bluuebunny/crossref_metadata_2025 huggingface dataset:
The Sensitivity and Specificity of the Case Definition Criteria in Mersin
Authors: özge A , Bugdayci R , Sasmaz T , Kaleagasi H , Kurt ö , Karakelle A , Tezcan H , Siva A
Published: March 2003

The objectives of the present study were: (i) to estimate the prevalence of recurrent headaches in schoolchildren (ranging from 2nd to 5th degrees) in Mersin city of Turkey; (ii) to determine the sensitivity, specificity, positive predictive value and positive likelihood ratio of the diagnostic headache characteristics in children with migraine and tension-type headache (TTH) using neurologist's diagnosis as the gold standard. The stratified sample of study was composed of 5562 children. The prevalence of recurrent headache was 49.2% (2739 of 5562) and the prevalence of current headache was 31.3% (859 of 2739). TTH was more common than migraine (24.7% vs. 10.4%). The most sensitive headache characteristic for migraine was ‘severity of pain’ and the most sensitive definitive symptom was ‘duration of headache’ in children with TTH. International Headache Society-based symptom definition criteria are highly beneficial in diagnosis of childhood headache, if used together with detailed clinical assessment.
Decreased Stnf-Ri in Migraine Patients?
Authors: Empl M , Sostak P , Riedel M , Schwarz M , Müller N , Förderreuther S , Straube A
Published: March 2003

Tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) have recently been found to have a pain-mediating function in addition to their immunological, proinflammatory function. According to the hypothesis of neurovascular inflammation in migraine, these two cytokines could contribute to migraine pain generation. We analysed IL-6 and its soluble receptors sIL-6R and sgp130 as well as TNF-α and its soluble receptor sTNF-RI in 27 migraine patients and eight headache-free controls. Migraine patients tended to have less sTNF-RI (794 ± 158 pg/ml) than controls (945 ± 137 pg/ml). No differences in cytokine concentrations were observed. If TNF-α plays a role in migraine physiopathology, migraine patients may lack sufficient antagonistic sTNF-RI to neutralize hyperalgesic TNF-α during a migraine attack.
Symptoms of Depression and Anxiety, and Screening for Mental Disorders in Migrainous Patients
Authors: Kowacs F , Socal MP , Ziomkowski SC , Borges-Neto VF , Toniolo DP , Francesconi CRM , Chaves MLF
Published: March 2003

The purpose of this clinic-based study was the assessment of symptoms of depression, anxiety, and non-specific psychiatric disorders amongst patients with migraine, compared with healthy subjects and with individuals with a non-neurological chronic disease. A cross-sectional study was carried out in which 178 individuals (migraine 51; psoriasis 35; healthy 92) were submitted to three scales: MADRS (depression), STAI-T (anxiety) and SRQ (screening for mental disorders). The subjects with migraine and psoriasis were from the Out-patient Clinics of Headache and of Dermatology, and the healthy volunteers were persons who were accompanying out-patients in the same hospital. Scores were analysed by MANOVA and by association analysis and logistic regression. Scores of all instruments were higher in the migrainous group, but the univariate analysis of association (using cut-offs) showed significance only for suspicion of mental disorders (SRQ). By logistic regression, variables with strongest association to migraine were gender, education, and SRQ in decreasing order.
Cluster Headache as A Manifestation of Intracranial Inflammatory Myofibroblastic Tumour: A Case Report with Pathophysiological Considerations
Authors: Bigal ME , Rapoport AM , Camel M
Published: March 2003

We report a patient with a secondary form of chronic cluster headache, caused by an intracranial presentation of inflammatory myofibroblastic pseudotumour located in the posterior fossa, with total remission of the pain after resection. The headaches were resistant to many of the usual treatments for cluster headache. The patient had two normal computed tomography scans and one normal magnetic resonance imaging of the head before the additional diagnosis of brain tumour was made. This is an unusual cause of cluster headache with intracranial mass, with an unexpected clinical presentation, a rare triggering manoeuvre, unusual pathology and successful treatment. This patient probably had the hypothalamic biological predisposition to cluster headache and, when a small mass disturbed pain-sensitive structures in the posterior fossa, it excited the trigeminovascular system via posterior fossa trigeminal and upper cervical afferents, and triggered the pathophysiological processes that resulted in a secondary form of chronic cluster headache.
Integration versus segregation: the early struggle
Authors: Copeland Ian C.
Published: March 2003

This paper is concerned with the first educational provision for pupils in the UK who were considered dull, backward and defective towards the end of the nineteenth century. In 1870 and 1880, two Royal Commissions were established to examine the conditions prevalent in elementary education. Subsequently, the recommendations of a Royal Commission in 1889 and an Education Department Committee in 1899 concerning the education of blind, deaf and ‘exceptional’ children were ambiguous, and the foundations of these proposals were flawed. During this period, only seven out of the hundreds of school boards in the UK established classes for these pupils. All seven sets of classes were different in their own ways, but two provided a sharp contrast: one displayed the quintessential features of integrated provision, and the other those of separate, segregated education. For personal and ideological reasons, the model of segregated provision prevailed and dominated the future system.
An investigation of the effects of bereavement on mental health and challenging behaviour in adults with learning disability
Authors: MacHale Rosemary , Carey Seán
Published: March 2003

