1,369 research outputs found

    Spatial analysis of borrow pits along the Platte River in south-central Nebraska, USA, in 1957 and 2016

    Get PDF
    The Central Platte River Valley (CPRV) of Nebraska provides critical habitat for wildlife, while serving agricultural, indus­trial, and other human uses. Mining of sand and gravel from the floodplain of the Platte River has supported construction of roads and other uses, and this extraction has created many borrow-pit ponds, lakes, and other small bodies of standing water (hereafter borrow-pits), further transforming riparian and prairie habitats. The objective of this study was to compare the abundance, size, and distribution of borrow pits before construction of Interstate 80 (1957) and at present (2016) from Lexington to Chapman, Nebraska, a length of river spanning about 146 km (90 mi) and sometimes referred to as the Big Bend Reach. Orthorectified aerial imagery of the Platte River was obtained for years 1957 and 2016, and we digitized the standing bodies of water within the floodplain in Arc­GIS. Total numbers of borrow pits and measures of pit shape were calculated and compared between floodplain regions where im­agery overlapped. From 1957 to 2016, the number of borrow pits increased from 300 to 786, total area occupied by pits expanded by 538%, and total shoreline of pits increased by 261%. In 2016, aerial imagery was available for a larger extent of the floodplain and contained a total of 1,062 borrow pits covering 16 km2 (6 mi2), with a total shoreline of 581 km (361 mi). For context, the Platte River channels’ approximate area was 45 km2 (17 mi2) and shoreline 1,582 km (983 mi) between Lexington and Chapman, Nebraska, in 2016. Results provide insight into historical and current presence, distribution, and shape of borrow pits along the Platte River, as well as serve as a reference point for future studies investigating regional landscape change and ecological effects of creating hun­dreds of borrow pits on the floodplain

    Ten thousand voices on marine climate change in Europe: different perceptions among demographic groups and nationalities

    Get PDF
    Over the past few decades, substantial funding has been directed towards improving scientific understanding and management of impacts of climate change in the marine environment. Following concerns that the key messages from these studies were not reaching the public, a comprehensive opinion poll of 10,000 European citizens in 10 countries was conducted to establish levels of awareness, concern, and trust among different demographic groups (by age, gender, proximity to the coast) and nationalities. Citizens exhibited varying levels of self-declared ‘informedness’ and concern. Citizens from Germany, Italy and Spain claimed to be the most informed on marine climate change issues; those from Czech Republic, Netherlands and Estonia claimed to be least informed. Respondents were least aware of ocean acidification and most aware of melting sea ice, pollution and overfishing. Citizens of Italy suggested that they were generally most concerned about marine climate change issues. Respondents from coastal areas claimed to be both more informed and more concerned than those living inland, as did females and older age groups (54-64 years). European citizens obtain information about climate change in the seas and ocean from different sources, particularly television and the internet. Trust in the various media sources varies among countries and demographic groups. Television is trusted most in Estonia, Germany and Ireland and least in France. The internet is trusted most in Italy, Czech Republic and Estonia, but least in France and the United Kingdom. 18-24 year olds are the biggest users of the internet, but trust this source less than older age groups. Academic scientists or those working for environmental NGOs are trusted more than scientists working for government or industry. Citizens from France are more trusting of industry than any other country polled. In terms of policy actions, most respondents highlighted mitigation measures as opposed to local-scale adaptation. Younger participants prioritised actions associated with reducing carbon emissions, whereas older age groups prioritised improving coastal defences. Successful adaptation to the impacts of climate change requires public engagement and support for policy decisions, and the use of different approaches to take account of differences among demographic groups and nationalities

    Tree-ring reconstructed summer temperature anomalies for temperate East Asia since 800 C.E.

    Get PDF
    We develop a summer temperature reconstruction for temperate East Asia based on a network of annual tree-ring chronologies covering the period 800–1989 C.E. The East Asia reconstruction is the regional average of 585 individual grid point summer temperature reconstructions produced using an ensemble version of point-by-point regression. Statistical calibration and validation tests indicate that the regional average possesses sufficient overall skill to allow it to be used to study the causes of temperature variability and change over the region. The reconstruction suggests a moderately warm early medieval epoch (ca. 850–1050 C.E.), followed by generally cooler ‘Little Ice Age’ conditions (ca. 1350–1880 C.E.) and 20th century warming up to the present time. Since 1990, average temperature has exceeded past warm epochs of comparable duration, but it is not statistically unprecedented. Superposed epoch analysis reveals a volcanic forcing signal in the East Asia summer temperature reconstruction, resulting in pulses of cooler summer conditions that may persist for several years. Substantial uncertainties remain, however, particularly at lower frequencies, thus requiring caution and scientific prudence in the interpretation of this record

    Anthranilic Acid: A Versatile Monomer for the Design of Functional Conducting Polymer Composites

