bluuebunny/crossref_metadata_2025 huggingface dataset:
Typology of Slovenia’s Alpine Region with Emphasis on Land Use and Changes in Land Use
Authors: Petek Franci
Published: January 2009

The article presents the elaboration and contents of the typology of Slovenia’s alpine region. The smallest spatial unit of the study is the cadastral municipality (total 150), for which I assembled numerous data on land use and changes in land use, surface elements, and sociogeographical factors. To illustrate regional differences in landscape elements, I first divided Slovenia’s alpine region into six mezzo-regions. In establishing land use and land use changes, and their correlation with surface elements and sociogeographical characteristics, I determined that the cadastral municipalities within each of the defined mezzo-regions do not necessarily have similar properties but may rather have similar properties with neighbouring cadastral municipalities in other mezzo-regions. This knowledge and numerous data layers were the basis for the elaboration of a synthetical typology of Slovenia’s alpine region. With the help of the hierarchical method of classification into groups and factor analyses, seven types (groups) of cadastral municipalities of the alpine region appeared whose borders did not match with the defined mezzo-regions.
Quantum‐Chemical Characterization of the Origin of Dipole Formation at Molecular Organic/Organic Interfaces
Authors: Avilov Igor , Geskin Victor , Cornil Jérôme
Published: January 2009

Recent experiments have reported a vacuum level shift at the interface between organic materials due to the formation of an interface dipole layer. On the basis of quantum‐chemical calculations, this paper sheds light on the factors contributing to the formation of an interface dipole between an electron donor and an electron acceptor, considering as model system a complex made of tetrathiafulvalene (TTF) as a donor and tetracyanoquinodimethane (TCNQ) as an acceptor. The results indicate that the interface dipole is governed both by charge‐transfer and polarization effects and allow for disentangling of their respective contributions. Two regimes of charge transfer can be distinguished depending on the strength of the electronic coupling: a fractional charge transfer occurs in the strong coupling regime while only integer charges are transferred when the coupling is weak. The polarization contribution can be significant, even in the presence of a pronounced charge transfer between the donor and acceptor molecules. The values of ionization potential and electron affinity of the donor and acceptor molecules may experience shifts as large as several tenths of an eV at the interface with respect to the isolated compounds.
Enhancement of Carrier Mobilities of Organic Semiconductors on Sol–Gel Dielectrics: Investigations of Molecular Organization and Interfacial Chemistry Effects
Authors: Cahyadi Tommy , Kasim Johnson , Tan Huei Shuan , Kulkarni Shripad R. , Ong Beng S. , Wu Yiliang , Chen Zhi‐Kuan , Ng Chee Mang , Shen Ze‐Xiang , Mhaisalkar Subodh G.
Published: January 2009

The dielectric‐semiconductor interfacial interactions critically influence the morphology and molecular ordering of the organic semiconductor molecules, and hence have a profound influence on mobility, threshold voltage, and other vital device characteristics of organic field‐effect transistors. In this study, p‐channel small molecule/polymer (evaporated pentacene and spin‐coated poly(3,3‴;‐didodecylquarterthiophene) – PQT) and n‐channel fullerene derivative ({6}‐1‐(3‐(2‐thienylethoxycarbonyl)‐propyl)‐{5}‐1‐phenyl‐[5,6]‐C61 – TEPP‐C61) show a significant enhancement in device mobilities ranging from ∼6 to ∼45 times higher for all classes of semiconductors deposited on sol–gel silica gate‐dielectric than on pristine/octyltrichlorosilane (OTS)‐treated thermally grown silica. Atomic force microscopy, synchrotron X‐ray diffraction, photoluminescence/absorption, and Raman spectroscopy studies provide comprehensive evidences that sol–gel silica dielectrics‐induced enhancement in both p‐ and n‐channel organic semiconductors is attributable to better molecular ordering/packing, and hence reduced charge trapping centers due to lesser structural defects at the dielectric‐semiconductor interface.
Highly Efficient Quantum‐Dot‐Sensitized Solar Cell Based on Co‐Sensitization of CdS/CdSe
Authors: Lee Yuh‐Lang , Lo Yi‐Siou
Published: January 2009

Cadmium sulfide (CdS) and cadmium selenide (CdSe) quantum dots (QDs) are sequentially assembled onto a nanocrystalline TiO2 film to prepare a CdS/CdSe co‐sensitized photoelectrode for QD‐sensitized solar cell application. The results show that CdS and CdSe QDs have a complementary effect in the light harvest and the performance of a QDs co‐sensitized solar cell is strongly dependent on the order of CdS and CdSe respected to the TiO2. In the cascade structure of TiO2/CdS/CdSe electrode, the re‐organization of energy levels between CdS and CdSe forms a stepwise structure of band‐edge levels which is advantageous to the electron injection and hole‐recovery of CdS and CdSe QDs. An energy conversion efficiency of 4.22% is achieved using a TiO2/CdS/CdSe/ZnS electrode, under the illumination of one sun (AM1.5,100 mW cm−2). This efficiency is relatively higher than other QD‐sensitized solar cells previously reported in the literature.
Heat‐Transport Mechanisms in Superlattices
Authors: Koh Yee Kan , Cao Yu , Cahill David G. , Jena Debdeep
Published: January 2009

