bluuebunny/crossref_metadata_2025 huggingface dataset:
Paroxysmal atrioventricular block: Electrophysiological mechanism of phase 4 conduction block in the His‐Purkinje system: A comparison with phase 3 block
Authors: Shenasa Mohammad , Josephson Mark E. , Wit Andrew L.
Published: August 2017

Background

Paroxysmal atrioventricular (A‐V) block is relatively rare, and due to its transient nature, it is often under recognized. It is often triggered by atrial, junctional, or ventricular premature beats, and occurs in the presence of a diseased His‐Purkinje system (HPS). Here, we present a 45‐year‐old white male who was admitted for observation due to recurrent syncope and near‐syncope, who had paroxysmal A‐V block. The likely cellular electrophysiological mechanisms(s) of paroxysmal A‐V block and its differential diagnosis and management are discussed.

Methods

Continuous electrocardiographic monitoring was done while the patient was in the cardiac unit.

Results

Multiple episodes of paroxysmal A‐V block were documented in this case. All episodes were initiated and terminated with atrial/junctional premature beats. The patient underwent permanent pacemaker implantation and has remained asymptomatic since then.

Conclusions

Paroxysmal A‐V block is rare and often causes syncope or near‐syncope. Permanent pacemaker implantation is indicated according to the current guidelines. Paroxysmal A‐V block occurs in the setting of diseased HPS and is bradycardia‐dependent. The detailed electrophysiological mechanisms, which involve phase 4 diastolic depolarization, and differential diagnosis are discussed.
Lower airway dimensions in pediatric patients—A computed tomography study
Authors: Szelloe Patricia , Weiss Markus , Schraner Thomas , Dave Mital H.
Published: August 2017

Background

The aim of this study was to obtain lower airway dimensions in children by means of computed tomography (CT).

Methods

Chest CT scans from 195 pediatric patients (118 boys/77 girls) aged 0.04‐15.99 years were analyzed. Tracheal and bronchial lengths, anterior‐posterior and lateral diameters, as well as cross‐sectional area were assessed at the following levels: mid trachea, right proximal and distal bronchus, proximal bronchus intermedius, and left proximal and distal bronchus. Mediastinal angles of tracheal bifurcation were measured. Data were analyzed by means of linear and polynomial regression plots.

Results

The strongest correlations were found between tracheal and bronchial diameters and age as well as between tracheal and bronchial lengths and body length. All measured airway parameters correlated poorly to body weight. Bronchial angles revealed no association with patient's age, body length, or weight.

Conclusion

This comprehensive anatomical database of lower airway dimensions demonstrates that tracheal and bronchial diameters correlate better to age, and that tracheal and bronchial length correlate better to body length. All measured airway parameters correlated poorly to body weight.
Ethical issues in pediatric face transplantation
Authors: Benghiac Ana‐Gabriela , Garrett Jeremy R. , Carter Brian S.
Published: August 2017

Facial transplantation has become a reality in adult medicine. Children are subject to congenital craniofacial differences, disease‐related, traumatic, or thermochemical craniofacial changes and might be suitable for face transplantation. This manuscript addresses unique ethical issues in considering potential pediatric face transplant. These challenges are operant at the individual, technologic, and psychosocial level for clinicians, investigators, and society.
Safety of hematopoietic cell infusion in children with malignant and non‐malignant diseases
Authors: Heneghan Chelsea , Smilow Elana , Tanhehco Yvette , Jin Zhezhen , Cofnas Paige , Schwartz Sharon , Patel Nita , Carberry Deborah , Silverman Justin , Huynh Paul , Hagan Brittany , Tobin Kim , Bhatia Monica , George Diane , Garvin James , Satwani Prakash
Published: August 2017

HPC infusions have been associated with a variety of adverse events related to either patient or HPC product‐related factors. Studies documenting infusion‐related AEs in children are limited. We reviewed HPC infusion records in 354 children. Infusion‐related adverse events were classified as follows: grade 0—absent, grade I—mild, grade II—moderate, grade III—severe, grade IV—life‐threatening, and grade V—death. The percentage of patients with grade 0, I, and II‐IV AEs was as follows: 0 = 67%, I = 23.4%, and II‐V = 9.6% (one patient had fatal anaphylactic reaction to dimethyl sulfoxide). The incidence of grade II‐IV hypertension was 7.1%. There was a higher incidence of AEs with infusion of allogeneic bone marrow versus allogeneic PBSCs (47.4% vs 25.3%, P = .001). Cryopreserved products had a lower incidence of infusion‐associated AEs compared with fresh HPC products (24% vs 39.4%, P = .003). Allogeneic HPC infusion volume (>100 mL) was a significant risk factor for infusion‐associated AEs (P < .001). Patients >10 years who received autologous HPC infusions had higher risk of AEs when compared to patients <10 years (P = .01). Our study demonstrated that despite a high incidence of infusion‐associated hypertension, HPC infusion is relatively safe in children. Investigating strategies to optimize management of hypertension in the setting of HPC infusion is warranted.
T cell replete–haploidentical second hematopoietic stem cell transplantation for primary graft failure in pediatric patients with hematologic malignancies
Authors: Mochizuki Kazuhiro , Sano Hideki , Akaihata Mitsuko , Kobayashi Shogo , Waragai Tomoko , Ohara Yoshihiro , Takahashi Nobuhisa , Ito Masaki , Ikeda Kazuhiko , Ohto Hitoshi , Kikuta Atsushi
Published: August 2017

