342 research outputs found
âScandalously bifurcated garmentsâ: Ecocriticism, American Pioneers, and Novelizing Women of the West
While the Western novel is typically associated with cowboys and overarching masculine accomplishments of âsettling,â the representation of womenâs work beyond narratives of being âtamedâ and the settling-down of motherhood has been overlooked by writers and ecocritics alike. Ecofeminist scholarship of the late 1980s and â90s, primed to take up such questions, focused primarily on the relationship between women and nature in abstract terms rather than on regionally-specific interpretations. This thesis, therefore, examines the representation of female-identifying protagonists in pioneer narratives of North America in three popular novels of the last century: Zane Greyâs posthumous Woman of the Frontier (1940/1998), Mrs. Mike (1947) by Benedict and Nancy Freedman, and the Oregon-specific Little Century (2011) by Anna Keesey. Using principles from feminist and ecocritical literary theory in combination, I consider the ways in which landscape is conscripted to convey a characterâs interiorityâan anthropocentric tactic that ultimately equates the objectification of women with the conquest of territory. As a twenty-first century pioneer woman born and raised on a rural Oregon ranch, identifying the significance of pioneer women and interrogating their representations beyond being extensions of the tamed landscape helps rewrite the conventional masculine lens of Manifest Destiny and the âWest.
Fibrinogen αCâregions are not directly involved in fibrin polymerization as evidenced by a "DoubleâDetroit" recombinant fibrinogen mutant and knobsâmimic peptides
Background:
Fibrin polymerization, following fibrinopeptides A and B (FpA, FpB) cleavage, relies on newly exposed αâ and ÎČâchains Nâtermini (GPR, GHR; Aâ, Bâknobs, respectively) engaging preâexistent a and b pockets in other fibrin(ogen) molecules' Îłâ and (B)ÎČâchains Câterminal regions. A role for mostly disordered (A)αâchains Câterminal regions "bridging" between fibrin molecules/fibrils has been proposed.
Objectives:
Fibrinogen Detroit is a clinically observed mutation (AαR19âS) with nonâengaging GPS Aâknobs. By analogy, a similar BÎČâchain mutation, BÎČR17âS, should produce nonâengaging GHS Bâknobs. A homozygous âDoubleâDetroitâ mutant (AαR19âS, BÎČR17âS; DDâFG) was developed: with Aâa and Bâb engagements endogenously blocked, other interactions would become apparent.
Methods:
DDâFG, wildâtype recombinant (WTâFG), and human plasma (hpâFG) fibrinogen selfâassociation was studied by turbidimetry coupled with fibrinopeptides release HPLC/mass spectrometry analyses, and by lightâscattering following sizeâexclusion chromatography (SEâHPLC).
Results:
In contrast to WTâFG and hpâFG, DDâFG produced no turbidity increase, irrespective of thrombin concentration. The SEâHPLC profile of concentrated DDâFG was unaffected by thrombin treatment, and lightâscattering, at lower concentration, showed no intensity and hydrodynamic radius changes. Compared with hpâFG, both WTâFG and DDâFG showed no FpA cleavage difference, while ~50% FpB was not recovered. Correspondingly, SDSâPAGE/Westernâblots revealed partial BÎČâchain Nâterminal and Aαâchain Câterminal degradation. Nevertheless, ~70% DDâFG molecules bearing (A)αCâregions potentially able to associate were available. Higherâconcentration, nearlyâintact hpâFG with 500âfold molar excess GPRPâNH2/GHRPâNH2 knobsâmimics experiments confirmed these noâassociations findings.
Conclusions:
(A)αCâregions interactions appear too weak to assist native fibrin polymerization, at least without knobs engagement. Their role in all stages should be carefully reconsidered
Zero-field spin splitting in InAs-AlSb quantum wells revisited
We present magnetotransport experiments on high-quality InAs-AlSb quantum
wells that show a perfectly clean single-period Shubnikov-de Haas oscillation
down to very low magnetic fields. In contrast to theoretical expectations based
on an asymmetry induced zero-field spin splitting, no beating effect is
observed. The carrier density has been changed by the persistent photo
conductivity effect as well as via the application of hydrostatic pressure in
order to influence the electric field at the interface of the electron gas.
Still no indication of spin splitting at zero magnetic field was observed in
spite of highly resolved Shubnikov- de Haas oscillations up to filling factors
of 200. This surprising and unexpected result is discussed in view of other
recently published data.Comment: 4 pages, 3 figures, submitted to Phys. Rev.
