bluuebunny/crossref_metadata_2025 huggingface dataset:
Does stigma curvature promote delayed selfing? An experimental investigation in Triodanis perfoliata (Campanulaceae)
Authors: Goodwillie C. , Patel H. R. , Dvorak D. M.
Published: December 2017

Self‐fertilisation that is delayed until after opportunities for outcrossing have ceased has been argued to provide both the reproductive assurance benefits of selfing and the genetic advantages of outcrossing. In the Campanulaceae, presentation of pollen on stylar hairs and progressive stigma curvature have been hypothesised to facilitate delayed selfing, but experimental tests are lacking. Stigma curvature is common in Campanula, a genus largely characterised by self‐incompatibility, and therefore is unlikely to have initially evolved to promote self‐fertilisation. In derived self‐compatible species, however, stigma curvature might serve the secondary function of delayed selfing.

We investigated delayed selfing in Triodanis perfoliata, a self‐compatible relative of Campanula. Using floral manipulation experiments and pollen tube observations, we quantified the extent and timing of self‐pollination. Further, we hypothesised that, if stigma curvature provides the benefit of delayed selfing in Triodanis, selection should have favoured retention of self‐pollen through the loss of a stylar hair retraction mechanism.

Results of a stigma removal experiment indicated that autonomous selfing produces partial seed set, but only some selfing was delayed. Pollen tube observations and a flower senescence assay also supported the finding of partial delayed selfing. Scanning electron microscopy revealed that pollen‐collecting hairs retract during anthesis, which may limit the extent of delayed selfing.

Delayed selfing appeared to be only partially effective in T. perfoliata. The stylar hair retraction in this species would seem to contradict selection for selfing. We suggest that caution and rigour are needed in interpreting floral traits as adaptive mechanisms for delayed selfing.
Non‐enzymatic antioxidant accumulations in BR‐deficient and BR‐insensitive barley mutants under control and drought conditions
Authors: Gruszka Damian , Janeczko Anna , Dziurka Michal , Pociecha Ewa , Fodor Jozsef
Published: December 2017

Drought is one of the most adverse stresses that affect plant growth and yield. Disturbances in metabolic activity resulting from drought cause overproduction of reactive oxygen species. It is postulated that brassinosteroids (BRs) regulate plant tolerance to the stress conditions, but the underlying mechanisms remain largely unknown. An involvement of endogenous BRs in regulation of the antioxidant homeostasis is not fully clarified either. Therefore, the aim of this study was to elucidate the role of endogenous BRs in regulation of non‐enzymatic antioxidants in barley (Hordeum vulgare) under control and drought conditions. The plant material included the ‘Bowman’ cultivar and a group of semi‐dwarf near‐isogenic lines (NILs), representing mutants deficient in BR biosynthesis or signaling. In general, accumulations of 11 compounds representing various types of non‐enzymatic antioxidants were analyzed under both conditions. The analyses of accumulations of reduced and oxidized forms of ascorbate indicated that the BR mutants contain significantly higher contents of dehydroascorbic acid under drought conditions when compared with the ‘Bowman’ cultivar. The analysis of glutathione accumulation indicated that under the control conditions the BR‐insensitive NILs contained significantly lower concentrations of this antioxidant when compared with the rest of genotypes. Therefore, we postulate that BR sensitivity is required for normal accumulation of glutathione. A complete accumulation profile of various tocopherols indicated that functional BR biosynthesis and signaling are required for their normal accumulation under both conditions. Results of this study provided an insight into the role of endogenous BRs in regulation of the non‐enzymatic antioxidant homeostasis.
Nitric oxide as a signaling molecule in brassinosteroid‐mediated virus resistance to Cucumber mosaic virus in Arabidopsis thaliana
Authors: Zou Li‐Juan , Deng Xing‐Guang , Zhang Li‐e , Zhu Tong , Tan Wen‐Rong , Muhammad Arfan , Zhu Li‐Jun , Zhang Chao , Zhang Da‐Wei , Lin Hong‐Hui
Published: December 2017

Brassinosteroids (BRs) are growth‐promoting plant hormones that play a crucial role in biotic stress responses. Here, we found that BR treatment increased nitric oxide (NO) accumulation, and a significant reduction of virus accumulation in Arabidopsis thaliana. However, the plants pre‐treated with NO scavenger [2‐(4‐carboxyphenyl)‐4,4,5,5‐tetramethyl‐imidazoline‐1‐1‐oxyl‐3‐oxide (PTIO)] or nitrate reductase (NR) inhibitor (tungstate) hardly had any NO generation and appeared to have the highest viral replication and suffer more damages. Furthermore, the antioxidant system and photosystem parameters were up‐regulated in brassinolide (BL)‐treated plants but down regulated in PTIO‐ or tungstate‐treated plants, suggesting NO may be involved in BRs‐induced virus resistance in Arabidopsis. Further evidence showed that NIA1 pathway was responsible for BR‐induced NO accumulation in Arabidopsis. These results indicated that NO participated in the BRs‐induced systemic resistance in Arabidopsis. As BL treatment could not increase NO levels in nia1 plants in comparison to nia2 plants. And nia1 mutant exhibited decreased virus resistance relative to Col‐0 or nia2 plants after BL treatment. Taken together, our study addressed that NIA1‐mediated NO biosynthesis is involved in BRs‐mediated virus resistance in A. thaliana.
Physiological coherence in healthy volunteers during laboratory‐induced stress and controlled breathing
Authors: Mejía‐Mejía Elisa , Torres Robinson , Restrepo Diana
Published: December 2017

