Author Correction: Choosing the future of Antarctica.

On page 234 of this Perspective, '50% decrease' has been corrected online to '50% increase' in the sentence "The pH of surface waters south of 60° S decreased by 0.2 between 2017 and 2070, equivalent to a 50% increase in the concentration of hydrogen ions since the pre-industrial period1."

Choosing the future of Antarctica.

We present two narratives on the future of Antarctica and the Southern Ocean, from the perspective of an observer looking back from 2070. In the first scenario, greenhouse gas emissions remained unchecked, the climate continued to warm, and the policy response was ineffective; this had large ramifications in Antarctica and the Southern Ocean, with worldwide impacts. In the second scenario, ambitious action was taken to limit greenhouse gas emissions and to establish policies that reduced anthropogenic pressure on the environment, slowing the rate of change in Antarctica. Choices made in the next decade will determine what trajectory is realized.

Response of Pacific-sector Antarctic ice shelves to the El Niño/Southern Oscillation.

Satellite observations over the past two decades have revealed increasing loss of grounded ice in West Antarctica, associated with floating ice shelves that have been thinning. Thinning reduces an ice-shelf's ability to restrain grounded-ice discharge, yet our understanding of the climate processes that drive mass changes is limited. Here, we use ice-shelf height data from four satellite altimeter missions (1994-2017) to show a direct link between ice-shelf-height variability in the Antarctic Pacific sector and changes in regional atmospheric circulation driven by the El Niño-Southern Oscillation. This link is strongest from Dotson to Ross ice shelves and weaker elsewhere. During intense El Niño years, height increase by accumulation exceeds the height decrease by basal melting, but net ice-shelf mass declines as basal ice loss exceeds lower-density snow gain. Our results demonstrate a substantial response of Amundsen Sea ice shelves to global and regional climate variability, with rates of change in height and mass on interannual timescales that can be comparable to the longer-term trend, and with mass changes from surface accumulation offsetting a significant fraction of the changes in basal melting. This implies that ice-shelf height and mass variability will increase as interannual atmospheric variability increases in a warming climate.

High-dose chemotherapy with autologous haematopoietic stem cell support for relapsed or refractory primary CNS lymphoma: a prospective multicentre trial by the German Cooperative PCNSL study group.

To investigate safety and efficacy of high-dose chemotherapy followed by autologous stem cell transplantation (HCT-ASCT) in relapsed/refractory (r/r) primary central nervous system lymphoma (PCNSL), we conducted a single-arm multicentre study for immunocompetent patients (<66 years) with PCNSL failing high-dose methotrexate)-based chemotherapy. Induction consisted of two courses of rituximab (375 mg/m2), high-dose cytarabine (2 × 3 g/m2) and thiotepa (40 mg/m2) with collection of stem cells in between. Conditioning for HCT-ASCT consisted of rituximab 375 mg/m2, carmustine 400 mg/m2 and thiotepa (4 × 5 mg/kg). Patients commenced HCT-ASCT irrespective of response after induction. Patients not achieving complete remission (CR) after HCT-ASCT received whole-brain radiotherapy. Primary end point was CR after HCT-ASCT. We enrolled 39 patients; median age and Karnofsky performance score are 57 years and 90%, respectively. About 28 patients had relapsed and 8 refractory disease. About 22 patients responded to induction and 32 patients commenced HCT-ASCT. About 22 patients (56.4%) achieved CR after HCT-ASCT. Respective 2-year progression-free survival (PFS) and overall survival (OS) rates were 46.0% (median PFS 12.4 months) and 56.4%; median OS not reached. We recorded four treatment-related deaths. Thiotepa-based HCT-ASCT is an effective treatment option in eligible patients with r/r PCNSL. Comparative studies are needed to further scrutinise the role of HCT-ASCT in the salvage setting.

Variability of upper firn processes in West Antarctica observed with GPS reflectometry, 2007-2017.

Land ice loss from Antarctica is a significant and accelerating contribution to global sea-level rise; however, Antarctic mass-balance estimates are complicated by insufficient knowledge of surface mass-balance processes such as snow accumulation. These variables are challenging to observe on a continental scale and in situ data are sparse, so we largely rely on estimates from atmospheric models. Here, we employ a novel method, GPS interferometric reflectometry (GPS-IR), to measure upper (<2 m) firn-column thickness changes across a 23-station GPS array in West Antarctica. We compare the results with antenna heights measured in situ to establish the method's daily uncertainty (0.06 m) and with output from two atmospheric reanalysis products to categorize spatial and temporal variability of near-surface processes. GPS-IR is an effective method for monitoring surface mass-balance processes that can be applied to both historic GPS datasets and future experiments to provide critical in situ observations of processes driving surface-height evolution.

