bluuebunny/crossref_metadata_2025 huggingface dataset:
Complex bounds for renormalization of critical circle maps
Authors: YAMPOLSKY MICHAEL
Published: July 2002

We use the methods developed with Lyubich for proving complex bounds for real quadratics to extend de Faria's complex a priori bounds to all critical circle maps with an irrational rotation number. The contracting property for renormalizations of critical circle maps follows.

As another application of our methods we present a new proof of a theorem of Petersen on local connectivity of some Siegel Julia sets.
Sur un critère de récurrence en dimension 2 pour les marches stationnaires, applications
Authors: CONZE J.-P.
Published: July 2002

Let $(E,{\cal A},\mu,T)$ be a dynamical system and let $\Phi$ be a function defined on $E$ with values in $\mathbb{R}^2$. We give a criterion, the central limit theorem along subsequences of positive density, for the recurrence of the corresponding ‘stationary walk’ defined as the cocycle $\big(\sum^{n-1}_{j=0}\Phi(T^jx)\big)_{n\geq1}$.

This criterion is satisfied by functions which are homologous to a martingale difference (a property which holds for regular functions in many systems). It can also be applied to the periodic Lorentz gas in the plane and shows recurrence for this model.
Religion and old age
Authors: DAVIE GRACE , VINCENT JOHN
Published: July 2002

The interconnections between religion and old age are complex;
the
more so given that the concept of age itself has – for a large part
of
human history – been determined by religious understandings of life.

In traditional societies, religion played a crucial part in structuring
the
transitions between one stage of the life and the next and in defining

maturity and fulfilment. And up to a point it still does: in Western
societies at the turn of the millennium the association of religious rituals

with key moments in the life course – birth, adolescence, marriage
and
above all death – remains widespread. Such interconnections change

over time, however; they also vary from place to place.
Going down like a song: national identity, global commerce and the Great Canadian Party
Authors: Duffett Mark
Published: July 2002

On 1 July 1992 over 100,000 people assembled in various locations across Canada to see their favourite bands play live at the Great Canadian Party. Broadcast on television and radio, this Canada Day spectacle celebrated the country's 125th birthday, but rather than being organised by the state or a non-profit making citizen's movement, it was facilitated by more than $100,000 of corporate sponsorship. Drawing on fieldwork in Vancouver, I will argue that external funding initially helped Canadian musicians but soon allowed outside sponsors to control the live music industry. These sponsors could then co-opt anxieties about national unity in a selective celebration designed purely for their own ends. By addressing the Great Canadian Party's emergence and historic moment the following discussion will explore what it meant for Canada to be represented through a giant commercial, a commercial drawing on shared national identity in order to sell the products of a global industry. The Party revealed how judiciously agents of commerce could use popular culture to negotiate between geographic scales. Despite that success, however, the resistance of participating bands suggests that the Party could not secure full hegemony for its sponsor's project.
An automated digging control for a wheel loader
Authors: Lever Paul J. A.
Published: July 2002

An Automated Digging Control System (ADCS) for a wheel loader is developed that utilizes a behavior-based control structure combined with fuzzy logic. This controller exhibits the real-time reactive responses necessary for executing digging tasks in an uncertain, unstructured and dynamic excavation environment. This paper presents field test results of a prototype ADCS that was developed and implemented on a Caterpillar 980G wheel loader. Test results show that the performance of the automated system is comparable to that of an expert human operator in a wide range of excavation situations.
Music technology inspected: good teaching in Key Stage 3
Authors: Mills Janet , Murray Andy
Published: July 2002

How is information and communications technology (ICT) used to promote musical learning by pupils aged eleven to fourteen, i.e. pupils in Key Stage 3? Inspectors from the Office for Standards in Education (OFSTED) visited 52 schools in England, and inspected 161 Key Stage 3 music lessons that made some use of ICT. This article describes the characteristics of the good teaching found in 106 of those lessons, and discusses some issues concerning the use of ICT in classrooms.
STRUCTURAL CHANGE IN AR(1) MODELS
Authors: Chong Terence Tai-Leung
Published: July 2002

This paper investigates the consistency of the least squares
estimators and derives their limiting distributions in an AR(1)
model with a single structural break of unknown timing. Let
β1 and β2 be the preshift and
postshift AR parameter, respectively. Three cases are considered:
(i) |β1| < 1 and
|β2| < 1; (ii)
|β1| < 1 and β2 = 1;
and (iii) β1 = 1 and |β2|
< 1. Cases (ii) and (iii) are of particular interest but are rarely
discussed in the literature. Surprising results are that, in both cases, regardless of the location of the change-point estimate, the unit root
can always be consistently estimated and the residual sum of squares
divided by the sample size converges to a discontinuous function
of the change point. In case (iii), [circumflex over beta]2
does not converge to β2 whenever the change-point estimate
is lower than the true change point. Further, the limiting distribution
of the break-point estimator for shrinking break is asymmetric for case
(ii), whereas those for cases (i) and (iii) are symmetric. The appropriate
shrinking rate is found to be different in all cases.
VALID CONFIDENCE INTERVALS IN REGRESSION AFTER VARIABLE SELECTION
Authors: Kabaila Paul
Published: July 2002

