A Classification Scheme for Phenomenological Universalities in Growth Problems

A classification in universality classes of broad categories of phenomenologies, belonging to different disciplines, may be very useful for a crossfertilization among them and for the purpose of pattern recognition. We present here a simple scheme for the classification of nonlinear growth problems. The success of the scheme in predicting and characterizing the well known Gompertz, West and logistic models suggests to us the study of a hitherto unexplored class of nonlinear growth problems.Comment: 4 pages,1 figur

Physical Aspects of Cancer Invasion

Invasiveness, one of the hallmarks of tumor progression, represents the tumor's ability to expand into the host tissue by means of several complex biochemical and biomechanical processes. Since certain aspects of the problem present a striking resemblance with well known physical mechanisms, such as the mechanical insertion of a solid inclusion in an elastic material specimen [1, 2] or a water drop impinging on a surface [3], we propose here an analogy between these physical processes and a cancer system's invasive branching into the surrounding tissue. Accounting for its solid and viscous properties, we present a unifying concept that the tumor behaves as a granular solid. While our model has been explicitly formulated for multicellular tumor spheroids in vitro, it should also contribute to a better understanding of tumor invasion in vivo.Comment: 20 pages, 2 figure

Ultrasonic Separation of Stress and Texture Effects in Polycrystalline Aggregates

Our general perturbation formalism1 for the propagation of Rayleigh waves on the surface of initially deformed anisotropic material plates is applied to the problem of separation of material texture and stress. The preferential alignment of crystallographic axes in a polycrystalline material is described in terms of their orientation distribution function2. We consider explicitly the case of an orthotropic distribution of cubic crystallites, which occurs, for example, in aluminum and steel alloys. The measured values of the Rayleigh wave phase velocity at different angles on the material plate can be used for the determination, in a reference plate with similar texture, of the three coefficients W400, W420 and W440, which characterize the orientation distribution. An extension of the formalism then allows us to separate the acoustoelastic effects of the initial stresses. An error analysis and a comparison with similar techniques using grazing SH-waves complete our discussion

A novel approach to the analysis of human growth

OBJECTIVES: Several formulations have been proposed in order to model human growth from birth to maturity. They are usually based on “ad hoc” heuristic assumptions. In the present contribution we adopt, as an alternative, a completely general (interdisciplinary) approach, based on the formalism of the Phenomenological Universalities (PUN). METHODS: The main PUN class investigated to date, i.e. UN, can only account for the overall growth pattern. For a realistic description it is necessary to add to it one or more “spurts”, as expected on biological grounds, due to the stimulation of growth and sex hormones. RESULTS: A new PUN class (UN + FM) is generated and shown to be able to provide excellent agreement with standard auxological datasets. The accuracy of the fitting and reliability of the model suggest applications both at the diagnostic and therapeutic level. CONCLUSIONS: The developed formalism can be suitably related to the biological description of bone plate growth under selective hormonal stimulation on the bone epiphysis; i.e., the additional increase of stature is the “macroscopic” response to a well defined biological signal

A Resource for Detecting Misspellings and Denoising Medical Text Data

In this paper we propose a method for collecting a dictionary to deal with noisy medical text documents. The quality of such Italian Emergency Room Reports is so poor that in most cases these can be hardly automatically elaborated; this also holds for other languages (e.g., English), with the notable difference that no Italian dictionary has been proposed to deal with this jargon. In this work we introduce and evaluate a resource designed to fill this gap.In questo lavoro illustriamo un metodo per la costruzione di un dizionario dedicato all’elaborazione di documenti medici, la porzione delle cartelle cliniche annotata nei reparti di pronto soccorso. Questo tipo di documenti è così rumoroso che in genere le cartelle cliniche difficilmente posono essere direttamente elaborate in maniera automatica. Pur essendo il problema di ripulire questo tipo di documenti un problema rilevante e diffuso, non esisteva un dizionario completo per trattare questo linguaggio settoriale. In questo lavoro proponiamo e valutiamo una risorsa finalizzata a condurre questo tipo di elaborazione sulle cartelle cliniche

Parallel processing technique for acoustic tomography for multilayers

Computerized tomography (CT) is one of the most efficient tools for the nondestructive inspection of a material specimen. Depending on the nature of the application (e.g. in medicine, mechanics or geophysics) and of the particular requirements of the situation, different types of radiation (waves) may be used, thus giving different information about the material properties. For example in diagnostic medicine, x-ray transmission CT gives an attenuation map, which allows different tissues to be distinguished. In the case of x-rays, this type of wave passes through an entire material structure in an almost straight line

A New Computational Tool for the Phenomenological Analysis of Multipassage Tumor Growth Curves

Multipassage experiments are performed by subcutaneous implantation in lab animals (usually mice) of a small number of cells from selected human lines. Tumor cells are then passaged from one mouse to another by harvesting them from a growing tumor and implanting them into other healthy animals. This procedure may be extremely useful to investigate the various mechanisms involved in the long term evolution of tumoral growth. It has been observed by several researchers that, contrary to what happens in in vitro experiments, there is a significant growth acceleration at each new passage. This result is explained by a new method of analysis, based on the Phenomenological Universalities approach. It is found that, by means of a simple rescaling of time, it is possible to collapse all the growth curves, corresponding to the successive passages, into a single curve, belonging to the Universality Class U2. Possible applications are proposed and the need of further experimental evidence is discussed

Photofission and Quasi-Deuteron-Nuclear State as Mixing of Bosons and Fermions

The empirical-phenomenological quasi-deuteron photofission description is theoretically justified within the semiclassical, intermediate statistics model. The transmutational fermion (nucleon) - boson (quasi-deuteron) potential plays an essential role in the present context and is expressed in terms of thermodynamical and of microscopical quantities, analogous to those commonly used in the superfluid nuclear model.Comment: 7 pages, RevTex, to appear in Zeit. f. Phys.

The Use of Ultrasonics for Texture Monitoring in Aluminum Alloys

Many alloys of common metals (such as aluminum and steel) are polycrystalline aggregates having preferred orientation (texture) of the single crystals making up the aggregate. Texture often affects mechanical properties, such as response of material to deep drawing which occurs in the manufacture of aluminum cans

Tracking tumor evolution via prostate-specific antigen: an individual post-operative study

<p>Abstract</p> <p>Background</p> <p>The progress of the prostate-specific antigen (PSA) level after radical prostatectomy is observed for a patient in order to extract information about the mode of tumor cell growth. Although PSA values are determined routinely to find the doubling time of the prostate marker, to our knowledge, this analysis is the first in the literature.</p> <p>Results</p> <p>The prostate tumor marker values were determined regularly after the surgery and plotted on a logarithmic scale against time. An initial rapid-growth mode changed to a slower power-law regime within two years of surgery. Our analysis associates this observation with a transition in the growth mode from unrestricted growth of dispersed cells to their clumping into macroscopic structures.</p> <p>Conclusions</p> <p>Such studies may help determine the appropriate time window for postoperative therapies in order to increase the life expectancy of the patient.</p