bluuebunny/crossref_metadata_2025 huggingface dataset:
When natural selection gives gene function the cold shoulder
Authors: Cutter Asher D. , Jovelin Richard
Published: September 2015

It is tempting to invoke organismal selection as perpetually optimizing the function of any given gene. However, natural selection can drive genic functional change without improvement of biochemical activity, even to the extinction of gene activity. Detrimental mutations can creep in owing to linkage with other selectively favored loci. Selection can promote functional degradation, irrespective of genetic drift, when adaptation occurs by loss of gene function. Even stabilizing selection on a trait can lead to divergence of the underlying molecular constituents. Selfish genetic elements can also proliferate independent of any functional benefits to the host genome. Here we review the logic and evidence for these diverse processes acting in genome evolution. This collection of distinct evolutionary phenomena – while operating through easily understandable mechanisms – all contribute to the seemingly counterintuitive notion that maintenance or improvement of a gene's biochemical function sometimes do not determine its evolutionary fate.
Syncope and cardiac arrest during strenuous exercise associated with a novel mutation in LQTS1
Authors: Sandhu Amneet , Krantz Mori J. , Taylor Matthew , Aleong Ryan G. , Stichman Jennifer , Schuller Joseph L.
Published: September 2015

Key Clinical Message

Exercise‐induced syncope should alert clinicians to the possibility of LQTS and must be distinguished from other malignant causes of syncope such as hypertrophic cardiomyopathy, catecholaminergic ventricular tachycardia, and arrhythmogenic right ventricular cardiomyopathy. Emerging genotype–phenotype links have connected mutations resulting in LQTS with risk of developing atrial fibrillation and cardiomyopathy.
Can stapedius reflex testing objectively measure muscle function in Pompe patients?
Authors: Hilz Max J. , Hoppe Ulrich , Moeller Sebastian , Wang Ruihao , Koehn Julia
Published: September 2015

Key Clinical Message

We assessed the value of stapedius reflex testing as an objective measurement of striated muscle function in four patients with Pompe disease. Common tests of disease severity and efficacy of enzyme replacement therapy (ERT) yield highly variable results that depend on patient cooperation and day‐to‐day performance, whereas stapedius reflex thresholds improved in seven of eight ears after 2 years of ERT.
Structural Studies on Porphyrin–PNA Conjugates in Parallel PNA:PNA Duplexes: Effect of Stacking Interactions on Helicity
Authors: Accetta Alessandro , Petrovic Ana G. , Marchelli Rosangela , Berova Nina , Corradini Roberto
Published: September 2015

Parallel PNA:PNA duplexes were synthesized and conjugated with meso‐tris(pyridyl)phenylporphyrin carboxylic acid at the N‐terminus. The introduction of one porphyrin unit was shown to affect slightly the stability of the PNA:PNA parallel duplex, whereas the presence of two porphyrin units at the same end resulted in a dramatic increase of the melting temperature, accompanied by hysteresis between melting and cooling curves. The circular dichroism (CD) profile of the Soret band and fluorescence quenching strongly support the occurrence of a face‐to‐face interaction between the two porphyrin units. Introduction of a L‐lysine residue at the C‐terminal of one strand of the parallel duplex induced a left‐handed helical structure in the PNA:PNA duplex if the latter contains only one or no porphyrin moiety. The left‐handed helicity was revealed by nucleobase CD profile at 240–280 nm and by the induced‐CD observed in the presence of the DiSC2(5) cyanine dye at ~500–550 nm. Surprisingly, the presence of two porphyrin units led to the disappearance of the nucleobase CD signal and the absence of CD exciton coupling within the Soret band region. In addition, a dramatic decrease of induced CD of DiSC2(5) was observed. These results are in agreement with a model where the porphyrin–porphyrin interactions cause partial loss of chirality of the PNA:PNA parallel duplex, forcing it to adopt a ladder‐like conformation. Chirality 27:864–874, 2015. © 2015 Wiley Periodicals, Inc.
Shortness of Breath During Pregnancy: Could a Cardiac Factor Be Involved?
Authors: Goland Sorel , Perelman Sharon , Asalih Nardin , Shimoni Sara , Walfish Osnat , Hallak Mordechai , Hagay Zion , George Jacob , Shotan Avraham , Blondheim David S.
Published: September 2015

Background

Shortness of breath (SOB) is common among healthy women with normal pregnancies. However, when no overt cardiac or extra cardiac etiology is found, a subtle cardiac source must be excluded.

Hypothesis

Pregnancy may induce or unmask myocardial dysfunction that may cause SOB.

Methods

Healthy pregnant women with significant SOB were recruited for this study. We performed a comprehensive echocardiographic assessment including tissue Doppler imaging (TDI) and 2‐ dimensional strain imaging (2DS). The echocardiographic data obtained were compared with that of a control group of pregnant women without SOB.

Results

Thirty pregnant women with SOB were enrolled in the study (age, 31.8 ± 4.9 years, and gestation, 38.2 ± 2.8 weeks) for whom no overt etiology for SOB was detected. Patients with SOB compared with controls had thicker hearts (septum: 10.1 ± 1.1 vs 8.9 ± 0.9 mm; P < 0.001; posterior wall: 9.4 ± 1.1 vs 8.9 ± 0.9 mm; P < 0.01), shorter E‐wave deceleration time (158.0 ± 50.1 vs 187.1 ± 37.6 msec; P = 0.01), and higher pulmonary artery pressure (26.8 ± 6.2 vs 19.0 ± 6.5 mm Hg, P < 0.01). Women with SOB tended to have a lower S' velocity TDI (P = 0.05) and a trend toward increased torsion on 2DS (P = 0.09).

