bluuebunny/crossref_metadata_2025 huggingface dataset:
Family Firms as Incubators for Spirituality in the Workplace: Factors That Nurture Spiritual Businesses
Authors: Neal Judi , Vallejo Manuel C.
Published: March 2010

This paper proposes that family firms typically possess specific cultural characteristics that stimulate the development of spirituality in the workplace more than those of non-family firms. We briefly list the trends that have led to a growing appreciation of spirituality in organizations,
and provide a description of the characteristics of spiritual businesses. We offer an analysis of the connections between the cultural characteristics of family firms, and the characteristics of spiritual businesses. In the last section we provide the analysis of two different case studies
of family firms, the first one as an example of incubator for spirituality in the workplace, and the second one as a clear example of a spiritual business. We propose suggestions for further research.
Exploring Entrepreneurship through the Lens of Spirituality
Authors: Kauanui Sandra King , Thomas Kevin D. , Sherman Cynthia L. , Waters Gail Ross , Gilea Mihaela
Published: March 2010

A two-stage research project utilizing grounded theory was conducted with 134 entrepreneurs to better understand their motivational factors. Utilizing spiritual concepts, researchers were able to discover a deeper understanding of the entrepreneurs. Initially, three distinct modalities of entrepreneurs were identified, which were expanded into five: ‘Make me Whole,’ ‘Soul Seekers,’ ‘Conflicting Goals,’ ‘Mostly Business’, and ‘Strictly Business’. Respondent comments that represent each of these modalities are presented and indicate various levels of dependency or independency on spiritually-oriented attributes.
Making Sense of Workplace Spirituality: Towards a New Methodology
Authors: McKee Margaret C. , Mills Jean Helms , Driscoll Cathy
Published: March 2010

The study of workplace spirituality is a relatively new area in the field of organizational theory. Although interest in the topic has grown significantly over the last 10 years, many of the traditional research methods are not well suited to study workplace spirituality at the organizational level. We propose that sensemaking offers a useful heuristic for understanding the process of institutionalizing workplace spirituality, as well as a way to study how and why workplace spirituality initiatives are wholly accepted by some individuals and resisted by others.
Self, Soul and Management Learning: Constructing the Genre of the Spiritualized Manager
Authors: Cullen John
Published: March 2010

What form of management is suggested by the increased interest in organizational spirituality and what genre of manager does spiritual learning attempt to construct? The growth of interest in organizational spirituality and its implications for management learning and development are
discussed. Various approaches for understanding the self are explored, and a model for organizing these approaches, and the ‘Selves’ they imply, are presented. Burgoyne's (2002) outline of the different styles of learning approaches and the types of ‘Self’ they seek
to construct are discussed in an attempt to clarify how spiritual management learning approaches are understood with the aim of clarifying a new, spiritualized form (or genre) of managerial self, which the discourse of organizational spirituality appears to seek.
An Ideal Type of Spiritually Informed Organizations: a Sociological Model
Authors: Bowman Timothy James
Published: March 2010

With the insurgence of the spirituality of work phenomenon there is need for an apposite model against which practitioners, researchers and social scientists can empirically study contemporary workplace structures, or even to understand prior types of spiritual organizations. From case
studies of a Benedictine monastery and of the Ford Motor Company, the “spiritual-family”, a new ideal type of spiritually informed social structure based on charismatic authority is proposed and compared against Weber's ideal type of bureaucracy. In their purest forms, the spiritual-family
elects and Weber's bureaucracy appoints their superiors respectively. A central structural difference between the two is the means for this selection.
A Privileged Conversation
Authors: Western Simon , Sedgmore Lynne
Published: March 2010

Simon Western, PhD works independently and his Company focuses on liberating individuals and teams to discover their ‘freedom to act’. He designs organizational architectures that inspire creativity and encourage leadership to flourish.Lynne Sedgmore CBE is the Chief
Executive of the Centre for Excellence in Leadership for the Learning and Skills Sector in the UK.This paper reflects on a coaching relationship that became a ‘privileged conversation’ between a leadership coach and a CEO over a two-year period. It was privileged in the sense
of having a profound impact on both parties and on the organization. During the initial contracting both parties were aware of the others spirituality however the focus of the contract was clearly on improving the performance of the leader and the organization. However as the coaching relationship
developed, spirituality became more explicit and a powerful aspect of the work. This paper will describe Think Coaching, a new framework that focuses on creating a ‘thinking space’ and working with hope, imagination and connectivity across networks. As the spiritual dialogue
evolved both parties were freed to work in an integrated manner to unusual depths whilst remaining task orientated. The paper concludes by showing how this coaching framework can encourage a coaching process that works across the boundary of spirituality and a secular workplace. The framework
also offers the potential to be developed and used by spiritual directors and within different settings of pastoral care.
Quantization of quasi-Lie bialgebras
Authors: Enriquez Benjamin , Halbout Gilles
Published: March 2010

