bluuebunny/crossref_metadata_2025 huggingface dataset:
Kollisionssicherheit von Offshore‐Windenergieanlagen
Authors: Biehl Florian
Published: June 2009

Die Bundesrepublik Deutschland ist als rohstoffarmes Land in besonderer Weise auf die Einfuhr von Energieträgern angewiesen. Dies führt zu einer starken Abhängigkeit von den Liefernationen. Daher werden erneuerbare Energiequellen wie Wind‐, Solar‐ und Wasserkraft seit einigen Jahren stark subventioniert, um einen Teil des Energiebedarfs aus diesen decken zu können. Die Erzeugung von Strom aus Wind hat sich als eine sowohl ökonomisch als auch ökologisch sinnvolle Variante herausgestellt. Durch den massiven Ausbau der Windenergie sind heute fast alle möglichen Standorte an Land besiedelt. Die Entwicklung von immer leistungsfähigeren Windenergieanlagen (WEA) erlaubt es nun, die weitaus höheren Windgeschwindigkeiten auf hoher See zu nutzen.

Im Bereich der deutschen Nord‐ und Ostsee sind einige Offshore‐Windparks geplant, die an Gebiete mit sehr regem Schiffsverkehr grenzen. Nach § 3 SeeAnlV ist nachzuweisen, dass ein Windpark die Sicherheit und Leichtigkeit des Schiffsverkehrs sowie die Meeresumwelt nicht gefährdet.

Collision safety of offshore wind turbines.

Germany, as a country with few natural resources relies on the import of energy sources. This leads to a strong dependence on the supplier nations. Therefore, renewable energy sources like wind, solar, or waterpower are heavily subsidized, to cover a part of the required energy. To generate energy from wind is an economic an ecologic useful procedure. By the massive expansion of the wind energy you will find wind turbines nearly in any part of the country. Due to the development of more powerful wind turbines it is possible to set them up offshore.

In some areas next to high shipping traffic in the German North and Baltic Sea, wind energy farms are in planning. According to Clause 3 SeeAnlV it is to demonstrate, that a wind energy farm will not endanger the security and waftability of the shipping traffic and the marine environment.
Traglast von Verbandsstäben aus Hohlprofilen mit quasi‐zentrischem Knotenblechanschluss
Authors: Unterweger Harald , Ofner Robert
Published: June 2009

m Hoch‐ und Industriebau werden oft Fachwerk‐ bzw. Verbandsstäbe mit Hohlprofilquerschnitten ausgeführt, die an beiden Stabenden eingeschlitzte Knotenbleche aufweisen. Diese schließen mittels einer einfachen Baustellenschweiß‐ bzw. Schraubverbindung an ebene – nicht weiter ausgesteifte – Bleche der weiterführenden Konstruktion an. Dabei wird in der Praxis mitunter ein quasi‐zentrischer Anschluss ausgeführt, indem das eingeschlitzte Knotenblech zur Stabachse eine Exzentrizität im Ausmaß der halben Knotenblechdicke aufweist, so dass die Stabexzentrizität minimiert wird.

Nachfolgend wird das Tragverhalten und die Traglast derartiger Verbandsstäbe unter Zug‐ und Drucknormalkräften anhand numerischer Traglastberechnungen analysiert und mit einfachen Berechnungsmodellen der Ingenieurpraxis, auf Basis des Eurocodes – mit und ohne Erfassung der Exzentrizitäten, verglichen.

Die geometrischen Parameter und Randbedingungen werden derart variiert, dass übliche praktische Fälle abgedeckt sind. Trotz der beschränkten Anzahl an untersuchten Einzelstabausführungen ist durch gezielte Variation der Haupteinflussgrößen eine allgemeine Beurteilung des Tragverhaltens möglich. Darauf aufbauend wird ein verbessertes Ingenieurmodell vorgestellt, das eine zutreffende Bemessung erlaubt.

Load bearing capacity of bracing members with almost centric joints.

In building constructions for bracing members often hollow sections are used with slotted gusset plates at the ends. These plates are attached to unstiffened plates of the adjacent construction. In practice sometimes a nearly centred joint is designed, by arranging the slotted gusset plate with an eccentricity of half the plate thickness to the member axis, so that the member eccentricity is minimised.

In the paper the load carrying behaviour of such members under compression and tension is discussed based on numerical analyses with nonlinear FE models including imperfections. The results are also compared with simplified engineering models, based on the Eurocode.

The geometric parameters and boundary conditions are varied in such a way that practical cases are covered and that the typical load carrying behaviour can be seen. Based on these results an improved engineering model for the design is represented.
Assessing the interest for systems engineering positions and other engineering positions' required capacity for engineering systems thinking (CEST)
Authors: Frank Moti
Published: June 2009

The selection process for systems engineering positions should reliably predict those employees who can succeed and reject those who are likely to fail. In order to be a successful systems engineer, one must have both a will and an interest to be a systems engineer. This paper introduces a tool for assessing engineers' interest regarding systems engineering positions and the results of three studies aimed at examining its reliability and validity. The will and the interest to be a systems engineer mainly means the will and interest to deal with positions that require a capacity for engineering systems thinking (CEST). The interest inventory presented in this paper is a tool for assessing Interest for Systems Engineering Positions and other Engineering Position' Required Capacity for Engineering Systems Thinking (CEST). The findings of the three studies indicate that the tool might prove to be a useful instrument, which could be used by organizations, as well as systems engineering researchers and educators alike. However, the results still await verification and validation by additional studies. © 2009 Wiley Periodicals, Inc. Syst Eng
Investigating the effect of stiffness and strength of each component on overall stiffness and strength of yielding damped braced core (YDBC)
Authors: Sabouri‐Ghomi Saeid , Payandehjoo Barash
Published: June 2009

