bluuebunny/crossref_metadata_2025 huggingface dataset:
Yeast Aim21/Tda2 both regulates free actin by reducing barbed end assembly and forms a complex with Cap1/Cap2 to balance actin assembly between patches and cables
Authors: Shin Myungjoo , van Leeuwen Jolanda , Boone Charles , Bretscher Anthony
Published: February 2018

How cells balance the incorporation of actin into diverse structures is poorly understood. In budding yeast, a single actin monomer pool is used to build both actin cables involved in polarized growth and actin cortical patches involved in endocytosis. Here we report how Aim21/Tda2 is recruited to the cortical region of actin patches, where it negatively regulates actin assembly to elevate the available actin monomer pool. Aim21 has four polyproline regions and is recruited by two SH3-containing patch proteins, Bbc1 and Abp1. The C-terminal region, which is required for its function, binds Tda2. Cell biological and biochemical data reveal that Aim21/Tda2 is a negative regulator of barbed end filamentous actin (F-actin) assembly, and this activity is necessary for efficient endocytosis and plays a pivotal role in balancing the distribution of actin between cables and patches. Aim21/Tda2 also forms a complex with the F-actin barbed end capping protein Cap1/Cap2, revealing an interplay between regulators and showing the complexity of regulation of barbed end assembly.
Membrane detachment is not essential for COG complex function
Authors: Climer Leslie K. , Pokrovskaya Irina D. , Blackburn Jessica B. , Lupashin Vladimir V.
Published: February 2018

The conserved oligomeric Golgi (COG) complex is a vesicle tether of the “complexes associated with tethering containing helical rods” family, which functions on the cytoplasmic side of Golgi. It is currently unknown whether COG function, or function of any multisubunit vesicular tether, depends on cycling between the membrane and cytosol. Therefore, we permanently anchored key subunits of COG subcomplexes (COG4, COG7, and COG8) to Golgi membranes using transmembrane protein TMEM115 (TMEM-COG). All TMEM-COG subunits tested were Golgi localized, integrated into the COG complex, and stabilized membrane association of endogenous subunits. Interestingly, TMEM-COG4 and TMEM-COG7 equally rescued COG function in organization of Golgi markers, glycosylation, and abundance of COG-sensitive proteins. In contrast, TMEM-COG8 was not as effective, indicating that N-terminal attachment of COG8 interfered with overall COG structure and function, and none of the TMEM-COG subunits rescued the abnormal Golgi architecture caused by COG knockout. Collectively, these data indicate that both subcomplexes of the COG complex can perform most of COG function when permanently attached to membranes and that the cytosolic pool of COG is not completely essential to COG function.
BEL2ABM: agent-based simulation of static models in Biological Expression Language
Authors: Gündel Michaela , Hoyt Charles Tapley , Hofmann-Apitius Martin
Published: February 2018

While cause-and-effect knowledge assembly models encoded in Biological Expression Language are able to support generation of mechanistic hypotheses, they are static and limited in their ability to encode temporality. Here, we present BEL2ABM, a software for producing continuous, dynamic, executable agent-based models from BEL templates.

Availability and implementation

The tool has been developed in Java and NetLogo. Code, data and documentation are available under the Apache 2.0 License at https://github.com/pybel/bel2abm.

Supplementary information

Supplementary data are available at Bioinformatics online.
Factors Predicting Decisions About Technology Adoption Among Older Adults
Authors: Berkowsky Ronald W , Sharit Joseph , Czaja Sara J
Published: February 2018

Background and Objectives

Numerous technology applications are available that have the potential to improve the quality of life (QoL) of older adults. However, older adults are less likely to adopt new and emerging technologies and reap the potential benefits. This study examines factors that influence older adults’ decisions about the adoption of new technology.

Research Design and Methods

Fifty-two older adults participated in a mixed-method procedure, which entailed: (1) observing presentations detailing nine differing technologies, (2) assessing the technologies using tailored questionnaires, and (3) participating in focus group discussions. Participants were assigned into one of seven groups separated by age (65–74, 75+) and language (English, Spanish). The outcome was willingness to adopt technology. Predictors included self-assessed abilities (e.g., numeric ability), computer/Internet skills and knowledge, technology readiness, age, language, and technology ratings (e.g., perceived value). Analyses included Spearman’s ρ, t-tests, and regression analysis. Focus group discussions were examined for supportive examples.

Results

Self-assessed abilities and computer/Internet skills were predictive of willingness to adopt technologies although the relationship varied according to the technology examined. Technology readiness, age, and language group showed weak associations with the outcome. Of the technology ratings, perceived value, confidence in ability to learn the technology, and the perceived impact on QoL were the most robust predictors of willingness to adopt technology.