We consider a linear regression model with regression parameters
(θ1,...,θp) and error variance
parameter σ2. Our aim is to find a confidence interval with
minimum coverage probability 1 − α for a parameter of interest
θ1 in the presence of nuisance parameters
(θ2,...,θp,σ2).
We consider two confidence intervals, the first of which is the standard
confidence interval for θ1 with coverage probability 1
− α. The second confidence interval for θ1 is
obtained after a variable selection procedure has been applied to
θp. This interval is chosen to be as short as
possible subject to the constraint that it has minimum coverage probability
1 − α. The confidence intervals are compared using a risk function
that is defined as a scaled version of the expected length of the confidence
interval. We show that, subject to certain conditions including that
[(dimension of response vector) − p] is small,
the second confidence interval is preferable to the first when we
anticipate (without being certain) that
|θp|/σ is small. This comparison
of confidence intervals is shown to be mathematically equivalent to a
corresponding comparison of prediction intervals.
ASYMPTOTIC INFERENCE FOR NEARLY UNSTABLE AR(p) PROCESSES
Authors: van der Meer Tjacco , Pap Gyula , van Zuijlen Martien C.A.
Published: July 2002

In this paper nearly unstable AR(p) processes
(in other words, models with characteristic roots near the
unit circle) are studied. Our main aim is to describe the
asymptotic behavior of the least-squares estimators of the
coefficients. A convergence result is presented for the
general complex-valued case. The limit distribution is given
by the help of some continuous time AR processes. We apply
the results for real-valued nearly unstable AR(p)
models. In this case the limit distribution can be identified
with the maximum likelihood estimator of the coefficients of
the corresponding continuous time AR processes.
Gap-building-phase regeneration in a tropical montane cloud forest of north-eastern Mexico
Authors: Arriaga Laura
Published: July 2002

Regeneration processes associated with gap-building-phase sites are described for the tropical montane cloud forest of the El Cielo Biosphere Reserve in Tamaulipas, Mexico. Twelve gap-building-phase sites c. 20 y old were selected within the forest according to their gap size and severity of disturbance (i.e. number of fallen logs). All flowering plants were recorded within the sites and specimens were identified to species level. Species were related to genera geographical affinity and growth form. Abundance, individual height and aerial crown cover were also recorded for all species. The composition for these sites was 121 vascular plant species grouped in 96 genera and 60 families. Results suggest that the advanced regeneration of shrub and tree species of the medium canopy, such as Eugenia capuli, Ternstroemia sylvatica, Turpinia occidentalis, Meliosma oaxacana, Myrsine coriacea and Podocarpus reichei, was favoured by the disturbance regime prevailing in this forest community. All of these woody species belong to tropical genera and are structurally dominant in the gap-building-phase sites. A differential response of the vegetation was obtained in these sites as a function of the severity of disturbance and gap size. This response was revealed by the dominance-diversity relationships. Small gaps (45–95 m2) or gaps created by two treefalls showed a higher diversity and density compared to larger gaps (95–150 m2) or those created by four fallen logs, which had a lower species diversity and significantly lower tree and vine densities. These results imply that gap size and the severity of disturbance have a significant effect on the regeneration of these disturbed sites.
Demography of a savanna palm tree in Ivory Coast (Lamto): population persistence and life-history
Authors: Barot Sébastien , Gignoux Jacques , Vuattoux Roger , Legendre Stéphane
Published: July 2002

Borassus aethiopum is a dioecious palm tree of African savannas. A stage-classified matrix population model has been parametrized with field data (Lamto reserve, Ivory Coast). It enabled the study of the persistence of the population, and analysis of its sensitivity to different vital rates. Age of palms in each stage were estimated to complete the description of the palm life-history. The main results are: (1) The studied populations are very close to the equilibrium but the stable stage distribution (predicted by the model) and the observed distribution are significantly different indicating a former change in the vital rates. (2) Reproduction seems to be highly delayed (first reproduction on average at 114 y), while the estimated duration of the reproductive part of the life-cycle is relatively short (22 y).
Pollination in a degraded tropical landscape: a Hong Kong case study
Authors: CORLETT RICHARD T.
Published: July 2002

Although the pollination biology of many individual plant species has been investigated in the Oriental region, there
have been very few community-level studies. The two most comprehensive of these were in the primary mixed
dipterocarp forest of Lambir Hills National Park, Sarawak (4°20′N: Momose et al. 1998, Sakai et al. 1999) and in the
warm temperate evergreen broad-leaved forest and cool temperate mixed forest on Yakushima Island (30°N: Yumoto
1987, 1988). Hong Kong (22°17′N) lies midway between these sites, at the northern margin of the tropics, where
winter temperatures fall below 10 °C at sea-level for a few days every year and there are occasional frosts above 400
m (Dudgeon & Corlett 1994). Latitudinal effects, however, are compounded in comparisons with other well-studied
East Asian sites, by centuries of massive human impact, leaving a degraded landscape of steep, eroded hillsides,
covered in fire-maintained grassland, secondary shrublands and, locally, secondary forests (Zhuang & Corlett 1997).
This history has left a relatively impoverished fauna but a surprisingly diverse flora, including 400 native tree species
(Corlett & Turner 1997). In these circumstances, failures of pollination and dispersal mutualisms might be expected
to accelerate the loss of plant species from the landscape (Bond 1994, Kearns & Inouye 1997). Previous studies have
shown that most woody vegetation in Hong Kong is dominated by species whose seeds can be dispersed by the
commonest avian frugivores, the light-vented and red-whiskered bulbuls (Pycnonotus sinensis (Gmelin) and P. jocosus
(Linn.)) and the Japanese white-eye (Zosterops japonicus Swinhoe) (Corlett 1996, 1998), but there is no equivalent
information available on pollination biology.
Tree-liana relationships in a tropical evergreen forest at Varagalaiar, Anamalais, Western Ghats, India
Authors: MUTHURAMKUMAR S. , PARTHASARATHY N.
Published: July 2002

