127 research outputs found

    Mass Loss of Glaciers and Ice Caps Across Greenland Since the Little Ice Age

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    Abstract Glaciers and ice caps (GICs) are important contributors of meltwater runoff and to global sea level rise. However, knowledge of GIC mass changes is largely restricted to the last few decades. Here we show the extent of 5327 Greenland GICs during Little Ice Age (LIA) termination (1900) and reveal that they have fragmented into 5467 glaciers in 2001, losing at least 587 km3 from their ablation areas, equating to 499 Gt at a rate of 4.34 Gt yr‚ąí1. We estimate that the long-term mean mass balance in glacier ablation areas has been at least ‚ąí0.18 to ‚ąí0.22 m w.e. yr‚ąí1 and note the rate between 2000 and 2019 has been three times that. Glaciers with ice-marginal lakes formed since the LIA termination have had the fastest changing mass balance. Considerable spatial variability in glacier changes suggest compounding regional and local factors present challenges for understanding glacier evolution. Key Points Total volume loss of at least 587 km3 since the Little Ice Age (LIA) termination, equating to 499 Gt and to 1.38 mm sea level equivalent Glacier mass balance from 2000 to 2019 is three times more negative than since the LIA but five times more negative in the North region Lake-terminating glaciers have experienced the greatest change in rate of mass loss Plain Language Summary Glaciers and ice caps of Greenland peripheral to the ice sheet are important contributors of meltwater to the oceans and to global sea-level rise. In this study we map the extent of 5467 glaciers during the Little Ice Age (LIA) termination c. 1900 and calculate that they have lost at least 587 km3. The rate of mass change of these glaciers between 2000 and 2019 was three times more negative than the long-term average (of 4.34 Gt yr‚ąí1) since the LIA. Lake-terminating glaciers now lose mass the fastest compared with land- or marine-terminating glaciers. Considerable spatial variability in glacier responses suggests local factors are important and makes glacier evolution complex

    The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

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    Aim The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. Methods This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. Results Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. Conclusion One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease.Scientific Assessment and Innovation in Neurosurgical Treatment Strategie

    The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

    No full text
    Aim The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. Methods This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. Results Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. Conclusion One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

    A Review of Ferroalloy Tapping Models

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    Tapping is an important furnace operation in the ferroalloy industry and poses a number of complex and coupled challenges of both practical and economical importance. Owing to the hazardous high-temperature conditions surrounding the tap hole, the application of various modeling techniques allows for development and acquisition of both scientific and engineering knowledge of the process through physical or numerical proxies. In this review, earlier work on modeling of ferroalloy tapping is summarized and main principles of the tapping process and multiphase interaction of slag and metal are discussed and summarized. The main focus is on drainage of slag and alloys, but some attention will also be given to metal loss, metal overflow and health, safety and environment. Our review shows that although considerable progress has been made in computational capability over the last decades, However, it is clear that research and development in the field of ferroalloy furnace tapping remains at a relatively nascent stage. The most progress up to date has happened in the area of so called reduced-order models. Such models are robust and simple, and may be easily fitted to process data from a particular operation in order to develop tailored solutions. Such models are more easily combined with software and instruments, ultimately enabling improved automation, process control and ultimately improved tapping consistency

    Tissue-specific contribution of macrophages to wound healing

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    AbstractMacrophages are present in all tissues, either as resident cells or monocyte-derived cells that infiltrate into tissues. The tissue site largely determines the phenotype of tissue-resident cells, which help to maintain tissue homeostasis and act as sentinels of injury. Both tissue resident and recruited macrophages make a substantial contribution to wound healing following injury. In this review, we evaluate how macrophages in two fundamentally distinct tissues, i.e. the lung and the skin, differentially contribute to the process of wound healing. We highlight the commonalities of macrophage functions during repair and contrast them with distinct, tissue-specific functions that macrophages fulfill during the different stages of wound healing

    Multi-messenger Observations of a Binary Neutron Star Merger