bluuebunny/crossref_metadata_2025 huggingface dataset:
Escherichia coli O157[ratio ]H7 infection of calves: infectious dose and direct contact transmission
Authors: BESSER T. E. , RICHARDS B. L. , RICE D. H. , HANCOCK D. D.
Published: October 2003

Cattle are considered to be a reservoir host of Escherichia coli O157[ratio ]H7 and contaminated foods of bovine origin are important vehicles of human infection. In this study, the susceptibility of calves to experimental E. coli O157[ratio ]H7 infection following low oral exposures was determined. Two of 17 calves exposed to very low (<300 c.f.u.) doses, and 3 of 4 calves exposed to low (<10000 c.f.u.) doses, subsequently excreted the challenge strains in their faeces. All calves (n = 12) sharing isolation rooms with calves that excreted the challenge strain in their faeces similarly began faecal excretion of the same strains within 21 days or less. The identity between the challenge strains and the strains excreted in calf faeces was confirmed by restriction digestion electrophoretic patterns using pulsed field gel electrophoresis. Calves shed E. coli O157[ratio ]H7 in their faeces after very low dose exposures at concentrations ranging from <30 to >107 c.f.u./g, and for durations similar to the values previously reported for calves challenged by larger doses. The susceptibility of calves to infection following very low exposures or direct contact with infected calves has important implications for programmes for pre-harvest control of this agent.
Immunogenicity and reactogenicity of the adult tetanus–diphtheria vaccine. How many doses are necessary?
Authors: BAYAS J. M. , VILELLA A. , BERTRAN M. J. , VIDAL J. , BATALLA J. , ASENJO M. A. , SALLERAS L. L.
Published: October 2003

The immunogenicity and reactogenicity of the tetanus–diphtheria adult type vaccine was compared in two groups: group I (n = 201, 18–30 years old, presumably vaccinated with the DTP vaccine) and group II (n = 147, [ges ] 45 years old, without vaccination antecedents). Before vaccination, the seroprotection levels for tetanus were 90·5% (group I) and 30·6% (group II). These rose to 99·5% and 81·7%, respectively, after administration of one vaccine dose. For diphtheria, prevaccination seroprotection levels were 38·3% (group I) and 19·0% (group II). These rose to 85·8% and 65·7%, respectively, after vaccination. The logistic regression analysis showed an association between antibody titre and age. In group II, 3 doses of Td vaccine were needed to reach titres similar to those achieved in group I with a single dose. Stated reactogenicity was greater in: young subjects, women, those with higher titres of tetanus antibodies and those receiving other vaccines simultaneously. These results confirm the need for vaccination schedules adapted to the characteristics of each population age-group.
Genealogical analyses of rabies virus strains from Brazil based on N gene alleles
Authors: HEINEMANN M. B. , FERNANDES-MATIOLI F. M. C. , CORTEZ A. , SOARES R. M. , SAKAMOTO S. M. , BERNARDI F. , ITO F. H. , MADEIRA A. M. B. N. , RICHTZENHAIN L. J.
Published: October 2003

Thirty rabies virus isolates from cows and vampire bats from different regions of São Paulo State, Southeastern Brazil and three rabies vaccines were studied genetically. The analysis was based on direct sequencing of PCR-amplified products of 600 nucleotides coding for the amino terminus of nucleoprotein gene. The sequences were checked to verify their genealogical and evolutionary relationships and possible implication for health programmes. Statistical data indicated that there were no significant genetic differences between samples isolated from distinct hosts, from different geographical regions and between samples collected in the last two decades. According to the HKA test, the variability observed in the sequences is probably due to genetic drift. Since changes in genetic material may produce modifications in the protein responsible for immunogenicity of virus, which may eventually cause vaccine failure in herds, we suggest that continuous efforts in monitoring genetic diversity in rabies virus field strains, in relation to vaccine strains, must be conducted.
Epidemiology of hepatitis B infection among the Nicobarese – a mongoloid tribe of the Andaman and Nicobar Islands, India
Authors: MURHEKAR M. V. , MURHEKAR K. M. , ARANKALLE V. A. , SEHGAL S. C.
Published: October 2003

Andaman and Nicobar Islands, Union Territory of India, is home to six primitive tribes. Preliminary serological studies carried out earlier among the four accessible tribes revealed that hepatitis B virus (HBV) infection is hyper-endemic among them. The present study was carried out to understand important modes of transmission and to identify possible risk factors associated with HBV infection among the Nicobarese tribe. The epidemiology of HBV infection in these islands appears to be distinct with a high prevalence of the chronic carrier state (22·2%) associated with a comparable proportion of the population being anti-HBs positive (26·3%). More than half of the HBsAg and anti-HBs negative individuals have anti-HBc antibodies. Age, past history of hospital admission, intramuscular injections and number of carriers in the tuhet were found to be significantly associated with exposure to hepatitis B virus. Horizontal transmission through close contact with carriers and perinatal route appears to be an important mode of transmission of HBV in this community. Besides this, use of unsafe injections represents an independent risk factor for acquiring HBV infection in this population. Introducing HBV vaccine in the infant immunization programme and improving injection safety would help to control the infection in the tribal community of these islands.
Spread of Staphylococcus aureus resistant to penicillin and tetracycline within and between dairy herds
Authors: WAAGE S. , BJORLAND J. , CAUGANT D. A. , OPPEGAARD H. , TOLLERSRUD T. , MØRK T. , AARESTRUP F. M.
Published: October 2003

