Periods Of Low Risk Research Articles

Detection of seizure clustering using ultralong-term subcutaneous EEG monitoring

AbstractEpileptic seizures usually occur unpredictably yet not necessarily at random times. Cyclical patterns of seizure recurrence have been broadly described. Long-term seizure documentation may reveal individual cyclical seizure patterns; however, seizure reporting by patients or their caregivers is often inaccurate. Modern technologies for at-home monitoring of epileptic seizures enable continuous EEG recording for objective seizure counts over long-term timescales. Here, we present the clinical case of a patient with temporal lobe epilepsy due to hippocampal sclerosis who underwent ultralong-term subcutaneous EEG recording over a 1-year period, which revealed the occurrence of seizure clusters at three- to four-weekly intervals. The case demonstrates the possibility of detection of subject-specific seizure timing using a minimally invasive subcutaneous EEG recorder for ultralong-term at-home seizure monitoring. Information about individual seizure timing may contribute to a more personalized chronotherapeutic treatment approach in which antiseizure medication can be maintained at low doses during the low-risk periods and increased briefly before the anticipated seizures.

A novel passive-active detection system for false data injection attacks in industrial control systems

With the increasing occurrence of incidents causing significant damage due to attacks on Industrial Control Systems (ICSs), people pay attention to the cyber security of ICSs. This study improves existing active detection mechanisms and proposes an integrated passive-active detection system to detect False Data Injection Attacks (FDIA) for ICS. Since it is challenging to detect FDIA in current operational practices, the method presented in this research not only compares passive received system data with predefined rules to detect attacks but also launches active detection by controlling actuators to find attackers and achieve comprehensive detection of FDIA targeting ICS. This work dynamically adjusts the frequency of launching active detection through risk assessment, aiming to minimize the impact on operational efficiency during low-risk periods and reduce the time required for detecting attacks during high-risk periods. The experimental results show that using the proposed system, when false data differs by 10 % from accurate data, the detection rate can reach 99.9 %, which is 22.5 % higher than active detection by the random launch method when false data differs by 5 % from accurate data, the detection rate can reach 95.4 %, which is 18.2 % higher than active detect by randomly launch method, and even if false data only differs by 3 % from accurate data, the detection rate can reach 92.9 %, which is 16.5 % higher than active detect by randomly launch method.

Development of a novel dynamic nosocomial infection risk management method for COVID-19 in outpatient settings

BackgroundApplication of accumulated experience and management measures in the prevention and control of coronavirus disease 2019 (COVID-19) has generally depended on the subjective judgment of epidemic intensity, with the quality of prevention and control management being uneven. The present study was designed to develop a novel risk management system for COVID-19 infection in outpatients, with the ability to provide accurate and hierarchical control based on estimated risk of infection.MethodsInfection risk was estimated using an auto regressive integrated moving average model (ARIMA). Weekly surveillance data on influenza-like-illness (ILI) among outpatients at Xuanwu Hospital Capital Medical University and Baidu search data downloaded from the Baidu Index in 2021 and 22 were used to fit the ARIMA model. The ability of this model to estimate infection risk was evaluated by determining the mean absolute percentage error (MAPE), with a Delphi process used to build consensus on hierarchical infection control measures. COVID-19 control measures were selected by reviewing published regulations, papers and guidelines. Recommendations for surface sterilization and personal protection were determined for low and high risk periods, with these recommendations implemented based on predicted results.ResultsThe ARIMA model produced exact estimates for both the ILI and search engine data. The MAPEs of 20-week rolling forecasts for these datasets were 13.65% and 8.04%, respectively. Based on these two risk levels, the hierarchical infection prevention methods provided guidelines for personal protection and disinfection. Criteria were also established for upgrading or downgrading infection prevention strategies based on ARIMA results.ConclusionThese innovative methods, along with the ARIMA model, showed efficient infection protection for healthcare workers in close contact with COVID-19 infected patients, saving nearly 41% of the cost of maintaining high-level infection prevention measures and enhancing control of respiratory infections.

Closed-loop stimulation in periods with less epileptiform activity drives improved epilepsy outcomes.

