bluuebunny/crossref_metadata_2025 huggingface dataset:
Weak stability of the geodesic flow and Preissmann's theorem
Authors: RUGGIERO RAFAEL OSWALDO
Published: July 2002

Let $(M,g)$ be a compact, differentiable Riemannian manifold without conjugate points and bounded asymptote. We show that, if the geodesic flow of $(M,g)$ is either topologically stable, or satisfies the $\epsilon$-shadowing property for some appropriate $\epsilon > 0$, then every abelian subgroup of the fundamental group of $M$ is infinite cyclic. The proof is based on the existence of homoclinic geodesics in perturbations of $(M,g)$, whenever there is a subgroup of the fundamental group of $M$ isomorphic to $\mathbb{Z}\times \mathbb{Z}$.
Flows, random perturbations and rate of mixing
Authors: LIVERANI CARLANGELO
Published: July 2002

A new approach to the study of the rate of mixing in Anosov flows, recently proposed by Chernov, is simplified and generalized to the higher-dimensional case.
Sofic subshifts and piecewise isometric systems
Authors: GOETZ AREK
Published: July 2002

We study the natural symbolic dynamics associated with piecewise continuous, non-invertible, dynamical systems. Our study is centered primarily on the relationship between the point-set topological properties of the partition of the system and the symbolic coding. We prove that for a class of maps locally preserving distances with regular partition, the associated symbolic dynamics cannot embed subshifts of finite type of positive entropy. Hence, in particular, almost sofic subshifts obtained from the symbolic dynamics have zero entropy. However, there are examples in Euclidean spaces of systems with non-regular partitions for which the coding maps can be surjective, particularly embedding all subshifts. For all such examples, the associated group of isometries is a subgroup of $O(\mathbb{R}, N)$.
What do older people know about safety on stairs?
Authors: HASLAM ROGER A. , SLOANE JOANNE , HILL L. DENISE , BROOKE-WAVELL KATHERINE , HOWARTH PETER
Published: July 2002

This paper reports findings from three focus groups, involving 24 people, aged 65 to 79 years (20 women, four men), concerning their knowledge of safety on stairs. Findings indicate that older people use their stairs as and when necessary, but tend to avoid stair use when it becomes more difficult. The location of essential facilities in some homes (e.g. the lavatory), however, may lead to increased use of stairs for some. Despite recognition of hazardous behaviour, participants reported that they continued to engage in activities which may increase risk of falling, e.g. leaving objects on stairs and using stairs in the dark. Cleaning stairs presents problems in some cases due to difficulties with access or the need to use heavy and awkward equipment. Focus group participants recognised that medications and use of alcohol may increase the risk of falling, but it seems that individuals may not always appreciate when they personally are at increased risk. Most participants indicated they had given only limited thought to stair safety prior to the focus groups. Possibilities for prevention are reviewed, including modifications to the stair environment and equipment design, coupled with safety education, to raise awareness of risks and strategies for dealing with these.
Social isolation in old age: a qualitative
exploration of service providers'
perceptions
Authors: RUSSELL CHERRY , SCHOFIELD TONI
Published: July 2002

This paper presents findings from a qualitative study of social isolation in the
context of service provision to older people. It draws on in-depth interviews
with 18 Australian aged care practitioners about their perceptions of social
isolation among their clients. The findings show that service providers
experience significant levels of concern and frustration and a sense of
powerlessness in meeting the needs of such clients. In analysing these accounts,
the identification and management of isolation is conceptualised as a social
practice which occurs in specific relational settings. The provision of care to
lonely, isolated old people is structurally constrained in two ways. First,
because of inadequate public resource allocation, the relationship between
practitioners and older clients is dominated by time pressure and instrumentality.
Secondly, the organisational and professional rules which
service providers are required to follow shape the interpersonal relations
between practitioner and client in ways which negatively impact on the
outcomes of care for both.
Prospects for a multi-PW source using optical parametric
chirped pulse amplifiers
Authors: ROSS I.N. , MATOUSEK P. , TOWRIE M. , LANGLEY A.J. , COLLIER J.L. , DANSON C.N. , HERNANDEZ-GOMEZ C. , NEELY D. , OSVAY K.
Published: July 2002

The properties of optical parametric amplifiers
are well suited to their use as chirped pulse amplifiers
in short pulse high-power systems. In addition to the possibility
of very simple designs to extend to shorter pulses the
limits of millijoule systems, they can be used for very
high-intensity applications when used in conjunction with
narrow-bandwidth high-energy lasers. Powers exceeding 10
PW and focused intensities more than 1023 W/cm2
are predicted using existing glass laser technology.
Sagittal gait of a biped robot during the single support
phase. Part 1: passive motion
Authors: Rostami Mostafa , Bessonnet Guy
Published: July 2002

