bluuebunny/crossref_metadata_2025 huggingface dataset:
THE EFFECT OF BODY WALL ON VIDEO SIGNAL ANALYSIS MEASUREMENTS
Authors: Waller Kenneth R. , Knipp Brian S. , O'Brien Robert T. , Zagzebski James A.
Published: May 2005

Rectangular body wall specimens were extracted from 16 juvenile swine and 9 adult beagle hounds after euthanasia. The body wall specimen included the epidermis to parietal membrane, with falciform fat removed. Ten images of a reference phantom with known attenuation and 10 additional images of the phantom with the specimen placed between the transducer and phantom surface were collected with a 5‐MHz ultrasound system and computer with frame grabber board. Mean pixel values were converted to relative echogenicities. Echogenicity versus depth yielded an estimate of attenuation. An unpaired t test was applied to compare reference attenuation values with and without body wall, and a Pearson correlation was applied to body Wall parameters versus measured attenuation through body wall. Measured attenuation through body wall increased significantly in dogs (P= 0.0016) and swine (P < 0.0001) when compared with phantom material alone. Increased attenuation positively correlated to body wall thickness (r= 0.6442) and mean gray level within body wall (r= 0.5069) for swine but not in canine. The presence of body wall in images used for video signal analysis significantly increases the measured attenuation in a phantom. This increase does not correlate with a measurable body wall parameter in dogs.
USE OF ULTRASOUND TO DIAGNOSE DIAPHRAGMATIC RUPTURE IN DOGS AND CATS
Authors: Spattini Giliola , Rossi Federica , Vignoli Massimo , Lamb Christopher R.
Published: May 2005

Twenty‐one cats and six dogs that presented to a first‐opinion clinic with signs of dyspnea and muffled cardiac auscultation received ultrasonography to look for signs of diaphragmatic rupture. The presence or absence of diaphragmatic rupture was subsequently determined on the basis of unequivocal radio‐graphic signs, surgical findings, or necropsy. Consistent findings in animals with diaphragmatic rupture were irregular or asymmetric cranial aspect of the liver and abdominal viscera in the thorax. Accuracy of ultrasonography was 25/27 (93%). One false‐negative result occurred in a cat with a chronic diaphragmatic rupture in which adhesions between the liver and lung simulated the appearance of an intact diaphragm. One false‐positive result occurred in a dog with an abscess involving the left lung and pleural cavity, which was misinterpreted as the stomach. The results of this study support use of ultrasonography in animals with suspected diaphragmatic rupture.
MAGNETIC RESONANCE IMAGING OF THE PRESUMED NORMAL CANINE ADRENAL GLANDS
Authors: Llabres‐Diaz Francisco J. , Dennis Ruth
Published: May 2005

Forty‐three dogs without evidence of endocrine disease that underwent spinal or abdominal magnetic resonance imaging (MRI) for clinical reasons were studied. Because the procedures were not optimized for inclusion of the adrenal glands, they were not always visible in all planes. Eighty‐five of the 86 adrenal glands were seen and only the left gland in a 6‐month‐old Irish wolfhound could not be found. The right adrenal gland lay cranial to the left in all of the animals in which both glands were seen. The best landmarks for localization of the glands were vascular; both adrenal glands were always cranial to the ipsilateral renal vessels and in the region of the celiac and cranial mesenteric arteries. Various measurements were made on all the available scan planes. In some dogs the whole adrenal gland was difficult to visualize clearly, and this hindered the measuring process, especially when the right adrenal gland was in close contact with the caudal vena cava. The adrenal glands were mainly linear in shape but also had a variable degree of modification of their poles, especially the cranial pole of the right adrenal gland, which tended to be consistently wider and to present different shapes (rounded, arrowhead, inverted P, hook‐shaped, triangular, or dome‐shaped). Two main patterns of signal intensity were seen on fast spin echo (FSE) sequences (T2‐weighted, T1‐weighted, and T1‐weighted after administration of a paramagnetic contrast medium): homogeneous and hypointense to surroundings or a corticomedullary type pattern with a hyperintense central area surrounded by a hypointense rim of tissue. The outline of the left adrenal gland was always very clear. The clarity of outline of the right adrenal gland was more variable, especially if it was in contact with the liver or the caudal vena cava. It was felt that the amount of retroperitoneal fat was not as important as stated in the human literature for visualization of the adrenal glands and that with an appropriate selection of scan planes and pulse sequences good assessment of the adrenal glands can be performed with MRI in canine patients.
RADIOGRAPHIC FEATURES OF AORTIC BULB/VALVE MINERALIZATION IN 20 DOGS
Authors: Douglass James P. , Berry Clifford R. , Thrall Donald E. , Malarkey David E. , Spaulding Kathy A.
Published: May 2005

