bluuebunny/crossref_metadata_2025 huggingface dataset:
NIR photoresponse in the mixed phthalocyanine films
Authors: Pakhomov Geogrij , Kuzin Evgenij , Murel Arkadij
Published: July 2006

The structure, optical and conducting properties of thin vacuum deposited films of erbium bisphthalocyanine (Pc2Er) and its mixtures with metal-free phthalocyanine (H2Pc) have been studied with particular reference to the near infrared (NIR). It has been found that, in spite of intense optical absorbance over the UV/Vis/NIR domain, pure Pc2Er films are weakly photoconductive. However, in the mixed Pc2Er/H2Pc films the photocurrent signal was detected in the NIR range of 1200–1500 nm, which is associated with optical activity of Pc2Er molecules.
An Overview of QT Interval Assessment in Safety Pharmacology
Authors: Lacroix Pierre , Picard Sandra
Published: July 2006

Medicinal products that prolong cardiac repolarization unintentionally, as assessed in terms of prolongation of the QT interval of the electrocardiogram, may trigger a potentially fatal arrhythmia called torsade de pointe (TDP). This lethal risk necessitates a detailed preclinical evaluation before initiating clinical trials. There are two different and complementary approaches to assess the potential of drugs to cause QT interval prolongation. The in vivo approach provides information on the potential of the compound to prolong the QT interval under near‐physiological conditions. It is mostly descriptive and not explanatory in terms of mechanisms of action. The in vitro approach provides much more mechanistic information, but is far removed from the clinical situation. While both approaches appear to possess reasonable predictive value, the results may depend largely on the experimental conditions employed. This unit reviews these issues and discusses a strategy aimed at understanding the problems associated with this cardiovascular risk.
Synthesis of Fluorinated Nucleosides
Authors: Katayama Satoshi , Takamatsu Satoshi , Hirose Naoko , Izawa Kunisuke , Maruyama Tokumi
Published: July 2006

Two practical synthetic approaches to the production of lodenosine [FddA, 9‐(2,3‐dideoxy‐2‐fluoro‐β‐D‐threo‐pentofuranosyl)adenine] via 6‐chloropurine riboside or 6‐chloropurine 3′‐deoxyriboside are described. The reaction sequence contains new fluorination methods and new applications of radical reduction. The reagents and reaction conditions of each step have been carefully selected to ensure robustness and safety.
Blood Collection
Authors: Donovan John , Brown Patricia
Published: July 2006

Blood is most frequently sampled for evaluation of serum antibodies or analysis of surface markers on peripheral blood cells. The protocols offered in this unit describe collection of blood from the orbital sinus or plexus of the mouse, rat, or hamster. With appropriate techniques, small amounts of blood can be obtained with little ill effect on the animal. Collection from the auricular vein or artery of the rabbit is also relatively unstressful to the animal. Bleeding procedures that should be performed on the anesthetized animal include collection from the mouse axillary plexus, cardiac puncture of the mouse, rat, hamster, or rabbit, and collection from the hamster abdominal aorta or vena cava.
Characterization and Functional Analysis of Mouse Invariant Natural T (iNKT) Cells
Authors: Bezbradica Jelena S. , Stanic Aleksandar K. , Joyce Sebastian
Published: July 2006

Invariant natural T (iNKT) cells are innate lymphocytes that recognize CD1d‐restricted lipid antigens and have immunoregulatory properties. Human and mouse CD1d‐restricted glycolipid antigen(s) and the iNKT cell functions they elicit are highly conserved, whereby, making the mouse an excellent animal model for understanding iNKT cell biology in vivo. This unit describes basic methods for the characterization and quantification (see ) and functional analysis of murine iNKT cells in vivo or in vitro (see Basic Protocols 2, 3, and 4). This unit also contains protocols that describe enrichment of iNKT cells (see ), generation of CD1d‐tetramer (see ), and lipid antigen loading on cell‐bound (see ) or soluble (see ) CD1d.
Studies of the Ubiquitin Proteasome System
Authors: Lorick Kevin L. , Yang Yili , Jensen Jane P. , Iwai Kazuhiro , Weissman Allan. M.
Published: July 2006

