Contrast Changes Research Articles

Recent Early-Spring Drying Trend over Southern China Associated with Changes in the Zonal Thermal Contrast over the Pacific

Abstract Southern China has experienced a discernible early-spring drying trend in recent decades. This drying trend is a direct result of a severe deficiency of water vapor, which is induced by local descent anomalies and strong anomalous northerlies from the northwestern Pacific. The predominant anomalous northerlies are directly associated with two anomalous warm highs over the North Pacific (NPH) and East Asia (EAH), respectively. Anomalous easterlies along the southern edge of the NPH divert southwestward over southern Japan and form a branch of the northerlies, which merges into strong northerlies east of the EAH to construct the prevalent and deep northerly anomalies along the coast of East Asia. The NPH is related to changes in the zonal contrast of the Pacific sea surface temperature (SST-Tri), whose linear trend is dominated by warming in the western Pacific. The change in SST-Tri causes more precipitation in the tropical North Pacific, where strong ascent occurs and further facilitates robust descent over the extratropical North Pacific, facilitating the formation of the NPH. The EAH results from the interaction of tropical and higher latitudinal forcing in the context of global warming. On the one hand, enhanced precipitation over the Maritime Continent associated with the change in SST-Tri induces descent anomalies of the EAH over southern China via a local Hadley cell circulation. On the other hand, a “positive–negative–positive” tripolar tendency over the North Atlantic forces a wave train, which propagates eastward, becomes intensified over the Ural Mountains, and then moves farther eastward to affect the EAH. In addition, changes in SST-Tri can also modulate the tripole pattern over the North Pacific to further contribute to the EAH.

Confidence and Uncertainty in Simulating Tropical Cyclone Long-Term Variability Using the CMIP6-HighResMIP

Abstract Confidence and uncertainty issues of simulations were seldom evaluated in previous studies although the climate models are widely used. This study evaluates the performance of the CMIP6-HighResMIP simulations in presenting long-term variability of tropical cyclone (TC) genesis frequency (TCGF) and track density (TCTD) and quantifies the relative contributions of internal and external forcing to TC activities during the 1950–2014. There is overall poor model performance in simulating long-term changes in TC activities over the Northern Hemisphere, including interdecadal variabilities and long-term linear trends. The simulated long-term changes in TCGF and TCTD over the eastern North Pacific (ENP) in six high-resolution models show opposite characteristics to the observations. Moreover, most models cannot capture the variabilities of TCGF and TCTD over the western part of the western North Pacific (WNP) and northern part of the North Atlantic (NA). However, these models show a high degree of confidence in reproducing the interdecadal variabilities and linear trends of TCGF and TCTD over the eastern part of the WNP and the tropical NA. Quantitative evaluations further show that there are the opposite relative contributions of long-term climate variabilities to TCGF and TCTD changes over the ENP between the observations and the multimodel ensemble mean, followed by large model biases over the western WNP and the northern NA, but relatively consistent contributions over the southern NA and the Caribbean. These results help us cope with contrasting and consistent future TC changes among the model projections. Significance Statement While climate models have been widely used to project future changes in tropical cyclone (TC) activity, few studies have examined to what extent we can trust these model projections. We used the CMIP6-HighResMIP simulations to quantify the model biases in presenting TC activity, and evaluate the relative contributions of internal and external forcing to TC activities. In general, the HighResMIP has large discrepancies in representing longer-term climate variability of TC activity. However, the models can capture well TC activity over the eastern part of the western North Pacific and tropical Atlantic, which is attributed to good performance of models in reproducing the relationship between long-term climate variabilities beyond interannual scale and TC activity. These results highlight confidence and uncertainty in future TC changes among the model projections.

