bluuebunny/crossref_metadata_2025 huggingface dataset:
Model for a two‐cavity coating die with pressure and temperature deformation
Authors: Shetty Sneha , Ruschak Kenneth J. , Weinstein Steven J.
Published: December 2011

Coating dies uniformly distribute liquid for application as a film to moving substrates using one or two cavities spanning the coating width and adjoining precision narrow slots of much higher resistance to flow. If the slots are deformed by the pressure of the liquid or by temperature gradients in the die bars, degradation in flow distribution can result. Consequently, dies are designed to be sufficiently stiff and are thermally jacketed to keep slot deformations within fabrication tolerances. To aid in design and operation, a model of low computational load is developed in which the flow and deformation analyses are directly coupled. Die deformation is modeled using classical beam theory taking account of the varying thickness of the bars due to cavity geometry. Two‐dimensional finite element analysis of die deformation gives marginally higher slot deformation. Three‐dimensional finite element analysis agrees with the two‐dimensional analysis except near the center of the die where the symmetry boundary condition reduces deformation. The effects of die geometry on deformation and flow distribution are illustrated. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
Structure–property relationship studies in amine functionalized multiwall carbon nanotubes filled polypropylene composite fiber
Authors: Tambe Pankaj B. , Bhattacharyya Arup R. , Kamath Srikanth S. , Kulkarni Ajit R. , Sreekumar T.V. , Srivastav Anurag , Rao K.U. Bhasker , Liu Yaodong , Kumar Satish
Published: December 2011

Amine functionalized multiwalled carbon nanotubes (a‐MWNT) based polypropylene (PP) composite fibers were prepared in the presence of polypropylene‐g‐maleic anhydride (PP‐g‐MA) by melt‐mixing followed by melt‐spinning with subsequent post‐drawing of the as‐spun fibers of varying draw ratio (DR). In order to enhance the interfacial interaction, a‐MWNT were utilized in combination with PP‐g‐MA during melt‐mixing. Fourier transform infrared spectroscopic analysis revealed the formation of imide bonds between MA functionality of PP‐g‐MA and amine functional group of a‐MWNT. Higher tensile properties of PP/a‐MWNT/PP‐g‐MA composite fibers were registered with varying DR of the as‐spun fiber. Orientation factors of a‐MWNT and PP chains along the fiber axis were correlated with the higher tensile modulus and tensile strength of PP/a‐MWNT/PP‐g‐MA composite fiber of varying DR. Crystallization studies indicated the role of hetero‐nucleating action of a‐MWNT in PP/a‐MWNT/PP‐g‐MA composite fiber. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
Investigation of Cu(In,Ga)Se2 thin‐film formation during the multi‐stage co‐evaporation process
Authors: Caballero R. , Kaufmann C. A. , Efimova V. , Rissom T. , Hoffmann V. , Schock H. W.
Published: December 2011

In order to transfer the potential for the high efficiencies seen for Cu(In,Ga)Se2 (CIGSe) thin films from co‐evaporation processes to cheaper large‐scale deposition techniques, a more intricate understanding of the CIGSe growth process for high‐quality material is required. Hence, the growth mechanism for chalcopyrite‐type thin films when varying the Cu content during a multi‐stage deposition process is studied. Break‐off experiments help to understand the intermediate growth stages of the thin‐film formation. The film structure and morphology are studied by X‐ray diffraction and scanning electron microscopy. The different phases at the film surface are identified by Raman spectroscopy. Depth‐resolved compositional analysis is carried out via glow discharge optical emission spectrometry. The experimental results imply an affinity of Na for material phases with a Cu‐poor composition, affirming a possible interaction of sodium with Cu vacancies mainly via In(Ga)Cu antisite defects. An efficiency of 12.7% for vacancy compound‐based devices is obtained. Copyright © 2011 John Wiley & Sons, Ltd.
Annual performance enhancement of building integrated photovoltaic modules by applying phase change materials
Authors: Hendricks J. H. C. , van Sark W. G. J. H. M.
Published: December 2011

The performance of photovoltaic (PV) module outdoors suffers from attained high module temperatures due to irradiation as a result of the negative temperature coefficient of their efficiency. Phase change materials (PCMs) are investigated as an option to regulate photovoltaic module temperature and thereby reduce its electrical efficiency decrease. In this study, a simplified heat balance model is used to calculate the extra energy gain; such a PV/PCM system can bring on an annual basis. With present day commercially available PCM materials, a moderate increase of up to 3% of the total energy output can be expected. When taking into account the additional PCM material cost, a PV/PCM module presently is not economically viable. For an acceptable payback period of 10–20 years to be reached, the heat storage capacity of a PCM would require an increase of about one order of magnitude, which is presently not realistic. Nevertheless, a combination with building climate control in which the PCM plays a double role controlling both the PV temperature as well as the inside climate temperature may be feasible. Copyright © 2011 John Wiley & Sons, Ltd.
Thoracic Hyperkyphosis: A Survey of Australian Physiotherapists
Authors: Perriman Diana M. , Scarvell Jennifer M. , Hughes Andrew R. , Lueck Christian J. , Dear Keith B. G. , Smith Paul N.
Published: December 2011

Background

Age‐related thoracic hyperkyphosis can lead to poor health outcomes including pain and dysfunction. Physiotherapists are fundamentally involved in the assessment and treatment of this problem but there is no published data that details assessment and treatment strategies or the attitudes of practitioners with respect to hyperkyphosis.

