bluuebunny/crossref_metadata_2025 huggingface dataset:
Central Nervous System-type Neuroepithelial Tumors and Tumor-like Proliferations Developing in the Gynecologic Tract and Pelvis
Authors: Murdock Tricia , Orr Brent , Allen Sariah , Ibrahim Junaid , Sharma Rajni , Ronnett Brigitte M. , Rodriguez Fausto J.
Published: August 2018

Central nervous system (CNS)-type tumors and tumor-like proliferations arising in the gynecologic tract and pelvis are rare. Clinicopathologic features of 23 cases are reported using the current WHO classification system for CNS tumors, with selected relevant immunohistochemical and molecular genetic analyses when possible. There were 12 embryonal tumors, including 7 medulloepitheliomas, 2 embryonal tumors (not otherwise specified), 1 embryonal tumor with multilayered rosettes, 1 embryonal tumor with features of nodular desmoplastic medulloblastoma, and 1 medulloblastoma with extensive nodularity, with primary sites including ovary (7), uterus/endometrium (3), and pelvis (2). Six ovarian tumors had associated germ cell tumors (3 immature teratomas [1 also with yolk sac tumor], 2 mature cystic teratomas, and 1 yolk sac tumor). These tumors typically had some expression of synaptophysin (10/10), GFAP (5/9), S100 (3/6), and NeuN (3/3) and were negative for C19MC amplicon by fluorescence in situ hybridization (0/5). There were 6 glial tumors, including 3 ependymomas (1 anaplastic), 1 oligodendroglioma, not otherwise specified, 1 pilocytic astrocytoma, and 1 atypical glial proliferation after therapy of a high-grade high-stage immature teratoma, with primary sites including ovary (4), fallopian tube (1), and pelvic sidewall (1). Four ovarian tumors had associated teratomas (2 immature and 2 mature). These tumors expressed GFAP (5/6), OLIG2 (2/3), and S100 (1/1), and the pilocytic astrocytoma was negative for BRAF (V600E) mutant protein. There were 4 neuronal or mixed glioneuronal tumors, including 3 neurocytomas and 1 malignant (high-grade) glioneuronal neoplasm, all primary ovarian and associated with teratomas (3 mature, 1 immature). These tumors expressed synaptophysin (4/4), GFAP (1/3), NeuN (1/2), and OLIG2 (1/2). Single-nucleotide polymorphism microarray analysis of the malignant glioneuronal neoplasm demonstrated a partial deletion at location (1)(p36.23p35.2) on chromosome 1p, and 2 regions of deletion at locations (19)(q11q13.12) and (19)(q13.41qter) on 19q. One neurocytoma had no 1p and 19q co-deletions. There was 1 meningioma in the pelvis. For 10 patients with embryonal tumors and follow-up, 5 were alive with no evidence of disease (mean/median: 60/52 mo), 4 were alive with recurrent disease (mean/median: 32/31 mo), and 1 died of disease (13 mo). For 5 patients with other tumor types and follow-up, all were alive without evidence of disease (mean/median: 33/30 mo). Diagnostic evaluation and classification per systems used for primary CNS tumors are recommended for the wide spectrum of CNS-type neuroepithelial tumors that can occur in the female genital tract and pelvis.
Presenting Characteristics Associated With Outcome in Children With Severe Traumatic Brain Injury: A Secondary Analysis From a Randomized, Controlled Trial of Therapeutic Hypothermia*
Authors: Rosario Bedda L. , Horvat Christopher M. , Wisniewski Stephen R. , Bell Michael J. , Panigrahy Ashok , Zuccoli Giulio , Narayanan Srikala , Balasubramani Goundappa K. , Beers Sue R. , Adelson P. David
Published: August 2018

Objectives:

To identify injury patterns and characteristics associated with severe traumatic brain injury course and outcome, within a well-characterized cohort, which may help guide new research and treatment initiatives.

Design:

A secondary analysis of a phase 3, randomized, controlled trial that compared therapeutic hypothermia versus normothermia following severe traumatic brain injury in children.

Setting:

Fifteen sites in the United States, Australia, and New Zealand.

Patients:

Children (< 18 yr old) with severe traumatic brain injury.

Measurements and Main Results:

Baseline, clinical, and CT characteristics of patients (n = 77) were examined for association with mortality and outcome, as measured by the Glasgow Outcome Scale—Extended Pediatric Revision 3 months after traumatic brain injury. Data are presented as odds ratios with 95% CIs. No demographic, clinical, or CT characteristic was associated with mortality in bivariate analysis. Characteristics associated with worse Glasgow Outcome Scale—Extended Pediatric Revision in bivariate analysis were two fixed pupils (14.17 [3.38–59.37]), abdominal Abbreviated Injury Severity score (2.03 [1.19–3.49]), and subarachnoid hemorrhage (3.36 [1.30–8.70]). Forward stepwise regression demonstrated that Abbreviated Injury Severity spine (3.48 [1.14–10.58]) and midline shift on CT (8.35 [1.05–66.59]) were significantly associated with mortality. Number of fixed pupils (one fixed pupil 3.47 [0.79–15.30]; two fixed pupils 13.61 [2.89–64.07]), hypoxia (5.22 [1.02–26.67]), and subarachnoid hemorrhage (3.01 [1.01–9.01]) were independently associated with worse Glasgow Outcome Scale—Extended Pediatric Revision following forward stepwise regression.

