bluuebunny/crossref_metadata_2025_split huggingface dataset:
The n-alkane concentrations in buds and leaves of browsed broadleaf trees
Authors: PIASENTIER E. , BOVOLENTA S. , MALOSSINI F. 
Published: July 2002

The concentration of n-alkanes in the cuticular wax of plants can be used to estimate the composition
of the diet selected by free-ranging animals. The aims of this study were to characterize the n-alkane
profiles of developing leaves and evaluate the degree of chemical discrimination between six browsed
broadleaf tree species: European ash (Fraxinus excelsior L.), flowering ash (Fraxinus ornus L.),
hornbeam (Carpinus betulus L.), hazel (Corylus avellana L.), mountain ash (Sorbus aucuparia L.) and
beech (Fagus sylvatica L). The effect of the stage of development was examined by considering five
different vegetative stages: dormant bud (DB), late bud (LB), young leaf (YL), mature leaf (ML) and
senescing leaf (SL). Five samples per each vegetative stage and species, gathered in a mixed woodland
of the Italian Eastern Alps between February and October, were analysed for their n-alkane
concentrations (C23–C36).The residual coefficient of variation was 15·5% on average for the individual n-alkanes considered.
There were noticeable differences in individual and total n-alkanes content between species. In
particular, C27 was the predominant n-alkane in beech and C33 was found in high proportions in the
two species of Fraxinus; hazel and flowering ash had a higher total n-alkanes content than the overall
mean, while the lowest values were found in hornbeam and beech. The n-alkane profile also
underwent important changes during the vegetative development, with different extent and direction
according to the species. In the three successive leaf stages, a tendency for a progressive increase in
the longest chain homologues was observed. In any case, the young leaf stage differed most from the
contiguous stages.Canonical discriminant analysis indicated that the n-alkane profile of buds and leaves were
mathematically distinguishable and the chemical differences between species were persistent over the
plant vegetative development.
Climate change: a response surface study of the effects
of CO2 and temperature on the growth of French
beans
Authors: WURR D. C. E. , EDMONDSON R. N. , FELLOWS J. R. 
Published: July 2002

The possible impact of global rises in atmospheric CO2 concentration and temperature on the growth
and development of French beans (Phaseolus vulgaris) was examined using growth cabinets. Five CO2
concentrations of 350, 450, 550, 650 and 750 vpm and five temperatures of 14·5, 15·5, 16·5, 17·5 and
18·5°C were tested using a fractional factorial design comprising nine treatment combinations of the
two factors. Plants were grown under constant irradiance, common atmospheric humidities (vpd
0·5 kPa) and non-limiting supplies of water and mineral nutrients. The plant growth response was
modelled by fitting polynomial response function curves to the times to first flower opening, first bean
set, 50% maturity and the number and yield of beans. The effects of temperature were large and
positive for most of the measured variables, whereas the effects of CO2 were small and negative or
non-existent. Increased temperature substantially reduced the time to flowering and the time from
bean set to 50% maturity and increased the number and yield of mature beans whereas increased CO2
concentration had little effect on plant growth except that bean yield was very slightly reduced. There
was no significant evidence of interaction between the CO2 concentration effects and the temperature
effects.The time to maturity and yield of mature beans was simulated for the 2020s (2010 to 2039) and the
2050s (2040 to 2069) using the fitted polynomial models and four climate change scenarios suggested
by the UK Climate Impacts Programme. These simulations showed that, depending upon the assumed
scenario, the 2020s yields could rise by 39–84% and time to maturity reduce by between 6 and 15 days
whereas the 2050s yields could rise by 51–118% and time to maturity reduce by between 9 and
25 days.
Rumen biohydrogenation of n-3 polyunsaturated fatty
acids and their effects on microbial efficiency and
nutrient digestibility in sheep
Authors: WACHIRA A. M. , SINCLAIR L. A. , WILKINSON R. G. , HALLETT K. , ENSER M. , WOOD J. D. 
Published: July 2002