One hundred and seven bovine isolates of penicillin and tetracycline resistant Staphylococcus aureus, recovered from 25 different dairy herds in various parts of Norway, were characterized using antimicrobial susceptibility testing, multilocus enzyme electrophoresis, ribotyping, plasmid analysis and serotyping of capsular polysaccharide. Forty-one isolates from one particular herd, 37 isolates from 5 herds that used a common pasture and milking parlour in summer and 21 isolates from 12 herds in 8 different counties belonged to the same strain. The remaining 8 isolates, which originated from herds in 5 different counties, were assigned to 6 different strains. Seven out of these 8 isolates had the same plasmid restriction profile. In conclusion, penicillin and tetracycline resistant S. aureus occurring in dairy herds in Norway mainly seems to represent one particular strain that has achieved widespread distribution or belong to one of several different strains carrying identical plasmids.
Contribution of RSV to bronchiolitis and pneumonia-associated hospitalizations in English children, April 1995–March 1998
Authors: MÜLLER-PEBODY B. , EDMUNDS W. J. , ZAMBON M. C. , GAY N. J. , CROWCROFT N. S.
Published: October 2003

Estimates of the number of hospitalizations attributable to specific pathogens are required to predict the potential impact of vaccination. All hospital admissions for lower respiratory tract infection (LRI) in children <5 years in England in 1995–8 were reviewed. Most admissions (76.8%) were not associated with specific organisms. Seasonality in pathogens that cause bronchiolitis and pneumonia was used to predict the proportion of cases with unspecified aetiology attributable to different organisms using multiple linear regression. Of 12298 admissions for LRI, 17.5% were due to RSV infection. An estimated 74.8% (95% CI, 72.0–77.7%) of ‘unspecified bronchiolitis’ admissions and 16.3% (95% CI, 13.7–18.8%) of ‘unspecified pneumonia’ admissions were RSV related. The total mean annual incidence of hospital admissions attributable to RSV is 28.3/1000 children <1 year of age, and 1.3/1000 children 1–4 years old. The greater burden of RSV infection than indicated through discharge data is revealed through applying simple statistical methods.
Comparison between cohorts vaccinated and unvaccinated against influenza and pneumococcal infection
Authors: CHRISTENSON B. , LUNDBERGH P.
Published: October 2003

This study characterizes possible confounders that might make cohorts vaccinated and unvaccinated against influenza and pneumococcal infection different at baseline, with the hypothesis that the two cohorts are comparable. The similarity between health and demographic data was analysed by a randomized, multivariant study addressed to 10 000 persons aged 65 years and older in Stockholm County and was carried out in the form of a postal inquiry during the period December 2000 to May 2001. The study-population response rate was 78%. Of these, 66% (5120 persons) had been given at least one influenza vaccination during the 3-year study period (1998–2000), 50% (3780) had received one pneumococcal vaccination and 78% had received both vaccines during the period. The vaccination rate was lower in the age group 65–69 years (60%), compared with elderly cohorts aged over 70 years (67–72%, P<0·001). Elderly persons living in nursing homes or institutions had higher vaccination rates than persons living in their own households (72 vs. 67%). Persons with underlying chronic diseases had higher vaccination rates (71%, P<0·001) than those without underlying chronic diseases. Vaccine recipients had fewer days in hospital, compared with non-recipients. Unvaccinated persons with myocardial disease had nine times more days in hospital than vaccinated persons with myocardial disease. Vaccination against pneumococcal infection had an additional effect with influenza vaccination in reducing hospitalization for chronic lung diseases; influenza vaccination alone did not have this effect. In conclusion, the influenza and pneumococcal-vaccine recipients were older and had significantly more chronic lung and heart conditions than the unvaccinated cohort.
Epidemiol. Infect.127 (2001), 221–7 An outbreak of diarrhoea due to multiple antimicrobial-resistant
Shiga toxin-producing Escherichia coli O26: H11 in a nursery
Authors: HIRUTA N. , MURASE T. , OKAMURA N.
Published: October 2003

Page 223, Table 1. ‘V2 GACTGCGTCAGTGAGGTT’

Should read ‘V5 GACTCTTCCATCTGCCG’

Page 226, Reference 1. ‘1997’ should read ‘1977’

Page 227, Reference 17. Replace with ‘Kobayashi K. Detection of
enterohemorrhagic Escherichia coli using PCR. J Clin Microbiol
1991; 18: 507–13.’
A major methicillin-resistant Staphylococcus aureus clone predominates in Malaysian hospitals
Authors: NORAZAH A. , LIM V. K. E. , ROHANI M. Y. , ALFIZAH H. , KOH Y. T. , KAMEL A. G. M.
Published: October 2003

This study was conducted to determine the molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in Malaysian hospitals. A total of 264 MRSA isolates from eight hospitals were subjected to typing by pulsed-field gel electrophoresis (PFGE) of SmaI restricted DNA. Antibiotic disk susceptibility testing was also carried out to determine their resistance patterns. Thirty-one PFGE pattern types were identified. Three major pattern types A, ZC and K were found with type A the predominant profile in c. 80% of strains and present in all hospitals. Unlike type A, other DNA pattern types were unique to the hospitals in which they were isolated. PFGE type A also consisted of strains that were multiply antibiotic resistant. The presence of a single predominant PFGE type in Malaysian hospitals is an important finding which suggests that inter-hospital spread of MRSA had occurred frequently and regularly.
Genotypes of hepatitis C virus circulating in Tunisia
Authors: DJEBBI A. , TRIKI H. , BAHRI O. , CHEIKH I. , SADRAOUI A. , BEN AMMAR A. , DELLAGI K.
Published: October 2003