We construct quantization functors of quasi-Lie bialgebras. We establish a bijection between this set of quantization functors, modulo equivalence and twist equivalence, and the set of quantization functors of Lie bialgebras, modulo equivalence. This is based on the acyclicity of the kernels of natural morphisms between the universal versions of Lie algebra cohomology complexes for quasi-Lie and Lie bialgebras. The proof of this acyclicity consists of several steps, ending up in the acyclicity of a complex related to free Lie algebras, namely, the universal version of the Lie algebra cohomology complex of a Lie algebra in its enveloping algebra, viewed as the left regular module. Using the same arguments, we also prove the compatibility of quantization functors of quasi-Lie bialgebras with twists, which allows us to recover our earlier results on compatibility of quantization functors with twists in the case of Lie bialgebras.
On abelian birational sections
Authors: Esnault Hélène , Wittenberg Olivier
Published: March 2010

For a smooth and geometrically irreducible variety 

X
X

over a field 

k
k

, the quotient of the absolute Galois group

G

k
(
X
)

G_{k(X)}

by the commutator subgroup of

G

k
¯

(
X
)

G_{\bar k(X)}

projects onto 

G
k

G_k

. We investigate the sections of this projection. We show that such sections correspond to “infinite divisions” of the elementary obstruction of Colliot-Thélène and Sansuc. If 

k
k

is a number field and the Tate–Shafarevich group of the Picard variety of 

X
X

is finite, then such sections exist if and only if the elementary obstruction vanishes. For curves this condition also amounts to the existence of divisors of degree 

1
1

. Finally we show that the vanishing of the elementary obstruction is not preserved by extensions of scalars.
Log canonical singularities are Du Bois
Authors: Kollár János , Kovács Sándor
Published: March 2010

A recurring difficulty in the Minimal Model Program is that while log terminal singularities are quite well behaved (for instance, they are rational), log canonical singularities are much more complicated; they need not even be Cohen-Macaulay. The aim of this paper is to prove that log canonical singularities are Du Bois. The concept of Du Bois singularities, introduced by Steenbrink, is a weakening of rationality. We also prove flatness of the cohomology sheaves of the relative dualizing complex of a projective family with Du Bois fibers. This implies that each connected component of the moduli space of stable log varieties parametrizes either only Cohen-Macaulay or only non-Cohen-Macaulay objects.
Uniqueness of enhancement for triangulated categories
Authors: Lunts Valery , Orlov Dmitri
Published: March 2010

The paper contains general results on the uniqueness of a DG enhancement for triangulated categories. As a consequence we obtain such uniqueness for the unbounded derived categories of quasi-coherent sheaves, for the triangulated categories of perfect complexes, and for the bounded derived categories of coherent sheaves on quasi-projective schemes. If a scheme is projective, then we also prove a strong uniqueness for the triangulated category of perfect complexes and for the bounded derived categories of coherent sheaves. These results directly imply that fully faithful functors from the bounded derived categories of coherent sheaves and the triangulated categories of perfect complexes on projective schemes can be represented by objects on the product.
Nup98-Homeodomain Fusions Interact with Endogenous Nup98 during Interphase and Localize to Kinetochores and Chromosome Arms during Mitosis
Authors: Xu Songli , Powers Maureen A.
Published: March 2010

Chromosomal translocations involving the Nup98 gene are implicated in leukemias, especially acute myelogenous leukemia. These translocations generate chimeric fusion proteins, all of which have in common the N-terminal half of Nup98, which contains the nucleoporin FG/GLFG repeat motifs. The homeodomain group of Nup98 fusion proteins retain the C-terminus of a homeodomain transcription factor, including the homeobox responsible for DNA binding. Current models for Nup98 leukemogenesis invoke aberrant transcription resulting from recruitment of coregulators by the Nup98 repeat domain. Here we have investigated the behavior of Nup98-homeodomain fusion proteins throughout the cell cycle. At all stages, the fusion proteins exhibit a novel localization distinct from the component proteins or fragments. During interphase, there are dynamic interactions between the Nup98 fusions and endogenous Nup98 that lead to mislocalization of the intranuclear fraction of Nup98, but do not alter the level of Nup98 at the nuclear pore complex. During mitosis, no interaction between the fusion proteins and endogenous Nup98 is observed. However, the fusions are entirely concentrated at kinetochores and on chromosome arms, sites where the APC/C, a target of Nup98 regulation, is also found. Our observations suggest new possibilities for misregulation by which Nup98 translocations may contribute to cellular transformation and leukemogenesis.
Endogenous RhoG Is Rapidly Activated after Epidermal Growth Factor Stimulation through Multiple Guanine-Nucleotide Exchange Factors
Authors: Samson Thomas , Welch Christopher , Monaghan-Benson Elizabeth , Hahn Klaus M. , Burridge Keith
Published: March 2010

