The Renormalization Group and Dynamical Triangulations

A block spin renormalization group approach is introduced which can be applied to dynamical triangulations in any dimension.Comment: Talk presented at LATTICE96(gravity

Sheet SK 00 SW and SK 00 SE ALDRIDGE - BROWNHILLS : part of 1:50 000 Sheet 154 (Lichfield)

This report embodies some of the results of a study commissioned by the Department of the Environment in 1983 to provide a geological information base, to enable informed consideration to be given to development proposals for the Aldridge - Brownhills area. It is mainly concerned with hydrogeology, subsidence and bulk minerals resources.There is a substantial introductory section on general geology, to give the geological context of these planning-related aspects

Is the mean-field approximation so bad? A simple generalization yelding realistic critical indices for 3D Ising-class systems

Modification of the renormalization-group approach, invoking Stratonovich transformation at each step, is proposed to describe phase transitions in 3D Ising-class systems. The proposed method is closely related to the mean-field approximation. The low-order scheme works well for a wide thermal range, is consistent with a scaling hypothesis and predicts very reasonable values of critical indices.Comment: 4 page

Nonperturbative Description of Deep Inelastic Structure Functions in Light-Front QCD

We explore the deep inelastic structure functions of hadrons nonperturbatively in an inverse power expansion of the light-front energy of the probe in the framework of light-front QCD. We arrive at the general expressions for various structure functions as the Fourier transform of matrix elements of different components of bilocal vector and axial vector currents on the light-front in a straightforward manner. The complexities of the structure functions are mainly carried by the multi-parton wave functions of the hadrons, while, the bilocal currents have a dynamically dependent yet simple structure on the light-front in this description. We also present a novel analysis of the power corrections based on light-front power counting which resolves some ambiguities of the conventional twist analysis in deep inelastic processes. Further, the factorization theorem and the scale evolution of the structure functions are presented in this formalism by using old-fashioned light-front time-ordered perturbation theory with multi-parton wave functions. Nonperturbative QCD dynamics underlying the structure functions can be explored in the same framework. Once the nonperturbative multi-parton wave functions are known from low-energy light-front QCD, a complete description of deep inelastic structure functions can be realized.Comment: Revtex, 30 pages and no figur

Impact of tumor size and tracer uptake heterogeneity in (18)F-FDG PET and CT non-small cell lung cancer tumor delineation.: 18F-FDG PET and CT tumor delineation in NSCLC

International audienceUNLABELLED: The objectives of this study were to investigate the relationship between CT- and (18)F-FDG PET-based tumor volumes in non-small cell lung cancer (NSCLC) and the impact of tumor size and uptake heterogeneity on various approaches to delineating uptake on PET images. METHODS: Twenty-five NSCLC cancer patients with (18)F-FDG PET/CT were considered. Seventeen underwent surgical resection of their tumor, and the maximum diameter was measured. Two observers manually delineated the tumors on the CT images and the tumor uptake on the corresponding PET images, using a fixed threshold at 50% of the maximum (T(50)), an adaptive threshold methodology, and the fuzzy locally adaptive Bayesian (FLAB) algorithm. Maximum diameters of the delineated volumes were compared with the histopathology reference when available. The volumes of the tumors were compared, and correlations between the anatomic volume and PET uptake heterogeneity and the differences between delineations were investigated. RESULTS: All maximum diameters measured on PET and CT images significantly correlated with the histopathology reference (r > 0.89, P < 0.0001). Significant differences were observed among the approaches: CT delineation resulted in large overestimation (+32% ± 37%), whereas all delineations on PET images resulted in underestimation (from -15% ± 17% for T(50) to -4% ± 8% for FLAB) except manual delineation (+8% ± 17%). Overall, CT volumes were significantly larger than PET volumes (55 ± 74 cm(3) for CT vs. from 18 ± 25 to 47 ± 76 cm(3) for PET). A significant correlation was found between anatomic tumor size and heterogeneity (larger lesions were more heterogeneous). Finally, the more heterogeneous the tumor uptake, the larger was the underestimation of PET volumes by threshold-based techniques. CONCLUSION: Volumes based on CT images were larger than those based on PET images. Tumor size and tracer uptake heterogeneity have an impact on threshold-based methods, which should not be used for the delineation of cases of large heterogeneous NSCLC, as these methods tend to largely underestimate the spatial extent of the functional tumor in such cases. For an accurate delineation of PET volumes in NSCLC, advanced image segmentation algorithms able to deal with tracer uptake heterogeneity should be preferred

