bluuebunny/crossref_metadata_2025 huggingface dataset:
Research Papers. An Approach to Design Broadband Air Backed Piezoelectric Sensor
Authors: Ali Mohamed G.S. , Elsayed Nour Z. , Eid Ebtsam A.
Published: May 2015

In this work, an approach to the design of broadband thickness-mode piezoelectric transducer is pre- sented. In this approach, simulation of discrete time model of the impulse response of matched and backed piezoelectric transducer is used to design high sensitivity, broad bandwidth, and short-duration impulse response transducers. The effect of matching the performance of transmitting and receiving air backed PZT-5A transducer working into water load is studied. The optimum acoustical characteristics of the quarter wavelength matching layers are determined by a compromise between sensitivity and pulse duration. The thickness of bonding layers is smaller than that of the quarter wavelength matching layers so that they do not change the resonance peak significantly. Our calculations show that the −3 dB air backed transducer bandwidth can be improved considerably by using quarter wavelength matching layers. The computer model developed in this work to predict the behavior of multilayer structures driven by a transient waveform agrees well with measured results. Furthermore, the advantage of this this model over other approaches is that the time signal for optimum set of matching layers can be predicted rapidly
A Revised Sound Energy Theory Based on a New Formula for the Reverberation Radius in Rooms with Non-Diffuse Sound Field
Authors: Arau-Puchades Higini , Berardi Umberto
Published: May 2015

This paper discusses the concept of the reverberation radius, also known as critical distance, in rooms with non-uniformly distributed sound absorption. The reverberation radius is the distance from a sound source at which the direct sound level equals the reflected sound level. The currently used formulas to calculate the reverberation radius have been derived by the classic theories of Sabine or Eyring. However, these theories are only valid in perfectly diffused sound fields; thus, only when the energy density is constant throughout a room. Nevertheless, the generally used formulas for the reverberation radius have been used in any circumstance. Starting from theories for determining the reverberation time in non- diffuse sound fields, this paper firstly proposes a new formula to calculate the reverberation radius in rooms with non-uniformly distributed sound absorption. Then, a comparison between the classic formulas and the new one is performed in some rectangular rooms with non-uniformly distributed sound absorption. Finally, this paper introduces a new interpretation of the reverberation radius in non-diffuse sound fields. According to this interpretation, the time corresponding to the sound to travel a reverberation radius should be assumed as the lower limit of integration of the diffuse sound energy
Halogenation of β-estradiol by a rationally designed mesoporous biocatalyst based on chloroperoxidase
Authors: Salcedo Karina , Torres-Ramírez Eduardo , Haces Iliana , Ayala Marcela
Published: May 2015

Chloroperoxidase from Caldariomyces fumago was immobilized in Eupergit® C, a commercial mesoporous acrylic-based material. Due to low stability of the enzyme under neutral and basic pH, the usual covalent immobilization procedures cannot be applied to this enzyme. Several strategies were followed in order to achieve a stable interaction between the protein and the support. The support was efficiently functionalized with different reactive groups such as aromatic and aliphatic amines, glutaraldehyde, diazonium ions, and maleimide moieties; solvent-exposed amino acid residues in chloroperoxidase were identified or created through chemical modification, so that they were reactive under conditions where the enzyme is stable. Enzyme load and retained activity were monitored, obtaining biocatalysts with specific activity ranging from 200 to 25,000 U/g. The highest load and activity was obtained from the immobilization of a chemically-modified CPO preparation bearing a solvent-exposed free thiol group. This biocatalyst efficiently catalyzed the transformation of β-estradiol, an endocrine disruptor.
Clinical relevance of sST2 in cardiac diseases
Authors: Pascual-Figal Domingo A. , Lax Antonio , Perez-Martinez Maria Teresa , del Carmen Asensio-Lopez Maria , Sanchez-Mas Jesus , on behalf of GREAT Network
Published: May 2015

ST2 has two main isoforms, ST2L and soluble isoform of ST2 (sST2), by alternative splicing. The interaction between interleukin (IL)-33 and the transmembrane isoform ST2L is up-regulated in response to myocardial stress and exerts cardio-protective actions in the myocardium by reducing fibrosis, hypertrophy and enhancing survival. The circulating isoform sST2, by sequestering IL-33, abrogates these favorable actions and will be elevated as a maladaptive response to cardiac diseases. Indeed, circulating sST2 concentrations correlate with a worse phenotype of disease including adverse remodeling and fibrosis, cardiac dysfunction, impaired hemodynamics and higher risk of progression. In patients with acute and chronic heart failure, sST2 concentrations are strongly predictive of death, regardless of the cause and left ventricle (LV) ejection fraction, and contribute relevant information in addition to other prognosticators and biomarkers, as natriuretic peptides or troponins. sST2 also retains prognostic information in the setting of acute myocardial infarction (AMI) and predicts cardiovascular death and risk of heart failure (HF) development in these patients. sST2 could also be a promising tool to stratify the risk of sudden cardiac death (SCD) in patients with depressed LV ejection fraction. Therefore, sST2 represents a clinically relevant biomarker reflecting pathophysiological processes and contributing predictive information in the setting of several cardiovascular diseases, and especially in patients with HF.
Niobia supported on silica as a catalyst for Biodiesel production from waste oil
Authors: Tesser R. , Vitiello R. , Carotenuto G. , Garcia Sancho C. , Vergara A. , Maireles Torres P.J. , Li Changzhu , Di Serio M.
Published: May 2015

