bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of vaginosonographic measurements of endometrial thickness in the identification of abnormal endometrium in peri‐ and postmenopausal bleeding
Authors: Tongsong Theera , Pongnarisorn Chailert , Mahanuphap Pongsak
Published: February 2007

One hundred and seventy seven women with peri‐ and postmenopausal bleeding were subjected to vaginosonographic examination followed by thorough pathological examination of the uterine curetting samples. A mean endometrial thickness (double layer) of 13.2 ± 3.6 mm and 8.2 ± 4.8 mm were found in those with and without histological abnormalities, respectively. Endometrial thickness of less than 7 mm, however, was found to be predictive of normal endometrium (100% sensitivity, 46% specificity) and can, therefore, be used to separate those who require diagnostic curettage from those who do not. These findings suggest that this relatively simple, noninvasive procedure can be used as a screening test for patients with peri‐ or postmenopausal bleeding. © 1994 John Wiley & Sons, Inc.
Acceleration time in normal fetal umbilical artery at term and its relationship to the cord blood hematocrit
Authors: Chang Fong‐Ming , Yao Bor‐Lin , Yu Chen‐Hsiang , Huang Soon‐Cen , Lin Yue‐Shan , Ko Huei‐Chen
Published: February 2007

The purpose of this study was to test the hypothesis that the acceleration time (AT) of the fetal umbilical artery remains constant at term for normal pregnancies. In addition, we also examined whether the AT has any correlation with umbilical cord blood hematocrit (Hct). In total, 539 normal‐term fetuses with menstrual ages (MA) ranging from 37 weeks to 42 weeks were enrolled in a cross‐sectional design. The AT of the fetal umbilical artery was measured prior to delivery using a high‐resolution, real‐time Doppler scanner. All were delivered within 2 days of the ultrasound examination. At parturition, blood from the umbilical vein was collected and the red cell indices, including the Hct, were determined. The results indicated that the mean values of AT of the umbilical artery remained constant during normal‐term pregnancies from 37 weeks to 42 weeks, menstrual age (mean: 0.104 sec, SE: 0.001 sec, n = 539). Although the AT was thought to be affected by the Hct, the AT had no correlation with umbilical venous Hct (n = 539, r = 0.002, p > 0.05). This constant value of the AT may be used as a reference for fetal physiology and perinatal medicine. © 1995 John Wiley & Sons, Inc.
Biophysical principles of vascular diagnosis
Authors: Hoeks Arnold P. G. , Reneman Robert S.
Published: February 2007

Visual inspection of the spectral composition of the Doppler signal as a function of time (sonogram) has been very helpful in detecting the presence of stenoses with substantial lumen narrowing causing abnormal flow patterns. Attempts to grade a stenosis based on the spectral width at peak systole were less successful because of the obscuring effects of the ultrasound beam width with respect to lumen diameter, dimensions of the sample volume, angle of observation, and spectral broadening due to vessel branching and bends. The introduction of color flow imaging has put emphasis on the width of the velocity distribution and the consistency of flow patterns within the region of interest. This technique requires a high resolution in space, velocity, and time necessitating the development of new velocity estimation algorithms. The observed flow patterns can be related to the echogenicity and local wall thickness of peripheral vessels. In addition, the displacement behavior of arterial walls over time provides information about the elasticity of the wall. Knowing the instantaneous velocity of arterial walls, it becomes possible to suppress selectively and adaptively the arterial wall contribution, allowing for the assessment of low blood flow velocities close to the wall and, hence, of wall shear rate. The latter development enables the study of the interaction of blood velocities and the metabolism and structure of the walls, providing possible clues for atherogenesis. © 1995 John Wiley & Sons, Inc.
Role of transvaginal sonography in the detection of endometriomata
Authors: Volpi Eugenio , De Grandis Tiziana , Zuccaro Giancarlo , Vista Antonio La , Sismondi Piero
Published: February 2007

Endometriosis is a common cause of pelvic pain and infertility in young women. Transvaginal sonography is major means for diagnosing ovarian masses. In our study, we scanned 60 patients with endometriomata who underwent laparotomy or laparoscopy. We compared preoperative ultrasonographic diagnosis with histological reports. The sonographic criteria for the diagnosis of endometriomata were (1) cystic structure with low, homogeneous echogenicity and (2) thick cystic wall with regular margins. In 50 patients, sonography suggested an endometrioma. In 47 cases, the diagnosis was correct. The false‐positive cases were all caused by cystic teratomas with a homogeneous sonographic pattern. Ten false‐negative cases were diagnosed by ultrasonography as functional ovarian cysts (5), teratomas (3), and benign ovarian cystoma (1). Only 1 case of a 5‐mm endometrioma was demonstrated by laparoscopy but not by TVS. The sensitivity of TVS for diagnosing endometriomata was 82.4% and specificity 97.7%; the positive and negative predictive values were 94% and 92.8%, respectively. The diagnostic accuracy of TVS was 93%. In our experience, TVS is a very specific means for diagnosing endometriomata when the typical pattern is detected; however, the sensitivity of the technique needs to be improved. © 1995 John Wiley & Sons, Inc.
Staging of hilar cholangiocarcinoma with ultrasound
Authors: Neumaier Carlo Emanuele , Bertolotto Michele , Perrone Rosaria , Martinoli Carlo , Loria Francesco , Silvestri Enzo
Published: February 2007

