Search

Abstract Background The effects of COVID-19 lockdown measures on maternal and fetal health remain unclear. We examined the associations of COVID-19 lockdown with gestational length and preterm birth (PTB) in a Chinese population. Methods We obtained medical records of 595,396 singleton live infants born between 2015 and 2020 in 5 cities in Guangdong Province, South China. The exposed group (N = 101,900) included women who experienced the COVID-19 Level I lockdown (1/23–2/24/2020) during pregnancy, while the unexposed group (N = 493,496) included women who were pregnant during the same calendar months in 2015–2019. Cumulative exposure was calculated based on days exposed to different levels of emergency responses with different weighting. Generalized linear regression models were applied to estimate the associations of lockdown exposure with gestational length and risk of PTB (

Abstract Recent wildfires across western North America have burned with uncharacteristically high severity, representing a substantial departure from natural fire regimes. In mixed‐conifer and pine–oak ecosystems of the southern Cascade Range, widespread shifts in stand structure and composition have led to a diversity of post‐wildfire vegetation responses. When recent wildfire “footprints” reburn in subsequent fires, their recovery pathways are complex. In order to understand the effects of overlapping mixed‐severity fires, we quantified changes in overstory and midstory structure and species composition for time periods prior to and following two large overlapping wildfires in the southern Cascades: the 2000 Storrie and 2012 Chips Fires. Plots were stratified into 16 severity combinations (unburned, low, moderate, and high in the Storrie Fire combined with the same four categories in the Chips Fire: e.g., moderate Storrie/high Chips) across the 9000‐ha overlapping burned area. Following the two fires, tree quadratic mean diameter and stand density declined for most species, but changes were species‐specific. Compared with preburn values, importance values for fire‐sensitive white fir (Abies concolor) were reduced by 66%, while resprouting fire‐resilient California black oak (Quercus kelloggii) importance values increased by 37% in severity combinations that included at least one high‐severity fire. Greatest shifts were documented in sites that burned twice at high severity, where resulting vegetation was dominated by oak sprout clumps and resprouting and fire‐stimulated montane chaparral species, while unburned and low‐severity strata retained a substantial component of Douglas‐fir (Pseudotsuga menziesii) and white fir. Results suggest that repeated moderate‐ and high‐severity fires can result in ecosystem state shifting toward fire‐resilient oak‐shrub communities in this fire‐prone landscape. Managers seeking greater landscape resilience can implement treatments such as thinning and prescribed burning, while taking advantage of fire‐created patches such as these in areas where the likelihood of a hotter and drier future makes the reestablishment of continuous forest cover unrealistic.

Background and purpose: Scatter correction of cone-beam computed tomography (CBCT) projections may enable accurate online dose-delivery estimations in photon and proton-based radiotherapy. This study aimed to evaluate the impact of scatter correction in CBCT-based proton range/dose calculations, in scans acquired in both proton and photon gantries. Material and methods: CBCT projections of a Catphan and an Alderson phantom were acquired on both a proton and a photon gantry. The scatter corrected CBCTs (corrCBCTs) and the clinical reconstructions (stdCBCTs) were compared against CTs rigidly registered to the CBCTs (rigidCTs). The CBCTs of the Catphan phantom were segmented by materials for CT number analysis. Water equivalent path length (WEPL) maps were calculated through the Alderson phantom while proton plans optimized on the rigidCT and recalculated on all CBCTs were compared in a gamma analysis. Results: In medium and high-density materials, the corrCBCT CT numbers were much closer to those of the rigidCT than the stdCBCTs. E.g. in the 50% bone segmentations the differences were reduced from above 300 HU (with stdCBCT) to around 60–70 HU (with corrCBCT). Differences in WEPL from the rigidCT were typically well below 5 mm for the corrCBCTs, compared to well above 10 mm for the stdCBCTs with the largest deviations in the head and thorax regions. Gamma pass rates (2%/2mm) when comparing CBCT-based dose re-calculations to rigidCT calculations were improved from around 80% (with stdCBCT) to mostly above 90% (with corrCBCT). Conclusion: Scatter correction leads to substantial artefact reductions, improving accuracy of CBCT-based proton range/dose calculations.

