bluuebunny/crossref_metadata_2025 huggingface dataset:
Positive operators and approximation in function spaces on completely regular spaces
Authors: Altomare Francesco , Diomede Sabrina
Published: November 2003

We discuss the approximation properties of nets of positive
linear operators acting on function spaces defined on Hausdorff
completely regular spaces. A particular attention is devoted to
positive operators which are defined in terms of integrals with
respect to a given family of Borel measures. We present several
applications which, in particular, show the advantages of such a
general approach. Among other things, some new Korovkin‐type
theorems on function spaces on arbitrary topological spaces are
obtained. Finally, a natural extension of the so‐called
Bernstein‐Schnabl operators for convex (not necessarily compact)
subsets of a locally convex space is presented as well.
Duke-of-York Derivations in Polish
Authors: Rubach Jerzy
Published: November 2003

This article challenges the principle of strict parallelism in Optimality Theory by providing evidence that Duke-of-York derivations, deemed to be impossible by McCarthy (2002), exist in phonology. An analysis of two independent fragments of Polish phonology, chain shifts in velar palatalization and labial fission, shows multiple Duke-of-York effects because segment inventory constraints posit conflicting requirements for the well-formedness of outputs at different depths of derivation. It is concluded that Optimality Theory must permit constraint reranking and admit three derivational levels: two lexical levels and one postlexical level.
Closed-Form Expressions of Some Stochastic Adapting Equations for Nonlinear Adaptive Activation Function Neurons
Authors: Fiori Simone
Published: November 2003

In recent work, we introduced nonlinear adaptive activation function (FAN) artificial neuron models, which learn their activation functions in an unsupervised way by information-theoretic adapting rules. We also applied networks of these neurons to some blind signal processing problems, such as independent component analysis and blind deconvolution. The aim of this letter is to study some fundamental aspects of FAN units' learning by investigating the properties of the associated learning differential equation systems.
Evolutionary Local Search of Fuzzy Rules through a Novel Neuro-Fuzzy Encoding Method
Authors: Carrascal A. , Manrique D. , Ríos J. , Rossi C.
Published: November 2003

This paper proposes a new approach for constructing fuzzy knowledge bases using evolutionary methods. We have designed a genetic algorithm that automatically builds neuro-fuzzy architectures based on a new indirect encoding method. The neuro-fuzzy architecture represents the fuzzy knowledge base that solves a given problem; the search for this architecture takes advantage of a local search procedure that improves the chromosomes at each generation. Experiments conducted both on artificially generated and real world problems confirm the effectiveness of the proposed approach.
THE POETICS OF PERSUASION: ABŪ TAMMĀM'S PANEGYRIC TO IBN ABĪ DU ĀD
Authors: Farrin Raymond
Published: November 2003

In this article I explore the way in which an alienated and rebuffed poet might improve strained relations with his patron by means of a qasīda offering, and so obtain recompense. Taking for analysis Abū Tammām's panegyric to the judge Ibn Abī Du ād, I show how the poet tailors the tripartite pre-Islamic form to suit his individual needs. In this poem, we find Abū Tammām using the nasīb to express sorrow for the loss of the patron and to offer an indirect apology, then describing through the rahīl the privation he endured as an exile. He lauds the judge in the madīh to dispose him in his favor, but the praise gets gradually fainter as the poet becomes more assertive. He devotes most of his attention here to arguing his case, by citing precedents for magnanimity and pardon and by attributing the estrangement between them to the malice of enviers. He concludes the section by boasting of his poetic prowess, and insinuates that decorative praise could turn to withering satire if the patron does not reward him. Monetary considerations thus preponderate at the end of the qasīda , despite protestations of affection elsewhere. By illuminating Abū Tammām's subtle methods for persuading the judge, the essay increases our awareness of the poet's rhetorical skill. Furthermore, it calls attention to a latent possibility in the panegyric genre. The praise poem could well be put to uses besides celebration. The case of Abū Tammām and Ibn Abī Du ād demonstrates that a supplicant poet, before giving up on the patron and becoming hostile himself, might still exploit the form to salve old wounds and earn a prize.
The emergence and characterization of macrophage-tropic SIV/HIV chimeric viruses (SHIVs) present in CD4+ T cell-depleted rhesus monkeys
Authors: Igarashi Tatsuhiko , Imamichi Hiromi , Brown Charles R , Hirsch Vanessa M , Martin Malcolm A
Published: November 2003

Highly pathogenic simian immunodeficiency virus/human immunodeficiency virus type 1 chimeric viruses (SHIVs) induce an extremely rapid, systemic, and irreversible depletion of CD4+ T lymphocytes following their inoculation into rhesus macaques. Confocal fluorescence microscopy was used to demonstrate that high levels of viremia in infected animals were sustained by virus-producing tissue macrophage (mφ) following the irreversible elimination of CD4+ T lymphocytes by highly pathogenic SHIVDH12R. The envelope glycoproteins carried by plasma virus in CD4-depleted animals were found to contain specific alterations affecting the V2 region of gp120; similar V2 changes were observed during independent monkey infections. The altered V2 loops contained double amino acid deletions and the loss of a highly conserved N-linked glycosylation site. In contrast to the starting highly pathogenic SHIV, which is exclusively T cell-tropic, some mφ-phase SHIVs, bearing altered V2 regions, were able to establish spreading infections of cultured alveolar mφ.
Mononuclear phagocyte immunity and the neuropathogenesis of HIV-1 infection
Authors: Persidsky Yuri , Gendelman Howard E
Published: November 2003

