In-gap features in superconducting LaAlO3_3-SrTiO3_3 interfaces observed by tunneling spectroscopy

We identified quasiparticle states at well-defined energies inside the superconducting gap of the electron system at the LaAlO$_3$-SrTiO$_3$ interface using tunneling spectroscopy. The states are found only in a number of samples and depend upon the thermal-cycling history of the samples. The states consist of a peak at zero energy and other peaks at finite energies, symmetrically placed around zero energy. These peaks disappear, together with the superconducting gap, with increasing temperature and magnetic field. We discuss the likelihood of various physical mechanisms that are known to cause in-gap states in superconductors and conclude that none of these mechanisms can easily explain the results. The conceivable scenarios are the formation of Majorana bound states, Andreev bound states, or the presence of an odd-frequency spin triplet component in the superconducting order parameter.Comment: 11 pages, 5 figure

Improving the effectiveness of web application vulnerability scanning

Using web application vulnerability scanners is very appealing as they promise to detect vulnerabilities with minimal configuration effort. However, using them effectively in practice is often difficult. Two of the main reasons for this are limitations with respect to crawling capabilities and problems to perform authenticated scans. In this paper, we present JARVIS, which provides technical solutions that can be applied to a wide range of vulnerability scanners to overcome these limitations and to significantly improve their effectiveness. To evaluate JARVIS, we applied it to five freely available vulnerability scanners and tested the vulnerability detection performance in the context of seven deliberately insecure web applications. A first general evaluation showed that by using the scanners with JARVIS, the number of detected vulnerabilities can be increased by more than 100% on average compared to using the scanners without JARVIS. A significant fraction of the additionally detected vulnerabilities is security-critical, which means that JARVIS provides a true security benefit. A second, more detailed evaluation focusing on SQL injection and cross-site scripting vulnerabilities revealed that JARVIS improves the vulnerability detection performance of the scanners by 167% on average, without increasing the fraction of reported false positives. This demonstrates that JARVIS not only manages to greatly improve the vulnerability detection rate of these two highly security-critical types of vulnerabilities, but also that JARVIS is very usable in practice by keeping the false positives reasonably low. Finally, as the configuration effort to use JARVIS is small and as the configuration is scanner- independent, JARVIS also supports using multiple scanners in parallel in an efficient way. In an additional evaluation, we therefore analyzed the potential and limitations of using multiple scanners in parallel. This revealed that using multiple scanners in a reasonable way is indeed beneficial as it further increases the number of detected vulnerabilities without a significant negative impact on the reported false positives

14C contamination testing in natural abundance laboratories: a new preparation method using wet chemical oxidation and some experiences

Substances enriched with radiocarbon can easily contaminate samples and laboratories used for natural abundance measurements. We have developed a new method using wet chemical oxidation for swabbing laboratories and equipment to test for 14C contamination. Here, we report the findings of 18 months’ work and more than 800 tests covering studies at multiple locations. Evidence of past and current use of enriched 14C was found at all but one location and a program of testing and communication was used to mitigate its effects. Remediation was attempted with mixed success and depended on the complexity and level of the contamination. We describe four cases from different situations

Characterization of protein-interaction networks in tumors

<p>Abstract</p> <p>Background</p> <p>Analyzing differential-gene-expression data in the context of protein-interaction networks (PINs) yields information on the functional cellular status. PINs can be formally represented as graphs, and approximating PINs as undirected graphs allows the network properties to be characterized using well-established graph measures.</p> <p>This paper outlines features of PINs derived from 29 studies on differential gene expression in cancer. For each study the number of differentially regulated genes was determined and used as a basis for PIN construction utilizing the Online Predicted Human Interaction Database.</p> <p>Results</p> <p>Graph measures calculated for the largest subgraph of a PIN for a given differential-gene-expression data set comprised properties reflecting the size, distribution, biological relevance, density, modularity, and cycles. The values of a distinct set of graph measures, namely <it>Closeness Centrality</it>, <it>Graph Diameter</it>, <it>Index of Aggregation</it>, <it>Assortative Mixing Coefficient</it>, <it>Connectivity</it>, <it>Sum of the Wiener Number</it>, <it>modified Vertex Distance Number</it>, and <it>Eigenvalues </it>differed clearly between PINs derived on the basis of differential gene expression data sets characterizing malignant tissue and PINs derived on the basis of randomly selected protein lists.</p> <p>Conclusion</p> <p>Cancer PINs representing differentially regulated genes are larger than those of randomly selected protein lists, indicating functional dependencies among protein lists that can be identified on the basis of transcriptomics experiments. However, the prevalence of hub proteins was not increased in the presence of cancer. Interpretation of such graphs in the context of robustness may yield novel therapies based on synthetic lethality that are more effective than focusing on single-action drugs for cancer treatment.</p

