bluuebunny/crossref_metadata_2025_split huggingface dataset:
Does competitive divergence occur if assortative mating is costly?
Authors: Schneider K. A. , Bürger R. 
Published: October 2005

Abstract
Most models of sympatric speciation have assumed that assortative mating has no costs. A few studies, however, have shown that the costs for being choosy can prevent such speciation. Here, we investigate the role of the strength of assortment and of the costs for being choosy for a simple genetic model of a single (‘magic’) trait that mediates both intraspecific competition for a continuum of resources and assortative mating, which is induced by choosy females who preferentially mate with males of similar phenotype. Choosiness may be costly if it is difficult to find a mating partner. Such magic trait models are considered to be most conducive of sympatric speciation. We consider a sexually reproducing population of haploid individuals that is density regulated. The trait is determined by a single locus with multiple alleles. The strength of stabilizing selection (caused by a unimodal resource distribution), the strength of competition, the degree of assortment and the costs for being choosy are independent parameters. We investigate analytically and numerically how these parameters determine the equilibrium and stability structure. In particular, we identify conditions under which no polymorphism at all is maintained as well as conditions under which strong competitive divergence occurs, or the population even splits into two reproductively isolated classes of highly diverse phenotypes. If costs are absent or moderate, genetic variability tends to be minimized at intermediate strengths of assortment, and reproductively isolated classes of phenotypes are a likely result of evolution only for intermediate or strong competition and for very strong assortment. The likelihood of divergence depends relatively weakly on the costs as long as they are not high. With high costs, however, increasingly strong assortment rapidly depletes all genetic variation, and strong competitive divergence is prevented.
Coevolution of male and female reproductive traits in a simultaneously hermaphroditic land snail
Authors: Beese K. , Beier K. , Baur B. 
Published: October 2005

Abstract
Inter- and intraspecific studies in gonochoristic animals reveal a covariation between sperm characteristics and the size of the female reproductive tract, indicating a rapid evolutionary divergence, which is consistent with the theory of post-copulatory sexual selection. Simultaneous hermaphrodites differ from species with separate sexes (gonochorists) in that they possess both functional male and female reproductive organs at the same time. We investigated whether in hermaphroditic animals intraspecific variation in reproductive traits results from divergent coevolution, by quantifying the variation in male and female traits among six natural populations of the snail Arianta arbustorum and examining the covariation in interacting traits. There was a significant among-population variation in spermatophore volume, number of sperm transferred and sperm length, as well as in volume of the sperm storage organ (spermatheca) and number of tubules, but not in spermatheca length. We found a positive association between sperm number transferred and spermatheca volume. This result suggests that the same post-copulatory mechanisms as in gonochorists drive the correlated evolution of reproductive characters in hermaphrodites.
Cardiac tamponade associated with a peripheral vein central venous catheter
Authors: COLOMINA MARÍA J. , GODET CARMEN , PELLISÉ FERRAN , GONZÁLEZ‐P MIGUEL ÁNGEL , BAGÓ JOAN , VILLANUEVA CARLOS 
Published: October 2005

SummaryWe present a case of cardiac tamponade associated with placement of a central venous catheter (CVC) via a peripheral vein in a 14‐year‐old girl with idiopathic scoliosis undergoing corrective surgery. A number of complications have been described in association with CVC misplacement. Sporadic cases of cardiac tamponade from this have been reported, but the actual incidence is unknown. Death from cardiac tamponade attributed to CVCs ranges from 65 to 100%. In our patient, cannulation of the pericardiophrenic vein was probably the cause of cardiac tamponade, based on radiological evidence that the initial location of the catheter was near the right atrium and possibly at the outlet of the pericardiophrenic vein. The catheter could have advanced into the vein and then to the pericardial sac with postural changes. The acute clinical course of cardiac tamponade in our patient had potentially lethal hemodynamic repercussions. The main diagnostic test for this condition is echocardiography and the only effective treatment is drainage of the pericardial effusion. Echocardiography should be performed before pericardiocentesis except in life‐threatening situations or high clinical suspicion. Although they are rare, it is important to be aware of the potential for CVC complications.
Anesthesia in a patient with chromosome 11;22 translocation: a case report and literature review
Authors: DRUM ELIZABETH T. , HERLICH ANDREW , LEVINE BRUCE , MAYHEW JAMES F. 
Published: October 2005

