bluuebunny/crossref_metadata_2025 huggingface dataset:
Park Management of Exotic Plant Species: Problems and Issues
Authors: WESTMAN WALTER E.
Published: April 2005

Abstract: Vegetation management policies in public parks in the United States call for the removal of exotic species to the extent feasible. The underlying goal is to preserve samples of wilderness by restoring plant communities to the “natural state” that existed prior to extensive human influence. With limited budgets, park managers are necessarily selective in targeting exotic species for control. If the focus is on the more readily controlled species, however, park landscapes may gradually become populated by more resistant exotics Further, because plants exhibit some redundancy in ecosystem function, exotic plant species can substitute in part for natives in performing a range of ecosystem functions, including wildlife support and soil binding. Consequently the removal of exotics can result in significant perturbations to certain ecosystem functions during the period of transition to native cover. The individualistic paradigm of plant distribution implies that the impact of exotic plant species on invaded communities will vary. Choosing which species to remove requires careful evaluation of the impact of the removal on ecosystem structure and function. The effective balancing of park management goals for wilderness maintenance and recreational use requires clearer recognition of the adaptive response of ecosystems to invasion and a rethinking of the bases for prioritizing which species are to be removed.
Management Options for Preserving Genetic Diversity: Reintroduction of Guam Rails to the Wild
Authors: HAIG SUSAN M. , BALLOU JONATHAN D. , DERRICKSON SCOTT R.
Published: April 2005

Abstract: Population management programs recognize the importance of managing genetic diversity in species that are candidates for eventual reintroduction to natural habitats. The planned 1989 release of captive‐born Guam rails (Rallus owstoni), extinct in the wild since 1986, to the Northern Mariana island of Rota provides an opportunity to evaluate various management options for selecting breeders to produce young rails for release. Six options were compared to determine which one best replicated genetic diversity in the original captive founder population. Heterozygosity, allelic dimity, founder contribution, and founder genome equivalents were used as indicators of genetic diversity.

Option 1: Randomly choose adults for breeding.

Option 2: Choose the most fecund captive breeders.

Option 3: Use allozyme data to choose parents that will produce the most genetically diverse chicks.

Option 4: Choose pairs to equalize founder contribution in the population.

Option 5: Choose pairs to maximize allelic diversity.

Option 6: Choose pairs to maximize founder genome equivalents.

Genetic management options based on pedigree analysis (#4, 5, 6) produced the most genetically diverse release populations for Rota. Managing founder genome equivalents produced a balance between equalizing founder contribution and maximizing allelic diversity, and provided the most genetically diverse population. Randomly selecting breeding pain, choosing the best captive breeding stock, or managing by allozyme data resulted in substantially reduced genetic diversity. Results illustrate that some of the most common approaches to population management or population reintroduction may produce significant loss of genetic diversity, whereas certain genetic management options may actually increase genetic diversity over current population levels.
Lands for Long‐Term Research in Conservation Biology
Authors: BILDSTEIN KEITH L. , BRISBIN I. LEHR
Published: April 2005

Abstract: Success in conservation biology depends upon a synergistic combination of short‐term tactics and long‐term strategies. Although the former are often necessary to forestall immediate habitat losses, the latter provide the critical framework of understanding needed to develop effective short‐term priorities. Although many conservation biologists now emphasize short‐term tactics, prudence dictates the concomitant establishment of long‐term research projects aimed at answering fundamental ecological questions.

One deterrent to amassing such long‐term data bases, aside from time and funding, is a lack of suitable sites where such studies can be conducted on a large scale. We describe two established major land‐holding networks in the United States that could serve as appropriate places to develop long‐term studies: the National Science Foundation's Long‐Term Ecological Research (LTER) sites, and the US. Department of Energy's National Environmental Research Parks (NERPs). Because they consist of established research facilities, both networks can provide conservation biologists with “low‐cost” baseline information on ecological processes, as well as access to a number of representative terrestrial and aquatic habitats under more or less “controlled” conditions suitable for long‐term studies. We recommend that conservation biologists explore the possibility of using these or similarly available sites in their research programs.
Relictual Amphibians and Old‐Growth Forests
Authors: WELSH HARTWELL H.
Published: April 2005

Abstract: Terrestrial and aquatic herpetofauna were sampled by pitfall traps, time‐constrained searches, and area‐constrained searches (stream sites only) over a three‐year period to examine the importance of forest age to amphibians and reptiles. Fifty‐four terrestrial and 39 aquatic sites in Douglas‐fir—dominated, mixed evergreen forests were located in southwestern Oregon and northwestern California Mean age of trees on sites ranged in age from 30 to 560 years. Thirty‐one species of amphibians and reptiles were detected from the 93 localities. Only three species were found primarily on older forest sites: the Del Norte salamander (Plethodon elongatus), the Olympic salamander (Rhyacotriton olympicus), and the tailed frog (Ascaphus truei). Paleoeco‐logic evidence indicates an historical association between these three amphibians and the extant elements of ancient primeval coniferous forests of the Pacific Northwest. The life histories and habitat requirements of these species suggest that these forms are scarce in younger forests because the microclimatic and microhabitat conditions they require generally exist only in older forests. The long‐term viability of these species in northern California and southern Oregon may depend upon developing forestry practices that protect these mitical microclimates and microhabitats.
Land Forms and Winter Habitat Refugia in the Conservation of Montane Grasshoppers in Southern Africa
Authors: SAMWAYS MICHAEL J.
Published: April 2005

