bluuebunny/crossref_metadata_2025 huggingface dataset:
GROWTH AND BIOMASS PARTITIONING OF MAIZE DURING VEGETATIVE GROWTH IN RESPONSE TO STRIGA HERMONTHICA INFECTION AND NITROGEN SUPPLY
Authors: Aflakpui G. K. S. , Gregory P. J. , Froud-Williams R. J.
Published: July 2002

The effect of the root hemiparasitic angiosperm Striga hermonthica on the gowth, photosynthesis and partitioning of biomass in maize was studied in glasshouse experiments in two seasons. In both seasons, nitrogen was applied to the plants at rates equivalent to 20, 60 and 120 kg ha−1. There was no significant Striga×nitrogen interaction on the responses measured. Averaged across all nitrogen treatments, maize plants infected with S. hermonthica had smaller leaf areas and accumulated less biomass, than did uninfected plants. The leaf area of infected and uninfected plants increased asymptotically from emergence to the final harvest (about the 18-leaf stage) at which time the leaf area of infected plants was 63% that of uninfected plants. The rates of photosynthesis of the youngest, fully expanded leaves of infected plants, averaged across N treatments, were significantly lower than for uninfected plants. However, stomatal conductance and the sub-stomatal CO2 concentration were unaffected by Striga infection. Although infection with Striga significantly reduced shoot biomass (dry weight at final harvest was 37% that of uninfected plants in 1995 and 63% in 1996), there were no significant effects of Striga infection on root biomass so that the infected plants partitioned a significantly greater proportion of their total biomass to roots compared with the uninfected plants. The allometric coefficients, though, were similar for both infected and uninfected plants. Averaged across infected and uninfected plants, application of nitrogen increased total leaf area per plant and root and shoot biomass but did not change the proportion of total biomass partitioned to roots. These results did not show a major effect of nitrogen on the relative growth response of maize to infection with Striga.
Extending the coalescent to multilocus systems: the case of balancing selection
Authors: BARTON NICK H. , NAVARRO ARCADIO
Published: July 2002

Natural populations are structured spatially into local populations and genetically into diverse ‘genetic backgrounds’ defined by different combinations of selected alleles. If selection maintains genetic backgrounds at constant frequency then neutral diversity is enhanced. By contrast, if background frequencies fluctuate then diversity is reduced. Provided that the population size of each background is large enough, these effects can be described by the structured coalescent process. Almost all the extant results based on the coalescent deal with a single selected locus. Yet we know that very large numbers of genes are under selection and that any substantial effects are likely to be due to the cumulative effects of many loci. Here, we set up a general framework for the extension of the coalescent to multilocus scenarios and we use it to study the simplest model, where strong balancing selection acting on a set of n loci maintains 2n backgrounds at constant frequencies and at linkage equilibrium. Analytical results show that the expected linked neutral diversity increases exponentially with the number of selected loci and can become extremely large. However, simulation results reveal that the structured coalescent approach breaks down when the number of backgrounds approaches the population size, because of stochastic fluctuations in background frequencies. A new method is needed to extend the structured coalescent to cases with large numbers of backgrounds.
BETWEEN REFORM AND REPRESSION: IMPRISONMENT IN WEIMAR GERMANY
Authors: WACHSMANN NIKOLAUS
Published: July 2002

This is the first account of the prison in the Weimar Republic (1918–33), set in the context of the evolution of German social policy. In the early years, the Weimar prison was characterized by hunger, overcrowding, and conflict. At this time, leading officials agreed on a new approach to imprisonment, influenced by the demand for the ‘incapacitation of incorrigibles, reformation of reformables’. This principle was championed by the modern school of criminal law, designed to replace traditional policy based on deterrence and uniform retribution. The policy of reform and repression shaped the Weimar prison. Most prison officials supported the indefinite confinement of ‘incorrigibles’. While this did not become law, many prisoners classified as ‘incorrigible’ (increasingly after ‘objective’ examinations) received worse treatment than others, both in prison and after their release. Regarding the ‘reformables’, some institutions introduced measures aimed at prisoner rehabilitation. But such policies were not fully implemented in other prisons, not least because of resistance by local prison officials. During the collapse of the Weimar Republic in the early 1930s, measures aimed at rehabilitation, only just introduced, were cut back again. By contrast, the repression of ‘incorrigibles’ was pursued with even more vigour than before, an important legacy for Nazi penal policy.
BEFORE THE WALL: EAST GERMANS, COMMUNIST AUTHORITY, AND THE MASS EXODUS TO THE WEST
Authors: ROSS COREY
Published: July 2002