It has been shown that compass-like bipeds can walk passively
by gravity-induced motion. Similarly, it has been stated that the
unipodal phase of human gait may be regarded as a
passive motion. This paper is aimed at determining precisely to
what extent the swing phase of human-like walking can be
considered as a non-actuated motion. More specifically, a method is
developed that makes it possible to adjust initial conditions, step
length and walk speed, as well as mass and inertia
distribution of a bipedal robot, in order to generate a
passive swing motion. The approach is demonstrated by using a
7-link planar biped. Numerical simulations show that purely passive unipodal
transferring cannot be fully satisfactory. This approach is further considered
in Part 2 of the paper which consists in computing
optimal actuating joint torques to create perfectly feasible motions.
Egalitarianism: Is Leximin the Only Option?
Authors: Tungodden Bertil
Published: July 2002

The most influential egalitarian perspective is undoubtedly Rawls's (1971, 1993), which assigns absolute priority to the least advantaged in society (the difference principle). However, many have claimed that even though an egalitarian perspective should imply some priority to the worst off, the Rawlsian perspective is too demanding. One response to this criticism is to argue in favour of an egalitarian perspective that never assigns absolute priority to the worse off, but which still includes limited priority to those members of society in distributive conflicts. A different response to the demandingness criticism is to agree that the worse off should not always be given absolute priority, but to argue that there are some cases where they should be. In this paper, we elaborate on this view, and look at the possibility of deviating from the leximin approach within this category of egalitarian principles.
TESTING FOR ZERO AUTOCORRELATION WHEN THE INNOVATIONS BELONG
TO THE NORMAL DOMAIN OF ATTRACTION OF A CAUCHY LAW
Authors: Runde Ralf
Published: July 2002

We consider the asymptotic null distribution of
the empirical autocorrelation function when the innovations
of a moving average process belong to the normal domain
of attraction of a Cauchy law. A series expansion for the
density of the limiting null distribution is developed,
and some critical values of the tests are computed numerically.
Seed production and soil seed bank in three evergreen woody species from a neotropical savanna
Authors: GARCÍA-NÚŃEZ CARLOS , AZÓCAR AURA , SILVA JUAN F.
Published: July 2002

Results of a 3-y study on the populations of three evergreen woody species (Byrsonima crassifolia,
Palicourea rigida and Bowdichia virgilioides), from a regularly burnt savanna, in Venezuela, are reported. Tree density,
size structure, fruit-seed production per tree of different size classes and soil seed bank were estimated. Viable seed
production was one order of magnitude higher in B. crassifolia, which was also the only species with a permanent soil
seed bank. Seeds of B. virgilioides germinated readily after dispersal, whilst seeds of P. rigida showed an innate
dormancy synchronously released after a year. Both of the latter species seemed to maximize the first growth season
by germinating at the beginning of the favourable season. In B. crassifolia, germination proceeds with an early small
burst of germination, possibly followed by a second peak at the beginning of the next rainy season and little or no
germination thereafter. The results showed that despite the high fire frequency, the studied species produce a substantial
number of viable propagules, and have the capacity to germinate in field conditions (readiness depending on the
species). Sexual reproduction is expected, therefore, to play an important role, as suggested by their reproductive
investment, in long-term population maintenance.
Studying canopy arthropods in New Caledonia: how to obtain a representative sample
Authors: Guilbert Eric
Published: July 2002

Canopy arthropods were sampled by insecticide fogging to study their community structure in two New Caledonian primary rain forests. The representativeness of these samples was analysed by two different methods: the diversity-area relationship and the relationship between the distribution of the taxa and the sample size, using Pielou's method. The results showed that the higher the degree of aggregation, the higher must be the minimum sample size to ensure a stable distribution. In the same way, the higher the diversity index, the higher must be the sample size to ensure a representative sample of the community. In this study, 40 sample units of 1 m2 were used, although, samples of 9 to 25 m2 seem to be sufficient according to the distribution of the taxa sampled. Five to 30 m2 should be sufficient to ensure representative samples of the whole community for estimating diversity.
Decision-model construction with multilevel influence diagrams
Authors: WU X. , POH K. L.
Published: July 2002

We propose an approach to knowledge-based decision-model construction. The domain knowledge is represented in the form of multilevel influence diagrams. At each level, a regular influence diagram representing a decision model may be generated and the influence diagrams between the levels are related through a series of operations. We defined eight such operations and show that these are sufficient at the structural level to construct any target influence diagram in any practical situation. We provide a series of examples drawn from different domains on the use of multilevel influence diagrams for model construction. We also propose suggestions on providing users with guidance that can direct the model-construction procedure towards the best target model.
User-system dialogues and the notion of focus
Authors: Lecœuche Renaud , Mellish Chris , Barry Catherine , Robertson Dave
Published: July 2002

In recent years, the capabilities of knowledge-based systems to communicate with their users have evolved from simple interactions to complex dialogues. With this evolution comes a need to understand what makes a good dialogue. In this paper, we are concerned with dialogue coherence. We review the notion of focus, which partly explains this property, and its use for user-system communication. First, we examine the major theories dealing with this notion. We describe what their contribution is and how they differ. Then, we illustrate the benefits of using the notion of focus and especially the improvement in text coherence. We pay particular attention to how the notion can concretely be implemented. Its integration with other techniques and theories is described. We conclude the paper by pointing out remaining issues in the understanding of the notion of focus. The contribution of this paper is to provide a classification of the theories of focus and to show the improvements they offer in elaborate user-system dialogues.
REDIALING POLICIES: OPTIMALITY AND SUCCESS PROBABILITIES
Authors: Coffman E. G. , Gilbert E. N. , Kogan Y. A.
Published: July 2002

Since callers encountering busy signals often want to redial,
modern communication networks have been designed to provide
automatic redialing. Redialing services commonly have two
parameters: a maximum number n of retries and
a total duration τ over which retries are to be made.
Typically, retries are made at evenly spaced time intervals
of length τ/n until either the call succeeds or
n retries have failed. This rule has an obvious
intuitive appeal; indeed, among the main results of this paper
are proofs that τ/n-spacing is optimal in certain
basic models of called-number behavior. However, it is easy to
find situations where τ/n-spacing is not
optimal, as the paper verifies.

