bluuebunny/crossref_metadata_2025 huggingface dataset:
Intermediate energy cross sections for electron-impact vibrational-excitation of pyrimidine
Authors: Jones D. B. , Ellis-Gibbings L. , García G. , Nixon K. L. , Lopes M. C. A. , Brunger M. J.
Published: September 2015

We report differential cross sections (DCSs) and integral cross sections (ICSs) for electron-impact vibrational-excitation of pyrimidine, at incident electron energies in the range 15–50 eV. The scattered electron angular range for the DCS measurements was 15°–90°. The measurements at the DCS-level are the first to be reported for vibrational-excitation in pyrimidine via electron impact, while for the ICS we extend the results from the only previous condensed-phase study [P. L. Levesque, M. Michaud, and L. Sanche, J. Chem. Phys. 122, 094701 (2005)], for electron energies ⩽12 eV, to higher energies. Interestingly, the trend in the magnitude of the lower energy condensed-phase ICSs is much smaller when compared to the corresponding gas phase results. As there is no evidence for the existence of any shape-resonances, in the available pyrimidine total cross sections [Baek et al., Phys. Rev. A 88, 032702 (2013); Fuss et al., ibid. 88, 042702 (2013)], between 10 and 20 eV, this mismatch in absolute magnitude between the condensed-phase and gas-phase ICSs might be indicative for collective-behaviour effects in the condensed-phase results.
Ion thermal effects on slow mode solitary waves in plasmas with two adiabatic ion species
Authors: Nsengiyumva F. , Hellberg M. A. , Mace R. L.
Published: September 2015

Using both the Sagdeev and Korteweg-de Vries (KdV) methods, ion thermal effects on slow mode ion acoustic solitons and double layers are investigated in a plasma with two adiabatic positive ion species. It is found that reducing the gap between the two ion thermal speeds by increasing the relative temperature of the cool ions increases the typical soliton/double layer speeds for all values of the ion-ion density ratio and reduces the range in the density ratio that supports double layers. The effect of increasing the relative cool ion temperature on the soliton/double layer amplitudes depends on the relative densities. For lower values of the ion density ratio, an increase in cool ion temperature leads to a significant decrease in soliton/double layer amplitude, so one may find that solitons of all permissible speeds lie within the range of KdV theory.
Magnetic field controllable electric polarization in Y-type hexaferrite Ba0.5Sr1.5Co2Fe12O22
Authors: Wang Guohua , Cao Shixun , Cao Yiming , Hu Shunbo , Wang Xinyan , Feng Zhenjie , Kang Baojuan , Chai Yisheng , Zhang Jincang , Ren Wei
Published: September 2015

We report the magnetic properties and the magnetoelectric effect in Y-type hexaferrite polycrystalline sample of Ba0.5Sr1.5Co2Fe12O22 (BSCFO). The magnetic critical temperature of BSCFO is 620 K, and the low-temperature helical magnetic order can hold up to 255 K. The isothermal magnetization curves sustain ferromagnetic hysteresis from 10 K to 300 K. Under external magnetic fields, the magnetic field induced electric polarization is observed up to 150 K. The magnitude and the sign of the electric polarization can be controlled by the applied magnetic field. These magnetic and magnetoelectric results provide the promise of the studied new hexaferrite as a potential multiferroic material.
Asymmetric optical transmission in an optomechanical array
Authors: Xiong Hao , Si Liu-Gang , Yang Xiaoxue , Wu Ying
Published: September 2015

Optical cavity combining a mechanical degree of freedom provides a unique platform to implement information transmission and processing via optomechanical effects, and introduces a strong link between nanophotonics and nanomechanics. Here, we study the optical property of a cascaded optomechanical array, which consists of two or more optomechanical systems. We find that the steady states of the optomechanical array have algebraic duality symmetry for the case of two identical optomechanical resonators, which is exactly the embodiment of the spatial symmetry and leads to symmetric optical transmission. Breaking of the algebraic duality symmetry gives rise to different behaviors between the forward and the backward transmission, which can be remarkable under low input power. Our results may have potential application for achieving high precision measurement and on-chip manipulation of light propagation.
Torsional spring is the optimal flexibility arrangement for thrust production of a flapping wing
Authors: Moore M. Nicholas J.
Published: September 2015

While it is understood that flexibility can improve the propulsive performance of flapping wings and fins, the flexibility distribution leading to optimal performance has not been explored. Using 2D small-amplitude theory and a fast Chebyshev method, we examine how thrust depends on the chord-wise distribution of wing stiffness. Through numerical optimization, we find that focusing flexibility at the wing’s front, e.g., through a torsional spring, maximizes thrust. A wing with an optimally chosen spring constant typically generates 36% more thrust than a wing of optimal uniform stiffness. These results may relate to material distributions found in nature, such as insect wings, and may apply to the design of biomimetic swimmers and flyers, such as ornithopters.
Chilean consumers’ perception about animal welfare in dairy production systems: short communication
Authors: Vargas-Bello-Pérez Einar , Riveros José Luis , Köbrich Claus , Álvarez-Melo Pamela Alejandra , Lensink Joop
Published: September 2015