Conclusions:

Severe traumatic brain injury is a clinically heterogeneous disease that can be accompanied by a range of neurologic impairment and a variety of injury patterns at presentation. This secondary analysis of prospectively collected data identifies several characteristics associated with outcome among children with severe traumatic brain injury. Future, larger trials are needed to better characterize phenotypes within this population.
Elevated HIV Prevalence and Correlates of PrEP Use Among a Community Sample of Black Men Who Have Sex With Men
Authors: Eaton Lisa A. , Matthews Derrick D. , Bukowski Leigh A. , Friedman M. Ruvel , Chandler Cristian J. , Whitfield Darren L. , Sang Jordan M. , Stall Ron D. ,   The POWER Study Team
Published: August 2018

Background:

The HIV epidemic among black men who have sex with men (BMSM) demands urgent public health attention. Pre-exposure prophylaxis (PrEP) is a highly efficacious option for preventing HIV, but characteristics of PrEP use among community samples of BMSM are not well-understood.

Methods:

A serial cross-sectional survey assessment (N = 4184 BMSM reporting HIV-negative/unsure status) and HIV testing were conducted at Black Gay Pride events in 6 US cities in 2014, 2015, 2016, and 2017.

Results:

HIV prevalence was higher among BMSM self-reporting current PrEP use (1 of 3 participants) than BMSM not self-reporting current PrEP use (1 of 5 participants) [32.3%, N = 103/319 vs. 20.0%, N = 639/3,193, adjusted odds ratio (aOR) = 1.68, 95% confidence interval (CI): 1.31 to 2.15]. BMSM reporting current PrEP use (N = 380) were more likely to report having a greater number of male sex partners (aOR = 1.02, 95% CI: 1.01 to 1.03), a sexually transmitted infection diagnosis (aOR = 2.44, 95% CI: 1.88 to 3.16), and stimulant drug use (aOR = 2.05, 95% CI, 1.21 to 3.47) when compared with BMSM not reporting current PrEP use (N = 3804). PrEP use increased from 4.7% (2014) to 15.5% (2017) (aOR = 1.19, 95% CI: 1.13 to 1.25). Among PrEP users, inability to afford health care coverage was associated with testing HIV-positive (aOR = 2.10, 95% CI: 1.24 to 3.56).

Conclusions:

The high prevalence of HIV infection among BMSM reporting PrEP use is concerning. It does not, however, challenge the efficacy of PrEP itself but rather the uptake of the surrounding preventative package including behavioral risk reduction support, sexually transmitted infection treatment, and medication adherence counseling. Further research to understand barriers to fully effective PrEP is needed to guide operational and behavioral interventions that close the gap on incident infection.
Pulmonary Manifestations of Common Variable Immunodeficiency
Authors: Bang Tami J. , Richards John Caleb , Olson Amy L. , Groshong Steve D. , Gelfand Erwin W. , Lynch David A.
Published: August 2018

Common variable immunodeficiency (CVID) is associated with significant chronic lung disease. The purpose of this paper was to describe the clinical, radiologic, and pathologic findings of CVID-associated lung diseases. These include airways’ disease, interstitial lung disease, lymphoma, and mucosa-associated lymphoid tissue lymphoma. In addition, a genetic syndrome termed Kabuki syndrome results in CVID-like immune abnormalities. These patients may also present with CVID-associated lung disease. Awareness and precise identification of CVID-associated lung disease may allow for better assessment of prognosis and direction of therapy.
Partial Deletion of Tie2 Affects Microvascular Endothelial Responses to Critical Illness in A Vascular Bed and Organ-Specific Way
Authors: Jongman Rianne M. , Zwiers Peter J. , van de Sluis Bart , van der Laan Marleen , Moser Jill , Zijlstra Jan G. , Dekker Daphne , Huijkman Nicolette , Moorlag Henk E. , Popa Eliane R. , Molema Grietje , van Meurs Matijs
Published: August 2018

