bluuebunny/crossref_metadata_2025 huggingface dataset:
Music, Noise-Exclusion, and Learning
Authors: Chandrasekaran Bharath , Kraus Nina
Published: April 2010

CHILDREN WITH LANGUAGE-BASED LEARNING disorders show impaired processing of speech in challenging listening environments, suggesting a noise-exclusion deficit. Musical expertise induces neuroplastic changes throughout the nervous system, including sharpening of early sensory processing, improved linguistic ability, working memory, and source segregation—skills known to be crucial for speech in noise perception. Here we argue for the usefulness of music as an auditory training approach to improve speech perception in noise in individuals with broad noise-exclusion deficits.
Music in the Treatment of Affective Disorders: An Exploratory Investigation of a New Method for Music-Therapeutic Research
Authors: Koelsch Stefan , Offermanns Kristin , Franzke Peter
Published: April 2010

MUSIC LISTENING AND MAKING ACTIVATES A multitude of brain structures, the engagement of which is likely to have beneficial effects on the psychological and physiological health of individuals. We first briefly review functional neuroimaging experiments on music and emotion, showing that music-evoked emotions can change activity in virtually all core areas of emotional processing.We then enumerate social functions that are automatically and effortlessly engaged when humans make music. Engagement in these social functions fulfils basic human needs, is part of what makes us human, and is an important source for pleasure and happiness. Finally, we present a new method for music therapy, including an exploratory empirical study on effects of music making. Results show that the music making increased the mood of individuals compared to a control group. This music therapy method is promising in encouraging further development for the treatment of affective disorders, and can be used in both single- and double-blinded studies for empirical, evidence-based medical research.
Aberrant cortisol regulations in bilateral macronodular adrenal hyperplasia: a frequent finding in a prospective study of 32 patients with overt or subclinical Cushing's syndrome
Authors: Libé Rossella , Coste Joël , Guignat Laurence , Tissier Frédérique , Lefebvre Hervé , Barrande Gaëlle , Ajzenberg Christiane , Tauveron Igor , Clauser Eric , Dousset Bertrand , Bertagna Xavier , Bertherat Jérôme , Groussin Lionel
Published: April 2010

Context

ACTH-independent macronodular adrenal hyperplasia (AIMAH) is a rare and heterogeneous condition characterized by abnormal steroid production. Cortisol secretion can be regulated by aberrant hormone receptors.

Objective

A large series of patients with AIMAH were evaluated to provide information on the prevalence and profile of aberrant regulations, in relation with the functional status.

Design and patients

Thirty-two consecutive patients with AIMAH were prospectively studied: 10 had a Cushing's syndrome (CS), and 22 had a subclinical CS (SCS).

Methods

A baseline endocrine evaluation was followed by anin vivoprotocol in search of aberrant cortisol responses (seven provocative tests). An acute inhibition test with the somatostatin analog octreotide was also performed.

Results

At least one aberrant cortisol response was identified in 28 of 32 (87%) patients. The overall prevalence of aberrant responses was independent of the functional status. Responses to the upright posture and to metoclopramide were frequently observed (67 and 56% respectively). A glucagon response was frequently observed in the SCS group (58%). A cortisol inhibition by octreotide was specifically found in the three CS patients who positively responded to the mixed meal, and was observed also in 12 of 13 (92%) patients with SCS.

Conclusions

Cortisol responses indicative of aberrant receptor expression were highly prevalent in AIMAH. Thorough phenotyping of AIMAH may help uncover the underlying pathophysiology.
Prevalence of knee osteoarthritis in Hungary. Study conducted in a representative Hungarian population
Authors: Horváth Gábor , Koroknai Gabriella , Ács Barnabás , Than Péter , Bellyei Árpád , Illés Tamás
Published: April 2010

A szerzők korábbi közleményükben beszámoltak reprezentatív magyarországi mintán végzett felmérésükről, amelyben a degeneratív ízületi panaszok, így a térdpanaszok gyakoriságát vizsgálták.
Célkitűzés:
ezt követően, e közlemény tárgyát képezve, céljuk ambuláns klinikai és radiológiai vizsgálat keretén belül, nemzetközileg elfogadott standard pontrendszerek felhasználásával a betegek panaszainak objektivizálása, és a térdízületi arthrosis előfordulási gyakoriságának meghatározása.
Módszer:
korábbi kérdőíves felmérésük mozgásszervi panaszokkal bíró és felülvizsgálatba beleegyezését adó 2422 fős beteganyagot alapul véve megkeresésükre 682-en (244 férfi, 438 nő) jelentek meg klinikai felülvizsgálatra. Az anamnézis, az antropometriai paraméterek és a mozgásszervi státus felmérésen túlmenően a térdízületre vonatkozóan a szerzők meghatározták a knee society score-t, a vizuális analóg fájdalomskála értékét, a kétirányú térdröntgenfelvételeken az ízületi rés szélességét mérték, Kellgren–Lawrence szerinti radiológiai kiértékelést végeztek, majd ennek kritériumrendszerét figyelembe véve meghatározták a térdízületi arthrosis előfordulási gyakoriságát.
Eredmények:
a fent említett 682 főnél 676 esetben volt radiológiai kiértékelés lehetséges. Térdízületi arthrosist 91 esetben (13,3%), előrehaladott arthrosist 20 esetben (2,9%) állapítottak meg. Ezt követően a negatív és az arthrosis által érintett betegek funkcionális paramétereit hasonlították össze. Mind a knee society score, mind a vizuális analóg fájdalomskála értékei szignifikánsan rosszabb értékeket mutattak ez utóbbi csoportban (p<0,05). A testtömegindexet vizsgálva szintén szignifikánsan magasabb értékeket találtak az arthrosisos csoportban.
Következtetések:
a szerzők a hazai irodalomban első alkalommal számolnak be radiológiailag is igazolt térdízületi arthrosisprevalenciáról. Az életkor és az emelkedett BMI térdízületi arthrosisban játszott szerepe vizsgálataik alapján bizonyított. A felmerés részleteinek ismertetésen túl a szerzők áttekintik a téma hazai és nemzetközi irodalmát.
Author-overdose. When will we come clean? – asks the medical librarian
Authors: Berhidi Anna , Csajbók Edit , Vasas Lívia
Published: April 2010

