Faster Compact On-Line Lempel-Ziv Factorization

We present a new on-line algorithm for computing the Lempel-Ziv factorization of a string that runs in $O(N\log N)$ time and uses only $O(N\log\sigma)$ bits of working space, where $N$ is the length of the string and $\sigma$ is the size of the alphabet. This is a notable improvement compared to the performance of previous on-line algorithms using the same order of working space but running in either $O(N\log^3N)$ time (Okanohara & Sadakane 2009) or $O(N\log^2N)$ time (Starikovskaya 2012). The key to our new algorithm is in the utilization of an elegant but less popular index structure called Directed Acyclic Word Graphs, or DAWGs (Blumer et al. 1985). We also present an opportunistic variant of our algorithm, which, given the run length encoding of size $m$ of a string of length $N$, computes the Lempel-Ziv factorization on-line, in $O\left(m \cdot \min \left\{\frac{(\log\log m)(\log \log N)}{\log\log\log N}, \sqrt{\frac{\log m}{\log \log m}} \right\}\right)$ time and $O(m\log N)$ bits of space, which is faster and more space efficient when the string is run-length compressible

Potential climate effects on Japanese rice productivity

Adaptation to climate change has become an important policy question in recent years. Agriculture is the economic activity most sensitive to climate change. We evaluate the dynamic effects of productivity change and individual efforts to adapt to climate change. Adaptation actions in agriculture are evaluated to determine how the climate affects production efficiency. In this paper, we use the bi-directional distance function method to measure Japanese rice production loss due to climate. We find that 1) accumulated precipitation has the greatest effect on rice production efficiency and 2) the climate effect on rice production efficiency decreases over time. Our results empirically support the benefit of an adaptation approach.Climate change, productivity analysis, agriculture

Mass Transport in Permeable Sediment Induced by Pressure Fluctuation at Sediment/Water Interface

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Mass spectrometry of hydrogen/deuterium exchange in 70S ribosomal proteins from E. coli

AbstractThe 70S ribosome from Escherichia coli is a supermacro complex (MW: 2.7MDa) comprising three RNA molecules and more than 50 proteins. We have for the first time successfully analyzed the flexibility of 70S ribosomal proteins in solution by detecting the hydrogen/deuterium exchange with mass spectrometry. Based on the deuterium incorporation map of the X-ray structure obtained at the time of each exchange, we demonstrate the structure–flexibility–function relationship of ribosome focusing on the deuterium incorporation of the proteins binding ligands (tRNA, mRNA, and elongation factor) and the relation with structural assembly processes

Formation of Methanofullerene Cation in Bulk Heterojunction Polymer Solar Cells Studied by Transient Absorption Spectroscopy

Photogenerated charge carriers for blend films of poly[2-methoxy-5-(3, 7-dimethyloctyloxy)-1, 4-phenylenevinylene] (MDMO-PPV) and [6, 6]-phenyl-C₆₁-butyric acid methyl ester (PCBM) have been investigated by transient absorption spectroscopy. The blend film with a low PCBM fraction ( 30 wt %) exhibits a major absorption band at ∼900 nm, which is characteristic of the PCBM radical cation. For identification of charge carriers, the absorption spectrum and molar absorption coefficient of each charged species have been evaluated separately using various combinations of electron donor and acceptor materials. Consequently, the MDMO-PPV hole polaron has been found to have a broad absorption at ∼950 nm and the PCBM radical anion and cation show a distinct absorption at 1020 and 890 nm, respectively. On the basis of these absorption spectra, the transient spectra observed for the blend films have been simulated. The spectrum for a low PCBM fraction is well reproduced by superposition of the absorption spectra of the MDMO-PPV hole polaron and PCBM radical anion. On the other hand, the spectrum for a high PCBM fraction is well reproduced by superposition of the absorption spectra of the MDMO-PPV hole polaron, PCBM radical anion, and PCBM radical cation, which indicates that the PCBM radical cation is formed in the blend films with PCBM at a high concentration. Possible mechanisms for the formation of the PCBM radical cation in the blend are also discussed

Alteration of chemokine production in bovine endometrial epithelial and stromal cells under heat stress conditions