    Get PDF
    Polyaniline has been utilized in various applications, yet its widespread adoption has often been impeded by challenges. Composite systems have been proposed as a means of mitigating some of these limitations, and anthranilic acid (2-aminobenzoic acid) has emerged as a possible moderator for use in co-polymer systems. It offers improved solubility and retention of electroactivity in neutral and alkaline media, and, significantly, it can also bestow chemical functionality through its carboxylic acid substituent, which can greatly ease post-polymer modification. The benefits of using anthranilic acid (as a homopolymer or copolymer) have been demonstrated in applications including corrosion protection, memory devices, photovoltaics, and biosensors. Moreover, this polymer has been used as a versatile framework for the sequestration of metal ions for water treatment, and, critically, these same mechanisms serve as a facile route for the production of catalytic metallic nanoparticles. However, the widespread adoption of polyanthranilic acid has been limited, and the aim of the present narrative review is to revisit the early promise of anthranilic acid and assess its potential future use within modern smart materials. A critical evaluation of its properties is presented, and its versatility as both a monomer and a polymer across a spectrum of applications is highlighted

    Interplay between ferromagnetism, surface states, and quantum corrections in a magnetically doped topological insulator

    Full text link
    The breaking of time-reversal symmetry by ferromagnetism is predicted to yield profound changes to the electronic surface states of a topological insulator. Here, we report on a concerted set of structural, magnetic, electrical and spectroscopic measurements of \MBS thin films wherein photoemission and x-ray magnetic circular dichroism studies have recently shown surface ferromagnetism in the temperature range 15 K ≀T≀100\leq T \leq 100 K, accompanied by a suppressed density of surface states at the Dirac point. Secondary ion mass spectroscopy and scanning tunneling microscopy reveal an inhomogeneous distribution of Mn atoms, with a tendency to segregate towards the sample surface. Magnetometry and anisotropic magnetoresistance measurements are insensitive to the high temperature ferromagnetism seen in surface studies, revealing instead a low temperature ferromagnetic phase at Tâ‰Č5T \lesssim 5 K. The absence of both a magneto-optical Kerr effect and anomalous Hall effect suggests that this low temperature ferromagnetism is unlikely to be a homogeneous bulk phase but likely originates in nanoscale near-surface regions of the bulk where magnetic atoms segregate during sample growth. Although the samples are not ideal, with both bulk and surface contributions to electron transport, we measure a magnetoconductance whose behavior is qualitatively consistent with predictions that the opening of a gap in the Dirac spectrum drives quantum corrections to the conductance in topological insulators from the symplectic to the orthogonal class.Comment: To appear in Phys. Rev.

    The impact of routine open nonsuction drainage on fluid accumulation after thyroid surgery: a prospective randomised clinical trial.

    Get PDF
    Background: Thyroid drains following thyroid surgery are routinely used despite minimal supportive evidence. Our aim in this study is to determine the impact of routine open drainage of the thyroid bed postoperatively on ultrasound-determined fluid accumulation at 24 hours. Methods: We conducted a prospective randomised clinical trial on patients undergoing thyroid surgery. Patients were randomly assigned to a drain group (n = 49) or a no-drain group (n = 44) immediately prior to wound closure. Patients underwent a neck ultrasound on day 1 and day 2 postoperatively. After surgery, we evaluated visual analogue scale pain scores, postoperative analgesic requirements, self-reported scar satisfaction at 6 weeks and complications. Results: There was significantly less mean fluid accumulated in the drain group on both day 1, 16.4 versus 25.1 ml (P-value = 0.005), and day 2, 18.4 versus 25.7 ml (P-value = 0.026), following surgery. We found no significant differences between the groups with regard to length of stay, scar satisfaction, visual analogue scale pain score and analgesic requirements. There were four versus one wound infections in the drain versus no-drain groups. This finding was not statistically significant (P = 0.154). No life-threatening bleeds occurred in either group. Conclusions: Fluid accumulation after thyroid surgery was significantly lessened by drainage. However, this study did not show any clinical benefit associated with this finding in the non-emergent setting. Drains themselves showed a trend indicating that they may augment infection rates. The results of this study suggest that the frequency of acute life-threatening bleeds remains extremely low following abandoning drains. We advocate abandoning routine use of thyroid drains. Trial registration: ISRCTN94715414

    CD248+ stromal cells are associated with progressive chronic kidney disease

    Get PDF
    Stromal fibroblasts are the primary cells of the kidney that produce fibrotic matrix. CD248 is a stromal marker expressed on fibroblasts and pericytes within the human kidney. Here, we tested whether CD248 expression in the kidney colocalizes with fibrosis and if it is associated with known determinants of chronic kidney disease (CKD). CD248 expression was located and quantified in situ by immunohistochemistry in kidney biopsies from 93 patients with IgA nephropathy and compared with 22 archived biopsies encompassing normal kidney tissue as control. In normal kidney tissue, CD248 was expressed by resident pericytes, stromal fibroblasts, and was upregulated in human CKD. The expression was linked to known determinants of renal progression. This relationship was maintained in a multivariate analysis with CD248 expression linked to renal survival. CD248 was expressed by a population of α-smooth muscle actin (SMA)+ myofibroblasts and α-SMA− stromal cells but not expressed on CD45+ leukocytes. Thus, CD248 defines a subset of stromal cells, including but not limited to some myofibroblasts, linked to albuminuria and tubulointerstitial damage during tissue remodeling in CKD
    • 

    corecore