Absence of remote earthquake triggering within the Coso and Salton Sea geothermal production fields

Geothermal areas are long recognized to be susceptible to remote earthquake triggering, probably due to the high seismicity rates and presence of geothermal fluids. However, anthropogenic injection and extraction activity may alter the stress state and fluid flow within the geothermal fields. Here we examine the remote triggering phenomena in the Coso geothermal field and its surrounding areas to assess possible anthropogenic effects. We find that triggered earthquakes are absent within the geothermal field but occur in the surrounding areas. Similar observation is also found in the Salton Sea geothermal field. We hypothesize that continuous geothermal operation has eliminated any significant differential pore pressure between fractures inside the geothermal field through flushing geothermal precipitations and sediments out of clogged fractures. To test this hypothesis, we analyze the pore-pressure-driven earthquake swarms, and they are found to occur outside or on the periphery of the geothermal production field. Therefore, our results suggest that the geothermal operation has changed the subsurface fracture network, and differential pore pressure is the primary controlling factor of remote triggering in geothermal fields

Atomic-Scale Investigation on the Ultra-large Bending Behaviours of Layered Sodium Titanate Nanowires

Study on mechanical properties of one-dimensional layered titanate nanomaterials is crucial since they demonstrate important applications in various fields. Here, we conducted ex situ and in situ atomic-scale investigation on bending properties of a kind of ceramic layered titanate (Na2Ti2O4(OH)2) nanowires in a transmission electron microscopy. The nanowires showed flexibility along direction and could obtain a maximum bending strain of nearly 37%. By analysing the defect behaviours, the unique bending properties of this ceramic material was found to correlate with a novel arrangement of dislocations, an accessible nucleation and movement along the axial direction resulting from the weak electrostatic interaction between the TiO6 layers and the low b/a ratio. These results provide pioneering and key understanding on bending behaviours of layered titanate nanowire families and potentially other one-dimensional nanomaterials with layered crystalline structures.Comment: 9 pages, 5 figure

A (Bi₂O₂)²⁺ layer as a significant carrier generator and transmission channel in CaBi₂Nb₂O₉ platelets for enhanced piezo-photo-catalytic performance

The low photocatalytic conversion efficiency, poor light absorption and high charge recombination rate of traditional semiconductor photocatalysts continues to be a significant research challenge. In this paper, by combining detailed experimental and modeling techniques, we report on the unique potential of CaBi2Nb2O9 (CBN) platelets that can couple both piezo- and photo- multi-field effects to overcome these issues and realize high-efficiency hydrogen production and dye degradation. The surface adsorption of OH− and dye molecules is improved as a result of the built-in electric field, thereby demonstrating an enhanced piezo- and photo-catalytic H2 production activity, with a high rate of 96.83 μmol g−1 h−1. The piezo-photocatalytic decomposition ratio for 100 mL RhB dye of 10 mg/L can reach up to 98.7 % in 32 min using only 0.05 mg of CBN platelets (k = 0.131 min−1). It is shown that the careful introduction of regularly arranged layers of (Bi2O2)2+ into the CBN platelet structure provides a high transport of photoelectrons via a pathway of (Bi2O2)2+ → (CaNb2O7)2− → CBN surface. The electron density distribution of Bi atoms is also found to be enriched on the facets of (020) and (200) crystal planes in the CBN platelets, which is beneficial to the oxidation reduction reaction. Furthermore, the large deformation of CBN platelet during the application of ultrasound leads to an increase of the piezo-induced built-in electric field to improve charge separation and migration. This work therefore provides a new perspective in the design and manufacture of advanced materials with enhanced piezo- and photo-catalytic performance by exploiting multi-field coupling effects.</p

Abnormal Voxel-Wise Degree Centrality in Patients With Late-Life Depression: A Resting-State Functional Magnetic Resonance Imaging Study.

