Deep Transition Research Articles

Modeling Infrared Spectroscopy of Nucleic Acids: Integrating Vibrational Non-Condon Effects with Machine Learning Schemes.

Vibrational non-Condon effects, which describe how molecular vibrational transitions are influenced by a system's rotational and translational degrees of freedom, are often overlooked in spectroscopy studies of biological macromolecules. In this work, we explore these effects in the modeling of infrared (IR) spectra for nucleic acids in the 1600-1800 cm-1 region. Through electronic structure calculations, we reveal that the transition dipole moments of the C═O and C═C stretching modes in nucleobases are highly sensitive to solvation, hydrogen bonding, and base stacking conditions. To incorporate vibrational non-Condon effects into spectroscopy modeling, we use local electric fields on chromophore atoms as collective coordinates and leverage experimental IR spectra of oligonucleotides to develop deep neural network-based transition dipole strength (TDS) maps for the C═O and C═C chromophores. By integrating molecular dynamics simulations with a mixed quantum/classical treatment of the line shape theory, we apply the TDS maps to calculate the IR spectra of nucleoside 5'-monophosphates, DNA double helices and yeast phenylalanine tRNA. The resulting theoretical spectra show quantitative agreement with experimental measurements. While the predictions for nucleoside 5'-monophosphates are comparable to baseline performance, the TDS maps yield significantly improved IR peak intensities across all oligonucleotides. This theoretical framework effectively bridges atomistic simulations and IR spectroscopy experiments, offering molecular insights into how vibrational non-Condon effects impact the observed spectral features.

Hybrid Density Functional Study on the p-Type Conductivity Mechanism in Intrinsic Point Defects and Group V Element-Doped 2D β-TeO2.

The newly discovered two-dimensional (2D) β-TeO2 possesses extraordinarily high p-type carrier mobility and demonstrates immense potential in the electronics field. However, current research on its p-type conductivity mechanisms and the modifications of element doping remains relatively insufficient. In this study, the intrinsic point defects and extrinsic element doping in monolayer β-TeO2 are comprehensively analyzed to probe the potential sources of the intrinsic p-type conductivity and the extrinsic p-type doping possibility in 2D β-TeO2 through hybrid density functional calculations. Our results reveal that the vacancy defects with low formation energies have deep transition levels and thus cannot be used as sources of unintentional p-type conductivity in 2D β-TeO2. The investigations and discussions via Group V element doping modifications in 2D β-TeO2 indicate that bismuth (Bi) doping can easily and significantly enhance the p-type conductivity of 2D β-TeO2 under the presence of O-rich, which can be achieved experimentally. Furthermore, Bi doping can significantly increase carrier mobility without seriously affecting the electronic structure. The finding shows that the Bi element is an ideal dopant candidate for a p-type modification in 2D β-TeO2. Our calculations pave an alternative strategy to achieve the realization of superior p-type conductivity in 2D β-TeO2.

Place-based and sectoral patterns in urban experimentation: Implications for deep transitions research

Transforming critical infrastructure systems, such as water and energy, is crucial to achieving global sustainability and climate change targets in many cities. Whilst experimentation has been studied extensively in urban sustainability scholarships, there have been no large-N cross-sector comparative studies. Existing research is potentially blind to different patterns of urban experiments across multiple sectors. This is particularly relevant to advancing deep transitions thinking, which has increasingly foregrounded the notion of multi-system alignment across socio-technical domains. Our research aims to fill this knowledge gap using a database to characterise urban experiments across water and energy domains while integrating sectoral and place-based perspectives. We analysed 40 experiments across Melbourne and Adelaide, Australia. Our results show that on a collective level, these experiments skew towards technological interventions, while their transfer and impact trajectories are underpinned by distinct territorial and sectoral logics. We show that cross-sectoral analysis can reveal plurality in urban experiments across multiple systems and places while offering a more refined understanding of multi-system alignment requirements for deep transitions.