RhoG is a member of the Rac-like subgroup of Rho GTPases and has been linked to a variety of different cellular functions. Nevertheless, many aspects of RhoG upstream and downstream signaling remain unclear; in particular, few extracellular stimuli that modulate RhoG activity have been identified. Here, we describe that stimulation of epithelial cells with epidermal growth factor leads to strong and rapid activation of RhoG. Importantly, this rapid activation was not observed with other growth factors tested. The kinetics of RhoG activation after epidermal growth factor (EGF) stimulation parallel the previously described Rac1 activation. However, we show that both GTPases are activated independently of one another. Kinase inhibition studies indicate that the rapid activation of RhoG and Rac1 after EGF treatment requires the activity of the EGF receptor kinase, but neither phosphatidylinositol 3-kinase nor Src kinases. By using nucleotide-free RhoG pull-down assays and small interfering RNA-mediated knockdown studies, we further show that guanine-nucleotide exchange factors (GEFs) of the Vav family mediate EGF-induced rapid activation of RhoG. In addition, we found that in certain cell types the recently described RhoG GEF PLEKHG6 can also contribute to the rapid activation of RhoG after EGF stimulation. Finally, we present results that show that RhoG has functions in EGF-stimulated cell migration and in regulating EGF receptor internalization.
A Century‐Long Perspective on Agricultural Development
Authors: Barrett Christopher B. , Carter Michael R. , Timmer C. Peter
Published: March 2010

This article strategically surveys the past century's literature on agricultural development. We organize the discussion around three “grand themes” that reveal the richness of agricultural development as an intellectual endeavor. First, we explore the role of agriculture in the broader development process from a macroeconomic and political economy perspective. We then examine the role of technological and institutional change in successful agricultural development. Finally, the focus turns to a microeconomic perspective on agricultural household decision making and the problems of imperfect and missing markets, asymmetric information, and transactions costs that lead to widespread apparent inefficiency and disequilibrium.
Natural Resource Economics and Conservation: Contributions of Agricultural Economics and Agricultural Economists
Authors: Lichtenberg Erik , Shortle James , Wilen James , Zilberman David
Published: March 2010

Research by agricultural economists on natural resources has been distinguished by an interdisciplinary emphasis and a dynamic perspective. It has recognized technological and institutional constraints, has been oriented toward solving concrete resource management and policy problems, and has emphasized empirical and quantitative analysis. Agricultural economists have introduced methods for evaluating natural resource conservation efforts, for predicting adoption of resource conservation technologies, and for designing efficient and sustainable resource management policies. They have identified ways of improving land management and preventing land degradation, proposed reforms of institutions governing water allocation and water quality, and introduced policies for balancing environmental and efficiency considerations in the management of pests, biodiversity, and livestock diseases. Their research has had substantial impacts on the formulation of resource conservation policies.
A Century of Research on Rural Development and Regional Issues
Authors: Irwin Elena G. , Isserman Andrew M. , Kilkenny Maureen , Partridge Mark D.
Published: March 2010

Rural North America has undergone a major economic transformation over the past century due to labor‐saving technological progress, reductions in transport costs, and rising household incomes. The results are greater rural economic diversity, selected rural population decline, increased rural–urban interdependence, emergent exurban areas, and amenity‐led rural growth. We summarize key research insights and provide a selected review of the economics literature over the past 100 years with a focus on this economic transformation of rural places, its implications for rural communities, and key modeling innovations and applications. The many important contributions by agricultural economists are highlighted.
The AAEA: Ever Growing and Changing Research Challenges
Authors: McCalla Alex , Castle Emery , Eidman Vernon
Published: March 2010

The changing economic conditions over the past century, along with changes in technology and developments in economic theory and quantitative methods, helped shape the profession we currently refer to as agricultural and applied economics. The broadening of the profession from the original focus on the farm and agricultural industry to encompass international affairs, governmental policies, resources, and environmental and rural affairs is discussed within this context. Emergence of the subdisciplines and some of the major individual contributions are noted. The final section argues that members of the profession are well positioned to continue contributing research that will help society achieve its goals, and notes six challenges that provide such opportunities.
A Century of Research on Agricultural Markets
Authors: Myers Robert J. , Sexton Richard J. , Tomek William G.
Published: March 2010

This article provides a perspective on major innovations in research on agricultural markets over the past century. We review research on market structure and performance, vertical coordination arrangements, and institutions for producer collective action. Contributions to empirical modeling of agricultural price determination and marketing margins are also evaluated, as are innovations in research on spatial market relationships and the role of storage. Finally, we discuss contributions to understanding market information systems and the functioning of market‐based mechanisms for agricultural risk management, including futures, options, and insurance. Although progress over the century has been remarkable, we conclude by highlighting possible directions for future research.
Evolution of the Economics of Agricultural Policy
Authors: Sumner Daniel A. , Alston Julian M. , Glauber Joseph W.
Published: March 2010

