bluuebunny/crossref_metadata_2025 huggingface dataset:
Using Early-Stage Assessment to Reduce the Financial Risks and Perceived Barriers of Sustainable Buildings
Authors: Ranaweera Renuka , Crawford Robert H
Published: June 2010

For sustainable buildings to become mainstream they must demonstrate not only improved environmental performance but also financial performance, benefiting both end users and investors. The perceived financial constraints and risks are often major barriers to sustainable design. This paper discusses the application of a new tool that formalizes the traditionally intuitive-based early-stage decision making processes and assesses the potential for creating a financially feasible best-practice sustainable building across a range of environmental, social and economic parameters, using the limited data available at the outset of a project. It considers the total cost of ownership, demonstrating the link between the recurrent and capital costs. A detailed feasibility assessment of those areas where greatest potential for improving environmental and financial performance exists can then be carried out, saving a considerable amount of time, money and effort otherwise spent on looking at all possible strategies for achieving a sustainable outcome. This approach also identifies areas where incorporating environmental strategies might be financially risky, reassuring investors and developers by reducing investment risks. By reducing some of these risks and perceived barriers to sustainable building development, it is hoped that clients and investors will be further encouraged to adopt a more sustainable approach to their building projects.
Sustainable Playing Fields: 8 Steps to an Easy Field Facelift
Authors: Fowler Jeffrey T
Published: June 2010

According to the National Safe Kids Coalition, 30 million young people play organized sports in the United States annually. One million of them are treated annually in an emergency room and 50% of those treated injuries are preventable. As more people are encouraged to be active in their daily lives to combat health issues and obesity, an increased demand on recreational and sport facilities and playing surfaces will increase the degradation of the playing surfaces and thereby increase the risk of sports related injuries. Continual maintenance and upkeep of playing surfaces can be become a sinkhole for budgeted dollars if a facility use plan and a maintenance plan are not in place for dealing with the increase in play on athletic fields and parks. So why do the statistics of athletic injury matter? As we manage sports fields, our jobs are to reduce the number of injuries on our playing surfaces. We need to make our fields as safe as we can. There are a number of agronomic practices that many times are overlooked or forgotten about when managing sports turf. “8 Steps to an Easy Field Facelift” is a list of the management practices we can employ that will sustain our fields safer for play for a longer period of time at minimal cost.
The Wister Education Center and Greenhouse: Uniting Program and Process, History and Mission, Architecture, and Sustainability on the Swarthmore College Campus
Authors: Russoniello Daniel G
Published: June 2010

Swarthmore College honors its Quaker principles by educating students to be responsible world citizens and through good stewardship of its land and building resources. Today this tradition of citizenship and stewardship is reflected in the College's purchasing of sustainable power and construction choices. The new 5,200 square foot Wister Education Center and Greenhouse for The Scott Arboretum of Swarthmore College is the most recent and far-reaching green building on campus and serves as a model for integrating sustainable design with the function, mission, and architecture of the institution.
CHRONIC MYELOPROLIFERATIVE NEOPLASMS: A COLLABORATIVE APPROACH
Authors: Pieri Lisa , Guglielmelli Paola , Vannucchi Alessandro Maria
Published: June 2010

The classic chronic myeloproliferative neoplasms (MPN) include different entities that pose significant challenges for their optimal diagnosis, treatment and overall management. Polycythemia Vera and Essential Thrombocythemia are the most common among chronic myeloproliferative neoplasms (MPNs); major causes of morbidity and mortality are represented by arterial and venous thrombosis, as well as evolution to myelofibrosis or transformation to acute leukemia. However, survival is only minimally affected. Therapy aims at reducing the rate of thrombosis without increasing the risk of hematologic transformation which could be caused by exposure to cytotoxic drugs. On the other hand, survival is significantly reduced in primary myelofibrosis, and the clinical manifestations may be disabling. In the absence of therapies with the potential of curing the disease, a careful risk-oriented approach is employed for stratifying patients to the most appropriate, currently available, therapeutic options. In this brief review, we will discuss some of the key issues that can arise along the clinical course of MPNs and require an integrated, strictly patient-oriented, approach.
Measures of Noncompactness in the Study of Asymptotically Stable and Ultimately Nondecreasing Solutions of Integral Equations
Authors: Appell Jürgen , Banaś Józef , Merentes Nelson
Published: June 2010

We introduce a new class of measures of noncompactness related to asymptotic stability and ultimate monotonicity in the space of continuous and bounded functions on an unbounded interval. With help of those measures of noncompactness and a ﬁxed point theorem of Darbo type we investigate the existence of asymptotically stable and ultimately nondecreasing solutions of some quadratic functional integral equations of Hammerstein–Volterra type.
Optimal Control of Planar Flow of Incompressible Non-Newtonian Fluids
Authors: Wachsmuth Daniel , Roubíček Tomáš
Published: June 2010

We consider an optimal control problem for the evolutionary ﬂow of incompressible non-Newtonian ﬂuids in a two-dimensional domain. The existence of optimal controls is proven. Furthermore, we investigate ﬁrst-order necessary as well as second-order suﬃcient optimality conditions. The analysis relies on new results providing solutions with bounded gradients for the ﬂow equations.
Pour l'introduction de l'histoire des sciences dans l'enseignement du second cycle
Authors: Lacombe Geneviève
Published: June 2010

Si la place officielle de l'histoire de la biologie dans l'enseignement du second cycle est dérisoire, il est toujours possible, lorsqu’on est convaincu de son intérêt, de saisir les occasions de l'introduire, fût-ce de façon furtive.

