Exploiting the Hard-Working DWARF: Trojan and Exploit Techniques Without Native Executable Code

The study of vulnerabilities and exploitation is one of finding mechanisms affecting the flow of computation and of finding new means to perform unexpected computation. In this paper we show the extent to which exception handling mechanisms as implemented and used by \gcc can be used to control program execution. We show that the data structures used to store exception handling information on UNIX-like systems actually contain Turing-complete bytecode, which is executed by a virtual machine during the course of exception unwinding and handling. We discuss how a malicious attacker could gain control over these structures and how such an attacker could utilize them once control has been achieved

A Variable Dispersion Flow Injection Manifold for Calibration and Sample Dilution in Flame Atomic Absorption Spectrometry

A flow injection (FI) introduction system for flame atomic absorption spectrometry (FAAS) has been constructed for single-standard calibration and sample dilution. Dilution factors ranging from 5.93 to 38.8 in six discrete stages were produced by replicate injection of 12.5-pl volumes into an aqueous carrier stream flowing down lines of different lengths. The dilution factors were measured for five different solutions for each line. No dependence on concentration was found and the relative standard deviations ranged from 0.75 to 3.1%. The manifold was evaluated by the analysis of solutions of magnesium (6,12.5 and 35 p.p.m.), nickel (180 p.p.m.), calcium (75 p.p.m.) and chromium (180 p.p.m.). Recoveries ranging from 95.3 to 106.8% were obtained with no over-all evidence of bias. The uncertainty in the over-all method, including a contribution from the curve-fitting procedure, was estimated to be 5%

Hastings-Levitov aggregation in the small-particle limit

We establish some scaling limits for a model of planar aggregation. The model is described by the composition of a sequence of independent and identically distributed random conformal maps, each corresponding to the addition of one particle. We study the limit of small particle size and rapid aggregation. The process of growing clusters converges, in the sense of Caratheodory, to an inflating disc. A more refined analysis reveals, within the cluster, a tree structure of branching fingers, whose radial component increases deterministically with time. The arguments of any finite sample of fingers, tracked inwards, perform coalescing Brownian motions. The arguments of any finite sample of gaps between the fingers, tracked outwards, also perform coalescing Brownian motions. These properties are closely related to the evolution of harmonic measure on the boundary of the cluster, which is shown to converge to the Brownian web

Addition of salmeterol to fluticasone propionate treatment in moderate-to-severe asthma

AbstractThis study was designed to determine whether the benefit of adding salmeterol was superior to doubling the dose of fluticasone propionate (FP) over 6 months, compared to a control group who remained on a lower dose of FP. The multi-centre, double-blind, parallel group study involved 496 symptomatic asthmatic patients with a history of exacerbations on 500–800 micrograms (μg) inhaled corticosteroids (ICS) twice daily (b.d.) in a broadly representative group of 100 hospitals and general practices in six countries. Two doses of FP—250 μg b.d. (FP250) or 500 μg b.d. (FP500)—were compared with the lower dose of FP plus a long-acting β2-agonist, salmeterol 50 μg b.d. (SM/FP250). Patients symptomatic on the run-in dose of FP250 alone formed the control group in the treatment period. Over 6 months, SM/FP250 significantly improved mean morning peak expiratory flow rates (amPEF) by 42.1l/min, more than twice the improvement achieved with either dose of FP alone. SM/FP250 also resulted in more symptom-free days and nights (P<0.002) and days and nights with no relief medication (P<0.001). The number of severe exacerbations was low: 3, 6 and 8% in the SM/FP250, low- and high-dose FP groups, respectively. This study confirms that adding salmeterol to low-dose inhaled FP offers greater improvements than either maintaining or doubling the dose of FP. Significant benefit was gained from adding salmeterol in a group of patients who appeared to have been at the top of their steroid dose–response curve receiving FP250. There was no evidence of tolerance and a low incidence of exacerbations in all treatment groups

