Fostering Transformative Learning, Self-reflexivity and Medical Citizenship Through Guided Tours of Disadvantaged Neighborhoods

Background and objectives: Medical school curricula increasingly seek to promote medical students’ commitment to redressing health disparities, but traditional pedagogical approaches have fallen short of this goal. The objective of this work was to assess the value of using community-based guided tours of disadvantaged neighborhoods to fill this gap. Methods: A total of 50 second-year medical students participated in a guided tour of disadvantaged public housing neighborhoods in Richmond, Virginia. Students completed self-reflexive writing exercises during a post-tour debriefing session. Student writings were analyzed to assess the tour’s effect on their awareness of poverty’s impact on vulnerable populations’ health and wellbeing, and their personal reactions to the tour. Results: Student writings indicated that the activity fostered transformative learning experiences around the issue of poverty and its effects on health and stimulated a personal commitment to working with underserved populations. Themes from qualitative analysis included: increased awareness of the extent of poverty, enhanced self-reflexive attitude towards personal feelings, biases and misperceptions concerning the poor, increased intentional awareness of the effects of poverty on patient health and well-being, and, encouragement to pursue careers of medical service. Conclusions: This pilot demonstrated that incorporating self-reflexive learning exercises into a brief community-based guided tour can enhance the social consciousness of medical students by deepening understandings of health disparities and promoting transformative learning experiences

Exhaust Thermal Management Using Cylinder Deactivation and Late Intake Valve Closing

Progressively stricter emission regulations have compelled diesel engine manufacturers to develop new technologies that reduce harmful pollutants like NOx and soot. While manufacturers have previously been able to meet these regulations through the use of on engine technology such as exhaust gas recirculation and multiple pulse injections, exhaust after treatment systems such as diesel particulate filters and selective catalytic reduction systems have become necessary to meet recent stricter policies. While these after treatment systems are incredibly effective at reducing harmful emissions, to operate effectively the system needs to be above a certain temperature level typically between 250 and 300°C. Many methods such as additional fueling or electrical heaters have been explored and used to increase the temperature of the exhaust gases passing through these systems to heat them faster or maintain temperature. The effect of cylinder deactivation, CDA, and late intake valve closing, LIVC, on raising exhaust gas temperatures was studied by performing load sweeps at 1200 RPM. The effect of CDA, CDA and LIVC, and CDA meeting specific NOx targets was analyzed. At low loads, CDA proved to be effective at raising exhaust temperature as well as providing an improvement in brake thermal efficiency, BTE. At higher loads, exhaust gas temperatures were also improved, but with a fuel consumption penalty. The introduction of LIVC in combination with CDA increased exhaust temperatures above 250°C, but did not improve BTE. The last sweeps, which targeted low NOx emissions, required the use of EGR and were able to raise temperatures above 250°C across all loads while meeting the targets. While meeting the targets, BTE was only improved at low loads. The sweeps demonstrated that CDA and CDA combined with LIVC can be an extremely effective technology for raising exhaust gas temperatures even at low loads where exhaust temperatures are usually lowest. In many cases, an improvement in BTE can be accomplished as well

Down woody debris microsites for growing black huckleberry shrubs

Black huckleberry (Vaccinium membranaceum) is a shrub in the heather family (Ericaceae) that is ecologically, economically, and culturally important in the Pacific and Inland Northwest. Despite its abundance in many forest environments, black huckleberry requires very specific habitat conditions to successfully establish, grow, and produce berries. Ideal black huckleberry habitat includes a partial canopy (~40% shade) of mature conifers like Douglas-fir or mountain hemlock, often at elevations above approximately 3,000 ft. Because of these specific growing conditions and other factors, black huckleberry has not been commercially cultivated so usually has to be accessed by picking from naturally established shrub fields. As previously burned areas fill in with trees, with fewer new burned areas due to fire suppression efforts and curtailment of Native burning, black huckleberry habitat has declined from the mid-twentieth century forward, putting huckleberry restoration at the forefront of today’s conservation efforts. Our study identified down woody debris (DWD) as a tool to facilitate favorable black huckleberry growing conditions in the absence of one or more of their habitat requirements. This structure occurs naturally in forest environments but can also be supplemented through logging or tree-felling operations, especially with “cull” logs that will not be used for forest products. Recent research has shown that DWD on the forest floor creates small areas of more favorable growing conditions for seedling establishment, known as microsites, compared to surrounding environments

