Comparison of periderm color and anthocyanins of four red potato varieties

The color, anthocyanin content per given surface area, and phenolics content of tuber periderm of four different varieties of red potatoes were compared. Three of the varieties, Norland, Red Norland, and Dark Red Norland, are members of a color sport family. Freshly harvested ‘Norland’ differed significantly in color, but not anthocyanin content per given surface area, from its sports. ‘Red Norland’ tubers were lighter in color than those of ‘Dark Red Norland’. In general, storage resulted in darkening of tubers and, except for the fourth variety, MN17922, a decrease in anthocyanin content per given surface area. Tubers from green-killed ‘Red Norland’ plants were more purplish-red than those from vine-killed plants. Stored tubers had greater periderm total phenolics content than freshly harvested tubers. The increase in periderm phenolics and decrease in anthocyanin content per given surface area may lead to darkening of tubers with storage. Cell walls connecting periderm to cortex tissue of ‘MN17922’ tubers were thinner than those in ‘Norland’ tubers, which may explain why it is realtively easy to separate the periderm of ‘MN17922’ from its cortex.     

Comparison of polyphenol oxidase in tubers ofSolanum tuberosum and the non-browning tubers ofS. hjertingii

Solarium hjertingii, a wild potato species, does not exhibit enzymatic browning nor blackspot. Blackspot and enzymatic browning are physiological disorders that are caused by the reaction of the enzyme polyphenol oxidase with phenolic substrates, resulting in discoloration of tuber cortex. We determined thatS. hjertingii has a low amount of at least one of the polyphenol oxidases in its tubers compared toS. tuberosum. Less than 5 μg ofS. tuberosum polyphenol oxidase protein, as determined from Western blot staining, had measurable enzymatic activity. In contrast,S. hjertingii protein with comparable staining had no detectable activity.     

Imaging features of disseminated xanthogranulomatous inflammation in eclectus parrots (Eclectus roratus)

Xanthogranulomatous disease is a rare condition, which can be caused by infection, inflammation, hemorrhage, immunologic disease, or inherited lysosomal disorders. It is characterized by non‐intracellular lipid and cholesterol deposits among an inflammatory infiltrate of vacuolated macrophages and giant cells. The diagnosis of xanthogranulomatous disease is challenging, with nonspecific imaging findings often misinterpreted as aggressive neoplastic processes in humans. In this retrospective case series study, we describe the diagnostic imaging characteristics of a disseminated xanthogranulomatous condition identified in five eclectus parrots (Eclectus roratus). Decreased serosal detail and celomic distension were present in all three birds radiographed, with multifocal variably sized celomic mineralization (3/3 birds), and extracelomic mineralized masses (1/3 birds). Celomic effusion with foci of celomic mineralization and hepatomegaly were identified in all birds (3/3) imaged with ultrasound. Finally, a mineralized mural ventricular mass was present in one of three patients imaged with CT, multifocal celomic mineralization with moderate to severe celomic effusion in two of three patients, diffuse severe proventricular and intestinal dilation in all three patients, and atherosclerosis of the major arterial trunks in all three patients. Veterinary radiologists should be aware of this inflammatory condition in birds, especially in eclectus parrots, and should be able to recognize the imaging features of xanthogranulomatous inflammation.     

HSPC117 is the essential subunit of a human tRNA splicing ligase complex

Splicing of mammalian precursor transfer RNA (tRNA) molecules involves two enzymatic steps. First, intron removal by the tRNA splicing endonuclease generates separate 5' and 3' exons. In animals, the second step predominantly entails direct exon ligation by an elusive RNA ligase. Using activity-guided purification of tRNA ligase from HeLa cell extracts, we identified HSPC117, a member of the UPF0027 (RtcB) family, as the essential subunit of a tRNA ligase complex. RNA interference-mediated depletion of HSPC117 inhibited maturation of intron-containing pre-tRNA both in vitro and in living cells. The high sequence conservation of HSPC117/RtcB proteins is suggestive of RNA ligase roles of this protein family in various organisms.     

Developing a landscape‐scale,multi‐species,and cost‐efficient conservation strategy for imperilled aquatic species in the Upper Tennessee River Basin,USA

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Nutrition management of cedar and hemlock plantations in coastal British Columbia

Recent re-measurements of silvicultural trials in conifer plantations on nutrient-poor cedar-hemlock (CH) cutovers on northern Vancouver Island have confirmed co-limitation by nitrogen and phosphorus. Repeated fertilization increased volumes of both cedar and hemlock on CH sites (at 2,500 stems ha^?1) by about 100 m³ ha^?1 relative to unfertilized plots 22 years following initial fertilization, and increased the productivity of regenerating conifers to a level approximating that of neighbouring hemlock-amabilis fir (HA) sites. More surprising was the response to fertilization on the more-productive HA sites. After 22 years, cedar in fertilized HA plots had produced an extra 180 m³ ha^?1 compared to unfertilized HA plots, while hemlock had produced an extra 250 m³ ha^?1 in fertilized plots (at 2,500 stems ha^?1). Thus, contrary to expectations, the greatest volume responses of both hemlock and cedar to fertilization occurred on the good (HA) sites rather than on the poor (CH) sites. Ecological studies of CH and HA sites supported the hypothesis that the poor nutrient supply and productivity of CH sites is a long-term consequence of excessive moisture, and that the two site types bracket a critical ecological threshold of moisture, aeration and redox.