bluuebunny/crossref_metadata_2025 huggingface dataset:
On the use of high dose rate and sources with the MammoSite® radiation therapy system
Authors: Papagiannis P. , Karaiskos P. , Georgiou E. , Baltas D. , Lymperopoulou G. , Pantelis E. , Sakelliou L.
Published: September 2007

Ample literature exists on the dose overestimation by commercially available treatment planning systems in MammoSite® applications using high dose rate sources for partial breast brachytherapy as monotherapy, due to their inability to predict the dose reduction caused by the radiographic contrast solution in the balloon catheter. In this work Monte Carlo simulation is used to verify the dose rate reduction in a balloon breast applicator which does not vary significantly with distance and it is 1.2% at the prescription distance for the reference simulated geometry of 10% diluted radiographic contrast media and balloon radius. Based on these findings and the minimal hardening of the initially emitted photon spectrum for , a simple analytical method is proposed and shown capable for correcting dosimetry planning in clinical applications. Simulations are also performed to assess the corresponding dose reduction in applications of balloon breast applicators using high dose rate sources that have recently become available. Results yield a far more significant and distance dependent dose reduction for (on the order of 20% at the prescription distance for the abovementioned reference simulation geometry). This dose reduction cannot be accounted for using simple analytical methods as for due to the significant hardening of the initially emitted photons within the diluted radiographic contrast media. Combined with results of previous works regarding the effect of altered scatter conditions (relative to treatment planning system assumptions) on breast treatment planning accuracy, which is more pronounced for relative to , these findings call for the amendment of dose treatment planning systems before using high dose rate sources in balloon breast applicators.
Application of boundary detection information in breast tomosynthesis reconstruction
Authors: Zhang Yiheng , Chan Heang‐Ping , Sahiner Berkman , Wu Yi‐Ta , Zhou Chuan , Ge Jun , Wei Jun , Hadjiiski Lubomir M.
Published: September 2007

Digital tomosynthesis mammography (DTM) is one of the most promising techniques that can potentially improve early detection of breast cancers. DTM can provide three‐dimensional (3D) structural information by reconstructing the whole imaged volume from a sequence of projection‐view (PV) mammograms that are acquired at a small number of projection angles over a limited angular range. Our previous study showed that simultaneous algebraic reconstruction technique (SART) can produce satisfactory tomosynthesized image quality compared to maximum likelihood‐type algorithms. To improve the efficiency of DTM reconstruction and address the problem of boundary artifacts, we have developed methods to incorporate both two‐dimensional (2D) and 3D breast boundary information within the SART reconstruction algorithm in this study. A second generation GE prototype tomosynthesis mammography system with a stationary digital detector was used for PV image acquisition from 21 angles in 3° increments over a angular range. The 2D breast boundary curves on all PV images were obtained by automated segmentation and were used to restrict the SART reconstruction to be performed only within the breast volume. The computation time of SART reconstruction was reduced by 76.3% and 69.9% for cranio‐caudal and mediolateral oblique views, respectively, for the chosen example. In addition, a 3D conical trimming method was developed in which the 2D breast boundary curves from all PVs were back projected to generate the 3D breast surface. This 3D surface was then used to eliminate the multiple breast shadows outside the breast volume due to reconstruction by setting these voxels to a constant background value. Our study demonstrates that, by using the 2D and 3D breast boundary information, all breast boundary and most detector boundary artifacts can be effectively removed on all tomosynthesized slices.
A dosimetric calibration method for a double‐focused multileaf collimator
Authors: Lopes M. C. , Chaves A. , Capela M.
Published: September 2007

A method based on penumbra measurements and not on light field, is proposed for the calibration of the Siemens 82‐leaf Optifocus multileaf collimator (MLC). The measurements were performed using MLCSoft version 1.2.0.4. (PTW‐Freiburg, Germany), which is a software tool based on the LA48 measuring system (a linear array of 47 liquid‐ionization chambers). The new leaf positions for each of the leaf banks are calculated from the MLCSoft results using an external spreadsheet. Using the proposed method the MLC calibration is directly performed in terms of dosimetry settings with improved precision. The nominal resulting accuracy of is highly imposed by the limitations of the moving mechanism of the leaves and not by the method itself. To test the results of the MLC calibration, in‐water measurements of off‐axis dose profiles have been measured in order to verify different field sizes.
Comparative study of treatment dose plans after the refinement of Leksell Gamma Knife® single‐beam dose profiles
Authors: Cheung Joel Y. C. , Ng K. P. , Yu C. P. , Ho Robert T. K.
Published: September 2007

We investigated the amplification of discrepancy when using multiple shots of the same collimator size helmet, by comparing dose plans in the Leksell GammaPlan® employing the default single‐beam dose profiles and the Monte Carlo generated single‐beam profiles. Four collimator helmets were studied. The results show that the largest amplification of discrepancy with multiple shots was found with the 8 mm collimator because of the largest discrepancy of its single‐beam dose profile. The amplification of discrepancy is significant when tumor volumes increase but insignificant when the tumor volumes are in an elongated shape. Using close shot overlapping strategy (i.e., more shots close packed together) shows no observable increase in the amplification of discrepancy. For the best quality of Leksell Gamma Knife® radiosurgery, it is suggested that the single‐beam dose profiles should be refined, especially the 8 mm collimator, to prevent error amplification when using multiple collimator shots.
Sensitivity of NTCP parameter values against a change of dose calculation algorithm
Authors: Brink Carsten , Berg Martin , Nielsen Morten
Published: September 2007

