bluuebunny/crossref_metadata_2025 huggingface dataset:
‘Juglers or Schollers?’: negotiating the role of a
mathematical practitioner
Authors: HILL KATHERINE
Published: July 2002

Until the first quarter of the seventeenth century there
was a great deal of agreement about
the nature of mathematical practice. Mathematicians, as well as their patrons
and clients,
viewed all possible aspects of their work, both theoretical and practical,
as being included
within their discipline. Although the mathematical sciences were a fairly
recent foreign
import to England, which can barely be traced back beyond the mid-sixteenth
century, by
the beginning of the seventeenth century there was a large and growing
body of
practitioners with a unified view of their subject's identity. Divisions
began to appear,
however, and they were often framed in terms of the proper mixture of theory
and practice
in mathematical education.

One early sign of the emergence of this tension is the kind of accusation
made in the
priority dispute between William Oughtred and Richard Delamain taking place
around
1632. Their bitter conflict began over who first invented the Horizontal
Quadrant, a form
of sundial, and the Circles of Proportion, a logarithmic calculating device
that can be
considered a precursor of the slide rule, and ended in a dispute over what
constituted
proper mathematical practice. Oughtred accused Delamain of making his students
‘only
doers of tricks, and as it were Juglers’ by teaching them
the use of instruments without any
theoretical foundation. Instruments, Oughtred claimed, could only be used
with
understanding by students who had a proper theoretical foundation. He advocated

postponing their use until after the theoretical foundations of a subject
had been
thoroughly mastered. Delamain, on the other hand, was perfectly willing
to teach practical
instrumental operations without insisting upon a theoretical grounding.
This paper will
use the dispute between Oughtred and Delamain to investigate the breakdown
of
consensus over internal mathematical boundaries, the rhetoric and strategies
involved in
attempts to gain authority by mathematical practitioners, and the extent
to which their
roles were negotiated, both with other practitioners, and with their patrons
and students.
Political Talk Over Here, Over There, Over Time
Authors: BENNETT STEPHEN E. , FLICKINGER RICHARD S. , RHINE STACI L.
Published: July 2002

Data from Great Britain and the United States from the late 1950s to the early 1990s show
relatively little change in the frequency with which citizens engage in political discussions, with
whom they are likely to speak, and the variables that shape their propensity to engage in political
talk. In addition, analyses of the data show that discussing politics enhances citizens' knowledge
of public affairs, even net of other variables known to affect political knowledge. Students of
political behaviour and those interested in strengthening democracy need to treat political
discussions as an important form of political participation.
Review Article: Biopolitics After Three Decades – A Balance Sheet
Authors: SOMIT ALBERT , PETERSON STEVEN A.
Published: July 2002

THE NATURE OF THE UNDERSTANDING

As many political scientists know, ‘biopolitics’ is the short-hand term used to describe the approach of those in the profession who believe that biological concepts — especially evolutionary theory, which treats behaviour as the product of both nature and nurture — and biological research techniques can help us study and understand political behaviour better.
PHENOTYPIC AND YIELD RESPONSES OF IRRIGATED GROUNDNUT CULTIVARS IN A HOT ENVIRONMENT
Authors: ISHAG HASSAN M.
Published: July 2002

High temperature is a major problem in groundnut (Arachis hypogaea) producing areas of arid and semi-arid tropics whether rainfed or irrigated. Knowledge of the maximum air temperature that plants can tolerate will help in selecting genotypes adapted to high temperature. The objectives of this study were to evaluate the growth, development, yield and yield components of different groundnut genotypes grown under elevated temperatures. Five groundnut cultivars and lines were grown in the field from 1984 to 1986 in Vertisols. Measurements on flowering, growth and development were carried out frequently. Thermal units required for groundnut cultivars to reach maturity were 2247 °C days. Larger kernel size, higher pod:total growth ratio and longer pod-filling period were the most important parameters for yield increase in heat-stressed environments. Early Bunch gave a stable yield across environments and was found to be more tolerant of high temperature. Cultivars differed in their pod:total growth ratio and Early Bunch had the highest ratio.
ON-FARM EXPERIMENTS ON INTEGRATED NUTRIENT MANAGEMENT IN RICE-WHEAT CROPPING SYSTEMS
Authors: YADAV R. L.
Published: July 2002

On-farm experiments were conducted between 1990–91 and 1996–97 in the Indian districts of Jalandhar (Punjab) and Ghazipur (Uttar Pradesh), on rice-wheat cropping systems. The aim was to compare yields and net returns from three treatments: (i) farmers' nutrient management practices; (ii) integrated use of organic manures and fertilizer; and (iii) NPK fertilizer inputs alone. Productivity of the rice-wheat systems, in terms of grain yield per unit area, was greater in Jalandhar district than in Ghazipur district. In Jalandhar, a high productivity zone, greatest yields were achieved with integrated use of green manure and fertilizer NPK inputs, while in Ghazipur, a low productivity zone, yields were highest with inputs of fertilizer NPK alone. Increases in yield due to these improved practices, over farmers' practice, were 6.98% in Jalandhar and 46.6% in Ghazipur. At both locations, net returns were greater with the use of fertilizer NPK alone. However, benefits from NPK alone over farmers' practice were 6.96% in Jalandhar and 79.6% in Ghazipur. After 11 years of a long-term experiment, at Ludhiana (Punjab) and Faizabad (Uttar Pradesh) soil organic-C and available phosphorus contents have increased, and available potassium content decreased compared with the initial levels.
REHABILITATION OF DEGRADED GRASSLANDS IN NORTH SYRIA: THE USE OF AWASSI SHEEP TO DISPERSE THE SEEDS OF ANNUAL PASTURE LEGUMES
Authors: GHASSALI F. , OSMAN A. E. , COCKS P. S.
Published: July 2002

