bluuebunny/crossref_metadata_2025 huggingface dataset:
TH‐D‐M100J‐08: A Fast and High Spatial Resolution 1H Magnetic Resonance Spectroscopic Imaging Technique for Breast Cancer
Authors: Feng W , Yu Y , Zou Z , Mahmood R , Jiang Q , Xuan Y , Li T , Sehgal V , Blake C , Soulen R , Hu J
Published: July 2007

Purpose: We present our initial experience with in vivo high spatial resolution 1H MRSI of human breast lesions at a short echo time, by using recently developed echo‐filter suppression technique and the elliptical sampling scheme Method and Materials: The technique consists of three parts: optional inversion recovery, optional outer volume pre‐saturation (OVP), and an echo‐filter MRSI with a weighted k‐space sampling scheme. The simplest echo‐filter pulse sequence consists of a 900 RF pulse (or a series of pulses) to define the volume of interest (VOI), a delay TE/2, a frequency‐selective (FS) 1800 pulse, and another delay TE/2 with equally strong crusher gradients (G) on each side of the FS pulse. To improve sampling efficiency, a weighted k‐space sampling scheme is used to acquire the MRSI data set. Siemens whole‐body 1.5T Sonata is used, TR=1600 ms, TE=60 ms, Ave=8, acquisition time= 12.1 min, and a 60 Hz Gaussian FS pulse setting at Cho resonance (3.2 ppm). Results: To date, six studies from five patients with DCE‐MRI, 5 succeed, the spectra are well differentiated between biopsy proven tumor and control voxels. The spatial resolution here is only 0.59 cm3, the highest spatial resolution for in vivo 1H breast MRS at 1.5T to date. Excellent lipid and water suppression for in vivo 1H MRS was achieved. Aside from 8 Hz filter in the time domain and fast Fourier transform (FFT), no other processing was used to generate the spectra. Conclusion: As demonstrated, the proposed technique has the potential to overcome the difficulties for routine breast 1H MRS. It is robust (suppression technique is insensitive to magnetic field inhomogeneity), high spatial resolution (0.59 cc at 1.5T with a TE of only 60 ms), fast (acquisition time of 12 minutes), and even better at 3T (higher resolution and/or shorter TE).
TH‐D‐M100A‐01: What Does It Mean to Sign Attestation Statements?
Authors: Lieto R , Cameron F , Gerbi B
Published: July 2007

There are a number of situations where medical physicists must make statements attesting to the credentials of individuals or training programs. The U.S. Nuclear Regulatory Commission (NRC) recently revised its regulations in 10 CFR Part 35 for the training and experience (T&E) of an authorized user, an authorized medical physicist, and a radiation safety officer in the medical use of radioactive materials. The T&E regulations require an attestation by individuals on signed preceptor statements in order to be authorized/listed on a license to use radioactive materials. The attestation is a new, added requirement. What are the expectations of the individual who signs the attestation? Are there legal implications?

In order to acquire CAMPEP accreditation for either Graduate Medical Physics programs or Medical Physics Residency programs requires that the program submits a self study document stating explicitly what must be done to complete the program and showing documentation that these requirement have been met. After review of this self study, a survey team conducts an on‐site visit to verify that the program is operating in a manner consistent with what is described in the self study. If successful, accreditation is granted for a period of 5 years. Renewal requires submission of an updated self study. What happens to the individuals attesting to the validity of the program if graduates are involved in medical events? Is there liability for the institution or the individuals? This session will generate discussion on these topics.

Speakers:

Ralph Lieto, M.S., FAAPM — Implications of NRC Part 35 and Preceptor Statements — an AAPM Perspective.

Francis (Chip) Cameron, J.D. — Implications of NRC Part 35 and Preceptor Statements — an NRC Perspective.

Bruce Gerbi, Ph.D., FAAPM — CAMPEP Accreditation: stating expectations and verifying performance.
TH‐D‐AUD‐01: A Dynamic Dose Delivery Model for Gamma Knife Radiosurgery
Authors: Swanson N , Luan S , Li K , Ma L
Published: July 2007

Purpose: To develop a dynamic dose delivery model for Gamma Knife radiosurgery by taking advantage of the robotic patient positioning system in the latest Gamma Knife model. Methods and Material Gamma Knife has been the treatment of choice for many brain tumors and functional disorders. Current Gamma Knife radiosurgery is a ball‐packing approach, whose goal is to “pack” the different sized spherical high‐dose volumes into a target tumor volume. We have developed a dynamic Gamma Knife treatment scheme based on the concept of “dose‐painting” to take advantage of the new robotic patient positioning system on the latest Gamma Knife unit. In our scheme, the spherical high dose volume created by the Gamma Knife unit will be viewed as a 3D spherical “paintbrush,” and treatment planning reduces to finding the best route of the “paintbrush” to “paint” a 3D tumor volume. Under our dose‐painting concept, Gamma Knife radiosurgery becomes dynamic, where the patient is moving continuously under the robotic positioning system. Planning is modeled as a variation of the traveling salesman problem. Results: A theoretical study of dynamic Gamma Knife radiosurgery scheme has been carried out for a C‐shaped tumor volume. Dose distributions are calculated using an established analytical dose calculation engine. The dose distribution of the dynamic plan is calculated by fine interpolation from equally placed and equally weighted shots. The study showed that the new dynamic scheme can provide equal or superior dose distributions with significantly (> 40%) shortened treatment time. Conclusion: We have proposed and tested a dynamic delivery scheme for Gamma Knife radiosurgery using robotic patient positioning on the latest Gamma Knife model. A prototype study has been carried out. The results showed that our dynamic scheme provides equal or better dose distributions than current Gamma Knife method but with a significantly shortened treatment time.
TH‐D‐AUD‐02: Feasibility of Using High‐Field MRI, Functional Imaging, And Diffusion Tensor Images for Treatment Planning of SRS and IMRT
Authors: Li S , Jiang Q , Athiraman H , Jin J , Chen Q , Ryu S
Published: July 2007

