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Accommodating the bacterial decoding release factor as an alien protein among the RNAs at the active site of the ribosome

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Cell Research 2007年第7期17卷 591-607页

作者： Elizabeth S Poole David J Young Marjan E Askarian-Amiri Debbie-Jane G scarlett Warren P Tate Department of Biochemistry University of OtagoP.O.Box 56 DunedinNew Zealand

The decoding release factor (RF) triggers termination of protein synthesis by functionally mimicking a tRNA to spanthe decoding centre and the peptidyl transferase centre (PTC) of the ribosome. Structurally, it must fit into a site craftedfor a tRNA and surrounded by five other RNAs, namely the adjacent peptidyl tRNA carrying the completed polypeptide,the mRNA and the three rRNAs. This is achieved by extending a structural domain from the body of the protein thatresults in a critical conformational change allowing it to contact the PTC. A structural model of the bacterial terminationcomplex with the accommodated RF shows that it makes close contact with the first, second and third bases of the stopcodon in the mRNA with two separate loops of structure: the anticodon loop and the loop at the tip of helix α5. Theanticodon loop also makes contact with the base following the stop codon that is known to strongly influence termina-tion efficiency. It confirms the close contact of domain 3 of the protein with the key RNA structures of the PTC. ThemRNA signal for termination includes sequences upstream as well as downstream of the stop codon, and this may reflectstructural restrictions for specific combinations of tRNA and RF to be bound onto the ribosome together. An unbiasedSELEX approach has been investigated as a tool to identify potential rRNA-binding contacts of the bacterial RF in itsdifferent binding conformations within the active centre of the ribosome.

关键词： release factor protein synthesis termination tRNA functional mimicry molecular mimicry SELEX ribosome

Signal or cue: the role of structural colors in flower pollination

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Current Zoology 2019年第4期65卷 467-481页

作者： Jair E. Garcia Mani Shrestha scarlett R. Howard Phred Petersen Adrian G. Dyer School of Media and Communication RMIT University Melbourne Victoria 3001 Australia Faculty of Information Technology Monash University Clayton Victoria 3800 Australia

Angle dependent colors, such as iridescenee, are produced by structures present on flower petals changing their visual appearanee. These colors have been proposed to act as signals for plantinsect communication. However, there is a paucity of behavioral data to allow for interpretations of how to classify these colors either as a signal or a cue when con sidering the n atural con ditions under which pollination occurs. We sampled flowers from 6 plant species across various viewpoints looking for changes in the visual appearanee of the petals. Spectral characteristics were measured with different instruments to simulate both the spectral and spatial characteristics of honeybee's vision. We show the presenee of color patches produced by angle dependent effects on the petals and the calyx of various species;however, the appearance of the angle dependent color patches significantly varies with viewpoint and would only be resolved by the insect eye at close distances. Behavior experiments with honeybees revealed that pollinators did not use angle dependent colors to drive behavior when presented with novel flower presentations. Results show that angle dependent colors do not comply with the requirements of a signal for plant-pollinator communication since the information transmitted by these colors would be unreliable for potential, free-flying pollination vectors. We thus classify angle dependent colors produced by micro- and ultra-structures as being a cue (a feature which has not evolved for communication), and observe no evidence supporting claims of these angle dependent colors having evolved as visual signal.

关键词： approach angle color flower iridescence photography pollination vision

Physical, Chemical and Biochemical Changes of Sweetsop （Annona squamosa L.） and Golden Apple （Spondias citherea Sonner） Fruits during Ripening

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Journal of Agricultural Science and Technology(B) 2012年第11期2卷 1148-1157页

作者： Angel Guadarrama scarlett Andrade Department of Agricultural Botany College of Agriculture Central University of Venezuela Maraeay Aragua 2021 Venezuela

This study aimed at the physical, chemical and biochemical changes during ripening of Sweetsop （Annona squamosa L.） and Golden Apple （Spondias citherea Sonner） fruits during ripening as important features to better understand their postharvest handling. It was carried out physical analysis such as firmness and chemical analysis such as total chlorophyll, total carotenoids, soluble solids, pectins and titrable acidity and biochemical analysis such as pectin methyl esterase, polygalacturonase, cellulase, and peroxidase and polyphenoloxidase activities in crude extract. Fruits were harvested at different stages of ripening. Experimental design was completely randomized and was carried out analysis of variance and Tukey tests, Total chlorophyll was decreasing in later stages of ripening, total soluble solid contents increased as the fruits ripen, while the acidity expressed percentage of citric acid decreased during fruits ripening. The loss of firmness and soluble solids content increased as the fruit get ripped stage, while the content of pectin decreased. Activity was observed for pectin methyl esterase and polygalacturonase enzymes during all stages of maturation, presenting the highest activity for both enzymes in the mature state. No cellulase activity detected at any stage during the ripening of these fruits. Activity of the enzyme polyphenoloxidase and peroxidase, associated with pulp browning was higher in the last stages of ripening of these fruits. Physical, chemical and biochemical patterns during ripening were different according to fruit species suggesting differential postharvest handling requirements.