The radiographic features of aortic bulb/valve mineralization in 20 dogs were reviewed. Extent, shape, number, and location of mineralization were recorded. Five of the dogs had additional alternate imaging examinations, including bone scintigraphy, echocardiography, and thoracic computed tomography. A necropsy was done on one dog, and the area of mineralization was evaluated using routine histology. The median age was 10 (mean 9.7; SD ± 2.7) years. There were five males, seven neutered males, one female, and seven neutered females. The breeds were: Irish setter (6); rottweiler (7); chow‐chow (1); miniature dachshund (1); borzoi (1); English setter (1); English springer spaniel (1); great Dane (1); and greyhound (1). Dogs with both right and left lateral radiographs (n = 17) had mineralization visible on both views, more conspicuously on the right lateral radiograph (n = 12). Aortic bulb mineralization was identified on the ventrodorsal radiograph of only one dog. On lateral radiographs, the aortic bulb mineralization was localized within the 4th intercostal space and in the craniodorsal quadrant of the cardiac silhouette. In nine of the dogs, there were complex or multiple mineralizations and in 11 dogs, there was a single curvilinear mineral opacity oriented in a caudoventral to craniodorsal direction. In all radiographs, the mineralization was in the expected position of the aortic bulb, and echocardiography (n = 4), spiral computed tomography (n = 2), and necropsy (n = 1) confirmed that the mineralization was within the aortic bulb. Clinical pathologic data of the dogs suggested no reason for metastatic mineralization. Exact etiopathogenesis of the lesions were not determined in this study. Based on the histologic findings in one dog, the mineralization seen in the aortic root is similar to a form of dystrophic mineralization called Monckeberg's calcific arteriosclerosis in humans. No clinical signs attributable to the mineralization were observed.
TRANSVENOUS COIL EMBOLIZATION OF PORTOSYSTEMIC SHUNT IN DOGS
Authors: Léveillé Renée , Johnson Susan E. , Birchard Stephen J.
Published: May 2005

This paper describes transvenous coil embolization of portosystemic shunt in 10 dogs. Clinical signs resolved in 4 dogs with extrahepatic shunt, and in 3 dogs with intrahepatic shunt. Two dogs of less than 3 kg died because of migration of coils to the level of the main pulmonary artery. One dog was euthanized when acute portal hypertension developed following transvenous coil embolization. Trans–venous coil embolization seems to be a less invasive alternative to surgical ligation in dogs with a single intrahepatic portosystemic shunt.
SIMULTANEOUS CONGENITAL AND ACQUIRED EXTRAHEPATIC PORTOSYSTEMIC SHUNTS IN TWO DOGS
Authors: Ferrell Eric A. , Graham John P. , Hanel Rita , Randell Susan , Farese James P. , Castleman William L.
Published: May 2005

Two dogs with simultaneous congenital and acquired portosystemic shunts are reported. The first dog was an eight–month‐old, male Golden Retriever with a history of peritoneal effusion, polyuria/ polydipsia, and stunted growth. The dog had a microcytic, hypochromic anemia, a mildly elevated AST, and a moderate to severely elevated preprandial and postprandial serum bile acids. Transcolonic portal scintigraphy confirmed the presence of a portosystemic shunt. An intraoperative mesenteric portogram was performed. Two conjoined congenital extrahepatic portosystemic shunts and multiple acquired extrahepatic portosystemic shunts were identified. The second dog was a five‐month‐old, mixed breed with two week history of peritoneal effusion. Abdominal ultrasound and transcolonic scintigraphy were used to diagnose a portosystemic shunt. A single extrahepatic portosystemic shunt, portal hypertension, and multiple acquired collateral shunts were identified at surgery. The histologic alterations observed in these dogs were consistent with a portosystemic shunt. In these dogs, the presence of congenital and acquired portosystemic shunts and histopathologic findings are considered to represent a combination of congenital portosystemic shunts and noncirrhotic portal hypertension or portal vein hypoplasia.
RADIOGRAPHY AND IMAGE‐INTENSIFIED FLUOROSCOPY OF BARIUM PASSAGE THROUGH THE GASTROINTESTINAL TRACT IN SIX HEALTHY AMAZON PARROTS (AMAZONA AESTIVA)
Authors: Vink‐Nooteboom Mariette , Lumeij J.T. , Wolvekamp W.T.C.
Published: May 2005

Gastrointestinal contrast studies were performed in six clinically healthy blue‐fronted Amazon parrots (Amazona aestiva) using radiography and image‐intensified fluoroscopy. During examination, the birds were confined in a perspex cage. The quality of the lateral radiographs was adequate for assessment of the contrast medium‐filled gastrointestinal tract. Thirty minutes after administration of 20 mL/kg of a 25% barium sulphate suspension directly in the crop, in all birds the ventriculus was totally outlined by barium. After 60 min, the small intestine was filled in five of six birds. After 180 min, the crop was empty in all birds. The barium‐outlined ventriculus had differences in shape on radiographs of individual birds and also between birds. The colon and cloaca had further filling after 120 to 300 min. With image‐intensified fluoroscopy, gastrointestinal motility was evaluated. Contractions of the crop were seen, and boluses of contrast medium passing through the esophagus toward the proventriculus were easily identified. Proventricular contractions were rarely noted, but ventriculus motility was present and clearly defined. The ventriculus had a mean of 3.7 contraction cycles/min. In the duodenum and small intestine, rapid antegrade and retrograde peristaltic movements in combination with segmental contractions were seen. In the colon, occasionally very slow peristaltic activity, mainly of segmental nature, was present. During the examinations, no defeacation was recorded. Confinement in a small perspex cage provides an adequate and handy radiological set–up for evaluation of gastrointestinal passage and motility in birds, minimizing the influences of stress and anesthesia.
ACCURACY AND PRECISION OF DUAL‐ENERGY X‐RAY ABSORPTIOMETRY FOR EX VIVO DETERMINATION OF MINERAL CONTENT IN TURKEY POULT BONES
Authors: Zotti Alessandro , Rizzi Chiara , Chiericato Gianmaria , Bernardini Daniele
Published: May 2005