Purpose: Loss of hearing, vision, and other cranial nerve functions can occur as complications of radiotherapy for brain and H&N tumors. Thus, we tested the feasibility of using high‐field magnetic resonance images, function magnetic resonance images (fMRI) and diffusion tensor images (DTI) in treatment planning to spare the cranial nerves and visual and auditory pathways. Method and Materials: Three‐dimensional T1‐weighted images (T1WI) and DTI from GE 3‐Tesla MR scanner were acquired on two volunteers. At the same position, The fMRI paradigm was performed by a block design in which music was binaurally presented through headphones. Structures including the nerves and fiber tracts (FT) and the tonotopic maps were defined in the DTI, fMRI, and T1WI using IPlan and BrainScan planning system (BrainLab). A small acoustic neuroma (SAN) and a large meningioma (LM) were created as targets in treatment plans. Subtracted DVHs were used for comparison of plans using dynamic arc radiotherapy (DART), conformal beam radiotherapy (CBRT), or intensity‐modulated beam radiotherapy (IMRT) with prescription dose (PD) at 96%, 90% or 80% isodose. Results: For the SAN, cranial nerves V, VII, VIII, IX and X near the tumor have been clearly defined in 3.0‐Tesla T1WI. DVHs indicate that IMRT was superior with the PD 96%, and DART was superior with PD 80%. For the LM, optic nerves and tracts, chiasm, and hearing response regions were all considered as OAR. IMRT plan provided a better target coverage while sparing critical structures. However, doses to chiasm and left optic nerve and tract reached above the tolerance level. Plans for preserving only one side optic pathway can reduce the hot spots by 40%.Conclusion: This study shows potential benefits of using new imaging techniques to reduce the hearing and vision losses for SRS and IMRT of brain and H&N tumors.
TH‐D‐AUD‐04: Development and Evaluation of An Ultrasound‐Guided Tracking and Gating System for Radiotherapy of Liver Metastases
Authors: Jacso F , Kouznetsov A , Smith W
Published: July 2007

Purpose: To investigate the feasibility of ultrasound imaging for tumor localization and respiratory gating for the treatment of liver metastases with radiotherapy. Method and Materials: An ultrasound‐guided tracking and gating system was developed for stereotactic body radiotherapy. We use an existing infrared marker system to track a moving ultrasound probe which is obtaining images of target motion throughout the respiratory cycle. The reconstructed ultrasound video of target motion in room coordinates is displayed with the treatment beam projection on the imaging plane to determine optimum gating levels.

To investigate the system, a phantom was constructed to model the respiratory motion of a liver tumor and also to enable imaging with ultrasound and kV x‐rays for comparison purposes. Ultrasound video and orthogonal localizing x‐ray images were taken of the same moving tumor model. We compared the timing to an existing clinical system. Results: Ultrasound has a better soft tissue contrast than x‐ray and is capable of producing up to 26 fps video. We measured a time delay of 22 ± 11 ms at 2.4 s period, and 30 ± 25 ms at 4.8 s period of breathing motion. The same figures for the clinical x‐ray system were 81± 29 ms at 2.4 s, and 5 ± 18 ms at 4.8 s period. This was comparable to our system's delay. None of the measured delays in our system would compromise planning margins, the largest observed error extending to only 1.1 mm. Conclusion: An ultrasound‐guided tracking and gating system and a moving phantom was developed. The image quality and timing delay of the system was equivalent to that of an existing clinical solution. Further investigation needed to apply three‐dimensional gating signal and to test imaging on actual patients before clinical application.

Research sponsored by the Alberta Cancer Foundation.
A PERFORMANCE MODEL OF DISHA ROUTING IN K-ARY N-CUBE NETWORKS
Authors: KHONSARI A. , SHAHRABI A. , OULD-KHAOUA M.
Published: July 2007

A number of analytical models for predicting message latency in k-ary n-cubes have recently been reported in the literature. Most of these models, however, have been discussed for adaptive routing algorithms based on deadlock avoidance, e.g. Duato's routing. Several research studies have empirically demonstrated that routing algorithms based on deadlock recovery offer maximal adaptivity that can result in considerable improvement in network performance. Disha is an example of a true fully adaptive routing algorithm that uses minimal hardware to implement a simple and efficient progressive method to recover from potential deadlocks. This paper proposes a new analytical model of Disha in wormhole-routed k-ary n-cubes. Simulation experiments confirm that the proposed model exhibits a good degree of accuracy for various networks sizes and under different traffic conditions.
PHOTON–AXION CONVERSION CROSS-SECTIONS IN A RESONANT CAVITY
Authors: SOA DANG VAN , LONG HOANG NGOC , THUC LE NHU
Published: July 2007