Four experiments were conducted to facilitate the improvement of degraded grasslands in north Syria. The first examined the survival of legume seeds fed to penned Awassi wethers. The second and third observed the germination and establishment of legumes from faecal pellets in the field and in a glasshouse respectively. The fourth explored the possibility of transporting seeds from legume-rich (source) to legume-poor (target) grasslands using commercial flocks on communally-owned land. Seeds of small-seeded clovers passed through sheep in greater numbers (58–72%) than did seeds of larger-seeded species (10–40%). Of the clover seeds Trifolium campestre (seed size 0.45 mg) disintegrated least (72% passage) and T. haussknechtii (seed size 2.68 mg) disintegrated most (10% passage). Recoveries of Medicago noeana and Scorpiurus muricatus seeds were larger than expected on the basis of their seed sizes. Maximum rate of recovery was at 36 h after the seed meal for all species, all seeds were recovered by 120 h and 90% of the recovered seeds were passed in 72 h. Ingestion had little effect on the hardness and viability of most seeds. Experiments 2 and 3 suggested that seeds in pellets germinated and established as successfully as naked seeds. Burial increased establishment, whether in the field or under conditions of low moisture stress in the glasshouse. The small-seeded clovers, T. tomentosum and T. campestre, established most successfully whether from pellets or from naked seeds. About 500 seeds m−2 were successfully transported from the source to the target grassland. About half were Trigonella monspeliaca, a naturally-occurring legume found on both the source and target grasslands. Of the species sown on the source grassland, 115 seeds m−2 of Trifolium campestre (33% of the source seed bank), 62 seeds m−2 of T. tomentosum (27%) and 78 seeds m−2 of T. purpureum (21%) were detected in the target. Few medics were transported (for example, <2% of M. noeana). Apart from Trigonella monspeliaca, Trifolium tomentosum (16 plants m−2) was the most frequent species found in the target grassland in the following April. The results suggest that using sheep is a cheap and practical way of dispersing the seeds of pasture legumes and thereby improving the degraded grasslands of north Syria. They clearly demonstrate the role of small-seeded legumes (<1 mg) in grassland improvement, especially the small-seeded clovers.
Do malaria parasites mate non-randomly in the mosquito midgut?
Authors: ANDERSON T. J. C. , PAUL R. E. L. , DONNELLY C. A. , DAY K. P.
Published: July 2002

Polymerase chain reaction (PCR)-based genotyping of oocysts dissected from mosquito midguts
has previously been used to investigate overall levels of inbreeding within malaria parasite
populations. We present a re-analysis of the population structure of Plasmodium falciparum
malaria using diploid genotypes at three antigen-encoding loci in 118 oocysts dissected from 34
mosquitoes. We use these data to ask whether mating is occurring at random within the mosquito
midgut, as is generally assumed. We observe a highly significant deficit of heterozygous oocysts
within mosquitoes at all three loci, suggesting that fusion of gametes occurs non-randomly in the
mosquito gut. A variety of biological explanations, such as interrupted feeding of mosquitoes,
positive assortative mating and outcrossing depression, could account for this observation.
However, an alternative artefactual explanation – the presence of non-amplifying or null alleles –
can account for the observed data equally well, without the need to invoke non-random mating.
To evaluate this explanation further, we estimate the frequencies of null alleles within the oocyst
population using maximum likelihood, by making the assumption that non-amplifying oocysts at
any of the three loci are homozygous for null alleles. Observed levels of visible heterozygotes fit
closely with those expected under random mating when non-amplifying oocysts are accounted for.
Other lines of evidence also support the artefactual explanation. Overall inbreeding coefficients
have been recalculated in the light of this analysis, and may be considerably lower than those
estimated previously. In conclusion, we suggest that the deficit of heterozygotes observed is
unlikely to indicate non-random mating within the mosquito gut and is better explained by
misscoring of heterozygotes as homozygotes.
Is group selection a factor modulating the virulence of

RNA viruses?
Authors: MIRALLES ROSARIO , MOYA ANDRÉS , ELENA SANTIAGO F.
Published: July 2002

RNA viruses consist of populations of extremely high genetic

heterogeneity called quasispecies.

Based on theoretical considerations, it has been suggested that the unit

of selection in such

complex genetic populations is not the single viral particle but a set

of genetically related particles

which form the quasispecies. In the present study we carried out a set

of experiments with the

vesicular stomatitis virus (VSV) dealing with the evolution of

life-history characters under selection

acting at two factors either in the same or in opposite directions. The

two factors at which

selective pressure is applied are the individual and the group. We show

evidence that group

selection modulates the virulence of VSV populations, in opposition to

an unlimited increase in

virulence by competitive optimization promoted by individual selection.

