Phase-matched generation of coherent soft X-rays

Phase-matched harmonic conversion of visible laser light into soft x-rays was demonstrated. The recently developed technique of guided-wave frequency conversion was used to upshift light from 800 nanometers to the range from 17 to 32 nanometers. This process increased the coherent x-ray output by factors of 10(2) to 10(3) compared to the non-phase-matched case. This source uses a small-scale (sub-millijoule) high repetition-rate laser and will enable a wide variety of new experimental investigations in linear and nonlinear x-ray science.     

Comparative response of poppy (Papaver somniferum L.) and eight crop and vegetable species to manganese excess in solution culture

The relative response of poppy (Papaver somniferum L.) and eight crop and vegetable species to excess manganese was investigated in a glasshouse, solution culture experiment. Plant yields and manganese concentrations were measured after two and six weeks growth at five levels of manganese (10–800 μM).

Poppies were highly sensitive to manganese toxicity in solution culture and reductions in shoot yield occurred at lower manganese levels in solution and at lower shoot manganese concentrations than that for the following sensitive species, ranked in order of increasing tolerance : brussels sprout, barley, green beans, lucerne and grean pea. In contrast lupins, oats and sugar beet were relatively tolerant producing about 80% or more of maximum shoot yield at the highest solution manganese level (800 μM Mn).

In this study the sensitivity of poppy, and brussels sprout, to manganese excess was attributed to their low shoot manganese “toxicity threshold values”; and their capacity to partition a high proportion of total plant manganese and dry matter to the shoot at solution manganese levels ≥ 100 μM.

The application of these results to field grown poppy is discussed in relation to interactions between manganese and other elements which modify plant tolerance to manganese excess.     

Feline paraneoplastic syndrome associated with thymoma

CASE HISTORY: A 6-year-old, spayed, female, domestic short-haired cat presented with severe erythroderma and scaling skin. She showed disturbed gait and mild behavioural changes.

CLINICAL FINDINGS: The cat had a generalised, erythematous, scurfy dermatitis with marked, multifocal crusting and skin thickening. The skin was painful and contracted, which appeared to prevent normal freedom of movement.

DIAGNOSIS: The cat was suspected to have a paraneoplastic syndrome. A mediastinal mass was located and histologically confirmed as thymoma. The cat was diagnosed with a thymoma-associated cutaneous paraneoplastic syndrome.

CLINICAL RELEVANCE: This is a rare condition with few reports in the literature. The skin changes, both grossly and histologically, were considered to be different from those described in cases of paraneoplastic dermatosis associated with pancreatic neoplasia. The clinical presentation was characteristic and more cases may occur in practice than are recognised. In this case, as in previous reports, the tumour was grossly resectable, which could lead to cure of the clinical condition.     

Effects of crocin on frozen-thawed sperm apoptosis,protamine expression and membrane lipid oxidation in Yanbian yellow cattle

Glycerol is used as a bovine semen osmotic cryoprotectant that greatly improves the quality of frozen and thawed bovine sperm. However, high glycerol concentrations can have a toxic effect on frozen and thawed bovine sperm. Therefore, this experiment investigated the effect of replacing a portion of the glycerol in a cryoprotectant solution with crocin on the sperm apoptosis, protamine deficiency and membrane lipid oxidation of frozen and thawed Yanbian yellow cattle sperm. The experiment included a control group (6% glycerol) and four treatment groups: I (3% glycerol), II (3% glycerol +0.5 mM crocin), III (3% glycerol + 1 mM crocin) and IV (3% glycerol + 2 mM crocin). Computer assisted semen analysis was used to detect sperm motility, Hoechst 33,342, propidium iodide, and JC-1 staining were used to analyse sperm viability and mitochondrial membrane potential, chromomycin A3 staining was used to detect protamine deficiency and DNA damage, flow cytometry was used for sperm membrane lipid disorder detection and analysis, and real-time quantitative RT-qPCR was used to detect the mRNA expression levels of protamine-related genes (PRM2, PRM3), sperm acrosome-associated genes (SPACA3), oxidative stress-related genes (ROMO1) and apoptosis-related genes (BCL2, BAX). Compared to the control group, replacing a portion of glycerol with 1 mM crocin significantly improved sperm motility, plasma membrane integrity, membrane lipid disorders (p < .05) and viability, mitochondrial membrane potential, protamine deficiency (p < .01). The expression level of PRM2, PRM3, SPACA3 and BCL2 significantly increased (p < .05), while the expression levels of ROMO1 and BAX significantly decreased (p < .05). Accordingly, the BCL2/BAX ratio significantly increased (p < .05). In summary, the substitution of a portion of glycerol with crocin in cryoprotective solution improved the quality of Yanbian yellow cattle sperm after freezing and thawing.     

