bluuebunny/crossref_metadata_2025 huggingface dataset:
Le Corbusier and the creative use of mathematics
Authors: LOACH JUDI
Published: July 2002

For the artist, mathematics does not consist of the various
branches of mathematics. It is not
necessarily a matter of calculation but rather of the presence of a sovereign
power; a law of
infinite resonance, consonance, organisation. Rigour is nothing other
than that which truly results
in a work of art, whether it be a Leonardo drawing, or the fearsome exactness
of the Parthenon
(comparable in the cutting of its marble even with that of
machine-tools), or the implacable and
impeccable play of construction in the cathedral, or the unity in a
Cézanne, or the law which
determines a tree, the unitary splendour of roots, trunk, branches, leaves,
flowers, and fruit.
Chance has no place in nature. Once one has understood what mathematics
is – in the
philosophical sense – thereafter one can discern it in all
its works. Rigour, and exactness, are the
means behind achieving solutions, the cause behind character, the rationale
behind harmony.

Le Corbusier, 1948

Probably everyone reading this article has heard of Le Corbusier, no
doubt the most
famous architect this century, but the images he will arouse in their minds
may vary
greatly. Some will blame him for those theories promoting standardized
high rise
construction, which have dominated town planning policy in post-war Europe.
Others will
admire his highly individual, sculptural buildings such as the church at
Ronchamp
(1950–55) (see Figure 1), the revolutionary public housing scheme
of the
Unité d'Habitation
at Marseilles (1946–52) (Figure 2), its ground-level pillars
(pilotis) and roof-level service
stacks alike transformed into enigmatic statues, or his pre-war Purist
villas in the Paris
suburbs (1920s). His work displayed a wide variety of forms and spaces
at any one time,
and his career spanned almost sixty years, during which he was constantly
questioning, and
reformulating theories, and in consequence changing his formal language.
Institutions and Environmental Performance in Seventeen Western Democracies
Authors: SCRUGGS LYLE A.
Published: July 2002

This article examines the relationship between national political and economic institutions and environmental performance since the early 1970s in seventeen OECD countries. After presenting hypotheses about some of the effects of the most important structural and institutional variables on performance, I test these hypotheses using a multiple regression analysis. I find that neo-corporatist societies experience much better environmental outcomes than more pluralist systems. However, neither the degree of ‘consensual’ political democracy nor traditional political factors can explain much variation in environmental performance. These relationships hold even after controlling for other structural factors such as income and manufacturing intensity. The results are robust despite perennial small-n statistical problems encountered in comparative political economy.
Legal advice privilege: a matter of substance
Authors: Andrews N.H.
Published: July 2002

THE doctrine of legal professional privilege comprises two categories. The first, “legal advice” privilege, protects communications between client and lawyer for the purpose of eliciting or giving legal advice. The second category, known as “litigation” privilege, concerns communications between a lawyer and a non-party, or a client and a non-party, if made predominantly in respect of litigation, criminal or civil, whether pending or contemplated, and whether in England or elsewhere. An example of this second category is a confidential “sounding” by a client or lawyer of a potential witness.
THE CROSSED PRODUCT BY A POINTWISE UNITARY ACTION ON A C*-ALGEBRA WITH CONTINUOUS TRACE
Authors: Deicke Klaus
Published: July 2002

Let $G$ be a locally compact group, $A$ a continuous trace $C^*$-algebra, and $\alpha$ a pointwise unitary action of $G$ on $A$. It is a result of Olesen and Raeburn that if $A$ is separable and $G$ is second countable, then the crossed product $A\times_\alpha G$ has continuous trace. We present a new and much more elementary proof of this fact. Moreover, we do not even need the separability assumptions made on $A$ and $G$.

AMS 2000 Mathematics subject classification: Primary 46L55
On the estimation of ancestral population sizes of modern humans
Authors: YANG ZIHENG
Published: July 2002

The theory developed by Takahata and colleagues for estimating

the effective population size of

ancestral species using homologous sequences from closely related

extant species was extended to

take account of variation of evolutionary rates among loci. Nuclear

sequence data related to the

evolution of modern humans were reanalysed and computer simulations

were performed to

examine the effect of rate variation on estimation of ancestral

population sizes. It is found that the

among-locus rate variation does not have a significant effect on

estimation of the current

population size when sequences from multiple loci are sampled

from the same species, but does

have a significant effect on estimation of the ancestral population

size using sequences from

different species. The effects of ancestral population size,

species divergence time and among-locus

rate variation are found to be highly correlated, and to achieve

reliable estimates of the ancestral

population size, effects of the other two factors should be estimated independently.
Radioprotective effect of misoprostol on mouse
spermatogonial stem cells
Authors: DE ROOIJ DIRK G. , VAN BEEK MARIA E. A. B. , RUTGERS DERK H. , VAN DUYN-GOEDHART ANNEMARIE , VAN BUUL PAUL P. W.
Published: July 2002

