bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of ethylene carbonate from urea and ethylene glycol over zinc/iron oxide catalyst
Authors: Zhao Xinqiang , An Hualiang , Wang Shufang , Li Fang , Wang Yanji
Published: February 2008

BACKGROUND: Ethylene carbonate (EC) was synthesised via urea and ethylene glycol (EG) over zinc/iron oxide catalyst. By so doing, the by‐product, EG, generated in the process of producing dimethyl carbonate by the transesterification route was converted back to the raw material, EC. The reaction mechanism of EC synthesis was also investigated by means of gas chromatography/mass spectrometry and in situ Fourier transform infrared/attenuated total reflection spectroscopy.

RESULTS: Suitable conditions for the preparation of zinc/iron oxide catalyst were as follows: zinc acetate and iron nitrate as precursors, Zn/Fe molar ratio 8:1, calcination temperature 350 °C and calcination time 4 h. Characterisation by X‐ray diffraction revealed two different crystal phases: ZnO and ZnFe2O4. The highest yield of EC (66.1%) was obtained under the following conditions: reaction temperature 150 °C, reaction time 2.5 h, catalyst weight percentage 1.5% and urea/EG molar ratio 1:8. The study of the reaction mechanism revealed that the reaction for the synthesis of EC proceeded in two steps.

CONCLUSION: The synergistic effect of ZnO and ZnFe2O4 promoted the catalytic performance of zinc/iron oxide. Copyright © 2008 Society of Chemical Industry
Energy substrate efficiency during batch cultures of Geotrichum candidum
Authors: Aziza Majda , Adour Lydia , Amrane Abdeltif
Published: February 2008

BACKGROUND: Metabolisation of carbon and nitrogen substrates is a key factor during the ripening process of white soft cheeses but has not previously been examined in terms of energy substrate efficiency. Such work could be useful to improve physiological knowledge concerning Geotrichum candidum, a yeast involved in the neutralisation of curd during ripening. Its behaviour was therefore examined during batch cultures on simple (glutamate) or complex (peptones) substrates as nitrogen and carbon sources and lactate as a second carbon source.

RESULTS: In addition to their assimilation as carbon and nitrogen sources, G. candidum used peptides and amino acids as energy sources during growth in preference to lactate. Contrarily, during stationary state, lactate was preferred over peptides and amino acids for carbon dissimilation for energy supply, allowing the avoidance of ammonium production. Indeed, lactate dissimilation theoretically yields 15 adenosine triphosphates (ATPs), while only nine ATPs are theoretically yielded during the dissimilation of an amino acid such as glutamate.

CONCLUSION: This behaviour can be considered as an energy‐saving response. Indeed, the use of peptides and amino acids as energy sources in addition to being used as carbon and nitrogen sources during G. candidum growth can be related to its deaminating activity and was in agreement with the better energy efficiency expected from utilisation of the same substrate as both carbon and energy source. Contrarily, the better efficiency of lactate dissimilation led to its use during stationary state instead of peptides and amino acids. Copyright © 2008 Society of Chemical Industry
Management of hepatic metastasis of gastrointestinal carcinoid tumors
Authors: Landry Christine S. , Scoggins Charles R. , McMasters Kelly M. , Martin Robert C.G.
Published: February 2008

Background

Hepatic resection, radiofrequency ablation, intra‐arterial radiation therapy, and chemoembolization are all potential therapies in the treatment of metastatic carcinoid tumors of the liver. The aim of this study was to determine the prognostic factors in the management of hepatic metastases of gastrointestinal carcinoid tumors.

Methods

We reviewed our prospective database of 1084 hepato‐pancreatico‐biliary patients for patients with the diagnosis of metastatic carcinoid to the liver from 6/1998 to 9/2006.

Results

We identified 54 patients, 21 men, 33 women, median age 59 years (range 37–86), median number of tumors 3 (range 1–27), and median size of hepatic metastasis of 4 cm (range 1–13). Hepatic resection was performed in 23 (43%) with 16 (70%) receiving additional hepatic directed therapy. Hepatic resection was found to have a statistically significant improved overall survival (P < 0.05) when compared to nonhepatic resection patients with an actuarial 5 years survival for surgical (75%) compared to nonsurgical (62%). Multivariate analysis demonstrated that the use of tobacco was a significant factor in poor overall outcome (P = 0.005).

Conclusion

Multimodality therapy in the management of hepatic carcinoid metastasis can be done safely and effectively. We recommend the use of hepatic resection when feasible as this treatment most likely offers the best long‐term outcome. J. Surg. Oncol. 2008;97:253–258. © 2008 Wiley‐Liss, Inc.
Evaluation of separation in gradient elution ion chromatography by combining several retention models and objective functions
Authors: Bolanča Tomislav , Cerjan‐Stefanović Štefica , Luša Melita , Ukić Šime , Rogošić Marko
Published: February 2008

In this work, three different methods for modeling of gradient retention were combined with several optimization objective functions in order to find the most appropriate combination to be applied in ion chromatography method development. The system studied was a set of seven inorganic anions (fluoride, chloride, nitrite, sulfate, bromide, nitrate, and phosphate) with a KOH eluent. The retention modeling methods tested were multilayer perceptron artificial neural network (MLP‐ANN), radial‐basis function artificial neural network (RBF‐ANN), and retention model based on transfer of data from isocratic to gradient elution mode. It was shown that MLP retention model in combination with the objective function based on normalized retention difference product was the most adequate tool for optimization purposes.
GC‐MS method development and validation for anabolic steroids in feed samples
Authors: Muñiz‐Valencia Roberto , Ceballos‐Magaña Silvia G. , Gonzalo‐Lumbreras Raquel , Santos‐Montes Ana , Izquierdo‐Hornillos Roberto
Published: February 2008

