Multiple-day Periods Research Articles

Health issues and healthcare utilization among adults who reported exposure to tear gas during 2020 Portland (OR) protests: a cross-sectional survey

BackgroundRepeated use of chemical irritants for crowd-control by local and federal law enforcement during sustained racial justice protests in the U.S. has raised concerns about potential adverse health effects. The objective of this study was to describe the health consequences of exposure to tear gas agents and associated healthcare utilization among adults reporting recent exposure to tear gas.MethodsA cross-sectional, self-administered web-based survey of a convenience sample of 2257 adults reporting recent exposure to tear gas in Portland, Oregon (U.S.), administered between July 30, 2020-August 20, 2020. Descriptive analyses were conducted on socioeconomic characteristics, reported health issues, utilization of healthcare services, and frequency of reported exposure to tear gas. Associations between reported mental health issues, healthcare utilization and race and/or ethnic categories were assessed using a chi-square test. For tests of association, racial and/or ethnic categories were divided into White/Non-Hispanic only and all other racial/ethnic categories due to a small number of Black, American Indian or Alaska Native, Asian/Pacific Islander, Hispanic participants and participants with multiple race and/or ethnic background. Effect sizes for the differences were expressed as Cramer’s V, a metric that measures associations between nominal responses. The Cochran-Armitage trend test was used to assess the relationship between health issues and the number of reported days of exposure to tear gas (i.e., a proxy dose of exposure) grouped into 1 day, 2–4 days, and ≥ 5 days. Missing data (item non-response) were omitted from the analysis.ResultsAlmost all respondents (2116; 93.8%) reported physical (2114; 93.7%) or psychological (1635; 72.4%) health issues experienced immediately after (2105; 93.3%) or days following (1944; 86.1%) the exposure. A slightly higher proportion experienced delayed head or gastrointestinal tract issues compared with immediate complaints. The majority (1233; 54.6%) reported receiving or planning to seek medical or mental care. We observed a positive exposure-response trend for all except mouth-related delayed issues (p < 0.01).ConclusionPersons who reported exposer to tear gas agents also reported physical and psychological health issues over a multiple-day period. Health issues reported increased with the frequency of reported exposure, indicating a potential dose-response; these health effects often led to healthcare utilization. This study provides evidence of potential unexpected harms of tear gas in civilians.

Technical note: Continuous fluorescence-based monitoring of seawater pH in situ

Abstract. Electrical conductivity (salinity), temperature and fluorescence-based measurements of pH were employed to examine diel fluctuations in seawater carbonate chemistry of surface waters in Sydney Harbour over two multiple-day periods. A proof-of-concept device employing the fluorescence-based technique provided a useful time series for pH. Alkalinity with pH and temperature were used to calculate the degree of calcite and aragonite saturation (ΩCa and ΩAr, respectively). Alkalinity was determined from a published alkalinity–salinity relationship. The fluctuations observed in pH over intervals of minutes to hours could be distinguished from background noise. While the stated phase angle resolution of the lifetime fluorometer translated into pH units was ±0.0028 pH units, the repeatability standard deviation of calculated pH was 0.007 to 0.009. Diel variability in pH, ΩAr and ΩCa showed a clear pattern that appeared to correlate with both salinity and temperature. Drift due to photodegradation of the fluorophore was minimized by reducing exposure to ambient light. The ΩCa and ΩAr fluctuated on a daily cycle. The net result of changes in pH, salinity and temperature combined to influence seawater carbonate chemistry. The fluorescence-based pH monitoring technique is simple, provides good resolution and is unaffected by moving parts or leaching of solutions over time. The use of optics is pressure insensitive, making this approach to ocean acidification monitoring well suited to deepwater applications.

On the Significance of Multiple Consecutive Days of Tornado Activity

Abstract Motivated by the temporal behavior of recent high-end tornado events, a 30-yr historical record of tornadoes in the United States is examined for multiple-day periods of tornado activity. Comprising the 3129 tornado days during 1983–2012 are 1406 unique, nonoverlapping periods. Only 24% of these periods have lengths of 3 or more days. However, the conditional probability of such a multiday period given an outbreak day (OB; one with 20 or more tornado reports) is 74%, and given a significant tornado day [SIGTOR; one rated Fujita/enhanced Fujita (F/EF) ≥ 3] is 60%. Alternative ways of expressing these conditional probabilities all lead to the conclusion that SIGTORs and/or OBs are more likely to be contained within multiday periods of tornadoes than within 1–2-day periods. Two additional conclusions are offered: 1) SIGTORs and OBs have a relatively higher likelihood of occurrence during the latter half of the multiday periods, and 2) multiday periods have a relatively higher likelihood of occurrence during the warm months of April–July. A hypothesized connection, illustrated using reanalysis data from 2013, is proposed between such behaviors and the characteristics of the larger-scale meteorological forcing. Some speculations are made about possible relationships between multiday periods of tornado activity and convective feedbacks, extended predictability, and modes of internal climate variability.

