Ice advance-retreat sediment successions along the Logata River, Taymyr Peninsula, Arctic Siberia

A number of sites were investigated in river sections along the Logata River on the Taymyr Peninsula, Russia, and its adjacent areas to shed more light on the glaciation history over the last glacial cycles. The sediments exposed at the investigated sites are correlated and put into a local stratigraphic scheme divided into five main units. Unit 1 is positioned lowest in the stratigraphy and consists of greyish yellow sand with gravel horizons made up of shale. The poor exposure of the unit obstructs any attempt to interpret the depositional environment of the unit. Unit 2 is a matrix-supported silty clayey diamicton with glaciotectonic lamination and sand boudins; it is interpreted as a subglacial traction till deposited from NE. Unit 3 consists of intercalated massive and laminated beds of silt and clay with a varying abundance of marine molluscs and drop clasts (IRD). The unit is interpreted as deposited in an off-shore glaciomarine depositional environment. Unit 4 is made up of sorted sediments, primarily sand, but also coarser and finer sediments. Organic detritus is common in the unit. Unit 4 is interpreted as a fluvial depositional environment of a meandering river. Unit 5 is the uppermost unit in the local stratigraphic scheme and contains properties typical of so called ice complex deposits; it consists of sorted sediments of silt and sand with peat inclusions and an abundance of ground ice. Organic detritus and mega fauna fossils are common in the unit. The sites examined in detail were sampled for radiocarbon, OSL and ESR dating. All radiocarbon datings (13) on mollusc shells and organic macro remains yield infinite ages, while the results from the ESR and OSL datings are still pending. All units together suggest a full glacial-deglaciation cycle with a Kara Sea ice sheet advancing and retreating within a marine basin, and with an isostatically driven regression thereafter, ending with a terrestrial environment. The most probable timing is the Early Weichselian (100-80 kyr BP).Ett antal flodskärningar undersöktes längs Logatafloden och dess omkringliggande områden för att ge en ökad förståelse om de senaste istiderna för denna del av världen. De påträffade sedimenten vittnade om en marin miljö efter en isframstöt och därefter en landhöjning som ledde till dagens flod- och tundralandskap. Det finns många teorier angående hur utbredd inlandsisen var över arktiska Sibirien under Weichselistiden (ca 115 000 – 11 700 år sedan). Detta gäller särskilt den senare delen av istiden där vissa teorier förespråkar ett gigantiskt istäcke över större delen av Arktis, medan andra föreslår ett mycket mindre istäcke, framförallt över Sibirien. En internationell forskningsexpedition tillbringade närmare två månader på Tajmyrhalvön i Ryssland under sommaren 2012. En del av denna tid spenderades längs Logatafloden söder om Byrrangabergen där ett flertal flodskärningar undersöktes. En mängd prover togs för att kunna åldersbestämma sedimenten från flodskärningarna, varav bara AMS 14C-dateringarna, dvs. datering av organiskt material, användes i den här uppsatsen. Sedimenten från flodskärningarna vittnade om ett landskap som en gång var täckt av en inlandsis och som därefter översvämmades av havsvatten när isen drog sig tillbaka. Den efterföljande landhöjningen gjorde att den marina miljön övergick till det flod- och tundralanskap som går att se idag. De marina sedimenten innehöll en fauna som trivs i arktiskt vatten, medan de yngre sedimenten innehöll fossil av megafauna, såsom mammut. Samtliga dateringar var äldre än maxåldern för dateringsmetoden, dvs. >45 000 år. Detta innebär att inlandsisen antagligen härstammar från början av Weichselistiden, ca 100 000 – 80 000 år sedan. Dessa fynd bestrider att Tajmyrhalvön ska ha varit täckt av ett gigantiskt istäcke under slutet av denna istid, ca 20 000 år sedan

