bluuebunny/crossref_metadata_2025 huggingface dataset:
Physically-based segmentation of the Western Carpathians (Central Europe)
Authors: Bandura Peter , Minár Jozef , Drăguţ Lucian
Published: August 2018

Results of a physically-based methodology to delineate morphometrical-morphostructural subdivision of the Western Carpathian region (Central Europe) from DEMs and their derivatives are presented. Previous suitability evaluation of an object-oriented methodology showed its potential in recognition of morphostructural features. In this study we moved towards a more complex object-oriented approach – fusion of segmentation and classification on several hierarchical levels. In addition, physicallybased geomorphometric variables were used as input data, resulting in enhancement of subsequent morphotectonic interpretations. Decrease of local variance of the delineated objects in comparison with simple segmentations without these upgrades confirms the efficiency of our approach.
Using Sentinel-1 SAR data to detect earth surface changes related to neotectonics in the Focșani basin (Eastern Romania)
Authors: Necula Nicusor , Niculita Mihai , Floris Mario
Published: August 2018

Ground deformations are the result of interactions between terrain and various processes. Their identification and monitoring becomes an important step as they can provide insights about Earth’s dynamics or process triggering conditions. This paper aims to show the potential use of Sentinel-1 SAR images to identify ground deformations induced by neotectonics. Hence, we applied PS-InSAR stacking technique on Sentinel-1 ascending dataset in the area of Focșani basin, Eastern Romania. High density of PS obtained in populated areas allows the detection of tectonic fractures. They are characterized by blocks movement in opposite direction with 5-10 mm/year. Detection of geologic lineaments using free Sentinel-1 data presents a great advantage for future geological surveys which permits a better delineation of tectonic accidents, especially where seismic data are not available.
Scientific research in Neotropical protected areas: themes and gaps
Authors: Teixeira Elizabeth C , Santos Jayne S , Silva Maxwell R G , Malhado Ana CM , Ladle Richard J , Batista Vandick S
Published: August 2018

Protected areas are often used by scientists to observe natural processes and organisms in habitats that have been minimally influenced by human actions. In contrast to many PA objectives, their effectiveness for promoting and supporting scientific research can be easily quantified in terms of quantity and quality of scientific products (primarily peer-reviewed articles) that are based on research within a PA’s boundaries. In addition to their contribution to global scientific knowledge, these research products may support local conservation efforts and contribute to park management, monitoring and governance. Here, we investigate the effectiveness of Neotropical PAs at supporting scientific research based on data from the World Database of Protected Areas (WDPA). Specifically, we randomly selected 102 PAs from each designation from the Latin American and Caribbean region, to give a total of 612 PAs. A total of 444 PAS did not return any results and only 30 were associated with more than 10 publications. Research topics varied widely in the PAs in our dedicated sample, but we found an evident trend to research related to geosciences and paleontology. Conservation and biodiversity were secondary subjects. there seems to be a lack of influence of PAs type and presence of management plan on scientific productivity. On the other hand, we have seen that most areas do not present a management plan, the absence of which makes it more difficult to assess the effectiveness of these areas.
Policy Implementation Analysis on Exclusive Breastfeeding in Working Area of Cicalengka Community Health Center in Bandung Regency West Java
Authors: Mardhatillah Innana , Ilyas Yaslis
Published: August 2018

Data and information on the health profile of Indonesia in 2016 showed only 29.5% of infants receive exclusive breastfeeding until 6 months, the low level of exclusive breastfeeding made the government issue a regulation on exclusive breastfeeding in Government Regulation Number 33 of 2012. The study aimed to analyze the policy implementation of exclusive breastfeeding at Cicalengka Community Health Center. The study used qualitative analysis with in-depth interview method, focus group discussion and literature study. The result of this study shows that breastfeeding policy implementation in health centers is not optimal, as seen from the low coverage of exclusive breastfeeding. Socialization of the policy has not been done as a whole, the time and task division is unclear and has no special budget and the standard operating procedures is not really used in carrying out the policy. Communication is the most influential factor in the implementation of the policy. There is no support and commitment from all employees in the implementation of exclusive breastfeeding policy. The suggestion is to consistently socialize to employees and the public, carry out supervision in an effort to secure the policy, run the Standard Operating Procedure (SOP), allocate budget activities in 2018, create a memorandum of understanding with other agencies, and Self-assessment and program evaluation absolutely must do continuously.
Capturing change in clonal composition amongst single mouse germinal centers
Authors: Firl Daniel J , Degn Soren E , Padera Timothy , Carroll Michael C
Published: August 2018

Understanding cellular processes occurring in vivo on time scales of days to weeks requires repeatedly interrogating the same tissue without perturbing homeostasis. We describe a novel setup for longitudinal intravital imaging of murine peripheral lymph nodes (LNs). The formation and evolution of single germinal centers (GCs) was visualized over days to weeks. Naïve B cells encounter antigen and form primary foci, which subsequently seed GCs. These experience widely varying rates of homogenizing selection, even within closely confined spatial proximity. The fluidity of GCs is greater than previously observed with large shifts in clonality over short time scales; and loss of GCs is a rare, observable event. The observation of contemporaneous, congruent shifts in clonal composition between GCs within the same animal suggests inter-GC trafficking of memory B cells. This tool refines approaches to resolving immune dynamics in peripheral LNs with high temporospatial resolution and minimal perturbation of homeostasis.
THE PERFORMANCE OF CULTIVARS OF PEARL MILLET AND CLUSTERBEAN UNDER SOLE CROPPING AND INTERCROPPING SYSTEMS IN ARID ZONE CONDITIONS IN INDIA
Authors: YADAV R. S. , YADAV O. P.
Published: July 2002