In patients with drug-resistant epilepsy, electrical stimulation of the brain in response to epileptiform activity can make seizures less frequent and debilitating. This therapy, known as closed-loop responsive neurostimulation (RNS), aims to directly halt seizure activity via targeted stimulation of a burgeoning seizure. Rather than immediately stopping seizures as they start, many RNS implants produce slower, long-lasting changes in brain dynamics that better predict clinical outcomes. Here we hypothesize that stimulation during brain states with less epileptiform activity drives long-term changes that restore healthy brain networks. To test this, we quantified stimulation episodes during low- and high-risk brain states-that is, stimulation during periods with a lower or higher risk of generating epileptiform activity-in a cohort of 40 patients treated with RNS. More frequent stimulation in tonic low-risk states and out of rhythmic high-risk states predicted seizure reduction. Additionally, stimulation events were more likely to be phase-locked to prolonged episodes of abnormal activity for intermediate and poor responders when compared to super-responders, consistent with the hypothesis that improved outcomes are driven by stimulation during low-risk states. These results support the hypothesis that stimulation during low-risk periods might underlie the mechanisms of RNS, suggesting a relationship between temporal patterns of neuromodulation and plasticity that facilitates long-term seizure reduction.

Perceptions of COVID-19 related risks by platform-based couriers: An analysis of user comment threads on Reddit.

The COVID-19 pandemic increased demand for app-based platform-based couriers, creating job opportunities for individuals who have lost income because of COVID-19. Through various stages of lockdown, courier workers (e.g., delivering for Uber Eats, Amazon Flex, and Lyft) provide an essential service. At the same time, this form of work poses risks for exposure to the SARS-CoV-2 virus as these workers are highly mobile and in contact with many individuals. To explore how platform-based couriers discuss risks associated with their work during periods of high (first wave, second wave, third wave/rise in concerns regarding variants) and low risk during the COVID-19 pandemic, 2020-2021. We provide a narrative analysis of user posts (n = 2,866) on Reddit during periods of interest. Our analysis resulted in three central findings. First, we identified changing patterns in discourse as the pandemic went on. Second, we found that the theme of risk prevailed largely in the first wave, with dialogue dominated by tips and asking for advice about how to manage risk. Third, our findings reveal a growing polarization among users during the latter phases of the study. Polarization largely focused on acceptance (or not) of public health measures and the nature of their work as independent contractors and the role/responsibility of courier companies to offer protection. Our study is the first to document risks, from the perspectives of anonymous couriers who may be unwilling to share their honest opinions and thoughts through primary data collection where anonymity is not guaranteed.

Legacy gambling harms: What are they and how long do they last?

Legacy gambling harms are negative consequences of gambling that extend past periods of low risk, moderate risk and problem gambling. Gambling harm is typically measured within a 12-month timeframe and is often restricted to examining harm amongst active gamblers. The present research aimed to explore whether people experienced gambling harms 12 months or more after the resolution of at-risk or problem gambling, and how long these legacy harms lasted. An online survey was conducted in New Zealand with past and current gamblers and concerned significant others (CSOs) of gamblers, N = 1,240 (50.8% female), that asked them about both past and current gambling harms. A majority of both gamblers and CSOs of gamblers indicated that they still suffered from gambling harm even after most of their behavioural issues with gambling had been resolved, 12+ months ago. Legacy gambling harms reduced over time, with harms diminishing most quickly in the early years, and having an average half-life of 4 years. Harms involving community-relationships, church involvement, and domestic and other violence resolved more quickly than others. Legacy harms are common among ex-problem gamblers and should be considered in any full accounting of the impacts of gambling. Understanding the time course and persistence of legacy harms from gambling can provide gamblers, treatment professionals and public health experts with insights into how to address gambling's long-term consequences.

Recognizing the variation of bioavailable organic phosphorus in sediment and its significance between high and low risk periods for algal blooms in Lake Erhai

