Spin-Dependent Transport in Fe/GaAs(100)/Fe Vertical Spin-Valves

The integration of magnetic materials with semiconductors will lead to the development of the next spintronics devices such as spin field effect transistor (SFET), which is capable of both data storage and processing. While the fabrication and transport studies of lateral SFET have attracted greatly attentions, there are only few studies of vertical devices, which may offer the opportunity for the future three-dimensional integration. Here, we provide evidence of two-terminal electrical spin injection and detection in Fe/GaAs/Fe vertical spin-valves (SVs) with the GaAs layer of 50 nanometers thick and top and bottom Fe electrodes deposited by molecular beam epitaxy. The spin-valve effect, which corresponds to the individual switching of the top and bottom Fe layers, is bias dependent and observed up to 20 K. We propose that the strongly bias-and temperature-dependent MR is associated with spin transport at the interfacial Fe/GaAs Schottky contacts and in the GaAs membranes, where balance between the barrier profiles as well as the dwell time to spin lifetime ratio are crucial factors for determining the device operations. The demonstration of the fabrication and spin injection in the vertical SV with a semiconductor interlayer is expected to open a new avenue in exploring the SFET

The C-Terminal Domain of the Novel Essential Protein Gcp Is Critical for Interaction with Another Essential Protein YeaZ of Staphylococcus aureus

Previous studies have demonstrated that the novel protein Gcp is essential for the viability of various bacterial species including Staphylococcus aureus; however, the reason why it is required for bacterial growth remains unclear. In order to explore the potential mechanisms of this essentiality, we performed RT-PCR analysis and revealed that the gcp gene (sa1854) was co-transcribed with sa1855, yeaZ (sa1856) and sa1857 genes, indicating these genes are located in the same operon. Furthermore, we demonstrated that Gcp interacts with YeaZ using a yeast two-hybrid (Y2H) system and in vitro pull down assays. To characterize the Gcp-YeaZ interaction, we performed alanine scanning mutagenesis on the residues of C-terminal segment of Gcp. We found that the mutations of the C-terminal Y317-F322 region abolished the interaction of Gcp and YeaZ, and the mutations of the D324-N329 and S332-Y336 regions alleviated Gcp binding to YeaZ. More importantly, we demonstrated that these key regions of Gcp are also necessary for the bacterial survival since these mutated Gcp could not complement the depletion of endogenous Gcp. Taken together, our data suggest that the interaction of Gcp and YeaZ may contribute to the essentiality of Gcp for S. aureus survival. Our findings provide new insights into the potential mechanisms and biological functions of this novel essential protein

Bradyrhizobium elkanii nod regulon: insights through genomic analysis

Abstract A successful symbiotic relationship between soybean [Glycine max (L.) Merr.] and Bradyrhizobium species requires expression of the bacterial structural nod genes that encode for the synthesis of lipochitooligosaccharide nodulation signal molecules, known as Nod factors (NFs). Bradyrhizobium diazoefficiens USDA 110 possesses a wide nodulation gene repertoire that allows NF assembly and modification, with transcription of the nodYABCSUIJnolMNOnodZ operon depending upon specific activators, i.e., products of regulatory nod genes that are responsive to signaling molecules such as flavonoid compounds exuded by host plant roots. Central to this regulatory circuit of nod gene expression are NodD proteins, members of the LysR-type regulator family. In this study, publicly available Bradyrhizobium elkanii sequenced genomes were compared with the closely related B. diazoefficiens USDA 110 reference genome to determine the similarities between those genomes, especially with regards to the nod operon and nod regulon. Bioinformatics analyses revealed a correlation between functional mechanisms and key elements that play an essential role in the regulation of nod gene expression. These analyses also revealed new genomic features that had not been clearly explored before, some of which were unique for some B. elkanii genomes

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe

Mobile Applications and Wearables for Chronic Respiratory Disease Monitoring

Mobile health (mHealth) has tremendous potential to benefit patients, providers, and the entire healthcare system. Benefits for patients to adopt mHealth include more effective access to health providers, reduced costs of care, and better health control. For physicians and the healthcare system, reasons to embrace mHealth are enhanced health outcomes, facilitated access to patients for care, and decreased time required for administrative tasks. Currently, some mobile apps and wearables dedicated to respiratory health provide medical education and messaging services, enable diary logs, aid with disease self-management, and include educational games. Major challenges for mHealth to be widely adopted include lack of studies demonstrating effectiveness, limited access to technology by all patients, decreased adoption over time, high costs, and data privacy concerns