A concept that has arisen over the last decade is that proteins can, in general, be covalently modified by polypeptides, resulting in alterations in their fate and function. The first‐identified and most well studied of these modifying polypeptides is ubiquitin. Although targeting for proteasomal degradation is the best studied outcome of ubiquitylation, we now understand that modification of proteins with ubiquitin has numerous other cellular roles that alter protein function and that are unrelated to proteasomal degradation. Ubiquitylation is a complex process that is regulated at the level of both addition and removal of ubiquitin from target proteins. This unit includes a number of different basic protocols that will facilitate the study of components of the ubiquitin system and substrate ubiquitylation both in vitro and in cells. Because another protein modifier, NEDD8, itself regulates aspects of the ubiquitin system, basic protocols on neddylation are also included in this unit.
Active Site Profiling to Identify Protein Functional Sites in Sequences and Structures Using the Deacon Active Site Profiler (DASP)
Authors: Fetrow Jacquelyn S.
Published: July 2006

Methods for the annotation and analysis of functional sites in proteins are an area of active research, and those methods that allow detailed characterization of functional site features are much needed. A Web site application, DASP, which implements a previously described method (Cammer, et al., 2003) to allow users to create an active site profile for any protein family, is described. Two protocols for functional site analysis of protein families using DASP are presented: 1) creation of functional site signatures and a profile from proteins of known structure and 2) utilization of the active site profile to search sequences that contain fragments similar to those found in the functional site signatures. The active site profile produced by Basic Protocol 1 allows the user to analyze the features of the functional site, i.e., those characteristics that are common across the family and those that are unique to one or several members of the family. The characteristics that are unique to a subfamily might be described as specificity determinants i.e., features that impart specificity to a particular function. Basic Protocol 2 provides instructions for searching for sequences that might contain a similar functional site.
Titelbild: A Ferromagnetically Coupled Mn19 Aggregate with a Record S=83/2 Ground Spin State (Angew. Chem. 30/2006)
Authors: Ako Ayuk M. , Hewitt Ian J. , Mereacre Valeriu , Clérac Rodolphe , Wernsdorfer Wolfgang , Anson Christopher E. , Powell Annie K.
Published: July 2006

Ein königlicher Spin zeichnet ein gemischtvalentes Mn19‐Aggregat aus, das A. K. Powell et al. in ihrer Zuschrift auf S. 5048 ff. vorstellen. Verbrückende Azidoliganden führen zu einem vollständig ferromagnetisch gekoppelten System mit dem Rekord‐Grundzustandsspin 83/2. Das Titelbild zeigt die bemerkenswerte Verbindung vor dem Logo des europäischen Forschungsnetzwerks “MAGMANet”, da sie von drei in diesem Rahmen kooperierenden Arbeitsgruppen gemeinschaftlich untersucht wurde.
Cover Picture: A Ferromagnetically Coupled Mn19 Aggregate with a Record S=83/2 Ground Spin State (Angew. Chem. Int. Ed. 30/2006)
Authors: Ako Ayuk M. , Hewitt Ian J. , Mereacre Valeriu , Clérac Rodolphe , Wernsdorfer Wolfgang , Anson Christopher E. , Powell Annie K.
Published: July 2006

King of the spins is provided by the mixed‐valent Mn19 aggregate as reported by A. K. Powell et al. in their Communication on page 4926 ff. The use of bridging azido ligands leads to a completely ferromagnetically coupled system with a record ground spin state of 83/2. This remarkable molecule has been investigated and characterized by scientists from three laboratories working together in the European Network of Excellence “MAGMANet”, the logo of which provides the background to the cover picture.
Use of FTIR spectroscopy to distinguish between capsular types and capsular quantities in Streptococcus pneumoniae
Authors: Sahu R. K. , Mordechai S. , Pesakhov S. , Dagan R. , Porat N.
Published: July 2006