Based on sources from the East German regime's internal archives, this article examines how the exodus of over 3 million people from the German Democratic Republic (GDR) before the construction of the Berlin Wall undermined the communist regime's ability to exert its authority over internal affairs. Instead of focusing on the relatively well-known economic and diplomatic costs of the mass exodus, it considers rather the grass-roots political ramifications of this unique phenomenon among the Soviet satellite states. The article focuses on three interrelated issues: first, the government's little-known efforts to curb and control emigration before the Wall; second, the myriad causes of the mass emigration and how these were perceived by the party/state apparatus; and third, the variety of strategies through which ordinary East Germans who stayed in the GDR attempted to use the possibility of flight to the West to enhance their bargaining position with state authorities. It argues that the refugees to the West were not the only East Germans to capitalize on the permeable border around West Berlin. The possibility of emigrating westwards also gave those who stayed a degree of power vis-à-vis the regime that they otherwise would not have had.
Evaluation of volatile compounds in different types of ghee using direct injection with gas chromatography-mass spectrometry
Authors: WADODKAR UDAY R. , PUNJRATH JAGJIT S. , SHAH AMRISH C.
Published: July 2002

Desi ghee (DG) was prepared from fermented cream followed by heat clarification (desi method) in the laboratory and butter oil (BO) was prepared from fresh butter by melting and centrifugation. Fresh samples of three brands of industrial ghee (IG-1, IG-2, IG-3) were collected from the local market. Volatile compounds of desi and industrial ghee and butter oil were isolated and concentrated using direct injection and cryofocussing techniques; separation and identification was by Gas Chromatography Mass Spectrometry (GCMS). A maximum of 36 compounds were detected in desi ghee whereas compounds detected in three industrial ghee samples varied from 22–29. The lowest number of compounds (16) was detected in butter oil. Of the identified compounds, maltol, 5-hydroxymethyl furfuraldehyde, dihydrodihydroxypyranone, 1,3-butanediol and 1-octanol were identified only in desi ghee volatiles. The concentration of acetic acid was found to be remarkably higher in desi ghee volatiles than in industrial ghee. Also the levels of identified fatty acids, methyl ketones, aldehydes, lactones and alcohols were high in desi ghee volatiles compared with industrial ghee and butter oil. In total, 62 compounds were detected, which included 6 aldehydes, 12 ketones, 8 each of fatty acids, alcohols and lactones, 4 each of esters and hydrocarbons or other compounds, and 12 compounds remained unidentified.
Effect of over-milking on teat condition
Authors: HILLERTON J. ERIC , PANKEY J. W. , PANKEY P.
Published: July 2002

Unsatisfactory milking conditions, including high milking vacuum, ineffective
pulsation, heavy clusters, unsuitable liners, poor teat preparation and over-milking,
are known to create poor, but undefined, teat conditions and pose a risk to an
increased probability of intramammary infection (IDF, 1994). It has been shown
that poor teat condition, seen as discolouration, abnormal firmness or thickened
rings of tissue distally, after cluster removal may be common in a variety of
commercial milking operations (Hillerton et al. 2000). That field study was
observational and teat conditions were influenced by a number of variables. A small
experimental study has been undertaken to develop an experimental model, under
controlled milking conditions, to allow investigation of potential causes of teat
trauma. Over-milking was suggested as highly important in the field observations
and so has been examined in this study.
Jet vectoring using synthetic jets
Authors: SMITH B. L. , GLEZER A.
Published: July 2002

The interaction between a conventional rectangular (primary) air jet and a co-flowing
synthetic jet is investigated experimentally. The nozzles of both jets have the same
long dimension but the aspect ratio of the synthetic jet orifice is 25 times larger.
Detailed particle image velocimetry (PIV) measurements of the flow in the midspan
plane show that primary jet fluid is directed into the synthetic jet orifice and the
interaction between the jets leads to the formation of a closed recirculating flow
domain. The concomitant formation of a low-pressure region between the jets results
in deflection of the primary jet toward the actuator jet despite the absence of an
extended control surface (e.g. a diffuser or collar) and is balanced by a force on the
primary jet conduit. For a given synthetic jet strength and primary jet speed, the
vectoring force depends mainly on the volume flow rate of primary jet fluid that is
diverted into the synthetic jet actuator. This flow rate is regulated by restricting the
flow of entrained ambient fluid using a small streamwise extension of the synthetic
jet orifice that scales with the orifice width. The response of the primary jet to the
imposed vectoring is investigated using stepped modulation of the driving signal.
The characteristic vectoring time and vectoring angle decrease monotonically with
primary jet speed.
An explicit potential-vorticity-conserving
approach to modelling nonlinear internal gravity waves
Authors: VIÚDEZ ÁLVARO , DRITSCHEL DAVID G.
Published: July 2002

This paper discusses a potential-vorticity-conserving approach to modelling nonlinear
internal gravity waves in a rotating Boussinesq fluid. The focus of the work is on the
pseudo-plane motion (motion in the x, z-plane), for which we present a broad range
of numerical results. In this case there are two material coordinates, the density and
the y-component of the velocity in the inertial frame of reference, which are related
to the x and z displacements of fluid particles relative to a reference configuration.
The amount of potential vorticity within a fluid region bounded by isosurfaces of
these material coordinates is proportional to the area within this region, and is
therefore conserved as well. Two new potentials, defined in terms of the displacements
and combining the vorticity and density fields, are introduced as new dependent
variables. These potentials entirely govern the dynamics of internal gravity waves
for the linearized system when the basic state has uniform potential vorticity. The
final system of equations consists of three prognostic equations (for the potential
vorticity and the Laplacians of the two potentials) and one diagnostic equation,
of Monge–Ampère type, for a third potential. This diagnostic equation arises from
the nonlinear definition of potential vorticity. The ellipticity of the Monge–Ampère
equation implies both inertial and static stability. In three dimensions, the three
potentials form a vector, whose (three-dimensional) Laplacian is equal to the vorticity
plus the gradient of the perturbation density.