Human immunodeficiency virus type 1 (HIV-1)-associated dementia is a neuroinflammatory brain disorder that is fueled by viral infection and immune activation of brain mononuclear phagocytes (MP; macrophages and microglia). MP serve as a reservoir for persistent viral infection, a vehicle for viral dissemination throughout the brain, and a major source of neurotoxic products that when produced in abundance, affect neuronal function. Such neurotoxic substances secreted by MP lead to clinical neurological impairment (cognitive, behavior, and motor abnormalities), which occurs usually years after the initial viral infection. How HIV-1 evades the immune function characteristic for MP as a first line of defense, including phagocytosis and intracellular killing, is not well understood despite more than two decades of study. In this report, we review the complex role(s) played by MP in the neuropathogenesis of HIV-1 infection. The clinical manifestations, pathology and pathogenesis, and treatment options are discussed in relationship to innate and adaptive immunity. Particular emphasis is given to the diversity of MP functions and how it may affect the disease process and manifestations. New insights into disease mechanisms are provided by advances in enhanced magnetic resonance imaging and proteomics to identify cell movement and genetic profiles of disease. New therapeutic strategies are discussed based on current knowledge of HIV-1-associated dementia pathogenesis.
Neural systems underlying affective disorders
Authors: Surguladze Simon , Keedwell Paul , Phillips Mary
Published: November 2003

Three main approaches are used to explore the neural correlates of mood disorder: neuropsychological studies, neuroimaging studies and post-mortem investigations. Lesion studies implicate disturbances in the frontal lobe, basal ganglia, striatum and anterior temporal cortex. Early neurocognitive and neuropathological investigations led to a ‘hypofrontality’ hypothesis of unipolar and bipolar depression, but functional neuroimaging has revealed a more complex picture. Thus,increasedmetabolism may occur in the subgenual anterior cingulate gyrus in resting-state studies of depression and sad-mood induction. Antidepressants may reduce this activity. Amygdala hyperactivation also is associated with affective disorders. Task-related studies reveal abnormal biases in memory, the experience of pleasure and the perception of emotional facial expressions. There is still little clarity whether the abnormalities in brain activation represent state or trait characteristics of affective disorders.
Psychological disturbance associated with sexual abuse in people with learning disabilities
Authors: Sequeira Heather , Howlin Patricia , Hollins Shiela
Published: November 2003

Background

The association between sexual abuse, mental health and behavioural problems in people with learning disabilities has not previously been examined in a controlled study.

Aims

To identify symptoms of psychological disturbance in adults with and without a confirmed history of sexual abuse.

Method

The study used a matched (1:1) case–control design comparing 54 adults who had experienced sexual abuse with 54 adults with no reported history of abuse. The two groups were selected from a community population of adults with learning disabilities living in residential care, and compared for selected psychiatric diagnoses and for scores on measures of disturbed behaviour.

Results

Sexual abuse was associated with increased rates of mental illness and behavioural problems, and with symptoms of post-traumatic stress. Psychological reactions to abuse were similar to those observed in the general population, but with the addition of stereotypical behaviour. The more serious the abuse, the more severe the symptoms that were reported.

Conclusions

The study provides the first evidence from a controlled study that sexual abuse is associated with a higher incidence of psychiatric and behavioural disorder in people with learning disabilities.
Capacity building through multi-disciplinary research: a report from Sri Lanka
Authors: Sumathipala Athula , Siribaddana Sisira , Samaraweera Sudath , Dayaratne D. A. R. K.
Published: November 2003

Sri Lanka is an island situated close to the southern tip of the Indian subcontinent with a land area of about 65 000 km2. The population in 2001 was 18.5 million. It has an interesting genetic diversity, its five main populations revealing both European and Asian origins. Although Sri Lanka is a developing country, it has strengths that other developing countries do not have, mainly in health and education. However, Sri Lanka lacks a research culture and has inadequacies in its research capabilities; hence, capacity building is essential. Based on our research findings, we plan to achieve this by working with professionals, statutory services, policy-makers and the public. Our model is international collaboration based on our own research agenda. Such partnerships can produce high-quality research, with greater influence on national policy and practice (Costello & Zumla, 2000).
Focus on psychiatry in France
Authors: Verdoux Hélène , Tignol Jean
Published: November 2003

The aim of this paper is to give an overview of the various facets of psychiatry in France. The selection of topics discussed, as well as the views expressed in this paper, are our own, and some of them might not reflect the views of other French psychiatrists.
Distal Radius Fractures and Concomitant Injuries: Experimental Studies Concerning Pathomechanisms
Authors: PECHLANER S. , KATHREIN A. , GABL M. , LUTZ M. , ANGERMANN P. , ZIMMERMANN R. , PEER R. , PEER S. , RIEGER M. , FREUND M. , RUDISCH A.
Published: November 2003

Since Colles’ description of the distal radius fracture (1814) and the publication by Dupuytren (1834), the frequency of this fracture, and the problems associated with it, have been increasingly recognized. Not only the treatment but also the mechanism of injury of the different types of fracture have been analysed repeatedly. The various theories concerning the pathomechanism have led to names such as “sprain fracture”, “bent fracture”, “thrust fracture”, “compression fracture”, “snap fracture” and others.