The radioprotective effects of misoprostol, a synthetic stable
analogue of prostaglandin E1, on
spermatogonial stem cells of C3H/HeH×101/F1 hybrid mice (3H1)
were analysed by establishing
dose–response relationships for stem cell killing by X-rays in mice
that were pretreated with
misoprostol. Spermatogonial stem cell killing was studied through determination
of the percentage
of tubular cross-sections showing repopulation at 10 days after irradiation.
In control mice, the D0
values ranged between 1·7 and 3·6 Gy, dependent on the stage
of the cycle of the seminiferous
epithelium the cells were in. As found previously, proliferating spermatogonial
stem cells were
much more radioresistant than quiescent stem cells. In the misoprostol-pretreated
animals the
spermatogonial stem cells were more radioresistant, the D0 values
ranging from 3·6 to 5·0 Gy. Both
proliferating and quiescent spermatogonial stem cells were protected by
misoprostol. As the
dose–response curves in control and misoprostol-pretreated mice showed
about the same
extrapolation number to the y-axis it was concluded that the misoprostol
pretreatment did not
alter the kinetics of the repopulation process.
Genetic variation and natural selection on blue tit body
condition in different environments
Authors: MERILÄ J. , PRZYBYLO R. , SHELDON B. C.
Published: July 2002

An increasing amount of evidence indicates that different forms
of environmental stress influence
the expression of genetic variance in quantitative traits and, consequently,
their evolvability. We
investigated the causal components of phenotypic variance and natural selection
on the body
condition index (a trait often related to fitness in wild bird populations)
of blue tit (Parus
caeruleus) nestlings under contrasting environmental conditions. In
three different study years,
nestlings grown under a poor feeding regime attained lower body condition
than their full-sibs
grown under a good feeding regime. Genetic influences on condition were
large and significant in
both feeding regimes, and in all three study years. However, although estimates
of additive genetic
variance were consistently higher in the poor than in the good environment,
heritability estimates
for body condition index were very similar in both environments due to
higher levels of
environmental variance in the poor environment. Evidence for weak genotype×environment

interactions was obtained, but these contributed little to variance in
nestling condition. Directional
natural selection on fledging condition of nestlings was detected, and
there were no indications of
year or environmental effects on the form and intensity of selection observed,
in a sample of 3659
nestlings over four years. However, selection on fledging condition was
very weak (standardized
selection gradient, β=0·027±0·016 SE),
suggesting that, in the current population, the large
additive genetic component to fledging condition is not particularly surprising.
The results of these
analyses are contrasted with those obtained for other populations and species
with similar life-histories.
Abstracts of papers presented at the ninth Mammalian Genetics and Development Workshop
held at the Institute of Child Health, University College London on 14–16 December 1998
Authors: COPP ANDREW J. , STEPHENSON DENNIS A.
Published: July 2002

Sponsored by: The Wellcome Trust and B & K Universal Group Limited
PRIVATE CONSCIENCE AND PUBLIC DUTY IN THE WRITINGS

OF CHARLES I
Authors: SHARPE KEVIN
Published: July 2002

It has become orthodox to criticize Charles I for his failure as

a politician. Such

criticism is both accurate and anachronistic. It fails to appreciate that

for Charles the business of

kingship was not the art of politics but the pursuit of conscience. Charles

took to heart his father's

injunctions to follow conscience and he obeyed them rigidly. Through the

study of speeches, letters and

royal prayers this essay examines the centrality of conscience to Charles

I's kingship. It shows how the

divisions of the 1640s led him temporarily to abandon conscience, and

finally it studies the king's self-construction as the conscience
of

the commonwealth – the central stance of the Eikon Basilike.
TOURNAI AND THE ENGLISH CROWN, 1513–1519
Authors: DAVIES C. S. L.
Published: July 2002

The English occupation of Tournai has recently generated far-reaching
claims about
its importance; allegedly Tournai provided a foretaste of certain
developments of the Henrician
Reformation. This article argues that Tournai was treated as an integral

part of Henry VIII's
‘kingdom of France’ and its status consistently distinguished
from
that of the English kingdom. It was
not, as has been suggested, granted representation in the English parliament.
The argument that
advanced ideas of ‘sovereignty’ derived from fifteenth-century

French thought entered into English
political discourse through Tournai is also countered. Important
jurisdictional points were raised,
notably over the administration of the bishopric, involving three
powers, England, France, and the
Habsburg government of Flanders. But Henry's insistence on his
rights as a sovereign prince were
directed against France, not, as has been claimed, against the
papacy. Nothing in Henry's dealings
with Tournai transcended well-established English doctrine and practice
about the relationship
between the political authority and the church. Nor did Henry's
treatment of the conquered town evoke
novel doctrines of royal power; it followed closely precedents set
by Henry V. The conquest of Tournai
increased the self-confidence of Henry VIII's government in both
domestic and international affairs;
but largely through Henry's belief that he was successfully emulating

the military achievement of
Henry V, not through any input of novel political doctrine.
THE ‘BONAPARTE OF FREE TRADE’
AND THE ANTI-CORN LAW LEAGUE
Authors: TURNER MICHAEL J.
Published: July 2002

