77 research outputs found
Mars manned fusion spaceship
Fusion Propulsion has an enormous potential for space exploration in the near future. In the twenty-first century, a usable and efficient fusion rocket will be developed and in use. Because of the great distance between other planets and Earth, efficient use of time, fuel, and payload is essential. A nuclear spaceship would provide greater fuel efficiency, less travel time, and a larger payload. Extended missions would give more time for research, experiments, and data acquisition. With the extended mission time, a need for an artificial environment exists. The topics of magnetic fusion propulsion, living modules, artificial gravity, mass distribution, space connection, and orbital transfer to Mars are discussed. The propulsion system is a magnetic fusion reactor based on a tandem mirror design. This allows a faster, shorter trip time and a large thrust to weight ratio. The fuel proposed is a mixture of deuterium and helium-3. Helium-3 can be obtained from lunar mining. There will be minimal external radiation from the reactor resulting in a safe, efficient propulsion system
\u3cem\u3eBataclanismo\u3c/em\u3e! Or, How Deco Bodies Transformed Postrevolutionary Mexico City
In the spring of 1925, Santa Anita\u27s Festival of Flowers seemed to follow its tranquil trend of previous years. The large displays of flowers, the selection of indias bonitas (as the contestants of beauty pageants organized in an attempt to stimulate indigenism were known) and the boat-rides on the Viga Canal, all communicated what residents of neighboring Mexico City had come to expect of the small pueblo in the Federal District since the Porfiriato: the respite of a peaceful pastoral, the link to a colorful past, and the promise that mexicanidad was alive and well in the campo. Unfortunately, wrote Manuel Rámirez Cárdenas of El Globo, the modern newspaper, the next day, this idyllic tradition was rudely interrupted by a group of audacious, scantily clad women. The culprits were actresses of Mexico City\u27s LÃrico theater, who walked around Santa Anita\u27s streets in picaresque clothing —stage outfits that left little to the imagination, particularly in broad daylight—and upset visitors and campesinos alike. According to Cárdenas, abuelitas and mamás were shocked by the display, averting their eyes from the female spectacle in fear of el pecado mortal. Thankfully, for the mothers and grandmothers in the audience, the festival continued in predictable fashion after the initial uproar. Organizers continued with the traditional dances, and judges selected an india bonita from a pool of young, decente mestizo girls to represent the pueblo and the festival.
Unbeknownst to the residents of rural Santa Anita, the daring actresses of El LÃrico were part of a new phenomenon that had swept through Mexico City like wildfire, turned the entertainment world upside down, and pushed many to reconsider what constituted female beauty, decency, and lo mexicano. A few months earlier, on February 12th, a grand variety spectacle named Voilá Paris: La Ba-ta-clán premiered in Teatro Iris and instantly sent shock waves throughout the Mexican entertainment world and the larger metropolis. The show featured seminude and nude French actresses, who performed dances and acts that appeared to be a mix of classical ballet, Ziegfeld Follies chorus lines, and tableaux vivants. Within weeks, Mexican copycat productions capitalized on the enormous success of the show, triggering a new entertainment phenomenon named after the original production: Bataclanismo. It also launched a new kind of female star, the bataclana, who came to represent the erotic, and more dangerous, attributes of the flapper for Mexican audiences, and whose body became the site of contested and divergent notions of modernity.