Fourier transform infrared (FTIR) spectroscopy has shown remarkable ability in distinguishing between bacterial species and identifying bacterial colony structures, when used in tandem with methods such as cluster analysis, principal component analysis, or linear discriminant analysis. The present work was aimed to evaluate the potential of FTIR–microscopy (FTIR‐MSP) to distinguish between different serotypes and capsular quantities of Streptococcus pneumoniae. In general, the results obtained have consistently proven that the spectral information at the region 900–1185 cm−1 was sufficient to distinguish between various pneumococcal serotypes. Moreover, the method was able to differentiate between S. pneumoniae phase variants on the basis of their relative carbohydrate content. The unsupervised cluster analysis of the samples showed differences, not only in the carbohydrate content, but also in the region 1350–1480 cm−1, which is dominated by absorptions due to lipids and phospholipids. This approach proved to be useful for the distinction between S. pneumoniae serotypes and between phase variants, which were shown to acquire different pathogenic capacity. © 2006 Wiley Periodicals, Inc. Biopolymers 83:434–442, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Developing a sustainability accounting framework to inform strategic business decisions: a case study from the chemicals industry
Authors: Taplin James R. D. , Bent David , Aeron‐Thomas David
Published: July 2006

Forum for the Future worked in partnership with a division of a blue‐chip chemicals company (‘ChemCo’), to develop a framework for sustainable business decision‐making. The supply chain impact framework was used to produce a six‐stage analysis that allowed the assessment of ChemCo's operations and products on key stakeholders and contributed to key strategy setting and innovation processes. Of most significance to ChemCo were the final two sustainability accounting stages of this work, which found that the external environmental benefits of one of its products in use (a refrigerant lubricant) were eight times greater than the external environmental costs produced by the entirety of ChemCo's operations. These findings helped inform ChemCo's future economic, social and environmental sustainability strategy, whilst the action of conducting the research fostered greater communication and understanding between different sections of the business, developed new data collection and management processes and helped embed sustainable development objectives throughout the organization. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
Peptabody‐EGF: A novel apoptosis inducer targeting ErbB1 receptor overexpressing cancer cells
Authors: Fattah Omar M. , Cloutier Sylvain M. , Kündig Christoph , Felber Loyse M. , Gygi Christian M. , Jichlinski Patrice , Leisinger Hans‐Jürg , Gauthier Eric R. , Mach Jean Pierre , Deperthes David
Published: July 2006

The epidermal growth factor receptor (EGFR) plays a central role in cell life by controlling processes such as growth or proliferation. This receptor is commonly overexpressed in a number of epithelial malignancies and its upregulation is often associated with an aggressive phenotype of the tumor. Thus, targeting of EGFR represents a very promising challenge in oncology, and antibodies raised against this receptor have been investigated as potential antitumor agents. Various putative mechanisms of action were proposed for such antibodies, including decreased proliferation, induction of apoptosis, stimulation of the immunological response against targeted cancer cells or combinations thereof. We report here the development of an alternative high affinity molecule that is directed against EGFR. Production of this pentameric protein, named peptabody‐EGF, includes expression in a bacterial expression system and subsequent refolding and multimerization of peptabody monomers. The protein complex contains 5 human EGF ligand domains, which confer specific binding towards the extracellular portion of EGFR. Receptor binding of the peptabody‐EGF had a strong antiproliferative effect on different cancer cell lines overexpressing EGFR. However, cells expressing constitutive levels of the target receptor were barely affected. Peptabody‐EGF treated cancer cells exhibited typical characteristics of apoptosis, which was found to be induced within 30 min after the addition of the peptabody‐EGF. In vitro experiments demonstrated a significantly higher binding activity for peptabody‐EGF than for the therapeutic monoclonal EGFR antibody Mab‐425. Furthermore, the antitumor action provoked by the peptabody‐EGF was greatly superior than antibody mediated effects when tested on EGFR overexpressing cancer cell lines. These findings suggest a potential application of this high affinity molecule as a novel tool for anti‐EGFR therapy. © 2006 Wiley‐Liss, Inc.
Telomeres: Prognostic markers for solid tumors
Authors: Bisoffi Marco , Heaphy Christopher M. , Griffith Jeffrey K.
Published: July 2006