Optimization of radiation treatment planning requires estimations of the normal tissue complication probability (NTCP). A number of models exist that estimate NTCP from a calculated dose distribution. Since different dose calculation algorithms use different approximations the dose distributions predicted for a given treatment will in general depend on the algorithm. The purpose of this work is to test whether the optimal NTCP parameter values change significantly when the dose calculation algorithm is changed. The treatment plans for 17 breast cancer patients have retrospectively been recalculated with a collapsed cone algorithm (CC) to compare the NTCP estimates for radiation pneumonitis with those obtained from the clinically used pencil beam algorithm (PB). For the PB calculations the NTCP parameters were taken from previously published values for three different models. For the CC calculations the parameters were fitted to give the same NTCP as for the PB calculations. This paper demonstrates that significant shifts of the NTCP parameter values are observed for three models, comparable in magnitude to the uncertainties of the published parameter values. Thus, it is important to quote the applied dose calculation algorithm when reporting estimates of NTCP parameters in order to ensure correct use of the models.
Leaf transmission reduction using moving jaws for dynamic MLC IMRT
Authors: Schmidhalter D. , Fix M. K. , Niederer P. , Mini R. , Manser P.
Published: September 2007

The aim of this work is to investigate to what extent it is possible to use the secondary collimator jaws to reduce the transmitted radiation through the multileaf collimator (MLC) during an intensity modulated radiation therapy (IMRT). A method is developed and introduced where the jaws follow the open window of the MLC dynamically (dJAW method). With the aid of three academic cases (Closed MLC, Sliding‐gap, and Chair) and two clinical cases (prostate and head and neck) the feasibility of the dJAW method and the influence of this method on the applied dose distributions are investigated. For this purpose the treatment planning system Eclipse and the Research‐Toolbox were used as well as measurements within a solid water phantom were performed. The transmitted radiation through the closed MLC leads to an inhomogeneous dose distribution. In this case, the measured dose within a plane perpendicular to the central axis differs up to 40% (referring to the maximum dose within this plane) for 6 and . The calculated dose with Eclipse is clearly more homogeneous. For the Sliding‐gap case this difference is still up to 9%. Among other things, these differences depend on the depth of the measurement within the solid water phantom and on the application method. In the Chair case, the dose in regions where no dose is desired is locally reduced by up to 50% using the dJAW method instead of the conventional method. The dose inside the chair‐shaped region decreased up to 4% if the same number of monitor units (MU) as for the conventional method was applied. The undesired dose in the volume body minus the planning target volume in the clinical cases prostate and head and neck decreased up to 1.8% and 1.5%, while the number of the applied MU increased up to 3.1% and 2.8%, respectively. The new dJAW method has the potential to enhance the optimization of the conventional IMRT to a further step.
MICROFUNGI: X. OEDEMIUM, DIMERA, DIPLOSPORIUM, GONGYLOCLADIUM, AND CLADOTRICHUM
Authors: Hughes S. J. , Hennebert G. L.
Published: September 2007

The genus Oedemium Link (syn. Diplosporium Link, Dimera Fries, Gongylocladium Wallr., Cladotrichum Corda) is revised. Two species are included, O. didymum (Schmidt) Hughes (syn. Botrytis didyma Schm., Oedemium atrum Link, Cladotrichum polysporum Corda, C. scyphophorum Corda, C. uniseptatum Cooke), and O. minus (Link) Hughes (syn. Helmisporium minus Link, Cladotrichum triseptatum Berk, and Br.). Both species are illustrated and described. An historical account of the relevant species and generic names is given and particular attention is paid to the misapplications of the names Oedemium and Diplosporium.
FORMATION OF SUGARS FROM PHENYLPROPANOID COMPOUNDS IN TOBACCO LEAF DISKS
Authors: Runeckles Victor C.
Published: September 2007

Leaf disks of Nicoliana tabacum var. Delcrest synthesize sugars from phenylpropanoid substrates. Appreciable incorporation of radioactivity into glucose, fructose, and sucrose occurs when C14-labelled L-phenylalanine, L-tyrosine, and cinnamic, p-coumaric, caffeic, and ferulic acids are supplied for 40 hours. In each case, incorporation in the light exceeds that in darkness. When L-phenylalanine or L-tyrosine are supplied, free glucose becomes labelled more rapidly than fructose or sucrose. Unlike the other substrates, L-tyrosine is not utilized in polyphenol metabolism. In terms of sugar production, however, comparable incorporation of activity occurs from each substrate.
THE BIOELECTRIC POTENTIALS OF PLANTS AND THEIR FUNCTIONAL SIGNIFICANCE: V. SOME DAILY AND SEASONAL CHANGES IN THE ELECTRICAL POTENTIAL AND RESISTANCE OF LIVING TREES
Authors: Fensom D. S.
Published: September 2007

Continuous records of bioelectric stem potentials have been made throughout a season for three kinds of tree: Ulmus americana L., Pinus resinosa Ait., and Acer saccharum Marsh. Daily measurements of potential and resistance for a 15-month period have also been made on a maple and some direct measurements of current are also given. A yearly rhythm was clearly visible, also daily cycles, and during the growing season cycles of 5-minute frequency. The yearly and daily rhythms have been interpreted in terms of electro-osmosis or streaming potential and seem to be correlated with the transport within the tree. The 5-minute oscillations have been related to cambial growth.
SYNTHESIS OF HETEROKARYONS IN RHIZOCTONIA SOLANI KÜHN
Authors: Whitney H. S. , Parmeter Jr. J. R.
Published: September 2007