Conclusions

Significant SOB during otherwise normal pregnancy is associated with significant echocardiographic findings that may suggest a subtle cardiac involvement. Further investigation is necessary to verify such an association, which may have therapeutic implications for treating SOB of pregnancy.
CD10, BCL6, and MUM1 expression in diffuse large B‐cell lymphoma on FNA samples
Authors: Cozzolino Immacolata , Varone Valeria , Picardi Marco , Baldi Carlo , Memoli Domenico , Ciancia Giuseppe , Selleri Carmine , De Rosa Gaetano , Vetrani Antonio , Zeppa Pio
Published: September 2015

BACKGROUND

Gene expression profiling has divided diffuse large B‐cell lymphoma (DLBCL) into 2 main subgroups: germinal center B (GCB) and non‐GCB type. This classification is reproducible by immunohistochemistry using specific antibodies such as CD10, B‐cell lymphoma 6 (BCL6), and multiple myeloma oncogene 1 (MUM1). Fine‐needle aspiration (FNA) plays an important role in the diagnosis of non‐Hodgkin lymphoma, and in some cases FNA may be the only available pathological specimen. The objectives of the current study were to evaluate CD10, BCL6, and MUM1 immunostaining on FNA samples by testing the CD10, BCL6, and MUM1 algorithm on both FNA cell blocks (CB) and conventional smears (CS), evaluating differences in CB and CS immunocytochemical (ICC) performance, and comparing results with histological data.

METHODS

Thirty‐eight consecutive DLBCL cases diagnosed by FNA were studied. Additional passes were used to prepare CB in 22 cases and CS in 16 cases; the corresponding sections and smears were immunostained using CD10, BCL6, and MUM1 in all cases. The data obtained were compared with histological immunostaining in 24 cases.

RESULTS

ICC was successful in 33 cases (18 CB and 15 CS) and not evaluable in 5 cases (4 CB and 1 CS). The CD10‐BCL6‐MUM1 algorithm subclassified DLBCL as GCB (9 cases) and non‐GCB (24 cases). ICC data were confirmed on histologic staining in 24 cases.

CONCLUSIONS

CD10, BCL6, and MUM1 ICC staining can be performed on FNA samples. The results herein prove it is reliable both on CB and CS, and is equally effective and comparable to immunohistochemistry data. Cancer (Cancer Cytopathol) 2016;124:135–143. © 2015 American Cancer Society.
Cytopathologic diagnosis of oncocytic type intraductal papillary mucinous neoplasm: Criteria and clinical implications of accurate diagnosis
Authors: Reid Michelle D. , Stallworth Christina R. , Lewis Melinda M. , Akkas Gizem , Memis Bahar , Basturk Olca , Adsay Volkan
Published: September 2015

BACKGROUND

Cytologic findings of pancreatic oncocytic‐type intraductal papillary mucinous neoplasms (IPMNs)/intraductal oncocytic papillary neoplasms (IOPNs) are largely unknown.

METHODS

Five IOPNs encountered by the authors were analyzed.

RESULTS

Four IOPNs were located in the pancreatic head, and 1 was located in the pancreatic body/tail in 2 men and 3 women ages 56 to 84 years (mean age, 66 years). Radiologic diagnoses included pancreatic ductal adenocarcinoma (PDAC) in 2 patients, invasive cancer associated with IPMN in 1 patient, IPMN versus mucinous cystic neoplasm in 1 patient, and cystic mass in 1 patient. Cytologic findings included: hypercellular smears (4 of 5 cases) containing well formed clusters of oncocytic cells (5 of 5 cases) with prominent, slightly eccentric nucleoli (4 of 5 cases), predominantly arranged in sheets/papillary units (5 of 5 cases), with punched‐out intercytoplasmic spaces (4 of 5 cases), and with occasional 3‐dimensional groups and focal necrosis (3 of 5 cases). The intracytoplasmic mucin and thick extracellular mucin typical of other IPMNs were observed only in 2 cases and were very limited. The mean size on resection was 4.5 cm. Invasion was observed in 3 cases (0.1, 0.3, and 2.0 cm) of tubular‐type IPMN. Initial cytologic evaluation was performed by the authors in 4 of 5 cases, which were diagnosed as IOPN (n = 3) and IPMN versus cystic PDAC (n = 1). One case was initially misdiagnosed as PDAC and, on resection, proved to be noninvasive IOPN.

CONCLUSIONS

Cytologic features of IOPNs are classical, similar to their histologic counterparts, and differ significantly from other IPMN subtypes. Because of their highly complex appearance, they are often radiologically misdiagnosed as PDAC; thus, failure to recognize their characteristic features on fine‐needle aspiration may lead to inappropriate treatment. Patients with IOPN have an incomparably better prognosis than patients with ordinary PDAC, even when their neoplasms are invasive. Cancer (Cancer Cytopathol) 2016;124:122–134. © 2015 American Cancer Society.
Isotopic partitioning by small mammals in the subnivium
Authors: Calandra Ivan , Labonne Gaëlle , Mathieu Olivier , Henttonen Heikki , Lévêque Jean , Milloux Marie‐Jeanne , Renvoisé Élodie , Montuire Sophie , Navarro Nicolas
Published: September 2015

