Protocol for a construct and clinical validation study of MyCog Mobile: a remote smartphone-based cognitive screener for older adults.

INTRODUCTION: Annual cognitive screening in older adults is essential for early detection of cognitive impairment, yet primary care settings face time constraints that present barriers to routine screening. A remote cognitive screener completed on a patient's personal smartphone before a visit has the potential to save primary care clinics time, encourage broader screening practices and increase early detection of cognitive decline. MyCog Mobile is a promising new remote smartphone-based cognitive screening app for primary care settings. We propose a combined construct and clinical validation study of MyCog Mobile. METHODS AND ANALYSIS: We will recruit a total sample of 300 adult participants aged 65 years and older. A subsample of 200 healthy adult participants and a subsample of 100 adults with a cognitive impairment diagnosis (ie, dementia, mild cognitive impairment, cognitive deficits or other memory loss) will be recruited from the general population and specialty memory care centres, respectively. To evaluate the construct validity of MyCog Mobile, the healthy control sample will self-administer MyCog Mobile on study-provided smartphones and be administered a battery of gold-standard neuropsychological assessments. We will compare correlations between performance on MyCog Mobile and measures of similar and dissimilar constructs to evaluate convergent and discriminant validity. To assess clinical validity, participants in the clinical sample will self-administer MyCog Mobile on a smartphone and be administered a Mini-Cog screener and these data will be combined with the healthy control sample. We will then apply several supervised model types to determine the best predictors of cognitive impairment within the sample. Area under the receiver operating characteristic curve, accuracy, sensitivity and specificity will be the primary performance metrics for clinical validity. ETHICS AND DISSEMINATION: The Institutional Review Board at Northwestern University (STU00214921) approved this study protocol. Results will be published in peer-reviewed journals and summaries provided to the study's funders.

Remote Self-Administration of Cognitive Screeners for Older Adults Prior to a Primary Care Visit: Pilot Cross-Sectional Study of the Reliability and Usability of the MyCog Mobile Screening App.

BACKGROUND: Routine cognitive screening is essential in the early detection of dementia, but time constraints in primary care settings often limit clinicians' ability to conduct screenings. MyCog Mobile is a newly developed cognitive screening system that patients can self-administer on their smartphones before a primary care visit, which can help save clinics' time, encourage broader screening practices, and increase early detection of cognitive decline. OBJECTIVE: The goal of this pilot study was to examine the feasibility, acceptability, and initial psychometric properties of MyCog Mobile. Research questions included (1) Can older adults complete MyCog Mobile remotely without staff support? (2) Are the internal consistency and test-retest reliability of the measures acceptable? and (3) How do participants rate the user experience of MyCog Mobile? METHODS: A sample of adults aged 65 years and older (N=51) self-administered the MyCog Mobile measures remotely on their smartphones twice within a 2- to 3-week interval. The pilot version of MyCog Mobile includes 4 activities: MyFaces measures facial memory, MySorting measures executive functioning, MySequences measures working memory, and MyPictures measures episodic memory. After their first administration, participants also completed a modified version of the Simplified System Usability Scale (S-SUS) and 2 custom survey items. RESULTS: All participants in the sample passed the practice items and completed each measure. Findings indicate that the Mobile Toolbox assessments measure the constructs well (internal consistency 0.73 to 0.91) and are stable over an approximately 2-week delay (test-retest reliability 0.61 to 0.71). Participants' rating of the user experience (mean S-SUS score 73.17, SD 19.27) indicated that older adults found the usability of MyCog Mobile to be above average. On free-response feedback items, most participants provided positive feedback or no feedback at all, but some indicated a need for clarity in certain task instructions, concerns about participants' abilities, desire to be able to contact a support person or use in-app technical support, and desire for additional practice items. CONCLUSIONS: Pilot evidence suggests that the MyCog Mobile cognitive screener can be reliably self-administered by older adults on their smartphones. Participants in our study generally provided positive feedback about the MyCog Mobile experience and rated the usability of the app highly. Based on participant feedback, we will conduct further usability research to improve support functionality, optimize task instructions and practice opportunities, and ensure that patients feel comfortable using MyCog Mobile. The next steps include a clinical validation study that compares MyCog Mobile to gold-standard assessments and tests the sensitivity and specificity of the measures for identifying dementia.