Optimizing habitat connectivity among macaque populations in modern Japan

AbstractNationwide depopulation in modern Japan has led to contrasting changes over the last half‐century: shrinking human communities and recovering populations of Japanese macaques (Macaca fuscata). These changes have triggered macaque damage to public livelihoods, often resulting in decision‐making directed toward strictly regulating macaque populations. To optimize conservation interventions required today, we aimed to identify macaque habitats with conservation priorities to enhance population connectivity. To quantify the current population connectivity, we conducted a least‐cost path analysis by assigning an inverse of habitat suitability as resistance. For this, we collected geo‐information on home ranges of 2288 troops, accounting for >70% of the total number of troops in Japan. Moreover, we composed a minimum spanning tree using least‐cost paths to provide optimal population connectivity. Consequently, the modeled resistance showed that, although human‐induced barriers (i.e., flat areas where people frequently reside) and geographical barriers (i.e., alpine regions >1500 m above sea level) had the highest dispersal cost, macaques presented a high plasticity in the occupation of different forest types. The minimum spanning tree, composed of 77 modeled corridors, detected the vulnerability of population connectivity in western Japan and assigned conservation priorities to these isolated populations to preserve the stepping‐stone paths of macaque movement.

Retrenchment of Wisconsin’s Well Woman Program and changes in insurance coverage around the Affordable Care Act

Since before the Affordable Care Act (ACA), states have partnered with the National Breast and Cervical Cancer Early Detection Program (NBCCEDP) to support access to cancer screening and treatment for uninsured/underinsured women. The Wisconsin Well Woman Program (WWWP) was one such program, supporting low-income women across the state. With ACA introduction, Wisconsin substantially downsized/restructured the WWWP, expecting the reduction in services to be offset by the rise in ACA-provided insurance coverage. This study assesses whether retrenchment in the WWWP following the ACA indeed prompted a differential rise in insurance coverage among the program’s target population. We use a difference-in-differences (DID) design to contrast changes in county-level, target-population insurance rates, over 2008–2018, in Wisconsin counties previously most served by the WWWP vs those least served, adjusting for systematic differences across counties, including pre-policy trends. Pre-ACA (2011–2013), most-served counties had lower insurance rates by 2.5 percentage points (pp) than least-served counties; WWWP services likely compensated for some of that gap. In 2014–2015, along with WWWP’s steep contraction, insurance rates rose sharply across all counties. Our primary DID analysis and event study suggest that WWWP contraction might have differentially driven more insurance take-up in most-served counties, by 1.88 pp [95 % Confidence Interval: 0.23,3.54], thus narrowing the pre-ACA gap. Sensitivity analyses suggest much smaller gains. Notwithstanding such potential insurance gains following program contraction, continued support for care navigation and coordination remain necessary to truly meet the needs of the vulnerable women previously served by the WWWP and similar programs across states.

Hydration Structure at the Calcite-Water (10.4) Interface in the Presence of Rubidium Chloride.

Solid-liquid interfaces are of significant importance in a multitude of geochemical and technological fields. More specifically, the solvation structure plays a decisive role in the properties of the interfaces. Atomic force microscopy (AFM) has been used to resolve the interfacial hydration structure in the presence and absence of ions. Despite many studies investigating the calcite-water interface, the impact of ions on the hydration structure at this interface has rarely been studied. Here, we investigate the calcite-water interface at various concentrations (ranging from 0 to 5 M) of rubidium chloride (RbCl) using three-dimensional atomic force microscopy (3D AFM). We present molecularly resolved images of the hydration structure at the interface. Interestingly, the characteristic pattern of the hydration structure appears similar regardless of the RbCl concentration. The presence of the ions is detected in an indirect manner by more frequent contrast changes and slice displacements.

Solitary Fibrous Tumor of Orbit: Changes of Tumor Size and Tumor Contrast Enhancement

Purpose: To report a case of solitary fibrous tumor of the orbit in a patient with changes in tumor size and contrast enhancement.Case summary: A 64-year-old male patient presented with dizziness, discomfort on eye movement, anosmia, and proptosis. Orbital computed tomography showed an enhancing mass in the right extraconal space, lateral to the medial rectus and inferior to the superior oblique muscle. The mass appeared to be a cavernous hemangioma and the patient was monitored for changes in mass size and eye movements. After 24 months of follow-up, the mass size and symptoms of right eyelid swelling, proptosis, and diplopia had increased. Excision and biopsy of the mass were performed under general anesthesia. The biopsy confirmed that the mass was a solitary fibrous tumor. The postoperative period was uneventful and no recurrence was observed at 6 months after surgery.Conclusions: Solitary fibrous tumor is a soft tissue tumor that rarely occurs in the orbit, and should be considered in cases with an intraorbital mass accompanied by increased size and changes in contrast enhancement on imaging.

