bluuebunny/crossref_metadata_2025 huggingface dataset:
Herramientas para simulación de matrices productivas óptimas del Ecuador
Authors: Flores Tapia Carlos Ernesto , Flores Cevallos Karla Lissette
Published: June 2017

El gobierno ecuatoriano presidido por el Eco. Rafael Correa impulsa el cambio de la matriz productiva como una política de Estado para superar el modelo económico primario.  Prioriza 14 sectores y 5 industrias estratégicos para modelar el cambio. La matriz propuesta por el gobierno no se sustenta en métodos cuantitativos que permitan calcular e interpretar las interdependencias de los diversos sectores de la economía; sino en apreciaciones subjetivas relacionadas con su posible potencial de mercado. El estudio contempla el análisis de la percepción de los sectores productivos de la provincia de Tungurahua con respecto a la priorización propuesta por el gobierno y el desarrollo de herramientas informáticas integradas en el “Simulador de la Matriz Insumo Producto” que permite calcular el impacto económico de cada rama del Sistema de Clasificación Industrial de América del Norte 2013 (SCIAN) en la economía total, en la propia rama y en otras ramas afectadas; y evaluar las distintas alternativas de matrices óptimas aplicando la Matriz de Leontief.  Se recopila información existente en bases de datos gubernamentales y se establecen los criterios de análisis que permiten procesar la información con algoritmos matemáticos que vinculan herramientas informáticas. Finalmente se está en condiciones de proyectar el impacto de los resultados a nivel de producción, remuneraciones y puestos de trabajo, inducidos por cambios en alguno de los componentes de la demanda final.El estudio resulta prioritario porque aporta una visión estratégica para la toma de decisiones de la inversión pública y privada en el Ecuador sustentada en herramientas técnicas cuantitativas.
Developing a Mathematics Module for Students with Intellectual Disability in Higher Education
Authors: Prendergast Mark , Spassiani Natasha A , Roche Joseph
Published: June 2017

Individuals with intellectual disability (ID) have largely been excluded from accessing all levels of education and participating in college life. Fortunately, academic institutions around the world are slowly beginning to examine how they can support equal citizenship of individuals with ID within their community. In Ireland, one university has recently accredited an innovative higher education programme for college students with intellectual disabilities. One of the emergent modules focuses on mathematics and recognises the importance of developing students’ numeracy skills in order to confidently navigate today’s society. Despite the increased emphasis on general mathematics education, the authors found there to be a dearth of research regarding the development of such a module for students with ID. This paper describes the design and development of the mathematics module and also details its piloting and evaluation with a cohort of students with ID who were enrolled in a higher education course in an Irish university.
Reviewer Acknowledgements for International Journal of Statistics and Probability, Vol. 3, No. 4
Authors: Smith Wendy
Published: June 2017

International Journal of Statistics and Probability wishes to acknowledge the following individuals for their assistance with peer review of manuscripts for this issue. Their help and contributions in maintaining the quality of the journal is greatly appreciated. Many authors, regardless of whether International Journal of Statistics and Probability publishes their work, appreciate the helpful feedback provided by the reviewers. Reviewers for Volume 3, Number 4 Abdullah A. SMADI Anna Grana' Bibi Abdelouahab Carla J. Thompson Carolyn Huston Chin-Shang Li Ehsan Karim Enayetur Raheem Ivair R. Silva Jacek Bialek Jorge M. Mendes Kouji Yamamoto Lishu Li Michela Ottobre Philip Westgate Sajid Ali Sohair F. Higazi Vyacheslav Abramov Yichuan Zhao Zaixing Li   Wendy Smith On behalf of, The Editorial Board of International Journal of Statistics and Probability Canadian Center of Science and Education
Soil and Rhizosphere Bacterial Diversity in Maize Agro- Ecosystem
Authors: Federici Rodriguez Maria Teresa , Bajsa Valverde Natalia , Lagurara Paula , Revale Santiago , Marcondes de Souza Jackson Antonio , Dalla Rizza Vilaro Marco
Published: June 2017

Management practices used in maize production have an impact on soil agro- ecosystems where different microbial communities coexist. Soil inhabiting bacteria are numerous and diverse, but we know very little about their ecological distribution. Here we analyzed the bacterial community diversity in the rhizosphere of two transgenic maize cultivars, in agricultural soil before sowing and in non-cultivated soil in an experimental site in the south region of Uruguay. We followed two culture-independent methods: DGGE (denaturing gradient gel electrophoresis) and 454-pyrosequencing of 16S rRNA gene amplicon. Through pyrosequencing, the three environments analyzed presented differences in terms of bacterial composition. However, no differences were found in the relative abundance of the ten most represented phyla in the rhizosphere of the two cultivars at different phenological stages. We found significant differences of Bacteroidetes, Gemmatimonadetes, Planctomycetes, Proteobacteria and Verrucomicrobia phyla when comparing agricultural and non-cultivated soils, as well as a significant enrichment of members of the phylum Gemmatimonadetes in all rhizosphere samples compared to soil. Through DGGE analysis we evidenced that maize rhizosphere bacterial communities changed at different phenological stages in both cultivars. We also provided baseline information about bacterial specific taxa within maize agro- ecosystem for further evaluation of possible rhizosphere bacterial community shifts of genetically modified maize cultivars under different management practices.
Entrepreneurial Parties: A Basic Conceptual Framework
Authors: Hloušek Vít , Kopeček Lubomír
Published: June 2017