Information on animal welfare and ways that farm animals are kept has gained more and more importance with regard to the consumers’ behaviour and expectations when buying food products. In certain countries, animal welfare is considered as an important extrinsic quality attribute of animal products. Until now, hardly any studies have been conducted in Latin America on consumers’ expectations and knowledge regarding animal welfare aspects of the products they buy. The objective of this study was to determine the knowledge and expectations of consumers in Chile regarding information about dairy production systems and animal welfare, and the main aspects they considered when buying dairy products. A face-to-face interview was conducted on a sample of 501 persons from the Province of Santiago, Chile. The survey was conducted in major supermarkets from 15 different municipalities of Santiago in November and December 2012. The main aspects considered before purchasing dairy products were fat content (30%) and price (26%). It was shown that 66.9% of the participants associated the term animal welfare with responsible pet ownership, 12.4% to farm animal care, 11.6% to vegetarianism and 9.2% to the freedom and nature of animals. Age, educational level and family income were related (P < 0.001) to responsible pet ownership whereas gender did not relate to the concept of animal welfare. From the total surveyed participants, 73% were interested in receiving more information about animal welfare; 62% of these were women between 18 and 30 years of age. Information about the conditions of milk production and animal welfare were considered to be an important aspect to be included in dairy products’ labelling for 86% of the participants. Also, 68% of the participants declared a willingness to pay more for an animal welfare friendly dairy product. Data from this study may be useful in order to include animal welfare as an extrinsic quality attribute of dairy products in Chile and to define a market-oriented strategy including animal welfare.
Influence of dietary glutamine supplementation on performance, biochemical indices and enzyme activities in broilers with cold-induced ascites
Authors: Fathi Mokhtar , Heidari Mohammad , Ahmadisefat Ali Asghar , Habibian Mahmood , Moeini Mohammad Mehdi
Published: September 2015

This study was conducted to investigate the effects of dietary glutamine supplementation on performance and biochemical indices of broilers with cold-induced ascites. A total of 240 1-day-old male broiler chicks (Ross 308) were randomly allotted to three treatment groups, with four replicate pens per treatment and 20 birds per pen. The control birds were kept in a thermoneutral chamber and fed a basal diet, whereas the other two experimental groups were kept in a cold chamber to induce ascites and fed the basal diet supplemented with either 0 or 100 mg of glutamine/kg. The cold-treated birds consumed less (P < 0.05) feed and had lower (P < 0.05) weight gain compared with the control birds. Dietary glutamine supplementation had no effect (P > 0.05) on broiler performance. The cold-treated birds had higher (P < 0.05) right ventricle to total ventricle ratio and mortality due to ascites compared with the control birds. However, mortality due to ascites and right ventricle to total ventricle ratio was reduced (P < 0.05) by dietary glutamine supplementation. The cold-treated birds had higher (P < 0.05) red blood cell counts, haematocrit percentage and haemoglobin concentration compared with the control birds at 21 and 42 days of age. The activities of plasma lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase were increased (P < 0.05) in cold-treated birds compared with the control birds at 42 days of age, but dietary glutamine supplementation reduced (P < 0.05) the activities of alanine aminotransferase and aspartate aminotransferase near to the control levels. The plasma and liver glutathione peroxidase activities were increased (P < 0.05) in cold-treated birds compared with the control birds at 21 and 42 days of age, whereas the reverse was true for malondialdehyde concentrations. The glutathione peroxidase activity was increased (P < 0.05), whereas the malondialdehyde concentration was decreased (P < 0.05) by dietary glutamine supplementation compared with the cold-treated birds at 42 days of age. The results indicated that the beneficial effect of glutamine is probably related to its ability to maintain near to normal free radical scavenging enzymes and the level of glutathione peroxidase bioactivity, thereby protecting cell membranes from oxidative damage via decreased lipid peroxidation.
Developing a habitat classification typology for subtidal habitats in a temperate estuary in New South Wales, Australia
Authors: Davis Tom R. , Harasti David , Smith Stephen D. A.
Published: September 2015

Effective estuarine management depends on adequate data about the ecology, extent and biodiversity of component habitats. However, these data are often scant, as exemplified by the Port Stephens estuary, part of the Port Stephens–Great Lakes Marine Park (NSW, Australia), for which even basic descriptions of habitat types and extent are lacking. Herein we present the results of the first quantitative assessment of subtidal benthic communities within the estuary, involving 130km of towed video transects over an area exceeding 50km2. We identified previously undocumented macroalgae-dominated habitat types and found strong correlations between habitat types and depth. The soft coral Dendronephthya australis habitat is of particular interest because this was found to occur exclusively outside current sanctuary (no take) zones. The habitat map of Port Stephens generated during the study provides the basis for more objective representative planning in future iterations of zoning in the estuarine section of the marine park. The study also suggests that depth may be a useful proxy for estuarine habitat types where specific data are lacking. The classification methodology developed during the study was cost-effective, generated robust data and consequently has potential for wider application in other large estuarine bays.
The varying value of a friendly face: Experimentally induced stress is associated with higher preferences for friendship with people possessing feminine versus masculine face traits
Authors: Little Anthony C. , Harcus Kerry
Published: September 2015