Solid tumors continue to affect millions of people worldwide. Increasingly sophisticated diagnostic tools contribute to the high incidence rates for some tumor types, and treatment options continue to expand. However, the progression of solid tumors represents a challenge for the appropriate treatment of individual patients because of the relative inaccuracy of current prognostic markers, including the widely used Tumor‐Nodes‐Metastasis (TNM) staging system, to predict the course of disease. As a result, both over‐ and undertreatment are clinical realities in the management of patients diagnosed with solid tumors. Therefore, population‐based screening programs that increase the overall cancer incidence rates are controversial, as they may do little to improve the patient's quality of life. Consequently, there is a strong need to develop novel and independent markers of prognosis. In this context, we review the use of telomeres as prognostic markers for solid tumors, including cancers from lung, breast, prostate, colon, brain and head and neck. Telomeric sequences, the repetitive DNA at the end of human chromosomes, are mediators of genomic stability and can undergo length alterations during tumor initiation and progression. In a number of studies reviewed here, these alterations, measured as telomere attrition and elongation, have been shown either to be associated with clinical markers of disease progression or to be independent markers of cancer prognosis. We conclude from these studies that careful assessment of telomere length or its proxies, such as telomere DNA content, will be part of novel risk assessment and prognostic modalities for patients with solid tumors. © 2006 Wiley‐Liss, Inc.
Urea bonded cyclodextrin derivatives onto silica for chiral HPLC
Authors: Muderawan I. Wayan , Ong Teng‐Teng , Ng Siu‐Choon
Published: July 2006

Several structurally well‐defined perfunctionalised cyclodextrin chiral stationary phases (CD CSPs) for high performance liquid chromatography have been successfully prepared by immobilisation of perfunctionalised cyclodextrins on silica through urea linkage(s) using the Staudinger reaction. These CSPs show high chiral recognition efficiency and are utilised in the resolution of various types of racemic compounds. This paper reviews the development of sixteen perfunctionalised cyclodextrin‐based CSPs, their preparation, and their application to enantioseparation of seventy‐seven racemic compounds under a range of separation conditions.
Self‐Assembled Fibrillar Networks of Oligo(p‐phenylenevinylene) Based Organogelators
Authors: Praveen Vakayil K. , George Subi J. , Ajayaghosh Ayyappanpillai
Published: July 2006

Self‐assembly induced gelation of a few oligo(p‐phenylenevinylene) (OPV) derivatives in aliphatic hydrocarbon solvents is described. The gelation is the result of hydrogen bond assisted π‐interaction between OPV moieties which facilitate the formation of supramolecular polymeric assemblies, eventually leading to three dimensional fibrillar networks. The number of the aliphatic side chains and the nature of the end functional groups of the OPV backbone play crucial roles in the gelation of hydrocarbon solvents.
Synthesis and Characterization of Novel Hydrophobically End‐Capped Poly(ethylene oxide)s [PEOs]
Authors: Badiger M. V. , Kadam V. S. , Lele A. K. , Wadgaonkar P. P. , Hourdet D.
Published: July 2006

We report on the synthesis and characterization of a novel hydrophobically modified end‐capped poly(ethylene oxide)s. The end‐capping agent of this polymer was designed and synthesised from a renewable resource material namely, gallic acid (i.e. 3,4,5‐trihydroxybenzoic acid), the byproduct of tannin industry. The hydroxyl groups at 3, 4 and 5 positions of gallic acid provide an opportunity for varying the hydrophobicity of the compound. The hydrophobic end‐capping compound, 3,4,5‐tridodecyloxy bezoylazide was prepared from gallic acid and PEGs with different chain lengths (of number average molecular weights, 10000 and 35000 g/mol) were end‐capped using 3,4,5‐tridodecyloxybenzoyl azide. The quantitative analysis of end‐capping in the polymers was demonstrated by 1H‐NMR spectroscopy and the rheological studies were carried out in the surfactant solutions.
Polymeric Multiporous Materials from Fibrillar Networks
Authors: Dasgupta Debarshi , Nandi Arun K.
Published: July 2006