Numerical simulations are carried out using a novel algorithm which directly evolves
the potential vorticity, in a Lagrangian manner (following fluid particles), without
diffusion. We present results which emphasize the way in which potential vorticity
anomalies modify the characteristics of internal gravity waves, e.g. the propagation of
internal wave packets, including reflection, refraction, and amplification. We also show
how potential vorticity anomalies may generate internal gravity waves, along with
the subsequent ‘geostrophic adjustment’ of the flow to a ‘balanced’ wave-less state.
These examples, and the straightforward extension of the theoretical and numerical
approach to three dimensions, point to a direct and accurate means to elucidate the
role of potential vorticity in internal gravity wave interactions. As such, this approach
may help a better understanding of the observed characteristics of internal gravity
waves in the oceans.
Unsteady natural convection in a triangular
enclosure induced by absorption of radiation
Authors: LEI CHENGWANG , PATTERSON JOHN C.
Published: July 2002

The authors have previously reported a model experiment on the unsteady natural
convection in a triangular domain induced by the absorption of solar radiation. This
issue is reconsidered here both analytically and numerically. The present study consists
of two parts: a scaling analysis and a numerical simulation. The scaling analysis for
small bottom slopes reveals that a number of flow regimes are possible depending on
the Rayleigh number and the relative value of certain non-dimensional parameters
describing the flow. In a typical situation, the flow can be classified broadly into a
conductive, a transitional or a convective regime determined merely by the Rayleigh
number. Proper scales have been established to quantify the flow properties in each
of these flow regimes. The numerical simulation has verified the scaling results.
Gravity waves in a circular well
Authors: MILES JOHN
Published: July 2002

The natural frequencies of gravity waves in a circular well that is bounded above by
a free surface and below by a semi-infinite reservoir are approximated by neglecting
the off-diagonal terms of the characteristic determinant (single-mode approximation)
and invoking the known results for an aperture in a half-space (well of zero depth).
A parallel argument yields the corresponding results for a two-dimensional well (a
slot). Comparison with Molin's (2001) numerical results for a slot suggests that the
error in the single-mode approximation is [lsim ] 1%.
Scalar probability density function and fine
structure in uniformly sheared turbulence
Authors: FERCHICHI M. , TAVOULARIS S.
Published: July 2002

This study is an experimental investigation of the probability density function (p.d.f.)
and the fine structure of temperature fluctuations in uniformly sheared turbulence with
a passively introduced uniform mean temperature gradient. The shear parameter was
relatively large, resulting in vigorous turbulence production and a total mean strain
up to 23. The turbulence Reynolds number was up to 253. The scalar fluctuations
grew in a self-similar fashion and at the same exponential rate as the turbulence
stresses, in conformity with predictions based on an analytical solution of the scalar
variance equation. Analytical considerations as well as measurements demonstrate
that the scalar p.d.f. is essentially Gaussian and that the scalar–velocity joint p.d.f.
is essentially jointly Gaussian, with the conditional expectations of the velocity
fluctuations linearly dependent on the scalar value. Joint statistics of the scalar and
its dissipation rate indicate a statistical independence of the two parameters. The
fine structure of the scalar was invoked from statistics of derivatives and differences
of the scalar, in both the streamwise and transverse directions. Probability density
functions of scalar derivatives and differences in the dissipative and the inertial
ranges were strongly non-Gaussian and skewed, displaying flared, asymmetric tails.
All measurements point to a highly intermittent scalar fine structure, even more
intermittent than the fine structure of the turbulent velocity.
Riemann wave description of erosional
dam-break flows
Authors: FRACCAROLLO L. , CAPART H.
Published: July 2002

This work examines the sudden erosional flow initiated by the release of a dam-break
wave over a loose sediment bed. Extended shallow-water equations are formulated to
describe the development of the surge. Accounting for bed material inertia, a transport
layer of finite thickness is introduced, and a sharp interface view of the
morphodynamic boundary is adopted. Approximations are sought for an intermediate range
of wave evolution, in which equilibration of the sediment load can be assumed
instantaneous but momentum loss due to bed friction has not yet been felt. The resulting
homogeneous hyperbolic equations are mathematically tractable using the Riemann
techniques of gas dynamics. Dam-break initial conditions give rise to self-similar flow
profiles. The wave structure features piecewise constant states, two smoothly varied
simple waves, and a special type of shock: an erosional bore forming at the forefront
of the wave. Profiles are constructed through a semi-analytical procedure, yielding
a geomorphic generalization of the Stoker solution for dam-break waves over rigid
bed. For most flow properties, the predictions of the theoretical treatment compare
favourably with experimental tests visualized using particle imaging techniques.
Pipe flow measurements over a wide range of
Reynolds numbers using liquid helium and
various gases
Authors: SWANSON CHRIS J. , JULIAN BRIAN , IHAS GARY G. , DONNELLY RUSSELL J.
Published: July 2002