A GC‐MS method for the determination of AAS used as growth promoting agents using SIM in piglet feed samples has been developed and validated, using testosterone as internal standard. The formation of volatile steroid derivatives was carried out by derivatization with N‐methyl‐N‐(trimethylsilyl)trifluoroacetamide. The optimum separation was achieved using a Zebron ZB‐5 column under a gradient temperature elution, allowing the separation of steroids in 18 min. The required sample treatment process was discussed. A leaching using ACN, saponification using a binary NaOH/MgCl2 solution, and LLE using ethyl acetate were finally selected. Method validation has been carried out according to the Commission Decision 2002/657/EC criteria established for quantitative confirmatory methods. The extraction efficiencies, CCα and CCβ for these compounds were in the ranges 78–98%, 10–21 and 18–35 μg/kg, respectively. The repeatability and the within‐laboratory reproducibility at 1, 1.5, and 2 CCβ concentration levels were smaller than 8.2, 7.5, and 5.8% and 12.2, 9.5, and 7.5%, respectively. Accuracy was in the 99–103% range. The robustness was evaluated using the Youden robustness test. The proposed method was applied to the analysis of steroids spiked in different kinds of animal feed samples with satisfactory results.
Simultaneous determination by UPLC–ESI‐MS of scoparone, capillarisin, rhein, and emodin in rat urine after oral administration of Yin Chen Hao Tang preparation
Authors: Lv Haitao , Sun Hui , Wang Xijun , Sun Wenjun , Jiao Guozheng , Zhou Dixin , Zhao Li , Cao Hongxin , Zhang Guangmei
Published: February 2008

A simple, sensitive, and validated method was developed for simultaneous determination of scoparone, capillarisin, rhein, and emodin in rat urine by ultra‐performance liquid chromatography/electrospray ionization quadruple time‐of‐flight mass spectrometry (UPLC–MS). The urinary samples were analyzed on an Acquity UPLC BEH C18 1.7 μm 2.1×50 mm column. Scoparone, capillarisin, rhein, and emodin in rat urine were simultaneously analyzed with good separation. The lower limits of detection were 6.0, 9.0, 7.0, and 3.0 ng/mL, and the lower limits of quantification were 20.0, 33.0, 24.0, and 12.0 ng/mL for scoparone, capillarisin, rhein, and emodin, respectively. The intra‐ and inter‐day precisions (RSD) were less than 9%. The intra‐ and inter‐accuracies were found to be in the range of 94.14–104.54% for scoparone, 101.72–107.34% for capillarisin, 95.24–103.59% for rhein, and 101.32–107.82% for emodin at three concentration levels. The absolute recoveries for scoparone, capillarisin, rhein, and emodin were not less than 77.0%. The developed method has been applied to determine scoparone, capillarisin, rhein, and emodin in rat urine after oral administration of Yin Chen Hao Tang preparation, a traditional Chinese medicine formulation widely used in China for treatment of jaundice and liver disorders.
Cortical excitability in DYT‐11 positive myoclonus dystonia
Authors: Sabine Meunier  , George Lourenco  , Roze Emmanuel , Apartis Emmanuelle , Trocello Jean‐Marc , Marie Vidailhet
Published: February 2008

Myoclonus‐dystonia (M‐D) is an autosomal dominant movement disorder caused by mutations in the ε‐sarcoglycan gene (DYT11). We explore pathophysiological characteristics of M‐D with the hypothesis that they may be different from those of sporadic or genetic dystonia. We compared five carriers of the DYT11 gene mutation and 10 healthy controls. Using transcranial magnetic stimulation, we measured parameters assessing cortical membrane excitability (active motor threshold, aMT) and synaptic activity (short interval, sICI) and afferent (AI) intracortical inhibitions and their interaction. aMT was significantly higher in the DYT11 gene carriers than in normal subjects. The others parameters (sICI, AI and their interaction) were not different between the two groups. In DYT11 gene carriers cortical membrane excitability was impaired while parameters assessing cortical synaptic activity were normal. Opposite results have been obtained in focal sporadic and generalized DYT1 dystonias. © 2008 Movement Disorder Society
Preparation and properties of superabsorbent containing starch and sodium humate
Authors: Hua Shuibo , Wang Aiqin
Published: February 2008

Starch and sodium humate were utilized as raw material for synthesizing starch‐g‐poly(acrylic acid)/sodium humate (St‐g‐PAA/SH) superabsorbent by graft copolymerization reaction of starch (St) and acrylic acid (AA) in the presence of sodium humate (SH) in aqueous solution. The effect of weight ratio of AA to St, initial monomer concentration, neutralization degree of AA, amount of crosslinker, initiator and SH on water absorbency of the superabsorbent were studied. The swelling rate and swelling behavior in NaCl solution as well as reswelling ability of the superabsorbent were systematically investigated. The results showed that the superabsorbent synthesized under optimal conditions with SH content of 7.7 wt% and St content of 11.5 wt% exhibits water absorbency of 1100 g/g in distilled water and 86 g/g in 0.9 wt% NaCl solution, respectively. Introducing SH into the St‐g‐PAA polymeric network can improved the swelling rate and reswelling capability of the superabsorbent. Copyright © 2008 John Wiley & Sons, Ltd.
Physiological distribution of placental growth factor and soluble Flt‐1 in early pregnancy
Authors: Makrydimas George , Sotiriadis Alexandros , Savvidou Makrina D. , Spencer Kevin , Nicolaides Kypros H.
Published: February 2008

Objective

To examine the distribution of placental growth factor (PlGF), vascular endothelial growth factor (VEGF) and soluble VEGF receptor‐1 (sFlt‐1) in maternal and embryonic fluid compartments in early pregnancy.