In the Arctic, food limitation is one of the driving factors behind small mammal population fluctuations. Active throughout the year, voles and lemmings (arvicoline rodents) are central prey in arctic food webs. Snow cover, however, makes the estimation of their winter diet challenging. We analyzed the isotopic composition of ever‐growing incisors from species of voles and lemmings in northern Finland trapped in the spring and autumn. We found that resources appear to be reasonably partitioned and largely congruent with phylogeny. Our results reveal that winter resource use can be inferred from the tooth isotopic composition of rodents sampled in the spring, when trapping can be conducted, and that resources appear to be partitioned via competition under the snow.
The Mechanics of Morality
Authors: Kaebnick Gregory E.
Published: September 2015

Moral philosophy has its version of physics’ search for a unified theory. Physicists have often thought it unseemly that the four fundamental forces governing how particles interact with each other cannot be reduced to one. Moral philosophers have often tried to unify the fundamental values governing how moral agents interact with each other. Bioethicists have mostly given up on complete unification and settled for drawing on multiple fundamental values. They see unification as a metatheoretical and unproductive project, too much the stuff of physics and not enough like engineering. Still, there's been a long‐running debate within bioethics about how many and which values to keep in the toolkit. Can autonomy, beneficence, and justice, fashioned into “principles,” do all of the essential work? Or are “dignity” and “solidarity,” for example, also sometimes necessary? The lead article in this issue of the Hastings Center Report argues for including solidarity in the kit.
Having Conversations about Organ Donation
Authors: Sadler Blair L. , Sadler Nicole Robins
Published: September 2015

While 90 percent of participants in a 2005 Gallup poll indicated that they would donate an organ if asked, only 40 percent of Americans have registered to do so, according to 2012 data from Donate Life America; likely even fewer have shared their donation wishes with loved ones. Undoubtedly, the single biggest reason for the discrepancy between the number of potential transplants and the number actually performed is our failure to talk with loved ones about our wishes regarding organ donation. Although many resources already exist to hold these conversations, we can do more, and the emergence of social media provides an intriguing new opportunity. Two years ago, Organize.org set out to create the first nationwide organ donation registry in the United States.
An Introduction to Thinking about Trustworthy Research into the Genetics of Intelligence
Authors: Parens Erik , Appelbaum Paul S.
Published: September 2015

The advent of new technologies has rekindled some hopes that it will be possible to identify genetic variants that will help to explain why individuals are different with respect to complex traits. At least one leader in the development of “whole genome sequencing”—the Chinese company BGI—has been quite public about its commitment to using the technique to investigate the genetics of intelligence in general and high intelligence in particular. Because one needs large samples to detect the small effects associated with small genetic differences in the sequence of those base pairs, to make headway with the new sequencing technologies, one also needs to enlist much larger numbers of study participants than geneticists have enrolled before. In an effort to increase the size of a sample, one team of researchers approached the Center for Talented Youth at Johns Hopkins University. They wanted to gain access to records concerning participants in CTY's ongoing Study of Exceptional Talent, and they wanted to approach those individuals to see if they would be willing to share samples of their DNA.

We agreed that CTY's dilemma about whether to give the researchers access to those records raised larger questions about the ethics of research into the genetics of intelligence, and we decided to hold a workshop at The Hastings Center that could examine those questions. Our purpose was to create what, borrowing from Sarah Richardson, we came to call a “transformative conversation” about research into the genetics of general cognitive ability—a conversation that would take a wide and long view and would involve a diverse group of stakeholders, including both people who have been highly critical of the research and people who engage in it. This collection of essays, which grew out of that workshop, is intended to provide an introduction to and exploration of this complex and important area.
What Does Behavioral Genetics Offer for Improving Education?
Authors: Panofsky Aaron
Published: September 2015

For much of its history, behavioral genetics, or research into the influence genetics has on human behavior, has been associated with a pessimistic view of educational reforms’ potential to make much difference in improving educational outcomes or reducing inequality. Recently, however, some behavioral geneticists have begun to speak in more optimistic terms about the promise of genetically informed education to improve learning for all children, especially those who are socially or economically disadvantaged. This shift in emphasis should be welcome news for everyone interested in promoting educational improvement who worried that behavioral genetics offered support for the status quo. However, I think it amounts to little more than a shift in tone. Behavioral genetics, I will argue, does not advance educational reform: its proposed solutions are rooted in the limits, not the strength, of behavioral genetics knowledge; repeat the ideas of earlier U.S. educational reform efforts; and rely on a naive optimism about the power of choice and personalization.
Trustworthy Research Institutions: The Challenging Case of Studying theGenetics of Intelligence
Authors: Johnston Josephine , Banerjee Mohini P. , Geller Gail
Published: September 2015

It is simple enough to claim that academic research institutions ought to be trustworthy. Building the culture and taking the steps necessary to earn and preserve institutional trust are, however, complex processes. The experience motivating this special report—a request for the Center for Talented Youth at Johns Hopkins University to collaborate on research regarding the genetics of intelligence—illustrates how ensuring institutional trustworthiness can be in tension with a commitment to fostering research. In this essay, we explore the historical context for biomedical research institutions like Johns Hopkins that have worked to build local community trust. In so doing, we consider how the example under focus in this special report can lead to greater consideration of how research institutions balance fostering trust with their other commitments.
Obligations and Concerns of an Organization Like the Center for Talented Youth
Authors: Hansen Elaine Tuttle , Gluck Stuart , Shelton Amy L.
Published: September 2015

There is another set of entities that needs to be brought into the conversation about the ethical, legal, and social implications of scientific conduct. This widely varied group includes not‐for‐profit educational, academic, public‐service, and philanthropic organizations other than the type mentioned above as well as for‐profit businesses. Despite their major differences, these organizations may all be in a position to make decisions, directly or indirectly, about the conduct of scientific research. And those decisions may have a significant impact on the parties normally involved in thinking and talking about obligations and concerns—the researchers, the subjects, and the general public. Yet there are few if any conceptual frameworks to help organizations address the ethical, legal, and social issues related to conducting scientific research. There are also few resources to help organizations find and develop the expertise required to make responsible decisions or communicate those decisions in ways that could support and advance the ethical conduct of research.

