil pH in a soil microcosm over 14 days. This substrate-independent approach has several advantages over 13C or 15N-labelled molecules in that all growing bacteria should be able to make use of water, allowing characterization of whole communities. We hypothesized that Acidobacteria would increasingly dominate the growing community and that Actinobacteria and Bacteroidetes would decline, given previously established responses by these taxa to soil pH. Instead, we observed the reverse. Actinobacteria abundance increased three-fold from 26 to 76% of the overall community as soil pH fell from pH 5.6 to pH 4.6. Shifts in community structure and decreases in diversity with declining soil pH were essentially driven by two families, Streptomyceaca and Microbacteracea, which collectively increased from 2 to 40% of the entire community. In contrast, Acidobacteria as a whole declined although numbers of subdivision 1 remained stable across all soil pH levels. We suggest that the brief incubation period in this SIP study selected for growth of acid-tolerant Actinobacteria over Acidobacteria. Taxa within Actinomycetales have been readily cultured over short time frames, suggesting rapid growth patterns. Conversely, taxa within Acidobacteria have been characterized as slow growers with low cell turnover and may represent a relatively quiescent portion of the bacterial community over the short-term. These results suggest that the short-term responses by individual taxa to pH may differ significantly from long-term responses reflecting variable life strategies within the community itself.

Understanding long-term silver release from surface modified porous titanium implants.

PubMed

Shivaram, Anish; Bose, Susmita; Bandyopadhyay, Amit

2017-08-01

Prevention of orthopedic device related infection (ODRI) using antibiotics has met with limited amount of success and is still a big concern during post-surgery. As an alternative, use of silver as an antibiotic treatment to prevent surgical infections is being used due to the well-established antimicrobial properties of silver. However, in most cases silver is used in particulate form with wound dressings or with short-term devices such as catheters but not with load-bearing implants. We hypothesize that strongly adherent silver to load-bearing implants can offer longer term solution to infection in vivo. Keeping that in mind, the focus of this study was to understand the long term release study of silver ions for a period of minimum 6months from silver coated surface modified porous titanium implants. Implants were fabricated using a LENS™ system, a powder based additive manufacturing technique, with at least 25% volume porosity, with and without TiO 2 nanotubes in phosphate buffer saline (pH 7.4) to see if the total release of silver ions is within the toxic limit for human cells. Considering the fact that infection sites may reduce the local pH, silver release was also studied in acetate buffer (pH 5.0) for a period of 4weeks. Along with that, the osseointegrative properties as well as cytotoxicity of porous titanium implants were assessed in vivo for a period of 12weeks using a rat distal femur model. In vivo results indicate that porous titanium implants with silver coating show comparable, if not better, biocompatibility and bonding at the bone-implant interface negating any concerns related to toxicity related to silver to normal cells. The current research is based on our recently patented technology, however focused on understanding longer-term silver release to mitigate infection related problems in load-bearing implants that can even arise several months after the surgery. Prevention of orthopedic device related infection using antibiotics has met with limited success and is still a big concern during post-surgery. Use of silver as an antibiotic treatment to prevent surgical infections is being explored due to the well-established antimicrobial properties of silver. However, in most cases silver is used in particulate form with wound dressings or with short-term devices such as catheters but not with load-bearing implants. We hypothesize that strongly adherent silver to load-bearing implants can offer longer-term solution towards infection in vivo. Keeping that in mind, the focus of this study was to understand the long-term release of silver ions, for a period of minimum 6months, from silver coated surface modified porous titanium implants. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Outgassing of the Eastern Equatorial Pacific during the Pliocene period.

NASA Astrophysics Data System (ADS)

Guillermic, M.; Tripati, A.

2016-12-01

The transition from the warm, ice-free conditions of the early Cenozoic to present-day glacial state with ice sheets in both hemispheres has been ascribed to long- and short-term changes in atmospheric CO2. The processes causing long-term changes in atmospheric CO2 levels are of debate. One possible explanation for changes in atmospheric CO2 relates to changes in air-sea exchange due to fluctuations in ocean carbon sources and sinks, as modulated by the stratification of surface waters. While nutrient consumption in low-latitude environments and associated export of CO2 to the deep sea works to sequester CO2 in the ocean interior, the return of deep water to the surface in the high latitudes and upwelling at the equator and in the eastern portion of ocean basins releases CO2. Quantitative estimates for surface water pH and pCO2 in different regions of the ocean and identification of CO2-sources and sinks are needed to better understand the role of the ocean in driving and/or amplifying variations in the atmospheric CO2 reservoir and climate change. Here we present preliminary results of surface water pH for the early Pliocene to Holocene based on boron isotope measurements of planktic foraminifera for the Eastern Equatorial Pacific. We develop records of B/Ca, Mg/Ca ratios, boron isotopes, and oxygen isotopes measurements in foraminifera tests (Globigeneroides sacculifer, Globigeneroides ruber, Neogloboquadrina dutertrei). We reconstruct changes in ocean CO2 outgassing in the Eastern Equatorial Pacific using records from ODP Site 847 (0°N, 95°W, 3373 m water depth). These data are used to examine if there is evidence for changes in stratification and CO2 outgassing during the early Pliocene warm period and during Pliocene intensification of Northern Hemisphere glaciation.

Estimation of palaeohydrochemical conditions using carbonate minerals

NASA Astrophysics Data System (ADS)

Amamiya, H.; Mizuno, T.; Iwatsuki, T.; Yuguchi, T.; Murakami, H.; Saito-Kokubu, Y.

2014-12-01

The long-term evolution of geochemical environment in deep underground is indispensable research subject for geological disposal of high-level radioactive waste, because the evolution of geochemical environment would impact migration behavior of radionuclides in deep underground. Many researchers have made efforts previously to elucidate the geochemical environment within the groundwater residence time based on the analysis of the actual groundwater. However, it is impossible to estimate the geochemical environment for the longer time scale than the groundwater residence time in this method. In this case, analysis of the chemical properties of secondary minerals are one of useful method to estimate the paleohydrochemical conditions (temperature, salinity, pH and redox potential). In particular, carbonate minerals would be available to infer the long-term evolution of hydrochemical for the following reasons; -it easily reaches chemical equilibrium with groundwater and precipitates in open space of water flowing path -it reflects the chemical and isotopic composition of groundwater at the time of crystallization We reviewed the previous studies on carbonate minerals and geochemical conditions in deep underground and estimated the hydrochemical characteristics of past groundwater by using carbonate minerals. As a result, it was found that temperature and salinity of the groundwater during crystallization of carbonate minerals were evaluated quantitatively. On the other hand, pH and redox potential can only be understood qualitatively. However, it is suggested that the content of heavy metal elements such as manganese, iron and uranium, and rare earth elements in the carbonate minerals are useful indicators for estimating redox potential. This study was carried out under a contract with METI (Ministry of Economy, Trade and Industry) as part of its R&D supporting program for developing geological disposal technology.

Biofouling protection for marine underwater observatories sensors by local chlorination

NASA Astrophysics Data System (ADS)

Delauney, L.; Compere, C.; Coail, J. Y.; Guyader, G.

2009-04-01

During the last 20 years, many marine autonomous environment monitoring networks are set up in the world. They commonly use various sensors like dissolved oxygen, turbidity, conductivity, pH or fluorescence. These stations have been developed aiming at either collecting field data to calibrate satellite observations or for water quality assessment. Most of them are surface buoys or subsurface moorings. These systems are now equipped with sophisticated sensing equipment. Sensors, housings and support structures are subject to fouling problems and emphasis has to be put on the long-term quality of measurements that may face very short-term biofouling effects. Biofouling has long been considered as a limiting factor in ocean monitoring requiring the placement of any materials under water. Many potential solutions to this problem have been proposed. The biofouling can disrupt the quality measurement sometimes in less than a week. Many techniques to prevent biofouling on instrumentation are actually listed and studied by researchers and manufacturers. Some of them are implemented on instruments. Very few of them has been tested in-situ for long term deployment. This situation is very complex and must be approached simultaneously in two ways: by the improvement of knowledge of biofouling kinetics and by the development of prevention strategies. This biofouling development gives rise very often to a continuous shift of the measurements. Consequently the measurements can be out of tolerance and then data are unworkable. Video systems such as cameras, video equipments and lights are as well disrupted by biofouling. Pictures become blurred or noisy and lights loose efficiency since the light intensity is decreasing due to the screen effect of biofilm and macro-fouling. The protection of the sensing area of the sensor is a concern which has been treated for the last decade, operational solutions are now implemented on commercially equipment and are used for long term deployment, however common solutions like wipers or copper screen present technological weakness due to mechanical complexity, on the other hand the use chemical biocide like TBT (Tributyl tin) is now impossible. Despite the fact that this chemical have proved to be extremely efficient, tributyl-tin compounds have been shown to have deleterious effects upon the environment. TBT is now banned for antifouling paints from 2003 and should not be used on ships hull from 2008. A convenient method consists of localised chlorine generation. This paper presents the results of research and development on biofouling protection for marine environmental sensors by local chlorination. We will demonstrate the efficiency of the localised chlorine generation method for long term coastal deployment specifically for continental margin benthic observatories. This reliable technique can be adapted to many kind of sensors quite easily and to optical ports usually used for oceanographic instruments, cameras, video and lights.

Long-term athletic development- part 1: a pathway for all youth.

PubMed

Lloyd, Rhodri S; Oliver, Jon L; Faigenbaum, Avery D; Howard, Rick; De Ste Croix, Mark B A; Williams, Craig A; Best, Thomas M; Alvar, Brent A; Micheli, Lyle J; Thomas, D Phillip; Hatfield, Disa L; Cronin, John B; Myer, Gregory D

2015-05-01

The concept of developing talent and athleticism in youth is the goal of many coaches and sports systems. Consequently, an increasing number of sporting organizations have adopted long-term athletic development models in an attempt to provide a structured approach to the training of youth. It is clear that maximizing sporting talent is an important goal of long-term athletic development models. However, ensuring that youth of all ages and abilities are provided with a strategic plan for the development of their health and physical fitness is also important to maximize physical activity participation rates, reduce the risk of sport- and activity-related injury, and to ensure long-term health and well-being. Critical reviews of independent models of long-term athletic development are already present within the literature; however, to the best of our knowledge, a comprehensive examination and review of the most prominent models does not exist. Additionally, considerations of modern day issues that may impact on the success of any long-term athletic development model are lacking, as are proposed solutions to address such issues. Therefore, within this 2-part commentary, Part 1 provides a critical review of existing models of practice for long-term athletic development and introduces a composite youth development model that includes the integration of talent, psychosocial and physical development across maturation. Part 2 identifies limiting factors that may restrict the success of such models and offers potential solutions.

Physiological mechanism of the overproduction of ε-poly-L-lysine by acidic pH shock in fed-batch fermentation.

PubMed

Ren, Xi-Dong; Chen, Xu-Sheng; Tang, Lei; Zeng, Xin; Wang, Liang; Mao, Zhong-Gui

2015-11-01

The introduction of an environmental stress of acidic pH shock had successfully solved the common deficiency existed in ε-PL production, viz. the distinct decline of ε-PL productivity in the feeding phase of the fed-batch fermentation. To unravel the underlying mechanism, we comparatively studied the physiological changes of Streptomyces sp. M-Z18 during fed-batch fermentations with the pH shock strategy (PS) and pH non-shock strategy (PNS). Morphology investigation showed that pellet-shape change was negligible throughout both fermentations. In addition, the distribution of pellet size rarely changed in the PS, whereas pellet size and number decreased substantially with time in the PNS. This was consistent with the performances of ε-PL productivity in both strategies, demonstrating that morphology could be used as a predictor of ε-PL productivity during fed-batch fermentation. Furthermore, a second growth phase happened in the PS after pH shock, followed by the re-appearance of live mycelia in the dead core of the pellets. Meanwhile, mycelia respiration and key enzymes in the central metabolic and ε-PL biosynthetic pathways were overall strengthened until the end of the fed-batch fermentation. As a result, the physiological changes induced by the acidic pH shock have synergistically and permanently contributed to the stimulation of ε-PL productivity. However, this second growth phase and re-appearance of live mycelia were absent in the PNS. These results indicated that the introduction of a short-term suppression on mycelia physiological metabolism would guarantee the long-term high ε-PL productivity.

Totomatix: a novel automatic set-up to control diurnal, diel and long-term plant nitrate nutrition

PubMed Central

Adamowicz, Stéphane; Le Bot, Jacques; Huanosto Magaña, Ruth; Fabre, José

2012-01-01

Background Stand-alone nutritional set-ups are useful tools to grow plants at defined nutrient availabilities and to measure nutrient uptake rates continuously, in particular that for nitrate. Their use is essential when the measurements are meant to cover long time periods. These complex systems have, however, important drawbacks, including poor long-term reliability and low precision at high nitrate concentration. This explains why the information dealing with diel dynamics of nitrate uptake rate is scarce and concerns mainly young plants grown at low nitrate concentration. Scope The novel system detailed in this paper has been developed to allow versatile use in growth rooms, greenhouses or open fields at nitrate concentrations ranging from a few micro- to several millimoles per litres. The system controls, at set frequencies, the solution nitrate concentration, pH and volumes. Nitrate concentration is measured by spectral deconvolution of UV spectra. The main advantages of the set-up are its low maintenance (weekly basis), an ability to diagnose interference or erroneous analyses and high precision of nitrate concentration measurements (0·025 % at 3 mm). The paper details the precision of diurnal nitrate uptake rate measurements, which reveals sensitivity to solution volume at low nitrate concentration, whereas at high concentration, it is mostly sensitive to the precision of volume estimates. Conclusions This novel set-up allows us to measure and characterize the dynamics of plant nitrate nutrition at high temporal resolution (minutes to hours) over long-term experiments (up to 1 year). It is reliable and also offers a novel method to regulate up to seven N treatments by adjusting the daily uptake of test plants relative to controls, in variable environments such as open fields and glasshouses. PMID:21985796

Development of a Self-Assessment Tool to Facilitate Decision-Making in Choosing a Long Term Care Administration Major

ERIC Educational Resources Information Center

Johs-Artisensi, Jennifer L.; Olson, Douglas M.; Nahm, Abraham Y.

2016-01-01

Long term care administrators need a broad base of knowledge, skills, and interests to provide leadership and be successful in managing a fiscally responsible, quality long term care organization. Researchers developed a tool to help students assess whether a long term care administration major is a compatible fit. With input from professionals in…

Patterns in Temporal Variability of Temperature, Oxygen and pH along an Environmental Gradient in a Coral Reef

PubMed Central

Guadayol, Òscar; Silbiger, Nyssa J.; Donahue, Megan J.; Thomas, Florence I. M.

2014-01-01

Spatial and temporal environmental variability are important drivers of ecological processes at all scales. As new tools allow the in situ exploration of individual responses to fluctuations, ecologically meaningful ways of characterizing environmental variability at organism scales are needed. We investigated the fine-scale spatial heterogeneity of high-frequency temporal variability in temperature, dissolved oxygen concentration, and pH experienced by benthic organisms in a shallow coastal coral reef. We used a spatio-temporal sampling design, consisting of 21 short-term time-series located along a reef flat-to-reef slope transect, coupled to a long-term station monitoring water column changes. Spectral analyses revealed sharp gradients in variance decomposed by frequency, as well as differences between physically-driven and biologically-reactive parameters. These results highlight the importance of environmental variance at organismal scales and present a new sampling scheme for exploring this variability in situ. PMID:24416364

Long-Term Care for People with Development Disabilities: A Critical Analysis.

ERIC Educational Resources Information Center

Palley, Howard A.; Van Hollen, Valerie

2000-01-01

Explores how the trends toward long-term community care affecting people with developmental disabilities developed. Appropriateness of care and quality of life issues are discussed. Reviews the development of long-term care for frail and disabled elderly people and explores the arguments for a continuum of care that have developed in this area.…

Survival and Growth of Probiotic Lactic Acid Bacteria in Refrigerated Pickle Products.

PubMed

Fan, Sicun; Breidt, Fred; Price, Robert; Pérez-Díaz, Ilenys

2017-01-01

We examined 10 lactic acid bacteria that have been previously characterized for commercial use as probiotic cultures, mostly for dairy products, including 1 Pediococcus and 9 Lactobacilli. Our objectives were to develop a rapid procedure for determining the long-term survivability of these cultures in acidified vegetable products and to identify suitable cultures for probiotic brined vegetable products. We therefore developed assays to measure acid resistance of these cultures to lactic and acetic acids, which are present in pickled vegetable products. We used relatively high acid concentrations (compared to commercial products) of 360 mM lactic acid and 420 mM acetic acid to determine acid resistance with a 1 h treatment. Growth rates were measured in a cucumber juice medium at pH 5.3, 4.2, and 3.8, at 30 °C and 0% to 2% NaCl. Significant differences in acid resistance and growth rates were found among the 10 cultures. In general, the acid resistant strains had slower growth rates than the acid sensitive strains. Based on the acid resistance data, selected cultures were tested for long-term survival in a simulated acidified refrigerated cucumber product. We found that one of the most acid resistant strains (Lactobacillus casei) could survive for up to 63 d at 4 °C without significant loss of viability at 10 8 CFU/mL. These data may aid in the development of commercial probiotic refrigerated pickle products. © 2016 Institute of Food Technologists®.

Response of marine bacterioplankton pH homeostasis gene expression to elevated CO2

NASA Astrophysics Data System (ADS)

Bunse, Carina; Lundin, Daniel; Karlsson, Christofer M. G.; Akram, Neelam; Vila-Costa, Maria; Palovaara, Joakim; Svensson, Lovisa; Holmfeldt, Karin; González, José M.; Calvo, Eva; Pelejero, Carles; Marrasé, Cèlia; Dopson, Mark; Gasol, Josep M.; Pinhassi, Jarone

2016-05-01

Human-induced ocean acidification impacts marine life. Marine bacteria are major drivers of biogeochemical nutrient cycles and energy fluxes; hence, understanding their performance under projected climate change scenarios is crucial for assessing ecosystem functioning. Whereas genetic and physiological responses of phytoplankton to ocean acidification are being disentangled, corresponding functional responses of bacterioplankton to pH reduction from elevated CO2 are essentially unknown. Here we show, from metatranscriptome analyses of a phytoplankton bloom mesocosm experiment, that marine bacteria responded to lowered pH by enhancing the expression of genes encoding proton pumps, such as respiration complexes, proteorhodopsin and membrane transporters. Moreover, taxonomic transcript analysis showed that distinct bacterial groups expressed different pH homeostasis genes in response to elevated CO2. These responses were substantial for numerous pH homeostasis genes under low-chlorophyll conditions (chlorophyll a <2.5 μg l-1) however, the changes in gene expression under high-chlorophyll conditions (chlorophyll a >20 μg l-1) were low. Given that proton expulsion through pH homeostasis mechanisms is energetically costly, these findings suggest that bacterioplankton adaptation to ocean acidification could have long-term effects on the economy of ocean ecosystems.

Ionic pH and glucose sensors fabricated using hydrothermal ZnO nanostructures

NASA Astrophysics Data System (ADS)

Wang, Jyh-Liang; Yang, Po-Yu; Hsieh, Tsang-Yen; Juan, Pi-Chun

2016-01-01

Hydrothermally synthesized aluminum-doped ZnO (AZO) nanostructures have been adopted in extended-gate field-effect transistor (EGFET) sensors to demonstrate the sensitive and stable pH and glucose sensing characteristics of AZO-nanostructured EGFET sensors. The AZO-nanostructured EGFET sensors exhibited the following superior pH sensing characteristics: a high current sensitivity of 0.96 µA1/2/pH, a high linearity of 0.9999, less distortion of output waveforms, a small hysteresis width of 4.83 mV, good long-term repeatability, and a wide sensing range from pHs 1 to 13. The glucose sensing characteristics of AZO-nanostructured biosensors exhibited the desired sensitivity of 60.5 µA·cm-2·mM-1 and a linearity of 0.9996 up to 13.9 mM. The attractive characteristics of high sensitivity, high linearity, and repeatability of using ionic AZO-nanostructured EGFET sensors indicate their potential use as electrochemical and disposable biosensors.

Characterization of an immobilized cell, trickle bed reactor during long term butanol (ABE) fermentation.

PubMed

Park, C H; Okos, M R; Wankat, P C

1990-06-20

Acetone-butanol-ethanol (ABE) fermentation was performed continuously in an immobilized cell, trickle bed reactor for 54 days without, degeneration by maintaining the pH above 4.3. Column clogging was minimized by structured packing of immobilization matrix. The reactor contained two serial glass columns packed with Clostridium acetobutylicum adsorbed on 12- and 20-in.-long polyester sponge strips at total flow rates between 38 and 98.7 mL/h. Cells were initially grown at 20 g/L glucose resulting in low butanol (1.15 g/L) production encouraging cell growth. After the initial cell growth phase a higher glucose concentration (38.7 g/L) improved solvent yield from 13.2 to 24.1 wt%, and butanol production rate was the best. Further improvement in solvent yield and butanol production rate was not observed with 60 g/L of glucose. However, when the fresh nutrient supply was limited to only the first column, solvent yield increased to 27.3 wt% and butanol selectivity was improved to 0.592 as compared to 0.541 when fresh feed was fed to both columns. The highest butanol concentration of 5.2 g/L occurred at 55% conversion of the feed with 60 g/L glucose. Liquid product yield of immobilized cells approached the theoretical value reported in the literature. Glucose and product concentration profiles along the column showed that the columns can be divided into production and inhibition regions. The length of each zone was dependent upon the feed glucose concentration and feed pattern. Unlike batch fermentation, there was no clear distinction between acid and solvent production regions. The pH dropped, from 6.18-6.43 to 4.50-4.90 in the first inch of the reactor. The pH dropped further to 4.36-4.65 by the exit of the column. The results indicate that the strategy for long term stable operation with high solvent yield requires a structured packing of biologically stable porous matrix such as polyester sponge, a pH maintenance above 4.3, glucose concentrations up to 60 g/L and nutrient supply only to the inlet of the reactor.

Chemical hazards from acid crater lakes

NASA Astrophysics Data System (ADS)

van Bergen, M. J.; Sumarti, S.; Heikens, A.; Bogaard, T. A.; Hartiyatun, S.

2003-04-01

Acid crater lakes, which are hosted by a considerable number of active volcanoes, form a potential threat for local ecosystems and human health, as they commonly contain large amounts of dissolved chemicals. Subsurface seepage or overflow can lead to severe deterioration of the water quality of rivers and wells, as observations around several of these volcanoes have shown. The Ijen crater lake in East Java (Indonesia) is a striking example, as this reservoir of hyperacid (pH<0.5) sulphate, chloride and fluoride-rich water is the source of a ca. 50 km long acid river that transports substantial quantities of potentially toxic elements. A downstream trend of increasing pH from <1 to 2.5-4 is largely due to dilution with moderately acid springs (pH= ca. 4) and neutral tributaries (pH= ca. 7) inside the Ijen caldera. Geochemical controls that regulate element transport are subject to seasonal fluctuations in rainfall. Long-term monitoring has shown that fluoride levels pose some of the most severe environmental threats. Its concentration decreases from ca. 1300 mg/kg in the lake to ca. 10 mg/kg in a coastal area downstream, where virtually all of the river water is used for irrigating rice fields and other cropland. Apart from serious problems for agriculture, our survey of 55 drinking water wells in the irrigation area shows that 50% contain fluoride above the 1.5 ppm WHO limit, in line with the observation that dental fluorosis is widespread among the ca. 100,000 residents of the area. A conspicuous spatial correlation between fluoride concentrations and the irrigation system suggest that long-term (century) infiltration of irrigation water may have affected the quality of groundwater. Fluorosis is also a problem in some villages within the caldera, where well water sources may have a more direct subsurface connection with the lake system. From our observations we conclude that water-quality monitoring is especially needed for health reasons in volcanic areas where volatile elements, derived from passively degassing magma, are intercepted by (sub) surface water bodies.

Bioelectrochemical desalination and electricity generation in microbial desalination cell with dewatered sludge as fuel.

PubMed

Meng, Fanyu; Jiang, Junqiu; Zhao, Qingliang; Wang, Kun; Zhang, Guodong; Fan, Qingxin; Wei, Liangliang; Ding, Jing; Zheng, Zhen

2014-04-01

Microbial desalination cells (MDCs) with common liquid anodic substrate exhibit a slow startup and destructive pH drop, and abiotic cathodes have high cost and low sustainability. A biocathode MDC with dewatered sludge as fuel was developed for synergistic desalination, electricity generation and sludge stabilization. Experimental results indicated that the startup period was reduced to 3d, anodic pH was maintained between 6.6 and 7.6, and high stability was shown under long-term operation (300d). When initial NaCl concentrations were 5 and 10g/L, the desalinization rates during stable operation were 46.37±1.14% and 40.74±0.89%, respectively. The maximum power output of 3.178W/m(3) with open circuit voltage (OCV) of 1.118V was produced on 130d. After 300d, 25.71±0.15% of organic matter was removed. These results demonstrated that dewatered sludge was an appropriate anodic substrate to enhance MDC stability for desalination and electricity generation. Copyright © 2014 Elsevier Ltd. All rights reserved.

A propofol microemulsion with low free propofol in the aqueous phase: formulation, physicochemical characterization, stability and pharmacokinetics.

PubMed

Cai, WeiHui; Deng, WanDing; Yang, HuiHui; Chen, XiaoPing; Jin, Fang

2012-10-15

The purpose of this study was to develop a propofol microemulsion with a low concentration of free propofol in the aqueous phase. Propofol microemulsions were prepared based on single-factor experiments and orthogonal design. The optimal microemulsion was evaluated for pH, osmolarity, particle size, zeta potential, morphology, free propofol in the aqueous phase, stability, and pharmacokinetics in beagle dogs, and comparisons made with the commercial emulsion, Diprivan(®). The pH and osmolarity of the microemulsion were similar to those of Diprivan(®). The average particle size was 22.6±0.2 nm, and TEM imaging indicated that the microemulsion particles were spherical in appearance. The concentration of free propofol in the microemulsion was 21.3% lower than that of Diprivan(®). Storage stability tests suggested that the microemulsion was stable long-term under room temperature conditions. The pharmacokinetic profile for the microemulsion showed rapid distribution and elimination compared to Diprivan(®). We conclude that the prepared microemulsion may be clinically useful as a potential carrier for propofol delivery. Copyright © 2012 Elsevier B.V. All rights reserved.

PHYSICAL AND CHEMICAL STABILITY ANALYSIS OF COSMETIC MULTI- PLE EMULSIONS LOADED WITH ASCORBYL PALMITATE AND SODIUM ASCORBYL PHOSPHATE SALTS.

PubMed

Khan, Hira; Akhtar, Naveed; Ali, Atif; Khan, Haji M Shoaib; Sohail, Muhammad; Naeem, Muhammad; Nawaz, Zarqa

2016-09-01

Stability of hydrophilic and lipophilic vitamin C derivatives for quenching synergistic antioxidant activities and to treat oxidative related diseases is a major issue. This study was aimed to encapsulate hydrophilic and lipophilic vitamin C derivatives (ascorbyl palmitate and sodium ascorbyl phosphate) as functional ingredients in a newly formulated multiple emulsion of the W//W type to attain the synergistic antioxidant effects and the resultant system's long term physical and chemical stability. Several multiple emulsions using the same concentration of emulsifiers but different concentrations of ascorbyl palmitate and sodium ascorbyl phosphate were developed. Three finally selected multiple emulsions (ME₁, ME₂ and ME₃) were evaluated for physical stability in terms of rheology, microscopy, conductivity, pH, and organoleptic characteristics under different storage conditions for 3 months. Chemical stability was determined by HPLC on Sykam GmbH HPLC system (Germany), equipped with a variable UV detector. Results showed that at accelerated storage conditions all the three multiple emulsions had shear thinning behavior of varying shear stress with no influence of location of functional ingredients in a carrier system. Conductivity values increased and pH values remained within the skin pH range for 3 months. Microscopic analysis showed an increase in globule size with the passage of time, especially at higher temperatures while decreased at low temperatures. Centrifugation test did not cause phase separation till the 45th day, but little effects after 2 months. Chemical stability analysis by HPLC at the end of 3 months showed that ascorbyl palmitate and sodium ascorbyl phosphate were almost stable in all multiple emulsions with no influence of their location in a carrier system. Multiple emulsions were found a stable carrier for hydrophilic and lipophilic vitamin C derivatives to enhance their desired effects. Considering that many topical formulations contain simple vitamin C it is suggested that present study may contribute to the development of more stable formulations with a combination of vitamin C derivatives to enhance their cosmetic benefits.

Episodic acidification of 5 rivers in Canada's oil sands during snowmelt: A 25-year record.

PubMed

Alexander, A C; Chambers, P A; Jeffries, D S

2017-12-01

Episodic acidification during snowmelt is a natural phenomenon that can be intensified by acidic deposition from heavy industry. In Canada's oil sands region, acid deposition is estimated to be as much as 5% of the Canadian total and large tracks of northeastern Alberta are considered acid-sensitive because of extensive peatland habitats with poorly weathered soils. To identify the frequency, duration and severity of acidification episodes during snowmelt (the predominant hydrological period for delivery of priority pollutants from atmospheric oil sands emissions to surface waters), a 25-year record (1989 to 2014) of automated water quality data (pH, temperature, conductivity) was assembled for 3 rivers along with a shorter record (2012-2014) for another 2 rivers. Acidic episodes (pH<7, ANC<0) were recorded during 39% of all 83 snowmelt events. The severity (duration x magnitude) of episodic acidification increased exponentially over the study period (r 2 =0.56, P<0.01) and was strongly correlated (P<0.01) with increasing maximum air temperature and weakly correlated with regional land development (P=0.06). Concentrations of aluminum and 11 priority pollutants (Sb, As, Be, Cd, Cr, Cu, Pb, Se, Ag, Tl and Zn) were greatest (P<0.01) during low (<6.5) pH episodes, particularly when coincident with high discharge, such that aluminum and copper concentrations were at times high enough to pose a risk to juvenile rainbow trout (Oncorhynchus mykiss). Although low pH (pH<6.5) was observed during only 8% of 32 acidification episodes, when present, low pH typically lasted 10days. Episodic surface water acidification during snowmelt, and its potential effects on aquatic biota, is therefore an important consideration in the design of long-term monitoring of these typically alkaline (pH=7.72±0.05) rivers. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

76 FR 72423 - Bridging the Idea Development Evaluation Assessment and Long-Term Initiative and Total Product...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-23

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2011-N-0780] Bridging the Idea Development Evaluation Assessment and Long-Term Initiative and Total Product Life Cycle... Idea Development Evaluation Assessment and Long-Term Initiative and Total Product Life Cycle Approaches...

Disruption of THY-1 signaling in alveolar lipofibroblasts in experimentally induced congenital diaphragmatic hernia.

