bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extended leaf phenology in deciduous forest invaders: mechanisms of impact on native communities
Authors: Smith L.M. 
Published: May 2013

AbstractMany high‐impact invaders of temperate deciduous forests of Eastern North America exhibit extended leaf phenology compared to native species, with leaf emergence occurring earlier in the spring and abscission occurring later in the autumn. This observation indicates that extended phenology may be an important invasion mechanism for this system. However, most evidence that extended leaf phenology drives species invasion is anecdotal, and most studies that directly address the role of leaf phenology in invasion focus solely on increased invader growth. Beyond increasing invader growth, extended leaf phenology may drive invader impact on natives by (1) facilitating resource competition through nutrient pre‐emption and shading, (2) altering production of secondary chemicals by invasive plants, (3) altering apparent competition dynamics mediated by native herbivores, (4) allowing temporal enemy escape, and (5) altering behaviour of native pollinators. I review current evidence from the literature regarding each of these possible consequences of extended invader phenology and emphasize the need for experimental manipulations to measure the extent to which extended leaf phenology mediates impact on the native community. Understanding the importance of leaf phenology in species invasion will facilitate prevention of future invasions while elucidating the role of seasonality in shaping species interactions.
Interplay of Aro80 and GATA activators in regulation of genes for catabolism of aromatic amino acids in Saccharomyces cerevisiae
Authors: Lee Kyusung , Hahn Ji‐Sook 
Published: May 2013

SummaryAro80, a member of the Zn2Cys6 family proteins, activates expression of the ARO9 and ARO10 genes involved in catabolism of aromatic amino acids in response to aromatic amino acids that act as inducers. ARO9 and ARO10 are also under the control of nitrogen catabolite repression, but the direct roles for GATA factors, Gat1 and Gln3, in this regulation have not yet been elucidated. Here, we demonstrate that Aro80 is constitutively bound to its target promoters and activated by inducers at the level of transactivation. Although Aro80 also binds to its own promoter, ARO80 expression is induced only by rapamycin, but not by tryptophan. We show that Aro80 is absolutely required for Gat1 binding to the ARO9, ARO10 and ARO80 promoters upon rapamycin treatment. Gln3 binding to these promoters shows a partial requirement for Aro80. Rapamycin‐dependent Gat1 and Gln3 binding to the Aro80 target promoters is not affected by tryptophan availability, suggesting that transactivation activity of Aro80 is not necessary for the recruitment of GATA factors. Rapamycin‐dependent induction of Aro80 target genes also requires PP2A phosphatase complex, but not Sit4 phosphatase, acting downstream of TORC1.
Health promotion behavior in middle‐aged Koreans: A cross sectional survey
Authors: Yeun Eun Ja , Baek Sunsook , Kim Heejeong 
Published: May 2013

AbstractThis cross‐sectional study was conducted to verify self‐efficacy, self‐esteem, and social support as characteristics of health promotion behavior in middle‐aged Koreans, and the influence of social support on self‐efficacy and self‐esteem with respect to health promotion behavior. Data were collected from 310 subjects in South Korea using a self‐administered questionnaire. We found a significant finding that self‐efficacy positively influences health promotion behavior, focusing on the moderating effect of social support. Self‐efficacy affected health promotion behavior (P < 0.01) as did social support. Mean self‐efficacy, self‐esteem, health promotion behavior, and social support scores were 50.27, 29.35, 124.39, and 76.51, respectively. This finding provides strong evidence that social support can be used as a model to understand health promotion behavior. Individualized nursing interventions based on social support and self‐efficacy theory should be utilized in high‐risk middle‐aged patients so as to assist and improve health promotion behavior. Also, in community practice settings, nurses should consider that increased social support and self‐efficacy are required to improve health promotion behaviors.
How to become a tree without wood – biomechanical analysis of the stem ofCarica papayaL
Authors: Kempe A. , Lautenschläger T. , Lange A. , Neinhuis C. 
Published: May 2013