Electrical conduction and optical characteristics of Li2O and Bi2O3 Co-doped zinc-phosphate glassy nanocomposites: A critical observation of mixed ionic electronic effect

In the present report, the combined effects of the co-doping of metal oxide (Bi2O3) and Lithium oxide (Li2O) into the glassy matrix with chemical composition xLi2O-(0.45-x)Bi2O3-(0.15ZnO-0.40P2O5) (x = 0.05, 0.15, 025, and 0.35 mol%) are investigated thoroughly. The FESEM and X-ray diffraction data affirm the crystalline nature of the studied glassy composites. The obtained band gap energy values are declined from (3.68–3.17) eV, while the Urbach energy values are declined from (0.38–0.27) eV. Moreover, the mechanism responsible for AC conductivity has been analyzed using Almond–West formalism and Jonscher's universal power law. The observed rise in both AC and DC conductivity in the glass samples is attributed to the mixed ionic electronic effect. In the ionic diffusion model, an increased defect site concentration improves Li+ ion migration through percolation channels. The reduction in both electrostatic binding energy and strain energy lowers the Anderson-Stuart activation energy, facilitating Li+ ion migration and enhancing conductivity. Additionally, in the small polaron hopping model, an increase in the density of defect states suggests more defect sites that facilitate electronic hopping, creating deep localized states and transitions between localized and extended states. Replacing a Bismuth atom with a Lithium atom increases the number of non-bridging oxygen, enhancing the conduction band tail, reducing the energy needed for hopping conductivity, and increasing conductivity.

Roles of defects in perovskite CsPbX3 (X=I, Br, Cl): a first- principles investigation

Inorganic lead halide perovskite CsPbX3 (X=I, Br, Cl) have a promising application in optoelectronic fields due to their excellent photovoltaic properties. The defects, which have a significant impact on the performance of materials, are often introduced during the synthesis process. However, there is still a lack of systematic theoretical investigation of the effects of these defects. In this study, the effects of vacancies and H-atom interstitial point defects on the structural, electronic and optical properties of CsPbX3 are systematically investigated by using first-principles approach based on density-functional theory. The calculated results show that the introduction of different defects have significantly effect on the band gap, effective mass, semiconductor properties, ion migration and optical absorption coefficient of the perovskite materials. It is also found that VCs and VPb defects introduce shallow transition levels that do not negatively impact the optoelectronic properties. However, VX and interstitial H defects generate deep transition levels within the bandgap, which acts as non-radiative recombination centers and reduce the optoelectronic performance of the perovskite material. This study contributes to the understanding of the nature of halide chalcogenides and optimally regulating the performance of optoelectronic devices.

Locating Boundaries Between Locked and Creeping Regions at Nankai and Cascadia Subduction Zones

AbstractInterseismic coupling maps and, especially, estimates of the location of the fully coupled (locked) zone relative to the trench, coastline, and slow slip events are crucial for determining megathrust earthquake hazard at subduction zones. We present an interseismic coupling inversion that estimates the locations of the upper and lower boundaries of the locked zone, the lower boundary of the deep transition zone, and downdip gradient of creep rate in the transition from locked to freely creeping in the downdip transition zone. We show that the locked zone at Cascadia is west of the coastline and 10 km updip of the slow slip zone along much of the margin, widest (25–125 km, extending to ∼19 km depth) in northern Cascadia, narrowest (0–70 km) in central Cascadia, with moment accumulation rate equivalent to a Mw 8.71 and Mw 8.85 earthquake for 300‐ and 500‐year earthquake cycles. We find a steep gradient in creep immediately below the locked zone, indicative of propagating creep, along the entire margin. At Nankai, we find three distinct zones of locking (offshore Shikoku, offshore southeast Kii peninsula, and offshore Shima peninsula) with a total moment accumulation rate equivalent to a Mw 8.70 earthquake for a 150‐year earthquake cycle. The bottom of the locked zone is nearly under the coastline for all three locked regions at Nankai and is positioned 0–5 km updip of the slow slip zone. In contrast with Cascadia, creep rate gradients below the locked zone at Nankai are generally gradual, consistent with stationary locking.

