The field study investigated the relationship of Minolta SPAD 502 (SPAD) readings to applied nitrogen (N) fertilizer rate, corn (Zea mays L.) yield, and leaf N concentration. The experiment was ...conducted on a total of six sites in Illinois during 1991 and 1992. Ten different open pedigree corn hybrids were grown at a final population of 65,000 plants ha-1. Nitrogen was applied at four rates (0, 90, 180, and 270 kg N ha-1) as 28% liquid N solution. Significant main effects of environment (E), and hybrid (H), and E x H interaction were detected for all measured parameters. SPAD readings and leaf N concentration at all sampling times (V7, R1, and R4) as well as grain N concentration were affected by N fertilizer rate. Maximum mean grain yield and maximum grain N concentration were obtained at 110 and 195 kg N ha-1, respectively. At all sampling times the correlation of SPAD readings to N fertilizer rate were low but significant (R=0.22 at V7 and R1, R=0.11 at R4). SPAD correlation to corresponding leaf N concentration improved over time. The Pearson correlation was R=0.33 at V7 and increased to R=0.78 at R4. The SPAD meter did a good job at providing a measure of the relative greenness of living leaves at a specific point in time. Chlorophyll readings can therefore be useful in detecting N deficiencies in growing crops. But, the SPAD meter cannot be used to make accurate predictions of how much fertilizer N will be needed by a crop during the future growing season. We conclude then that the SPAD meter will be most useful as a diagnostic aid rather than a tool for N management in corn
Rejection of genetically modified organisms (GMOs) by some consumers worldwide has led to the creation of market signals encouraging the segregation and identity preservation (IP) of non-genetically ...modified grain from genetically modified (GM) grain. This article examines the costs of non-GMO segregation and IP for seed producers, farmers and grain handlers in the United States. We find that a small fraction of farmers’ total costs of segregation and IP actually come from the steps farmers take to clean planting and harvesting equipment. Costs appear to come mainly from the production process itself (i.e. from foregoing planting of cost-reducing GM varieties). We argue that a major cost for handlers comes from a flexibility loss due to the necessity of dedicating equipment to one of two handling channels (one for GMOs and one for non-GMOs). For maize, an additional major cost comes from the necessity of preventing pollination of non-GM varieties by GM pollen at the seed and farm production stages. Tolerance levels are a key element of costs of segregation, and zero-tolerance levels may be impossible to obtain without major organisational and economic costs.
Mucormycosis is a highly aggressive fungal infection affecting diabetic, immunocompromised, and, occasionally, healthy patients. This infection is associated with significant mortality. We have ...reviewed 208 cases in the literature since 1970, 139 of which were presented in sufficient detail to assess prognostic factors, and added data from six of our patients. The histories of these 145 patients were analyzed for the following variables: 1) underlying conditions associated with mucormycotic infections; 2) incidence of ocular and orbital signs and symptoms; 3) incidence of nonocular signs and symptoms; 4) interval from symptom onset to treatment; and 5) the pattern of sinus involvement seen on imaging studies and noted at the time of surgery. Factors related to a lower survival rate include: 1) delayed diagnosis and treatment; 2) hemiparesis or hemiplegia; 3) bilateral sinus involvement; 4) leukemia; 5) renal disease; and 6) treatment with deferoxamine. The association of facial necrosis with a poor prognosis fell just short of statistical significance, but appears clinically important. This is the first review that documents the heretofore intuitive claim that early diagnosis is necessary to cure this disease. Standard treatment with amphotericin B and aggressive surgery are reviewed and adjunctive therapeutic modalities are discussed, including local amphotericin B irrigation, hyperbaric oxygen, and optimizing the immunosuppressive regimen in transplant patients. Hyperbaric oxygen was found to have a favorable effect on prognosis. In addition, possible treatment options for patients with declining renal function are reviewed.
Analysis and quantitative characterization of the spatial variability of soybean Glycine max (L.) Merr. protein and oil concentrations is an important task for site‐specific soybean management. The ...objectives of this study were to spatially characterize the variability of soybean protein and oil concentrations in five fields of central Illinois, and to determine the influence of field topographical features, such as elevation range, terrain slope, and terrain curvature, on soybean protein and oil concentrations and their distributions within the studied fields. More than 200 samples for soybean quality analysis were collected from each of the three studied fields in fall of 1998, and from each of the two fields in fall of 1999. Dense elevation measurements were taken on each of the fields and topographical features, such as slope and curvature, were derived from the elevation data using the geographic information system (GIS). Both protein and oil concentrations were spatially correlated in all the studied fields as indicated by variograms. Field topography strongly affected soybean quality; however, its influence depended on the weather conditions during the growing seasons. Higher protein was observed at higher elevation sites, as well as at sites with higher slopes and convex curvatures during growing seasons with sufficient or excessive precipitation, while lower proteins were observed at such topographical conditions when the growing season was dry. Ranges of spatial cross‐correlation between protein concentrations and elevation were related to the ranges and changes in shape of the elevation variograms, suggesting that spatial variability of field elevation can be used as an indicator of the spatial distribution of high protein or oil soybeans.
