bluuebunny/crossref_metadata_2025_split huggingface dataset:
Local Habitat, Watershed, and Biotic Factors Influencing the Spread of Hybridization between Native Westslope Cutthroat Trout and Introduced Rainbow Trout
Authors: Muhlfeld Clint C. , McMahon Thomas E. , Boyer Matthew C. , Gresswell Robert E. 
Published: October 2009

AbstractThe invasion of nonnative fishes in freshwater systems is often facilitated by the interaction of biotic and abiotic factors operating at multiple spatial and temporal scales. We evaluated the association of local habitat features (width, gradient, and elevation), watershed characteristics (mean and maximum summer water temperatures, the number of road crossings, and road density), and biotic factors (the distance to the source of hybridization and trout density) with the spread of hybridization between native westslope cutthroat troutOncorhynchus clarkii lewisiand introduced rainbow troutO. mykissin the upper Flathead River system in Montana and British Columbia. The presence of hybridization and the proportion of rainbow trout admixture were estimated using seven diagnostic microsatellite loci. We defined logistic and linear regression models including various combinations of spatial and environmental factors and used an information‐theoretic approach to evaluate the relative plausibility of these models. Models combining measures of water temperature, disturbance, and source connectivity were the best‐approximating ones for the presence of hybridization. Hybridization was positively associated with mean summer water temperature and the number of upstream road crossings and negatively associated with the distance to the main source of hybridization. The best‐approximating models associated with the level of introgression among hybridized sites included measures of temperature, source connectivity, and the density of trout. The proportion of rainbow trout admixture was negatively related to the distance to the source and positively related to mean summer water temperature and density. Our results suggest that hybridization is more likely to occur and spread in streams with warm water temperatures, increased land use disturbance, and proximity to the main source of hybridization. However, habitat features alone may not limit the spread of hybridization; populations with high proportions of admixture and high densities may have to be reduced or eliminated.
The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
Authors: Shoup Daniel E. , Wahl David H. 
Published: October 2009

AbstractTurbidity in aquatic systems can change rapidly, affecting the visual ability of predators. Increased turbidity is known to reduce the reactive distance and foraging success of some planktivores and insectivores, leading to decreased growth rates. However, little is known about the effects of turbidity on prey selection by piscivores. We examined the interactions between largemouth bass Micropterus salmoides and their prey in 1.8‐m‐diameter tanks (58 cm deep) at four turbidity levels (0, 5, 10, and 40 nephelometric turbidity units [NTU]). Prey selectivity was significantly affected by turbidity. At lower turbidity levels (0 and 5 NTU), largemouth bass consumed mostly gizzard shad Dorosoma cepedianum and bluegills Lepomis macrochirus and had negative selectivity for northern crayfish Orconectes virilis. At 10 NTU, all three prey types had similar selectivity, presumably because the largemouth bass had more difficulty in capturing rapidly moving fish prey as their reactive distances decreased. At 40 NTU, the overall foraging rate was much lower and bluegills were selected significantly more often than the other prey types. Low light levels at the bottom of the tanks combined with reductions in visual clarity from clay sediments probably made it difficult for largemouth bass to feed effectively on virile crayfish at higher turbidities. Our results suggest that trophic interactions may be altered as turbidity levels change.
Young's Modulus and Degree of Conversion of Different Combination of Light-Cure Dental Resins
Authors: Emami N , Söderholm KJ 
Published: October 2009