Hepatitis C virus (HCV) isolates from 93 patients living in Tunisia, including 16 haemophiliacs, were genotyped by INNO LiPA and partial sequencing of the 5′ untranslated region of the viral genome. In non-haemophiliacs, subtype 1b was largely predominant (79%), types 1a, 2a, 2b, 3a and 4a occurred much less frequently at 5, 7, 3, 3 and 1% of cases, respectively. In the group of haemophiliacs, a co-dominance between subtypes 1a and 1b was noticed (38%). Type distribution of HCV in Tunisia differs from that reported in other countries of the Mediterranean and Middle East regions. Genotyping results in respect of clinical status, age, and genotyping methods, are discussed.
Disruption of transient photoreceptor targeting within the
inner plexiform layer following early ablation of cholinergic
amacrine cells in the ferret
Authors: JOHNSON P.T. , RAVEN M.A. , REESE B.E.
Published: October 2003

Photoreceptors in the ferret's retina have been shown
to project transiently to the inner plexiform layer (IPL) prior
to their differentiation of an outer segment. On postnatal day
15 (P-15), when this projection achieves maximal density, the
photoreceptors projecting into the IPL extend primarily to one
of two depths, coincident with the processes of cholinergic
amacrine cells. The present study has used an excitotoxic approach
employing subcutaneous injections of l-glutamate to
ablate these cholinergic amacrine cells on P-7, in order to
see whether their elimination alters this targeting of
photoreceptor terminals within the IPL. The near-complete
elimination of cholinergic amacrine cells at P-15 was confirmed,
although the population of retinal ganglion cells was also
affected, being depleted by roughly 50%. The rod
opsin-immunopositive terminals in such treated ferrets no longer
showed a stratified distribution, being found throughout the
depth of the IPL, as well as extending into the ganglion cell
layer. This effect should not be due to the partial loss of
retinal ganglion cells, however, since optic nerve transection
at P-2, which eliminates the ganglion cells entirely while leaving
the cholinergic amacrine cell population intact, was shown not
to affect the stratification pattern of the photoreceptors within
the IPL. These results strongly suggest that the targeting of
the photoreceptor terminals to discrete strata within the IPL
is dependent upon the cholinergic amacrine cell processes.
Molecular cloning and characterization of five opsin genes
from the marine flatfish Atlantic halibut (Hippoglossus
hippoglossus)
Authors: HELVIK JON V. , DRIVENES ØYVIND , NÆSS TORE H. , FJOSE ANDERS , SEO HEE-CHAN
Published: October 2003

Most molecular studies on the visual system in fish have been
performed on freshwater teleosts such as goldfish and zebrafish
where cones and rods appear simultaneously. Many marine fishes
have long larval phase in the upper pelagic zone before
transformation into a juvenile and a benthic life style. The
retina at the larval stages consists of only single cone cells;
later during metamorphosis double cones and rods develop. The
flatfish Atlantic halibut (Hippoglossus hippoglossus)
is a typical example of a marine species with such a two-step
retina development. In this study, we have cloned five different
opsins from Atlantic halibut larvae and juvenile retinas. Sequence
comparisons with other opsins and phylogenetic analysis show
that the five genes belong to the opsins of long-wavelength
sensitive (L); middle-wavelength sensitive, MCone
and MRod; and short-wavelength sensitive,
SBlue and SUltraviolet, respectively.
In situ hybridization analysis reveals expression in
double cone (L and MCone), single cone (SBlue
and SUltraviolet), and rod (MRod) types
of photoreceptor cells in juvenile halibut retina. The visual
system in Atlantic halibut seems therefore to have all four
types of cone photoreceptors in addition to rod photoreceptors.
This work shows for the first time molecular isolation of a
complete set of retinal visual pigment genes from a marine teleost
and describes the first cloning of an ultraviolet-sensitive
opsin type from a marine teleost.
Transmission of spatial information in S-cone pathways
Authors: METHA ANDREW B. , LENNIE PETER
Published: October 2003

The mosaics of S-cones and the neurons to which they are connected
are relatively well characterized, so the S-cone system is a
good vehicle for exploring how the sampling of the retinal image
controls visual performance. We used an interferometer to measure
the grating acuity of the S-cone system in the fovea and at
a range of eccentricities out to 20 deg. We also developed a
simple model observer that, by assuming only that cone pathways
are noisy and that signals are subject to eccentricity-dependent
postreceptoral pooling, predicts the measured acuities from
the sampling properties of the S-cone mosaic. The amount of
pooling required to explain performance is consistent with that
suggested by anatomical and physiological measurements.
Topographic map reorganization in cat area 17 after early
monocular retinal lesions
Authors: MATSUURA KAZUKI , ZHANG BIN , MORI TAKAFUMI , SMITH EARL L. , KAAS JON H. , CHINO YUZO
Published: October 2003

