Simplicial homeomorphs and trace-bounded hypergraphs

Our first main result is a uniform bound, in every dimension $k \in \mathbb N$, on the topological Tur\'an numbers of $k$-dimensional simplicial complexes: for each $k \in \mathbb N$, there is a $\lambda_k \ge k^{-2k^2}$ such that for any $k$-complex $\mathcal{S}$, every $k$-complex on $n \ge n_0(\mathcal{S})$ vertices with at least $n^{k+1 - \lambda_k}$ facets contains a homeomorphic copy of $\mathcal{S}$. This was previously known only in dimensions one and two, both by highly dimension-specific arguments: the existence of $\lambda_1$ is a result of Mader from 1967, and the existence of $\lambda_2$ was suggested by Linial in 2006 and recently proved by Keevash-Long-Narayanan-Scott. We deduce this geometric fact from a purely combinatorial result about trace-bounded hypergraphs, where an $r$-partite $r$-graph $H$ with partite classes $V_1, V_2, \dots, V_r$ is said to be $d$-trace-bounded if for each $2 \le i \le r$, all the vertices of $V_i$ have degree at most $d$ in the trace of $H$ on $V_1 \cup V_2 \cup \dots \cup V_i$. Our second main result is the following estimate for the Tur\'an numbers of degenerate trace-bounded hypergraphs: for all $r \ge 2$ and $d\in\mathbb N$, there is an $\alpha_{r,d} \ge (5rd)^{1-r}$ such that for any $d$-trace-bounded $r$-partite $r$-graph $H$, every $r$-graph on $n \ge n_0(H)$ vertices with at least $n^{r - \alpha_{r,d}}$ edges contains a copy of $H$. This strengthens a result of Conlon-Fox-Sudakov from 2009 who showed that such a bound holds for $r$-partite $r$-graphs $H$ satisfying the stronger hypothesis that the vertex-degrees in all but one of its partite classes are bounded (in $H$, as opposed to in its traces).Comment: 9 page

Stochastic Downsampling for Cost-Adjustable Inference and Improved Regularization in Convolutional Networks

It is desirable to train convolutional networks (CNNs) to run more efficiently during inference. In many cases however, the computational budget that the system has for inference cannot be known beforehand during training, or the inference budget is dependent on the changing real-time resource availability. Thus, it is inadequate to train just inference-efficient CNNs, whose inference costs are not adjustable and cannot adapt to varied inference budgets. We propose a novel approach for cost-adjustable inference in CNNs - Stochastic Downsampling Point (SDPoint). During training, SDPoint applies feature map downsampling to a random point in the layer hierarchy, with a random downsampling ratio. The different stochastic downsampling configurations known as SDPoint instances (of the same model) have computational costs different from each other, while being trained to minimize the same prediction loss. Sharing network parameters across different instances provides significant regularization boost. During inference, one may handpick a SDPoint instance that best fits the inference budget. The effectiveness of SDPoint, as both a cost-adjustable inference approach and a regularizer, is validated through extensive experiments on image classification

Sentinel lymph node biopsy based on anatomical landmarks and locoregional mapping of inguinofemoral sentinel lymph nodes in women with vulval cancer:an operative technique

Inguinal lymph node involvement is the most robust predictor of mortality in vulval cancer and sentinel lymph node (SLN) biopsy is a safe diagnostic modality. We describe a technique based on anatomical landmarks. Our aims are (1) to describe the territorial mapping of SLNs, (2) to evaluate the associated complication rate vis-à-vis those reported in the literature, and (3) to assess its accuracy in detecting SLNs. Data from women who underwent groin SLN biopsies for vulval cancer at a single cancer centre were prospectively collected. All subjects met the GROINSS-V eligibility criteria. The location of the SLN relative to the saphenous vein was recorded. All women were followed up and early and late complications were recorded. The recurrence rate at the time of the census was calculated. A total of 71 groins in 44 women were included. The SLN was primarily located over Cloquet’s node (85.2%). The incidence of early wound cellulitis and dehiscence were 2.8% and 11.3% while lymphocysts were present in 11.3% of groins. The negative nodal recurrence rate was 1.7%. Results showed that this reproducible technique allows access to 96.7% of SLNs, including both deep and superficial SLNs whilst minimising the need for extensive dissection and complications associated with overharvesting of lymph nodes

Improving the outcome of patients with premalignant and malignant disorders of the vulva