Les quelques exemples présentés ici correspondent à des essais échelonnés dans le temps conduits par des professeurs de plusieurs disciplines du lycée de Saint-Gaudens ; le plus souvent lancés sur un coup de coeur, ils nous ont permis de "dévorer" des documents, de partager nos connaissances, de confronter nos points de vue. Lieu d'interdisciplinarité, l'histoire des sciences est pour chacun de nous source de culture. Sans doute, notre pratique – inscrite dans les contraintes de l'institution – n'est-elle qu'un patchwork de tentatives partielles, miettes dépareillées et parfois ridiculement ambitieuses. Conscients de privilégier une seule facette de l'histoire de la biologie, nous pensons avoir toutefois aidé nos élèves (en particulier les "littéraires") à mieux comprendre et à mieux aimer la biologie.
L'histoire de la physique peut-elle éclairer les obstacles épistémologiques?
Authors: Rosmorduc Jean
Published: June 2010

Can the history of physics help us to understand epistemological obstacles ?

The concept of epistemological obstacle as defined by G. Bachelard grew out of his work on the history of physics and chemistry as well as out of his own experience as a physics teacher. The present article analyses the evolution of physics from its beginnings to the present day and points out some of the problems which historians of physics meet. Some instances of epistemological obstacles are given in the course of the article.
Characterization of Tropospheric Emission Spectrometer (TES) CO2 for carbon cycle science
Authors: Kulawik S. S. , Jones D. B. A. , Nassar R. , Irion F. W. , Worden J. R. , Bowman K. W. , Machida T. , Matsueda H. , Sawa Y. , Biraud S. C. , Fischer M. L. , Jacobson A. R.
Published: June 2010

Abstract. We present carbon dioxide (CO2) estimates from the Tropospheric Emission Spectrometer (TES) on the EOS-Aura satellite launched in 2004. For observations between 40° S and 45° N, we find about 1 degree of freedom with peak sensitivity at 511 hPa. The estimated error is ~10 ppm for a single target and 1.3–2.3 ppm for monthly averages on spatial scales of 20°×30°. Monthly spatially-averaged TES data from 2005–2008 processed with a uniform initial guess and prior are compared to CONTRAIL aircraft data over the Pacific ocean, aircraft data at the Southern Great Plains (SGP) ARM site in the southern US, and the Mauna Loa and Samoa surface stations. Comparisons to Mauna Loa data show a correlation of 0.92, a standard deviation of 1.3 ppm, a predicted error of 1.2 ppm, and a ~2% low bias, which is subsequently corrected. Comparisons to SGP aircraft data over land show a correlation of 0.67 and a standard deviation of 2.3 ppm. TES data between 40° S and 45° N for 2006–2007 are compared to surface flask data, GLOBALVIEW, the Atmospheric Infrared Sounder (AIRS), and CarbonTracker. Comparison to GLOBALVIEW-CO2 ocean surface sites shows a correlation of 0.60 which drops when TES is offset in latitude, longitude, or time. At these same locations, TES shows a 0.62 and 0.67 correlation to CarbonTracker at the surface and 5 km, respectively. We also conducted an observing system simulation experiment to assess the potential utility of the TES data for inverse modeling of CO2 fluxes. We find that if biases in the data and model are well characterized, the averaged data have the potential to provide sufficient information to significantly reduce uncertainty on annual estimates of regional CO2 sources and sinks. Averaged pseudo-data at 10°×10° reduced uncertainty in flux estimates by as much as 70% for some tropical regions.
The complex dynamics of the seasonal component of Earth's surface temperature
Authors: Vecchio A. , Capparelli V. , Carbone V.
Published: June 2010

Abstract. The dynamics of the climate system has been investigated by analyzing the complex seasonal oscillation of monthly averaged temperatures recorded at 1167 stations covering the whole USA. We found the presence of an orbit-climate relationship on time scales remarkably shorter than the Milankovitch period related to the nutational forcing. The relationship manifests itself through occasional destabilization of the phase of the seasonal component due to the local changing of balance between direct insolation and the net energy received by the Earth. Quite surprisingly, we found that the local intermittent dynamics is modulated by a periodic component of about 18.6 yr due to the nutation of Earth, which represents the main modulation of the Earth's precession. The global effect in the last century results in a cumulative phase-shift of about 1.74 days towards earlier seasons, in agreement with the phase shift expected from Earth's precession. The climate dynamics of the seasonal cycle can be described through a nonlinear circle-map, indicating that the destabilization process can be associated to intermittent transitions from quasi-periodicity to chaos.
Quantitative relation between PMSE and ice mass density
Authors: Kirkwood S. , Hervig M. , Belova E. , Osepian A.
Published: June 2010

Abstract. Radar reflectivities associated with Polar Mesosphere Summer Echoes (PMSE) are compared with measurements of ice mass density in the mesopause region. The 54.5 MHz radar Moveable Atmospheric Radar for Antarctica (MARA), located at the Wasa/Aboa station in Antarctica (73° S, 13° W) provided PMSE measurements in December 2007 and January 2008. Ice mass density was measured by the Solar Occultation for Ice Experiment (SOFIE). The radar operated continuously during this period but only measurements close to local midnight are used for comparison, to coincide with the local time of the measurements of ice mass density. The radar location is at high geographic latitude but low geomagnetic latitude (61°) and the measurements were made during a period of very low solar activity. As a result, background electron densities can be modelled based on solar illumination alone. We find a close correlation between the time and height variations of radar reflectivity and ice mass density, at all PMSE heights, from 80 km up to 95 km. A quantitative expression relating radar reflectivities to ice mass density is found, including an empirical dependence on background electron density. Using this relation, we can use PMSE reflectivities as a proxy for ice mass density, and estimate the daily variation of ice mass density from the daily variation of PMSE reflectivities. According to this proxy, ice mass density is maximum around 05:00–07:00 LT, with lower values around local noon, in the afternoon and in the evening. This is consistent with the small number of previously published measurements and model predictions of the daily variation of noctilucent (mesospheric) clouds and in contrast to the daily variation of PMSE, which has a broad daytime maximum, extending from 05:00 LT to 15:00 LT, and an evening-midnight minimum.
The effects of mesoscale regions of precipitation on the ionospheric dynamics, electrodynamics and electron density in the presence of strong ambient electric fields
Authors: de Boer J. D. , Noël J.-M. A. , St.-Maurice J.-P.
Published: June 2010