The paper offers a conceptual framework to investigate the phenomenon of entrepreneurial parties in the countries of East-Central Europe. The authors evaluate existing concepts related to increasing interdependence of party politics and the business sector, such as business-firm parties. These concepts are typically much too bound to a particular example of historically emerging entrepreneurial party and therefore the paper offers a more general concept of entrepreneurial party. The concept is based on five basic features: (1) the central role of the leader and his private initiative, (2) the party as a personal vehicle, (3) the crucial formative influence of a leader over the political project. Two other features are related to the social and institutional un-rootedness of the entrepreneurial party which is neither a product of (4) a promoter/sponsor organisation or social movement, nor it is an outcome of (5) a parliamentary split or emergence of a new faction.
Editor's Note: CAL: The Perfect Marriage
Authors: Verbeten Sharon
Published: June 2017

Fifteen years ago, when I was working full-time as an editor in a small town in Wisconsin, a library friend of mine passed along a job opening to me. Seems ALSC was looking for an editor for its division magazine to be called Children and Libraries. The friend, aware that I had a library degree, thought the job seemed right up my alley.
Now Playing . . .: Using Podcasts and Kidcasts in the Library
Authors: Felde Kitty , Rogers Pamela
Published: June 2017

Podcasts created for kids, and often by kids, are quickly growing in number, scope, and popularity. The list of recommended podcasts on Zooglobble, a kids’ music and audio review site, has grown to include almost eighty. And podcasts for kids, also called “kidcasts,” are not just for earphones and home speakers.Podcasts for kids are taking the stage. Ear Snacks, hosted by professional “kindie” (kid-indie) musicians, recently performed at the San Francisco Public Library and at San Francisco’s Recess Urban Recreation Center. Book Club for Kids tapes live shows at book festivals all across the eastern seaboard. The Secret Diaries of Tara Tremendous, superhero adventure stories produced by Wonkybot Studios, was even turned into a Broadway musical.
Pre-K Partnership: How One Library and One Public School Increased Parent Engagement
Authors: Aldrich Kristen Rocha
Published: June 2017

Pre-K seems to be the new kindergarten. Parents and caregivers are faced with increasing pressure to ensure their children are school ready.Every parent and caregiver possesses these skills; however, a little extra support and guidance can go a long way in a child’s literacy development. Pre-K is a great place for children to build and learn new literacy and social emotional skills. Teachers are there to help the families begin navigating the school system and to give their children the building blocks to become successful lifelong learners. However, this process begins long before a child enters school. Often, the first time children and families are exposed to these skills is at their local library, either through activities geared towards families or through partnerships with pre-K and daycare classrooms.
I Am Not Beyoncé: Tackling the Issue of Race Representation Head On
Authors: Elliott Zetta
Published: June 2017

On my last night of a six-day sojourn in the Twin Cities, I gave a reading at The Loft Literary Center and shared this statement made by a young Black woman, Ysa, whom I had met at Juxtaposition Arts earlier in the day.Ysa and two of her fellow artist-apprentices shared with me the creative process behind the impressive mural they recently painted on their block. My morning presentation at the arts center was sponsored by Umbra Search, a free digital platform that provided research assistance when the young women needed to study graphics from the Black Panther Party’s newspapers. The mural features a mother and child in the traditional sacred pose, but the child in this scene is female and these haloed figures have brown skin and Afros. Beams of light radiate outward, made up of hundreds of small black-and-white photographs of Black women who have made a contribution to the community as well as those who have lost a loved one to violence.
Using Social Media to Impart Early Literacy Tips to Parents
Authors: Bickford Jill
Published: June 2017

Libraries are constantly working to help parents prepare their children to be readers, and we’re aided, in part, by the Every Child Ready to Read (ECRR) parent education initiative.We are always looking for new ways to reach parents of young children and convey this accessible, practical, and applicable information. We impart tips during parent workshops and storytimes, and one-on-one during patron interactions, but how do we continue to reach them once they’ve left the building? How do we reach those caregivers who cannot regularly come to our libraries for a variety of reasons?
Math Counts Too! Promoting Family Engagement in Math Activities at Home
Authors: Zippert Erica L. , Diamant-Cohen Betsy , Goldsmith Annette Y.
Published: June 2017

Although librarians typically focus on language and literacy when planning children’s programs, research suggests that math skills are valuable too. Today, proficiency in math is an essential professional skill. Many careers involve math, and math classes act as gateways to attaining degrees in STEM fields.1 In our personal lives, math is used daily to manage household finances and make informed decisions about our health.2 Finally, math skills at school entry are strong predictors of later academic achievement in both math and reading.3 Therefore, math development should be considered an important part of children’s school readiness skills.
Morphological, Thermal and Electrical Properties of (PEO/PVP)/ Au Nanocomposite Before and After Gamma-Irradiation
Authors: Abdelrazek E.M. , Abdelghany A.M. , Badr S.I. , Morsi M.A.
Published: June 2017

