TVL₁shape approximation from scattered 3D data

With the emergence in 3D sensors such as laser scanners and 3D reconstruction from cameras, large 3D point clouds can now be sampled from physical objects within a scene. The raw 3D samples delivered by these sensors however, contain only a limited degree of information about the environment the objects exist in, which means that further geometrical high-level modelling is essential. In addition, issues like sparse data measurements, noise, missing samples due to occlusion, and the inherently huge datasets involved in such representations makes this task extremely challenging. This paper addresses these issues by presenting a new 3D shape modelling framework for samples acquired from 3D sensor. Motivated by the success of nonlinear kernel-based approximation techniques in the statistics domain, existing methods using radial basis functions are applied to 3D object shape approximation. The task is framed as an optimization problem and is extended using non-smooth L1 total variation regularization. Appropriate convex energy functionals are constructed and solved by applying the Alternating Direction Method of Multipliers approach, which is then extended using Gauss-Seidel iterations. This significantly lowers the computational complexity involved in generating 3D shape from 3D samples, while both numerical and qualitative analysis confirms the superior shape modelling performance of this new framework compared with existing 3D shape reconstruction techniques

Optimized and robust experimental design: a non-linear application to EM sounding

Pragmatic experimental design requires objective consideration of several classes of information including the survey goals, the range of expected Earth responses, acquisition costs, instrumental capabilities, experimental conditions and logistics. In this study we consider the ramifications of maximizing model parameter resolution through non-linear experimental design. Global optimization theory is employed to examine and rank different EM sounding survey designs in terms of model resolution as defined by linearized inverse theory. By studying both theoretically optimal and heuristic experimental survey configurations for various quantities of data, it is shown that design optimization is critical for minimizing model variance estimates, and is particularly important when the inverse problem becomes nearly underdetermined. We introduce the concept of robustness so that survey designs are relatively immune to the presence of potential bias errors in important data. Bias may arise during practical measurement, or from designing a survey using an appropriate mode

Rippling patterns in aggregates of myxobacteria arise from cell-cell collisions

Experiments with myxobacterial aggregates reveal standing waves called rippling patterns. Here, these structures are modelled with a simple discrete model based on the interplay between migration and collisions of cells. Head-to-head collisions of cells result in cell reversals. To correctly reproduce the rippling patterns, a refractory phase after each cell reversal has to be assumed, during which further reversal is prohibited. The duration of this phase determines the wavelength and period of the ripple patterns as well as the reversal frequency of single cells

Fluctuations of the Magnetization in Thin Films due to Conduction Electrons

A detailed analysis of damping and noise due to a {\it sd}-interaction in a thin ferromagnetic film sandwiched between two large normal metal layers is carried out. The magnetization is shown to obey in general a non-local equation of motion which differs from the the Gilbert equation and is extended to the non-adiabatic regime. To lowest order in the exchange interaction and in the limit where the Gilbert equation applies, we show that the damping term is enhanced due to interfacial effects but it also shows oscillations as a function of the film thickness. The noise calculation is however carried out to all orders in the exchange coupling constant. The ellipticity of the precession of the magnetization is taken into account. The damping is shown to have a Gilbert form only in the adiabatic limit while the relaxation time becomes strongly dependent on the geometry of the thin film. It is also shown that the induced noise characteristic of sd-exchange is inherently colored in character and depends on the symmetry of the Hamiltonian of the magnetization in the film. We show that the sd-noise can be represented in terms of an external stochastic field which is white only in the adiabatic regime. The temperature is also renormalized by the spin accumulation in the system. For large intra-atomic exchange interactions, the Gilbert-Brown equation is no longer valid

Sex differences in the efficacy of psychological therapies for the management of chronic and recurrent pain in children and adolescents:a systematic review and meta-analysis

Sex differences in chronic pain are reported to emerge during adolescence, although it is unclear if this includes responses to treatment. We conducted a meta-analysis to examine whether sex differences were present on outcome variables at pre-treatment, and whether the efficacy of psychological therapies for pediatric chronic pain differs between boys and girls at post-treatment and follow-up time points. Searches were conducted, extending two existing Cochrane reviews of randomized-controlled trials examining the efficacy of psychological therapies for chronic and recurrent pain in children and adolescents. Forty-six articles were eligible for inclusion, and data were extracted regarding pain, disability, anxiety, and depression in boys and girls at pre-treatment, post-treatment, and follow-up time points. No published study reported outcome data separately by sex, so authors of all studies were contacted and 17 studies provided data. Twice as many girls (n =1760) were enrolled into clinical trials of psychological therapies for pediatric chronic pain than boys (n = 828). Girls reported higher depression and anxiety at pre-treatment than boys. Girls with headache also reported significantly greater pre-treatment pain severity. Treatment gains were consistent across the sexes. One exception was for post-treatment disability in children with non-headache pain conditions; girls exhibited a significant effect of treatment relative to control condition (SMD= -0.50[-0.80,-0.20], p &lt; .01), but no such effect was observed for boys (SMD= -0.08[-0.44,0.28], p = .66). Future research should examine whether mechanisms of treatment efficacy differ between boys and girls, and consider the impact of pre-treatment sex differences on response to treatment.</p

Matriptase regulates c-Met mediated proliferation and invasion in inflammatory breast cancer.