In a 30-ha permanent plot of tropical evergreen forest at Varagalaiar, Indian Western Ghats, all trees ≥
30 cm girth at breast height (gbh) were examined for the presence of lianas ≥ 1 cm dbh. The plot contained 13 445
trees in 152 species and 11 200 lianas in 75 species. Twenty-eight per cent of trees supported lianas and the mean
number of lianas per tree was 0.38 ± 0.72. Association analysis between lianas and trees of 16 tree families and 20
abundant tree species indicated that tree susceptibility to lianas was better pronounced at species rather than at family
level. Overall, at Varagalaiar site, the aggregation of lianas followed neither Poisson nor clumped distribution. Among
the four dominant tree families Dipterocarpaceae and Clusiaceae fit to the negative binomial model better than Euphorbiaceae and Meliaceae. These four families differed in their susceptibility level with 34.6% , 36.7% , 24.1% and 27.7%
of trees ≥ 30 cm gbh respectively supporting lianas. At the species level, the proportion of trees with lianas was
positively correlated with the mean branch free bole height of trees ≥ 30-40 and ≥ 40 cm gbh classes, and the mean
number of lianas per tree was also positively correlated with the mean branch bole height of trees ≥ 30 cm gbh. Of
the 16 abundant families, Euphorbiaceae contributed 31% and dominated the lower canopy, but its susceptibility to
lianas was lower when compared to most other families.
Tree seedling performance in canopy gaps in a tropical rain forest at Nouragues, French Guiana
Authors: VAN DER MEER PETER J. , STERCK FRANK J. , BONGERS FRANS
Published: July 2002

The effect of natural canopy gaps on the performance of naturally occurring tree seedling populations was studied in a tropical rain forest in French Guiana. This was done at two levels of scale. Firstly, on a 20 m × 250 m forest transect intersecting four canopy gaps, it was investigated how patterns of recruitment, growth and survival of seedlings of Cecropia obtusa, Dicorynia guianensis and Pourouma bicolor differed between canopy gaps and closed forest. Secondly, for one large natural canopy gap, performance of seedling cohorts established before (‘pre-gap’ cohorts) and after (‘post-gap’ cohorts) gap formation was studied in relation to environmental heterogeneity. The direct site factor (DSF) was used as an indicator of light availability in the gap zone. Cecropia specialised in large gaps, and also in specific sites within the large gap: seedling performance was increased by light, and by dead wood. Pourouma mainly germinated under closed forest conditions, where it can survive for a long period until a canopy gap is formed nearby. Pourouma seedlings adjusted well to the new gap environment but they did not specialise in specific places within the gap. Seedling location of Pourouma seedlings was mainly determined by accidental positioning before gap formation. Dicorynia was able to germinate both in gaps and under closed forest conditions. Although the number of gaps studied in this study was low, the results show that seedling establishment, early growth and survival of the three tree species were affected by canopy gaps and by the environmental heterogeneity within a large gap.
Interspecific synchrony and asynchrony in the fruiting phenologies of congeneric bird-dispersed plants in Panama
Authors: Poulin Brigitte , Wright S. Joseph , Lefebvre Gaëtan , Calderón Osvaldo
Published: July 2002

Plants potentially compete for seed dispersal. Selection may favour temporally segregated fruiting phenologies to minimize this competition and also to maintain resident populations of dispersal agents. Alternatively, selection may favour temporally aggregated fruiting phenologies when the effectiveness of seed dispersal agents varies seasonally or when large, synchronous fruit displays enhance dispersal. These evolutionary scenarios assume that plants share seed dispersal agents. This assumption and temporal overlap in fruiting phenologies were evaluated for the Miconia and Psychotria of central Panama. These two genera accounted for 18 and 27%, respectively, of 1096 fleshy fruits found in regurgitation or faecal samples taken from 2054 birds of 103 species netted in the forest understorey. Two species of manakins accounted for 62% (123/200) of all Miconia fruit taken. Three species of manakins and three species of migratory thrushes accounted for 97% (282/292) of all Psychotria fruits taken. There is a high potential for intrageneric competition for seed dispersal for both plant genera. Null model analyses showed that the fruiting phenologies of Miconia (14 species) are segregated in time, while fruiting of Psychotria (21 species) is highly aggregated. The Miconia were found in up to 24% of the diet samples for the two manakin species, suggesting that Miconia may be a critical resource for both species. The Psychotria fruited when the diversity of understorey fruits was greatest, suggesting a high potential for both intra- and extrageneric competition. The abundance and nomadism of the six bird species that consumed most Psychotria fruit peaked when the Psychotria fruited, supporting the enhancement hypothesis.
Reflections on the classification of
causes of death
Authors: ALTER GEORGE C. , CARMICHAEL ANN G.
Published: July 2002

On November 11–14 1993, Indiana University hosted a conference on the ‘History of Registration of Causes of Death’, with funding from the US National Institute on Aging and the National Institute of Child Health and Human Development. The conference brought together historians of medicine and historically-oriented demographers and epidemiologists to discuss the origins of the recording of
causes of death and the possible uses of these documents in demographic and epidemiological research. Demographers and epidemiologists would like to use long-run series of causes of death to examine the effects of social and economic conditions, the availability of health care, and specific risk factors on mortality. Many important questions (such as the effects of early health experiences on old-age morbidity and mortality) are best studied with data on changes over long periods of time. However, it is very difficult to construct a consistent series of deaths by cause over time because advances in medical theory and practice have led to significant changes in the classification of diseases. For example, it is unclear whether the prevalence of heart disease was increasing, decreasing, or constant before 1940, because heart disease was often classified under other categories.