In this article, I explore bataclanismo as a normative discourse that reached far beyond the theater into the practice of everyday life. I do so to gauge the transition of changing ideals of femininity in Mexico from 1925 to 1935, and the influence these changes had on the development of urban space. Drawing on Elizabeth Grosz\u27 and Doreen Massey\u27s insights that place and gender are mutually constitutive, this article examines the articulation between the embodied city and changing gender norms in the wake of both the Mexican revolution and the advent of twentieth-century global capital. Analyzing these relationships from Judith Butler\u27s perspective of gender performance, especially as read through bodies, I argue that a new transnational aesthetic of feminine embodiment celebrated in bataclanismo influenced a distinct urban modernity and sociability in Mexico City. This new ideal female physique that stressed length, height, and androgyny—what I term a Deco body—helped to reconfigure Mexico City in terms of gender, space and race. It ushered in new gender ideals, helped visualize urban modernity, and bridged the gap between two divergent discourses that accompanied revolutionary reform, indigenismo and mestizaje, paving the way for a mestizo modernity
A reference database for tumor-related genes co-expressed with interleukin-8 using genome-scale in silico analysis
BACKGROUND: The EST database provides a rich resource for gene discovery and in silico expression analysis. We report a novel computational approach to identify co-expressed genes using EST database, and its application to IL-8. RESULTS: IL-8 is represented in 53 dbEST cDNA libraries. We calculated the frequency of occurrence of all the genes represented in these cDNA libraries, and ranked the candidates based on a Z-score. Additional analysis suggests that most IL-8 related genes are differentially expressed between non-tumor and tumor tissues. To focus on IL-8's function in tumor tissues, we further analyzed and ranked the genes in 16 IL-8 related tumor libraries. CONCLUSIONS: This method generated a reference database for genes co-expressed with IL-8 and could facilitate further characterization of functional association among genes
Identification of the tyrosine phosphatase PTP-MEG2 as an antagonist of hepatic insulin signaling
SummaryInsulin resistance is a primary defect in type 2 diabetes characterized by impaired peripheral glucose uptake and insufficient suppression of hepatic glucose output. Insulin signaling inhibits liver glucose production by inducing nuclear exclusion of the gluconeogenic transcription factor FOXO1 in an Akt-dependent manner. Through the concomitant application of genome-scale functional screening and quantitative image analysis, we have identified PTP-MEG2 as a modulator of insulin-dependent FOXO1 subcellular localization. Ectopic expression of PTP-MEG2 in cells inhibited insulin-induced phosphorylation of the insulin receptor, while RNAi-mediated reduction of PTP-MEG2 transcript levels enhanced insulin action. Additionally, adenoviral-mediated depletion of PTP-MEG2 in livers of diabetic (db/db) mice resulted in insulin sensitization and normalization of hyperglycemia. These data implicate PTP-MEG2 as a mediator of blood glucose homeostasis through antagonism of insulin signaling, and suggest that modulation of PTP-MEG2 activity may be an effective strategy in the treatment of type 2 diabetes
Disk-Jet Connection in the Radio Galaxy 3C 120
We present the results of extensive multi-frequency monitoring of the radio
galaxy 3C 120 between 2002 and 2007 at X-ray, optical, and radio wave bands, as
well as imaging with the Very Long Baseline Array (VLBA). Over the 5 yr of
observation, significant dips in the X-ray light curve are followed by
ejections of bright superluminal knots in the VLBA images. Consistent with
this, the X-ray flux and 37 GHz flux are anti-correlated with X-ray leading the
radio variations. This implies that, in this radio galaxy, the radiative state
of accretion disk plus corona system, where the X-rays are produced, has a
direct effect on the events in the jet, where the radio emission originates.