GF is one of the fatal complications of allogeneic HSCT. To rescue patients with primary GF, a second HSCT should be conducted as soon as possible, but the optimal donor source and technique have yet to be established. In this study, we retrospectively analyzed six children with hematologic malignancies who received TCR‐haploidentical second HSCT for primary GF. The median interval between the prior HSCT and the second HSCT was 37.5 days. All patients received fludarabine and ATG containing reduced‐intensity re‐conditioning before the second HSCT. All patients, except one who died early, achieved both neutrophil and Plt engraftment at a median time of 15 and 33 days, respectively. Chimerism analysis showed that all engrafted patients achieved complete donor chimerism within 3 weeks. Four patients developed acute GVHD, and three patients developed chronic GVHD. TRM occurred in two patients. Median follow‐up of the four survivors was 6.8 years, and all remained in sustained remission until the last follow‐up. These results suggested that a TCR‐haploidentical second HSCT for pediatric patients is feasible, and this approach may provide a potent option for children with primary GF.
Parent‐child coregulation of parasympathetic processes varies by social context and risk for psychopathology
Authors: Lunkenheimer Erika , Tiberio Stacey S. , Skoranski Amanda M. , Buss Kristin A. , Cole Pamela M.
Published: August 2017

The parasympathetic nervous system supports social interaction and varies in relation to psychopathology. However, we know little about parasympathetic processes from a dyadic framework, nor in early childhood when parent‐child social interactions become more complex and child psychopathology first emerges. We hypothesized that higher risk for psychopathology (maternal psychopathology symptoms and child problem behavior) would be related to weaker concordance of respiratory sinus arrhythmia (RSA) between mothers and children (M = 3½ years old; N = 47) and that these relations could vary by social contextual demands, comparing unstructured free play, semistructured cleanup, and structured teaching tasks. Multilevel coupled autoregressive models of RSA during parent‐child interactions showed overall dynamic, positive concordance in mother‐child RSA over time, but this concordance was weaker during the more structured teaching task. In contrast, higher maternal psychological aggression and child externalizing and internalizing problems were associated with weaker dyadic RSA concordance, which was weakest during unstructured free play. Higher maternal depressive symptoms were related to disrupted individual mother and child RSA but not to RSA concordance. Thus, risk for psychopathology was generally related to weaker dyadic mother‐child RSA concordance in contexts with less complex structure or demands (free play, cleanup), as compared to the structured teaching task that showed weaker RSA concordance for all dyads. Implications for the meaning and utility of the construct of parent‐child physiological coregulation are discussed.
Long‐term trends in restoration and associated land treatments in the southwestern United States
Authors: Copeland Stella M. , Munson Seth M. , Pilliod David S. , Welty Justin L. , Bradford John B. , Butterfield Bradley J.
Published: August 2017

Restoration treatments, such as revegetation with seeding or invasive species removal, have been applied on U.S. public lands for decades. Temporal trends in these management actions have not been extensively summarized previously, particularly in the southwestern United States where invasive plant species, drought, and fire have altered dryland ecosystems. We assessed long‐term (1940–2010) trends in restoration using approximately 4,000 vegetation treatments conducted on Bureau of Land Management lands across the southwestern United States. We found that since 1940, the proportions of seeding and vegetation/soil manipulation (e.g. vegetation removal or plowing) treatments have declined, while the proportions of prescribed burn and invasive species treatments have increased. Treatments in pinyon‐juniper and big sagebrush communities declined in comparison to treatments in desert scrub, creosote bush, and riparian woodland communities. Restoration‐focused treatment objectives increased relative to resource extraction objectives. Species richness and proportion of native species used in seeding treatments also increased. Inflation‐adjusted costs per area rose 750% for vegetation/soil manipulation, 600% for seeding, and 400% for prescribed burn treatments in the decades from 1981 to 2010. Seeding treatments were implemented in warmer and drier years when compared to the climate conditions of the entire study period and warmer and wetter years relative to several years before and after the treatment. These results suggest that treatments over a 70‐year period on public lands in the southwestern United States are shifting toward restoration practices that are increasingly large, expensive, and related to fire and invasive species control.
Pathophysiology of exercise intolerance in pulmonary arterial hypertension
Authors: Tran Derek L. , Lau Edmund M.T. , Celermajer David S. , Davis Glen M. , Cordina Rachael
Published: August 2017

ABSTRACT

Pulmonary arterial hypertension (PAH) is a chronic disease with poor prognosis and important exercise limitation despite the proliferation of treatment options in the last decade. Chronically increased right ventricular (RV) afterload results in right heart failure and without treatment, rapid clinical deterioration is common. Exercise intolerance is the cardinal feature of the disease impacting upon quality of life and clinical outcome. The pathophysiological mechanisms that lead to reduced exercise capacity in this population are complex with ventriculoarterial uncoupling likely to be the predominant feature. The relative contributions of additional factors that contribute to exercise limitation beyond ventriculoarterial uncoupling have not been characterized. This review addresses these factors with a focus on recent developments and uncertainties. RV maladaptation and the intricate interplay between the heart, abnormal pulmonary vascular bed and peripheral factors such as dysfunction of the respiratory and peripheral muscles are discussed in detail.
Treatment of idiopathic pulmonary fibrosis in Australia and New Zealand: A position statement from the Thoracic Society of Australia and New Zealand and the Lung Foundation Australia
Authors: Jo Helen E. , Troy Lauren K. , Keir Gregory , Chambers Daniel C. , Holland Anne , Goh Nicole , Wilsher Margaret , de Boer Sally , Moodley Yuben , Grainge Christopher , Whitford Helen , Chapman Sally , Reynolds Paul N. , Glaspole Ian , Beatson David , Jones Leonie , Hopkins Peter , Corte Tamera J.
Published: August 2017

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a fibrosing interstitial lung disease (ILD) of unknown aetiology with a median survival of only 2–5 years. It is characterized by progressive dyspnoea and worsening lung function, ultimately resulting in death.