Tyrosine kinase receptor (Tie2) is mainly expressed by endothelial cells. In animal models mimicking critical illness, Tie2 levels in organs are temporarily reduced. Functional consequences of these reduced Tie2 levels on microvascular endothelial behavior are unknown. We investigated the effect of partial deletion of Tie2 on the inflammatory status of endothelial cells in different organs. Newly generated heterozygous Tie2 knockout mice (exon 9 deletion, ΔE9/Tie2+/−) exhibiting 50% reduction in Tie2 mRNA and protein, and wild-type littermate controls (Tie2+/+), were subjected to hemorrhagic shock and resuscitation (HS + R), or challenged with i.p. lipopolysaccharide (LPS). Kidney, liver, lung, heart, brain, and intestine were analyzed for mRNA levels of adhesion molecules E-selectin, vascular cell adhesion molecule 1 (VCAM-1), and intercellular cell adhesion molecule 1 (ICAM-1), and CD45. Exposure to HS + R did not result in different expression responses of these molecules between organs from Tie2+/− or Tie2+/+ mice and sham-operated mice. In contrast, the LPS-induced mRNA expression levels of E-selectin, VCAM-1, and ICAM-1, and CD45 in organs were attenuated in Tie2+/− mice when compared with Tie2+/+ mice in kidney and liver, but not in the other organs studied. Furthermore, reduced expression of E-selectin and VCAM-1 protein, and reduced influx of CD45+ cells upon LPS exposure, was visible in a microvascular bed-specific pattern in kidney and liver of Tie2+/− mice compared with controls. In contrast to the hypothesis that a disbalance in the Ang/Tie2 system leads to increased microvascular inflammation, heterozygous deletion of Tie2 is associated with an organ-restricted, microvascular bed-specific attenuation of endothelial inflammatory response to LPS.
Does Surgical Margin Impact Recurrence in Noninvasive Intraductal Papillary Mucinous Neoplasms?
Authors: Dhar Vikrom K. , Merchant Nipun B. , Patel Sameer H. , Edwards Michael J. , Wima Koffi , Imbus Joseph , Abbott Daniel E. , Weber Sharon M. , Louie Raphael , Kim Hong J. , Martin Robert C. G. , Scoggins Charles R. , Bentrem David J. , LeCompte Michael T. , Idrees Kamran , Lopez-Aguiar Alexandra G. , Maithel Shishir K. , Kooby David A. , Franco Daniel A. , Yakoub Danny , Ahmad Syed A.
Published: August 2018

Objective:

The relevance of margin positivity on recurrence after resection of intraductal papillary mucinous neoplasms (IPMNs) is poorly defined and represents one reason controversy remains regarding optimal surveillance recommendations.

Methods:

Patients undergoing surgery for noninvasive IPMN at 8 academic medical centers from the Central Pancreas Consortium were analyzed. A positive margin was defined as presence of IPMN or pancreatic intraepithelial neoplasia.

Results:

Five hundred two patients underwent surgery for IPMN; 330 (66%) did not have invasive cancer on final pathology and form the study cohort. Of these, 20% harbored high grade dysplasia. A positive margin was found in 20% of cases and was associated with multifocal disease (P = 0.02). The majority of positive margins were associated with low grade dysplasia. At a median follow-up of 36 months, 34 (10.3%) patients recurred, with 6.7% developing recurrent cystic disease and 3.6% developing invasive cancer. On multivariate analysis, margin positivity was not associated with recurrence of either IPMN or invasive cancer (P > 0.05). No association between margin status and development of recurrence at the margin was found. Only 6% of recurrences developed at the resection margin and median time to recurrence was 22 months. Of note, 18% of recurrences occurred > 5 years following surgery.

Conclusion:

Margin positivity after resection for noninvasive IPMNs is primarily due to low grade dysplasia and is not associated with developing recurrence in the remnant pancreas or at the resection margin. Long-term surveillance is required for all patients, as a significant number of recurrences developed over 5 years after the index operation.
Application of Barbed Sutures in Laparoscopic Common Bile Duct Exploration: A Retrospective Analysis
Authors: Liu Xiangdong , Luo De , Chen Hong , Liu Jiang , Peng Fangyi , Fang Cheng , Li Bo , Su Song
Published: August 2018

Common bile duct (CBD) suturing is a difficult procedure in laparoscopic CBD exploration. We sought to develop a simpler CBD suture technique using running barbed sutures. We retrospectively compared 2 suture techniques for CBD closure after T-tube placement. The barbed group comprised of 46 patients who underwent CBD closure using running barbed sutures, whereas the standard group comprised of 39 patients who received interrupted sutures. Mean CBD suturing time (6.2±0.9 vs. 12.2±1.1 min; P<0.001), total operating time (79.7±9.4 vs. 90.8±12.4 min; P<0.001), and hospital stay (6.1±1.8 vs. 7.0±1.7 d; P=0.024) were significantly shorter and less patients experienced leakage after T-tube flushing (P=0.041) with the barbed suture technique. There were 2 cases of postoperative bile leakage in the standard group, with no statistical significance. The running barbed suture technique is safe and effective for CBD closure, which can decrease operating time and risk of complications.
Reproducibility of academic preclinical translational research: lessons from the development of Hedgehog pathway inhibitors to treat cancer
Authors: Curran Tom
Published: August 2018

Academic translational research is growing at a great pace at a time in which questions have been raised about the reproducibility of preclinical findings. The development of Hedgehog (HH) pathway inhibitors for the treatment of cancer over the past two decades offers a case study for understanding the root causes of failure to predict clinical outcomes arising from academic preclinical translational research. Although such inhibitors were once hoped to be efficacious in up to 25% of human cancer, clinical studies showed responses only in basal cell carcinoma and the HH subtype of medulloblastoma. Close examination of the published studies reveals limitations in the models used, lack of quantitative standards, utilization of high drug concentrations associated with non-specific toxicities and improper use of cell line and mouse models. In part, these issues arise from scientific complexity, for example, the failure of tumour cell lines to maintain HH pathway activity
in vitro
, but a greater contributing factor appears to be the influence of unconscious bias. There was a strong expectation that HH pathway inhibitors would make a profound impact on human cancer and experiments were designed with this assumption in mind.
Polarized Ukraine 2014: opinion and territorial split demonstrated with the bounded confidence XY model, parametrized by Twitter data
Authors: Romenskyy Maksym , Spaiser Viktoria , Ihle Thomas , Lobaskin Vladimir
Published: August 2018

