bluuebunny/crossref_metadata_2025 huggingface dataset:
Flora of the Venezuelan Guayana. Volume 1. Introduction. Volume Editors: Paul E. Berry, Bruce K. Hoist & Kay Yatskievych. General Editors: Julian A. Steyermark, Paul E. Berry & Bruce K. Hoist.
Authors: Bridgewater S.
Published: April 2010

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Terrestrial Orchids: From Seed to Mycotrophic Plant. Hanne N. Rasmussen.
Authors: Bateman R. M.
Published: April 2010

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Illustrations on the Flora of the Palni Hills, South India. K. M. Matthew.
Authors: Pendry C.
Published: April 2010

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Fungi on Rhododendron: A World Reference. D. F. Farr, H. B. Esteban & M. E.
Authors: Helfer S.
Published: April 2010

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Dictionary of Plant Names in Latin, German, English and French. Hristo Nikolov. J. Kramer in der Gebriider Borntraeger Verlagsbuchhandlung.
Authors: Hedge I.
Published: April 2010

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Fungi and Environmental Change. Edited by J. C. Frankland, N. Magan & G. M. Gadd.
Authors: Rutter G.
Published: April 2010

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A Guide to Species Irises: Their Identification and Cultivation. Edited by The Species Group of the British Iris Society.
Authors: Matthews V.
Published: April 2010

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EJB volume 55 issue 1 Cover and Front matter
Authors: Editor Journal
Published: April 2010

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A cladistic analysis of ndhF sequences from representative species of Saintpaulia and Streptocarpus subgenera Streptocarpus and Streptocarpella (Gesneriaceae)
Authors: Smith J. F. , Kresge M. E. , Möller M. , Cronk Q. C. B.
Published: April 2010

Two African genera of the Gesneriaceae, Saintpaulia and Streptocarpus, are similar in many respects. Both genera have blue to purple flowers, pollen of similar shape and exine sculpting, embryos with one-celled, uninucleate chalazal haustoria, shared vegetative structures among some species, and are among the few genera in the Gesneriaceae which include species with chromosome counts of n = 15. The similarity of these features has indicated that the two genera are likely to be closely related.
The carpology and taxonomic relationships of Davidsonia (Davidsoniaceae)
Authors: Doweld A. B.
Published: April 2010

The fruit of Davidsonia pruriens F. v. Muell. drying and splitting at maturity into two indehiscent mericarps is re-defined as a schizocarpic didrupe. The sclerified mesendocarpic construction of the whole pericarp supports its classification as a drupe. The peculiar fimbriate surface of the mericarp is caused by the destruction of parenchymatous exocarpic and mesocarpic tissues exposing radially elongated mesendocarpic osteosclereids. The seed coat is described as diffusive exotegmic with expanding pachychalaza substituting the two integuments in the chalazal half of the seed. The diffusive exotegmy of the spermoderm supports a close relationship with Cunoniaceae, but refutes any relationships with Saxifragales or with Staphyleaceae or any Hamamelidae. The seed-coat structure indicates advancement and specialization of Davidsonia among Cunoniales; its origin could trace back possibly to Rosales, but never to hamamelidalean stock.
The relationships of Whitesloanea crassa
Authors: Bruyns P. V.
Published: April 2010

It is shown that the monotypic genus Whitesloanea (Asclepiadaceae, Stapelieae) is closely allied to Duvalia and Huernia but nevertheless should remain separate from them. The basionym, Caralluma crassa N.E. Br., is lectotypified.
New species of Juncus (Juncaceae) from the Sino-Himalaya
Authors: Noltie H. J.
Published: April 2010

Three new species of Juncus (Juncaceae) are described: Juncus funbristyloides from China (Yunnan), Juncus deosaicus from Pakistan and Juncus tobdenii from India (Sikkim).
Guide to the Vascular Plants of Central French Guiana. Part 1. Pteridophytes, Gymnosperms, and Monocotyledons. Scott A. Mori, Georges Cremers, Carol Gracie, Jean-Jacques de Granville, Michel Hoff & John D. Mitchell.
Authors: Bridgewater S.
Published: April 2010

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Orchids of Samoa. Phillip J. Cribb & W. Arthur Whistler.
Authors: Bateman R. M.
Published: April 2010

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On descent theory and main conjectures in non-commutative Iwasawa theory
Authors: Burns David , Venjakob Otmar
Published: April 2010

We develop an explicit descent theory in the context of Whitehead groups of non-commutative Iwasawa algebras. We apply this theory to describe the precise connection between main conjectures of non-commutative Iwasawa theory (in the spirit of Coates, Fukaya, Kato, Sujatha and Venjakob) and the equivariant Tamagawa number conjecture. The latter result is both a converse to a theorem of Fukaya and Kato and also provides an important means of deriving explicit consequences of the main conjecture and proving special cases of the equivariant Tamagawa number conjecture.
Une dualité entre fonctions booléennes
Authors: Poizat Bruno
Published: April 2010

Si k est un corps fini, toute fonction f(x1, … , xm) de {0, 1}m dans k s'écrit de manière unique comme un polynôme, à coefficients dans k, de degré un ou zéro en chacune de ses variables ; on peut donc lui associer une fonction f*(x1, … , xm), sa duale inverse, qui exprime les coefficients de son polynôme canonique. Nous considérons l'improbable hypothèse que la classe P(k), formée des suites de fonctions calculables en un nombre d'opérations (additions et multiplications) de croissance polynomialement bornée, soit close par dualité ; nous montrons qu'elle équivaut à une hypothèse bien connue en Théorie de la Complexité sous le nom de P = #pP, où p est la caractéristique de k.

