bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alternative prey can change model–mimic dynamics between parasitism and mutualism
Authors: Kokko Hanna , Mappes Johanna , Lindström Leena 
Published: November 2003

AbstractClassical (conventional) Müllerian mimicry theory predicts that two (or more) defended prey sharing the same signal always benefit each other despite the fact that one species can be more toxic than the other. The quasi‐Batesian (unconventional) mimicry theory, instead, predicts that the less defended partner of the mimetic relationship may act as a parasite of the signal, causing a fitness loss to the model. Here we clarify the conditions for parasitic or mutualistic relationships between aposematic prey, and build a model to examine the hypothesis that the availability of alternative prey is crucial to Müllerian and quasi‐Batesian mimicry. Our model is based on optimal behaviour of the predator. We ask if and when it is in the interest of the predator to learn to avoid certain species as prey when there is alternative (cryptic) prey available. Our model clearly shows that the role of alternative prey must be taken into consideration when studying model–mimic dynamics. When food is scarce it pays for the predator to test the models and mimics, whereas if food is abundant predators should leave the mimics and models untouched even if the mimics are quite edible. Dynamics of the mimicry tend to be classically Müllerian if mimics are well defended, while quasi‐Batesian dynamics are more likely when they are relatively edible. However, there is significant overlap: in extreme cases mimics can be harmful to models (a quasi‐Batesian case) even if the species are equally toxic. A crucial parameter explaining this overlap is the search efficiency with which indiscriminating vs. discriminating predators find cryptic prey. Quasi‐Batesian mimicry becomes much more likely if discrimination increases the efficiency with which the specialized predator finds cryptic prey, while the opposite case tends to predict Müllerian mimicry. Our model shows that both mutualistic and parasitic relationship between model and mimic are possible and the availability of alternative prey can easily alter this relationship.
Explaining the coexistence of asexuals with their sexual progenitors: no evidence for general‐purpose genotypes in obligate parthenogens of the peach‐potato aphid, Myzus persicae
Authors: Vorburger Christoph , Sunnucks Paul , Ward Seamus A. 
Published: November 2003

AbstractIn parthenogens, selection acts on entire genotypes rather than individual alleles. The general‐purpose genotype hypothesis (GPG) predicts that temporally variable environments select for clones with broad ecological tolerances. These general‐purpose genotypes should exhibit low fitness variance and high geometric mean fitness across environments. We tested this hypothesis by comparing the fitness of obligately and cyclically parthenogenetic genotypes of the peach‐potato aphid, Myzus persicae, on three unrelated host plants. We found genetic variation for the relative performance on different hosts, but no difference in geometric mean fitness between obligate and cyclical parthenogens. Thus, for an environmental variable of major importance to aphids, the GPG hypothesis was not supported. In addition, the lack of an overall fitness difference between reproductive modes suggests that cyclical parthenogens incur no cost of polyphenism, but neither can they compensate for the cost of sex during the parthenogenetic phase of their life cycle.
When does parameter drift decrease the uncertainty in extinction risk estimates?
Authors: Ellner Stephen P. 
Published: November 2003

Abstract Halley (2003) proposed that parameter drift decreases the uncertainty in long‐range extinction risk estimates, because drift mitigates the extreme sensitivity of estimated risk to estimated mean growth rate. However, parameter drift has a second, opposing effect: it increases the uncertainty in parameter estimates from a given data set. When both effects are taken into account, parameter drift can increase, sometimes substantially, the uncertainty in risk estimates. The net effect depends sensitively on the type of drift and on which model parameters must be estimated from observational data on the population at risk. In general, unless many parameters are estimated from independent data, parameter drift increases the uncertainty in extinction risk. These findings suggest that more mechanistic PVA models, using long‐term data on key environmental variables and experiments to quantify their demographic impacts, offer the best prospects for escaping the high data requirements when extinction risk is estimated from observational data.
Patterns of functional diversity across an extensive environmental gradient: vertebrate consumers, hidden treatments and latitudinal trends
Authors: Stevens Richard D. , Cox Stephen B. , Strauss Richard E. , Willig Michael R. 
Published: November 2003