Photon–axion conversions in the resonant cavity with the lowest mode are considered in detail by the Feynman diagram method. The differential cross-sections are presented and numerical evaluations are given. It is shown that there is a resonant conversion for the considered process, in which the conversion cross-sections are much larger than those of the wave guide in the same conditions. Some estimates for experimental conditions are given from our results.
NEUTRINO PARAMETER SPACE FOR A VANISHING ee ELEMENT IN THE NEUTRINO MASS MATRIX
Authors: DEV S. , KUMAR SANJEEV
Published: July 2007

The consequences of a texture zero at the ee entry of neutrino mass matrix in the flavor basis, which also implies a vanishing effective Majorana mass for neutrinoless double beta decay, have been studied for Majorana neutrinos. The neutrino parameter space under this condition has been constrained in the light of all available neutrino data including the CHOOZ bound on [Formula: see text].
TOWARDS UNDERSTANDING BROAD DEGENERACY IN NON-STRANGE MESONS
Authors: AFONIN S. S.
Published: July 2007

The spectroscopic regularities of modern empirical data on the non-strange mesons up to 2.4 GeV can be summarized as a systematic clustering of states near certain values of energy. It is getting evident that some unknown X-symmetry triggers the phenomenon. We review the experimental status of this symmetry and recent theoretical attempts put forward for explanation of broad degeneracy.
In-Medium Kaon Dispersion Relation and Dilepton Production
Authors: Fujii Hirotsugu , Tatsumi Toshitaka
Published: July 2007

Rate of dilepton production from kaon annihilation is proposed to probe the kaon properties at finite densities. The chiral model predicts that the interaction between K± and nucleon is attractive in average, which leads to enhancement of the rate of dilepton production from kaon annihilation in heavy ion collisions, especially in the invariant mass region near the Φ meson, assuming the vector meson dominance model. Softening of the kaon dispersion relation in nuclear medium has a sizable effect on the dilepton production rate, which may be detected in experiments.
Fragility as a Measure of Dynamic Inhomogeneity of Glass Formers
Authors: Novikov Vladimir , Rüssler Ernst , Malinovsky Valery
Published: July 2007

The structure and dynamics of glass formers are spatially inhomogeneous with typical scale of nanometers. The influence of this inhomogeneity on the glass transition is considered. Using Lindemann criterion of melting, the locally liquid- and solid-like particles are defined and a percolation problem for liquid and solid clusters is formulated. On the basis of percolation theory it is shown that in strong glass formers the dynamic inhomogeneity is higher than in fragile ones. The standard deviation of the lognormal spatial distribution of the mean square atomic displacements (r2) is found to be equal to 0.1÷0.2 for fragile glass formers, 0.5 for intermediate glycerol and 0.7 for strong B2O3. The comparison with the free volume size distribution in a fragile polymer shows a good agreeement with the predictions of the model.
Detection of MAGE-A Transcripts in Bone Marrow Is an Independent Prognostic Factor in Operable Non–Small-Cell Lung Cancer
Authors: Sienel Wulf , Mecklenburg Ingo , Dango Sebastian , Ehrhardt Peter , Kirschbaum Andreas , Passlick Bernward , Pantel Klaus
Published: July 2007

Purpose: MAGE-A gene expression in humans is mostly restricted to tumor cells, and the role of MAGE-A transcripts and peptides as diagnostic markers and therapeutic targets is currently under investigation. Thus far, the clinical relevance of MAGE-A transcripts as marker for disseminated tumor cells in bone marrow of patients with operable lung cancer without overt metastases is still unclear.

Experimental Design: Preoperative bone marrow aspirates from 50 consecutive patients with operable non–small-cell lung cancer free of distant metastases (i.e., pT1-4 pN0-2 M0 R0) were admitted to the study. Each bone marrow sample was divided and examined using multimarker MAGE-A reverse transcription-PCR (RT-PCR) and immunocytochemical staining with the anti-pancytokeratin antibody A45-B/B3. Multimarker MAGE-A RT-PCR consisted of multiple subtype-specific nested RT-PCRs with primers for MAGE-A1, MAGE-A2, MAGE-A3/6, MAGE-A4, and MAGE-A12. The median follow-up duration was 92 months (range, 18-110 months).

Results: Twenty-six (52%) lung cancer patients harbored MAGE-A transcripts in their bone marrow, as opposed to none of the 30 healthy controls tested. In all 7 patients with immunocytochemically positive bone marrow, MAGE-A transcripts were also detected. All different MAGE-A subtypes (MAGE-A1, MAGE-A2, MAGE-A3/6, MAGE-A4, and MAGE-A12) were observed. Sixty-five percent of patients with MAGE-A transcripts in bone marrow exhibited only one subtype. Univariate (P = 0.03, log-rank-test) and multivariate survival analysis showed that MAGE-A transcripts in bone marrow were associated with poor outcome in pN0 patients (P = 0.02; relative risk, 7.6).

