bluuebunny/crossref_metadata_2025 huggingface dataset:
Morningness‐Eveningness Preferences of Emergency Medicine Residents Are Skewed toward Eveningness
Authors: Steele Mark T. , McNamara Robert M. , Smith‐Coggins Rebecca , Watson William A.
Published: September 2008

Objective: To determine the morningness‐eveningness (ME) distribution of emergency medicine (EM) residents.

Method: A voluntary, modified ME questionnaire was administered to all EM residents in the United States at the time of the 1995 American Board of Emergency Medicine's annual In‐Training Examination. Results: Seventy‐eight percent (2,047/2,614) of the surveys were returned. ME scores ranged from 24 to 76, with a median score of 49 (interquartile range 44, 56). The scores were distributed differently from those of the normal population (p < 0.001), being skewed toward eveningness. There was a correlation (r = 0.13, p < 0.0001) between resident age and ME score, with older residents being more morning‐oriented. Males were more morning‐oriented than females (p = 0.005), and respondents with children living at home also were significantly more morning‐oriented (p < 0.001). Stepwise logistic regression showed that the influence of age, gender, and children was cumulative (r = 0.19) but accounted for only 4% of the observed variability. Conclusion: EM residents are distributed differently from the normal population in terms of their ME preferences, tending slightly toward eveningness. The importance of this distribution in EM residents is unknown. A longitudinal follow‐up of this cohort may help to determine the association of ME preference with overall practice satisfaction, tolerance of shift work, and career longevity.

The authors thank Barbara McClusky and Jayna Ross for data entry and management, Linda L. Smith for manuscript preparation, James C. Impara, PhD, and Ted Carter, Buros Institute of Mental Measurements, University of Nebraska‐Lincoln, for their statistical assistance, and the staff at SAEM (particularly Mary Ann Schropp). This study was performed under the authorization of the Inservice Examination Survey Task Force of SAEM.
Bilious Vomiting in a 9‐month‐old Infant
Authors: Brennan Daniel F.
Published: September 2008

A case of bilious vomiting in a 9‐month‐old male is reported. The differential diagnosis of infantile bilious vomiting is reviewed, and appropriate diagnostic studies are discussed. The child was found to have intussusception. The common manifestation of this pediatric surgical emergency may vary considerably from classic descriptions. Bilious emesis in infants must be considered a surgical emergency until proven otherwise; intussusception may manifest as bilious vomiting only.
Structured Emergency Medicine Board Review and Resident In‐service Examination Scores
Authors: Gillen James P.
Published: September 2008

Objective: To determine whether the institution of a structured board review program is associated with improved in‐service examination scores by residents at an emergency medicine (EM) residency program. Methods: A retrospective, historical control analysis of the association of a board review program and in‐service examination scores at one EM residency program was performed. A structured board review consisting of monthly reading assignments in “classic” EM textbooks followed by a graded multiple‐choice written examination was instituted in 1987. Percentile scores on the American Board of Emergency Medicine (ABEM) in‐service examination before (1985 — 1986) and after (1987–1994) initiation of the board review process were compared by resident level (EM‐1, 2, or 3).

Results: The EM‐1 mean percentile score before board review was 50.7 and rose to 68.9 after the institution of the board review program (p = 0.039). Mean EM‐2 scores (66.8 vs 65.4) and EM‐3 scores (74.4 vs 67.4) decreased slightly; these decreases were not statistically significant. Due to the large increase in EM‐1 scores, the mean scores for the total program increased slightly (63.4 vs 67.4; p = NS).

Conclusion: In this study, EM‐1 in‐service scores improved in association with the institution of a structured board review program. This formalized didactic program may increase the knowledge base and test performance of EM‐1 residents. A favorable effect on EM‐2 and EM‐3 resident scores was not seen.
Workforce Projections for Emergency Medicine: How Many Emergency Physicians Does the United States Need?
Authors: Holliman C. James , Wuerz Richard C. , Chapman Dane M. , Hirshberg Alan J.
Published: September 2008

Objective: To mathematically model the supply of and demand for emergency physicians (EPs) under different workforce conditions.

Methods: A computer spreadsheet model was used to project annual EP workforce supply and demand through the year 2035. The mathematical equations used were: supply = number of EPs at the beginning of the year plus annual residency graduates minus annual attrition; demand = 5 full‐time equivalent positions/ED X the number of hospital EDs. The demand was empirically varied to account for ED census variation, administrative and teaching responsibilities, and the availability of physician extenders. A variety of possible scenarios were tested. These projections make the assumption that emergency medicine (EM) residency graduates will preferentially fill clinical positions currently filled by EPs without EM board certification.

Results: Under most of the scenarios tested, there will be a large deficit of EM board‐certified EPs well into the next century. Even in scenarios involving a decreasing “demand” for EPs (e.g., in the setting of hospital closures or the training of physician extenders), a significant deficit will remain for at least several decades. Conclusions: The number of EM residency positions should not be decreased during any restructuring of the U.S. health care system. EM is likely to remain a specialty in which the supply of board‐certified EPs will not meet the demand, even at present levels of EM residency output, for the next several decades.
Derivation and Validation of a Methodology for Tracking Academic Stature of Medical Schools
Authors: Gallagher E. John , Henneman Philip L. , Schropp Mary Ann , Force For the Task
Published: September 2008

Objective: To derive and validate a methodology for academic ranking of allopathic medical schools in order to track the development of emergency medicine (EM) at academic medical centers.