Until recently, there were no effective therapies for IPF; however, with the publication of two landmark clinical trials in 2014, the anti‐fibrotic therapies, nintedanib and pirfenidone, have gained widespread approval.

This position paper aims to highlight the current evidence for the treatment of IPF, with particular application to the Australian and New Zealand population. We also consider areas in which evidence is currently lacking, especially with regard to the broader IPF severity spectrum and treatment of co‐morbid conditions. The utility of non‐pharmacological therapies including pulmonary rehabilitation, oxygen as well as symptom management thought to be important in the holistic care of IPF patients are also discussed.
Asthma prescribing: Where are we headed?
Authors: Beasley Richard , Hardy Jo , Hancox Robert
Published: August 2017

See related Article
Optimal Inspection of Imports to Prevent Invasive Pest Introduction
Authors: Chen Cuicui , Epanchin‐Niell Rebecca S. , Haight Robert G.
Published: August 2017

The United States imports more than 1 billion live plants annually—an important and growing pathway for introduction of damaging nonnative invertebrates and pathogens. Inspection of imports is one safeguard for reducing pest introductions, but capacity constraints limit inspection effort. We develop an optimal sampling strategy to minimize the costs of pest introductions from trade by posing inspection as an acceptance sampling problem that incorporates key features of the decision context, including (i) simultaneous inspection of many heterogeneous lots, (ii) a lot‐specific sampling effort, (iii) a budget constraint that limits total inspection effort, (iv) inspection error, and (v) an objective of minimizing cost from accepted defective units. We derive a formula for expected number of accepted infested units (expected slippage) given lot size, sample size, infestation rate, and detection rate, and we formulate and analyze the inspector's optimization problem of allocating a sampling budget among incoming lots to minimize the cost of slippage. We conduct an empirical analysis of live plant inspection, including estimation of plant infestation rates from historical data, and find that inspections optimally target the largest lots with the highest plant infestation rates, leaving some lots unsampled. We also consider that USDA‐APHIS, which administers inspections, may want to continue inspecting all lots at a baseline level; we find that allocating any additional capacity, beyond a comprehensive baseline inspection, to the largest lots with the highest infestation rates allows inspectors to meet the dual goals of minimizing the costs of slippage and maintaining baseline sampling without substantial compromise.
Impact of Cooking Procedures and Storage Practices at Home on Consumer Exposure to Listeria Monocytogenes and Salmonella Due to the Consumption of Pork Meat
Authors: De Cesare Alessandra , Doménech Eva , Comin Damiano , Meluzzi Adele , Manfreda Gerardo
Published: August 2017

The objective of this research was to analyze the impact of different cooking procedures (i.e., gas hob and traditional static oven) and levels of cooking (i.e., rare, medium, and well‐done) on inactivation of Listeria monocytogenes and Salmonella in pork loin chops. Moreover, the consumer's exposure to both microorganisms after simulation of meat leftover storage at home was assessed. The results showed that well‐done cooking in a static oven was the only treatment able to inactivate the tested pathogens. The other cooking combinations allowed to reach in the product temperatures always ≥73.6 °C, decreasing both pathogens between 6 log10 cfu/g and 7 log10 cfu/g. However, according to simulation results, the few cells surviving cooking treatments can multiply during storage by consumers up to 1 log10 cfu/g, with probabilities of 0.059 (gas hob) and 0.035 (static oven) for L. monocytogenes and 0.049 (gas hob) and 0.031 (static oven) for Salmonella. The key factors affecting consumer exposure in relation to storage practices were probability of pathogen occurrence after cooking, doneness degree, time of storage, and time of storage at room temperature. The results of this study can be combined with prevalence data and dose–response models in risk assessment models and included in guidelines for consumers on practices to be followed to manage cooking of pork meat at home.
Estimating Onset Time from Longitudinal and Cross-Sectional Data with an Application to Estimating Gestational Age from Longitudinal Maternal Anthropometry During Pregnancy and Neonatal Anthropometry at Birth
Authors: Ortega-Villa Ana Maria , Grantz Katherine L. , Albert Paul S.
Published: August 2017

Determining the date of conception is important for estimating gestational age and monitoring whether the fetus and mother are on track in their development and pregnancy. Various methods based on ultrasound have been proposed for dating a pregnancy in high resource countries. However, such techniques may not be available in under-resourced countries. We develop a shared random-parameter model for estimating the date of conception by using longitudinal assessment of multiple maternal anthropometry and cross-sectional neonatal anthropometry. The methodology is evaluated with a training–test set paradigm as well as with simulations to examine the robustness of the method to model misspecification. We illustrate this new methodology with data from the National Institute of Child Health and Development fetal growth studies.
Pfeiffer syndrome: oral healthcare management and description of new dental findings in a craniosynostosis
Authors: Hassona Yazan , Al‐Hadidi Abeer , Ghlassi Thaer Abu , Dali Hanin El , Scully Crispian
Published: August 2017

