The Design and Validation of the Quantum Mechanics Conceptual Survey

The Quantum Mechanics Conceptual Survey (QMCS) is a 12-question survey of students' conceptual understanding of quantum mechanics. It is intended to be used to measure the relative effectiveness of different instructional methods in modern physics courses. In this paper we describe the design and validation of the survey, a process that included observations of students, a review of previous literature and textbooks and syllabi, faculty and student interviews, and statistical analysis. We also discuss issues in the development of specific questions, which may be useful both for instructors who wish to use the QMCS in their classes and for researchers who wish to conduct further research of student understanding of quantum mechanics. The QMCS has been most thoroughly tested in, and is most appropriate for assessment of (as a posttest only), sophomore-level modern physics courses. We also describe testing with students in junior quantum courses and graduate quantum courses, from which we conclude that the QMCS may be appropriate for assessing junior quantum courses, but is not appropriate for assessing graduate courses. One surprising result of our faculty interviews is a lack of faculty consensus on what topics should be taught in modern physics, which has made designing a test that is valued by a majority of physics faculty more difficult than expected.Comment: Submitted to Physical Review Special Topics: Physics Education Researc

Enhancement of the in vivo circulation lifetime of l-α-distearoylphosphatidylcholine liposomes: importance of liposomal aggregation versus complement opsonization

AbstractIncorporation of N-(ω-carboxy)acylamido-phosphatidylethanolamines (-PEs) into large unilamellar vesicles (LUVs) of l-α-distearoylphosphatidylcholine (DSPC) was found to dramatically increase the in vivo liposomal circulation lifetime in rats, reaching a maximal effect at 10 mol.% of the total phospholipid. Neither pure DSPC liposomes nor those with the longest circulating derivative, N-glutaryl-dipalmitoylphosphatidylethanolamine (-DPPE), were found to significantly bind complement from serum. Therefore, the relatively short circulation time of pure DSPC liposomes did not appear to be related to greater complement opsonization leading to uptake by the reticuloendothelial system. However, N-(ω-carboxy)acylamido-PEs were particularly efficient inhibitors of a limited aggregation detected for pure DSPC liposomes. The aggregation tendency of DSPC liposomes incorporating various structural analogs of N-glutaryl-DPPE correlated inversely with the circulation lifetimes. Therefore, it is concluded that such PE derivatives enhance the circulation time by preventing liposomal aggregation and avoiding a poorly understood mechanism of clearance that is dependent on size but is independent of complement opsonization. At high concentrations of N-glutaryl-DPPE (above 10 mol.%), the liposomes exhibited strong complement opsonization and were cleared from circulation rapidly, as were other highly negatively charged liposomes. These data demonstrate that both the lack of opsonization and the lack of a tendency to aggregate are required for long circulation. Liposomal disaggregation via N-(ω-carboxy)acylamido-PEs yields a new class of large unilamellar DSPC liposomes with circulation lifetimes that are comparable to those of sterically stabilized liposomes

Life after ayahuasca : a qualitative analysis of the psychedelic integration experiences of 1630 ayahuasca drinkers from a global survey

Ayahuasca is an Amazonian psychoactive plant medicine being explored for its potential therapeutic uses in Western contexts. Preliminary studies link ayahuasca use with improvements across a range of mental health indicators, but studies have not yet explored qualitative aspects of the post-treatment process known in the psychedelic literature as “integration”. This includes how participants make sense of their ayahuasca experiences and minimise harm/maximise benefits after ayahuasca use. A global online survey, conducted between 2017 and 2019, collected responses from 1630 ayahuasca drinkers (50.4% male, mean age = 43 years) to an open-ended question about their integration experiences after consuming ayahuasca. Inductive codebook thematic analysis was used to identify themes in participants’ integration experiences. Participants described integration experiences in three main ways. First, was an overall appraisal of the integration experience (e.g., as easy, challenging, or long-term/ongoing). Second, was describing beneficial tools which facilitated integration (e.g., connecting with a like-minded community and ongoing practice of yoga, meditation, journaling, etc.). Third, was describing integration challenges (e.g., feeling disconnected, going back to “old life” with new understandings, etc.). These findings suggest that integrating ayahuasca experiences can be challenging and take considerable time, though working through integration challenges may facilitate positive growth. Findings also challenge the role of individual psychotherapy as the primary integration tool in Western psychedelic therapy, suggesting that communal and somatic elements may also be useful. An expanded definition of psychedelic integration is proposed which includes working with integration challenges and adjusting to life changes

AstroPix: novel monolithic active pixel silicon sensors for future gamma-ray telescopes