We demonstrate that an unusually small pipe flow apparatus using both liquid helium
and room temperature gases can span an enormous range of Reynolds numbers. This
paper describes the construction and operation of the apparatus in some detail. A wide
range of Reynolds numbers is an advantage in any experiment seeking to establish
scaling laws. This experiment also adds to evidence already in hand that the normal
phase of liquid helium is a Navier–Stokes fluid. Finally, we explore recent questions
concerning the influence of molecular motions on the transition to turbulence (Muriel
1998) and are unable to observe any influence.
Douze noms pour une main: nouveaux regards sur Judas à partir de Lc 22.21–2
Authors: CLIVAZ CLAIRE
Published: July 2002

Les données lucaniennes viennent remettre en question les lectures du personnage de Judas qui cherchent à le déculpabiliser, voire à le déresponsabiliser, pour en faire un ami de Jésus. Le présent article se propose d'utiliser l'analyse narrative pour étudier la personnification de Judas dans la séquence narrative de Lc 22.1–62, en lisant notamment Lc 22.21–2 dans son contexte. Il en résulte la mise en évidence de la dimension symbolique du personnage de Judas: cette dimension ouvre à la perception d'une anthropologie ouverte et risquée dans l'œuvre de Luc.
‘I want to go!’ How older people in Ghana look forward to death
Authors: VAN DER GEEST SJAAK
Published: July 2002

Older people in a rural Ghanaian community indicated that they look forward to death. Traditional ideas of ancestorhood, reincarnation and modern Christian beliefs about life after death had little influence on their resignation. Images of a possible ‘hereafter’ hardly existed. Agnosticism – in a religious guise – prevailed. They saw death foremost as a welcome rest after a long and strenuous life. Their readiness for death did not, however, include an acceptance of euthanasia. Both the young and the old held the view that life and death are and should remain in God's hands. This article is based on anthropological fieldwork in the rural town of Kwahu-Tafo in southern Ghana.
British government policy and the concentration of ownership in long-term care provision
Authors: HOLDEN CHRIS
Published: July 2002

Most long-term care for older people in the UK has been provided by independent organisations since the 1980s. This article draws on interviews with various stakeholders in the sector, as well as secondary sources. The evidence shows that government policies in the areas of funding, regulation and the labour market are facilitating the concentration of long-term care provision. Three areas of related concern are identified: firstly, the effects of increased ownership transfers; secondly, issues relating to standardisation; and thirdly, the possibility of a decline in the quality of care if local monopolies emerge. It is concluded that government regulation must be concerned with the structure of the market, as well as the conditions within care homes, if the interests of residents are to be protected.
Authenticity as authentication
Authors: Moore Allan
Published: July 2002

This article argues for the prematurity of any dismissal of the notion of authenticity as meaningful within popular music discourse. It synthesises a range of views as to how authenticity is constructed, and offers a tri-partite typology dependent on asking who, rather than what, is being authenticated. It focuses on rock and folk genres, but also argues that the generic nature of the typology makes it applicable to any other genre wherein listeners are concerned to ask whether a musical utterance can be construed as sincere.
Fuzzy continuous gain scheduled H∞ control based on Taylor series
fitting for robotic manipulators
Authors: Yu Zhongwei , Chen Huitang , Woo Peng-Yung
Published: July 2002

A new approach to the design of a fuzzy continuous gain scheduled H∞ controller based on Taylor series fitting for n-joint rigid robotic manipulators, which guarantees satisfactory dynamic characteristics in the whole movement range, is presented. This scheme combines the gain scheduled H∞ theory with the Linear Matrix Inequalities (LMI) approach to design a continuous gain scheduled H∞ controller, which is applicable to systems with fast state variations so that the deficiency of the coventional gain scheduled controllers is overcome, with the use of Taylor series fitting. Fuzzy control is then incorporated so that the design controller possesses the characteristics of a fast response for large errors and a well-damped response for small errors. The system thus always has a good dynamic performance along with the variations of the system states. Simulations and experiments demonstrate the effectiveness of the designed controller.
A comparison of bird richness, abundance and trophic organization in forests of Ecuador and Denmark: are high-altitude Andean forests temperate or tropical?
Authors: Poulsen Bent Otto
Published: July 2002