Objectives:Late-life depression (LLD) has negative impacts on somatic, emotional and cognitive domains of the lives of patients. Elucidating the abnormality in the brain networks of LLD patients could help to strengthen the understanding of LLD pathophysiology, however, the studies exploring the spontaneous brain activity in LLD during the resting state remain limited. This study aimed at identifying the voxel-level whole-brain functional connectivity changes in LLD patients. Methods:Fifty patients with late-life depression (LLD) and 33 healthy controls were recruited. All participants underwent a resting-state functional magnetic resonance imaging scan to assess the voxel-wise degree centrality (DC) changes in the patients. Furthermore, DC was compared between two patient subgroups, the late-onset depression (LOD) and the early-onset depression (EOD). Results:Compared with the healthy controls, LLD patients showed increased DC in the inferior parietal lobule, parahippocampal gyrus, brainstem and cerebellum (p < 0.05, AlphaSim-corrected). LLD patients also showed decreased DC in the somatosensory and motor cortices and cerebellum (p < 0.05, AlphaSim-corrected). Compared with EOD patients, LOD patients showed increased centrality in the superior and middle temporal gyrus and decreased centrality in the occipital region (p < 0.05, AlphaSim-corrected). No significant correlation was found between the DC value and the symptom severity or disease duration in the patients after the correction for multiple comparisons. Conclusions:These findings indicate that the intrinsic abnormality of network centrality exists in a wide range of brain areas in LLD patients. LOD patients differ with EOD patients in cortical network centrality. Our study might help to strengthen the understanding of the pathophysiology of LLD and the potential neural substrates underlie related emotional and cognitive impairments observed in the patients

Population transcriptomes reveal synergistic responses of DNA polymorphism and RNA expression to extreme environments on the Qinghai-Tibetan Plateau in a predatory bird

Low oxygen and temperature pose key physiological challenges for endotherms living on the Qinghai–Tibetan Plateau (QTP). Molecular adaptations to high‐altitude living have been detected in the genomes of Tibetans, their domesticated animals and a few wild species, but the contribution of transcriptional variation to altitudinal adaptation remains to be determined. Here we studied a top QTP predator, the saker falcon, and analysed how the transcriptome has become modified to cope with the stresses of hypoxia and hypothermia. Using a hierarchical design to study saker populations inhabiting grassland, steppe/desert and highland across Eurasia, we found that the QTP population is already distinct despite having colonized the Plateau <2000 years ago. Selection signals are limited at the cDNA level, but of only seventeen genes identified, three function in hypoxia and four in immune response. Our results show a significant role for RNA transcription: 50% of upregulated transcription factors were related to hypoxia responses, differentiated modules were significantly enriched for oxygen transport, and importantly, divergent EPAS1 functional variants with a refined co‐expression network were identified. Conservative gene expression and relaxed immune gene variation may further reflect adaptation to hypothermia. Our results exemplify synergistic responses between DNA polymorphism and RNA expression diversity in coping with common stresses, underpinning the successful rapid colonization of a top predator onto the QTP. Importantly, molecular mechanisms underpinning highland adaptation involve relatively few genes, but are nonetheless more complex than previously thought and involve fine‐tuned transcriptional responses and genomic adaptation

Phosphorus adsorption and desorption characteristics and its response to soil properties of black soil under long-term different fertilization

