bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationships among wildfire, prescribed fire, and drought in a fire-prone landscape in the south-eastern United States
Authors: Addington Robert N. , Hudson Stephen J. , Hiers J. Kevin , Hurteau Matthew D. , Hutcherson Thomas F. , Matusick George , Parker James M.
Published: July 2015

Concern over increasing wildfire activity in the last few decades has prompted increased investment in fuels reduction treatments worldwide. Prescribed fire is a commonly used management tool for reducing fuels and modifying subsequent wildfire dynamics, yet the influence of prescribed fire on wildfire is difficult to evaluate empirically due to the often unpredictable nature of wildfire. In this study we evaluated a 30-year record of wildfire, prescribed fire and drought at Fort Benning, a 74 000-ha military training installation in west-central Georgia, USA. Annual wildfire incidence declined sharply from 1982 to 2012 as prescribed fire hectares increased. Multiple regression models including both prescribed fire and drought (assessed using the Keetch–Byram Drought Index; KBDI) explained ~80% and 54% of the variation in annual wildfire incidence and areal extent, respectively. Current- and previous-year prescribed fire were strongly inversely related to current-year wildfire, suggesting that the cumulative area burned by prescription is important in explaining current-year wildfire incidence. Wildfire activity overall (both incidence and areal extent) was highest during drought years when cumulative prescribed fire hectares were low. Our results suggest some inevitability of wildfire during drought, but also provide evidence for the positive effects of sustained landscape-scale prescribed fire in reducing wildfire activity over time.
Dissociation of HSV gL from gH by αvβ6- or αvβ8-integrin promotes gH activation and virus entry
Authors: Gianni Tatiana , Massaro Raffaele , Campadelli-Fiume Gabriella
Published: July 2015

Significance

Entry of enveloped viruses into the cell requires the activation of viral glycoproteins, often mediated by cellular receptors. Herpesviruses infect cells via a multipartite system, which includes species-specific glycoproteins plus conserved apparatus gH/gL and gB. HSV makes use of αvβ6- or αvβ8-integrins as gH/gL receptors. The interaction of HSV gH/gL with integrins resulted in the dissociation of gL. The dissociation took place if all the actors of the entry apparatus were present, i.e., under conditions that lead to glycoprotein activation and virus entry. We propose that (
i
) gL is a regulator of gH and prevents its activation until integrins promote gL dissociation from gH/gL. (
ii
) Dissociation from an inhibitory regulator represents a previously unidentified mechanism of activation of viral fusion glycoproteins.
Adaptive preferences: merging political accounts and well-being accounts
Authors: Terlazzo Rosa
Published: July 2015

Accounts of adaptive preferences are of two kinds: well-being accounts fully theorized for their own sake and political accounts theorized to facilitate the political project of reducing oppression and marginalization. Given their practical role, the latter are often less fully theorized, and are therefore less robust to theoretical criticism. In this paper, I first draw on well-being accounts to identify the well-theorized elements that political accounts should want to adopt in order to strengthen their project and avoid common criticisms. Second, I appeal to the political project to show the shortcomings of the well-being accounts on which I draw.
Influence of Sectioning Location on Age Estimates from Common Carp Dorsal Spines
Authors: Watkins Carson J. , Klein Zachary B. , Terrazas Marc M. , Quist Michael C.
Published: July 2015

Dorsal spines have been shown to provide precise age estimates for Common Carp Cyprinus carpio and are commonly used by management agencies to gain information on Common Carp populations. However, no previous studies have evaluated variation in the precision of age estimates obtained from different sectioning locations along Common Carp dorsal spines. We evaluated the precision, relative readability, and distribution of age estimates obtained from various sectioning locations along Common Carp dorsal spines. Dorsal spines from 192 Common Carp were sectioned at the base (section 1), immediately distal to the basal section (section 2), and at 25% (section 3), 50% (section 4), and 75% (section 5) of the total length of the dorsal spine. The exact agreement and within-1-year agreement among readers was highest and the coefficient of variation lowest for section 2. In general, age estimates derived from sections 2 and 3 had similar age distributions and displayed the highest concordance in age estimates with section 1. Our results indicate that sections taken at ≤ 25% of the total length of the dorsal spine can be easily interpreted and provide precise estimates of Common Carp age. The greater consistency in age estimates obtained from section 2 indicates that by using a standard sectioning location, fisheries scientists can expect age-based estimates of population metrics to be more comparable and thus more useful for understanding Common Carp population dynamics.

Received April 2014; Accepted March 31, 2015
Patient Perceptions of Risky Drinking: Knowledge of Daily and Weekly Low-Risk Guidelines and Standard Drink Sizes
Authors: Sprague Debra J. , Vinson Daniel C.
Published: July 2015

Background

Effective intervention for risky drinking requires that clinicians and patients know low-risk daily and weekly guidelines and what constitutes a “standard drink.” The authors hypothesized that most patients lack this knowledge, and that education is required.

Methods

Following primary care visits, patients completed anonymous exit questionnaires that included the 3 Alcohol Use Disorders Identification Test—Consumption (AUDIT-C) questions, “How many drinks (containing alcohol) can you safely have in one day?” and questions about size, in ounces, of a standard drink of wine, beer, and liquor. Descriptive analyses were done in Stata.