The single-spore progeny of an isolate of Rhizoctonia solani showed a wide range of cultural types. When these progeny were paired by plating on opposite sides of Petri plates or by mixing semiliquid cultures, certain combinations gave rise to heterokaryons. The heterokaryons originated from hyphal anastomoses and were culturally distinct from either of the contributing homokaryons. Observations suggested a bipolar coaipatibility mechanism among the homokaryons. Some homokaryotic strains fruited, yielding culturally indistinguishable progeny. These homothallic lines also formed heterokaryons with other homothallic lines. The progeny of these heterokaryons showed a wide range of cultural types, indicating that some homokaryons could fruit either homothallically or heterothallically.
ORDINARY SQUEEZING AND AMPLITUDE-SQUARED SQUEEZING OF A SINGLE MODE COHERENT RADIATION IN INTERACTION WITH TWO TWO-LEVEL ATOMS
Authors: PRAKASH HARI , KUMAR RAKESH
Published: September 2007

In the present paper, we consider the interaction of a single mode radiation initially in a coherent state with an assembly of two two-level atoms in some different states using the Hamiltonian, H = ω(a+a + Sz)+g(a S+ + a+ S-) in the natural units, where a+ and a are the creation and annihilation operators for radiation, Sz, S± are the collective Dicke operators, g is the coupling constant, ω is the energy of the photons and energy difference between the two atomic levels. We solve it exactly. We study ordinary squeezing and amplitude-squared squeezing of radiation for the general operators, [Formula: see text] and Yθ=1/2(a2e-iθ+a+2eiθ), when atoms are fully excited, super-radiant or in the ground state. We get a large ordinary squeezing (nearly 88% squeezing) for the super-radiant atomic state, at a time, which is 0.451 of the first revival time, and this should be easily observable. We also get a large amplitude-squared squeezing (nearly 20%) at the time, which is about 0.033 of the first revival time. Variation of variances near their minima with coupling time gt, square root of mean photon number |α| and phase are also discussed.
NONCHAOTIC AND CHAOTIC BEHAVIOR IN THREE-DIMENSIONAL QUADRATIC SYSTEMS: FIVE-ONE CONSERVATIVE CASES
Authors: HEIDEL JACK , ZHANG FU
Published: September 2007

In this paper we study the nonchaotic and chaotic behavior of all 3D conservative quadratic ODE systems with five terms on the right-hand side and one nonlinear term (5-1 systems). We prove a theorem which provides sufficient conditions for solutions in 3D autonomous systems being nonchaotic. We show that all but five of these systems: (15a, 15b), (18b), (41)(A = ∓1), (43b), and (49a, 49b) are nonchaotic. Numerical simulations show that only one of the five systems, (43b), really appears to be chaotic. If proved to be true, it will be the simplest ODE system having chaos.
THE WEARABLE SENSOR DEVICES FOR DETECTING CONVERSATIONAL EXPERIENCES
Authors: ITO SADANORI , IWASAWA SHOICHIRO , SUMI YASUYUKI , MASE KENJI
Published: September 2007

We have developed a wearable device that records the activities of human–human and human–artifact interactions. Using microphones and cameras, the device imitates human perception, recording personal and social everyday-life experiences in multiple modalities, such as voice and visible scenes. These sensors record the perceived experiences continuously, and detect and index interactions from nonverbal behavior. The indexed stored experiences can serve as the first step toward a multimodal knowledge base created from daily life. An infrared LED ID tag system detects interactions, in terms of the ID and the relative positions of objects within the camera's visual field. In this study, we propose an "interaction scope" which is defined as the range of relative human–object positions that have a high probability of occurring in conversational interactions. Analysis of experimental conversational sessions confirms that this interaction scope exists and can represent these interactions naturally. We also demonstrate that our tag system effectively detects and measures the proposed interaction scope.
INFORMAL COMMUNICATION SUPPORT MEDIA FOR ENCOURAGING KNOWLEDGE-SHARING AND CREATION IN A COMMUNITY
Authors: NISHIMOTO KAZUSHI , MATSUDA KAN
Published: September 2007

In this paper, we propose a new approach to support information-sharing and activation of human networks in an organization. In this approach, someone who wants to know about something displays "what I want to know" on a large screen in a public space to let other people see it. This allows other people near the display to find out what he/she is interested in. If a person who knows about that sees the display by chance, they can talk about it on the spot in a face-to-face manner. Thus, smooth information-sharing can be achieved through spontaneous informal communications, and "know-who" knowledge is gradually accumulated. Based on experiments using a prototype system, we confirmed that this approach is effective for information-sharing and activating human networks.
HYPERLINKED COMIC STRIPS FOR SHARING PERSONAL CONTEXTS
Authors: SAKAMOTO RYUUKI , SUMI YASUYUKI , KOGURE KIYOSHI
Published: September 2007

