Site-selective spectroscopy and level ordering in C-phycocyanin

We present a combined fluorescence and hole-burning study of the biliprotein C-phycocyanin. Sharp zero-phonon holes compare with a broad structureless fluorescence. This finding is rationalized in terms of the special level structure in this pigment, the fast energy-transfer processes and a lack of correlation of the energies of the emissive states

An optical linewidth study of a chromoprotein-C-phycocyanin in a low-temperature glass

The temperature dependence of spectral holes burnt into a phycocyanin-doped ethylene glycol/water glass is investigated in the temperature range between 1.5 and 15 K. The data are well described by a power law with an exponent of 1.16 ± 0.1. Chromoproteins thus behave very much the same as glasses doped with small impurity molecules

Detailed studies of the subpicosecond kinetics in the primary electron transfer of reaction centers of Rhodopseudomonas viridis

The primary, light-induced charge separation in reaction centers of Rhodopseudomonas viridis is investigated with femtosecond time resolution. The absorption changes after direct excitation of the primary donor P at 955 nm are investigated in the time range from 100 fs to 600 ps. The experimental data, taken at various probing wavelengths, reveal one subpicosecond and two picosecond time constants: 0.65 ± 0.2 ps, 3.5 ± 0.4 ps, and 200 ± 20 ps. The previously undetected 0.65 ps kinetics can be observed clearly in the spectral range of the Qx and Qy transitions of the monomeric bacteriochlorophylls. The experimental data support the idea that the accessory bacteriochlorophyll B A participates in the electron-transfer process. Reference

Peripheral Innate Immune Activation Correlates With Disease Severity in GRN Haploinsufficiency.

Objective: To investigate associations between peripheral innate immune activation and frontotemporal lobar degeneration (FTLD) in progranulin gene (GRN) haploinsufficiency. Methods: In this cross-sectional study, ELISA was used to measure six markers of innate immunity (sCD163, CCL18, LBP, sCD14, IL-18, and CRP) in plasma from 30 GRN mutation carriers (17 asymptomatic, 13 symptomatic) and 29 controls. Voxel based morphometry was used to model associations between marker levels and brain atrophy in mutation carriers relative to controls. Linear regression was used to model relationships between plasma marker levels with mean frontal white matter integrity [fractional anisotropy (FA)] and the FTLD modified Clinical Dementia Rating Scale sum of boxes score (FTLD-CDR SB). Results: Plasma sCD163 was higher in symptomatic GRN carriers [mean 321 ng/ml (SD 125)] compared to controls [mean 248 ng/ml (SD 58); p < 0.05]. Plasma CCL18 was higher in symptomatic GRN carriers [mean 56.9 pg/ml (SD 19)] compared to controls [mean 40.5 pg/ml (SD 14); p < 0.05]. Elevation of plasma LBP was associated with white matter atrophy in the right frontal pole and left inferior frontal gyrus (p FWE corrected <0.05) in all mutation carriers relative to controls. Plasma LBP levels inversely correlated with bilateral frontal white matter FA (R2 = 0.59, p = 0.009) in mutation carriers. Elevation in plasma was positively correlated with CDR-FTLD SB (b = 2.27 CDR units/μg LBP/ml plasma, R2 = 0.76, p = 0.003) in symptomatic carriers. Conclusion: FTLD-GRN is associated with elevations in peripheral biomarkers of macrophage-mediated innate immunity, including sCD163 and CCL18. Clinical disease severity and white matter integrity are correlated with blood LBP, suggesting a role for peripheral immune activation in FTLD-GRN