Jelen tanulmány a szerzői etika fontosságára szeretné felhívni a figyelmet. Ennek szükségszerűségét az mutatja, hogy napjainkban egyre inkább elterjedőben vannak a többszerzős, akár 10–12 szerzős közlemények is. A cikk első fele a szerzői szám változását vizsgálja négy folyóiratban – JAMA, Nature, Lancet és a Science – 1975-től 2009-ig, főbb dokumentumtípusonként: tudományos cikk (article), szerkesztőségi anyag (editorial material), levél (letter) és összefoglaló cikk (review). Ezek a változások igen hasonlók mind a 4 lapban. A tudományos cikk szerzői száma változott a legjelentősebben, a 34 év alatt a 4-szeresére emelkedett. Az esetleges összefüggés a várható idézettség és a szerzői szám változása között nem igazolható az elemzés alapján. A cikkenkénti szerzői szám növekedése több visszaélést is magában rejthet. Jelen közlemény az International Committee of Medical Journal Editors iránymutatása szerzőségi etikára vonatkozó részét emeli ki, amely segíthet az anomáliák visszaszorításában. Néhány külföldi, illetve hazai élet- és orvostudományi folyóiratot elemezve kiderül, hogy míg előbbiek igyekeznek a fő iránymutatókat követni, a 16 vizsgált magyar folyóirat közül csupán 4 hívja fel a figyelmet a szerzőségi etikával kapcsolatos kérdésekre. Ennek a témának a gyakorlati megoldása még várat magára.
Twenty five years of HIV virus
Authors: Nagy Károly , Horváth Attila
Published: April 2010

A HIV-vírus azonosításának 25. évfordulója kapcsán a hazai AIDS-ellenes küzdelemben kezdetektől részt vevő virológus és klinikus szerzők áttekintik a vírus felfedezésének, kimutatásának jelentőségét, a diagnosztika erre alapuló fejlődését, ami lehetővé tette a hatékony antivirális kezelés bevezetését. Kitérnek az epidemiológiai, társadalmi vonatkozásokra is, és részletesen taglalják a HIV/AIDS járvány magyarországi eseményeinek kronológiáját, az első HIV-fertőzöttek és AIDS-betegek kimutatásától a rendszeres országos szűrővizsgálatok és gondozási hálózat megteremtésén át a gyógyszerrezisztens mutánsok és afrikai HIV-vírustörzsek nemrégiben kimutatott hazai megjelenéséig. További teendőket sürgetnek világszerte – és hazánkban is – az ember mint gazdaszervezet és a HIV közötti kölcsönhatások jobb megértésére a gyógyítás érdekében. Ehhez világszerte politikai segítségnyújtásra, jelentős mértékű, hosszú távú anyagi támogatásra, megfelelő tudományos szintű és közegészségügyi vonatkozású nézetekre, valamint a társadalom egészének közreműködésére is szükség van.
Cryoballon isolation of the pulmonary veins in atrial fibrillation: Mid-term results after the first 55 patients
Authors: Tóth Zsuzsanna , Nagy-Baló Edina , Kertész Attila , Clemens Marcell , Herczku Csaba , Tint Diana , Kun Csaba , Édes István , Csanádi Zoltán
Published: April 2010

A pitvarfibrilláció transzkatéteres kezelésére számos rádiófrekvenciás hőablatión alapuló technikát dolgoztak ki az utóbbi 10 év során. Újabban a fagyasztással, a pulmonalis vénák krioballonos izolálásával elért eredmények a rádiófrekvenciás technikákéhoz hasonló hatékonyságot mutatnak az életet leginkább veszélyeztető szövődmények csökkenése mellett. Dolgozatunkban saját eredményeinkről számolunk be a mintegy egy év alatt végzett krioballon-ablatio alapján az első 55 betegen.
Módszer:
a beavatkozást panaszos, gyógyszerrefrakter, többnyire paroxysmalisan pitvarfibrilláló betegeken végeztük, akiknek lényeges szervi szívbaja nem volt. Minden esetben az összes pulmonalis véna felkeresésére és izolálására törekedtünk 28 mm átmérőjű, dupla falú ballonkatéter használatával, ami a pulmonalis vénaszájadék közelében felfújva a kerülete mentén a bal pitvari szövetet akár –70 Celsius-fokig hűtve megszünteti annak elektromos aktivitását. A beavatkozás alatt heparint, utána orális antikoagulánst alkalmaztunk. A fél éves utánkövetés során EKG-t, 24 órás EKG-Holtert és transztelefonos EKG-monitort használtunk a ritmus monitorozására.
Eredmények:
55 betegen (18 nő; életkor 56±33,64 év) 192 pulmonalis véna közül 165 (86%) izolációját sikerült elérnünk a beavatkozás során. Valamennyi pulmonalis vénát 37 betegben (67%) sikerült izolálni. A beavatkozási idő 155,67±100,66 perc (átlag±SD), az átvilágítási idő 34,04±31,89 perc volt. A 6 hónapos utánkövetésnél 34 beteg közül 24-nél (70%) sikerült teljes aritmiamentességet (17 beteg) vagy a ritmuszavar szignifikáns csökkenését (7 beteg) elérnünk.
Következtetések:
kezdeti tapasztalataink alapján a krioballonos pulmonalis vénaizolálás a rádiófrekvenciás ablatiónál egyszerűbb módszer, ahhoz hasonló eredményességgel a pitvarfibrilláció kezelésére.
Tetragonal Phase in Ge Doped HfO2 Films on Si Investigated by X-ray Absorption Spectroscopy
Authors: Miotti Leonardo , Paz Bastos Karen , Radtke Cláudio , Lucovsky Gerald
Published: April 2010