Summary: Poly(vinylidene fluoride) (PVF2) forms thermoreversible gels with liquid alkyl diesters as well as with camphor which is solid at room temperature. The diesters are replaced by another low boiling solvent cyclohexane by solvent exchange technique while camphor is dried just by exposing the material in vacuum to yield highly porous materials. Nano pores are generated as a result of solvent removal from polymer‐solvent intercalates whereas macropores are contributed by percolation of polymer fibrils. The porosity thus created covers a wide range from 3 nm to 400 µm producing multiporous materials. Pores greater than 6 nm are measured by mercury intrusion porosimetry (MIP) and pores of diameter less than 6 nm is observed by N2 adsorption porosimetry. The dried samples show two melting regions, low temperature hump for porous portion and high temperature peak for bulk portion. The porous materials have the ability to absorb water‐soluble herbicides from around 10‐ppm aqueous solution as indicated in UV spectrophotometric experiment.
Effects of substrate geometry on growth cone behavior and axon branching
Authors: Withers Ginger S. , James Conrad D. , Kingman Caroline E. , Craighead Harold G. , Banker Gary A.
Published: July 2006

At the leading edge of a growing axon, the growth cone determines the path the axon takes and also plays a role in the formation of branches, decisions that are regulated by a complex array of chemical signals. Here, we used microfabrication technology to determine whether differences in substrate geometry, independent of changes in substrate chemistry, can modulate growth cone motility and branching, by patterning a polylysine grid of narrow (2 or 5 μm wide) intersecting lines. The shape of the intersections varied from circular nodes 15 μm in diameter to simple crossed lines (nodeless intersections). Time‐lapse recordings of cultured hippocampal neurons showed that simple variations in substrate geometry changed growth cone shape, and altered the rate of growth and the probability of branching. When crossing onto a node intersection the growth cone paused, often for hours, and microtubules appeared to defasciculate. Once beyond the node, filopodia and lamellipodia persisted at that site, sometimes forming a collateral branch. At nodeless intersections, the growth cone passed through with minimal hesitation, often becoming divided into separate areas of motility that led to the growth of separate branches. When several lines intersected at a common point, growth cones sometimes split into several subdivisions, resulting in the emergence of as many as five branches. Such experiments revealed an intrinsic preference for branches to form at angles less than 90°. These data show that simple changes in the geometry of a chemically homogeneous substrate are detected by the growth cone and can regulate axonal growth and the formation of branches. © 2006 Wiley Periodicals, Inc. J Neurobiol 66: 1183–1194, 2006
Understanding the opposition
Authors: Baldwin Thomas
Published: July 2006

Current debates about sex selection start from a paradox: on the one hand, the ‘liberal’ argument in favour of sex selection is often thought to be sound; but on the other hand there is widespread public opposition to sex selection. So it is worth spending some time examining the arguments against sex selection. Four different types of argument are identified: (i) religious arguments; (ii) consequentialist arguments, mainly concerning disturbance to the sex ratio; (iii) arguments to the effect that sex selection involves a failure to respect the autonomy of a child; (iv) arguments to the effect that the motivation for sex selection brings with it an instrumental attitude to children not compatible with a child's need for unconditional acceptance and love.

