Strongly birefringent cut-wire pair structure as negative index wave plates at THz frequencies

We report a new approach for the design and fabrication of thin wave plates with high transmission in the terahertz (THz) regime. The wave plates are based on strongly birefringent cut-wire pair metamaterials that exhibit refractive indices of opposite signs for two orthogonal polarization components of an incident wave. As specific examples, we fabricated and investigated a quarter- and a half-wave plate that revealed a peak intensity transmittance of 74% and 58% at 1.34 THz and 1.3 THz, respectively. Furthermore, the half wave plate displayed a maximum figure of merit (FOM) of 23 at 1.3 THz where the refractive index was -1.7. This corresponds to one of the highest FOMs reported at THz frequencies so far. The presented results evidence that negative index materials enter an application stage in terms of optical components for the THz technology.Comment: 4 pages, 3 figures, submitted to Appl. Phys. Let

Cardiovascular Disease and Post Traumatic Stress Disorder in Adults Exposed to the Terrorist Attacks on the World Trade Center

Following events of terrorism communities and individuals are subject to the cumbersome responsibilities associated with rescue and recovery efforts. In addition to the loss of life and direct injuries sustained during the incident, long term health outcomes among the exposed population are often seen. Both physical and mental health can be affected as a result of the exposure, and some outcomes do not immediately present themselves. The population exposed to the September 11, 2001 terrorist attacks on the World Trade Center in New York City is no different, and the World Trade Center Health Registries database has been established by the New York Department of Health in order to more effectively monitor the population for long term adverse outcomes. This analysis uses the de-identified data within the World Trade Center Health Registry to examine the relationship between Post Traumatic Stress Disorder (PTSD) and cardiovascular disease as well as to identify risk factors that placed an individual at increased risk of developing PTSD. It was found that female sex, age within the range of 25-44 years, African American persons, Hispanic/Latino persons, those with lower levels of education completed, and those who are widowed, divorced or separated were at increased risk of developing PTSD. Among the exposed population those who were identified as having probable PTSD there was an increased risk of myocardial infarction, cerebrovascular accident, hypertension, heart disease and diabetes mellitus type II developing or occurring after September 11th when compared to the exposed population that did not develop probable PTSD. Mental illness, especially PTSD, is debilitating in its own right and the increased impact of the morbidity and mortality of cardiovascular disease can only act to increase the barrier to the recovery of a population following disaster. By identifying those at increased risk of developing PTSD and creating interventional programs that prevent PTSD, the adverse outcomes associated with cardiovascular disease can be avoided

Do not attempt resuscitation : the importance of consensual decisions

Aims: To describe the involvement and input of physicians and nurses in cardiopulmonary resuscitation (cpr / do not attempt resuscitation (dnar) decisions; to analyse decision patterns; and understand the practical implications. Design: A qualitative grounded theory study using one-time open-ended interviews with 40 volunteer physicians and 52 nurses drawn from acute care wards with mixes of heterogeneous cases in seven different hospitals in German-speaking Switzerland. Results: Establishing dnar orders in the best interests of patients was described as a challenging task requiring the leadership of senior physicians and nurses. Implicit decisions in favour of cpr predominated at the beginning of hospitalisation; depending on the context, they were relieved/superseded by explicit dnar decisions. Explicit decisions were the result of hierarchical medical expertise, of multilateral interdisciplinary expertise, of patient autonomy and/or of negotiated patient autonomy. Each type of decision, implicit or explicit, potentially represented a team consensus. Non-consensual decisions were prone to precipitate personal or team conflicts, and, occasionally, led to non-compliance. Conclusion: Establishing dnar orders is a demanding task. Reaching a consensus is of crucial importance in guaranteeing teamwork and good patient care. Communication and negotiation skills, professional and personal life experience and empathy for patients and colleagues are pivotal. Therefore, leadership by experienced senior physicians and nurses is needed and great efforts should be made with regard to multidisciplinary education

Detailed analysis of radiation data from the Gemini 4 and Gemini 7 proton-electron spectrometer experiments Final report, 13 Jun. 1967 - 30 Dec. 1968

Detailed analysis of radiation data from Gemini 4 and 7 proton-electron spectrometer experiment

Reasons why people in Switzerland seek assisted suicide : the view of patients and physicians

Background: Assisted suicide is permitted in Switzerland provided that assistance is not motivated by selfish reasons. Suicides are commonly performed with the assistance of right-to-die organisations and the use of a lethal dose of barbiturates prescribed by a participating physician. We examined the reasons physicians provided for writing the prescription and the reasons patients gave for requesting assistance in dying. Methods: We analysed all reported cases of assisted suicide that were facilitated by right-to-die organisations between 2001 and 2004 in the city of Zurich, and for which both the medical report and the optional letter written by the decedent providing information on their reasons for seeking assistance in suicide (N = 165). Results: The reasons most often reported by physicians (ph), as well as persons who sought help (p), were: pain (ph: 56% of all assisted suicides, p: 58%), need for long-term care (ph: 37%, p: 39%), neurological symptoms (ph: 35%, p: 32%), immobility (ph: 23%, p: 30%) and dyspnoea (ph: 23%, p: 23%). Control of circumstances over death (ph: 12%, p: 39%); loss of dignity (ph: 6%, p: 38%); weakness (ph: 13%, p: 26%); less able to engage in activities that make life enjoyable (ph: 6%, p: 18%); and insomnia and loss of concentration (ph: 4%, p: 13%) were significantly more often mentioned by decedents than by physicians. Conclusions: Both prescribing physicians and;patients provided with assistance to die quite often mentioned pain and other concerns, many of which were objectively assessable and related to unbearable suffering or unreasonable disability. Concerns referable to autonomy and individual judgement were more often noted by people seeking help than by the prescribing physicians

Mechanism of DNA recognition by the restriction enzyme EcoRV.