AbstractCarica papayaL. does not contain wood, according to the botanical definition of wood as lignified secondary xylem. Despite its parenchymatous secondary xylem, these plants are able to grow up to 10‐m high. This is surprising, as wooden structural elements are the ubiquitous strategy for supporting height growth in plants. Proposed possible alternative principles to explain the compensation for lack of wood inC. papayaare turgor pressure of the parenchyma, lignified phloem fibres in the bark, or a combination of the two. Interestingly, lignified tissue comprises only 5–8% of the entire stem mass. Furthermore, the phloem fibres do not form a compact tube enclosing the xylem, but instead form a mesh tubular structure. To investigate the mechanism of papaya's unusually high mechanical strength, a set of mechanical measurements were undertaken on whole stems and tissue sections of secondary phloem and xylem. The structuralYoung's modulus of mature stems reached 2.5 GPa. Since this is low compared to woody plants, the flexural rigidity of papaya stem construction may mainly be based on a higher second moment of inertia. Additionally, stem turgor pressure was determined indirectly by immersing specimens in sucrose solutions of different osmolalities, followed by mechanical tests; turgor pressure was between 0.82 and 1.25 MPa, indicating that turgor is essential for flexural rigidity of the entire stem.
A missense mutation in CHS1, a TIR‐NB protein, induces chilling sensitivity in Arabidopsis
Authors: Wang Yuancong , Zhang Yao , Wang Zheng , Zhang Xiaoyan , Yang Shuhua 
Published: May 2013

SummaryLow temperature is an environmental factor that affects plant growth and development and plant–pathogen interactions. How temperature regulates plant defense responses is not well understood. In this study, we characterized chilling‐sensitive mutant 1 (chs1), and functionally analyzed the role of the CHS1 gene in plant responses to chilling stress. The chs1 mutant displayed a chilling‐sensitive phenotype, and also displayed defense‐associated phenotypes, including extensive cell death, the accumulation of hydrogen peroxide and salicylic acid, and an increased expression of PR genes: these phenotypes indicated that the mutation in chs1 activates the defense responses under chilling stress. A map‐based cloning analysis revealed that CHS1 encodes a TIR‐NB‐type protein. The chilling sensitivity of chs1 was fully rescued by pad4 and eds1, but not by ndr1. The overexpression of the TIR and NB domains can suppress the chs1–conferred phenotypes. Interestingly, the stability of the CHS1 protein was positively regulated by low temperatures independently of the 26S proteasome pathway. This study revealed the role of a TIR‐NB‐type gene in plant growth and cell death under chilling stress, and suggests that temperature modulates the stability of the TIR‐NB protein in Arabidopsis.
A ‘toothache tree’ alkylamide inhibits Aδ mechanonociceptors to alleviate mechanical pain
Authors: Tsunozaki Makoto , Lennertz Richard C. , Vilceanu Daniel , Katta Samata , Stucky Cheryl L. , Bautista D. M. 
Published: May 2013

Key points
Extracts from the toothache tree (Zanthoxylum) are used to treat inflammatory pain, such as toothache and arthritis.
Hydroxy‐α‐sanshool (sanshool) is a major alkylamide in extracts from Zanthoxylum plants.
Sanshool treatment in mice caused a selective attenuation of mechanical sensitivity under naïve and inflammatory conditions
Sanshool inhibits Aδ mechanonociceptors that mediate both sharp acute pain and inflammatory pain, and inhibits the activity of multiple voltage‐gated sodium channel subtypes, among which Nav1.7 is the most strongly affected.
Our data implicate Nav1.7 as a key mediator of inflammatory mechanical pain in ‘fast pain’ mechanosensory neurons.
Abstract  In traditional medicine, the ‘toothache tree’ and other plants of the Zanthoxylum genus have been used to treat inflammatory pain conditions, such as toothache and rheumatoid arthritis. Here we examined the cellular and molecular mechanisms underlying the analgesic properties of hydroxy‐α‐sanshool, the active alkylamide produced by Zanthoxylum plants. Consistent with its analgesic effects in humans, sanshool treatment in mice caused a selective attenuation of mechanical sensitivity under naïve and inflammatory conditions, with no effect on thermal sensitivity. To elucidate the molecular mechanisms by which sanshool attenuates mechanical pain, we performed single fibre recordings, calcium imaging and whole‐cell electrophysiology of cultured sensory neurons. We found that: (1) sanshool potently inhibits Aδ mechanonociceptors that mediate both sharp acute pain and inflammatory pain; (2) sanshool inhibits action potential firing by blocking voltage‐gated sodium currents in a subset of somatosensory neurons, which express a unique combination of voltage‐gated sodium channels; and (3) heterologously expressed Nav1.7 is most strongly inhibited by sanshool as compared to other sodium channels expressed in sensory neurons. These results suggest that sanshool targets voltage‐gated sodium channels on Aδ mechanosensory nociceptors to dampen excitability and thus induce ‘fast pain’ analgesia.
Experimental demonstration of novel imaging geometries for x‐ray fluorescence computed tomography
Authors: Fu Geng , Meng Ling‐Jian , Eng Peter , Newville Matt , Vargas Phillip , Riviere Patrick La 
Published: May 2013