The purpose of the present study was to investigate the impact of bereavement on people with learning disability. Twenty adults with learning disabilities who had experienced the death of a primary caregiver in the previous 2 years were compared with a matched control group on measures of psychiatric disturbance and challenging behaviour. With regard to psychiatric disturbance, significant differences were found for ‘neurotic disorder’ and for ‘organic condition’ among the bereaved group on the Psychiatric Assessment Schedule for Adults with a Developmental Disability (PAS‐ADD). No difference was found for ‘psychotic disorder’ on the PAS‐ADD. As regards challenging behaviour, significant differences were found for ‘irritability’, ‘lethargy’ and ‘hyperactivity’ among the bereaved group on the Aberrant Behavior Checklist (ABC). No differences were found for ‘stereotypy’ or ‘inappropriate speech’ on the ABC. The clinical implications of these findings are outlined, and recommendations for supporting people with learning disabilities who experience bereavement are presented.
Overcoming mutism in adults with learning disabilities: a case study
Authors: Bell Dorothy M. , Espie Colin A.
Published: March 2003

The literature review looks at the range of studies on people with selective mutism, with special emphasis on the field of learning disabilities. It finds three particular references (Labbe & Williamson 1984; Paniagua & Saeed 1988; Cline & Baldwin 1994b) that may be particularly pertinent to those people who appear to reduce their speech progressively over time in terms of both quantity of utterances and also who reduce the number of people to whom they will speak. This paper then considers the case of a woman of 36 years of age with Down's syndrome who had shown selective mutism for over 14 years, although this had become almost complete mutism for the last 8 years. The case was assessed and the woman was asked if she would be willing to participate in an attempt to reinforce communication and to gradually increase the number of words whispered or spoken in the presence of one person at first – the first author. Nonaversive behavioural methods were used and response initiation procedures were developed. Later, generalization of vocalizations to other people in other environments was encouraged. Sessions were carried out three times a week for about 2 months with rapid success. The woman's quality of life at home and her social interactions at the resource centre were also reported to have improved.
Bacteriocin production by protective cultures
Authors: Rodgers S. , Kailasapathy K. , Cox J. , Peiris P.
Published: March 2003

Bacteriocinogenic Lactococcus lactis CSCC 146 and Pediococcus pentosaceus ATCC 43200 can be used to improve the safety of extend shelf‐life cook‐chill foods, however, the information on their growth and bacteriocin production rate at refrigeration temperatures was lacking. These cultures were inoculated at 105–108 cfu/mL in TPGY broth and grown at 10°C. Their populations were enumerated and bacteriocin titre was measured using well diffusion assay. The bacteriocins’ identity produced by L. lactis and P. pentosaceus was confirmed as nisin and pediocin A, respectively, by their enzyme sensitivity pattern. Nisin (>100 IU/mL) was detected between the third and fifth day of storage when the populations of L. lactis reached 108 cfu/mL. Pediocin A (35 AU/mL) was detected on the fourth day when the population of P. pentosaceus reached 109 cfu/mL. Freeze‐drying of the cultures did not reduce the speed of the production of bacteriocins. Colour, mouth‐feel, texture, flavour and the overall acceptability of commercial sous vide meals was not affected by the presence of the cultures.
Patterns and trends in the discovery of new Neotropical mammals
Authors: Patterson Bruce D.
Published: March 2003

Abstract . Each year new mammalian taxa are described from the Neotropics but, contrary to conventional wisdom, these are not solely rats and bats. Since the publication of the last world checklist in 1992, new species and genera have been described from six orders (Didelphimorphia, Paucituberculata, Insectivora, Chiroptera, Primates and Rodentia) and from all South American countries except Guyana, Bolivia and Paraguay. Names and bibliographic references are listed for seven new genera and 57 new species of Neotropical mammals, representing an average of one new genus and eight new species annually. Each year, systematists revalidate an even greater number of names that were previously thought to constitute taxonomic synonyms. Consequently, estimates of mammalian diversity remain imprecise, especially in the tropics, and the pace of new descriptions outstrips even the most recent checklists.
The distribution and prevalence of sponges in relation to environmental gradients within a temperate sea lough: inclined cliff surfaces
Authors: Bell James J. , Barnes David K. A.
Published: March 2003

Abstract. Sponge communities on inclined cliff surfaces (40°) at Lough Hyne Marine Nature Reserve, Co. Cork, Ireland were sampled at five sites (four inside the lough and one on the adjacent Atlantic coast). Each site varied in sedimentation rate and flow regime. Sites ranged from turbulent (with negligible sedimentation) to very low flow (< 3 cm−1) and highly sedimented regimes. Sponge species showed variation between sites and depth. The greatest difference in sponge communities was observed between the most turbulent and most sedimented sites. The distinct zonation patterns, present at all sites, were most pronounced at the highly sedimented sites. Encrusting forms constituted a high proportion of the sponges at all sites. However encrusting species found at the turbulent site were different to those at the sedimented sites. Arborescent species were common, mainly at the sedimented sites within Lough Hyne. Distributions of sponge species are considered with respect to morphological adaptation, competition and physiological adaptation. The distributions of sponge species on inclined surfaces are also compared with those on vertical cliff faces.
Distribution of South African marine benthic invertebrates applied to the selection of priority conservation areas
Authors: Awad A. Adnan , Griffiths Charles L. , Turpie Jane K.
Published: March 2003