Abstract Congenital hypoplasia of the massetermasseter Level of Evidence: 5

Bone tissue is a complex organic-inorganic nanocomposite and strategies that replicate the characteristics of bone tissue are scarce. Here the authors demonstrate the deposition of nanoscale apatite in collagen embedded with mesenchymal, vascular and nerve cells, using a protein-guided biomineralization approach.

Background: The effect of the Köhler group dynamics paradigm (i.e., working together with a more capable partner where one's performance is indispensable to the team outcome) has been shown to increase motivation to exercise longer at a strength task in partnered exercise video games (exergames) using a software-generated partner (SGP). However, the effect on exercise intensity with an SGP has not been investigated. The purpose of this study was to examine the motivation to maintain or increase exercise intensity among healthy, physically active middle-aged adults using an SGP in an aerobic exergame. Methods: Participants (n = 85, mean age = 44.9 years) exercised with an SGP in a 6-day cycle ergometer protocol, randomly assigned to either (a) no partner control, (b) superior SGP who was not a teammate, or (c) superior SGP as a teammate (team score was dependent on the inferior member). The protocol alternated between 30-min continuous and 4-min interval high-intensity session days, during which participants could change cycle power output (watts) from target intensity to alter distance and speed. Results: Mean change in watts from a targeted intensity (75% and 90% maximum heart rate) was the primary dependent variable reflecting motivational effort. Increases in performance over baseline were demonstrated without significant differences between conditions. Self-efficacy and enjoyment were significantly related to effort in the more intense interval sessions. Conclusion: Under these conditions, no Köhler effect was observed. Exercise performance during the higher-intensity interval format is more closely related to enjoyment and self-efficacy beliefs compared to the continuous sessions. Keywords: Exercise intensity, Köhler effect, Motivation, Software-generated partner

Purpose: This study aimed to develop a linac-mounted kilovoltage (kV) projection streaming-based tracking method for vertebral targets during spine stereotactic radiation surgery and evaluate the clinical feasibility of the proposed spine tracking method. Methods and materials: Using real-time kV projection streaming within XVI (Elekta XVI), kV–projection-based tracking was applied to the target vertebral bodies. Two-dimensional in-plane patient translation was calculated via an image registration between digitally reconstructed radiographs (DRRs) and kV projections. DRR was generated from the cone beam computed tomography (CBCT) scan, which was obtained immediately before the tracking session. During a tracking session, each kV projection was streamed for an intensity gradient-based image with similar metric-based registration to the offset DRR. The ground truth displacement for each kV beam angle was calculated at the beam isocenter using the 6 degrees-of-freedom transformation that was obtained by a CBCT-CBCT rigid registration. The resulting translation by the DRR-projection registration was compared with the ground truth displacement. The proposed tracking method was evaluated retrospectively and online, using 7 and 5 spine patients, respectively. Results: The accuracy and precision of spine tracking for in-plane patient motion were 0.5 ± 0.2 and 0.2 ± 0.1 mm. The magnitude of patient motion that was estimated using the CBCT-CBCT rigid registration was (0.5 ± 0.4, 0.4 ± 0.3, 0.3 ± 0.3) mm and (0.3 ± 0.4, 0.2 ± 0.2, 0.5 ± 0.6) mm for all tracking sessions. The intrafraction motion was within 2 mm for all CBCT scans considered. Conclusions: This study demonstrated that the proposed spine tracking method can track intrafraction motion with sub-millimeter accuracy and precision, and sub-second latency.