F2 screening for resistance to pyramided Bacillus thuringiensis maize in Louisiana and Mississippi populations of Diatraea saccharalis (Lepidoptera: Crambidae)

BACKGROUND: In the mid‐southern region of the United States, sugarcane borer, Diatraea saccharalis (F.), is a major target pest of transgenic maize expressing Bacillus thuringiensis (Bt) proteins. Novel transgenic maize technologies containing two or more pyramided Bt genes for controlling lepidopteran pests have recently become commercially available. Insect resistance management (IRM) is an important issue in the sustainable use of Bt crop technologies. The objective of this study was to determine the frequency of resistance alleles in field populations of D. saccharalis to the new pyramided Bt maize technologies. RESULTS: A total of 382 F₂ family lines derived from 735 feral larvae/pupae of D. saccharalis collected from six locations in Louisiana and Mississippi during 2008 and 2009 were screened for resistance to three new Bt maize technologies: MON 89034, Genuity? VT Triple Pro? and SmartStax?. None of the 382 F₂ isoline families survived on the Bt maize leaf tissue for ≥ 12 days in the F₂ screen. The joint frequency for two‐ or three‐gene resistance models with 95% probability in these populations was estimated to be < 0.0063 to MON 89034 and < 0.003 to VT Triple Pro? and SmartStax?. CONCLUSION: These results suggest that the resistance allele frequency in D. saccharalis to the three pyramided Bt maize technologies is low in the mid‐southern region of the United States, which should meet the rare resistance assumption of the currently used IRM strategy for Bt maize. Copyright © 2011 Society of Chemical Industry     

Endothelial cells stimulate self-renewal and expand neurogenesis of neural stem cells

Neural stem cells are reported to lie in a vascular niche, but there is no direct evidence for a functional relationship between the stem cells and blood vessel component cells. We show that endothelial cells but not vascular smooth muscle cells release soluble factors that stimulate the self-renewal of neural stem cells, inhibit their differentiation, and enhance their neuron production. Both embryonic and adult neural stem cells respond, allowing extensive production of both projection neuron and interneuron types in vitro. Endothelial coculture stimulates neuroepithelial cell contact, activating Notch and Hes 1 to promote self-renewal. These findings identify endothelial cells as a critical component of the neural stem cell niche.     

Linkage of dominant hypersensitive resistance to bean common mosaic virus to seed color in Phaseolus vulgaris L.

Summary Evaluation of Phaseolus vulgaris germplasm bank materials and progenies from a large number of crosses using red- or yellow-colored, BCMV-susceptible bean lines, crossed to purple- or grey/brown-colored, hypersensitive-resistant lines, suggested strong trait association between seed color and BCMV resistance. The cross of red-mottled I⁺I⁺ (susceptible) BAT 1255R to isogenic purple-mottled II (resistant) BAT 1255M was made to study the segregation of the two characters and to recover red-mottled resistant progenies. No recombinant genotypes were observed among 353 F₃ families inoculated with BCMV-NL3, suggesting that linkage of purple-mottled seed color and dominant BCMV resistance is very close.Contribution of the Centro Internacional de Agricultural Tropical.