In our experimental studies, we attempted to simulate the pathomechanics of distal radius fractures, and to represent it illustratively. With the aid of a materials testing machine, 63 prepared cadaver parts were hyperextended at the wrist joint until distal radial fracture occurred. Accompanying injuries were identified radiologically and by dissection. Furthermore, the cadaver parts were deep-frozen and examined by means of computer tomography and cryo-section, using Kathrein’s method.

Through experimental hyperextension, it was possible to generate dorsal, central and palmar types of fracture. We produced 42 dorsal, 14 central and seven palmar fractures. The extent to which the carpal bones of the proximal row were pressed against the dorsal or palmar edge; or the centre of the distal radial articular surface, was fundamental. Subsequent dissection showed multiple concomitant injuries in 40 cases (63%), and none in 23 cases (37%). One reason for the occurrence of such concomitant injuries may be the relative strengths of the bone and ligaments. Most frequently (27 cases, or 43%), we found a destabilization of the triangular fibrocartilage, with or without a bony avulsion fragment (fracture of the ulnar styloid process), followed by ruptures of the interosseous ligaments between the scaphoid and the lunate (20 cases, or 32%) and between the lunate and triquetrum (11 cases, or 18%).

The application of knowledge gained from experimental studies carried out on fixed cadaver parts to clinical cases is problematic. This holds true for both concomitant injuries and fracture types.

The lack of physiological defence reflexes as well as the deliberately slowed experimental procedure must be taken into account. On the other hand, in this series of experiments it was possible to generate experimentally many of the radius fractures found in clinical practice, together with their concomitant injuries.
Comparative Evaluation of Effectiveness of Different Motor Muscles in Modified Lasso Procedure for Correction of Finger Clawing
Authors: MALAVIYA G. N.
Published: November 2003

A retrospective study was carried out to compare the effectiveness of different muscles as motors in modified lasso procedures for correction of finger clawing in leprosy. It was observed that palmaris longus and extensor carpi radialis longus were more suitable than the flexor digitorum superficialis. In some patients, removal of superficialis is associated with complications which could not be predicted before surgery. Extensor carpi radialis longus has advantages over palmaris longus in selected cases.
Lessons Learned from the Management of Complex Intra-Articular Fractures at the Base of the Middle Phalanges of Fingers
Authors: MAJUMDER S. , PECK F. , WATSON J. S. , LEES V. C.
Published: November 2003

The use of dynamic traction splintage is established in the treatment of complex intra-articular phalangeal fractures. Several different systems have been used and we report our experience with one of these, the Pins and Rubber Traction System. A cohort of 14 patients with complex intra-articular fractures at the base of the middle phalanges of the fingers were treated and assessed prospectively over a 2.5-year period (mean, 20 months; range, 7–28 months). The mean active range of motion regained, at the proximal interphalangeal joint, was 74° (range, 0–100°). The mean total active motion of the injured digit was 196° (range, 40–275°). Refinements in the regime are suggested as a result of this investigation.
Chondrosarcoma of Small Bones of the Hand
Authors: PATIL S. , DE SILVA M. V. C. , CROSSAN J. , REID R.
Published: November 2003

A clinicopathological review of 23 patients (mean age, 67 years; range, 42–85 years) with chondrosarcoma of the bones of the hand was done. The mean follow up was 8.5 years. Eleven patients presented with a progressive painless swelling, 26% having had symptoms for over 10 years. The proximal phalanx was the commonest site. Initial clinical misdiagnosis as ganglion, bursa, gout, rheumatoid arthritis and a cyst occurred in five patients. Radiologically most lesions showed bone expansion, cortical destruction and soft-tissue extension. The majority was of high histologic grade (Evan’s grade 2 & 3) with extensive myxoid areas. Five out of eight patients who were originally treated by curettage or excision had local recurrences compared to none treated by ray resection or amputation of phalanx ( P=0.002). None had metastases. The low risk of metastases despite the high histologic grade indicates that chondrosarcomas of the hand behave differently from chondrosarcomas elsewhere.
Kinematics of Ulnar Head Arthroplasty
Authors: GORDON K. D. , DUNNING C. E. , JOHNSON J. A. , KING G. J. W.
Published: November 2003

This in vitro study evaluated the performance of an ulnar head replacement. A joint simulator was employed that produced active forearm rotation in cadaveric specimens, with motion measured using an electromagnetic tracking system. The kinematics of the intact forearm were compared with a partial ulnar head replacement and a full replacement (with and without soft-tissue reconstruction) and a full excision of the ulnar head. There were no differences between intact kinematics and those following prosthetic reconstruction. However, ulnar head excision produced distal radioulnar joint instability in the form of radioulnar convergence and increased anteroposterior translations.
A Comparative Study between Longitudinal and “T” Incisions for Dorsal Plating of the Distal Radius
Authors: GANGOPADHYAY S. , PACKER G.
Published: November 2003