The fact that certain climatic variables are similar in high-latitude temperate zones and at high-altitude sites in the tropics, has led to assumptions about ecologically equivalent situations. The altitudinal differences between two data sets obtained in forests in temperate Denmark at sea level and in tropical Ecuador at 3000–3350 m above sea level provided a comparison suitable for examining whether high-altitude Andean forests are temperate or tropical from the standpoint of avian richness, abundance and trophic organization. Sampling methods at the two locations were similar. The Ecuadorian high-altitude sites were found to be significantly more species-rich than Danish temperate sites at all spatial scales studied (from point census to 10 km2). Additionally, species–area curves from the two countries displayed positive correlations, as expected, but with different rates of increase. The high-altitude Andean curve demonstrated a higher rate of increase causing the two curves to separate widely as more area was added. This means that when increasing areas are considered, proportionately more species squeeze into the Ecuadorian high-altitude forest landscape than do into the temperate Danish forest landscape. Corresponding to the data on richness, bird abundance was significantly higher at the Ecuadorian sites than at the Danish ones. The analysis of rank–abundance plots from Denmark and Ecuador throws light on the organization of bird species and abundance. The majority of communities in both countries fitted both the log-series and the log-normal models, making statistical distinction impossible. However, a visual inspection of the rank-ordered abundance distributions demonstrated that the Danish communities, in contrast to the Ecuadorian ones, had dominant species with relatively higher abundance, had more species with intermediate abundance, and had fewer species ‘rare by abundance’. Some major food resources (especially fruit and nectar) exploited in high-altitude sites of Ecuador were not reliably available in temperate Denmark leading also to differences in the distribution of bird species within six major trophic categories. In conclusion, the ecological characteristics of birds of the high Andes apparently are similar to those of the tropical and tropical lower montane sites (increased richness and abundance, similar organization of richness and abundance, similar additional trophic categories, similar clutch sizes), and not to those of the high- and low-latitude temperate sites.
On the highest Lyubeznik number
Authors: KAWASAKI KEN-ICHIROH
Published: July 2002

In this paper, we will prove that the highest Lyubeznik number λd,d(A) is one if
A is a Cohen–Macaualy local ring containing a field, where d is the dimension of A.
A sociological interpretation of the COLREGS
Authors: Belcher Phil
Published: July 2002

This paper discusses issues relating to the practical application of the collision avoidance regulations (COLREGS) from the sociological viewpoint that rules are always contingent, defeasible and that no rule can exhaustively specify the conditions of its use. It is proposed that, due to the inherent nature of rules, the only way successfully to manage collision risks at sea, is physically to separate opposing traffic flows, so as to remove the interpretative and mutually co-ordinating factors from the COLREGS.
Saltmarshes in a time of change
Authors: Adam Paul
Published: July 2002

Saltmarshes are a major, widely distributed, intertidal habitat. They are dynamic systems, responding to changing environmental conditions. For centuries, saltmarshes have been subject to modification or destruction because of human activity. In this review, the range of factors influencing the survival of saltmarshes is discussed. Of critical importance are changes in relative sea level and in tidal range. Relative sea level is affected by changes in absolute sea level, changes in land level and the capacity of saltmarshes to accumulate and retain sediment. Many saltmarshes are starved of sediment because of catchment modification and coastal engineering, or exposed to erosive forces, which may be of natural origin or reflect human interference. The geographical distribution of individual saltmarsh species reflects climate, so that global climatic change will be reflected by changes in distribution and abundance of species, although the rate of change in communities dominated by perennial plants is difficult to predict. Humans have the ability to create impacts on saltmarshes at a range of scales from individual sites to globally. Pressures on the environment created by the continued increase in the human population, particularly in developing tropical countries, and the likely consequences of the enhanced greenhouse effect on both temperature and sea level give rise to particular concerns. Given the concentration of population growth and development in the coastal zone, and the potential sensitivity of saltmarsh to change in sea level, it is timely to review the present state of saltmarshes and to assess the likelihood of changes in the near (25 years) future. By 2025, global sea level rise and warming will have impacts on saltmarshes. However, the most extensive changes are likely to be the direct result of human actions at local or regional scales. Despite increasing recognition of the ecological value of saltmarsh, major projects involving loss of saltmarshes but deemed to be in the public interest will be approved. Pressures are likely to be particularly severe in the tropics, where very little is known about saltmarshes. At the local scale the cumulative impacts of activities, which individually have minor effects, may be considerable. Managers of saltmarshes will be faced with difficult choices including questions as to whether traditional uses should be retained, whether invasive alien species or native species increasing in abundance should be controlled, whether planned retreat is an appropriate response to rising relative sea level or whether measures can be taken to reduce erosion. Decisions will need to take into account social and economic as well as ecological concerns.
Phenotypic plasticity of anuran larvae: environmental variables influence body shape and oral morphology in Rana temporaria tadpoles
Authors: Vences Miguel , Puente Marta , Nieto Sandra , Vieites David R.
Published: July 2002