Nutritional implications of olives and sugar: attenuation of post-prandial glucose spikes in healthy volunteers by inhibition of sucrose hydrolysis and glucose transport by oleuropein
Purpose: The secoiridoid oleuropein, as found in olives and olive leaves, modulates some biomarkers of diabetes risk in vivo. A possible mechanism may be to attenuate sugar digestion and absorption.
Methods: We explored the potential of oleuropein, prepared from olive leaves in a water soluble form (OLE), to inhibit digestive enzymes (α-amylase, maltase, sucrase), and lower [ÂčâŽC(U)]-glucose uptake in Xenopus oocytes expressing human GLUT2 and [ÂčâŽC(U)]-glucose transport across differentiated Caco-2 cell monolayers. We conducted 7 separate crossover, controlled, randomised intervention studies on healthy volunteers (double-blinded and placebo-controlled for the OLE supplement) to assess the effect of OLE on post-prandial blood glucose after consumption of bread, glucose or sucrose.
Results: OLE inhibited intestinal maltase, human sucrase, glucose transport across Caco-2 monolayers, and uptake of glucose by GLUT2 in Xenopus oocytes, but was a weak inhibitor of human α-amylase. OLE, in capsules, in solution or as naturally present in olives, did not affect post-prandial glucose derived from bread, while OLE in solution attenuated post-prandial blood glucose after consumption of 25 g sucrose, but had no effect when consumed with 50 g of sucrose or glucose.
Conclusion: The combined inhibition of sucrase activity and of glucose transport observed in vitro was sufficient to modify digestion of low doses of sucrose in healthy volunteers. In comparison, the weak inhibition of α-amylase by OLE was not enough to modify blood sugar when consumed with a starch-rich food, suggesting that a threshold potency is required for inhibition of digestive enzymes in order to translate into in vivo effects
Quantitative trait loci conferring grain mineral nutrient concentrations in durum wheat 3 wild emmer wheat RIL population
Mineral nutrient malnutrition, and particularly
deficiency in zinc and iron, afflicts over 3 billion people
worldwide. Wild emmer wheat, Triticum turgidum ssp.
dicoccoides, genepool harbors a rich allelic repertoire for
mineral nutrients in the grain. The genetic and physiological
basis of grain protein, micronutrients (zinc, iron,
copper and manganese) and macronutrients (calcium,
magnesium, potassium, phosphorus and sulfur) concentration
was studied in tetraploid wheat population of 152
recombinant inbred lines (RILs), derived from a cross
between durum wheat (cv. Langdon) and wild emmer
(accession G18-16). Wide genetic variation was found
among the RILs for all grain minerals, with considerable
transgressive effect. A total of 82 QTLs were mapped for
10 minerals with LOD score range of 3.2â16.7. Most QTLs
were in favor of the wild allele (50 QTLs). Fourteen pairs
of QTLs for the same trait were mapped to seemingly
homoeologous positions, reflecting synteny between the A
and B genomes. Significant positive correlation was found
between grain protein concentration (GPC), Zn, Fe and Cu,
which was supported by significant overlap between the
respective QTLs, suggesting common physiological and/or
genetic factors controlling the concentrations of these
mineral nutrients. Few genomic regions (chromosomes 2A,
5A, 6B and 7A) were found to harbor clusters of QTLs for
GPC and other nutrients. These identified QTLs may
facilitate the use of wild alleles for improving grain
nutritional quality of elite wheat cultivars, especially in
terms of protein, Zn and Fe
Genetic diversity in natural populations of Jacaranda decurrens Cham. determined using RAPD and AFLP markers
Jacaranda decurrens (Bignoniaceae) is an endemic species of the Cerrado with validated antitumoral activity. The genetic diversity of six populations of J. decurrens located in the State of SĂŁo Paulo was determined in this study by using molecular markers for randomly amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP). Following optimization of the amplification reaction, 10 selected primers generated 78 reproducible RAPD fragments that were mostly (69.2%) polymorphic. Two hundred and five reproducible AFLP fragments were generated by using four selected primer combinations; 46.3% of these fragments were polymorphic, indicating a considerable level of genetic diversity. Analysis of molecular variance (AMOVA) using these two groups of markers indicated that variability was strongly structured amongst populations. The unweighted pair group method with arithmatic mean (UPGMA) and Pearson's correlation coefficient (RAPD -0.16, p = 0.2082; AFLP 0.37, p = 0.1006) between genetic matrices and geographic distances suggested that the population structure followed an island model in which a single population of infinite size gave rise to the current populations of J. decurrens, independently of their spatial position. The results of this study indicate that RAPD and AFLP markers were similarly efficient in measuring the genetic variability amongst natural populations of J. decurrens. These data may be useful for developing strategies for the preservation of this medicinal species in the Cerrado
