Corrigendum: Widespread movement of meltwater onto and across Antarctic ice shelves.

This corrects the article DOI: 10.1038/nature22049.

Widespread movement of meltwater onto and across Antarctic ice shelves.

Surface meltwater drains across ice sheets, forming melt ponds that can trigger ice-shelf collapse, acceleration of grounded ice flow and increased sea-level rise. Numerical models of the Antarctic Ice Sheet that incorporate meltwater's impact on ice shelves, but ignore the movement of water across the ice surface, predict a metre of global sea-level rise this century in response to atmospheric warming. To understand the impact of water moving across the ice surface a broad quantification of surface meltwater and its drainage is needed. Yet, despite extensive research in Greenland and observations of individual drainage systems in Antarctica, we have little understanding of Antarctic-wide surface hydrology or how it will evolve. Here we show widespread drainage of meltwater across the surface of the ice sheet through surface streams and ponds (hereafter 'surface drainage') as far south as 85° S and as high as 1,300 metres above sea level. Our findings are based on satellite imagery from 1973 onwards and aerial photography from 1947 onwards. Surface drainage has persisted for decades, transporting water up to 120 kilometres from grounded ice onto and across ice shelves, feeding vast melt ponds up to 80 kilometres long. Large-scale surface drainage could deliver water to areas of ice shelves vulnerable to collapse, as melt rates increase this century. While Antarctic surface melt ponds are relatively well documented on some ice shelves, we have discovered that ponds often form part of widespread, large-scale surface drainage systems. In a warming climate, enhanced surface drainage could accelerate future ice-mass loss from Antarctic, potentially via positive feedbacks between the extent of exposed rock, melting and thinning of the ice sheet.

Antarctic ice shelf potentially stabilized by export of meltwater in surface river.

Meltwater stored in ponds and crevasses can weaken and fracture ice shelves, triggering their rapid disintegration. This ice-shelf collapse results in an increased flux of ice from adjacent glaciers and ice streams, thereby raising sea level globally. However, surface rivers forming on ice shelves could potentially export stored meltwater and prevent its destructive effects. Here we present evidence for persistent active drainage networks-interconnected streams, ponds and rivers-on the Nansen Ice Shelf in Antarctica that export a large fraction of the ice shelf's meltwater into the ocean. We find that active drainage has exported water off the ice surface through waterfalls and dolines for more than a century. The surface river terminates in a 130-metre-wide waterfall that can export the entire annual surface melt over the course of seven days. During warmer melt seasons, these drainage networks adapt to changing environmental conditions by remaining active for longer and exporting more water. Similar networks are present on the ice shelf in front of Petermann Glacier, Greenland, but other systems, such as on the Larsen C and Amery Ice Shelves, retain surface water at present. The underlying reasons for export versus retention remain unclear. Nonetheless our results suggest that, in a future warming climate, surface rivers could export melt off the large ice shelves surrounding Antarctica-contrary to present Antarctic ice-sheet models, which assume that meltwater is stored on the ice surface where it triggers ice-shelf disintegration.

Health Status, Persistent Symptoms, and Effort Intolerance One Year After Acute COVID-19 Infection.

BACKGROUND: The long-term prevalence and risk factors for post-acute COVID-19 sequelae (PASC) are not well described and may have important implications for unvaccinated populations and policy makers. OBJECTIVE: To assess health status, persistent symptoms, and effort tolerance approximately 1 year after COVID-19 infection DESIGN: Retrospective observational cohort study using surveys and clinical data PARTICIPANTS: Survey respondents who were survivors of acute COVID-19 infection requiring Emergency Department presentation or hospitalization between March 3 and May 15, 2020. MAIN MEASURE(S): Self-reported health status, persistent symptoms, and effort tolerance KEY RESULTS: The 530 respondents (median time between hospital presentation and survey 332 days [IQR 325-344]) had mean age 59.2±16.3 years, 44.5% were female and 70.8% were non-White. Of these, 41.5% reported worse health compared to a year prior, 44.2% reported persistent symptoms, 36.2% reported limitations in lifting/carrying groceries, 35.5% reported limitations climbing one flight of stairs, 38.1% reported limitations bending/kneeling/stooping, and 22.1% reported limitations walking one block. Even those without high-risk comorbid conditions and those seen only in the Emergency Department (but not hospitalized) experienced significant deterioration in health, persistent symptoms, and limitations in effort tolerance. Women (adjusted relative risk ratio [aRRR] 1.26, 95% CI 1.01-1.56), those requiring mechanical ventilation (aRRR 1.48, 1.02-2.14), and people with HIV (aRRR 1.75, 1.14-2.69) were significantly more likely to report persistent symptoms. Age and other risk factors for more severe COVID-19 illness were not associated with increased risk of PASC. CONCLUSIONS: PASC may be extraordinarily common 1 year after COVID-19, and these symptoms are sufficiently severe to impact the daily exercise tolerance of patients. PASC symptoms are broadly distributed, are not limited to one specific patient group, and appear to be unrelated to age. These data have implications for vaccine hesitant individuals, policy makers, and physicians managing the emerging longer-term yet unknown impact of the COVID-19 pandemic.