The results are of

relevance for understanding the evolution of parasite virulence.
Microsatellite variation in populations of Drosophila
pseudoobscura and Drosophila persimilis
Authors: NOOR MOHAMED A. F. , SCHUG MALCOLM D. , AQUADRO CHARLES F.
Published: July 2002

We have isolated, characterized and mapped 33 dinucleotide, three trinucleotide and one
tetranucleotide repeat loci from the four major chromosomes of Drosophila pseudoobscura. Average
inferred repeat unit length of the dinucleotide repeats is 12 repeat units, similar to D. melanogaster.
Assays of D. pseudoobscura and populations of its sibling species, D. persimilis, using 10 of these
loci show extremely high levels of variation compared with similar studies of dinucleotide repeat
variation in D. melanogaster populations. The high levels of variation are consistent with an
average mutation rate of approximately 10−6 per locus per generation and an effective population
size of D. pseudoobscura approximately four times larger than that of D. melanogaster. Consistent
with allozymes and nucleotide sequence polymorphism, the dinucleotide repeat loci reveal minimal
structure across four populations of D. pseudoobscura. Finally, our preliminary recombinational
mapping of 24 of these microsatellites suggests that the total recombinational genome size may be
larger than previously inferred using morphological mutant markers.
First record of Lower Silurian conodonts from South America:
biostratigraphic and palaeobiogeographic implications of
Llandovery conodonts in the Precordillera of Argentina
Authors: LEHNERT OLIVER , BERGSTRÖM STIG M. , BENEDETTO J. L. , VACCARI N. EMILIO
Published: July 2002

A collection of conodonts, including Dapsilodus obliquicostatus
(Branson & Mehl),
Distomodus cf. kentuckyensis Branson & Branson, Ozarkodina
oldhamensis (Rexroad), and Panderodus
sp., has been obtained from brachiopod coquinas in the lower part of the
La Chilca Formation in the
Precordillera of west-central Argentina. This conodont fauna, the first
to be recorded from the
Llandovery in South America, can be referred to the D. kentuckyensis
Biozone, and is interpreted to
represent an interval in the middle Rhuddanian to lower Aeronian stages.
This age assignment is supported
by graptolite data from the lower third of the La Chilca Formation beneath
the conodont-bearing
interval. The brachiopods associated with the conodonts belong to the Afro-South
American
Realm, but include a high percentage of North Atlantic and cosmopolitan
genera. The conodont taxa
present are widespread in the tropical zone (Laurentia, Baltica, etc.).
This suggests that the pronounced
conodont faunal provicialism in the Upper Ordovician had disappeared in
the Lower
Silurian, where high- and low-latitude conodont faunas appear to be closely
similar.
ENGLISH ‘FEMINIST’ WRITINGS AND JUDITH DRAKE'S AN ESSAY IN DEFENCE OF THE FEMALE SEX (1696)
Authors: SMITH HANNAH
Published: July 2002

English ‘feminist’ writings of the late seventeenth century frequently united pro-woman arguments with party-political polemics. But although such texts have been discussed in terms of rationalist and contractarian philosophy, or as forerunners of modern feminist concerns, the contemporary issues which underscore them have been ignored. However, an understanding of these debates is vital to comprehending fully the motives of pro-woman writers, many of whom were more concerned with the survival of the Church of England than ameliorating the lot of seventeenth-century women. The underlying importance of party politics is exemplified in one of the greatest works of early modern ‘feminism’, Judith Drake's An essay in defence of the female sex (1696). Although Drake shared political similarities with other tory ‘feminists’, including the more celebrated Mary Astell, Drake's work differed radically from theirs over how an Anglican tory society could be maintained. Instead of stressing the necessity of teaching the tenets of Anglicanism to young women, as had her predecessors, Drake combined tory ideas with Lockean philosophy and concepts of ‘politeness’ to formulate an early Enlightenment vision of sociable, secularized, learning and the role female conversation could play in settling a society fractured by party politics.
MR ATTORNEY GENERAL AND THE POLITICIANS
Authors: MELIKAN R. A.
Published: July 2002

This article looks at the relationship between professional and

political aspiration in

Georgian England by examining the office of attorney general during

the period 1714–1810. It argues

that while the office offered a unique opportunity for a lawyer to

combine a legal and political career,

this was a formidable task and one rarely achieved. The generally

hostile attitude toward lawyers

in the house of commons was a significant obstacle. More

important, however, were the complex and

potentially conflicting expectations associated with the office

of attorney. The relationship with the

government was an awkward balance of loyalty and remoteness, whereby

the attorney was encouraged

to regard fellow ministers both as colleagues and as clients. Moreover,

he owed a duty to parliament

that was independent of, but inevitably linked to, his obligations to

the crown. As a consequence of

these various pressures attorneys tended to remain aloof from

politics and interested primarily in their

own professional advancement. The office of attorney general was

less the stepping-stone to ministerial

office than the reliable path to the bench.
MODERNITY AND GENDER IN ARAB ACCOUNTS OF THE 1948 AND 1967 DEFEATS
Authors: Hasso Frances S.
Published: July 2002

The victory which the Zionists have achieved…lies not in the superiority of one people over another, but rather in the superiority of one system over another. The reason for this victory is that the roots of Zionism are grounded in modern Western life while we for the most part are still distant from this life and hostile to it. They live in the present and for the future while we continue to dream the dreams of the past and to stupify ourselves with its fading glory.1
Evaluation of groundnut genotypes for heat tolerance under field conditions in a Sahelian environment using a simple physiological model for yield
Authors: NTARE B.R. , WILLIAMS J.H. , DOUGBEDJI F.
Published: July 2002