The stabilization of the tetragonal phase of 5 nm thick HfO2 films by Ge doping is investigated using x-ray absorption spectroscopy around O and Ge Kedges and by Rutherford backscattering spectrometry. We show that Ge concentrations higher than ˜5at.% are not stable during rapid thermal anneal at temperatures as low as 750°C and that the tetragonal phase of HfO2 is achieved at this Ge concentration.
Molecular Beam Epitaxy Growth of High Mobility Compound Semiconductor Devices for Integration with Si CMOS
Authors: Lubyshev Dmitri , Fastenau Joel M. , Wu Ying , Synder Andrew , Liu Amy W. K. , Bulsara Mayank T. , Fitzgerald Eugene A. , Urteaga Miguel , Ha Wonill , Bergman Joshua , Choe M. J. , Brar Bobby , Hoke William E. , LaRoche Jeffrey R. , Torabi Abbas , Kazior Thomas E. , Smith David , Clark David , Thompson Robin F. , Drazek Charlotte , Daval Nicolas , Benaissa Lamine , Augendre Emmanuel
Published: April 2010

We report on a direct epitaxial growth approach for the heterogeneous integration of high speed III-V devices with Si CMOS logic on a common Si substrate. InP-based heterojunction bipolar transistor (HBTs) structures were successfully grown on patterned Si-on-Lattice-Engineered-Substrate (SOLES) substrates using molecular beam epitaxy. DC and RF performance similar to those grown on lattice-matched InP were achieved in growth windows as small as 15×15μm2. This truly planar approach allows tight device placement with InP-HBTs to Si CMOS transistors separation as small as 2.5 μm, and the use of standard wafer level multilayer interconnects. A high speed, low power dissipation differential amplifier was designed and fabricated, demonstrating the feasibility of using this approach for high performance mixed signal circuits such as ADCs and DACs.
Conductive Atomic Force Microscopy and Scanning Impedance Microscopy for the Imaging of Electrical Domain in CaCu3Ti4O12 Perovskite Oxide
Authors: Lo Nigro Raffaella , Fiorenza Patrick , Raineri Vito
Published: April 2010

Electrical characterization of CaCu3Ti4O12 (CCTO) ceramics with scanning probe based techniques has been carried out. In particular, conductive atomic force microscopy (C-AFM) and scanning impedance microscopy (SIM) have been used to demonstrate the presence, shape and size in CCTO ceramics of the different electrically domains, both at the grain boundaries and within the grains. The electrical characteristics of single grains and of single domains have been evaluated and it has been observed that the conductive grains are surrounded by insulating grain boundaries.
Rapid Thermal Annealing of Amorphous Silicon Thin Films Grown by Electron Cyclotron Resonance Chemical Vapor Deposition
Authors: Lin Pei-Yi , Wu Ping-Jung , Chen I-Chen
Published: April 2010

Hydrogenated amorphous silicon (a-Si:H) thin films were deposited on pre-oxidized Si wafers by electron cyclotron resonance chemical vapor deposition (ECRCVD). The rapid thermal annealing (RTA) treatments were applied to the as-grown samples in nitrogen atmosphere, and the temperature range for the RTA process is from 450 to 950 °C. The crystallization and grain growth behaviors of the annealed films were investigated by Raman spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). The onset temperature for the crystallization and grain growth is around 625 ∼ 650°C. The crystalline fraction of annealed a-Si:H films can reach ∼80%, and a grain size up to 17 nm could be obtained from the RTA treatment at 700 °C. We found that the crystallization continues when the grain growth has stopped.
Wafer Bonding for Backside Illuminated CMOS Image Sensors Fabrication
Authors: Dragoi Viorel , Mittendorfer Gerald , Filbert Alexander , Wimplinger Markus
Published: April 2010

Backside illuminated CMOS image sensors were developed in order to encompass the pixel area limitation due to metal interconnects. In this technology the fully processed CMOS wafer is bonded to a blank carrier wafer and then back-thinned in order to open the photosensitive sensor area. The process flows of the two main competing wafer bonding technologies used for this manufacturing process (adhesive bonding and low temperature plasma activated direct wafer bonding with polymer layers) will be reviewed.
Mechanical and Electrical Properties of Electroplated Copper Thin Films Used for Thin Film Interconnection
Authors: Naokazu Murata , Tamakawa Kinji , Suzuki Ken , Miura Hideo
Published: April 2010