Methods: A methodology for institutional ranking according to NIH research grant funding was derived by using a well‐known multiaxial ordinal ranking of all Liaison Committee on Medical Education (LCME)‐accredited allopathic schools in 1990–91 as the criterion standard. This methodology was validated against the same annually updated criterion standard in 1995–96. Both ranking schemes were first stratified by quartile, then aggregated pairwise by contiguous quartiles to develop a 3 × 3 concordance matrix.

Results: Ranking by NIH grant funding produced concordance between all 126 schools in the derivation set and 123/124 schools in the validation set.

Conclusion: NIH research grant funding may be used as a valid methodology for broad categorization of allopathic medical school academic rank. This strategy should therefore serve as a suitable means of following the development of academic EM over time.

This project was supported by a grant from SAEM.
Changing Status of Academic Emergency Medicine (1991–1996)
Authors: Gallagher E. John , Schropp Mary Ann , Henneman Philip L. , Force For The Task
Published: September 2008

Objective: An SAEM national task force previously concluded that academic departments and residencies in emergency medicine (EM) had preferentially developed outside of the academic mainstream. This study was designed to determine whether EM has made significant inroads into academic medical centers over the past 5 years. Methods: The baseline data set (7/1/91) contained all 126 Liaison Committee on Medical Education (LCME)‐accredited schools, and all 87 Residency Review Committee (RRC)‐accredited EM residencies. The comparison data set (7/1/96) contained all 124 LCME‐accredited schools, and all 114 RRC‐accredited EM residencies. The 1991–96 increment in academic departments and university‐hospital residencies was examined in the aggregate, then stratified by medical schools grouped into quartiles and contiguous quartiles, according to academic ranking. A‐priori and post‐hoc comparisons were expressed with 95% and 99% confidence intervals (CIs), respectively.

Results: Over the past 5 years, the proportion of academic departments of EM increased by 23%, from 18% to 41% of all LCME‐accredited schools (95% CI 12% to 34%). The largest increase (58%; 99% CI 40% to 77%) occurred among those schools academically ranked above the median. The proportion of EM residencies at university hospitals increased by 17%, from 40% to 57% (95% CI 5% to 30%). Again, the largest increase (25%; 99% CI 3% to 47%) occurred at university hospitals affiliated with schools academically ranked above the median.

Conclusion: EM has made substantial inroads into academic medical centers over the past 5 years. This is reflected in quantitatively and statistically significant increases in academic departments and university‐hospital residency programs, both occurring largely within institutions whose academic rankings place them among the upper half of all LCME‐accredited medical schools.
Rural Hospital Transfer Patterns before and after Implementation of a Statewide Trauma System
Authors: Mann N. Clay , Hedges Jerris R. , Mullins Richard J. , Helfand Mark , Worrall William , Zechnich Andrew D. , Group For The OHSU Rural Trauma Research
Published: September 2008

Objective: To evaluate trauma transfer practices in rural Oregon before and after implementation of a statewide trauma system.

Methods: A pre‐ vs post‐system implementation (historical control) analysis of trauma transfer practices was performed using a sample of rural ED trauma patients from 4 Level‐3 and 5 Level‐4 trauma hospitals. Medical records of patients with specific index injury diagnoses in 4 anatomic regions (head, chest, liver/ spleen, and femur/open‐tibia) were reviewed for a 3‐year period before statewide trauma system implementation and 3 years after hospital trauma designation.

Results: Of 1,057 patients entered into the database, 532 were evaluated during the pre‐system period and 525 were evaluated during the post‐system period. Overall, 47% had head injuries, 34% had chest injuries, 23% had femur/open‐tibia injuries, and 12% had spleen/liver injuries. There were 142 (13%) patients with an injury in >1 index area. After trauma system implementation, there was a significant increase in the proportion of ED trauma patients transferred from Level‐4 trauma hospitals (32% vs 68%, p < 0.001), with a corresponding decrease in the number of hospital admissions to these facilities (63% to 29%, p < 0.001). Significant increases in the proportion transferred from Level‐4 trauma hospital EDs were noted for all index injury categories (p < 0.001). Trauma patients presenting to Level‐4 EDs were significantly more likely to be transferred to Level‐2 facilities (66% vs 82%, p = 0.030), while patients at Level‐3 facilities were significantly more likely to be transferred to Level‐1 centers (2% vs 14%, p = 0.002) following trauma system implementation. Multiple logistic regression modeling indicated that implementation of the statewide trauma system was an independent predictor of rural trauma patient transfer from Level‐4 hospitals, while transfers from Level‐3 facilities were dependent on type of injury.

Conclusion: Implementation of the Oregon statewide trauma system was associated with a redistribution of rural trauma patients to trauma hospitals with greater therapeutic resources.
The Urban Epidemiology of Recurrent Injury: Beyond Age, Race, and Gender Stereotypes
Authors: Madden Cynthia , Garrett Joanne M. , Cole Thomas B. , Runge Jeffrey W. , Porter Carol Q.
Published: September 2008

Objectives: To profile all patients presenting to an urban ED with any injury, and to determine whether the rate of subsequent injury treated in the ED varied by demographic and E‐code (external mechanism of injury) category. The hypothesis that young black males were disproportionately at risk for re‐injury was addressed.