Intercropping of pearl millet (Pennisetum glaucum) with clusterbean (Cyamopsis tetragonoloba) is a common practice in the arid zone of northwestern India. Field experiments were conducted for two years to examine the performance of two contrasting genotypes of each of these crops grown both as sole crops and as intercrops using all possible genotypic combinations of the pearl millet with the clusterbean. The seed yields of both crops were always lower in intercropping than in sole cropping, though the degree of reduction in the seed yield of each intercrop component was influenced greatly by the genotype of its companion crop. The seed yield of both clusterbean genotypes was reduced more when intercropped with the tall and late-maturing pearl millet, MH 179, than with the medium-statured and early-maturing HHB 67. On the other hand, the two clusterbean cultivars had similar effects on intercropped pearl millet. As a result, the highest land equivalent ratios (LERs) were obtained with intercrops containing pearl millet HHB 67 rather than MH 179, while the genotype of clusterbean had little overall effect on LER. The results obtained are discussed in the context of developing cultivars for intercropping.
ADOPTION POTENTIAL OF HEDGEROW INTERCROPPING IN MAIZE-BASED CROPPING SYSTEMS IN THE HIGHLANDS OF WESTERN KENYA 2. ECONOMIC AND FARMERS' EVALUATION
Authors: SWINKELS R. , FRANZEL S.
Published: July 2002

Hedgerow intercropping is evaluated both economically and from the farmers' viewpoint, based on four years of experience of 45 farmers in western Kenya. Farmers were able to establish and prune the hedges; however, both activities considerably increased labour use during the busiest period of the year. Women did not generally prune the hedges. The average extra maize yield required each year, beginning in the second year, to cover the added cost of hedgerow intercropping was 10.5% (s.d. 5.5) when based on returns to land and 17.5% (s.d. 6.5) based on returns to labour. Although about half the farmers claimed that hedges improved crop yields, after three years of experimentation only about one-fifth planted additional hedges and only 14% did so to improve soil fertility. It thus appears that the potential for its adoption as a soil fertility practice in this area is low. Control plots were of little use as farmers were more interested in contrasting test-plot yields with past yields than comparing the test and control plots. Different types of trials may be required to obtain reliable biophysical data on yield response and socio-economic data on farmer assessment of complex agroforestry technologies.
Joint regulation of cell size and cell number in the wing
blade of Drosophila melanogaster
Authors: McCABE JENNIE , FRENCH VERNON , PARTRIDGE LINDA
Published: July 2002

We used Drosophila melanogaster to test for compensatory
control of cell area and cell number in
the regulation of total wing area. In two random bred wild-type base stocks
collected from
different geographic locations we found a negative association between the
area and the number of
cells in the wing blade. Three replicate lines were selected for increased
or decreased wing area,
with cell area maintained at the same level as in the three controls. After
eight generations of
selection, despite a large and highly significant difference in wing area
between the large, control
and small selection lines, cell area did not differ significantly between
them. Rather, the difference
in wing area between selection regimes was attributable to differences in
cell number. Over the
course of selection, the initially significant negative correlation between
cell area and cell number
in the wing increased, providing evidence for compensatory regulation of
cell area and cell
number. As a result of the increasingly negative association between
the two traits, the variance in
wing area declined as selection proceeded. It will be important to
discover the mechanisms
underlying the compensatory regulation of cell area and cell number.
Paternal bottlenecks in fragmented populations of the
grassland daisy Rutidosis leptorrhynchoides
Authors: YOUNG ANDREW G. , BROWN ANTHONY H. D.
Published: July 2002

Allozyme markers were used to estimate mating system parameters
in nine fragmented populations
of the grassland daisy Rutidosis leptorrhynchoides that differed
in size and spatial isolation.
Multilocus estimates of outcrossing rate did not differ significantly among
populations, all
indicating a high level of outcrossing (tm=0·84–1·0).
Small populations showed greater divergence
than large populations between the allele frequencies in the population
and those in the pollen
pool, indicating paternal bottlenecks. Isolated populations of fewer than
200 individuals also
exhibited higher correlations of outcrossed paternity (rp)
than larger populations, indicating the
production of more full-sibs within families. The combination of paternal
bottlenecks and
correlated paternity increases the genetic identity of progeny across families
and predisposes
populations to biparental inbreeding in subsequent generations. As over
half the remaining
populations of R. leptorrhynchoides contain fewer than 200 plants,
such second-order inbreeding
may threaten the viability of the species if it is associated with significant
inbreeding depression.
THE FASCIST CHALLENGE DISSECTED
Authors: MALLETT ROBERT
Published: July 2002

Common destiny: dictatorship, foreign policy, and war in fascist Italy and Nazi Germany. By MacGregor Knox. Cambridge: Cambridge University Press, 2000. Pp. xiv+262. ISBN 0-521-58208-3. £19.95.