After parturition, cows frequently develop uterine bacterial infections, resulting in the onset of endometritis. To eliminate the bacteria, bovine endometrial cells secrete chemokines, such as IL-6 and MCP1, which attract macrophages (M Phi s) to the subepithelial stroma. These attracted M Phi s are not only involved in bacterial elimination but also the orchestration of inflammation and tissue repair. These immune responses aid in the recovery from endometritis; however, the recovery from endometritis takes longer in summer than in any other season. Based on these findings, we hypothesized that heat stress (HS) affects the chemokine production in endometrial cells. To confirm this hypothesis, we compared IL-6 and MCP1 production induced by lipopolysaccharide (LPS) in bovine endometrial epithelial and stromal cells under normal (38.5 degrees C) and HS conditions (40.5 degrees C). In the endometrial epithelial cells, IL-6 production stimulated by LPS was significantly (p < .05) suppressed under HS conditions. MCP1 production in endometrial epithelial cells was not detected under both the control and HS conditions regardless of the presence of LPS. Moreover, LPS significantly (p < .05) stimulated IL-6 and MCP1 production in endometrial stromal cells. Moreover, HS significantly (p < .05) enhanced their production compared to that under the control conditions. In addition, HS did not affect the migration ability of M Phi s; however, the supernatant of the endometrial stromal cells cultured under the HS condition significantly (p < .05) attracted the M Phi s when compared to the control condition. These results suggest that HS disrupts chemokine production in two types of endometrial cells and alters the distribution of M Phi s in the endometrium during the summer

Formation Mechanism of Fullerene Cation in Bulk Heterojunction Polymer Solar Cells

The charge carrier dynamics in blend films of [6, 6]-phenyl-C₆₁-butyric acid methyl ester (PCBM) and conjugated polymers with different ionization potentials are measured using transient absorption spectroscopy to study the formation mechanism of PCBM radical cation, which was previously discovered for blend films of poly[2-methoxy-5-(3, 7-dimethyloctyloxy)-1, 4-phenylenevinylene] (MDMO-PPV) and PCBM. On a nanosecond time scale after photoexcitation, polymer hole polaron and PCBM radical anion are observed but no PCBM radical cation is found in the blends. Subsequently, the fraction of polymer hole polarons decreases and that of PCBM radical cations increases with time. Finally, the fraction of PCBM radical cations becomes constant on a microsecond time scale. The final fraction of PCBM radical cation is dependent on the ionization potential of polymers but independent of the excitation wavelength. These findings show that the formation of PCBM radical cation is due to hole injection from polymer to PCBM domains. Furthermore, the energetic conditions for such hole injection in polymer/PCBM blend films are discussed on the basis of Monte Carlo analysis for hole hopping in a disordered donor/acceptor heterojunction with varying energetic parameters

Role of Interfacial Charge Transfer State in Charge Generation and Recombination in Low-Bandgap Polymer Solar Cell

The charge carrier dynamics in blend films of poly[2, 6-(4, 4-bis(2-ethylhexyl)-4H-cyclopenta[2, 1-b;3, 4-b′]dithiophene)-alt-4, 7-(2, 1, 3-benzothiadiazole)] (PCPDTBT) and [6, 6]-phenyl-C₆₁-butyric acid methyl ester (PCBM) was studied by transient absorption spectroscopy in order to address the origin of limited external quantum efficiency (EQE) of this solar cell compared to that of a benchmark solar cell composed of regioregular poly(3-hexythiphene) (RR-P3HT) and PCBM. Upon photoexcitation, PCPDTBT singlet excitons promptly convert to the interfacial charge transfer (CT) state that is a Coulombically bound charge pair of PCPDTBT polaron and PCBM anion at the heterojunction with almost 100% efficiency in a picosecond. In other words, the exciton diffusion efficiency η[ED] and charge transfer efficiency η[CT] are 100% in this blend, which are higher than and comparable to those of the RR-P3HT/PCBM solar cell, respectively. On a time scale of nanoseconds, 70% of the PCPDTBT bound polarons are dissociated into free charge carriers, and the others recombine geminately to the ground state through the CT state. The charge dissociation efficiency η[CD] = 70% is lower than that of RR-P3HT/PCBM solar cells. The PCPDTBT dissociated polarons recombine bimolecularly on a time scale of nano- to microseconds with a charge lifetime of ∼10⁻⁷ s, which is shorter than that observed for RR-P3HT/PCBM blends. In summary, the lower charge dissociation efficiency and shorter charge lifetime are the limiting factors for the photovoltaic performance of PCPDTBT/PCBM solar cells. Furthermore, the origin of such limitation is also discussed in terms of the charge dissociation and recombination through the interfacial CT state in PCPDTBT/PCBM blends