bluuebunny/crossref_metadata_2025 huggingface dataset:
Arthropod community structure in pastures of an island archipelago (Azores): looking for local–regional species richness patterns at fine-scales
Authors: Borges P.A.V. , Brown V.K.
Published: May 2004

The arthropod species richness of pastures in three Azorean islands was used to examine the relationship between local and regional species richness over two years. Two groups of arthropods, spiders and sucking insects, representing two functionally different but common groups of pasture invertebrates were investigated. The local–regional species richness relationship was assessed over relatively fine scales: quadrats (= local scale) and within pastures (= regional scale). Mean plot species richness was used as a measure of local species richness (= α diversity) and regional species richness was estimated at the pasture level (= γ diversity) with the ‘first-order-Jackknife’ estimator. Three related issues were addressed: (i) the role of estimated regional species richness and variables operating at the local scale (vegetation structure and diversity) in determining local species richness; (ii) quantification of the relative contributions of α and β diversity to regional diversity using additive partitioning; and (iii) the occurrence of consistent patterns in different years by analysing independently between-year data. Species assemblages of spiders were saturated at the local scale (similar local species richness and increasing β-diversity in richer regions) and were more dependent on vegetational structure than regional species richness. Sucking insect herbivores, by contrast, exhibited a linear relationship between local and regional species richness, consistent with the proportional sampling model. The patterns were consistent between years. These results imply that for spiders local processes are important, with assemblages in a particular patch being constrained by habitat structure. In contrast, for sucking insects, local processes may be insignificant in structuring communities.
An interspersed refuge for Sitodiplosis mosellana (Diptera: Cecidomyiidae) and a biocontrol agent Macroglenes penetrans (Hymenoptera: Pteromalidae) to manage crop resistance in wheat
Authors: Smith M.A.H. , Lamb R.J. , Wise I.L. , Olfert O.O.
Published: May 2004

An interspersed refuge of susceptible plants in a resistant, spring-sown wheat crop was tested as a strategy to protect crop resistance against evolution of virulence by the wheat midge Sitodiplosis mosellana (Géhin), and also to conserve a biocontrol agent Macroglenes penetrans(Kirby). Eight replicated field experiments were conducted using seed mixtures of 0, 5, 10, 15 and 100% or 0, 5 and 100% susceptible wheat with an agronomically similar wheat expressing the antibiotic resistance gene Sm1. The frequencies of eggs, mature larvae and parasitized larvae in susceptible and resistant wheat spikes, and midge-affected seeds in the harvest, were recorded for each plot. In susceptible wheat, insect densities and seed damage were typical of those in commercial wheat. In resistant wheat, few larvae completed development, 2% or less compared with about 80% in susceptible wheat, when larvae were sampled at maturity. This resistant wheat also deterred midge oviposition, reducing egg densities by 65% compared with susceptible wheat. The wheat midge and its parasitoid oviposited throughout the plots, and parasitism was density independent. The densities of mature midge larvae and parasitoids were in proportion to the size of the refuge. A 5% susceptible refuge produced about 41 mature larvae for each mature larva from the resistant wheat, and provided effective control of damage. An interspersed refuge of susceptible plants in resistant wheat is a promising strategy for sustaining resistance conferred by Sm1 and biocontrol of the wheat midge.
Effects of age and food source on secondary chemistry of larvae of Lymantria species (Lepidoptera: Lymantriidae)
Authors: Deml R.
Published: May 2004

Haemolymph and osmeterial secretions of caterpillars of Lymantria monacha (Linnaeus) and L. concolor Walker were analysed by gas chromatography/mass spectrometry for low molecular weight secondary metabolites. The similarities of their chemical compositions were determined by means of cluster analysis techniques in order to characterize possible chemical variations related to developmental stage or food of the larvae. For this purpose, two dissimilarity coefficients (Euclidean distances, Canberra metrics) and four clustering methods (UPGMA, WPGMA, WPGMC, single linkage) were combined. The patterns of secondary compounds obtained from the haemolymph and osmeterial secretions studied did not differ statistically significantly between two groups of L. monacha larvae fed with either larch, Larix decidua Mil., or Norway spruce, Picea abies (L.), indicating no relevant influence of plant chemistry. However, haemolymph of penultimate instar larvae of L. concolor fed on Rhododendroncontained a mixture of compounds differing statistically significantly from that of last instar caterpillars. The total compositions of the corresponding gland secretions were statistically identical though the presence/amounts of individual compounds varied. This suggested that the haemolymph composition reflected changing physiological requirements of the successive instars, whereas the composition of the defensive mixtures remained comparatively constant, possibly due to a constant spectrum of potential enemies. A more pronounced age-dependence of larval chemistry was shown by a similar analysis of data from various developmental stages of L. dispar (Linnaeus) and one of its food plants. This analysis suggested plant composition affected the secondary chemistry of early larval instars of L. dispar. The results are discussed in terms of the roles of secondary metabolites in defence against natural enemies.
Fasciola hepatica and Paramphistomum daubneyi: field observations on the transport and outcome of floating metacercariae in running water
Authors: Rondelaud D. , Vignoles P. , Vareille-Morel C. , Abrous M. , Mage C. , Mouzet R. , Dreyfuss G.
Published: May 2004

