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Tea is one of the most ancient and popular therapeutic beverages consumed by people all over the world. It is made from the leaves and buds of the plant “C. sinensis”. Tea is cultivated in more than thirty countries around the world as a plantation crop. In the present study, thirty tea samples of 20 black and 10 green tea manufactured in Sri Lanka were screened for antioxidant activities. Black tea samples were obtained from the three main geographical regions low (Dust (I), BOPF, BOPI, OPI, Pekoe), mid (Dust (I), Dust, BOPF Local, BOPI, BOP, OPI, Pekoe) and up (Dust, BOPF, BOP, FBOP, FBOPI, OPA, OPI, Pekoe) country of Sri Lanka. Green tea samples are manufactured by two different processing methods; panning (Ceylon GT Chunmee (I), Ceylon GT Chunmee (II), Ceylon GT Fanning’s, Ceylon GT Gun Powder (GP) (Extra Spl), Hyson, OPA green tea Ceylon GT Special Hyson) and steaming (Ceylon Sencha OPA, Ceylon Tencha, Cut Twist Curl (CTC) green tea) were used in the investigation. Total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities using ABTS, FRAP, DPPH and, ORAC assays were determined for each tea infusion. According to the results, phenolic content was higher in green tea than that of black tea and flavonoid content was lower in green tea than in black tea. Results of all antioxidants assays showed higher values for green tea than black tea. Neither the geographic area from which the samples of black tea came nor the method of preparation of green tea showed any significant differences in the activities. The results of the study have shown that Sri Lankan tea has compounds with antioxidant activities. Therefore, Sri Lankan tea can be used as a therapeutic beverage and a possibility to use the tea for producing antioxidant drugs through extraction and isolation processes.

PURPOSE OF REVIEW: The purpose of this article is to review medial ulnar collateral ligament (UCL) injuries in contact athletes. UCL injuries in overhead throwing athletes are typically chronic attenuation due to repetitive valgus stress on the elbow during the throwing motion. As such, UCL reconstruction is commonly performed for these athletes. In contrast, UCL injuries in contact athletes are usually acute ligament tears or avulsions of a ligament with otherwise normal tissue. Nonoperative treatment is typically the first-line treatment for partial injuries. UCL repair may work well for acute complete injuries and may avoid the donor site morbidity of UCL reconstruction. RECENT FINDINGS: Most of the literature regarding UCL injuries have been performed in baseball players. Historically, UCL repair has had poor outcomes in baseball players due to the chronic ligament attenuation. Therefore, much of the recent literature has focused on outcomes of UCL reconstruction, which are generally excellent. However, there is a paucity of literature studying outcomes of UCL injuries in contact athletes and those studying UCL repair. One recent study looked at a new technique for UCL repair with collagen-coated fiber tape augmentation in baseball players and found good short-term outcomes. SUMMARY: UCL injuries in contact athletes occur typically as acute tears or avulsions. While UCL reconstruction has typically been recommended as the accepted treatment for UCL tears that require operative treatment, UCL repair may be a good alternative in contact athletes.

In the search for mechanisms that contribute to dyslexia, the term “attention” has been invoked to explain performance in a variety of visual tasks, creating confusion since all tasks do, indeed, demand “attention”. Many studies lack an experimental manipulation of attention that would be necessary to determine its influence on task performance. Nonetheless, an emerging view is that children with dyslexia have an impairment in the exogenous (automatic/reflexive) orienting of spatial attention. Here we investigated the link between exogenous attention and reading ability by presenting exogenous spatial pre-cues in a task relevant for reading. A string of six letters was briefly presented and participants were asked to report the identity of a single post-cued letter. Just before the letters appeared, uninformative pre-cues flashed to the right or left, or on both sides of fixation. The task was gamified and administered online to children (N=187) between 6 and 17 years. For each participant we also obtained psychometric evaluations of their reading skills. Children with dyslexia (N=75) performed worse overall at rapidly recognizing and reporting a letter from a string. However, we found no evidence for a difference in the utilization of exogenous spatial cues, resolving two decades of ambiguity in the field. Previous studies that claimed a link between exogenous spatial attention and reading ability may have failed to isolate specific attention effects from overall task performance, or found group differences, in small samples, that are specific to certain artificial stimuli and experimental tasks.