Purpose

The purpose of the study is to ascertain current physiotherapy practice for, and attitudes to, the assessment and treatment of thoracic hyperkyphosis in Australia.

Method

A stratified random sample (N = 468) of Australian physiotherapists in all states and territories working in hospitals, outpatient clinics and community clinics were sent an anonymous cross‐sectional postal survey. The survey had six sections identifying clinical profile, prevalence, measurement strategy, treatment frequency, treatment strategy and evidence source.

Results

A response rate of 47% with anonymity preserved was achieved. The majority of respondents had a musculoskeletal practice profile (75%). Seventy‐eight per cent encountered hyperkyphosis at least weekly, and three treatment sessions were most commonly given (35%). Visual inspection was almost universally used to assess the degree of hyperkyphosis (98%), and for 64% it was their only measurement tool. Postural re‐education was the most common treatment strategy (90%) but the range of treatments reported was diverse. The primary source of evidence used by the majority of respondents was their undergraduate education, and there was concern expressed that physiotherapists lack good evidence upon which to make therapeutic decisions about hyperkyphosis.

Conclusions

Thoracic hyperkyphosis is commonly encountered by physiotherapists. Measurement of treatment efficacy is highly subjective, and the treatment modalities employed are diverse. Many physiotherapists based their management of hyperkyphosis on their undergraduate education alone. Copyright © 2011 John Wiley & Sons, Ltd.
Immunostimulation of Sugar Cane Extract on Neutrophils to Salmonella typhimurium Infection in Mice
Authors: Chen Ming‐Hua , Lo Dan‐Yuan , Liao Jiunn‐Wang , Hsuan Shih‐Ling , Chien Maw‐Sheng , Lin Cheng‐Chung , Chen Ter‐Hsin , Lee Wei‐Cheng
Published: December 2011

The aim of this study was to evaluate the immunomodulatory effects of sugar cane extract (SCE) on the biological activities of neutrophils in mice. Six‐week‐old BALB/c mice were fed 1250 mg/kg of SCE once. The generation, migration and biological functions of neutrophils and the survival rates of the mice in response to Salmonella typhimurium infection were evaluated. The results show that the numbers of both bone marrow cells and neutrophils were significantly increased in response to SCE administration (p < 0.05) compared with controls. The migration, phagocytosis and H2O2 generation of neutrophils were all significantly enhanced in SCE‐treated mice (p < 0.05). After challenge with S. typhimurium (lethal dose, 50% (LD50)), SCE‐treated mice had a 19.2% higher survival rate and milder hepatic lesions than the controls. Additionally, fewer invasive bacteria were recovered from the spleens of SCE‐treated mice. In conclusion, our results suggest that SCE has a positive regulatory effect on the biological function of mouse neutrophils that may increase host resistance against bacterial infections. Copyright © 2011 John Wiley & Sons, Ltd.
2,3,4′,5‐Tetrahydroxystilbene‐2‐O‐β‐d‐glucoside Inhibits Proliferation of Vascular Smooth Muscle Cells: Involvement of NO/cGMP/PKG Pathway
Authors: Xu Xiao‐Le , Huang Yan‐Juan , Chen Xiang‐Fan , Lin Dan‐Yan , Zhang Wei
Published: December 2011

The proliferation of vascular smooth muscle cells (VSMCs) induced by injury to the intima of arteries is an important etiologic factor in vascular proliferative disorders such as atherosclerosis and restenosis. 2,3,4′,5‐Tetrahydroxystilbene‐2‐O‐β‐d‐glucoside (TSG), an active component extracted from Polygonum multiflorum, has been found to have an antiatherosclerotic effect. The aim of this study was to investigate the effects of TSG on platelet derived growth factor (PDGF)‐BB induced VSMCs proliferation and to explore the possible mechanisms of such effects. Pretreatment of VSMCs with TSG significantly inhibited PDGF‐BB‐induced cell proliferation in a concentration‐dependent but not time‐dependent manner. In addition, flow cytometry analysis of the DNA content revealed blocking of the PDGF‐BB‐inducible cell cycle progression by TSG. On the contrary, an inhibitory effect of TSG on VSMCs proliferation and expression of cell cycle regulators were markedly attenuated by addition of an nitric oxide (NO) synthase inhibitor, a soluble guanylate cyclase inhibitor and a cyclic GMP (cGMP)‐dependent protein kinase (PKG) inhibitor: NG‐nitro‐L‐arginine methyl ester (L‐NAME), 1H‐[1,2,4] oxadiazolo [4,3‐α] quinoxalin‐1‐one (ODQ) and KT5823, respectively. It was also demonstrated that TSG enhanced NO and cGMP formation through up‐regulating endothelial NO synthase expression in VSMCs. The findings indicate that TSG inhibited VSMCs proliferation induced by PDGF‐BB may involve the NO/cGMP/PKG signal pathway. Copyright © 2011 John Wiley & Sons, Ltd.
Hepatoprotective Effect of Filipendula hexapetala Gilib. (Rosaceae) in Carbon Tetrachloride‐induced Hepatotoxicity in Rats
Authors: Ćebović Tatjana , Maksimović Zoran
Published: December 2011