Conclusions: Detection of MAGE-A transcripts in bone marrow predicts an unfavorable outcome in patients with early-stage operable lung cancer. This finding indicates that MAGE-A transcripts are clinically relevant markers of micrometastatic spread in lung cancer and supports further investigation of MAGE-A as potential future therapeutic target.
Effective Relief of Malignant Ascites in Patients with Advanced Ovarian Cancer by a Trifunctional Anti-EpCAM × Anti-CD3 Antibody: A Phase I/II Study
Authors: Burges Alexander , Wimberger Pauline , Kümper Carolin , Gorbounova Vera , Sommer Harald , Schmalfeldt Barbara , Pfisterer Jacobus , Lichinitser Michail , Makhson Anatoliy , Moiseyenko Vladimir , Lahr Angelika , Schulze Elisabeth , Jäger Michael , Ströhlein Michael A. , Heiss Markus Maria , Gottwald Thomas , Lindhofer Horst , Kimmig Rainer
Published: July 2007

Purpose: Malignant ascites in ovarian carcinoma patients is associated with poor prognosis and reduced quality of life. The trifunctional antibody catumaxomab (anti-EpCAM × anti-CD3) enhances the antitumor activity by redirecting T cells and Fcγ receptor I/III–positive accessory cells to the tumor. This multicenter phase I/II dose-escalating study investigated tolerability and efficacy of i.p. catumaxomab application in ovarian cancer patients with malignant ascites containing epithelial cell adhesion molecule (EpCAM)–positive tumor cells.

Experimental Design: Twenty-three women with recurrent ascites due to pretreated refractory ovarian cancer were treated with four to five i.p. infusions of catumaxomab in doses of 5 to 200 μg within 9 to 13 days.

Results: The maximum tolerated dose was defined at 10, 20, 50, 200, and 200 μg for the first through fifth doses. Side effects included transient fever (83%), nausea (61%), and vomiting (57%), mostly CTCAE (Common Terminology Criteria for Adverse Events) grade 1 or 2. A total of 39 grade 3 and 2 grade 4 treatment-related adverse events (AE), 9 of them after the highest dose level (200 μg), were observed in 16 patients. Most AEs were reversible without sequelae. Treatment with catumaxomab resulted in significant and sustained reduction of ascites flow rate. A total of 22/23 patients did not require paracentesis between the last infusion and the end of study at day 37. Tumor cell monitoring revealed a reduction of EpCAM-positive malignant cells in ascites by up to 5 log.

Conclusion: I.p. immunotherapy with catumaxomab prevented the accumulation of ascites and efficiently eliminated tumor cells with an acceptable safety profile. This suggests that catumaxomab is a promising treatment option in ovarian cancer patients with malignant ascites.
Targeting the Phosphatidylinositol 3-Kinase Pathway in Multiple Myeloma
Authors: Younes Hashem , Leleu Xavier , Hatjiharissi Evdoxia , Moreau Anne-Sophie , Hideshima Teru , Richardson Paul , Anderson Kenneth C. , Ghobrial Irene M.
Published: July 2007

Multiple myeloma is a plasma cell neoplasm with a median survival of 3 to 5 years. Recent advances have improved patient outlook, but the disease remains incurable. Therefore, continued efforts to develop new therapies that target aberrant signaling pathways are needed. The phosphatidylinositol 3-kinase pathway regulates apoptosis, cell cycle regulation, and tumor proliferation. This pathway is constitutively activated in multiple myeloma and its inhibition induces apoptosis. Advances in understanding the signaling cascades mediating proliferation and survival of multiple myeloma cells have markedly improved the treatment of this disease. In this article, we review the role of the phosphatidylinositol 3-kinase/Akt pathway in the pathogenesis of multiple myeloma and the potential therapeutic implications of targeting this pathway in the treatment of multiple myeloma.
A New Model of Patient Tumor-Derived Breast Cancer Xenografts for Preclinical Assays
Authors: Marangoni Elisabetta , Vincent-Salomon Anne , Auger Nathalie , Degeorges Armelle , Assayag Franck , de Cremoux Patricia , de Plater Ludmilla , Guyader Charlotte , De Pinieux Gonzague , Judde Jean-Gabriel , Rebucci Magali , Tran-Perennou Carine , Sastre-Garau Xavier , Sigal-Zafrani Brigitte , Delattre Olivier , Diéras Véronique , Poupon Marie-France
Published: July 2007

Purpose: To establish a panel of human breast cancer (HBC) xenografts in immunodeficient mice suitable for pharmacologic preclinical assays.

Experimental Design: 200 samples of HBCs were grafted into Swiss nude mice. Twenty-five transplantable xenografts were established (12.5%). Their characterization included histology, p53 status, genetic analysis by array comparative genomic hybridization, gene expression by Western blotting, and quantitative reverse transcription-PCR. Biological profiles of nine xenografts were compared with those of the corresponding patient's tumor. Chemosensitivities of 17 xenografts to a combination of Adriamycin and cyclophosphamide (AC), docetaxel, trastuzumab, and Degarelix were evaluated.

Results: Almost all patient tumors established as xenografts displayed an aggressive phenotype, i.e., high-grade, triple-negative status. The histology of the xenografts recapitulated the features of the original tumors. Mutation of p53 and inactivation of Rb and PTEN proteins were found in 83%, 30%, and 42% of HBC xenografts, respectively. Two HBCx had an ERBB2 (HER2) amplification. Large variations were observed in the expression of HER family receptors and in genomic profiles. Genomic alterations were close to those of original samples in paired tumors. Three xenografts formed lung metastases. A total of 15 of the 17 HBCx (88%) responded to AC, and 8 (47%) responded to docetaxel. One ERBB2-amplified xenograft responded to trastuzumab, whereas the other did not. The drug response of HBC xenografts was concordant with that of the patient's tumor in five of seven analyzable cases.