This article seeks to re-balance the canon of anti-corn law leadership
by examining the
ideas and activities of Thomas Perronet Thompson. A relatively neglected
figure in modern accounts
of the Anti-Corn Law League and repeal in 1846, Thompson was acknowledged
in his own lifetime
as an outstanding campaigner whose role in the work of the League and in
the mobilization of opinion
was exceptional. This article investigates Thompson's free trade principles,
and uses his pamphlets,
articles, correspondence, speeches, and organizational efforts to create
a vivid impression of repeal
agitation in the 1830s and 1840s. Personal relationships between anti-corn
law leaders are examined,
as are the links between their movement and such other phenomena as Chartism
and the campaign for
factory reform. The article stresses the central importance of Thompson
in the achievement of repeal
and, by using his contribution as a point of entry, seeks to promote a
deeper understanding of the anti-corn law creed and its modes of organization, campaigning, publicity, and
propaganda.
PUNT AND AKSUM: EGYPT AND THE HORN OF AFRICA
Authors: PHILLIPS JACKE
Published: July 2002

The ancient Egyptians tended to consider both their immediate and
more

remote neighbours either as excellent sources of luxury trade items and

slaves, at times of political power and strength, or as uncivilized forces

threatening to destroy and overwhelm the Egyptian Nile Valley. This was

true not only of cultures within Africa; those in the Aegean, the Levant,

Cyprus and Mesopotamia also were viewed from one or the other perspective,

occasionally both at the same time. All these, together with Nubia and
Libya,

have received much scholarly attention and, whilst we probably will never

fully understand their ancient relationship to Egypt, we have a fairly
good

idea, ‘hearing’ the story from both sides when surviving evidence
allows,

what their attitudes towards each other were at various times in their
history.

This article deals with what is surely the least investigated aspect
of

ancient Egyptian relations with its neighbours, simply because we know

comparatively little about the two major successive cultures concerned
–

Punt and Aksum – in the ancient world.
‘DISCIPLINE WITHOUT OPPRESSION’: SEQUENCE,
TIMING AND MARGINALITY IN SOUTHERN
RHODESIA'S POST-WAR DEVELOPMENT REGIME
Authors: WORBY ERIC
Published: July 2002

In 1941, Prime Minister Godfrey Huggins of Southern Rhodesia presented
a prescription for his colony's survival under white stewardship. ‘It is
essential for the preservation of the European civilization,’ he wrote, ‘that
the African should be advanced’. A decade later, the variables in this
explicitly racial equation had been fleshed out, and black Southern
Rhodesians were subjected to a revised and actively interventionist regime of
governance – a regime that we would immediately recognize today as one of
‘development’. As such, it had much in common with the forms and
strategies through which ‘development’ was pursued elsewhere in the late
colonial world: its local theorists sought justification in the sciences of nature
and society, while its political apologists claimed to be twinning moral uplift
with the material improvement of those ‘natives’ supposedly entrusted to
their civilized care.
The transfer of arsenic to sheep tissues
Authors: BERESFORD N. A. , CROUT N. M. J. , MAYES R. W.
Published: July 2002

There is the potential for arsenic to enter the human food chain via ingestion by grazing animals. Data on the transfer of arsenic to ruminants have been too sparse to allow the development of dynamic models to predict changes in the arsenic contents of different tissues following ingestion. A study is described during which a group of 6-month-old lambs were given a single oral administration of 73AsCl3. Subsequently, concentrations of 73As in the tissues of groups of lambs slaughtered at intervals over a period of 181 days were determined. A true absorption coefficient of 0·46±0·055 (mean±S.E.) was determined which is considerably lower than expected from previous studies of non-ruminant animals which demonstrate complete absorption for inorganic arsenic. The resultant data were used to develop a compartment model to describe arsenic behaviour in sheep tissues. The derived model accounted for 80 % (n = 100) of the observed variation in the data. The model predicts that arsenic concentrations in tissues rapidly (< 40 days) reach equilibrium with the dietary intake level. Equilibrium transfer coefficient values (the ratio of the arsenic concentration in a tissue to the daily dietary intake of arsenic) for the important food-chain tissues were calculated as: (2·5±0·67)×10−3 days/kg for muscle, (9·1±1·96)×10−3 days/kg for liver and (1·1±0·14)×10−2 days/kg for kidney.
Phosphorus leaching from liquid digested sewage sludge applied to sandy soils
Authors: SHEPHERD M. A. , WITHERS P. J.
Published: July 2002

The aim of the experiment was to determine the importance of liquid digested sewage sludge (‘sewage sludge’) as a source of phosphorus leaching from sandy soils in the UK. The sewage sludge was applied to uncropped loamy sand and sandy loam monolith lysimeters (1·2 m deep) annually for 3 years. The application rate was sufficient to supply approximately 60 kg P/ha annually. An application equivalent to four times this amount was also applied to two other loamy sand lysimeters to test the effects of excessive amounts. Total P (TP), total dissolved P (TDP) and molybdate-reactive P (MRP) concentrations were measured in the drainage water and were compared with leaching from untreated control soils.