The influence of methanol extract produced from the flowers of Filipendula hexapetala Gilib. (Rosaceae) on some liver biochemical parameters in rats intoxicated with carbon tetrachloride (CTC) was evaluated in this study. The results Obtained revealed that pretreatment with the extract investigated inhibited CTC‐induced liver injury by decreasing lipid peroxidation and increasing the content of reduced glutathione in a dosage dependent manner, bringing the levels of all antioxidant enzymes close to control values. The administration of CTC diminished hepatic antioxidant defense mechanisms by significant reduction of peroxidase and catalase activities. The catalase activity was significantly recovered in groups treated with the extract investigated and intoxicated with a single CTC dose. A similar impact on hepatic peroxidase activity has also been observed, indicating a partial detoxication of hydrogen peroxide by both catalase and peroxidase. Copyright © 2011 John Wiley & Sons, Ltd.
Evaluation of computer‐assisted jaw reconstruction with free vascularized fibular flap compared to conventional surgery: a clinical pilot study
Authors: Modabber Ali , Legros Christina , Rana Majeed , Gerressen Marcus , Riediger Dieter , Ghassemi Alireza
Published: December 2011

Background

The introduction of computer‐assisted surgery was a milestone in functional reconstructions of facial skeletal defects.

Patients and methods

We compared five computer‐assisted and five conventional reconstructions with fibular grafts in the course of a pilot study. A rapid prototyping guide translated the computer‐assisted surgery plan into intraoperative utilizable models. We intraoperatively measured the time needed for shaping the graft to the recipient site and the ischaemic time. Furthermore, the size of donor site defect compared to the required transplant length was evaluated.

Results

Shaping procedure and ischaemic time turned out significantly shorter when compared to conventional surgery without cutting guide (p = 0.014). Using surgical guides, there was no change between the defect size of the fibula and the necessary transplant size. In conventional surgery, a mean change of 1.92 cm occurred (p = 0.001).

Conclusion

The surgical guide significantly reduced shaping time and consequently ischaemic time. These factors can influence flap survival. The fibular donor site defect was downsized. Copyright © 2011 John Wiley & Sons, Ltd.
XPS analysis of glassy carbon electrodes chemically modified with 8‐hydroxyquinoline‐5‐sulphonic acid
Authors: Brunetti B. , De Giglio E. , Cafagna D. , Desimoni E.
Published: December 2011

Glassy carbon (GC) modified electrodes were obtained by cycling the potential in an 8‐hydroxyquinoline‐5‐sulphonic acid (HQSA) solution. These electrodes were successfully tested as sensors of some species of alimentary and pharmaceutical interest, showing improved performances with respect to those of unmodified GC electrodes and of GC electrodes cycled under the same experimental conditions but in the absence of HQSA. As a matter of fact, in the wide potential range explored for modifying the electrodes, even in the absence of HQSA, complex redox processes leading to the production of several functional groups take place at the surface of glassy carbon itself. An XPS investigation was consequently performed to better understand the effective nature of active species present on the surface of HQSA modified electrodes. The spectroscopic experiments involved acquiring survey and detailed scans of an HQSA powder standard sample and of GC electrodes cycled both in the presence and in the absence of HQSA. The experimental value of the binding energy of the S2p3/2 level of HQSA‐modified electrodes was found equal to that of the HQSA standard powder, thus confirming that HQSA molecules are adsorbed on the surface of the GC/HQSA electrodes and that they maintain their chemical structure and properties. Copyright © 2011 John Wiley & Sons, Ltd.
Simultaneous measurement of photoluminescence and Raman scattering spectra from suspended single‐walled carbon nanotubes
Authors: Kono Kaname , Matsumoto Daiki , Chiashi Shohei , Homma Yoshikazu
Published: December 2011

Single‐walled carbon nanotubes (SWNTs) are interesting material, owing to their one‐dimensional structure. Photoluminescence (PL) spectroscopy and resonant Raman scattering spectroscopy are important measurement techniques to characterize SWNTs. The simultaneous measurements of PL and Raman scattering spectra have been performed for SWNT samples, which were wrapped with surfactant and dispersed on substrates. Here, we developed the simultaneous measurement technique of PL and Raman scattering from a perfectly isolated SWNT. The isolated SWNT was suspended between a pair of silica pillars, and it was free from any substances. The laser beam generated from a Ti : sapphire laser was focused with objective lens to spot size of 1.6 µm in diameter for the excitation of a suspended SWNT. Raman scattering and PL emission light from an SWNT were separated with a dichroic mirrors and introduced into each monochromator. By using the simultaneous measurement, the intensity profiles along a suspended SWNT were compared between PL and Raman scattering, which showed rapid quenching of PL signals at the pillars. Copyright © 2011 John Wiley & Sons, Ltd.
Behavior of major and rare-earth elements during the postmagmatic alteration of kimberlites
Authors: Vasilenko V.B. , Kuznetsova L.G. , Minin V.A. , Tolstov A.V.
Published: December 2011

