A time-correlated single photon counting SPAD array camera with a bespoke data-processing algorithm for lightsheet fluorescence lifetime imaging (FLIM) and FLIM videos.

A wide-field microscope with epi-fluorescence and selective plane illumination was combined with a single-photon avalanche diode (SPAD) array camera to enable live-cell fluorescence lifetime imaging (FLIM) using time-correlated single-photon counting (TCSPC). The camera sensor comprised of 192 × 128 pixels, each integrating a single SPAD and a time-to-digital converter. Jointly, they produced a stream of single-photon images of photon arrival times with ≈ 38 ps accuracy. The photon arrival times were subject to systematic delays and nonlinearities, which were corrected by a Monte-Carlo algorithm. The SPAD camera was then applied to FLIM where histogramming the resulting photon arrival times in each pixel resulted in decays compatible with common data processing pipelines for fluorescence lifetime analysis. The capabilities of the TCSPC camera-based FLIM microscope were demonstrated by imaging living unicellular photosynthetic algae and artificial lipid vesicles. Epi-fluorescence illumination enabled rapid fluorescence lifetime imaging of living cells and selective-plane illumination enabled 3-dimensional FLIM of stationary samples.

Human identification: a review of methods employed within an Australian coronial death investigation system.

Whilst many identification methods have been widely described and discussed in the literature, and considered in disaster and humanitarian contexts, there has been limited reporting and evaluation of the identification methods used in domestic medico-legal death investigation contexts. The aim of this study was to evaluate the identification methods utilised at the Victorian Institute of Forensic Medicine (VIFM), which forms part of a coronial medico-legal death investigation system. The method of identification and time taken to complete the identification were reviewed for all cases admitted to the VIFM over a five-year period from 1 July 2015 to 30 June 2020. The majority, 91%, of individuals admitted to the VIFM were visually identified. The remaining 9% of cases required identification by primary methods (i.e. fingerprints, DNA or dental) or, when those methods were not possible, by secondary methods (i.e. circumstantial). Visual identifications were the timeliest, taking an average of 1.5 days, whilst primary identification methods required an average of 5 days to complete. The triaging of identification methods, dependent on the case context, body preservation, availability of ante-mortem data, legal requirements and admissibility of the method, are determined by identification coordinators within the Human Identification Service (HIS) to ensure the most appropriate and timely method is employed. This review of human identification methods provides the foundation for future analyses to compare workflow processes and improve identification methods utilised in domestic medico-legal contexts.

Experimental nitrogen addition alters structure and function of a boreal poor fen: Implications for critical loads.

Bogs and fens cover 6 and 21%, respectively, of the 140,329 km2 Oil Sands Administrative Area in northern Alberta. Regional background atmospheric N deposition is low (<2 kg N ha-1 yr-1), but oil sands development has led to increasing N deposition (as high as 17 kg N ha-1 yr-1). To examine responses to N deposition, over five years, we experimentally applied N (as NH4NO3) to a poor fen near Mariana Lake, Alberta, unaffected by oil sands activities, at rates of 0, 5, 10, 15, 20, and 25 kg N ha-1 yr-1, plus controls (no water or N addition). At Mariana Lake Poor Fen (MLPF), increasing N addition: 1) progressively inhibited N2-fixation; 2) had no effect on net primary production (NPP) of Sphagnum fuscum or S. angustifolium, while stimulating S. magellanicum NPP; 3) led to decreased abundance of S. fuscum and increased abundance of S. angustifolium, S. magellanicum, Andromeda polifolia, Vaccinium oxycoccos, and of vascular plants in general; 4) led to an increase in stem N concentrations in S. angustifolium and S. magellanicum, and an increase in leaf N concentrations in Chamaedaphne calyculata, Andromeda polifolia, and Vaccinium oxycoccos; 5) stimulated root biomass and production; 6) stimulated decomposition of cellulose, but not of Sphagnum or vascular plant litter; and 7) had no or minimal effects on net N mineralization in surface peat, NH4+-N, NO3--N or DON concentrations in surface porewater, or peat microbial composition. Increasing N addition led to a switch from new N inputs being taken up primarily by Sphagnum to being taken up primarily by shrubs. MLPF responses to increasing N addition did not exhibit threshold triggers, but rather began as soon as N additions increased. Considering all responses to N addition, we recommend a critical load for poor fens in Alberta of 3 kg N ha-1 yr-1.

Teaching of forensic odontology in basic dental programmes in nine Australian dental schools: A survey.