A retrospective review of 24 patients with dorsal incisions for open reduction and internal fixation of Frykman VII/VIII distal radius fractures using a dorsal plate was performed. Half of them had a longitudinal incision while the other half had a T-shaped incision. No difference in the healing properties or wound morbidity could be demonstrated between the two groups. However, the T incision provided improved exposure of the distal radius and patient satisfaction with its cosmetic result was superior. The horizontal limb was well camouflaged within the transverse skin crease on the dorsal aspect of the wrist. The vertical limb did not extend into the dorsum of the hand and could, therefore, be hidden by appropriate clothing.
Trigger Thumb: Results of a Prospective Randomised Study of Percutaneous Release with Steroid Injection Versus Steroid Injection Alone
Authors: MANEERIT J. , SRIWORAKUN C. , BUDHRAJA N. , NAGAVAJARA P.
Published: November 2003

One hundred and twenty-seven trigger thumbs in 115 adult patients were randomised to either percutaneous release with steroid injection ( n=66) or steroid injection alone ( n=61). Two patients, one from each group, were lost to follow-up. Percutaneous release with steroid injection produced satisfactory results in 91% of cases whereas steroid injection alone produced satisfactory results in 47% of cases. One case in the percutaneous group developed stiffness and one in the injection group developed cellulitis. No digital nerve injury occurred in either group. We conclude that percutaneous trigger thumb release combined with steroid injection has a higher success rate than that of steroid injection alone.
Suture Anchor Repair of Ulnar-Sided Triangular Fibrocartilage Complex Tears
Authors: CHOU K. H. , SARRIS I. K. , SOTEREANOS D. G.
Published: November 2003

Traditional open repair of traumatic triangular fibrocartilage complex (TFCC) tears requires a relatively extensive exposure, and arthroscopic repair, though conceptually simple, can be technically demanding. We describe a mini-open suture anchor technique that, while minimally invasive, is easier to perform than previously described open or arthroscopic techniques. Results achieved using this technique in eight cases compare favourably with those reported for other techniques.
Skin Tension in the Aetiology of Dupuytren’s Disease; a Prospective Trial
Authors: CITRON N. , HEARNDEN A.
Published: November 2003

Tension in the palmar fascia has been proposed as a factor causing Dupuytren’s disease. If tension does stimulate the growth of new Dupuytren’s tissue, relieving longitudinal tension should reduce the recurrence rate following surgery. Thirty patients with palmar Dupuytren’s contracture of a single ray that affected only the metacarpophalangeal joint were divided into two groups. Both groups had a fasciotomy: one group through a transverse incision that was closed directly and the other through a longitudinal incision with Z-plasty closure. Half the patients (seven of 14) who had direct closure had recurrence at 2 years as compared to two of the 13 in the Z-plasty group. The trial was stopped at the interim analysis stage due to the high recurrence rate in the first group. These results are consistent with the tension hypothesis for the aetiology of Dupuytren’s disease.
Fine Needle Aspiration Cytology for Soft Tissue Tumours of the Hand
Authors: KITAGAWA Y. , ITO H. , SAWAIZUMI T. , MATSUBARA M. , YOKOYAMA M. , NAITO Z.
Published: November 2003

The purpose of this study was to evaluate the usefulness of fine needle aspiration cytology for the preoperative diagnosis of soft tissue tumours of the hand. Fine needle aspiration cytology was performed on 93 soft tissue tumours of the hand which were classified as malignant, benign or unclassified based on cytological findings. We also attempted to make specific diagnosis by cytology. The cytological diagnosis was then compared with the postoperative histopathological diagnosis. The cytological differentiation between benign and malignant tumours showed neither false-positive nor false-negative results. Of the 47 lesions with sufficient material for cytology and that were postoperatively diagnosed histologically, 35 (including one recurrent lesion) were correctly diagnosed by fine needle aspiration cytology. No complications were encountered. Fine needle aspiration cytology has a high degree of diagnostic accuracy and safety for soft tissue tumours of the hand.
Intermittent signature of ENSO in west‐Antarctic precipitation
Authors: Genthon Christophe , Cosme Emmanuel
Published: November 2003

Precipitation data from the new ERA40 reanalyses and from a 200‐year simulation confirm a robust main mode of precipitation variability in west Antarctica. An intermittently strong ENSO signature is found in this mode. However, high correlation with ENSO indices appears infrequent. Thus, the high correlation found in ERA40, and previously in other chronologically realistic data, in the late 1980s and the 1990s may not be expected to last. Unlike previously suggested by others, the sign of the correlation between ENSO indices and west Antarctic precipitation, when significant, does not appear to change in time: Precipitation variability at the ENSO pace in the Bellingshausen‐Weddell (Ross‐Amunsden) region is consistently in phase (phase opposition, respectively) with the Southern Oscillation Index. This is consistent with a tropospheric wave train connecting the tropical Pacific and west Antarctic regions, which modulates in phase opposition the advection of air and moisture in the 2 regions.
Global‐scale simulation of foreshock structures at the quasi‐parallel bow shock
Authors: Lin Y.
Published: November 2003