The essays in this special number of
Continuity and Change offer a range of insights on the historical circumstances in which cause-of-death registration emerged. They help us to see the ways in which medical theory, medical practitioners, and their increasingly influential professional organizations shaped the conceptualization of reporting of causes of death. Günter Risse's
‘Causes of death as a historical problem’ serves as an overview of the problems that social historians of medicine find underlying any continuous history of mortality experience. Above all, he argues, medical historians react as historians, wary
of Whiggish confidence in state records without attention to the ideologies governing their creation.
Combining local and global search in a constraint programming environment
Authors: CASEAU YVES , LABURTHE FRANÇOIS , LE PAPE CLAUDE , ROTTEMBOURG BENOÎT
Published: July 2002

This paper presents several case studies which illustrate how constraint programming can benefit from the combination of global and local search techniques, offering a flexible and efficient platform for the design of combinatorial optimisation applications. For job-shop scheduling, we relate experiments with local search procedures that use
global search to intensively explore a given neighbourhood, in the spirit of “shuffle” methods. For preemptive job-shop scheduling, two basic search strategies, Depth-First Search and Limited Discrepancy Search, are compared. For Vehicle Routing we report an Incremental Local Optimisation heuristic, combined with Limited Discrepancy Search. Finally, we show how ad hoc algebras can considerably enhance the design of heuristics based on local and global search within a constraint-programming environment. Experiments on vehicle routing will enlighten how such a language for “search and insert” control can enable automated tuning and discovery of new strategies adapted to the instances typology of the problem at stake.
OPTIMAL MAINTENANCE DECISIONS FOR DIKES
Authors: Speijker Lennaert J. P. , van Noortwijk Jan M. , Kok Matthijs , Cooke Roger M.
Published: July 2002

To protect the Dutch polders against flooding, more than
2500 km of dikes have been constructed. Due to settlement,
subsoil consolidation, and relative sea-level rise, these
dikes slowly sink “away into the sea” and should
therefore be heightened regularly (at present, every 50
years). In this respect, one is interested in safe and
cost-optimal dike heightenings for which the sum of the
initial cost of investment and the future (discounted)
cost of maintenance is minimal.

For optimization purposes, a maintenance model has been
developed for dikes subject to uncertain crest-level decline.
On the basis of engineering knowledge, crest-level decline
has been modeled as a monotone stochastic process with
expected decline being either linear or nonlinear (i.e.,
linear after transformation) in time. For both models and
for a particular unit time, the increments are distributed
according to mixtures of exponentials.

In a case study, the maintenance decision model has been
applied to the problem of heightening the Dutch
“Oostmolendijk.”
SECOND LANGUAGE ACQUISITION AND THE CRITICAL PERIOD
HYPOTHESIS. David Birdsong (Ed.). Mahwah, NJ: Erlbaum, 1999. Pp. x +
191. $45.00 cloth.
Authors: Young-Scholten Martha
Published: July 2002

Neuro-neophytes need not be deterred by “ . . . in the somatosensory cortex of rats,
the critical period for the reorganization of the barrel cells in response to haptic stimulation from
the vibrissae is essentially coterminous with the period when LTP can be induced in those
cells” (p. 70). The content of this volume more than compensates for any difficult
passages, raising enough issues to generate discussion as well as fuel further research by those
who know their ERPs from their ECPs.
The syntagmatic–paradigmatic shift and reading development
Authors: CRONIN VIRGINIA S.
Published: July 2002

This study examined developmental change in the word association task as reading acquisition occurred. Syntagmatic responses follow the stimulus word in discourse, ‘cold’ – ‘outside’, while paradigmatic associates are of the same form class, ‘cold’ – ‘hot’. Some 59 children were tested three times during the school year. The average age of the younger group was 5;4, and the older group, 6;2 at the October test. They were given the PPVT, the Woodcock Reading Mastery Test, and a word association task. The younger group gave an increasing number of rhyming responses and the older group gave more paradigmatic responses as the year progressed. Regression analyses with the older group attributed this to reading acquisition. The changing nature of the cognitive representation of words as reading acquisition took place was discussed.
The Hausdorff dimension of Julia sets of entire functions III
Authors: STALLARD GWYNETH M.
Published: July 2002

It is known that, for a transcendental entire function f,
the Hausdorff dimension of the Julia set of f satisfies
1[les ]dim J(f)[les ]2.
In this paper we introduce a family of
transcendental entire functions fp, K
for which the set {dim J(fp,
K)[ratio ]0<p, K<∞}
has infemum 1 and supremum 2.
Recurrent surface homeomorphisms
Authors: KOLEV B. , PÉROUÈME M.-C.
Published: July 2002