Objectives:To evaluate Young's modulus and degree of conversion of several combinations of bisGMA, UEDMA, TEGDMA light-cure dental resin.Methods:Young's modulus and DC% were studied for 21 different resin combinations of bisGMA, TEGDMA and UEDMA. Small universal testing machine and photo-calorimetry were used for the tests. The results were evaluated using ANOVA and Duncan's multiple range tests and regular t-test.Results:Young's modulus varied between 2.37±0.2 GPa (100% TEGDMA) and 4.15±0.2 GPa (100% bisGMA). By adding TEGDMA to bisGMA or UEDMA, the Young's modulus decreased significantly (p<0.05). Degree of conversion was significantly (p<0.05) higher when the wt% of TEGDMA was high in the mixtures than for highly concentrated bis-GMA (resin mixtures with TEGDMA in comparison to mixture with bisGMA had higher degree of conversion). DC% was significantly higher (p<0.05) for binary mixtures of UEDMA and TEGDMA, and significantly lower for 100 wt% bis-GMA (p<0.05). The DC% values were between 53.1%±0.9% (100% bisGMA) and 85.6%±1% (80% UEDMA-20% TEGDMA). The concentration of bisGMA, in the monomer mixture, affected DC% and Young's modulus oppositely.Conclusions:The differences in the values for DC% were mostly justified by the differences in the molecular structures of the different monomers. It was also revealed that higher DC% does not always result in a higher Young's modulus, because molecular and network structural parameters play major roles in the final physical properties of the mixtures.
Cervical vertebral fracture in a Thoroughbred filly with minimal neurological dysfunction
Authors: Muno J. , Samii V. , Gallatin L. , Robertson J. , Chase J. 
Published: October 2009

SummaryVertebral fractures in horses are relatively common and often occur due to trauma. Clinical signs may range from neck pain and mild neurological dysfunction to tetraplegia and death. Severity of signs and prognosis depends on extent of damage to the spinal cord. In this Case Report, serial radiographs, which track the bony changes associated with fracture healing, were performed over one year. Although surgical techniques have been described to repair fractures to the vertebrae, patients with minimal neurological deficit may have a favourable outcome with conservative medical management, as in this case.
Scapula stress fractures in Thoroughbred racehorses: Eight cases (1997–2006)
Authors: Vallance S. A. , Lumsden J. M. , O'Sullivan C. B. 
Published: October 2009

No case series exists in the literature describing scapula stress fractures. The purpose of this study was to review the clinical findings, diagnostic images and outcome of 8 horses diagnosed with scapula stress fractures.Scapula stress fractures were seen in Thoroughbred racehorses displaying acute moderate forelimb lameness. Nuclear scintigraphy identified the mid‐distal scapula spine and/or scapula supraspinous fossa as predilection sites. Conservative management resulted in a good prognosis for return to racing, but stress fracture recurrence may be seen.
Multi‐modality diagnostic imaging of a cervical articular process fracture in a Thoroughbred horse including a novel C‐Arm imaging technique
Authors: Withers J. M. , Voûte L. C. , Lischer C. J. 
Published: October 2009

SummaryInterpretation of cervical radiographs can be challenging due to the complex anatomy and superimposition of osseous structures on either side of the vertebrae. This report describes the investigation of neck pain in a Thoroughbred gelding following a traumatic fall. Several imaging modalities were used to demonstrate the presence of a fracture of the left cranial articular process of the fourth cervical vertebra (C4), including nuclear scintigraphy, ultrasonography, oblique radiographic projections and a novel cineradiographic technique. Oblique radiographs were superior to standard lateral‐lateral radiographs in both the diagnosis and for monitoring the progression of healing of the articular process fracture in this case.
MR Imaging with Gadolinium in Patients with and without Post-Lumbar Puncture Headache
Authors: Hannerz Jan , Ericson K. , Bro Skejø H. P. 
Published: October 2009

Purpose: To study frequency and extent of meningeal enhancement in patients with and without post-lumbar puncture headache (PLPH) with cerebral MR with Gd-DTPA. Material and Methods: Ten consecutive patients with PLPH and 9 consecutive patients without PLPH were included in the study. Nine of the PLPH patients were reinvestigated when the PLPH was over and all non-PLPH patients during the week after the lumbar puncture. Results: Eight of the 9 patients with PLPH showed more enhancement of meningeal structures during PLPH than when PLPH had disappeared. The differences were slight in 5, more marked in 2, and pronounced in 1 patient. The 9th patient showed no change at all. In the 9 patients without PLPH, there was mainly slight enhancement before lumbar puncture and no change in enhancement after lumbar puncture as compared with before. Conclusion: PLPH is related to increased Gd-DTPA enhancement of the meninges, although the increase in enhancement during PLPH is minor in most cases. Pronounced enhancement of the meninges after lumbar puncture may predict long duration of the PLPH.
High Intensity Signal of the Posterior Pituitary
Authors: Arslan Arzu , Karaarslan E. , Dinçer A. 
Published: October 2009

