The Tick-Tock of Language: Is Language Processing Sensitive to Circadian Rhythmicity and Elevated Sleep Pressure?

The master circadian pacemaker emits signals that trigger organ-specific oscillators and, therefore, constitutes a basic biological process that enables organisms to anticipate daily environmental changes by adjusting behavior, physiology, and gene regulation. Although circadian rhythms are well characterized on a physiological level, little is known about circadian modulations of higher cognitive functions. Thus, we investigated circadian repercussions on language performance at the level of minimal syntactic processing by means of German noun phrases in ten young healthy men under the unmasking conditions of a 40 h constant-routine protocol. Language performance for both congruent and incongruent noun phrases displayed a clear diurnal rhythm with a peak performance decrement during the biological night. The nadirs, however, differed such that worst syntactic processing of incongruent noun phrases occurred 3 h earlier (07:00 h) than that of congruent noun phrases (10:00 h). Our results indicate that language performance displays an internally generated circadian rhythmicity with optimal time for parsing language between 3 to 6 h after the habitual wake time, which usually corresponds to 10:00–13:00 h. These results may have important ramifications for establishing optimal times for shiftwork changes or testing linguistically impaired people.     

Assembly of the barley light-harvesting chlorophyll a/b proteins in barley etiochloroplasts involves processing of the precursor on thylakoids

A barley gene encoding the major light-harvesting chlorophyll a/b-binding protein (LHCP) has been sequenced and then expressed in vitro to produce a labelled LHCP precursor (pLHCP). When barley etiochloroplasts are incubated with this pLHCP, both labelled pLHCP and LHCP are found as integral thylakoid membrane proteins, incorporated into the major pigment-protein complex of the thylakoids. The presence of pLHCP in thylakoids and its proportion with respect to labelled LHCP depends on the developmental stage of the plastids used to study the import of pLHCP. The reduced amounts of chlorophyll in a chlorophyll b-less mutant of barley does not affect the proportion of pLHCP to LHCP found in the thylakoids when import of pLHCP into plastids isolated from the mutant plants is examined. Therefore, insufficient chlorophyll during early stages of plastid development does not seem to be responsible for their relative inefficiency in assembling pLHCP. A chase of labelled pLHCP that has been incorporated into the thylakoids of intact plastids, by further incubation of the plastids with unlabelled pLHCP, reveals that the pLHCP incorporated into the thylakoids can be processed to its mature size. Our observations strongly support the hypothesis that after import into plastids, pLHCP is inserted into thylakoids and then processed to its mature size under in vivo conditions.     

Unity of measurement and motion

Issues addressed in H.H. Pattee's origin of life laboratory in the 1960s and their connection to the physics–evolution–language problematic are indicated. The problem of quantum measurement played a central role. The problem is herein examined in the light of the fluctuon model; in particular, as the model applies to gravity. The main conclusion is that measurement and motion are a unitary process. All accelerations are accompanied by a cycle involving the annihilation and creation of superpositions. Gravitational collapse is also a cyclic process in the fluctuon model. By a suitable transformation, it can be seen that interactions underlying superpositional collapse are the same as those operative in gravitational collapse. Implications for the origin of cellular life and the development of symbolic systems are considered.     

Yeast Lipids: Extraction,Quality Analysis,and Acceptability

Abstract

While a class of yeasts excrete lipid-containing surfactants, oleaginous yeasts produce and store lipids similar to vegetable oils and fats. Recovery of the oleaginous yeast lipids is problematic because of their intracellular nature and protection by well-knit biopolymers of the cell wall and other membrane systems. There is no suitable method of choice that ensures 100% recovery of intracellular lipids without affecting the native state during different unit operations. Several laboratory methods are available, but none can be adopted directly for commercial extractions due to technological limitations. However, as a result of the emergence of new downstream processing techniques, there is a positive indication for commercialization of yeast-lipid production in the future. Although most of the oleaginous yeasts are nonpathogenic, it is mandatory to analyze and report quality as well as toxicity of their lipids prior to market introduction as a component of human diet. This warrants specially formulated codes for edibility of yeast lipids and, in general, for similar products from other microbial sources.     

Switching between forest and trees: Opposite relationship of progesterone and testosterone to global–local processing

Sex differences in attentional selection of global and local components of stimuli have been hypothesized to underlie sex differences in cognitive strategy choice. A Navon figure paradigm was employed in 32 men, 41 naturally cycling women (22 follicular, 19 luteal) and 19 users of oral contraceptives (OCs) containing first to third generation progestins in their active pill phase. Participants were first asked to detect targets at any level (divided attention) and then at either the global or the local level only (focused attention). In the focused attention condition, luteal women showed reduced global advantage (i.e. faster responses to global vs. local targets) compared to men, follicular women and OC users. Accordingly, global advantage during the focused attention condition related significantly positively to testosterone levels and significantly negatively to progesterone, but not estradiol levels in a multiple regression model including all naturally cycling women and men. Interference (i.e. delayed rejection of stimuli displaying targets at the non-attended level) was significantly enhanced in OC users as compared to naturally cycling women and related positively to testosterone levels in all naturally cycling women and men. Remarkably, when analyzed separately for each group, the relationship of testosterone to global advantage and interference was reversed in women during their luteal phase as opposed to men and women during their follicular phase. As global processing is lateralized to the right and local processing to the left hemisphere, we speculate that these effects stem from a testosterone-mediated enhancement of right-hemisphere functioning as well as progesterone-mediated inter-hemispheric decoupling.     

3′-5′ tRNA guanylyltransferase in bacteria

The identity of the histidine specific transfer RNA (tRNA^His) is largely determined by a unique guanosine residue at position −1. In eukaryotes and archaea, the tRNA^His guanylyltransferase (Thg1) catalyzes 3′-5′ addition of G to the 5′-terminus of tRNA^His. Here, we show that Thg1 also occurs in bacteria. We demonstrate in vitro Thg1 activity for recombinant enzymes from the two bacteria Bacillus thuringiensis and Myxococcus xanthus and provide a closer investigation of several archaeal Thg1. The reaction mechanism of prokaryotic Thg1 differs from eukaryotic enzymes, as it does not require ATP. Complementation of a yeast thg1 knockout strain with bacterial Thg1 verified in vivo activity and suggests a relaxed recognition of the discriminator base in bacteria.     

高分辨MSCT薄层重组在常规胸部体检中的应用

目的：探讨多排螺旋CT（MSCT）高分辨薄层重组对体检中肺部疾病的诊断价值,以及MSCT薄层重组与常规CT扫描图像质量及诊断准确率对照。方法：搜集做64排常规CT扫描同时行薄层重组的2473例体检病例中筛选的97例患者进行回顾性分析。结果：97例患者在常规CT扫描中有80例可以显示病变,而在MSCT薄层重组中97例均有阳性发现;其中双肺弥漫性病变79例（两肺间质纤维化78例,肺内多发转移瘤1例）,肺结核3例,肺内孤立结节12例,早期中央型肺癌1例,先天性支气管闭锁1例以及纵隔肿瘤1例;MSCT薄层重组图像可清晰显示肺内小叶间隔线增厚、弥漫分布的囊性病变、肺内结节的细微征象。结论：MSCT薄层重组在胸部体检中的诊断阳性率、细节分辨率、图像质量及确诊率均优于常规CT,可作为肺内病变尤其是早期肺癌筛查方法之首选。