An orientation-preserving, recurrent homeomorphism of the two-sphere
which is
not the identity is shown to admit exactly two fixed points. A recurrent

homeomorphism of a compact surface with negative Euler characteristic is
periodic.
Direct Determination of Angular Velocity Using GPS
Authors: Ueno Mami , Santerre Rock , Kleusberg Alfred
Published: July 2002

Controlling a ship in a berthing operation is carried out mainly by the change of state, such
as velocity and yaw rate (turn rate), although the value of the change of state is very small
at berthing. Very high precision is, therefore, required to determine the velocity and angular
velocity. A sensor that has an accuracy of ±0.02°/s (1 σ) is sought for determination of turn
rate in a berthing system. Three-dimensional angular velocity can directly be determined,
with 2 independent baselines of 3 GPS antennas, using instantaneous Doppler measurements
or phase rate (temporal difference of phase) observations. This paper discusses the
mathematical model for direct determination of angular velocity using GPS, and the
comparison of the results of the angular velocity determination using the Doppler and phase
rate. The precision of angular velocity determination is estimated using temporal difference
of the attitude sensors (TSS and gyrocompass) on board a hydrographic sounding ship. The
RMS values of the difference of yaw rate determination between the two systems were:
±0.16°/s using phase rate and ±0.31°/s using Doppler measurements with the separation
of onboard antennas of ca. 1·34 m. 10 m baselines could satisfy the sensor requirements for
angular velocity determination during berthing maneuvers.
Effects of oil and other surface-active organic pollutants on aquatic birds
Authors: STEPHENSON RICHARD
Published: July 2002

A variety of organic contaminants can potentially have impact on aquatic birds by their affecting surface tension. Avian plumage constitutes a porous barrier to water and the air trapped between the feathers serves as thermal insulation. When the air is displaced, the birds expend extra energy to maintain a normal body temperature, but this response cannot be sustained for long, especially at low environmental temperatures. When energy stores are depleted, hypothermia and death ensue. Surface tension is the force that resists infiltration of water into the plumage. The critical surface tension for feather wetting is conservatively estimated to be in the range 38–50 mN m-1. The hypothesis that surface-active organic contaminants can have significant detrimental effects on aquatic birds was evaluated. New data obtained in a study of water penetration pressures in Lesser Scaup contour feathers show that the 'wettability safety factor' is reduced by about half during moult. That is, the critical surface tension was raised to approximately 49–58 mN m-1 in moulting Lesser Scaup. The energetic and behavioural effects of oil contamination are reviewed, and it is concluded that even small quantities of organic material may confer significant physiological cost. The available data generally support the hypothesis that waterfowl face a potential risk associated with chronic or periodic mild depression of water surface tension due to organic pollutants, including oils and detergents. However, much of the evidence is indirect and further research, especially long-term assessment of surface tension in marine, estuarine and freshwater habitats, is needed to determine whether a real environmental problem exists.
Active infection with Helicobacter pylori in healthy couples
Authors: BRENNER H. , ROTHENBACHER D. , BODE G. , DIEUDONNÉ P. , ADLER G.
Published: July 2002

The mode of spread of Helicobacter pylori infection is
subject to ongoing debate. Recent
studies among patients with gastrointestinal disorders suggest a potential
role of conjugal
transmission. In this study, the clustering of H. pylori infection
was assessed among 110
employees of a health insurance company and their partners. Active infection
with H. pylori
was measured by the 13C-urea breath test. Information on potential
confounders was collected
by a standardized questionnaire. Overall, 16 employees (14·5%) and
24 partners (21·8%) were
infected. While only 7% (6/86) of employees with an uninfected partner
were infected, this
applied to 42% (10/24) of employees with an infected partner. A very
strong relation between
partners' infection status persisted after control for age and other
potential confounders
(adjusted odds ratio, 7·0; 95% confidence interval, 1·8–26·7).
Furthermore, the risk of infection
increased with the number of years lived with an infected partner. These
results support the
hypothesis of a major role of spouse-to-spouse transmission of H. pylori
infection.
The occurrence of Trypanosoma evansi in buffaloes in
Indonesia, estimated using various diagnostic tests
Authors: DAVISON H. C. , THRUSFIELD M. V. , HUSEIN A. , MUHARSINI S. , PARTOUTOMO S. , RAE P. , LUCKINS A. G.
Published: July 2002

The prevalence and incidence of Trypanosoma evansi infections in village buffaloes in Central
Java were estimated using parasitological tests, two antigen-detection ELISAs (2G6 Ag-ELISA
and Tr7 Ag-ELISA), an antibody-detection ELISA (IgG ELISA) and a card agglutination test
(CATT). Of 2387 village buffaloes tested in five districts, 4% (95% confidence interval [CI]:
3%, 5%) were positive with the microhaematocrit test (MHCT), 58% (95% CI: 56%, 60%)
were positive with the 2G6 Ag-ELISA and 70% (95% CI: 68%, 72%) were positive with the
Tr7 Ag-ELISA. An increasing prevalence with age was found and the proportion of positive
buffaloes was highest in the over 84 months-old age-group (68%) with the 2G6 Ag-ELISA and
in the 37–60 months-old age-group (78%) with the Tr7 Ag-ELISA. Parasitaemic buffaloes were
found in more than half of the villages visited. Corrected village-specific prevalence values
obtained with the two Ag-ELISAs ranged from 0% to over 100%, and prevalence differed
significantly (P[les ]0·0001) between villages in four of the five districts. Overall, 10% of
buffaloes tested in markets were found to be parasitaemic and 39, 56 and 47% were found
positive with the 2G6 Ag-ELISA, IgG ELISA and CATT, respectively. Incidence rates varied
according to the test used and ranged from 0·22 (95% CI: 0·09, 0·44)
to 0·44 (95% CI: 0·24, 0·76), per animal-year at risk,
in two villages. The results highlight the importance of using
validated diagnostic tests to obtain accurate estimates of prevalence and incidence. These
parameters are needed, for example in mathematical models, for the development and
evaluation of different control strategies for T. evansi infections in buffaloes.
Characterization of multi-drug resistant Salmonella typhi
isolated from Pakistan
Authors: SHANAHAN P. M. A. , KARAMAT K. A. , THOMSON C. J. , AMYES S. G. B.
Published: July 2002