The study examined the extent to which n-3 PUFA from different sources were biohydrogenated in
the rumen and their effects on rumen microbial efficiency and whole tract nutrient digestibility. Four
ruminally and duodenally cannulated wether lambs were used in a 4×4 Latin square design. Four
iso-energetic and iso-nitrogenous diets based on dried grass were formulated to provide similar fat
levels (60g/kg DM) from different sources; Megalac (palmitic acid: C16:0; Control), whole linseed
(α-linolenic acid, C18:3n-3 ; Linseed) fish oil (eicosapentaenoic acid, C20:5n-3, EPA and
docosahexaenoic acids C22:6n-3, DHA; Fish oil) and whole linseed plus fish oil providing equal
amounts of oil (LinFish). Diets were offered at a rate of 1·2kg/day in 12 equal portions.Total fatty acid intake was similar on all diets whilst duodenal fatty acid flow varied between
101, 94, 87 and 90% of dietary intake for animals fed the Control, Linseed, Fish oil and Linfish diets
respectively. Duodenal flow of C18:3 n-3 in animals fed the Linseed diet was twice that of animals
fed the Control diet (P < 0·01) whilst animals fed the Fish oil diet had a significantly greater flow of
EPA and DHA than those fed any of the other dietary treatments. Duodenal flow of trans C18:1 in
animals fed the Linfish diet was significantly greater than that in animals fed either Linseed, Fish oil
or Control diets (P < 0·001). Biohydrogenation of C18:3n-3 was 80 to 93% in all diets whilst that
of C20:5n-3 and C22:6n-3 was 72 to 79% in diets that contained fish oil or linseed and fish oil.
Apparent fatty acid digestibility (duodenum to rectum) tended to be greater for unsaturated than
saturated fatty acids whilst whole tract fatty acid digestibility (mouth to rectum) was significantly
greater in animals fed diets containing fish oil (P0·05). All dietary n-3 PUFA sources decreased
microbial protein synthesis and efficiency when expressed as either gN/kg organic matter (OM)
apparently or truly degraded in the rumen. Additionally, the inclusion of fish oil increased the
proportion of propionate in the rumen whilst depressing the rumen digestibility of OM and fibre
(P < 0·01), but had no significant effect on whole tract OM or fibre digestibility.
Involvement of a pasteurizer in the contamination of milk by Bacillus cereus in a commercial dairy plant
Authors: SVENSSON BIRGITTA , ENEROTH ÅSA , BRENDEHAUG JOHANNE , MOLIN GÖRAN , CHRISTIANSSON ANDERS 
Published: July 2002

Bacillus cereus is a common contaminant in raw milk. The spores survive
pasteurization and psychrotrophic strains of B. cereus often limit the keeping quality
of pasteurized milk stored at > 6 °C (Griffiths, 1992). High numbers of B. cereus in
pasteurized milk are most frequent when the cows are grazing (Slaghuis et al. 1997),
mainly owing to increased levels of spores in raw milk resulting from teat
contamination by soil (Christiansson et al. 1999). However, high numbers can also be
found in pasteurized milk while the cows are housed indoors, and this is probably
caused by additional contamination at the dairy plant (te Giffel et al. 1996; Larsen &
Jørgensen, 1997; Lin et al. 1998). There is little information available about the
sites of recontamination in the dairy. The use of typing techniques capable of
discrimination below the species level, such as fatty acid profiles and random
amplification of polymorphic DNA–polymerase chain reaction (RAPD–PCR), could
be helpful in demonstrating contamination routes (Lin et al. 1998; Nilsson et al.
1998).Spores of B. cereus are very hydrophobic and readily adhere to surfaces of steel,
glass and rubber (Rönner et al. 1990), and short cleaning-in-place programmes do not
always eliminate all the spores (Rönner & Husmark, 1992). Spores adhering to
surfaces are more difficult to eliminate by disinfectants than spores in solution (te
Giffel et al. 1995). Many B. cereus spores germinate rapidly in milk upon heat
activation and, if allowed to propagate undisturbed on surfaces, may form biofilms
that are extremely difficult to eliminate (Mosteller & Bishop, 1993; Wirtanen et al.
1996; Kumar & Anand, 1998).This paper describes how we demonstrated the involvement of a pasteurizer in
the contamination of pasteurized milk by B. cereus in a commercial dairy plant using
a combination of classic microbiological analyses and typing of strains by
RAPD–PCR.
Mineral content of camel milk and colostrum
Authors: GORBAN ALI M. S. , IZZELDIN OMAR M. 
Published: July 2002