Design and Implementation of an Internet-Based Household Activity Scheduling Survey in Cairo, Egypt

AbstractThis paper reports on the design and implementation of an internet-based survey that focuses on household activity scheduling in Cairo, Egypt. The survey is referred to as Internet-based daily activity scheduling of household activities (IDASHA). The main emphasis of the survey was on different types of household interactions and coordination over a multiple-day period. The survey also collected detailed information about information and communication technology (ICT) usage and the role that telecommunications play in household interactions in the planning and scheduling process. The survey was conducted over one week during the months of March to May 2009. The final sample size included 42 households of married couples (i.e., 84 adults). The survey was evaluated according to several criteria, and was shown to provide a rich source of data while minimizing the burden on the survey respondents. Moreover, statistical analyses were carried out to investigate several issues such as time allocation beh...

Ecological Momentary Assessment of Maternal Cortisol Profiles Over a Multiple-Day Period Predicts the Length of Human Gestation

Biobehavioral models of prenatal stress highlight the importance of the stress-related hormone cortisol. However, the association between maternal cortisol levels and the length of human gestation requires further investigation because most previous studies have relied on one-time cortisol measures assessed at varying gestational ages. This study assessed whether ecological momentary assessment (EMA) of cortisol sampling improves the ability to predict the length of human gestation. In addition, associations between EMA-based measures of psychological state (negative affect) with cortisol levels during pregnancy were assessed. For a 4-day period, 25 healthy pregnant women (mean gestational age at assessment = 23.4 [standard deviation = 9.1] weeks) collected seven salivary samples per day for the assessment of cortisol and provided a rating of negative affect every waking hour using an electronic diary. Higher salivary cortisol concentrations at awakening and throughout the day (p = .001), as well as a flatter cortisol response to awakening (p = .005), were associated with shorter length of gestation. Women who delivered an infant at 36 weeks of gestations had 13% higher salivary cortisol levels at awakening than women who delivered an infant at 41 weeks of gestation. The EMA-based measure of negative affect was associated with higher cortisol throughout the day (p = .006) but not to gestational length (p = .641). The one-time measure of cortisol was not associated with length of gestation, and traditional retrospective recall measures of negative affect were not associated with cortisol. Our findings support the ecological validity of repeated ambulatory assessments of cortisol in pregnancy and their ability to improve the prediction of adverse birth outcomes.

156: Repeated ambulatory assessments of maternal cortisol over a multiple-day period predict length of gestation and birth weight

Empirical evidence suggests that high levels of prenatal stress exposure in pregnancy constitute an independent risk factor for adverse birth outcomes. Stress is known to activate the hypothalamic-pituitary-adrenal (HPA) axis, resulting in an increase in cortisol levels. However, most studies assess single measures of stress hormones, there is considerable variation in hormone levels, and one-time measures of stress hormones are inconsistently associated with adverse outcomes. The present study used a novel ecological momentary assessment protocol to investigate whether inter-individual differences in cortisol concentrations during pregnancy measured repeatedly over multiple days in womens′ natural, everyday settings were associated with length of gestation and birth weight.

Acoustic Identification and Measurement of Activity Patterns of White Grubs in Soil

Activity patterns of Phyllophaga crinita (Burmeister), Phyllophaga congrua (LeConte), Phyllophaga crassissima (Blanchard), and Cyclocephala lurida (Bland) grubs were monitored with acoustic sensors in small pots of bluegrass, Poa arachnifera Torr, at varying and constant temperatures over multiple-day periods. Experienced listeners readily distinguished three types of sound with distinct differences in frequency and temporal patterns, intensities, and durations. Of ≈3,000 sounds detected from P. crinita larvae, 7% were identifiable as snaps, with large amplitudes and short durations typically associated with root breakage or clipping activity. Approximately 60% were identifiable as rustles, suggestive of surfaces sliding or rubbing past each other during general movement activity. Another 2% of sounds contained patterns of repeated pulses suggestive of surfaces scraping across a pointed ridge. The remaining 31% had spectral or temporal patterns that fell outside the ranges of easily recognizable sound types. Because the behavioral significance of the different sound types has not yet been fully established, the classified and unclassified sounds were pooled together in analyses of the effects of species, temperature, weight, and time of day. Grubs of all four species produced detectable sounds at rates that increased with temperature [0.45 sounds/((min)(°C))] and larval weight [6.3 sounds/((min)(g))]. Mean sound rates were independent of species and time of day. At temperatures <9°C, mean sound rates fell below the typical levels of background noise observed under field conditions. This reduced activity at low temperatures is likely to reduce the effectiveness of acoustic monitoring in the field in cold weather. The consistency of results obtained in these tests over multiple-day periods suggests that acoustic systems have potential as tools for nondestructive monitoring of the efficacy of insect management treatments as well as for biological and ecological studies.

