bluuebunny/crossref_metadata_2025 huggingface dataset:
Modifications to the IMFAST leaf sequencing optimization algorithm
Authors: Siochi R. Alfredo C.
Published: December 2004

The optimizing leaf sequencer IMFAST minimizes intensity modulated treatment times. However, algorithm modifications can yield improved results. Currently, during segment extraction, the largest extract for a given number of levels is chosen. The modification chooses an extract that yields the fewest segments and levels when the rod‐pushing algorithm is applied to the difference between the original map and the extract. Also, successive optimization parameter values are now allowed to increase. These modifications reduced the number of segments and the relative fluence from the original algorithm by an average of 7%–11% and 8%–17%, respectively, depending on whether interdigitation and/or tongue‐and‐groove constraints were considered. The tests were done on two clinical head and neck intensity modulated radiation therapy cases. Compared to the sweeping window algorithm, a reduction of 35%–55% of the number of segments is possible with a change in the relative fluence of , depending on the constraints. Compared to other previously published algorithms that deal with the constraints tested here, the modified IMFAST algorithm provides the greatest reduction in the number of segments with the minimum increase in the relative fluence.
Influence of field size on a PTW type 23342 plane‐parallel ionization chamber's response
Authors: Austerlitz C. , Villar H. P. , Santos M. A. P.
Published: December 2004

The response of a PTW type 23342 plane‐parallel ionization chamber, both in air and in phantom, was evaluated for x‐ray tube potentials between 30 and and radiation field diameters ranging from 30 to . The experiments were performed with a calibrated Pantak x‐ray machine and made use of the same set of x‐ray qualities adopted by the PTB primary laboratory for the calibration of such chambers. A Plexiglas® phantom long, wide, and deep was used for phantom measurements. X‐ray qualities were characterized by using 99.99% pure aluminum filters. On the basis of the IAEA's TRS 398, the article discusses the dependence of the plane‐parallel ionization chamber readings with field size in air and in phantom, its implication with regard to clinical dosimetry, cross‐calibration, and dissemination of calibration factors.
Near‐field dosimetry of sources for interstitial brachytherapy implants measured using thermoluminescent sheets
Authors: Iwata Kazuro , Yue Ning J. , Nath Ravinder
Published: December 2004

The dosimetric characteristics were measured for two types of low‐energy photon‐emitting sources by using a wide and highly sensitive thermoluminescent (TL) sheet film, which was developed for two‐dimensional dose distribution measurements. The TL film is made of Teflon homogeneously mixed with small powders of thermoluminescence (: Eu doped). Various dosimetric parameters (i.e., radial dose function, 2D and 1D anisotropy functions) of model 6711 and 6702 sources were obtained at various distances from the source surfaces to . These parameters obtained with TL sheet were compared with the data recommended in the updated AAPM TG‐43 report. The radial dose functions measured with TL sheet are in agreement with those established data of model 6711 seed and model 6702 seed at most of the distances within 5% and 7%, respectively. All the measured anisotropy functions showed symmetry about the longitudinal source axis. The anisotropy of dose distributions was clearly present in the immediate vicinity of the source edges. The measured 2D anisotropy function values at are in reasonably good agreement with the recommended values. The differences at two points in the 1D anisotropy functions measured with TL sheet and the established data at from source center were 0.7% and 1.9% for model 6711 and 6702 sources, respectively; the differences at were 1.5% and 1.7% for model 6711 and 6702 sources, respectively. The relative dosimetric characteristics in the vicinity of actual interstitial brachytherapy sources containing have been experimentally determined by using the TL sheet as a 2D dosimeter.
Optimal field splitting for large intensity‐modulated fields
Authors: Kamath Srijit , Sahni Sartaj , Ranka Sanjay , Li Jonathan , Palta Jatinder
Published: December 2004

The multileaf travel range limitations on some linear accelerators require the splitting of a large intensity‐modulated field into two or more adjacent abutting intensity‐modulated subfields. The abutting subfields are then delivered as separate treatment fields. This workaround not only increases the treatment delivery time but it also increases the total monitor units (MU) delivered to the patient for a given prescribed dose. It is imperative that the cumulative intensity map of the subfields is exactly the same as the intensity map of the large field generated by the dose optimization algorithm, while satisfying hardware constraints of the delivery system. In this work, we describe field splitting algorithms that split a large intensity‐modulated field into two or more intensity‐modulated subfields with and without feathering, with optimal MU efficiency while satisfying the hardware constraints. Compared to a field splitting technique (without feathering) used in a commercial planning system, our field splitting algorithm (without feathering) shows a decrease in total MU of up to 26% on clinical cases and up to 63% on synthetic cases.
A simple method of independent treatment time verification in gamma knife radiosurgery using integral dose
Authors: Jin Jian‐Yue , Drzymala Robert , Li Zuofeng
Published: December 2004

