Expression of patched, prdm1 and engrailed in the lamprey somite reveals conserved responses to Hedgehog signaling

In the zebrafish embryo, expression of the prdm1 and patched1 genes in adaxial cells is indicative of their specification to give rise to slow twitch muscle fibers in response to Hedgehog (Hh) signaling. Subsets of these slow twitch muscle progenitors activate engrailed (eng) strongly in response to high-level Hh signaling, and differentiate into muscle pioneer cells, which are important for subsequent development of the horizontal myoseptum. In addition, eng is expressed more weakly in medial fast fibers in response to lower Hh levels. Somite morphology in the lamprey, an agnathan (jawless) vertebrate, differs significantly from that of teleosts. In particular, the lamprey does not have clear epaxial/hypaxial domains, lacks a horizontal myoseptum, and does not appear to possess distinct populations of fast and slow fibers in the embryonic somite. Nevertheless, Hh is expressed in the midline of the lamprey embryo, and we report here that, as in zebrafish, homologues of patched and prdm1 are expressed in adaxial regions of the lamprey somite, and an eng homologue is also expressed in the somite. However, the lamprey adaxial region does not exhibit the same distinct adaxial cell morphology as in the zebrafish. In addition, the expression of follistatin is not excluded from the adaxial region, and eng is not detected in discrete muscle pioneer-like cells. These data suggest the presence of conserved responses to Hh signaling in lamprey somites, although the full range of effects elicited by Hh in the zebrafish somite is not recapitulated

Synthetic Data Generation and Defense in Depth Measurement of Web Applications

Measuring security controls across multiple layers of defense requires realistic data sets and repeatable experiments. However, data sets that are collected from real users often cannot be freely exchanged due to privacy and regulatory concerns. Synthetic datasets, which can be shared, have in the past had critical flaws or at best been one time collections of data focusing on a single layer or type of data. We present a framework for generating synthetic datasets with normal and attack data for web applications across multiple layers simultaneously. The framework is modular and designed for data to be easily recreated in order to vary parameters and allow for inline testing. We build a prototype data generator using the framework to generate nine datasets with data logged on four layers: network, file accesses, system calls, and database simultaneously. We then test nineteen security controls spanning all four layers to determine their sensitivity to dataset changes, compare performance even across layers, compare synthetic data to real production data, and calculate combined defense in depth performance of sets of controls

Defects and rescue of the minor salivary glands in Eda pathway mutants

AbstractDespite their importance to oral health, the mechanisms of minor salivary gland (SG) development are largely unexplored. Here we present in vivo and in vitro analyses of developing minor SGs in wild type and mutant mice. Eda, Shh and Fgf signalling pathway genes are expressed in these glands from an early stage of development. Developing minor SGs are absent in Eda pathway mutant embryos, and these mice exhibit a dysplastic circumvallate papilla with disrupted Shh expression. Supplementation of Eda pathway mutant minor SG explants with recombinant EDA rescues minor SG induction. Supplementation with Fgf8 or Shh, previously reported targets of Eda signalling, leads to induction of gland like structures in a few cases, but these fail to develop into minor SGs

A methodology for designing accurate anomaly detection systems

Anomaly detection systems have the potential to detect zero-day attacks. However, these systems can suffer from high rates of false positives and can be evaded through through mimicry attacks. The key to addressing both problems is careful control of model generalization. An anomaly detection system that undergeneralizes generates too many false positives, while one that overgeneralizes misses attacks. In this paper, we present a methodology for creating anomaly detection systems that make appropriate trade-offs regarding model precision and generalization. Specifically, we propose that systems be created by taking an appropriate, undergeneralizing data modeling method and extending it using data pre-processing generalization heuristics. To show the utility of our methodology, we show how it has been applied to the problem of detecting malicious web requests. Copyright 2007 ACM

Incorporation of application layer protocol syntax into anomaly detection

Abstract. The syntax of application layer protocols carries valuable information for network intrusion detection. Hence, the majority of modern IDS perform some form of protocol analysis to refine their signatures with application layer context. Protocol analysis, however, has been mainly used for misuse detection, which limits its application for the detection of unknown and novel attacks. In this contribution we address the issue of incorporating application layer context into anomaly-based intrusion detection. We extend a payload-based anomaly detection method by incorporating structural information obtained from a protocol analyzer. The basis for our extension is computation of similarity between attributed tokens derived from a protocol grammar. The enhanced anomaly detection method is evaluated in experiments on detection of web attacks, yielding an improvement of detection accuracy of 49%. While byte-level anomaly detection is sufficient for detection of buffer overflow attacks, identification of recent attacks such as SQL and PHP code injection strongly depends on the availability of application layer context