Method

The concentrations of PlGF, VEGF and sFlt‐1 were measured in coelomic fluid and maternal serum from 16 singleton pregnancies at 7.0–9.3 weeks. In six cases, amniotic fluid was also examined.

Results

The median concentration of PlGF was 14.1 (range 8.9–27.6) pg/mL in maternal serum, 13.9 (range 9.5–31.4) pg/mL in coelomic fluid and 8.9 (range 3.9–15.3) pg/mL in amniotic fluid. The concentration of PlGF increased between 7.0 and 9.3 weeks in maternal serum (p = 0.001) and decreased in coelomic and amniotic fluid (p = 0.001). The median concentration of sFlt‐1 was 8561 (range 6724‐10 673) pg/mL in coelomic fluid, 523 (range 244–986) pg/mL in maternal serum, 30 (range 12–83) pg/mL in amniotic fluid (p = 0.0001), and it did not change significantly with gestation. VEGF was undetectable in most of the samples, and therefore, no further analysis was performed.

Conclusion

PlGF and sFlt‐1 are present in the maternal and fetal fluid compartments in very early pregnancy, and their distribution is consistent with their site of production and the local conditions of transport. Copyright © 2008 John Wiley & Sons, Ltd.
Prenatal diagnosis of β‐thalassemia by chip‐based capillary electrophoresis
Authors: Hu Hua , Li Caixia , Xiong Qiang , Gao Huafang , Li Yan , Chang Qing , Liang Zhiqing
Published: February 2008

Objective

To explore the potential of chip‐based capillary electrophoresis for rapid prenatal diagnosis of genetic diseases, we developed a prenatal diagnosis method for β‐thalassemia, one of the most common recessive inherited disorders.

Method

DNA samples containing known mutations of β‐thalassemia were used to optimize multiplex allele‐specific PCR and chip‐based capillary electrophoresis was used to simultaneously detect Cy3‐labeled PCR products and Cy5‐labeled ladder. This system was validated by detecting 40 unknown cases, 4 of which were processed further for prenatal diagnosis.

Results

We analyzed previously genotyped samples and unknown samples by this method and the results were concordant with those from reverse dot blot and direct sequencing. Prenatal diagnosis was carried out successfully and rapidly on 1 µL (1 ng/µL) sample in 4 pregnancy cases carrying potential β‐thalassemia risk.

Conclusion

This chip‐based capillary electrophoresis detecting system could be used for prenatal diagnosis of β‐thalassemia and will facilitate the rapid and sensitive prenatal diagnosis of genetic disorder. Copyright © 2008 John Wiley & Sons, Ltd.
Maternal serum ADAM12s as a potential marker of trisomy 21 prior to 10 weeks of gestation
Authors: Spencer Kevin , Vereecken Annie , Cowans Nicholas J.
Published: February 2008

Background

ADAM12s (a disintegrin and metalloprotease) is a placenta‐derived glycoprotein that is involved in growth and differentiation and has been shown to be a potential first‐trimester and second‐trimester marker of trisomy 21 and other aneuploides. Maternal ADAM12s concentrations show a considerable temporal variation with gestational age and in the initial study levels were found to be significantly reduced in the early first trimester. Here we study the levels prior to 10 weeks of gestation to establish further the effectiveness or otherwise of ADAM12s as an early screening marker.

Materials and Methods

Samples collected as part of routine first‐trimester screening were retrieved from storage. In total, ten samples from singleton pregnancies with trisomy 21 were identified and were collected between the 8th and 9th weeks of gestation—of these 80% had been identified by combined first‐trimester screening. A series of 62 gestational age‐matched samples from singleton pregnancies collected during the same period formed the control group. ADAM12s was measured by a new DELFIA assay incorporating two monoclonals (6E6 and 8F8). Results were expressed as multiples of the median (MoM).

Results

The median MoM ADAM12s at a median gestation of 9.3 weeks was 0.61 which was significantly lower than in the controls (p = 0.011) when compared by the Mann–Whitney test. The corresponding median pregnancy associated plasma protein (PAPP‐A) was 0.30 and free beta‐human chorionic gonadotropin (β‐hCG) 2.02.

Conclusions

Combining the data from this study and from the only other published study with data prior to 10 weeks suggests that ADAM12s may have the potential as an early screening marker for trisomy 21, but may not be as reduced as first thought. Copyright © 2008 John Wiley & Sons, Ltd.
Carrier frequency of autosomal‐recessive disorders in the Ashkenazi Jewish population: should the rationale for mutation choice for screening be reevaluated?
Authors: Fares Fuad , Badarneh Khader , Abosaleh Mohamed , Harari‐Shaham Amalia , Diukman Roni , David Miriam
Published: February 2008

Background

Ashkenazi Jewish (AJ) population is at increased risk for several recessive inherited diseases. Therefore, carrier testing of AJ members is important in order to identify couples at risk of having offspring with an autosomal recessive disorder.