All of our models assume Poisson arrivals, but different
assumptions are studied for the call durations; for a given
mean, these are allowed to have the relatively high-variance
exponential distribution or the zero-variance distribution
concentrated at a point. We approximate the probability
of success for the Erlang loss model with c >
1 trunks, and we calculate exact probabilities of success
for the c = 1 Erlang model and the model with
one trunk and constant call durations. For the latter model,
we present two intriguing conjectures, one about the optimal
choice of τ when n = 1 and one about the optimality
of the τ/n-spacing policy. In spite of their apparent
simplicity, these conjectures seem difficult to resolve. Finally,
we study policies that continue redialing until they succeed,
balancing a short mean wait against a small mean number of retries
to success.
TRANSIENT SIMULATION VIA EMPIRICALLY BASED COUPLING
Authors: Wong Eugene W. , Glynn Peter W. , Iglehart Donald L.
Published: July 2002

In this paper we consider the use of coupling ideas
in efficiently computing a certain class of transient performance
measures. Specifically, we consider the setting in which
the stationary distribution is unknown, and for which no
exact means of generating stationary versions of the process
is known. In this context, we can approximate the stationary
distribution from empirical data obtained from a first-stage
steady-state simulation. This empirical approximation is
then used in place of the stationary distribution in implementing
our coupling-based estimator. In addition to the empirically
based coupling estimator itself, we also develop an associated
confidence interval procedure.
PINKY EXTENSION AND EYE GAZE: LANGUAGE USE IN DEAF
COMMUNITIES.Ceil Lucas (Ed.). Washington, DC: Gallaudet University
Press, 1998. Pp. ix + 285. $55.00 cloth.
Authors: Berent Gerald P.
Published: July 2002

This collection of ten articles constitutes the fourth volume of a series, Sociolinguistics
in Deaf Communities. The book's title refers to an aspect of variation in sign
languages (pinky extension) and an aspect of sign language discourse (eye gaze) and underscores
the richness and uniqueness of language use in Deaf communities around the world. The ten
articles are distributed among the book's six sections: variation, languages in contact,
language in education, discourse analysis, second language learning, and language attitudes.,
Although most of the articles focus on American Sign Language (ASL), one article explores
grammatical constraints on fingerspelled English verb loans in British Sign Language, another
examines the representation of character signs in Taiwan Sign Language (TSL) resulting from
contact between TSL and written Chinese, and a third outlines historical, political, and
educational issues affecting Irish Sign Language and the Irish Deaf community. The
book's coverage of diverse sign language communities is enhanced by an article exploring
variation in the use of “tactile ASL” by Deaf-Blind people, in which case a
language ordinarily processed in a visual modality is communicated through touch.
LINGUISTICS.H. G. Widdowson. Oxford: Oxford University Press,
1996. Pp. xiv + 134. £5.85 paper.
Authors: Keel William
Published: July 2002

This first volume in an Oxford series of introductions to language study aims to provide both
the student of linguistics and the general reader with a broader overview of linguistic science.
Widdowson attempts to present a coherent outline of the central issues in linguistics that is
accessible to the novice yet not simplistic. Following the series format, the volume is divided
into four sections: Survey, Readings, References, and Glossary.
Buzzsaws and blueprints: Commentary
Authors: GOODLUCK HELEN
Published: July 2002

The review article by Sabbagh & Gelman (S & G) on The emergence of
language (EL) mentions several criticisms of strong emergentism, the view
that language emerges through an interaction between domain-general
learning mechanisms and the environment, without crediting the organism
with innate knowledge of domain-specific rules, a view that successful
connectionist modelling is taken to support. One criticism of this view and
the support for it that connectionist modelling putatively provides has been
made frequently, and is noted by S & G: it is arguable that connectionist
simulations work only because the input to the network in effect contains a
representation of the knowledge that the net seeks to acquire. I think it is
worth adding to this another criticism that to my mind is a fundamental one,
but which has not featured so strongly in critiques of connectionism. A
primary goal of modern linguistics has been to account not merely for what
patterns we do see in human languages, but for those that we do not. The
concept of Universal Grammar is precisely a set of limitations on what
constitutes a possible human language. The kind of example used in teaching
Linguistics 101 is the fact that patterns of grammaticality are structurally,
not linearly, determined: in English we form a yes–no question by inverting
the subject NP and auxiliary verb, not by inverting the first and second words
of the equivalent declarative sentence, or the first and fifth words, or any
number of conceivable non-structural operations. Could a connectionist
mechanism learn such non-structural operations? Perhaps I have asked the
wrong people, but when I have queried researchers doing connectionist
modelling, the answer appears to be ‘yes’. If that's the case, then connectionist
mechanisms as currently developed do not constitute an explanatory
model of human language abilities: they are too powerful.
Requirements for paradigm shift
Authors: LUST BARBARA
Published: July 2002

