18 research outputs found
Jordan's Inequality: Refinements, Generalizations, Applications and Related Problems
No full textThis is an expository article. Some developments on refinements,
generalizations, applications of Jordan’s inequality and related problems, including
some estimates for three classes of complete elliptic integrals and several
proofs of Wilker’s inequality, are summarized
An Alternate Route of Ethylene Receptor Signaling
No full textThe gaseous plant hormone ethylene is perceived by a family of ethylene receptors and mediates an array of ethylene responses. In the absence of ethylene, receptor signaling is conveyed via the C-terminal histidine kinase domain to the N-terminus of the CONSTITUTIVE TRIPLE RESPONSE1 (CTR1) protein kinase, which represses ethylene signaling mediated by ETHYLENE INSENSITIVE2 (EIN2) followed by EIN3. In the presence of ethylene, the receptors are inactivated when ethylene binds to their N-terminal domain, and consequently CTR1 is inactive, allowing EIN2 and EIN3 to activate ethylene signaling. Recent findings have shown that the ethylene receptor N-terminal portion can conditionally mediate the receptor signal output in mutants lacking CTR1, thus providing evidence of an alternative pathway from the ethylene receptors not involving CTR1. Here we highlight the evidence for receptor signaling to an alternative pathway and suggest that receptor signaling is coordinated via the N- and C-termini, as we address the biological significance of the negative regulation of ethylene signaling by the 2 pathways
Stigmatic bodies: The corporeal Qiu Miaojin
No full textB1 - Research Book ChaptersDeposited with permission of University of Hawaii PressQiu Miaojin (1969–1995) is Taiwan’s best-known lesbian author. In local lesbian (nütongzhi) subcultures, Qiu’s books are frequently cited as classics, particularly her 1994 novel The Crocodile’s Journal (Eyu shouji), the first novel in Taiwan’s modern literary history to be written by an author commonly known to be a lesbian that takes erotic relationships between women as its central theme. Qiu’s fiction is much celebrated, too, in the mainstream literary establishment; The Crocodile’s Journal won the prestigious China Times Honorary Prize for Literature for Qiu posthumously, following her suicide in mid-1995. Qiu’s unique literary style—mingling cerebral, experimental language use, psychological realism, biting social critique through allegory, and a surrealist effect deriving from the use of arrestingly unusual metaphors—is strongly influenced by both European and Japanese literary and cinematic modernisms. Although her fiction has been compared, in its principal subject-matter, to Radclyffe Hall’s 1920s classic of lesbian alienation, The Well of Loneliness, most frequently cited in Qiu’s writings are male modernist and postmodernist ‘masters’ (many of whose work shows a strongly homoerotic aesthetic) including Andre Gide, Jean Genet, Kobo Abe, Yukio Mishima, Haruki Murakami, Andrei Tarkovsky, and Derek Jarman—locally, Qiu’s work has been critiqued for this apparent masculinist bias. Qiu’s early short stories ‘Zero Degree’ (‘Linjiedian,’ 1988) and ‘Platonic Hair’ (‘Bolatu zhi fa,’ 1990), to be discussed in this chapter, appeared in her first collection, The Revelry of Ghosts (Guide kuanghuan) in 1991, following their earlier serialization in local daily newspapers. They are Qiu’s first works to treat thematically homoerotic desire between women
Frequency-dependent brain regional homogeneity alterations in patients with mild cognitive impairment during working memory state relative to resting state
No full textSeveral studies have reported working memory deficits in patients with mild cognitive impairment (MCI). However, previous studies investigating the neural mechanisms of MCI have primarily focused on brain activity alterations during working memory tasks. No study to date has compared brain network alterations in the working memory state between MCI patients and normal control subjects. Therefore, using the index of regional homogeneity (ReHo), we explored brain network impairments in MCI patients during a working memory task relative to the resting state, and identified frequency-dependent effects in separate frequency bands.Our results indicate that, in MCI patients, ReHo is altered in the posterior cingulate cortex in the slow-3 band (0.073–0.198 Hz), and in the bottom of the right occipital lobe and part of the right cerebellum, the right thalamus, a diffusing region in the bilateral prefrontal cortex, the left and right parietal-occipital regions, and the right angular gyrus in the slow-5 band (0.01–0.027 Hz). Furthermore, in normal controls, the value of ReHo in clusters belonging to the default mode network decreased, while the value of ReHo in clusters belonging to the attentional network increased during the task state. However, this pattern was reversed in MCI patients, and was associated with decreased working memory performance. In addition, we identified altered functional connectivity of the abovementioned regions with other parts of the brain in MCI patients.This is the first study to compare frequency-dependent alterations of ReHo in MCI patients between resting and working memory states. The results provide a new perspective regarding the neural mechanisms of working memory deficits in MCI patients, and extend our knowledge of altered brain patterns in resting and task-evoked states