Available data on species distributions and endemicity were compiled and examined for 11 groups of South African marine invertebrates (2533 species). For five groups species richness adhered to a well‐documented pattern, increasing from west to east, but for the other groups species richness was highest along the south coast. Endemicity was generally highest along the south coast, and lowest along the east coast. The data base was then analysed using several types of complementarity analyses, each producing a minimum set of potential reserve areas, which cumulatively represent all invertebrate species analysed. Approaches based solely on rarity, species richness and endemicity demonstrated individual biases, suggesting a need to combine all three interests. Combining the three techniques produced similar results to the individual analyses, showing conservation priorities to be highest along the east coast. Specifically, the areas of Port Elizabeth and Durban were ranked high in all analyses. Consistently, a total of 16 sites was necessary to represent all species analysed. Comparisons with similar analyses on fish and seaweeds revealed similar findings. Existing invertebrate records were shown to be biased towards centres of high sampling activity, demonstrating a need of future sampling attention in under‐represented areas.
Changes in vascular alpha1‐ and alpha2‐adrenoceptor responsiveness by selegiline treatment
Authors: Pelat M. , Verwaerde P. , Tran M. A. , Berlan M. , Senard J. M. , Montastruc J. L.
Published: March 2003

Pharmacoepidemiological studies have reported an excess of mortality with selegiline, a MAO B inhibitor used in the treatment of Parkinson’s disease. The mechanism of this putative adverse effect remains unknown but an interaction with the sympathetic nervous system was suggested. The aim of the present study was to investigate the influence of selegiline (10 mg/daily, orally during one week) on vascular alpha1‐ and alpha2‐adrenoceptor responsiveness in conscious unrestrained dogs. Selegiline significantly increased resting values of both systolic and diastolic blood pressures and noradrenaline plasma levels (HPLC) without changing heart rate. Moreover, spectral analysis of systolic blood pressure (Fast Fourier Transformation) showed that selegiline increased the relative energy of a low frequency band without modifying the total spectrum. ED 50 calculated from dose‐pressor response curves with phenylephrine (after beta‐blockade by propranolol), an index of alpha1‐adrenoceptor response or with noradrenaline (after alpha1‐ and beta blockade by prazosin plus propranolol), an index of alpha2‐adrenoceptor response, were significantly higher after selegiline. Selegiline failed to modify the number of platelet alpha2‐adrenoceptors measured by [3H] RX 821002 binding. Yohimbine‐induced increase in noradrenaline release was significantly more marked after selegiline. These results support the evidence that selegiline induces a vascular alpha1‐ and alpha2‐adrenoceptor‐hyposensitivity that can be explained by the increase in noradrenaline release elicited by the drug.
Clinical pharmacology and therapeutic use of the new antiepileptic drugs
Authors: Perucca E.
Published: March 2003

Although older generation antiepileptic drugs (AEDs) such as carbamazepine, phenytoin and valproic acid continue to be widely used in the treatment of epilepsy, these drugs have important shortcomings such as a highly variable and nonlinear pharmacokinetics, a narrow therapeutic index, suboptimal response rates, and a propensity to cause significant adverse effects and drug interactions. In an attempt to overcome these problems, a new generation of AEDs has been introduced in the last decade. Compared with older agents, some of these drugs offer appreciable advantages in terms of less variable kinetics and, particularly in the case of gabapentin, levetiracetam and vigabatrin, a lower interaction potential. Lamotrigine, topiramate, zonisamide and felbamate protect against partial seizures and a variety of generalized seizure types, vigabatrin is effective against partial seizures (with or without secondary generalization) and infantile spasms, while the use of oxcarbazepine, tiagabine and gabapentin is mainly resticted to patients with partial epilepsy (and, in the case of oxcarbazepine, also primarily generalized tonic‐clonic seizures). Levetiracetam, the latest AED to be introduced, has been found to be effective in partial seizures, but its potentially broader efficacy spectrum remains to be determined in clinical studies. Currently, the main use of new generation AEDs is in the adjunctive therapy of patients refractory to older agents. However, due to advantages in terms of tolerability and ease of use, some of these drugs are increasingly used for first‐line management in certain subgroups of patients. Due to serious toxicity risks, felbamate and vigabatrin should be prescribed only in patients refractory to other drugs. In the case of vigabatrin, however, first line use may be justified in infants with spasms.
Drug‐induced prolongation of the QT interval: regulatory dilemmas and implications for approval and labelling of a new chemical entity
Authors: Shah Rashmi R.
Published: March 2003