Neither discrete peripheral retinal lesions nor the normal
optic disk produces obvious holes in one's percept of the
world because the visual brain appears to perceptually “fill
in” these blind spots. Where in the visual brain or how
this filling in occurs is not well understood. A prevailing
hypothesis states that topographic map of visual cortex reorganizes
after retinal lesions, which “sews up” the hole
in the topographic map representing the deprived area of cortex
(cortical scotoma) and may lead to perceptual filling in. Since
the map reorganization does not typically occur unless
retinotopically matched lesions are made in both eyes, we
investigated the conditions in which monocular retinal lesions
can induce comparable map reorganization. We found that following
monocular retinal lesions, deprived neurons in cat area 17 can
acquire new receptive fields if the lesion occurred relatively
early in life (8 weeks of age) and the lesioned cats experienced
a substantial period of recovery (>3 years). Quantitative
determination of the monocular and binocular response properties
of reactivated units indicated that responses to the lesioned
eye for such neurons were remarkably robust, and that the
receptive-field properties for the two eyes were generally similar.
Moreover, excitatory or inhibitory binocular interactions were
found in the majority of experimental units when the two eyes
were activated together. These results are consistent with the
hypothesis that map reorganization after monocular retinal lesions
require experience-dependent plasticity and may be involved
in the perceptual filling in of blind spots due to retinal lesions
early in life.
Quantification of in vivo anaerobic metabolism in
the normal cat retina through intraretinal pH measurements
Authors: PADNICK-SILVER LISSA , LINSENMEIER ROBERT A.
Published: October 2003

We examined intraretinal [H+] in the intact
retina of anesthetized cats using H+-sensitive
microelectrodes to obtain spatial profiles of extracellular
[H+]. One H+ is produced when
an anaerobically generated ATP is utilized. We theorized that
H+ production directly reflects anaerobic glucose
consumption. From the choroid (pH ∼7.40),
[H+]o steadily increased to
a maximum concentration in the proximal portion of the outer
nuclear layer (pH∼7.20). The shape of the profile was always
concave down, indicating that a net production of H+
occurred across the avascular outer retina. A three-layer diffusion
model of the outer retina was developed and fitted to the data
to quantify photoreceptor H+ extrusion into the
extracellular space (QOR-H+).
It was determined that the outer segment (OS) layer had negligible
H+ extrusion. The data were then refitted to a special
three-layer model in which the OS layer QH+
was set equal to zero, but in which the inner segments and outer
nuclear layer produced H+. The resulting
QOR-H+ was several orders of magnitude
lower than previous measurements of QOR-lactate,
which were based on choroidal mass balances of lactate.
Differential distribution of synaptotagmin immunoreactivity among
synapses in the goldfish, salamander, and mouse retina
Authors: HEIDELBERGER RUTH , WANG MENG M. , SHERRY DAVID M.
Published: October 2003

Synaptotagmin I is the leading candidate for the calcium sensor that
triggers exocytosis at conventional synapses. However, physiological
characterization of the calcium sensor for phasic release at the
ribbon-style synapses of the goldfish Mb1 bipolar cell demonstrates a
lower than predicted affinity for calcium, suggesting that a modified
or different sensor triggers exocytosis at this synapse. We examined
synaptotagmin immunolabeling in goldfish retina using two different
antibodies directed against synaptotagmin epitopes that specifically
labeled the expected 65-kDa protein on western blots of goldfish and
mouse retinal membranes. The first antiserum strongly labeled
conventional synapses in the inner plexiform layer (IPL), but did not
label the ribbon-style synapse-containing synaptic terminals of
goldfish Mb1 bipolar cells or photoreceptors. The second antibody also
specifically labeled the expected 65-kDa protein on western blots but
did not label any synapses in the goldfish retina. A third
synaptotagmin antibody that performed poorly on western blots
selectively labeled goldfish photoreceptor terminals. These results
suggest that synaptotagmin may exist in at least three distinct
“forms” in goldfish retinal synapses. These forms, which
are differentially localized to conventional synapses, bipolar cell,
and photoreceptor terminals, may represent differences in isoform,
posttranslational modifications, epitope availability, and
protein-binding partners. Labeling with these antibodies in the
salamander and mouse retina revealed species-specific differences,
indicating that synaptotagmin epitopes can vary across species as well
as among synapses.
Kinande vowel harmony: domains, grounded conditions and one-sided alignment
Authors: Archangeli Diana , Pulleyblank Douglas
Published: October 2003

The canonical image of vowel harmony is of a particular feature distributed throughout a word, leading to symmetric constraints like AGREE or SPREAD. Examination of the distribution of tongue-root advancement in Kinande demonstrates that harmonic feature distribution is asymmetric. The data argue that a formal (yet asymmetric) constraint (like ALIGN) is exactly half right: such a constraint correctly characterises the left edge of the harmonic domain. By contrast, the right edge is necessarily characterised by phonetically grounded restrictions on feature co-occurrence. Of further interest is the role of morphological domains: the interaction between domain restrictions on specific constraints and unrestricted constraints suggests a formal means of characterising the overwhelming similarity between constraint hierarchies at different morphological levels while at the same time characterising the distinctions between levels.
Broad versus narrow auditory tuning and corresponding bat‐evasive flight behaviour in praying mantids
Authors: Triblehorn Jeffrey D. , Yager David D.
Published: October 2003