Understanding Changes in the Tropical Circulation under Global Warming Using a Cloud-Resolving Model and a Conceptual Model

Abstract A cloud-resolving model (CRM) is used to investigate how a prototype tropical circulation driven by a sea surface temperature (SST) contrast changes in a warmer climate. The CRM is used to simulate a region of the atmosphere with a positive SST anomaly, and the large-scale circulation in this region is represented using the weak temperature gradient (WTG) and damped gravity wave (DGW) parameterizations, where the large-scale vertical velocity within the domain is related to the deviation of the simulated density profile from a reference profile representative of the tropical mean state. The behavior of the circulation in response to an increase in SST of both the domain and reference state (i.e., uniform warming) is examined. While the vertical velocity shows an increase in its maximum strength with warming, its value in the lower to midtroposphere decreases. Since the water vapor concentration is largest in the lower troposphere, this leads to a dynamic weakening of precipitation under warming. To understand these results, a simple model for the thermodynamic structure of a convecting atmosphere based on a bulk entraining plume is employed. The model uses a fixed entrainment rate and the relative humidity profiles from the CRM to predict the temperature profiles of the domain and reference state. The vertical velocity profiles calculated from these predicted temperature profiles reproduce important aspects of those simulated with the CRM. This simple modeling framework reveals that the effect of entrainment is crucial to understanding the dynamic response of precipitation to warming, providing a stepping stone to understanding the factors driving changes to the tropical precipitation distribution in a future warmer climate.

Enzymatic degradation of bacterial cellulose derived carbon nanofibers (BC-CNF) by myeloperoxidase (MPO): Performance evaluation for biosensing

Myeloperoxidase (MPO) is a promising biomarker for early warning of incidence of cardiovascular diseases (CVDs). Among various sensing mechanisms for detection and quantification of MPO, enzymatic degradation of carbon nanoparticles (CNPs) in presence of MPO has unique advantages such as visual change in optical contrast of sample without requiring additional probe chemicals or reagents. While the degradation of various forms of CNPs (including carbon nanotubes and graphene oxide) due to MPO has been reported in literature, the degradation is typically very slow, resulting in response times on the order of multiple hours, and thus presents a significant limitation for CVD diagnosis. Besides, the extent of degradation is highly sensitive to substrate uniformity, necessitating complicated synthesis processes to obtain pristine CNPs. In this work, we have characterized the enzymatic degradation of bacterial cellulose derived carbon nanofibers (BC-CNF) due to MPO in vitro and explored the feasibility of realizing a BC-CNF colorimetric biosensor for measuring MPO activity. The degradation of BC-CNFs is thoroughly characterized using SEM, TEM, Raman and UV–Vis spectroscopy. We report that carboxylic group functionalized BC-CNFs demonstrate noticeable change in optical contrast due to degradation with clinically relevant concentrations of MPO in approximately 1h, and hold great promise for realizing low-cost biosensors for MPO.

Satellite Observational Evidence of Contrasting Changes in Northern Eurasian Wildfires from 2003 to 2020