The camel population of Saudi Arabia is ∼607000 out
of a world population of
17 million. All are dromedaries (Camelus dromedarius) of
four major ecotypes (Elamin & Wilcox, 1992), giving daily milk yields of
3·5–35·0 kg/animal (Knoess,
1977). Camel milk is low in lactose compared with cows' milk
(Elamin & Wilcox,
1992). However, levels of potassium, magnesium, iron, copper, manganese, sodium
and zinc are higher than in cows' milk (Sawaya et al. 1984;
Abu-Lehia, 1987). Farah
(1993) found low levels of potassium and phosphorus in Egyptian dromedaries. There
is little difference between the milk of dromedaries and that of bactrian camels
(Kheraskov, 1961).In the Gulf region and some southern Mediterranean countries, substantial
amounts of camel milk are consumed by the local people. The investigation reported
here was undertaken to shed more light on the nutritional contribution made by
camel milk.
Inertial nonlinear equilibration of equatorial flows
Authors: HUA BACH LIEN , MOORE DENNIS W. , GENTIL SYLVIE LE 
Published: July 2002

We explore the nature of inertial equilibration of equatorial
flows in the presence of mean meridional and vertical shears of the
basic state, with oceanic applications in mind. The study is
motivated by the observational evidence that the subthermocline
equatorial mean circulation displays nearly zero Ertel potential
vorticity away from the equator, when taking into account the
non-traditional horizontal component of the Earth rotation. This
observed state precisely verifies the marginal condition for inertial
instability: a linear analysis for the equatorial β-plane
confirms that the usual condition of instability, namely that Ertel
potential vorticity should be of opposite sign to the vertical
Coriolis parameter, remains valid even when the traditional
approximation is relaxed. Analytical linear normal modes reveal that
a meridional shear of the basic state leads to a vertical stacking of
equatorially-trapped zonal flows of alternate signs, with a new
centre of symmetry located at the dynamical equator. A vertical shear
of the basic state causes a meridional stacking of extra-equatorial
zonal flows.In an inviscid framework, a two-dimensional formulation is
ill-posed and we resort to non-hydrostatic viscous simulations to
determine the nonlinear normal forms of the system. The influence of
a small-scale eddy diffusivity and a large-scale Rayleigh damping on
the equilibrated vertical scale is determined numerically. The
nonlinear equilibration occurs through a steady-state bifurcation
from a basic state without jets to another steady state with
secondary jets of alternate signs. The final state corresponds to
eastward jets located on the geographic equator, while westward jets
are located near the dynamical equator. These results are consistent
with in situ observations of equatorial deep jets.The analogy between the equatorial meridional shear flow and the
cylindrical Couette–Taylor flow with an axial density
stratification is detailed. There is a strong similarity in the
general symmetries and nonlinear normal forms of the two problems.
Similarly to the homogeneous Couette–Taylor flow, the gap width
between the two cylinders is important for determining the axial
scale of the secondary flow through the Reynolds number. For the
equatorial problem, an upper bound for the height scale of inertial
jets is such that the corresponding equatorial radius of deformation
times √2 fits between the geographic and dynamic equators.One of our main conclusions is that the raisond’être of the observed region of zero
Ertel potential vorticity is to facilitate angular momentum exchanges
between the two hemispheres and inertial deep jets are the byproducts
of this angular momentum mixing.
Laboratory study of the interaction between

two internal wave rays
Authors: TEOH S. G. , IVEY G. N. , IMBERGER J. 
Published: July 2002

Laboratory experiments were conducted to study the interaction
between two

downward propagating internal wave rays with identical properties but opposite

horizontal phase velocities. The intersection of the rays produced a velocity

field with

stagnation points, and these points propagated vertically upwards within
the

intersection region. Nonlinear non-resonant interactions between the two
rays

produced evanescent modes, with frequencies greater than the ambient buoyancy

frequency, trapped within the intersection region. These evanescent modes
provided a

mechanism whereby energy could accumulate locally and, even though the
vertical

wavelength of the primary resultant wave remained the same, the local isopycnal

displacements increased in time. Eventually, the isopycnals were forced
to

overturn in the region just above the stagnation points by the variation
with

depth in the local horizontal strain rate.The gravitationally unstable overturning ultimately broke down releasing
its

available potential energy and generating turbulence within the intersection
region.