Discussion and Implications

Findings indicate that various stakeholders in technology adoption among older adults must be cognizant of a technology’s functionality and complexity as well as the characteristics and abilities of older adults. However, certain factors such as perceptions about the value of the technology and potential impact on QoL are also critically important to decisions regarding technology adoption among older people.
SN 2015as: a low-luminosity Type IIb supernova without an early light-curve peak
Authors: Gangopadhyay Anjasha , Misra Kuntal , Pastorello A , Sahu D K , Tomasella L , Tartaglia L , Singh Mridweeka , Dastidar Raya , Srivastav S , Ochner P , Brown Peter J , Anupama G C , Benetti S , Cappellaro E , Kumar Brajesh , Kumar Brijesh , Pandey S B
Published: February 2018

We present results of the photometric (from 3 to 509 d post-explosion) and spectroscopic (up to 230 d post-explosion) monitoring campaign of the He-rich Type IIb supernova (SN) 2015as. The (B − V) colour evolution of SN 2015as closely resemble those of SN 2008ax, suggesting that SN 2015as belongs to the SN IIb subgroup that does not show the early, short-duration photometric peak. The light curve of SN 2015as reaches the B-band maximum about 22 d after the explosion, at an absolute magnitude of −16.82 ± 0.18 mag. At ∼75 d after the explosion, its spectrum transitions from that of a SN II to a SN Ib. P Cygni features due to He i lines appear at around 30 d after explosion, indicating that the progenitor of SN 2015as was partially stripped. For SN 2015as, we estimate a 56Ni mass of ∼0.08 M⊙ and ejecta mass of 1.1–2.2 M⊙, which are similar to the values inferred for SN 2008ax. The quasi-bolometric analytical light-curve modelling suggests that the progenitor of SN 2015as has a modest mass (∼0.1 M⊙), a nearly compact (∼0.05 × 1013 cm) H envelope on top of a dense, compact (∼2 × 1011 cm) and a more massive (∼1.2 M⊙) He core. The analysis of the nebular phase spectra indicates that ∼0.44 M⊙ of O is ejected in the explosion. The intensity ratio of the [Ca ii]/[O i] nebular lines favours either a main-sequence progenitor mass of ∼15 M⊙ or a Wolf–Rayet star of 20 M⊙.
Protecting the Brain With Xenon Anesthesia for Neurosurgical Procedures
Authors: Rylova Anna , Maze Mervyn
Published: February 2018

Xenon possesses some, but not all, of the clinical features of an ideal anesthetic agent. Besides well-known advantages of rapid awakening, stable hemodynamics and lack of biotransformation, preclinical data lead to the expectation of xenon’s advantageous use for settings of acute ongoing brain injury; a single randomized clinical trial using an imaging biomarker for assessing brain injury corroborated xenon’s preclinical efficacy in protecting the brain from further injury. In this review, we discuss the mechanisms and hence the putative applications of xenon for brain protection in neurosurgery. Although the expense of this rare monoatomic gas will likely prevent its widespread penetration into routine clinical neurosurgical practice, we draw attention to the theoretical benefits of xenon anesthesia over other anesthetic regimens for awake craniotomy and for neurosurgery in older, high-risk, and sicker patients.
Peripheral Vasculitic Neuropathy Associated With Minocycline Use
Authors: Kang Min K. , Gupta Rajesh K. , Srinivasan Jayashri
Published: February 2018

We describe 2 patients presenting with multiplex mononeuritis, associated with skin manifestation, secondary to minocycline-induced vasculitis. One of the cases is associated neither with lupus nor polyarteritis nodosa. An extensive laboratory workup ruled out any possible underlying immunologic disorder. Electrodiagnostic studies were conducted to show axonal neuropathy in patchy and multifocal distribution consistent with multiplex mononeuritis. This diagnosis was confirmed with nerve biopsy. Withdrawing from the offending medication, minocycline, improved the patients' clinical condition and the quantitative serological measures.
Exercise Rehabilitation for Peripheral Artery Disease
Authors: McDermott Mary M.
Published: February 2018

Purpose:

To summarize evidence regarding exercise therapy for people with lower extremity peripheral artery disease (PAD).

Methods:

Literature was reviewed regarding optimal strategies for delivering exercise interventions for people with PAD. Randomized trial evidence and recent studies were emphasized.

Results:

Randomized clinical trial evidence consistently demonstrates that supervised treadmill exercise improves treadmill walking performance in people with PAD. A meta-analysis of 25 randomized trials (1054 participants) concluded that supervised treadmill exercise was associated with 180 m of improvement in maximal treadmill walking distance and 128 m of improvement in pain-free walking distance compared with a control group. Three randomized trials of 493 patients with PAD demonstrated that home-based walking exercise interventions that incorporate behavioral change techniques improve walking ability in patients with PAD. Furthermore, evidence suggests that home-based walking exercise improves the 6-min walk more than supervised treadmill exercise. Upper and lower extremity ergometry also significantly improved walking endurance in PAD. The Centers for Medicare & Medicaid Services recently determined that Medicare would cover 12 wk (36 sessions) of supervised treadmill exercise for patients with PAD.

Conclusions:

Supervised treadmill exercise and home-based walking exercise each improve walking ability in patients with PAD. The availability of insurance coverage for supervised treadmill exercise for patients with PAD will make supervised treadmill exercise more widely available and accessible. Home-based exercise that incorporates behavioral change technique is an effective alternative for patients unwilling or unable to attend 3 supervised exercise sessions per week.
Ketamine-Associated Brain Changes: A Review of the Neuroimaging Literature
Authors: Ionescu Dawn F. , Felicione Julia M. , Gosai Aishwarya , Cusin Cristina , Shin Philip , Shapero Benjamin G. , Deckersbach Thilo
Published: February 2018

