bluuebunny/crossref_metadata_2025 huggingface dataset:
In Situ Bioremediation of Perchlorate in Vadose Zone Soil Using Gaseous Electron Donors: Microcosm Treatability Study
Authors: Cai Hua , Eramo Alessia G. , Evans Patrick J. , Fricke Rodney , Brennan Rachel A.
Published: April 2010

A series of microcosm experiments were performed to determine the effectiveness of various gaseous electron donors (including hydrogen, 1‐hexene, ethyl acetate, and liquefied petroleum gas [LPG]) for supporting biological perchlorate reduction under different electron donor concentrations and soil moistures. Under high soil moisture (16% w/w) conditions, complete or partial perchlorate degradation was achieved with all of the tested electron donors, except for ethyl acetate. Hydrogen was the most promising of the tested electron donors, achieving complete perchlorate degradation with first‐order rate constants ranging from 0.13 to 0.20 day−1 and reducing concentrations to non‐detectable levels within 35 to 42 days. The LPG and 1‐hexene each promoted partial perchlorate reduction, with average first‐order rate constants of 0.05 and 0.11 day−1, respectively. Although significant perchlorate reduction was observed with as little as 13% moisture, the moisture content for complete perchlorate degradation in this particular soil was determined to be 17%.
Strategies for the Startup of Methanogenic Inverse Fluidized‐Bed Reactors Using Colonized Particles
Authors: Alvarado‐Lassman A. , Sandoval‐Ramos A. , Flores‐Altamirano M.G. , Vallejo‐Cantú N.A. , Méndez‐Contreras J.M.
Published: April 2010

One of the inconveniences in the startup of methanogenic inverse fluidized‐bed reactors (IFBRs) is the long period required for biofilm formation and stabilization of the system. Previous researchers have preferred to start up in batch mode to shorten stabilization times. Much less work has been done with continuous‐mode startup for the IFBR configuration of reactors. In this study, we prepared two IFBRs with similar characteristics to compare startup times for batch‐ and continuous‐operation modes. The reactors were inoculated with a small quantity of colonized particles and run for a period of 3 months, to establish the optimal startup strategy using synthetic media as a substrate (glucose as a source of carbon). After the startup stage, the continuous‐ and batch‐mode reactors removed more than 80% of the chemical oxygen demand (COD) in 51 and 60 days of operation, respectively; however, at the end of the experiments, the continuous‐mode reactor had more biomass attached to the support media than the batch‐mode reactor. Both reactors developed fully covered support media, but only the continuous‐mode reactor had methane yields close to the theoretical value that is typical of stable reactors. Then, a combined startup strategy was proposed, with industrial wastewater as the substrate, using a sequence of batch cycles followed by continuous operation, which allows stable operation at an organic loading rate of 20 g COD/L·d in 15 days. Using a fraction of colonized support as an inoculum presents advantages, with respect to previously reported strategies.
Full‐Scale Removal of Arsenate and Chromate from Water Using a Limestone and Ochreous Sludge Mixture as a Low‐Cost Sorbent Material
Authors: Cederkvist Karin , Holm Peter E. , Jensen Marina B.
Published: April 2010

The oxyanions arsenate (AsO43−) and chromate (CrO42−) are major freshwater contaminants. Arsenate is a problematic contaminant in drinking water reservoirs, and chromate limits the use of urban stormwater runoff. High‐capacity, low‐cost, energy‐efficient treatment technologies are required for the removal of these toxic anions from freshwater sources. Using a 50‐m‐long dual porosity filter, with limestone as filtering grains, treating stormwater runoff from Copenhagen, Denmark, we tested if addition of the waste product ochreous sludge can improve the removal of arsenate (As) and chromate (Cr) without compromising the calcite's removal affinity towards metallic cations. Upon on‐site embedding of the ochreous sludge, removal of arsenic and chromium was improved greatly, and copper (Cu) removal remained high. Steady‐state effluent concentrations were reduced from 31 to 2 µg As/L, 127 to 1.5 µg Cr/L, and 18 to 9.6 µg Cu/L upon mixing with the ochreous sludge. Limestone‐ochreous sludge represents a promising low‐cost oxyanion and cation sorbent operating at neutral pH without pH control.
Implications of Aerated Stabilization Basin Dredging on Potential Effluent Toxicity to Fish
Authors: Mahmood Talat , Kovacs Tibor , Gibbons Sharon , Paradis Jean‐Claude
Published: April 2010

Benthal solids accumulated in aerated stabilization basins (ASBs) must be dredged to regain treatment capacity. While dredging restores treatment performance, it has been associated occasionally with the failure to meet regulatory effluent toxicity limits at the time of dredging. A first study of its kind was undertaken to investigate the implications of ASB dredging on potential effluent toxicity to fish. The study showed that benthal solid slurry removed from the quiescent zone of an ASB with a hydraulic dredge was toxic to rainbow trout with a 96‐hour median lethal concentration (LC50) of 2.2%. The high ammonia concentration in the sample was the main cause of fish mortality. Hydrogen sulfide and resin and fatty acids also were present in the dredged material at concentrations that could cause fish mortality. These findings have led to best management practices that can be used to mitigate or eliminate fish toxicity issues during dredging operations.
Data Reconciliation for Wastewater Treatment Plant Simulation Studies—Planning for High‐Quality Data and Typical Sources of Errors
Authors: Rieger Leiv , Takács Imre , Villez Kris , Siegrist Hansruedi , Lessard Paul , Vanrolleghem Peter A. , Comeau Yves
Published: April 2010