Micro-texture dependence of both the mechanical and electrical properties of electroplated copper thin films was discussed experimentally considering the change of their micro texture caused by thermal history after the electroplating. Both the static and fatigue strength of the films changed drastically depending on the micro texture and it was found that there were two fatigue fracture modes in the films. One was a typical ductile intragranular fracture and the other was brittle intergranular one. The reason for the variation of the strength of the electroplated copper thin films was attributed to the variation of the average grain size and the characteristics of grain boundaries. In addition, the electrical reliability of the electroplated copper interconnections was discussed under electromigration tests. Though abrupt fracture mode due to the local fusion appeared in the as-electroplated films, the life of the interconnections was improved significantly after the annealing at temperatures high than 200°C. Typical change of the surface morphology of the film, i.e., the formation of voids and hillocks were observed on their surfaces after the annealing. This was also caused by the change of the micro texture from fine grains with porous grain boundaries to coarsened columnar grains with rigid grain boundaries. However, the stress-induced migration appeared in the annealed narrow interconnections, in particular. This was because of high tensile residual stress occurred in the film due to the constraint of the shrinkage of the films by rigid oxide around them. These results clearly indicated that the control of both the micro-texture and residual stress is indispensable for improving the reliability of the interconnectins.
Effective Wavelength Conversion from Near-UV to Red for Photovoltaics: Potential of Transparent YVO4:Bi3+,Eu3+ Nanophosphor Film
Authors: Takeshita Satoru , Nakayama Kenji , Isobe Tetsuhiko , Sawayama Tomohiro , Niikura Seiji
Published: April 2010

The authors prepared a near-UV to red wavelength conversion thick film containing 38.8 wt% of YVO4:Bi3+,Eu3+ nanoparticles of 10.8 ± 1.6 nm in size. This nanoparticle film shows a high transparency in the visible region, e.g., the transmittance at 619 nm is ∼ 96% irrespective of the film thickness. The photoluminescence intensity at 619 nm corresponding to the f-f transition of Eu3+ for this nanoparticle film increases with increasing the film thickness up to 400 μm, whereas that of the film containing micron-sized particles reaches the maximum at the film thickness of ∼ 40 μm. On the other hand, YVO4:Bi3+,Eu3+ nanoparticles have a sufficient photostability for practical use over 15 years outside, as confirmed by the light fastness test. These results suggest that the transparent film of YVO4:Bi3+,Eu3+ nanoparticles are potentially applicable to the spectral convertor for photovoltaic cells from the aspects of low light-scattering loss and high photostability.
Imaging of persistent cAMP signaling by internalized G protein-coupled receptors
Authors: Calebiro Davide , Nikolaev Viacheslav O , Lohse Martin J
Published: April 2010

G protein-coupled receptors (GPCRs) are the largest family of plasma membrane receptors. They mediate the effects of several endogenous cues and serve as important pharmacological targets. Although many biochemical events involved in GPCR signaling have been characterized in great detail, little is known about their spatiotemporal dynamics in living cells. The recent advent of optical methods based on fluorescent resonance energy transfer allows, for the first time, to directly monitor GPCR signaling in living cells. Utilizing these methods, it has been recently possible to show that the receptors for two protein/peptide hormones, the TSH and the parathyroid hormone, continue signaling to cAMP after their internalization into endosomes. This type of intracellular signaling is persistent and apparently triggers specific cellular outcomes. Here, we review these recent data and explain the optical methods used for such studies. Based on these findings, we propose a revision of the current model of the GPCR–cAMP signaling pathway to accommodate receptor signaling at endosomes.
Loss of functional diversity of ant assemblages in secondary tropical forests
Authors: Bihn Jochen H. , Gebauer Gerhard , Brandl Roland
Published: April 2010

Secondary forests and plantations increasingly dominate the tropical wooded landscape in place of primary forests. The expected reduction of biodiversity and its impact on ecological functions provided by these secondary forests are of major concern to society and ecologists. The potential effect of biodiversity loss on ecosystem functioning depends largely on the associated loss in the functional diversity of animal and plant assemblages, i.e., the degree of functional redundancy among species. However, the relationship between species and functional diversity is still poorly documented for most ecosystems. Here, we analyze how changes in the species diversity of ground‐foraging ant assemblages translate into changes of functional diversity along a successional gradient of secondary forests in the Atlantic Forest of Brazil. Our analysis uses continuous measures of functional diversity and is based on four functional traits related to resource use of ants: body size, relative eye size, relative leg length, and trophic position. We find a strong relationship between species and functional diversity, independent of the functional traits used, with no evidence for saturation in this relationship. Recovery of species richness and diversity of ant assemblages in tropical secondary forests was accompanied by a proportional increase of functional richness and diversity of assemblages. Moreover, our results indicate that the increase in functional diversity along the successional gradient of secondary forests is primarily driven by rare species, which are functionally unique. The observed loss of both species and functional diversity in secondary forests offers no reason to believe that the ecological functions provided by secondary forests are buffered against species loss through functional redundancy.
Algal blooms and the nitrogen‐enrichment hypothesis in Florida springs: evidence, alternatives, and adaptive management
Authors: Heffernan James B. , Liebowitz Dina M. , Frazer Thomas K. , Evans Jason M. , Cohen Matthew J.
Published: April 2010

