bluuebunny/crossref_metadata_2025_split huggingface dataset:
US Arctic policymaking under Trump and Obama
Authors: Weingartner Katherine A. , Orttung Robert W. 
Published: January 2020

AbstractThough presidential personality and preferences heavily influence US Arctic policy, climate change and the perceived threat to US interests posed by rising international engagement in the north among great powers such as Russia and China are increasingly impacting US policy in the region. Recognising that these trends are likely to persist into the future, it is important to understand the US Arctic policymaking apparatus, how geopolitical and environmental factors affect the creation and implementation of such policies through the presidency and how the resulting presidential policies may impact US leadership in the region for years to come. Consequently, this article examines how the distinct styles and preferences of Presidents Obama and Trump interact with growing climate change and defence challenges in the region within the US Arctic policymaking process. We illustrate this interaction through examples at both domestic and international policy levels and then place it in the larger context of the differing presidential approaches to institutionalisation when setting policy. Ultimately, we conclude that not only do presidential priorities regarding climate change, rising international engagement, and institutionalisation critically influence Arctic policymaking, but how a future president views these issues will heavily impact the direction of policies affecting the region.
Dynamic Optimization of a Steerable Screw In-pipe Inspection Robot Using HJB and Turbine Installation
Authors: Tourajizadeh H. , Boomeri V. , Rezaei M. , Sedigh A. 
Published: January 2020

SUMMARYIn this paper, two strategies are proposed to optimize the energy consumption of a new screw in-pipe inspection robot which is steerable. In the first method, optimization is performed using the optimal path planning and implementing the Hamilton–Jacobi–Bellman (HJB) method. Since the number of actuators is more than the number of degrees of freedom of the system for the proposed steerable case, it is possible to minimize the energy consumption by the aid of the dynamics of the system. In the second method, the mechanics of the robot is modified by installing some turbine blades through which the drag force of the pipeline fluid can be employed to decrease the required propulsion force of the robot. It is shown that using both of the mentioned improvements, that is, using HJB formulation for the steerable robot and installing the turbine blades can significantly save power and energy. However, it will be shown that for the latter case this improvement is extremely dependent on the alignment of the fluid stream direction with respect to the direction of the robot velocity, while this optimization is independent of this case for the former strategy. On the other hand, the path planning dictates a special pattern of speed functionality while for the robot equipped by blades, saving the energy is possible for any desired input path. The correctness of the modeling is verified by comparing the results of MATLAB and ADAMS, while the efficiency of the proposed optimization algorithms is checked by the aid of some analytic and comparative simulations.
ON LINEAR RELATIONS FOR DIRICHLET SERIES FORMED BY RECURSIVE SEQUENCES OF SECOND ORDER
Authors: ELSNER CARSTEN , TECHNAU NICLAS 
Published: January 2020

AbstractLet $F_{n}$ and $L_{n}$ be the Fibonacci and Lucas numbers, respectively. Four corresponding zeta functions in $s$ are defined by $$\begin{eqnarray}\unicode[STIX]{x1D701}_{F}(s):=\mathop{\sum }_{n=1}^{\infty }{\displaystyle \frac{1}{F_{n}^{s}}},\quad \unicode[STIX]{x1D701}_{F}^{\ast }(s):=\mathop{\sum }_{n=1}^{\infty }{\displaystyle \frac{(-1)^{n+1}}{F_{n}^{s}}},\quad \unicode[STIX]{x1D701}_{L}(s):=\mathop{\sum }_{n=1}^{\infty }{\displaystyle \frac{1}{L_{n}^{s}}},\quad \unicode[STIX]{x1D701}_{L}^{\ast }(s):=\mathop{\sum }_{n=1}^{\infty }{\displaystyle \frac{(-1)^{n+1}}{L_{n}^{s}}}.\end{eqnarray}$$ As a consequence of Nesterenko’s proof of the algebraic independence of the three Ramanujan functions $R(\unicode[STIX]{x1D70C}),Q(\unicode[STIX]{x1D70C}),$ and $P(\unicode[STIX]{x1D70C})$ for any algebraic number $\unicode[STIX]{x1D70C}$ with $0<\unicode[STIX]{x1D70C}<1$, the algebraic independence or dependence of various sets of these numbers is already known for positive even integers $s$. In this paper, we investigate linear forms in the above zeta functions and determine the dimension of linear spaces spanned by such linear forms. In particular, it is established that for any positive integer $m$ the solutions of $$\begin{eqnarray}\mathop{\sum }_{s=1}^{m}(t_{s}\unicode[STIX]{x1D701}_{F}(2s)+u_{s}\unicode[STIX]{x1D701}_{F}^{\ast }(2s)+v_{s}\unicode[STIX]{x1D701}_{L}(2s)+w_{s}\unicode[STIX]{x1D701}_{L}^{\ast }(2s))=0\end{eqnarray}$$ with $t_{s},u_{s},v_{s},w_{s}\in \mathbb{Q}$$(1\leq s\leq m)$ form a $\mathbb{Q}$-vector space of dimension $m$. This proves a conjecture from the Ph.D. thesis of Stein, who, in 2012, was inspired by the relation $-2\unicode[STIX]{x1D701}_{F}(2)+\unicode[STIX]{x1D701}_{F}^{\ast }(2)+5\unicode[STIX]{x1D701}_{L}^{\ast }(2)=0$. All the results are also true for zeta functions in $2s$, where the Fibonacci and Lucas numbers are replaced by numbers from sequences satisfying a second-order recurrence formula.
Does poor health mobilize people into action? Health, political trust, and participation
Authors: Mattila Mikko 
Published: January 2020