The activity and stability of niobia supported
on silica catalyst have been tested in continuous
micro-pilot reactors, for biodiesel production starting
from acid vegetable oils. A catalyst was prepared
by the impregnation of silica pellets with a loading
of 12% of Nb and was extensively characterized.
The activity of this catalyst in both esterification and
transesterification was tested in a continuous micro-pilot
laboratory plant in which acid oil was fed (FFA 10% w/w)
at a temperature of 220°C and at a pressure of 60 bar.
The niobia based catalyst resulted in a very active
catalyst in both esterification (FFA conversion =
95-90%) and transesterification reactions (FAME
yield = 80-90%), and the activity remained
quite constant for more than 100 h on stream.
Notwithstanding this stability, a non-negligible leaching
phenomena has been detected, in the case of long-time
continuous runs, as the Nb concentration on the spent
catalyst resulted lower than that on the fresh one. The
obtained result confirms that the leaching of the active
specie is one of the most strong problem in heterogeneous
catalysis for biodiesel production.
Is laboratory medicine ready for the era of personalized medicine? A survey addressed to laboratory directors of hospitals/academic schools of medicine in Europe
Authors: Malentacchi Francesca , Mancini Irene , Brandslund Ivan , Vermeersch Pieter , Schwab Matthias , Marc Janja , van Schaik Ron H.N. , Siest Gerard , Theodorsson Elvar , Pazzagli Mario , Di Resta Chiara , on behalf of the European Federation of Clinical Chemistry a
Published: May 2015

Developments in “-omics” are creating a paradigm shift in laboratory medicine leading to personalized medicine. This allows the increase in diagnostics and therapeutics focused on individuals rather than populations. In order to investigate whether laboratory medicine is ready to play a key role in the integration of personalized medicine in routine health care and set the state-of-the-art knowledge about personalized medicine and laboratory medicine in Europe, a questionnaire was constructed under the auspices of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) and the European Society of Pharmacogenomics and Personalised Therapy (ESPT). The answers of the participating laboratory medicine professionals indicate that they are aware that personalized medicine can represent a new and promising health model, and that laboratory medicine should play a key role in supporting the implementation of personalized medicine in the clinical setting. Participants think that the current organization of laboratory medicine needs additional/relevant implementations such as (i) new technological facilities in -omics; (ii) additional training for the current personnel focused on the new methodologies; (iii) incorporation in the laboratory of new competencies in data interpretation and counseling; and (iv) cooperation and collaboration among professionals of different disciplines to integrate information according to a personalized medicine approach.
Peroxisome proliferator-activated receptor α and γ agonists differently regulate classical and alternative macrophage activation
Authors: Paukkeri Erja-Leena , Pekurinen Antti , Moilanen Eeva
Published: May 2015

Peroxisome proliferator-activated receptor (PPAR) agonists, fibrates and thiazolidinediones, are commonly used drugs in the treatment of dyslipidemia and diabetes. Their targets, PPARα and PPARγ, have also been shown to have a role in the regulation of inflammatory responses linking metabolism and inflammation. In the present study we investigated the effects of PPAR agonists on macrophage activation. In addition to the proinflammatory classical activation, we also focused on interleukin (IL) 4 and 13 -induced alternative activation which is a significant macrophage phenotype in tissue repairing processes and in fibrosing diseases. PPARα agonists GW7647 and fenofibrate as well as PPARγ agonist GW1929 inhibited lipopolysaccharide-induced classical macrophage activation and production of the characteristic biomarkers of this phenotype, i.e. IL-6 and nitric oxide, in murine J774 macrophages. Remarkably, the PPARα agonists also inhibited IL-4 and IL-13 –induced expression of alternative activation markers arginase-1, fizz1 and mannose receptor 1 whereas the PPARγ agonist GW1929 enhanced their expression in J774 macrophages. The PPARα agonists GW7647 and fenofibrate also attenuated the production of alternative activation markers chemokine (C-C motif) ligand 13 and plateletderived growth factor in human THP-1 macrophages. The present findings show that PPARα and PPARγ agonists differently regulate classical and alternative macrophage phenotypes. Furthermore, PPARα activation was introduced as a novel concept to down-regulate alternative macrophage activation indicating that PPARα agonists have therapeutic potential in conditions associated with aberrant alternative macrophage activation such as fibrosing diseases.
HPLC method for the determination of the S- and R-diastereomers of telaprevir for treatment of patients with hepatitis C
Authors: Heinz Werner J. , Kuschak Dieter , Schirmer Diana , Grau Anna , Keller Daniela , Klinker Hartwig
Published: May 2015

Telaprevir (TVR) was approved by the FDA in May 2011 for the treatment of hepatitis C. This protease inhibitor converts into two diastereomers with significant difference in antiviral activity. Clinical efficacy has been correlated with serum concentrations. Therefore, a sensitive and selective high-performance liquid chromatographic method for the simultaneous determination of both clinically relevant diastereomers of TVR was developed. Linearity ranged from 20 to 10,000 ng/mL. The coefficients of variation were <7.3%, and accuracy was between −4.0 and 5.4%. In 105 clinical samples, both diastereomers of TVR had a high degree of correlation to each other, but concentrations showed a broad range and an increase during therapy.
Non-genetic inheritance in evolutionary theory - the importance of plant studies
Authors: Robertson Marta , Richards Christina
Published: May 2015

