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Soft supersymmetry breaking in KKLT flux compactification
Choi, K.,Falkowski, A.,Nilles, H.P.,Olechowski, M. Elsevier 2005 Nuclear physics, B Vol.718 No.1
<P><B>Abstract</B></P><P>We examine the structure of soft supersymmetry breaking terms in KKLT models of flux compactification with low energy supersymmetry. Moduli are stabilized by fluxes and nonperturbative dynamics while a de Sitter vacuum is obtained by adding supersymmetry breaking anti-branes. We discuss the characteristic pattern of mass scales in such a set-up as well as some features of 4D N=1 supergravity breakdown by anti-branes. Anomaly mediation is found to always give an important contribution and one can easily arrange for flavor-independent soft terms. In its most attractive realization, the modulus mediation is comparable to the anomaly mediation, yielding a quite distinctive sparticle spectrum. In addition, the axion component of the modulus/dilaton superfield dynamically cancels the relative CP phase between the contributions of anomaly and modulus mediation, thereby avoiding dangerous SUSY CP violation.</P>
SangHoon Lee,Kay Bidle,Paul Falkowski,David Marchant 한국해양과학기술원 2005 Ocean and Polar Research Vol.27 No.2
From ancient Antarctic glacier ice, we extracted total genomic DNA that was suitable for prokaryotic 16S rDNA gene cloning and sequencing, and bacterial artificial chromosome (BAC) library and end-sequencing. The ice samples were from the Dry Valley region. Age dating by 40Ar/39Ar analysis on the volcanic ashes deposited in situ indicated the ice samples are minimum 100,000-300,000 yr (sample DLE) and 8 million years (sample EME) old. Further assay proved the ice survived freeze-thaw cycles or other re-working processes. EME, which was from a small lobe of the basal Taylor glacier, is the oldest known ice on Earth. Microorganisms, preserved frozen in glacier ice and isolated from the rest of the world over a geological time scale, can provide valuable data or insight for the diversity, distribution, survival strategy, and evolutionary relationships to the extant relatives. From the 16S gene cloning study, we detected no PCR amplicons with Archaea-specific primers, however we found many phylotypes belonging to Bacteria divisions, such as Actinobacteria, Acidobacteria, Proteobacteria (a, b, and g), Firmicutes, and Cytophaga-Flavobacterium-Bacteroid. BAC cloning and sequencing revealed protein codings highly identical to phenylacetic acid degradation protein paaA, chromosome segregation ATPases, or cold shock protein B of present day bacteria. Throughput sequencing of the BAC clones is underway. Viable and culturable cells were recovered from the DLE sample, and characterized by their 16S rDNA sequences. Further investigation on the survivorship and functional genes from the past should help unveil the evolution of life on Earth, or elsewhere, if any.
Paulina Wiecinska,Agnieszka Zurawska,Pawel Falkowski,Dae‑Yong Jeong,Mikolaj Szafran 한국세라믹학회 2020 한국세라믹학회지 Vol.57 No.3
Herein, we present manifold possibilities of using saccharides and their derivatives in colloidal processing of ceramics. Sugarbased compounds are attractive alternatives for commonly used organic additives, because they are renewable materials, are non-toxic to human skin, and have a positive influence on the rheological behavior and stability of ceramic suspensions which is reflected in the properties of green and sintered bodies. The examined substances include sugar acids (galacturonic and lactobionic acid) as highly effective deflocculants for nanopowders; acryloyl derivatives of monosaccharides and sugar alcohols as organic monomers in gelcasting; polysaccharides as binders; and l-ascorbic acid as an activator of radical polymerization in gelcasting. The multifunctionality of the selected compounds as well as their thermal decomposition during sintering of ceramics is discussed. The study also reviews the related literature focusing on sugar-based compounds in ceramic processing.