Dans une première section, nous exposons ce résultat lorsque k = ℤ/2ℤ, c'est-à-dire dans le cadre des calculs booléens classiques ; sa démonstration évite l'emploi d'un polynôme universel comme le hamiltonien : ses ingrédients sont d'une part la réduction parcimonieuse des circuits aux termes, et d'autre part la constatation que les expressions arithmétiques ont une duale très facile à calculer.

Dans la deuxième section, nous traitons le cas général, en introduisant une classe SP(k) obtenue par sommation à partir de la classe P(k) ; nous vérifierons dans la quatrième section l'équivalence des hypothèses SP(k) = P(k) et #pP = P. Nous y définissons également une notion de transformation, dont la dualité est un cas particulier. Les transformations forment un groupe isomorphe à GL2(k), avec un sous-groupe B(k) de transformations que nous qualifions de bénignes, car elles n'ont que peu d'effet sur la complexité des fonctions ; nous montrons que toutes les transformations non-bénignes ont à peu près la même influence sur la complexité des fonctions, sauf si k = F3 ou k = F5 ; dans ces deux cas exceptionnels, la transformation de Fourier joue un rôle particulier.

Dans la troisième section, nous considérons des fonctions de km dans k ; nous n'y trouvons pas des classes de complexité vraiment nouvelles, mais seulement un groupe de transformations plus riche.

La quatrième section introduit l'égalité #P = P dans le paysage ; quant à la cinquième et dernière, elle examine le lien entre nos résultats et ceux de Guillaume Malod concernant la clôture par fonction-coefficient de diverses classes de complexité pour le calcul des polynômes à la manière de Valiant.

Nous nous sommes efforcés de rédiger cet article de manière à ce qu'il puisse être lu par des personnes non spécialisées en algorithmie.
Self‐consistent ionospheric plasma density modifications by field‐aligned currents: Steady state solutions
Authors: Russell A. J. B. , Wright A. N. , Hood A. W.
Published: April 2010

The magnetosphere and ionosphere are coupled by field‐aligned currents that remove or deposit E‐region electrons. Changes in electron number density modify ionospheric reflectivity, hence altering the magnetospheric current. Thus, self‐consistent solutions are nontrivial. In this paper, we present 1‐D steady states that self‐consistently model modifications of ionospheric plasma density by field‐aligned currents. These are used to investigate the width broadening and minimum plasma density of E‐region plasma density cavities and the origin of small‐scale features observed in downward current channels. A plasma density cavity forms and broadens if the maximum initial current density j∥0 exceeds jc = αne2he/(1 + 1/β), where α is the recombination coefficient, ne is the equilibrium E‐region number density in the absence of currents, h is the E‐region thickness, and β = is the initial ratio of Pedersen to magnetospheric Alfvén conductivities. If a plasma density cavity forms, its final width increases monotonically with �� = 2B0/μ0VAαne2he, where B0 is the background magnetic field strength and VA is the magnetospheric Alfvén speed. The minimum E‐region number density, and the finest length scale present in the steady state, both scale as 1/β. For typical ionospheric parameters and j∥0 = 5 μAm−2, the fine scale is comparable to or less than 6λe for β ≳ 2, where λe is the electron inertial length. This suggests that electron inertial effects may become significant and introduce small‐scale features, following the production of a single fine scale by depletion and broadening.
Plasmaspheric EUV images seen from lunar orbit: Initial results of the extreme ultraviolet telescope on board the Kaguya spacecraft
Authors: Yoshikawa I. , Murakami G. , Ogawa G. , Yoshioka K. , Obana Y. , Taguchi M. , Yamazaki A. , Kameda S. , Nakamura M. , Kikuchi M. , Kagitani M. , Okano S. , Miyake W.
Published: April 2010

The Telescope of Extreme Ultraviolet (TEX) aboard Japan's lunar orbiter Kaguya has succeeded in imaging of the plasmaspheric helium ions by detecting resonantly scattered emission at 30.4 nm. After the initial instrumental check was completed, TEX has been operated routinely, and EUV images from TEX have become available from the perspective of the lunar orbit. The view afforded by the Kaguya orbit encompasses the plasma (He+) distribution in a single exposure, enabling us to examine for the first time the globally averaged properties of the terrestrial plasmasphere from the “side” (meridian) perspective. In this paper we report the inward motion of the nightside plasmapause on 2 May 2008 as seen from this remote meridian view of the Earth. The southward turning of the IMF initiated the inward motion of the plasmapause, and the nightside plasmasphere shrunk at a rate of 0.2 Re/h. Simultaneous solar wind velocity measurements provide a possible explanation for the total radial displacement of the plasmasphere observed in the EUV images.
New estimates of the large‐scale Arctic atmospheric energy budget
Authors: Porter David F. , Cassano John J. , Serreze Mark C. , Kindig David N.
Published: April 2010