Thirty-nine strains of Salmonella typhi, isolated in 1995 from four Districts in Pakistan,
Rawalpindi, Islamabad, Kharian and Jehlem, were catalogued and examined. Chromosomal
DNA from each isolate was digested with XbaI restriction endonuclease and subjected to
pulsed-field gel electrophoresis. Three clonal variants comprising of 17–19 DNA fragments
were identified. Antibiotic susceptibility testing identified that 37 of the S. typhi were resistant
to chloramphenicol, trimethoprim and ampicillin. These antibiotic resistance genes were found
to be located on one of four plasmids belonging to incompatibility group IncHI1 and ranging
in size from 150–175 Kb. The genes responsible for this resistance in each case were the
chloramphenicol acetyltransferase (CAT) type I, the dihydrofolate reductase (DHFR) type VII
and the β-lactamase TEM-1 respectively.
A community-wide outbreak of Salmonella enterica serotype
Typhimurium infection associated with eating a raw milk soft
cheese in France
Authors: DE VALK H. , DELAROCQUE-ASTAGNEAU E. , COLOMB G. , PLE S. , GODARD E. , VAILLANT V. , HAEGHEBAERT S. , BOUVET PH. , GRIMONT F. , GRIMONT P. , DESENCLOS J.-C.
Published: July 2002

In 1997, a community-wide outbreak of Salmonella enterica serotype Typhimurium
(S. typhimurium) infection occurred in France. The investigation included case searching and a
case-control study. A case was defined as a resident of the Jura district with fever or diarrhoea
between 12 May and 8 July 1997, from whom S. typhimurium was isolated in stool or blood.
One hundred and thirteen cases were identified. Thirty-three (83%) of 40 cases but only 23
(55%) of 42 community controls, matched for age and area of residence, reported eating
Morbier cheese (Odds ratio: 6·5; 95% Confidence Interval: 1·4–28·8). Morbier cheese samples
taken from the refrigerators of two case-patients and one symptom-free neighbour cultured
positive for S. typhimurium of the same phage type as the human isolates. The analysis of
distribution channels incriminated one batch from a single processing plant. These findings
show that an unpasteurized soft cheese is an effective vehicle of S. typhimurium transmission.
A one year study of Escherichia coli O157 in raw beef and lamb products
Authors: CHAPMAN P. A. , SIDDONS C. A. , CERDAN MALO A. T. , HARKIN M. A.
Published: July 2002

Between April 1996 and March 1997 we examined 5093 samples of raw beef and lamb
products for the presence of E. coli O157. Samples were purchased from 81 small butchers'
shops in south Yorkshire. In March 1997 we also examined five samples of dried mint for the
presence of E. coli O157.

Strains of E. coli O157 were isolated by enrichment culture in modified buffered peptone
water followed by immunomagnetic separation and culture of magnetic beads onto cefixime
tellurite sorbitol MacConkey agar. Strains were characterized by phage typing, toxin
genotyping and plasmid analysis.

Strains of E. coli O157 were isolated from 72 (1·4%) of 5093 samples; it was isolated from
36 (1·1%) of 3216 samples of beef products and from 29 (2·9%) samples of lamb products.
The highest prevalence was found in lamb sausages and lamb burgers where E. coli O157 was
isolated from 3 (4·1%) of 73 and 18 (3·7%) of 484 samples respectively. Strains of E. coli
O157 were isolated most frequently during early summer. Strains of E. coli O157 were also
isolated from 2 of 5 samples of dried mint although we did not determine how the mint had
become contaminated.

All isolates of E. coli O157 were Verocytotoxin-producing as determined by both Vero cell
assay and DNA hybridization for the genes encoding Verocytotoxin and all were positive for
the eaeA gene. A combination of phage typing, toxin genotyping and plasmid profile
subdivided the 72 strains of E. coli isolated into 20 different subtypes, of which 18 were
indistinguishable from strains isolated previously from cattle and sheep; of these 18 strains, 8
were indistinguishable from strains isolated from human cases of infection during the study
period.
Clonal dissemination of Vibrio parahaemolyticus displaying
similar DNA fingerprint but belonging to two different
serovars (O3[ratio ]K6 and O4[ratio ]K68) in Thailand and India
Authors: CHOWDHURY N. R. , CHAKRABORTY S. , EAMPOKALAP B. , CHAICUMPA W. , CHONGSA-NGUAN M. , MOOLASART P. , MITRA R. , RAMAMURTHY T. , BHATTACHARYA S. K. , NISHIBUCHI M. , TAKEDA Y. , BALAKRISH NAIR G.
Published: July 2002