Results

Of 1,331 respondents (60% female, mean age: 49.6, SD = 17.5), 21% screened positive on the AUDIT-C for risky drinking. Only 10% of those accurately estimated daily low-risk limits, with 9% accurate on weekly limits, and half estimated low-risk limits at or below guidelines. Fewer than half who checked “Yes” to “Do you know what a ‘standard drink’ is?” provided accurate answers for beer, wine, or liquor. Patients with a positive screen were twice as likely to say they knew what a standard drink is, but only a third gave accurate estimates. When asked about plans in the next month regarding change in drinking behavior, 23% with a positive AUDIT-C indicated they were at least considering a change.

Conclusions

Most patients in primary care don't know specifics of the National Institute on Alcohol Abuse and Alcoholism (NIAAA) guidelines for low-risk drinking. Exploring patient perceptions of low-risk guidelines and current drinking behavior may reveal discrepancies worth discussing. For risky drinkers, most of whom don't know daily and weekly low-risk guidelines or standard drink sizes, education can be vital in intervening. Findings suggest the need for detailed and explicit social marketing and communication on exactly what low-risk drinking entails.
Anisotropic Short-Wavelength Friedel Oscillation with Adjustable Envelope in Graphene*
Authors: Chen Jian , Xu Huai-Zhe
Published: July 2015

We investigate theoretically the intervalley charge density oscillation and the screened ionic potential in graphene caused by the intervalley scattering. We demonstrate that the contribution from the intervalley scattering is comparable with that from the intravalley scattering, and oscillation rather than decaying dominates at a large distance away from the external impurity. We show that the intervalley oscillation is strongly anisotropic because of the inequivalency between neighboring valleys. The anisotropic oscillation consists of an anisotropic short-wavelength oscillation with an anisotropic fixed wavelength and an isotropic long-wavelength envelop with an isotropic wavelength modulated by doping, making an adjustable-widthed wave-packet propagation. One weakens the screening and gets anisotropic short-wavelength oscillation by introducing short-range mechanism in graphene and graphene-like materials.
Analytical Solution of Partial-Wave Faddeev Equations with Application to Scattering and Statistical Mechanical Properties
Authors: Maghari Ali , Maleki Vahdat Moheb
Published: July 2015

In this work, the Faddeev equations for three-body scattering at arbitrary angular momentum are exactly solved and the transition matrices for some transition processes, including scattering and rearrangement channels are formulated in terms of free-particle resolvent matrix. A generalized Yamaguchi rank-two nonlocal separable potential has been used to obtain the analytical expressions for partial wave scattering properties of a three-particle system. The partial-wave analysis for some transition processes in a three-particle system is suggested. The partial-wave three-particle transition matrix elements have been constructed via knowledge of the matrix elements of the free motion resolvent. The calculation of a number of scattering properties of interest of the system such as transition matrix and its poles (bound states and resonances) and consequently other related quantities like scattering amplitudes, scattering length, phase shifts and cross sections are feasible in a straightforward manner. Moreover, we obtain a new analytical expression for the third virial coefficient in terms of three-body transition matrix.
Reference Section Method for Mixed State Geometric Phase in Nonunitary Evolution*
Authors: Du Guang-Le , Li Tian-Jun
Published: July 2015

We propose the reference section method to obtain a geometric phase for the mixed states in nonunitary evolution. The reference connection on density operator space is defined. That the parallel transport method and reference section method are essentially two aspects of in phase concept is pointed out.
Various Types of Kink and Bright Resonant Soliton Solutions for the (2+1)-Dimensional Double sine-Gordon Equation*
Authors: Lin Ji , Huang Guang-Qiao , Chen Wei-Xiong
Published: July 2015

The algebraic mapping relations between the (2+1)-dimensional double sine-Gordon equation and the cubic nonlinear Klein–Gordon equation are constructed. Many new types of two-dimensional resonant kink, bright soliton and solitoff solutions are obtained, such as broken line shape, “V” shape, “snake” shape and “M” shape solitary waves, Zigzag-curve type, “ω” shape, peroidic-curve type, oscillatory Arch-type and parabolic shape bright soliton waves. We also investigate the propagating properties of some soliton solutions.
Centrality Dependence of Productions for Single Hadrons and Inclusive Jets in High-Energy p + A Collisions with NLO QCD*
Authors: Chen Shi-Yong , Shen Ke-Ming , Dai Wei , Zhang Ben-Wei , Zhang Han-Zhong , Wang En-Ke
Published: July 2015

By using the recent spatially dependent nuclear PDF set EPS09s, we investigated the centrality-dependent Cold Nuclear Matter (CNM) effects for neutral π, η mesons and inclusive jets at RHIC in d+Au collisions and at LHC in p+Pb collisions. The nuclear modification factors as functions of transverse momentum are plotted at different centralities bins respectively. At all fixed centralities, the nuclear modification factors show no significant suppressions, contrast to the strong suppressions observed for central Au+Au collisions. Our results are consistent with the PHENIX preliminary Data in minimum bias and central d+Au collisions. The LHC experimental Data also support our predictions for both single inclusive hadron and inclusive jets productions in central p+Pb collisions. And the centrality dependence of the nuclear suppressions for all the observations in our calculations are lower than the RHIC and LHC Data.
The canonical trace and the noncommutative residue on the noncommutative torus
Authors: Lévy Cyril , Neira Jiménez Carolina , Paycha Sylvie
Published: July 2015