The preoperative assessment of the extent of biliary and vascular involvement by hilar cholangiocarcinoma is clinically important because resectability may be limited by tumor extension along the bile ducts into the hepatic parenchyma or to the adjacent hilar vessels. Thirty‐five patients with hilar cholangiocarcinoma were studied with ultrasound, and the results were compared with operative findings and other diagnostic modalities. The level of intrahepatic biliary obstruction was determined in 100% of patients with ductal ectasia, and a tumor mass was shown in 37.1%. Imaging and Doppler ultrasound proved accurate in detecting the neoplastic involvement of the portal vein. Both correctly diagnosed portal occlusion and wall infiltration in 4 of 4 and 15 of 18 (83%) patients, respectively, without any false‐positives. On the contrary, imaging ultrasound had poor sensitivity in detecting infiltration of the hepatic artery (43%) and metastases in regional lymph nodes (37%), liver (66%), and peritoneum (33%). In conclusion, ultrasound may be valuable in the preoperative staging of hilar cholangiocarcinoma, specially in predicting ductal and portal involvement. © 1995 John Wiley & Sons, Inc.
Color Doppler sonography: Anatomic and physiologic assessment of the thyroid
Authors: Clark Karen J. , Cronan John J. , Scola Francis H.
Published: February 2007

The purpose of this study was to assess the potential application of color Doppler sonography in thyroid imaging. Thyroid nodules and other thyroid pathology detected by color Doppler ultrasound and nuclear scintigraphy were compared in 115 patients. The majority of “cold” nodules demonstrated a peripheral rim of color flow and no internal color flow with color Doppler sonography. A large number of “hot” nodules demonstrated internal color flow. Color Doppler sonography was helpful in delineating nodules in otherwise inhomogeneous glands. We determined that color Doppler cannot reliably distinguish benign from malignant thyroid nodules; fine‐needle aspiration biopsy remains the most accurate method in differentiating benign and malignant lesions. We suggest that color Doppler sonography plays only a limited role in the evaluation of nodular thyroid disease at this time. The color Doppler appearance of other thyroid disorders (including toxic multinodular goiter, Graves' disease, and thyroiditis) is discussed. © 1995 John Wiley & Sons, Inc.
Image‐directed color Doppler ultrasonography in the evaluation of superficial solid tumors
Authors: Özbek S. Süreyya , Arkun Remide , Killi Refik , Memiş Ayşenur , Dağdeviren Aynur , Sevinç Erkan
Published: February 2007

Image‐directed color Doppler ultrasonography (ICDUS) studies of 86 patients with superficial solid masses yielded significantly lower resistive index (RI) values in acute inflammatory lesions, but no significant difference between the maximum systolic flow velocities (S) of the patient groups with malignant, benign, and acute inflammatory lesions. When analyzed separately, the malignant soft‐tissue tumor subgroup was shown to have significantly higher mean RI compared to that of the malignant node subgroup.

We conclude that RI may be useful in the differentiation of acute inflammatory masses from other pathological entities. Malignant soft‐tissue tumors, especially sarcomas, may have different Doppler features from those of carcinomatous tumors. © 1995 John Wiley & Sons, Inc.
Role of ultrasound in managing neuroblastoma detected by mass screening: A proposed ultrasonographic grading for children with neuroblastoma
Authors: Hirata Tsuneo , Tatara Hideki , Zaizen Yoshio , Suita Sachiyo , Matsuzaki Akinobu , Ueda Kohji
Published: February 2007

The ultrasonographic (US) findings of 25 infant cases detected by the Japanese mass screening program for neuroblastoma (NB) were reviewed. The following results were obtained: An identification of the primary site was possible in 96% of the cases with abdominal US. An estimation of the tumor weight was possible based on the mass volume, which was calculated from US measurements. With the combination of the estimated mass volume, local involvement, and distant metastasis, the US grading of NB was possible and closely corresponded to the surgical staging (84%). The NB cases of adrenal origin at U1a, with a mass volume of less than 16 mL, were all found to be stage I and presented the possibility for spontaneous regression. © 1995 John Wiley & Sons, Inc.
Ultrasonically guided needle biopsy of anterior mediastinal masses: Comparison of carcinomatous and non‐carcinomatous masses
Authors: Hsu Wu‐Huei , Chiang Chi‐Der , Hsu Jeng‐Yuan , Kwan Po‐Chung , Chen Chun‐Lieh , Chen Chih‐Yi
Published: February 2007

Thirty‐three patients with anterior mediastinal masses underwent percutaneous ultrasonically guided needle biopsy (UGNB), including ultrasonically guided aspiration biopsy (UGAB) in all 33 patients and ultrasonically guided cutting biopsy (UGCB) in 13 patients. Using UGAB alone, the diagnostic rate of anterior mediastinal masses was 52% (17/33); if both the UGAB and UGCB methods were used, the diagnostic rate could achieve 79% (26/33). If the anterior mediastinal masses were divided into carcinomatous (n = 15) and non‐carcinomatous (n = 18) groups, we found that the carcinomatous group was more easily diagnosed by UGAB than the non‐carcinomatous group (87% vs 22%, p < 0.01) and UGCB was more valuable and helpful than UGAB in the diagnosis of non‐carcinomatous mediastinal masses (75% vs 22%). One episode of injury to the aortic wall occurred after a UGCB. Our results show that carcinomatous mediastinal masses can be easily diagnosed by UGAB, and UGCB is often necessary in the diagnosis of non‐carcinomatous mediastinal masses. © 1995 John Wiley & Sons, Inc.
Evaluation of breast tumors with color Doppler imaging: A comparison with image‐directed Doppler ultrasound
Authors: Lee San‐Kan , Lee Tain , Lee Kuan‐Rong , Su Yeou‐Gie , Liu Tse‐Jia
Published: February 2007