Досвід прогнозування ризиків, пов’язаних з механічним пошкодженням кісткової тканини людини з використанням рекурентних нейронних мереж

Introduction. There are new, in addition to probabilistic and statistical, methods of risk assessment, which require their own methods of analysis and numerical estimation. One of these methods, recognized in a variety of application fields, is associated with the use of direct propagation neural networks. This approach makes it possible to expand the range of tasks that are solved in the field of risk analysis. There are quite a number of systems that require assessment in terms of risk formation, but which are associated with a large number of random factors related to the risk-forming events of the system and its states. Such systems are difficult to model with the help of well-known neural networks. Within the framework of the work, it is proposed to use the capabilities of deep recurrent neural networks with feedback as stabilizing factors with minimization of operational information that needs to be remembered in the process of calculating and operating such a network. Such a model for mechanical damage to human bone tissue depending on a large number of random or indeterminate input signals is proposed to be used in this work. The purpose of the paper is to develop a technique for the use of deep recurrent neural networks and to create a model for predicting event risks associated with the impact of input signals with a high degree of uncertainty or random signals on the system. To provide opportunities for predicting such risks using examples related to injuries of the human skeletal system for its various conditions and conditions. Results. A technique for using recurrent neural networks to predict the risks associated with the violation of the integrity of the human skeletal system was developed. A model of a recurrent neural network was created to predict random events associated with a violation of the integrity of the human skeletal system. Double calculation, aimed at a variety of results, is a confirmation of the performance of the proposed model. It is shown that, depending on the scope of the task set in the analysis, its result is a three-dimensional matrix in coordinates (Xij ∧ Yp;T; φ). At each subsequent step of the iteration in the matrix (φ Xij ∧ Yp;T), by cutting off that part of the potential risk-generating events that, in the opinion of the neural network, are less predicted for each age composition, in favor of other events, real risk-forming events are filtered out, which have predominant values for the system. Conclusions. On the example of random events that accompany mechanical damage to human bone tissue, the ability of models created on the basis of RNN with feedbacks to avoid the uncertainty of risks accompanying human life in four specified ranges of life time and to determine the most effective ones for each of them for a modern person is shown. The ability of activation functions of the bifurcation nature of one of the synapse layers to qualitatively filter random signals in systems of recurrent neural networks with DT-RNN (Deep Transition RNN) feedbacks is shown. The use of deep recurrent neural networks in the formalized version provides new opportunities for taking into account groups of random but real events in the analysis of event risk by clarifying the feedback, and at each subsequent step of their iteration to obtain more accurate data to predict such risk, avoiding the uncertainty of the system state. The formalization of this process provides opportunities to predict random risks for certain groups of the population as a priority, and to use them in the preventive work of medical institutions of the first group of care. Keywords: risks, random events, recurrent neural network, human skeletal system.

Tax Challenges Arising from Digitalization: Evaluating the Taxation Models Proposed by the European Commission and the OECD

The world has entered a period of deep transition with rapid and phenomenal development of innovations. The rise of the digital economy has dramatically changed the global business environment, creating new challenges for the tax system. Newspapers and magazines are being replaced by the Internet, and trade in material goods – by digital services. The digital economy eliminates the barriers of time, space and distance. The server where the transaction is processed, the location from which the goods or services are supplied and the place of supply of such goods or services are in different jurisdictions, therefore, the question “Where should the transaction be taxed?” is raised. Meanwhile, the digital economy opens up unprecedented opportunities to avoid taxes with the international tax rules which are still “stuck” in 20th-century business concepts, because the companies operating in the digital space do not need factories, stores or other permanent residences to develop their activities. This article aims to evaluate the efforts of the European Union and international standard-setting entities to find a solution for fair taxation of the digital economy. The first part of the article delves into the concept of the digital economy and its essential features with a special emphasis on the role of the digital service user which is unique and more complex than the role usually played by the customer. This part also analyses the differences between digital and traditional business. The second part of the study emphasizes the reasons that will lead to the necessity of taxation of the digital economy, discusses the digital services tax applied in certain countries of the European Union and highlights the weakness of the concept of digital establishment in double taxation agreements concluded by the countries. The final part explores the proposals submitted by the European Commission regarding the introduction of a common consolidated corporate tax base and the inclusion of the concept of virtual permanent establishment in the tax system in the context of the digital economy taxation model proposed by international organizations.