Heat tolerance of groundnut (Arachis hypogaea L.) was evaluated under field conditions using physiological traits identified in a yield model [crop growth rate (C), reproductive duration (Dr) and partitioning (p)]. In 1991, 625 diverse genotypes were initially screened under irrigation during the hottest months (February to May). Subsequent tests consisted of 16 contrasting genotypes selected based on a combination of high pod yield and partitioning coefficient of >0· 50. Large variation was observed among the 625 genotypes for pod yield and physiological traits. C was a powerful factor influencing pod yield. Eight genotypes combining high pod yield and a partitioning coefficient greater than 0·6 were identified. These included two released cultivars (55–437 and 796) in the Sahel. Correlations between seasons were significant for p (r=0·84), but non-significant for pod yield (r=0·40), C (r=0·39), and Dr (0·36). Date of sowing and genotypes had significant effects on pod yield and C, but were slight on p and Dr. Pod yield of most genotypes declined by more than 50% when flowering and pod formation occurred when maximum temperatures averaged 40°C. The results revealed that estimates of p would be a more reliable selection criterion for identification of genotypes tolerant to heat than yield. Further research is suggested to maximize crop growth rate and partitioning of genotypes growing under supra-optimal temperatures.
Response of spring wheat to phosphorus and sulphur starter fertilizers of differing acidification potential
Authors: GOOS R. J. , JOHNSON B. E.
Published: July 2002

Phosphorus (P) availability is often restricted in alkaline soils. The objective of this study was to determine if the plant availability of P from liquid ammonium polyphosphate fertilizer (APP) would be enhanced when blended with fluid sulphur (S) sources of differing acidification potential. Eight field studies with ‘ Butte 86 ' hard red spring wheat (Triticum aestivum L.) were conducted in 1995 and 1996 in eastern North Dakota, USA, comparing no P, 9·8 kg/ha of P, and 9·8 kg P/ha plus 11·2 kg S/ha from different S sources. The S sources were elemental sulphur (ES), ammonium sulphate (AS), ammonium bisulphite (ABS), ammonium thiosulphate (ATS), potassium thiosulphate (KTS) and potassium sulphate (KS). The P and S fertilizers were banded with the seed at planting. Phosphorus fertilization gave a typical ‘starter effect’, stimulating tillering, early growth and P uptake. Phosphorus uptake at the 4–5 leaf stage was increased by addition of acid-forming S fertilizers to the APP. Grain yield response to P applied with the seed was typically 400 kg/ha. The enhanced P uptake observed at the 4–5 leaf stage when certain S sources were added to APP did not lead to additional grain yield. Wheat grain yield in North Dakota comes almost entirely from the contributions of the main stem, T1 and T2 tillers, and initiation of these tillers was essentially complete when APP alone was banded with the seed.
The energy expenditure of cattle and buffaloes walking and working

in different soil conditions
Authors: DIJKMAN J. T. , LAWRENCE P. R.
Published: July 2002

At the Centre for Tropical Veterinary Medicine, Scotland,

during the summer months of 1987, two adult water buffaloes, two

Brahman cattle and two Brahman × Friesian steers walked round a

circular track on concrete or through 300 mm deep mud. Average

walking speed (m/s) when unloaded, or average walking speed

(m/s) when pulling 324 N, energy for walking (J/m/kg) and

net mechanical efficiency (%) were 1·05 and 0·81 (P

< 0·01), 1·03 and 0·80 (P < 0·001),

1·49 and 3·34 (P < 0·001) and 31·0 and

31·8 for concrete and mud respectively. Energy values were

calculated from gaseous exchange measured with an open circuit

system.

In Central Nigeria, from September 1991 to May 1992, the energy

expenditure of eight Bunaji (White Fulani) bulls was monitored using

portable oxygen measuring equipment (modified ‘Oxylog’)

when walking, ploughing and harrowing on six soil surfaces ranging

from hard, smooth earth to ploughed, waterlogged clay. Average

walking speeds (m/s), pulling speeds (m/s) and energy cost of

walking (J/m/kg) varied from 0·97 to 0·65,

0·55 to 0·47 and 1·47 to 8·58

respectively. Net mechanical efficiency averaged 31·4% and was

unaffected by ground surface.

The energy cost of walking for the Bos indicus cattle on

smooth ground (1·47 J/m/kg) in this trial was less than

that previously reported for Bos taurus (1·80

J/m/kg) and the reported average value for cattle (Bos

indicus and Bos taurus) on treadmills (2·09

J/m/kg). The implications for practical agriculture of the

higher levels of energy expenditure for walking in muddy conditions are

discussed.
Effect of a plant growth regulator regime on internode

length and weight of tillers in conventional and hybrid

rye and the impact of nitrogen on crop performance
Authors: FROMENT M. A. , McDONALD H. G.
Published: July 2002

The effect of nitrogen and a plant growth regulator regime (chlormequat

chloride followed by 2-chloroethylphosphonic acid) on the crop performance
of

a hybrid (cv. Luchs) and a conventionally

bred winter rye (cv. Sentinel) were investigated in two field experiments
each

year between 1993 and

1995 at Winchester, UK. Internode length and dry weight/unit length
of

internodes was measured

in order to assess the effect of the growth regulator regime on stem structure.

Grain yields were 15%

higher in the hybrid Luchs than in Sentinel. With high levels of applied

nitrogen, both cultivars

lodged in all seasons and this was most severe in 1994 when 88% of the
crop

lodged in Sentinel and

52% in Luchs. Plant growth regulator treatment consistently reduced lodging
but

did not eliminate

it. Reductions in lodging were not always associated with an increase in

grain yield. In the hybrid

cultivar, the growth regulator treatment reduced yield in 1993 and 1995
when

2-chloroethyl-phosphonic acid was applied at GS49 and GS39 respectively,

but increased yield in 1994 when applied

at GS37. Growth regulator consistently reduced stem length, and the percentage

reduction in length

of the individual internodes within the stem was strongly influenced by
the

timing of the 2-chloroethylphosphonic acid component of the PGR treatment.

