Glaciers and Global Warming

Ice core and mass balance studies from glaciers, ice caps and ice sheets constitute an ideal medium for monitoring and studying present and past environmental change and, as such, make a valuable contribution to the present debate over anthropogenic forcing of climate. Data derived from 32 years of measurements in the Canadian Arctic show no significant trends in glacier mass balance, ice melt, or snow accumulation, although the mass balance continues to be slightly negative. Models suggest that industrial aerosol loading of the atmosphere should add to the warming effect of greenhouse gases. However, we have found a sharp increase in the concentration of industrial pollutants in snow deposited since the early 1950's which makes the trendless nature of our various time series surprising. Spatial differences in the nature of climatic change may account for the lack of trend in the Queen Elizabeth Islands but encourages similar investigations to this study elsewhere in the circumpolar region. A global warming trend over the past 150 years has been demonstrated from instrumental data and is evident in our ice cores. However, the ice core data and glacier geometry changes in the Canadian Arctic suggest the Arctic warming is more pronounced in summer than winter. The same warming trend is not unique when viewed in the context of changes over the past 10,000 or 100,000 years. This suggests the 150-year trend is part of the natural climate variability.L'analyse des carottes de glace et les mesures du bilan de masse des glaciers, des calottes glaciaires et des indlandsis permettent de déceler des changements environnementaux survenus dans le passé tout en permettant de surveiller les changements actuels. Ces études peuvent contribuer au débat portant sur les conséquences physiques de l'activité humaine sur le climat. Trente-deux ans de données accumulées sur les bilans de masse, la fonte et l'accumulation de neige sur les glaciers de l'Arctique canadien ne montrent aucune tendance significative, bien que les bilans de masse soient quelque peu négatifs. Les modèles prévoient pourtant un réchauffement provoqué par l'apport accru d'aérosols d'origine industrielle. Nous observons une forte augmentation des concentrations de polluants industriels dans la neige déposée depuis les années cinquante, ce qui rend l'absence d'une tendance dans nos observations encore plus surprenante. L'absence d'indices sur un réchauffement dans l'archipel de la Reine-Élisabeth est peut-être simplement attribuable aux variations régionales du changement climatique, un phénomène qui devrait être étudié dans d'autres régions circumpolaires. Depuis 150 ans, une tendance vers un réchauffement à l'échelle planétaire a été observée à partir des données recueillies par les instruments ainsi que dans les carottes de glace. Les données obtenues à partir des carottes de glace et de la géométrie des glaciers semblent indiquer que ce réchauffement est plus marqué l'été que l'hiver. La tendance au réchauffement n'est cependant pas exceptionnelle dans le contexte des 10 000 ou 100 000 dernières années; elle pourrait rendre compte de la variabilité naturelle du climat.Die Analyse von Eisbohrkernen und das Studium der Bilanz der Masse von Gletschem, Eiskappen und Eisdecken sind ein ausgezeichnetes Mittel, um gegenwàrtige und vergangene Umweltverânderungen zu kontrollieren und zu studieren. So kann ein wertvoller Beitrag zur gegenwàrtigen Débatte ùber den Einfluft der menschlichen Aktivitàt auf das Klima geleistet werden. Die Daten, die man durch Messungen ùber 32 Jahre in der kanadischen Arktis gewann, zeigen keine erhebliche Tendenz in der Bilanz der Gletschermasse, Eisschmelze oder Schneeakkumulation, auch wenn die Bilanz der Masse weiter leicht negativ ist. Die Modelle lassen vermuten, da8 die Ladung der Atmosphère mit Industrieaerosolen zum Treibhauseffekt beitrâgt. Jedoch haben wir einen starken Anstieg in der Konzentration industrieller Schadstoffe in dem seit den frùhen fùnfziger Jahren angesammelten Schnee, was das Fehlen einer Tendenz in unseren verschiedenen Zeitabschnitten ùberraschend macht. Ôrtliche Unterschiede in der Natur der Klimawechsel mogen fur das Fehlen einer Tendenz auf den Queen Elizabeth lnseln verantwortlich sein, doch dieser Untersuchung vergleichbare Studien sollten andernorts in der Region um den PoI durchgefùhrt werden. Eine globale Erwàrmungstendenz ùber die vergangenen 150 Jahre konnte mittels instrumenteller Messungen festgestellt werden und ist in unseren Eisbohrkernen sichtbar. Indessen lassen die Eisbohrkerndaten und Verànderungen in der Géométrie der Gletscher in der kanadischen Arktis annehmen, daft die Erwàrmung der Arktis im Sommer deutlicher ist als im Winter. Dièse Erwàrmungstendenz ist nicht auftergewôhnlich, wenn man sie im Kontext der Verânderungen in den letzten 10,000 oder 100,000 Jahren sieht. Die 150 Jahre-Tendenz ist wohl Teil der natùrlichen Klimavariabilitàt

