bluuebunny/crossref_metadata_2025 huggingface dataset:
M-CSF improves protection against bacterial and fungal infections after hematopoietic stem/progenitor cell transplantation
Authors: Kandalla Prashanth K. , Sarrazin Sandrine , Molawi Kaaweh , Berruyer Carole , Redelberger David , Favel Anne , Bordi Christophe , de Bentzmann Sophie , Sieweke Michael H.
Published: October 2016

Myeloablative treatment preceding hematopoietic stem cell (HSC) and progenitor cell (HS/PC) transplantation results in severe myeloid cytopenia and susceptibility to infections in the lag period before hematopoietic recovery. We have previously shown that macrophage colony-stimulating factor (CSF-1; M-CSF) directly instructed myeloid commitment in HSCs. In this study, we tested whether this effect had therapeutic benefit in improving protection against pathogens after HS/PC transplantation. M-CSF treatment resulted in an increased production of mature myeloid donor cells and an increased survival of recipient mice infected with lethal doses of clinically relevant opportunistic pathogens, namely the bacteria Pseudomonas aeruginosa and the fungus Aspergillus fumigatus. M-CSF treatment during engraftment or after infection efficiently protected from these pathogens as early as 3 days after transplantation and was effective as a single dose. It was more efficient than granulocyte CSF (G-CSF), a common treatment of severe neutropenia, which showed no protective effect under the tested conditions. M-CSF treatment showed no adverse effect on long-term lineage contribution or stem cell activity and, unlike G-CSF, did not impede recovery of HS/PCs, thrombocyte numbers, or glucose metabolism. These results encourage potential clinical applications of M-CSF to prevent severe infections after HS/PC transplantation.
Dendritic cell sphingosine-1-phosphate lyase regulates thymic egress
Authors: Zamora-Pineda Jesus , Kumar Ashok , Suh Jung H. , Zhang Meng , Saba Julie D.
Published: October 2016

T cell egress from the thymus is essential for adaptive immunity and involves chemotaxis along a sphingosine-1-phosphate (S1P) gradient. Pericytes at the corticomedullary junction produce the S1P egress signal, whereas thymic parenchymal S1P levels are kept low through S1P lyase (SPL)–mediated metabolism. Although SPL is robustly expressed in thymic epithelial cells (TECs), in this study, we show that deleting SPL in CD11c+ dendritic cells (DCs), rather than TECs or other stromal cells, disrupts the S1P gradient, preventing egress. Adoptive transfer of peripheral wild-type DCs rescued the egress phenotype of DC-specific SPL knockout mice. These studies identify DCs as metabolic gatekeepers of thymic egress. Combined with their role as mediators of central tolerance, DCs are thus poised to provide homeostatic regulation of thymic export.
Elp3 links tRNA modification to IRES-dependent translation of LEF1 to sustain metastasis in breast cancer
Authors: Delaunay Sylvain , Rapino Francesca , Tharun Lars , Zhou Zhaoli , Heukamp Lukas , Termathe Martin , Shostak Kateryna , Klevernic Iva , Florin Alexandra , Desmecht Hadrien , Desmet Christophe J. , Nguyen Laurent , Leidel Sebastian A. , Willis Anne E. , Büttner Reinhard , Chariot Alain , Close Pierre
Published: October 2016

Quantitative and qualitative changes in mRNA translation occur in tumor cells and support cancer progression and metastasis. Posttranscriptional modifications of transfer RNAs (tRNAs) at the wobble uridine 34 (U34) base are highly conserved and contribute to translation fidelity. Here, we show that ELP3 and CTU1/2, partner enzymes in U34 mcm5s2-tRNA modification, are up-regulated in human breast cancers and sustain metastasis. Elp3 genetic ablation strongly impaired invasion and metastasis formation in the PyMT model of invasive breast cancer. Mechanistically, ELP3 and CTU1/2 support cellular invasion through the translation of the oncoprotein DEK. As a result, DEK promotes the IRES-dependent translation of the proinvasive transcription factor LEF1. Consistently, a DEK mutant, whose codon composition is independent of U34 mcm5s2-tRNA modification, escapes the ELP3- and CTU1-dependent regulation and restores the IRES-dependent LEF1 expression. Our results demonstrate that the key role of U34 tRNA modification is to support specific translation during breast cancer progression and highlight a functional link between tRNA modification– and IRES-dependent translation during tumor cell invasion and metastasis.
Mafb lineage tracing to distinguish macrophages from other immune lineages reveals dual identity of Langerhans cells
Authors: Wu Xiaodi , Briseño Carlos G. , Durai Vivek , Albring Jörn C. , Haldar Malay , Bagadia Prachi , Kim Ki-Wook , Randolph Gwendalyn J. , Murphy Theresa L. , Murphy Kenneth M.
Published: October 2016