Methods: A cohort of consecutive patients presenting to an urban ED with any injury between January 1, 1991, and November 31, 1992, were followed prospectively for 1 year from their index visit dates. Any repeat ED visits due to injury were sought. The mean number of injury visits per year (the total number of ED injury visits for each patient divided by 1 year) was computed for the overall population and by race, age, gender, and E‐code.

Results: The sample consisted of 34,378 patients who made 44,813 visits to the ED for injury. Of these patients, 22% had a repeat injury in 1 year, with a cohort mean of 1.30 injury visits per year. This mean did not vary appreciably by race (black 1.33, white 1.27), age (1–17 yr, 1.21; 18–24 yr, 1.32; 25–64 yr, 1.34; >65 yr, 1.23), gender (males 1.33, females 1.27), or E‐code category. Having a prior injury visit in the preceding year was the best predictor of future injury (mean repeat visit rate = 2.08).

Conclusions: When examining patients presenting with any injury to an urban ED, the mean numbers of injury visits are remarkably similar across demographic and E‐code categories. Although there are factors that place patients at risk for recurrent injury, those factors are not demographic—all patients presenting to an ED with injury should be considered at risk for re‐injury.
The Significance of Out‐of‐hospital Hypotension in Blunt Trauma Patients
Authors: Chan Lisa , Bartfield Joel M. , Reilly Kevin M.
Published: September 2008

Objective: To determine the significance of a low out‐of‐hospital systolic blood pressure (SBP) reading in blunt trauma patients who have a normal SBP upon ED arrival.

Methods: A retrospective case‐control study compared admitted blunt trauma patients who were hypotensive (SBP ≤90 mm Hg) in the field and normotensive in the ED (group 1) with those who were normotensive both in the field and in the ED (group 2). The groups were compared for mortality, intensive care unit (ICU) admission, injury severity scale (ISS) score, need for transfusion in the ED, incidence of intra‐abdominal injury, and incidence of pelvic or femur fracture.

Results: Each group consisted of 52 patients. The groups were similar with respect to age, gender, and initial ED SBP. The group 1 patients had a higher mortality (10 vs 1, p = 0.008), a higher number of ICU admissions (28 vs 12, p = 0.001), more pelvic or femur fractures (16 vs 7, p = 0.03), and a higher ISS score (19.0 vs 10.5, p = 0.01). Although not significant, group 1 also had higher incidences of intra‐abdominal injury (10 vs 3, p = 0.07) and transfusion (8 vs 2, p = 0.09).

Conclusion: The injured patients who were hypotensive in the out‐of‐hospital setting but normotensive upon ED arrival were more severely injured and had more potential for blood loss than were the patients who were normotensive both in the out‐of‐hospital setting and in the ED. Out‐of‐hospital hypotension may be a clinical predictor of severe injury, even in the face of normal ED SBP. Prospective studies are indicated to validate this hypothesis.
The Impact of an Endotracheal Side Port on the Absorption of Lidocaine
Authors: Storrow Alan B. , Walthall John W. , Magoon Michael R. , Pascuzzi Thomas J. , Bifano Sandra L.
Published: September 2008

Objective: To compare lidocaine levels after administration through an IV line, a standard endotracheal (ET) tube, and an ET tube side port (ETSP) designed for medication administration.

Methods: A double‐blind, prospective, triple crossover canine study was performed. Seventeen anesthetized mongrel dogs were given standard doses of 2% lidocaine via IV (1.5 mg/kg), endotracheally through the main lumen (3 mg/kg diluted in 10 mL normal saline), and endotracheally through the modified side port (3 mg/ kg diluted in 10 mL normal saline). Arterial blood gases (ABGs) and plasma lidocaine levels were measured at time 0, 30 sec, 1 min, 5 min, 10 min, 20 min, 30 min, and 60 min. Mean lidocaine levels across time, comparing the 3 methods of administration, were analyzed with repeated‐measures analysis of variance. The main outcome was the comparison of mean ET and ETSP lidocaine levels at each time point using paired t‐tests. The attainment and duration of lidocaine levels considered therapeutic in cardiac arrest (1.4 μg/mL) were described. ABGs were measured at each point to describe trends in oxygenation.

Results: Mean lidocaine levels, comparing the 3 methods of administration, were significantly different at all time points except time 0. The ETSP levels were significantly lower than the ET main‐lumen levels at 30 sec, 1 min, 5 min, and 10 min. IV‐administered lidocaine attained quick therapeutic levels and revealed faster elimination. Lidocaine administered through the ET main lumen reached therapeutic levels more slowly, and maintained such levels longer. Lidocaine administered through the ETSP never reached therapeutic levels. Mean Po2s remained >340 torr throughout each method of administration.

