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21.
The distribution of selected elements in individual fractions of organic matter from anthropogenically contaminated soils was investigated. The attention was paid especially at Hg. Furthermore, contents of S, Mg, Mn, Fe, Cu, Zn and Pb were also measured. The decomposition of organic matter to particular fractions was carried out by the resin DAX-8. Ten soil samples were collected, and the Advanced Mercury Analyzer (AMA-254) was used for the determination of the total Hg content. The two highest Hg values reached up to the concentration 10.5 mg kg?1, and in the highest one, it was almost 29 mg kg?1. In each extract, mercury was measured by inductively coupled plasma mass spectrometry (ICP-MS), for other elements, inductively coupled plasma optical emission spectrometry (ICP-OES) was applied. Results of the analysis show that the Hg content bound to the humic acids is inversely proportional to the content of Mg, Mn, Fe and Cu. However, this dependence was not confirmed by the samples with the mercury content above 10 mg kg?1. In the case of fulvic acids, the relationship between Hg and S was observed and has again an inverse character.  相似文献   
22.
The cases of 7 adult dogs with generalized seizures managed by surgical excision and radiation therapy for frontal lobe meningiomas were reviewed. The neurological examination was unremarkable in 6 of the 7 dogs. Five dogs were operated on using a bilateral transfrontal sinus approach and 2 using a unilateral sinotemporal approach to the frontal lobe. One dog was euthanized 14 d after surgery; radiation therapy was initiated 3 wk after surgery in the remaining 6 dogs. Long-term follow-up consisted of neurological examination and magnetic resonance imaging (MRI) and/or computed tomography (CT) scan after radiation therapy. The mean survival time for dogs that had surgery and radiation therapy was 18 mo after surgery. Frontal lobe meningiomas have been associated with poor prognosis. However, the surgical approaches used in these cases, combined with radiation therapy, allow a survival rate for frontal lobe meningiomas similar to that for meningiomas located over the cerebral convexities.  相似文献   
23.
Plant canopy optimization models predict that leaf nitrogen (N) distribution in the canopy will parallel the vertical light gradient, and numerous studies with many species have confirmed this prediction. Further, it is predicted that for a given canopy leaf area, a low vertical light extinction coefficient will promote rapid growth. Therefore, the ideal canopy of fast-growing plants should combine high leaf area index with a low light extinction coefficient; the latter being reflected in a flat vertical leaf N gradient throughout the canopy. Based on data from an experimental Salix stand (six varieties) grown on agricultural land in central Sweden, we tested the hypothesis that shoot growth is correlated with vertical leaf N gradient in canopies of hybrid willows bred for biomass production, which could have implications for Salix breeding. Tree improvement research requires screening of growth-related traits in large numbers of plants, but assessment of canopy leaf N gradients by chemical analysis is expensive, time-consuming and destructive. An alternative to analytical methods is to estimate leaf N gradients nondestructively with an optical chlorophyll meter (SPAD method). Here we provide a specific calibration for interpreting SPAD data measured in hybrid willows grown in biomass plantations on fertile agricultural land. Based on SPAD measurements, a significant and inverse relationship (r(2) = 0.88) was found between shoot biomass growth and vertical leaf N gradient across canopies of six Salix varieties.  相似文献   
24.
The objective of this study was to quantify and compare the effects of sow's milk and 2 milk replacer diets (containing clotting or non-clotting protein sources) on exocrine pancreatic secretion, plasma cholecystokinin, and immunoreactive cationic trypsin in pigs. In addition, the relationship between exocrine pancreatic secretion and growth in milk-fed pigs was studied. In a changeover experiment, 9 chronically catheterized pigs of 6.6 +/- 0.19 kg of BW were studied for 3 wk. Pigs were assigned to each of 3 diets. Exocrine pancreatic secretion was measured from the third to the seventh day on each diet. The protein content and trypsin activity of the pancreatic juice were measured. Blood samples were taken at 10 min before and after milk ingestion and were analyzed for cholecystokinin and immunoreactive cationic trypsin. Pancreatic protein and trypsin secretion did not differ between pigs fed sow's milk and those fed milk replacer, but the volume secreted was less for the pigs fed sow's milk (0.75 vs. 1.03 mL x kg(-1) x h(-1); P < 0.01). A postprandial response to milk intake was not observed. The 2 milk replacer diets did not affect exocrine pancreatic secretion differently. The average exocrine pancreatic secretion (volume, 0.94 mL x kg(-1) x h(-1); protein, 4.28 mg x kg(-1) x h(-1); trypsin, 1.65 U x kg(-1) x h(-1)) was intermediate between literature values for suckling and weaned pigs. Plasma cholecystokinin was elevated (approximately 18 pmol x L(-1)) and showed low correlations with the pancreatic secretion traits. Plasma immunoreactive cationic trypsin was not significantly related to any of the pancreatic secretion traits and should therefore not be used as an indicator for exocrine pancreatic function in milk-fed pigs. Exocrine pancreatic secretion varied substantially among individual pigs (protein, 0.22 to 13.98 mg x kg(-1) x h(-1)). Pancreatic protein and trypsin secretion showed a positive, nonlinear relationship with performance traits. It was concluded that neither specific sow's milk ingredients nor the protein source are responsible for a low pancreatic protein secretion in suckling pigs. Exocrine pancreatic secretion was positively correlated with ADG in pigs at an identical milk intake.  相似文献   
25.