Yielding damped braced core (YDBC) consists of a central‐framed steel plate (damper) located at the intersection of X bracing members. In severe earthquakes, the damper would yield and will result in spindle hysteresis cycles. YDBC is capable of dissipating large amounts of energy. In the present paper, an investigation is made on how individual components of the system affect the overall strength and stiffness of the system. The results are verified by a sample problem. It is calculated that the stiffness of braces, as well as the central core, play a major role in system overall stiffness. And finally, using properly designed braces, the energy absorption mechanism could be transferred to the central core. Copyright © 2009 John Wiley & Sons, Ltd.
Self‐recognition in the Asian elephant and future directions for cognitive research with elephants in zoological settings
Authors: Plotnik Joshua M. , de Waal Frans B.M. , Moore Donald , Reiss Diana
Published: June 2009

The field of animal cognition has grown steadily for nearly four decades, but the primary focus has centered on easily kept lab animals of varying cognitive capacity, including rodents, birds and primates. Elephants (animals not easily kept in a laboratory) are generally thought of as highly social, cooperative, intelligent animals, yet few studies—with the exception of long‐term behavioral field studies—have been conducted to directly support this assumption. In fact, there has been remarkably little cognitive research conducted on Asian (Elephas maximus) or African (Loxodonta africanaorL. cyclotis) elephants. Here, we discuss the opportunity and rationale for conducting such research on elephants in zoological facilities, and review some of the recent developments in the field of elephant cognition, including our recent study on mirror self‐recognition inE. maximus. Zoo Biol 29:179–191, 2010. © 2009 Wiley‐Liss, Inc.
Partial Splenic Embolization Versus Splenectomy for the Management of Hypersplenism in Cirrhotic Patients
Authors: Amin Mahmoud A. , El Gendy Mohamed M. , Dawoud Ibrahim E. , Shoma Ashraf , Negm Ahmed M. , Amer Talal A.
Published: June 2009

Background

Hypersplenism occurs in patients with chronic liver disease, and splenectomy is the definitive treatment. However, the operation may be hazardous in patients with poor liver function. In recent years, partial splenic embolization (PSE) has been widely used in patients with hypersplenism and cirrhosis. This study was conducted to assess the safety and efficacy of PSE compared to splenectomy in the management of hypersplenism in cirrhotic patients.

Methods

This study comprised 40 patients with hypersplenism secondary to cirrhosis. They were divided into two groups, each including 20 patients. The first group of patients were treated by PSE using polyvinyl alcohol particles to achieve embolization of at least 50% of the distal branches of the splenic artery. Postembolization arteriography and computed tomography were performed to document the extent of devascularization. Patients in the second group were treated by splenectomy with or without devascularization and left gastric ligation according to the presence or absence of esophageal varices.

Results

There was marked improvement in platelet and leukocytic counts in both groups, and the counts remained at appropriate levels during the follow‐up period. All patients in the first group had problems related to postembolization syndrome that abated by the first week. One patient in the first group died from myocardial infarction. No deaths occurred in the second group. Asymptomatic portal vein thrombosis developed in one patient in the first group that was treated with anticoagulation, and another patient developed splenic abscess treated by splenectomy with a good outcome. In the second group, three patients developed portal vein thrombosis, one of them being readmitted 4 months postoperatively with mesenteric vascular occlusion; that patient underwent a resection anastomosis with good outcome.

Conclusions

Partial splenic embolization is an effective therapeutic modality for the treatment of hypersplenism secondary to chronic liver disease. It is a simple, rapid procedure that is easily performed under local anesthesia; and it allows preservation of adequate splenic tissue to safeguard against overwhelming infection.
A comparison of phenotypic plasticity between two species occupying different positions in a successional sequence
Authors: Huang Yingxin , Zhao Xueyong , Zhang Hongxuan , Huang Gang , Luo Yayong , Japhet Wisdom
Published: June 2009

We compared the phenotypic plasticity of two greenhouse‐grown species (Corispermum macrocarpum and Salsola collina) occupying different positions in a successional sequence in Horqin Sandy Land, by treating with different population density and the availability of soil nutrients and water. The same species can exhibit different patterns of plasticity in response to different environmental factors. In the soil nutrient treatments, the plasticity pattern of S. collina could be described as “master‐of‐some”. However, in the soil‐water and population‐density treatments, it showed no significant difference from C. macrocarpum in the reaction norm for plasticity. It was similar to a “jack‐of‐all‐trades” plasticity pattern. Contrary to the previous conclusion that late successional species had higher reproductive allocation than early successional species, in this successional sequence, the late species had lower reproductive allocation in all treatments. Reproductive allocation of both species increased with the increase in water availability and also increased with a decrease in nutrient levels. However, density had no effect on reproductive allocation. Although the root:shoot ratio increased with decreasing water availability, there were no differences in the plasticity pattern for this trait in both species. Root:shoot ratio was, however, not significantly affected by nutrient availability and density. In a word, the plasticity patterns of invaders are adapted to the analyses of succession.
Effect of Hydrothermal Treatment of Rapeseed on Antioxidant Capacity of the Pressed Rapeseed Oil
Authors: Szydłowska‐Czerniak Aleksandra , Karlovits György , Sosna‐Sárdi Ágnes , Dianoczki Csilla , Szłyk Edward
Published: June 2009