Purpose Dental school curricula increasingly emphasize training in leadership, public health, community engagement and collaboration. Leadership may be defined as a relational process for inspiring and influencing positive change. Leadership training focused on effectively building relationships and partnerships to improve community health is particularly important with the increased emphasis on dental primary care, holistic care, rural care and health disparities. Dentists and other health care providers are encouraged to engage with communities and community partners and organizations to improve healthcare and overall health. To better educate and train dental students to meet these challenges, new and innovative methods of didactic and experiential coursework are needed. The paper aims to discuss these issues. Design/methodology/approach The current study describes the development, delivery and preliminary evaluation of a community-engaged leadership training program for dental students. The program incorporated student-developed public health project proposals and sessions with simulated community partners based on a simulated rural community with specific oral and general health needs. Findings Overall, students felt the training was realistic and valuable for developing leadership skills and preparing them for challenges that could not have been learned through didactic instruction alone. Students gained a better understanding of their own leadership styles, their strengths and weaknesses and their level of developed leadership competencies. Originality/value This program is an innovative way to develop leadership applied to public health and community needs and should have implications for ways of teaching leadership to improve oral health outcomes.

PURPOSE: In response to COVID-19, dental educators have been tasked with maintaining the quality of education while reducing cost, increasing efficiency, and leveraging technology. METHODS: This collaborative, multisite virtual health policy course used the Staged Self-Directed Learning Model (SSDL) to lead a diverse group of students studying health policy. Twelve Core sessions were offered with three additional sessions in August or December for a total of 15 total synchronous Zoom sessions that covered policy issues on supply, demand, and need for dental care. RESULTS: Twenty-eight students, seven lead instructors, and two course directors from six schools reported positive feedback on the course format, use of technology and the SSDL model, and breadth of topics presented. Participation by universities in four states with differing health policies stimulated virtual classroom discussions. CONCLUSION: In conclusion, collaborative interinstitutional virtual teaching and learning is cost effective, efficient, and engaging for students. This model has the potential to continue even when institutions are no longer affected by COVID-19.

Limb position changes are likely during transport from injury location to definitive care. This study investigated passive limb position change effects on tourniquet pressure and occlusion.Triplicate buddy-applied OMNA® Marine Tourniquet applications to Doppler-based occlusion were done to sitting and laying supine mid-thigh (n=5) and sitting mid-arm (n=3). Tourniqueted limb positions were bent/straight/bent and straight/bent/straight (randomized first position order, 5 seconds/position, pressure every 0.1 second, two-way repeated measures ANOVA).Sitting thigh occlusion pressures leg bent were higher than straight (median, minimum-maximum; 328, 307-403mmHg versus 312, 295-387mmHg, p = .013). In each recipient, the pressure change for each position change for each limb had p.003. In each recipient, when sitting, leg bent to straight increased pressure (326, 276-415mmHg to 371, 308-427mmHg bent first and 275, 233-354mmHg to 311, 241-353mmHg straight first), and straight to bent decreased pressure (371, 308-427mmHg to 301, 262-388mmHg bent first and 312, 265-395mmHg to 275, 233-354mmHg straight first). When laying, position changes from leg bent first resulted in pressure changes in each recipient but not in the same directions in each recipient. From laying leg straight first, in each recipient changing to bent increased the pressure (295, 210-366mmHg to 328, 255-376mmHg) and to straight decreased the pressure (328, 255-376 mmHg to 259, 210-333 mmHg). Sitting arm bent occlusion pressures were lower than straight (230, 228-252mmHg versus 256, 250-287mmHg, p = .026). Arm position changes resulted in pressure changes in each recipient but not in the same directions in each recipient. Changes in pressure trace character (presence or absence of rhythmically pulsatile traces) and Doppler-based occlusion were consistent with limb position-induced changes in tourniquet pressure (each p ≤ .001 leg, p = .071 arm traces, and p = .188 arm occlusion).Passive limb position changes can cause significant changes in tourniquet pressure. Therefore, tourniquet adequacy should be reassessed after any limb position change.