AbstractOver the last two decades, although much has been learned regarding the multifaceted nature of biodiversity, relatively little is known regarding spatial variation in constituents other than species richness. This is particularly true along extensive environmental gradients such as latitude. Herein, we describe latitudinal gradients in the functional diversity of New World bat communities. Bat species from each of 32 communities were assigned to one of seven functional groups. Latitudinal gradients existed for the richness, diversity and scaled‐dominance of functional groups. No significant patterns were observed for evenness of functional groups. Measures of functional diversity were different in magnitude and increased towards the equator at a faster rate than expected given the underlying spatial variation in species richness. Thus, latitudinal gradient in species richness alone do not cause the latitudinal gradient in functional diversity. When variation in species composition of the regional fauna of each community was incorporated into analyses, many differences between observed and simulated patterns of functional diversity were not significant. This suggests that those processes that determine the composition of regional faunas strongly influence the latitudinal gradient in functional diversity at the local level. Nonetheless, functional diversity was lower than expected across observed sites. Community‐wide responses to variation in the quantity and quality of resources at the local level probably contribute to differences in functional diversity at local and regional scales and enhance beta diversity.
Rates of spread of marine pathogens
Authors: McCallum Hamish , Harvell Drew , Dobson Andy 
Published: November 2003

AbstractEpidemics of marine pathogens can spread at extremely rapid rates. For example, herpes virus spread through pilchard populations in Australia at a rate in excess of 10 000 km year−1, and morbillivirus infections in seals and dolphins have spread at more than 3000 km year−1. In terrestrial environments, only the epidemics of myxomatosis and calicivirus in Australian rabbits and West Nile Virus in birds in North America have rates of spread in excess of 1000 km year−1. The rapid rates of spread of these epidemics has been attributed to flying insect vectors, but flying vectors have not been proposed for any marine pathogen. The most likely explanation for the relatively rapid spread of marine pathogens is the lack of barriers to dispersal in some parts of the ocean, and the potential for long‐term survival of pathogens outside the host. These findings caution that pathogens may pose a particularly severe problem in the ocean. There is a need to develop epidemic models capable of generating these high rates of spread and obtain more estimates of disease spread rate.
Treatment of Primary Headache in the Emergency Department
Authors: Blumenthal Harvey J. , Weisz Michael A. , Kelly Karen M. , Mayer Renae L , Blonsky Jeffrey 
Published: November 2003

Background.—Each year many patients present to an emergency department for treatment of acute primary headache. We investigated the diagnosis and clinical outcome of patients treated for primary headache in the emergency department.Methods.—Patients treated for acute primary headache in the emergency department completed a questionnaire related to their headache symptoms, response to treatment, and ability to return to normal function. These responses were compared to the treating physicians' observations of the patient's condition at the time of discharge from the emergency department.Results.—Based on the questionnaire, 95% of the 57 respondents met International Headache Society diagnostic criteria for migraine. Emergency department physicians, however, diagnosed only 32% of the respondents with migraine, while 59% were diagnosed as having “cephalgia” or “headache NOS” (not otherwise specified). All patients previously had taken nonprescription medication, and 49% had never taken a triptan. In the emergency department, only 7% of the patients received a drug “specific” for migraine (ie, a triptan or dihydroergotamine). Sixty‐five percent of the patients were treated with a “migraine cocktail” comprised of a variable mixture of a nonsteroidal anti‐inflammatory agent, a dopamine antagonist, and/or an antihistamine; 24% were treated with opioids. All 57 patients reported that after discharge they had to rest or sleep and were unable to return to normal function. Sixty percent of patients still had headache 24 hours after discharge from the emergency department.Conclusion.—The overwhelming majority of patients who present to an emergency department with acute primary headache have migraine, but the majority of patients receive a less specific diagnosis and a treatment that is correspondingly nonspecific.
Exploring the Relationship Between Maternal Migraine and Child Functioning
Authors: Fagan Maria A. 
Published: November 2003