Purpose:X‐ray fluorescence computed tomography (XFCT) is an emerging imaging modality that maps the three‐dimensional distribution of elements, generally metals, inex vivo specimens and potentially in living animals and humans. At present, it is generally performed at synchrotrons, taking advantage of the high flux of monochromatic x rays, but recent work has demonstrated the feasibility of using laboratory‐based x‐ray tube sources. In this paper, the authors report the development and experimental implementation of two novel imaging geometries for mapping of trace metals in biological samples with ∼50–500 μm spatial resolution.Methods:One of the new imaging approaches involves illuminating and scanning a single slice of the object and imaging each slice's x‐ray fluorescent emissions using a position‐sensitive detector and a pinhole collimator. The other involves illuminating a single line through the object and imaging the emissions using a position‐sensitive detector and a slit collimator. They have implemented both of these using synchrotron radiation at the Advanced Photon Source.Results:The authors show that it is possible to achieve 250 eV energy resolution using an electron multiplying CCD operating in a quasiphoton‐counting mode. Doing so allowed them to generate elemental images using both of the novel geometries for imaging of phantoms and, for the second geometry, an osmium‐stained zebrafish.Conclusions:The authors have demonstrated the feasibility of these two novel approaches to XFCT imaging. While they use synchrotron radiation in this demonstration, the geometries could readily be translated to laboratory systems based on tube sources.
Mapping motion from 4D‐MRI to 3D‐CT for use in 4D dose calculations: A technical feasibility study
Authors: Boye Dirk , Lomax Tony , Knopf Antje 
Published: May 2013

Purpose:Target sites affected by organ motion require a time resolved (4D) dose calculation. Typical 4D dose calculations use 4D‐CT as a basis. Unfortunately, 4D‐CT images have the disadvantage of being a “snap‐shot” of the motion during acquisition and of assuming regularity of breathing. In addition, 4D‐CT acquisitions involve a substantial additional dose burden to the patient making many, repeated 4D‐CT acquisitions undesirable. Here the authors test the feasibility of an alternative approach to generate patient specific 4D‐CT data sets.Methods:In this approach motion information is extracted from 4D‐MRI. Simulated 4D‐CT data sets [which the authors call 4D‐CT(MRI)] are created by warping extracted deformation fields to a static 3D‐CT data set. The employment of 4D‐MRI sequences for this has the advantage that no assumptions on breathing regularity are made, irregularities in breathing can be studied and, if necessary, many repeat imaging studies (and consequently simulated 4D‐CT data sets) can be performed on patients and/or volunteers. The accuracy of 4D‐CT(MRI)s has been validated by 4D proton dose calculations. Our 4D dose algorithm takes into account displacements as well as deformations on the originating 4D‐CT/4D‐CT(MRI) by calculating the dose of each pencil beam based on an individual time stamp of when that pencil beam is applied. According to corresponding displacement and density‐variation‐maps the position and the water equivalent range of the dose grid points is adjusted at each time instance.Results:4D dose distributions, using 4D‐CT(MRI) data sets as input were compared to results based on a reference conventional 4D‐CT data set capturing similar motion characteristics. Almost identical 4D dose distributions could be achieved, even though scanned proton beams are very sensitive to small differences in the patient geometry. In addition, 4D dose calculations have been performed on the same patient, but using 4D‐CT(MRI) data sets based on variable breathing patterns to show the effect of possible irregular breathing on active scanned proton therapy. Using a 4D‐CT(MRI), including motion irregularities, resulted in significantly different proton dose distributions.Conclusions:The authors have demonstrated that motion information from 4D‐MRI can be used to generate realistic 4D‐CT data sets on the basis of a single static 3D‐CT data set. 4D‐CT(MRI) presents a novel approach to test the robustness of treatment plans in the circumstance of patient motion.
Subcellular Clustering of the Phosphorylated WspR Response Regulator Protein Stimulates Its Diguanylate Cyclase Activity
Authors: Huangyutitham Varisa , Güvener Zehra Tüzün , Harwood Caroline S. 
Published: May 2013