Wildfires play a critical role in re-shaping boreal ecosystems and climate. It was projected that, owing to the Arctic amplification, boreal wildfires would become more frequent and severe in the coming decades. Although provoking concern, the spatiotemporal changes in boreal wildfires remain unclear, and there are substantial inconsistencies among previous findings. In this study, we performed a comprehensive analysis to determine the spatiotemporal changes in wildfires over Northern Eurasia (NEA) from 2003 to 2020 using a reconstructed Moderate Resolution Imaging Spectroradiometer (MODIS) active fire product. We found that wildfires in NEA exhibited contrasting changes in different latitudinal zones, land cover types, and seasons from 2003 to 2020. Cropland wildfires, mainly distributed at low latitudes (50–60°N), considerably decreased by 81% during the study period. Whereas forest wildfires ignited at high latitudes (north of 60°N) have nearly tripled (increasing at rate of 11~13% per year) during the past two decades. The southwestern and northeastern NEA regions exhibited contrasting patterns of wildfire changes. The active fire counts in the southwestern NEA decreased by 90% at a rate of 0.29(±0.12) × 105 per year, with cropland fires contributing to ~66% of the decrease. However, the fire counts in the northeastern NEA increased by 292% at a rate of 0.23(±0.12) × 105 per year, with boreal forests contributing to ~97% of the increase. It is worth noting that the contrasting changes in wildfires during the past two decades have led to significant structural alternation in the NEA wildfire composition. Forest fires, contributing over 60% of the total fire counts in NEA nowadays, have become the predominant component of the NEA wildfires. The contrasting changes in NEA wildfires imply that more forest fires may emerge in far northern regions of the North Hemisphere as the Arctic becomes progressively warmer in the coming decades. As wildfires continue to increase, more gases and aerosols would be released to the atmosphere and cause considerable feedback to the Arctic climate. The increased wildfire-related climate feedbacks should, therefore, be seriously considered in climate models and projections.

Alzheimer’s disease classification based on graph kernel SVMs constructed with 3D texture features extracted from MR images

Alzheimer’s disease (AD) is a neurodegenerative disease characterized by cognitive and behavioral impairment that significantly interferes with social and occupational functioning. Mild cognitive impairment (MCI) is a relatively broad clinical condition involving a slight memory deficit, which in many cases represents a transitional state between a cognitively normal (CN) condition and AD. Structural magnetic resonance (sMR) imaging has been widely used in studies related to AD because it provides images with excellent anatomical details and information about structural and contrast changes induced by the disease in the brain. Many published studies restrict their analysis to a few particular regions of the brain and search for structural changes caused by the disease. Recent studies start looking for new AD biomarkers using multiple brain regions and focusing on subtle texture changes in the image. Therefore, this study proposes a new technique for MR image classification in AD diagnosis using graph kernels constructed from texture features extracted from sMR images. In our method, we first segment the MR brain images into multiple regions with the FreeSurfer. Then, we extract 22 texture features using three methods and define the graph-node attributes as the probability distributions of the extracted features. Next, for each texture feature, we build a graph and define its edge weights as the distances between pairs of node attributes using three distance metrics. After that, we use a threshold-based approach for graph edges removal and create the graph-kernels matrices. Finally, we perform image classification using Support Vector Machines (SVMs) with two graph-kernels. Results of our method have shown better performances for the CN×AD (AUC = 0.92) and CN×MCI (AUC = 0.81) classifications, and worse for the MCI×AD case (AUC = 0.78). This trend is consistent with other published results and makes sense if we consider the concept of Alzheimer’s disease continuum from pathophysiological, biomarker and clinical perspectives. Besides allowing the use of different texture attributes for the diagnosis of Alzheimer’s, our method uses the graph-kernel approach to represent texture features from different regions of the brain image, which considerably facilitates the image classification task via SVMs. Our results were promising when compared to the state-of-the-art in graph-based AD classification.

Molecular Glass Resists Based on Tetraphenylsilane Derivatives: Effect of Protecting Ratios on Advanced Lithography

A series of t-butyloxycarbonyl (t-Boc) protected tetraphenylsilane derivatives (TPSi-Bocx, x = 60, 70, 85, 100%) were synthesized and used as resist materials to investigate the effect of t-Boc protecting ratio on advanced lithography. The physical properties such as solubility, film-forming ability, and thermal stability of TPSi-Bocx were examined to assess the suitability for application as candidates for positive-tone molecular glass resist materials. The effects of t-Boc protecting ratio had been studied in detail by electron beam lithography. The results suggest that the TPSi-Bocx resist with different t-Boc protecting ratios exhibit a significant change in contrast, pattern blur, and the density of bridge defect. The TPSi-Boc70% resist achieves the most excellent patterning capability. The extreme ultraviolet (EUV) lithography performance on TPSi-Boc70% was evaluated by using the soft X-ray interference lithography. The results demonstrate that the TPSi-Boc70% resist can achieve excellent patterning capability down to 20 nm isolated lines at 8.7 mJ/cm2 and 25 nm dense lines at 14.5 mJ/cm2. This study will help us to understand the relationship between the t-Boc protecting ratio and the patterning ability and supply useful guidelines for designing molecular resists.