Registration of GEMS-0001 Maize Germplasm Resistant to Leaf Blade, Leaf Sheath, and Collar Feeding by European Corn Borer

This article is from Crop Science 41 (2001): 1651–1652, doi:10.2135/cropsci2001.4151651x.</p

Digital Design Considerations for Volunteer Recruitment: Making the Implicit Promises of Volunteering More Explicit

Non-profit organisations may find it difficult to demonstrate to potential volunteers what is required in their voluntary role-resulting in a mismatch between expectations and reality for volunteers. This mismatch could be perceived as a psychological contract breach. We interviewed 18 volunteers and 7 coordinators about their experiences and expectations in order to understand how the experience of volunteers can better be captured and communicated. Further, we wished to consider how future digital platforms might capture important elements of the volunteer experience to better support recruitment, retention and recognition. We present our findings and discuss digital platform implications around the four implicit 'promises' of volunteering: the social promise, the opportunity promise, the value promise and the organisational citizenship promise. We add to literature exploring the voluntary sector by assessing the feasibility of digital interventions to support various aspects of volunteer and coordinator roles

Value of Grinding Grains and Roughages for Livestock

This experiment was conducted in cooperation with the departments of Agricultural Engineering, Animal Husbandry and Dairy Husbandry of South Dakota State College. The department of Agricultural Engineering ground the grains and roughages with a burr grinder. For power a tractor was used, such as is found on any farm where grinding is practiced. The departments of Animal Husbandry and Dairy Husbandry fed these ground grains and roughages to livestock of the different kinds. There has been for some time, and there is today a demand for information along these lines because some farmers who have purchased tractors to assist with the farm work are eager to utilize this machinery to the best advantage during the idle period. Naturally, the question of grinding all the roughages and grains grown on the farm before feeding to all kinds of livestock is suggested. This experiment did not include all of the grains and roughages but only some of those that are more commonly grown in the state. We know there are feeds that would be more palatable for some livestock if ground than unground. Palatability is an important factor in all feeding operations. The practice of mixing ground grains and roughages at the time of grinding has been advocated by some; because of this we fed the ground feeds mixed, as well as in separate troughs, to learn whether there was any great advantage in feeding in this manner. Therefore, this bulletin not only includes the advantages and disadvantages of feeding ground grains and ground roughages, as such, in separate troughs but the advantages and disadvantages of feeding the ground feeds mixed. There are more mixed feeds for sale at the present time than ever before. In some cases feeds are mixed while being ground, but in our mixing we aimed to mix the same quantity of each as animals were consuming when the ground feeds were fed in separate troughs. It required time to mix these feeds daily but in figuring the cost of producing 100 pounds of gain we have not included anything for this chore

Bedside theatre performance and its effects on hospitalised children's well-being

This article reports on practice-based pilot research being undertaken at Birmingham Children's Hospital in England on the impact of bedside theatre performance on hospitalised children's well-being. It discusses the process of creating theatre for sick children, connecting with the hospital and working within the hospital tight routines, dealing with ethics, working with theatre artists and performing to children bedside. It also reports on evidence collected by questionnaire and interviews about the perceived benefits of bedside theatre by children and their parent/carers. This emphasis on the process is appropriate for theatre practitioners, arts therapists and clinical staff who work with hospitalised children

Problems with the definition of renormalized Hamiltonians for momentum-space renormalization transformations

For classical lattice systems with finite (Ising) spins, we show that the implementation of momentum-space renormalization at the level of Hamiltonians runs into the same type of difficulties as found for real-space transformations: Renormalized Hamiltonians are ill-defined in certain regions of the phase diagram.Comment: 14 pages, late