Social support can provide a buffer to the negative consequences of stress. Previous research suggests that stress can promote affiliative and cooperative behaviours in those who are stressed. Here we examined how stress might influence who we choose to affiliate with. We measured preferences for friendships with friendly appearing feminized faces versus less friendly appearing masculinized faces after individuals undertook a stressful laboratory task. Stressed individuals had increased preferences for friendships with people with feminine faces. These data demonstrate that individuals prefer more friendly appearing feminine faced people as friends when stressed than when not stressed. This preference is likely adaptive in directing individuals towards others who are most likely to provide social support when it is needed and so reflect strategic friendship preferences.
Instruction-driven processing in human perceptual learning
Authors: Navarro Anton , Arriola Naiara , Alonso Gumersinda
Published: September 2015

We conducted a series of experiments to determine the relative contribution of unsupervised versus controlled mechanisms to the intermixed-blocked effect. In Experiment 1, participants received pre-exposure instructions prompting a search for differences between stimuli, in keeping with past studies, and the intermixed-blocked effect was observed. In the remaining experiments, participants did not receive the aforementioned instructions, but instead were instructed either to simply observe the stimuli (Experiment 2) or in relation to a masking task (Experiment 3). None of the latter experiments produced an intermixed-blocked effect, suggesting that the effect found in Experiment 1 was driven by the instructions to search for differences, consistent with a controlled processing account of the effect. Moreover, we tested a prediction assuming the operation of a search strategy against one assuming the operation of a short-term habituation mechanism and found evidence more consistent with the search strategy hypothesis. We formulate a new account of the intermixed-blocked effect in humans based on an instruction-driven search and discuss how the account could explain many findings in the human literature.
Commentary on the Kervaire–Milnor correspondence 1958–1961
Authors: Ranicki Andrew , Weber Claude
Published: September 2015

The extant letters exchanged between Kervaire and Milnor during their collaboration from 1958–1961 concerned their work on the classification of exotic spheres, culminating in their 1963 Annals of Mathematics paper. Michel Kervaire died in 2007; for an account of his life, see the obituary by Shalom Eliahou, Pierre de la Harpe, Jean-Claude Hausmann, and Claude Weber in the September 2008 issue of the Notices of the American Mathematical Society. The letters were made public at the 2009 Kervaire Memorial Conference in Geneva. Their publication in this issue of the Bulletin of the American Mathematical Society is preceded by our commentary on these letters, providing some historical background.
Lois de réciprocité supérieures et points rationnels
Authors: Colliot-Thélène J.-L. , Parimala R. , Suresh V.
Published: September 2015

Soit

K
=

C

(
(
x
,
y
)
)

K=\mathbb {C}((x,y))

ou

K
=

C

(
(
x
)
)
(
y
)

K=\mathbb {C}((x))(y)

. Soit

G
G

un

K
K

-groupe algébrique linéaire connexe. Il a été établi que si

G
G

est

K
K

-rationnel, c’est-à-dire de corps des fonctions transcendant pur sur

K
K

, si un espace principal homogène sous

G
G

a des points rationnels dans tous les complétés de

K
K

par rapport aux valuations de

K
K

, alors il a un point rationnel. Nous montrons ici qu’en général l’hypothèse de

K
K

-rationalité ne peut être omise. Nous utilisons pour cela une obstruction d’un nouveau type, fondée sur les lois de réciprocité supérieure sur un schéma de dimension deux. Nous donnons aussi une famille d’espaces principaux homogènes pour laquelle cette obstruction raffinée à l’existence d’un point rationnel est la seule obstruction.

Abstract Let

K
=

C

(
(
x
,
y
)
)

K=\mathbb {C}((x,y))

or

K
=

C

(
(
x
)
)
(
y
)

K=\mathbb {C}((x))(y)

. Let

G
G

be a connected linear algebraic group over

K
K

. Under the assumption that the

K
K

-variety

G
G

is

K
K

-rational, i.e. that the function field is purely transcendental, it was proved that a principal homogeneous space of

G
G

has a rational point over

K
K

as soon as it has one over each completion of

K
K

with respect to a valuation. In this paper we show that one cannot in general do without the

K
K

-rationality assumption. To produce our examples, we introduce a new type of obstruction. It is based on higher reciprocity laws on a 2-dimensional scheme. We also produce a family of principal homogeneous spaces for which the refined obstruction controls exactly the existence of rational points.
ABIF Manager: simple reading and editing of ABIF formatted files
Authors: Beran Pavel , Mraz Ivan
Published: September 2015

Summary: ABIF Manager is simple application for low-level access to ABIF formatted files. Those are produced by Data Collection software based on the data, collected from capillary sequencing machine. The application shows all the data as readable text, which can be easily edited.