The right humerus was removed from 30 20‐week‐old male turkey poults for humerus strength analysis using dual‐energy x‐ray absorptiometry and humerus‐breaking strength. Specimens were cleaned and dried before scanning. To determine the most precise and accurate protocol of bone densitometry analysis for avian long bones, we scanned each specimen using five different techniques, all aimed to simulate soft‐tissue thickness. Correlation coefficients and linear regression equations between 1) bone mineral content and humerus ash, and 2) bone mineral density and humerus‐breaking strength were estimated with each technique and compared. The coefficient of variation values for precision ranged from 0.40% to 1.69% for bone mineral content and from 0% to 4.19% for bone mineral density. The accuracy was determined by comparing the bone mineral content of each humerus with the corresponding ash weight; the correlation coefficients between the two parameters were highly significant (range 0.949–0.963;P≤0.01). Significant correlations were also observed between humerus‐breaking strength and bone density measurements (range 0.762–0.785;P≤0.01). Linear regression coefficients relating both parameters considered were also highly significant. We concluded that dual‐energy x‐ray absorptiometry is an accurate and precise method with which to determine ex vivo bone mineral content and strength in turkey bones. Further investigations are requested for field applications of this method to study factors affecting bone physiology and strength.
BALLOON DILATATION OF NASOPHARYNGEAL STENOSIS IN A CAT
Authors: Boswood Adrian , Lamb Christopher R. , Brockman Daniel J. , Mantis Panagiotis , Witt Angela L.
Published: May 2005

A cat was diagnosed with nasopharyngeal stenosis on the basis of clinical signs, survey and contrast radiography, endoscopy and magnetic resonance imaging. The condition was successfully managed with repeated balloon dilatation.
EFFECT OF PERINEURAL ANESTHESIA ON THE ULTRASONOGRAPHIC APPEARANCE OF EQUINE PALMAR METACARPAL STRUCTURES
Authors: Zekas Lisa J. , Forrest Lisa J.
Published: May 2005

The purpose of this study was to describe ultrasonographic changes of the equine palmar metacarpal area attributed to the infiltration of local anesthetic solution and to determine whether these changes were noted immediately or at 24 h. The palmar metacarpal region of one forelimb in each of six horses was examined ultrasonographically with a 10‐MHz linear array transducer and a 7.5‐MHz curvilinear trans‐ducer. Transverse and longitudinal images were recorded at 5‐cm intervals distal to the accessory carpal bone. High and low palmar and palmar metacarpal nerve blocks were performed with a 2% mepivacaine hydrochloride solution. Ultrasonographic examinations similar to the initial examination then were performed immediately, 1 h and 24 h postinjection. Cross‐sectional area and mean pixel value were determined for the superficial and deep digital flexor tendons, the accessory ligament of the deep digital flexor tendon, the suspensory ligament, and the suspensory branches at each level and time period. Subjective ultra‐sonographic changes also were noted. No significant difference was noted in the cross‐sectional area or mean pixel value of any structure at any level or time period compared to baseline. Subjective changes in the tendons and ligaments were not noted. There was mild hypoechoic swelling of the surrounding soft tissues and gas in the region of the injections. Gas could interfere with the evaluation of the origin of the suspensory ligament and the proximal portion of the accessory ligament of the deep digital flexor tendon within the first hour but was not detectable ultrasonographically at 24 h. Based on these findings, if gas interferes with an ultrasonographic examination performed temporally close to perineural anesthesia, a repeat examination at 24 h is recommended.
ULTRASONOGRAPHIC DIAGNOSIS OF FOREIGN BODIES ASSOCIATED WITH CHRONIC DRAINING TRACTS AND ABSCESSES IN DOGS
Authors: Armbrust Laura J. , Biller David S. , Radlinsky Maryann G. , Hoskinson James J.
Published: May 2005

This is a retrospective study that describes the historical, physical exam, radiographic, fistulographic, ultrasonographic, and surgical findings associated with non‐gastrointestinal and extrathoracic foreign bodies in six dogs. All dogs had a chronic draining tract or abscess. Although radiographs were obtained in five of the six dogs, no foreign bodies were identified with this modality. Fistulography was performed in four of the six dogs, and a filling defect consistent with a foreign body was found in two of four dogs. A foreign body was identified in five of the six dogs with ultrasound. Foreign bodies were removed surgically in five of six dogs. This report clarifies the importance of ultrasound in the evaluation of chronic draining tracts and abscesses in dogs.
COMBINED USE OF ULTRASONOGRAPHY AND CONTRAST ENHANCED COMPUTED TOMOGRAPHY TO EVALUATE ACUTE NECROTIZING PANCREATITIS IN TWO DOGS
Authors: Jaeger Jordan Q. , Mattoon John S. , Bateman Shane W. , Morandi Federica
Published: May 2005

The imaging findings in two miniature schnauzers with acute necrotizing pancreatitis are described. Both dogs were treated previously for diabetes mellitus and hyperlipidemia. Vomiting, anorexia, and lethargy were observed in both dogs at presentation. Laboratory evaluations supportive of pancreatitis included left shift, abnormally high serum amylase and lipase activities, hypocalcemia, and abnormally high serum activities of liver enzymes. Sonographically, both dogs had diffusely enlarged hypoechoic pancreatic tissue with anechoic foci compatible with necrosis, abscessation, phlegmon, and pseudocysts formation. Contrast‐enhanced computed tomography (CT) findings in both dogs were compatible with pancreatic necrosis. Dog 1 was managed medically for 11 days. Follow‐up CT scan in this dog disclosed decreased pancreatic size and increased contrast enhancement compatible with partial resolution of pancreatitis.
ULTRASONOGRAPHIC DIAGNOSIS‐SMALL BOWEL INFARCTION IN A CAT
Authors: Wallack Seth T. , Hornof William J. , Herrgesell Eric J.
Published: May 2005