Gold nanoparticles (Au NPs) have been successfully biosynthesized by Chenopodium murale (C. murale) leaf extract. Au NPs were incorporated within polyethylene oxide (PEO)/polyvinyl pyrrolidone (PVP) polymer blend by casting method. Scanning electron microscope (SEM), Differential scanning calorimetry (DSC), and DC electrical resistivity were used to investigate the morphological, thermal, and electrical properties of blend/Au nanocomposite before and after gamma-irradiation at different doses (1, 2, 3, 4 and 5 MR).SEM micrographs confirmed the dispersion of Au NPs within the polymeric matrix due to effect of irradiation process. DSC analysis showed that the thermal stability for irradiated samples was improved as compared with pure blend and its nanocomposite. DC measurements revealed nonlinear behavior for electrical resistivity versus temperature. The electrical resistivity values for blend/Au nanocopmosite and its high irradiated samples were less compared to pure blend.
Chronic lithium treatment elicits its antimanic effects via BDNF-TrkB dependent synaptic downscaling
Authors: Gideons Erinn S , Lin Pei-Yi , Mahgoub Melissa , Kavalali Ege T , Monteggia Lisa M
Published: June 2017

Lithium is widely used as a treatment for Bipolar Disorder although the molecular mechanisms that underlie its therapeutic effects are under debate. In this study, we show brain-derived neurotrophic factor (BDNF) is required for the antimanic-like effects of lithium but not the antidepressant-like effects in mice. We performed whole cell patch clamp recordings of hippocampal neurons to determine the impact of lithium on synaptic transmission that may underlie the behavioral effects. Lithium produced a significant decrease in α-amino-3-hydroxyl-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)-mediated miniature excitatory postsynaptic current (mEPSC) amplitudes due to postsynaptic homeostatic plasticity that was dependent on BDNF and its receptor tropomyosin receptor kinase B (TrkB). The decrease in AMPAR function was due to reduced surface expression of GluA1 subunits through dynamin-dependent endocytosis. Collectively, these findings demonstrate a requirement for BDNF in the antimanic action of lithium and identify enhanced dynamin-dependent endocytosis of AMPARs as a potential mechanism underlying the therapeutic effects of lithium.
Post-meiotic DNA double-strand breaks occur in Tetrahymena, and require Topoisomerase II and Spo11
Authors: Akematsu Takahiko , Fukuda Yasuhiro , Garg Jyoti , Fillingham Jeffrey S , Pearlman Ronald E , Loidl Josef
Published: June 2017

Based on observations of markers for DNA lesions, such as phosphorylated histone H2AX (γH2AX) and open DNA ends, it has been suggested that post-meiotic DNA double-strand breaks (PM-DSBs) enable chromatin remodeling during animal spermiogenesis. However, the existence of PM-DSBs is unconfirmed, and the mechanism responsible for their formation is unclear. Here, we report the first direct observation of programmed PM-DSBs via the electrophoretic separation of DSB-generated DNA fragments in the ciliate Tetrahymena thermophila. These PM-DSBs are accompanied by switching from a heterochromatic to euchromatic chromatin structure in the haploid pronucleus. Both a topoisomerase II paralog with exclusive pronuclear expression and Spo11 are prerequisites for PM-DSB induction. Reduced PM-DSB induction blocks euchromatin formation, characterized by histone H3K56 acetylation, leading to a failure in gametic nuclei production. We propose that PM-DSBs are responsible for histone replacement during the reprogramming of generative to undifferentiated progeny nuclei.
Optimizing plot size and shape for field experiments on terraces
Authors: Poultney R. , Riley J. , Webster R.
Published: July 2002

Two methods, namely combined plot analysis and integration of variograms, have been applied to investigate and compare plot-to-plot yields of intercropped millet (mean yield of about 1.9 t ha−1) and maize (mean yield 4.25 t ha−1) on terraces in Nepal. Combining plots diminishing the residual variance of millet from 0.52 (t/ha)2 of the original 1 m×1 m units to 0.08 (t/ha)2 for 4 m×4 m plots, the largest for which reliable estimates could be derived. The residual variance of maize declined from 4.91 (t/ha)2 of the original units to 0.61 (t/ha)2 for 4 m×4 m plots. Orientation was immaterial. The variogram for millet was isotropic and bounded with a
range of approximately 4 m. Within-plot variance calculated from the variogram
increased, and experimental error decreased, as the size of plots increased to this value, beyond which there was little gain. The variogram for maize was unbounded, and so gave no
‘natural' upper limit for plot size, that is, over the range studied, up to 6 m×6 m. It was also anisotropic with larger gradient in the direction from front to back of the terrace than along the contour. The reduction in residual
variance was greatest for narrow plots elongated in this direction. Formulae are provided from which to calculate from the variogram approximate residual variances for experiments of given area and size, shape, and orientation of plots. Its application gave similar results
to those from the combined plot analysis. Overall, the results from the two methods were consistent.
FARMER ACCEPTABILITY CRITERIA IN BREEDING COWPEA
Authors: KITCH L. W. , BOUKAR O. , ENDONDO C. , MURDOCK L. L.
Published: July 2002

