A Human Gesture Mapping Method to Control a Multi‐Functional Hand for Robot‐Assisted Laparoscopic Surgery: The MUSHA Case

This work presents a novel technique to control multi-functional hand for robot-assisted laparoscopic surgery. We tested the technique using the MUSHA multi-functional hand, a robot-aided minimally invasive surgery tool with more degrees of freedom than the standard commercial end-effector of the da Vinci robot. Extra degrees of freedom require the development of a proper control strategy to guarantee high performance and avoid an increasing complexity of control consoles. However, developing reliable control algorithms while reducing the control side's mechanical complexity is still an open challenge. In the proposed solution, we present a control strategy that projects the human hand motions into the robot actuation space. The human hand motions are tracked by a LeapMotion camera and mapped into the actuation space of the virtualized end-effector. The effectiveness of the proposed method was evaluated in a twofold manner. Firstly, we verified the Lyapunov stability of the algorithm, then an user study with 10 subjects assessed the intuitiveness and usability of the system

2D Continuous Wavelet Transform of potential fields due to extended source distributions

AbstractWe analyse the real Continuous Wavelet Transform 2D (CWT2D) of potential fields for the investigation of potential field singularities. We focus our attention to extended geological sources, in order to verify the reliability of this method with realistic fields. 3D space-scale representation (3D Scalogram) related to synthetic models were generated, showing the Wavelet Transform Modulus Maxima (WTMM) at each scale. The WTMM are related to the shape of the source, so defining some sort of source boundary analysis through the CWT. Wavelets of different order may help to gain resolution and define source features. Selecting a range of scales where the sources behave as if they are approximately isolated, the depth to the source may be estimated basing on the property that the lines joining the modulus maxima of the wavelet coefficients at different scales (WTMML) intersect each other at the edges of the causative body. Therefore, it is possible to manage the information contained in the wavelet transform of fields related to extended sources. In the real case of the anomaly gravity map of the Vesuvius area (Italy), we estimated the depth of the Mesozoic carbonate basement in the Pompei Basin. We showed also how the WTMML information can be integrated to that of another multiscale method, the Depth from Extreme Points (DEXP) transformation, which is also related to the source density distribution of a given region

On Strong Convergence to Equilibrium for the Boltzmann Equation with Soft Potentials

The paper concerns $L^1$- convergence to equilibrium for weak solutions of the spatially homogeneous Boltzmann Equation for soft potentials (-4\le \gm<0), with and without angular cutoff. We prove the time-averaged $L^1$-convergence to equilibrium for all weak solutions whose initial data have finite entropy and finite moments up to order greater than 2+|\gm|. For the usual $L^1$-convergence we prove that the convergence rate can be controlled from below by the initial energy tails, and hence, for initial data with long energy tails, the convergence can be arbitrarily slow. We also show that under the integrable angular cutoff on the collision kernel with -1\le \gm<0, there are algebraic upper and lower bounds on the rate of $L^1$-convergence to equilibrium. Our methods of proof are based on entropy inequalities and moment estimates.Comment: This version contains a strengthened theorem 3, on rate of convergence, considerably relaxing the hypotheses on the initial data, and introducing a new method for avoiding use of poitwise lower bounds in applications of entropy production to convergence problem

Maternal and Paternal Representations in Assisted Reproductive Technology and Spontaneous Conceiving Parents: A Longitudinal Study

Aim of this study was to investigate whether parental mental representations during pregnancy and after delivery differed between parents who conceived after Assisted Reproductive Treatments (ART) and spontaneous conceiving (SC) parents. Effects of specific ART variables (previous ART attempts, treatment type and cause of infertility) were also taken into account. Seventeen ART couples and 25 SC couples were recruited at Santa Maria Nuova Hospital (Reggio Emilia, Italy). At both 32 weeks of gestation (T1) and 3 months postpartum (T2) participants completed the Semantic Differential of the IRMAG, a self-report tool which measures specific domains of mental representations pertaining either individual (Child, Self-as-woman/man, and Partner) or parental (Self-as-parent, Own parent) characteristics. Results showed that ART parents had significantly more positive representations of the child compared to SC parents, while the scores at Partner dimension improved from T1 to T2 for SC parents only. With regards to ART history, scores at the Self-as-woman/man dimension were significantly less positive for ICSI than IVF parents and improved substantially from T1 to T2 only in case of mothers with previous ART attempts and of fathers at the first ART cycle. The representation of own parents increased from T1 to T2 in case of infertility diagnosis due to male factors, while a decrease emerged when infertility was due to female factors. Findings suggest the need to investigate parental mental representations after ART, in order to improve the understanding on the transition to parenthood of infertile couples and to target more specific intervention for parenting support

Características químicas e estoque de carbono dos solos sob diferentes coberturas vegetais e em sistemas tradicionais de uso da terra na região do Alto Solimões - Amazonas.

As atividades humanas transformam os ambientes naturais com diferentes intensidades de manejo e uso do solo. Com o objetivo de verificar as alterações causadas nos solos pelo manejo realizado por agricultores da região, foram feitas seis grades amostrais (janelas), com cento e um pontos ao todo, contendo os sistemas de uso da terra: floresta primária (FP), floresta secundária (FS > sete anos), florestas secundárias (CAP < sete anos), sistemas agroflorestais (SAF?s), roças (RÇ) e pastagens (PAS), no município de Benjamin Constant