Contradictions between system‐specific evidence and broader paradigms to explain ecosystem behavior present a challenge for natural resource management. In Florida (USA) springs, increasing nitrate (NO3−) concentrations have been implicated as the cause of algal overgrowth via alleviation of N‐limitation. As such, policy and management efforts have centered heavily on reduction of nitrogen (N) loads. While the N‐limitation hypothesis appears well founded on broadly supported aquatic eutrophication models, several observations from Florida springs are inconsistent with this hypothesis in its present simplified form. First, NO3− concentration is not correlated with algal abundance across the broad population of springs and is weakly negatively correlated with primary productivity. Second, within individual spring runs, algal mats are largely confined to the headwater reaches within 250 m of spring vents, while elevated NO3− concentrations persist for several kilometers or more. Third, historic observations suggest that establishment of macroalgal mats often lags behind observed increases in NO3− by more than a decade. Fourth, although microcosm experiments indicate high thresholds for N‐limitation of algae, experiments in situ have demonstrated only minimal response to N enrichment. These muted responses may reflect large nutrient fluxes in springs, which were sufficient to satisfy present demand even at historic concentrations. New analyses of existing data indicate that dissolved oxygen (DO) has declined dramatically in many Florida springs over the past 30 years, and that DO and grazer abundance are better predictors of algal abundance in springs than are nutrient concentrations. Although a precautionary N‐reduction strategy for Florida springs is warranted given demonstrable effects of nutrient enrichment in a broad suite of aquatic systems worldwide, the DO–grazer hypothesis and other potential mechanisms merit increased scientific scrutiny. This case study illustrates the importance of an adaptive approach that explicitly evaluates paradigms as hypotheses and actively seeks alternative explanations.
Predicting global change effects on forest biomass and composition in south‐central Siberia
Authors: Gustafson Eric J. , Shvidenko Anatoly Z. , Sturtevant Brian R. , Scheller Robert M.
Published: April 2010

Multiple global changes such as timber harvesting in areas not previously disturbed by cutting and climate change will undoubtedly affect the composition and spatial distribution of boreal forests, which will, in turn, affect the ability of these forests to retain carbon and maintain biodiversity. To predict future states of the boreal forest reliably, it is necessary to understand the complex interactions among forest regenerative processes (succession), natural disturbances (e.g., fire, wind, and insects), and anthropogenic disturbances (e.g., timber harvest). We used a landscape succession and disturbance model (LANDIS‐II) to study the relative effects of climate change, timber harvesting, and insect outbreaks on forest composition, biomass (carbon), and landscape pattern in south‐central Siberia. We found that most response variables were more strongly influenced by timber harvest and insect outbreaks than by the direct effects of climate change. Direct climate effects generally increased tree productivity and modified probability of establishment, but indirect effects on the fire regime generally counteracted the direct effects of climate on forest composition. Harvest and insects significantly changed forest composition, reduced living aboveground biomass, and increased forest fragmentation. We concluded that: (1) Global change is likely to significantly change forest composition of south‐central Siberian landscapes, with some changes taking ecosystems outside the historic range of variability. (2) The direct effects of climate change in the study area are not as significant as the exploitation of virgin forest by timber harvest and the potential increased outbreaks of the Siberian silk moth. (3) Novel disturbance by timber harvest and insect outbreaks may greatly reduce the aboveground living biomass of Siberian forests and may significantly alter ecosystem dynamics and wildlife populations by increasing forest fragmentation.
Linking optimization and ecological models in a decision support tool for oyster restoration and management
Authors: North E. W. , King D. M. , Xu J. , Hood R. R. , Newell R. I. E. , Paynter K. , Kellogg M. L. , Liddel M. K. , Boesch D. F.
Published: April 2010

Restoration of ecologically important marine species and habitats is restricted by funding constraints and hindered by lack of information about trade‐offs among restoration goals and the effectiveness of alternative restoration strategies. Because ecosystems provide diverse human and ecological benefits, achieving one restoration benefit may take place at the expense of other benefits. This poses challenges when attempting to allocate limited resources to optimally achieve multiple benefits, and when defining measures of restoration success. We present a restoration decision‐support tool that links ecosystem prediction and human use in a flexible “optimization” framework that clarifies important restoration trade‐offs, makes location‐specific recommendations, predicts benefits, and quantifies the associated costs (in the form of lost opportunities). The tool is illustrated by examining restoration options related to the eastern oyster, Crassostrea virginica, which supported an historically important fishery in Chesapeake Bay and provides a range of ecosystem services such as removing seston, enhancing water clarity, and creating benthic habitat. We use an optimization approach to identify the locations where oyster restoration efforts are most likely to maximize one or more benefits such as reduction in seston, increase in light penetration, spawning stock enhancement, and harvest, subject to funding constraints and other limitations. This proof‐of‐concept Oyster Restoration Optimization model (ORO) incorporates predictions from three‐dimensional water quality (nutrients–phytoplankton–zooplankton–detritus [NPZD] with oyster filtration) and larval transport models; calculates size‐ and salinity‐dependent growth, mortality, and fecundity of oysters; and includes economic costs of restoration efforts. Model results indicate that restoration of oysters in different regions of the Chesapeake Bay would maximize different suites of benefits due to interactions between the physical characteristics of a system and nonlinear biological processes. For example, restoration locations that maximize harvest are not the same as those that would maximize spawning stock enhancement. Although preliminary, the ORO model demonstrates that our understanding of circulation patterns, single‐species population dynamics and their interactions with the ecosystem can be integrated into one quantitative framework that optimizes spending allocations and provides explicit advice along with testable predictions. The ORO model has strengths and constraints as a tool to support restoration efforts and ecosystem approaches to fisheries management.
Spatiotemporal dynamics of lianas during 50 years of succession to temperate forest
Authors: Ladwig Laura M. , Meiners Scott J.
Published: April 2010