Radiative Transfer and Generalized Wind.

Dissimilar flows can be compared by exploiting the fact that all flux densities divided by their conjugate volume densities form velocity fields, which have been described as generalized winds. These winds are an extension of the classical notion of wind in fluids which puts these distinct processes on a common footing, leading to thermodynamical implications. This paper extends this notion from fluids to radiative transfer in the context of a classical two-stream atmosphere, leading to such velocities for radiative energy and entropy. These are shown in this paper to exhibit properties for radiation previously only thought of in terms of fluids, such as the matching of velocity fields where entropy production stops.

Prognostic Implication of Selective Serotonin Reuptake Inhibitors in Osseointegration of Dental Implants: A 5-year Retrospective Study.

AIM: Dental implants are the preferred treatment modality in the present edentulous era. Selective serotonin reuptake inhibitors (SSRIs) have detrimental effect on bone density. The present study was conducted to determine the effect of SSRIs on the success rate of dental implants. MATERIALS AND METHODS: The present study was conducted on 352 patients of both genders with 680 dental implants. History of depression and SSRI medication was retrieved. Patients were divided into two groups. Group I (110 patients, 230 dental implants) patients were on SSRI, while group II (242 patients, 450 dental implants) patients were non-SSRI. In all patients, the implant failure rate was recorded. RESULTS: In group I, 35 patients were >50 years, while 75 were <50 years of age. In group II, 60 patients were >50 years, while 182 were <50 years of age. The difference was significant (p < 0.05). Group I had 45 males and 65 females, while group II comprised of 105 males and 137 females. Group I showed 25 implant failures and group II had 21 implant failures. Age group >50 years showed 12 implant failures while <50 years had 13 in group I compared with 10 in patients >50 years and 11 in patients with <50 years of age; 56% smokers had implant in group I as compared with 60% failure in group II. In group I, 27% diabetic patients had failures as compared with 13.4% in group II. The difference was significant (p < 0.05). Group I showed maximum failures in terms of loosening of screw (8) followed by fracture of implant (7), peri-implantitis (6), and fracture of screw (4), whereas in group II, 7 cases were of loosening of screw, 6 cases were of fracture of screw, 5 cases of fracture of implant, and 3 cases of peri-implantitis. The difference was nonsignificant (p > 0.05). CONCLUSION: Selective serotonin reuptake inhibitors cause increased osteoclastic activity, leading to bone loss and implants placed in patients with history of depression are more prone to failures. CLINICAL SIGNIFICANCE: Failure rates of dental implants are significantly increased in patients taking SSRIs due to depression. Careful case analysis and history of depression may minimize the failure rates.

Glyceraldehyde-3-phosphate dehydrogenase is activated by lysine 254 acetylation in response to glucose signal.

The altered metabolism in most tumor cells consists of elevated glucose uptake and increased glycolysis even in the presence of high oxygen tension. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is an obligatory enzyme in glycolysis. Here, we report that acetylation at lysine 254 (K254) increases GAPDH activity in response to glucose. Furthermore, acetylation of GAPDH (K254) is reversibly regulated by the acetyltransferase PCAF and the deacetylase HDAC5. Substitution of K254 to glutamine compromises the ability of GAPDH to support cell proliferation and tumor growth. Our study reveals a mechanism of GAPDH enzyme activity regulation by acetylation and its critical role in cellular regulation.

Systemic Lupus Erythematosus Presenting as Neuroretinitis.

Neuroretinitis is the inflammation of retina and optic nerve. It is associated with optic disc edema accompanied by peripapillary or macular hard exudates. A 17 yr old female presented with headache and nausea of five days duration. She had periorbital edema and mild splenomegaly. Neurological assessment was non-contributory. She was found to have pancytopenia, albuminuria and a high ESR. Thereafter she developed blurring of vision of both eyes. Opthalmological examination showed it to be due to bilateral neuroretinitis. ANA and anti-ds DNA were strongly positive. Renal biopsy with immunofluorescence study revealed diffuse global proliferative lupus nephritis with active lesions [class IV-G (A)]. She was diagnosed as a case of SLE presenting with neuroretinitis.

Assessment of clinico-immunological profile of newly diagnosed HIV patients presenting to a teaching hospital of eastern India.

