bluuebunny/crossref_metadata_2025 huggingface dataset:
Protein Kinase Activation Increases Insulin Secretion by Sensitizing the Secretory Machinery to Ca2+
Authors: Wan Qun-Fang , Dong Yongming , Yang Hua , Lou Xuelin , Ding Jiuping , Xu Tao
Published: November 2004

Glucose and other secretagogues are thought to activate a variety of protein kinases. This study was designed to unravel the sites of action of protein kinase A (PKA) and protein kinase C (PKC) in modulating insulin secretion. By using high time resolution measurements of membrane capacitance and flash photolysis of caged Ca2+, we characterize three kinetically different pools of vesicles in rat pancreatic β-cells, namely, a highly calcium-sensitive pool (HCSP), a readily releasable pool (RRP), and a reserve pool. The size of the HCSP is ∼20 fF under resting conditions, but is dramatically increased by application of either phorbol esters or forskolin. Phorbol esters and forskolin also increase the size of RRP to a lesser extent. The augmenting effect of phorbol esters or forskolin is blocked by various PKC or PKA inhibitors, indicating the involvement of these kinases. The effects of PKC and PKA on the size of the HCSP are not additive, suggesting a convergent mechanism. Using a protocol where membrane depolarization is combined with photorelease of Ca2+, we find that the HCSP is a distinct population of vesicles from those colocalized with Ca2+ channels. We propose that PKA and PKC promote insulin secretion by increasing the number of vesicles that are highly sensitive to Ca2+.
On the Importance of Atomic Fluctuations, Protein Flexibility, and Solvent in Ion Permeation
Authors: Allen Toby W. , Andersen O.S. , Roux Benoit
Published: November 2004

Proteins, including ion channels, often are described in terms of some average structure and pictured as rigid entities immersed in a featureless solvent continuum. This simplified view, which provides for a convenient representation of the protein's overall structure, incurs the risk of deemphasizing important features underlying protein function, such as thermal fluctuations in the atom positions and the discreteness of the solvent molecules. These factors become particularly important in the case of ion movement through narrow pores, where the magnitude of the thermal fluctuations may be comparable to the ion pore atom separations, such that the strength of the ion channel interactions may vary dramatically as a function of the instantaneous configuration of the ion and the surrounding protein and pore water. Descriptions of ion permeation through narrow pores, which employ static protein structures and a macroscopic continuum dielectric solvent, thus face fundamental difficulties. We illustrate this using simple model calculations based on the gramicidin A and KcsA potassium channels, which show that thermal atomic fluctuations lead to energy profiles that vary by tens of kcal/mol. Consequently, within the framework of a rigid pore model, ion-channel energetics is extremely sensitive to the choice of experimental structure and how the space-dependent dielectric constant is assigned. Given these observations, the significance of any description based on a rigid structure appears limited. Creating a conducting channel model from one single structure requires substantial and arbitrary engineering of the model parameters, making it difficult for such approaches to contribute to our understanding of ion permeation at a microscopic level.
KCNE3 Truncation Mutants Reveal a Bipartite Modulation of KCNQ1 K+ Channels
Authors: Gage Steven D. , Kobertz William R.
Published: November 2004

The five KCNE genes encode a family of type I transmembrane peptides that assemble with KCNQ1 and other voltage-gated K+ channels, resulting in potassium conducting complexes with varied channel-gating properties. It has been recently proposed that a triplet of amino acids within the transmembrane domain of KCNE1 and KCNE3 confers modulation specificity to the peptide, since swapping of these three residues essentially converts the recipient KCNE into the donor (Melman, Y.F., A. Domenech, S. de la Luna, and T.V. McDonald. 2001. J. Biol. Chem. 276:6439–6444). However, these results are in stark contrast with earlier KCNE1 deletion studies, which demonstrated that a COOH-terminal region, highly conserved between KCNE1 and KCNE3, was responsible for KCNE1 modulation of KCNQ1 (Tapper, A.R., and A.L. George. 2000 J. Gen. Physiol. 116:379–389.). To ascertain whether KCNE3 peptides behave similarly to KCNE1, we examined a panel of NH2- and COOH-terminal KCNE3 truncation mutants to directly determine the regions required for assembly with and modulation of KCNQ1 channels. Truncations lacking the majority of their NH2 terminus, COOH terminus, or mutants harboring both truncations gave rise to KCNQ1 channel complexes with basal activation, a hallmark of KCNE3 modulation. These results demonstrate that the KCNE3 transmembrane domain is sufficient for assembly with and modulation of KCNQ1 channels and suggests a bipartite model for KCNQ1 modulation by KCNE1 and KCNE3 subunits. In this model, the KCNE3 transmembrane domain is active in modulation and overrides the COOH terminus' contribution, whereas the KCNE1 transmembrane domain is passive and reveals COOH-terminal modulation of KCNQ1 channels. We furthermore test the validity of this model by using the active KCNE3 transmembrane domain to functionally rescue a nonconducting, yet assembly and trafficking competent, long QT mutation located in the conserved COOH-terminal region of KCNE1.
On the 𝑝^{𝑒}-torsion of elliptic curves and elliptic surfaces in characteristic 𝑝
Authors: Schweizer Andreas
Published: December 2004