Response surface methodology (RSM) was used to evaluate the quantitative effects of two independent variables, rapeseed moisture content and conditioning temperature, on the antioxidant capacity (AC) and total phenolic (TPC), tocopherol (TTC), and phosphorus contents (PC) in the pressed rapeseed oils. The mean AC results for the crude rapeseed oils ranged from 199.8 to 947.2 µmolTE/100 g. TPC and PC in the crude rapeseed oils correlated significantly (P < 0.01) and positively with AC of oils (R2 = 0.9498 and 0.4396, respectively). The experimental results of AC, TPC, and PC were close to the predicted values calculated from the polynomial response surface model equations (R2 = 0.9801, 0.9747 and 0.9165, respectively). The effect of oil processing temperature on AC and TPC was about 1.5 times greater than the effect of moisture level in rapeseed.
Are the effects of α‐glucosidase inhibitors on cardiovascular events related to elevated levels of hydrogen gas in the gastrointestinal tract?
Authors: Suzuki Yoshihiko , Sano Motoaki , Hayashida Kentaro , Ohsawa Ikuroh , Ohta Shigeo , Fukuda Keiichi
Published: June 2009

The major side‐effect of treatment with α‐glucosidase inhibitors, flatulence, occurs when undigested carbohydrates are fermented by colonic bacteria, resulting in gas formation. We propose that the cardiovascular benefits of α‐glucosidase inhibitors are partly attributable to their ability to neutralise oxidative stress via increased production of H2 in the gastrointestinal tract. Acarbose, which is an α‐glucosidase inhibitor, markedly increased H2 production, with a weaker effect on methane production. Our hypothesis is based on our recent discovery that H2 acts as a unique antioxidant, and that when inhaled or taken orally as H2‐dissolved water it ameliorates ischaemia–reperfusion injury and atherosclerosis development.
Mycobacterial adenosine kinase is not a typical adenosine kinase
Authors: Park Jae , Singh Bhag , Gupta Radhey S.
Published: June 2009

Adenosine kinase (AK) is only found in eukaryotes. Recently, a Mycobacterium tuberculosis (MTub) protein exhibiting greater sequence similarity to ribokinases (RK) was identified as AK. We have expressed AKs from MTub, human and Chinese hamster (CH) cells in Escherichia coli and also AK from human and MTub in AK‐deficient CH cells. While both E. coli and CH cells expressing mammalian AKs efficiently metabolized various adenosine analogs, those expressing MTub‐AK were completely inactive. The AK activity of the MTub protein was very low (50‐fold lower than E. coli RK) and it was not stimulated by phosphate or inhibited by several AK inhibitors. These results raise questions over MTub protein's true function and whether it functions as AK in cells.
TOE1 interacts with p53 to modulate its transactivation potential
Authors: Sperandio Sabina , Tardito Saverio , Surzycki Aleksandra , Latterich Martin , de Belle Ian
Published: June 2009

MINT‐7144884: P53 (uniprotkb:P04637) physically interacts (MI:0914) with TOE1 (uniprotkb:Q96GM8) by anti bait coimmunoprecipitation (MI:0006)
Late measures of microstructural alterations in severe neonatal hypoxic–ischemic encephalopathy by MR diffusion tensor imaging
Authors: Chan Kevin C. , Khong Pek‐lan , Lau Ho‐fai , Cheung Pik‐to , Wu Ed X.
Published: June 2009

Neonatal hypoxic–ischemic encephalopathy is a major cause of brain damage in infants, and is associated with periventricular white matter injury and chronic neurological dysfunctions. However, the mechanisms of the chronic white matter injury and reorganization are still unclear. In this study, in vivo diffusion tensor imaging (DTI) was employed to evaluate the late changes of white matter microstructural integrity in the rat brains at 10 weeks after severe neonatal hypoxic–ischemic insults at postnatal day 7. In the fractional anisotropy directionality map, qualitative evaluation showed that a dorsoventrally oriented fiber bundle extended from the corpus callosum into the cyst in the anterior brain, whilst the posterior peri‐infarct areas had similar fiber orientations as the contralateral internal capsule, optic tract and fimbria of hippocampus. Compared to the contralateral hemisphere, significantly higher fractional anisotropy, axial diffusivity and diffusion trace value were observed quantitatively in the distal end of the extended fiber bundle connecting the anterior and posterior white matters rostrocaudally. A significantly lower fractional anisotropy but higher axial and radial diffusivities and trace were also found in the ipsilateral corpus callosum, proximal external capsule and anterior commissure, while slightly lower fractional anisotropy and axial diffusivity were noticed in the ipsilateral internal capsule and optic nerve. It was suggested that increased fractional anisotropy, axial diffusivity and trace characterize white matter reorganization in chronic neonatal hypoxic–ischemic insults, whereas reduction in fractional anisotropy appears to characterize two types of white matter lesions, with significantly higher axial and radial diffusivities and trace being primary and slightly lower axial diffusivity being secondary. Combined with fractional anisotropy directionality map, in vivo DTI provides important indices to differentiate the chronic effects of severe neonatal hypoxic–ischemic injury and recovery globally, quantitatively and non‐invasively.
Endocytosis and spatial restriction of cell signaling
Authors: Disanza Andrea , Frittoli Emanuela , Palamidessi Andrea , Scita Giorgio
Published: June 2009