Abstract: The importance of topography in evaluation of insect conservation is discussed with reference to grasshoppers in the Natal Drakensberg Mountains, South Africa For these insects, the hilltops act as thermal refugia from winter cold air drainage. Additionally, the increased insolation on the eastern and northern sides of the hilltops, compared with the western and southern sides, attracts the grasshoppers. Crevices in the hill summits provide further microrefugia Burning reduces grasshopper numbers by half and although many species are adapted to burn conditions, the reduced grass cover accentuates the thermal influences. Other animals, and plants, also selectively inhabit these hilltops, making them highly significant conservation refugia in a matrix of thermally inhospitable land. Evaluations for biological conservation should take note of the strong influence that land forms may have on plant and animal local distributions.
Avian Survival Rates and the Extinction Process on Barro Colorado Island, Panama
Authors: KARR JAMES R.
Published: April 2005

Abstract: Selective extinction following isolation of habitat patches may be due to biogeographical (e.g., island size or isolation) and ecological (species natural histories, interspecifc interactions) factors, or their interactions. Among the demographic and life history attributes commonly associated with high extinction probability are small populations, large size of individuals, and population variability. Long‐term capture‐recapture data from forest habitat in central Panama permit an examination of the association between mainland survival rates and extinction on a nearby land‐bridge island Species of birds that no longer occur on Barro Colorado Island (BCI), Panama, have, on average, lower survival rates on the adjacent mainland than species that have persisted on BCI. Moreover, of the species that no longer occur on BCI, those with lower mainland survival rates generally disappeared earlier from the island. My analysis provides little evidence of a relationship between extinction and population size. Recolonization of BCI from the adjacent mainland by the forest undergrowth species studied here is unlikely. Reduced reproductive success on BCI combined with naturally low adult survival rates seems to be responsible for these BCI extinctions. High nest predation and/or altered landscape dynamics are probable agents in the low reproductive success. The methods used here could be employed in other circumstances to identify fragmentation‐sensitive species.
Absence of Blood Parasites in Indigenous and Introduced Birds from the Cook Islands, South Pacific
Authors: STEADMAN DAVID W. , GREINER ELLIS C. , WOOD CHRISTOPHER S.
Published: April 2005

Abstract: We found no protozoan parasites in 79 blood smears of birds from the Cook Islands, South Pacific. Our sample consisted of 55 smears from nine indigenous species of land and aquatic birds, and 24 smears from one introduced land bird The absence or scarcity of avian hematozoa in the Cook Islands is probably due to a very low prevalence of infection among introduced and naturally colonizing species of birds, rather than a scarcity of insect vectors. On one hand, the apparent absence or extreme scarcity of avian hematozoa, particularly the malaria‐causing Plasmodium spp., is fortunate from a conservation standpoint, considering the devastating impact that Plasmodium from human‐introduced mosquitoes and birds has had on the indigenous avifauna of Hawaii during the past century. On the other hand, our results suggest that the indigenous birds of the Cook Islands, much like those of Hawaii, would have little natural resistance to avian malaria should it be introduced. Thus precautions should be taken to prohibit the introduction of potentially infected nonnative birds or mosquitoes in the Cook Islands and elsewhere in Polynesia
Demographic Consequences of Changed Pupping and Hauling Sites of the Hawaiian Monk Seal
Authors: GERRODETTE TIM , GILMARTIN WILLIAM G.
Published: April 2005

Abstract: During the last 30 years, changes in the size of Hawaiian monk seal populations at several locations have been associated with the amount and type of human disturbance. Recreational beach activities caused monk seals to alter their pupping and hauling patterns. Survival of pups in suboptimal habitats was low, leading to gradual population declines. During the last decade at Kure Atoll, the process has been reversed human disturbance on beaches has decreased and traditional pupping and hauling sites have been reestablished Subsequently, high survival rates of young seals, coupled with two successful enhancement programs for female pups, have led to dramatic changes in the age and sex composition of the population. Based on these changes, the monk seal population at Kure Atoll soon should begin to increase. Apparently small behavioral changes in such vital activities as feeding and reproduction can have large demographic consequences. Therefore, monitoring of endangered species should include data on habitat use and age and sex composition, as well as estimates of abundance.
Graduate Education in Conservation Biology
Authors: JACOBSON SUSAN K.
Published: April 2005

Abstract: Cross‐disciplinay approaches stemming from the fields of resource management and biological science provide needed breadth for the education of conservation biologists. The growing urgency of training individuals to protect, maintain, and restore the planet's biological diversity is challenging academic institutions to overcome narrow disciplinary perspectives. Yet the development of programs in conservation biology is inhibited by long‐standing academic constraints, including disciplinary structure, communication barriers among disciplines, and lack of reward systems, research funds, model curricula, and evaluation techniques for cross‐disciplinary work Descriptions of 16 graduate programs in conservation biology indicate that academia is responding to the challenge. Housed in both resource management and biological science departments, these programs offer new degree options as well as new cross‐disciplinary courses, field classes, and research projects.
Assessing Extinction Threats: Toward a Reevaluation of IUCN Threatened Species Categories
Authors: MACE GEORGINA M. , LANDE RUSSELL
Published: April 2005