Abstract Object Stereotactic body radiotherapy (SBRT) for vertebral metastases has emerged as a promising technique, offering high rates of symptom relief and local control combined with low risk of toxicity. Nonetheless, local failure or vertebral instability may occur after spine SBRT, generating the need for subsequent surgery in the irradiated region. This study evaluated whether there is an increased incidence of surgical complications in patients previously treated with SBRT at the index level. Methods Based upon a retrospective international database of 704 cases treated with SBRT for vertebral metastases, 30 patients treated at 6 different institutions were identified who underwent surgery in a region previously treated with SBRT. Results Thirty patients, median age 59 years (range 27–84 years) underwent SBRT for 32 vertebral metastases followed by surgery at the same vertebra. Median follow-up time from SBRT was 17 months. In 17 cases, conventional radiotherapy had been delivered prior to SBRT at a median dose of 30 Gy in median 10 fractions. SBRT was administered with a median prescription dose of 19.3 Gy (range 15–65 Gy) delivered in median 1 fraction (range 1–17) (median EQD2/10 = 44 Gy). The median time interval between SBRT and surgical salvage therapy was 6 months (range 1–39 months). Reasons for subsequent surgery were pain (n = 28), neurological deterioration (n = 15) or fracture of the vertebral body (n = 13). Open surgical decompression (n = 24) and/or stabilization (n = 18) were most frequently performed; Five patients (6 vertebrae) were treated without complications with vertebroplasty only. Increased fibrosis complicating the surgical procedure was explicitly stated in one surgical report. Two durotomies occurred which were closed during the operation, associated with a neurological deficit in one patient. Median blood loss was 500 ml, but five patients had a blood loss of more than 1 l during the procedure. Delayed wound healing was reported in two cases. One patient died within 30 days of the operation. Conclusion In this series of surgical interventions following spine SBRT, the overall complication rate was 19%, which appears comparable to primary surgery without previous SBRT. Prior spine SBRT does not appear to significantly increase the risk of intra- and post-surgical complications.

Category: Ankle, Sports, Trauma Introduction/Purpose: The purpose of this study was to determine the injury characteristics of ankle and lower leg injuries in professional baseball players during the 2011-2016 seasons by utilizing the Major League Baseball (MLB) injury surveillance system. Methods: Our study is a descriptive epidemiological evaluation through a retrospective review from the MLB Health and Injury Tracking System (HITS) since its implementation in 2011. We included any professional baseball player (Major League and Minor League) who was identified as having an ankle or lower leg injury from January 1, 2011 through February 28th, 2017.Over the study period there were a total of 4,756 injuries of which 763 (16.0%) occurred in the Major League and 3,993 (84.0%) occurred in the Minor League. Results: The average number of days missed for all players was 27.8 days (+/-141.4 days) with a median of 3 days. From 2011 through 2016 it was estimated that there were 414,912 athlete exposures (AEs) in Major League Baseball and 1,796,607 AEs in the Minor Leagues. Of the 4,756 injuries recorded, 550 (11.6%) took place during the Major League regular season and 3,320 (69.8%) took place during the Minor League regular season. Major League injuries, however, were 1.7 times more likely to require surgery (p < .001). Additionally, rates of injury to the lower leg were stratified by position with infield players experiencing injuries at a 1.6 times greater rate than any other position (p < .001). Conclusion: In conclusion, the data from this study represents the only epidemiological study to focus primarily on lower leg injuries in professional baseball players utilizing an injury surveillance system developed by MLB.