SummaryChromosome 11;22 translocation is a rare genetic condition, which results in characteristic features some of which may present problems when these children require surgery and anesthesia. We describe a child with this chromosomal variant who presented for surgery and anesthesia. The case report and review of the literature is presented here.
The safe use of intraoperative transesophageal echocardiography in the management of total anomalous pulmonary venous connection in newborns and infants: a case series
Authors: CHANG YA‐YING , CHANG CHUNG‐I , WANG MING‐JIH , LIN SU‐MAN , CHEN YIH‐SHARNG , TSAI SHEN‐KOU , LUE HONG‐CHI 
Published: October 2005

SummaryBackground : Intraoperative transesophageal echocardiography (TEE) is useful in evaluating the repair of lesions in patients with congenital heart disease. But the use of TEE in infants with total anomalous pulmonary venous connection (TAPVC) remains unclear. We reviewed the safety and efficacy of intraoperative TEE during TAPVC repair.Methods : Twenty‐eight consecutive 1 day to 7 month‐old infants with TAPVC (14 supracardiac, six intracardiac and eight infracardiac type) had surgical repair with intraoperative TEE monitoring.Results : Four patients received immediate surgical revision after primary surgery for residual anastomotic stenosis diagnosed by TEE. In addition, two unsuspected ventricular septal defects and three persistent ductus arteriosus were detected before surgery. Eight infants (29%) had hypotension and hypoxemia associated with TEE probe insertion before surgery, but this hemodynamic disturbance returned to baseline value after withdrawing the TEE probe from the esophagus. However, these eight patients had uneventful TEE probe insertion following sternotomy. The mechanism was probably because of the reduction of intrathoracic pressure when the chest was opened.Conclusions : TEE probe insertion in TAPVC patients may pose a potential risk of compression of pulmonary venous confluence resulting in hemodynamic instability. Therefore, we suggest that the use of TEE in such TAPVC patients appears to be safer after sternotomy.
Submental intubation for cancrum oris: a case report
Authors: EIPE NAVEEN , NEUHOEFER EVA‐SABINE , ROSEE GABRIELE LA , CHOUDHRIE RAJIV , SAMMAN NABIL , KREUSCH THOMAS 
Published: October 2005

SummaryCancrum oris (Noma) is a devastating gangrenous disease that leads to severe tissue destruction in the face. We describe the anesthetic management of a 12‐year‐old girl with cancrum oris sequelae in a Rural Secondary level Hospital in Central India (Padhar Hospital). She presented with a large defect in her upper lip on the left side that extended into the columella and the floor of the left nostril. She was scheduled to undergo reconstructive surgery and the surgeons planned to use an Abbé flap based on the lower lip. For this, access to both the mouth and the nose was required. We considered a tracheostomy but decided to attempt the submental route for orotracheal intubation. Following intravenous induction the patient's trachea was intubated with a cuffed oral tracheal tube. This was passed through the submental incision and then reconnected. The surgery proceeded uneventfully and the patient was extubated before transfer. She made a satisfactory recovery and the submental scar healed without complication or scarring. We describe briefly the features of cancrum oris and review the technique of submental intubation (described in adults with midfacial trauma). The use of submental intubation in children and for cancrum oris sequelae has not been previously reported.
Protracted pain following partial splenic embolization in an adolescent female with hypersplenism
Authors: GANESH ARJUNAN , ROSE JOHN B. , MAXWELL LYNNE G. 
Published: October 2005