We study the extension generated by the

x
x

-coordinates of the

p
e

p^e

-torsion points of an elliptic curve over a function field of characteristic

p
p

. If

S
→
C

S\to C

is a non-isotrivial elliptic surface in characteristic

p
p

with a

p
e

p^e

-torsion section, then for

p
e

>
11

p^e>11

our results imply restrictions on the genus, the gonality, and the

p
p

-rank of the base curve

C
C

, whereas for

p
e

≤
11

p^e\le 11

such a surface can be constructed over any base curve

C
C

. We also describe explicitly all occurring

p
e

p^e

in the cases where the surface

S
S

is rational or

K
3

K3

or the base curve

C
C

is rational, elliptic or hyperelliptic.
Harmonic maps 𝐌³→𝐒¹ and 2-cycles, realizing the Thurston norm
Authors: Katz Gabriel
Published: December 2004

Let

M
3

M^3

be an oriented 3-manifold. We investigate when one of the fibers or a combination of fiber components,

F

b
e
s
t

F_{best}

, of a harmonic map

f
:

M
3

→

S
1

f: M^3 \rightarrow S^1

with Morse-type singularities delivers the Thurston norm

χ
−

(
[

F

b
e
s
t

]
)

\chi _-([F_{best}])

of its homology class

[

F

b
e
s
t

]
∈

H
2

(

M
3

;

Z

)

[F_{best}] \in H_2(M^3; \mathbb {Z})

. In particular, for a map

f
f

with connected fibers and any well-positioned oriented surface

Σ
⊂
M

\Sigma \subset M

in the homology class of a fiber, we show that the Thurston number

χ
−

(
Σ
)

\chi _-(\Sigma )

satisfies an inequality
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="chi Subscript minus Baseline left-parenthesis normal upper Sigma right-parenthesis greater-than-or-equal-to chi Subscript minus Baseline left-parenthesis upper F Subscript b e s t Baseline right-parenthesis minus rho Superscript ring Baseline left-parenthesis normal upper Sigma comma f right-parenthesis dot upper V a r Subscript chi Sub Subscript minus Subscript Baseline left-parenthesis f right-parenthesis period">

χ
−

(
Σ
)
≥

χ
−

(

F

b
e
s
t

)
−

ρ
∘

(
Σ
,
f
)
⋅
V
a

r

χ
−

(
f
)
.

\chi _-(\Sigma ) \geq \chi _-(F_{best}) - \rho ^\circ (\Sigma , f)\cdot Var_{\chi _-}(f).

\]
Here the variation

V
a

r

χ
−

(
f
)

Var_{\chi _-}(f)

is can be expressed in terms of the

χ
−

\chi _-

-invariants of the fiber components, and the twist

ρ
∘

(
Σ
,
f
)

\rho ^\circ (\Sigma , f)

measures the complexity of the intersection of

Σ
\Sigma

with a particular set

F
R

F_R

of “bad" fiber components. This complexity is tightly linked with the optimal “

f
~

\tilde f

-height" of

Σ
\Sigma

, being lifted to the

f
f

-induced cyclic cover

M
~

3

→

M
3

\tilde M^3 \rightarrow M^3

. Based on these invariants, for any Morse map

f
f

, we introduce the notion of its twist

ρ

χ
−

(
f
)

\rho _{\chi _-}(f)

. We prove that, for a harmonic

f
f

, 

χ
−

(
[

F

b
e
s
t

]
)
=

χ
−

(

F

b
e
s
t

)

\chi _-([F_{best}]) = \, \chi _-(F_{best})

if and only if

ρ

χ
−

(
f
)
=
0

\rho _{\chi _-}(f) = 0

.
The number of certain integral polynomials and nonrecursive sets of integers, Part 2
Authors: Friedman Harvey
Published: December 2004

We present some examples of mathematically natural nonrecursive sets of integers and relations on integers by combining results from Part 1, from recursion theory, and from the negative solution to Hilbert’s 10th Problem.
Modelling the Groove: Conceptual Structure and Popular Music
Authors: Zbikowski Lawrence M.
Published: November 2004

A musical groove is most typically created by a small group of musicians working together, each contributing parts to the whole. Characterizing the knowledge behind such interactive ventures has proved to be challenging. This article attempts to characterize the knowledge basic to grooves first by concentrating on ‘the groove’ as it is practised in soul, rhythm and blues, jazz fusion and various other popular genres, and second by focusing on cognitive knowledge structures called conceptual models. It is argued that musicians rely on such structures to produce grooves, and that listeners make use of similar structures to understand them. Grooves from the music of Eric Clapton, Miles Davis and James Brown are discussed, and conceptual models for each are developed.
Resistance of flight feathers to mechanical fatigue covaries with moult strategy in two warbler species
Authors: Weber Thomas P , Borgudd Johan , Hedenström Anders , Persson Kent , Sandberg Göran
Published: November 2004