PubMed

Friedmacher, Florian; Hofmann, Alejandro Daniel; Takahashi, Hiromizu; Takahashi, Toshiaki; Gosemann, Jan-Hendrik; Puri, Prem

2014-02-01

Pulmonary hypoplasia (PH), characterized by alveolar immaturity, remains the main cause of neonatal mortality and long-term morbidity in infants with congenital diaphragmatic hernia (CDH). Lipid-containing interstitial fibroblasts (LIFs) are critically important for normal alveolar development. Thymocyte antigen 1 (Thy-1) is a highly expressed cell-surface protein in this specific subset of lung fibroblasts, which plays a key role in fetal alveolarization by coordinating the differentiation and lipid homeostasis of alveolar LIFs. Thy-1 increases the lipid content of LIFs by upregulation of adipocyte differentiation-related protein (ADRP), a lipogenic molecular marker characterizing pulmonary LIFs. Thy-1 (-/-) mice further show impaired alveolar development with reduced proliferation of pulmonary LIFs, resulting in a PH-similar phenotype. We hypothesized that pulmonary Thy-1 signaling is disrupted in experimentally induced CDH, which may has an adverse effect on the lipid content of alveolar LIFs. Timed-pregnant Sprague-Dawley rats were treated with either 100 mg nitrofen or vehicle on embryonic day 9.5 (E9.5). Fetuses were killed on E21.5, and lungs were divided into controls (n = 14) and CDH-associated PH (n = 14). Pulmonary gene expression levels of Thy-1 and ADRP were assessed by quantitative real-time PCR. ADRP immunohistochemistry and oil-red-O staining were used to localize alveolar LIF expression and lipid droplets. Immunofluorescence double staining for Thy-1 and oil-red-O was performed to evaluate Thy-1 expression and lipid content in alveolar LIFs. Radial alveolar count was significantly reduced in CDH-associated PH with significant downregulation of pulmonary Thy-1 and ADRP mRNA expression compared to controls. ADRP immunoreactivity and lipid droplets were markedly diminished in alveolar interstitial cells, which coincided with decreased alveolar LIF expression in CDH-associated PH compared to controls. Confocal laser scanning microscopy confirmed markedly decreased Thy-1 expression and lipid content in alveolar LIFs of CDH-associated PH compared to controls. Our study provides strong evidence that disruption of pulmonary Thy-1 signaling results in reduced lipid droplets in alveolar LIFs and may thus contribute to PH in the nitrofen-induced CDH model. Treatment modalities aimed at increasing lipid content in alveolar LIFs may therefore have a therapeutic potential in attenuating CDH-associated PH.

Impact of forest liming on growth, vigor, and reproduction of sugar maple and associated hardwoods

Treesearch

Robert P. Long; Stephen B. Horsley; Paul R. Lilja

1999-01-01

In 1985 a long-term study was initiated by the Pennsylvania Bureau of Forestry and the Northeastern Research Station to evaluate factors impeding regeneration of Allegheny hardwoods (Auchmoody, unpublished). The major factors suspected of limiting regeneration were high soil aluminum levels associated with low soil pH (typically 3.6 to 4.2 in surface mineral soils),...

Long-term evaluation of cardiac and vascular toxicity in patients with Philadelphia chromosome-positive leukemias treated with bosutinib.

PubMed

Cortes, Jorge E; Jean Khoury, H; Kantarjian, Hagop; Brümmendorf, Tim H; Mauro, Michael J; Matczak, Ewa; Pavlov, Dmitri; Aguiar, Jean M; Fly, Kolette D; Dimitrov, Svetoslav; Leip, Eric; Shapiro, Mark; Lipton, Jeff H; Durand, Jean-Bernard; Gambacorti-Passerini, Carlo

2016-06-01

Vascular and cardiac safety during tyrosine kinase inhibitor (TKI) therapy is an emerging issue. We evaluated vascular/cardiac toxicities associated with long-term bosutinib treatment for Philadelphia chromosome-positive (Ph+) leukemia based on treatment-emergent adverse events (TEAEs) and changes in QTc intervals and ejection fraction in two studies: a phase 1/2 study of second-/third-/fourth-line bosutinib for Ph+ leukemia resistant/intolerant to prior TKIs (N = 570) and a phase 3 study of first-line bosutinib (n = 248) versus imatinib (n = 251) in chronic phase chronic myeloid leukemia. Follow-up time was ≥48 months (both studies). Incidences of vascular/cardiac TEAEs in bosutinib-treated patients were 7%/10% overall with similar incidences observed with first-line bosutinib (5%/8%) and imatinib (4%/6%). Few patients had grade ≥3 vascular/cardiac events (4%/4%) and no individual TEAE occurred in >2% of bosutinib patients. Exposure-adjusted vascular/cardiac TEAE rates (patients with events/patient-year) were low for second-line or later bosutinib (0.037/0.050) and not significantly different between first-line bosutinib (0.015/0.024) and imatinib (0.011/0.017; P ≥ 0.267). Vascular/cardiac events were managed mainly with concomitant medications (39%/44%), bosutinib treatment interruptions (18%/21%), or dose reductions (4%/8%); discontinuations due to these events were rare (0.7%/1.0%). Based on logistic regression modelling, performance status >0 and history of vascular or cardiac disorders were prognostic of vascular/cardiac events in relapsed/refractory patients; hyperlipidemia/hypercholesterolemia and older age were prognostic of cardiac events. In newly diagnosed patients, older age was prognostic of vascular/cardiac events; history of diabetes was prognostic of vascular events. Incidences of vascular and cardiac events were low with bosutinib in the first-line and relapsed/refractory settings following long-term treatment in patients with Ph+ leukemia. Am. J. Hematol. 91:606-616, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Geologic setting and water quality of selected basins in the active coal-mining areas of Ohio, 1989-91, with a summary of water quality for 1985-91

USGS Publications Warehouse

Sedam, A.C.; Francy, D.S.

1993-01-01

This report presents streamwater- and ground-water-quality data collected to characterize the baseline water quality for 21 drainage basins in the coal-mining region of eastern Ohio. The study area is mostly within the unglaciated part of eastern Ohio along the western edge of the Appalachian Plateaus Physiographic Province. The data collected from 1989-91 and presented in this report represent the third and final phase of a 7-year study to assess baseline water quality in Ohio's coal region during 1985-1991. During 1989-91, 246 samples from 41 streamwater sites were collected periodically from a long-term site network. Ranges and medians of measurements made at the long-term streamwater sites were following: specific conductance, 270 to 5,170 and 792 microsiemens per centimeter at 25 degrees Celsius; pH, 2.7 to 9.1 and 7.8; alkalinity, 1 to 391 and 116 mg/L (milligrams per liter). Ranges and medians of laboratory analyses of the same samples were the following: dissolved sulfate, 13 to 2,100 and 200 mg/L; dissolved aluminum, <10 to 17,000 and 300 ? /L (micrograms per liter); dissolved iron, <10 to 53,000 and 60 ? /L; and dissolved manganese, <10 to 17,000 and 295 ? /L. The ranges for concentrations of total recoverable aluminum, iron, and manganese were similar to the ranges of concentrations found for dissolved constituents. Medians of total recoverable aluminum and iron were about 10 times greater than the medians of dissolved aluminum and iron. During 1989-91, once-only sample collections were done at 45 streamwater sites in nine basins chosen for synoptic sampling. At several sites in the Middle Hocking River basin and Leading Creek basin, water had low pH and high concentrations of dissolved aluminum, iron and manganese. These water-quality characteristics are commonly associated with ace mine drainage. Throughout the entire 7-year study (1985-91), medians for most constituents at the long-term streamwater-sampling sites were fairly consistent, despite the geographic diversity of the study area. Waters from several long-term sites, including several sites in Moxahala Creek and Middle Hocking River basins, had low pH and high concentrations of several constituents, including dissolved sulfate, iron, aluminum, and manganese; this combinations characteristics is indicitive of acid drainage from surface-mining operations. At many of the streamwater sites where concentration of these constituents were high, pH values in the neutral or alkaline range were indicative of stream buffering by carbonate rock or restoration of mined lands in the drainage system. The basins with sites in this category include Yellow and Cross Creeks and Wheeling Creek basins. Water quality at other sites showed little or no effects from surface mining. Ground-water samples collected during the last phase of the study (1989-91) were mostly from unconsolidated aquifers. The waters were generally hard to very hard and calcium bicarbonate in type. During the entire 7-year study period, medians of pH in ground-water samples varied little, and most values were in the alkaline range. Except for a few sites where concentrations of dissolved sulfate exceeded 250 mg/L and concentrations of total recoverable and dissolved iron and manganese exceeded 1,000 ? /L, the quality of ground water at the wells sampled in the study area showed little effect from coal mining.

Effects of soil pH on the Vicia-micronucleus genotoxicity assay.

PubMed

Dhyèvre, Adrien; Foltête, Anne Sophie; Aran, Delphine; Muller, Serge; Cotelle, Sylvie

2014-11-01

In the field of contaminated sites and soil management, chemical analyses only bring typological data about pollution. As far as bioavailability and effects on organisms are concerned, we need ecotoxicology tools. In this domain, among many existing tests, we chose to study genotoxicity because it is a short-term endpoint with long-term consequences. The aim of this study is to assess the effects of soil pH on the results of the Vicia faba root tip micronucleus test for the two following reasons: (i) to define the pH range within which the test can be performed without modifying the soil to be tested, within the framework of the ISO standard of the test and (ii) to provides information about the effects of the pH on the genotoxic potential of soils. In this context, we modified the pH of a standard soil with HCl or NaOH and we spiked the matrix with copper (2, 4 and 8 mmol kg(-1) dry soil) or with maleic hydrazide, an antigerminative chemical (5, 10 and 20 μmol kg(-1) dry soil). We concluded that the pH had no effect on the mitotic index or micronucleus frequency in the root cells of the negative controls: extreme pH values did not induce micronucleus formation in root cells. Moreover, according to our results, the Vicia-micronucleus test can be performed with pH values ranging between 3.2 and 9.0, but in the ISO 29200 "Soil quality--assessment of genotoxic effects on higher plants--V. faba micronucleus test" we recommended to use a control soil with a pH value ranging between 5 and 8 for a more accurate assessment of chemical genotoxicity. We also found that acid pH could increase the genotoxic potential of pollutants, especially heavy metals. With hydrazide maleic spiked soil, plants were placed in a situation of double stress, i.e. toxicity caused by extreme pH values and toxicity induced by the pollutant. Copyright © 2014 Elsevier B.V. All rights reserved.

A Long-term Forest Fertilization Experiment to Understand Ecosystem Responses to Atmospheric Nitrogen Deposition

NASA Astrophysics Data System (ADS)

Baron, J.; Advani, S. M.; Allen, J.; Boot, C.; Denef, K.; Denning, S.; Hall, E.; Moore, J. C.; Reuth, H.; Ryan, M. G.; Shaw, E.

2016-12-01

Long-term field experiments can reveal changes in ecosystem processes that may not be evident in short-term studies. Short-term measurements or experiments may have narrower objectives or unrealistic treatments in order to see a change, whereas long-term studies can reveal complex interactions that take longer to manifest. We report results from a long-term experiment (1996 to present) in subalpine forests to simulate the consequences of sustained atmospheric nitrogen (N) deposition. Loch Vale watershed in Rocky Mountain National Park, the location of the experiment, has received an order of magnitude greater atmospheric N deposition than estimated background since mid-20th Century. Augmenting that, in 1996 we began adding 25 kg NH4NO3 ha-1 yr-1 to three 30m x 30m old-growth Engelmann spruce and subalpine fir plots. Treated stands were matched by nearby controls. N addition caused rapid leaching of nitrate and cations from soils, and increased N mineralization and nitrification rates. These observations in the fertilized plots have been sustained over time. Soluble aluminum concentrations do not differ significantly between fertilized and control plots, but treated soils are now markedly more acidic (pH of 4.7) than original soil and controls (pH of 5.1); further acidification might increase aluminum leaching. Effects on soil carbon were complex, mediated by reductions in total microbial biomass, decreases in arbuscular mychorrizal and saprotropic fungi, and increased potential rates of N enzyme degrading activities. Initial soil C:N of 24 was lower than similar soils in low N deposition stands (C:N of 36). The C:N declined to 22 with treatment. Fertilized plots lost 11% soil C, but the mechanism is unclear. We did not measure changes in C inputs from litter, microbial biomass, or plant uptake, but there was no change in summer CO2 flux, measured in 2003, 2004, and 2014. Leaching of DOC from fertilized plots was elevated throughout the experiment, providing one pathway for C loss. The soil microfauna was dominated by nematodes; plant parasites and bacterial and fungal feeders were more abundant in fertilized plots than in controls, with fewer predaceous and omnivorous nematodes. Overall, N fertilization altered soil biogeochemical characteristics, soil food webs, and C cycling.

Long-term cryopreservation of sperm from Mandarin fish Siniperca chuatsi.

PubMed

Ding, Shuyan; Ge, Jiachun; Hao, Chen; Zhang, Mingsheng; Yan, Weihui; Xu, Zhiqiang; Pan, Jianlin; Chen, Songlin; Tian, Yongsheng; Huang, Yahong

2009-07-01

In order to develop cryopreservation techniques for long-term preserving the sperm of Mandarin fish Siniperca chuatsi, we examined the effects of various extender and cryopreservation on post-thaw motility. We found the optimal freezing procedures for the Mandarin fish sperm is diluting the semen in D-15 extender, chilling it to 4 degrees C, adding ME2SO to a final concentration of 10% (v/v), then transferring the semen in cryotubes, holding the cryotubes for 10 min at 6 cm (about -180 degrees C) above the surface of liquid nitrogen, for 5 min on the surface of liquid nitrogen, and finally plunged into liquid nitrogen. After thawed at 37 degrees C for 60s, the sperm had the highest post-thaw motility (96.00+/-1.73%). The optimal fertilization procedures for the frozen sperm is mixing the eggs with sperm, then adding 1 ml of swimming medium (SM=45 mM NaCl+5 mM KCl+20mM Tris-HCl, pH 8.0) immediately. At the sperm/egg ratio of 100,000:1, the fertilization rate and the hatching rate of the frozen sperm cryopreserved for 1 week or 1 year in liquid nitrogen (66.01+/-5.14% and 54.76+/-4.40% & 62.97+/-14.28% and 52.58+/-11.17%) were similar to that of fresh sperm (69.42+/-8.11% and 59.82+/-5.27%) (p>0.05). This is the first report that the Mandarin fish (S. chuatsi) sperm can successfully fertilized eggs after long-term cryopreservation.

pH Sensitive Microcapsules for Delivery of Corrosion Inhibitors

NASA Technical Reports Server (NTRS)

Li, Wenyan; Calle, Luz M.

2006-01-01

A considerable number of corrosion problems can be solved by coatings. However, even the best protective coatings can fail by allowing the slow diffusion of oxygen and moisture to the metal surface. Corrosion accelerates when a coating delaminates. Often, the problems start when microscopic nicks or pits on the surface develop during manufacturing or through wear and tear. This problem can be solved by the incorporation of a self-healing function into the coating. Several new concepts are currently under development to incorporate this function into a coating. Conductive polymers, nanoparticles, and microcapsules are used to release corrosion-inhibiting ions at a defect site. The objective of this investigation is to develop a smart coating for the early detection and inhibition of corrosion. The dual function of this new smart coating system is performed by pH-triggered release microcapsules. The microcapsules can be used to deliver healing agents to terminate the corrosion process at its early stage or as corrosion indicators by releasing dyes at the localized corrosion sites. The dyes can be color dyes or fluorescent dyes, with or without pH sensitivity. Microcapsules were formed through the interfacial polymerization process. The average size of the microcapsules can be adjusted from 1 to 100 micron by adjusting the emulsion formula and the microcapsule forming conditions. A typical microcapsule size is around 10 microns with a narrow size distribution. The pH sensitivity of the microcapsule can also be controlled by adjusting the emulsion formula and the polymerization reaction time. Both corrosion indicator (pH indicator) and corrosion inhibitor containing microcapsules were formed and incorporated into paint systems. Test panels of selected steels and aluminum alloys were painted using these paints. Testing of compatibility between the microcapsule system and different paint systems are in progress. Initial experiments with the microcapsule containing paint show visible color changes at induced corrosion sites and improvement of corrosion protection. Further investigation of the performance of the coating using electrochemical techniques and long term exposure are currently underway.

Peroral Endoscopic Myotomy for Esophageal Achalasia: Outcomes of the First 100 Patients With Short-term Follow-up.

PubMed

Familiari, Pietro; Gigante, Giovanni; Marchese, Michele; Boskoski, Ivo; Tringali, Andrea; Perri, Vincenzo; Costamagna, Guido

2016-01-01

Aim of this study is to report the mid-term outcomes of a large series of patients treated with peroral endoscopic myotomy (POEM) in a single European center. POEM is a recently developed treatment of achalasia, which combines the efficacy of surgical myotomy, with the benefits of an endoscopic procedure. Previous studies, including few patients with a short-term follow-up, showed excellent results on dysphagia relief. The first 100 adult patients treated in a single tertiary referral center were retrospectively identified and included in this study (41 men, mean age 48.4 years). Patients were treated according to a standard technique. Follow-up data, including clinical evaluation, and results of esophagogastroduodenoscopy (EGD), manometry, and pH monitoring were collected and analyzed. POEM was completed in 94% of patients. Mean operative time was 83 minutes (49-140  minutes). No complications occurred. Patients were fed after a median of 2 days (1-4 days). A mean follow-up of 11 months (3-24 months) was available for 92 patients. Clinical success was documented in 94.5% of patients. Twenty-four-hour pH monitoring documented Gastro-Esophageal Reflux Disease (GERD) in 53.4% of patients. However, only a minority of patients had heartburn (24.3%) or esophagitis (27.4%), and these patients were successfully treated with proton-pump inhibitors. Our results confirm the efficacy of POEM in a large series of patients, with a mean follow-up of 11 months. Should our results be confirmed by long-term follow-up studies, POEM may become one of the first-line therapies of achalasia in the next future.

Sequential Use of Second-Generation Tyrosine Kinase Inhibitor Treatment and Intensive Chemotherapy Induced Long-Term Complete Molecular Response in Imatinib-Resistant CML Patient Presenting as a Myeloid Blast Crisis

PubMed Central

Uchiyama, Tatsuki; Mizumoto, Chisaki; Takeoka, Tomoharu; Tomo, Kenjiro; Ohno, Tatsuharu

2017-01-01

Myeloid blast crisis of chronic myeloid leukemia (CML-MBC) is rarely seen at presentation and has a poor prognosis. There is no standard therapy for CML-MBC. It is often difficult to distinguish CML-MBC from acute myeloid leukemia expressing the Philadelphia chromosome (Ph+ AML). We present a case in which CML-MBC was seen at the initial presentation in a 75-year-old male. He was treated with conventional AML-directed chemotherapy followed by imatinib mesylate monotherapy, which failed to induce response. However, he achieved long-term complete molecular response after combination therapy involving dasatinib, a second-generation tyrosine kinase inhibitor, and conventional chemotherapy. PMID:29391957

Keratinophilic fungi isolated from soils of long-term fold-grazed, degraded pastures in national parks of Slovakia.

PubMed

Javoreková, Soňa; Labuda, Roman; Maková, Jana; Novák, Ján; Medo, Juraj; Majerčíková, Kamila

2012-09-01

A total of 939 isolates of 11 genera representing 15 species of keratinophilic fungi were isolated and identified from the soils of three long-term fold-grazed pastures in national parks of Slovakia (Pod Ploskou, Strungový príslop, and Pod Kečkou) and one non-fold-grazed pasture in sierra Stolicke vrchy (Diel) using the hair-baiting technique. Keratinophilic fungi were present in all soil samples with a prevalence of Trichophyton ajelloi and Paecilomyces lilacinus. These fungi were more abundant in soil from fold-grazed pasture (Strungový príslop) compared to non-fold-grazed pasture (Diel). The occurrence of the other keratinophilic fungi was substantially lower, likely because of low pH in some soils.

Large natural pH, CO2 and O2 fluctuations in a temperate tidal salt marsh on diel, seasonal, and interannual time scales

USGS Publications Warehouse

Baumann, Hannes; Wallace, Ryan; Tagliaferri, Tristen N.; Gobler, Christopher J.

2014-01-01

Coastal marine organisms experience dynamic pH and dissolved oxygen (DO) conditions in their natural habitats, which may impact their susceptibility to long-term anthropogenic changes. Robust characterizations of all temporal scales of natural pH and DO fluctuations in different marine habitats are needed; however, appropriate time series of pH and DO are still scarce. We used multiyear (2008–2012), high-frequency (6 min) monitoring data to quantify diel, seasonal, and interannual scales of pH and DO variability in a productive, temperate tidal salt marsh (Flax Pond, Long Island, US). pHNBS and DO showed strong and similar seasonal patterns, with average (minimum) conditions declining from 8.2 (8.1) and 12.5 (11.4) mg l−1 at the end of winter to 7.6 (7.2) and 6.3 (2.8) mg l−1 in late summer, respectively. Concomitantly, average diel fluctuations increased from 0.22 and 2.2 mg l−1 (February) to 0.74 and 6.5 mg l−1 (August), respectively. Diel patterns were modulated by tides and time of day, eliciting the most extreme minima when low tides aligned with the end of the night. Simultaneous in situ pCO2 measurements showed striking fluctuations between ∼330 and ∼1,200 (early May), ∼2,200 (mid June), and ∼4,000 μatm (end of July) within single tidal cycles. These patterns also indicate that the marsh’s strong net heterotrophy influences its adjacent estuary by ‘outwelling’ acidified and hypoxic water during ebb tides. Our analyses emphasize the coupled and fluctuating nature of pH and DO conditions in productive coastal and estuarine environments, which have yet to be adequately represented by experiments.

Titratable acidity of beverages influences salivary pH recovery.

PubMed

Tenuta, Livia Maria Andaló; Fernández, Constanza Estefany; Brandão, Ana Carolina Siqueira; Cury, Jaime Aparecido

2015-01-01

A low pH and a high titratable acidity of juices and cola-based beverages are relevant factors that contribute to dental erosion, but the relative importance of these properties to maintain salivary pH at demineralizing levels for long periods of time after drinking is unknown. In this crossover study conducted in vivo, orange juice, a cola-based soft drink, and a 10% sucrose solution (negative control) were tested. These drinks differ in terms of their pH (3.5 ± 0.04, 2.5 ± 0.05, and 5.9 ± 0.1, respectively) and titratable acidity (3.17 ± 0.06, 0.57 ± 0.04 and < 0.005 mmols OH- to reach pH 5.5, respectively). Eight volunteers with a normal salivary flow rate and buffering capacity kept 15 mL of each beverage in their mouth for 10 s, expectorated it, and their saliva was collected after 15, 30, 45, 60, 90, and 120 s. The salivary pH, determined using a mini pH electrode, returned to the baseline value at 30 s after expectoration of the cola-based soft drink, but only at 90 s after expectoration of the orange juice. The salivary pH increased to greater than 5.5 at 15 s after expectoration of the cola drink and at 30 s after expectoration of the orange juice. These findings suggest that the titratable acidity of a beverage influences salivary pH values after drinking acidic beverages more than the beverage pH.

Effects of long-term poultry litter application on phosphorus soil chemistry and runoff water quality.

PubMed

Reiter, Mark S; Daniel, Tommy C; DeLaune, Paul B; Sharpley, Andrew N; Lory, John A

2013-11-01

Continuous application of poultry litter (PL) significantly changes many soil properties, including soil test P (STP); Al, Fe, and Ca concentrations; and pH, which can affect the potential for P transport in surface runoff water. We conducted rainfall simulations on three historically acidic silt loam soils in Arkansas, Missouri, and Virginia to establish if long-term PL applications would affect soil inorganic P fractions and the resulting dissolved reactive P (DRP) in runoff water. Soil samples (0-5 cm depth) were taken to find sites ranging in Mehlich-3 STP from 20 to 1154 mg P kg. Simulated rainfall events were conducted on 3-m plots at 6.7 cm h, and runoff was collected for 30 min. Correlation between Mehlich-3 and runoff DRP indicated a linear relationship to 833 mg Mehlich-3 P kg. As Mehlich-3 STP increased, a concomitant increase in soil pH and Ca occurred on all soils. Soil P fractionation demonstrated that, as Mehlich-3 STP generally increased above 450 mg P kg (from high to very high), the easily soluble and loosely bound P fractions decreased by 3 to 10%. Water-insoluble complexes of P bound to Al and Ca were the main drivers in the reduction of DRP in runoff, accounting for up to 43 and 38% of total P, respectively. Basing runoff DRP concentration projections solely on Mehlich-3 STP may overestimate runoff P losses from soils receiving long-term PL applications due to dissolution of water-insoluble Ca-P compounds. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Arsenic speciation and reactivity in poultry litter

USGS Publications Warehouse

Arai, Y.; Lanzirotti, A.; Sutton, S.; Davis, J.A.; Sparks, D.L.

2003-01-01

Recent U.S. government action to lower the maximum concentration levels (MCL) of total arsenic (As) (10 ppb) in drinking water has raised serious concerns about the agricultural use of As-containing biosolids such as poultry litter (PL). In this study, solid-state chemical speciation, desorbability, and total levels of As in PL and long-term amended soils were investigated using novel synchrotronbased probing techniques (microfocused (??) synchrotron X-ray fluorescence (SXRF) and ??-X-ray absorption near-edge structure (XANES) spectroscopies) coupled with chemical digestion and batch experiments. The total As levels in the PL were as high as ???50 mg kg-1, and As(II/III and V) was always concentrated in abundant needle-shaped microscopic particles (???20/ ??m x 850 ??m) associated with Ca, Cu, and Fe and to a lesser extent with S, CI, and Zn. Postedge XANES features of litter particles are dissimilar to those of the organo-As(V) compound in poultry feed (i.e., roxarsone), suggesting possible degradation/transformation of roxarsone in the litter and/or in poultry digestive tracts. The extent of As desorption from the litter increased with increasing time and pH from 4.5 to 7, but at most 15% of the total As was released after 5 d at pH 7, indicating the presence of insoluble phases and/or strongly retained soluble compounds. No significant As accumulation (< 15 mg kg-1) was found in long-term PL-a mended agricultural surface soils. This suggests that As in the PL may have undergone surface and subsurface transport processes. Our research results raise concerns about long-term PL amendment effects on As contamination in surrounding soilwater environments.

Recovery from chronic and snowmelt acidification: Long-term trends in stream and soil water chemistry at the Hubbard Brook Experimental Forest, New Hampshire, USA

NASA Astrophysics Data System (ADS)

Fuss, Colin B.; Driscoll, Charles T.; Campbell, John L.

2015-11-01

Atmospheric acid deposition of sulfate and nitrate has declined markedly in the northeastern United States due to emissions controls. We investigated long-term trends in soil water (1984-2011) and stream water (1982-2011) chemistry along an elevation gradient of a forested watershed to evaluate the progress of recovery of drainage waters from acidic deposition at the Hubbard Brook Experimental Forest in the White Mountains of New Hampshire, USA. We found slowed losses of base cations from soil and decreased mobilization of dissolved inorganic aluminum. Stream water pH at the watershed outlet increased at a rate of 0.01 units yr-1, and the acid neutralizing capacity (ANC) gained 0.88 µeq L-1 yr-1. Dissolved organic carbon generally decreased in stream water and soil solutions, contrary to trends observed at many North American and European sites. We compared whole-year hydrochemical trends with those during snowmelt, which is the highest-flow and lowest ANC period of the year, indicative of episodic acidification. Stream water during snowmelt had long-term trends of increasing ANC and pH at a rate very similar to the whole-year record, with closely related steady decreases in sulfate. A more rapid decline in stream water nitrate during snowmelt compared with the whole-year trend may be due, in part, to the marked decrease in atmospheric nitrate deposition during the last decade. The similarity between the whole-year trends and those of the snowmelt period is an important finding that demonstrates a consistency between recovery from chronic acidification during base flow and abatement of snowmelt acidification.

Fostering Humane Care of Dying Persons in Long-Term Care. Guidebook for Staff Development Instructors.

ERIC Educational Resources Information Center

Wilson, Sarah A.; Daley, Barbara

This guide is intended for staff development instructors responsible for inservice education on the topic of fostering humane care for dying persons in long-term care. The introduction discusses the guide's development based on input from administrators, staff, and families of residents in long-term care facilities and focus group interviews in…

Multi-decadal Records of Ocean Acidification and Toxic Heavy Metal Pollution in Coral Cores from Oahu, Hawaii

NASA Astrophysics Data System (ADS)

Stewart, J.; Tolliver, R.; Field, D. B.; Young, C.; Stafford, G.; Day, R. D.

2016-12-01

Monitoring of the physiological/ecological response of marine calcifying organisms to the combination of lower pH and toxic metal pollutants (e.g. Cu and Sn from boat anti-fouling paints) into the oceans requires detailed knowledge of the rates and spatial distribution of ocean acidification (OA) and trace metal composition over time. Yet, measurement of metal concentrations and carbonate system parameters in the modern ocean from seawater bottle data is patchy (e.g. CDIAC/WOCE Carbon Data; http://cdiac.ornl.gov) and there remain few long-term surface water pH monitoring stations; the two longest continuous records of ocean pH extend back less than 30 years (Bermuda - BATS, 31°40'N, 64°10'W; Hawaii - HOTs, 22°45'N, 158°00'W). Much attention has therefore been focused on trace metal and ocean carbonate system proxy development to allow reconstruction of seawater metal content and pH in the past. Of particular promise is the boron isotope (δ11B) pH-proxy measured in marine calcifying organisms such as coral that can be cored enabling multi-decadal, annual-resolution, records of trace element incorporation and seawater pH to be generated. Here we present continuous Cu/Ca and Sn/Ca records in addition to δ11B data from three coral cores of Porites lutea. collected from waters proximal to Oahu, Hawaii. The diagenetic integrity of samples is verified using X-ray diffraction to assess the degree of calcite replacement. These cores reach a maximum depth of 80 cm and represent approximately 80 years of coral growth and seawater chemistry.

Bioengineering vascularized tissue constructs using an injectable cell-laden enzymatically crosslinked collagen hydrogel derived from dermal extracellular matrix

PubMed Central

Kuo, Kuan-Chih; Lin, Ruei-Zeng; Tien, Han-Wen; Wu, Pei-Yun; Li, Yen-Cheng; Melero-Martin, Juan M.; Chen, Ying-Chieh

2015-01-01

Tissue engineering promises to restore or replace diseased or damaged tissue by creating functional and transplantable artificial tissues. The development of artificial tissues with large dimensions that exceed the diffusion limitation will require nutrients and oxygen to be delivered via perfusion instead of diffusion alone over a short time period. One approach to perfusion is to vascularize engineered tissues, creating a de novo three-dimensional (3D) microvascular network within the tissue construct. This significantly shortens the time of in vivo anastomosis, perfusion and graft integration with the host. In this study, we aimed to develop injectable allogeneic collagen-phenolic hydroxyl (collagen-Ph) hydrogels that are capable of controlling a wide range of physicochemical properties, including stiffness, water absorption and degradability. We tested whether collagen-Ph hydrogels could support the formation of vascularized engineered tissue graft by human blood-derived endothelial colony-forming cells (ECFCs) and bone marrow-derived mesenchymal stem cells (MSC) in vivo. First, we studied the growth of adherent ECFCs and MSCs on or in the hydrogels. To examine the potential formation of functional vascular networks in vivo, a liquid pre-polymer solution of collagen-Ph containing human ECFCs and MSCs, horseradish peroxidase and hydrogen peroxide was injected into the subcutaneous space or abdominal muscle defect of an immunodeficient mouse before gelation, to form a 3D cell-laden polymerized construct. These results showed that extensive human ECFC-lined vascular networks can be generated within 7 days, the engineered vascular density inside collagen-Ph hydrogel constructs can be manipulated through refinable mechanical properties and proteolytic degradability, and these networks can form functional anastomoses with the existing vasculature to further support the survival of host muscle tissues. Finally, optimized conditions of the cell-laden collagen-Ph hydrogel resulted in not only improving the long-term differentiation of transplanted MSCs into mineralized osteoblasts, but the collagen-Ph hydrogel also improved an increased of adipocytes within the vascularized bioengineered tissue in a mouse after 1 month of implantation. PMID:26348142

Coral calcification mechanisms facilitate adaptive responses to ocean acidification.