Abstract. We have developed a new high resolution two-dimensional model of the high latitude ionosphere in which nonlinear advection terms are closely coupled with the electrodynamics. The model provides a self-consistent description of the ionospheric feedback on the electrodynamical perturbations produced by auroral arc-related particle precipitation in regions with strong ambient electric fields. We find in particular that a heretofore neglected ion Pedersen advection term can introduce considerable changes in the electron density profile, the current density distribution, the conductivities and the electron temperatures. We find that the convective effects can carry the ionisation more than 150 km outside the precipitation region in a few minutes, with attendant large changes in the current distribution and E-region densities that become enhanced outside the region of particle precipitation. The production of a tongue of ionisation that slowly decays outside the auroral boundaries contrasts with the sharp geometric cut-off and associated stronger current densities found in previous studies.
The role of tectonic uplift, climate, and vegetation in the long-term terrestrial phosphorous cycle
Authors: Buendía C. , Kleidon A. , Porporato A.
Published: June 2010

Abstract. Phosphorus (P) is a crucial element for life and therefore for maintaining ecosystem productivity. Its local availability to the terrestrial biosphere results from the interaction between climate, tectonic uplift, atmospheric transport, and biotic cycling. Here we present a mathematical model that describes the terrestrial P-cycle in a simple but comprehensive way. The resulting dynamical system can be solved analytically for steady-state conditions, allowing us to test the sensitivity of the P-availability to the key parameters and processes. Given constant inputs, we find that humid ecosystems exhibit lower P availability due to higher runoff and losses, and that tectonic uplift is a fundamental constraint. In particular, we find that in humid ecosystems the biotic cycling seem essential to maintain long-term P-availability. The time-dependent P dynamics for the Franz Josef and Hawaii chronosequences show how tectonic uplift is an important constraint on ecosystem productivity, while hydroclimatic conditions control the P-losses and speed towards steady-state. The model also helps describe how, with limited uplift and atmospheric input, as in the case of the Amazon Basin, ecosystems must rely on mechanisms that enhance P-availability and retention. Our novel model has a limited number of parameters and can be easily integrated into global climate models to provide a representation of the response of the terrestrial biosphere to global change.
Contribution of riverine nutrients to the silicon biogeochemistry of the global ocean – a model study
Authors: Bernard C. Y. , Dürr H. H. , Heinze C. , Segschneider J. , Maier-Reimer E.
Published: June 2010

Abstract. Continental shelf seas are known to support a large fraction of the global primary production. Yet, continental shelf areas are mostly ignored or neglected in global biogeochemical models. A number of processes that control the transfer of dissolved nutrients from rivers to the open ocean remain poorly understood. This applies in particular to dissolved silica which drives the growth of diatoms that form a large part of the phytoplankton biomass and are thus an important contributor to export production of carbon. Here, the representation of the biogeochemical cycling along continents is improved by coupling a high resolution database of riverine fluxes of nutrients to the global biogeochemical ocean general circulation model HAMOCC5-OM. Focusing on silicon (Si), but including the whole suite of nutrients – carbon (C), nitrogen (N) and phosphorus (P) in various forms – inputs are implemented in the model at coastal coupling points using the COSCAT global database of 156 mega-river-ensemble catchments from Meybeck et al. (2006). The catchments connect to the ocean through coastal segments according to three sets of criteria: natural limits, continental shelf topography, and geophysical dynamics. According to the model the largest effects on nutrient concentrations occur in hot spots such as the Amazon plume, the Arctic – with high nutrient inputs in relation to its total volume, and areas that encounter the largest increase in human activity, e.g., Southern Asia.
Millennium-long summer temperature variations in the European Alps as reconstructed from tree rings
Authors: Corona C. , Guiot J. , Edouard J. L. , Chalié F. , Büntgen U. , Nola P. , Urbinati C.
Published: June 2010

Abstract. This paper presents a reconstruction of the summer temperatures over the Greater Alpine Region (44.05°–47.41° N, 6.43°–13° E) during the last millennium based on a network of 38 multi-centennial larch and stone pine chronologies. Tree ring series are standardized using an Adaptative Regional Growth Curve, which attempts to remove the age effect from the low frequency variations in the series. The proxies are calibrated using the June to August mean temperatures from the HISTALP high-elevation temperature time series spanning the 1818–2003. The method combines an analogue technique, which is able to extend the too short tree-ring series, an artificial neural network technique for an optimal non-linear calibration including a bootstrap technique for calculating error assessment on the reconstruction. About 50% of the temperature variance is reconstructed. Low-elevation instrumental data back to 1760 compared to their instrumental target data reveal divergence between (warmer) early instrumental measurements and (colder) proxy estimates. The proxy record indicates cool conditions, from the mid-11th century to the mid-12th century, related to the Oort solar minimum followed by a short Medieval Warm Period (1200–1420). The Little Ice Age (1420–1830) appears particularly cold between 1420 and 1820 with summers that are 0.8 °C cooler than the 1901–2000 period. The new record suggests that the persistency of the late 20th century warming trend is unprecedented. It also reveals significant similarities with other alpine reconstructions.
Dynamic Magnetic Properties of Ferroic Films, Multilayers, and Patterned Elements
Authors: Stamps Robert L.
Published: June 2010

Modification and control of material properties through careful manipulation of geometry on nano‐ and sub‐nanometer length scales is a cornerstone of modern materials science and technology. An exciting area in which these concepts have provided exceptional advances has been magnetoelectronics and nanomagnetism. Important scales in magnetic metals are conduction spin diffusion lengths and distances over which local moments correlate. Advanced techniques now allow for the creation of structures patterned on these length scales in three dimensions. The focus of this article is on magnetic structures whose dynamic properties can be strongly modified by ion bombardment and lithographic patterning. Examples are given of how microwave frequency properties can be tuned with external fields, how factors controlling magnetic switching can be controlled, and how manipulation of magnetic domain walls can be used to reveal new and surprising phenomena.
Enhanced Photocatalytic Activity using Layer‐by‐Layer Electrospun Constructs for Water Remediation
Authors: Lee Jung Ah , Nam Yoon Sung , Rutledge Gregory C. , Hammond Paula T.
Published: June 2010