Doppler ultrasound is an adjunct to other imaging modalities in differentiating benign from malignant breast tumors. Two groups of patients with breast nodules were examined using a 10/4.5 MHz (imaging frequency/pulsed Doppler frequency) image‐directed Doppler probe and a 7.0/5.0 MHz color Doppler imaging probe, separately. Whenever flow signals were detected within or at the margin of the breast nodule, the lesion was considered to be malignant. In detecting malignant breast tumors, the sensitivity was 77.3% and 94.5%, specificity 83.3% and 40.1%, accuracy 81% and 63.4% for image directed Doppler and color Doppler imaging, respectively. We found color Doppler to be easier and more efficient in detecting the flow signals of neovascularity in breast tumor. Color Doppler exhibits a higher sensitivity in detecting the malignant breast tumors. However, more false‐positive diagnoses were made. Color Doppler ultrasound also expedited the examination, and the whole procedure could be shortened from 35 minutes to 8 minutes compared with our previous examination performed by image‐directed Doppler ultrasound. Due to its higher sensitivity and saving in examination time, we use color Doppler imaging as a routine procedure when solid lesions are observed in x‐ray mammography or sonography, as a supplement to the diagnosis of breast tumors. © 1995 John Wiley & Sons, Inc.
Abdominal tuberculosis: Comparison of sonography and computed tomography
Authors: Sheikh Mehraj , Abu‐Zidan Fikri , Al‐Hilaly Moshriq , Behbehani Abdulla
Published: February 2007

Sonographic and computed tomography findings were retrospectively compared in 13 patients with proven abdominal tuberculosis who had both diagnostic modalities in their workup. The patients were treated over 9 years in two general hospitals in Kuwait. Ultrasound could detect the same findings as CT in 9 of 13 patients. Both had the same accuracy in detecting the type of ascites (in 6 patients) and solid organ tuberculosis (four lesions). Ultrasound gave useful information but could not completely replace CT as it detected less bowel thickening (3 of 5 lesions) and abdominal tuberculous lymphadenopathy (1 of 4 lesions) than CT scanning. © 1995 John Wiley & Sons, Inc.
A randomized trial of transcutaneous extraction atherectomy in femoral arteries: Intravascular ultrasound observations
Authors: Nakamura Shigeru , Conroy Robert M. , Gordon Ian L. , Deutsch Larry‐Stuart , Maheswaran Bavani , Antone Curtis S. , Tobis Jonathan M.
Published: February 2007

Objectives. The purpose of this study was to test the hypothesis that in occlusions of the superficial femoral artery, removal of atherosclerotic plaque would result in a higher long‐term patency rate compared to balloon dilatation alone. A secondary hypothesis was that long term patency would be proportional to the amount of plaque removed.

Methods. A randomized controlled study of patients with occluded superficial femoral arteries was performed comparing balloon dilatation alone versus a 2.7 mm or a larger (4.0 mm or 4.7 mm) transcutaneous extraction catheter (TEC) atherectomy device followed by balloon dilatation. The effect of these devices on plaque area was assessed directly by intravascular ultrasound imaging.

Results. The mean occlusion length was 19.4 cm ± 11.7 cm. The mean lumen area increased from 4.7 mm2 to 15.1 mm2, primarily due to balloon dilatation, but the mean atheroma area of 19.8 mm2 did not change with either size of TEC device. Although the initial procedure success rate was high (79%), the 6 month patency was only 45%. There was no difference in 6 month patency between the 3 groups.

Conclusions. The data indicate that the TEC atherectomy devices do not remove a significant amount of atherosclerotic plaque in occluded superficial femoral arteries. The 6 month patency is no different with these atherectomy devices than with balloon dilatation alone. The larger (4.0 mm or 4.7 mm) TEC device does not remove any more tissue than the smaller (2.7 mm) device. The use of intravascular ultrasound to quantitate the effects of this atherectomy device provides important insights into the mechanism of action and lack of efficacy of the TEC atherectomy catheter. © 1995 John Wiley & Sons, Inc.
Instrument design and characterization for high resolution MALDI‐MS imaging of tissue sections
Authors: Chaurand Pierre , Schriver Kenneth E. , Caprioli Richard M.
Published: February 2007

In previous work, we have reported using a MALDI imaging time‐of‐flight mass spectrometer for the detection of protein ions from tissue sections with spatial resolution of 25 µm. We present here imaging mass spectrometry results obtained with a high‐resolution scanning MALDI time‐of‐flight mass spectrometer, equipped with a coaxial laser illumination ion source, capable of achieving irradiation areas as small as 40 µm2 (ca 7 µm diameter). MALDI‐generated analyte ion signals from these very small irradiation volumes can be observed in a molecular weight range up to 27 000. High‐resolution imaging mass spectrometry images were successfully generated from matrix thin film samples and tissue sections with scanning resolutions at and below 10 µm. This work also provides fundamental characterization of the ion signal dependence as a function of various focus and fluence parameters that will be required for extension to tissue imaging at the subcellular level. Copyright © 2007 John Wiley & Sons, Ltd.
Using fossil spring deposits in the Death Valley region, USA to evaluate palaeoflowpaths
Authors: Miner R. E. , Nelson S. T. , Tingey D. G. , Murrell M. T.
Published: February 2007

Spring deposits reveal the timing and environment of past groundwater discharge. Herein, however, the potential for fossil spring deposits to infer water sources and palaeoflowpaths through trace elements and stable and radiogenic isotopes is examined.