In what follows, we try to identify and explore the duties, rights, and interests of one such organization, the Center for Talented Youth at Johns Hopkins University, when asked to play a supporting role in research on the genetics of intelligence. As central agents in this case, we hope to demonstrate why organizations like CTY cannot be neglected in the broader effort to ensure trustworthy research into the genetics of intelligence.
CXCL12/CXCR4 activation by cancer‐associated fibroblasts promotes integrin β1 clustering and invasiveness in gastric cancer
Authors: Izumi Daisuke , Ishimoto Takatsugu , Miyake Keisuke , Sugihara Hidetaka , Eto Kojiro , Sawayama Hiroshi , Yasuda Tadahito , Kiyozumi Yuki , Kaida Takayoshi , Kurashige Junji , Imamura Yu , Hiyoshi Yukiharu , Iwatsuki Masaaki , Iwagami Shiro , Baba Yoshifumi , Sakamoto Yasuo , Miyamoto Yuji , Yoshida Naoya , Watanabe Masayuki , Takamori Hiroshi , Araki Norie , Tan Patrick , Baba Hideo
Published: September 2015

Cancer‐associated fibroblasts (CAFs) are reportedly involved in invasion and metastasis in several types of cancer, including gastric cancer (GC), through the stimulation of CXCL12/CXCR4 signaling. However, the mechanisms underlying these tumor‐promoting effects are not well understood, which limits the potential to develop therapeutic targets against CAF‐mediated CXCL12/CXCR4 signaling. CXCL12 expression was analyzed in resected GC tissues from 110 patients by immunohistochemistry (IHC). We established primary cultures of normal fibroblasts (NFs) and CAFs from the GC tissues and examined the functional differences between these primary fibroblasts using co‐culture assays with GC cell lines. We evaluated the efficacy of a CXCR4 antagonist (AMD3100) and a FAK inhibitor (PF‐573,228) on the invasive ability of GC cells. High CXCL12 expression levels were significantly associated with larger tumor size, increased tumor depth, lymphatic invasion and poor prognosis in GC. CXCL12/CXCR4 activation by CAFs mediated integrin β1 clustering at the cell surface and promoted the invasive ability of GC cells. Notably, AMD3100 was more efficient than PF‐573,228 at inhibiting GC cell invasion through the suppression of integrin β1/FAK signaling. These results suggest that CXCL12 derived from CAFs promotes GC cell invasion by enhancing the clustering of integrin β1 in GC cells, resulting in GC progression. Taken together, the inhibition of CXCL12/CXCR4 signaling in GC cells may be a promising therapeutic strategy against GC cell invasion.
Differential protein expression and oncogenic gene network link tyrosine kinase ephrin B4 receptor to aggressive gastric and gastroesophageal junction cancers
Authors: Liersch‐Löhn Britta , Slavova Nadia , Buhr Heinz J. , Bennani‐Baiti Idriss M.
Published: September 2015

Transmembrane tyrosine‐kinase Ephrin receptors promote tumor progression and/or metastasis of several malignancies including leukemia, follicular lymphoma, glioma, malignant pleural mesothelioma, papillary thyroid carcinoma, sarcomas and ovarian, breast, bladder and non‐small cell lung cancers. They also drive intestinal stem cell proliferation and positioning, control intestinal tissue boundaries and are involved in liver, pancreatic and colorectal cancers, indicating involvement in additional digestive system malignancies. We investigated the role of Ephrin‐B4 receptor (EPHB4), and its ligand EFNB2, in gastric and gastroesophageal junction cancers in patient cohorts through computational, mathematical, molecular and immunohistochemical analyses. We show that EPHB4 is upregulated in preneoplastic gastroesophageal lesions and its expression further increased in gastroesophageal cancers in several independent cohorts. The closely related EPHB6 receptor, which also binds EFNB2, was downregulated in all tested cohorts, consistent with its tumor‐suppressive properties in other cancers. EFNB2 expression is induced in esophageal cells by acidity, suggesting that gastroesophageal reflux disease (GERD) may constitute an early triggering event in activating EFNB2–EPHB4 signaling. Association of EPHB4 to both Barrett's esophagus and to advanced tumor stages, and its overexpression at the tumor invasion front and vascular endothelial cells intimate the notion that EPHB4 may be associated with multiple steps of gastroesophageal tumorigenesis. Analysis of oncogenomic signatures uncovered the first EPHB4‐associated gene network (false discovery rate: 7 × 10−90) composed of a five‐transcription factor interconnected gene network that drives proliferation, angiogenesis and invasiveness. The EPHB4 oncogenomic network provides a molecular basis for its role in tumor progression and points to EPHB4 as a potential tumor aggressiveness biomarker and drug target in gastroesophageal cancers.
Further investigation of a rapid restraint analysis
Authors: Deshais Meghan A. , Fisher Alyssa B. , Hausman Nicole L. , Kahng SungWoo
Published: September 2015

