bluuebunny/crossref_metadata_2025_split huggingface dataset:
Method for the measurement of lipase activity in milk
Authors: HUMBERT GERARD , GUINGAMP MARIE-FRANCE , LINDEN GUY 
Published: July 2002

Lipolysis has many effects in dairy technology. Undesirable
consequences include deleterious effects on the organoleptic properties of milk
and some cheeses; however, it is desirable in some other cheeses.The usual methods for detecting lipolysis in milk measure the amounts of free
fatty acids liberated from triacylglycerols (International Dairy Federation, 1991).
Lipase activity is detected by incubation of samples with substrates such as
tributyrin (Castberg et al. 1975) or triolein (Nilsson-Ehle &
Schotz, 1976; Shirai et al.
1982). A few reports describe methods using synthetic chromogenic substrates, e.g.
p-nitrophenyl butyrate (Shirai & Jackson, 1982), β-naphthyl
caprylate (McKellar,
1986; McKellar & Cholette, 1986) or 4-methylumbelliferyl oleate (Stead, 1983).
Tsakalidou et al. (1992) have developed the detection of
esterase activities on electrophoresis gels.
Direct numerical simulation of a three-dimensional spatially developing bubble-laden mixing layer with two-way coupling
Authors: DRUZHININ O. A. , ELGHOBASHI S. E. 
Published: July 2002

Direct numerical simulations (DNS) of a three-dimensional spatially-developing mixing
layer (ML) laden with spherical gaseous bubbles are performed, with both one-way
and two-way coupling between the two phases. Forcing is used to initialize the
spanwise vortex roll-up and to create a pair of counter-rotating streamwise vortices,
rendering the carrier flow three-dimensional. The characteristics of the resulting ML
flow field are similar to those reported in numerous experimental and numerical studies.
The volume fraction (or concentration) of the bubble phase is considered small
enough to neglect bubble–bubble interactions. The no-slip fluid velocity condition
is assumed at the bubble surface, and the bubble Reynolds number is less than 1
throughout the simulation time. The two-fluid formulation (TF) is used to compute
the bubble-phase velocity and concentration and the two-way coupling source term
in the fluid momentum equation. A Lagrangian–Eulerian mapping (LEM) solver is
employed to solve the equations for the bubble velocity and concentration. LEM is
capable of resolving the gradients of concentration created by the bubble preferential
accumulation without numerical instabilities. Two different inflow profiles (Cref(z)) of
bubble-phase concentration are considered: a uniform profile and a tanh-profile. In
the latter case, the high-speed (upper) stream is devoid of bubbles, and the low-speed
(lower) stream is uniformly laden with bubbles at the inflow plane.The DNS results show that in addition to the well-known preferential accumulation
of bubbles in the vortex centres, sheets of increased bubble concentration (C-sheets)
develop in the rollers created by the vortex pairing in the ML core, with two local
maxima of vorticity and an enhanced strain-rate field. The development of C-sheets
is governed by the stretching and contraction along the principal axes of the local
strain rate.In the case of uniform Cref, the two-way coupling reduces the average ML vorticity
thickness and the entrainment of the irrotational fluid into the ML core, as compared
to the bubble-free case, upstream of the location of the first vortex pairing. However,
both ML vorticity thickness is increased and entrainment is enhanced by the bubbles
farther downstream, after the pairing. The fluid velocity fluctuations are reduced by
the bubbles throughout the ML, as compared to the one-way coupling case.In the case of the tanh-profile of Cref, the velocity fluctuations and the ML vorticity
thickness are increased by the bubbles upstream the location of the first vortex pairing
owing to the ‘unstable’ inflow bubble stratification (Druzhinin & Elghobashi 1998).
On the other hand, the velocity fluctuations are reduced by the bubbles, and the ML
vorticity thickness oscillates with the streamwise distance farther downstream.
Scaling and parameterization of stratified homogeneous turbulent shear flow
Authors: SHIH LUCINDA H. , KOSEFF JEFFREY R. , FERZIGER JOEL H. , REHMANN CHRIS R. 
Published: July 2002