New estimates of the current energy budget of the north polar cap (the region north of 70°N) are synthesized by combining data from new atmospheric reanalyses and satellite retrievals. For the period 2000–2005, monthly means from the Clouds and the Earth's Radiant Energy System (CERES) satellite data set are considered to provide the most reliable top‐of‐atmosphere (TOA) radiation budget. The remaining components of the energy budget, comprising of the energy storage, horizontal convergence of energy, and the net surface flux between the atmospheric and subsurface columns, are compiled using data from the Japanese 25 Year Reanalysis Project (JRA) and the National Centers for Environmental Prediction (NCEP) /National Center for Atmospheric Research (NCAR) Reanalysis (NRA). The annual cycles of energy budget components for the polar cap are fairly consistent between the JRA and NRA, but with some systematic differences. JRA depicts an annual mean surface flux of 14 W m−2 (upward), compared to only 5 W m−2 in NRA. Most of this disparity appears to be due to differences in sea ice and albedo. Horizontal atmospheric energy flux divergence calculated using mass‐corrected flux values contains artifacts leading to unphysical results. We argue that backing out the energy flux convergence as a residual from the net surface heat flux and time change in energy storage from each reanalysis, and the TOA radiation budget from CERES, provides for more physically realistic results in the Arctic. Monthly mean anomalies of budget terms, used to examine conditions leading to the extreme seasonal sea ice extent minimum of September 2005, point to the importance of albedo feedback.
Seasonal H2O and CO2 ice cycles at the Mars Phoenix landing site: 1. Prelanding CRISM and HiRISE observations
Authors: Cull Selby , Arvidson Raymond E. , Mellon Michael , Wiseman Sandra , Clark Roger , Titus Timothy , Morris Richard V. , McGuire Patrick
Published: April 2010

The condensation, evolution, and sublimation of seasonal water and carbon dioxide ices were characterized at the Mars Phoenix landing site from Martian northern midsummer to midspring (Ls ∼ 142° – Ls ∼ 60°) for the year prior to the Phoenix landing on 25 May 2008. Ice relative abundances and grain sizes were estimated using data from the Compact Reconnaissance Imaging Spectrometer for Mars and High Resolution Imaging Science Experiment aboard Mars Reconnaissance Orbiter and a nonlinear mixing model. Water ice first appeared at the Phoenix landing site during the afternoon in late summer (Ls ∼ 167°) as an optically thin layer on top of soil. CO2 ice appeared after the fall equinox. By late winter (Ls ∼ 344°), the site was covered by relatively pure CO2 ice (∼30 cm thick), with a small amount of ∼100 μm diameter water ice and soil. As spring progressed, CO2 ice grain sizes gradually decreased, a change interpreted to result from granulation during sublimation losses. The combined effect of CO2 sublimation and decreasing H2O ice grain sizes allowed H2O ice to dominate spectra during the spring and significantly brightened the surface. CO2 ice disappeared by early spring (Ls ∼ 34°) and H2O ice by midspring (Ls ∼ 59°). Spring defrosting was not uniform and occurred more rapidly over the centers of polygons and geomorphic units with relatively higher thermal inertia values.
Diversity of rock varnish bacterial communities from Black Canyon, New Mexico
Authors: Northup Diana E. , Snider Jessica R. , Spilde Michael N. , Porter Megan L. , van de Kamp Jodie L. , Boston Penelope J. , Nyberg April M. , Bargar John R.
Published: April 2010

Scientists vigorously debate the degree to which rock varnish is formed through the actions of microorganisms. To investigate this enigma, we utilized a three‐pronged approach that combined (1) culture‐independent molecular methods to characterize bacterial communities associated with varnish that coats the rhyolitic volcanic rocks of Black Canyon, New Mexico, and rocks with no visible varnish; (2) culturing of varnish in media supplemented with reduced forms of manganese and/or iron and no or low amounts of carbon to isolate bacteria capable of precipitating iron and/or manganese oxides; and (3) scanning electron microscopy (SEM) of varnish and nearby rock that lacks macroscopically visible varnish. Our culture‐independent studies revealed significant differences between varnish and nonvarnish communities. Chloroflexi and Ktedobacteria dominated one varnish site, while the other varnish site was dominated by Cyanobacteria. The nonvarnish sites were dominated by Actinobacteria and, to a lesser extent, Cyanobacteria and were the only samples to contain Deinococcus‐Thermus sequences. Approximately 65% of varnish cultures produced visible manganese precipitates. Most culture isolates were not closely related to known manganese oxidizers, with the exception of Bacillus spp. SEM revealed microbial morphologies and two types of varnish morphologies: (1) relatively smooth layers and (2) patches of botryoidal pinnacles, which were often associated with increased manganese concentrations. “Bare” rock showed evidence of incipient varnish. These results have important implications for the detection of life on extraterrestrial planets such as Mars, where putative varnish coatings have been observed, and represent some of the first culture‐independent characterizations of varnish communities.
Indices for calibration data selection of the rainfall‐runoff model
Authors: Liu Jia , Han Dawei
Published: April 2010