Research related to the use of mechanical restraint devices (e.g., arm splints) has been limited despite the frequency with which they are used in the clinical treatment of severe and dangerous self‐injurious behavior (SIB). Wallace, Iwata, Zhou, and Goff () used a rapid restraint analysis (RRA) to evaluate the effects of different levels of arm‐splint flexion on rates of hand‐to‐head SIB and adaptive behavior. The goal of the current study was 3‐fold: (a) to extend previous research on RRA by reporting RRA results for 10 participants and investigating post‐RRA outcomes, (b) to investigate whether the RRA might have the potential to eliminate the need for restraint fading altogether for some individuals, and (c) to investigate whether the RRA might help to identify a starting point for restraint fading for individuals for whom fading is necessary. Results suggested that the RRA helped to eliminate the need for restraint fading for 6 participants. With respect to the identification of a starting point for restraint fading, results were mixed. Overall, 8 of the 10 participants were discharged from the inpatient unit at a less restrictive level of flexion or at the same level of flexion identified by the RRA. Implications for adoption of the RRA are discussed.
Wear characteristics of an unconstrained lumbar total disc replacement under a range of in vitro test conditions
Authors: Hyde Philip J. , Fisher John , Hall Richard M.
Published: September 2015

The effect of kinematics, loading and centre of rotation on the wear of an unconstrained total disc replacement have been investigated using the ISO 18192‐1 standard test as a baseline. Mean volumetric wear rate and surface morphological effects were reported. Changing the phasing of the flexions to create a low (but finite) amount of crossing path motion at the bearing surfaces resulted in a significant fall in wear volume. However, the rate of wear was still much larger than previously reported values under zero cross shear conditions. Reducing the load did not result in a significant change in wear rate. Moving the centre of rotation of the disc inferiorly did significantly increase wear rate. A phenomenon of debris re‐attachment on the UHMWPE surface was observed and hypothesised to be due to a relatively harsh tribological operating regime in which lubricant replenishment and particle migration out of the bearing contact zone were limited. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 46–52, 2017.
Renal Function Descriptors in Neonates: Which Creatinine‐Based Formula Best Describes Vancomycin Clearance?
Authors: Bhongsatiern Jiraganya , Stockmann Chris , Yu Tian , Constance Jonathan E. , Moorthy Ganesh , Spigarelli Michael G. , Desai Pankaj B. , Sherwin Catherine M. T.
Published: September 2015

Growth and maturational changes have been identified as significant covariates in describing variability in clearance of renally excreted drugs such as vancomycin. Because of immaturity of clearance mechanisms, quantification of renal function in neonates is of importance. Several serum creatinine (SCr)‐based renal function descriptors have been developed in adults and children, but none are selectively derived for neonates. This review summarizes development of the neonatal kidney and discusses assessment of the renal function regarding estimation of glomerular filtration rate using renal function descriptors. Furthermore, identification of the renal function descriptors that best describe the variability of vancomycin clearance was performed in a sample study of a septic neonatal cohort. Population pharmacokinetic models were developed applying a combination of age‐weight, renal function descriptors, or SCr alone. In addition to age and weight, SCr or renal function descriptors significantly reduced variability of vancomycin clearance. The population pharmacokinetic models with Léger and modified Schwartz formulas were selected as the optimal final models, although the other renal function descriptors and SCr provided reasonably good fit to the data, suggesting further evaluation of the final models using external data sets and cross validation. The present study supports incorporation of renal function descriptors in the estimation of vancomycin clearance in neonates.
Predator exclusion as a management option for increasing white‐tailed deer recruitment
Authors: Conner L. Mike , Cherry Michael J. , Rutledge Brandon T. , Killmaster Charles H. , Morris Gail , Smith Lora L.
Published: September 2015

Lethal control of coyotes (Canis latrans) is a mechanism for increasing white‐tailed deer (Odocoileus virginianus) recruitment but can be difficult to implement and may be ineffective on small parcels of land because of coyote immigration. In 2003, we constructed 4 40‐ha mesopredator exclosures with the objective of quantifying the influence of mesopredators, including coyotes, on select wildlife populations and communities. Camera trapping indicated neonate/adult female white‐tailed deer ratios were approximately 2 times greater inside predator exclosures than in control plots. Hunter success data provided further evidence of increased recruitment associated with exclosures relative to the remainder of the study site. Because exclosures were located on the boundary of our study area and off‐site white‐tailed deer harvest records were not available, we used estimates of deer density, sex ratios, reproductive rates, relative use of exclosures, and neonate survival inside and outside of exclosures to parameterize a Monte Carlo simulation model to estimate the impact of our 4 exclosures on neonate recruitment into the start of the firearms hunting season on a 1,600‐ha area. After 1,000 iterations, we estimated that predator exclusion provided an additional 18 ± 0.13 ( ± SE; median = 15, interquartile range [IQR] = 9–24) recruits/year above that expected without exclusion. Simulated neonate/adult female ratio was 0.74 ± 0.03 (median = 0.72, IQR = 0.52–0.93) with exclosures and 0.41 ± 0.008 (median = 0.39, IQR = 0.21–0.58) without. Simulated exclosure impact on recruitment was most sensitive to white‐tailed deer relative use of exclosures and was least sensitive to neonate survival inside exclosures. We suggest that predator exclusion may be an effective mechanism for reducing neonate mortality and increasing white‐tailed deer recruitment in areas where neonate survival is affected by predation. Exclosures may be particularly valuable on small parcels of land where predator removal would be offset by immigration. Finally, exclosures provide refuge from predators throughout the year, and we hypothesize exclosures may also contribute to adult survival and reduce impacts of predation risk that may also affect white‐tailed deer population dynamics. Additional research incorporating variation in exclosure size and white‐tailed deer density is needed to better evaluate predator exclosures for creating neonate refugia and mitigating sub‐lethal impacts of predation. © 2015 The Wildlife Society.
On‐axis shaping of second‐harmonic beams
Authors: Trajtenberg‐Mills Sivan , Juwiler Irit , Arie Ady
Published: September 2015

