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Physical processes leading to extreme day-to-day temperature change – Part 1: Present-day climate
Get PDFExtreme temperature changes from one day to another that are associated with either warming or cooling can have a significant impact on health, the environment, and society. Previous studies have shown that such day-to-day temperature (DTDT) changes are typically more pronounced in the extratropics than the tropics. However, the underlying physical processes and the relationship between extreme events and the large-scale atmospheric circulation remain poorly understood. Here, these processes are investigated for different locations around the globe based on ERA5 reanalysis data and Lagrangian backward-trajectory calculations. We show that extreme DTDT changes in the extratropics are generally associated with changes in air mass transport, particularly shifts from warmer to colder air parcels or vice versa that are linked to regionally specific synoptic-scale circulation anomalies (ridge or trough patterns). These dominant effects of advection are modulated by changes in adiabatic and diabatic processes in the transported air parcels, which either amplify or dampen DTDT decreases (cooling events) and increases (warming events) depending on the region and season. In contrast, extreme DTDT changes during December–February in the tropics are controlled by local processes rather than changes in advection. For instance, the most significant DTDT decreases are associated with a shift from less cloudy to more cloudy conditions, highlighting the crucial role of solar radiative heating. The mechanistic insights into the extreme DTDT changes obtained in this study can help improve the prediction of such events and anticipate future changes in their occurrence frequency and intensity, which will be investigated in part 2 of this study
Temperature- and light-driven spin-state transition
No full textWe investigated the properties of the [Fe{H2B(pz)(pypz)}2] spin-crossover complex deposited on highly oriented pyrolytic graphite (HOPG) by x-ray absorption spectroscopy (XAS) in the temperature range from 10 to 350 K for sample thicknesses from 0.9(1) to 1.3(2) ML. The highest temperature at which light can excite the system to a long-lived metastable high-spin state (TLIESST) and the temperature at which a thermal spin transition occurs (T_1/2) for the thin film samples are found as about 45 and 325 K, respectively, in agreement with the bulk values. The bulk phase has previously been studied by magnetic susceptibility measurements where it was found that two different polymorphic modifications exist. These findings suggest a potential correlation between TLIESST and the high T_1/2 from the different film thicknesses of the tridentate [Fe{H2B(pz)(pypz)}2] spin-crossover molecule, with thinner samples exhibiting lower T_1/2 values. Finally, the highest high-spin fraction achieved for [Fe{H2B(pz)(pypz)}2] is 0.77 for samples of 0.9(1) and 1.1(1) ML on HOPG at 10 K and constant light irradiation
Forecasting induced seismicity in enhanced geothermal systems using machine learning: challenges and opportunities
Get PDFInduced seismicity poses a significant challenge to the safe and sustainable development of Enhanced Geothermal Systems (EGS). This study explores the application of machine learning (ML) for forecasting cumulative seismic moment (CSM) of induced seismic events to evaluate reservoir stability in response to fluid injections. Using data from the Cooper Basin (Australia), the St1 Helsinki geothermal project (Finland), and a controlled laboratory injection experiment, we evaluate ML models that integrate catalogue and operational features with various frameworks. Results indicate that feature-rich models outperform simpler ones in complex seismic environments like the Cooper Basin and laboratory cases, where seismicity is promoted by earthquake interaction and fault reactivation. However, in scenarios like St1 Helsinki, with minimal event clustering, additional features offer limited predictive benefits. While ML models are promising, several challenges impede reliable forecasting, including data scarcity from operational wells, the extrapolation demands of cumulative output (i.e. CSM) and the difficulty of predicting abrupt CSM increases for large seismic events. Enhancing model robustness requires synthetic data augmentation and improved feature selection capable of capturing diverse reservoir dynamics. These advancements may enable more accurate near real-time forecasts of problematic induced seismic events, informing operational decisions to mitigate seismic risks while maximizing energy extraction, and hence offering a pathway for broader adoption of ML in renewable energy development and management
Environmental response of coastal lake Huelde, Chile, after tsunami inundation and earthquake-induced subsidence