Physiological coherence has been related with a general sense of well‐being and improvements in health and physical, social, and cognitive performance. The aim of this study was to evaluate the relationship between acute stress, controlled breathing, and physiological coherence, and the degree of body systems synchronization during a coherence‐generation exercise. Thirty‐four university employees were evaluated during a 20‐min test consisting of four stages of 5‐min duration each, during which basal measurements were obtained (Stage 1), acute stress was induced using validated mental stressors (Stroop test and mental arithmetic task, during Stage 2 and 3, respectively), and coherence states were generated using a controlled breathing technique (Stage 4). Physiological coherence and cardiorespiratory synchronization were assessed during each stage from heart rate variability, pulse transit time, and respiration. Coherence measurements derived from the three analyzed variables increased during controlled respiration. Moreover, signals synchronized during the controlled breathing stage, implying a cardiorespiratory synchronization was achieved by most participants. Hence, physiological coherence and cardiopulmonary synchronization, which could lead to improvements in health and better life quality, can be achieved using slow, controlled breathing exercises. Meanwhile, coherence measured during basal state and stressful situations did not show relevant differences using heart rate variability and pulse transit time. More studies are needed to evaluate the ability of coherence ratio to reflect acute stress.
Biomass smoke COPD: A phenotype or a different disease?
Authors: Perret Jennifer L. , Abramson Michael J.
Published: December 2017

See related Article
Genetic history of the African Sahelian populations
Authors: Černý V. , Kulichová I. , Poloni E. S. , Nunes J. M. , Pereira L. , Mayor A. , Sanchez‐Mazas A.
Published: December 2017

From a biogeographic perspective, Africa is subdivided into distinct horizontal belts. Human populations living along the Sahel/Savannah belt south of the Sahara desert have often been overshadowed by extensive studies focusing on other African populations such as hunter‐gatherers or Bantu in particular. However, the Sahel together with the Savannah bordering it in the south is a challenging region where people had and still have to cope with harsh climatic conditions and show resilient behaviours. Besides exponentially growing urban populations, several local groups leading various lifestyles and speaking languages belonging to three main linguistic families still live in rural localities across that region today. Thanks to several years of consistent population sampling throughout this area, the genetic history of the African Sahelian populations has been largely reconstructed and a deeper knowledge has been acquired regarding their adaptation to peculiar environments and/or subsistence modes. Distinct exposures to pathogens—in particular, malaria—likely contributed to their genetic differentiation for HLA genes. In addition, although food‐producing strategies spread within the Sahel/Savannah belt relatively recently, during the last five millennia according to recent archaeological and archaeobotanical studies, remarkable amounts of genetic differences are also observed between sedentary farmers and more mobile pastoralists at multiple neutral and selected loci, reflecting both demographic effects and genetic adaptations to distinct cultural traits, such as dietary habits.
Thorough analysis of unorthodox ABO deletions called by the 1000 Genomes project
Authors: Möller M. , Hellberg Å. , Olsson M. L.
Published: December 2017

Background and Objectives

ABO remains the clinically most important blood group system, but despite earlier extensive research, significant findings are still being made. The vast majority of catalogued ABO null alleles are based on the c.261delG polymorphism. Apart from c.802G>A, other mechanisms for O alleles are rare. While analysing the data set from the 1000 Genomes (1000G) project, we encountered two previously uncharacterized deletions, which needed further exploration.

Materials and Methods

The Erythrogene database, complemented with bioinformatics software, was used to analyse ABO in 2504 individuals from 1000G. DNA samples from selected 1000G donors and African blood donors were examined by allele‐specific PCR and Sanger sequencing to characterize predicted deletions.

Results

A 5821‐bp deletion encompassing exons 5‐7 was called in twenty 1000G individuals, predominantly Africans. This allele was confirmed and its exact deletion point defined by bioinformatic analyses and in vitro experiments. A PCR assay was developed, and screening of African samples revealed three donors heterozygous for this deletion, which was thereby phenotypically established as an O allele. Analysis of upstream genetic markers indicated an ancestral origin from ABO*O.01.02. We estimate this deletion as the 3rd most common mechanism behind O alleles. A 24‐bp deletion was called in nine individuals and showed greater diversity regarding ethnic distribution and allelic background. It could neither be confirmed by in silico nor in vitro experiments.

Conclusion

A previously uncharacterized ABO deletion among Africans was comprehensively mapped and a genotyping strategy devised. The false prediction of another deletion emphasizes the need for cautious interpretation of NGS data and calls for strict validation routines.
Effectiveness of platelet‐rich plasma therapy in wound healing of pilonidal sinus surgery: A comprehensive systematic review and meta‐analysis
Authors: Mostafaei Shayan , Norooznezhad Fatemeh , Mohammadi Saeed , Norooznezhad Amir Hossein
Published: December 2017

