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Molecular rotor based on an oxidized resorcinarene

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Organic Chemistry Frontiers 2022年第1期9卷 39-50页

作者： daniel t.payne Jan Labuta Zdeněk Futera Václav Březina Lenka Hanyková Mandeep K.Chahal Jonathan P.Hill International Center for Materials Nanoarchitectonics National Institute for Materials ScienceNamiki 1-1TsukubaIbaraki 305-0044Japan bInternational Center for Young Scientists National Institute for Materials ScienceNamiki 1-1TsukubaIbaraki 305-0044Japan Institute of Physics Faculty of ScienceUniversity of South BohemiaBranišovská1760ČeskéBudějovice 37005Czech Republic Faculty of Mathematics and Physics Charles UniversityV Holešovičkách 218000 Prague 8Czech Republic

Molecular rotors are an important class of dynamic molecules which have been studied not only for their possible uses as components of molecular machines but also because of potential applications as probes of local viscosity in biological media,especially self-assembled *** the former,factors affecting rotational motility are critical while for the latter the rotor activity must be complexed with an output signal(often fluorescence)for reporting of local *** single stator-double rotor activity of an oxidized resorcinarene(fuchsonarene)macrocycle containing unsaturated hemiquinonoid groups at its meso positions was *** contain two hemiquinonoid substituents at diagonally-opposed meso-positions with two electron rich phenol groups at the remaining meso-positions between the hemiquinonoid *** meso-substituents are in proximity at one side of the resorcinarene macrocycle(so-called rccc-type isomer)with rotational activity of the phenol *** rates of the phenol moieties can be controlled by varying temperature,solvent polarity and acidity of the medium of study with rotation being thermally activated in neutral and acidic media and tunable in the range from 2 s^(−1) to 20000 s^(−1).Experimental and computational data indicate that rotation of the mobile phenol meso-substituents is remotely affected by interactions with acidic solvents at the carbonyl CvO groups of macrocyclic acetyloxy groups,which occurs with the emergence of a lower energy electronic absorption band whose intensity is correlated with both the acidity of the medium and the rotation rate of the phenol ***-dependent DFt calculations suggest that the low energy band is due to a molecular conformational adjustment affecting electronic conjugation caused by strong interaction of macrocyclic acetyloxy carbonyl groups with the acid *** work presents a molecular mechanical model for estimating solution acidity a

关键词： substituent rotation oxidized

Randomized controlled trials - mechanistic studies of testosterone and the cardiovascular system

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Asian Journal of Andrology 2018年第2期20卷 120-130页

作者： t Hugh Jones daniel M Kelly Robert Hague Centre for Diabetes and Endocrinology Barnsley Hospital NHS Foundation Trust Barnsley UK Academic Unit of Diabetes Endocrinology and Metabolism Department of Oncology and Metabolism University of Sheffield Medical School Sheffield UK Biomedical Research Centre Sheffield Hallam University Sheffield UK

testosterone deficiency is common in men with cardiovascular disease （CVD）, and randomized placebo-controlled trials （RCts） have reported beneficial effects of testosterone therapy on exercise-induced cardiac ischemia in chronic stable angina, functional exercise capacity, maximum oxygen consumption during exercise （VO2m,x） and muscle strength in chronic heart failure （CHF）, shortening of the Q-t interval, and improvement of some cardiovascular risk factors. testosterone deficiency is associated with an adverse CV risk profile and mortality. Clinical and scientific studies have provided mechanistic evidence to support and explain the findings of the RCts. testosterone is a rapid-onset arterial vasodilator within the coronary circulation and other vascular beds including the pulmonary vasculature and can reduce the overall peripheral systemic vascular resistance. Evidence has demonstrated that testosterone mediates this effect on vascular reactivity through calcium channel blockade （L-calcium channel） and stimulates potassium channel opening by direct nongenomic mechanisms. testosterone also stimulates repolarization of cardiac myocytes by stimulating the ultra-rapid potassium channel-operated current. testosterone improves cardiac output, functional exercise capacity, VO2m=x and vagally mediated arterial baroreceptor cardiac reflex sensitivity in CHF, and other mechanisms. Independent of the benefit of testosterone on cardiac function, testosterone substitution may also increase skeletal muscle glucose metabolism and enhance muscular strength, both factors that could contribute to the improvement in functional exercise capacity may include improved glucose metabolism and muscle strength. testosterone improves metabolic CV risk factors including body composition, insulin resistance, and hypercholesterolemia by improving both glucose utilization and lipid metabolism by a combination of genomic and nongenomic actions of glucose uptake and utilization expression of the