Abstract: IUCN categories of threat (Endangered Vulnerable, Rare, Indeterminate, and others) are widely used in‘Red lists’of endangered species and have become an important tool in conservation action at international, national, regional, and thematic levels. The existing definitions are largely subjective, and as a result, categorizations made by different authorities diyfer and my not accurately reflect actual extinction risks. We present proposals to redefine categories in tams of the probability of extinction within a specific time period based on the theory of extinction times for single populations and on meaningful time scales for conservation action. Three categories are proposed (CRITICAL, ENDANGE‐, VULNERABLE) with decreasing levels of threat over increasing time scales for species estimated to have at least a 10% probability of extinction within 100 years. The process of assigning species to categories may need to vay among different taxonomic groups, but we present some simple qualitative criteria based on population biology theory, which we suggest are appropriate at least for most large vertebrates. The process of assessing threat is clearly distinguished from that of setting priorities for conservation action, and only the former is discussed here.

Resumen: La categorización de la Uniôn Internacional para la Conservación de la Naturaleza (UICN) de las especies amenazadas (en peligro, vulnerables, raras, indeteminadas y otras) son ampliamente utilizadas en las Listas Rojas de especies en peligro y se ban convertido en una herramienta importante para las acciones de conservacion al nivel internacional, nacional, regional y temático. Las definiciones de las categorias existentes son muy subjetivas y, como resultado, las categorizaciones hechas por diferentes autores dvieren y quizás no reflejen con certeza el riesgo real de extinción. Presentamos propuestas para re‐definir las categoryías en términos de la probabilidad de extinción dentro de un períod de tiempo especifico. Las propuestas estan basadas en la teoría del tiempo de extinción para poblaciones individuales y en escalas de tiempo que tengan significado para las acciones de conservación. Se proponen tres categoryías (CRITICA, EN PELIGRO, VULNERABLE) con niveles decrecientes de amenaza sobre escalas de tiempo en aumento para especies que se estima tengan cuando ménos un 10% deprobabilidad de extinción en 100 años. El proceso de asignar especies a categoryías puede que necesite variar dentro de los diferentes grupos taxóndmicos pero nosotros presentamos algunos criterios cualitativos simples basados en la teoría de la biología de las poblaciones, las cuales suger‐imos son apropiadas para cuando ménos la mayoría de los grandes vertebrados. El proceso de evaluar la amenaza se distingue claramente del de definir las prioridades para las acciones de conservación, sólamente el primero se discute aquí.
Seed Germination Percentage Increases with Population Size in a Fragmented Prairie Species
Authors: MENGES ERIC S.
Published: April 2005

Abstract: Laboratoty germination percentages were relatively low in small populations of royal catchfly (Silene regia), a perennial prairie plant whose distribution has been severely reduced by habitat fragmentation. Populations with more than 150 individuals bad uniformly high (>85%) germination, whereas smaller populations had great variation within and between populations. Germination percentage was related to the natural log of population size (r = .49, p = .017); in small populations the relationship was linear (r = .37, p = .156). Germination success was unrelated to population isolation. The overall dependence of germination percentage on population size has at least two possible explanations: (I) inbreeding depression in recently reduced populations, manifesting itself in lower fitness of seeds; or (2) increased proportion of inferior geitonogamously produced seed caused by reduced hummingbird visitation and reduced interplant movements in small populations.
Cheese, Tourists, and Red Pandas in the Nepal Himalayas
Authors: YONZON PRALAD B. , HUNTER MALCOLM L.
Published: April 2005

Abstract: Langtang National Park in the Nepal Himalayas provides resources for about 30,000 people living in and around the park The park is the site of two cheese factories that produce 14,000 kg of cheese per year for marketing in Kathmandu The factories collect about 140,000 liters of milk annually and use well over 100,000 kg of fuel wood to process the milk into cheese. Loans and one‐year advance payments encourage farmers to maintain large herds of chauri (a yak‐cattle hybrid), and in many areas overgrazing has resulted The presence in the area of large herds of chauri, their herders, and dogs has led to the death of many red pandas, a species that is probably on the verge of extinction in Langtang. It is estimated that there are fewer than 40 red pandas and these are isolated in four or more populations. Their fecundity is low and mortality is high. This problem might be solved by reducing cheese production and restricting the number of chauri while commensurately increasing the price of cheese so that farmers’income from milk could remain the same. Current cheese prices are already too high for Nepali consumers (US $4.30/kg), but cheap by the standards of the Western tourists who are the sole market. Thus, increasing prices would have little impact on the cheese market, but could be translated into a substantial benefit for the farmers, whose use of grazing lands must ultimately be sustainable, and for the red pandas and other wildlife that must share the mountain landscapes with the farmers.
Demography and Conservation of an Endangered Primate, Brachyteles arachnoids
Authors: STRIER KAREN B.
Published: April 2005