Predicting predatory impact of juvenile invasive lionfish (Pterois volitans) on a crustacean prey using functional response analysis: effects of temperature, habitat complexity and light regimes

The ecological implications of biotic interactions, such as predator-prey relationships, are often context-dependent. Comparative functional responses analysis can be used under different abiotic contexts to improve understanding and prediction of the ecological impact of invasive species. Pterois volitans (Lionfish) [Linnaeus 1758] is an established invasive species in the Caribbean and Gulf of Mexico, with a more recent invasion into the Mediterranean. Lionfish are generalist predators that impact a wide range of commercial and non-commercial species. Functional response analysis was employed to quantify interaction strength between lionfish and a generic prey species, the shrimp (Paleomonetes varians) [Leach 1814], under the contexts of differing temperature, habitat complexity and light wavelength. Lionfish have prey population destabilising Type II functional responses under all contexts examined. Significantly more prey were consumed at 26 °C than at 22 °C. Habitat complexity did not significantly alter the functional response parameters. Significantly more prey were consumed under white light and blue light than under red light. Attack rate was significantly higher under white light than under blue or red light. Light wavelength did not significantly change handling times. The impacts on prey populations through feeding rates may increase with concomitant temperature increase. As attack rates are very high at low habitat complexity this may elucidate the cause of high impact upon degraded reef ecosystems with low-density prey populations, although there was little protection conferred through habitat complexity. Only red light (i.e. dark) afforded any reduction in predation pressure. Management initiatives should account for these environmental factors when planning mitigation and prevention strategies

Emergency Determination of Decision-making Capacity: Balancing Autonomy and Beneficence in the Emergency Department

The determination of decision-making capacity (DMC) is an essential component of securing voluntary informed consent, for either treatment or refusal of care. Decision-making capacity should be determined on some level during each patient encounter. Decision-making capacity includes the ability to receive, process, and understand information, the ability to deliberate, the ability to make choices, and the ability to communicate those preferences. For patients in whom DMC may be uncertain, a more explicit approach to determination of DMC is recommended. However, DMC determination must neither compromise patient safety nor delay needed care. When DMC determination is challenging, or when the ramifications of a decision are serious, the assistance of a third party (such as a surrogate, a consultant, or another clinician) may be valuable in discerning the most appropriate action. In addition to the obvious clinical utility of DMC assessment, the steps taken in the very establishment of DMC may promote patient trust, professionalism, and humanistic clinical practice. While DMC may be conditional, the compassion and respect we have for our patients must be unconditional

Validation of the revised IPSS at transplant in patients with myelodysplastic syndrome/transformed acute myelogenous leukemia receiving allogeneic stem cell transplantation : a retrospective analysis of the EBMT chronic malignancies working party

The International Prognostic Scoring System has been revised (IPSS-R) to predict prognosis of patients with myelodysplastic syndromes at diagnosis. To validate the use of the IPSS-R assessed before transplant rather than at diagnosis we performed a retrospective analysis of the EBMT database. A total of 579 patients had sufficient information available to calculate IPSS-R at transplant. Median overall survival (OS) from transplant was significantly different according to IPSS-R: very low 23.6 months, low 55.0 months, intermediate 19.7 months, high 13.5 months, very high 7.8 months (P <0.001). In a multivariate Cox model the following parameters were significant risk factors for OS: IPSS-R, graft source, age and prior treatment. Median relapse free survival also showed significant differences according to IPSS-R: very low: 23.6 months, low: 24.8 months, intermediate 10.6 months, high 7.9 months, very high 5.5 months (P <0.001). Multivariate risk factors for relapse-free survival (RFS) were: IPSS-R, reduced intensity conditioning, graft source and prior treatment. A trend for an increased relapse incidence was noted for very high risk IPSS-R. We conclude that the IPSS-R at transplant is a useful prognostic score for predicting OS and RFS after transplantation, capturing both disease evolution and response to prior treatment before transplant.Peer reviewe

Testing for the principal’s monopsony power in agency contracts

Oligopsony, Principal–agent model, Production contracts, C33, D43, J41, J43, L13,