The sediment-bound organic phosphorus (Po) is increasingly recognized as a critical internal source for the lake eutrophication process due to its potential bioavailability for organisms. However, limited recognition about the bioavailability variations of sediment Po impeded the in-depth understanding upon the biogeochemical process of Po, especially the differences between high and low risk-periods of algal blooms (HRP-ABs and LRP-ABs). Primarily, significant difference between HRP-ABs (July–December) and LRP-ABs (January–June) was discerned by Mann-Kendall tests of TP, Chla and algal biomass. Biochemical and molecular characterizations, e.g., enzymatic hydrolysis with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), were combined to discern the bioavailability variation of sequential extracted sediment Po in HRP-ABs and LRP-ABs. The contents of enzymatically hydrolysable Po decreased in the following order: NaOH-Po > NaHCO3-Po > H2O-Po. The concentrations of bioavailable Po, including labile phosphate monoester (Labile Mono-P) and phosphodiester (Diester-P) were 21.8–58.4 mg/kg (averagely 44.3 mg/kg) and 19.5–35.8 mg/kg (averagely 28.2 mg/kg) in HRP-ABs and LRP-ABs, respectively. Notably, the amounts of bioavailable H2O-Po and NaHCO3-Po in HRP-ABs (13.4–33.3 mg/kg) were nearly 2–3 times of that in LRP-ABs (3.9–14 mg/kg), while no significant NaOH-Po differences were observed. Similarly, contrasting the HRP-ABs with LRP-ABs, more P-containing formulas were assigned in H2O-Po (2526 vs 1884) and NaHCO3-Po (1554 vs 863), with similar abundance in NaOH-Po. Furthermore, the molecular composition of bioavailable Po (Bio-Po, H/C > 1.2 O/C > 0.5), especially Bio-Po containing two P atoms (Bio-2Po) displayed significant variation in H2O-Po (308 vs 391, 217 vs 316) and NaHCO3-Po (114 vs 208, 40 vs 145) between HRP-ABs and LRP-ABs. This was largely attributed to its high bioavailability in Bio-2Po (>50% lipids, proteins and carbohydrates-like). Our findings upon the internally activated accumulation and transformation process interpretation of sediment bioavailable Po are of great significance for lake eutrophication control.

Automatic generative design and optimization of hospital building layouts in consideration of public health emergency

PurposeThis study aimed to propose a performance-oriented approach of automatically generative design and optimization of hospital building layouts in consideration of public health emergency, which intended to conduct reasonable layout design of hospital building to meet different performance requirements for both high efficiency during normal periods and low risk in the pandemic.Design/methodology/approachThe research design follows a sequential mixed methodology. First, key points and parameters of hospital building layout design (HBLD) are analyzed. Then, to meet the requirements of high efficiency and low risk, adjacent preference score and infection risk coefficient are constructed as constraints. On this basis, automatic generative design is conducted to generate building layout schemes. Finally, multi-objective deviation analysis is carried out to obtain the optimal scheme of hospital building layouts.FindingsAutomatic generative design of building layouts that integrates adjacent preferences and infection risks enables hospitals to achieve rapid transitions between normal (high efficiency) and pandemic (low risk) periods, which can effectively respond to public health emergencies. The proposed approach has been verified in an actual project, which can help systematically explore the solution for better decision-making.Research limitations/implicationsThe form of building layouts is limited to rectangles, and future work can explore conducting irregular layouts into optimization for the framework of generative design.Originality/valueThe contribution of this paper is the developed approach that can quickly and effectively generate more hospital layout alternatives satisfying high operational efficiency and low infection risk by formulating space design rules, which is of great significance in response to public health emergency.

Statistical methods for decision support systems in finance: how Benford’s law predicts financial risk

AbstractThis paper merges the statistical analysis of data regularities and decision support systems for investors. Specifically, it discusses the Benford’s law as a decision support device for financial investments. In particular, we illustrate the role of such a property of financial data as risk predictor for financial markets. First of all, we show empirical evidence of accordance between data on market index daily returns and Benford’s law. Then, we highlight that on short time period (1 year) the deviations from Benford’s law are related to low risk and positive trend periods; thepvalue of the$$\chi ^2$$χ2test against the Benford’s distribution displays some predicting power for the market average return and risk level.

One-Year Recording of Cardiac Arrhythmias in a Non-Infected Population with Cardiac Implantable Devices During the COVID-19 Pandemic.