A two‐dimensional, global‐scale hybrid simulation is carried out to study the kinetic structure of the quasi‐parallel bow shock. In the simulation the bow shock forms by the interaction of the supersonic solar wind and the geomagnetic field. Strong temporal electromagnetic waves occur in the shock transition and foreshock regions due to backstreaming and reflected ions at the bow shock. This self‐consistent, global‐scale simulation shows the formation of diamagnetic cavities in the foreshock regions of the parallel and quasi‐parallel shocks, where ion beams interact with the incoming solar wind plasma. The cavities are crater‐like and saturate at a width ∼1–2 RE, with a low‐density and low‐magnetic field center bounded by a rim of high density and high magnetic field. The bulk flow speed decreases slightly in the center of the cavity, while the ion temperature often, but not always, increases. The craters convect downstream with the solar wind flow. When the interplanetary magnetic field (IMF) lies nearly parallel to the solar wind flow, the craters develop into elongated phase‐standing spatial structures along the field lines, both upstream and downstream, with alternate increases and decreases in the density and corresponding in‐phase variations in the magnetic field strength. In the general cases with an oblique IMF the foreshock cavities can convect toward the Earth as transient compressional structures and impinge on the magnetopause. The generation and structure of the diamagnetic cavities are compared with those of hot flow anomalies. The simulation results are also compared with satellite observations of the foreshock of quasi‐parallel shocks.
Thermal Emission Imaging System (THEMIS) infrared observations of atmospheric dust and water ice cloud optical depth
Authors: Smith Michael D. , Bandfield Joshua L. , Christensen Philip R. , Richardson Mark I.
Published: November 2003

The Mars Odyssey spacecraft entered into Martian orbit in October 2001 and after successful aerobraking, began mapping in February 2002. Thermal infrared images taken by the Thermal Emission Imaging System (THEMIS) on board the Odyssey spacecraft allow for the quantitative retrieval of atmospheric dust and water ice aerosol optical depth. Data collected so far cover late northern winter, spring, and summer (Ls = 330°–160°). During this period, THEMIS observed the decay of a regional dust storm, a number of local dust storms along the edge of the retreating north polar cap, and the growth of the low‐latitude aphelion water ice cloud belt. Data from THEMIS complements the concurrent Mars Global Surveyor Thermal Emission Spectrometer (TES) data by sampling a later local time (∼1400 LT for TES versus ∼1600–1730 LT for THEMIS) and by observing at much higher spatial resolution. Comparison of water ice optical depth in the aphelion cloud belt from THEMIS and TES shows a significantly higher optical depth in the late afternoon (THEMIS) than in the early afternoon (TES).
Absence of extra‐pair fertilisations in the Chinstrap Penguin Pygoscelis antarctica
Authors: Moreno J. , Boto L. , Fargallo J. A. , De León A. , Potti J.
Published: November 2003

We analysed genetic relatedness through DNA‐fingerprinting in 38 two‐chick families of Chinstrap Penguins Pygoscelis antarctica in the Vapour Col colony on Deception Island, Antarctica. Band‐sharing coefficients between males and chicks in their nests, females and chicks in their nests and brood mates were very close to 0.50 and were not significantly different. Presumably unrelated pair mates showed much lower band‐sharing coefficients (0.12), which differed significantly from those between putative parents and their chicks and between presumed siblings. No case of extra‐pair paternity was detected according to the presence of novel bands or to band‐sharing coefficients. Monogamy in the study population is not only social but also genetic.
Intrinsic aging‐related mortality in birds
Authors: Ricklefs Robert E.
Published: November 2003

Actuarial senescence in captive populations of 28 species of bird was quantified by estimating the parameters of Weibull models fitted to survival curves constructed from data obtained from zoos. Samples of natural and captive populations were compared using phylogenetically independent contrasts, which revealed that extrinsic mortality rates in captive populations are, on average, less than 30% of those of natural populations but that the component of mortality related to aging does not differ significantly between natural and captive birds. This result supports the hypothesis that aging‐related mortality is associated with intrinsic causes of death that kill independently of the external environment. A logical implication of this result is that birds in natural populations maintain a high level of physical fitness into old age and do not become more vulnerable to extrinsic mortality factors with increasing age. Additional comparisons showed that the rate of aging in this sample of birds is correlated with body mass, but not with embryonic or postnatal growth rate. These analyses suggest that studies of aging in captive populations can provide powerful tools to help us understand senescence in natural populations.
Copulation exposes female Red‐winged Blackbirds to bacteria in male semen
Authors: Westneat David F. , Birch Rambo T.
Published: November 2003