During serpentinization and subsequent alteration in the absence of brucite, kimberlites accumulate uncompensated silica. Its amount can be calculated from the average compositions of the rock-forming minerals (olivine, calcite, phlogopite) and the chemical compositions of the rocks. The contents of rock-forming oxides and REE were determined in 12 kimberlite pipes of the Yakutian kimberlite province, in 413 samples from secondary-alteration zones and of unaltered kimberlites. Columns of successive kimberlite alterations were constructed for each pipe on the basis of secondary-quartz data; here, the behavior of rock-forming oxides and REE was assessed. All the studied rocks had experienced different degrees of postmagmatic hydrothermal metasomatism at different depths in all the pipes. The changes were reflected in the supply/loss of rock-forming oxides and REE. The supply of REE during the hydrothermal metasomatism enriched the kimberlites with TiO2, P2O5, and CaO. During the removal of REE, most of the rock-forming oxides were partially lost. The maximum REE supply was 67% in the Udachnaya-Vostochnaya pipe and 59% in the Nyurbinskaya pipe as compared with the unaltered kimberlites. The maximum REE loss was 87% in the Aikhal pipe and 81% in the Internatsional’naya pipe as compared with the unaltered kimberlites. The initial REE contents of the postmagmatically altered kimberlites changed considerably in all the studied cases. This conclusion was drawn owing to the use of normative-quartz content as a criterion for secondary alteration.
The Karchiga copper massive sulfide deposit in the high-grade metamorphosed rocks of the Kurchum block: geologic structure, formation, and metamorphism (Rudny Altai)
Authors: Lobanov K.V. , Gaskov I.V.
Published: December 2011

The Karchiga copper massive sulfide deposit is located in the Kurchum block of high-grade metamorphosed rocks. This block is part of the Irtysh shear zone, which belongs to the largest transregional fault in Central Asia. The deposit is associated with the gneiss–amphibolite middle unit of the metamorphic complex, which is distinct in the geochemical fields. The mineralization is spatially and paragenetically related to the amphibolite beds, which are ore-bearing together with terrigenous rocks.

The deposit contains two spatially isolated lodes, in which all the discovered commercial reserves concentrate. They conformably overlie the host rocks and are tabular or ribbonlike. The mineralization has a close spatial relationship with Mg-rich anthophyllite-containing rocks. The sulfide ores are disseminated or massive and comprise pyrite, chalcopyrite, pyrrhotite, sphalerite, and magnetite. The ore is of Zn–Cu composition, in which Cu dominates considerably over Zn (average contents 2 and 0.4%, respectively; Cu/(Cu + Zn) = 0.83). The ores are rich in Co (up to 0.16%, averaging 0.02%), poor in Au and Ag (0.3 and 7.2 ppm, respectively), and almost free of Pb and Ba.

All the rocks and ores experienced epidote–amphibolitic metamorphism. Meanwhile, the ores experienced a recrystallization and partial regeneration, but the initial shape of the lodes remained unchanged.

The essentially chalcopyritic ores, the volcaniclastic ore-bearing rocks, and the spatial and genetic relationship of the mineralization with undifferentiated mafic and siliciclastic rocks suggest that this deposit belongs to the Besshi type, formed in a back-arc environment, near large rises.

The studies show that Besshi-type Cu–Zn massive sulfide deposits differ from most of the polymetallic (Kuroko-type) deposits in Rudny Altai in the composition of volcanics and geodynamic settings, but belong to the same evolutionary series in this VMS province. Both types of deposits might have formed in the Paleozoic, during the main peak of VMS generation in the Earth’s history.
Geoelectrical studies of the Chuya basin sedimentary fill (Gorny Altai)
Authors: Deev E.V. , Nevedrova N.N. , Zol’nikov I.D. , Rusanov G.G. , Ponomarev P.V.
Published: December 2011

The VES method was used to determine the geoelectric parameters of Cenozoic rocks in the Chuya intermontane basin. It was shown that the polyfacies and polychromous sediments filling the basin are well differentiated by their electrical parameters. A combination of methods used in data acquisition and processing, due to their high resolution capacity at shallow depths, provided information on the structure and physical properties of the Chuya rocks from surface to depths of 250–300 m. Despite a reasonable consistence among these methods to the above depths, the VES method is a more effective tool for detecting shallower layers. Interpretation of the VES data proved the existence of a large outburst channel as new geological evidence for an ice-dammed origin of the Middle Neopleistocene lake. A more detailed layering of the topmost part of the geoelectrical section across the Irbistu–Kokozek interfluve using the VES data revealed a number of fine-grained lenticular structures of the ancient lakes in the Chuya depression, which are hidden beneath a cover of fluvioglacial and lacustrine bouldery pebbles and moraine diamictons.
Influence of the off-axis position of the transmitter and receiver circuits on the results of differentially normalized electromagnetic sounding
Authors: Ageenkov E.V. , Davydenko Yu.A. , Fomitskii V.A.
Published: December 2011

In the differentially normalized method of electromagnetic sounding (DNME), the transmitter and receiver are grounded electrical circuits. The conduction and polarization properties of a section are studied by measuring the electrical potential difference (ΔU(t)) and the second potential difference (Δ2U(t)); the latter characterizes the spatial inhomogeneity of the electromagnetic field. Measurements of Δ2U(t) are strongly influenced by three-dimensional inhomogeneities within the receiver spread. To reduce this effect, measurements are made in two positions (left and right) of the transmitter circuit relative to receiver with subsequent averaging of the measured data. Often in field studies, the transmitter and receiver circuits are at an angle to each other, and the use of two transmitters in measurements leads to the need to determine a generalized transmitter for one-dimensional forward numerical modeling of field data.