Major depressive disorder (MDD) is one of the most prevalent conditions in psychiatry. Patients who do not respond to traditional monoaminergic antidepressant treatments have an especially difficult-to-treat type of MDD termed treatment-resistant depression. Subanesthetic doses of ketamine—a glutamatergic modulator—have shown great promise for rapidly treating patients with the most severe forms of depression. As such, ketamine represents a promising probe for understanding the pathophysiology of depression and treatment response. Through neuroimaging, ketamine’s mechanism may be elucidated in humans. Here, we review 47 articles of ketamine’s effects as revealed by neuroimaging studies. Some important brain areas emerge, especially the subgenual anterior cingulate cortex. Furthermore, ketamine may decrease the ability to self-monitor, may increase emotional blunting, and may increase activity in reward processing. Further studies are needed, however, to elucidate ketamine’s mechanism of antidepressant action.
A new prognostic score can predict survival after hepatocellular carcinoma treatment in a cohort of 1302 Egyptian hepatocellular carcinoma patients
Authors: Abdelaziz Ashraf O. , Shousha Hend I. , Abdelmaksoud Ahmed H. , Saad Yasmin , Elbaz Tamer M. , Soliman Zeinab A. , Salah Ayman , Lithy Rania , Ahmed Mona , Nabil Mohamed M.
Published: February 2018

Introduction

Survival of hepatocellular carcinoma (HCC) differs between regions and countries according to the different underlying factors and the degree of standard of care that enables early diagnosis and management. Our aim was to identify the most potent predictive factors of survival in Egyptian HCC patients receiving curative or palliative treatments.

Patients and methods

This retrospective study included 1302 HCC patients attending the HCC multidisciplinary clinic, Cairo University, between February 2009 and December 2016. Clinical, laboratory, tumor characteristics, and treatment data were collected. Prognostic scores for each of the treatment categories, curative or palliative, were developed using routine laboratory tests.

Results

Patients were predominantly men, mean age 57.79±7.56 years. All cases developed HCC in addition to cirrhosis, mainly hepatitis C virus-related (88.2%). Most of the patients were Child–Pugh A (56.8%) or B (34.4%) and had single lesions. Transarterial chemoembolization was the most common line of treatment (42.08%). The overall median survival was 18.3 months from the date of diagnosis. Cigarette smoking, Child–Pugh score, performance status, number and size of the focal lesion, α-fetoprotein, and application of a specific treatment, particularly curative treatment, were the significant independent prognostic factors for survival. We found no impact of diabetes mellitus or hypertension on survival. Multidisciplinary HCC clinic predictive scores of survival after palliative and curative treatments were developed including independent prognostic factors, age, and portal vein status.

Conclusion

A new Egyptian prognostic score of tumor and patients factors can predict the survival of patients with HCC after palliative and curative treatments.
Expansion Vibration Lipofilling: A New Technique in Large-Volume Fat Transplantation
Authors: Del Vecchio Daniel , Wall Simeon
Published: February 2018

Background:

Despite rapid growth, gluteal fat transplantation is an operation in search of science and a teachable technique. Long operating times, tedious syringe transfers, inability to shape the recipient site, and the risk of fat embolism all headline as impediments to clinical adoption of the procedure. Expansion vibration lipofilling is a syringe-free surgical strategy that is a logical extension of Separation, Aspiration, and Fat Equalization (SAFELipo). In expansion vibration lipofilling, there is simultaneous disruption of recipient-site connective tissue, internal expansion using exploded-tip cannulas, and backfilling of these spaces with roller pump–propelled fat.

Methods:

Two thousand four hundred nineteen consecutive cases of expansion vibration lipofilling fat transplantation to the buttocks were reviewed. Average follow-up was 12 months. The technique of expansion vibration lipofilling is dependent on the use of larger caliber cannulas attached to a roller pump and to an oscillatory power-assisted liposuction device, which is less labor-intensive, potentially allowing for better knowledge of cannula-tip location at all times during the procedure.

Results:

Operating times averaged 1 hour 40 minutes. The average volume of fat inserted was 1003 cc. Complications included donor-site seroma, infection, and one pulmonary embolism treated with anticoagulation. There were no cases of fat embolism or death.

Conclusions:

Expansion vibration lipofilling is a new method for large-volume fat transplantation. Avoidance of fatal fat emboli demands a surgeon’s complete knowledge of cannula tip location at all times during the procedure. Syringe-free, larger caliber, and less flexible cannulas, combined with techniques requiring less operator upper extremity effort resulting in less fatigue, may contribute to avoidance of this dreadful complication.

CLINICAL QUESTION/LEVEL OF EVIDENCE:

Therapeutic, IV.
Elevated Cell-Free Mitochondrial DNA in Filtered Plasma Is Associated With HIV Infection and Inflammation
Authors: Arshad Omair , Gadawska Izabella , Sattha Beheroze , Côté Hélène C. F. , Hsieh Anthony Y. Y. ,   for the Canadian Institutes of Health Research Team on Cellular Aging and HIV Comorbidities in Women and Children (CARMA)
Published: February 2018

Background:

Increased cell-free DNA levels are associated with poor health outcomes, and cell-free mitochondrial DNA (cf-mtDNA) has proinflammatory properties. Given that HIV infection is associated with chronic inflammation, we investigated the relationship between cf-mtDNA and proinflammatory cytokine interleukin-6 (IL-6) in the context of HIV infection. We also optimized separation of cell-free plasma from blood.

Setting:

In this retrospective cross-sectional study, we collected blood, demographic information, and clinical data from 99 HIV-infected and 103 HIV-uninfected adults and children enrolled in the Children and Women: AntiRetrovirals and Markers of Aging pan-Canadian (CARMA) cohort.