The identification of rainfall‐runoff models requires selection of appropriate data for model calibration. Traditionally, hydrologists use rules of thumb to select a certain period of hydrological data to calibrate the models (i.e., 6 year data). There are no numerical indices to help hydrologists to quantitatively select the calibration data. There are two questions: how long should the calibration data be (e.g., 6 months), and from which period should the data be selected (e.g., which 6 month data should be selected)? In this study, some indices for the selection of calibration data with adequate lengths and appropriate durations are proposed by examining the spectral properties of data sequences before the calibration work. With the validation data determined beforehand, we assume that the more similarity the calibration data set bears to the validation set, the better should the performance of the rainfall‐runoff model be after calibration. Three approaches are applied to reveal the similarity between the validation and calibration data sets: flow‐duration curve, Fourier transform, and wavelet analysis. Data sets used for calibration are generated by designing three scenario groups with fixed lengths of 6, 12, and 24 months, respectively, from 8 year continuous observations in the Brue catchment of the United Kingdom. Scenarios in each group have different starting times and thus various durations with specific hydrological characteristics. With a predetermined 18 month validation set and the rainfall‐runoff model chosen to be the probability distributed model, useful indices are produced for certain scenario groups by all three approaches. The information cost function, an entropy‐like function based on the decomposition results of the discrete wavelet transform, is found to be the most effective index for the calibration data selection. The study demonstrates that the information content of the calibration data is more important than the data length; thus 6 month data may provide more useful information than longer data series. This is important for hydrological modelers since shorter and more useful data help hydrologists to build models more efficiently and effectively. The idea presented in this paper has also shown potential in enhancing the efficiency of calibration data utilization, especially for data‐limited catchments.
Digital Atlas of Mexico Provides Accessible Climate Information
Authors: Zavala‐Hidalgo Jorge , Fern´ndez‐Eguiarte Agustin , Romero‐Centeno Rosario , Zavala‐Romero Olmo
Published: April 2010

Modern geomatic technologies—and particularly geoscientific, digital, and online multimedia cartography—represent one response to the growing demand for climatic information by the scientific community and general users.

The Digital Climatic Atlas of Mexico (DCAM) fills the need to have readily accessible climate information about Mexico, Central America, and adjacent areas in preconfigured or user‐configured georeferenced maps. The atlas provides information about the continental and oceanic climate, bioclimatic variables, and socioeconomic indicators (Figure 1).
Comment on “Examining the Scientific Consensus on Climate Change”
Authors: Rawer Karl
Published: April 2010

In the 20 January 2009 issue of Eos (90(3), 22–23), P. T. Doran and M. K. Zimmerman gave some interesting data about scientists' responses to the question of whether they think human activity is a significant contributing factor to changing global temperatures. The statements given in the article are in fact “scientific” in that they are cautious. In my opinion, they miss the point.

While scientists are yet discussing the importance and potential magnitude of human influence, the public expects an answer to this simple question: “Would the warming be stopped or even reversed if the requested rigorous actions were taken?” Scientists have carefully avoided answering that blunt question, but most of the public and the politicians, at least in my country, are convinced that an overwhelming majority of scientists is answering “yes.”
Site Selected for Colorado Plateau Coring: Colorado Plateau Coring Project Workshop, Phase 2: 100 Million Years of Climatic, Tectonic, and Biotic Evolution From Continental Coring; Albuquerque, New Mexico, 8–11 May 2009
Authors: Geissman John W. , Olsen Paul E. , Kent Dennis V.
Published: April 2010

A workshop was convened in New Mexico to plan for the Colorado Plateau Coring Project (CPCP) and identify the target site for initial coring. The giant continental and near‐shore to shallow marine epicontinental basins of the American Southwest are particularly well exposed on the Colorado Plateau and its environs and contain a rich record of early Mesozoic (∼251–145 million years ago) strata. This time period was punctuated by two major mass extinctions and is notable for the evolutionary appearance of the modern biota and its apparent dramatic climate changes.

Classic studies of these basins, their strata, and their fossils have made this sequence instrumental in framing the context for the early Mesozoic world. Ambiguities in temporal resolution, uncertainties in global correlations with other early Mesozoic strata, and major doubts about latitudinal position still hamper testing of competing climatic, biotic, and tectonic models for the evolution of western Pangea.
Future Scientific Drilling of Oceanic Crust
Authors: Hayman Nicholas W. , Bach Wolfgang , Blackman Donna , Christeson Gail L. , Edwards Katrina , Haymon Rachel , Ildefonso Benoit , Schulte Mitch , Tagle Damon , White Scott
Published: April 2010

Processes that occur within and across the oceanic crust—in particular along mid‐ocean ridges and oceanic spreading centers—play a huge role in the dynamics of the Earth. The largest fluxes of heat and material between the Earth's mantle, crust, and seawater occur via magmatic, tectonic, and hydrothermal processes along oceanic spreading centers and their vast flanks. Roughly two thirds of the Earth's surface is accreted through magmatic and tectonic processes along mid‐ocean ridges, and subduction of this ocean crust in turn influences mantle compositions. Exchange of elements between ocean crust and seawater strongly influences seawater compositions and leaves a geologic record of fluid‐rock reactions in altered ocean crust. Some of these reactions contribute energy to microbial activity of a largely unexplored biosphere. The dynamics of ridge and ocean crustal processes therefore have enormous implications for thermal, chemical, and biological exchanges between the solid Earth and the hydrosphere.
What Is the Atmosphere's Effect on Earth's Surface Temperature?
Authors: Zeng Xubin
Published: April 2010

It is frequently stated in textbooks and scholarly articles that the surface temperature of Earth is 33°C warmer than it would be without the atmosphere and that this difference is due to the greenhouse effect. This Forum shows that the atmosphere effect leads to warming of only 20°C. This new conclusion requires a revision to all of the relevant literature in K‐12, undergraduate, and graduate education material and to science papers and reports.
Brenguier Receives 2009 Keiiti Aki Young Scientist Award
Authors: Brenguier Florent , Shapiro Nikolai
Published: April 2010