One often cited but poorly studied cost of multiple mating by female birds is the risk of acquiring sexually transmitted pathogens. We examined the ejaculates of male Red‐winged Blackbirds Agelaius
phoeniceus to determine if exposure to bacteria from males was a potential consequence of copulation for females. Ejaculates were collected in the field using a model female fitted with a sterile artificial cloaca. We found that 11 of 18 sampled males left ejaculates containing bacteria (compared to 3 of 18 control swabs of a sterile cloaca similarly exposed to the environment). We could identify to species or genus 13 of 26 isolates of bacteria from ejaculates, and found that each male left a unique combination of types. Only three types were found in more than one male (one additional male in each case). We found no qualitative effects of bacterial contamination on male fertility or female reproductive success, but larger sample sizes would be needed for a quantitative analysis. Little information is available on how the strains we identified might affect birds, but several types have known debilitating effects in humans or domesticated mammals. Two bacterial types isolated from blackbird semen are reported to produce chitinase, an enzyme with possibly beneficial consequences if produced by bacteria entering the gut of an insect‐eating bird. These results suggest that exposure to new bacterial types is a consequence of extra‐pair copulations to females. This exposure could have beneficial and/or detrimental effects on female fitness.
Long‐range call use in dominance‐structured Crested Tit Parus cristatus winter groups
Authors: Krams Indriķis
Published: November 2003

In this study on free‐ranging Crested Tits Parus cristatus, I examine the relationship between social dominance and the frequency of use of long‐range communication calls. Calling rates of trills were highest among socially dominant individuals and they gave more calls when close to the boundary of their territories. Dominant females uttered fewer calls than their mates. However, they gave significantly more calls than subordinate males and subordinate females, the latter calling least. A removal and playback experiment revealed a relationship between the utterance of trilled calls and the defence of the winter territory in the Crested Tit. Although territorial vocalizations could incur costs, territorial individuals may gain from improved winter survival by decreasing the risk of food stealing by Crested Tits from adjacent territories.
Predation risk associated with nesting in gull colonies by two Aythya species: observations and an experimental test
Authors: Väänänen Veli‐Matti
Published: November 2003

To reduce nest predation certain duck species nest in association with more aggressive species. For instance, Pochard Aythya ferina and
Tufted Duck Aythya fuligula often nest in association with small
larids, such as the Black‐headed Gull Larus ridibundus. I studied nest predation, nesting association and nest site requirements of Pochard and Tufted Duck in central Finland (63°N, 27°E) observing natural and artifical nests. Predation of Pochard and Tufted Duck nests was of similar extent and stronger outside than within gull colonies. An experiment with artficial nests also showed that a higher proportion of nests was preyed upon outside than within gull colonies (0.98 and 0.13, respectively). The results are consistent with the hypothesis that nest predation is lower within than outside gull colonies. Tufted Ducks nest more often with gulls than do Pochards; 61.5% of Tufted Duck nests and 29.3% of Pochard nests were found within gull colonies.
A comparative study of digestion in North Atlantic seabirds
Authors: Hilton Geoff M. , Furness Robert W. , Houston David C.
Published: November 2003

We present data on digestive efficiencies and gut retention times of eight North Atlantic seabird species, fed on two fish species – lesser sandeel Ammodytes marinus and whiting Merlangius
merlangus– which commonly occur in the diet of wild seabirds. In an interspecific comparison, there was a positive relationship between retention time and digestive efficiency, which we suggest represents a trade‐off between conflicting benefits of efficient digestion and rapid digestion. Analysis of excretion curves revealed that retention time of digesta in the stomach was more important than passage time of digesta through the intestine in determining whole gut retention time. Differences in stomach retention time of lesser sandeel and whiting explained the longer overall retention time of the latter diet. Stomach retention time and whole gut retention time were greater in species with relatively large stomachs, while intestine passage time was correlated with relative intestine length. Species which typically eat a wide range of food types, including low quality items, tended to have slow and efficient digestion and heavy stomachs, whereas species which specialise on readily digestible and energy dense food types had the opposite digestion strategy.
Compensatory frugivory in migratory Sylvia warblers: geographical responses to season length
Authors: Eggers Sönke
Published: November 2003

Seasonal shifts in the diets of Garden Warblers Sylvia borin,
Blackcaps S. atricapilla and Lesser Whitethroats S. curruca
at a North German site were studied from samples obtained by flushing the
digestive tract of the birds. The significance of seven species of
berries and pulpy fruits in the diet of these species while feeding in
riparian vegetation during the premigratory and migratory seasons was
assessed and compared with the pattern of frugivory shown by the same
species in southern Germany. Because of the short time span between
hatching and onset of migration, first‐year long‐ and medium‐distance
migratory Sylvia warblers from northern Europe are forced to
accelerate their juvenile development. Presumably to meet the higher
nutritional demands of an accelerated development, juvenile Garden
Warblers and Blackcaps in northern Germany ate relatively more fruit
during premigration than Blackcaps in southern Germany. Fruit occurred in
about 90% of their diet samples during both premigration and migration.
However, this might not hold true for experienced adult birds. Garden
Warblers accelerated the rate of fattening and reduced the time needed to
prepare for migration when feeding on a mixed fruit diet. There were
indications that Blackcaps directly influenced the fruit choice of Garden
Warblers when fruits preferred by both species were scarce. Blackcaps and
Garden Warblers showed subtle differences in their seasonal preferences
for black elder Sambucus nigra and woody nightshade Solanum
dulcamara.
Tissue mass dynamics during egg‐production in female Zebra Finches Taeniopygia guttata: dietary and hormonal manipulations
Authors: Williams Tony D. , Martyniuk Christopher J.
Published: November 2003