Current systems for conditional gene deletion within mouse macrophage lineages are limited by ectopic activity or low efficiency. In this study, we generated a Mafb-driven Cre strain to determine whether any dendritic cells (DCs) identified by Zbtb46-GFP expression originate from a Mafb-expressing population. Lineage tracing distinguished macrophages from classical DCs, neutrophils, and B cells in all organs examined. At steady state, Langerhans cells (LCs) were lineage traced but also expressed Zbtb46-GFP, a phenotype not observed in any other population. After exposure to house dust mite antigen, Zbtb46-negative CD64+ inflammatory cells infiltrating the lung were substantially lineage traced, but Zbtb46-positive CD64− cells were not. These results provide new evidence for the unique identity of LCs and challenge the notion that some inflammatory cells are a population of monocyte-derived DCs.
Unique pathological tau conformers from Alzheimer’s brains transmit tau pathology in nontransgenic mice
Authors: Guo Jing L. , Narasimhan Sneha , Changolkar Lakshmi , He Zhuohao , Stieber Anna , Zhang Bin , Gathagan Ronald J. , Iba Michiyo , McBride Jennifer D. , Trojanowski John Q. , Lee Virginia M.Y.
Published: October 2016

Filamentous tau aggregates are hallmark lesions in numerous neurodegenerative diseases, including Alzheimer’s disease (AD). Cell culture and animal studies showed that tau fibrils can undergo cell-to-cell transmission and seed aggregation of soluble tau, but this phenomenon was only robustly demonstrated in models overexpressing tau. In this study, we found that intracerebral inoculation of tau fibrils purified from AD brains (AD-tau), but not synthetic tau fibrils, resulted in the formation of abundant tau inclusions in anatomically connected brain regions in nontransgenic mice. Recombinant human tau seeded by AD-tau revealed unique conformational features that are distinct from synthetic tau fibrils, which could underlie the differential potency in seeding physiological levels of tau to aggregate. Therefore, our study establishes a mouse model of sporadic tauopathies and points to important differences between tau fibrils that are generated artificially and authentic ones that develop in AD brains.
Independent activation of ion conduction pores in the double-barreled calcium-activated chloride channel TMEM16A
Authors: Lim Novandy K. , Lam Andy K.M. , Dutzler Raimund
Published: October 2016

The TMEM16 proteins constitute a family of membrane proteins with unusual functional breadth, including lipid scramblases and Cl− channels. Members of both these branches are activated by Ca2+, acting from the intracellular side, and probably share a common architecture, which was defined in the recent structure of the lipid scramblase nhTMEM16. The structural features of subunits and the arrangement of Ca2+-binding sites in nhTMEM16 suggest that the dimeric protein harbors two locations for catalysis that are independent with respect to both activation and lipid conduction. Here, we ask whether a similar independence is observed in the Ca2+-activated Cl− channel TMEM16A. For this purpose, we generated concatenated constructs containing subunits with distinct activation and permeation properties. Our biochemical investigations demonstrate the integrity of concatemers after solubilization and purification. During investigation by patch-clamp electrophysiology, the functional behavior of constructs containing either two wild-type (WT) subunits or one WT subunit paired with a second subunit with compromised activation closely resembles TMEM16A. This resemblance extends to ion selectivity, conductance, and the concentration and voltage dependence of channel activation by Ca2+. Constructs combining subunits with different potencies for Ca2+ show a biphasic activation curve that can be described as a linear combination of the properties of its constituents. The functional independence is further supported by mutation of a putative pore-lining residue that changes the conduction properties of the mutated subunit. Our results strongly suggest that TMEM16A contains two ion conduction pores that are independently activated by Ca2+ binding to sites that are embedded within the transmembrane part of each subunit.
Independent activation of distinct pores in dimeric TMEM16A channels
Authors: Jeng Grace , Aggarwal Muskaan , Yu Wei-Ping , Chen Tsung-Yu
Published: October 2016

The TMEM16 family encompasses Ca2+-activated Cl− channels (CaCCs) and lipid scramblases. These proteins are formed by two identical subunits, as confirmed by the recently solved crystal structure of a TMEM16 lipid scramblase. However, the high-resolution structure did not provide definitive information regarding the pore architecture of the TMEM16 channels. In this study, we express TMEM16A channels constituting two covalently linked subunits with different Ca2+ affinities. The dose–response curve of the heterodimer appears to be a weighted sum of two dose–response curves—one corresponding to the high-affinity subunit and the other to the low-affinity subunit. However, fluorescence resonance energy transfer experiments suggest that the covalently linked heterodimeric proteins fold and assemble as one molecule. Together these results suggest that activation of the two TMEM16A subunits likely activate independently of each other. The Ca2+ activation curve for the heterodimer at a low Ca2+ concentration range ([Ca2+] < 5 µM) is similar to that of the wild-type channel—the Hill coefficients in both cases are significantly greater than one. This suggests that Ca2+ binding to one subunit of TMEM16A is sufficient to activate the channel and that each subunit contains more than one Ca2+-binding site. We also take advantage of the I-V curve rectification that results from mutation of a pore residue to address the pore architecture of the channel. By introducing the pore mutation and the mutation that alters Ca2+ affinity in the same or different subunits, we demonstrate that activation of different subunits appears to be associated with the opening of different pores. These results suggest that the TMEM16A CaCC may also adopt a “double-barrel” pore architecture, similar to that found in CLC channels and transporters.
Particulate matter disrupts human lung endothelial cell barrier integrity via Rho‐dependent pathways
Authors: Wang Ting , Shimizu Yuka , Wu Xiaomin , Kelly Gabriel T. , Xu Xiaoyan , Wang Lichun , Qian Zhongqing , Chen Yin , Garcia Joe G.N.
Published: October 2016