Active surveillance of Vibrio parahaemolyticus infection among hospitalized patients in
Calcutta, India, showed the appearance of the O4[ratio ]K68 serovar for the first time in March 1998
alongside the continued predominant incidence of the O3[ratio ]K6 serovar. Strains belonging to both
these serovars have been reported to possess pandemic potential. The genomes of O3[ratio ]K6 and
O4[ratio ]K68 strains and for comparison, non-O3[ratio ]K6 and non-O4[ratio ]K68 strains isolated from two
different countries, India and Thailand, were examined by different molecular techniques to
determine their relatedness. The O3[ratio ]K6 and O4[ratio ]K68 strains from Calcutta and Bangkok
carried the tdh gene but not the trh gene. Characterization of representative strains of these
two serovars by ribotyping and by arbitrarily primed-polymerase chain reaction (AP-PCR)
showed that the isolates had identical ribotype and DNA fingerprint. Pulsed-field gel
electrophoresis (PFGE) performed with the same set of strains yielded nearly similar restriction
fragment length polymorphism (RFLP) patterns for the O3[ratio ]K6 and O4[ratio ]K68 isolates from
Calcutta and Thailand. Phylogenetic analysis of the NotI RFLP showed that the O3[ratio ]K6 and
O4[ratio ]K68 strains formed a cluster with 78–91% similarity thus indicating close genetic
relationship between the two different serovars isolated during the same time-frame but from
widely separated geographical regions. The non-O3[ratio ]K6 and non-O4[ratio ]K68, in contrast, showed
different ribotype, AP-PCR and PFGE patterns.
Detection of virulence associated genes, haemolysin and
protease amongst Vibrio cholerae isolated in Malaysia
Authors: IYER L. , VADIVELU J. , PUTHUCHEARY S. D.
Published: July 2002

Eighty-four strains of Vibrio cholerae O1, O139 and non-O1/non-O139 from clinical and
environmental sources were investigated for the presence of the toxin co-regulated pilus gene,
tcpA, the virulence cassette genes ctxA, zot, ace and
cep and also for their ability to elaborate
haemolysin and protease. The ctxA and zot genes were detected using DNA–DNA
hybridization while the ace, cep and tcpA genes were detected using PCR. Production of
haemolysin and protease was detected using mammalian erythrocytes and an agar diffusion
assay respectively. Analysis of their virulence profiles showed six different groups designated
Type I to Type VI and the major distinguishing factor among these profiles was in the in vitro
production of haemolysin and/or protease. Clinical O1, O139 and environmental O1 strains
were similar with regard to presence of the virulence cassette genes. All environmental O1
strains with the exception of one were found to possess ctxA, zot and ace giving rise to the
probability that these strains may actually be of clinical origin. One strain which had only cep
but none of the toxin genes may be a true environmental isolate. The virulence cassette and
colonization factor genes were absent in all non-O1/non-O139 environmental strains but
production of both the haemolysin and protease was present, indicating that these may be
putative virulence factors. These findings suggest that with regard to its pathogenic potential,
only strains of the O1 and O139 serogroup that possess the tcpA gene which encodes the phage
receptor, have the potential to acquire the CTX genetic element and become choleragenic.
Evaluation of a serological Salmonella Mix-ELISA for
poultry used in a national surveillance programme
Authors: FELD N. C. , EKEROTH L. , GRADEL K. O. , KABELL S. , MADSEN M.
Published: July 2002

A Mix-ELISA using lipopolysaccharide antigens from Salmonella enterica serotype Enteritidis
and Typhimurium was evaluated using samples collected over time in the Danish salmonella
surveillance programme for poultry. Serological samples (n = 42813) taken from broiler-breeder
flocks after a year of bacteriological monitoring with negative results were used for calculating
the flock and individual test specificities, which were 0·997 and 0·999, respectively. Layer flocks
from the table egg sector were used for calculation of positive predictive values. In the survey,
flocks were examined for salmonella by Mix-ELISA and by faecal culture, and in case of a
positive result in either of these a repeated, serological testing was performed, and 60 animals
were organ-cultured. If one of these samplings was positive, the flock was declared salmonella
infected. In a period of 3 months, 35 flocks were found to be positive in the routine samples.
Of these, 32 were serologically positive, 2 both serologically and faecally positive and 1 flock
only faecally positive. For flocks serologically positive in the surveillance programme, a
positive-predictive value of 0·62 for organ culture positivity was found, and while considering
serological follow-up samples, the value was 0·95.
Environmental conditions in burrows of two species of African mole‐rat, Georhychus capensis and Cryptomys damarensis
Authors: Roper T. J. , Bennett N. C. , Conradt L. , Molteno A. J.
Published: July 2002