Pilonidal disease (PD) is a chronic situation which may cause pain, discomfort, inflammation, discharges, and inability to do daily routines. Among two main methods of surgery, open healing is preferred by surgeons since it associates with lower risk of recurrence; however, it could complicate the wound condition by delaying the healing process. For this meta‐analysis, a search in Medline, Embase, and Scopus was performed in June 2017 with no restrictions placed on the publication date or languages. Then, time to healing was considered as the effect size and all the data from trials were extracted. The heterogeneity and the variation in pooled estimation were assessed using Cochran's Q test and I‐squared, respectively. Meta‐regression was used to examine the relationship between the effect size and year, studies' sample sizes, proportion of male gender and age with the cause of heterogeneity. From 11 selected articles finally 4 met our inclusion and exclusion criteria with the total number of 484 patients. Using a fixed‐effect model, pool effect was detected 0.642 (95% CI: 0.485–0.798). A homogeneity of pooled effect size estimate for the studies was also found (Cochran Q test, p‐value = 0.844, I‐square = 0.0%). Moreover, results of meta‐regression showed no statistically significant association between the effect size and patients' mean age, year of publication, total sample size, and sex proportion (0.51 < p‐values < 0.98). Platelet‐rich plasma therapy for PD wounds appeared more effective than classic wound dressing.
Comparison of vegetarian versus animal-based low protein diets on estimated glomerular filtration rates in chronic kidney disease patients: a systematic review protocol
Authors: Patel Kruti , Hoover Kim W.
Published: December 2017

Review question/objective:

: The objective of this review is to evaluate studies to determine the effect of a low-protein, vegetarian diet as compared to a low-protein, animal-based diet on estimated glomerular filtration rates (eGFR) in adults with chronic kidney disease (CKD).
Interventions and programs that support the health and development of infants with prenatal alcohol and/or drug exposure in foster care: a scoping review protocol
Authors: Marcellus Lenora , Shaw Lindsey , MacKinnon Karen , Gordon Carol
Published: December 2017

Review question/objective:

The objective of this scoping review is to identify and describe caregiving interventions and program elements that support the health and development of infants with prenatal alcohol and/or drug exposure in foster care.
Efficacy and harms of pharmacological interventions for neurobehavioral symptoms in post traumatic amnesia after traumatic brain injury: a systematic review and meta-analysis protocol
Authors: Hicks Amelia J. , Clay Fiona J. , Hopwood Malcolm , Jayaram Mahesh , Batty Rachel , Ponsford Jennie L.
Published: December 2017

Review objective/question:

The objective of this systematic review is to synthesize the best available evidence on the effectiveness and harms of pharmacotherapy as compared to all types of comparators for the management of neurobehavioral symptoms in post-traumatic amnesia in adults aged 16 years and over who have sustained a traumatic brain injury. This review forms part of a larger project which aims to gather the evidence for the pharmacological treatment of neurobehavioral symptoms post traumatic brain injury as a prelude to the development of a clinical guideline.
Fibroblast growth factor 21 increases hepatic oxidative capacity but not physical activity or energy expenditure in hepatic peroxisome proliferator‐activated receptor γ coactivator‐1α‐deficient mice
Authors: Fletcher Justin A. , Linden Melissa A. , Sheldon Ryan D. , Meers Grace M. , Morris E. Matthew , Butterfield Anthony , Perfield James W. , Rector R. Scott , Thyfault John P.
Published: December 2017

New Findings

What is the central question of this study?

Does a reduction in hepatic peroxisome proliferator‐activated receptor γ coactivator‐1α (PGC‐1α), which has been observed in an insulin‐resistant obese state, impair the ability of fibroblast growth factor 21 (FGF21) to modulate metabolism?

What is the main finding and its importance?

A deficit in hepatic PGC‐1α does not compromise the ability of FGF21 to increase hepatic fatty acid oxidation; however, the effects of FGF21 to regulate whole‐body metabolism (i.e. total and resting energy expenditure), as well as ambulatory activity, were altered when hepatic PGC‐1α was reduced.

Fibroblast growth factor 21 (FGF21) treatment drives metabolic improvements, including increased metabolic flux and reduced hepatic steatosis, but the mechanisms responsible for these effects remain to be elucidated fully. We tested whether a targeted reduction in hepatic peroxisome proliferator‐activated receptor γ coactivator‐1α (PGC‐1α), which has been shown to occur with obesity, had a negative impact on the metabolic effects of FGF21. We infused FGF21 (1 mg kg−1 day−1) or saline in chow‐fed wild‐type (WT) and liver‐specific PGC‐1α heterozygous (LPGC‐1α) mice for 4 weeks. Administration of FGF21 lowered serum insulin and cholesterol (P ≤ 0.05) and tended to lower free fatty acids (P = 0.057). The LPGC‐1α mice exhibited reduced complete hepatic fatty acid oxidation (FAO; LPGC‐1α, 1788 ± 165 nmol g−1 h−1 compared with WT, 2572 ± 437 nmol g−1 h−1; P < 0.001), which was normalized by FGF21 treatment (2788 ± 519 nmol g−1 h−1; P < 0.001). FGF21 also increased hepatic incomplete FAO by 12% in both groups and extramitochondrial FAO by 89 and 56% in WT and LPGC‐1α mice, respectfully (P = 0.001), and lowered hepatic triacylglycerol by 30–40% (P < 0.001). Chronic treatment with FGF21 lowered body weight and fat mass (P < 0.05), while increasing food consumption (P < 0.05), total energy expenditure [7.3 ± 0.60 versus 6.6 ± 0.39 kcal (12 h)−1 in WT mice; P = 0.009] and resting energy expenditure [5.4 ± 0.89 versus 4.6 ± 0.21 kcal (12 h)−1 in WT mice; P = 0.005]. Interestingly, FGF21 only increased ambulatory activity in the WT mice (P = 0.03), without a concomitant increase in non‐resting energy expenditure. In conclusion, although reduced hepatic PGC‐1α expression was not necessary for FGF21 to increase FAO, it does appear to mediate FGF21‐induced changes in total and resting energy expenditure and ambulatory activity in lean mice.
Hypothalamic paraventricular nucleus neuronal nitric oxide synthase activity is a major determinant of renal sympathetic discharge in conscious Wistar rats
Authors: McBryde F. D. , Liu B. H. , Roloff E. V. , Kasparov S. , Paton J. F. R.
Published: December 2017

New Findings

What is the central question of this study?

