EVOLUTION, Issue 9 2007
Michael S. Webster
Many socially monogamous species paradoxically show signs of strong sexual selection, suggesting cryptic sources of sexual competition among males. Darwin argued that sexual selection could operate in monogamous systems if breeding sex ratios are biased or if some males attract highly fecund females. Alternatively, sexual selection might result from promiscuous copulations outside the pair bond, although several recent studies have cast doubt on this possibility, in particular by showing that variance in apparent male reproductive success (number of social young) differs little from variance in actual male reproductive success (number of young sired). Our results from a long-term study of the socially monogamous splendid fairy-wren (Malurus splendens) demonstrate that such comparisons are misleading and do not adequately assess the effects of extra-pair paternity (EPP). By partitioning the opportunity for selection and calculating Bateman gradients, we show that EPP has a strong effect on male annual and lifetime fitness, whereas other proposed mechanisms of sexual selection do not. Thus, EPP drives sexual selection in this, and possibly other, socially monogamous species. [source]

Suppressing One-Bond Correlations in HMBC Spectra: Improved Performance for the BIRD,HMBC Pulse Sequence

MAGNETIC RESONANCE IN CHEMISTRY, Issue 3 2009
Julien Furrer
Abstract An improved version of the BIRD,HMBC experiment is proposed. In comparison to the original version, the filtering (suppression of 1JCH signals) is accomplished using a double tuned G-BIRD filter positioned in the middle of the long-range correlations evolution period. Compensation of offset dependence by replacing the rectangular 180° pulses with the broadband inversion pulses (BIPs), with superior inversion performance and improved tolerance to B1 field inhomogeneity, significantly improves the sensitivity of the original BIRD,HMBC experiment. For usual one-bond coupling constants ranges (115,180 Hz), optimal results are easily obtained by adjusting the delays, ,, of the BIRD elements to an average J value. For larger ranges (e.g. 110,260 Hz), the use of a double tuned G-BIRD filter allows excellent suppression degrees for all types of one-bond constants present in a molecule, superior to the original scheme and other purging schemes. These attributes make the improved version of the BIRD,HMBC experiment a valuable and robust tool for rapid spectral analysis and rapid checks of molecular skeletons with a minimum spectrometer time. Copyright © 2009 John Wiley & Sons, Ltd. [source]

SETTING FREE THE MOTHER BIRD: ON READING A STRANGE TEXT

MODERN THEOLOGY, Issue 4 2006
RACHEL MUERS
Deuteronomy 22:6,7 has been used in recent theological discussions of environmental ethics. Earlier traditions of interpretation (Jewish and Christian) suggest the further possibility of reading it as a text about how to read texts and about the nature and function of law. This article examines, and offers a contemporary Christian reappropriation of, these traditions of interpretation. The focus is on how the confrontation with the vulnerable other as a locus of divine revelation interrupts and transforms relations of use and exploitation. It is argued that in a Christian reading of the bird's-nest precept Christ "does what the precept does". [source]

A STATISTICAL TEST OF UNBIASED EVOLUTION OF BODY SIZE IN BIRDS

EVOLUTION, Issue 12 2002
Folmer Bokma
Abstract., Of the approximately 9500 bird species, the vast majority is small-bodied. That is a general feature of evolutionary lineages, also observed for instance in mammals and plants. The avian interspecific body size distribution is right-skewed even on a logarithmic scale. That has previously been interpreted as evidence that body size evolution has been biased. However, a procedure to test for unbiased evolution from the shape of body size distributions was lacking. In the present paper unbiased body size evolution is defined precisely, and a statistical test is developed based on Monte Carlo simulation of unbiased evolution. Application of the test to birds suggests that it is highly unlikely that avian body size evolution has been unbiased as defined. Several possible explanations for this result are discussed. A plausible explanation is that the general model of unbiased evolution assumes that population size and generation time do not affect the evolutionary variability of body size; that is, that micro- and macroevolution are decoupled, which theory suggests is not likely to be the case. [source]

COMPARATIVE ANALYSES IN BIRDS: WHAT IS IN A CORRELATION?,

EVOLUTION, Issue 9 2002
Mats Björklund
No abstract is available for this article. [source]

A NEW BASAL LINEAGE OF EARLY CRETACEOUS BIRDS FROM CHINA AND ITS IMPLICATIONS ON THE EVOLUTION OF THE AVIAN TAIL

PALAEONTOLOGY, Issue 4 2008
CHUNLING GAO
Abstract:, We report on a new Early Cretaceous bird from China that sheds significant light on the evolutionary transition between primitive birds with a long bony tail and those with a short tail ending in a pygostyle. A cladistic analysis of basal birds supports the placement of the new fossil as the sister-taxon of all pygostylians. Possessing a unique hand morphology with a phalangeal formula of 2-3-3-x-x and a reduced number of caudal vertebrae lacking a pygostyle, the new specimen reveals anatomical information previously unknown and increases the taxonomic diversity of primitive, non-pygostylian birds. We infer from the specimen that during the evolution of the avian tail, a decrease in relative caudal length and number of vertebrae preceded the distal fusion of caudals into a pygostyle. [source]