editorial reviewedObjective: Fertilizer is generally added to agricultural soil to meet the needs of crop production, but long-term over fertilization changes soil phosphorus (P) pool and soil properties. This study evaluated the characteristics change of P adsorption and desorption and its response to soil properties under long-term fertilization, to do a favor to provide theoretical basis of rational fertilizer application and improve the P availability of black soil. Method: Four treatments, including no fertilizer (CK), urea and potash sulphate (NK), urea, super-calcium phosphate and potash sulphate (NPK), and NPK plus pig manure (NPKM), were investigated in a 21-year (1989-2010) long-term fertilization experiment at Gongzhuling (Jilin Province) of China. The crop of cropping system was maize. Soil samples were collected in 1990, 2000 and 2010 at 0-20 cm depth to analyze soil properties and to measure soil P adsorption and desorption characteristics. Langmuir equation was used to fit the P adsorption curve, and then the maximum adsorption capacity (Qmax), adsorption constant (K), buffering capacity of soil P (MBC), and P sorption saturation (DPS) were calculated according to Langmuir equation. Result: There was a good fitness between the P adsorption curve and Langmuir equation (R2=0.93-0.99, P<0.01). There existed difference for P adsorption and desorption characteristic under the four treatments. Over time, compared with initial year, for CK and NK treatments, the Qmax value increased by 1.83 and 1.61 times, MBC value increased by 0.80% and 49.40%, DPS value decreased by 92.04% and 87.50%, Readily Desorbable Phosphorus (RDP) value decreased by 20.00% and 82.83%, respectively; for NPK treatment, Qmax and DPS value increased by 81.87% and 79.56%, MBC and RDP value decreased by 79.37% and 48.57%, respectively, while under NPKM treatment, the Qmax and MBC value decreased by 33.35% and 78.52%, DPS and RDP values increased by 11.36 and 1.48 times, respectively. After 21 years experiments, compared with CK and NPK treatments, the Qmax and MBC value of NPKM treatment decreased by 64.66% and 49.52%, 81.87% and 79.56%, respectively; the DPS and RDP value of NPKM treatment increased by 110 and 3.81 times, 4.36 times and 78.57%, respectively. Compared with other treatments, the Total-P, Olsen-P, soil organic matter (SOM) and CaCO3 contents increased and SSA decreased significantly, but the pH, free Fe2O3 and Al2O3 value kept unchanged under NPKM treatment. RDA test showed that SOM and Total-P were the main factors that explained 49.5% and 18.7% of the total variation (P<0.05) which caused the difference of P adsorption desorption characteristic parameters among four treatments. Conclusion: Long-term combination of NPK fertilizers with manures could significantly increase SOM and P accumulation contents, decrease the soil adsorption capacity and increase desorption capacity, and improve P availability in soil, but it significantly increased the DPS value, easily thereby caused the risk of phosphorus loss. Therefore, various management practices and inorganic and organic P fertilizer input amounts should be considered to reduce P losses from this area

A CRM1 Inhibitor Alleviates Cardiac Hypertrophy and Increases the Nuclear Distribution of NT-PGC-1α in NRVMs

Chromosomal maintenance 1 (CRM1) inhibitors display antihypertrophic effects and control protein trafficking between the nucleus and the cytoplasm. PGC-1α (peroxisome proliferator-activated receptor gamma coactivator-1alpha) is a type of transcriptional coactivator that predominantly resides in the nucleus and is downregulated during heart failure. NT-PGC-1α is an alternative splicing variant of PGC-1α that is primarily distributed in the cytoplasm. We hypothesized that the use of a CRM1 inhibitor could shuttle NT-PGC-1α into the nucleus and activate PGC-1α target genes to potentially improve cardiac function in a mouse model of myocardial infarction (MI). We showed that PGC-1α and NT-PGC-1α were decreased in MI-induced heart failure mice. Phenylephrine and angiotensin II were applied to induce hypertrophy in neonatal rat ventricular myocytes (NRVMs). The antihypertrophic effects of the CRM1-inhibitor Selinexor was verified through profiling the expression of β-MHC and through visualizing the cell cross-sectional area. NRVMs were transfected with adenovirus-NT-PGC-1α or adenovirus-NLS (nucleus localization sequence)-NT-PGC-1α and then exposed to Selinexor. Confocal microscopy was then used to observe the shuttling of NT-PGC-1α. After NT-PGC-1α was shuttled into the nucleus, there was increased expression of its related genes, including PPAR-α, Tfam, ERR-γ, CPT1b, PDK4, and Nrf2. The effects of Selinexor on post-MI C57BL/6j mice were determined by echocardiography and qPCR. We found that Selinexor showed antihypertrophic effects but did not influence the ejection fraction of MI-mice. Interestingly, the antihypertrophic effects of Selinexor might be independent of NT-PGC-1α transportation