Increased exposure to ambient particulate matter (PM) is associated with elevated morbidity and mortality in patients with cardiopulmonary diseases and cancer. We and others have shown that PM induces lung microvascular barrier dysfunction which potentially enhances the systemic toxicity of PM. However, the mechanisms by which PM disrupts vascular endothelial integrity remain incompletely explored. We hypothesize that PM induces endothelial cell (EC) cytoskeleton rearrangement via Rho GTPase‐dependent pathways to facilitate vascular hyperpermeability. Fine PM induced time‐dependent activation of cytoskeletal machinery with increases in myosin light chain (MLC) phosphorylation and EC barrier disruption measured by transendothelial electrical resistance (TER), events attenuated by the Rho‐dependent kinase (ROCK) inhibitor Y‐27632 or the reactive oxygen species (ROS) scavenger, N‐acetylcysteine (NAC). Both Y‐27632 and NAC prevented PM‐induced stress fiber formation and phospho‐MLC accumulation in human lung ECs. PM promotes rapid accumulation of Rho‐GTP. This event is attenuated by NAC or knockdown of RhoA (siRNA). Consistent with ROCK activation, PM induced phosphorylation of myosin light chain phosphatase (MYPT) at Thr850, a post‐translational modification known to inhibit phosphatase activity. Furthermore, PM activates the guanine nucleotide exchange factor (GEF) for Rho, p115, with p115 translocation to the cell periphery, in a ROS‐dependent manner. Together these results demonstrate that fine PM induces EC cytoskeleton rearrangement via Rho‐dependent pathways that are dependent upon the generation of oxidative stress. As the disruption of vascular integrity further contributes to cardiopulmonary physiologic derangements, these findings provide pharmacologic targets for prevention of PM‐induced cardiopulmonary toxicity.
Axisymmetric oscillations at L–H transitions in JET: M-mode
Authors: Solano Emilia R. , Vianello N. , Delabie E. , Hillesheim J.C. , Buratti P. , Réfy D. , Balboa I. , Boboc A. , Coelho R. , Sieglin B. , Silburn S. , Drewelow P. , Devaux S. , Dodt D. , Figueiredo A. , Frassinetti L. , Marsen S. , Meneses L. , Maggi C.F. , Morris J. , Gerasimov S. , Baruzzo M. , Stamp M. , Grist D. , Nunes I. , Rimini F. , Schmuck S. , Lupelli I. , Silva C.
Published: October 2016

L to H transition studies at JET have revealed an n  =  0, m  =  1 magnetic oscillation starting immediately at the L to H transition (called M-mode for brevity). While the magnetic oscillation is present a weak ELM-less H-mode regime is obtained, with a clear increase of density and a weak electron temperature pedestal. It is an intermediate state between L and H-mode. In ICRH heated plasmas or low density NBI plasmas the magnetic mode and the pedestal can remain steady (with small oscillations) for the duration of the heating phase, of order 10 s or more. The axisymmetric magnetic oscillation has period ~0.5–2 ms, and poloidal mode number m  =  1: it looks like a pedestal localised up/down oscillation, although it is clearly a natural oscillation of the plasma, not driven by the position control system. Electron cyclotron emission, interferometry, reflectometry and fast Li beam measurements locate the mode in the pedestal region. D

α
, fast infrared camera and Langmuir probe measurements show that the mode modulates heat and particle fluxes to the target. The mode frequency appears to scale with the poloidal Alfvén velocity, and not with sound speed (i.e. it is not a geodesic acoustic mode). A heuristic model is proposed for the frequency scaling of the mode. We discuss the relationship between the M-mode and other related observations near the L–H transition.
Pseudo-Anosov maps and continuum theory
Authors: Artigue Alfonso
Published: October 2016

In the hyperspace of subcontinua of a compact surface we consider a second order Hausdorff distance. This metric space is compactified in such a way that the stable foliation of a pseudo-Anosov map is naturally identified with a hypercontinuum. We show that negative iterates of a stable arc converge to this hypercontinuum in the considered metric. Some dynamical properties of pseudo-Anosov maps, as topological mixing and the density of stable leaves, are generalized for cw-expansive homeomorphisms of pseudo-Anosov type on compact metric spaces.
On the Auslander–Reiten conjecture for Cohen–Macaulay local rings
Authors: Goto Shiro , Takahashi Ryo
Published: October 2016

This paper studies vanishing of Ext modules over Cohen–Macaulay local rings. The main result of this paper implies that the Auslander–Reiten conjecture holds for maximal Cohen–Macaulay modules of rank one over Cohen–Macaulay normal local rings. It also recovers a theorem of Avramov–Buchweitz–Şega and Hanes–Huneke, which shows that the Tachikawa conjecture holds for Cohen–Macaulay generically Gorenstein local rings.
Digital inversive vectors can achieve polynomial tractability for the weighted star discrepancy and for multivariate integration
Authors: Dick Josef , Gomez-Perez Domingo , Pillichshammer Friedrich , Winterhof Arne
Published: October 2016