Using a global symbol calculus for pseudodifferential operators on tori, we build a canonical trace on classical pseudodifferential operators on noncommutative tori in terms of a canonical discrete sum on the underlying toroidal symbols. We characterise the canonical trace on operators on the noncommutative torus as well as its underlying canonical discrete sum on symbols of fixed (resp. any) noninteger order. On the grounds of this uniqueness result, we prove that in the commutative setup, this canonical trace on the noncommutative torus reduces to Kontsevich and Vishik’s canonical trace which is thereby identified with a discrete sum. A similar characterisation for the noncommutative residue on noncommutative tori as the unique trace which vanishes on trace–class operators generalises Fathizadeh and Wong’s characterisation in so far as it includes the case of operators of fixed integer order. By means of the canonical trace, we derive defect formulae for regularized traces. The conformal invariance of the

ζ
\zeta

–function at zero of the Laplacian on the noncommutative torus is then a straightforward consequence.
Post-Golgi anterograde transport requires GARP-dependent endosome-to-TGN retrograde transport
Authors: Hirata Tetsuya , Fujita Morihisa , Nakamura Shota , Gotoh Kazuyoshi , Motooka Daisuke , Murakami Yoshiko , Maeda Yusuke , Kinoshita Taroh
Published: July 2015

The importance of endosome-to– trans-Golgi network (TGN) retrograde transport in the anterograde transport of proteins is unclear. In this study, genome-wide screening of the factors necessary for efficient anterograde protein transport in human haploid cells identified subunits of the Golgi-associated retrograde protein (GARP) complex, a tethering factor involved in endosome-to-TGN transport. Knockout (KO) of each of the four GARP subunits, VPS51–VPS54, in HEK293 cells caused severely defective anterograde transport of both glycosylphosphatidylinositol (GPI)-anchored and transmembrane proteins from the TGN. Overexpression of VAMP4, v-SNARE, in VPS54-KO cells partially restored not only endosome-to-TGN retrograde transport, but also anterograde transport of both GPI-anchored and transmembrane proteins. Further screening for genes whose overexpression normalized the VPS54-KO phenotype identified TMEM87A, encoding an uncharacterized Golgi-resident membrane protein. Overexpression of TMEM87A or its close homologue TMEM87B in VPS54-KO cells partially restored endosome-to-TGN retrograde transport and anterograde transport. Therefore GARP- and VAMP4-dependent endosome-to-TGN retrograde transport is required for recycling of molecules critical for efficient post-Golgi anterograde transport of cell-surface integral membrane proteins. In addition, TMEM87A and TMEM87B are involved in endosome-to-TGN retrograde transport.
Regulation of TGF-β receptor hetero-oligomerization and signaling by endoglin
Authors: Pomeraniec Leslie , Hector-Greene Melissa , Ehrlich Marcelo , Blobe Gerard C. , Henis Yoav I.
Published: July 2015

Complex formation among transforming growth factor-β (TGF-β) receptors and its modulation by coreceptors represent an important level of regulation for TGF-β signaling. Oligomerization of ALK5 and the type II TGF-β receptor (TβRII) has been thoroughly investigated, both in vitro and in intact cells. However, such studies, especially in live cells, are missing for the endothelial cell coreceptor endoglin and for the ALK1 type I receptor, which enables endothelial cells to respond to TGF-β by activation of both Smad2/3 and Smad1/5/8. Here we combined immunoglobulin G–mediated immobilization of one cell-surface receptor with lateral mobility studies of a coexpressed receptor by fluorescence recovery after photobleaching (FRAP) to demonstrate that endoglin forms stable homodimers that function as a scaffold for binding TβRII, ALK5, and ALK1. ALK1 and ALK5 bind to endoglin with differential dependence on TβRII, which plays a major role in recruiting ALK5 to the complex. Signaling data indicate a role for the quaternary receptor complex in regulating the balance between TGF-β signaling to Smad1/5/8 and to Smad2/3.
Cardiolipin's propensity for phase transition and its reorganization by dynamin-related protein 1 form a basis for mitochondrial membrane fission
Authors: Stepanyants Natalia , Macdonald Patrick J. , Francy Christopher A. , Mears Jason A. , Qi Xin , Ramachandran Rajesh
Published: July 2015