Homogeneous sheared stratified turbulence was simulated using a DNS code. The
initial turbulent Reynolds numbers (Re) were 22, 44, and 89, and the initial dimensionless
shear rate (S*) varied from 2 to 16. We found (similarly to Rogers (1986) for
unstratified flows) the final value of S* at high Re to be ∼ 11, independent of initial
S*. The final S* varies at low Re, in agreement with Jacobitz et al. (1997). At low Re,
the stationary Richardson number (Ris) depends on both Re and S*, but at higher
Re, it varies only with Re. A scaling based on the turbulent kinetic energy equation
which suggests this result employs instantaneous rather than initial values of flow
parameters.At high Re the dissipation increases with applied shear, allowing a constant final S*.
The increased dissipation occurs primarily at high wavenumbers due to the stretching
of eddies by stronger shear. For the high-Re stationary flows, the turbulent Froude
number (Frt) is a constant independent of S*. An Frt-based scaling predicts the final
value of S* well over a range of Re. Therefore Frt is a more appropriate parameter for
describing the state of developed stratified turbulence than the gradient Richardson
number.
Flow structures and particle deposition patterns in double-bifurcation airway models.
Part 1. Air flow fields
Authors: COMER J. K. , KLEINSTREUER C. , ZHANG Z. 
Published: July 2002

The understanding and quantitative assessment of air flow fields and local micron-particle wall concentrations in tracheobronchial airways are very important for estimating
the health risks of inhaled particulate pollutants, developing algebraic transfer
functions of global lung deposition models used in dose-response analyses, and/or
determining proper drug-aerosol delivery to target sites in the lung. In this paper (Part
1) the theory, model geometries, and air flow results are provided. In a companion
paper (Part 2, Comer et al. 2001), the history of particle deposition patterns and
comparisons with measured data sets are reported. Decoupling of the naturally dilute
particle suspension makes it feasible to present the results in two parts.Considering a Reynolds number range of 500 [les ] ReD [les ] 2000, it is assumed that
the air flow is steady, incompressible and laminar and that the tubular double bifurcations,
i.e. Weibel's generations G3–G5, are three-dimensional, rigid, and smooth
with rounded as well as sharp carinal ridges for symmetric planar, and just rounded
carinas for 90° non-planar configurations. The employed finite-volume code CFX
(AEA Technology) and its user-enhanced FORTRAN programs were validated with
experimental velocity data points for a single bifurcation. The resulting air flow
structures are analysed for relatively low (ReD = 500) and high
(ReD = 2000) Reynolds
numbers. Sequential pressure drops due to viscous effects were calculated and compared,
extending a method proposed by Pedley et al. (1977). Such detailed results for
bifurcating lung airways are most useful in the development of global algebraic lung
models.
Experimental investigation of the vorticity generation within a

spilling water wave
Authors: DABIRI DANA , GHARIB MORTEZA 
Published: July 2002

Sources of vorticity are examined for a laboratory-generated

spilling breaking wave. Two cases are studied. For the first case,

based on the breaker height, the Reynolds and Froude numbers are 7370

and 2.04, respectively. The breaker is preceded by 1 mm wavelength

capillary waves, with the largest amplitude-to-wavelength ratio equal

to 0.18. For this case, it is found that the dominant source of

vorticity flux is a viscous process, due to the deceleration of a

thin layer of the surface fluid. For the second case, the Reynolds

and Froude numbers based on the wave height are 1050 and 1.62,

respectively. No breaking is observed for this case; rather a

capillary–gravity wave is observed with 4 mm wavelength

capillaries preceding the gravity wave. The largest

amplitude-to-wavelength ratio of these capillaries is 0.28. This case

shows that capillary waves do not contribute to the vorticity flux;

rather the only dominant source of the vorticity flux into the flow

is the free-surface fluid deceleration.Lastly, a thin free-surface jet that is relatively vorticity-free

is found to precede the spilling breaker. Analyses suggest that our

wave-breaking phenomena can be modelled by a hydraulic jump

phenomenon where the Froude number is based on the thickness of the

free-surface jet, and on the velocity of the free-surface jet just

prior to breaking. We believe this to be a more physically

descriptive value of the Froude number. For the high-speed case, the

Froude number based on the thickness of the free-surface jet is 4.78,

while for the lower-speed case it is 2.14.
Scattering of sound waves by a cylindrical vortex: a

semi-analytical theory
Authors: REINSCHKE J. , MÖHRING W. , OBERMEIER F. 
Published: July 2002

A semi-analytical theory for the scattering of plane sound

waves by a compressible, non-homentropic, circular-cylindrical, single

vortex is presented in this paper. As a special case, the scattering

of sound by a cylindrical inhomogeneity (hot spot) is investigated.