Endocrine disruptors such as bisphenol A (BPA) are environmental pollutants that interfere with the body's endocrine system because of their structural similarity to natural and synthetic hormones. Due to their strong oxidizing potential to decompose such organic pollutants, colloidal metal oxide photocatalysts have attracted increasing attention for water detoxification. However, achieving both long‐term physical stability and high efficiency simultaneously with such photocatalytic systems poses many challenges. Here a layer‐by‐layer (LbL) deposition approach is reported for immobilizing TiO2 nanoparticles (NPs) on a porous support while maintaining a high catalytic efficiency for photochemical decomposition of BPA. Anatase TiO2 NPs ≈7 nm in diameter self‐assemble in consecutive layers with positively charged polyhedral oligomeric silsesquioxanes on a high surface area, porous electrospun polymer fiber mesh. The TiO2 LbL nanofibers decompose approximately 2.2 mg BPA per mg of TiO2 in 40 h of illumination (AM 1.5G illumination), maintaining first‐order kinetics with a rate constant (k) of 0.15 h−1 for over 40 h. Although the colloidal TiO2 NPs initially show significantly higher photocatalytic activity (k ≈ 0.84 h−1), the rate constant drops to k ≈ 0.07 h−1 after 4 h of operation, seemingly due to particle agglomeration. In the BPA solution treated with the multilayered TiO2 nanofibers for 40 h, the estrogenic activity, based on human breast cancer cell proliferation, is significantly lower than that in the BPA solution treated with colloidal TiO2 NPs under the same conditions. This study demonstrates that water‐based, electrostatic LbL deposition effectively immobilizes and stabilizes TiO2 NPs on electrospun polymer nanofibers for efficient extended photochemical water remediation.
Multifunctional Shape‐Memory Polymers
Authors: Behl Marc , Razzaq Muhammad Yasar , Lendlein Andreas
Published: June 2010

The thermally‐induced shape‐memory effect (SME) is the capability of a material to change its shape in a predefined way in response to heat. In shape‐memory polymers (SMP) this shape change is the entropy‐driven recovery of a mechanical deformation, which was obtained before by application of external stress and was temporarily fixed by formation of physical crosslinks. The high technological significance of SMP becomes apparent in many established products (e.g., packaging materials, assembling devices, textiles, and membranes) and the broad SMP development activities in the field of biomedical as well as aerospace applications (e.g., medical devices or morphing structures for aerospace vehicles). Inspired by the complex and diverse requirements of these applications fundamental research is aiming at multifunctional SMP, in which SME is combined with additional functions and is proceeding rapidly. In this review different concepts for the creation of multifunctionality are derived from the various polymer network architectures of thermally‐induced SMP. Multimaterial systems, such as nanocomposites, are described as well as one‐component polymer systems, in which independent functions are integrated. Future challenges will be to transfer the concept of multifunctionality to other emerging shape‐memory technologies like light‐sensitive SMP, reversible shape changing effects or triple‐shape polymers.
Caring for nonhuman primates in biomedical research facilities: scientific, moral and emotional considerations
Authors: Coleman Kristine
Published: June 2010

Animal care for nonhuman primates (NHPs) in biomedical facilities has undergone major changes in the past few decades. Today, most primate facilities have dedicated and highly trained animal care technicians who go to great efforts to ensure the physiological and psychological well being of the primates in their charge. These caretakers work closely with the animals and, as a result, often develop strong relationships with them. Once discouraged and considered a potential threat to scientific objectivity, such positive relationships are now seen as important components to animal care. Positive interactions between caretakers and primates can benefit the primates by reducing their stress and improving their overall well being which can, in turn, help the scientific endeavor. Further, providing the best possible care is our moral responsibility. However, there can also be emotional costs associated with caring for NHPs in research facilities, particularly when animals become ill or have to be euthanized. Facilities can do much to help ease this conflict. High‐quality and conscientious animal care is good for the animals, science, and public perception of research facilities. Am. J. Primatol. 73:220–225, 2011. © 2010 Wiley‐Liss, Inc.
The ontogeny of handling hard‐to‐process food in wild brown capuchins (Cebus apella apella): evidence from foraging on the fruit ofMaximiliana maripa
Authors: Gunst Noëlle , Leca Jean‐Baptiste , Boinski Sue , Fragaszy Dorothy
Published: June 2010

We examined age‐related differences in wild brown capuchins' foraging efficiency and the food‐processing behaviors directed toward maripa palm fruit (Maximiliana maripa). A detailed comparison of the different foraging techniques showed that plucking the fruit from the infructescence constituted the main difficulty of this task. Foraging efficiency tended to increase with age, with a threshold at which sufficient strength allowed immatures by the age of three to reach adult‐level efficiency. Youngsters spent more time than older individuals browsing the infructescence and pulling the fruit in an attempt to harvest it. Infants tried to compensate for their inability to pluck fruit by adopting alternative strategies but with low payback, such as gnawing unplucked fruit and opportunistically scrounging others' partially processed food. Although around 2 years of age, young capuchins exhibited all of the behaviors used by adults, they did not reach adult‐level proficiency at feeding on maripa until about 3 years (older juveniles). We compared this developmental pattern with that of extractive foraging on beetle larvae (Myelobiasp.) hidden in bamboo stalks, a more difficult food for these monkeys [Gunst N, Boinski S, Fragaszy DM. Behaviour 145:195–229, 2008]. For maripa, the challenge was mainly physical (plucking the fruit) once a tree was encountered, whereas for larvae, the challenge was primarily perceptual (locating the hidden larvae). For both foods, capuchins practice for years before achieving adult‐level foraging competence, and the timeline is extended for larvae foraging (until 6 years) compared with maripa (3 years). The differing combinations of opportunities and challenges for learning to forage on these different foods illustrate how young generalist foragers (i.e. exploiting a large number of animal and plant species) may compensate for their low efficiency in extractive foraging tasks by showing earlier competence in processing less difficult but nutritious foods, such as maripa fruit. Am. J. Primatol. 72:960–973, 2010. © 2010 Wiley‐Liss, Inc.
Kalorimetrische Untersuchungen an Biopolymeren und Aggregaten von Phospholipiden
Authors: Ackermann Theodor
Published: June 2010