Cardiolipin (CL) is an atypical, dimeric phospholipid essential for mitochondrial dynamics in eukaryotic cells. Dynamin-related protein 1 (Drp1), a cytosolic member of the dynamin superfamily of large GTPases, interacts with CL and functions to sustain the balance of mitochondrial division and fusion by catalyzing mitochondrial fission. Although recent studies have indicated a role for CL in stimulating Drp1 self-assembly and GTPase activity at the membrane surface, the mechanism by which CL functions in membrane fission, if at all, remains unclear. Here, using a variety of fluorescence spectroscopic and imaging approaches together with model membranes, we demonstrate that Drp1 and CL function cooperatively in effecting membrane constriction toward fission in three distinct steps. These involve 1) the preferential association of Drp1 with CL localized at a high spatial density in the membrane bilayer, 2) the reorganization of unconstrained, fluid-phase CL molecules in concert with Drp1 self-assembly, and 3) the increased propensity of CL to transition from a lamellar, bilayer arrangement to an inverted hexagonal, nonbilayer configuration in the presence of Drp1 and GTP, resulting in the creation of localized membrane constrictions that are primed for fission. Thus we propose that Drp1 and CL function in concert to catalyze mitochondrial division.
Actin remodeling by Nck regulates endothelial lumen formation
Authors: Chaki Sankar P. , Barhoumi Rola , Rivera Gonzalo M.
Published: July 2015

Multiple angiogenic cues modulate phosphotyrosine signaling to promote vasculogenesis and angiogenesis. Despite its functional and clinical importance, how vascular cells integrate phosphotyrosine-dependent signaling to elicit cytoskeletal changes required for endothelial morphogenesis remains poorly understood. The family of Nck adaptors couples phosphotyrosine signals with actin dynamics and therefore is well positioned to orchestrate cellular processes required in vascular formation and remodeling. Culture of endothelial cells in three-dimensional collagen matrices in the presence of VEGF stimulation was combined with molecular genetics, optical imaging, and biochemistry to show that Nck-dependent actin remodeling promotes endothelial cell elongation and proper organization of VE-cadherin intercellular junctions. Major morphogenetic defects caused by abrogation of Nck signaling included loss of endothelial apical-basal polarity and impaired lumenization. Time-lapse imaging using a Förster resonance energy transfer biosensor, immunostaining with phospho-specific antibodies, and GST pull-down assays showed that Nck determines spatiotemporal patterns of Cdc42/aPKC activation during endothelial morphogenesis. Our results demonstrate that Nck acts as an important hub integrating angiogenic cues with cytoskeletal changes that enable endothelial apical-basal polarization and lumen formation. These findings point to Nck as an emergent target for effective antiangiogenic therapy.
Impact of Late Oseltamivir Treatment on Influenza Symptoms in the Outpatient Setting: Results of a Randomized Trial
Authors: McLean Huong Q. , Belongia Edward A. , Kieke Burney A. , Meece Jennifer K. , Fry Alicia M.
Published: July 2015

We conducted a double-blind, randomized trial of 134 outpatients with polymerase chain reaction-confirmed influenza to assess the effects of oseltamivir initiated 48–119 hours after illness onset. Oseltamivir treatment did not reduce illness duration, severity, or duration of virus detection. However, the power of this study was limited due to lower than expected enrollment.
Symptoms of Autonomic Dysfunction in Human Immunodeficiency Virus
Authors: Chow Dominic , Nakamoto Beau K. , Sullivan Katherine , Sletten David M. , Fujii Satomi , Umekawa Sari , Kocher Morgan , Kallianpur Kalpana J. , Shikuma Cecilia M. , Low Phillip
Published: July 2015

This retrospective study evaluated the frequencies of symptoms associated with autonomic dysfunction in human immunodeficiency virus (HIV)-infected patients on stable combined antiretroviral therapy. Patients infected with HIV reported higher frequencies of dysautonomia symptoms compared with HIV-negative patients, particularly in the autonomic domains related to urinary, sleep, gastroparesis, secretomotor, pupillomotor, and male sexual dysfunction.
Neisseria sicca Endocarditis Presenting as Multiple Embolic Brain Infarcts
Authors: Kirlew Christine , Wilmot Kobina , Salinas Jorge L.
Published: July 2015

A 58 year old male presented with a 14 day history of progressive forgetfulness and aggressiveness. He had a history of human immunodeficiency virus infection, ischemic cardiomyopathy, and a myxomatous mitral valve (status post Saint Jude's mitral valve replacement 8 years before presentation). International normalized ratio was supra-therapeatutic on admission. A non-contrast computed tomography of the brain indicated multiple infarcts with hemorrhagic conversion. The source was later found to be a rare case of Neisseria sicca endocarditis.
The costs of avian brood parasitism explain variation in egg rejection behaviour in hosts
Authors: Medina Iliana , Langmore Naomi E.
Published: July 2015

Many bird species can reject foreign eggs from their nests. This behaviour is thought to have evolved in response to brood parasites, birds that lay their eggs in the nest of other species. However, not all hosts of brood parasites evict parasitic eggs. In this study, we collate data from egg rejection experiments on 198 species, and perform comparative analyses to understand the conditions under which egg rejection evolves. We found evidence, we believe for the first time in a large-scale comparative analysis, that (i) non-current host species have rejection rates as high as current hosts, (ii) egg rejection is more likely to evolve when the parasite is relatively large compared with its host and (iii) egg rejection is more likely to evolve when the parasite chick evicts all the host eggs from the nest, such as in cuckoos. Our results suggest that the interactions between brood parasites and their hosts have driven the evolution of egg rejection and that variation in the costs inflicted by parasites is fundamental to explaining why only some host species evolve egg rejection.
The evolution and extinction of the ichthyosaurs from the perspective of quantitative ecospace modelling
Authors: Dick Daniel G. , Maxwell Erin E.
Published: July 2015