Cowpea (Vigna unguiculata) farmers from diverse geographical areas in northern Cameroon selected breeding lines from on-station trials for their own fields and explained their reasons (criteria) for making the selections. The average selection intensity employed by farmers varied from 6 to 17% and was similar to that employed by plant breeders. Their selection criteria fell into three broad categories relating to yield, preference and quality, and labour, which were very consistent over years, locations and gender. Selection criteria were strongly influenced by market preferences, reflecting the increasing role of cowpea as a cash crop. Implications of these findings for breeding strategies and genetic resource conservation are discussed.
Optimal weighting of information in marker-assisted

selection
Authors: WHITTAKER J. C. , HALEY C. S. , THOMPSON R.
Published: July 2002

In crosses between inbred lines linear regression can be used to

estimate marker effects; these

marker effects then allow marker-assisted selection (MAS) for

quantitative traits. Weighting of

marker and phenotypic information in MAS requires estimation of genetic

variance associated

with the markers: the usual estimators are biased, resulting in too

much weight being placed on

marker information relative to phenotypic information. In this

paper we develop a cross-validation

method to remove this bias, and show by simulation that response to

selection using this method is

almost as high as that achieved using optimal weighting of marker

and phenotypic information.
Correlated responses to selection on body size in Drosophila
melanogaster
Authors: PARTRIDGE LINDA , LANGELAN ROSALIE , FOWLER KEVIN , ZWAAN BAS , FRENCH VERNON
Published: July 2002

Correlated responses to artificial selection on body size in Drosophila melanogaster were
investigated, to determine how the changes in size were produced during development. Selection
for increased thorax length was associated with an increase in larval development time, an
extended growth period, no change in growth rate, and an increased critical larval weight for
pupariation. Selection for reduced thorax length was associated with reduced growth rate, no
change in duration of larval development and a reduced critical larval weight for pupariation. In
both lines selected for thorax length and lines selected for wing area, total body size changed in
the same direction as the artificially selected trait. In large selection lines of both types, the
increase in size was achieved almost entirely by an increase in cell number, while in the small lines
the decrease in size was achieved predominantly by reduced cell size, and also by a reduction in
cell number. The implications of the results for evolutionary-genetic change in body size in nature
are discussed.
DISRAELI AND ENGLAND
Authors: PARRY J . P.
Published: July 2002

This article questions the dominant historiographical approaches to understanding the
career of Benjamin Disraeli, which view him either as more opportunistic than most of his political
contemporaries or as more ‘continental’ in his outlook. It emphasizes his determination to understand
English history and values, and argues that a desire to defend and realize his conception of England
gave his career coherence. He saw himself as a foe of dangerous cosmopolitan ideas that were damaging
the national character and creating social disharmony. This allowed him to cast all his major
political initiatives in a heroic, elitist yet restorative light. He conceived those initiatives as a response
to the damage inflicted by the domestic and international crises of the 1830s and 1840s. Indeed it is
arguable that as a result Disraeli's political strategy in later life was in some ways both quixotic and
outdated.
Migration Systems in Southern Portugal: Regional and Transatlantic Circuits of Labor Migration in the Algarve (Eighteenth–Twentieth Centuries)
Authors: Borges Marcelo J.
Published: July 2002

This article applies a systems approach to the analysis of multiple circuits of labor migration that emerged in the Algarve, southern Portugal, from the late eighteenth century to the mid 1900s, and their connections. Over time Algarvian migrants participated in three main systems of migration: internal migration and migration to southern Spain and Gibraltar, transatlantic migration to the Americas and Africa – especially to Argentina – and migration to northern Europe. Rather than an abrupt break with a sedentary past, the article shows how the beginnings of transatlantic migration at the turn of the century were the result of modification and adaptation of existing strategies of labor migration.
THE GANDA ON LAKE VICTORIA: A NINETEENTH-
CENTURY EAST AFRICAN IMPERIALISM
Authors: REID RICHARD
Published: July 2002

The examination of the growth of canoe transport in Buganda in
the
nineteenth century is an aspect of the kingdom's history that has
received
little serious consideration to date. This paper focuses on the ways in
which
the canoe fleet, especially from the 1840s, was systematically developed
and
utilized in the extension of Ganda power and influence in the Lake Victoria

region. The need to protect and promote commerce was one of the driving

forces behind Buganda's diplomatic, military and technological policies
in
the second half of the nineteenth century. This was consistent with
objectives of the kingdom that had endured since around the middle of the

sixteenth century, although the scale of these objectives had expanded
along
with the kingdom's horizons. Yet recognition of this basic continuity
should
not detract from our appreciation of the degree to which the Ganda
innovated to meet the challenges of long-distance trade, as well as the

challenges to their control of the external environment. The presence of

Ganda at Tabora, on the southern shore of Lake Victoria, and even at
Zanzibar itself is indicative of the alacrity with which Kabaka
Suna (c.
1830–56) and Kabaka Mutesa (1856–84) seized their
opportunities and
attempted to secure conditions perceived to be favourable to the ‘national

interest’ far beyond territorial borders. Yet Ganda also failed to
realize the
full military potential of their canoes. Despite their considerable efforts,
the
success of the naval endeavour was never without qualifications, and it
is one
of the primary aims of this paper to analyze these deficiencies.
Cumulative effects of nitrogen application to winter

wheat at Ropsley, UK, from 1978 to 1990
Authors: BHOGAL A. , YOUNG S. D. , SYLVESTER-BRADLEY R. , O'DONNELL F. M. , RALPH R. L.
Published: July 2002

In 1977, a four-course rotation was set up at Ropsley (UK) to study

crop response to eight rates of nitrogen application (35–265 kg

ha−1). This rotation continued until 1990 when continuous
winter

wheat was introduced. Results from 1978 to 1990 provide an opportunity
to

study the initial phase

of cumulative effects from different rates of N fertilizer application
on

the recovery of N by cereals and the retention of N in the soil.