Since Noam Chomsky's famous 1959 review of B. F. Skinner's Verbal

Behavior, a linguistically based paradigm for research in first language

acquisition has been strong, even in some senses, dominant. Even Piaget,

whose main concern was the nature of cognitive development in general, did

not deny the essential claim of a linguistically based paradigm for the study of

language acquisition: ‘I (Piaget) also agree with him (Chomsky) on the

fact that this rational origin of language presupposes the existence of a fixed

nucleus necessary to the elaboration of all languages’ (Piaget in Piatelli-Palmarini, 1980: 57). This linguistically based paradigm has led to a

developed theory of what it is that the child must acquire when s/he acquires

language, and to precise scientific hypotheses regarding the nature of this

knowledge. These hypotheses can be, and are being, subjected to empirical

test, thus advancing the scientific foundations of the field. In this paradigm,

the postulation of a ‘Language Faculty’ in the mind of the human species,

and in the child, has allowed the formulation of specific components of

linguistic knowledge which are now being tested in language acquisition as

well as in grammars of languages of the world.
Special values of the hypergeometric series II
Authors: ZUCKER I. J. , JOYCE G. S.
Published: July 2002

Several authors [1, 5, 9] have investigated the algebraic and
transcendental values of the Gaussian hypergeometric series

(formula here)

for rational parameters a, b, c and algebraic and rational values of
z ∈ (0, 1). This led to several new identities such as

(formula here)

and

(formula here)

where Γ(x) denotes the gamma function. It was pointed out by the present authors
[6] that these results, and others like it, could be derived simply by combining certain
classical F transformation formulae with the singular values of the complete elliptic
integral of the first kind K(k), where k denotes the modulus.

Here, we pursue the methods used in [6] to produce further examples of the type
(1·2) and (1·3). Thus, we find the following results:

(formula here)

The result (1·6) is of particular interest because the argument and value of the F
function are both rational.
Ideals with bounded approximate units in L1-algebras
of locally compact groups
Authors: KANIUTH EBERHARD
Published: July 2002

We show that for an arbitrary locally compact group G and for E in a certain
class of closed subsets of the primitive ideal space of
L1(G), the kernel k(E) has a
bounded approximate unit. This generalizes some well-known previous results.
Vessel Traffic Services (VTS): Are We
Ready For The New Millenium?
Authors: Hughes Terry
Published: July 2002

In 1948, the port of Liverpool
was probably the
pioneer of European VTS, when they set up a radar station, in
order to facilitate
the boarding of pilots from the cutter. In 1951, Long Beach in California

established a radar and VHF to facilitate port operations. Le
Havre established
another system and so, gradually, other ports followed. At this time commercial

radar was comparatively new, and made it possible for the first time, under

almost all weather conditions, to observe vessel traffic from the shore.
In
combination with VHF radio, a traffic surveillance system was
achieved and real-
time information exchange between the shore and ships became possible.

Nevertheless, it was not until 1985 that the role of VTS in connection
with
navigation safety, traffic efficiency and environmental protection gained

international recognition. This recognition is contained in an IMO resolution,

which constitutes the VTS guidelines.
Aircraft Collision Risks at the Start of the 21st Century
Authors: Cockburn David
Published: July 2002

Much has been written on the subject of aircraft collision risk
and
avoidance over the past 50 years. As a particularly interested aviator
(a military and
civilian pilot for the last 32 years), with a limited memory for the mathematics
I studied
at school, I have read several of these treatises with interest. I do,
however, feel that
the advent of modern, accurate navigation systems has changed the distribution
of
collision causes radically. We should be concentrating, not on the risks
of aircraft
accidentally flying into each others' paths, but on the
risks of them deliberately doing so.

That statement requires explanation, of course. There is a risk of one
pilot
deliberately and willingly putting his aircraft in
the path of another (a terrorist or suicide
for example), but the risk is considerably less than that of a pilot who

does it unwillingly, but equally deliberately.
The Ellenberg index of temporal change in vascular plants (Änderungstendenz) tested in southern Sweden
Authors: OREDSSON ALF
Published: July 2002

In Sweden, public awareness of change in the environment has increased in recent decades (Gillberg 1999). An important tool which contributed to an understanding of how the flora is affected by changes in the environment was created by Ellenberg (1974). Six ecological factors, namely light, temperature, continentality, moisture, reaction and nitrogen, were each divided into 9 (in the case of moisture 12) so-called indicator values. A species given a low value occurs mainly where the factor is less pronounced, and vice versa, species in light class 1 prefer full shadow, 5 half shadow, and 9 full light.
The duty of humanity before the environment: a Russian Catholic viewpoint
Authors: SCHREIDER JULIUS
Published: July 2002