The role of niche specialization and narrowing in the evolution and extinction of the ichthyosaurs has been widely discussed in the literature. However, previous studies have concentrated on a qualitative discussion of these variables only. Here, we use the recently developed approach of quantitative ecospace modelling to provide a high-resolution quantitative examination of the changes in dietary and ecological niche experienced by the ichthyosaurs throughout their evolution in the Mesozoic. In particular, we demonstrate that despite recent discoveries increasing our understanding of taxonomic diversity among the ichthyosaurs in the Cretaceous, when viewed from the perspective of ecospace modelling, a clear trend of ecological contraction is visible as early as the Middle Jurassic. We suggest that this ecospace redundancy, if carried through to the Late Cretaceous, could have contributed to the extinction of the ichthyosaurs. Additionally, our results suggest a novel model to explain ecospace change, termed the ‘migration model’.
A hydrodynamic mechanism for attraction of undulatory microswimmers to surfaces (bordertaxis)
Authors: Yuan Jinzhou , Raizen David M. , Bau Haim H.
Published: July 2015

Although small nematodes significantly impact human and animal health, agriculture, and ecology, little is known about the role of hydrodynamics in their life cycles. Using the nematodeCaenorhabditis elegansas a model undulatory microswimmer, we have observed that animals are attracted to and swim along surfaces. The attraction to surfaces does not require mechanosensory neuron function. In dilute swarms, swimmers aggregate near surfaces. Using resistive force-based theory, symmetry arguments, and direct hydrodynamic simulations, we demonstrate that forces resulting from the interaction between the swimmer-induced flow field and a nearby surface cause a short-range hydrodynamic torque that stirs the swimmers towards the surface. When combined with steric forces, this causes locomotion along the surface. This surface attraction may affect nematode mate and food finding behaviour and, in the case of parasitic nematodes, may facilitate host penetration. Surface attraction must be accounted for when studying animals' responses to various stimuli, and suggests means of controlling undulatory microswimmers.
A structural model for thein vivohuman cornea including collagen-swelling interaction
Authors: Cheng Xi , Petsche Steven J. , Pinsky Peter M.
Published: July 2015

A structural model of thein vivocornea, which accounts for tissue swelling behaviour, for the three-dimensional organization of stromal fibres and for collagen-swelling interaction, is proposed. Modelled as a binary electrolyte gel in thermodynamic equilibrium, the stromal electrostatic free energy is based on the mean-field approximation. To account for active endothelial ionic transport in thein vivocornea, which modulates osmotic pressure and hydration, stromal mobile ions are shown to satisfy a modified Boltzmann distribution. The elasticity of the stromal collagen network is modelled based on three-dimensional collagen orientation probability distributions for every point in the stroma obtained by synthesizing X-ray diffraction data for azimuthal angle distributions and second harmonic-generated image processing for inclination angle distributions. The model is implemented in a finite-element framework and employed to predict free and confined swelling of stroma in an ionic bath. For thein vivocornea, the model is used to predict corneal swelling due to increasing intraocular pressure (IOP) and is adapted to model swelling in Fuchs' corneal dystrophy. The biomechanical response of thein vivocornea to a typical LASIK surgery for myopia is analysed, including tissue fluid pressure and swelling responses. The model provides a new interpretation of the corneal active hydration control (pump-leak) mechanism based on osmotic pressure modulation. The results also illustrate the structural necessity of fibre inclination in stabilizing the corneal refractive surface with respect to changes in tissue hydration and IOP.
Cell–cell signalling in sexual chemotaxis: a basis for gametic differentiation, mating types and sexes
Authors: Hadjivasiliou Zena , Iwasa Yoh , Pomiankowski Andrew
Published: July 2015

While sex requires two parents, there is no obvious need for them to be differentiated into distinct mating types or sexes. Yet this is the predominate state of nature. Here, we argue that mating types could play a decisive role because they prevent the apparent inevitability of self-stimulation during sexual signalling. We rigorously assess this hypothesis by developing a model for signaller–detector dynamics based on chemical diffusion, chemotaxis and cell movement. Our model examines the conditions under which chemotaxis improves partner finding. Varying parameter values within ranges typical of protists and their environments, we show that simultaneous secretion and detection of a single chemoattractant can cause a multifold movement impediment and severely hinder mate finding. Mutually exclusive roles result in faster pair formation, even when cells conferring the same roles cannot pair up. This arrangement also allows the separate mating types to optimize their signalling or detecting roles, which is effectively impossible for cells that are both secretors and detectors. Our findings suggest that asymmetric roles in sexual chemotaxis (and possibly other forms of sexual signalling) are crucial, even without morphological differences, and may underlie the evolution of gametic differentiation among both mating types and sexes.
The effect of intramuscular fat on skeletal muscle mechanics: implications for the elderly and obese
Authors: Rahemi Hadi , Nigam Nilima , Wakeling James M.
Published: July 2015