Criteria for the diagnosis of corticobasal degeneration

Current criteria for the clinical diagnosis of pathologically confirmed corticobasal degeneration (CBD) no longer reflect the expanding understanding of this disease and its clinicopathologic correlations. An international consortium of behavioral neurology, neuropsychology, and movement disorders specialists developed new criteria based on consensus and a systematic literature review. Clinical diagnoses (early or late) were identified for 267 nonoverlapping pathologically confirmed CBD cases from published reports and brain banks. Combined with consensus, 4 CBD phenotypes emerged: corticobasal syndrome (CBS), frontal behavioral-spatial syndrome (FBS), nonfluent/agrammatic variant of primary progressive aphasia (naPPA), and progressive supranuclear palsy syndrome (PSPS). Clinical features of CBD cases were extracted from descriptions of 209 brain bank and published patients, providing a comprehensive description of CBD and correcting common misconceptions. Clinical CBD phenotypes and features were combined to create 2 sets of criteria: more specific clinical research criteria for probable CBD and broader criteria for possible CBD that are more inclusive but have a higher chance to detect other tau-based pathologies. Probable CBD criteria require insidious onset and gradual progression for at least 1 year, age at onset ≥50 years, no similar family history or known tau mutations, and a clinical phenotype of probable CBS or either FBS or naPPA with at least 1 CBS feature. The possible CBD category uses similar criteria but has no restrictions on age or family history, allows tau mutations, permits less rigorous phenotype fulfillment, and includes a PSPS phenotype. Future validation and refinement of the proposed criteria are needed

Modified bacterial reaction centers

Pigments of borohydride-treated reaction centers of Rhodobacter sphaeroides R 26 and Rhodopseudomonas viridis were analyzed by HPLC with polychromatic detection. In both species, pigment composition and contents were unchanged. Reaction centers from Rhodobacter sphaeroides R26 were prepared in which bacteriochlorophylls (BA,B) and bacteriopheophytins (HA,B) were exchanged with their potential borohydride products reduced at C-31. [3-Hydroxyethyl]-BChl a exchanges selectively into the BA,B pockets, and 31-OH-BPh a to the HA,B pockets. Stable reaction centers are obtained in both cases. A comparison of the absorption and circular dichroism spectra of reaction centers after exchange with 31-OH pigments, and of borohydride-modified reaction centers, reveal distinct differences. It is concluded that during borohydride reduction none of the pigments is chemically modified or extracted from the reaction centers

A linguistic analysis of lying in negative evaluations: The speech act performance of Chinese learners of Korean

이 논문은 중국인 한국어 학습자와 한국어 화자들 사이의 ‘거짓말’ 화행 양상을 언어학적으로 분석한 연구이다. 여기서 말하는 ‘거짓말’이란 요청, 사과, 거절 등과 같은 화행의 일종으로서 ‘부정적 평가’에 속하며 대화 참여자나 상황을 고려한 소위 ‘선의의 거짓말’을 가리키는 것으로 이해할 수 있을 것이다. 우리는 중국인 한국어 학습자 15명과 한국어 화자 15명을 대상으로 담화완성테스트(DCT)와 부연설명질문지(QFE)를 사용하여 피실험자들의 화행을 분석하였다. 피실험자 자신들의 설명과 한국어교육 전문가 다섯 명의 판정을 종합해 ‘거짓말’ 화행을 가려내고 통계 처리를 바탕으로 다음과 같은 결론에 도달했다. 한국어 화자들이 중국인 한국어 학습자들보다 (선의의) 거짓말을 더 많이 수행하는 것으로 나타났다. 그리고 두 집단 모두 부정적 평가가 사물에 관련된 경우보다 사람에 관련된 경우에 ‘거짓말’ 화행을 더 많이 사용한다. 그러나 화자와 청자 사이의 친소관계(distance)나 상하관계(power)는 거짓말 사용에 직접적 상관 관계를 보여주지 않았다. 이 연구는 지금까지 화행 연구 중에서 상대적으로 연구가 부진했던 부정평가와 ‘거짓말’ 화행에 대한 분석을 시도했다는 점에서 의미가 있다. 또한 한국어 화자와 중국인 한국어 학습자 사이에 보이는 화행 수행의 차이를 문화인식(cultural awareness)의 관점에서 해석해 볼 수 있는 가능성도 열어 주었다