Conclusion: This nonarrest canine model suggests that lidocaine levels achieved through an ETSP are lower than levels obtained with the same drug dose via an ET main lumen. Therapeutic lidocaine levels are obtainable by IV or ET main‐lumen routes, but not via this ETSP.
Use of the World Wide Web for Multisite Data Collection
Authors: Subramanian Ashok K. , McAfee Andrew T. , Getzinger Jim P.
Published: September 2008

As access to the Internet becomes increasingly available, research applications in medicine will increase. This paper describes the use of the Internet, and, more specifically, the World Wide Web (WWW), as a channel of communication between EDs throughout the world and investigators who are interested in facilitating the collection of data from multiple sites. Data entered into user‐friendly electronic surveys can be transmitted over the Internet to a database located at the site of the study, rendering geographic separation less of a barrier to the conduction of multisite studies. The electronic format of the data can enable real‐time statistical processing while data are stored using existing database technologies. In theory, automated processing of variables within such a database enables early identification of data trends. Methods of ensuring validity, security, and compliance are discussed.
Use of the Alveolar Dead Space Fraction (Vd/Vt) and Plasma D‐dimers to Exclude Acute Pulmonary Embolism in Ambulatory Patients
Authors: Kline Jefsrey A. , Meek Suzy , Boudrow Dawn , Warner Douglas , Colucciello Stephen
Published: September 2008

ABSTRACT

Objective: To evaluate the utility of a modified calculation of the alveolar dead space fraction (Vd/Vt), combined with plasma D‐dimers, to aid in the exclusion of acute pulmonary embolism (PE). Methods: A prospective comparison of screening modalities was performed in a metropolitan teaching ED. Ambulatory patients evaluated for PE underwent simultaneous end‐tidal CO2 and arterial blood gas determinations, as well as venous latex‐agglutination D‐dimer quantification. The modified Bohr equation was used to calculate Vd/Vt as an index of alveolar dead space. Acute PE was diagnosed or excluded using appropriate combinations of clinical suspicion, ventilation‐perfusion lung scanning, lower‐extremity venous Doppler ul‐trasonography, pulmonary angiography, and comprehensive follow‐up.

Results: Of 170 subjects studied, PE was confirmed (PE+) in 26 (15%) and excluded (PE‐) in 144 (85%). In the PE+ group, Vd/Vt was 0.31 ± 0.13 (mean ± SD), and in the PE‐ group, Vd/Vt was 0.06 ± 0.10 (p< 0.05, t‐test). Regarding false‐negative rates, Vd/Vt was normal (i.e., <0.2) in 3/26 PE+ patients and D‐dimer concentrations were normal (<0.5 μg/L) in 4/26 patients in the PE+ group. The combination of a normal Vd/Vt and D‐dimer concentration was 100% sensitive (95% CI = 88–100%) in excluding PE. False‐positive testing (either test positive) occurred in 49/14 subjects (specificity 65%, 95% CI = 52–73%). The age‐adjusted alveolar‐arterial O2 gradient was 33 ± 38 torr in the PE+ group vs 13 ± 37 torr in the PE— group (p = 0.11).

Conclusions: In ambulatory patients, the finding of Vd/Vt <0.2 and D‐dimers <0.5 μg/L lowers the probability of acute PE.
Selective Aortic Arch Perfusion Using Serial Infusions of Perflubron Emulsion
Authors: Manning James E. , Batson D. Neil , Gansman Thomas W. , JK Charles A. Murphy
Published: September 2008

Objective: To determine whether selective aortic arch perfusion (SAAP) using serial infusions of oxygenated perflubron emulsion combined with aortic epinephrine (AoE) administration is more effective than conventional therapy in treating cardiac arrest.

Methods: An experimental cardiac arrest model (10 min ventricular fibrillation and 2 min CPR) was used with 12 mixed‐breed canines, randomized into 2 groups: control (n = 6), CPR and IV epinephrine, 0.01 mgkg, at 12 rnin and then every 3 min; or AoE‐SAAP (n = 6), CPR and aortic epinephrine, 0.01 mgkg, at 12 rnin and then every 3 min, and serial SAAP with oxygenated 60% weightholume (w/v) perflubron emulsion as follows: 300 mL over 30 sec at 12 rnin as continuous SAAP without CPR; 150 mL over 20–30 sec at 15 min and 18 rnin as pulsed diastolic SAAP during CPR.

Results: AoE‐SAAP resulted in increased coronary perfusion pressure (CPP) and return of spontaneous circulation (ROSC) compared with control. CPR‐diastolic (release phase) CPP during pulsed diastolic SAAP was similar to or greater in magnitude than the CPP generated during the initial SAAP infusion without CPR. ROSC for control was 0/6 and for AoE‐SAAP was 416 (p < 0.05, Fisher's exact test). Time from initiation of CPR to ROSC with a sustained systolic aortic pressure >60 mm Hg was 8.0 ± 1.2 rnin in the 4 resuscitated AoE‐SAAP animals.

Conclusion: The combination of AoE with SAAP infusions of oxygenated perflubron emulsion was more effective than conventional resuscitation therapy. Pulsed diastolic SAAP is a promising method for performing SAAP.
The Clinical Features of Acute Pulmonary Embolism in Ambulatory Patients
Authors: Jr. Otto Susec , Boudrow Dawn , Kline Jeffrey A.
Published: September 2008

Objective: To identify clinical findings and predisposing conditions associated with acute pulmonary embolism (PE) in ambulatory patients being evaluated for PE.

Methods: A prospective observational study was conducted. A standardized multicomponent data collection form was administered to ambulatory subjects being evaluated for PE. The diagnosis of PE was confirmed or excluded using a combination of scintillation lung scanning, lower‐extremity venous Doppler ultrasonography, and selective use of pulmonary angiography.