Model results are only as good as the data fed as input or used for calibration. Data reconciliation for wastewater treatment modeling is a demanding task, and standardized approaches are lacking. This paper suggests a procedure to obtain high‐quality data sets for model‐based studies. The proposed approach starts with the collection of existing historical data, followed by the planning of additional measurements for reliability checks, a data reconciliation step, and it ends with an intensive measuring campaign. With the suggested method, it should be possible to detect, isolate, and finally identify systematic measurement errors leading to verified and qualitative data sets. To allow mass balances to be calculated or other reliability checks to be applied, few additional measurements must be introduced in addition to routine measurements. The intensive measurement campaign should be started only after all mass balances applied to the historical data are closed or the faults have been detected, isolated, and identified. In addition to the procedure itself, an overview of typical sources of errors is given.
Model‐Based Design of Sequencing Batch Reactor for Removal of Biodegradable Organics and Nitrogen
Authors: Velmurugan S. , Clarkson William W. , Veenstra John N.
Published: April 2010

The process design of sequencing batch reactors (SBR) based on mathematical modeling is complex because of the unsteady nature of the process and the large number of kinetic and stoichiometric parameters involved. This paper proposes a model‐based design methodology that uses a mathematical model with fewer parameters for removal of organic and nitrogen substrates in the SBR. The resulting mathematical model has been calibrated and validated before its use in model‐based design. The data for model calibration and validation were obtained from the operation of a full‐scale 836 m3/h (5.3 mgd) SBR system at the City of Tahlequah, Oklahoma. A calibration methodology also was presented to determine unknown kinetic and stoichiometric parameters using an optimization technique called simulated annealing. Model‐based design reduced the total volume of the reactor by approximately 11% from the existing design. It also eliminated 0.92 hours of cycle time and 1.07 hours of aeration time per cycle, which would result in a total energy savings of $11,640 per year for the 836 m3/h (5.3 mgd) SBR system.
Treatment Shaft for Combined Sewer Overflow Detention
Authors: Wright Steven J. , Ghalib Saad , Eloubaidy Aziz
Published: April 2010

A deep, large‐diameter underground shaft to provide detention storage for combined sewer overflow control may be advantageous in urban environments, where space limitations require solutions with a small footprint. An underflow baffle wall is provided at the center of the treatment shaft to prevent short‐circuiting of the flow. An additional objective is to maintain low headlosses through the structure. A physical model study was conducted to determine the effect of the bottom elevation of the baffle wall on the headloss and breakthrough curve for dye injected to the inflow. It was found that there is a considerable range of elevations for which the structure behaves acceptably in providing adequate contact time for disinfectant while maintaining small headlosses.
Digital Governance and Institutional Change: Examining the Role of E‐Government in China's Coal Sector
Authors: Schlæger Jesper
Published: April 2010

Coal allocation in China is a seminal case of e‐government in the political economy. The empirical phenomenon of market supporting e‐government has not been systematically analysed. By developing and applying a digital governance model this article examines institutional change in a case of coal allocation reform in China. The case shows how the central state used e‐government to get rid of planning overload. Coal allocation meetings were abolished in favour of an ecology of online market solutions. The findings suggest that further research on Chinese e‐government would benefit from attention to the role of e‐government in the political economy.
Government 2.0? Technology, Trust and Collaboration in the UAE Public Sector
Authors: Salem Fadi , Jarrar Yasar
Published: April 2010

Increased use of the Internet and related technologies in government seems to hold out promise for a collaborative governance model, derived from cross‐agency information and knowledge sharing, but many governments struggle to attain this goal. Over the past decade, many local and federal government entities in the United Arab Emirates witnessed a shift from the traditional, hierarchical ‘silos mode’ of governance into a ‘competitive mode,’ heavily influenced by ‘New Public Management’ approaches. Although competition has had a relatively positive impact on government efficiency, there is evidence that it has increased institutional and policy complexity, reduced levels of trust and decreased knowledge sharing in government, thereby reinforcing information silos and hindering collaboration and cross‐government innovations. This article reports a national survey of UAE government employees in federal and local government institutions which found that ‘technology,’ ‘leadership’ and ‘trust’ are perceived as the top three interconnected enablers of collaboration in the UAE government. The article concludes that there is now a possibility to move towards a more collaborative mode in governance, using technological innovations to bring down the cost of social transactions in government, with three key prerequisites: fostering a comfortable level of ‘political trust’ between society and government, achieving a threshold of social acceptance of technology ('technological trust') within the public sector and reforming the ‘social trust’ dynamics in society.
Transparency of Public Decision‐Making: Towards Trust in Local Government?
Authors: Grimmelikhuijsen Stephan G.
Published: April 2010

Online minutes of local councils offer the opportunity to look behind the scenes of local government decision‐making. Will this transparency, as promised, lead to higher levels of trust? This issue was investigated by conducting an experiment comparing participants who did not access the available information, people who were only allowed restricted information about the minutes, and those who were shown the full minutes of the local council. Results indicated that people exposed to more information were significantly more negative regarding perceived competence of the council compared to those who did not access the available information. Additionally, participants who received only restricted information about the minutes thought the council was less honest compared to those who did not read them. The relationship between transparency and trust is influenced partly by the perceived credibility of the message on the website. Also, knowledge about the decision‐making process appears to shift judgment criteria. People well informed about the process are inclined to base their judgment of perceived competence on this knowledge and less on message credibility. A theoretical explanation for the negative effect of transparency of public decision‐making is sought in the expectations of the public versus the reality. A lower perceived competence by those who had access to full information might be explained by a gap between public expectations of rational decision‐making and the reality of the chaos involved in public decision‐making exposed through transparency.
The influence of weather conditions on mid-field ponds situated in a reclaimed area in Sępopolska Plain
Authors: Cymes Ireneusz , Cymes Iwona , Dragańska Ewa , Szymczyk Sławomir
Published: April 2010