Growth regulator reduced internode

lengths by up to 25% in Sentinel and 35% in Luchs, and this was associated

with reductions in the

dry weight of internodes by up to 32% in Sentinel and 38% in Luchs. Consequently,

dry weight/unit

length of the stem was not increased by growth regulator treatment. Yield

reductions in Luchs

following growth regulator treatment may have been due to reduced stem
reserves

which have been

associated with tolerance of stress in rye. Both cultivars were highly
responsive

to nitrogen. Economic

optima varied from season to season, but they ranged over three years,
from

175–273 kg/ha nitrogen,

and were greater than the currently recommended application rates. Crop
lodging

increased with

increasing nitrogen rate even when plant growth regulator was applied and

yield penalties from lodging would have been high, if weather conditions

during grain maturity had been unfavourable.
Effects of rainfall and temperature on the feeding value

of barley straw in a semi-arid Mediterranean environment
Authors: GOODCHILD A. V.
Published: July 2002

Annual variation in the feeding value of barley straw

(Hordeum vulgare L. subsp. vulgare) is

economically significant in the Mediterranean region. The relationship
between

the feeding value for

sheep of several winter-planted barley cultivars and monthly meteorological
data

was analysed at Tel

Hadya, northwest Syria (mean annual precipitation 330 mm) in 11 years.

Indicators of feeding value

included contents of neutral detergent fibre, acid detergent fibre and

nitrogen (11 years), voluntary

straw intake by sheep (10 years), voluntary digestible organic matter intake

(9 years), in sacco dry

matter loss and lignin content (8 years), in vitro digestibility

(7 years) and in vitro gas production (6

years). Monthly meteorological data included total precipitation, mean
minimum

and mean maximum air temperatures.

Conditions likely to decrease grain yield tended to increase the feeding

value of straw. Low mean

minimum temperature in February, low precipitation in January, February,

March and April, and

high mean maximum temperature in March, April and May increased one or

more indicators of straw

feeding value (by both bivariate and multiple regression,

P<0·05). Precipitation before January

affected grain and straw yield but had little effect on the feeding

value of straw.

Genotype × year interactions had a meteorological component; the
superior

feeding value of the

straw of locally-adapted cultivars v. exotic cultivars

was only seen in years with cool or wet springs.

This has implications for the genetic selection of crops with better

straw feeding value.

Models based on monthly precipitation and temperature, calibrated for

locations in the

Mediterranean region, can predict the nutritive value of straw and aid

the planning of rations for small ruminants.
Quantitative analysis of Linum usitatissimum crosses
for dual-purpose traits
Authors: FOSTER R. , POONI H. S. , MACKAY I. J.
Published: July 2002

The commercial future of Linum usitatissimum is intrinsically
linked to its cultivation as a dual-purpose
crop for producing increased seed and fibre yields. The present
study evaluates 36 F1 crosses
derived from nine linseed/flax accessions for their potential as dual-purpose
cultivars and/or their
suitability for extracting new recombinants producing high seed yield as
well as increased fibre
output. The quantitative analysis indicated that variation
between the F1 families is largely but not
exclusively due to the additive and non-additive (dominance) effects of
genes. Dominance is high for
plant height (H1), height at maturity (HMT), number of branches (NBr) and
seed weight (SdWt)
while 100 seed weight (Wt100) displays no dominance at all. The repeatability
estimates representing
the heritability of each trait, vary from low (0·20) for number
of branches (NBr) to high (0·71) for
height at flowering time (HFT). The dual-purpose traits such as seed weight
(SdWt) and straw weight
(StWt) were only moderately inherited while flowering time (FT) and various
heights were rather
highly heritable. A moderate and positive correlation (r=0·57)
between StWt and SdWt, and a
completely independent inheritance of Wt100 suggested that there are good
chances of combining
these traits into a single genotype. The phenotypic performance of the
crosses also confirmed this
trend and at least four crosses showed superior performance for both SdWt
and StWt compared to
their parental lines. All these crosses involved a linseed line (B3) as
a common parent and the second
parent was either another linseed line (A1 and A3) or a flax accession
(K3 and L2); none of the
flax×flax crosses showed good potential for seed yield. While all
four crosses possess the potential
to become highly productive, dual-purpose, hybrid varieties, the extraction
of desirable inbred lines
from them, however, may prove difficult because the superior performance
of the hybrids seems
largely due to strong unidirectional dominance and high SCA effects.
The protective action of tannins against glasshouse
whitefly in tomato seedlings
Authors: BIAŁCZYK JAN , LECHOWSKI ZBIGNIEW , LIBIK ANDRZEJ
Published: July 2002

The synthesis and accumulation of tannins on tomato seedlings are regulated by environmental
factors. The variation in the content of tannins was sufficiently important to bring about the
occurrence of significant differences in the numbers of glasshouse whitefly on the seedlings. During
a 2-week experiment, the treatments included mechanical wounding (20 prickings per cm2), spraying
with kinetin solutions of 10−4 mol/dm3, plant growth regulators, and the atmosphere enrichment to
680 μmol CO2/mol air, the content of tannins being increased by c. 40, 70, 10–45 and 25% above the
values obtained in the control. These results were correlated with a decrease in the numbers of insects
occurring on the seedlings by c. 35, 45, 8–29 and 18%, respectively. Contrary to the above results the
spraying with solutions of abscisic acid, gibberellic acid, and the incubation of plants in an
atmosphere containing 170 μmol CO2/mol air, reduced the content of tannins by c. 69, 22 and 25%,
respectively. This was reflected in the respective increases by c. 70, 40 and 35% in the numbers of
insects occurring on the seedlings. The obtained results suggest that tannins seem to have a dosage-dependent effect on glasshouse whitefly. Decreasing the host plant quality by increasing tannin
content may act as an important selective agent limiting the losses brought about by glasshouse
whitefly in tomato cultivation.
Forecasting growth and yield of groundnut
(Arachis hypogaea) with a dynamic simulation model
‘PNUTGRO’ under Punjab conditions
Authors: KAUR PRABHJYOT , HUNDAL S. S.
Published: July 2002

