Diet and occurrences of the letter-winged kite in a predation refuge.

Nomadism is an advantageous life history strategy for specialised predators because it enables the predator to respond rapidly to changes in prey populations. The letter-winged kite (Elanus scriptus) is a nomadic nocturnal bird of prey endemic to arid and semi-arid zones of Australia. Letter-winged kites prey almost exclusively on nocturnal rodents and are often associated with rodent irruptions, but little is known about the ecology of letter-winged kites inside their core range. The Strzelecki Desert contains a known dingo-mediated predation refuge for native rodents. In this manuscript, we compare kite sightings, predator activity, and small mammal populations across survey sites in the Strzelecki Desert where dingoes were common and where dingoes were rare and use publicly available data from the Atlas of Living Australia (ALA) to assess trends in the occurrence of kites in the region. Ninety-five percent of ALA observations occurred in areas where dingoes were common. Similarly, all our observations of kites occurred where dingoes were common and during an extended population irruption of Notomys fuscus. Notomys fuscus was the most frequent item in the letter-winged kite diet at our study sites. We suggest that there is significant evidence that these sites in the Strzelecki Desert form part of the core range for the letter-winged kite whose use of this area is facilitated by a predation refuge for rodents mediated by the dingo. We conclude that predation refuges mediated by dingoes could be a factor driving the distributions of letter-winged kites and other predators of rodents, particularly nomadic predators.

A Population-wide study of electrocardiographic (ECG) norms and the effect of demographic and anthropometric factors on selected ECG characteristics in young, Southeast Asian males-results from the Singapore Armed Forces ECG (SAFE) study.

BACKGROUND: Routine use of pre-participation electrocardiograms (ECGs) has been used by the Singapore Armed Forces, targeting early detection of significant cardiac diseases. We aim to describe the impact of demographic and anthropometric factors on ECG variables and establish a set of electrocardiographic reference ranges specific to a young male multiethnic Southeast Asian cohort. METHODS AND RESULTS: Between November 1, 2009, and December 31, 2014, 144,346 young male conscripts underwent pre-participation screening that included a 12-lead ECG, demographic and anthropometric measurements. The Chinese population had the longest PR interval (146.7 ± 19.7 vs. 145.21 ± 19.2 in Malays vs. 141.2 ± 18.8 ms in Indians), QRS duration (94.5 ± 9.8 vs. 92.6 ± 9.7 in Malays vs. 92.5 ± 9.4 ms in Indians) and QTcB interval (408.3 ± 21.3 vs. 403.5 ± 21.6 in Malays vs. 401.2 ± 21.4 ms in Indians) (all p < 0.001). Body mass index (BMI) >25 kg/m2 and body fat >25% were independently associated with lower prevalence of increased QRS voltage on ECG. Systolic blood pressure of >140 mmHg or diastolic blood pressure of >90 mmHg independently increased the prevalence of increased QRS voltage on ECG. CONCLUSIONS: Electrocardiographic parameters vary across different ethnicities and in comparison with international norms. In our population, diagnosis of increased QRS voltage by ECG is less prevalent with obesity and increased body fat. Further analysis of gold standard measurements for the diagnosis of LVH in our population is ongoing, to improve the accuracy of the ECG screening process.

Left atrial appendage morphology and risk of stroke following pulmonary vein isolation for drug-refractory atrial fibrillation in low CHA2DS2Vasc risk patients.