The influence of weather conditions on mid-field ponds situated in a reclaimed area in Sępopolska Plain

The investigations were conducted in northeastern Poland near Lidzbark Warmiński (54° 08" N, 20° 36" E). Five mid-field ponds situated on grasslands were chosen: four of them were dredged and deepened, and one of them remained as a natural reservoir. The aim of this paper was to assess the influence of weather conditions on the quantity and quality of water in mid-field ponds situated in agricultural areas. It was found that the quantity of water in mid-field ponds was related much more to the air temperature, which was responsible for either water evaporation or snow melting, rather than to the amount of precipitation. The reduction in the volume of water stored in the ponds during very dry years had a negative influence on its quality. During the observation period, the dredged ponds were characterized by permanent water tables, whereas the natural reservoir dried out in very dry years. Atmospheric conditions influenced the concentrations of ammonium nitrogen and calcium and chlorine ions in the studied water bodies. The volume of water retained in mid-field ponds influenced the concentrations of phosphorus and sulphates. Increased precipitation sums caused lower water pH; however in warmer periods, at increased pH and CODCr, a decrease in dissolved oxygen was noted. It was revealed that increases in precipitation sums during the year caused increases in the load of mineral nitrogen and calcium and magnesium ions in pond water.
Changes in the structure of phytoplankton in the lowest part of the Cybina River and the Maltański Reservoir
Authors: Kozak Anna
Published: April 2010

The floristic composition, abundance, and biomass of phytoplankton in the Cybina River and the Maltański Reservoir were examined from April to October 2005. The analysis of the phytoplankton in the samples revealed statistically significant differences in both composition and abundance. The maximum abundance (39.2 × 103 ind. cm-3) and biomass (56.8 μg cm-3) of phytoplankton was noted in July 2005 at the outlet from the Maltański Reservoir. The lowest phytoplankton density was most often noted at the site located at the inlet of the Cybina River into the Maltański Reservoir. The quantitative and qualitative compositions of the phytoplankton varied at different sites. The highest taxonomical similarity was noted among the samples collected in the reservoir and at the outflow from it.
The in situ influence of Ceratophyllum demersum on a phytoplankton assemblage
Authors: Pełechata Aleksandra , Pełechaty Mariusz
Published: April 2010

The in situ influence of Ceratophyllum demersum on a phytoplankton assemblage

The aim of this work was to present a quantitative and qualitative analysis of a phytoplankton assemblage under the influence of Ceratophyllum demersum L. during a two-year field study. Literature data obtained under laboratory conditions indicate that C. demersum may cause a decrease in the blue-green algae biomass, which is considered to be evidence of the significance of allelopathy. The observations reported in the current paper indicated that there was no clear effect on cyanoprokaryota whereas decreases in the quantity of Cryptophyta, Dinophyta, Chlorophyta, and Chrysophyceae are noted.
Factors which shape the load of water ecosystems with mineral nitrogen runoffs in rural areas
Authors: Szymczyk Sławomir
Published: April 2010

The present study of factors which affect the load of water ecosystems with mineral nitrogen compounds (N-NH4 and N-NO3) was conducted in the Olsztyn Lake District and covered the time period from 1992 to 1999. Three capture basins were investigated: agricultural drained with a drain network, agricultural drained with a drainage ditch, and agricultural-forested drained with scattered drains and ditches. It was found that the concentration and load of mineral forms of nitrogen in waters running off from rural areas were closely dependent on meteorological conditions, the kind of artificial drainage system in use, and the type of land use in the catchment area. In waters carried away through the drainage systems, average annual concentrations of N-NH4 ranged from 0.16 mg dm-3 (the agricultural capture basin drained with ditches) to 1.09 mg dm-3 (the agricultural catchment drained with a network of drains); the amounts of N-NO3 ranged from 0.29 mg dm-3 (the agricultural-forested catchment) to 8.06 mg dm-3 (the agricultural catchment drained with a network of drains). It was also observed that a larger share of arable lands in the land use structure in a given catchment caused an increase in the load of N-NO3 determined in drained waters. In addition, it was confirmed that the amounts of mineral nitrogen carried away with drained waters annually varied from 12.78 kg N (6.7 kg N on average) per 1 ha of an agriculturally used catchment, of which N-NO3 was a dominant form (12.23 kg).
Peculiarities of macrozoobenthos in the offshore zone of a small artificial post-gravel pit reservoir
Authors: Żbikowski Janusz , Kobak Jarosław
Published: April 2010