High-dose methotrexate-based immuno-chemotherapy for elderly primary CNS lymphoma patients (PRIMAIN study).

To investigate immuno-chemotherapy for elderly immuno-competent patients (⩾65 years) with newly diagnosed primary central nervous system lymphoma, we conducted a multicentre single-arm trial. One cycle consisted of rituximab (375 mg/m2, days 1, 15, 29), high-dose methotrexate (3 g/m2 days 2, 16, 30), procarbazine (60 mg/m2 days 2-11) and lomustine (110 mg/m2, day 2)-R-MPL protocol. Owing to infectious complications, we omitted lomustine during the study and consecutive patients were treated with the R-MP protocol. Three cycles were scheduled and repeated on day 43. Subsequently, patients commenced 4 weekly maintenance treatment with procarbazine (100 mg for 5 days). Primary end point was complete remission (CR) after 3 cycles. We included 107 patients (69 treated with R-MPL and 38 with R-MP). In all, 38/107 patients achieved CR (35.5%) and 15 (14.0%) achieved partial remission. R-MP was associated with a lower CR rate (31.6%) compared with R-MPL (37.7%), but respective 2-year progression-free survival (All 37.3%; R-MP 34.9%; R-MPL 38.8%) and overall survival (All 47.0%; R-MP 47.7%; R-MPL 46.0%) rates were similar. R-MP was associated with less ⩾grade 3 toxicities compared with R-MPL (71.1% vs 87.0%). R-MP is more feasible while still associated with similar efficacy compared with R-MPL and warrants further improvement in future studies.

Subglacial Lake Whillans microbial biogeochemistry: a synthesis of current knowledge.

Liquid water occurs below glaciers and ice sheets globally, enabling the existence of an array of aquatic microbial ecosystems. In Antarctica, large subglacial lakes are present beneath hundreds to thousands of metres of ice, and scientific interest in exploring these environments has escalated over the past decade. After years of planning, the first team of scientists and engineers cleanly accessed and retrieved pristine samples from a West Antarctic subglacial lake ecosystem in January 2013. This paper reviews the findings to date on Subglacial Lake Whillans and presents new supporting data on the carbon and energy metabolism of resident microbes. The analysis of water and sediments from the lake revealed a diverse microbial community composed of bacteria and archaea that are close relatives of species known to use reduced N, S or Fe and CH4 as energy sources. The water chemistry of Subglacial Lake Whillans was dominated by weathering products from silicate minerals with a minor influence from seawater. Contributions to water chemistry from microbial sulfide oxidation and carbonation reactions were supported by genomic data. Collectively, these results provide unequivocal evidence that subglacial environments in this region of West Antarctica host active microbial ecosystems that participate in subglacial biogeochemical cycling.

Antarctic ice-sheet loss driven by basal melting of ice shelves.

Accurate prediction of global sea-level rise requires that we understand the cause of recent, widespread and intensifying glacier acceleration along Antarctic ice-sheet coastal margins. Atmospheric and oceanic forcing have the potential to reduce the thickness and extent of floating ice shelves, potentially limiting their ability to buttress the flow of grounded tributary glaciers. Indeed, recent ice-shelf collapse led to retreat and acceleration of several glaciers on the Antarctic Peninsula. But the extent and magnitude of ice-shelf thickness change, the underlying causes of such change, and its link to glacier flow rate are so poorly understood that its future impact on the ice sheets cannot yet be predicted. Here we use satellite laser altimetry and modelling of the surface firn layer to reveal the circum-Antarctic pattern of ice-shelf thinning through increased basal melt. We deduce that this increased melt is the primary control of Antarctic ice-sheet loss, through a reduction in buttressing of the adjacent ice sheet leading to accelerated glacier flow. The highest thinning rates occur where warm water at depth can access thick ice shelves via submarine troughs crossing the continental shelf. Wind forcing could explain the dominant patterns of both basal melting and the surface melting and collapse of Antarctic ice shelves, through ocean upwelling in the Amundsen and Bellingshausen seas, and atmospheric warming on the Antarctic Peninsula. This implies that climate forcing through changing winds influences Antarctic ice-sheet mass balance, and hence global sea level, on annual to decadal timescales.

[Rapid identification of Candida albicans: evaluation of "Rapidec albicans". Study of 444 yeast strains]. / Identification rapide de Candida albicans: évaluation de "Rapidec albicans". Etude de 444 souches de levures.

