bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of fluorotelomer alcohols by liquid chromatography/tandem mass spectrometry in water
Authors: Szostek Bogdan , Prickett Keith B. , Buck Robert C. 
Published: August 2006

AbstractFluorotelomer alcohols (FTOHs) are important polyfluorinated raw materials that belong to the general category of perfluoroalkyl substances (PFAS). PFAS, including perfluoroalkyl carboxylates (PFCAs) and perfluoroalkyl sulfonates, have recently attracted considerable attention because they are persistent and found globally in the environment. FTOHs are precursors that may degrade in the environment to PFCAs. The development of analytical methods for determination FTOHs in environmental samples is necessary to determine the environmental presence of FTOHs. This work presents the development and validation of a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the determination of FTOHs (6‐2, 8‐2, 10‐2) in aqueous samples. Chromatographic conditions were optimized in order to obtain focused FTOH chromatographic peaks. The mobile phase and mass spectrometric conditions were optimized to enable formation of deprotonated FTOH molecules in the negative ion electrospray mode. Two extraction methods were investigated using acetonitrile and methyl tert‐butyl ether (MTBE). These methods were validated for a range of environmental water samples fortified with FTOHs at three different levels. Both extraction methods resulted in recoveries from 70 to 120%. Detection limits of FTOHs were estimated to be approximately 0.09 ng/mL for LC/MS/MS detection. An LC/MS method was also developed for FTOH determination with an estimated 1.2 ng/mL limit of detection. Various sample storage scenarios were investigated. It was determined that the aqueous samples of FTOHs are best preserved by storing them frozen in sealed vials with aluminum foil lined septa. Copyright © 2006 John Wiley & Sons, Ltd.
Using δ15N values to characterise the nitrogen nutrient pathways from intensive animal units
Authors: Skinner R. A. , Ineson P. , Jones H. , Sleep D. , Rank R. 
Published: August 2006

AbstractPrevious studies on foliar δ15N values, in certain bryophytes, have indicated signature similarities to source pollutants. The object of this study was to investigate the effect further, by examining the mechanisms whereby isotopic fractionation occurs in systems such as atmospheric ammonia (NH3), throughfall, vegetation and soil. Measurements taken in and around point emission sources will then be used to characterise the various fractionation effects associated with these N transformations, as well as to demonstrate some of the issues associated with using δ15N values as pollution indicators. The atmospheric dispersion model UK‐ADMS has also been used to model atmospheric δ15NH3 emissions, with signatures exhibiting marked negative shifts immediately downwind of an agricultural NH3 source. Similar dispersion patterns were mapped for NH3 concentration data illustrating the link between these two forms of measurement. Copyright © 2006 John Wiley & Sons, Ltd.
Niche width revisited: organizational scope, behavior and performance
Authors: Sorenson Olav , Mcevily Susan , Ren Charlotte Rongrong , Roy Raja 
Published: August 2006

AbstractAlthough strategy research typically regards firm scope as a positional characteristic associated with performance differences, we propose that broad contemporary scope also provides insight into the routines that govern firm behavior. To attain broad scope, firms must repeatedly explore outside the boundaries of their current niche. Firms with broad niches therefore operate under a set of routines that repeatedly propel them into new market segments, expanding their niche. These niche expansions, however, involve risky organizational changes, behavior that disadvantages generalists relative to specialists, despite the positional value of broad scope. Empirical analyses of machine tool manufacturers and computer workstation manufacturers support this conjecture: (i) generalists introduce new products at a higher than optimal rate, thereby increasing their exit rates; and (ii) generalists also more frequently launch new models with novel features or targeted at new consumer segments rather than improving only incrementally on existing products, further accelerating their odds of failure. After adjusting for these behavioral differences, broad niche widths reduce exit rates, suggesting that they provide positional advantages. The paper discusses how this phenomenon may help to explain the diversification and multi‐nationality discounts. Copyright © 2006 John Wiley & Sons, Ltd.
Reference data representative of normal findings at three‐dimensional power Doppler ultrasound examination of the cervix from 17 to 41 gestational weeks
Authors: Rovas L. , Sladkevicius P. , Strobel E. , Valentin L. 
Published: August 2006