The offshore macrozoobenthos and selected environmental parameters were studied in a small artificial reservoir, created through sand and gravel extraction. The results are rather surprising. Despite the shallow depth and good wind exposure of the reservoir, a thermal and oxygen stratification developed in the summer, causing hypoxic conditions near the bottom, even though the organic matter content in the sediments was <5%. Furthermore, despite the high fish abundance, chaoborids prevailed in zoobenthos, while Tanytarsus sp. and Chironomus sp. co-dominated among chironomids. This study attempts to explain the observed phenomena, though the presented hypotheses still need further confirmation.
Using macrophytes as trophic state indicators in upland river waters: a case study of the Czarna Maleniecka River
Authors: Kopeć Dominik , Dałkowski Radosław , Urbaniak Paweł
Published: April 2010

The study was conducted on the upper reach of the Czarna Maleniecka River from Furmanów to the ford at Piekło. Nine sampling sites were selected along this 20-km section. Detailed studies of flora and the physicochemical water parameters were performed in the 2004-2006 period. Data on macrophytes were collected with the Mean Trophic Rank (MTR) method. The results of physicochemical measurements were analyzed in reference to the water quality classification of the Polish Ministry of the Environment. Based on the results of these studies, the authors recommend adding two species, Utricularia intermedia and Glyceria fluitans, to the list of bioindicators.
The effect of multiple heavy metals on ascorbate, glutathione and related enzymes in two mangrove plant seedlings (Kandelia candel and Bruguiera gymnorrhiza)
Authors: Huang Guo-Yong , Wang You-Shao , Sun Cui-Ci , Dong Jun-De , Sun Zong-Xun
Published: April 2010

In this study, the effect of multiple heavy metal stress on ascorbate (AsA), glutathione (GSH) and related enzymes was investigated in the leaves, stems and roots of Kandelia candel and Bruguiera gymnorrhiza. Mangrove seedlings were treated with five different concentrations of a heavy metal mixture (Cd2+, Pb2+ and Hg2+). Antioxidants in both the species were analyzed after one month. AsA, GSH, ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2) exhibited a similar trend with initial increase and subsequent decrease in response to heavy metal stress. At the highest metal concentration, a significant decrease of AsA and GR was observed in K. candel and B. gymnorrhiza. Glutathione peroxidase (GPX, EC 1.11.1.9) in the leaves, stems and roots of K. candel reached their respective maximal values at the highest metal concentration, whereas GPX activity in roots and stems of B. gymnorrhiza was similar to the controls at higher metal concentrations. Our results demonstrate that AsA, GSH, APX, GR and GPX in K. candel may play more important roles in defending against reactive oxygen species (ROS) than those in B. gymnorrhiza.
Auto- and heterotrophic picoplankton in a lowland river (Warta River, Poland)
Authors: Szeląg-Wasielewska Elżbieta , Stachnik Waldemar
Published: April 2010

The structure of plankton in a lowland river was studied with a particular focus on autotrophic as well as heterotrophic picoplankton cells. Water samples were collected in the middle, meridional section of the Warta River in 2005. Heterotrophic picoplankton (HPP) were represented by bacteria varying in size and form, but mainly by cocci and rods. HPP abundance ranged from 3.5 × 106 to 9.5 × 106 cells ml-1. Autotrophic picoplankton (APP) densities were considerably lower and ranged from 1.2 × 103 to 92 × 103 cells ml-1. They were represented by prokaryotes (picocyanobacteria) and eukaryotes (small chlorophytes). Both components occurred together but eukaryotic APP usually prevailed in terms of biomass. In terms of biomass, APP seemed to play a minor role in this ecosystem in comparison with heterotrophic picoplankton.
Analysis of environmental conditions and macro-cations composition (Ca, Mg, Na, K, Sr) in the operculum bones of estuarine fishes in the Pomeranian Bay (southern Baltic Sea)
Authors: Tórz Agnieszka , Nędzarek Arkadiusz
Published: April 2010

The aim of this study was to show the influence of environmental conditions on the ionic composition of fish bones. The analysis concerned the ionic structural composition of the operculum in fish species with different abiotic habitat preferences. Three species of fish were examined: cod, Gadus morhua L., 1758; sea trout, Salmo trutta morpha trutta L., 1758 and perch, Perca fluviatilis L., 1758. Results from hydrochemical research on salinity in the Pomeranian Bay (Southern Baltic) were also utilized. Using the determined ratios (Ca:Mg, Na:Mg, Sr:Ca and Na:Ca in the operculum and Ca:Mg, Na:Mg and Na:Ca in the waters of the Pomeranian Bay), typical correlations were determined for the analyzed habitat.

Macrocation structure in the operculum bones for each species were found to be as follows:

- cod: Ca - 32.3%, Mg - 29.8%, Na - 1.4%, K - 0.8%, Sr - 2.1%;

- sea trout: Ca - 22.8%, Mg - 13.5%, Na - 0.8%, K - 0.2%, Sr - 1.7%;

- perch, Ca - 37.9%, Mg - 15.1%, Na - 2.4%, K - 0.7%, Sr - 1.6%.
Diversity of freshwater red algae in Europe
Authors: Kwandrans Janina , Eloranta Pertti
Published: April 2010

Of the total number of freshwater red algae (ca. 180 taxa), one third are found in Europe (ca. 60 taxa). Over one third (24 taxa) of European taxa have been found at only one single location or at very few locations. The majority of taxa live in running waters, but some occur in lakes, on wet ground, in hot springs or in garden ponds. Diversity in the Nordic countries of Sweden and Finland seems to be somewhat higher (27 and 28 taxa, respectively) than in the central and southern parts of Europe (e.g. Austria 23, Belgium 22, Hungary 9, Poland 22, Slovakia 15, Switzerland 12 and Spain 20 taxa).
4-amine-2-mercaptopyrimidine modified silica gel applied in Cd(II) and Pb(II) extraction from an aqueous medium
Authors: Pereira Adriano , Ferreira Guilherme , Caetano Laercio , Castro Renata , Santos Ademir , Padilha Pedro , Castro Gustavo
Published: April 2010