Agricultural economists helped develop farm programs to respond to the dire economic situation of the 1920s and 1930s. Some early authors appreciated that such policies created problems in markets for commodities and inputs. Over time, our understanding of agricultural issues and policies has deepened. Through the application of improved models and tools of analysis to more extensive data, we have developed better answers to old questions, and have responded to changing policy instruments, market contexts, and policy concerns. This article traces the evolution of our deepening economic understanding of the causes and consequences of agricultural policy.
Mutual information is critically dependent on prior assumptions: would the correct estimate of mutual information please identify itself?
Authors: Fernandes Andrew D. , Gloor Gregory B.
Published: March 2010

Motivation: Mutual information (MI) is a quantity that measures the dependence between two arbitrary random variables and has been repeatedly used to solve a wide variety of bioinformatic problems. Recently, when attempting to quantify the effects of sampling variance on computed values of MI in proteins, we encountered striking differences among various novel estimates of MI. These differences revealed that estimating the ‘true’ value of MI is not a straightforward procedure, and minor variations of assumptions yielded remarkably different estimates.

Results: We describe four formally equivalent estimates of MI, three of which explicitly account for sampling variance, that yield non-equal values of MI given exact frequencies. These MI estimates are essentially non-predictive of each other, converging only in the limit of implausibly large datasets. Lastly, we show that all four estimates are biologically reasonable estimates of MI, despite their disparity, since each is actually the Kullback–Leibler divergence between random variables conditioned on equally plausible hypotheses.

Conclusions: For sparse contingency tables of the type universally observed in protein coevolution studies, our results show that estimates of MI, and hence inferences about physical phenomena such as coevolution, are critically dependent on at least three prior assumptions. These assumptions are: (i) how observation counts relate to expected frequencies; (ii) the relationship between joint and marginal frequencies; and (iii) how non-observed categories are interpreted. In any biologically relevant data, these assumptions will affect the MI estimate as much or more-so than observed data, and are independent of uncertainty in frequency parameters.

Contact:  andrew@fernandes.org

Supplementary information:  Supplementary data are available at Bioinformatics online.
A machine learning approach to predicting protein–ligand binding affinity with applications to molecular docking
Authors: Ballester Pedro J. , Mitchell John B. O.
Published: March 2010

Motivation: Accurately predicting the binding affinities of large sets of diverse protein–ligand complexes is an extremely challenging task. The scoring functions that attempt such computational prediction are essential for analysing the outputs of molecular docking, which in turn is an important technique for drug discovery, chemical biology and structural biology. Each scoring function assumes a predetermined theory-inspired functional form for the relationship between the variables that characterize the complex, which also include parameters fitted to experimental or simulation data and its predicted binding affinity. The inherent problem of this rigid approach is that it leads to poor predictivity for those complexes that do not conform to the modelling assumptions. Moreover, resampling strategies, such as cross-validation or bootstrapping, are still not systematically used to guard against the overfitting of calibration data in parameter estimation for scoring functions.

Results: We propose a novel scoring function (RF-Score) that circumvents the need for problematic modelling assumptions via non-parametric machine learning. In particular, Random Forest was used to implicitly capture binding effects that are hard to model explicitly. RF-Score is compared with the state of the art on the demanding PDBbind benchmark. Results show that RF-Score is a very competitive scoring function. Importantly, RF-Score's performance was shown to improve dramatically with training set size and hence the future availability of more high-quality structural and interaction data is expected to lead to improved versions of RF-Score.

Contact:  pedro.ballester@ebi.ac.uk; jbom@st-andrews.ac.uk

Supplementary information:  Supplementary data are available at Bioinformatics online.
Early emergence in a butterfly causally linked to anthropogenic warming
Authors: Kearney Michael R. , Briscoe Natalie J. , Karoly David J. , Porter Warren P. , Norgate Melanie , Sunnucks Paul
Published: March 2010

There is strong correlative evidence that human-induced climate warming is contributing to changes in the timing of natural events. Firm attribution, however, requires cause-and-effect links between observed climate change and altered phenology, together with statistical confidence that observed regional climate change is anthropogenic. We provide evidence for phenological shifts in the butterfly
Heteronympha merope
in response to regional warming in the southeast Australian city of Melbourne. The mean emergence date for
H. merope
has shifted −1.5 days per decade over a 65-year period with a concurrent increase in local air temperatures of approximately 0.16°C per decade. We used a physiologically based model of climatic influences on development, together with statistical analyses of climate data and global climate model projections, to attribute the response of
H. merope
to anthropogenic warming. Such mechanistic analyses of phenological responses to climate improve our ability to forecast future climate change impacts on biodiversity.
The feeding ecology of little auks raises questions about winter zooplankton stocks in North Atlantic surface waters
Authors: Fort Jérôme , Cherel Yves , Harding Ann M. A. , Egevang Carsten , Steen Harald , Kuntz Grégoire , Porter Warren P. , Grémillet David
Published: March 2010