Results: Data collection was completed for 170 subjects, with 26 (15%) cases of PE. Subjects with PE were significantly older (56 vs 41 years, 99% CI for difference of 15 years [6 to 25 years]), were more likely to report unexplained dyspnea (92% vs 69%. 99% CI for difference of 23% [7% to 40%]), and waited longer after symptom onset to seek medical evaluation (73 vs 36 hours, 99% CI for difference of 37 hours [I1 to 63 hours]). No difference was found for multiple variables commonly associated with PE. Assignment to risk categories was of limited diagnostic utility. For example, low‐risk assignment yielded 85% sensitivity, 20% specificity; high‐risk assignment: 31% sensitivity, 85% specificity, with diagnostic accuracy below 80% in both categories.

Conclusions: Among outpatients selected for evaluation for PE, further risk stratification demonstrated poor diagnostic utility. Clinical features alone cannot be used to differentiate presence or absence of PE in at‐risk ambulatory patients. Key words: pulmonary embolism; diagnosis; outpatient; risk; clinical features.
Ethical Issues of Cardiopulmonary Resuscitation: Current Practice among Emergency Physicians
Authors: Marco Catherine A. , Bessman Edward S. , Schoenfeld Charles N. , Kelen Gabor D.
Published: September 2008

Objective: To determine current practice and attitudes among emergency physicians (EPs) regarding the initiation and termination of CPR.

Methods: An anonymous survey was mailed to randomly selected EPs. Main outcome measures included respondents' answers to questions regarding outcome of resuscitation, and current practice regarding initiation, continuation, and termination of resuscitation for victims of cardiopulmonary arrest.

Results: The 1,252 respondents were from all 50 states, a variety of practice settings, and varying board certification. Most (78%) respondents honor legal advance directives regarding resuscitation. Few (7%) follow unofficial documents, or verbal reports of advance directives (6%). Many (62%) make decisions regarding resuscitation because of fear of litigation or criticism. A majority (55%) have recently attempted numerous resuscitations despite expectations that such efforts would be futile. Most respondents indicated that ideally, legal concerns should not influence physician practice regarding resuscitation (78%), but that in the current environment, legal concerns do influence practice (94%).

Conclusions: Most EPs attempt to resuscitate patients in cardiopulmonary arrest, regardless of futility, except in cases where a legal advance directive is available. Many EPs' decisions regarding resuscitation are based on concerns of litigation and criticism, rather than their professional judgment of medical benefit or futility. Compliance with patients' wishes regarding resuscitation is low unless a legal advance directive is present. Possible solutions to these problems may include standardized guidelines for the initiation and termination of CPR, tort reform, and additional public education regarding resuscitation and advance directives.
Patient Transfer from Nursing Home to Emergency Department: Outcomes and Policy Implications
Authors: Jones Jeffrey S. , Dwyer Paul R. , White Lynn J. , Firman Russ
Published: September 2008

Objective: To describe the process and outcomes of nursing home (NH) residents transferred to hospital EDs.

Methods: This was a prospective, observational study conducted at 2 Midwestern community teaching hospitals during a 12‐month period. All elder patients (>64 years of age) transferred to hospital EDs from regional NHs were eligible for the study. Hospital records were used to abstract relevant descriptive and clinical data. Need for ambulance use was graded prospectively using 3 categories of urgency developed in other studies. Transfers were considered “appropriate” based on outcome measures or if the problem necessitated diagnostic and/or therapeutic procedures not available in the NH. Transfer documentation was evaluated using a standardized 18‐item checklist.

Results: A total of 709 consecutive NH patients made 1,012 ED visits. Their mean age was 83.4 years (range 65–100); 76% were female. The majority of patients (94%) were transferred by ambulance. Ambulance transfer was classified as emergent (16% of patients), urgent (45%), or routine (39%). There were 319 (45%) patients subsequently admitted to the hospital. Approximately 77% (546/709) of the NH transfers were considered appropriate by the emergency physician (EP). Sixty‐seven patients (10%) were transferred without any documentation. For those patients with transfer documentation. 6 common discrepancies were identified.

Conclusion: Although the majority of NH transfers in this population were appropriate, many patients were transferred without adequate documentation for the EP.
ATP‐dependent ligases in trypanothione biosynthesis – kinetics of catalysis and inhibition by phosphinic acid pseudopeptides
Authors: Oza Sandra L. , Chen Shoujun , Wyllie Susan , Coward James K. , Fairlamb Alan H.
Published: September 2008

Glutathionylspermidine is an intermediate formed in the biosynthesis of trypanothione, an essential metabolite in defence against chemical and oxidative stress in the Kinetoplastida. The kinetic mechanism for glutathionylspermidine synthetase (EC 6.3.1.8) from Crithidia fasciculata (CfGspS) obeys a rapid equilibrium random ter‐ter model with kinetic constants KGSH = 609 μm, KSpd = 157 μm and KATP = 215 μm. Phosphonate and phosphinate analogues of glutathionylspermidine, previously shown to be potent inhibitors of GspS from Escherichia coli, are equally potent against CfGspS. The tetrahedral phosphonate acts as a simple ground state analogue of glutathione (GSH) (Ki ∼ 156 μm), whereas the phosphinate behaves as a stable mimic of the postulated unstable tetrahedral intermediate. Kinetic studies showed that the phosphinate behaves as a slow‐binding bisubstrate inhibitor [competitive with respect to GSH and spermidine (Spd)] with rate constants k3 (on rate) = 6.98 × 104 m−1·s−1 and k4 (off rate) = 1.3 × 10−3 s−1, providing a dissociation constant Ki = 18.6 nm. The phosphinate analogue also inhibited recombinant trypanothione synthetase (EC 6.3.1.9) from C. fasciculata, Leishmania major, Trypanosoma cruzi and Trypanosoma brucei with Kiapp values 20–40‐fold greater than that of CfGspS. This phosphinate analogue remains the most potent enzyme inhibitor identified to date, and represents a good starting point for drug discovery for trypanosomiasis and leishmaniasis.
Pituitary adenylate cyclase‐activating polypeptide attenuates streptozotocin‐induced apoptotic death of RIN‐m5F cells through regulation of Bcl‐2 family protein mRNA expression
Authors: Onoue Satomi , Hanato Junko , Yamada Shizuo
Published: September 2008