Primary care detection of cognitive impairment leveraging health and consumer technologies in underserved US communities: protocol for a pragmatic randomised controlled trial of the MyCog paradigm.

INTRODUCTION: Early identification of cognitive impairment (CI), including Alzheimer's disease and related dementias (ADRD), is a top public health priority. Yet, CI/ADRD is often undetected and underdiagnosed within primary care settings, and in health disparate populations. The MyCog paradigm is an iPad-based, self-administered, validated cognitive assessment based on the National Institutes of Health (NIH) Toolbox Cognition Battery and coupled with clinician decision-support tools that is specifically tailored for CI/ADRD detection within diverse, primary care settings. METHODS AND ANALYSIS: We will conduct a two-arm, primary care practice-randomised (N=24 practices; 45 257 active patients at the proposed practices), pragmatic trial among geographically diverse Oak Street Health sites to test the effectiveness of the MyCog paradigm to improve early detection CI/ADRD among low socioeconomic, black and Hispanic older adults compared with usual care. Participating practices randomised to the intervention arm will impart the MyCog paradigm as a new standard of care over a 3-year implementation period; as the cognitive component for Annual Wellness Visits and for any patient/informant-reported or healthcare provider-suspected cognitive concern. Rates of detected (cognitive test suggesting impairment) and/or diagnosed (relevant International Classification of Diseases-9/10 [ICD-9/10] code) cognitive deficits, impairments or dementias including ADRD will be our primary outcome of study compared between arms. Secondary outcomes will include ADRD severity (ie, mild or later stage), rates of cognitive-related referrals and rates of family member or caregiver involvement in ADRD care planning. We will use generalised linear mixed models to account for clustered study design. Secondary models will adjust for subject, clinic or visit-specific characteristics. We will use mixed-methods approaches to examine fidelity and cost-effectiveness of the MyCog paradigm. ETHICS AND DISSEMINATION: The Institutional Review Board at Advarra has approved the study protocol (Pro00064339). Results will be published in peer-reviewed journals and summaries will be provided to the funders of the study. TRIAL REGISTRATION NUMBER: NCT05607732.

Remote Cognitive Screening Of Healthy Older Adults for Primary Care With the MyCog Mobile App: Iterative Design and Usability Evaluation.

BACKGROUND: Annual cognitive screening in adults aged >65 years can improve early detection of cognitive impairment, yet less than half of all cases are identified in primary care. Time constraints in primary care settings present a major barrier to routine screening. A remote cognitive screener completed on a patient's own smartphone before a visit has the potential to save primary care clinics time, encourage broader screening practices, and increase early detection of cognitive decline. OBJECTIVE: We described the iterative design and proposed the implementation of a remote cognitive screening app, MyCog Mobile, to be completed on a patient's smartphone before an annual wellness visit. The research questions were as follows: What would motivate primary care clinicians and clinic administrators to implement a remote cognitive screening process? How might we design a remote cognitive screener to fit well with existing primary care workflows? What would motivate an older adult patient to complete a cognitive screener on a smartphone before a primary care visit? How might we optimize the user experience of completing a remote cognitive screener on a smartphone for older adults? METHODS: To address research questions 1 and 2, we conducted individual interviews with clinicians (n=5) and clinic administrators (n=3). We also collaborated with clinic administrators to create user journey maps of their existing and proposed MyCog Mobile workflows. To address research questions 3 and 4, we conducted individual semistructured interviews with cognitively healthy older adults (n=5) and solicited feedback from a community stakeholder panel (n=11). We also tested and refined high-fidelity prototypes of the MyCog Mobile app with the older adult interview participants, who rated the usability on the Simplified System Usability Scale and After-Scenario Questionnaire. RESULTS: Clinicians and clinic administrators were motivated to adopt a remote cognitive screening process if it saved time in their workflows. Findings from interviews and user journey mapping informed the proposed implementation and core functionality of MyCog Mobile. Older adult participants were motivated to complete cognitive screeners to ensure that they were cognitively healthy and saw additional benefits to remote screening, such as saving time during their visit and privacy. Older adults also identified potential challenges to remote smartphone screening, which informed the user experience design of the MyCog Mobile app. The average rating across prototype versions was 91 (SD 5.18) on the Simplified System Usability Scale and 6.13 (SD 8.40) on the After-Scenario Questionnaire, indicating above-average usability. CONCLUSIONS: Through an iterative, human-centered design process, we developed a viable remote cognitive screening app and proposed an implementation strategy for primary care settings that was optimized for multiple stakeholders. The next steps include validating the cognitive screener in clinical and healthy populations and piloting the finalized app in a community primary care clinic.