Skeletal muscle accumulates intramuscular fat through age and obesity. Muscle quality, a measure of muscle strength per unit size, decreases in these conditions. It is not clear how fat influences this loss in performance. Changes to structural parameters (e.g. fibre pennation and connective tissue properties) affect the muscle quality. This study investigated the mechanisms that lead to deterioration in muscle performance due to changes in intramuscular fat, pennation and aponeurosis stiffness. A finite-element model of the human gastrocnemius was developed as a fibre-reinforced composite biomaterial containing contractile fibres within the base material. The base-material properties were modified to include intramuscular fat in five different ways. All these models with fat generated lower fibre stress and muscle quality than their lean counterparts. This effect is due to the higher stiffness of the tissue in the fatty models. The fibre deformations influence their interactions with the aponeuroses, and these change with fatty inclusions. Muscles with more compliant aponeuroses generated lower forces. The muscle quality was further reduced for muscles with lower pennation. This study shows that whole-muscle force is dependent on its base-material properties and changes to the base material due to fatty inclusions result in reductions to force and muscle quality.
Social setting, intuition and experience in laboratory experiments interact to shape cooperative decision-making
Authors: Capraro Valerio , Cococcioni Giorgia
Published: July 2015

Recent studies suggest that cooperative decision-making in one-shot interactions is a history-dependent dynamic process: promoting intuition versus deliberation typically has a positive effect on cooperation (dynamism) among people living in a cooperative setting and with no previous experience in economic games on cooperation (history dependence). Here, we report on a laboratory experiment exploring how these findings transfer to a non-cooperative setting. We find two major results: (i) promoting intuition versus deliberation has no effect on cooperative behaviour among inexperienced subjects living in a non-cooperative setting; (ii) experienced subjects cooperate more than inexperienced subjects, but only under time pressure. These results suggest that cooperation is a learning process, rather than an instinctive impulse or a self-controlled choice, and that experience operates primarily via the channel of intuition. Our findings shed further light on the cognitive basis of human cooperative decision-making and provide further support for the recently proposed social heuristics hypothesis.
Population declines of tuna and relatives depend on their speed of life
Authors: Juan-Jordá M. J. , Mosqueira I. , Freire J. , Dulvy N. K.
Published: July 2015

Larger-bodied species in a wide range of taxonomic groups including mammals, fishes and birds tend to decline more steeply and are at greater risk of extinction. Yet, the diversity in life histories is governed not only by body size, but also by time-related traits. A key question is whether this size-dependency of vulnerability also holds, not just locally, but globally across a wider range of environments. We test the relative importance of size- and time-related life-history traits and fishing mortality in determining population declines and current exploitation status in tunas and their relatives. We use high-quality datasets of half a century of population trajectories combined with population-level fishing mortalities and life-history traits. Time-related traits (e.g. growth rate), rather than size-related traits (e.g. maximum size), better explain the extent and rate of declines and current exploitation status across tuna assemblages, after controlling for fishing mortality. Consequently, there is strong geographical patterning in population declines, such that populations with slower life histories (found at higher cooler latitudes) have declined most and more steeply and have a higher probability of being overfished than populations with faster life histories (found at tropical latitudes). Hence, the strong, temperature-driven, latitudinal gradients in life-history traits may underlie the global patterning of population declines, fisheries collapses and local extinctions.
Evolution of protolinguistic abilities as a by-product of learning to forage in structured environments
Authors: Kolodny Oren , Edelman Shimon , Lotem Arnon
Published: July 2015

The skills required for the learning and use of language are the focus of extensive research, and their evolutionary origins are widely debated. Using agent-based simulations in a range of virtual environments, we demonstrate that challenges of foraging for food can select for cognitive mechanisms supporting complex, hierarchical, sequential learning, the need for which arises in language acquisition. Building on previous work, where we explored the conditions under which reinforcement learning is out-competed by seldom-reinforced continuous learning that constructs a network model of the environment, we now show that realistic features of the foraging environment can select for two critical advances: (i)
chunking
of meaningful sequences found in the data, leading to representations composed of units that better fit the prevalent statistical patterns in the environment; and (ii)
generalization
across units based on their contextual similarity. Importantly, these learning processes, which in our framework evolved for making better foraging decisions, had been earlier shown to reproduce a range of findings in language learning in humans. Thus, our results suggest a possible evolutionary trajectory that may have led from basic learning mechanisms to complex hierarchical sequential learning that can support advanced cognitive abilities of the kind needed for language acquisition.
Indirect effects of parasitism: costs of infection to other individuals can be greater than direct costs borne by the host
Authors: Granroth-Wilding Hanna M. V. , Burthe Sarah J. , Lewis Sue , Herborn Katherine A. , Takahashi Emi A. , Daunt Francis , Cunningham Emma J. A.
Published: July 2015

