The Impact of Retail Light Source on Greening of Russet Burbank Potato Tubers

The use of accent lighting in retail stores has focused illumination on potatoes for greater consumer awareness. Unfortunately, this directed light on displayed potatoes may impact the rate or level of tuber greening. The objective of this study was to evaluate the influence of various retail accent light sources on greening and quality of illuminated tubers. Two separate experiments exposed ‘Russet Burbank’ potato tubers to fiber optic, ceramic metal halide, fluorescent, fluorescent with filter lighting (experiment 1) and fiber optic, halogen, and fluorescent lighting (experiment 2). In each experiment, tubers were exposed to a consistent light intensity (1390 lx in experiment 1 and 1300 lx in experiment 2) in addition to a dark control. Tubers were illuminated for 22 h per day at an ambient room temperature of 22 C. Six randomly selected tubers were evaluated for level of greening, chlorophyll concentration, and weight loss at day 0, 2, 4, 7, and 9. Total glycoalkaloid content was analyzed at days 0 and 9. In experiment 1, the fiber optic and fluorescent illuminated tubers showed significantly lower chlorophyll content compared to the ceramic metal halide light source. There was no significant difference in chlorophyll level or greening rating between the fluorescent light source and fluorescent with filter. In experiment 2, the fiber optic illuminated tubers had lower chlorophyll content and less visual greening compared to the halogen illuminated tubers. Total glycoalkaloids were not significantly impacted by light source. The use of fiber optic lighting or a combination of fiber optic lighting with standard fluorescent lighting would retard the progression of greening in the retail store yet potentially highlight the commodity for consumer eye-appeal.     

An Economic Analysis of the Effects of Harvest Timing on Yield,Quality, and Processing Contract Price for three Potato Varieties

Harvesting potatoes at or near physiological maturity increases the likelihood of producing high quality tubers which contributes to producing high quality processed end-product. Some growers harvest earlier than recommended in order to meet contract requirements and supply processors with early potatoes. Early harvest impacts the incentive-adjusted price (IAP) and revenue even after an early harvest incentive is applied. This study utilized a typical frozen processor contract and compared the economic impact of harvest timing (early, normal, and late) on the IAP of three potato varieties: Russet Burbank, Clearwater Russet, and Alpine Russet, grown in field trials at Parma, Idaho during 2014 and 2015. Contract quality incentives included percent of tubers greater than 170 g, percent sugar ends, percent of U.S. No. 1’s, and specific gravity. When compared to normal or late harvest, early harvest resulted in a decrease in the IAP and overall profit due to a significant reduction in specific gravity. Early harvest incentive did not offset the loss of revenue with Russet Burbank, but did offset revenue loss with Clearwater Russet and Alpine Russet. Clearwater Russet and Alpine Russet had significantly lower sugar end scores than Russet Burbank. Clearwater Russet consistently produced higher specific gravities and Alpine Russet produced larger tubers compared to Russet Burbank. Clearwater Russet and Alpine Russet have agronomic characteristics that can provide an increase in IAP over Russet Burbank.     

Anesthetic considerations of the older equine.

This article briefly reviews physiologic changes that may occur with aging in equine patients. It summarizes anesthetic protocols and problems encountered in a group of older horses (> 20 years old) anesthetized over the previous 10 years in the teaching hospital and makes recommendations for appropriate management of these patients.     

Sprout inhibition in storage: Current status, new chemistries and natural compounds