The views expressed in this paper are those of the author and do not necessarily represent the views or the opinions of Medicines Control Agency, other regulatory authorities or any of their advisory committees.
Membrane effects of ropivacaine compared with those of bupivacaine and mepivacaine
Authors: Mizogami Maki , Tsuchiya Hironori , Harada Jun
Published: March 2003

We compared the effects of ropivacaine, bupivacaine and mepivacaine on membrane lipids in an attempt to determine the anaesthetic mechanism of ropivacaine with structure‐dependent potency. The membrane effects were determined by measuring anaesthetic‐induced changes in the phase transition temperature and the fluorescence polarization of liposomal membranes prepared with cholesterol and phosphatidylcholine. Bupivacaine, ropivacaine and mepivacaine depressed the membrane lipid phase transition and decreased the polarization of liposomal membranes at 0.0625–1.0 mg/mL, indicating that these anaesthetics fluidize membranes at concentrations lower than those in clinical use. Ropivacaine and bupivacaine were effective in fluidizing the membrane core rather than the membrane surface, whereas mepivacaine was a membrane fluidizer acting equally on both regions. In the comparison of membrane fluidization at an equimolar concentration (3.0 mmol/L), ropivacaine was found to be less potent than bupivacaine and more potent than mepivacaine. This membrane‐fluidizing potency was also consistent with the hydrophobic properties of these substances evaluated by reversed‐phase chromatography. Structure‐dependent membrane fluidization associating with hydrophobicity appears to underlie the local anaesthetic effect of ropivacaine as well as those of bupivacaine and mepivacaine.
Odds ratios for hip‐ and lower forearm fracture using peripheral bone densitometry; a case–control study of postmenopausal women
Authors: Saleh M. M. A. , Jørgensen H. L. , Lauritzen J. B.
Published: March 2003

Background: Dual‐energy X‐ray absorptiometry (DXA) measured at the lumbar spine and particularly at the hip remain the gold‐standard for diagnosing osteoporosis. However, devices for assessing the peripheral skeleton present several advantages in terms of lower price and portability. A major concern when using peripheral densitometry is the poor correlation with the central measurements. The main aim of this study is, therefore, to assess the possibility of expressing ultrasound measurements at the heel and bone mineral density (BMD) measured at the distal forearm as fracture odds ratios rather than an absolute measure of bone mass. Methods: A total of 76 women with lower forearm fracture, 47 women with hip fracture and 231 age‐matched women (controls) were included. All had broadband ultrasound attenuation (BUA) and speed of sound (SOS) measured at the heel using the DTU‐one ultrasound scanner as well as BMD measured by dual X‐ray absorptiometry on the DTX‐200 at the distal forearm. Results:  BUA, SOS and BMD at the distal forearm were all significantly lower in fracture patients compared with their respective control groups. The odds ratio for lower forearm fracture was 3·1 (95% CI: 1·8; 5·2) for heel‐BUA (T‐score cut‐off: –2·3), 4·1 (2·3; 7·4) for heel‐SOS (–2·1) and 2·2 (1·3; 3·7) for lower forearm BMD (–2·7). The odds ratio for hip fracture was 3·4 (1·5–7·7) for heel‐BUA (–2·7), 3·6 (1·6; 8·1) for heel‐SOS (–2·6) and 3·2 (1·4; 7·4) for lower forearm BMD (–2·9). Conclusion:  Peripheral densitometry can discriminate between hip‐ and lower forearm fracture patients and age‐matched controls. Significantly elevated odds ratios for incurring these fractures can be calculated using device‐ and site specific t‐score cut‐off values. The results from this case–control study need to be confirmed by prospective cohort studies.
Measurement of the whole body clearance of infused glycerol as a test of liver function after major hepatectomy
Authors: Tappy Luc , Cayeux Marie‐Christine , Gillet Michel , Koestinger Armin , Matter Maurice , Revelly Jean‐Pierre , Berger Mette , Vallet Cedric , Chioléro René
Published: March 2003

Major liver resection can be used in the treatment of liver cancer. The functional capacity of liver parenchyma needs to be evaluated preoperatively because it conditions the outcome. We assessed whether the whole body clearance of glycerol, a substrate essentially metabolized in liver cells, may be suitable as a simple test of liver function. Seven patients after major hepatectomy, six patients after colectomy and 12 healthy subjects were studied. Patients were investigated on the first day after surgery. All participants were studied during a 150‐min basal period followed by a 120‐min infusion of 16 μmol kg−1 min−1 13C‐labelled glycerol. Whole body glycerol clearance was calculated from the change in plasma glycerol concentration. Whole body glucose production was measured with 6,6 2H2 glucose infused as a tracer in the basal state and during glycerol infusion. In addition, 13C glucose synthesis was monitored to quantitate gluconeogenesis from glycerol. Patients after liver resection had higher plasma glycerol concentrations and lower whole body glycerol clearance than healthy subjects and patients after colectomy. They also had higher plasma glucagon concentrations. Their fasting glucose production was mildly elevated in the fasting state and did not change after glycerol infusion, indicating a normal hepatic autoregulation of glucose production. These results indicate that whole body glycerol clearance can be simply determined from plasma glycerol concentrations during exogenous glycerol infusion. It is significantly reduced in patients after major hepatectomy, suggesting that it constitutes a sensitive test of hepatic function. Its use as a preoperative testing procedure remains to be evaluated.
Skin microvascular dilatation response to acetylcholine and sodium nitroprusside in peripheral arterial disease
Authors: Jägrén Christina , Gazelius Bertil , Ihrman‐Sandal Christina , Lindblad Lars‐Eric , Östergren Jan
Published: March 2003