Get PDFWith extreme sea-level events, including storms and tsunamis, projected to flood the coastal zone more often over the coming centuries, understanding their impacts is paramount. Whilst immediate impacts are well studied, we know relatively little about how coastal environments recover in the subsequent years and decades after such events. Here we investigate the response and recovery dynamics of the sedimentary system and biological environment to saltwater inundation into a coastal lake on Chiloé Island, northern Chilean Patagonia, from two tsunamis (in 1960 CE and 2670 cal yr BP) and as a consequence of earthquake-induced land-level change. We utilise an existing unique well-dated sediment record from Lake Huelde containing multiple tsunami inundation events, which provides an exceptional sedimentary archive and opportunity to improve understanding of the impacts of marine inundation on freshwater lake ecosystems by re-examining the sediments for new proxies. Analysis of the geochemistry of lacustrine sediments and the biota (algae, aquatic invertebrates and pollen) preserved within them, shows that the sedimentary and ecological responses to two tsunamis in 1960 CE and 2670 cal yr BP differed in nature and timing. We show that biota responded more immediately to the 2670 cal yr BP event, and impacts were longer lasting; saline anoxic bottom water can prevail for decades to centuries post-inundation. We suggest that key drivers of post-tsunami response and recovery are initially the rate of refreshment after saltwater inundation, and over the longer-term, connectivity to the ocean. In an area affected by earthquake-induced land-level changes, these can influence not only the establishment of sustained connection to the ocean, but can also bring the lake ecosystem within reach of storms and spring high tides, which can impact post-tsunami recovery. We therefore suggest that at Lake Huelde, relative sea (land)-level change, and hence tidal connection of the lacustrine system to the ocean, plays a critical role in ecosystem response
Über die Isolierung einzelner Trypanosomen
No full textDigitalisat der Ausgabe von 1914, erschienen 202
Coupled Water–Energy–Carbon Study of the Agricultural Sector in the Great River Basin: Empirical Evidence from the Yellow River Basin, China
Get PDFIn the context of sustainable development, water resources, energy, and carbon emissions are pivotal factors influencing the rational planning of economic development and the secure establishment of ecological barriers. As a core food production area, how can the Great River Basin balance the pressure on the “water–energy–carbon” system (WEC) to realize the coordinated development of “nature–society–economy”? Taking the Yellow River Basin in China as the research object, this paper explores the coupling characteristics and virtual transfer trends of WEC in the agricultural sector under the condition of mutual constraints. The results show the following: (1) On the dynamic coupling characteristics, W-E and E-C are strongly coupled with each other. The optimization of water resource allocation and the development of energy-saving water use technology make the W-E consumption show a downward trend, and the large-scale promotion of agricultural mechanization makes the E-C consumption show an upward trend. (2) On the spatial distribution of transfer, there is an obvious path dependence of virtual WEC transfer, showing a trend of transfer from less developed regions to developed regions, and the coupling strength decreases from developed regions to less developed regions. The assumption of producer responsibility serves to exacerbate the problem of inter-regional development imbalances. (3) According to the cross-sectoral analysis, water resources are in the center of sectoral interaction, and controlling the upstream sector of the resource supply will indirectly affect the synergistic relationship of WEC, and controlling the downstream sector of resource consumption will indirectly affect the constraint relationship of WEC. This study provides theoretical and methodological references for the Great River Basin to cope with the resource and environmental pressure brought by global climate change and the effective allocation of inter-regional resources
Clinical characteristics and types of myocardial infarction in patients with post-stroke acute myocardial injury
Get PDFBisherige Studien haben gezeigt, dass ein relevanter Anteil der Patient:innen mit akutem ischämischen Schlaganfall zusätzlich eine akute Myokardschädigung und damit verbunden schlechtere Behandlungsergebnisse aufweisen. Der akuten Myokardschädigung können verschiedene Ätiologien zugrunde liegen, darunter der akute Myokardinfarkt (MI), dessen Definitionskriterien in der 4th universal definition of myocardial infarction (4th UDMI) enthalten sind. Insbesondere der akute Typ 2 MI, verursacht durch ein Missverhältnis der myokardialen Sauerstoffversorgung (myokar- diale „Bedarfsischämie“), scheint eine größere Rolle bei Schlaganfallpatient:innen zu spielen. Allerdings gibt es kaum Daten bezüglich der Prävalenz eines Typ 2 MI sowie von assoziierten Auslösern (Trigger) für eine solche Bedarfsischämie bei Patient:innen mit ischämischem Schlaganfall.