The purpose of this study is to develop a simple independent dose calculation method to verify treatment plans for Leksell Gamma Knife radiosurgery. Our approach uses the total integral dose within the skull as an end point for comparison. The total integral dose is computed using a spreadsheet and is compared to that obtained from Leksell GammaPlan®. It is calculated as the sum of the integral doses of 201 beams, each passing through a cylindrical volume. The average length of the cylinders is estimated from the Skull‐Scaler measurement data taken before treatment. Correction factors are applied to the length of the cylinder depending on the location of a shot in the skull. The radius of the cylinder corresponds to the collimator aperture of the helmet, with a correction factor for the beam penumbra and scattering. We have tested our simple spreadsheet program using treatment plans of 40 patients treated with Gamma Knife® in our center. These patients differ in geometry, size, lesion locations, collimator helmet, and treatment complexities. Results show that differences between our calculations and treatment planning results are typically within , with a maximum difference of . We demonstrate that our spreadsheet program is a convenient and effective independent method to verify treatment planning irradiation times prior to implementation of Gamma Knife radiosurgery.
Stereotactic arc therapy for small elongated tumors using cones and collimator jaws; dosimetric and planning aspects
Authors: de Pooter J. A. , Essers M. , Nowak P. J. C. M. , de Pan C. , Heijmen B. J. M. , Levendag P. C.
Published: December 2004

Stereotactic arc treatment of small intracranial tumors is usually performed with arcs collimated by circular cones, resulting in treatment volumes which are basically spherical. For nonspherical lesions this results in a suboptimal dose distribution. Multiple isocenters may improve the dose conformity for these lesions, at the cost of large overdosages in the target volume. To achieve improved dose conformity as well as dose homogeneity, the linac jaws (with a minimum distance of 1.0 cm to the central beam axis) can routinely be used to block part of the circular beams. The purpose of this study was to investigate the feasibility of blocking cones with diameters as small as 1.0 cm and a minimum distance between the jaw and the central beam axis of 0.3 cm. First, the reproducibility in jaw positioning and resulting dose delivery on the treatment unit were assessed. Second, the accuracy of the TPS dose calculation for these small fields was established. Finally, clinically applied treatment plans using nonblocked cones were compared with plans using the partially blocked cones for several treatment sites. The reproducibility in dose delivery on our Varian Clinac 2300 C/D machines on the central beam axis is 0.8% (1 SD). The accuracy of the treatment planning system dose calculation algorithm is critically dependent on the used fits for the penumbra and the phantom scatter. The average deviation of calculated from measured dose on the central beam axis is (1 SD), which is clinically acceptable. Partial cone blocking results in improved dose distributions for elongated tumors, such as vestibular schwannoma and uveal melanoma. Multiple isocenters may be avoided. The technique is easy to implement and requires no additional workload.
Yuk-Hap-Tang Induces Apoptosis by Intervening Mn-SOD in Human Cervical Carcinoma HeLa Cells
Authors: Chae H. J. , Park J. M. , Lee G. Y. , Park H. R. , Chae S. W. , Jeong G. S. , Kim H. M. , Kim S. B. , Yoo S. K. , Kim H. R.
Published: December 2004

Yuk-Hap-Tang (YHT) induces cell death in human cervical carcinoma HeLa cells. Caspase-3, -6 and -9 were markedly activated in HeLa cells treated with YHT. The preferred substrate for caspase-3 cysteine protease, PARP, was cleaved to its 85-kDa cleavage product. YHT increased the amount of the anti-apoptotic protein, Bcl-2, and the pro-apoptotic protein, Bax. Although p53 has been reported to accumulate in cancer cells in response to anticancer agents, the p53 expression level was not changed in HeLa cells treated with YHT. Manganese (Mn)-TBAP, a mitochondria-specific SOD mimetic agent and NAC/GSH (N-acetyl cysteine/reduced glutathione) reduced the YHT-induced cytotoxicity and decreased the number of the YHT-induced apoptotic cells. Furthermore, YHT reduced the expression of Mn-SOD protein and its activity in HeLa cells. The data demonstrate that YHT induces the apoptosis of human cervical carcinoma HeLa cells by intervening Mn-SOD.
Mineralogical and Chemical Changes in Pyrite after Traditional Processing for Use in Medicines
Authors: Hwang Jeong , Hur Soon Do , Seo Young Bae
Published: December 2004

Pyrite has been the most commonly used medicinal mineral, and its toxicity was reduced by traditional processing operations including heating and quenching in vinegar. To verify the scientific effects of this process, pyrite was processed at temperatures up to 850°C and through as many as five processing cycles. A metal extraction test was carried out from the processed pyrites on the assumption that pyrite medicines with the lowest toxic metal content would be most desirable. Increasing temperature and the number of processing cycles promoted phase change of pyrite to hematite, reduction of toxic metals in pyrite and their concentrations in the extraction solutions. However, the relationships between variations in extracted elements and the number of processing cycles at the same processing temperature were not clearly defined. Heating temperature is more important than the number of processing cycles for effective processing, and pyrite should be processed at the highest possible temperature in order to diminish highly toxic metals such as As and Pb.
BLACK HOLES IN THEORIES WITH LARGE EXTRA DIMENSIONS: A REVIEW
Authors: KANTI PANAGIOTA
Published: December 2004