Methods

In the present study, a database containing the results of 28 410 genotyping assays was screened. Ten thousand seventy eight nonselected healthy members of the AJ population were tested for carrier status for the following diseases; Gaucher disease (GD), cystic fibrosis (CF), Familial dysautonomia (FD), Alpha 1 antitrypsin (A1AT), Mucolipidosis type 4 (ML4), Fanconi anemia type C (FAC), Canavan disease (CD), Neimann‐Pick type 4 (NP) and Bloom syndrome (BLM).

Results

The results demonstrated that 635 members were carriers of one mutation and 30 members were found to be carriers of two mutations in the different genes related to the development of the above mentioned diseases. GD was found to have the highest carrier frequency (1:17) followed by CF (1:23), FD (1:29), A1AT (1:65), ML4 (1:67) and FAC (1:77). The carrier frequency of CD, NP and BLM was 1:82, 1:103 and 1:157, respectively.

Conclusions

The frequency of the disease‐causing mutations screened routinely among the AJ population indicated that there are rare mutations with very low frequencies. The screening policy of the disease‐causing mutations should be reevaluated and mutations with a high frequency should be screened, while rare mutations with a lower frequency may be tested in partners of carriers. Copyright © 2008 John Wiley & Sons, Ltd.
On the atomic level deformations in the auxetic zeolite natrolite
Authors: Gatt Ruben , Zammit Victor , Caruana Christian , Grima Joseph N.
Published: February 2008

Auxetics (i.e. systems with negative Poisson's ratios) exhibit the unexpected feature of becoming fatter when stretched and narrower when compressed. A particular class of materials which has attracted significant attention in recent years in view of its potential for auxeticity is that of zeolites, in particular, the zeolite NAT where auxeticity has now been experimentally measured. Here we use molecular modelling to accurately reproduce through force‐field based simulations the experimentally measured negative Poisson's ratios in NAT. We also simulate and measure the atomic level deformations that result when NAT is mechanically deformed and use these to evaluate whether existing models can be used to explain the negative Poisson's ratios in natrolite. In particular we show that existing 2D models involving ‘rotating semi‐rigid quadrilaterals' can explain some aspects of the behaviour of NAT and make suggestions how such models can be improved so as to provide a better description of NAT in the auxetic (001) plane. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Retrievable Inferior Vena Cava Filters in High‐Risk Trauma and Surgical Patients: Factors Influencing Successful Removal
Authors: Hermsen Joshua L. , Ibele Anna R. , Faucher Lee D. , Nale Jennifer K. , Schurr Michael J. , Kudsk Kenneth A.
Published: February 2008

Background

An Inferior vena cava filter (IVCF) provides prophylaxis against pulmonary embolism in patients that cannot be anticoagulated. A removable IVCF (R‐IVCF) provides prophylaxis during a high‐risk period while potentially eliminating long‐term complications associated with a permanent IVCF. Factors influencing success of R‐IVCF removal are ill‐defined.

Methods

The study was a retrospective review of a prospectively maintained patient registry comprising patients who received an R‐IVCF (Bard RecoveryTM and G2TM) at an academic level 1 trauma center. The influence of time in vivo, filter design, and filter head position on computed abdominal tomographic (CAT) scan (touching caval wall vs. free) on removal success was examined.

Results

Ninety‐two patients each received an R‐IVCF. Thirty‐nine patients underwent removal attempt and 30 R‐IVCFs were removed. Time in vivo did not affect removal success (success: 228 ± 104 days versus unsuccessful: 289 ± 158 days, p = 0.18). Filter design impacted filter head position (Recovery: 43% touching versus G2: 6% touching, p = 0.023). Position of the filter head influenced removal success (touching: 50% success versus free: 88% success, p = 0.021).

Conclusions

Position of the filter head is the key determinant of removal success. Specific device designs may impact filter head position as was the case with the two designs in this analysis. Time in vivo does not affect removal success.
Contributions of growth, stasis, and reproduction to fitness in brooding and broadcast spawning marine bivalves
Authors: Ripley Bonnie J. , Caswell Hal
Published: February 2008

Reproductive modes in marine invertebrates can be generally grouped into two types: those brooding larvae and those broadcast‐spawning gametes into the water. We asked if these different life‐history strategies differ based on how contribution to fitness is partitioned between growth, stasis, and reproduction. To investigate this question, we used published demographic data on ten diverse species of marine bivalves. We parameterized simple matrix‐population models and calculated the sums of elasticities to growth, stasis, and reproduction parameters and plotted the results on triangular axes. We also assessed whether contribution patterns were correlated with reproductive mode and tropical, temperate, or polar environments. We found that some of the broadcast spawners fell in the region of the plot with high elasticities for stasis and that some of the brooders fell in the region of the plot with higher growth and reproduction elasticities than stasis ones. However, instead of a sharp dichotomy, we found a continuum in contributions of stasis parameters with long‐lived brooders and short‐lived broadcast spawners in the same region of the plot. There was no clear pattern of reproductive mode associated with any particular environment, but we think these preliminary results are intriguing and that further work on comparative demography of marine invertebrates is warranted.
The effect ofCercidium praecoxandProsopis laevigataon vertical distribution of soil free‐living nematode communities in the Tehuacán Desert, Mexico
Authors: Pen‐Mouratov Stanislav , Rodriguez‐Zaragoza Salvador , Steinberger Yosef
Published: February 2008