Location Patterns of Creative Capital and Regional Disparities in Spain

The creative class as a source of growth has been afforded increasing attention in recent years. However, creative people are not distributed evenly across space, tending rather to concentrate in particular locations. The location decisions of these creative people have been forwarded as a significant factor in accounting for regional disparities in growth and development (Florida, 2002; Fritsch and Stuetzer, 2009). Inspired by the ongoing debate surrounding the creative class theory, this study investigates the spatial distribution of creative capital and its links with regional disparities by examining the geographical divergence of provincial income in Spain. Our findings indicate that although provinces with low levels of creative capital around 1996 experienced an increase in their creative employment in the years leading up to 2004, they still lag behind the northern (and, in particular, the north-eastern) provinces of Spain. More interestingly we report strong spillover effects among the leading and lagging provinces. This spatial pattern of creative capital also accounts for the north-south divide in Spain. Thus, our empirical evidence shows that the provinces with high levels of creative capital in northern Spain are more developed in terms of provincial income even when controlling for other determinants of the process, including industrial development, regional spillover effects and human capital development

The transcription factor SOX6 contributes to the developmental origins of obesity by promoting adipogenesis

Development (Cambridge)1436950 - 96

Quantifying the magnitude of a missing hydroxyl radical source in a tropical rainforest

The lifetime of methane is controlled to a very large extent by the abundance of the OH radical. The tropics are a key region for methane removal, with oxidation in the lower tropical troposphere dominating the global methane removal budget (Bloss et al., 2005). In tropical forested environments where biogenic VOC emissions are high and NO[subscript x] concentrations are low, OH concentrations are assumed to be low due to rapid reactions with sink species such as isoprene. New, simultaneous measurements of OH concentrations and OH reactivity, k'[subscript OH'], in a Borneo rainforest are reported and show much higher OH than predicted, with mean peak concentrations of ~2.5×10[superscript 6] molecule cm[superscript −3] (10 min average) observed around solar noon. Whilst j(O[superscript 1]D) and humidity were high, low O[subscript 3] concentrations limited the OH production from O[subscript 3] photolysis. Measured OH reactivity was very high, peaking at a diurnal average of 29.1±8.5 s[superscript −1], corresponding to an OH lifetime of only 34 ms. To maintain the observed OH concentration given the measured OH reactivity requires a rate of OH production approximately 10 times greater than calculated using all measured OH sources. A test of our current understanding of the chemistry within a tropical rainforest was made using a detailed zero-dimensional model to compare with measurements. The model over-predicted the observed HO[subscript 2] concentrations and significantly under-predicted OH concentrations. Inclusion of an additional OH source formed as a recycled product of OH initiated isoprene oxidation improved the modelled OH agreement but only served to worsen the HO2 model/measurement agreement. To replicate levels of both OH and HO[subscript 2], a process that recycles HO[subscript 2] to OH is required; equivalent to the OH recycling effect of 0.74 ppbv of NO. This recycling step increases OH concentrations by 88% at noon and has wide implications, leading to much higher predicted OH over tropical forests, with a concomitant reduction in the CH[subscript 4] lifetime and increase in the rate of VOC degradation

Measurements of iodine monoxide at a semi polluted coastal location

Point source measurements of IO by laser induced fluorescence spectroscopy were made at a semi-polluted coastal location during the Reactive Halogens in the Marine Boundary Layer (RHaMBLe) campaign in September 2006. The site, on the NW French coast in Roscoff, was characterised by extensive intertidal macroalgae beds which were exposed at low tide. The closest known iodine active macroalgae beds were at least 300m from the measurement point. From 20 days of measurements, IO was observed above the instrument limit of detection on 14 days, of which a clear diurnal profile was observed on 11 days. The maximum IO mixing ratio was 30.0 pptv (10 s integration period) during the day, amongst the highest concentrations ever observed in the atmosphere, and 1–2 pptv during the night. IO concentrations were strongly dependent on tidal height, the intensity of solar irradiation and meteorological conditions. An intercomparison of IO measurements made using point source and spatially averaged DOAS instruments confirms the presence of hot-spots of IO caused by an inhomogeneous distribution of macroalgae. The co-incident, point source measurement of IO and ultra fine particles (2.5 nm≥d≥10 nm) displayed a strong correlation, providing evidence that IO is involved in the production pathway of ultra fine particles at coastal locations. Finally, a modelling study shows that high IO concentrations which are likely to be produced in a macrolagae rich environment can significantly perturb the concentrations of OH and HO[subscript x] radicals. The effect of IO on HO[subscript x] is reduced as NO[subscript x] concentrations increase