After two sewage sludge applications, Olsen's extractable P content of the topsoil had increased: a P surplus of c. 100 kg/ha was required to raise the topsoil concentration by 5 mg/kg. Sewage sludge applications at the lower rate did not increase P concentrations in the drainage. Phosphorus concentrations were generally small and were, as an average of both soil types and nil and lower rate sludge applications, 12, 20 and 34 μg/l for MRP, TDP and TP respectively. Phosphorus leaching losses from the higher rate (excessively large sewage sludge applications) were more variable but not significantly (P > 0·05) different from the other treatments. Average concentrations were 9, 23 and 50 μg/l for MRP, TDP and TP respectively. Leaching from sludge biosolid applications at operational rates to sandy soils moderately well supplied with P is not a major P loss pathway.
Phosphorus homoeostasis in grazing breeder cattle
Authors: TERNOUTH J. H. , COATES D. B.
Published: July 2002

The phosphorus (P) balances and
32P kinetics of 15 Droughtmaster heifers were studied in mid and
late pregnancy and early and late lactation to compare their P absorption
coefficients and their P
endogenous faecal losses with those of growing cattle. The heifers continuously
grazed three
paddocks of tropical pasture for a year to provide a range of P intakes.

The daily dry matter (DM) and P intakes of the heifers were generally much
higher during lactation
(17–26 g DM/kg LW and 11–40 mg P/kg LW) than during
pregnancy (10–16 g DM/kg LW and
6–22 mg P/kg LW), due in part to the heifers calving at the beginning
of the wet (pasture growing)
season. Plasma inorganic P levels decreased as the experiment progressed and
were very low
(<30 mg/l) in all treatments in late lactation. Milk and milk P secretion
were high in early lactation
(4·0–5·5 l/day and 12–16 mg P/kg LW per day)
so the heifers were in more negative balance during
lactation than during pregnancy.

The coefficient of P absorption was similar to that previously observed in
growing cattle consuming
forage diets and it was concluded that 0·75 was the appropriate value to use
in the estimation of
requirements. Endogenous faecal losses ranged from 7 to 17 mg/kg LW and were
related to P intake
or DM intake plus plasma inorganic P. Comparison of the regressions with those
from the larger data
set for growing cattle showed that the endogenous faecal losses were similar
and there were no special faecal endogenous losses in breeding cattle.
Application of the CERES–Wheat model to yield predictions
in the irrigated plains of the Indian Punjab
Authors: HUNDAL S. S. , PRABHJYOT-KAUR
Published: July 2002

The crop–environment resource synthesis model for wheat,
CERES–Wheat, was used to simulate yields
from 1985 to 1993 at Ludhiana, India. The simulated anthesis and
physiological maturity dates, grain
and total biomass yields of wheat were compared with actual observations
for the commonly grown
cultivar, HD–2329. The simulated and actual dates of phenological
events showed deviations from
only −9 to +6 days for anthesis and −6 to +3 days for
physiological maturity of the crop. The
model estimated the kernel weight within 88–113% (mean 100%) of the
actual kernel weights. The
model predicted the grain yields from 80 to 115% (mean 97·5%)
of the observed grain yield. Biomass
yields were predicted from 93 to 128% (mean 110·5%) of
the observed yields. The results obtained
with the model for the eight crop seasons demonstrated satisfactory
predictions of phenology, growth
and yield of wheat. However, the biomass simulations indicated the
need for further examination of
the factors controlling the partitioning of photosynthates during
crop growth. The results of this
study reveal that the calibrated CERES–Wheat model
can be used for the prediction of wheat growth
and yield in the central irrigated plains of the Indian Punjab.
Towards the explanation of within-field variability of
yield of winter barley: soil series differences
Authors: LARK R. M. , CATT J. A. , STAFFORD J. V.
Published: July 2002

In a trial over three successive seasons, the yields of winter
barley crops were mapped on a 6 ha field,
the soils of which had been mapped according to a system of simple units
corresponding to soil series
as defined by the Soil Survey of England and Wales. Significant yield variation
was explained by
differences between soil map units, and the interaction with differences
between seasons. The physical
properties of the soil series and the potential soil moisture deficits
in the three seasons suggested that
moisture differences between the soils accounted for much of the observed
differences in yield. The
implications of these results for crop management in response to within-field
variability are discussed.
Effects of phosphorus fertilizer sources on cowpea
and subsequent cereal crop productivity in semi-arid
West Africa
Authors: MULEBA N. , COULIBALY M.
Published: July 2002

A natural rock phosphate, ‘Kodjari” (RP), sparingly
soluble, indigenous to Burkina Faso, and a
commercial single superphosphate (SSP) fertilizer were studied at Farako-Bâ in
the Northern Guinea
Savannah (NGS) and at Oipasse in the Sudan Savannah (SS) regions of Burkina
Faso. A 3-year crop
sequence either of cowpea, maize and sorghum or of cowpea, sorghum and
sorghum was used,
respectively, in the NGS and SS regions. The sorghum crop in the third
year was not fertilized with
any phosphorus (P) source. The objectives of the research were to study
the direct and residual effects
of the P fertilizers on soil fertility improvement in order to boost agricultural
productivity in both
regions.