Environmental variables shaped the morphology of tadpoles of the common frog, Rana temporaria, in various ways at the Pyrenean locality Circo de Piedrafita. Examining only specimens in similar developmental stages, those from small ponds (with higher temperature and higher tadpole density) had lower growth rates, lower relative tail height, lower relative body width and fewer labial keratodonts and keratodont rows. The variation in keratodonts may have been caused by heterochrony related to the slower growth rate. The number of lingual papillae also differed between ponds but was not related to pond size. Higher predator densities caused a higher percentage of damaged tails and a lower relative tail length in specimens with apparently intact tails, probably as a result of incomplete regeneration after mutilations earlier in development.
Spatial and social organization of a carnivorous marsupial Dasyurus hallucatus (Marsupialia: Dasyuridae)
Authors: Oakwood Meri
Published: July 2002

The northern quoll Dasyurus hallucatus is a sexually dimorphic carnivorous marsupial found in northern Australia. Despite males weighing up to 1120 g, in at least some populations all males die after mating. Radio‐tracking and live‐trapping at a lowland savanna site in Kakadu National Park indicated that females occupied home ranges averaging 35 ha with intra‐sexually exclusive denning areas. There was some overlap of foraging ranges when the density was 3–4 females/km2, but no overlap during periods of lower population density (1–2 females/km2). Male home‐range size may be similar to females before the mating season, but expands during the mating season to > 100 ha to overlap extensively with several female ranges and numerous other male ranges. Despite this range overlap, both sexes were solitary. Even during the mating period, males denned on average 0.27 km from females during the day. During the mating period, each female was visited by at least one to four males per night. During this period, the increase in scat deposition in prominent positions in the landscape and the simultaneous increase in sternal gland activity of the males suggest the importance of olfactory communication to advertise the presence and sexual status of individuals. Males adopted a roving strategy, regularly visiting several widely spaced females in rapid succession, presumably to monitor the onset of oestrus. This intense physical effort during the mating period is likely to be a major contributor to the physiological decline of the males and subsequent die‐off after the mating period. The marked sexual dimorphism of D. hallucatus may be the result of selection for larger, wider‐ranging males in a promiscuous mating system and for energetically efficient smaller females, as females rear the young alone.
Sexual size dimorphism in Tengmalm's owl (Aegolius funereus) on autumn migration
Authors: Hipkiss Tim
Published: July 2002

Sexual size dimorphism in Tengmalm's owls Aegolius funereus outside the breeding season was investigated by trapping owls on migration during autumn. Owls were accurately sexed using PCR‐based molecular techniques. Females were 4% heavier than males, but were c. 30% lighter than during the breeding season, when they carry large fat deposits and can be twice as heavy as males. Thus sexual mass dimorphism outside the breeding season was substantially lower than reported previously for the breeding season in this species. Females also had 2.5% longer wings and tail than males, but there was no difference in wing‐loading, indicating that flight proficiency was similar between the sexes. Though the degree of sexual size dimorphism is small, large female size might be an adaptation for accumulating larger fat reserves, while smaller male size allows more efficient flight and hunting. This study highlights the importance of investigating sexual size dimorphism in owls outside the breeding season to avoid overestimation of female body mass.
Landscape structure and food supply affect eagle owl (Bubo bubo) density and breeding performance: a case of intra‐population heterogeneity
Authors: Penteriani Vincenzo , Gallardo Max , Roche Philip
Published: July 2002

During the 20th century, Mediterranean landscapes underwent extensive changes. In particular, decreasing grazing pressure combined with abandonment of agricultural uplands favoured the development of Mediterranean forests with a corresponding reduction of open habitats and landscape diversity. In some parts of the Mediterranean basin, including our study area, the reduction of open landscapes took place at the same time as a rapid decline in rabbits as a result of myxomatosis. This study assesses the impact of past changes in landscape and rabbit density on the density and the breeding performance of the eagle owl Bubo bubo, one of the largest predators of Mediterranean ecosystems. Eagle owl density, nest site structure and composition at the landscape level, diet and fecundity of 35 eagle owl nesting territories was analysed for 27 years. The study area is characterized by two distinct areas, the border of the massif and the interior, in which past changes acted differently. Eagle owls in the interior were simultaneously affected by the loss of rabbits, a shift to smaller prey, and by open areas reverting to forest. All of these factors reduced the foraging efficiency of the owls. When myxomatosis decimated the rabbit population, owls in the border area switched to other mammals, birds and fish, whereas in the interior, alternative prey were less abundant. The main impacts of reduced prey availability and landscape diversity on interior pairs were: (1) lower density of breeding pairs; (2) lower diversity in landscape structure and closer habitats; (3) lower richness and diversity in the diet; (4) later egg‐laying dates; (5) lower productivity.
Home ranges, spatial movements and habitat associations of the Philippine tarsier (Tarsius syrichta) in Corella, Bohol
Authors: Neri‐Arboleda I. , Stott P. , Arboleda N. P.
Published: July 2002