Experimental investigations in eight open drainage ditches and furrows from central France were carried out to analyse the dispersal of floating metacercariae of two digenean species by running water and to determine the outcome of larvae which settled on Nasturtium officinale (watercress). The frequencies of larvae found after their transport by water ranged from 33% to 49.7%, thus indicating that more than half of the metacercariae used in this experiment had fallen to the bottom of the water during this transport. The nature of the site (furrow, or ditch supplied by a spring) had a significant effect on the distribution of floating larvae, while the digenean species had no effect. Low percentages of metacercariae on watercress were noted in furrows (3.5–4.3% of larvae) and ditches (0.8–1.3%). When the watercress grew, most larvae that had settled on leaves and stems died but there were always several living metacercariae on this plant (0.7–1.5% of larvae for Fasciola hepatica and 0.2–0.5% for Paramphistomum daubneyi). The weak buoyancy of these floating cysts on running water limited their dispersal and, consequently, led to a real diminution of risks incurred by definitive hosts towards these metacercariae.
Epidemiology of Ancylostoma spp. in the endangered Iberian lynx (Lynx pardinus) in the Doñana National Park, south-west Spain
Authors: Vicente J. , Palomares F. , Ruiz de Ibañez A. , Ortiz J.
Published: May 2004

The epidemiology of Ancylostoma spp. was studied in the endangered Iberian lynx (Lynx pardinus) in the Doñana National Park, south-west Spain. Faecal samples were collected throughout a complete annual cycle (August 1997 to September 1998). The overall egg prevalence of Ancylostoma spp. was 57.8%. The pattern of abundance of Ancylostoma spp. eggs in faeces was overdispersed. Juvenile lynx demonstrated a statistically higher prevalence and abundance of Ancylostoma spp. than in adults. These levels of egg output (maximum 21195 epg), as previously reported in free ranging large felid cubs, could be close to disease involvement. The potential pathogenicity of hookworms and the influence of individual and ecological factors on hookworm transmission in the Iberian lynx from the Doñana National Park population are discussed.
The influence of climate on the distribution of monogeneans of anurans in Nigeria
Authors: Aisien S.O. , Salami L.A. , Obaro F.E. , Erakpoweri S.O.
Published: May 2004

Investigations undertaken on the monogeneans of amphibians in Nigeria have shown that host ecology has an influence on the distribution of these monogeneans. Amphibians from humid environments of the rainforest, a freshwater swamp and mangrove harboured no monogeneans, whereas those occurring in drier conditions in the savannah-mosaic and guinea savannah yielded five species of polystomatid parasites: Polystoma prudhoei from Bufo regularis, Polystoma galamensis from Rana galamensis, Eupolystoma alluaudi from Bufo regularis and Bufo maculatus, and two unidentified Polystoma species from Bufo regularis and Ptychadena oxyrynchus, respectively. Some of these monogeneans appear to have reproduction cycles which are synchronized with those of the hosts. The prevalence of E. alluaudi in Bufo spp. caught in New Bussa (68.4% in B. regularis and 82.3% in B. maculatus) were higher than those reported for this parasite in other locations in West Africa and for Eupolystoma anterorchis in Bufo pardalis from the Cape Flats of South Africa.
Density-dependent effects on the survival and growth of the rodent stomach wormProtospirura muricolain laboratory mice
Authors: Lowrie F.M. , Behnke J.M. , Barnard C.J.
Published: May 2004

The spirurid nematode,Protospirura muricola, is of intrinsic interest as a rodent model of gastric nematode infections. Since worm burdens can be very heavy in nature, density dependent processes may constrain parasite growth. Laboratory mice (BKW) were exposed to varying doses of infective larvae ofP. muricolain the range 5 to 40 third-stage larvae (L3), in four separate experiments in which progressively higher doses were utilized. All mice were culled 60 days after infection and a total of 518 worms (226 male and 292 female worms) was recovered, measured and weighed. Overall survival was 58.9%, but survival declined significantly with increasing dose by approximately 21% (from 66% at 5 L3 per mouse to 52% at 40 L3 per mouse). The length and weight of worms correlated positively in both sexes. Total worm biomass increased linearly with increasing numbers of worms. However, whilst the length and weight of male worms declined with increasing worm burden (8.4 and 24.6% respectively), female worms were less affected, only length showing a significant reduction with increasing parasite burden (16.0%). Therefore, increasing worm burdens impeded growth ofP. muricola, but reduction in length and weight were relatively small in relation to the overall size of this nematode. Increasing worm burdens were associated with loss of host weight and reduction in stomach weight and worm burdens in excess of 20 exerted a measurable cost to the host, which in the field, may be associated with loss of overall host fitness.
Cross-cultural comparison of growth, maturation and adiposity indices of two contrasting adolescent populations in rural Senegal (West Africa) and Martinique (Caribbean)
Authors: Bénéfice Eric , Caïus Nathalie , Garnier Denis
Published: May 2004

Objectives:

To stress the importance of social and environment (nutritional) factors in determining the growth spurt during puberty and the risk of excessive adiposity, two contrasting adolescent populations, one from a rural area of Senegal (West Africa) and the other from Martinique (French West Indies), were compared.