Conclusions: This panel of breast cancer xenografts includes 15 triple-negative, one ER positive and 2 ERBB2 positive. This panel represents a useful preclinical tool for testing new agents and protocols and for further exploration of the biological basis of drug responses.
Cancer Vaccines: Moving Beyond Current Paradigms
Authors: Schlom Jeffrey , Arlen Philip M. , Gulley James L.
Published: July 2007

The field of cancer vaccines is currently in an active state of preclinical and clinical investigations. Although no therapeutic cancer vaccine has to date been approved by the Food and Drug Administration, several new paradigms are emerging from recent clinical findings both in the use of combination therapy approaches and, perhaps more importantly, in clinical trial design and end point analyses. This article will review recent clinical trials involving several different cancer vaccines from which data are emerging contrasting classic “tumor response” (Response Evaluation Criteria in Solid Tumors) criteria with “patient response” in the manifestation of increased patient survival post-vaccine therapy. Also described are several strategies in which cancer vaccines can be exploited in combination with other agents and therapeutic modalities that are quite unique when compared with “conventional” combination therapies. This is most likely due to the phenomena that (a) cancer vaccines initiate a dynamic immune process that can be exploited in subsequent therapies and (b) both radiation and certain chemotherapeutic agents have been shown to alter the phenotype of tumor cells as to render them more susceptible to T-cell–mediated killing. Consequently, evidence is emerging from several studies in which patient cohorts who first receive a cancer vaccine (as contrasted with control cohorts) benefit clinically from subsequent therapies.
Urban Aerosol Impacts on Downwind Convective Storms
Authors: van den Heever Susan C. , Cotton William R.
Published: July 2007

The impacts of urban-enhanced aerosol concentrations on convective storm development and precipitation over and downwind of St. Louis, Missouri, are investigated. This is achieved through the use of a cloud-resolving mesoscale model, in which sophisticated land use processes and aerosol microphysics are both incorporated. The results indicate that urban-forced convergence downwind of the city, rather than the presence of greater aerosol concentrations, determines whether storms actually develop in the downwind region. Once convection is initiated, urban-enhanced aerosols can exert a significant effect on the dynamics, microphysics, and precipitation produced by these storms. The model results indicate, however, that the response to urban-enhanced aerosol depends on the background concentrations of aerosols; a weaker response occurs with increasing background aerosol concentrations. The effects of aerosols influence the rate and amount of liquid water and ice produced within these storms, the accumulated surface precipitation, the strength and timing of the updrafts and downdrafts, the longevity of the updrafts, and the strength and influence of the cold pool. Complex, nonlinear relationships and feedbacks between the microphysics and storm dynamics exist, making it difficult to make definitive statements about the effects of urban-enhanced aerosols on downwind precipitation and convection. Because the impacts of urban aerosol on downwind storms decrease with increasing background aerosol concentrations, generalization of these results depends on the unique character of background aerosol for each urban area. For urban centers in coastal areas where background aerosol concentrations may be very low, it is speculated that urban aerosol can have very large influences on convective storm dynamics, microphysics, and precipitation.
A Review and Comparison of Changepoint Detection Techniques for Climate Data
Authors: Reeves Jaxk , Chen Jien , Wang Xiaolan L. , Lund Robert , Lu Qi Qi
Published: July 2007

This review article enumerates, categorizes, and compares many of the methods that have been proposed to detect undocumented changepoints in climate data series. The methods examined include the standard normal homogeneity (SNH) test, Wilcoxon’s nonparametric test, two-phase regression (TPR) procedures, inhomogeneity tests, information criteria procedures, and various variants thereof. All of these methods have been proposed in the climate literature to detect undocumented changepoints, but heretofore there has been little formal comparison of the techniques on either real or simulated climate series. This study seeks to unify the topic, showing clearly the fundamental differences among the assumptions made by each procedure and providing guidelines for which procedures work best in different situations. It is shown that the common trend TPR and Sawa’s Bayes criteria procedures seem optimal for most climate time series, whereas the SNH procedure and its nonparametric variant are probably best when trend and periodic effects can be diminished by using homogeneous reference series. Two applications to annual mean temperature series are given. Directions for future research are discussed.
Downscaling of Seasonal Precipitation for Crop Simulation
Authors: Robertson Andrew W. , Ines Amor V. M. , Hansen James W.
Published: July 2007

A nonhomogeneous hidden Markov model (NHMM) is used to make stochastic simulations of March–August daily rainfall at 10 stations over the southeastern United States, 1923–98. Station-averaged observed daily rainfall amount is prescribed as an input to the NHMM, which is then used to disaggregate the rainfall in space. These rainfall simulations are then used as inputs to a Crop Estimation through Resource and Environment Synthesis (CERES) crop model for maize. Regionally averaged yields derived from the NHMM rainfall simulations are found to correlate very highly (r = 0.93) with those generated by the crop model using observed rainfall; stationwise correlations range between 0.44 and 0.74. Rainfall and crop simulations are then constructed under increasing degrees of temporal smoothing applied to the regional rainfall input to the NHMM, designed to exclude the submonthly weather details that would be unpredictable in seasonal climate forecasts. Regional yields are found to be remarkably insensitive to this temporal smoothing; even with 90-day low-pass-filtered inputs to the NHMM, resulting yields are still correlated at 0.85 with the baseline simulation, whereas stationwise correlations range between 0.18 and 0.68. From these findings, it is expected that regional maize yields over the southeastern United States will be largely insensitive to year-to-year details of subseasonal rainfall variability; they should be downscalable, in principle, using an NHMM from climate forecasts archived at daily resolution, with the important caveat that the latter need to be skillful enough at the 90-day time scale. As a by-product of the analysis, subseasonal-to-interdecadal summer rainfall variability over the southeastern United States is interpretable in terms of six discrete weather states indicative of a monsoonlike climate regime. Low-simulated-yield years are found to be associated with delayed summer rainfall onset.
Sea Surface Winds over the Mediterranean Basin from Satellite Data (2000–04): Meso- and Local-Scale Features on Annual and Seasonal Time Scales
Authors: Zecchetto S. , De Biasio F.
Published: July 2007