We start by reviewing the existing literature on the creation of black holes during high-energy particle collisions, both in the absence and in the presence of extra, compact, spacelike dimensions. Then, we discuss in detail the properties of the produced higher-dimensional black holes, namely the horizon radius, temperature and life-time, as well as the physics that governs the evaporation of these objects, through the emission of Hawking radiation. We first study the emission of visible Hawking radiation on the brane: we derive a master equation for the propagation of fields with arbitrary spin in the induced-on-the-brane black hole background, and we review all existing results in the literature for the emission of scalars, fermions and gauge bosons during the spin-down and Schwarzschild phases of the life of the black hole. Both analytical and numerical results for the graybody factors and radiation spectra are reviewed and exact results for the number and type of fields emitted on the brane as a function of the dimensionality of space–time are discussed. We finally study the emission of Hawking radiation in the bulk: graybody factors and radiation spectra are presented for the emission of scalar modes, and the ratio of the missing energy over the visible one is calculated for different values of the number of extra dimensions.
A TOY MODEL OF THE FIVE-DIMENSIONAL UNIVERSE WITH THE COSMOLOGICAL CONSTANT
Authors: TARKOWSKI WOJCIECH
Published: December 2004

A value of the cosmological constant in a toy model of the five-dimensional universe is calculated in such a manner that it remains in agreement with both astronomical observations and the quantum field theory concerning the zero-point fluctuations of the vacuum. The (negative) cosmological constant is equal to the inverse of the Planck length squared, which means that in the toy model the vanishing of the observed value of the cosmological constant is a consequence of the existence of an energy cutoff exactly at the Planck level. In turn, a model for both a virtual and a real particle–antiparticle pair is proposed which describes properly some energetic properties of both the vacuum fluctuations and created particles, as well as it allows one to calculate the discrete "bare" values of an elementary particle's mass, electric charge and intrinsic angular momentum (spin) at the energy cutoff. The relationships between the discussed model and some phenomena such as the Zitterbewegung and the Unruh–Davies effect are briefly analyzed, too. The proposed model also allows one to derive the Lorentz transformation and the Maxwell equations while considering the properties of the vacuum filled with the sea of virtual particles and their antiparticles. Finally, the existence of a finite value of the vacuum-energy density resulting from the toy model leads us to the formulation of dimensionless Einstein equations which may be derived from the Lagrangian with a dimensionless (naively renormalized) coupling constant.
FUNCTIONAL BOSONIZATION WITH TIME DEPENDENT PERTURBATIONS
Authors: NAÓN CARLOS M. , SALVAY MARIANO J. , TROBO MARTA L.
Published: December 2004

We extend a path-integral approach to bosonization previously developed in the framework of equilibrium Quantum Field Theories, to the case in which time-dependent interactions are taken into account. In particular we consider a noncovariant version of the Thirring model in the presence of a dynamic barrier at zero temperature. By using the Closed Time Path (Schwinger–Keldysh) formalism, we compute the Green's function and the Total Energy Density of the system. Since our model contains the Tomonaga–Luttinger model as a particular case, we make contact with recent results on nonequilibrium electronic systems.
Differing physiological effects of epinephrine in type 1 diabetes and nondiabetic humans
Authors: Guy Deanna Aftab , Sandoval Darleen , Richardson M. A. , Tate Donna , Flakoll Paul J. , Davis Stephen N.
Published: December 2004

Acute increases of the key counterregulatory hormone epinephrine can be modified by a number of physiological and pathological conditions in type 1 diabetic patients (T1DM). However, it is undecided whether the physiological effects of epinephrine are also reduced in T1DM. Therefore, the aim of this study was to determine whether target organ (liver, muscle, adipose tissue, pancreas, cardiovascular) responses to epinephrine differ between healthy subjects and T1DM patients. Thirty-four age- and weight-matched T1DM ( n = 17) and healthy subjects ( n = 17) underwent two randomized, single-blind, 2-h hyperinsulinemic euglycemic clamp studies with (Epi) and without epinephrine infusion. Muscle biopsy was performed at the end of each study. Epinephrine levels during Epi were similar in all groups (4,039 ± 384 pmol/l). Glucose (5.3 ± 0.06 mmol/l) and insulin levels (462 ± 18 pmol/l) were also similar in all groups during the glucose clamps. Glucagon responses to Epi were absent in T1DM and significantly reduced compared with healthy subjects. Endogenous glucose production during the final 30 min was significantly greater during Epi in healthy subjects compared with T1DM (8.4 ± 1.3 vs. 4.4 ± 0.6 μmol·kg−1·min−1, P = 0.041). Glucose uptake showed almost a twofold greater decrease with Epi in healthy subjects vs. T1DM (Δ31 ± 2 vs. Δ17 ± 2 nmol·kg−1·min−1, respectively, P = 0.026). Glycerol, β-hydroxybutyrate, and nonesterified fatty acid (NEFA) all increased significantly more in T1DM compared with healthy subjects. Increases in systolic blood pressure were greater in healthy subjects, but reductions of diastolic blood pressure were greater in T1DM patients with Epi. Reduction of glycogen synthase was significantly greater during epinephrine infusion in T1DM vs. healthy subjects. In summary, despite equivalent epinephrine, insulin, and glucose levels, changes in glucose flux, glucagon, and cardiovascular responses were greater in healthy subjects compared with T1DM. However, T1DM patients had greater lipolytic responses (glycerol and NEFA) during Epi. Thus we conclude that there is a spectrum of significant in vivo physiological differences of epinephrine action at the liver, muscle, adipose tissue, pancreas, and cardiovascular system between T1DM and healthy subjects.
Anti–Transforming Growth Factor Antibody at Low but Not High Doses Limits Cyclosporine-Mediated Nephrotoxicity Without Altering Rat Cardiac Allograft Survival
Authors: Khanna Ashwani K. , Plummer Matthew S. , Hilton Gail , Pieper Galen M. , Ledbetter Steven
Published: December 2004