Design:

Cross-cultural comparison of contrasting populations. Adolescents from Senegal belonged to a cohort followed up since 1995. Adolescents from Martinique participated in a cross-sectional nutritional survey that covered the entire island.

Subjects:

A total of 507 adolescents (mean age: 14.3 ± 0.7 years) from Senegal (319 girls and 188 boys) and 703 adolescents from Martinique (351 boys and 352 girls) were surveyed.

Results:

Differences in growth and maturation were striking: boys in Martinique were 22.7 kg heavier and 20.1 cm taller than boys in Senegal. Differences were less important for girls but still evident: 12.6 kg in weight and 10.5 cm in stature. In Senegal, there were virtually no overweight adolescents, but 18% of girls and 50% of boys could be considered as malnourished. In Martinique, 19% of girls and 23% of boys were overweight or obese. Adolescent girls from Martinique were also sexually more mature than adolescent girls from Senegal. When comparisons were repeated after Senegalese girls reached menarche, differences in weight and body mass index disappeared, but Senegalese girls were still shorter than girls from Martinique.

Conclusions:

Adolescents are extremely susceptible to nutritional changes and their particular situation needs to be incorporated into nutritional prevention programmes.
A longitudinal assessment of the diet and growth of malnourished children participating in nutrition rehabilitation centres in Accra, Ghana
Authors: Colecraft Esi K , Marquis Grace S , Bartolucci Alfred A , Pulley LeaVonne , Owusu W Bruce , Maetz H Michael
Published: May 2004

Objective:

To examine the adoption of feeding recommendations among caregivers of children recuperating from malnutrition and assess the determinants of growth of children attending a nutrition rehabilitation centre (NRC) in Accra, Ghana.

Design:

Longitudinal study in which attendance and maternal programme participation were recorded daily and children's anthropometry and dietary intake were measured at four time points (admission, interim, exit, post-exit) at the NRC and participants' homes.

Setting:

NRCs at four polyclinics and participants' homes in Accra, Ghana.

Subjects:

One hundred and eight caregivers and their 116 children referred to an NRC between November 1999 and July 2000.

Results:

Most caregivers attended the NRC sporadically (effective length of stay was 1.4 ± 0.1 months). Use of NRC-promoted foods in the home after discharge was low due to inaccessibility of the food items, lack of preparation knowledge or money, child preferences and the common practice of purchasing ready-to-eat foods. Although there were significant increases in children's weight-for-age (P = 0.048) and weight-for-height (P = 0.002) Z-scores between enrolment and discharge, most children discontinued programme participation before adequate recuperation.

Conclusions:

The NRC education did not address the use of street foods for child feeding and was unsuccessful in changing in-home feeding behaviour. The prominence of street foods in children's diets warrants re-evaluation of the NRC's educational approaches to enhance their responsiveness to caregivers' needs and effectiveness for the continued recuperation of malnourished children at home. NRC feeding strategies need improvement to ensure adequate provision of energy and nutrients to support catch-up growth in children.
Definability in the lattice of equational theories of commutative semigroups
Authors: Kisielewicz Andrzej
Published: May 2004

In this paper we study first-order definability in the lattice of equational theories of commutative semigroups. In a series of papers, J. Ježek, solving problems posed by A. Tarski and R. McKenzie, has proved, in particular, that each equational theory is first-order definable in the lattice of equational theories of a given type, up to automorphism, and that such lattices have no automorphisms besides the obvious syntactically defined ones (with exceptions for special unary types). He has proved also that the most important classes of theories of a given type are so definable. In a later paper, Ježek and McKenzie have “almost proved" the same facts for the lattice of equational theories of semigroups. There were good reasons to believe that the same can be proved for the lattice of equational theories of commutative semigroups. In this paper, however, we show that the case of commutative semigroups is different.
Nonlinearizable actions of dihedral groups on affine space
Authors: Masuda Kayo
Published: May 2004

Let

G
G

be a reductive, non-abelian, algebraic group defined over

C

\mathbb {C}

. We investigate algebraic

G
G

-actions on the total spaces of non-trivial algebraic

G
G

-vector bundles over

G
G

-modules with great interest in the case that

G
G

is a dihedral group. We construct a map classifying such actions of a dihedral group in some cases and describe the spaces of those non-linearizable actions in some examples.
The best constant of the Moser-Trudinger inequality on 𝑆²
Authors: Sano Yuji
Published: May 2004

We consider the best constant of the Moser-Trudinger inequality on

S

2

\textbf {S}^2

under a certain orthogonality condition. Applying Moser’s calculation, we construct a counterexample to the sharper inequality with the condition.
Non-isotopic symplectic tori in the same homology class
Authors: Etgü Tolga , Park B.
Published: May 2004

For any pair of integers

n
≥
1

n\geq 1

and

q
≥
2

q\geq 2

, we construct an infinite family of mutually non-isotopic symplectic tori representing the homology class

q
[
F
]

q[F]

of an elliptic surface

E
(
n
)