Gate-tunable kinetic inductance parametric amplifier

Superconducting parametric amplifiers play a crucial role in the preparation and readout of quantum states at microwave frequencies, enabling high-fidelity measurements of superconducting qubits. Most existing implementations of these amplifiers rely on the nonlinearity from Josephson junctions, superconducting quantum interference devices or disordered superconductors. Additionally, frequency tunability arises typically from either flux or current biasing. In contrast, semiconductor-based parametric amplifiers are tunable by local electric fields, which impose a smaller thermal load on the cryogenic setup than current and flux biasing and lead to vanishing crosstalk to other on-chip quantum systems. In this work, we present a gate-tunable parametric amplifier that operates without Josephson junctions, utilizing a proximitized semiconducting nanowire. This design achieves near-quantum-limited performance, featuring more than 20 dB gain and a 30 MHz gain-bandwidth product. The absence of Josephson junctions allows for advantages, including substantial saturation powers of -120dBm, magnetic field compatibility up to 500 mT and frequency tunability over a range of 15 MHz. Our realization of a parametric amplifier supplements efforts towards gate-controlled superconducting electronics, further advancing the abilities for high-performing quantum measurements of semiconductor-based and superconducting quantum devices.Comment: 12 pages, 11 figure

Does a single session of high-intensity interval training provoke a transient elevated risk of falling in seniors and adults?

Balance and strength training can reduce seniors' fall risk up to 50%. Available evidence suggests that acute bouts of neuromuscular and endurance exercise deteriorate postural control. High-intensity endurance training has been successfully applied in different populations. Thus, it seemed valuable to examine the acute effects of high-intensity interval training (HIIT) on neuromuscular performance in seniors and young adults.; The acute impact of a HIIT session on balance performance and muscle activity after exercise cessation and during post-exercise recovery was examined in young and old adults. We intended to investigate whether a transient exercise-induced fall-risk may occur in both groups.; 20 healthy seniors (age 70 (SD 4) years) and young adults (age 27 (SD 3) years) were examined on 3 days. After exhaustive ramp-like treadmill testing in order to determine maximal heart rate (HRmax) on the first day, either a 4 × 4 min HIIT at 90% of HRmax or a control condition (CON) was randomly performed on the second and third day, respectively. Balance performance (postural sway) was assessed during single limb stance with open eyes (SLEO) and double limb stance with closed eyes (DLEC). EMG was recorded for the soleus (SOL), anterior tibialis (TIB), gastrocnemius (GM) and peroneus longus (PL) muscles at the dominant leg. All measures were collected before, immediately as well as 10, 30 and 45 min after HIIT and CON, respectively.; Compared to CON, HIIT induced significant increases of postural sway immediately after exercise cessation during SLEO in both groups (adults: p &lt; 0.001, Δ = +25% sway; seniors: p = 0.007, Δ = +15% sway). Increased sway during DLEC was only found for seniors immediately and 10 min after HIIT (post: p = 0.003, Δ = +14% sway, 10 min post: p = 0.004, Δ = +18% sway). Muscle activity was increased during SLEO for TIB until 10 min post in seniors (0.008 &lt; p &lt; 0.03) and immediately after HIIT in adults (p &lt; 0.001).; HIIT training may cause an acute 'open-fall-window' with a transient impairment of balance performance for at least 10 min after exercise cessation in both groups. Occluded vision in seniors seems to prolong this period up to 30 min. Thus, the advantage of HIIT with regard to time efficiency seems debatable when considering transient HIIT-induced impairments of neuromuscular function

Exploiting the potential of web application vulnerability scanning

Using automated web application vulnerability scanners so that they truly live up to their potential is difficult. Two of the main reasons for this are limitations with respect to crawling capabilities and problems to perform authenticated scans. In this paper, we present JARVIS, which provides technical solutions that can be applied to a wide range of vulnerability scanners to overcome these limitations. Our evaluation shows that by using JARVIS, the vulnerability detection performance of five freely available scanners can be improved by more than 100% compared to using them in their basic configuration. As the configuration effort to use JARVIS is small and the configurations are scanner-independent, JARVIS also allows to use multiple scanners in parallel in an efficient way. In an additional evaluation, we therefore analyzed the potential and limitations of using multiple scanners in parallel. This revealed that using multiple scanners in a reasonable way is indeed beneficial as it increases the number of detected vulnerabilities without a significant negative impact on the reported false positives

Balance and gait performance after maximal and submaximal endurance exercise in seniors: is there a higher fall-risk?

Impaired balance and gait performance increase fall-risk in seniors. Acute effects of different exercise bouts on gait and balance were not yet addressed. Therefore, 19 healthy seniors (10 women, 9 men, age: 64.6±3.2years) were examined on 3days. After exhaustive treadmill testing, participants randomly completed a 2-km treadmill walking test (76±8% VO2max) and a resting control condition. Standing balance performance (SBALP) was assessed by single limb-eyes opened (SLEO) and double limb-eyes closed (DLEC) stance. Gait parameters were collected at comfortable walking velocity. A condition×time interaction of center of pressure path length (COPpath) was observed for both balance tasks (p<0.001). Small (Cohen's d=0.42, p=0.05) and large (d=1.04, p<0.001) COPpath increases were found after 2-km and maximal exercise during DLEC. Regarding SLEO, slightly increased COPpath occurred after 2-km walking (d=0.29, p=0.65) and large increases after exhaustive exercise (d=1.24, p<0.001). No significant differences were found for gait parameters. Alterations of SBALP after exhaustive exercise might lead to higher fall-risk in seniors. Balance changes upon 2-km testing might be of minor relevance. Gait is not affected during single task walking at given velocitie