Changes in tissue masses associated with egg production were investigated in female Zebra Finches Taeniopygia gutatta using dietary and hormonal manipulations. We tested three hypotheses: that changes in organ masses, (a) reflect utilisation of endogenous nutrient stores due to inadequate daily dietary intake, (b) involve changes in organ structure or ‘functional capacity’, and (c) are initiated by onset of reproductive development (e.g. elevated plasma estrogen or yolk precursor levels, oviduct growth). Pectoral muscle lean dry mass was 18–22% lower in breeding females at the 1‐egg stage compared to non‐breeders, and this was independent of nutritional plane, i.e. similar changes occurred in birds provided with supplemental protein or egg food. Heart lean dry mass was also lower (16%) in breeding females, but only in birds on a low‐quality seed diet, not in birds on supplemented diets. Decreases in total liver mass (14%) were due to changes in lipid content not lean dry mass, and were diet‐dependent. These results demonstrate that changes in organ masses associated with egg production are complex, and do not simply reflect a general mobilisation of stored protein. We discuss why there is no hypertrophy of biosynthetic or metabolic ‘machinery’ associated with egg production in birds (cf. reproducing mammals). Exogenous 17β‐estradiol induced plasma levels of yolk precursors typical of breeding birds, and initiated oviduct growth (to 31% of mature size). However, estradiol treatment caused no change in mass of pectoral muscle, heart or liver, demonstrating that there is no simple relationship between onset of reproductive development and associated tissue mass changes.
Responses to playback of different subspecies songs in the Reed Bunting Emberiza schoeniclus
Authors: Matessi Giuliano , Dabelsteen Torben , Pilastro Andrea
Published: November 2003

Populations of Reed Buntings Emberiza schoeniclus in the
western Palearctic are classified in two major subspecies groups
according to morphology: northern migratory schoeniclus and
Mediterranean resident intermedia. Songs of the two groups differ
mainly in complexity and syllable structure, with intermedia songs
being more complex. We explored the possibilities of song as a subspecies
isolating mechanism by testing if male schoeniclus Reed Buntings
reacted differently to field playbacks of songs from their own subspecies
group, from the foreign subspecies group and from a control species, the
Yellowhammer Emberiza citrinella. We tested 30 different males, each with a different song belonging to one of the three categories: own, foreign and Yellowhammer. Unlike songs of the two subspecies groups, Yellowhammer song elicited no response. Differences between reactions to own and foreign subspecies group songs were not significant, even though differences in response type (singing vs approaching) suggested some degree of uncertainty in classification of foreign song. We conclude from these results that the subspecies may be only in the first stages of the isolation process.
The evolution of cooperative and pair breeding in thornbills Acanthiza (Pardalotidae)
Authors: Nicholls James A. , Double Michael C. , Rowell David M. , Magrath Robert D.
Published: November 2003

Most birds breed in pairs but at least 3% of passerine species are cooperative breeders, whereby more than two adults help to raise the young. The general rarity of cooperative breeding has led to the assumption that cooperative behaviour has evolved from the ancestral trait of pair breeding. However, it has been suggested that pair breeding may be the derived state in some taxa. The primary aim of this research was to test this suggestion using the genus Acanthiza, which
contains examples of both cooperatively and pair breeding species.
Mitochondrial DNA sequences were used to construct a phylogenetic
hypothesis for the tribe containing Acanthiza, the Acanthizini.
The breeding behaviour of the species sequenced was determined from
records in the literature; where there were no such data the frequency of
another social behaviour, flocking, was used as an indicator of breeding
behaviour. The mapping of breeding systems onto the phylogeny led to the
conclusion that cooperative breeding is the ancestral state in the
Acanthizini, with pair breeding evolving twice in the genus
Acanthiza. Models explaining the occurrence of cooperative
breeding in terms of broad environmental factors or life history do not
appear to be applicable to the genus Acanthiza. The pair breeding
Acanthiza species cluster into two clades, suggesting some influence of phylogenetic history on the occurrence of the different breeding systems. Combining the results of this study with other data suggests the tendency to breed cooperatively could be ancestral in the superfamily Meliphagoidea.
Mate provisioning, nutritional requirements for egg production, and primary reproductive effort of female Common Terns Sterna hirundo
Authors: Moore David J. , Williams Tony D. , Morris Ralph D.
Published: November 2003