Availability and implementation: The program source code and compiled executable is freely available at: https://sourceforge.net/projects/abifmanager/

Contact:  pavel.beran@centrum.cz
Anxiety states
Authors: Clark David M.
Published: September 2015

This chapter discusses anxiety states, including panic and generalized anxiety. It defines the nature of anxiety (types of anxiety state, prevalence, mode of onset, method of presentation), cognitive models of anxiety states (levels of cognition, cognitive model of generalized anxiety, and the cognitive model of panic), the assessment of anxiety, suitability for treatment, and descriptions of treatment methods.
Somatic problems
Authors: Salkovskis Paul M.
Published: September 2015

Chapter 7 explores somatic problems, their nature, methods of assessment (general assessment, self-monitoring, questionnaires, and psychological measurements), treatment (underlying principles, techniques), treatment techniques for specific disorders (headache, insomnia, irritable bowel), and difficulties that may occur in the process of treatment.
Eating disorders
Authors: Fairburn Christopher G. , Cooper Peter J.
Published: September 2015

Chapter 8 discusses eating disorders, and focuses on anorexia nervosa and bulimia nervosa. It outlines their clinical features, stages of cognitive–behavioural treatment methods (including the elimination of dieting, cognitive restructuring, addressing cognitive distortions, problem-solving training, and addressing body image misperception), subgroups of patients with bulimia nervosa that may require special consideration, group therapy, in-patient treatment, and the use of drugs in treatment.
Chronic psychiatric handicaps
Authors: Hall John
Published: September 2015

Chapter 9 discusses chronic psychiatric problems, such as schizophrenia, and outlines the causes and maintaining factors, assessment, and treatments for these problems (including cognitive–behavioural treatment in groups, individual programs designed for specific patients, and treatment of in-patients).
Marital problems
Authors: Schmaling Karen B. , Fruzzetti Alan E. , Jacobson Neil S.
Published: September 2015

Chapter 10 explores a view of cognitive–behavioural marital therapy as it might be applied to the short-term treatment of marital problems in any out-patient service. It discusses the causes of marital distress, assessment of problems and assessment of suitability, treatment structure and techniques.
Social Phobia
Authors: McLean Peter D. , Woody Sheila R.
Published: September 2015

This chapter first discusses the continuum of social anxiety, beginning with shyness, and reviews many of the complex issues associated with the psychopathology of social phobia, including cognitive features and behavioral manifestations of the disorder, as well as biological findings. Many new tools for assessing social phobia have been developed, and these will be discussed as they apply to clinical practice, including social skills training, exposure-based approaches, and cognitive techniques.
Posttraumatic Stress Disorder
Authors: McLean Peter D. , Woody Sheila R.
Published: September 2015

This chapter outlines posttraumatic stress disorder (PTSD), its conceptualization (phenomenology, diagnostic trends, prevalence and course), theoretical perspectives, assessment (diagnosis, assessment of symptoms, and assessment of contextual factors), treatment models and guidelines (cognitive behavioral therapy (CBT) for PTSD, pharmacological treatment, eye-movement desensitization and reprocessing (EMDR), and client-treatment matching).
Standards for Quality Care
Authors: McLean Peter D. , Woody Sheila R.
Published: September 2015

This chapter discusses concrete steps for evaluating and improving quality of care. It first discusses ‘quality’ as a concept, reviewing indicators of good care at various levels of analysis, followed by recommendations for how to improve client outcomes at a local level, for instance, within a group practice. Finally, because suggestions for making improvements in patient care necessarily bring up the topic of changing practice patterns, some ways to learn new interventions and to influence one’s colleagues to make positive changes are explored.
Adolescent Well-Being: Building Young People’s Resources
Authors: Frydenberg Erica , Lewis Ramon
Published: September 2015

This chapter considers the ways in which a theory of coping can be used as a platform from which to explore adolescent health and well-being. It outlines conceptualizations and models of coping and puts forward an integrated model which takes into account many of the research paradigms that relate to coping. It emphasizes the role that coping may place in enhancing the quality of life of young people.
Facilitators and Barriers to Participation in a Peer Support Intervention for Veterans With Chronic Pain
Authors: Matthias Marianne S. , Kukla Marina , McGuire Alan B. , Damush Teresa M. , Gill Nabiha , Bair Matthew J.
Published: September 2015

Objective:

To understand facilitators and barriers to participation in a peer support intervention for self-management of chronic pain.

Methods:

After completing a pilot intervention study, peer coaches and their veteran patients took part in a qualitative, semistructured interview to explore their experiences with the intervention. Data were analyzed using an immersion/crystallization approach.

Results:

Three facilitators and 2 barriers to patient participation in a peer support intervention for veterans with chronic pain emerged. Facilitators were (1) having a shared identity as veterans, (2) being partnered with a person who also has chronic pain, and (3) support from the study staff. Barriers were (1) logistical challenges, and (2) challenges to motivation and engagement in the intervention.