Flight feather moult in small passerines is realized in several ways. Some species moult once after breeding or once on their wintering grounds; others even moult twice. The adaptive significance of this diversity is still largely unknown. We compared the resistance to mechanical fatigue of flight feathers from the chiffchaffPhylloscopus collybita, a migratory species moulting once on its breeding grounds, with feathers from the willow warblerPhylloscopus trochilus, a migratory species moulting in both its breeding and wintering grounds. We found that flight feathers of willow warblers, which have a shaft with a comparatively large diameter, become fatigued much faster than feathers of chiffchaffs under an artificial cyclic bending regime. We propose that willow warblers may strengthen their flight feathers by increasing the diameter of the shaft, which may lead to a more rapid accumulation of damage in willow warblers than in chiffchaffs.
Community response to enrichment is highly sensitive to model structure
Authors: Fussmann Gregor F , Blasius Bernd
Published: November 2004

Biologists use mathematical functions to model, understand and predict nature. For most biological processes, however, the exact analytical form is not known. This is also true for one of the most basic life processes: the uptake of food or resources. We show that the use of several nearly indistinguishable functions, which can serve as phenomenological descriptors of resource uptake, may lead to alarmingly different dynamical behaviour in a simple community model. More specifically, we demonstrate that the degree of resource enrichment needed to destabilize the community dynamics depends critically on the mathematical nature of the uptake function.
Responsibility and punishment: whose mind? A response
Authors: Zeki S. , Goodenough O. R. , Goodenough Oliver R.
Published: November 2004

Cognitive neuroscience is challenging the Anglo-American approach to criminal responsibility. Critiques, in this issue and elsewhere, are pointing out the deeply flawed psychological assumptions underlying the legal tests for mental incapacity. The critiques themselves, however, may be flawed in looking, as the tests do, at the psychology of the offender. Introducing the strategic structure of punishment into the analysis leads us to consider the psychology of the punisher as the critical locus of cognition informing the responsibility rules. Such an approach both helps to make sense of the counterfactual assumptions about offender psychology embodied in the law and provides a possible explanation for the human conviction of the existence of free will, at least in others.
Preface
Authors: Zeki S. , Goodenough O. R. , Bingham Tom
Published: November 2004

The legal process is often invoked to resolve scientific or economic problems such as may arise when a bridge collapses, or an aeroplane crashes, or a ship sinks; or when a mishap occurs on the operating table; or when patent protection is sought for an invention claimed to be novel; or when it is necessary to assess the effect of a commercial practice on competition in a market; or when a baby dies, for no apparent reason, in its cot; or when it is sought to identify a fingerprint on a murder weapon.
The standardisation of construction snagging
Authors: Sommerville James , Craig Nigel , Bowden Sarah
Published: November 2004

Construction projects have become larger and more complex and yet still maintain a high drive for quality. As a result of this increase in size and complexity, the quantities of documentation and information required to control the overall project process have themselves become more complex. Underpinning the goal of construction quality is real time information flow to and from the construction site along with communications between all the parties involved. Project information integration and collaboration is the key to achievement of coherent quality management and this can be attained through electronically sharing of information during the construction process. The residential sector of the construction industry continually experiences significant numbers of “snags”. Many site issues including snagging need to be resolved quickly and efficiently to avoid dispute and more importantly cost overrun. However, the distinct professions and artisans within the industry rarely acknowledge the needs of others. Indeed the snagging information they produce is often so incompatible that the next stage in many processes is to reconstruct the information into a workable format. Analysis of a range of organisations' approaches to snagging shows that they have their own distinct snagging process. What is required is a coherent approach to the use and implementation of an IT based, industry wide, snagging format which would revolutionise and streamline the recording and approval process of construction snagging.
Moments of trust: temporal and spatial factors of trust in organizations
Authors: Rämö Hans
Published: November 2004

Different forms of trust in the contemporary organizational settings of virtual organizations and time management (e.g., just‐in‐time, lean production, and total quality management) are discussed in conjunction with some Greek philosophical notions of human action, namelytheoria/episteme,poiesis/techne, andpraxis/phronesis, together with the two notions of time,chronos/kairosand their spatial counterparts,chora/topos. It is suggested that time management concepts in production line settings are frequently based upon asymmetric power‐relations and rigid time‐control making most forms of organizational trust instrumental and/or weak. Virtual organization settings, on the other hand, are more likely to contain trust that appears to be fragile and temporal, and in demand of communication based on right moments to act judiciously.
Changing a cultural grammar?
Authors: Pina E. Cunha Miguel , Campos E. Cunha Rita
Published: November 2004

This study investigates one of the multiple aspects involved in the transfer of management knowledge between countries: the transfer of timeframes. More than an objective and macro‐level variable to be managed, time is analyzed from the perspective of the individual experiences of a sample of managers located in Portugal. Portugal, together with the other Southern‐European cultures, has been presented as a polychronic culture. The Southern, polychronic timeframe, however is being openly criticized by managers, both Portuguese and foreign, on the basis of “time as money” assumption. The articulation of the macro and micro levels of analysis showed that the dialectical opposition between Northern and Southern times is being interpreted under three main perspectives: Latin time is deeply entrenched and difficult to change but is dysfunctional; time management in the Northern time is part of the good manager “toolkit” and hence must replace Southern time; a synthesis must be found to articulate in some virtuous manner the two previous perspectives. The paper contributes to the literature with an articulation between the macro level (national and occupational identity) and the micro perspective (the lived experience of time). It also contributes to the under‐researched aspect of management in Southern Europe.
Perceptions and experience of time‐space compression and acceleration
Authors: Turnbull Sharon
Published: November 2004