Vegetation cover is known to act as an abiotic mediator influencing the structure of soil fauna communities in arid and semi‐arid ecosystems. The aim of the current research was to determine the spatial dispersion of the soil free‐living nematode community under the canopy ofCercidium praecoxandProsopis laevigataduring the rainy season. These shrubs are the dominant plant associations in the western part of the Tehuacán‐Cuicatlán Valley in Mexico. Soil samples were taken from each 10‐cm depth between 0 and 50 cm in August 2004. Our results demonstrated that the abundance and structure of the soil free‐living nematode communities in the study area were strongly dependent on plant effects, specified by limited factors such as soil moisture and organic matter availability. The greatest degree of abundance of soil‐free‐living nematodes (88%) was found in the upper (0–10 cm) soil layer. Plant parasites were the most abundant trophic group under the two plants (58 and 36% underParkinsonia(Cercidium) praecoxandProsopis laevigata, respectively), whereas omnivore‐predators were the most dominant (96%) in inter‐plant spaces. The fungivore/bacterivore (F/B) ratio was found to be the most useful tool of the ecological indices tested in the present study, reflecting the vertical distribution of the free‐living nematode communities beneath different plant species in the different soil layers. The soil free‐living nematode communities and their vertical distribution were found to be affected by plant ecophysiological adaptation, soil moisture, and the interaction between them.
Physico‐Chemical Characteristics of Citrus Seeds and Seed Oils from Pakistan
Authors: Anwar Farooq , Naseer Rehana , Bhanger M. I. , Ashraf Samia , Talpur Farah Naz , Aladedunye Felix Adekunle
Published: February 2008

The physico‐chemical characteristics of the seeds and seed oils of four citrus species, Mitha (Citrus limetta), Grapefruit (Citrus paradisi), Mussami (Citrus sinensis), and Kinnow (Citrus reticulata) were investigated. The hexane‐extracted oil content of citrus seeds ranged from 27.0 to 36.5%. The protein, fiber and ash contents were found to be 3.9–9.6%, 5.0–8.5%, and 4.6–5.6%, respectively. The extracted oils exhibited an iodine value of 99.9–110.0; refractive index (40 °C), 1.4639–1.4670; density (24 °C), 0.920–0.941 mg/mL; saponification value, 180.9–198.9; unsaponifiable matter, 0.3–0.5%; acid value (mg KOH/g of oil), 0.5–2.2 and color (1‐in. cell) 1.4–3.0R + 15.0–30.0Y. The oils revealed a good oxidative stability as indicated by the determinations of specific extinctions at 232 and 270 nm (2.3–4.4 and 0.6–0.9, respectively), p‐anisidine value (2.2–3.2) and peroxide value (1.6–2.4 mequiv/kg of oil). The citrus seed oils mainly consisted of linoleic acid (36.1–39.8%). Other prominent fatty acids were palmitic acid (25.8–32.2%), oleic acid (21.9–24.1%), linolenic acid (3.4–4.4%), and stearic acid (2.8–4.4%). The contents of tocopherols (α, γ, and δ) in the oil were 26.4–557.8, 27.7–84.1, and 9.1–20.0 mg/kg, respectively. The results of the present study demonstrated that the seeds of citrus species investigated are a potential source of valuable oil which might be utilized for edible and other industrial applications.
Counting Difficulties: Retained Instruments, Sponges, and Needles
Authors: Jackson Sarah , Brady Sharon
Published: February 2008

PATIENTS IN WHOM A SPONGE or instrument is left after surgery may suffer complications including pain, infection, abscess, or intestinal obstruction.

CONSEQUENCES OF RETAINED ITEMS for surgical team members may include malpractice lawsuits and adverse actions from the National Practitioner Data Bank and state licensing board.

ADHERENCE TO AORN recommended practices for counting and facility counting policies can protect both patients and practitioners. AORN J 87 (February 2008) 315‐321. © AORN, Inc, 2008.
Preparation of Adolescents for Outpatient Surgery: Using an Internet Program
Authors: O'Conner‐Von Susan
Published: February 2008

THIS STUDY COMPARED the effectiveness of an Internet‐based method with a standard method for preparing adolescent patients scheduled for out‐patient tonsillectomy procedures.

A TWO‐GROUP EXPERIMENTAL DESIGN compared adolescents' state anxiety, knowledge acqui‐sition, postoperative pain intensity, and satisfaction with the method of preoperative preparation.

PARENTS' STATE ANXIETY and satisfaction with their child's preparation method also were compared.

DATA ANALYSIS REVEALED significantly increased knowledge acquisition and satisfaction among adolescents who were assigned to the Internet method of preparation and increased satisfaction among their parents. AORN J 87 (February 2008)374–398. © AORN, Inc, 2008.
Improving Compliance With Occupational Safety and Health Administration Standards
Authors: Cuming Richard G. , Rocco Tonette S. , McEachern Adriana G.
Published: February 2008

HEALTH CARE FACILITIES can be dangerous places. The mission of the Occupational Safety and Health Administration (OSHA) is to improve the safety of the American workplace by developing and implementing standards that prevent occupational injury, illness, and death.

PERIOPERATIVE SERVICES are performed in environments where exposure to bloodborne pathogens is a daily occurrence, making implementation and compliance with OSHA standards very important.

EMPLOYEES AND EMPLOYERS must remain current with workplace safety requirements, including use of personal protective equipment. This article presents implications of the OSHA standards for employers, educators, and employees. AORN J 87 (February 2008) 347‐356. © AORN, Inc, 2008.
Pursuing Cleanliness in a Field Surgical Environment
Authors: Stevenson Kevin , Cather Charles
Published: February 2008

PERIOPERATIVE MILITARY NURSES often are faced with the challenge of providing a clean surgical milieu in environments that are decidedly hostile to cleanliness.