An 8‐year‐old, domestic short hair cat with a known history of hypertrophic cardiomyopathy and previous aortic thromboembolism was presented for 24 h of vomiting and pyrexia. Initial abdominal radiographs were unremarkable. On an upper gastrointestinal series, delayed gastric emptying and prolonged small intestinal transit time were found. An initial abdominal ultrasound revealed a focal region of aperistaltic small intestine with mild wall thickening, however, intestinal wall layering in this area appeared normal. By 72 h, there was a diffusely hypoechoic portion of thickened small bowel (0.51 cm) with loss of the normal layering and hyperechoic mesentery surrounding this segment of bowel. A small bowel infarction and focal peritonitis were suspected and confirmed at surgery.
DETERMINATION OF TIME OF ONSET AND LOCATION OF EARLY SKELETAL LESIONS IN YOUNG DOGS EXPERIMENTALLY INFECTED WITHHEPATOZOON AMERICANUMUSING BONE SCINTIGRAPHY
Authors: Drosty Wm Tod , Cummings Connie A. , Mathew J.S. , Panciera Roger J. , Jeff C.H. KO
Published: May 2005

Canine hepatozoonosis caused byHepatozoon americanumhas periosteal proliferation on long bones, pelvis, vertebrae, and skull. The pathogenesis of the periosteal proliferation is unknown but may be similar to hypertrophic osteopathy. Objectives were to determine the time frame for onset of bone lesions, to characterize spatial distribution of early bone lesions, and to describe the scintigraphic appearance of bone lesions in six immature dogs infected with 400 H.americanumoocysts on day 0.99mTc‐MDP bone scintigraphy was performed before and after infection. The onset bone lesions noted using scintigraphy was before day 35/36 in three dogs, day 46 in one dog, day 53 in one dog, and between days 46 and 67 in one dog. Early bone lesions primarily occur proximal to the carpus/tarsus and on the axial skeleton. Bone lesions were diffuse, bilaterally symmetric, homogenous, high intensity regions of radiopharmaceutical uptake.
Clonal Dominance of Hematopoietic Stem Cells Triggered by Retroviral Gene Marking
Authors: Kustikova Olga , Fehse Boris , Modlich Ute , Yang Min , Düllmann Jochen , Kamino Kenji , von Neuhoff Nils , Schlegelberger Brigitte , Li Zhixiong , Baum Christopher
Published: May 2005

Gene marking with replication-defective retroviral vectors has been used for more than 20 years to track the in vivo fate of cell clones. We demonstrate that retroviral integrations themselves may trigger nonmalignant clonal expansion in murine long-term hematopoiesis. All 29 insertions recovered from clones dominating in serially transplanted recipients affected loci with an established or potential role in the self-renewal or survival of hematopoietic stem cells. Transcriptional dysregulation occurred in all 12 insertion sites analyzed. These findings have major implications for diagnostic gene marking and the discovery of genes regulating stem cell turnover.
Functional Interaction Between ß-Catenin and FOXO in Oxidative Stress Signaling
Authors: Essers Marieke A. G. , de Vries-Smits Lydia M. M. , Barker Nick , Polderman Paulien E. , Burgering Boudewijn M. T. , Korswagen Hendrik C.
Published: May 2005

β-Catenin is a multifunctional protein that mediates Wnt signaling by binding to members of the T cell factor (TCF) family of transcription factors. Here, we report an evolutionarily conserved interaction of β-catenin with FOXO transcription factors, which are regulated by insulin and oxidative stress signaling. β-Catenin binds directly to FOXO and enhances FOXO transcriptional activity in mammalian cells. In
Caenorhabditis elegans
, loss of the β-catenin BAR-1 reduces the activity of the FOXO ortholog DAF-16 in dauer formation and life span. Association of β-catenin with FOXO was enhanced in cells exposed to oxidative stress. Furthermore, BAR-1 was required for the oxidative stress–induced expression of the DAF-16 target gene
sod-3
and for resistance to oxidative damage. These results demonstrate a role for β-catenin in regulating FOXO function that is particularly important under conditions of oxidative stress.
The Highland Mangabey
Lophocebus kipunji
: A New Species of African Monkey
Authors: Jones Trevor , Ehardt Carolyn L. , Butynski Thomas M. , Davenport Tim R. B. , Mpunga Noah E. , Machaga Sophy J. , De Luca Daniela W.
Published: May 2005

A distinct species of mangabey was independently found at two sites 370 kilometers apart in southern Tanzania (Mount Rungwe and Livingstone in the Southern Highlands and Ndundulu in the Udzungwa Mountains). This new species is described here and given the name “highland mangabey”
Lophocebus kipunji
sp. nov. We place this monkey in
Lophocebus
, because it possesses noncontrasting black eyelids and is arboreal.
L. kipunji
is distinguished from other mangabeys by the color of its pelage; long, upright crest; off-white tail and ventrum; and loud call. This find has implications for primate evolution, African biogeography, and forest conservation.
Wet Electrons at the H
2
O/TiO
2
(110) Surface
Authors: Onda Ken , Li Bin , Zhao Jin , Jordan Kenneth D. , Yang Jinlong , Petek Hrvoje
Published: May 2005