E(n)

, where

[
F
]

[F]

is the homology class of the fiber. We also show how such families can be non-isotopically and symplectically embedded into a more general class of symplectic

4
4

-manifolds.
Linking numbers in rational homology 3-spheres, cyclic branched covers and infinite cyclic covers
Authors: Przytycki Józef , Yasuhara Akira
Published: May 2004

We study the linking numbers in a rational homology

3
3

-sphere and in the infinite cyclic cover of the complement of a knot. They take values in

Q

\mathbb {Q}

and in

Q

(

Z

[
t
,

t

−
1

]
)

{Q}(\mathbb {Z}[t,t^{-1}])

, respectively, where

Q

(

Z

[
t
,

t

−
1

]
)

{Q}(\mathbb {Z}[t,t^{-1}])

denotes the quotient field of

Z

[
t
,

t

−
1

]

\mathbb {Z}[t,t^{-1}]

. It is known that the modulo-

Z

\mathbb {Z}

linking number in the rational homology

3
3

-sphere is determined by the linking matrix of the framed link and that the modulo-

Z

[
t
,

t

−
1

]

\mathbb {Z}[t,t^{-1}]

linking number in the infinite cyclic cover of the complement of a knot is determined by the Seifert matrix of the knot. We eliminate ‘modulo 

Z

\mathbb {Z}

’ and ‘modulo 

Z

[
t
,

t

−
1

]

\mathbb {Z}[t,t^{-1}]

’. When the finite cyclic cover of the

3
3

-sphere branched over a knot is a rational homology

3
3

-sphere, the linking number of a pair in the preimage of a link in the

3
3

-sphere is determined by the Goeritz/Seifert matrix of the knot.
A positivstellensatz for non-commutative polynomials
Authors: Helton J. , McCullough Scott
Published: May 2004

A non-commutative polynomial which is positive on a bounded semi-algebraic set of operators has a weighted sum of squares representation. This Positivstellensatz parallels similar results in the commutative case. A broader issue is, to what extent does real semi-algebraic geometry extend to non-commutative polynomials? Our “strict" Positivstellensatz is positive news, on the opposite extreme from strict positivity would be a Real Nullstellensatz. We give an example which shows that there is no non-commutative Real Nullstellensatz along certain lines. However, we include a successful type of non-commutative Nullstellensatz proved by George Bergman.
On the structure of a sofic shift space
Authors: Thomsen Klaus
Published: May 2004

The structure of a sofic shift space is investigated, and Krieger’s embedding theorem and Boyle’s factor theorem are generalized to a large class of sofic shifts.
The double bubble problem on the flat two-torus
Authors: Corneli Joseph , Holt Paul , Lee George , Leger Nicholas , Schoenfeld Eric , Steinhurst Benjamin
Published: May 2004

We characterize the perimeter-minimizing double bubbles on all flat two-tori and, as corollaries, on the flat infinite cylinder and the flat infinite strip with free boundary. Specifically, we show that there are five distinct types of minimizers on flat two-tori, depending on the areas to be enclosed.
𝐿^{𝑝}→𝐿^{𝑞} regularity of Fourier integral operators with caustics
Authors: Comech Andrew
Published: May 2004

The caustics of Fourier integral operators are defined as caustics of the corresponding Schwartz kernels (Lagrangian distributions on

X
×
Y

X\times Y

). The caustic set

Σ
(

C

)

\Sigma (\mathbf {C})

of the canonical relation is characterized as the set of points where the rank of the projection

π
:

C

→
X
×
Y

\pi :\mathbf {C}\to X\times Y

is smaller than its maximal value,

dim
⁡
(
X
×
Y
)
−
1

\dim (X\times Y)-1

. We derive the

L
p

(
Y
)
→

L
q

(
X
)

L^ p(Y)\to L^ q(X)

estimates on Fourier integral operators with caustics of corank

1
1

(such as caustics of type

A

m
+
1

A_{m+1}

,

m
∈

N

m\in \mathbb {N}

). For the values of

p
p

and

q
q

outside of a certain neighborhood of the line of duality,

q
=

p
′

q=p’

, the

L
p

→

L
q

L^ p\to L^ q

estimates are proved to be caustics-insensitive. We apply our results to the analysis of the blow-up of the estimates on the half-wave operator just before the geodesic flow forms caustics.
Complete linear Weingarten surfaces of Bryant type. A Plateau problem at infinity
Authors: Gálvez José , Martínez Antonio , Milán Francisco
Published: May 2004

In this paper we study a large class of Weingarten surfaces which includes the constant mean curvature one surfaces and flat surfaces in the hyperbolic 3-space. We show that these surfaces can be parametrized by holomorphic data like minimal surfaces in the Euclidean 3-space and we use it to study their completeness. We also establish some existence and uniqueness theorems by studing the Plateau problem at infinity: when is a given curve on the ideal boundary the asymptotic boundary of a complete surface in our family? and, how many embedded solutions are there?
Chk1 activation requires Rad9 S/TQ-site phosphorylation to promote association with C-terminal BRCT domains of Rad4TOPBP1
Authors: Furuya Kanji , Poitelea Marius , Guo Liandi , Caspari Thomas , Carr Antony M.
Published: May 2004