Pfeiffer syndrome is a rare fibroblast growth factor receptor‐related craniosynostosis with variable clinical presentations. We describe new dental findings of hypodontia, microdontia, dilacerations, and radicular dentin dysplasia in a 19‐year‐old girl, and discuss the oral health management.
Identification of a new HLA‐B*51:226 allele in a Chinese bone marrow‐related donor
Authors: Li Y.‐N. , Feng Z.‐H. , Ma W.‐H. , Wang H.‐Y.
Published: August 2017

HLA‐B*51:226 was initially identified in a Chinese‐related donor for stem cell transplantation.
Yeast and other lower eukaryotic organisms for studies of Vps13 proteins in health and disease
Authors: Rzepnikowska Weronika , Flis Krzysztof , Muñoz‐Braceras Sandra , Menezes Regina , Escalante Ricardo , Zoladek Teresa
Published: August 2017

Human Vps13 proteins are associated with several diseases, including the neurodegenerative disorder Chorea‐acanthocytosis (ChAc), yet the biology of these proteins is still poorly understood. Studies in Saccharomyces cerevisiae, Dictyostelium discoideum, Tetrahymena thermophila and Drosophila melanogaster point to the involvement of Vps13 in cytoskeleton organization, vesicular trafficking, autophagy, phagocytosis, endocytosis, proteostasis, sporulation and mitochondrial functioning. Recent findings show that yeast Vps13 binds to phosphatidylinositol lipids via 4 different regions and functions at membrane contact sites, enlarging the list of Vps13 functions. This review describes the great potential of simple eukaryotes to decipher disease mechanisms in higher organisms and highlights novel insights into the pathological role of Vps13 towards ChAc.
Enucleation or exenteration in two dogs with previous parotid duct transposition: parotid duct ligation versus reverse parotid duct transposition
Authors: Young Whitney M. , Betbeze Caroline M. , Fisher Stephen C. , Boulay James P.
Published: August 2017

Two dogs with previous parotid duct transpositions presented with unrelated ocular disease. In both cases, ophthalmic examination revealed the need for enucleation or exenteration. In case 1, systemic coccidioidomycosis was diagnosed with panuveitis and secondary glaucoma of the left eye. In this case, the parotid duct was ligated at the time of enucleation to stop salivary secretions. This dog encountered morbidity in the form of a sialocele that did not resolve for 11 months. In case 2, ultrasound and computed tomography revealed a discrete mass within the left medial orbit that was suspected to arise from the nictitating membrane. A combination of exenteration and parotid duct transposition reversal was performed to avoid morbidity associated with ligation of the parotid duct. The dog encountered no complications from this novel procedure. This case report represents the first report of re‐routing a transposed parotid duct from the ventral conjunctival sac back to the mouth at the time of enucleation or exenteration in the dog.
Tear fluid collection in dogs and cats using ophthalmic sponges
Authors: Sebbag Lionel , Harrington Danielle M. , Mochel Jonathan P.
Published: August 2017

Objective

To compare the use of two ophthalmic sponges for tear collection in dogs and cats.

Animals studied

Ten healthy dogs and 10 healthy cats.

Procedures

A strip (4 × 10 mm) of either cellulose or polyvinyl acetal (PVA) sponge was inserted into the ventral fornix of each eye for either 15, 30, or 60 s. The wetted strip was placed into a 0.2‐mL tube that was first punctured at its bottom. Tears were eluted through the drainage hole into a 1.5‐mL tube via centrifugation. Tear volume absorbed (VA) and tear volume recovered (VR) were calculated as the difference of the post‐ and precollection weight of the 0.2‐mL tube and 1.5‐mL tube, respectively. Recovery ratio (RR) was determined as the ratio between VR and VA.

Results

Ophthalmic sponges were well tolerated by all subjects. In dogs and cats, median (95% range) VA, VR, and RR were as follows: 44 μL (11–106 μL) and 16 μL (2–43 μL); 27 μL (1–84 μL) and 6 μL (0–29 μL); 64% (7–91%) and 35% (0–86%), respectively. PVA sponges achieved significantly greater VR in cats and RR in both species. All parameters were significantly greater with a collection time of 60 vs. 30 and 15 s. Body weight was associated with VA and VR in dogs but not cats.

Conclusions

Polyvinyl acetal is better than cellulose for tear collection given its superior recovery. Ophthalmic sponges could facilitate routine analysis of tear fluid in dogs and cats, although further studies are needed to evaluate the quality of tears obtained with this method.
The Relations between Scientific Epistemological Beliefs and Goal Orientations of Pre-Service Teachers
Authors: Kaya Gamze Inan
Published: August 2017

The purpose of this study was to investigate the relations between pre-service teachers’ scientific epistemological beliefs and goal orientations in 2X2 framework. Scientific epistemological beliefs are domain-specific views of people about nature and acquisition of scientific knowledge, how scientific knowledge is produced, how reliable and valid that knowledge is and how it is shared. Participants were 484 pre-service teachers and 284 (59 %) of them were attending to education faculty and 198 (41 %) of them were graduates who attended teaching certificate program. Scientific epistemological beliefs predicted both mastery (approach-avoidance) and performance (approach-avoidance) goal orientations. The participants who viewed science from a more traditional perspective were more likely to adopt mastery-approach, mastery-avoidance, performance-approach and performance-avoidance goals, respectively. Moreover, the participants who attended and successfully completed a scientific research methods course formerly had less traditional scientific epistemological beliefs than the participants who had not attended to such a course previously. Theoretical and educational implications of the findings were discussed.
Implementability of Benchmarking (Comparative) Technique in Sports Enterprises (Sample Elazig)
Authors: Altungul Oguzhan , Demirag Reşat
Published: August 2017