BACKGROUND: Cardiac CT angiography (CCTA) has become an important adjunct in the structural assessment of the pulmonary veins (PV) prior to pulmonary vein isolation (PVI). Published data is conflicting regarding a relationship between left atrial appendage (LAA) and the risk of ischemic stroke (CVA) following PVI. We investigated the associations of volumetric and morphologic left atrial (LA) and LAA measurements for CVA following PVI. METHODS: We retrospectively reviewed 332 consecutive patients with drug refractory atrial fibrillation who obtained cardiac CT angiogram (CCTA) prior to PVI. Baseline demographic data, procedural and lab details, and outcomes were obtained from abstraction of an electronic medical records system. LA, LAA, and PV volumes were measured using CCTA datasets utilizing a semi-automated 3D workstation application. LAA morphology was assigned utilizing volume rendered images as previously described. RESULTS: The study cohort was 55 ± 13 years-old, 83.7% male, low CVA risk (median CHA2DS2Vasc 1; IQR 1, 3), and 30.4% were treated with novel oral anticoagulants. Chicken wing (CW) was the most common morphology (52%), followed by windsock (WS), cauliflower (CF), and cactus (CS) at 18, 9, and 2%, respectively. CVAs occurred in 4 patients following PVI with median time to CVA of 170.5 days. All CVAs were observed in CW morphology patients. When comparing CW morphology with non-CW morphology, CVAs occurred more frequently with the CW morphology (2.1% vs 0%, p = 0.03). This difference was not significant, though, after adjusting for CHA2DS2Vasc risk factors (p = 0.14). CONCLUSION: The CW morphology was observed more commonly in patients who experienced post-PVI CVA. After adjusting for CHA2DS2Vasc risk factors, CW morphology was not an independent predictor of post-PVI CVA. These findings should be interpreted in the setting of a low CVA event rate amongst a low risk population that was highly compliant with indicated anticoagulation therapy.

Vector-based feedback of continuous wave radiofrequency compression cavity for ultrafast electron diffraction.

The temporal resolution of ultrafast electron diffraction at weakly relativistic beam energies (≲100 keV) suffers from space-charge induced electron pulse broadening. We describe the implementation of a radio frequency (RF) cavity operating in the continuous wave regime to compress high repetition rate electron bunches from a 40.4 kV DC photoinjector for ultrafast electron diffraction applications. Active stabilization of the RF amplitude and phase through a feedback loop based on the demodulated in-phase and quadrature components of the RF signal is demonstrated. This scheme yields 144 ± 19 fs RMS temporal resolution in pump-probe studies.

Photochemical Control of Network Topology in PEG Hydrogels.

Hydrogels are often synthesized through photoinitiated step-, chain-, and mixed-mode polymerizations, generating diverse network topologies and resultant material properties that depend on the underlying network connectivity. While many photocrosslinking reactions are available, few afford controllable connectivity of the hydrogel network. Herein, a versatile photochemical strategy is introduced for tuning the structure of poly(ethylene glycol) (PEG) hydrogels using macromolecular monomers functionalized with maleimide and styrene moieties. Hydrogels are prepared along a gradient of topologies by varying the ratio of step-growth (maleimide dimerization) to chain-growth (maleimide-styrene alternating copolymerization) network-forming reactions. The initial PEG content and final network physical properties (e.g., modulus, swelling, diffusivity) are tailored in an independent manner, highlighting configurable gel mechanics and reactivity. These photochemical reactions allow high-fidelity photopatterning and 3D printing and are compatible with 2D and 3D cell culture. Ultimately, this photopolymer chemistry allows facile control over network connectivity to achieve adjustable material properties for broad applications.

Facile Physicochemical Reprogramming of PEG-Dithiolane Microgels.

Granular biomaterials have found widespread applications in tissue engineering, in part because of their inherent porosity, tunable properties, injectability, and 3D printability. However, the assembly of granular hydrogels typically relies on spherical microparticles and more complex particle geometries have been limited in scope, often requiring templating of individual microgels by microfluidics or in-mold polymerization. Here, we use dithiolane-functionalized synthetic macromolecules to fabricate photopolymerized microgels via batch emulsion, and then harness the dynamic disulfide crosslinks to rearrange the network. Through unconfined compression between parallel plates in the presence of photoinitiated radicals, we transform the isotropic microgels are transformed into disks. Characterizing this process, we find that the areas of the microgel surface in contact with the compressive plates are flattened while the curvature of the uncompressed microgel boundaries increases. When cultured with C2C12 myoblasts, cells localize to regions of higher curvature on the disk-shaped microgel surfaces. This altered localization affects cell-driven construction of large supraparticle scaffold assemblies, with spherical particles assembling without specific junction structure while disk microgels assemble preferentially on their curved surfaces. These results represent a unique spatiotemporal process for rapid reprocessing of microgels into anisotropic shapes, providing new opportunities to study shape-driven mechanobiological cues during and after granular hydrogel assembly.