From 1978 to 1990, considerable variation in the recovery of nitrogen

by winter wheat was

observed. Neither rainfall nor drainage, as indicators of possible

denitrification or leaching losses,

provided a useful explanation for this, possibly because of the

relatively dry conditions prevailing

after spring fertilizer application. There was no evidence of increased

soil N fertility, beyond single

year residues, as a result of large N applications over the 13-year period.

In order to achieve the economic optimum grain yield, it was necessary
to

use N applications which

produced inefficient recovery of N. Thus, greater return of N in crop

residues and immobilization at relatively large N applications

(>150 kg ha−1) contributed to an observed build-up
in

soil organic N over the period of study. Plots receiving, on average,

265 kg ha−1 appeared to gain c. 250 kg

ha−1 N over control plots (35 kg ha−1)
after

13 years of N application. Reducing the N application rate from

the economic optimum to a more biologically efficient N rate (156 kg

ha−1) was calculated to result

in an average yield loss of 0·305 t ha−1 and

cause an estimated £17 ha−1 loss in profit.
Evidence for differences between winter wheat

cultivars in acquisition of soil mineral nitrogen and uptake

and utilization of applied fertilizer nitrogen
Authors: FOULKES M. J. , SYLVESTER-BRADLEY R. , SCOTT R. K.
Published: July 2002

The response of cultivars to applied nitrogen was

examined in 11 seasons, 1982–92, in two

experiments per year, normally testing seven cultivars at

seven rates of fertilizer nitrogen. In all, 27

cultivars were tested in 22 experiments throughout

Nottinghamshire, Lincolnshire, Northamptonshire and Suffolk.

Cultivars ranged in their date of introduction from Maris

Huntsman (1969) to Hereward (1988). For each cultivar in

each experiment, the economic optimum yield (Yopt),

the amount of fertilizer N needed to produce it

(Nopt), the grain %N at Nopt, the

offtake of N in the grain

at nil N (Noff(N0)) and Nopt

(Noff(opt)) and the estimated recovery of

fertilizer in the grain at Nopt

(AFRopt) were estimated by fitting linear

plus exponential curves to data for grain yield and

two-straight-line models to data for grain N offtake.

From cross-site analysis, normalized cultivar means

were calculated for each variate. Over the 20-year period

relating to the cultivars in the trial, the

contribution of new genotypes to grain yield improvement

was 1·92 t/ha, Yopt increasing by

96 kg/ha per year. There was no change in grain %N

at Nopt. The effect of changes through breeding from

1969 to 1988 was to increase Noff(opt) by

42 kg/ha (2·1 kg/ha per year), that was

associated with a

decrease in Noff(N0) (equivalent of soil N

offtake) of 15 kg/ha (0·77 kg/ha per year).

Part of the increased requirement for fertilizer N was

fulfilled by an increase in AFRopt of 18% over

the 20-year period. The net effect was for Nopt

itself to increase by 56 kg/ha (2·8 kg/ha per

year). Since survey

evidence indicates no general increase in N use on wheat

by farmers since the mid-1980s, it appears

that current fertilizer use by farmers may be underestimating

the requirement for N now.

Alternatively in previous years N requirements may have

been overestimated. The change in N

available for loss to the environment, from the balance of

grain Noff(opt) and Nopt, was from

11 kg N/ha in 1969 compared to 25 kg N/ha in 1988.

It seems possible that the potential increase in

nitrate levels in groundwater associated with plant type

may not have been realised because farmers

have conserved the amount of N they use.
Effects of high plant populations on the growth and
yield of winter oilseed rape (Brassica napus)
Authors: LEACH J. E. , STEVENSON H. J. , RAINBOW A. J. , MULLEN L. A.
Published: July 2002

The effects of plant density on the growth and yield of winter
oilseed rape
(Brassica napus) were
examined in a series of five multifactorial experiments at Rothamsted Experimental
Station between
1984 and 1989. Plant densities, manipulated by changing the seed rate and
row spacing, or because
of overwinter losses, ranged from 13·5 to 372 plants/m2.
Normalized yields for the multifactorial
plots increased with densities up to 50–60 plants/m2.
In very high density plots in 1987/88, yield
decreased as density increased >150 plants/m2. Plants
grown at high density had fewer pod-bearing
branches per plant but produced more branches/m2. Branch
dry matter (DM) per plant was
decreased by 42%, the number of fertile pods per plant and pod DM/plant
by 37%. There was no
effect of density on the number or DM of pods/m2. Over 74%
of the fertile pods were carried on the
terminal and uppermost branches of plants grown at high density in 1987/88
compared with only
34% in plants grown at low density in 1988/89. Seed DM/plant decreased
with increase in density
but seed size (1000-seed weight) increased. There was no effect of density
on seed glucosinolate or oil
contents.
Effects of beet western yellows virus on growth and
yield of oilseed rape (Brassica napus)
Authors: JAY C. N. , ROSSALL S. , SMITH H. G.
Published: July 2002

Field trials were undertaken in Suffolk in commercial crops of autumn-sown oilseed rape cv.
Capricorn during 1993/94, cv. Apex in 1994/95. Plots were artificially infected with beet western
yellows virus (BWYV) using viruliferous Myzus persicae, giving 73 to 94% infection. Control plots
had natural infection ranging from 0 to 17·8%. Destructive plant samples were taken from each of
the infected and control plots throughout the seasons for growth analyses, and final yields were
measured on 44 m2 areas combine harvested from each plot. The seed yields of infected plots were
26 and 11% lower than control plots in 1994 and 1995 respectively (P<0·001).