Purpose: To evaluate the consistency of fat in the high intensity signals of the normal neurohypophysis and to differentiate the high signal of posterior pituitary from that of dorsum sella. Sagittal SE T1-weighted images with frequency encoding in the horizontal direction were used in order to differentiate the high signal of posterior pituitary and dorsum sella by the vertically-oriented chemical shift artifact. Material and Methods: The sellae of 46 normal volunteers were imaged with a commercially available fat suppression technique and SE sequences with frequency encoding in vertical (25 cases) and horizontal (21 cases) axes. Results: The high signal intensity was absent in 9% of the normal volunteers with no predilection to any specific age group. None of the cases with posterior pituitary high intensity signals showed suppression of the signal with fat suppression technique. A fat suppression technique was helpful in documenting the hyperintensity in 7% of normal volunteers. Nineteen of the 21 (90%) cases with high signal intensity were detected by routine SE T1-weighted images, whereas 18 of the 19 (95%) cases were detected by imaging with frequency encoding in the horizontal direction. Conclusion: The high signal does not indicate the presence of fat. Fat suppression technique and a horizontal direction of frequency encoding help in differentiating the high signal of the neurohypophysis from that of dorsum sella.
Kinematic MR Imaging in Surgical Management of Cervical Disc Disease, Spondylosis and Spondylotic Myelopathy
Authors: Muhle Claus , Metzner J. , Weinert D. , Schön R. , Rautenberg E. , Falliner A. , Brinkmann G. , Mehdorn H. M. , Heller M. , Resnick D. 
Published: October 2009

Purpose: To estimate the clinical value and influence of kinematic MR imaging in patients with degenerative diseases of the cervical spine. Material and Methods: Eighty-one patients were examined with a 1.5 T whole body magnet using a positioning device. Cervical disc disease was classified according to clinical and radiographic findings into 4 stages: stage I=cervical disc disease (n=13); stage II=spondylosis (n=42); stage III=spondylosis with restricted motion (n=11); and stage IV=cervical spondylotic myelopathya (n=15). Findings on kinematic MR images were compared to those on flexion and extension radiographs, myelography, CT-myelography and static MR imaging. Furthermore, the influence of kinematic MR imaging on surgical management and intra-operative patient positioning was determined. Results: Additional information obtained by kinematic MR imaging changed the therapeutic management in 7 of 11 (64%) patients with stage III disease, and in 13 of 15 (87%) patients with stage IV disease. Instead of an anterior approach, a posterior surgical approach was chosen in 3 of 11 patients (27%) with stage III disease and in 6 of 15 patients (40%) with stage IV disease. Hyperextension of the neck was avoided intra-operatively in 4 patients (27%) with cervical spondylotic myelopathy, and in 1 patient with stage II (2%) and in 1 patient with stage III (9%) disease. Kinematic MR imaging provided additional information in all patients with stages III and IV disease except in 1 patient with stage III disease, when compared to flexion and extension radiographs, myelography, CT-myelography and static MR examination. Conclusion: Kinematic MR imaging adds additional information when compared to conventional imaging methods in patients with advanced stages of degenerative disease of the cervical spine.
Thoracic CT Findings in Long-Term Hemodialysis Patients
Authors: Coşkun Mehmet , Boyvat F. , Bozkurt B. , Agildere A. M. , Niron E. A. 
Published: October 2009

Purpose: To evaluate thoracic CT findings of long-term hemodialysis patients. Material and Methods: Thoracic CT findings of 117 uremic patients (61 men, 56 women) with complaints of cough, dyspnea, low-grade pyrexia, malaise, weight loss, and profuse perspiration were retrospectively documented. Results: Atelectasis (60%), cardiomegaly (60%), pleural effusion (51%), vascular congestion (44%), parenchymal consolidation (38%), parenchymal scarring-fibrosis (31%), and lymphadenopathy (29%) were the most common CT findings in the thoraces of the long-term hemodialysis patients. Staphylococcus aureus was detected in 13 patients (11%) who had parenchymal infiltration. Thoracic tuberculosis was identified in 15 patients (13%), 11 of these cases being confined to the lung parenchyma, 3 to the pleura, and 1 involving the pleura and pericardium. Conclusion: In patients under long-term hemodialysis treatment, parenchymal consolidation, secondary to infectious agents such as S. aureus and Mycobacterium tuberculosis, is the most important CT finding since these lesions can be detected and treated successfully if they are considered as etiologic factors early on.
CT in Malignancy Grading and Prognostic Prediction of Non-Hodgkin's Lymphoma
Authors: Rodriguez Miriam , Rehn S. M. , Nyman R. S. , Sundström J. C. , Ahlström H. , Glimelius B. L. G. 
Published: October 2009