Immediate Effects of Smoking on Cardiorespiratory Responses During Dynamic Exercise: Arm Versus Leg Ergometry
No full textPurpose: This study compared the immediate effects of smoking on cardiorespiratory responses to dynamic arm and leg exercises. Methods: This randomized crossover study recruited 14 college students. Each participant underwent 2 sets of arm-cranking (AC) and leg-cycling (LC) exercise tests. The testing sequences of the control trial (participants refrained from smoking for 8 hours before testing) and the experimental trial (participants smoked 2 cigarettes) were randomly chosen. We observed immediate changes in pulmonary function and heart rate variability after smoking and before the exercise test. The participants then underwent graded exercise tests of their arms and legs, respectively, until reaching exhaustion. We compared the peak work achieved and the time to exhaustion during the exercise tests with various cardiorespiratory indices [i.e., heart rate, oxygen consumption (VO2), minute ventilation (VE)]. The main effects of the time and the trial, as well as their interaction effects on outcome measures, were investigated using repeated measure ANOVA.Results: Five minutes after smoking, the participants exhibited reduced forced vital capacities and forced expiratory volumes in the first second (P < .05), in addition to elevated resting heart rates (P < .001). The high-frequency, low-frequency, and the total power of the heart rate variability were also reduced (P < .05) at rest. For the exercise test periods, smoking reduced the time to exhaustion (P = .005) and the ventilatory threshold (P < .05) in the LC tests, whereas there were no significant effects in the AC tests. A trend analysis revealed a significant (P < .001) trial-by-time interaction effect for heart rate, VO2, and VE during the graded exercise test. Lower VO2 and VE levels were exhibited in the exercise response of the smoking trial than in that of the control LC trials, whereas there was no discernable inter-trial difference in the AC trials. Moreover, the differences in heart rate and VE response between the LC and AC exercises were significantly smaller after the participants smoked.Conclusion: This study verified that smoking can significantly decrease performance and cardiorespiratory responses to leg exercises. However, the negative effects of smoking on arm exercise performance were not as pronounced
Role and Regulation of Autophagy in Heat Stress Responses of Tomato Plants
No full textAs sessile organisms, plants are constantly exposed to a wide spectrum of stress conditions such as high temperature, which causes protein misfolding. Misfolded proteins are highly toxic and must be efficiently removed to reduce cellular proteotoxic stress if restoration of native conformations is unsuccessful. Although selective autophagy is known to function in protein quality control by targeting degradation of misfolded and potentially toxic proteins, its role and regulation in heat stress responses have not been analyzed in crop plants. In the present study, we found that heat stress induced expression of autophagy-related (ATG) genes and accumulation of autophagosomes in tomato plants. Virus-induced gene silencing of tomato ATG5 and ATG7 genes resulted in increased sensitivity of tomato plants to heat stress based on both increased development of heat stress symptoms and compromised photosynthetic parameters of heat-stressed leaf tissues. Silencing of tomato homologs for the selective autophagy receptor NBR1, which targets ubiquitinated protein aggregates, also compromised tomato heat tolerance. To better understand the regulation of heat-induced autophagy, we found that silencing of tomato ATG5, ATG7 or NBR1 compromised heat-induced expression of not only the targeted genes but also other autophagy-related genes. Furthermore, we identified two tomato genes encoding proteins highly homologous to Arabidopsis WRKY33 transcription factor, which has been previously shown to interact physically with an autophagy protein. Silencing of tomato WRKY33 genes compromised tomato heat tolerance and reduced heat-induced ATG gene expression and autophagosome accumulation. Based on these results, we propose that heat-induced autophagy in tomato is subject to cooperative regulation by both WRKY33 and ATG proteins and plays a critical role in tomato heat tolerance, mostly likely through selective removal of heat-induced protein aggregates
A Selective Review of Multimodal Fusion Methods in Schizophrenia
