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The region of the Andean back-arc of northwestern Argentina has been struck by several magnitude >= 6 crustal earthquakes since the first historically recorded event in 1692. One of these events corresponds to the Anta earthquake on 25 August 1948, with epicenter in the Santa Barbara System causing three deaths and severe damage in Salta and Jujuy provinces with maximum Modified Mercalli seismic intensities (MMI) of IX. We collected and digitized analog seismograms of this earthquake from worldwide seismic observatories in order to perform first-motion analysis and modeling of long-period teleseismic P-waveforms. Our results indicate a simple seismic source of M0 = 2.85 x 1019 N m consistent with a moment magnitude Mw = 6.9. We have also tested for the focal depth determining a shallow source at 8 km with a reverse focal mechanism solution with a minor dextral strike-slip component (strike 20 degrees, dip 30 degrees, rake 120 degrees) from the best fit of waveforms. Using magnitude size empirical relationships, the comparison of the obtained Mw 6.9 magnitude value and the ca. 10,000 km2 area of MMI >= IX from our seismic intensity map, which was obtained from newspaper and many historical reports, indicates a rupture length of 42 +/- 8 km for the Anta earthquake. We show our results in a 3D geological model around the epicentral area, which integrates modern seismicity, geological data, and information of a previously studied east-west cross section located a few kilometers south of the 1948 epicenter. The integration of all available information provides evidence of the re-activation of the Pie de la Sierra del Gallo fault during the 1948 Mw 6.9 shallow earthquake; this thrust fault bounds the Santa Barbara System along its western foothill.
How tone, intonation and emotion shape the development of infants' fundamental frequency perception
(2022)
Fundamental frequency (integral(0)), perceived as pitch, is the first and arguably most salient auditory component humans are exposed to since the beginning of life.
It carries multiple linguistic (e.g., word meaning) and paralinguistic (e.g., speakers' emotion) functions in speech and communication.
The mappings between these functions and integral(0) features vary within a language and differ cross-linguistically. For instance, a rising pitch can be perceived as a question in English but a lexical tone in Mandarin. Such variations mean that infants must learn the specific mappings based on their respective linguistic and social environments.
To date, canonical theoretical frameworks and most empirical studies do not view or consider the multi-functionality of integral(0), but typically focus on individual functions. More importantly, despite the eventual mastery of integral(0) in communication, it is unclear how infants learn to decompose and recognize these overlapping functions carried by integral(0). In this paper, we review the symbioses and synergies of the lexical, intonational, and emotional functions that can be carried by integral(0) and are being acquired throughout infancy.
On the basis of our review, we put forward the Learnability Hypothesis that infants decompose and acquire multiple integral(0) functions through native/environmental experiences. Under this hypothesis, we propose representative cases such as the synergy scenario, where infants use visual cues to disambiguate and decompose the different integral(0) functions. Further, viable ways to test the scenarios derived from this hypothesis are suggested across auditory and visual modalities.
Discovering how infants learn to master the diverse functions carried by integral(0) can increase our understanding of linguistic systems, auditory processing and communication functions.
In-depth understanding of the reorganization of the hydrological cycle in response to global climate change is crucial in highly sensitive regions like the eastern Mediterranean, where water availability is a major factor for socioeconomic and political development.
The sediments of Lake Lisan provide a unique record of hydroclimatic change during the last glacial to Holocene transition (ca. 24-11 ka) with its tremendous water level drop of similar to 240 m that finally led to its transition into the present hypersaline water body-the Dead Sea.
Here we utilize high-resolution sedimentological analyses from the marginal terraces and deep lake to reconstruct an unprecedented seasonal record of the last millennia of Lake Lisan. Aragonite varve formation in intercalated intervals of our record demonstrates that a stepwise long-term lake level decline was interrupted by almost one millennium of rising or stable water level.
Even periods of pronounced water level drops indicated by gypsum deposition were interrupted by decades of positive water budgets.
Our results thus highlight that even during major climate change at the end of the last glacial, decadal to millennial periods of relatively stable or positive moisture supply occurred which could have been an important premise for human sedentism.
In the Shadow of Ukraine
(2022)
In 2022, India captured global attention over its response to the war in Ukraine. While calling for both parties' return to diplomacy, India abstained from several United Nations resolutions condemning Russian aggression. For a country that ostensibly subscribes to the values of democracy and territorial integrity, its response appeared frustrating and contradictory, but it is broadly consistent with its long-standing policy of non-alignment. Although India's relationship with China is increasingly contentious, New Delhi is not yet fully convinced that it is in India's interest to swing westwards. The country's relations with Russia and China are deep, complex and substantive. In addition to the military and economic benefits it derives from its connection with Russia, New Delhi and Moscow share an avowed preference for a more equal, multipolar world. India will eventually have to reflect on the extent to which it can sustain its balancing act.