APHRODITE AND HER BIRDS: THE ICONOLOGY OF PAGENSTECHER LEKYTHOI

BULLETIN OF THE INSTITUTE OF CLASSICAL STUDIES, Issue 1 2005
MICHAEL TURNER
Two are in the Nicholson Museum in Sydney and three in the Ure Museum in Reading (Figures 1,5; for their details see Appendix 1). All five are decorated with birds of various types and sizes. This paper discusses the prevalence of birds on Pagenstecher lekythoi and looks to identify them. In so doing, it looks at the problems associated with traditional iconographic approaches to such identifications. It then argues for a connection between the birds on Pagenstecher lekythoi and Aphrodite. Finally, it proposes a link between the goddess and the iconography of the lekythoi in general, as well as with their suggested contents and purpose. [source]

Clarithromycin (Biaxin)-lenalidomide-low-dose dexamethasone (BiRd) versus lenalidomide-low-dose dexamethasone (Rd) for newly diagnosed myeloma

AMERICAN JOURNAL OF HEMATOLOGY, Issue 9 2010
Francesca Gay
The objective of this case-matched study was to compare the efficacy and toxicity of the addition of clarithromycin (Biaxin) to lenalidomide/low-dose dexamethasone (BiRd) vs. lenalidomide/low-dose dexamethasone (Rd) for newly diagnosed myeloma. Data from 72 patients treated at the New York Presbyterian Hospital-Cornell Medical Center were retrospectively compared with an equal number of matched pair mates selected among patients seen at the Mayo Clinic who received Rd. Case matching was blinded and was performed according to age, gender, and transplant status. On intention-to-treat analysis, complete response (45.8% vs. 13.9%, P < 0.001) and very-good-partial-response or better (73.6% vs. 33.3%, P < 0.001) were significantly higher with BiRd. Time-to-progression (median 48.3 vs. 27.5 months, P = 0.071), and progression-free survival (median 48.3 vs. 27.5 months, P = 0.044) were higher with BiRd. There was a trend toward better OS with BiRd (3-year OS: 89.7% vs. 73.0%, P = 0.170). Main grade 3,4 toxicities of BiRd were hematological, in particular thrombocytopenia (23.6% vs. 8.3%, P = 0.012). Infections (16.7% vs. 9.7%, P = 0.218) and dermatological toxicity (12.5% vs. 4.2%, P = 0.129) were higher with Rd. Results of this case-matchedanalysis suggest that there is significant additive value when clarithromycin is added to Rd. Randomized phase III trials are needed to confirm these results. Am. J. Hematol., 2010. © 2010 Wiley-Liss, Inc. [source]

Female-Biased Helping in a Cooperatively Breeding Bird: Female Benefits or Male Costs?

ETHOLOGY, Issue 6 2007
Dean A. Williams
There is often a sex bias in helping effort in cooperatively breeding species with both male and female helpers, and yet this phenomenon is still poorly understood. Although sex-biased helping is often assumed to be correlated with sex-specific benefits, sex-specific costs could also be responsible for sex-biased helping. Cooperatively breeding brown jays (Cyanocorax morio) in Monteverde, Costa Rica have helpers of both sexes and dispersal is male-biased, a rare reversal of the female-biased dispersal pattern often seen in birds. We quantified helper contributions to nestling care and analyzed whether there was sex-biased helping and if so, whether it was correlated with known benefits derived via helping. Brown jay helpers provided over 70% of all nestling feedings, but they did not appear to decrease the workload of breeders across the range of observed group sizes. Female helpers fed nestlings and engaged in vigilance at significantly higher levels than male helpers. Nonetheless, female helpers did not appear to gain direct benefits, either through current reproduction or group augmentation, or indirect fitness benefits from helping during the nestling stage. While it is possible that females could be accruing subtle future direct benefits such as breeding experience or alliance formation from helping, future studies should focus on whether the observed sex bias in helping is because males decrease their care relative to females in order to pursue extra-territorial forays. Explanations for sex-biased helping in cooperative breeders are proving to be as varied as those proposed for helping behavior in general, suggesting that it will often be necessary to quantify a wide range of benefits and costs when seeking explanations for sex-biased helping. [source]

The Process and Causes of Fledging in a Cavity-Nesting Passerine Bird, the House Wren (Troglodytes aedon)

ETHOLOGY, Issue 9 2004
L. Scott Johnson
Little is known about the process or causes of fledging or nest-leaving in passerine birds because researchers can rarely predict when fledging will occur in a given nest. We used continuous videotaping of nests to both document the process of fledging in the house wren, Troglodytes aedon, a small, cavity-nesting songbird, and test hypotheses as to what might cause fledging to begin. Fledging began any time from 14 to 19 d after hatching commenced. Slower-developing broods fledged later than faster-developing broods. Fledging typically began within 5 h of sunrise and over 80% of all nestlings fledged before noon. All nestlings fledged on the same day at 65% of nests and over two consecutive days in most other nests. We found no evidence that fledging was triggered by changes in parental behaviour. Parental rate of food delivery to nestlings did not decline during a 3-h period leading up to the first fledging, nor was the rate of feeding just prior to the first fledging lower than the rate at the same time the day before. Moreover, parents did not slow the rate of food delivery to nests after part of the brood had fledged. Hatching is asynchronous in our study population which creates a marked age/size hierarchy within broods. At most nests, the first nestling to fledge was the most well-developed nestling in the brood or nearly so (as measured by feather length). This suggests that fledging typically begins when the most well-developed nestlings in the brood reach some threshold size. However, at about one-fifth of nests, the first nestling to fledge was only moderate in size. At these nests, severe competition for food may have caused smaller, less competitive nestlings to fledge first to increase their access to food. We found no strong support for the suggestion that the oldest nestlings delay fledging until their least-developed nestmate reaches some minimum size, although further experimental work on this question is warranted. [source]

