Analysis of the fluctuations of the tumour/host interface

In a recent analysis of metabolic scaling in solid tumours we found a scaling law that interpolates between the power laws μ∝V and μ∝V2∕3, where μ is the metabolic rate expressed as the glucose absorption rate and V is the tumour volume. The scaling law fits quite well both in vitro and in vivo data, however we also observed marked fluctuations that are associated with the specific biological properties of individual tumours. Here we analyse these fluctuations, in an attempt to find the population-wide distribution of an important parameter (A) which expresses the total extent of the interface between the solid tumour and the non-cancerous environment. Heuristic considerations suggest that the values of the A parameter follow a lognormal distribution, and, allowing for the large uncertainties of the experimental data, our statistical analysis confirms this

Local and Nonlocal Continuum Limits of Ising-Type Energies for Spin Systems

We study, through a !-convergence procedure, the discrete to continuum limit of Ising-type energies of the form F"(u) = −Pi,j c" i,juiuj , where u is a spin variable defined on a portion of a cubic lattice "Zd 8 ⌦, ⌦ being a regular bounded open set, and valued in {−1, 1}. If the constants c" i,j are nonnegative and satisfy suitable coercivity and decay assumptions, we show that all possible !-limits of surface scalings of the functionals F" are finite on BV (⌦; {±1}) and of the formR Su'(x, ⌫u) dH11 d−1. If such decay assumptions are violated, we show that we may approximate nonlocal functionals of the form R Su '(⌫u) dHd−1+ K(x, y)g(u(x), u(y)) dxdy. We focus on the approximation of two relevant examples: fractional perimeters and Ohta–Kawasaki-type energies. Eventually, we provide a general criterion for a ferromagnetic behavior of the energies F" even when the constants c" i,j change sign. If such a criterion is satisfied, the ground states of F" are still the uniform states 1 and −1 and the continuum limit of the scaled energies is an integral surface energy of the form above

Pulsation-limited oxygen diffusion in the tumour microenvironment

Hypoxia is central to tumour evolution, growth, invasion and metastasis. Mathematical models of hypoxia based on reaction-diffusion equations provide seemingly incomplete descriptions as they fail to predict the measured oxygen concentrations in the tumour microenvironment. In an attempt to explain the discrepancies, we consider both the inhomogeneous distribution of oxygen-consuming cells in solid tumours and the dynamics of blood flow in the tumour microcirculation. We find that the low-frequency oscillations play an important role in the establishment of tumour hypoxia. The oscillations interact with consumption to inhibit oxygen diffusion in the microenvironment. This suggests that alpha-blockers\u2013a class of drugs used to treat hypertension and stress disorders, and known to lower or even abolish low-frequency oscillations of arterial blood flow \u2013may act as adjuvant drugs in the radiotherapy of solid tumours by enhancing the oxygen effect

Xenopus paraxis homologue shows novel domains of expression

The paraxis gene encodes a basic helix-loop-helix transcription factor that is expressed in paraxial mesoderm and whose mutant displays an inability to form epithelial somites. Here, the molecular characterization of Xenopus paraxis is reported. paraxis is expressed in the paraxial mesoderm and somites but is down-regulated during muscle differentiation. In addition to its paraxial mesodermal expression, described in other organisms, two novel expression domains of paraxis were found: the neural tube and the head mesoderm, paraxis expression in the neural tube was compared with the expression of the neural markers Xash and Xiro1, and we concluded that paraxis is expressed in a broad band in the prospective sulcus limitans of the neural tube.Fil: Carpio, Ronald. Universidad de Chile; ChileFil: Honore, Stella Maris. Universidad de Chile; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Araya, Claudio. Universidad de Chile; ChileFil: Mayor, Roberto. Colegio Universitario de Londres; Reino Unido. Universidad de Chile; Chil