Chrome incorporation in high-pressure Fe–Mg oxides

Abstract. The occurrence of Cr-bearing oxide phases as inclusions in diamonds and in extraterrestrial materials has the potential to serve as an indicator of formation conditions. However, such an application requires detailed knowledge of phase stabilities and the influence that Cr may have on its stability. To this end, the incorporation of Cr in high-pressure post-spinel Fe–Mg oxide phases was experimentally investigated at pressures of 14–22 GPa and temperatures between 1100 and 1600 °C using a multi-anvil press. We find that neither the Fe3Cr2O6 nor the Mg3Cr2O6 endmember composition is stable over the expected range of pressure and temperature where Fe5O6 itself is known to be stable. Further experiments along the Fe32+Fe23+O6–Fe32+Cr2O6 binary indicate only small amounts of Cr substitution are possible: ∼ 0.12 cations Cr per formula unit or ∼ 6 mol % Fe32+Cr2O6 component. In contrast, complete solid solution is apparent across both the Fe22+(Cr,Fe3+)2O5 and the Mg2(Cr,Fe3+)2O5 binaries, and there are indications of complete solution in the entire (Mg,Fe2+)2(Cr,Fe3+)2O5 quaternary system. The O5-structured phase usually coexists with (Fe,Mg)O. At 16–20 GPa, a post-spinel phase with O4 stoichiometry was occasionally encountered, having either a modified Ca-ferrite- (mCF-FeCr2O4) or a Ca-titanate-type (CT-MgCr2O4) structure. In one high-temperature experiment at 1600 °C, an unquenchable Mg-rich phase with a reconstructed Mg4Fe23+O7 stoichiometry occurred together with Mg2(Cr,Fe3+)2O5. In one experiment at 1100 °C and 16 GPa with a bulk composition of Mg2(Cr0.6,Fe0.43+)2O5, an assemblage of O5 phase + eskolaite–hematite solid solution + periclase was obtained together with minor amounts of the CT-type phase and a β-(Cr,Fe)OOH phase. The occurrence of these two minor phases in this low-temperature experiment is an indicator of variable reaction kinetics amongst the starting materials, which caused chemical heterogeneities to develop at the onset of the experiment. The structural systematics of Fe22+(Cr,Fe3+)2O5 and (Fe2+,Mg)2(Cr,Fe3+)2O5 solid solutions were investigated. It is notable that the Fe3+ and Cr endmembers have somewhat different crystal structures, belonging to space groups Cmcm (no. 63) and Pbam (no. 55), respectively. The phase transition occurs around the midpoint of the Fe3+–Cr joins. In spite of complexities in the behavior of the unit-cell parameters, the variation in molar volume with composition deviates only slightly from linearity. Wüstite and periclase coexisting in our experiments reveal the incorporation of up to 9 wt % and 25 wt % Cr2O3, respectively. This is consistent with the minor Cr contents reported for some ferropericlase inclusions in natural diamond. The limited solubility of other cations in Fe5O6 limits the likelihood of it being an accessory phase in the Earth's deep upper mantle and transition zone, except in Fe-rich environments. In contrast, the O5 phase appears to be more flexible in accommodating a range of divalent and trivalent cations, suggesting that this phase is more likely to be stabilized, potentially where redox reactions related to diamond formation occur.

Deep learning-based public transit passenger flow prediction model: integration of weather and temporal attributes

Deep learning-based public transit passenger flow prediction model: integration of weather and temporal attributes

Deep Learning-Based Real-Time Organ Localization and Transit Time Estimation in Wireless Capsule Endoscopy.