Copepods are essential components of marine food webs worldwide. In the North Atlantic, they are thought to perform vertical migration and to remain at depths more than 500 m during winter. We challenge this concept through a study of the winter feeding ecology of little auks (
Alle alle
), a highly abundant planktivorous seabird from the North Atlantic. By combining stable isotope and behavioural analyses, we strongly suggest that swarms of copepods are still available to their predators in water surface layers (less than 50 m) during winter, even during short daylight periods. Using a new bioenergetic model, we estimate that the huge number (20–40 million birds) of little auks wintering off southwest Greenland consume 3600–7200 tonnes of copepods daily, strongly suggesting substantial zooplankton stocks in surface waters of the North Atlantic in the middle of the boreal winter.
Alarm calls elicit predator-specific physiological responses
Authors: Mateo Jill M.
Published: March 2010

Glucocorticoids regulate glucose concentrations and responses to unpredictable events, while also modulating cognition. Juvenile Belding's ground squirrels (Urocitellus beldingi) learn to respond to whistle and trill alarm calls, warning of aerial and terrestrial predators, respectively, shortly after emerging from natal burrows at one month of age. Alarm calls can cause physiological reactions and arousal, and this arousal, coupled with watching adult responses, might help juveniles learn associations between calls and behavioural responses. I studied whether young show differential cortisol responses to alarm and non-alarm calls, using playbacks ofU. beldingiwhistles, trills, squeals (a conspecific control vocalization) and silent controls. Trills elicited very high cortisol responses, and, using an individual's response to the silent control as baseline, only their response to a trill was significantly higher than baseline. This cortisol increase would provide glucose for extended vigilance and escape efforts, which is appropriate for evading terrestrial predators which hunt for long periods. Although whistles do not elicit a cortisol response, previous research has shown that they do result in bradycardia, which enhances attention and information processing. This is a novel demonstration of two physiological responses to two alarm calls, each appropriate to the threats represented by the calls.
Cerebrospinal fluid dynamics in the human cranial subarachnoid space: an overlooked mediator of cerebral disease. I. Computational model
Authors: Gupta Sumeet , Soellinger Michaela , Grzybowski Deborah M. , Boesiger Peter , Biddiscombe John , Poulikakos Dimos , Kurtcuoglu Vartan
Published: March 2010

Abnormal cerebrospinal fluid (CSF) flow is suspected to be a contributor to the pathogenesis of neurodegenerative diseases such as Alzheimer's through the accumulation of toxic metabolites, and to the malfunction of intracranial pressure regulation, possibly through disruption of neuroendocrine communication. For the understanding of transport processes involved in either, knowledge of
in vivo
CSF dynamics is important. We present a three-dimensional, transient, subject-specific computational analysis of CSF flow in the human cranial subarachnoid space (SAS) based on
in vivo
magnetic resonance imaging. We observed large variations in the spatial distribution of flow velocities with a temporal peak of 5 cm s
−1
in the anterior SAS and less than 4 mm s
−1
in the superior part. This could reflect dissimilar flushing requirements of brain areas that may show differences in susceptibility to pathological CSF flow. Our methods can be used to compare the transport of metabolites and neuroendocrine substances in healthy and diseased brains.
The fourth element: characteristics, modelling and electromagnetic theory of the memristor
Authors: Kavehei O. , Iqbal A. , Kim Y. S. , Eshraghian K. , Al-Sarawi S. F. , Abbott D.
Published: March 2010

In 2008, researchers at the Hewlett–Packard (HP) laboratories published a paper in
Nature
reporting the development of a new basic circuit element that completes the missing link between charge and flux linkage, which was postulated by Chua in 1971 (Chua 1971
IEEE Trans. Circuit Theory
18
, 507–519 (
doi:10.1109/TCT.1971.1083337
)). The HP memristor is based on a nanometre scale TiO
2
thin film, containing a— doped region and an undoped region. Further to proposed applications of memristors in artificial biological systems and non-volatile RAM, they also enable reconfigurable nanoelectronics. Moreover, memristors provide new paradigms in application-specific integrated circuits and field programmable gate arrays. A significant reduction in area with an unprecedented memory capacity and device density are the potential advantages of memristors for integrated circuits. This work reviews the memristor and provides mathematical and SPICE models for memristors. Insight into the memristor device is given via recalling the quasi-static expansion of Maxwell’s equations. We also review Chua’s arguments based on electromagnetic theory.
Strain gradient solution for Eshelby’s ellipsoidal inclusion problem
Authors: Gao X.-L. , Ma H. M.
Published: March 2010