Most praying mantids possess a single tympanal ear located in the ventral midline between the metathoracic legs. The auditory system is generally most sensitive to ultrasound in the 25–50 kHz range. Flying males exhibit a short‐latency, stereotyped, multi‐component response to ultrasound that allows them to escape from attacking bats. This study describes a small subset of species that differs in three major respects from the majority of mantis species: (1) their auditory tuning is 1.5–2 times broader; (2) they are sensitive to frequencies above 60 kHz (up to 130 kHz in some species) with thresholds as low or lower than at 25–50 kHz; (3) the behavioural response of the broadly tuned (BT) species includes 10–50 times more flight cessations and can be far less stereotyped, i.e. more ‘evitable’, than that of narrowly tuned (NT) species. However, BT species do not differ from NT species in overall sensitivity. Two species from one subfamily, the Amelinae (family Mantidae), stand out because they are among the least sensitive of any hearing mantids so far tested. Although the two amelines differ from one another in tuning curve shape, they are both more broadly tuned than most mantids. The occurrence of BT species does not follow any obvious phylogenetic pattern; they are patchily distributed among the mantis families, and both BT and NT species can be found in the same subfamily or tribe. We suggest that BT species are responding to a shared ecological pressure. Based on their tuning, the nature of their behavioural response, and their geographic distribution, we hypothesize that high duty cycle (HDC) bats (Rhinolophidae and Hipposideridae) pose a special danger to BT mantids in addition to the threat that all flying mantids face from the more common and widely distributed low duty cycle (LDC) bats.
Chummidae, a new spider family (Arachnida, Araneae) from South Africa
Authors: Jocqué Rudy
Published: October 2003

The paper reports on a new family of spiders from the eastern Cape region in South Africa. Chummidae, new family, are small, three‐clawed spiders, recognized by the abdomen with strong dorsal scutum, provided with a frontal field of stiff macrosetae in large sockets. Further apomorphies are the absence of a fovea, the reduction of posterior and median spinnerets, the absence of major ampullate gland spigots, and the presence of branched lateral tracheae and of a hair‐basket around the cheliceral fang. The type genus Chumma, is represented by two species, both known from male and female – the type species C. inquieta sp. nov. and C. gastroperforata sp. nov. The males of the latter species are remarkable for having two pairs of abdominal pockets, which play a role during mating.
Evolutionary rates and stabilizing selection in large‐bodied opossum skulls (Didelphimorphia: Didelphidae)
Authors: Lemos Bernardo , Marroig Gabriel , Cerqueira Rui
Published: October 2003

Phenotypic evolutionary rates are reported for cranial characters of eight species of large‐bodied Neotropical marsupials: Didelphis aurita, D. marsupialis, D. albiventris, Philander opossum, P. frenata, Lutreolina crassicaudata, Chironectes minimus, and Metachirus nudicaudatus. These rates were found to be lower than expected if cranial diversification in these opossums had occurred by mutation and genetic drift only, and it is clear that a greater diversification was prevented. As all parameters used in estimating rates were very conservative, the conclusion that stabilizing selection has predominated during the evolution of the skull of large‐bodied opossums is fairly robust. We also show that directional selection sustained for 150 generations (158 years) or less is capable of producing differences of the same magnitudes as those found between various pairs of species. Therefore, we conclude that even where a particular differentiation has been caused by directional selection, neutral rate tests are unlikely to infer it. This is because following a morphological shift, stabilizing selection will progressively erase evidences of directional selection.
Female genital dimorphism in a spider (Araneae: Pholcidae)
Authors: Huber Bernhard A. , González Abel Pérez
Published: October 2003

Discontinuous individual variation among members of the same sex, in the same life stage, within a population, is an important phenomenon for our understanding of more fundamental issues in evolutionary biology. One set of morphological characters is conspicuously rare in the literature on intrasexual polymorphisms: genitalia. In this paper we report the first case of female genital polymorphism, the first not only for spiders but apparently for animals in general. We argue that the overwhelming use of genitalia in species identification practiced by many invertebrate taxonomists presents a strong bias against discovering polymorphisms in genitalia. Further methodological and practical aspects of invertebrate taxonomy are discussed that, taken together, make the discovery of genital polymorphisms unlikely, no matter whether or not the phenomenon is rare.
Maternal care and infant behaviour of the bridled nailtail wallaby (Onychogalea fraenata)
Authors: Fisher D. O. , Goldizen A. W.
Published: October 2003

Bridled nailtail wallabies Onychogalea fraenata are endangered, medium‐sized, nocturnal macropodids that persist at only one location in central Queensland, Australia. Characteristics of juvenile development, shelter use, anti‐predator behaviour and maternal care were investigated in the wild using trapping, radio‐tracking and spotlighting observations. Timing of developmental stages was identical to the pattern previously found in captivity, except for age at weaning which was much earlier in the wild. After young had left the pouch permanently at 17 weeks of age and weighing c. 800 g, they always spent the day concealed in dense cover, generally >200 m from their mothers. Juveniles were also alone in >50% of observations at night, and stayed closer to cover than did adult females. Young became independent of their mothers 7–8 weeks after permanent exit from the pouch and weighing c. 1800 g. Females with dependent juveniles changed their behaviour in ways likely to reduce predation on young. They reduced their home ranges, stayed closer to cover and became more wary than other females. Juveniles differed from adult females in their habitat use, anti‐predator behaviour and shelter site preferences. Juveniles were more likely than adults to respond to threats by standing still or lying flat on the ground, whether or not they were in concealing cover. Juveniles used a wider range of smaller shelters than adults, and were less likely to use solid shelters such as hollow logs during the day. Because bridled nailtail wallabies have a ‘hider’ strategy of maternal care and the young rely on crypsis, successful breeding in the wild requires dense vegetation cover.
Habitat use by wood mice (Apodemus sylvaticus) in a changeable arable landscape
Authors: Tattersall Françoise H. , Macdonald David W. , Hart Barbara J. , Manley Will J. , Feber Ruth E.
Published: October 2003