Comic strips can be used as a style of visualization on a human–computer interface because they can represent a wide variety of affairs with contexts or time series. This paper describes two systems for sharing personal context as comic strips: ComicDiary and Comic-FOAF-Viewer. Both the systems depict personal experiences or profiles including personal relationships in their comic strips and hyperlinks among related comics based on other characters in the story. ComicDiary allegorizes individual episodes that happen during touring exhibitions by creating a comic from a user's touring records accumulated from personal guidance systems and environmental facts, e.g., social events. For example, a ComicDiary might show a user's personal diary during a Japanese academic conference. The comic describes where the conference was held, the most interesting presentations, what happened, and so on. Exhibitions are places visited by people of all generations. Comic representation of a personal diary with amiable expressions fits such places. The comic strip is automatically generated, composed of 12 frames, and shown as a diary. Users can view their diaries at information kiosks located at exhibition sites. Friend of a Friend (FOAF), which is an XML/RDF application for expressing personal information and relationships, has attracted attention from Web developers because its files can describe human-centered networks such as Social Network Service (SNS). Current FOAF visualization tools utilize graphs or tables; however, it is difficult to represent a variety of relations. Comic-FOAF-Viewer aims to represent the multifarious relations and personal information that FOAF has to offer for surfing interfaces in FOAF networks.
CONSENSUS-MAKING SUPPORT SYSTEMS DEDICATED TO CREATIVE PROBLEM SOLVING
Authors: KUNIFUJI SUSUMU , KATO NAOTAKA
Published: September 2007

There are many creative thinking manual methods in the world. They are brainstorming method, brain-writing method, mind mapping, NM method, Equivalent Transformation method, KJ method, etc. Human thinking process for creative problem solving consists of four sub-processes. They are divergent thinking sub-process, convergent thinking sub-process, idea crystallization sub-process, and idea verification sub-process. In accordance with this proposal, most Japanese research and development is centered on this four types of creative thinking manual methods and support systems. In this paper, we describe three types of Group Decision Support Systems (DSSs) for creative problem solving, similar to KJ method. All design philosophy depends on bottom-up decision-making. They are knowledge acquisition support groupware GRAPE, consensus-making support systems Group Coordinator (I) and Group Coordinator (II). The characteristic function of GRAPE is knowledge merging for GRAPE users, and that of Group-Coordinator (I) and Group-Coordinator (II) is tradeoff resolution by sensitivity analysis and adjusting of user requirements by the QDA method, respectively. The systems that we have developed are similar to the KJ method, which is the most popular methodology for creative problem solving in Japan. The essence of our developed methodology and tools is that it boosts intellectual productivity. GRAPE and its successors can speed-up the given group decision making problem by two to three times with respect to the idea crystallization (evaluation and judgment) sub-process.
EVALUATION AND APPLICATION OF CREATIVITY COLLABORATION SUPPORT SYSTEM GUNGEN DX II FOR CONSENSUS-BUILDING AMONG USERS
Authors: SHIGENOBU TOMOHIRO , YOSHINO TAKASHI , MUNEMORI JUN
Published: September 2007

We have developed a creativity collaboration support system, called GUNGEN, which supports the KJ method. The KJ method is one of the popular idea generation methods in Japan, like brainstorming. This method consists of four steps: entering ideas, grouping ideas, structuring groups, and writing composition. We have used about one hundred idea labels in the experiments. Several hundred labels are optimal to improve the results of the KJ method. However, long time is necessary to group more labels. Therefore, we have developed GUNGEN DX II for several hundred labels. GUNGEN DX II has a special function to group labels easily and efficiently. The feature for grouping labels is to restrict time and to operate easily. The function generates islands from the common parts of each user's groups automatically by majority decision. We have carried out the KJ method and compared it with the previous system. Even if the number of labels increased, the time required to group labels decreased by about 30%.
FIRST-PRINCIPLES STUDY OF ADSORPTION OF CN ON Cu(111)
Authors: LAI WENZHEN , RAN HONG , XIE DAIQIAN
Published: September 2007

The adsorption of CN on Cu (111) has been investigated using density functional theory calculations based on plane-wave expansion and pseudo-potential treatment. Calculations within the generalized gradient approximation predicted a preference for CN in the fcc C -down site. No stationary points corresponding to pure parallel mode were found. But the tilted mode was found to be achievable. The calculated vibrational frequencies of CN were used to correctly discriminate between the adsorption sites.
DETERMINATION OF THE ELECTRONIC GROUND STATE OF MOLECULAR SYSTEMS WITH THE MULTI-CONFIGURATION TIME-DEPENDENT HARTREE–FOCK METHOD
Authors: NEST M.
Published: September 2007

In this paper, we present progress in the application of the explicitly time-dependent multi-configuration time-dependent Hartree–Fock (MCTDHF) method. The spin–orbitals and equations of motion are expressed in the basis of Gaussian Type Orbitals. MCTDHF is then applied to the calculation of the electronic ground state of various small molecules by imaginary time propagation. We were able to take between four and 12 active electrons into account. We discuss the suitability of a core guess as initial wave function, the possibility to obtain excited states, as well as the consequences of a neglect of core excitations.
WATER CLUSTER HYDRATION OF EXCESS ELECTRONS TRAPPED IN CHARGE POCKETS ON MOLECULAR SURFACES
Authors: JALBOUT A. F. , DEL CASTILLO R.
Published: September 2007