SummaryA 17‐year‐old female with massive splenomegaly underwent partial splenic embolization (PSE) for hypersplenism. The postoperative course was characterized by recurrent painful splenic infarctions requiring hydromorphone PCA for an extended period resulting in an unanticipated, prolonged hospital stay. Massive splenomegaly treated with PSE may require an extended hospital stay to achieve pain control. Such patients may subsequently require transition to enteral opioids and weaning.
Arrhythmias associated with respiratory syncytial virus infection
Authors: PLAYFOR STEPHEN D. , KHADER ABDUL 
Published: October 2005

SummaryA 7‐week‐old infant with respiratory syncytial virus infection abruptly developed complex cardiac arrhythmias in association with a low serum magnesium level. The arrhythmias were successfully treated with a single intravenous infusion of magnesium sulfate. The child was subsequently found to have a significant atrial septal defect.
Utility of ultrasound‐guided central venous cannulation in pediatric surgical patients: a clinical series
Authors: LEYVI GALINA , TAYLOR DAVID G , REITH ELIZABETH , WASNICK JOHN D. 
Published: October 2005

SummaryBackground:  Central venous cannulation can be particularly difficult in pediatric patients. Central line placement is associated with many well‐known complications. While ultrasound‐guided techniques are well established, the majority of central venous catheters are placed using landmark guidance. This retrospective study compares the safety and efficacy of ultrasound guidance vs landmark guidance in central venous cannulation of pediatric cardiac surgery patients.Methods:  The medical records of 149 pediatric patients undergoing cardiac surgery over 3‐year period were reviewed. Patients were classified into two cohorts based on whether central venous cannulation of the internal jugular vein was performed by ultrasound or landmark guidance. Overall success and traumatic complication rates were compared between the two groups. Additionally, comparisons between the groups were made to determine if patient size or age affected the success rate of either approach in different manner.Results:  Patients in the ultrasound‐guided (n = 47) and the landmark‐guided (n = 102) groups were similar with respect to age, weight, and surgical procedure for which central venous access was indicated. The overall success rate for cannulation of the internal jugular vein was 91.5% in the ultrasound‐guided group and 72.5% in the landmark‐guided group (P = 0.010). But in the subgroup of children under 1 year of age, success rate was 77.8% in ultrasound group and 60.9% in landmark group (P = 0.44); in children under 10 kg in weight, success rate was 80% in ultrasound group and 56.7% in landmark group (P = 0.19). There were no significant differences in the rate of traumatic complications between the two methods.Conclusions:  The overall success of internal jugular vein cannulation for pediatric cardiac surgery is significantly improved with the use of ultrasound guidance, without a significant difference in traumatic complications. However, mostly children above 1 year of age or 10 kg of weight experience advantages of ultrasound technique.
Can continuous low current electrical stimulation distinguish insulated needle position in the epidural and intrathecal spaces in pediatric patients?
Authors: TSUI BAN C.H. , WAGNER ALESE M. , CUNNINGHAM KIRSTEN , PERRY SHIRLEY , DESAI SUNIL , SEAL ROBERT 
Published: October 2005

SummaryBackground : Muscle twitches elicited with electrical stimulation (6–17 mA) during epidural insertion indicate correct epidural needle placement while muscle twitches at a lower current (<1 mA) may indicate intrathecal needle placement. This study examined whether applying continuous electrical stimulation at 6 mA could indicate needle entry into the epidural space without inadvertently penetrating the intrathecal space.Methods : After institutional review board (IRB) approval, 10 pediatric patients scheduled for lumbar puncture were studied. Following sedation with propofol, an insulated 24‐gauge Pajunck unipolar needle was inserted through an 18‐gauge introducer needle placed at the L4‐5 interspace. The needle was first connected to a nerve stimulator (6 mA) and advanced. At the first sign of muscle twitching, needle advancement was stopped and the threshold current for motor activity was determined. The current was then turned off, the stylet was removed and the needle checked for cerebrospinal fluid (CSF). If CSF was not present, the needle was advanced into the intrathecal space (as confirmed by the presence of CSF). Ten pediatric patients (ASA II or III) aged 7.8 ± 4.3 years (2.8–16.0 years) were studied.Results : All patients had two distinguishable threshold currents as the needle advanced. The mean threshold current to elicit muscle twitch in the presumed epidural space was 3.84 ± 0.99 mA. CSF was not present in any of the patients at this location. The mean threshold current in the intrathecal space was 0.77 ± 0.32 mA. The average estimated distance from the first threshold location to the intrathecal space was 3 mm. All muscle twitches were at the L3‐5 myotomes. Nine muscle twitches were unilateral and one was bilateral.Conclusions : Monitoring with an insulated needle with electrical stimulation at 6 mA may prevent unintentional placement of epidural needles into the intrathecal space.
Predator diversity and the functioning of ecosystems: the role of intraguild predation in dampening trophic cascades
Authors: Finke Deborah L. , Denno Robert F. 
Published: October 2005