The heat transport mechanisms in superlattices are identified from the cross‐plane thermal conductivity Λ of (AlN)x–(GaN)y superlattices measured by time‐domain thermoreflectance. For (AlN)4.1 nm–(GaN)55 nm superlattices grown under different conditions, Λ varies by a factor of two; this is attributed to differences in the roughness of the AlN/GaN interfaces. Under the growth condition that gives the lowest Λ, Λ of (AlN)4 nm–(GaN)y superlattices decreases monotonically as y decreases, Λ = 6.35 W m−1 K−1 at y = 2.2 nm, 35 times smaller than Λ of bulk GaN. For long‐period superlattices (y > 40 nm), the mean thermal conductance G of AlN/GaN interfaces is independent of y, G ≈ 620 MW m−2 K−1. For y < 40 nm, the apparent value of G increases with decreasing y, reaching G ≈ 2 GW m−2 K−1 at y < 3 nm. MeV ion bombardment is used to help determine which phonons are responsible for heat transport in short period superlattices. The thermal conductivity of an (AlN)4.1 nm–(GaN)4.9 nm superlattice irradiated by 2.3 MeV Ar ions to a dose of 2 × 1014 ions cm−2 is reduced by <35%, suggesting that heat transport in these short‐period superlattices is dominated by long‐wavelength acoustic phonons. Calculations using a Debye‐Callaway model and the assumption of a boundary scattering rate that varies with phonon‐wavelength successfully capture the temperature, period, and ion‐dose dependence of Λ.
Ambipolar Organic Field‐Effect Transistors from Cross‐Conjugated Aromatic Quaterthiophenes; Comparisons with Quinoidal Parent Materials
Authors: Ortiz Rocío Ponce , Facchetti Antonio , Marks Tobin J. , Casado Juan , Zgierski Marek Z. , Kozaki Masatoshi , Hernández Víctor , Navarrete Juan T. López
Published: January 2009

This contribution presents an electrochemical, Raman spectroscopic, and theoretical study probing the differences in molecular and electronic structure of two quinoidal oligothiophenes (3′,4′‐dibutyl‐5,5″‐bis(dicyanomethylene)‐5,5″‐dihydro‐2,2′:5′,2″‐terthiophene and 5,5′‐bis(dicyanomethylene)‐3‐hexyl‐2,5‐dihydro‐4,4′‐dihexyl‐2,2′,5,5′‐tetrahydro‐tetrathiophene) with terminal tetracyanomethylene functionalization and aromatic oligothiophenes where acceptor moieties are positioned at lateral positions along the conjugated chain (6,6′‐dibutylsulfanyl‐[2,2′‐bi‐[4‐dicyanovinylene‐4H‐cyclopenta[2,1‐b:3,4‐b′]dithiophene]). In this way, the consequences of linear and cross conjugation are compared and contrasted. From this analysis, it is apparent that organic field‐effect transistors fabricated with cross‐conjugated tetrathiophene semiconductors should combine the benefits of an electron‐donor aromatic chain with strongly electron‐accepting tetracyanomethylene substituents. The corresponding organic field‐effect transistors exhibit ambipolar transport with rather similar hole and electron mobilities. Moreover, n‐channel conduction is enhanced to yield one of the highest electron mobilities found to date for this type of material.
Influence of Point‐Defect Reaction Kinetics on the Lattice Parameter of Ce0.8Gd0.2O1.9
Authors: Kossoy Anna , Feldman Yishai , Korobko Roman , Wachtel Ellen , Lubomirsky Igor , Maier Joachim
Published: January 2009

The kinetics of point‐defect association/dissociation reactions in Ce0.8Gd0.2O1.9 and their influence on the crystal lattice parameter are investigated by monitoring thermally induced stress and strain in substrate‐ and self‐supported thin films. It is found that, in the temperature range of 100–180 °C, the lattice parameter of the substrate‐supported films and the lateral dimensions of annealed, self‐supported films both exhibit a hysteretic behavior consistent with dissociation/association of oxygen vacancy–aliovalent dopant complexes. This leads to strong deviation from linear elastic behavior, denoted in the authors' previous work as the “chemical strain” effect. At room temperature, the equilibrium state of the point defects is reached within a few months. During this period, the lattice parameter of the substrate‐supported films spontaneously increases, while the self‐supported films are observed to transform from the flat to the buckled state, indicating that formation of the dopant–vacancy complex is associated with a volume increase. The unexpectedly slow kinetics of establishing the defect equilibrium at room temperature can explain the fact that, depending on the sample history, the “observable” lattice parameters of Ce0.8Gd0.2O1.9, as reported in the literature, may differ from one another by a few tenths of a percent. These findings strongly suggest that the lattice parameter of the materials with a large concentration of interacting point defects is a strong function of time and material preparation route.
Field Emission and Cathodoluminescence of ZnS Hexagonal Pyramids of Zinc Blende Structured Single Crystals
Authors: Chen Zhi‐Gang , Zou Jin , Wang Dai‐Wei , Yin Li‐Chang , Liu Gang , Liu Qingfeng , Sun Cheng‐Hua , Yao Xiangdong , Li Feng , Yuan Xiao‐Li , Sekiguchi Takashi , Lu Gao Qing , Cheng Hui‐Ming
Published: January 2009

Single‐crystal hexagonal pyramids of zinc blende ZnS are fabricated by facile thermal evaporation in an ammonia atmosphere at 1150 °C. It is found that ZnS pyramids grow along the [111] crystal axis and possess a sharp tip with a diameter of ∼10 nm and a micrometer‐sized base. The structural model and growth mechanism are proposed based on crystallographic characteristics. This unique ZnS pyramid structure exhibits a low turn‐on field (2.81 V µm−1), a high field‐enhancement factor (over 3000), a large field‐emission current density (20 mA cm−2), and good stability with very small fluctuation (0.9%). These superior field‐emission properties are clearly attributed to the pyramid morphology, with micrometer‐sized bases and nanotips, and high crystallinity. Moreover, a stable UV emission of 337 nm at room temperature is observed and can be ascribed to the band emission of the zinc blende phase. These results suggest that the ZnS hexagonal pyramids can be expected to find promising applications as field emitters and optoelectronic devices.
Multifunctional Deep‐Blue Emitter Comprising an Anthracene Core and Terminal Triphenylphosphine Oxide Groups
Authors: Chien Chen‐Han , Chen Ching‐Kun , Hsu Fang‐Ming , Shu Ching‐Fong , Chou Pi‐Tai , Lai Chin‐Hung
Published: January 2009