We study high-dimensional numerical integration in the worst-case setting. The subject of tractability is concerned with the dependence of the worst-case integration error on the dimension. Roughly speaking, an integration problem is tractable if the worst-case error does not grow exponentially fast with the dimension. Many classical problems are known to be intractable. However, sometimes tractability can be shown. Often such proofs are based on randomly selected integration nodes. Of course, in applications, true random numbers are not available and hence one mimics them with pseudorandom number generators. This motivates us to propose the use of pseudorandom vectors as underlying integration nodes in order to achieve tractability. In particular, we consider digital inverse vectors and present two examples of problems, the weighted star discrepancy and integration of Hölder continuous, absolute convergent Fourier and cosine series, where the proposed method is successful.
A note on a Wiener-Wintner theorem for mean ergodic Markov amenable semigroups
Authors: Bartoszek Wojciech , Śpiewak Adam
Published: October 2016

We prove a Wiener-Wintner ergodic type theorem for a Markov representation

S

=
{

S
g

:
g
∈
G
}

\mathcal {S} = \{ S_g : g\in G \}

of a right amenable semitopological semigroup

G
G

. We assume that

S

\mathcal {S}

is mean ergodic as a semigroup of linear Markov operators acting on

(
C
(
K
)
,
‖
⋅

‖

sup

)

(C(K), \| \cdot \|_{\sup })

, where

K
K

is a fixed Hausdorff, compact space. The main result of the paper is necessary and sufficient conditions for mean ergodicity of a distorted semigroup

{
χ
(
g
)

S
g

:
g
∈
G
}

\{ \chi (g)S_g : g\in G \}

, where

χ
\chi

is a semigroup character. Such conditions were obtained before under the additional assumption that

S

\mathcal {S}

is uniquely ergodic.
On the congruence subgroup property for GGS-groups
Authors: Fernández-Alcober Gustavo , Garrido Alejandra , Uria-Albizuri Jone
Published: October 2016

We show that all GGS-groups with a non-constant defining vector satisfy the congruence subgroup property. This provides, for every odd primepp, many examples of finitely generated, residually finite, non-torsion groups whose profinite completion is a pro-ppgroup, and among them we find torsion-free groups. This answers a question of Barnea. On the other hand, we prove that the GGS-group with a constant defining vector has an infinite congruence kernel and is not a branch group.
Atomic disintegrations for partially hyperbolic diffeomorphisms
Authors: Homburg Ale
Published: October 2016

Shub and Wilkinson and Ruelle and Wilkinson studied a class of volume preserving diffeomorphisms on the three dimensional torus that are stably ergodic. The diffeomorphisms are partially hyperbolic and admit an invariant central foliation of circles. The foliation is not absolutely continuous; in fact, Ruelle and Wilkinson established that the disintegration of volume along central leaves is atomic. We show that in such a class of volume preserving diffeomorphisms the disintegration of volume along central leaves is a single delta measure. We also formulate a general result for conservative three dimensional skew product like diffeomorphisms on circle bundles, providing conditions for delta measures as disintegrations of the smooth invariant measure.
Strictly convex Wulff shapes and 𝐶¹ convex integrands
Authors: Han Huhe , Nishimura Takashi
Published: October 2016

In this paper, it is shown that a Wulff shape is strictly convex if and only if its convex integrand is of class

C
1

C^1

. Moreover, applications of this result are given.
Soluble Tumor Necrosis Factor Receptors and Arterial Stiffness in Patients With Coronary Atherosclerosis
Authors: Kim Hack-Lyoung , Lee Jung Pyo , An Jung Nam , Kim Jin Hyuk , Lim Woo-Hyun , Seo Jae-Bin , Chung Woo-Young , Oh Yoon Kyu , Kim Yon Su , Lim Chun Soo , Zo Joo-Hee , Kim Myung-A , Kim Sang-Hyun
Published: October 2016

BACKGROUND

Soluble forms of tumor necrosis factor receptors (sTNFRs) are emerging target molecules of inflammatory disease. However, their role in vascular biology is not well known. This study was performed to investigate the association between serum concentrations of sTNFRs and arterial stiffness.

METHODS

A total of 117 consecutive patients with suspected coronary artery disease (CAD) (63.6 ± 11.0 years; men, 65%) who were referred for invasive coronary angiography (ICA) were prospectively enrolled. Arterial blood sTNFR1 and sTNFR2 were measured using commercially available ELISA kits. Brachial-ankle pulse wave velocity (baPWV) measurements were made within 24 hours of blood sampling for sTNFRs measurement.

RESULTS

Most of the patients (86.3%) had significant CAD (stenosis ≥ 50%) in ICA. In simple linear regression analyses, there were significant positive correlations of baPWV with sTNFR1 (r = 0.483, P < 0.001) and sTNFR2 (r = 0.366, P < 0.001). In multiple linear regression analyses, sTNFR1 (β = 0.316, P < 0.001) and sTNFR2 (β = 0.235, P = 0.005) had independent association with baPWV even after controlling for potential confounders.