AbstractRecently, awareness of the importance of health in explaining political participation has grown considerably. Studies have focused on individual participation forms but not on broader participation modes. Furthermore, analyses of the mechanisms explaining the health effects have been lacking. Here, structural equation models are employed to study the relationship between health, political trust, and institutional and non-institutional participation using data from Finland. Poor health is related to increased non-institutional participation, while good health boosts traditional institutional participation, although the latter relationship is very weak. These observations are explained by differences in political trust. Those in good health have stronger trust in the political system, while poor health is connected with reduced trust. These differences manifest themselves in varying behaviour. Poor health decreases trust which leads to increased non-institutional participation, while good health leads to a high trust and institutional activities.
Observations of the Wire Destruction and Plasma Channel Reestablishment Process During the Initial Stage of Triggered Lightning
Authors: Li Shulei , Qiu Shi , Shi Lihua , Li Yun , Dong Wansheng 
Published: January 2020

AbstractThe wire destruction and plasma channel reestablishment process during the initial stage of a triggered lightning is analyzed based on comprehensive observations, including very high frequency (VHF) mapping array, electric‐magnetic field, and high‐speed video. The detailed discharge processes in both the attempted reconnection process and reconnection process are firstly evidenced by VHF mapping results. The reconnection process is similar to a leader/return‐stroke sequence, while the attempted reconnection process involves more complicated discharges. It is shown that several segments of the wire are fused firstly due to inhomogeneity of the wire, resulting in a series of wire residues. Thereafter, downward extending VHF breakdowns dispersed over hundreds of meters in altitude followed by a recoil‐like event, both of which emitted fairly weak VHF radiation, and no detectable LF electromagnetic field change was observed. It is indicated that there are no significant current flowing or charges movement during the attempted reconnection process.
Africa's Climate Response to Solar Radiation Management With Stratospheric Aerosol
Authors: Pinto Izidine , Jack Christopher , Lennard Christopher , Tilmes Simone , Odoulami Romaric C. 
Published: January 2020

AbstractAnthropogenic warming is projected to increase the magnitude and frequency of extreme events, whose impacts are already being felt in vulnerable regions in sub‐Saharan Africa. Solar radiation management (SRM) has been proposed as an interim measure to offset warming while emissions are reduced; however, the impact of stratospheric SRM on regional climate extremes have not yet been explored, particularly in the Paris agreement context. We investigate the potential impact of SRM on temperature and rainfall means and extremes over sub‐Saharan Africa using simulations from the Geoengineering Large Ensemble. We found SRM significantly reduces temperature means and extremes; however, the effect on precipitation is not as linear. The results should be interpreted with caution as they are particular to this approach of SRM and this modelling experiment.
Continuously Changing Quartz‐Albite Saturated Melt Compositions to 330 °C With Application to Heat Flow and Geochemistry of the Ocean Crust
Authors: Lundstrom C. C. 
Published: January 2020

