This paper applies the categories from an opinion annotation scheme developed for monologue text to the genre of multiparty meetings. We describe modifications to the coding guidelines that were required to extend the categories to the new type of data, and present the results of an inter-annotator agreement study. As researchers have found with other types of annotations in speech data, inter-annotator agreement is higher when the annotators both read and listen to the data than when they only read the transcripts. Previous work exploited prosodic clues to perform automatic detection of speaker emotion (Liscombe et al. 2003). Our findings suggest that doing so to recognize opinion categories would be a promising line of work.

In 2006, IBM participated for the first time in the Enterprise Track, submitting runs for both the discussion and expert tasks. The Enterprise Track is intended to address information seeking tasks common in corporate settings using information that is readily available on corporate intranets. Because of confidentiality issues, the corpus used for this task is a snapshot of w3c.org as of June 2004, considering the W3C as a “corporation” that conducts its dayto-day business on the web. This corpus consists of a heterogeneous set of data sources, including web pages, mailing lists, code, wiki, etc. [Craswell et al. 2006]. The discussion task seeks e-mail messages that discuss the pro or con of a given subject matter, while the expert task requires that experts for given topics be identified.

OpinionFinder is a system that performs subjectivity analysis, automatically identifying when opinions, sentiments, speculations, and other private states are present in text. Specifically, OpinionFinder aims to identify subjective sentences and to mark various aspects of the subjectivity in these sentences, including the source (holder) of the subjectivity and words that are included in phrases expressing positive or negative sentiments.

A gene of the unicellular cyanobacterium Synechocystis sp strain PCC 6803 that is homologous to the conserved chlo- roplast open reading frame orf784 has been cloned and sequenced. The nucleotide sequence of the gene predicts a protein of 184 amino acids with a calculated molecular mass of 21.5 kD and two membrane-spanning regions. Amino acid sequence analysis showed 46 to 37% homology of the cyanobacterial orf784 with tobacco orf784, rice orf785, liver- wort orf184, and Euglena gracilis orf206 sequences. Two orf784-specific mutants of Synechocystis sp PCC 6803 were constructed by insertion mutagenesis. Cells of mutants showed growth characteristics similar to those of the wild type. Their pigment composition was distinctly different from the wild type, as indicated by an increase in the phycocyanin-to- chlorophyll ratio. In addition, mutants also had a two- to threefold increase in photosynthetic electron transfer rates as well as in photosystem Il-to-photosystem I ratio-a phenomenon hitherto not reported for mutants with altered pho- tosynthetic characteristics. The observed alterations in the orfl84-specific mutants provide strong evidence for a functional role of the orf784 gene product in photosynthetic processes.

A gene of the unicellular cyanobacterium Synechocystis sp strain PCC 6803 that is homologous to the conserved chloroplast open reading frame orf184 has been cloned and sequenced. The nucleotide sequence of the gene predicts a protein of 184 amino acids with a calculated molecular mass of 21.5 kD and two membrane-spanning regions. Amino acid sequence analysis showed 46 to 37% homology of the cyanobacterial orf184 with tobacco orf184, rice orf185, liverwort orf184, and Euglena gracilis orf206 sequences. Two orf184-specific mutants of Synechocystis sp PCC 6803 were constructed by insertion mutagenesis. Cells of mutants showed growth characteristics similar to those of the wild type. Their pigment composition was distinctly different from the wild type, as indicated by an increase in the phycocyanin-to-chlorophyll ratio. In addition, mutants also had a two- to threefold increase in photosynthetic electron transfer rates as well as in photosystem II-to-photosystem I ratio-a phenomenon hitherto not reported for mutants with altered photosynthetic characteristics. The observed alterations in the orf184-specific mutants provide strong evidence for a functional role of the orf184 gene product in photosynthetic processes.

