43,090 research outputs found
Gardens in the Air: A Reexamination of the Ottoman Tulip Age
Scholars have long considered the “Tulip Age” to be a sort of Ottoman renaissance—a golden age initiated by the 1718 Treaty of Passarowitz and lasted until the Anti-Tulip Rebellion in 1730. However, recent scholarship has questioned the objectivity of the field’s founding historian, Ahmed Refik, who based his theory off of the twofold concepts of a marked increase in tulip culture and a movement toward westernization in the Ottoman Empire. Because of this shaky foundation, this research reexamines the debate from the beginning: the tulip’s connection to earlier Turkic arts and the actualities of Ottoman “modernization.” This perspective on the “real” Tulip Age is instrumental in suggesting a new hypothesis—that the Tulip Age did not exist in the way historians have accepted for a hundred years
Mechanical Properties Of Sediment Determine Burrowing Success And Influence Distribution Of Two Lugworm Species
We apply new perspectives on how organisms burrow by examining the association of in situ variation in sediment mechanical properties with burrowing ability and species distribution of two sympatric lugworms, Abarenicola pacifica and Abarenicola claparedi. We quantified the sediment\u27s resistance to penetration and its grain size distribution at sites inhabited by each species. Abarenicola pacifica individuals were found in significantly harder to penetrate, more heterogeneous sediments. We compared worm burrowing ability using reciprocal transplant experiments. Worms from firmer sediments, A. pacifica, were able to make successful steep burrows in sediments characteristic of either species. In contrast, A. claparedi individuals often failed to complete successful burrows in the firmer A. pacifica sediment. To examine how morphological differences could explain these patterns, we compared body wall musculature and measured how well individuals support their own bodies when draped over a cantilever. Lugworms from the firmer sediment had thicker body wall musculature and held their bodies more rigidly than did worms from softer sediments. Additionally, we observed subtle differences in the papillae on the proboscises\u27 surfaces, which could affect worm–sediment interactions, but we found no differences in the chaetae of the two species. Abarenicola claparedi produced more mucus, which could be important in shoring up burrow walls in their shifting, sandy habitat. This study presents the first example of using field-based experiments to determine how sediment mechanical properties and worm burrowing ability could act to determine organismal distribution. Our findings have broader ecological implications because of the role of lugworms as ecosystem engineers
Emergent Run-and-Tumble Behavior in a Simple Model of Chlamydomonas with Intrinsic Noise
Recent experiments on the green alga Chlamydomonas that swims using
synchronized beating of a pair of flagella have revealed that it exhibits a
run-and-tumble behavior similar to that of bacteria such as E. Coli. Using a
simple purely hydrodynamic model that incorporates a stroke cycle and an
intrinsic Gaussian white noise, we show that a stochastic run-and-tumble
behavior could emerge, due to the nonlinearity of the combined
synchronization-rotation-translation dynamics. This suggests the intriguing
possibility that the alga might exploit nonlinear mechanics---as opposed to
sophisticated biochemical circuitry as used by bacteria---to control its
behavior.Comment: 5 pages, 2 composite figures (made of 12 separate EPS files
Lamb wave near field enhancements for surface breaking defects in plates
Near field surface wave ultrasonic enhancements have previously been used to detect surface breaking defects in thick samples using Rayleigh waves. Here, we present analogous surface wave enhancements for Lamb waves propagating in plates. By tracking frequency intensities in selected regions of time-frequency representations, we observe frequency enhancement in the near field, due to constructive interference of the incident wave mode with those reflected and mode converted at the defect. This is explained using two test models; a square based notch and an opening crack, which are used to predict the contribution to the out-of-plane displacement from the reflected and mode converted waves. This method has the potential to provide a reliable method for the near field identification and characterisation of surface breaking defects in plates
The Pedagogy of Digital Storytelling in the College Classroom
In the fall of 2008, Rachel Raimist and Walter Jacobs collaboratively designed and taught the course “Digital Storytelling in and with Communities of Color” to 18 undergraduate students from a variety of disciplines. Candance Doerr-Stevens audited the class as a graduate student. This article examines the media making processes of the students in the course, asking how participants used digital storytelling to engage with themselves and the media through content creation that both mimicked and critiqued current media messages. In particular, students used the medium of digital storytelling to build and revise identities for purposes of rememory, reinvention, and cultural remixing. We provide a detailed online account of the digital stories and composing processes of the students through the same multimedia genre that the students were asked to use, that of digital storytelling
Forager bees (Apis mellifera) highly express immune and detoxification genes in tissues associated with nectar processing.
Pollinators, including honey bees, routinely encounter potentially harmful microorganisms and phytochemicals during foraging. However, the mechanisms by which honey bees manage these potential threats are poorly understood. In this study, we examine the expression of antimicrobial, immune and detoxification genes in Apis mellifera and compare between forager and nurse bees using tissue-specific RNA-seq and qPCR. Our analysis revealed extensive tissue-specific expression of antimicrobial, immune signaling, and detoxification genes. Variation in gene expression between worker stages was pronounced in the mandibular and hypopharyngeal gland (HPG), where foragers were enriched in transcripts that encode antimicrobial peptides (AMPs) and immune response. Additionally, forager HPGs and mandibular glands were enriched in transcripts encoding detoxification enzymes, including some associated with xenobiotic metabolism. Using qPCR on an independent dataset, we verified differential expression of three AMP and three P450 genes between foragers and nurses. High expression of AMP genes in nectar-processing tissues suggests that these peptides may contribute to antimicrobial properties of honey or to honey bee defense against environmentally-acquired microorganisms. Together, these results suggest that worker role and tissue-specific expression of AMPs, and immune and detoxification enzymes may contribute to defense against microorganisms and xenobiotic compounds acquired while foraging
Cross-modal associations in synaesthesia: vowel colours in the ear of the beholder
Human speech conveys many forms of information, but for some exceptional individuals (synaesthetes), listening to speech sounds can automatically induce visual percepts such as colours. In this experiment, grapheme–colour synaesthetes and controls were asked to assign colours, or shades of grey, to different vowel sounds. We then investigated whether the acoustic content of these vowel sounds influenced participants’ colour and grey-shade choices. We found that both colour and grey-shade associations varied systematically with vowel changes. The colour effect was significant for both participant groups, but significantly stronger and more consistent for synaesthetes. Because not all vowel sounds that we used are “translatable” into graphemes, we conclude that acoustic–phonetic influences co-exist with established graphemic influences in the cross-modal correspondences of both synaesthetes and non-synaesthetes
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