Surface temperature is necessary for the estimation of energy fluxes and evapotranspiration from satellites and airborne data sources. For example, the Two-Source Energy Balance (TSEB) model uses thermal information to quantify canopy and soil temperatures as well as their respective energy balance components. While surface (also called kinematic) temperature is desirable for energy balance analysis, obtaining this temperature is not straightforward due to a lack of spatially estimated narrowband (sensor-specific) and broadband emissivities of vegetation and soil, further complicated by spectral characteristics of the UAV thermal camera. This study presents an effort to spatially model narrowband and broadband emissivities for a microbolometer thermal camera at UAV information resolution (~0.15 m) based on Landsat and NASA HyTES information using a deep learning (DL) model. The DL model is calibrated using equivalent optical Landsat / UAV spectral information to spatially estimate narrowband emissivity values of vegetation and soil in the 7–14- nm range at UAV resolution. The resulting DL narrowband emissivity values were then used to estimate broadband emissivity based on a developed narrowband-broadband emissivity relationship using the MODIS UCSB Emissivity Library database. The narrowband and broadband emissivities were incorporated into the TSEB model to determine their impact on the estimation of instantaneous energy balance components against ground measurements. The proposed effort was applied to information collected by the Utah State University AggieAir small Unmanned Aerial Systems (sUAS) Program as part of the ARS-USDA GRAPEX Project (Grape Remote sensing Atmospheric Profile and Evapotranspiration eXperiment) over a vineyard located in Lodi, California. A comparison of resulting energy balance component estimates, with and without the inclusion of high-resolution narrowband and broadband emissivities, against eddy covariance (EC) measurements under different scenarios are presented and discussed.

The thermal-based Two-Source Energy Balance (TSEB) model partitions the evapotranspiration (ET) and energy fluxes from vegetation and soil components providing the capability for estimating soil evaporation (E) and canopy transpiration (T). However, it is crucial for ET partitioning to retrieve reliable estimates of canopy and soil temperatures and net radiation, as the latter determines the available energy for water and heat exchange from soil and canopy sources. These two factors become especially relevant in row crops with wide spacing and strongly clumped vegetation such as vineyards and orchards. To better understand these effects, very high spatial resolution remote-sensing data from an unmanned aerial vehicle were collected over vineyards in California, as part of the Grape Remote sensing and Atmospheric Profile and Evapotranspiration eXperiment and used in four different TSEB approaches to estimate the component soil and canopy temperatures, and ET partitioning between soil and canopy. Two approaches rely on the use of composite $$T_\mathrm{rad}$$ , and assume initially that the canopy transpires at the Priestley–Taylor potential rate. The other two algorithms are based on the contextual relationship between optical and thermal imagery partition $$T_\mathrm{rad}$$ into soil and canopy component temperatures, which are then used to drive the TSEB without requiring a priori assumptions regarding initial canopy transpiration rate. The results showed that a simple contextual algorithm based on the inverse relationship of a vegetation index and $$T_\mathrm{rad}$$ to derive soil and canopy temperatures yielded the closest agreement with flux tower measurements. The utility in very high-resolution remote-sensing data for estimating ET and E and T partitioning at the canopy level is also discussed.