PubMed

Schoepf, Verena; Jury, Christopher P; Toonen, Robert J; McCulloch, Malcolm T

2017-12-06

Ocean acidification (OA) is a pressing threat to reef-building corals, but it remains poorly understood how coral calcification is inhibited by OA and whether corals could acclimatize and/or adapt to OA. Using a novel geochemical approach, we reconstructed the carbonate chemistry of the calcifying fluid in two coral species using both a pH and dissolved inorganic carbon (DIC) proxy (δ 11 B and B/Ca, respectively). To address the potential for adaptive responses, both species were collected from two sites spanning a natural gradient in seawater pH and temperature, and then subjected to three pH T levels (8.04, 7.88, 7.71) crossed by two temperatures (control, +1.5°C) for 14 weeks. Corals from the site with naturally lower seawater pH calcified faster and maintained growth better under simulated OA than corals from the higher-pH site. This ability was consistently linked to higher pH yet lower DIC values in the calcifying fluid, suggesting that these differences are the result of long-term acclimatization and/or local adaptation to naturally lower seawater pH. Nevertheless, all corals elevated both pH and DIC significantly over seawater values, even under OA. This implies that high pH upregulation combined with moderate levels of DIC upregulation promote resistance and adaptive responses of coral calcification to OA. © 2017 The Author(s).

Long-Term Impacts of a Faculty Development Program for the Internationalization of Curriculum in Higher Education

ERIC Educational Resources Information Center

Urban, Emily; Navarro, Maria; Borron, Abigail

2017-01-01

Faculty development programs for internationalization of the curriculum in higher education are often evaluated for short- and medium-term outcomes, but more long-term assessments are needed to determine impact. This study examined the long-term (6 years) impacts on faculty from colleges of agriculture after participating in a one-year…

Design and validation of a new ratiometric intracellular pH imaging probe using lanthanide-doped upconverting nanoparticles.

PubMed

Du, Shuoren; Hernández-Gil, Javier; Dong, Hao; Zheng, Xiaoyu; Lyu, Guangming; Bañobre-López, Manuel; Gallo, Juan; Sun, Ling-Dong; Yan, Chun-Hua; Long, Nicholas J

2017-10-17

pH homeostasis is strictly controlled at a subcellular level. A deregulation of the intra/extra/subcellular pH environment is associated with a number of diseases and as such, the monitoring of the pH state of cells and tissues is a valuable diagnostic tool. To date, only a few tools have been developed to measure the pH in living cells with the spatial resolution needed for intracellular imaging. Among the techniques available, only optical imaging offers enough resolution and biocompatibility to be proposed for subcellular pH monitoring. We present herein a ratiometric probe based on upconversion nanoparticles modified with a pH sensitive moiety for the quantitative imaging of pH at the subcellular level in living cells. This system provides the properties required for live cell quantitative imaging i.e. positive cellular uptake, biocompatibility, long wavelength excitation, sensitive response to pH within a biologically relevant range, and self-referenced signal.

Health and disability pension--an intersection of disease, psychosocial stress and gender. Long term follow up of persons with impairment of the locomotor system.

PubMed

Kaiser, Per-Olof; Mattsson, Bengt; Marklund, Staffan; Wimo, Anders

2008-01-01

To evaluate the outcome after 1, 2, 3 and 10 years of rehabilitation conducted by the Swedish Social Insurance Office, in relation to socioeconomic, psychosocial and gender aspects. A retro and prospective study of 372 individuals rehabilitated by the National Swedish Insurance Office 1993-1994. Diagnosis, socio demographic data, Sense of Coherence and Perceived Health were compared with register data in terms of sickness benefit and disability pension up to 10 years. At the 10 year follow up 52% of the men and 57% of the women were granted any kind of DP. 82% of the men with low PH and women with a PM or a low PH had any kind of benefit 10 year after rehabilitation started. High age and low PH increases the risk of a full DP after 3 as well as 10 years for both men and women. At the 3 year follow up however, low education was also important for a full DP for men and having a Psychosocial Marker for women. The factors civil status and kind of profession did not significantly relate to a full DP after 10 year. In different ways factors as age, education, psychosocial stress, Sense of Coherence and Perceived Health mediate the rehabilitation process in significant ways by affecting the manifestation of the disease itself and/or via the context in which the rehabilitation takes place, in combination with individual factors that acts over a long time. Age and Perceived Health seems to be the most important factors of them all.

A direct CO2 control system for ocean acidification experiments: testing effects on the coralline red algae Phymatolithon lusitanicum.

PubMed

Sordo, Laura; Santos, Rui; Reis, Joao; Shulika, Alona; Silva, Joao

2016-01-01

Most ocean acidification (OA) experimental systems rely on pH as an indirect way to control CO 2 . However, accurate pH measurements are difficult to obtain and shifts in temperature and/or salinity alter the relationship between pH and p CO 2 . Here we describe a system in which the target p CO 2 is controlled via direct analysis of p CO 2 in seawater. This direct type of control accommodates potential temperature and salinity shifts, as the target variable is directly measured instead of being estimated. Water in a header tank is permanently re-circulated through an air-water equilibrator. The equilibrated air is then routed to an infrared gas analyzer (IRGA) that measures p CO 2 and conveys this value to a Proportional-Integral-Derivative (PID) controller. The controller commands a solenoid valve that opens and closes the CO 2 flush that is bubbled into the header tank. This low-cost control system allows the maintenance of stabilized levels of p CO 2 for extended periods of time ensuring accurate experimental conditions. This system was used to study the long term effect of OA on the coralline red algae Phymatolithon lusitanicum . We found that after 11 months of high CO 2 exposure, photosynthesis increased with CO 2 as opposed to respiration, which was positively affected by temperature. Results showed that this system is adequate to run long-term OA experiments and can be easily adapted to test other relevant variables simultaneously with CO 2 , such as temperature, irradiance and nutrients.

A direct CO2 control system for ocean acidification experiments: testing effects on the coralline red algae Phymatolithon lusitanicum

PubMed Central

Santos, Rui; Reis, Joao; Shulika, Alona

2016-01-01

Most ocean acidification (OA) experimental systems rely on pH as an indirect way to control CO2. However, accurate pH measurements are difficult to obtain and shifts in temperature and/or salinity alter the relationship between pH and pCO2. Here we describe a system in which the target pCO2 is controlled via direct analysis of pCO2 in seawater. This direct type of control accommodates potential temperature and salinity shifts, as the target variable is directly measured instead of being estimated. Water in a header tank is permanently re-circulated through an air-water equilibrator. The equilibrated air is then routed to an infrared gas analyzer (IRGA) that measures pCO2 and conveys this value to a Proportional-Integral-Derivative (PID) controller. The controller commands a solenoid valve that opens and closes the CO2 flush that is bubbled into the header tank. This low-cost control system allows the maintenance of stabilized levels of pCO2 for extended periods of time ensuring accurate experimental conditions. This system was used to study the long term effect of OA on the coralline red algae Phymatolithon lusitanicum. We found that after 11 months of high CO2 exposure, photosynthesis increased with CO2 as opposed to respiration, which was positively affected by temperature. Results showed that this system is adequate to run long-term OA experiments and can be easily adapted to test other relevant variables simultaneously with CO2, such as temperature, irradiance and nutrients. PMID:27703853

Observing climate change trends in ocean biogeochemistry: when and where.

PubMed

Henson, Stephanie A; Beaulieu, Claudie; Lampitt, Richard

2016-04-01

Understanding the influence of anthropogenic forcing on the marine biosphere is a high priority. Climate change-driven trends need to be accurately assessed and detected in a timely manner. As part of the effort towards detection of long-term trends, a network of ocean observatories and time series stations provide high quality data for a number of key parameters, such as pH, oxygen concentration or primary production (PP). Here, we use an ensemble of global coupled climate models to assess the temporal and spatial scales over which observations of eight biogeochemically relevant variables must be made to robustly detect a long-term trend. We find that, as a global average, continuous time series are required for between 14 (pH) and 32 (PP) years to distinguish a climate change trend from natural variability. Regional differences are extensive, with low latitudes and the Arctic generally needing shorter time series (<~30 years) to detect trends than other areas. In addition, we quantify the 'footprint' of existing and planned time series stations, that is the area over which a station is representative of a broader region. Footprints are generally largest for pH and sea surface temperature, but nevertheless the existing network of observatories only represents 9-15% of the global ocean surface. Our results present a quantitative framework for assessing the adequacy of current and future ocean observing networks for detection and monitoring of climate change-driven responses in the marine ecosystem. © 2016 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

Effect of long-term fertilization strategies on bacterial community composition in a 35-year field experiment of Chinese Mollisols.

PubMed

Ma, Mingchao; Zhou, Jing; Ongena, Marc; Liu, Wenzheng; Wei, Dan; Zhao, Baisuo; Guan, Dawei; Jiang, Xin; Li, Jun

2018-02-13

Bacteria play vital roles in soil biological fertility; however, it remains poorly understood about their response to long-term fertilization in Chinese Mollisols, especially when organic manure is substituted for inorganic nitrogen (N) fertilizer. To broaden our knowledge, high-throughput pyrosequencing and quantitative PCR were used to explore the impacts of inorganic fertilizer and manure on bacterial community composition in a 35-year field experiment of Chinese Mollisols. Soils were collected from four treatments: no fertilizer (CK), inorganic phosphorus (P) and potassium (K) fertilizer (PK), inorganic P, K, and N fertilizer (NPK), and inorganic P and K fertilizer plus manure (MPK). All fertilization differently changed soil properties. Compared with CK, the PK and NPK treatments acidified soil by significantly decreasing soil pH from 6.48 to 5.53 and 6.16, respectively, while MPK application showed no significant differences of soil pH, indicating alleviation of soil acidification. Moreover, all fertilization significantly increased soil organic matter (OM) and soybean yields, with the highest observed under MPK regime. In addition, the community composition at each taxonomic level varied considerably among the fertilization strategies. Bacterial taxa, associated with plant growth promotion, OM accumulation, disease suppression, and increased soil enzyme activity, were overrepresented in the MPK regime, while they were present at low abundant levels under NPK treatment, i.e. phyla Proteobacteria and Bacteroidetes, class Alphaproteobacteria, and genera Variovorax, Chthoniobacter, Massilia, Lysobacter, Catelliglobosispora and Steroidobacter. The application of MPK shifted soil bacterial community composition towards a better status, and such shifts were primarily derived from changes in soil pH and OM.

Characterization of Anodic Aluminum Oxide Membrane with Variation of Crystallizing Temperature for pH Sensor.

PubMed

Yeo, Jin-Ho; Lee, Sung-Gap; Jo, Ye-Won; Jung, Hye-Rin

2015-11-01

We fabricated electrolyte-dielectric-metal (EDM) device incorporating a high-k Al2O3 sensing membrane from a porous anodic aluminum oxide (AAO) using a two step anodizing process for pH sensors. In order to change the properties of the AAO template, the crystallizing temperature was varied from 400 degrees C to 700 degrees C over 2 hours. The structural properties were observed by field emission scanning electron microscopy (FE-SEM). The pH sensitivity increased with an increase in the crystallizing temperature from 400 degrees C to 600 degrees C. However at 700 degrees C, deformation occurred. The porous AAO sensor with a crystallizing temperature of 600 degrees C displayed the good sensitivity and long-term stability and the values were 55.7 mV/pH and 0.16 mV/h, respectively.

Lactic acid production from acidogenic fermentation of fruit and vegetable wastes.

PubMed

Wu, Yuanyuan; Ma, Hailing; Zheng, Mingyue; Wang, Kaijun

2015-09-01

This work focused on the lactic acid production from acidogenic fermentation of fruit and vegetable wastes treatment. A long term completely stirred tank reactor (CSTR) lasting for 50 days was operated at organic loading rate (OLR) of 11 gVS/(L d) and sludge retention time (SRT) of 3 days with pH controlled at 4.0 (1-24 day) and 5.0 (25-50 day). The results indicated that high amount of approximately 10-20 g/L lactic acid was produced at pH of 4.0 and the fermentation type converted from coexistence of homofermentation and heterofermentation into heterofermentation. At pH of 5.0, the hydrolysis reaction was improved and the total concentration of fermentation products increased up to 29.5 g COD/L. The heterofermentation was maintained, however, bifidus pathway by Bifidobacterium played an important role. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pulmonary hypertension in diffuse parenchymal lung diseases - is there any benefit of PAH-specific therapy?

PubMed

Szturmowicz, Monika; Kacprzak, Aneta; Kuś, Jan

2017-01-01

Pulmonary hypertension (PH) is diagnosed in 40-50% of the patients with end-stage diffuse parenchymal lung diseases (DPLD), and it is associated with significant worsening of life expectancy. Latest ERS/ESC guidelines recommend best available treatment of DPLD, and long-term oxygen therapy in the patients with PaO2 less than 60 mm Hg. Pulmonary arterial hypertension (PAH)-targeted drugs are not recommended in PH-DPLD patients, due to the risk of increasing the ventilation-perfusion mismatch, and consequently worsening of hypoxaemia. Nevertheless, PAH-oriented treatment may be beneficial to selected groups of patients. The authors try to find the answer to several important questions: is there any benefit of PAH-specific therapy in PH-DPLD, who should be the candidate for PAH-specific therapy, what class of drugs is most promising, and what outcome measures should be employed?

Mechanistic insights into iron redox transformations in the presence of natural organic matter: Impact of pH and light

NASA Astrophysics Data System (ADS)

Garg, Shikha; Jiang, Chao; David Waite, T.

2015-09-01

The various pathways contributing to the formation and decay of Fe(II) in the presence of Suwanee River Fulvic Acid (SRFA) in acidic solutions are investigated here both in the presence and absence of light and over the pH range of 3-5. Our results show that ligand to metal charge transfer (LMCT) is the dominant pathway for photochemical Fe(III) reduction and resultant Fe(II) formation over the pH range examined. In comparison, under non-irradiated conditions, Fe(III) reduction occurs, for the most part, as a result of the presence of hydroquinone-like moieties in SRFA. Irradiation of SRFA also results in the generation of both long-lived and short-lived Fe(II) oxidants with the long-lived Fe(II) oxidant similar to semiquinone-like radicals with these radicals formed via superoxide-mediated oxidation of the hydroquinone-like moieties present in SRFA. Dioxygen plays an important role in production of the long-lived Fe(II) oxidant since generation of superoxide occurs via reduction of dioxygen. The short-lived Fe(II) oxidant is similar to peroxyl radicals which are generated via hydroxylation of organic moieties. The overall rate of generation of both the short- and long-lived Fe(II) oxidants is dependent on pH with the generation rates of these oxidants increasing with increase in pH. Based on our experimental data, we have developed a kinetic model that satisfactorily describes all Fe transformations observed in SRFA solutions over the pH range 3-5 under non-irradiated, previously irradiated and continuously irradiated conditions. Fe species undergo continual cycling between Fe(II) and Fe(III) oxidation states with Fe(II)-Fe(III) turnover frequencies in the presence of 10 mg.L-1 SRFA of 17.3, 27.4 and 33.2 h-1 at pH 3, 3.5 and 4 on continuous photolysis compared to turnover frequencies of 1.9, 2.5 and 2.9 h-1 at pH 3, 3.5 and 4 in the dark.

Highly sensitive label-free dual sensor array for rapid detection of wound bacteria.

PubMed

Sheybani, Roya; Shukla, Anita

2017-06-15

Wound infections are a critical healthcare concern worldwide. Rapid and effective antibiotic treatments that can mitigate infection severity and prevent the spread of antibiotic resistance are contingent upon timely infection detection. In this work, dual electrochemical pH and cell-attachment sensor arrays were developed for the real-time spatial and temporal monitoring of potential wound infections. Biocompatible polymeric device coatings were integrated to stabilize the sensors and promote bacteria attachment while preventing non-specific cell and protein fouling. High sensitivity (bacteria concentration of 10 2 colony forming units (CFU)/mL and -88.1±6.3mV/pH over a pH range of 1-13) and stability over 14 days were achieved without the addition of biological recognition elements. The dual sensor array was demonstrated to successfully monitor the growth of both gram-positive (Staphylococcus aureus and Streptococcus pyogenes) and gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli) over time through lag and log growth phases and following antibiotic administration and in simulated shallow wounds conditions. The versatile fabrication methods utilized in sensor development, superior sensitivity, prolonged stability, and lack of non-specific sensor fouling may enable long-term in situ sensor array operation in low resource settings. Copyright © 2016 Elsevier B.V. All rights reserved.

Development of highly sensitive amperometric biosensor for glucose using carbon nanosphere/sodium alginate composite matrix for enzyme immobilization.

PubMed

Han, En; Li, Xia; Cai, Jian-Rong; Cui, Hai-Ying; Zhang, Xing-Ai

2014-01-01

In this study, we developed a highly sensitive amperometric biosensor for glucose detection based on glucose oxidase immobilized in a novel carbon nanosphere (CNS)/sodium alginate (SA) composite matrix. This hybrid material combined the advantages of CNS and natural biopolymer SA. This composite film was characterized by scanning electron microscope, electrochemical impedance spectroscopy and UV-vis, which indicated that the hybrid material was suitable for immobilization of glucose oxidase. Various experimental conditions were investigated that influenced the performance of the biosensor, such as pH, applied potential and temperature. Under the optimum conditions, the biosensor showed excellent performance for glucose over a wide linear concentration range from 1.0 × 10(-6) to 4.6 × 10(-3) M with a detection limit of 0.5 μM based on a signal-to-noise ratio of 3. Furthermore, the biosensor exhibited excellent long-term stability and satisfactory reproducibility.

Long-term trends in dissolved iron and DOC concentration linked to nitrate depletion in riparian soils

NASA Astrophysics Data System (ADS)

Musolff, Andreas; Selle, Benny; Fleckenstein, Jan H.; Oosterwoud, Marieke R.; Tittel, Jörg

2016-04-01

The instream concentrations of dissolved organic carbon (DOC) are rising in many catchments of the northern hemisphere. Elevated concentrations of DOC, mainly in the form of colored humic components, increase efforts and costs of drinking water purification. In this study, we evaluated a long-term dataset of 110 catchments draining into German drinking water reservoirs in order to assess sources of DOC and drivers of a potential long-term change. The average DOC concentrations across the wide range of different catchments were found to be well explained by the catchment's topographic wetness index. Higher wetness indices were connected to higher average DOC concentrations, which implies that catchments with shallow topography and pronounced riparian wetlands mobilize more DOC. Overall, 37% of the investigated catchments showed a significant long-term increase in DOC concentrations, while 22% exhibited significant negative trends. Moreover, we found that increasing trends in DOC were positively correlated to trends in dissolved iron concentrations at pH≤6 due to remobilization of DOC previously sorbed to iron minerals. Both, increasing trends in DOC and dissolve iron were found to be connected to decreasing trends and low concentrations of nitrate (below ~6 mg/L). This was especially observed in forested catchments where atmospheric N-depositions were the major source for nitrate availability. In these catchments, we also found long-term increases of phosphate concentrations. Therefore, we argue that dissolved iron, DOC and phosphate were jointly released under iron-reducing conditions when nitrate as a competing electron acceptor was too low in concentrations to prevent the microbial iron reduction. In contrast, we could not explain the observed increasing trends in DOC, iron and phosphate concentrations by the long-term trends of pH, sulfate or precipitation. Altogether this study gives strong evidence that both, source and long-term increases in DOC are primarily controlled by riparian wetland soils within the catchments. Here, the achievement of a long-term reduction in nitrogen deposition may in turn lead to a more pronounced iron reduction and a subsequent release of DOC and other iron-bound substances such as phosphate.

Sol-Gel Deposition of Iridium Oxide for Biomedical Micro-Devices

PubMed Central

Nguyen, Cuong M.; Rao, Smitha; Yang, Xuesong; Dubey, Souvik; Mays, Jeffrey; Cao, Hung; Chiao, Jung-Chih

2015-01-01

Flexible iridium oxide (IrOx)-based micro-electrodes were fabricated on flexible polyimide substrates using a sol-gel deposition process for utilization as integrated pseudo-reference electrodes for bio-electrochemical sensing applications. The fabrication method yields reliable miniature on-probe IrOx electrodes with long lifetime, high stability and repeatability. Such sensors can be used for long-term measurements. Various dimensions of sol-gel iridium oxide electrodes including 1 mm × 1 mm, 500 μm × 500 μm, and 100 μm × 100 μm were fabricated. Sensor longevity and pH dependence were investigated by immersing the electrodes in hydrochloric acid, fetal bovine serum (FBS), and sodium hydroxide solutions for 30 days. Less pH dependent responses, compared to IrOx electrodes fabricated by electrochemical deposition processes, were measured at 58.8 ± 0.4 mV/pH, 53.8 ± 1.3 mV/pH and 48 ± 0.6 mV/pH, respectively. The on-probe IrOx pseudo-reference electrodes were utilized for dopamine sensing. The baseline responses of the sensors were higher than the one using an external Ag/AgCl reference electrode. Using IrOx reference electrodes integrated on the same probe with working electrodes eliminated the use of cytotoxic Ag/AgCl reference electrode without loss in sensitivity. This enables employing such sensors in long-term recording of concentrations of neurotransmitters in central nervous systems of animals and humans. PMID:25686309

Assessment of inceptisols soil quality following long-term cropping in a calcareous environment.

PubMed

Rezapour, Salar; Samadi, A

2012-03-01

The combination of morphological, clay mineralogy, physicochemical, and fertilitical properties of inceptisols were compared for monitoring soil quality response following long-term agricultural activities. For this target, fifty-nine paired surface soils belonging to five subgroups of inceptisols from the major sugar beet growing area and the adjoining virgin lands were described, sampled, and analyzed. The soils were alkaline and calcareous as characterized by high pH, ranging from 7.2 to 8, and calcium carbonate equivalent, ranging from 60 to 300 g kg(-1). Following long-term sugar beet cultivation, morphological properties modifications were reflected as weakening of structure, hardening of consistency, and brightening of soil color. Although, the quantity of clay minerals did not significantly change through long-term cropping, some modifications in the XRD pattern of illite and smectite were observed in the cultivated soils compared to the adjoining virgin lands mainly as a result of potassium depletion. Without significant variation, sand content decreased by 4-55% and silt and clay increased by 3-22% and 2-15%, respectively, in the cultivated soils than to that of the virgin lands. Both negative and positive aspects of soil quality were reflected regarding soil chemical and fertilitical properties and the role of negative effects far exceeded the role of positive effects. Typic calcixerepts was known to be more degraded through a significant decrease (P ≤ 0.001) in mean value of soil organic carbon (a drop of 24%), total N (a drop of 23%), available K (a drop of 42%), exchangeable K (a drop of 45%), potassium adsorption ratio and potassium saturation ratio (a drop of 44% and 42%, respectively) and a significant increase (P ≤ 0.001) in EC (a rise of 53%). Soil quality index, calculated based on nine soil properties [coarse fragments, pH, SOC, total N, ESP, exchangeable cations (Ca, Mg, and K), and available phosphorus], indicated that 60% of the all soil types studied had negative changes, 20% had positive changes, and 20% produced no changes in soil heath.

Mechanisms of iodine release from iodoapatite in aqueous solution

NASA Astrophysics Data System (ADS)

Zhang, Z.; Wang, J.

2017-12-01

Immobilization of iodine-129 with waste forms in geological setting is challenging due to its extremely long half-life and high volatility in the environment. To evaluate the long-term performance of waste form, it is imperative to determine the release mechanism of iodine hosted in the waste form materials. This study investigated the iodine released from apatite structured waste form Pb9.85 (VO4)6 I1.7 to understand how diffusion and dissolution control the durability of apatite waste form. A standard semi-dynamic leach test was adopted in this study. Samples were exposed in fresh leachant periodically and the leachant was replaced after each interval. Each experiment was carried out in cap-sealed Teflon vessels under constant temperature (e.g. 90 °C). ICP-MS analysis on the reacted leachates shows that Pb and V were released constantly and congruently with the stoichiometric ratio of Pb/V. However, iodine release is incongruent and time dependent. The iodine release rate starts significantly higher than the corresponding stoichiometric value and gradually decreases, approaching the stoichiometric value. Therefore, a dual-mode mechanism is proposed to account for the iodine release from apatite, which is dominated by short-term diffusion and long-term dissolution processes. Additional tests show that the element release rates depend on a number of test parameters, including sample surface to solution volume ratio (m-1), interval (day), temperature (°C), and solution pH. This study provides a quantitative characterization of iodine release mechanism. The activation energy of iodine leaching 21±1.6 kJ/mol was obtained by varying the test temperature. At the test conditions of to neutral pH and 90 °C, the long-term iodine release rate 3.3 mg/(m2 • day) is projected by normalizing sample surface area to solution volume ratio (S/V) to 1.0 m-1 and interval to 1 day. These findings demonstrate i) the feasibility of our approach to quantify the release mechanism and ii) the performance of iodine apatite as a favorable waste form candidate for I-129 disposal.

First-principles supercell calculations of small polarons with proper account for long-range polarization effects

NASA Astrophysics Data System (ADS)

Kokott, Sebastian; Levchenko, Sergey V.; Rinke, Patrick; Scheffler, Matthias

2018-03-01

We present a density functional theory (DFT) based supercell approach for modeling small polarons with proper account for the long-range elastic response of the material. Our analysis of the supercell dependence of the polaron properties (e.g., atomic structure, binding energy, and the polaron level) reveals long-range electrostatic effects and the electron–phonon (el–ph) interaction as the two main contributors. We develop a correction scheme for DFT polaron calculations that significantly reduces the dependence of polaron properties on the DFT exchange-correlation functional and the size of the supercell in the limit of strong el–ph coupling. Using our correction approach, we present accurate all-electron full-potential DFT results for small polarons in rocksalt MgO and rutile TiO2.

Utility of respiratory ward-based NIV in acidotic hypercapnic respiratory failure.

PubMed

Dave, Chirag; Turner, Alice; Thomas, Ajit; Beauchamp, Ben; Chakraborty, Biman; Ali, Asad; Mukherjee, Rahul; Banerjee, Dev

2014-11-01

We sought to elicit predictors of in-hospital mortality for first and subsequent admissions with acidotic hypercapnic respiratory failure (AHRF) in a cohort of chronic obstructive pulmonary disease patients who have undergone ward-based non-invasive ventilation (NIV), and identify features associated with long-term survival. Analysis of prospectively collected data at a single centre on patients undergoing NIV for AHRF between 2004 and 2009. Predictors of in-hospital mortality and intubation were sought by logistic regression and predictors of long-term survival by Cox regression. Initial pH exhibited a threshold effect for in-hospital mortality at pH 7.15. This relationship remained in patients undergoing their first episode of AHRF. In both first and subsequent admissions, a pH threshold of 7.25 at 4 h was associated with better prognosis (P = 0.02 and P = 0.04 respectively). In second or subsequent episodes of AHRF, mortality was lower and predicted only by age (P = 0.002) on multivariate analysis. NIV could be used on medical wards for patients with pH 7.16 or greater on their first admission, although more conservative values should continue to be used for those with a second or subsequent episodes of AHRF. © 2014 Asian Pacific Society of Respirology.

In situ spectrophotometric measurement of dissolved inorganic carbon in seawater.

PubMed

Liu, Xuewu; Byrne, Robert H; Adornato, Lori; Yates, Kimberly K; Kaltenbacher, Eric; Ding, Xiaoling; Yang, Bo

2013-10-01

Autonomous in situ sensors are needed to document the effects of today's rapid ocean uptake of atmospheric carbon dioxide (e.g., ocean acidification). General environmental conditions (e.g., biofouling, turbidity) and carbon-specific conditions (e.g., wide diel variations) present significant challenges to acquiring long-term measurements of dissolved inorganic carbon (DIC) with satisfactory accuracy and resolution. SEAS-DIC is a new in situ instrument designed to provide calibrated, high-frequency, long-term measurements of DIC in marine and fresh waters. Sample water is first acidified to convert all DIC to carbon dioxide (CO2). The sample and a known reagent solution are then equilibrated across a gas-permeable membrane. Spectrophotometric measurement of reagent pH can thereby determine the sample DIC over a wide dynamic range, with inherent calibration provided by the pH indicator's molecular characteristics. Field trials indicate that SEAS-DIC performs well in biofouling and turbid waters, with a DIC accuracy and precision of ∼2 μmol kg(-1) and a measurement rate of approximately once per minute. The acidic reagent protects the sensor cell from biofouling, and the gas-permeable membrane excludes particulates from the optical path. This instrument, the first spectrophotometric system capable of automated in situ DIC measurements, positions DIC to become a key parameter for in situ CO2-system characterizations.

Microstructural evolution in a 17-4 PH stainless steel after aging at 400 C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murayama, M.; Hono, K.; Katayama, Y.

1999-02-01

The microstructure of 17-4 PH stainless steel at various stages of heat treatment, i.e., after solution heat treatment, tempering at 580 C, and long-term aging at 400 C, have been studied by atom probe field ion microscopy (APFIM) and transmission electron microscopy (TEM). The solution-treated specimen consists largely of martensite with a small fraction of {delta}-ferrite. No precipitates are present in the martensite phase, while spherical fcc-Cu particles are present in the {delta}-ferrite. No precipitates are present in the martensite phase, while spherical fcc-Cu particles are present in the {delta}-ferrite. After tempering for 4 hours as 580 C, coherent Cumore » particles precipitate in the martensite phase. At this stage, the Cr concentration in the martensite phase is still uniform. After 5000 hours aging at 400 C, the martensite spinodaly decomposes into Fe-rich {alpha} and Cr-enriched {alpha}{prime}. In addition, fine particles of the G-phase (structure type D8{sub a}, space group Fm{bar 3}m) enriched in Si, Ni, and Mn have been found in intimate contact with the Cu precipitates. Following spinodal decomposition of the martensite phase, G-phase precipitation occurs after long-term aging.« less

Ammonia oxidizers and nitrite-oxidizing bacteria respond differently to long-term manure application in four paddy soils of south of China.

PubMed

Liu, Haiyang; Li, Jia; Zhao, Yan; Xie, Kexin; Tang, Xianjin; Wang, Shaoxian; Li, Zhongpei; Liao, Yulin; Xu, Jianming; Di, Hongjie; Li, Yong

2018-08-15

Nitrification plays an important role in the soil nitrogen (N) cycle, and fertilizer application may influence soil nitrifiers' abundance and composition. However, the effect of long-term manure application in paddy soils on nitrifying populations is poorly understood. We chose four long-term manure experimental fields in the south of China to study how the abundance and community structure of nitrifiers would change in response to long-term manure application using quantitative PCR and Miseq sequencing analyses. Our results showed that manure application significantly increased ammonia oxidizing archaea (AOA) abundance at the ChangSha (CS) and NanChang (NC) sites, while the abundance of ammonia oxidizing bacteria (AOB) represented 4.8- and 12.8- fold increases at the JiaXing (JX) and YingTan (YT) sites, respectively. Miseq sequencing of 16S rRNA genes indicated that manure application altered the community structure of nitrifying populations, especially at the NC and YT sites. The application of manure significantly changed AOA and nitrite oxidizing bacteria (NOB) community structures but not those of AOB, suggesting that AOA and NOB may be more sensitive to manures. Variation partitioning analysis (VPA) and redundancy analysis (RDA) indicated that soil pH, TN, NO 3 - -N and water content were the main factors in shaping nitrifying communities. These findings suggest that nitrifiers respond diversely to manure application, and soil physiochemical properties play an important role in determining nitrifiers' abundance and communities with long-term manure addition. Copyright © 2018 Elsevier B.V. All rights reserved.

Anoxic Biodegradation of Isosaccharinic Acids at Alkaline pH by Natural Microbial Communities.