A major component of managing potato quality in storage is effective sprout inhibition. Sprouting causes increased weight loss, reduced tuber quality and impedes air movement through the potato pile. The primary method to control sprouting in storage is with postharvest applications of isopropylN-(3-chlorophenyl) carbamate (chlorpropham; CIPC). CIPC inhibits sprout development by interfering with cell division. However, a recent Environmental Protection Agency mandate, from the requirements of the Food Quality Protection Act (FQPA) of 1996, resulted in a reduction in allowable CIPC residue on fresh potatoes in the United States from 50 ppm to 30 ppm. This mandate coincides with tolerance reductions or restrictions for use of CIPC in other parts of the world. CIPC is an effective sprout inhibitor although factors such as storage conditions, application technology, and cultivar can impact that effectiveness. Alternative sprout inhibitors to CIPC continue to be evaluated. Essential oils (e.g., caraway, peppermint, spearmint, clove) or their components (e.g., s-carvone, eugenol), and hydrogen peroxide-based materials, physically damage the developing sprout and suppress sprout elongation. However, repeated or continuous application of these compounds may be necessary for efficacy. Substituted naphthalenes (e.g., dimethyl naphthalene, diisopropyl naphthalene) may help reduce the amount of CIPC applied and/or our dependency on CIPC for sprout suppression in storage. The objective of this review is to summarize the current use of CIPC for potato sprout inhibition in storage and to review the status of current research on other postharvest applied compounds or materials that may be used as alternatives for CIPC.     

Influence of the extracting solvent upon the structural properties of Amaranth (Amaranthus hypochondriacus) glutelin

Two amaranth glutelin preparations, Gt-bo extracted with borate buffer at pH 10 and Gt-na extracted with 0.1 N NaOH, were characterized and compared with the amaranth polymerized 11S globulin (Gp, globulin-P). Gt-bo and Gt-na presented very similar polypeptidic composition and a similar reactivity against an anti-Gp polyclonal antibody, although lower than that of Gp. It is demonstrated that Gt-na is composed of denatured and dissociated molecules, whereas Gt-bo consists of folded molecules. The size, polypeptidic composition, thermal stability, and denaturation enthalpy of Gt-bo molecules were similar to those of Gp subjected to a borate treatment at pH 10. The Gp immunoreactivity decreased to the level of Gt reactivity when subjected to alkaline treatment; this could be due to conformational changes. Results suggest that, like Gp, amaranth Gt molecules may be hexameric oligomers of approximately 300 kDa. They would be partially unfolded during the alkaline extraction.     

Dry gibberellic acid combined with talc or fir bark enhances early stem and tuber growth of Shepody potato

Gibberellic acid (GA₃) powder was applied to seed pieces of Shepody potato in combination with water, fir bark and talc carriers. In a greenhouse study, emergence, stem growth and tuber number from seed pieces treated with dry GA₃ and carriers were compared with that of an untreated control. All carriers alone reduced stem emergence. GA₃ (0.5,1 and 2 mg/ kg) combined with talc, and 0.5 and 2 mg GA₃/kg with fir bark+talc enhanced emergence. Only 2 mg GA₃/kg enhanced emergence when applied in solution. Emergence of stems from pieces treated with GA₃ and fir bark was no different or slower than the control. In the absence of GA₃, water and talc increased stem number and fir bark-containing treatments reduced tuber number. All concentrations of GA₃ applied with talc or fir bark+talc, and 2 mg GA₃/kg with fir bark increased stem and tuber number. With water, 0.5, 1 and 2 mg GA₃/kg increased stem number but only 2 mg GA₃/ kg resulted in more tubers. One and 2 mg GA₃/kg combined with talc resulted in the most stems and tubers 58 days after planting. GA₃ was as effective or more effective in speeding emergence and increasing stem and tuber number when applied in the dry form with talc or fir bark+talc as when applied in solution.     

Ecological niche partitioning between Anopheles gambiae molecular forms in Cameroon: the ecological side of speciation

Background  

Speciation among members of the Anopheles gambiae complex is thought to be promoted by disruptive selection and ecological divergence acting on sets of adaptation genes protected from recombination by polymorphic paracentric chromosomal inversions. However, shared chromosomal polymorphisms between the M and S molecular forms of An. gambiae and insufficient information about their relationship with ecological divergence challenge this view. We used Geographic Information Systems, Ecological Niche Factor Analysis, and Bayesian multilocus genetic clustering to explore the nature and extent of ecological and chromosomal differentiation of M and S across all the biogeographic domains of Cameroon in Central Africa, in order to understand the role of chromosomal arrangements in ecological specialisation within and among molecular forms.     