Increasing competition in domestic and foreign markets in the globalizing world and increasing quality expectations of customers have led enterprises to develop and implement a range of different quality considerations in order to remain competitive or to increase competitive power. One of the most important of these approaches is called benchmarking in the international literature, which is called "the best of the best" in businesses.The purpose of this study was to evaluate the Benchmarking approach of management and science concepts of sports enterprises operating in Elazıg.The universe of the research is the sports enterprises in Turkey and the sample is the sports enterprises in Elazıg province. The research was evaluated as collecting and analyzing benchmarking information.In the qualitative survey, sports and social facilities benchmarking services, financial data collection tool and sports facility participants questionnaire were applied. The questionnaire developed by Peter Taylor was translated into Turkish and validated and credible, and Cronbach alpha value α = 0, 816.A significant difference was observed when participants' participation in sports facilities in Elazıg was examined in terms of place of birth according to the AnovaTukey test.As a result; Although there was a significant difference between the expectations of the participants coming to sports facilities operating in Elazıg province (p <0, 05), there was no significant difference between their satisfaction (p> 0,05).Compared to the sports facilities in Elazıg, it can be considered that there are many deficiencies in all sports facilities and that no professional management is used.
Mars Water-Ice Clouds and Precipitation
Authors: Whiteway J. A. , Komguem L. , Dickinson C. , Cook C. , Illnicki M. , Seabrook J. , Popovici V. , Duck T. J. , Davy R. , Taylor P. A. , Pathak J. , Fisher D. , Carswell A. I. , Daly M. , Hipkin V. , Zent A. P. , Hecht M. H. , Wood S. E. , Tamppari L. K. , Renno N. , Moores J. E. , Lemmon M. T. , Daerden F. , Smith P. H.
Published: August 2017

Phoenix Ascending

The Phoenix mission landed on Mars in March 2008 with the goal of studying the ice-rich soil of the planet's northern arctic region. Phoenix included a robotic arm, with a camera attached to it, with the capacity to excavate through the soil to the ice layer beneath it, scoop up soil and water ice samples, and deliver them to a combination of other instruments—including a wet chemistry lab and a high-temperature oven combined with a mass spectrometer—for chemical and geological analysis. Using this setup,

Smith
et al.

(p.
58
) found a layer of ice at depths of 5 to 15 centimeters,

Boynton
et al.

(p.
61
) found evidence for the presence of calcium carbonate in the soil, and

Hecht
et al.

(p.
64
) found that most of the soluble chlorine at the surface is in the form of perchlorate. Together these results suggest that the soil at the Phoenix landing site must have suffered alteration through the action of liquid water in geologically the recent past. The analysis revealed an alkaline environment, in contrast to that found by the Mars Exploration Rovers, indicating that many different environments have existed on Mars. Phoenix also carried a lidar, an instrument that sends laser light upward into the atmosphere and detects the light scattered back by clouds and dust. An analysis of the data by

Whiteway
et al.

(p.
68
) showed that clouds of ice crystals that precipitated back to the surface formed on a daily basis, providing a mechanism to place ice at the surface.
Surge in right whale deaths raises alarms
Authors: Stokstad Erik
Published: August 2017

Researchers seek to understand why whales are showing up in high-risk waters in
Canada
The organoid architect
Authors: Sinha Gunjan
Published: August 2017

Hans Clevers pioneered lab-built mini-organs that can serve as models of
disease
Invention Ambassadors take on society'schallenges
Authors: Jarvis Michaela
Published: August 2017

Eight inventors come together to help bolster problem-solving innovation
Actin protects mammalian eggs against chromosome segregation errors
Authors: Mogessie Binyam , Schuh Melina
Published: August 2017

Actin helps chromosome segregation in eggs

Spindle microtubules are well known to orchestrate the segregation of chromosomes during egg development. But the other major cytoskeletal component, actin, has not been thought to play a role in this process. Mogessie and Schuh examined how chromosomes are segregated in mammalian cells (see the Perspective by Maiato and Ferrás). Instead of using an entirely microtubule-dependent mechanism, mammalian oocytes use a second spindle that is made of F-actin to segregate their chromosomes correctly. Actin associated with the spindle bundles microtubules into functional kinetochore fibers, the key structures that drive chromosome segregation. Increasing or decreasing the number of actin filaments in the spindle causes an imbalance in kinetochore fiber bundling, which results in chromosome segregation errors and aneuploidy, a frequent cause of miscarriage and Down syndrome in humans.

Science
, this issue p.
eaal1647
; see also p.
756
Eye patches: Protein assembly of index-gradient squid lenses
Authors: Cai J. , Townsend J. P. , Dodson T. C. , Heiney P. A. , Sweeney A. M.
Published: August 2017

Squid lenses beat spherical aberration

When light rays pass through a curved lens, greater refraction at the edges can distort the resulting image. This problem can be overcome if the refractive index of the lens is varied according to the curvature. Cai
et al.
show that the lenses of squid eyes have an internal structure containing a set of globular proteins that form a gradient of colloidal particles to counter spherical aberration (see the Perspective by Madl). Thus, the evolutionary process has used the principles of patchy colloid theory to construct a self-assembling, complex optical device.