Wireless capsule endoscopy (WCE) has significantly advanced the diagnosis of gastrointestinal (GI) diseases by allowing for the non-invasive visualization of the entire small intestine. However, machine learning-based methods for organ classification in WCE often rely on color information, leading to decreased performance when obstacles such as food debris are present. This study proposes a novel model that integrates convolutional neural networks (CNNs) and long short-term memory (LSTM) networks to analyze multiple frames and incorporate temporal information, ensuring that it performs well even when visual information is limited. We collected data from 126 patients using PillCam™ SB3 (Medtronic, Minneapolis, MN, USA), which comprised 2,395,932 images. Our deep learning model was trained to identify organs (stomach, small intestine, and colon) using data from 44 training and 10 validation cases. We applied calibration using a Gaussian filter to enhance the accuracy of detecting organ boundaries. Additionally, we estimated the transit time of the capsule in the gastric and small intestine regions using a combination of a convolutional neural network (CNN) and a long short-term memory (LSTM) designed to be aware of the sequence information of continuous videos. Finally, we evaluated the model's performance using WCE videos from 72 patients. Our model demonstrated high performance in organ classification, achieving an accuracy, sensitivity, and specificity of over 95% for each organ (stomach, small intestine, and colon), with an overall accuracy and F1-score of 97.1%. The Matthews Correlation Coefficient (MCC) and Geometric Mean (G-mean) were used to evaluate the model's performance on imbalanced datasets, achieving MCC values of 0.93 for the stomach, 0.91 for the small intestine, and 0.94 for the colon, and G-mean values of 0.96 for the stomach, 0.95 for the small intestine, and 0.97 for the colon. Regarding the estimation of gastric and small intestine transit times, the mean time differences between the model predictions and ground truth were 4.3 ± 9.7 min for the stomach and 24.7 ± 33.8 min for the small intestine. Notably, the model's predictions for gastric transit times were within 15 min of the ground truth for 95.8% of the test dataset (69 out of 72 cases). The proposed model shows overall superior performance compared to a model using only CNN. The combination of CNN and LSTM proves to be both accurate and clinically effective for organ classification and transit time estimation in WCE. Our model's ability to integrate temporal information allows it to maintain high performance even in challenging conditions where color information alone is insufficient. Including MCC and G-mean metrics further validates the robustness of our approach in handling imbalanced datasets. These findings suggest that the proposed method can significantly improve the diagnostic accuracy and efficiency of WCE, making it a valuable tool in clinical practice for diagnosing and managing GI diseases.

Microfluidic jet impacts on deep pools transition from capillary-dominated cavity closure to gas pressure-dominated closure at higher Weber numbers.

Studying liquid jet impacts on a liquid pool is crucial for various engineering and environmental applications. During jet impact, the free surface of the pool deforms and a cavity is generated. Simultaneously, the free surface of the cavity extends radially outward and forms a rim. Eventually the cavity collapses by means of gas inertia and surface tension. Our numerical investigation using an axisymmetric model in Basilisk C explores cavity collapse dynamics under different impact velocities and gas densities. We validate our model against theory and experiments across a previously unexplored parameter range. Our results show two distinct regimes in the cavity collapse mechanism. By considering forces pulling along the interface, we derive scaling arguments for the time of closure and maximum radius of the cavity, based on the Weber number. For jets with uniform constant velocity from tip to tail and We ⩽ 150 the cavity closure is capillary dominated and happens below the surface (deep seal). In contrast, for We ⩾ 180 the cavity closure happens above the surface (surface seal) and is dominated by the gas entrainment and the pressure gradient that it causes. Additionally, we monitor gas velocity and pressure throughout the impact process. This analysis reveals three critical moments of maximum gas velocity: before impact, at the instant of cavity collapse, and during droplet ejection following cavity collapse. Our results provide information for understanding pollutant transport during droplet impacts on large bodies of water, and other engineering applications, like additive manufacturing, lithography and needle-free injections.

Aero-ZnS prepared by physical vapor transport on three-dimensional networks of sacrificial ZnO microtetrapods.

Aeromaterials represent a class of increasingly attractive materials for various applications. Among them, aero-ZnS has been produced by hydride vapor phase epitaxy on sacrificial ZnO templates consisting of networks of microtetrapods and has been proposed for microfluidic applications. In this paper, a cost-effective technological approach is proposed for the fabrication of aero-ZnS by using physical vapor transport with Sn2S3 crystals and networks of ZnO microtetrapods as precursors. The morphology of the produced material is investigated by scanning electron microscopy (SEM), while its crystalline and optical qualities are assessed by X-ray diffraction (XRD) analysis and photoluminescence (PL) spectroscopy, respectively. We demonstrate possibilities for controlling the composition and the crystallographic phase content of the prepared aerogels by the duration of the technological procedure. A scheme of deep energy levels and electronic transitions in the ZnS skeleton of the aeromaterial was deduced from the PL analysis, suggesting that the produced aerogel is a potential candidate for photocatalytic and sensor applications.