Rational Control of Off-State Heterogeneity in a Photoswitchable Fluorescent Protein Provides Switching Contrast Enhancement.

Reversibly photoswitchable fluorescent proteins are essential markers for advanced biological imaging, and optimization of their photophysical properties underlies improved performance and novel applications. Here we establish a link between photoswitching contrast, one of the key parameters that dictate the achievable resolution in nanoscopy applications, and chromophore conformation in the non-fluorescent state of rsEGFP2, a widely employed label in REversible Saturable OpticaL Fluorescence Transitions (RESOLFT) microscopy. Upon illumination, the cis chromophore of rsEGFP2 isomerizes to two distinct off-state conformations, trans1 and trans2, located on either side of the V151 side chain. Reducing or enlarging the side chain at this position (V151A and V151L variants) leads to single off-state conformations that exhibit higher and lower switching contrast, respectively, compared to the rsEGFP2 parent. The combination of structural information obtained by serial femtosecond crystallography with high-level quantum chemical calculations and with spectroscopic and photophysical data determined in vitro suggests that the changes in switching contrast arise from blue- and red-shifts of the absorption bands associated to trans1 and trans2, respectively. Thus, due to elimination of trans2, the V151A variants of rsEGFP2 and its superfolding variant rsFolder2 display a more than two-fold higher switching contrast than their respective parent proteins, both in vitro and in E. coli cells. The application of the rsFolder2-V151A variant is demonstrated in RESOLFT nanoscopy. Our study rationalizes the connection between structural and photophysical chromophore properties and suggests a means to rationally improve fluorescent proteins for nanoscopy applications.

Exposing digital image forgeries from statistical footprints

Photo attack and anti-forgery techniques have been on the rise in the internet age. Attackers conceal tampering by applying anti-forgery techniques, such as contrast enhancement. Digital image forensics concerns with detecting traces of these operations subjected upon the image. In this work, a novel Anti-Forensic Contrast Enhancement Detector (AFCED) scheme has been proposed to assess contrast changes from anti-forensic digital images. The proposed model is based on the underlying observation that, with repeated gamma correction, the rate of attaining contrast saturation in normal images is greater than already contrast-improved images. Thus, we employ skewness and kurtosis of the gamma-corrected second-order derivative histograms as features to distinguish normal images from contrast-enhanced images. These features are robustly classified on a Support Vector Machine. The proposed model achieved 97.40% F1-score and 98.18% sensitivity on the Dresden and Wikiart image databases on-par with state-of-the-art results.

Abstract P1090: Polycystin-1 Regulates Calcium Handling And Contractility In Human IPSC-derived Ventricular Cardiomyocytes