Discussion:

Awareness of facilitators and barriers to participation in a peer-supported self-management program for chronic pain, as well as strategies to capitalize on facilitators and mitigate barriers, are essential for further study and ultimate clinical implementation of such a program.
Role of high-fat diet on the effect of pioglitazone and melatonin in a rat model of breast cancer
Authors: Bojková Bianka , Orendáš Peter , Kajo Karol , Kubatka Peter , Výbohová Desanka , Bálentová Soňa , Kružliak Peter , Zulli Anthony , Demečková Vlasta , Péč Martin , Adamkov Marián
Published: September 2015

The risk of cancer may be modulated by drugs with pleiotropic effects and diet has been implicated in the efficacy of treatment. The oncopreventive effects of the antidiabetic drug pioglitazone (PIO) and the anti-insomnia drug melatonin (MT), in vivo, have been proven before, but using a standard-type diet. This study evaluated the impact of a high-fat diet on their efficacy in chemically induced mammary carcinogenesis in Sprague–Dawley rats. Mammary tumours were induced by N-methyl-N-nitrosourea (50 mg/kg, intraperitoneal, on the 41st postnatal day). PIO and MT administration was initiated 11 days before the carcinogen application and lasted until the termination of the experiment at 16 weeks. PIO was administered in a diet (10% fat) at a concentration of 100 ppm and MT was administered in tap water (20 mg/l). PIO, MT and the combination did not significantly alter the basic tumour growth parameters. However, histopathology showed a decrease in the high-grade/low-grade tumour ratio, particularly in animals that received combined treatment (P<0.01). Semiquantitative immunohistochemistry indicated the proapoptotic effect of chemoprevention, particularly in the drug combination group (P<0.01), but no changes in tumour cell proliferation and angiogenesis were recorded. Results were evaluated by one-way analysis of variance or the Mann–Whitney U-test, respectively. PIO and MT, alone or in combination, administered to rats fed a high-fat diet reduced the proportion of high-grade tumours and promoted apoptosis in an in-vivo breast cancer model, although it did not suppress tumour growth. The impact of high dietary fat content on the chemopreventive efficacy of these and other substances should be considered in human studies.
Anti-Warburg effect of rosmarinic acid via miR-155 in colorectal carcinoma cells
Authors: Xu Yichun , Han Shuai , Lei Kesheng , Chang Xinnan , Wang Ke , Li Zhou , Liu Jianwen
Published: September 2015

The Warburg effect, glycolytic production of ATP under aerobic conditions, is found to be a universal feature of most cancer cells. Our study was aimed to determine whether rosmarinic acid (RA) had the anti-Warburg effect activity against colorectal carcinoma. Furthermore, the mechanism for the anti-Warburg effect by RA would be investigated. In our study, we found that RA suppressed glucose consumption and lactate generation in colorectal carcinoma cells; meanwhile, RA inhibited the expression of transcription factor hypoxia-inducible factor-1α (HIF-1α) that affects the glycolytic pathway. Chronic inflammation is a key promoting factor of the Warburg effect. As we supposed, the present study also showed that RA could not only repress proinflammatory cytokines using enzyme-linked immunosorbent assay but it could also suppress microRNAs related to inflammation by real-time PCR. Therefore, we proposed that RA may inhibit the Warburg effect by suppressing the inflammatory response of colorectal carcinoma cells. Recent studies have provided evidence that miR-155 was an important mediator between inflammation and carcinogenesis. We further showed that miR-155 acted to repress the Warburg effect through the mechanism of inactivating the IL-6/STAT3 pathway. Above all, RA might be a potential therapeutic agent against colorectal carcinoma.
Magnetic Resonance Enterography Healing and Magnetic Resonance Enterography Remission Predicts Improved Outcome in Pediatric Crohn Disease
Authors: Sauer Cary G. , Middleton Jeremy P. , McCracken Courtney , Loewen Jonathan , Braithwaite Kiery , Alazraki Adina , Martin Diego R. , Kugathasan Subra
Published: September 2015

Background:

Mucosal healing predicts clinical remission and improved outcomes in patients with Crohn disease (CD). Magnetic resonance enterography (MRE) is a noninvasive imaging modality that can assess small and large bowel wall inflammation. Evidence suggests that MRE may be an acceptable alternative to evaluate mucosal healing over endoscopy. Our objective is to determine whether MRE remission predicts clinical remission at follow‐up in children with CD.

Methods:

We performed an institutional review board–approved retrospecitve chart review using our prospectively maintained MRE CD database. Inclusion criteria were all children who underwent an MRE more than 6 months after diagnosis with CD who had follow‐up of at least 1 year from imaging.

Results:

A total of 101 children with CD underwent MRE, a median of 1.3 years from diagnosis with a median follow‐up of 2.8 years after MRE. Active inflammation was detected in 65 MRE studies, whereas 36 MRE studies demonstrated MRE remission. A total of 88.9% of children demonstrating MRE remission were in clinical remission at follow‐up, whereas only 44.6% of those demonstrating MRE active inflammation achieved clinical remission. Children demonstrating MRE‐active inflammation were more likely to have a change in medication (44.6% vs 8.3%) and more likely to undergo surgery (18.5% vs 2.8%).