The relative magnitude of endothelial versus non‐endothelial vasodilatation in the skin of limbs of patients with peripheral arterial occlusive disease (PAOD) is not known. We therefore investigated the effects of iontophoretically administered sodium nitroprusside (SNP) and acetylcholine (Ach) on the skin microvascular blood flow measured by laser‐Doppler fluxmetry.

Methods:  Blood flow changes in the skin was measured on the dorsal side of the foot in three different groups: (i) 11 patients (mean age 73 years) with PAOD, with a mean ankle‐brachial index of 0·46, (ii) eight age‐matched elderly healthy volunteers (mean age 73 years) and (iii) young healthy group (n=15; mean age 34 years). For drug administration with iontophoretic technique we used a Periont Micropharmacology System.

Results:  In patients with PAOD, Ach produced a vasodilatation, which was directly correlated to the strength of iontophoretic stimulation. The difference between the patients and the elderly healthy group was significant after the highest stimulation (160 s, P<0·05). The same pattern was found during stimulation with SNP. In comparison with the young healthy group there was a statistically significant difference (P<0·001) with a slower and less pronounced response in patients with PAOD.

Conclusion:  In patients with PAOD it is possible to achieve local vasodilatation from a baseline level by delivering Ach or SNP through the skin. The two vasodilators, acting by different mechanisms, produced the same vasodilatation response, suggesting that the impaired vasodilatation capacity in patients with peripheral arterial disease may not emanate primarily from local endothelial dysfunction in the skin microcirculation.
Lower heart rate response to ergometry rowing than to treadmill running in older men
Authors: Yoshiga Chie C. , Higuchi Mitsuru , Oka Jun
Published: March 2003

For older people exercise intensity is often determined based on heart rate (HR) or the percentage of maximal HR (%HRmax). This study evaluated oxygen uptake (O2) and HR during ergometry rowing (combined arm and leg; sitting exercise) and treadmill running (leg; upright exercise) for 15 older people [age, (mean ± SD) 62 ± 3 years]. The HR was lower during ergometry rowing than during treadmill running at a blood lactate concentration of 4 mmol l−1 (151 ± 4 beat min−1 versus 160 ± 5 beat min−1, P<0·05) and at a maximal effort (171 ± 7 beat min−1 versus 177 ± 7 beat min−1, P<0·05). This was the case although the O2 was higher during ergometry rowing than during treamill running both at a blood lactate concentration of 4 mmol l−1 (3·0 ± 0·4 l min−1 versus 2·7 ± 0·4 l min−1, P<0·05) and at a maximal effort (3·4 ± 0·4 l min−1 versus 3·1 ± 0·3 l min−1, P<0·05]. %HRmax and %HR reserve were lower during ergometry rowing than during treadmill running. The results suggest that, in prescription of rowing for older people, the relation between HR and O2 for rowing and the attenuated HR response to rowing should be taken into consideration.
Disturbance, Diversity, and Invasion: Implications for Conservation
Authors: Hobbs Richard J. , Huenneke Laura F.
Published: March 2003

Disturbance is an important component of many ecosystems, and variations in disturbance regime can affect ecosystem and community structure and functioning. The “intermediate disturbance hypothesis” suggests that species diversity should be highest at moderate levels of disturbance. However, disturbance is also known to increase the invasibility of communities. Disturbance therefore poses an important problem for conservation management, Here, we review the effects of disturbances such as fire grazing, soil disturbance and nutrient addition on plant species diversity and invasion with particular emphasis on grassland vegetation. Individual components of the disturbance regime can have marked effects on species diversity, but it is often modifications of the existing regime that have the largest influence. Similarly, disturbance can enhance invasion of natural communities, but frequently it is the interaction between different disturbances that has the largest effect. The natural disturbance regime is now unlikely to persist within conservation areas since fragmentation and human intervention have usually modified physical and biotic conditions. Active management decisions must now be made on what disturbance regime is required and this requires decisions on what species are to be encouraged or discouraged.
Using Montane Mammals to Model Extinctions Due to Global Change
Authors: McDonald Kelly A. , Brown James H.
Published: March 2003

We use data on the species‐area relationship and the nested subset structure of the boreal mammal faunas inhabiting isolated mountaintops in the Great Basin to develop a simple quantitative model that predicts the number and identity of species that would go extinct under an assumed scenario of changing climate and vegetation. Global warming of 3°C is predicted to cause the loss of 9–62% of the species inhabiting each mountain range and the extinction of three of fourteen species throughout the region. These results suggest (1) that it is possible to make highly plausible predictions about the susceptibility of species to extinction without detailed information about their population biology, and (2) that global and regional environmental changes seriously threaten the survival of species that are restricted in distribution to both natural “habitat islands” and biological reserves.
Influence of Selective Logging on Bird Species Diversity in a Guianan Rain Forest
Authors: THIOLLAY JEAN‐MARC
Published: March 2003

