Possession of Child Exploitation Material in Computer Temporary Internet Cache

When considering the possession of child exploitation material U.S. and German courts have the same focus, but slightly different interpretations. This slight difference in interpretation could mean that in one country a defendant will be found guilty of possession while in the other country he or she could be found not guilty. In this work we examine the standards courts in Germany and the United States have used to combat child pornography, and analyze the approaches specifically related to viewing and possession of CEM. A uniform solution is suggested that criminalizes “knowing access with the intention to view” as a method to handle challenges related to the definition of possession

Anti-Forensic Trace Detection in Digital Forensic Triage Investigations

Anti-forensics, whether intentionally to disrupt investigations or simply an effort to make a computer system run better, is becoming of increasing concern to digital investigators. This work attempts to assess the problem of anti-forensics techniques commonly deployed in South Korea. Based on identified challenges, a method of signature-based anti-forensic trace detection is proposed for triage purposes that will assist investigators in quickly making decisions about the suspect digital devices before conducting a full investigation. Finally, a prototype anti-forensic trace detection system is given to demonstrate the practicality of the proposed method

Measurement crosstalk between two phase qubits coupled by a coplanar waveguide

We analyze the measurement crosstalk between two flux-biased phase qubits coupled by a resonant coplanar waveguide cavity. After the first qubit is measured, the superconducting phase can undergo damped oscillations resulting in an a.c. voltage that produces a frequency chirped noise signal whose frequency crosses that of the cavity. We show experimentally that the coplanar waveguide cavity acts as a bandpass filter that can significantly reduce the crosstalk signal seen by the second qubit when its frequency is far from the cavity's resonant frequency. We present a simple classical description of the qubit behavior that agrees well with the experimental data. These results suggest that measurement crosstalk between superconducting phase qubits can be reduced by use of linear or possibly nonlinear resonant cavities as coupling elements.Comment: 4 pages, 3 figure

Vascular mitochondrial respiratory function: the impact of advancing age

Little is known about vascular mitochondrial respiratory function and the impact of age. Therefore, skeletal muscle feed arteries were harvested from young (33 ± 7 yr, n = 10), middle-aged (54 ± 5 yr, n = 10), and old (70 ± 7 yr, n = 10) subjects, and mitochondrial respiration as well as citrate synthase (CS) activity were assessed. Complex I (CI) and complex I + II (CI+II) state 3 respiration were greater in young (CI: 10.4 ± 0.8 pmol·s−1·mg−1 and CI+II: 12.4 ± 0.8 pmol·s−1·mg−1, P \u3c 0.05) than middle-aged (CI: 7 ± 0.6 pmol·s−1·mg−1 and CI+II: 8.3 ± 0.5 pmol·s−1·mg−1) and old (CI: 7.2 ± 0.4 pmol·s−1·mg−1 and CI+II: 7.6 ± 0.5 pmol·s−1·mg−1) subjects and, as in the case of complex II (CII) state 3 respiration, were inversely correlated with age [r = −0.56 (CI), r = −0.7 (CI+II), and r = 0.4 (CII), P \u3c 0.05]. In contrast, state 4 respiration and mitochondria-specific superoxide levels were not different across groups. The respiratory control ratio was greater in young (2.2 ± 0.2, P \u3c 0.05) than middle-aged and old (1.4 ± 0.1 and 1.1 ± 0.1, respectively) subjects and inversely correlated with age (r = −0.71, P \u3c 0.05). As CS activity was inversely correlated with age (r = −0.54, P \u3c 0.05), when normalized for mitochondrial content, the age-related differences and relationships with state 3 respiration were ablated. In contrast, mitochondrion-specific state 4 respiration was now lower in young (15 ± 1.4 pmol·s−1·mg−1·U CS−1, P \u3c 0.05) than middle-aged and old (23.4 ± 3.6 and 27.9 ± 3.4 pmol·s−1·mg−1·U CS−1, respectively) subjects and correlated with age (r = 0.46, P \u3c 0.05). Similarly, superoxide/CS levels were lower in young (0.07 ± 0.01) than old (0.19 ± 0.41) subjects and correlated with age (r = 0.44, P \u3c 0.05). Therefore, with aging, vascular mitochondrial respiratory function declines, predominantly as a consequence of falling mitochondrial content. However, per mitochondrion, aging likely results in greater mitochondrion-derived oxidative stress, which may contribute to age-related vascular dysfunction

Vasodilatory and vascular mitochondrial respiratory function with advancing age: evidence of a free radically mediated link in the human vasculature