ObjectiveCoronavirus disease 2019 (COVID-19) was associated with a higher risk of arrhythmia in infected patients. However, there are no reports about the effect of the ongoing pandemic on arrhythmias in the non-infected population. We measured the arrhythmia burden in a non-infected population with cardiac implantable devices.MethodsThe arrhythmia burden during the COVID-19 pandemic was compared to a 6-month interval in the pre-COVID-19 period. The COVID-19 pandemic was divided into high-risk (17 January 2020 to 16 March 2020) and low-risk periods (17 March 2020 to 17 July 2020) according to whether there were locally infected patients. Arrhythmia burdens were compared among the pre-COVID-19, high-risk, and low-risk periods.ResultsA total of 219 patients with 1859 episodes were included. We observed a larger proportion of patients with atrial fibrillation (AF) during the COVID-19 pandemic (38.36% vs 26.03%, p = 0.006). There was not significantly more ventricular arrhythmia during the COVID period than the pre-COVID-19 period (p > 0.05). During the high-risk period, daily frequency of non-sustained ventricular tachycardia (NSVT) (0.0172, 0.0475 vs 0.0109, 0.0164, p < 0.05), atrial tachycardia (AT) (0.0345, 0.0518 vs 0.0164, 0.0219 p < 0.05) and AF (0.0345, 0.0432 vs 0.0164, 0.0186, p < 0.05) and daily duration of NSVT (0.1982, 0.2845 vs 0.0538, 0.1640 p < 0.05) were higher and longer than those in the pre-COVID-19 period. Regression modeling showed that the impact of COVID-19 pandemic lead to an increased onset of AF (odds ratio 2.465; p < 0.01). Patients with paroxysmal AF who had undergone a previous radiofrequency ablation had a lower burden of AF (incidence 21.43% vs 55.00%, P = 0.049, daily frequency 0.0000, 0.0027 vs 0.0000, 241.7978, P = 0.020) during the pandemic.ConclusionThe COVID-19 pandemic contributed to a higher burden of arrhythmias in non-infected patients. Patients would experience a lower burden of AF following radiofrequency ablation treatment, and this effect persisted during the pandemic.

Environmental surveillance of SARS-CoV-2 RNA in wastewater systems and related environments in Wuhan: April to May of 2020

Wastewater-based epidemiology (WBE) has emerged as an effective environmental surveillance tool in monitoring fecal-oral pathogen infections within a community. Congruently, SARS-CoV-2, the etiologic agent of COVID-19, has been demonstrated to infect the gastrointestinal tissues, and be shed in feces. In the present study, SARS-CoV-2 RNA was concentrated from wastewater, sludge, surface water, ground water, sediment, and soil samples of municipal and hospital wastewater systems and related environments in Wuhan during the COVID-19 middle and low risk periods, and the viral RNA copies quantified using reverse transcription quantitative polymerase chain reaction (RT-qPCR). From the findings of this study, during the middle risk period, one influent sample and three secondary effluents collected from waste water treatment plant 2, as well as two samples from Jinyintan Hospital wastewater system influent were SARS-CoV-2 RNA positive. One sludge sample collected from Guanggu Branch of Tongji Hospital, which was obtained during the low risk period, was also positive for SARS-CoV-2 RNA. These study findings demonstrate the significance of WBE in continuous surveillance of SARS-CoV-2 at the community level, even when the COVID-19 prevalence is low. Overall, this study can be used as an important reference for contingency management of wastewater treatment plants and COVID-19 prevention and control departments of Wuhan.

Temporal Patterns and Hotspot Identification of Vehicle Collisions with the Roe Deer (Capreolus pygargus) on Jeju Island, South Korea

Wildlife–vehicle collisions (WVCs) are increasing worldwide, posing a threat to both humans and wildlife in terms of human injury and loss of wildlife. Understanding the temporal and spatial non-randomness of WVCs is an essential process for effective WVC management. Roe deer (Capreolus pygargus) is the most prevalent wildlife species in WVCs on Jeju Island, South Korea. This study analyzed individual temporal patterns and spatial hotspots (clusters) based on roe deer–vehicle collisions (RDVC) on Jeju Island from 2014 to 2017. RDVCs occur frequently from July to October, and RDVCs are higher in male deer than with females in all seasons, except in winter. The clusters in the high-risk periods were more regionally distributed compared to the clusters in the low-risk periods. Regardless of the period, some road sections have been identified as crucial clusters that should be given priority for road fencing to mitigate human-deer conflicts. Our findings could also provide road administrators with practical options for management such as temporarily imposing vehicle speed limits and installing signboards.