Florent Brenguier received the 2009 Keiiti Aki Young Scientist Award at the 2009 AGU Fall Meeting, held 14–18 December in San Francisco, Calif. The award recognizes the scientific accomplishments of a young scientist who makes outstanding contributions to the advancement of seismology.
New AGU Journal Editors Appointed
Authors: Major Barbara
Published: April 2010

Geochemistry, Geophysics, Geosystems welcomes Joel A. Baker (Victoria University, Wellington, New Zealand), Louis A. Derry (Cornell University, Ithaca, N.Y.), and James A. Tyburczy (Arizona State University, Tempe). They are filling the vacancies of retiring editors Vincent Salters and John Tarduno and are joining continuing editor Thorsten Becker.
Valery Troitskaya (1917–2010)
Authors: Heirtzler James , Kivelson Margaret , Nazarova Katherine
Published: April 2010

Valery Troitskaya passed away in Melbourne, Victoria, Australia, on 22 January 2010 at age 92. She was a well‐known Russian scientist, respected and loved all over the world. She understood early that much could be learned about space plasmas by characterizing their natural oscillations, and she devoted her scientific career to exploiting that perception. Her devotion to friends and colleagues was legendary, and there are many who owe their success in their scientifi c careers to her effective support. Her life experiences were unique and an inspiration to all who knew her.
Establishing Priorities for Interdisciplinary Arctic Ocean Science: Arctic in Rapid Transition (ART) Initiation Workshop; Fairbanks, Alaska, 7–9 November 2009
Authors: Frey Karen E. , Mathis Jeremy T. , Wegner Carolyn
Published: April 2010

The Arctic is undergoing rapid environmental and economic transformations. Recent climate warming, which is simplifying access to oil and gas resources, enabling trans‐ Arctic shipping, and shifting the distribution of harvestable resources, has brought the Arctic Ocean to the top of national and international political agendas. Scientific knowledge of the present status of the Arctic Ocean and a process‐based understanding of the mechanisms of change are required to make useful predictions of future conditions throughout the Arctic region.

A step toward improving scientists' capacity to predict future Arctic change was undertaken with the Second International Conference on Arctic Research Planning (ICARP II) meeting in 2005 (http://web.arcticportal.org/iasc/icarp). As the ICARP II process came to a close, the Arctic in Rapid Transition (ART) initiative developed out of an effort to synthesize the several ICARP II science plans specific to the Arctic marine environment.
Guides for Authors Translated into Multiple Languages
Authors: Cook William J.
Published: April 2010

The guides for authors for AGU journals and Eos have been translated into four languages. The aim is for AGU's publication guidelines to be more accessible to those scientists for whom English is not their first language.

Translations of the guides for authors are now available in Spanish, French, Chinese, and Japanese. While manuscripts must still be submitted (and published) in English, AGU hopes that having the author guides translated into these languages will encourage authors who might not otherwise submit manuscripts to do so.
Bordoni Receives 2009 James R. Holton Junior Scientist Award
Authors: Alexander M. Joan , Bordoni Simona
Published: April 2010

Simona Bordoni received the 2009 James R. Holton Junior Scientist Award at the 2009 AGU Fall Meeting, held 14–18 December in San Francisco, Calif. The award recognizes outstanding research contributions by a junior atmospheric scientist within 3 years of his or her Ph.D.
AGU Adopts Position Statement on Geoengineering, a Hot Topic in Congress and Elsewhere
Authors: Chell Kaitlin
Published: April 2010

The AGU Council's adoption last December of the American Meteorological Society's position statement, “Geoengineering the Climate System,” is timely. Within the past few months, geoengineering has surfaced as a hot‐button field of study that may hold potential solutions to mitigating global climate change. Congress currently is debating the subject of geoengineering as well as increasing the funding for geoengineering research. The first‐ever series of geoengineering hearings on Capitol Hill recently have been held by the U.S. House of Representatives Committee on Science and Technology.
Demands of Expanding Populations and Development Planning
Authors: Lim Bo
Published: April 2010

This book is a practical resource for development planners, demographers, and organizations involved with development projects related to improving the well‐being and welfare of expanding human populations. Demands of Expanding Populations and Development Planning essentially is a treatment on sustainability and includes a heavy emphasis on major issues of environmental pollution over the last 3 decades. The book's coverage of ecosystems, atmospheric chemistry, water availability and quality, and soils is comprehensive.

The author's extensive teaching experience makes this somewhat of an authoritative book on air quality and emissions from natural and anthropogenic sources, volatile heavy metals, carbon monoxide, radon, and nuclear waste. Most of the book focuses on the atmospheric chemistry of air pollution, whether the pollution source is from energy, industrial production, and manufacturing processes or from the treatment of waste products from such processes.
Development of a rapid, high‐efficiency, scalable refold for neurotrophin‐4
Authors: Buckley John J. , Hoeltzli Sydney D. , Johnson Gary V.
Published: April 2010