AbstractMelt compositions in equilibrium with quartz and albite at 0.1 GPa and temperatures from 819 to 330 °C are reported for cold seal experiments in the Na2O‐Al2O3‐SiO2‐H2O system. At 60–70 °C intervals, melt compositions continuously change from rhyolite‐like melts with <10 wt.% H2O at the quartz‐albite eutectic to melts of nearly endmember Na2Si2O5 having >30 wt.% H2O at 330 °C (vapor undersaturated). Melt Na2O increases while SiO2 and Al2O3 decrease down temperature. Experiments performed at T > 600 °C are vapor saturated with <9.9–21 wt.% H2O while those T < 600 °C are vapor undersaturated with 18–37 wt.% H2O. Because of the continuous change in the liquid's composition down temperature, all compositions can be called melts; in reality, their high water contents may also lead to being termed hydrous fluids. These results indicate that igneous processes continue to temperatures >300 °C below the haplogranite solidus. The water‐rich melts at low temperature have low viscosities and densities suggesting that they buoyantly ascend by reactive flow at low melt porosities (<5%). Formation of low‐temperature melt will occur along the sides of gabbro bodies of mid‐ocean ridges, resulting in large‐scale convection that removes heat from the lower crust. This circulation may move heat off axis influencing observed heat flow. Melt reaction processes result in silicic differentiates (plagiogranites) and formation of greenschist metabasalts. This frees calcium from silicate bonding, providing an important sink for CO2 in Earth's carbon cycle. Sr isotopes of the ocean crust change with ocean crust production rates indicating mid‐ocean ridge systems are a major control on Earth's climate over time.
Numerical Study of the Exchange Flow of the Persian Gulf Using an Extended Total Exchange Flow Analysis Framework
Authors: Lorenz Marvin , Klingbeil Knut , Burchard Hans 
Published: January 2020

AbstractThe Total Exchange Flow analysis framework computes consistent bulk values quantifying the estuarine exchange flow using salinity coordinates since salinity is the main contributor to density in estuaries and the salinity budget is entirely controlled by the exchange flow. For deeper and larger estuaries temperature may contribute equally or even more to the density. That is why we included potential temperature as a second coordinate to the Total Exchange Flow analysis framework, which allows gaining insights in the potential temperature‐salinity structure of the exchange flow as well as to compute consistent bulk potential temperature and therefore heat exchange values with the ocean. We applied this theory to the exchange flow of the Persian Gulf, a shallow, semienclosed marginal sea, where dominant evaporation leads to the formation of hypersaline and dense Gulf water. This drives an inverse estuarine circulation which is analyzed with special interest on the seasonal cycle of the exchange flow. The exchange flow of the Persian Gulf is numerically simulated with the General Estuarine Transport Model from 1993 to 2016 and validated against observations. Results show that a clear seasonal cycle exists with stronger exchange flow rates in the first half of the year. Furthermore, the composition of the outflowing water is investigated using passive tracers, which mark different surface waters. The results show that in the first half of the year, most outflowing water comes from the southern coast, while in the second half most water originates from the northwestern region.
Effects on Ocean Biology Induced by El Niño‐Accompanied Positive Freshwater Flux Anomalies in the Tropical Pacific
Authors: Tian Feng , Zhang Rong‐Hua , Wang Xiujun 
Published: January 2020

AbstractThe El Niño and Southern Oscillation (ENSO) can induce large perturbations in freshwater flux (FWF, defined as precipitation minus evaporation) and ocean ecosystem in the tropical Pacific. However, how El Niño‐induced FWF can affect the tropical Pacific ecosystem (e.g., chlorophyll) is still unknown. Here, a series of ocean‐only experiments are performed using a coupled ocean‐physical biogeochemistry model forced by prescribed climatological wind stress. Interannual FWF anomalies observed during the 1997–1998 El Niño event are imposed onto the ocean model in the tropical Pacific, and the related positive FWF anomalies are specified to be varying in its intensity, and the corresponding sensitivity experiments are performed to examine the ocean ecosystem response. In general, chlorophyll increases with the intensities of the El Niño‐induced positive FWF anomalies at a certain strength but decreases when the positive FWF forcing is underrepresented (e.g., specified to be its half intensity). Additionally, chlorophyll in the eastern tropical Pacific keeps almost steady during the increasing stage of the El Niño‐induced interannual FWF forcing and then rapidly increases after the peak stage of the FWF forcing. The phytoplankton budget and diagnostic analyses are conducted to understand the behavior of chlorophyll in response to varying intensities of FWF forcing. Chlorophyll response to varying intensities of FWF forcing depends on the iron concentration in the mixed layer, suggesting that the ocean ecosystem response may be shifted from one regime to another when FWF forcing reaches a certain intensity. These results offer insights into biophysical interactions and chlorophyll‐induced feedback effects on ENSO.
Synoptic Meteorology Explains Temperate Forest Carbon Uptake
Authors: Randazzo Nina A. , Michalak Anna M. , Desai Ankur R. 
Published: January 2020