At interfaces of metal oxide and water, partially hydrated or “wet-electron” states represent the lowest energy pathway for electron transfer. We studied the photoinduced electron transfer at the H
2
O/TiO
2
(110) interface by means of time-resolved two-photon photoemission spectroscopy and electronic structure theory. At ∼1-monolayer coverage of water on partially hydroxylated TiO
2
surfaces, we found an unoccupied electronic state 2.4 electron volts above the Fermi level. Density functional theory shows this to be a wet-electron state analogous to that reported in water clusters and which is distinct from hydrated electrons observed on water-covered metal surfaces. The decay of electrons from the wet-electron state to the conduction band of TiO
2
occurs in ≤15 femtoseconds.
Mutations in
Col4a1
Cause Perinatal Cerebral Hemorrhage and Porencephaly
Authors: Gould Douglas B. , Phalan F. Campbell , Breedveld Guido J. , van Mil Saskia E. , Smith Richard S. , Schimenti John C. , Aguglia Umberto , van der Knaap Marjo S. , Heutink Peter , John Simon W. M.
Published: May 2005

Porencephaly is a rare neurological disease, typically manifest in infants, which is characterized by the existence of degenerative cavities in the brain. To investigate the molecular pathogenesis of porencephaly, we studied a mouse mutant that develops porencephaly secondary to focal disruptions of vascular basement membranes. Half of the mutant mice died with cerebral hemorrhage within a day of birth, and ∼18% of survivors had porencephaly. We show that vascular defects are caused by a semidominant mutation in the procollagen type IV α 1 gene (
Col4a1
) in mice, which inhibits the secretion of mutant and normal type IV collagen. We also show that
COL4A1
mutations segregate with porencephaly in human families. Because not all mutant mice develop porencephaly, we propose that
Col4a1
mutations conspire with environmental trauma in causing the disease.
Deterministic Coupling of Single Quantum Dots to Single Nanocavity Modes
Authors: Badolato Antonio , Hennessy Kevin , Atatüre Mete , Dreiser Jan , Hu Evelyn , Petroff Pierre M. , Imamoğlu Atac
Published: May 2005

We demonstrate a deterministic approach to the implementation of solid-state cavity quantum electrodynamics (QED) systems based on a precise spatial and spectral overlap between a single self-assembled quantum dot and a photonic crystal membrane nanocavity. By fine-tuning nanocavity modes with a high quality factor into resonance with any given quantum dot exciton, we observed clear signatures of cavity QED (such as the Purcell effect) in all fabricated structures. This approach removes the major hindrances that had limited the application of solid-state cavity QED and enables the realization of experiments previously proposed in the context of quantum information processing.
Seeing with the Mind's Eye
Authors: Joyce Phil
Published: May 2005

Mindsight
Image, Dream, Meaning.
By Colin McGinn
. Harvard University Press, Cambridge, MA, 2004. 217 pp. $27.95, £18.95, €25.80. ISBN 0-674-01560-6.

The author offers a philosophical exploration of the imagination and its relation with perception.
A Cost of Long-Term Memory in
Drosophila
Authors: Mery Frederic , Kawecki Tadeusz J.
Published: May 2005

Two distinct forms of consolidated associative memory are known in
Drosophila
: long-term memory and so-called anesthesia-resistant memory. Long-term memory is more stable, but unlike anesthesia-resistant memory, its formation requires protein synthesis. We show that flies induced to form long-term memory become more susceptible to extreme stress (such as desiccation). In contrast, induction of anesthesia-resistant memory had no detectable effect on desiccation resistance. This finding may help to explain why evolution has maintained anesthesia-resistant memory as another form of consolidated memory, distinct from long-term memory.
An Active Role for tRNA in Decoding Beyond Codon:Anticodon Pairing
Authors: Cochella Luisa , Green Rachel
Published: May 2005

During transfer RNA (tRNA) selection, a cognate codon:anticodon interaction triggers a series of events that ultimately results in the acceptance of that tRNA into the ribosome for peptide-bond formation. High-fidelity discrimination between the cognate tRNA and near- and noncognate ones depends both on their differential dissociation rates from the ribosome and on specific acceleration of forward rate constants by cognate species. Here we show that a mutant tRNA
Trp
carrying a single substitution in its D-arm achieves elevated levels of miscoding by accelerating these forward rate constants independent of codon:anticodon pairing in the decoding center. These data provide evidence for a direct role for tRNA in signaling its own acceptance during decoding and support its fundamental role during the evolution of protein synthesis.
The Great Sumatra-Andaman Earthquake of 26 December 2004
Authors: Lay Thorne , Kanamori Hiroo , Ammon Charles J. , Nettles Meredith , Ward Steven N. , Aster Richard C. , Beck Susan L. , Bilek Susan L. , Brudzinski Michael R. , Butler Rhett , DeShon Heather R. , Ekström Göran , Satake Kenji , Sipkin Stuart
Published: May 2005