A highly efficient blue‐light emitter, 2‐tert‐butyl‐9,10‐bis[4′‐(diphenyl‐phosphoryl)phenyl]anthracene (POAn) is synthesized, and comprises electron‐deficient triphenylphosphine oxide side groups appended to the 9‐ and 10‐positions of a 2‐tert‐butylanthracene core. This sophisticated anthracene compound possesses a non‐coplanar configuration that results in a decreased tendency to crystallize and weaker intermolecular interactions in the solid state, leading to its pronounced morphological stability and high quantum efficiency. In addition to serving as an electron‐transporting blue‐light‐emitting material, POAn also facilitates electron injection from the Al cathode to itself. Consequently, simple double‐layer devices incorporating POAn as the emitting, electron‐transporting, and ‐injecting material produce bright deep‐blue lights having Commission Internationale de L'Eclairage coordinates of (0.15,0.07). The peak electroluminescence performance was 4.3% (2.9 cd A−1). For a device lacking an electron‐transport layer or alkali fluoride, this device displays the best performance of any such the deep‐blue organic light‐emitting diodes reported to date.
Temperature‐Sensitive Nanocapsules for Controlled Drug Release Caused by Magnetically Triggered Structural Disruption
Authors: Liu Ting‐Yu , Liu Kun‐Ho , Liu Dean‐Mo , Chen San‐Yuan , Chen I‐Wei
Published: January 2009

Self‐assembled nanocapsules containing a hydrophilic core and a crosslinked yet thermosensitive shell are successfully prepared using poly(ethylene‐oxide)‐poly(propylene‐oxide)‐poly(ethylene‐oxide) block copolymers, 4‐nitrophenyl chloroformate, gelatin, and 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide. The core is further rendered magnetic by incorporating iron oxide nanoparticles via internal precipitation to enable externally controlled actuation under magnetic induction. The spherical nanocapsules exhibit a hydrophilic‐to‐hydrophobic transition at a characteristic but tunable temperature reaching 40 °C, triggering a size contraction and shrinkage of the core. The core content experiences very little leakage at 25 °C, has a half life about 5 h at 45 °C, but bursts out within a few minutes under magnetic heating due to iron oxide coarsening and core/shell disruption. Such burst‐like response may be utilized for controlled drug release as illustrated here using a model drug Vitamin B12.
Highly Efficient Red Phosphorescent OLEDs based on Non‐Conjugated Silicon‐Cored Spirobifluorene Derivative Doped with Ir‐Complexes
Authors: Lyu Yi‐Yeol , Kwak Jeonghun , Jeon Woo Sung , Byun Younghun , Lee Hyo Sug , Kim Doseok , Lee Changhee , Char Kookheon
Published: January 2009

A novel host material containing silicon‐cored spirobifluorene derivative (SBP‐TS‐PSB), is designed, synthesized, and characterized for red phosphorescent organic light‐emitting diodes (OLEDs). The SBP‐TS‐PSB has excellent thermal and morphological stabilities and exhibits high electroluminescence (EL) efficiency as a host for the red phosphorescent OLEDs. The electrophosphorescence properties of the devices using SBP‐TS‐PSB as the host and red phosphorescent iridium (III) complexes as the emitter are investigated and these devices exhibit higher EL performances compared with the reference devices with 4,4′‐N,N′‐dicarbazole‐biphenyl (CBP) as a host material; for example, a (piq)2Ir(acac)‐doped SBP‐TS‐PSB device shows maximum external quantum efficiency of ηext = 14.6%, power efficiency of 10.3 lm W−1 and Commission International de L'Eclairage color coordinates (0.68, 0.32) at J = 1.5 mA cm−2, while the device with the CBP host shows maximum ηext = 12.1%. These high performances can be mainly explained by efficient triplet energy transfer from the host to the guests and improved charge balance attributable to the bipolar characteristics of the spirobifluorene group.
Ordered Mesoporous In2O3: Synthesis by Structure Replication and Application as a Methane Gas Sensor
Authors: Waitz Thomas , Wagner Thorsten , Sauerwald Tilman , Kohl Claus‐Dieter , Tiemann Michael
Published: January 2009

The synthesis and characterization of ordered mesoporous In2O3 materials by structure replication from hexagonal mesoporous SBA‐15 silica and cubic KIT‐6 silica is presented. Variation of the synthesis parameters allows for different pore sizes and pore wall thicknesses in the products. The In2O3 samples turn out to be stable up to temperatures between 450 °C and 650 °C; such high thermal stability is necessary for their application as gas sensors. Test measurements show a high sensitivity to methane gas in concentrations relevant for explosion prevention. The sensitivity is shown to be correlated not only with the surface‐to‐volume ratio, but also with the nanoscopic structural properties of the materials.
High‐Performance SOFC Cathodes Prepared by Infiltration
Authors: Vohs John M. , Gorte Raymond J.
Published: January 2009

Improved cathodes are required for low‐temperature operation of solid‐oxide fuel cells (SOFCs). Recent work has shown that electrode fabrication and modification by infiltration of active components into a porous scaffold can result in outstanding electrochemical performance. In this paper we review the literature on this new approach for cathode preparation and discuss the insights that this work has provided for understanding the relationships between the materials properties, electrochemical performance, and electrode stability.
Retraction: An Efficient Synthesis of Poly(ethylene glycol)‐Supported Iron(II) Porphyrin using a Click Reaction and its Application for the Catalytic Olefination of Aldehydes
Authors: Jain Suman L. , Joseph Jomy K. , Kühn Fritz E. , Reiser Oliver
Published: January 2009