Evapotranspiration (ET) derived from remote sensing-based models represents ½ hourly to hourly value that is upscaled to a daily scale for practical applications in the fields of agricultural and water management. Several upscaling methods such as Gaussian fitting curve, sine approach, and evaporative fraction approach have been developed to extrapolate remote sensing-based ET values to daily scale by assuming constant daytime ratios (e.g., self-preservation of available energy partitioning). This simple assumption can result in uncertainties in the performance of those methods and can be violated for unstable conditions such as a cloudy day. Studies showed that, for example, diurnal variation of incoming shortwave radiation will change from a Gaussian distribution to a multimodal distribution on a cloudy day. Besides, when remote-sensing ET outputs are directly upscaled to daily scale and compared with eddy covariance measurements, a fixed footprint of eddy covariance is assumed, while the actual eddy covariance footprint is dynamic and changes with wind speed, direction and atmospheric stability. In this study, a new method is proposed to spatially and temporally simulate canopy and soil temperature for each time step (e.g., 1-hour) based on the temperature pattern recorded by IRT temperature sensors and UAV initial temperatures at the specific time of day. Next, the Two-Source Energy Balance (TSEB) model is executed for each time step of the daytime period (usually when net radiation >100 W/m^2) to calculate energy balance components. The integration of TSEB outputs over the daytime period leads to estimations of daily energy balance components. Since cloudy conditions affect temperatures recorded by IRT sensors, the proposed model is not sensitive to weather conditions. In addition, the proposed model physically simulates ET at each time step instead of directly extrapolating ET from a single remote sensing observation and model output This feature solves the limitations of comparing the direct extrapolation methods of instantaneous ET against eddy covariance measurements. The proposed approach is applied on information collected by the Utah State University AggieAir small Unmanned Aerial Systems (sUAS) Program as part of the ARS-USDA GRAPEX Project (Grape Remote sensing Atmospheric Profile and Evapotranspiration eXperiment) conducted since 2014 over multiple vineyards located in California. The estimated ET values from the TSEB model at hourly time steps and integrated over the daytime period are compared to eddy covariance measurements of ET. Additionally, hourly model output integrated over the daytime period compared to the different upscaling methods are presented and discussed.

Cellular esterases catalyze many essential biological functions by performing hydrolysis reactions on diverse substrates. The promiscuity of esterases complicates assignment of their substrate preferences and biological functions. To identify universal factors controlling esterase substrate recognition, we designed a 32-member structure–activity relationship (SAR) library of fluorogenic ester substrates and used this library to systematically interrogate esterase preference for chain length, branching patterns, and polarity to differentiate common classes of esterase substrates. Two structurally homologous bacterial esterases were screened against this library, refining their previously broad overlapping substrate specificity. Vibrio cholerae esterase ybfF displayed a preference for γ-position thioethers and ethers, whereas Rv0045c from Mycobacterium tuberculosis displayed a preference for branched substrates with and without thioethers. We determined that this substrate differentiation was partially controlled by individual substrate selectivity residues Tyr-119 in ybfF and His-187 in Rv0045c; reciprocal substitution of these residues shifted each esterase's substrate preference. This work demonstrates that the selectivity of esterases is tuned based on transition state stabilization, identifies thioethers as an underutilized functional group for esterase substrates, and provides a rapid method for differentiating structural isozymes. This SAR library could have multifaceted future applications, including in vivo imaging, biocatalyst screening, molecular fingerprinting, and inhibitor design.