Combating the effects of climatic change on forests by mitigation strategies
<p>Abstract</p> <p>Background</p> <p>Forests occur across diverse biomes, each of which shows a specific composition of plant communities associated with the particular climate regimes. Predicted future climate change will have impacts on the vulnerability and productivity of forests; in some regions higher temperatures will extend the growing season and thus improve forest productivity, while changed annual precipitation patterns may show disadvantageous effects in areas, where water availability is restricted. While adaptation of forests to predicted future climate scenarios has been intensively studied, less attention was paid to mitigation strategies such as the introduction of tree species well adapted to changing environmental conditions.</p> <p>Results</p> <p>We simulated the development of managed forest ecosystems in Germany for the time period between 2000 and 2100 under different forest management regimes and climate change scenarios. The management regimes reflect different rotation periods, harvesting intensities and species selection for reforestations. The climate change scenarios were taken from the IPCC's Special Report on Emission Scenarios (SRES). We used the scenarios A1B (rapid and successful economic development) and B1 (high level of environmental and social consciousness combined with a globally coherent approach to a more sustainable development). Our results indicate that the effects of different climate change scenarios on the future productivity and species composition of German forests are minor compared to the effects of forest management.</p> <p>Conclusions</p> <p>The inherent natural adaptive capacity of forest ecosystems to changing environmental conditions is limited by the long life time of trees. Planting of adapted species and forest management will reduce the impact of predicted future climate change on forests.</p
The role of melatonin in the pathogenesis of adolescent idiopathic scoliosis (AIS)
The cause of adolescent idiopathic scoliosis (AIS) in humans remains obscure and probably multifactorial. At present, there is no proven method or test available to identify children or adolescent at risk of developing AIS or identify which of the affected individuals are at risk of progression. Reported associations are linked in pathogenesis rather than etiologic factors. Melatonin may play a role in the pathogenesis of scoliosis (neuroendocrine hypothesis), but at present, the data available cannot clearly show the role of melatonin in producing scoliosis in humans. The data regarding human melatonin levels are mixed at best, and the melatonin deficiency as a causative factor in the etiology of scoliosis cannot be supported. It will be an important issue of future research to investigate the role of melatonin in human biology, the clinical efficacy, and safety of melatonin under different pathological situations. Research is needed to better define the role of all factors in AIS development
Tangential beam IMRT versus tangential beam 3D-CRT of the chest wall in postmastectomy breast cancer patients: A dosimetric comparison
<p>Abstract</p> <p>Background</p> <p>This study evaluates the dose distribution of reversed planned tangential beam intensity modulated radiotherapy (IMRT) compared to standard wedged tangential beam three-dimensionally planned conformal radiotherapy (3D-CRT) of the chest wall in unselected postmastectomy breast cancer patients</p> <p>Methods</p> <p>For 20 unselected subsequent postmastectomy breast cancer patients tangential beam IMRT and tangential beam 3D-CRT plans were generated for the radiotherapy of the chest wall. The prescribed dose was 50 Gy in 25 fractions. Dose-volume histograms were evaluated for the PTV and organs at risk. Parameters of the dose distribution were compared using the Wilcoxon matched pairs test.</p> <p>Results</p> <p>Tangential beam IMRT statistically significantly reduced the ipsilateral mean lung dose by an average of 21% (1129 cGy versus 1437 cGy). In all patients treated on the left side, the heart volume encompassed by the 70% isodose line (V70%; 35 Gy) was reduced by an average of 43% (5.7% versus 10.6%), and the mean heart dose by an average of 20% (704 cGy versus 877 cGy). The PTV showed a significantly better conformity index with IMRT; the homogeneity index was not significantly different.</p> <p>Conclusions</p> <p>Tangential beam IMRT significantly reduced the dose-volume of the ipsilateral lung and heart in unselected postmastectomy breast cancer patients.</p
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