Aeolian activity in Sweden: an unexplored environmental archive

During the course of this three-year project, we have studied aeolian deposits at 70 sites within sixteen areas in south-central Sweden. Inland dunes have been the focus, but some sites with coversand and coastal dunes have also been investigated. We have mapped dune morphology, mainly by LiDAR-based remote sensing, studied the internal sediment architecture by ground-penetrating radar profiling and in sediment exposures, documented the sedimentology of the deposits with field and laboratory methods as well as determined the age of the deposits with luminescence and radiocarbon dating. In this scientific report to the Geological Survey of Sweden, who funded the project, we present a summary of the project and its results. The largest and best developed dune fields are found at glacifluvial deposits in Värmland and Dalarna, while in areas south thereof there are mainly scattered dunes or coversand deposits. A range of dune types has been observed, but transverse dunes seem to be dominating and the majority of these are oriented roughly NE-SW. The bulk of the aeolian deposits were formed shortly after the local deglaciation and, once stabilised, do not appear to have been significantly reworked during the Holocene. Most Mid- and Late-Holocene aeolian deposits consist of coversand, apart from in coastal areas where e.g. young foredunes are found.Our results thus largely confirm the hypothesis of previous investigators but we do add a significant amount of new information. We provide, for the first time for most of our study areas, numerical ages for the aeolian deposits and thus provide the timing and duration of sand-drift events in south-central Sweden. The ages, in combination with detailed geomorphological mapping, allow us to distinguish phases of dune-field development, which are likely due to changes in wind patterns and vegetation cover, and also to correlate Swedish aeolian deposits to regional storminess periods. Based on sedimentological information we are able to reconstruct dominating depositional processes, transport paths and sediment sources. Additional outcomes of the project are e.g. methodological developments (LiDAR mapping, luminescence dating) and pilot studies of potential relevance for applied geology (coastal development)

A sedimentary model for transverse inland dunes in central Scandinavia

The largest dune fields in Sweden and Norway are small in international comparison but still form distinct parts of this previously glaciated landscape. The dunes formed c.10.5-9 ka ago, shortly after the last deglaciation, when winds close to the ice sheet were strong and vegetation was largely absent [1-4]. Since then they have been more or less stable and today they are covered by forest. Most of the dunes are curvi-linear in shape and formed transverse to the wind [5]. Here we present a sedimentary model for these transverse inland dunes, based on geophysical and sedimentological investigations of dunes at Skattungheden, Bonäsheden and Starmoen in central Sweden and south-eastern Norway. Ground-penetrating radar profiles reveal the main architectural elements of the dunes, while logging of sediment exposures in the dunes provide information on sedimentary structures. Grain-size analysis and scanning electron microscope studies of individual grains give us more detail on sediment characteristics.The main dune body, consisting of cross beds generally dipping 25-30°, makes up the largest part of the dunes; minor elements include windward side cover, dune-crest superimposed features and dune-toe apron (Fig. 1). The dominating sediment structures are planar parallel lamination, massive to vaguely stratified beds and a few types of secondary structures, such as bioturbation or physical disturbances. Few large erosional discordances are seen, and the dominating depositional processes are wind-ripple migration and some grain fall on the sloping lee sides. The sediments are well-sorted fine-to-medium sand, dominated by quartz, but with significant amounts of feldspar as well as some lithic fragments, micas and heavy minerals. Most grains are angular to subrounded and their surfaces display few traces of aeolian transport. Overall, the dune sands show large similarities to their source material (glacifluvial deposits), which suggests only short transport and brief reworking by aeolian processes.References[1] Alexanderson, H. and M. Bernhardson, OSL dating and luminescence characteristics of aeolian deposits and their source material in Dalarna, central Sweden Boreas, 2016. 45: p. 876-893.[2] Alexanderson, H. and M. Henriksen, A short-lived aeolian event during the Early Holocene in southeastern Norway. Quaternary Geochronology, 2015. 30: p. 175-180.[3] Bernhardson, M. and H. Alexanderson, Early Holocene NW-W winds reconstructed from small dune fields, central Sweden. Boreas, 2018.[4] Alexanderson, H. and D. Fabel, Holocene chronology of the Brattforsheden delta and inland dune field, SW Sweden. Geochronometria, 2015. 42: p. 1-16.[5] Bernhardson, M. and H. Alexanderson, Early Holocene dune field development in Dalarna, central Sweden: A geomorphological and geophysical case study. Earth Surface Processes and Landforms, 2017. 42: p. 1847-1859

Early symptoms and sensations as predictors of lung cancer: a machine learning multivariate model.