Lack of information about the spatial variability of soil C in different management systems limits accurate extrapolation of C sequestration findings to large scales. The objectives of this study ...were to: (i) describe and quantify variability of total C in three management systems, chisel‐plow (CT) and no‐till (NT) with conventional chemical inputs and a chisel‐plow organic management practice with cover crops (CT‐cover) 15 yr after conversion from conventional management; (ii) assess the strengths of spatial correlation in the three studied systems; and (iii) evaluate contributions of topography and texture to the overall total C variability and its spatial components. The data were collected at 12 60 by 60 m plots at the Long Term Ecological Research site, Kellogg Biological Station, MI. The data consisted of elevation measurements taken on a 2 by 5 m grid and a total of 1160 measurements of total C, sand, silt, and clay contents taken from the 0‐ to 5‐cm depth. Overall variability of total C in NT was more than four times greater than in CT, and in CT‐cover the variability was more than two times greater than CT. Spatial correlation of total C was the strongest in NT, followed by CT‐cover, and then by CT. Stronger spatial structures in NT and CT‐cover were found to form in response to topographical and texture gradients. Effects of texture were largely associated with topographical effects; however, even when topography was controlled for, texture still substantially contributed to explaining total C variability.
Hypertriglyceridemia is an independent risk factor for cardiovascular disease. Dietary interventions based on protein restriction (PR) reduce circulating triglycerides (TGs), but underlying ...mechanisms and clinical relevance remain unclear. Here, we show that 1 week of a protein-free diet without enforced calorie restriction significantly lowered circulating TGs in both lean and diet-induced obese mice. Mechanistically, the TG-lowering effect of PR was due, in part, to changes in very low-density lipoprotein (VLDL) metabolism both in liver and peripheral tissues. In the periphery, PR stimulated VLDL-TG consumption by increasing VLDL-bound APOA5 expression and promoting VLDL-TG hydrolysis and clearance from circulation. The PR-mediated increase in Apoa5 expression was controlled by the transcription factor CREBH, which coordinately regulated hepatic expression of fatty acid oxidation-related genes, including Fgf21 and Ppara. The CREBH-APOA5 axis activation upon PR was intact in mice lacking the GCN2-dependent amino acid-sensing arm of the integrated stress response. However, constitutive hepatic activation of the amino acid-responsive kinase mTORC1 compromised CREBH activation, leading to blunted APOA5 expression and PR-recalcitrant hypertriglyceridemia. PR also contributed to hypotriglyceridemia by reducing the rate of VLDL-TG secretion, independently of activation of the CREBH-APOA5 axis. Finally, a randomized controlled clinical trial revealed that 4-6 weeks of reduced protein intake (7%-9% of calories) decreased VLDL particle number, increased VLDL-bound APOA5 expression, and lowered plasma TGs, consistent with mechanistic conservation of PR-mediated hypotriglyceridemia in humans with translational potential as a nutraceutical intervention for dyslipidemia.
The choice of an optimal interpolation technique for estimating soil properties at unsampled locations is an important issue in site‐specific management. The objective of this study was to evaluate ...inverse distance (InvD) weighting, ordinary kriging (KO), and lognormal ordinary kriging (KOlog) to determine the optimal interpolation method for mapping soil properties. Relationships between statistical properties of the data and performance of the methods were analyzed using soil test P and K data from 30 agricultural fields. For InvD weighting, we used powers of 1, 2, 3, and 4. The numbers of the closest neighboring points ranged from 5 to 30 for the three methods. The results suggest that KOlog can improve estimation precision compared with KO for lognormally distributed data. The criteria helpful in deciding whether KOlog is applicable for the given data set were the Kolmogorov‐Smirnov goodness‐of‐fit statistic, coefficient of variation, skewness, kurtosis, and the size of the data set. Careful choice of the exponent value for InvD weighting and of the number of the closest neighbors for both InvD weighting and kriging (KO or KOlog) significantly improved the estimation accuracy (P≤ 0.05). However, no a priori decision could be made about the optimal exponent and the number of the closest neighbors based on the statistical properties of the data. For the majority of the data sets, kriging with the optimal number of the neighboring points, a carefully selected variogram model, and appropriate log‐transformation of the data performed better than InvD weighting. Correlation coefficients between experimental data and estimated results of kriging were higher than those of InvD for 57 out of a total of 60 data sets, kriging mean absolute errors were lower for 44 data sets, and kriging mean errors were lower than those of InvD weighting for 31 data sets.