Abstract: Demographic data were obtained on one group of muriquis (Brachyteles arachnoides) over an 8‐year period at Fazenda Montes Claros, Minas Gerais, Brazil. During this period, the group rapidly increased in size, growing from 22 to 43 individuals due to 21 births. Eight disappearances or emigrations were offset by eight immigrations. The group also maintained a stable age‐sex class distribution. Inter‐birth intervals averaged 33.8 months, and age at first reproduction was 71/2% years, or 2.7 interbirth intervals. The high birth rate and low mortality rate, along with increased group fissioning and increased home range size, indicate that this group of muriquis is in a stage of expansion. These demographic data also suggest that some small populations of endangered primates can expand in well‐protected babitats without apparent signs of overcrowding or deleterious effects of close inbreeding. These data, as well as the documentation of female migration and male philopatry, provide important guidelines for future management plans for this species.
Case Study of a Population Bottleneck: Lions of the Ngorongoro Crater
Authors: PACKER C. , PUSEY A. E. , ROWLEY H. , GILBERT D. A. , MARTENSON J. , O'BRIEN S. J.
Published: April 2005

Abstract: Lions in the Ngorongoro Crater, Tanzania, form a small and naturally isolated population. In 1962, the Crater lions suffered an epizootic that reduced the population to nine females and one male. An additional seven males apparently immigrated into the Crater in 1964–1965, but there has been no further immigration into the Crater in the past 25 years. By 1975, the population had recovered to its current level of 75‐125 animals. All members of the current Crater population are descended from only 15 founders, and over the years there has been considerable variance in the reproductive success of both sexes. The Crater was probably colonized by lions from the nearby Serengeti ecosystem and the contemporary Crater lion population shows a significant lack of genetic diversity compared to the much larger Serengeti population. The detailed reproductive history of the Crater population was incorporated into a series of stochastic computer simulations that generated distributions of expected allele frequencies under different sets of initial conditions. The simulations suggest that the Crater population may have passed through previous bottlenecks before 1962 but that the level of heterozygosity in the breeding population has been declining since the mid‐1970s, regardless of the population's genetic composition in the 1960s. High levels of inbreeding are correlated with increased levels of sperm abnormality in lions and there is evidence that the reproductive performance of the Crater lions has decreased as a result of decreasing heterozygosity.
The Freshwater Fishes of Madagascar: A Study of an Endangered Fauna with Recommendations for a Conservation Strategy
Authors: REINTHAL P. N. , STIASSNY M. L. J.
Published: April 2005

Abstract: The native Madagascan fish fauna, and most particularly the endemic freshwater community, has undergone severe attrition throughout the surveyed area The decline of the native fauna is strongly correlated with two primary factors: the presence of exotic species, which are now widespread and habitat degradation resulting from extensive forest clearance. In an attempt to document ichthyofaunal changes through time, we compare our collections with historical distribution records (based on museum collections and literature records) from the same areas. The results of this study reveal a pressing need to consider the islands ichthyofauna, watersheds, and river drainages if design of natural areas and parks is to be effective.
The Magnitude of Global Insect Species Richness
Authors: Gaston Kevin J.
Published: April 2005

Abstract:Recent suggestions that insects number tens of millions of species have received much attention. Little consideration, however, has been given to how such estimates compare with what else we know about insect species richness. Perhaps most significantly, the specialist knowledge of the taxonomic community at large has generally been ignored Collation of published and unpublished information from this source provides little to encourage belief in truly vast numbers of undescribed species of insects. For the insect groups for which figures are available, estimates of global total numbers of species are typically less than ten times the numbers of described species. Although minimum global estimates are more readily constructed than upper estimates, these figures uniformly fail to support assertions that there are 30 million or more species of insects. Rather, a figure of less than ten million seems more tenable, and one of around five million feasible.

Additional, more circumstantial, evidence tends to support the idea that insect species numbers may not be as vast as has been claimed First, the contribution of canopy specialists to global richness may be less than often suggested. Second, a higher proportion of species than commonly entertained may have moderate to large geographic ranges. Third, the number of groups failing to increase in richness in the tropics may have been underestimated. Finally, the proportion of undescribed species encountered by many taxonomists seems insufficient to justify estimates of vast species numbers.
Japanese Perceptions of Wildlife
Authors: KELLERT STEPHEN R.
Published: April 2005

Abstract:This paper examines how the Japanese public perceives the natural world und its conservation, mainly wildlife. Limited comparisons are made to the United States. Data was collected in both countries using similar conceptual and methodological frameworks. Closed‐ended surveys were conducted of random samples of the Japanese and American publics, and in‐depth interviews were conducted with 50 environmentally knowledgeable Japanese.