Objective.—To investigate the relationship between mothers' migraines and the roles and expectations of their children.Methods.—Twenty‐five mothers diagnosed with migraine completed questionnaires concerning their levels of migraine‐related disability and their parenting and child‐rearing attitudes. Migraine‐related disability was assessed using the Migraine‐Specific Quality of Life Questionnaire (version 2.1). Parenting and child‐rearing attitudes were assessed using the Adult‐Adolescent Parenting Inventory.Results.—Significant positive relationships were found between the mothers' migraine‐related disability and both inappropriate expectations of their children and parent‐child role reversal; ie, the more migraine‐related disability reported by the mothers, the more they reported having inappropriate expectations of their children and favoring parent‐child role reversal.Conclusions.—This study suggests that migraine may be associated with dysfunctional parenting patterns. More specifically, it suggests that in families wherein the mother has migraine, children may be at risk of inappropriately or prematurely assuming roles for which they are developmentally unready. Clinical implications are that mothers with migraine may benefit from some type of family‐focused intervention, in addition to headache treatment.
Atypical Odontalgia: A Review of the Literature
Authors: Melis Marcello , Lobo Silvia Lobo , Ceneviz Caroline , Zawawi Khalid , Al‐Badawi Emad , Maloney George , Mehta Noshir 
Published: November 2003

Objective.—To review previous reports of cases of atypical odontalgia to examine its epidemiological and clinical characteristics and to explore the etiology and pathophysiology of the disease.Background.—Atypical odontalgia is one of many painful conditions that affect the oral cavity and is often overlooked in the differential diagnosis.Methods.—A search of the literature was performed for all cases of atypical odontalgia reported from 1966 to the present.Results.—The typical clinical presentation of atypical odontalgia that has been reported involves pain in a tooth in the absence of any sign of pathology; the pain may spread to areas of the face, neck, and shoulder. The existing literature suggests that this condition occurs in 3% to 6% of the patients who undergo endodontic treatment, with high female preponderance and a concentration of cases in the fourth decade of life. Deafferentation seems to be the most likely mechanism to initiate the pain, but psychological factors, alteration of neural mechanisms, and even an idiopathic mechanism have been implicated. Not all reported cases were preceded by trauma to the teeth or gums.The treatment of choice is a tricyclic antidepressant, alone or in combination with a phenothiazine. The outcome is usually fair, with many patients obtaining complete relief from pain. Especially in the absence of overt pathology, particular attention should be paid to avoiding any unnecessary and potentially dangerous dental intervention on the teeth.Conclusion.—Atypical odontalgia is surprisingly common, of uncertain origin, and potentially treatable.
Early Intervention With Almotriptan Improves Sustained Pain‐free Response in Acute Migraine
Authors: Mathew Ninan T. 
Published: November 2003