Harvested seed yields were shown to be inversely proportional to the area of the plot that was
inoculated with BWYV. Infection significantly lowered the oil content in 1995 from 47·9 to 46·8%
(P<0·001), and increased glucosinolate levels from 16·12 to 18·37 μmol/g (P<0·01). BWYV caused
a significant reduction in plant height and in numbers of primary branches in the 1993/94 trial and
had an effect on the dry weight of the leaves, stalks, racemes and pods at some sample dates in both
seasons. Virus-testing of infected plants showed that BWYV was present in the pod wall, the septum
and seed coat; two of 78 embryo samples also contained virus. It was concluded that BWYV can
cause significant yield losses in those years in which there is a high incidence of virus in the
overwintered crops.
Seed and pod development of autumn-sown,
determinate white lupins (Lupinus albus) in relation to
the assimilation and distribution of dry matter and
nitrogen in crops grown at different densities
Authors: MILFORD G. F. J. , SHIELD I. F. , STEVENSON H. J. , SCOTT T. , LEACH J. E.
Published: July 2002

Pod and seed growth were studied in two experiments in which the plant's source-sink relationships
were modified by (a) manually pruning an autumn-sown, indeterminate white lupin variety, Lunoble,
to a determinate form, and (b) by growing a determinate variety, Lucyane, at densities ranging from
7 to 35 plants/m2. The pruning experiments indicated that the faster pod growth rate of determinate
genotypes was not an inherent genetic trait but an indirect physiological consequence of the plant's
changed architecture. In the density experiment, crop dry matter (DM) and nitrogen (N) were
maximum at the end of pod extension in late July and similar across the plant density range at c. 12 t
DM and 320 kg N/ha. Therefore, the amount of dry matter per plant decreased proportionately with
the increase in plant number. The DM and N contents of the pod walls were also maximum at the
end of pod extension, but seeds contained only a third of their final DM and a quarter of their final
N. Protein accumulation during the final stages of seed growth, therefore, depended on the
remobilization of nitrogen from other plant organs, primarily the leaves and pod walls. Nitrogen
withdrawn from the leaves accounted for 44% of the gain in the pods, and N withdrawn from pod
walls for 50–60% of the gain in the seed.

Seed number/m2 was the major yield component. Seeds and pods mainly aborted during early
development, but seed number per pod was also decreased by some seed abortion after full pod
extension, especially in first-order pods of plants grown at high density. The number of late-aborted
seeds was negatively correlated with the amount of N remobilized from the pod wall. In determinate
lupins, which have highly synchronous flowering and pod development, the large and sudden
remobilization of nitrogen from leaves and pod walls for seed growth and protein accumulation
triggered crop senescence.
Presidents, Precedents and the Use of Military Force
Authors: MERVIN DAVID
Published: July 2002

In the late summer of 1996 Iraqi troops moved into the Kurdish
“safe
haven” in Northern Iraq, thereby triggering a crisis of national
security
for the United States. Unsurprisingly, this incident led to speculation
in
the media about the nature of President Clinton's response. Would
he be
able to meet this test of his leadership? What form would any military

action take? Would it be strong enough, or would it be an overreaction?

In the event, the president ordered two cruise missile strikes against
Iraqi
defence installations and substantially extended the no-fly zone in
Southern Iraq set up after the Gulf War. These actions were the subject

of debate in the United States Senate and, after some partisan wrangling,

and a few rumbles of complaint about inadequate consultation, a non-binding

resolution endorsing the missile strikes was approved by a vote
of 96–1. But, as was noted by the press, “none of this really
mattered
because such ‘sense of the Senate’ resolutions have no binding
effect and
are largely ignored, even inside the Beltway.”

What was striking about this incident was that throughout the crisis
the
United States Congress was little more than a bystander. Inevitably all

eyes turned to the president. It was he and not the national legislature
that
became the focus of public and media attention. Does he have the
mettle
needed? What will he do, and will his actions be sufficient
to deal with the
situation? These were the sort of questions being debated on the talk
shows and in the press. To put it bluntly, at this moment, there was little

interest in what the legislature might say or do, the mighty Congress,
at
this point at least, was reduced to a role comparable, dare it be said,
to that
of the British House of Commons. The situation called for leadership and

decisive action and no one was under any illusion that the legislature

could provide either, only the president was in a position to meet these

needs. When it comes to the making of foreign policy, and particularly

when crises of national security arise, the president, it seems, is inevitably,

the main player, the senior partner.
DETERMINANTS OF CONTRACEPTIVE DISCONTINUATION IN SIX DEVELOPING COUNTRIES
Authors: ALI MOHAMED , CLELAND JOHN
Published: July 2002

This analysis investigates the determinants of contraceptive discontinuation in six developing countries, using data from Phase I surveys of the DHS programme. Cumulative probabilities of discontinuation at 24 months for reasons other than the desire for another child were examined. By this time, typically about 40% of couples have stopped use and most are subsequently at risk of an unwanted conception. Discontinuation of IUD use was found to be less common than for other methods, partly perhaps because cessation of use requires a deliberate decision to have the device removed.

