196 research outputs found

    Quivers of monoids with basic algebras

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    We compute the quiver of any monoid that has a basic algebra over an algebraically closed field of characteristic zero. More generally, we reduce the computation of the quiver over a splitting field of a class of monoids that we term rectangular monoids (in the semigroup theory literature the class is known as DO\mathbf{DO}) to representation theoretic computations for group algebras of maximal subgroups. Hence in good characteristic for the maximal subgroups, this gives an essentially complete computation. Since groups are examples of rectangular monoids, we cannot hope to do better than this. For the subclass of R\mathscr R-trivial monoids, we also provide a semigroup theoretic description of the projective indecomposables and compute the Cartan matrix.Comment: Minor corrections and improvements to exposition were made. Some theorem statements were simplified. Also we made a language change. Several of our results are more naturally expressed using the language of Karoubi envelopes and irreducible morphisms. There are no substantial changes in actual result

    Hypoxia during maintenance hemodialysis; the critical role of pH

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    Background The impact and management of subclinical hypoxia during hemodialysis is a significant medical challenge. As key determinants of O2 availability and delivery, proposed mechanisms contributing to hypoxia include ischemia, alkalemia and pulmonary leukocyte sequestration. However, no study has comprehensively investigated and compared these interrelated mechanisms throughout a typical hemodialysis treatment week. This study aimed to comprehensively assess the physiological mechanisms that contribute to hypoxia during hemodialysis. Methods In 76 patients, we measured arterial blood gases and pH at four time-points during hemodialysis (start, 15 min, 60 min, end) over the course of a standard treatment week. For the mid-week hemodialysis session, we additionally measured central hemodynamics (non-invasive cardiac output monitoring) and white blood cell count. Results Linear regression modelling identified changes in pH, but not central hemodynamics or white blood cell count, to be predictive of changes in PaO2 throughout hemodialysis (e.g. at 60 min, β standardized coefficient pH = 0.45, model R2 = 0.25, P < .001). Alkalemia, hypokalemia, decreased calcium and increased hemoglobin–O2 affinity (leftward shift in the oxyhemoglobin dissociation curve) were evident at the end of hemodialysis. pH and hemoglobin–O2 affinity at the start of hemodialysis increased incrementally over the course of a standard treatment week. Conclusion These data highlight the important role of pH in regulating O2 availability and delivery during hemodialysis. Findings support routine pH monitoring and personalized dialysate bicarbonate prescription to mitigate the significant risk of alkalemia and subclinical hypoxia

    On the Tail of the Scottish Vowel Length Rule in Glasgow

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    One of the most famous sound features of Scottish English is the short/long timing alternation of /i u ai/vowels, which depends on the morpho-phonemic environment, and is known of as the Scottish Vowel Length Rule (SVLR). These alternations make the status of vowel quantity in Scottish English (quasi-)phonemic but are also susceptible to change, particularly in situations of intense sustained dialect contact with Anglo-English. Does the SVLR change in Glasgow where dialect contact at the community level is comparably low? The present study sets out to tackle this question, and tests two hypotheses involving (1) external influences due to dialect-contact and (2) internal, prosodically-induced factors of sound change. Durational analyses of /i u a/ were conducted on a corpus of spontaneous Glaswegian speech from the 1970s and 2000s, and four speaker groups were compared, two of middle-aged men, and two of adolescent boys. Our hypothesis that the development of the SVLR over time may be internally constrained and interact with prosody was largely confirmed. We observed weakening effects in its implementation which were localised in phrase-medial unaccented positions in all speaker groups, and in phrase-final positions in the speakers born after the Second World War. But unlike some other varieties of Scottish or Northern English which show weakening of the Rule under a prolonged contact with Anglo-English, dialect contact seems to be having less impact on the durational patterns in Glaswegian vernacular, probably because of the overall reduced potential for a regular, everyday contact in the West given the different demographies

    The Turtle Garden: Tan Kah Kee’s last spiritual world

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    This paper explores the role of diasporic subjects in China’s heritage-making through a case study of the Turtle Garden built by Tan Kah Kee in Xiamen, China. Tan is the first person with Overseas Chinese background who built museums in the P.R. China and has been regarded as a symbol of Overseas Chinese patriotism. This paper argues that the Turtle Garden, conceptualised as a postcolonial ‘carnivalesque’ space, is more than a civic museum for public education. It reflects the owner’s highly complex and sometimes conflicting museum outlook embedded in his life experience as a migrant, his encounter with (British) colonialism in Malaya, and integrated with his desire and despair about the Chinese Communist Party’s nation-building project in the 1950s. Rather than a sign of devotion to the socialist motherland as simplistically depicted in China’s discourse, the garden symbolises Tan’s last ‘spiritual world’ where he simultaneously engaged with soul-searching as a returned Overseas Chinese and alternative diasporic imagining of Chinese identities and nation. It brings to light the value of heritage-making outside centralised heritage discourses, and offers an invaluable analytical lens to disentangle the contested and ever shifting relationship between diasporic subjects, cultural heritage and nation-(re)building in the Chinese context and beyond

    West African languages enrich the frequency code: Multi-functional pitch and multi-dimensional prosody in Ikaan polar questions

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    Cross-linguistically, statements tend to be pronounced with low or falling pitch and questions with high or rising pitch, a form–meaning pairing which has been attributed to the frequency code (Ohala, 1984). In many West African languages, however, questions are marked with a ‘lax’ prosody comprising falling intonation, low tones, lengthening, breathy termination, and open vowels (Rialland, 2007). This paper presents prosody findings from Ikaan (Niger-Congo; ISO 639-3: kcf) and proposes a re-analysis of the West African lax question prosody to integrate it with the frequency code model. The paper shows that the pragmatic functions of statement and polar question are expressed prosodically in Ikaan. Audio recordings of statements and morphosyntactically identical polar questions by six speakers were annotated segmentally, tonally, and for the presence of prosodic question markers. Speakers mark questions by using higher onset pitch, wider drops to final low tones, final breathy voice and voicelessness, final vowel lengthening, vowel insertion, and increased intensity. Breathiness may further contrast with creaky voice and glottal stops in statements. Phonation mode, and the accompanying vowel lengthening and insertion, are argued to indicate friendliness and appeals for collaboration, linking phonation mode to similar functions of higher pitch in the frequency code
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