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81.
Improving our knowledge of pre-anthropogenic landscapes is vital for understanding landscape-scale heterogeneity and for setting goals and objectives for ecological restoration. This is especially important in highly modified landscapes that contain few remnants of pre-impact ecosystems. This study aims to develop new methodology to improve understanding of historical vegetation, using the now-degraded inhabited highlands of the Galapagos Islands as a case study. Our multidisciplinary approach innovatively combines data from interviews with residents who were familiar with the vegetation before most degradation occurred with the more traditional sources of historical aerial photography and information from early explorer and scientist reports. We reconstruct historical vegetation across the landscape by mapping it in the year 1960 and discussing this map in the historical context of anthropogenic change. Our results confirm published vegetation types but also define some other types not previously described, and suggest much greater spatial, temporal and structural heterogeneity than commonly understood. This result can be used by Galapagos land managers to better match species assemblages with sites and plan restoration actions that will maximise resilience against the ongoing and future threats of climate change and species invasions. Our methodology can be applied in extensive areas of the world where the majority of anthropogenic disturbance to natural ecosystems has been within the past 60 years. 相似文献
82.
William W. Kirk Kimberly J. Felcher David S. Douches Brendan A. Niemira Raymond Hammerschmidt 《American Journal of Potato Research》2001,78(4):319-322
Late blight is an important disease of potato(Solanum tuberosum L.) worldwide, and therefore, many potato-breeding programs have prioritized the development of late blight-resistant potato cultivars. Although the emphasis has been to enhance foliar resistance, it is also necessary to evaluate tuber late blight resistance in new breeding lines and new sources of late blight resistance. We report here on the assessment of foliar and tuber resistance and the correlation between these aspects of resistance in a sample of Michigan State University potato breeding lines. Two MSU breeding lines had significantly less infected foliage than the susceptible check cultivars. Tuber susceptibility was significantly different (P < 0.05) only between the most susceptible and the least susceptible breeding lines/cultivars. Foliar and tuber susceptibility to potato late blight were not correlated as low tuber susceptibility was associated both with extremely low (e.g., MSG274-3) and high (e.g., MSE202-3Rus) foliar susceptibility. 相似文献
83.
Bommarito DA Lattimer JC Selting KA Henry CJ Cohen M Johnson GC 《Journal of the American Animal Hospital Association》2011,47(6):e188-e194
A 12 yr old castrated male Yorkshire terrier was presented with a history of an inoperable pheochromocytoma. Physical examination revealed a large, midabdominal mass. Neurologic examination was normal at presentation. An abdominal computed tomography scan revealed a 215 cm(3) mass in the region of the right kidney. Forty-eight hours after IV injection of 370 megabecquerels (MBq, equivalent to10 millicuries [mCi]) of metaiodobenzylguanidine labeled with radioactive iodine ([(131)I]MIBG), standard planar scintigraphy was performed. A diffuse area of moderate uptake was noted in the midabdominal region. The dog experienced stable disease for 1.5 mo after injection based on a follow-up computed tomography (CT) scan; however, 5 mo after injection, repeat CT imaging revealed progression of the tumor, and a second IV injection of 370 MBq (10 mCi) of [(131)I]MIBG was administered. The dog died 3 wk after the second injection as a result of gastrointestinal blood loss that was believed to be caused by compression-induced bowel ischemia by the mass. A full necropsy was not performed, but the mass was removed for histologic evaluation, which confirmed the diagnosis of pheochromocytoma. This report is the first to document the treatment of canine pheochromocytoma using [(131)I]MIBG. 相似文献
84.
85.
Magolski JD Luther JS Neville TL Redmer DA Reynolds LP Caton JS Vonnahme KA 《Journal of animal science》2011,89(11):3819-3823
The effects of maternal nutrition on offspring wool production (quality and quantity) were evaluated. Primiparous Rambouillet ewes (n = 84) were randomly allocated to 1 of 6 treatments in a 2 × 3 factorial design. Selenium treatment [adequate Se (ASe, 9.5 μg/kg of BW) vs. high Se (HSe, 81.8 μg/kg of BW)] was initiated at breeding, and maternal nutritional intake [control (CON, 100% of requirements) vs. restricted (60% of CON) vs. overfed (140% of CON)] was initiated at d 50 of gestation. Lamb birth weight was recorded at delivery, and all lambs were placed on the same diet immediately after birth to determine the effects of prenatal nutrition on postnatal wool production and follicle development. At 180 ± 2.2 d of age, lambs were necropsied and pelt weights were recorded. Wool samples were collected from the side and britch areas, whereas skin samples were collected from the side of each lamb only. Although Se status did not influence side staple length in males, female lambs born from ewes on the ASe treatment had a shorter staple length (P < 0.05) when compared with females from ewes on the HSe treatment. Maternal nutritional intake and Se status did not influence (P ≥ 0.23) wool characteristics on the britch. However, at the britch, wool from female lambs had a reduced comfort factor (P = 0.01) and a greater (P = 0.02) fiber diameter compared with wool from male lambs. Maternal Se supplementation, maternal nutritional plane, sex of the offspring, or their interactions had no effect (P > 0.13) on primary (29.10 ± 1.40/100 μm(2)) and secondary (529.84 ± 21.57/100 μm(2)) wool follicle numbers. Lambs from ASe ewes had a greater (P = 0.03) secondary:primary wool follicle ratio compared with lambs from HSe ewes (20.93 vs. 18.01 ± 1.00). Despite similar postnatal diets, wool quality was affected by maternal Se status and the maternal nutritional plane. 相似文献
86.