PubMed

Rout, Simon P; Charles, Christopher J; Doulgeris, Charalampos; McCarthy, Alan J; Rooks, Dave J; Loughnane, J Paul; Laws, Andrew P; Humphreys, Paul N

2015-01-01

One design concept for the long-term management of the UK's intermediate level radioactive wastes (ILW) is disposal to a cementitious geological disposal facility (GDF). Under the alkaline (10.013.0) anoxic conditions expected within a GDF, cellulosic wastes will undergo chemical hydrolysis. The resulting cellulose degradation products (CDP) are dominated by α- and β-isosaccharinic acids (ISA), which present an organic carbon source that may enable subsequent microbial colonisation of a GDF. Microcosms established from neutral, near-surface sediments demonstrated complete ISA degradation under methanogenic conditions up to pH 10.0. Degradation decreased as pH increased, with β-ISA fermentation more heavily influenced than α-ISA. This reduction in degradation rate was accompanied by a shift in microbial population away from organisms related to Clostridium sporosphaeroides to a more diverse Clostridial community. The increase in pH to 10.0 saw an increase in detection of Alcaligenes aquatilis and a dominance of hydrogenotrophic methanogens within the Archaeal population. Methane was generated up to pH 10.0 with acetate accumulation at higher pH values reflecting a reduced detection of acetoclastic methanogens. An increase in pH to 11.0 resulted in the accumulation of ISA, the absence of methanogenesis and the loss of biomass from the system. This study is the first to demonstrate methanogenesis from ISA by near surface microbial communities not previously exposed to these compounds up to and including pH 10.0.

Use of a biparticle fluidized-bed bioreactor for the continuous and simultaneous fermentation and purification of lactic acid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaufman, E. N.; Cooper, S. P.; Clement, S. L.

A continuous biparticle fluidized bed reactor is developed for the simultaneous fermentation and purification of lactic acid. In this processing scheme, bacteria are immobilized in gelatin beads and are fluidized in a columnar reactor. Solid particles with sorbent capacity for the product are introduced at the top of the reactor, and fall counter currently to the biocatalyst, effecting in situ removal of the inhibitory product, while also controlling reactor pH at optimal levels. Initial long-term fermentation trials using immobilized Lactobacillus delbreuckii have demonstrated a 12 fold increase in volumetric productivity during adsorbent addition as opposed to control fermentations in themore » same reactor. Unoptimized regeneration of the loaded sorbent has effected at least an 8 fold concentration of lactic acid, and a 68 fold enhancement in separation from glucose compared to original levels in the fermentation broth. The benefits of this reactor system as opposed to conventional batch fermentation are discussed in terms of productivity and process economics.« less

Use of a biparticle fluidized-bed bioreactor for the continuous and simultaneous fermentation and purification of lactic acid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaufman, E.N.; Cooper, S.P.; Clement, S.L.

1995-12-31

A continuous biparticle fluidized-bed reactor is developed for the simultaneous fermentation and purification of lactic acid. In this processing scheme, bacteria are immobilized in gelatin beads and are fluidized in a columnar reactor. Solid particles with sorbent capacity for the product are introduced at the top of the reactor, and fall counter currently to the biocatalyst, effecting in situ removal of the inhibitory product, while also controlling reactor pH at optimal levels. Initial long-term fermentation trials using immobilized Lactobacillus delbreuckii have demonstrated a 12-fold increase in volumetric productivity during absorbent addition as opposed to control fermentations in the same reactor.more » Unoptimized regeneration of the loaded sorbent has effected at least an eightfold concentration of lactic acid and a 68-fold enhancement in separation from glucose compared to original levels in the fermentation broth. The benefits of this reactor system as opposed to conventional batch fermentation are discussed in terms of productivity and process economics.« less

Long-term competition between sulfate reducing and methanogenic bacteria in UASB reactors treating volatile fatty acids.

PubMed

Omil, F; Lens, P; Visser, A; Hulshoff Pol, L W; Lettinga, G

1998-03-20

The competition between acetate utilizing methane-producing bacteria (MB) and sulfate-reducing bacteria (SRB) was studied in mesophilic (30 degrees C) upflow anaerobic sludge bed (UASB) reactors (upward velocity 1 m h-1; pH 8) treating volatile fatty acids and sulfate. The UASB reactors treated a VFA mixture (with an acetate:propionate:butyrate ratio of 5:3:2 on COD basis) or acetate as the sole substrate at different COD:sulfate ratios. The outcome of the competition was evaluated in terms of conversion rates and specific methanogenic and sulfidogenic activities. The COD:sulfate ratio was a key factor in the partitioning of acetate utilization between MB and SRB. In excess of sulfate (COD:sulfate ratio lower than 0.67), SRB became predominant over MB after prolonged reactor operation: 250 and 400 days were required to increase the amount of acetate used by SRB from 50 to 90% in the reactor treating, respectively, the VFA mixture or acetate as the sole substrate. The competition for acetate was further studied by dynamic simulations using a mathematical model based on the Monod kinetic parameters of acetate utilizing SRB and MB. The simulations confirmed the long term nature of the competition between these acetotrophs. A high reactor pH (+/-8), a short solid retention time (<150 days), and the presence of a substantial SRB population in the inoculum may considerably reduce the time required for acetate-utilising SRB to outcompete MB. Copyright 1998 John Wiley & Sons, Inc.

Preparation of a Natural Product Extract Library for Investigation Against Disease States Specific to Defence Health: A Mini Long Range Research Project

DTIC Science & Technology

2009-02-01

Sci in 1994 and with a BSc(Hons) in 1995 from The University of Melbourne. In 1999 he completed a PhD in marine natural products chemistry from the...BSc(Hons) in 1994 from the University of Melbourne. In 1998 she completed a PhD in organic chemistry , developing new free-radical syntheses of some...Melissa began work in the area of medicinal chemistry , developing partial agonists of adenosine A1 receptors; firstly at Deakin University and

Transcriptomic responses to seawater acidification among sea urchin populations inhabiting a natural pH mosaic.

PubMed

Evans, Tyler G; Pespeni, Melissa H; Hofmann, Gretchen E; Palumbi, Stephen R; Sanford, Eric

2017-04-01

Increasing awareness of spatial and temporal variation in ocean pH suggests some marine populations may be adapted to local pH regimes and will therefore respond differently to present-day pH variation and to long-term ocean acidification. In the Northeast Pacific Ocean, differences in the strength of coastal upwelling cause latitudinal variation in prevailing pH regimes that are hypothesized to promote local adaptation and unequal pH tolerance among resident populations. In this study, responses to experimental seawater acidification were compared among embryos and larvae from six populations of purple sea urchins (Strongylocentrotus purpuratus) inhabiting areas that differ in their frequency of low pH exposure and that prior research suggests are locally adapted to seawater pH. Transcriptomic analyses demonstrate urchin populations most frequently exposed to low pH seawater responded to experimental acidification by expressing genes within major ATP-producing pathways at greater levels than populations encountering low pH less often. Multiple genes within the tricarboxylic acid cycle, electron transport chain and fatty acid beta oxidation pathways were upregulated in urchin populations experiencing low pH conditions most frequently. These same metabolic pathways were significantly over-represented among genes both expressed in a population-specific manner and putatively under selection to enhance low pH tolerance. Collectively, these data suggest natural selection is acting on metabolic gene networks to redirect ATP toward maintaining acid-base homeostasis and enhance tolerance of seawater acidification. As a trade-off, marine populations more tolerant of low pH may have less energy to put towards other aspects of fitness and to respond to additional ocean change. © 2017 John Wiley & Sons Ltd.

Prognostic severity scores for patients with COPD exacerbations attending emergency departments.

PubMed

Quintana, J M; Esteban, C; Unzurrunzaga, A; Garcia-Gutierrez, S; Gonzalez, N; Lafuente, I; Bare, M; de Larrea, N Fernandez; Vidal, S

2014-12-01

Reported predictors of the adverse evolution of patients with chronic obstructive pulmonary disease exacerbations (eCOPD) are various and inconsistent in the bibliography. To develop clinical prediction rules for short-term outcomes in eCOPD patients attending an emergency department (ED). Prospective cohort study of patients with an eCOPD. Short-term outcomes were admission to an intensive care unit (ICU), admission to an intermediate respiratory care unit (IRCU) and death in these groups. Multivariate logistic regression models were developed for each of the outcomes. Predictors of ICU or IRCU admission were use of long-term home oxygen therapy (LT-HOT) or non-invasive mechanical ventilation (NIMV), elevated PCO2 and decreased pH upon ED arrival (area under the curve [AUC] 0.87 in the derivation sample; 0.89 in the validation sample). Among those admitted to an ICU or IRCU, predictors of death were increased age, use at home of LT-HOT or NIMV, use of inspiratory accessory muscles upon ED arrival and altered Glasgow Coma Scale (<15 points) (AUC 0.78). Three clinical predictors available in the ED can be used to create a simple score to predict the need for intensive treatment among eCOPD patients. Such a score can be a tool for clinical practice.

Methane production and consumption in grassland and boreal ecosystems

NASA Technical Reports Server (NTRS)

Schimel, David S.; Burke, Ingrid C.; Johnston, Carol; Pastor, John

1994-01-01

The objectives of the this project were to develop a mechanistic understanding of methane production and oxidation suitable for incorporation into spatially explicit models for spatial extrapolation. Field studies were undertaken in Minnesota, Canada, and Colorado to explore the process controls over the two microbial mediated methane transformations in a range of environments. Field measurements were done in conjunction with ongoing studies in Canada (the Canadian Northern Wetlands Projects: NOWES) and in Colorado (The Shortgrass Steppe Long Term Ecological Research Project: LTER). One of the central hypotheses of the proposal was that methane production should be substrate limited, as well as being controlled by physical variables influencing microbial activity (temperature, oxidation status, and pH). Laboratory studies of peats from Canada and Minnesota (Northern and Southern Boreal) were conducted with amendments of a methanogenic substrate at multiple temperatures and at multiple pHs (the latter by titrating samples). The studies showed control by substrate, pH, and temperature in order in anaerobic samples. Field and laboratory manipulations of natural plant litter, rather than an acetogenic substrate, showed similarly large effects. The studies concluded that substrate is an important control over methanogenesis, that substrate availability in the field is closely coupled to the chemistry of the dominant vegetation influencing its decomposition rate, that most methane is produced from recent plant litter, and that landscape changes in pH are an important control, highly correlated with vegetation.

Very long baseline interferometry applied to polar motion, relativity, and geodesy. Ph. D. thesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, C.

1978-01-01

The causes and effects of diurnal polar motion are described. An algorithm was developed for modeling the effects on very long baseline interferometry observables. A selection was made between two three-station networks for monitoring polar motion. The effects of scheduling and the number of sources observed on estimated baseline errors are discussed. New hardware and software techniques in very long baseline interferometry are described.

Long-Term Patterns in C-Q Relations in an Adirondack Stream Reveal Decreasing Severity of Episodic Acidification

NASA Astrophysics Data System (ADS)

Burns, D. A.; Lawrence, G. B.; Driscoll, C. T.; Sullivan, T. J.; Shao, S.; McDonnell, T. C.

2017-12-01

Episodic acidification occurs when surface water pH and ANC decrease temporarily during rain events and snowmelt. The principal drivers of episodic acidification are increases in sulfuric acid, nitric acid, organic acids, and dilution of base cations. In regions where surface waters are sensitive to acid deposition, ANC values may approach or decline below 0 µeq/L during high flows, which may result in deleterious effects to sensitive aquatic biota. The Adirondack Mountains of New York have abundant streams and lakes, many of which are highly sensitive to the effects of acid deposition. Long-term monitoring data indicate that pH and ANC in regional surface waters are increasing in response to decreases in the acidity of atmospheric deposition that result from decreasing SO2 and NOx emissions as the Clean Air Act and its ancillary rules and amendments have been implemented. Most surface-water monitoring focuses on low-flow and broad seasonal patterns, and less is known about how episodic acidification has responded to emissions decreases. Here, we report on spatial and temporal patterns in episodic acidification through analysis of C-Q relations from surveys that target varying flow conditions as well as data from a few long-term intensively sampled stream monitoring sites. Each stream sample was assigned a Q percentile value based on a resident or nearby gage, and a statistical relation between ANC values and Q percentile was developed. The magnitude of episodic decreases in ANC increases as low-flow ANC increases, a pattern that likely results from an increasing influence of dilution, especially evident when low-flow ANC values exceed 100 µeq/L. Chronically acidic streams with low-flow ANC near 0 µeq/L show little episodic acidification, whereas streams with low-flow ANC values of about 50 µeq/L generally show ANC decreases to less than 0 µeq/L at high flow. Preliminary analysis of a 24-yr data set (1991-2014) at Buck Creek indicates that increases in high-flow ANC are more than twice those of low-flow ANC. These ANC values generally no longer decline below 0 µeq/L at the highest flows, which typically occur during spring snowmelt. Further analyses will explore how the drivers of episodic acidification vary across the region with low-flow ANC and whether clear trends in these drivers are evident across the region.

Long-term care for people with developmental disabilities: a critical analysis.

PubMed

Palley, H A; Van Hollen, V

2000-08-01

This article explores how the trends toward long-term community care affecting people with developmental disabilities developed. Appropriateness of care and quality of life issues are discussed. The article also reviews the development of long-term care for frail and disabled elderly people and explores the arguments for a continuum of care that have developed in this area. The authors conclude that future policies with respect to meeting long-term care needs for people with developmental disabilities must be addressed flexibly on an individual basis, related to individual needs, and must provide a continuum of care services.

Interdependence of right ventricular systolic function and left ventricular filling and its association with outcome for patients with pulmonary hypertension.

PubMed

Motoji, Yoshiki; Tanaka, Hidekazu; Fukuda, Yuko; Sano, Hiroyuki; Ryo, Keiko; Imanishi, Junichi; Miyoshi, Tatsuya; Sawa, Takuma; Mochizuki, Yasuhide; Matsumoto, Kensuke; Emoto, Noriaki; Hirata, Ken-ichi

2015-04-01

Although impaired right ventricular (RV) performance has been associated with adverse outcomes for pulmonary hypertension (PH) patients, the relationship between bi-ventricular interdependence and outcomes is not yet fully understood. We studied 96 PH patients. RV systolic function was assessed by means of RV free-wall longitudinal speckle-tracking strain (RV-free), and left ventricular (LV) filling as early diastolic transmitral flow velocity (TMF-E). RV-free ≤19 % and TMF-E <60 cm/s were adopted as pre-defined cut-offs for RV systolic dysfunction and LV under-filling, respectively, associated with worse outcomes. Long-term outcome was tracked over 2.2 years. RV-free correlated significantly with TMF-E (r = 0.57, p < 0.001).TMF-E and RV-free were significantly lower in patients with than in those without cardiac events. RV systolic dysfunction and LV under-filling was observed in 35 patients. These features were associated with worse long-term survival compared to other sub-groups (log-rank p = 0.012). A sequential Cox model based on clinical variables including world health organization functional class IV and brain natriuretic peptide >150 pg/dl (χ(2) = 1.2) was improved by the addition of RV-free (χ(2) = 5.5, p = 0.04) as well as of TMF-E (χ(2) = 11.5, p = 0.01). In conclusions, RV systolic function was shown to correlate significantly with LV filling in PH patients. In addition, not only assessment of RV systolic function, but also of a combined bi-ventricular parameter comprising RV systolic function and LV filling may well have clinical implications for more successful management of PH patients.

Reduced Salinity Improves Marine Food Availability With Positive Feedbacks on pH in a Tidally-Dominated Estuary

NASA Astrophysics Data System (ADS)

Lowe, A. T.; Roberts, E. A.; Galloway, A. W. E.

2016-02-01

Coastal regions around the world are changing rapidly, generating many physiological stressors for marine organisms. Food availability, a major factor determining physiological condition of marine organisms, in these systems reflects the influence of biological and environmental factors, and will likely respond dramatically to long-term changes. Using observations of phytoplankton, detritus, and their corresponding fatty acids and stable isotopes of carbon, nitrogen and sulfur, we identified environmental drivers of pelagic food availability and quality along a salinity gradient in a large tidally influenced estuary (San Juan Archipelago, Salish Sea, USA). Variation in chlorophyll a (Chl a), biomarkers and environmental conditions exhibited a similar range at both tidal and seasonal scales, highlighting a tide-related mechanism controlling productivity that is important to consider for long-term monitoring. Multiple parameters of food availability were inversely and non-linearly correlated to salinity, such that availability of high-quality (based on abundance, essential fatty acid concentration and C:N) seston increased below a salinity threshold of 30. The increased marine productivity was associated with increased pH and dissolved oxygen (DO) at lower salinity. Based on this observation we predicted that a decrease of salinity to below the threshold would result in higher Chl a, temperature, DO and pH across a range of temporal and spatial scales, and tested the prediction with a meta-analysis of available data. At all scales, these variables showed significant and consistent increases related to the salinity threshold. This finding provides important context to the increased frequency of below-threshold salinity over the last 71 years in this region, suggesting greater food availability with positive feedbacks on DO and pH. Together, these findings indicate that many of the environmental factors predicted to increase physiological stress to benthic suspension feeders (e.g. decreased salinity) may simultaneously and paradoxically improve conditions for benthic organisms.

Development of an underwater in-situ spectrophotometric sensor for seawater pH

NASA Astrophysics Data System (ADS)

Waterbury, Robert D.; Byrne, Robert H.; Kelly, John; Leader, Bram; McElligott, Sean; Russell, Randy

1996-12-01

A pH sensor based upon spectrophotometric techniques has been developed for in-situ analysis of surface seawater. This sensor utilizes a spectrophotometric pH indicator (Thymol Blue) which has been calibrated for use in seawater as a function of temperature and salinity. Shipboard spectrophotometric pH analyses routinely demonstrate a precision on the order of plus or minus 0.0004 pH units. In- situ analysis of seawater pH has demonstrated a precision on the order of plus or minus 0.001 and an accuracy, using shipboard measurements as a standard, on the order of plus or minus 0.01. The sensor is a self-contained system which pumps seawater, meters in indicator, spectrophotometrically determines indicator absorbance and stores data with a 1 Hz acquisition frequency. The sensor employs two absorbance cells, each with three wavelength channels, to obtain the spectrophotometric absorbance. The sensor system, rated for depths up to 500 m, provides pH, conductivity, temperature and can be operated via computer or in a standalone mode with internal data storage. The sensor utilizes less than 12 watts of power and is packaged in a 29' long by 4.5' diameter aluminum housing.

Ocean acidification and kelp development: Reduced pH has no negative effects on meiospore germination and gametophyte development of Macrocystis pyrifera and Undaria pinnatifida.

PubMed

Leal, Pablo P; Hurd, Catriona L; Fernández, Pamela A; Roleda, Michael Y

2017-06-01

The absorption of anthropogenic CO 2 by the oceans is causing a reduction in the pH of the surface waters termed ocean acidification (OA). This could have substantial effects on marine coastal environments where fleshy (non-calcareous) macroalgae are dominant primary producers and ecosystem engineers. Few OA studies have focused on the early life stages of large macroalgae such as kelps. This study evaluated the effects of seawater pH on the ontogenic development of meiospores of the native kelp Macrocystis pyrifera and the invasive kelp Undaria pinnatifida, in south-eastern New Zealand. Meiospores of both kelps were released into four seawater pH treatments (pH T 7.20, extreme OA predicted for 2300; pH T 7.65, OA predicted for 2100; pH T 8.01, ambient pH; and pH T 8.40, pre-industrial pH) and cultured for 15 d. Meiospore germination, germling growth rate, and gametophyte size and sex ratio were monitored and measured. Exposure to reduced pH T (7.20 and 7.65) had positive effects on germling growth rate and gametophyte size in both M. pyrifera and U. pinnatifida, whereas, higher pH T (8.01 and 8.40) reduced the gametophyte size in both kelps. Sex ratio of gametophytes of both kelps was biased toward females under all pH T treatments, except for U. pinnatifida at pH T 7.65. Germling growth rate under OA was significantly higher in M. pyrifera compared to U. pinnatifida but gametophyte development was equal for both kelps under all seawater pH T treatments, indicating that the microscopic stages of the native M. pyrifera and the invasive U. pinnatifida will respond similarly to OA. © 2017 Phycological Society of America.

Influence de l'alteration physique sur les caracteristiques physico-chimiques de monolithes de sols contamines traites par stabilisation/solidification au ciment

NASA Astrophysics Data System (ADS)

Remillard, Jonathan

The concern of contaminated sites is affecting millions of property owner worldwide. As they pose a risk to the environment, human health or impair the value of buildings, remediation of contaminated sites has become an everyday issue. Stabilization/solidification (S/S) of contaminated soils with cement is a remediation technology that was developed to confine contaminants that cannot be degraded biologically, chemically or thermally by other technologies. Soils treated with S/S form a monolith that can be valorized on site. However, this practice is fairly uncommon in Quebec and this reluctance is partly due to the risks of degradation of the monoliths and the lack of knowledge relative to the long-term behavior of altered monoliths. The objective of this project was to simulate these degradations on cement-based monoliths of contaminated soils treated with S/S technology by causing physical alterations using different cycles of freeze/thawing and drying/wetting, and then to study the impact of these alterations on the mass losses, compressive strength, hydraulic conductivity, pH and leachability of five trace metals (Cd, Cr, Cu, Pb and Zn) used as contaminants. Various processes of S/S have been studied, either cement contents of 15 and 20%, then the presence of 5% by weight of calcium carbonate. For each S/S process formulated, the freeze/thaw cycles were much more effective in physically altering the monoliths. These alterations were mainly reflected by lower compressive strength, even more with lower cement contents. For their part, the drying/wetting cycles rather created a chemical change that lowered the pH of the monoliths. These chemical changes also affected the interpretation of leaching test results, especially for copper and zinc, since it was difficult to attribute effects to either physical or chemical alterations. The results showed that only chromium leached more clearly in response to physical alterations. All other elements studied were little affected, even though some samples were highly altered. This demonstrates that in some cases, damages may have little impact on long-term performance of the monoliths in terms of contaminant immobilization. However, integrating the study of long-term behaviors of monoliths in a process of formulation for contaminated soil treatment with S/S can become paramount, as seen for chromium in this present study. Keywords: stabilization / solidification, deterioration, alteration, leachability, contaminants.

Advancing Minorities and Women to the PhD in Physics and Astronomy

NASA Astrophysics Data System (ADS)

Stassun, Keivan

2017-01-01

We briefly review the current status of underrepresented minorities in physics and astronomy: The underrepresentation of Black-, Hispanic-, and Native-Americans is an order of magnitude problem. We then describe the Fisk-Vanderbilt Masters-to-PhD Bridge program as a successful model for addressing this problem. Since 2004 the program has admitted 110 students, 90% of them underrepresented minorities (50% female), with a retention rate of 90%. The program has become the top producer of African American master's degrees in physics, and is now one of the top producers of minority PhDs in astronomy, materials science, and physics. We summarize the main features of the program including its core strategies: (1) replacing the GRE in admissions with indicators that are better predictive of long-term success, (2) partnering with a minority-serving institution for student training through collaborative research, and (3) using the master's degree as a deliberate stepping stone to the PhD. We show how misuse of the GRE in graduate admissions may by itself in large part explain the ongoing underrepresentation of minorities in PhD programs, and we describe our alternate methods to identify talented individuals most likely to succeed. We describe our mentoring model and toolkit which may be utilized to enhance the success of all PhD students.

Impact of long-term salinity exposure in anaerobic membrane bioreactors treating phenolic wastewater: Performance robustness and endured microbial community.

PubMed

Muñoz Sierra, Julian D; Oosterkamp, Margreet J; Wang, Wei; Spanjers, Henri; van Lier, Jules B

2018-05-07

Industrial wastewaters are becoming increasingly associated with extreme conditions such as the presence of refractory compounds and high salinity that adversely affect biomass retention or reduce biological activity. Hence, this study evaluated the impact of long-term salinity increase to 20 gNa + .L -1 on the bioconversion performance and microbial community composition in anaerobic membrane bioreactors treating phenolic wastewater. Phenol removal efficiency of up to 99.9% was achieved at 14 gNa + .L -1 . Phenol conversion rates of 5.1 mgPh.gVSS -1 .d -1 , 4.7 mgPh.gVSS -1 .d -1 , and 11.7 mgPh.gVSS -1 .d -1 were obtained at 16 gNa + .L -1 ,18 gNa + .L -1 and 20 gNa + .L -1 , respectively. The AnMBR's performance was not affected by short-term step-wise salinity fluctuations of 2 gNa + .L -1 in the last phase of the experiment. It was also demonstrated in batch tests that the COD removal and methane production rate were higher at a K + :Na + ratio of 0.05, indicating the importance of potassium to maintain the methanogenic activity. The salinity increase adversely affected the transmembrane pressure likely due to a particle size decrease from 185 μm at 14 gNa + .L -1 to 16 μm at 20 gNa + .L -1 . Microbial community was dominated by bacteria belonging to the Clostridium genus and archaea by Methanobacterium and Methanosaeta genus. Syntrophic phenol degraders, such as Pelotomaculum genus were found to be increased when the maximum phenol conversion rate was attained at 20 gNa + .L -1 . Overall, the observed robustness of the AnMBR performance indicated an endured microbial community to salinity changes in the range of the sodium concentrations applied. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Highly-active oxygen evolution electrocatalyzed by an Fe-doped NiCr2O4 nanoparticle film.

PubMed

Zhao, Jinxiu; Li, Xianghong; Cui, Guanwei; Sun, Xuping

2018-05-11

Alkaline water splitting offers a simple method for the mass production of hydrogen but suffers from the sluggish kinetics of the anodic oxygen evolution reaction (OER). Here, we report on the development of an Fe-doped NiCr2O4 nanoparticle film on Ni foam (Fe-NiCr2O4/NF) as a non-noble-metal OER electrocatalyst with superior catalytic activity at alkaline pH. Such Fe-NiCr2O4/NF demands overpotentials as low as 228 and 318 mV to drive current densities of 20 and 500 mA cm-2, respectively, in 1.0 M KOH. Notably, it also shows strong long-term electrochemical durability with its activity being retained for at least 60 h.

Biogeochemical-Argo: achievements, challenges for the future and potential synergies with other components of ocean observation systems

NASA Astrophysics Data System (ADS)

Claustre, Hervé; Johnson, Ken

2017-04-01

The recently launched Biogeochemical-Argo (BGC-Argo) program aims at developing a global network of biogeochemical sensors on Argo profiling floats for acquiring long-term high-quality time-series of oceanic properties. BGC-Argo is in particular poised to address a number of challenges in ocean science (e.g. hypoxia, carbon uptake, ocean acidification, biological-carbon pump and phytoplankton communities), topics that are difficult, if not impossible, to address with our present observing assets. Presently six variables are considered as core BGC-Argo variables (O2, NO3, pH, Chla, suspended particles and downwelling irradiance). Historically, BGC-Argo has been initiated through small-scale "showcase" projects progressively scaling up into regional case studies essentially addressing key biological pump-related questions in specific regions (e.g. sub-tropical gyres, North Atlantic, Southern Ocean). Now BGC-Argo is transitioning towards a global and sustained observation system thanks to progressive international coordination of national contributions and to increasingly mature and efficient data management and distribution systems. In this presentation, we will highlight a variety of results derived from BGC-Argo observations and encompassing a wide range of topics related to ocean biogeochemistry. Challenges for the future and long-term sustainability of the system will be addressed in particular with respect to maintaining a high-quality and interoperable dataset over long-term. Part of this can be achieved through a tight interaction with programs (e.g. GOSHIP) and their historical databases, which should constitute a corner stone to assess data quality. Example on the interplay between BGC-Argo and GlodapV2 databases will be particularly exemplified in this context. Furthermore, we will illustrate the potential synergies between synoptically measured surface satellite-quantities and their vertically resolved (BGC-Argo) counterparts into the development of 3D biogeochemical products.

The discovery of long-term potentiation.

PubMed

Lømo, Terje

2003-04-29

This paper describes circumstances around the discovery of long-term potentiation (LTP). In 1966, I had just begun independent work for the degree of Dr medicinae (PhD) in Per Andersen's laboratory in Oslo after an eighteen-month apprenticeship with him. Studying the effects of activating the perforant path to dentate granule cells in the hippocampus of anaesthetized rabbits, I observed that brief trains of stimuli resulted in increased efficiency of transmission at the perforant path-granule cell synapses that could last for hours. In 1968, Tim Bliss came to Per Andersen's laboratory to learn about the hippocampus and field potential recording for studies of possible memory mechanisms. The two of us then followed up my preliminary results from 1966 and did the experiments that resulted in a paper that is now properly considered to be the basic reference for the discovery of LTP.

Severe tissue damage in Atlantic cod larvae under increasing ocean acidification

NASA Astrophysics Data System (ADS)

Frommel, Andrea Y.; Maneja, Rommel; Lowe, David; Malzahn, Arne M.; Geffen, Audrey J.; Folkvord, Arild; Piatkowski, Uwe; Reusch, Thorsten B. H.; Clemmesen, Catriona

2012-01-01

Ocean acidification, caused by increasing atmospheric concentrations of CO2 (refs , , ), is one of the most critical anthropogenicthreats to marine life. Changes in seawater carbonate chemistry have the potential to disturb calcification, acid-base regulation, blood circulation and respiration, as well as the nervous system of marine organisms, leading to long-term effects such as reduced growth rates and reproduction. In teleost fishes, early life-history stages are particularly vulnerable as they lack specialized internal pH regulatory mechanisms. So far, impacts of relevant CO2 concentrations on larval fish have been found in behaviour and otolith size, mainly in tropical, non-commercial species. Here we show detrimental effects of ocean acidification on the development of a mass-spawning fish species of high commercial importance. We reared Atlantic cod larvae at three levels of CO2, (1) present day, (2) end of next century and (3) an extreme, coastal upwelling scenario, in a long-term ( months) mesocosm experiment. Exposure to CO2 resulted in severe to lethal tissue damage in many internal organs, with the degree of damage increasing with CO2 concentration. As larval survival is the bottleneck to recruitment, ocean acidification has the potential to act as an additional source of natural mortality, affecting populations of already exploited fish stocks.

Methylation-reprogrammed Wnt/β-catenin signalling mediated prenatal hypoxia-induced brain injury in foetal and offspring rats.

PubMed

Zhang, Yingying; Zhang, Mengshu; Li, Lingjun; Wei, Bin; He, Axin; Lu, Likui; Li, Xiang; Zhang, Lubo; Xu, Zhice; Sun, Miao

2018-05-28

Prenatal hypoxia (PH) is a common pregnancy complication, harmful to brain development. This study investigated whether and how PH affected Wnt pathway in the brain. Pregnant rats were exposed to hypoxia (10.5% O 2 ) or normoxia (21% O 2 ; Control). Foetal brain weight and body weight were decreased in the PH group, the ratio of brain weight to body weight was increased significantly. Prenatal hypoxia increased mRNA expression of Wnt3a, Wnt7a, Wnt7b and Fzd4, but not Lrp6. Activated β-catenin protein and Fosl1 expression were also significantly up-regulated. Increased Hif1a expression was found in the PH group associated with the higher Wnt signalling. Among 5 members of the Sfrp family, Sfrp4 was down-regulated. In the methylation-regulating genes, higher mRNA expressions of Dnmt1 and Dnmt3b were found in the PH group. Sodium bisulphite and sequencing revealed hyper-methylation in the promoter region of Sfrp4 gene in the foetal brain, accounting for its decreased expression and contributing to the activation of the Wnt-Catenin signalling. The study of PC12 cells treated with 5-aza further approved that decreased methylation could result in the higher Sfrp4 expression. In the offspring hippocampus, protein levels of Hif1a and mRNA expression of Sfrp4 were unchanged, whereas Wnt signal pathway was inhibited. The data demonstrated that PH activated the Wnt pathway in the foetal brain, related to the hyper-methylation of Sfrp4 as well as Hif1a signalling. Activated Wnt signalling might play acute protective roles to the foetal brain in response to hypoxia, also would result in disadvantageous influence on the offspring in long-term. © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Human Immunodeficiency Virus nef signature sequences are associated with pulmonary hypertension.