Science
, this issue p.
564
; see also p.
546
Comment on “Permanent human occupation of the central Tibetan Plateau in the early Holocene”
Authors: Zhang Dongju , Zhang Naimeng , Wang Jian , Ha Bibu , Dong Guanghui , Chen Fahu
Published: August 2017

Meyer
et al
. (Reports, 6 January 2017, p. 64) claim that permanent human occupation of the central Tibetan Plateau started in the early Holocene without the support of an agropastoral economy. By careful examination, we find that neither the archaeological evidence nor the travel cost modeling provided by Meyer
et al
. could support the permanent human occupation assertion.
Response to Comment on “Permanent human occupation of the central Tibetan Plateau in the early Holocene”
Authors: Haas W. R. , Aldenderfer M. S. , Meyer M. C.
Published: August 2017

Zhang
et al
. contest that Chusang was part of an annual mobility round that “more likely” included seasonal use of high-elevation environments than permanent use. We show that their probabilistic statement hinges on indefensible claims about hunter-gatherer mobility. In the context of quantitative data from hunter-gatherer ethnography, our travel model shows that seasonal-use models are highly unlikely to explain Chusang.
The dual frontier: Patented inventions and prior scientific advance
Authors: Ahmadpoor Mohammad , Jones Benjamin F.
Published: August 2017

Picking up a patent

What is the relationship between patents and scientific advances? Ahmadpoor and Jones devised a metric for the “distance” between patentable inventions and prior research to study this question. They analyzed the relationship between 4.8 million U.S. patents and 32 million research articles. Universities tended to cite their own research directly in their patents (in other words, a distance of 1), but the distance was greater for companies, suggesting that companies may rely on outsiders for their foundational research. The distance varied by discipline, with nanotechnology and computer science having the shortest distances between published research and patents.

Science
, this issue p.
583
Comment on “Observation of the Wigner-Huntington transition to metallic hydrogen”
Authors: Goncharov Alexander F. , Struzhkin Viktor V.
Published: August 2017

Dias and Silvera (Research Article, 17 February 2017, p. 715) report on the observation of the Wigner-Huntington transition to metallic hydrogen at 495 gigapascals at 5.5 and 83 kelvin. Here, we show that the claim of metallic behavior is not supported by the presented data, which are scarce, contradictory, and do not prove the presence of hydrogen in the high-pressure cavity.
Microbiota-activated PPAR-γ signaling inhibits dysbiotic Enterobacteriaceae expansion
Authors: Byndloss Mariana X. , Olsan Erin E. , Rivera-Chávez Fabian , Tiffany Connor R. , Cevallos Stephanie A. , Lokken Kristen L. , Torres Teresa P. , Byndloss Austin J. , Faber Franziska , Gao Yandong , Litvak Yael , Lopez Christopher A. , Xu Gege , Napoli Eleonora , Giulivi Cecilia , Tsolis Renée M. , Revzin Alexander , Lebrilla Carlito B. , Bäumler Andreas J.
Published: August 2017

Healthy guts exclude oxygen

Normally, the lumen of the colon lacks oxygen. Fastidiously anaerobic butyrate-producing bacteria thrive in the colon; by ablating these organisms, antibiotic treatment removes butyrate. Byndloss
et al.
discovered that loss of butyrate deranges metabolic signaling in gut cells (see the Perspective by Cani). This induces nitric oxidase to generate nitrate in the lumen and disables β-oxidation in epithelial cells that would otherwise mop up stray oxygen before it enters the colon. Simultaneously, regulatory T cells retreat, and inflammation is unchecked, which contributes yet more oxygen species to the colon. Then, facultative aerobic pathogens, such as
Escherichia coli
and
Salmonella enterica
, can take advantage of the altered environment and outgrow any antibiotic-crippled and benign anaerobes.

Science
, this issue p.
570
; see also p.
548
Structure and assembly mechanism of plant C
2
S
2
M
2
-type PSII-LHCII supercomplex
Authors: Su Xiaodong , Ma Jun , Wei Xuepeng , Cao Peng , Zhu Dongjie , Chang Wenrui , Liu Zhenfeng , Zhang Xinzheng , Li Mei
Published: August 2017

Adapting to the right light

In plants, photosystem II is the first protein complex in the machinery that converts sunlight into chemical energy. It comprises antennae complexes (LHCIIs), which collect the light energy, and a dimeric core that contains the reaction center where water is split into oxygen and protons. Su
et al.
report cryo-electron microscopy structures of a supercomplex consisting of the dimeric core, two strongly bound LHCIIs, and two moderately bound LHCIIs (see the Perspective by Croce and van Amerongen). Under high-light conditions, the moderately bound LHCIIs might detach to down-regulate the efficiency of light harvesting and prevent damage.

Science
, this issue p.
815
; see also p.
752
A unified continental thickness from seismology and diamonds suggests a melt-defined plate
Authors: Tharimena Saikiran , Rychert Catherine , Harmon Nicholas
Published: August 2017

A coherent depth for continental plates

The thickness of the continental portion of Earth's cold and rigid surface plates is a source of debate. Tharimena
et al.
analyzed a specific type of seismic signal called SS precursors to provide a robust estimate of plate thickness under the continents (see the Perspective by Savage). The values range from 130 to 190 km, which lines up well with the depth where diamonds are stable—an independent line of evidence for the depth of continents.