Outcomes of Investigating T Wave Inversion With Echocardiography in an Unselected Young Male Preparticipation Cohort.

BACKGROUND Electrocardiography (ECG) may be performed as part of preparticipation sports screening. Recommendations on screening of athletes to identify individuals with previously unrecognized cardiac disease are robust; however, data guiding the preparticipation screening of unselected populations are scarce. T wave inversion (TWI) on ECG may suggest an undiagnosed cardiomyopathy. This study aims to describe the prevalence of abnormal TWI in an unselected young male cohort and the outcomes of an echocardiography-guided approach to investigating these individuals for structural heart diseases, focusing on the yield for cardiomyopathies. METHODS AND RESULTS Consecutive young male individuals undergoing a national preparticipation cardiac screening program for 39 months were studied. All underwent resting supine 12-lead ECG. Those manifesting abnormal TWI, defined as negatively deflected T waves of at least 0.1 mV amplitude in any 2 contiguous leads, underwent echocardiography. A total of 69 714 male individuals with a mean age of 17.9±1.1 years were studied. Of the individuals, 562 (0.8%) displayed abnormal TWI. This was most frequently observed in the anterior territory and least so in the lateral territory. A total of 12 individuals (2.1%) were diagnosed with a cardiomyopathy. Cardiomyopathy diagnoses were significantly associated with deeper maximum TWI depth and the presence of abnormal TWI in the lateral territory, but not with abnormal TWI in the anterior and inferior territories. No individual presenting with TWI restricted to solely leads V1 to V2, 2 inferior leads or both was diagnosed with a cardiomyopathy. CONCLUSIONS Cardiomyopathy diagnoses were more strongly associated with certain patterns of abnormal TWI. Our findings may support decisions to prioritize echocardiography in these individuals.

Validating the Centre of Excellence on Longevity Self-AdMinistered (CESAM) Questionnaire: An Online Self-Reported Tool for Frailty Assessment of Older Adults.

OBJECTIVES: Subjective health measures are often used to assess frailty, but the validity of self-reported online tools to identify frailty remains to be established. We aimed to assess concurrent, known-groups, convergent and predictive validity of the Centre of Excellence on Longevity Self-AdMinistered (CESAM) questionnaire for frailty assessment of older adults in an outpatient setting. DESIGN: Cross-sectional analysis of 120 participants. SETTING AND PARTICIPANTS: Participants of age ≥65 were recruited from an outpatient geriatric clinic. Individuals who had severe neurological, cognitive, or motor deficits were excluded. METHODS: We assessed concurrent validity with area under receiver operating characteristic curve (AUC) against the Frailty Index (FI) and Clinical Frailty Scale (CFS). We analyzed known-groups validity between CESAM scores with frailty status (CFS and FI), Modified Barthel Index (MBI), and modified Chinese Mini-Mental State Examination (mCMMSE) using 1-way analysis of variance. We evaluated convergent validity using correlations with MBI, the Lawton index, mCMMSE, and Geriatric Depression Scale (GDS). Associations between CESAM-identified frailty for clinician-diagnosed geriatric syndromes, and health-related quality of life (HRQoL) was analyzed using regression analysis. RESULTS: The CESAM questionnaire demonstrated excellent diagnostic performance for frailty using FI ≥0.25 (AUC = 0.88; 95% CI: 0.82-0.94; P < .001) and CFS ≥4 (AUC = 0.78; 95% CI: 0.68-0.88; P < .001). CESAM scores increased significantly with increasing frailty (both CFS and FI), lower MBI, and lower mCMMSE scores (all P < .001), indicating concurrent validity. The moderate-good correlation of CESAM scores with MBI (r = -0.61; P < 0.001), Lawton Index (r = -0.54; P < .001), mCMMSE (r = -0.53; P < .001) and GDS (r = 0.58; P < .001) supports convergent validity. Using a cutoff of ≥8 for frailty identification, CESAM-identified frailty was associated with cognitive impairment (OR = 3.7; 95% CI: 1.7-8.2; P = .001) depression (OR = 4.0; 95% CI: 1.7-9.6; P = .002), falls (OR = 3.1; 95% CI: 1.2-8.2; P = .021) and poorer HRQoL (ß = -0.1; 95% CI: -0.2 to -0.02; P = .017). CONCLUSION AND IMPLICATIONS: Our results support the validity of an online self-reported tool to identify frailty and geriatric syndromes in an outpatient setting, an approach that is potentially applicable for remote screening of frailty.