Abstract Background Astronauts may have difficulty adhering to exercise regimens at vigorous intensity levels during long space missions. Vigorous exercise is important for aerobic and musculoskeletal health during space missions and afterwards. A key impediment to maintaining vigorous exercise is motivation. Finding ways to motivate astronauts to exercise at levels necessary to mitigate reductions in musculoskeletal health and aerobic capacity have not been explored. The focus of Simulated Partners and Collaborative Exercise (SPACE) is to use recently documented motivation gains in task groups to heighten the exercise experience for participants, similar in age and fitness to astronauts, for vigorous exercise over a 6-month exercise regimen. A secondary focus is to determine the most effective features in simulated exercise partners for enhancing enjoyment, self-efficacy, and social connectedness. The aims of the project are to (1) Create software-generated (SG) exercise partners and interface software with a cycle ergometer; (2) Pilot test design features of SG partners within a video exercise game (exergame), and (3) Test whether exercising with an SG partner over 24-week time period, compared to exercising alone, leads to greater work effort, aerobic capacity, muscle strength, exercise adherence, and enhanced psychological parameters. Methods/Design This study was approved by the Institutional Review Board (IRB). Chronic exercisers, between the ages 30 and 62, were asked to exercise on a cycle ergometer 6 days per week for 24 weeks using a routine consisting of alternating between moderate-intensity continuous and high-intensity interval sessions. Participants were assigned to one of three conditions: no partner (control), always faster SG partner, or SG partner who was not always faster. Participants were told they could vary cycle ergometer output to increase or decrease intensity during the sessions. Mean change in cycle ergometer power (watts) from the initial continuous and 4 min. interval sessions was the primary dependent variable reflecting work effort. Measures of physiological, strength, and psychological parameters were also taken. Discussion This paper describes the rationale, development, and methods of the SPACE exergame. We believe this will be a viable intervention that can be disseminated for astronaut use and adapted for use by other populations.

Category: Other Introduction/Purpose: The management of pain in patients with foot and ankle pain can be challenging. Cumulative data suggest that, in addition to nociceptive mechanisms, other neuropathic mechanisms can contribute to pain in a subset of people with osteoarthritis. Neuropathic mechanism include central sensitization or peripheral neuropathic hyper activated pain. Heterogeneous pain mechanisms may explain variable responses to recommended pain therapies. Accurate classification of pain phenotype using clinically feasible tools has potential to improve pain management. The PainDETECT score, a validated patient-report questionnaire was developed to identify neuropathic pain. A recent study found a prevalence of 23% of neuropathic pain following ORIF of Ankle fractures. The purpose of this study is to examine the prevalence of neuropathic pain (NP) in a variety of foot and ankle disorders. Methods: This is a cross-sectional study investigating the prevalence of NP in a population of patients undergoing foot and ankle surgery. The patient cohort will include 500 patients. Patients were prospectively reviewed, prior to their surgery, using a patient-self-report questionnaire (painDETECT). Patients’ demographics, diagnosis, comorbidities and functional scores were also prospectively collected. painDETECT score of less than 13 was considered as Nociceptive, score of more than 18 was considered as Neuropathic. Scores of 12 to 18 were considered as Unclear. ANOVA and Student’s t-tests were performed to compare the pain VAS scores, duration of pain prior to surgery, severity of the disease and the prevalence of NP, and among different foot and ankle procedures (bone versus tissue, elective versus trauma) and procedural regions (hindfoot/ankle, midfoot, forefoot). Results: A total of 116 patients were included in this preliminary study. 9 patients (7.7%) were diagnosed with neuropathic pain and 24 (20.6%) were Unclear according to their results in the painDETECT. There were 28 patients scheduled for surgery due to recent trauma, none of which had neuropathic pain. One patient with neuropathic pain was scheduled for excision of Morton’s neuroma and 2 patients for removal of foreign body or hardware. There was no significant correlation with age, BMI or smoking status nor with the patients’ functional scores. Patients with NP described their worst and current level of pain significantly higher than those with nociceptive pain. (9.4 Vs 7.4 for worst pain and 6.9 Vs 4.6 for current level in a scale from 0-10, p-value

