20,272 research outputs found
The cartographic application of ERTS/RBV imagery in polar regions
There are no author-identified significant results in this report
The cartographic application of ERTS/RBV imagery in polar regions
There are no author-identified significant results in this report
Association between body condition score and live weight in pasture-based Holstein-Friesian dairy cows
peer-reviewedThe objective was to quantify the strength of the relationship between body condition score (BCS) and live weight (LW) in pasture-based Holstein-Friesian dairy cattle, and to determine the kg LW per unit BCS. A total of 26021 test-day records with information on both BCS (1–10 scale, where 1 is emaciated and 10 is obese) and LW across 1110 lactations from one research farm were used in the analysis. Correlation and regression analyses were used to determine the degree of association between BCS and LW in different parities, stages of the inter-calving interval and years. Correlations between BCS and LW were relatively consistent, with the mean correlation between BCS and LW across all data of 0·55 implying that differences in BCS explain approximately 30% of the variation in LW. Significantly different regressions of LW on BCS were present within stage of inter-calving interval by parity subclasses. Excluding calving, LW per unit BCS varied from 17 kg (early to mid lactation in parity 1) to 36 kg (early lactation in parity 4 and 5). However, LW per unit BCS was greatest at calving varying from 44 kg in first parity animals to 62 kg in second parity animals. On average, 1 BCS unit equated to 31 kg LW across all data
The cartographic application of ERTS/RBV imagery in polar regions
The author has identified the following significant results. A 1.1,000,000 scale sketch map has been prepared from ERTS imagery of the Prince Olav Coast, Antarctica. This is the first such mapping of the extent of the ice tongues of the Shtrase and Fietta Bay glaciers. Shtrase is of particular interest because the ERTS imagery shows the tongue extending out into the Lutzom-Holm Bay approximately 32 miles further than ever depicted on existing maps. This sketch map and others in work covering coastal areas of the Antarctic continent show many coastal changes when compared to what is believed to be the most current published maps. These sketch maps along with the accompanying mosaics will be a bench mark for future revision to existing maps and charts and also an invaluable source for mew mapping. ERTS imagery is now available over Mt. Siple, Antarctica, and it is expected to provide a source to position Mt. Siple correctly in relation to the Executive Committee Range. A mosaic at 1:500,000 scale is also being compiled that will serve as a source for future revision of 1:250,000 scale maps of the Ellsworth Mountains, change and improve the shape and size of the islands within the Ronne Ice Shelf, and redefine the ice front of the Ronne and Filchner Shelves
A study of image quality for radar image processing
Methods developed for image quality metrics are reviewed with focus on basic interpretation or recognition elements including: tone or color; shape; pattern; size; shadow; texture; site; association or context; and resolution. Seven metrics are believed to show promise as a way of characterizing the quality of an image: (1) the dynamic range of intensities in the displayed image; (2) the system signal-to-noise ratio; (3) the system spatial bandwidth or bandpass; (4) the system resolution or acutance; (5) the normalized-mean-square-error as a measure of geometric fidelity; (6) the perceptual mean square error; and (7) the radar threshold quality factor. Selective levels of degradation are being applied to simulated synthetic radar images to test the validity of these metrics
The cartographic application of ERTS/RBV imagery in polar regions
The author has identified the following significant results. Preliminary analysis of the late 1973-74 Antarctic imagery, when compared to 1972-73 imagery and existing map sources, clearly shows changes in the ice fronts, glacier movement, and the existence of possible new geographical features
Responses to supplementation by dairy cows given low pasture allowances in different seasons 2. Milk production
Two factorial experiments were designed to determine the effects of stage of lactation, and season of the year, on cow responses to supplementary feeding. These experiments were conducted over consecutive years with 128 high genetic merit multiparous Holstein-Friesian cows in early, mid and late lactation in spring, summer, autumn and winter. At each stage of lactation, and in each season of the year, cows were offered a restricted pasture allowance (25 to 35 kg dry matter (DM) per cow per day), either unsupplemented (control) or with supplement at 50 MJ metabolizable energy (ME) per cow per day in experiment 1 and 80 MJ ME per cow per day in experiment 2. The two supplements given in both years were rolled maize grain (MG) and a mixture of foods formulated to nutritionally balance the diet (BR). In experiment 2, another treatment, of a generous pasture allowance (60 to 75 kg DM per cow per day) (AP), was imposed on an additional group of early lactation cows during each season. Direct milk solids (MS) (milk fat plus milk protein) responses in experiment 1 to MG were 169, 279, 195 and 251 g MS per cow per day in spring, summer, autumn and winter, respectively, while those to BR were 107, 250, 192, 289 g MS per cow per day. In experiment 2, however, milk solids responses to both supplements during spring were slightly below the control treatment, with values similar to those in experiment 1 in summer and autumn for cows on the BR but not the MG supplement. Milk solids responses to supplementary foods were largest during seasons of the year when the quantity and quality of pasture on offer resulted in the lowest milk solids yield from unsupplemented cows. When carry-over effects of feeding MG and BR on milk solids production were detected, they were only about half the magnitude of the direct effects. Serum urea concentrations were higher in control cows than those offered MG with a similar effect for BR in all but summer in experiment 1, while serum glucose concentrations were highest in winter and lowest in summer. The most important factor influencing milk solids responses was the relative food deficit (RFD) represented by the decline in milk solids yield of the respective control groups after,changing from a generous pasture allowance to restricted allowance when the feeding treatments were imposed. Total milk solids responses (direct and carry-over) to supplements were greatest when severe food restrictions, relative to the cows' current food demand, resulted in large reductions in milk solids yield of the control groups. The RFD was the best predictor of milk solids response to supplementary foods. Therefore, it is likely that cows are most responsive to supplementary foods during or immediately after the imposition of a severe food restriction