Hitler's Italian allies: royal armed forces, fascist regime, and the war of 1940–1943. By MacGregor Knox. Cambridge: Cambridge University Press, 2000. Pp. xiv+207. ISBN 0-521-79047-6. £16.95.
Effect of in vitro manipulation of pH on magnesium
solubility in ruminal and caecal digesta in sheep
Authors: DALLEY D. E. , ISHERWOOD P. , SYKES A. R. , ROBSON A. B.
Published: July 2002

Rumen and caecal digesta were collected, under anaesthetic, from

eight sheep offered either hay,
pelleted concentrate or pasture at the Johnston Memorial Laboratory,
Lincoln University during
1991. Subsamples of digesta were incubated at 39°C for 1 h after adjustment

of pH within the range
0·5–12 by the addition of H2SO4 or
NaOH. The samples were centrifuged at 30000 g for 30 min and
magnesium (Mg) concentration measured in the 30000 g supernatant

fraction and in total digesta to
assess Mg solubility. In rumen digesta, Mg solubility declined from
0·86 at pH 5 to 0·30 at pH 7 and
differences in response between diets were small. Magnesium solubility

in caecal digesta was generally
higher than in ruminal digesta, and particularly at pH values >6.
At pH 7 the difference was twofold.
Moreover, differences were observed between diets in the rate of
decline in solubility in caecal digesta
with increasing pH. At pH 5, 0·90 of Mg from hay and
concentrate diets was soluble compared with
only 0·8 for pasture. At pH 7, Mg solubility in caecal
digesta from hay and concentrate-fed animals
was almost double that from pasture-fed animals (0·64 and
0·62 v. 0·36, respectively). The implications
of the findings for Mg homoeostasis in ruminants are discussed.
Phosphorus fertilizer for nitrogen fertilized dairy

pastures. 1. Long term effects on pasture, diet and soil
Authors: DAVISON T. M. , ORR W. N. , SILVER B. A. , WALKER R. G. , DUNCALFE F.
Published: July 2002

The phosphorus fertilizer requirements and long term productivity
of

nitrogen-fertilized Gatton

panic (Panicum maximum cv. Gatton) pastures, grazed by lactating

dairy cows, were evaluated over

7 years. Cows grazed at 2·6 cows/ha on pastures that received

annually 100 or 300 kg N/ha at each

of 0, 22·5 or 45 kg P/ha. Phosphorus treatments were applied

as single superphosphate, balanced for calcium by applications of gypsum.

The soil had an initial available soil phosphorus content of

40 mg/kg (bicarbonate extraction). At

zero P fertilizer (0P), extractable soil P declined at the rate of

1·9 mg/kg each year; at 22·5P it was

maintained close to the original level while at 45P it increased at

6·6 mg/kg each year. Increased P

fertilizer caused significant (P<0·01) increases

in plant P concentration from year 2 onwards. In

years 6 and 7 there was significantly less green pasture and leaf on

offer in 300N pastures at 0P than

with 22·5P and 45P. There was no influence of rate of P fertilizer

at 100N on pasture quantity on offer

in any year. There were clear trends at 100N of decreasing total pasture

and green dry matter (DM) on offer over the 7 years, but not at 300N.

Cows at 300N consumed more leaf in the diet in autumn and winter

than at 100N. Leaf was

55–60% of the diet in summer and autumn, but decreased to 21%

(100N) and 37% (300N) in winter.

Dead material in the diet was always higher at 100N. Pasture leaf percentage

and leaf yield were the

best individual predictors of leaf percentage in the diet. Diet P selected

from pasture was reduced by

the higher rate of N fertilizer in each season. Estimated P concentrations

of the diet selected from

pasture for summer, autumn and winter averaged 0·30, 0·38
and

0·28% DM for 100N and 0·19, 0·24

and 0·18% DM for 300N treatments, respectively.

The response to P fertilizer was dependent on the rate of N fertilizer

applied. The critical

bicarbonate extractable soil P level for this soil type, below which

pasture responses occurred, was

30 mg/kg at 300N. The critical level at 100N was not reached, but

was <23 mg/kg P.
Phosphorus fertilizer for nitrogen fertilized dairy

pastures. 2. Long term effects on milk production and

a model of phosphorus flow
Authors: DAVISON T. M. , ORR W. N. , DOOGAN V. , MOODY P.
Published: July 2002

The phosphorus fertilizer requirements and long term productivity
of

nitrogen-fertilized Gatton

panic (Panicum maximum cv. Gatton) pastures, grazed by lactating
dairy

cows, were evaluated in a

7-year experiment. Cows grazed at 2·6 cows/ha on

pastures that received annually 100 or

300 kg N/ha and each of 0, 22·5 or 45 kg P/ha.

Cows received no energy supplements in years 1–3

and were offered molasses at 3·5 kg/day from

year 4 to year 7. Cows grazed their experimental

paddocks from the start of the wet season until they started to lose weight

in the dry season.

In years 6 and 7 there was significantly less green pasture

and leaf on offer in 300N pastures at 0P

than with 22·5P and 45P. This was reflected in a reduced milk

yield by cows at 300N/0P in these two

years. There was no influence of rate of P fertilizer

at 100N on milk yield in any year. Lactation milk

yields at 300N in years 6 and 7 averaged 3930, 4310 and 4610 kg/cow

(P<0·05) for 0P, 22·5P and

45P, respectively. Nitrogen fertilizer increased milk yield in each year

(P<0·01) except the first. Milk

yields at 100N and 300N averaged 2860 and 3320 kg/cow

respectively in years 1–3 and 3720 and

4290 kg/cow in years 4–7.