Emerging evidence points to a causal role for epigenetic variation in evolution, but evolutionary biologists have been reluctant to incorporate epigenetics into modern evolutionary theory. Part of this ambivalence comes from the assumption that epigenetic inheritance is only relevant to the evolution of plants, which is perpetuated by a comparative lack of evolutionary studies in animals. However, although most of the evidence for epigenetic inheritance comes from plants, plants and animals share many homologous epigenetic mechanisms, and plants provide a more tractable system for investigating the causal role of epigenetic mechanisms underlying phenotypic variation and its relationship with fitness. The insights from studies of epigenetic inheritance in plants may be applicable across a broad range of taxa once we establish commonalities and differences in epigenetic machinery. In this paper we present evidence for a role of epigenetic mechanisms in the evolutionary process and discuss common objections to incorporating epigenetics into evolutionary theory. This review is not exhaustive, but is meant to demonstrate that epigenetic inheritance can be incorporated into current evolutionary theory without overhauling its foundations.
Exploring the Dimensions of Nonprofit Competition through its Supplementary, Complementary, and Adversarial Relationships with Government
Authors: Derrick-Mills Teresa Marie
Published: May 2015

Nonprofits contribute to communities and society through service delivery, innovation, knowledge-building, and civic engagement. They frequently partner with and push government to better serve its citizens through relationships that have been characterized as supplementary, complementary, and adversarial (Young 2006). In all of these roles and relationships, nonprofits must compete for resources, time, and attention with other nonprofits, government entities, and for-profit organizations within communities, nationally, and internationally. Competition sometimes shapes and sometimes is shaped by public policies that affect the rules of the game. In this conceptual paper, we explore the dimensions of nonprofit competition and the implications for the nonprofit–government supplementary, complementary, and adversarial relationships.
Organoboranes and tetraorganoborates studied by 11B and 13C NMR spectroscopy and DFT calculations
Authors: Wrackmeyer Bernd
Published: May 2015

Care should be taken on recording the sometimes elusive 13C NMR signals for boron-bonded carbon atoms, since it is easy to extract information about coupling constants 1
J(13C,11B) by measuring the respective line widths of 13C(B-C) and 11B NMR signals. This information can be confirmed by quantum-chemical calculations [B3LYP (6-311+G(d,p) level of theory] of
n

J(13C,11B) in organoboranes and tetraorganoborates. For the latter, the signs for n = 2, 3, 4 were experimentally determined.
About alkali metal dicyanamides: syntheses, single-crystal structure determination, DSC/TG and vibrational spectra of KCs[N(CN)2]2 and NaRb2[N(CN)2]3 · H2O
Authors: Reckeweg Olaf , Wakabayashi Ryo H. , DiSalvo Francis J. , Schulz Armin , Schneck Christof , Schleid Thomas
Published: May 2015

Transparent colorless crystals of KCs[N(CN)2]2 and NaRb2[N(CN)2]3 · H2O were obtained by blending aqueous solutions of Na[N(CN)2] and RbF or KF, respectively. After evaporation of the water, the remaining solid was extracted with absolute ethanol and the solvent was allowed to evaporate at r. t.. KCs[N(CN)2]2 crystallizes in the space group C2/c (no. 15) with the cell parameters a = 1382.7(2), b = 998.1(1) and c = 1455.4(2) pm, and β = 118.085(4) °. The structure of NaRb2[N(CN)2]3 · H2O is exhibiting the space group P63/m (no. 176) with the cell parameters a = 705.98(7) and c = 1462.89(12) pm. Single-crystalline α-K[N(CN)2] was obtained while attempting to synthesize ‘NaK2[N(CN)2]3’, corroborating the results of previous X-ray powder diffraction experiments. Vibrational spectra and DSC/TGA analyses complete our results.
Tolerancia de los estudiantes de pregrado ante los comportamientos desviados en el aula de clase: un estudio comparativo
Authors: Avellaneda Suárez Jorge Luis
Published: May 2015

Los comportamientos desviados de los estudiantes a lo largo de su formación académica son más frecuentes de lo que se cree. De hecho, detrás del simple hecho de infringir una norma establecida por alguna institución educativa, hay una serie de construcciones sociales que se gestan alrededor de esta situación, y sobre esto es importante ahondar. En efecto, el enfoque del presente estudio es encontrar la postura y la tolerancia que tienen los estudiantes de dos Facultades diferentes frente al fraude académico, y tratar de encontrar las posibles causas de esa tolerancia ante las acciones desviadas.
 Además, se hará un énfasis especial en la Facultad de Administración, dadas la importancia y la relevancia que tienen los egresados de este programa académico en el desarrollo económico de un país.
Synthesis, Characterization and Antitumor Activity of 4-Ferrocenylpyridine-3, 5-Dicarbonitrile Derivatives and Sodium Polymeric Complexes Containing Carbanionic Ligands
Authors: Klimova E. , Sánchez J. , Flores M. , Cortez S. , Ramírez T. , Churakov A. , Martínez M.
Published: May 2015