Coeliac Disease Pathogenesis: The Uncertainties of a Well-Known Immune Mediated Disorder.

Coeliac disease is a common small bowel enteropathy arising in genetically predisposed individuals and caused by ingestion of gluten in the diet. Great advances have been made in understanding the role of the adaptive immune system in response to gluten peptides. Despite detailed knowledge of these adaptive immune mechanisms, the complete series of pathogenic events responsible for development of the tissue lesion remains less certain. This review contributes to the field by discussing additional mechanisms which may also contribute to pathogenesis. These include the production of cytokines such as interleukin-15 by intestinal epithelial cells and local antigen presenting cells as a pivotal event in the disease process. A subset of unconventional T cells called gamma/delta T cells are also persistently expanded in the coeliac disease (CD) small intestinal epithelium and recent analysis has shown that these cells contribute to pathogenic inflammation. Other unconventional T cell subsets may play a local immunoregulatory role and require further study. It has also been suggested that, in addition to activation of pathogenic T helper cells by gluten peptides, other peptides may directly interact with the intestinal mucosa, further contributing to the disease process. We also discuss how myofibroblasts, a major source of tissue transglutaminase and metalloproteases, may play a key role in intestinal tissue remodeling. Contribution of each of these factors to pathogenesis is discussed to enhance our view of this complex disorder and to contribute to a wider understanding of chronic immune-mediated disease.

Celiac Disease: Diagnosis.

Historically the diagnosis of celiac disease has relied upon clinical, serological, and histological evidence. In recent years the use of sensitive serological methods has meant an increase in the diagnosis of celiac disease. The heterogeneous nature of the disorder presents a challenge in the study and diagnosis of the disease with patients varying from subclinical or latent disease to patients with overt symptoms. Furthermore the related gluten-sensitive disease dermatitis herpetiformis, while distinct in some respects, shares clinical and serological features with celiac disease. Here we summarize current best practice for the diagnosis of celiac disease and briefly discuss newer approaches. The advent of next-generation assays for diagnosis and newer clinical protocols may result in more sensitive screening and ultimately the possible replacement of the intestinal biopsy as the gold standard for celiac disease diagnosis.

IgG anti-tTG responses in different autoimmune conditions differ in their epitope targets and subclass usage.

Antibodies of the IgA class directed against the enzyme tissue transglutaminase (tTG) are highly specific for coeliac disease (CD). IgG antibodies to tTG also occur in CD, and have also been reported in autoimmune diseases such as type 1 diabetes mellitus and Crohn's disease. In comparison to the IgA anti-tTG response, little is known of the IgG anti-tTG response in terms of epitope specificity and IgG subclass usage. The aim of this study was to investigate and compare epitopes recognised by CD and non-CD IgG anti-tTG antibodies, and determine the relative proportions of the IgG subclasses comprising this response. IgG anti-tTG positive individuals who did not have CD were identified by screening groups of patients with type I diabetes mellitus, Crohn's disease and granulomatosis with polyangiitis. Results from ELISA blocking experiments and mutant tTG antigens demonstrate that non-CD IgG anti-tTG bind different epitopic determinants to CD IgG anti-tTG. The IgG subclass usage of coeliac disease and type 1 diabetes was dominated by IgG1, whereas this IgG subclass was infrequently a component of the IgG anti-tTG response in diseases such as granulomatosis with polyangiitis and Crohn's disease. The differences in epitope specificity and subclass usage of IgG anti-tTG observed between CD and non-CD individuals may be due to the differing mechanisms underlying tTG autoimmunity.

Altered distribution and increased IL-17 production by mucosal-associated invariant T cells in adult and childhood obesity.