Rapid identification of Candida albicans is of great importance as it is the most frequently isolated yeast pathogen. Rapidec albicans, a new 2-h micromethod, performs two fluorescent enzymatic activities: hexosaminidase and proline arylamidase. A total of 444 yeast strains (334 from type culture collections and 110 from recent clinical isolates) were tested. The sensitivity was 98.5% and the specificity 95.8%. When only considering the clinical strains, 47/47 Candida albicans were identified by Rapidec albicans (sensitivity 100%) but only 43/47 by the germ tube test (sensitivity 91.5%). The specificities of the two tests were respectively 98.2% and 100%. This new system is therefore very efficient for the routine diagnosis of Candida albicans in the clinical field. It is easier and quicker than the germ tube test.

Impact of hyperbilirubinaemia and transient mother-child separation in the neonatal period on mother-child attachment in the 1st year of life.

Hyperbilirubinaemia (HyB) is the most common health disturbance in the neonatal period. The aim of this prospective study is to determine whether HyB and/or phototherapy (PhT) together with transient separation during the neonatal period are associated with impaired mother-child attachment after the 1st year of life. We divided 107 healthy term infants into three groups: 29 markedly icteric infants who underwent PhT (mother-child separation), 40 mildly icteric infants without PhT and a control group of 38 nonicteric infants. At the age of 1 year a paediatric examination and a Denver test were performed, and the mother-infants pairs were observed in Ainsworth's strange situation. The results show a similar distribution of the attachment patterns in the three different groups of infants. HyB and PhT do not negatively seem to affect the quality of attachment. Analysis of additional aspects showed that maternal coping and her perception of the child appear to be more important antecedents of the quality of attachment after the 1st year of life.

[Congenital methemoglobinemia with cytochrome-b5-reductase deficiency: 4th Swiss family]. / Kongenitale Methämoglobinämie mit Mangel an Cytochrom-b5-Reduktase: vierte Schweizer Sippe.

In a female newborn presenting with pronounced cyanosis in the absence of cardiopulmonary disease, the cyanosis was due to methemoglobinemia of 33% at birth and 17% at 24 hours (upper limit 0.5%) which was found to be secondary to deficiency of red blood cell cytochrome b5 reductase (EC 1.6.2.2.). Only residual activity of this enzyme was measurable, thus indicating homozygosity. Both parents were found to be heterozygous for this inherited disease. Of the six sisters and brothers of the newborn's father, five were investigated and all found to be heterozygous for the defective allele. Measurement of cytochrome b5 reductase showed both soluble and membrane bound fractions to be affected equally in the red cells of the baby's heterozygous parents.

Jaundice and behavioral organization in the full-term neonate.

Hyperbilirubinemia is the most common problem experienced by full-term neonates during the first days of life. The short-term behavioral sequelae in infants with mild hyperbilirubinemia not requiring phototherapy were investigated by means of the Brazelton Neonatal Behavioral Assessment Scale. The behavioral integrity of 76 mildly jaundiced infants (maximum serum bilirubin 200-250 mumol/l) was compared with that of 401 control infants without clinical signs of hyperbilirubinemia (maximum serum bilirubin less than 100 mumol/l). The two groups differed on 12 of the 28 scale items reflecting five of the six dimensions of newborn behavior: habituation to disturbing stimuli when asleep, orientation to environmental events when alert, motor performance, regulation of state, and autonomic stability. The jaundiced infants showed an impaired behavioral organization compared to the control infants.

[Pregnancy in a representative Swiss population (study of pregnancy and newborn infants in Aarau). 3. Diseases and drugs in pregnancy]. / Schwangerschaftsverlauf in einem repräsentativen Schweizer Kollektiv (Aarauer Schwangerschafts- und Neugeborenenstudie). III. Krankheiten und Medikamente in der Schwangerschaft.

As part of an overall study, a cohort of 996 Swiss mothers was interviewed upon admission to the labour ward regarding illnesses, disorders and the use of drugs during pregnancy. The data are presented and compared with analogous data on the entire female population of the same age group in Switzerland, and with epidemiologic reviews of pregnancy events from other countries. Somatic illness, particularly the common cold, were reported by 55%, and complaints of a more psychosomatic character by 47%. Illness related to pregnancy was found in more than 40% of the women. Only 16% reported no illnesses or complaints during the course of pregnancy. On the other hand, 33% of the mothers had taken no medication during pregnancy. Compared with studies from other countries the use of medication in this group of women was lower, particularly self-medication for minor complaints. The women reported an average intake of 1.6 drugs. In the offspring of these mothers only a few minor somatic effects were demonstrable. The Brazelton behavioral assessment did, however, reveal some significant correlations.

[The course of pregnancy in a representative Swiss sample (Aarau Pregnancy and Newborn Infant Study). II. Stimulants in pregnancy]. / Schwangerschaftsverlauf in einem repräsentativen Schweizer Kollektiv (Aarauer Schwangerschafts- und Neugeborenenstudie). II. Genussmittel in der Schwangerschaft.