A scalable refold for human neurotrophin‐4 was developed as part of a manufacturing process required for the production of supplies for preclinical and clinical studies. The process redox system, chaotrope, solubilization additives, pH, temperature and protein concentration were optimized. The limited availability of suitable material for experimentation during concurrent downstream process development led to the approach described in the present paper: a combination of OFAT (one factor at a time) and multivariate DOE (design of experiments) to identify appropriate conditions. The optimized refold conditions included the use of sulfonated protein, raw materials utilized in other process operations and an inexpensive redox system. The conditions were found to be robust and were demonstrated from the millilitre scale to the 300 litre pilot scale. A process control procedure that utilized an RPC (reversed‐phase chromatography) quantitative assay to monitor the percentage conversion into oxidized protein was developed. Refold conversions of 80–90% were obtained under ambient temperature and atmospheric conditions, with reaction times of approx. 18 h.
Optimization of the BoNT/A‐Hc expression in recombinant Escherichia coli using the Taguchi statistical method
Authors: Yari Kheirollah , Fatemi Seyed Safa‐ali , Tavallaei Mahmoud
Published: April 2010

The use of the recombinant BoNT/A‐Hc (carboxylic domain of the Clostridium botulinum neurotoxin heavy chain) has been proposed as a vaccine candidate for botulism. This fragment contains the principle protective antigenic determinant. In the present study, in order to maximize recombinant protein expression, after verification of recombinant BoNT/A‐Hc by Western blotting, modified M9 medium was selected as a simple medium, and the operational and medium‐composition variables together with their interactions were optimized by using the Taguchi statistical method. ANOVA for the obtained data indicated that 3.5 g, 15 g, 30 g, 15 g, 4 g, 0.7 mM, 1.5 ml per litre of medium, 30 °C and 15 h represented optimum values of (NH4)2SO4, glucose, K2HPO4, KH2PO4, MgSO4·7H2O, isopropyl β‐D‐thiogalactoside concentration, trace‐elements solution, temperature and post‐induction time respectively. Consequently, under these optimum conditions, 52.1 mg/l of soluble BoNT/A‐Hc was obtained in shake flask culture.
Biosynthesis and recovery of selenium nanoparticles and the effects on matrix metalloproteinase‐2 expression
Authors: Shakibaie Mojtaba , Khorramizadeh Mohammad Reza , Faramarzi Mohammad Ali , Sabzevari Omid , Shahverdi Ahmad Reza
Published: April 2010

Today, green synthesis of nanoparticles is attracting increasing attention. In the present study, the Bacillus sp. MSh‐1 was isolated from the Caspian Sea (located in the northern part of Iran) and identified by various identification tests and 16S ribosomal DNA analysis. The reduction time course study of selenium ion (Se4+) reduction by using this test strain was performed in a liquid culture broth. Then, the intracellular NPs (nanoparticles) were released by the liquid nitrogen disruption method and thoroughly purified using an n‐octyl alcohol water extraction system. Characterization of the separated NPs on features such as particle shape, size and purity was carried out with different devices. The energy dispersive X‐ray and X‐ray diffraction patterns showed that the purified NPs consisted of only selenium and are amorphous respectively. In addition, the transmission electron micrograph showed that the separated NPs were spherical and 80–220 nm in size. Furthermore, the cytotoxicity effect of these extracted biogenic selenium (Se) NPs on the fibrosarcoma cell line (HT‐1080) proliferation and the inhibitory effect of the Se NPs on MMP‐2 (matrix metalloproteinase‐2) expression were studied using the MTT [3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide] assay and gelatin zymography. Biogenic Se NPs showed a moderately inhibitory effect on MMP‐2 expression.
Taking the plunge: integrating structural, enzymatic and computational insights into a unified model for membrane-immersed rhomboid proteolysis
Authors: Urban Sinisa
Published: April 2010

Rhomboid proteases are a fascinating class of enzymes that combine a serine protease active site within the core of an integral membrane protein. Despite having key roles in animal cell signalling and microbial pathogenesis, the membrane-immersed nature of these enzymes had long imposed obstacles to elucidating their biochemical mechanisms. But recent multidisciplinary approaches, including eight crystal structures, four computer simulations and nearly 100 engineered mutants interrogated in vivo and in vitro, are coalescing into an integrated model for one rhomboid orthologue in particular, bacterial GlpG. The protein creates a central hydrated microenvironment immersed below the membrane surface to support hydrolysis by its serine protease-like catalytic apparatus. Four conserved architectural elements in particular act as ‘keystones’ to stabilize this structure, and the lateral membrane-embedded L1 loop functions as a ‘flotation device’ to position the protease tilted in the membrane. Complex interplay between lateral substrate gating by rhomboid, substrate unwinding and local membrane thinning leads to intramembrane proteolysis of selected target proteins. Although far from complete, studies with GlpG currently offer the best prospect for achieving a thorough and sophisticated understanding of a simplified intramembrane protease.
The emerging importance of group II PAKs
Authors: Wells Claire M. , Jones Gareth E.
Published: April 2010

The Rho-family GTPases Rho Rac and Cdc42 regulate many intracellular processes through their interaction with downstream effector proteins. The PAKs (p21-activated kinases) are a family of effector proteins for Rac and Cdc42. PAKs are important regulators of actin cytoskeletal dynamics, neurite outgrowth, cell survival, hormone signalling and gene transcription. There are six mammalian PAKs that can be divided into two groups: group I PAKs (PAK1–3) and group II PAKs (PAK4–6). Although the two PAK groups are architecturally similar, there are differences in their mode of regulation, suggesting that their cellular functions are likely to be different. Whereas much is known about group I PAKs, less is known about the more recently discovered PAK4, PAK5 and PAK6. This review will focus on the latest structural and functional results relating to the group II PAKs and discuss the emerging importance of group II PAKs in disease progression.
Pyruvate dehydrogenase kinase 1 controls mitochondrial metabolism and insulin secretion in INS-1 832/13 clonal β-cells
Authors: Krus Ulrika , Kotova Olga , Spégel Peter , Hallgard Elna , Sharoyko Vladimir V. , Vedin Anna , Moritz Thomas , Sugden Mary C. , Koeck Thomas , Mulder Hindrik
Published: April 2010