Multiple countries have recently experienced extreme political polarization, which, in some cases, led to escalation of hate crime, violence and political instability. Besides the much discussed presidential elections in the USA and France, Britain's Brexit vote and Turkish constitutional referendum showed signs of extreme polarization. Among the countries affected, Ukraine faced some of the gravest consequences. In an attempt to understand the mechanisms of these phenomena, we here combine social media analysis with agent-based modelling of opinion dynamics, targeting Ukraine's crisis of 2014. We use Twitter data to quantify changes in the opinion divide and parametrize an extended bounded confidence XY model, which provides a spatio-temporal description of the polarization dynamics. We demonstrate that the level of emotional intensity is a major driving force for polarization that can lead to a spontaneous onset of collective behaviour at a certain degree of homophily and conformity. We find that the critical level of emotional intensity corresponds to a polarization transition, marked by a sudden increase in the degree of involvement and in the opinion bimodality.
Perceptions of newsworthiness are contaminated by a political usefulness bias
Authors: Pashler Harold , Heriot Gail
Published: August 2018

Are people's perceptions of the newsworthiness of events biased by a tendency to rate as more important any news story that seems likely to lead others to share their own political attitudes? To assess this, we created six pairs of hypothetical news stories, each describing an event that seemed likely to encourage people to adopt attitudes on the opposite side of a particular controversial issue (e.g. affirmative action and gay marriage). In total, 569 subjects were asked to evaluate the importance of these stories ‘to the readership of a general-circulation newspaper’, disregarding how interesting they happened to find the event. Subjects later indicated their own personal attitudes to the underlying political issues. Predicted crossover interactions were confirmed for all six issues. All the interactions took the form of subjects rating stories offering ‘ammunition’ for their own side of the controversial issue as possessing greater intrinsic news importance.
A method for deducing neck mobility in plesiosaurs, using the exceptionally preserved
Nichollssaura borealis
Authors: Nagesan Ramon S. , Henderson Donald M. , Anderson Jason S.
Published: August 2018

The elongate-necked aquatic plesiosaurs existed for 135 Myr during the Mesozoic. The function of this elongate neck is a point of debate. Using computed tomography and three-dimensional (3D) modelling, the range of motion (ROM) of the plesiosaur
Nichollssaura borealis
neck was assessed. To quantify the ROM, the intervertebral mobility was measured along the cervical vertebral column. This was done by manipulating the 3D models in the lateral and dorsoventral directions during two trials. The first assessed the mean intervertebral ROM between pairs of cervical vertebrae along the entire column, and the second assessed ROM with reduced intervertebral spaces. The results suggest that there may be preference for lateral neck movements in
N. borealis
, which could correspond to an ecological function related to prey capture. This study demonstrates that 3D modelling is an effective tool for assessing function morphology for structures where no good modern analogue exists.
Two types of social grooming methods depending on the trade-off between the number and strength of social relationships
Authors: Takano Masanori
Published: August 2018

Humans use various social bonding methods known as social grooming, e.g. face to face communication, greetings, phone and social networking sites (SNS). SNS have drastically decreased time and distance constraints of social grooming. In this paper, I show that two types of social grooming (elaborate social grooming and lightweight social grooming) were discovered in a model constructed by 13 communication datasets including face to face, SNS and Chacma baboons. The separation of social grooming methods is caused by a difference in the trade-off between the number and strength of social relationships. The trade-off of elaborate social grooming is weaker than the trade-off of lightweight social grooming. On the other hand, the time and effort of elaborate methods are higher than those of lightweight methods. Additionally, my model connects social grooming behaviour and social relationship forms with these trade-offs. By analysing the model, I show that individuals tend to use elaborate social grooming to reinforce a few close relationships (e.g. face to face and Chacma baboons). By contrast, people tend to use lightweight social grooming to maintain many weak relationships (e.g. SNS). Humans with lightweight methods who live in significantly complex societies use various types of social grooming to effectively construct social relationships.
How wide is the cone of direct gaze?
Authors: Balsdon Tarryn , Clifford Colin W. G.
Published: August 2018

The cone of direct gaze refers to the range of gaze deviations an observer accepts as looking directly at them. Previous experiments have calculated the width of the cone of direct gaze using the gaze deviations actually presented to the observer, however, there is considerable evidence that observers actually perceive gaze to be systematically more deviated than actually presented. Here, we examine the width of the cone of direct gaze in units of perceived gaze deviation. In doing so, we are able to disambiguate differences in width both within and between observers that are due to differences in their perception of gaze and due to differences in what observers consider to be looking at them. We suggest that this line of inquiry can offer further insight into the perception of gaze direction, and how this perception may differ in clinical populations.
Soluble hexamethyl-substituted subphthalocyanine as a dopant-free hole transport material for planar perovskite solar cells
Authors: Wang Feng , Liu Xiaoyuan , Rezaee Ehsan , Shan Haiquan , Zhou Yuxia , Xu Zong-Xiang
Published: August 2018