Expression of glutathione transferase isoenzymes in the human H295R adrenal cell line and the effect of forskolin

JOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 4 2002
Tuula Stark
Abstract In previous studies in our laboratory (L. Mankowitz, L. Staffas, M. Bakke, and J. Lund, Biochem J, 1995, 305, 111,118; L. Staffas, L. Mankowitz, M. Söderström, A. Blanck, I. Porsch-Hällström, C. Sundberg, B. Mannervik, B. Olin, J. Rydström, and J.W. DePierre, Biochem J, 1992, 286, 65,72) isoenzymes of GST, primarily of the , class, have been shown to be downregulated by adrenocorticotropic hormone (ACTH) in rat and mouse adrenal cells. In the present investigation the human adrenal H295R cell line (W.E. Rainey, I.M. Bird, and J.I. Mason, Mol Cell Endocrinol, 1994, 100, 45,50) was examined in a similar manner. Analysis by reverse-phase HPLC revealed that these cells express four isoenzymes of GST, i.e., A1, A2, P1, and M4, as well as another unidentified protein that was retained by our affinity column (elution time of 32 min) and, thus, presumably binds glutathione. Among these forms, A1 was present at the highest level. Upon addition of forskolin (an activator of adenylate cyclase which has been shown previously to mimic the effect of ACTH on adrenal cells) to the culture medium, the level of A1 decreased approximately 70% by forskolin, whereas the levels of the other isoenzymes were slightly increased, and that of the unknown form doubled. Thus, the influence of ACTH on expression of GST isoenzymes in this human adrenal cell line differs from that in rat and mouse adrenal cells. © 2002 Wiley Periodicals, Inc. J Biochem Mol Toxicol 16:169,173, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10034 [source]

SIZE INCREMENTS DUE TO INTERINDIVIDUAL FUSIONS: HOW MUCH AND FOR HOW LONG?,

JOURNAL OF PHYCOLOGY, Issue 4 2010
Bernabé Santelices
Size increments following interindividual fusions appear as a general benefit for organisms, such as coalescing seaweeds and modular invertebrates, with the capacity to fuse with conspecifics. Using sporelings of the red algae Gracilaria chilensis C. J. Bird, McLachlan et E. C. Oliveira and Mazzaella laminarioides (Bory) Fredericq, we measured the growth patterns of sporelings built with different numbers of spores, and the magnitude and persistence of the size increments gained by fusions. Then we studied three morphological processes that could help explain the observed growth patterns. Results indicate that in these algae, coalescence is followed by immediate increase in total size of the coalesced individual and that the increment is proportional to the number of individuals fusing. However, the size increments in sporelings of both species do not last >60 d. Increasing reductions of marginal meristematic cells and increasing abundance of necrotic cells in sporelings built with increasing numbers of initial spores are partial explanations for the above growth patterns. Since sporelings formed by many spores differentiate erect axes earlier and in larger quantities than sporelings formed by one or only a few spores, differentiation, emergence, and growth of erect axes appear as a more likely explanation for the slow radial growth of the multisporic sporelings. Erect axis differentiation involves significant morphological and physiological changes and a shift from radial to axial growth. It is concluded that the growth pattern exhibited by these macroalgae after fusion differs from equivalent processes described for other organisms with the capacity to fuse, such as modular invertebrates. [source]