A central interest was the apparent inconsistency of a presumed special Japanese appreciation of nature concurrent with u pattern of widespread environmental abuse extensive@ reported in the literature. The results of this study partially elucidate this paradox. Japanese appreciation for nature was found to be very narrow and idealized, primarily focusing on single species and lacking an ecological and ethical perspective. The Japanese and American publics were both found to possess strong affection for particularly favored species and enjoyed direct experiential contact with individual aspects of the environment. Both cultures were similarly pragmatic toward nature, and somewhat indifferent regarding the environment when it possessed little emotional value. The Japanese public placed far greater value on satisfactions derived from control and mastery over nature. Additionally, the Japanese expressed far less ethical or ecological concern for nature and wildlife than citizens of the United States. Americans also had significantly greater knowledge of wildlife.
On the Ecology, Insect Seed‐Predation, and Conservation of a Rare and Endemic Plant Species: Ebenus amnitagei (Leguminosae)
Authors: HEGAZY AHMAD K. , EESA NAEEM MOHAMED
Published: April 2005

Abstract: Ebcnus armitagei Schweiuf. et Taub(Leguminosae) is a perennial woody species endemic to the western Mediterranean coast of Egypt and Libya The species is uery rare and restricted to a narrow range of distribution. Growth, phenology, seed output, and predation by the bruchid beetle Callosobruchus maculatus F. (Bruchidae—Coleoptera) of a naturally growing population were monitored. Growth and phenology are highly seasonal and correlated with precipitation and temperature. Up to 48.4% of the population is in the juvenile stages, which experience high mortality. Seed predation is extraordinarily heauy. An auerage of 94.4% of seeds in different stages of maturity are consumed or damaged by C. maculatus. Habitat change and biotic factors within populations including seed predation are threatening the species’existence in the wild.

The following are some possible measures for conservation of E. armitagci: (1) small scale habitat conservation (sanctuary), (2) establishment of new populations by artificial means, (3) establishment of a gene (seed) bank, (4) encouraging botanical gardens to conserue the species, and (5) field application of selective insecticides to control the seed predators but not to destroy beneficial insects.
A Conceptual Framework for Evaluating and Quantifying Naturalness
Authors: ANDERSON JAY E.
Published: April 2005

Abstract: Naturalness is a scientific concept that can be evaluated and quantified Intactness or integrity of ecosystems can be defined and assessed in similar ways. Three indices of naturalness are proposed: (1) the degree to which the system would change if humans were removed; (2) the amount of cultural energy required to maintain the functioning of the system as it currently exists; and (3) the complement of native species currently in an area compared with the suite of species in the area prior to settlement. These indices are complementary and provide a conceptual framework for evaluating naturalness. The latter two can be quantified.
Human Impacts in the Greater Yellowstone Ecosystem: Evaluating Sustainability Goals and Eco‐redevelopment
Authors: PATTEN DUNCAN T.
Published: April 2005

Abstract: The Greater Yellowstone Ecosystem is composed of a mosaic of national parks, forests, wildlife refuges, and private lands, each managed with different goals. Perturbations, both natural and anthropogenic, influence these areas. Maintaining naturalness and sustaining the systems within the GEE are desired assessment endpoints in determining the need for ecosystem redevelopment, Ecosystem degradation is a natural response to human impacts, and evaluation of degradation relative to management goals can be used to determine the acceptability of the goals and the potential for eco‐redevelopment Goals may range from maintaining very natural sustainable ecosystems to developing sacrifice areas for heavy tourist use or oil development, To evaluate human impacts in the Greater Yellowstone Ecosystem, management goals for all systems should be reexamined to determine whether the original goals remain appropriate and whether some level of eco‐redevelopment is necessary to achieve these or newly established goals. Special attention should be given to impacts of interactive and cumulative human activities.
Flying Foxes (Chiroptera: Pteropodidae): Threatened Animals of Key Ecological and Economic Importance
Authors: FUJITA MARTY S. , TUTTLE MERLIN D.
Published: April 2005

Abstract: Flying foxes are animals of extraordinary ecological and economic importance throughout forests of the Old World tropics Nearly 200 species play an essential role as forest pollinators and seed dispersers, yet they are frequently misunderstood intensely persecuted and exceptionally vulnerable to extinction Their role in the propagation of numerous important plants remains virtually uninvestigated. However, our review of already available literature demonstrates that at least 289 plant species rely to vatying degrees on large populations of flying foxes for propagation. These plants, in addition to their many ecological contributing produce some 448 economically valuable products. The fact that flying foxes are increasingly threaten and that few baseline data exist on population trends is cause for concern Many appear to be in severe decline, and several species are already extinct. We present initial observations on flying fox importance and survival threats in hopes of highlighting research and conservation needs.
Assigning Conservation Value: A Case Study from India
Authors: DANIELS R.J. RANJIT , HEGDE MALATI , JOSHI N.V. , GADGIL MADHAV
Published: April 2005