In recent years, the deployment of satellites and unmanned aerial vehicles (UAVs) has led to production of enormous amounts of data and to novel data processing and analysis techniques for monitoring crop conditions. One overlooked data source amid these efforts, however, is incorporation of 3D information derived from multi-spectral imagery and photogrammetry algorithms into crop monitoring algorithms. Few studies and algorithms have taken advantage of 3D UAV information in monitoring and assessment of plant conditions. In this study, different aspects of UAV point cloud information for enhancing remote sensing evapotranspiration (ET) models, particularly the Two-Source Energy Balance Model (TSEB), over a commercial vineyard located in California are presented. Toward this end, an innovative algorithm called Vegetation Structural-Spectral Information eXtraction Algorithm (VSSIXA) has been developed. This algorithm is able to accurately estimate height, volume, surface area, and projected surface area of the plant canopy solely based on point cloud information. In addition to biomass information, it can add multi-spectral UAV information to point clouds and provide spectral-structural canopy properties. The biomass information is used to assess its relationship with in situ Leaf Area Index (LAI), which is a crucial input for ET models. In addition, instead of using nominal field values of plant parameters, spatial information of fractional cover, canopy height, and canopy width are input to the TSEB model. Therefore, the two main objectives for incorporating point cloud information into remote sensing ET models for this study are to (1) evaluate the possible improvement in the estimation of LAI and biomass parameters from point cloud information in order to create robust LAI maps at the model resolution and (2) assess the sensitivity of the TSEB model to using average/nominal values versus spatially-distributed canopy fractional cover, height, and width information derived from point cloud data. The proposed algorithm is tested on imagery from the Utah State University AggieAir sUAS Program as part of the ARS-USDA GRAPEX Project (Grape Remote sensing Atmospheric Profile and Evapotranspiration eXperiment) collected since 2014 over multiple vineyards located in California. The results indicate a robust relationship between in situ LAI measurements and estimated biomass parameters from the point cloud data, and improvement in the agreement between TSEB model output of ET with tower measurements when employing LAI and spatially-distributed canopy structure parameters derived from the point cloud data.

OBJECTIVES Accountable care organizations (ACOs) are a new model of health-care delivery that aim to improve care through increased provider collaboration and financial rewards for meeting cost and quality targets for a defined patient population. In this study, we examined a state policy change that effectively moved some children with disabilities into a Medicaid-serving pediatric ACO on dental service use. We hypothesize that ACOs' emphasis on prevention, care coordination, and reduction in emergency department use will extend to dental services. STUDY DESIGN/METHODS We used Ohio Medicaid administrative claims data for year 2011-2016 to examine changes in patterns of dental service use by Medicaid-eligible children with disabilities before and after enrolling in an ACO compared with similar children enrolled in non-ACO managed care plans. RESULTS Dental utilization is relatively low among Medicaid-eligible children with disabilities. We find that preventive dental visits increased 3.1% points (P

Human immunodeficiency virus infection is the most common risk factor for severe forms of tuberculosis (TB) regardless of CD4 T cell count. Using a well-characterized cynomolgus macaque model, we compared reactivation of latent M. tuberculosis (Mtb) infection induced by simian immunodeficiency virus (SIV) or anti-CD4 antibody (αCD4). Reactivation, as defined by the appearance of a new lung lesion by PET CT, occurred in 5 of 7 αCD4 treated animals compared to 4 of 8 SIV infected animals within 2 months of treatment. αCD4 animals had significantly fewer CD4 T cells within granulomas compared to SIV/Mtb infected animals. However, compared to αCD4 groups, SIV infection caused more dissemination of lung granulomas and higher granuloma bacterial burdens. Within the granulomas, SIV replication was associated with greater Mtb growth and reduced Mtb killing. Granulomas from SIV/Mtb animals displayed a distinctly different profile of T cell cytokine and granzyme B expression compared to αCD4 animals and controls. PET CT imaging prior to treatment could predict reactivation in αCD4-treated animals, but not in SIV/Mtb animals. These data suggest that SIV infection disrupts protective immune responses against Mtb infection beyond the loss of CD4 T cells, and that synergy between SIV and Mtb occurs within granulomas.

Biological networks are a very convenient modeling and visualization tool to discover knowledge from modern high-throughput genomics and post-genomics data sets. Indeed, biological entities are not isolated but are components of complex multilevel systems. We go one step further and advocate for the consideration of causal representations of the interactions in living systems. We present the causal formalism and bring it out in the context of biological networks, when the data is observational. We also discuss its ability to decipher the causal information flow as observed in gene expression. We also illustrate our exploration by experiments on small simulated networks as well as on a real biological data set.

