Effect of Carelink, an Internet-Based Insulin Pump Monitoring System, on Glycemic Control in Children with Type 1 Diabetes Mellitus

Objective : To determine whether use of the internet-based Carelink system improved glycemic control in children on insulin pump therapy. Research Design and Methods - We reviewed records of 146 children treated with insulin pump therapy between the years 2004-2007, and compared glycemic control and diabetes self-care measures associated with Carelink use. Forty percent of the patients resided one hour or more from our clinic. Results: Patients who used the Carelink software and website showed significant improvement in HbA1c levels following use (8.0 ± 0.1 (SE) vs 7.7 ± 0.1 (SE), p=0.002). They uploaded data from their pump and glucometer 2.2 ± 1.8 times per month over 0.8 ± 0.4 (SD) years. Patients who had no access to Carelink software and were followed in a conventional manner showed no change in HbA1c ( 8.0 ± 0.1 (SE) vs 8.1 ± 0.1 (SE), p=0.27) during the study period. These patients did not differ significantly from Carelink users in diabetes self care behaviors. Patients who had Carelink access but did not use it had a higher HbA1c level at the onset and did not change over the study period (HbA1c 8.9 ± 0.2 (SE) vs 8.9 ± 0.3 (SE), p=0.76). These patients differed significantly from Carelink users in self-care behaviors, but not in the frequency of blood glucose monitoring. Patients in a rural location benefited equally as compared to patients who lived within one hour of our clinic. Conclusions: The Carelink software program is a powerful tool that can be used by diabetes care providers and parents to manage insulin pump therapy in children and to improve glycemic control, especially in states with a large rural population

Environmental DNA of aquatic macrophytes: The potential for reconstructing past and present vegetation and environments

1. Environmental DNA is increasingly being used to reconstruct past and present biodiversity including from freshwater ecosystems. Macrophytes are especially good environmental indicators, thus their environmental DNA palaeorecord might shed light on past postglacial environments. 2. Here, we first review and compare studies that use metagenomics, targeted capture, and various barcoding and metabarcoding markers, in order to explore how each of these methods can be used to capture aquatic vegetation diversity and change. We then investigate the extent to which such a record can be leveraged for reconstructing local environmental conditions, using a case study based on macrophyte ecological niches. 3. We find that, with state-of-the-art DNA barcode reference libraries, using metabarcoding to target the P6 loop region of the chloroplast trnL (UAA) intron is optimal to maximise taxonomic resolution and the diversity of past macrophyte communities. Shotgun sequencing also retrieves a high proportion of aquatic macrophyte diversity, but has the lowest taxonomic resolution, and targeted capture needs to be more widely applied before comparisons can be made. 4. From our case study, we infer past aquatic habitats from sedimentary ancient DNA records of macrophyte taxa. We reconstructed Holocene thermal range, continentality, water pH, trophic status, and light conditions in northern Fennoscandia. We show an overall stability since 9,000 years ago, even though individual lakes display different trends and variation in local climatic and physicochemical conditions. 5. Combined with the availability of near-exhaustive barcode and traits databases, metabarcoding data can support wider ecological reconstructions that are not limited to aquatic plant taxonomic inventories but can also be used to infer past changes in water conditions and their environmental drivers. Sedimentary DNA is also a powerful tool to measure present diversity, as well as to reconstruct past lacustrine and fluvial communities of aquatic macrophytes

Holocene floristic diversity and richness in northeast Norway revealed by sedimentary ancient DNA (sedaDNA) and pollen

Source at https://doi.org/10.1111/bor.12357We present a Holocene record of floristic diversity and environmental change for the central Varanger Peninsula, Finnmark, based on ancient DNA extracted from the sediments of a small lake (sedaDNA). The record covers the period c. 10 700 to 3300 cal. a BP and is complemented by pollen data. Measures of species richness, sample evenness and beta diversity were calculated based on sedaDNA sampling intervals and 1000‐year time windows. We identified 101 vascular plant and 17 bryophyte taxa, a high proportion (86%) of which are still growing within the region today. The high species richness (>60 taxa) observed in the Early Holocene, including representatives from all important plant functional groups, shows that modern shrub‐tundra communities, and much of their species complement, were in place as early as c. 10 700 cal. a BP. We infer that postglacial colonization of the area occurred prior to the full Holocene, during the Pleistocene‐Holocene transition, Younger Dryas stadial or earlier. Abundant DNA of the extra‐limital aquatic plant Callitriche hermaphroditica suggests it expanded its range northward between c. 10 200 and 9600 cal. a BP, when summers were warmer than present. High values of Pinus DNA occur throughout the record, but we cannot say with certainty if they represent prior local presence; however, pollen influx values >500 grains cm−2 a−1 between c. 8000 and 7300 cal. a BP strongly suggest the presence of pine woodland during this period. As the site lies beyond the modern tree limit of pine, it is likely that this expansion also reflects a response to warmer Early Holocene summers