Moral relations with nature, I contend, are connected with our duty before a social environment. Elsewhere I have defined duty as '‘what is recommended by moral or religious law, and what one has to do in order to be in agreement with one's conscience’ (Schreider 1994, p. 27). Our highest duty, I have argued, is social duty, or duty towards humankind as a whole; but this kind of duty, in fact all so-called ‘moral duty’, is not natural, or predetermined by our natural essence (Schreider 1994, p. 99; Schreider 1996). Now, our social duties, not any ‘natural duties’, have implications for our relations with the environment. This is so, significantly, because no natural reasons exist for there to be harmony between humanity and the environment. Indeed, if such natural processes did exist, why should we invoke the need of duty towards nature, because whatever we did, would not we be doing things naturally? To engage duty, in fact, already presupposes the absence of such natural relations, and turns the spotlight on acts of free will, or human decisions and responsibilities. Our experience of history and social relations is such that we humans are more than often found independent of, sometimes even going against, the perceived ‘natural stream of events’, by either creating or solving environmental problems. The claims of duty, then, have to be clarified on any environmental philosophy, because there is a common trap of letting nature dictate morality, a problem apparent in neo-Spencerian ethics (cf. Trompf 1990, pp. 17-20). As I have not long ago maintained (Schreider 1994, p. 107), duty is a basis for our rational actions, designs and relations, and duty, we would thus rightly expect, has moral foundations, even (more controversially) religious ones. Human responsibility for nature loses any sense unless we presuppose it to depend on free will. Otherwise we are left with a predetermined course of events, not duty, and I hold we would even deny self-existence, ascribing our actions not to ourselves but to some ‘objective reasons’ (Schreider 1996).
Towards a universal recognition of environmental responsibilities
Authors: WESTING ARTHUR H.
Published: July 2002

It was just over 50 years ago that the fledgling United Nations expressed its revulsion against the German wartime atrocities, doing so by means of a Universal Declaration of Human Rights (UNGA 1948). The 30 principles declared in 1948 were eventually solidified in 1966 via two widely-adopted international covenants (Afghanistan et al. 1966a, b). However, the need for environmental conservation was nowhere directly mentioned in any of these three landmark documents. Nonetheless, their fundamental principle that every human being has the inherent right to life (UNGA 1948, Article 3; Afghanistan et al. 1966a, Article 6.1) has been inferred to imply the need for an environment adequate for the fulfillment of that right (Westing 1993).
Viewpoint-based shape recovery from multiple views
Authors: AKGUNDUZ ALI , ZETU DAN , BANERJEE PAT
Published: July 2002

This paper describes an algorithm for surface reconstruction
from a set of scattered three-dimensional points extracted
from an image sequence. In this process, additional information
(such as location of the viewpoints and the points visible
from a particular viewpoint) is available and can be exploited
for accurately recovering the shape of the objects portrayed
in the images. Initially, the set of points is subjected
to a Delaunay triangulation that fills the convex hull
of the set of points with disjoint tetrahedra. The key
idea of the shape recovery algorithm is to eliminate triangles
that obstruct the visibility of points from certain viewpoints,
whose locations are known from the image acquisition process.
The major contribution of this paper is that we have been
able to design an algorithm for surface reconstruction
that handles a wide variety of shapes, as opposed to currently
existing techniques.
Control sequence generation in multistage fuzzy control
systems for design process
Authors: MILATOVIC MILAN , BADIRU ADEDEJI B.
Published: July 2002

The purpose of this study is to investigate and
optimize the dynamics of state transitions during a process
of multistage fuzzy control systems. A variation of the
methodology for solving the Vehicle Routing Problem,
known as the Savings Method, is applied to finding
a sequence of controls to maximize the overall performance
of multistage control processes. The Savings Method
has been modified into a heuristic to traverse state precedence
when transitioning from one known system state to another.
In addition, the procedure allows for imposing of two different
types of precedences (mandatory and optional) among transition
states, as well as a pair of fuzzy constraints and goals
throughout each stage of the process. As the control of
the system progresses, fuzzy goals may be preset or introduced
interactively.
An outbreak of rubella in British troops in Bosnia
Authors: ADAMS M. S. , CROFT A. M. J. , WINFIELD D. A. , RICHARDS P. R.
Published: July 2002

An outbreak of rubella in April 1996 involved four male British

soldiers deployed to

Bosnia–Herzegovina. All were helicopter ground crew who were

members of the same unit and

who periodically travelled to and worked at forward air refuelling

stations in Bosnia. There

was a potential for spread of the infection to adjacent British units,
to

troops of other nations

in the peacekeeping force, and also to the local civilian population.

The British force included

620 female personnel, some of whom may have been non-immune to rubella.
One pregnant

British servicewoman was repatriated to UK for her own protection.