Methods:

Plasma was separated from blood by 14,000g centrifugation followed by 0.45-μm filtration to remove cells and platelets. Cf-mtDNA and cell-free nuclear DNA were quantified simultaneously via monochrome, multiplex, quantitative polymerase chain reaction. IL-6 was measured using enzyme-linked immunosorbent assay.

Results:

Higher speed centrifugation and filtration was necessary to isolate truly cell-free plasma. Higher cf-mtDNA levels were univariately associated with HIV infection, elevated IL-6 levels, younger age, higher white blood cell count, and higher cell-free nuclear DNA levels but not blood mtDNA content or HIV viral load. In a multivariable model, HIV infection (P < 0.001), elevated IL-6 (P = 0.021), younger age (P < 0.001), and higher blood nDNA levels (P = 0.007) were independently associated with higher cf-mtDNA.

Conclusions:

People living with HIV have higher levels of circulating cf-mtDNA than their uninfected peers. Increased levels of inflammatory marker IL-6 are associated with elevated cf-mtDNA, independent of the effect of HIV infection. Higher cf-mtDNA levels and white blood cell count in younger people may reflect higher cell turnover in that population.
99mTc-MDP SPECT-CT and Ultrasound in the Diagnosis and Staging of Thyroid Metastasis From Osteosarcoma
Authors: Roll Wolfgang , Weckesser Matthias , Pöppelmann Monika , Schiborr Manfred , Schäfers Michael , Rahbar Kambiz
Published: February 2018

The classification of thyroid nodules in children is often difficult, especially in pretreated patients with metastatic disease. In osteosarcoma patients,99mTc-MDP SPECT/CT is used for primary and follow-up staging. Bone and soft tissue metastases can be revealed because of99mTc-MDP imaging of osteoid-producing metastases. We present99mTc-MDP SPECT-CT, CT, and ultrasound images of a highly suspicious calcified thyroid lesion in a 17-year-old boy with osteosarcoma. High uptake in99mTc-MDP SPECT-CT provides diagnosis of thyroid metastasis of osteosarcoma, which was proven by histopathology.
Seizure-Induced Increased 18F-DOPA Uptake in a Child With Diffuse Astrocytoma and Transient Brain MRI Abnormalities Related to Status Epilepticus
Authors: Morana Giovanni , Bottoni Gianluca , Mancardi Maria Margherita , Verrico Antonio , Piccardo Arnoldo
Published: February 2018

We report the finding of increased 18F-DOPA uptake in the brain parenchyma surrounding a temporoparietal low-grade diffuse astrocytoma and corresponding to transient seizure-induced MRI abnormalities. There was concomitant markedly increased tumoral uptake. This 18F-DOPA PET phenomenon may represent increased amino acid transport induced by seizures. In the setting of brain tumor imaging, increased 18F-DOPA uptake of low-grade epileptogenic tumors and adjacent brain parenchyma should be carefully interpreted in light of clinical and electroencephalographic findings related to seizure activity.
The Impact of Surgeons on the Likelihood of Mastectomy in Breast Cancer
Authors: Boero Isabel J. , Paravati Anthony J. , Hou Jiayi , Gillespie Erin F. , Schoenbrunner Anna , Unkart Jonathan , Wallace Anne M. , Einck John P. , Mell Loren K. , Murphy James D.
Published: February 2018

Objective:

This study evaluates the impact of individual surgeons and institutions on the use of mastectomy or breast conserving surgery (BCS) among elderly women with breast cancer.

Summary of Background Data:

Current literature characterizes patient clinical and demographic factors that increase likelihood of mastectomy use. However, the impact of the individual provider or institution is not well understood, and could provide key insights to biases in the decision-making process.

Methods:

A retrospective cohort study of 29,358 women 65 years or older derived from the SEER-Medicare linked database with localized breast cancer diagnosed from 2000 to 2009. Multilevel, multivariable logistic models were employed, with odds ratios (ORs) used to describe the impact of demographic or clinical covariates, and the median OR (MOR) used to describe the relative impact of the surgeon and institution.

Results:

Six thousand five hundred ninety-four women (22.4%) underwent mastectomy. Unadjusted rates of mastectomy ranged from 0% in the bottom quintile of surgeons to 58.0% in the top quintile. On multivariable analysis, the individual surgeon (MOR 1.97) had a greater impact on mastectomy than did the institution (MOR 1.71) or all other clinical and demographic variables except tumor size (OR 3.06) and nodal status (OR 2.95). Surgeons with more years in practice, or those with a lower case volume were more likely to perform mastectomy (P < 0.05).

Conclusion:

The individual surgeon influences the likelihood of mastectomy for the treatment of localized breast cancer. Further research should focus on physician-related biases that influence this decision to ensure patient autonomy.
An Economic Evaluation of the National Surgical Quality Improvement Program (NSQIP) in Alberta, Canada
Authors: Thanh Nguyen X. , Baron Tim , Litvinchuk Stacey
Published: February 2018

Objective:

The aim of this study was to analyze the health care costs and savings associated with quality improvement (QI) interventions initiated and implemented utilizing NSQIP.

Background:

Five acute care facilities of Alberta Health Services (AHS) adopted NSQIP in 2015 for a pilot project.