This paper investigates the mean spatial features of the winds in the Mediterranean and Black Seas using the wind fields observed by the SeaWinds scatterometer. Five years (2000–04) of data have been analyzed on annual and seasonal basis, with particular attention paid to the meso- and local scales. The fields show the existence of structured regional wind systems—in particular, the mistral in the western Mediterranean and the etesians in the Levantine Basin, which are characterized, respectively, by high wind variability and moderate steadiness and by low wind variability and high steadiness. Estimated seasonal mean wind stress τ fields show that the values falling in the top range 0.15 < τ < 0.20 N m−2 affect a large portion of the Mediterranean Basin in winter, in the belt extending from the Gulf of Lion up to the Levantine Basin and the northern Black Sea. In the other seasons, only few regions experience such high values of τ. The analysis of the wind vorticity shows and quantifies the main cyclonic and anticyclonic circulations, and the study of the joint features of wind stress and vorticity has identified the strongest and most persisting local-scale wind circulations produced by the interaction between the wind flow and the orography. They occur at the lee side of Sardinia–Corse and Crete–Rhodos Islands and persist in all seasons, with some seasonal variation in strength and extent. The areas affected by the orographic disturbances are characterized by high values of wind stress and by a structure of vorticity showing alternating areas of cyclonic and anticyclonic circulations, whose strength is comparable to those of the regional-scale cyclones.
Best Practice Guidelines on Prevention Practice, Research, Training, and Social Advocacy for Psychologists
Authors: Hage Sally M. , Romano John L. , Conyne Robert K. , Kenny Maureen , Matthews Connie , Schwartz Jonathan P. , Waldo Michael
Published: July 2007

Preventive interventions have been shown to successfully aid the development of children, youths, and adults and avert maladjustment in individuals at risk for negative outcomes. Continued scientific advancement of preventive interventions is crucial to further the health of U.S. children, youths, and families. This article presents 15 best practice guidelines on prevention practice, research, training, and social advocacy for psychology. These guidelines articulate clear standards and a framework for moving the profession toward improving the well-being of a greater number of individuals and communities. The guidelines are intended to assist psychologists in evaluating their preparation for engaging in prevention work and in furthering their understanding through increased knowledge, skills, and experience in prevention.
Self-Configured Fair Queueing
Authors: Yang Jui-Pin
Published: July 2007

Many core-stateless mechanisms have been proposed to resolve the scalability problem in the core routers. However, they place considerable reliance on the edge routers or anterior core routers to mark correct flow information in corresponding packets. As a result, the condition of incorrect flow information may severely degrade the fairness among different flows. To achieve the robust fairness, an approximately core-stateless fair sharing mechanism, self-configured fair queuing (SCFQ) is proposed in this paper. This mechanism is mainly composed of two rate estimators; one estimator is used to estimate the arrival rate of the malicious flows that can be adopted to emend the incorrect flow information of the arrival packets. The other one is used to estimate the fair share rate. Computer Simulation is applied to compare the fairness of the SCFQ, core-stateless fair queuing (CSFQ), linear fair sharing estimation (LFSE), deficit round robin (DRR), and first in first out (FIFO). From the simulation results, the SCFQ is capable of supporting much better fairness than that of other compared mechanisms under a variety of traffic conditions. Also, the overhead of the SCFQ is low, so it is very suitable to be deployed in high-speed core routers.
Directions for Violence and Sexual Risk Assessment in Correctional Psychology
Authors: Kroner Daryl G. , Mills Jeremy F. , Reitzel Lorraine R. , Dow Edward , Aufderheide Dean H. , Railey Michael G.
Published: July 2007

This review covers the current contributions to risk assessment. The fields of static and dynamic variables are covered for both violent and sexual offenders. The research on risk management strategies and how risk assessment is communicated to decision makers is also reviewed. Methodological considerations in risk-assessment research focus on incorporating time until failure, multiple failures, and severity of failure as outcomes. For each of the areas covered, future research directions are formulated.
Systemic Issues and Correctional Outcomes
Authors: Clements Carl B. , Althouse Richard , Ax Robert K. , Magaletta Phillip R. , Fagan Thomas J. , Wormith J. Stephen
Published: July 2007

Professional work in corrections is beset with issues ranging from conflicting justice-system goals, lack of resources, role confusion, ethical dilemmas, and an atmosphere often hostile to empirical research and program evaluation. The authors describe several systemic issues that impact the work of correctional psychologists and their effectiveness. Recognizing the critical need for evidence-based clinical practice, the authors argue, in addition, that the correctional psychologist's mission should be expanded to include macro-level systems issues. These include questions of social responses to crime, unintended consequences of correctional practice, the need for research on institutional policy, and methods for system-wide evaluation of correctional programs and settings. The authors describe the nature and scope of each issue and offer a suggested research agenda.
Multivariate longitudinal methods for studying developmental relationships between depression and academic achievement
Authors: Grimm Kevin J.
Published: July 2007