Report of the Council for the session 2006,2007

JOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES A (STATISTICS IN SOCIETY), Issue 4 2007
Council Report
President's foreword., This year's annual report shows another very successful year for the Society. The range of the Society's new initiatives bears testament to our vigour and to the energy and enthusiasm of Fellows and staff. It is difficult to summarize all of these but I offer a brief overview of some of the highlights. This year we have awarded the first annual prize for ,Statistical excellence in journalism'. It is too easy to bemoan the general quality of coverage of statistical issues in the press and other media. But simply moaning does not improve the situation. As a positive step, on the instigation of Sheila Bird and Andrew Garratt, the Society decided to initiate an award for the best journalistic coverage of a statistical issue. This year first prize was awarded to Ben Goldacre of The Guardian. I hope that these annual awards will offer a positive focus on good coverage and help us to promote best practice. This year, also, we have set up the Professional Development Centre to act as a focus for statistical training both for statisticians and for others who use statistical methods as part of their work. It thus reflects our support for continuing professional development for our Fellows and at the same time provides outreach to members of the statistical user community who want to improve their statistical skills. We welcome Nicola Bright as the Director of the Centre and wish her every success. I am pleased to say that it is not just the Society centrally that has taken new activities this year. The Manchester Local Group have initiated a prize for final year undergraduates from any higher education institute in the north-west. At a time when there are concerns about the number of well-qualified graduates coming into the statistics profession this seems an excellent way to attract the attention of final year undergraduates. I wish this initiative every success. Another development to which the Society has contributed is the Higher Education Funding Council for England project ,more maths grads' which is designed to promote participation in undergraduate degrees in the mathematical sciences. A good supply of mathematically trained graduates is essential to the UK economy in general and to the health of the statistics discipline in particular. It is good that the Society is involved in practical developments that are aimed at increasing participation. The final new initiative that I shall draw attention to is the ,first-in-man' report which is concerned with the statistical design of drug trials aimed at testing novel treatment types. The working party was set up as a result of the adverse reactions suffered by healthy volunteers to a first-in-man trial of monoclonal antibodies and who were subsequently admitted to Northwick Park hospital. The report makes a series of recommendations about the design of such trials and will, I hope, contribute to the safety of future trials. I would like to thank Stephen Senn and the members of the working party for their considerable efforts. As well as these new initiatives there were, of course, many other continuing activities that are noteworthy. The annual conference in Belfast was a great success with many lively sessions and a good number of participants. In particular it was good to see a high number of young statisticians participating in the conference, reflecting the continuing impact of the Young Statisticians Forum on which I commented in the previous annual report. Another continuing activity for the Society is the statistical legislation going through Parliament as I write. The Society has long campaigned for legislation for official statistics. The issue now is to try to get good legislation which will have the required effect and will help the Government Statistical Service and other statistical producers to produce high quality, authoritative statistics in an environment that commands public confidence. As first published, the Society was disappointed with the Bill but we have worked to build support for amendments that, in our view, are essential. Time alone will tell how effective the final legislation will be in meeting our aims. I would like to draw attention to the success of the Membership Services team. We, although with other statistical Societies, have experienced a decline in membership in recent years but the team have turned this round. They are helping to recruit new Fellows and to retain the commitment of existing Fellows. This is a fine achievement and I would like to thank Nicola Emmerson, Ed Swires-Hennessy and the whole team. Finally we have, at last, reached a conclusion in our dealings with the Privy Council and will implement the second phase of constitutional changes. In future our business year, financial year and year for elected appointments will all coincide on a calendar year basis. There will be transitional arrangements but in due course all our administrative arrangements will coincide and will improve efficiency and co-ordination. This has been a long journey, steered effectively by our Director General, Ivor Goddard, and I congratulate him for a successful outcome on your behalf. As you read this report, I hope that you will share my impression of a Society that is lively and spawning many new programmes. We have a dual commitment: to the well-being of statistics as a discipline and to the promotion of statistical understanding and practice to the benefit of Society at large. In both respects I feel that the Society is in good health. This is due to the unstinting efforts of a large number of individual volunteers, including in particular our Honorary Officers and also, of course, the staff at Errol Street. On behalf of all Fellows, I wish to express my thanks to everyone involved. Tim Holt [source]

A New Sapeornithid Bird from China and Its Implication for Early Avian Evolution

ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 3 2010
Dongyu HU
Abstract: Recent discoveries of basal birds have greatly improved our understanding of early bird evolution, yet the evolution of several important features such as cranial kinesis and arboreality remain debated. A new sapeornithid bird, Shenshiornis primita gen. et sp. nov., based on an articulated skeleton from the Early Cretaceous Jehol Group of western Liaoning, China, sheds new light on these issues. Shenshiornis possesses a skull as primitive as or even more primitive than that of Archaeopteryx and hind limbs modified for an improved arboreal capability. A cladistic analysis shows that: 1) presence of a diapsid skull is a plesiomorphy of the Aves and a kinetic skull evolved incrementally later in avian evolution; and 2) cursorial capability significantly weakens at the base of the Pygostylia due to a change in locomotor system. [source]

Geophysical evidence for Holocene lake-level change in southern California (Dry Lake)

BOREAS, Issue 1 2010
BROXTON W. BIRD
Bird, B. W., Kirby, M. E., Howat, I. M. & Tulaczyk, S. 2009: Geophysical evidence for Holocene lake-level change in southern California (Dry Lake). Boreas, 10.1111/j.1502-3885.2009.00114.x. ISSN 0300-9483. Ground penetrating radar (GPR) data are used in combination with previously published sediment cores to develop a Holocene history of basin sedimentation in a small, alpine lake in southern California (Dry Lake). The GPR data identify three depositional sequences spanning the past 9000 calendar years before present (cal. yr BP). Sequence I represents the first phase of an early Holocene highstand. A regression between <8320 and >8120 cal. yr BP separates Sequence I from Sequence II, perhaps associated with the 8200 cal. yr BP cold event. Sequence II represents the second phase of the early-to-mid Holocene highstand. Sequence IIIa represents a permanent shift to predominantly low lake stands beginning ,5550 cal. yr BP. This mid-Holocene shift was accompanied by a dramatic decrease in sedimentation rate as well as a contraction of the basin's area of sedimentation. By ,1860 cal. yr BP (Sequence IIIb), the lake was restricted to the modern, central basin. Taken together, the GPR and core data indicate a wet early Holocene followed by a long-term Holocene drying trend. The similarity in ages of the early Holocene highstand across the greater southern California region suggests a common external forcing , perhaps modulation of early Holocene storm activity by insolation. However, regional lake level records are less congruous following the initial early Holocene highstand, which may indicate a change in the spatial domain of climate forcing(s) throughout the Holocene in western North America. [source]

Enantiornithine Bird with Diapsidian Skull and Its Dental Development in the Early Cretaceous in Liaoning, China

ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 1 2004
GONG Enpu
Abstract A large number of enantiornithine birds are discovered from the Early Cretaceous Jiufutang Formation in western Liaoning, China. They are all small-sized birds with a few small teeth. The enantiornithine bird from the Jiufutang Formation in the Shangheshou area, Chaoyang, Liaoning Province reported in this paper is the largest individual known in all enantiornithine birds of the Early Cretaceous. However, its teeth possess a feature of pseudoheterodont. Some different development stages of the new teeth substitute the earlier stages and the stages of development are preserved in this specimen. This development pattern is similar to that of Archaeopteryx and alligator but not dinosaur. A well-developed postorbital was also preserved in the skull, which was a diapsidian skull like that of Confuciusornis. Additionally, the distinctive preservation of its prefrontal distinguishes it from other enantiornithine birds of the Early Cretaceous. [source]

An Early Cretaceous Avialian Bird, Shenzhouraptor sinensis from Western Liaoning, China

ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 1 2003
Ji Qiang
Abstract, This paper describes an avialian bird from the Early Cretaceous Jiufotang Formation in Yixian county, western Liaoning, China, which is named as Shenzhouraptor sinensis by Ji et al. on July 15,2002. Shenzhouraptor sinensis is characterized by no teeth in its mouth, the forelimbs longer than the hindlimbs, a long tail with more than 23 caudal vertebrae, U-shaped wishbone, and remiges longer than the total length of ulna and manus. It is certain that the new avialian bird is really capable of powerful flight, representing a missing link between theropod dinosaurs and birds. [source]

Extended Visual Fixation and Distractibility in Children from Six to Twenty-Four Months of Age

CHILD DEVELOPMENT, Issue 4 2001
John E. Richards
Distractibility during extended visual fixations in children 6 months to 2 years of age was examined. A children's Sesame Street movie (Follow That Bird) was presented to children (N=40) for a minimum of 20 min while fixation was videotaped and heart rate was recorded. Distractors (computer-generated patterns or another Sesame Street movie) were presented on an adjacent television screen. Consistent with prior research with older preschool-age children, the latency to turn toward the distractor was a function of the length of the look occurring before distractor onset. For the period immediately before distractor onset, children had a greater sustained lowered heart rate for the trials on which they continued looking at the center television monitor than for the trials on which they looked toward the distractor. This pattern of distractibility suggests attention increases over the course of a look toward the television, and that heart rate changes reflect this increase in attention. [source]

Performance of neonatal ventilators in volume targeted ventilation mode

ACTA PAEDIATRICA, Issue 2 2007
Atul Sharma
Abstract Aim: To test the hypothesis that in volume targeted ventilation modes, ventilator performance would vary according to ventilator type. Methods: Four neonatal ventilators: Draeger Babylog 8000 (Draeger Medical, Germany), SLE 5000 infant ventilator (SLE systems, UK), Stephanie paediatric ventilator (F. Stephan Biomedical, German) and V.I.P. Bird gold (Viasys Healthcare, USA) were assessed using a lung model. Delivered peak pressure, inflation time, mean airway pressure (MAP) and volume were measured. Results: At the same preset ventilator settings, the Stephanie and V.I.P. Bird ventilators delivered significantly lower peak pressures and tended to deliver lower MAPs than the other two ventilators. At a volume targeted ventilation level of 5 mL, the SLE and the V.I.P. Bird delivered significantly shorter inflation times. The above differences related to differences in the airway pressure waveforms delivered by the four ventilators. The V.I.P. Bird had a less variable volume delivery, but this was always significantly lower than the preset volume guarantee level but higher than the volume displayed by the ventilator. Conclusion: In volume targeted ventilation modes, performance differs between neonatal ventilator types; these results may have implications for clinical practise. [source]

Beware the Dodo Bird: The Dangers of Overgeneralization

CLINICAL PSYCHOLOGY: SCIENCE AND PRACTICE, Issue 1 2002
Dianne L. Chambless
Luborsky et al.'s conclusion that there are no meaningful differences in the efficacy of various psychothera-pies should be reconsidered for the following reasons: (a) errors in data analysis, (b) exclusion of research on many types of clients (e.g., children and adolescents), (c) faulty generalization to comparisons between therapies that have never been made, and (d) erroneous assumption that the average difference between all sorts of treatments for all sorts of problems can be assumed to represent the difference between any two types of treatment for a given problem. Concern for clients' welfare demands that psychologists be very wary of accepting the Dodo bird verdict. [source]

Ecotourists Will Pay More,a Lot More,to See Birds

CONSERVATION, Issue 2 2006
Article first published online: 18 MAY 200
No abstract is available for this article. [source]

Characteristics of Important Stopover Locations for Migrating Birds: Remote Sensing with Radar in the Great Lakes Basin