No full textSchizophrenia (SZ) is one of the most cryptic and costly mental disorders in terms of human suffering and societal expenditure (van Os and Kapur, 2009). Though strong evidences for functional, structural and genetic abnormalities associated with this disease exist, there is yet no replicable finding which has proven accurate enough to be useful in clinical decision making (Fornito et al., 2009), and its diagnosis relies primarily upon symptom assessment (Williams et al., 2010a). It is likely in part that the lack of consistent neuroimaging findings is because most models favor only one data type or do not combine data from different imaging modalities effectively, thus missing potentially important differences which are only partially detected by each modality (Calhoun et al., 2006a). It is becoming increasingly clear that multi-modal fusion, a technique which takes advantage of the fact that each modality provides a limited view of the brain/gene and may uncover hidden relationships, is an important tool to help unravel the black box of schizophrenia. In this review paper, we survey a number of multimodal fusion applications which enable us to study the schizophrenia macro-connectome, including brain functional, structural and genetic aspects and may help us understand the disorder in a more comprehensive and integrated manner. We also provide a table that characterizes these applications by the methods used and compare these methods in detail, especially for multivariate models, which may serve as a valuable reference that helps readers select an appropriate method based on a given research
FMRI evidence for the interaction between orthography and phonology in reading Chinese compound words
No full textCompound words make up a major part of modern Chinese vocabulary. Behavioral studies have demonstrated that access to lexical semantics of compound words is driven by the interaction between orthographic and phonological information. However, little is known about the neural underpins of compound word processing. In this fMRI study, we asked participants to perform lexical decision to pseudohomophones, which were constructed by replacing one or both constituents of two-character compound words with orthographically dissimilar homophonic characters. Mixed pseudohomophones, which shared the first constituent with the base words, were more difficult to reject than non-pseudohomophone nonwords. This effect was accompanied by the increased activation of bilateral inferior frontal gyrus (IFG), left inferior parietal lobule (IPL), and left angular gyrus. The pure pseudohomophones, which shared no constituent with their base words, were rejected as quickly as nonword controls and did not elicit any significant neural activation. The effective connectivity of a phonological pathway from left IPL to left IFG was enhanced for the mixed pseudohomophones but not for pure pseudohomophones. These findings demonstrated that phonological activation alone, as in the case of the pure pseudohomophones, is not sufficient to drive access to lexical representations of compound words, and that orthographic information interacts with phonology, playing a gating role in the recognition of Chinese compound words
The essential component in DNA-based information storage system: robust error-tolerating module
No full textThe size of digital data is ever increasing and is expected to grow to 40,000EB by 2020, yet the estimated global information storage capacity in 2011 is less than 300EB, indicating that most of the data are transient. DNA, as a very stable nano-molecule, is an ideal massive storage device for long-term data archive. The two most notable illustrations are from Church et al. and Goldman et al., whose approaches are well-optimized for most sequencing platforms – short synthesized DNA fragments without homopolymer. Here we suggested improvements on error handling methodology that could enable the integration of DNA-based computational process, e.g. algorithms based on self-assembly of DNA. As a proof of concept, a picture of size 438 bytes was encoded to DNA with Low-Density Parity-Check error-correction code. We salvaged a significant portion of sequencing reads with mutations generated during DNA synthesis and sequencing and successfully reconstructed the entire picture. A modular-based programming framework - DNAcodec with a XML-based data format was also introduced. Our experiments demonstrated the practicability of long DNA message recovery with high error-tolerance, which opens the field to biocomputing and synthetic biology
Emerging Roles of Hydrogen Sulfide in Inflammatory and Neoplastic Colonic Diseases
No full textHydrogen sulfide (H2S) is a toxic gas that has been recognized as an important mediator of many physiological processes, such as neurodegeneration, regulation of inflammation and blood pressure, and metabolism. In the human colon, H2S is produced by both endogenous enzymes and sulfate-reducing bacteria (SRB). H2S is involved in physiological and pathophysiological conditions of the colon, such as inflammatory bowel disease and colorectal cancer, which makes the pharmacological modulation of H2S production and metabolism a potential target for the treatment of colonic diseases. However, the exact mechanisms and pathways by which H2S-mediates normal physiological function and disease in the colon are not fully understood yet. Besides, the production and release of H2S are modulated by both endogenous and exogenous factors. This review will discuss the production and storage of H2S, its biological roles and the emerging importance in physiology and pathology of inflammatory bowel disease and colorectal cancer