Alle konsekutiv zwischen dem 01.01.2019 – 31.12.2020 aufgenommenen Patient:innen mit einem ischämischen Schlaganfall und einem laborchemisch nachgewiesenen akuten Myokardschaden (hoch-sensitives kardiales Troponin T (hs-cTnT) über dem oberen Referenzwert mit einem Anstieg oder Abfall um >20% in der seriellen Messung) wurden in dieser Arbeit retrospektiv bezüglich der Erfüllung der Diagnosekriterien eines akuten MI sowie des Vorliegens prädefinierter Trigger einer Bedarfsischämie untersucht.Von den 250 untersuchten Patient:innen konnte bei 41 (16,4%) die Diagnose eines akuten MI gestellt werden. Davon hatten 24 einen Typ 2 MI, 15 einen Typ 1 MI und 2 einen MINOCA. Die hs-cTnT-Werte lagen bei Patient:innen mit Typ 1 MI höher als bei denen mit Typ 2 MI (212 ng/L [90-799] vs. 64 ng/L [27-324], p = 0,030). Ein nicht-ischämischer Myokardschaden konnte bei 23 (9,2%) Patient:innen identifiziert werden. Bei 186 (74,4%) war keine sichere ätiologische Zuordnung des akuten Myokardschadens möglich. Hauptgrund dafür war nicht-durchgeführte kardiale Diagnostik. Insgesamt zeigten von allen untersuchten Patient:innen 102 (40,8%) einen Trigger für eine myokardiale Bedarfsischämie (am häufigsten hypertensive Entgleisungen (51,0%), respiratorische Insuffizienzen (45,1%), Tachyarrhythmien (12,7%)). Bei 67 (26,8%) Patient:innen konnte ein unvollständiger Trigger gefunden werden. Patient:innen mit einem Trigger für eine Bedarfsischämie wiesen eine höhere Schlaganfallschwere (NIHSS 7 [3-17] vs. 4 [1-8], p < 0,001) und häufiger eine Beteiligung des insulären Kortex durch den Schlaganfall (34,7% vs. 19,8%) auf.Ein großer Anteil an Patient:innen mit ischämischen Schlaganfall und akuter Myokardschädigung weisen Trigger einer Bedarfsischämie auf. Höhere Troponinverlaufswerte deuten auf einen akuten Typ 1 MI hin, wohingegen Schlaganfall-spezifische Faktoren beim Typ 2 MI eine größere Rolle einnehmen.Previous studies have shown a high frequency of acute myocardial injury in patients with acute
ischemic stroke and a strong association with unfavorable clinical outcome. Acute myocardial
injury can be caused by various etiologies including acute myocardial infarction (MI). Especially
type 2 MI, due to imbalance in myocardial oxygen supply and demand (myocardial demand ische mia) seems to be relevant in patients with acute ischemic stroke. However, data regarding the
frequency of triggering factors and prevalence of type 2 MI in stroke patients are lacking.
Methods
Between 01.01.2019 – 31.12.2020, all consecutive patients with ischemic stroke und acute myo cardial injury (defined according to the 4th universal definition of MI: high-sensitivity cardiac tro ponin T (hs-cTnT) > upper reference limit (URL) with a subsequent rise and/or fall >20%) were
retrospectively screened for fulfilling diagnostic criteria of MI and for presence of triggers of my ocardial demand ischemia.
Results
Among 250 analyzed patients, 41 (16,4%) fulfilled criteria of acute MI, including 24 with type 2
MI, 15 with type 1 MI and 2 with MINOCA. Serial hs-cTnT levels were higher in patients with
type 1 MI compared to those with type 2 MI (212 ng/L [90-799] vs. 64 ng/L [27-324], p = 0,030).
Non-ischemic myocardial injury has been detected in 23 (9,2%) patients. In 186 (74,4%) patients
an etiologic classification of the acute myocardial injury was not possible. Main reason was miss ing diagnostic. Trigger of myocardial demand ischemia were found in 102 (40,8%) patients
(mainly severe hypertension (51,0%), respiratory insufficiency (45,1%), sustained tachycardia
(12,7%)). A probable trigger was found in 67 (26,8) patients. Patients with identified triggers for
demand ischemia had higher stroke severity (NIHSS 7 [3-17] vs. 4 [1-8], p < 0,001) and more
often an involvement of the insular cortex (34,7% vs. 19,8%).
Conclusion
A high proportion of patients with ischemic stroke and acute myocardial injury have evident trig gers for myocardial demand ischemia. Higher serial hs-cTnT-levels suggest type 1 MI, while
stroke-specific factors seem to be more common in type 2 MI
Infections with the hepatitis E virus in immunocompromised patients with hematologic diseases
Get PDFEinleitung: HEV-Infektionen treten weltweit sehr häufig auf. Während akute Infektionen in Europa meist asymptomatisch verlaufen und spontan ausheilen, können chronische Verläufe, insbesondere bei immunkompromittierten Patientinnen und Patienten, zur Leberzirrhose und einem Leberversagen führen. Ribavirin ist die einzige für die Behandlung dieser Infektion wirksame Substanz, ist allerdings hierfür nicht zugelassen. Es gibt nur eine begrenzte Zahl an Berichten zu HEV-Infektionen bei immungeschwächten Patienten, mit Ausnahme von Patientinnen und Patienten nach Organtransplantation. Die Elemente der Immunantwort, deren Beeinträchtigung unter Immunsuppression chronische HEV-Infektionen begünstigt, sind bei hämatologischen Patientinnen und Patienten wenig erforscht. Ziele dieser Arbeit waren die systematische Erfassung von Krankheits- und Behandlungscharakteristika immunkompromittierter Patientinnen und Patienten mit hämatologischer Erkrankung und HEV-Infektion, sowie die Identifizierung von Faktoren mit Einfluss auf den Verlauf der Infektion und das Therapieansprechen.