Abstract: The composition and structure of the bird community were investigated in French Guiana (northeastern Amazonia) 1 year and 10 years after selective logging and compared with bird community composition and structure in undisturbed primary forest. A point‐count method was used in which 937 0.25‐ha sample quadrats were censused for 20 minutes each. Whereas logging removed little more than 3 trees/ha, 38% of the forest undergrowth was destroyed and a proportion of the canopy was opened or damaged. An overall 27–33% decrease of species richness, frequency, and abundance occurred after logging, with a less marked decline of diversity and evenness indices, a substantial increase in the proportion of dominant species, and a 45% difference in species composition, weighed by frequency, between logged and undisturbed forest communities. Forty‐two percent of the species from the primary forest decreased sharply or disappeared after logging and only 34% increased or remained unchanged. Microhabitat selection was the main correlate of sensitivity to disturbance. Most affected by logging were species associated with the understory of tall mature stands especially terrestrial species, members of mixed flocks, and solitary sallying insectivores, all of which decreased by 70% to over 90%. Most birds associated with canopy, small gaps, and vine tangles declined by only 10–30%. Small frugivores and species associated with clearings or edges increased. Among other factors, physiological intolerance of understory species to open forest microclimatic conditions (light, heat, or water stress) might influence their avoidance of logged areas. Timber harvesting generated a high level of disturbance, which depressed the bird diversity. After over 10 years of regeneration, the dense regrowth produced a uniform habitat type that still had not recovered the high species richness exhibited by the primary forest under an intermediate level of disturbance.
Accelerating Forest Succession in a Fragmented Landscape: The Role of Birds and Perches
Authors: McClanahan T.R. , Wolfe R.W.
Published: March 2003

Previous research suggests that in highly fragmented forest landscapes ecological succession can be arrested by lack of seeds, but that seed deposition abundance and diversity of bird‐dispersed plants can be enhanced by bird‐attracting structures such as snags. Consequently, bird perches remain a potential tool for accelerating ecological succession and reforesting disturbed land. Consequently, in order to determine the effectiveness of bird perches in reclaiming forested landscapes, seed dispersal, seedbank storage, and recruitment of bird‐dispersed plants was studied on a central Florida mined site with clay‐rich soil undergoing primary succession over a seven‐year period. Data collection included 20 continuous months of seed dispersal data, an analysis of the total and germinable seedbanks, and plant recruitment at one and two years after a fire destroyed perches and burnt vegetation. Seed dispersal to perches reached a peak seedfall by weight in August, which was attributable to nonmigratory birds. Myrica cerifera, the most abundant species dispersed to the sites, was the only species dispersed during the winter and spring months, and it may be a keystone species for the frugivorous bird guild in central Florida. Seedfall beneath perches had a higher diversity of seed genera, and seed numbers (340 seeds m−2 yr−1) were 150 times greater than in sites without perches. Seeds of bird‐dispersed plants in the seedbank under perches numbered 77 ± 33 (m−2) in total and 17 ± 5 for the viable seedbank. The population density of bird‐dispersed plants was 1.4 and 2.0 plants m−2 at one and two years afler the fire. Less than 0.06% of the dispersed seeds survived to become seedlings. Species composition shifted from seedfall to seedlings, with small‐seeded, early‐successional (r‐selected) shrubs and herbs becoming relatively more common than the desired large‐seeded, late‐successional (K‐selected) tree species. Perches attracted birds and associated seeds, but the physically harsh conditions created by primary succession and/or high predation on seeds appeared to reduce the success of the desired late‐successional plant species. Nonetheless, there was a higher abundance and diversity of bird‐dispersed plants under perches, suggesting that perch structures have a limited ability to enhance plant diversity under conditions of primary succession.
Simulated Responses of a Forest‐Interior Bird Population to Forest Management Options in Central Hardwood Forests of the United States
Authors: Thompson Frank R.
Published: March 2003

I used estimates of carrying capacity, survival, fecundity, and edge effects to simulate the responses of a forest‐interior bird population to selection cutting clearcutting, and no timber harvest. I also modeled population sensitivity to changes in fecundity, survival, K, and edge relationships. Because model parameters are based on scant data, results should he regarded as hypotheses to be further investigated or measures of the relative impact or sensitivity (given model assumptions). Simulated population size was greater with no timber harvest than with clearcutting and greater with clearcutting than with group selection when edge effects were included in the model. Without edge effects, population levels were only slightly lower under group selection than under no timber harvest, and greater than clearcutting. Edge effects had only a small impact on population levels under clearcutting. Clearcut size did not have much effect on population levels, but longer and shorter rotation ages resulted in higher and lower population levels, respectively. The model was very sensitive to declines in mean fecundity and survival, suggesting that factors affecting mean demographic rates could be more important than local edge effects. Some methods of timber harvest may be compatible with the conservation of forest‐interior birds, but better demographic data and information on habitat suitability of selectively cut forests and young even‐aged stands is needed to adequately evaluate management options.
The Recovery of an Endangered Plant. I. Creating a New Population of Amsinckia grandiflora
Authors: Pavlik Bruce M. , Nickrent Daniel L. , Howald Ann M.
Published: March 2003