Endocytosis and recycling are essential components of the wiring enabling cells to perceive extracellular signals and transduce them in a temporally and spatially controlled fashion, directly influencing not only the duration and intensity of the signaling output, but also their correct location. Here, we will discuss key experimental evidence that support how different internalization routes, the generation of diverse endomembrane platforms, and cycles of internalization and recycling ensure polarized compartmentalization of signals, regulating a number of physiological and pathologically‐relevant processes in which the resolution of spatial information is vital for their execution.
Developmental changes in the acceptance of the five basic tastes in the first year of life
Authors: Schwartz Camille , Issanchou Sylvie , Nicklaus Sophie
Published: June 2009

Taste is a major determinant of children's food preferences, but its development is incompletely known. Thus, exploring infants' acceptance of basic tastes is necessary. The first objective was to evaluate the acceptance of tastes and their developmental changes over the first year. The second objective was to compare acceptance across tastes. The third objective was to evaluate global taste reactivity (within-subject variability of acceptance across tastes). Acceptance of sweet, salty, bitter, sour and umami tastes was assessed in three groups of forty-five 3-, 6- and 12-month-old infants using observations based on ingestion and liking scored by the experimenter. For each taste, four bottles were presented (water, tastant, tastant, water). Acceptance of each taste relative to water was defined using proportional variables based on ingestion or liking. Acceptance over the first year only evolved for sweet taste (marginal decrease) and salty taste (clear increase). At each age, sweet and salty tastes were the most preferred tastes. Reactions to umami were neutral. Sour and bitter tastes were the least accepted ones but rejected only when considering liking data. Ingestion and liking were complementary to assess taste acceptance. However, congruency between these measures rose during the first year. Moreover, with increasing age, reactions were more and more contrasted across tastes. Finally, during the first year, inter-individual variability increased for all tastes except salty taste. By enhancing knowledge of the development of taste acceptance the present study contributes to understand better food behaviour in infancy, the foundation of food behaviour in adulthood.
The history of the International Journal of Technology Assessment in Health Care
Authors: Jonsson Egon , Reiser Stanley J.
Published: June 2009

The 1970s and early 1980s was the period in which high technology medicine became dominant. It had begun in the late 1950s with the introduction of effective artificial respiratory technology. This gave physicians, patients, and families the hope that the threats to fundamental life processes such as breathing could be countered by technology, and the dilemma of both meeting its costs and the ethical challenges of how to remove it when its use no longer produced benefits.
Health technology assessment in the United States
Authors: Luce Bryan , Cohen Rebecca Singer
Published: June 2009

Objectives:To describe and explore the reasons for the current health technology assessment (HTA) landscape in the United States.

Methods:Relying on multiple historical literature and other documents as well as drawing on personal experiences and observations, we describe, evaluate, and explain the evolving and dynamic HTA-related evidence landscape.

Results:The present HTA-related landscape is a product of a dynamic, somewhat turbulent path in the United States. Many early aggressive federal efforts beginning in the 1970s were rejected in the 1980s only to be revived by the mid-1990s and continue to strengthen today, likely due to diffusing private sector political opposition from de-linking HTA from policy decisions (e.g., coverage, clinical guidelines) and omitting economic evaluation. Meanwhile, private sector HTA efforts have remained active during the entire period.

Conclusions:The current HTA-related landscape is at least as dynamic as it has been at any point in its turbulent 30-year history and is likely to continue as health reform in the US is debated once again.
Health technology assessment in Italy
Authors: Favaretti Carlo , Cicchetti Americo , Guarrera Giovanni , Marchetti Marco , Ricciardi Walter
Published: June 2009

Objectives: The aim of this study was to review the history of health technology assessment (HTA) in Italy.

Methods: Founded in 1978, the Italian National Health Service (NHS) has been strongly regionalized mainly after a constitutional reform, which started a devolution process. HTA started in the 1980s at the National Institute of Health and in a few University Hospitals, with a focus on big ticket technology: that process was driven by clinical engineers.

Results: In recent years, HTA is becoming an important tool for decision-making processes at central, regional, and local levels. In particular, the National Agency for Regional Health Services (AGENAS) and five regions (of twenty-one) are strongly committed to develop HTA initiatives connected with the planning process.