Category: Other Introduction/Purpose: The purpose of our study was to assess opioid consumption patterns following outpatient orthopaedic foot and ankle procedures in order to develop a pragmatic approach to narcotic drug prescription. Methods: Patients undergoing outpatient orthopaedic foot and ankle procedures who met inclusion criteria had the following prospective information collected: patient demographics, preoperative health history and Visual Analog Scale (VAS), anesthesia type, procedural details, and opioid prescription and consumption details. Utilization rates were compared using the Man-Whitney Test or the Kruskall-Wallis analysis of variance test with post-hoc Dunn’s multiple comparison test. Results: A total of 1,009 of 1,027 patients were included in this study (mean age: 49 years). Overall, patients consumed a median of 20 pills whereas the median number of pills prescribed was 40. This resulted in a utilization rate of 51% and nearly 21,196 pills left unused. Patients who received forefoot surgery used 6 pills less than those receiving hindfoot/ankle surgery (p=0.002). Patients between the ages of 60-79 consumed significantly less than those between 18-59 years old (p

Category: Ankle Introduction/Purpose: With the increase in number of total ankle arthroplasty surgery, physician guidelines on when to begin to consider patients’ return to driving is valuable. The ability to accurately and efficiently determine when a patient can return to driving is important both from a patient safety and a medicolegal perspective. The purpose of the study was to determine when patients’ brake reaction time (BRT) returns to a safe value after right total ankle arthroplasty. We also aimed to identify predictive factors that may identify those patients who may not be safe to drive. Methods: After institutional review board approval, fifty-five patients undergoing right total ankle arthroplasty were recruited prospectively. Patient demographics include an age range of 43 to 83 years (median 63 years), of which 31 were male (56%) and 24 were female (44%). BRT was tested at six weeks and repeated weekly until patients achieved a passing BRT. A control group of twenty healthy patients was used to establish a passing BRT of 0.850 seconds. Patients were given a validated, novel driver readiness survey to complete of which a 10/15 point or higher score was considered passing. Results: At 6 weeks, 50 patients (91%) achieved a passing BRT and were considered safe to drive, and the passing group average BRT was 0.662 seconds. At 9 weeks, 52 patients (100%) of those who completed the study achieved a passing BRT. Patients that failed at 6 weeks had statistically greater visual analog scale (VAS) for pain (p=0.037) and significantly diminished ankle plantarflexion (p=0.029). There is a significant (p

Category: Trauma Introduction/Purpose: Currently there is an epidemic in the United States regarding opioid abuse. This has resulted in strict government prescribing regulations throughout the country and increasing efforts by orthopaedic surgeons to better manage postoperative narcotic analgesia. Non-steroidal anti-inflammatory drugs (NSAIDs) can serve as a powerful adjunct in managing postoperative pain and in turn minimize the need for opioid medications. It has recently been shown that ketorolac can be used after open reduction and internal fixation (ORIF) of ankle fractures without interfering with bone healing. Therefore, we set out to evaluate whether including ketorolac in the postoperative drug regimen reduces opioid consumption and pain after ORIF of ankle fractures. Methods: 128 patients undergoing ORIF of an ankle fracture were prospectively randomized to treatment with or without ketorolac. Patients also had the option to simultaneously undergo regional anesthesia. Patients assigned to the treatment group were given 30 mg of IV ketorolac intraoperatively; prescribed 20 tablets of ketorolac 10 mg PO Q6 H and 30 tablets of Oxycodone/Acetaminophen 5/325 Q4-6 H PRN. Patients assigned to the control group were given 30 tablets of oxycodone/acetaminophen 5/325 Q4-6 H PRN only. A survey was distributed via Research Electronic Data Capture (REDCap) on postoperative days 1-7. Patients were asked to report their daily opioid consumption, pain level using the Visual Analog Scale (VAS), satisfaction with pain management, and side effects. Intention-to-treat analysis was performed. Normality of data was tested using the Shapiro-Wilk test. Differences between the control and treatment groups were tested using Mann-Whitney U or Student’s t-tests. Results: 105/128 (82%) patients with mean BMI of 29.3 completed all study requirements. 54 received ketorolac with opioid medication and 51 received opioids alone. 43 men (41%) and 62 women (59%) participated with mean age of 48 years. Patients receiving ketorolac required less oxycodone/acetaminophen (p0.139). Conclusion: The addition of ketorolac to the postoperative drug regimen significantly reduced pain, while decreasing the use of opioid medication following ORIF of ankle fractures early in the postoperative period. Better pain management during postoperative days 1 and 2 is particularly important because patients on average consume the most opioids during this time. With the assurance that ketorolac does not interfere with bone healing, this NSAID is a valuable tool for helping patients manage postoperative pain with less narcotic analgesia.