Methods:

The cost-savings of NSQIP were estimated from the start of NSQIP to the end of 2017 under an AHS perspective using this formula: Gross cost-savings = N ∗ (p1 – p2) ∗ unit cost, where N was the number of surgical patients after the intervention, p1 was the probability of event occurrence (within 30 days of surgery) before the intervention, p2 was the probability of event occurrence after the intervention, and unit cost is health care cost per event. To calculate the net cost-savings, we deducted the costs of NSQIP and its interventions from the gross cost-savings.

Results:

The QI initiatives initiated by NSQIP to reduce surgical events had significant impacts clinically and economically. The gross cost-savings of NSQIP were estimated at $11.4 million. Subtracting the costs of NSQIP and its interventions ($2.6 million) from the gross cost-savings, the net cost-savings were $8.8 million. The return on investment ratio was 4.3, meaning that every $1.00 invested in NSQIP would bring $4.30 in returns. The sensitivity analysis showed the probability for NSQIP to be cost-saving was 95%.

Conclusion:

QI interventions initiated and implemented utilizing NSQIP appear to be effective and cost-saving for AHS. These cost-savings would be even larger if NSQIP was prolonged in the pilot sites and/or expanded to other sites across the province.
Resident Autonomy in the Operating Room
Authors: Chen Xiaodong (Phoenix) , Sullivan Amy M. , Smink Douglas S. , Alseidi Adnan , Bengtson Joan M. , Kwakye Gifty , Dalrymple John L.
Published: February 2018

Objective:

This study aimed to identify the empirical processes and evidence that expert surgical teachers use to determine whether to take over certain steps or entrust the resident with autonomy to proceed during an operation.

Background:

Assessing real-time entrustability is inherent in attending surgeons’ determinations of residents’ intraoperative autonomy in the operating room. To promote residents’ autonomy, it is necessary to understand how attending surgeons evaluate residents’ performance and support opportunities for independent practice based on the assessment of their entrustability.

Methods:

We conducted qualitative semi-structured interviews with 43 expert surgical teachers from 21 institutions across 4 regions of the United States, using purposeful and snowball sampling. Participants represented a range of program types, program size, and clinical expertise. We applied the Framework Method of content analysis to iteratively analyze interview transcripts and identify emergent themes.

Results:

We identified a 3-phase process used by most expert surgical teachers in determining whether to take over intraoperatively or entrust the resident to proceed, including 1) monitoring performance and “red flags,” 2) assessing entrustability, and 3) granting autonomy. Factors associated with individual surgeons (eg, level of comfort, experience, leadership role) and the context (eg, patient safety, case, and time) influenced expert surgical teachers’ determinations of entrustability and residents’ final autonomy.

Conclusion:

Expert surgical teachers’ 3-phase process of decisions on take-over provides a potential framework that may help surgeons identify appropriate opportunities to develop residents’ progressive autonomy by engaging the resident in the determination of entrustability before deciding to take over.
Interdependence theory of tissue failure: bulk and boundary effects
Authors: Suma Daniel , Acun Aylin , Zorlutuna Pinar , Vural Dervis Can
Published: February 2018

The mortality rate of many complex multicellular organisms increases with age, which suggests that net ageing damage is accumulative, despite remodelling processes. But how exactly do these little mishaps in the cellular level accumulate and spread to become a systemic catastrophe? To address this question we present experiments with synthetic tissues, an analytical model consistent with experiments, and a number of implications that follow the analytical model. Our theoretical framework describes how shape, curvature and density influences the propagation of failure in a tissue subjected to oxidative damage. We propose that ageing is an emergent property governed by interaction between cells, and that intercellular processes play a role that is at least as important as intracellular ones.
Differential gene expression is not required for facultative sex allocation: a transcriptome analysis of brain tissue in the parasitoid waspNasonia vitripennis
Authors: Cook Nicola , Boulton Rebecca A. , Green Jade , Trivedi Urmi , Tauber Eran , Pannebakker Bart A. , Ritchie Michael G. , Shuker David M.
Published: February 2018

Whole-transcriptome technologies have been widely used in behavioural genetics to identify genes associated with the performance of a behaviour and provide clues to its mechanistic basis. Here, we consider the genetic basis of sex allocation behaviour in the parasitoid waspNasonia vitripennis. FemaleNasoniafacultatively vary their offspring sex ratio in line with Hamilton's theory of local mate competition (LMC). A single female or ‘foundress’ laying eggs on a patch will lay just enough sons to fertilize her daughters. As the number of ‘foundresses’ laying eggs on a patch increases (and LMC declines), females produce increasingly male-biased sex ratios. Phenotypic studies have revealed the cues females use to estimate the level of LMC their sons will experience, but our understanding of the genetics underlying sex allocation is limited. Here, we exposed females to three foundress number conditions, i.e. three LMC conditions, and allowed them to oviposit. mRNA was extracted from only the heads of these females to target the brain tissue. The subsequent RNA-seq experiment confirmed that differential gene expression is not associated with the response to sex allocation cues and that we must instead turn to the underlying neuroscience to reveal the underpinnings of this impressive behavioural plasticity.
A biomolecular proportional integral controller based on feedback regulations of protein level and activity
Authors: Mairet Francis
Published: February 2018

Homeostasis is the capacity of living organisms to keep internal conditions regulated at a constant level, despite environmental fluctuations. Integral feedback control is known to play a key role in this behaviour. Here, I show that a feedback system involving transcriptional and post-translational regulations of the same executor protein acts as a proportional integral (PI) controller, leading to enhanced transient performances in comparison with a classical integral loop. Such a biomolecular controller—which I call a level and activity-PI controller (LA-PI)—is involved in the regulation of ammonium uptake by
Escherichia coli
through the transporter AmtB. The P