To gain insight into the function and organization of proteins assembled on the DNA in response to genotoxic insult we investigated the phosphorylation of the Schizosaccharomyces pombe PCNA-like checkpoint protein Rad9. C-terminal T412/S423 phosphorylation of Rad9 by Rad3ATR occurs in S phase without replication stress. Rad3ATR and Tel1ATM phosphorylate these same residues, plus additional ones, in response to DNA damage. In S phase and after damage, only Rad9 phosphorylated on T412/S423, but not unphosphorylated Rad9, associates with a two-BRCT-domain region of the essential Rad4TOPBP1 protein. Rad9–Rad4TOPBP1 interaction is required to activate the Chk1 damage checkpoint but not the Cds1 replication checkpoint. When the Rad9-T412/S423 are phosphorylated, Rad4TOPBP1 coprecipitates with Rad3ATR, suggesting that phosphorylation coordinates formation of an active checkpoint complex.
Chromatin decondensation and nuclear reorganization of the HoxB locus upon induction of transcription
Authors: Chambeyron Séverine , Bickmore Wendy A.
Published: May 2004

The colinearity of genes in Hox clusters suggests a role for chromosome structure in gene regulation. We reveal programmed changes in chromatin structure and nuclear organization upon induction of Hoxb expression by retinoic acid. There is an early increase in the histone modifications that are marks of active chromatin at both the early expressed gene Hoxb1, and also at Hoxb9 that is not expressed until much later. There is also a visible decondensation of the chromatin between Hoxb1 and Hoxb9 at this early stage. However, a further change in higher-order chromatin structure, looping out of genes from the chromosome territory, occurs in synchrony with the execution of the gene expression program. We suggest that higher-order chromatin structure regulates the expression of the HoxB cluster at several levels. Locus-wide changes in chromatin structure (histone modification and chromatin decondensation) may establish a transcriptionally poised state but are not sufficient for the temporal program of gene expression. The choreographed looping out of decondensed chromatin from chromosome territories may then allow for activation of high levels of transcription from the sequence of genes along the cluster.
Conservation of the global sex determination gene tra-1 in distantly related nematodes
Authors: Pires-daSilva André , Sommer Ralf J.
Published: May 2004

Sex determination has long intrigued evolutionists, geneticists, and developmental biologists in a similar way. Substantial evidence indicates that sex determination evolves rapidly and, therefore, can be used to study how molecular patterning processes evolve. In Caenorhabditis elegans, sex determination relies on a signaling pathway that involves a cascade of negatively acting factors, finally triggering the GLI-family zinc-finger transcription factor TRA-1. We have started to investigate sex determination in the nematode satellite species Pristionchus pacificus that is separated from C. elegans for 200–300 million years. In P. pacificus, animals with two X chromosomes develop as hermaphrodites, whereas XO animals develop as males. We used an unbiased forward genetic approach and isolated several mutants with a hermaphrodite to male transformation of the XX karyotype. We identified one complementation group as representing the P. pacificus ortholog of tra-1, providing the first evidence for the conservation of a global sex determination gene over a time period of at least 200 million years. A Ppa-tra-1 morpholino phenocopies Ppa-tra-1 mutants and establishes the morpholino technology as a reverse genetic approach in P. pacificus.
Snail blocks the cell cycle and confers resistance to cell death
Authors: Vega Sonia , Morales Aixa V. , Ocaña Oscar H. , Valdés Francisco , Fabregat Isabel , Nieto M. Angela
Published: May 2004

The Snail zinc-finger transcription factors trigger epithelial-mesenchymal transitions (EMTs), endowing epithelial cells with migratory and invasive properties during both embryonic development and tumor progression. During EMT, Snail provokes the loss of epithelial markers, as well as changes in cell shape and the expression of mesenchymal markers. Here, we show that in addition to inducing dramatic phenotypic alterations, Snail attenuates the cell cycle and confers resistance to cell death induced by the withdrawal of survival factors and by pro-apoptotic signals. Hence, Snail favors changes in cell shape versus cell division, indicating that with respect to oncogenesis, although a deregulation/increase in proliferation is crucial for tumor formation and growth, this may not be so for tumor malignization. Finally, the resistance to cell death conferred by Snail provides a selective advantage to embryonic cells to migrate and colonize distant territories, and to malignant cells to separate from the primary tumor, invade, and form metastasis.
The value of active scanning to senior executives
Authors: Nastanski Michael
Published: May 2004

This paper examines the elements of active scanning as a tool to interpret rapidly changing markets. Active scanning is the concerted effort of an organization to direct its intelligence gathering activities toward its environment, markets and customers by integrating diverse information inputs into a cohesive perspective of rapidly changing markets and emerging opportunities. A Delphi process was used to present these elements to a panel of senior decision‐makers including Directors and Vice‐Presidents from Compaq, AT&T, Microsoft and IBM. The results suggest that the active scanning is important to organizations operating in turbulent environments when future states are unpredictable. The implications include developing new sensing and interpretation skills for managers to help the organization interpret and respond to their environmental pressures.
Inhibiting factors of implementing total quality management on construction sites
Authors: Haupt Theo C. , Whiteman Daniel E.
Published: May 2004