The milk yield responses to P fertilizer were related to the greater

amounts of pasture and green

leaf on offer, which led to a higher proportion of leaf in the diet, and

the response to P fertilizer was

dependent on the rate of N fertilizer applied. Phosphorus intakes were

estimated to be below that of

published requirements for cows producing this quantity of milk. An annual

model of P flow between

plant, animal and soil pools demonstrated that at 100N/22·5P

more P was returned to the soil as

excreta (15·7 kg P/ha) than with 300N/22·5P

(7·1 kg P/ha). The major pathway of return of P to the

soil at 300N was through plant litter. Soil organic P was the largest,

but least exploited, pool of phosphorus.

This study has illustrated how the demand for phosphorus by the plant

in grazed pastures is

modified by the input of N fertilizer, is poorly predicted from plant

analysis and published standards

for animal requirements, and indicates that a response in milk production

may be mediated through

the effects of P on leaf growth and not on dietary P content.
Efficacy of Chinaberry tree (Meliaceae) aqueous
extracts and certain insecticides against the pea
leafminer (Diptera: Agromyzidae)
Authors: ABOU-FAKHR HAMMAD E. M. , NEMER N. M. , KAWAR N. S.
Published: July 2002

Aqueous extracts of fruits and leaves of the Chinaberry tree, Melia azedarach L. were tested for their
efficacy versus other biotic and synthetic insecticides against the pea leafminer, Liriomyza huidobrensis
(Blanchard). The study included field experiments on naturally infested swiss chard, Beta vulgaris var.
Cicla L., and greenhouse experiments on artificially infested cucumber, Cucumis sativus L. that were
conducted in 1995–96. The other treatments included azadirachtin (0·25%), ultrafine mineral oil,
abamectin, cyromazine, imidacloprid, pyrazophos and control. Results of field experiments indicated
that Melia fruit extract and the other insecticides significantly lowered the number of larvae per swiss
chard plant as compared to the control, at 5 days sampling after second spray or 15 days after first
spray, when two consecutive sprays were performed. However, at 10 days after second spray, the fruit
extract did not differ significantly from the control, but it was comparable in its effect to the
insecticides, except abamectin and cyromazine. In greenhouse experiments, the pea leafminer larvae
were found at higher densities on cucumber leaves located at the lower plant part (10–60 cm)
compared to other leaf positions. The Melia fruit extract and the other pesticides significantly
decreased the number of live larvae per cucumber leaf compared to the control, 10 days after each
spray. The fruit extract, abamectin, cyromazine, imidacloprid and pyrazophos lowered the leafminer
population significantly compared to the control, throughout the period of the experiments.
However, the fruit extract was significantly less effective than these insecticides at the final count, 20
days after second spray. Abamectin and cyromazine consistently showed a significant decrease in
number of larvae, in both field and greenhouse experiments. At certain periods of the experiments,
Melia extracts were comparable in their efficacy to the tested commercial biorational and synthetic
pesticides. Thus, they have a good potential to be used in the management of the pea leafminer. This
is the first report for use of M. azedarach against L. huidobrensis.
STARTING, SPACING AND STOPPING IN THE REPRODUCTIVE HISTORIES OF OUTER HEBRIDEAN FAMILIES
Authors: CLEGG E.
Published: July 2002

Maternal ages at the first maternity (starting), at the last maternity (stopping) and the lengths of intervals between maternities (spacing) have been studied in the Outer Hebridean islands of Harris and Barra for births between the years of 1855 and 1990, a period during which a considerable ‘fertility transition’ occurred. There was a tendency in each island for increases with time in the ages at starting among less-fecund women (although after 1936 starting ages declined), and highly significant heterogeneity of covariance: adjusted means dependent on the total numbers of maternities experienced. The same result was seen for the ages at stopping. Lengths of reproductive life (the difference between ages at starting and stopping) rose to 1876–1895, and then fell, apart from a short-lived rise in Barra during 1956–1975, possibly due to the papal encyclical Humanae Vitae. Intervals between marriage and first maternity and between successive maternities were studied by hazard function survival analysis. The marriage–first birth interval remained very constant, unaffected by total maternities. The father’s occupation and the mother’s age at first maternity showed no significant relationships. In Barra there was a weak negative relationship with the date of the marriage. For intervals between maternities in both islands, total maternities and the death of a previous infant were associated with shorter, and birth order with longer intervals. In Harris, there were tendencies for intervals to be consistently long or short in families, and for the age of the mother and date at first maternity to be negatively related to the length of the interval. In Barra, a previous multiple birth was followed by a longer interval. The date of the previous maternity, father’s occupation, maternal age at the previous maternity, the sex of the previous child, and the duration of the marriage appeared to have no influence on maternity intervals. Evidence for an effect of economic deprivation during the 19th century on the variables considered was equivocal. During the 20th century, it is suggested that economic depression during the inter-war years, the spread of contraception, and improvements in health care may have acted ‘synergistically’ toproduce the lower ages of childbearing and the shortening of maternity intervals and reproductive lives.
BIRTH INTERVAL AND THE SEX OF CHILDREN IN A TRADITIONAL AFRICAN POPULATION: AN EVOLUTIONARY ANALYSIS
Authors: MACE RUTH , SEAR REBECCA
Published: July 2002

