This volume of interdisciplinary essays reflect current contributions to literary anthropology. Novel Approaches to Anthropology: Contributions to Literary Anthropology showcases the myriad ways that ...anthropologists bring their disciplinary perspectives, theories, concepts, and pedagogical strategies to interpreting fiction and travel writing written in the past and present. The authors integrate insights from the reflexive deconstructive turn in anthropology and from critical Marxist and feminist approaches that ground interpretation in the political, economic, and social constraints and experiences of everyday life. The contributors share the view that fiction, like all artistic expression, is rooted in specific historical and cultural contexts. Literature, like all artistic expression, stimulates a critical imagination by allowing readers to take a fresh look at their own society and culture.
Scanning alanine mutagenesis has been used to study the structural determinants of several activities of bothropstoxin-I (BthTx-I), a lysine 49 Phospholipases A
2 from the venom of
Bothrops ...jararacussu. A total of 31 mutants were generated in the interfacial recognition site and C-terminal loop regions of the protein. The effects of mutagenesis on the
in vivo myotoxic activity, the cytolytic activity against cultured C2C12 myoblasts, the bactericidal activity, and the Ca
2+-independent membrane damaging activity against liposome membranes were compared. Residues 116–119 and 122–125 in the C-terminal loop region are structural determinants for these activities, indicating that membrane permeabilization by the BthTx-I is an important general property in all the measured effects. The structural determinants of myotoxicity and myoblast membrane permeabilization are highly correlated, demonstrating that cultured C2C12 myoblasts are a good model for the myotoxic effect. However, comparison of the structural determinants for all activities revealed several differences in the structural determinants between the effects against myoblast and bacterial membranes, and further differences when compared to the liposome membrane damaging effect. These membrane dependent effects are interpreted to be the consequence of differences in the activation of the membrane bound form of the protein on biological and artificial membranes.
Voltage-activated K
(K
) channels play an important role in regulating the membrane potential in excitable cells. In gastrointestinal (GI) smooth muscles, these channels are particularly important in ...modulating spontaneous electrical activities. The purpose of this study was to identify the molecular components that may be responsible for the K
currents found in the canine GI tract. In this report, we have examined the qualitative expression of eighteen different K
channel genes in canine GI smooth muscle cells at the transcriptional level using RT-PCR analysis. Our results demonstrate the expression of K
1.4, K
1.5, K
1.6, K
2.2, and K
4.3 transcripts in all regions of the GI tract examined. Transcripts encoding K
1.2, K
β1.1, and K
β1.2 subunits were differentially expressed. K
1.1, K
1.3, K
2.1, K
3.1, K
3.2, K
3.4, K
4.1, K
4.2, and K
β2.1 transcripts were not detected in any GI smooth muscle cells. We have also determined the protein expression for a subset of these K
channel subunits using specific antibodies by immunoblotting and immunohistochemistry. Immunoblotting and immunohistochemistry demonstrated that K
1.2, K
1.4, K
1.5, and K
2.2 are expressed at the protein level in GI tissues and smooth muscle cells. K
2.1 was not detected in any regions of the GI tract examined. These results suggest that the wide array of electrical activity found in different regions of the canine GI tract may be due in part to the differential expression of K
channel subunits.