II

molecules, which reflect the nitrogen status of the cell, inhibit both the production of AmtB and its activity (via the NtrB-NtrC system and the formation of a complex with GlnK, respectively). Other examples of LA-PI controller include copper and zinc transporters, and the redox regulation in photosynthesis. This scheme has thus emerged through evolution in many biological systems, surely because of the benefits it offers in terms of performances (rapid and perfect adaptation) and economy (protein production according to needs).
Mixing and diffusion in a two-type population
Authors: Izquierdo Segismundo S. , Izquierdo Luis R. , López-Pintado Dunia
Published: February 2018

The outbreak of epidemics, the rise of religious radicalization or the motivational influence of fellow students in classrooms are some of the issues that can be described as diffusion processes in heterogeneous groups. Understanding the role that interaction patterns between groups (e.g. homophily or segregation) play in the diffusion of certain traits or behaviours is a major challenge for contemporary societies. Here, we study the impact on diffusion processes of mixing (or, alternatively, segregating) two groups that present different sensitivities or propensities to contagion. We find non-monotonic effects of mixing and inefficient segregation levels, i.e. situations where a change in the mixing level can benefit both groups, e.g. where an increase in the mixing level can reduce the expected contagion levels in both groups. These findings can have fundamental consequences for the design of inclusion policies.
The emergence of consensus: a primer
Authors: Baronchelli Andrea
Published: February 2018

The origin of population-scale coordination has puzzled philosophers and scientists for centuries. Recently, game theory, evolutionary approaches and complex systems science have provided quantitative insights on the mechanisms of social consensus. However, the literature is vast and widely scattered across fields, making it hard for the single researcher to navigate it. This short review aims to provide a compact overview of the main dimensions over which the debate has unfolded and to discuss some representative examples. It focuses on those situations in which consensus emerges ‘spontaneously’ in the absence of centralized institutions and covers topics that include the macroscopic consequences of the different microscopic rules of behavioural contagion, the role of social networks and the mechanisms that prevent the formation of a consensus or alter it after it has emerged. Special attention is devoted to the recent wave of experiments on the emergence of consensus in social systems.
Estimating encounter rates as the first step of sexual selection in the lizardAnolis sagrei
Authors: Kamath Ambika , Losos Jonathan B.
Published: February 2018

How individuals move through their environment dictates which other individuals they encounter, determining their social and reproductive interactions and the extent to which they experience sexual selection. Specifically, females rarely have the option of mating with all males in a population—they can only choose among the males they encounter. Further, quantifying phenotypic differences between the males that females encounter and those that sire females' offspring lends insight into how social and reproductive interactions shape male phenotypes. We used an explicitly spatio-temporal Markov chain model to estimate the number of potential mates ofAnolis sagreilizards from their movement behaviour, and used genetic paternity assignments to quantify sexual selection on males. Females frequently encountered and mated with multiple males, offering ample opportunity for female mate choice. Sexual selection favoured males that were bigger and moved over larger areas, though the effect of body size cannot be disentangled from last-male precedence. Our approach corroborates some patterns of sexual selection previously hypothesized in anoles based on describing them as territorial, whereas other results, including female multiple mating itself, are at odds with territorial polygyny, offering insight into discrepancies in other taxa between behavioural and genetic descriptions of mating systems.
Polygamy or subdioecy? The impact of diallelic self-incompatibility on the sexual system in
Fraxinus excelsior
(Oleaceae)
Authors: Saumitou-Laprade Pierre , Vernet Philippe , Dowkiw Arnaud , Bertrand Sylvain , Billiard Sylvain , Albert Béatrice , Gouyon Pierre-Henri , Dufay Mathilde
Published: February 2018

How flowering plants have recurrently evolved from hermaphroditism to separate sexes (dioecy) is a central question in evolutionary biology. Here, we investigate whether diallelic self-incompatibility (DSI) is associated with sexual specialization in the polygamous common ash (
Fraxinus excelsior
), which would ultimately facilitate the evolution towards dioecy. Using interspecific crosses, we provide evidence of strong relationships between the DSI system and sexual phenotype. The reproductive system in
F. excelsior
that was previously viewed as polygamy (co-occurrence of unisexuals and hermaphrodites with varying degrees of allocation to the male and female functions) and thus appears to actually behave as a subdioecious system. Hermaphrodites and females belong to one SI group and functionally reproduce as females, whereas males and male-biased hermaphrodites belong to the other SI group and are functionally males. Our results offer an alternative mechanism for the evolution of sexual specialization in flowering plants.
A High-Resolution Genetic Map for the Laboratory Rat
Authors: Littrell John , Tsaih Shirng-Wern , Baud Amelie , Rastas Pasi , Solberg-Woods Leah , Flister Michael J
Published: February 2018