Past discharge (70 to 285 ka) in the Tecopa Basin in the Death Valley region of southeastern California is represented by tufa deposits, including mounds, pools, cemented ledges and rare calcite feeder veins. δ18O values indicate that spring discharge was a mixture of far‐travelled (regional) water with a significant, and perhaps dominant contribution of local recharge on a nearby range front and alluvial pediment, rather than simply representing an elevated regional water table. δ13C values indicate regional water had a high TDS, whereas solute data imply low overall solute contents, consistent with dilution by a large component of local recharge.

Radiogenic isotope data (U‐series, 87Sr/86Sr) for tufa indicate that siliciclastic rocks (a regional aquitard) interacted with discharging water. To access this aquitard, regional flow was probably partitioned into a permeable north–south damage zone of a north–south range‐bounding fault along the foot of the Resting Spring Range, which ultimately controlled the location of groundwater discharge. Existing models for modern discharge in the Tecopa Basin, by contrast, call upon westward interbasin flow in carbonate rocks from the Spring Mountains through the intervening (and nearly perpendicular) Nopah and Resting Spring Ranges. Understanding the controls on regional groundwater flow is critical in this and other arid regions where water is, by definition, a scarce resource. Thus, although it is a case study, this report highlights a fruitful approach to palaeohydrology that can be widely applied. Copyright © 2007 John Wiley & Sons, Ltd.
Field performance of organically propagated and grown strawberry plugs and fresh plants
Authors: Dolgun Oguz
Published: February 2007

This research was carried out during the growing seasons of 2003–2004 and 2004–2005 years in Aydın province in Turkey. Aydın is 50 km from the Aegean Sea, at an altitude of 74 m. Field performance of strawberry plants that were propagated and grown organically were investigated in order to determine the marketable yield. Chandler and Camarosa runner plants were planted separately in trays containing either perlite, peat, a 1:1 mix of perlite + peat, or sand for rooting. Fifty‐cell plug trays filled with peat were used for rooting plug plants. Rooted plants grown in either peat, perlite, the 1:1 mixture or sand were considered as fresh plants. Cold‐stored and bare‐root (frigo) nursery plants were used as controls. Results of the present study showed that peat‐grown and plug plants rooted and grew more vigorously than those grown in perlite, the perlite + peat mix or sand in the rooting unit. Plug plants had a high field performance in terms of marketable yield in organic conditions. Yields were higher and better than fresh plants and equal to bare‐root cold‐stored plants. In conclusion we suggest that strawberry runner plants can be easily propagated in plugs under organic conditions and used successfully for growing strawberries organically. Copyright © 2007 Society of Chemical Industry
A new solution for a partially penetrating constant‐rate pumping well with a finite‐thickness skin
Authors: Chiu Pin‐Yuan , Yeh Hund‐Der , Yang Shaw‐Yang
Published: February 2007

A mathematical model describing the constant pumping is developed for a partially penetrating well in a heterogeneous aquifer system. The Laplace‐domain solution for the model is derived by applying the Laplace transforms with respect to time and the finite Fourier cosine transforms with respect to vertical co‐ordinates. This solution is used to produce the curves of dimensionless drawdown versus dimensionless time to investigate the influences of the patch zone and well partial penetration on the drawdown distributions. The results show that the dimensionless drawdown depends on the hydraulic properties of the patch and formation zones. The effect of a partially penetrating well on the drawdown with a negative
patch zone is larger than that with a positive patch zone. For a single‐zone aquifer case, neglecting the effect of a well radius will give significant error in estimating dimensionless drawdown, especially when dimensionless distance is small. The dimensionless drawdown curves for cases with and without considering the well radius approach the Hantush equation (Advances in Hydroscience. Academic Press: New York, 1964) at large time and/or large distance away from a test well. Copyright © 2007 John Wiley & Sons, Ltd.
A block‐preconditioner for a special regularized least‐squares problem
Authors: Elfving Tommy , Skoglund Ingegerd
Published: February 2007

We consider a linear system of the form A1x1 + A2x2 + η=b1. The vector ηconsists of independent and identically distributed random variables all with mean zero. The unknowns are split into two groups x1 and x2. It is assumed that AA1 has full rank and is easy to invert. In this model, usually there are more unknowns than observations and the resulting linear system is most often consistent having an infinite number of solutions. Hence, some constraint on the parameter vector x is needed. One possibility is to avoid rapid variation in, e.g. the parameters x2. This can be accomplished by regularizing using a matrix A3, which is a discretization of some norm (e.g. a Sobolev space norm). We formulate the problem as a partially regularized least‐squares problem and use the conjugate gradient method for its solution. Using the special structure of the problem we suggest and analyse block‐preconditioners of Schur compliment type. We demonstrate their effectiveness in some numerical tests. The test examples are taken from an application in modelling of substance transport in rivers. Copyright © 2007 John Wiley & Sons, Ltd.
Aeration optimization of a wastewater treatment plant using genetic algorithm
Authors: Holenda B. , Domokos E. , Rédey Á. , Fazakas J.
Published: February 2007