CONCLUSION

sTNFR1 and sTNFR2 were independently associated with baPWV in patients undergoing ICA. This result may extend previous knowledge on close interactions between inflammation and arterial stiffening.
7. The Global Environment
Authors: Lowe Vaughan
Published: October 2016

Celebrated for their conceptual clarity, titles in the Clarendon Law Series offer concise, accessible overviews of major fields of law and legal thought. This chapter discusses the development of international environmental law. It first considers the Behring Sea Fur Seal arbitration in 1893, as early stirrings of the subject. It then turns to developments after 1945, including the Stockholm Declaration 1972; and the 1992 UN Conference on Environment and Development (UNCED) that resulted in two documents: the Rio Declaration on Environment and Development, which sets out principles designed to reconcile environmental and developmental needs, and Agenda 21, which included proposals on ways to tackle ‘the delicate balance between environmental and developmental concerns’ in the twenty-first century. Next the chapter discusses techniques employed to achieve the aims of international agreements, including prohibitions, setting targets, information and informed consent, environmental impact assessment, licensing, monitoring and reporting, safe procedures and cleaning up, and liability.
8. The Use of Force
Authors: Lowe Vaughan
Published: October 2016

Celebrated for their conceptual clarity, titles in the Clarendon Law Series offer concise, accessible overviews of major fields of law and legal thought. This chapter discusses the use of force in international law. It first considers the early, failed attempts to control the use of force through the Covenant of the League of Nations in 1920 and the 1928 Pact of Paris. It then turns to the post-World War II United Nations Charter that contains a clear and absolute prohibition on the unilateral use of force, except in self-defence. It considers Charter provisions that grant the UN a very wide range of powers, including the power of the Security Council to investigate any situation which might lead to international friction or give rise to a dispute. The chapter goes on to discuss the Law of Armed Conflict or jus in bello.
9. Postscript
Authors: Lowe Vaughan
Published: October 2016

Celebrated for their conceptual clarity, titles in the Clarendon Law Series offer concise, accessible overviews of major fields of law and legal thought. This chapter presents some brief, final thoughts concerning the declining influence of the individual nation-State. It suggests that the power of the State is in decline when measured against the increasing power of other actors, such as international and supranational organizations. The result, however, is not so much an expansion in the scope of international law so as to claim all these other actors as its own, but rather that the boundaries between international law and neighbouring legal subjects are breaking down. The most important point is that all of the ground occupied by international law is shared with others who are not lawyers but men and women in the vast range of other professions and businesses whose cumulative efforts shape the world. While lawyers have a contribution to make going about resolving some of the most crucial problems that face the world, it is only one way among many.
Deletion of the SACPD-C Locus Alters the Symbiotic Relationship Between Bradyrhizobium japonicum USDA110 and Soybean, Resulting in Elicitation of Plant Defense Response and Nodulation Defects
Authors: Krishnan Hari B. , Alaswad Alaa A. , Oehrle Nathan W. , Gillman Jason D.
Published: October 2016

Legumes form symbiotic associations with soil-dwelling bacteria collectively called rhizobia. This association results in the formation of nodules, unique plant-derived organs, within which the rhizobia are housed. Rhizobia-encoded nitrogenase facilitates the conversion of atmospheric nitrogen into ammonia, which is utilized by the plants for its growth and development. Fatty acids have been shown to play an important role in root nodule symbiosis. In this study, we have investigated the role of stearoyl-acyl carrier protein desaturase isoform C (SACPD-C), a soybean enzyme that catalyzes the conversion of stearic acid into oleic acid, which is expressed in developing seeds and in nitrogen-fixing nodules. In-depth cytological investigation of nodule development in sacpd-c mutant lines M25 and MM106 revealed gross anatomical alteration in the sacpd-c mutants. Transmission electron microscopy observations revealed ultrastructural alterations in the sacpd-c mutants that are typically associated with plant defense response to pathogens. In nodules of two sacpd-c mutants, the combined jasmonic acid (JA) species (JA and the isoleucine conjugate of JA) were found to be reduced and 12-oxophytodienoic acid (OPDA) levels were significantly higher relative to wild-type lines. Salicylic acid levels were not significantly different between genotypes, which is divergent from previous studies of sacpd mutant studies on vegetative tissues. Soybean nodule phytohormone profiles were very divergent from those of roots, and root profiles were found to be almost identical between mutant and wild-type genotypes. The activities of antioxidant enzymes, ascorbate peroxidase, and superoxide dismutase were also found to be higher in nodules of sacpd-c mutants. PR-1 gene expression was extremely elevated in M25 and MM106, while the expression of nitrogenase was significantly reduced in these sacpd-c mutants, compared with the parent ‘Bay’. Two-dimensional gel electrophoresis and matrix-assisted laser desorption-ionization time of flight mass spectrometry analyses confirmed sacpd-c mutants also accumulated higher amounts of pathogenesis-related proteins in the nodules. Our study establishes a major role for SACPD-C activity as essential for proper maintenance of soybean nodule morphology and physiology and indicates that OPDA signaling is likely to be involved in attenuation of nodule biotic defense responses.
Measuring speaker-listener neural coupling with functional near infrared spectroscopy
Authors: Liu Yichuan , Piazza Elise A. , Simony Erez , Shewokis Patricia A. , Onaral Banu , Hasson Uri , Ayaz Hasan
Published: October 2016