4-amine-2-mercaptopyrimidine modified silica gel applied in Cd(II) and Pb(II) extraction from an aqueous medium

This paper discusses silica surface modification by a process involving a two-step reaction: anchoring of a silylating agent, followed by an attachment of a 4-amino-2-mercaptopyrimidine molecule. The modified material (Si-BP) was successfully characterized by the FTIR spectra, which revealed amine absorption bands, and through 13C and 29Si NMR spectra, which confirm the proposed structure of the modified silica (Si-BP). Si-BP was used to extract cadmium and lead from an aqueous medium at 298 K. The Si-BP kinetics towards metal ions was very fast, i.e., about 10 minutes, although extraction was significantly impaired at pH 3. The series of adsorption isotherms were adjusted to a modified Langmuir equation and the maximum extraction capacity was 0.193 and 0.387 mmol g-1 for Cd(II) and Pb(II), respectively. An analysis of the Ø values lead to the inference that the resulting metal ligand complex was type 1:1.
A new method for the preparation of solvatochromic 5-(5-X-6-hydroxynaphthyl-2)-7H-indolo[1,2-a]quinolinium merocyanines
Authors: Sawicka Marta , Soroka Jacek , Gąsiorowska Monika
Published: April 2010

A new method for the preparation of solvatochromic 5-(5-X-6-hydroxynaphthyl-2)-7H-indolo[1,2-a]quinolinium merocyanines

A new method for the preparation of 7H-indolo[1,2-a]quinolinium solvatochromic dye precursors has been investigated. 5-(6-Hydroxynaphthyl-2)-7,7-dimethyl-7H-indolo[1,2-a]quinolinium perchlorate, 5-(5-bromo-6-hydroxynaphthyl-2)-7,7-dimethyl-7H-indolo[1,2-a]quinolinium perchlorate and 5-(5-nitro-6-hydroxynaphthyl-2)-7,7-dimethyl-7H-indolo[1,2-a]quinolinium perchlorate were obtained via demethylation of the corresponding 5-(5-X-6-methoxynaphthyl-2)-7,7-dimethyl-7H-indolo[1,2-a]quinolinium salts. The application of pyridinium hydrochloride in the demethylation of the methoxy perchlorates allowed to obtain the products with the almost quantitative yield in a very short time, especially when the reaction was carried out using microwave irradiation.
The effect of cathode materials on the electrochemical reduction of nitric acid
Authors: Vasudevan D.
Published: April 2010

The effect of cathode materials on the electrochemical reduction of nitric acid

Electrochemical or chemical reduction of nitric acid is a well studied area in literature due to the importance of the products formed. The present work focuses on the effect of conventional cathode materials including PbO2, amalgamated Cu, graphite, Pb, Pt and a modified electrode material Ti/TiO2 on the reduction of nitric acid. Ammonia and hydroxylamine are the main products which are estimated by conventional titration methods. Other conditions being similar, the product distribution varies quite drastically as a function of the electrode material and Ti/TiO2 is found to favor a higher ratio of hydroxylamine to ammonia formation compared to other electrodes. The conditions have also been optimized based on the maximum yield of the product.
Kinetics of nanocrystalline iron nitriding
Authors: Arabczyk Walerian , Zamłynny Jacek , Moszyński Dariusz
Published: April 2010

Kinetics of nanocrystalline iron nitriding

Nitriding of nanocrystalline iron was studied under the atmosphere of pure ammonia and in the mixtures of ammonia - hydrogen - nitrogen at temperatures between 350°C and 500°C using thermogravimetry and x-ray diffraction. Three stages of nitriding were observed and have been ascribed to the following schematic reactions: (1) α-Fe → γ'-Fe4N, (2) γ'- Fe4N → ε - Fe3N and (3) ε - Fe3N → ε - Fe2N. The products of these reactions appeared in the nitrided nanocrystalline iron not sequentially but co-existed at certain reaction ranges. The dependence of a reaction rate for each nitriding stage on partial pressure of ammonia is linear. Moreover, a minimal ammonia partial pressure is required to initiate the nitriding at each stage.
A Computerized Adaptive Test for Patients With Shoulder Impairments Produced Responsive Measures of Function
Authors: Hart Dennis L. , Wang Ying-Chih , Cook Karon F. , Mioduski Jerome E.
Published: April 2010

Background

Computerized adaptive tests (CATs) promise efficient outcomes data collection with little loss of measurement precision. The shoulder CAT has not been assessed for administrative efficiency, nor have prospective studies been completed to evaluate the sensitivity to change or the responsiveness of CAT-based functional status (CAT-FS) measures.

Objective

The purpose of this study was to evaluate the efficiency and responsiveness of the shoulder CAT.

Design

This was a secondary analysis of prospectively collected data.

Methods

Data were analyzed from patients with shoulder impairments who received outpatient rehabilitation in 518 clinics in 30 US states. Over the testing time, 30,987 patients completed the shoulder CAT at intake, and of these, 13,805 completed the CAT at discharge (45% completion rate). The efficiency of routine CAT administration was evaluated, and the sensitivity to change and responsiveness of CAT-FS measures were assessed.