CONSERVATION BIOLOGY, Issue 2 2009
DAVID N. BONTER
ave terrestre migratoria; migración; radar; sitios de escala temporal; WSR-88D Abstract:,A preliminary stage in developing comprehensive conservation plans involves identifying areas used by the organisms of interest. The areas used by migratory land birds during temporal breaks in migration (stopover periods) have received relatively little research and conservation attention. Methodologies for identifying stopover sites across large geographic areas have been, until recently, unavailable. Advances in weather-radar technology now allow for evaluation of bird migration patterns at large spatial scales. We analyzed radar data (WSR-88D) recorded during spring migration in 2000 and 2001 at 6 sites in the Great Lakes basin (U.S.A.). Our goal was to link areas of high migrant activity with the land-cover types and landscape contexts corresponding to those areas. To characterize the landscapes surrounding stopover locations, we integrated radar and land-cover data within a geographic information system. We compared landscape metrics within 5 km of areas that consistently hosted large numbers of migrants with landscapes surrounding randomly selected areas that were used by relatively few birds during migration. Concentration areas were characterized by 1.2 times more forest cover and 9.3 times more water cover than areas with little migrant activity. We detected a strong negative relationship between activity of migratory birds and agricultural land uses. Examination of individual migration events confirmed the importance of fragments of forested habitat in highly altered landscapes and highlighted large concentrations of birds departing from near-shore terrestrial areas in the Great Lakes basin. We conclude that conservation efforts can be more effectively targeted through intensive analysis of radar imagery. Resumen:,Una etapa preliminar en el desarrollo de planes de conservación integrales implica la identificación de áreas utilizadas por los organismos de interés. Las áreas utilizadas por aves terrestres migratorias durante escalas temporales en la migración (períodos de parada) han recibido relativamente poca atención de investigación y conservación. Hasta hace poco, las metodologías para la identificación de sitios de parada en áreas geográficas extensas han sido escasas. Ahora, los avances en la tecnología de radar meteorológico permiten la evaluación de patrones de migración de aves en escalas espaciales grandes. Analizamos datos de radar (WSR-88D) registrados en seis sitios en la cuenca de los Grandes Lagos (E.U.A.) durante la migración en las primaveras de 2000 y 2001. Nuestra meta fue relacionar áreas con gran actividad migratoria con los tipos de cobertura de suelo y los contextos del paisaje correspondientes a esas áreas. Para caracterizar los paisajes circundantes a las localidades de parada, integramos los datos de radar y de cobertura de suelo a un sistema de información geográfica. Comparamos las medidas del paisaje en un radio de 5 km en las áreas que consistentemente albergaron a grandes números de migrantes con los paisajes circundantes a áreas seleccionadas aleatoriamente y que eran utilizadas por relativamente pocas aves durante la migración. Las áreas de concentración se caracterizaron por tener 1.3 veces más cobertura forestal y 9.3 veces más cobertura de agua que las áreas con poca actividad migratoria. Detectamos una fuerte relación negativa entre la actividad de las aves migratorias y los usos de suelo agrícolas. El examen de eventos migratorios individuales confirmó la importancia de los fragmentos de hábitat boscoso en paisajes muy alterados y resaltó las grandes concentraciones de aves partiendo de áreas terrestres cercanas a la costa en la cuenca de los Grandes Lagos. Concluimos que los esfuerzos de conservación pueden ser abordados más efectivamente mediante el análisis intensivo de imágenes de radar. [source]

Effects of Economic Prosperity on Numbers of Threatened Species

CONSERVATION BIOLOGY, Issue 4 2001
Robin Naidoo
We corrected for factors that might otherwise confound such a relationship. Our study was motivated by the continuing debate over the relationship between environmental degradation and per-capita income. Proponents of the environmental Kuznets-curve hypothesis argue that although environmental degradation may increase initially, increases in per-capita income will eventually result in greater environmental quality. Theoretical objections and the lack of widespread empirical evidence recently have thrown doubt on the existence of such a pattern. Treating threat to biodiversity as one potential indicator of environmental degradation, we divided threatened species into seven taxonomic groups ( plants, mammals, birds, amphibians, reptiles, fishes, and invertebrates) and analyzed each group separately. Count-data regression analysis indicated that the number of threatened species was related to per-capita gross national product in five of seven taxonomic groups. Birds were the only taxonomic group in which numbers of threatened species decreased throughout the range of developed countries' per-capita gross national product. Plants, amphibians, reptiles, and invertebrates showed increasing numbers of threatened species throughout this same range. If these relationships hold, increasing numbers of species from several taxonomic groups are likely to be threatened with extinction as countries increase in prosperity. A key challenge is to understand the interactions among consumer preferences, biology, and institutions that lead to the relationship observed for birds and to see whether this knowledge can be applied to conservation of other taxa. Resumen: Utilizamos datos de más de 100 países para investigar la relación entre números de especies amenazadas y el producto interno bruto per cápita. Hicimos ajustes para factores que pudieran confundir tal relación. Nuestro estudio fue motivado por el continuo debate sobre la relación entre la degradación ambiental y el ingreso per cápita. Proponentes de la hipótesis de la curva ambiental de Kuznets argumentan que, aunque la degradación ambiental puede aumentar inicialmente, el incremento en el ingreso per cápita eventualmente resultará en una mejor calidad ambiental. Recientemente, objeciones teóricas y la carencia de evidencia empírica generalizada hacen dudar de la existencia de ese patrón. Tratando la amenaza a la biodiversidad como un potencial indicador de la degradación ambiental, dividimos a las especies amenazadas en siete grupos taxonómicos (plantas, mamíferos, aves, anfibios, reptiles, peces e invertebrados) y analizamos cada uno por separado. El análisis de regresión de los datos de conteo indicó que el número de especies amenazadas se relacionó con el producto interno bruto per cápita en 5 de los 7 grupos taxonómicos. Las aves fueron el único grupo en el que el número de especies amenazadas decreció a lo largo del rango del producto interno bruto per cápita de los países desarrollados. Las plantas, anfibios, reptiles e invertebrados mostraron un incremento en el número de especies amenazadas en este mismo rango. Si estas relaciones persisten, es posible que aumente el número de especies, de varios grupos taxonómicos, amenazadas de extinción a medida que los países incrementen su prosperidad. Constituye un reto clave entender las interacciones entre la preferencia de los consumidores y los factores biológicos e institucionales que conducen a la relación observada en las aves, y ver si este conocimiento puede aplicarse en la conservación de otros taxones. [source]