Abstract: We assign conservation values to ecological zones, habitat types, and specific localities of the south Indian district ofUttara Kannada on the basis of occurrence of bird taxa This is a two‐step process, assigning values first to individual bird taxa and second to spatial elements based on the occurrence of birds. The attributes of bird taxa considered are geographical distribution at four levels, habitat preferencq taxonomic position, and degree of endanger‐ment Tbe criteria translating the attributes into values are based on the assumption that the rarer, more taxonomically uniqq or more endangered the taxon, the more valuable it is The conservation value of a given bird taxon is thus a point in a seven‐dimensional space. We reduce this to three dimensions by using internal cowelation and clumping of values. Each spatial element may then be assigned a conservation value based on number of taxa and the total and mean conservation value along the three dimensions. The total values are highly correlated with number of taxa, permitting a simplification of the problem at the level of spatial elements to four dimensions. The analysis provides a basis for assigning specific conservation values to five ecological zones of the district; to fyteen natural, quasinatural, and manmade habitat types; and to 107 specific localities. Our analysis shows that degraded evergreen forests, exotic tree plantations, and urban settlements have low conservation value; the other habitat types considered rank high along one or more dimension. We also identza 12 different sets of 20 localities each that would maximize either the diversity of bird taxa or conservation value along the different dimensions. We thus attempt to synthesize diversity and quality of taxa to generate conservation prescriptions, whereas the existing methods tend to emphasize either rare or endangered taxa or total diversity. Such prescriptions would be one useful input into working out an overall conservation strategy for a geographical region.
Radish as a Model System for the Study of Engineered Gene Escape Rates Via Crop‐Weed Mating
Authors: KLINGER TERRIE , ELAM DIANE R. , ELLSTRAND NORMAN C.
Published: April 2005

Abstract: Engineered genes in transgenic crops may escape into the ambient environment via crop‐weed hybridization However, natural crop‐weed muting rates (gene flow) are largely unknown We measured mating between wild and cultivated radishes in an experiment that simulated natural stands around seed multiplication plots. We used a genetic marker to identify, crop‐weed muting events. Although weeds at the cultivar plot margin (1 m distance) received much more gene flow than distant plants, detectable gene flow occurred at our most distant site (1000 m). For insect‐pollinated outcrossing crops like radish, strategies other than distance must be employed to ensure complete isolation.
Comparison of the Four Formulas of Adjusting QT Interval for the Heart Rate in the Middle‐Aged Healthy Turkish Men
Authors: Dogan Abdullah , Tunc Ercan , Varol Ercan , Ozaydin Mehmet , Ozturk Mustafa
Published: April 2005

Objective: The aim of this study was to evaluate the QT intervals at different rest heart rates in healthy middle‐aged Turkish men and to compare the known four QT adjusting methods for heart rate.

Methods and Results: The QT intervals were measured in electrocardiograms of 210 healthy men (mean age = 35–60 years). A curve relating QT intervals and heart rates from 45 to 135 beats/min was constructed for study population. Based on the formula of Bazett, Fridericia, and Framingham, adjusted QT intervals in these range of heart rates were separately estimated. An adjusting nomogram for different heart rates was created using a reference value, which was the measured QT interval at heart rate of 60 beats/min (QTNo= QT + correcting number). These four QT correction methods were compared with each other. The reference value of QT interval at heart rate of 60 beats/min was 382 ms. The relationship between QT and RR interval was linear (r = 0.66, P < 0.001). Nomogram method corrected QT interval most accurately for all the heart rates compared with other three adjusting methods. At heart rates of 60–100 beats/min, the equation of linear regression was QT = 237 + 0.158 × RR (P < 0.001). Bazett's formula gave the poorest results at all the heart rates. The formulas of Fridericia and Framingham were superior to Bazett's formula; however, they overestimated QT interval at heart rate of 60–110 beats/min (P < 0.01). At lower rates (<60 beats/min), all methods except nomogram method, underestimated QT interval (P = 0.03).

Conclusion: Among four QT correction formulas, the nomogram method provides the most accurately adjusted values of QT interval for all the heart rates in healthy men. Bazett's formula fails to adjust the QT interval for all the heart rates.
Extraction of Buried P Waves from Printed Electrocardiograms
Authors: Lin Bryant , Wang Paul J. , Mahapatra Srijoy , Homoud Munther , Link Mark , Estes N.A. Mark , Al‐Ahmad Amin
Published: April 2005

Background: Morphologic identification of ectopic P‐waves from surface ECGs can be challenging, particularly when the P‐wave is buried in the QRST wave complex. Because ECGs are often available on paper and not digitally, we developed a method of subtracting the T‐wave from the buried P‐wave complex on paper ECGs.

Methods: To validate our system, an atrial extrastimulus was introduced during and following the T‐wave. The ECGs were scanned and then transformed from an image format to a digital format. A computer algorithm digitally subtracted a QRST with no buried P‐wave from one with a buried P‐wave, thus resulting in an extracted P‐wave. The extracted P‐waves were compared to the nonburied P‐wave by determining correlation coefficients and by visual grading by two independent reviewers.

Results: Visual grading comparing the buried P‐wave with the exposed paced P‐wave was 94%. The median correlation coefficient was 85%.

Conclusions: An ectopic atrial P‐wave obscured by a coincident QRST wave complex can be accurately derived from printed ECG using this PC‐based system. Addition of this technique to the existing methods may aid in the localization and ablation of ectopic atrial foci.
T‐Wave Abnormalities Are a Better Predictor of Cardiovascular Mortality than ST Depression on the Resting Electrocardiogram
Authors: Beckerman James , Yamazaki Takuya , Myers Jonathan , Boyle Craig , Chun Sung , Wang Paul , Froelicher Victor
Published: April 2005

Background: ST depression and T‐wave amplitude abnormalities are known to be independent predictors of cardiovascular (CV) death, but a direct comparison between them has not been described.