Results

On average, patients took about 1.5 minutes (SD <2 minutes) to answer 6 CAT items (SD=2), which produced precise estimates of CAT-FS measures that adequately covered the content range and had negligible floor and minimal ceiling effects. Ninety-four percent of the patients had CAT-FS scores between 20 and 80, where upper-level 95% confidence interval (CI) standard errors were between 3.2 and 4.6 (out of 100). Of patients with both intake and discharge data, 79% had CAT-FS change scores greater than minimal detectable change, and 76% had changes greater than minimal clinically important improvement.

Limitations

Because this study was a secondary analysis, the results may have been affected by patient selection bias. Future studies would benefit from more complete data.

Conclusions

The results indicate the shoulder CAT was efficient and support the precision, sensitivity, and responsiveness of CAT-FS measures.
Detectable Changes in Physical Performance Measures in Elderly African Americans
Authors: Mangione Kathleen Kline , Craik Rebecca L. , McCormick Alyson A. , Blevins Heather L. , White Meaghan B. , Sullivan-Marx Eileen M. , Tomlinson James D.
Published: April 2010

Background

African American older adults have higher rates of self-reported disability and lower physical performance scores compared with white older adults. Measures of physical performance are used to predict future morbidity and to determine the effect of exercise. Characteristics of performance measures are not known for African American older adults.

Objective

The purpose of this study was to estimate the standard error of measurement (SEM) and minimal detectable change (MDC) for the Short Physical Performance Battery (SPPB), Timed “Up & Go” Test (TUG) time, free gait speed, fast gait speed, and Six-Minute Walk Test (6MWT) distance in frail African American adults.

Design

This observational measurement study used a test-retest design.

Methods

Individuals were tested 2 times over a 1-week period. Demographic data collected included height, weight, number of medications, assistive device use, and Mini-Mental Status Examination (MMSE) scores. Participants then completed the 5 physical performance tests.

Results

Fifty-two participants (mean age=78 years) completed the study. The average MMSE score was 25 points, and the average body mass index was 29.4 kg/m2. On average, participants took 7 medications, and the majority used assistive devices. Intraclass correlation coefficients (ICC [2,1]) were greater than .90, except for the SPPB score (ICC=.81). The SEMs were 1.2 points for the SPPB, 1.7 seconds for the TUG, 0.08 m/s for free gait speed, 0.09 m/s for fast gait speed, and 28 m for 6MWT distance. The MDC values were 2.9 points for the SPPB, 4 seconds for the TUG, 0.19 m/s for free gait speed, 0.21 m/s for fast gait speed, and 65 m for 6MWT distance.

Limitations

The entire sample was from an urban area.

Conclusions

The SEMs were similar to previously reported values and can be used when working with African American and white older adults. Estimates of MDC were calculated to assist in clinical interpretation.
Postpartum sexual function of women and the effects of early pelvic floor muscle exercises
Authors: CITAK NEVIN , CAM CETIN , ARSLAN HEDIYE , KARATEKE ATES , TUG NIYAZI , AYAZ REYHAN , CELIK CEM
Published: April 2010

Objective. To evaluate the effects of early pelvic floor muscle training after vaginal delivery on sexual function. Design. Prospective randomized study. Settings. Urogynecology clinic of a tertiary medical center in Istanbul, Turkey. Population. Total of 75 primiparous women. Methods. Pelvic floor‐muscle strength was assessed during rest and straining in primiparous women in their 4th postpartum month, after which the women were randomized into training (n = 37) and control (n = 38) groups. Patients were re‐evaluated in the 7th postpartum month. Main outcome measures. Female sexual function and pelvic muscle strength scores. Results. Desire, pain and total female sexual index scores were significantly higher in the 7th month compared to 4th month in both groups (p < 0.05). However, sexual arousal, lubrication, orgasm, and satisfaction scores were improved in the 7th month in the training group (paired t‐test, p < 0.001), but not significantly in the control group (p > 0.05). All domains except satisfaction were significantly higher in the training group compared with the controls. Pelvic floor‐muscle strength was found to be increased in the 7th month in the training group (Wilcoxon rank test, Z = 4.123, p < 0.001), whereas there was no significant difference between the 4th and 7th month measurements in the controls (p > 0.05). Conclusion. Pelvic floor‐muscle training improves pelvic floor‐muscle function, and starting after the puerperal period, exercise appears to have positive effects on female sexual function.
Does allocation of low risk parturient women to a separate maternity unit decrease the risk of emergency cesarean section?
Authors: NESHEIM BRITT‐INGJERD , ESKILD ANNE , GJESSING LEIF
Published: April 2010

Objective. To study whether the selection of low risk parturient women into a separate maternity unit leads to a lower risk of emergency cesarean section, compared to giving birth in a unit with mixed cases. Design. Hospital based registry study. Setting. Maternity units in two university hospitals in Oslo, Norway. Population. All low risk parturient women with attempted vaginal deliveries in the years 2001–2003, a total number of 11,686 deliveries. Methods. Data were obtained from standardized patient records and risks of cesarean section were estimated as odds ratios. Main outcome measures. Emergency cesarean section risk. Results. Compared with women giving birth in a unit with mixed cases, women giving birth in a maternity unit with low risk cases only had a higher risk of emergency cesarean section (OR 1.4; 95% CI 1.2–1.6). Conclusions. Giving birth in a low risk maternity unit is associated with a higher risk of cesarean section for low risk parturient women compared with giving birth in a maternity unit with mixed cases.
Obstetric fistula in 14,928 Ethiopian women
Authors: MULETA MULU , RASMUSSEN SVEIN , KISERUD TORVID
Published: April 2010