Contrary to the otherwise analogous quantum-mechanical scattering

problem, there are singularities in the modified acoustic wave

equation for radii xs ∈ (0, ∞)

when the scattering by a vortex is considered. It will be shown how

these singularities can be treated.This sound-scattering theory is

applied to the problem of the interaction of weak plane shock waves

with a strong cylindrical vortex. The calculated scattered sound

signal has a rather complicated structure in which a cylindrical

wave with an essentially quadrupolar directivity pattern is

discernible. In the case of shock–hot-spot interaction a

scattered sound signal with dipole-like amplitude is obtained. Both

results qualitatively agree with experimental findings.
On the acoustic levitation of droplets
Authors: YARIN A. L. , PFAFFENLEHNER M. , TROPEA C. 
Published: July 2002

This paper deals with the theoretical and experimental

investigation of acoustically

levitated droplets. A method of calculation of the acoustic

radiation pressure based on

the boundary element method (BEM) is presented. It is

applied to predict shapes of

droplets levitated in an acoustic field (and as a result,

deformed by it). The method was

compared with several known exact and approximate analytical

results for rigid

spheres and shown to be accurate (and a widely used

approximate formula for the

acoustic levitation force acting on a rigid sphere was

found to be inaccurate for sound

wavelengths comparable with the sphere radius). The method

was also compared with

some other theoretical approaches known from the literature.Displacement of the droplet centre relative to the pressure

node is accounted for and

shown to be significant. The results for droplet shapes and

displacements are compared

with experimental data, and the agreement is found to be

rather good. Furthermore,

the experimental investigations reveal a unique relationship

between the aspect ratio of

an oblate droplet and the sound pressure level in the

levitator. This relationship agrees

well with the predicted shapes. A practical link between

droplet shape or droplet

displacement and sound pressure level in a levitator is

therefore now available.
Incidence of suicide ideation and attempts in adults: the 13-year follow-up of a community sample in Baltimore, Maryland
Authors: KUO WEN-HUNG , GALLO J. J. , TIEN A. Y. 
Published: July 2002

Background. Utilizing a prospectively designed community sample, we set out to estimate the rate of newly-incident suicidal ideation and attempts (non-fatal suicide behaviour) in a community sample, to evaluate antecedent sociodemographic characteristics and psychiatric disorders, and to assess use of mental health services in relation to non-fatal suicide behaviour.Method. Prospectively-gathered data was utilized from 3481 continuing participants in the 13-year follow-up of the Baltimore sample of the NIMH Epidemiologic Catchment Area survey interviewed in 1981, 1982 and 1993/6.Results. The incidence of suicide attempts was estimated at 148·8 per 100000 person-years and ideation at 419·9 per 100000 person-years. Persons in the youngest age group, in the lowest socio-economic status, and previously married persons were at increased risk for non-fatal suicide behaviour during the follow-up interval. Persons who reported suicidal ideation at baseline were more likely to report having attempted suicide at follow-up (RR = 6·09, 95% CI 2·58–14·36). Psychiatric disorders, especially depression and substance abuse, were associated with new-onset of non-fatal suicidal behaviour. While persons who reported newly-incident suicidal behaviour were more likely to report use of mental health services, few said that suicidal ideation or attempts were the reason for the visits.Conclusions. Suicidal ideation is a common and important antecedent to suicide attempts and deserves more attention in community and general medical settings.
Cognitive impairment in remission in bipolar affective disorder
Authors: RUBINSZTEIN J. S. , MICHAEL A. , PAYKEL E. S. , SAHAKIAN B. J. 
Published: July 2002