Quality systems entail having the organizational structure, responsibilities, procedures, processes and resources for implementing quality management such that there is a guiding framework to ensure that every time a process is performed the same information, method, skills and controls are used and practiced in a consistent manner. With its primary focus being the involvement of everyone, TQM has the potential to improve business results, greater customer orientation and satisfaction, worker involvement and fulfilment, teamworking and better management of workers within companies. However, the construction industry has been slow to embrace the concept of TQM. Construction firms have been continually struggling with its implementation. Historically, construction has been an industry reluctant to implement change. Consequently, it has remained behind where it should be on the implementation of TQM. Generally, the principles of TQM are not applied beyond management levels within general contractors. This paper reports on a study to identify those factors that hinder the implementation of TQM principles in the actual field operations of a construction jobsite.
The implementation of TQM philosophy in Palestinian organization: a proposed non‐prescriptive generic framework
Authors: Baidoun Samir
Published: May 2004

The non‐prescriptive framework described in this paper is based on an empirical study of total quality management (TQM) implementation in the Palestinian industrial context. The main focus of the study was to identify the critical quality factors for effective TQM implementation and to understand how these critical quality factors are implemented by the Palestinian organizations. It is believed that the successful implementation of TQM in the Palestinian context should be a gradual approach with progression and selection of appropriate major top management actions. Therefore, a logical and simple framework based on the empirical evidence derived from the analysis of three levels of investigations is provided including the major top management actions, the organizational activities and the guidelines that need to be taken when addressing the foundation elements and the core components (critical quality factors) for successful implementation.
An application case of the Brazilian National Quality Award
Authors: Cauchick Miguel P.A. , Morini C. , Pires S.R.I.
Published: May 2004

The objective of this work consists of highlighting some benchmarking practices in management by presenting a case study conducted in a company in Brazil. The company was awarded with the Brazilian National Award some years back and it still can be considered as a benchmark of manufacturing enterprises. This paper focuses on the criteria of the National Foundation for Quality Award in Brazil by outlining the award process and presenting the core values and performance excellence criteria. Then, some current management practices in the studied company are presented. Finally, it is expected that the company is going to apply for the prize once again, expecting to be successful.
Leadership as Relationship
Authors: POPPER MICHA
Published: May 2004

The article reviews the various ramifications in the discussion on leadership, focusing on the view of leadership as relationships between leaders and followers. Three main types of leader‐follower relations are discussed, and their specific characteristics are described: regressive relations, symbolic relations, and developmental relations. After analyzing the major implications, as well as the conceptual limitations, of these perspectives, the article suggests directions for a more integrative conceptualization of leader‐follower relations.
Rethinking Crowd Violence: Self‐Categorization Theory and the Woodstock 1999 Riot
Authors: VIDER STEPHEN
Published: May 2004

According to self‐categorization theory (SCT), incidents of crowd violence can be understood as discrete forms of social action, limited by the crowd's social identity. Through an analysis of the riot at Woodstock 1999, this paper explores the uses and limitations of SCT in order to reach a more complex psychology of crowd behavior, particularly those instances that appear unmotivated, irrational, and destructive. Psychological and sociological literature are synthesized to explore the role of communication in establishing social norms within the crowd. Several modifications to current crowd psychology are proposed, including a false consensus effect of motivation and the mediation of personal and social identities.
Freedom and Rationality
Authors: VOLLMER FRED
Published: May 2004

The question discussed in the present paper is whether actions that are free can be thought of as rational. According to one view, no free action could be rational. According to another, all free actions must be rational. I argue that both these positions are false and that there is no necessary connection between freedom and rationality. Some free actions are rational, others are not.
An Ecological Approach to Semiotics
Authors: WINDSOR W. LUKE
Published: May 2004

This paper proposes an ecological approach to the perception and interpretation of signs. The theory draws upon the ecological approach of James Gibson (1966; 1979). It is proposed that cultural and natural perception can both be explained in terms of the direct pick‐up of structured information and the Gibsonian concept of affordances (Gibson, 1979) without having to invoke a sharp distinction between direct and indirect perception. The application of the theory is exemplified through attention to language and to the visual and audio arts.
Initial Response of Butterflies to an Overstory Reduction and Slash Mulching Treatment of a Degraded Piñon‐Juniper Woodland
Authors: Kleintjes P. K. , Jacobs B. F. , Fettig S. M.
Published: May 2004