Space-based gamma-ray telescopes such as the Fermi Large Area Telescope have used single sided silicon strip detectors to track secondary charged particles produced by primary gamma-rays with high resolution. At the lower energies targeted by keV-MeV telescopes, two dimensional position information within a single detector is required for event reconstruction - especially in the Compton regime. This work describes the development of monolithic CMOS active pixel silicon sensors - AstroPix - as a novel technology for use in future gamma-ray telescopes. Based upon sensors (ATLASPix) designed for use in the ATLAS detector at the Large Hadron Collider, AstroPix has the potential to maintain high performance while reducing noise with low power consumption. This is achieved with the dual detection and readout capabilities in each CMOS pixel. The status of AstroPix development and testing, as well as outlook for future testing and application, will be presented

AstroPix: CMOS pixels in space

Space-based gamma-ray telescopes such as the Fermi Large Area Telescope have used single sided silicon strip detectors to measure the position of charged particles produced by incident gamma rays with high resolution. At energies in the Compton regime and below, two dimensional position information within a single detector is required. Double sided silicon strip detectors are one option; however, this technology is difficult to fabricate and large arrays are susceptible to noise. This work outlines the development and implementation of monolithic CMOS active pixel silicon sensors, AstroPix, for use in future gamma-ray telescopes. Based upon detectors designed using the HVCMOS process at the Karlsruhe Institute of Technology, AstroPix has the potential to maintain the high energy and angular resolution required of a medium-energy gamma- ray telescope while reducing noise with the dual detection-and-readout capabilities of a CMOS chip. The status of AstroPix development and testing as well as outlook for application in future telescopes is presented

Exploratory analysis of social cognition and neurocognition in individuals at clinical high risk for psychosis

Neurocognition and social cognition are separate but related constructs known to be impaired in schizophrenia. The aim of this study was to extend the current knowledge of the relationship between social cognition and neurocognition in individuals at clinical high risk (CHR) of developing psychosis by examining, in a large sample, the associations between a wide range of neurocognitive tasks and social cognition. Participants included 136 young people at CHR. Specific domains within neurocognition and social cognition were compared using Spearman correlations. Results showed that poor theory of mind correlated with low ratings on a wide range of neurocognitive tasks. Facial affect was more often associated with low ratings on spatial working memory and attention. These results supports a link between neurocognition and social cognition even at this early stage of potential psychosis, with indication that poorer performance on social cognition may be associated with deficits in attention and working memory. Understanding these early associations may have implications for early intervention

A transient homotypic interaction model for the influenza A virus NS1 protein effector domain

Influenza A virus NS1 protein is a multifunctional virulence factor consisting of an RNA binding domain (RBD), a short linker, an effector domain (ED), and a C-terminal 'tail'. Although poorly understood, NS1 multimerization may autoregulate its actions. While RBD dimerization seems functionally conserved, two possible apo ED dimers have been proposed (helix-helix and strand-strand). Here, we analyze all available RBD, ED, and full-length NS1 structures, including four novel crystal structures obtained using EDs from divergent human and avian viruses, as well as two forms of a monomeric ED mutant. The data reveal the helix-helix interface as the only strictly conserved ED homodimeric contact. Furthermore, a mutant NS1 unable to form the helix-helix dimer is compromised in its ability to bind dsRNA efficiently, implying that ED multimerization influences RBD activity. Our bioinformatical work also suggests that the helix-helix interface is variable and transient, thereby allowing two ED monomers to twist relative to one another and possibly separate. In this regard, we found a mAb that recognizes NS1 via a residue completely buried within the ED helix-helix interface, and which may help highlight potential different conformational populations of NS1 (putatively termed 'helix-closed' and 'helix-open') in virus-infected cells. 'Helix-closed' conformations appear to enhance dsRNA binding, and 'helix-open' conformations allow otherwise inaccessible interactions with host factors. Our data support a new model of NS1 regulation in which the RBD remains dimeric throughout infection, while the ED switches between several quaternary states in order to expand its functional space. Such a concept may be applicable to other small multifunctional proteins

The effects of antipsychotic medications on emotion perception in patients with chronic schizophrenia in the CATIE trial

AbstractFew pharmacological intervention studies have examined the impact of medication on social cognition, particularly emotion perception. The goal of this randomized, double-blind study is to compare the effects of several second generation antipsychotics and a first generation antipsychotic, perphenazine, on emotion perception in individuals with schizophrenia. Patients were assigned to receive treatment with olanzapine, queitapine fumarate, risperidone, ziprasidone or perphenazine for up to 18months. Eight hundred and seventy three patients completed an emotion perception test immediately prior to randomization and after 2months of treatment. We also examined baseline predictors of emotion perception change. Most treatments were associated with a small, non-statistically significant improvement in emotion perception at two months, although they did not differ from one another. Greater improvement in emotion perception at 2months was significantly predicted by lower baseline emotion perception and higher baseline neurocognitive functioning, and marginally predicted by less time on an antipsychotic

Sacred Cows and Sympathetic Squirrels: The Importance of Biological Diversity to Human Health

Dobson and colleagues describe how some host species act to reduce the risk of transmission of virulent zoonotic pathogens to humans