ABSTRACTWspR is a hybrid response regulator-diguanylate cyclase that is phosphorylated by the Wsp signal transduction complex in response to growth ofPseudomonas aeruginosaon surfaces. Active WspR produces cyclic di-GMP (c-di-GMP), which in turn stimulates biofilm formation. In previous work, we found that when activated by phosphorylation, yellow fluorescent protein (YFP)-tagged WspR forms clusters that are visible in individual cells by fluorescence microscopy. Unphosphorylated WspR is diffuse in cells and not visible. Thus, cluster formation is an assay for WspR signal transduction. To understand how and why WspR forms subcellular clusters, we analyzed cluster formation and the enzymatic activities of six single amino acid variants of WspR. In general, increased cluster formation correlated with increasedin vivoandin vitrodiguanylate cyclase activities of the variants. In addition, WspR specific activity was strongly concentration dependentin vitro, and the effect of the protein concentration on diguanylate cyclase activity was magnified when WspR was treated with the phosphor analog beryllium fluoride. Cluster formation appears to be an intrinsic property of phosphorylated WspR (WspR-P). These results support a model in which the formation of WspR-P subcellular clustersin vivoin response to a surface stimulus is important for potentiating the diguanylate cyclase activity of WspR. Subcellular cluster formation appears to be an additional means by which the activity of a response regulator protein can be regulated.IMPORTANCEBacterial sensor proteins often phosphorylate cognate response regulator proteins when stimulated by an environmental signal. Phosphorylated response regulators then mediate an appropriate adaptive cellular response. About 6% of response regulator proteins have an enzymatic domain that is involved in producing or degrading cyclic di-GMP (c-di-GMP), a molecule that stimulates bacterial biofilm formation. In this work, we examined thein vivoandin vitrobehavior of the response regulator-diguanylate cyclase WspR. When phosphorylated in response to a signal associated with surface growth, WspR has a tendency to form oligomers that are visible in cells as subcellular clusters. Our results show that the formation of phosphorylated WspR (WspR-P) subcellular clusters is important for potentiating the diguanylate cyclase activity of WspR-P, making it more active in c-di-GMP production. We conclude that oligomer formation visualized as subcellular clusters is an additional mechanism by which the activities of response regulator-diguanylate cyclases can be regulated.
Oral Immunization with Cholera Toxin Provides Protection against Campylobacter jejuni in an Adult Mouse Intestinal Colonization Model
Authors: Albert M. John , Mustafa Abu Salim , Islam Anjum , Haridas Shilpa 
Published: May 2013

ABSTRACT

Immunity to
Campylobacter jejuni
, a major diarrheal pathogen, is largely Penner serotype specific. For broad protection, a vaccine should be based on a common antigen(s) present in all strains. In our previous study (M. J. Albert, S. Haridas, D. Steer, G. S. Dhaunsi, A. I. Smith, and B. Adler, Infect. Immun. 75:3070–3073, 2007), we demonstrated that antibody to cholera toxin (CT) cross-reacted with the major outer membrane proteins (MOMPs) of all
Campylobacter jejuni
strains tested. In the current study, we investigated whether immunization with CT protects against intestinal colonization by
C. jejuni
in an adult mouse model and whether the nontoxic subunit of CT (CT-B) is the portion mediating cross-reaction. Mice were orally immunized with CT and later challenged with
C. jejuni
strains (48, 75, and 111) of different serotypes. Control animals were immunized with phosphate-buffered saline. Fecal shedding of challenge organisms was studied daily for 9 days. Serum and fecal antibody responses were studied by enzyme-linked immunosorbent assay (ELISA) and immunoblotting. The cross-reactivity of rabbit CT-B antibody to MOMP was studied by immunoblotting. The reactivity of 21 overlapping 30-mer oligopeptides (based on MOMP’s sequence) against rabbit CT antibody was tested by ELISA. Test animals produced antibodies to CT and MMP in serum and feces and showed resistance to colonization, the vaccine efficacies being 49% (for strain 48), 37% (for strain 75), and 34% (for strain 111) (
P
, ≤0.05 to ≤0.001). One peptide corresponding to a variable region of MOMP showed significant reactivity. CT-B antibody cross-reacted with MOMP. Since CT-B is a component of oral cholera vaccines, it might be possible to control
C. jejuni
diarrhea with these vaccines.