In 2018, a new practice-based small group learning (PBSGL) pilot initiative was launched in Wales to promote interprofessional learning among different primary care professionals. The aim of this ...study was to evaluate the initiative in order to identify its strengths and areas for improvement. Data were collected through focus groups with PBSGL groups in Wales and analysed thematically. Participants generally held positive views of PBSGL and were impressed with the variety and overall relevance of the learning materials, although concern was raised about the relevance of all learning materials to the Welsh context. The interprofessional component was valued for reducing feelings of isolation and all participants were able to contribute to discussions, an outcome helped by existing relationships among group members. Many participants reflected on occasions where they had made changes to their practice as a result of PBSGL activity. Time and funding were cited as potential barriers to continuing participation in PBSGL and there is scope to tailor material more to the context of the healthcare system in Wales.
Nerve growth factor causes mediator release from rat peritoneal mass cells in the presence of lysophosphatidylserine. We have
investigated the neurotrophin and receptor specificity involved in this ...response. Nerve growth factor produced a dose-dependent
release of 14Cserotonin in the presence of lysophosphatidylserine with an EC50 of approximately 1 nM. Incubation with brain-derived
neurotrophic factor and neurotrophin-3 did not produce a response. Northern blot analysis with probes for low affinity nerve
growth factor receptor (p75), trkA, trkB, and trkC demonstrated a detectable signal for trkA only. Western blots of trkA immunoprecipitates
from mast cell culture lysates, probed with anti-phosphotyrosine antibodies, demonstrated expression of functional TrkA protein.
To determine whether p75, trkB, or trkC mRNA was present in amounts below the limit of detection for Northern analysis, a
sensitive reverse transcriptase polymerase chain reaction protocol was used; again rat peritoneal mast cells demonstrated
only trkA. The predominant form of trkA message expressed in rat peritoneal mast cells was smaller than the neuronal form.
An 18-nucleotide exon (coding for 6 amino acids in the extracellular domain) in the neuronal message was not found in the
predominant mast cell trkA message. PC12 cells, a rat pheochromocytoma cell line, and dissociated rat sympathetic neurons
showed both trkA and p75, but not trkB or trkC. Anterior pituitary expressed both trkB and trkC, but not trkA. To confirm
the lack of expression of p75 on mast cells, 125I-nerve growth factor was chemically cross-linked to mast cells or PC12 cells
and then immunoprecipitated with a monoclonal antibody specific for p75, 192-IgG; no p75 was detected. Thus, mediator release
from rat peritoneal mast cells by nerve growth factor was specific and not a general property of neurotrophins, and the response
was modulated through the trkA proto-oncogene. To our knowledge, this is the first description of a bone marrow-derived cell
type that expresses trkA at both the mRNA and protein levels. These data provide further evidence that p75 is not necessary
for nerve growth factor signal transduction.
The Chlamydia trachomatis type three-secreted effector protein CT694 is expressed during late-cycle development yet is secreted by infectious particles during the invasion process. We have previously ...described the presence of at least two functional domains within CT694. CT694 was found to interact with the human protein Ahnak through a C-terminal domain and affect formation of host-cell actin stress fibers. Immunolocalization analyses of ectopically expressed pEGFP-CT694 also revealed plasma membrane localization for CT694 that was independent of Ahnak binding. Here we provide evidence that CT694 contains multiple functional domains. Plasma membrane localization and CT694-induced alterations in host cell morphology are dependent on an N-terminal domain. We demonstrate that membrane association of CT694 is dependent on a domain resembling a membrane localization domain (MLD) found in anti-host proteins from Yersinia, Pseudomonas, and Salmonella spp. This domain is necessary and sufficient for localization and morphology changes but is not required for Ahnak binding. Further, the CT694 MLD is able to complement ExoS ΔMLD when ectopically expressed. Taken together, our data indicate that CT694 is a multidomain protein with the potential to modulate multiple host cell processes.
Background: The Chlamydia trachomatis secreted effector CT694 is deployed during invasion and exerts multiple effects on host cells.
Results: Residues 40–80 of CT694 contain a domain necessary and sufficient for peripheral localization to eukaryotic membranes.
Conclusion: CT694 employs membrane association to manifest effects on host cells.
Significance: Elucidating functional protein domains is essential to understand molecular mechanisms of infection employed by the pathogen C. trachomatis.
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