Climate Extreme Seeds a New Domoic Acid Hotspot on the US West Coast

A heatwave that blanketed the northeast Pacific Ocean in 2013–2015 had severe impacts on the marine ecosystem through altered species composition and survival. A direct result of this marine heatwave was a sustained, record-setting harmful algal bloom (HAB), caused by the toxigenic diatom, Pseudo-nitzschia, that led to an unprecedented delay in harvest opportunity for commercial Dungeness crab (Metacarcinus magister) and closure of other recreational, commercial and tribal shellfish harvest, including razor clams. Samples collected during a cruise in summer 2015, showed the appearance of a highly toxic “hotspot” between Cape Mendocino, CA and Cape Blanco, OR that was observed again during cruises in the summers of 2016–2018. The transport of toxic cells from this retentive site northward during wind relaxations or reversals associated with storms resulted in economically debilitating delay or closure of Dungeness crab harvest in both northern California and Oregon in 2015–2019. Analyses of historic large-scale Pseudo-nitzschia HABs have shown that these events occur during warm periods such as El Niño, positive phases of the Pacific Decadal Oscillation, or the record-setting marine heatwave. In order to reduce the impacts of large-scale HABs along the west coast of North America, early warning systems have been developed to forewarn coastal managers. These early warning systems include the Pacific Northwest and California HAB Bulletins, both of which have documented elevated domoic acid and increased risk associated with the northern California hotspot. These early warnings enable mitigative actions such as selective opening of safe harvest zones, increased harvest limits during low risk periods, and early harvest in anticipation of impending HAB events. The aims of this study are to show trends in nearshore domoic acid along the US west coast in recent years, including the recent establishment of a new seed bed of highly-toxic Pseudo-nitzschia, and to explore how early warning systems are a useful tool to mitigate the human and environmental health and economic impacts associated with harmful algal blooms.

Moulding the ideal crab: implications of phenotypic plasticity for crustacean stock enhancement

Abstract Numerous examples of behavioural and morphological differences between hatchery-cultured and wild individuals exist for a range of crustacean species; however, we submit that these variances are not deficiencies, but rather are adaptive responses to an unnatural rearing environment that may be detrimental in the natural environment. This phenotypic plasticity could be beneficial for stock enhancement because such plasticity suggests potential for change with adjustments to rearing protocols to achieve improved ecological competence. We examine how specific plastic responses can affect crustacean ecology through effects on predation, foraging, competition, and reproduction. For developing stock enhancement programmes, we recommend consideration of plastic phenotypic patterns before large-scale releases are initiated. Researchers can identify environmental factors that cue plasticity during hatchery rearing, determine if induced responses are ecologically influential after release into the wild, and examine the temporal scale on which phenotypic plasticity operates. Communal hatchery rearing at low-to-medium stocking densities with predator cues and natural substrates along with in situ conditioning, releases during periods of low predation risk, and coupled laboratory-field studies can contribute to improved ecological performance during stock enhancement. Finally, presentation of non-significant research results is needed to avoid bias towards hatchery–wild differences and help guide future conditioning programmes.

Modeling HIV Pre-Exposure Prophylaxis.

