Biogeochemical Impact of Long-Range Transported Dust over Northern South China Sea

Transpacific transport and impact of Asian dust aerosols have been well documented (e.g., results from ACE-Asia and regional follow-on campaigns), but little is known about dust invasion to the South China Sea (SCS). On 19-21 March 2010, a fierce Asian dust storm affected large areas from the Gobi deserts to the West Pacific, including Taiwan and Hong Kong. As a pilot study of the 7-SEAS (Seven South East Asian Studies) in the northern SCS, detailed characteristics of long-range transported dust aerosols were first observed by a comprehensive set of ground-based instruments deployed at the Dongsha islands (20deg42'52" N, 116deg43'51" E). Aerosol measurements such as particle mass concentrations, size distribution, optical properties, hygroscopicity, and vertical profiles help illustrate the evolution of this dust outbreak. Our results indicate that these dust particles were mixed with anthropogenic and marine aerosols, and transported near the surface. Satellite assessment of biogeochemical impact of dust deposition into open oceans is hindered by our current inability in retrieving areal dust properties and ocean colors over an extensive period of time, particularly under the influence of cloudy conditions. In this paper, we analyze the changes of retrieved Chlorophyll-a (Chl-a) concentration over the northern SCS, considered as oligotophic waters in the spring, from long-term SeaWiFS measurements since 1997. Over the past decade, six long-range transported dust events are identified based on spatiotemporal evolutions of PM10 measurements from regional monitoring stations, with the aid of trajectory analysis. Multi-year composites of Chl-a imagery for dust event and non-dust background during March-April are applied to overcome insufficient retrievals of Chl-a due to cloudy environment. Due to anthropogenic modification within a shallow boundary layer off the densely populated and industrial southeast coast of China, the iron ion activation of deliquescent dust particles enhances the efficiency of fertilization for biological productivity. Compared to the West Pacific, the marine ecosystem in the northern SCS is much more susceptible to the biogeochemical impact of long-range transported Asian dust

Advancing the study of life and death education: theoretical framework and research inquiries for further development

Life and death education, also known as life education and death education, is an interesting subject that may coincide with the subject of lifespan development. In brief, from our theoretical perspective, which guides our teaching and curriculum development, life education considers personal understanding of life functioning on a daily basis, whereas death education explores matters that are related to death and dying. For example, how can a social worker utilize his life knowledge, or life wisdom, to assist a relative to understand the intricate nature of death? In a similar vein, how can a senior citizen use her personal experience of Buddhist meditation practice to overcome a minor Covid setback? Central to our teaching practice is the premise of ‘active transformation’ (i.e., transforming life knowledge into positive practice) and the premise of ‘theoretical infusion’ (e.g., the infusion of a distinctive epistemological belief in the teaching of life) that would, in turn, help to enhance and facilitate deep, meaningful understanding of life and death. The purpose of the present article is for us to discuss a proposition of a theoretical-conceptual model, which depicts the ‘unification’ or integration of three major viewpoints of life and death: the social viewpoint, the philosophical viewpoint, and the psychological viewpoint. We theorize that unification of the three theoretical viewpoints may help provide grounding for effective teaching and holistic understanding of the subject contents of life and death. Such discourse, importantly, may also assist to advance the scope and complexity of the lifespan development subject. Finally, in addition to our theoretical-conceptual model of life and death, we propose three major research inquiries for development: the meaning of situated mindset, the underlying nature of spiritual transcendence, and proposition of appropriate methodological accounts for usage. Overall, then, we purport that our conceptual analysis and discussion overview, based on philosophical reflection, may serve to stimulate interest, intellectual curiosity, scholarly dialog, etc

Sampling-based Algorithms for Optimal Motion Planning

During the last decade, sampling-based path planning algorithms, such as Probabilistic RoadMaps (PRM) and Rapidly-exploring Random Trees (RRT), have been shown to work well in practice and possess theoretical guarantees such as probabilistic completeness. However, little effort has been devoted to the formal analysis of the quality of the solution returned by such algorithms, e.g., as a function of the number of samples. The purpose of this paper is to fill this gap, by rigorously analyzing the asymptotic behavior of the cost of the solution returned by stochastic sampling-based algorithms as the number of samples increases. A number of negative results are provided, characterizing existing algorithms, e.g., showing that, under mild technical conditions, the cost of the solution returned by broadly used sampling-based algorithms converges almost surely to a non-optimal value. The main contribution of the paper is the introduction of new algorithms, namely, PRM* and RRT*, which are provably asymptotically optimal, i.e., such that the cost of the returned solution converges almost surely to the optimum. Moreover, it is shown that the computational complexity of the new algorithms is within a constant factor of that of their probabilistically complete (but not asymptotically optimal) counterparts. The analysis in this paper hinges on novel connections between stochastic sampling-based path planning algorithms and the theory of random geometric graphs.Comment: 76 pages, 26 figures, to appear in International Journal of Robotics Researc