There was a potential

health risk, including the possibility of congenital rubella syndrome,

in the non-immune wives

and partners of deployed male personnel, as a result of contact during

the mid-tour home

leave of the husbands or partners. The outbreak was monitored through

a medical surveillance

system known as ARRC 97, and was contained by prompt and rigorous

control measures. This

outbreak shows the importance of effective surveillance and of good

microbiology laboratory

support during military operations. The role of immunization against

rubella during future military deployments is discussed.
The prevalence of Vibrio spp. in drinking water and
environmental samples in Vellore South India
Authors: THOMSON C. J. , JESUDASON M. V. , BALAJI V. , MALATHI B. , MUKUNDAN U. , AMYES S. G. B.
Published: July 2002

The prevalence of Vibrio cholerae in drinking water, lakes

and sewage outfalls during July and
August 1996 in Vellore, India was determined. Drinking water samples were
collected on single
occasions from 12 sites in different geographic areas of the town where
cholera had been
reported. Samples of water, plankton and sediment were collected from fixed
sites at three
lakes on three occasions separated by at least 3 days during the course
of the study. Samples
from open sewers were taken from two representative sites in four areas
of the town. Bacteria
isolated from samples were identified by standard biochemical tests
and isolated strains of V.
cholerae tested for their ability to agglutinate O1 and O139
antisera. Water samples from lakes
were also tested for the presence of V. cholerae O1 and
O139 by fluorescent antibody staining.
Non-O1, non-O139 strains of V. cholerae were detected
in 41% of drinking water samples and
100% of water, sediment and plankton samples from the test lakes. Eighty-seven
per cent of
open sewers sampled contained viable non-O1, non-O139 V. cholerae.

Fluorescent antibody
staining gave positive results for V. cholerae O1 and
O139 for all water samples from the three
lake sites. Strains of Aeromonas spp. were isolated from
58% of drinking water samples and
from 66% of sediment, 77% of plankton and 55% of water samples from lakes.
All open
sewers sampled contained Aeromonas spp. PCR amplification employing
specific primers
demonstrated that none of the non-agglutinating V. cholerae
isolates contained the ctx operon.
The non-O1, non-O139 V. cholerae isolates showed different patterns

of antibiotic resistance to
ampicillin, ciprofloxacin, chloramphenicol, tetracycline and trimethoprim.
A survey of risk factors for cryptosporidiosis in New York
City: drinking water and other exposures
Authors: DAVIS L. J. , ROBERTS H. L. , JURANEK D. D. , FRAMM S. R. , SOAVE R.
Published: July 2002

We conducted a survey to determine the prevalence of known
and theoretical exposure risks
for cryptosporidiosis among selected New York City residents. Subjects
were recruited from
outpatients attending either a practice for persons with HIV
infection (n=160), or other
medical practices (n=153), at The New York
Hospital–Cornell Medical Center. Despite a
greater concern for waterborne infection, 82% of HIV-infected subjects
reported consuming
municipal tap water compared to 69% of subjects from other medical clinics
(OR 2·1, 95%
CI 1·2–3·6, P=0·006). Although 18%
and 31%
of subjects, respectively, denied any tap water
consumption at home or work, all but one from each cohort responded positively
to having at
least one possible alternate source of tap water ingestion
such as using tap water to brush teeth
or drinking tap water offered in a restaurant. 78% and 76% of subjects,
respectively, had at
least one potential risk for exposure other than municipal water consumption,
such as
swimming in pools or contact with animals. Our findings indicate that it
is possible to stratify
the population into subsets by the amount of tap water consumed. This suggests
that an
observational epidemiologic study of the risk of contracting cryptosporidiosis
from everyday
tap water consumption is feasible.
Factors associated with pharyngeal carriage of Neisseria
meningitidis among Israel Defense Force personnel at the end
of their compulsory service
Authors: BLOCK C. , GDALEVICH M. , BUBER R. , ASHKENAZI I. , ASHKENAZI S. , KELLER N.
Published: July 2002

In this 1 year cross-sectional study of personnel being discharged
from compulsory military
service, an available database of health-related information was used to
examine the
association of meningococcal carriage with socio-demographic factors. A
representative,
systematic sample of 1632 personnel was interviewed and had throat cultures
taken. The
overall meningococcal carriage rate was 16%. Serogroups B and Y accounted
for 76% and
13% of the isolates respectively. In univariate analysis, carriage was
associated with male
gender (P<0·0001), <12 years school education (P=0·002),

smoking (P=0·014), and service
at a ‘closed’ base, reflecting greater interpersonal contact

(P<0·0001). In multivariate analysis,
only service on a closed base and male gender retained significance. School
education of <12
years remained significant for females only. Variables not associated with
carriage included
number of siblings, intensity of smoking, and use of the contraceptive
pill. In this setting,
meningococcal carriage was associated with the type of base on which soldiers
served; and
smoking was not an independent risk factor for carriage.
Enteropathogenic bacteria in faecal swabs of young children
fed on lactic acid-fermented cereal gruels
Authors: KINGAMKONO R. , SJÖGREN E. , SVANBERG U.
Published: July 2002