Responses to supplementation by dairy cows given low pasture allowances in different seasons 1. Pasture intake and substitution
Two factorial experiments were designed to determine the effects of stage of lactation, and season of the year, on cow responses to supplementary feeding. These experiments were conducted over consecutive years with 128 high genetic merit multiparous Holstein-Friesian cows in early, mid and late lactation in spring, summer, autumn and winter. At each stage of lactation, and in each season of the year, cows were offered a restricted pasture allowance (25 to 35 kg dry matter (DM) per cow per day), either unsupplemented (control) or supplemented with 50 MJ metabolizable energy (ME) per cow per day in experiment 1 and 80 MJ ME per cow per day in experiment 2. Two different supplements were offered, namely, rolled maize grain (MG) and a mixture of foods (BR) formulated to nutritionally balance the diet. In experiment 2, a fourth treatment consisting solely of a generous pasture allowance (60 to 75 kg DM per cow per day, AP) was introduced. Offering MG and BR increased DM intake (DMI). At the restricted pasture allowance, increasing total ME allowance (MEA) by offering supplementary foods increased ME intake (MEI) by 0.68 (s.e. 0.047) MJ per extra MJ ME offered. This highly significant (P < 0.001) linear relationship was consistent across seasons, and did not diminish at higher MEA. In experiment 2, cows in early lactation had lower substitution rates than mid and late lactation cows irrespective of season. Substitution rate was higher when higher pasture allowance or quality of pasture on offer enabled the unsupplemented cows to achieve higher DMI from pasture than at other times of the year. These results suggest that one of the key factors determining the intake response to supplementary foods is pasture allowance. Within spring calving dairying systems, the largest increases in total DMI per kg of supplement offered is likely when offering supplements to early lactation cows grazing restricted allowances of high quality pasture
Role of angiography following aneurysm surgery
Journal ArticleThe postoperative angiograms in 66 patients who underwent craniotomy for clipping of 78 cerebral aneurysms were reviewed. Indications for urgent postoperative angiography included neurological deficit or repeat subarachnoid hemorrhage. Routine postoperative angiograms were carried out in the remaining patients. Postoperative angiograms were reviewed to determine the incidence of unexpected findings such as unclipped aneurysms, residual aneurysms, and unforeseen major vessel occlusions. Logistic regression analysis was used to test if the following were factors that predicted an unexpected finding on postoperative angiography: aneurysm site or size; the intraoperative impression that residual aneurysm was left or a major vessel was occluded; intraoperative aneurysm rupture; opening or needle aspiration of the aneurysm after clipping; or development of a new neurological deficit after surgery. Kappa values were calculated to assess the agreement between some of these clinical factors and unexpected angiographic findings. Unexpected residual aneurysms were seen in three (4%) of the 78 occlusions. In addition, three aneurysms were completely unclipped (4%); these three patients were returned to the operating room and had their aneurysms successfully obliterated. There were nine unexpected major vessel occlusions (12%); six of these resulted in disabling stroke and two patients died. Of six major arteries considered to be occluded intraoperatively and shown to be occluded by postoperative angiography, two were associated with cerebral infarction. Logistic regression analysis showed that a new postoperative neurological deficit predicted an unforeseen vessel occlusion on postoperative angiography. Factors could not be identified that predicted unexpected residual aneurysm or unclipped aneurysm. The inability to predict accurately the presence of residual or unclipped aneurysm suggests that all patients should undergo postoperative angiography. Since a new postoperative neurological deficit is one factor predicting unexpected arterial occlusion, intraoperative angiography may be necessary to help reduce the incidence of stroke after aneurysm surgery. With study of more patients or of factors not examined in this series, it may be possible to select cases more accurately for intraoperative or postoperative angiography
J Fluorescence
The scope of this paper is to illustrate the need for an improved quality assurance in fluorometry. For this purpose, instrumental sources of error and their influences on the reliability and comparability of fluorescence data are highlighted for frequently used photoluminescence techniques ranging from conventional macro- and microfluorometry over fluorescence microscopy and flow cytometry to microarray technology as well as in vivo fluorescence imaging. Particularly, the need for and requirements on fluorescence standards for the characterization and performance validation of fluorescence instruments, to enhance the comparability of fluorescence data, and to enable quantitative fluorescence analysis are discussed. Special emphasis is dedicated to spectral fluorescence standards and fluorescence intensity standards
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