This research builds on Jenkins' theory of time, identification and human nature through an empirical study of leaders' experiences in a large UK public sector organisation. By applying Lewis and Weigart's typology of social time to the accounts of the leaders studied within this research, the study finds that the leaders' self‐ identities are constituted through the discourses of self‐time, interaction‐time and organisational‐time which are embedded, stratified and synchronised through social and organisational practices. In the leaders' narratives of career, work, life and family the research identifies dominant discourses of time compression and acceleration, as well as both cyclic and linear discourses of time. Each of these temporal constructs is found to be embedded in and manifested through the continuous construction and shaping of identity. The implications of these findings for our understanding of the contemporary working life of leaders and their careers and identities are discussed.
Virtual teams: team control structure, work processes, and team effectiveness
Authors: Piccoli Gabriele , Powell Anne , Ives Blake
Published: November 2004

Seeks to determine the impact managerial controls have on the effectiveness of virtual teams. Using an experimental design compares self‐directed virtual teams to counterparts where behavior controls are used as a method of managerial control. The data were collected using 51 student teams of three or four members each from three different countries. The results indicate that the most satisfied team members were in virtual teams with effective coordination and communication. Members of self‐directed virtual teams report higher individual satisfaction with the team and project, while different control structures had no significant impact on virtual team performance. Future research should investigate how these findings generalize to organizational workers, rather than just looking at students. This paper is just a first step investigating one type of managerial control: behavior controls. The small amount of research that has been published on virtual teams has primarily concentrated on self‐directed teams. This paper compares results of team effectiveness by looking at both self‐directed virtual teams and virtual teams with behavioral controls enforced.
On the emancipatory role of rural information systems
Authors: Kanungo Shivraj
Published: November 2004

The use of information technology in rural and underserved settings is receiving increasing attention because of the immense potential it brings for improving the quality of life and reducing the digital divide. However, high costs coupled with infrastructure and context‐related inhibitors tend to dilute the advantages that are often taken as a set of givens. In this paper we present a case study of a pioneering experience of information system use in a set of villages in southern India. The research proposition for this study is that social processes can form a viable basis for providing sustainability to information communications technology (ICT) initiatives in rural regions. Theoretical support for this study comes from Habermas’ theory of communicative action. Given that such information systems are emancipatory in nature, and given that such information systems face many obstacles, the value added by these systems needs to be assessed in terms of their contribution to social capital in addition to economic value added. Our analysis reveals that social processes can be leveraged to accord viability to ICT setups in rural settings. Many social changes, that may have faced resistance or were unexpected, themselves became the reason for keeping the ICT setup. This is so because these changes form the basis of empowerment and a participatory framework that would have been absent earlier. We provide implications for researchers as well as practitioners.
Brand alliance dependency and exclusivity: an empirical investigation
Authors: Rodrigue Christina S. , Biswas Abhijit
Published: November 2004

This paper examines the effects of resource dependency and contract exclusivity on the attitudes and intentions of consumers in brand alliances. Findings indicate that attitudes of the brands before the alliance (pre‐attitudes) have a positive effect on the attitude toward the alliance, which has a positive effect on perceived quality of the alliance, willingness to pay a premium price and purchase intention. Further, attitudes toward the brands after the alliance (post‐attitudes) reveal a positive spillover effect for both the host and ally brands. Interestingly, the moderating effects of dependency and exclusivity differ based on whether the brand serves as the host or the ally brand in the alliance. Analyses conducted after controlling for the effects of familiarity of the ally brands revealed consistent results.
Citizen expectations of police traffic stop behavior
Authors: Johnson Richard R.
Published: November 2004

The most frequent type of citizen complaint filed against police officers involves how the officer uses interpersonal communication. The most common context of police‐citizen contact is the traffic stop, and verbal judo is the most widely used police training program in interpersonal communication intended to reduce citizen complaints and improve citizen cooperation. However, does verbal judo meet citizen expectations for appropriate traffic stop behavior? In order to determine what communication behaviors citizens view as appropriate during traffic stops, a sample of 245 college students were surveyed about their preferences with regard to the officers' behavior. The responses of the sample support the use of verbal judo techniques during routine traffic stops. The responses also demonstrated support for the theory of procedural justice.
Human rights in the new training curriculum of the Police Service of Northern Ireland
Authors: Engel Steven T. , Burruss George W.
Published: November 2004

Northern Ireland is attempting to move from a divided society model of policing to a democratic policing model. One of the key components of the reform agenda is the issue of human rights. A key test of the attempt to place human rights at the forefront of the reforms is the attempt to integrate human rights into every aspect of police training. In this article, the new training curriculum of the Police Service of Northern Ireland is examined to determine whether and how human rights are being integrated into the training modules in an effort to better understand the dimensions of democratic police reforms. Field observations of training sessions indicate that a holistic approach to human rights is being employed in addition to a legalistic approach.
Structural and organizational predictors of homicide by police
Authors: Smith Brad W.
Published: November 2004