Tight coupling between cytosolic and mitochondrial metabolism is key for GSIS (glucose-stimulated insulin secretion). In the present study we examined the regulatory contribution of PDH (pyruvate dehydrogenase) kinase 1, a negative regulator of PDH, to metabolic coupling in 832/13 clonal β-cells. Knockdown of PDH kinase 1 with siRNA (small interfering RNA) reduced its mRNA (>80%) and protein level (>40%) after 72 h. PDH activity, glucose-stimulated cellular oxygen consumption and pyruvate-stimulated mitochondrial oxygen consumption increased 1.7- (P<0.05), 1.6- (P<0.05) and 1.6-fold (P<0.05) respectively. Gas chromatography/MS revealed an altered metabolite profile upon silencing of PDH kinase 1, determined by increased levels of the tricarboxylic acid cycle intermediates malate, fumarate and α-ketoglutarate. These metabolic alterations were associated with exaggerated GSIS (5-fold compared with 3.1-fold in control cells; P<0.01). Insulin secretion, provoked by leucine and dimethylsuccinate, which feed into the tricarboxylic acid cycle bypassing PDH, was unaffected. The oxygen consumption and metabolic data strongly suggest that knockdown of PDH kinase 1 in β-cells permits increased metabolic flux of glucose-derived carbons into the tricarboxylic acid cycle via PDH. Enhanced insulin secretion is probably caused by increased generation of tricarboxylic acid cycle-derived reducing equivalents for mitochondrial electron transport to generate ATP and/or stimulatory metabolic intermediates. On the basis of these findings, we suggest that PDH kinase 1 is an important regulator of PDH in clonal β-cells and that PDH kinase 1 and PDH are important for efficient metabolic coupling. Maintaining low PDH kinase 1 expression/activity, keeping PDH in a dephosphorylated and active state, may be important for β-cells to achieve the metabolic flux rates necessary for maximal GSIS.
Temporal regulation of Cat-1 (cationic amino acid transporter-1) gene transcription during endoplasmic reticulum stress
Authors: Huang Charlie C. , Li Yi , Lopez Alex B. , Chiang Cheng-Ming , Kaufman Randal J. , Snider Martin D. , Hatzoglou Maria
Published: April 2010

Expression of the Cat-1 gene (cationic amino acid transporter-1) is induced in proliferating cells and in response to a variety of stress conditions. The expression of the gene is mediated via a TATA-less promoter. In the present study we show that an Sp1 (specificity protein 1)-binding site within a GC-rich region of the Cat-1 gene controls its basal expression and is important for induction of the gene during the UPR (unfolded protein response). We have shown previously that induction of Cat-1 gene expression during the UPR requires phosphorylation of the translation initiation factor eIF2α (eukaryotic initiation factor 2α) by PERK (protein-kinase-receptor-like endoplasmic reticulum kinase), one of the signalling pathways activated during the UPR. This leads to increased translation of the transcription factor ATF4 (activating transcription factor 4). We also show that a second signalling pathway is required for sustained transcriptional induction of the Cat-1 gene during the UPR, namely activation of IRE1 (inositol-requiring enzyme 1) leading to alternative splicing of the mRNA for the transcription factor XBP1 (X-box-binding protein 1). The resulting XBP1s (spliced XBP1) can bind to an ERSE (endoplasmic-reticulum-stress-response-element), ERSE-II-like, that was identified within the Cat-1 promoter. Surprisingly, eIF2α phosphorylation is required for accumulation of XBP1s. We propose that the signalling via phosphorylated eIF2α is required for maximum induction of Cat-1 transcription during the UPR by inducing the accumulation of both ATF4 and XBP1s.
Influence of MgTiO3 on the magnetic and dielectric properties of Ba3Co2Fe24O41 hexaferrite
Authors: Mu C. H. , Liu Y. L. , Zhang H. W. , Song Y. Q. , Wen Q. Y. , Shen J.
Published: April 2010

MgTiO 3 -doped Ba3Co2Fe24O41 hexaferrites (Co2Z) have been prepared by the solid-state reaction method, and the magnetic and dielectric properties have been investigated. Permeability measurements indicate that MgTiO3 doping significantly improves the frequency characteristics of permeability, i.e., with the increase of MgTiO3 doping content from 0 to 5 wt %, the cutoff frequency increases greatly from 0.33 GHz to >1.8 GHz. Although μ′ decreases from 16.1 to 5.4 in a sample doped with 5 wt % MgTiO3, magnetic loss μ″ is effectively suppressed in frequency above 300 MHz. The permittivity of 5 wt % MgTiO3 doped specimen keeps stable in the value of about 17, while the dielectric loss largely decreases in the frequency rang from 300 MHz to 1.8 GHz. The low magnetic and dielectric loss and the improvement of frequency characteristics are crucial for high-frequency antenna applications of Z-type hexaferrites.
Magnetic flux penetration in polycrystalline SmFeO0.75F0.2As
Authors: Lin Zhi Wei , Li Yong Jian , Zhu Jian Guo , Guo Youguang , Wang Xiao Lin
Published: April 2010