Science
, this issue p.
580
; see also p.
549
Step up for quality research
Authors: Schrag Naomi J. , Purdy G. Michael
Published: August 2017

In response to calls for change from within and outside the scientific community, funding agencies, journals, and professional societies are developing new requirements to promote reproducibility and integrity in research. Amid this activity, the voices of academic institutions—both their leadership and rank-and-file faculty—have largely been quiet. Yet journals, societies, and funding agencies are not in the laboratory, clinic, or field. They do not analyze data, write manuscripts, or prepare figures. Institutions that comprise the global academic community can do more to help their researchers produce the highest-quality results. The three areas of actions, described below, echo points highlighted in the recent U.S. National Academies of Sciences, Engineering, and Medicine report,
Fostering Integrity in Research
, as well as at the 2017 World Conference on Research Integrity in May.
Two areas for familiar face recognition in the primate brain
Authors: Landi Sofia M. , Freiwald Winrich A.
Published: August 2017

I've seen this face before

We have known for some time that there is a network of brain regions for face recognition. However, how and where face familiarity is encoded has been elusive for decades. Landi and Freiwald performed brain imaging in macaques and identified two areas specifically involved in recognizing familiar faces. These two areas showed a nonlinear response as blurred faces gradually became visible, rapidly becoming active when the faces of familiar monkeys became recognizable.

Science, this issue p.591
Comment on “Observation of the Wigner-Huntington transition to metallic hydrogen”
Authors: Liu Xiao-Di , Dalladay-Simpson Philip , Howie Ross T. , Li Bing , Gregoryanz Eugene
Published: August 2017

Dias and Silvera (Research Article, 17 February 2017, p. 715) claim the observation of the Wigner-Huntington transition to metallic hydrogen at 495 gigapascals. We show that neither the claims of the record pressure nor the phase transition to a metallic state are supported by data and that the data contradict the authors’ own unconfirmed previous results.
Single-cell methylomes identify neuronal subtypes and regulatory elements in mammalian cortex
Authors: Luo Chongyuan , Keown Christopher L. , Kurihara Laurie , Zhou Jingtian , He Yupeng , Li Junhao , Castanon Rosa , Lucero Jacinta , Nery Joseph R. , Sandoval Justin P. , Bui Brian , Sejnowski Terrence J. , Harkins Timothy T. , Mukamel Eran A. , Behrens M. Margarita , Ecker Joseph R.
Published: August 2017

Methylation and the single neuronal cell

The presence or absence of methylation on chromosomal DNA can drive or repress gene expression. Now, a comprehensive map of methylation variation in neuronal cell populations, including a between-species comparison, illustrates how epigenetic diversity plays important roles in neuronal development. Luo
et al.
examined how DNA methylation is both similar and different within neurons at the single-nucleus level in humans and mice. They identified 16 mouse and 21 human neuronal clusters, with greater complexity of excitatory neurons in deep brain layers than in superficial layers.

Science
, this issue p.
600
U.S. attitudes on human genome editing
Authors: Scheufele Dietram A. , Xenos Michael A. , Howell Emily L. , Rose Kathleen M. , Brossard Dominique , Hardy Bruce W.
Published: August 2017

Although views on human genome editing differ, all want public engagement
Seasonal cycling in the gut microbiome of the Hadza hunter-gatherers of Tanzania
Authors: Smits Samuel A. , Leach Jeff , Sonnenburg Erica D. , Gonzalez Carlos G. , Lichtman Joshua S. , Reid Gregor , Knight Rob , Manjurano Alphaxard , Changalucha John , Elias Joshua E. , Dominguez-Bello Maria Gloria , Sonnenburg Justin L.
Published: August 2017

Seasonal diets, seasonal microbiota

Among the Hadza of western Tanzania, a few hundred people still live in small groups as hunter-gatherers, reliant solely on the wild environment for food. Smits
et al.
found that the microbiota of these people reflects the seasonal availability of different types of food (see the Perspective by Peddada). Between seasons, striking differences were observed in their gut microbial communities, with some taxa apparently disappearing, only to reappear when the seasons turned. Further comparison of the Hadza microbiota with that of diverse urbanized peoples revealed distinctly different patterns of microbial community composition.

Science
, this issue p.
802
; see also p.
754
American movers and shakers
The Great Quake: How the Biggest Earthquake in North America Changed Our Understanding of the Planet
Henry Fountain
Crown, 2017. 296 pp.
Quakeland: On the Road to America's Next Devastating Earthquake
Kathryn Miles
Dutton, 2017. 368 pp.
Authors: Murnane Richard J.
Published: August 2017

A pair of books explores past and future U.S. earthquakes
Einstein's magnum opus
The Formative Years of Relativity
Hanoch Gutfreund and Jürgen Renn
Princeton University Press, 2017. 430 pp.
Authors: Robinson Andrew
Published: August 2017

An insightful tome recounts the heady early days of general relativity
Patchy proteins form a perfect lens
Authors: Madl Tobias
Published: August 2017

Squid lenses are formed by a protein gel of varying density
Gut cell metabolism shapes the microbiome
Authors: Cani Patrice D.
Published: August 2017

The metabolism of colonocytes determines the type of microbes that thrive in the gut
Intracellular signaling in CRISPR-Cas defense
Authors: Amitai Gil , Sorek Rotem
Published: August 2017

New molecular communication in type III CRISPR-Cas systems has been identified
Seasonal change in the gut
Authors: Peddada Shyamal
Published: August 2017

The gut microbiome of Hadza hunter-gatherers changes with the season
Empowering science advice
Authors: Turekian Vaughan
Published: August 2017

President Trump and his administration's leaders should learn from history and embrace science advice as critical to U.S. national interests. The nascent administration has yet to identify a science and technology (S&T) adviser to the president, a central figure in fortifying American preeminence in science, technology, and innovation. But the president's science adviser is just one member of a traditionally robust effort to ensure that U.S. policies leverage the nation's signature S&T strength. In today's world, S&T issues are international in scale and scope.
Abdominal tuberculosis and spontaneous miscarriage
Authors: Islam Baharul , Islam Nikita , Mehkri Hudaa , AlQaasimi Mai
Published: August 2017