PubMed

Almodovar, Sharilyn; Knight, Rob; Allshouse, Amanda A; Roemer, Sarah; Lozupone, Catherine; McDonald, Daniel; Widmann, Jeremy; Voelkel, Norbert F; Shelton, Robert J; Suarez, Edu B; Hammer, Kenneth W; Goujard, Cecile; Petrosillo, Nicola; Simonneau, Gerald; Hsue, Priscilla Y; Humbert, Marc; Flores, Sonia C

2012-06-01

Severe pulmonary hypertension (PH) associated with vascular remodeling is a long-term complication of HIV infection (HIV-PH) affecting 1/200 infected individuals vs. 1/200,000 frequency in the uninfected population. Factors accounting for increased PH susceptibility in HIV-infected individuals are unknown. Rhesus macaques infected with chimeric SHIVnef virions but not with SIV display PH-like pulmonary vascular remodeling suggesting that HIV-Nef is associated with PH; these monkeys showed changes in nef sequences that correlated with pathogenesis after passage in vivo. We further examined whether HIV-nef alleles in HIV-PH subjects have signature sequences associated with the disease phenotype. We evaluated specimens from participants with and without HIV-PH from European Registries and validated results with samples collected as part of the Lung-HIV Studies in San Francisco. We found that 10 polymorphisms in nef were overrepresented in blood cells or lung tissue specimens from European HIV-PH individuals but significantly less frequent in HIV-infected individuals without PH. These polymorphisms mapped to known functional domains in Nef. In the validation cohort, 7/10 polymorphisms in the HIV-nef gene were confirmed; these polymorphisms arose independently from viral load, CD4(+) T cell counts, length of infection, and antiretroviral therapy status. Two out of 10 polymorphisms were previously reported in macaques with PH-like pulmonary vascular remodeling. Cloned recombinant Nef proteins from clinical samples down-regulated CD4, suggesting that these primary isolates are functional. This study offers new insights into the association between Nef polymorphisms in functional domains and the HIV-PH phenotype. The utility of these polymorphisms as predictors of PH should be examined in a larger population.

Bulk Dissolution Rates of Cadmium and Bismuth Tellurides As a Function of pH, Temperature and Dissolved Oxygen.

PubMed

Biver, Marc; Filella, Montserrat

2016-05-03

The toxicity of Cd being well established and that of Te suspected, the bulk, surface-normalized steady-state dissolution rates of two industrially important binary tellurides-polycrystalline cadmium and bismuth tellurides- were studied over the pH range 3-11, at various temperatures (25-70 °C) and dissolved oxygen concentrations (0-100% O2 in the gas phase). The behavior of both tellurides is strikingly different. The dissolution rates of CdTe monotonically decreased with increasing pH, the trend becoming more pronounced with increasing temperature. Activation energies were of the order of magnitude associated with surface controlled processes; they decreased with decreasing acidity. At pH 7, the CdTe dissolution rate increased linearly with dissolved oxygen. In anoxic solution, CdTe dissolved at a finite rate. In contrast, the dissolution rate of Bi2Te3 passed through a minimum at pH 5.3. The activation energy had a maximum in the rate minimum at pH 5.3 and fell below the threshold for diffusion control at pH 11. No oxygen dependence was detected. Bi2Te3 dissolves much more slowly than CdTe; from one to more than 3.5 orders of magnitude in the Bi2Te3 rate minimum. Both will readily dissolve under long-term landfill deposition conditions but comparatively slowly.

The effect of pH dependence of antibody-antigen interactions on subcellular trafficking dynamics.

PubMed

Devanaboyina, Siva Charan; Lynch, Sandra M; Ober, Raimund J; Ram, Sripad; Kim, Dongyoung; Puig-Canto, Alberto; Breen, Shannon; Kasturirangan, Srinath; Fowler, Susan; Peng, Li; Zhong, Haihong; Jermutus, Lutz; Wu, Herren; Webster, Carl; Ward, E Sally; Gao, Changshou

2013-01-01

A drawback of targeting soluble antigens such as cytokines or toxins with long-lived antibodies is that such antibodies can prolong the half-life of the target antigen by a "buffering" effect. This has motivated the design of antibodies that bind to target with higher affinity at near neutral pH relative to acidic endosomal pH (~pH 6.0). Such antibodies are expected to release antigen within endosomes following uptake into cells, whereas antibody will be recycled and exocytosed in FcRn-expressing cells. To understand how the pH dependence of antibody-antigen interactions affects intracellular trafficking, we generated three antibodies that bind IL-6 with different pH dependencies in the range pH 6.0-7.4. The behavior of antigen in the presence of these antibodies has been characterized using a combination of fixed and live cell fluorescence microscopy. As the affinity of the antibody:IL-6 interaction at pH 6.0 decreases, an increasing amount of antigen dissociates from FcRn-bound antibody in early and late endosomes, and then enters lysosomes. Segregation of antibody and FcRn from endosomes in tubulovesicular transport carriers (TCs) into the recycling pathway can also be observed in live cells, and the extent of IL-6 association with TCs correlates with increasing affinity of the antibody:IL-6 interaction at acidic pH. These analyses result in an understanding, in spatiotemporal terms, of the effect of pH dependence of antibody-antigen interactions on subcellular trafficking and inform the design of antibodies with optimized binding properties for antigen elimination.

Air-Pollution-Mediated Changes in Alpine Ecosystems and Ecotones.

PubMed

Rusek, Josef

1993-08-01

Soil biological parameters (e.g., Collembola), soil types, soil chemical parameters (pH, humus substances), and plant communities were studied in different ecosystems and ecotones in alpine, subalpine, and spruce forest zones in the Tatra National Park, Slovak Republic. The preliminary, selected data, based on a long-term research program, showed a high sensitivity of some alpine ecotones and ecosystems to long-distance transported acid deposits. The changes in different ecosystem parameters since 1977 were more extensive in alpine grasslands on limestone than on granite. The greatest soil pH decrease was in the plant communities Festucetum versicoloris (-1.5 pH), Geranio-Alchemilletum crinitae (-1.32 pH), and Saxifragetum perdurantis (-1.25 pH), which are restricted to places with snow accumulation and water runoff gullies. In these ecosystems the greatest changes occurred in the leaching of humus substances. Some formerly less abundant and rare soil animals restricted to acid bedrock became dominant in some ecosystems on limestone as well as on granite; other formerly dominant species disappeared from the entire study area (e.g., Folsomia alpina). The aerial extent of some ecosystems changed substantially since 1977, and their surrounding ecotones moved into the space formerly occupied by one of the adjacent ecosystems. These changes are detectable by remote-sensing methods. In Central European mountains, strongly affected by global and regional industrial air pollution (e.g., Krusne Hory, Krkonose, Beskydy), spruce forests started to die back from higher to lower mountain elevations. The effects of air pollution on alpine and subalpine vegetation were not studied there. Strong alterations in alpine ecosystems and ecotones were detected by the author during long-term studies in the High Tatra Mountains, and I suggest that subalpine and mountain forest belts will be affected here in the near future as they were in the more polluted Central European mountains. The ecosystems and ecotones in higher alpine zones are likely to be affected earlier than the ecosystems at lower altitudes. Detection of ecosystem alteration in the alpine zone may be used for prediction of acidification processes and global change in ecosystems at lower altitudes. The consequences of global climate change are predictable by monitoring changes in the extent of some ecosystems located in discrete mountain geomorphological units (e.g., karstic sinkholes, water runoff gullies, wind shadows, ridges exposed to wind, etc.) and ecotones among them because of their dependence on duration of snow cover, water supply, wind and frost exposure, and other abiotic and biotic factors. © 1993 by the Ecological Society of America.

[The education and training of manpower in elderly & long-term care].

PubMed

Chen, Huey-Tzy

2008-08-01

With the rapid expansion of the aged population, elderly & long-term care has become a significant issue in Taiwan, as in many developed countries, such as Japan. Service resources in long-term care have benefitted profoundly from investment and development in the past 15 years in Taiwan, but the education and training of manpower in long-term care has only recently begun to be addressed. The purpose of this article is to describe the education and training of nursing manpower in long-term care in Taiwan and in other countries. Three recommendations are also made: (1) To integrate Gerontology Nursing & Practicum into the nursing curriculum to cultivate nursing students with competency in providing direct care and competency in accountability. (2) To prepare RN-BSN students with secondary competency in management/information & communication/activities design. (3) To incorporate faculty from across disciplines in the running of gerontology & long-term care programs in order to develop students' competency in transdisciplinary team work.

Intracellular pH Response to Weak Acid Stress in Individual Vegetative Bacillus subtilis Cells.

PubMed

Pandey, Rachna; Vischer, Norbert O E; Smelt, Jan P P M; van Beilen, Johan W A; Ter Beek, Alexander; De Vos, Winnok H; Brul, Stanley; Manders, Erik M M

2016-11-01

Intracellular pH (pH i ) critically affects bacterial cell physiology. Hence, a variety of food preservation strategies are aimed at perturbing pH i homeostasis. Unfortunately, accurate pH i quantification with existing methods is suboptimal, since measurements are averages across populations of cells, not taking into account interindividual heterogeneity. Yet, physiological heterogeneity in isogenic populations is well known to be responsible for differences in growth and division kinetics of cells in response to external stressors. To assess in this context the behavior of intracellular acidity, we have developed a robust method to quantify pH i at single-cell levels in Bacillus subtilis Bacilli spoil food, cause disease, and are well known for their ability to form highly stress-resistant spores. Using an improved version of the genetically encoded ratiometric pHluorin (IpHluorin), we have quantified pH i in individual B. subtilis cells, cultured at an external pH of 6.4, in the absence or presence of weak acid stresses. In the presence of 3 mM potassium sorbate, a decrease in pH i and an increase in the generation time of growing cells were observed. Similar effects were observed when cells were stressed with 25 mM potassium acetate. Time-resolved analysis of individual bacteria in growing colonies shows that after a transient pH decrease, long-term pH evolution is highly cell dependent. The heterogeneity at the single-cell level shows the existence of subpopulations that might be more resistant and contribute to population survival. Our approach contributes to an understanding of pH i regulation in individual bacteria and may help scrutinizing effects of existing and novel food preservation strategies. This study shows how the physiological response to commonly used weak organic acid food preservatives, such as sorbic and acetic acids, can be measured at the single-cell level. These data are key to coupling often-observed single-cell heterogeneous growth behavior upon the addition of weak organic acid food preservatives. Generally, these data are gathered in the form of plate counting of samples incubated with the acids. Here, we visualize the underlying heterogeneity in cellular pH homeostasis, opening up avenues for mechanistic analyses of the heterogeneity in the weak acid stress response. Thus, microbial risk assessment can become more robust, widening the scope of use of these well-known weak organic acid food preservatives. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Archaerhodopsin Selectively and Reversibly Silences Synaptic Transmission through Altered pH.

PubMed

El-Gaby, Mohamady; Zhang, Yu; Wolf, Konstantin; Schwiening, Christof J; Paulsen, Ole; Shipton, Olivia A

2016-08-23

Tools that allow acute and selective silencing of synaptic transmission in vivo would be invaluable for understanding the synaptic basis of specific behaviors. Here, we show that presynaptic expression of the proton pump archaerhodopsin enables robust, selective, and reversible optogenetic synaptic silencing with rapid onset and offset. Two-photon fluorescence imaging revealed that this effect is accompanied by a transient increase in pH restricted to archaerhodopsin-expressing boutons. Crucially, clamping intracellular pH abolished synaptic silencing without affecting the archaerhodopsin-mediated hyperpolarizing current, indicating that changes in pH mediate the synaptic silencing effect. To verify the utility of this technique, we used trial-limited, archaerhodopsin-mediated silencing to uncover a requirement for CA3-CA1 synapses whose afferents originate from the left CA3, but not those from the right CA3, for performance on a long-term memory task. These results highlight optogenetic, pH-mediated silencing of synaptic transmission as a spatiotemporally selective approach to dissecting synaptic function in behaving animals. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

[Soil pH buffer capacity of tea garden with different planting years].

PubMed

Su, You-Jian; Wang, Ye-Jun; Zhang, Yong-Li; Luo, Yi; Sun, Li; Song, Li; Liao, Wan-You

2014-10-01

In order to investigate the effects of long-term tea planting on soil pH buffer capacity (pHBC), the variation of pHBC and its influence factors were investigated in tea gardens of 10, 15, 20, 25 and 30 years in Langxi and Qimen of Anhui Province. The results showed that the acid-base titration method was suitable for the determination of soil pHBC of tea gardens. The amount of acid-base added had approximate linear relationship with soil pH value in specific section (pH 4.0-6.0) of acid-base titration curves, so the soil pHBC could be calculated by linear regression equation. Soil pHBC in the tea gardens from the two regions showed a downward trend with increasing the planting years, which decreased at rates of 0.10 and 0.06 mmol · kg(-1) · a(-1) in Langxi and Qimen tea gardens, respectively. Soil pHBC had significant positive correlation with CEC, soil organic matter, base saturation and physical clay content, and significant negative correlation with exchangeable acid and exchange H+.

Evaluation of acridine orange, LysoTracker Red, and quinacrine as fluorescent probes for long-term tracking of acidic vesicles.

PubMed

Pierzyńska-Mach, Agnieszka; Janowski, Paweł A; Dobrucki, Jurek W

2014-08-01

Acidic vesicles can be imaged and tracked in live cells after staining with several low molecular weight fluorescent probes, or with fluorescently labeled proteins. Three fluorescent dyes, acridine orange, LysoTracker Red DND-99, and quinacrine, were evaluated as acidic vesicle tracers for confocal fluorescence imaging and quantitative analysis. The stability of fluorescent signals, achievable image contrast, and phototoxicity were taken into consideration. The three tested tracers exhibit different advantages and pose different problems in imaging experiments. Acridine orange makes it possible to distinguish acidic vesicles with different internal pH but is fairly phototoxic and can cause spectacular bursts of the dye-loaded vesicles. LysoTracker Red is less phototoxic but its rapid photobleaching limits the range of useful applications considerably. We demonstrate that quinacrine is most suitable for long-term imaging when a high number of frames is required. This capacity made it possible to trace acidic vesicles for several hours, during a process of drug-induced apoptosis. An ability to record the behavior of acidic vesicles over such long periods opens a possibility to study processes like autophagy or long-term effects of drugs on endocytosis and exocytosis. © 2014 International Society for Advancement of Cytometry.

The impact of different flooding periods on the dynamics of pore water concentrations of As, Cr, Mo and V in a contaminated floodplain soil - results of a lysimeter study

NASA Astrophysics Data System (ADS)

Rupp, Holger; Meissner, Ralph; Shaheen, Sabry; Rinklebe, Jörg

2014-05-01

Trace elements and arsenic (As) were transported with water during inundation in floodplain ecosystems, where they settled down and accumulated predominantly in depressions and low-lying terraces. Highly variable hydrological conditions in floodplains can affect the dynamics of pollutants. The impact of different flooding/drying periods on the temporal dynamics of pore water concentrations of As, Cr, Mo and V as a function of soil EH/pH changes and dynamics of DOC, Fe, Mn and SO42- was studied in a contaminated floodplain soil collected at the Elbe River (Germany). A specific groundwater lysimeter technique with two separate small lysimeter vessels served as replicates was used for this study. The groundwater level inside the lysimeters was controlled to simulate long term and short term flooding/drying. The long term (LT) flooding scenario consists of 94 days of flooding followed by similar drying term. The short term (ST) flooding/drying scenario comprises 21 days and was six times repeated. The entire experimental period (LT_ST) was about 450 days. Flooding of the soil caused a significant decrease of EH and pH. Concentrations of soluble As, Cr, Fe, Mn, Mo and DOC were higher under reducing conditions than under oxidizing conditions in LT. However, As and Cr tended to be mobilized under oxidizing conditions during ST, which might be due to slow kinetics of the redox reaction of As and Cr. Dynamics of Mo were more affected by changes of EH/pH as compared to As, Cr and V and governed mainly by Fe-Mn chemistry. Concentrations of V in ST were higher than in LT and were controlled particularly by pH and chemistry of Fe. The interactions between the elements and carriers studied were stronger during long flood-dry-cycles than during short cycles, which confirmed our hypothesis. We conclude that the dynamics of As, Cr, Mo and V are determined by the length of time soils are exposed to flooding, because drivers of element mobility need a certain time to provoke reactions in soils under changing conditions.

Sea Hare Aplysia punctata (Mollusca: Gastropoda) Can Maintain Shell Calcification under Extreme Ocean Acidification.

PubMed

Carey, Nicholas; Dupont, Sam; Sigwart, Julia D

2016-10-01

Ocean acidification is expected to cause energetic constraints upon marine calcifying organisms such as molluscs and echinoderms, because of the increased costs of building or maintaining shell material in lower pH. We examined metabolic rate, shell morphometry, and calcification in the sea hare Aplysia punctata under short-term exposure (19 days) to an extreme ocean acidification scenario (pH 7.3, ∼2800 μatm pCO 2 ), along with a group held in control conditions (pH 8.1, ∼344 μatm pCO 2 ). This gastropod and its congeners are broadly distributed and locally abundant grazers, and have an internal shell that protects the internal organs. Specimens were examined for metabolic rate via closed-chamber respirometry, followed by removal and examination of the shell under confocal microscopy. Staining using calcein determined the amount of new calcification that occurred over 6 days at the end of the acclimation period. The width of new, pre-calcified shell on the distal shell margin was also quantified as a proxy for overall shell growth. Aplysia punctata showed a 30% reduction in metabolic rate under low pH, but calcification was not affected. This species is apparently able to maintain calcification rate even under extreme low pH, and even when under the energetic constraints of lower metabolism. This finding adds to the evidence that calcification is a largely autonomous process of crystallization that occurs as long as suitable haeomocoel conditions are preserved. There was, however, evidence that the accretion of new, noncalcified shell material may have been reduced, which would lead to overall reduced shell growth under longer-term exposures to low pH independent of calcification. Our findings highlight that the chief impact of ocean acidification upon the ability of marine invertebrates to maintain their shell under low pH may be energetic constraints that hinder growth of supporting structure, rather than maintenance of calcification.

Biotelemeters for Space Flights and Fetal Monitoring

NASA Technical Reports Server (NTRS)

Mundt, Carsten W.; Ricks, Robert D.; Hines, John W.

1999-01-01

Pill-shaped biotelemeters originally designed for space flight applications will soon be used for monitoring the health of a fetus during and after in-utero fetal surgery. The authors developed a family of biotelemeters that are not only small enough for rodent studies on board the space shuttle or international space station, but also fit through a 10 mm trocar, a plastic tube that is used in endoscopic fetal surgery to obtain minimally invasive access to the fetus. The first 'pill' measures pressure and temperature, and is currently undergoing long-term leakage and biocompatibility tests. A second pill under development measures pH and temperature. A prototype of the 'pH-pill' has been built and successfully tested and is presently being miniaturized into the same dimensions as the 'pressure pill'. Additional pills measuring heart rate, ECG, other ions such as calcium and potassium, and eventually glucose and blood gases, will follow. All pills are designed for ultra-low power consumption yielding lifetimes of up to 10 months in order to meet the requirements of fetal monitoring, but also to provide the capability of long-term space station experiments. Each pill transmits its pulse-interval-modulated signal on a unique carrier frequency in the frequency range of 174-216MHz. A custom-designed multi-channel receiver demodulates and decodes each pill signal and sends the data to a LabVIEW program that performs real-time data analysis and display. A patent for the pill family and its data analysis system is pending.

Culturing Fundamentals Used To Design And Execute A Long-Term Multi-stressor Experiment To Assess Impact Of Deoxygenation, Ocean Acidification, And Warming On Benthic Foraminiferal Community Composition, Growth, And Carbonate Yield: Design And Results

NASA Astrophysics Data System (ADS)

Bernhard, J. M.; Wit, J. C.

2015-12-01

The geochemistry recorded in carbonate foraminiferal tests (shells) is often used as proxy for past oceanographic events and environments. By understanding past oceanic and climatic conditions, we can better predict future climate scenarios, a relevant ability in these times of global change. The fact that foraminifera are biological entities can be pivotal for understanding their geochemical records. Thus, growing foraminifera under known physicochemical conditions and analyzing the geochemistry of their cultured carbonate can yield insightful perspectives for proxy refinement and development. Because parameters often co-vary in nature, proper proxy calibration can only be done with materials grown in strictly controlled and known environments. This presentation will review the various crucial aspects of foraminiferal maintenance and culturing, especially from the perspective of proxy development. These fundamentals were used to design a long-term multi-stressor experiment with oxygen, pCO2 (pH), and temperature as variables to test the single, double or triple threats of deoxygenation, ocean acidification, and oceanic warming. Results on assemblage composition, survivorship and growth of a continental shelf benthic foraminiferal community will be presented. Although one agglutinated morphospecies grew in each of the five treatments, growth of individual calcareous species was more restricted. Initial results indicate that pCO2 was not the factor that impacted communities most. Supported in part by NSF OCE-1219948.

Using Workflow Diagrams to Address Hand Hygiene in Pediatric Long-Term Care Facilities1

PubMed Central

Carter, Eileen J.; Cohen, Bevin; Murray, Meghan T.; Saiman, Lisa; Larson, Elaine L.

2015-01-01

Hand hygiene (HH) in pediatric long-term care settings has been found to be sub-optimal. Multidisciplinary teams at three pediatric long-term care facilities developed step-by-step workflow diagrams of commonly performed tasks highlighting HH opportunities. Diagrams were validated through observation of tasks and concurrent diagram assessment. Facility teams developed six workflow diagrams that underwent 22 validation observations. Four main themes emerged: 1) diagram specificity, 2) wording and layout, 3) timing of HH indications, and 4) environmental hygiene. The development of workflow diagrams is an opportunity to identify and address the complexity of HH in pediatric long-term care facilities. PMID:25773517

75 FR 76617 - Use of Community Development Loans by Community Financial Institutions To Secure Advances...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-09

... long term advances to CFI members for purposes of financing community development activities. Section... provided that a Bank could make a long-term advance to a member only for the purposes of providing funds to the member for residential housing finance, except that it also allowed long-term advances to CFI...

Scale-dependent temporal variations in stream water geochemistry.

PubMed

Nagorski, Sonia A; Moore, Iohnnie N; McKinnon, Temple E; Smith, David B

2003-03-01

A year-long study of four western Montana streams (two impacted by mining and two "pristine") evaluated surface water geochemical dynamics on various time scales (monthly, daily, and bi-hourly). Monthly changes were dominated by snowmelt and precipitation dynamics. On the daily scale, post-rain surges in some solute and particulate concentrations were similar to those of early spring runoff flushing characteristics on the monthly scale. On the bi-hourly scale, we observed diel (diurnal-nocturnal) cycling for pH, dissolved oxygen, water temperature, dissolved inorganic carbon, total suspended sediment, and some total recoverable metals at some or all sites. A comparison of the cumulative geochemical variability within each of the temporal groups reveals that for many water quality parameters there were large overlaps of concentration ranges among groups. We found that short-term (daily and bi-hourly) variations of some geochemical parameters covered large proportions of the variations found on a much longer term (monthly) time scale. These results show the importance of nesting short-term studies within long-term geochemical study designs to separate signals of environmental change from natural variability.

Scale-dependent temporal variations in stream water geochemistry

USGS Publications Warehouse

Nagorski, S.A.; Moore, J.N.; McKinnon, Temple E.; Smith, D.B.

2003-01-01

A year-long study of four western Montana streams (two impacted by mining and two "pristine") evaluated surface water geochemical dynamics on various time scales (monthly, daily, and bi-hourly). Monthly changes were dominated by snowmelt and precipitation dynamics. On the daily scale, post-rain surges in some solute and particulate concentrations were similar to those of early spring runoff flushing characteristics on the monthly scale. On the bi-hourly scale, we observed diel (diurnal-nocturnal) cycling for pH, dissolved oxygen, water temperature, dissolved inorganic carbon, total suspended sediment, and some total recoverable metals at some or all sites. A comparison of the cumulative geochemical variability within each of the temporal groups reveals that for many water quality parameters there were large overlaps of concentration ranges among groups. We found that short-term (daily and bi-hourly) variations of some geochemical parameters covered large proportions of the variations found on a much longer term (monthly) time scale. These results show the importance of nesting short-term studies within long-term geochemical study designs to separate signals of environmental change from natural variability.

Microencapsulation of Ascorbic Acid for Enhanced Long-term Retention during Storage

DTIC Science & Technology

2011-01-01

in fortified instant Asian noodles by use of capillary electrophoresis. Food Chemistry 112(2): 507–514. Hau Fung Cheung, R., Marriott, P.J . and...D., Small, D. M. and Marriott, P. J. (2008). Investigation of folic acid stability in fortified instant noodles by use of capillary electrophoresis...processing and preparation of instant Asian noodles . PhD thesis, RMIT University: Melbourne. Head, M.K. and Hansen, A.P. (1979). Stability of L

Evaluation of Short-Term Bioassays to Predict Functional Impairment. Selected Short-Term Hepatic Toxicity tests.

DTIC Science & Technology

1980-10-01

Thomas Ralph Wands Awadh Singh kor Lydia Thomas October 1980 Supported by US Army Medical Research and Development Command Fort Detrick, Frederick...Contracting Officer’s Technical Representative: D Mary C. Henry, Ph.D. US Army Medical Bloengineering Research and Development Laboratory I..., Fort...OFFICE NAME AND ADDRESS 12. REPORT DATE U.S. Army Medical Research and Development October 1980 Command 13. NUMBER OF PAGES Fort Detrick, Frederick

Transoral Incisionless Fundoplication (TIF 2.0): A Meta-Analysis of Three Randomized, Controlled Clinical Trials.

PubMed

Gerson, Lauren; Stouch, Bruce; Lobonţiu, Adrian

2018-01-01

The TIF procedure has emerged as an endoscopic treatment for patients with refractory gastro-esophageal reflux disease (GERD). Previous systematic reviews of the TIF procedure conflated findings from studies with modalities that do not reflect the current 2.0 procedure technique or refined data-backed patient selection criteria. A meta-analysis was conducted using data only from randomized studies that assessed the TIF 2.0 procedure compared to a control. The purpose of the meta-analysis was to determine the efficacy and long-term outcomes associated with performance of the TIF 2.0 procedure in patients with chronic long-term refractory GERD on optimized PPI therapy, including esophageal pH, PPI utilization and quality of life. Methods: Three prospective research questions were predicated on the outcomes of the TIF procedure compared to patients who received PPI therapy or sham, concomitant treatment for GERD, and the patient-reported quality of life. Event rates were calculated using the random effect model. Since the time of follow-up post-TIF procedure was variable, analysis was performed to incorporate the time of follow-up for each individual patient at the 3-year time point. Results: Results from this meta-analysis, including data from 233 patients, demonstrated that TIF subjects at 3 years had improved esophageal pH, a decrease in PPI utilization, and improved quality of life. Conclusions: In a meta-analysis of randomized, controlled trials (RCTs), the TIF procedure data for patients with GERD refractory to PPI's produces significant changes, compared with sham or PPI therapy, in esophageal pH, decreased PPI utilization, and improved quality of life. Celsius.

Multi-proxy experimental calibration in cold water corals for high resolution paleoreconstructions

NASA Astrophysics Data System (ADS)

Pelejero, C.; Martínez-Dios, A.; Ko, S.; Sherrell, R. M.; Kozdon, R.; López-Sanz, À.; Calvo, E.

2017-12-01

Cold-water corals (CWCs) display an almost cosmopolitan distribution over a wide range of depths. Similar to their tropical counterparts, they can provide continuous, high-resolution records of up to a century or more. Several CWC elemental and isotopic ratios have been suggested as useful proxies, but robust calibrations under controlled conditions in aquaria are needed. Whereas a few such calibrations have been performed for tropical corals, they are still pending for CWCs. This reflects the technical challenges involved in maintaining these slow-growing animals alive during the long-term experiments required to achieve sufficient skeletal growth for geochemical analyses. We will show details of the set up and initial stages of a long-term experiment being run at the ICM (Barcelona), where live specimens (>150) of Desmophyllum dianthus sampled in Comau Fjord (Chile) are kept under controlled and manipulated physical chemistry (temperature, pH, phosphate, barium, cadmium) and feeding conditions. With this set up, we aim to calibrate experimentally several specific elemental ratios including P/Ca, Ba/Ca, Cd/Ca, B/Ca, U/Ca and Mg/Li as proxies of nutrients dynamics, pH, carbonate ion concentration and temperature. For the trace element analysis, we are analyzing coral skeletons using Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS), running quantitative analyses on spot sizes of tens of microns, and comparing to micromilling and solution ICP-MS. Preliminary data obtained using these techniques will be presented, as well as measurements of calcification rate. Since coral-water corals are potentially vulnerable to ocean acidification, the same experiment is being exploited to assess potential effects of the pH stressor in D. dianthus; main findings to date will be summarized.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forsline, P.L.; Musselman, R.C.; Kender, W.J.

Mature 'McIntosh', 'Empire', and 'Golden Delicious' apple trees (Malus domestica Borkh.) were sprayed with simulated acid rain solutions in the pH range of 2.5 to 5.5 at full bloom in 1980 and in 1981. In 1981, weekly sprays were applied at pH 2.75 and pH 3.25. Necrotic lesions developed on apple petals at pH 2.5 with slight injury appearing at pH 3.0 and pH 3.5. Apple foliage had no acid rain lesions at any of the pH levels tested. Pollen germination was reduced at ph 2.5 in 'Empire'. Slight fruit set reduction at pH 2.5 was observed in 'McIntosh'. Themore » incidence of russetting on 'Golden Delicious' fruits was ameliorated by the presence of rain-exclusion chambers but was not affected by acid rain. With season-long sprays at pH 2.75, there was a slight delay in maturity and lower weight of 'McIntosh' apples. Even at the lowest pH levels no detrimental effects of simulated acid rain were found on apple tree productivity and fruit quality when measured as fruit set, seed number per fruit, and fruit size and appearance.« less

Municipal sludge metal contamination of old-field ecosystems: Do liming and tilling affect remediation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benninger-Truax, M.; Taylor, D.H.

1993-10-01

Mechanisms of ecosystem recovery following 11 years of sewage sludge disposal were addressed by examining the effects of tilling and/or liming on soil chemistry and the heavy metal (Cd, Cu, Pb, and Zn) concentrations in soil, earthworms, vegetation, spiders, and crickets. In 1989 and 1990, subplots in each of three former 0.1-ha, long-term treatments (sludge, fertilizer, and control) were either unmanipulated or manipulated via tilling and/or liming. Liming significantly increased the pH of soil from the long-term sludge and fertilizer plots, and the combination of tilling and liming affected the heavy metal concentrations in earthworms, as lower concentrations of Cd,more » Cu, Pb, and Zn were found in earthworms collected from subplots that had been both tilled and limed. However, most observed significant differences in heavy metal concentrations reflected the long-term treatments, as heavy metal concentrations tended to be greater in the soil and biota collected from sludge-treated plots. Thus, heavy metals remained in the soil in forms available to the biota, regardless of the cessation of sludge application or subplot manipulations (liming and/or tilling) for two years following cessation of sludge application.« less

Co-ensiling as a new technique for long-term storage of agro-industrial waste with low sugar content prior to anaerobic digestion.