关键词： Firmness pectin pectin methyl esterase polygalacturonase peroxidase.

Honeybees prefer novel insect-pollinated flower shapes over bird-pollinated flower shapes

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Current Zoology 2019年第4期65卷 457-465页

作者： scarlett R. Howard Mani Shrestha Juergen Schramme Jair E. Garcia Aurore AvARGUES-WEBER Andrew D. Greentree Adrian G. DYER Bio-inspired Digital Sensing (BIDS) Lab School of Media and Communication RMIT University Melbourne Victoria 3000 Australia Faculty of Information Technology Monash University Melbourne Victoria 3800 Australia institute of Developmental Biology and Neurobiology (iDn) Johannes Gutenberg University Mainz 55122 Germany Centre de Recherches sur la Cognition Animale Centre de Biologie Integrative (CBI) Universite de Toulouse CNRS UPS Toulouse 31400 France ARC Centre of Excellence for Nanoscale BioPhotonics School of Science RMIT University Melbourne Victoria 3000 Australia Department of Physiology Monash University Clayton Victoria 3800 Australia

Plant-pollinator in teractio ns have a fundame ntal in fluence on flower evolution. Flower color signals are frequently tuned to the visual capabilities of important pollinators such as either bees or birds, but far less is known about whether flower shape in fluences the choices of pollinators. We tested European honeybee Apis mellifera pref ere nces using novel achromatic (gray-scale) images of 12 insect-pollinated and 12 bird-pollinated native Australian flowers in Germany;thus, avoiding in flue nces of color, odor, or prior experie nee. In depende nt bees were tested with a number of parameterized images specifically desig ned to assess pref ere nces for size, shape, brightness, or the number of flower-like shapes prese nt in an image. We show that honeybees have a pref ere nee for visiti ng images of in sect-polli nated flowers and such a pref ere nee is most-likely mediated by holistic in formati on rather than by in dividual image parameters. Our results in dicate an giosperms have evolved flower shapes which in fluence the choice behavior of importa nt pollinators, and thus suggest spatial achromatic flower properties are an important part of visual signaling for plantpollinator in teractions.

关键词： angiosperm Apis mellifera (European honeybee) bird-pollinated flower insect-pollinated pollinator

Diabetes exacerbates inflammatory bowel disease in mice with dietinduced obesity

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世界胃肠病学杂志:英文版 2023年第33期29卷 4991-5004页

作者： Kendra L Francis Kimberly M Alonge Maria Cristina Pacheco Shannon J Hu Cody A Krutzsch Gregory J Morton Michael W Schwartz Jarrad M scarlett Department of Pediatric Gastroenterology and Hepatology Seattle Children’s HospitalSeattleWA 98105United States 不详 Department of Medicinal Chemistry University of WashingtonSeattleWA 98195United States Department of Laboratory Medicine and Pathology Seattle Children's HospitalSeattleWA 98105United States

BACKGROUND The increased prevalence of inflammatory bowel disease(IBD)among patients with obesity and type 2 diabetes suggests a causal link between these diseases,potentially involving the effect of hyperglycemia to disrupt intestinal barrier *** To investigate whether the deleterious impact of diabetes on the intestinal barrier is associated with increased IBD severity in a murine model of colitis in mice with and without diet-induced *** Mice were fed chow or a high-fat diet and subsequently received streptozotocin to induce diabetic-range *** weeks later,dextran sodium sulfate was given to induce *** select experiments,a subset of diabetic mice was treated with the antidiabetic drug dapagliflozin prior to colitis *** included both clinical and histological measures of colitis activity as well as histochemical markers of colonic epithelial barrier *** In mice given a high-fat diet,but not chow-fed animals,diabetes was associated with significantly increased clinical colitis activity and histopathologic markers of disease *** was also associated with a decrease in key components that regulate colonic epithelial barrier integrity(colonic mucin layer content and epithelial tight junction proteins)in diet-induced obese *** of these effects of diabetes in diet-induced obese mice was ameliorated by restoring *** In obese mice,diabetes worsened clinical and pathologic outcomes of colitis via mechanisms that are reversible with treatment of ***-induced intestinal barrier dysfunction offers a plausible mechanism linking diabetes to increased colitis *** findings suggest that effective diabetes management may decrease the clinical severity of IBD.

