A Multiproxy Database of Western North American Holocene Paleoclimate Records

Holocene climate reconstructions are useful for understanding the diverse features and spatial heterogeneity of past and future climate change. Here we present a database of western North American Holocene paleoclimate records. The database gathers paleoclimate time series from 184 terrestrial and marine sites, including 381 individual proxy records. The records span at least 4000 of the last 12 000 years (median duration of 10 725 years) and have been screened for resolution, chronologic control, and climate sensitivity. Records were included that reflect temperature, hydroclimate, or circulation features. The database is shared in the machine readable Linked Paleo Data (LiPD) format and includes geochronologic data for generating site-level time-uncertain ensembles. This publicly accessible and curated collection of proxy paleoclimate records will have wide research applications, including, for example, investigations of the primary features of ocean-atmospheric circulation along the eastern margin of the North Pacific and the latitudinal response of climate to orbital changes. The database is available for download at https://doi.org/10.6084/m9.figshare.12863843.v1 (Routson and McKay, 2020)

Description of the Baseline Audiologic Characteristics of the Participants Enrolled in the Aging and Cognitive Health Evaluation in Elders Study

Purpose:The Aging and Cognitive Health Evaluation in Elders (ACHIEVE) study is a randomized clinical trial designed to determine the effects of a best-practice hearing intervention versus a successful aging health education control intervention on cognitive decline among community-dwelling older adults with untreated mild-to-moderate hearing loss. We describe the baseline audiologic characteristics of the ACHIEVE participants.Method:Participants aged 70–84 years (N = 977; Mage = 76.8) were enrolled at four U.S. sites through two recruitment routes: (a) an ongoing longitudinal study and (b) de novo through the community. Participants underwent diagnostic evaluation including otoscopy, tympanometry, pure-tone and speech audiometry, speech-in-noise testing, and provided self-reported hearing abilities. Baseline characteristics are reported as frequencies (percentages) for categorical variables or medians (interquartiles, Q1–Q3) for continuous variables. Between-groups comparisons were conducted using chi-square tests for categorical variables or Kruskal–Wallis test for continuous variables. Spearman correlations assessed relationships between measured hearing function and self-reported hearing handicap.Results:The median four-frequency pure-tone average of the better ear was 39 dB HL, and the median speech-in-noise performance was a 6-dB SNR loss, indicating mild speech-in-noise difficulty. No clinically meaningful differences were found across sites. Significant differences in subjective measures were found for recruitment route. Expected correlations between hearing measurements and self-reported handicap were found.Conclusions:The extensive baseline audiologic characteristics reported here will inform future analyses examining associations between hearing loss and cognitive decline. The final ACHIEVE data set will be publicly available for use among the scientific community

Diversity and distribution of marcrophytes in a freshwater wetland, Loboi swamp (Rift valley), Kenya

An inventory of Loboi swamp was undertaken to determine the macrophyte diversity and distribution. A total of 36 vascular plant species in 13 families were recorded, with Cyperaceae forming over 30% of macrophytes. Two vegetation zones were observed, characterised by the presence of Typha and papyrus. The Typha zone, comprising over 70% of the swamp, is dominated by T. domingensis and is species rich with 35 plant species whereas the papyrus zone includes the dominant Cyperus papyrus and only one other macrophyte species. Distribution of macrophytes is correlated with depth and period under water, with the Typha zone seasonally flooded while the papyrus zone is permanently under water at depths over 0.5m. Water chemistry has little influence on the distribution of macrophytes in the swamp, but at the edges there is predominance of Cyperus laevigatus in high alkalinity soils. Current uses of the swamp include dry season grazing, harvesting of papyrus and other plant material for mat making and house thatching, and use of the swamp water for domestic and irrigation agriculture. Further monitoring is needed to evaluate the effect of the resource uses on the swamp..Journal of East African Natural History Vol. 93 (1&2) 2004: pp. 39-4