Mucosal-associated invariant T (MAIT) cells are innate MHC-unrestricted cells that regulate inflammatory responses through the rapid production of cytokines. In this article, we show that circulating MAIT cells are depleted in obese adults, and depletion is associated with diabetic status. Circulating MAIT cells more frequently produced IL-17 upon stimulation ex vivo, a cytokine implicated in insulin resistance. MAIT cells were enriched in adipose tissue (AT) compared with blood. AT MAIT cells, but not circulating MAIT cells, were capable of producing IL-10. In AT from obese subjects, MAIT cells were depleted, were less likely to produce IL-10, and more frequently produced IL-17. Finally, we show that IL-17(+) MAIT cells are also increased in childhood obesity, and altered MAIT cell frequencies in obese children are positively associated with insulin resistance. These data indicate that MAIT cells are enriched in human AT and display an IL-17(+) phenotype in both obese adults and children, correlating with levels of insulin resistance. The alterations in MAIT cells may be contributing to obesity-related sterile inflammation and insulin resistance.

Exact coherent structures and chaotic dynamics in a model of cardiac tissue.

Unstable nonchaotic solutions embedded in the chaotic attractor can provide significant new insight into chaotic dynamics of both low- and high-dimensional systems. In particular, in turbulent fluid flows, such unstable solutions are referred to as exact coherent structures (ECS) and play an important role in both initiating and sustaining turbulence. The nature of ECS and their role in organizing spatiotemporally chaotic dynamics, however, is reasonably well understood only for systems on relatively small spatial domains lacking continuous Euclidean symmetries. Construction of ECS on large domains and in the presence of continuous translational and/or rotational symmetries remains a challenge. This is especially true for models of excitable media which display spiral turbulence and for which the standard approach to computing ECS completely breaks down. This paper uses the Karma model of cardiac tissue to illustrate a potential approach that could allow computing a new class of ECS on large domains of arbitrary shape by decomposing them into a patchwork of solutions on smaller domains, or tiles, which retain Euclidean symmetries locally.

Characterisation of tissue transglutaminase-reactive T cells from patients with coeliac disease and healthy controls.

Previous studies have shown evidence for T lymphocytes specific for tissue transglutaminase (tTG) in the periphery of coeliac disease (CD) patients. These cells could play a role in disease pathogenesis and may be involved in providing help for the production of anti-tTG autoantibodies. The objective of this study was to further investigate the presence of tTG-specific T cells in patients with treated and untreated CD, and normal controls. Positive proliferative responses to three different commercial tTG antigens were detected in all groups tested, occurring more frequently and at higher levels in untreated CD patients. The addition of antibodies to HLA-DQ and HLA-DR caused a significant reduction in the proliferative response to tTG. T cell lines specific for tTG and composed predominantly of CD4-positive T cells were generated from responsive CD and control individuals, and were found to produce large amounts of interferon-γ, as well as interleukins 10, 17A, and 21.

Protein kinase C delta is a substrate of tissue transglutaminase and a novel autoantigen in coeliac disease.

Post-translational modification of proteins by deamidation or transamidation by tissue transglutaminase (tTG) has been suggested as a possible mechanism for the development of autoimmunity. Sequence analysis of protein kinase C delta (PKCδ) identified an amino acid motif that suggested the possibility that PKCδ was a glutamine substrate of tTG and MALDI-TOF analysis of synthesised peptides from PKCδ proved that this was the case. Polymerisation experiments using recombinant tTG and biotinylated hexapeptide substrate incorporation assays demonstrated that PKCδ is a substrate for tTG-mediated transamidation. Elevated levels of anti-PKCδ antibodies were detected in sera from patients with coeliac disease (p<0.0001) but not from patients with other autoimmune disorders. These data suggest that a subset of patients with coeliac disease produce autoantibodies against PKCδ and that this response may stem from a tTG-PKCδ substrate interaction.

CFD and PIV analysis of hemodynamics in a growing intracranial aneurysm.

Hemodynamics is thought to be a fundamental factor in the formation, progression, and rupture of cerebral aneurysms. Understanding these mechanisms is important to improve their rupture risk assessment and treatment. In this study, we analyze the blood flow field in a growing cerebral aneurysm using experimental particle image velocimetry (PIV) and computational fluid dynamics (CFD) techniques. Patient-specific models were constructed from longitudinal 3D computed tomography angiography images acquired at 1-y intervals. Physical silicone models were constructed from the computed tomography angiography images using rapid prototyping techniques, and pulsatile flow fields were measured with PIV. Corresponding CFD models were created and run under matching flow conditions. Both flow fields were aligned, interpolated, and compared qualitatively by inspection and quantitatively by defining similarity measures between the PIV and CFD vector fields. Results showed that both flow fields were in good agreement. Specifically, both techniques provided consistent representations of the main intra-aneurysmal flow structures and their change during the geometric evolution of the aneurysm. Despite differences observed mainly in the near wall region, and the inherent limitations of each technique, the information derived is consistent and can be used to study the role of hemodynamics in the natural history of intracranial aneurysms.