Methodik: Hämatologische Patientinnen und Patienten mit nachgewiesener HEV-Infektion wurden über die Labordatenbank des Instituts für Virologie der Charité identifiziert. Klinische und therapeutische Merkmale wurden gesammelt und analysiert.
Ergebnisse: Insgesamt wurden 22 Patientinnen und Patienten identifiziert (Lymphom 12, akute Leukämie 7, kombinierter Immundefekt 2, solider Tumor 1). Bei 11 von 12 Patientinnen und Patienten ohne antivirale Therapie kam es zu einer spontanen Ausheilung der Infektion, darunter 3 bzw. 2 Patienten nach allogener bzw. autologer Stammzelltransplantation. Zehn Patientinnen und Patienten wurden mit Ribavirin behandelt; bei 6 dieser Patientinnen und Patienten führte dies zu einem anhaltenden virologischen Ansprechen (SVR). Drei Patientinnen und Patienten erlitten ein Rezidiv der Infektion nach Ribavirin. Es zeigte sich kein Ansprechen auf einen erneuten Therapieversuch mit Ribavirin und Peginterferon alfa bei einer Patientin. Bei 2 Patienten nach autologer Stammzelltransplantation zeigte sich unter erfolgreicher Therapie mit Ribavirin ein Anstieg der CD4+ T-Zellzahlen von <100/μl in den Normbereich. Bei einem weiteren Patienten mit CLL und normwertigen CD4+ T-Zellen kam es, trotz eines ausgeprägten Antikörpermangels, zu einer spontanen Ausheilung der Infektion. Insgesamt zeigte sich ein Anstieg der CD4+ T-Zellen bei 5 Patientinnen und Patienten mit SVR.
Schlussfolgerung: CD4+ T-Zellen spielen mutmaßlich eine wesentliche Rolle bei der Elimination des Hepatitis-E-Virus. Eine Ribavirintherapie erscheint bei Patientinnen und Patienten mit HEV-Infektion, die initial keine CD4-Lymphopenie zeigen, nicht unmittelbar notwendig. Die frühzeitige Gabe von Ribavirin bei Patientinnen und Patienten mit CD4-Lymphopenie erscheint hingegen sinnvoll, um eine chronische HEV-Infektion zu vermeiden. Möglicherweise ist bei diesen Patienten ein Anstieg der Zahl an CD4+ T-Zellen prädiktiv für ein Ansprechen auf eine Therapie mit Ribavirin.Introduction: Infections with the Hepatitis E Virus (HEV) are very common and occur worldwide. In Europe, acute HEV infections are often asymptomatic and resolve spontaneously in healthy individuals. However, chronic infections may occur in immunocompromised individuals and could result in liver cirrhosis and liver failure in these patients. Ribavirin is the only effective medication for the treatment of infections with HEV, but this compound is not approved for this indication. Published reports about HEV infections in immunocompromised patients, other than solid organ transplant recipients, are scarce. There is still a limited understanding of the factors associated with immunosuppression in hematologic patients that have an impact on the course of chronic HEV infections. This study aims to assess clinical and treatment characteristics of HEV infections in these patients. Furthermore, potential risk factors associated with the outcomes of infections and treatment responses were compiled and analyzed.
Methods: Patients with hematologic diseases and HEV infection were identified from the laboratory database of the Institute of Virology of the Charité. Clinical and therapeutic features were retrospectively collected and analyzed.
Results: Overall, 22 patients were identified (lymphoma 12, acute leukemia 7, combined immunodeficiency 2, solid tumor 1). Eleven of 12 patients without antiviral therapy cleared the infection spontaneously. Among these, 3 patients, who had undergone an autologous stem cell transplantation, experienced a SVR despite not having received ribavirin. Ten patients were treated with ribavirin, which resulted in a SVR in 6 patients. Three patients experienced a relapse of the infection after the termination of ribavirin. One of these patients unsuccessfully received another course with ribavirin and peginterferon alfa. Parallel to a virological response under ribavirin therapy, 2 patients experienced an increase of CD4+ T cells from <100/μL to normal levels. A single patient with CLL and normal numbers of CD4+ T cells, but persistent hypogammaglobulinemia, cleared the infection spontaneously. Overall, an increase of CD4+ T cells was observed in 5 patients in parallel to a resolving HEV infection.