Temperature and respiratory gas (CO2 and O2) concentrations were measured in the foraging tunnels of burrows naturally inhabited by two species of southern African mole‐rats, the Cape mole‐rat Georhychus capensis and the Damaraland mole‐rat Cryptomys damarensis. Both species are completely fossorial and inhabit closed burrow systems. Tunnels of G. capensis burrows had a mean diameter of 8.7 cm and a depth, measured to the roof of the tunnel, of 6.2 cm; those of C. damarensis had a mean diameter of 6.5 cm and depth of 40 cm. In both species, the mean concentration of CO2 was higher, and mean concentration of O2 lower, in burrows than in the surrounding soil or in ambient air. Mean and minimum values of O2 were 20.4% and 19.8%, respectively, in G. capensis and 20.4% and 19.9% in C. damarensis; mean and maximum values of CO2 were 0.4% and 1.2% in G. capensis and 0.4% and 6.0% in C. damarensis. Temperature varied between 18.5 and 24.2 °C in burrows of G. capensis by comparison with an ambient range of 16.9 to 26.8 °C; and from 19.6 to 29.3 °C in burrows of C. damarensis by comparison with an ambient range of 8.6 to 30.8 °C. Thus a burrowing habit seems to offer both species protection from extremes of temperature without entailing the cost of a grossly abnormal respiratory environment. From a review of the relevant literature, we conclude that average concentrations of CO2 and O2 in mammalian burrows often do not differ greatly from ambient values. However, more work is needed to determine the respiratory gas concentrations in the immediate vicinity of active, burrowing animals.
Eviction and dispersal in co‐operatively breeding banded mongooses (Mungos mungo)
Authors: Cant Michael A. , Otali Emily , Mwanguhya Francis
Published: July 2002

The mode by which individuals disperse, and the cost of dispersal, are of great importance in attempts to understand variation in reproductive skew in animal societies. In this paper we report detailed information on dispersal and pack formation in banded mongooses Mungos mungo. Six pack fission events were recorded among 11 packs over 22 months. Pack fission occurred under two distinct circumstances. First, groups of individuals were evicted from their natal group as a result of intense aggression from other group members. A small fraction of group members was responsible for most of the aggression. Both sexes helped to attack and evict individuals from the group, and both males and females were driven out of their natal groups en masse. The second mode of pack fission occurred when groups of same‐sex individuals left their natal group voluntarily to join dispersing individuals of the opposite sex, thereby forming new packs. Dispersing groups were more frequently involved in fights with rival packs of mongooses compared to established groups, and in one instance these fights seemed to be responsible for severe injury and increased mortality among members of a dispersing group. The observations of eviction provide one line of evidence that the presence of subordinates is sometimes detrimental to dominants, contrary to the assumptions of concession models of reproductive skew.
Assessing the impact of a music festival on the emergence behaviour of a breeding colony of Daubenton's bats (Myotis daubentonii)
Authors: Shirley M. D. F. , Armitage V. L. , Barden T. L. , Gough M. , Lurz P. W. W. , Oatway D. E. , South A. B. , Rushton S. P.
Published: July 2002

The emergence of Daubenton's bats Myotis daubentonii from a priory in the north of England was recorded to assess the impact of an annual music festival. Bat emergence was related to measured environmental variables using generalized linear modelling. The temperatures inside and outside the priory were significant predictors of the numbers of bats emerging. Sunset time was a significant predictor of the time of bat emergence. The timing of bat emergence was significantly later during the music festival, but there was no significant difference in the number of bats emerging. The bats left the priory up to 47 min later on festival nights than one would expect them to emerge in the absence of the festival. The results on the patterns of bat emergence were used to make recommendations regarding the timing of the music festival in the following year to minimize detrimental impacts on the bat colony.
Group pattern and social segregation in Przewalski's gazelle (Procapra przewalskii) around Qinghai Lake, China
Authors: Lei Runhua , Jiang Zhigang , Liu Binwan
Published: July 2002

Group pattern and social segregation of the sexually size dimorphic Przewalski's gazelle Procapra przewalskii were studied for 7 years in the Qinghai Province, China. The main social units were: female groups; male groups; mixed groups. Mixed groups were the largest and most visible, whereas adult male groups were small and of similar size. The group size of the gazelle varied during different seasons (P < 0.002) and the type of social groups (P < 0.001). Mixed‐sex groups were larger than female groups or male groups across all the seasons (P < 0.008). Adult males and females were mainly in separate groups except during the rut. Groups of adult females were the most common social unit in Przewalski's gazelle, followed in frequency by adult male groups and mixed groups. From late June to late August, social separation was most pronounced. From late October to mid‐September, social segregation was not pronounced. Social segregation showed significant seasonal differences in Przewalski's gazelle (P < 0.004), especially between the rut and other seasons (P < 0.008). The pattern of social segregation of groups and behaviours observed imply that social factors play important roles in social segregation and group formation.
When the music changes, you change too: Gender and language
change in Cajun English
Authors: Dubois Sylvie , Horvath Barbara
Published: July 2002

The role of gender in language change, as discussed
in Eckert (1989a) and Labov (1990), forms the context for
an exploration of the role of gender in the development
of Cajun English. Neither Principle I, Ia, or II predicts
the role of gender in Cajun English, which leads us to
question the generalizability of the principles to the
specific sociolinguistic setting of this study—a
closed cultural enclave. The study of four sociolinguistic
variables and three generations of speakers reveals two
patterns of language change: a curvilinear or v-shaped
age pattern and a linear age pattern. These patterns relate
in a complex way to changes from above and below the level
of consciousness. We support Eckert's call for a finer
specification of the social categories but suggest alternatives
to the ethnographic method. Using a variety of sources
of information on the social life and sociohistory of three
generations, we find an intimate association between the
sociohistory of this Cajun community and the linguistic
behavior of each generation.