Living at the edge: biogeographic patterns of habitat segregation conform to speciation by niche expansion in Anopheles gambiae

Background

Ongoing lineage splitting within the African malaria mosquito Anopheles gambiae is compatible with ecological speciation, the evolution of reproductive isolation by divergent natural selection acting on two populations exploiting alternative resources. Divergence between two molecular forms (M and S) identified by fixed differences in rDNA, and characterized by marked, although incomplete, reproductive isolation is occurring in West and Central Africa. To elucidate the role that ecology and geography play in speciation, we carried out a countrywide analysis of An. gambiae M and S habitat requirements, and that of their chromosomal variants, across Burkina Faso.

Results

Maps of relative abundance by geostatistical interpolators produced a distinct pattern of distribution: the M-form dominated in the northernmost arid zones, the S-form in the more humid southern regions. Maps of habitat suitability, quantified by Ecological Niche Factor Analysis based on 15 eco-geographical variables revealed less contrast among forms. M was peculiar as it occurred proportionally more in habitat of marginal quality. Measures of ecological niche breadth and overlap confirmed the mismatch between the fundamental and realized patterns of habitat occupation: forms segregated more than expected from the extent of divergence of their environmental envelope – a signature of niche expansion. Classification of chromosomal arm 2R karyotypes by multilocus genetic clustering identified two clusters loosely corresponding to molecular forms, with 'mismatches' representing admixed individuals due to shared ancestral polymorphism and/or residual hybridization. In multivariate ordination space, these karyotypes plotted in habitat of more marginal quality compared to non-admixed, 'typical', karyotypes. The distribution of 'typical' karyotypes along the main eco-climatic gradient followed a consistent pattern within and between forms, indicating an adaptive role of inversions at this geographical scale.

Conclusion

Ecological segregation between M and S is consistent with niche expansion into marginal habitats by chromosomal inversion variants during early lineage divergence; presumably, this process is promoted by inter-karyotype competition in the higher-quality core habitat. We propose that the appearance of favourable allelic combinations in other regions of suppressed recombination (e.g. pericentromeric portions defining speciation islands in An. gambiae) fosters development of reproductive isolation to protect linkage between separate chromosomal regions.     

Herpes simplex virus encephalitis in human UNC-93B deficiency

Herpes simplex virus-1 (HSV-1) encephalitis (HSE) is the most common form of sporadic viral encephalitis in western countries. Its pathogenesis remains unclear, as it affects otherwise healthy patients and only a small minority of HSV-1-infected individuals. Here, we elucidate a genetic etiology for HSE in two children with autosomal recessive deficiency in the intracellular protein UNC-93B, resulting in impaired cellular interferon-alpha/beta and -lambda antiviral responses. HSE can result from a single-gene immunodeficiency that does not compromise immunity to most pathogens, unlike most known primary immunodeficiencies. Other severe infectious diseases may also reflect monogenic disorders of immunity.     

Tissue expression of ketohexokinase in cats

Ketohexokinase (KHK) metabolizes dietary fructose and is an important regulator of hepatic glucose metabolism. The veterinary literature contains conflicting data regarding the role of KHK in feline fructose metabolism. The study objectives were to determine tissue expression of KHK mRNA and protein in cats, with special emphasis on hepatic expression. KHK mRNA and protein expression were determined using routine RT-PCR and immunoblot techniques. KHK mRNA was detected in feline liver, pancreas, spleen and striated muscle but not in lung. The partial sequence of feline KHK mRNA obtained was highly similar to known KHK mRNA sequences. Immunoblot studies confirmed KHK protein expression in the feline liver. The tissue distribution of KHK mRNA in cats is similar to KHK expression in other species. KHK mRNA and protein expression in feline liver is consistent with previous reports of hepatic fructokinase activity in this species.