Pre-exposure prophylaxis (PrEP) has emerged as a promising strategy for preventing the transmission of HIV. Although only one formulation is currently approved for PrEP, research into both new compounds and new delivery systems for PrEP regimens offer intriguing challenges from the perspective of pharmacokinetic and pharmacodynamic modeling. This review aims to provide an overview the current modeling landscape for HIV PrEP, focused on PK/PD and QSP models relating to antiretroviral agents. Both current PrEP treatments and new compounds that show promise as PrEP agents are highlighted, as well as models of uncommon administration routes, predictions based on models of mechanism of action and viral dynamics, and issues related to adherence to therapy. The spread of human immunodeficiency virus (HIV) remains one of the foremost global health concerns. In the absence of a vaccine, other prophylactic strategies have been developed to prevent HIV transmission. One approach, known as pre-exposure prophylaxis (PrEP), allows HIV-negative individuals who are at high risk of exposure to the virus, be it through an HIV-positive sexual partner or through the shared use of drug injection equipment, to substantially reduce the risk of developing an HIV infection. PrEP is a relatively recent approach to combating the HIV epidemic, with the only currently approved treatment being Truvada, a daily oral antiretroviral (ARV) therapy initially indicated in the treatment of active HIV-1 infections, but approved for HIV PrEP in 2012. Although PrEP therapy has consistently demonstrated high efficacy in preventing HIV infection, this efficacy is dependent on patient adherence to the prescribed treatment regimen. This can present a significant problem in low- and middle-income countries, which may lack the infrastructure to provide sufficient access to PrEP medication to maintain daily dosing regimens. Furthermore, while the conventional approach has generally been to advocate for continuous administration akin to regimens used for viral suppression in infected patients, there has been some discussion of whether a better treatment paradigm might be to push for PrEP therapy primarily during those known periods of heightened exposure risk, while relying on post-exposure prophylaxis regimens to prevent infection after unanticipated exposures during low-risk periods. These considerations have led to a push for the development of long-duration and on-demand PrEP formulations, including subdermal and subcutaneous implants, slow-release intramuscular depot injections, vaginal and rectal antimicrobial gels, and intravaginal rings and dissolving films. PrEP therapy is a quickly evolving field, with a variety of antiretroviral compounds and formulations under investigation. This review aims to report on notable drugs and formulations from a pharmacokinetic/pharmacodynamic (PK/PD) modeling perspective. Given the nature of PrEP as a preventive therapy designed for long-term use, clinical trials for PrEP therapies can last for months or even years, particularly in the case of long-duration formulations. Furthermore, in contrast to antiretroviral trials in infected patients, pharmacodynamic endpoints in PrEP therapies are difficult to quantify, as the primary endpoint for efficacy is generally the rate of seroconversion. Computational modeling approaches offer flexible and powerful tools to provide insight into drug behavior in clinical settings, and can ultimately reduce the time, expense, and patient burden incurred in the development of PrEP therapies.

A Mondrian matrix of seasonal patterns of Culicoides nulliparous and parous females at different latitudes in Spain

Insects from genus Culicoides (Diptera; Ceratopogonidae) transmit arboviruses such as Bluetongue virus (BTV); affecting wild and domestic ruminants. These insects are age graded for monitoring purposes in surveillance programs. Parous females (PF) are the only fraction of the entire population that could effectively transmit viruses in a subsequent blood meal. Data of the Spanish Entomosurveillance National Program from 2008 to 2010 were used to analyse the seasonal pattern of the nulliparous females (NF) and PF of the vector species Obsoletus complex, C. imicola, C. newsteadi and C. pulicaris. Latitude variation on the seasonal abundance patterns of PF was also analysed in trap sites spanning a North-South axis in mainland Spain. The weekly abundance of PF was always highest in summer. The peak of abundance mainly occurred between April and July except for C. imicola that was from September to November. The analysis of the latitudinal seasonal variation of PF in Spain showed that Northern provinces have absence of C. imicola while the Obsoletus species were more present in Northern areas. There were periods of the year were no individuals of any vector species were collected, which should be considered in order to calculate the Seasonally Vector-Free Period (SVFP). Culicoides newsteadi and C. pulicaris exhibited the highest population in Toledo, probably related to their inland preferences. These findings would be of interest for a better understanding of the periods of low and high risk of transmission of BTV in Spain.

Developing a Rainfall-Based Index for Corn Crop Insurance in Isabela, Philippines

Corn, also known as maize, is one of the most important agricultural products produced by countries worldwide. Production of this crop is highly affected by climate change, especially if the water demand is not reach. With this, a rainfall-based index for crop insurance is an instrument to help farmers lower their risks in planting. The main objective of this study was to develop a rainfall-based index for corn crop insurance. Specifically, this study identified the threshold values for the index and estimated the probability of corn crop failure in the province of Isabela, Philippines. This study utilized Kolmogorov-Smirnov Test, Chi-Square Goodness of Fit Test, and Anderson-Darling Goodness of Fit Test to determine the probability distribution that best fits the data through Easyfit software and StatAssist, a built-in software in Easyfit to evaluate the probability of corn crop failure. The probability of crop failure for each stage of corn growth was obtained and based from the results, low-risk planting periods were found be: May to November for early crop growth stage, April and June to September for rapid crop growth stage, May to August for reproductive stage, and April to July for maturity stage. High-risk planting periods were found to be: January to March for early crop growth stage, January to March, May, November and December for rapid crop growth stage, January, February and October to December for the reproductive stage, and January, September to December for maturity stage.