EcoRV, a restriction enzyme in Escherichia coli, destroys invading foreign DNA by cleaving it at the center step of a GATATC sequence. In the EcoRV-cognate DNA crystallographic complex, a sharp kink of 50 degrees has been found at the center base-pair step (TA). Here, we examine the interplay between the intrinsic propensity of the cognate sequence to kink and the induction by the enzyme by performing all-atom molecular dynamics simulations of EcoRV unbound and interacting with three DNA sequences: the cognate sequence, GATATC (TA); the non-cognate sequence, GAATTC (AT); and with the cognate sequence methylated on the first adenine GA(CH(3))TATC (TA-CH(3)). In the unbound EcoRV, the cleft between the two C-terminal subdomains is found to be open. Binding to AT narrows the cleft and forms a partially bound state. However, the intrinsic bending propensity of AT is insufficient to allow tight binding. In contrast, the cognate TA sequence is easier to bend, allowing specific, high-occupancy hydrogen bonds to form in the complex. The absence of cleavage for this methylated sequence is found to arise from the loss of specific hydrogen bonds between the first adenine of the recognition sequence and Asn185. On the basis of the results, we suggest amore » three-step recognition mechanism. In the first step, EcoRV, in an open conformation, binds to the DNA at a random sequence and slides along it. In the second step, when the two outer base pairs, GAxxTC, are recognized, the R loops of the protein become more ordered, forming strong hydrogen-bonding interactions, resulting in a partially bound EcoRV-DNA complex. In the third step, the flexibility of the center base pair is probed, and in the case of the full cognate sequence the DNA bends, the complex strengthens and the protein and DNA interact more closely, allowing cleavage.« les

Disseminated Invasive Aspergillosis with Cerebral Involvement Successfully Treated with Caspofungin and Voriconazole

We describe a case of cerebral aspergillosis which was successfully treated with a combination of caspofungin and voriconazole. The patient remains in remission 18 months after stopping antifungal treatment. We discuss primary and salvage therapy of invasive aspergillosis with focus on cerebral involvement. Since historical data showed a fatal outcome in most cases, amphotericin B does not cross the blood brain barrier while voriconazole does, we chose a combination of voriconazole plus caspofungin as primary therap

Drosophila RISC Component VIG and Its Homolog Vig2 Impact Heterochromatin Formation

Heterochromatin formation plays an important role in gene regulation and the maintenance of genome integrity. Here we present results from a study of the D. melanogaster gene vig, encoding an RNAi complex component and its homolog vig2 (CG11844) that support their involvement in heterochromatin formation and/or maintenance. Protein null mutations vigEP812 and vig2PL470 act as modifiers of Position Effect Variegation (PEV). VIG and Vig2 are present in polytene chromosomes and partially overlap with HP1. Quantitative immunoblots show depletion of HP1 and HP2 (large isoform) in isolated nuclei from the vigEP812 mutant. The vig2PL470 mutant strain demonstrates a decreased level of H3K9me2. Pull-down experiments using antibodies specific to HP1 recovered both VIG and Vig2. The association between HP1 and both VIG and Vig2 proteins depends on an RNA component. The above data and the developmental profiles of the two genes suggest that Vig2 may be involved in heterochromatin targeting and establishment early in development, while VIG may have a role in stabilizing HP1/HP2 chromatin binding during later stages

Improved quality of online education using prioritized multi-agent reinforcement learning for video traffic scheduling

The recent global pandemic has transformed the way education is delivered, increasing the importance of videobased online learning. However, this puts a significant pressure on the underlying communication networks and the limited available bandwidth needs to be intelligently allocated to support a much higher transmission load, including video-based services. In this context, this paper proposes a Machine Learning (ML)-based solution that dynamically prioritizes content viewers with heterogeneous video services to increase their Quality of Service (QoS) and perceived Quality of Experience (QoE). The proposed approach makes use of the novel Prioritized Multi- Agent Reinforcement Learning solution (PriMARL) to decide the prioritization order of the video-based services based on networking conditions. However, the performance in terms of QoS and QoE provisioning to learners with different profiles and networking conditions depends on the type of scheduler employed in the frequency domain to conduct the scheduling and the radio resource allocation. To decide the best approach to be followed, we employ the proposed PriMARL solution with different types of scheduling rules and compare them with other state-of-theart solutions in terms of throughput, delay, packet loss, Peak Signal-to-Noise Ratio (PSNR), and Mean Opinion Score (MOS) for different traffic loads and characteristics. We show that the proposed solution achieves the best user QoE results