In this paper, we explore the possibility of a small water cluster composed of three water molecules in forming stable dipole-bound anions with molecular surfaces. Our recent results show that charge pockets on surfaces can form by which OH groups situated on one side of the surface (that create hydrogen bonded networks) coupled to the hydrogen atoms on the opposite side of a surface can form positive charge pockets that attracts negative charge. These charge pockets from the molecular surfaces can align with the dipole moment generated by the small ( H 2 O )3 cluster to increase the stability of the resulting dipole-bound anion.
COMPUTER SIMULATIONS TO INVESTIGATE STABILITY AND STRUCTURAL PROPERTIES OF PEPTIDE AMPHIPHILE NANOFIBERS
Authors: CHEN RUO-YU , WU LING-YING , LIAO JUN-MIN , CHEN CHENG-LUNG
Published: September 2007

Molecular mechanics (MM) method followed by molecular dynamics (MD) simulation was carried out to investigate the stability of an aggregate formed by self-assembling of peptide amphiphile (PA) molecules. The MM + MD simulation confirms that the cylindrical shaped aggregate is very stable. The analysis showed that the remarkable stability of the aggregate was partly due to various intermolecular hydrogen-bond interactions between polar groups of PA molecules. The hydrophobic alkyl tails of PA molecules are packed loosely inside the interior of the aggregates. The packing of alkyl tails contribute further stability of the PA aggregate. Our simulations reproduce qualitatively experimental observations and support the fact that PA molecules are self-assembled within closed intermolecular distance to favor the forming of disulfide bonds.
COMPUTATIONAL CHARACTERIZATION OF MUTATIONS IN CARDIAC TROPONIN T KNOWN TO CAUSE FAMILIAL HYPERTROPHIC CARDIOMYOPATHY
Authors: GUINTO PIA J. , MANNING EDWARD P. , SCHWARTZ STEVEN D. , TARDIFF JIL C.
Published: September 2007

Cardiac Troponin T (cTnT) is a central modulator of thin filament regulation of myofilament activation. The lack of structural data for the TNT1 tail domain, a proposed α-helical region, makes the functional implications of the FHC mutations difficult to determine. Studies have suggested that flexibility of TNT1 is important in normal protein–protein interactions within the thin filament. Our groups have previously shown through molecular dynamics (MD) simulations that some FHC mutations, Arg92Leu (R92L) and Arg92Trp (R92W), result in increased flexibility at a critical hinge region 18 Angstroms distant from the mutation. To explain this distant effect and its implications for FHC mutations, we characterized the dynamics of wild type and mutational segments of cTnT using MD. Our data shows an opening of the helix between residues 105–110 in mutants. Consequently, the dihedral angles of these residues correspond to non-α-helical regions on Ramachandran plots. We hypothesize the removal of a charged residue decreases electrostatic repulsion between the point mutation and the surrounding residues resulting in local helical compaction. Constrained ends of the helix and localized compaction result in expansion within the nearest non-charged helical turn from the mutation site, residues 105–109.
REVERSED WAVELET FUNCTIONS AND SUBSPACES
Authors: LEVAN NHAN , KUBRUSLY CARLOS S.
Published: September 2007

Let the operators D and T be the dilation-by-2 and translation-by-1 on [Formula: see text], which are both bilateral shifts of infinite multiplicity. If ψ(·) in [Formula: see text] is a wavelet, then {DmTnψ(·)}(m,n)∈ℤ2is an orthonormal basis for the Hilbert space [Formula: see text] but the reversed set {TnDmψ(·)}(n,m)∈ℤ2is not. In this paper we investigate the role of the reversed functions TnDmψ(·) in wavelet theory. As a consequence, we exhibit an orthogonal decomposition of [Formula: see text] into T-reducing subspaces upon which part of the bilateral shift T consists of a countably infinite direct sum of bilateral shifts of multiplicity one, which mirrors a well-known decomposition of the bilateral shift D.
MULTIRESOLUTION ANALYSIS FOR SEPARATING CLOSELY SPACED FREQUENCIES WITH AN APPLICATION TO INDIAN MONSOON RAINFALL DATA
Authors: AZAD SARITA , NARASIMHA R. , SETT S. K.
Published: September 2007

In this paper we make use of the multiresolution properties of discrete wavelets, including their ability to remove interference, to reveal closely spaced spectral peaks. We propose a procedure which we first verify on two test signals, and then apply it to the time series of homogeneous Indian monsoon rainfall annual data. We show that, compared to empirical mode decomposition, discrete wavelet analysis is more effective in identifying closely spaced frequencies if used in combination with classical power spectral analysis of wavelet-based partially reconstructed time series. An effective criterion based on better localization of specific frequency components and accurate estimation of their amplitudes is used to select an appropriate wavelet. It is shown here that the discrete Meyer wavelet has the best frequency properties among the wavelet families considered (Haar, Daubechies, Coiflet and Symlet). In rainfall data, the present analysis reveals two additional spectral peaks besides the fifteen found by classical spectral analysis. Moreover, these two new peaks have been found to be statistically significant, although a detailed discussion of testing for significance is being presented elsewhere.
CHANNELED SAMPLING IN SHIFT INVARIANT SPACES
Authors: HONG Y. M. , KIM J. M. , KWON K. H. , LEE E. H.
Published: September 2007

We develop sampling expansion formulas on the shift invariant closed subspace V(ϕ) of L2ℝ generated by a frame or a Riesz generator ϕ(t). We find necessary and sufficient conditions under which a regular shifted sampling expansion to hold on V(ϕ) and also introduce a single channel sampling on V(ϕ) together with some illustrating examples.
A STATISTICAL APPROACH TO ROBUST VIDEO TEMPORAL INDEXING AND SEGMENTATION
Authors: KUMAR RAJEEV
Published: September 2007