Type Iax SNe as a few-parameter family

We present direct spectroscopic modeling of five Type Iax supernovae (SNe) with the one dimensional Monte Carlo radiative transfer code TARDIS. The abundance tomography technique is used to map the chemical structure and physical properties of the SN atmosphere. Through via fitting of multiple spectral epochs with self-consistent ejecta models, we can then constrain the location of some elements within the ejecta. The synthetic spectra of the best-fit models are able to reproduce the flux continuum and the main absorption features in the whole sample. We find that the mass fractions of IGEs and IMEs show a decreasing trend toward the outer regions of the atmospheres using density profiles similar to those of deflagration models in the literature. Oxygen is the only element, which could be dominant at higher velocities. The stratified abundance structure contradicts the well-mixed chemical profiles predicted by pure deflagration models. Based on the derived densities and abundances, a template model atmosphere is created for the SN Iax class and compared to the observed spectra. Free parameters are the scaling of the density profile, the velocity shift of the abundance template, and the peak luminosity. The results of this test support the idea that all SNe Iax can be described by a similar internal structure, which argues for a common origin of this class of explosions.Comment: 21 pages, 7 tables, 16 figures, accepted by MNRA

Distribution and function of HCN channels in the apical dendritic tuft of neocortical pyramidal neurons

The apical tuft is the most remote area of the dendritic tree of neocortical pyramidal neurons. Despite its distal location, the apical dendritic tuft of layer 5 pyramidal neurons receives substantial excitatory synaptic drive and actively processes corticocortical input during behavior. The properties of the voltage-activated ion channels that regulate synaptic integration in tuft dendrites have, however, not been thoroughly investigated. Here, we use electrophysiological and optical approaches to examine the subcellular distribution and function of hyperpolarization-activated cyclic nucleotide-gated nonselective cation (HCN) channels in rat layer 5B pyramidal neurons. Outside-out patch recordings demonstrated that the amplitude and properties of ensembleHCNchannel activity were uniform in patches excised from distal apical dendritic trunk and tuft sites. Simultaneous apical dendritic tuft and trunk whole-cell current-clamp recordings revealed that the pharmacological blockade of HCN channels decreased voltage compartmentalization and enhanced the generation and spread of apical dendritic tuft and trunk regenerative activity. Furthermore, multisite two-photon glutamate uncaging demonstrated that HCN channels control the amplitude and duration of synaptically evoked regenerative activity in the distal apical dendritic tuft. In contrast, at proximal apical dendritic trunk and somatic recording sites, the blockade of HCN channels decreased excitability. Dynamicclamp experiments revealed that these compartment-specific actions of HCN channels were heavily influenced by the local and distributed impact of the high density of HCN channels in the distal apical dendritic arbor. The properties and subcellular distribution pattern of HCN channels are therefore tuned to regulate the interaction between integration compartments in layer 5B pyramidal neurons

A Three-dimensional Printed Low-cost Anterior Shoulder Dislocation Model for Ultrasound-guided Injection Training.

Anterior shoulder dislocations are the most common, large joint dislocations that present to the emergency department (ED). Numerous studies support the use of intraarticular local anesthetic injections for the safe, effective, and time-saving reduction of these dislocations. Simulation training is an alternative and effective method for training compared to bedside learning. There are no commercially available ultrasound-compatible shoulder dislocation models. We utilized a three-dimensional (3D) printer to print a model that allows the visualization of the ultrasound anatomy (sonoanatomy) of an anterior shoulder dislocation. We utilized an open-source file of a shoulder, available from embodi3D® (Bellevue, WA, US). After approximating the relative orientation of the humerus to the glenoid fossa in an anterior dislocation, the humerus and scapula model was printed with an Ultimaker-2 Extended+ 3D® (Ultimaker, Cambridge, MA, US) printer using polylactic acid filaments. A 3D model of the external shoulder anatomy of a live human model was then created using Structure Sensor®(Occipital, San Francisco, CA, US), a 3D scanner. We aligned the printed dislocation model of the humerus and scapula within the resultant external shoulder mold. A pourable ballistics gel solution was used to create the final shoulder phantom. The use of simulation in medicine is widespread and growing, given the restrictions on work hours and a renewed focus on patient safety. The adage of see one, do one, teach one is being replaced by deliberate practice. Simulation allows such training to occur in a safe teaching environment. The ballistic gel and polylactic acid structure effectively reproduced the sonoanatomy of an anterior shoulder dislocation. The 3D printed model was effective for practicing an in-plane ultrasound-guided intraarticular joint injection. 3D printing is effective in producing a low-cost, ultrasound-capable model simulating an anterior shoulder dislocation. Future research will determine whether provider confidence and the use of intraarticular anesthesia for the management of shoulder dislocations will improve after utilizing this model

Fully Ir(iii) tetrazolate soft salts: the road to white-emitting ion pairs

The first examples of anionic Ir(iii) bis-tetrazolate complexes and their combination with a cationic Ir(iii)tetrazole derivative forming "fully tetrazolate" Ir(iii) based soft salts as O2-sensitive white emitters are described herein