Background. Although the traditional view of bipolar affective disorder is that the majority of patients have full remission between episodes, recent evidence suggests that residual cognitive deficits are present. The aim of this study was to determine whether memory and executive deficits were present in a well-defined clinically remitted group of patients.Methods. This was a case–control study of bipolar patients in remission (N = 18). Subjects had to fulfil stringent clinical criteria for inclusion into the study and had to have been in remission for at least 4 months. Subjects also had no history of substance dependence. The cognitive battery examined memory and executive function.Results. Patients in excellent clinical remission and who reported good social adaptation showed impairment on tests of visuospatial recognition memory. Accuracy on four tests of executive function was not impaired in patients in remission compared with controls, although response latency on these executive tests was still impaired.Conclusions. As our group and others have shown, patients with mania and unipolar depression show generalized impairment on tests of memory and executive function. In comparison, this study has demonstrated that patients in remission show a relatively specific impairment in memory with recovery of accuracy measures on executive function task. The increased response latency on the executive tasks suggests a possible small residual impairment. These findings suggest that in neuroanatomical terms, more posterior cortical function (temporal lobe) has not improved but there is at least some recovery of frontal lobe function in remission.
On Why the Best Should Always Meet
Authors: Sandqvist Tor 
Published: July 2002

It seems plausible, even truistic, that when an agent is faced with the choice of giving up one belief or another, the decision should be based on the relative strengths of these beliefs along some dimension of doxastic merit. This said, however, two non-trivial questions arise:(1) Which dimension?(2) How should the contraction outcome be affected by the distribution of beliefs along this dimension?
Forests on a full Earth
Authors: WOODWELL GEORGE M. 
Published: July 2002

Objective: a return to a wholesome human habitatThe continued operation of the biosphere as a wholesome human habitat would be expected to emerge as one of several persistent collective purposes in human affairs. Daly (1993) has pointed to the challenge as accommodating the transition from an empty Earth, where resources exceed demand, to a full Earth, where demand routinely exceeds the resource. Forests are so large in every aspect of the biophysics of the human habitat that their functional integrity is intrinsic to that purpose. How can the functional integrity of forests on a full Earth best be assured on a global basis over the next decades as all pressures on the human habitat continue to soar? Such is the challenge before the World Commission on Forests and Sustainable Development, now completing its final hearings and preparing its report. The Commission was established in 1995 as a non-governmental group of distinguished citizens from the forested countries to do what governments had been unable to do in 1992 at the Rio Conference, namely to address the critical global and international issues of forests in the context of the emergent public interests, as opposed to continued destructive commercial exploitation. The Commission's staff and offices are in Geneva. Its report will be released in 1998.
The Clostridium perfringens enterotoxin from equine isolates;

its characterization, sequence and role in foal diarrhoea
Authors: NETHERWOOD T. , BINNS M. , TOWNSEND H. , WOOD J. L. N. , MUMFORD J. A. , CHANTER N. 
Published: July 2002

During a survey of foal diarrhoea between 1991 and 1994,
Clostridium perfringens was
significantly associated with disease with 56% of cases infected [1].

The contribution of
enterotoxigenic C. perfringens to this association, was assessed
by
use of the reverse passive
latex agglutination test for enterotoxin (RPLA; Oxoid Unipath) and vero
cell toxicity
neutralized by antitoxin on stored faecal samples and sporulated faecal
isolates of C.
perfringens. Polymerase chain reaction (PCR1) based on the DNA sequence
for the whole
enterotoxin gene [2] yielded a fragment from an equine
isolate of the anticipated size which,
cloned into plasmid M13 phage, had a sequence essentially identical to
the published sequence.
Consequently, all faecal isolates were also tested by PCR1 and for a part
of the enterotoxin
gene (PCR2).Significant association with diarrhoea (controls not in contact with
cases) was found with
positive RPLA tests on faeces (OR=13, P=0·002) and isolates

(OR=4·57, P=<0·0001),
vero cell toxicity of isolates (OR=1·78, P=0·026),

and PCR1 (OR=nd, P=0·029) but not
PCR2 or vero cell toxicity of faeces. Significant association with diarrhoea
was also found for
isolates negative by RPLA (OR=3·91; CI 2·05–7·57;