THE COMBINATION of temperature extremes, blowing sand, dirt, mud, infection vectors, and the nature of battlefield wounds thwart the best intentions of maintaining cleanliness.

MITIGATING THESE PROBLEMS requires setting priorities, teamwork, a rigorous daily regimen of cleaning, and a willingness to make improvements as opportunities become available.
Political Efficacy and Participation in Twenty-Seven Democracies: How Electoral Systems Shape Political Behaviour
Authors: KARP JEFFREY A , BANDUCCI SUSAN A
Published: February 2008

Advocates of proportional representation (PR) often cite its potential for increasing citizen involvement in politics as one of PR's fundamental advantages over plurality or first-past-the-post systems. The assumption is that plurality electoral systems distort the translation of votes into seats, discouraging and alienating small party supporters and other political minorities. In contrast, PR systems are believed to provide greater opportunities for representation which are assumed to instil greater efficacy and increase participation. We examine this theory linking institutions to electoral participation across a diverse set of countries using data from the Comparative Study of Electoral Systems. Using a multi-level approach we find evidence consistent with the expectations about the negative influence of disproportional systems on political minorities. Voters are also likely to have stronger partisan preferences in PR systems, which enhances political efficacy and increases voter participation. The effects of PR, however, are not all positive; broad coalitions, which are likely to be a feature of these systems, reduce political efficacy.
Recent Economic Perspectives on Political Economy, Part I
Authors: DEWAN TORUN , SHEPSLE KENNETH A
Published: February 2008

In recent years some of the best theoretical work on the political economy of political institutions and processes has begun surfacing outside the political science mainstream in high quality economics journals. This two-part article surveys these contributions from a recent five-year period. In Part I, the focus is on elections, voting and information aggregation, followed by treatments of parties, candidates and coalitions. In Part II, papers on economic performance and redistribution, constitutional design, and incentives, institutions, and the quality of political elites are discussed. Part II concludes with a discussion of the methodological bases common to economics and political science, the way economists have used political science research, and some new themes and arbitrage opportunities.
The complex relationships between executive functions and positive
symptoms in schizophrenia
Authors: Guillem F. , Rinaldi M. , Pampoulova T. , Stip E.
Published: February 2008

Background

Relationships between performance on various tests of executive functions and
positive symptoms, especially delusions and hallucinations, have not been
found consistently. This may be related to method of rating symptoms, to
possible interactions between them, as well as to the low specificity of the
cognitive test measures used. In this study, we have investigated the
relationships between different aspects of positive symptomatology and
several executive subprocesses.

Method

Stable schizophrenia patients (n=96) were assessed for disorganization,
delusion and hallucination symptoms rated from the Scale for Assessment of
Positive Symptoms and the Scale for Assessment of Negative Symptoms.
Interference sensitivity, inhibition and flexibility were assessed using the
Wickens paradigm. The relationships between symptom dimensions as well as
with cognitive and other potentially confounding variables were assessed
using Pearson correlations and (simple and partial)
stepwise regressions.

Results

Generally consistent with the cognitive constructs used to account for
positive symptoms, the results indicated relationships between delusions,
disorganization and inhibition, and between hallucinations and interference
sensitivity. However, these relationships appeared more complex than
expected, with some being dependent on interactions between symptoms.

Conclusions

These results suggest: (i) that the global
measures usually employed may not be appropriate for demonstrating specific
relationships between symptoms and executive functions and
(ii) that it is necessary to take into account the
interactions between positive symptoms as well as with other factors to
reveal these relationships.
Early childhood adversity and adolescent depression: the mediating role of continued stress
Authors: Hazel N. A. , Hammen C. , Brennan P. A. , Najman J.
Published: February 2008

Background

While various conceptualizations of the link between childhood adversity and later depression have been offered, most have not accounted for the possibility that early adversity predicts continuing stress proximal to depression onset. Thus, the present study tested the possible mediating role of recent stress in the association between early adversity and depression in late adolescence.

Method

Study questions were examined in a longitudinal community sample of 705 youth who were contemporaneously assessed for early adversity exposure prior to age 5 years, chronic and episodic stress at age 15 years, and major depression prior to age 15 years and between 15 and 20 years.

Results

Total youth stress burden at age 15 years mediated the effect of early adversity on depression between ages 15 and 20 years, and none of the observed relationships were moderated by onset of depression prior to age 15 years.

Conclusions

These findings suggest that continued stress exposure proximal to depression onset largely accounts for the association between early adversity and depression in late adolescence. Intervention should thus focus on disrupting the continuity of stressful conditions across childhood and adolescence. Future studies of the neurobiological and psychosocial mechanisms of the link between early experiences and depression should explore whether the effects of early experiences are independent of continuing adversity proximal to depressive onset.
Préface: Le français à la lumière des corpus
Authors: DURAND JACQUES
Published: February 2008