Background—Long-term treatment of cardiac transplant recipients with cyclosporine results in a progressive decline in kidney function in a large number of patients. This complication is one of the most important prognostic parameters that determine the outcome of cardiac transplantation. Transforming growth factor-β (TGF-β) is one of the most potent mediators of the fibrogenic effects of cyclosporine.

Methods and Results—With the use of an experimental rodent model, heterotopic heart transplantation was performed, creating histocompatibility-disparate allografts. Because TGF-β in part mediates both the immunosuppressive and nephrotoxic effects of cyclosporine, recipients were treated with cyclosporine with and without anti–TGF-β antibody to determine whether anti–TGF-β antibody could reduce the nephrotoxic effects of cyclosporine. Intrarenal expression of TGF-β, collagen, fibronectin, matrix metalloproteinase-2, and tissue inhibitor of metalloproteinase-2 was studied with the use of reverse transcription–polymerase chain reaction. Intrarenal expression of TGF-β protein was studied by immunohistochemistry and with the use of ELISA to quantify circulating levels of TGF-β protein in plasma. Cyclosporine-induced graft survival (immunosuppressive effect) was abrogated with a higher concentration (2.5 mg/kg) of anti–TGF-β antibody, whereas a lower concentration (1 mg/kg) inhibited both cyclosporine-induced expression of fibrogenic molecules and renal toxicity.

Conclusions—These results provide credence to the pivotal role of TGF-β in immunosuppression-associated renal toxicity in recipients of cardiac transplantation. Furthermore, these findings support a potentially significant therapeutic use of optimal concentration of anti–TGF-β antibody to ameliorate cyclosporine-associated nephrotoxicity in cardiac transplant recipients.
Custom, Islamic Law, and Statutory Legislation: Marriage Registration and Minimum Age at Marriage in the Egyptian Sharīʿa Courts
Authors: Shaham Ron
Published: December 2004

In this essay I examine the interaction between social change and law, in general, and between social custom, Islamic Law and statutory legislation, in particular, by analyzing forty decisions issued by Egyptian sharīʿa courts from the turn of the present century until 1955. These decisions, which deal with the application of two reforms pertaining to marriage, indicate, first, that whenever legal reform confronted entrenched social practices, litigants found legal strategies for circumventing the reform; and second, that the attitudes of judges (qādīs) toward the reforms were diverse and complex. Overall, the qādīs applied the reforms, whether because they believed them to be necessary or feared a confrontation with the government. I conclude that in order for a legal reform to be successful in molding social behavior, it must be complemented by state policies that promote the education of women and encourage them to participate in the labor market.
Bequests as an Instrument for Accommodating Inheritance Rules: Israel as a Case Study
Authors: Layish Aharon
Published: December 2004

Freedom of civil testation available, since 1965, to Israeli Muslims within some of the sharīʿa courts, has replaced the family waqf as an instrument for circumventing the compulsory rules of inheritance (ʿilm al-farāʾid). This marks in many respects the victory of custom over the sharīʿa. On the basis of an analysis of bequests probated in the sharīʿa courts, I conclude that the bequest is being used as a means to prevent fragmentation of the patrimony and to preserve it in the hands of the testator's sons or, in their absence, other male agnates, in units as complete and economically sound as possible. While excluding his wife and daughters from the estate, the testator secures their economic well-being by allocating them subsistence allowances and residential rights, that is, customary maintenance out of the estate. At the same time, the making of bequests demonstrates the capacity of women to dispose of property. The concern for orphaned grandchildren is another incentive for making a will.
Spanish Scholarship on Islamic Law
Authors: Fierro Maribel
Published: December 2004

This essay begins by situating Spanish scholarship on Islamic law in the wider context of Arabic and Islamic studies in Spain, stressing two salient characteristics of the latter: its concentration on Andalusī subjects and its relative isolation from the rest of Western scholarship. I then review the production of Spanish scholarship in the field of Islamic law, focusing on three historical periods: the first steps in the nineteenth century (Gayangos, Ribera and his pupils); the period of the Spanish Civil War (1936-1939) when the work of López Ortiz, Morata, and Vila was cut short just as Spanish scholarship on Islamic law was coming of age; and the post-war period, when several attempts were made to renew the study of Islamic law. In the conclusion, I assess the current situation and consider future prospects. A basic bibliography of Spanish scholarship on Islamic law follows the article.
ʿAmal V. ḥadīth in Islamic Law: The Case of Sadl Al-Yadayn (Holding One's Hands by One's Sides) when Doing the Prayer
Authors: Dutton Yasin
Published: December 2004