The two largest earthquakes of the past 40 years ruptured a 1600-kilometer-long portion of the fault boundary between the Indo-Australian and southeastern Eurasian plates on 26 December 2004 [seismic moment magnitude (
M
w
) = 9.1 to 9.3] and 28 March 2005 (
M
w
= 8.6). The first event generated a tsunami that caused more than 283,000 deaths. Fault slip of up to 15 meters occurred near Banda Aceh, Sumatra, but to the north, along the Nicobar and Andaman Islands, rapid slip was much smaller. Tsunami and geodetic observations indicate that additional slow slip occurred in the north over a time scale of 50 minutes or longer.
Rupture Process of the 2004 Sumatra-Andaman Earthquake
Authors: Ammon Charles J. , Ji Chen , Thio Hong-Kie , Robinson David , Ni Sidao , Hjorleifsdottir Vala , Kanamori Hiroo , Lay Thorne , Das Shamita , Helmberger Don , Ichinose Gene , Polet Jascha , Wald David
Published: May 2005

The 26 December 2004 Sumatra-Andaman earthquake initiated slowly, with small slip and a slow rupture speed for the first 40 to 60 seconds. Then the rupture expanded at a speed of about 2.5 kilometers per second toward the north northwest, extending 1200 to 1300 kilometers along the Andaman trough. Peak displacements reached ∼15 meters along a 600-kilometer segment of the plate boundary offshore of northwestern Sumatra and the southern Nicobar islands. Slip was less in the northern 400 to 500 kilometers of the aftershock zone, and at least some slip in that region may have occurred on a time scale beyond the seismic band.
Earth's Free Oscillations Excited by the 26 December 2004 Sumatra-Andaman Earthquake
Authors: Park Jeffrey , Song Teh-Ru Alex , Tromp Jeroen , Okal Emile , Stein Seth , Roult Genevieve , Clevede Eric , Laske Gabi , Kanamori Hiroo , Davis Peter , Berger Jon , Braitenberg Carla , Van Camp Michel , Lei Xiang'e , Sun Heping , Xu Houze , Rosat Severine
Published: May 2005

At periods greater than 1000 seconds, Earth's seismic free oscillations have anomalously large amplitude when referenced to the Harvard Centroid Moment Tensor fault mechanism, which is estimated from 300- to 500-second surface waves. By using more realistic rupture models on a steeper fault derived from seismic body and surface waves, we approximated free oscillation amplitudes with a seismic moment (6.5 × 10
22
Newton·meters) that corresponds to a moment magnitude of 9.15. With a rupture duration of 600 seconds, the fault-rupture models represent seismic observations adequately but underpredict geodetic displacements that argue for slow fault motion beneath the Nicobar and Andaman islands.
A Flying Start, Then a Slow Slip
Authors: Bilham Roger
Published: May 2005

The human tragedy caused by the Sumatra-Andaman earthquake (moment magnitude 9.3) on 26 December 2004 and its companion Nias earthquake (moment magnitude 8.7) on 28 March 2005 is difficult to comprehend. These earthquakes, the largest in 40 years, have also left seismologists searching for the words and tools to describe the enormity of the geological processes involved. Four papers in this issue discuss aspects of a rupture process of surprising complexity, the first such event to test the sensitivity and range of many new technologies. A surprising feature of the earthquake is that after the initial rapid rupture, subsequent slip of the plate interface occurred with decreasing speed toward the north.
Paludification and management of forested peatlands in Canada: a literature review
Authors: Lavoie Martin , Paré David , Fenton Nicole , Groot Arthur , Taylor Kim
Published: May 2005

The Clay Belt region of Quebec and Ontario supports a large forest resource and an important forest industry. In this region, the majority of the harvested volume allotted to forest companies is in forested peatlands and boreal forests prone to paludification. Paludification is the accumulation of organic matter over time, and is generally believed to be caused by increasing soil moisture and Sphagnum colonization. Paludification is influenced by external and internal factors; it reduces soil temperature, decomposition rates, microbial activity, and nutrient availability. As a result, paludification may lead to lower site productivity with time after disturbance. Therefore, in harvested stands with a thick organic matter layer, low soil disturbance (as opposed to fire) and water table rise may create favourable conditions for paludification that may ultimately be detrimental to timber production. Past experiences suggest several solutions to prevent or control the negative effects of paludification. Drainage and fertilization applied together are generally good techniques to control paludification and to improve tree productivity. On the other hand, we suggest that site preparation as well as prescribed burning, preceded or not by drainage, are avenues of research that deserve to be explored because they hold the potential to control or even reverse paludification, especially where peat accumulation is caused by natural succession or where lateral peat expansion has occurred. Key words: paludification, forested peatland, productivity, wildfire, careful logging, soil disturbance.
Identification of the ecological requirements of important terrestrial ecotoxicological test species
Authors: Jänsch S , Amorim M J , Römbke J
Published: May 2005

For about 20 years, standardized soil ecotoxicological tests have relied on the use of an artificial soil substrate (e.g., Organisation for Economic Co-operation and Development; OECD). For both the extrapolation of data obtained in the laboratory to the field situation, as well as the biological assessment of contaminated sites, this approach alone is not sufficient anymore. For this reason a literature review has been performed to investigate the ecological requirements of important terrestrial ecotoxicological test species. The invertebrate species included were Eisenia fetida, E. andrei (earthworms), Enchytraeus albidus, E. crypticus (potworms), Folsomia candida (springtails), and Hypoaspis aculeifer (predatory mites). The ecological parameters included were pH, moisture content, temperature, soil (i.e., texture, water-holding capacity, organic matter content, etc.), and food. The results indicate that most of these species should be applicable to a wide range of natural soils, while for some "extreme" soils (e.g., very acid forest soils) alternative test species will be required. Thus, further research is required to identify such species as well as to fill the gaps of knowledge concerning the ecological requirements of the species investigated here. Key words: Collembola, Enchytraeidae, Gamasid mites, Lumbricidae, natural soils.
Resource matching across habitats is limited by competition at patch scales in an estuarine-opportunist fish
Authors: Polivka Karl M
Published: May 2005