Die in wäßriger Lösung ablaufenden Strukturumwandlungen von Biopolymeren sind komplexe Vorgänge, deren Mechanismus nur durch die Kopplung verschiedner Teilprozesse erklärt werden kann. Eine spektroskopische Analyse der Systemzustände ist oft mit beträchtlichem Aufwand verbunden. Für eine orientierende Charakterisierung des Systemverhaltens erweist sich in vielen Fällen eine kalorimetrische Untersuchung als ausreichend. Diese Messung liefert wichtige Aussagen über die Stabilität der Ausgangszustände und über die Kooperativität des Gesamtvorganges. Aus den thermodynamischen Parametern des untersuchten Systems ergeben sich Hinweise auf den strukturbestimmenden Einfluß der verschiedenen Typen inter‐ und intramolekularer Wechselwirkungen. Dies gilt nicht nur für Lösungen von Biopolymeren und analogen Modellsubstanzen, sondern auch für Lösungen von Komplexen aus Biopolymeren und niedermolekularen Liganden sowie für wäßrige Suspensionen selbstaggregierender Phospholipide. Möglichkeiten und Grenzen der Anwendung kalorimetrischer Meßverfahren werden an typischen Beispielen aus der Vielzahl der untersuchten Polypeptid und Polynucleotidsysteme und der Phospholipid‐Doppelschichtsysteme erläutert. Es wird auch auf die bei Messungen an verdünnten Lösungen zu beachtenden methodischen Besonderheiten hingewiesen, wobei die in neuerer Zeit erzielten meßtechnischen Fortschritte deutlich erkennbar werden.
Kovalente und dative Bindungen zu Hauptgruppenmetallen, eine nützliche Unterscheidung
Authors: Haaland Arne
Published: June 2010

Lehrbücher der Anorganischen Chemie beschreiben die Bildung von Addukten als Koordination eines Elektronendonors an einen Elektronenacceptor, wobei als Beispiele oft die Amin‐Borane X3N → BY3 herangezogen werden. In den Lewis(Elektronenstrich)‐Formeln werden sowohl die dative Bindung (z. B. in H3N → BH3) als auch die kovalente Bindung (z. B. in H3CCH3) durch ein gemeinsames Elektronenpaar wiedergegeben. In den einfachen Molekülorbital‐ und Valence‐Bond‐Modellen wird in beiden Fällen die Wellenfunktion dieses Elektronenpaars auf die gleiche Weise aus geeigneten sp3‐hybridisierten Atomorbitalen der beteiligten Atome konstruiert. Der Unterschied zwischen kovalenter und dativer Bindung tritt erst in Erscheinung, wenn die Orbitalkoeffizienten genau analysiert werden. Dies mag der Grund sein, weshalb so viele Strukturchemiker nur sehr widerwillig zwischen diesen beiden Bindungstypen unterscheiden wollen. Ziel dieses Aufsatzes ist es, dem Leser in Erinnerung zu rufen, daß sich die physikochemischen Eigenschaften kovalenter und dativer Bindungen deutlich unterscheiden können – und sich oft auch tatsächlich unterscheiden‐, und zu zeigen, daß diese Betrachtungsweise eine gute Basis für das Verständnis der Strukturen einer Fülle von Hauptgruppenmetallverbindungen ist.
Di(4‐pyridinio)‐, Di(2‐benzothiazolio)‐, Di(2‐[1,3‐dithiolylio])‐ und Diformyl‐tetraaza[14]annulene sowie Tetraaza[14]annulenylen‐homologe Tetrathiafulvalene
Authors: Adams Florian , Gompper Rudolf
Published: June 2010

Ein Weg zu neuen Donoren für die Gewinnung organischer Metalle und Supraleiter könnte über die Titelverbindungen führen. Anders als beim vorstehenden Beitrag sind die kationischen Substituenten in 1 (siehe oben) über ein C‐Atom mit dem Ring verknüpft. Beim nebenstehenden Deprotonierungsprodukt mit X   S  CH  CH  S  handelt es sich um ein Homologes des „Parade‐Donors”︁ Tetrathiafulvalen.

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Platin‐Komplexe der Anionen Se2N und Se2N2H⊖; Röntgenstrukturanalyse von [Pt(Se2N2H)(PMe2Ph)2]Cl
Authors: Kelly Paul F. , Parkin Ivan P. , Slawin Alexandra M. Z. , Williams David J. , Woollins J. Derek
Published: June 2010

Einen Aufschwung der Se‐N‐Chemie könnte die Synthese von komplexstabilisierten Se‐N‐Verbindungen in flüssigem Ammoniak bewirken, bei der das Arbeiten mit isoliertem, sehr instabilem Se4N4 vermieden werden kann. Werden zur Reaktionslösung aus SeCl4 und flüssigem Ammoniak Komplexe wie 1 gegeben, kann man nach dem Erwärmen auf Raumtemperatur Se‐N‐Metallacyclen wie 2 isolieren, die beispielsweise mit HBF4 protoniert werden können. Die Röntgenstrukturanalyse des verwandten Komplexes 3 ergab im wesentlichen planare P2PtSe2N2‐Einheiten, die parallel und überlappend gestapelt sind.