We report complete spatial shaping (both phase and amplitude) of the second‐harmonic beam generated in a nonlinear photonic crystal. Using a collinear second‐order process in a nonlinear computer generated hologram imprinted on the crystal, the desired beam is generated on‐axis and in the near field. This enables compact and efficient one‐dimensional beam shaping in comparison to previously demonstrated off‐axis Fourier holograms. We experimentally demonstrate the second‐harmonic generation of high‐order Hermite–Gauss, top hats and arbitrary skyline‐shaped beams.

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Investigating hydroxyl chemical exchange using a variable saturation power chemical exchange saturation transfer (vCEST) method at 3 T
Authors: Clark Daniel James , Smith Alex K. , Dortch Richard D. , Knopp Michael V. , Smith Seth A.
Published: September 2015

Purpose

To develop a chemical exchange saturation transfer (CEST) scheme sensitive to hydroxyl protons at 3 T. Clinical imaging of hydroxyl moieties can have an impact on osteoarthritis, neuropsychiatric disorders, and cancer.

Theory: By varying saturation amplitude linearly with frequency offset, the direct water saturation component of the Z‐spectrum is flattened and can be subtracted to produce a magnetization transfer ratio difference spectrum (MTRdiff) that isolates solute resonances. Variable saturation power allows for near optimization of hydroxyl and amine/amide moieties in one Z‐spectrum.

Methods

Phantom studies were used to test vCEST performance in two environments: (1) aqueous single‐solute (glycogen, glucose); (2) aqueous multiple solute (glycogen with bovine serum albumin). In vivo vCEST imaging of glycosaminoglycan content in patellar‐femoral cartilage was performed in a subject with history of cartilage transplant.

Results

In solutions with overlapping resonances, vCEST resolves separate hydroxyl and amine/amide peaks. CEST hydroxyl signal in cartilage is negligible, but with vCEST, hydroxyl signal ranged from 2 to 5% ppm and showed distinct contrast between lesions and normal appearing cartilage.

Conclusion

Introduced a variable saturation amplitude CEST (vCEST) scheme to improve sensitivity to exchangeable hydroxyl moieties at 3 T resulting in detection of hydroxyl in the presence of multiple solutes with overlapping resonances. Magn Reson Med 76:826–837, 2016. © 2015 Wiley Periodicals, Inc.
Investigating GluCEST and its specificity for pH mapping at low temperatures
Authors: Wermter Felizitas C. , Bock Christian , Dreher Wolfgang
Published: September 2015

Chemical exchange saturation transfer (CEST) from glutamate to water (GluCEST) is a powerful tool for mapping glutamate concentration and intracellular pH. GluCEST could also be helpful to understand the physiology of lower aquatic vertebrates and invertebrates. Therefore, this study aimed to investigate the GluCEST effect and the exchange rate ksw from amine protons of glutamate to water in a broad range of temperatures (1–37°C) and pH (5.5–8.0). Z‐spectra were measured from glutamate solutions at different pH values and temperatures and analysed by numerically solving the Bloch–McConnell equation. As expected, a strong dependence of the GluCEST effect and the determined ksw values on pH and temperature was observed. In addition, a strong dependence of the GluCEST effect on phosphate buffer concentration was confirmed. The in vitro data show that GluCEST is detectable in the whole temperature range, even at 1°C. An interpolation function for the exchange rate ksw was determined for the considered range of temperatures and pH values, showing a bijective relation between the exchange rate and pH at a given temperature. To investigate the specificity of GluCEST imaging at low temperatures, the CEST effect was investigated for several metabolites relevant for CEST imaging of the brain. As an example, the contribution of GluCEST to the total CEST effect at 3 ppm was estimated for zebrafish (Danio rerio). It is shown that also at lower temperatures glutamate is the major contributor to the total CEST effect, particularly if the experimental parameters are optimized. Copyright © 2015 John Wiley & Sons, Ltd.
Electrochemical procedure for constructing poly(phenylene sulfide) brushes on glassy carbon and stainless steel
Authors: Shimizu Kyoko , Helen Blaikie Frances , Kongsfelt Mikkel , Damgaard Schøler Sørensen Kristian , Uttrup Pedersen Steen , Daasbjerg Kim
Published: September 2015

A simple electrochemical approach based on potential sweeping has been developed for growing poly(phenylene sulfide) (PPS) brushes from 4,4’‐disulfanediyldibenzenediazonium salt on glassy carbon and stainless steel. First, the diazonium salt becomes reduced at the substrate on the initial part of the sweep carried out in a negative direction to form a covalently bonded diphenyl disulfide film. Once sufficiently extreme potentials are reached the disulfide bridges are reductively cleaved to form a thin layer of covalently attached thiophenolates. These are prone to be involved in fast coupling reactions with the diazonium salt to form PPS brushes in a repetitive growth process. In this manner linear PPS brushes with thicknesses up to 150 nm are easily formed. In addition, exact control on the brush length may be exerted through the switching potential selected or the number of sweeps applied. The films are characterized by time‐of‐flight secondary ion mass spectrometry which shows that the film growth is accompanied by an increase in the intensity ratio of S−/
in line with the proposed PPS structure. This structure was further supported by Raman spectra, exhibiting a high‐intensity C−S stretch band and no S−S stretch band. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 91–98
Organocatalytic synthesis of novel renewable non‐isocyanate polyhydroxyurethanes
Authors: Duval Charlotte , Kébir Nasreddine , Jauseau Raphaël , Burel Fabrice
Published: September 2015