Recent advances in methods and computer software for longitudinal data analysis have pushed researchers to more critically examine developmental theories. In turn, researchers have also begun to push longitudinal methods by asking more complex developmental questions. One such question involves the relationships between two developmental processes. In this situation, choosing a longitudinal method is not obvious and should depend on specific hypotheses and research questions. This article outlines three common bivariate longitudinal models, including the bivariate latent growth curve model, the latent growth curve with a time-varying covariate, and the bivariate dual change score growth model, and illustrates their use by modeling how the development of depression is related to the development of achievement. Each longitudinal model is fitted to repeated measurements of children's depression and achievement from the National Longitudinal Survey of Youth (NLSY) data set in order to examine differing developmental relationships, and show how the developmental questions are answered by each longitudinal technique. The results from the longitudinal models appear to be somewhat at odds with one another regarding the developmental relationships between achievement and depression, but the conclusions are actually correct solutions to different developmental questions. These results highlight the need for researchers to match their research questions with model selection.
The application of Bayesian analysis to issues in developmental research
Authors: Walker Lawrence J. , Gustafson Paul , Frimer Jeremy A.
Published: July 2007

This article reviews the concepts and methods of Bayesian statistical analysis, which can offer innovative and powerful solutions to some challenging analytical problems that characterize developmental research. In this article, we demonstrate the utility of Bayesian analysis, explain its unique adeptness in some circumstances, address some concerns and misconceptions about the approach, and illustrate some applications of Bayesian analysis to issues that frequently arise in developmental research. The illustrations of the approach provided here reflect several important issues within the domain of moral reasoning development (such as assessing patterns of stage change over time); however, the methods are readily applicable across content areas in developmental research.
Bayesian analysis of longitudinal data using growth curve models
Authors: Zhang Zhiyong , Hamagami Fumiaki , Lijuan Wang Lijuan , Nesselroade John R. , Grimm Kevin J.
Published: July 2007

Bayesian methods for analyzing longitudinal data in social and behavioral research are recommended for their ability to incorporate prior information in estimating simple and complex models. We first summarize the basics of Bayesian methods before presenting an empirical example in which we fit a latent basis growth curve model to achievement data from the National Longitudinal Survey of Youth. This step-by-step example illustrates how to analyze data using both noninformative and informative priors. The results show that in addition to being an alternative to the maximum likelihood estimation (MLE) method, Bayesian methods also have unique strengths, such as the systematic incorporation of prior information from previous studies. These methods are more plausible ways to analyze small sample data compared with the MLE method.
A Boon or a Bane? The Role of Civil Society in Third- and Fourth-Wave Democracies
Authors: Tusalem Rollin F.
Published: July 2007

Since Putnam published Making Democracy Work, his seminal work on the effect of civic associationalism in promoting better institutional performance, many other studies have confirmed the deleterious effects of civil society in promoting democratic breakdown and malperformance. To solve the empirical puzzle as to whether civil society is a bane or boon for democracies, this article examines the effect of the pre-transitional strength and post-transitional density of civil society on state institutional performance among more than 60 states since the third wave. The results show that the strength of civil society prior to transition and its density post-transition not only play a significant role in the deepening of political freedoms and civil liberties among transitional citizens, but also lead to better institutional performance. Hence, Putnam's major findings can be extended in the context of third- and fourth-wave democracies.
Flow
Authors: Jennings Tracy
Published: July 2007

Flow was designed with the intention that dress should compliment, not exaggerate, the natural female form. It connects with nature, not the artificial. In nature, as in the female silhouette, there are few angles. As they flow around the body, the bias lines accentuate existing curves. The color of the garment suggests natural elements such as copper, bronze, and gold. Flow is made of satin-back crepe which allows for subtle contrast of shades, lines, and texture.
Reconstruction of Holocene foreland progradation using optically stimulated luminescence (OSL) dating: an example from Dungeness, UK
Authors: Roberts H.M. , Plater A.J.
Published: July 2007

Dungeness Foreland, southeast UK, is comprised of a series of distinctive gravel ridges overlying sub- and intertidal sands. The successful application of optically stimulated luminescence (OSL) to the Holocene sub- and intertidal sands at Dungeness provides a well-resolved chronology (precision ~5%) for exploring the sedimentary response of a gravel foreland to changes in sea level, storms, sediment supply and coastal dynamics. The nature of foreland progradation at Dungeness is revealed through a three-dimensional network of 35 new quartz OSL ages, and these data also constrain the timing of gravel emplacement. The OSL chronology places the early formation of the underlying shoreface in the west at ~5000 years ago, with ages decreasing progressively eastwards to ~2000 years ago beneath the main body of the present foreland, and 1000—600 years ago under the present-day ness in the east. The uppermost OSL ages for the subgravel sand unit provide maximum limiting ages for emplacement of the gravel, which together with14C ages from organic deposits on the gravel surface provide bracketing ages for the deposition of the gravel. The short lag time between shoreface sand deposition and gravel ridge formation is indicative of a high degree of dependency of gravel foreland progradation on the pre-existence of an emergent sand substrate. Sigmoidal isochrons constructed using the subgravel sand OSL ages, and consideration of down-core OSL ages, demonstrates nonlinearity in coastal response; this is expressed in the form of changes in the direction of foreland progradation rather than temporal changes in sedimentation rate.
Conversion of biomass to charcoal and the carbon mass balance from a slash-and-burn experiment in a temperate deciduous forest
Authors: Eckmeier Eileen , Rösch Manfred , Ehrmann Otto , Schmidt Michael W.I. , Schier Wolfram , Gerlach Renate
Published: July 2007

