Local origins of interdecadal Pacific variability in the tropical and North Pacific Ocean: evidence from a comparative study of coral oxygen isotope records

Interdecadal Pacific variability (IPV) is commonly observed in both the tropical and mid-latitude Pacific Ocean, and has a widespread influence on surface climate in the Pan- Pacific Basin. This variability is recorded by climate proxies such as geochemical parameters preserved in corals. However, the origins of IPV remain uncertain. To shed light on this, interdecadal variations in two long coral δO records from Nauru Island and the South China Sea (SCS), respectively located in the tropical Pacific and the mid-latitude North Pacific Ocean, were investigated. The interdecadal fluctuations in the δO series from Nauru Island (tropical Pacific) match those of the NINO3.4 index reasonably well (r=–0.30, n=96, p=0.0015), but are not correlated with those of the Pacific decadal oscillation (PDO) index (r=–0.17, n=96, p=0.05). The δO time series from the SCS (northwestern Pacific), by contrast, co-vary with the PDO index (r=–0.30, n=156, p=0.0007), but are out of phase with the NINO3.4 index at the interdecadal timescale (r=0.04, n=156, p=0.31). The impact on the interdecadal variability of processes occurring outside the growth region of corals is generally weak. The results thus do not support a tropical origin of IPV, but demonstrate that the interdecadal variability in the tropical Pacific and the North Pacific originates predominantly from local coupled ocean–atmosphere processes within these regions. The results also suggest that tropical–extratropical interactions played a role in IPV between 1920 and 1940, which indicates that IPV is a complex climatic phenomenon that involves multiple forcing mechanisms

Comparative perspective on collective ownership and land distribution in China

Die Frage des Grundbesitzes ist sehr wichtig für die Entwicklung der chinesischen Landwirtschaft. Die vorliegende Arbeit befasst sich mit der Frage des Grundbesitzes in China und fragt, ob die Privatisierung des chinesischen Gemeineigentums eine Lösung sein könnte. Der erste Teil führt in das Thema ein und erklärt den theoretischen Rahmen – die bäuerliche „Gegenaktion“. Er umfasst auch eine kurze Beschreibung des aktuellen Forschungsstandes und eine Abgrenzung des Gegenstands der Diskussion. Der zweite Teil handelt von den historischen Hintergründen der Frage des Grundbesitzes in China zwischen 1949 und 1978 und beschreibt im Detail die Landpolitik der Kommunistischen Partei Chinas (CCP) von der Landreform zur Kollektivierung und schließlich zu der Dekollektivierung; im Speziellen wird darauf eingegangen, wie die CCP privaten Grundbesitz in kollektiven umgewandelt hat. Die „Gegenaktion“ wird verwendet, um das Verhalten der Bauern zu analysieren, das auf die CCP eingewirkt und schließlich die Politik der CCP sowohl vor als auch nach 1978 beeinflusst hat,. Der dritte Teil beschäftigt sich mit dem Thema der Privatisierung von Landbesitz und präsentiert verschiedene Meinungen und Argumente zu einer möglichen Privatisierung in China. Danach folgt eine Analyse der Frage, ob die Bauern von einer Privatisierung profitieren würden, die zu dem Schluss kommt, dass die Bauern von einer Landprivatisierung in China in gewisser Weise profitieren würden, diese aber nicht notwendigerweise alle Probleme lösen würde, mit welchen die chinesischen Bauern konfrontiert sind.Land issue has been very important for Chinaʼs rural development. This thesis looks into the land issue in China and discusses whether the privatization of Chinaʼs collective land ownership could be a solution. The first part introduces the topic and explains the theoretical framework – the peasantsʼ “counter action”. It also gives brief account of the state of art and defines the scope of discussion. The second part talks about the historical background of Chinaʼs land issue from 1949 to 1978, giving detailed accounts of the Chinese Communist Partyʼs (CCP) land policies from land reform to collectivization and then to de-collectivization, especially how the CCP gradually turned private land ownership into collective one. “Counter action” is used to analyze the peasantsʼ behaviour that interacted with the CCP and finally influenced the CCPʼs policies both before and after 1978. The third part brings in the topic of land privatization and presents different opinions and arguments on a possible land privatization in China, followed by analyses on whether privatization would benefit the peasants, which brings out a conclusion that land privatization in China could benefit peasants in a way but does not necessarily solve all the problems that Chinese peasants are facing

Environmental controls on coral skeletal δ13C in the northern South China Sea

In this paper, we investigate the relationship between seasonal climatic and environmental variables, and the skeletal δC of modern and mid-Holocene Porites lutea corals from the southern coast of Hainan Island in the northern South China Sea. No significant correlations were observed between δC in the modern coral and solar insolation or sea surface temperature. However, seasonal variability of δC in the modern coral covaries with rainfall on Hainan Island. Furthermore, the seasonal variations of δC in both the modern and mid-Holocene coral are synchronous with those of the coral ΔδO, which is a proxy for seawater δO and, in turn, largely controlled by local rainfall. These observations suggest that coral δC variations are closely associated with rainfall in this fregion. Given that river runoff contains dissolved inorganic carbon (DIC) with a negative δC, we suggest that periods of high rainfall on Hainan Island deliver increased amounts of C-depleted DIC to coastal seawater, resulting in an enhanced negative δC in the corals. Our findings, together with previous studies, appear to demonstrate that in coastal environments, coral skeletal δC levels are controlled mainly by terrestrial carbon input and are significantly influenced by terrestrial river runoff. Consequently, the geochemical interpretation of coral δC records may differ between coastal areas and offshore areas or the open ocean