Lee, Sang-Hoon,Bidle, Kay,Falkowski, Paul,Marchant, David Korea Institute of Ocean ScienceTechnology 2005 Ocean and Polar Research Vol.27 No.2
From ancient Antarctic glacier ice, we extracted total genomic DNA that was suitable for prokaryotic 16S rDNA gene cloning and sequencing, and bacterial artificial chromosome (BAC) library and end-sequencing. The ice samples were from the Dry Valley region. Age dating by $^{40}Ar/^{39}Ar$ analysis on the volcanic ashes deposited in situ indicated the ice samples are minimum 100,000-300,000 yr (sample DLE) and 8 million years (sample EME) old. Further assay proved the ice survived freeze-thaw cycles or other re-working processes. EME, which was from a small lobe of the basal Taylor glacier, is the oldest known ice on Earth. Microorganisms, preserved frozen in glacier ice and isolated from the rest of the world over a geological time scale, can provide valuable data or insight for the diversity, distribution, survival strategy, and evolutionary relationships to the extant relatives. From the 16S gene cloning study, we detected no PCR amplicons with Archaea-specific primers, however we found many phylotypes belonging to Bacteria divisions, such as Actinobacteria, Acidobacteria, Proteobacteria $({\alpha},\;{\beta},\;and\;{\gamma})$, Firmicutes, and Cytophaga-Flavobacterium-Bacteroid$. BAC cloning and sequencing revealed protein codings highly identical to phenylacetic acid degradation protein paaA, chromosome segregation ATPases, or cold shock protein B of present day bacteria. Throughput sequencing of the BAC clones is underway. Viable and culturable cells were recovered from the DLE sample, and characterized by their 16S rDNA sequences. Further investigation on the survivorship and functional genes from the past should help unveil the evolution of life on Earth, or elsewhere, if any.
The fate of photons absorbed by phytoplankton in the global ocean
Lin, Hanzhi,Kuzminov, Fedor I.,Park, Jisoo,Lee, SangHoon,Falkowski, Paul G.,Gorbunov, Maxim Y. American Association for the Advancement of Scienc 2016 Science Vol.351 No.6270
<P>Solar radiation absorbed by marine phytoplankton can follow three possible paths. By simultaneously measuring the quantum yields of photochemistry and chlorophyll fluorescence in situ, we calculate that, on average, similar to 60% of absorbed photons are converted to heat, only 35% are directed toward photochemical water splitting, and the rest are reemitted as fluorescence. The spatial pattern of fluorescence yields and lifetimes strongly suggests that photochemical energy conversion is physiologically limited by nutrients. Comparison of in situ fluorescence lifetimes with satellite retrievals of solar-induced fluorescence yields suggests that the mean values of the latter are generally representative of the photophysiological state of phytoplankton; however, the signal-to-noise ratio is unacceptably low in extremely oligotrophic regions, which constitute 30% of the open ocean.</P>
Park, Jisoo,Kuzminov, Fedor I.,Bailleul, Benjamin,Yang, Eun Jin,Lee, SangHoon,Falkowski, Paul G.,Gorbunov, Maxim Y. Wiley (John WileySons) 2017 Limnology and Oceanography Vol.62 No.5
<P>Amundsen Sea polynyas are among the most productive, yet climate-sensitive ecosystems in the Southern Ocean and host massive annual phytoplankton blooms. These blooms are believed to be controlled by iron fluxes from melting ice and icebergs and by intrusion of nutrient-rich Circumpolar Deep Water, however the interplay between iron effects and other controls, such as light availability, has not yet been quantified. Here, we examine phytoplankton photophysiology in relation to Fe stress and physical forcing in two largest polynyas, Amundsen Sea Polynya (ASP) and Pine Island Polynya (PIP), using the combination of high-resolution variable fluorescence measurements, fluorescence lifetime analysis, photosynthetic rates, and Feenrichment incubations. These analyses revealed strong Fe stress in the ASP, whereas the PIP showed virtually no signatures of Fe limitation. In spite of enhanced iron availability in the PIP, chlorophyll biomass remained similar to 30-50% lower than in the Fe-stressed ASP. This apparent paradox would not have been observed if iron were the main control of phytoplankton bloom in the Amundsen Sea. Long-term satellite-based climatology records revealed that the ASP is exposed to significantly higher solar irradiance levels throughout the summer season, as compared to the PIP region, suggesting that light availability controls the magnitude of phytoplankton blooms in the Amundsen Sea. Our data suggests that higher Fe availability (e.g., due to higher melting rates of ice sheets) would not necessarily increase primary productivity in this region. Furthermore, stronger wind-driven vertical mixing in expanding ice-free areas may lead to reduction in light availability and productivity in the future.</P>