I used field observations, assays, and experiments with the euryhaline cottid Cottus aleuticus to evaluate the extent to which average resource availability drives the large-scale distribution of these fish among upstream and estuarine habitats and how interspecific competition from a congener affects its performance in the estuary. Population densities of C. aleuticus were only consistent with resource densities across years during two of five study years, indicating a lack of resource matching at large temporal scales. On shorter temporal scales, fish growth rates that were two to three times higher in the estuary compared with the stream were inconsistent with the predictions of resource matching theory. A manipulation of C. aleuticus density showed that the estuary could support at least twice the number of individuals that occurred there; thus, the profitable estuary is underutilized. Interspecific competition with Cottus asper was partially responsible for this underutilization as indicated by a substantial reduction in growth and condition among C. aleuticus individuals in experimental manipulations that compared intra- and inter-specific effects. Observed spatial overlap between these two cottids combined with the results of the competition experiment suggests that C. aleuticus is more strongly limited in its ability to use estuarine habitats opportunistically by interspecific competition than by intraspecific competition.
Effects of variability in spacing of coastal marine reserves on fisheries yield and sustainability
Authors: Kaplan David M , Botsford Louis W
Published: May 2005

The size and configuration of marine reserves best suited to reaching fisheries and conservation goals are poorly understood. It has been suggested that variable spacing between reserves is essential to the success of a system of marine reserves. We used numerical models to examine the effect of variable spacing on the efficacy of marine reserves for managing a fish species with sedentary adults and planktonic larvae. Variability in reserve spacing affected catch and recruitment relative to values for a uniform configuration of reserves only for populations near collapse even in the presence of a system of reserves. For species with low fishing rates or large marine reserves, variability in spacing had only a minor effect. At high fishing rates and small reserve sizes, variable reserve placement had a positive local effect on catch and recruitment when several reserves fell close to each other. These configurations led to uneven spatial distributions with greater catch and recruitment in areas with a higher concentration of reserves. Variable reserve spacing can offer additional protection to overfished populations along certain sections of the coastline, but concern for spatial homogeneity will argue for a uniform distribution of reserves covering an adequate proportion of the entire coastline.
Practical application of meta-analysis results: avoiding the double use of data
Authors: Minte-Vera C V , Branch T A , Stewart I J , Dorn M W
Published: May 2005

Meta-analysis is an important new tool for synthesizing scientific knowledge from many previous studies. In fisheries, meta-analyses can be used to obtain prior distributions or penalty functions for parameters used in stock assessment models. Two types of results are generally published in a meta-analysis: Type A, the updated results for each stock used in the meta-analysis, and Type B, the results that would best describe a new stock. Including these results in assessments for the individual stocks would result in double use of the data if the assessments include the input data used in the meta-analyses, which they typically would. To solve this problem, we recommend that an additional form of results should be reported in meta-analyses: Type C, the results for a new stock obtained by sequentially excluding each stock's data set and repeating the meta-analysis. Type C results should be used whenever the assessment input data overlap with the meta-analysis input data, avoiding the double use of data. We illustrate the impact of this reporting change on the results of a recent meta-analysis.
Escapement, harvest, and unknown loss of radio-tagged adult salmonids in the Columbia River  Snake River hydrosystem
Authors: Keefer Matthew L , Peery Christopher A , Daigle William R , Jepson Michael A , Lee Steven R , Boggs Charles T , Tolotti Kenneth R , Burke Brian J
Published: May 2005

Accurate estimates of escapement by adult anadromous salmonids are difficult, especially in large, multistock river systems. We used radiotelemetry and a fishery reward program to calculate escapement, harvest, and unaccounted for loss rates for 10 498 adult chinook salmon (Oncorhynchus tshawytscha) and 5324 steelhead (Oncorhynchus mykiss) during six return years in the Columbia River basin. Mean annual escapements to spawning sites, hatcheries, or the upper bounds of the monitored hydrosystem were 73.4% (springsummer chinook salmon), 61.3% (fall chinook salmon), and 62.6% (steelhead). Mean reported harvest rates were 8.7% (springsummer chinook), 22.0% (fall chinook), and 15.1% (steelhead) within the mainstem hydrosystem and 5.9%, 3.4%, and 5.7%, respectively, in lower hydrosystem tributaries. On average, 12%17% of each run had unknown fates in the mainstem hydrosystem. Escapement, harvest, and loss varied significantly between runs and years, within runs between known-origin subbasin stocks, and between interdam river reaches. Multiyear quantitative assessments like this can reduce uncertainty, clarify inter- and intra-annual variability, and help managers better evaluate fisheries, identify conservation priorities, and help protect evolutionarily significant populations.
Are characteristics of introduced salmonid fishes biased by propagule pressure?
Authors: Colautti Robert I
Published: May 2005