Research presented in this thesis was driven by the need to identify risk factors that predict local recurrence (LVR) in patients with vulval cancer (VSCC), and the need for more effective treatments for women with vulvar intraepithelial neoplasia (VIN). To identify the risk factors that predispose women to LVR, a multivariate analysis was performed on a well-characterized cohort of women treated for VSCC. This analysis revealed that the only independent predictor of LVR was the presence of Lichen Sclerosis (LS). These women were five times more likely to recur than those without LS. VIN is a recognised precursor lesion of HPV-positive VSCC. Topical application of Epigallocatechin-3-gallate (EGCG), a green tea polyphenol, has been shown to be an effective treatment for genital warts; a condition caused by HPV. Although the mechanism(s) by which EGCG influences the growth of HPV-associated proliferative disorders are unknown, I demonstrate that EGCG inhibits cell proliferation and promotes apoptosis, an effect that was accompanied by down-regulation of the E6 and E7 proteins and the induction of p53, p21 and pRb. Biochemical analysis revealed that EGCG did not stimulate E6 degradation by enhancing poly-ubiquitination and proteasome-mediated degradation, suggesting that EGCG-mediated E6 proteolysis occurred through other mechanisms

A comparison of two physical data designs for interactive social networking actions

This paper compares the performance of an SQL solution that implements a relational data model with a document store named MongoDB. We report on the performance of a single node configuration of each data store and assume the database is small enough to fit in main memory. We analyze utilization of the CPU cores and the network bandwidth to compare the two data stores. Our key findings are as follows. First, for those social networking actions that read and write a small amount of data, the join operator of the SQL solution is not slower than the JSON representation of MongoDB. Second, with a mix of actions, the SQL solution provides either the same performance as MongoDB or outperforms it by 20%. Third, a middle-tier cache enhances the performance of both data stores as query result look up is significantly faster than query processing with either system.

FingerSlide: Investigating Passive Haptic Sliding As A Tacton Channel

The haptic sensation of sliding a surface under a probing finger can be used to convey surface information or coded data to the user. In this paper, we investigate users' ability to discern different sliding profiles based on the velocity and direction of sliding for use as haptic-tactons. We built FingerSlide, a novel haptic device which can position and control moving surfaces under a user's finger and used this to run two independent studies. The first study investigates if users can identify the direction of sliding at different velocities. The second study investigates if the users can distinguish a difference between two velocities. Our results show a faster response for higher velocities in the direction study and high error rates in identifying differences in the direction study. We discuss these results and infer design considerations for haptic devices that use the sliding effect to convey information

Assessing the expected current and future competencies of quantity surveyors in the Malaysian built environment

Purpose: Quantity surveying is a profession that blends engineering, construction and economics. To be competent is to have the ability to apply the set of related knowledge, skills and abilities to perform a task effectively. This paper examines the competency requirements for quantity surveyors (QSs) in the face of changing and increasing client needs. Design/methodology/approach: Based on a detailed meta-analysis of the literature, 12 basic/core and 16 evolving competencies are identified. Primary data were gathered through a field survey involving practicing QSs from client, consultant and contractor organisations, and university students undertaking QS programmes in Malaysia. The data obtained were analysed using both descriptive and inferential statistical tools. Findings: The significance of the basic/core and evolving competencies are presented. Overall, the most important contemporary skills are cost planning, valuation of works, measurement/quantification and contract documentation. The evolved roles require expertise in communication and negotiation, ethics and professional conduct and value management. The analysis of variance (ANOVA) indicates there are misaligned expectations of the proficiency levels needed to provide contemporary and future services between practitioners in client/consultant organisations, contractors and new generation students. Originality/value: The findings provide guidance on the education, training and practice of quantity surveying to deal with emerging challenges in the dynamic built environments in Malaysia and beyond.</p

Completing a genomic characterisation of microscopic tumour samples with copy number

Background: Genomic insights in settings where tumour sample sizes are limited to just hundreds or even tens of cells hold great clinical potential, but also present significant technical challenges. We previously developed the DigiPico sequencing platform to accurately identify somatic mutations from such samples. Results: Here, we complete this genomic characterisation with copy number. We present a novel protocol, PicoCNV, to call allele-specific somatic copy number alterations from picogram quantities of tumour DNA. We find that PicoCNV provides exactly accurate copy number in 84% of the genome for even the smallest samples, and demonstrate its clinical potential in maintenance therapy. Conclusions: PicoCNV complements our existing platform, allowing for accurate and comprehensive genomic characterisations of cancers in settings where only microscopic samples are available

Design and Analysis of Haptic-Audio Based System for the Visually Impaired to Shop Online

Many visually impaired customers are keen to shop online, however, they often encounter accessibility barriers such as accessing and interpreting complex designed websites and when trying to make online payment which required them to input card details by filling up payment form. In order to study whether the visually impaired could shop online without assistance, an online store which has features such as product catalogue, shopping cart and payment system was developed. The system utilizes the Falcon haptic device and voice recognition for navigation, interaction, accessing and haptic evaluation of products. Some of our qualitative analysis suggests that a framed three-section design product catalogue with directed dialogue, directional cues, audio information along with a haptic-audio enabled browser is feasible for the visually impaired to browse, select and haptically evaluate products; a XHTML and VoiceXML based shopping cart system can enable the visually impaired to interact and verify its contents; and a voice password based payment system can be used to automate forms data entry process and to help the visually impaired to make online payment independently