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Sind Lithiosulfone konfigurativ stabil?
Authors: Gais Hans‐Joachim , Hellmann Gunther , Günther Harald , Lopez Fernando , Lindner Hans J. , Braun Sigmar
Published: June 2010

Die konfigurative Stabilität von Lithio(trifluormethyl)sulfonen wie 1 und 2 ist wesentlich höher als die der Analoga, die Ph statt CF3 enthalten. 1, das erste optisch aktive Lithiosulfon (Cα wahrscheinlich tetraedrisch koordiniert), ist bei tiefen Temperaturen optisch stabil. Die Synthese aus dem Sulfon und die Protonierung verlaufen unter Erhaltung der Konfiguration. [2 · TMEDA]2 (Cα planar koordiniert) hat eine sehr kurze Cα‐S‐Bindung.

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N‐Analoga von Metallacetylacetonaten: Bis(1,2,6,7‐tetracyan‐3,5‐diimino‐3,5‐dihydro‐pyrrolizinido)metall(II) (Metall = Fe, Ni, Cu, Zn); Kristallstruktur der Kupferverbindung
Authors: Bonamico Mario , Fares Vincenzo , Flamini Alberto , Imperatori Patrizia , Poli Nicola
Published: June 2010

Neue Komplexliganden sind in den Titelverbindungen 2 enthalten. Diese Verbindungen entstehen aus dem Anion 1, das in einer metallunterstützten Reaktion isomerisiert. An 2(M = Cu) wurde eine Röntgenstrukturanalyse durchgeführt. 2(M = Fe) kann leicht zum analogen Diaminopyrrolizidin‐FeII‐Komplex reduziert werden.

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Selektive 1:3‐Kupplung von Norbornen und Iodbenzol; einfache Synthese Cycloaliphaten‐anellierter Benzo[e]pyrene
Authors: Reiser Oliver , Weber Martin , de Meijere Armin
Published: June 2010

Pd(OAc)2/Bu4NBr/K2CO3 und Dimethylformamid, das sind die Reaktionsbedingungen, unter denen Norbornen selektiv mit drei Molekülen Iodbenzol zu dem Kohlenwasserstoff 1 mit einer an ein Norbornangerüst anellierten 4‐Phenyl‐9,10‐dihydrophenanthren‐Einheit reagiert. Photocyclisierung und zwei Dehydrierungen wandeln 1 in hoher Ausbeute in das Norbornen‐anellierte Benzo[e]pyren 2 um. Analoge Domino‐Heck‐Kupplungen wurden auch mit Deltacyclen, Inden und [2.2]Paracyclophan‐1,9‐dien beobachtet.

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Trigonal‐bipyramidale Lanthanoid‐Komplexe mit interstitiellem Sauerstoffatom
Authors: Schumann Herbert , Lee Pil Ryul , Loebel Jörg
Published: June 2010

Zwei axiale Natrium‐ und drei äquatoriale Lanthanoidatome um das interstitielle Sauerstoffatom kennzeichnen die trigonal‐bipyramidalen Lanthanoid‐Komplexe 1, die aus Lanthanoidtrichloriden und Dimethylpyrazolnatrium entstehen, wenn das Lösungsmittel Spuren von Wasser enthält.

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Hydrooligomerisierung von Alkinen – eine neue katalytische Reaktion mit [Co(py)6]⊕ als Promotor in Gegenwart von Wasserstoff
Authors: Biagini Paolo , Caporusso Anna M. , Funaioli Tiziana , Fachinetti Giuseppe
Published: June 2010

Pyridin‐unterstützte H2‐Addition an kationische Cobaltacyclen wie 1 dürfte die Ursache dafür sein, daß Alkine in Gegenwart von H2 und [Co(py)6]⊕ vorwiegend reduktiv oligomerisieren, während [Co(py)6]⊕ allein ihre Cyclotrimerisierung zu Arenen katalysiert. Aus 2‐Butin entstanden beispielsweise das konjugierte Dien 2, ein konjugiertes Trien und das Tetraen 3.

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Addition von Carbonsäureamiden an Alkinyltrifluormethylsulfone
Authors: Hanack Michael , Wilhelm Bärbl
Published: June 2010

„Push‐pull”︁‐Verbindungen 4 in guten Ausbeuten liefert die ungewöhnliche Addition von Carbonsäureamiden 2 an die äußerst reaktiven Alkinyltrifluormethylsulfone 1. Entscheidend für den Ablauf dieser Reaktion ist die Aktivierung der Dreifachbindung in 1 durch die F3CSO2‐Gruppe. Dimethylsulfoxid addiert sich ebenfalls spontan an 1. (R1 = Alkyl, Aryl; R2 = H, Me; R3 = Alkyl)

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Ein systematischer Zugang zu [M4(CO)12(μ4‐XY)]‐Clustern vom Schmetterlingstyp
Authors: Bantel Harald , Hansert Bernhard , Powell Anne K. , Tasi Miklos , Vahrenkamp Heinrich
Published: June 2010

Die photochemische Erzeugung von M(CO)3‐Fragmenten aus einfachen Carbonylkomplexen und ihre Addition an X = Y ‐verbrückte Dreikerncluster bietet einen allgemeinen Weg zu Vierkernclustern, die eine Schmetterlingsgerüststruktur haben, die im Detail von Art und Elektronenzahl des ungesättigten Liganden XY abhängt (siehe Bild). Durch eine derartige Clustervergrößerung sollte sich die Reaktivität der Liganden XY so verändern lassen, daß präparativ nützliche Umwandlungen möglich werden.

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[Mes2SbCu(PMe3)2]2, das erste Cu1‐Antimonid
Authors: Cowley Alan H. , Jones Richard A. , Nunn Christine M. , Westmoreland Donald L.
Published: June 2010

Ein planares Cu2Sb2‐Gerüst kennzeichnet die Struktur des Titelkomplexes 1, der unter Licht‐ und Luftausschluß im kristallinen Zustand mäßig stabil ist, sich in Lösung aber rasch zersetzt. Das CuI‐Antimonid wurde durch Lithiierung von Mes2SbH, dessen Struktur gleichfalls bestimmt wurde, erhielt man aus Mes3Sb durch Reduktion mit Li‐Pulver und Protonierung mit Me3NHCl.