BACKGROUND & OBJECTIVES: Newly diagnosed HIV patients may be asymptomatic or present with a wide range of symptoms related to opportunistic infections, acute seroconversion illness or other medical illnesses. This study was designed to evaluate the socio-demographic parameters, spectrum of the presenting clinical conditions and concurrent immunological status of newly diagnosed HIV patients and document the WHO clinical stages at the time of HIV diagnosis. METHODS: This cross-sectional, observational study was undertaken over a 12 month period at a tertiary referral hospital in eastern India. Three hundred sixty consecutive newly diagnosed HIV patients were selected for the study from the HIV clinic and medicine wards of this hospital. Demographic and clinical data and relevant laboratory investigations of the patients were recorded and analyzed. RESULTS: Mean age of patients was 36.38±10.62 yr, while 63.89 per cent were males. The main mode of transmission of HIV for males and females were unprotected exposure to commercial sex (139, 60.44%) and intercourse with HIV seropositive spouses (89, 68.46%), respectively. Fever (104, 28.89%), weight loss (103, 28.61%) and generalized weakness (80, 22.22%) were the predominant symptoms. Overall mean CD4 count was 176.04±163.49 cells/µl (males 142.19±139.33 cells/µl; females 235.92±185.11 cells/µl). Overall, 224 opportunistic infections were documented in 160 patients, opportunistic diarrhoea (44, 12.22%) and pulmonary tuberculosis (39, 10.83%) being the commonest. There were 83 and 133 patients in WHO clinical stages 3 and 4, respectively; 291 (80.83%) patients were eligible for initiation of first-line antiretrovirals at presentation. INTERPRETATION & CONCLUSIONS: Advanced immunodeficiency and burden of opportunistic infections characterize newly diagnosed HIV patients in eastern India. The physicians should keep in mind that these patients may have more than one clinical condition at presentation.

Chimeric Antigen Receptor (CAR)-T Cell Therapy for Non-Hodgkin's Lymphoma.

This review focuses on the use of chimeric antigen receptor (CAR)-T cell therapy to treat non-Hodgkin's lymphoma (NHL), a classification of heterogeneous malignant neoplasms of the lymphoid tissue. Despite various conventional and multidrug chemotherapies, the poor prognosis for NHL patients remains and has prompted the utilization of groundbreaking personalized therapies such as CAR-T cells. CAR-T cells are T cells engineered to express a CAR that enables T cells to specifically lyse tumor cells with extracellular expression of a tumor antigen of choice. A CAR is composed of an extracellular antibody fragment or target protein binding domain that is conjugated to activating intracellular signaling motifs common to T cells. In general, CAR-T cell therapies for NHL are designed to recognize cellular markers ubiquitously expressed on B cells such as CD19+, CD20+, and CD22+. Clinical trials using CAR-T cells such as ZUMA-7 and TRANSFORM demonstrated promising results compared to standard of care and ultimately led to FDA approval for the treatment of relapsed/refractory NHL. Despite the success of CAR-T therapy for NHL, challenges include adverse side effects as well as extrinsic and intrinsic mechanisms of tumor resistance that lead to suboptimal outcomes. Overall, CAR-T cell therapies have improved clinical outcomes in NHL patients and generated optimism around their future applications.

Evaluation of oral health education programs among patients with schizophrenia in India: An interventional study.

BACKGROUND: Schizophrenia is a mental disease that can drastically affect oral health. Hence, this remains a significant factor that affects oral health-related quality of life (OHRQoL). Assessing the OHRQoLin schizophrenic patients is one of the primary needs. The oral health impact profile is an impressive range of instruments that assesses the impact of oral conditions on well-being and quality of life. MATERIALS AND METHODS: A 100 schizophrenic individuals were randomly selected from the Psychiatry Department of Government Hospital, Patna, Bihar, India, and grouped into two groups: (a) Group I with.group-based sessions and (b) Group II with one-on-one interactions. Inclusion criteria: (a) Individuals who received the clinical confirmatory diagnosis of schizophrenia, (b) Patients who regularly reported to the psychologist for periodic evaluation, and (c) Patients who could follow instructions. Exclusion criteria: (a) Patients or their caregivers who were unwilling to participate in the study, (b) Patients with any other mental health disability other than schizophrenia, (c) Patients with muscular or nervous system disorders, and (d) Patients who could not follow instructions. Patients were educated on the modified Bass technique, and mean ± standard deviation plaque scores were compared at the baseline and after 12 weeks of intervention. RESULTS: Statistical analysis was performed using the Chi-square analytical test and paired "t-test." Statistically significant differences were observed in plaque scores in both groups (P < 0.001). CONCLUSION: Educational training tools help in improving oral health in schizophrenic patients.