AbstractObjectivesTo develop normal reference ranges for cervical volume and vascular indices using three‐dimensional (3D) power Doppler ultrasonography from 17 to 41 gestational weeks.MethodsThis was a cross‐sectional study of 352 nulliparous and 291 parous women who delivered at term and underwent transvaginal 3D power Doppler ultrasound examination of the cervix once at 17 to 41 weeks' gestation. We examined approximately 25 women in each gestational week. Cervical volume, vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were calculated.ResultsThere was no change in cervical volume between 17 and 40 weeks' gestation. At 41 weeks cervical volume was slightly smaller than it was at 17–40 weeks (P = 0.03 for nulliparous women and P = 0.08 for parous women). The cervical volume was larger in parous than it was in nulliparous women (median 38 cm3 vs. 32 cm3 at 17–40 weeks, P < 0.0001; median 31 cm3 vs. 22 cm3 at 41 gestational weeks, P = 0.288). FI did not differ between nulliparous and parous women and remained unchanged between 17 and 41 weeks' gestation (median 30.6, range 21.2–55.2). VI and VFI did not change consistently from 17 to 41 weeks, but the values were higher in parous than they were in nulliparous women at 17–30 weeks (median VI 5.3% vs. 3.1%, P < 0.0001; median VFI 1.6 vs. 0.9, P < 0.0001). At 31–41 gestational weeks the median VI for all women irrespective of parity was 4.9% and the median VFI was 1.4.ConclusionReference values for cervical volume and blood flow indices as assessed by 3D power Doppler ultrasonography have been established for the second half of pregnancy. These lay the basis for studies of pathological conditions. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Traffic‐aware routing for real‐time communications in wireless multi‐hop networks
Authors: Yin Shouyi , Xiong Yongqiang , Zhang Qian , Lin Xiaokang 
Published: August 2006

AbstractIn this paper, we propose a novel traffic‐aware routing metric for real‐time communications (RTC) in wireless multi‐hop networks. Our routing metric, path predicted transmission time (PPTT), is designed to choose a high‐quality path for RTC flow between a source and a destination. PPTT can serve as both single‐radio and multi‐radio routing metric for RTC flow.RTC has critical quality of service (QoS) requirements in terms of delay, bandwidth and so on. Traditional measurement‐based routing schemes ignore the interference from the coming RTC flow itself (i.e. self‐traffic), so they may choose the inefficient path to serve the coming RTC flow due to the inaccurate quality estimation of the transmission path. PPTT takes explicit consideration of both self‐traffic and neighbouring traffic interfering with the RTC flow, and thus offers an accurate estimation of path transmission delay. Through differentiating the links by the wireless channel/radio they are using, PPTT has the capability to choose a high‐quality path for the coming RTC flow in both single‐radio and multi‐radio networks.To evaluate the performance, we implement PPTT scheme and study its performance in a wireless multi‐hop testbed consisting of 32 nodes equipped with two IEEE 802.11a/b/g combo cards, and we also conduct extensive simulations with different random topologies in network simulator NS‐2 for a more comprehensive comparison. The results of simulation and experiment show that this routing metric outperforms other non‐traffic‐aware one such as expected transmission count (ETX) and weighted cumulative expected transmission time (WCETT) in terms of delay and goodput in both single‐radio and multi‐radio wireless networks. Copyright © 2006 John Wiley & Sons, Ltd.
Distributed medium access control for wireless mesh networks
Authors: Cheng Ho Ting , Jiang Hai , Zhuang Weihua 
Published: August 2006

AbstractWireless mesh networking is an emerging technology for future broadband wireless access. The ad hoc manner of wireless mesh networks (WMNs) determines that distributed medium access control (MAC) protocols are desired. Multimedia traffic with heterogeneous quality of service (QoS) requirements is expected to be supported in small‐, medium‐, and large‐scale WMNs. Wireless mesh routers in WMNs are located in fixed sites with low (or no) mobility and no power constraints, thus comprising a robust and reliable wireless mesh backbone. Different networking characteristics between the mesh backbone and various mesh client networks give rise to the demand of heterogeneous MAC design. Due to new design purposes and new networking structures, existing MAC protocols designed for mobile ad hoc networks may not be effective or efficient for multi‐purpose WMNs. This paper provides an overview of distributed MAC protocols based on their underlying design objectives and methodology, discusses their features and suitability for WMNs, and identifies potential challenges and open research issues. Copyright © 2006 John Wiley & Sons, Ltd.
Impact of Bluetooth MAC layer on the performance of TCP traffic
Authors: Mišić Jelena , Chan Ka Lok , Mišić Vojislav B. 
Published: August 2006