Birth interval is a major determinant of rates of fertility, and is also a measure of parental investment in a child. In this paper the length of the birth interval in a traditional African population is analysed by sex of children. Birth intervals after the birth of a boy were significantly longer than after the birth of a girl, indicating higher parental investment in boys. However, in women of high parity, this differential disappeared. Birth intervals for women with no son were shorter than for those with at least one son. All these results are compatible with an evolutionary analysis of reproductive decision-making. First born sons have particularly high reproductive success, daughters have average reproductive success and late born sons have low reproductive success. The birth interval follows a similar trend, suggesting that longer birth intervals represent higher maternal investment in children of high reproductive potential.
Effect of temperature and/or pressure on lactoperoxidase activity in bovine milk and acid whey
Authors: LUDIKHUYZE LINDA R. , CLAEYS WENDIE L. , HENDRICKX MARC E.
Published: July 2002

At atmospheric pressure, inactivation of lactoperoxidase (LPO) in milk and whey was studied in a temperature range of 69–73 °C and followed first order kinetics. Temperature dependence of the first order inactivation rate constants could be accurately described by the Arrhenius equation, with an activation energy of 635·3±70·7 kJ/mol for raw bovine milk and 736·9±40·9 kJ/mol for diluted whey, indicating a very high temperature sensitivity. On the other hand, LPO is very pressure resistant and not or only slightly affected by treatment at pressure up to 700 MPa combined with temperatures between 20 and 65 °C. Both for thermal and pressure treatment, stability of LPO was higher in milk than in diluted whey. Besides, a very pronounced antagonistic effect between high temperature and pressure was observed, i.e. at 73 °C, a temperature where thermal inactivation at atmospheric pressure occurs rapidly, application of pressure up to 700 MPa exerted a protective effect. At atmospheric pressure, LPO in diluted whey was optimally active at a temperature of about 50 °C. At all temperatures studied (20–60 °C), LPO remained active during pressure treatment up to 300 MPa, although the activity was significantly reduced at pressures higher than 100 MPa. The optimal temperature was found to shift to lower values (30–40 °C) with increasing pressure.
Determination of free fatty acids in cheese: comparison of two
analytical methods
Authors: CHAVARRI FELISA , VIRTO MAILO , MARTIN CELIA , NÁJERA ANA I. , SANTISTEBAN ARANTZA , BARRÓN LUIS J. R. , DE RENOBALES MERTXE
Published: July 2002

Two methods were compared for the determination of free fatty acids
(FFA) from acetic to long-chain acids in samples with a large excess of
triacylglycerols (TG) (1[ratio ]200, w/w), such as cheese and other
dairy products. In
method 1, after fat extraction, FFA were separated from TG by aminopropyl-bonded
phase chromatography, injecting the fraction containing FFA directly into
the gas chromatograph. In method 2, extracted fat was treated with
tetramethylammonium hydroxide, the methyl ester derivatives being formed in the
injector. Cheese samples and standard mixtures of FFA and TG in different
proportions were analysed by both methods. The cheese sample contained 2·4
times more FFA when analysed by method 2 as compared with the result obtained with
method 1. The composition of the standard mixtures analysed by method 1 closely
reflected that of the original mixture and gave 90–100% recovery of FFA,
regardless
of their chain length and the ratio of FFA[ratio ]TG (1[ratio ]1 or 1[ratio ]200,
w/w). The composition
of samples with a FFA[ratio ]TG ratio of 1[ratio ]200 (w/v) was severely
distorted (as compared
with the original composition of the sample) when analysed by method 2. Varying
recoveries of FFA were also obtained, the largest differences being found for the
shorter-chain components. We conclude that the FFA fraction should be separated
from the TG fraction before derivatization and chromatographic analysis,
particularly for samples in which the FFA represent a minor fraction of the TG.
Microfiltration (0·1 μm) of milk: effect of protein size
and charge
Authors: LE BERRE OLIVIER , DAUFIN GEORGES
Published: July 2002

Microfiltration (MF) of milk with a ceramic membrane (0·1
μm mean pore
diam.) for the separation of casein micelles from soluble proteins was
studied.
Experiments were performed at constant flux density (J=65 or
75 l h−1 m−2) and
wall shear stress (τw=100 or 110 Pa) with milks containing
particles and solutes
with different sizes and charges, produced by physicochemical change (heat
and
mechanical treatment, pH, ionic strength, addition of ions). Membrane separation

performance was limited by the build up of a cake with characteristics
that depended
on the size of particles and soluble proteins. Best performance (higher
permeability
and whey protein transmission) was obtained with milk containing fat on
the one
hand and calcium phosphate on the other. An optimal value of the particle
size was
found, close to 0·5–3·0 μm; above this separation

performance decreased. In
addition, the present study confirmed that the transfer of charged solutes
is the
consequence of both size and ionic exclusion. Better performance was achieved
with
higher ionic strength (1 M).
Contribution of the lactoperoxidase system to the keeping quality
of
pasteurized milk
Authors: BARRETT NICHOLETTE E. , GRANDISON ALISTAIR S. , LEWIS MICHAEL J.
Published: July 2002