In the end the conclusion is reached that none of these arguments provide decisive arguments against the liberal thesis that sex selection ought to be permitted, especially where 'family balancing' is envisaged. In the light of this conclusion the issue of fetal sexing followed by selective feticide as a method of sex selection is discussed. It is argued that sex selection is not in general a good reason for abortion, but that this practice may become unstoppable. Copyright © 2006 John Wiley & Sons, Ltd.
Non‐invasive diagnosis of fetal sex; utilisation of free fetal DNA in maternal plasma and ultrasound
Authors: Avent Neil D. , Chitty Lyn S.
Published: July 2006

Non‐invasive prenatal diagnosis is now a clinical reality, using both early ultrasound and molecular DNA methods. Technical advances in the sensitivity of the polymerase chain reaction (PCR), coupled with the finding that significant levels of fetal DNA (ffDNA) are found in maternal plasma and serum, has enabled the ready detection of paternally inherited genes or polymorphisms. Routine maternal plasma‐based genotyping is now available for the determination of fetal sex andRHDblood group status (Van der Schootet al., 2003). This review touches briefly on the ultrasound diagnoses and then focuses on the application of free ffDNA for fetal sex determination, indicating the Y‐chromosome targets exploited in this strategy and the merits of their utilisation. Copyright © 2006 John Wiley & Sons, Ltd.
Ice Ages and the Thermal Equilibrium of the Earth, II
Authors: Adam David P.
Published: July 2006

The energy required to sustain midlatitude continental glaciations comes from solar radiation absorbed by the oceans. It is made available through changes in relative amounts of energy lost from the sea surface as net outgoing infrared radiation, sensible heat loss, and latent heat loss. Ice sheets form in response to the initial occurrence of a large perennial snowfield in the subarctic. When such a snowfield forms, it undergoes a drastic reduction in absorbed solar energy because of its high albedo. When the absorbed solar energy cannot supply local infrared radiation losses, the snowfield cools, thus increasing the energy gradient between itself and external, warmer areas that can act as energy sources. Cooling of the snowfield progresses until the energy gradients between the snowfield and external heat sources are sufficient to bring in enough (latent plus sensible) energy to balance the energy budget over the snowfield. Much of the energy is imported as latent heat. The snow that falls and nourishes the ice sheet is a by-product of the process used to satisfy the energy balance requirements of the snowfield. The oceans are the primary energy source for the ice sheet because only the ocean can supply large amounts of latent heat. At first, some of the energy extracted by the ice sheet from the ocean is stored heat, so the ocean cools. As it cools, less energy is lost as net outgoing infrared radiation, and the energy thus saved is then available to augment evaporation. The ratio between sensible and latent heat lost by the ocean is the Bowen ratio; it depends in part on the sea surface temperature. As the sea surface temperature falls during a glaciation, the Bowen ratio increases, until most of the available energy leaves the oceans as sensible, rather than latent heat. The ice sheet starves, and an interglacial period begins. The oscillations between stadial and interstadial intervals within a glaciation are caused by the effects of varying amounts of glacial meltwater entering the oceans as a surface layer that acts to reduce the amount of energy available for glacial nourishment. This causes the ice sheet to melt back, which continues the supply of meltwater until the ice sheet diminishes to a size consistent with the reduced rate of nourishment. The meltwater supply then decreases, the rate of nourishment increases, and a new stadial begins.
Climate Versus Changes in 13C Content of the Organic Component of Lake Sediments During the Late Quarternary
Authors: Stuiver Minze
Published: July 2006

Several factors influence the long-term 13C record of the organic component in lake sediments. Two of the more predominant ones are changes in hardness of the water and changes in organic productivity. In general, during colder climatic episodes, 13C values are lower. Of 12 lakes studied, 4 have 13C records with large changes in 13C content that are to a certain degree correlative with climatic changes.
A Solution for the Northern Hemisphere Climatic Zonation During a Glacial Maximum
Authors: Saltzman Barry , Vernekar Anandu D.
Published: July 2006