The aim of this study was to identify a combination of early predictive symptoms/sensations attributable to primary lung cancer (LC). An interactive e-questionnaire comprised of pre-diagnostic descriptors of first symptoms/sensations was administered to patients referred for suspected LC. Respondents were included in the present analysis only if they later received a primary LC diagnosis or had no cancer; and inclusion of each descriptor required ≥4 observations. Fully-completed data from 506/670 individuals later diagnosed with primary LC (n = 311) or no cancer (n = 195) were modelled with orthogonal projections to latent structures (OPLS). After analysing 145/285 descriptors, meeting inclusion criteria, through randomised seven-fold cross-validation (six-fold training set: n = 433; test set: n = 73), 63 provided best LC prediction. The most-significant LC-positive descriptors included a cough that varied over the day, back pain/aches/discomfort, early satiety, appetite loss, and having less strength. Upon combining the descriptors with the background variables current smoking, a cold/flu or pneumonia within the past two years, female sex, older age, a history of COPD (positive LC-association); antibiotics within the past two years, and a history of pneumonia (negative LC-association); the resulting 70-variable model had accurate cross-validated test set performance: area under the ROC curve = 0.767 (descriptors only: 0.736/background predictors only: 0.652), sensitivity = 84.8% (73.9/76.1%, respectively), specificity = 55.6% (66.7/51.9%, respectively). In conclusion, accurate prediction of LC was found through 63 early symptoms/sensations and seven background factors. Further research and precision in this model may lead to a tool for referral and LC diagnostic decision-making

It is important that the process goes quickly, isn't it?” A qualitative multi-country study of colorectal or lung cancer patients’ narratives of the timeliness of diagnosis and quality of care

Purpose: The emphasis on early diagnosis to improve cancer survival has been a key factor in the development of cancer pathways across Europe. The aim of this analysis was to explore how the emphasis on early diagnosis and timely treatment is reflected in patient's accounts of care, from the first suspicion of colorectal or lung cancer to their treatment in Denmark, England and Sweden. Method: We recruited 155 patients in Denmark, England and Sweden who were within six months of being diagnosed with lung or colorectal cancer. Data were collected via semi-structured narrative interviews and analysed using a thematic approach. Results: Participants’ accounts of quality of care were closely related to how quickly (or not) diagnosis, treatment and/or healthcare processes went. Kinetic metaphors as a description of care (such as treadmill) could be interpreted positively as participants were willing to forgo some degree of control and accept disruption to their lives to ensure more timely care. Drawing on wider cultural expectations of the benefits of diagnosing and treating cancer quickly, some participants were concerned that the waiting times between interventions might allow time for the cancer to grow. Conclusions: Initiatives emphasising the timeliness of diagnosis and treatment are reflected in the ways some patients experience their care. However, these accounts were open to further contextualisation about what speed of healthcare processes meant for evaluating the quality of their care. Healthcare professionals could therefore be an important patient resource in providing reassurance and support about the timeliness of diagnosis or treatment

A longitudinal study of changing characteristics of self-reported taste and smell alterations in patients treated for lung cancer