Hammer CJ Thorson JF Meyer AM Redmer DA Luther JS Neville TL Reed JJ Reynolds LP Caton JS Vonnahme KA 《Journal of animal science》2011,89(11):3690-3698
To investigate the influence of maternal Se supply and plane of nutrition on lamb morbidity, mortality, and passive transfer of IgG, pregnant ewe lambs were used in 2 experiments with 2 × 3 factorial treatment arrangements. Supplementation of Se began at breeding and was either adequate Se (ASe, 9.5 μg/kg of BW) or high Se (HSe, 81.8 μg/kg of BW) in Exp. 1 or ASe (11.5 μg/kg of BW) or HSe (77.0 μg/kg of BW) in Exp. 2. On d 50 or 40 of gestation for Exp. 1 or 2, respectively, ewes were assigned randomly to 1 of 3 nutritional planes: 60% (RES), 100% (control, CON), or 140% (HI) of NRC requirements. This resulted in the following treatments: ASe-RES, ASe-CON, ASe-HI, HSe-RES, HSe-CON, and HSe-HI. Upon parturition, lambs were separated from their dams and serum samples obtained. Lambs were fed artificial colostrum for the first 20 h and then placed on milk replacer and grain pellets until completion of the study (Exp. 1, 57 d; Exp. 2, 21 d). Twenty-four hours after parturition, lamb serum samples were collected for IgG analysis. All lambs were reared similarly and morbidity and mortality assessed. Main effects were considered significant when P ≤ 0.05. In Exp. 1, there was a Se × plane of nutrition interaction (P ≤ 0.01) for lamb morbidity from birth to weaning and for 24-h IgG concentration. Lambs from ASe-RES and HSe-HI ewes were treated more frequently (P < 0.01) for respiratory and gastrointestinal disease, and lambs from HSe-HI ewes had the smallest (P < 0.01) 24-h serum IgG concentration. In Exp. 1, lambs from HI ewes also had the greatest (P < 0.01) mortality rates from birth to weaning compared with lambs from CON and RES ewes. In Exp. 2, there was an effect (P < 0.01) of maternal plane of nutrition with lambs from RES ewes having increased 24-h IgG compared with lambs from CON and HI ewes. There was no effect of maternal Se supplementation on lamb 24-h IgG in Exp. 2; however, there was a Se × plane of nutrition interaction (P < 0.01) for morbidity. From birth to 21 d of age, lambs from ASe-CON ewes had fewer (P < 0.01) treatment days compared with lambs from any of the other treatment groups. There also tended (P = 0.08) to be an effect of maternal Se supplementation on lamb mortality with increased mortality observed in lambs from HSe ewes. Results from the studies show a restricted maternal plane of nutrition can increase lamb serum IgG concentration. Selenium results were not consistent between the 2 experiments and may be due to differences in maternal Se. 相似文献
87.
88.
Christopher J. Catanzaro Kimberly A. Williams Roger J. Sauve 《Journal of plant nutrition》2013,36(5):1025-1036
In two experiments, ‘Charm’ and ‘Delano’ chrysanthemum [Dendranthema x grandiflorum (Ramat.) Kitamura] were grown in a peat‐based root medium using standard greenhouse cultural practices. Fertilization treatments included (1) alternate liquid fertilization (ALF): water‐soluble formulation of 15N‐4.3P‐24.9K (15–10–30) at 536 mgL‐1 N alternated with tap water irrigation; (2) Constant Liquid Fertilization (CLF): 15N‐4.3P‐24.9K(15–10–30)at268 mgL‐1 Napplied at each irrigation; (3) slow release resin‐coated fertilizer (SRR): slow release formulation of 12N‐4.3P‐14.1K(12–10–17); and (4) slow release tablets (SRT): slow release formulation of 14N‐1.7P‐4.9K (14–4–6). Irrigation volume and timing of application were arbitrary for all plants in the first experiment, but they were determined gravimetrically for each treatment in the second experiment. Irrigation volumes exceeded container capacity by 20 to 30% (leaching fractions of 0.2 to 0.3). Leachate had lower electrical conductivity and higher pH with the slow release products than with liquid fertilizer. All treatments except SRT produced plants which met commercial crop standards and had adequate nutrient levels in shoot tissue. However, root dry mass was higher with slow release fertilizer than with liquid fertilizer. Rootrshoot ratios were ranked SRT>SRR>ALF=CLF. Root data suggest that an advantage of SR fertilization over LF fertilization is that greater root mass will develop. Estimations of nitrogen (N) recovery in Experiment 2 suggest that chrysanthemums grown with SRR resulted in most efficient uptake of fertilizer with 64 to 68% of applied N recovered in plant tissue (compared to 41 to 46% from LF treatments) and 18 to 21 % recovered in container leachate (compared to 32 to 41% from LF treatments). 相似文献
89.
Kimberly Klock-Moore 《Compost science & utilization》2013,21(1):58-62
Growth of Impatiens wallerana Hook. ‘Accent Orange’ was compared in two compost products made of biosolids and yard trimmings but differing in final particle size. The first product was screened to pass a 19 mm screen while the second product was screened to pass a 13 mm screen. Treatments consisted of 100 percent compost or substrates in which compost was combined with control substrate components at 60 percent, 30 percent, or zero percent compost. Shoot dry mass and size increased linearly as the percentage of each compost product in the growing substrate increased from zero to 100 percent. Final substrate electrical conductivity (EC), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) concentrations also linearly increased as the percentage of each compost product increased in the substrate. Final plant size and shoot dry mass were significantly greater in the 13-mm product than in the 19-mm product. However, both the 13-mm and 19-mm products at 100 percent produced larger impatiens ‘Accent Orange’ plants compared with plants grown in zero percent compost. 相似文献
90.
Contrasting patterns of variation in weedy traits and unique crop features in divergent populations of US weedy rice (Oryza sativa sp.) in Arkansas and California
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