The recovery of endangered plants often requires the creation of new populations in order to decrease the risk of extinction. Despite numerous attempts, no plant species have been fully recovered by creating new populations. Here we report on initial efforts to recover Amsinckia grandiflora Kleeb. ex Gray (Boraginaceae) by re‐establishing the species in appropriate habitat within its historic range, with consideration given to genetic and demographic characteristics of the founding population. An experimental framework with demographic monitoring was used to follow the fates of nutlets (propagules) from two sources (one wild, one cultivated) and to evaluate the effects of habitat manipulations (fire, herbicide application, clipping) for reducing competition from introduced grasses. Founding nutlets from two sources had different germination and genetic characteristics. Nutlets directly descended from a wild population had half the germination potential of nutlets from a cultivated population because of their greater age (about 25 years in cold storage). Levels of genetic variability, as measured by allozyme electrophoresis at 18 loci, were low overall, but much more so in the cultivated population. These data were used to maximize genetic variability among founding nutlets and to predict the frequency of alternative allele carriers in the new population. After sowing and plot treatment at the Lougher Ridge re‐establishment site, the 3460 founding nutlets produced a large number of germinules (1774) during the 1989–1990 growing season, and many (1101) survived to reproduce. From these plants, and estimated 35,800 nutlets were produced, indicating that the population had a high potential for growth during subsequent years. Introduced grasses had significant negative effects on survivorship to reproduction, plant size, and nutlet production in the new Amsinckia population. Grass cover was effectively reduced by using fire or a grass‐specific herbicide. Burning significantly decreased Amsinckia mortality rates early in the growing season and significantly increased survivorship to reproduction and maximum plant size. Herbicide treatment had no effect on mortality rates or survivorship to reproduction, but it significantly increased plant size and, therefore, nutlet output per plant and per plot. The new population should be able to maintain itself within the existing grassland community, but growth and short‐term viability would be assured by management practices that increased the availability of low‐competition habitat patches for Amsinckia occupation.
Status of Piping Plovers in the Great Plains of North America: A Demographic Simulation Model
Authors: Ryan Mark R. , Root Brian G. , Mayer Paul M.
Published: March 2003

A stochastic population growth model using empirical demographic data confirmed that the Piping Plover population of the Great Plains of North America is declining by more than 7% annually. Unchecked, this decline would result in extirpation in approximately 80 years. When recent adult (0.66) and immature (0.60) survival rates were held constant, a 31% increase—from 0.86 to 1.13 chicks fledged per pair—was needed to stabilize the population. Annual population increases of 1% and 2% required 1.16 and 1.19 chicks per pair, respectively. Such growth would result in the Great Plains population reaching the level—(2550 pairs)—needed for delisting from the U.S. Endangered Species Act protection in 53 and 30 years, respectively. One‐ and five‐year delays in the initiation of 1% population growth caused 13 and 67 year delays respectively in reaching recovery.
Values and Perceptions of Invertebrates
Authors: KELLERT STEPHEN R.
Published: March 2003

Abstract: In this paper I explore the value of invertebrates to human society. I initially examine various ecological, utilitarian, scientific, and cultural benefits provided by invertebrate organisms. I then explore the extent of appreciation and understanding of these values among the American public. This assessment was based on a study of residents of the state of Connecticut, including randomly selected members of the general public, farmers, conservation organization members, and scientists. The general public and farmers were found to view most invertebrates with aversion, anxiety, fear, avoidance, and ignorance. Far more positive and knowledgeable attitudes toward invertebrates and their conservation were observed among scientists and, to a lesser extent, among conservation organization members. I finally examine the motivational basis for hostile attitudes toward invertebrates, particularly arthropods, among the general public. Important factors include the possibility of an innate learning disposition, the association of many invertebrates with disease and agricultural damage, differences in ecological scale between humans and invertebrates, the multiplicity of invertebrates, the apparent lack of a sense of identity and consciousness among invertebrates, the presumption of mindlessness among invertebrates, and the radical autonomy of invertebrates from human control.
Meta‐Analysis: A Valuable Tool in Conservation Research
Authors: Fernandez‐Duque Eduardo , Valeggia Claudia
Published: March 2003