AbstractPurposeTaste and smell alterations (TSAs) are common symptoms in patients with cancer that may interfere with nutritional intake and quality of life. In this study, we explore and describe how characteristics of self-reported TSAs change in individuals with lung cancer over time using a multiple case study approach to present longitudinal data from individuals.MethodsPatients under investigation for lung cancer were recruited from one university hospital in Sweden. The 52 patients providing data eligible for the analyses presented here were those treated for primary lung cancer with three measurement time-points, of which one was prior to treatment and two after treatment start. Four self-report instruments were used for data collection. These included the Taste and Smell Survey, used to characterize TSAs for each individual at the three time-points and instruments measuring nutritional status, symptom burden and well-being. Three patient cases are described in detail to illustrate variation in individual experiences of TSAs.ResultsThe characteristics of the TSAs experienced changed over time for many of the individuals in this study, including those undergoing surgery or stereotactic radiotherapy. The case descriptions show how the individual experiences of TSAs and the impact on daily life of these symptoms not only depend on TSA characteristics, but may be influenced by contextual factors, e.g. other symptoms and life situation.ConclusionsOur results suggest that healthcare professionals need to consider the variation in characteristics of TSAs among and within patients over time, and be attentive to individual experiences of TSAs

Patients' initial steps to cancer diagnosis in Denmark, England and Sweden: what can a qualitative, cross-country comparison of narrative interviews tell us about potentially modifiable factors?

OBJECTIVES: To illuminate patterns observed in International Cancer Benchmarking Programme studies by extending understanding of the various influences on presentation and referral with cancer symptoms. DESIGN: Cross-country comparison of Denmark, England and Sweden with qualitative analysis of in-depth interview accounts of the prediagnostic process in lung or bowel cancer. PARTICIPANTS: 155 women and men, aged between 35 and 86 years old, diagnosed with lung or bowel cancer in 6 months before interview. SETTING: Participants recruited through primary and secondary care, social media and word of mouth. Interviews collected by social scientists or nurse researchers during 2015, mainly in participants' homes. RESULTS: Participants reported difficulties in interpreting diffuse bodily sensations and symptoms and deciding when to consult. There were examples of swift referrals by primary care professionals in all three countries. In all countries, participants described difficulty deciding if and when to consult, highlighting concerns about access to general practitioner appointments and overstretched primary care services, although this appears less prominent in the Swedish data. It was not unusual for there to be more than one consultation before referral and we noted two distinct patterns of repeated consultation: (1) situations where the participant left the primary care consultation with a plan of action about what should happen next; (2) participants were unclear about under which conditions to return to the doctors. This second pattern sometimes extended over many weeks during which patients described uncertainty, and sometimes frustration, about if and when they should return and whether there were any other feasible investigations. The latter pattern appeared more evident in the interviews in England and Denmark than Sweden. CONCLUSION: We suggest that if clear action plans, as part of safety netting, were routinely used in primary care consultations then uncertainty, false reassurance and the inefficiency and distress of multiple consultations could be reduced

Using patients' own knowledge of early sensations and symptoms to develop an interactive, individualized e-questionnaire to facilitate early diagnosis of lung cancer.

BACKGROUND: One reason for the often late diagnosis of lung cancer (LC) may be that potentially-indicative sensations and symptoms are often diffuse, and may not be considered serious or urgent, making their interpretation complicated. However, with only a few exceptions, efforts to use people's own in-depth knowledge about prodromal bodily experiences has been a missing link in efforts to facilitate early LC diagnosis. In this study, we describe and discuss facilitators and challenges in our process of developing and initial testing an interactive, self-completion e-questionnaire based on patient descriptions of experienced prodromal sensations and symptoms, to support early identification of lung cancer (LC). METHODS: E-questionnaire items were derived from in-depth, detailed explorative interviews with individuals undergoing investigation for suspected LC. The descriptors of sensations/symptoms and the background items obtained were the basis for developing an interactive, individualized instrument, PEX-LC, which was refined for usability through think-aloud and other interviews with patients, members of the public, and clinical staff. RESULTS: Major challenges in the process of developing PEX-LC related to collaboration among many actors, and design/user interface problems including technical issues. Most problems identified through the think-aloud interviews related to design/user interface problems and technical issues rather than content, for example we re-ordered questions to be in line with patients' chronological, rather than retrospective, descriptions of their experiences. PEX-LC was developed into a final e-questionnaire on a touch-screen smart tablet with one background module covering sociodemographic characteristics, 10 interactive, individualized modules covering early sensations and symptoms, and a 12th assessing current symptoms. CONCLUSIONS: Close collaboration with patients throughout the process was intrinsic for developing PEX-LC. Similarly, we recognized the extent to which clinicians and technical experts were also important in this process. Similar endeavors should assure all necessary competence is included in the core research team, to facilitate timely progress. Our experiences developing PEX-LC combined with new empirical research suggest that this individualized, interactive e-questionnaire, developed through systematizing patients' own formulations of their prodromal symptom experiences, is both feasible for use and has potential value in the intended group