Does chronic reduction of neuronally generated nitric oxide in the hypothalamic paraventricular nucleus affect the set‐point regulation of blood pressure and sympathetic activity destined to the kidneys?

What is the main finding and its importance?

Within the hypothalamic paraventricular nucleus, nitric oxide generated by neuronal nitric oxide synthase plays a major constitutive role in suppressing long term the levels of both ongoing renal sympathetic activity and arterial pressure in conscious Wistar rats. This finding unequivocally demonstrates a mechanism by which the diencephalon exerts a tonic influence on sympathetic discharge to the kidney and may provide the basis for both blood volume and osmolality homeostasis.

The paraventricular nucleus (PVN) of the hypothalamus plays a crucial role in cardiovascular and neuroendocrine regulation. Application of nitric oxide donors to the PVN stimulates GABAergic transmission, and may suppress sympathetic nerve activity (SNA) to lower arterial pressure. However, the role of endogenous nitric oxide within the PVN in regulating renal SNA chronically remains to be established in conscious animals. To address this, we used our previously established lentiviral vectors to knock down neuronal nitric oxide synthase (nNOS) selectively in the PVN of conscious Wistar rats. Blood pressure and renal SNA were monitored simultaneously and continuously for 21 days (n = 14) using radio‐telemetry. Renal SNA was normalized to maximal evoked discharge and expressed as a percentage change from baseline. The PVN was microinjected bilaterally with a neurone‐specific tetracycline‐controllable lentiviral vector, expressing a short hairpin miRNA30 interference system targeting nNOS (n = 7) or expressing a mis‐sense as control (n = 7). Recordings continued for a further 18 days. The vectors also expressed green fluorescent protein, and successful expression in the PVN and nNOS knockdown were confirmed histologically post hoc. Knockdown of nNOS expression in the PVN resulted in a sustained increase in blood pressure (from 95 ± 2 to 104 ± 3 mmHg, P < 0.05), with robust concurrent sustained activation of renal SNA (>70%, P < 0.05). The study reveals a major role for nNOS‐derived nitric oxide within the PVN in chronic set‐point regulation of cardiovascular autonomic activity in the conscious, normotensive rat.
Entry Lengths of Laminar Pipe and Channel Flows
Authors: Joshi Yash , Vinoth B. R.
Published: December 2017

Numerical simulations of laminar pipe and channel flows were carried out: (i) to understand the effect of inlet conditions, viz., flat inlet and streamtube inlet, on entry lengths, and (ii) to investigate the flow development in radial/transverse locations. Results show that hydrodynamic entry lengths from the streamtube inlet simulations are significantly lower compared to the entry lengths from the flat inlet simulations for low Reynolds numbers. Moreover, results from the current study (Newtonian flow with no-slip) as well as the results from the literature (non-Newtonian flow with no-slip) showed that for many flow situations, the slowest development of axial velocity in the transverse location happens to be very near to the wall. For the above cases, the existing entry length criteria (centerline as well as global entry length) are not appropriate to define the entry length. We have proposed a new entry length criterion based on the displacement thickness which is an integral measure of the velocity profile. A new entry length correlation using the displacement thickness criterion is proposed for Newtonian flows in pipe and channel based on simulations with the streamtube inlet condition.
Hot Deformation Behavior of Four Steels: A Comparative Study
Authors: Menapace C. , Sartori N. , Pellizzari M. , Straffelini G.
Published: December 2017

The hot deformation behavior of four different steels in the as-cast condition was investigated by means of hot compression tests conducted at temperatures ranging from 1100 °C up to 1200 °C, and at strain rates in between 0.12 and 2.4 s−1. The primary focus of this work was to check the possibility to increase the strain rate during the rough preliminary working of the ingots, i.e., to adopt a rough rolling process in place of the more conventional rough forging. The second aim of the research was to study the influence of the different characteristics of these steels in their as-cast conditions on their hot deformation behavior. It was seen that in all deformation conditions, the stress–strain compression curves show a single peak, indicating the occurrence of dynamic recrystallization (DRX). The hot deformation behavior was studied in both the condition of dynamic recovery (DRV), modeling the stress–strain curves in the initial stage of deformation, and DRX. Data of modeling were satisfactorily employed to estimate the flow stress under different conditions of temperature and strain rate. The experimental values of the activation energy for hot deformation, QHW, were determined and correlated to the chemical composition of the steels; a power law curve was found to describe the relation of QHW and the total amount of substitutional elements of the steels. The critical strain for DRX, εc, was determined as a function of the Zener–Hollomon parameter and correlated to the peak strain, εp. A ratio εc/εp in the range 0.45–0.65 was found, which is in agreement with literature data. All this information is crucial for a correct design of the rough deformation process of the produced ingots.
Atomistic Energetics and Critical Twinning Stress Prediction in Face and Body Centered Cubic Metals: Recent Progress
Authors: Chowdhury Piyas , Sehitoglu Huseyin
Published: December 2017