The reactions of 2-cyano-3-ferrocenylacrylonitrile with malononitrile in a ROH/H2O medium in the presence of Na2CO3 afforded 6-alkoxy-2-amino-4-ferrocenylpyridine-3,5-dicarbonitriles, 6-alkoxy-2-amino-4-ferrocenyl-3-ferrocenyl-methyl-3,4-dihydropyridine-3,5-dicarbonitriles and Na+ polymeric complexes: {[Na+(2-ferrocenyl(tetracyano)propenyl)−L]∞ and [Na+(2-amino-3,5-dicyano-4-ferrocenyl-6-pyridyl-dicyanomethyl)−L]∞ where L = ethanol, methanol. Complexes with L = acetonitrile (c), dimethylformamide (d), acetone (e), ethyl acetate (f) were prepared by recrystallization. The structures of the compounds 4b and Na+ polymeric complexes 5c and 6d, e were established by the spectroscopic data and X-ray diffraction analysis. Two compounds 3a and 4a were tested in vitro against six human tumor cell lines U-251, PC-3, K-562, HCT-15, MCF-7 and SKLU-1 to assess their in vitro antitumor activity. The results suggest biological specificity towards PC-3, K-562 and HCT-15 cells for compound 3a, and towards PC-3 cell for compound 4a at doses 50 μM, which are lower than Cisplatin IC50′s in the three cell lines.
Microstructural Effects between AHSS Dissimilar Joints Using MIG and TIG Welding Process
Authors: Medina G.Y. Pérez , Padovani M. , Merlin M. , Pérez A.F. Miranda , Valdés F.A. Reyes
Published: May 2015

Gas tungsten arc welding-tungsten inert gas (GTAW-TIG) is focused in literature as an alternative choice for joining high strength low alloy steels; this study is performed to compare the differences between gas metal arc welding-metal inert gas (GMAW-MIG) and GTAW welding processes. The aim of this study is to characterize microstructure of dissimilar transformation induced plasticity steels (TRIP) and martensitic welded joints by GMAW and GTAW welding processes. It was found that GMAW process lead to relatively high hardness in the HAZ of TRIP steel, indicating that the resultant microstructure was martensite. In the fusion zone (FZ), a mixture of phases consisting of bainite, ferrite and small areas of martensite were present. Similar phase’s mixtures were found in FZ of GTAW process. The presence of these mixtures of phases did not result in mechanical degradation when the GTAW samples were tested in lap shear tensile testing as the fracture occurred in the heat affected zone. In order to achieve light weight these result are benefits which is applied an autogenous process, where it was shown that without additional weight the out coming welding resulted in a high quality bead with homogeneous mechanical properties and a ductile morphology on the fracture surface. Scanning electron microscopy (SEM) was employed to obtain information about the specimens that provided evidence of ductile morphology.
Study of GMAW Process Parameters on the Mechanisms of Wear in Contact Tips C12200 Alloy
Authors: López Luis A. , Perez Gladys Y. , Garcia Felipe J. , López Víctor H.
Published: May 2015

This paper focuses on the impact of process parameters of gas metal arc welding (GMAW) on the mechanisms of fail and wear present in the contact tips (CT), component located in the welding gun, when high strength low alloy (HSLA) steel is welded with ER70S - 0.045” copper coated electrode in manual mode. By means of chemical analysis the alloy was identified as C12200. It was also identified that the maximum temperature reached by the CT is 850° C. 30 samples were obtained that had different lifetime, which were analyzed by stereoscope and its behavior against wear was determined by using an equation of relative wear. Microstructural changes as recrystallization and grain growth undergone by these CT were also evidenced by light microscopy. In addition the changes in their mechanical properties such as decrease in their hardness to about of half that initially had. Finally some significant samples were analyzed by scanning electron microscopy (SEM); microanalysis was used to identify the exchange of matter leaving from the electrode in the CT and spatter into the hole of the component.
Structural and Optical Characterization of ZnO Nanofilms Deposited by CBD-AμW
Authors: Díaz-Reyes J. , Castillo-Ojeda R. S. , Flores-Mena J. E. , Martínez-Juárez J.
Published: May 2015

ZnO was grown by Chemical Bath Deposition technique activated by microwaves (CBD-AμW) on corning glass substrates. The ZnO structural and optical properties are studied as a function of the urea concentration in the growth solution. ZnO chemical stoichiometry was determined by Energy-dispersive X-ray spectroscopy (EDS). The XRD analysis and Raman scattering reveal that ZnO deposited thin films showed hexagonal polycrystalline phase wurtzite type. The Raman spectra present four main peaks associated to the modes E2high, (E2high-E2low), E2low and an unidentified vibrational band observed at 444, 338, 104 and 78 cm-1. The E2low mode involves mainly Zn atoms motion in the unit cell and the E2high mode is associated to oxygen motion. The observed emission peaks in the room temperature photoluminescence spectra are associated at vacancies of zinc and oxygen in the lattice.
Relation -between Nanostructural Changes and Macroscopic Effects during Reversible Temperature-Memory Effect under Stress-Free Conditions in Semicrystalline Polymer Networks
Authors: Nöchel U. , Kratz K. , Behl M. , Lendlein A.
Published: May 2015