Biological networks are a very convenient modeling and visualization tool to discover knowledge from modern high-throughput genomics and post-genomics data sets. Indeed, biological entities are not isolated but are components of complex multilevel systems. We go one step further and advocate for the consideration of causal representations of the interactions in living systems. We present the causal formalism and bring it out in the context of biological networks, when the data is observational. We also discuss its ability to decipher the causal information flow as observed in gene expression. We also illustrate our exploration by experiments on small simulated networks as well as on a real biological data set.

Objectives The specific aims of this study were to describe the baseline oral health status of persons residing in North Carolina assisted living facilities and determine how identified oral health problems vary according to resident and facility demographic variables. Methods This cross-sectional descriptive epidemiologic study used a statewide random sample of 40 assisted living facilities and a convenience sample of 854 assisted living residents. Dental hygienists and dentists conducted oral screenings on residents using the Association of State and Territorial Dental Director's Basic Screening Survey for Older Adults tool. Results Nearly one-third of participants were younger than 65. Overall, poorer oral health was noted for non-Hispanic black residents, Medicaid recipients, residents of small facilities (20-60 beds), and residents of facilities located in the Coastal Plains region of the state. Oral health also worsened with increasing length of residence yet seemed to improve with age. The overall rate of edentulism was 29 percent, half of whom did not have complete dentures. Nearly half (48.6 percent) of residents had untreated decay. Conclusions There is a need for policy and public health programming that addresses the broad racial and socioeconomic factors that contribute to disparities among the institutionalized. Furthermore, the oral health disparities between institutionalized and community-dwelling older adults reflect the need for policy that requires and ensures access to a minimum level of oral health care throughout the duration of a resident's stay. Programming to support such policy should include development of an oral health workforce that is competent in geriatric oral health care.

Among the proteins required for lipid metabolism in Mycobacterium tuberculosis are a significant number of uncharacterized serine hydrolases, especially lipases and esterases. Using a streamlined synthetic method, a library of immolative fluorogenic ester substrates was expanded to better represent the natural lipidomic diversity of Mycobacterium. This expanded fluorogenic library was then used to rapidly characterize the global structure activity relationship (SAR) of mycobacterial serine hydrolases in M. smegmatis under different growth conditions. Confirmation of fluorogenic substrate activation by mycobacterial serine hydrolases was performed using nonspecific serine hydrolase inhibitors and reinforced the biological significance of the SAR. The hydrolases responsible for the global SAR were then assigned using gel-resolved activity measurements, and these assignments were used to rapidly identify the relative substrate specificity of previously uncharacterized mycobacterial hydrolases. These measurements provide a global SAR of mycobacterial hydrolase activity, a picture of cycling hydrolase activity, and a detailed substrate specificity profile for previously uncharacterized hydrolases.

Current methods of traffic impact analysis, which rely on rates and adjustments from ITE, are believed to understate the traffic benefits of mixed-use developments (MXDs) and therefore to lead to higher exactions and development fees than necessary and to discourage otherwise desirable developments. The purpose of this study was to improve methodology for predicting the traffic impacts of MXDs. Standard protocols were used to identify and generate data sets for MXDs in 13 large and diverse metropolitan regions. Data from household travel surveys and geographic information system databases were pooled for these MXDs, and travel and built-environment variables were consistently defined across regions. Hierarchical modeling was used to estimate models for internal capture of trips within MXDs and for walking, biking, and transit use on external trips. MXDs with diverse activities on site were shown to capture a large share of trips internally, so that the traffic impacts of the MXDs were reduced relative to conventional suburban developments. Smaller MXDs in walkable areas with good transit access generated significant shares of walk, bike, and transit trips and thus also mitigated traffic impacts.