Conclusion: It appears likely that CD4+ T cells play a key role in the clearance of the hepatitis E virus. Early ribavirin therapy in hematologic patients with HEV infections and without CD4-lymphopenia, appears unnecessary. However, patients with CD4-lymphopenia might benefit from early ribavirin therapy, to prevent chronic infections with its devastating consequences. In these patients, an increase in the number of CD4+ T cells may be predictive of a response to ribavirin therapy
Textural, mineralogical, and geochemical evidence for apatite metasomatism and REE mobility within the Corvo orebody at the Neves Corvo Cu-Zn-Pb(-Sn) deposit (Iberian Pyrite Belt)
Get PDFThe Neves Corvo Cu-Zn-Pb(-Sn) deposit (Portugal) is one of the largest volcanogenic massive sulfide deposits (VMS) worldwide, hosted by Upper Devonian to Early Carboniferous rocks. Originally, it contained an early structurally controlled tin orebody (stockwork and massive cassiterite), which has now been mined out. In this study, we report the first occurrence of phosphate minerals (apatite, florencite, and xenotime) within the tin stockwork at Neves Corvo. We present a high-resolution multi-analytical study using petrographic, mineral chemistry, and whole-rock geochemical methods to understand the genesis of these phosphates and their implications for tin at the Neves Corvo deposit. Our results demonstrate that apatite forms coevally with cassiterite and has low trace element contents except for S, Sr, Y, and MREE (Middle Rare Earth Elements; 10–100 ppm) with a bell-shaped chondrite (C1) normalized REE pattern. We suggest that apatite likely formed as chlorapatite or oxyapatite that was subsequently metasomatized to fluorapatite with minor carbonate during hydrothermal alteration related to sulfide mineralization. The REE pattern of apatite, together with the presence of secondary phosphates (florencite and xenotime), indicates preferential scavenging of REE to form the latter phases due to the interaction with NaCl-rich and, to a minor extent, fluorine-rich fluids in an aluminum-saturated system. This study underscores how the analyses of primary and secondary phosphate minerals can help to track the evolution of the hydrothermal system and partially constrain the fluid composition and fluid-rock interaction processes. Therefore, the approaches outlined here are applicable to any hydrothermal ore-forming system where phosphate phases are formed
Genomic innovations underlying the transition to complex societies in termites
Get PDFThe transition from solitary individuals to societies is considered a major evolutionary transition. An insect society, or colony, is a complex system composed of many interdependent nestmates through whose interactions emerge a certain level of order and robustness. In a termite colony, order and robustness can be considered to be synonymous with division of labour and a social immune system, respectively. How these emergent properties evolved remains a major unanswered question in evolutionary biology. Here, I aim to tackle this topic from a genomic and transcriptomic perspective. First, I engaged in the sequencing of over 47 genomes of termites and cockroaches in order to generate a previously lacking basis of fundamental genomic knowledge, increasing the number of high-quality termite genomes by six-fold. Using this foundation, I first investigated how genomic traits evolved over termite phylogeny, and linked multifaceted patterns of gene and genome evolution to major shifts in termite diet and symbiosis. Secondly, I explored the genomic and genetic bases of sociality by comparing genomes and gene expression patterns across 29 near-chromosome quality cockroaches and termite genomes sampled along a broad spectrum of social complexity, including termite lineages representing convergent transitions towards bifurcated development and true worker phenotypes. Alongside global genomic signatures of selection, I examined patterns of gene family expansion and contraction at key ecological and social transitions. Comparative analysis of differentially expressed genes and co-expression networks are then conducted to search for evidence of conservation and co-option in the termite “genetic toolkit” and to gain insight into the evolutionary origins of termite division of labour. Thirdly, I investigated the evolution of termite immune genes and their relationship with social and ecological traits. I analyzed the evolution of 34 immune gene families and characterized the major components of four canonical immune pathways. I discuss how the evolution of certain immune gene families may have enabled social immunity to evolve and be maintained. Finally, I bring together these two emergent properties, sociality and social immunity, alongside their genomic basis to discuss their commonalities and potential interdependency, and by using sociality in termites as a case study, I consider the potential of a general molecular mechanism for the emergence of evolutionary innovation