The lactoperoxidase system is a naturally occurring antimicrobial
system
found in milk, with lactoperoxidase, thiocyanate and hydrogen peroxide
as its
components. The keeping quality of milk pasteurized at 72°C for 15
s was found to
be better than that of milk heated at 80°C for 15 s. This agrees with
previous findings
and is usually attributed to heat shocking of spores. However, complete
deactivation
of lactoperoxidase occurred at 80°C–15 s, whereas at 72°C–15
s residual lactoperoxidase
activity was ∼70%, which may provide an alternative explanation.
Higher levels of hypothiocyanite (the major antimicrobial agent produced
by the
lactoperoxidase system) were also detected in milk processed at 72 than
at 80°C,
which supports the theory that the lactoperoxidase system has a role in
the keeping
quality of pasteurized milk. Of all the methods evaluated, titratable acidity
and
alcohol stability gave the most consistent estimates of keeping quality,
while
dissolved oxygen was a good indication of the onset of spoilage. Lactoperoxidase
activity decreased with temperature more rapidly between 70 and 80°C
than is usual
for an enzyme over a 10 deg C range.
In vitro digestion of caseinophosphopeptide–iron complex
Authors: AÎT-OUKHATAR NABIL , BOUHALLAB SAÏD , BUREAU FRANÇOIS , ARHAN PIERRE , MAUBOIS JEAN-LOUIS , BOUGLÉ DOMINIQUE L.
Published: July 2002

Caseins bind strongly to Fe by their phosphoseryl residues (Hegenauer et al. 1979;
Brulé & Fauquant, 1982; Bouhallab et al. 1991; Emery, 1992) and keep it soluble at
the alkaline pH of the duodenum (Manson & Annan, 1971; Bouhallab et al. 1991). It
has been suggested that this strong binding prevents the release of free Fe during
digestion and impairs its absorption (West, 1986; Hurrell, 1997), but in human
studies hydrolysis by digestive enzymes to give low molecular mass peptides
improves Fe absorption (Hurrell et al. 1988, 1989).

β-Casein peptide 1–25 (β-CN(1–25)) is the phosphorylated N-terminal fragment
of β-CN. Its molecular mass is 3124 Da and it contains four phosphoseryl residues
that bind four Fe atoms and keep them soluble (Bouhallab et al. 1991).

Preliminary results showed that binding Fe to β-CN(1–25) enhances its
bioavailability in the rat (Aît-Oukhatar et al. 1997) and its absorption by the
duodenal rat loop model (Pérès et al. 1997). We recently showed that the β-
CN(1–25)–Fe complex is hydrolysed to a lesser extent than free β-CN(1–25) during
duodenal digestion, and that the phosphorylated region of the peptide to which Fe
is bound, β-CN(15–24), cannot be detected in the digestive lumen (our unpublished
results).

These previous studies did not examine the effect of luminal digestion that could
release free inorganic Fe. We considered the possibility that Fe bound to β-CN(1–25)
is not released in the digestive lumen, and that it reaches the absorbing surface of the
small intestine brush border membrane as a complex. To test this hypothesis we
examined in vitro the influence of pH and digestive enzymes on the dialysability of
the β-CN(1–25)–Fe complex.
Leading-edge receptivity of a hypersonic boundary layer on a flat plate
Authors: MASLOV A. A. , SHIPLYUK A. N. , SIDORENKO A. A. , ARNAL D.
Published: July 2002

Experimental investigations of the boundary layer receptivity, on the sharp leading edge
of a at plate, to acoustic waves induced by two-dimensional and three-
dimensional perturbers, have been performed for a free-stream Mach number M∞ = 5.92.
The fields of controlled free-stream disturbances were studied. It was shown that
two-dimensional and three-dimensional perturbers radiate acoustic waves and that
these perturbers present a set of harmonic motionless sources and moving sources
with constant amplitude. The disturbances excited in the boundary layer were measured.
It was found that acoustic waves impinging on the leading edge generate
Tollmien–Schlichting waves in the boundary layer. The receptivity coefficients were
obtained for several radiation conditions and intensities. It was shown that there is a
dependence of receptivity coefficients on the wave inclination angles.
A unified approach for symmetries in plane parallel turbulent shear flows
Authors: OBERLACK MARTIN
Published: July 2002

A new theoretical approach for turbulent flows based on Lie-group analysis is presented.
It unifies a large set of ‘solutions’ for the mean velocity of stationary parallel
turbulent shear flows. These results are not solutions in the classical sense but instead
are defined by the maximum number of possible symmetries, only restricted
by the flow geometry and other external constraints. The approach is derived from
the Reynolds-averaged Navier–Stokes equations, the fluctuation equations, and the
velocity product equations, which are the dyad product of the velocity fluctuations
with the equations for the velocity fluctuations. The results include the logarithmic
law of the wall, an algebraic law, the viscous sublayer, the linear region in the centre
of a Couette flow and in the centre of a rotating channel flow, and a new exponential
mean velocity profile not previously reported that is found in the mid-wake region
of high Reynolds number flat-plate boundary layers. The algebraic scaling law is
confirmed in both the centre and the near-wall regions in both experimental and
DNS data of turbulent channel flows. In the case of the logarithmic law of the wall,
the scaling with the distance from the wall arises as a result of the analysis and has
not been assumed in the derivation. All solutions are consistent with the similarity
of the velocity product equations to arbitrary order. A method to derive the mean
velocity profiles directly from the two-point correlation equations is shown.
Drop formation behaviour of a hydrate-forming liquid in a water stream
Authors: KATO MASAHIRO , IIDA TOMOYUKI , MORI YASUHIKO H.
Published: July 2002