Wood mice Apodemus sylvaticus are potentially useful indicators of change in arable ecosystems. Here we focus on changes resulting from removal of land from arable production under the set‐aside scheme. Wood mice were radio‐tracked to compare: (a) their use of set‐aside, crop and hedgerow before and after harvest; (b) set‐aside configured as margins and as a 3 ha block; (c) cut and uncut 20‐m wide set‐aside margins. Males had larger home ranges, and were more mobile than females. Ranges were larger, and animals more mobile, before harvest than afterwards. There were no differences in range sizes of breeding and non‐breeding animals after harvest, suggesting that changes in habitat use were not a function of cessation of breeding. Before harvest, wood mice used habitats within their ranges at random, and their ranges contained a high proportion of cropped area. After harvest they preferred hedgerow and avoided margin set‐aside within their ranges, but did not similarly avoid the set‐aside block. The proportion of cropped area within their ranges decreased after harvest, and the proportion of margin increased. Our evidence suggests wood mice avoided using the area adjacent to the hedgerow, perhaps to avoid predators. Uncut set‐aside patches were favoured and cut patches avoided, possibly in response to differences in food availability and levels of protection from predators. These results confirm that wood mice are useful indicators of change in arable landscapes.
The relationship between foot size of wild canids and regional snow conditions: evidence for selection against a high footload?
Authors: Muray D. L. , Larivière S.
Published: October 2003

Mammals occupying northern areas may experience reduced fitness through the deleterious effects of snow on locomotion, energy expenditure, and food acquisition. Accordingly, in areas of deep and soft snow, selection may favour mammals possessing disproportionally large feet and lower footload (body mass/foot surface area). We collected carcasses of coyote Canis latrans (n= 472), red fox Vulpes vulpes (n= 199), arctic fox Alopex lagopus (n= 52), grey fox Urocyon cinereoargenteus (n= 17), and wolf Canis lupus (n= 14) and compared body mass, total foot area, difference in surface area between front and hind feet, and footload, among species and populations. All measured morphological attributes differed significantly among canid species; grey fox had the smallest feet, whereas arctic fox had both the lightest mass and lowest footload of all canids. For all species, adult males tended to be heavier and have larger feet than did adult females, and for most species adults were heavier and larger than were juveniles. Foot area in red foxes increased significantly with latitude, with populations found north of 48 °N (i.e. approximate latitude where snow may become limiting) averaging 12% larger feet than those found farther south. For coyotes, body mass increased with latitude, with populations found north of 48 °N averaging 26% heavier mass than those occurring farther south. Coyote foot area also increased with latitude, with populations found north of 48 °N averaging 25% larger feet than those found farther south. When indices of snow severity (mean annual snowfall, mean number of days with snowcover) were considered, foot area for red foxes was correlated with annual snowfall as well as latitude, whereas coyote morphology failed to correlate with any snow‐related variables. These results suggest that snow may have contributed to selection for foot size in some wild canids (i.e. arctic fox, red fox), but such selective forces were probably relatively weak and inconsistent across species.
Evidence for filter‐feeding by the wood‐boring isopod, Sphaeroma terebrans (Crustacea: Peracarida)
Authors: Si Aung , Bellwood O. , Alexander C. G.
Published: October 2003

The morphology of the mouthparts and proventriculus of the wood‐boring isopod Sphaeroma terebrans has been described, with particular reference to its possible filter‐feeding abilities. Scanning electron microscopy revealed that while the mandibles might be designed to scrape pieces of wood from the cavity wall during boring, the rest of the mouthparts are better suited for microphagous feeding. Video observations of the mouthparts demonstrated the ability of S. terebrans to filter out particulate material from the water column, by means of the filtering setae on the first three pairs of pereiopods. The morphology of the gut was found to be largely similar to that of terrestrial herbivorous isopods; primary and secondary filter apparatuses were present, but the masticatory apparatus present in terrestrial herbivores was missing. The morphology of both the gut and mouthparts provides additional support for the assumption that wood is an unlikely food source for S. terebrans.
Evidence for unconditional sperm transfer and sperm‐dependent parthenogenesis in a hermaphroditic flatworm (Girardia tigrina) with fissipary
Authors: Vreys Carla , Crain Jeremy , Hamilton Sherri , Williamson Suzanne , Steffanie Natascha
Published: October 2003