For video indexing, the problem of video cut detection remains largely an open problem because of the wide nature of transitions that occur in a digital video. This paper describes a shot boundary detection technique, which is an amalgamation of few statistical methods and measures, and robustly detects camera breaks in a full-motion video clip. The proposed algorithm incorporates a weighted histogram, an error-propagation technique for increased robustness, and a curve-fitting technique to extract partitions from the similarity curve for avoiding heuristically chosen threshold value. The algorithm has been validated on many video clips and is shown to give improved results, including for videos with rapid scanning, changes in illumination, fade-ins and fade-outs, and with special effects like dissolve and filters.
Investigation of a landslip in the Fuller's Earth Clay, Lansdown, Bath
Authors: Cook D. A.
Published: September 2007

Rubbish dumping into an abandoned quarry in the Great Oolite on a south facing slope of Lansdown, Bath, has provoked a series of slides which now sterilises 12 acres of grazing land. The first major slide in October 1969 was followed by two further movements by January 1971. They account for a total downhill movement of 210 m. Where access to the site made investigation possible, a distinctive shear zone was exposed, sandwiched between the base of the fill and top of the weathered Fuller's Earth clays. Adjacent to the slip, the natural ground succession showed a mixed stony soft brown reworked clay (solifluction) layer, overlying interbedded clay mudstone bands of the Fuller's Earth series. Drained triaxial tests on the brown clay gave shear parameters of φ′ = 17·4°, c′ = 0; and an estimate of residual strength of φ = 12°. The former value would accord with a high (perched) water table on the adjacent slopes at 12·7°–8·7°. Whilst accurate back analysis is not presently possible, due to absence of specific measurements of the surface ground water levels, it is concluded that a limiting stability exists on the slope generally, irrespective of the fill dumping.
Methods for the rapid assessment of the stability of three-dimensional rock slopes
Authors: Hoek Evert
Published: September 2007

1. Introduction

T
he rock slope engineer
is faced with two types of design problem:

(a) General stability analyses which apply to the overall design of highway or opencast mine slopes and where the quality of the geological data available does not justify a detailed stability calculation.

(b) Particular stability analyses which are required for critical slopes identified by the general analysis or for slopes which act as foundations for arch dams, large buildings and similar projects in which a high financial investment is concentrated on a relatively small volume of rock.

These two types of design problem are linked in the flow chart presented in Fig. 1 which shows that any slope design study should proceed from a general to a particular form of analysis.

Details of the methods which may be used for the stability analysis of critical slopes (step 8 in Fig. 1) have been published by Hoek, Bray & Boyd (1973). The present paper will deal with the general methods of slope analysis which may be used for step 2 in Fig. 1.

2. Recognition of failure mechanism

Good rock slope engineering starts with good geological data collection and any attempt to carry out a stability analysis without first having defined the geology of the slope is a total waste of time. Rock slope failure is generally controlled by structural discontinuities such as faults, bedding planes and joints in the rock mass and hence the definition of these features is the most important part of the preliminary
The monitoring of rock slopes
Authors: Franklin J. A. , Denton P. E.
Published: September 2007

This paper reviews some principles of rock slope monitoring and describes equipment that can be used for this purpose. In attempting a broad review of techniques it is impossible to give full details relevant to each item of equipment, or to supplement the text with case histories. This information can be found in the bibliography, in the tables that supplement the text, or by consulting instrumentation companies such as those listed in Appendix I.
Four long-term failures of embankments founded on areas of landslip
Authors: Chandler R. J. , Pachakis M. , Mercer J. , Wrightman J.
Published: September 2007

Four case records are presented of road or railway embankment failures where the bank has been constructed over previously landslipped areas. These records draw attention to the possibility of long-term failure resulting from the existence of the landslip shear surfaces beneath the embankment, even when the bank has been successfully constructed without the development of short-term failures. Evidence is presented which shows that the delayed failure at least in part results from the swelling and consequent reduction of strength of the embankment fill following the development of a perched water table in the crest of the bank. However the final ‘trigger’ causing failure may be the result of exceptional groundwater conditions following heavy rain.
Physical Properties of Wolf-Rayet Stars
Authors: Crowther Paul A.
Published: September 2007

The striking broad emission line spectroscopic appearance of Wolf-Rayet (WR) stars has long defied analysis, owing to the extreme physical conditions within their line- and continuum-forming regions. Recently, model atmosphere studies have advanced sufficiently to enable the determination of stellar temperatures, luminosities, abundances, ionizing fluxes, and wind properties. The observed distributions of nitrogen- (WN) and carbon (WC)-sequence WR stars in the Milky Way and in nearby star-forming galaxies are discussed; these imply lower limits to progenitor masses of ∼25, 40, and 75 M⊙ for hydrogen-depleted (He-burning) WN, WC, and H-rich (H-burning) WN stars, respectively. WR stars in massive star binaries permit studies of wind-wind interactions and dust formation in WC systems. They also show that WR stars have typical masses of 10–25 M⊙, extending up to 80 M⊙ for H-rich WN stars. Theoretical and observational evidence that WR winds depend on metallicity is presented, with implications for evolutionary models, ionizing fluxes, and the role of WR stars within the context of core-collapse supernovae and long-duration gamma-ray bursts.
Overexpression of FLIPL Is an Independent Marker of Poor Prognosis in Colorectal Cancer Patients
Authors: Ullenhag Gustave J. , Mukherjee Abhik , Watson Nicholas F.S. , Al-Attar Ahmad H. , Scholefield John H. , Durrant Lindy G.
Published: September 2007

Purpose: Colorectal cancer is one of the most common cancers. The tumor necrosis factor–related apoptosis inducing ligand (TRAIL) pathway transmits apoptotic signals and anticancer agents that activate this system, which are in clinical development. We sought to determine the prognostic value of the clinically most relevant members of this pathway in colorectal cancer patients.