The influence of consumption of a lactic acid-fermented cereal
gruel togwa with pH[les ]4 on the
presence of faecal enteric bacteria such as campylobacter, enterohaemorrhagic
Escherichia coli
(EHEC[ratio ]O157), enterotoxigenic Escherichia coli (ETEC),
salmonella and shigella was evaluated.
Under 5 years old healthy children listed in an ascending order of age
were alternatively
assigned and given either a lactic-acid fermented cereal gruel togwa
(test diet) or an
unfermented cereal gruel uji (control diet) once a day for 13
consecutive days. The presence of
the enteropathogens was examined in rectal swabs collected from the children
at baseline
(before feeding session started), on days 7 and 13, and additionally 14
days (follow-up day)
after the feeding session had stopped. The swabs were cultured on to different
optimal media
for respective enteropathogen and confirmed by standard microbiological
and serological
methods. Campylobacter spp. dominated among the enteropathogens
(62% out of total)
followed by Salmonella spp., ETEC and Shigella spp. Children
with isolated enteropathogens
in the togwa group was significantly reduced (P<0·001)
from 27·6% at baseline to 7·8, 8·2 and
12·7% on days 7, 13 and follow-up day, respectively. The effect
was more pronounced in those
children taking togwa >6 times during the study period. In
the control group, there was a
slight decrease from 16·7% at baseline to 11·4% on day 7
and 8·1% on day 13. On the
follow-up day, enteropathogens were found in 22·6% of the children,
which was significantly
higher than in those children taking togwa >6 times. We conclude,
that regular consumption
of togwa with pH[les ]4, once a day, three times a week may help
to control intestinal
colonization with potential diarrhoea-causing pathogens in young children.
Hepatitis B and C among Berlin dental personnel: incidence, risk factors, and effectiveness of barrier prevention measures
Authors: AMMON A. , REICHART P. A. , PAULI G. , PETERSEN L. R.
Published: July 2002

A study of 215 Berlin dentists and 108 dental assistants recruited at the 1997 Berlin Dental
Society meeting assessed their occupational risk of hepatitis B virus (HBV) and hepatitis C
virus (HCV) infection, HBV vaccine coverage, and barrier prevention methods used. Among
dentists, 7% (95% CI 4–11) and 0·5% (95% CI 0–3) had serological evidence of previous
HBV and HCV infection, respectively. Similar figures for dental assistants were 1% (95% CI
0–5) and 0% (95% CI 0–4). Only 74% of dentists and 63% of dental assistants reported HBV
vaccination. Approximately half always used gloves, eye glasses, or face masks. HBV
unvaccinated dentists whose patients had HBV risk factors had a greater risk of HBV
infection; those who always wore face masks were at lower risk (OR 0·2, 95% CI 0·02–0·98).
These data indicate that among Berlin dentists, the HCV risk was lower than that of HBV and
that face masks may have lowered the risk of HBV. The use of eye glasses or gloves did not
appear to lower the risk of HBV acquisition in this population.
Male and female styles in 17th century correspondence: I THINK
Authors: Palander-Collin Minna
Published: July 2002

When 17th century personal correspondence was studied,
it was observed that women used the evidential expression
I THINK more often than men. A closer analysis
showed that women also used other 1st person evidential
verbs as well as the 1st and 2nd person pronouns more frequently
than men. This male/female difference was maintained even
in different registers, although both sexes have higher
frequencies of I THINK in more intimate circumstances,
such as when the informants are writing to their friends
or close family members. The male/female differences in
frequencies are explained as a difference in the style
of communication. Women's style is more “involved”
and interactive: personal point of view is frequently expressed,
and both the writer and the addressee are overtly included
in the communication situation. Interestingly, similar
differences have also been found in Present-Day English.
Asymptotic behaviour of the thin film equation in bounded domains
Authors: BOWEN M. , KING J. R.
Published: July 2002

We investigate the extinction behaviour of a fourth order degenerate diffusion equation in a
bounded domain, the model representing the flow of a viscous fluid over edges at which zero
contact angle conditions hold. The extinction time may be finite or infinite and we distinguish
between the two cases by identification of appropriate similarity solutions. In certain cases,
an unphysical mass increase may occur for early time and the solution may become negative;
an appropriate remedy for this is noted. Numerical simulations supporting the analysis are
included.
The temperature-jump problem in rarefied-gas dynamics
Authors: BARICHELLO L. B. , SIEWERT C. E.
Published: July 2002

An analytical version of the discrete-ordinates method is used here to solve the classical
temperature-jump problem based on the BGK model in rarefied-gas dynamics. In addition to
a complete development of the discrete-ordinates method for the application considered, the
computational algorithm is implemented to yield very accurate results for the temperature
jump and the complete temperature and density distributions in the gas. The algorithm is
easy to use, and the developed code runs typically in less than a second on a 400 MHz
Pentium-based PC.
Inductive benchmarking for purely functional data structures
Authors: MOSS GRAEME E. , RUNCIMAN COLIN
Published: July 2002

Every designer of a new data structure wants to know how well it performs in comparison
with others. But finding, coding and testing applications as benchmarks can be tedious and
time-consuming. Besides, how a benchmark uses a data structure may considerably affect
its apparent efficiency, so the choice of applications may bias the results. We address these
problems by developing a tool for inductive benchmarking. This tool, Auburn, can generate
benchmarks across a wide distribution of uses. We precisely define ‘the use of a data structure’,
upon which we build the core algorithms of Auburn: how to generate a benchmark from a
description of use, and how to extract a description of use from an application. We then apply
inductive classification techniques to obtain decision trees for the choice between competing
data structures. We test Auburn by benchmarking several implementations of three common
data structures: queues, random-access lists and heaps. These and other results show Auburn
to be a useful and accurate tool, but they also reveal some limitations of the approach.
Compilation and equivalence of imperative objects
Authors: GORDON ANDREW D. , HANKIN PAUL D. , LASSEN SØREN B.
Published: July 2002