Sperm‐dependent parthenogens are expected to promote higher female fecundity at the expense of the production of excessive numbers of sperm. They are also expected to trade sperm strictly, in order to compensate for the loss of nutrients invested in sperm, that otherwise could be allocated to the female function. In this paper, we present evidence that in a natural population of the freshwater planarian Girardia (= Dugesia) tigrina, sperm‐dependent parthenogenesis is alternated with fissipary, a combination not reported before for freshwater flatworms. More specifically, we found that most individuals that engage in a copulation have no or only few testes and sperm available, despite the presence of a fully developed penis, indicating that male allocation is fairly low in this (dense) population. Female fecundity on the contrary is rather high, with isolated individuals producing up to six fertilized cocoons over a 3‐week period, releasing five young per cocoon on average. An analysis of the mating behaviour further shows that matings in this species are simple and direct with no distinct courtship behaviour. Copulations last for about 36 min and occur at a rate of at least one copulation a day. Bilateral sperm transfer is the rule, but a considerable number of copulations are unidirectional or without sperm transfer. Non‐reciprocal inseminations mainly result from the fact that one or both partners has no sperm stored prior to copulation, indicating that strict sperm trading plays no role in this population of G. tigrina.
Global warming, Bergmann's rule and body mass – are they related? The chukar partridge (Alectoris chukar) case
Authors: Yom‐Tov Yoram , Benjamini Yoav , Kark Salit
Published: October 2003

Using museum specimens collected in Israel during the second half of the 20th century, no support was found for the hypothesis that body mass and tarsus length of chukar partridges Alectoris chukar has changed as a result of global warming. Body mass showed fluctuations during the year, reaching a maximum in late winter and spring and a minimum in summer. Bergmann's rule predicts that in warm‐blooded animals, races from warm regions will be smaller than races from colder regions, and a wider explanation states that body size is positively related to latitude. Because of its topography and varied climate, Israel provides a unique opportunity to separate partly the effect of latitude from that of ambient temperature, thus testing if Bergmann's rule is related to latitude or to climatic variables. We found that body mass (and marginally also tarsus length) declined significantly with decreasing latitude in accordance with the wider explanation of Bergmann's rule, but ambient temperature explained a much smaller fraction of the variation in body mass than latitude. These results weaken the traditional explanation to Bergmann's rule that a heat conservation mechanism causes the latitudinal size variation.
Interspecific differences in male vocalizations of three sympatric fur seals (Arctocephalus spp.)
Authors: Page Brad , Goldsworthy Simon David , Hindell Mark Andrew , Mckenzie Jane
Published: October 2003

This study investigated species recognition based on bark calls and full threat calls (FTCs) in three fur seal species, Antarctic Arctocephalus gazella, subantarctic A. tropicalis and New Zealand A. forsteri, that breed sympatrically and hybridize at subantarctic Macquarie Island. Bark calls, which are produced by males in male–female interactions, were more species‐specific than their full threat calls, suggesting that bark calls could be used in species recognition and female mate choice. Further, the bark calls of A. tropicalis were more species‐specific than those of A. gazella and A. forsteri, suggesting that divergence of calls between species is a consequence of phylogenetic distance, or has resulted from sexual selection through female mate choice. We believe the latter is more probable as we did not observe similar divergence in the FTCs of males. As such, the highly divergent bark calls of A. tropicalis may have resulted from sexual selection that has promoted pre‐mating isolation via the process of reinforcement.
A new record of Limnognathia maerski Kristensen & Funch, 2000 (Micrognathozoa) from the subantarctic Crozet Islands, with redescription of the trophi
Authors: De Smet Willem H.
Published: October 2003

Limnognathia maerski, class Micrognathozoa, so far known only from Arctic Greenland, is reported from the subantarctic Crozet Islands. Fine morphology of the trophi is redescribed using scanning electron microscopy. Results show that the trophi are composed of the same functional units, i.e. incus, paired mallei and epipharynx, as found in Rotifera Monogononta. The zoogeography of the species is briefly discussed.
The effect of initial weight of the ewe on later reproductive effort in domestic sheep (Ovis aries)
Authors: Steinheim Geir , Mysterud Atle , Holand Øystein , Bakken Morten , Ådnøy Tormod
Published: October 2003

In ungulates, females typically need to reach a critical threshold body weight in order to reproduce. Females born in ‘poor’ years may lose 1 year of reproduction, as they reach the critical body mass 1 year later. Some studies report also a lasting effect of low initial body weight into prime age, while several other studies have shown that nearly all prime‐age females ovulate or are pregnant. However, the quality of the offspring (as measured by offspring body weight) is often not considered. We tested whether female ungulates with an initially low body weight (at around weaning) reach the same reproductive output as females with higher initial weights, and thus whether or not they are able to compensate for their initial low weight. Data on body weight of 123 533 lambs of domestic sheep Ovis aries from 73 299 litters that in turn derived from 32 359 different ewes were used. All ewes and lambs had been free‐ranging on outlying pastures in Norway during the entire summer season. Ewes with an initially low body weight produced smaller offspring throughout their lifespan. Ewes with an initially low body weight also produced fewer lambs at first and second parturition, but lifetime number of offspring was not related to ewes' initial weight. We concluded that bigger was better: the smaller offspring of ewes with a low initial weight demonstrate a lasting cost on reproductive effort, with consequences for animal production systems and management of wild ungulates.
Immunocytochemical analysis of the process of keratinization of the epidermis of snakes
Authors: Alibardi L.
Published: October 2003