Spatially revealed roles for lncRNAs in Drosophila spermatogenesis, Y chromosome function and evolution.

Unlike coding genes, the number of lncRNA genes in organism genomes is relatively proportional to organism complexity. From plants to humans, the tissues with highest numbers and levels of lncRNA gene expression are the male reproductive organs. To learn why, we initiated a genome-wide analysis of Drosophila lncRNA spatial expression patterns in these tissues. The numbers of genes and levels of expression observed greatly exceed those previously reported, due largely to a preponderance of non-polyadenylated transcripts. In stark contrast to coding genes, the highest numbers of lncRNAs expressed are in post-meiotic spermatids. Correlations between expression levels, localization and previously performed genetic analyses indicate high levels of function and requirement. More focused analyses indicate that lncRNAs play major roles in evolution by controlling transposable element activities, Y chromosome gene expression and sperm construction. A new type of lncRNA-based particle found in seminal fluid may also contribute to reproductive outcomes.

FEAST: A flow cytometry-based toolkit for interrogating microglial engulfment of synaptic and myelin proteins.

Although engulfment is a hallmark of microglia function, fully validated platforms that facilitate high-throughput quantification of this process are lacking. Here, we present FEAST (Flow cytometric Engulfment Assay for Specific Target proteins), which enables interrogation of in vivo engulfment of synaptic material by brain resident macrophages at single-cell resolution. We optimize FEAST for two different analyses: quantification of fluorescent material inside live cells and of engulfed endogenous proteins within fixed cells. To overcome false-positive engulfment signals, we introduce an approach suitable for interrogating engulfment in microglia from perfusion-fixed tissue. As a proof-of-concept for the specificity and versatility of FEAST, we examine the engulfment of synaptic proteins after optic nerve crush and of myelin in two mouse models of demyelination (treatment with cuprizone and injections of lysolecithin). We find that microglia, but not brain-border associated macrophages, engulf in these contexts. Our work underscores how FEAST can be utilized to gain critical insight into functional neuro-immune interactions that shape development, homeostasis, and disease.

Analysis of Fracture Resistance of Endodontically Treated Teeth with Different Restorative Materials: An In vitro Study.

Objectives: The objective of the study is to compare the fracture resistance of endodontic treated tooth restored with GIC, amalgam, and composite cements. Materials and Methods: Forty teeth were divided into 4 groups of 10 teeth each. Group I teeth were restored with silver amalgam. Group II teeth were restored with GIC. Group III teeth were restored with composite and Group IV teeth were control in which no alteration was performed. Testing machine applied force on teeth to detect fracture resistance. Results: The mean fracture resistance was maximum in Group IV (1050.2 N) followed by Group III (956.2 N), Group I (836.4 N), and Group II (766.4 N). The difference was statistically significant (P < 0.05). The mean difference of fracture resistance was significant (P > 0.05). Conclusion: Composite resin possesses highest fractures resistance as compared to GIC and silver amalgam.

Characteristics of US hospitals using extraordinary collections actions against patients for unpaid medical bills: a cross-sectional study.

OBJECTIVE: This study aims to characterise and evaluate the largest 100 hospitals in the USA that have adopted aggressive collection tactics to pursue patients with unpaid medical bills, such as lawsuits, wage garnishments and liens. DESIGN: Cross-sectional study. SETTING: We examined state and county court record systems to measure the magnitude and prevalence of these practices at the largest 100 hospitals in the UA between 1 January 2018 and 31 July 2020. MAIN OUTCOMES MEASURES: The main outcome of this study was the number of lawsuits, wage garnishments and liens. A secondary outcome was the characterisation of a hospital's safety, charitability, size and financial practices. RESULTS: Between 1 January 2018 and 31 July 2020, 26 hospitals filed 38 965 court actions (lawsuits, wage garnishments and liens) against patients for unpaid medical debt. For 16 of 26 hospitals, the dollar amount pursued in the court claim was available for 100% of cases, totalling US$71.8 million. The average aggregate amount sought by hospital lawsuits during the study period was US$4.5 million. Three hospitals filed US$56.2 million in amounts pursued in court, or 78.3% of the total amount pursued by all hospitals in the sample. In the remaining 74 hospitals, the study team did not identify extraordinary collection actions through the court system. CONCLUSIONS: Standardised medical debt collections best practices and metrics of medical debt collections quality are needed to increase public accountability for hospitals, particularly non-profit hospitals. There is a need to re-evaluate Internal Revenue Service rules pertaining to non-profit hospitals' tax-exempt status to ensure tax-exempt hospitals provide community benefits commensurate with the value of tax exemption.