Meta‐analysis is the application of quantitative methods to the problem of comparing and combining results from separate but similar analytic studies. Despite its popularity in the social sciences and epidemiology, meta‐analysis has remained virtually unknown in the conservation and ecology literature. Meta‐analytic techniques allow comparison and summary of effect sizes across studies, and they also allow better control of type II errors. In many areas of research in conservation, the existence of a nonzero effect has been demonstrated to a degree that further research to measure the magnitude or the generality of that effect seems not only justified, but also necessary. For illustrative purposes, we have meta‐analyzed five studies that report data on the effects of selective logging on density of birds. The combination of the effect sizes across studies reveals a negative effect of selective logging that was not apparent from the analysis of individual results. We argue that most of the limitations of the technique are also common to the traditional narrative literature review. Thus, the incompleteness of the literature review, the heterogeneity of the measured effects, and/or the effect that unpublished null results may have on the conclusions should not be deciding factors regarding the convenience of performing a meta‐analysis. Meta‐analysis can provide a quantitative summary of the available data that will be stronger evidence for politicians and decision makers than a mere qualitative description of the problem.
Long‐Term Population Development of a Reintroduced Beaver (Castor fiber) Population in Sweden
Authors: Hartman Göran
Published: March 2003

Deliberate reintroductions of locally exterminated animal species to areas within their former ranges is an increasingly important conservation tool. Most reintroductions are fairly recent and still in an initial phase of population development. There are few long‐term studies of reintroduced populations. The aim of this study was to see if the population development of the reintroduced European beaver (Castor fiber) population in Sweden exhibits the same pattern of population development as other introductions, in accordance with general theories, and to discuss possible management consequences. Since the European beaver was reintroduced to Sweden 70 years ago, the population has developed in a way predicted by the Riney‐Caughley model for introduced ungulates, exhibiting an irruption and a subsequent decline. In two study areas, the rate of population increase (r) turned negative after 34 and 25 years and at densities of 0.25 and 0.20 colonies/km2, respectively. The data suggest that management policy for an irruptive species should allow hunting during the rapid‐increase phase, thus maintaining food resources and avoiding uncontrolled population decline.
Evolutionary Consequences of Extinctions in Populations of a Hawaiian Honeycreeper
Authors: Smith Thomas B. , Freed Leonard A. , Lepson Jaan Kaimanu , Carothers John H.
Published: March 2003

We report on the evolutionary change in bill size of a species of Hawaiian honeycreeper resulting from an apparent dietary shift caused by dramatic declines and extinctions of lobelioids, a historically favored nectar source. Although it now feeds mainly on the flowers of the ohia tree (Metrosideros polymorpha), early Hawaiian avifaunal accounts report that the i’iwi (Vestiaria coccinea), which has a long decurved bill, fed primarily on the flowers of Hawaiian Lobelioideae, which typically have long decurved corollas. A coevolutionary association of i’iwi bill and flower morphology has often been asserted. We test the hypothesis that the shift in the i’iwi’s diet from the long corolla lobelioid flowers to ohia flowers, which lack corollas, resulted in directional selection for shorter bills. We evaluate this hypothesis by comparing the morphological characters of museum specimens from the island of Hawaii collected before 1902 with recent specimens from the Hakalau National Wildlife Refuge, Hawaii. We examine evidence of change in morphological characters using multivariate analysis and a nonparametric cubic spline technique. Results from all analyses are congruent: bill length is shorter in recent specimens.
Inbreeding Depression, Environmental Stress, and Population Size Variation in Scarlet Gilia (Ipomopsis aggregata)
Authors: Heschel M. Shane , Paige Ken N.
Published: March 2003

Despite a large body of theory, few studies have directly assessed the effects of variation in population size on fitness components in natural populations of plants. We conducted studies on 10 populations of scarlet gilia, Ipomopsis aggregata, to assess the effects of population size and year‐to‐year variation in size on the relative fitness of plants. We showed that seed size and germination success are significantly reduced in small populations (those 100 flowering plants) of scarlet gilia. Plants from small populations are also more susceptible to environmental stress. When plants from small and large populations were subjected to an imposed stress (combined effects of transplanting and experimental clipping, simulating ungulate herbivory) in a common garden experiment, plants from small populations suffered higher mortality and were ultimately of smaller size than plants from large populations. In addition, experimental evidence indicates that observed fitness reductions are genetic, due to the effects of genetic drift and/or inbreeding depression. When pollen was introduced from distant populations into two small populations, seed mass and percentage of germination were bolstered, while pollen transferred into a large population had no significant effect. Year‐to‐year variation in population size and its effects on plant fitness are also discussed. In one small population, for example, a substantial increase in size from within did not introduce sufficient new (archived) genetic material to fully overcome the effects of inbreeding depression.
Property Rights Case Law and the Challenge to the Endangered Species Act
Authors: Dwyer Lynn E. , Murphy Dennis D. , Ehrlich Paul R.
Published: March 2003

Congress is poised to initiate what could be a lengthy debate over the U.S. Endangered Species Act. In anticipation, proponents of strong Fifth Amendment private property rights guarantees have begun an aggressive campaign pitting those rights against those granted other species in the Act. Little case law exists that considers both property rights and wildlife protection, but inference can be drawn from Supreme Court opinions regarding property rights which may provide insight into likely judicial contributions to resolving tension between property rights and endangered species. We review key legislative history, provisions of the Endangered Species Act, relevant case law, and the implications of recent judicial trends that pertain to property and imperiled species. We then make recommendations that may improve implementation of this critical piece of environmental legislation.