The most important results are negative ones. Neither the schooling of couples nor their type of residence exerted appreciable influence on discontinuation. The policy and programme implications are discussed. Prior use of a method, fertility preferences and the related demographic factors of age and family size emerged as pervasive predictors of discontinuation.
Transition delay by surface heating: a zonal analysis for axisymmetric bodies
Authors: GOVINDARAJAN RAMA , NARASIMHA R.
Published: July 2002

It has long been known from linear stability theory that heating a surface immersed in
water flow tends to stabilize the boundary layer on the surface, suggesting that there
may be a corresponding delay in transition. Experiments confirm the suggestion, but
based on intermittency data on a heated body of revolution (Lauchle & Gurney 1984)
it has been inferred that incremental changes in transition Reynolds number diminish
as the overheat increases. The parameter chosen to locate transition in the analysis
leading to this conclusion corresponds to the point where the intermittency is 0.5.
However, intermittency distributions in the transition zone on an axisymmetric body
may contain what have been called ‘subtransitions’ (Narasimha 1984). Taking this
possibility into account, we formulate here a model for the variation of intermittency
with flow Reynolds number at a fixed station on the body, as in the experiments. The
rate at which turbulent spots merge with each other is shown to determine the location
of subtransition. The transition onset Reynolds number (corresponding to the location
where intermittency begins to depart from zero), inferred from the data on the basis
of this model, shows a continuing increase with the temperature overheat, a trend in
closer agreement with stability theory; but the axisymmetric body geometry results
in a very short transition zone, countering in part the benefits of transition delay.
Flow along a diverging channel
Authors: DENNIS S. C. R. , BANKS W. H. H. , DRAZIN P. G. , ZATURSKA M. B.
Published: July 2002

This paper treats the two-dimensional steady flow of a viscous

incompressible fluid

driven through a channel bounded by two walls which are the radii of a
sector

and two

arcs (the ‘inlet’ and ‘outlet’), with the same
centre

as the sector, at which inflow and

outflow conditions are imposed. The computed flows are related to both
a laboratory

experiment and recent calculations of the linearized ‘spatial’
modes

of Jeffery–Hamel

flows. The computations, at a few values of the angle between the walls
of the sector

and several values of the Reynolds number, show how the first bifurcation
of the flow

in a channel is related to spatial instability. They also show how the
end

effects due to

conditions at the inlet and outlet of the channel are related to the spatial

modes: in

particular, Saint-Venant's principle breaks down when the flow is
spatially

unstable,

there being a temporally stable steady flow for which small changes at
the inlet or

outlet create substantial effects all along the channel. The choice of
a sector

as the

shape of the channel is to permit the exploitation of knowledge of the
spatial modes

of Jeffery–Hamel flows, although we regard the sector as an example
of

channels with walls of moderate curvature.
Nonlinear interactions in turbulence with strong
irrotational straining
Authors: KEVLAHAN N.K.-R. , HUNT J.C.R.
Published: July 2002

The rate of growth of the nonlinear terms in the vorticity equation
are analysed
for a turbulent flow with r.m.s. velocity u0 and integral
length scale L subjected to
a strong uniform irrotational plane strain S, where
(u0/L)/S=ε[Lt ]1. The rapid
distortion theory (RDT) solution is the zeroth-order term of the perturbation series
solution in terms of ε. We use the asymptotic form of the convolution
integrals for the leading-order nonlinear terms when
β= exp(−St)[Lt ]1 to determine at what
time t and beyond what wavenumber k (normalized on L)
the perturbation series in
ε fails, and hence derive the following conditions for the validity of
RDT in these
flows. (a) The magnitude of the nonlinear terms of order ε depends
sensitively on the
amplitude of eddies with large length scales in the direction x2 of
negative strain. (b)
If the integral of the velocity component u2 is zero the leading-order
nonlinear terms increase and decrease in the same way as the linear terms, even
those that decrease exponentially. In this case RDT calculations of vorticity
spectra become invalid at a time
tNL∼L/u0k−3
independent of ε and the power law of the initial energy spectrum, but
the calculation of the r.m.s. velocity components by RDT remains accurate until
t=
TNL∼L/u0,
when the maximum amplification of r.m.s. vorticity is
ω/S∼εexp(ε−1)[Gt ]1. (c)
If this special condition does not apply, the leading-order nonlinear terms increase
faster than the linear terms by a factor O(β−1).
RDT calculations of the vorticity spectrum then fail at a shorter time
tNL∼(1/S)
ln(ε−1k−3); in this case
TNL∼(1/S)
ln(ε−1) and the maximum amplification of r.m.s. vorticity is
ω/S∼1. (d) Viscous effects dominate when
t[Gt ](1/S)
ln(k−1(Re/ε)1/2). In
the first case RDT fails immediately in this range, while in the second case
RDT usually fails before viscosity becomes important. The general analytical
result (a) is confirmed by
numerical evaluation of the integrals for a particular form of eddy, while
(a), (b), (c)
are explained physically by considering the deformation of differently oriented
vortex rings. The results are compared with small-scale turbulence approaching
bluff bodies where ε[Lt ]1 and β[Lt ] 1.