IMPORTANCE
Campylobacter jejuni
is a major cause of diarrhea worldwide. Patients who recover from
C. jejuni
diarrhea develop immunity to the infecting serotype and remain susceptible to infection with other serotypes. A vaccine based on a common protective antigen(s) present in all
C. jejuni
serotypes is expected to provide broad protection. In our previous study, we showed that antibody to cholera toxin (CT) reacted with the major outer membrane proteins (MOMPs) from different strains of
C. jejuni
. We assumed that the B subunit of the toxin (CT-B), which is nontoxic and a component of licensed oral cholera vaccines, might be the component that cross-reacts with MOMP. In the current study, we showed that orally immunizing mice with CT protected them against colonization upon challenge with different serotypes of
C. jejuni
. We also showed that CT-B is the component mediating cross-reaction. Therefore, it might be possible to use cholera vaccines to prevent
C. jejuni
diarrhea. This could result in significant savings in vaccine development and treatment of the disease.
Molecular Dissection of Bacterial Nanowires
Authors: Boesen Thomas , Nielsen Lars Peter 
Published: May 2013

ABSTRACT

The discovery of bacterial conductive structures, termed nanowires, has intrigued scientists for almost a decade. Nanowires enable bacteria to transfer electrons over micrometer distances to extracellular electron acceptors such as insoluble metal oxides or electrodes. Nanowires are pilus based and in
Geobacter sulfurreducens
are composed of the type IV pilin subunit PilA. Multiheme
c
-type cytochromes have been shown to attach to nanowire pili. Two hypotheses have been proposed for electron conduction in nanowires. The first (termed the metal-like conductivity or MLC hypothesis) claims that the pilus itself has the electron-conductive properties and the attached cytochromes mediate transfer to the final electron acceptor, whereas the second hypothesis (termed the superexchange conductivity or SEC hypothesis) suggests that electrons are “hopping” between heme groups in cytochromes closely aligned with the pilus as a scaffold. In their recent article in
mBio
, Vargas et al. [M. Vargas, N. S. Malvankar, P.-L. Tremblay, C. Leang, J. A. Smith, P. Patel, O. Snoeyenbos-West, K. P. Nevin, and D. R. Lovley, mBio 4(2):e00210-13, 2013] address this ambiguity through an analysis of strain Aro-5, a
G. sulfurreducens
PilA mutant lacking aromatic residues in the nonconserved portion of PilA. These residues were suspected of involvement in electron transport according to the MLC hypothesis. The
G. sulfurreducens
mutant had reduced conductive properties, lending important support to the MLC hypothesis. The data also highlight the need for further and more conclusive evidence for one or the other hypothesis.
Phase I Study of Pazopanib in Patients with Advanced Solid Tumors and Hepatic Dysfunction: A National Cancer Institute Organ Dysfunction Working Group Study
Authors: Shibata Stephen I. , Chung Vincent , Synold Timothy W. , Longmate Jeffrey A. , Suttle A. Benjamin , Ottesen Lone H. , Lenz Heinz-Josef , Kummar Shivaani , Harvey R. Donald , Hamilton Anne L. , O'Neil Bert H. , Sarantopoulos John , LoRusso Patricia , Rudek Michelle A. , Dowlati Afshin , Mulkerin Daniel L. , Belani Chandra P. , Gandhi Leena , Lau S. Cecilia , Ivy S. Percy , Newman Edward M. 
Published: May 2013

Abstract
Purpose: Pazopanib is a potent, multitargeted receptor tyrosine kinase inhibitor; however, there is limited information regarding the effects of liver function on pazopanib metabolism and pharmacokinetics. The objective of this study was to establish the maximum-tolerated dose (MTD) and pharmacokinetic profile of pazopanib in patients with varying degrees of hepatic dysfunction.
Experimental Design: Patients with any solid tumors or lymphoma were stratified into four groups based on the degree of hepatic dysfunction according to the National Cancer Institute Organ Dysfunction Working Group (NCI-ODWG) criteria. Pazopanib was given orally once a day on a 21-day cycle. A modified 3+3 design was used.
Results: Ninety-eight patients were enrolled. Patients in the mild group tolerated 800 mg per day. The moderate and severe groups tolerated 200 mg per day. Pharmacokinetic data in the mild group were similar to the data in the normal group. Comparison of the median Cmax and area under the curve [AUC(0–24)] in the moderate or severe groups at 200 mg per day to the values in the normal and mild groups at 800 mg per day indicated less than dose–proportional systemic exposures in patients with moderate and severe hepatic impairment. This suggests that the lower maximum-tolerated dose in the moderate and severe group is not due to a decrease in drug clearance or alteration in the proportion of metabolites.
Conclusions: In patients with mild liver dysfunction, pazopanib is well tolerated at the Food and Drug Administration (FDA)–approved dose of 800 mg per day. Patients with moderate and severe liver dysfunction tolerated 200 mg per day. Clin Cancer Res; 19(13); 3631–9. ©2013 AACR.