The X-ray power spectral density of 3C 120 shows a break, with steeper slope at
shorter timescale and the break timescale is commensurate with the mass of the
central black hole based on observations of Seyfert galaxies and black hole
X-ray binaries. These findings provide support for the paradigm that black hole
X-ray binaries and active galactic nuclei are fundamentally similar systems,
with characteristic time and size scales linearly proportional to the mass of
the central black hole. The X-ray and optical variations are strongly
correlated in 3C 120, which implies that the optical emission in this object
arises from the same general region as the X-rays, i.e., in the accretion
disk-corona system. We numerically model multi-wavelength light curves of 3C
120 from such a system with the optical-UV emission produced in the disk and
the X-rays generated by scattering of thermal photons by hot electrons in the
corona. From the comparison of the temporal properties of the model light
curves to that of the observed variability, we constrain the physical size of
the corona and the distances of the emitting regions from the central BH.Comment: Accepted for publication in the Astrophysical Journal. 28 pages, 21
figures, 2 table
Restriction associated DNA-genotyping at multiple spatial scales in Arabidopsis lyrata reveals signatures of pathogen-mediated selection
Background: Genome scans based on outlier analyses have revolutionized detection of genes involved in adaptive processes, but reports of some forms of selection, such as balancing selection, are still limited. It is unclear whether high throughput genotyping approaches for identification of single nucleotide polymorphisms have sufficient power to detect modes of selection expected to result in reduced genetic differentiation among populations. In this study, we used Arabidopsis lyrata to investigate whether signatures of balancing selection can be detected based on genomic smoothing of Restriction Associated DNA sequencing (RAD-seq) data. We compared how different sampling approaches (both within and between subspecies) and different background levels of polymorphism (inbreeding or outcrossing populations) affected the ability to detect genomic regions showing key signatures of balancing selection, specifically elevated polymorphism, reduced differentiation and shifts towards intermediate allele frequencies. We then tested whether candidate genes associated with disease resistance (R-gene analogs) were detected more frequently in these regions compared to other regions of the genome.
Results: We found that genomic regions showing elevated polymorphism contained a significantly higher density of R-gene analogs predicted to be under pathogen-mediated selection than regions of non-elevated polymorphism, and that many of these also showed evidence for an intermediate site-frequency spectrum based on Tajima’s D. However, we found few genomic regions that showed both elevated polymorphism and reduced FST among populations, despite strong background levels of genetic differentiation among populations. This suggests either insufficient power to detect the reduced population structure predicted for genes under balancing selection using sparsely distributed RAD markers, or that other forms of diversifying selection are more common for the R-gene analogs tested.
Conclusions: Genome scans based on a small number of individuals sampled from a wide range of populations were sufficient to confirm the relative scarcity of signatures of balancing selection across the genome, but also identified new potential disease resistance candidates within genomic regions showing signatures of balancing selection that would be strong candidates for further sequencing efforts
Flexible and Stretchable Bioelectronics
Medical science technology has improved tremendously over the decades with the invention of robotic surgery, gene editing, immune therapy, etc. However, scientists are now recognizing the significance of ‘biological circuits’ i.e., bodily innate electrical systems for the healthy functioning of the body or for any disease conditions. Therefore, the current trend in the medical field is to understand the role of these biological circuits and exploit their advantages for therapeutic purposes. Bioelectronics, devised with these aims, work by resetting, stimulating, or blocking the electrical pathways. Bioelectronics are also used to monitor the biological cues to assess the homeostasis of the body. In a way, they bridge the gap between drug-based interventions and medical devices. With this in mind, scientists are now working towards developing flexible and stretchable miniaturized bioelectronics that can easily conform to the tissue topology, are non-toxic, elicit no immune reaction, and address the issues that drugs are unable to solve. Since the bioelectronic devices that come in contact with the body or body organs need to establish an unobstructed interface with the respective site, it is crucial that those bioelectronics are not only flexible but also stretchable for constant monitoring of the biological signals. Understanding the challenges of fabricating soft stretchable devices, we review several flexible and stretchable materials used as substrate, stretchable electrical conduits and encapsulation, design modifications for stretchability, fabrication techniques, methods of signal transmission and monitoring, and the power sources for these stretchable bioelectronics. Ultimately, these bioelectronic devices can be used for wide range of applications from skin bioelectronics and biosensing devices, to neural implants for diagnostic or therapeutic purposes