Conclusions: At the local level, the hospital-based HTA activity is probably the most important peculiarity of the country and the real driver of the HTA movement.
Gabriel–Ulmer duality and Lawvere theories enriched over a general base
Authors: LACK STEPHEN , POWER JOHN
Published: June 2009

Motivated by the search for a body of mathematical theory to support the semantics of computational effects, we first recall the relationship between Lawvere theories and monads onSet. We generalise that relationship fromSetto an arbitrary locally presentable category such asPosetand ωCpoor functor categories such as [Inj,Set] and [Inj, ωCpo]. That involves allowing the arities of Lawvere theories to be extended to being size-restricted objects of the locally presentable category. We develop a body of theory at this level of generality, in particular explaining how the relationship between generalised Lawvere theories and monads extends Gabriel–Ulmer duality.
Implementing a normalizer using sized heterogeneous types
Authors: ABEL ANDREAS
Published: June 2009

In the simply typed λ-calculus, a hereditary substitution replaces a free variable in a normal formrby another normal formsof typea, removing freshly created redexes on the fly. It can be defined by lexicographic induction onaandr, thus giving rise to a structurally recursive normalizer for the simply typed λ-calculus. We implement hereditary substitutions in a functional programming language with sized heterogeneous inductive types$\Fhat$, arriving at an interpreter whose termination can be tracked by the type system of its host programming language.
Big-step normalisation
Authors: ALTENKIRCH THORSTEN , CHAPMAN JAMES
Published: June 2009

Traditionally, decidability of conversion for typed λ-calculi is established by showing that small-step reduction is confluent and strongly normalising. Here we investigate an alternative approach employing a recursively defined normalisation function which we show to be terminating and which reflects and preserves conversion. We apply our approach to the simply typed λ-calculus with explicit substitutions and βη-equality, a system which is not strongly normalising. We also show how the construction can be extended to system T with the usual β-rules for the recursion combinator. Our approach is practical, since it does verify an actual implementation of normalisation which, unlike normalisation by evaluation, is first order. An important feature of our approach is that we are using logical relations to establish equational soundness (identity of normal forms reflects the equational theory), instead of the usual syntactic reasoning using the Church–Rosser property of a term rewriting system.
Categorical semantics for arrows
Authors: JACOBS BART , HEUNEN CHRIS , HASUO ICHIRO
Published: June 2009

Arrows are an extension of the well-established notion of a monad in functional-programming languages. This paper presents several examples and constructions and develops denotational semantics of arrows as monoids in categories of bifunctorsCop×C→C. Observing similarities to monads – which are monoids in categories of endofunctorsC→C– it then considers Eilenberg–Moore and Kleisli constructions for arrows. The latter yields Freyd categories, mathematically formulating the folklore claim ‘Arrows are Freyd categories.’
An induction principle for nested datatypes in intensional type theory
Authors: MATTHES RALPH
Published: June 2009

Nested datatypes are families of datatypes that are indexed over all types such that the constructors may relate different family members (unlike the homogeneous lists). Moreover, the argument types of the constructors refer to indices given by expressions in which the family name may occur. Especially in this case of true nesting, termination of functions that traverse these data structures is far from being obvious. A joint paper with A. Abel and T. Uustalu (Theor. Comput. Sci., 333 (1–2), 2005, pp. 3–66) proposed iteration schemes that guarantee termination not by structural requirements but just by polymorphic typing. They are generic in the sense that no specific syntactic form of the underlying datatype “functor” is required. However, there was no induction principle for the verification of the programs thus obtained, although they are well known in the usual model of initial algebras on endofunctor categories. The new contribution is a representation of nested datatypes in intensional type theory (more specifically, in the calculus of inductive constructions) that is still generic and covers true nesting, guarantees termination of all expressible programs, and has an induction principle that allows to prove functoriality of monotonicity witnesses (maps for nested datatypes) and naturality properties of iteratively defined polymorphic functions.
Vitamin D in older people
Authors: Logan Ian C , Witham Miles D
Published: June 2009

Vitamin D has been known to play a key role in calcium homeostasis and bone health for almost a century. Its main current clinical use is as an agent to prevent osteomalacia and reduce fragility fractures in older people. Vitamin D may however play a wider physiological role, with effects on cancer prevention, cardiovascular health and immune function. This review article will outline the physiological role of vitamin D, the disease processes that have been associated with insufficiency and examine whether vitamin D supplementation can ameliorate these disease processes in older people.
Improving the Visualization and Interpretation of Inhomogeneous Data Sets
Authors: Lodge Alexandra , Korte Monika
Published: June 2009

Time and again, geoscientists are faced with data sets that are inhomogeneous, either spatially, temporally, or both. This can lead to difficulties in deciding how best to visualize a data set and, more important, in deciding how to interpret models created from a particular data set. Using modeling of the Earth's magnetic field through archaeological time as an example, this brief report illustrates how Google Earth® may be used to improve the visualization and interpretation of inhomogeneous data sets.
Arthur L. Schmeltekopf Jr. (1932–2007)
Authors: Howard Carleton J.
Published: June 2009

Arthur Louis Schmeltekopf Jr. died of mesothelioma, a lung cancer associated with exposure to asbestos, at his home in Marshall, N.C., on 20 August 2007. He was born on 24 February 1932, in Kyle, Tex., to Arthur L. and Meta (Engelbrecht) Schmeltekopf and grew up nearby on the family farm. Art had an early interest in science. A dispute over the reactivity of alkali metals toward water led to an experiment at Kyle High School involving a chunk of sodium metal and a toilet in the boys' room. The resulting explosion shattered the toilet, creating a flood, multiple geysers and panic in the nearby girls' room, a displaced lid on the school's septic tank, and an enduring school legend.
Challenges to Understanding Ocean Circulation During the Last Glacial Maximum: Reconstruction of the Glacial Deep Ocean Circulation; Bremen, Germany, 4–7 November 2008
Authors: Paul André , Mulitza Stefan
Published: June 2009