We adopt the untyped imperative object calculus of Abadi and Cardelli as a minimal
setting in which to study problems of compilation and program equivalence that arise when
compiling object-oriented languages. We present both a big-step and a small-step substitution-based operational semantics for the calculus. Our first two results are theorems asserting the
equivalence of our substitution-based semantics with a closure-based semantics like that given
by Abadi and Cardelli. Our third result is a direct proof of the correctness of compilation to
a stack-based abstract machine via a small-step decompilation algorithm. Our fourth result
is that contextual equivalence of objects coincides with a form of Mason and Talcott's CIU
equivalence; the latter provides a tractable means of establishing operational equivalences.
Finally, we prove correct an algorithm, used in our prototype compiler, for statically resolving
method offsets. This is the first study of correctness of an object-oriented abstract machine,
and of operational equivalence for the imperative object calculus.
The web’s potential for language learning: the
student’s perspective
Authors: FELIX USCHI
Published: July 2002

This paper reports on a large-scale study carried out in four
settings that investigates the potential of the Web as a medium of language
instruction, both to complement face-to-face teaching and as a stand-alone course.
Data was collected by questionnaires and observational procedures to ascertain
student perceptions of the usefulness of Web-based learning, their views on its
advantages and disadvantages, their personal comfort and enjoyment when working
with the Web, their preferred mode of delivery, their evaluation of the quality
of resources used, and their learning strategies and study preference. Results
showed that students were on the whole positively inclined to working with the
Web and found it useful, with the majority preferring to use the Web as an add-on
to face-to-face teaching. Reported advantages fell into the broad categories of
time flexibility, reinforced learning, privacy and wealth of information;
disadvantages into distraction, absence of teacher and personal interaction and
lack of speaking practice. Significant differences for age and gender were found
relating to clarity of objectives, number of hours worked, mode of delivery,
perception of comfort and appreciation of graphics. Very few significant findings
relating to strategy strength emerged.
Arterial compliance in older people
Authors: Rajkumar C. , Bonapace S. , Bulpitt C. J.
Published: July 2002

Introduction

Longevity has lengthened in recent times. This has resulted in an increase in the elderly population, with life expectancy at birth in men in the UK being approximately 72.5 years and women, 78.5 years. Despite the risk of death from cardiovascular diseases decreasing in the past 40 years, these still continue to be the largest cause of mortality in the elderly. Cardiovascular mortality and morbidity are lower in women. However, this is not true in the later years of life. After the age of 80, the risk of cardiovascular problems increases to that of men. The cardiovascular changes occurring with aging consists of changes in the heart and arterial system.
Outcome measures in the rehabilitation of older adults
Authors: MacKnight Chris , Powell Colin
Published: July 2002

Why measure?

Before we consider what to measure and how to measure outcomes in the rehabilitation of frail older adults, an antecedent question is, why measure these things? Without an answer satisfactory for both measurers and measured, much effort and ingenuity will be expended with resultant perspiration and exasperation and little else.

Traditionally, medical care, i.e. that identified by physicians, has assumed that its principal objective was patient care, i.e. that appreciated by patients. Outcomes of care from the viewpoint of the patient, of his or her informal supporters, of the involved health care professionals, and of the health care delivery system have to be clarified and made operationally explicit. This recognition requires definition and measurement. Thus a powerful reason for measuring outcomes for recipients and providers of health care, as well as the health care delivery system, is to know what is happening (the descriptive question) and with what effect (the analytical question).
Skin diseases
Authors: Hughes Bronwyn R
Published: July 2002

Despite the increasing numbers of elderly subjects in society, the characteristic changes of old age such as the presence of wrinkles and grey hair still carry social stigma. This is taken advantage of by a cosmetics industry which produces enormous numbers of products to disguise aging. Contrary to popular belief, elderly people are often anxious to look attractive. Elderly patients present to dermatologists with a variety of skin problems. These may be directly related to aging (e.g. carcinogenesis) or may be common problems whose clinical expression, physical and emotional consequences and management may be altered by the age of the patient. A survey of elderly patients by Beauregard and Gilchrest revealed that two-thirds had symptoms relating to their skin and that this rose to 83% in subjects over 80 years.
Cognitive rehabilitation and traumatic brain injury
Authors: Broek Martin D van den
Published: July 2002

The last twenty years have seen a rapid expansion in the provision of post-acute rehabilitation services for patients with traumatic brain injuries (TBI) in North America, although such provision remains limited in Britain. These developments have been precipitated by a growing appreciation by health purchasers and providers of the neuropsychological and social sequelae of TBI and demands by patients and their families for effective treatment. Most investigations have found that the majority of TBI survivors are young males under the age of thirty and that by far the most common cause of TBI is road traffic accidents. Typically the frontal and temporal lobes of the brain suffer the greatest impact and survivors subsequently present with deficits affecting memory and new learning, attentional dysfunction and impaired planning and organizational skills.