Binding of autoantibodies to the core region of tissue transglutaminase is a feature of paediatric coeliac disease.

OBJECTIVES: Production of autoantibodies to the enzyme tissue transglutaminase (tTG) is a hallmark of coeliac disease (CD). We have previously demonstrated that the immumoglobulin (Ig) A response to tTG in adult CD specifically targets its catalytic core region, containing the active-site triad of amino acids. The aim of the present study was to investigate this phenomenon in paediatric patients with CD, and to elucidate the contribution of each active-site residue to epitopes recognised. The specificity of the IgG anti-tTG response was also investigated and compared with that of the IgA anti-tTG response, in both paediatric and adult patients with CD. METHODS: Wild-type and novel variants of tTG were generated via site-directed mutagenesis and expressed as glutathione-S-transferase-fusion proteins in Escherichia coli BL-21. The mutagenic variants of tTG had substitutions of 1, 1, or all of the 3 of the catalytic triad amino acids. All of the recombinant tTGs were tested for their antigenicity in IgA and IgG enzyme-linked immunosorbent assays with cohorts of paediatric (n=63) and adult (n=30) CD sera. RESULTS: Substitution of even 1 amino acid in the catalytic triad resulted in a significant reduction of CD IgA and IgG anti-tTG binding, with all of the mutant proteins displaying diminished antigenicity compared with the wild-type protein. CONCLUSIONS: The core region of tTG is specifically targeted from early on in disease course by CD patient autoantibodies of both the IgA and IgG class.

Coeliac disease autoantibodies mediate significant inhibition of tissue transglutaminase.

The detection of antibodies directed against tissue transglutaminase (tTG) in serum is a sensitive and specific test for suspected coeliac disease. tTG is a ubiquitous, multifunctional enzyme that has been implicated in many important physiological processes as well as the site-specific deamidation of glutamine residues in gluten-derived peptides. This modification of gluten peptides facilitates their binding to HLA-DQ2, which results in amplification of the T-cell response to gluten. The purpose of this study was to investigate the possibility that patient IgA autoantibodies directed against tTG interfere with the crosslinking activity of the enzyme. IgA autoantibodies against tTG were isolated/depleted from patient serum and tested for their capacity to interfere with tTG activity in vitro using a sensitive fluorescence-based activity assay. We have demonstrated that autoantibodies cause significant inhibition of tTG-mediated crosslinking at equimolar and 2:1 ratios of antibody to enzyme.

Biological responses to hydroxyapatite surfaces deposited via a co-incident microblasting technique.

Hydroxyapatite (HA) is routinely used as a coating on a range of press-fit (cementless) orthopaedic implants to enhance their osseointegration. The standard plasma spraying method used to deposit a HA surface layer on such implants often contains unwanted crystal phases that can lead to coating delamination in vivo. Consequently, there has been a continuous drive to develop alternate surface modification technologies that can eliminate the problems caused by a non-optimal coating process. In this study two methods for creating a HA layer on metal alloys that employ micro-blasting have been evaluated to determine if the inclusion of an abrasive agent can enhance the in vitro and in vivo performance of the modified surface. The first method employs direct micro-blasting using HA as the abrasive media, while the second employs a simultaneous blasting with an alumina abrasive and coincident blasting with HA as a dopant. Whereas, both methods were found to produce a surface which was enriched with HA, the respective microstructures created were significantly different. Detailed surface characterisation revealed that the use of the abrasive produced disruption of the metal surface without producing detectable incorporation of alumina particles. Roughening of the metal surface in this way breached the passivating oxide layer and created sites which subsequently provided for impregnation, mechanical interlocking and chemical bonding of HA. The co-incident use of an alumina abrasive and a HA dopant resulted in a stable surface that demonstrated enhanced in vitro osteoblast attachment and viability as compared to the response to the surface produced using HA alone or the metal substrate control. Implantation of the surface produced by co-incident blasting with alumina and HA in a rabbit model confirmed that this surface promoted the in vivo formation of early stage lamellar bone growth.