Temperature-memory effects in polymers under stress-free conditions are typically limited to one way effects. Recently, crosslinked polymer networks comprising crystallizable domains, which were capable of a reversible temperature-memory effect (rTME) under stress-free conditions, were introduced. The utilization of crystallizable actuator domains (AD) and shape determining domains (SD) where related to two different temperature ranges of a single broad melting temperature transition in case of rTME. In this study we investigated the nanostructure of crosslinked poly[ethylene-co-(vinyl acetate)] cPEVA capable of rTME in situ during actuation cycles utilizing X-ray scattering techniques and related the changes on the nanoscale to effects on the macroscopic scale. It was observed that 23% of SD obtained at a separation temperature of 75 °C gave the highest reversible strain and when exceeding 80 °C only isotropic crystallization occurred and no rTME was observed. Furthermore, distances between oriented crystalline lamellae correlated to the macroscopic actuation during heating-cooling cycles, exhibiting long-periods from 14 to 17 nm as function of temperature.
Embedded Fiber Optic Sensors for In Situ and In-Operando Monitoring of Advanced Batteries
Authors: Schwartz Julian , Arakaki Kyle , Kiesel Peter , Raghavan Ajay , Sommer Wilko , Lochbaum Alexander , Ganguli Anurag , Hegyi Alex , Saha Bhaskar , Bae Chang-Jun , Hah HoeJin , Kim ChaeAh , Alamgir Mohamed
Published: May 2015

Our team is developing an optically-based smart monitoring system prototype targeting batteries for advanced battery applications such as hybrid and electric vehicles (EVs). The system concept envisions fiber optic (FO) sensors embedded within Lithium (Li)-ion batteries to measure parameters indicative of cell state in conjunction with our low-cost, compact optical wavelength-shift detection technology and intelligent algorithms to enable effective real-time performance management and optimized battery design. Towards these goals, we have successfully made functional prototypes of Li-ion pouch cells with FO sensors embedded within the electrode stack during cell fabrication. The strong, interesting signals from these FO sensors obtained over charge-discharge cycles offer valuable information and features to enable more accurate cell state-of-charge (SOC) and state-of-health (SOH) estimation, and better understand cell electrochemical and aging processes. This paper presents initial results from these prototype cells and compares the results from internal FO signals to earlier results reported by our team on purely external configurations where the FO sensors were attached to the cell skin.
Oxidation Induced Giant Modulation in the Luminescence of Colloidal Amorphous Porous Silicon Nanoparticles
Authors: El Demellawi Jehad K. , Anjum Dalaver H. , Chaieb Sahraoui
Published: May 2015

The emission of crystalline silicon nanoparticles as well as nanowires can be tuned by varying their diameters. The diameter selection is achieved via a difficult chemical procedure that necessitates filtration which cannot be easily scaled up. Herein, we report a novel approach for producing and tuning the emission of freestanding colloidal of amorphous porous silicon nanoparticles (which should not be confused with bulk amorphous silicon nor with porous silicon) via a controlled oxidation without relying on size of nanoparticles. This oxidation increases local strain in the disordered network that causes orbital interactions which modifies the band-gap but a new hybridization.
Mechanical Stretching of Mouse Calvarial Osteoblasts In Vitro Models Changes in MMP-2 and MMP-9 Expression at the Bone-Implant Interface
Authors: Nichols Richard A. , Niagro Frank D. , Borke James L. , Cuenin Michael F.
Published: May 2015

Bone to mechanical loading elicits a biological response that has clinical significance for several areas in dental medicine, including orthodontic tooth movement, tempromandibular joint disease, and endosseous dental implant osseointegration. Human orthopedic studies of failed hip implant sites have identified increased mRNA expression of several collagen-degrading matrix metalloproteinases (MMPs), while in vitro experiments have shown increases in MMP secretion after exposure to inflammatory mediators. This investigation evaluates the effects of mechanical deformation on in vitro osteoblasts by assessing changes in MMP gene expression and enzyme activity. We seeded mouse neonatal calvarial osteoblasts onto flexible 6-well plates and subjected to continuous cyclic mechanical stretching. The expression and activity of mRNA for several MMPs (2, 3, 9, and 10) was assessed. When subjected to mechanical stress in culture, only mRNA specific for MMP-9 was significantly increased compared to nonstretched controls (P < .005). Measurement of MMP activity by gelatin zymography demonstrated that none of the MMPs showed increased activity with stretching; however, MMP-2 activity decreased. Our results suggest that in response to stretch, MMP-2 responds rapidly by inhibiting conversion of a MMP-2 to the active form, while a slower up-regulation of MMP-9 may play a role in the long-term remodeling of extracellular matrix in response to continuous mechanical loading. This study suggests that the regulation of metalloproteinases at both the mRNA and protein level are important in the response of bone to mechanical stress.
Integrated Management Techniques for Long-Term Control of Giant Smutgrass (Sporobolus indicusvar.pyramidalis) in Bahiagrass Pasture in Florida
Authors: Rana Neha , Sellers Brent A. , Ferrell Jason A. , MacDonald Gregory E. , Silveira Maria L. , Vendramini J. M.
Published: May 2015