AbstractWhile substantial attention has been paid to the effects of both global climate oscillations and local meteorological conditions on the interannual variability of ecosystem carbon exchange, the relationship between the interannual variability of synoptic meteorology and ecosystem carbon exchange has not been well studied. Here we use a clustering algorithm to identify a summertime cyclonic precipitation system northwest of the Great Lakes to determine (a) the association at a daily scale between the occurrence of this system and the local meteorology and net ecosystem exchange at three Great Lakes region forested eddy covariance sites and (b) the association between the seasonal prevalence of this system and the summertime net ecosystem exchange of these sites. We find that temperature, in addition to precipitation and cloud cover, is an important explanatory factor for the suppression of net ecosystem productivity that occurs during these cyclonic events in this region. In addition, the prevalence of this cyclonic system can explain a significant proportion of the interannual variability in summertime forest ecosystem exchange in this region. This explanatory power is not due to a simple accumulation of low‐productivity days that cooccur with this meteorological event, but rather a broader association between the frequency of these events and several aspects of prevailing seasonal conditions. This work demonstrates the usefulness of conceptualizing meteorology in terms of synoptic systems for explaining the interannual variability of regional carbon fluxes.
Drp1-mediated mitochondrial fission promotes renal fibroblast activation and fibrogenesis
Authors: Wang Yating , Lu Miaoqing , Xiong Liping , Fan Jinjin , Zhou Yi , Li Huiyan , Peng Xuan , Zhong Zhong , Wang Yihan , Huang Fengxian , Chen Wei , Yu Xueqing , Mao Haiping 
Published: January 2020

AbstractExcessive mitochondrial fission acts as a pro-proliferative marker in some cancers and organ fibrosis; its potential role in renal fibroblast activation and fibrogenesis has never been investigated. Here, we showed more pronounced fragmented mitochondria in fibrotic than in non-fibrotic renal fibroblast in humans and mice. In a mouse model of obstructive nephropathy, phosphorylation of Drp1 at serine 616 (p-Drp1S616) and acetylation of H3K27(H3K27ac) was increased in fibrotic kidneys; pharmacological inhibition of mitochondrial fission by mdivi-1 substantially reduced H3K27ac levels, fibroblasts accumulation, and interstitial fibrosis. Moreover, mdivi-1 treatment was able to attenuate the established renal fibrosis. In cultured renal interstitial fibroblasts, targeting Drp1 using pharmacological inhibitor or siRNA suppressed TGF-β1-elicited cell activation and proliferation, as evidenced by inhibiting expression of α-smooth muscle actin (α-SMA) and collagen I, as well as by reducing DNA synthesis. In contrast, Drp1 deletion enhanced cell apoptosis, along with decreased mitochondrial fragmentation, mtROS elevation, and glycolytic shift upon TGF-β1 stimulation. In Drp1 deletion fibroblasts, re-expression of wild-type Drp1 rather than Drp1S616A mutant restores the reduction of TGF-β-induced-Drp1 phosphorylation, H3K27ac, and cell activation. Moreover, TGF-β1 treatment increased the enrichment of H3K27ac at the promoters of α-SMA and PCNA, which was reversed in Drp1-knockdown fibroblasts co-transfected with empty vector or Drp1S616A, but not wild-type Drp1. Collectively, our results imply that inhibiting p-Drp1S616-mediated mitochondrial fission attenuates fibroblast activation and proliferation in renal fibrosis through epigenetic regulation of fibrosis-related genes transcription and may serve as a therapeutic target for retarding progression of chronic kidney disease.
Improvement of epidermal covering on AEC patients with severe skin erosions by PRIMA-1MET/APR-246
Authors: Aberdam Edith , Roux Lauriane N. , Secrétan Philippe-Henri , Boralevi Franck , Schlatter Joël , Morice-Picard Fanny , Sol Stefano , Bodemer Christine , Missero Caterina , Cisternino Salvatore , Aberdam Daniel , Hadj-Rabia Smail 
Published: January 2020