Synergistic emission reductions and health effects of energy transitions under carbon neutrality target

China's climate and environmental problems remained prominent. Energy transition was the key to improve climate and pollution, and it was at a critical period. Previous studies mostly focused on the impact of climate policies on the reduction of air pollutants and the environmental health impacts of individual sector or pathway policies. Thus, focusing on the synergistic abatement of CO2 and air pollutants and health effects of energy transition in carbon neutrality was significant for building beautiful and healthy China. LEAP-HEA model was constructed to project energy demand, CO2 and air pollutants, and assess energy transition's environmental health effects from 2020 to 2060. LMDI model was adopted to decompose the abatement contribution. Synergistic assessment index was used to estimate the coordinated abatement effects. Cost-effectiveness of energy transition and regional heterogeneity of PM2.5 toxicity were not considered. The results indicated: (1) energy demand would decrease and structure would be optimized significantly under deep energy transition scenario. (2) Deep energy transition could promote earlier realization of carbon neutrality. It would contribute significantly to CO2 and air pollutants abatement with strong synergistic effects. (3) Energy transition would reduce health risks with large economic benefits. Recommendations were proposed based on the conclusions.

The formation of transiting circumplanetary debris discs from the disruption of satellite systems during planet–planet scattering

Abstract Several stars show deep transits consistent with discs of roughly 1 R⊙ seen at moderate inclinations, likely surrounding planets on eccentric orbits. We show that this configuration arises naturally as a result of planet–planet scattering when the planets possess satellite systems. Planet–planet scattering explains the orbital eccentricities of the discs’ host bodies, while the close encounters during scattering lead to the exchange of satellites between planets and/or their destabilisation. This leads to collisions between satellites and their tidal disruption close to the planet. Both of these events lead to large quantities of debris being produced, which in time will settle into a disc such as those observed. The mass of debris required is comparable to a Ceres-sized satellite. Through N-body simulations of planets with clones of the Galilean satellite system undergoing scattering, we show that 90 % of planets undergoing scattering will possess debris from satellite destruction. Extrapolating to smaller numbers of satellites suggests that tens of percent of such planets should still possess circumplanetary debris discs. The debris trails arising from these events are often tilted at tens of degrees to the planetary orbit, consistent with the inclinations of the observed discs. Disruption of satellite systems during scattering thus simultaneously explains the existence of debris, the tilt of the discs, and the eccentricity of the planets they orbit.

Investigation of carbon-related complexes in highly C-doped GaN grown by metalorganic vapor phase epitaxy

We investigated the C-related complexes in highly C-doped GaN by electron spin resonance (ESR) spectroscopy, Fourier transform IR spectroscopy (FTIR), and minority carrier transient spectroscopy (MCTS) measurements. In the ESR spectra, two resonances with g values of 2.02 and 2.04 were found to be assigned by (0/−) deep acceptor and (+/0) charge transition levels of carbon substituting for nitrogen site (CN). In the FTIR spectra, two local vibrational modes positioned at 1679 and 1718 cm−1 were confirmed to be associated with tri-carbon complexes of CN–CGa–CN (basal) and CN–CGa–CN (axial), respectively. In the MCTS spectra, we observed the hole trap level of E v + 0.25 ± 0.1 eV associated with the tri-carbon complexes, which are the dominant C-related defects, suggesting that these complexes affect the electronic properties in the highly C-doped GaN.

Native point defects in HgCdTe infrared detector material: Identifying deep centers from first principles

We investigate the native point defects in the long-wavelength infrared (LWIR) detector material Hg0.75Cd0.25Te using a dielectric-dependent hybrid density functional combined with spin–orbit coupling. Characterizing these point defects is essential as they are responsible for intrinsic doping and nonradiative recombination centers in the detector material. The dielectric-dependent hybrid functional allows for an accurate description of the bandgap (Eg) for Hg1−xCdxTe (MCT) over the entire compositional range, a level of accuracy challenging with standard hybrid functionals. Our comprehensive examination of the native point defects confirms that cation vacancies VHg(Cd) are the primary sources of p-type conductivity in the LWIR material given their low defect formation energies and the presence of a shallow acceptor level (−/0) near the valence-band maximum. In addition to the shallow acceptor level, the cation vacancies exhibit a deep charge transition level (2−/−) situated near the midgap, characteristic of nonradiative recombination centers. Our results indicate that Hg interstitial could also be a deep center in the LWIR MCT through a metastable configuration under the Hg-rich growth conditions. While an isolated Te antisite does not show deep levels, the formation of VHg–TeHg defect complex introduces a deep acceptor level within the bandgap.