Novel fully renewable AA‐BB type non‐isocyanate polyhydroxyurethanes were synthesized by the classical reaction between a diamine and a dicyclocarbonate. Sebacic acid was first reacted with an excess of glycerol carbonate, in presence of DCC and DMPA, leading to a renewable dicyclocarbonate monomer. Then, this monomer was reacted with several renewable diamines, in presence of 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene (TBD), as organocatalyst, to afford linear and branched polymers. The obtained materials exhibited Tg values varied from −27 to −8 °C, Tm values varying from 100 to 165 °C, and thermal stabilities above 200 °C. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 758–764
Poly(3‐hexylthiophene) films prepared using binary solvent mixtures
Authors: Gordon Madeleine P. , Lloyd Lawson T. , Boucher David S.
Published: September 2015

Binary solvent mixtures were routinely used to induce the hierarchical assembly of poly(3‐hexylthiophene) (P3HT) in the liquid phase. This technique has garnered a lot of interest as a route to well‐organized films and composites, but, to date, the impact that the attributes of the liquid‐phase aggregates and solvent mixtures have on the organization of the films have only been partially scrutinized. The molecular weight and concentration dependence of P3HT assembly in three binary solvent mixtures containing chloroform and acetonitrile, n‐hexane, or dichloromethane were studied using ultraviolet/visible absorbance spectroscopy and dynamic light scattering techniques. Films drop cast under slow and rapid evaporation conditions were observed using optical and atomic force microscopy. In general, there is no evidence that the characteristics of the liquid phase P3HT aggregates impact the structures of the films, but films cast from these solvent mixtures under rapid evaporation conditions exhibit an array of disparate morphologies and mesoscale patterning. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 624–638
Electrochemical performance of boron‐doped diamond films on tungsten rods with silicon interlayer
Authors: Muralidhar Pavan , Hartl Fabian W. , Kibler Ludwig A. , Pasquarelli Alberto , Strehle Steffen
Published: September 2015

Diamond films must be deposited liquid‐tight onto conductive substrates when focusing on electrochemical applications to avoid low performance or limited reproducibility due to leakage currents, corrosion, and film delamination. Here, we report on the growth of such liquid‐tight boron‐doped nanocrystalline diamond films onto tungsten rods via silicon interlayers, resembling electrochemical electrodes. These electrodes were thoroughly studied with respect to their electrochemical performance. Cyclic voltammetry revealed for instance a broad double‐layer region of about 2–3 V and low‐background currents. The electron transfer reactions were performed with [Ru(NH3)6]Cl3 and K4[Fe(CN6)] solutions to study the effect of electrode properties on reaction kinetics.
Na2SiO3 liquid glass‐based phosphor material for white LEDs
Authors: Shvaleva M. A. , Shulga E. , Kink I. , Mynbaev K. D. , Bougrov V. E. , Romanov A. E.
Published: September 2015

A liquid glass‐based phosphor material for white light‐emitting diodes (LEDs) is proposed. The material is based on sodium silicate (Na2SiO3) matrix with embedded microparticles of cerium‐doped yttrium aluminum garnet (YAG:Се3+). The technique for the material synthesis is described. The results of investigation of the optical and thermal characteristics of the material and a white LED module with a primary optic element made of the material are presented. Advantages of the developed phosphor material for primary optics applications in high‐power LED modules as compared to commercial silicone are demonstrated.
Many‐body dispersion interactions for periodic systems based on maximally localized Wannier functions: Application to graphene/water systems
Authors: Partovi‐Azar Pouya , Kühne Thomas D.
Published: September 2015

We extend the method of Silvestrelli [P. L. Silvestrelli, J. Chem. Phys. 139, 054106 (2013)] to approximate long‐range van der Waals interactions at the density functional level of theory to periodic systems. The eventual approach is based on a combination of maximally localized Wannier functions with the quantum harmonic oscillator‐model. Applying this scheme to study London dispersion forces between graphene and water layers, we find that collective many‐body effects beyond simple pair‐wise additive interactions are essential to accurately describe van der Waals forces.
Comparison of methods to determine triple oxygen isotope composition of N2O
Authors: Dyckmans Jens , Lewicka‐Szczebak Dominika , Szwec Lars , Langel Reinhard , Well Reinhard
Published: September 2015

Rationale

The oxygen isotope anomaly, Δ17O, of N2O and nitrate is useful to elucidate nitrogen oxide dynamics. A comparison of different methods for Δ17O measurement was performed.

Methods

For Δ17O measurements, N2O was converted into O2 and N2 using microwave‐induced plasma in a quartz or corundum tube reactor, respectively, or conversion was carried out in a gold wire oven. In each case, isotope ratios were measured by isotope ratio mass spectrometry.

Results

All the tested methods showed acceptable precision (coefficient of variation <2.4 % at 160 nmol N2O) with high sample size but the sample size dependence was lowest when using microwave‐induced plasma in a corundum tube reactor.