The effect of the off-axis (diagonal) position of the transmitter and receiver circuits on the data of electromagnetic pulse sounding and their inversion for a one-dimensional polarizable conducting medium have been studied in real and numerical experiments. In modeling, the effect of induced polarization (IP) is taken into account by introducing the resistivity frequency dispersion (Cole-Cole equation). Validity of the calculation of the generalized transmitter is estimated for the solution of the one-dimensional forward problem with the inversion of field diagonal measurements. The effect of three-dimensional objects on the results of measurements using the above observation system is estimated by solving the 3D forward problem for a polarizable conducting medium.
ResurrectingSeva(Social Service): Dalit and Low-caste Women Party Activists as Producers and Consumers of Political Culture and Practice in Urban North India
Authors: Ciotti Manuela
Published: December 2011

This article examines Dalit (ex-untouchable) and low-caste women activists within the Bahujan Samaj Party (BSP) in the north Indian state of Uttar Pradesh. Underrepresented in Indian political history, these women frequently portray political activities assevaor social service, thus recalling upper caste/class notions of self-sacrifice and philanthropy of colonial memory.Seva, however, finds no place within the history of Dalit politics articulated through a language of rights. This article argues there exists an interlocking relation between the resurgence ofsevaand the process of upward class mobility that was a precondition to both the creation of the BSP and women's political participation within it. Further, it suggests that women activists appropriate and re-enact gender idioms and models coined in colonial India, refashioning them for the exigencies of contemporary politics. In turn, this points to the presence of shared structures of gendered political agency cutting across time, class, and caste among Dalit/low-caste communities usually considered as “other.” In addition, this ethnographic focus on agency challenges the usual trope of Dalit/low-caste women as “victims,” offering a critique of the burgeoning field of Dalit studies.
Mobile-izing: Democracy, Organization and India's First “Mass Mobile Phone” Elections
Authors: Jeffrey Robin , Doron Assa
Published: December 2011

We argue that the 2007 state elections in Uttar Pradesh (UP), India's largest state, were the first “mass mobile phone” elections in India. The paper charts the spectacular growth of the cheap cell phone in India and in Uttar Pradesh, documents the organizational strengths of the Bahujan Samaj Party (BSP), and explains how a party once based on Dalit (ex-Untouchable, or Scheduled Caste) support was able to cooperate with Brahmins. In these processes the mobile phone acted as a remarkable “force multiplier” to the existing BSP organization and helped party workers to circumvent the general hostility of mainstream media. The paper does not contend that the mobile phone won the 2007 elections; rather, it argues that the BSP was able to exploit a potent new tool, ideally suited to poor people who often were limited in their ability to travel. The paper points to similarities with the Obama campaigns of 2008 and notes that though other political groups in India attempt to imitate the methods, they may lack the essential organization and dedicated workers.
Plastic plasma as a compressor of aluminum plasma at the PALS experiment
Authors: Kasperczuk A. , Pisarczyk T. , Chodukowski T. , Kalinowska Z. , Gus'kov S.Yu. , Demchenko N.N. , Klir D. , Kravarik J. , Kubes P. , Rezac K. , Ullschmied J. , Krousky E. , Pfeifer M. , Rohlena K. , Skala J. , Pisarczyk P.
Published: December 2011

In our earlier papers, we demonstrated that plasma pressure decreases with the growing atomic number of the target material. That experimentally confirmed fact brought about a question whether it would be possible to collimate the Al plasma outflow by using plastic plasma as a compressor. To prove that idea we used in our next experiments a plastic target with an Al cylindrical insert of 400 µm in diameter. The measurements were carried out at the Prague Asterix Laser System iodine laser facility. The laser provided a 250 ps (full width at half maximum (FWHM)) pulse with energy of 130 J at the third harmonic frequency (λ3 = 0.438 µm). The focal spot diameters (ΦL) 800, 1000, and 1200 µm ensured predominance of the plastic plasma amount high enough for the effective Al plasma compression. To study the Al plasma stream propagation and its interaction with plastic plasma a three-frame interferometric system and an X-ray camera were used. The experiment provided a proof that creation of the collimated Al plasma jet by action of outer plastic plasma is feasible. In order to discuss of the experimental results a thorough theoretical analysis was carried out.
Late Classic Architectural Sculpture Themes in Copan
Authors: Fash Barbara W.
Published: December 2011

The architectural sculpture legacy of Late Classic Copan provides a source for understanding the sociopolitical and ideological adaptations of the rulers of this ancient city. Fieldwork conducted since 1985 has been directed toward documentation and conservation of the tens of thousands of mosaic sculpture facade pieces covered for centuries by collapsed debris or lichens. Hypothetical reconstructions of motif configurations and their rearticulation within building facades compose larger iconographic themes. The iconological study of these compositions opens a window for analyzing the nature of the religious and political symbolism produced by the last four rulers of Copan. Using these data, a shift from the cosmological and fertility themes employed by the thirteenth and fourteenth rulers to the emphasis on warfare by the fifteenth and sixteenth rulers can be documented.
Chronological Research at Copan:Methods and implications
Authors: Freter AnnCorinne
Published: December 2011

