Models and measurements of energy-dependent quenching.

Energy-dependent quenching (qE) in photosystem II (PSII) is a pH-dependent response that enables plants to regulate light harvesting in response to rapid fluctuations in light intensity. In this review, we aim to provide a physical picture for understanding the interplay between the triggering of qE by a pH gradient across the thylakoid membrane and subsequent changes in PSII. We discuss how these changes alter the energy transfer network of chlorophyll in the grana membrane and allow it to switch between an unquenched and quenched state. Within this conceptual framework, we describe the biochemical and spectroscopic measurements and models that have been used to understand the mechanism of qE in plants with a focus on measurements of samples that perform qE in response to light. In addition, we address the outstanding questions and challenges in the field. One of the current challenges in gaining a full understanding of qE is the difficulty in simultaneously measuring both the photophysical mechanism of quenching and the physiological state of the thylakoid membrane. We suggest that new experimental and modeling efforts that can monitor the many processes that occur on multiple timescales and length scales will be important for elucidating the quantitative details of the mechanism of qE

Pharyngealization in Chechen is gutturalization

Proceedings of the 37th Annual Meeting of the Berkeley Linguistics Society: Special Session on Languages of the Caucasus (2013), pp. 81-9

An Emergent Approach to the Guttural Natural Class

The post-velar consonants (uvulars, pharyngeals/epiglottals, glottals) have been argued to form an innate and universal phonological natural class (e.g. by McCarthy 1994). Under this hypothesis, languages should have an equal likelihood of showing evidence for the guttural natural class regardless of which post-velar consonants are present in each language. However, typological evidence from P-base (Mielke, 2008) shows that languages with pharyngeal consonants are significantly more likely to show such evidence than languages with just uvulars and glottals. This paper argues that the reason that languages with pharyngeals are more likely to show evidence of the guttural natural class is that pharyngeals are able to pull other consonants into phonologically patterning with them for both articulatory and acoustic reasons. The epilaryngeal constriction used in pharyngeal consonants facilitates articulatory links with uvulars and glottals. The acoustic effects of pharyngeals and uvulars on adjacent vowels are also similar, providing another means for these segments to pattern together phonologically. A preliminary analysis in Optimality Theory of the effects of post-velars on vowels is proposed in which markedness constraints refer to similarity scales that relate post-velar consonants to vowels. The guttural natural class, rather than being innate, emerges from phonological patterns with phonetic underpinnings

Models and measurements of energy-dependent quenching

Energy-dependent quenching (qE) in photosystem II (PSII) is a pH-dependent response that enables plants to regulate light harvesting in response to rapid fluctuations in light intensity. In this review, we aim to provide a physical picture for understanding the interplay between the triggering of qE by a pH gradient across the thylakoid membrane and subsequent changes in PSII. We discuss how these changes alter the energy transfer network of chlorophyll in the grana membrane and allow it to switch between an unquenched and quenched state. Within this conceptual framework, we describe the biochemical and spectroscopic measurements and models that have been used to understand the mechanism of qE in plants with a focus on measurements of samples that perform qE in response to light. In addition, we address the outstanding questions and challenges in the field. One of the current challenges in gaining a full understanding of qE is the difficulty in simultaneously measuring both the photophysical mechanism of quenching and the physiological state of the thylakoid membrane. We suggest that new experimental and modeling efforts that can monitor the many processes that occur on multiple timescales and length scales will be important for elucidating the quantitative details of the mechanism of qE

An Emergent Approach to the Guttural Natural Class

The post-velar consonants (uvulars, pharyngeals/epiglottals, glottals) have been argued to form an innate and universal phonological natural class (e.g. by McCarthy 1994). Under this hypothesis, languages should have an equal likelihood of showing evidence for the guttural natural class regardless of which post-velar consonants are present in each language. However, typological evidence from P-base (Mielke, 2008) shows that languages with pharyngeal consonants are significantly more likely to show such evidence than languages with just uvulars and glottals. This paper argues that the reason that languages with pharyngeals are more likely to show evidence of the guttural natural class is that pharyngeals are able to pull other consonants into phonologically patterning with them for both articulatory and acoustic reasons. The epilaryngeal constriction used in pharyngeal consonants facilitates articulatory links with uvulars and glottals. The acoustic effects of pharyngeals and uvulars on adjacent vowels are also similar, providing another means for these segments to pattern together phonologically. A preliminary analysis in Optimality Theory of the effects of post-velars on vowels is proposed in which markedness constraints refer to similarity scales that relate post-velar consonants to vowels. The guttural natural class, rather than being innate, emerges from phonological patterns with phonetic underpinnings

Pharyngealization in Chechen is Gutturalization

Proceedings of the 37th Annual Meeting of the Berkeley Linguistics Society: Special Session on Languages of the Caucasus (2013), pp. 81-95</jats:p