Effect of recombinant human erythropoietin expressions of apoptosis genes in rats following traumatic brain injury

Purpose: To explore the effect of recombinant human erythropoietin (r-HuEPO) on apoptosis in rats after traumatic brain injury.Methods: A total of 48 traumatic brain-injured Sprague Dawley (SD) rats were obtained by improved Feeney’s traumatic brain injury model, and were randomly divided into four groups: normal salinetreated rats (control) and rats treated with r-HuEPO at doses of 1000 U/kg, 3000 U/kg and 5000 U/kg. Brain tissues were collected on the 7th day after trauma surgery. Apoptotic cells, and NF-kappa B (NFĸB)-, c-myc-, and Fas/Fasl-positive cells were identified in brain tissues by immunohistochemical assay.Results: After treatment with r-HuEPO (3000 and 5000 U/kg), expression of NF-κB and Fas/Fasl were significantly decreased (p < 0.05) compared to control rats, especially at the 5000 U/kg dose (p < 0.01). However, for c-myc, no significant difference was observed between r-HuEPO treatment and control groups (p > 0.05). Compared to the 1000 U/kg r-HuEPO group, Fas/Fasl expression levels were significantly lower in the 3000 and 5000 U/kg r-HuEPO groups (p < 0.05). Additionally, expression of NF-κB and Fasl in the 5000 U/kg r-HuEPO group was significantly lower than that in the 3000 U/kg r- HuEPO group (p < 0.05). Moreover, the number of apoptotic cells in the r-HuEPO group (5000 U/kg) was significantly lower than in the control group (p < 0.05).Conclusion: Thus, r-HuEPO may be beneficial for treating traumatic brain injury via inhibition of NFkappa B and Fas/Fasl expressions.Keywords: Recombinant human erythropoietin, NF-kappa B, Traumatic brain injury, Apoptosis, Neuronal damage, Fas/Fasl expressio

Comprehensive analysis on the magnetic field error of a K–Rb–21Ne comagnetometer with low-frequency bias magnetic field sensitivity

The spin-exchange relaxation-free comagnetometer (SERFC) is of important research value compared to existing high-precision gyroscopes because of its extremely high theoretical limit sensitivity and long-term stability, in which one significant limiting factor is the magnetic field error. First, the relationship between the magnetic field gradient and the nuclear spin relaxation mechanism is introduced into the frequency response and steady-state response models of SERFC. Then, a novel method for suppression of the low-frequency magnetic field error based on the modified bias magnetic field sensitivity model is proposed. Finally, the effectiveness of the proposed suppression methods is demonstrated by optimizing the cell temperature, pump light power, and compensation magnetic field gradient to increase the suppression factor by 72.19%, 20.24%, and 69.86%, and the corresponding bias instability increased by 55.41%, 20.84%, and 27.63%, respectively. This study contributes to improving the long-term zero bias stability of the SERFC

TREA: Tree-Structure Reasoning Schema for Conversational Recommendation

Conversational recommender systems (CRS) aim to timely trace the dynamic interests of users through dialogues and generate relevant responses for item recommendations. Recently, various external knowledge bases (especially knowledge graphs) are incorporated into CRS to enhance the understanding of conversation contexts. However, recent reasoning-based models heavily rely on simplified structures such as linear structures or fixed-hierarchical structures for causality reasoning, hence they cannot fully figure out sophisticated relationships among utterances with external knowledge. To address this, we propose a novel Tree structure Reasoning schEmA named TREA. TREA constructs a multi-hierarchical scalable tree as the reasoning structure to clarify the causal relationships between mentioned entities, and fully utilizes historical conversations to generate more reasonable and suitable responses for recommended results. Extensive experiments on two public CRS datasets have demonstrated the effectiveness of our approach.Comment: Accepted by ACL2023 main conferenc

Low-Complexity Acoustic Scene Classification Using Data Augmentation and Lightweight ResNet

We present a work on low-complexity acoustic scene classification (ASC) with multiple devices, namely the subtask A of Task 1 of the DCASE2021 challenge. This subtask focuses on classifying audio samples of multiple devices with a low-complexity model, where two main difficulties need to be overcome. First, the audio samples are recorded by different devices, and there is mismatch of recording devices in audio samples. We reduce the negative impact of the mismatch of recording devices by using some effective strategies, including data augmentation (e.g., mix-up, spectrum correction, pitch shift), usages of multi-patch network structure and channel attention. Second, the model size should be smaller than a threshold (e.g., 128 KB required by the DCASE2021 challenge). To meet this condition, we adopt a ResNet with both depthwise separable convolution and channel attention as the backbone network, and perform model compression. In summary, we propose a low-complexity ASC method using data augmentation and a lightweight ResNet. Evaluated on the official development and evaluation datasets, our method obtains classification accuracy scores of 71.6% and 66.7%, respectively; and obtains Log-loss scores of 1.038 and 1.136, respectively. Our final model size is 110.3 KB which is smaller than the maximum of 128 KB.Comment: 5 pages, 5 figures, 4 tables. Accepted for publication in the 16th IEEE International Conference on Signal Processing (IEEE ICSP