As a consequence of long-term archaeological research at Copan, 1,425 archaeological sites containing 4,507 structures have been located and mapped over an area of 135 km2. As part of the PAC II research, 200 archaeological sites representing a 15% stratified random sample of all valley sites were test excavated from 1983–1989. From these excavations, 2,150 obsidian hydration dates were processed, representing the largest number of chronometric dates from controlled contexts currently available from any southern Lowland Maya site. Based on this chronological research, there appears to be an excellent fit with various other available chronological techniques for all time phases except the ending date of the important Coner ceramic phase, which now appears to have extended to A.D. 1250. This more detailed Copan chronology suggests that the political collapse of the Main Group and immediate vicinity was quite sudden, taking place c. A.D. 800–830. Beyond that, however, the chronometric data provide evidence that some of the secondary elite, or lineage heads, and large numbers of rural commoners continued to reside within the valley in reduced courtyard groups or small rural hamlets for about 400 years following the decentralization of the Copan polity.
Hieroglyphs and Archaeology at Copan
Authors: Stuart David
Published: December 2011

The study of Copan's extensive hieroglyphic texts has grown hand in hand with long-term architectural excavations. Recent progress in Maya decipherment, much of it derived from work at Copan, now allows for new and potentially rewarding opportunities to integrate epigraphy and “dirt” archaeology. Toward this end, this paper provides an overview of the current knowledge of Copan's elite history, summarizing current knowledge of the ruler sequence and attributions of monuments and architecture to individual reigns. Thematic and stylistic changes are evident in the inscriptions between the Early and Late Classic periods, including a proliferation of subordinate elite texts in the decades leading up to political collapse. Also, new information is provided on the changing relations between Copan and Quirigua throughout the Classic period.
XTOBO, YUCATAN, MEXICO, AND THE EMERGENT PRECLASSIC OF THE NORTHERN MAYA LOWLANDS
Authors: Anderson David S.
Published: December 2011

Traditionally, research on the Preclassic Maya has focused on settlements found in the Southern Maya Lowlands. Apart from work at a few well-known archaeological sites in the Northern Lowlands, such as Komchen, Dzibilchaltun, and Yaxuna, the Preclassic Northern Maya had received relatively little attention from scholars. In recent years, however, many previously unreported archaeological sites with Preclassic materials have come to light. In northwest Yucatan, Mexico, a survey carried out by Proyecto Costa Maya encountered 140 sites with Preclassic components, including the site of Xtobo. Xtobo stood out from its neighboring Preclassic sites due to its extent and the size and complexity of its architecture. In addition, initial surveys of the site suggested that it was never reoccupied after the Preclassic period, thereby making it a valuable site for studying the Preclassic period in the Northern Maya Lowlands. After three seasons of fieldwork, the Proyecto Arqueologico de Xtobo was able to build substantially on the initial findings of the Proyecto Costa Maya, mapping 67 ha of settlement, including 387 structures, and carrying out a stratified sample of test pit excavations throughout the site. The project documented a dense and well-organized settlement, which included complex architectural features, such as pyramids, triadic groups, elite residences, and a ballcourt. The settlement at Xtobo shows many signs of a complex sociopolitical organization and interaction with other areas of the Maya region and Mesoamerica. The results of the Proyecto Arqueologico de Xtobo indicate that the Northern Maya Lowlands were an important and integral part of Preclassic Mesoamerica and should be considered in larger cultural reconstructions of the time period.
THREAD PRODUCTION IN EARLY POSTCLASSIC COASTAL OAXACA, MEXICO: TECHNOLOGY, INTENSITY, AND GENDER
Authors: King Stacie M.
Published: December 2011

Excavations at the site of Río Viejo in coastal Oaxaca, Mexico, yielded evidence of intensive cotton thread production during the Early Postclassic (a.d.975–1220). Spindle whorls were recovered in relatively large quantities in and around houses at Río Viejo, indicating that thread production was interspersed with other household activities and residents likely produced enough thread for local use and for export. Measurements of coastal spindle whorls show that the Río Viejo thread was unique compared to other coastal and highland sites in Oaxaca and Mesoamerica beyond. I argue that this uniqueness may in part stem from the particular variety of cotton that they were spinning, but also might reflect an interregional demand for their thread. The whorl data are presented in multiple ways to compare to other sites where intensive thread production has been proposed. Here, I discuss the problems inherent in whorl calculations and make a call for more standardized recording, ideally with volumetric density measures. In the final section of the paper, I use mortuary data and other lines of evidence to re-evaluate the ethnohistorically-documented relationship between women and textile production. In coastal Oaxaca, the evidence suggests that thread production was not linked to specific gender identities in a way that is marked archaeologically. Instead, adult members of households in coastal Oaxaca materially emphasized a shared group identity over any specific gender-based identities. The production of thread was a broadly shared household-level practice that involved multiple producers, which both created and reinforced social bonds between residents and provided Early Postclassic residents with secure and comfortable access to highland goods, paving the way for the more developed thread production industry in the Late Postclassic period.
THE CENTRAL ROLE OF CAVE ARCHAEOLOGY IN THE RECONSTRUCTION OF CLASSIC MAYA CULTURE HISTORY AND HIGHLAND-LOWLAND INTERACTION
Authors: Woodfill Brent
Published: December 2011