Smutgrass, a native of tropical Asia, is a perennial weed that affects many improved perennial grass pastures in Florida and throughout the southeastern United States. The two varieties of smutgrass predominant in Florida are small smutgrass and giant smutgrass. Three field experiments were conducted from 2008 to 2012 to evaluate the effect of integrated long-term management strategies using both cultural and herbicide inputs for giant smutgrass control in bahiagrass pastures. Burning did not have a significant impact on long-term control. In 2011, no differences were observed when hexazinone was integrated with tillage or hexazinone was combined with supplemental nitrogen compared with sequential or single applications of hexazinone. However, cultural treatments that preceded hexazinone application compared with those that received two sequential applications of hexazinone had lower smutgrass control 36 mo after treatment. Data indicate that a sequential application of hexazinone may be better than implementing tillage. Sequential hexazinone applications, when applied at 0.56 kg ai ha−1or greater, resulted in similar or increased control as compared with single applications. Collectively, these data suggest that sequential applications of hexazinone may be most effective for smutgrass management, and cultural techniques, including tillage, should be followed by hexazinone application the following year.
Competitive mechanisms change with ontogeny in coral‐dwelling gobies
Authors: Pereira Pedro H. Cipresso , Munday Philip L. , Jones Geoffrey P.
Published: May 2015

Recent theory suggests that a mix of lottery and niche processes can facilitate coexistence between competing species, but this has not yet been empirically tested. Previous research has suggested that a competitive lottery for space promotes coexistence between two ecologically similar species, Gobiodon histrio and Gobiodon erythrospilus. However, not all the assumptions of lottery competition have been tested, and patterns of habitat use by adults suggest niche partitioning. Here, we investigated the hypothesis that the mechanism of competition changes with ontogeny, with a lottery for space operating at settlement and niche partitioning occurring in adults. Patterns of resource use in the field were compared for juveniles and adults of the two species. Pelagic larval duration (PLD) and size‐at‐settlement was also estimated to determine if size differences at settlement could affect the outcome of competitive interactions among juveniles. Habitat preference and size‐based competitive ability were then tested for juveniles and adults in laboratory experiments. Finally, a transplant experiment was performed to test the fitness‐associated consequences of niche partitioning among adults and its implications for coexistence of the two species. G. histrio had a similar PLD (20.7 ± 2.0 days) to G. erythrospilus (18.5 ± 1.9 days), and there was no difference in size‐at‐settlement between the species. Juveniles of the two species had similar patterns of habitat use and similar competitive abilities, supporting the lottery mechanism at settlement. However, adults differ in their habitat use, supporting the prediction that resource partitioning increases with ontogeny. In laboratory experiments, adults of each species preferred colonies of Acropora nasuta. However, G. histrio was a superior competitor and prevented G. erythrospilus from using A. nasuta in >70% of the trials. In the field transplant experiment, G. erythrospilus (inferior competitor) suffered less of a fitness loss when occupying the non‐preferred coral (A. spathulata) compared with G. histrio, which could explain its ability to persist when displaced by the superior competitor. These results suggest that the competitive mechanism operating between the two Gobiodon species shifts from a lottery for space to niche partitioning through ontogeny, and that these two mechanisms of competitive coexistence are not mutually exclusive.
Plastic response of fearful prey to the spatiotemporal dynamics of predator distribution
Authors: Basille Mathieu , Fortin Daniel , Dussault Christian , Bastille-Rousseau Guillaume , Ouellet Jean-Pierre , Courtois Réhaume
Published: May 2015

Ecological theory predicts that the intensity of antipredator responses is dependent upon the spatiotemporal context of predation risk (the risk allocation hypothesis). However, most studies to date have been conducted over small spatial extents, and did not fully take into account gradual responses to predator proximity. We simultaneously collected spatially explicit data on predator and prey to investigate acute responses of a threatened forest ungulate, the boreal caribou (Rangifer tarandus), to the spatiotemporal dynamics of wolf (Canis lupus) distribution during spring. Movement analysis of GPS‐collared individuals from both species revealed high plasticity in habitat‐selection decisions of caribou. Female caribou avoided open areas and deciduous forests and moved relatively fast and toward foraging areas when wolves were closer than 2.5 km. Caribou also avoided food‐rich areas only when wolves were within 1 km. Our results bridge the gap between long‐term perceived risk and immediate flight responses by revealing dynamic antipredator tactics in response to predator proximity.
Soil processes drive seasonal variation in retention of 15N tracers in a deciduous forest catchment
Authors: Goodale Christine L. , Fredriksen Guinevere , Weiss Marissa S. , McCalley Carmody K. , Sparks Jed P. , Thomas Steven A.
Published: May 2015

Seasonal patterns of stream nitrate concentration have long been interpreted as demonstrating the central role of plant uptake in regulating stream nitrogen loss from forested catchments. Soil processes are rarely considered as important drivers of these patterns. We examined seasonal variation in N retention in a deciduous forest using three whole‐ecosystem 15N tracer additions: in late April (post‐snowmelt, pre‐leaf‐out), late July (mid‐growing‐season), and late October (end of leaf‐fall). We expected that plant 15N uptake would peak in late spring and midsummer, that immobilization in surface litter and soil would peak the following autumn leaf‐fall, and that leaching losses would vary inversely with 15N retention. Similar to most other 15N tracer studies, we found that litter and soils dominated ecosystem retention of added 15N. However, 15N recovery in detrital pools varied tremendously by season, with >90% retention in spring and autumn and sharply reduced 15N retention in late summer. During spring, over half of the 15N retained in soil occurred within one day in the heavy (mineral‐associated) soil fraction. During summer, a large decrease in 15N retention one week after addition coincided with increased losses of 15NO3− to soil leachate and seasonal increases in soil and stream NO3− concentrations, although leaching accounted for only a small fraction of the lost 15N (<0.2%). Uptake of 15N into roots did not vary by season and accounted for <4% of each tracer addition. Denitrification or other processes that lead to N gas loss may have consumed the rest. These measurements of 15N movement provide strong evidence for the dominant role of soil processes in regulating seasonal N retention and losses in this catchment and perhaps others with similar soils.
Mammalian phylogenetic diversity–area relationships at a continental scale
Authors: Mazel Florent , Renaud Julien , Guilhaumon François , Mouillot David , Gravel Dominique , Thuiller Wilfried
Published: May 2015