Eshelby’s problem of an ellipsoidal inclusion embedded in an infinite homogeneous isotropic elastic material and prescribed with a uniform eigenstrain and a uniform eigenstrain gradient is analytically solved. The solution is based on a simplified strain gradient elasticity theory (SSGET) that contains one material length scale parameter in addition to two classical elastic constants. The fourth-order Eshelby tensor is obtained in analytical expressions for both the regions inside and outside the inclusion in terms of two line integrals and two surface integrals. This non-classical Eshelby tensor consists of a classical part and a gradient part. The former involves Poisson’s ratio only, while the latter includes the length scale parameter additionally, which enables the newly obtained Eshelby tensor to capture the inclusion size effect, unlike its counterpart based on classical elasticity. The accompanying fifth-order Eshelby-like tensor relates the prescribed eigenstrain gradient to the disturbed strain and has only a gradient part. When the strain gradient effect is not considered, the new Eshelby tensor reduces to the classical Eshelby tensor, and the Eshelby-like tensor vanishes. In addition, the current Eshelby tensor for the ellipsoidal inclusion problem includes those for the spherical and cylindrical inclusion problems based on the SSGET as two limiting cases. The non-classical Eshelby tensor depends on the position and is non-uniform even inside the inclusion, which differ from its classical counterpart. For homogenization applications, the volume average of the new Eshelby tensor over the ellipsoidal inclusion is analytically obtained. The numerical results quantitatively show that the components of the newly derived Eshelby tensor vary with both the position and the inclusion size, unlike their classical counterparts. When the inclusion size is small, it is found that the contribution of the gradient part is significantly large. It is also seen that the components of the averaged Eshelby tensor change with the inclusion size: the smaller the inclusion, the smaller the components. Moreover, these components are observed to approach the values of their classical counterparts from below when the inclusion size becomes sufficiently large.
Regularity and singularity in solutions of the three-dimensional Navier–Stokes equations
Authors: Gibbon J. D.
Published: March 2010

Higher moments of the vorticity field
Ω

m

(
t
) in the form of
L

2
m

-norms (

) are used to explore the regularity problem for solutions of the three-dimensional incompressible Navier–Stokes equations on the domain

. It is found that the set of quantities

provide a natural scaling in the problem resulting in a bounded set of time averages 〈
D

m

〉

T

on a finite interval of time [0, 
T
]. The behaviour of
D

m
+1

/
D

m

is studied on what are called ‘good’ and ‘bad’ intervals of [0, 
T
], which are interspersed with junction points (neutral)
τ

i

. For large but finite values of
m
with large initial data (
Ω

m

(0)≤
ϖ
0
O
(
Gr
4
)), it is found that there is an upper bound

which is punctured by infinitesimal gaps or windows in the vertical walls between the good/bad intervals through which solutions may escape. While this result is consistent with that of Leray (Leray 1934
Acta Math.
63
, 193–248 (
doi:10.1007/BF02547354
)) and Scheffer (Scheffer 1976
Pacific J. Math.
66
, 535–552),— this estimate for
Ω

m

corresponds to a length scale well below the validity of the Navier–Stokes equations.
A probabilistic twin nucleation model for HCP polycrystalline metals
Authors: Beyerlein I. J. , Tomé C. N.
Published: March 2010

This article presents a basic probabilistic theory for the nucleation of deformation twins in hexagonal close packed (HCP) metals. Twin nucleation is assumed to rely on the dissociation of grain boundary defects (GBDs) under stress into the required number of twinning partials to create a twin nucleus. The number of successful conversion events is considered to follow a stochastic Poisson process where the rate is assumed to increase with local stress. From this concept, the probability distribution for the critical stress to form a twin nucleus is derived wherein the parameters of the distribution are related to properties of the GBDs. The theory is implemented into a multi-scale constitutive model for HCP metals in order to test its predictive capability against measurements made previously on pure zirconium deformed at 76 and 300 K.
Linking predator risk and uncertainty to adaptive forgetting: a theoretical framework and empirical test using tadpoles
Authors: Ferrari Maud C. O. , Brown Grant E. , Bortolotti Gary R. , Chivers Douglas P.
Published: March 2010

Hundreds of studies have examined how prey animals assess their risk of predation. These studies work from the basic tennet that prey need to continually balance the conflicting demands of predator avoidance with activities such as foraging and reproduction. The information that animals gain regarding local predation risk is most often learned. Yet, the concept of ‘memory’ in the context of predation remains virtually unexplored. Here, our goal was (i) to determine if the memory window associated with predator recognition is fixed or flexible and, if it is flexible, (ii) to identify which factors affect the length of this window and in which ways. We performed an experiment on larval wood frogs,Rana sylvatica, to test whether the risk posed by, and the uncertainty associated with, the predator would affect the length of the tadpoles' memory window. We found that as the risk associated with the predator increases, tadpoles retained predator-related information for longer. Moreover, if the uncertainty about predator-related information increases, then prey use this information for a shorter period. We also present a theoretical framework aiming at highlighting both intrinsic and extrinsic factors that could affect the memory window of information use by prey individuals.
Local community size mediates ecological drift and competition in metacommunities
Authors: Orrock John L. , Watling James I.
Published: March 2010