The present study investigates brain-to-brain coupling, defined as inter-subject correlations in the hemodynamic response, during natural verbal communication. We used functional near-infrared spectroscopy (fNIRS) to record brain activity of speakers telling stories and listeners comprehending audio recordings of these stories. Listeners’ brain activity was correlated with speakers’ with a delay. This between-brain correlation disappeared when verbal communication failed. We further compared the fNIRS and functional Magnetic Resonance Imaging (fMRI) recordings of listeners comprehending the same story and found a relationship between the fNIRS oxygenated-hemoglobin concentration changes and the fMRI BOLD in brain areas associated with speech comprehension. This correlation between fNIRS and fMRI was only present when data from the same story were compared between the two modalities and vanished when data from different stories were compared; this cross-modality consistency further highlights the reliability of the spatiotemporal brain activation pattern as a measure of story comprehension. Our findings suggest that fNIRS is a powerful tool for investigating brain-to-brain coupling during verbal communication. As fNIRS sensors are relatively low-cost and can even be built into wireless, portable, battery-operated systems, these results highlight the potential of broad utilization of this approach in everyday settings for augmenting communication and interaction.
Ring attractor dynamics emerge from a spiking model of the entire protocerebral bridge
Authors: Kakaria Kyobi S. , Bivort Benjamin de
Published: October 2016

Animal navigation is accomplished by a combination of landmark-following and dead reckoning based on estimates of self motion. Both of these approaches require the encoding of heading information, which can be represented as an allocentric or egocentric azimuthal angle. Recently, Ca2+correlates of landmark position and heading direction, in egocentric coordinates, were observed in the ellipsoid body (EB), a ring-shaped processing unit in the fly central complex (Seelig and Jayaraman, 2015). These correlates displayed key dynamics of so-called ring attractors, namely: 1) responsiveness to the position of external stimuli, 2) persistence in the absence of external stimuli, 3) locking onto a single external stimulus when presented with two competitors, 4) stochastically switching between competitors with low probability, and 5) sliding or jumping between positions when an external stimulus moves. We hypothesized that ring attractor-like activity in the EB arises from reciprocal neuronal connections to a related structure, the protocerebral bridge (PB). Using recent light-microscopy resolution catalogues of neuronal cell types in the PB (Wolff et al., 2015; Lin et al., 2013), we determined a connectivity matrix for the PB-EB circuit. When activity in this network was simulated using a leaky-integrate-and-fire model, we observed patterns of activity that closely resemble the reported Ca2+phenomena. All qualitative ring attractor behaviors were recapitulated in our model, allowing us to predict failure modes of the PB ring attractor and the circuit dynamic phenotypes of thermogenetic or optogenetic manipulations. Ring attractor dynamics emerged under a wide variety of parameter configurations, even including non-spiking leaky-integrator implementations. This suggests that the ring-attractor computation is a robust output of this circuit, apparently arising from its high-level network properties (topological configuration, local excitation and long-range inhibition) rather than biological nitty gritty.
The hidden elasticity of avian and mammalian genomes
Authors: Kapusta Aurélie , Suh Alexander , Feschotte Cédric
Published: October 2016

Genome size in mammals and birds shows remarkably little interspecific variation compared to other taxa. Yet, genome sequencing has revealed that many mammal and bird lineages have experienced differential rates of transposable element (TE) accumulation, which would be predicted to cause substantial variation in genome size between species. Thus, we hypothesize that there has been co-variation between the amount of DNA gained by transposition and lost by deletion during mammal and avian evolution, resulting in genome size homeostasis. To test this model, we develop a computational pipeline to quantify the amount of DNA gained by TE expansion and lost by deletion over the last 100 million years (My) in the lineages of 10 species of eutherian mammals and 24 species of birds. The results reveal extensive variation in the amount of DNA gained via lineage-specific transposition, but that DNA loss counteracted this expansion to various extent across lineages. Our analysis of the rate and size spectrum of deletion events implies that DNA removal in both mammals and birds has proceeded mostly through large segmental deletions (>10 kb). These findings support a unified ‘accordion’ model of genome size evolution in eukaryotes whereby DNA loss counteracting TE expansion is a major determinant of genome size. Furthermore, we propose that extensive DNA loss, and not necessarily a dearth of TE activity, has been the primary force maintaining the greater genomic compaction of flying birds and bats relative to their flightless relatives.
High-pressure Seebeck coefficients and thermoelectric behaviors of Bi and PbTe measured using a Paris-Edinburgh cell
Authors: Baker Jason , Kumar Ravhi , Park Changyong , Kenney-Benson Curtis , Cornelius Andrew , Velisavljevic Nenad
Published: October 2016

A new sample cell assembly design for the Paris-Edinburgh type large-volume press for simultaneous measurements of X-ray diffraction, electrical resistance, Seebeck coefficient and relative changes in the thermal conductance at high pressures has been developed. The feasibility of performingin situmeasurements of the Seebeck coefficient and thermal measurements is demonstrated by observing well known solid–solid phase transitions of bismuth (Bi) up to 3 GPa and 450 K. A reversible polarity flip has been observed in the Seebeck coefficient across the Bi-I to Bi-II phase boundary. Also, successful Seebeck coefficient measurements have been performed for the classical high-temperature thermoelectric material PbTe under high pressure and temperature conditions. In addition, the relative change in the thermal conductivity was measured and a relative change in ZT, the dimensionless figure of merit, is described. This new capability enables pressure-induced structural changes to be directly correlated to electrical and thermal properties.
Corporate governance in family businesses from Latin America, Spain and Portugal
Authors: Cortés Diógenes Lagos , Botero Isabel C.
Published: October 2016

Purpose

The purpose of this paper is to summarize what is known about corporate governance in family firms from Ibero-American countries based on published research.