The dynamic simulation model ‘PNUTGRO’ was used to predict groundnut growth and yield from
1989 to 1993 at Ludhiana, India. The simulated flowering, pegging and physiological maturity dates,
leaf area index (LAI), pod and seed yields and shelling percentage of groundnut were compared with
actual observations for the commonly grown cultivar, M-335. The simulated phenologic events
showed deviations of only −3 to +3 days for flowering, −3 to +2 days for pegging and −4 to +2
days for physiological maturity of the crop. The model estimated the LAI to be within 95–108%
(mean 101·5%) and shelling percentage to be within 93–108% (mean 100·5%) of the actual values.
The model predicted the pod yields from 89 to 111% (mean 100%) and seed yield from 90 to 110%
(mean 100%) of the observed yields. The results obtained with the model for the five consecutive crop
seasons revealed satisfactory predictions of phenology, growth and yield of groundnut and hence the
model ‘PNUTGRO’ can be used for prediction of groundnut production in the central plains of the
Indian Punjab.
In vitro short-term study of ammonium–nitrogen
production from cattle urine: influence of ampicillin,
hydroquinone and animal litter materials
Authors: NIMENYA H. , DELAUNOIS A. , BLODEN S. , LA DUONG D. , CANART B. , NICKS B. , GUSTIN P. , ANSAY M.
Published: July 2002

The production of NH+4-N following in vitro incubation of cattle
urine was monitored for 24 h in the
presence of ampicillin sodium salt (0, 32, 64, 128 mg/l), hydroquinone (0, 16·7, 33·4, 66·8 mg/l),
wheat straw (0, 3·3, 6·6, 13·2 g/l) or spruce sawdust (0, 3·3, 6·6, 13·2 g/l) with (20 IU) or without
urease. Each concentration of ampicillin, hydroquinone, wheat straw or spruce sawdust was tested
in triplicate.

The equipment consisted of Woulff flasks containing 300 ml of a buffered solution (0·02 M; pH
7·50) with 1 ml of cattle urine. The cattle urine was characterized by measuring the main nitrogen
contents, which were 6·52 mg total-N/ml, 5·96 mg urea-N/ml and 0·026 mg ammonium-N/ml. The
initial pH of urine was 7·84. Ammonium and nitrate concentrations, and pH were monitored at zero-
time and after 3, 6 and 24 h of incubation with the cattle urine.

The addition of urease to the flasks containing urine induced a significant increase in the
production of ammonium-N, from 1·83 to 6·32 mg NH+4-N/flask after 24 h of incubation.

In the presence of urease, an inhibitory effect was recorded in NH+4-N production with ampicillin
and spruce sawdust. In contrast, hydroquinone inhibited urease activity and wheat straw adsorbed
the NH+4-N produced, both causing a dose-dependent relationship.

In the absence of urease, ampicillin, hydroquinone, wheat straw or spruce sawdust caused a dose-
related decrease in NH+4-N production. However, the highest amounts of wheat straw (6·6 and
13·2 g/flask) exhibited a temporary increase in NH+4-N production during the first 6 h. This is
probably due to a generation of extra NH+4-N as compared to the control flasks without straw.
However, at 24 h, the situation paralleled the other materials.

Although pH increased approximately from 7·50 to 7·65 during the hydrolysis of urea in the
presence of urease, no gaseous ammonia was volatilized into a 0·1 M HCl flask. Moreover, no increase
in nitrate concentration was found during the incubation.

The present results suggest that ampicillin, hydroquinone and spruce sawdust could be used in
order to reduce NH+4-N production from cattle urine. The
NH+4-N already produced could probably be absorbed on wheat straw.
Changes in cow teat tissue created by two types of milking cluster
Authors: HILLERTON J. ERIC , OHNSTAD IAN , BAINES JOHN R. , LEACH KATHARINE A.
Published: July 2002

We have investigated the responses of cow teats to machine milking in a
study of relatively newly installed commercial milking parlours fitted with one of two
types of milking cluster. The first was a common type with a large claw volume
(> 200 ml), 15–16 mm i.d. long milk tube, 10 mm short pulse tube, cluster weight
< 3·2 kg and used alternate pulsation. The second was a more traditional type with
a 150 ml claw bowl volume, 13·5 mm i.d. long milk tube, 8 mm short pulse tube,
cluster weight ∼ 3·5 kg and used simultaneous pulsation. We scored ∼ 50 cows in
each of 20 herds, all within 60 s of cluster removal, for changes from the premilking
teat condition: teat colour (creation of reddening or blueness), firmness, thickening
at the base of the teat associated with the position of the liner mouthpiece, and
whether the teat duct orifice was open. There were statistically significant differences
in the proportion of cows displaying these four alterations in teat condition between
herds using the two types of cluster. The more common type of cluster was always
associated with better teat condition. The cause and effect of poorer teat condition
have not been fully established and are likely to be multifactorial. The principal risk
factors may be cluster weight, overmilking, vacuum applied during the overmilking
phase and the design of the liner mouthpiece.
Coagulating and lipolytic activities of artisanal lamb rennet pastes
Authors: BUSTAMANTE MARIAN , CHÁVARRI FELISA , SANTISTEBAN ARANTZA , CEBALLOS GERARDO , HERNÁNDEZ IGOR , MIGUÉLEZ M. JOSÉ , ARANBURU IZPIÑE , BARRÓN LUIS J. R. , VIRTO MAILO , DE RENOBALES MERTXE
Published: July 2002