Within the framework of a study on the course of pregnancy, a cohort of 996 Swiss mothers was interviewed upon admission for delivery at Aarau Maternity Hospital regarding nicotine, alcohol, caffeine and narcotics consumption. The data are presented and compared with analogous data on the entire female population of the same age group in Switzerland and with epidemiologic reviews of pregnancy events from other countries. The relationship between these data and effects on the newborn is also discussed. This group of mothers aged 20-40 years had, even prior to pregnancy, below-average alcohol and nicotine consumption. During pregnancy nicotine use in the last trimester, though reduced, was still admitted by 18% of the gravidae despite the fact that about 3/4 of the mothers were well informed about detrimental effects on the offspring. Nicotine use by the mother had several somatic effects on the newborn, in contrast to consumption of caffeine and small amounts of alcohol. The behavioral assessment was altered by previous use of nicotine and caffeine.

[The course of pregnancy in a representative Swiss population (the Aarau Pregnancy and Newborn Infant Study). I. Social medicine aspects]. / Schwangerschaftsverlauf in einem repräsentativen Schweizer Kollektiv (Aarauer Schwangerschafts- und Neugeborenenstudie). I. Sozialmedizinische Aspekte.

Excluding multiple births, a cohort of 996 Swiss mothers was interviewed upon admission to the labour ward regarding the overall course of pregnancy, illnesses, disorders, use of drugs, and nicotine and alcohol consumption. During the postnatal stay at the hospital additional information on socioeconomic background, mental and physical stress and the pattern of medical care during pregnancy was obtained. The data are presented and compared with analogous data on the entire female population of the same age group in Switzerland and with epidemiologic reviews of pregnancy events from other countries. This group of pregnant women represents a cross-section of the average mixed small town and rural population of German-speaking Switzerland. The socioeconomic conditions for motherhood appear favorable, though the percentage of women from lower socioeconomic classes was lower than in the general population. Employment during pregnancy had no influence on birthweight and neonatal morbidity, in contrast to chronic physical and emotional stress. On average the women had eight medical checkups during pregnancy.

[Employment during pregnancy and neonatal morbidity]. / Erwerbstätigkeit während der Schwangerschaft und neonatale Morbidität.

Neonatal morbidity was higher among the babies of 521 women who were gainfully employed during pregnancy compared to those of 475 non working women of the same area (Aarau, Switzerland). The difference was lower (6%) in the part time employed than in those working full time (11%.) It was almost entirely due to the higher number of primiparae and of smokers among those women who were working during pregnancy.

[Employment during pregnancy and birth weight]. / Erwerbstätigkeit während der Schwangerschaft und Geburtsgewicht.

The average weight of the newborn was found significantly lower (almost 170 g) among 521 women with gainful employment during pregnancy compared to 475 other singleborn babies of residents of the Aarau region (Switzerland), who did not indicate such an occupation. Multivariate analysis, however, revealed that the observed difference was accounted for by the higher proportion of primiparae and of smokers among the working women, a direct influence of the occupation on birth weight could not be confirmed.

[Severe neonatal anemia associated with fetomaternal transfusion and persistent fetal circulation]. / Schwere neonatale Anämie bei fetomaterneller Transfusion mit persistierendem fetalem Kreislauf.

A newborn infant with massive fetomaternal hemorrhage is reported. The fetal blood loss led to severe late decelerations in the antepartal CTG. The newborn showed a marked anemia (Hb 4.9 g%!) and a rapidly progressive heart failure. Despite blood transfusions and digoxin therapy the infant developed the symptoms of a "persistent fetal circulation". This mechanism may have been responsible for the lethal outcome in other reported cases. A successful therapeutic approach adaptable to the different stages of severity of this dangerous perinatal condition is outlined.

[Prenatal hypoxic brain damage (prenatal CTG and postpartum CT changes]. / Antepartale hypoxische Hirnschädigung (antepartale CTG- und postpartale CT-Veränderungen).

A para III was found to have a constantly silent CTG. In two fetal blood analyses the pH was normal. During the first few hours post partum the infant had rapidly increasing neurologic disturbances with violent convulsions and coma. As early as on the first day of life the computer tomogram showed extensive, later persistent hypodense zones corresponding to severe asphyxial cerebral necrosis. Based an the course of CT changes it has to be assumed that the hypoxic crisis occurred some days prior to the onset of labor. Pathologic changes in the umbilical cord indicated that the cause could have been a transitory occlusion in utero. The computer tomogram enables cerebral insults to be dated more accurately. If prenatal hypoxia occurs repeatedly new methods of prevention must be sought.