Diffeomorphic random sampling using optimal information transport

In this article we explore an algorithm for diffeomorphic random sampling of nonuniform probability distributions on Riemannian manifolds. The algorithm is based on optimal information transport (OIT)---an analogue of optimal mass transport (OMT). Our framework uses the deep geometric connections between the Fisher-Rao metric on the space of probability densities and the right-invariant information metric on the group of diffeomorphisms. The resulting sampling algorithm is a promising alternative to OMT, in particular as our formulation is semi-explicit, free of the nonlinear Monge--Ampere equation. Compared to Markov Chain Monte Carlo methods, we expect our algorithm to stand up well when a large number of samples from a low dimensional nonuniform distribution is needed.Comment: 8 pages, 3 figure

Monuments unveiled: Genetic characterization of large old chestnut (Castanea sativa Mill.) trees using comparative nuclear and chloroplast DNA analysis

Large old trees are extraordinary organisms. They not only represent a historical, landscape and environmental heritage of inestimable value, but they also witness a long history of environmental changes and human interventions, and constitute an as yet poorly known reserve of genetic variability which can be considered a great resource for management programs of forest species. This is the first genetic study on Italian, large, old chestnut trees (Castanea sativa Mill.). Ninety-nine trees were surveyed and analysed. For each tree, more than one sample from canopy and root suckers was collected to test for the genetic integrity of the individuals. All samples were genotyped using nine nuclear microsatellite markers (nSSRs) and 106 unique genetic profiles were identified. A Bayesian analysis performed with the software STRUCTURE revealed the occurrence of two main gene pools and unveiled the genetic relationships existing among the genotyped individuals, and with the natural chestnut populations living in proximity. A phylogeographic structure of the plastid diversity was also obtained by the use of DNA sequence variation at two marker regions, revealing different origins and probable connections of the old trees with different glacial refugia. Our results contribute to an improved evaluation of the European chestnut genetic resources and provide useful insights into the species’ history and domestication in Italy. The importance of carefully targeted conservation strategies for these invaluable organisms is reaffirmed

Річард Смоллі і знамениті «десять вересневих днів»

У вересні цього року виповнюється 27 років, як було відкрито фулерен — нову сфероподібну форму вуглецю. Ця подія буквально приголомшила вчених, які на той час вважали, що про елементарний вуглець їм відомо практично все. Історія відкриття цієї речовини досить незвичайна. Ще в 1971 р. можливість існування молекули фулерену була передбачена японським ученим Е. Осавою (E. Osawa), за два роки радянські хіміки-теоретики Д.А. Бочвар і О.Г. Гальперн квантово-хімічними розрахунками підтвердили стабільність молекули С60, і лише у 1985 р. Р. Смоллі, Р. Керл та Г. Крото експериментально отримали кластери із 60 атомів вуглецю в стійкій формі, яку вони пояснили структурою молекули у вигляді футбольного м’яча. Натхненнику цього відкриття, видатному вченому, нобелівському лауреату, активному популяризатору нанотехнологій Річарду Смоллі присвячено цей матеріал.В сентябре этого года исполняется 27 лет с момента открытия фуллерена — новой сферообразной формы углерода. Это событие буквально потрясло ученых, которые в то время считали, что об элементарном углероде им известно практически все. История открытия этого вещества довольно необычна. Еще в 1971 г. возможность су ществования молекулы фуллерена была предсказана японским ученым Е. Осавой (E. Osawa), через два года советские химики-теоретики Д.А. Бочвар и Е.Г. Гальперн с помощью квантово-химических расчетов подтвердили стабильность молекулы С60, и только в 1985 г. Р. Смолли, Р. Керл и Г. Крото экспериментально получили кластеры из 60 атомов углерода в устойчивой форме, которую они объяснили структурой молекулы в виде футбольного мяча. Вдохновителю этого открытия, выдающемуся ученому, нобелевскому лауреату, активному популяризатору нанотехнологий Ричарду Смолли посвящен этот материал.27 years since the discovery of fullerene, the new form of carbon, is observed in September of this year. This event has literally shocked scientists, who believed at that time that they know almost everything about the elementary carbon. History of this discovery is rather unusual. Long ago, in 1971 the possibility of the existence of a fullerene molecule was predicted by an young Japanese scientist E. Osawa. Then two Soviet chemists and theorists D.A. Bochvar and E.G. Hal pern confirm the stability of the C60 molecule using quantum chemical calculations, and in 1985 at last R. Smalley, R. Curl and H. Kroto experimentally obtained clusters of 60 carbon atoms in a sustainable form. They explained the structure of this molecule as the structure of a soccer ball. This material is devoted to the inspirer of this discovery, an outstanding scientist, Nobel laureate, active popularizer of nanotechnology — Richard Smalley

Celebrating Cercignani's conjecture for the Boltzmann equation

Cercignani's conjecture assumes a linear inequality between the entropy and entropy production functionals for Boltzmann's nonlinear integral operator in rarefied gas dynamics. Related to the field of logarithmic Sobolev inequalities and spectral gap inequalities, this issue has been at the core of the renewal of the mathematical theory of convergence to thermodynamical equilibrium for rarefied gases over the past decade. In this review paper, we survey the various positive and negative results which were obtained since the conjecture was proposed in the 1980s.Comment: This paper is dedicated to the memory of the late Carlo Cercignani, powerful mind and great scientist, one of the founders of the modern theory of the Boltzmann equation. 24 pages. V2: correction of some typos and one ref. adde

Particle approximation of the one dimensional Keller-Segel equation, stability and rigidity of the blow-up

We investigate a particle system which is a discrete and deterministic approximation of the one-dimensional Keller-Segel equation with a logarithmic potential. The particle system is derived from the gradient flow of the homogeneous free energy written in Lagrangian coordinates. We focus on the description of the blow-up of the particle system, namely: the number of particles involved in the first aggregate, and the limiting profile of the rescaled system. We exhibit basins of stability for which the number of particles is critical, and we prove a weak rigidity result concerning the rescaled dynamics. This work is complemented with a detailed analysis of the case where only three particles interact