P<0·0001) or PCR1 (OR=4·81; CI
2·84–8·20; P<0·0001). Many of
the isolates from RPLA positive faeces and verotoxic isolates
were PCR negative and no evidence could be found for the presence of the
enterotoxin gene in
a random selection of RPLA positive/PCR negative isolates by gene probe
on chromosomal
DNA and PCR reaction product or vero cell toxicity neutralized by specific
antiserum. Failure
of the vero cell toxicity on faeces to be associated with diarrhoea or

for cytotoxicity of cultures
and RPLA on cultures to agree with the PCRs was believed to be related
to the presence of
other cytotoxins, the inherent cytotoxicity of equine faeces and to the

poor specificity of the commercial antiserum used in the test.Enterotoxigenic C. perfringens could not account for the
overall association of C. perfringens
with foal diarrhoea because (a) cultures positive by PCR, RPLA or cytotoxicity
were not
significantly more common amongst isolates from cases than controls; and
(b) the proportion
of isolates from cases positive by PCR (PCR1 or PCR2) was too small at
9·7%.
Morphometric differentiation between the Italian hare (Lepus corsicanus De Winton, 1898) and the European brown hare (Lepus europaeus Pallas, 1778)
Authors: Riga F. , Trocchi V. , Randi E. , Toso S. 
Published: July 2002

AbstractThe Italian hare (Lepus corsicanus De Winton, 1898), formerly considered a subspecies of the European brown hare (L. europaeus Pallas, 1778), is an endemic species recently revalidated by genetic analyses. We performed univariate and multivariate analyses to assess morphological discrimination between L. corsicanus and L. europaeus. A clear morphological discrimination in body and skull measurements between Italian hares and European hares was evident. Our results are consistent with the morphological observations in the historical specimens and with mtDNA data. Furthermore, no morphological hybrid was found even in areas where viable populations of the two species coexist in sympatry. Despite the original distribution of the Italian hare, it is impossible to determine a clear boundary between the two species because of human introduction of L. europaeus for hunting. Populations of L. corsicanus have been recorded from central Italy to Sicily, with a fragmented distribution and sometimes in sympatry and syntopy with populations of L. europaeus. However, in Sicily the Italian hare is continuously distributed, locally abundant and no stable European hare populations have been found. Although the conservation of the Italian hare needs to be understood better, urgent conservation and management strategies are required to avoid the threat of extinction for local populations.
Early diversification of the avian brain:body relationship
Authors: Nealen Paul M. , Ricklefs Robert E. 
Published: July 2002

AbstractScaling of avian brain:body mass throughout the diversification of the class was investigated by analysis of a large collection of adult brain and body masses. Linear regression model analysis of whole‐class brain:body scaling resulted in scaling exponents ranging from 0.574 to 0.609, values which exclude several prior empirical and theoretical estimates. Taxonomic level‐specific analysis of brain:body scaling was performed by major‐axis regression of trait variances partitioned among levels of taxonomic distinction. Brain:body scaling exponents varied markedly among avian orders, but were not easily related to ecological differences among taxa. Avian brain:body scaling exhibited a partial taxon‐level effect, in that scaling exponents vary with the taxonomic level of investigation. However, scaling exponents were greatest at the family level, a pattern not consistent with prior ontogenetic or genetic covariance models of trait diversification. Instead, it is suggested that initial diversification among birds was largely through body size diversification, while later diversification of families within orders contained a relatively greater degree of brain size diversification. Avian developmental mode, known to influence avian brain size at hatching, was associated with relatively little variance in adult brain mass. Avian brain:body diversification has occurred relatively uniformly in precocial taxa, while diversification within altricial taxa is marked by a relatively high degree of brain mass diversification among families within orders.
The social organization of the kinkajou Potos flavus (Procyonidae)
Authors: Kays Roland W. , Gittleman John L. 
Published: July 2002

AbstractThe social organization of the kinkajou Potos flavus is described from 380 h of observations on habituated, free‐ranging animals. Individuals were most often alone while feeding at night, yet they regularly interacted in stable social groups. Four social groups were observed, each consisting of a single adult female, two adult males, one sub‐adult and one juvenile. At least one breeding female was solitary and did not reside within a group. Social groups were consolidated primarily at denning sites and large fruiting trees by group feeding, allogrooming and scent marking. However, kinkajous were most often observed solitarily, as social feeding only occurred in 19.6 of total feeding bouts (mainly among males) and individuals rarely travelled together. Although the composition of social groups was polyandrous, males also copulated with non‐group females which suggests a promiscuous mating system. Female‐biased dispersal and patterns of male association seem to be patrilineal and based on resource defence. The evolution of social organization in the kinkajou is discussed in relation to predation risk, resource availability, and convergence with primates of similar fission–fusion socioecology.