Anthropogenic burning, including slash-and-burn, was deliberately used in (pre)historic Central Europe. Biomass burning has affected the global carbon cycle since, presumably, the early Holocene. The understanding of processes and rates of charcoal formation in temperate deciduous forests is limited, as is the extent of prehistoric human impact on the environment. We took advantage of an experimental burning to simulate Neolithic slash-and-burn, and we quantified the biomass fuel and charcoal produced, determined the resulting distribution of the charcoal size fractions and calculated the carbon mass balance. Two-thirds of the charcoal particles (6.71 t/ha) were larger than 2000 μm and the spatial distribution of charcoal was highly variable (15—90% per m2). The conversion rate of the biomass fuel to charcoal mass was 4.8%, or 8.1% for the conversion of biomass carbon to charcoal carbon, and 58.4 t C/ha was lost during the fire, presumably as a component of aerosols or gases.
Recombinant Factor C competes against LBP to bind lipopolysaccharide and neutralizes the endotoxicity
Authors: Li Peng , Ho Bow , Ding Jeak Ling
Published: July 2007

Endotoxin-mediated inflammation and septic shock remains a grave challenge to human healthcare management. It is, therefore, a worthwhile effort to develop anti-lipopolysaccharide (LPS) strategies to prevent downstream effects. Here, we demonstrate that purified recombinant Factor C (rFC) cloned from the horseshoe crab, binds LPS with high affinity, preventing it from binding a peptide derived from the human LPS-binding protein (LBP). Factor C is an innate immune defense protein present in the horseshoe crab hemocytes. The full-length rFC was found to be more efficacious in blocking LBP-mediated downstream effects than either of the individual LPS-binding peptides (Sushi 1 and Sushi 3) derived from rFC. When added to human macrophage culture, rFC blocks the LPS-induced phosphorylation of p38, which, in turn, inhibits the consequential overexpression of TNF-α and IL-8. The tandem arrangement of the LPS-binding Sushi domains in the Factor C molecule appears to be required for the synergy and amplification of LPS-binding in vivo to achieve such high affinity for LPS. Thus, rFC binds and neutralizes LPS to arrest signal transduction via the p38 pathway. The rFC does not show acute cytotoxicity and could be a potential lead for further development into an endotoxin-antagonist to inhibit inflammation and septic shock.
Potentiation of Toll-like receptor-induced cytokine production by (1→3)-β-D-glucans: implications for the monocyte activation test
Authors: Kikkert Robert , Bulder Ingrid , de Groot Els R. , Aarden Lucien A. , Finkelman Malcolm A.
Published: July 2007

The monocyte activation test (MAT) has been introduced as an alternative for the detection of pyrogens in pharmaceuticals with the rabbit pyrogen test or the Limulus amebocyte lysate (LAL) test. The basis of the MAT is that pyrogens, via Toll-like receptors (TLRs) expressed on monocytes, stimulate cytokine production. Here, we report that, at concentrations that did not induce whole blood cytokine production when tested separately, (1→3)-β-D-glucans powerfully co-stimulated cytokine production (IL-6/IL-8) induced by ligands for TLR1/2, TLR2/6, TLR4, and TLR5. Experiments were performed to investigate the involvement of particular (1→3)-β-D-glucan receptors such as dectin-1. Spleen tyrosine kinase (Syk) inhibition attenuated the potentiating effects of (1→3)-β-D-glucans on TLR-induced cytokine production, suggesting that dectin-1 was involved. However, experiments with low molecular (1→3)-β-D-glucans such as laminarin argued against the involvement of dectin-1 in the co-stimulatory effects of (1→3)-β-D-glucans. Thus, although the receptors involved in the co-stimulatory actions of (1→3)-β-D-glucans on TLR-induced cytokine production are yet to be elucidated, it is clear that (1→3)-β-D-glucans may greatly affect MAT results and, when undetected in pharmaceuticals, may give rise to serious side-effects in patients co-exposed to other elicitors of innate immunity, such as during infections.
Comparing ADHD in Velocardiofacial Syndrome to Idiopathic ADHD
Authors: Antshel Kevin M. , Faraone Stephen V. , Fremont Wanda , Monuteaux Michael C. , Kates Wendy R. , Doyle Alysa , Mick Eric , Biederman Joseph
Published: July 2007

Objective: Background: Children with velocardiofacial syndrome (VCFS), a contiguous deletion syndrome, have an increased prevalence of attention deficit/hyperactivity disorder (ADHD). Method: The authors compared youth with VCFS+ADHD (from the SUNY Upstate VCFS Research Program) to those with ADHD but not VCFS (from the Massachusetts General Hospital Longitudinal Family Studies of ADHD). Results: Children with VCFS+ADHD were more likely to be diagnosed with the inattentive subtype and differed from idiopathic ADHD in the frequency of several inattentive symptoms that appear linked to general cognitive functioning. After controlling for IQ differences, parents of children with VCFS+ADHD endorsed more thought and social problems on a rating checklist. Patterns of comorbidity also differed between the two groups of children with ADHD: Children with idiopathic ADHD had higher rates of comorbid major depression and disruptive behavior disorders. Conclusion: Children with VCFS+ADHD may have a different profile of ADHD symptoms and comorbidity when compared to children with idiopathic ADHD. (J. of Att. Dis. 2007; 11(1) 64-73)