The climate of the Last Glacial Maximum cold period (LGM; 23–19 thousand years ago) provides the means for evaluating the response of the climate system to large perturbations. It turns out that various coupled climate models similar to those used by the Intergovernmental Panel on Climate Change yield very different results on, for example, Atlantic Ocean meridional overturning rates during the LGM (see B. L. Otto‐Bliesner et al., Geophys. Res., Lett., 34, L12706, doi:10.1029/2007GL029475). A 3‐day workshop brought together about 30 international paleoclimatologists to create an inventory of existing paleoceanographic records for the LGM and explore the potential of individual proxies that provide information about the origin, distribution, and circulation rates of deep water and serve as a benchmark for testing climate models.
Developing and Implementing Protocols for Arctic Sea Ice Observations: Arctic Surface‐Based Sea Ice Observations: Integrated Protocols and Coordinated Data Acquisition Tromsø, Norway, 26–27 January 2009
Authors: Perovich Donald K. , Gerland Sebastian
Published: June 2009

The Arctic sea ice cover is diminishing. Over the past several years, not only has ice thinned but the extent of ice at the end of summer, and hence perennial ice, has declined markedly. These changes affect a wide range of issues and are important for a varied group of stakeholders, including Arctic coastal communities, policy makers, industry, the scientific community, and the public. Concerns range from the role of sea ice cover as an indicator and amplifier of climate change to marine transportation, resource extraction, and coastal erosion. To understand and respond to these ongoing changes, it is imperative to develop and implement consistent and robust observational protocols that can be used to describe the current state of the ice cover as well as future changes.
Eruption of Alaska Volcano Breaks Historic Pattern
Authors: Larsen Jessica , Neal Christina , Webley Peter , Freymueller Jeff , Haney Matthew , McNutt Stephen , Schneider David , Prejean Stephanie , Schaefer Janet , Wessels Rick
Published: June 2009

In the late morning of 12 July 2008, the Alaska Volcano Observatory (AVO) received an unexpected call from the U.S. Coast Guard, reporting an explosive volcanic eruption in the central Aleutians in the vicinity of Okmok volcano, a relatively young (∼2000‐year‐old) caldera. The Coast Guard had received an emergency call requesting assistance from a family living at a cattle ranch on the flanks of the volcano, who reported loud “thunder,” lightning, and noontime darkness due to ashfall. AVO staff immediately confirmed the report by observing a strong eruption signal recorded on the Okmok seismic network and the presence of a large dark ash cloud above Okmok in satellite imagery. Within 5 minutes of the call, AVO declared the volcano at aviation code red, signifying that a highly explosive, ash‐rich eruption was under way.
U.S. Science Agency Budgets Slated for Increases
Authors: Showstack Randy
Published: June 2009

The Obama administration released more details on 7 May about its proposed US$3.6 trillion federal budget for fiscal year (FY) 2010 and the planned significant increases for science agencies and for research and development (see Eos, 90(10), 83, 2009). The budget, which needs to be approved by Congress, includes $147.6 billion for research and development, an increase of $555 million, or 0.4%, above the enacted 2009 budget. In addition, the 2009 budget includes $18.3 billion in stimulus spending for research and development through the American Recovery and Reinvestment Act (ARRA).

John Holdren, director of the White House Office of Science and Technology Policy and Assistant to the President for Science and Technology, said the FY 2009 and proposed 2010 budgets are among the two largest research and development investments in the nation's history, in real terms. “We in the science and technology community have done better than just about any other constituency in the budget,” Holdren explained in a 7 May budget overview briefing, noting that virtually every science agency is doing better now than it was doing 2 years ago. “We have, in the White House, a president who gets it, believes and gets that investments in science and technology are just that: investments that will pay off.”
Outstanding Student Paper Awards
Authors: Anonymous
Published: June 2009

The following members received Outstanding Student Paper Awards at the 2008 AGU Fall Meeting in San Francisco, Calif. See also Outstanding Student Paper Awards published previously (Eos, 90(18), 159–160, and 90(19), 170).
Trace Fossil Analysis
Authors: Hasiotis Stephen T.
Published: June 2009

Today, the study of trace fossils—ichnology— is an important subdiscipline of geology at the interface of paleontology and sedimentology, mostly because of the efforts of Adolf Seilacher. His ability to synthesize various aspects of ichnology and produce a hierarchy of marine ichna and sedimentary facies has made ichnology useful worldwide in interpreting paleodiversity, rates of sedimentation, oxygenation of bottom water and sediment pore water, and depositional energy.