We present a case report of a 23-year-old Pakistani woman who had a second trimester spontaneous miscarriage while visiting her family in the Kingdom of Saudi Arabia. A dilatation and curettage (D&C) was done after the miscarriage. She developed sepsis and acute respiratory distress syndrome, requiring intensive care unit admission a few days after the D&C. An exploratory laparotomy was done and she was found to have a pelvic abscess. Despite adequate broad spectrum antimicrobial cover, she continued to drain a copious amount of serous fluid from the peritoneal cavity, with persistent fever and a stiff lung with difficult weaning off mechanical ventilation. Tuberculosis PCR of the peritoneal fluid came back positive. A histological finding of necrotising granuloma from the postoperative omental specimen and a positive culture from the ascitic fluid confirmed the diagnosis ofMycobacterium tuberculosis. Antituberculous treatment was started and she made a speedy recovery.
Association between maternal vitamin D deficiency and small for gestational age: evidence from a meta-analysis of prospective cohort studies
Authors: Chen Yao , Zhu Beibei , Wu Xiaoyan , Li Si , Tao Fangbiao
Published: August 2017

Objective

To determine whether maternal vitamin D deficiency during pregnancy is associated with small for gestational age (SGA).

Methods

A comprehensive literature search of PubMed, the Cochrane Library, Embase, and the Elsevier ScienceDirect library was conducted to identify relevant articles reporting prospective cohort studies in English, with the last report included published in February 2017. Pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were used to evaluate the correlation in a random effects model.

Results

A total of 13 cohort studies were included in this meta-analysis with a sample of 28 285 individuals from seven countries. The pooled overall OR for babies born SGA was 1.588 (95%CI 1.138 to 2.216; p<0.01) for women with vitamin D deficiency. The prevalence of vitamin D deficiency during pregnancy varied from 13.2% to 77.3%. Subgroup analyses identified no significant differences in the association between vitamin D deficiency and SGA based on study quality, gestational week during which blood sampling was performed, cut-off vitamin D levels, sample size, adjustment for critical confounders and method for measuring vitamin D.

Conclusion

This meta-analysis suggests that vitamin D deficiency is associated with an increased risk of SGA.
Spatial and temporal distributions of the late Mesozoic volcanic successions and their controlling effects on the Changling fault depression of the Songliao Basin, northeast China
Authors: Chang Wenbo , Shan Xuanlong , Yi Jian , Du Tiantian , Qu Yue
Published: August 2017

Volcanic successions, including their spatial, temporal, tectonic, and geochemical attributes, were identified based on well data, 2D and 3D seismic data, U–Pb isotopic ages, and major and trace element data from the Changling fault depression of the Songliao Basin in northeastern China. Three eruption cycles developed in the Changling fault depression: K1h (Huoshiling Formation) (124–118 Ma), K1yc1 (first member of the Yingcheng Formation) (115–106 Ma), and K1yc3 (third member of the Yingcheng Formation) (106–102 Ma). These three eruption cycles comprised seven eruption stages. The volcanic successions in every eruption cycle were bimodal and evolved from basic to acidic. The magma of the basic and intermediate rocks in these cycles was derived from partial melting of the asthenosphere. In K1yc1 and K1yc3, partial melting of the newly formed basic rocks in the lower crust formed the high-SiO2 acidic magma. In addition, fractional crystallization of basic magma formed the small-scale intermediate–acidic magma. In K1h, the most likely origin of the acidic magma was fractional crystallization of basic magma. During the early stage of the fault depression, the volcanic rocks of K1h were controlled primarily by the boundary fault activity. In K1yc1 and K1yc3, basic–intermediate rocks were distributed widely along syngenetic faults, and acidic rocks were concentrated in areas where the syngenetic faults had their largest amplitudes. Multiple cycles and stages of the volcanic successions were controlled by magmatic evolution, and the spatial distribution was controlled by basin tectonics.
Rectifying characteristics and tunable magnetoresistance in heterojunctions of La0.9Hf0.1MnO3/0.05 wt.% Nb-doped SrTiO3
Authors: Qi Yaping , Liu Xiangbo , Ni Hao , Zheng Ming , Chen Liping , Wang Lin , Jiang Yucheng , Zhao Meng , Gao Ju
Published: August 2017

La[Formula: see text]Hf[Formula: see text]MnO3 films were grown on 0.05 wt.% Nb-doped SrTiO3 substrates by pulsed laser deposition. X-ray diffraction measurements demonstrated that our samples were of good epitaxy and single-crystal. The temperature-dependent resistance has been investigated. It was observed that the as-grown film of La[Formula: see text]Hf[Formula: see text]MnO3 exhibited a typical paramagnetic-ferromagnetic transition. Heterojunctions of La[Formula: see text]Hf[Formula: see text]MnO3/0.05 wt.% Nb-doped SrTiO3 exhibited-asymmetric current–voltage characteristics and a remarkable temperature-dependent rectifying behavior in a wide temperature range (from 40 K to 300 K). And the most remarkable observation of this work is the existence of a crossover from positive to negative magnetoresistance in the La[Formula: see text]Hf[Formula: see text]MnO3/0.05 wt.% Nb-doped SrTiO3 heterojunction as the temperature decreases. A temperature-dependent magnetoresistance was studied as well. The rectifying characteristics and tunable magnetoresistance of these heterojunctions may be attributed to band structure of La[Formula: see text]Hf[Formula: see text]MnO3/0.05 wt.% Nb-doped SrTiO3 heterojunction.