This paper recounts recent advances on the atomistic modeling of twinning in body-centered cubic (bcc) and face-centered cubic (fcc) alloy. Specifically, we have reviewed: (i) the experimental evidence of twinning-dominated deformation in single- and multi-grain microstructures, (ii) calculation of generalized planar fault energy (GPFE) landscapes, and (iii) the prediction of critical friction stresses to initiate twinning-governed plasticity (e.g., twin nucleation, twin–slip and twin–twin interactions). Possible avenues for further research are outlined.
Turbulence Over a Pair of Submerged Hemispheres in Presence of Surface Waves and Following Current
Authors: Barman Krishnendu , Debnath Koustuv , Mazumder Bijoy S.
Published: December 2017

The paper presents an experimental study in a laboratory flume to investigate the combined wave–current flow over a pair of hemispherical obstacles placed at a relative spacing L/d = 4, where L is a center to center distance between the obstacles and d is the obstacle height. Detailed velocity data were collected using three-dimensional micro-acoustic Doppler velocimeter from upstream to downstream of the pair of obstacles along the centerline of the flume. This study examines the mean flows, eddy viscosity, mixing length, turbulence kinetic energy (TKE) flux under the influence of two hemispherical obstacles in combined wave–current flow conditions. The analysis reveals that higher level of turbulence including maximum eddy viscosity and TKE flux is observed near the top of the obstacles. Further, the power spectral density (PSD) for velocity fluctuation is also analyzed to study the internal structure of turbulence due to combined wave–current flow over hemispherical obstacles.
Surrogate Model Based Liner Optimization for Aeroengines and Comparison With Finite Elements
Authors: Jiang Hanbo , Siu Hong Lau Alex , Huang Xun
Published: December 2017

Numerical optimizations are very useful in liner designs for low-noise aeroengines. Although modern computational tools are already very efficient for a single aeroengine noise propagation simulation run, the prohibitively high computational cost of a broadband liner optimization process which requires hundreds of thousands of runs renders these tools unsuitable for such task. To enable rapid optimization using a desktop computer, an efficient analytical solver based on the Wiener–Hopf method is proposed in the current study. Although a Wiener–Hopf-based solver can produce predictions very quickly (order of a second), it usually assumes an idealized straight duct configuration with a uniform background flow that makes it arguable for practical applications. In the current study, we employ the Wiener–Hopf method in our solver to produce an optimized liner design for a semi-infinite annular duct setup and compare its noise-reduction effect with an optimized liner designed by the direct application of a numerical finite element solver for a practical aeroengine intake configuration with an inhomogeneous background flow. The near-identical near- and far-field solutions by the Wiener–Hopf-based method and the finite element solvers clearly demonstrate the accuracy and high efficiency of the proposed optimization strategy. Therefore, the current Wiener–Hopf solver is highly effective for liner optimizations with practical setups and is very useful to the preliminary design process of low-noise aeroengines.
NASA sensor to study space junk the size of dust
Authors: Loomis Ilima
Published: December 2017

Data could help satellitemakers avoid deadly microdebris.
Last stands
Authors: Stokstad Erik
Published: December 2017

Foresters and ecologists face off over the future of Europe's oldest forest.
Signatures of exciton condensation in a transition metal dichalcogenide
Authors: Kogar Anshul , Rak Melinda S. , Vig Sean , Husain Ali A. , Flicker Felix , Joe Young Il , Venema Luc , MacDougall Greg J. , Chiang Tai C. , Fradkin Eduardo , van Wezel Jasper , Abbamonte Peter
Published: December 2017

Probing an excitonic condensate

Excitons—bound states of electrons and holes in solids—are expected to form a Bose condensate at sufficiently low temperatures. Excitonic condensation has been studied in systems such as quantum Hall bilayers where physical separation between electrons and holes enables a longer lifetime for their bound states. Kogar
et al.
observed excitons condensing in the three-dimensional semimetal 1
T
-TiSe
2
. In such systems, distinguishing exciton condensation from other types of order is tricky. To do so, the authors used momentum-resolved electron energy-loss spectroscopy, a technique developed to probe electronic collective excitations. The energy needed to excite an electronic mode became negligible at a finite momentum, signifying the formation of a condensate.

Science
, this issue p.
1314
Structure of the cold- and menthol-sensing ion channel TRPM8
Authors: Yin Ying , Wu Mengyu , Zubcevic Lejla , Borschel William F. , Lander Gabriel C. , Lee Seok-Yong
Published: December 2017

Architecture of the TRPM subfamily

Transient receptor potential melastatin (TRPM) ion channels constitute the largest TRP subfamily and are involved in many physiological processes. TRPM8 is the primary cold and menthol sensor, and TRPM4 is associated with cardiovascular disorders. Yin
et al.
and Autzen
et al.
shed light on the general architecture of the TRPM subfamily by solving the structures of TRPM8 and TRPM4, respectively (see the Perspective by Bae
et al.
). The three-layered architecture of the TRPM8 channel provides the framework for understanding the mechanisms of cold and menthol sensing. The two distinct closed states of TRPM4, with and without calcium, reveal a calcium-binding site and calcium-binding-induced conformational changes.