Il y a encore quelques années, un numéro du Journal of French Language Studies sur le thème de ce numéro spécial aurait exigé une introduction détaillée justifiant une approche fondée sur les corpus et la comparant systématiquement à une approche jugée plus traditionnelle. De fait, la situation a fortement évolué sur le plan national et international. On ne compte plus les ouvrages, les articles, les revues, les numéros spéciaux de revues consacrés aux corpus en linguistique. Ce numéro spécial ne saurait donc prétendre à une singularité qui le détacherait comme figure sur un fond sans valeur. Il n'en offre pas moins une perspective très intéressante. Tout d'abord, même si la plupart des linguistes s'accordent pour reconnaître une valeur heuristique aux corpus et pour saluer l'importance de données qualitatives et quantitatives plus fiables, tous ne sont pas d'accord sur le type de linguistique à construire. L'article de Bernard Laks, ‘Pour une phonologie de corpus’, se refuse à considérer que les linguistiques de corpus ne sont rien d'autre que de simples dispositifs techniques au service d'une linguistique descriptive, empirique ou herméneutique. En offrant une perspective sur la longue durée, il réanalyse l'opposition classique entre sciences de l'exemplum et sciences du datum, et cherche à démontrer que la linguistique, et singulièrement la phonologie, se sont construites, contre la grammaire, comme des sciences empiriques ayant pour objet la modélisation des observables linguistiques. Comprendre l'ancienneté de la notion de corpus et savoir construire son historicité permettent à ses yeux de frayer le chemin d'une linguistique de la parole, condition sine qua non, comme Saussure l'a souvent dit d'une linguistique de la langue.
Kugmallit Valley as a conduit for cross‐shelf exchange on the Mackenzie Shelf in the Beaufort Sea
Authors: Williams William J. , Melling Humfrey , Carmack Eddy C. , Ingram R. Grant
Published: February 2008

Kugmallit Valley spans the midsection of a transect across the Mackenzie Shelf of the Beaufort Sea. Its greatest relief is 20 m, and its width is 20 km. Using a yearlong record of ice drift, ocean current, temperature, and salinity acquired near the center of the valley, we describe a pattern of flow that is correlated with wind stress and ice motion and discuss its similarity to flow within larger submarine canyons that cut through the shelf break. As in such canyons, there is enhanced cross‐shelf transport within Kugmallit Valley during upwelling‐favorable surface stress. The data also document the down‐valley flow of dense water from a flaw lead.
Effective reaction parameters for mixing controlled reactions in heterogeneous media
Authors: Luo Jian , Dentz Marco , Carrera Jesus , Kitanidis Peter
Published: February 2008

Sound understanding of mixing‐controlled reactions in heterogeneous media is needed for the realistic modeling of contaminant transport in aquifers and is a precondition for the evaluation of natural attenuation processes, the design of nuclear waste disposal, and the engineered remediation of contaminated sites. In this work, we study the bimolecular dissolution‐precipitation equilibrium reaction, adapted after De Simoni et al. (2005). Because of advective and dispersive transport of the reacting species, the system is globally in nonequilibrium because the effective reaction rate is limited by the finite rate of transport and thus is affected by the heterogeneity of the formation. We study the macroscopic formulation of such a reactive transport system in terms of mixing‐controlled reaction parameters which integrate the impact of spatial heterogeneity. The apparent chemical saturation is found to be a function of the concentration variance and is generally greater than its local‐scale equivalent. This explains why water samples taken from pumping wells are normally nonequilibrium with respect to minerals existing in the aquifer, even when local equilibrium is to be expected. The reaction rate is given by the product of a reaction factor, associated with the local equilibrium constant and concentration variance, and a mixing factor, which is the product of the microdispersion coefficient and the square gradient of the mean and perturbation concentration fields. The mixing factor dominates the description of the reaction rate in the upscaled macroscopic models. The reaction rate predicted by macroscopic models is controlled by two competing effects: The large heterogeneity‐induced macrodispersion coefficient leads to an increase of reaction rate, while a more smoothed concentration gradient may lead to a decrease of the reaction rate. Macroscopic models may only give a good approximation at large time and away from the plume center of mass because of the balanced variance budget but significantly underestimate reaction rate near the plume center because of the smoothed concentration gradient field. In fact, in an application example, reaction rate is maximum around the plume center, where a homogeneous equivalent medium would predict zero rates.
Magnetostatic interactions in deep‐sea sediments inferred from first‐order reversal curve diagrams: Implications for relative paleointensity normalization
Authors: Yamazaki Toshitsugu
Published: February 2008

Understanding magnetostatic interactions in sediments is important for paleomagnetism and rock magnetism. Magnetostatic interactions are known to affect significantly the efficiency of anhysteretic remanent magnetization (ARM) acquisition, and hence the ratio of ARM susceptibility (χARM) to saturation isothermal remanent magnetization (SIRM), a magnetic grain‐size proxy widely used for environmental applications, can be controlled by magnetostatic interactions. Relative paleointensity estimations may also be influenced by magnetostatic interactions because ARM is often used as a normalizer to correct for the difference in magnetizability of sediments. In this study, characterization of magnetic grains in deep‐sea sediments from the North Pacific Ocean was conducted using first‐order reversal curve (FORC) diagrams and IRM acquisition curves. The FORC diagrams indicate that the magnetic grains consist mainly of a noninteracting single‐domain (SD) component and an interacting SD component, and additionally of a multidomain (MD) component. The relative abundances of these components were semiquantitatively estimated by curve fitting of cross sections along a line parallel to the axis of local interaction fields (Hu) and through a peak in the coercivity (Hc). Three components were fitted assuming a Gaussian distribution of interaction fields (Hu). The IRM acquisition curves can be described by two dominant components assuming a log‐Gaussian distribution. The mean coercivities of the two components are ∼40 and ∼100 mT, respectively. It is estimated that the former component is carried by biogenic magnetite, and roughly corresponds to the noninteracting SD component derived from the FORC diagrams, and that the latter component is carried by eolian maghemite, corresponding to the interacting SD component. The χARM/SIRM ratio decreases with increasing concentration of the interacting SD component. This implies that the χARM/SIRM ratio is significantly affected by magnetostatic interactions and that it does not necessarily reflect magnetic grain size. The effect of magnetostatic interactions on natural remanent magnetization acquisition in sediments is not well understood, but if it is similarly sensitive to the SIRM, normalization by ARM in relative paleointensity estimations would overcompensate for the concentration of magnetic grains and cause the significant coherence between the normalized intensity and the normalizer that has been reported in the literature.
Unexpected rapid decrease in phase velocity of submeter Farley‐Buneman waves with altitude
Authors: Kagan L. M. , Kissack R. S. , Kelley M. C. , Cuevas R.
Published: February 2008