关键词： Inflammatory bowel disease Type 2 diabetes Obesity Intestinal barrier Hyperglycemia Colitis in mice Tight junction proteins

Suburban travel mode choice considering transit accessibility of stops in public transport

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Journal of Southeast University(English Edition) 2021年第2期37卷 222-226页

作者： Gao Yueer Cui jie Cheng Jing Ding Ming Wang scarlett Sijia School of Architecture Huaqiao University Xiamen 361021 China Shanghai Tongji Urban Planning and Design Institute Co. Ltd. Shanghai 200092 China School of Statistics Huaqiao University Xiamen 361021 China Traffic Research Center Huaqiao University Xiamen 361021 China Wagner School New York University New York 10012-9604 USA

To analyze the influence of the transit accessibility of stops on the travel mode choices of suburban residents,the number of the lines passing by the stops within an accessible range of the resident origin and destination(OD)points and the average waiting time are used as the indexes of the transit accessibility of *** to the correlation between travel time and accessible range,the transit accessibility of stops is contrasted as piecewise variables constrained by travel *** the Jimei District of Xiamen,China,as an example,a binary logistic regression model of the suburban travel mode choice is *** results show that it is necessary to construct transit accessibility of stops as piecewise *** a higher transit accessibility of stops,more residents will choose public *** choice of the travel mode is correlated with family attributes and personal *** and evening peak hours and travel distance have little effect on the choice of travel *** with the travel in urban areas,residents often chose public transport for travel within the *** research provides a basis for encouraging public transportation priority policies and decision making for transport planners in the suburbs.

关键词： transit accessibility of stops piecewise variable travel time mode choice suburbs

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scarlett,Run!Run!Run!

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新民周刊 2014年第19期 14-14页

作者： scarlett

话说那年我大学二年级,寒假时在电影剧组实习。初次在电影剧组工作的,战战兢兢的,却还是发生了一件小错但大窘的事。作为Office PA,每天将通告从门下塞入房间给全剧组工作人员是必须的工作。有天一位演员高先生刚刚从美国飞来进组,

关键词： scarlett,Run!Run!Run

Hepatitis B virus outreach to immigrant population in Greater Boston Area: Key to improving hepatitis B knowledge

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World Journal of Gastroenterology 2017年第42期23卷 7626-7634页

作者： Raissa Djoufack scarlett Se Yun Cheon Aisha Mohamed Fatou Faye Korka Diouf Richard Colvin James Morrill Ann-Marie Duffy-Keane Ponni Perumalswami Gonzague Jourdain Dahlene Fusco Universite des Montagnes Wellesley College Cooper Medical School of Rowan University Suffolk University Division of General Internal Medicine MGH MGH Community Health Associates Icahn School of Medicine at Mount Sinai Institut de Recherche pour le Dé-veloppement Chiang Mai University Harvard T.H. Chan School of Public Health Division of Infectious Disease Department of Medicine Vaccine and Immunotherapy Center Laboratory of Systems Pharmacology Harvard Medical School

AIM To characterize the understanding of hepatitis B virus(HBV) and determine if outreach improves HBV understanding among Greater Boston Area immigrants. METHODS Six outreach sessions were held in various community venues in the Greater Boston Area. Verbal consent was obtained from participants prior to starting each session. Each session included a pre-session questionnaire, followed by a teaching session, and then a post-session questionnaire. In person interpreters were present for translation during the teaching session and assistance for questionnaire completion when needed. The questions were developed based on the HBV clinical experience of physicians who serve largely immigrant populations. Questionnaires included Likerttype scale, open-ended, and true-false questions. All results were anonymous. RESULTS One hundred and one people participated in this study. Participants were 30% male with ages ranging from 19 to 87 years. The study population included immigrants from 21 countries, as well as seven United States-born participants. The greatest numbers of participants were from Somalia(44%), Morocco(10%), and Cameroon(8%). Pre session questionnaires revealed that 42% of participants were unaware that HBV can cause cancer, and 50% were unaware that therapies for HBV exist. Our brief teaching intervention led to improved scores on post session questionnaires. For example, at baseline, 58% of participants responded correctly to the question "HBV infection can cause scarring of the liver and liver cancer", whereas 79% of participants responded correctly after the teaching session(P = 0.01). Furthermore, the mean of total correct answers in the true or false portion of the questionnaire increased from 5.5 to 7.6(P < 0.001).CONCLUSION A teaching session targeting Boston Immigrants atrisk for HBV helped improve scores on HBV knowledge questionnaires. Outreach may empower at-risk patients to pro-actively seek HBV care.

关键词： Hepatitis B virus Outreach Linkage to care Immigrant Boston

scarlett McNally:运动是一剂灵丹妙药

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英国医学杂志中文版 2020年第5期23卷 253-254页

作者： scarlett McNally Deng Xuan(译) 莫云凌(审校) Eastbourne District General Hospital The university of Bristol 航空医学研究所附属医院

可预防的不良健康问题(ill-health)造成人力、劳动力和财务成本对英国经济来说就像定时炸弹。虽然预期寿命的延长是个好消息,但预测显示,未来平均每名成年人将需要10年的社会照护(social care)。因为20世纪80年代的房地产暴利掩盖了当... 详细信息

可预防的不良健康问题(ill-health)造成人力、劳动力和财务成本对英国经济来说就像定时炸弹。虽然预期寿命的延长是个好消息,但预测显示,未来平均每名成年人将需要10年的社会照护(social care)。因为20世纪80年代的房地产暴利掩盖了当今的社会照护成本,决策者可能无法掌握这一挑战的真正规模。我们的后代——以及未来的政府——不会再有这种缓冲。

关键词：财务成本预期寿命照护成年人