Mutations in polycystin-1 (PC1) cause 85% of autosomal dominant polycystic kidney disease cases. This disease is characterized by progressive renal disease and multiple cardiovascular alterations. Evidence suggests that cardiovascular disease precedes the onset of renal failure. We recently demonstrated that PC1 ablation shortens cardiomyocyte action potential, decreases Ca 2+ transient amplitude, and reduces contractility in adult cardiomyocytes isolated from cardiomyocyte-specific PC1 knock-out mice compared to control mice. Alterations in Ca 2+ cycling in PC1-deficient cardiomyocytes were demonstrated to be due to action potential duration shortening and impaired sarcoendoplasmic reticulum ATPase activity. However, mouse and human cardiomyocytes have considerable differences in their action potential shapes and the ion channels involved. It remains unknown whether PC1 regulates these events in human cardiomyocytes. Here, we sought to investigate whether PC1 regulates excitation-contraction coupling in human ventricular cardiomyocytes. We differentiated commercially available human-induced pluripotent stem cell lines (hiPSC) into ventricular cardiomyocytes (hiPSC-CM) using published protocols (measurements were performed 60-90 days after differentiation). We developed a protocol to simultaneously measure action potentials (FluoVolt), intracellular Ca 2+ (Calbryte-590) and contractility using the IonOptix algorithm to detect changes in contrast as contractility measurements. PC1 ablation using siRNA decreased action potential duration and impaired Ca 2+ transients and contractility in hiPSC-CMs. Because hiPSC-CMs have several limitations due to their immature state, we employed a well-validated method to improve their maturation that utilizes a Matrigel mattress and hormone supplementation (dexamethasone; Dexa / thyroid hormone; T3; PMID: 28974554; developed by Dr. Bjorn Knollmann’s lab). Using the Matrigel mattress/Dexa/T3 technique, we increased hiPSC-CM maturation measured as follows: cardiomyocytes were oriented and contracted in the longitudinal axis, ryanodine receptor type 2 and alpha-actinin localized with a striated pattern, exhibited robust inward K + rectifier currents (I K1 ) and fired action potentials that resemble human adult cardiomyocytes. In this model, PC1 knockdown also decreased action potential duration and impaired Ca 2+ transients and decreased contractility measured as fractional shortening. Altogether, this evidence shows for the first time that PC1 regulates human cardiomyocyte physiology and suggests that cardiac alterations in patients with autosomal dominant polycystic kidney disease may emerge as a result of impaired cardiomyocyte contractile function.

New advances in medical imaging technology for the evaluation of anthracycline-induced cardiotoxicity.

New advances in medical imaging technology for the evaluation of anthracycline-induced cardiotoxicity.

Applicability limits of the end face fiber-optic gas concentration sensor, based on Fabry-Perot interferometer

The mathematical model of the fiber-optic sensor for gas concentration analysis is under study. The sensor is imple-mented as Fabry-Perot interferometer at the end face of the optical fiber by applying a thin polymer film, which permit-tivity depends on the tested gas concentration. It is shown, that a change in the properties of the optical fiber or the at-mosphere permittivity leads mainly to the spectrum contrast changing and does not change the period and the wave-length shift of its comb. The influence of the polymer film thickness, the environment temperature and humidity on the Fabry-Perot spectrum is analyzed. The necessity of using the temperature and humidity compensation sensors is shown. The method, which determines the permittivity in narrow and wide ranges basing on the comb period and the wave-length shift of Fabry-Perot reflection spectrum, is developed. The relative error of measuring the polymer film permit-tivity depending on the film thickness for three wavelength ranges (810−890, 1270−1350, and 1510−1590 nm) is esti-mated. The real achievable relative error in determining the polymer film permittivity is in 0.3–1% FSI, depending on the conditions of the experiment. The mathematical methods and practical recommendations are proposed.

Contrasting changes in fine-scale land use structure and summertime thermal environment in downtown Shanghai

• Changes in patterns of fine-scale land use structures and intensity of intra-SUHI were analyzed. • The associations between changes in land use structures and intensity of intra-SUHI were analyzed. • Comparison of two regression models quantifies the importance of interactions of the predictors. • PLSR models perform slightly better than RFR models, but their combined usage will perform better . Understanding the associations between fine-scale land use structures and the surface urban heat island effect within the cities (synonymously defined as intra-SUHI) is vital for decision-making on sustainable land development, UHI mitigation, and climate adaptation. Taking downtown Shanghai as a case, this study quantified the associations between the changes in land use structures (indicated by eleven metrics of urban morphology, land use composition, and urban green infrastructure) and the intensity of intra-SUHI (intra-SUHII) at the land parcel level. Two model types, including Type-1 models that merely consider the main effect of the factors, and Type-2 models that consider both the main effect and potential interactions, were employed for analysis. The performance of each model type was parallelly assessed using the partial least square regression (PLSR) and random forest regression (RFR) methods. Our results revealed that Type-2 models exhibited higher interpretation power (PLSR:55.604–55.887% and RFR:53.841–55.739%) than Type-1 models (PLSR:47.531–47.591% and RFR: 47.111–50.300%) for explaining the variance in parcel-level intra-SUHIIs. This finding indicated the non-negligible importance of potential interactions of the factors in determining the models' interpretation power. Our study can be generalizable to many large cities with similar climatological conditions.