AbstractRecent updates of the Bluetooth specification have introduced significant changes in the Bluetooth protocol stack, including optional flow control. When the Bluetooth piconet is used to carry TCP traffic, complex interactions between TCP congestion control mechanisms and data link layer controls of Bluetooth will occur. In this paper, we model the performance of the piconet with TCP traffic, expressed through segment loss probability, round‐trip time, and goodput, through both probabilistic analysis and discrete‐event simulations. We show that satisfactory performance for TCP traffic may be obtained through proper dimensioning of the Bluetooth architecture parameters. Copyright © 2006 John Wiley & Sons, Ltd.
Measurement of background components in wavelength dispersive X‐ray fluorescence spectrometry
Authors: Verkhovodov Petro O. 
Published: August 2006

AbstractThree components of the background have been investigated: first, characteristic radiation of the lamellas of the collimator excited by secondary x‐ray beam; second, secondary x‐ray beam scattered by the lamellas of the collimator; third, diffusive and incoherent scattering of the secondary x‐ray beam by the focusing crystal. The relationships between chemical content of the specimen and the intensity of the first and the second components were determined by a wavelength‐dispersive x‐ray spectrometer that has an energy‐dispersive x‐ray detector. The intensity of the third component was very low. It was not found in this experiment. Copyright © 2006 John Wiley & Sons, Ltd.
Biological control: lessons from a study of California red scale
Authors: Murdoch William W. , Swarbrick Susan L. , Briggs Cherie J. 
Published: August 2006

AbstractA 20‐year study of suppression of California red scale, a world‐wide pest of citrus, by the parasitoid Aphytismelinus has established that the interaction is dynamically stable and that the mechanisms leading to control and stability operate at a local scale: spatial processes are not important. Key features appear to be an invulnerable class in the pest and rapid development of the parasitoid compared with the pest, as well as the fact that the parasitoid is an in situ specialist on the pest. Although another parasitoid species and two predator species are also present, they play at most a negligible role in pest control. These features—long‐term persistence, suppression by a single natural enemy, an invulnerable stage in the pest and rapid development in the natural enemy—appear to be common in other coccid pest systems. By contrast, in temporary crops where the pest and enemy populations are open (i.e., sustained over the long run mainly by immigration) and non‐persistent locally, as is frequently found in aphid pests, we expect that multiple generalist enemies are required for control and, of course, that spatial processes are important. There are very few well‐studied examples of such systems, but these support our expectations. In these cases, it also appears that neither rapid enemy development nor an invulnerable pest stage is important for successful control.
Overgrazing and soil carbon dynamics in eastern Inner Mongolia of China
Authors: Zou Chunjing , Wang Kaiyun , Wang Tianhou , Xu Wenduo 
Published: August 2006

AbstractEastern Inner Mongolia of China is a typical ecotone between sandy forests and steppe. Little is known about the effect of overgrazing on carbon loss from soil in semiarid steppe and sandy forests of the north of China. The soil carbon parameters were measured in a 10,000 ha natural reserve in eastern Inner Mongolia of China (43°30′–43°36′N, 117°06′–117°16′E). Three situations were compared: primary protected (PP), moderately protected (MP) and highly degraded (HD). Soil and litter samples were recovered in spring and summer. Soil organic carbon (SOC) and CO2–C values decreased from the PP (9.23 kg m−2and 157 g m−2) to the HD (1.69 kg m−2and 57 g m−2) sites whereas the C mineralization rate increased toward the less restored sites (1.06–2.37). Surface‐litter C was different in both sites under protection (PP 648 and MP 408 g m−2), an was low at the HD site (17 g m−2). Leaves from woody species dominated the surface litter at the PP site, whereas grass material was predominant at the MP site. During summer, both CO2–C and SOC decreased, whereas the C mineralization rate increased. We calculated that C loss since the introduction of cattle into the forest was 77 M g ha−1, reaching a total of 1.1×1015g for eastern Inner Mongolia. These values are higher than those caused by the conversion of steppe and other ecosystems into agriculture or cultivated pastures. The amount of C fixed at the PP site (650 g ha−1year−1) indicates that the sandy soils have a significant potential as atmospheric carbon sinks.
Spatial patterns of foliar stable carbon isotope compositions of C3 plant species in the Loess Plateau of China
Authors: Zheng Shuxia , Shangguan Zhouping 
Published: August 2006