Oxidative stress, followed by the apoptotic death of pancreatic β cells, is considered to be one of causative agents in the evolution of the type 2 diabetic state; therefore, the protection of β cells can comprise an efficacious strategy for preventing type 2 diabetes. In the present study, RIN‐m5F cells (i.e. the rat insulinoma β cell line) were stimulated with streptozotocin, resulting in a time‐ and concentration‐dependent release of lactate dehydrogenase. There appeared to be significant apoptotic cell death after 2 h of treatment with streptozotocin at 10 mm, as demonstrated by terminal deoxynucleotidyl transferase‐mediated dUTP nick end‐labeling staining and 2.6‐fold activation of cellular caspase‐3, an apoptotic enzyme. By contrast, some neuropeptides of the glucagon‐secretin family and coenzyme Q10, an endogenous mitochondrial antioxidant, could attenuate streptozotocin cytotoxicity, and especially pituitary adenylate cyclase‐activating polypeptide (PACAP), at a concentration of 10−7 m, exhibited 34% attenuation of lactate dehydrogenase release from streptozotocin‐treated RIN‐m5F cells. Quantitative RT‐PCR experiments indicated the inhibitory effect of PACAP on streptozotocin‐evoked up‐regulation of pro‐apoptotic factor (Noxa and Bax) and a 2.3‐fold enhancement of Bcl‐2 mRNA expression, a pro‐survival protein, was also observed after addition of PACAP. The data obtained suggest the anti‐apoptotic role of PACAP in streptozotocin‐treated RIN‐m5F cells through the regulation of pro‐apoptotic and pro‐survival factors.
Experimental Study of Nest‐site Selection in the Biscutate Swift (Streptoprocne biscutata, Aves: Apodidae) in Southern Brazil
Authors: Pichorim Mauro , Roper James J. , Monteiro Filho Emygdio Leite de Araújo
Published: September 2008

Biscutate swift Streptoprocne biscutata nests are usually built on protected rocky cliff walls. Birds often renest at the same location. Remains of previous nests may offer information about potential nests and quality of nest‐sites. Here, we experimentally study nest‐site selection to test the hypothesis that information from previous nests is used in current nest‐site selection. We placed old nest material at artificial nest‐sites to test whether new nest‐sites are chosen based on the presence of nesting material. We also tested whether the use of natural nest‐sites is influenced by nesting material by creating two types of natural sites: previously used natural nest‐sites with vestiges of old nests removed and never used natural nest‐sites to which vestiges of old nests were added. In the first experiment, in 139 nest‐use opportunities, 16 artificial nest‐sites were used, all of which included vestiges. In the second experiment, in 91 nest‐use opportunities, four nests were in previously unused but natural locations to which vestiges had been added, 22 nests were in previously used sites without vestiges, and the remaining 65 nests remained unused. Two processes are apparently in action: first, prior experience and memory; second, vestiges indicate where nesting has occurred, possibly useful for first breeding, or for imperfect memory. Previous nesting information may explain why swifts use nesting locations for many years and why new nesting colonies seldom form. This transmission of information suggests that swifts tend to be conservative and nest where previous nesting has occurred.
A Meta‐Analysis of the Impact of Anthropogenic Forest Disturbance on Southeast Asia's Biotas
Authors: Sodhi Navjot S. , Lee Tien Ming , Koh Lian Pin , Brook Barry W.
Published: September 2008

The impacts of tropical deforestation and forest degradation on SE Asia's biotas have been documented, but a quantitative synthesis is currently lacking. We examined the responses of biodiversity to anthropogenic forest disturbance by comparing key ecological attributes between undisturbed and neighboring disturbed forests. Based on data from four taxonomic groups (vascular plants, invertebrates, birds, and mammals), six broad measures of ‘ecological health’ (e.g., richness, abundance, and demographics), and a range of different impact types from 120 articles published, we calculated the proportion of pairwise comparisons in which the measure of ecological health was lower in impacted than in pristine sites, as would be expected if forest disturbance was detrimental. The explanatory power of correlates of disturbance sensitivity was assessed using an information‐theoretic evaluation of a candidate set of generalized linear models (GLMs). Overall, 73.6 percent (95% CI = 70.8–76.2%) of 1074 pairwise comparisons supported the expectation that forest disturbance was detrimental to ecological health, with mammals being the most sensitive group. The median effect size was for pristine areas to have 22.2 percent higher ecological health than equivalent disturbed areas. The most responsive measure of ecological health was species richness (median = 28.6% higher in pristine), and agricultural areas were the most ecologically degraded (median = 35.6% higher in pristine). However, the GLMs revealed no marked differences overall between taxonomic groups, habitat impact types, or ecological health measures. Our finding implies that the sensitivity of biodiversity to forest disturbance is moderately high, but essentially universal, suggesting urgent forest conservation actions.
Diversity and evenness from sequential sightings
Authors: COOK L. M.
Published: September 2008