This paper discusses the aeration optimization problem of an intermittently aerated wastewater treatment plant by the application of a stochastic optimization approach, genetic algorithm (GA). In this process, the alternating aerobic and anoxic conditions needed for nitrogen removal are realized in a single basin by switching the aeration sequentially on and off. Since the operation of these plants may be challenging both for economical and technical reasons, several previous studies have investigated the possibility of reduction of the operating cost, however, it turned out that for long‐term application these methods can save only limited per cent of the cost. Furthermore, these investigations also had to make problem simplifications in order to use optimization methods which usually need significant computational effort to give—only a local optimum—of the problem. The objective of this paper is to demonstrate an optimization procedure to minimize the pollution load in the receiving water body, rather than the operational cost, using a complete model of the treatment process. The results were evaluated based on rigorous evaluation criteria and showed that using GA‐based optimization strategy an optimal solution can be efficiently found where both pollution load and energy consumption savings can reach up to 10% compared to traditional control strategies. Copyright © 2007 John Wiley & Sons, Ltd.
Parametric uncertainty and disturbance attenuation in the suboptimal control of a non‐linear electrochemical process
Authors: Costanza Vicente
Published: February 2007

The optimal control of the hydrogen evolution reactions is attempted for the regulation and change of set‐point problems, taking into account that model parameters are uncertain and I/O signals are corrupted by noise. Bilinear approximations are constructed, and their dimension eventually increased to meet accuracy requirements with respect to the trajectories of the original plant. The current approximate model is used to evaluate the optimal feedback through integration of the Hamiltonian equations. The initial value for the costate is found by solving a state‐dependent algebraic Riccati equation, and the resulting control is then suboptimal for the electrochemical process. The bilinear model allows for an optimal Kalman–Bucy filter application to reduce external noise. The filtered output is reprocessed through a non‐linear observer in order to obtain a state‐estimation as independent as possible from the bilinear model. Uncertainties on parameters are attenuated through an adaptive control strategy that exploits sensitivity functions in a novel fashion. The whole approach to this control problem can be applied to a fairly general class of non‐linear continuous systems subject to analogous stochastic perturbations. All calculations can be handled on‐line by standard ordinary differential equations integration software. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of clay exfoliation and organic modification on morphological, dynamic mechanical, and thermal behavior of melt‐compounded polyamide‐6 nanocomposites
Authors: Mohanty Smita , Nayak Sanjay K.
Published: February 2007

Polyamide‐6/clay nanocomposites were prepared employing melt bending or compounding technique followed by injection molding using different organically modified clays. X‐ray diffraction and transmission electron microscopy were used to determine the molecular dispersion of the modified clays within the matrix polymer. Mechanical tests revealed an increase in tensile and flexural properties of the matrix polymer with the increase in clay loading from 0 to 5%. C30B/polyamide‐6 nanocomposites exhibited optimum mechanical performance at 5% clay loading. Storage modulus of polyamide‐6 also increased in the nanocomposites, indicating an increase in the stiffness of the matrix polymer with the addition of nanoclays. Furthermore, water absorption studies confirmed comparatively lesser tendency of water uptake in these nanocomposites. HDT of the virgin matrix increased substantially with the addition of organically modified clays. DSC measurements revealed both γ and α transitions in the matrix polymer as well as in the nanocomposites. The crystallization temperature (Tc) exhibited an increase in case of C30B/polyamide‐6 nanocomposites. Thermal stability of virgin polyamide‐6 and the nanocomposites has been investigated employing thermogravimetric analysis. POLYM. COMPOS., 28:153–162, 2007. © 2007 Society of Plastics Engineers
Managing appearance changes resulting from cancer treatment: resilience in adolescent females
Authors: Wallace Melissa L. , Harcourt Diana , Rumsey Nichola , Foot Annabel
Published: February 2007

Typically, adolescence is marked by cognitive and physical developments impacting on self‐esteem, independence and sexual awareness, often resulting in increased appearance awareness and dissatisfaction. Adolescents with cancer have the additional burden of illness, treatments and resultant appearance changes. This study aimed to explore the impact of these changes on adolescents who have had cancer. In depth, semi‐structured interviews were conducted with six females between 14 and 19 years who had completed treatment within the previous two years, and analysed using Interpretative Phenomenological Analysis (IPA). Concerns around an altered appearance were significant during treatment, serving as a constant reminder of ‘difference’ and a marker of illness. However, since treatment, participants expressed an apparent shift in views and expectations of their appearance, as well as the value placed on it—expressing increased satisfaction with their own appearance and a decrease in its importance. While important to acknowledge the distress and challenges experienced by participants, results highlight the need for research and care to focus on positive experiences of patients, rather than simply maladjustment. Explanations for the findings are explored, including the temporary nature of many appearance changes and the life‐threatening nature of cancer. Copyright © 2007 John Wiley & Sons, Ltd.
Quantitative high‐throughput determination of endogenous retinoids in human plasma using triple‐stage liquid chromatography/tandem mass spectrometry
Authors: Gundersen Thomas E. , Bastani Nasser E. , Blomhoff Rune
Published: February 2007