1273. Reasons for Disengagement in Care among Individuals Receiving Pre-Exposure Prophylaxis (PrEP) from a Sexual Health Clinic

BackgroundPre-exposure prophylaxis (PrEP) effectively reduces HIV acquisition, but its efficacy depends on continued engagement through periods of high and low risk. Persistence in HIV prevention care has been low in real-world settings. In our program, 32% of patients are lost to care after their first visit and only 35% of patients are retained at their planned third visit. Reasons for low persistence in care are poorly described.MethodsWe identified all MSM who started PrEP between July 2015 and June 2018 at a sexual health clinic in an urban academic medical center in New York and had not had a visit in ≥6 months. We called patients between July 2018 and January 2019; those who were English speaking were given the option to complete an online questionnaire about current PrEP status, reasons for disengagement, and social and behavioral determinants of health (SBDH).ResultsUp to 710 patients were eligible for the study; over 700 calls were made. 125 participants agreed to participate and 57 (46%) completed the questionnaire. 24 patients (42%) were still actively taking PrEP. The most common reasons for starting PrEP were fear of getting HIV (58%), high self-perceived HIV risk (28%), and recommendations from friends (26%). Among those no longer taking PrEP, the most common reasons for discontinuation were cost/insurance issues (32%), lower perceived HIV risk (18%), concern about long-term side effects (12%), and trouble attending every-3-month appointments (12%). For those stopping due to lower perceived risk, 40% were in a monogamous relationship, 60% were less sexually active, and 20% always used a condom or did not engage in receptive anal intercourse. 56% of patients had at least 1 major life event in the preceding 3 months, including loss of a job (25%), breakup with a partner (12%), illness or death of a family member (11%), or unstable housing (8%). 47% used drugs or alcohol before sex in the past month including 39% not on PrEP.ConclusionReasons for engagement, disengagement, and re-engagement are highly variable at the individual level. Cost and insurance issues were common in spite if clinic resources available to cover the cost of visits and medications. Life trauma was common. Individualized interventions to address SBDH may be required to engage and retain individuals in HIV prevention care.Disclosures All authors: No reported disclosures.

Cross-asset relations, correlations and economic implications

This paper examines the interrelations and time-varying correlations for eight assets. One-year rolling correlations reveal that each of the 28 correlations exhibit both positive and negative values. Linear regressions reveal that given macroeconomic and financial variables contain predictive power for different asset return correlations. The term structure of interest rates and consumer sentiment feature as prominent predictor variables. Structural break tests and non-linear regressions indicate a cycling of correlations between high and low risk periods. In seeking to consider the economic content of the interrelations, we construct a safe and risky portfolio and show that the correlation between these portfolios can allow for improved market timing. Further, the safe and risky portfolio returns and correlation exhibit predictive power for macroeconomic conditions and may be used in a leading indicator role. The results presented here should be of interest to investors and policy-makers as well as academics wishing to examine the relations between both asset returns and financial and real markets.

Adjustments in compound defensive strategies in response to variation in predation risk

Predation risk varies between populations and fluctuates with time. Using a theoretical approach, I studied how differences in this predation regime may influence allocation to antipredator defence in a foraging prey. I considered a set of two complementary defensive tactics, namely, the possibility for the prey to shorten its activity periods, to reduce exposure to predatory attacks and sacrifice some of its foraging time to vigilance, to get a better chance of escaping when under attack. The model reveals relatively complex behavioural adaptations, with important consequences for the energy balance of the animal. In particular, a hierarchy emerges between the two levels of decisions and, as a consequence, the two types of defensive tactics do not respond in a uniform way to changes in environmental conditions. Animals living in relatively safe habitats are thus expected to devote all their time to foraging and adjust their vigilance to the level of risk they endure, while animals living in more dangerous places are expected to adjust the length of their foraging periods to the prevailing level of risk. If the level of risk varies, the animals will avoid being active during infrequent, or particularly deadly, high-risk periods. If these periods become more frequent, or less dangerous, the animals will be fully active, and adjust their vigilance, during low-risk periods, and only partially active during high-risk periods. Finally, when dangerous periods further increase in length or decrease in intensity, the animals will use all available foraging time, and adjust their vigilance during both low- and high-risk periods to the predation regime. Antipredator strategies must then be perceived as a set of behavioural decisions, not only connected to one another, but also embedded within one another, which mediate energy transfers between three consecutive trophic levels.