Abstract.  A method is described for estimating diversity and evenness by observing sequences of sightings of butterflies. Repeat trials in two forest areas produced consistent results and showed a difference between habitats. This is a quick and easy way to assess the pattern in some insect communities, practical when there is little taxonomic expertise.
Towards Dynamic Biological Oceanography and Limnology
Authors: Legendre L. , Demers S.
Published: September 2008

A new approach that couples the study of biological and hydrodynamic processes has progressively emerged in the biological oceanographic and limnological literature. A review of a large number of papers on phytoplankton, zooplankton, and fish larvae published in the last decade brings out the major characteristics of a new discipline, termed by the authors "dynamic biological oceanography" or "dynamic biological limnology." These studies recognize hydrodynamics as the driving force of aquatic ecosystems, so that the various physical, chemical, and biological factors of the environment are considered as the proximal agents through which hydrodynamic variability is transmitted to living organisms. A central idea to dynamic biological oceanography and limnology is that different hydrodynamic processes and different biological responses occur on different spatial and temporal scales. This leads to a discussion of spatial and temporal scales on both the horizontal and vertical axes and of the relationships between the physical and biological scales, on the one hand, and the sampling scale, on the other. Anticipated forthcoming developments concern the eventual merging of horizontal and vertical studies in an integrated approach to aquatic ecosystems and the design of new sampling techniques and schemes to probe the significant scales of variation in dynamic biological oceanography and limnology. Common lines of research are suggested for the coming years.
Alteration of Fish Communities in Lakes Stressed by Acid Deposition and Heavy Metals near Wawa, Ontario
Authors: Somers Keith M. , Harvey Harold H.
Published: September 2008

Based on chemical criteria such as excess sulfate and low bicarbonate relative to cation, 50 lakes in the Wawa area show some degree of acidification. We conclude that the observed perturbations of lake chemistry and fish populations were primarily the result of smelting operations in the Wawa area. Six lakes have acidified to pH 3.1–4.1 and had high concentrations of metals such as Al, Mn, and Fe. Most of the lakes were in contact with felsic and mafic metavolcanic rocks containing minerals such as siderite, and only a few lakes had granitic basins. The six most acidic lakes contained no fishes and some lakes in the fume-kill area had known losses of brook trout (Salvelinus fontinalis) and lake trout (Salvelinus namaycush) populations. Based on a regression of number of species on lake area for 34 lakes, it was estimated that 83 fish populations have been lost from 16 lakes. Fish community changes were difficult to assess due to the distributions of species in the four watersheds. The northern pike (Esox lucius)–walleye (Stizostedion vitreum vitreum)–yellow perch (Perca flavescens) community was found now to be present only in lakes distant from the source of emissions. The fish community with brook and/or lake trout as the top predator was the most affected.
Babine Lake Sockeye Salmon (Oncorhynchus nerka) Enhancement Program: Testing some Major Assumptions
Authors: McDonald J. , Hume J. M.
Published: September 2008

The objective of the Babine Lake sockeye salmon (Oncorhynchus nerka) enhancement project was to increase fry outputs (and thus, smolt outputs and adult returns) by expanding and improving available spawning beds through the use of artificial spawning channels and related water flow control facilities. The project proceeded on four basic assumptions: (1) the artificial spawning channels would prove an effective means of producing sockeye fry, (2) the fry produced would be as viable as those produced from natural spawning beds, (3) the lake nursery area had the capacity to support larger juvenile populations, and (4) increased smolt outputs would result in increased adult returns. A before and after study has allowed these assumptions to be tested. Egg-to-fry survival in the channels was close to 40%, as expected. Comparisons of wild and channel-produced fry did not reveal any substantial difference in their distribution, growth, and survival in the lake. Increases in the abundance of fry were followed by corresponding increases in the abundance of underyearlings in the lake and seaward migrating smolts. No significant change in the average size of the juveniles or their survival in the lake could be detected when population size increased. While the assumptions regarding juvenile production were found to be generally valid, adult returns did not meet expectations. This was due largely to the lack of response to increased smolt outputs from even-numbered brood years. Some options for future management are offered.
Relationship between Otolith Microstructure and the Growth of Juvenile Chum Salmon (Oncorhynchus keta) under Different Prey Rations
Authors: Volk Eric C. , Wissmar Robert C. , Simenstad Charles A. , Eggers Douglas M.
Published: September 2008

Effects of different prey taxa and daily ration levels on fish growth and the relationship between fish growth rate and mean otolith increment width were investigated for juvenile chum salmon (Oncorhynchus keta) in saltwater aquaria. Growth was positively correlated with ration, and food conversion efficiency was much higher for fish fed the harpacticoid copepod, Tigriopus californicus, than either the calanoid copepod, Pseudocalanus minutas, or the gammarid amphipod, Paramoera mohri. Otolith increments were produced daily for at least the first 160 d after hatching and there was a direct relationship between mean daily otolith increment width and fish growth rate. These results illustrate the possibility that otolith microstructure recapitulates juvenile chum growth histories during estuarine residence.
Influences of Stock and Site on Growth and Mortality in the Blue Mussel (Mytilus edulis)
Authors: Dickie L M. , Boudreau P. R. , Freeman K. R.
Published: September 2008