Home ranges, spatial movements and patterns of habitat use were determined during a radio‐tracking study on four male and six female Philippine tarsier Tarsius syrichta in Corella, Bohol, from early March to October 1999. This was the first radio‐tracking study of the Philippine tarsier that included both breeding adult males and females. Home ranges averaged 6.45 ha for males and 2.45 ha for females (MCP and Kernel 95%), allowing for a density of 16 male and 41 female tarsiers per 100 ha. The habitats are primarily located in secondary lowland rainforest in early to mid succession stage, but individual tarsiers readily traversed open grass areas to move between forest patches. However, the tarsiers avoided adjacent residential areas, clearings and agricultural plantation, even if the last two were found enclosed in home‐range polygons. The home range of one male overlapped extensively with that of one female and to a lesser extent with a second female. Home ranges of males showed little overlap (2.71%) and the same was observed among the females (3.35%). Nightly travel distance averaged 1636 m for males and 1119 m for females. Individuals were observed to forage and sleep solitarily. The tarsiers form groups of one adult male and one or two adult females and their offspring.
Wood and Crop Theft in Rural Herefordshire, 1800–60
Authors: SHAKESHEFF TIM
Published: July 2002

Lacking the glamour of poaching or the undertones of protest associated with incendiarism or animal maiming, the more petty rural crimes have been largely ignored. This paper examines the motivation, nature and criminal administration of two under-researched crimes, wood and crop theft. It will be suggested that while the theft of wood and crops was almost wholly the crime of the rural poor, it may have been committed within a wider realm of social protest.
‘Making drain tiles a “home manufacture”’: Agricultural Consumers and the Social Construction of Clayworking Technology in the 1840s
Authors: WATT KATHLEEN
Published: July 2002

During the nineteenth century newly invented clayworking machinery offered potential solutions to production problems in the British brickmaking industry. Three different mechanical brickmaking processes were available, but a combination of design imperfections and restrictions imposed by the excise duties on bricks discouraged their adoption in ordinary brickyards for many decades. This posed a serious dilemma for machine inventors. Without an opportunity to test machinery in brickmaking situations, they were unable to correct defects and produce implements that were clearly superior to hand brickmaking methods. For as long as brickmakers rejected mechanisation, the technical development of machinery was effectively halted. A breakthrough occurred in the 1840s when a lucrative new market emerged for machines capable of manufacturing large quantities of drainage pipes and tiles in rural locations. The exhibitions and implement trials at meetings of the Royal Agricultural Society of England were a decisive factor in the continuing technical development of clayworking machinery. Agricultural consumers, through debate, evaluation and negotiation with machine makers, ultimately determined the success of one mechanical clayworking process over others, and established the direction of future technological change in the brickmaking industry.
A Contribution by al-Qūhī to Geometrical Analysis
Authors: Abgrall Philippe
Published: July 2002

The development of geometrical analysis in the 10th century was partly inspired by the reception of the works of Apollonius, which Arab mathematicians translated as early as the preceding century. Al-Qūhī contributed to this development by writing several collections of problems dealing with Apollonian themes and solved by the method of analysis; however, it seems that they do not all occupy the same place in his work. The author gives here the edition, translation, and mathematical commentary of a short work, entitled The determination of two straight lines from a point along a known angle, which presents the particularity of providing problems as geometrical lemmas to other studies. Indeed, al-Qūhī uses two of these lemmas in more complex constructions which belong to his Treatise on the art of the astrolabe. In this same treatise on the astrolabe, as well as in his Treatise on the perfect compass, this scholar also uses as lemmas several problems solved in another of his works, entitled The generation of points on straight lines according to ratios of which the terms are surfaces. This work is unfortunately lost, and all that remains of it are the traces which subsist in other treatises in which it has been used. This study seems to be necessary if one wishes to understand the organization of the work of al-Qūhī, a mathematician of the first rank who was representative of his time.
Mechanisms and regulations of endometrial angiogenesis
Authors: Gargett C , Weston G , Rogers PAW
Published: July 2002

Angiogenesis is defined as the formation of new blood vessels from the existing vasculature. Angiogenesis occurs regularly in the endometrium throughout the reproductive life of females as part of the rapid growth and regression of this tissue that occurs during the menstrual cycle. It is now clearly evident that angiogenesis plays a key role in reproductive processes such as embryo implantation, placentation, endometrial regeneration after menstruation, and in the ovary during folliculogenesis and corpus luteum formation. Given the complexity and continual change of the endometrial milieu, it seems highly likely that aberrations in the angiogenic process may contribute to various disorders, including endometrial cancer, endometriosis, menorrhagia and breakthrough bleeding – all significant and common gynaecological pathologies. This review provides an update on the mechanisms and regulation of endometrial angiogenesis, with particular reference to the role of angiogenesis in implantation and placentation, as well as two endometrial pathologies – endometriosis and breakthrough bleeding.
Subdivision schemes in geometric modelling
Authors: Dyn Nira , Levin David
Published: July 2002