Science
, this issue p.
237
, p.
228
; see also p.
160
Quantized chiral edge conduction on domain walls of a magnetic topological insulator
Authors: Yasuda K. , Mogi M. , Yoshimi R. , Tsukazaki A. , Takahashi K. S. , Kawasaki M. , Kagawa F. , Tokura Y.
Published: December 2017

A magnetic tip reconfigures edge states

Topological phases of matter are characterized by invariants such as Chern numbers, which determine their global properties. On the boundary of two domains with different Chern numbers, chiral edge states are expected to form. Yasuda
et al.
engineered such states in samples of a quantum anomalous Hall material by creating magnetic domains using the tip of a magnetic force microscope. The existence of chiral edge states along the domain walls was confirmed with electrical transport measurements. The ability to reconfigure and manipulate these states may improve spintronics.

Science
, this issue p.
1311
Spatial reconstruction of immune niches by combining photoactivatable reporters and scRNA-seq
Authors: Medaglia Chiara , Giladi Amir , Stoler-Barak Liat , De Giovanni Marco , Salame Tomer Meir , Biram Adi , David Eyal , Li Hanjie , Iannacone Matteo , Shulman Ziv , Amit Ido
Published: December 2017

Spatial information from NICHE-seq

Immune functions depend on the interactions of heterogeneous cells in a range of microenvironments in the body. Although information regarding immune cell function has been collected using single-cell RNA-sequencing methods, these techniques have traditionally lacked spatial information. Medaglia
et al.
describe NICHE-seq, a technique that allows the sorting and analysis of cells from within visually selected territories in transgenic mice that express photoactivatable green fluorescent protein. The method successfully identified T and B cell-specific niches in mouse lymph nodes and spleens after virus infection. The approach will allow us to bridge the gap between cellular and spatial information in studies of organs.

Science
, this issue p.
1622
Aging and neurodegeneration are associated with increased mutations in single human neurons
Authors: Lodato Michael A. , Rodin Rachel E. , Bohrson Craig L. , Coulter Michael E. , Barton Alison R. , Kwon Minseok , Sherman Maxwell A. , Vitzthum Carl M. , Luquette Lovelace J. , Yandava Chandri N. , Yang Pengwei , Chittenden Thomas W. , Hatem Nicole E. , Ryu Steven C. , Woodworth Mollie B. , Park Peter J. , Walsh Christopher A.
Published: December 2017

Brain mutations, young and old

Most neurons that make up the human brain are postmitotic, living and functioning for a very long time without renewal (see the Perspective by Lee). Baeet al.examined the genomes of single neurons from the prenatal developing human brain. Both the type of mutation and the rates of accumulation changed between gastrulation and neurogenesis. These early mutations could be generating useful neuronal diversity or could predispose individuals to later dysfunction. Lodatoet al.also found that neurons take on somatic mutations as they age by sequencing single neurons from subjects aged 4 months to 82 years. Somatic mutations accumulated with increasing age and accumulated faster in individuals affected by inborn errors in DNA repair. Postmitotic mutations might only affect one neuron, but the accumulated divergence of genomes across the brain could affect function.

Science, this issue p.550, p.555; see also p.521
Patient HLA class I genotype influences cancer response to checkpoint blockade immunotherapy
Authors: Chowell Diego , Morris Luc G. T. , Grigg Claud M. , Weber Jeffrey K. , Samstein Robert M. , Makarov Vladimir , Kuo Fengshen , Kendall Sviatoslav M. , Requena David , Riaz Nadeem , Greenbaum Benjamin , Carroll James , Garon Edward , Hyman David M. , Zehir Ahmet , Solit David , Berger Michael , Zhou Ruhong , Rizvi Naiyer A. , Chan Timothy A.
Published: December 2017

HLA genotype affects response

Immunotherapy works by activating the patient's own immune system to fight cancer. For effective tumor killing, CD8
+
T cells recognize tumor peptides presented by human leukocyte antigen class I (HLA-I) molecules. In humans, there are three major HLA-I genes (
HLA-A, HLA-B
, and
HLA-C
). Chowell
et al.
asked whether germline HLA-I genotype influences how T cells recognize tumor peptides and respond to checkpoint inhibitor immunotherapies (see the Perspective by Kvistborg and Yewdell). They examined more than 1500 patients and found that heterozygosity at HLA-I loci was associated with better survival than homozygosity for one or more HLA-I genes. Thus, specific HLA-I mutations could have implications for immune recognition and for the design of epitopes for cancer vaccines and immunotherapies.

Science
, this issue p.
582
; see also p.
516
Attosecond-resolved photoionization of chiral molecules
Authors: Beaulieu S. , Comby A. , Clergerie A. , Caillat J. , Descamps D. , Dudovich N. , Fabre B. , Géneaux R. , Légaré F. , Petit S. , Pons B. , Porat G. , Ruchon T. , Taïeb R. , Blanchet V. , Mairesse Y.
Published: December 2017

Clocking departures from chiral origins

Just as the atoms in a molecule can be arranged in a left- or right-handed manner, the field in a beam of light can circulate like a left- or right-handed corkscrew. Matches or mismatches in this mutual handedness give rise to an asymmetric distribution of trajectories as electrons are ejected during photoionization. Beaulieu
et al.
used an interferometric approach to uncover the temporal dynamics associated with this asymmetry. They probed the mirror-image isomers of camphor with circularly polarized light, which revealed the angle-dependent delays between trajectories that spanned up to 24 attoseconds.

