111 research outputs found
Climate change, site formation, and indigenous use of coastlines in Barbuda
This article explores the landscape dynamics at the island of Barbuda in the context of changing climate to understand (1) the environmental setting of indigenous settlements; (2) the impacts of current coastal processes; and (3) the potential threats moving forward toward increasing pressure of climate change. Focusing on the site of Seaview, on the east coast of Barbuda, we use geoarchaeological methods to reconstruct the ancient geomorphological setting, investigate changes post-abandonment, and identify the hazards faced under future sea-level projections. Our study shows that (1) sea level stabilization after the Mid-Holocene allowed the formation of coral reefs, seagrass beds and other benthic ecosystems that allowed for biogenic sediment accumulation and growth of sand dune retention ridges. (2) These environmental characteristics, including rich marine food sources, supported the establishment and flourishing of Seaview starting ca. 160 BC. (3) Occupation ended at some point between AD960 and 1000. This change coincided with a period of increased storminess, higher SSTs, and possible coral reef mortality that affected both food availability and sediment supply. (4) Lack of sediments triggered progressive sand dune erosion that continues today and has left the sand dune ridge past the tipping point of erosion. (5) Looking into a future of rapidly changing climate, sea level rise poses a severe and devastating threat to the land- and seascapes of Barbuda. With the lowland coastal plain at or only slightly above current sea level, a rate of SLR comparable to Mid-Holocene rates, and rapid loss of sand dune ridges and coral reefs as natural barriers, it is just a matter of time before the lowlands become transformed beyond recognition. The results of this analysis can be used to improve long-term management of the heritage resources of Barbudans and shed light on parallel challenges experienced on other tropical coastal locations
From icon of empire to national emblem: new evidence for the fallow deer of Barbuda
Barbuda and Antigua's national animal is the fallow deer, Dama dama dama, a species native to the eastern Mediterranean that has been transported around the world by people during the last 8,000 years. The timing and circumstances by which fallow deer came to be established on Barbuda are currently uncertain but, by examining documentary, osteological and genetic evidence, this paper will consider the validity of existing theories. It will review the dynamics of human-Dama relationships from the 1500s AD to the present day and consider how the meaning attached to this species has changed through time: from a symbol of colonial authority and dominance, to a 'walking larder' after the slave emancipation of 1834, and now an important part of the island's economy and cultural heritage that requires careful management
Disequilibrium, adaptation and the Norse settlement of Greenland
This research was supported by the University of Edinburgh ExEDE Doctoral Training Studentship and NSF grant numbers 1202692 and 1140106.There is increasing evidence to suggest that arctic cultures and ecosystems have followed non-linear responses to climate change. Norse Scandinavian farmers introduced agriculture to sub-arctic Greenland in the late tenth century, creating synanthropic landscapes and utilising seasonally abundant marine and terrestrial resources. Using a niche-construction framework and data from recent survey work, studies of diet, and regional-scale climate proxies we examine the potential mismatch between this imported agricultural niche and the constraints of the environment from the tenth to the fifteenth centuries. We argue that landscape modification conformed the Norse to a Scandinavian style of agriculture throughout settlement, structuring and limiting the efficacy of seasonal hunting strategies. Recent climate data provide evidence of sustained cooling from the mid thirteenth century and climate variation from the early fifteenth century. Archaeological evidence suggests that the Norse made incremental adjustments to the changing sub-arctic environment, but were limited by cultural adaptations made in past environments.Publisher PDFPeer reviewe
Effect of the COVID-19 pandemic on surgery for indeterminate thyroid nodules (THYCOVID): a retrospective, international, multicentre, cross-sectional study
Background Since its outbreak in early 2020, the COVID-19 pandemic has diverted resources from non-urgent and elective procedures, leading to diagnosis and treatment delays, with an increased number of neoplasms at advanced stages worldwide. The aims of this study were to quantify the reduction in surgical activity for indeterminate thyroid nodules during the COVID-19 pandemic; and to evaluate whether delays in surgery led to an increased occurrence of aggressive tumours.Methods In this retrospective, international, cross-sectional study, centres were invited to participate in June 22, 2022; each centre joining the study was asked to provide data from medical records on all surgical thyroidectomies consecutively performed from Jan 1, 2019, to Dec 31, 2021. Patients with indeterminate thyroid nodules were divided into three groups according to when they underwent surgery: from Jan 1, 2019, to Feb 29, 2020 (global prepandemic phase), from March 1, 2020, to May 31, 2021 (pandemic escalation phase), and from June 1 to Dec 31, 2021 (pandemic decrease phase). The main outcomes were, for each phase, the number of surgeries for indeterminate thyroid nodules, and in patients with a postoperative diagnosis of thyroid cancers, the occurrence of tumours larger than 10 mm, extrathyroidal extension, lymph node metastases, vascular invasion, distant metastases, and tumours at high risk of structural disease recurrence. Univariate analysis was used to compare the probability of aggressive thyroid features between the first and third study phases. The study was registered on ClinicalTrials.gov, NCT05178186.Findings Data from 157 centres (n=49 countries) on 87 467 patients who underwent surgery for benign and malignant thyroid disease were collected, of whom 22 974 patients (18 052 [78 center dot 6%] female patients and 4922 [21 center dot 4%] male patients) received surgery for indeterminate thyroid