Electron-Phonon Coupling-Mediated Ultralong Carrier Lifetime in an All-Inorganic Two-Dimensional Cs2PbI2Cl2 Perovskite: Explanation for the High Antisite Defect Tolerance.

Two-dimensional (2D) halide perovskite are appealing candidates for applications in optoelectronics and photovoltaics, but their energy conversion efficiency is severely limited by nonradiative electron-hole recombination. In most investigations, point defects with deep defect levels and deep charge-state transition levels in the band gap are treated as the carrier recombination centers. For the all-inorganic 2D Css 2PbI2Cl2, the IPb antisite defect is the most likely to form and cause nonradiative electron-hole recombination. By using density functional theory and ab initio nonradiative molecular dynamics calculations, we found that the IPb defect can introduce the deep acceptor and donor levels into the band gap. Because electron-phonon coupling gives rise to weak nonadiabatic coupling and rapid loss of electronic coherence, those levels lead to a reduction of the carrier loss and the prolongation of the excited-state carrier lifetime, thereby enhancing the photoelectric and defect tolerance properties of the Cs2PbI2Cl2 material. These results could deepen the understanding of the chemistry of defects and carrier dynamics in perovskite materials.

Managed competition in Colombia: convergence of public and private insurance and delivery.

The Colombian health system has made a deep transition into managed competition since a major reform in 1993. A market for insurers was created, the consumer has free choice of insurer and a national-level equalisation fund distributes revenues via a per-capita payment. Fully subsidised insurance for the poor and informal, and a comprehensive standardised benefit package for subsidised and contributory schemes (both schemes covering 98 per cent of the population), has led to a low level of out-of-pocket expenses and high financial protection, as well as to reduced gaps in equity in access. The preconditions for managed competition are largely met, but improving health care providers' organisation towards integrated care, to enable them to deliver more value, is a necessary step to achieve the expected results of managed competition in terms of efficiency and quality. Although the current system is likely to be reformed in the coming months, the nature and extent of those reforms are not defined yet, so our analysis is based on the current system.

Heat flow and thermal structure in the Koyna seismic zone, western India: Implications for recurrent reservoir triggered seismicity

Scientific core drilling to a depth of 1522 m in the Koyna seismic zone, western India, provides a rare opportunity to characterize the geothermal regime and study its implications on seismogenesis. The borehole KBH-1 penetrated the 932.5 m thick Deccan Trap and continued for 589.5 m in the granite-gneiss basement. The equilibrium temperature profile was obtained from measurements made 10 months after drilling. Thermal conductivity was measured on core samples of Deccan basalt and basement granitoids. Radiogenic heat production of the basement granitoids was estimated from U, Th and K analyses. Salient results are as follows. (i) The temperature gradients in Deccan basalt and granite-gneiss basement, 26.5 mKm−1 and 15.7 mKm−1, respectively, combined with thermal conductivity measurements for the two rock types, yield a mean heat flow of 43 mW m−2. (ii) The low heat flow in Koyna is similar to values characteristic of Archaean cratons. (iii) Mean Th concentration of 6.8 ppm, U 0.9 ppm, and K 1.8% yielded a mean radiogenic heat production of 0.9 μWm−3 for the basement granitoids. (iv) New geological and geothermal constraints lead to improved estimates of temperature in the crust. Although geothermal considerations support a ∼ 25 km deep seismic-aseismic transition, the seismic activity is limited to the uppermost 10 km. (v) The infrequent occurrence of earthquakes below ∼10 km could be attributed to the low permeability of the basement granitoids, which reduces the influence of pore fluids in triggering failures along faults at deeper levels.