PURPOSE: The aim of this survey was to determine whether forensic odontology forms part of the basic dental programme in the nine Australian dental schools, which aspects of forensic odontology were taught, and the barriers and issues that prevent forensic odontology being part of any dental curriculum. The survey also examines the teaching of cranio-facial anatomy and dental record-keeping, as these two subjects can play an important role in forensic odontology. MATERIALS AND METHODS: Study design and participants: A postal questionnaire survey on the teaching of forensic odontology was conducted between November 2016 and April 2017, being sent to the dean of school, head of school, or acting head of school, each representing the nine Australian dental schools. The paper questionnaire consisted of eight questions requesting information concerning whether or not the dental school has faculty staff who are registered forensic odontologists or registered general dentists with a forensic odontology postgraduate qualification, and how many hours of teaching (including lectures and practicals) were dedicated to cranio-facial anatomy and dental record-keeping. RESULTS: Five out of nine dental schools replied to the questionnaire. This gives a response rate of 55.56%. Staff members: Four dental schools had at least one or more forensically trained staff members. Only one dental school did not have a staff member who is trained in forensic odontology. Cranio-facial anatomy: Three out of the five dental schools responded that each of the cranio-facial anatomy lecture and practical programmes were more than 16 hours each throughout the whole dental programme, whereas the other two dental schools responded that each of the lecture and practical programmes were between 7 and 11 hours. Dental record-keeping: All five dental schools responded that the lecture hours dedicated to dental record-keeping are between 1 and 6 hours throughout the whole dental programme. For the practical sessions, three out of the five dental schools responded that the hours dedicated are between 1 and 6 hours. Teaching of forensic odontology: Three out of the five dental schools responded that forensic odontology is taught as part of a dental subject in the dental programme, with the total hours dedicated to the teaching being between 1 and 6 hours, with teaching being delivered in the form of lectures only. Two of the five dental schools that did not teach forensic odontology as part of any dental subjects mentioned that the main reason for not teaching forensic odontology is due to lack of teaching time. CONCLUSION: This is the first Australian project investigating the teaching of forensic odontology in Australian dental schools. The authors found that three dental schools teach forensic odontology; however, it is limited to only 1 to 6 hours of teaching time. All five dental schools teach extensively into cranio-facial anatomy and dental record-keeping. However, as one of the recognised dental specialities in Australia, and the role it plays in justice, human rights and humanitarianism, all Australian dental schools should provide an opportunity for students to learn and be aware of forensic odontology as part of their training programmes, which include the importance of accurate dental records and its application to forensic odontology.

Directed Self-Assembly of Ge Quantum Dots Using Focused Si2+ Ion Beam Patterning.

We show that templating a Si surface with a focused beam of Si2+ or Si+ ions can create suitable nucleation sites for the subsequent growth of self-assembled Ge quantum dots by chemical vapor deposition. To determine the mechanism of patterning we use atomic force microscopy to show that, similar to Ga+ patterning, the formation of a surface pit is required to enable control over Ge quantum dot locations. We find that relatively high implantation doses are required to achieve patterning, and these doses lead to amorphization of the substrate. We assess the degree to which the substrate crystallinity can be recovered by subsequent processing. Using in situ transmission electron microscopy heating experiments we find that recrystallization is possible at the growth temperature of the Ge quantum dots, but defects remain that follow the pattern of the initial implantation. We discuss the formation mechanism of the defects and the benefits of using Si ions for patterning both defects and quantum dots on Si substrates.

A novel multisite confocal system for rapid Ca2+ imaging from submicron structures in brain slices.

In brain slices, resolving fast Ca2+ fluorescence signals from submicron structures is typically achieved using 2-photon or confocal scanning microscopy, an approach that limits the number of scanned points. The novel multiplexing confocal system presented here overcomes this limitation. This system is based on a fast spinning disk, a multimode diode laser and a novel high-resolution CMOS camera. The spinning disk, running at 20 000 rpm, has custom-designed spiral pattern that maximises light collection, while rejecting out-of-focus fluorescence to resolve signals from small neuronal compartments. Using a 60× objective, the camera permits acquisitions of tens of thousands of pixels at resolutions of ~250 nm per pixel in the kHz range with 14 bits of digital depth. The system can resolve physiological Ca2+ transients from submicron structures at 20 to 40 µm below the slice surface, using the low-affinity Ca2+ indicator Oregon Green BAPTA-5N. In particular, signals at 0.25 to 1.25 kHz were resolved in single trials, or through averages of a few recordings, from dendritic spines and small parent dendrites in cerebellar Purkinje neurons. Thanks to an unprecedented combination of temporal and spatial resolution with relatively simple implementation, it is expected that this system will be widely adopted for multisite monitoring of Ca2+ signals.

Medical Humanities Coursework Is Associated with Greater Measured Empathy in Medical Students.