关键词： cardiovascular testosterone testosterone replacement

Humans influence shrimp movement: a conservation behavior case study with "Shrimp Watching" ecotourism

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Current Zoology 2022年第2期68卷 169-176页

作者： Watcharapong HONGJAMRASSILP daniel t.BLUMStEIN Department of Ecology and Evolutionary Biology University of California Los AngelesLos AngelesCA 90095-1606USA

An increase in ecotourism adversely impacts many animals and contributes to biodiversity *** mitigate these impacts,we illustrate the application of a conservation behavior framework toward the development of a sustainable ecotourism management *** Ubon Ratchathani,thailand,thousands of tourists annually come to see a unique mass migration of shrimps on land(referred to as"shrimp parading").Preliminary work suggests that this tourism has negatively impacted the *** reduce tourism-related impacts we studied:1)the decisions shrimps make when parading and 2)how shrimps respond to different light intensities and *** created an artificial stream and tested the conditions that influence parading by experimentally varying the presence of light and systematically manipulating water velocity(10,60,and 100cm/s).Additionally,we conducted an in situ experiment to study how shrimps respond to tourists'lights under three intensities(50,400,and 9,000 lux)and five colors(white,blue,green,orange,and red).We found most shrimps prefer to leave the river when it is dark and there is low water *** responded the least to red (λmax=630 nm>and orange(λmax=625 nm)light at 50 *** findings were used to develop a management plan by creating three different tourist zones,which maximize tourist needs and minimize the anthropogenic impacts on the *** work could be used as an example of the application of conservation behavior framework in developing management plan for sustainable ecotourism for other invertebrate taxa.

关键词： anthropogenic light caridean shrimps collective behavior freshwater prawn migration nature-based tourism

Anti-predator behavior along elevational and latitudinal gradients in dark-eyed juncos

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Current Zoology 2020年第3期66卷 239-245页

作者： Madelin ANDRADE daniel t.BLUMStEIN Department of Ecology and Evolutionary Biology University of California621 Young Drive SouthLos AngelesCA 90095-1606USA

Flight-initiation distance(FID),the distance between an individual and experimenter when it begins to flee,can be used to quantify *** other factors,prior studies have shown that latitude explains significant variation in avian FID:at lower latitudes,individuals and species have longer FIDs than those living at higher *** prior studies have focused on the effect of elevation on *** the similar patterns of seasonality,climate,and potentially predator density,that covary between latitude and elevation,birds at higher elevations might tolerate closer *** asked whether elevation or latitude would explain more variation in the FID of a common passerine bird species,dark-eyed juncos(Junco hyemalis).Juncos live in a variety of habitats along both latitudinal and elevational *** found that statistical models containing elevation as a variable explained more of the variation in FID than did models containing *** also found,unexpectedly,that birds at higher elevation fled at greater *** more predators were sighted per hour at higher elevations than at lower elevations,the frequency of predator sightings did not explain a significant amount of variation in *** result questions whether predator density is the main driver of risk perception along elevational ***,because elevation explains more variation in FID than latitude in at least one species,these findings have direct implications on how human impacts on birds are ***,those designing set-back zones to reduce human impact on birds may consider modifying them based on both latitude and elevation.