The first successful synthesis of poly(ethylene glycol) (PEG) immobilized iron(II) porphyrin using a copper‐catalyzed azide‐alkyne [3+2] cycloaddition is reported. In contrast to the existing methods for the synthesis of PEG‐immobilized metalloporphyrins, the click method offers better catalyst loading under comparatively mild reaction conditions. The prepared complex 5 (PEG‐C51H39FeN7O) was found to be an efficient catalyst for the selective olefination of aldehydes with ethyl diazoacetate in the presence of triphenylphosphine and afforded excellent olefin yields with high (E) selectivities. The PEG‐supported catalyst 5 was readily recovered by precipitation and filtration and was recycled for up to ten runs without significant loss of activity.
The First Thiadiazolidine 1‐Oxide System for Phosphine‐Free Palladium‐Mediated Catalysis
Authors: Buckley Benjamin R. , Neary Stephen P.
Published: January 2009

We herein report a highly active catalyst system using for the first time a thiadiazolidine 1‐oxide as a ligand for palladium in the Mizoroki–Heck reaction. Excellent yields of stilbenes derived from aryl iodides and bromides have been achieved using as little as 0.00002 mol% catalyst. The ligand/palladium system can be stored as a stock solution open to air at room temperature with no observable loss of activity for a period of several weeks/months.
Selective Oxidation of Aromatic Amines to Nitro Derivatives using Potassium Iodide‐tert‐Butyl Hydroperoxide Catalytic System
Authors: Reddy K. Rajender , Maheswari C. Uma , Venkateshwar M. , Kantam M. Lakshmi
Published: January 2009

The direct oxidation of aromatic primary amines to the corresponding nitro compounds selectively in 47–98% yields has been achieved by using potassium iodide as catalyst and tert‐butyl hydroperoxide as the external oxidant. The present catalytic system works well for both electron‐rich and electron‐poor substrates.
Kinetic Resolutions by Enantioselective Pauson–Khand‐Type Reaction
Authors: Kim Dong Eun , Kwak Jaesung , Kim In Su , Jeong Nakcheol
Published: January 2009

A kinetic resolution of 1‐arylallyl propargyl ethers by enantioselective Pauson–Khand‐type reaction catalysts was successfully carried out. While cationic rhodium(I) with a BINAP‐based ligand having an electron‐deficient phosphine is the choice for the slow reacting substrates, neutral iridium(I) with a BINAP‐based ligand possessing an electron‐rich phosphine provided excellent results for the more reactive substrates.
Lewis Acid‐Mediated Selective Cycloadditions of Vinylidenecyclopropanes with Aromatic Aldehydes: An Efficient Protocol for the Synthesis of Benzo[c]fluorene, Furan and Furo[2,3‐b]furan Derivatives
Authors: Su Chenliang , Huang Xian
Published: January 2009

Three kinds of Lewis acid‐mediated reactions of vinylidenecyclopropanes and aromatic aldehydes are disclosed in this paper, providing an efficient and selective synthesis of a variety of functionalized benzo[c]fluorene, furan and furo[2,3‐b]furan derivatives.
Water in Stereoselective Organocatalytic Reactions
Authors: Gruttadauria Michelangelo , Giacalone Francesco , Noto Renato
Published: January 2009

In this review, recent advances in asymmetric organocatalytic reactions carried out with variable amounts of water, from substoichiometric to a large excess (reaction medium), are discussed. We also summarize several proposed mechanisms for the different possibilities of the action of water both in the increased activity of the catalyst and in the asymmetric induction. Finally, the application of this catalytic methodology to the enantioselective synthesis of valuable compounds through enamine or iminium catalysis is presented.
Process intensification aspects for steam methane reforming: An overview
Authors: Bhat Shrikant A. , Sadhukhan Jhuma
Published: January 2009

Steam methane reforming (SMR) is the most widely used process in industry for the production of hydrogen, which is considered as the future generation energy carrier. Having been perceived as an important source of H2, there are abundant incentives for design and development of SMR processes mainly through the consideration of process intensification and multiscale modeling; two areas which are considered as the main focus of the future generation chemical engineering to meet the global energy challenges. This article presents a comprehensive overview of the process integration aspects for SMR, especially the potential for multiscale modeling in this area. The intensification for SMR is achieved by coupling with adsorption and membrane separation technologies, etc., and using the concept of multifunctional reactors and catalysts to overcome the mass transfer, heat transfer, and thermodynamic limitations. In this article, the focus of existing and future research on these emerging areas has been drawn. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Genetic heterogeneity in two consanguineous families segregating early onset retinal degeneration: The pitfalls of homozygosity mapping
Authors: Benayoun Liat , Spiegel Ronen , Auslender Noa , Abbasi Anan H , Rizel Leah , Hujeirat Yasir , Salama Ihsan , Garzozi Hanna J. , Allon‐Shalev Stavit , Ben‐Yosef Tamar
Published: January 2009

Retinitis pigmentosa is the most common form of hereditary retinal degeneration, with a worldwide prevalence of 1 in 4,000. At least 28 genes and loci have been implicated in nonsyndromic autosomal recessive retinitis pigmentosa. Here we report two extended and highly consanguineous families segregating early onset retinitis pigmentosa. Despite the consanguinity in both families, we found allelic heterogeneity in one of them, in which affected individuals were compound heterozygotes for two different mutations of the CRB1 gene. In the second family we found evidence for locus heterogeneity. A novel homozygous mutation of RDH12 was found in only 14 of 17 affected individuals in this family. Our data indicate that in the other affected individuals the disease is caused by a different gene/s. These findings demonstrate that while homozygosity mapping is an efficient tool for identification of the underlying mutated genes in inbred families, both locus and allelic heterogeneity may occur even within the same consanguineous family. These observations should be taken into account, especially when studying common and heterogeneous recessive genetic conditions. © 2009 Wiley‐Liss, Inc.
Economic intensification and degenerative joint disease: Life and labor on the postcontact north coast of Peru
Authors: Klaus Haagen D. , Spencer Larsen Clark , Tam Manuel E.
Published: January 2009