Category: Ankle, Ankle Arthritis, Arthroscopy, Bunion, Sports Introduction/Purpose: The time frame for safe return to driving is an important question amongst physicians and patients following orthopaedic surgery of the right lower extremity. There is no universally validated foot and ankle psychometric test that confirms patients’ ability to safely return to driving after surgery. The purpose of the study is to report a novel, validated survey that can be used to confirm safe return to driving after orthopaedic surgery of the right foot and ankle. Methods: Patients that had undergone right achilles rupture repair, total ankle arthroplasty, and hallux valgus correction by four fellowship-trained foot and ankle surgeons were prospectively included over a trial period of 4 months. A four-question survey (see Figure 1) was administered at the 6 week post-operative office visit. Breaking reaction time (BRT) was then assessed using the Reaction Time Tester, Model RT-2 S (Advanced Therapy Products, Glen Allen, VA). A passing BRT for safe return to driving was considered 0.850 seconds. Statistical analysis was performed and Cronbach’s alpha was calculated to determine validity of the survey relative to BRT results. One hundred and twenty-two patients were included with ages ranging from 21 to 76 years (average 45 years). Results: One hundred and nine (89%) of 122 patients achieved a braking time of 0.850 seconds or less. Using time-to-event analysis, 95% of patients passed at 7.6 weeks. With a “strongly agree” or “agree” response to question 4, the survey predicts a 96% certainty of passing the BRT. At first, validating the psychometric test across all three procedures resulting in a poor Cronbach’s a of 0.6. When question 3 was removed from statistical analysis, the Cronbach’s alpha was 0.76 and the psychometric test was validated for all studied procedures. Upon calculating a composite score from the 3-question survey, the optimum threshold for a passing braking time was at least 10 points resulting in a very good AUC score of 0.948. Conclusion: This novel, three-question driving readiness survey can accurately predict a passing breaking reaction test. This provides foot and ankle surgeons with a valuable tool to objectively determine if a patient can safely return to driving after achilles repair, total ankle arthroplasty, and hallux valgus correction. Further study is required to determine whether patients who come to clinic weeks before their standard post-operative follow up appointment with the belief that they are ready to drive also pass the BRT. Additional validation of the survey would be valuable across other foot and ankle procedures.