关键词： antipredator behavior FID latitude elevation dark-eyed junco Junco hyemalis

Experimental studies on the erosion rate of different heat treated carbon steel economiser tubes of power boilers by fly ash particles

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International Journal of Minerals,Metallurgy and Materials 2009年第5期16卷 534-539页

作者： t.A.daniel Sagayaraj S.Suresh M.Chandrasekar Department of Mechanical Engineering National Institute of Technology Tiruchirappalli-620015Tamil NaduIndia

the experimental investigations on the effect of the fly ash particle size, velocity, impingement angle, and feed rate were done with an emphasis on the effect of erosion on annealed SA 210 GrA1 （A） and normalized SA 210 GrA1 （N） carbon steel economizer-tube materials. Erosion rates were evaluated with different impingement angles ranging from 15° to 90°, at four different velocities of 32.5, 35, 37.5, and 40 m/s, and at four different feed rates of fly ash particles of 2, 4, 6 and 8 g/min. the erodent used was fly ash particles, sizes ranging from 50-250 μm of irregular shapes. Erosion rate is found to be the maximum at the impingement angle of 30°. Erosion rates of the carbon steel tube in different heat treatment conditions, annealed and normalized, at a constant velocity of 32.5 m/s with different angles were studied. In all cases of feed rates, impingement angles, particle sizes, and velocities of fly ash particles, it has been found that the erosion rate of the annealed tube is less than that of the normalized tube. Empirical correlations for erosion rate relating the velocity, size, feed rate, and impingement angle of the particles and elongation property of the target materials were arrived. Morphologies of the eroded surface were examined by scanning electron microscope （SEM）.

关键词： erosion rate economiser tubes annealing normalizing

Response of endemic afroalpine rodents to the removal of livestock grazing pressure

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Current Zoology 2011年第6期57卷 741-750页

作者： Flavie VIAL David W. MACDONALD daniel t. HAYDON Boyd Orr Centre for Population and Ecosystem Health Institute of Biodiversity Animal Health and Comparative Medicine College of Medical Veterinary and Life Sciences University of Glasgow Glasgow G12 8QQ UK. Wildlife Conservation Research Unit Zoology Department University of Oxford The Recanati-Kaplan Centre Tubney House Tubney OX13 5QL UK.

the Bale Mountains of Ethiopia represent the world＇s largest continuous extent of afroalpine habitat. With a peak combined density of over 8000 individuals/km2, the endemic giant mole rat tachyoryctes macrocephalus, Blick＇s grass rat Arvi- canthis blicki and the brush-furred mouse Lophuromys melanonyx are the dominant wild herbivores within this ecosystem and may be affected by the presence of high densities of domestic livestock. the purpose of this study was to establish whether these endemic rodent populations could respond to the removal of grazing pressure inside three 0.25 hectare livestock exclosures （paired with grazed control plots） and to determine whether such response was mediated through concomitant changes in the vegetation structure. We hypothesised that livestock grazing negatively affects endemic rodent populations through competition or increased predation risk and we predicted an increase in rodent biomass following the removal of grazing pressure. We found no evidence of rodent populations responding to the removal of livestock after fourteen months. the short-term nature of the ex- perimental design, environmental fluctuations and the ecosystem＇s inherent stochasticity may explain the apparent lack of a sig- nificant response. However, while this study is inconclusive, it emphasises the need for more long-term experimental investiga- tions to assess the effects of domestic grazers on vegetation and on dependent communities. the effects of rapidly increasing livestock numbers in the Bale Mountains will require continued close monitoring of vegetation and endemic animal communities as the afroalpine is altered by external biotic and abiotic forces .