The results showed that the release of available potential energy was disrupted
by

the wave motions and even the dissipative scales were directly affected
by the

ambient stratification and the background wave motion. The distribution
of the

centred displacement scales was highly skewed towards the Kolmogorov scale
and the

turbulent Reynolds number Ret was low. Thus,
the net

buoyancy flux was very small

and almost all turbulent kinetic energy was dissipated over the parameter
range

investigated. The results also showed that for such dissipative events
the

square of the strain Froude number

(ε/νN20)

and the turbulent Reynolds number Ret can
be less than

one.
Numerical simulation of the evolution of

Tollmien–Schlichting waves over finite compliant panels
Authors: DAVIES CHRISTOPHER , CARPENTER PETER W. 
Published: July 2002

The evolution of two-dimensional Tollmien–Schlichting waves
propagating

along a

wall shear layer as it passes over a compliant panel of finite length is

investigated by

means of numerical simulation. It is shown that the interaction of such
waves with

the edges of the panel can lead to complex patterns of behaviour. The behaviour

of the Tollmien–Schlichting waves in this situation, particularly
the effect

on their

growth rate, is pertinent to the practical application of compliant walls
for

the delay

of laminar–turbulent transition. If compliant panels could be made

sufficiently short

whilst retaining the capability to stabilize Tollmien–Schlichting
waves,

there is a good

prospect that multiple-panel compliant walls could be used to maintain
laminar flow

at indefinitely high Reynolds numbers.We consider a model problem whereby a section of a plane channel is
replaced

with a compliant panel. A growing Tollmien–Schlichting wave is then

introduced into

the plane, rigid-walled, channel flow upstream of the compliant panel.
The results

obtained are very encouraging from the viewpoint of laminar-flow control.
They

indicate that compliant panels as short as a single Tollmien–Schlichting

wavelength

can have a strong stabilizing effect. In some cases the passage of the

Tollmien–Schlichting wave over the panel edges leads to the excitation
of

stable flow-induced

surface waves. The presence of these additional waves does not appear to
be

associated

with any adverse effect on the stability of the Tollmien–Schlichting
waves.

Except very

near the panel edges the panel response and flow perturbation can be represented
by

a superposition of the Tollmien–Schlichting wave and two other eigenmodes

of the

coupled Orr–Sommerfeld/compliant-wall eigensystem.The numerical scheme employed for the simulations is derived from a
novel

vorticity–velocity formulation of the linearized Navier–Stokes

equations and uses

a mixed finite-difference/spectral spatial discretization. This approach

facilitated the

development of a highly efficient solution procedure. Problems with numerical

stability were overcome by combining the inertias of the compliant wall
and fluid

when imposing the boundary conditions. This allowed the interactively coupled

fluid and wall motions to be computed without any prior restriction on
the form

taken by the disturbances.
Dynamics of a vortex ring moving

perpendicularly to the axis of a rotating fluid
Authors: EISENGA A. H. M. , VERZICCO R. , VAN HEIJST G. J. F. 
Published: July 2002

The dynamics of a vortex ring moving orthogonally to the

rotation vector of a uniformly rotating fluid is analysed by

laboratory experiments and numerical simulations.

In the rotating system the vortex ring describes a curved trajectory,

turning in the

opposite sense to the system's anti-clockwise rotation. This

behaviour has been explained by using the analogy with the motion of

a sphere in a rotating fluid for which

Proudman (1916) computed the forces acting on the body surface.