A high‐throughput ultrasensitive analytical method based on liquid chromatography with positive ion atmospheric pressure chemical ionization (APCI) coupled to tandem mass spectrometric detection (LC/MS/MS) was developed for the determination of all‐trans‐4‐oxo‐retinoic acid (at4oxoRA), 13‐cis‐4‐oxo‐retinoic acid (13c4oxoRA), 13‐cis‐retinoic acid (13cRA), all‐trans‐retinoic acid (atRA) and all‐trans‐retinol (atROH) in human plasma. A stable isotope of atRA was used as internal standard (IS). The analytes and IS were isolated from 100 µL plasma by acetonitrile mono‐phase extraction (MPE) performed in black 96‐well microtiterplates. A 100 µL injection was focused on‐column and chromatographed on an Agilent ZORBAX SB‐C18 rapid‐resolution high‐throughput (RRHT) column with 1.8‐µm particles (4.6 mm × 50 mm) maintained at 60°C. The initial mobile phase composition was acetonitrile/water/formic acid (10:90:0.1, v/v/v) delivered at 1.8 mL/min. Elution was accomplished by a fast gradient to acetonitrile/methanol/formic acid (90:10:0.1, v/v/v). The method had a chromatographic total run time of 7 min. An Applied Biosystems 4000 Q TRAP linear tandem mass spectrometer equipped with a heated nebulizer (APCI) ionization source was operated in multiple reaction monitoring (MRM) mode with the precursor‐to‐product ion transitions m/z 315.4 → 297 (4‐oxo‐retinoic acids), 301.2 → 205 (retinoic acids), 305.0 → 209 (IS) and 269.2 → 93 (retinol) used for quantification. The assay was fully validated and found to have acceptable accuracy, precision, linearity, sensitivity and selectivity. The mean extraction recoveries from spiked plasma samples were 80–105% for the various retinoids at three different levels. The intra‐day accuracy of the assay was within 8% of nominal and intra‐day precision was better than 8% coefficient of variance (CV) for retinoic acids. Inter‐day precision results for quality control samples run over a 12‐day period alongside clinical samples showed mean precision better than 12.5% CV. The limit of quantification was in the range of 0.1–0.2 ng/mL and the mass limit of detection (mLOD) was in the range 1–4 pg on column for the retinoic acids. The assay has been successfully applied to the analysis of 1700 plasma samples. Copyright © 2007 John Wiley & Sons, Ltd.
Liquid chromatography/tandem mass spectrometry determination of (4S,2RS)‐2,5,5‐trimethylthiazolidine‐4‐carboxylic acid, a stable adduct formed between D‐(–)‐penicillamine and acetaldehyde (main biological metabolite of ethanol), in plasma, liver and brain rat tissues
Authors: Serrano Elena , Pozo Oscar J. , Beltrán Joaquin , Hernández Felix , Font Laura , Miquel Marta , Aragon Carlos M. G.
Published: February 2007

Acetaldehyde, the main biological metabolite of ethanol, is nowadays considered to mediate some ethanol‐induced effects. Previous studies on alcohol effect attenuation have shown that D‐(–)‐penicillamine (3‐mercapto‐D‐valine), a thiol amino acid, acts as an effective agent for the inactivation of acetaldehyde. In the study reported here, laboratory rats were treated with ethanol and D‐(–)‐penicillamine at different doses looking for the interaction (in vivo) of D‐(–)‐penicillamine with metabolically formed acetaldehyde following a condensation reaction to form the stable adduct (4S,2RS)‐2,5,5‐trimethylthiazolidine‐4‐carboxylic acid (TMTCA). A novel and rapid procedure based on liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS) was developed for quantification and reliable identification of TMTCA in different rat tissues, including plasma, liver and brain. Firstly, plasma was obtained from whole blood. Then, proteins were precipitated from plasma, brain and liver extracts with acetonitrile and the clarified extracts diluted 10‐fold. A 20 µL aliquot of the final extracts was then analyzed using an Atlantis C18 5 µm, 100 × 2 mm column which was connected to the electrospray source of a LC/triple quadrupole mass spectrometer. The analyte was detected in positive ion mode acquiring four MS/MS transitions in selected reaction monitoring (SRM) mode.

The method has been validated and it has proved to be fast, reliable and sensitive. The accuracy and precision were evaluated by means of recovery experiments from plasma, liver and brain samples fortified at two concentration levels obtaining satisfactory recoveries in all cases: 95 and 105% in plasma (at 10 and 100 ng/mL, respectively), 79 and 89% in brain (100 and 1000 ng/g), 85 and 99% in liver (100 and 1000 ng/g). Precision, expressed as repeatability, was in all tissues analyzed lower than 17% at the two concentrations tested. The estimated detection limits were 1 ng/mL in plasma, 4 ng/g in brain and 5 ng/g in liver. The limit of quantitation objective (the lowest concentration that was validated with acceptable results) was set up at 10 ng/mL for plasma and 100 ng/g for brain and liver tissue.