Conclusions:

MRE remission is associated with clinical remission at follow‐up at least 1 year after MRE. MRE remission was associated with fewer medication changes and fewer surgeries suggesting that, similar to endoscopic remission, MRE remission demonstrates improved outcome. Additional research is needed to confirm that MRE can be used as a surrogate for mucosal healing.
No fever and leucocytosis in response to a lipopolysaccharide challenge in an insectivorous bat
Authors: Stockmaier Sebastian , Dechmann Dina K. N. , Page Rachel A. , O'Mara M. Teague
Published: September 2015

Bat immune systems may allow them to respond to zoonotic agents more efficiently than other mammals. As the first line of defence, the taxonomically conserved acute phase immune reaction of leucocytosis and fever is crucial for coping with infections, but it is unknown if this response is a key constituent to bat immunological success. We investigated the acute phase reaction to a standard lipopolysaccharide (LPS) challenge in Pallas's mastiff bats (
Molossus molossus
). Challenged bats lost mass, but in contrast to other mammals showed no leucocytosis or fever. There also was no influence on body temperature reduction during torpor. When compared to recent genome-wide assays for constituent immune genes, this lack of a conserved fever response to LPS contributes to a clearer understanding of the innate immune system in bat species and of the coevolution of bats with a wide diversity of pathogens.
Quantifying noise in mass spectrometry and yeast two-hybrid protein interaction detection experiments
Authors: Annibale A. , Coolen A. C. C. , Planell-Morell N.
Published: September 2015

Protein interaction networks (PINs) are popular means to visualize the proteome. However, PIN datasets are known to be noisy, incomplete and biased by the experimental protocols used to detect protein interactions. This paper aims at understanding the connection between true protein interactions and the protein interaction datasets that have been obtained using the most popular experimental techniques, i.e. mass spectronomy and yeast two-hybrid. We start from the observation that the adjacency matrix of a PIN, i.e. the binary matrix which defines, for every pair of proteins in the network, whether or not there is a link, has a special form, that we call separable. This induces precise relationships between the moments of the degree distribution (i.e. the average number of links that a protein in the network has, its variance, etc.) and the number of short loops (i.e. triangles, squares, etc.) along the links of the network. These relationships provide powerful tools to test the reliability of datasets and hint at the underlying biological mechanism with which proteins and complexes recruit each other.
Competition for space during bacterial colonization of a surface
Authors: Lloyd Diarmuid P. , Allen Rosalind J.
Published: September 2015

Competition for space is ubiquitous in the ecology of both microorganisms and macro-organisms. We introduce a bacterial model system in which the factors influencing competition for space during colonization of an initially empty habitat can be tracked directly. Using fluorescence microscopy, we follow the fate of individual
Escherichia coli
bacterial cell lineages as they undergo expansion competition (the race to be the first to colonize a previously empty territory), and as they later compete at boundaries between clonal territories. Our experiments are complemented by computer simulations of a lattice-based model. We find that both expansion competition, manifested as differences in individual cell lag times, and boundary competition, manifested as effects of neighbour cell geometry, can play a role in colonization success, particularly when lineages expand exponentially. This work provides a baseline for investigating how ecological interactions affect colonization of space by bacterial populations, and highlights the potential of bacterial model systems for the testing and development of ecological theory.
Interactional leader–follower sensorimotor communication strategies during repetitive joint actions
Authors: Candidi Matteo , Curioni Arianna , Donnarumma Francesco , Sacheli Lucia Maria , Pezzulo Giovanni
Published: September 2015

Non-verbal communication is the basis of animal interactions. In dyadic leader–follower interactions, leaders master the ability to carve their motor behaviour in order to ‘signal’ their future actions and internal plans while these signals influence the behaviour of follower partners, who automatically tend to imitate the leader even in complementary interactions. Despite their usefulness, signalling and imitation have a biomechanical cost, and it is unclear how this cost–benefits trade-off is managed during repetitive dyadic interactions that present learnable regularities. We studied signalling and imitation dynamics (indexed by movement kinematics) in pairs of leaders and followers during a repetitive, rule-based, joint action. Trial-by-trial Bayesian model comparison was used to evaluate the relation between signalling, imitation and pair performance. The different models incorporate different hypotheses concerning the factors (past interactions versus online movements) influencing the leader's signalling (or follower's imitation) kinematics. This approach showed that (i) leaders' signalling strategy improves future couple performance, (ii) leaders used the history of past interactions to shape their signalling, (iii) followers' imitative behaviour is more strongly affected by the online movement of the leader. This study elucidates the ways online sensorimotor communication help individuals align their task representations and ultimately improves joint action performance.
Pointillist rendering of electron charge and spin density suffices to replicate trends in atomic properties
Authors: Ekesan Solen , Herzfeld Judith
Published: September 2015