The present study examined homicides by police officers, testing threat, community violence, and organizational hypotheses. Using UCR, SHR, Census, and LEMAS data the study extends previous research by examining the relative impact of community violence, inequality and race, and organizational characteristics on the number of killings of felons by police officers in large US cities. The findings show that measures of racial threat and community violence were related to police killings. Measures of organizational policies were largely unrelated to the number of police killings. Overall the study extends research in the area, yet it also points to a more general need for research on the effects of organizational factors on police violence.
The role of police visibility in fear of crime in Finland
Authors: Salmi Satu , Grönroos Martti , Keskinen Esko
Published: November 2004

This article presents a model for police visibility and people's fear of crime. Survey data were collected from 3,245 adults and 977 teenagers in two typical Finnish neighborhoods. A four‐factor model including two visibility factors (patrol‐car‐related activities and police‐on‐foot activities) and two fear of crime factors (crimes against property and crimes against persons) was constructed by structural equation modeling. Respondents who perceived the police more often in on‐foot activities were less fearful of crimes against property. In the teenagers' group, the same effect was found in relation to crimes against persons. In both groups, seeing the police more in patrol‐car‐related activities resulted in increased fear of crimes against persons and property. Our results indicate that a simple act for the police, such as stepping out of the car every now and then, i.e. not only in crime‐related situations, has a positive impact on the fear of crime as expressed by the public.
Czech police officers
Authors: Crow Matthew S. , O'Connor Shelley Tara , Bedard Laura E. , Gertz Marc
Published: November 2004

Following the velvet revolution of 1989 and the adoption of a democratic form of government, Czech policing has experienced a plethora of changes resulting in a new police force that has been understudied to date. This research seeks to address this void using an exploratory approach that utilizes survey research to gauge the attitudes of 70 Czech police officers regarding crime and criminal justice policies; police and government involvement in social and order maintenance problems; and police practices in the Czech Republic (e.g. community‐oriented policing). Several factors – historical, ideology and job tenure – are considered as potential explanations for observed trends in officer attitudes. The results indicate that there are no clear patterns to these officers' attitudes.
Scenarios and business models for 4G in Europe
Authors: Ballon Pieter
Published: November 2004

This paper investigates the main trends and uncertainties that will define fourth generation mobile systems and services (4G) in Europe. It outlines two divergent visions on 4G: the so‐called “immediate” 4G vision, consisting of wireless local area networks (WLANs) combined with other wireless access technologies, competing with 3G in the short term, and the so‐called “linear” 4G vision, in which the 3G standard is not replaced until the end of its life cycle by an ultra‐high speed broadband wireless network. Which of these visions will materialise, and what this means for the competitiveness of the main 4G stakeholders in Europe, will be to a large extent determined by which business models are feasible for 4G.
Modelling the strategy management process
Authors: Munive‐Hernandez E.J. , Dewhurst F.W. , Pritchard M.C. , Barber K.D.
Published: November 2004

Businesses face increasing competition in local, international and global markets where responsiveness to changes within these markets is the key to success and survival. Consequently business strategies need to be consistently re‐defined to effectively reflect the different requirements of customers and to respond to changes in the business environment. The process of generating strategies is not always a simple decision‐making task and revised business and corporate strategies are often generated without considering the structure of the business, particularly at operational level. Furthermore, there is considerable vagueness in the literature and in practice about what constitutes strategy management. This paper reviews the diverse literature in strategy management and presents a business process model of the strategy generation process to ensure consistent generation and communication of strategy throughout an organisation. The performance of a business strategy can then be measured against a model of initial alignment and effective implementation.
Intergenerational Transfers and Private Savings: an Experimental Study
Authors: Heijden Eline CM. van der , Nelissen Jan H.M. , Potters Jan J.M. , Verbon Harrie A.A.
Published: December 2004

This paper presents the results of an overlapping‐generations experiment on the individual choice between intergenerational transfers and savings. One dominant finding of our experiment is that if savings are possible individuals choose to (gradually) opt out of the intergenerational transfer system. In that case the average individual pay‐offs are lower but their distribution among individuals is less volatile. This suggests that risk aversion is a driving force behind the decline of intergenerational transfers. The willingness to give to previous generations does not disappear completely, however. Moreover, the degree of cohesion between successive generations, measured by (lie correlation between current and past transfers does not diminish significantly after the introduction of (he savings option.

ZUSAMMIENEASSUNG

Dicser Artikcl präsentierl die ErgebnisseeinesOvcrlapping‐Generations‐Experitnents, indent sich die Tcilnehmer zwisehen tnlergenerationalcn Transfers und Sparen entscheiden mussten. Eines der Hauptergcbnisse besteht darin, dass die Einführung der Mögliehkeit zur individuellen Zukunfts‐vorsorge durch Sparen zu einer (allmählichen) Zurückdrängung von intergencrationalen Transfers führt. Im Fall des Sparens isl die durehschnittliche individuclle Auszahlung zwar geringer, dafür aber weniger unsieher. Die Zurückdrangung intergenerationaler Transfers lässt sich dahcr durch Risikoaversion erklären. Dennoch verschwindct die Bereitschaft, an die vorausgehende Generation abzugeben, nicht völlig. Ausserdein vennindert sich die Stärke des Zusatnnienhalts zwisehen aufcinanderlolgcnden Generalionen, getnessen durch die Korrelation zwisehen gegenwärtigen und früheren Transfers, nicht wesentlich durch die Einführung der Mögliehkeit des Sparens.