Most Muslims today understand the term sunna to refer to the sunna, or normative practice, of the Prophet as contained in the standard collections of Prophetic ḥadīth. Because of the relatively late appearance of these collections, and the frequent anomalies between their contents and those of early fiqh sources, many Western scholars have concluded that the concept of the “sunna of the Prophet” is a secondary development that is not reflected in the earliest stages of Islamic law. The issue of Sadl Al-Yadayn, where a substantial body of Sunnī—and all non-Sunnī—opinion holds to a judgment based on ʿamal (“practice”) in overt rejection of numerous Prophetic ḥadīths, suggests that we have to reinstate the traditional picture of an early concept of the sunna of the Prophet, but as defined by ʿamal rather than ḥadīth.
‘Renaissance de la Bharatie’
Authors: Wink André
Published: December 2004

GUY DELEURY, Les Indes Florissantes: Anthologie des Voyageurs Français (1750-1820). Préface par S.E. Idris Hassan Latif, Paris: Ed. R. Laffont, 1991. xvi + 1064 pp. 130 Ff.FLORENCE D'SOUZA, Les Voyageurs Français en Inde (1757-1818) (Thèse Nouveau Doctorat), Université de Paris, III (1991), 2 vols. 1156 pp.
Waqf et Monnaie dans l'Égypte Mamlūke
Authors: Hennequin Gilles
Published: December 2004

The accounts of Ğawhar al-Lālā inform us, at least indirectly, about the functioning of money institutions in Mamluk Egypt. Each minting serves to support a currency; the diverse currencies evolved independently from one to the other on the basis of ‘monetary polities’, subjugated to a succession of fiscal devices. The frequency of the authorizations gave to the initiators the chance [to gain from] interest-bearing speculations.
Innkeeping in Jewish Society in Roman Palestine
Authors: Rosenfeld Ben-Zion
Published: December 2004

This study discusses the historical evolution of inns and innkeeping in Jewish society in Roman Palestine and examines their social implications, and in particular, the relationship between opposite ends of the social ladder, and what this meant for the status of women. After a sketch of innkeeping in the Ancient Near East from the third millennium B.C.E., the focus is on the Roman period. During that period, it is argued, innkeeping, originally associated with sexual promiscuity and the lowest strata of society, gained acceptance only with difficulty in the religiously conservative Jewish society of the time. Nevertheless, in time it became quite common and rabbinic sources of the 2nd and 3rd centuries C.E. take it for granted.
The Judaisms of Kaifeng and Cochin: Parallel and Divergent Styles of Religious Acculturation
Authors: Katz Nathan
Published: December 2004

This comparative study of the religious life of the Jewish communities of Kaifeng, China, and Cochin, India, contributes to our understanding the mechanisms by which a religion becomes acculturated into its environment. Borrowing the metaphor of foregrounding/backgrounding from Gestalt psychology, both the plasticity and tenacity of Judaism are emphasized.
Les Citations Probantes (Šawāhid) en Langue
Authors: Gilliot Claude
Published: December 2004

Sommaire: I. Présentation (Â§ 1). II. Traduction annotée (Â§ 2-16). III. Éléments de bibliographie sur le genre (Â§ 17-47). IV. Références bibliographiques et abréviations. Index nominum.
Evidence for a k−5/3 Spectrum from the EOLE Lagrangian Balloons in the Low Stratosphere
Authors: Lacorata Guglielmo , Aurell Erik , Legras Bernard , Vulpiani Angelo
Published: December 2004

The EOLE experiment is revisited to study turbulent processes in the lower stratosphere circulation from a Lagrangian viewpoint and to resolve a discrepancy on the slope of the atmospheric energy spectrum between the work of Morel and Larchevêque and recent studies using aircraft data. Relative dispersion of balloon pairs is studied by calculating the finite-scale Lyapunov exponent, an exit-time-based technique that is particularly efficient in cases in which processes with different spatial scales are interfering. The main goal is to reconciliate the EOLE dataset with recent studies supporting a k−5/3 energy spectrum in the 100–1000-km range. The results also show exponential separation at smaller scales, with a characteristic time of order 1 day, and agree with the standard diffusion of about 107 m2 s−1 at large scales. A remaining question is the origin of a k−5/3 spectrum in the mesoscale range between 100 and 1000 km.
The Angular Momentum Constraint on Climate Sensitivity and Downward Influence in the Middle Atmosphere
Authors: Shepherd Theodore G. , Shaw Tiffany A.
Published: December 2004