This study tests the hypothesis that the colonial economy of the Lambayeque region of northern coastal Peru was associated with a mechanically strenuous lifestyle among the indigenous Mochica population. To test the hypothesis, we documented the changes in the prevalence of degenerative joint disease (or DJD) in human remains from the late pre‐Hispanic and colonial Lambayeque Valley Complex. Comparisons were made using multivariate odds ratios calculated across four age classes and 11 principle joint systems corresponding to 113 late pre‐Hispanic and 139 postcontact adult Mochica individuals. Statistically significant patterns of elevated postcontact DJD prevalence are observed in the joint systems of the shoulder, elbow, wrist, and knee. More finely grained comparison between temporal phases indicates that increases in prevalence were focused immediately following contact in the Early/Middle Colonial period. Analysis of DJD by sex indicates postcontact males experienced greater DJD prevalence than females. Also, trends between pre‐ and postcontact females indicate nearly universally elevated DJD prevalence among native colonial women. Inferred altered behavioral uses of the upper body and knee are contextualized within ecological, ethnohistoric, and ethnoarchaeological frameworks and appear highly consistent with descriptions of the local postcontact economy. These patterns of DJD appear to stem from a synergism of broad, hemispheric level sociopolitical alterations, specific changes to Mochica activity and behavior, regional economic intensification, and local microenvironmental characteristics, which were all focused into these biological outcomes by the operation of a colonial Spanish political economy on the north coast of Peru from A.D. 1536 to 1751. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.
The effect of sex on risk of mortality during the Black Death in London, A.D. 1349–1350
Authors: DeWitte Sharon N.
Published: January 2009

The Black Death of 1347–1351 was one of the most devastating epidemics in human history, and though it is frequently assumed that the epidemic killed indiscriminately, recent research suggests that the disease was selective, at least with respect to frailty. The purpose of this study is to determine whether the Black Death was similarly selective with respect to biological sex—that is, did either sex face an elevated risk during the epidemic or were men and women at equal risk of dying? A sample of 298 victims of the Black Death, from the East Smithfield cemetery in London, is compared to a pre‐Black Death normal mortality sample of 194 individuals from two Danish urban cemeteries, St Mikkel Church (Viborg) and St Albani Church (Odense). To assess the effect of sex on risk of death, sex is modeled as a covariate affecting the Gompertz–Makeham model of adult mortality. The results suggest that sex did not strongly affect risk of death in either the normal mortality or Black Death samples. These results are important for improving our understanding of Black Death mortality patterns. This is essential for understanding the effects the Black Death had on European populations, and the methods used here can potentially be informatively applied to investigations of other episodes of epidemic diseases in past populations. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc.
Further analysis of the population history of ancient Egyptians
Authors: Schillaci Michael A. , Irish Joel D. , Wood Carolan C.E.
Published: January 2009

The origins of state formation in ancient Egypt have been the focus of recent research utilizing biological data to test hypotheses regarding in situ development of local groups, or large‐scale in‐migration, possibly by an invading army. The primary goal of the present research is to further test these hypotheses. Our secondary goal is to compare different distance measures and assess how they might affect interpretation of population history. We analyze craniodental nonmetric data using several different measures of biological distance, as well as a method for estimating group diversity using multidimensional scaling of distance estimates. Patterns of biological variation and population relationships were interpreted in temporal and geographic contexts. The results of our analyses suggest that the formation of the ancient Egyptian state likely included a substantial in situ process, with some level of contribution by outside migrants probable. The higher level of population structure in Lower Egypt, relative to Upper Egypt, suggests that such influence and migration by outsiders may not have been widespread geographically. These findings support, but serve to refine further those obtained by the second author in a previous study. Moreover, our comparison of distance measures indicates that the choice of measure can influence identification and interpretation of the microevolutionary processes shaping population history, despite being strongly correlated with one another. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc.
Measuring and interpreting age‐related loss of vertebral bone mineral density in a medieval population
Authors: Agarwal Sabrina C. , Grynpas Marc D.
Published: January 2009

This study investigates the age‐ and sex‐related patterns in vertebral bone mineral density (BMD) and the relationship between BMD and vertebral osteophytosis (VO), using a specialized peripheral densitometer in a skeletal sample excavated from the British medieval village Wharram Percy. A total of 58 individuals were divided by sex into three broad age categories (18–29, 30–49, 50+ years.). Each fourth intact vertebral centra was scored for VO and 5‐mm thick coronal sections scanned in a specialized peripheral densitometer (GE Lunar Piximus DXA). Changes in BMD associated with age, sex, and VO severity were examined in the whole vertebral section, a strictly trabecular region, and a primarily cortical region of bone separately. Significant change in vertebral BMD was found to occur by middle age with little or no statistical change in BMD between middle and old age. Females appear to suffer greater bone loss at an earlier age with no change in BMD between middle and old age, whereas males show a more steady loss of BMD across the age groups. The bone mineral content and BMD of the cortical region is higher in individuals with pronounced/severe osteophytosis. The unusual age‐ and sex‐related patterns of change in vertebral BMD at Wharram Percy are compared with the patterns of age‐related change from recent longitudinal population‐based studies. The results emphasize the different pattern of bone loss in young adulthood seen in trabecular regions of the skeleton and highlight the importance of consideration of degenerative joint disease in BMD studies. The influence of lifestyle factors on vertebral BMD in this medieval population is also discussed. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc.
Pre‐Hispanic Mesoamerican demography approximates the present‐day ancestry of Mestizos throughout the territory of Mexico
Authors: Rubi‐Castellanos Rodrigo , Martínez‐Cortés Gabriela , Francisco Muñoz‐Valle José , González‐Martín Antonio , Cerda‐Flores Ricardo M. , Anaya‐Palafox Manuel , Rangel‐Villalobos Héctor
Published: January 2009