Measurements

have revealed that the angular velocity of the vortex ring in its

curved trajectory is

opposite to the background rotation rate, so that the vortex has a

fixed orientation in

an inertial frame of reference and that the curvature increases

proportionally to the rotation rate.The dynamics of the vorticity of the vortex ring is affected

by the background

rotation in such a way that the part of the vortex core in

clockwise rotation shrinks

while the anti-clockwise-rotating core part widens. By this

opposite forcing on either

side of the vortex core Kelvin waves are excited, travelling along

the toroidal axis

of the vortex ring, with a net mass flow which is responsible for

the accumulation

of passive scalars on the anti-clockwise-rotating core part. In

addition, the curved

motion of the vortex ring modifies its self-induced strain field,

resulting in stripping

of vorticity filaments at the front of the vortex ring from the

anti-clockwise-rotating

core part and at the rear from the core part in clockwise rotation.

Vortex lines, being

deflected by the main vortex ring due to induction of relative

vorticity, are stretched

by the local straining field and form a horizontally extending

vortex pair behind

the vortex ring. This vortex pair propagates by its self-induced

motion towards the

clockwise-rotating side of the vortex ring and thus contributes to

the deformation of

the ring core. The deflection of vortex lines from the main vortex

ring persists during

the whole motion and is responsible for the gradual erosion of

the coherent toroidal structure of the initial vortex ring.
Planetary waves in a stratified ocean of variable
depth. Part 2. Continuously stratified ocean
Authors: BOBROVICH A. V. , REZNIK G. M. 
Published: July 2002

Linear Rossby waves in a continuously stratified ocean over a corrugated rough-bottomed topography are investigated by asymptotic methods. The main results are
obtained for the case of constant buoyancy frequency. In this case there exist three
types of modes: a topographic mode, a barotropic mode, and a countable set of
baroclinic modes. The properties of these modes depend on the type of mode, the
relative height δ of the bottom bumps, the wave scale
L, the topography scale Lb and
the Rossby scale Li. For small δ
the barotropic and baroclinic modes are transformed
into the ‘usual’ Rossby modes in an ocean of constant depth and the topographic
mode degenerates. With increasing δ the frequencies of the barotropic and topographic
modes increase monotonically and these modes become close to a purely topographic
mode for sufficiently large δ. As for the baroclinic modes, their frequencies do not
exceed O(βL) for any δ. For large δ the
so-called ‘displacement’ effect occurs when
the mode velocity becomes small in a near-bottom layer and the baroclinic mode does
not ‘feel’ the actual rough bottom relief. At the same time, for some special values
of the parameters a sort of resonance arises under which the large- and small-scale
components of the baroclinic mode intensify strongly near the bottom.As in the two-layer model, a so-called ‘screening’ effect takes place here. It implies
that for Lb<Li
the small-scale component of the mode is confined to a near-bottom
boundary layer (Lb/Li)H
thick, whereas in the region above the layer the scale L of
motion is always larger than or of the order of Li.
Sex and depression
Authors: BEBBINGTON PAUL E. 
Published: July 2002

Sex differences in rates of depressive disorder have not been

convincingly explained, and this reflects

a more general failure of research to provide a comprehensive

aetiological account of depression.

The difference can be used as a probe for evaluating the research

base of integrative models of

depressive disorder (e.g. Akiskal & McKinney, 1975). It is

particularly likely to be illuminating if

the causes of the sex difference do not overlap completely the

causes of depression itself. While there

have been many reviews in the area (Weissman & Klerman, 1977;

Kessler & McRae, 1981; Wolk

& Weissman, 1995; Bebbington, 1996), this point has not been

adequately expressed.Several lines of investigation are necessary for assessing the

relative importance of social,

psychological and biological influences: the epidemiological study

of macrosocial variables and of

age effects; temperament, personality, and attributional and coping

styles; the experience of

psychosocial adversity; and the possibility of increased susceptibility

to some forms of stress in

women. Both the tendency to affiliation and the requirement for

social support may differ by sex.

The particular strains of the roles available to women may increase

their risk of depression. Possible

genetic explanations of the sex difference are of special relevance

because of their implications for

biological differences. The latter can also be studied directly:

hormonal theories in particular must be evaluated.