Optimum conditions for deposition of amorphous WS2 thin films and changes in structure and optical properties during solid state crystallization

Transition metal dichalcogenides exhibit a unique properties, which make them interesting for fundamental studies and for applications in many fields of daily life. Here, we report on optimum conditions for deposition of amorphous stoichiometric WS2 thin films by (non-reactive) magnetron sputtering using a stoichiometric WS2 target and subsequent application of solid state crystallization of amorphous WS2 thin films for fabrication of crystalline WS2 over a large area. By ex-situ annealing of samples up to 1000 °C, we found that the optical contrast change occurs in two steps, which are separated by a plateau that exhibits a gradual increase in optical absorbance. We suggest that the dissociation of W–W homopolar bonds, associated with the transformation of 1T’ - like symmetry into 2H-like symmetry units, plays a key role in the first abrupt change in the optical properties of WS2 thin films between 300 and 400 °C while the formation of excitons occurred between 700 and 1000 °C is associated with crystallization, as confirmed by X-ray photoelectron spectroscopy, X-ray diffraction and Scanning electron microscopy studies.

Asia Pacific perspectives on the second year of the COVID-19 pandemic: A follow-up survey.

BackgroundThe Coronavirus disease 2019 (COVID‐19) pandemic is currently in its third year. This follow‐up survey was commissioned by the Asia Pacific Association of Allergy Asthma and Clinical Immunology (APAAACI) Task Force on COVID‐19 to compare and contrast changes in the epidemiology, clinical profile, therapeutics and public health measures of the pandemic in the Asia Pacific region.MethodsA questionnaire‐based survey comprising 32 questions was electronically sent out to all 15 member countries of APAAACI using Survey Monkey® from 1 December 2021 to 28 February 2022.ResultsSeventeen responses were received from 14/15 (93.4%) member countries and 3 individual members. Mild‐to‐moderate COVID‐19 predominated over severe infection, largely contributed by COVID‐19 vaccination programmes in the region. The incidence of vaccine adverse reactions in particular anaphylaxis from messenger ribonucleic acid (mRNA) vaccines was no longer as high as initially anticipated, although perimyocarditis remains a concern in younger males. Novel therapeutics for mild‐to‐moderate disease including neutralizing antibodies casirivimab/imdevimab (REGEN‐COV®) and sotrovimab (Xevudy®), anti‐virals Paxlovid® (nirmatrelvir and ritonavir) and Molnupiravir pre‐exposure prophylaxis for high‐risk persons with Tixagevimab and Cilgavimab (Evusheld) are now also available to complement established therapeutics (e.g., remdesivir, dexamethasone and baricitinib) for severe disease. In the transition to endemicity, public health measures are also evolving away from containment/elimination strategies.ConclusionsWith access to internationally recommended standards of care including public health preventive measures, therapeutics and vaccines among most APAAACI member countries, much progress has been made over the 2‐year period in minimizing the morbidity and mortality from COVID‐19 disease.

Estimation of a surface magnetization direction of thin cylinders by magnetooptical Kerr effect

Magneto-optical Kerr effect (MOKE) imaging is a versatile technique for probing a surface magnetization of magnetic materials. Here, we investigate the influence of the polarizers' rotation on the resulting magnetooptical contrast of thin magnetic wires with cylindrical geometry. Employing MOKE microscopy, we image the magnetooptical contrast change and quantify the contribution of the spatially curved cylindrical surface to the overall magnetic contrast. The calculated magnetooptical contrast difference for various extinction angles between polarizer and analyzer provide an estimation of the surface magnetization orientation at curved surfaces. The magnetooptical analysis scheme can be extended to other non-planar magnetic surfaces.