Experiments were carried out to investigate the drop formation behaviour of a
hydrophobic hydrate-forming liquid, HCFC-141b (CH3CCl2F), at a single nozzle
in a water stream under hydrate-formable thermodynamic conditions. Attention
was focused on the relation between the clathrate-hydrate formation and the drop
formation. It was observed that two discrete hydrate crusts grow along the liquid–liquid
interface; one forms a frontal cap and the other forms a cylindrical root on
each growing drop before its detachment from the nozzle. Most of the latter crust
remains at the tip of the nozzle after the detachment of the drop so that it grows into
a bell-shaped or nearly cylindrical funnel composed of hydrate deposits in the course
of successive growth/detachment of drops. The size of these drops is dependent
on the instantaneous diameter of the hydrate-funnel tip rather than the diameter
of the nozzle itself. Thus, the size of the drops successively released into the water
stream generally varies synchronously with quasi-periodical alternation of growth and
breaking of the hydrate funnels. The growth and breaking of the hydrate funnels and
the resultant drop-size variation are significantly dependent on the system temperature
(or the system subcooling from the liquid/liquid/hydrate equilibrium temperature),
the nozzle diameter, and the velocity of the drop-forming liquid through the nozzle.
Turbulent mixing in a sloping benthic boundary layer energized by internal waves
Authors: IVEY G. N. , WINTERS K. B. , DE SILVA I. P. D.
Published: July 2002

A laboratory study was carried out to directly measure the turbulence properties
in a benthic boundary layer (BBL) above a uniformly sloping bottom where the
BBL is energized by internal waves. The ambient fluid was continuously stratified
and the steadily forced incoming wave field consisted of a confined beam, restricting
the turbulent activity to a finite region along the bottom slope. Measurements of
dissipation showed some variation over the wave phase, but cycle-averaged values
indicated that the dissipation was nearly constant with height within the BBL.
Dissipation levels were up to three orders of magnitude larger than background
laminar values and the thickness of the BBL could be defined in terms of the
observed dissipation variation with height. Assuming that most of the incoming wave
energy was dissipated within the BBL, predicted levels of dissipation were in good
agreement with the observations.

Measurements were also made of density and two orthogonal components of the
velocity fluctuations at discrete heights above the bottom. Cospectral estimates of
density and velocity fluctuations showed that the major contributions to both the
vertical density flux and the momentum flux resulted from frequencies near the
wave forcing frequency, rather than super-buoyancy frequencies, suggesting a strong
nonlinear interaction between the incident and reflected waves close to the bottom.
Within the turbulent BBL, time-averaged density fluxes were significant and negative
near the wave frequencies but negligible at frequencies greater than the buoyancy
frequency N. While dissipation rates were high compared to background laminar
values, they were low compared to the value of
εtr ≈ 15vN2, the transition value
often used to assess the capacity of a stratified flow to produce mixing. Existing
models relating mixing to dissipation rate rely on the existence of a positive-definite
density flux at frequencies greater than N as a signature of fluid mixing and therefore
cannot apply to these experiments. We therefore introduce a simple model, based
on the concept of diascalar fluxes, to interpret the mixing in the stratified fluid in
the BBL and suggest that this may have wider application than to the particular
configuration studied here.
Nonlinear self-sustained structures and fronts in spatially developing wake flows
Authors: PIER BENOÎT , HUERRE PATRICK
Published: July 2002

A family of slowly spatially developing wakes with variable pressure gradient is
numerically demonstrated to sustain a synchronized finite-amplitude vortex street
tuned at a well-defined frequency. This oscillating state is shown to be described
by a steep global mode exhibiting a sharp Dee–Langer-type front at the streamwise
station of marginal absolute instability. The front acts as a wavemaker which sends
out nonlinear travelling waves in the downstream direction, the global frequency
being imposed by the real absolute frequency prevailing at the front station. The
nonlinear travelling waves are determined to be governed by the local nonlinear
dispersion relation resulting from a temporal evolution problem on a local wake profile
considered as parallel. Although the vortex street is fully nonlinear, its frequency is
dictated by a purely linear marginal absolute instability criterion applied to the local
linear dispersion relation.
Boundary layer leading-edge receptivity to sound at incidence angles
Authors: ERTURK ERCAN , CORKE THOMAS C.
Published: July 2002

The leading-edge receptivity to acoustic waves of two-dimensional parabolic bodies
was investigated using a spatial solution of the Navier–Stokes equations in vorticity/streamfunction
form in parabolic coordinates. The free stream is composed of a
uniform flow with a superposed periodic velocity fluctuation of small amplitude. The
method follows that of Haddad & Corke (1998) in which the solution for the basic
flow and linearized perturbation flow are solved separately. We primarily investigated
the effect of frequency and angle of incidence (−180° [les ] α2 [les ] 180°) of the acoustic
waves on the leading-edge receptivity. The results at α2 = 0° were found to be in
quantitative agreement with those of Haddad & Corke (1998), and substantiated the
Strouhal number scaling based on the nose radius. The results with sound waves at
angles of incidence agreed qualitatively with the analysis of Hammerton & Kerschen
(1996). These included a maximum receptivity at α2 = 90°, and an asymmetric variation
in the receptivity with sound incidence angle, with minima at angles which were
slightly less than α2 = 0° and α2 = 180°.
Joint probability density analysis of the structure
and dynamics of the vorticity field of a turbulent boundary layer
Authors: ONG LAWRENCE , WALLACE JAMES M.
Published: July 2002

An experimental study of a turbulent boundary layer at
Rθ≈1070 and Rτ≈543
was
conducted. Detailed measurements of the velocity vector and the velocity
gradient
tensor within the near-wall region were performed at various distances
from the
wall, ranging from approximately y+=14 to
y+=89. The measured mean statistical
properties of the fluctuating velocity and vorticity components agree well
with previous
experimental and numerically simulated data. These boundary layer measurements

were used in a joint probability density analysis of the various component
vorticity
and vorticity–velocity gradient products that appear in the instantaneous
vorticity
and enstrophy transport equations. The vorticity filaments that contribute
most to
the vorticity covariance Ω[bar]xΩ [bar]y

in this region were found to be oriented downstream
with angles of inclination to the wall, when projected on the streamwise