Although they are important components of forest communities, the general ecology and spatiotemporal patterns of temperate lianas during forest regeneration are largely unknown. The dependence of lianas on other plants for physical support makes them a potentially important driver of community dynamics. We examined 50 years of vegetation data from an old‐field succession study to determine the dynamics and community controls on liana expansion within the Piedmont region of New Jersey, USA. Four lianas, Lonicera japonica, Parthenocissus quinquefolia, Toxicodendron radicans, and Vitis spp., occurred in enough abundance for detailed analyses. In general, liana cover peaked during mid‐succession (20–30 years post‐abandonment) when community composition was mostly herbaceous with scattered trees and shrubs. Liana cover began to decrease as trees became dominant and the canopy closed. Temporal patterns of cover dynamics of abundant species indicated three early‐ and one late‐successional liana species within the community. In contrast to cover, frequency of lianas increased throughout succession, indicating that liana populations persisted despite dramatic declines in cover for the three early‐successional species. Temporal dynamics between native and nonnative lianas were similar but spatially distinct as cover of native species dispersed and expanded near the forest edge while the nonnative species preferentially grew far from the forest. These dynamics indicate that successional processes may ultimately lead to the decline of most lianas. However, the persistence of lianas as high numbers of suppressed individuals suggests that they may rebound quickly following canopy disturbance.
Reinforcing abiotic and biotic time constraints facilitate the broad distribution of a generalist with fixed traits
Authors: Greig Hamish S. , Wissinger Scott A.
Published: April 2010

Many species are habitat specialists along environmental gradients as a result of contrasting selection pressures, but others maintain broad distributions along such gradients. Phenotypic plasticity explains the persistence of some generalists, but not the broad distributions of species with fixed traits. We combined comparative and experimental data to investigate the role of multiple selection pressures on the distribution of a cased caddisfly (Asynarchus nigriculus) across a pond permanence gradient in the Mexican Cut Nature Preserve, Elk Mountains, Colorado, USA. Rapid development in this species facilitates the exploitation of short‐duration vernal pools. Comparative data document that slowly growing individuals die from desiccation, suggesting an ongoing selection for rapid development. Surprisingly, development is as fast or faster in long‐duration, autumnal ponds where emergence occurs long before drying, and overlaps with the appearance of beetle (Dytiscus) predators. In field experiments we found that the last two instars of beetle larvae pose a significant mortality threat to Asynarchus, but that threat declines after caddisfly pupation. In natural populations, the caddisflies pupate and emerge just as large beetle instars appear in the ponds. Experimental manipulation of caddisfly size suggests that rapid development in autumnal ponds will both facilitate intraguild predation on other caddisflies and reduce Asynarchus cannibalism. Both types of caddisfly interactions should have a positive feedback effect on rapid development via a protein supplement to their detrital diet. All of these biotic time constraints should select for rapid Asynarchus development in autumnal habitats, despite relaxed drying time constraints. Asynarchus did not display flexible antipredator responses to beetles (no changes in activity rates, morphology, or development), suggesting that the traits that lead to rapid development are fixed, regardless of habitat type and presence of predators. We propose that different, but convergent, selection pressures across different habitat types have led to fixed specialized traits that enable a broad distribution along this environmental gradient. These selection pressures are dependent on the relative phenologies of interacting species and appear to trump the trade‐offs between other types of physical and biotic constraints across habitats.
Water quality as a regional driver of coral biodiversity and macroalgae on the Great Barrier Reef
Authors: De'ath Glenn , Fabricius Katharina
Published: April 2010

Degradation of inshore coral reefs due to poor water quality is a major issue, yet it has proved difficult to demonstrate this linkage at other than local scales. This study modeled the relationships between large‐scale data on water clarity and chlorophyll and four measures of reef status along the whole Great Barrier Reef, Australia (GBR; 12–24° S). Four biotic groups with different trophic requirements, namely, the cover of macroalgae and the taxonomic richness of hard corals and phototrophic and heterotrophic octocorals, were predicted from water quality and spatial location. Water clarity and chlorophyll showed strong spatial patterns, with water clarity increasing more than threefold from inshore to offshore waters and chlorophyll decreasing approximately twofold from inshore to offshore and approximately twofold from south to north. Richness of hard corals and phototrophic octocorals declined with increasing turbidity and chlorophyll, whereas macroalgae and the richness of heterotrophic octocorals increased. Macroalgal cover experienced the largest water quality effects, increasing fivefold with decreasing water clarity and 1.4‐fold with increasing chlorophyll. For each of the four biota, ∼45% of variation was predictable, with water quality effects accounting for 18–46% of that variation and spatial effects accounting for the remainder. Effects were consistent with the trophic requirements of the biota, suggesting that both macroalgal cover and coral biodiversity are partially controlled by energy supply limitation. Throughout the GBR, mean annual values of >10 m Secchi disk depth (a measure of water clarity) and <0.45 g/L chlorophyll were associated with low macroalgal cover and high coral richness, indicating these values to be potentially useful water quality guidelines. The models predict that on the 22.8% of GBR reefs where guideline values are currently exceeded, water quality improvement, e.g., by minimizing agricultural runoff, should reduce macroalgal cover on average by 39% and increase the richness of hard corals and phototrophic octocorals on average by 16% and 33%, respectively (all else being equal). Such guidelines may help focus efforts to implement effective pollution reduction and integrated coastal management policies for the GBR and other Indo‐Pacific coral reefs.
Net mitigation potential of straw return to Chinese cropland: estimation with a full greenhouse gas budget model
Authors: Lu Fei , Wang Xiaoke , Han Bing , Ouyang Zhiyun , Duan Xiaonan , Zheng Hua
Published: April 2010