关键词： Afroalpine Bale Mountains Exclosures Livestock grazing Murid rodents

Introduction to the special column： communication, cooperation, and cognition in predators

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Current Zoology 2017年第3期63卷 295-299页

作者： Arik KERSHENBAUM daniel t. BLUMStEN Department of Zoology University of Cambridge Cambridge CB23EJ UK Evolutionary Biology University of California Los Angeles CA 90095-1606 USADepartment of Ecology and

Communication is the glue that holds societies together and we might expect that highly social species with more to communicate about will have more complex communication systems and more complex cognitive abilities. Social species gain benefits from living in groups, and many of these benefits rely on intra-group communi- cation. For example, predator-specific alarm calls can lead to differ- ent evasion responses （Suzuki 2014）, or difficult to obtain food resources can be acquired using aggregation calls （King and Janik 2015）.

关键词：捕食者交流合作社会性认知能力通讯系统群体生活回避反应

Marmots do not consistently use their left eye to respond to an approaching threat but those that did fled sooner

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Current Zoology 2018年第6期64卷 727-731页

作者： daniel t.BLUMStEIN Alexis DIAZ Lijie YIN Department of Ecology and Evolutionary Biology University of California621Young Drive SouthLos AngelesCA 90095-1606USA Rocky Mountain Biological Laboratory Crested ButteCO 81224USA School of Life Sciences Peking UniversityBeijing 100871China

In many vertebrates,the brain's right hemisphere which is connected to the left visual field specializes in the processing of information about threats while the left hemisphere which is connected to the right visual field specializes in the processing of information about *** is referred to as hemispheric *** individuals that are too predictable in their response to predators could have reduced survival and we may expect selection for somewhat unpredictable *** studied hemispheric lateralization in yellow-bellied marmots Marmota flaviventer,a social rodent that falls prey to a variety of terrestrial and aerial *** first asked if they have lateralized responses to a predatory *** then asked if the eye that they used to assess risk influenced their perceptions of *** recorded the direction marmots were initially looking and then walked toward them until they *** recorded the distance that they responded to our experimental approach by looking,the eye with which they looked at us,and the distance at which they fled (i.e.,flight initiation distance;FID).We found that marmots had no eye preference with which they looked at an approaching ***,the population was not comprised of individuals that responded in consistent ***,we found that marmots that looked at the approaching person with their left eye had larger FIDs suggesting that risk assessment was influenced by the eye used to monitor the *** findings are consistent with selection to make prey less predictable for their predators,despite underlying lateralization.

关键词： antipredator behavior behavioral lateralization flight initiation distance yellow-bellied marmots

Ontogenetic shifts in perceptions of safety along structural complexity gradients in a territorial damselfish

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Current Zoology 2019年第2期65卷 183-188页

作者： Yinny CHAN Sara LO Alyssa QUAN daniel t. BLUMStEIN Department of Ecology and Evolutionary Biology University of California Los Angeles CA USA

Age and body size can influence predation risk and hence habitat use. Many species undergo ontogenetic shifts in habitat use as individuals grow larger and have different age-specific predation pressures. On coral reefs, a number of fish species are more tolerant of threats in structurally complex habitats that contain more refuges than in less structurally complex habitats. However, we do not know how risk perception varies with age, and whether age interacts with habitat complexity. Adults and juveniles, because of their size, may face different risks in structurally simple versus complex habitats. We used flight initiation distanee as a metric to analyze perceptions of risk in a species of damselfish Stegastes nigricans. All else being equal, fish fleeing at greater distances are inferred to perceive higher risk. We targeted juvenile and adult damselfish to assess whether there are ontogenetic shifts in perceptions of safety in relation to structural complexity, inferred based on percent coral cover and rugosity. We found that adult damselfish tolerated closer approach in more complex habitats as measured by percent coral cover, but not rugosity, whereas juvenile fish always allowed closer approach than adult fish regardless of complexity. this ontogenetic shift in habitat use may result from juvenile fish taking bigger risks to maximize growth, whereas older animals, who are closer to their maximum body size, can afford to take fewer risks and protect their assets.

关键词： Stegastes nigricans habitat complexity risk assessment ontogenetic shifts antipredator behavior flight initiation distanee