Holocene summer temperature reconstruction from plant sedaDNA and chironomids from the northern boreal forest

Climate-induced ecotonal shifts are expected to occur in the (sub)arctic and boreal zones in the coming decades. Understanding how these ecosystems have previously responded to climate change can provide greater insight into how ecosystems may develop under existing and future pressures. Here we present a Holocene record from Lake Horntjernet, a lake on the northern edge of the boreal forest in Northern Norway. We show vegetation development and landscape dynamics typical for Northern Fennoscandia during the Holocene. A plant sedaDNA record indicates rapid vegetation development following deglaciation with early arrival of Betula trees/shrubs. Pine forest was established by c. 8500 cal yr BP, and subsequent mid- to late Holocene vegetation assemblages are relatively stable. The aquatic ecosystem community is indicative of climatic change during the early Holocene, while strong coupling with changes in the catchment vegetation affects the water quality during the mid- and late Holocene. The chironomid record indicates lake water acidification following the establishment of pine forest and heathland. Different approaches for temperature reconstruction are calculated and the results are compared to better understand ecosystem-climate relationships and ecosystem resilience to climate change. Chironomid-inferred temperatures indicate early Holocene warming and late Holocene cooling, comparable to independent regional temperature trends. However, lake acidification impedes reliable reconstruction of chironomid-inferred temperatures in the mid-Holocene, a trend recognised in other boreal chironomid records. The application of sedaDNA plant-inferred summer temperature reconstruction is inhibited by the persistence of cold and warm tolerant species within the boreal pine forest. However, a trait-based approach reconstructed temperature trends that aligned with independent regional data. Thus, here we demonstrate the value of combined molecular and fossil-based proxies for elucidating the complex response of a boreal catchment to climate change

Postglacial species arrival and diversity buildup of northern ecosystems took millennia

What drives ecosystem buildup, diversity, and stability? We assess species arrival and ecosystem changes across 16 millennia by combining regional-scale plant sedimentary ancient DNA from Fennoscandia with near-complete DNA and trait databases. We show that postglacial arrival time varies within and between plant growth forms. Further, arrival times were mainly predicted by adaptation to temperature, disturbance, and light. Major break points in ecological trait diversity were seen between 13.9 and 10.8 calibrated thousand years before the present (cal ka BP), as well as break point in functional diversity at 12.0 cal ka BP, shifting from a state of ecosystem buildup to a state where most habitat types and biotic ecosystem components were in place. Trait and functional diversity stabilized around 8 cal ka BP, after which both remained stable, although changes in climate took place and species inflow continued. Our ecosystem reconstruction indicates a millennial-scale time phase of formation to reach stable and resilient levels of diversity and functioning.publishedVersio

Steppe-tundra composition and deglacial floristic turnover in interior Alaska revealed by sedimentary ancient DNA (sedaDNA)

When tracing vegetation dynamics over long timescales, obtaining enough floristic information to gain a detailed understanding of past communities and their transitions can be challenging. The first high-resolution sedimentary DNA (sedaDNA) metabarcoding record from lake sediments in Alaska—reported here—covers nearly 15,000 years of change. It shows in unprecedented detail the composition of late-Pleistocene “steppe-tundra” vegetation of ice-free Alaska, part of an intriguing late-Quaternary “no-analogue” biome, and it covers the subsequent changes that led to the development of modern spruce-dominated boreal forest. The site (Chisholm Lake) lies close to key archaeological sites, and the record throws new light on the landscape and resources available to early humans. Initially, vegetation was dominated by forbs found in modern tundra and/or subarctic steppe vegetation (e.g., Potentilla, Draba, Eritrichium, Anemone patens), and graminoids (e.g., Bromus pumpellianus, Festuca, Calamagrostis, Puccinellia), with Salix the only prominent woody taxon. Predominantly xeric, warm-to-cold habitats are indicated, and we explain the mixed ecological preferences of the fossil assemblages as a topo-mosaic strongly affected by insolation load. At ca. 14,500 cal yr BP (calendar years before C.E. 1950), about the same time as well documented human arrivals and coincident with an increase in effective moisture, Betula expanded. Graminoids became less abundant, but many open-ground forb taxa persisted. This woody-herbaceous mosaic is compatible with the observed persistence of Pleistocene megafaunal species (animals weighing ≥44 kg)—important resources for early humans. The greatest taxonomic turnover, marking a transition to regional woodland and a further moisture increase, began ca. 11,000 cal yr BP when Populus expanded, along with new shrub taxa (e.g., Shepherdia, Eleagnus, Rubus, Viburnum). Picea then expanded ca. 9500 cal yr BP, along with shrub and forb taxa typical of evergreen boreal woodland (e.g., Spiraea, Cornus, Linnaea). We found no evidence for Picea in the late Pleistocene, however. Most taxa present today were established by ca. 5000 cal yr BP after almost complete taxonomic turnover since the start of the record (though Larix appeared only at ca. 1500 cal yr BP). Prominent fluctuations in aquatic communities ca. 14,000–9,500 cal yr BP are probably related to lake-level fluctuations prior to the lake reaching its high, near-modern depth ca. 8,000 cal yr BP