Experimental Design: We used an arrayed panel of colorectal cancer tissue to assess the protein expression of the functional TRAIL receptors (TRAIL-R1 and TRAIL-R2) and both the long and short forms of FLICE inhibitory protein (FLIPL and FLIPS). Disease-free survival was examined by Kaplan-Meier estimates and the log-rank test. Prognostic factors were determined by Cox multivariate analysis.

Results: The TRAIL receptors and FLIPS were not associated with survival. On univariate analysis, strong FLIPL expression was associated with a significantly higher survival (P = 0.0082). On multivariate analysis using the Cox proportional hazards model, FLIPL phenotype was significantly associated with a poor prognosis in this series (hazard ratio, 2.04; 95% confidence interval, 1.18-3.56; P = 0.011).

Conclusions: Overexpression of FLIPL, but not TRAIL-R1 or TRAIL-R2, provides stage-independent prognostic information in colorectal cancer patients. This may indicate a clinically more aggressive phenotype and a subset of patients for whom more extensive adjuvant treatment would be appropriate.
Association Between Hypermethylated Tumor and Paired Surgical Margins in Head and Neck Squamous Cell Carcinomas
Authors: Martone Tiziana , Gillio-Tos Anna , De Marco Laura , Fiano Valentina , Maule Milena , Cavalot Andrea , Garzaro Massimiliano , Merletti Franco , Cortesina Giorgio
Published: September 2007

Purpose: Surgical margin status is reported to be a relevant prognostic factor in head and neck squamous cell carcinoma (HNSCC), associated with a high risk of local recurrence. This study examines whether gene-promoter hypermethylation could be detected in HNSCC surgical margins with no histologic evidence of malignancy, and if so, whether it reflects epigenetic events of primary tumors.

Experimental Design: Promoter methylation status of MGMT, p16, and DAP-K genes was evaluated by methylation-specific PCR in 20 primary HNSCC tumors. Histopathologically negative surgical margins of hypermethylated tumors were collected, and their methylation status compared with the primary tumor status.

Results: Promoter hypermethylation in at least one of the three tested genes was detected in 65% (13 of 20) of tumors. MGMT was hypermethylated in 50% (10 of 20), DAP-K in 45% (9 of 20), and p16 in 20% (4 of 20) of tumors. Methylation status was analyzed in 35 margins from 11 of 13 patients showing promoter hypermethylation in the tumor tissue. Identical methylation events were seen for at least one gene in primary tumor and surgical margins in 9 of 11 cases (82%). Association was found for gene-specific hypermethylation status in tumors and paired surgical margins, and gene-specific concordance was 63% for MGMT (κ = 0.24), 90% for DAP-K (κ = 0.74), and 90% for p16 (κ = 0.79).

Conclusions: Our results support the hypothesis that detection of gene promoter hypermethylation in HNSCC tumor cells–free surgical margins may be a helpful biomarker to identify molecularly altered fields in areas adjacent to the tumor.
Methylation of Tumor-Related Genes in Neoadjuvant-Treated Gastric Cancer: Relation to Therapy Response and Clinicopathologic and Molecular Features
Authors: Napieralski Rudolf , Ott Katja , Kremer Markus , Becker Karen , Boulesteix Anne-Laure , Lordick Florian , Siewert Jörg Rüdiger , Höfler Heinz , Keller Gisela
Published: September 2007

Purpose: The objective of this study was to analyze the hypermethylation of tumor-related gene promoters for an association with therapy response and clinicopathologic features of neoadjuvant-treated gastric cancer patients. Furthermore, we analyzed the relationship of promoter hypermethylation with microsatellite instability and loss of heterozygosity (LOH) of the tumors.

Experimental Design: Pretherapeutic biopsies of 61 patients, subsequently treated with cisplatin and 5-fluorouracil, were studied. Methylation analysis of six gene promoters was done using MethyLight technology. Microsatellite analysis was mainly done in previous studies.

Results: The methylation frequencies for the analyzed genes were MGMT, 44%; LOX, 53%; p16, 46%, E-cadherin, 30%; 14-3-3σ, 69%; and HPP1, 82%. Concordant methylation of more than three genes was found in 46% of the tumors and was inversely correlated with the LOH rate (P = 9 × 10−5) and associated with female gender (P = 0.049), nonintestinal type tumors (P = 0.04), and a nonproximal tumor location (P = 0.003). No statistically significant association between the methylation of a single gene or the concordant methylation of multiple genes was found with response or survival. However, patients with none or only one methylated gene showed a trend for an increase in survival (5-year survival rate, 83% versus 35%; P = 0.067).