Overstory reduction and slash mulching (ORSM) has been shown to be an effective means for increasing herbaceous cover and diversity in degraded piñon (Pinus edulis) and juniper (Juniperus monosperma) woodlands of north‐central New Mexico. Local fire history, tree age‐class structure, and grazing records suggest that many areas now occupied by dense piñon‐juniper woodlands were formerly more open, with grassy understories that supported well‐developed soils and a fire regime. At Bandelier National Monument, studies are evaluating the use of ORSM treatments as a restoration management tool. In 1999 and 2001, we evaluated the effects of an ORSM treatment implemented in 1997 upon butterfly abundance and species richness between a pair of treated and control watersheds. Butterfly abundance and species richness were significantly greater on the treated watershed in both years, and these measures were correlated with significant increases in forb and grass cover in the treated watershed. Five of the 10 most common nectar and larval host plants had significantly greater cover in the treated watershed, including the legume Lotus wrightii. Our results suggest that the increased herbaceous cover resulting from an ORSM treatment of a single watershed induced a positive, initial response by butterflies. Using butterflies as indicators of site productivity and species richness, our results suggest ORSM is a promising technique for restoring biodiversity in degraded piñon‐juniper woodlands.
Native Alternatives for Non‐Native Turfgrasses in Central Florida: Germination and Responses to Cultural Treatments
Authors: Jenkins Amy M. , Gordon Doria R. , Renda Michael T.
Published: May 2004

Little information exists about the establishment of native longleaf pine flatwoods species for use in restoration efforts and as buffers around natural areas in the southeastern United States. Composition of groundcover in these systems is dominated by perennial graminoid species. Vegetation in current buffers is generally non‐native turfgrass that can escape into natural areas, often reducing establishment and survival of native species. Where management objectives involve actively restoring native groundcover or reducing the probability of invasion by these non‐native turfgrasses, identification of native species and restoration methods is needed. We investigated seed germination and establishment of four species native to longleaf pine flatwoods in central Florida and one species native to the adjacent wetland communities. Paspalum setaceum, Panicum anceps, Eustachys petraea, and Eragrostis refracta were directly seeded, and P. distichum was planted as sprigs into three former P. notatum pastures. Irrigation, fertilization, weed control, and mowing treatments were assessed in terms of cover development of the sown species. Paspalum distichum developed the highest percent cover—over 80% in wet areas after 1 year. Mowing had mixed impacts depending on the species, and fertilization never significantly increased cover. Directly seeded species developed sparse cover (0–40%), probably as a result of drought conditions. However, E. petraea and E. refracta appeared more promising for use on rights‐of‐way when using high sowing rates. A second experiment conducted on a roadside included these two species and sprigged P. distichum. Both E. petraea and P. distichum developed more than 45% cover on the roadside. Establishment of these natives from seed or sprigs was significantly enhanced when site preparation effectively reduced the seedbank of other species present in the soil.
Seven‐Year Results of Thinning and Burning Restoration Treatments on Old Ponderosa Pines at the Gus Pearson Natural Area
Authors: Wallin Kimberly F. , Kolb Thomas E. , Skov Kjerstin R. , Wagner Michael R.
Published: May 2004

AbstractWe examined the 7‐year effects of three restoration treatments on leaf physiology and insect‐resistance characteristics of pre‐settlement age ponderosa pines (Pinus ponderosaDougl. ex Laws.) at the Gus Pearson Natural Area (GPNA) in northern Arizona. Restoration treatments were: (1) thinned in 1993 to approximate pre‐Euro‐American settlement stand structure, (2) thinned plus prescribed burned in 1994 and 1998, and (3) untreated control. Tree physiological and insect‐resistance characteristics were measured in year 2000, 7 years after thinning, using the same procedures as an earlier study performed in 1996. Consistent with the 1996 results, pre‐dawn water potential in 2000 was consistently lower in the control than both thinned treatments. Both thinned treatments continued to have increased foliar nitrogen concentration in leaves 7 years after treatment. However lower leaf nitrogen concentration in the thinned and burned compared with the thinned treatment suggests lower nitrogen availability to trees in repeatedly burned plots. Analysis of leaf gas exchange characteristics and carbon isotope content (δ13C) suggests continued stimulation of photosynthesis by both thinning treatments. Differences among treatments in resin volume, a measure of bark beetle resistance, depended on season of measurement. Trees in both thinning treatments continued to have increased leaf toughness, a measure of resistance to insect folivores. Our results show that many beneficial effects of restoration treatments on carbon, water, and nitrogen relations and insect‐resistance characteristics of pre‐settlement ponderosa pines continue to be expressed 7 years after treatment at the GPNA.
Effects of an Intense Prescribed Forest Fire: Is It Ecological Restoration?
Authors: Fulé Peter Z. , Cocke Allison E. , Heinlein Thomas A. , Covington W. Wallace
Published: May 2004

Relatively intense burning has been suggested as a possible alternative to the restoration of pre‐European settlement forest conditions and fire regime in mixed conifer forests, in contrast to thinning of trees and light prescribed burning. In 1993 a management‐ignited fire in a dense, never‐harvested forest in Grand Canyon National Park escaped prescription and burned with greater intensity and severity than anticipated. We sampled the burned site and an adjacent unburned site (270 ha each) 6 years after the fire to assess burn effects on tree structure (species composition, size and age distributions, regeneration, and snags), forest floor fuels, and coarse woody debris. Tree structure before fire‐regime disruption (1879 CE) was reconstructed with dendroecological techniques. By 6 years after burn the fire reduced average tree density (331 trees/ha) and basal area (28.5 m2/ha) to levels similar to pre‐European reference conditions (approximately 246 trees/ha and 28.5 m2/ha). Mortality was concentrated in fire‐susceptible species, especially white fir, restoring dominance by fire‐resistant ponderosa pine. Forest floor fuels were reduced, and regeneration by aspen and understory plants was vigorous. Densities of large snags and logs were high. However the fire also killed a high proportion of old‐growth trees, especially aspen. Burning created more spatial variability in forest structure than was present before fire‐regime disruption by killing many trees in some areas of the site but few in other areas. The intentional use of severe burning would be challenging to managers because of the increased risk of escaped fires, but the ecological outcome of this particular wildfire was not inconsistent with ecological restoration goals for this ecosystem type.
Effects of Sewage Sludge on Plant Community Composition in Restored Limestone Quarries
Authors: Moreno‐Peñaranda Raquel , Lloret Francisco , Alcañiz Josep M.
Published: May 2004