The outcome of competitive interactions is likely to be influenced by both competitive dominance (i.e. niche-based dynamics) and ecological drift (i.e. neutral dynamics governed by demographic stochasticity). However, spatial models of competition rarely consider the joint operation of these two processes. We develop a model based on the original competition-colonization trade-off model that incorporates niche and neutral processes and several realistic facets of ecological dynamics: it allows local competition (i.e. competition within a patch) to occur within communities of a finite size, it allows competitors to vary in the degree of competitive asymmetry, and it includes the role of local migration (i.e. propagule pressure). The model highlights the role of community size, i.e. the number of competitors in the local community, in mediating the relative importance of stochastic and deterministic forces. In metacommunities where local communities are small, ecological drift is substantial enough that strong competitors become effectively neutral, creating abrupt changes in the outcome of competition not predicted by the standard competition-colonization trade-off. Importantly, the model illustrates that, even when other aspects of species interactions (e.g. migration ability, competitive ability) are unchanged, local community size can alter the dynamics of metacommunity persistence. Our work demonstrates that activities which reduce the size of local communities, such as habitat destruction and degradation, effectively compound the extinction debt.
Wernicke's area homologue in chimpanzees (Pan troglodytes) and its relation to the appearance of modern human language
Authors: Spocter Muhammad A. , Hopkins William D. , Garrison Amy R. , Bauernfeind Amy L. , Stimpson Cheryl D. , Hof Patrick R. , Sherwood Chet C.
Published: March 2010

Human language is distinctive compared with the communication systems of other species. Yet, several questions concerning its emergence and evolution remain unresolved. As a means of evaluating the neuroanatomical changes relevant to language that accompanied divergence from the last common ancestor of chimpanzees, bonobos and humans, we defined the cytoarchitectonic boundaries of area Tpt, a component of Wernicke's area, in 12 common chimpanzee brains and used design-based stereologic methods to estimate regional volumes, total neuron number and neuron density. In addition, we created a probabilistic map of the location of area Tpt in a template chimpanzee brain coordinate space. Our results show that chimpanzees display significant population-level leftward asymmetry of area Tpt in terms of neuron number, with volume asymmetry approaching significance. Furthermore, asymmetry in the number of neurons in area Tpt was positively correlated with asymmetry of neuron numbers in Brodmann's area 45, a component of Broca's frontal language region. Our findings support the conclusion that leftward asymmetry of Wernicke's area originated prior to the appearance of modern human language and before our divergence from the last common ancestor. Moreover, this study provides the first evidence of covariance between asymmetry of anterior and posterior cortical regions that in humans are important to language and other higher order cognitive functions.
Bone density and the lightweight skeletons of birds
Authors: Dumont Elizabeth R.
Published: March 2010

The skeletons of birds are universally described as lightweight as a result of selection for minimizing the energy required for flight. From a functional perspective, the weight (mass) of an animal relative to its lift-generating surfaces is a key determinant of the metabolic cost of flight. The evolution of birds has been characterized by many weight-saving adaptations that are reflected in bone shape, many of which strengthen and stiffen the skeleton. Although largely unstudied in birds, the material properties of bone tissue can also contribute to bone strength and stiffness. In this study, I calculated the density of the cranium, humerus and femur in passerine birds, rodents and bats by measuring bone mass and volume using helium displacement. I found that, on average, these bones are densest in birds, followed closely by bats. As bone density increases, so do bone stiffness and strength. Both of these optimization criteria are used in the design of strong and stiff, but lightweight, manmade airframes. By analogy, increased bone density in birds and bats may reflect adaptations for maximizing bone strength and stiffness while minimizing bone mass and volume. These data suggest that both bone shape and the material properties of bone tissue have played important roles in the evolution of flight. They also reconcile the conundrum of how bird skeletons can appear to be thin and delicate, yet contribute just as much to total body mass as do the skeletons of terrestrial mammals.
Ecological forecasting under climate change: the case of Baltic cod
Authors: Lindegren Martin , Möllmann Christian , Nielsen Anders , Brander Keith , MacKenzie Brian R. , Stenseth Nils Chr.
Published: March 2010

Good decision making for fisheries and marine ecosystems requires a capacity to anticipate the consequences of management under different scenarios of climate change. The necessary ecological forecasting calls for ecosystem-based models capable of integrating multiple drivers across trophic levels and properly including uncertainty. The methodology presented here assesses the combined impacts of climate and fishing on marine food-web dynamics and provides estimates of the confidence envelope of the forecasts. It is applied to cod (
Gadus morhua
) in the Baltic Sea, which is vulnerable to climate-related decline in salinity owing to both direct and indirect effects (i.e. through species interactions) on early-life survival. A stochastic food web-model driven by regional climate scenarios is used to produce quantitative forecasts of cod dynamics in the twenty-first century. The forecasts show how exploitation would have to be adjusted in order to achieve sustainable management under different climate scenarios.
The Role of Ethylene and Cold Temperature in the Regulation of the Apple POLYGALACTURONASE1 Gene and Fruit Softening
Authors: Tacken Emma , Ireland Hilary , Gunaseelan Kularajathevan , Karunairetnam Sakuntala , Wang Daisy , Schultz Keith , Bowen Judith , Atkinson Ross G. , Johnston Jason W. , Putterill Jo , Hellens Roger P. , Schaffer Robert J.
Published: March 2010