Sensations, symptoms, and then what? Early bodily experiences prior to diagnosis of lung cancer

Lung cancer (LC) generally lacks unique core symptoms or signs. However, there are a multitude of bodily sensations that are often non-specific, not easily understood, and many times initially not recognized as indicative of LC by the affected person, which often leads to late diagnosis. In this international qualitative study, we inductively analyzed retrospective accounts of 61 people diagnosed with LC in Denmark, England and Sweden. Using the bodily sensations they most commonly spoke about (tiredness, breathlessness, pain, and cough), we constructed four sensation-based cases to understand the pre-diagnostic processes of reasoning and practice triggered by these key indicators of LC. We thereafter critically applied Hay's model of sensations to symptoms transformation, examining its central concepts of duration, disability and vulnerability, to support understanding of these processes. We found that while duration and disability are clearly relevant, vulnerability is more implicitly expressed in relation to perceived threat. Tiredness, even when of long duration and causing disability, was often related to normal aging, rather than a health threat. Regardless of duration, breathlessness was disturbing and threatening enough to lead to care-seeking. Pain varied by location, duration and degree of disability, and thus also varied in degree of threat perceived. Preconceived, but unmet expectations of what LC-related cough and pain would entail could cause delays by misleading participants; if cough lasted long enough, it could trigger health care contact. Duration, disability, and sense of threat, rather than vulnerability, were found to be relevant concepts for understanding the trajectory to diagnosis for LC among these participants. The process by which an individual, their family and health care providers legitimize sensations, allowing them to be seen as potential symptoms of disease, is also an essential, but varying part of the diagnostic processes described here

Influence of taste disorders on dietary behaviors in cancer patients under chemotherapy

<p>Abstract</p> <p>Objectives</p> <p>To determine the relationship between energy and nutrient consumption with chemosensory changes in cancer patients under chemotherapy.</p> <p>Methods</p> <p>We carried out a cross-sectional study, enrolling 60 subjects. Cases were defined as patients with cancer diagnosis after their second chemotherapy cycle (n = 30), and controls were subjects without cancer (n = 30). Subjective changes of taste during treatment were assessed. Food consumption habits were obtained with a food frequency questionnaire validated for Mexican population. Five different concentrations of three basic flavors --sweet (sucrose), bitter (urea), and a novel basic taste, umami (sodium glutamate)-- were used to measure detection thresholds and recognition thresholds (RT). We determine differences between energy and nutrient consumption in cases and controls and their association with taste DT and RT.</p> <p>Results</p> <p>No demographic differences were found between groups. Cases showed higher sweet DT (6.4 vs. 4.4 μmol/ml; p = 0.03) and a higher bitter RT (100 vs. 95 μmol/ml; <it>p </it>= 0.04) than controls. Cases with sweet DT above the median showed significant lower daily energy (2,043 vs.1,586 kcal; p = 0.02), proteins (81.4 vs. 54 g/day; <it>p </it>= 0.01), carbohydrates (246 vs.192 g/day; <it>p </it>= 0.05), and zinc consumption (19 vs.11 mg/day; <it>p </it>= 0.01) compared to cases without sweet DT alteration. Cases with sweet DT and RT above median were associated with lower completion of energy requirements and consequent weight loss. There was no association between flavors DT or RT and nutrient ingestion in the control group.</p> <p>Conclusion</p> <p>Changes of sweet DT and bitter RT in cancer patients under chemotherapy treatment were associated with lower energy and nutrient ingestion. Taste detection and recognition thresholds disorders could be important factors in malnutrition development on patients with cancer under chemotherapy treatment.</p