The unexpected discovery of an elaborate stone coffer with lowland-style carved images and early Maya inscriptions in a cave in the northern Guatemalan highlands has great implications for our understanding of highland-lowland interaction. However, this discovery proved to be only the “tip of the iceberg” in terms of the importance of subterranean evidence in this region. Investigations in caves in central Guatemala over the past decade have been a central part of the regional investigations, often directing subsequent reconnaissance, settlement surveys, and site excavations. Indeed, the early history of the region and the trade route passing through it has largely been reconstructed from evidence in cave shrines along the mountain valley routes from Kaminaljuyu and the Valley of Guatemala to lowland Maya sites. This article reviews this evidence, which also demonstrates how cave assemblages can be used not merely to study ancient ritual, but to examine broad problems in culture history and critical elements in the study of elite power, ceramic production, settlement patterns, interregional trade, and ancient economy.
SOCIAL MEMORY AND THE ORIGINS OF MONTE ALBAN
Authors: Winter Marcus
Published: December 2011

The founding of Monte Alban marked the beginning of the urban revolution in Oaxaca and a reorganization of Zapotec culture and society, which soon had repercussions among Mixtecs and other Otomangue groups in highland Oaxaca. While local factors contributed to Monte Alban's origins, the architectural expression of the city's core, consisting of a main plaza with leaders’ dwellings on each side and a ceremonial precinct at one end, comes from the Mixe-Zoque area, probably La Venta or highland Chiapas. One of the earliest architectural monuments at Monte Alban is the Danzantes Wall with carved stones that portray founding participants, including many chiefs from valley communities, as interpreted, imagined and remembered by the city's leader or leaders, years after the event. The wall was short-lived, partly dismantled within a few generations of its completion, and the carved stones reused, erasing the narrative's original significance. In contrast, elements of the city's core layout persisted at least until the end of the Late Classic as a template, remembered and repeated, sometimes with modifications at Monte Alban and elsewhere, of how a city should be.
LOS CERROS DE TRINCHERAS EN EL PAISAJE CULTURAL SONORENSE: ¿EVIDENCIA DE MEMORIA COLECTIVA?
Authors: Acosta César Villalobos
Published: December 2011

En el actual territorio de Sonora, México, la adopción de la agricultura y el sedentarismo estuvieron acompañados de un profundo cambio reflejado tanto en la emergencia de la cerámica como en el patrón de asentamiento entre los años 200 a 1450 d.C. Uno de estos desarrollos culturales es lo que ahora conocemos como la cultura Trincheras. Se piensa que hacia el 900 d.C. el paisaje cultural fue transformado por la aparición de asentamientos en los cerros que se conocen genéricamente como cerros de trincheras. Parecería que el emplazamiento de estos sitios no fue parte de un proceso homogéneo en su presente, sino el producto de sucesos interconectados con su pasado. En ellos, la memoria colectiva pudo haber tenido un rol fundamental en los rechazos y permanencias observadas en la cultura material. El objetivo del presente artículo es discutir las características de dos cerros de trincheras y cómo éstos pudieron haber sido el referente en la memoria colectiva de la sociedad prehispánica del noroeste de México durante el 900–1450 d.C.
INTRODUCTION TO OIL PRICE SHOCKS
Authors: Serletis Apostolos , Elder John
Published: December 2011

The relationship between the price of oil and the level of economic activity is a fundamental empirical issue in macroeconomics. Hamilton (1983) showed that oil prices had significant predictive content for real economic activity in the United States prior to 1972, whereas Hooker (1996) argued that the estimated linear relations between oil prices and economic activity appear much weaker after 1973. In the debate that followed, several authors suggested that the apparent weakening of the relationship between oil prices and economic activity is illusory, arguing that the true relationship between oil prices and real economic activity is asymmetric, with the correlation between oil price decreases and output significantly different from the correlation between oil price increases and output—see, for example, Mork (1989) and Hamilton (2003).
An overview of Ciao and its design philosophy
Authors: HERMENEGILDO M. V. , BUENO F. , CARRO M. , LÓPEZ-GARCÍA P. , MERA E. , MORALES J. F. , PUEBLA G.
Published: December 2011

We provide an overall description of the Ciao multiparadigm programming system emphasizing some of the novel aspects and motivations behind its design and implementation. An important aspect of Ciao is that, in addition to supporting logic programming (and, in particular, Prolog), it provides the programmer with a large number of useful features from different programming paradigms and styles and that the use of each of these features (including those of Prolog) can be turned on and off at will for each program module. Thus, a given module may be using, e.g., higher order functions and constraints, while another module may be using assignment, predicates, Prolog meta-programming, and concurrency. Furthermore, the language is designed to be extensible in a simple and modular way. Another important aspect of Ciao is its programming environment, which provides a powerful preprocessor (with an associated assertion language) capable of statically finding non-trivial bugs, verifying that programs comply with specifications, and performing many types of optimizations (including automatic parallelization). Such optimizations produce code that is highly competitive with other dynamic languages or, with the (experimental) optimizing compiler, even that of static languages, all while retaining the flexibility and interactive development of a dynamic language. This compilation architecture supports modularity and separate compilation throughout. The environment also includes a powerful autodocumenter and a unit testing framework, both closely integrated with the assertion system. The paper provides an informal overview of the language and program development environment. It aims at illustrating the design philosophy rather than at being exhaustive, which would be impossible in a single journal paper, pointing instead to previous Ciao literature.
Mountain ranges favour vigorous Atlantic meridional overturning
Authors: Sinha Bablu , Blaker Adam T. , Hirschi Joël J.‐M. , Bonham Sarah , Brand Matthew , Josey Simon , Smith Robin S. , Marotzke Jochem
Published: December 2011