Parasitic infection has a direct physiological cost to hosts but may also alter how hosts interact with other individuals in their environment. Such indirect effects may alter both host fitness and the fitness of other individuals in the host's social network, yet the relative impact of direct and indirect effects of infection are rarely quantified. During reproduction, a host's social environment includes family members who may be in conflict over resource allocation. In such situations, infection may alter how resources are allocated, thereby redistributing the costs of parasitism between individuals. Here, we experimentally reduce parasite burdens of parent and/or nestling European shags (
Phalacrocorax aristotelis
) infected with
Contracaecum
nematodes in a factorial design, then simultaneously measure the impact of an individual's infection on all family members. We found no direct effect of infection on parent or offspring traits but indirect effects were detected in all group members, with both immediate effects (mass change and survival) and longer-term effects (timing of parents’ subsequent breeding). Our results show that parasite infection can have a major impact on individuals other than the host, suggesting that the effect of parasites on population processes may be greater than previously thought.
When and how did the terrestrial mid-Permian mass extinction occur? Evidence from the tetrapod record of the Karoo Basin, South Africa
Authors: Day Michael O. , Ramezani Jahandar , Bowring Samuel A. , Sadler Peter M. , Erwin Douglas H. , Abdala Fernando , Rubidge Bruce S.
Published: July 2015

A mid-Permian (Guadalupian epoch) extinction event at approximately 260 Ma has been mooted for two decades. This is based primarily on invertebrate biostratigraphy of Guadalupian–Lopingian marine carbonate platforms in southern China, which are temporally constrained by correlation to the associated Emeishan Large Igneous Province (LIP). Despite attempts to identify a similar biodiversity crisis in the terrestrial realm, the low resolution of mid-Permian tetrapod biostratigraphy and a lack of robust geochronological constraints have until now hampered both the correlation and quantification of terrestrial extinctions. Here we present an extensive compilation of tetrapod-stratigraphic data analysed by the constrained optimization (CONOP) algorithm that reveals a significant extinction event among tetrapods within the lower Beaufort Group of the Karoo Basin, South Africa, in the latest Capitanian. Our fossil dataset reveals a 74–80% loss of generic richness between the upper
Tapinocephalus
Assemblage Zone (AZ) and the mid-
Pristerognathus
AZ that is temporally constrained by a U–Pb zircon date (CA-TIMS method) of 260.259 ± 0.081 Ma from a tuff near the top of the
Tapinocephalus
AZ. This strengthens the biochronology of the Permian Beaufort Group and supports the existence of a mid-Permian mass extinction event on land near the end of the Guadalupian. Our results permit a temporal association between the extinction of dinocephalian therapsids and the LIP volcanism at Emeishan, as well as the marine end-Guadalupian extinctions.
What you feel is what you see: inverse dynamics estimation underlies the resistive sensation of a delayed cursor
Authors: Takamuku Shinya , Gomi Hiroaki
Published: July 2015

How our central nervous system (CNS) learns and exploits relationships between force and motion is a fundamental issue in computational neuroscience. While several lines of evidence have suggested that the CNS predicts motion states and signals from motor commands for control and perception (forward dynamics), it remains controversial whether it also performs the ‘inverse’ computation, i.e. the estimation of force from motion (inverse dynamics). Here, we show that the resistive sensation we experience while moving a delayed cursor, perceived purely from the change in visual motion, provides evidence of the inverse computation. To clearly specify the computational process underlying the sensation, we systematically varied the visual feedback and examined its effect on the strength of the sensation. In contrast to the prevailing theory that sensory prediction errors modulate our perception, the sensation did not correlate with errors in cursor motion due to the delay. Instead, it correlated with the amount of exposure to the forward acceleration of the cursor. This indicates that the delayed cursor is interpreted as a mechanical load, and the sensation represents its visually implied reaction force. Namely, the CNS automatically computes inverse dynamics, using visually detected motions, to monitor the dynamic forces involved in our actions.
Agonistic reciprocity is associated with reduced male reproductive success within haremic social networks
Authors: Solomon-Lane Tessa K. , Pradhan Devaleena S. , Willis Madelyne C. , Grober Matthew S.
Published: July 2015

While individual variation in social behaviour is ubiquitous and causes social groups to differ in structure, how these structural differences affect fitness remains largely unknown. We used social network analysis of replicate bluebanded goby (
Lythrypnus dalli
) harems to identify the reproductive correlates of social network structure. In stable groups, we quantified agonistic behaviour, reproduction and steroid hormones, which can both affect and respond to social/reproductive cues. We identified distinct, optimal social structures associated with different reproductive measures. Male hatching success (HS) was negatively associated with agonistic reciprocity, a network structure that describes whether subordinates ‘reciprocated’ agonism received from dominants. Egg laying was associated with the individual network positions of the male and dominant female. Thus, males face a trade-off between promoting structures that facilitate egg laying versus HS. Whether this reproductive conflict is avoidable remains to be determined. We also identified different social and/or reproductive roles for 11-ketotestosterone, 17β-oestradiol and cortisol, suggesting that specific neuroendocrine mechanisms may underlie connections between network structure and fitness. This is one of the first investigations of the reproductive and neuroendocrine correlates of social behaviour and network structure in replicate, naturalistic social groups and supports network structure as an important target for natural selection.
Determination of growth stages and metabolic profiles in
Brachypodium distachyon
for comparison of developmental context with Triticeae crops
Authors: Onda Yoshihiko , Hashimoto Kei , Yoshida Takuhiro , Sakurai Tetsuya , Sawada Yuji , Hirai Masami Yokota , Toyooka Kiminori , Mochida Keiichi , Shinozaki Kazuo
Published: July 2015