AbstractThe spatial pattern of foliar stable carbon isotope compositions (δ13C) of dominant species and their relationships with environmental factors in seven sites, Yangling, Yongshou, Tongchuan, Fuxian, Ansai, Mizhi and Shenmu, standing from south to north in the Loess Plateau of China, was studied. The results showed that in the 121 C3 plant samples collected from the Loess Plateau, the foliar δ13C value ranged from −22.66‰ to −30.70‰, averaging −27.04‰. The foliar δ13C value varied significantly (P<0.01) among the seven sites, and the average δ13C value increased by about 1.69‰ from Yangling in the south to Shenmu in the north as climatic drought increased. There was a significant difference in foliar δ13C value among three life‐forms categorized from all the plant samples in the Loess Plateau (P<0.001). The trees (−26.74‰) and shrubs (−26.68‰) had similar mean δ13C values, both significantly (P<0.05) higher than the mean δ13C value of herbages (−27.69‰). It was shown that the trees and shrubs had higher WUEs and employed more conservative water‐use patterns to survive drier habitats in the Loess Plateau. Of all the C3 species in the Loess Plateau, the foliar δ13C values were significantly and negatively correlated with the mean annual rainfall (P<0.001) and mean annual temperature (P<0.05), while being significantly and positively correlated with the latitude (P<0.001) and the annual solar radiation (P<0.01). In general, the foliar δ13C values increased as the latitude and solar radiation increased and the rainfall and temperature decreased. The annual rainfall as the main influencing factor could explain 13.3% of the spatial variations in foliar δ13C value. A 100 mm increment in annual rainfall would result in a decrease by 0.88‰ in foliar δ13C values.
Hypospadias Repair in the 1990s
Authors: Ellsworth P. , Cendron M. , Ritland D. , McCullough M. 
Published: August 2006

ABSTRACTHypospadias is a congenital anomaly in which the urethral meatus is abnormally located anywhere from the glans to the perineum. Refinements in pediatric anesthesia, surgical technique and instrumentation, and a greater understanding of the psychologic and emotional issues related to hypospadias repair have led to this procedure being performed at an earlier age. The goal of reconstruction is to bring the urethral meatus to the tip of the penis, to correct associated penile curvature if present, to create a conical‐shaped glans, and to achieve cosmetically acceptable penile shaft skin coverage. The surgical technique employed varies with the penile anatomy and surgeon's preference. Complications may occur both immediately and long after the surgical procedure, and thus follow‐up is necessary. AORN J 69 (Jan 1999) 148–161.
Taking the Mystery Out of Ureteroscopy
Authors: Brownlee Nancy 
Published: August 2006

ABSTRACTUreteroscopy can be one of the more challenging procedures performed in the urology department. For perioperative nurses who rotate through the urology department and are not familiar with the various stents, wires, baskets, and other specialty equipment, the procedure is not only challenging, but also mysterious. This article enhances nurses' knowledge of urology by describing the steps and equipment of ureteroscopy, including access (ie, using wires, ureteral catheters, and specialty catheters); dilation (ie, using balloons, self‐dilating scopes, and sequential and coaxial dilation); manipulation (ie, using baskets, graspers, biopsy devices, and intracorporeal lithotripsy equipment); and stenting (ie, using multilength or pigtail stents). Knowledge of these factors can help clear up the mystery of ureteroscopy, allowing nurses to better understand the procedure and better manage its complex inventory. AORN J 69 (Jan 1999) 162–171.
Phototherapeutic Keratectomy
Authors: Gill Kuljit S. , Sitbon Jean‐Robert R. , Trocmé Stefan D. 
Published: August 2006