It is shown that under reasonable assumptions, conservation of angular momentum provides a strong constraint on gravity wave drag feedbacks to radiative perturbations in the middle atmosphere. In the time mean, radiatively induced temperature perturbations above a given altitude z cannot induce changes in zonal mean wind and temperature below z through feedbacks in gravity wave drag alone (assuming an unchanged gravity wave source spectrum). Thus, despite the many uncertainties in the parameterization of gravity wave drag, the role of gravity wave drag in middle-atmosphere climate perturbations may be much more limited than its role in climate itself. This constraint limits the possibilities for downward influence from the mesosphere. In order for a gravity wave drag parameterization to respect the momentum constraint and avoid spurious downward influence, any nonzero parameterized momentum flux at a model lid must be deposited within the model domain, and there must be no zonal mean sponge layer. Examples are provided of how violation of these conditions leads to spurious downward influence. For planetary waves, the momentum constraint does not prohibit downward influence, but it limits the mechanisms by which it can occur: in the time mean, downward influence from a radiative perturbation can only arise through changes in reflection and meridional propagation properties of planetary waves.
The Effect of Person Misfit on Classification Decisions
Authors: Hendrawan Irene , Glas Cees A. W. , Meijer Rob R.
Published: December 2004

The effect of person misfit to an item response theory model on a mastery/nonmastery decision was investigated. Furthermore, it was investigated whether the classification precision can be improved by identifying misfitting respondents using person-fit statistics. A simulation study was conducted to investigate the probability of a correct classification using different cutoff points, estimation methods, person-fit statistics, model violations, test lengths, and sample sizes. The effect of the presence of misfitting item score patterns on the item parameter estimates was also taken into account. Results showed that the effect of the presence of misfitting item score patterns on the classification of nonaberrant simulees was generally small (i.e., the classification precision for these simulees did not go down). Furthermore, for simulees classified as nonaberrant using a person-fit statistic, the classification decisions were comparable with the classification decisions for actual nonaberrant simulees. These results were comparable across different person-fit statistics and estimation methods.
English Language Learners’ Writing Practices and Attitudes
Authors: McCarthey Sarah J. , García Georgia Earnest
Published: December 2004

This study of English language learners, six Mandarin-speaking and five Spanish-speaking elementary students, revealed that students engaged in a variety of writing practices at home and school. A continuum of attitudes, from positive to negative, characterized students’attitudes toward writing in English and their native languages. Students’ writing practices and attitudes toward writing were influenced by home backgrounds and classroom contexts. Home background influences included parents’ educational backgrounds and income levels, plans for staying in the United States, support for writing at home, and cultural expectations. School and classroom factors included frequency and quality of opportunities for writing and teachers’ expectations for writing tasks. Implications of the study include the necessity to provide multiple opportunities for students to write for purposeful audiences in their native language as well as in English.
Creating the Subject of Portfolios
Authors: Scott Tony
Published: December 2004

This article presents research from a qualitative study of the way that reflective writing is solicited, taught, composed, and assessed within a state-mandated portfolio curriculum. The research situates reflective texts generated by participating students within the larger goals and bureaucratic processes of the school system. The study finds that reflective letters are a genre within the state curriculum that regulates the substance and tone of students’ reflections. At the classroom level, the genre provides a mode that students adopt with the assurance that their reflections will meet state evaluators’ expectations. At the bureaucratic level, the genre helps to continually validate the state’s portfolio curriculum through its strong encouragement of stylized narratives of progress. The study demonstrates the importance of understanding how large-scale assessments shape pedagogy and students’ writing.
“The Rhetoric of Literary Criticism” Revisited
Authors: Wilder Laura
Published: December 2004

Fahnestock and Secor’s “The Rhetoric of Literary Criticism” characterized literary criticism of the 1970s as conservative and self-celebratory. However, although literary theory has since undergone significant change, few rhetorical analyses of recent literary criticism as the preferred genre of a disciplinary discourse community have been conducted. This analysis of 28 articles of literary criticism published between 1999 and 2001 reveals that because of their flexibility, the stasis and special topoi conventions of earlier literary criticism continue to function. However, the shared values assumed in literary criticism have shifted away from a preference for isolated meditation on textual particulars. Instead, criticism is now portrayed as a conversation in which knowledge about literary texts and their historical contexts is socially negotiated and accumulative. Moreover, this scholarly project is frequently assumed to work toward social justice. The article ends with implications for understanding how knowledge is built within disciplinary communities.
Calcium and Phosphorous in Pediatric Parenteral Nutrition
Authors: Marks Katherine E. , Crill Catherine M.
Published: December 2004

Calcium (Ca) and phosphorus (P) are essential for various systemic functions, including bone mineralization. Adequate provision of Ca and P in pediatric parenteral nutrition (PN) solutions is necessary for skeletal growth and for the prevention of metabolic bone disease. The provision of adequate doses of Ca and P in pediatric PN solutions is complicated by the increased needs in preterm and term infants, solubility limitations, and venous access. Clinicians should be aware of the evidence that supports the optimal use of Ca and P in pediatric PN solutions, including studies that have evaluated dosing and solubility. The aim of this article is to review relevant literature and practices for the use of these two minerals in pediatric PN solutions. The vitamin D endocrine system, a critical component for Ca homeostasis and bone mineralization, is discussed, as well as clinical manifestations of metabolic bone disease and methods for its prevention, assessment, and treatment in pediatric patients receiving PN.
Homeland Security
Authors: Kemp Roger L.
Published: December 2004