Category: Ankle, Trauma Introduction/Purpose: Ketorolac has been reported to delay bone healing when administered after spine surgery, and there is hesitancy to use non-steroidal anti-inflammatories (NSAIDs) in the fracture setting despite its reliable ability to relieve surgical pain. The effect of ketorolac administration after foot and ankle surgery has not been well-defined in the literature to date. The purpose of this study is to report clinical and radiographic outcomes for patients treated with a perioperative ketorolac regimen after open reduction and internal fixation (ORIF) of ankle fractures. A secondary purpose is to determine whether there are other patient factors that affect radiographic healing in this population. We hypothesize that the time to radiographic healing with ketorolac use after ORIF of ankle fractures is no different than a historical control. Methods: A retrospective chart review was performed on all patients that received perioperative ketorolac at the time of lateral malleolar, bimalleolar, and trimalleolar ankle ORIF by a single surgeon between 2010 and 2016 with minimum 4 months follow-up. Patients were prescribed 5 days of 10 mg ketorolac every 6 hours. Radiographs were evaluated independently by two blinded fellowship-trained foot and ankle surgeons to assess for radiographic healing of lateral malleolus, medial malleolus, and posterior malleolus fractures at 6, 12, and 16 weeks post-operatively. Two hundred and ninety-four patients were included with an average age of 50 years with 138 males (47%). Literature review was performed to determine an appropriate historical control of time to radiographic healing after ankle ORIF for comparison. Statistical analysis consisted of a linear mixed-effects regression which was performed to estimate the effect of time and covariates, taking into account repeated measurements on the same subject. Results: Radiographic healing was demonstrated by 16 weeks in 221 of 281 (79%) lateral malleolus fractures, 105 of 132 medial malleolus fractures (80%), and 53 of 57 (93%) posterior malleolus fractures (see Figure 1). Median healing times were 12, 11, and 6 weeks for lateral, medial, and posterior malleoli fractures respectively. There was no significant difference in time to radiographic healing of lateral malleolus when compared to a historical control of 16.7 weeks to union. Active tobacco use was an independent risk factor for delayed radiographic healing (p < 0.05). Diabetes mellitus and age greater than 50 years were independent factors associated with faster healing of the lateral malleolus fractures (p < 0.05). Rheumatoid arthritis, oral steroid use, and obesity had no effect on radiographic healing. Conclusion: Perioperative ketorolac use did not affect radiographic healing of ankle fractures after ORIF. As expected, active tobacco use was associated with slower radiographic healing. There is no evidence that ketorolac use further delayed union in smokers, but this may warrant further study. We unexpectedly identified diabetes mellitus and older age as factors associated with faster healing which also warrants further study. This is the first study to date examining the effect of ketorolac on radiographic time to union of ankle fractures. Further study may help determine whether ketorolac helps reduce opioid consumption and improve pain following ORIF of ankle fractures.

Accurate estimates of growth and structural changes are key for forest management tasks such as determination of optimal rotation times, optimal rotation times, site indices and for identifying areas experiencing difficulties to regenerate. Estimation of structural changes, especially for biomass, is also key to quantify greenhouse gas (GHG) emissions/sequestration. We compared two different modeling strategies to estimate changes in V, BA and B, at three different spatial aggregation levels using auxiliary information from two light detection and ranging (LiDAR) flights. The study area is Blacks Mountains Experimental Forest, a ponderosa pine dominated forest in Northern California for which two LiDAR acquisitions separated by six years were available. Analyzed strategies consisted of (1) directly modeling the observed changes as a function of the LiDAR auxiliary information ( δ -modeling method) and (2) modeling V, BA and B at two different points in time, including a term to account for the temporal correlation, and then computing the changes as the difference between the predicted values of V, BA and B for time two and time one. We analyzed predictions and measures of uncertainty at three different level of aggregation (i.e., pixels, stands or compartments and the entire study area). Results showed that changes were very weakly correlated with the LiDAR auxiliary information. Both modeling alternatives provided similar results with a better performance of the δ -modeling for the entire study area; however, this method also showed some inconsistencies and seemed to be very prone to extrapolation problems. The y -modeling method, which seems to be less prone to extrapolation problems, allows obtaining more outputs that are flexible and can outperform the δ -modeling method at the stand level. The weak correlation between changes in structural attributes and LiDAR auxiliary information indicates that pixel-level maps have very large uncertainties and estimation of change clearly requires some degree of spatial aggregation; additionally, in similar environments, it might be necessary to increase the time lapse between LiDAR acquisitions to obtain reliable estimates of change.

Within disciplines are a set of shared values and thought processes that students must master in order to become participants of that discipline. Information literacy as defined by the ACRL is a set of standards and principles that can apply to all disciplines. In order to produce information literate undergraduates in a given discipline, information literacy standards must be integrated with the values and processes of the discipline. In this study, librarians partnered with faculty in gender studies and molecular biology to integrate information literacy with courses in those areas. Student performance and attitudes improved as a result of the collaboration. This article discusses the collaboration process, the assessment methods and results, and the long-term importance of developing best practices for information literacy integration at the campus level through a disciplinary approach.