Methods: Analyses were performed on the first electrocardiogram (ECG) digitally recorded on 46,950 consecutive patients at the Palo Alto Veterans Affairs Medical Center since 1987. Females and patients with electrocardiograms exhibiting bundle branch block, left ventricular hypertrophy, electronic pacing, diagnostic Q waves, or Wolff–Parkinson–White syndrome were excluded, leaving 31,074 male patients for analysis (mean age 55 ± 14). There were 1878 (6.0%) cardiovascular deaths (mean follow‐up of 6 ± 4 years). Electrocardiograms were classified using Minnesota code according to the degree of ST depression and T‐wave abnormality, and the nine possible combinations of ST segment and T‐wave abnormalities were recoded for analysis.

Results: The combination of major abnormalities in ST segments and T‐waves carried the greatest hazard [3.2 (CI 2.7–3.8)]. Minor ST depression combined with more severe T‐wave abnormalities carried a hazard of 3.1 (CI 2.5–3.7), whereas minor T‐wave abnormalities combined with more severe ST depression carried a hazard of only 1.9 (CI 1.6–2.3).

Conclusion: While both ST segment depression and abnormal T‐wave amplitude are clinically important, T‐wave abnormalities appear to be greater predictors of cardiovascular mortality.
Magnetocardiogram Recordings in a Nonshielded Environment—Reproducibility and Ischemia Detection
Authors: Steinberg Benjamin A. , Roguin Ariel , Watkins Stanley P. , Hill Peter , Fernando Dharsh , Resar Jon R.
Published: April 2005

Background: Magnetocardiography (MCG) is a noninvasive technology that measures the magnetic field of the heart by superconducting quantum interference devices (SQUID) sensors. The novelty of the present system is that the sensors can be operated without electromagnetic shielding of the examination room, thus allowing the system to be easily installed in the emergency department or chest pain unit. Studies in shielded rooms, found that this imaging modality may have better sensitivity as compared to ECG in detecting ischemia. We aimed (1) to assess the reproducibility, intra‐observer, and interobserver interpretation variability and (2) to assess the MCG maps in the presence of coronary narrowings.

Methods and Results: All measurements were performed in a nonshielded room. For the first part of the study, two MCG maps were recorded in 24 otherwise healthy volunteers (age 20–44 years, median 24, 16 male) in an interval ranging from 2 to 48 hours. The maps were interpreted using the CardioMag software for contour maps, averaged MCG time traces, and waveform morphology of repolarization by two observers blinded to each other. The parameters tested had low disagreement between repeated measurements. The correlations of the intra‐observer and interobserver interpretation were excellent. Secondly, MCG maps were obtained in 29 patients referred for angiography due to suspected coronary artery disease. Nineteen of them had coronary narrowings defined as more than 50%. In this group, 16 (84.2%) had abnormal MCG maps as compared to only 5 (26.3%) who had abnormal ECGs (P < 0.01).

Conclusions: MCG maps can be successfully obtained in a nonshielded room and allow feasible, accurate, and reproducible measurements with little intra‐observer and interobserver variability. Ischemic changes in the heart's magnetic field may occur before electrical changes. Our pilot data suggests that this imaging modality may potentially offer better sensitivity as compared to rest ECG in detecting ischemia in a cohort of patients who had coronary narrowings identified by angiography.
Accelerated Idioventricular Rhythm in the Post‐thrombolytic Era: Incidence, Prognostic Implications, and Modulating Mechanisms after Direct Percutaneous Coronary Intervention
Authors: Bonnemeier Hendrik , Ortak Jasmin , Wiegand Uwe K.H. , Eberhardt Frank , Bode Frank , Schunkert Heribert , Katus Hugo A. , Richardt Gert
Published: April 2005

Background: In the thrombolytic era, the occurrence of accelerated idioventricular rhythm (AIR) has been proposed to be a specific marker for successful reperfusion. The incidence, prognostic implications, and potential modulating mechanisms of AIR after successful restoration of antegrade flow by means of modern reperfusion therapy (i.e., direct percutaneous coronary intervention (PCI)) has thus far not been investigated.

Methods: We prospectively investigated 125 consecutive patients undergoing direct PCI for a first acute myocardial infarction (AMI). The incidence of AIR was determined from 24‐hour Holter monitoring, initiated prior to PCI.

Results: AIR appeared in 19 patients (15.2%). There were no significant differences between patients with or without AIR regarding baseline clinical characteristics. The incidence of AIR was not different between patients with TIMI 2 and 3 flow (13% vs 16%). There were no differences in the incidence of major cardiac events within 12‐month follow‐up in patients with and without AIR. Patients with AIR exhibited higher mean R‐R intervals (mean 24‐hour R‐R interval: 871.3 ± 121 vs 796.4 ± 100 ms, P < 0.01), higher hourly mean values of heart rate variability (SDNN, 64.7 ± 26 vs 49.4 ± 20 ms, P < 0.01; rMSSD, 29.3 ± 15 vs 22.0 ± 12 ms, P < 0.01) and lower serum norepinephrine concentrations (60 minute after PCI, 478.9 ± 357 vs 649.0 ± 499 pg/ml, P < 0.05).