We use a global Ocean‐Atmosphere General Circulation Model (OAGCM) to show that the major mountain ranges of the world have a significant role in maintenance of the Atlantic Meridional Overturning Circulation (AMOC). A simulation with mountains has a maximum AMOC of 18 Sv (1 Sv = 106 m3 s−1) compared with ∼0 Sv for a simulation without mountains. Atlantic heat transport at 25°N is 1.1 PW with mountains compared to 0.2 PW without. The difference in AMOC is due to major changes in surface heat and freshwater (FW) fluxes over the Atlantic. In the Pacific changed surface fluxes lead to a meridional overturning circulation of 10 Sv. Our results suggest that the effects of mountains on the large‐scale atmospheric circulation is to force the ocean towards a state with a vigorous AMOC and with no overturning in the Pacific.
Atmospheric response to the extreme Arctic sea ice conditions in 2007
Authors: Blüthgen Jonas , Gerdes Rüdiger , Werner Martin
Published: December 2011

An atmospheric general circulation model driven with the observed 2007 extreme Arctic sea surface temperatures and sea ice concentrations responds with higher surface air temperature over northern Siberia and the Eastern Arctic Ocean (+3 K), increased heat uptake of the ocean in summer (+40 W m−2) and increased oceanic heat losses in fall (−60 W m−2) compared to a climatological scenario. A pronounced low sea level pressure anomaly over the Eastern Arctic (−200 Pa) reinforces a sea level pressure dipole over the Arctic that has been observed to become an increasingly important feature of the Arctic atmospheric circulation in summer. The anomalous pressure distribution contributes to sea ice transport from the Eastern Arctic and is likely to reinforce the original sea ice extent anomaly. The results thus support assessments of observational data over recent years that sea ice loss may feed back onto the atmospheric circulation in the northern hemisphere. The resulting late summer / early fall (JAS) atmospheric anomalies are very robust, they appear in virtually all of the 40 realizations of the experiment. However, we find no significant continuation of the atmospheric signal into the winter as has been suggested based on atmospheric observational data.
Retrievals of precipitable water vapor using star photometry: Assessment with Raman lidar and link to sun photometry
Authors: Pérez‐Ramírez D. , Navas‐Guzmán F. , Lyamani H. , Fernández‐Gálvez J. , Olmo F. J. , Alados‐Arboledas L.
Published: December 2011

This work deals with the applicability of a star photometer to retrieve precipitable water vapor (W) at nighttime by means of direct irradiance from stars using a 940 nm narrowband filter. Retrievals are assessed with simultaneous data from a Raman lidar system and linked with daytime values from a sun photometer using measurements taken from March to May 2007 at an urban site. Calibration of both the star and sun photometers was performed by the Modified Astronomical Langley Method. The retrieval of W from photometers is based on a look up table using a simplified expression for the water vapor transmittance and the relative optical water vapor air mass. This methodology presents a systematic uncertainty in W below 3% and 6% for sun and star photometry, respectively. Retrievals of W from star photometry were 9% above those obtained from the Raman lidar technique, but with a great agreement in the temporal evolution from both instruments. The link of daytime and nighttime values of W using sun and star photometers for a more extended database showed a smooth continuity between consecutive periods.
A new technique for spectral analysis of ionospheric TEC fluctuations observed with the Very Large Array VHF system: From QP echoes to MSTIDs
Authors: Helmboldt J. F. , Lazio T. J. W. , Intema H. T. , Dymond K. F.
Published: December 2011

We have used a relatively long, contiguous VHF observation of a bright cosmic radio source (Cygnus A) with the Very Large Array (VLA) through the nighttime, midlatitude ionosphere to demonstrate the phenomena observable with this instrument. In a companion paper, we showed that the VLA can detect fluctuations in total electron content (TEC) with amplitudes of ≤ 10−3 TECU and can measure TEC gradients with a precision of about 2 × 10− 4 TECU km−1. We detail two complementary techniques for producing spectral analysis of these TEC gradient measurements. The first is able to track individual waves with wavelengths of about half the size of the array (∼20 km) or more. This technique was successful in detecting and characterizing many medium‐scale traveling ionospheric disturbances (MSTIDs) seen intermittently throughout the night and has been partially validated using concurrent GPS measurements. Smaller waves are also seen with this technique at nearly all times, many of which move in similar directions as the detected MSTIDs. The second technique allows for the detection and statistical description of the properties of groups of waves moving in similar directions with wavelengths as small as 5 km. Combining the results of both spectral techniques, we found a class of intermediate and small scale waves which are likely the quasi‐periodic (QP) echoes that have been observed to occur within sporadic‐E (Es) layers. We find two distinct populations of these waves. The members of one population are coincident in time with MSTIDs and are consistent with being generated within Es layers by the E–F coupling instability. The other population seems more influenced by the neutral wind, similar to the predominant types of QP echoes found by the Sporadic‐E Experiments over Kyushu (SEEK). We have also found that the spectra of background (i.e., isotropic) fluctuations can be interpreted as the sum of two turbulent components with maximum scales of about 300 km and 10 km.