Le papier présente des résultats expérimentaux sur les choix individuels entre transferts inter‐génération et épargnc. Un des résultats principaux est que s'il est possible d'épargncr, alors (progressivement) les agents passent du système de transfer! inter‐générationnelausystème d'épargne. Dans de cas le payoff moyen des agents est plus faible mais la distribution des payoffs est inoins volatile. Ceei suggère que l'aversion pour le risque est l'une des prineipales causes du déclin des transferts intergénération. Cependant, les transferts inter‐génération ne disparaissent pas totalement. De plus, le degré de cohesion entre les génération successives, mesuré par la corrélation entre les transferts présents et passés, ne diminue pas significativemenl apres l'introduction de la possibilityé d'épargncr.
Estimates of a Hedonic Ageing Equation for Partner Search
Authors: Cameron Samuel , Collins Alan
Published: December 2004

This paper presents the first attempts by economists to estimate an equation of the demand curve for sexual relationship partner attributes. The focus is on the age of partner sought as the item demanded. A sample of newspaper ‘personal ads' is used to construct the demand curve. The estimates show clear evidence of age trade offs in partner search which vary by gender. There is evidence that financially constrained men will trade down in terms of market desirability, i.e., up in partner age, but also that women will offer to buy younger partners with financial signalling.

Dieser Artikel präsentiert die ersten Versuche von Ökonomen, eine Gleichung für die Nachfragekurve nach Eigenschaften von Partnern bei der Partnersuche zu schätzen. Das Hauptinteresse liegt dabei auf dem Alter des Partners. Eine Stichprobe aus Kontaktanzeigen in Tageszeitungen dient dazu, die Nachfragekurve zu konstruieren. Die Schätzungen zeigen deutlich, dass Altersunterschiede bei der Partnersuche kompensiert werden müssen. So wurden Beweise dafür gefunden, dass Männer mit beschränkter finanzieller Ausstattung vom Markt weniger nachgefragt werden, also nur altere Partner finden, und Frauen versuchen, jüngere Partner durch finanzielle Anreize zu kaufen.

Cet article nous présente les premières tentatives faites par les économistes afin d'évaluer la courbe de dernande portant sur les caractéristiques du partenaire sexuel. L'accent est mis sur l'ǎge du partenaire recherché comme étant le critère essentiel. C'est grǎce à un échantillon de ‘petites annonces' parues dans les journaux que la courbe a été tracée. Ainsi les hommes ayant des contraintes financières se montreront plus conciliants quant à l'ǎge. En d'autres termes, ils accepteront des partenaires plus ǎgées tandis que les femmes jouissant des moyens financiers se proposeront d'acheter des partenaires plus jeunes.
Patient Demographics and Utilization of Health Care Services for Molluscum Contagiosum
Authors: Molino Arlene C. , Fleischer Alan B. , Feldman Steven R.
Published: November 2004

Abstract:  Our objective was to describe the demographics of molluscum contagiosum patients and physician utilization patterns in the United States. We obtained weighted data for office visits throughout the United States for molluscum contagiosum and common warts from the National Ambulatory Medical Care Survey (NAMCS) from 1990 to 1999. Outpatient visit data for patients diagnosed with molluscum contagiosum were analyzed using statistical software and compared to those for patients diagnosed with common warts. The main outcome measures studied were physician office visits by patients with molluscum contagiosum and patient demographic parameters including age, gender, and race. We found that health care utilization for molluscum contagiosum was the greatest for patients ≤9 years of age (51%). Ninety‐three percent of patients diagnosed with molluscum contagiosum were white. The number of visits for molluscum contagiosum was evenly divided between males and females. Visits to dermatologists comprised the majority of health care utilization units for molluscum contagiosum (71%). In conclusion, visits for molluscum contagiosum are frequent and are most often handled by dermatologists. When compared to those for common warts, molluscum contagiosum visits are less common and have an age distribution more limited to children.
Cutaneous Adverse Reactions to Hydroxyurea in Patients with Intermediate Thalassemia
Authors: Zargari Omid , Kimyai‐Asadi Arash , Jafroodi Maryam
Published: November 2004

Abstract:  Although the cutaneous effects of hydroxyurea have been described for patients with sickle cell anemia, myeloproliferative disorders, and psoriasis, there are no reports of cutaneous adverse effects from hydroxyurea when used for patients with intermediate thalassemia. Therefore 43 patients with intermediate thalassemia treated with hydroxyurea were examined by a dermatologist, and pertinent cutaneous findings were recorded. These patients had received hydroxyurea for a mean of 15.5 months. Nineteen had cutaneous hyperpigmentation, eight had xerosis, and three were found to have one café au lait macule each. Eleven patients had nail abnormalities, including nail ridging, partial leukonychia, and longitudinal melanonychia. There were no cases of leg ulceration. It was concluded that the risk of developing leg ulcers and pigmentary disorders appears to be related to the underlying disease being treated, as well as to a patient's age, gender, and pigmentation.
Effects of Prescribed Fire on Nutrient Pools and Losses from Glades Occurring Within Oak‐Hickory Forests of Central Kentucky
Authors: Trammell T. L. E. , Rhoades C. C. , Bukaveckas P. A.
Published: November 2004