This article examines state-of-the-art practices in the evolving field of homeland security. The increased level of intergovernmental cooperation is documented between all levels of government—cities, counties, and state, as well as the federal government. All of these levels of government are now cooperating to safeguard America to avert another terrorism incident such as the one that occurred on 9/11/01. The various levels of government are now cooperating with other special district and nonprofit organizations. Special districts include transit, water, and sewer. Nonprofit organizations include hospitals, health clinics, and other medical facilities. As time passes, the author predicts that the level of cooperation between public and nonprofit agencies will increase in the area of homeland security. Both sectors will be working together to safeguard America.
Urban Sprawl
Authors: Nechyba Thomas J , Walsh Randall P
Published: December 2004

The authors begin with an overview of the causes and consequences of urban sprawl in the twentieth century, focusing in particular on lower transportation costs and self-sorting of the population. By sprawl, we will mean the tendency toward lower city densities as city footprints expand. They next focus on four issues that raise clear efficiency and equity concerns: unproductive congestion on roads, high levels of metropolitan car pollution, the loss of open space amenities, and unequal provision of public goods and services across sprawling metropolitan suburbs that give rise to residential segregation and pockets of poverty. Finally, they consider the trade-offs inherent in some policies commonly proposed to address urban sprawl.

Throughout, a main theme of the discussion is that a full analysis of sprawl is made difficult by the lack of a usefully integrated economic model of urban economies. Along these lines, the authors conclude with some thoughts on possible future research agendas.
The Muddles over Outsourcing
Authors: Bhagwati Jagdish , Panagariya Arvind , Srinivasan T.N
Published: December 2004

Critics have muddled the public debate over offshore outsourcing by using the term interchangeably to refer to altogether different phenomena such as on-line purchase of services, direct foreign investment and, sometimes, all imports. We argue that clarity requires distinguishing among these various phenomena and define outsourcing explicitly as the services trade at arm's length that does not require geographical proximity of the buyer and the seller–the so-called Mode 1 services in the WTO terminology–conducted principally via the electronic mediums such as the telephone, fax and Internet. The definition is appropriate because this is the phenomenon that is relatively new and scary in public consciousness and has fueled the recent “outsourcing” debate. Under this definition, the total number of the U.S. jobs outsourced annually is minuscule and is expected to remain so over the next decade, even on a gross basis (i.e., without adjusting for the jobs in-sourced from the U.S.). The fears that offshore outsourcing will lead to high-value jobs being replaced by low-value jobs down the road are also argued here to be implausible in view of several qualitative arguments to the contrary. We also demonstrate that offshore outsourcing of Mode 1 services raises no new analytical issues, contrary to what many fear. Thus, it leads to gains from trade (with the standard caveats applicable to conventional trade in goods) and, in specific cases, to income-distribution effects.
The European Union: A Politically Incorrect View
Authors: Alesina Alberto , Perotti Roberto
Published: December 2004

In this paper, we present our view of the recent evolution of European integration. We first briefly describe the main features of the institution and decision making process in the European Union, with particular attention to the debate between federalists and super nationalists. We then identify two key issues in the process of European integration: 1) an emphasis on “institutional balance” based on a complex web of institutions with overlapping jurisdiction; 2) A conflict between a dirigiste versus a more laissez faire approach to government. We argue that the first problem leads to a lack of clarity in the allocation of powers between European institutions, confusion in the allocation of prerogatives between national governments and EU institutions, and lack of transparency and accountability. The dirigiste culture also manifests itself in an abundant production of verbose rhetoric, which in our view is far from innocuous and direct set the European policy debate in the wrong direction. We then study how these problems play out in 4 important areas: employment policies, culture and scientific research, foreign and defense policies, and fiscal policy. Finally, we study the implications of the recently proposed European Constitution a potential solution of these two problems.
Delineation of an interstitial 9q22 deletion in basal cell nevus syndrome
Authors: Boonen S.E. , Stahl D. , Kreiborg S. , Rosenberg T. , Kalscheuer V. , Larsen L.A. , Tommerup N. , Brøndum‐Nielsen K. , Tümer Z.
Published: December 2004

Basal cell nevus syndrome (Gorlin syndrome) is an autosomal dominant disorder characterized by the presence of multiple basal cell carcinomas (BCC), odontogenic keratocysts, palmoplantar pits, and calcification in the falx cerebri caused by mutational inactivation of the PTCH gene. In few cases, the syndrome is due to a microdeletion at 9q22. Using high‐resolution chromosome analysis we have identified a patient with the karyotype, 46,XY,del(9)(q21.3q31) de novo. He had typical clinical features consistent with basal cell nevus syndrome, but also additional features likely to be caused by loss of additional chromosomal material in this region. The deletion breakpoints were characterized with fluorescence in situ hybridization (FISH) analysis using BAC clones. The 15 Mb long deletion includes 87 RefSeq genes including PTCH. Hemizygosity of one or more genes might contribute to the additional symptoms observed in this patient. © 2004 Wiley‐Liss, Inc.
Natural history of cardiac involvement in geleophysic dysplasia
Authors: Scott A. , Yeung S. , Dickinson D.F. , Karbani G. , Crow Y.J.
Published: December 2004

