On the Application of Fuzzy Decision Theory in Chemotherapy

1IntreductionTheliteratUreonmulti-Criteriondecisionmaking(MCDM)problemshas~tremendouslyintherecentpast.TwomajorareashaveevolvedwhiChbothconcentrateondecisionmakingwithseveralcriteria:multiobjectivedecisionmaking(MODM)andmulti-attributedecisionmaking(MADM).TheformerconcentratesoncontinuousdecisionspaceandthelatterfocusesonproblemswithdiscreteSPace.FuzzysettheoryhascontributedtoMODMproblemsaswellastheMADMProblems.ThegeneralMODMproblemcanbedeft.edLllasfollows:Twostagescangenerallybe…     

Multiscale simulations of protein folding: application to formation of secondary structures

A multiscale simulation method of protein folding is proposed, using atomic representation of protein and solvent, combing genetic algorithms to determine the key protein structures from a global view, with molecular dynamic simulations to reveal the local folding pathways, thus providing an integrated landscape of protein folding. The method is found to be superior to previously investigated global search algorithms or dynamic simulations alone. For secondary structure formation of a selected peptide, RN24, the structures and dynamics produced by this method agree well with corresponding experimental results. Three most populated conformations are observed, including hairpin, β-sheet and α-helix. The energetic barriers separating these three structures are comparable to the kinetic energy of the atoms of the peptide, implying that the transition between these states can be easily triggered by kinetic perturbations, mainly through electrostatic interactions between charged atoms. Transitions between α-helix and β-sheet should jump over at least two energy barriers and may stay in the energetic trap of hairpin. It is proposed that the structure of proteins should be jointly governed by thermodynamic and dynamic factors; free energy is not the exclusive dominant for stability of proteins.     

Ecological,behavioral, and phylogenetic influences on the evolution of dorsal color pattern in geckos*

The dorsal surfaces of many taxonomic groups often feature repetitive pattern elements consisting of stripes, spots, or bands. Here, we investigate how distinct categories of camouflage pattern work by relating them to ecological and behavioral traits in 439 species of gecko. We use phylogenetic comparative methods to test outstanding hypotheses based on camouflage theory and research in other taxa. We found that bands are associated with nocturnal activity, suggesting bands provide effective camouflage for motionless geckos resting in refugia during the day. A predicted association between stripes and diurnal activity was not supported, suggesting that stripes do not work via dazzle camouflage mechanisms in geckos. This, along with a lack of support for our prediction that plain patterning should be associated with open habitats, suggests that similar camouflage patterns do not work in consistent ways across taxa. We also found that plain and striped lineages frequently switched between using open or closed habitats, whereas spotted lineages rarely transitioned. This suggests that pattern categories differ in how specialized or generalized their camouflage is. This result has ramifications for theory on how camouflage compromises to background heterogeneity and how camouflage pattern might influence evolutionary trajectories.     

Interactions among leaf toughness, chemistry, and harvesting by attine ants

Abstract. 1. Young and mature leaves of a tropical legume, Inga edulis var. minutula Schery, are strikingly different in secondary chemistry, especially condensed tannins, and leaf toughness.
2. Bioassays with the two different leaf types indicate that leaf cutter ants, Atta cephalotes (L.), always find mature leaves relatively more acceptable than young leaves when selection was based on chemical cues.
3. Since extracts of young leaves show greziter inhibition of fungal pectinases we suggest that leaf-cutter ants are capable of distinguishing which leaf types are most suitable for the growth of their symbiotic fungus.
4. However, mature leaves are 3 times tougher than young leaves and this prevents leaf-cutter ants from harvesting the more suitable mature leaves.
5. Consequently, bioassays which require cutting before leaf removal indicate that some colonies actually harvest more from the less suitable young leaves.
6. We suggest that the quality of a colony's habitat may indicate whether a colony will harvest more of the less suitable young leaves. Colonies which are harvesting from highly suitable host plants avoid the tropical legume I.edulis while those in poorer habitats accept I.edulis but, because of leaf toughness, mostly harvest the less suitable young leaves.     

Coordination and consensus:the role of compromisers in Tibetan macaques

Coordination and consensus in collective behavior have attracted a lot of research interest. Although previous studies have investigated the role of compromisers in group consensus, they provide little insight into why compromisers would allow such social arrangements to persist. In this study, the potential relationship between group movements and conflict management in Tibetan macaques in Anhui province, China, was investigated using hierarchical cluster analyses. Some members with higher social centrality or social rank often formed a front-runner cluster during group movements. They had higher leadership success than individuals outside the front-runner cluster. Other members with lower social centrality or social rank often followed the group movements initiated by the front-runner cluster, and thus formed the compromiser cluster. Compromisers’ proximity relations with front-runners increased with their following scores to front-runners. Compromisers had fewer events of being attacked when they followed group movements initiated by the front-runners. The compromising process made compromisers lose the choice of direction preference, but it could increase their individual safeties. This trade-off suggests that compromisers play a role of decision-maker in coordination and consensus scenarios among social animals.     