In analogy to the species–area relationship (SAR), one of the few laws in ecology, the phylogenetic diversity–area relationship (PDAR) describes the tendency of phylogenetic diversity (PD) to increase with area. Although investigating PDAR has the potential to unravel the underlying processes shaping assemblages across spatial scales and to predict PD loss through habitat reduction, it has been little investigated so far. Focusing on PD has noticeable advantages compared to species richness (SR), since PD also gives insights on processes such as speciation/extinction, assembly rules and ecosystem functioning. Here we investigate the universality and pervasiveness of the PDAR at continental scale using terrestrial mammals as study case. We define the relative robustness of PD (compared to SR) to habitat loss as the area between the standardized PDAR and standardized SAR (i.e., standardized by the diversity of the largest spatial window) divided by the area under the standardized SAR only. This metric quantifies the relative increase of PD robustness compared to SR robustness. We show that PD robustness is higher than SR robustness but that it varies among continents. We further use a null model approach to disentangle the relative effect of phylogenetic tree shape and nonrandom spatial distribution of evolutionary history on the PDAR. We find that, for most spatial scales and for all continents except Eurasia, PDARs are not different from expected by a model using only the observed SAR and the shape of the phylogenetic tree at continental scale. Interestingly, we detect a strong phylogenetic structure of the Eurasian PDAR that can be predicted by a model that specifically account for a finer biogeographical delineation of this continent. In conclusion, the relative robustness of PD to habitat loss compared to species richness is determined by the phylogenetic tree shape but also depends on the spatial structure of PD.
Population control of an overabundant species achieved through consecutive anthropogenic perturbations
Authors: Payo-Payo Ana , Oro Daniel , Igual José Manuel , Jover Lluís , Sanpera Carolina , Tavecchia Giacomo
Published: May 2015

The control of overabundant vertebrates is often problematic. Much work has focused on population‐level responses and overabundance due to anthropogenic subsidies. However, far less work has been directed at investigating responses following the removal of subsidies. We investigate the consequences of two consecutive perturbations, the closure of a landfill and an inadvertent poisoning event, on the trophic ecology (δ13C, δ15N, and δ34S), survival, and population size of an overabundant generalist seabird species, the Yellow‐legged Gull (Larus michahellis). We expected that the landfill closure would cause a strong dietary shift and the inadvertent poisoning a decrease in gull population size. As a long‐lived species, we also anticipated adult survival to be buffered against the decrease in food availability but not against the inadvertent poisoning event. Stable isotope analysis confirmed the dietary shift towards marine resources after the disappearance of the landfill. Although the survival model was inconclusive, it did suggest that the perturbations had a negative effect on survival, which was followed by a recovery back to average values. Food limitation likely triggered dispersal to other populations, while poisoning may have increased mortality; these two processes were likely responsible for the large fall in population size that occurred after the two consecutive perturbations. Life‐history theory suggests that perturbations may encourage species to halt existing breeding investment in order to ensure future survival. However, under strong perturbation pulses the resilience threshold might be surpassed and changes in population density can arise. Consecutive perturbations may effectively manage overabundant species.
Global‐scale environmental control of plant photosynthetic capacity
Authors: Ali Ashehad A. , Xu Chonggang , Rogers Alistair , McDowell Nathan G. , Medlyn Belinda E. , Fisher Rosie A. , Wullschleger Stan D. , Reich Peter B. , Vrugt Jasper A. , Bauerle William L. , Santiago Louis S. , Wilson Cathy J.
Published: May 2015

Photosynthetic capacity, determined by light harvesting and carboxylation reactions, is a key plant trait that determines the rate of photosynthesis; however, in Earth System Models (ESMs) at a reference temperature, it is either a fixed value for a given plant functional type or derived from a linear function of leaf nitrogen content. In this study, we conducted a comprehensive analysis that considered correlations of environmental factors with photosynthetic capacity as determined by maximum carboxylation (Vc,m) rate scaled to 25°C (i.e., Vc,25; μmol CO2·m−2·s−1) and maximum electron transport rate (Jmax) scaled to 25°C (i.e., J25; μmol electron·m−2·s−1) at the global scale. Our results showed that the percentage of variation in observed Vc,25 and J25 explained jointly by the environmental factors (i.e., day length, radiation, temperature, and humidity) were 2–2.5 times and 6–9 times of that explained by area‐based leaf nitrogen content, respectively. Environmental factors influenced photosynthetic capacity mainly through photosynthetic nitrogen use efficiency, rather than through leaf nitrogen content. The combination of leaf nitrogen content and environmental factors was able to explain ~56% and ~66% of the variation in Vc,25 and J25 at the global scale, respectively. Our analyses suggest that model projections of plant photosynthetic capacity and hence land–atmosphere exchange under changing climatic conditions could be substantially improved if environmental factors are incorporated into algorithms used to parameterize photosynthetic capacity in ESMs.
Fish‐derived nutrient hotspots shape coral reef benthic communities
Authors: Shantz Andrew A. , Ladd Mark C. , Schrack Elizabeth , Burkepile Deron E.
Published: May 2015