An accurate and high-resolution genetic map is critical for mapping complex traits, yet the resolution of the current rat genetic map is far lower than human and mouse, and has not been updated since the original ensen-Seaman map in 2004. For the first time, we have refined the rat genetic map to sub-centimorgan (cM) r solution (<0.02 cM) by using 95,769 genetic markers and 870 informative meioses from a cohort of 528 heterogeneous stock (HS) rats. Global recombination rates in the revised sex-averaged map (0.66 cM/Mb) did not difeer compared to the historical map (0.65 cM/Mb); however, substantial refinement was made to the localization of highly recombinant regions within the revised map. Also for the first time, sex-specific rat genetic maps were generated, which revealed both genomewide and fine-scale variation in recombination rates between male and female rats. Reanalysis of multiple quantitative trait loci (QTL) using the historical and refined rat genetic maps demonstrated marked changes to QTL localization, shape, and effect size. As a resource to the rat research community, we have provided revised centimorgan positions for all physical positions within the rat genome and commonly used genetic markers for trait mapping, including 44,828 SSLP markers and the RATDIV genotyping array. Collectively, this study provides a substantial improvement to the rat genetic map and an unprecedented resource for analysis of complex traits and recombination in the rat.
TRPV4 is the temperature-sensitive ion channel of human sperm
Authors: Mundt Nadine , Spehr Marc , Lishko Polina V.
Published: February 2018

Ion channels control sperm fertilizing ability by triggering hyperactivated motility, which is regulated by membrane potential, intracellular pH, and cytosolic calcium. Previous studies unraveled three essential ion channels that regulate these parameters: 1) the Ca2+channel CatSper, 2) the K+channel KSper, and 3) the H+channel Hv1. However, the molecular identity of an additional sperm Na+conductance that mediates initial membrane depolarization and, thus, triggers downstream signaling events is yet to be defined. Here, we functionally characterize DSper, the Depolarizing Channel of Sperm, as the temperature-activated channel TRPV4. It is functionally expressed at both mRNA and protein levels, while other temperature-sensitive TRPV channels are not functional in human sperm. DSper currents are activated by warm temperatures and mediate cation conductance, that shares a pharmacological profile reminiscent of TRPV4. Together, these results suggest that TRPV4 activation triggers initial membrane depolarization, facilitating both CatSper and Hv1 gating and, consequently, sperm hyperactivation.
Growth- and stress-related defects associated to wall hypoacetylation are strigolactone-dependent
Authors: Ramírez Vicente , Xiong Guangyan , Mashiguchi Kiyoshi , Yamaguchi Shinjiro , Pauly Markus
Published: February 2018

Mutants affected in the Arabidopsis TBL29/ESK1 xylan O-acetyltransferase display a strong reduction in total wall O-acetylation accompanied by a dwarfed plant stature, collapsed xylem morphology, and enhanced freezing tolerance. A newly identified tbl29/esk1 suppressor mutation affects the biosynthesis of strigolactones (SL) due to the reduced expression of the MAX4 gene. Genetic and biochemical evidence suggests that blocking the biosynthesis of SL is sufficient to recover all developmental and stress-related defects associated with the TBL29/ESK1 loss of function without affecting its direct effect - reduced wall O-acetylation. Altered levels of the MAX4 SL biosynthetic gene, reduced branch number, and higher levels of methyl carlactonoate, an active SL, were also found in tbl29/esk1 plants consistent with a constitutive activation of the SL pathway. These results indicate that the reduction of O-acetyl substituents in xylan is not directly responsible for the observed tbl29/esk1 phenotypes. Alternatively, plants may perceive defects in the structure of wall polymers and/or wall architecture activating the SL hormonal pathway as a compensatory mechanism.
Matrin 3-dependent neurotoxicity is modified by nucleic acid binding and nucleocytoplasmic localization
Authors: Malik Ahmed M. , Miguez Roberto A. , Li Xingli , Ho Ye-Shih , Feldman Eva L. , Barmada Sami J.
Published: February 2018

Abnormalities in nucleic acid processing are associated with the development of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Mutations inMatrin 3(MATR3), a poorly understood DNA- and RNA-binding protein, cause familial ALS/FTD, and MATR3 pathology is a feature of sporadic disease, suggesting that MATR3 dysfunction is integrally linked to ALS pathogenesis. Using a primary neuron model to assess MATR3-mediated toxicity, we noted that neurons were bidirectionally vulnerable to MATR3 levels, with pathogenic MATR3 mutants displaying enhanced toxicity. MATR3’s zinc finger domains partially modulated toxicity, but elimination of its RNA recognition motifs had no effect on neuronal survival, instead facilitating its self-assembly into liquid-like droplets. In contrast to other RNA-binding proteins associated with ALS, cytoplasmic MATR3 redistribution mitigated neurodegeneration, suggesting that nuclear MATR3 mediates toxicity. Our findings offer a foundation for understanding MATR3-related neurodegeneration and how nucleic acid binding functions, localization, and pathogenic mutations drive sporadic and familial disease.
Quantitative Genetic Analysis of the Maize Leaf Microbiome
Authors: Wallace Jason G. , Kremling Karl A. , Buckler Edward S.
Published: February 2018