Visual motherese? Signal-to-noise ratios in toddler-directed television

Younger brains are noisier information processing systems; this means that information for younger individuals has to allow clearer differentiation between those aspects that are required for the processing task in hand (the ‘signal’) and those that are not (the ‘noise’). We compared toddler-directed and adult-directed TV programmes (TotTV/ATV). We examined how low-level visual features (that previous research has suggested influence gaze allocation) relate to semantic information, namely the location of the character speaking in each frame. We show that this relationship differs between TotTV and ATV. First, we conducted Receiver Operator Characteristics analyses and found that feature congestion predicted speaking character location in TotTV but not ATV. Second, we used multiple analytical strategies to show that luminance differentials (flicker) predict face location more strongly in TotTV than ATV. Our results suggest that TotTV designers have intuited techniques for controlling toddler attention using low-level visual cues. The implications of these findings for structuring childhood learning experiences away from a screen are discussed

Hydrodynamic Modes for Granular Gases

The eigenfunctions and eigenvalues of the linearized Boltzmann equation for inelastic hard spheres (d=3) or disks (d=2) corresponding to d+2 hydrodynamic modes, are calculated in the long wavelength limit for a granular gas. The transport coefficients are identified and found to agree with those from the Chapman-Enskog solution. The dominance of hydrodynamic modes at long times and long wavelengths is studied via an exactly solvable kinetic model. A collisional continuum is bounded away from the hydrodynamic spectrum, assuring a hydrodynamic description at long times. The bound is closely related to the power law decay of the velocity distribution in the reference homogeneous cooling state

Development of a cytology-based multivariate analytical risk index for oral cancer

Objectives The diagnosis and management of oral cavity cancers are often complicated by the uncertainty of which patients will undergo malignant transformation, obligating close surveillance over time. However, serial biopsies are undesirable, highly invasive, and subject to inherent issues with poor inter-pathologist agreement and unpredictability as a surrogate for malignant transformation and clinical outcomes. The goal of this study was to develop and evaluate a Multivariate Analytical Risk Index for Oral Cancer (MARIO) with potential to provide non-invasive, sensitive, and quantitative risk assessments for monitoring lesion progression. Materials and methods A series of predictive models were developed and validated using previously recorded single-cell data from oral cytology samples resulting in a “continuous risk score”. Model development consisted of: (1) training base classification models for each diagnostic class pair, (2) pairwise coupling to obtain diagnostic class probabilities, and (3) a weighted aggregation resulting in a continuous MARIO. Results and conclusions Diagnostic accuracy based on optimized cut-points for the test dataset ranged from 76.0% for Benign, to 82.4% for Dysplastic, 89.6% for Malignant, and 97.6% for Normal controls for an overall MARIO accuracy of 72.8%. Furthermore, a strong positive relationship with diagnostic severity was demonstrated (Pearson’s coefficient = 0.805 for test dataset) as well as the ability of the MARIO to respond to subtle changes in cell composition. The development of a continuous MARIO for PMOL is presented, resulting in a sensitive, accurate, and non-invasive method with potential for enabling monitoring disease progression, recurrence, and the need for therapeutic intervention of these lesions

Estimation of lung growth using computed tomography

Anatomical studies suggest that normal lungs grow by rapid alveolar addition until about 2 yrs of age followed by a gradual increase in alveolar dimensions. The aim of this study was to examine the hypothesis that normal lung growth can be monitored by computed tomography (CT). Therefore, the gas volume per gram of lung tissue was estimated from measurements of lung density obtained from CT scans performed on children throughout the growth period. CT scans were performed on 17 males and 18 females, ranging in age from 15 days-17.6 yrs. CT-measured lung weight was correlated with predicted post mortem values and CT measured gas volume with predicted values of functional residual capacity. The median value for lung expansion was 1.86 mL x g(-1) at 15 days, decreased to 0.79 mL x g(-1) by 2 yrs and then increased steadily to 5.07 mL x g(-1) at 17 yrs. Computed tomography scans can be used to estimate lung weight, gas volume and expansion of normal lungs during the growth period. The increase in the lung expansion after the age of 2 yrs suggests progressive alveolar expansion with increasing lung volume