Non-Markovian diffusion of excitons in layered perovskites and transition metal dichalcogenides
(2022)
The diffusion of excitons in perovskites and transition metal dichalcogenides shows clear anomalous, subdiffusive behaviour in experiments.
In this paper we develop a non-Markovian mobile-immobile model which provides an explanation of this behaviour through paired theoretical and simulation approaches.
The simulation model is based on a random walk on a 2D lattice with randomly distributed deep traps such that the trapping time distribution involves slowly decaying power-law asymptotics.
The theoretical model uses coupled diffusion and rate equations for free and trapped excitons, respectively, with an integral term responsible for trapping.
The model provides a good fitting of the experimental data, thus, showing a way for quantifying the exciton diffusion dynamics.
Inorganic perovskite solar cells show excellent thermal stability, but the reported power conversion efficiencies are still lower than for organic-inorganic perovskites. This is mainly caused by lower open-circuit voltages (V(OC)s). Herein, the reasons for the low V-OC in inorganic CsPbI2Br perovskite solar cells are investigated. Intensity-dependent photoluminescence measurements for different layer stacks reveal that n-i-p and p-i-n CsPbI2Br solar cells exhibit a strong mismatch between quasi-Fermi level splitting (QFLS) and V-OC. Specifically, the CsPbI2Br p-i-n perovskite solar cell has a QFLS-e center dot V-OC mismatch of 179 meV, compared with 11 meV for a reference cell with an organic-inorganic perovskite of similar bandgap. On the other hand, this study shows that the CsPbI2Br films with a bandgap of 1.9 eV have a very low defect density, resulting in an efficiency potential of 20.3% with a MeO-2PACz hole-transporting layer and 20.8% on compact TiO2. Using ultraviolet photoelectron spectroscopy measurements, energy level misalignment is identified as a possible reason for the QFLS-e center dot V-OC mismatch and strategies for overcoming this V-OC limitation are discussed. This work highlights the need to control the interfacial energetics in inorganic perovskite solar cells, but also gives promise for high efficiencies once this issue is resolved.
Quantifying root water uptake is essential to understanding plant water use and responses to different environmental conditions. However, non-destructive measurement of water transport and related hydraulics in the soil-root system remains a challenge.
Neutron imaging, with its high sensitivity to hydrogen, has become an unparalleled tool to visualize and quantify root water uptake in vivo. In combination with isotopes (e.g., deuterated water) and a diffusion-convection model, root water uptake and hydraulic redistribution in root and soil can be quantified.
Here, we review recent advances in utilizing neutron imaging to visualize and quantify root water uptake, hydraulic redistribution in roots and soil, and root hydraulic properties of different plant species.
Under uniform soil moisture distributions, neutron radiographic studies have shown that water uptake was not uniform along the root and depended on both root type and age. For both tap (e.g., lupine [Lupinus albus L.]) and fibrous (e.g., maize [Zea mays L.]) root systems, water was mainly taken up through lateral roots. In mature maize, the location of water uptake shifted from seminal roots and their laterals to crown/nodal roots and their laterals.
Under non-uniform soil moisture distributions, part of the water taken up during the daytime maintained the growth of crown/nodal roots in the upper, drier soil layers. Ultra-fast neutron tomography provides new insights into 3D water movement in soil and roots. We discuss the limitations of using neutron imaging and propose future directions to utilize neutron imaging to advance our understanding of root water uptake and soil-root interactions.
Schools are key contexts for the development of adolescents' critical consciousness. We explored how three dimensions of the classroom cultural diversity climate (critical consciousness, color-evasion, and multiculturalism) related to adolescents' critical reflection (i.e., perceived societal Islamophobia) and intended critical action (i.e., political activism). Our sample included adolescents experiencing high (second generation, Muslim, N = 237) versus low (non-immigrant descent, non-Muslim, N = 478) stigmatization in Germany. Multilevel analyses revealed that for both groups a critical consciousness climate, but not a color-evasive or a multicultural climate, was positively associated with perceived societal Islamophobia and intended critical action. Thus, to promote adolescents' critical consciousness, schools should go beyond emphasizing a common humanity and celebrating cultural diversity and include explicit discussions of social inequity.
Ground motion with strong-velocity pulses can cause significant damage to buildings and structures at certain periods; hence, knowing the period and velocity amplitude of such pulses is critical for earthquake structural engineering.