Cowpea daylength-insensitive cultivars, in both regions, and maize and
sorghum in the NGS and
SS regions, respectively, responded more strongly to SSP than to RP fertilizer
treatments. The
optimum rate of SSP and RP source was 21·8 kg P/ha and 43·6
kg P/ha, respectively, for cowpea in
both regions. The optimum rates of phosphorus fertilizer applied in the
second year to maize in the
NGS and to sorghum in the SS region, in addition to the optimum rate of
P applied to cowpea the
previous year, was 10·9 kg P/ha of SSP or 43·6 kg P/ha
of RP, and 21·8 kg P/ha of SSP or
43·6 kg P/ha of RP, respectively. Both P sources had significant
residual effects for up to 2 years. The
agronomic effectiveness of RP relative to SSP, in the year of application
of both fertilizers, was
greater for cowpea than for maize in the NGS region and similar for cowpea
and sorghum in the SS
region; it increased markedly for the two subsequent cereal crops in both
regions. Cowpea
fertilization with both P sources proved, therefore, to be effective in
improving the soil fertility and
boosting the productivity of cereal crops in the 3-year crop sequence.
Characterization and potential role of annual clover
landraces in the farming systems of Mediterranean
areas
Authors: RUSSI L. , FALCINELLI M.
Published: July 2002

The re-introduction of forages into the farming systems of central and southern Italy has been
advocated by EU policies in order to reduce high inputs and favour more sustainable agricultural
systems. Since legumes could certainly play a major role, landraces and natural populations of
Trifolium alexandrinum (2), T. incarnatum (5) and T. squarrosum (3) were investigated. Two
experiments were conducted during the 1991/92, 1992/93 and 1993/94 seasons in Perugia, central
Italy. The objective of the first was to obtain the morphological and physiological characteristics of
the entries, while the second assessed the biomass production, forage quality (stem: leaf: inflorescence
ratio, protein, fibre, O.M. digestibility, milk and meat Forage Units) and seed yields. In T. incarnatum,
flowering time, leaf area, stem length and diameter were important characteristics for discriminating
between populations. Norcia and Rocca di Corno, two natural populations of T. incarnatum,
flowered early, produced the most biomass and had high forage quality. Their potential as
forage/pasture crops and/or cover crops in Mediterranean farming systems is discussed.
C and N mineralization of composted and
anaerobically stored ruminant manure in differently
textured soils
Authors: THOMSEN INGRID K. , OLESEN JØRGEN E.
Published: July 2002

Three animal manures cross-labelled with 15N in either the urine, faeces or straw fractions were
prepared. After a storage period of 86 days when the manures were exposed to either composting or
to anaerobic storage, portions of the manures were incubated in six differently textured soils with clay
contents ranging from 11 to 45%. Evolved CO2-C was determined during a 266 day incubation and
inorganic N and 15N in soil were measured at the termination of the incubation. The mineralization
of C was analysed using first-order kinetics, and two C pools with fast (P1) and slow (P2) turnover
rates were estimated. The total conversion of added C (Ps) was estimated as Ps=P1+P2.

The cumulated CO2 production was considerably higher from soils incubated with anaerobically
stored manure compared with soils amended with composted manure. CO2 production levelled off
after c. 60 days in the three sandier soils whereas CO2 continued to be produced throughout the
incubation from the three soils with the highest clay content. More C was assigned to the easily
decomposable P1 pool in the sandiest soils whereas the more recalcitrant P2 pool was larger in the soils
with higher clay content. Because of the different relationships between soil texture and C pools, Ps
ended up being similar for five of the six soils. When taking C losses during the preceding storage into
account, the accumulated C losses during storage and after incubation in soil accounted for 60 and
54% of C initially present in the composted and anaerobically stored manure, respectively.

Net N mineralization which averaged 16% of applied organic N took place in all soils amended
with composted manure. Soils with anaerobically stored manure showed net immobilization after the
266 days of incubation. The amount of N immobilized accounted for up to 30% of the inorganic N
applied with the manure. As anaerobically stored manure generally loses less inorganic N during
storage, it may contain more inorganic N than composted manure at the time of field application.
Because of the immobilization that takes place after application of anaerobically stored manure to
soil, the immediate levels of plant available N in soil may not be as different from soil supplied with
composted manure as could be expected from the inorganic N content in the two types of manure.
However, when considering the manure as a N resource, anaerobic storage is superior to composting.
THE IMPACT OF MASS MEDIA FAMILY PLANNING PROGRAMMES ON CURRENT USE OF CONTRACEPTION IN URBAN BANGLADESH
Authors: KABIR M. , ISLAM M. AMIRUL
Published: July 2002

A sample of 871 currently married urban Bangladeshi women was used to assess the impact of mass media family planning programmes on current contraceptive use. The analyses suggested that radio had been playing a significant role in spreading family planning messages among eligible clients; 38% of women with access to a radio had heard of family planning messages while the figures for TV and newspaper were 18·5% and 8·5% respectively. Education, number of living children and current contraceptive use were important predictors of exposure to any mass media family planning messages. There was a negative relationship between breast-feeding and the current use of contraception indicating a low need for contraception among women who were breast-feeding.
SEXUAL BEHAVIOUR AND CONTRACEPTION AMONG UNMARRIED ADOLESCENTS AND YOUNG ADULTS IN GREATER ACCRA AND EASTERN REGIONS OF GHANA
Authors: AGYEI WILLIAM K. A. , BIRITWUM RICHARD B. , ASHITEY A. G. , HILL ROBERT B.
Published: July 2002