PURPOSE: The primary focus of the study was to determine whether coursework in the medical humanities would ameliorate students' loss of and failure to develop empathy, a problem known to be common during medical education. METHODS: Students were offered an elective course in the Medical Humanities for academic credit. The Jefferson Scale of Empathy Student Version (JSE-S) was administered at the beginning and end of an academic year in which humanities courses were offered. Changes in JSE-S scores among students who studied Medical Humanities were compared with changes in student who did not take any humanities coursework. RESULTS: Medical humanities coursework correlated with superior empathy outcomes among the medical students. Of students not enrolled in humanities courses, 71% declined or failed to increase in JSE-S score over the academic year. Of those who took humanities coursework, 46% declined or failed to increase in JSE-S scores. The difference was statistically significant (P = .03). The medical humanities curriculum correlated with favorable empathy outcomes as measured by the JSE-S. CONCLUSIONS: Elective medical humanities coursework correlated with improved empathy score outcomes in a group of US medical students. This may reflect a direct effect of the humanities coursework. Alternately, students' elective choice to take medical humanities coursework may be a marker for students with a propensity to favorable empathy outcomes.

A Facile Solvothermal Synthesis of Octahedral Fe3 O4 Nanoparticles.

Anisotropic Fe3 O4 octahedrons are obtained via a simple solvothermal synthesis with appropriate sizes for various technological applications. A complete suite of materials characterization methods confirms the magnetite phase for these structures, which exhibit substantial saturation magnetization and intriguing morphologies for a wide range of applications.

Surface plasmon-driven water reduction: gold nanoparticle size matters.

Water reduction under two different visible-light ranges (λ > 400 nm and λ > 435 nm) was investigated in gold-loaded titanium dioxide (Au-TiO2) heterostructures with different sizes of Au nanoparticles (NPs). Our study clearly demonstrates the essential role played by Au NP size in plasmon-driven H2O reduction and reveals two distinct mechanisms to clarify visible-light photocatalytic activity under different excitation conditions. The size of the Au NP governs the efficiency of plasmon-mediated electron transfer and plays a critical role in determining the reduction potentials of the electrons transferred to the TiO2 conduction band. Our discovery provides a facile method of manipulating photocatalytic activity simply by varying the Au NP size and is expected to greatly facilitate the design of suitable plasmonic photocatalysts for solar-to-fuel energy conversion.

Economic and simple system to combine single-spot photolysis and whole-field fluorescence imaging.

ABSTRACT. In recent years, the use of light emitting diodes (LEDs) has become commonplace in fluorescence microscopy. LEDs are economical and easy to couple to commercial microscopes, and they provide powerful and stable light that can be triggered by transistor-transistor logic pulses in the range of tens of microseconds or shorter. LEDs are usually installed on the epifluorescence port of the microscope to obtain whole-field illumination, which is ideal for fluorescence imaging. In contrast, photolysis or channelrhodopsin stimulation often requires localized illumination, typically achieved using lasers. Here we show that insertion of a long-pass (>411 nm) filter with an appropriately sized pinhole in the epifluorescence pathway, combined with dual UV/visible illumination, can produce efficient whole-field visible illumination and spot UV illumination of 15 to 20 µm. We tested our system by performing calcium imaging experiments combined with L-glutamate or N-methyl-D-aspartic acid (NMDA) photorelease in hippocampal neurons from brain slices or dissociated cultures, demonstrating the ability to obtain local activation of NMDA receptors exclusively in the illuminated spot. The very inexpensive and simple system that we report here will allow many laboratories with limited budgets to run similar experiments in a variety of physiological applications.

A multisite, multistakeholder validation of the Accreditation Council for Graduate Medical Education competencies.

PURPOSE: The Accreditation Council for Graduate Medical Education's (ACGME's) six-competency framework has not been validated across multiple stakeholders and sites. The objective of this study was to perform a multisite validation with five stakeholder groups. METHOD: This was a cross-sectional, observational study carried out from October to December, 2011, in the internal medicine residency continuity clinics of eight internal medicine residency programs in the Pacific Northwest, including a VA, two academic medical centers, a military medical center, and four private hospitals. The authors performed a cultural consensus analysis (CCA) and a convergent-discriminant analysis using previously developed statements based on internal medicine milestones related to the six competencies. Ten participants were included from each of five stakeholder groups: patients, nurses, residents, faculty members, and administrators from each training site (total: 400 participants). RESULTS: Moderate to high agreement and coherence for all groups were observed (CCA eigenvalue ratios ranging from 2.16 to 3.20); however, high differences in ranking order were seen between groups in four of the CCA statements, which may suggest between-group tension in these areas. Analyses revealed excellent construct validity (Zcontrast score of 5.323, P < .0001) for the six-competency framework. Average Spearman correlation between same-node statements was 0.012, and between different-node statements it was -0.096. CONCLUSIONS: The ACGME's six-competency framework has reasonable face and construct validity across multiple stakeholders and sites. Stakeholders appear to share a single mental model of competence in this learning environment. Data patterns suggest possible improvements to the competency-milestone framework.