Estimation of incremental reactivities for multiple day scenarios: an application to ethane and dimethyoxymethane

Single-day scenarios are used to calculate incremental reactivities by definition (Carter, J. Air Waste Management Assoc. 44 (1994) 881–899.) but even unreactive organic compounds may have a non-negligible effect on ozone concentrations if multiple-day scenarios are considered. The concentration of unreactive compounds and their products may build up over a multiple-day period and the oxidation products may be highly reactive or highly unreactive affecting the overall incremental reactivity of the organic compound. We have developed a method for calculating incremental reactivities for multiple days based on a standard scenario for polluted European conditions. This method was used to estimate maximum incremental reactivities (MIR) and maximum ozone incremental reactivities (MOIR) for ethane and dimethyoxymethane for scenarios ranging from 1 to 6 days. It was found that the incremental reactivities increased as the length of the simulation period increased. The MIR of ethane increased faster than the value for dimethyoxymethane as the scenarios became longer. The MOIRs of ethane and dimethyoxymethane increased but the change was more modest for scenarios longer than 3 days. MOIRs of both volatile organic compounds were equal within the uncertainties of their chemical mechanisms by the 5 day scenario. These results show that dimethyoxymethane has an ozone forming potential on a per mass basis that is only somewhat greater than ethane if multiple-day scenarios are considered.

Pollen recovery in atmospheric samples collected with the Rotorod Sampler over multiple-day periods such as weekends.

Conventional wisdom holds that multiple-day samples should not be obtained with the Rotorod Sampler because sampling efficiency declines over long sampling periods such as weekends. The purpose of this present investigation was to test this position under experimental conditions. Atmospheric pollen samples were collected over 24-hour, 48-hour, and 72-hour periods by five Rotorod Samplers operated in a compact sampling array. Pollen counts obtained from the latter two sampling periods were compared with corresponding values computed from 24-hour samples. Differences in pollen recovery were assessed using Pearson's correlation coefficient and paired comparisons t-tests. Two hundred seventeen atmospheric samples were obtained between March 30 and October 8, 1998. Differences between the 48-hour and 72-hour samples and their computed counterparts were not statistically significant when the atmospheric pollen concentration was less than 100 pollen grains per cubic meter of air (p/m3). At higher pollen concentrations large quantitative and statistically significant differences were noted. These data suggest that particle loading on Rotorod collector rods caused sample quality to deteriorate when atmospheric pollen concentrations exceed 100 p/m3. Multiple-day sampling periods appear to be justified when the atmospheric pollen concentration is less than this threshold. Adjusting the Rotorod Sampler's duty cycle may offer a means to collect samples over periods longer than 24 hours during times of the year when pollen shed is heavy.

Tests for cumulative abnormal returns over long periods: Simulation evidence

The usual test of cumulative abnormal returns for multiple-day periods assumes that abnormal returns are serially independent. The assumption imparts an upward bias to test statistics even when raw returns are serially independent. In simulation, the usual test rejects true null hypotheses too frequently in the longest cumulation periods and in shorter periods when events are clustered in calendar time. Excessively frequent rejection implies that the nominal significance level understates the actual significance level. A corrected statistic, derived without the serial independence assumption, rejects true null hypotheses with a frequency less than or equal to the nominal significance level. However, the corrected test is not very powerful in the longest event periods.

The effect of value line investment survey rank changes on common stock prices

Abstract The information content of Value Line Investment Survey rank changes is investigated. The results suggest rank changes affect common stock prices, but the effect varies by the type of rank change. Changes from rank 2 to rank 1 have the most dramatic impact on prices. A cross-sectional analysis finds small firms have a greater reaction to a rank change than larger firms, which supports theories on the frequency of report arrival and precision of information. A speed of adjustment test concludes the prices of individual securities adjust to the information in a rank change over a multiple-day period.