Fruit softening in apple (Malus × domestica) is associated with an increase in the ripening hormone ethylene. Here, we show that in cv Royal Gala apples that have the ethylene biosynthetic gene ACC OXIDASE1 suppressed, a cold treatment preconditions the apples to soften independently of added ethylene. When a cold treatment is followed by an ethylene treatment, a more rapid softening occurs than in apples that have not had a cold treatment. Apple fruit softening has been associated with the increase in the expression of cell wall hydrolase genes. One such gene, POLYGALACTURONASE1 (PG1), increases in expression both with ethylene and following a cold treatment. Transcriptional regulation of PG1 through the ethylene pathway is likely to be through an ETHYLENE-INSENSITIVE3-like transcription factor, which increases in expression during apple fruit development and transactivates the PG1 promoter in transient assays in the presence of ethylene. A cold-related gene that resembles a COLD BINDING FACTOR (CBF) class of gene also transactivates the PG1 promoter. The transactivation by the CBF-like gene is greatly enhanced by the addition of exogenous ethylene. These observations give a possible molecular mechanism for the cold- and ethylene-regulated control of fruit softening and suggest that either these two pathways act independently and synergistically with each other or cold enhances the ethylene response such that background levels of ethylene in the ethylene-suppressed apples is sufficient to induce fruit softening in apples.
Sugar Levels Regulate Tryptophan-Dependent Auxin Biosynthesis in Developing Maize Kernels
Authors: LeClere Sherry , Schmelz Eric A. , Chourey Prem S.
Published: March 2010

The maize (Zea mays) Miniature1 (Mn1) locus encodes the cell wall invertase INCW2, which is localized predominantly in the basal endosperm transfer layer of developing kernels and catalyzes the conversion of sucrose into glucose and fructose. Mutations in Mn1 result in pleiotropic changes, including a reduction in kernel mass and a recently reported decrease in indole-3-acetic acid (IAA) levels throughout kernel development. Here, we show that mn1-1 basal kernel regions (pedicels and basal endosperm transfer layer) accumulate higher levels of sucrose and lower levels of glucose and fructose between 8 and 28 d after pollination when compared with the wild type, whereas upper regions of mn1 accumulate similar or increased concentrations of sugars. To determine the cause of the reduction in IAA accumulation, we investigated transcript levels of several potential IAA biosynthetic enzymes. We demonstrate that reduced IAA levels most closely correspond to reduced transcript levels of ZmYUCCA (ZmYUC), a newly identified homolog of the Arabidopsis (Arabidopsis thaliana) gene YUCCA. We further demonstrate that ZmYUC catalyzes the N-hydroxylation of tryptamine and that sugar levels regulate transcript levels of ZmYUC, both in in vitro-cultured kernels and in a promoter-reporter fusion in Arabidopsis. These results indicate that developing seeds may modulate growth by altering auxin biosynthesis in response to sugar concentrations.
Aberrant methylation of breast and ovarian cancer susceptibility gene 1 in chemosensitive human ovarian cancer cells does not involve the phosphatidylinositol 3′‐kinase–Akt pathway
Authors: Wang Yan‐Qiu , Zhang Jia‐Rong , Li Shuang‐Di , He Yin‐Yan , Yang Yi‐Xia , Liu Xue‐Lian , Wan Xiao‐Ping
Published: March 2010

Methylation is an important silencing mechanism of breast and ovarian cancer susceptibility gene 1 (BRCA1) expression in sporadic ovarian cancer. However, the role of BRCA1 methylation in chemotherapy in sporadic ovarian cancer and the related pathways have not been understood completely. This study has determined the roles of BRCA1 hypermethylation in chemotherapy of sporadic ovarian cancer and its related signaling pathways. We used bisulfite sequencing, real‐time polymerase chain reaction, and western blotting to check the methylation state and expression levels of BRCA1 of the following cell lines: platinum‐sensitive human ovarian cancer cell line COC1, platinum‐resistant cell line COC1/DDP, SKOV‐3, and 5‐Aza‐dC treated COC1. The cisplatin sensitivity of ovarian cancer cells was examined by MTS (methyl‐thiazol tetrazolium) assay. Tumorigenicity in vivo and DDP‐based chemosensitivity were compared among the above cells. Phosphatidylinositol 3′‐kinase (PI3K)–Akt pathway activation in ovarian cancer cells was studied by western blotting. The frequency of BRCA1 methylation in the COC1 cell line was higher than in COC1/DDP and SKOV‐3 cell lines, whereas the mRNA and protein expression of BRCA1 were lower than in the COC1/DDP and SKOV‐3 cell lines. DNA demethylation decreased the chemosensitivity of COC1 cells and partially increased the expression levels of BRCA1. The activation of the PI3K‐Akt pathway was low in ovarian cancer cells. Our results indicate that hypermethylation of BRCA1 might play an important role in the chemosensitivity of ovarian cancer, and that the PI3K–Akt pathway is not involved in this response. (Cancer Sci 2010)