The poor prognosis for patients with inflammatory breast cancer (IBC) compared to patients with other types of breast cancers emphasizes the need to better understand the molecular underpinnings of this disease with the goal of developing effective targeted therapeutics. Dysregulation of matriptase expression, an epithelial-specific member of the type II transmembrane serine protease family, has been demonstrated in many different cancer types. To date, no studies have assessed the expression and potential pro-oncogenic role of matriptase in IBC. We examined the functional relationship between matriptase and the HGF/c-MET signaling pathway in the IBC cell lines SUM149 and SUM190, and in IBC patient samples. Matriptase and c-Met proteins are localized on the surface membrane of IBC cells and their expression is strongly correlated in infiltrating cancer cells and in the cancer cells of lymphatic emboli in patient samples. Abrogation of matriptase expression by silencing with RNAi or inhibition of matriptase proteolytic activity with a synthetic inhibitor impairs the conversion of inactive pro-HGF to active HGF and subsequent c-Met-mediated signaling, leading to efficient impairment of proliferation and invasion of IBC cells. These data show the potential of matriptase inhibitors as a novel targeted therapy for IBC, and lay the groundwork for the development and testing of such drugs

Effect of P-glycoprotein on flavopiridol sensitivity

Flavopiridol is the first potent inhibitor of cyclin-dependent kinases (CDKs) to enter clinical trials. Little is known about mechanisms of resistance to this agent. In order to determine whether P-glycoprotein (Pgp) might play a role in flavopiridol resistance, we examined flavopiridol sensitivity in a pair of Chinese hamster ovary cell lines differing with respect to level of Pgp expression. The IC 50 s of flavopiridol in parental AuxB1 (lower Pgp) and colchicine-selected CHRC5 (higher Pgp) cells were 90.2 ± 6.6 nM and 117 ± 2.3 nM, respectively (P< 0.01), suggesting that Pgp might have a modest effect on flavopiridol action. Consistent with this hypothesis, pretreatment with either quinidine or verapamil (inhibitors of Pgp-mediated transport) sensitized CHRC5 cells to the antiproliferative effects of flavopiridol. Because of concern that colony forming assays might not accurately reflect cytotoxicity, we also examined flavopiridol-treated cells by trypan blue staining and flow cytometry. These assays confirmed that flavopiridol was less toxic to cells expressing higher levels of Pgp. Further experiments revealed that flavopiridol inhibited the binding of [3H]-azidopine to Pgp in isolated membrane vesicles, but only at high concentrations. Collectively, these results identify flavopiridol as a weak substrate for Pgp. © 2001 Cancer Research Campaign www.bjcancer.co

Adult judgments of children’s pain and fear during venipuncture: The impact of adult and child sex

Background: Low levels of agreement between caregiver and child reports of acute pain are well documented. Aims: This study builds on prior research through exploring factors that may contribute to low caregiver–child concordance. Specifically, the study examined the influence of adult and child sex on adult judgments of children’s pain and fear during venipuncture and examined whether trait parental pain catastrophizing, empathy, and anxiety predicted judgment accuracy. Methods: Using a judgment study paradigm, 160 participants (82 women) viewed 20 10-s video clips of children (10 boys, 10 girls) undergoing venipuncture and rated each child’s pain and fear. Adults’ ratings were compared to the children’s own ratings. Adults completed measures of trait parental pain catastrophizing, dispositional empathy, and trait anxiety. Results: Adults accurately judged boys’ pain and fear significantly more often than that of girls. Further, adults underestimated and overestimated girls’ pain and overestimated girls’ fear significantly more frequently than that of boys. No effects of adult sex or adult by child sex interactions emerged. Parental pain catastrophizing significantly predicted underestimation of girls’ pain, with adults who engaged in more catastrophizing being less likely to underestimate girls’ pain. The variables did not predict adult judgment of child pain for women and men separately and did not predict adult judgment of child fear when examined by adult sex, child sex, or both combined. Conclusions: Child sex influences adult pain and fear judgments, with girls being more vulnerable to inaccurate assessment than boys. Higher levels of parental pain catastrophizing may buffer against adults’ propensities to underestimate girls’ pain

Sex differences in experimental pain among healthy children: A systematic review and meta-analysis

Sex differences in response to experimental pain are commonly reported in systematic reviews in the adult literature. The objective of the present research was to conduct a systematic review and meta-analysis of sex differences in healthy children's responses to experimental pain (eg, cold pressor, heat pain, pressure pain) and, where possible, to conduct analyses separately for children and adolescents. A search was conducted of electronic databases for published papers in English of empirical research using experimental pain tasks to examine pain-related outcomes in healthy boys and girls between 0 and 18 years of age. Eighty articles were eligible for inclusion and were coded to extract information relevant to sex differences. The systematic review indicated that, across different experimental pain tasks, the majority of studies reported no significant differences between boys and girls on pain-related outcomes. However, the meta-analysis of available combined data found that girls reported significantly higher cold pressor pain intensity compared to boys in studies where the mean age of participants was greater than 12 years. Additionally, a meta-analysis of heat pain found that boys had significantly higher tolerance than girls overall, and boys had significantly higher heat pain threshold than girls in studies where the mean age of participants was 12 years or younger. These findings suggest that developmental stage may be relevant for understanding sex differences in pain