The recently discovered Fe–As superconducting materials which show high potential ability to carry current due to their low anisotropy have attracted a great number of attentions to understand their superconductivity mechanism and explore their applications. This paper presents a method to synthesis SmFeO0.75F0.20As polycrystalline by hot press in detail. The magnetization at different temperatures and applied fields obtained by a superconducting quantum interference device are also discussed. In addition, the local magnetization process is presented by magneto-optical imaging technique at the conditions of zero-field-cooling and field-cooling. It is found that the collective magnetization process of the newly discovered Fe–As superconductors is very similar to that of high-Tc cuprates. For instance, the Fe–As superconductors and high-Tc cuprates have the same magnetization features due to strong pining and intergrain weak link. The global supercurrent is significantly lower than local grain supercurrent due to the weak line between the grains.
Rigorous calculation of the Seebeck coefficient and mobility of thermoelectric materials
Authors: Ramu Ashok T. , Cassels Laura E. , Hackman Nathan H. , Lu Hong , Zide Joshua M. O. , Bowers John E.
Published: April 2010

The Seebeck coefficient of a typical thermoelectric material is calculated without recourse to the relaxation time approximation (RTA). To that end, the Boltzmann transport equation is solved in one spatial and two k-space coordinates by a generalization of the iterative technique first described by Rode. Successive guesses for the chemical potential profile are generated until current continuity and charge-neutrality in the bulk of the device are simultaneously satisfied. Both the mobility and Seebeck coefficient are calculated as functions of the temperature and the agreement to experimentally obtained values is found to be satisfactory. Comparison is made with the less accurate RTA result, which has the sole advantage of giving closed form expressions for the transport coefficients.
Structure, properties, and nature of the pyridine-XY (X, Y=F, Cl, Br) complexes: An ab initio study
Authors: Wang Zhaoxu , Zheng Baishu , Yu Xianyong , Li Xiaofang , Yi Pinggui
Published: April 2010

Structure and properties (energies, electronic, and thermodynamic properties) of complexes pyridine-XY (X, Y=F, Cl, Br) have been investigated at the MP2/aug-cc-pVDZ level. Two types of geometries (π-halogen bonded and σ-halogen bonded) are observed. In contrast with the previous results on similar furan and thiophene complexes, the σ-halogen bonded structures are more stable and the reasons are discussed. Charge transfer is found to be important in the formation of title system and the possible existing complexes under experimental conditions have been forecasted too. A symmetry-adapted perturbation theory energy decomposition analysis reveals that the pyridine-XY complexes are dominantly inductive in nature.
Communications: Investigation of the superatomic character of Al13 via its interaction with sulfur atoms
Authors: Zhang Zeng-Guang , Xu Hong-Guang , Feng Yuan , Zheng Weijun
Published: April 2010

We investigated AlnS− (n=3–15) and AlnS2− (n=7–15) clusters with mass spectrometry and photoelectron spectroscopy. We found that Al13 is relatively robust when it reacts with sulfur atoms, indicating that it has some superatomic character. However, Al13 cannot be simply considered as a superatom when it interacts with sulfur due to the following reasons: Al13’s icosahedral structure has been distorted slightly by sulfur atoms; the vertical detachment energies and adiabatic detachment energies of Al13S− and Al13S2− clusters are not significantly different from those of their neighboring clusters; and the charge distributions in Al13S− and Al13S2− do not necessarily associate with superatomic behavior of Al13.
Generalized valence bond wave functions in quantum Monte Carlo
Authors: Anderson Amos G. , Goddard William A.
Published: April 2010

We present a technique for using quantum Monte Carlo (QMC) to obtain high quality energy differences. We use generalized valence bond (GVB) wave functions, for an intuitive approach to capturing the important sources of static correlation, without needing to optimize the orbitals with QMC. Using our modifications to Walker branching and Jastrows, we can then reliably use diffusion quantum Monte Carlo to add in all the dynamic correlation. This simple approach is easily accurate to within a few tenths of a kcal/mol for a variety of problems, which we demonstrate for the adiabatic singlet-triplet splitting in methylene, the vertical and adiabatic singlet-triplet splitting in ethylene, 2+2 cycloaddition, and Be2 bond breaking.
Novel multisample dielectric resonators for electron paramagnetic resonance spectroscopy
Authors: Golovina Iryna S. , Kolesnik Sergiy P. , Geifman Ilia N. , Belous Anatoliy G.
Published: April 2010

We have developed and tested two types of novel dielectric resonators for simultaneous recording of electron paramagnetic resonance (EPR) spectra from two to four samples. The resonator of the first type contains two holes, and the other resonator contains four holes for introduction of the samples. Also, the resonator structure includes a pair of gradient coils. Dielectric resonators made of materials with high dielectric constant with low losses can be inserted into the standard EPR cavity or waveguide in the maximum microwave magnetic field. Gradient coils are located outside the cavity (or waveguide) so that their axes are parallel to the static magnetic field. Computer simulations were made to obtain microwave characteristics of the resonators such as resonant frequency, sizes, and distribution of the fields. Spacing of the point samples and optimum value of the magnetic-field gradient have been chosen correctly. The designed resonators can be applied in express analysis using EPR technique, for instance.