Over the last 500 years, admixture among Amerindians, Europeans, and Africans, principally, has come to shape the present‐day gene pool of Mexicans, particularly Mestizos, who represent about 93% of the total Mexican population. In this work, we analyze the genetic data of 13 combined DNA index system‐short tandem repeats (CODIS‐STRs) in 1,984 unrelated Mestizos representing 10 population samples from different regions of Mexico, namely North, West, Central, and Southeast. The analysis of molecular variance (AMOVA) test demonstrated low but significant differentiation among Mestizos from different regions (FST = 0.34%; P = 0.0000). Although the spatial analysis of molecular variance (SAMOVA) predicted clustering Mestizo populations into four well‐delimited groups, the main differentiation was observed between Northwest when compared with Central and Southeast regions. In addition, we included analysis of individuals of Amerindian (Purepechas), European (Huelva, Spain), and African (Fang) origin. Thus, STRUCTURE analysis was performed identifying three well‐differentiated ancestral populations (k = 3). STRUCTURE results and admixture estimations by means of LEADMIX software in Mestizo populations demonstrated genetic heterogeneity or asymmetric admixture throughout Mexico, displaying an increasing North‐to‐South gradient of Amerindian ancestry, and vice versa regarding the European component. Interestingly, this distribution of Amerindian ancestry roughly reflects pre‐Hispanic Native‐population density, particularly toward the Mesoamerican area. The forensic, epidemiological, and evolutionary implications of these findings are discussed herein. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc.
The goals of direct paternal care among a South Amerindian population
Authors: Winking Jeffrey , Gurven Michael , Kaplan Hillard , Stieglitz Jonathan
Published: January 2009

Human males are remarkable among mammals in the level of investment they provide to their wives and children. However, there has been debate as to the degree to which men actually invest and through which fitness pathways the benefits of familial investment are realized. Much of the previous research exploring these issues has focused on men's roles as providers, but few have explored correlates of men's direct parental care. Although this is reasonable given men's parental emphasis on provisioning, the providing of direct care is more straightforward with a clear provider and recipient and little ambiguity as to the care‐giver's intent. Here, we explore contextual correlates of men's direct care among the Tsimane of Bolivia to determine the extent to which such care is patterned to enhance its effectiveness in increasing child wellbeing and the efficient functioning of the family. We also explore whether Tsimane fathers provide care in ways that enhance the positive effect it has on the wife's perception of the care provider. Overall, we find that Tsimane men appear responsive to the needs of children and the family, but show that there is little evidence that men respond to factors expected to increase the impact that men's care has on their reputations with their wives. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc.
Effects of gut passage, feces, and seed handling on latency and rate of germination in seeds consumed by capuchins (Cebus capucinus)
Authors: Valenta Kim , Fedigan Linda M.
Published: January 2009

One of the key measures of the effectiveness of primary seed dispersal by animals is the quality of seed dispersal (Schupp: Plant Ecol 107/108 [1993] 15–29). We present data on quality of seed dispersal by two groups of white‐faced capuchins (Cebus capucinus) in Costa Rica to test the hypothesis that capuchin seed handling results in effective primary dispersal for some fruit species they consume. We examined seed handling for 27 plant species, and germination rates of 18 species consumed by capuchins. For five of the most commonly swallowed seed species, we determined germination rates and average time to germination (latency) for seeds ingested and defecated by capuchins and compared these to seeds removed directly from fruit and planted. For the same five species, we compared germination rates and latency for passed seeds planted in capuchin feces to those cleaned of feces and planted in soil. For three of five species, differences in proportion of germinated seeds were significantly higher for gut passed seeds than for controls. For four of five species, germination latency was significantly faster for gut passed seeds than for controls. Feces had either no effect on seed germination rate or precluded germination. Data presented here support the hypothesis that white‐faced capuchins are effective primary dispersers. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc.
The functional correlates of jaw‐muscle fiber architecture in tree‐gouging and nongouging callitrichid monkeys
Authors: Taylor Andrea B. , Eng Carolyn M. , Anapol Fred C. , Vinyard Christopher J.
Published: January 2009

Common (Callithrix jacchus) and pygmy (Cebuella pygmaea) marmosets and cotton‐top tamarins (Saguinus oedipus) share broadly similar diets of fruits, insects, and tree exudates. Marmosets, however, differ from tamarins in actively gouging trees with their anterior dentition to elicit tree exudates flow. Tree gouging in common marmosets involves the generation of relatively wide jaw gapes, but not necessarily relatively large bite forces. We compared fiber architecture of the masseter and temporalis muscles in C. jacchus (N = 18), C. pygmaea (N = 5), and S. oedipus (N = 13). We tested the hypothesis that tree‐gouging marmosets would exhibit relatively longer fibers and other architectural variables that facilitate muscle stretch. As an architectural trade‐off between maximizing muscle excursion/contraction velocity and muscle force, we also tested the hypothesis that marmosets would exhibit relatively less pinnate fibers, smaller physiologic cross‐sectional areas (PCSA), and lower priority indices (I) for force. As predicted, marmosets display relatively longer‐fibered muscles, a higher ratio of fiber length to muscle mass, and a relatively greater potential excursion of the distal tendon attachments, all of which favor muscle stretch. Marmosets further display relatively smaller PCSAs and other features that reflect a reduced capacity for force generation. The longer fibers and attendant higher contraction velocities likely facilitate the production of relatively wide jaw gapes and the capacity to generate more power from their jaw muscles during gouging. The observed functional trade‐off between muscle excursion/contraction velocity and muscle force suggests that primate jaw‐muscle architecture reflects evolutionary changes related to jaw movements as one of a number of functional demands imposed on the masticatory apparatus. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.
Diastereoselective Synthesis of Hexahydropyrrolo[2,1‐b]oxazoles by a Rhodium‐Catalyzed Hydroformylation / Silica‐Promoted Deformylation Sequence
Authors: Vasylyev Maxym , Alper Howard
Published: January 2009