We assessed the nutritional importance of mate provisioning to females during egg production and its effects on clutch parameters (egg size, length of the laying period) in Common Terns Sterna hirundo: (1)
we estimated the costs of egg production by modeling the daily protein,
lipid, and energy requirements of laying females, and (2) compared these
costs to both the amount, and the timing, of the male's contribution
via mate provisioning. Net lipid, net protein, and gross energy
requirements for a three‐egg clutch were estimated to be 5.4 g, 8.6 g,
and 569 kJ respectively. Peak protein and lipid requirements occurred one
(day −1) and two (day −2) days before laying, respectively.
Peak energy requirement occurred on day −1; a cost of 127% to 157%
above maintenance. Variation in male provisioning effort (in terms of
energy and nutrients delivered) paralleled variation in predicted female
requirements for egg production at the level of individual pairs. Males
delivered protein in excess of the female's requirements on all days
investigated. Male lipid delivery accounted for 45% of female net
requirement on the day when demand was greatest (day −2), but
exceeded requirements on all other days. However, the proportion of the
female's total energy budget (egg production, maintenance, and
activity costs) that was supplied by her mate rose from an average of 29%
on day −2 to 76% during the interval between second and third eggs.
Paradoxically, females that were fed at higher rates during the interval
between first and second eggs produced clutches with lower total
volumes, smaller last‐laid eggs, and clutches with a greater
egg‐size hierarchy than conspecifics receiving less food from their
mates. Also, females fed at higher rates during the interval between
second and third eggs took longer to produce their clutch. These
negative relationships between mate provisioning and clutch parameters contrast with previous studies in this and other species.
Flight speeds and climb rates of Brent Geese: mass‐dependent differences between spring and autumn migration
Authors: Green Martin , Alerstam Thomas
Published: November 2003

Aerodynamic theories of bird flight predict that horizontal flight speed will increase with increasing load whereas vertical flight speed will decrease. Horizontal flight speed for birds minimizing overall time on migration is predicted to be higher than flight speed for birds minimizing energy expenditure. In this study we compare flight speeds of Brent Geese Branta b. bernicla recorded by tracking radar and
optical range finder during spring and autumn migration in southernmost
Sweden, testing the above‐mentioned predictions. Geese passing Sweden in
spring are substantially heavier than in autumn and there might also be a
stronger element of time‐selection in spring than in autumn. Recorded
airspeeds were significantly higher in spring (mean 19.0 m
s−1) than in autumn (mean 17.3 m s−1), the average difference being slightly larger than predicted due to the mass difference alone. The effects on airspeed of wind, vertical speed, flock size and altitude were also analysed, but none of these factors could explain the seasonal difference in airspeed. Hence, the results support the hypothesis of mass‐dependent flight speed adjustment. The difference between the two seasons was not large enough to corroborate the hypothesis of a stronger element of time‐selection in spring, but this hypothesis cannot be rejected. Vertical flight speeds were lower in spring than in autumn, supporting a negative effect of load on birds’ flight power margin.
When heavier birds lose more mass during breeding: statistical artefact or biologically meaningful?
Authors: Gebhardt‐Henrich Sabine G.
Published: November 2003

Several studies on mass loss during breeding in female birds have shown a significant correlation between initial body mass and subsequent loss of body mass. The significant positive regression coefficient of mass loss on initial mass was interpreted as evidence for a greater mass loss of initially heavier birds. However, the positive correlation between mass loss and initial mass arises automatically even when initial and final body masses are uncorrelated and has no necessary biological meaning. This is shown analytically here. In general, a spurious correlation arises when one variable (e.g. mass loss) is part of
another variable (e.g. initial mass) and then regressed on it.
Reproductive skew in birds: models, problems and prospects
Authors: Magrath Robert D. , Heinsohn Robert G.
Published: November 2003

In recent years there has been a resurgence of interest in models to explain the partitioning of direct reproduction (‘reproductive skew’) among members of one sex within social groups. We review models of skew, identify problems of testing models, and consider how to make progress. One series of models assumes that dominants have complete control of subordinate reproduction, but may allow subordinates some reproduction as a way of enticing them to help or getting them to share the cost of reproduction. Another series of models assume that dominants have limited control of subordinate reproduction. Reproductive skew may also be affected by incest avoidance or control by the opposite sex. Models are largely untested because no study of birds has quantified all relevant parameters, and we see no prospect of this happening soon. A common simplifying approach is to test qualitative predictions about the effect on skew of relatedness among group members. However, these data alone cannot distinguish among models because models do not make unique predictions, partly because skew is also affected by other factors. A major problem in cooperatively‐breeding birds is that any effect of relatedness will often be confounded by covariation with relatedness asymmetry and subordinate competitiveness. Progress can be made with the development of theory, controlling confounding variables through the choice of study species or types of social group, and, most importantly, testing assumptions underlying hypotheses.
Parental defence in Long‐eared Owls Asio otus: effects of breeding stage, parent sex and human persecution
Authors: Galeotti Paolo , Tavecchia Giacomo , Bonetti Andrea
Published: November 2003

The responses of male and female Long‐eared Owls to a human approaching the nest were examined. Each nest was only tested once. Nest defence increased significantly throughout the breeding season because older chicks were defended more strongly than younger chicks and eggs. No correlations were however found between defence intensity and laying date, clutch‐ or brood‐size. These results generally do not support either the renesting‐potential hypothesis or the positive reinforcement hypothesis but are in accordance with both the age‐investment hypothesis and the vulnerability hypothesis. Females defended nestlings more often and more vigorously than did males. Given division of labour between sexes and the related reversed sexual dimorphism in size, female Long‐eared Owls may be more willing to engage in nest defence simply because they are always nearer eggs and chicks during all breeding stages and are larger/heavier than males; consequently they may allocate more time and energy to this activity. Finally, owls experiencing higher levels of human persecution took smaller risks when defending nests than owls breeding in an undisturbed area.