Objective.—To determine whether treatment of migraine with almotriptan, when pain intensity is mild, improves 1‐ and 2‐hour pain‐free and sustained pain‐free rates compared with treatment when pain intensity is moderate or severe.Methods.—This was a post hoc analysis derived from an open‐label, multicenter, long‐term study of the safety, tolerability, and efficacy of almotriptan 12.5 mg. Patients who met International Headache Society criteria for migraine with or without aura were eligible. Patients were instructed to take a single dose of almotriptan 12.5 mg at the onset of a migraine attack. Rescue medication could be taken if migraine pain had not disappeared at 2 hours. A second dose of almotriptan 12.5 mg could be taken if head pain recurred within 24 hours of the initial dose. Patients reported the intensity of pain at baseline and at 1 and 2 hours postmedication using a 4‐point scale: no pain, mild, moderate, or severe pain. They also reported recurrence of pain (return of moderate or severe pain within 2 to 24 hours of taking the study medication) and use of rescue medication. Rescue medication consisted of supplemental analgesics taken for pain relief at 2 to 24 hours postdose. Ergotamines and other 5‐HT1B/1D agonists were excluded as rescue medications. Based on these patient‐reported end points, sustained pain‐free rates, defined as pain‐free at 2 hours with no recurrence from 2 to 24 hours and no use of rescue medication, were calculated.Results.—A higher proportion of migraine attacks of mild intensity were pain‐free at 1 hour (35.3%) compared with attacks of moderate or severe intensity (7.5%) (P < .001). Two‐hour pain‐free rates also were significantly higher with mild intensity pain (76.9%) compared to moderate or severe intensity (43.9%) (P < .001). In addition, recurrence rates and use of rescue medication were reduced when attacks were treated during mild pain. Recurrence was 12.9% for mild pain versus 25.0% for moderate or severe pain (P < .001), and use of rescue medication was 9.4% for mild pain versus 17.2% for moderate or severe pain (P < .001). Sustained pain‐free rates were nearly twice as high when attacks were treated during mild intensity pain (66.6%) compared with attacks treated during moderate or severe pain (36.6%) (P < .001).Conclusion.—Treatment with almotriptan 12.5 mg during migraine attacks of mild pain intensity improves 1‐ and 2‐hour pain‐free and sustained pain‐free responses.
Single‐Site Botulinum Toxin Type A Injection for Elimination of Migraine Trigger Points
Authors: Behmand Ramin A. , Tucker Tarvez , Guyuron Bahman 
Published: November 2003

Background.—Botulinum toxin may be effective in suppressing migraine. Most injection regimens utilized have involved multiple sites.Purpose.—To evaluate prospectively the effect of botulinum toxin type A injections into the corrugator supercilii muscles alone on the frequency and severity of migraine.Methods.—Twenty‐nine patients (24 women, 5 men) with migraine were enrolled in the study. Average age was 45 years (range, 24 to 63). The frequency (number of migraines per month) and intensity (recorded on an analog scale of 1 to 10, 10 being most severe) of headache were recorded before and after treatment. Twenty‐five units of botulinum toxin type A was injected into each corrugator supercilii muscle, for a total of 50 units.Results.—At 2 months, 24 (83%) of 29 patients reported a positive response to the injection of botulinum toxin type A (P < .001). Sixteen patients (55%) reported complete elimination of headache (P < .001), 8 (28%) experienced significant improvement (at least 50% reduction in frequency or intensity) (P < .04), and 5 (17%) did not notice a change in headache. The duration of efficacy of the botulinum toxin type A injections ranged from 6 to 12 weeks, with an average of 8 weeks. In patients who had improvement in migraine but not complete elimination, the headache frequency decreased from 6.4 to 2.1 per month on average (P < .04), and the intensity decreased from 8.6 to 6.1 (P < .04).Conclusion.—These results support the hypothesis that focal injection of botulinum toxin type A may be an effective therapy for migraine.
Impact of Antimigraine Compounds on Cognitive Processing: A Placebo‐Controlled Crossover Study
Authors: Evers Stefan , Rüschenschmidt Jutta , Frese Achim , Rahmann Alexandra , Husstedt Ingo‐W. 
Published: November 2003