Reciprocal transfers of three blue mussel (Mytilus edulis) stocks among three rearing sites resulted in marked changes in growth, mortality, and maximum biomass. Results indicate that site differences were major determinants of the growth effects, while stock differences were chiefly responsible for the mortality effects. The overall effect on biomass and potential yield was approximately equally attributable to site and stock influences. The results have relevance to aquaculture and environmental assessment using mussels and illustrate genotypic responses that may be significant for fisheries management.
Susceptibility of Grey (Halichoerus grypus) and Harp (Phoca groenlandica) Seals to the Influenza Virus and Mycoplasma of Epizootic Pneumonia of Harbor Seals (Phoca vitulina)
Authors: Geraci J. R. , Aubin D. j. St. , Barker I. K. , Hinshaw V. S. , Webster R. G. , Ruhnke H. L.
Published: September 2008

Six grey, Halichoerus grypus, and 12 harp, Phoca groenlandica, seals were inoculated intratracheally with lung homogenate containing influenza virus A/seal/Mass/1/80 and mycoplasma from harbor seals, Phoca vitulina, which had died in an epizootic of pneumonia. The grey seals were refractory to infection, whereas some of the harp seals developed mild pneumonia. Virus was recovered from 4 of 10 harp seals necropsied, and antibodies were produced in 2 survivors. The mycoplasma given alone to 2 grey seals did not replicate or produce infection and was recovered from only 1 of 12 harp seals inoculated. We examined 99 grey, 102 harp, 14 harbor, and 7 hooded seals (Cystophora cristata) from eastern Canada and found antibodies to avian influenza A/seal/Mass/1/80 in 3 adult male grey seals from Sable Island, N.S.; this virus is apparently adaptable to other seal species. Related forms of the virus are highly suspect as the cause of past epizootics, and one is currently responsible for a new outbreak of pneumonia in New England harbor seals.
Transport of Dissolved Organic Carbon, Nutrients, and Trace Metals from the Wilson and Blossom Rivers to Smeaton Bay, Southeast Alaska
Authors: Sugai Susan F. , Burrell David C.
Published: September 2008

Regional and seasonal differences in chemical input from the Wilson and Blossom rivers, two pristine, major salmon-producing rivers in southeast Alaska, were examined. For a period of 2 yr, concentrations of dissolved organic carbon, nutrients, Cu, Fe, and Mn in the rivers were determined at approximately monthly intervals and used to calculate export rates. Because of extremely high annual precipitation (400–450 cm) and drainage basins restricted by high topographical relief, the concentrations and export rates of nutrients and Cu are low in the rivers for most of the year. The maximum nutrient export from the Wilson–Blossom system appears to be closely tied to the annual salmon cycle. Iron and Mn export rates from the watersheds are much higher than those for Cu, reflecting solubilization of Fe and Mn under reducing conditions that develop in muskeg ponds during drought periods. The association of metals with organics allows transport of Fe and possibly other metals throughout the fjord system, in contrast with the large-scale removal of metals in or near the river's mouth, as has been observed elsewhere.
Hypolimnetic Aeration and Zooplankton Distribution: A Possible Limitation to the Restoration of Cold-Water Fish Production
Authors: Taggart Christopher T.
Published: September 2008

Hypolimnetic aeration of a 1.23-ha eutrophic kettle lake during two consecutive summers increased [O2] to more than 4 mg/L in the hypolimnion for extended periods. This improvement did not lead to the expected development of crustacean populations in the previously anoxic, zooplankton-deficient hypolimnion. The rotifer Filinia longiseta was the only zooplankter present, as isolated populations, in both the epilimnion and hypolimnion during summer. Eighty percent of the summer zooplankton community occurred exclusively in the epilimnion, and this was related to the development of an anoxic and toxic metalimnion that restricted migration from the epilimnion to the hypolimnion. Confinement of the zooplankton to the epilimnion coupled with predation by fathead minnows (Pimephales promelas) appeared to be responsible for the change in the zooplankton community from large cladocerans and copepods to smaller species. This study suggests that hypolimnetic aeration as a means of restoring or enhancing the production of cold-water fish may be thwarted by the development of a stable anoxic and toxic metalimnion that precludes the development of the zooplankton food resource.
Comparison of Three Methods for Estimating the Food Intake of a Fish
Authors: Majkowski Jacek , Hearn William S.
Published: September 2008

Majkowski and Waiwood's (1981. Can. J. Fish. Aquat. Sci. 38: 1199–1206) method for evaluating the food intake of a fish involves numerically solving a first-order ordinary differential equation and using a minimization procedure. In this note, that method is compared with its two modifications created by (1) the elimination of a mathematical approximation ("improved method") (but this makes the food intake estimation computationally even more difficult), and (2) the introduction of a different mathematical approximation ("simplified method") to involve only simple algebraic calculations. As a result of the latter modification, a certain assumption in the original and improved methods is relaxed and the required experimental information is reduced. Growth and bioenergetic data concerning Gulf of St. Lawrence cod (Gadus morhua) are used to illustrate the three methods and to examine the validity of the mathematical approximations introduced. The use of the original method results in larger errors in food intake estimates for cod than the simplified method. The food intake estimates using the improved method differ considerably (by 3.6–23.5% and 1.7–10.4%, respectively) from those based on the original and simplified methods, if the corresponding ratio of the weight increment to the initial weight is large (>2.3).