Subdivision schemes are efficient computational methods for the design and
representation of 3D surfaces of arbitrary topology. They are also a tool for
the generation of refinable functions, which are instrumental in the construction
of wavelets. This paper presents various flavours of subdivision, seasoned
by the personal viewpoint of the authors, which is mainly concerned with
geometric modelling. Our starting point is the general setting of scalar multivariate
nonstationary schemes on regular grids. We also briefly review other
classes of schemes, such as schemes on general nets, matrix schemes, non-uniform
schemes and nonlinear schemes. Different representations of subdivision
schemes, and several tools for the analysis of convergence, smoothness
and approximation order are discussed, followed by explanatory examples.
Progesterone treatment of boar spermatozoa improves male pronuclear formation after intracytoplasmic sperm injection into porcine oocytes
Authors: Katayama Mike , Miyano Takashi , Miyake Masashi , Kato Seishiro
Published: July 2002

Boar spermatozoa were prepared for intracytoplasmic sperm injection (ICSI) by two different treatments to facilitate sperm chromatin decondensation and improve fertilisation rates after ICSI in pigs: spermatozoa were either frozen and thawed without cryoprotectants, or treated with progesterone. Morphological changes of the sperm heads after the treatments were examined and then the activation of oocytes and the transformation of the sperm nucleus following ICSI were assessed. After freezing and thawing, the plasma membrane and acrosomal contents over the apical region of sperm head were lost in all the spermatozoa. Following treatment with 1 mg/ml progesterone, the acrosome reaction was induced in 61% of spermatozoa. After injection of three types of spermatozoa, non-treated spermatozoa and progesterone-treated (i.e. acrosome-reacted) spermatozoa induced oocyte activation, but frozen-thawed spermatozoa induced oocyte activation at a significantly lower rate. Sixty-two per cent of sperm heads remained orcein-negative for 6 h, however, resulting in delayed sperm chromatin decondensation and low male pronuclear formation in the oocytes injected with a non-treated spermatazoon. Since the treatments of freezing and thawing and progesterone for spermatozoa accelerated the initial change in sperm chromatin and the latter treatment induced oocyte activation earlier, it is considered that the delay in oocyte activation and decondensation of sperm chromatin after injection of non-treated spermatozoa is caused by the existence of the sperm plasma membrane. These results show that progesterone treatment efficiently induces the acrosome reaction in boar spermatozoa without destroying their potency for oocyte activation, and the induction of the acrosome reaction results in the promotion of male pronuclear formation after ICSI.
Chromatin and microtubule organisation in maturing and pre-activated porcine oocytes following intracytoplasmic sperm injection
Authors: Kim Bong-Ki , Lee Youn-Jeong , Cui Xiang-Shun , Kim Nam-Hyung
Published: July 2002

Chromatin and microtubule organisation was determined in maturing and activated porcine oocytes following intracytoplasmic sperm injection in order to obtain insights into the nature of sperm chromatin decondensation and microtubule nucleation activity. Sperm chromatin was slightly decondensed at 8 h following injection into germinal vesicle stage oocytes. Sperm-derived microtubules were not seen in these oocytes. Following injection into metaphase I (MI)-stage oocytes, sperm chromatin went to metaphase in most cases. A meiotic-like spindle was seen in the sperm metaphase chromatin. In a few MI-stage oocytes, sperm chromatin decondensed at 8 h after injection, and a small sperm aster was seen. Sperm injection into oocytes at 5 h following activation failed to yield pronuclear formation. Maternally derived microtubules were organised near the female chromatin in these oocytes, and seemed to move condensed male chromatin closer to the female pronucleus. At 18 h after sperm injection into pre-activated oocytes, a condensed sperm nucleus was located in close proximity to the female pronucleus. These results suggest that the sperm nuclear decondensing activity and microtubule nucleation abilities of the male centrosome are cell cycle dependent. In the absence of a functional male centrosome, microtubules of female origin take over the role of microtubule nucleation for nuclear movement.
Immunohistochemical localisation of gp69/64 molecules in Xenopus egg envelopes in relation to their sperm binding activity
Authors: Kubo Hideo , Kotani Masaharu , Suzuki Hidenori , Yoshizaki Norio
Published: July 2002

A monoclonal antibody (6964M) was generated against the envelope component gp69/64 of Xenopus laevis eggs. On indirect immunofluorescence using this antibody, the positive reaction was seen on the surface of both vitelline envelope (VE) and coelomic envelope (CE). On immunoelectron microscopy, gp69/64 was preferentially distributed on the thick bundles forming the edge of the tunnel openings on CE, and this distribution pattern was fundamentally inherited by VE. Counting the number of immunogold particles indicated that VE has about twice as many particles as CE, with a 3-4 times higher density at the animal pole than vegetal pole. The number of sperm bound to CE was small, being approximately one-twentieth of the number of sperm bound to VE. An extremely small number of sperm (< 2 per animal hemisphere) was found to bind to VE* of activated eggs as a background. The sperm binding to CE was inhibited by pretreatment of the envelopes with 6964M or in the presence of purified gp69/64 from VE on insemination, confirming that sperm binding is mediated by gp69/64 exposed on the CE surface. In spite of at most a 2-fold increase in the amount of exposed gp69/64, the sperm binding increased about 20-fold upon CE-to-VE conversion, suggesting that the increase in the amount of exposed gp69/64 is itself insufficient to explain the increase in the number of bound sperm.