Methodology

The authors conducted a literature search to identify the articles that have been published about the corporate governance of family firms in Latin America, Spain, and Portugal between 1980 and 2014. The authors found 38 articles that provide the sample for this review.

Findings

The results indicate that research on governance in Ibero-American family firms has focussed on understanding structures and processes related to the business and ownership systems. However, generalization of results across the region is difficult because of the lack of systematic approach of studies and the focus on a small number of countries.

Research limitations/implications

There are at least two limitations of this work: the small sample of projects identified for the review and the lack of systematic approach to research. Both of these may be due to the importance given to publishing the university context in this part of the world. As the culture of knowledge changes, the authors expect that research in this area will grow.

Originality/value

Although previous research indicates that cultural characteristics affect governance system choices and understanding of family firms, not many studies explore the importance of culture in governance choices of family firms. This paper provides a baseline of the understanding of governance in Ibero-American family firms, and identifies important area for future research.
Measuring the performance of property management companies in high-rise flats
Authors: C.W. Ho Daniel , Liusman Ervi
Published: October 2016

Purpose

The complex nature of multi-ownership, multi-storey buildings requires the services of property management companies (PMCs). Naturally, homeowners favor PMCs with good performance. Yet, their performances vary. The purpose of this paper is to measure the performance of PMCs in managing high-rise flats using the logic model as the contextual framework with its indicators adapted from the building quality index (BQI) scheme.

Design/methodology/approach

For this pilot study, the research was based on visual inspection and interviews with building management staff for the information concerning the output and outcome indicators. The authors also tested the relationship between outcomes and outputs and other factors that affect the performance of PMCs.

Findings

Based on our pilot study of 41 high-rise residential buildings, the performance outcomes of the PMCs varied considerably. The same PMC was likely to yield different performance outcomes due to unique building characteristics. The outputs, building ages and rehabilitation statuses of the buildings were the contributing factors to the PMCs’ performance outcomes.

Practical implications

The performance outcomes of the logic model can help homeowners and PMCs understand current PMC performance, which can help trigger the development of a strategy to enhance the health and safety of residential buildings in the future.

Originality/value

Unlike traditional performance measurements that use financial figures or balanced scorecards to measure organizational performance, the authors used the logic model performance measurement system because the performance outcomes of the PMCs were explicitly reflected in the physical building conditions. This framework was relatively straightforward and could be applied to cities dominated by multi-ownership, multi-storey apartments.
Organizing without organizations: on informal social activism in Poland
Authors: Polanska Dominika Vergara , Chimiak Galia
Published: October 2016

Purpose

The purpose of this paper is to examine motivations of social activists in informal initiatives and to understand why they opt for this more spontaneous and self-organized activism while openly defying the hitherto established way of founding non-governmental organizations.

Design/methodology/approach

On the basis of a case study of Poland, which had one of the most vibrant civil societies in the socialist region, it is argued that the characteristics ascribed to the functioning of civil society after the toppling of socialism are not reflected in its more recent state. A broader definition of civil society and social activism is suggested to include new types of informal activism, which tend to be over-looked and under-studied. The analysis is built on qualitative and quantitative data gathered in 2014-2015.

Findings

The argument put forward is that un-institutionalized engagement is qualitatively different from its formal and institutionalized counterpart. The recent growth of informal activism is indicative of a rebirth of communitarian engagement in Polish civil society and a reaction to the underside of its institutionalization.

Originality/value

In spite of the seminal role played by societal self-organization in the overturning of the socialist system in Eastern European countries, the development of civil society in the region after 1989 has been repeatedly described as passive and characterized by distrustful or individualist attitudes. However, these civil societies have been changing since, and these more recent developments have been neglected by scholars.
Mobilising and organising in precarious times
Authors: Runciman Carin
Published: October 2016

Purpose

The paper argues that the field of social movement studies has been dominated by a movement organisation-centric approach. This organisational bias has constrained the analysis of collective action, especially in the Global South. The purpose of this paper is to contribute towards a reconceptualization of social movements which links them not to organisations but understanding social movements as a praxis linked to the material experiences of everyday life. Furthermore, the paper uses this expanded definition of social movements to revisit debates about mobilising and organising through reference to the contemporary South African context.

Design/methodology/approach

The empirical findings of the paper are based on ethnographic, qualitative and quantitative research on collective action in South Africa that has been carried out by the author since 2009.

Findings

The paper presents three case studies of collective action which demonstrate the variability, strengths and weaknesses of different forms organising and mobilising in contemporary South Africa.