Science
, this issue p.
1288
Saving lives by regulating guns: Evidence for policy
Authors: Cook Philip J. , Donohue John J.
Published: December 2017

Despite obstacles, research is clarifying gun-policy impacts
Best books for curious kids
Authors: Thompson Valerie , Sills Jennifer , Fahrenkamp-Uppenbrink Julia , Wolner Catherine , Mervis Jeffrey , Lavine Marc S. , Zahn Laura M. , Chevlen Dorie , Cho Adrian , Funk Michael A. , Grocholski Brent , Nusinovich, Yevgeniya , Jenney Andrea , Kemp Christopher , Ucko Solomon , Ucko Hadassah , Murnane Rick
Published: December 2017

How does the Moon's influence on Earth's wobble affect the weather? Which animal earns the title of the world's deadliest? Can the Arctic undergo a drought? Even adults may struggle to articulate the answers to these seemingly simple questions. Fear not: This year's finalists for the Science Books and Films (SB&F) Prizes for Excellence in Science Books have you covered. Sponsored by Subaru and the American Association for the Advancement of Science (AAAS; the publisher of
Science
), this competi­tion celebrates books that promote science literacy among children and young adults and encourages the publication of high-quality science books for young readers. Winners in each category will be announced at the AAAS Annual Meeting in Austin, Texas, in February 2018. Until then, read on for reviews of the finalists written by the staff of the
Science
fam­ily of journals, with help from a few friends.
Social networks, leisure activities and maximum tongue pressure: cross-sectional associations in the Nagasaki Islands Study
Authors: Nagayoshi Mako , Higashi Miho , Takamura Noboru , Tamai Mami , Koyamatsu Jun , Yamanashi Hirotomo , Kadota Koichiro , Sato Shimpei , Kawashiri Shin-ya , Koyama Zenya , Saito Toshiyuki , Maeda Takahiro
Published: December 2017

Objectives

Social environment is often associated with health outcomes, but epidemiological evidence for its effect on oral frailty, a potential risk factor for aspiration, is sparse. This study aimed to assess the association between social environment and tongue pressure, as an important measure of oral function. The study focused on family structure, social networks both with and beyond neighbours, and participation in leisure activities.

Design

A population-based cross-sectional study.

Setting

Annual health check-ups in a rural community in Japan.

Participants

A total of 1982 participants, all over 40 years old. Anyone with missing data for the main outcome (n=14) was excluded.

Outcome measures

Tongue pressure was measured three times, and the maximum tongue pressure was used for analysis. A multivariable adjusted regression model was used to calculate parameter estimates (B) for tongue pressure.

Results

Having a social network involving neighbours (B=2.43, P=0.0001) and taking part in leisure activities (B=1.58, P=0.005) were independently associated with higher tongue pressure, but there was no link with social networks beyond neighbours (B=0.23, P=0.77). Sex-specific analyses showed that for men, having a partner was associated with higher tongue pressure, independent of the number of people in the household (B=2.26, P=0.01), but there was no association among women (B=−0.24, P=0.72; P-interaction=0.059).

Conclusions

Having a social network involving neighbours and taking part in leisure activities were independently associated with higher tongue pressure. Marital status may be an important factor in higher tongue pressure in men.
Anthracycline cardiotoxicity: an update on mechanisms, monitoring and prevention
Authors: Henriksen Peter A
Published: December 2017

Anthracycline chemotherapy causes dose-related cardiomyocyte injury and death leading to left ventricular dysfunction. Clinical heart failure may ensue in up to 5% of high-risk patients. Improved cancer survival together with better awareness of the late effects of cardiotoxicity has led to growing recognition of the need for surveillance of anthracycline-treated cancer survivors with early intervention to treat or prevent heart failure. The main mechanism of anthracycline cardiotoxicity is now thought to be through inhibition of topoisomerase 2β resulting in activation of cell death pathways and inhibition of mitochondrial biogenesis. In addition to cumulative anthracycline dose, age and pre-existing cardiac disease are risk markers for cardiotoxicity. Genetic susceptibility factors will help identify susceptible patients in the future. Cardiac imaging with echocardiographic measurement of global longitudinal strain and cardiac troponin detect early myocardial injury prior to the development of left ventricular dysfunction. There is no consensus on how best to monitor anthracycline cardiotoxicity although guidelines advocate quantification of left ventricular ejection fraction before and after chemotherapy with additional scanning being justified in high-risk patients. Patients developing significant left ventricular dysfunction with or without clinical heart failure should be treated according to established guidelines. Liposomal encapsulation reduces anthracycline cardiotoxicity. Dexrazoxane administration with anthracycline interferes with binding to topoisomerase 2β and reduces both cardiotoxicity and subsequent heart failure in high-risk patients. Angiotensin inhibition and β-blockade are also protective and appear to prevent the development of left ventricular dysfunction when given prior or during chemotherapy in patients exhibiting early signs of cardiotoxicity.
Dissecting spinal aneurysms: conservative management as a therapeutic option
Authors: Dabus Guilherme , Tosello Renato Tavares , Pereira Benedito J A , Linfante Italo , Piske Ronie L
Published: December 2017

Objective

Isolated dissecting spinal aneurysms are rare lesions that pose a therapeutic challenge. We report our experience in the management of four patients with dissecting spinal aneurysms.