Tracing magnetism and pairing in FeTe-based systems

In order to examine the interplay between magnetism and superconductivity, we monitor the non- superconducting chalcogenide FeTe and follow its transitions under insertion of oxygen, doping with Se and vacancies of Fe using spin-polarized band structure methods (LSDA with GGA) starting from the collinear and bicollinear magnetic arrangements. We use a supercell of Fe8Te8 as our starting point so that it can capture local changes in magnetic moments. The calculated values of magnetic moments agree well with available experimental data while oxygen insertions lead to significant changes in the bicollinear or collinear magnetic moments. The total energies of these systems indicate that the collinear-derived structure is the more favorable one prior to a possible superconducting transition. Using a 8-site Betts-cluster-based lattice and the Hubbard model, we show why this structure favors electron or hole pairing and provides clues to a common understanding of charge and spin pairing in the cuprates, pnictides and chalcogenides

Introducing the Study of Life and Death Education to Support the Importance of Positive Psychology: An Integrated Model of Philosophical Beliefs, Religious Faith, and Spirituality

Life education, also known as life and death education, is an important subject in Taiwan with institutions (e.g., high school) offering degree programs and courses that focus on quality learning and implementation of life education. What is interesting from the perspective of Taiwanese education is that the teaching of life education also incorporates a number of Eastern-derived and conceptualized tenets, for example, Buddhist teaching and the importance of spiritual wisdom. This premise contends then that life education in Taiwan, in general, is concerned with the promotion, fulfillment, and cherishing of quality life experiences (e.g., personal contentment, happiness). One example of life education, which resonates with other spiritual beliefs and religious faiths (e.g., Hinduism), is related to spiritual cultivation and the enlightenment of life wisdom. Our own teaching of the subject, likewise, places emphasis on the goal of teaching students to seek meaningful understanding of and appreciation for three major, interrelated components of life education: life wisdom, life practice, and life care. It has been acknowledged, to a certain degree, that life education has made meaningful contributions, such as the creation and facilitation of a civil, vibrant society, and that many Taiwanese individuals show dignity, respect for elders, and reverence for spiritual and religious faiths. For example, aside from high-quality hospice care, many Taiwanese engage in different types of benevolent acts (e.g., providing spiritual advice to someone who is dying), where possible. Life education is a beneficial subject for teaching and learning as its theoretical understanding may help individuals cope with pathologies and negative conditions and life experiences. One negative life experience, in this case, is the ultimate fate of humankind: death. Approaching death and/or the onset of grief is something that we all have to experience. How does one approach death? It is not easy feat, and of course, grief for a loved one is personal, and some of us struggle with this. We contend that spiritual cultivation and enlightenment, arising from life education, may assist us with the topic of death (e.g., the possibility of transcendence beyond the realm of life). More importantly however, from our own teaching experiences and research development, we strongly believe and rationalize that the subject of life education could, indeed, coincide with and support the paradigm of positive psychology (Seligman, 1999, 2010; Seligman and Csíkszentmihályi, 2000). Forming the premise of the present conceptual analysis article, we propose that a person’s "spiritual and enlightened self," reflecting the convergence of three major aspects of life education (i.e., philosophical reflection, enrichment of personal well-being, and spiritual cultivation), would result in the initiation and creation of a number of virtues and positive characteristics, for example, having a positive outlook in life, having a perceived sense of spirituality, showing compassion, forgiveness, etc. These virtues and quality characteristics, from our philosophical reasoning, are equivalent to those qualities that the paradigm of positive psychology advocates for. In summary, we conceptualize that the subject of life education, from the perspective of Taiwanese education, may intertwine with the paradigm of positive psychology. A person’s spiritual and enlightened self, or his/her "holistic self," from our rationalization, is the ultimate optimal life experience that he/she may have, enabling him/her to address the gamut of life conditions and experiences. The distinctive nature of life education in this case, as a point of summary, is that it incorporates spiritual beliefs and religious faiths (e.g., Buddhist faith), encouraging a person to seek nature and divine–human relationships, as well as to contemplate and to explore the complex nature of his/her inner self. The notion of Buddhist samsâra, for example, as "evidence" of spirituality, entailing the endless cycle of birth, rebirth, and redeath, may provide a person with hope into the afterlife. Such esoteric discourse, we contend, is positive and optimistic, allowing individuals to discard the dividing line between life and death

Large-Scale Covariability Between Aerosol and Precipitation Over the 7-SEAS Region: Observations and Simulations

One of the seven scientific areas of interests of the 7-SEAS field campaign is to evaluate the impact of aerosol on cloud and precipitation (http://7-seas.gsfc.nasa.gov). However, large-scale covariability between aerosol, cloud and precipitation is complicated not only by ambient environment and a variety of aerosol effects, but also by effects from rain washout and climate factors. This study characterizes large-scale aerosol-cloud-precipitation covariability through synergy of long-term multi ]sensor satellite observations with model simulations over the 7-SEAS region [10S-30N, 95E-130E]. Results show that climate factors such as ENSO significantly modulate aerosol and precipitation over the region simultaneously. After removal of climate factor effects, aerosol and precipitation are significantly anti-correlated over the southern part of the region, where high aerosols loading is associated with overall reduced total precipitation with intensified rain rates and decreased rain frequency, decreased tropospheric latent heating, suppressed cloud top height and increased outgoing longwave radiation, enhanced clear-sky shortwave TOA flux but reduced all-sky shortwave TOA flux in deep convective regimes; but such covariability becomes less notable over the northern counterpart of the region where low ]level stratus are found. Using CO as a proxy of biomass burning aerosols to minimize the washout effect, large-scale covariability between CO and precipitation was also investigated and similar large-scale covariability observed. Model simulations with NCAR CAM5 were found to show similar effects to observations in the spatio-temporal patterns. Results from both observations and simulations are valuable for improving our understanding of this region's meteorological system and the roles of aerosol within it. Key words: aerosol; precipitation; large-scale covariability; aerosol effects; washout; climate factors; 7- SEAS; CO; CAM