Compromise in competition between free energy and binding effect of intrinsically disordered protein p53 C-terminal domain

The C-terminal domain (CTD) of tumour suppressor p53 is an intrinsically disordered protein which has been shown to be able to bind multiple partner proteins and exercise diverse physiological functions in the cell. In this study, we performed molecular dynamics simulations on the isolated p53 CTD, as well as three regulatory binding complexes to investigate the conformational ensemble of isolated p53 CTD and its dynamic structures when different binding partner present. The results demonstrate that the isolated p53 CTD resembles a molten globule rather than extended structure. It mainly adopts random coil conformations with some tendency to form helical structures, which is consistent with experimental observations. For isolated p53 CTD, the dynamics is exclusively dominated by the intrinsic free energy and the p53 CTD could not folded spontaneously to each binding competent state which is located in high free energy region. However, when the binding partners present, the dynamics of p53 CTD are dominated by two mechanisms, the p53 CTD tending to adopt the structure with minimum free energy as isolate existed and the binding energy from partner protein tending to minimum. Each of them has an extreme tendency and corresponds to a possible characteristic state, the random coil state and each binding competent state. The compromise in competition between these two mechanisms results in alternate realisation of different characteristic states, while the relative strength of each mechanism determines the sampling frequency of each characteristic state.     

游离皮瓣移植术后血运监测的研究进展

游离皮瓣移植已经成为修复重建外科常用的修复手段之一,其成功率已经超过95%,但微循环障碍的风险仍然存在,临床上皮瓣救助率与缺血时间呈负相关,因此游离皮瓣移植术后的血运监测至关重要。作者以"皮瓣"和"监测"为检索词在PubMed数据库检索出2000年1月到2014年1月期间关于游离皮瓣移植术后监测的相关文献,纳入标准为至少5篇以上的相关报道,通过分析相关文献概述当前主要的监测方法,从临床实用性、可靠性等方面分析其优缺点。     

Mice transgenic for the Huntington's disease mutation are resistant to chronic 3-nitropropionic acid-induced striatal toxicity

Neuronal loss in Huntington's disease (HD) is seen first in the neostriatum. It has been suggested that impaired metabolism underlies this degeneration, as striatal vulnerability to excitotoxicity is increased by metabolic compromise. At 12 weeks of age, a transgenic mouse carrying the HD mutation (R6/2 line) has been shown to have an increased vulnerability to the mitochondrial toxin 3-nitropropionic acid (3-NP). However, in contrast, younger R6/2 mice appear to be less vulnerable than wild-type (WT) mice to the excitotoxins kainic acid and quinolinic acid (QA). In this study, we examine the possibility that the sensitivity of R6/2 mice to 3-NP might be age dependent. We treated young, symptomatic R6/2 mice with 3-NP and found that despite their progressive neurological phenotype, they were not more susceptible to 3-NP intoxication than their WT littermates. Further, fewer R6/2 than WT mice developed striatal lesions. We suggest that compensatory mechanisms exist in the R6/2 mouse brain that protect it against the toxic effect of the transgene and coincidentally protect against exogenous toxins such as 3-NP, QA, and kainic acid. The existence of similar compensatory mechanisms may explain why, in humans, HD is a late-onset disorder, despite early expression of the genetic mutation.     

Compromise strategies for action selection

Among the many properties suggested for action-selection mechanisms, a prominent one is the ability to select compromise actions, i.e. actions that are not the best to satisfy any active goal in isolation, but rather compromise between multiple goals. This paper briefly reviews the history of compromise behaviour and presents experimental analyses of it in an attempt to determine how much compromise behaviour aids an agent. It concludes that optimal compromise behaviour has a surprisingly small benefit over non-compromise behaviour in the experiments performed, and presents some reasons why this may be true and hypothesizes cases where compromise behaviour is truly useful. In particular, it hypothesizes that a crucial factor is the level at which an action is taken (low-level actions are specific, such as 'move left leg'; high-level actions are vague, such as 'forage for food'). This paper hypothesizes that compromise behaviour is more beneficial for high- than low-level actions.