ABSTRACTThe US Food and Drug Administration recently approved the 193‐nm excimer laser for the treatment of superficial corneal pathology and surface irregularities—a procedure called phototherapeutic keratectomy (PTK). Indications for PTK include corneal dystrophies, degenerations, and scars that impair corneal transparency, thus compromising visual acuity. In some cases, PTK may offer a better treatment modality than corneal transplant surgery. This article reviews the basic fundamentals of PTK, including indications for surgery, the surgical procedure, preoperative and postoperative patient evaluation and care, and possible complications. AORN J 66 (Aug 1997) 242–252.
Surgical Treatment of Dacryocystitis
Authors: McEwen Donna R. 
Published: August 2006

ABSTRACTDacryocystitis is a common infection of the lacrimal sac. In adults, dacryocystitis results from an obstruction (ie, dacryostenosis) of the nasolacrimal duct. Dacryocystitis can be either an acute or chronic infection, and both forms usually are unilateral in nature. The hallmark symptom of both forms of dacryocystitis is epiphora (ie, excessive tearing). An obstruction of the lacrimal duct also can cause dacryocystitis. This article discusses the surgical treatment of dacryocystitis and provides a case study that illustrates perioperative nursing care of a patient who required surgical treatment of this lacrimal duct disorder. AORN J 66 (Aug 1997) 268–280.
New Instrumentation Allows for Removal of Nonpalpable Breast Lesions
Authors: Boshaw Doris L. 
Published: August 2006

ABSTRACTBreast cancer is the second leading cause of cancer deaths in women. Approximately 90% of breast cancer is curable if it is diagnosed and treated early. Increasingly, women are participating in mammographic screenings, which result in earlier detection of non‐palpable lesions. In the past, surgical removal was not an option for small lesions, and frequent mammographic monitoring was required until patients' lesions were large enough for needle core biopsies or needle localization for open surgical biopsies. Technology now has combined stereotactic imaging with a minimally invasive biopsy system for removal of these nonpalpable lesions. This capability for accurate early diagnosis and intervention is essential in improving patients' survival rates. AORN J 66 (Aug 1997) 296–302.
Computerization in the OR
Authors: Bird Lavern J. 
Published: August 2006

ABSTRACTThis article highlights the process of establishing a computerized scheduling and materials management system in a surgical department. The following facets of the computerization process are discussed: options staff members should consider when choosing a computer system, the importance of scheduling and inventory control, cost savings, how computer systems work when using electronic data interchange and bar coding, and case studies. AORN J 66 (Aug 1997) 312–317.
Instrument Design and Cross‐Infection
Authors: Muscarella Lawrence F. 
Published: August 2006

ABSTRACTThis article reviews recently reported patient‐to‐patient trans‐mission of disease during endoscopic procedures and discusses several important instrument reprocessing issues. In addition, the author offers several infection control recommendations to minimize the risk of patient infection during endoscopic procedures. AORN J 67 (March 1998) 552–556.
Mobile Surgical Transport Team
Authors: Wick J.M. , Wade J. , Datena S.J. , Long W.B. 
Published: August 2006

ABSTRACTThe “golden hour” of trauma is based on the principle that severely injured patients are more likely to survive with rapid, appropriate resuscitation and treatment. An inequality exists between sophisticated urban trauma centers and rural/community hospitals in their efforts and abilities to treat severely injured patients. A level I trauma center developed a unique program in an attempt to equalize this inequality—a mobile surgical transport team (MSTT). This article explains the origin of the MSTT, how and why the MSTT is activated, and the roles and responsibility of MSTT members. To further explain the MSTT, two contrasting case studies on trauma patients are presented. AORN J 67 (Feb 1998) 346–354.
Clinical Pathways—A Perioperative Application
Authors: Isozaki Lauren F. Fujihara , Fahndrick Julie 
Published: August 2006

ABSTRACTThe application of clinical pathways as a means of streamlining health care and tracking outcome data for continuous quality improvement has been evolving continually since the late 1980s. In order for the clinical pathway process to be effective, it must be collaborative, multidisciplinary, and have administrative support and institutional congruency. Members of a multidisciplinary work group at the University of California Los Angeles Medical Center have developed a perioperative clinical pathway for patients undergoing coronary artery bypass graft surgery. The process of developing a perioperative clinical pathway involved extensive preliminary preparation before actually designing the pathway and identifying outcome data. Ongoing reevaluation of pathway components is essential and future opportunities for expansion are apparent. AORN J 67 (Feb 1998) 376–392.