Deep far infrared ISOPHOT survey in "Selected Area 57", I. Observations and source counts

We present here the results of a deep survey in a 0.4 sq.deg. blank field in Selected Area 57 conducted with the ISOPHOT instrument aboard ESAs Infrared Space Observatory (ISO) at both 60 um and 90 um. The resulting sky maps have a spatial resolution of 15 x 23 sq.arcsec. per pixel which is much higher than the 90 x 90 sq.arcsec. pixels of the IRAS All Sky Survey. We describe the main instrumental effects encountered in our data, outline our data reduction and analysis scheme and present astrometry and photometry of the detected point sources. With a formal signal to noise ratio of 6.75 we have source detection limits of 90 mJy at 60 um and 50 mJy at 90 um. To these limits we find cumulated number densities of 5+-3.5 per sq.deg. at 60 um and 14.8+-5.0 per sq.deg.at 90 um. These number densities of sources are found to be lower than previously reported results from ISO but the data do not allow us to discriminate between no-evolution scenarios and various evolutionary models.Comment: 15 pages, 11 figures, accepted by Astronomy & Astrophysic

Spatio-temporal trends in stock mixing of eastern and western Baltic cod in the Arkona Basin and the implications for recruitment

In the Baltic Sea, two genetically distinct cod populations occur, the eastern and the western Baltic cod. Since 2006, cod abundance has increased substantially in the Arkona Basin (SD 24), the potential mixing area between the two stocks management areas, presumably due to spill-over from the eastern stock. In this study, the spatio-temporal dynamics of stock mixing were analysed using shape analysis of archived otoliths. Further, the impact of eastern cod immigration on recruitment in the western Baltic Sea was investigated using hydrographic drift modelling. The percentage of eastern Baltic cod in the Arkona Basin increased from ca. 30% before 2005 to >80% in recent years. Geographic patterns in stock mixing with a pronounced east–west trend suggest that immigration occurs north of Bornholm, but propagates throughout the Arkona Basin. The immigration cannot be attributed to spawning migration, as no seasonal trend in stock mixing was observed. Based on environmental threshold levels for egg survival and time-series of hydrography data, the habitat suitable for successful spawning of eastern cod was estimated to range between 20 and 50% of the maximum possible habitat size, limited by primarily low salinity. Best conditions occurred irregularly in May–end June, interspersed with years where successful spawning was virtually impossible. Using a coupled hydrodynamic modelling and particle-tracking approach, the drift and survival of drifters representing eastern cod eggs was estimated. On average, 19% of the drifters in the Arkona Basin survive to the end of the yolk-sac stage, with mortality primarily after bottom contact due to low salinity. The general drift direction of the surviving larvae was towards the east. Therefore, it is the immigration of eastern cod, rather than larval transport, that contributes to cod recruitment in the western Baltic Sea

Vesicular glutamate release from central axons contributes to myelin damage

Neuronal activity can lead to vesicular release of glutamate. Here the authors demonstrate that vesicular release of glutamate occurs in axons during ischemic conditions, and that an allosteric modulator of GluN2C/D is protective in models of ischemic injury

Trends in Proton-Pump Inhibitor Use Among Danish Adults:A Nationwide Drug Utilization Study 2015–2023

The global increase in proton-pump inhibitor (PPI) use has raised concerns about their appropriate use, particularly due to potential overprescription and associated adverse effects. This study examines PPI utilization patterns among Danish adults from 2015 to 2023 using the Danish nationwide health registries. We estimated the annual incidence rate (users per 100 person-years) and monthly prevalence (proportion with a filled prescription or sufficient tablets). Treatment duration was assessed using the ‘proportion of patients covered’ and the Kaplan–Meier method. We also calculated the proportion of adults with concomitant use of ulcerogenic drugs over time. We identified 1 729 440 adults who filled at least one PPI prescription during 2015–2023. The prevalence increased from 7.0% in 2015 to 8.2% in 2023, while incidence rate remained stable at ~3 users per 100 person years. PPI use increased with age. Three years after initiation, 17% used PPIs, while 1.5% had remained on continuous treatment. In 2023, 50% of users had concomitant ulcerogenic drug use, a 3.2% increase since 2015. The prevalence of PPI use in Denmark has risen markedly reaching a high stable level, with a clear age-dependent trend. Increased attention to appropriate PPI use is necessary to ensure rational prescribing and prevent potential overuse.</p