Seilacher's book Trace Fossil Analysis provides a glimpse into the mind, methodology, and insights of the father of modern ichnology, generated from his course notes as a professor and a guest lecturer. The title sounds misleading—readers looking for up‐to‐date principles and approaches to trace fossil analysis in marine and continental strata will be disappointed. In his preface, however, Seilacher clearly gives direction for the use of his text: “This is a course book— meaning that it is intended to confer not knowledge, but skill.” Thus, it is not meant as a total compilation of all trace fossils, ichnotaxonomy, ichnological interpretations, applications, or the most relevant and up‐to‐date references. Rather, it takes the reader on a personal journey, explaining how trace fossils are understood in the context of their three‐dimensional (3‐D) morphology and sedimentary facies.
New Study For Climate Modeling, Analyses, and Scenarios
Authors: Lowe Jason A. , Hewitt Chris D. , van Vuuren Detlef P. , Johns Tim C. , Stehfest Elke , Royer Jean‐François , van der Linden Paul J.
Published: June 2009

The European Commission is funding the ENSEMBLES project, which aims to provide policy makers with information from the latest climate modeling, analyses, and scenarios. Currently, the most comprehensive estimates of climate change are made using general circulation models (GCMs) and Earth system models, but these have been used mostly to simulate futures that do not factor in climate mitigation policy. The results of these simulations typically show global average warming greatly exceeding the European Union (EU) climate policy target of 2°C above preindustrial levels, with associated large impacts on human and natural systems.

To date, simple climate models typically have been used to assess the emissions trajectories that are required for meeting this target. The ENSEMBLES project is the first international multiclimate model intercomparison using a politically relevant aggressive mitigation scenario, referred to as E1 (Figures 1a and 1b). This scenario leads to a peak in the carbon dioxide (CO2) equivalent concentration in the atmosphere at around 535 parts per million (ppm) in 2045 before eventually stabilizing at around 450 ppm during the 22nd century. The climate models used are generally improved or extended versions of models contributing to the Intergovernmental Panel on Climate Change's (IPCC) Fourth Assessment Report.
Linking Extreme Weather to Climate Variability and Change: International Group on Attribution of Climate‐Related Events (ACE); Boulder, Colorado, 26 January 2009
Authors: Stott Peter , Trenberth Kevin
Published: June 2009

Climate change is likely to be manifested on societies around the world mainly through changes in extremes. As a result, the scientific community faces an increasing demand for regularly updated appraisals of evolving climate conditions and extreme weather. Such information would be immensely beneficial for adaptation planning.

A group of climate scientists representing the United Kingdom, the United States, Australia, Canada, and South Africa assembled on 26 January 2009 at the National Center for Atmospheric Research (NCAR), in Colorado, to discuss how to meet this challenge. This first meeting of the International Group on Attribution of Climate‐Related Events (ACE) was sponsored by the Science and Innovation Network of the U.K. Foreign and Commonwealth Office (FCO) and NCAR and was organized in collaboration with the U.S. National Oceanic and Atmospheric Administration (NOAA), the Met Office Hadley Centre, and the University of Oxford.
An Alaska Soil Carbon Database: Database Collaborator's Meeting; Fairbanks, Alaska, 4 March 2009
Authors: Johnson Kristofer , Harden Jennifer
Published: June 2009

Soil carbon pools in northern high‐latitude regions and their response to climate changes are highly uncertain, and collaboration is required from field scientists and modelers to establish baseline data for carbon cycle studies. The Global Change Program at the U.S. Geological Survey has funded a 2‐year effort to establish a soil carbon network and database for Alaska based on collaborations from numerous institutions.

To initiate a community effort, a workshop for the development of an Alaska soil carbon database was held at the University of Alaska Fairbanks. The database will be a resource for spatial and biogeochemical models of Alaska ecosystems and will serve as a prototype for a nationwide community project: the National Soil Carbon Network (http://www.soilcarb.net). Studies will benefit from the combination of multiple academic and government data sets. This collaborative effort is expected to identify data gaps and uncertainties more comprehensively. Future applications of information contained in the database will identify specific vulnerabilities of soil carbon in Alaska to climate change, disturbance, and vegetation change.
Principles of Metamorphic Petrology
Authors: Williams Michael L.
Published: June 2009

The field of metamorphic petrology has seen spectacular advances in the past decade, including new X‐ray mapping techniques for characterizing metamorphic rocks and minerals, new internally consistent thermobarometers, new software for constructing and viewing phase diagrams, new methods to date metamorphic processes, and perhaps most significant, revised petrologic databases and the ability to calculate accurate phase diagrams and pseudosections. These tools and techniques provide new power and resolution for constraining pressure‐temperature (P‐T) histories and tectonic events.

Two books have been fundamental for empowering petrologists and structural geologists during the past decade. Frank Spear's Metamorphic Phase Equilibria and Pressure‐Temperature‐Time Paths, published in 1993, builds on his seminal papers to provide a quantitative framework for P‐T path analysis. Spear's book lays the foundation for modern quantitative metamorphic analysis. Cees Passchier and Rudolph Trouw's Microtectonics, published in 2005, with its superb photos and figures, provides the tools and the theory for interpreting deformation textures and inferring deformation processes.
Hans Island: Meteorological Data From an International Borderline
Authors: Wilkinson J. P. , Gudmandsen P. , Hanson S. , Saldo R. , Samelson R. M.
Published: June 2009