Many recent studies of nonindigenous species (NIS) have used life history and morphological characteristics of invaders to either (i) build statistical models that predict new invaders or (ii) test ecological and evolutionary hypotheses. However, species characteristics may be confounded if NIS are transported or introduced nonrandomly with respect to the chosen contrast group, which typically consists of native or globally available species. For example, deliberately introduced NIS are often chosen according to economic rather than ecological factors. Here, I use stocking records of salmonid species introduced into Nevada, USA, to test for propagule biases within this system. I find that established salmonids are introduced significantly more times, and in greater numbers, than are those that fail and that species chosen for introduction are a nonrandom sample of the global salmonid species pool. Statistical differences among characteristics of salmonid species that established, those that were introduced, and those from the global source pool suggest that maximum reported size and weight as well as latitudinal range and midlatitude all represent propagule-biased characteristics of salmonids introduced into Nevada. These results highlight the need for caution when using characteristics of invaders to develop statistical models or to test hypotheses relevant to ecology and evolution.
Fisheries-induced adaptive change in reproductive investment in North Sea plaice (Pleuronectes platessa)?
Authors: Rijnsdorp A D , Grift R E , Kraak S BM
Published: May 2005

Life history theory predicts that fishing may select for increased reproductive investment. A model of the reaction norm for reproductive investment in a capital breeder was developed to disentangle changes in reproductive investment from changes in growth rate in North Sea plaice (Pleuronectes platessa). Trends in reproductive investment since 1960 were estimated as (i) the decrease in body weight of mature males and females between the start and end of the spawning period, (ii) the difference in weight of ripe and spent females, and (iii) the ovary weight of prespawning females. These estimates were related to somatic growth estimated by back-calculation of otoliths and temperature. The ovary weight and weight loss of females that had just started and just finished spawning did not reveal any trends. There was a significant increase in weight loss over the spawning season in both sexes, but much of this increase was likely due to changes in environmental conditions. Evidence for a fisheries-induced change in reproductive investment from our analyses thus remained inconclusive. However, fecundity and ovary-weight data from previous studies tentatively suggest that an increase in reproductive investment occurred between the late 1940s and the 1960s. Such an increase is consistent with a fisheries-induced evolutionary change.
Life history strategies, population regulation, and implications for fisheries management
Authors: Winemiller Kirk O
Published: May 2005

Life history theories attempt to explain the evolution of organism traits as adaptations to environmental variation. A model involving three primary life history strategies (endpoints on a triangular surface) describes general patterns of variation more comprehensively than schemes that examine single traits or merely contrast fast versus slow life histories. It provides a general means to predict a priori the types of populations with high or low demographic resilience, production potential, and conformity to density-dependent regulation. Periodic (long-lived, high fecundity, high recruitment variation) and opportunistic (small, short-lived, high reproductive effort, high demographic resilience) strategies should conform poorly to models that assume density-dependent recruitment. Periodic-type species reveal greatest recruitment variation and compensatory reserve, but with poor conformity to stockrecruitment models. Equilibrium-type populations (low fecundity, large egg size, parental care) should conform better to assumptions of density-dependent recruitment, but have lower demographic resilience. The model's predictions are explored relative to sustainable harvest, endangered species conservation, supplemental stocking, and transferability of ecological indices. When detailed information is lacking, species ordination according to the triangular model provides qualitative guidance for management and development of more detailed predictive models.
Integrating the effects of fish exploitation and interspecific competition into current life history theories: an example with lacustrine brook trout (Salvelinus fontinalis) populations
Authors: Magnan Pierre , Proulx Raphaël , Plante Michel
Published: May 2005

We used data from 17 populations of lacustrine brook trout (Salvelinus fontinalis) of the Canadian Shield, southern Quebec, to test whether early maturity (in males and females) and high reproductive effort (in females) are associated with increased (i) fish exploitation (sportfishing) and (ii) interspecific competition through their effects on growth and survival. The age at maturity of males and females was inversely related to the intensity of both fishing and interspecific competition. Fishing and interspecific competition affect the age at maturity through their effect on adult survival but not on growth, supporting predictions of life history models based on survival. In contrast, we did not find consistent effects of interspecific competition and fishing on the gonadosomatic index of females, which was directly related to survival (in all populations) and to the age at maturity (in exploited populations). These latter results are contrary to the predictions of life history models under the assumption that survival is directly related to growth rate. Our results suggest that reproductive effort and age at maturity are not dependent on growth when survival is independent of growth, as is the case in exploited and sympatric populations experiencing low adult survival but high growth.
Isolating the influence of growth rate on maturation patterns in the smallmouth bass (Micropterus dolomieu)
Authors: Dunlop Erin S , Shuter Brian J , Ridgway Mark S
Published: May 2005

In this study, we examine the divergence in growth and maturation between two populations of smallmouth bass (Micropterus dolomieu) introduced from a common source a century ago. To determine if the divergence in maturation is simply a plastic response to differences in growth rate, we use a new approach to estimate and then compare the probabilistic maturation reaction norms (PMRNs) for each population. The PMRNs for 5-year-old males are similar in the two populations, suggesting that the observed divergence in maturation is largely a plastic response to growth rate differences. For one population, we document the time course of maturation changes for the 60-year period from 1937 through 1990; while the mean length at maturation for 5-year-old males exhibits a steady downward trend (beginning at 31 cm and ending at 26 cm), their PMRNs vary over a much narrower range (2527 cm) and do not exhibit a consistent temporal trend. These observations are consistent with the hypothesis that most of the observed change in maturation since introduction is a product of phenotypic plasticity, driven by environmentally based differences in growth rate. Our study provides an instructive example of how the PMRN approach can be used to isolate the role of growth rate variation in generating life history differences.