Purpose: The presence of tumor inhomogeneities in MR images of non-Hodgkin's lymphoma (NHL) provides information about malignancy grade and prognosis. The aim of this study was to determine whether CT images are also informative in these respects. Material and Methods: Sixty-three CT examinations in patients with NHL (32 high-grade and 31 low-grade tumors) were reviewed retrospectively by two senior radiologists. The tumor patterns were classified subjectively as homogeneous, slightly inhomogeneous or severely inhomogeneous and their relations to malignancy grade, clinical characteristics and prognosis were determined. Results: Sixteen out of 17 patients with a severely inhomogeneous tumor pattern had high-grade NHL tumors while 21 out of 29 patients with a homogeneous tumor appearance had low-grade NHL tumors. Among chemotherapy-treated patients, those with the highest degree of inhomogeneity had a significantly worse prognosis (9 out of 11 patients died). This relationship was not found in patients treated with radiotherapy. Conclusion: A severely inhomogeneous tumor pattern on CT images was found to be associated with a high malignancy grade in NHL. This CT pattern was also compatible with a poor prognosis in patients treated with chemotherapy.
MR Pyelography and Conventional MR Imaging in Urinary Tract Obstruction
Authors: Catalano C. , Pavone P. , Laghi A. , Scipioni A. , Panebianco V. , Brillo R. , Fraioli F. , Passariello R. 
Published: October 2009

Purpose: To evaluate the possible role of MR imaging in the assessment of patients with urinary tract obstruction by combining conventional MR imaging and MR pyelography (MRP). Material and Methods: Forty-three patients with dilated upper urinary tract were studied with a high gradient strength 0.5 T magnet. Respiratory compensated T1-weighted, SE and T2-weighted TSE sequences were acquired in all patients. MRP images were obtained by using a respiratory compensated 3D T2-weighted TSE sequence. MRP images were reconstructed with a MIP algorithm. In all cases, urography and/or ascending pyelography were also performed. Images were independently evaluated by two radiologists. Results: The dilated tract ureter and the level of the obstruction could be correctly demonstrated in all cases. The cause of the obstruction was correctly demonstrated by examiner 1 in 90% and by examiner 2 in 88%. The interobserver agreement was high with a kappa-value of 0.96. Conclusion: In cases of obstructive hydroureteronephrosis MR imaging, combining MRP and conventional sequences, can be proposed as an accurate technique in the assessment of level and cause of obstruction.
Renal Diuretic Duplex Doppler Sonography in Childhood Hydronephrosis
Authors: Akata D. , Haliloglu M. , Caglar M. , Tekgul S. , Özmen M. N. , Akhan O. 
Published: October 2009

Objective: The purpose of this study was to determine the diagnostic value of diuretic duplex Doppler sonography in distinguishing between obstructive and nonobstructive hydronephrosis in children by calculating the resistive indices (RI) before and after administration of furosemide. Material and Methods: We prospectively evaluated 28 kidneys (2 solitary) in 15 patients with unilateral or bilateral neonatal hydronephrosis. All patients underwent diuretic renography and duplex Doppler sonography before and after administration of furosemide. Results: According to the half-time drainage patterns at diuretic renography, 13 kidneys were classified as nonobstructed and 15 as obstructed. At baseline, the mean RI values of nonobstructed and obstructed kidneys were not significantly different (0.66 and 0.64, respectively). Ten minutes after the injection of furosemide, the mean RI values of the nonobstructed and obstructed kidneys were 0.68 and 0.70, respectively. The increase in RI over the baseline 10 min after the diuretic injection was statistically significant ( p<0.00001) in the obstructed kidneys. Conclusion: The baseline RI value of 0.70 is not a definite value for distinguishing obstructed from nonobstructed systems. An increase in RI of at least 10% over the baseline seems to be a more reliable criterion, especially when it is used in conjunction with diuretic renography.
Saline-Jet Aspiration Thrombectomy Catheter
Authors: Yamauchi T. , Furui S. , Okazaki M. , Higashihara H. , Matsui O. , Sakamoto T. , Tanaka T. , Kuribayashi S. , Takamiya M. , Sawada S. 
Published: October 2009