Objectives. Obstetric fistulas are severe sequelae of prolonged obstructed labor, a widespread but incompletely documented problem of low‐income countries. Here, we characterize women with obstetric fistula, test the hypothesis that primi‐ and multipara represent different profiles and that fetal size is an important factor in developing fistula. Design. Hospital registry statistics and questionnaire. Population. A total of 14,928 Ethiopian women with obstetric fistula in 1974–2006 and 434 admitted in 2007–8. Methods. Self‐reported age, marital status, education, distance from home to health facility, parity, duration of labor, neonatal outcome and sex, lag time to treatment; measurement of weight, stature, extent of lesion and clinical assessment of continence before hospital discharge. Outcome measures. Duration of labor, extent of pelvic injury and neonatal survival, cure rate. Results. Primi‐ were more common than multiparous cases (56.8 vs. 43.2%). They were of similar age at marriage (17 years) and stature at hospital admission, but shorter than the population average (152.7 vs. 156.5 cm). Primipara had longer labor than multipara (50.5% > 3 days vs. 27%), larger uro‐vaginal fistula, more stillbirths (95 vs. 88%), recto‐vaginal fistula, vaginal scarring, persistent incontinence after repair and were more commonly divorced. Male fetuses were involved in 76.7% of obstructed deliveries but in only 44.6% of a previous uneventful delivery in multipara. Educational attainment positively influenced outcomes. Conclusions. Obstetric fistula is more commonly associated with primiparous than subsequent pregnancies. Primipara have a longer and more damaging labor. A causative role for cephalo‐pelvic disproportion is supported by the observation that male fetuses are more commonly involved in obstructed labor.
Pelvic artery embolization in the management of obstetric hemorrhage
Authors: SIDHU HARPREET KAUR , PRASAD GRV , JAIN VANITA , KALRA JASWINDER , GUPTA VIVEK , KHANDELWAL NIRANJAN
Published: April 2010

We studied the role of pelvic artery embolization in management of obstetric hemorrhage by retrospective analysis of 50 cases of obstetric hemorrhage in a tertiary care referral hospital where this procedure was used. Uterine and or internal iliac artery embolization was performed for the management of postpartum hemorrhage (39 cases; 78%), post abortal bleeding (6 cases; 12%) and gestational trophoblastic disease (4 cases; 8%). In one case of postpartum hemorrhage procedure could not be performed due to arterial spasm (2%). Prophylactic embolization was carried out in one case of placenta accreta. The mean age of the women was 27 years and 54% were primiparas. In six women embolization was done after hysterectomy failed to control pelvic hemorrhage. One fourth of women had coagulopathy at the time of presentation. There were five cases of pelvic hematoma and three cases of arteriovenous malformations. The success rate of the procedure was 94% and the procedure was unsuccessful for controlling bleeding in three women. There were no major procedure related complications. Thus, pelvic artery embolization is an effective alternative to surgery in controlling obstetric hemorrhage and as a fertility and life‐saving procedure.
Suicide by Occupation: Does Access to Means Increase the Risk?
Authors: Skegg Keren , Firth Hilda , Gray Andrew , Cox Brian
Published: April 2010

Objective: To examine suicide by identified occupational groups in New Zealand over a period of 30 years, focusing on groups predicted to have high suicide rates because of access to and familiarity with particular methods of suicide.

Method: Suicide data (including open verdicts) for the period 1973–2004 were examined, excluding 1996 and 1997 for which occupational data were not available. Occupational groups of interest were dentists, doctors, farmers (including farm workers), hunters and cullers, military personnel, nurses, pharmacists, police and veterinarians. Crude mortality rates were calculated based on numbers in each occupational group at each quinquennial census, 1976–2001. Standardized mortality ratios were calculated using suicide rates in all employed groups (the standard population).

Results: Few of the occupations investigated had high risks of suicide as assessed by standardized mortality ratios, and some were at lower risk than the total employed population. Standardized mortality ratios were elevated for male nurses (1.7; 95% CI: 1.2–2.5), female nurses (1.3; 95% CI: 1.0–1.6), male hunters and cullers (3.0; 95% CI: 1.7–4.8), and female pharmacists (2.5; 95% CI: 0.8–5. 9). Doctors, farmers and veterinarians were not at high risk, and men in the police and armed forces were at low risk. Access to means appeared to have influenced the method chosen. Nurses, doctors and pharmacists were more likely to use poisoning than were other employed people (3, 4 and 5 times respectively, compared with all others employed). Farmers and hunters and cullers were more than twice as likely as all others employed to use firearms.

Conclusions: Access to means may be less important in some circumstances than in others, perhaps because of the presence of other factors that confer protection. Nevertheless, among the groups we studied with access to lethal means were three groups whose risk of suicide has so far received little attention in New Zealand: nurses, female pharmacists, and hunters and cullers.
Prediction of Aggression and Restraint in Child Inpatient Units
Authors: Crocker Jandi H. , Stargatt Robyn , Denton Christine
Published: April 2010

Objective: The aim of the present exploratory study was to determine the predictors of aggression and restraint in children admitted to a child psychiatric inpatient unit in Melbourne, Australia.