AbstractSingle trophic‐level studies of the relationship between biodiversity and ecosystem functioning highlight the importance of mechanisms such as resource partitioning, facilitation, and sampling effect. In a multi‐trophic context, trophic interactions such as intraguild predation may also be an important mediator of this relationship. Using a salt‐marsh food web, we investigated the interactive effects of predator species richness (one to three species) and trophic composition (strict predators, intraguild predators, or a mixture of the two) on ecosystem functions such as prey suppression and primary production via trophic cascades. We found that the trophic composition of the predator assemblage determined the impact of increasing predator species richness on the occurrence of trophic cascades. In addition, increasing the proportion of intraguild predator species present diminished herbivore suppression and reduced primary productivity. Therefore, trophic composition of the predator assemblage can play an important role in determining the nature of the relationship between predator diversity and ecosystem function.
The tri‐trophic niche concept and adaptive radiation of phytophagous insects
Authors: Singer Michael S. , Stireman John O. 
Published: October 2005

AbstractA conceptual divide exists between ecological and evolutionary approaches to understanding adaptive radiation, although the phenomenon is inherently both ecological and evolutionary. This divide is evident in studies of phytophagous insects, a highly diverse group that has been frequently investigated with the implicit or explicit goal of understanding its diversity. Whereas ecological studies of phytophagous insects increasingly recognize the importance of tri‐trophic interactions as determinants of niche dimensions such as host‐plant associations, evolutionary studies typically neglect the third trophic level. Here we attempt to reconcile ecological and evolutionary approaches through the concept of the ecological niche. We specifically present a tri‐trophic niche concept as a foil to the traditional bi‐trophic niche concept for phytophagous insects. We argue that these niche concepts have different implications for understanding herbivore community structure, population divergence, and evolutionary diversification. To this end, we offer contrasting empirical predictions of bi‐ and tri‐trophic niche concepts for patterns of community structure, the process of population divergence, and patterns of evolutionary diversification of phytophagous insects.
Non‐neutral patterns of species abundance in grassland communities
Authors: Stanley Harpole W. , Tilman David 
Published: October 2005

AbstractAlthough the distribution of plant species abundance in a Minnesota grassland was consistent with neutral theory, niche but not neutral mechanisms were supported by the ability of species traits to predict species abundances in three experimental grassland communities. In particular, data from 27 species grown in monoculture showed that species differed in a trait,R*, which is the level to which each species reduced the concentration of soil nitrate, the limiting soil nutrient and which is predicted to be inversely associated with competitive ability for nitrogen (N). In these N‐limited habitats, species abundance ranks correlated with their predicted competitive ranks: lowR* species, on average dominated. These correlations were significantly different than expected for neutral theory, which assumes the exchangeability of species traits. Additionally, we found that changes in relative abundance after environmental change (N‐addition or disturbance) were not neutral but also were significantly associated withR*.
Effect of early addition of rosiglitazone to sulphonylurea therapy in older type 2 diabetes patients (>60 years): the Rosiglitazone Early vs. SULphonylurea Titration (RESULT) study
Authors: Rosenstock J. , Goldstein B. J. , Vinik A. I. , O'Neill M. Colleen , Porter L. E. , Heise M. A. , Kravitz B. , Dirani R. G. , Freed M. I. ,   and the RESULT Study Group
Published: October 2005