Lamb rennet pastes were prepared by the procedure most commonly used
by Idiazabal cheese manufacturers. We studied the effects on their coagulating and
lipolytic activities of the state of the stomach at the time of death (full of milk or
empty), the amount of NaCl added, the origin of the lambs and paste storage time.
Coagulating activities were generally between 155 and 363 units/g tissue. Pastes
prepared from stomachs of lambs from slaughterhouse flocks had significantly higher
coagulating activities than those of lambs from separate flocks. No significant
decrease in coagulating activity was observed after 1 year storage at 4 °C. Chymosin
represented 75–80% of the total coagulating activity with the remainder being
pepsin. Rennet paste extracts with pH < 4·7 did not have increased coagulating
activities when their pH was lowered to 2·0, while those with pH > 5·2 had activities
1·5-fold those before treatment. Lipase activity was higher in extracts of rennet
pastes prepared using the stomachs of lambs that arrived at the slaughterhouse in
the morning just prior to slaughter than in those prepared with the stomachs of
lambs that had arrived on the previous evening. However, the reverse was the case
for esterase activity. Activating the coagulating activity by pH cycling completely
destroyed both lipolytic activities. Storage at 4 °C for > 1 year did not affect esterase
activity but lipase activity decreased substantially after 4–5 months. Lipase, but not
esterase, activity was responsible for the liberation of short-chain free fatty acids
from ovine milk fat.
Enzymatic assays for native plasmin, plasminogen and plasminogen activators in bovine milk
Authors: SAINT-DENIS THIERRY , HUMBERT GÉRARD , GAILLARD JEAN-LUC
Published: July 2002

Rapid and sensitive assays for plasmin, plasminogen and plasminogen activators (PA) were developed and applied to bovine milk. The reaction medium was clarified by addition of a dissolving agent after hydrolysis of a fluorescent substrate specific for plasmin. This final step enabled the use of larger sample amount with higher substrate concentration than other methods, and avoided previous sample preparation. The use of 4 g gelatin/l in buffers preserved plasmin activity, thus avoiding risks of overestimation of the assays results. Sensitivity, detection level, repeatability and analysis run time of plasmin and plasminogen assay were improved over previous enzymatic methods with synthetic substrates. The PA assay was assessed by measuring conversion of exogenous plasminogen into plasmin. A new kinetic approach was used to enable the direct determination of global PA activities on raw milk samples without interference from indigenous plasmin.
Immunomodulating effects of milks fermented by Lactobacillus helveticus and its non-proteolytic variant
Authors: MATAR CHANTAL , VALDEZ JUAN CARLOS , MEDINA MARCELA , RACHID MIRTHA , PERDIGON GABRIELA
Published: July 2002

The effect of milks fermented by Lactobacillus helveticus and its non-proteolytic variant on mucosal and tumoral immunity was studied. Milks fermented by Lb. helveticus wild type or its non-proteolytic variant were administered orally to mice for different periods (3, 5 and 7 d). The immune response was assessed by analysing the activity of the peritoneal macrophages, the number of cells secreting IgA associated with the gut-associated lymphoid tissue and with the bronchial-associated lymphoid tissue. The number of cells was determined by direct immunofluorescence. The antitumour activity was monitored by studying the regression of the subcutaneously implanted fibrosarcomas. After 3 d feeding of milk fermented by Lb. helveticus wild type, the number of sIgA increased significantly at both the intestinal and bronchial levels, indicating that a cellular migration had occurred. This effect was not noticeable when milk fermented by Lb. helveticus Protease (−) was orally administered. Both fermented milks (wild type or its variant) exhibited an effect on the activity of the peritoneal macrophages, which might be indirectly correlated to the regression of the fibrosarcoma. Although the mechanism by which the lactic acid bacteria enhance the immune system is not clear, this study clearly suggests that the bioactive compounds released during milk fermentation might contribute to the immunoenhancing properties of these products. By releasing biopeptide, lactic acid bacteria have important implications in modulation of the host's immune response, more specifically its cellular immune response.
Inhibition of oxytocin release and milk let-down in postpartum primiparous cows is not abolished by naloxone
Authors: KRAETZL WOLF-DIETER , TANCIN VLADIMIR , SCHAMS DIETER
Published: July 2002

About 10% of primiparous cows have no milk ejection during the first milkings after delivery. Therefore, 17 Brown Swiss dairy cows in their first lactation were used to evaluate the extent of disturbed milk let-down and the corresponding oxytocin (OT) plasma values in the 1st 5 days after delivery. The first milking was 9–22 h after parturition and served for classification of the cows to groups with inhibited (INH), bimodal (BIMO) or normal (NOR) milk let-down. The OT plasma levels before the start of manual teat stimulation and machine milking were comparably high during the first milking especially in NOR and BIMO cows. Ten minutes before the second milking (M2), 300 mg of the opioid antagonist naloxone was injected to test whether the disturbance was affected by the action of endogenous opioids on the neurohypophysis. The milk yield was not influenced by the naloxone treatment, and the INH cows had milk ejection only after a vaginal stimulation. Afterwards, the cows were milked twice every day, until the milk let-down and the OT release were unaffected (equal to control milking). Then, at the next milking, the cows were injected with 300 mg morphine 10 min before milking. The central OT release in response to manual teat stimulation and machine milking was completely blocked in all cows, but a vaginal stimulation was able to abolish this block, at least partially, in 16 cows. Thus, morphine produced a milk let-down characteristic as in the INH cows during the first three milkings. For the following milking, the cows were pre-treated with 300 mg naloxone (−15 min) plus 300 mg morphine (−10 min) before milking. The OT release and the milk yields were unaffected when compared with the control milking. This experiment demonstrates that exogenous opioids can affect the central release of OT in a naloxone-reversible manner even very soon after parturition. However, endogenous opioids are probably not the main mediators of disturbed central OT release and alveolar milk ejection in post-partum primiparous cows.
Inhibition of milk ejection in cows by oxytocin receptor blockade,
α-adrenergic receptor stimulation and in unfamiliar surroundings
Authors: BRUCKMAIER RUPERT M. , WELLNITZ OLGA , BLUM JÜRG W.
Published: July 2002