Aromatase expression and cell proliferation following injury of the adult zebra finch hippocampus

DEVELOPMENTAL NEUROBIOLOGY, Issue 14 2007
R. Scott Peterson
Abstract Estrogens can be neuroprotective following traumatic brain injury. Immediately after trauma to the zebra finch hippocampus, the estrogen-synthetic enzyme aromatase is rapidly upregulated in astrocytes and radial glia around the lesion site. Brain injury also induces high levels of cell proliferation. Estrogens promote neuronal differentiation, migration, and survival naturally in the avian brain. We suspect that glia are a source of estrogens promoting cell proliferation after neural injury. To explore this hypothesis, we examined the spatial and temporal relationship between glial aromatase expression and cell proliferation after neural injury in adult female zebra finches. Birds were ovariectomized and given a blank implant or one filled with estradiol; some birds were also administered an aromatase inhibitor or vehicle. All birds received penetrating injuries to the right hippocampus. Twenty-four hours after lesioning, birds were injected once with BrdU to label mitotically active cells and euthanized 2 h, 24 h, or 7 days later. The brains were processed for double-label BrdU and aromatase immunocytochemistry. Injury-induced glial aromatase expression was unaffected by survival time and aromatase inhibition. BrdU labeling was significantly reduced at 24 h by ovariectomy and by aromatase inhibition; effects were partially reversed by E2 replacement. Irrespective of ovariectomy, the densities of aromatase immunoreactive astrocytes and BrdU-labeled cells at known distances from the lesion site were highly correlated. These data suggest that injury-induced glial aromatization may influence the reorganization of injured tissue by providing a rich estrogenic environment available to influence cellular incorporation. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007. [source]

Greater hippocampal neuronal recruitment in food-storing than in non-food-storing birds

DEVELOPMENTAL NEUROBIOLOGY, Issue 4 2007
Jennifer S. Hoshooley
Abstract Previous research has shown heightened recruitment of new neurons to the chickadee hippocampus in the fall. The present study was conducted to determine whether heightened fall recruitment is associated with the seasonal onset of food-storing by comparing neurogenesis in chickadees and a non-food-storing species, the house sparrow. Chickadees and house sparrows were captured in the wild in fall and spring and received multiple injections of the cell birth marker bromodeoxyuridine (BrdU). Birds were held in captivity and the level of hippocampal neuron recruitment was assessed after 6 weeks. Chickadees showed significantly more hippocampal neuronal recruitment than house sparrows. We found no seasonal differences in hippocampal neuronal recruitment in either species. In chickadees and in house sparrows, one-third of new cells labeled for BrdU also expressed the mature neuronal protein, NeuN. In a region adjacent to the hippocampus, the hyperpallium apicale, we observed no significant differences in neuronal recruitment between species or between seasons. Hippocampal volume and total neuron number both were greater in spring than in fall in chickadees, but no seasonal differences were observed in house sparrows. Enhanced neuronal recruitment in the hippocampus of food-storing chickadees suggests a degree of neurogenic specialization that may be associated with the spatial memory requirements of food-storing behavior. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007. [source]

Social context affects testosterone-induced singing and the volume of song control nuclei in male canaries (Serinus canaria)

DEVELOPMENTAL NEUROBIOLOGY, Issue 10 2006
Géraldine Boseret
Abstract The contribution of social factors to seasonal plasticity in singing behavior and forebrain nuclei controlling song, and their interplay with gonadal steroid hormones are still poorly understood. In many songbird species, testosterone (T) enhances singing behavior but elevated plasma T concentrations are not absolutely required for singing to occur. Singing is generally produced either to defend a territory or to attract a mate and it is therefore not surprising that singing rate can be influenced by the sex and behavior of the social partner. We investigated, based on two independent experiments, the effect of the presence of a male or female partner on the rate of song produced by male canaries. In the first experiment, song rate was measured in dyads composed of one male and one female (M-F) or two males (M-M). Birds were implanted with T-filled Silastic capsules or with empty capsules as control. The number of complete song bouts produced by all males was recorded during 240 min on week 1, 2, 4, and 8 after implantation. On the day following each recording session, brains from approximately one-fourth of the birds were collected and the volumes of the song control nuclei HVC and RA were measured. T increased the singing rate and volume of HVC and RA but these effects were affected by the social context. Singing rates were higher in the M-M than in the M-F dyads. Also, in the M-M dyads a dominance-subordination relationship soon became established and dominant males sang at higher rates than subordinates in T-treated but not in control pairs. The differences in song production were not reflected in the size of the song control nuclei: HVC was larger in M-F than in M-M males and within the M-M dyads, no difference in HVC or RA size could be detected between dominant and subordinate males. At the individual level, the song rate with was positively correlated with RA and to a lower degree HVC volume, but this relationship was observed only in M-M dyads, specifically in dominant males. A second experiment, carried out with castrated males that were all treated with T and exposed either to another T-treated castrate or to an estradiol-implanted female, confirmed that song rate was higher in the M-M than in the M-F condition and that HVC volume was larger in heterosexual than in same-sex dyads. The effects of T on singing rate and on the volume of the song control nuclei are thus modulated by the social environment, including the presence/absence of a potential mate and dominance status among males. 2006 Wiley Periodicals, Inc. J Neurobiol, 2006 [source]