RNA interference (RNAi) is a post-transcriptional, sequence- specific gene-silencing technology that utilises double stranded (dsRNA) molecules to degrade messenger RNA containing the same sequence ...as the dsRNA. Although a significant body of research has been undertaken in the field of suppression (utilising RNAi) in mammalian cells and animals, in the majority of these studies synthetic siRNAs or else polymerase III promoter-driven shRNAs have been utilised. Notably, neither of these methods allow for temporal or spatial control of suppression. Whilst there are some studies describing methods of conditional RNAi (e.g. using cre recombinase), the current study represents the first demonstration of a single plasmid with components that enable tissue specific suppression in vitro and in vivo. In essence, the approach combines tissue specific polymerase II promoters with cis-acting hammerhead ribozymes and short-hairpin RNA (shRNA) sequences to generate potent dsRNA molecules in tissues defined by the promoter in use. Results in cell culture and in mice demonstrating that the approach outlined above can be utilized to provide tissue specific RNAi will be presented. More specifically, potent suppression of EGFP expression has been demonstrated in mouse kidney and liver using a cmv promoter driven shRNA construct, whilst an albumin promoter driven shRNA construct has been shown to elicit suppression only in mouse liver. Tissue-specific RNAi has several advantages over traditional methods not least of which is the ability to minimise off-target effects of RNAi. Additionally, tissue-specific RNAi, in principle, greatly increases the resolution of RNAi technology facilitating the ability to silence genes in individual tissues which, if down-regulated in all tissue types, may be lethal.
High-contrast imaging has afforded astronomers the opportunity to study light directly emitted by adolescent (tens of Myr) and ``proto" (\(<\)10Myr) planets still undergoing formation. Direct ...detection of these planets is enabled by empirical Point Spread Function (PSF) modeling and removal algorithms. The computational intensity of such algorithms, and their multiplicity of tunable input parameters, has led to the prevalence of ad-hoc optimization approaches to high-contrast imaging results. In this work, we present a new, systematic approach to optimization vetted using data of the high-contrast stellar companion HD 142527 B from the Magellan Adaptive Optics (MagAO) Giant Accreting Protoplanet Survey (GAPlanetS). More specifically, we present a grid search technique designed to explore three influential parameters of the PSF-subtraction algorithm pyKLIP -- annuli, movement, and KL modes. We consider multiple metrics for post-processed image quality in order to optimally recover at H\(\alpha\) (656nm) synthetic planets injected into contemporaneous continuum (643nm) images. These metrics include: peak (single-pixel) SNR, average (multi-pixel average) SNR, 5\(\sigma\) contrast, and false-positive fraction. We apply continuum-optimized KLIP reduction parameters to six H\(\alpha\) direct detections of the low-mass stellar companion HD142527 B, and recover the companion at a range of separations. Relative to a single-informed, non-optimized set of KLIP parameters applied to all datasets uniformly, our multi-metric grid search optimization led to improvements in companion SNR of up to 1.2\(\sigma\), with an average improvement of 0.6\(\sigma\). Since many direct imaging detections lie close to the canonical 5\(\sigma\) threshold, even such modest improvements may result in higher yields in future imaging surveys.
Accreting protoplanets represent a window into planet formation processes. We report H{\alpha} differential imaging results from the deepest and most comprehensive accreting protoplanet survey to ...date, acquired with the Magellan Adaptive Optics (MagAO) system's VisAO camera. The fourteen transitional disks targeted are ideal candidates for protoplanet discovery due to their wide, heavily depleted central cavities, wealth of non-axisymmetric circumstellar disk features evocative of ongoing planet formation, and ongoing stellar accretion. To address the twin challenges of morphological complexity in the target systems and PSF instability, we develop novel approaches for frame selection and optimization of the Karhounen-Loeve Image Processing algorithm pyKLIP. We detect one new candidate protoplanet, CS Cha "c", at a separation of 75mas and a Delta mag of 5.1 and robustly recover the HD142527 B and HD100453 B low mass stellar companions across multiple epochs. Though we cannot rule out a substantial scattered light contribution to its emission, we also recover LkCa 15 b. Its presence inside of the cleared disk cavity and consistency with a forward-modeled point source suggest that it remains a viable protoplanet candidate. The protoplanet PDS 70 c was marginally recovered under our conservative general methodology. However, through targeted optimization in H-alpha} imagery, we tentatively recover PDS 70 c in three epochs and PDS 70 b in one epoch. Of the many other previously-reported companions and companion candidates around objects in the sample, we do not recover any additional robust candidates. However, lack of recovery at moderate H-alpha contrast does not rule out the presence of protoplanets at these locations, and we report limiting H-alpha contrasts in such cases.
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