Boron subphthalocyanine (SubPc) has special physical and chemical properties, originating from its non-centrosymmetric, near-planar taper structure and large conjugated system; it can act as an alternative to the small molecule hole-transporting material 2,2′,7,7′-tetrakis-(
N
,
N
-di-
p
-methoxyphenylamine)-9,9′-spirobifluorene in perovskite solar cells (PSCs). To achieve a higher solubility in common organic solvents and a more suitable highest occupied molecular orbital energy level that aligns with the valence band of the perovskite material, a SubPc molecule with a hexamethyl substitution at its peripheral position (Me
6
-SubPc) was successfully designed and synthesized in a one-step method. Completely solution processed PSCs were fabricated with only a small hysteresis, a power conversion efficiency of 6.96% and
V
oc
of 0.986 V.
The auxiliary region method: a hybrid method for coupling PDE- and Brownian-based dynamics for reaction–diffusion systems
Authors: Smith Cameron A. , Yates Christian A.
Published: August 2018

Reaction–diffusion systems are used to represent many biological and physical phenomena. They model the random motion of particles (diffusion) and interactions between them (reactions). Such systems can be modelled at multiple scales with varying degrees of accuracy and computational efficiency. When representing genuinely multiscale phenomena, fine-scale models can be prohibitively expensive, whereas coarser models, although cheaper, often lack sufficient detail to accurately represent the phenomenon at hand. Spatial hybrid methods couple two or more of these representations in order to improve efficiency without compromising accuracy. In this paper, we present a novel spatial hybrid method, which we call the auxiliary region method (ARM), which couples PDE- and Brownian-based representations of reaction–diffusion systems. Numerical PDE solutions on one side of an interface are coupled to Brownian-based dynamics on the other side using compartment-based ‘auxiliary regions’. We demonstrate that the hybrid method is able to simulate reaction–diffusion dynamics for a number of different test problems with high accuracy. Furthermore, we undertake error analysis on the ARM which demonstrates that it is robust to changes in the free parameters in the model, where previous coupling algorithms are not. In particular, we envisage that the method will be applicable for a wide range of spatial multi-scales problems including filopodial dynamics, intracellular signalling, embryogenesis and travelling wave phenomena.
Dispersive shock waves governed by the Whitham equation and their stability
Authors: An X. , Marchant T. R. , Smyth N. F.
Published: August 2018

Dispersive shock waves (DSWs), also termed undular bores in fluid mechanics, governed by the non-local Whitham equation are studied in order to investigate short wavelength effects that lead to peaked and cusped waves within the DSW. This is done by combining the weak nonlinearity of the Korteweg–de Vries equation with full linear dispersion relations. The dispersion relations considered are those for surface gravity waves, the intermediate long wave equation and a model dispersion relation introduced by Whitham to investigate the 120° peaked Stokes wave of highest amplitude. A dispersive shock fitting method is used to find the leading (solitary wave) and trailing (linear wave) edges of the DSW. This method is found to produce results in excellent agreement with numerical solutions up until the lead solitary wave of the DSW reaches its highest amplitude. Numerical solutions show that the DSWs for the water wave and Whitham peaking kernels become modulationally unstable and evolve into multi-phase wavetrains after a critical amplitude which is just below the DSW of maximum amplitude.
From arteries to boreholes: transient response of a poroelastic cylinder to fluid injection
Authors: Auton L. C. , MacMinn C. W.
Published: August 2018

The radially outward flow of fluid through a porous medium occurs in many practical problems, from transport across vascular walls to the pressurization of boreholes in the subsurface. When the driving pressure is non-negligible relative to the stiffness of the solid structure, the poromechanical coupling between the fluid and the solid can control both the steady state and the transient mechanics of the system. Very large pressures or very soft materials lead to large deformations of the solid skeleton, which introduce kinematic and constitutive nonlinearity that can have a non-trivial impact on these mechanics. Here, we study the transient response of a poroelastic cylinder to sudden fluid injection. We consider the impacts of kinematic and constitutive nonlinearity, both separately and in combination, and we highlight the central role of driving method in the evolution of the response. We show that the various facets of nonlinearity may either accelerate or decelerate the transient response relative to linear poroelasticity, depending on the boundary conditions and the initial geometry, and that an imposed fluid pressure leads to a much faster response than an imposed fluid flux.
Adaptive evolution of distinct prey-specific toxin genes in rear-fanged snake venom
Authors: Modahl Cassandra M. , Mrinalini  , Frietze Seth , Mackessy Stephen P.
Published: August 2018