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Energiedelle von Diradikalen; 4‐Methylen‐1,3‐cyclopentandiyl
Authors: Roth Wolfgang R. , Bauer Frank , Braun Karsten , Offerhaus Rolf
Published: June 2010

Bei der intramolekularen Rekombination von Diradikalen ist die Energiebarriere sehr stark von deren Struktur abhängig. Für das Titeldiradikal 2 konnte mit der Sauerstoffabfangreaktion eine Barriere von nur 2.4 kcal mol−1 bestimmt werden. Es ist das erste Mal, daß eine derart kleine Energiedelle kinetisch exakt gemessen wurde.

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Materials Science and Engineering in Britain
Authors: Chairman Colin Humphreys
Published: June 2010

Editorial Essay: The funding of the materials science research effort in British universities and polytechnics has recently been reorganized with the founding of the Materials Science and Engineering Commission of the SERC. The chairman of the committee assesses Britain's performance in materials science and outlines the aims and objectives of the funding bodies in the UK.
Siloxane Copolymers with Laterally and Terminally Attached Mesogenic Side Chains
Authors: Gray G. W. , Hill J. S. , Lacey D.
Published: June 2010

Communication: Liquid crystals based on polysiloxane copolymers (see figure) with well defined physical characteristics have been synthesized by varying the type and ratio of the laterally attached mesogenic side chains. Applications in integrated optics and optical storage are envisaged.

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Ground‐penetrating radar imaging of twelfth century Romanesque foundations beneath the thirteenth century Gothic abbey church of Valmagne, France
Authors: Udphuay Suwimon , Paul Vivian L. , Everett Mark E. , Warden Robert B.
Published: June 2010

Ground‐penetrating radar surveys with closely spaced profiles using 500‐ and 800‐MHz antennae were performed on the fine gravel floor of the Gothic abbey church of Valmagne, near Montpellier, in south‐central France. The accessible floor area of the choir, transept and nave was surveyed to locate and preliminarily interpret the remains of the twelfth century Romanesque building beneath the existing building. Processed two‐dimensional ground‐penetrating radar profiles and constructed time‐slice images show distinct reflection events associated with the twelfth century foundations. The GPR technique is calibrated against a known buried limestone pier belonging to the earlier Romanesque construction. It proved challenging to differentiate the remains of the twelfth century building from the existing building and the host geology because the dielectric contrasts between them is low. Preliminary interpretation of the results suggest that the Romanesque pier abuts and continues under a thirteenth century pier at the intersection of the ambulatory and transept of the existing church. In addition, the twelfth century building appears to have had a rectangular sanctuary flanked by chapels of unequal width opening off a transept comparable in width and length with the existing transept and a nave comparable in length with the existing nave. The results of this study are significant to medieval architectural history since they reveal new subsurface constraints on the nature of Cistercian construction in Languedoc. Copyright © 2010 John Wiley & Sons, Ltd.
Logic Information Communication in a Fluorescent Molecular Switch
Authors: Bai Yan‐Chun , Zhang Chao , Fang Chen‐Jie , Yan Chun‐Hua
Published: June 2010

Based on the chemical‐sensitive fluorescence emission behaviors of the molecular switch 4‐bromo‐5‐methoxy‐2‐(2‐pyridyl)thiazole (2‐BMPT), the communication of logic information between two functional units has been realized. With the rational control of the protonation and coordination reaction of 2‐BMPT, an upstream switching unit (a 1:2 demultiplexer) and two downstream data‐processing units are involved and interconnected in the communication. The two output states of the 1:2 demultiplexer serve as the initial input states of the two parallel downstream data‐processing units, which execute the information communication between the two circuit layers. Furthermore, in the parallel data‐processing layer, the logic gates of INHIBIT and YES accomplish their specific logic functions. Therefore, a molecular cascade circuit composed of an upstream switch and two downstream processing units has been constructed based on the chemical‐modulated fluorescence properties of 2‐BMPT.
Zur Konstitution der Triaza‐indolizine
Authors: Birr Emil‐Joachim , Walther Werner
Published: June 2010

Durch Synthese der Triaza‐indolizine über die Hydrazinopyrimidine wird gezeigt, daß bei der Kondensation von 3‐Amino‐1.2.4‐triazol mit Verbindungen, die in β‐Stellung zwei reaktionsfähige Gruppen enthalten. 2.3.4‐Triaza‐indolizine entstehen.
Über Reduktionen mit Lithiumaluminiumhydrid, V. Mitteil.: Zur Darstellung des Vitamins B1
Authors: Dornow Alfred , Petsch Günther
Published: June 2010

Es wird eine Vereinfachung der Thiamin‐Synthese durch Anwendung der Umlagerung nach Willgerodt und des Lithiumaluminiumhydrids beschrieben.
Über zwei neue Alkaloide aus Duboisia leichhardtii
Authors: Deckers Werner , Maier Josef
Published: June 2010

Aus Duboisia leichhardtii wurde ein bisher nicht beschriebenes Hydrobromid isoliert. Es wurde festgestellt, daß es sich um das Hydrobromid einer Mischung von 1.25 Tln. Isobutyryl‐tropein mit einem Tl. d‐α‐Methylbutyryl‐tropein handelt.
Synthese des 1.5‐Dimethyl‐azulens
Authors: Arnold Herbert , Schachtner Hannelore
Published: June 2010