Purpose: To evaluate hydraulic thrombectomy using a saline-jet aspiration thrombectomy catheter in the treatment of venous thrombosis. Material and Methods: Ten patients underwent 12 hydraulic thrombectomy procedures using 2.7 or 4.0 mm catheters. The site of the thrombus was either central, peripheral or in portal veins. The age of the thrombi was between 2 and 60 days (mean 19.7 days). The efficacy of hydraulic thrombectomy was evaluated based on the aspirated thrombus ratio (ATR), i.e. the volume of the thrombus aspirated divided by the volume of the thrombus before thrombectomy. ATR was estimated by comparing the angiograms of the lesion before and after thrombectomy. Results: Soft thrombi were usually rapidly removed. ATR was >2/3 in 3, 2/3-1/3 in 2, 1/3-0 in 4, and 0 in 1 patient. The activation time of the injector was 23–224 s (mean 102 s) and the volume of aspirated blood was 30–680 ml (mean 250 ml). Compensatory infusion of saline was performed for blood loss, and 400 ml of packed red blood cells was transfused in 1 patient. No complications of the hydraulic thrombectomy were observed. Thrombolysis or additional treatment were performed in 9 patients. Conclusion: Hydraulic thrombectomy using this catheter can contribute to the treatment of venous thrombosis.
A Method to Evaluate the Performance of X-Ray Imaging Scintillators by Means of the Brightness-Sharpness Index (BSI)
Authors: Cavouras D. , Kandarakis I. , Prassopoulos P. , Kanellopoulos E. , Nomicos C. D. , Panayiotakis G. S. 
Published: October 2009

Purpose: To propose an image quality index, the brightness-sharpness index (BSI), for assessing the quality of the image produced by phosphors of medical imaging detectors. Material and Methods: BSI was evaluated by experimental X-ray luminescence and modulation transfer function measurements. BSI was determined for a number of test phosphor screens prepared from Gd2O2S:Tb, La2O2S:Tb, and Y2O2S:Tb phosphor materials. The screens covered a wide range of coating thicknesses from 50 to 150 mg/cm and measurements were performed for X-ray tube voltages between 50 and 120 kVp. Results: Gd2O2S:Tb phosphor exhibited higher brightness and sharpness, as compared to the other phosphor materials, for all screens and X-ray tube voltages used. Best Gd2O2S:Tb performance was observed for thin screens and high tube voltages. La2O2S:Tb exhibited higher BSI values than Y2O2S:Tb for medium and high tube voltages. Conclusion: Results showed that phosphor materials of high X-ray detection and X-ray-to-light conversion properties exhibit high BSI values indicating that BSI may provide a means of phosphor performance evaluation for imaging applications.
Clearance of Iopromide during Haemodialysis with High- and Low-Flux Membranes
Authors: Matzkies F. , Tombach B. , Kisters K. , Schuhmann G. , Hohage H. , Schaefer R. M. 
Published: October 2009

Purpose: The present clinical trial addressed the clearance of the contrast medium iopromide, a middle-sized molecule, during dialysis with high- and low-flux membranes. Material and Methods: Twenty chronic haemodialysis patients without residual renal function were dialysed either with low-flux haemophan or high-flux polyamide directly after application of the contrast medium. Iodine concentrations were determined by radiofluorescence methods. Results: Plasma concentrations of iodine before dialysis ranged between 1.1 and 3.9 mg/ml. The mean clearance rates for both membranes were comparable (110±1.4 ml/min high-flux and 108±1.9 ml/min low-flux), the sieving-coefficient was 0.83 for both membranes. After three hours of dialysis, 58% (high-flux) and 62% (low-flux) of iopromide was removed, half time of elimination was reached after 140±16 min (high-flux) and 122±11 min (low-flux). Conclusion: Our results demonstrated that elimination of iopromide is not dependent on the pore size of the membrane during dialysis. Due to higher blood flow rate, we found a higher elimination rate and a reduced half-time of elimination than prior investigations.