These results also explain dynamically why the intermediate eigenvector of the
strain S aligns with the vorticity vector, why the greatest increase in
enstrophy production occurs in regions where S has a positive intermediate
eigenvalue; and why large-scale strain S of a small-scale vorticity
can amplify the small-scale strain
rates to a level greater than S – one of the essential
characteristics of high-Reynolds-number turbulence.
The stability of rotating-disc boundary-layer

flow over a compliant wall. Part 1. Type I and II instabilities
Authors: COOPER A. J. , CARPENTER PETER W.
Published: July 2002

A theoretical study into the effects of wall compliance on

the stability of the rotating-disc boundary layer is described.

A single-layer viscoelastic wall model is coupled to

a sixth-order system of fluid stability equations which take into

account the effects

of viscosity, Coriolis acceleration, and streamline curvature. The coupled
system of

equations is integrated numerically by a spectral Chebyshev-tau technique.

Travelling and stationary modes are studied and wall compliance

is found to greatly increase the complexity of the eigenmode spectrum.
It is

effective in stabilizing the

inviscid Type I (or cross-flow) instability. The effect on the

viscous (Type II) eigenmode

is more complex and can be strongly destabilizing. An analysis of the energy
flux

indicates that this destabilization arises as a result of a large degree
of energy

production by viscous stresses at the wall/flow interface.

The Type I and II instabilities are shown to be negative and

positive energy waves

respectively. The co-existence of eigenmodes of opposite energy type indicates
the

possibility of modal interaction and coalescence. It is found that, compared
with

the rigid disc, wall compliance promotes the interaction and coalescence
of the

Type I and II eigenmodes. There is an associated strong instability which
appears

to be characterized by marked horizontal motion of the compliant surface.
Modal

coalescence is interpreted physically as producing local algebraic growth
which

could advance the onset of nonlinear effects.
Tertiary solutions and their stability in rotating
plane Couette flow
Authors: NAGATA M.
Published: July 2002

The stability of nonlinear tertiary solutions in rotating
plane Couette flow is examined
numerically. It is found that the tertiary flows, which bifurcate from
two-dimensional
streamwise vortex flows, are stable within a certain range of the rotation
rate when
the Reynolds number is relatively small. The stability boundary is determined
by
perturbations which are subharmonic in the streamwise direction. As the
Reynolds
number is increased, the rotation range for the stable tertiary motions
is destroyed
gradually by oscillatory instabilities. We expect that the tertiary flow
is overtaken by
time-dependent motions for large Reynolds numbers. The results are compared
with
the recent experimental observation by Tillmark & Alfredsson (1996).
Asymptotic solutions for nonlinear magnetoconvection
Authors: MATTHEWS P. C.
Published: July 2002

Convection in a vertical magnetic field occurs in narrow cells in the physically
relevant limit where the Chandrasekhar number Q becomes large, corresponding to
a strong field or small diffusion. This allows asymptotic solutions to be developed
for fully nonlinear convection, requiring only the solution of a nonlinear boundary
value problem. Solutions for steady and oscillatory magnetoconvection are obtained,
with different scalings. In the steady case, the heat flux and the fluid velocity are
found at leading order in the asymptotic expansion and the vertical velocity scales
as Q1/6. In the oscillatory case, where
it is necessary to continue to second order,
the vertical velocity is of order Q1/3 and the frequency
of the oscillations is always
greater than that predicted by linear theory. The heat flux does not depend on either
the wavenumber or the planform.
Wave–vortex interaction in rotating shallow
water. Part 1. One space dimension
Authors: KUO ALLEN C. , POLVANI LORENZO M.
Published: July 2002

Using a physical space (i.e. non-modal) approach, we investigate interactions between
fast inertio-gravity (IG) waves and slow balanced flows in a shallow rotating fluid.
Specifically, we consider a train of IG waves impinging on a steady, exactly balanced
vortex. For simplicity, the one-dimensional problem is studied first; the limitations
of one-dimensionality are offset by the ability to define balance in an exact way.
An asymptotic analysis of the problem in the small-amplitude limit is performed to
demonstrate the existence of interactions. It is shown that these interactions are not
confined to the modification of the wave field by the vortex but, more importantly,
that the waves are able to alter in a non-trivial way the potential vorticity associated
with that vortex. Interestingly, in this one-dimensional problem, once the waves have
traversed the vortex region and have propagated away, the vortex exactly recovers
its initial shape and thus bears no signature of the interaction. Furthermore, we
prove this last result in the case of arbitrary vortex and wave amplitudes. Numerical
integrations of the full one-dimensional shallow-water equations in strongly nonlinear
regimes are also performed: they confirm that time-dependent interactions exist and
increase with wave amplitude, while at the final state the vortex bears no sign of the
interaction. In addition, they reveal that cyclonic vortices interact more strongly with
the wave field than anticyclonic ones.