Geleophysic dysplasia is an autosomal recessive short‐limbed, dysmorphic syndrome. The condition is frequently associated with cardiac valvular disease, which may result in secondary hypertrophy and cardiac failure. We describe two distantly related Pakistani children with classical features of geleophysic dysplasia. Pulmonary stenosis was recognized in both within a few months of birth. The younger child shows no signs of cardiac decompensation at the age of 7 years whilst her older cousin has developed a significant pulmonary gradient requiring surgical intervention in the second decade of life. The natural history of his disorder highlights that the cardiac involvement seen in apparently stable forms of geleophysic dysplasia is frequently progressive. © 2004 Wiley‐Liss, Inc.
Quantitative analysis of docetaxel in human plasma using liquid chromatography coupled with tandem mass spectrometry
Authors: Kuppens I. E. L. M. , van Maanen M. J. , Rosing H. , Schellens J. H. M. , Beijnen J. H.
Published: December 2004

An assay for the quantitative determination of docetaxel in human plasma is described. Docetaxel was extracted from the matrix using liquid–liquid extraction with ter‐butylmethylether, followed by high‐performance liquid chromatographic analysis using an alkaline eluent. Paclitaxel was used as internal standard. Positive ionization electrospray tandem mass spectrometry was performed for selective and sensitive detection. The method was validated according to the FDA guidelines on bioanalytical method validation. The validated range for docetaxel was from 0.25–1000 ng/mL using 200 µL plasma aliquots. The method requires only a limited volume (200 µL) of human plasma and the method can be applied in studies requiring a low lower limit of quantitation of 0.25 ng/mL. The assay was applied successfully in several clinical and pharmacological studies with docetaxel. Copyright © 2004 John Wiley & Sons, Ltd.
Forced Intercalation Probes (FIT Probes): Thiazole Orange as a Fluorescent Base in Peptide Nucleic Acids for Homogeneous Single‐Nucleotide‐Polymorphism Detection
Authors: Köhler Olaf , Jarikote Dilip Venkatrao , Seitz Oliver
Published: December 2004

Fluorescent base analogues in DNA are versatile probes of nucleic acid–nucleic acid and nucleic acid–protein interactions. New peptide nucleic acid (PNA) based probes are described in which the intercalator dye thiazole orange (TO) serves as a base surrogate. The investigation of six TO derivatives revealed that the linker length and the conjugation site decided whether a base surrogate conveys sequence‐selective DNA binding and whether fluorescence is increased or decreased upon single‐mismatched hybridization. One TO derivative conferred universal PNA–DNA base pairing while maintaining duplex stability and hybridization selectivity. TO fluorescence increased up to 26‐fold upon hybridization. In contrast to most other probes, in which fluorescence is invariant once hybridization had occurred, the emission of TO‐containing PNA probes is attenuated when forced to intercalate next to a mismatched base pair. The specificity of DNA detection is therefore not limited by the selectivity of probe–target binding and a DNA target can be distinguished from its single‐base mutant under nonstringent hybridization conditions. This property should be of advantage for real‐time quantitative PCR and nucleic acid detection within living cells.
Hierarchical, model‐based merging of multiple fragments for improved three‐dimensional segmentation of nuclei
Authors: Lin Gang , Chawla Monica K. , Olson Kathy , Guzowski John F. , Barnes Carol A. , Roysam Badrinath
Published: December 2004

Background

Automated segmentation of fluorescently labeled cell nuclei in three‐dimensional confocal images is essential for numerous studies, e.g., spatiotemporal fluorescence in situ hybridization quantification of immediate early gene transcription. High accuracy and automation levels are required in high‐throughput and large‐scale studies. Common sources of segmentation error include tight clustering and fragmentation of nuclei. Previous region‐based methods are limited because they perform merging of two nuclear fragments at a time. To achieve higher accuracy without sacrificing scale, more sophisticated yet computationally efficient algorithms are needed.

Methods

A recursive tree‐based algorithm that can consider multiple object fragments simultaneously is described. Starting with oversegmented data, it searches efficiently for the optimal merging pattern guided by a quantitative scoring criterion based on object modeling. Computation is bounded by limiting the depth of the merging tree.

Results

The proposed method was found to perform consistently better, achieving merging accuracy in the range of 92% to 100% compared with our previous algorithm, which varied in the range of 75% to 97%, even with a modest merging tree depth of 3. The overall average accuracy improved from 90% to 96%, with roughly the same computational cost for a set of representative images drawn from the CA1, CA3, and parietal cortex regions of the rat hippocampus.

Conclusion

Hierarchical tree model‐based algorithms significantly improve the accuracy of automated nuclear segmentation without sacrificing speed. © 2004 Wiley‐Liss, Inc.