Based on the carbon–nitrogen cycles and greenhouse gas (GHG) mitigation and emission processes related to straw return and burning, a compound greenhouse gas budget model, the “Straw Return and Burning Model” (SRBM), was constructed to estimate the net mitigation potential of straw return to the soil in China. As a full GHG budget model, the SRBM addressed the following five processes: (1) soil carbon sequestration, (2) mitigation of synthetic N fertilizer substitution, (3) methane emission from rice paddies, (4) additional fossil fuel use for straw return, and (5) CH4 and N2O emissions from straw burning in the fields. Two comparable scenarios were created to reflect different degrees of implementation for straw return and straw burning. With GHG emissions and mitigation effects of the five processes converted into global warming potential (GWP), the net GHG mitigation was estimated. We concluded that (1) when the full greenhouse gas budget is considered, the net mitigation potential of straw return differs from that when soil carbon sequestration is considered alone; (2) implementation of straw return across a larger area of cropland in 10 provinces (i.e., Shanghai, Jiangsu, Zhejiang, Fujian, Jiangxi, Hubei, Hunan, Guangdong, Guangxi, and Hainan) will increase net GHG emission; (3) if straw return is promoted as a feasible mitigation measure in the remaining provinces, the total net mitigation potential before soil organic carbon (SOC) saturation will be 71.89 Tg CO2 equivalent (eqv)/yr, which is equivalent to 1.733% of the annual carbon emission from fossil fuel use in China in 2003; (4) after SOC saturation, only 13 of 21 provinces retain a relatively small but permanent net mitigation potential, while in the others the net GHG mitigation potential will gradually diminish; and (5) the major obstacle to the feasibility or permanence of straw return as a mitigation measure is the increased CH4 emission from rice paddies. The paper also suggests that comparable scenarios in which all the related carbon–nitrogen cycles are taken into account be created to estimate the mitigation potentials of organic wastes in different utilizations and treatments.
Simulated lake phytoplankton composition shifts toward cyanobacteria dominance in a future warmer climate
Authors: Markensten Hampus , Moore Karen , Persson Irina
Published: April 2010

The climate is expected to become warmer and wetter in many temperate regions and is expected to affect the water quality in lakes and reservoirs. In this paper, we investigate the impacts of a regional climate scenario on lake productivity using three models in sequence and quantify the response in biomass of three phytoplankton groups. We used a watershed model (GWLF), a physical lake model (PROBE), and a phytoplankton model (PROTBAS) for simulations of a large (61 km2), shallow (mean depth 3.4 m), wind‐exposed lake basin with a short water retention time (1 month) at the western end of Lake Mälaren, Sweden. The results suggest that a future scenario with increased warming leads to a longer growing season for phytoplankton, slightly increased levels of total biomass, and a distinct shift in phytoplankton groups to favor nitrogen‐fixing cyanobacteria at the expense of diatoms in this lake basin. The changes in the timing of nutrient export from the catchment are the primary cause of cyanobacteria dominance over diatoms, and elevated lake temperatures are responsible for the increase in total phytoplankton biomass.
Vegetation responses to the first 20 years of cattle grazing in an Australian desert
Authors: Fensham R. J. , Fairfax R. J. , Dwyer J. M.
Published: April 2010

Existing theoretical frameworks suggest three predictions relevant to grazing effects in Australian aridlands: grazing has a negative but moderate effect on plant species richness; a separate “state” resulting from degradation caused by extreme grazing will be evident; some plant species will have a strong association with grazing relief refuges that have only ever been subject to light grazing. These predictions were examined in the dune swales of an Australian desert, with data on herbaceous species collected along transects up to 14 km from artificial water points between four and 33 years old. A cumulative grazing index was constructed utilizing both the spatial occupation patterns of cattle and the length of exposure. Despite restricting sampling to a narrow habitat, silt/clay content and soil pH influence floristic patterns independent of grazing. The analysis of quadrat data in relation to grazing revealed almost no patterns in plant cover, species richness (at two different scales), or abundance across plant life‐form groups. Five species had an increasing response, and seven a decreasing response, while the only species restricted to areas of extremely low grazing pressure was sufficiently rare that it could have occurred there by chance. The dominant annual grass, the most common shrub, and a perennial tussock‐forming sedge all decrease with high levels of grazing. Most species exhibit an ephemeral life strategy in response to unreliable rainfall, and this boom and bust strategy effectively doubles as an adaptation to grazing. After 20 years of exposure to managed grazing with domestic stock in Australian dune swales, patterns in species richness have not emerged in response to grazing pressure, the ecosystem has not been transformed to another degradation “state,” and there is no evidence that grazing relief refuges provide havens for species highly sensitive to grazing.
The effects of temporally variable dispersal and landscape structure on invasive species spread
Authors: Andrew Margaret E. , Ustin Susan L.
Published: April 2010