Venom proteins evolve rapidly, and as a trophic adaptation are excellent models for predator–prey evolutionary studies. The key to a deeper understanding of venom evolution is an integrated approach, combining prey assays with analysis of venom gene expression and venom phenotype. Here, we use such an approach to study venom evolution in the Amazon puffing snake,
Spilotes sulphureus
, a generalist feeder. We identify two novel three-finger toxins: sulditoxin and sulmotoxin 1. These new toxins are not only two of the most abundant venom proteins, but are also functionally intriguing, displaying distinct prey-specific toxicities. Sulditoxin is highly toxic towards lizard prey, but is non-toxic towards mammalian prey, even at greater than 22-fold higher dosage. By contrast, sulmotoxin 1 exhibits the reverse trend. Furthermore, evolutionary analysis and structural modelling show highest sequence variability in the central loop of these proteins, probably driving taxon-specific toxicity. This is, to our knowledge, the first case in which a bimodal and contrasting pattern of toxicity has been shown for proteins in the venom of a single snake in relation to diet. Our study is an example of how toxin gene neofunctionalization can result in a venom system dominated by one protein superfamily and still exhibit flexibility in prey capture efficacy.
Borrelia afzeliialters reproductive success in a rodent host
Authors: Cayol Claire , Giermek Anna , Gomez-Chamorro Andrea , Hytönen Jukka , Kallio Eva Riikka , Mappes Tapio , Salo Jemiina , Voordouw Maarten Jeroen , Koskela Esa
Published: August 2018

The impact of a pathogen on the fitness and behaviour of its natural host depends upon the host–parasite relationship in a given set of environmental conditions. Here, we experimentally investigated the effects ofBorrelia afzelii,one of the aetiological agents of Lyme disease in humans, on the fitness of its natural rodent host, the bank vole (Myodes glareolus), in semi-natural conditions with two contrasting host population densities. Our results show thatB. afzeliican modify the reproductive success and spacing behaviour of its rodent host, whereas host survival was not affected. Infection impaired the breeding probability of large bank voles. Reproduction was hastened in infected females without alteration of the offspring size at birth. At low density, infected males produced fewer offspring, fertilized fewer females and had lower mobility than uninfected individuals. Meanwhile, the infection did not affect the proportion of offspring produced or the proportion of mating partner in female bank voles. Our study is the first to show thatB. afzeliiinfection alters the reproductive success of the natural host. The effects observed could reflect the sickness behaviour due to the infection or they could be a consequence of a manipulation of the host behaviour by the bacteria.
Latitudinal pattern of flowering synchrony in an invasive wind-pollinated plant
Authors: Qiu Shiyun , Xu Xiao , Liu Shuangshuang , Liu Wenwen , Liu Jing , Nie Ming , Shi Fuchen , Zhang Yihui , Weiner Jacob , Li Bo
Published: August 2018

Flowering synchrony can play an important role in plants' reproductive success, which is essential for the successful establishment and spread of invasive plants. Although flowering synchrony has been found to be closely related to climatic factors, the effects of variation in such factors along latitudinal gradient on flowering synchrony and the role of flowering synchrony in the reproductive success of invading populations remain largely unexplored. In a 2-year field study, we examined the latitudinal variation of flowering phenology, especially flowering synchrony, in an invasive plant,
Spartina alterniflora
, along coastal China, and its relationship with population seed set across three climatic zones. We found that first flowering date was delayed, and flowering synchrony increased with increasing latitude. Flowering synchrony was negatively related to temperature during flowering season but not to soil properties or precipitation, suggesting that climate has shaped the latitudinal pattern of flowering synchrony. Moreover, a positive correlation between flowering synchrony and seed set across latitudes indicates the possible role of flowering synchrony in the latitudinal pattern of sexual reproduction in
S. alterniflora
. These results suggest that, in addition to the effects of climate on the growth of invasive species, climatic factors can play an important role in the invasion success of alien plants by regulating the flowering synchrony and thus the reproductive success of invasive plants.
Differential allocation of parental investment and the trade-off between size and number of offspring
Authors: Ratikainen Irja Ida , Haaland Thomas Ray , Wright Jonathan
Published: August 2018

When parents decide how much to invest in current versus future offspring and how many offspring to divide their current investments between, the optimal decision can be affected by the quality of their partner. This differential allocation (DA) is highly dependent on exactly how partner quality affects reproductive costs and offspring benefits. We present a stochastic dynamic model of DA in which females care for a series of clutches when mated with males of different quality. In each reproductive event, females choose the size and number of offspring. We find that if partner quality affects reproductive costs, then DA in total reproductive investment occurs only via changes in the number of offspring. DA in the optimal size of the offspring occurs only if partner quality affects the offspring benefit function. This is mostly in the form of greater female investment per offspring as male quality decreases. Simultaneously, we find that adaptive DA increases the number of offspring, and thus the amount of total investment, as male quality increases. Only certain model scenarios produce the positive DA in offspring size seen in empirical studies, providing a predictive framework for DA and how partner quality affects reproductive costs and offspring benefits.
Howling from the past: historical phylogeography and diversity losses in European grey wolves
Authors: Dufresnes Christophe , Miquel Christian , Remollino Nadège , Biollaz François , Salamin Nicolas , Taberlet Pierre , Fumagalli Luca
Published: August 2018