Inhibition of milk ejection in cows by oxytocin receptor blockade
(Atosiban) and α-adrenergic receptor stimulation (phenylephrine) prior to
prestimulation was compared with inhibition of milk ejection
in unfamiliar surroundings.
In addition, Atosiban and phenylephrine were administered after a 1 min
prestimulation or 1 min after the start of milking. Oxytocin
concentrations increased
during milking in all treatments. The spontaneously removed milk fraction (before
oxytocin was injected) was similar for Atosiban and phenylephrine treatments and
in unfamiliar surroundings, but lower than in controls. Peak flow rates were similar
in all treatments, but reduced as compared with controls when phenylephrine and
Atosiban were administered before prestimulation. Peripheral (Atosiban,
phenylephrine) and central (unfamiliar surroundings) inhibition of
milk ejection reduced
the amount of available milk similarly. Drug treatments resulted in
similar peak flow
rates; however, teats were contracted after phenylephrine administration but not
after Atosiban. The inhibition induced by Atosiban could be abolished by oxytocin
injection, but not that induced by phenylephrine, which was antagonized by
α-adrenergic receptor blockade. These results indicate that
inhibition of milk ejection
through activation of α-adrenergic receptors is based on blockade
of milk flow into the cistern, but not through the teats.
Rheological properties at small (dynamic) and large (yield)
deformations of acid gels made from heated milk
Authors: LUCEY JOHN A. , TEO CHENG TET , MUNRO PETER A. , SINGH HARJINDER
Published: July 2002

The effect of a range of milk heat treatments on the rheological
properties,
at small and large deformations, of acid skim milk gels was investigated.
Gels were
made from reconstituted skim milk heated at 75, 80, 85 and 90°C for
15 or 30 min
by acidification with glucono-δ-lactone at 30°C. Gels were also

made from skim milk
powder (SMP) samples that had been given a range of preheat treatments
during
powder manufacture. Heating milks at temperatures [ges ]80°C for 15
min increased
the storage moduli (G′) compared with unheated milk and

produced gels with G′ in
the range 300–450 Pa. Acid gels made from high-heat or medium-heat
SMP had
higher G′ than gels made from low-heat or ultra-low-heat

SMP. Cooling gels to low
temperatures resulted in an increase in G′. The yield
stress of gels slightly decreased
with mild heat treatments of milk, and then increased again to a maximum,
finally
decreasing slightly with very high heat treatments of milk. The strain
at yielding
decreased markedly with increasing heat treatment of milk, making these
gels brittle
and easier to fracture. We propose that denatured whey proteins aggregated
with
casein particles during the acidification of heated milk and were
responsible for most of the effects observed in this study.
Naloxone and adrenergic blocking agents fail to abolish central
inhibition of milk ejection in cows
Authors: WELLNITZ OLGA , BRUCKMAIER RUPERT M. , BLUM JÜRG W.
Published: July 2002

Emotional stress caused by moving to unfamiliar surroundings inhibits

oxytocin (OT) release and milk ejection in dairy cows, while blood concentrations

of β-endorphin and cortisol are elevated (Bruckmaier et al.

1993). β-Endorphin and
cortisol concentrations decrease with repeated relocation to unfamiliar
surroundings
while milking-related OT release and milk ejection gradually normalize
(Bruckmaier
et al. 1996). Exogenous cortisol has previously been shown to
exert
no inhibiting
effect on milk ejection in cows (Mayer & Lefcourt, 1987). Therefore,
it
seems likely that the inhibition of milk ejection in cows – as in
other species
– is mediated by
endogenous opioid peptides. The opioid antagonist naloxone abolishes the
inhibiting
effect of endogenous opioid peptides on OT release in several species
(Haldar et al.
1982; Seckl & Lightman, 1987; Gilbert et al. 1992; Aurich

et al. 1996).

Milk ejection is inhibited by α-adrenergic receptor stimulation

in the mammary
gland without reduction of OT release (Bruckmaier et al. 1997).

Opioid-induced
inhibition of OT release may be mediated by noradrenergic neurons via
β-adrenergic
receptors (Crowley & Armstrong, 1992). If adrenergic receptors are

involved in the
blockade of OT release in cows during milking in unfamiliar surroundings,
the
inhibition may be abolished by adrenergic blocking agents.

Cortisol synthesis is diminished by administration of metyrapone (Martindale,

1989). Because cortisol has a negative feedback effect on ACTH release,
the release
of ACTH and concomitantly of β-endorphin is elevated by metyrapone
in the rat
(Pettibone & Mueller, 1984). Thus, milk ejection should be
indirectly inhibited by
metyrapone administration via enhanced release of β-endorphin in
the familiar barn.

Experiments were designed to investigate the importance of elevated

concentrations of β-endorphin in unfamiliar surroundings for disturbed

milk ejection in dairy cows.