The reliable identification of the analyte was ensured by the acquisition of four transitions and by their ion abundance ratio measurement. Due to its excellent selectivity and sensitivity, the method developed in this work provides an excellent tool for the specific determination of this cyclic amino acid in biological samples. Copyright © 2007 John Wiley & Sons, Ltd.
Understanding the influence of post‐excite radius and axial confinement on quantitative proteomic measurements using Fourier transform ion cyclotron resonance mass spectrometry
Authors: Frahm Jennifer L. , Velez Coral M. Capo , Muddiman David C.
Published: February 2007

Early studies of Fourier transform ion cyclotron resonance (FT‐ICR) mass spectrometry (MS) explored many of the fundamental issues surrounding the potential of the technique to provide quantitative data. Improvements in instrument technology and the analysis of larger molecules in increasingly complex mixtures warrant not only a revisit to some of these earlier studies, but a more comprehensive examination of the influence of various instrument parameters on quantitative (absolute and relative) measurements in proteomics. We present a detailed examination of the role that acquisition time, excite voltage (i.e. excite radius), trapping voltage, and the type of excitation waveform have on the ability of FT‐ICR to accurately quantify biological molecules. The use of a stable‐isotope‐labeled and unlabeled phenyl isocyanate derivatized peptide allows us to ascribe the effects of FT‐ICR‐MS on quantification, thus eliminating the contribution of ionization differences to ion abundance. To adequately assess the multiple parameters in the large dataset, we develop a multiplicative quality factor that encompasses the total ion abundance, as well as the accuracy and the precision of abundance ratios. This assessment allows facile determination of optimal instrument parameters for quantitative measurements. Copyright © 2007 John Wiley & Sons, Ltd.
The isoperimetric constant of the random graph process
Authors: Benjamini Itai , Haber Simi , Krivelevich Michael , Lubetzky Eyal
Published: February 2007

The isoperimetric constant of a graph G on n vertices, i(G), is the minimum of $|\partial S| \over |S|$, taken over all nonempty subsets S ⊂ V (G) of size at most n/2, where ∂S denotes the set of edges with precisely one end in S. A random graph process on n vertices, $\tilde{G}(t)$, is a sequence of $n \choose 2$ graphs, where $\tilde{G}(0)$ is the edgeless graph on n vertices, and $\tilde{G}(t)$ is the result of adding an edge to $\tilde{G}(t-1)$, uniformly distributed over all the missing edges. The authors show that in almost every graph process $i(\tilde{G}(t))$ equals the minimal degree of $\tilde{G}(t)$ as long as the minimal degree is o(log n). Furthermore, it is shown that this result is essentially best possible, by demonstrating that along the period in which the minimum degree is typically Θ(log n), the ratio between the isoperimetric constant and the minimum degree falls from 1 to $1\over 2$, its final value. © 2007 Wiley Periodicals, Inc. Random Struct. Alg., 2008
Regenerative pseudo‐noise (PN) ranging sequences for deep‐space missions
Authors: Massey James L. , Boscagli Giovanni , Vassallo Enrico
Published: February 2007

Space Agencies are currently considering replacing conventional ranging systems with regenerative schemes for future demanding interplanetary missions. The Consultative Committee for Space Data Systems (CCSDS) in charge of standardization among Space Agencies is studying both Pseudo‐Noise (PN) and Pseudo‐Noise‐Like (PNL) sequences and is due to generate a recommended standard (Blue Book) by 2007. The present paper treats the PN schemes under consideration by CCSDS, which include the weighted‐voting Tausworthe PN ranging scheme and the balanced weighted‐voting Tausworthe PN ranging scheme. Copyright © 2007 John Wiley & Sons, Ltd.
Performance, conformance and change: towards a sustainable tourism strategy for Scotland
Authors: Macleod Calum , Todnem By Rune
Published: February 2007

This article examines the development of a sustainable tourism strategy for Scotland. It outlines conceptual features associated with sustainable tourism and considers the evolving public policy context for sustainable tourism in Scotland. Relevant aspects of recently published strategy documents are reviewed. Public policy implementation and change management theory is used to identify variables and situational contexts likely to influence the evolution of a Scottish sustainable tourism strategy and perceptions of strategy success. The article concludes that future strategy development will be best served by securing implementation performance instead of implementation conformance and explains why this should be the case. Finally, recommendations are made for future strategy development. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
On modelling metabolism‐based biomarkers of exposure: a comparative analysis of nonlinear models with few repeated measurements
Authors: Johnson Brent A. , Rappaport Stephen M.
Published: February 2007

Establishing and characterizing exposure–biomarker relationships is an important problem in molecular epidemiology. The problem is difficult due to several complicating features, namely, the biomarker response is a nonlinear function of exposure and unknown parameters; variation in exposure and biomarker levels occurs both within and between subjects; and errors tend to be heteroscedastic. To overcome some of the statistical challenges in analysing such data, it is common for the investigator to make several assumptions about the data structure. For example, it is common to assume that the natural logarithm of right‐skewed, biomarker measurements lead to homoscedasicity and normality so the effect of outliers is minimized and Gauss–Markov theory is applicable. In this paper, we compare a lognormal maximum likelihood estimator (MLE) to generalized estimating equations (GEE) for drawing statistical inference in a nonlinear model of a benzene biomarker (benzene oxide–albumin adducts) as a function of benzene exposure. We explore the characteristic properties of the lognormal MLE under a certain type of model misspecification and compare its small sample performance to the estimating equation approach in simulation studies. We show that the multiplicative lognormal model can lead to severe biases for modest deviations from the true outcome (biomarker) distribution. Furthermore, the lognormal MLE can exhibit very poor small sample properties even under the true model. All methods are applied in a novel data analysis from a study of benzene‐exposed workers in China. Copyright © 2007 John Wiley & Sons, Ltd.
Bayesian methods for searching for optimal rules for timing intercourse to achieve pregnancy
Authors: Scarpa Bruno , Dunson David B.
Published: February 2007