Panosteitis, an idiopathic bone disease of young dogs, was investigated in the light of a new, empirically based hypothesis governing its pathogenesis. Extensive clinical observations suggest a close relationship between the incidence of this disease and the commercialization of various protein-rich, high-calorie dog foods. The theory of an "osseous compartment syndrome" provides a hypothetical pathogenesis, which corroborates this findings. An excessive accumulation of protein causes intraosseous edema due to its osmotic effects. Because bone is a rigid compartment, this leads to an increase in intramedullary pressure and compression of blood vessels. Subsequent osseous ischemia leads to a deficient metabolic state (decreased oxygenation, inadequate influx of nutritive substances, local acidosis, decreased removal of metabolites, disruption of local biochemical processes, etc.), and a vicious circle is created due to the resulting local inflammation. The disease is aggravated by increased metabolism due to excessive physical activity. Within the context of a pilot study, clinical, radiographic, scintigraphic and thermographic examinations and a therapeutic trial with benzopyron were carried out. In addition, more modern investigative tools, including osteomyelography, magnetic resonance tomography and intraosseous pressure measurements were used to provide objective data concerning the pathogenesis of panosteitis. In most cases, clinical remission was seen within days of monotherapy with the proteolytic substance, benzopyron (Cumartrin). This finding appears to corroborate our hypothesis.  相似文献   
26.
Bluetongue (BT) virus serotype 2 (BTV 2) was first confirmed in Tunisia in February 2000 and has since spread northward and westward, infecting several other countries and islands, including Corsica, where clinical disease was reported in October 2000. BT was again reported on the Island in July 2001, some six months after a vaccination campaign against BTV 2. The molecular relationship between isolates of the BTV 2 Corsican wild-type viruses from 2000 and 2001, and the attenuated BTV 2 vaccine were determined by comparing corresponding sequences of genome segments 2, 7 and 10 with each other and with already published sequences available in the genome database. Complete genetic stability was observed between the isolates of the Corsican BTV 2. There was some divergence between the nucleotide sequences of segment 10 obtained from the wild-type and vaccine virus strains. Based on these differences, primers were selected that could be used in RT-PCR to differentiate between the wild-type and the vaccine viruses.  相似文献   
27.
Triticale is the intergeneric hybrid between wheat and rye. With the expansion of the triticale growing area, powdery mildew has emerged and become a significant disease on this new host. Recent research demonstrated that this ‘new’ powdery mildew on triticale has emerged through a host range expansion of powdery mildew of wheat. Moreover, isolates sampled from triticale still infect their previous host, wheat, but isolates sampled from wheat hardly infect triticale. Race‐specific and adult‐plant resistance have been identified in triticale cultivars. The main objective of this study was to characterize the cellular basis of powdery mildew resistance in triticale. Commonalities with resistance responses in other cereals such as wheat, barley and oat are discussed. A detailed comparative histological study of various resistance responses during cross‐inoculation of either virulent or avirulent wheat and triticale isolates on both hosts was carried out. The present data provide evidence that for incompatible interactions, the formation of non‐penetrated papillae is the predominant resistance response, while the hypersensitive response (HR) acts as a second line of defence, to cut the fungus off from nutrients, if penetration resistance fails. It is not clear yet what causes the slower growth and reduced colony size of triticale isolates when inoculated on wheat. Possibly, post‐penetration resistance mechanisms, other than HR, are switched on during these (semi‐) compatible interactions. Molecular studies on gene expression and gene function of defence‐related genes might reveal further insights into the genetic basis of these resistance responses.  相似文献   
28.