Forest openings, also known as glades, arise through a variety of mechanisms including disturbance (fire and blow downs) and local variation in soil or bedrock geology. They are common in many forest types and are often dominated by locally rare herbaceous species. Prescribed burning is increasingly used as a management approach for maintaining glades although little is known about the effects of fire on these habitats. Of particular concern is the potential for nutrient loss during and after fire because glades are often characterized by nutrient‐poor soils. We quantitated nutrient losses through combustion and leaching for glade and adjacent forest habitats subjected to a prescribed burn. Our findings suggest that spring burns do not result in appreciable loss of nutrient capital from glades in comparison with those observed in the surrounding forest. Fire resulted in a substantial loss of litter mass (37%) in the forest but no measurable loss in the glade. Nitrogen losses through combustion were significant in the forest and were equivalent to 4.5 years of atmospheric inputs. Fire significantly increased soil nitrate pools in forest but not in glade plots. No detectable increases in nitrogen, phosphorus, or base cation leaching were observed in either forest or glade habitats within 4 months after the burn. These findings suggest that plant and microbial nutrient uptake rapidly reestablish control over leaching losses when burns are conducted at the start of the growing season. Biotic retention minimizes fire impacts on nutrient loss from the ecosystem.
Sensitivity of C Sequestration in ReintroducedSphagnumto Water‐Level Variation in a Cutaway Peatland
Authors: Tuittila Eeva‐Stiina , Vasander Harri , Laine Jukka
Published: November 2004

The reintroduction ofSphagnumfragments has been found to be a promising method for restoring mire vegetation in a cutaway peatland. Although it is known that moisture controlsSphagnumphotosynthesis, information concerning the sensitivity of carbon dynamics on water‐level variation is still scarce. In a 4‐year field experiment, we studied the carbon dynamics of reintroducedSphagnum angustifoliummaterial in a restored (rewetted) cutaway peatland. Cutaway peatland restored bySphagnumreintroduction showed high sensitivity to variation in water level. Water level controlled both photosynthesis and respiration. Gross photosynthesis (PG) had a unimodal response to water‐level variation with optimum level at −12 cm. The range of water level for highPG(above 60% of the maximum light‐saturatedPG) was between 22 and 1 cm below soil surface. Water level had a dual effect on total respiration. When the water level was below soil surface, peat respiration increased rapidly along the lowering water level until the respiration rate started to slow down at approximately −30 cm. Contrary to peat respiration, the response ofSphagnumrespiration to water‐level variation resembled that of photosynthesis with an optimum at −12 cm. In optimal conditions,Sphagnumreintroduction turned the cutaway site from carbon source to a sink of 23 g C/m2per season (mid‐May to the end of September). In dry conditions, lowered photosynthesis together with the higher peat respiration led to a net loss of 56 g C/m2. Although the water level above the optimum amplitude restricted CO2fixation, a decrease in peat respiration led to a positive CO2balance of 9 g C/m2.
Endangered Cactus Restoration: Mitigating the Non‐Target Effects of a Biological Control Agent (Cactoblastis cactorum) in Florida
Authors: Stiling Peter , Moon Daniel , Gordon Doria
Published: November 2004

The moth Cactoblastis cactorum (Berg), the poster child of weed biological control in Australia, has recently invaded the United States and threatens native cacti. Concern is greatest for the endangered semaphore cactus, Opuntia corallicola, of which only two known populations exist in the wild. We made three separate outplantings of O. corallicola, designed to bolster the number of extant cacti and to test the effectiveness of three different treatments to protect the cacti from Cactoblastis. In one outplanting, we tested the associational susceptibility hypothesis and found that cacti planted more than 20 m away from the common prickly pear cactus, Opuntia stricta, which act as a reservoir of Cactoblastis, were just as frequently attacked and killed by Cactoblastis as cacti planted within 5 m. In addition, Cactoblastis attack was greater in the shade than in the sun. In the second outplanting, we minimized the attack from Cactoblastis by using protective cages planted at least 500 m from O. stricta in areas not inhabited by cacti. Cages attracted the attention of local animals, which destroyed the cages and trampled the cacti inside to death. Crown rot caused high mortality in this outplanting. In the third outplanting, again conducted at least 500 m away from O. stricta, fertilization did not reduce crown rot mortality. We suggest that increasing populations of O. corallicola in Florida, by means of outplantings, will remain a challenge because of death from Cactoblastis when planted in areas where cacti normally grow and because of death from crown rot in areas where they do not. Because Cactoblastis is moving rapidly northward and westward and has already reached Charleston, South Carolina, rare cacti in the rest of the U.S. Southeast may be in danger. Eventually, many cactus species in the U.S. South, Southwest, and Mexico will likely be threatened by this moth.
Review article: indications for anti‐reflux surgery and endoscopic anti‐reflux procedures
Authors: Palmer K.
Published: December 2004

Gastro‐oesophageal reflux disease is a motor disorder principally caused by defective function of the lower oesophageal sphincter. Proton pump inhibitor (PPI) drugs alleviate symptoms, heal oesophagitis and improve quality of life but do not address the underlying motor disorder, and prolonged treatment is often needed. The efficacy of anti‐reflux operations is comparable to PPIs. Indications for surgical referral include ineffective medical therapy, intolerance to PPIs, the aspiration to avoid drugs and treatment of complications (particularly peptic stricture and respiratory diseases). Pre‐operative assessment should include endoscopy, pH monitoring and oesophageal manometry.