AbstractP63 is a major transcription factor regulating skin development and homeostasis. It controls many genes involved in cell proliferation, adhesion, and early differentiation. P63 is mutated in several rare syndromes called p63-related ectodermal dysplasia syndromes (ED). The main forms are EEC and AEC syndromes due to p63 missense mutations on the DBD and SAM domains, respectively. ED patients display many developmental defects, including ectrodactyly, clef/lip palate, and ectodermal dysplasia, while AEC patients suffer from severe skin erosions that not always heal. We have previously showed that ED-derived iPSC display altered epidermal commitment. P63 belongs to the p53 gene family sharing similar structural domains. We found that ED-iPSC epidermal commitment can be rescued by a p53-reactivating compounds called PRIMA-1MET, also named APR-246 and currently used in anticancer clinical trials. Here, we established primary epidermal culture from two AEC children (S.F. and Y.M.) suffering from persistent skin erosions at age of 9 and 15, respectively. These patients carry missense mutations on the SAM domain (I576T and I537T). We found that primary keratinocytes (KCs) isolated from these AEC patients underwent altered epidermal differentiation that was rescued by PRIMA-1MET treatment. It prompted us to formulate the compound onto a cream that was topically applied on the right hand of one patient and on the scalp of the second patient. In both cases, the daily treatment allowed re-epithelialization of the eroded skin and a drastic loss of pain after few weeks, improving quality of life. Normally, mutant p63 exerts a dominant-negative effect, mainly through the formation of aggregate with WT p63 and p73. PRIMA-1MET did not reduce protein aggregation while enhancing cell differentiation, suggesting that PRIMA-1MET targets cell differentiation and not p63 activity directly. In conclusion, we propose that repurposing of the antitumoral PRIMA-1MET compound could become a general treatment of AEC skin erosions.
The nuclear translocation of transketolase inhibits the farnesoid receptor expression by promoting the binding of HDAC3 to FXR promoter in hepatocellular carcinoma cell lines
Authors: Li Minle , Zhang Xuping , Lu Ying , Meng Sen , Quan Haoyu , Hou Pingfu , Tong Pan , Chai Dafei , Gao Xiaoge , Zheng Junnian , Tong Xuemei , Bai Jin 
Published: January 2020

AbstractTransketolase (TKT), which is a metabolic enzyme in the nonoxidative phase of the pentose phosphate pathway (PPP), plays an important role in providing cancer cells with raw materials for macromolecular biosynthesis. The ectopic expression of TKT in hepatocellular carcinoma (HCC) was reported previously. However, the role of TKT in the initiation of liver cancer is still obscure. In our previous study, we found that TKT deficiency protects the liver from DNA damage by increasing levels of ribose 5-phosphate and nucleotides. What’s more interesting is that we found TKT deficiency reduced bile acids and loss of TKT promoted the farnesoid receptor (FXR) expression. We further showed that TKT translocated into the nucleus of HCC cell lines through interacting with the signal transducer and activator of transcription 1 (STAT1), and then the complex inhibited FXR expression by promoting the binding of histone deacetylase 3 (HDAC3) to FXR promoter.
circRNA-002178 act as a ceRNA to promote PDL1/PD1 expression in lung adenocarcinoma
Authors: Wang JunFeng , Zhao XuHai , Wang YanBo , Ren FengHai , Sun DaWei , Yan YuBo , Kong XiangLong , Bu JianLong , Liu MengFeng , Xu ShiDong 
Published: January 2020

AbstractCircular RNAs (circRNAs) have been identified play a vital role in various different types of cancer via sponging miRNAs (microRNAs). However, their role in lung adenocarcinoma (LUAD) remains largely unclear. In this study, we systematically characterized the circRNA expression profiles in the LUAD cancer tissues and paired adjacent non-cancerous tissues. Three circRNAs were found to be significantly upregulated. Among them, has-circRNA-002178 was further confirmed to be upregulated in the LUAD tissues, and LUAD cancer cells. Subsequently, we also found has-circRNA-002178 could enhance PDL1 expression via sponging miR-34 in cancer cells to induce T-cell exhaustion. More importantly, circRNA-002178 could be detected in exosomes of plasma from LUAD patients and could serve as biomarkers for LUAD early diagnosis. Finally, we found circRNA-002178 could be delivered into CD8+ T cells to induce PD1 expression via exosomes. Taken together, our study revealed that circRNA-002178 could act as a ceRNA to promote PDL1/PD1 expression in lung adenocarcinoma.