PubMed

Hillion, Marie-Lou; Moscoviz, Roman; Trably, Eric; Leblanc, Yoann; Bernet, Nicolas; Torrijos, Michel; Escudié, Renaud

2018-01-01

Biodegradable wastes produced seasonally need an upstream storage, because of the requirement for a constant feeding of anaerobic digesters. In the present article, the potential of co-ensiling biodegradable agro-industrial waste (sugar beet leaves) and lignocellulosic agricultural residue (wheat straw) to obtain a mixture with low soluble sugar content was evaluated for long-term storage prior to anaerobic digestion. The aim is to store agro-industrial waste while pretreating lignocellulosic biomass. The dynamics of co-ensiling was evaluated in vacuum-packed bags at lab-scale during 180 days. Characterization of the reaction by-products and microbial communities showed a succession of metabolic pathways. Even though the low initial sugars content was not sufficient to lower the pH under 4.5 and avoid undesirable fermentations, the methane potential was not substantially impacted all along the experiment. No lignocellulosic damages were observed during the silage process. Overall, it was shown that co-ensiling was effective to store highly fermentable fresh waste evenly with low sugar content and offers new promising possibilities for constant long-term supply of industrial anaerobic digesters. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimization of scintillator loading with the tellurium-130 isotope for long-term stability

NASA Astrophysics Data System (ADS)

Duhamel, Lauren; Song, Xiaoya; Goutnik, Michael; Kaptanoglu, Tanner; Klein, Joshua; SNO+ Collaboration

2017-09-01

Tellurium-130 was selected as the isotope for the SNO + neutrinoless double beta decay search, as 130Te decays to 130Xe via double beta decay. Linear alkyl benzene(LAB) is the liquid scintillator for the SNO + experiment. To load tellurium into scintillator, it is combined with 1,2-butanediol to form an organometallic complex, commonly called tellurium butanediol (TeBD). This study focuses on maximizing the percentage of tellurium loaded into scintillator and evaluates the complex's long-term stability. Studies on the effect of nucleation due to imperfections in the detector's surface and external particulates were employed by filtration and induced nucleation. The impact of water on the stability of TeBD complex was evaluated by liquid-nitrogen sparging, variability in pH and induced humidity. Alternative loading methods were evaluated, including the addition of stability-inducing organic compounds. Samples of tellurium-loaded scintillator were synthesized, treated, and consistently monitored in a controlled environment. It was found that the hydronium ions cause precipitation in the loaded scintillator, demonstrating that water has a detrimental effect on long-term stability. Optimization of loaded scintillator stability can contribute to the SNO + double beta decay search.

Chitosan-Based Nanocomposite Beads for Drinking Water Production

NASA Astrophysics Data System (ADS)

Masheane, ML; Nthunya, LN; Sambaza, SS; Malinga, SP; Nxumalo, EN; Mamba, BB; Mhlanga, SD

2017-05-01

Potable drinking water is essential for the good health of humans and it is a critical feedstock in a variety of industries such as food and pharmaceutical industries. For the first time, chitosan-alumina/functionalised multiwalled carbon nanotube (f-MWCNT) nanocomposite beads were developed and investigated for the reduction of various physico-chemical parameters from water samples collected from open wells used for drinking purposes by a rural community in South Africa. The water samples were analysed before and after the reduction of the identified contaminants by the nanocomposite beads. The nanocomposite beads were effective in the removal of nitrate, chromium and other physico-chemical parameters. Although, the water samples contained these contaminants within the WHO and SANS241 limits for no risk, the long-term exposure and accumulation is an environmental and health concern. The reduction of these contaminants was dependent on pH levels. At lower pH, the reduction was significantly higher, up to 99.2% (SPC), 91.0% (DOC), 92.2% (DO), 92.2% (turbidity), 96.5% (nitrate) and 97.7% (chromium). Generally, the chitosan-alumina/f-MWCNT nanocomposite beads offer a promising alternative material for reduction and removal of various physico-chemical parameters for production portable water.

Direct damage to vegetation caused by acid rain and polluted cloud: definition of critical levels for forest trees.

PubMed

Cape, J N

1993-01-01

The concept of critical levels was developed in order to define short-term and long-term average concentrations of gaseous pollutants above which plants may be damaged. Although the usual way in which pollutants in precipitation (wet deposition) influence vegetation is by affecting soil processes, plant foliage exposed to fog and cloud, which often contain much greater concentrations of pollutant ions than rain, may be damaged directly. The idea of a critical level has been extended to define concentrations of pollutants in wet deposition above which direct damage to plants is likely. Concentrations of acidity and sulphate measured in mountain and coastal cloud are summarised. Vegetation at risk of injury is identified as montane forest growing close to the cloud base, where ion concentrations are highest. The direct effects of acidic precipitation on trees are reviewed, based on experimental exposure of plants to simulated acidic rain, fog or mist. Although most experiments have reported results in terms of pH (H(+) concentration), the accompanying anion is important, with sulphate being more damaging than nitrate. Both conifers and broadleaved tree seedlings showing subtle changes in the structural characteristics of leaf surfaces after exposure to mist or rain at or about pH 3.5, or sulphate concentration of 150 micromol litre(-1). Visible lesions on leaf surfaces occur at around pH 3 (500 micromol litre(-1) sulphate), broadleaved species tending to be more sensitive than conifers. Effects on photosynthesis and water relations, and interactions with other stresses (e.g. frost), have usually been observed only for treatments which have also caused visible injury to the leaf surface. Few experiments on the direct effects of polluted cloud have been conducted under field conditions with mature trees, which unlike seedlings in controlled conditions, may suffer a growth reduction in the absence of visible injury. Although leaching of cations (Ca(2+), Mg(2+), K(+)) is stimulated by acidic precipitation, amounts leached are small compared with root uptake, unless soils have been impoverished. This aspect of the potential effects of acidic precipitation is best considered in terms of the long-term critical-load of pollutants to the soil. Given the practical difficulties in monitoring cloud water composition, a method for defining critical levels is proposed, which uses climatological average data to identify the duration and frequency of hill cloud, and combines this information with measured or modelled concentrations of particulate sulphate in the atmosphere, to derive cloud water concentrations as a function of cloud liquid water content. For forests within 100 m of the cloud base the critical levels of particulate sulphate, corresponding to solution concentrations in the range 150-500 micromol litre(-1), are in the range 1-3.3 microg S m(-3). These concentrations are observed over much of central Europe, suggesting that many montane forests are at risk of direct effects of fossil-fuel-derived pollutants in cloud.

Reaction modeling of drainage quality in the Duluth Complex, northern Minnesota, USA

USGS Publications Warehouse

Seal, Robert; Lapakko, Kim; Piatak, Nadine; Woodruff, Laurel G.

2015-01-01

Reaction modeling can be a valuable tool in predicting the long-term behavior of waste material if representative rate constants can be derived from long-term leaching tests or other approaches. Reaction modeling using the REACT program of the Geochemist’s Workbench was conducted to evaluate long-term drainage quality affected by disseminated Cu-Ni-(Co-)-PGM sulfide mineralization in the basal zone of the Duluth Complex where significant resources have been identified. Disseminated sulfide minerals, mostly pyrrhotite and Cu-Fe sulfides, are hosted by clinopyroxene-bearing troctolites. Carbonate minerals are scarce to non-existent. Long-term simulations of up to 20 years of weathering of tailings used two different sets of rate constants: one based on published laboratory single-mineral dissolution experiments, and one based on leaching experiments using bulk material from the Duluth Complex conducted by the Minnesota Department of Natural Resources (MNDNR). The simulations included only plagioclase, olivine, clinopyroxene, pyrrhotite, and water as starting phases. Dissolved oxygen concentrations were assumed to be in equilibrium with atmospheric oxygen. The simulations based on the published single-mineral rate constants predicted that pyrrhotite would be effectively exhausted in less than two years and pH would rise accordingly. In contrast, only 20 percent of the pyrrhotite was depleted after two years using the MNDNR rate constants. Predicted pyrrhotite depletion by the simulation based on the MNDNR rate constant matched well with published results of laboratory tests on tailings. Modeling long-term weathering of mine wastes also can provide important insights into secondary reactions that may influence the permeability of tailings and thereby affect weathering behavior. Both models predicted the precipitation of a variety of secondary phases including goethite, gibbsite, and clay (nontronite).

Proceedings of the 2017 annual meeting of the Fetal Alcohol Spectrum Disorders study group.

PubMed

Wozniak, Jeffrey R; Klintsova, Anna Y; Hamilton, Derek A; Mooney, Sandra M

2018-06-01

The 2017 Fetal Alcohol Spectrum Disorders Study Group (FASDSG) meeting was titled "Prenatal alcohol exposure in the context of multiple factors affecting brain development." The theme was reflected in the interactions between members of the Teratology Society and the FASDSG this year. The first keynote speaker, Elaine Faustman, Ph.D., was a liaison between the societies and spoke about systems biology and the multiple genetic and environmental influences on development. The second keynote speaker, Rebecca Knickmeyer, Ph.D., discussed population neuroscience and multiple influences on brain development. The conference presented updates from three government agencies and short presentations by junior and senior investigators showcasing late-breaking FASD research. The conference was capped by Dr. John Hannigan, Ph.D., the recipient of the 2017 Henry Rosett award for career-long contributions to the field. Copyright © 2017 Elsevier Inc. All rights reserved.

VALIDATION OF A METHOD FOR ESTIMATING LONG-TERM EXPOSURES BASED ON SHORT-TERM MEASUREMENTS

EPA Science Inventory

A method for estimating long-term exposures from short-term measurements is validated using data from a recent EPA study of exposure to fine particles. The method was developed a decade ago but long-term exposure data to validate it did not exist until recently. In this paper, ...

Molecular adsorption at electrolyte/α-Al2O3 interface of aluminum electrolytic capacitor revealed by sum frequency vibrational spectroscopy.

PubMed

Jia, Ming; Hu, Xiaoyu; Liu, Jin; Liu, Yexiang; Ai, Liang

2017-05-21

The operating voltage of an aluminum electrolytic capacitor is determined by the breakdown voltage (U b ) of the Al 2 O 3 anode. U b is related to the molecular adsorption at the Al 2 O 3 /electrolyte interface. Therefore, we have employed sum-frequency vibrational spectroscopy (SFVS) to study the adsorption states of a simple electrolyte, ethylene glycol (EG) solution with ammonium adipate, on an α-Al 2 O 3 surface. In an acidic electrolyte (pH < 6), the Al 2 O 3 surface is positively charged. The observed SFVS spectra show that long chain molecules poly ethylene glycol and ethylene glycol adipate adopt a "lying" orientation at the interface. In an alkaline electrolyte (pH > 8), the Al 2 O 3 surface is negatively charged and the short chain EG molecules adopt a "tilting" orientation. The U b results exhibit a much higher value at pH < 6 compared with that at pH > 8. Since the "lying" long chain molecules cover and protect the Al 2 O 3 surface, U b increases with a decrease of pH. These findings provide new insights to study the breakdown mechanisms and to develop new electrolytes for high operating voltage capacitors.

Developmental and anatomical changes in leaves of yellow birch and red kidney bean exposed to simulated acid precipitation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paparozzi, E.T.; Tukey, H.B. Jr.

Leaves of Betula alleghaniensis Britt. (yellow birch) and Phaseolus vulgaris L cv. Red Kidney (bean) were examined microscopically during development and after exposure to simulated rain of pH 5.5, 4.3, 3.2, and 2.8. Yellow birch leaves attained maximal leaf area, midvein length, and cuticle thickness at 21 days. Trichomes were either long, unicellular, or multicellular with caplike head and stalk. Epicuticular wax was a bumpy and amorphous layer. The 2nd trifoliolate leaf of red kidney bean attained maximal leaf area, midvein length, and cuticle thickness when the 3rd trifoliolate leaf was expanding. Trichomes present were long, with a unicellular headmore » and a multicellular base; long, unicellular, and terminally hooked; and small and multicellular. Epicuticular wax was present as small irregular flakes. After 2 days of pH 2.8 and 4 days of pH 3.2 simulated acid rain, round yellow and small tan lesions appeared on birch and bean leaves, respectively. Most injury occurred on or between small veins. Most trichome types were uninjured. Lesions formed as a result of collapsed epidermal and highly plasmolyzed palisade cells. The cuticle was still present over injured epidermal cells and epicuticular waxes were unchanged. There was not statistical difference in mean cuticle thickness due to pH of simulated rain. 25 references, 10 figures, 4 tables.« less

Effects of solution pH and electrical parameters on hydroxyapatite coatings deposited by a plasma-assisted electrophoresis technique.

PubMed

Nie, X; Leyland, A; Matthews, A; Jiang, J C; Meletis, E I

2001-12-15

Hydroxyapatite (HA) coatings can be deposited using a hybrid process of plasma electrolysis and electrophoresis, called plasma-assisted electrophoretic deposition (PEPD). HA aqueous suspensions with various pH values were prepared using a modified ultrasonic cleaning bath as an agitator/stirrer. Both DC and unbalanced AC power supplies were used to bias the titanium alloy substrate materials employed in this work. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractometry (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to observe and analyze coating morphology and microstructure. It was shown that the morphology and composition of the calcium phosphate coatings were significantly influenced by solution pH values; the level of "pure" HA in the coatings' composition corresponded to both solution pH and the type of power supply employed. Loss of hydroxyl radials (i.e., dehydroxylation), which degrades the performance of the hydroxyapatite coating in terms of long-term chemical and mechanical stability, can be virtually eliminated by a combination of high pH and unbalanced AC plasma power. In addition, the underlying TiO2 coatings used to support the HA layer (preproduced by plasma electrolysis process) have a nanoscaled (10-20 nm) polycrystalline structure. TEM studies also revealed a dense, continuous amorphous titania layer (10 nm in thickness) at the interface between the Ti alloy substrate and the TiO2 layer, which may play a role in improving the corrosion resistance of the substrate. Such a nanophase TiO2 layer (if used as a coating alone) may also provide a further improvement in osteoinductive properties, compared to a conventional TiO2 coating on the Ti alloy substrate. Copyright 2001 John Wiley & Sons, Inc. J Biomed Mater Res 57: 612-618, 2001

Acid-base physiology response to ocean acidification of two ecologically and economically important holothuroids from contrasting habitats, Holothuria scabra and Holothuria parva.

PubMed

Collard, Marie; Eeckhaut, Igor; Dehairs, Frank; Dubois, Philippe

2014-12-01

Sea cucumbers are dominant invertebrates in several ecosystems such as coral reefs, seagrass meadows and mangroves. As bioturbators, they have an important ecological role in making available calcium carbonate and nutrients to the rest of the community. However, due to their commercial value, they face overexploitation in the natural environment. On top of that, occurring ocean acidification could impact these organisms, considered sensitive as echinoderms are osmoconformers, high-magnesium calcite producers and have a low metabolism. As a first investigation of the impact of ocean acidification on sea cucumbers, we tested the impact of short-term (6 to 12 days) exposure to ocean acidification (seawater pH 7.7 and 7.4) on two sea cucumbers collected in SW Madagascar, Holothuria scabra, a high commercial value species living in the seagrass meadows, and H. parva, inhabiting the mangroves. The former lives in a habitat with moderate fluctuations of seawater chemistry (driven by day-night differences) while the second lives in a highly variable intertidal environment. In both species, pH of the coelomic fluid was significantly negatively affected by reduced seawater pH, with a pronounced extracellular acidosis in individuals maintained at pH 7.7 and 7.4. This acidosis was due to an increased dissolved inorganic carbon content and pCO2 of the coelomic fluid, indicating a limited diffusion of the CO2 towards the external medium. However, respiration and ammonium excretion rates were not affected. No evidence of accumulation of bicarbonate was observed to buffer the coelomic fluid pH. If this acidosis stays uncompensated for when facing long-term exposure, other processes could be affected in both species, eventually leading to impacts on their ecological role.

Vertical garden for treating greywater

NASA Astrophysics Data System (ADS)

McDonald, Arthur Phaoenchoke; Montoya, Alejandro; Alonso-Marroquin, Fernando

2017-06-01

Recent increasing concerns over the effects of climate change has prompted much debate into the issue of long term sustainability. An investigation was conducted into the feasibility of an off-grid housing unit, particularly in an Australian context. A pilot scale 3m × 2m off-grid housing unit was constructed. Forecasts for water requirements as well as an investigation into rainwater harvesting and greywater recycling was conducted. A multi-container plant and sand biological filter was constructed and filtration abilities investigated. The system met NSW government water reuse standards in terms of suspended solids and pH, achieving total suspended solid removal efficiency of up to 99%.

Effect of Xyloglucan Oligosaccharides on Growth, Viscoelastic Properties, and Long-Term Extension of Pea Shoots.

PubMed Central

Cutillas-Iturralde, A.; Lorences, E. P.

1997-01-01

The growth-promoting effect of xyloglucan-derived oligosaccharides was investigated using a bioassay with entire pea (Pisum sativum L., var Alaska) shoots. After a 24-h incubation period at 25[deg]C, xyloglucan oligosaccharide (XGO) solutions with concentrations of 10-6 M notably increased the growth rate of pea shoots, whereas the same oligosaccharides at 10-7 M were less effective. To investigate the possible correlation between growth rate changes in the XGO-treated shoots and changes in the wall mechanical properties of their growing regions (third internodes), we used a short-term creep assay. The promotion of elongation by XGOs was reflected in an enhancement of the viscoelasticity of the growing regions of the shoots. To show whether this effect on wall viscoelastic properties was the cause or a consequence of their growth promotion, we tested the effect of XGOs on the long-term extension of isolated cell walls. We characterized an acid-induced extension in isolated cell walls from pea shoots that was not inhibited by preincubation in neutral buffers. Exogenously added XGOs did not alter the pattern of pea segment extension at any pH tested, indicating that XGOs have no direct effect on cell wall viscoelasticity. Finally, preincubation of pea segments in neutral buffers with XGOs enhanced their capacity to extend under acidic conditions. This finding suggests that XGOs at a neutral pH can act via transglycosylation, weakening the wall matrix and making the wall more responsive to other mechanisms of acid-induced extension as an expansin-mediated extension. PMID:12223593

The discovery of long-term potentiation.

PubMed Central

Lømo, Terje

2003-01-01

This paper describes circumstances around the discovery of long-term potentiation (LTP). In 1966, I had just begun independent work for the degree of Dr medicinae (PhD) in Per Andersen's laboratory in Oslo after an eighteen-month apprenticeship with him. Studying the effects of activating the perforant path to dentate granule cells in the hippocampus of anaesthetized rabbits, I observed that brief trains of stimuli resulted in increased efficiency of transmission at the perforant path-granule cell synapses that could last for hours. In 1968, Tim Bliss came to Per Andersen's laboratory to learn about the hippocampus and field potential recording for studies of possible memory mechanisms. The two of us then followed up my preliminary results from 1966 and did the experiments that resulted in a paper that is now properly considered to be the basic reference for the discovery of LTP. PMID:12740104

Comparison of Hexavalent Chromium Leaching Levels of Zeoliteand Slag-based Concretes

NASA Astrophysics Data System (ADS)

Oravec, Jozef; Eštoková, Adriana

2017-06-01

In this experiment, the reference concrete samples containing Portland cement as binder and the concrete samples with the addition of ground granulated blast furnace slag (85% and 95%, respectively as replacement of Portland cement) and other samples containing ground zeolite (8% and 13%, respectively as replacement of Portland cement) were analyzed regarding the leachability of chromium. The prepared concrete samples were subjected to long-term leaching test for 300 days in three different leaching agents (distilled water, rainwater and Britton-Robinson buffer). Subsequently, the concentration of hexavalent chromium in the various leachates spectrophotometrically was measured. The leaching parameters as values of the pH and the conductivity were also studied. This experiment clearly shows the need for the regulation and control of the waste addition to the construction materials and the need for long-term study in relation to the leaching of heavy metals into the environment.

A Method to Biomonitor the Cooked Meat Carcinogen 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in Dyed Hair by Ultra Performance Liquid Chromatography-Orbitrap High Resolution Multistage Mass Spectrometry

PubMed Central

Guo, Jingshu; Yonemori, Kim; Le Marchand, Loïc; Turesky, Robert J.

2015-01-01

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a carcinogenic heterocyclic aromatic amine formed in cooked meat. The use of naturally colored hair containing PhIP can serve as a long-term biomarker of exposure to this carcinogen. However, the measurement of PhIP in dyed hair, a cosmetic treatment commonly used by the adult population, is challenging because the dye process introduces a complex mixture of chemicals into the hair matrix, which interfere with the measurement of PhIP. The high-resolution scanning features of the Orbitrap Fusion™ mass spectrometer were employed to biomonitor PhIP in dyed hair. Because of the complexity of chemicals in the hair dye, the consecutive reaction monitoring of PhIP at the MS3 scan stage was employed to selectively remove the isobaric interferences. The limit of quantification (LOQ) of PhIP was 84 parts-per-trillion (ppt) employing 50 mg hair. Calibration curves were generated in dyed hair matrices and showed good linearity (40 to 1000 pg PhIP/g hair) with a goodness-of-fit regression value r2 > 0.9978. The within-day (between-day) coefficients of variation were 7.7% (17%) and 5.4% (6.1%), respectively, with dyed hair samples spiked with PhIP at 200 and 600 ppt. The levels of PhIP accrued in dyed hair from volunteers on a semi-controlled feeding study who ingested known levels of PhIP were comparable to the levels of PhIP accrued in hair of subjects with natural hair color. The method was successfully employed to measure PhIP in non-dyed and dyed hair biospecimens of participants in a case-control study of colorectal adenoma on their regular diet. PMID:25969997

Effect of pH on ethanol-type acidogenic fermentation of fruit and vegetable waste.

PubMed

Wu, Yuanyuan; Wang, Cuiping; Zheng, Mingyue; Zuo, Jiane; Wu, Jing; Wang, Kaijun; Yang, Boqiong

2017-02-01

The aim of this study was to investigate the possibility and optimal controlling strategy for ethanol-type acidogenic fermentation of fruit and vegetable waste by mixed microbial cultures. Four continuous stirred tank reactors (CSTR) were operated at various pHs (4.0, 5.0, 5.5, and 6.0) with an organic loading rate of 13gVS/(Ld) and hydraulic retention time of 3d. Butyrate-type fermentation was observed at pH 5.0, 5.5, and 6.0. Conversely, at pH 4.0, ethanol-type fermentation was observed with a high mass concentration and proportion (of total fermentative products) of ethanol, which were 6.7g/L and 88.8%, respectively. However, the total concentration of ethanol-type fermentative products substantially decreased from days 22-25. The optimal pH of ethanol-type fermentative microorganisms was investigated by using batch experiments with pH controlled at 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, and 7.0 and results showed that the maximum ethanol concentration and relatively highest acidogenic rate were found at pH of 5.5. The pH in the long term CSTR was changed from 4.0 to 5.5 to improve ethanol-type fermentation and results showed that ethanol-type fermentation was improved temporarily, however, was followed by the reappearance of butyrate-type fermentation. In addition, ethanol-type fermentation recovered once more when pH was reverted to 4.0. Therefore, the results of this study suggest that a process of dynamic, sequenced pH control with the order pH 4.0, 5.5 and 4.0 might be a feasible controlling strategy for continuous and stable ethanol-type fermentation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Repeated Famotidine Administration Results in a Diminished Effect on Intragastric pH in Dogs.

PubMed

Tolbert, M K; Graham, A; Odunayo, A; Price, J; Steiner, J M; Newkirk, K; Hecht, S

2017-01-01

Famotidine is an acid suppressant commonly administered to dogs. Prolonged famotidine use in people results in decreased efficacy, but the effect in dogs is unknown. To compare the effect of repeated oral administration of famotidine or placebo on intragastric pH and serum gastrin in dogs. We hypothesized that famotidine would have a diminished effect on intragastric pH on day 13 compared to day 1. Six healthy adult colony Beagles. Randomized, 2-factor repeated-measures crossover design. All dogs received oral placebo or 1.0 mg/kg famotidine q12h for 14 consecutive days. Intragastric pH monitoring was used to continuously record intragastric pH on treatment days 1-2 and 12-13. Mean pH as well as mean percentage time (MPT) that intragastric pH was ≥3 or ≥4 were compared between and within groups by analysis of variance. Serum gastrin was measured on days 0, 3, and 12 for each treatment. Continued administration of famotidine resulted in a significant decrease in mean pH, MPT ≥3, and MPT ≥4 (P < .0001) on day 12 and 13. This resulted in a mean decrease in pH by 1.63 on days 12 and 13 compared to days 1 and 2. Furthermore, a mean decrease of MPT ≥3 and MPT ≥4 by 33 and 45% was observed for the same time period, respectively. Continued administration of famotidine results in a diminished effect on intragastric pH in dogs. Caution is advised when recommending long-term, daily oral administration of famotidine to dogs. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Staff Perceptions of Professional Development and Empowerment as Long-Term Leadership Tasks of School Principals in South African Schools: An Exploratory Study

ERIC Educational Resources Information Center

van Niekerk, Eldridge; Muller, Hélène

2017-01-01

This article reports on the perceptions of school staff of professional development and empowerment as part of the long-term leadership task of principals. The long-term leadership model was used as a theoretical framework to quantitatively determine the perceptions of 118 teachers and education managers in approximately 100 schools throughout…

In Situ Live-Cell Nucleus Fluorescence Labeling with Bioinspired Fluorescent Probes.

PubMed

Ding, Pan; Wang, Houyu; Song, Bin; Ji, Xiaoyuan; Su, Yuanyuan; He, Yao

2017-08-01

Fluorescent imaging techniques for visualization of nuclear structure and function in live cells are fundamentally important for exploring major cellular events. The ideal cellular labeling method is capable of realizing label-free, in situ, real-time, and long-term nucleus labeling in live cells, which can fully obtain the nucleus-relative information and effectively alleviate negative effects of alien probes on cellular metabolism. However, current established fluorescent probes-based strategies (e.g., fluorescent proteins-, organic dyes-, fluorescent organic/inorganic nanoparticles-based imaging techniques) are unable to simultaneously realize label-free, in situ, long-term, and real-time nucleus labeling, resulting in inevitable difficulties in fully visualizing nuclear structure and function in live cells. To this end, we present a type of bioinspired fluorescent probes, which are highly efficacious for in situ and label-free tracking of nucleus in long-term and real-time manners. Typically, the bioinspired polydopamine (PDA) nanoparticles, served as fluorescent probes, can be readily synthesized in situ within live cell nucleus without any further modifications under physiological conditions (37 °C, pH ∼7.4). Compared with other conventional nuclear dyes (e.g., propidium iodide (PI), Hoechst), superior spectroscopic properties (e.g., quantum yield of ∼35.8% and high photostability) and low cytotoxicity of PDA-based probes enable long-term (e.g., 3 h) fluorescence tracking of nucleus. We also demonstrate the generality of this type of bioinspired fluorescent probes in different cell lines and complex biological samples.

Coral records of reef-water pH across the central Great Barrier Reef, Australia: assessing the influence of river runoff on inshore reefs

NASA Astrophysics Data System (ADS)

D'Olivo, J. P.; McCulloch, M. T.; Eggins, S. M.; Trotter, J.

2014-07-01

The boron isotopic (δ11Bcarb) compositions of long-lived Porites coral are used to reconstruct reef-water pH across the central Great Barrier Reef (GBR) and assess the impact of river runoff on inshore reefs. For the period from 1940 to 2009, corals from both inner as well as mid-shelf sites exhibit the same overall decrease in δ11Bcarb of 0.086 ± 0.033‰ per decade, equivalent to a~decline in seawater pH (pHsw) of ~ 0.017 ± 0.007 pH units per decade. This decline is consistent with the long-term effects of ocean acidification based on estimates of CO2 uptake by surface waters due to rising atmospheric levels. We also find that compared to the mid-shelf corals, the δ11Bcarb compositions for inner shelf corals subject to river discharge events, have higher and more variable values and hence higher inferred pHsw values. These higher δ11Bcarb values for inner-shelf corals are particularly evident during wet years, despite river waters having lower pH. The main effect of river discharge on reef-water carbonate chemistry thus appears to be from higher nutrients driving increased phytoplankton productivity, resulting in the drawdown of pCO2 and increase in pHsw. Increased primary production therefore has the potential to counter the more transient effects of low pH river water (pHrw) discharged into near-shore environments. Importantly however, inshore reefs also show a consistent pattern of sharply declining coral growth that coincides with periods of high river discharge. This occurs despite these reefs having higher pHsw values and hence higher seawater aragonite saturation states, demonstrating the over-riding importance of local reef-water quality on coral reef health.

Management of gastroesophageal reflux disease.

PubMed

Tutuian, Radu; Castell, Donald O

2003-11-01

Gastroesophageal reflux disease (GERD) is a chronic condition requiring long-term treatment. Simple lifestyle modifications are the first methods employed by patients and, because of their low cost and simplicity, should be continued even when more potent therapies are initiated. Potent acid-suppressive therapy is currently the most important and successful medical therapy. Whereas healing of the esophageal mucosa is achieved with a single dose of any proton pump inhibitor (PPI) in more than 80% of cases, symptoms are more difficult to control. Patients with persistent symptoms on therapy should be tested (preferably with combined multichannel intraluminal impedance and pH) for association of symptoms with acid, nonacid, or no GER. Long-term follow-up studies indicate that PPIs are efficacious, tolerable, and safe medication. So far, promotility agents have shown limited efficacy, and their side-effect profile outweighs their benefits. Antireflux surgery in carefully selected patients (ie, young, typical GERD symptoms, abnormal pH study, and good response to PPI) is as effective as PPI therapy and should be offered to these patients as an alternative to medication. Still, patients should be informed about the risks of antireflux surgery (ie, risk of postoperative dysphagia; decreased ability to belch, possibly leading to bloating; increased flatulence). Endoscopic antireflux procedures are recommended only in selected patients and given the relative short experience with these techniques, patients treated with endoscopic procedures should be enrolled in a rigorous follow-up program.

In situ spectrophotometric measurement of dissolved inorganic carbon in seawater

USGS Publications Warehouse

Liua, Xuewu; Byrne, Robert H.; Adornato, Lori; Yates, Kimberly K.; Kaltenbacher, Eric; Ding, Xiaoling; Yang, Bo

2013-01-01

Autonomous in situ sensors are needed to document the effects of today’s rapid ocean uptake of atmospheric carbon dioxide (e.g., ocean acidification). General environmental conditions (e.g., biofouling, turbidity) and carbon-specific conditions (e.g., wide diel variations) present significant challenges to acquiring long-term measurements of dissolved inorganic carbon (DIC) with satisfactory accuracy and resolution. SEAS-DIC is a new in situ instrument designed to provide calibrated, high-frequency, long-term measurements of DIC in marine and fresh waters. Sample water is first acidified to convert all DIC to carbon dioxide (CO2). The sample and a known reagent solution are then equilibrated across a gas-permeable membrane. Spectrophotometric measurement of reagent pH can thereby determine the sample DIC over a wide dynamic range, with inherent calibration provided by the pH indicator’s molecular characteristics. Field trials indicate that SEAS-DIC performs well in biofouling and turbid waters, with a DIC accuracy and precision of ∼2 μmol kg–1 and a measurement rate of approximately once per minute. The acidic reagent protects the sensor cell from biofouling, and the gas-permeable membrane excludes particulates from the optical path. This instrument, the first spectrophotometric system capable of automated in situ DIC measurements, positions DIC to become a key parameter for in situ CO2-system characterizations.

The Infant Skin Barrier: Can We Preserve, Protect, and Enhance the Barrier?

PubMed Central

Telofski, Lorena S.; Morello, A. Peter; Mack Correa, M. Catherine; Stamatas, Georgios N.