Method: A retrospective review of incident report forms over a 12 month period at the State Wide Child Inpatient Unit (SWCIU) was conducted. These report forms were based upon 41 children aged 5–12 years, who had various psychiatric diagnoses including conduct disorder, attention-deficit–hyperactivity disorder and anxiety disorders.

Results: A total of 70 children were admitted to the SWCIU during the audit period. Forty-one children aged 5–12 engaged in 235 violent incidents. A high-risk assessment and disruptive behaviour disorder were associated with aggressive behaviour and restraint. Disruptive behaviour disorder also predicted more serious episodes of aggression.

Conclusions: There are readily identifiable patient factors that predict aggression and the need for restraint in child inpatient units.
Gender Differences in Sociodemographic and Clinical Characteristic and the Quality of Life of Chinese Schizophrenia Patients
Authors: Xiang Yu-Tao , Weng Yong-Zhen , Leung Chi-Ming , Tang Wai-Kwong , Chan Sandra S. M. , Wang Chuan-Yue , Han Bai , Ungvari Gabor S.
Published: April 2010

Objective: The aim of the present study was to determine the sociodemographic and clinical correlates of the gender of Chinese schizophrenia outpatients and their impact on patients quality of life (QOL).

Methods: Two hundred and fifty-five clinically stable schizophrenia outpatients were randomly selected in Hong Kong. Counterparts matched according to gender, age, age at onset, and length of illness were recruited in Beijing, China. All of the subjects at both sites were interviewed by the same investigator using standardized assessment instruments.

Results: The combined Beijing–Hong Kong sample contained 251 male and 254 female patients. On univariate analysis more male patients were employed, they had a significantly higher monthly income, and took higher doses of antipsychotic drugs. No difference was found, however, in any of the QOL domains between the genders. On multivariate analysis being employed, taking a higher dose of antipsychotic drugs, having more severe extrapyramidal side-effects, and a higher score on the physical domain of QOL were independently associated with male gender.

Conclusion: Female gender is independently associated with lower scores on the physical aspects of QOL, but there is no difference between the genders in the psychological, social and environmental aspects.
Cigarette Smoking in Patients with Schizophrenia in China: Prospective, Multicentre Study
Authors: Wang Chuan-Yue , Xiang Yu-Tao , Weng Yong-Zhen , Bo Qi-Jing , Chiu Helen F. K. , Chan Sandra S. M. , Lee Edwin H. M. , Ungvari Gabor S.
Published: April 2010

Objective: The aim of the present study was to explore the rate of cigarette smoking and its sociodemographic and clinical characteristics in Chinese schizophrenia patients.

Methods: In a multicentre, randomized, controlled, longitudinal study, 374 clinically stable patients with schizophrenia were interviewed at entry using standardized assessment instruments, and followed up for 1–2 years.

Results: The rate of cigarette smoking was 13.9% in the whole sample, and 26.2% in men and 3.5% in women. On univariate analysis, male sex, unemployment, alcohol consumption, older age, older age at onset, longer duration of illness, more frequent admissions, more severe hostility–excitement at entry and less deterioration in hostility–excitement over the study period were significantly associated with cigarette smoking. On multivariate analysis, male sex, unemployment, alcohol consumption, more frequent admissions, less severe positive and negative symptoms at entry, smaller decline in negative symptoms and more deterioration in disorganized thoughts over the study period were independently associated with cigarette smoking.

Conclusion: The rate of cigarette smoking in Chinese schizophrenia patients is considerably lower than most figures reported in the Western literature.
Anticholinesterase Duration in the Australian Veteran Population
Authors: Gadzhanova Svetla , Roughead Libby , Mackson Judith
Published: April 2010

Objective: The aim of the present study was to determine the duration of initial anticholinesterase treatment in veteran patients in Australia. Three anti-dementia medications were investigated (donepezil, rivastigmine and galantamine) and two different setting were compared (community and residential aged care facilities).

Method: A retrospective cohort study was performed using the Department of Veterans’ Affairs pharmacy claims data. Patients were included in the cohort if they had been dispensed at least one anticholinesterase prescription (index) between 2003 and 2006, were aged 65 years or over at the time of that index dispensing, and had not been dispensed any anticholinesterase medicine in the previous 12 months. Patients were followed until discontinuation (ceased or switched), death or 1 year of follow up. Time to treatment discontinuation was analysed utilizing the Kaplan-Meier method. Cox proportional hazards models were used to compare the risk of treatment discontinuation among the three treatment groups adjusting for the effect of patients’ characteristics.

Results: Of the new users of anticholinesterases (n = 10088), 47% of those on donepezil, 46% of those on galantamine, and 47% of rivastigmine patients discontinued their initial therapy within 6 months. A total of 32% of patients who ceased therapy reinitiated it during the study period; 28% returned to the same index medication and 4% restarted therapy with a different anticholinesterase. The median treatment duration was: 199 days (95% CI, 182–208) for donepezil patients (n = 6705), 233 days (95% CI, 212–259) for galantamine patients (n = 2898), and 219 days (95% CI, 176–260) for rivastigmine patients (n = 394). Patients in community settings were more likely to discontinue their initial anticholinesterases earlier compared to those living at residential aged care facilities (relative risk, RR=1.21; 95% CI, 1.12, 1.31).

Conclusions: Almost half of the Australian veteran patients who initiated anticholinesterases treatment discontinued (ceased or switched) therapy within 6 months. However, one-third of those who ceased therapy reinitiated it during the study period.