(x, y)-plane,
that decrease with distance moving from the buffer to the logarithmic layer.
When
projected on the planview (x, z)- and cross-stream
(y, z)-planes, the vorticity filaments
that most contribute to the vorticity covariances
Ω [bar]xΩ [bar]z and
Ω [bar]yΩ [bar]z have angles of

inclination to the z-ordinate axis that increase with
distance from it. All the elements of the
ΩiΩj
∂Ui/∂xj

term in the enstrophy transport equation, i.e. the term that
describes the rate of increase or decrease of the enstrophy by vorticity
filament
stretching or compression by the strain-rate field, have been examined.
On balance,
the average stretching of the vorticity filaments is greater than compression
at all
y+ locations examined here. However, some
individual velocity gradient components
compress the vorticity filaments, on average, more than they stretch them.
Analyses of slow high-concentration flows of granular materials
Authors: SAVAGE S. B.
Published: July 2002

A theory intended for slow, dense flows of cohesionless granular
materials is developed
for the case of planar deformations. By considering granular flows on very
fine
scales, one can conveniently split the individual particle velocities into
fluctuating and
mean transport components, and employ the notion of granular temperature
that
plays a central role in rapid granular flows. On somewhat larger scales,
one can think
of analogous fluctuations in strain rates. Both kinds of fluctuations are
utilized in the
present paper. Following the standard continuum approach, the conservation
equations
for mass, momentum and particle translational fluctuation energy are presented.

The latter two equations involve constitutive coefficients, whose determination
is one
of the main concerns of the present paper. We begin with an associated
flow rule for
the case of a compressible, frictional, plastic continuum. The functional
dependence
of the flow rule is chosen so that the limiting behaviours of the resulting
constitutive
relations are consistent with the results of the kinetic theories developed
for rapid
flow regimes. Following Hibler (1977) and assuming that there are fluctuations
in the
strain rates that have, for example, a Gaussian distribution function,
it is possible
to obtain a relationship between the mean stress and the mean strain rate.
It turns
out, perhaps surprisingly, that this relationship has a viscous-like character.
For low
shear rates, the constitutive behaviour is similar to that of a liquid
in the sense that
the effective viscosity decreases with increasing granular temperature,
whereas for
rapid granular flows, the viscosity increases with increasing granular
temperature as
in a gas. The rate of energy dissipation can be determined in a manner
similar to
that used to derive the viscosity coefficients. After assuming that the
magnitude of
the strain-rate fluctuations can be related to the granular temperature,
we obtain
a closed system of equations that can be used to solve boundary value problems.

The theory is used to consider the case of a simple shear flow. The resulting
expressions
for the stress components are similar to models previously proposed on
a
more ad hoc basis in which quasi-static stress contributions were
directly patched to
rate-dependent stresses. The problem of slow granular flow in rough-walled
vertical
chutes is then considered and the velocity, concentration and granular
temperature
profiles are determined. Thin boundary layers next to the vertical sidewalls
arise with
the concentration boundary layer being thicker than the velocity boundary
layer.
This kind of behaviour is observed in both laboratory experiments and in
granular
dynamics simulations of vertical chute flows.
Direct simulation of the sedimentation of elliptic particles in Oldroyd-B
fluids
Authors: HUANG P. Y. , HU H. H. , JOSEPH D. D.
Published: July 2002

Cross-stream migration and stable orientations of elliptic particles
falling in an
Oldroyd-B fluid in a channel are studied. We show that the normal component
of the
extra stress on a rigid body vanishes; lateral forces and torques are determined
by the
pressure. Inertia turns the long side of the ellipse across the stream
and elasticity turns
it along the stream; tilted off-centre falling is unstable. There are two
critical numbers:
the elasticity and Mach numbers. When the elasticity number is smaller
than critical
the fluid is essentially Newtonian with broadside-on falling at the centreline
of the
channel. For larger elasticity numbers the settling turns the long side
of the particle
along the stream in the channel centre for all velocities below a critical
one, identified
with a critical Mach number of order one. For larger Mach numbers the ellipse
flips
into broadside-on falling again. The critical numbers are functions of
the channel
blockage ratio, the particle aspect ratio and the retardation/relaxation
time ratio of the
fluid. Two ellipses falling near to each other, attract, line-up vertically
and straighten-out with long sides vertical. Stable, off-centre tilting is found for ellipses
falling in
shear-thinning fluids and for cylinders with flat ends in which particles
tend to align
their longest diameter with gravity.
Long interfacial waves in multilayer
thin films and coupled Kuramoto–Sivashinsky equations
Authors: KLIAKHANDLER IGOR L.
Published: July 2002

The coupled Kuramoto–Sivashinsky (CKS) equations for multilayer downflowing
films are derived and explored. The CKS equations exhibit a wealth of dynamical
behaviour, displaying travelling periodic waves, regular and chaotic-like patterns,
coexistence of different attractors, and perfect and imperfect synchronization of the
interfaces. New physical effects are found, such as suppression of the Rayleigh–Taylor
instability for heavy-top stratified films, and new surface-tension-driven instability.