A functionally intact light-harvesting complex II (LHC II) was recently inferred to be involved in the induction of high-energy-dependent chlorophyll (Chl) fluorescence quenching (qE) in leaves (Lokstein et al., J. Photochem. Photobiol. B: Biol, 19 (1993) 217-225). The present study was performed to further elucidate this finding and, in particular to analyze the role of the xanthophyll cycle for qE formation. Measurements of modulated Chl fluorescence using the saturating flash technique and of xanthophyll cycle activity were performed in barley leaves of wild type (WT) and a Chl-b-less mutant with reduced LHC II (chlorina 3613) in the absence and presence of the violaxanthin (V) de-epoxidase inhibitor dithiothreitol (DTT).The results can be summarized as follows: (a) The content of xanthophyll cycle-constituents in mutant leaves is lower on a leaf area basis (but significantly higher when related to Chl a content); the mutant has a substantially higher ability to convert V into antheraxanthin (A) and zeaxanthin (Z) when compared with the WT. In both genotypes in response to DTT treatment only low levels of A accumulated and Z formation was almost completely suppressed. (b) The photochemical efficiency of photosystem (PS) II expressed as the ratio of variable to maximum fluorescence, F-V/F-M, in dark-adapted leaves is virtually the same in WT and the mutant and remains invariant to treatment with DTT. (c) Nearly complete abolishment of the 'fast' relaxation phase of non-photochemical quenching (qNf) was observed after DTT treatment. Suppression of qNf (as an approximate measure of qE) accompanied by the disappearance of a 'rapid' phase of F-O quenching relaxation provides strong evidence for qE being an antenna associated phenomenon. (d) A 'medium' phase of qN relaxation (qNm) was not influenced by DTT treatment at all light intensities investigated. Thus, the results do not indicate a significant contribution of persisting xanthophyll-dependent (A+Z) quenching to qNm. The phenomenon of qNm can not be explained by chloroplast movements.The data obtained support the hypothesis that Delta pH-mediated synergistic operation of both, structural rearrangement of LHC II and xanthophyll-cycle activity, is required for efficient qE formation in vivo.

A pulse amplitude-modulated fluorometric technique was employed to separate photochemical (qP) and non-photochemical (qN) chlorophyll fluorescence quenching in attached leaves of wild-type and a chlorophyll-b-less mutant of barley (Hordeum vulgare L.). Whereas a significantly higher qN developed in the wild type in the intensity range at which the photosynthetic light response became non-linear, there were virtually no differences in qP until pronounced photoinhibition was apparent. On monitoring the “dark” recovery of the maximum (FM) and dark level (F0) fluorescence yield, three distinct kinetic phases were resolved, which are ascribed to relaxation of high energy state quenching (qE), state 1-state 2 transitions (qT) and quenching due to photoinhibition (qI). The results provide evidence for heterogeneity of qE. The major part of qE (related to a fast-relaxing phase of FM quenching) is strongly reduced in mutant leaves. A fast-relaxing phase of F0 quenching, readily observed in wild-type leaves under high light, is absent in the mutant under the same conditions. Hence, qE appears to be associated with the photosystem II light-harvesting complex (LHC II). A medium component of “dark” relaxation kinetics was observed in both mutant and wild-type leaves. However, it appears attributable to qT only in the latter at low light. Supported by the finding that there was no difference in xanthophyll pool size (on a chlorophyll a basis) between wild type and mutant, under high light conditions the medium phase may reflect a slower-relaxing portion of qE, probably due to xanthophyll conversion. Under supersaturating light the very slowly relaxing qI component became dominating, affecting mutant leaves to a considerably greater extent. The results stress the key role of LHC II not only as a solar energy collector but also in protecting the photosynthetic apparatus from adverse effects of excess excitation input.

Application of 10−2 M CCC-solution in etiolated primary leaves of Triticum aestivum L. during illumination causes reduced chlorophyll formation and retardation of chloroplast development. After 24 h CCC-treated leaves do not reach the O2-compensation point; in the dark their O2-consumption is higher than in water controls. The activity of chloroplastic NADP-GAPDH and of reductive pentose phosphate cycle has decreased. Concomitantly the activity of NAD-GAPDH arises. The ATP-content as well as the energy charge is maintained. The enzyms studied and the adenylate systems are considered as two essential components of the intercellular regulatory system between heterotrophic and autotrophic metabolism which guarantees the need of energy under different conditions.