Brachypodium distachyon
is an emerging model plant for studying biological phenomena in temperate grasses. Study of the growth scale is essential to analyse spatio-temporal changes in molecular factors throughout the life cycle. For sensitive and robust staging based on morphology in
B. distachyon
, we demonstrated the utility of the BBCH (Biologische Bundesanstalt, Bundessortenamt and CHemical industry) scale, which is comparable to the Zadoks scale conventionally used for Triticeae crops. We compared the chronological progression of
B. distachyon
accessions Bd21 and Bd3-1, in addition to the progression of Chinese Spring wheat. The comparison of growth stages illustrates the morphological similarities and differences in the timing of life cycle events. Furthermore, we compared metabolite accumulation patterns across different growth stages and across different stress conditions using a widely targeted metabolome analysis. Metabolic profiling determined commonalities and specificities in chemical properties that were dependent on organisms, growth stages and/or stress conditions. Most metabolites accumulated equivalently in
B. distachyon
and wheat. This qualitative similarity indicated the superiority of
B. distachyon
as a model for Triticeae crops. The growth scale of
B. distachyon
should provide a conceptual framework for comparative analysis and for knowledge integration between this model grass and crops in the Pooideae subfamily.
Does mixed-species flocking influence how birds respond to a gradient of land-use intensity?
Authors: Mammides Christos , Chen Jin , Goodale Uromi Manage , Kotagama Sarath Wimalabandara , Sidhu Swati , Goodale Eben
Published: July 2015

Conservation biology is increasingly concerned with preserving interactions among species such as mutualisms in landscapes facing anthropogenic change. We investigated how one kind of mutualism, mixed-species bird flocks, influences the way in which birds respond to different habitat types of varying land-use intensity. We use data from a well-replicated, large-scale study in Sri Lanka and the Western Ghats of India, in which flocks were observed inside forest reserves, in ‘buffer zones' of degraded forest or timber plantations, and in areas of intensive agriculture. We find flocks affected the responses of birds in three ways: (i) species with high propensity to flock were more sensitive to land use; (ii) different flock types, dominated by different flock leaders, varied in their sensitivity to land use and because following species have distinct preferences for leaders, this can have a cascading effect on followers' habitat selection; and (iii) those forest-interior species that remain outside of forests were found more inside flocks than would be expected by chance, as they may use flocks more in suboptimal habitat. We conclude that designing policies to protect flocks and their leading species may be an effective way to conserve multiple bird species in mixed forest and agricultural landscapes.
Lachancea quebecensis sp. nov., a yeast species consistently isolated from tree bark in the Canadian province of Québec
Authors: Freel Kelle C. , Charron Guillaume , Leducq Jean-Baptiste , Landry Christian R. , Schacherer Joseph
Published: July 2015

A thorough sampling of maple, oak, birch, and apple tree bark in North America yielded a set of isolates that represent a yeast species not yet formally described. The strains obtained were all isolated from the Canadian province of Québec. These four isolates have identical electrophoretic karyotypes, distinct from other species of the genus Lachancea, and are most closely related to the formally recognized species Lachancea thermotolerans according to the D1/D2 domain of the LSU rDNA gene and 5.8S–ITS region. Previous studies revealed the existence of a population of strains closely related to L. thermotolerans, with unique D1/D2 sequences and the ability to grow on melibiose, which is also true for these isolates. The sequences obtained here (for the D1/D2, and 5.8S–ITS region) are identical among the four strains, and in a phylogenetic analysis of the D1/D2 region, the strains form a distinct clade with the previously described population closely related to L. thermotolerans, composed of isolates from Japan, as well as from the provinces of Ontario and Québec in Canada. On the basis of select physiological and phylogenetic characteristics, a novel ascosporogenous yeast species, Lachancea quebecensis sp. nov., is proposed. The type strain LL11_022T ( = CBS 14138T = CLIB 1763T = UCDFST 15-106T) was isolated from maple tree bark in the Station Duchesnay, QC region of Québec, Canada. The MycoBank number is MB811749.
Deinococcus metalli sp. nov., isolated from an abandoned lead-zinc mine
Authors: Feng Guang-Da , Wang Yong-Hong , Li Yan-Xuan , Zhu Hong-Hui
Published: July 2015

An aerobic, non-motile and Gram-staining-positive bacterial strain (1PNM-19T) was isolated from a lead-zinc ore in an abandoned mine and was investigated in a taxonomic study using a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain 1PNM-19T was affiliated to the genus Deinococcus and most closely related to Deinococcus aquatilis DSM 23025T and Deinococcus ficus DSM 19119T. The major respiratory quinone was determined to be menaquinone 8 (MK-8) and the major fatty acids contained summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. A complex polar lipid profile consisted of different unidentified glycolipids and polar lipids, two unidentified aminolipids, an unidentified phosphoglycolipid, phospholipid and aminophospholipid. The genomic DNA G+C content of strain 1PNM-19T was 71.7 ± 0.1 mol%. Based on data from this taxonomic study, strain 1PNM-19T represents a novel species of the genus Deinococcus, for which the name Deinococcus metalli sp. nov. is proposed. The type strain is 1PNM-19T ( = GIMCC 1.654T = CCTCC AB 2014198T = DSM 27521T).