2012-01-01

Infant skin is different from adult in structure, function, and composition. Despite these differences, the skin barrier is competent at birth in healthy, full-term neonates. The primary focus of this paper is on the developing skin barrier in healthy, full-term neonates and infants. Additionally, a brief discussion of the properties of the skin barrier in premature neonates and infants with abnormal skin conditions (i.e., atopic dermatitis and eczema) is included. As infant skin continues to mature through the first years of life, it is important that skin care products (e.g., cleansers and emollients) are formulated appropriately. Ideally, products that are used on infants should not interfere with skin surface pH or perturb the skin barrier. For cleansers, this can be achieved by choosing the right type of surfactant, by blending surfactants, or by blending hydrophobically-modified polymers (HMPs) with surfactants to increase product mildness. Similarly, choosing the right type of oil for emollients is important. Unlike some vegetable oils, mineral oil is more stable and is not subject to oxidation and hydrolysis. Although emollients can improve the skin barrier, more studies are needed to determine the potential long-term benefits of using emollients on healthy, full-term neonates and infants. PMID:22988452

Changes in wintertime pH and hydrography of the Gulf of Finland (Baltic Sea) with focus on depth layers.

PubMed

Almén, Anna-Karin; Glippa, Olivier; Pettersson, Heidi; Alenius, Pekka; Engström-Öst, Jonna

2017-04-01

We studied changes in sea water pH, temperature and salinity with focus on two depth layers, along the Gulf of Finland (the Baltic Sea) using long-term monitoring data from 1979 to 2015. Data from the most frequently sampled monitoring stations between western and eastern Gulf of Finland were used. The main result of the study reveals that pH has decreased both in surface and deep-water in the western Gulf of Finland with values ranging between -0.005 and -0.008 units year -1 . We also demonstrate a rise in temperature (~2 °C) and decrease in salinity (~-0.7 g kg -1 ) at several stations over the last 36 years. In general, the changes are shown to be more pronounced in the western part of the gulf. This paper also stresses the importance of improving the sampling frequency and quality of monitoring measurements.

A long-term static immersion experiment on the leaching behavior of heavy metals from waste printed circuit boards.

PubMed

Zhao, Guo-Hua; Luo, Xing-Zhang; Chen, Gui; Zhao, Yong-Jun

2014-08-01

Printed circuit boards (PCBs) are the main components of electrical and electronic equipment (EEE). Waste PCBs contain several kinds of heavy metals, including Cu, Pb and Zn. We characterize the leaching of heavy metals (Cu, Pb, Zn and Ni) from waste PCBs in a pH range of 3.0 to 5.6 using a novel approach based on batch pH-static leaching experiments in this work. The results indicate that the leaching behavior of Cu, Pb, Zn and Ni is strongly dependent on pH. Leaching behavior also varies with different pH values and leaching times. The maximum concentrations of Cu, Pb, Zn and Ni in leachate from waste PCBs were 335.00, 17.57, 2.40 and 2.33 mg L(-1), respectively. The highest Pb, Ni, and Cu concentrations leached significantly exceeded the European Union waste-acceptance limit values with respect to inert waste landfills. The leaching of metals follows the shrinking core model with surface reaction control.

Non-sticky translocation of bio-molecules through Tween 20-coated solid-state nanopores in a wide pH range

NASA Astrophysics Data System (ADS)

Li, Xiaoqing; Hu, Rui; Li, Ji; Tong, Xin; Diao, J. J.; Yu, Dapeng; Zhao, Qing

2016-10-01

Nanopore-based sensing technology is considered high-throughput and low-cost for single molecule detection, but solid-state nanopores have suffered from pore clogging issues. A simple Tween 20 coating method is applied to ensure long-term (several hours) non-sticky translocation of various types of bio-molecules through SiN nanopores in a wide pH range (4.0-13.0). We also emphasize the importance of choosing appropriate concentration of Tween 20 coating buffer for desired effect. By coating nanopores with a Tween 20 layer, we are able to differentiate between single-stranded DNA and double-stranded DNA, to identify drift-dominated domain for single-stranded DNA, to estimate BSA volume and to observe the shape of individual nucleosome translocation event without non-specific adsorption. The wide pH endurance from 4.0 to 13.0 and the broad types of detection analytes including nucleic acids, proteins, and biological complexes highlight the great application potential of Tween 20-coated solid-state nanopores.

The Canadian clinician-scientist training program must be reinstated.

PubMed

Twa, David D W; Squair, Jordan W; Skinnider, Michael A; Ji, Jennifer X

2015-11-03

Clinical investigators within the Canadian and international communities were shocked when the Canadian Institutes of Health Research (CIHR) announced that their funding for the MD/PhD program would be terminated after the 2015-2016 academic year. The program has trained Canadian clinician-scientists for more than two decades. The cancellation of the program is at odds with the CIHR's mandate, which stresses the translation of new knowledge into improved health for Canadians, as well as with a series of internal reports that have recommended expanding the program. Although substantial evidence supports the analogous Medical Scientist Training Program in the United States, no parallel analysis of the MD/PhD program has been performed in Canada. Here, we highlight the long-term consequences of the program's cancellation in the context of increased emphasis on translational research. We argue that alternative funding sources cannot ensure continuous support for students in clinician-scientist training programs and that platform funding of the MD/PhD program is necessary to ensure leadership in translational research.

Degradable Molybdenum Oxide Nanosheets with Rapid Clearance and Efficient Tumor Homing Capabilities as a Therapeutic Nanoplatform.

PubMed

Song, Guosheng; Hao, Jiali; Liang, Chao; Liu, Teng; Gao, Min; Cheng, Liang; Hu, Junqing; Liu, Zhuang

2016-02-05

Molybdenum oxide (MoOx) nanosheets with high near-infrared (NIR) absorbance and pH-dependent oxidative degradation properties were synthesized, functionalized with polyethylene glycol (PEG), and then used as a degradable photothermal agent and drug carrier. The nanosheets, which are relatively stable under acidic pH, could be degraded at physiological pH. Therefore, MoOx-PEG distributed in organs upon intravenous injection would be rapidly degraded and excreted without apparent in vivo toxicity. MoOx-PEG shows efficient accumulation in tumors, the acidic pH of which then leads to longer tumor retention of those nanosheets. Along with the capability of acting as a photothermal agent for effective tumor ablation, MoOx-PEG can load therapeutic molecules with high efficiencies. This concept of inorganic theranostic nanoagent should be relatively stable in tumors to allow imaging and treatment, while being readily degradable in normal organs to enable rapid excretion and avoid long-term retention/toxicity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Breeding biology of the spotted salamander Ambystoma maculatum (Shaw) in acidic temporary ponds at Cape Cod, USA

USGS Publications Warehouse

Portnoy, J.W.

1990-01-01

The relationship between water chemistry and breeding success of spotted salamanders Ambystoma maculatum (Shaw) was examined in temporary woodland ponds on outer Cape Cod, Massachusetts in 1985 and 1986. Most pond waters were dilute (3median coductivity = 57 umhos cm-1 (1 umhos cm-1 = 0?1 mSm-1)), acidic (median pH = 4?82), and highly colored (median = 140 Pt-Co units). Most acidity was due to abundant organic acids. Salamander survival to hatching was over 80% at 8 of 12 ponds monitored. Complete mortality, preceded by gross abnormalities, was observed only among embryos in the most acidic spawning pond (pH 4?3-4?5) in both years. Embryo transfers between ponds and laboratory studies indicated that reduced survival was due to the interaction of low pH with high tannin-lignin concentration. The use of amphibian embryonic survival to indicate acid rain effects is complicated by multiple habitat parameters and should only be attempted in conjunction with long-term population monitoring.

Daily and seasonal variability of pH, dissolved oxygen, temperature, and specific conductance in the Colorado River between the forebay of Glen Canyon, Dam and Lees Ferry, northeastern Arizona, 1998-99

USGS Publications Warehouse

Flynn, Marilyn E.; Hart, Robert J.; Marzolf, G. Richard; Bowser, Carl J.

2001-01-01

The productivity of the trout fishery in the tailwater reach of the Colorado River downstream from Glen Canyon Dam depends on the productivity of lower trophic levels. Photosynthesis and respiration are basic biological processes that control productivity and alter pH and oxygen concentration. During 1998?99, data were collected to aid in the documentation of short- and long-term trends in these basic ecosystem processes in the Glen Canyon reach. Dissolved-oxygen, temperature, and specific-conductance profile data were collected monthly in the forebay of Glen Canyon Dam to document the status of water chemistry in the reservoir. In addition, pH, dissolved-oxygen, temperature, and specific-conductance data were collected at five sites in the Colorado River tailwater of Glen Canyon Dam to document the daily, seasonal, and longitudinal range of variation in water chemistry that could occur annually within the Glen Canyon reach.

Corrosion Behavior and Microstructure Influence of Glass-Ceramic Nuclear Waste Forms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthew Asmussen, R.; Neeway, James J.; Kaspar, Tiffany C.

Glass ceramic waste forms present a potentially viable technology for the long term immobilization and disposal of liquid nuclear wastes. Through control of chemistry during fabrication, such waste forms can have designed secondary crystalline phases within a borosilicate glass matrix. In this work, a glass ceramic containing powellite and oxyapatite secondary phases was tested for its corrosion properties in dilute conditions using single pass flow through testing (SPFT). Three glass ceramic samples were prepared using different cooling rates to produce samples with varying microstructure sizes. In testing at 90 °C in buffered pH 7 and pH 9 solutions, it wasmore » found that increasing pH and decreasing microstructure size (resulting from rapid cooling during fabrication) both led to a reduction in overall corrosion rate. The phases of the glass ceramic were found, using a combination of solutions analysis, SEM and AFM, to corrode preferably in the order of powellite > bulk glass matrix > oxyapatite.« less

Instability of seawater pH in the South China Sea during the mid-late Holocene: Evidence from boron isotopic composition of corals

USGS Publications Warehouse

Liu, Yajing; Liu, W.; Peng, Z.; Xiao, Y.; Wei, G.; Sun, W.; He, J.; Liu, Gaisheng; Chou, C.-L.

2009-01-01

We used positive thermal ionization mass spectrometry (PTIMS) to generate high precision ??11B records in Porites corals of the mid-late Holocene from the South China Sea (SCS). The ??11B values of the Holocene corals vary significantly, ranging from 22.2??? to 25.5???. The paleo-pH records of the SCS, reconstructed from the ??11B data, were not stable as previously thought but show a gradual increase from the Holocene thermal optimal and a sharp decrease to modern values. The latter is likely caused by the large amount of anthropogenic CO2 emissions since the Industrial Revolution but variations of atmospheric pCO2 cannot explain the pH change of the SCS before the Industrial Revolution. We suggest that variations of monsoon intensity during the mid-late Holocene may have driven the sea surface pH increase from the mid to late Holocene. Results of this study indicate that the impact of anthropogenic atmospheric CO2 emissions may have reversed the natural pH trend in the SCS since the mid-Holocene. Such ocean pH records in the current interglacial period can help us better understand the physical and biological controls on ocean pH and possibly predict the long-term impact of climate change on future ocean acidification. ?? 2008 Elsevier Ltd. All rights reserved.

Instability of seawater pH in the South China Sea during the mid-late Holocene: Evidence from boron isotopic composition of corals

NASA Astrophysics Data System (ADS)

Liu, Yi; Liu, Weiguo; Peng, Zicheng; Xiao, Yingkai; Wei, Gangjian; Sun, Weidong; He, Jianfeng; Liu, Guijian; Chou, Chen-Lin

2009-03-01

We used positive thermal ionization mass spectrometry (PTIMS) to generate high precision δ 11B records in Porites corals of the mid-late Holocene from the South China Sea (SCS). The δ 11B values of the Holocene corals vary significantly, ranging from 22.2‰ to 25.5‰. The paleo-pH records of the SCS, reconstructed from the δ 11B data, were not stable as previously thought but show a gradual increase from the Holocene thermal optimal and a sharp decrease to modern values. The latter is likely caused by the large amount of anthropogenic CO 2 emissions since the Industrial Revolution but variations of atmospheric pCO 2 cannot explain the pH change of the SCS before the Industrial Revolution. We suggest that variations of monsoon intensity during the mid-late Holocene may have driven the sea surface pH increase from the mid to late Holocene. Results of this study indicate that the impact of anthropogenic atmospheric CO 2 emissions may have reversed the natural pH trend in the SCS since the mid-Holocene. Such ocean pH records in the current interglacial period can help us better understand the physical and biological controls on ocean pH and possibly predict the long-term impact of climate change on future ocean acidification.

Changes in microbial communities associated with the sea anemone Anemonia viridis in a natural pH gradient.

PubMed

Meron, Dalit; Buia, Maria-Cristina; Fine, Maoz; Banin, Ehud

2013-02-01

Ocean acidification, resulting from rising atmospheric carbon dioxide concentrations, is a pervasive stressor that can affect many marine organisms and their symbionts. Studies which examine the host physiology and microbial communities have shown a variety of responses to the ocean acidification process. Recently, several studies were conducted based on field experiments, which take place in natural CO(2) vents, exposing the host to natural environmental conditions of varying pH. This study examines the sea anemone Anemonia viridis which is found naturally along the pH gradient in Ischia, Italy, with an aim to characterize whether exposure to pH impacts the holobiont. The physiological parameters of A. viridis (Symbiodinium density, protein, and chlorophyll a+c concentration) and its microbial community were monitored. Although reduction in pH was seen to have had an impact on composition and diversity of associated microbial communities, no significant changes were observed in A. viridis physiology, and no microbial stress indicators (i.e., pathogens, antibacterial activity, etc.) were detected. In light of these results, it appears that elevated CO(2) does not have a negative influence on A. viridis that live naturally in the site. This suggests that natural long-term exposure and dynamic diverse microbial communities may contribute to the acclimation process of the host in a changing pH environment.

Roles of calcium and pH in activation of eggs of the medaka fish, Oryzias latipes

PubMed Central

1983-01-01

Unfertilized eggs of the medaka fish (Oryzias latipes) were injected with pH-buffered calcium buffers. Medaka egg activation is accompanied by a transient increase in cytoplasmic free calcium (Gilkey, J. C., L. F. Jaffe, E. B. Ridgway, and G. T. Reynolds, 1978, J. Cell Biol., 76:448-466). The calcium buffer injections demonstrated that (a) the threshold free calcium required to elicit the calcium transient and activate the egg is between 1.7 and 5.1 microM at pH 7.0, well below the 30 microM reached during the transient, and (b) buffers which hold free calcium below threshold prevent activation of the buffered region in subsequently fertilized eggs. Therefore an increase in free calcium is necessary and sufficient to elicit the calcium transient, and the calcium transient is necessary to activate the egg. Further, these results are additional proof that the calcium transient is initiated and propagated through the cytoplasm by a mechanism of calcium- stimulated calcium release. Finally, a normal calcium transient must propagate through the entire cytoplasm to ensure normal development. Unfertilized eggs were injected with pH buffers to produce short-term, localized changes in cytoplasmic pH. The eggs were then fertilized at various times after injection. In other experiments, unfertilized and fertilized eggs were exposed to media containing either NH4Cl or CO2 to produce longer term, global changes in cytoplasmic pH. These treatments neither activated the eggs nor interfered with the normal development of fertilized eggs, suggesting that even if a natural change in cytoplasmic pH is induced by activation, it has no role in medaka egg development. The injected pH buffers altered the rate of propagation of the calcium transient through the cytoplasm, suggesting that the threshold free calcium required to trigger calcium-stimulated calcium release might be pH dependent. The results of injection of pH-buffered calcium buffers support this conjecture: for a tenfold increase in hydrogen ion concentration, free calcium must also be raised tenfold to elicit the calcium transient. PMID:6411737

Infrequent composted biosolids applications affect semi-arid grassland soils and vegetation.

PubMed

Ippolito, J A; Barbarick, K A; Paschke, M W; Brobst, R B

2010-05-01

Monitoring of repeated composted biosolids applications is necessary for improving beneficial reuse program management strategies, because materials will likely be reapplied to the same site at a future point in time. A field trial evaluated a single and a repeated composted biosolids application in terms of long-term (13-14 years) and short-term (2-3 years) effects, respectively, on soil chemistry and plant community in a Colorado semi-arid grassland. Six composted biosolids rates (0, 2.5, 5, 10, 21, 30 Mg ha(-1)) were surface applied in a split-plot design study with treatment (increasing compost rates) as the main factor and co-application time (1991, or 1991 and 2002) as the split factor applications. Short- and long-term treatment effects were evident in 2004 and 2005 for soil 0-8 cm depth pH, EC, NO(3)-N, NH(4)-N, total N, and AB-DTPA soil Cd, Cu, Mo, Zn, P, and Ba. Soil organic matter increases were still evident 13 and 14 years following composted biosolids application. The repeated composted biosolids application increased soil NO(3)-N and NH(4)-N and decreased AB-DTPA extractable Ba as compared to the single composted biosolids application in 2004; differences between short- and long-term applications were less evident in 2005. Increasing biosolids rates resulted in increased native perennial grass cover in 2005. Plant tissue Cu, Mo, Zn, and P concentrations increased, while Ba content decreased depending on specific plant species and year. Overall, the lack of many significant negative effects suggests that short- or long-term composted biosolids application at the rates studied did not adversely affect this semi-arid grassland ecosystem. Published by Elsevier Ltd.

Soil pH determines microbial diversity and composition in the park grass experiment.

PubMed

Zhalnina, Kateryna; Dias, Raquel; de Quadros, Patricia Dörr; Davis-Richardson, Austin; Camargo, Flavio A O; Clark, Ian M; McGrath, Steve P; Hirsch, Penny R; Triplett, Eric W

2015-02-01

The Park Grass experiment (PGE) in the UK has been ongoing since 1856. Its purpose is to study the response of biological communities to the long-term treatments and associated changes in soil parameters, particularly soil pH. In this study, soil samples were collected across pH gradient (pH 3.6-7) and a range of fertilizers (nitrogen as ammonium sulfate, nitrogen as sodium nitrate, phosphorous) to evaluate the effects nutrients have on soil parameters and microbial community structure. Illumina 16S ribosomal RNA (rRNA) amplicon sequencing was used to determine the relative abundances and diversity of bacterial and archaeal taxa. Relationships between treatments, measured soil parameters, and microbial communities were evaluated. Clostridium, Bacteroides, Bradyrhizobium, Mycobacterium, Ruminococcus, Paenibacillus, and Rhodoplanes were the most abundant genera found at the PGE. The main soil parameter that determined microbial composition, diversity, and biomass in the PGE soil was pH. The most probable mechanism of the pH impact on microbial community may include mediation of nutrient availability in the soil. Addition of nitrogen to the PGE plots as ammonium sulfate decreases soil pH through increased nitrification, which causes buildup of soil carbon, and hence increases C/N ratio. Plant species richness and plant productivity did not reveal significant relationships with microbial diversity; however, plant species richness was positively correlated with soil microbial biomass. Plants responded to the nitrogen treatments with an increase in productivity and a decrease in the species richness.

Synthesis, characterization and performance of high energy ball milled meso-scale zero valent iron in Fenton reaction.

PubMed

Ambika, Selvaraj; Devasena, M; Nambi, Indumathi Manivannan

2016-10-01

Understanding contaminant degradation by different sized zero valent iron (ZVI) particles is one important aspect in addressing the long-term stability of these particles in field studies. In this study, meso zero valent iron (mZVI) particles were synthesised in a milling time of 10 h using ball milling technique. The efficacy of mZVI particles for removal of phenol was quantitatively evaluated in comparison with coarse zero valent iron (cZVI) and nano zero valent iron (nZVI) particles. Phenol degradation experiments were carried out in sacrificial batch mode at room temperature independently with cZVI, nZVI and mZVI under varied pH conditions of 3, 4, 6, 7, 8 and 10. Batch experiments substantiating the reactivity of mZVI under unbuffered pH system were also carried out and compared with buffered and poorly buffered pH systems. mZVI particles showed consistent phenol degradation at circum-neutral pH with efficiency of 44%, 67%, and 89% in a span of 5, 10 and 20 min respectively. The dissolved iron species and residual iron formation were also measured as a function of pH. Unbuffered systems at circum-neutral pH produced less residual iron when compared to buffered and poorly buffered systems. At this pH, oxidation of Fe(2+) produced a different oxidant Ferryl ion, which was found to effectively participate in phenol degradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Management of fetal growth restriction using the contraction stress test: a case-control study.

PubMed

Tanaka, Hiroaki; Furuhashi, Fumi H; Toriyabe, Kuniaki; Matsumoto, Takeshi; Magawa, Shoich; Nii, Masafumi; Watanabe, Junko; Tanaka, Kayo; Umekawa, Takashi; Kamimoto, Yuki; Ikeda, Tomoaki

2018-04-18

Fetal growth restriction (FGR) is a concerning health issue. However, studies on FGR management are limited due to its rarity. We aimed to evaluate the efficacy of the contraction stress test (CST) for FGR management. A case-control retrospective study design. Our institute innovated CST in FGR management in 2017. We included women in their 33rd-40th week of pregnancy with a diagnosis of FGR and retrospectively divided them into groups: the CST group (FGR management with CST) and no CST group (FGR management without CST) before and after CST development. Neonatal outcome, pH, and pO 2 of umbilical artery (UA) were compared between the two groups. No significant differences in the rate of birth weight, Apgar score <7 (5 minutes), neonatal death, hospitalization to newborn childhood intensive care unit (NICU), and UA pH were found between groups. Average UA pH was 7.29 ± 0.05 and 7.29 ± 0.04 in the CST and no CST groups, respectively (p = .864). Average UA pO 2 values were 21.1 ± 8.6 and 15.7 ± 5.0 mmHg in the CST and no CST groups, respectively (p = .016), showing significant differences. Neonatal outcomes and UA pH were slightly different between the groups managed with and without CST. However, UA pO 2 values significantly differed between the groups. For FGR management, the use of a CST may allow for early intervention before fetal acidemia and acidosis. For establishing the effects of a CST for FGR management, analysis including several cases and investigation of long-term outcomes of newborn infants is necessary.

Effects of lactic acid bacteria silage inoculation on methane emission and productivity of Holstein Friesian dairy cattle.

PubMed

Ellis, J L; Hindrichsen, I K; Klop, G; Kinley, R D; Milora, N; Bannink, A; Dijkstra, J

2016-09-01

Inoculants of lactic acid bacteria (LAB) are used to improve silage quality and prevent spoilage via increased production of lactic acid and other organic acids and a rapid decline in silage pH. The addition of LAB inoculants to silage has been associated with increases in silage digestibility, dry matter intake (DMI), and milk yield. Given the potential change in silage and rumen fermentation conditions accompanying these silage additives, the aim of this study was to investigate the effect of LAB silage inoculants on DMI, digestibility, milk yield, milk composition, and methane (CH4) production from dairy cows in vivo. Eight mid-lactation Holstein-Friesian dairy cows were grouped into 2 blocks of 4 cows (multiparous and primiparous) and used in a 4×4 double Latin square design with 21-d periods. Methane emissions were measured by indirect calorimetry. Treatments were grass silage (mainly ryegrass) with no inoculant (GS), with a long-term inoculant (applied at harvest; GS+L), with a short-term inoculant (applied 16h before feeding; GS+S), or with both long and short-term inoculants (GS+L+S). All diets consisted of grass silage and concentrate (75:25 on a dry matter basis). The long-term inoculant consisted of a 10:20:70 mixture of Lactobacillus plantarum, Lactococcus lactis, and Lactobacillus buchneri, and the short-term inoculant was a preparation of Lc. lactis. Dry matter intake was not affected by long-term or short-term silage inoculation, nor was dietary neutral detergent fiber or fat digestibility, or N or energy balance. Milk composition (except milk urea) and fat and protein-corrected milk yield were not affected by long- or short-term silage inoculation, nor was milk microbial count. However, milk yield tended to be greater with long-term silage inoculation. Methane expressed in units of grams per day, grams per kilogram of DMI, grams per kilogram of milk, or grams per kilogram of fat and protein-corrected milk yield was not affected by long- or short-term silage inoculation. However, CH4 expressed in units of kilojoules per kilogram of metabolic body weight per day tended to be greater with long-term silage inoculation. Results of this study indicate minimal responses in animal performance to both long- and short-term inoculation of grass silage with LAB. Strain and dose differences as well as different basal silages and ensiling conditions are likely responsible for the lack of significant effects observed here, although positive effects have been observed in other studies. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

An in-situ infection detection sensor coating for urinary catheters

PubMed Central

Milo, Scarlet; Thet, Naing Tun; Liu, Dan; Nzakizwanayo, Jonathan; Jones, Brian V.; Jenkins, A. Toby A.

2016-01-01

We describe a novel infection-responsive coating for urinary catheters that provides a clear visual early warning of Proteus mirabilis infection and subsequent blockage. The crystalline biofilms of P. mirabilis can cause serious complications for patients undergoing long-term bladder catheterisation. Healthy urine is around pH 6, bacterial urease increases urine pH leading to the precipitation of calcium and magnesium deposits from the urine, resulting in dense crystalline biofilms on the catheter surface that blocks urine flow. The coating is a dual layered system in which the lower poly(vinyl alcohol) layer contains the self-quenching dye carboxyfluorescein. This is capped by an upper layer of the pH responsive polymer poly(methyl methacrylate-co-methacrylic acid) (Eudragit S100®). Elevation of urinary pH (>pH 7) dissolves the Eudragit layer, releasing the dye to provide a clear visual warning of impending blockage. Evaluation of prototype coatings using a clinically relevant in vitro bladder model system demonstrated that coatings provide up to 12 h advanced warning of blockage, and are stable both in the absence of infection, and in the presence of species that do not cause catheter blockage. At the present time, there are no effective methods to control these infections or provide warning of impending catheter blockage. PMID:26945183

Growth and physiological responses of beech seedlings to long-term exposure of acid fog.

PubMed

Shigihara, Ado; Matsumoto, Kiyoshi; Sakurai, Naoki; Igawa, Manabu

2008-02-25

Seven-year-old beech seedlings (Fagus crenata) were exposed to simulated acid fog (SAF) at pH 3 or pH 5 (as control) prepared by adding a 2:1:1 mixture (molar ratio) of nitric acid, ammonium sulfate, and sodium chloride to ultrapure water from September 2004 to July 2006 in a mobile fog chamber. In comparison to control seedlings, seedlings from the pH 3 treatment displayed inferior plant height, stem diameter, number of leaves, and dry matter production, but greater leaf area. Furthermore, exposure to SAF induced early falling of leaves with a nearly two-times-greater normalized leaf number index than control. The starch levels in the stems of seedlings of the pH 3 treatment were much lower than those of control at the harvest. The acid fog-induced reduction of the starch accumulation is considered to occur mainly because of fewer leaves during the growth phase. Results of laboratory experiments demonstrate that the amount of base cations leached from the beech leaves increased with decreasing pH of SAF; the leaching amount of calcium ion from the beech was high relative to that of conifers such as fir and cedar. These results imply that chronic acid fog exposure suppresses growth and physiological activity of beech seedlings.

Characterization of metal binding sites onto biochar using rare earth elements as a fingerprint.

PubMed

Pourret, Olivier; Houben, David

2018-02-01

The ability of biochar to immobilize metals relies on the amount of functional groups at its surface but the contribution of each functional groups (e.g. carboxylic, phenolic) to metal bonding is poorly known. Using a new approach based on previous works on rare earth element (REE) interactions with humic substances, we aim at elucidating the relative contribution of these binding sites to metal sorption under various conditions (i.e. pH and ionic strengths, IS). Using batch experiments, REE sorption onto biochar was analyzed from pH 3 to 9 and IS 10 -1 mol/L to 10 -3 mol/L. Rare earth element patterns show a Middle REE (MREE) downward concavity at acidic pH and low ionic strength. These patterns are in good agreement with existing datasets quantifying REE binding with humic substances. Indeed, the MREE downward concavity displayed by REE-biochar complexation pattern compares well with REE patterns with various organic compounds. This similarity in the REE complexation pattern shapes suggests that carboxylic groups are the main binding sites of REE in biochar. Overall, our results indicate that the strength of the metal bonding with biochar increases when pH and IS increase, suggesting that biochar is more efficient for long-term metal immobilization at near neutral pH and high ionic strength.

Spatial changes in acid secretion from isolated stomach tissue using a pH-histamine sensing microarray.

PubMed

Bitziou, Eleni; O'Hare, Danny; Patel, Bhavik Anil

2010-03-01

The acid secretion mechanism can be studied by measuring a series of metabolic markers and neurotransmitters from in vitro isolated tissue. A microelectrode array was used to monitor proton concentration and histamine levels from isolated guinea pig stomach tissue. The device was partially modified using iridium oxide to form a series of pH sensors, whereas unmodified gold microelectrodes were used to measure the level of histamine in the gut. Real-time measurements in the presence of the H2-receptor antagonist ranitidine produced significant decreases in the overall Delta pH response, as expected. Also, a significant variation in the Delta pH response in between pH sensors was observed in the presence of pharmacological treatment due to structural features of the tissue. No significant differences in Delta i(H) were detected in the presence of ranitidine as expected. More significantly, clear variations in Delta pH responses between animals in control conditions and those in the presence of ranitidine was observed highlighting possible variation in parietal cell density and/or variations in tissue activity. These results identify great possibilities in applying these multi-sensing devices as a long-term stable personalised diagnostic tool for pharmacological screening and disease status.

Processes of Personality Development in Adulthood: The TESSERA Framework.

PubMed

Wrzus, Cornelia; Roberts, Brent W

2017-08-01

The current article presents a theoretical framework of the short- and long-term processes underlying personality development throughout adulthood. The newly developed TESSERA framework posits that long-term personality development occurs due to repeated short-term, situational processes. These short-term processes can be generalized as recursive sequence of Triggering situations, Expectancy, States/State expressions, and Reactions (TESSERA). Reflective and associative processes on TESSERA sequences can lead to personality development (i.e., continuity and lasting changes in explicit and implicit personality characteristics and behavioral patterns). We illustrate how the TESSERA framework facilitates a more comprehensive understanding of normative and differential personality development at various ages during the life span. The TESSERA framework extends previous theories by explicitly linking short- and long-term processes of personality development, by addressing different manifestations of personality, and by being applicable to different personality characteristics, for example, behavioral traits, motivational orientations, or life narratives.

Dynamics of human serum albumin studied by acoustic relaxation spectroscopy.

PubMed

Hushcha, T; Kaatze, U; Peytcheva, A

Sonic absorption spectra of solutions of human serum albumin (SA) in water and in aqueous phosphate buffer systems have been measured between 0.2 and 2000 MHz at different temperatures (15-35 degrees C), pH values (1.8-12.3), and protein concentrations (1-40 g/L). Several spectra, indicating relaxation processes in the whole frequency range, have been found. The spectra at neutral pH could be fitted well with an analytical function consisting of the asymptotic high frequency absorption and two relaxation contributions, a Debye-type relaxation term with discrete relaxation time and a term with asymmetric continuous distribution of relaxation times. Both relaxation contributions were observed in water and in buffer solutions and increased with protein concentration. The contribution represented by a Debye-type term is practically independent of temperature and was attributed to cooperative conformational changes of the polypeptide chain featuring a relaxation time of about 400 ns. The distribution of the relaxation times corresponding to the second relaxation contribution was characterized by a short time cutoff, between about 0.02 and 0.4 ns depending on temperature, and a long time tail extending to microseconds. Such relaxation behavior was interpreted in terms of solute-solvent interactions reflecting various hydration layers of HSA molecules. At acid and alkaline pH, an additional Debye-type contribution with relaxation time in the range of 30-100 ns exists. It seems to be due to proton transfer reactions of protein side-chain groups. The kinetic and thermodynamic parameters of these processes have been estimated from these first measurements to indicate the potential of acoustic spectra for the investigation of the elementary kinetics of albumin processes. Copyright 2004 Wiley Periodicals, Inc. Biopolymers, 2004

Application of a fuzzy logic control system for continuous anaerobic digestion of low buffered, acidic energy crops as mono-substrate.

