University of Arkansas

About: University of Arkansas is a education organization based out in Fayetteville, Arkansas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 17225 authors who have published 33329 publications receiving 941102 citations. The organization is also known as: Arkansas & UA.

Rice SERK1 gene positively regulates somatic embryogenesis of cultured cell and host defense response against fungal infection

Abstract: Here we report on the isolation and characterization of a somatic embryogenesis receptor-like kinase (OsSERK1) gene in rice (Oryza sativa). The OsSERK1 gene belongs to a small subfamily of receptor-like kinase genes in rice and shares a highly conserved gene structure and extensive sequence homology with previously reported plant SERK genes. Though it has a basal level of expression in various rice organs/tissues, as high expression level was detected in rice callus during somatic embryogenesis. Suppression of OsSERK1 expression in transgenic calli by RNA interference resulted in a significant reduction of shoot regeneration rate (from 72% to 14% in the japonica rice Zhonghua11). Overexpression of OsSERK1, however, increased the shoot regeneration rate (from 72% to 86%). Interestingly, OsSERK1 is significantly activated by the rice blast fungus, particularly during the incompatible interaction, and is associated with host cell death in Sekigushi lesion mimic mutants. This gene is also inducible by defense signaling molecules such as salicylic acid, jasmonic acid, and abscisic acid. Furthermore, constitutive overexpression of OsSERK1 in two rice cultivars led to an increase in host resistance to the blast fungus. Our data suggest that OsSERK1 may partially mediate defense signal transduction in addition to its basic role in somatic embryogenesis.

Mild Dehydration Affects Mood in Healthy Young Women

Abstract: Limited information is available regarding the effects of mild dehydration on cognitive function. Therefore, mild dehydration was produced by intermittentmoderate exercise without hyperthermia and its effects on cognitive function of women were investigated. Twenty-five females (age 23.0 6 0.6 y) participated in three 8-h, placebo-controlled experiments involving a different hydration state each day: exercise-induced dehydration with no diuretic (DN), exerciseinduced dehydration plus diuretic (DD; furosemide, 40 mg), and euhydration (EU). Cognitive performance, mood, and symptoms of dehydration were assessed during each experiment, 3 times at rest and during each of 3 exercise sessions. The DN and DD trials in which a volunteer attained a $1% level of dehydration were pooled and compared to that volunteer’s equivalent EU trials. Mean dehydration achieved during these DN and DD trials was 21.36 6 0.16% of body mass. Significant adverse effects of dehydration were present at rest and during exercise for vigor-activity, fatigue-inertia, and total mood disturbance scores of the Profile of Mood States and for task difficulty, concentration, and headache as assessed by questionnaire. Most aspects of cognitive performance were not affected by dehydration. Serum osmolality, a marker of hydration, was greater in the mean of the dehydrated trials in which a $1% level of dehydration was achieved (P = 0.006) compared to EU. In conclusion, degraded mood, increased perception of task difficulty, lower concentration, and headache symptoms resulted from 1.36% dehydration in females. Increased emphasis on optimal hydration is warranted, especially during and after moderate exercise. J. Nutr. doi: 10.3945/jn.111.142000.

Quantifying the Coverage Density of Poly(ethylene glycol) Chains on the Surface of Gold Nanostructures

Abstract: The coverage density of poly(ethylene glycol) (PEG) is a key parameter in determining the efficiency of PEGylation, a process pivotal to in vivo delivery and targeting of nanomaterials. Here we report four complementary methods for quantifying the coverage density of PEG chains on various types of Au nanostructures by using a model system based on HS–PEG–NH2 with different molecular weights. Specifically, the methods involve reactions with fluorescamine and ninhydrin, as well as labeling with fluorescein isothiocyanate (FITC) and Cu2+ ions. The first two methods use conventional amine assays to measure the number of unreacted HS–PEG–NH2 molecules left behind in the solution after incubation with the Au nanostructures. The other two methods involve coupling between the terminal −NH2 groups of adsorbed −S–PEG–NH2 chains and FITC or a ligand for Cu2+ ion, and thus pertain to the “active” −NH2 groups on the surface of a Au nanostructure. We found that the coverage density decreased as the length of PEG chains...

Preserving accuracy in GenBank

Abstract: GenBank, the public repository for nucleotide and protein sequences, is a critical resource for molecular biology, evolutionary biology, and ecology. While some attention has been drawn to sequence errors ([1][1]), common annotation errors also reduce the value of this database. In fact, for