The degree to which an organism can affect its associated microbial communities (“microbiome”) varies by organism and habitat, and in many cases is unknown. We address this question by analyzing the metabolically active bacteria of the maize phyllosphere across 300 diverse maize lines growing in a common environment. We performed comprehensive heritability analysis for 49 community diversity metrics, 380 bacterial clades (individual operational taxonomic units and higher-level groupings), and 9042 predicted metagenomic functions. We find that only a few few bacterial clades (5) and diversity metrics (2) are significantly heritable, while a much larger number of metabolic functions (200) are. Many of these associations appear to be driven by the amount of Methylobacteria present in each sample, and we find significant enrichment for traits relating to short-chain carbon metabolism, secretion, and nitrotoluene degradation. Genome-wide association analysis identifies a small number of associated loci for these heritable traits, including two loci (on maize chromosomes 7 and 10) that affect a large number of traits even after correcting for correlations among traits. This work is among the most comprehensive analyses of the maize phyllosphere to date. Our results indicate that while most of the maize phyllosphere composition is driven by environmental factors and/or stochastic founder events, a subset of bacterial taxa and metabolic functions is nonetheless significantly impacted by host plant genetics. Additional work will be needed to identify the exact nature of these interactions and what effects they may have on the phenotype of host plants.
Automatic Debye–Scherrer elliptical ring extractionviaa computer vision approach
Authors: Shahzad Saadia , Khan Nazar , Nawaz Zubair , Ferrero Claudio
Published: February 2018

The accurate calibration of powder diffraction data acquired from area detectors using calibration standards is a crucial step in the data reduction process to attain high-quality one-dimensional patterns. A novel algorithm has been developed for extracting Debye–Scherrer rings automatically using an approach based on computer vision and pattern recognition techniques. The presented technique requires no human intervention and, unlike previous approaches, makes no restrictive assumptions on the diffraction setup and/or rings. It can detect complete rings as well as portions of them, and works on several types of diffraction images with various degrees of ring graininess, textured diffraction patterns and detector tilt with respect to the incoming beam.
A new copper(II) supramolecular coordination polymer and a dinuclear compound with multifunctional 2-amino-5-sulfobenzoic acid and flexible N-donor ligands: synthesis, structure and characterization
Authors: Li Peng-Cheng , Zhang Kou-Lin
Published: February 2018

Multifunctional 2-amino-5-sulfobenzoic acid (H2afsb) can exhibit a variety of roles during the construction of supramolecular coordination polymers. The pendant carboxylic acid, sulfonic acid and amino groups could not only play a role in directing bonding but could also have the potential to act as hydrogen-bond donors and acceptors, resulting in extended high-dimensional supramolecular networks. Two new CuIIcoordination compounds, namelycatena-poly[[[diaquacopper(II)]-μ-1,6-bis(1H-1,2,4-triazol-1-yl)hexane-κ2N4:N4′] bis(3-amino-4-carboxybenzenesulfonate) dihydrate], {[Cu(C10H16N6)2(H2O)2](C7H6NO5S)2·2H2O}nor {[Cu(bth)2(H2O)2](Hafsb)2·2H2O}n, (1), and bis(μ-2-amino-5-sulfonatobenzoato-κ2O1:O1′)bis{μ-1,2-bis[(1H-imidazol-1-yl)methyl]benzene-κ2N3:N3′}bis[aquacopper(II)] trihydrate, [Cu2(C7H5NO5S)2(C14H14N4)2(H2O)2]·3H2O or [Cu2(afsb)2(obix)2(H2O)2]·3H2O, (2), have been obtained through the assembly between H2afsb and the CuIIion in the presence of the flexible N-donor ligands 1,6-bis(1H-1,2,4-triazol-1-yl)hexane (bth) and 1,2-bis[(1H-1,2,4-triazol-1-yl)methyl]benzene (obix), respectively. Compound (1) consists of a cationic coordination polymeric chain and 3-amino-4-carboxybenzenesulfonate (Hafsb−) anions. Compound (2) exhibits an asymmetric dinuclear structure. There are hydrogen-bonded networks within the lattices of (1) and (2). Interestingly, both (1) and (2) exhibit reversible dehydration–rehydration behaviour.
Impact of web banner advertising frequency on attitude
Authors: Hussain Rahim , Ferdous Ahmed Shahriar , Mort Gillian Sullivan
Published: February 2018

Purpose

The purpose of this paper is to examine whether advertising type (static or dynamic) and appeal (emotional or rational) moderate the relationship between web banner advertising frequency and consumer attitudinal response.

Design/methodology/approach

A laboratory experiment involving 400 participants was conducted to test for the moderating effect. Factorial ANOVA is used to measure brand attitude.

Findings

The results identified that the web banner advertisement type acted as a moderator between frequency and brand attitude. However, the moderating effect of banner advertisement appeal was found to be insignificant at a single banner advertisement frequency (i.e. exposure) but significantly different at a higher frequency. The study findings provide better directives for online marketers.

Practical implications

The major limitation is the fact that the impact of banner advertisement frequency was manipulated from one to five exposures. Future research needs to determine what happens after the fifth exposure, perhaps ten exposures or more, to determine the wear-out effect and in turn, to decide on the optimal frequency level in an effort to design more appropriate web communication strategies.

Social implications

The result shows that pop-up banner advertisements are intrusive, and that high level of exposures to pop-up banner advertisement could annoy online users. Thus, online advertisers should avoid repeating the pop-up banner advertisements because this could adversely affect the attitude towards the online advertising in general, and could also negatively influence attitudes towards the brand and ultimately effect online purchase.

Originality/value

This study contributes to the theory by providing more insights into the repetition effect, and comprehensive conclusions can be drawn based on the manipulation of banner advertisement frequency on different frequency levels. The research identifies that if the communication objective is to generate brand attitude, different strategies can be adopted depending on the banner advertisement type (pop-up vs static) and banner advertisement appeal (emotional vs rational).