A fertility survey of unmarried adolescents and young adults (953 males and 829 females) in Greater Accra and Eastern regions of Ghana revealed that a substantial proportion of the respondents were sexually experienced. Overall, 66·8% of the males and 78·4% of the females were sexually experienced. The mean ages (±SD) of the males and females were 15·5±2·5 and 16·2±2·0 years, respectively. Most respondents claimed to have received adequate information on reproductive health and sexually transmitted diseases (STDs), including AIDS. However, 20% and 30% of the respondents in peri-urban and rural areas, respectively, did not know that a girl could get pregnant the first time she has sexual intercourse. The incidence of pregnancy among the unmarried female respondents was relatively high (37%), and was higher in urban than in rural areas. Approximately 47% of those who had ever been pregnant reported that they had had an abortion. Levels of contraceptive awareness were high (98·2% among males and 95·5% among females) but many still engaged in unprotected sexual relations. The most commonly used methods were the condom and the pill. The main reasons given for non-use were that they did not think about contraception, were concerned about the safety of contraceptives, and partner objection. These findings point to the need for targeting of unmarried adolescents and young adults with information on reproductive health and family planning to increase their awareness of the risks of pregnancy, STDs and HIV infection.
Effect of altering the daily herbage allowance
to cows in mid lactation on the composition, ripening and
functionality of low-moisture, part-skim Mozzarella cheese
Authors: GUINEE TIMOTHY P. , MULHOLLAND EDWARD O. , MULLINS CATHERINE , CORCORAN MICHAEL O. , CONNOLLY JAMES F. , BERESFORD THOMAS , MEHRA RAJ , O'BRIEN BERNADETTE J. , MURPHY JOHN J. , STAKELUM GEAROID , HARRINGTON DERMOT
Published: July 2002

Milk was collected from three spring-calving herds,
on different daily
herbage allowances (DHA) of perennial rye-grass (16, 20 or
24 kg dry matter (DM)/cow for a 17 week period. On
five occasions, at weekly intervals in the middle
of the period, the three different milks were converted
into low-moisture part-skim
Mozzarella cheese. Increasing the DHA resulted in significant
increases in the concentrations of protein in the cheesemilk
(P<0·05) and cheese whey
(P<0·02). The moisture-adjusted cheese
yield increased significantly (P<0·01) on
raising the DHA from 16 to 24 kg grass DM/cow. DHA had no
significant effects on any of the
gross compositional values of the cheese (although moisture
and fat-in-DM levels
tended to decrease and increase respectively with increasing
DHA). The hardness of
the uncooked cheese and functionality of cooked cheese
(i.e. melt time, flowability,
stretch and viscosity) were not significantly influenced by
DHA over the 115 d ripening period at 4°C.
Dr M. Elisabeth Sharpe
Authors: Bramley A. J.
Published: July 2002

Dr M. Elisabeth Sharpe, who died last year, was Editor of the Journal of Dairy
Research from 1975 to 1989. During this period she devoted her considerable energies
and talent to putting the Journal on a sound financial footing and expanding its
contributions from authors in the developing world. Becky, as she was known to her
friends and colleagues, was highly successful in both these goals and the Journal
continues to build upon her success to this day.

Her editorship was the culmination of a notable scientific career, full of
achievement and friendships. Born in 1916 in Barnsley, Yorkshire, Becky Sharpe
completed her BSc degree at University College London in 1937 and went on to a
year of postgraduate study in microbiology at the University of Manchester. She
then joined the staff of the National Institute for Research in Dairying, Shinfield, an
Agricultural Research Council Institute and a part of the University of Reading. She
left in 1942 for a 4 year stint with The Boots Company in Nottingham and returned
to Shinfield for a 30 year period of exemplary research in dairy microbiology in the
Department of Bacteriology.

The Department had a tremendous group of researchers and was a really exciting
place for many of us to start our careers working with people like Becky Sharpe,
Bruno Reiter, Frank Neave and Christina Cousins. Becky interacted with many of
us over her career, and her research resulted in hundreds of publications and
contributions to the scientific literature on the microbiology and microflora of milk
and dairy products. She is probably best remembered for her work on staphylococci,
micrococci and the lactobacilli. Often she pioneered the development of new
techniques for the growth, isolation and identification of these Gram-positive
organisms. She was especially pleased with her work as a contributor and editor for
Bergey's Manual of Systematic Bacteriology, which continued after retirement. She
received her PhD from the University of Reading in 1951 and a DSc degree from the
University of London in 1973.

On a more personal note, the author remembers Becky as a generous and
stimulating scientific colleague. She was always willing to listen to the ideas of a
young and inexperienced scientist and offer help and advice. She was highly
respected and well known in the world of dairy microbiology, and many outstanding
microbiologists either worked with her or trained under her. Her laboratory was a
favoured stop for researchers from across the globe.