nodules. We observed a significant reduction in surgery for indeterminate thyroid nodules during the pandemic escalation phase (median monthly surgeries per centre, 1 center dot 4 [IQR 0 center dot 6-3 center dot 4]) compared with the prepandemic phase (2 center dot 0 [0 center dot 9-3 center dot 7]; p<0 center dot 0001) and pandemic decrease phase (2 center dot 3 [1 center dot 0-5 center dot 0]; p<0 center dot 0001). Compared with the prepandemic phase, in the pandemic decrease phase we observed an increased occurrence of thyroid tumours larger than 10 mm (2554 [69 center dot 0%] of 3704 vs 1515 [71 center dot 5%] of 2119; OR 1 center dot 1 [95% CI 1 center dot 0-1 center dot 3]; p=0 center dot 042), lymph node metastases (343 [9 center dot 3%] vs 264 [12 center dot 5%]; OR 1 center dot 4 [1 center dot 2-1 center dot 7]; p=0 center dot 0001), and tumours at high risk of structural disease recurrence (203 [5 center dot 7%] of 3584 vs 155 [7 center dot 7%] of 2006; OR 1 center dot 4 [1 center dot 1-1 center dot 7]; p=0 center dot 0039).Interpretation Our study suggests that the reduction in surgical activity for indeterminate thyroid nodules during the COVID-19 pandemic period could have led to an increased occurrence of aggressive thyroid tumours. However, other compelling hypotheses, including increased selection of patients with aggressive malignancies during this period, should be considered. We suggest that surgery for indeterminate thyroid nodules should no longer be postponed even in future instances of pandemic escalation.Funding None.Copyright (c) 2023 Published by Elsevier Ltd. All rights reserved
A global review and meta-analysis of applications of the freshwater Fish Invasiveness Screening Kit
The freshwater Fish Invasiveness Screening Kit (FISK) has been applied in 35 risk assessment areas in 45 countries across the six inhabited continents (11 applications using FISK v1; 25 using FISK v2). The present study aimed: to assess the breadth of FISK applications and the confidence (certainty) levels associated with the decision-support tool’s 49 questions and its ability to distinguish between taxa of low-to-medium and high risk of becoming invasive, and thus provide climate-specific, generalised, calibrated thresholds for risk level categorisation; and to identify the most potentially invasive freshwater fish species on a global level. The 1973 risk assessments were carried out by 70 + experts on 372 taxa (47 of the 51 species listed as invasive in the Global Invasive Species Database www.iucngisd.org/gisd/), which in decreasing order of importance belonged to the taxonomic Orders Cypriniformes, Perciformes, Siluriformes, Characiformes, Salmoniformes, Cyprinodontiformes, with the remaining ≈ 8% of taxa distributed across an additional 13 orders. The most widely-screened species (in decreasing importance) were: grass carp Ctenopharyngodon idella, common carp Cyprinus carpio, rainbow trout Oncorhynchus mykiss, silver carp Hypophthalmichthys molitrix and topmouth gudgeon Pseudorasbora parva. Nine ‘globally’ high risk species were identified: common carp, black bullhead Ameiurus melas, round goby Neogobius melanostomus, Chinese (Amur) sleeper Perccottus glenii, brown bullhead Ameiurus nebulosus, eastern mosquitofish Gambusia holbrooki, largemouth (black) bass Micropterus salmoides, pumpkinseed Lepomis gibbosus and pikeperch Sander lucioperca. The relevance of this global review to policy, legislation, and risk assessment and management procedures is discussed
CRAYFISH EPIBIONTS BRANCHIOBDELLA SP. AND HYSTRICOSOMA CHAPPUISI (ANNELIDA: CLITELLATA) IN GREECE
Specimens of the three known Greek crayfish species, Astacus astacus (Linnaeus, 1758), Astacus leptodactylus Eschscholtz, 1823 and Austropotamobius torrentium (Schrank, 1803), were collected from seven localities in Greece and were examined for the epibionts of Branchiobdella sp. (Annelida: Clitellata) and the aelosomatid Hystricosoma chappuisi Michaelsen, 1926 and the copepod Nitocrella divaricata (Chappuis, 1923). As a result, three branchiobdellid species, Branchiobdella parasita (Braun, 1805), Branchiobdella pentodonta Whitman, 1882 and Branchiobdella hexodonta Grüber, 1883 were found. This was also the first report of B. pentodonta from Greece as well as H. chappuisi, the latter being found on crayfish gills in one of the localities investigated. Moreover, the current work represents the first documentation of the presence of B. parasita and B. hexodonta in several localities in Greece
Freshwater crayfish distribution update and maps for Greece: Combining literature and citizen-science data
Crayfish are charismatic creatures of high interest to humans, among others playing key roles in freshwater ecosystems. Considering the significance of indigenous crayfish species (ICS) as well as the risks posed by non-indigenous crayfish species (NICS) that may dissemite a crayfish plague pathogen Aphanomyces astaci, astacological research has advanced particularly in Europe. In this context, crayfish distribution patterns are of fundamental importance. Focused on all crayfish established in the Greek wild, we provide an updated distribution and maps, combining extensive review of existing literature as well as newly emerging sources, largely represented by increasingly important citizen-science data. Obtained results demonstrate that ICS, mainly the Astacus astacus and Austropotamobius torrentium, remain relatively well settled in the country. The last ICS, Astacus leptodactylus, was translocated in few places outside its native range, leading to the formation of new flourishing populations and at least in one case it sustains commercial exploitation. Concerning NICS, a single population of Pacifastacus leniusculus is also established in the artificial lake Agra (Region of Central Macedonia) and keeps spreading. Unfortunately, there are only few methods under a very narrow range of conditions making successful eradication of unwanted NICS populations feasible. This option is even more difficult as this population is commercially exploited and traded. Since further potentially problematic NICS are also pet-traded in the country, educating public and communicating highlighted issues are the most effective ways limiting their releases and consecutive establishment in the wild. © 2017 C. Perdikaris
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