To What Extent Iron-Pnictide New Superconductors Have Been Clarified: A Progress Report

In this review, the authors present a summary of experimental reports on newly discovered iron-based superconductors as they were known at the end of 2008. At the same time, this paper is intended to be useful for experimenters to know the current status of these superconductors. The authors introduce experimental results that reveal basic physical properties in the normal and superconducting states. The similarities and differences between iron-pnictide superconductors and other unconventional superconductors are also discussed.Comment: 20 pages, 32 figures. Open selec

Electronic Origin of High Temperature Superconductivity in Single-Layer FeSe Superconductor

The latest discovery of high temperature superconductivity signature in single-layer FeSe is significant because it is possible to break the superconducting critical temperature ceiling (maximum Tc~55 K) that has been stagnant since the discovery of Fe-based superconductivity in 2008. It also blows the superconductivity community by surprise because such a high Tc is unexpected in FeSe system with the bulk FeSe exhibiting a Tc at only 8 K at ambient pressure which can be enhanced to 38 K under high pressure. The Tc is still unusually high even considering the newly-discovered intercalated FeSe system A_xFe_{2-y}Se_2 (A=K, Cs, Rb and Tl) with a Tc at 32 K at ambient pressure and possible Tc near 48 K under high pressure. Particularly interesting is that such a high temperature superconductivity occurs in a single-layer FeSe system that is considered as a key building block of the Fe-based superconductors. Understanding the origin of high temperature superconductivity in such a strictly two-dimensional FeSe system is crucial to understanding the superconductivity mechanism in Fe-based superconductors in particular, and providing key insights on how to achieve high temperature superconductivity in general. Here we report distinct electronic structure associated with the single-layer FeSe superconductor. Its Fermi surface topology is different from other Fe-based superconductors; it consists only of electron pockets near the zone corner without indication of any Fermi surface around the zone center. Our observation of large and nearly isotropic superconducting gap in this strictly two-dimensional system rules out existence of node in the superconducting gap. These results have provided an unambiguous case that such a unique electronic structure is favorable for realizing high temperature superconductivity

T-lymphocyte subsets in liver tissues of patients with primary biliary cirrhosis (PBC), patients with primary sclerosing cholangitis (PSC), and normal controls

T lymphocytes infiltrating hepatic tissues were typed and enumerated in liver biopsies of patients with primary biliary cirrhosis (PBC), patients with primary sclerosing cholangitis (PSC), and normal controls using monoclonal antibodies and the avidin-biotin-immunoperoxidase technique. The peripheral blood mononuclear cells were studied also by flow cytometry. In PBC, T lymphocytes were decreased (P<0.001) in the blood [absolute number was 426±200 (SE) vs 1351±416 in 15 controls], as was the helper/suppressor (T4/T8) ratio (1.0±0.1 vs normal 2.3±0.3). T lymphocytes were the most numerous mononuclear cells infiltrating portal areas of PBC livers: 749±93/5 high-power fields (HPF) in PBC vs 98±15/5 HPF (P<0.01) in controls. The T4/T8 ratios varied from 0.9 to 2.3 (mean, 1.8±0.1) in the portal triads (normal mean, 1.6±0.1), with the T4+ cells accounting for more than 75% of infiltrating T cells. In contrast, the mean T4/T8 ratio in portal triads of PSC was reduced (1.0±0.3) due to a significant increase (P<0.001) in the number of T8+ cells. The T cells around and in the walls of bile ducts in PBC were mostly T8+, and the T4/T8 ratio was 0.8±0.2. No T8+ cells were seen in this location in PSC and normal livers. Few mononuclear cells were present in hepatic lobules. Subtyping of T lymphocytes in liver tissues of patients with PBC and PSC may be helpful in the differential pathologic diagnosis. In patients with advanced PBC, a decrease in T4+ cells in the blood appeared to be accompanied by their accumulation in the portal triads. In contrast, T8+ cells accumulated preferentially around bile ducts. © 1984 Plenum Publishing Corporation

Thin Film Growth and Device Fabrication of Iron-Based Superconductors

Iron-based superconductors have received much attention as a new family of high-temperature superconductors owing to their unique properties and distinct differences from cuprates and conventional superconductors. This paper reviews progress in thin film research on iron-based superconductors since their discovery for each of five material systems with an emphasis on growth, physical properties, device fabrication, and relevant bulk material properties.Comment: To appear in J. Phys. Soc. Jp