Genetic bottlenecks resulting from human-induced population declines make alarming symbols for the irreversible loss of our natural legacy worldwide. The grey wolf (Canis lupus) is an iconic example of extreme declines driven by anthropogenic factors. Here, we assessed the genetic signatures of 150 years of wolf persecution throughout the Western Palaearctic by high-throughput mitochondrial DNA sequencing of historical specimens in an unprecedented spatio-temporal framework. Despite Late Pleistocene bottlenecks, we show that historical genetic variation had remained high throughout Europe until the last several hundred years. In Western Europe, where wolves nearly got fully exterminated, diversity dramatically collapsed at the turn of the twentieth century and recolonization from few homogeneous relict populations induced drastic shifts of genetic composition. By contrast, little genetic displacement and steady levels of diversity were maintained in Eastern European regions, where human persecution had lesser effects on wolf demography. By comparing prehistoric, historic and modern patterns of genetic diversity, our study hence traces the timeframe and the active human role in the decline of the grey wolf, an emblematic yet controversial animal which symbolizes the complex relationship between human societies and nature conservation.
Agonistic character displacement of genetically based male colour patterns across darters
Authors: Moran Rachel L. , Fuller Rebecca C.
Published: August 2018

Agonistic character displacement (ACD) occurs when selection to avoid maladaptive interspecific aggression leads to the evolution of agonistic signals and/or associated behavioural biases in sympatry. Here, we test for a pattern consistent with ACD in male colour pattern in darters (Percidae:Etheostoma). Male colour pattern has been shown to function in male–male competition rather than female mating preferences in several darter species. Additionally, males bias their aggression towards conspecific over heterospecific males in sympatry but not in allopatry, consistent with divergent ACD in male behavioural biases. We use a common garden approach to show that differences in male colour pattern among four closely related darter species are genetically based. Additionally, we demonstrate that some aspects of male colour pattern exhibit enhanced differences in sympatric compared to allopatric populations of two darter species, consistent with ACD. However, other male colour traits are more similar between species in sympatry compared with allopatry, indicating that not all signal components are under strong divergent selection in sympatry. This study provides evidence that interspecific male–male aggressive interactions alone can promote elaborate male signal evolution both between and within species. We discuss the implications this has for male-driven ACD and cascade ACD.
Do larger individuals cope with resource fluctuations better? An artificial selection approach
Authors: Malerba Martino E. , Palacios Maria M. , Marshall Dustin J.
Published: August 2018

Size determines the rate at which organisms acquire and use resources but it is unclear what size should be favoured under unpredictable resource regimes. Some theories claim smaller organisms can grow faster following a resource pulse, whereas others argue larger species can accumulate more resources and maintain growth for longer periods between resource pulses. Testing these theories has relied on interspecific comparisons, which tend to confound body size with other life-history traits. As a more direct approach, we used 280 generations of artificial selection to evolve a 10-fold difference in mean body size between small- and large-selected phytoplankton lineages ofDunaliella tertiolecta, while controlling for biotic and abiotic variables. We then quantified how body size affected the ability of this species to grow at nutrient-replete conditions and following periods of nitrogen or phosphorous deprivation. Overall, smaller cells showed slower growth, lower storage capacity and poorer recovery from phosphorous depletion, as predicted by the ‘fasting endurance hypothesis'. However, recovery from nitrogen limitation was independent of size—a finding unanticipated by current theories. Phytoplankton species are responsible for much of the global carbon fixation and projected trends of cell size decline could reduce primary productivity by lowering the ability of a cell to store resources.
Behavioural evidence for polychromatic ultraviolet sensitivity in mantis shrimp
Authors: Bok Michael J. , Roberts Nicholas W. , Cronin Thomas W.
Published: August 2018

Stomatopod crustaceans are renowned for their elaborate visual systems. Their eyes contain a plethora of photoreceptors specialized for chromatic and polarization detection, including several that are sensitive to varying wavelength ranges and angles of polarization within the ultraviolet (UV) range (less than 400 nm). Behavioural experiments have previously suggested that UV photoreception plays a role in stomatopod communication, but these experiments have only manipulated the entire UV range. Here, using a behavioural approach, we examine UV vision in the stomatopod
Haptosquilla trispinosa
. Using binary trained choice assays as well as innate burrow-choice experiments, we assessed the ability of
H. trispinosa
to detect and respond to narrow-band LED stimuli peaking near 314 nm (UVB) versus 379 nm (UVA) in wavelength. We find that
H. trispinosa
can discriminate these stimuli and appears to display an aversive reaction to UVB light, suggesting segregated behavioural responses to stimuli within the UV range. Furthermore, we find that
H. trispinosa
can discriminate stimuli peaking near 379 nm versus 351 nm in wavelength, suggesting that their wavelength discrimination in the UV is comparable to their performance in the human-visible range.
Microbe Profile: Aspergillus fumigatus: a saprotrophic and opportunistic fungal pathogen
Authors: Fang Wenxia , Latgé Jean-Paul
Published: August 2018

Aspergillus fumigatus is a saprotrophic fungus that continuously disseminates spores (conidia) into the environment. It is also the most common and opportunistic aerial fungal pathogen, causing allergic and chronic lung pathologies including the fatal invasive aspergillosis in immunocompromised patients. The pathobiology of aspergillosis is complex and depends on the competence of the host immune system. Moreover, A. fumigatus has become a model to study unique features of fungi. This includes the fungal cell wall, which not only acts as a rigid skeleton for protection against hostile environments but also plays significant roles during infection by manipulating the host immune response.
Astrocytes integrate local sensory and brain-wide neuromodulatory signals
Authors: Slezak Michal , Kandler Steffen , Van Veldhoven Paul P. , Bonin Vincent , Holt Matthew G.
Published: August 2018