Fliehendes Formyl: Die vorgestellte rhodiumkatalysierte Hydroformylierung von N‐Allyloxazolidinen in einer CO/H2‐Atmosphäre mit anschließender diastereoselektiver deformylierender Cyclisierung liefert in guten Ausbeuten Hexahydropyrrolo[2,1‐b]oxazole. Die Reaktion verläuft als einzigartige Hydroformylierungs‐Deformylierungs‐Folge, bei der die Formylgruppe gewissermaßen die {CH2O}‐Einheit des Oxazolidinheterocyclus ersetzt.

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Clean Absorption‐Mode NMR Data Acquisition
Authors: Wu Yibing , Ghosh Arindam , Szyperski Thomas
Published: January 2009

Die phasenverschobene gespiegelte Aufnahme („phase‐shifted mirrored sampling“, PMS) von indirekten Evolutionsperioden vieldimensionaler NMR‐Experimente liegt neuen Datenaufnahmeverfahren zugrunde, die ohne Anwendung einer Phasenkorrektur dispersive Signalkomponenten eliminieren, welche die Signalidentifikation erschweren und deren Maxima verschieben. Die erhöhte Auflösung ist von besonderem Interesse für Systeme mit nahezu entarteten chemischen Verschiebungen.

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Second‐Generation Synthesis of Azadirachtin: A Concise Preparation of the Propargylic Mesylate Fragment
Authors: Boyer Alistair , Veitch Gemma E. , Beckmann Edith , Ley Steven V.
Published: January 2009

Neuer Anlauf: Eine hocheffiziente Synthese des Propargylmesylat‐Fragments von Azadirachtin wurde entwickelt (siehe Schema; Bn=Benzyl, Ms=Methansulfonyl, PMB=para‐Methoxybenzyl, TBDPS=tert‐Butyldiphenylsilyl). Eine enantioselektive katalytische Hetero‐Diels‐Alder‐Reaktion liefert das C15‐Stereozentrum, das anschließend den weiteren Aufbau des Moleküls in insgesamt nur 17 Stufen steuert.

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XeF4 as a Ligand for a Metal Ion
Authors: Tavčar Gašper , Žemva Boris
Published: January 2009

Noble molecule: [Mg(XeF2)(XeF4)](AsF6)2 is the first coordination compound in which XeF4 acts as a ligand to a metal center. It is also the first known compound, in which XeF2 and XeF4 are simultaneously coordinated to the same metal center (see structure; purple Xe, green F, gray Mg, yellow As).

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Clean Absorption‐Mode NMR Data Acquisition
Authors: Wu Yibing , Ghosh Arindam , Szyperski Thomas
Published: January 2009

A new acquisition: Based on “phase‐shifted mirrored sampling” (PMS) of indirect evolution periods of multi‐dimensional experiments, new acquisition schemes eliminate, without application of a phase correction, dispersive signal components that exacerbate peak identification and shift peak maxima. The resulting enhanced resolution is of particular value for systems with high chemical shift degeneracy.

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Second‐Generation Synthesis of Azadirachtin: A Concise Preparation of the Propargylic Mesylate Fragment
Authors: Boyer Alistair , Veitch Gemma E. , Beckmann Edith , Ley Steven V.
Published: January 2009

A second bite of the apple: A new and highly efficient synthesis of the propargylic mesylate fragment of azadirachtin has been accomplished (see scheme; Bn=benzyl, Ms=methanesulfonyl, PMB=para‐methoxybenzyl, TBDPS=tert‐butyldiphenylsilyl). An enantioselective catalytic hetero Diels–Alder reaction sets up the stereocenter at C15, which then controls the installation of the remaining functionality in a total of only 17 steps.

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Enantioselective Synthesis of (+)‐Chamaecypanone C: A Novel Microtubule Inhibitor
Authors: Dong Suwei , Hamel Ernest , Bai Ruoli , Covell David G. , Beutler John A. , Porco John A.
Published: January 2009

A bicycle built for tubulin: The total synthesis of (+)‐chamaecypanone C has been achieved by using a tandem retro‐Diels–Alder/Diels–Alder cascade reaction (see scheme). Initial biological studies demonstrate that (+)‐chamaecypanone C is an inhibitor of tubulin assembly and binds at the colchicine site.

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Synthesis of (−)‐Berkelic Acid
Authors: Wu Xiaoxing , Zhou Jingye , Snider Barry B.
Published: January 2009

An extremophilic challenge: Stereospecific condensation of a fully functionalized ketal aldehyde and a 2,6‐dihydroxybenzoic acid is the key step in the synthesis of (−)‐berkelic acid confirming Fürstner's reassignment of the stereochemistry at C18 and C19, establishing the absolute stereochemistry, and tentatively assigning the stereochemistry at C22.