Just after midnight on 28 August 1871, the vessel U.S.S. Polaris of the North Polar Expedition, led by C. F. Hall, sailed past a small, uncharted island in the middle of Kennedy Channel [Davis, 1876]. This narrow channel is one of several such marine passages and sounds located between Canada's Ellesmere Island and Greenland that combined together, form Nares Strait. Because of the dense fog at the time, the extent of the island could not be gauged. On the vessel's return voyage almost a year later, on 13 August 1872, the Polaris again passed this island. Expedition notes [e.g., Davis, 1876] reveal that the island was given the name Hans Island, or Hans Ø in Danish, in honor of Hans Hendrik (1834–1889) [see Hendrik, 1878], a Greenlander who assisted the expedition and four others to the region (led by E. K. Kane, 1853–1855; I. I. Hayes, 1860–1861; G. S. Nares, 1875–1876; and N. A. E. Nordenskjöld, 1883).
Crystal structure of an inverting GH 43 1,5-α-L-arabinanase from Geobacillus stearothermophilus complexed with its substrate
Authors: Alhassid Anat , Ben-David Alon , Tabachnikov Orly , Libster Dima , Naveh Einat , Zolotnitsky Gennady , Shoham Yuval , Shoham Gil
Published: June 2009

Arabinanases are glycosidases that hydrolyse α-(1→5)- arabinofuranosidic linkages found in the backbone of the pectic polysaccharide arabinan. Here we describe the biochemical characterization and the enzyme–substrate crystal structure of an inverting family 43 arabinanase from Geobacillus stearothermophilus T-6 (AbnB). Based on viscosity and reducing power measurements, and based on product analysis for the hydrolysis of linear arabinan by AbnB, the enzyme works in an endo mode of action. Isothermal titration calorimetry studies of a catalytic mutant with various arabino-oligosaccharides suggested that the enzyme active site can accommodate at least five arabinose units. The crystal structure of AbnB was determined at 1.06 Å (1 Å=0.1 nm) resolution, revealing a single five-bladed-β-propeller fold domain. Co-crystallization of catalytic mutants of the enzyme with different substrates allowed us to obtain complex structures of AbnBE201A with arabinotriose and AbnBD147A with arabinobiose. Based on the crystal structures of AbnB together with its substrates, the position of the three catalytic carboxylates: Asp27, the general base; Glu201, the general acid; and Asp147, the pKa modulator, is in agreement with their putative catalytic roles. In the complex structure of AbnBE201A with arabinotriose, a single water molecule is located 2.8 Å from Asp27 and 3.7 Å from the anomeric carbon. The position of this water molecule is kept via hydrogen bonding with a conserved tyrosine (Tyr229) that is 2.6 Å distant from it. The location of this molecule suggests that it can function as the catalytic water molecule in the hydrolysis reaction, resulting in the inversion of the anomeric configuration of the product.
The haplotype of the growth-differentiation factor 15 gene is associated with left ventricular hypertrophy in human essential hypertension
Authors: Wang Xiaojian , Yang Xu , Sun Kai , Chen Jingzhou , Song Xiaodong , Wang Hu , Liu Zhe , Wang Changxin , Zhang Channa , Hui Rutai
Published: June 2009

GDF15 (growth-differentiation factor 15) is a novel antihypertrophic factor which is induced in the heart in response to pressure overload and plays an important regulatory role in the process of hypertrophy. In the present study, we have investigated the relationship between GDF15 gene variants and left ventricular hypertrophy in human essential hypertension. A community-based hypertensive population sample of 1527 individuals (506 men and 1021 women) was genotyped for three GDF15 genetic variants, including one tag variant −3148C>G (rs4808793) and two exonic variants +157A>T (rs1059369) and +2438C>G (rs1058587). The effects of those variants on gene expression were studied by use of luciferase reporter assays and the determination of plasma GDF15 levels. Only the tag variant −3148G was significantly associated with a lower risk of left ventricular hypertrophy [odds ratio=0.75 (95% confidence interval, 0.63–0.89); P=0.0009]. Multiple regression analyses confirmed that −3148G predicted the decrease in left ventricular end-diastolic diameter (β=−0.10, P=0.0001), end-systolic diameter (β=−0.09, P=0.0007), mass (β=−0.11, P<0.0001) and indexed mass (β=−0.12, P<0.0001). These effects were independent of conventional factors, including gender, age, body surface area, blood pressure, diabetes, cigarette smoking and alcohol consumption. The transcription activity of the −3148G-containing construct was increased 1.45-fold (P=0.015) at baseline and 1.73-fold (P=0.008) after stimulation with phenylephrine when compared with the −3148C construct. The −3148G allele was also associated with a significant increase in the plasma GDF15 level in hypertensive subjects (P=0.04). In conclusion, the results show that a promoter haplotype containing the −3148G variant increases GDF15 transcription activity and is associated with favourable left ventricular remodelling in human essential hypertension.
Applications of Exercise Science in Dysphagia Rehabilitation
Authors: Burkhead Lori M.
Published: June 2009

Dysphagia clinicians are charged with improving strength, skill, and endurance in order to rehabilitate oropharyngeal swallowing. The obvious method is exercise training. Dysphagia clinicians often use trial-and-error and experience to develop effective regimens. This article is intended to invoke broader and more accurate perspectives from our colleagues in exercise science.
Effects of Chemoradiotherapy on Tongue Function in Patients With Head and Neck Cancer
Authors: Lazarus Cathy L.
Published: June 2009

In this review article, the effects of radiotherapy ± chemotherapy on tissues and on oropharyngeal swallowing are reviewed. In addition, normal tongue function for swallowing is reviewed, as are the effects of tongue exercise programs designed to improve tongue strength and swallow functioning. Current literature on swallow exercise programs for head and neck cancer patients is provided. Also discussed are potential new avenues for research in this population.