Sedimentary ancient DNA shows terrestrial plant richness continuously increased over the Holocene in northern Fennoscandia

The effects of climate change on species richness are debated but can be informed by the past. Here, we generated a sedimentary ancient DNA dataset covering 10 lakes and applied novel methods for data harmonization. We assessed the impact of Holocene climate changes and nutrients on terrestrial plant richness in northern Fennoscandia. We find that richness increased steeply during the rapidly warming Early Holocene. In contrast to findings from most pollen studies, we show that richness continued to increase thereafter, although the climate was stable, with richness and the regional species pool only stabilizing during the past three millennia. Furthermore, overall increases in richness were greater in catchments with higher soil nutrient availability. We suggest that richness will increase with ongoing warming, especially at localities with high nutrient availability and assuming that human activity remains low in the region, although lags of millennia may be expected.The effects of climate change on species richness are debated but can be informed by the past. Here, we generated a sedimentary ancient DNA dataset covering 10 lakes and applied novel methods for data harmonization. We assessed the impact of Holocene climate changes and nutrients on terrestrial plant richness in northern Fennoscandia. We find that richness increased steeply during the rapidly warming Early Holocene. In contrast to findings from most pollen studies, we show that richness continued to increase thereafter, although the climate was stable, with richness and the regional species pool only stabilizing during the past three millennia. Furthermore, overall increases in richness were greater in catchments with higher soil nutrient availability. We suggest that richness will increase with ongoing warming, especially at localities with high nutrient availability and assuming that human activity remains low in the region, although lags of millennia may be expected.Peer reviewe

Integrating multi-taxon palaeogenomes and sedimentary ancient DNA to study past ecosystem dynamics

Ancient DNA (aDNA) has played a major role in our understanding of the past. Important advances in the sequencing and analysis of aDNA from a range of organisms have enabled a detailed understanding of processes such as past demography, introgression, domestication, adaptation and speciation. However, to date and with the notable exception of microbiomes and sediments, most aDNA studies have focused on single taxa or taxonomic groups, making the study of changes at the community level challenging. This is rather surprising because current sequencing and analytical approaches allow us to obtain and analyse aDNA from multiple source materials. When combined, these data can enable the simultaneous study of multiple taxa through space and time, and could thus provide a more comprehensive understanding of ecosystem-wide changes. It is therefore timely to develop an integrative approach to aDNA studies by combining data from multiple taxa and substrates. In this review, we discuss the various applications, associated challenges and future prospects of such an approach

High resolution ancient sedimentary DNA shows that alpine plant diversity is associated with human land use and climate change.

The European Alps are highly rich in species, but their future may be threatened by ongoing changes in human land use and climate. Here, we reconstructed vegetation, temperature, human impact and livestock over the past ~12,000 years from Lake Sulsseewli, based on sedimentary ancient plant and mammal DNA, pollen, spores, chironomids, and microcharcoal. We assembled a highly-complete local DNA reference library (PhyloAlps, 3923 plant taxa), and used this to obtain an exceptionally rich sedaDNA record of 366 plant taxa. Vegetation mainly responded to climate during the early Holocene, while human activity had an additional influence on vegetation from 6 ka onwards. Land-use shifted from episodic grazing during the Neolithic and Bronze Age to agropastoralism in the Middle Ages. Associated human deforestation allowed the coexistence of plant species typically found at different elevational belts, leading to levels of plant richness that characterise the current high diversity of this region. Our findings indicate a positive association between low intensity agropastoral activities and precipitation with the maintenance of the unique subalpine and alpine plant diversity of the European Alps

Community-curated and standardised metadata of published ancient metagenomic samples with AncientMetagenomeDir

Ancient DNA and RNA are valuable data sources for a wide range of disciplines. Within the field of ancient metagenomics, the number of published genetic datasets has risen dramatically in recent years, and tracking this data for reuse is particularly important for large-scale ecological and evolutionary studies of individual taxa and communities of both microbes and eukaryotes. AncientMetagenomeDir (archived at https://doi.org/10.5281/zenodo.3980833) is a collection of annotated metagenomic sample lists derived from published studies that provide basic, standardised metadata and accession numbers to allow rapid data retrieval from online repositories. These tables are community-curated and span multiple sub-disciplines to ensure adequate breadth and consensus in metadata definitions, as well as longevity of the database. Internal guidelines and automated checks facilitate compatibility with established sequence-read archives and term-ontologies, and ensure consistency and interoperability for future meta-analyses. This collection will also assist in standardising metadata reporting for future ancient metagenomic studies