After retiring from active research in 1976 she remained very active in scientific
circles. Her Editorship of the Journal was a major commitment, but she was also an
active participant in scientific society activities, particularly as a fellow of the
Institute of Biology. Her numerous scientific contributions, and the health and
international flavour of the Journal speak to her professional accomplishments. Her
friendship and help will be fondly remembered and missed by all of those fortunate
enough to have worked with her.
Görtler vortices in compressible mixing layers
Authors: SARKIES J. M. , OTTO S. R.
Published: July 2002

In experiments, Plesniak, Mehta & Johnson (1994) have noted that curved two-stream
mixing layers are susceptible to centrifugal instabilities under the condition that the
slower of the streams curves towards the faster one; this condition is analogous to
the concave curvature condition for the stability of the flow over a plate. The modes
which arise manifest themselves as vortices aligned with the dominant flow direction.
Previous numerical and analytical work has elucidated the structure of these vortices
within incompressible mixing layers; Otto, Jackson & Hu (1996). In this paper we
go on to investigate the rôles of compressibility and heating in determining the
streamwise fate of Görtler vortices within these situations.

The development of the disturbances is monitored downstream and curves of
neutral stability are plotted. The effect of changing the Mach number and free-stream
temperatures is studied in detail. It is found that for certain parameter régimes modes
can occur within convexly curved, or ‘stable’ mixing layers; these ‘thermal modes’
have no counterpart within incompressible mixing layers. By making use of a large
Görtler number analysis we are able to verify our numerical results, and derive a
very simple condition which yields information about the parameter ranges for which
certain modes are likely to occur. As an aside this method can be used to show
that no degree of wall cooling will allow sustained growth of Görtler vortices within
boundary layers over convex plates.
Energy conservation, time-reversal invariance and reciprocity in ducts with flow
Authors: MÖHRING WILLI
Published: July 2002

A sound wave propagating in an inhomogeneous duct consisting of two semi-infinite
uniform ducts with a smooth transition region in between and which carries a steady
flow is considered. The duct walls may be rigid or compliant. For an irrotational
sound wave it is shown that the three properties of the title are closely related, such
that the validity of any two implies the validity of the third. Furthermore it is shown
that the three properties are fulfilled for lossless locally reacting duct walls provided
the impedance varies at most continuously. For piecewise-continuous wall properties
edge conditions are essential. By an analytic continuation argument it is shown that
reciprocity remains true for walls with loss. For rotational flow, energy conservation
theorems have been derived only with the help of additional potential-like variables.
The inter-relation between the three properties remains valid if one considers these
additional variables to be known. If only the basic gasdynamic variables in both half-ducts are known, one cannot formulate an energy conservation equation; however,
reciprocity is fulfilled.
Shock formation in the presence of entropy gradients
Authors: LIN HAO , SZERI ANDREW J.
Published: July 2002

The steepening of a normal compression wave into a shock in a homentropic flow
field is understood well through the method of characteristics. In a non-homentropic
flow field, however, shock formation from a compression wave is more complex. The
effects of entropy (or sound speed) gradients on shock formation from a compression
wave are determined using a wave front expansion in Cartesian and in spherical
polar coordinates. The latter problem has application to the intense energy focusing
of sonoluminescence, particularly when applied to a spherically collapsing gas. The
principal result is an analytical criterion for the time and place of shock formation,
for a wave propagating into a field of smoothly varying entropy.
Statistical mechanical description and modelling of turbulent collision of
inertial particles
Authors: WANG LIAN-PING , WEXLER ANTHONY S. , ZHOU YONG
Published: July 2002

The collision rate of monodisperse solid particles in a turbulent gas is governed by
a wide range of scales of motion in the flow. Recent studies have shown that large-scale energetic eddies are the dominant factor contributing to the relative velocity
between two colliding particles (the turbulent transport effect), whereas small-scale
dissipative eddies can enhance the collision rate significantly by inducing local non-uniform particle distribution (the accumulation effect). The turbulent transport effect
is most noticeable when the particle inertial response time τp is of the order of the
flow integral timescale and the accumulation effect is most pronounced when τp is
comparable to the flow Kolmogorov time.

We study these two contributions separately through direct numerical simulations.
The two effects are quantified carefully with a numerical procedure that is independent
of the computation of average collision rate. This facilitates the study of not only the
statistical description of the collision kernel, but also the relative contributions and
modelling of the two physical effects. Simulations at several flow Reynolds numbers
were performed to suggest a model for the accumulation effect. The data show that
the accumulation effect scales linearly with flow Taylor microscale Reynolds number
Rλ, while the theory for fully developed turbulence indicates that the maximum level
of the turbulent transport effect scales with R1/2λ. Finally, an integrated model has
been developed to predict the collision rate at arbitrary flow Reynolds numbers and
particle inertia.
Baroclinic topographic modons
Authors: REZNIK GREGORY M. , SUTYRIN GEORGI G.
Published: July 2002