However, the physical factors relating the scaling of pulse periods with magnitude are poorly understood.
In this study, we investigate moderate but damaging earthquakes (M-w 6-7) and characterize ground- motion pulses using the method of Shahi and Baker (2014) while considering the potential static-offset effects.
We confirm that the within-event variability of the pulses is large. The identified pulses in this study are mostly from strike-slip-like earthquakes. We further perform simulations using the freq uency-wavenumber algorithm to investigate the causes of the variability of the pulse periods within and between events for moderate strike-slip earthquakes.
We test the effect of fault dips, and the impact of the asperity locations and sizes. The simulations reveal that the asperity properties have a high impact on the pulse periods and amplitudes at nearby stations.
Our results emphasize the importance of asperity characteristics, in addition to earthquake magnitudes for the occurrence and properties of pulses produced by the forward directivity effect.
We finally quantify and discuss within- and between-event variabilities of pulse properties at short distances.
We consider an array of nearest-neighbor coupled nonlinear autonomous oscillators with quenched ran-dom frequencies and purely conservative coupling. We show that global phase-locked states emerge in finite lattices and study numerically their destruction. Upon change of model parameters, such states are found to become unstable with the generation of localized periodic and chaotic oscillations. For weak nonlinear frequency dispersion, metastability occur akin to the case of almost-conservative systems. We also compare the results with the phase-approximation in which the amplitude dynamics is adiabatically eliminated.
The Arctic is rich in aquatic systems and experiences rapid warming due to climate change. The accelerated warming causes permafrost thaw and the mobilization of organic carbon.
When dissolved organic carbon is mobilized, this DOC can be transported to aquatic systems and degraded in the water bodies and further downstream. Here, we analyze the influence of different landscape components on DOC concentrations and export in a small (6.45 km(2)) stream catchment in the Lena River Delta.
The catchment includes lakes and ponds, with the flow path from Pleistocene yedoma deposits across Holocene non-yedoma deposits to the river outlet. In addition to DOC concentrations, we use radiocarbon dating of DOC as well as stable oxygen and hydrogen isotopes (delta O-18 and delta D) to assess the origin of DOC.
We find significantly higher DOC concentrations in the Pleistocene yedoma area of the catchment compared to the Holocene non-yedoma area with medians of 5 and 4.5 mg L-1 (p < 0.05), respectively. When yedoma thaw streams with high DOC concentration reach a large yedoma thermokarst lake, we observe an abrupt decrease in DOC concentration, which we attribute to dilution and lake processes such as mineralization. The DOC ages in the large thermokarst lake (between 3,428 and 3,637 C-14 y BP) can be attributed to a mixing of mobilized old yedoma and Holocene carbon.
Further downstream after the large thermokarst lake, we find progressively younger DOC ages in the stream water to its mouth, paired with decreasing DOC concentrations. This process could result from dilution with leaching water from Holocene deposits and/or emission of ancient yedoma carbon to the atmosphere. Our study shows that thermokarst lakes and ponds may act as DOC filters, predominantly by diluting incoming waters of higher DOC concentrations or by re-mineralizing DOC to CO2 and CH4.
Nevertheless, our results also confirm that the small catchment still contributes DOC on the order of 1.2 kg km(-2) per day from a permafrost landscape with ice-rich yedoma deposits to the Lena River.
Microbe-mediated enzymatic hydrolysis of organic matter entails the production of hydrolysate, the recovery of which may be more or less efficient. The selfish uptake mechanism, recently discovered, allows microbes to hydrolyze polysaccharides and take up large oligomers, which are then degraded in the periplasmic space. By minimizing the hydrolysate loss, selfish behaviour may be profitable for free-living cells dwelling in a patchy substrate landscape. However, selfish uptake seems to be tailored to algal-derived polysaccharides, abundant in organic particles, suggesting that particle-attached microbes may use this strategy. We tracked selfish polysaccharides uptake in surface microbial communities of the northeastern Mediterranean Sea, linking the occurrence of this processing mode with microbial lifestyle. Additionally, we set up fluorescently labelled polysaccharides incubations supplying phytodetritus to investigate a 'pioneer' scenario for particle-attached microbes. Under both conditions, selfish behaviour was almost exclusively carried out by particle-attached microbes, suggesting that this mechanism may represent an advantage in the race for particle exploitation. Our findings shed light on the selfish potential of particle-attached microbes, suggesting multifaceted foraging strategies exerted by particle colonizers.