An unexpected and drastic drop in the phase velocity Vph of Farley‐Buneman (FB) waves with increasing altitude was observed in the equatorial electrojet over Jicamarca. The effect was detected with the newly employed 430‐MHz radar looking vertically. The decrease in Vph was 67 m/s and 36 m/s over 2.4 km for the FB waves moving towards and away from the radar, respectively. By contrast, the 430‐MHz data from 20° west displayed little dependence on altitude. Simultaneous observations with a 50‐MHz radar at 23° and 51° west also displayed little change of Vph with altitude. We show that electron inelastic cooling which defines gradual transition from super‐adiabatic to isothermal processes at 50 MHz (used in majority of observations), becomes unimportant at higher frequencies. The effect is evinced at radar frequencies ≥150 MHz and requires altitude resolution <2 km to be observed. Averaging over >7 km at oblique incidence masks the effect.
Sublimation‐driven erosion on Callisto: A landform simulation model test
Authors: Howard Alan D. , Moore Jeffrey M.
Published: February 2008

Callisto's landscape exhibits widespread erosion from some non‐impact‐induced process, which is characterized by smooth, undulating dark albedo surfaces with isolated high albedo knobs that are remnants of crater rims. We develop a landform simulation model that incorporates sublimation erosion of exposed bedrock on crater walls, composed of ice‐cemented dust, with non‐linear mass wasting of the released dust and redeposition of the ice on convex summits. The model reproduces the essential elements of landscapes on Callisto, and lends strong support to the 1999 hypothesis of Moore and his colleagues that volatile sublimation causes slope‐forming bedrock disaggregation and subsequent mass wasting while reprecipitation caps and armors local crests with frost.
Dust haze in Valles Marineris observed by HRSC and OMEGA on board Mars Express
Authors: Inada A. , Garcia‐Comas M. , Altieri F. , Gwinner K. , Poulet F. , Bellucci G. , Keller H. U. , Markiewicz W. J. , Richardson M. I. , Hoekzema N. , Neukum G. , Bibring J.‐P.
Published: February 2008

We present analysis of a bright haze observed inside Valles Marineris, which formed in mid northern spring. The data were collected by the High Resolution Stereo Camera (HRSC) and the imaging spectrometer, Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité (OMEGA), aboard Mars Express. This study provides a case example of the power of simultaneous multiple emission angle and hyperspectral imaging for study of aerosols and clouds in the Martian atmosphere. The haze appeared thinner after three days and disappeared in nine days. It was limited to a 2‐km layer at the bottom of the canyon. The color was redder than the underlying surface. The analysis of the OMEGA spectra indicates that this haze was composed of dust particles. The dust layer appeared brighter with the HRSC stereo channels than the nadir channel due to longer scattering paths. We have estimated the optical depth of the haze by fitting both HRSC and OMEGA data with radiative transfer calculations. The retrieval of the optical depth is very sensitive to the aerosol scattering model used and the reflectance of the surface. Applying an aerosol scattering model derived from sky surveys at a constant elevation by the Imager for Mars Pathfinder, the optical depth of the haze is estimated from HRSC data to be within 1.7 to 2.3 at the wavelength (λ) of 0.675 μm. The wavelength dependence is obtained from OMEGA spectrum. It increases to 2.2–2.6 at λ = 1.35 μm and moderately decreases to 1.2–1.8 at λ = 2.4 μm.
Effect of hyperglycemia on inflammatory markers in patients with Type 2 Diabetes
Authors: Goyal Rajeev , Faizy Abul , Islam Najmul
Published: February 2008

The role of inflammation in causation of both Diabetes and its complications has gained acceptance. Initially, hyperglycemia was thought to be the factor causing inflammation, but recently, obesity has gained attraction as probable cause of inflammation. We have studied the levels of markers of inflammation in Diabetic patients, with uncontrolled hyperglycemia, before and after treatment. The results indicate that hyperglycemia significantly causes increase in inflammatory markers like TNF-α and IL-6, which further contribute to pathogenesis of Diabetes mellitus type 2 as well as its complications such as atherosclerosis and neuropathy.
Two-parameter model predictions and θ-point crossover for linear-polymer solutions
Authors: Caracciolo Sergio , Mognetti Bortolo Matteo , Pelissetto Andrea
Published: February 2008

We consider the first few virial coefficients of the osmotic pressure, the radius of gyration, the hydrodynamic radius, and the end-to-end distance for a monodisperse polymer solution. We determine the corresponding two-parameter model functions which parametrize the crossover between the good-solvent and the ideal-chain behavior. These results allow us to predict the osmotic pressure and the polymer size in the dilute regime in a large temperature region above the θ point.