Temperature-Dependence of Metabolism and Fuel Selection from Cells to Whole Organisms
Temperature affects nearly every aspect of how organisms interact with and are constrained by their environment. Measures of organismal energetics, such as metabolic rate, are highly temperature-dependent and governed through temperature effects on rates of biochemical reactions. Characterizing the relationships among levels of biological organization can lend insight into how temperature affects whole-organism function. We tested the temperature dependence of cellular oxygen consumption and its relationship to whole-animal metabolic rate in garter snakes (Thamnophis elegans). Additionally, we tested whether thermal responses were linked to shifts in the fuel source oxidized to support metabolism with the use of carbon stable isotopes. Our results demonstrate temperature dependence of metabolic rates across levels of biological organization. Cellular (basal, adenosine triphosphate-linked) and whole-animal rates of respiration increased with temperature but were not correlated within or among individuals, suggesting that variation in whole-animal metabolic rates is not due simply to variation at the cellular level, but rather other interacting factors across scales of biological organization. Counter to trends observed during fasting, elevated temperature did not alter fuel selection (i.e., natural-abundance stable carbon isotope composition in breath, δ13Cbreath). This consistency suggests the maintenance and oxidation of a single fuel source supporting metabolism across a broad range of metabolic demands
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Cyclophosphamide/Fludarabine (CF) is Active in the Treatment of Mantle Cell Lymphoma
The purpose of this study was to determine the efficacy and toxicity of the cyclophosphamide and fludarabine (CF) regimen in patients with newly diagnosed and relapsed/refractory mantle cell lymphoma (MCL). Thirty patients with pathologically confirmed MCL were treated with the CF regimen. Ten (33%) had no prior therapy, six (20%) had one previous regimen, and 14 (47%) received two or more prior regimens. Ninety cycles of CF with a median of 3 cycles/patient (range, 1-5 cycles) were administered to patients with MCL. Nine patients (30%) had a complete response (CR) and 10 (33%) had a partial response (PR) for an overall response rate (RR) of 63%. The median failure-free survival (FFS) and overall survival (OS) was 4.8 months and 17.5 months, respectively. When patients were analyzed based upon the number of previous treatments (0,1, or 2 or more), those with no previous treatment (n=10) had an overall response of 100%, with 70% CR. The median FFS was 28.1 months and the median OS for this group has not been reached at 42.3+ months. Hematologic and infectious toxicity were the major toxicities encountered with the CF regimen. Grade 3-4 neutropenia, thrombocytopenia and anemia were seen in 50%, 37%, and 36% of patients, respectively. There were 13 episodes of grade 3 infections. There was no treatment related mortality. In conclusion, the high response rate associated with the CF regimen merits further investigation in previously untreated patients with MCL, particularly in those who are not candidates for aggressive therapy
The Geometry of Taking Flight: Limb Morphometrics in Mesozoic theropods
Theropoda was one of the most successful dinosaurian clades during the Mesozoic and has remained a dominant component of faunas throughout the Cenozoic, with nearly 10,000 extant representatives. The discovery of Archaeopteryx provides evidence that avian theropods evolved at least 155 million years ago and that more than half of the tenure of avian theropods on Earth was during the Mesozoic. Considering the major changes in niche occupation for theropods resulting from the evolution of arboreal and flight capabilities, we have analyzed forelimb and hindlimb proportions among nonmaniraptoriform theropods, nonavian maniraptoriforms, and basal avialans using reduced major axis regressions, principal components analysis, canonical variates analysis, and discriminant function analysis. Our study is the first analysis on theropod limb proportions to apply phylogenetic independent contrasts and size corrections to the data to ensure that all the data are statistically independent and amenable to statistical analyses. The three ordination analyses we performed did not show any significant groupings or deviations between nonavian theropods and Mesozoic avian forms when including all limb elements. However, the bivariate regression analyses did show some significant trends between individual elements that suggested evolutionary trends of increased forelimb length relative to hindlimb length from nonmaniraptoriform theropods to nonavian maniraptoriforms to basal avialans. The increase in disparity and divergence away from the nonavian theropod body plan is well documented within Cenozoic forms. The lack of significant groupings among Mesozoic forms when examining the entire theropod body plan concurrently suggests that nonavian theropods and avian theropods did not substantially diverge in limb proportions until the Cenozoic. J. Morphol. 276:152-166, 2015
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