With societal trends towards increasing age at starting a pregnancy attempt, many women are concerned about achieving conception before the onset of infertility, which precedes menopause. Couples failing to conceive a pregnancy within 12 months are classified as clinically infertile, and may be recommended for assisted reproductive therapy (ART). Because many ART procedures are expensive and may convey an increased risk of adverse outcomes for the offspring, it is advantageous to decrease time to pregnancy by natural methods. One possibility is to intentionally time intercourse during the days of the menstrual cycle having the highest conception probabilities. This article proposes a Bayesian decision theoretic approach for searching for optimal rules for timing intercourse based on cycle day, secretions and other information. Good rules result in high conception probabilities while requiring minimal targeted intercourse. A biologically based statistical model is used to relate cycle day and biomarkers to the conception probability. A stochastic search procedure is then developed to search for rules with high expected utility, and the methods are applied to data from a recent Italian study. Copyright © 2007 John Wiley & Sons, Ltd.
PAPER PRESENTED AT INTERNATIONAL WORKSHOP ON INCREASING WHEAT YIELD POTENTIAL, CIMMYT, OBREGON, MEXICO, 20–24 MARCH 2006 Conservation agriculture in South Asia
Authors: GUPTA R. , SAYRE K.
Published: February 2007

The Green Revolution era focused on enhancing the production and productivity of rice and wheat. New challenges demand that the issues of efficient resource use and resource conservation receive high priority to ensure that past gains can be sustained and further enhanced to meet the emerging needs. Extending some of the resource-conserving interventions developed for wheat to rice culture is a major challenge for researchers and farmers alike. The present paper shares recent research experiences on resource conservation technologies involving tillage and crop establishment options and associated agronomic practices which enable farmers in reducing production costs, increase profitability and help them move forward in the direction of adopting conservation agriculture.
Parasites as heavy metal bioindicators in the shark Carcharhinus dussumieri from the Persian Gulf
Authors: MALEK M. , HASELI M. , MOBEDI I. , GANJALI M. R. , MacKENZIE K.
Published: February 2007

In this study the lead and cadmium concentrations in the liver, intestine, muscle and gonad of the shark Carcharhinus dussumieri and its parasites, Anthobothrium sp. and Paraorigmatobothrium sp. (Cestoda), were measured and compared. Tissue samples were collected from Iranian coastal waters of the Persian Gulf. After tissue preparation, the cadmium and lead concentrations were analysed using the Inductively Coupled Plasma technique. The results revealed that lead and cadmium concentrations in both parasite species were many times higher than in the host tissues. The results strongly support the view that helminth parasites are extremely sensitive early warning bioindicators, particularly in sensitive environments under threat but where pollution levels are presently low. They may also have a beneficial effect on the health of their hosts by acting as heavy metal filters.
Laser-driven ion accelerators: Spectral control, monoenergetic ions and new acceleration mechanisms
Authors: FLIPPO K. , HEGELICH B.M. , ALBRIGHT B.J. , YIN L. , GAUTIER D.C. , LETZRING S. , SCHOLLMEIER M. , SCHREIBER J. , SCHULZE R. , FERNÁNDEZ J.C.
Published: February 2007

Los Alamos National Laboratory short pulse experiments have shown using various target cleaning techniques such that heavy ion beams of different charge states can be produced. Furthermore, by controlling the thickness of light ions on the rear of the target, monoenergetic ion pulses can be generated. The spectral shape of the accelerated particles can be controlled to yield a range of distributions, from Maxwellian to ones possessing a monoenergetic peak at high energy. The key lies in understanding and utilizing target surface chemistry. Careful monitoring and control of the surface properties and induction of reactions at different temperatures allows well defined source layers to be formed, which in turn lead to the desired energy spectra in the acceleration process. Theoretical considerations provide understanding of the process of monoenergetic ion production. In addition, numerical modeling has identified a new acceleration mechanism, the laser break-out afterburner that could potentially boost particle energies by up to two orders of magnitude for the same laser parameters. This mechanism may enable application of laser-accelerated ion beams to venues such as compact accelerators, tumor therapy, and ion fast ignition.
Glass fibers for stimulated Brillouin scattering and phase
conjugation
Authors: MEISTER STEFAN , RIESBECK THOMAS , EICHLER HANS J.
Published: February 2007

Stimulated Brillouin scattering (SBS) and the laser-induced damage
threshold (LIDT) in different multimode glass fibers with a core diameter
of 200 μm are determined. Antireflective coatings for fiber end-faces
with high LIDT are developed, which enhance the SBS reflectivity and
reduce unwanted front-face reflections. The morphology of pump- and
Stokes-radiation induced damages is investigated using atomic force
microscopy.
Electron acceleration to high energy by using two chirped lasers
Authors: GUPTA D. N. , SUK H.
Published: February 2007

A scheme for electron acceleration by two crossing chirped lasers has been proposed. An important effect of a frequency chirp of the laser is investigated. Two high intensity chirped lasers, with the same amplitude and frequency, crossing at an arbitrary angle in a vacuum, interfere, causing modulation of laser intensity. An electron experiences a ponderomotive force due to the resultant field of lasers and gains considerable energy. For a certain crossing angle, the electron gains maximum energy due to the constructive interference. A frequency chirp of the laser plays an important role during the electron acceleration in a vacuum. The electron momentum increases due to the frequency chirp. Hence, the electron energy is enhanced during acceleration.