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Purification and partial characterization of glutathioneS‐transferase from insecticide‐resistant field populations ofLiposcelis paetaPearman (Psocoptera: Liposcelididae)
Authors: Wu Shuang , Dou Wei , Wu Jing‐Jing , Wang Jin‐Jun
Published: January 2009

Enzymes that possess glutathione S‐transferase (GST) activity were purified to homogeneity by glutathione‐agarose affinity chromatography from three field populations of Liposcelis paeta (Pearman). These populations were collected from Nanyang city of Henan Province (NY), Wuzhou (WZ) and Hezhou (HZ) cities of Guangxi Province, China, and had different susceptibilities to dichlorvos [LC50s of the NY (281.48 mg/m2), the WZ (285.07 mg/m2), and the HZ (243.52 mg/m2), respectively]. The specific activities of purified enzymes from these three populations increased 32.24‐, 99.81‐, and 42.52‐fold, respectively. Kinetic analyses showed that the catalytic activity of purified GST from NY population towards GSH was much higher than the others, while WZ population reached the highest in V. SDS–polyacrylamide electrophoresis revealed that the purified GST had two subunits with a molecular mass of 23.31 and 20.43 kDa for NY, 53.14 and 20.13 kDa for WZ, and 50.79 and 19.42 kDa for HZ, respectively. The in vitro inhibition studies of GSTs indicated that three kinds of insecticides (chlorpyrifos, carbosulfan, and cypermethrin) and five metallic ions (Zn2+, Ba2+, Ca2+, Hg2+, Mn2+, and Mg2+) all possessed inhibitory effects on purified GST, and ethacrynic acid (EA, a specific inhibitor of GST) expressed inhibitory effects. In the bioassay, three populations of L. paeta had different susceptibilities to different insecticides, even after they were reared on diets consisting of 25% EA. The GST activities of L. paeta from different areas also showed different temperature and pH stabilities. The differences in GST among the three populations may be attributed partially to the differences in control practices for psocids between Henan and Guangxi Provinces. © 2009 Wiley Periodicals, Inc.
Octopamine and 5‐hydroxytryptamine mediate hemocytic phagocytosis and nodule formation via eicosanoids in the beet armyworm,Spodoptera exigua
Authors: Kim Geun Seob , Nalini Madanagopal , Kim Yonggyun , Lee Dae ‐ Weon
Published: January 2009

Octopamine and 5‐hydroxytryptamine (5‐HT) have been known to mediate cellular immune responses, such as hemocytic phagocytosis and nodule formation, during bacterial invasion in some insects. In addition, eicosanoids also mediate these cellular immune reactions in various insects, resulting in clearing the bacteria circulating in the hemolymph. This study investigated a hypothesis on signal cross‐talk between both types of immune mediators in the beet armyworm,Spodoptera exigua,which had been observed in the effect of eicosanoids on mediating the cellular immune responses. In response to bacterial infection, octopamine or 5‐HT markedly enhanced both hemocytic phagocytosis and nodule formation inS. exigualarvae. Their specific antagonists, phentolamine (an octopamine antagonist) or ketanserin (a 5‐HT antagonist) suppressed both cellular immune responses ofS. exigua. These effects of biogenic monoamines on the immune mediation were expressed through eicosanoids because the inhibitory effects of both antagonists were rescued by the addition of arachidonic acid (a precursor of eicosanoid biosynthesis). Furthermore, the stimulatory effects of both monoamines on the cellular immune responses were significantly suppressed by different inhibitors acting at their specific levels of eicosanoid biosynthesis. Taken together, this study suggests that octopamine and 5‐HT can mediate hemocytic phagocytosis and nodule formation through a downstream signal pathway relayed by eicosanoids inS. exigua. © 2009 Wiley Periodicals, Inc.
Toxicity and disruption of midgut physiology in larvae of the European corn borer, Ostrinia nubilalis, by anion transporter blockers
Authors: Boina Dhana Raj , Bloomquist Jeffrey R.
Published: January 2009

In this study, four blockers of anion transporters (ATs) belonging to four different classes of organic acids, including DIDS (4, 4'‐diisothiocyanatostilbene‐2, 2'‐ disulfonic acid; a stilbene disulfonic acid), NPPB [(5‐nitro‐2‐(3‐phenylpropylamino) benzoic acid; an anthranilic acid)], 9‐AC (anthracene‐9‐carboxylic acid; an aromatic carboxylic acid), and IAA‐94 (indanyloxy acetic acid; an indanyloxy alkanoic acid), were tested for their toxicity against the European corn borer (ECB), Ostrinia nubilalis. All the AT blockers inhibited the growth of larvae, increased the developmental time, and decreased survival compared to controls, when second‐instar ECB larvae were fed for seven days on treated diet. In general, DIDS and NPPB were the most active compounds, with the rank order of activity being DIDS>NPPB>IAA‐94>9‐AC. All the AT blockers decreased the midgut alkalinity in fifth‐instar larvae when fed for 3 h on treated diet. Effective concentrations required for 50% decrease in midgut alkalinity (EC50) ranged between 29.1 and 41.2 ppm and the rank order of activity was NPPB>DIDS>IAA‐94>9‐AC. Similarly, all the tested AT blockers inhibited 36Cl− uptake from the midgut lumen in fifth‐instar larvae when fed for 3 h on treated diet. Concentrations required for 50% inhibition of 36Cl− uptake (IC50) ranged between 7.4 and 11.0 ppm and the rank order of activity was DIDS>NPPB>9‐AC >IAA‐94. Modest to highly strong positive correlations observed among growth, midgut alkalinity, and midgut Cl− ion transport in AT blocker–fed larvae suggested that these effects are causally related to each other. Finally, AT blockers have the potential to become good candidates for development of insecticides with a unique mode of action. © 2009 Wiley Periodicals, Inc.