Objective.—To evaluate potential cognitive impairment caused by acute antimigraine drugs.Methods.—We conducted a placebo‐controlled, double‐blind, crossover study to detect the short‐term impact of sumatriptan, zolmitriptan, and ergotamine tartrate on cognitive processing as measured by event‐related potentials and a d2 test. Sixteen healthy subjects were enrolled in the study and given placebo, sumatriptan 100 mg, zolmitriptan 2.5 mg, and ergotamine tartrate 2 mg on different days and in random order. Before and 2 hours after drug administration, visually evoked event‐related potentials and a d2 test were measured.Results.—The N2 latency was significantly increased after ergotamine intake. No other significant differences could be observed in all other event‐related potential parameters. In the d2 test, the GZ value was unchanged after ingestion of zolmitriptan and ergotamine, but improved significantly after taking placebo and sumatriptan. The number of relative errors and the concentration value did not change significantly. All results fell within the reference values for the d2 test in all examinations.Conclusion.—Our data suggest that there may be a slight cognitive decline 2 hours after ingestion of ergotamine tartrate and, to an even lesser extent, zolmitriptan, but not after ingestion of sumatriptan or placebo. All changes recorded were very mild and unlikely to be clinically relevant.
Functional Morphology of Stylophoran Echinoderms
Authors: Lefebvre Bertrand 
Published: November 2003

AbstractThe life orientation and mode of life of stylophorans are a subject of much ongoing debate. Examination of the ornamentation occurring both on the arm and theca in several cornutes and mitrates strongly supports the view that the life orientation was similar in all stylophorans and was ‘flat‐surface down’. The presence of an asymmetrical ornamentation adapted to hinder, or minimize, back slippage of the organism in all stylophorans gives strong support to their interpretation as mostly sessile organisms, feeding with the arm facing the current and the theca downstream. The examination of a wide array of thecal morphologies and sculpture patterns displayed by the various groups of cornutes and mitrates allows the identification of three main modes of life in stylophorans: (1) an epibenthic mode of life, with the theca as main anchor to the substrate (e.g. asymmetrical cornutes, Diamphidiocystis); (2) an epibenthic mode of life, with the arm as main anchor to the sediment (e.g. symmetrical cornutes, Peltocystis, primitive Mitrocystitida, some Kirkocystidae); (3) an infaunal mode of life, with the theca buried in a slightly inclined attitude (e.g. some Kirkocystidae, Mitrocystitida with cuesta‐shaped ribs). The partially buried mode of life of Lagynocystis is intermediate between 2 and 3.
Platelet storage solution improves the in vitro function of preserved platelet concentrate
Authors: Karnicki K. , Johnson C. , St Cyr J. , Ericson D. , Rao G. 
Published: November 2003

Background and Objectives  Stored platelets develop biochemical lesions, manifest as depressed haemostatic function, clot retraction and wound healing. ViaCyte™, a proprietary experimental preservative solution (comprising d‐ribose, d‐glucose, Hanks solution, Hepes solution, bovine serum albumin, tic anticoagulant peptide and sterile water), was tested in comparison with the presently accepted storage solution, citrate–dextrose–phosphate–plasma (CDP‐P), to evaluate its ability to preserve platelet function during storage.Materials and Methods  Platelets stored in ViaCyte and platelets suspended in CDP‐P were transferred to polypropylene tubes with PL732 covers and analysed for adenine nucleotide levels (ATP molecules), in vitro agonist‐mediated P‐selectin expression and aggregation.Results  After 5 days of storage at room temperature, 12·2% of platelets stored in ViaCyte exhibited P‐selectin expression at rest, and 64·2% exhibited P‐selectin expression upon activation with thrombin challenge, an increase of 52%. Platelets stored in CDP‐P exhibited 44·4% P‐selectin expression at rest, suggesting significant activation during storage, and thrombin stimulation resulted in P‐selectin expression of 47·9%, an increase of only 2·5% (P ≤ 0·002, untreated vs. treated). ViaCyte also maintained ATP levels throughout the storage period, while these levels became depressed in platelets stored in CDP‐P (P ≤ 0·02, untreated vs. treated). Storing platelets in the experimental preservative solution maintained their ability to aggregate, while control platelets lost their ability to aggregate in response to agonist.Conclusions  ViaCyte appears to protect platelets during storage, reflected by a low level of induced lesions. Platelets stored in ViaCyte maintain energy levels at their resting state, which preserves their ability to aggregate and se crete granule contents, and ensures the availability of additional platelets for activation upon in vitro challenge.