Conclusion: The highly significant inverse correlation of promoter methylation and LOH rate reflects major alternative molecular pathways in gastric carcinogenesis. Methylation was not statistically significantly associated with the response to cisplatin/5-fluorouracil–based therapy. However, a concordant methylation of more than three genes defines subgroups of gastric cancer with distinct biological and genetic characteristics.
Cyclooxygenase-2 and Platelet-Derived Growth Factor Receptors as Potential Targets in Treating Aggressive Fibromatosis
Authors: Signoroni Stefano , Frattini Milo , Negri Tiziana , Pastore Elisa , Tamborini Elena , Casieri Paola , Orsenigo Marta , Da Riva Luca , Radice Paolo , Sala Paola , Gronchi Alessandro , Bertario Lucio , Pierotti Marco A. , Pilotti Silvana
Published: September 2007

Purpose: To explore the molecular bases of potential new pharmacologic targets in aggressive fibromatosis (desmoid tumor).

Experimental Design: Tumor specimens from 14 patients surgically treated for aggressive fibromatosis (6 familial adenomatous polyposis and 8 sporadic cases), analyzed for adenomatous polyposis coli (APC) and CTNNB1 (β-catenin) mutations, were further investigated for β-catenin, cyclooxygenase-2 (COX-2), platelet-derived growth factor (PDGF) receptor α (PDGFRA)/PDGF receptor β (PDGFRB), their cognate ligands (PDGFA and PDGFB), and KIT using a comprehensive immunohistochemical, biochemical, molecular, and cytogenetic approach.

Results: No CTNNB1 (β-catenin) mutations were found in the familial adenomatous polyposis patients, but previously reported activating mutations were found in six of the eight sporadic patients. All of the cases carrying an altered WNT pathway showed nuclear and cytoplasmic immunoreactivity for β-catenin, whereas β-catenin expression was restricted to the cytoplasm in the sporadic patients lacking CTNNB1 mutations. COX-2 protein and mRNA overexpression was detected in all 14 cases, together with the expression and phosphorylation of PDGFRA and PDGFRB, which in turn paralleled the presence of their cognate ligands. No PDGFRB mutations were found. The results are consistent with PDGFRA and PDGFRB activation sustained by an autocrine/paracrine loop.

Conclusions: Aggressive fibromatosis is characterized by WNT/oncogene pathway alterations triggering COX-2–mediated constitutive coactivation of PDGFRA and PDGFRB, and may therefore benefit from combined nonsteroidal anti-inflammatory drug + tyrosine kinase inhibitor treatment.
Resveratrol Inhibits Tumor Growth of Human Neuroblastoma and Mediates Apoptosis by Directly Targeting Mitochondria
Authors: van Ginkel Paul R. , Sareen Dhruv , Subramanian Lalita , Walker Quintisha , Darjatmoko Soesiawati R. , Lindstrom Mary J. , Kulkarni Amol , Albert Daniel M. , Polans Arthur S.
Published: September 2007

Purpose: Neuroblastoma is an aggressive childhood disease of the sympathetic nervous system. Treatments are often ineffective and have serious side effects. Because resveratrol, a natural plant product, has been reported to have limited toxicity at chemotherapeutic levels, we investigated its efficacy in the treatment of neuroblastoma as well as its underlying mechanism of action.

Experimental Design: Resveratrol was tested in mouse xenograft models of human neuroblastoma and in vitro using human cell lines.

Results: Resveratrol inhibited the outgrowth of tumors by as much as 80%. The bioavailability of the drug in serum was in the low micromolar range (2-10 μmol/L) and no accumulation was observed in tumor tissue. When resveratrol levels were increased by peritumor injection, rapid tumor regression occurred. Resveratrol decreased tumor cell viability in vitro by 75% to 90%, resulting from an inhibition of cell proliferation and an induction of apoptosis. Loss of mitochondrial membrane potential was an early response to resveratrol. In addition, resveratrol treatment of isolated mitochondria also led to depolarization, suggesting that the drug may target mitochondria directly. Following depolarization, resveratrol caused the release of cytochrome c and Smac/Diablo from the mitochondria and subsequently the activation of caspase-9 (4- to 8-fold) and caspase-3 (4- to 6-fold).

Conclusions: These studies indicate that, despite low bioavailability, resveratrol is effective at inhibiting tumor growth. Elevated levels of resveratrol enhance its antitumor potency leading to tumor regression, associated with widespread tumor cell death, the underlying mechanism of which involves the direct activation of the mitochondrial intrinsic apoptotic pathway.
Targeting the Limitless Replicative Potential of Cancer: The Telomerase/Telomere Pathway
Authors: Kelland Lloyd
Published: September 2007

The maintenance of telomeric DNA underlies the ability of tumors to possess unlimited replicative potential, one of the hallmarks of cancer. Telomere length and structure are maintained by the reverse transcriptase telomerase and a multiprotein telomere complex termed shelterin. Telomerase activity is elevated in the vast majority of tumors, and telomeres are critically shortened in tumors versus normal tissues, thus providing a compelling rationale to target the telomerase/telomere pathway for broad-spectrum cancer therapy. This strategy is supported by a variety of genetic-based target validation studies. Both telomerase inhibitors and telomere interactive molecules have shown stand-alone antitumor activity at nontoxic doses against a variety of human tumor xenografts in mice. These translational advances have resulted in the first antitelomerase agent, the oligonucleotide-based GRN163L targeting the telomerase RNA template, entering clinical evaluation. Additional translational approaches, such as targeting telomeres using G-quadruplex ligands, should result in antitelomere agents, such as RHPS4, entering the clinic in the near future. These prototype trials will be extremely informative in determining the role of the telomerase/telomere pathway in clinical oncology and, moreover, whether drugs targeting the unlimited replicative potential of cancer will find a place in cancer chemotherapy.