The role of fruit traits of bird-dispersed plants in invasiveness and weed risk assessment

DIVERSITY AND DISTRIBUTIONS, Issue 6 2009
Carl R. Gosper
Abstract Aim, Birds play a major role in the dispersal of seeds of many fleshy-fruited invasive plants. The fruits that birds choose to consume are influenced by fruit traits. However, little is known of how the traits of invasive plant fruits contribute to invasiveness or to their use by frugivores. We aim to gain a greater understanding of these relationships to improve invasive plant management. Location, South-east Queensland, Australia. Methods, We measure a variety of fruit morphology, pulp nutrient and phenology traits of a suite of bird-dispersed alien plants. Frugivore richness of these aliens was derived from the literature. Using regressions and multivariate methods, we investigate relationships between fruit traits, frugivore richness and invasiveness. Results, Plant invasiveness was negatively correlated to fruit size, and all highly invasive species had quite similar fruit morphology [smaller fruits, seeds of intermediate size and few (< 10) seeds per fruit]. Lower pulp water was the only pulp nutrient trait associated with invasiveness. There were strong positive relationships between the diversity of bird frugivores and plant invasiveness, and in the diversity of bird frugivores in the study region and another part of the plants' alien range. Main conclusions, Our results suggest that weed risk assessments (WRA) and predictions of invasive success for bird-dispersed plants can be improved. Scoring criteria for WRA regarding fruit size would need to be system-specific, depending on the fruit-processing capabilities of local frugivores. Frugivore richness could be quantified in the plant's natural range, its invasive range elsewhere, or predictions made based on functionally similar fruits. [source]

The profound influence of the Late Pliocene Panamanian uplift on the exchange, diversification, and distribution of New World birds

ECOGRAPHY, Issue 2 2010
Brian Tilston Smith
Separated throughout most of the Cenozoic era, North and South America were joined during the mid-Pliocene when the uplift of Panama formed a land bridge between these two continents. The fossil record indicates that this connection allowed an unprecedented degree of inter-continental exchange to occur between unique, previously isolated biotic assemblages, a phenomenon now recognized as the "Great American Biotic Interchange". However, a relatively poor avian fossil record has prevented our understanding the role of the land bridge in shaping New World avian communities. To address the question of avian participation in the GABI, we compiled 64 avian phylogenetic studies and applied a relaxed molecular clock to estimate the timing of trans-isthmus diversification events. Here, we show that a significant pulse of avian interchange occurred in concert with the isthmus uplift. The avian exchange was temporally consistent with the well understood mammalian interchange, despite the presumed greater vagility of birds. Birds inhabiting a variety of habitats and elevational zones responded to the newly available corridor. Within the tropics, exchange was equal in both directions although between extratropical and tropical regions it was not. Avian lineages with Nearctic origins have repeatedly invaded the tropics and radiated throughout South America; whereas, lineages with South American tropical origins remain largely restricted to the confines of the Neotropical region. This previously unrecognized pattern of asymmetric niche conservatism may represent an important and underappreciated contributor to the latitude diversity gradient. [source]

Why do mountains support so many species of birds?

ECOGRAPHY, Issue 3 2008
Adriana Ruggiero
Although topographic complexity is often associated with high bird diversity at broad geographic scales, little is known about the relative contributions of geomorphologic heterogeneity and altitudinal climatic gradients found in mountains. We analysed the birds in the western mountains of the New World to examine the two-fold effect of topography on species richness patterns, using two grains at the intercontinental extent and within temperate and tropical latitudes. Birds were also classified as montane or lowland, based on their overall distributions in the hemisphere. We estimated range in temperature within each cell and the standard deviation in elevation (topographic roughness) based on all pixels within each cell. We used path analysis to test for the independent effects of topographic roughness and temperature range on species richness while controlling for the collinearity between topographic variables. At the intercontinental extent, actual evapotranspiration (AET) was the primary driver of species richness patterns of all species taken together and of lowland species considered separately. In contrast, within-cell temperature gradients strongly influenced the richness of montane species. Regional partitioning of the data also suggested that range in temperature either by itself or acting in combination with AET had the strongest "effect" on montane bird species richness everywhere. Topographic roughness had weaker "effects" on richness variation throughout, although its positive relationship with richness increased slightly in the tropics. We conclude that bird diversity gradients in mountains primarily reflect local climatic gradients. Widespread (lowland) species and narrow-ranged (montane) species respond similarly to changes in the environment, differing only in that the richness of lowland species correlates better with broad-scale climatic effects (AET), whereas mesoscale climatic variation accounts for richness patterns of montane species. Thus, latitudinal and altitudinal gradients in species richness can be explained through similar climatic-based processes, as has long been argued. [source]