The epidermis of snakes produces two types of keratinocytes containing an alpha (soft) and a beta (hard) form of keratin. During epidermal renewal, which allows body growth, six types of epidermal layers are produced before moulting: oberhautchen, beta‐, mesos, alpha‐, lacunar, and clear. The precise layers in which beta‐keratin, alpha‐keratin and matrix proteins (loricrin and filaggrin) are produced, have been studied by light and ultrastructural immunocytochemistry. An antibody against chick scale beta‐keratin recognizes also snake beta‐keratin only in the oberhautchen and beta‐layer. This confirms the phylogenetic relationships between avian and reptilian hard (beta) keratins. Beta‐keratin rapidly disappears in mesos‐cells, where little beta‐keratin is present. Antibodies that recognize alpha‐keratins (AE1, AE2, AE3) show that acidic keratins (AE1 positive) mainly localize in the most basal layers and basic keratins (AE3 positive) in all layers but disappear in those layers that are keratinized, especially in the beta‐layer. The AE2 immunolabelling (a marker of keratinization in mammalian epidermis) is localized in the compact alpha‐layer. This pattern is similar to that for loricrin and filaggrin, although in the latter the reaction is less intense and located mainly in the hinge regions among scales. Alpha‐keratins and associated proteins disappear in the oberhautchen and beta‐cells where beta‐keratin is produced instead. This study suggests that the shedding mechanism in snakes evolved after the hard beta‐keratin was compartmentalized beneath the soft alpha‐keratin to create an intra‐epidermal weakness region. The study also suggests that some common mechanism of alpha‐keratinization is present in snakes, and the other amniotes in general.
The prey of domestic cats (Felis catus) in two suburbs of Auckland City, New Zealand
Authors: Gillies Craig , Clout Mick
Published: October 2003

The prey brought in by 80 cats Felis catus over 1 year was monitored in two suburbs of Auckland, New Zealand: one suburb was completely urban, the other on the urban/forest fringe. Cat owners were asked to record and, if possible, keep the prey that their cats brought in. Rodents were the main prey brought in by domestic cats in the urban/forest fringe habitat, whereas invertebrates were the main prey in the fully urban habitat. Birds were caught in similar numbers by cats in both areas and were the second most important prey group at both study sites. However, more native birds were caught by cats in the urban/forest fringe area than in the fully urban habitat. Lizards were caught in similar numbers and were the third most important prey group in both study areas.
Courtship and mating of the tailed frog (Ascaphus truei)
Authors: Stephenson Barry , Verrell Paul
Published: October 2003

Frogs (Amphibia: Anura) have contributed greatly to our understanding of the functions and evolution of sexual behaviour patterns, but few studies have been conducted on ‘primitive’ taxa. Here we describe laboratory observations that characterize aspects of the courtship and mating of the tailed frogAscaphus truei, one of the most basal of living frogs. Fertilization is internal (a rare and probably apomorphic state for anurans) and sperm transfer is via an erectile intrommitent organ, or ‘tail.’ This structure seems to be an autapomorphy. Inguinal amplexus accomplishes mating (probably a plesiomorphic state), but the combination of amplexus and copulation, previously termed copulexus, is unique (autapomorphic). Mate location is not mediated acoustically (sexual vocalizations probably are apomorphic), but may involve visual or chemical cues. In a competitive context, heavier males do not seem to enjoy an advantage in being the first to initiate mating, and rivals rarely displace males already engaged in copulexus by wrestling. The courtship and mating of the tailed frog consists of a mosaic of traits that are ancestral, derived and unique within the clade Anura. Efficient location and then (with internal fertilization) stimulation of females during copulexus may influence male reproductive success more than wrestling.
The biology and functional morphology of Dianadema gen. nov. multangularis (Tate, 1887) (Bivalvia: Anomalodesmata: Clavagellidae)
Authors: Morton Brian
Published: October 2003

The anomalodesmatan Clavagellidae can be separated from the Penicillidae on the basis of ligament and adventitious tube or crypt structure. The Clavagellidae includes species of Clavagella (and Dacosta), Bryopa and Stirpulina. Two species, first described as Clavagella torresi Smith, 1885 and Aspergillum multangularis Tate, 1887, have consistently been placed in the genus Clavagella, but both are herein located in the new genus Dianadema. Because more material is available, this is primarily a study of Dianadema multangularis (Tate) which is designated as the type species of the new genus. Dianadema multangularis is unlike Clavagella, Bryopa and Stirpulina which are, respectively, recessing, boring and endobenthic representatives of the Clavagellidae, in that it is cemented and possesses a crown of dorsal tubules, in addition to anterior and ventral ones. As in all clavagellids (sensu stricto) the left valve is cemented into the fabric of an adventitious crypt while the right valve is free inside it. There is also a posterior multi‐angular siphonal tube. The anatomy of D. multangularis is described and it is, in most respects, a typical clavagellid. The species differs from other clavagellids in the inferred aeration of the crypt via patterns of water flow, the crown of crypt tubules, and its unique cemented lifestyle. There are three (known) genera of clavagelloids endemic to southern and eastern Australia, i.e. Dacosta and, now, Dianadema (Clavagellidae) and to which the third, Humphreyia (Penicillidae), is similar in that the latter two are both cemented, albeit convergently. They also provide a surprising picture of convergent evolution of the cemented lifestyle even to the extent that both possess a unique pair of pericardial proprioreceptors, each derived differently, to monitor body tonus. Moreover, two other anomalodesmatan genera are also cemented, i.e. Cleidothaerus (Cleidothaeridae) and Myochama (Myochamidae), and these too are restricted to eastern Australia (and New Zealand). What forces promoted cementation in these four antipodean anomalodesmatan families are unknown.