The efficacy of anti‐reflux surgery is well established but endoscopic anti‐reflux procedures currently have an uncertain role. These procedures are based on endoscopic suturing, injection of materials around the lower oesophageal sphincter and radio frequency ablation. Published series show that all procedures may be effective in selected patients. Although the mechanisms for this efficacy are unclear, they may include correction of the underlying motor defect, physical barrier to reflux and decreased oesophageal sensitivity caused by denervation. Comparative studies are needed before endoscopic anti‐reflux procedures can be recommended outside of clinical trials.
Review article: Helicobacter pylori and gastro‐oesophageal reflux disease − the European perspective
Authors: McColl K. E. L.
Published: December 2004

There is substantive epidemiological evidence of a negative association between Helicobacter pylori infection and reflux disease and its malignant complications. A plausible mechanism by which the infection might protect against reflux disease is by its propensity to produce atrophic gastritis and consequently reduce gastric acid secretion. Gastric acid is a key factor in the pathophysiology of reflux oesophagitis. It is well recognised that acid secretion decreases with age in H. pylori infected populations whereas acid secretion is maintained throughout life in H. pylori negative populations. The tendency for H. pylori infection to induce atrophy and reduce acid secretion is more marked in Eastern Europe and the Far East than in Western Europe, and this may be due to the influence of environmental and host genetic co‐factors. This difference may also explain why the negative association between H. pylori infection and reflux disease is more marked in these areas than in Western Europe. If H. pylori infection is indeed protecting against reflux disease, then one would predict a rise in incidence of this disease and its malignant complications in these Eastern countries as the incidence of H. pylori infection decreases.
Review article: influence of Helicobacter pylori on gastro‐oesophageal reflux disease in Japan
Authors: Haruma K.
Published: December 2004

There is circumstantial evidence that infection with Helicobacter pylori is relatively protective for the occurrence of gastro‐oesophageal reflux disease (GERD). It has been suggested that the Japanese population are protected against reflux oesophagitis by their high prevalence of H. pylori associated gastritis. Such gastritis, when becoming chronic, can lead to gastric atrophy, thereby reducing the likelihood of GERD. If this hypothesis is correct, the effects of H. pylori induced gastritis may be an important factor determining the earlier lower prevalence of oesophagitis in Japan, where this infection is especially common. In support of this idea a reduced prevalence of H. pylori infection in Japan, as is now being observed in young Japanese adults, may be, at least in part, responsible for the upsurge in the number of cases of reflux disease in Japan. Concomitantly, H. pylori eradication therapy in patients with gastritis or peptic ulcer disease, which is associated with an increase in gastric acid secretion, may also be at least partly responsible for the increased prevalence of reflux oesophagitis in the Japanese population.
Laparoscopy in the management of colorectal cancer metastatic to the liver
Authors: Koea Jonathan , Rodgers Michael , Thompson Paul , Woodfield John , Holden Andrew , McCall John
Published: December 2004

Background:  This investigation was undertaken to define the value of laparoscopy in the staging of patients with colorectal carcinoma metastatic to the liver.

Methods:  The clinical details of 59 consecutive patients with colorectal liver metastases undergoing laparoscopy prior to planned hepatectomy were entered prospectively on a computerized database. All patients were staged preoperatively with thin slice (5−7 mm) helical computed tomography chest, abdomen and pelvis. Synchronous metastases were defined as those found during, or on imaging carried out within 1 month of, colorectal resection. Criteria for laparoscopic unresectability were: (i) histologically proven extrahepatic disease; (ii) bilateral inflow or outflow involvement; (iii) the presence of cirrhosis in patients requiring an extended resection (lobectomy or greater); or (iv) hepatic metastases involving more than six hepatic segments.

Results:  In 24 patients with synchronous metastases (median age 65 years, range 32−81 years) all were resectable on laparoscopic criteria, of whom 21 were resected. Extrahepatic disease was found at laparotomy in three patients. In 35 patients with metachronous metastases (median age 64 years, range 32−81 years) laparoscopy could not be performed in five patients because of adhesions, and three patients were deemed unresectable on laparoscopic criteria. Of the remaining 27 patients, 25 underwent resection while two proved unresectable. Overall eight of 54 evaluable patients had unresectable disease and laparoscopy correctly identified three patients.

Conclusions:  Following computed tomography scan, 15% of patients with metastatic colorectal carcinoma will be found to have unresectable disease. Laparoscopy will identify approximately half. Laparoscopy is of no greater value in staging synchronous versus metachronous metastases.