Despite the importance of noninfectious joint diseases in equine medicine, little is known about the acute phase response which may be elicited if the local inflammatory process of noninfectious arthritis is sufficiently strong, Therefore the aim of this study was to monitor the systemic inflammatory response during experimentally-induced noninfectious arthritis by studying the dynamics in serum of the acute phase proteins serum amyloid A (SAA), haptoglobin, fibrinogen and alpha2-globulins. Twenty-four Standardbred horses, age 3-7 years, found healthy on thorough clinical, radiological, haematological and serum biochemical examination, were injected aseptically into the right midcarpal joint with amphotericin B. Blood samples were drawn before induction of arthritis (0 h), and at 8, 16, 24, 36 and 48 h postinduction and then on Days 3, 4, 5 and 15 postinduction. All horses developed lameness with joint effusion and joint heat as well as increased respiratory rate, heart rate and body temperature. The lameness started to decline after 24-36 h and, in most animals, systemic signs disappeared on Day 2 postinjection. The concentration of the acute phase proteins increased following induction of arthritis. The SAA concentrations were higher than baseline concentrations from 16 h postinduction and were maximal at 36-48 h (227 times baseline concentration). The haptoglobin concentrations were higher than baseline concentrations from 24 h and were maximal at 48-96 h (1.14 times baseline concentration). The maximal concentrations of fibrinogen were seen between 36-72 h postinjection and increased on average 0.87 times from baseline concentrations. The fibrinogen concentrations were higher than baseline concentrations from 24 h postinjection. Alpha2-globulins concentrations showed a minor increase and increased 0.55 times from baseline concentrations. The markers had returned to baseline concentrations by Day 15. Our results demonstrate that amphotericin B-induced arthritis in a single joint gives rise to a systemic acute phase response measurable as increased concentrations in serum SAA, haptoglobin, fibrinogen and alpha2-globulins during the first 2 weeks of the condition and, thereby, that such an increase need not be indicative of infectious arthritis. Further research should be aimed at determining whether chronic noninfectious arthritis in the horse gives rise to increased acute phase protein concentrations in serum.  相似文献   
29.
ABSTRACT

Icelandic cattle is believed to have been brought from Norway during the settlement of Iceland around AD 870-930. Previous research on genetic relationships has indicated that Icelandic cattle is most related to northern Nordic indigenous breeds. Using single nucleotide polymorphism genotype data from Icelandic cattle and 29 Northern and Western European cattle breeds, we studied relationships and admixture among these breeds, and assessed population structure in Icelandic cattle. Population structure analysis through principal component analysis, estimation of ancestry, and analysis of patterns of population splitting and mixing revealed that Icelandic cattle are most related to three Finncattle breeds (Eastern, Northern and Western Finncattle), and Swedish Mountain cattle. Icelandic cattle has very low levels of admixture. We observed very limited population structure in Icelandic cattle. The observed structure was due to variable sire contributions. Over 1000 years of almost complete isolation has made Icelandic cattle highly genetically distinct from other cattle breeds.  相似文献   
30.
Objectives : To assess the feasibility of performing electrocardiography (ECG) and echocardiography on conscious ferrets and to establish reference values for this species under these conditions. Methods : End‐systolic and end‐diastolic left ventricular (LV) diameters, LV and interventricular septal thicknesses were measured by M‐mode echocardiography, while left atrial, aortic and pulmonary trunk diameters were determined by two‐dimensional echocardiography in 46 ferrets. In some animals the maximum velocities of blood flow in the aorta and the pulmonary trunk were also measured by spectral Doppler. ECG examinations were performed by using limb leads both in right lateral recumbency and in the so‐called “hanging” position. In the course of the ECG examinations (n=43), the occurrences, directions, durations and amplitudes of the P, QRS and T waves and the duration of the PR‐ and QT intervals were recorded for all six leads. Results : ECG and echocardiography were successfully performed on non‐sedated ferrets in 90 and 96% of the cases, respectively. Males were significantly heavier and had larger cardiac dimensions compared to females. Clinical Significance : Performance of both echocardiography and ECG are feasible techniques in conscious ferrets, and reference values are now available for future comparisons.  相似文献   
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