Aim:  To compare the efficacy, safety and tolerability of adding rosiglitazone (RSG) vs. sulphonylurea (SU) dose escalation in older type 2 diabetes mellitus (T2DM) patients inadequately controlled on SU therapy.Methods:  A total of 227 T2DM patients from 48 centres in the USA and Canada, aged ≥60 years, were randomized to receive RSG (4 mg) or placebo once daily in combination with glipizide 10 mg twice daily for 2 years in a double‐blind, parallel‐group study. Previous SU monotherapy was ¼ to ½ maximum recommended dose for ≥2 months prior to screening with fasting plasma glucose (FPG) ≥7.0 and ≤13.9 mmol/l. Treatment options were individualized, and escalation of study medication was specifically defined.Results:  Disease progression (time to reach confirmed FPG ≥10 mmol/l while on maximum doses of both glipizide and study medication or placebo) was reported in 28.7% of patients uptitrating SU plus placebo compared with only 2.0% taking RSG and SU combination (p < 0.0001). RSG + SU significantly decreased HbA1c, FPG, insulin resistance, plasma free fatty acids and medical care utilization and improved treatment satisfaction compared with uptitrated SU.Conclusions:  Addition of RSG to SU in older T2DM patients significantly improved glycaemic control and reduced disease progression compared with uptitrated SU alone but without increasing hypoglycaemia. These benefits were associated with increased patient treatment satisfaction and reduced medical care utilization with regards to emergency room visits and length of hospitalization. Early addition of RSG is an effective treatment option for older T2DM patients inadequately controlled on submaximal SU monotherapy.
Binomial basis for linear information dynamics: real options, dividends and the valuation of equity
Authors: Ashton David , Lim Chen , Tippett Mark , Wright Brian 
Published: October 2005

AbstractAnalytical research has confirmed that real options give rise to the kind of nonlinearities observed in practice between equity prices and the figures appearing on corporate financial statements. We develop these real option values in terms of a quasi ‘supply‐side’ model of linear information dynamics based on simple discrete time binomial filtration processes. Our analysis shows that the linear models that pervade the empirical (and analytical) work of the area, will almost certainly suffer from an omitted variables problem. Parameter estimation will then be inconsistent and inefficient.
Undergraduate performance in accounting and business‐based information technology
Authors: Heales Jon 
Published: October 2005

AbstractThe pervasiveness of information systems (IS) in organizations mandates the need for high levels of IS skills. In recognition, professional bodies impose IS course requirements for accreditation. For both students and employers, performance in IS courses has become important. The tertiary entrance overall performance score accounted for 19.7 per cent of the variance in students' passing grades. Thereafter, proficiency in office automation software and programming accounted for 1.5 and 0.8 per cent of the variance, respectively. Students living in a stable, family home‐based environment performed better and it is likely that this environment underpinned other factors affecting performance.
High‐lysine corn produced by the combination of enhanced lysine biosynthesis and reduced zein accumulation
Authors: Huang Shihshieh , Kruger Diane E. , Frizzi Alessandra , D’Ordine Robert L. , Florida Cheryl A. , Adams Whitney R. , Brown Wayne E. , Luethy Michael H. 
Published: October 2005

SummaryCorn is one of the major crops in the world, but its low lysine content is often problematic for animal consumption. While exogenous lysine supplementation is still the most common solution for today's feed corn, high‐lysine corn has been developed through genetic research and biotechnology. Reducing the lysine‐poor seed storage proteins, zeins, or expressing a deregulated lysine biosynthetic enzyme, CordapA, has shown increased total lysine or free lysine content in the grains of modified corn plants, respectively. Here, by combining these two approaches through genetic crosses, the total lysine content has more than doubled in F1 progeny. We also observe a synergy between the transgenic zein reduction and the enhanced lysine biosynthesis by CordapA expression. The zein reduction plants are found to accumulate higher levels of aspartate, asparagine and glutamate, and therefore, provide excess precursors for the enhanced lysine biosynthesis.