Originality/value

The paper contributes to re-conceptualising social movements in a way in which the concept is better able to travel across the Global North and South as a heuristic device. Furthermore, the paper situates debates about the strengths of mobilising with and without organisations within the South African context.
Brewing up entrepreneurship: government intervention in beer
Authors: Malone Trey , Lusk Jayson L.
Published: October 2016

Purpose

While previous studies have looked at the negative consequences of beer drinking often as a prelude to discussing benefits of laws that curtail consumption, the purpose of this paper is to understand the downside of such regulations insofar as reducing entrepreneurial activity in the brewing industry.

Design/methodology/approach

Using a unique data set from the Brewers’ Association that contains information on the number and type of brewery in each county, this study explores the relationship between the number of breweries and regulations targeted at the brewing industry. Zero-inflated negative binomial regressions are used to determine the relationship between the number of microbreweries and brewpubs per county and state beer taxes, self-distribution legislation, and on-premises sales.

Findings

The authors find that allowing breweries to sell beers on-premises as well as allowing for breweries to self-distribute have statistically significant relationships with the number of microbreweries, brewpubs, and breweries. The authors do not find an economically significant relationship between state excise taxes and the number of breweries of any type.

Originality/value

Results suggest that whatever public health benefits are brought about by alcohol laws, they are not a free lunch, as they may hinder entrepreneurial development.
Fulfilling the need of business advisory services among Swedish immigrant entrepreneurs
Authors: Kremel Anna
Published: October 2016

Purpose

Taking the entrepreneur’s perspective and a broad view of business advisory services, the purpose of this paper is to examine to what degree the need of business advisory services among Swedish start-ups, first-generation immigrants compared to non-immigrants, is fulfilled.

Design/methodology/approach

The sample data consist of a unique and comprehensive firm-level database and contain telephone interviews with 2,800 Swedish start-up entrepreneurs. The study examines 20 different kinds of business advice services, in terms of both need and use. Statistical methods such as Mann-Whitney test and regression analysis are used while controlling for entrepreneurial characteristics.

Findings

The findings suggest that immigrants’ compared to non-immigrants’ need for business advisory service was not fulfilled. Of the 20 different business advices, ten were fulfilled and ten were not fulfilled. Both strategic advice and operational advice were fulfilled as well as unfulfilled. Apart from ethnicity, other variables did influence the need of business advisory services.

Research limitations/implications

The author was not able to make comparisons between different immigrant groups.

Practical implications

This study offers an explorative approach that contributes on how business advisory services are differentially tailored between start-ups by immigrants and those by non-immigrants. It illustrates to what extent public- and/or private-funded organizations contribute to fulfilment of the needs of immigrant and non-immigrant start-ups.

Originality/value

Few studies take the entrepreneur’s perspective and from such a perspective examine the fulfilment of needs of advice regarding both private and public organizations role in the area. Both the need and the use of business advisory services are studied as well as the kind of business advice that is needed.
Does crime affect entrepreneurship? A discussion of the current literature
Authors: Matti Josh , Ross Amanda
Published: October 2016

Purpose

There are countless factors that affect where an entrepreneur chooses to open a business that have been studied in the literature, including local socio-economic conditions, government policy, and agglomeration economies. One important aspect to the location decision that has not received as much attention from researchers thus far is the impact of crime on entrepreneurship. The purpose of this paper is to discuss the current literature on this topic, with a particular emphasis on the empirical issues present that have likely caused the research in this area to be scarce.

Design/methodology/approach

The authors conduct an analysis of the current state of the literature examining the relationship between crime and entrepreneurship. Looking at what has been done in the past, as well as improvements in the data, the authors discuss what has been done and what can be done in the future.

Findings

The authors discuss areas related to entrepreneurship and crime that the authors see as an emerging literature, based largely on the improvements in data and identification strategies that allow the authors to answer questions that the authors previously could not.

Originality/value

This paper is a review of the current literature, which also discusses areas that future researchers should consider and analyze further.
Foreign aid’s impact on domestic business climates
Authors: Dutta Nabamita , Sobel Russell S. , Roy Sanjukta
Published: October 2016

Purpose

Existing literature has expressed significant pessimism about the outcomes of foreign aid received by developing nations. Foreign aid can lead to negative outcomes by generating greater rent-seeking opportunities and creating aid dependence. While aid’s negative impact has been explored in the context of growth, political institutions, and economic institutions, the literature has not investigated the effect of aid on business climate of recipient nations. The purpose of this paper is to explore foreign aid’s impact on government regulations on the business climate in Sub-Saharan African (SSA) and Middle East and North American countries.

Design/methodology/approach

The authors consider a panel of 64 countries over six years. Since foreign aid is most likely to be endogenous, as identified in most studies, the identification strategy follows two methodologies – system GMM estimator, that creates its own instruments via moment generating conditions and instrumental variable approach that relies on an external instrument.

Findings

The authors find that aid worsens the business climate by increasing government restrictions. Foreign aid provides the recipient governments and the political elite resources to strengthen their power and reinforce predatory policies that are harmful for the business climate. The results further show that in the presence of long-lasting and sustainable democratic regimes, the negative impact of foreign aid on business climate mitigates to a certain extent.

Originality/value

While aid’s negative impact has been explored in the context of growth, political institutions, and economic institutions, the literature has not investigated the effect of aid on business climate of recipient nations. The authors explore the impact of foreign aid on government regulations on the business climate in SSA and Middle East and North American countries.