Protein expression and localization are often studied in vivo by tagging molecules with green fluorescent protein (GFP), yet subtle changes in protein levels are not easily detected. To develop a sensitive in vivo method to amplify fluorescence signals and allow cell-specific quantification of protein abundance changes, we sought to apply an enzyme-activated cellular fluorescence system in vivo by delivering ester-masked fluorophores to Caenorhabditis elegans neurons expressing porcine liver esterase (PLE). To aid uptake into sensory neuron membranes, we synthesized two novel fluorogenic hydrolase substrates with long hydrocarbon tails. Recombinant PLE activated these fluorophores in vitro. In vivo activation occurred in sensory neurons, along with potent activation in intestinal lysosomes quantifiable by imaging and microplate and partially attributable to gut esterase 1 (GES-1) activity. These data demonstrate the promise of biorthogonal hydrolases and their fluorogenic substrates as in vivo neuronal imaging tools and for characterizing endogenous C. elegans hydrolase substrate specificities.

Synthesis and HIV-1 protease inhibitory activity of compound 5 based on the structure of a novel cyclic sulfonamide pharmacophore has been recently disclosed from our group. X-ray crystallographic structure of 5 when bound to the HIV-1 protease defined its binding mode. The importance of the geometry of the substitution at C4–Me (S configuration) was emphasized. In the present paper we wish to disclose the design of novel inhibitors 47 and 48 based on the X-ray structure of compound 5 bound to the HIV-1 protease, their synthesis and activity against HIV-1 protease. By making changes at the C4 position and the carbamate linkage the above compounds 47 and 48 were found to be approximately one hundred fold more active compared to 5 and their Ki values are in the picomolar range. An unusual observation regarding the activity and geometry was made with compounds 51 and 52. X-ray results demonstrate that 48 and 52 bind to the same binding pocket with simultaneous change in the conformation of the cyclic sulfonamide ring.

Objective— Although atherosclerosis is associated with systemic risk factors such as age, high cholesterol, and obesity, plaque formation occurs predominately at branches and bends that are exposed to disturbed patterns of blood flow. The molecular mechanisms that link disturbed flow–generated mechanical forces with arterial injury are uncertain. To illuminate them, we investigated the effects of flow on endothelial cell (EC) senescence. Approach and Results— LDLR −/− (low-density lipoprotein receptor −/− ) mice were exposed to a high-fat diet for 2 to 12 weeks (or to a normal chow diet as a control) before the assessment of cellular senescence in aortic ECs. En face staining revealed that senescence-associated β-galactosidase activity and p53 expression were elevated in ECs at sites of disturbed flow in response to a high-fat diet. By contrast, ECs exposed to undisturbed flow did not express senescence-associated β-galactosidase or p53. Studies of aortae from healthy pigs (aged 6 months) also revealed enhanced senescence-associated β-galactosidase staining at sites of disturbed flow. These data suggest that senescent ECs accumulate at disturbed flow sites during atherogenesis. We used in vitro flow systems to examine whether a causal relationship exists between flow and EC senescence. Exposure of cultured ECs to flow (using either an orbital shaker or a syringe-pump flow bioreactor) revealed that disturbed flow promoted EC senescence compared with static conditions, whereas undisturbed flow reduced senescence. Gene silencing studies demonstrated that disturbed flow induced EC senescence via a p53-p21 signaling pathway. Disturbed flow–induced senescent ECs exhibited reduced migration compared with nonsenescent ECs in a scratch wound closure assay, and thus may be defective for arterial repair. However, pharmacological activation of sirtuin 1 (using resveratrol or SRT1720) protected ECs from disturbed flow–induced senescence. Conclusions— Disturbed flow promotes endothelial senescence via a p53-p21–dependent pathway which can be inhibited by activation of sirtuin 1. These observations support the principle that pharmacological activation of sirtuin 1 may promote cardiovascular health by suppressing EC senescence at atheroprone sites.