The effects of sewage sludge, used to improve fertility of replaced soil, on vegetation were studied in limestone quarry restoration. Plant community growing in the first stages after sludge application was surveyed in six quarries of NE Spain. Areas with a mixture of sewage sludge and residual soil were compared to areas where the application consisted only of residual soil (a mixture of previous top soil and mine spoils). Sewage sludge was hypothesized to increase total biomass and cover, modifying species composition and delaying the early successional recover of the community. The results showed that both biomass and plant cover increased because of sewage sludge addition. The floristic composition was dominated by ruderal species that did not show any dependence on sewage sludge application. Convergence on similarity between sludge and control plots was not detected along a 5‐year period. Although species richness was significantly lower in sludge plots, diversity and equitability indexes did not show differences between treatments. The results did not show differences in the proportion of non‐native species. The proportion of legumes was lower in sludge plots. These results show that the plant communities resulting from the addition of sewage sludge to the soil used in limestone quarry restoration have more biomass and cover, but less number of species, and they do not show a clear trend to converge to those areas restored only with non‐amended soil.
Revegetation Methods for High‐Elevation Roadsides at Bryce Canyon National Park, Utah
Authors: Petersen S. L. , Roundy B. A. , Bryant R. M.
Published: May 2004

Establishment of native plant populations on disturbed roadsides was investigated at Bryce Canyon National Park (BCNP) in relation to several revegetation and seedbed preparation techniques. In 1994, the BCNP Rim Road (2,683–2,770 m elevation) was reconstructed resulting in a 23.8‐ha roadside disturbance. Revegetation comparisons included the influence of fertilizer on plant establishment and development, the success of indigenous versus commercial seed, seedling response to microsites, methods of erosion control, and shrub transplant growth and survival. Plant density, cover, and biomass were measured 1, 2, and 4 years after revegetation implementation (1995–1998). Seeded native grass cover and density were the highest on plots fertilized with nitrogen and phosphorus, but by the fourth growing season, differences between fertilized and unfertilized plots were minimal. Fertilizers may facilitate more rapid establishment of seeded grasses following disturbance, increasing soil cover and soil stability on steep and unstable slopes. However the benefit of increased soil nutrients favored few of the desired species resulting in lower species richness over time compared to unfertilized sites. Elymus trachycaulus (slender wheatgrass) plants raised from indigenous seed had higher density and cover than those from a commercial seed source 2 and 4 years after sowing. Indigenous materials may exhibit slow establishment immediately following seeding, but they will likely persist during extreme climatic conditions such as cold temperatures and relatively short growing seasons. Seeded grasses established better near stones and logs than on adjacent open microsites, suggesting that a roughened seedbed created before seeding can significantly enhance plant establishment. After two growing seasons, total grass cover between various erosion‐control treatments was similar indicating that a variety of erosion reduction techniques can be utilized to reduce erosion. Finally shrub transplants showed minimal differential response to fertilizers, water‐absorbing gels, and soil type. Simply planting and watering transplants was sufficient for the greatest plant survival and growth.
An Analysis of Vegetation Restoration on Opencast Oil Shale Mines in Estonia
Authors: Pensa Margus , Sellin Arne , Luud Aarne , Valgma Ingo
Published: May 2004

We compared four types of 30‐year‐old forest stands growing on spoil of opencast oil shale mines in Estonia. The stand types were: (1) natural stands formed by spontaneous succession, and plantations of (2) Pinus sylvestris (Scots pine), (3) Betula pendula (silver birch), and (4) Alnus glutinosa (European black alder). In all stands we measured properties of the tree layer (species richness, stand density, and volume of growing stock), understory (density and species richness of shrubs and tree saplings), and ground vegetation (aboveground biomass, species richness, and species diversity). The tree layer was most diverse though sparse in the natural stands. Understory species richness per 100‐m2 plot was highest in the natural stand, but total stand richness was equal in the natural and alder stands, which were higher than the birch and pine stands. The understory sapling density was lower than 50 saplings/100 m2 in the plantations, while it varied between 50 and 180 saplings/100 m2 in the natural stands. Growing stock volume was the least in natural stands and greatest in birch stands. The aboveground biomass of ground vegetation was highest in alder stands and lowest in the pine stands. We can conclude that spontaneous succession promotes establishment of diverse vegetation. In plantations the establishment of diverse ground vegetation depends on planted tree species.