Conclusions

The use of microwave‐induced plasma in a corundum tube yields best results for Δ17O measurement on N2O gas samples. Copyright © 2015 John Wiley & Sons, Ltd.
Comparative metabolism of four limonoids in human liver microsomes using ultra‐high‐performance liquid chromatography coupled with high‐resolution LTQ‐Orbitrap mass spectrometry
Authors: Ren Wei , Xin Shao‐Kun , Han Ling‐Yu , Zuo Ran , Li Yan , Gong Mu‐Xing , Wei Xiao‐Lu , Zhou Yan‐Yan , He Jing , Wang Hong‐Jie , Si Nan , Zhao Hai‐Yu , Yang Jian , Bian Bao‐Lin
Published: September 2015

Rationale

Limonoids, characterized by a triterpenoid skeleton with a furan ring, are unique secondary metabolites widely distributed in the families of Rutaceae, particularly in Citrus species and Meliaceae. Studies on health benefits have demonstrated that limonoids have a range of biological activities. Dietary intake of citrus limonoids may provide a protective effect against the onset of various cancers and other xenobiotic related diseases. However, few studies about the metabolic profiles of limonoids have been carried out.

Methods

The objectives of this study were to investigate the metabolic profiles of four limonoids (limonin, obacunone, nominin and gedunin) in human liver microsomes (HLMs) using ultra‐high‐performance liquid chromatography coupled with high‐resolution mass spectrometry (UHPLC/HRMS) and to identify the cytochrome P450 (CYP) enzymes involved in the formation of their metabolites by recombinant human CYP enzymes.

Results

Based on the accurate HR‐MS/MS spectra and the proposed MS/MS fragmentation pathways, four metabolites of limonin (M1‐1, M1‐2, M1‐3 and M1‐4), eight metabolites ofobacunone (M2‐1, M2‐2, M2‐3, M2‐4, M2‐5, M2‐6, M2‐7 and M2‐8), six metabolites of nominin (M3‐1, M3‐2, M3‐3, M3‐4, M3‐5 and M3‐6) and three metabolites of gedunin (M4‐1, M4‐2 and M4‐3) in HLMs were tentatively identified and the involved CYPs were investigated.

Conclusions

The results demonstrated that reduction at C‐7 and C‐16, hydroxylation and reaction of glycine with reduction limonoids were the major metabolic pathways of limonoids in HLMs. Among them, glycination with reduction was the unique metabolic process of limonoids observed for the first time. CYP2D6 and CYP3A4 played an important role in the isomerization and glycination of limonoids in HLMs, whereas other CYP isoforms were considerably less active. The results might help to understand the metabolic process of limonoids in vitro such as the unidentified metabolites of limonin glucoside observed in the medium of microbes and the biotransformation of limonin in juices. Moreover, it would be beneficial for us to further study the pharmacokinetic behavior of limonoids in vivo systematically. Copyright © 2015 John Wiley & Sons, Ltd.
Study of the non‐covalent interactions of ginsenosides and lysozyme using electrospray ionization mass spectrometry
Authors: Tang Jun , Fu Qiang , Cui Meng , Xing Junpeng , Liu Zhiqiang , Liu Shuying
Published: September 2015

Rationale

Ginsenosides are an important class of natural products extracted from ginseng that possess various important biological activities. Studies of interactions of ginsenosides with proteins are essential for comprehensive understanding of the biological activities of ginsenosides. In this study, the interactions of ginsenosides with lysozyme were investigated by electrospray ionization mass spectrometry (ESI‐MS).

Methods

Both protopanaxadiol‐type and protopanaxatriol‐type ginsenosides were chosen to explore the interactions of ginsenosides towards lysozyme near the physiological conditions by direct ESI‐MS, respectively. Comparative experiments were conducted to confirm the interactions were specific. In addition, the dissociation constants of ginsenoside‐lysozyme complexes were determined by a ESI‐MS titration strategy.

Results

The results showed ginsenosides bound to lysozyme at the stoichiometries of 1:1 and 2:1. The association constants of ginsenosides to lysozyme were in the order of Re>Rd>Rf>Rg2>Rg3. According to their structures, the binding affinities associated with the type of aglycone and the type and the number of sugar moieties linked on the aglycone.

Conclusions

It has been demonstrated that ESI‐MS is a powerful tool to probe the non‐covalent interactions between lysozyme and ginsenosides. These results provide insights into the interaction of ginsenosides with lysozyme at the molecular level. The developed strategy could be applied to determine the interactions of proteins with other natural products. Copyright © 2015 John Wiley & Sons, Ltd.
The Mutual Interaction of Plasma Electrons
Authors: Haseltine W. R.
Published: September 2015

This paper considers some of the processes taking place in a simplified model of the plasma or positive column region of an electrical discharge through gas at low pressure. Particular attention is given the direct mutual interaction of the electrons, and the effect of this on the distribution of velocities.

The first part deals with the question in a general way. To determine the velocity distribution function, two balance equations are set up. One expresses the conservation of energy, and the second the conservation of momentum parallel to the field. From these is derived one non‐linear integral equation.

The geometry of the mutual scattering process is examined, and the necessary integrations are performed insofar as these depend only on this geometry. As an example the case of elastic sphere collisions is carried through to a point where integrations over the distribution function, f, become necessary.

In the second part the cross section function σ is derived for electrone‐lectron
scattering. As an interaction potential, the shielded Coulomb
value was used.

In the third part an attempt is made to find functions which are solutions
of the problem. Under the assumptions used, it is found that the
function
urn:x-wiley:00971421:media:sapm1939181174:sapm1939181174-math-0002
is a fairly good approximate solution.

It is found that experimental conditions can exist for which the theory predicts a value of the parameter g nearly unity. This corresponds to a nearly maxwellian distribution.