Animal‐derived nutrients play an important role in structuring nutrient regimes within and between ecosystems. When animals undergo repetitive, aggregating behavior through time, they can create nutrient hotspots where rates of biogeochemical activity are higher than those found in the surrounding environment. In turn, these hotspots can influence ecosystem processes and community structure. We examined the potential for reef fishes from the family Haemulidae (grunts) to create nutrient hotspots and the potential impact of these hotspots on reef communities. To do so, we tracked the schooling locations of diurnally migrating grunts, which shelter at reef sites during the day but forage off reef each night, and measured the impact of these fish schools on benthic communities. We found that grunt schools showed a high degree of site fidelity, repeatedly returning to the same coral heads. These aggregations created nutrient hotspots around coral heads where nitrogen and phosphorus delivery was roughly 10 and 7 times the respective rates of delivery to structurally similar sites that lacked schools of these fishes. In turn, grazing rates of herbivorous fishes at grunt‐derived hotspots were approximately 3 times those of sites where grunts were rare. These differences in nutrient delivery and grazing led to distinct benthic communities with higher cover of crustose coralline algae and less total algal abundance at grunt aggregation sites. Importantly, coral growth was roughly 1.5 times greater at grunt hotspots, likely due to the important nutrient subsidy. Our results suggest that schooling reef fish and their nutrient subsidies play an important role in mediating community structure on coral reefs and that overfishing may have important negative consequences on ecosystem functions. As such, management strategies must consider mesopredatory fishes in addition to current protection often offered to herbivores and top‐tier predators. Furthermore, our results suggest that restoration strategies may benefit from focusing on providing structure for aggregating fishes on reefs with low topographic complexity or focusing the restoration of nursery raised corals around existing nutrient hotspots.
The influence of habitat fragmentation on multiple plant–animal interactions and plant reproduction
Authors: Brudvig Lars A. , Damschen Ellen I. , Haddad Nick M. , Levey Douglas J. , Tewksbury Joshua J.
Published: May 2015

Despite broad recognition that habitat loss represents the greatest threat to the world's biodiversity, a mechanistic understanding of how habitat loss and associated fragmentation affect ecological systems has proven remarkably challenging. The challenge stems from the multiple interdependent ways that landscapes change following fragmentation and the ensuing complex impacts on populations and communities of interacting species. We confronted these challenges by evaluating how fragmentation affects individual plants through interactions with animals, across five herbaceous species native to longleaf pine savannas. We created a replicated landscape experiment that provides controlled tests of three major fragmentation effects (patch isolation, patch shape [i.e., edge‐to‐area ratio], and distance to edge), established experimental founder populations of the five species to control for spatial distributions and densities of individual plants, and employed structural equation modeling to evaluate the effects of fragmentation on plant reproductive output and the degree to which these impacts are mediated through altered herbivory, pollination, or pre‐dispersal seed predation. Across species, the most consistent response to fragmentation was a reduction in herbivory. Herbivory, however, had little impact on plant reproductive output, and thus we found little evidence for any resulting benefit to plants in fragments. In contrast, fragmentation rarely impacted pollination or pre‐dispersal seed predation, but both of these interactions had strong and consistent impacts on plant reproductive output. As a result, our models robustly predicted plant reproductive output (r2 = 0.52–0.70), yet due to the weak effects of fragmentation on pollination and pre‐dispersal seed predation, coupled with the weak effect of herbivory on plant reproduction, the effects of fragmentation on reproductive output were generally small in magnitude and inconsistent. This work provides mechanistic insight into landscape‐scale variation in plant reproductive success, the relative importance of plant–animal interactions for structuring these dynamics, and the nuanced nature of how habitat fragmentation can affect populations and communities of interacting species.
Pilot Research Study on the Provision of the Eye Movement Desensitization and Reprocessing Integrative Group Treatment Protocol With Female Cancer Patients
Authors: Jarero Ignacio , Artigas Lucina , Uribe Susana , García Laura Evelyn , Cavazos María Alicia , Givaudan Martha
Published: May 2015

The purpose of this research is to evaluate the effectiveness of the eye movement desensitization and reprocessing (EMDR) Integrative Group Treatment Protocol (EMDR-IGTP) in reducing posttraumatic stress disorder (PTSD) symptoms related to the diagnosis and treatment of different types of cancer in adult women. EMDR-IGTP intensive therapy was administered for 3 consecutive days, twice daily, to 24 adult women diagnosed with different types of cancer (cervical, breast, colon, bladder, and skin) who had PTSD symptoms related to their diagnosis and treatment. The data was analyzed using factorial ANOVA with the effects of the EMDR-IGTP evaluated with the Short PTSD Rating Interview as dependent variable and group (two groups of patients: active phase and follow-up phase of cancer treatment) and time (four time points) as independent variables. Post hoc analyses were carried out. Results showed significant main effects for time and group. No significant interaction was found. Results also showed an overall subjective improvement in the participants. This pilot study suggests that intensive administration of the EMDR-IGTP can be a valuable support for cancer patients with PTSD symptoms related to their diagnosis and treatment. Further research with randomized controlled studies is needed to demonstrate the effectiveness of EMDR-IGTP in this population.