PubMed

Scherer, P; Lehmann, K; Schmidt, O; Demirel, B

2009-02-15

A fuzzy logic control (FLC) system was developed at the Hamburg University of Applied Sciences (HAW Hamburg) for operation of biogas reactors running on energy crops. Three commercially available measuring parameters, namely pH, the methane (CH4) content, and the specific gas production rate (spec. GPR = m(3)/kg VS/day) were included. The objective was to avoid stabilization of pH with use of buffering supplements, like lime or manure. The developed FLC system can cover most of all applications, such as a careful start-up process and a gentle recovery strategy after a severe reactor failure, also enabling a process with a high organic loading rate (OLR) and a low hydraulic retention time (HRT), that is, a high throughput anaerobic digestion process with a stable pH and CH4 content. A precondition for a high load process was the concept of interval feeding, for example, with 8 h of interval. The FLC system was proved to be reliable during the long term fermentation studies over 3 years in one-stage, completely stirred tank reactors (CSTR) with acidic beet silage as mono-input (pH 3.3-3.4). During fermentation of the fodder beet silage (FBS), a stable HRT of 6.0 days with an OLR of up to 15 kg VS/m(3)/day and a volumetric GPR of 9 m(3)/m(3)/day could be reached. The FLC enabled an automatic recovery of the digester after two induced severe reactor failures. In another attempt to prove the feasibility of the FLC, substrate FBS was changed to sugar beet silage (SBS), which had a substantially lower buffering capacity than that of the FBS. With SBS, the FLC accomplished a stable fermentation at a pH level between 6.5 and 6.6, and a volatile fatty acid level (VFA) below 500 mg/L, but the FLC had to interact and to change the substrate dosage permanently. In a further experiment, the reactor temperature was increased from 41 to 50 degrees C. Concomitantly, the specific GPR, pH and CH4 dropped down. Finally, the FLC automatically enabled a complete recovery in 16 days.

[Long-term effects of tillage methods on heavy metal accumulation and availability in purple paddy soil].

PubMed

Chang, Tong-Ju; Cui, Xiao-Qiang; Ruan, Zhen; Zhao, Xiu-Lan

2014-06-01

A long-term experiment, conducted at Southwest University since 1990, was used to evaluate the effect of tillage methods on the total and available contents of heavy metals (Fe, Mn, Cu, Zn, Pb, Cd) in the profile of purple paddy soil and the contents of those metals in root, stem leaf and brown rice. The experiment included five tillage methods: conventional tillage, paddy-upland rotation, no-tillage and fallow in winter, ridge-no-tillage and compartments-no-tillage. The results showed that the total concentrations of Fe, Cu, Zn, Pb and Cd in the soil profile had no significant differences among five treatments, but it was found that total Mn has a significant decline in 0-20 cm under conventional tillage, paddy-upland rotation and no-tillage and fallow in winter compared with ridge-no-tillage and compartments-no-tillage. The availability of Fe, Cu, Zn, Pb and Cd decreased with the increase of soil depth in all treatments, but the availability of Mn was found to be the highest in the 20-40 cm layers except those in the paddy-upland rotation. In the ploughed layer, the contents of available Fe, Mn was the highest in paddy-upland rotation, while the contents of available Zn and Pb was the highest in conventional tillage, but tillage treatments had not significant influence to the contents of available Cu. Correlation analysis showed that available Fe was significantly negatively related to the pH values and significantly negatively related to the organic matter of soils, available Mn was significantly negatively related to the pH values and organic matter of soils, whereas the available Zn was significantly positively related to total Zn. The contents of Fe, Mn in rice root, the contents of Fe, Mn, Cu and Cd in rice straw and Cu in brown rice were higher under paddy-upland rotation, ridge-no-tillage and compartments-no-tillage than those in conventional tillage and no-tillage and fellow in winter. Paddy-upland rotation can significantly lower the migration coefficient value of Cd in brown rice, and the Pb, Cd concentration in brown rice in the treatment of paddy-upland rotation was lower than the upper limit (< 0.2 mg x kg(-1)) of the National Standard for Food Hygiene for Cd concentration. The content of Fe in root was significantly and negatively related with soil pH and significantly and positively related with soil available Fe, the content of Mn in root was significantly negatively related with soil pH and significantly positively related with soil available Mn, the content of Mn in straw was significantly negatively related with soil pH, significantly positively related with soil total Mn and significantly positively related with soil available Mn, the content of Cu in straw and brown rice was significantly negatively related with soil pH, the content of Zn was significant related with soil pH and significant related with soil CEC. The content of Fe in root, Mn in root and straw and Cd in straw was positively related with soil available Fe, Mn and Cd, respectively, but was negatively related with pH in plough layer soil, Zn in straw was also negatively related with plough layer soil pH. From the results as above, it is concluded that different tillage methods can change the values of soil pH, alter the availability of heavy metal in soils, consequently affect uptake of heavy metal by rice. Of the tillage methods, paddy-upland rotation could increase the availability of Fe and Mn, but decrease the availability of Zn, Pb and Cd in purple paddy soils. Paddy-upland rotation can also increase the contents of Fe, Mn in rice root and straw, but decrease Cd content in brown rice, and could reduce the Pb, Cd contents in brown rice in a certain extent, however, attention should be given to long-term paddy-upland rotation cause of leaching of soil surface Mn.

Novel putative pharmacological therapies to protect the right ventricle in pulmonary hypertension: a review of current literature

PubMed Central

Schulz, Rainer; Sliwa, Karen; Schermuly, Ralph Theo; Lecour, Sandrine

2017-01-01

Pulmonary hypertension (PH) is defined by elevated mean pulmonary artery pressure following the pathological remodelling of small pulmonary arteries. An increase in right ventricular (RV) afterload results in RV hypertrophy and RV failure. The pathophysiology of PH, and RV remodelling in particular, is not well understood, thus explaining, at least in part, why current PH therapies have a limited effect. Existing therapies mostly target the pulmonary circulation. Because the remodelled RV fails to support normal cardiac function, patients eventually succumb from RV failure. Developing novel therapies that directly target the function of the RV may therefore benefit patients with PH. In the past decade, several promising studies have investigated novel cardioprotective strategies in experimental models of PH. This review aims to comprehensively discuss and highlight these novel experimental approaches to confer, in the long‐term, greater health benefit in patients with PH. PMID:28099680

Insights in Public Health: Training Today's Students to Meet Tomorrow's Challenges: Undergraduate Public Health at the University of Hawai'i at Manoa.

PubMed

Nelson-Hurwitz, Denise C; Arakaki, Lee-Ann; Uemoto, Maya

2017-03-01

The University of Hawai'i at Manoa (UHM) has long provided public health graduate education. The University's Office of Public Health Studies (OPHS) has recently started to offer a Bachelor of Arts in Public Health (BA PH) degree in response to the growing need for professionals in the health field. The purpose of this paper is to describe how UHM operates the BA PH and how the program complements OPHS's mission and goals. First, we describe the overall scope of the BA PH within OPHS and within UHM. Then we provide examples of how the BA PH program and past undergraduate student projects align with OPHS's four main goals: (1) education, (2) research, (3) service, and (4) program development.

Collaborative study for the establishment of the Ph. Eur. Hepatitis E virus RNA for NAT testing biological reference preparation batch 1.

PubMed

Baylis, S A; Terao, E; Blümel, J; Hanschmann, K-M O

2017-01-01

A new European Pharmacopoeia (Ph. Eur.) biological reference preparation (BRP) had to be established further to the decision to include nucleic acid testing (NAT) for the detection of hepatitis E virus (HEV) RNA in the monograph Human plasma (pooled and treated for virus inactivation) (1646). To this purpose, an international collaborative study was launched in the framework of the Biological Standardisation Programme (BSP) of the European Directorate for the Quality of Medicines & HealthCare (EDQM) and the Commission of the European Union (EU). The study was run in conjunction with the establishment of the 1 st World Health Organization (WHO) international reference panel (IRP) for hepatitis E virus RNA genotypes (8578/13). Twenty-three laboratories used in-house developed and commercially available assays to calibrate a lyophilised candidate BRP prepared from a HEV 3f strain positive human plasma against the 1 st WHO International Standard (IS) for HEV RNA (6329/10). Results from quantitative and qualitative assays were in good agreement and were combined to calculate an assigned potency. Real-time stability studies indicated that the candidate BRP is very stable at lower temperatures and is thus suitable for long-term use. Based on these results, in February 2016, the Ph. Eur. Commission adopted the candidate material as the hepatitis E virus RNA for NAT testing BRP batch 1, with an assigned unitage of 2.1 × 10 4 IU/vial (4.32 log 10 IU/vial).

Metal/Metal Oxide Differential Electrode pH Sensors

NASA Technical Reports Server (NTRS)

West, William; Buehler, Martin; Keymeulen, Didier

2007-01-01

Solid-state electrochemical sensors for measuring the degrees of acidity or alkalinity (in terms of pH values) of liquid solutions are being developed. These sensors are intended to supplant older electrochemical pH sensors that include glass electrode structures and reference solutions. The older sensors are fragile and subject to drift. The present developmental solid-state sensors are more rugged and are expected to be usable in harsh environments. The present sensors are based on a differential-electrode measurement principle. Each sensor includes two electrodes, made of different materials, in equilibrium with the solution of interest.

Carbon nanotube/poly(ethylene-co-vinyl acetate) composite electrode for capillary electrophoretic determination of esculin and esculetin in Cortex Fraxini.

PubMed

Chen, Zhi; Zhang, Luyan; Chen, Gang

2009-10-01

In this report, a novel carbon nanotube/poly(ethylene-co-vinyl acetate) (CNT/EVA) composite electrode was developed for the amperometric detection in CE. The composite electrode was fabricated by packing a mixture of CNTs and melted EVA in a piece of fused-silica capillary under heat. It was coupled with CE for the separation and detection of esculin and esculetin in Cortex Fraxini, a traditional Chinese medicine, to demonstrate its feasibility and performance. Esculin and esculetin have been well separated within 9 min in a 40 cm long capillary at a separation voltage of 12 kV using a 50 mM borate buffer (pH 9.2). The new CNT-based CE detector offered significantly lower detection potentials, yielded enhanced S/N characteristics, and exhibited high resistance to surface fouling and enhanced stability. It showed long-term stability and reproducibility with relative standard deviations of less than 5% for the peak current (n=15) and should also find a wide range of applications in other microfluidic analysis systems.

Method to Biomonitor the Cooked Meat Carcinogen 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine in Dyed Hair by Ultra-Performance Liquid Chromatography-Orbitrap High Resolution Multistage Mass Spectrometry.

PubMed

Guo, Jingshu; Yonemori, Kim; Le Marchand, Loïc; Turesky, Robert J

2015-06-16

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a carcinogenic heterocyclic aromatic amine formed in cooked meat. The use of naturally colored hair containing PhIP can serve as a long-term biomarker of exposure to this carcinogen. However, the measurement of PhIP in dyed hair, a cosmetic treatment commonly used by the adult population, is challenging because the dye process introduces into the hair matrix a complex mixture of chemicals that interferes with the measurement of PhIP. The high-resolution scanning features of the Orbitrap Fusion mass spectrometer were employed to biomonitor PhIP in dyed hair. Because of the complexity of chemicals in the hair dye, the consecutive reaction monitoring of PhIP at the MS(3) scan stage was employed to selectively remove the isobaric interferences. The limit of quantification (LOQ) of PhIP was 84 parts-per-trillion (ppt) employing 50 mg of hair. Calibration curves were generated in dyed hair matrixes and showed good linearity (40-1000 pg PhIP/g hair) with a goodness-of-fit regression value of r(2) > 0.9978. The within-day (between-day) coefficients of variation were 7.7% (17%) and 5.4% (6.1%), respectively, with dyed hair samples spiked with PhIP at 200 and 600 ppt. The levels of PhIP accrued in dyed hair from volunteers on a semicontrolled feeding study who ingested known levels of PhIP were comparable to the levels of PhIP accrued in hair of subjects with natural hair color. The method was successfully employed to measure PhIP in nondyed and dyed hair biospecimens of participants in a case-control study of colorectal adenoma on their regular diet.

Response of soil physicochemical properties and enzyme activities to long-term reclamation of coastal saline soil, Eastern China.

PubMed

Xie, Xuefeng; Pu, Lijie; Wang, Qiqi; Zhu, Ming; Xu, Yan; Zhang, Meng

2017-12-31

Soil enzyme activity during different years of reclamation and land use patterns could indicate changes in soil quality. The objective of this research is to explore the dynamics of 5 soil enzyme activities (dehydrogenase, amylase, urease, acid phosphatase and alkaline phosphatase) involved in C, N, and P cycling and their responses to changes in soil physicochemical properties resulting from long-term reclamation of coastal saline soil. Soil samples from a total of 55 sites were collected from a coastal reclamation area with different years of reclamation (0, 7, 32, 40, 63a) in this study. The results showed that both long-term reclamation and land use patterns have significant effects on soil physicochemical properties and enzyme activities. Compared with the bare flat, soil water content, soil bulk density, pH and electrical conductivity showed a decreasing trend after reclamation, whereas soil organic carbon, total nitrogen and total phosphorus tended to increase. Dehydrogenase, amylase and acid phosphatase activities initially increased and then decreased with increasing years of reclamation, whereas urease and alkaline phosphatase activities were characterized by an increase-decrease-increase trend. Moreover, urease, acid phosphatase and alkaline phosphatase activities exhibited significant differences between coastal saline soil with 63years of reclamation and bare flat, whereas dehydrogenase and amylase activities remained unchanged. Aquaculture ponds showed higher soil water content, pH and EC but lower soil organic carbon, total nitrogen and total phosphorus than rapeseed, broad bean and wheat fields. Rapeseed, broad bean and wheat fields displayed higher urease and alkaline phosphatase activities and lower dehydrogenase, amylase and acid phosphatase activities compared with aquaculture ponds. Redundancy analysis revealed that the soil physicochemical properties explained 74.5% of the variation in soil enzyme activities and that an obvious relationship existed between soil nutrients and soil enzyme activities. These results will assist governmental evaluation of the quality of reclaimed coastal soil. Copyright © 2017 Elsevier B.V. All rights reserved.

Understanding the electron-phonon interaction in polar crystals: Perspective presented by the vibronic theory

NASA Astrophysics Data System (ADS)

Pishtshev, A.; Kristoffel, N.

2017-05-01

We outline our novel results relating to the physics of the electron-TO-phonon (el-TO-ph) interaction in a polar crystal. We explained why the el-TO-ph interaction becomes effectively strong in a ferroelectric, and showed how the electron density redistribution establishes favorable conditions for soft-behavior of the long-wavelength branch of the active TO vibration. In the context of the vibronic theory it has been demonstrated that at the macroscopic level the interaction of electrons with the polar zone-centre TO phonons can be associated with the internal long-range dipole forces. Also we elucidated a methodological issue of how local field effects are incorporated within the vibronic theory. These result provided not only substantial support for the vibronic mechanism of ferroelectricity but also presented direct evidence of equivalence between vibronic and the other lattice dynamics models. The corresponding comparison allowed us to introduce the original parametrization for constants of the vibronic interaction in terms of key material constants. The applicability of the suggested formula has been tested for a wide class of polar materials.

Design of template-stabilized active and earth-abundant oxygen evolution catalysts in acid† †Electronic supplementary information (ESI) available: CVs for unary metal oxides deposition, electrochemical stability at higher current densities for unary metal oxides at pH 2.5, EDS maps for CoMnOx and CoPbOx, STEM images and PXRD of CoMnOx and CoFePbOx, high-resolution XPS of Fe 2p for CoFePbOx, Pourbaix diagrams (of Mn, Co, Pb, and Fe), and elemental analysis. See DOI: 10.1039/c7sc01239j Click here for additional data file.

PubMed Central

Huynh, Michael; Ozel, Tuncay; Liu, Chong; Lau, Eric C.

2017-01-01

Oxygen evolution reaction (OER) catalysts that are earth-abundant and are active and stable in acid are unknown. Active catalysts derived from Co and Ni oxides dissolve at low pH, whereas acid stable systems such as Mn oxides (MnOx) display poor OER activity. We now demonstrate a rational approach for the design of earth-abundant catalysts that are stable and active in acid by treating activity and stability as decoupled elements of mixed metal oxides. Manganese serves as a stabilizing structural element for catalytically active Co centers in CoMnOx films. In acidic solutions (pH 2.5), CoMnOx exhibits the OER activity of electrodeposited Co oxide (CoOx) with a Tafel slope of 70–80 mV per decade while also retaining the long-term acid stability of MnOx films for OER at 0.1 mA cm–2. Driving OER at greater current densities in this system is not viable because at high anodic potentials, Mn oxides convert to and dissolve as permanganate. However, by exploiting the decoupled design of the catalyst, the stabilizing structural element may be optimized independently of the Co active sites. By screening potential–pH diagrams, we replaced Mn with Pb to prepare CoFePbOx films that maintained the high OER activity of CoOx at pH 2.5 while exhibiting long-term acid stability at higher current densities (at 1 mA cm–2 for over 50 h at pH 2.0). Under these acidic conditions, CoFePbOx exhibits OER activity that approaches noble metal oxides, thus establishing the viability of decoupling functionality in mixed metal catalysts for designing active, acid-stable, and earth-abundant OER catalysts. PMID:29163926

An idealised study for the long term evolution of crescentic bars

NASA Astrophysics Data System (ADS)

Chen, W. L.; Dodd, N.; Tiessen, M. C. H.; Calvete, D.

2018-01-01

An idealised study that identifies the mechanisms in the long term evolution of crescentic bar systems in nature is presented. Growth to finite amplitude (i.e., equilibration, sometimes referred to as saturation) and higher harmonic interaction are hypothesised to be the leading nonlinear effects in long-term evolution of these systems. These nonlinear effects are added to a linear stability model and used to predict crescentic bar development along a beach in Duck, North Carolina (USA) over a 2-month period. The equilibration prolongs the development of bed patterns, thus allowing the long term evolution. Higher harmonic interaction enables the amplitude to be transferred from longer to shorter lengthscales, which leads to the dominance of shorter lengthscales in latter post-storm stages, as observed at Duck. The comparison with observations indicates the importance of higher harmonic interaction in the development of nearshore crescentic bar systems in nature. Additionally, it is concluded that these nonlinear effects should be included in models simulating the development of different bed patterns, and that this points a way forward for long-term morphodynamical modelling in general.

(p-ClPhSe)2 stimulates carbohydrate metabolism and reverses the metabolic alterations induced by high fructose load in rats.

PubMed

Quines, Caroline B; Rosa, Suzan G; Chagas, Pietro M; Velasquez, Daniela; Prado, Vinicius C; Nogueira, Cristina W

2017-09-01

The modern life leads to excess consumption of food rich in fructose; however, the long-term changes in carbohydrate and lipid metabolism could lead to metabolic dysfunction in humans. The present study evaluated the in vitro insulin-mimetic action of p-chloro-diphenyl diselenide (p-ClPhSe) 2 . The second aim of this study was to investigate if (p-ClPhSe) 2 reverses metabolic dysfunction induced by fructose load in Wistar rats. The insulin-mimetic action of (p-ClPhSe) 2  at concentrations of 50 and 100 μM was determined in slices of rat skeletal muscle. (p-ClPhSe) 2  at a concentration of 50 μM stimulated the glucose uptake by 40% in skeletal muscle. A dose-response curve revealed that (p-ClPhSe) 2  at a dose of 25 mg/kg reduced (∼20%) glycemia in rats treated with fructose (5 g/kg, i.g.). The administration of fructose impaired the liver homeostasis and (p-ClPhSe) 2 (25 mg/kg) protected against the increase (∼25%) in the G-6-Pase and isocitrate dehydrogenase activities and reduced the triglyceride content (∼25%) in the liver. (p-ClPhSe) 2 regulated the liver homeostasis by stimulating hexokinase activity (∼27%), regulating the TCA cycle activity (increased the ATP and citrate synthase activity (∼15%)) and increasing the glycogen levels (∼67%). In conclusion, (p-ClPhSe) 2 stimulated carbohydrate metabolism and reversed metabolic dysfunction in rats fed with fructose. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Short-Term and Long-Term Effects of AWE Feedback on ESL Students' Development of Grammatical Accuracy

ERIC Educational Resources Information Center

Li, Zhi; Feng, Hui-Hsien; Saricaoglu, Aysel

2017-01-01

This classroom-based study employs a mixed-methods approach to exploring both short-term and long-term effects of Criterion feedback on ESL students' development of grammatical accuracy. The results of multilevel growth modeling indicate that Criterion feedback helps students in both intermediate-high and advanced-low levels reduce errors in eight…

Tracking Trends in Fractional Forest Cover Change using Long Term Data from AVHRR and MODIS

NASA Astrophysics Data System (ADS)

Kim, D. H.; DiMiceli, C.; Sohlberg, R. A.; Hansen, M.; Carroll, M.; Kelly, M.; Townshend, J. R.

2014-12-01

Tree cover affects terrestrial energy and water exchanges, photosynthesis and transpiration, net primary production, and carbon and nutrient fluxes. Accurate and long-term continuous observation of tree cover change is critical for the study of the gradual ecosystem change. Tree cover is most commonly inferred from categorical maps which may inadequately represent within-class heterogeneity for many analyses. Alternatively, Vegetation Continuous Fields data measures fractions or proportions of pixel area. Recent development in remote sensing data processing and cross sensor calibration techniques enabled the continuous, long-term observations such as Land Long-Term Data Records. Such data products and their surface reflectance data have enhanced the possibilities for long term Vegetation Continuous Fields data, thus enabling the estimation of long term trend of fractional forest cover change. In this presentation, we will summarize the progress in algorithm development including automation of training selection for deciduous and evergreen forest, the preliminary results, and its future applications to relate trends in fractional forest cover change and environmental change.

Studying frequency processing of the brain to enhance long-term memory and develop a human brain protocol.

PubMed

Friedrich, Wernher; Du, Shengzhi; Balt, Karlien

2015-01-01

The temporal lobe in conjunction with the hippocampus is responsible for memory processing. The gamma wave is involved with this process. To develop a human brain protocol, a better understanding of the relationship between gamma and long-term memory is vital. A more comprehensive understanding of the human brain and specific analogue waves it uses will support the development of a human brain protocol. Fifty-eight participants aged between 6 and 60 years participated in long-term memory experiments. It is envisaged that the brain could be stimulated through binaural beats (sound frequency) at 40 Hz (gamma) to enhance long-term memory capacity. EEG recordings have been transformed to sound and then to an information standard, namely ASCII. Statistical analysis showed a proportional relationship between long-term memory and gamma activity. Results from EEG recordings indicate a pattern. The pattern was obtained through the de-codification of an EEG recording to sound and then to ASCII. Stimulation of gamma should enhance long term memory capacity. More research is required to unlock the human brains' protocol key. This key will enable the processing of information directly to and from human memory via gamma, the hippocampus and the temporal lobe.

Fully Implantable Deep Brain Stimulation System with Wireless Power Transmission for Long-term Use in Rodent Models of Parkinson's Disease.

PubMed

Heo, Man Seung; Moon, Hyun Seok; Kim, Hee Chan; Park, Hyung Woo; Lim, Young Hoon; Paek, Sun Ha

2015-03-01

The purpose of this study to develop new deep-brain stimulation system for long-term use in animals, in order to develop a variety of neural prostheses. Our system has two distinguished features, which are the fully implanted system having wearable wireless power transfer and ability to change the parameter of stimulus parameter. It is useful for obtaining a variety of data from a long-term experiment. To validate our system, we performed pre-clinical test in Parkinson's disease-rat models for 4 weeks. Through the in vivo test, we observed the possibility of not only long-term implantation and stability, but also free movement of animals. We confirmed that the electrical stimulation neither caused any side effect nor damaged the electrodes. We proved possibility of our system to conduct the long-term pre-clinical test in variety of parameter, which is available for development of neural prostheses.

Capillary electrochromatographic separation of peptides using a macrocyclic polyamine for molecular recognition.

PubMed

Chen, Tse-Hsien; Misra, Tarun Kumar; Liu, Chuen-Ying

2008-04-01

A macrocyclic polyamine, 1,5,9,13,17,21,25,29-octaazacyclodotriacontane ([32]ane-N(8)), in the bonded phase was employed as a molecular receptor for CEC separation of oligopeptides. Parameters affecting the performance of the separations were considered. Baseline separation for the mixture of angiotensin I, angiotensin II, [Sar(1), Thr(8)]-angiotensin II, beta-casomorphin bovine, beta-casomorphin human, oxytocin acetate, tocinoic acid, vasopressin, and FMRF amide could be achieved using phosphate buffer (30 mM, pH 7) as the mobile phase. Column efficiency with average theoretical plate numbers of 69 000 plates/m and RSDs of <1% (n = 6) was achieved. [Met(5)]-enkephalin and [Leu(5)]-enkephalin, which have identical pI values and similar masses could be completely separated using acetate buffer (30 mM) with pH gradient (pH 3 inlet side and pH 4 outlet side). The results suggest that the mechanism for the peptide separation was mediated by a combination of electrophoretic migration and chromatographic retention involving anion coordination and anion exchange. After long-term use, the deviation of the EOF of the column after more than 600 injections was still within 6.0% of that for a freshly prepared column.

Long-term isolation and local adaptation in Palau's Nikko Bay help corals thrive in acidic waters

NASA Astrophysics Data System (ADS)

Golbuu, Yimnang; Gouezo, Marine; Kurihara, Haruko; Rehm, Lincoln; Wolanski, Eric

2016-09-01

The reefs in Palau's Nikko Bay live in seawater with low pH that is similar to conditions predicted for 2100 because of ocean acidification. Nevertheless, the reefs at Nikko Bay have high coral cover and high diversity. We hypothesize that the low-pH environment in Nikko Bay is caused by low flushing rates, which causes long-term isolation and local adaptation. To test this hypothesis, we modeled the water circulation in and around Nikko Bay. Model results show that average residence time is 71 d, which is ten times the residence time on fore-reef habitats. The long residence time restricts the exchange of coral larvae in the bay with adjacent reefs, allowing persistent selection for tolerant traits and local adaptation. The corals in Nikko Bay are also more susceptible to local pollution because the waters are poorly flushed. Therefore, local management must focus on minimizing human impacts such as dredging, overfishing and pollution in the bay, which would compromise the condition of the corals that have already adapted to low-pH conditions.

Levels of Interference in Long and Short-Term Memory Differentially Modulate Non-REM and REM Sleep

PubMed Central

Fraize, Nicolas; Carponcy, Julien; Joseph, Mickaël Antoine; Comte, Jean-Christophe; Luppi, Pierre-Hervé; Libourel, Paul-Antoine; Salin, Paul-Antoine; Malleret, Gaël; Parmentier, Régis

2016-01-01

Study Objectives: It is commonly accepted that sleep is beneficial to memory processes, but it is still unclear if this benefit originates from improved memory consolidation or enhanced information processing. It has thus been proposed that sleep may also promote forgetting of undesirable and non-essential memories, a process required for optimization of cognitive resources. We tested the hypothesis that non-rapid eye movement sleep (NREMS) promotes forgetting of irrelevant information, more specifically when processing information in working memory (WM), while REM sleep (REMS) facilitates the consolidation of important information. Methods: We recorded sleep patterns of rats trained in a radial maze in three different tasks engaging either the long-term or short-term storage of information, as well as a gradual level of interference. Results: We observed a transient increase in REMS amount on the day the animal learned the rule of a long-term/reference memory task (RM), and, in contrast, a positive correlation between the performance of rats trained in a WM task involving an important processing of interference and the amount of NREMS or slow wave activity. Various oscillatory events were also differentially modulated by the type of training involved. Notably, NREMS spindles and REMS rapid theta increase with RM training, while sharp-wave ripples increase with all types of training. Conclusions: These results suggest that REMS, but also rapid oscillations occurring during NREMS would be specifically implicated in the long-term memory in RM, whereas NREMS and slow oscillations could be involved in the forgetting of irrelevant information required for WM. Citation: Fraize N, Carponcy J, Joseph MA, Comte JC, Luppi PH, Libourel PA, Salin PA, Malleret G, Parmentier R. Levels of interference in long and short-term memory differentially modulate non-REM and REM sleep. SLEEP 2016;39(12):2173–2188. PMID:27748246

Wastewater-Enhanced Microbial Corrosion of Concrete Sewers.

PubMed

Jiang, Guangming; Zhou, Mi; Chiu, Tsz Ho; Sun, Xiaoyan; Keller, Jurg; Bond, Philip L

2016-08-02

Microbial corrosion of concrete in sewers is known to be caused by hydrogen sulfide, although the role of wastewater in regulating the corrosion processes is poorly understood. Flooding and splashing of wastewater in sewers periodically inoculates the concrete surface in sewer pipes. No study has systematically investigated the impacts of wastewater inoculation on the corrosion of concrete in sewers. This study investigated the development of the microbial community, sulfide uptake activity, and the change of the concrete properties for coupons subjected to periodic wastewater inoculation. The concrete coupons were exposed to different levels of hydrogen sulfide under well-controlled conditions in laboratory-scale corrosion chambers simulating real sewers. It was evident that the periodic inoculation induced higher corrosion losses of the concrete in comparison to noninoculated coupons. Instantaneous measurements such as surface pH did not reflect the cumulative corrosion losses caused by long-term microbial activity. Analysis of the long-term profiles of the sulfide uptake rate using a Gompertz model supported the enhanced corrosion activity and greater corrosion loss. The enhanced corrosion rate was due to the higher sulfide uptake rates induced by wastewater inoculation, although the increasing trend of sulfide uptake rates was slower with wastewater. Increased diversity in the corrosion-layer microbial communities was detected when the corrosion rates were higher. This coincided with the environmental conditions of increased levels of gaseous H2S and the concrete type.

Long-term use of short- and long-acting nitrates in stable angina pectoris.

PubMed

Kosmicki, Marek Antoni

2009-05-01

Long-acting nitrates are effective antianginal drugs during initial treatment. However, their therapeutic value is compromised by the rapid development of tolerance during sustained therapy, which means that their clinical efficacy is decreased during long-term use. Sublingual nitroglycerin (NTG), a short-acting nitrate, is suitable for the immediate relief of angina. In patients with stable angina treated with oral long-acting nitrates, NTG maintains its full anti-ischemic effect both after initial oral ingestion and after intermittent long-term oral administration. However, NTG attenuates this effect during continuous treatment, when tolerance to oral nitrates occurs, and this is called cross-tolerance. In stable angina long-acting nitrates are considered third-line therapy because a nitrate-free interval is required to avoid the development of tolerance. Nitrates vary in their potential to induce the development of tolerance. During long-lasting nitrate therapy, except pentaerythritol tetranitrate (PETN), one can observe the development of reactive oxygen species (ROS) inside the muscular cell of a vessel wall, and these bind with nitric oxide (NO). This leads to decreased NO activity, thus, nitrate tolerance. PETN has no tendency to form ROS, and therefore during long-term PETN therapy, there is probably no tolerance or cross-tolerance, as during treatment with other nitrates.

Perturbation theory of structure in classical liquid mixtures: Application to metallic systems near phase separation. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Henderson, R. L.

1974-01-01

The partial structure factors of classical simple liquid mixtures near phase separation are dicussed. The theory is developed for particles interacting through pair potentials, and is thus appropriate both to insulating fluids, and also to metallic systems if these may be described by an effective ion-ion pair interaction. The motivation arose from consideration of metallic liquid mixtures, in which resistive anomalies have been observed near phase separation. A mean field theory correction appropriate to 3 pair potential for the effects of correlated motions in the reference fluid is studied. The work is cast in terms of functions which are closely related to the direct correlation functions of Ornstein and Zernike. The results are qualitatively in accord with physical expectations. Quantitative agreement with experiment seems to turn on the selection of the hard core reference potential in terms of the metallic effective pair potential. It is suggested that the present effective pair potentials are perhaps not properly used to calculate the metallic structure factors at long wavelength.