The theory of solitary topographic Rossby waves (modons) in a uniformly rotating
two-layer ocean over a constant slope is developed. The modon is described by an
exact, form-preserving, uniformly translating, horizontally localized, nonlinear solution
to the inviscid quasi-geostrophic equations. Baroclinic topographic modons are
found to translate steadily along contours of constant depth in both directions: either
with negative speed (within the range of the phase velocities of linear topographic
waves) or with positive speed (outside the range of the phase velocities of linear
topographic waves). The lack of resonant wave radiation in the first case is due to
the orthogonality of the flow field in the modon exterior to the linear topographic
wave field propagating with the modon translation speed, that is impossible for
barotropic modons. Another important property of a baroclinic topographic modon
is that its integral angular momentum must be zero only in the bottom layer; the
total angular momentum can be non-zero unlike for the beta-plane modons over flat
bottom. This feature allows modon solutions superimposed by intense monopolar
vortices in the surface layer to exist. Explicit analytical solutions for the baroclinic
topographic modons with piecewise linear dependence of the potential vorticity on
the streamfunction are presented and analysed.
Experimental and numerical studies of an eastward jet over topography
Authors: TIAN YUDONG , WEEKS ERIC R. , IDE KAYO , URBACH J. S. , BAROUD CHARLES N. , GHIL MICHAEL , SWINNEY HARRY L.
Published: July 2002

Motivated by the phenomena of blocked and zonal flows in Earth's atmosphere, we
conducted laboratory experiments and numerical simulations to study the dynamics
of an eastward jet flowing over wavenumber-two topography. The laboratory experiments
studied the dynamical behaviour of the flow in a barotropic rotating annulus
as a function of the experimental Rossby and Ekman numbers. Two distinct flow
patterns, resembling blocked and zonal flows in the atmosphere, were observed to
persist for long time intervals.

Earlier model studies had suggested that the atmosphere's normally upstream-
propagating Rossby waves can resonantly lock to the underlying topography, and
that this topographic resonance separates zonal from blocked flows. In the annulus,
the zonal flows did indeed have super-resonant mean zonal velocities, while the
blocked flows appear subresonant. Low-frequency variability, periodic or irregular,
was present in the measured time series of azimuthal velocity in the blocked regime,
with dominant periodicities in the range of 6–25 annulus rotations. Oscillations have
also been detected in zonal states, with smaller amplitude and similar frequency.
In addition, over a large region of parameter space the two flow states exhibited
spontaneous, intermittent transitions from the one to the other.

We numerically simulated the laboratory flow geometry in a quasi-geostrophic
barotropic model over a similar range of parameters. Both flow regimes, blocked
and zonal, were reproduced in the simulations, with similar spatial and temporal
characteristics, including the low-frequency oscillations associated with the blocked
flow. The blocked and zonal flow patterns are present over wide ranges of forcing,
topographic height, and bottom friction. For a significant portion of parameter space,
both model flows are stable. Depending on the initial state, either the blocked or
the zonal flow is obtained and persists indefinitely, showing the existence of multiple
equilibria.
A solution technique for longitudinal Stokes flow around multiple aligned cylinders
Authors: TOLL S.
Published: July 2002

This technique solves the two-dimensional Poisson equations in geometries involving
cylindrical objects. The method uses three fundamental solutions, corresponding to
a line force, a line couple and a pressure gradient, on each cylinder. Superposition
of the fundamental solutions due to all the cylinders involved, while approximately
satisfying the no-slip condition on each cylinder, yields a mobility matrix relating the
various forces and motions of all the cylinders. Any specific problem can be solved
by prescribing the motions of the cylinders and solving the matrix. For problems
involving few cylinders or with a sufficient degree of symmetry this can be done
analytically.

Once constructed, the general method is applied analytically to a series of specific
problems. The permeability of an eccentric annulus is derived. The result is numerically
indistinguishable from the exact solution to the problem, but unlike the exact solution
the present one is obtained in closed form. The drag on two parallel rods moving
past one another is also derived and compared to the exact solution. In this case
the result is accurate for rod separations down to about 0.2 times the rod diameter.
Finally the drag on a rod moving in a triangular array of identical rods is derived.
Here it is shown that due to screening it is sufficient to include the six nearest
neighbours, regardless of the rod separation. Although the present examples are all
worked out analytically, the matrix can also be solved numerically, in which case any
two-dimensional arrangement of cylindrical objects can be studied.
Thermocapillary effects on a thin viscous rivulet draining steadily down a uniformly heated or cooled slowly varying substrate
Authors: HOLLAND D. , DUFFY B. R. , WILSON S. K.
Published: July 2002

We use the lubrication approximation to investigate the steady flow of a thin rivulet
of viscous fluid with prescribed volume flux draining down a planar or slowly varying
substrate that is either uniformly hotter or uniformly colder than the surrounding
atmosphere, when the surface tension of the fluid varies linearly with temperature.
Utilizing the (implicit) solution of the governing ordinary differential equation that
emerges, we undertake a comprehensive asymptotic and numerical analysis of the
flow. In particular it is shown that the variation in surface tension drives a transverse
flow that causes the fluid particles to spiral down the rivulet in helical vortices (which
are absent in the corresponding isothermal problem). We find that a single continuous
rivulet can run from the top to the bottom of a large horizontal circular cylinder
provided that the cylinder is either warmer or significantly cooler than the surrounding
atmosphere, but if it is only slightly cooler then a continuous rivulet is possible only
for a sufficiently small flux (though a rivulet with a discontinuity in the free surface
is possible for larger values of the flux). Moreover, near the top of the cylinder the
rivulet has finite depth but infinite width, whereas near the bottom of the cylinder it
has finite width and infinite depth if the cylinder is heated or slightly cooled, but has
infinite width and finite depth if the cylinder is significantly cooled.