Many invasive species are too widespread to realistically eradicate. For such species, a viable management strategy is to slow the rate of spread. However, to be effective, this will require detailed spread data and an understanding of the influence of environmental conditions and landscape structure on invasion rates. We used a time series of remotely sensed distribution maps and a spatial simulation model to study spread of the invasive Lepidium latifolium (perennial pepperweed) in California's Sacramento‐San Joaquin River Delta. L. latifolium is a noxious weed and exhibited rapid, explosive spread. Annual infested area and empirical dispersal kernels were derived from the remotely sensed distributions in order to assess the influence of weather conditions on spread and to parameterize the simulation model. Spread rates and dispersal distances were highest for nascent infestations and in years with wet springs. Simulations revealed that spread rates were more strongly influenced by the length of long‐distance dispersal than by temporal variation in its likelihood. It is thus important to capture long‐distance dispersal and the conditions that facilitate spread when collecting data to parameterize spread models. Additionally, management actions performed in high‐spread years, targeting long‐distance recruits, can effectively contain infestations. Corridors were relatively unimportant to spread rates; their effectiveness at enhancing rate of spread was limited by the species' dispersal ability and the time needed to travel through the corridor. In contrast, habitat abundance and shape surrounding the introduction site strongly influenced invasion dynamics. Satellite patches invading large areas of invasible habitat present especially high risk.
Scaling plant nitrogen use and uptake efficiencies in response to nutrient addition in peatlands
Authors: Iversen Colleen M. , Bridgham Scott D. , Kellogg Laurie E.
Published: April 2010

Nitrogen (N) is the primary growth‐limiting nutrient in many terrestrial ecosystems, and therefore plant production per unit N taken up (i.e., N use efficiency, NUE) is a fundamentally important component of ecosystem function. Nitrogen use efficiency comprises two components: N productivity (AN, plant production per peak biomass N content) and the mean residence time of N in plant biomass (MRTN). We utilized a five‐year fertilization experiment to examine the manner in which increases in N and phosphorus (P) availability affected plant NUE at multiple biological scales (i.e., from leaf to community level). We fertilized a natural gradient of nutrient‐limited peatland ecosystems in the Upper Peninsula of Michigan, USA, with 6 g N·m−2·yr−1, 2 g P·m−2·yr−1, or a combination of N and P. Our objectives were to determine how changes in carbon and N allocation within a plant to leaf and woody tissue and changes in species composition within a community, both above‐ and belowground, would affect (1) NUE; (2) the adaptive trade‐off between the components of NUE; (3) the efficiency with which plants acquired N from the soil (N uptake efficiency); and (4) plant community production per unit soil N availability (N response efficiency, NRE). As expected, N and P addition generally increased aboveground production and N uptake. In particular, P availability strongly affected the way in which plants took up and used N. Nitrogen use efficiency response to nutrient addition was not straightforward. Nitrogen use efficiency differed between leaf and woody tissue, among species, and across the ombrotrophic–minerotrophic gradient because plants and communities were adapted to maximize eitherANor MRTN, but not both concurrently. Increased N availability strongly decreased plant and community N uptake efficiency, while increased P availability increased N uptake efficiency, particularly in a nitrogen‐fixing shrub. Nitrogen uptake efficiency was more important in controlling overall plant community response to soil N availability than was NUE, and above‐ and belowground community N uptake efficiencies responded to nutrient addition in a similar manner. Our results demonstrate that plants respond to nutrient availability at multiple biological scales, and we suggest that N uptake efficiency may be a more representative measurement of plant responses to nutrient availability gradients than plant NUE.
Use of N immobilization to tighten the N cycle in conventional agroecosystems
Authors: McSwiney Claire P. , Snapp Sieglinde S. , Gentry Lowell E.
Published: April 2010

Soils in conventional agroecosystems are purposely held in a nitrogen (N)‐saturated state to maximize crop yields. Planting winter annual cover crops when fields are usually fallow has been proposed to ameliorate N losses from soils. In this study we introduced winter annual cover crops into an N rate study with plots fertilized at 0, 34, 67, 101, 134, 168, and 202 kg N/ha in maize (Zea mays L.) to determine how winter annual cover crops affect yields, N2O and NO3− fluxes, and N pools. At the six‐leaf stage and during flowering, incorporation of cover crop into soil resulted in a 30% reduction in maize biomass. Three weeks after fertilization, KCl‐extractable soil mineral N was 75–87% lower in cover‐cropped soils than in no‐cover soils, indicating that N had been immobilized in the cover‐cropped soils. At physiological maturity, there was no difference between cover and no‐cover treatments in crop yield, which was maximized at 9 Mg/ha in 2006 and 7 Mg/ha in 2007. Where N rates exceed crop requirements, cover crop incorporation may reduce N exports as NO3− and N2O. Tighter N cycling in conventional agroecosystems could be fostered by matching N rates to the amount of N removed with grain and using N immobilization to retain N and support yields. If N immobilization is viewed as a means for efficient fertilizer N use rather than a process that decreases crop productivity, growers might be more willing to adopt cover‐cropping practices.