The lancet weight determines wheal diameter in response to skin prick testing with histamine

BACKGROUND:Skin prick test (SPT) is a common test for diagnosing immunoglobulin E-mediated allergies. In clinical routine, technicalities, human errors or patient-related biases, occasionally results in suboptimal diagnosis of sensitization. OBJECTIVE:Although not previously assessed qualitatively, lancet weight is hypothesized to be important when performing SPT to minimize the frequency of false positives, false negatives, and unwanted discomfort. METHODS:Accurate weight-controlled SPT was performed on the volar forearms and backs of 20 healthy subjects. Four predetermined lancet weights were applied (25 g, 85 g, 135 g and 265 g) using two positive control histamine solutions (1 mg/mL and 10 mg/mL) and one negative control (saline). A total of 400 SPTs were conducted. The outcome parameters were: wheal size, neurogenic inflammation (measured by superficial blood perfusion), frequency of bleeding, and the lancet provoked pain response. RESULTS:The mean wheal diameter increased significantly as higher weights were applied to the SPT lancet, e.g. from 3.2 ± 0.28 mm at 25 g to 5.4 ± 1.7 mm at 265 g (p<0.01). Similarly, the frequency of bleeding, the provoked pain, and the neurogenic inflammatory response increased significantly. At 265 g saline evoked two wheal responses (/160 pricks) below 3 mm. CONCLUSION AND CLINICAL RELEVANCE:The applied weight of the lancet during the SPT-procedure is an important factor. Higher lancet weights precipitate significantly larger wheal reactions with potential diagnostic implications. This warrants additional research of the optimal lancet weight in relation to SPT-guidelines to improve the specificity and sensitivity of the procedure

TEDDI: Radiotherapy delivery in deep inspiration for pediatric patients - A NOPHO feasibility study

Background Radiotherapy (RT) delivered in deep inspiration breath-hold (DIBH) is a simple technique, in which changes in patient anatomy can significantly reduce the irradiation of the organs at risk (OARs) surrounding the treatment target. DIBH is routinely used in the treatment of some adult patients to diminish the risk of late effects; however, no formalized studies have addressed the potential benefit of DIBH in children. Methods/Design TEDDI is a multicenter, non-randomized, feasibility study. The study investigates the dosimetric benefit of RT delivered in DIBH compared to free breathing (FB) in pediatric patients. Also, the study aims to establish the compliance to DIBH and to determine the accuracy and reproducibility in a pediatric setting. Pediatric patients (aged 5–17 years) with a tumor in the mediastinum or upper abdomen with the possible need of RT will be included in the study. Written informed consent is obligatory. Prior to any treatment, patients will undergo a DIBH training session followed by a diagnostic PET/CT- or CT-staging scan in both DIBH and FB. If the patient proceeds to RT, a RT planning CT scan will be performed in both DIBH and FB and two separate treatment plans will be calculated. The superior treatment plan, i.e. equal target coverage and lowest overall dose to the OARs, will be chosen for treatment. Patient comfort will be assessed daily by questionnaires and by adherence to the respiratory management procedure. Discussion RT in DIBH is expected to diminish irradiation of the OARs surrounding the treatment target and thereby reduce the risk of late effects in childhood cancer survivors

Glial contribution to excitatory and inhibitory synapse loss in neurodegeneration

Synapse loss is an early feature shared by many neurodegenerative diseases, and it represents the major correlate of cognitive impairment. Recent studies reveal that microglia and astrocytes play a major role in synapse elimination, contributing to network dysfunction associated with neurodegeneration. Excitatory and inhibitory activity can be affected by glia-mediated synapse loss, resulting in imbalanced synaptic transmission and subsequent synaptic dysfunction. Here, we review the recent literature on the contribution of glia to excitatory/inhibitory imbalance, in the context of the most common neurodegenerative disorders. A better understanding of the mechanisms underlying pathological synapse loss will be instrumental to design targeted therapeutic interventions, taking in account the emerging roles of microglia and astrocytes in synapse remodeling