Methods

After institutional review board approval was obtained, the neurointerventional databases of the two participating institutions were retrospectively reviewed. Aneurysms in the anterior spinal artery, posterior spinal artery, or in a radiculomedullary artery were included in the analysis. Flow-related aneurysms were excluded. Data on clinical presentation, hemorrhage location, aneurysm size, location, angiographic follow-up, re-hemorrhage, and clinical outcome were obtained and analyzed.

Results

Four patients with five spinal dissecting aneurysms met the inclusion criteria. There were two women and the mean age was 63 years (range 36–64). All patients presented with hemorrhage. Three radiculomedullary arteries in two different patients had one lesion each; the other two involved the anterior spinal artery and a posterior spinal artery in different patients. All four patients were managed conservatively. Follow-up angiography (5.5 months) demonstrated occlusion of all five aneurysms. There was no re-hemorrhage and all patients had a good outcome at the last follow-up (modified Rankin Scale score 0–2).

Conclusions

Conservative management of ruptured spontaneous dissecting spinal aneurysms is a reasonable therapeutic option capable of achieving favorable angiographic and clinical outcomes.
Bio-grouting to enhance axial pull-out response of pervious concrete ground improvement piles
Authors: Lin Hai , Suleiman Muhannad T. , Jabbour Hanna M. , Brown Derick G.
Published: December 2017

Bio-grouting is an environmentallly friendly, sustainable, and low-cost ground improvement technique, which mainly utilizes microbial-induced carbonate precipitation. Previous large-scale applications of MICP have encountered practical difficulties including bio-clogging, which resulted in a limited zone of cemented soil around injection points. The research presented in this paper focuses on evaluating the feasibility of cementing a limited soil zone surrounding permeable piles using MICP bio-grouting to improve the mechanical response of permeable piles under axial pull-out loading. Two instrumented pervious concrete piles (test units), one with and one without MICP bio-grouting, were subjected to pull-out loading at the Soil-Structure Interaction Facility at Lehigh University. The pervious concrete pile served as an injection point during the MICP bio-grouting. The mechanical responses of the test units and surrounding soil were analyzed, along with shear wave (S-wave) velocities, moisture, and CaCO3 contents of the surrounding soil. The results presented in this paper demonstrate that the limited MICP-improved zone, extending a radial distance of approximately 102 mm around pervious concrete piles, improved the load–displacement response, load transfer, and pile capacity under pull-out loading. The ratios between ultimate loads of the test units with and without MICP bio-grouting were 4.2. The average shaft resistance along the pile with MICP bio-grouting was up to 2.8 times higher than that of the pile without bio-grouting.
Long-term pine regeneration, shrub layer dynamics, and understory community composition responses to repeated prescribed fire in Pinus resinosa forests
Authors: Scherer Sawyer S. , Kern Christel C. , D’Amato Anthony W. , Palik Brian J. , Russell Matthew R.
Published: December 2017

Prescribed fire is increasingly viewed as a valuable tool for reversing ecological consequences of fire suppression within fire-adapted forests. While the use of burning treatments in northern temperate conifer forests has received considerable attention, the long-term (>10 year) effects on understory composition and dynamics have not been quantified. We describe the persistence of prescribed fire effects on the woody and herbaceous understory in a mature red pine (Pinus resinosa Ait.) forest in northern Minnesota, USA, over a ∼50-year period, as well as the relative roles of fire season and frequency in affecting vegetation responses. Burning treatments were applied from 1960 to 1970 on 0.4 ha experimental units and crossed fire season and frequency in a randomized block design. Burning altered shrub layer dynamics and composition in both the short and long terms and was influenced by both fire season and frequency, with frequent summer season burns having the largest impact, including greatest control of hazel (Corylus spp.). The application of fire facilitated regeneration of pine; however, recruitment into the overstory was limited. Additionally, community composition of the herbaceous understory diverged 40+ years following burning. This study highlights the importance of continued burning in affecting vegetation responses and the potential of fire as a long-lasting vegetation management tool in these forests.
Genetic classification of Aegilops columnaris Zhuk. (2n=4x=28, UcUcXcXc) chromosomes based on FISH analysis and substitution patterns in common wheat × Ae. columnaris introgressive lines
Authors: Badaeva E.D. , Ruban A.S. , Shishkina A.A. , Sibikeev S.N. , Druzhin A.E. , Surzhikov S.A. , Dragovich A.Yu.
Published: December 2017

Aegilops columnaris is a tetraploid species originated from Ae. umbellulata (2n=2x=14, UU) and a yet unknown diploid grass species. Although Ae. columnaris possesses some agronomically valuable traits, such as heat and drought tolerance and resistance to pests, it has never been used in wheat breeding because of difficulties in producing hybrids and a lack of information on the relationships between Ae. columnaris and common wheat chromosomes. In this paper, we report the development of 57 wheat – Ae. columnaris introgressive lines covering 8 of the14 chromosomes of Aegilops. Based on substitution spectra of hybrids and the results of FISH analysis of the parental Ae. columnaris line with seven DNA probes, we have developed the genetic nomenclature of the Uc and Xc chromosomes. Genetic groups and genome affinities were established for 11 of 14 chromosomes; the classification of the remaining three chromosomes remains unsolved. Each Ae. columnaris chromosome was characterized on the basis of C-banding pattern and the distribution of seven DNA sequences. Introgression processes were shown to depend on the parental wheat genotype and the level of divergence of homoeologous chromosomes. We found that lines carrying chromosome 5Xc are resistant to leaf rust; therefore, this chromosome could possess novel resistance genes that have never been utilized in wheat breeding.