A Modified Iterative Closest Point Algorithm for 3D Point Cloud Registration

In this article, an accurate method for the registration of point clouds returned by a 3D rangefinder is presented. The method modifies the well-known iterative closest point (ICP) algorithm by introducing the concept of deletion mask. This term is defined starting from virtual scans of the reconstructed surfaces and using inconsistencies between measurements. In this way, spatial regions of implicit ambiguities, due to edge effects or systematical errors of the rangefinder, are automatically found. Several experiments are performed to compare the proposed method with three ICP variants. Results prove the capability of deletion masks to aid the point cloud registration, lowering the errors of the other ICP variants, regardless the presence of artifacts caused by small changes of the sensor view-point and changes of the environment

Changes in personality factors, locus of control and creativity after a Theater-therapy intervention. Preliminary data

OBJECTIVE: The study assessed whether Theater-therapy based on Grotowski's method can improve creativity, internal locus of control and personality by promoting personal wellbeing. This study investigates the effects of Theater-therapy on: 1) personality, according to the Big five Theory; 2) internal locus of control; 3) verbal and figural creativity. DESIGN: Eight adults took part in a 6-month intervention based on Theater-therapy and were administered the following tests at the beginning and at the end of the activity: Big five questionnaire, Locus of control scale, Torrance test of creative thinking. RESULTS: The results showed an increase in all personality factors of Big Five, a more internal Locus of control, and an increase in creativity in the dimensions of fluidity, elaboration, originality and flexibility. CONCLUSION: Our study suggests that Theater-therapy can be regarded as a tool promoting well-bein

Analysis of the knowledge and satisfaction with applied behavior analysis as treatment for autism spectrum disorder in parents with affected, with healthy children and childless adults

OBJECTIVE: Applied Behavior Analysis (ABA) is an evidence-based approach for the treatment of Autism Spectrum Disorder (ASD). Erroneous beliefs deriving from a reductive conception of ABA partly explain the delay in the spread of ABA treatments in Italy. Nevertheless, an increasing number of parents have been choosing this treatment. The purpose of this survey is to investigate beliefs about ABA, the degree of satisfaction regarding ABA treatments, and the sources of information used to choose the treatment. DESIGN: The sample included 109 Italian participants: 67 parents of children with ASD, 19 parents of healthy children and 23 adults without children. Participants have been invited to complete an online questionnaire. Socio-demographic data was also collected, along with information on the sources consulted to choose a treatment and on the satisfaction for ABA treatments. RESULTS: Participants agree that ABA is an approach of choice that intervenes on socially significant skills, while they do not agree with several reductive and stereotypical statements related to it. Regarding the sources, most parents with children with ASD choose the consultation with other parents who live or have lived the same experience. Finally, although the majority of participants rate ABA treatments positively, findings proved that parents of children with ASD appreciate ABA treatments more than the other two groups. CONCLUSION: There is a broad agreement among participants in correctly identifying the distinctive features of ABA. This data indicates a certain diffusion of correct knowledge and a lower adherence to reductive concepts. The direct experience of applying ABA treatments emerges as an important variable for their positive evaluation. Even though treatment information is more accessible compared to the past, the tendency to seek advice from other parents of children with ASD remains. The results of the survey enable us to give concrete indications for training and dissemination activities

Collective radioresistance of T47D breast carcinoma cells is mediated by a Syncytin-1 homologous protein

It is generally accepted that radiotherapy must target clonogenic cells, i.e., those cells in a tumour that have self-renewing potential. Focussing on isolated clonogenic cells, however, may lead to an underestimate or even to an outright neglect of the importance of biological mechanisms that regulate tumour cell sensitivity to radiation. We develop a new statistical and experimental approach to quantify the effects of radiation on cell populations as a whole. In our experiments, we change the proximity relationships of the cells by culturing them in wells with different shapes, and we find that the radiosensitivity of T47D human breast carcinoma cells in tight clusters is different from that of isolated cells. Molecular analyses show that T47D cells express a Syncytin-1 homologous protein (SyHP). We observe that SyHP translocates to the external surface of the plasma membrane of cells killed by radiation treatment. The data support the fundamental role of SyHP in the formation of intercellular cytoplasmic bridges and in the enhanced radioresistance of surviving cells. We conclude that complex and unexpected biological mechanisms of tumour radioresistance take place at the cell population level. These mechanisms may significantly bias our estimates of the radiosensitivity of breast carcinomas in vivo and thereby affect treatment plans, and they call for further investigations