The hierarchical structure of bone and intrinsic material properties of its two primary constituents, carbonated apatite and fibrillar collagen, when being synergistically organized into an interpenetrating hard-soft composite, contribute to its excellent mechanical properties. Lamellar bone is the predominant structural motif in mammalian hard tissues; therefore, we believe the fabrication of a collagen/apatite composite with a hierarchical structure that emulates bone, consisting of a dense lamellar microstructure and a mineralized collagen fibril nanostructure, is an important first step toward the goal of regenerative bone tissue engineering. In this work, we exploit the liquid crystalline properties of collagen to fabricate dense matrices that assemble with cholesteric organization. The matrices were crosslinked via carbodiimide chemistry to improve mechanical properties, and are subsequently mineralized via the polymer-induced liquid-precursor (PILP) process to promote intrafibrillar mineralization. Neither the crosslinking procedure nor the mineralization affected the cholesteric collagen microstructures; notably, there was a positive trend toward higher stiffness with increasing crosslink density when measured by cantilever-based atomic force microscopy (AFM) nanoindentation. In the dry state, the average moduli of moderately (X51; 4.8 ± 4.3 GPa) and highly (X76; 7.8 ± 6.7 GPa) crosslinked PILP-mineralized liquid crystalline collagen (LCC) scaffolds were higher than the average modulus of bovine bone (5.5 ± 5.6 GPa).

Through a careful examination of the conditions under which Sir David Wilkie painted and exhibited his most well-received painting, 'Chelsea Pensioners Receiving the London Gazette Extraordinary of Thursday, June 22nd, 1815, Announcing the Battle at Waterloo!!!' (1822), this paper asserts that Wilkie established the primary iconographic conventions for newspapers in the nineteenth century. Commissioned by the Duke of Wellington, the painting was both the first to require a barrier to protect it from the adoring crowds who flocked to see it at the annual exhibition of the Royal Academy and commanded the highest price ever paid for a painting in Britain at that time. However, since then, 'Chelsea Pensioners' has received little attention by art historians; this paper seeks to rectify this dearth of scholarship by detailing its historical and political significance. I argue that 'Chelsea Pensioners' typifies Benedict Anderson’s theory of modern nations as ‘imagined communities’.

BackgroundPoisson regression modelling has been widely used to estimate the disease burden attributable to influenza, though not without concerns that some of the excess burden could be due to other causes. This study aims to provide annual estimates of the mortality and hospitalization burden attributable to both seasonal influenza and the 2009 A/H1N1 pandemic influenza for Canada, and to discuss issues related to the reliability of these estimates.MethodsWeekly time-series for all-cause mortality and regression models were used to estimate the number of deaths in Canada attributable to influenza from September 1992 to December 2009. To assess their robustness, the annual estimates derived from different parameterizations of the regression model for all-cause mortality were compared. In addition, the association between the annual estimates for mortality and hospitalization by age group, underlying cause of death or primary reason for admission and discharge status is discussed.ResultsThe crude influenza-attributed mortality rate based on all-cause mortality and averaged over 17 influenza seasons prior to the 2009 A/H1N1 pandemic was 11.3 (95%CI, 10.5 - 12.1) deaths per 100 000 population per year, or an average of 3,500 (95%CI, 3,200 - 3,700) deaths per year attributable to seasonal influenza. The estimated annual rates ranged from undetectable at the ecological level to more than 6000 deaths per year over the three A/Sydney seasons. In comparison, we attributed an estimated 740 deaths (95%CI, 350-1500) to A(H1N1)pdm09. Annual estimates from different model parameterizations were strongly correlated, as were estimates for mortality and morbidity; the higher A(H1N1)pdm09 burden in younger age groups was the most notable exception.InterpretationWith the exception of some of the Serfling models, differences in the ecological estimates of the disease burden attributable to influenza were small in comparison to the variation in disease burden from one season to another.