Die Umsetzung von 1.5‐Dimethyl‐indan mit Diazoessigester führt ohne gleichzeitige Bildung von Isomeren zum 1.5‐Dimethyl‐azulen, dessen Konstitution durch Vergleich mit einem auf anderem Wege hergestellten Präparat gesichert ist.
Über den Ringschluß von Aryl‐thioglykolsäuren zu 3‐Oxy‐thionaphthenen in Fluorwasserstoff (Mehrkernige Thiophene, I. Mitteil.)
Authors: Dann Otto , Kokoradz Michael
Published: June 2010

Es wird die Umsetzung einiger Aryl‐thioglykolsäuren in technischer, wasserfreier Flußsäure zu Oxy‐thionaphthenen beschrieben und der Einfluß der Reaktionsbedingungen studiert.
Über Bildung und Darstellung von d‐Glucosamin aus Fructose und Ammoniak
Authors: Heyns Kurt , Meinecke Karl‐Heinz
Published: June 2010

Bei der Umsetzung von Fructose mit wäßrigem Ammoniak sowie insbesondere auch mit wasserfreiem flüssigen Ammoniak entsteht d‐ Glucosamin. Die Identifizierung erfolgte durch das analytische und chromatographische Verhalten sowie durch Darstellung des nach Kupplung mit Phenylisocyanat und Ringschluß mit Essigsäure erhaltenen 1‐Phenyl‐4‐[d‐arabo‐tetraoxybutyl]‐imidazolons‐(2) und durch Überführung in die N‐Carbobenzoxy‐Verbindung. Die biochemischen Zusammenhänge der Hexosamin‐Bildung werden erörtert.
1.2‐Dianilino‐äthan als Aldehydreagens
Authors: Wanzlick Hans‐Werner , Löchel Wolfgang
Published: June 2010

1.2‐Dianilino‐äthan reagiert in schwach saurem Medium mit Aldehyden unter Abscheidung gut kristallisierter Tetrahydro‐imidazole. Die Derivate eignen sich zur Charakterisierung und Abtrennung von Aldehyden. Hydrolytische Spaltung liefert praktisch quantitativ den Aldehyd zurück.
Eine Verbesserung der Bestimmung von Aminosäuren am Carboxylende von Peptiden durch Reduktion der Carboxylgruppe
Authors: Graßmann W. , Hörmann H. , Endres H.
Published: June 2010

Die endständigen Carboxylgruppen von Peptiden werden verestert und mit Lithiumborhydrid reduziert. Die nach Hydrolyse erhaltenen Aminosäuren und Aminoalkohole werden in die entsprechenden Dinitrophenyl‐Verbindungen übergeführt. Die Dinitrophenyl‐aminoalkohole können dann als Neutralkörper von den Dinitrophenyl‐aminosäuren praktisch quantitativ abgetrennt und papierchromatographisch identifiziert werden.
Zur Darstellung von Oxymethylphenolen durch hydrierende Dehalogenierung kernhalogenierter Oxymethylphenole
Authors: Kämmerer Hermann , Grossmann Max
Published: June 2010

Es wird die Darstellung von Oxymethylphenolen, als “Phenolalkohole” bekannt, durch hydrierende Dehalogenierung entsprechender kernhalogenierter Oxymethylphenole beschrieben. Die Dimethylenäthergruppe in 1.1′‐Dioxy‐dibenzyläther bleibt bei dem beschriebenen Hydrierverfahren mindestens in einem Ausmaß von 60–80% ungespalten.
Reaktionen mit Nitrosodisulfonat, III. Mitteil.: Equilenin‐chinon
Authors: Teuber Hans‐Joachim
Published: June 2010

Equilenin wird durch Kalium‐nitrosodisulfonat zur Verbindung C18H16O3 oxydiert, die die Teilstruktur des β‐Naphthochinons besitzt und durch Schweflige Säure zum entsprechenden Hydrochinon reduziert wird. Wasserstoffperoxyd öffnet den Chinonring, wobei die Lactonsäure C18H18O6 entsteht, die noch einen Benzolring enthält.
Äquivalent‐ und Molekulargewichts‐Bestimmungen durch potentiometrische Mikrotitration in nichtwäßrigen Lösungsmitteln
Authors: Brockmann Hans , Meyer Ernst
Published: June 2010

Die potentiometrische Titration schwacher Säuren in nichtwäßrigen Lösungsmitteln wurde zu einer Mikromethode entwickelt und als Differentialtitration zur Äquivalent‐ und Molekulargewichts‐Bestimmung neuer Naturstoffe verwendet.
Die Kondensation von Sulfimidsalzen mit basisch substituierten Alkylhalogeniden
Authors: Runge Franz , Engelbrecht Heinz‐Joachim , Preusser Gerhard
Published: June 2010

Bei der Kondensation der Alkalisalze von Sulfimiden mit β‐Aminoalkylhalogeniden können 3 Reaktionsprodukte entstehen, deren Konstitution aufgeklärt wird.
Online education in community colleges
Authors: Cejda Brent
Published: June 2010

This chapter explores the tremendous growth in the use of the Internet to deliver distance education at community colleges. The author examines various definitions of online education, including the types of courses, programs, and degrees available and the types of community colleges that offer greater amounts of online programming. Considerations for the future growth of online education are provided.
Online student services at the community college
Authors: Hornak Anne M. , Akweks Kayeri , Jeffs Madeline
Published: June 2010

The authors explore the processes involved in moving to online student services at community colleges, relate success stories, and address the challenges involved.
Approaching common ground: Defining quality in online education
Authors: Mitchell Regina L. Garza
Published: June 2010

This chapter discusses the notion of quality in online education and attempts to find some commonality among the numerous existing definitions.
Optical Detection and Manipulation of Single Molecules in Room‐Temperature Solutions
Authors: Chiu Daniel T. , Zare Richard N.
Published: June 2010

With the tight focus of a gaussian laser beam, single molecules in solution at room temperature can be trapped and detected by observation of fluorescent photons. The focus defines an ultrasmall probe volume on the order of 1 femtoliter, and the electric field gradient associated with this focus enables an individual molecule to be trapped and manipulated.