The monotonic and non-monotonic variations of atomic properties within and between the rows of the periodic table underlie our understanding of chemistry and accounting for these variations has been a signature strength of quantum mechanics (QM). However, the computational burden of QM motivates the development of more efficient means of describing electrons and reactivity. The recently developed LEWIS
•
model incorporates lessons learnt from QM into a force field that includes electrons as explicit pseudo-classical particles. Here, we extend LEWIS
•
across the 2
p
and 3
p
elements, and show that it is capable of reproducing both monotonic and non-monotonic variations of chemically important atomic properties in a cost-effective manner. An indicator of the strength of the construct is the ability of pairwise potentials trained on ionization energies and the order of spin configurations to predict atomic polarizabilities. In this manner, some insights of QM are uncoupled from its onerous computational burden.
Biotic replacement and mass extinction of the Ediacara biota
Authors: Darroch Simon A. F. , Sperling Erik A. , Boag Thomas H. , Racicot Rachel A. , Mason Sara J. , Morgan Alex S. , Tweedt Sarah , Myrow Paul , Johnston David T. , Erwin Douglas H. , Laflamme Marc
Published: September 2015

The latest Neoproterozoic extinction of the Ediacara biota has been variously attributed to catastrophic removal by perturbations to global geochemical cycles, ‘biotic replacement’ by Cambrian-type ecosystem engineers, and a taphonomic artefact. We perform the first critical test of the ‘biotic replacement’ hypothesis using combined palaeoecological and geochemical data collected from the youngest Ediacaran strata in southern Namibia. We find that, even after accounting for a variety of potential sampling and taphonomic biases, the Ediacaran assemblage preserved at Farm Swartpunt has significantly lower genus richness than older assemblages. Geochemical and sedimentological analyses confirm an oxygenated and non-restricted palaeoenvironment for fossil-bearing sediments, thus suggesting that oxygen stress and/or hypersalinity are unlikely to be responsible for the low diversity of communities preserved at Swartpunt. These combined analyses suggest depauperate communities characterized the latest Ediacaran and provide the first quantitative support for the biotic replacement model for the end of the Ediacara biota. Although more sites (especially those recording different palaeoenvironments) are undoubtedly needed, this study provides the first quantitative palaeoecological evidence to suggest that evolutionary innovation, ecosystem engineering and biological interactions may have ultimately caused the first mass extinction of complex life.
Fossil evidence for a herbaceous diversification of early eudicot angiosperms during the Early Cretaceous
Authors: Jud Nathan A.
Published: September 2015

Eudicot flowering plants comprise roughly 70% of land plant species diversity today, but their early evolution is not well understood. Fossil evidence has been largely restricted to their distinctive tricolpate pollen grains and this has limited our understanding of the ecological strategies that characterized their primary radiation. I describe megafossils of an Early Cretaceous eudicot from the Potomac Group in Maryland and Virginia, USA that are complete enough to allow reconstruction of important life-history traits. I draw on quantitative and qualitative analysis of functional traits, phylogenetic analysis and sedimentological evidence to reconstruct the biology of this extinct species. These plants were small and locally rare but widespread, fast-growing herbs. They had complex leaves and they were colonizers of bright, wet, disturbance-prone habitats. Other early eudicot megafossils appear to be herbaceous rather than woody, suggesting that this habit was characteristic of their primary radiation. A mostly herbaceous initial diversification of eudicots could simultaneously explain the heretofore sparse megafossil record as well as their rapid diversification during the Early Cretaceous because the angiosperm capacity for fast reproduction and fast evolution is best expressed in herbs.
Self-organizing dominance hierarchies in a wild primate population
Authors: Franz Mathias , McLean Emily , Tung Jenny , Altmann Jeanne , Alberts Susan C.
Published: September 2015

Linear dominance hierarchies, which are common in social animals, can profoundly influence access to limited resources, reproductive opportunities and health. In spite of their importance, the mechanisms that govern the dynamics of such hierarchies remain unclear. Two hypotheses explain how linear hierarchies might emerge and change over time. The ‘prior attributes hypothesis’ posits that individual differences in fighting ability directly determine dominance ranks. By contrast, the ‘social dynamics hypothesis’ posits that dominance ranks emerge from social self-organization dynamics such as winner and loser effects. While the prior attributes hypothesis is well supported in the literature, current support for the social dynamics hypothesis is limited to experimental studies that artificially eliminate or minimize individual differences in fighting abilities. Here, we present the first evidence supporting the social dynamics hypothesis in a wild population. Specifically, we test for winner and loser effects on male hierarchy dynamics in wild baboons, using a novel statistical approach based on the Elo rating method for cardinal rank assignment, which enables the detection of winner and loser effects in uncontrolled group settings. Our results demonstrate (i) the presence of winner and loser effects, and (ii) that individual susceptibility to such effects may have a genetic basis. Taken together, our results show that both social self-organization dynamics and prior attributes can combine to influence hierarchy dynamics even when agonistic interactions are strongly influenced by differences in individual attributes. We hypothesize that, despite variation in individual attributes, winner and loser effects exist (i) because these effects could be particularly beneficial when fighting abilities in other group members change over time, and (ii) because the coevolution of prior attributes and winner and loser effects maintains a balance of both effects.
Climate change alters the structure of arctic marine food webs due to poleward shifts of boreal generalists
Authors: Kortsch Susanne , Primicerio Raul , Fossheim Maria , Dolgov Andrey V. , Aschan Michaela
Published: September 2015