Conclusions: Our findings indicate that AIR is an nonspecific marker for reperfusion of the infarct‐related artery in AMI and thus, predate previous observations of the thrombolytic era. Even though, AIR was associated with higher tonic vagal tone and lower sympathetic activity, the occurrence of AIR had no prognostic impact on the clinical course and was not able to discriminate between complete and incomplete reperfusion.
QT Dynamics and Variability
Authors: Zareba Wojciech , De Luna Antoni Bayes
Published: April 2005

Repolarization dynamics and variability are of increasing interest as Holter‐derived parameters reflecting changes in myocardial vulnerability and contributing to increased risk of arrhythmic events and sudden death. Repolarization dynamics is usually defined as phenomenon describing and quantifying QT adaptation to changing heart rate. The analysis of QT–R‐R slopes in long ECG recordings is one of the ways to evaluate repolarization dynamics. Increased QT–R‐R slopes are frequently observed in patients at risk for cardiac death and arrhythmic events: postinfarction patients, long QT syndrome patients, patients with nonischemic cardiomyopathy as well as in patients taking drugs affecting repolarization. QT variability reflects beat‐to‐beat changes in repolarization duration and morphology and such changes can be quantified using a number of algorithms currently in various phases of development and validation. Increased QT variability is observed in several conditions with increased risk of arrhythmias. Recent data from MADIT II indicate that increased QT variability is a powerful predictor of arrhythmic events in postinfarction patients with left ventricular dysfunction. More studies are needed to determine further the potential clinical usefulness for diagnosing patients and for risk stratification purposes using both QT dynamics and QT variability methods, and compare these methods with exercise‐induced T wave alternans.
The giant star forming halo associated with the radio galaxy PKS 1932–46
Authors: Villar-Martín M. , Tadhunter C. , Morganti R. , Holt J.
Published: April 2005

We report the discovery of a giant (∼160 kpc) knotty extended emission line nebula associated with the radio galaxy PKS 1932–46 at z= 0.23. The 2-d long slit spectra, obtained with VLT-FORS2 at a large angle (∼63°) to the radio source axis, shows that the nebula extends well beyond the radio structure and the ionization cones of the active nucleus. This is one of the largest ionized nebulae yet detected around a radio galaxy at any redshift. The analysis of the ionization, morphological and kinematic properties of the knots suggests that these are star-forming objects, probably compact H ii galaxies. We propose that the giant structure is a star forming halo associated with the debris of the merger that triggered the activity. This study reinforces the view that radio galaxies are activated by major mergers which also trigger substantial star formation. The star formation activity can extend on the scale of a galaxy group, beyond the old stellar halo of the host galaxy.
Resolving IRAS 09111–1007 at 350 µm: a different path to ULIRG formation?
Authors: Khan Sophia A. , Benford Dominic J. , Clements David L. , Moseley S. Harvey , Shafer Richard A. , Sumner Timothy J.
Published: April 2005

We have resolved the ultraluminous infrared galaxy (ULIRG) IRAS 09111–1007 with the new 350-µm-optimized Second Generation Submillimeter High Angular Resolution Camera (SHARC II), and present the first submillimetre fluxes and images for the system. IRAS 09111–1007 comprises two interacting luminous infrared galaxies (LIRGs) with a projected nuclear separation of 39 h71−1 kpc. The western galaxy is roughly four times more luminous in the submillimetre than its eastern counterpart. It is an extremely bright LIRG with an active galactic nucleus (AGN). The classification of the eastern source is uncertain: it could be a Seyfert 2 galaxy or a LINER. We highlight IRAS 09111–1007 as a system that necessitates further study: a double AGN ULIRG whose molecular gas content differs from that of other widely separated pairs, and whose ULIRG phase might not be explained by current multiple-merger and/or final-stage ULIRG scenarios.
Period—colour and amplitude-colour relations for MACHO project Large Magellanic Cloud RR Lyrae stars
Authors: Kanbur S. M. , Fernando I.
Published: April 2005

In this Letter, we analyse period—colour and amplitude-colour relations at minimum, mean and maximum V-band light for 6391 RRab stars in the Large Magellanic Cloud obtained by the MACHO project. Specifically, we find that colour and amplitude are nearly independent of period at minimum light, but that there exists a definite relation between period and colour and amplitude and colour at maximum light. These two properties are consistent with earlier work suggesting that these observed properties are, at least to some extent, explained by the application of the Stefan-Boltzmann law and the interaction of the photosphere and hydrogen ionization front at minimum light. When we examine the slope of the period—colour relation as a function of phase, we find that the slope varies significantly with phase and is small for a wide range of phases around minimum light. This suggests that another factor that needs to be considered when trying to understand RR Lyrae observed properties is their behaviour at different phases during a pulsation cycle.
On gravitational lensing by deflectors in motion
Authors: Sereno M.
Published: April 2005

Gravitational lensing by a spinning deflector in translational motion relative to the observer is discussed in the weak field, slow motion approximation. The effect of rotation, which generates an intrinsic gravito-magnetic field, separates from that due to radial motion. Corrections to the lens equation, deflection angle and time delay are derived.