Use of carbonated water in reduction of adjacent gastric activity in 456 consecutive technetium-99m myocardial perfusion imaging studies.

BACKGROUND: Small, observational trials have suggested a reduction in adjacent gastric activity with ingestion of soda water in myocardial perfusion imaging (MPI). We report our findings prior to and after implementation of soda water in 467 consecutive MPI studies. METHODS: Consecutive MPI studies performed at a high-volume facility referred for vasodilator (VD) or exercise treadmill testing (ETT) were retrospectively reviewed before and after implementation of the soda water protocol. Patients undergoing the soda water protocol received 100 ml of soda water administered 30 min prior to image acquisition and after stress. Studies were performed using a same day rest/stress protocol. Incidence of adjacent gastric activity, diaphragmatic attenuation, stress and rest perfusion defects, and major adverse cardiovascular events (MACE) outcomes defined as death, myocardial infarction, stroke, reevaluation for chest pain, and late revascularization (>90 days from MPI) were abstracted using International Classification of Diseases, Ninth Revision (ICD-9) search. RESULTS: Two hundred and eighteen studies were performed prior to implementation of the soda water protocol and 249 studies were performed with the use of soda water. Baseline demographic data were equal between the groups with the exception of more patients undergoing VD stress receiving soda water (p < 0.001). Soda water was not associated with a decreased incidence of adjacent gastric activity with stress (54.7% versus 61.9% with no soda water, p = 0.129) or rest (68.6% versus 69.5% with no soda water, p = 0.919) imaging. Less adjacent gastric activity was observed with patients undergoing ETT who received soda water (42.5% versus 56.9% with no soda water, p = 0.031), but no difference was observed between the groups with VD stress (69.0% versus 68.1% with no soda water, p = 1.000). CONCLUSION: The use of soda water prior to technetium-99m MPI was associated with lower rates of adjacent gastric activity only in patients undergoing ETT stress but not rest or VD stress. This differs from previously published data.

Critical ostial left main and right coronary artery stenosis secondary to takayasu arteritis in a young female simulating pulmonary embolism at presentation.

A 28-year-old Caucasian female presented to the Emergency Department (ED) with sudden-onset chest pain. Thirty-six hours earlier, she was diagnosed with a pulmonary embolism, for which anticoagulation was started. Evaluation was significant for atrial fibrillation, elevated cardiac biomarkers, and echocardiography demonstrating a new wall motion abnormality. Symptoms resolved with spontaneous conversion to normal sinus rhythm and the patient was initiated on intravenous heparin and eptifibatide, followed by admission. Shortly after admission, the patient experienced recurrent chest pain with dynamic electrocardiographic (ECG) changes that prompted emergent cardiac catheterization. Prior to angiography, the patient developed pulseless cardiac arrest for which advanced cardiac lifesaving (ACLS) techniques were initiated. Coronary angiography showed critical ostial stenosis of the left main coronary artery. Despite transient periods of hemodynamic stability after successful stenting, the patient decompensated and was pronounced dead. Postmortem findings were consistent with Takayasu arteritis (TA). TA involving the coronary arteries is rare, presenting in fewer than 5% of cases. Diagnosis relies heavily on clinical suspicion. For our patient, dynamic ECG changes with wall motion abnormalities visible on echocardiography prompted diagnostic/therapeutic cardiac catheterization and stenting. Management involves high-dose systemic steroid therapy. However, due to recurrence of disease and adverse effects of prolonged steroid use, additional disease-modifying agents such as methotrexate, azathioprine, or cyclophosphamide may be used. With appropriate therapy, short-term prognosis is favorable. This case underlines the importance of having a high clinical suspicion for TA in the young female population with ischemic symptoms in order to allow early diagnosis in hopes of preventing further complications.