Astrocytes play multiple functions in the central nervous system, from control of blood flow through to modulation of synaptic activity. Transient increases in intracellular Ca2+ are thought to control these activities. The prevailing concept is that these Ca2+ transients are triggered by distinct pathways, with little mechanistic and functional overlap. Here we demonstrate that astrocytes in visual cortex of mice encode local visual signals in conjunction with arousal state, functioning as multi-modal integrators. Such activity adds an additional layer of complexity to astrocyte function and may enable astrocytes to specifically and subtly regulate local network activity and plasticity.
Synthetic metabolic pathways for photobiological conversion of CO2 into hydrocarbon fuel
Authors: Yunus Ian Sofian , Wichmann Julian , Wördenweber Robin , Lauersen Kyle J. , Kruse Olaf , Jones Patrik R.
Published: August 2018

Liquid fuels sourced from fossil sources are the dominant energy form for mobile transport today. The consumption of fossil fuels is still increasing, resulting in a continued search for more sustainable methods to renew our supply of liquid fuel. Photosynthetic microorganisms naturally accumulate hydrocarbons that could serve as a replacement for fossil fuel, however productivities remain low. We report successful introduction of five synthetic metabolic pathways in two green cell factories, prokaryotic cyanobacteria and eukaryotic algae. Heterologous thioesterase expression enabled high-yield conversion of native acyl-ACP into free fatty acids (FFA) in Synechocystis sp. PCC 6803 but not in Chlamydomonas reinhardtii where the polar lipid fraction instead was enhanced. Despite no increase in measurable FFA in Chlamydomonas, genetic recoding and over-production of the native fatty acid photodecarboxylase (FAP) resulted in increased accumulation of 7-heptadecene. Implementation of a carboxylic acid reductase (CAR) and aldehyde deformylating oxygenase (ADO) dependent synthetic pathway in Synechocystis resulted in the accumulation of fatty alcohols and a decrease in the native saturated alkanes. In contrast, the replacement of CAR and ADO with Pseudomonas mendocina UndB (so named as it is responsible for 1-undecene biosynthesis in Pseudomonas) or Chlorella variabilis FAP resulted in high-yield conversion of thioesterase-liberated FFAs into corresponding alkenes and alkanes, respectively. At best, the engineering resulted in an increase in hydrocarbon accumulation of 8- (from 1 to 8.5 mg/g dell dry weight) and 19-fold (from 4 to 77 mg/g cell dry weight) for Chlamydomonas and Synechocystis, respectively. In conclusion, reconstitution of the eukaryotic algae pathway in the prokaryotic cyanobacteria host generated the most effective system, highlighting opportunities for mix-and-match synthetic metabolism. These studies describe functioning synthetic metabolic pathways for hydrocarbon fuel synthesis in photosynthetic microorganisms for the first time, moving us closer to the commercial implementation of photobiocatalytic systems that directly convert CO2 into infrastructure-compatible fuels.

Highlights

Synthetic metabolic pathways for hydrocarbon fuels were engineered in algae

Free fatty acids were effectively converted into alkenes and alkanes

Transfer of algal pathway into cyanobacteria was the most effective

Alkane yield was enhanced 19-fold in Synechocystis spp. PCC 6803

Alkene yield was enhanced 8-fold in Chlamydomonas reinhardtii
An Ishihara-style test of animal colour vision
Authors: Cheney Karen L. , Green Naomi F. , Vibert Alexander P. , Vorobyev Misha , Marshall N. Justin , Osorio Daniel C. , Endler John A.
Published: August 2018

Colour vision mediates ecologically relevant tasks for many animals, such as mate choice, foraging and predator avoidance. However, our understanding of animal colour perception is largely derived from human psychophysics, even though animal visual systems differ from our own. Behavioural tests of non-human animals are required to understand how colour signals are perceived by them.

Here we introduce a novel test of colour vision in animals inspired by the Ishihara colour charts, which are widely used to identify human colour deficiencies. These charts consist of dots that vary in colour, brightness and size, and are designed so that a numeral or letter is distinguishable from distractor dots for humans with normal colour vision. In our method, distractor dots have a fixed chromaticity (hue and saturation) but vary in luminance. Animals can be trained to find single target dots that differ from distractor dots in chromaticity. We provide Matlab code for creating these stimuli, which can be modified for use with different animals.

We demonstrate the success of this method with triggerfìsh, Rhinecanthus aculeatus, and highlight behavioural parameters that can be measured, including success of finding the target dot, time to detect dot and error rate. Triggerfìsh quickly learnt to select target dots that differed from distractors dots regardless of the particular hue or saturation, and proved to use acute colour vision. We measured discrimination thresholds by testing the detection of target colours that were of increasing colour distances (ΔS) from distractor dots in different directions of colour space. At least for some colours, thresholds indicated better discrimination than expected from the Receptor Noise Limited (RNL) model assuming 5% Weber fraction for the long-wavelength cone.

This methodology seems to be highly effective because it resembles natural foraging behavior for the triggerfìsh and may well be adaptable to a range of other animals, including mammals, birds, bees and freshwater fish. Other questions may be addressed using this methodology, including luminance thresholds, sensory bias, effects of sensory noise in detection tasks, colour categorization and saliency.