Same but different
(2022)
The peace processes in Liberia and Sierra Leone share similar contexts and have an interrelated history. They are also often portrayed as successful cases of peacebuilding. This conclusion seems valid, as war has not returned, and political power was handed over peacefully; however, both cases differ with regard to the inclusiveness of the peace processes and the role of local leaders. This article aims to add to the critical peacebuilding debate by focusing on local perceptions about the position of local leaders in these two peace processes. We conducted a public opinion survey in five regions in Sierra Leone and Liberia and expert interviews with peacebuilding actors to examine changing perceptions about the roles of local leaders in both countries. This article speaks to the broader peacebuilding debate by highlighting the importance of including local voices in the peace process and by discussing challenges of inclusive peacebuilding.
In which negotiation contexts are transitional justice provisions included in peace agreements? Today, many peace agreements include transitional justice provisions, but their inclusion differs based on conflict and negotiation characteristics. While context thus seems to be relevant for the choice of transitional justice provisions agreed on by the warring parties, very little is known about the context clusters that enable transitional justice. Using data on 58 full peace agreements signed between 1989 and 2018, a crisp-set Qualitative Comparative Analysis (QCA) investigates the combinations of conflict intensity, rebel group strength, type of conflict, third-party support and civil society participation that led to the inclusion of transitional justice provisions. The result of this exploratory study suggests four context settings that are identified as being empirically relevant for the inclusion of transitional justice provisions. Choices of justice are thus the result of an overall negotiation environment characterized by multiple interrelated context factors.
Reviewed Publications:
Garcia Manon. Wir werden nicht unterwürfig geboren. Wie das Patriarchat das Leben von Frauen bestimmt. Berlin: Suhrkamp, 2021, 235 S.
Hay Carol. Think like a Feminist. The Philosophy behind the Revolution. New York: W. W. Norton & Company, 2020, 222 S.
Manne Kate. Entitled. How Male Privilege Hurts Women. London: Allen Lane, 2020, 270 S.
Srinivasan Amia. The Right to Sex. London: Bloomsbury, 2021, 279 S.
Colloidal metal sulfide nanoparticles for high performance electrochemical energy storage systems
(2022)
Transition metal sulfides have emerged as excellent replacement candidates of traditional insertion electrode materials based on their conversion or alloying mechanisms, facilitating high specific capacity and rate ability. However, parasitic reactions such as massive volume change during the discharge/ charge processes, intermediate polysulfide dissolution, and passivating solid electrolyte interface formation have led to poor cyclability, hindering their feasibility and applicability in energy storage systems. Colloidal metal sulfide nanoparticles, a special class that integrates the intrinsic chemical properties of metal sulfides and their specified structural features, have fairly enlarged their contribution due to the synergistic effect. This review highlights the latest synthetic approaches based on colloidal process. Their corresponding electrochemical outcomes will also be discussed, which are thoroughly updated along with their insight scientific standpoints.
Consumers are increasingly demanding higher quality and safety standards for the products they consume, and one of this is wheat flour, the basis of a wide variety of processed products. This major component in the diet of many communities can be contaminated by microorganisms before the grain harvest, or during the grain storage right before processing. These microorganisms include several fungal species, many of which produce mycotoxins, secondary metabolites that can cause severe acute and chronic disorders. Yet, we still know little about the overall composition of fungal communities associated with wheat flour. In this study, we contribute to fill this gap by characterizing the fungal microbiome of different types of wheat flour using culture-dependent and -independent techniques. Qualitatively, these approaches suggested similar results, highlighting the presence of several fungal taxa able to produce mycotoxins. In-vitro isolation of fungal species suggest a higher frequency of Penicillium, while metabarcoding suggest a higher abundance of Alternaria. This discrepancy might reside on the targeted portion of the community (alive vs. overall) or in the specific features of each technique. Thus, this study shows that commercial wheat flour hosts a wide fungal diversity with several taxa potentially representing concerns for consumers, aspects that need more attention throughout the food production chain.
In Decolonizing Universalism: A Transnational Feminist Ethic zielt Serene Khader auf eine Neuausrichtung der feministischen Perspektive, welche es schafft, dekolonial und anti-imperialistisch zu sein, ohne gleichzeitig dem Universalismus komplett abzuschwören. Die Motivation hinter dieser Neuorientierung ist die Einsicht, dass der liberale moralische Universalismus oftmals kulturelle Vorherrschaft und Imperialismus verstärkt. In diesem Kommentar wollen wir (a) uns mit der Frage beschäftigen, was genau unter Geschlechtergerechtigkeit verstanden werden soll und welcher Maßstab zur Beantwortung der Frage nach Gerechtigkeit angebracht ist und (b) einige Ideen zum Unterschied zwischen idealer und nicht-idealer Theorie liefern.