Altered gene expression in highly purified enterocytes from patients with active coeliac disease.

BACKGROUND: Coeliac disease is a multifactorial inflammatory disorder of the intestine caused by ingestion of gluten in genetically susceptible individuals. Genes within the HLA-DQ locus are considered to contribute some 40% of the genetic influence on this disease. However, information on other disease causing genes is sparse. Since enterocytes are considered to play a central role in coeliac pathology, the aim of this study was to examine gene expression in a highly purified isolate of these cells taken from patients with active disease. Epithelial cells were isolated from duodenal biopsies taken from five coeliac patients with active disease and five non-coeliac control subjects. Contaminating T cells were removed by magnetic sorting. The gene expression profile of the cells was examined using microarray analysis. Validation of significantly altered genes was performed by real-time RT-PCR and immunohistochemistry. RESULTS: Enterocyte suspensions of high purity (98-99%) were isolated from intestinal biopsies. Of the 3,800 genes investigated, 102 genes were found to have significantly altered expression between coeliac disease patients and controls (p < 0.05). Analysis of these altered genes revealed a number of biological processes that are potentially modified in active coeliac disease. These processes include events likely to contribute to coeliac pathology, such as altered cell proliferation, differentiation, survival, structure and transport. CONCLUSION: This study provides a profile of the molecular changes that occur in the intestinal epithelium of coeliac patients with active disease. Novel candidate genes were revealed which highlight the contribution of the epithelial cell to the pathogenesis of coeliac disease.

Mutagenesis of the catalytic triad of tissue transglutaminase abrogates coeliac disease serum IgA autoantibody binding.

BACKGROUND AND AIMS: Tissue transglutaminase (tTG) is an autoantigen in coeliac disease and the related disorder, dermatitis herpetiformis. The detection of autoantibodies directed against tTG is a highly specific marker of coeliac disease; however, it is unclear if there is a role for these autoantibodies in the disease process. The aim of this study was to investigate whether the catalytic triad of tTG is targeted by coeliac disease autoantibodies. METHODS: A full-length wild-type recombinant tTG and a novel site-directed mutagenic variant lacking the catalytic triad were produced in Escherichia coli. Serum samples from 61 biopsy-proven coeliac disease and 10 dermatitis herpetiformis patients were tested for their recognition of both antigens in enzyme-linked immunosorbent assay. RESULTS: Although IgA autoantibodies from sera of patients with coeliac disease and dermatitis herpetiformis bound wild-type tTG well, a dramatic decrease in binding to the mutant tTG was observed with a mean reduction of 79% in coeliac disease and 58% in dermatitis herpetiformis samples. IgG anti-tTG antibodies did not show a similar pattern of reduction, with no overall difference in recognition of the wild-type or mutant tTGs. CONCLUSIONS: These results suggest that the IgA anti-tTG response in coeliac disease and dermatitis herpetiformis is focused on the region of tTG responsible for its transamidation and deamidation reactions, whereas the IgG response may target other regions of the enzyme.

Expression of an anti-botulinum toxin A neutralizing single-chain Fv recombinant antibody in transgenic tobacco.

Botulinum neurotoxins (BoNTs) are the most poisonous substances known and are thus classified as high-risk threats for use as bioterror agents. To examine the potential of transgenic plants as bioreactors for the production of BoNT antidotes, we transformed tobacco with an optimized, synthetic gene encoding a botulinum neurotoxin A (BoNT/A) neutralizing single-chain Fv (scFv) recombinant antibody fragment. In vitro mouse muscle twitch assays demonstrated the functional utility of this scFv extracted from tobacco for neutralizing the paralytic effects of BoNT/A at neuromuscular junctions. Based on the efficiency of the scFv capture process and the dose required to antidote a human being, 1-2 ha of this tobacco could yield up to 4 kg of scFv, which would be enough to contribute to the manufacture of 1,000,000 therapeutic doses of a monoclonal antibody (mAb) cocktail capable of neutralizing the effects of BoNT poisoning. Transgenic plants could provide an inexpensive production platform for expression of multiple mAbs toward the creation of polyclonal therapies (i.e. pooled mAbs) as the next improvement in recombinant antibody therapy.