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Simultaneous coupling of phototaxis and electrotaxis in Volvox algae
In nature, living creatures are affected by several stimuli simultaneously. The response of living creatures to stimuli is called taxis. In order to reveal the principles of taxis behavior in response to complex stimuli, we simultaneously applied photostimulation and electric stimulation perpendicularly to a Volvox algae solution. The probability distribution of the swimming direction showed that a large population of swimming cells moved in a direction that was the result of the composition of phototaxis and electrotaxis. More surprisingly, we uncovered the coupling of signs of taxis, i.e., coupling of phototaxis and electrotaxis induced positive electrotaxis, which did not emerge in the single stimulation experiments. We qualitatively explained the coupling of taxis based on the polarization of the swimming cells induced by the simultaneous photo- and electric stimulation
Role of hydrophobic interaction in hapten-antibody binding
The precipitation reaction of bovine serum albumin coupled with p-azophenylleucine with homologous antibody was inhibited by several structurally related haptens. The isobutyl group substituent on alpha-carbon atom of the leucine residue contributed more than -5.8 Kcal/mol to the free energy of binding. This value was consistent with the free energy change expected from the transfer of n-butane from an aqueous environment to liquid n-butane. The observed contribution was explained, in terms of the hydrophobic interaction of the isobutyl group with the antigen binding site of the antibody molecule. These results were also compared with other hapten-antibody systems.</p
Cosmic Star Formation Activity at z=2.2 Probed by H-alpha Emission Line Galaxies
We present a pilot narrow-band survey of H-alpha emitters at z=2.2 in the
Great Observatories Origins Deep Survey North (GOODS-N) field with MOIRCS
instrument on the Subaru telescope. The survey reached a 3 sigma limiting
magnitude of 23.6 (NB209) which corresponds to a 3 sigma limiting line flux of
2.5 x 10^-17 erg s^-1 cm^-2 over a 56 arcmnin^2 contiguous area (excluding a
shallower area). From this survey, we have identified 11 H-alpha emitters and
one AGN at z=2.2 on the basis of narrow-band excesses and photometric
redshifts. We obtained spectra for seven new objects among them, including one
AGN, and an emission line above 3 sigma is detected from all of them. We have
estimated star formation rates (SFR) and stellar masses (M_star) for individual
galaxies. The average SFR and M_star is 27.8M_solar yr^-1 and 4.0 x
10^10M_solar, respectivly. Their specific star formation rates are inversely
correlated with their stellar masses. Fitting to a Schechter function yields
the H-alpha luminosity function with log L = 42.82, log phi = -2.78 and alpha =
-1.37. The average star formation rate density in the survey volume is
estimated to be 0.31M_solar yr^-1Mpc^-3 according to the Kennicutt relation
between H-alpha luminosity and star formation rate. We compare our H-alpha
emitters at z=2.2 in GOODS-N with narrow-band line emitters in other field and
clusters to see their time evolution and environmental dependence. We find that
the star formation activity is reduced rapidly from z=2.5 to z=0.8 in the
cluster environment, while it is only moderately changed in the field
environment. This result suggests that the timescale of galaxy formation is
different among different environments, and the star forming activities in high
density regions eventually overtake those in lower density regions as a
consequence of "galaxy formation bias" at high redshifts.Comment: Accepted for publication in PASJ Subaru Special Issue, 11 pages, 10
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Think Globally, Embed Locally - Locally Linear Meta-embedding of Words
Distributed word embeddings have shown superior performances in numerous
Natural Language Processing (NLP) tasks. However, their performances vary
significantly across different tasks, implying that the word embeddings learnt
by those methods capture complementary aspects of lexical semantics. Therefore,
we believe that it is important to combine the existing word embeddings to
produce more accurate and complete \emph{meta-embeddings} of words. For this
purpose, we propose an unsupervised locally linear meta-embedding learning
method that takes pre-trained word embeddings as the input, and produces more
accurate meta embeddings. Unlike previously proposed meta-embedding learning
methods that learn a global projection over all words in a vocabulary, our
proposed method is sensitive to the differences in local neighbourhoods of the
individual source word embeddings. Moreover, we show that vector concatenation,
a previously proposed highly competitive baseline approach for integrating word
embeddings, can be derived as a special case of the proposed method.
Experimental results on semantic similarity, word analogy, relation
classification, and short-text classification tasks show that our
meta-embeddings to significantly outperform prior methods in several benchmark
datasets, establishing a new state of the art for meta-embeddings
Learning Linear Transformations between Counting-based and Prediction-based Word Embeddings
Despite the growing interest in prediction-based word embedding learning methods, it remains unclear as to how the vector spaces learnt by the prediction-based methods differ from that of the counting-based methods, or whether one can be transformed into the other. To study the relationship between counting-based and prediction-based embeddings, we propose a method for learning a linear transformation between two given sets of word embeddings. Our proposal contributes to the word embedding learning research in three ways: (a) we propose an efficient method to learn a linear transformation between two sets of word embeddings, (b) using the transformation learnt in (a), we empirically show that it is possible to predict distributed word embeddings for novel unseen words, and (c) empirically it is possible to linearly transform counting-based embeddings to prediction-based embeddings, for frequent words, different POS categories, and varying degrees of ambiguities
Constructive Conflict Management in Organizations:Resolution Strategies, Goal Achievement, and Psychological Changes After Conflicts
Thermospermine suppresses auxin-inducible xylem differentiation in Arabidopsis thaliana
Thermospermine, a structural isomer of spermine, is synthesized by a thermospermine synthase designated ACAULIS5 (ACL5). Thermospermine-deficient acl5 mutant of Arabidopsis thaliana shows severe dwarfism and excessive xylem differentiation. By screening for compounds that affect xylem differentiation in the acl5 mutant, we identified auxin analogs that remarkably enhanced xylem vessel differentiation in the acl5 mutant but not in the wild type. The xylem-inducing effect of auxin analogs was clearly suppressed by thermospermine, indicating that auxin-inducible xylem differentiation is normally limited by thermospermine. Here, we further characterized xylem-inducing effect of auxin analogs in various organs. Auxin analogs promoted protoxylem differentiation in roots and cotyledons in the acl5 mutant. Our results indicate that the opposite action between thermospermine and auxin in xylem differentiation is common in different organs and also suggest that thermospermine might be required for the suppression of protoxylem differentiation
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