Recognizing the age-related decline in skeletal muscle feed artery (SMFA) vasodilatory function, this study examined the link between vasodilatory and mitochondrial respiratory function in the human vasculature. Twenty-four SMFAs were harvested from young (35 ± 6 yr, n = 9) and old (71 ± 9 yr, n = 15) subjects. Vasodilation in SMFAs was assessed, by pressure myography, in response to flow-induced shear stress, acetylcholine (ACh), and sodium nitroprusside (SNP) while mitochondrial respiration was measured, by respirometry, in permeabilized SMFAs. Endothelium-dependent vasodilation was significantly attenuated in the old, induced by both flow (young: 92 ± 3, old: 45 ± 4%) and ACh (young: 92 ± 3, old: 54 ± 5%), with no significant difference in endothelium-independent vasodilation. Complex I and I + II state 3 respiration was significantly lower in the old (CI young: 10.1 ± 0.8, old: 7.0 ± 0.4 pmol·s−1·mg−1; CI + II young: 12.3 ± 0.6, old: 7.6 ± 0.4 pmol·s−1·mg−1). The respiratory control ratio (RCR) was also significantly attenuated in the old (young: 2.2 ± 0.1, old: 1.1 ± 0.1). Furthermore, state 3 (CI + II) and 4 respiration, as well as RCR, were significantly correlated (r = 0.49–0.86) with endothelium-dependent, but not endothelium-independent, function. Finally, the direct intervention with mitochondrial-targeted antioxidant (MitoQ) significantly improved endothelium-dependent vasodilation in the old but not in the young. Thus, the age-related decline in vasodilatory function is linked to attenuated vascular mitochondrial respiratory function, likely by augmented free radicals

Impact of sequencing depth in ChIP-seq experiments

In a chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) experiment, an important consideration in experimental design is the minimum number of sequenced reads required to obtain statistically significant results. We present an extensive evaluation of the impact of sequencing depth on identification of enriched regions for key histone modifications (H3K4me3, H3K36me3, H3K27me3 and H3K9me2/me3) using deep-sequenced datasets in human and fly. We propose to define sufficient sequencing depth as the number of reads at which detected enrichment regions increase <1% for an additional million reads. Although the required depth depends on the nature of the mark and the state of the cell in each experiment, we observe that sufficient depth is often reached at <20 million reads for fly. For human, there are no clear saturation points for the examined datasets, but our analysis suggests 40–50 million reads as a practical minimum for most marks. We also devise a mathematical model to estimate the sufficient depth and total genomic coverage of a mark. Lastly, we find that the five algorithms tested do not agree well for broad enrichment profiles, especially at lower depths. Our findings suggest that sufficient sequencing depth and an appropriate peak-calling algorithm are essential for ensuring robustness of conclusions derived from ChIP-seq data

Targeted Discovery of Glycoside Hydrolases from a Switchgrass-Adapted Compost Community

Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Small-subunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence data from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, ∼10% were putative cellulases mostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50°C and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme

Analysis of Neptune's 2017 Bright Equatorial Storm

We report the discovery of a large ($\sim$8500 km diameter) infrared-bright storm at Neptune's equator in June 2017. We tracked the storm over a period of 7 months with high-cadence infrared snapshot imaging, carried out on 14 nights at the 10 meter Keck II telescope and 17 nights at the Shane 120 inch reflector at Lick Observatory. The cloud feature was larger and more persistent than any equatorial clouds seen before on Neptune, remaining intermittently active from at least 10 June to 31 December 2017. Our Keck and Lick observations were augmented by very high-cadence images from the amateur community, which permitted the determination of accurate drift rates for the cloud feature. Its zonal drift speed was variable from 10 June to at least 25 July, but remained a constant $237.4 \pm 0.2$ m s$^{-1}$ from 30 September until at least 15 November. The pressure of the cloud top was determined from radiative transfer calculations to be 0.3-0.6 bar; this value remained constant over the course of the observations. Multiple cloud break-up events, in which a bright cloud band wrapped around Neptune's equator, were observed over the course of our observations. No "dark spot" vortices were seen near the equator in HST imaging on 6 and 7 October. The size and pressure of the storm are consistent with moist convection or a planetary-scale wave as the energy source of convective upwelling, but more modeling is required to determine the driver of this equatorial disturbance as well as the triggers for and dynamics of the observed cloud break-up events.Comment: 42 pages, 14 figures, 6 tables; Accepted to Icaru