Climate-driven poleward shifts, leading to changes in species composition and relative abundances, have been recently documented in the Arctic. Among the fastest moving species are boreal generalist fish which are expected to affect arctic marine food web structure and ecosystem functioning substantially. Here, we address structural changes at the food web level induced by poleward shifts via topological network analysis of highly resolved boreal and arctic food webs of the Barents Sea. We detected considerable differences in structural properties and link configuration between the boreal and the arctic food webs, the latter being more modular and less connected. We found that a main characteristic of the boreal fish moving poleward into the arctic region of the Barents Sea is high generalism, a property that increases connectance and reduces modularity in the arctic marine food web. Our results reveal that habitats form natural boundaries for food web modules, and that generalists play an important functional role in coupling pelagic and benthic modules. We posit that these habitat couplers have the potential to promote the transfer of energy and matter between habitats, but also the spread of pertubations, thereby changing arctic marine food web structure considerably with implications for ecosystem dynamics and functioning.
Incorporating anthropogenic effects into trophic ecology: predator–prey interactions in a human-dominated landscape
Authors: Dorresteijn Ine , Schultner Jannik , Nimmo Dale G. , Fischer Joern , Hanspach Jan , Kuemmerle Tobias , Kehoe Laura , Ritchie Euan G.
Published: September 2015

Apex predators perform important functions that regulate ecosystems worldwide. However, little is known about how ecosystem regulation by predators is influenced by human activities. In particular, how important are top-down effects of predators relative to direct and indirect human-mediated bottom-up and top-down processes? Combining data on species' occurrence from camera traps and hunting records, we aimed to quantify the relative effects of top-down and bottom-up processes in shaping predator and prey distributions in a human-dominated landscape in Transylvania, Romania. By global standards this system is diverse, including apex predators (brown bear and wolf), mesopredators (red fox) and large herbivores (roe and red deer). Humans and free-ranging dogs represent additional predators in the system. Using structural equation modelling, we found that apex predators suppress lower trophic levels, especially herbivores. However, direct and indirect top-down effects of humans affected the ecosystem more strongly, influencing species at all trophic levels. Our study highlights the need to explicitly embed humans and their influences within trophic cascade theory. This will greatly expand our understanding of species interactions in human-modified landscapes, which compose the majority of the Earth's terrestrial surface.
The ring of life hypothesis for eukaryote origins is supported by multiple kinds of data
Authors: McInerney James , Pisani Davide , O'Connell Mary J.
Published: September 2015

The literature is replete with manuscripts describing the origin of eukaryotic cells. Most of the models for eukaryogenesis are either autogenous (sometimes called slow-drip), or symbiogenic (sometimes called big-bang). In this article, we use large and diverse suites of ‘Omics' and other data to make the inference that autogeneous hypotheses are a very poor fit to the data and the origin of eukaryotic cells occurred in a single symbiosis.
New genes from non-coding sequence: the role of de novo protein-coding genes in eukaryotic evolutionary innovation
Authors: McLysaght Aoife , Guerzoni Daniele
Published: September 2015

The origin of novel protein-coding genes de novo was once considered so improbable as to be impossible. In less than a decade, and especially in the last five years, this view has been overturned by extensive evidence from diverse eukaryotic lineages. There is now evidence that this mechanism has contributed a significant number of genes to genomes of organisms as diverse asSaccharomyces,Drosophila,Plasmodium,Arabidopisisand human. From simple beginnings, these genes have in some instances acquired complex structure, regulated expression and important functional roles. New genes are often thought of as dispensable late additions; however, some recent de novo genes in human can play a role in disease. Rather than an extremely rare occurrence, it is now evident that there is a relatively constant trickle of proto-genes released into the testing ground of natural selection. It is currently unknown whether de novo genes arise primarily through an ‘RNA-first’ or ‘ORF-first’ pathway. Either way, evolutionary tinkering with this pool of genetic potential may have been a significant player in the origins of lineage-specific traits and adaptations.
Peritoneal dialysis exit-site leak complicated by peritoneal dialysis-related peritonitis due to Actinomyces neuii
Authors: El Kossi Mohsen M. , Darwish Sanaa Fadel , Agwuh Kenneth , Milupi Manyando
Published: September 2015

Introduction:

Actinomyces neuii is a rare cause of peritoneal dialysis-related peritonitis.

Case presentation:

A 66-year-old male had end-stage renal disease on peritoneal dialysis treatment for 30 months. He developed exit-site leak with infection. Diphtheroids were isolated and considered initially as skin commensals. Dialysis treatment was suspended and on reinstitution he developed peritoneal dialysis-related peritonitis. The organism isolated from the peritoneal dialysis fluid was A. neuii.

Conclusion:

This case was treated successfully with peritoneal dialysis catheter removal and oral amoxicillin.