The same model previously used to deduce an acceptable first order picture of the present zonally averaged macroclimate is now solved for the climatic response to the “glacial” surface boundary conditions that prevailed at 18,000 BP in the northern hemisphere. The equilibrium solution obtained gives the distributions with latitude of the mean temperature, wind, humidity, precipitation, evaporation, heat balance, transient baroclinic eddy statistics (i.e., kinetic energy of the meridional wind and meridional flux of heat, momentum, and water vapor), and the energy integrals. In general terms, the solution shows the glacial atmosphere to be colder and drier than at present, with an intensified polar front, stronger mean zonal and poloidal winds, more intense transient baroclinic eddies (storms) transporting heat, momentum and water vapor poleward at higher rates, and reduced precipitation and evaporation. Also evident is an equatorward shift of the climatic zones (as delineated by the mean surface zonal winds, the poloidal motion, and the difference between mean evaporation and precipitation), particularly in higher latitudes. Other properties of the solution, such as the effect of zonal wind changes on the length of the day, are discussed.
Holocene Soils and Soil-Geomorphic Relations in an Arid Region of Southern New Mexico
Authors: Gile Leland H.
Published: July 2006

A study area in an arid region of southern New Mexico is in basin-and-range topography and includes both a river valley and a closed basin. Holocene soils occur in valley fills and low terraces between Pleistocene fans, in and near drainageways on the fan-piedmont, on ridges, and in dunes. Holocene soils suggest the character of initial development in soils that are much older and more complex, and record the beginnings of various soil horizons. Noncalcareous brown or reddish brown B horizons have formed in low-carbonate parent materials of stable sites. Incipient development of the argillic horizon and the Haplargids occurs at stable sites in very gravelly materials that are about 1–2000 yr old. The cambic horizon and Camborthids occur in adjacent low-gravel materials of the same age. The argillic horizon occurs continuously in soils of earliest Holocene, particularly in very gravelly materials. Where soils have been truncated, as in areas affected by landscape dissection, argillic and cambic horizons are usually absent and the soils are Torripsamments, Torriorthents, or Torrifluvents depending on content of sand, gravel, and organic carbon. In high-carbonate parent materials, noncalcareous, reddish brown B horizons have not formed at any time in the Holocene. Most of these soils are Torriorthents or Torrifluvents although an incipient calcic horizon has formed in some of the oldest Holocene soils; the latter are Calciorthids. Horizons of carbonate accumulation are the best and most common pedogenic indicators of soil age. Stage I carbonate horizons are a major feature of pedogenesis in the Holocene. Because of additions of carbonate from the atmosphere, carbonate horizons are morphologically similar whether they have formed in high or low-carbonate alluvium. The carbonate accumulations are illuvial.

Some Holocene deposits apparently resulted from changes in climate. Others, such as the youthful deposits of coppice dunes, apparently were caused by man's introduction of cattle and subsequent overgrazing and seed dispersal.
Nondeterministic Theories of Climatic Change
Authors: Lorenz Edward N.
Published: July 2006

A basic assumption in some climatic theories is that, given the physical properties of the atmosphere and the underlying ocean and land, specified environmental parameters (amount of solar heating, etc.) would determine a unique climate and that climatic changes therefore result from changes in the environment. The possibility that no such unique climate exists and that nondeterministic factors are wholly or partly responsible for long-period fluctuations of the atmosphere-ocean-earth system, is considered. A simple difference equation is used to illustrate the phenomena of transitivity, intransitivity, and almost-intransitivity. Numerical models of moderate size suggest that almost-intransitivity might lead to persistence of atmospheric anomalies for a whole season. The effect of this persistence could be to allow substantial anomalies to build up in the underlying ocean or land, perhaps as abnormal temperatures or excessive snow or ice. These anomalies could subsequently influence the atmosphere, leading to long-period fluctuations. The implications of this possibility for the numerical modeling of climate, and for the interpretation of the output of numerical models, are discussed.
Peopling of the Americas
Authors: Rouse Irving
Published: July 2006

Study of the prehistory of an Americas has proceeded through successive cycles, in which archaeologists have assumed or postulated hypotheses of migration and development, have searched for evidence with which to test these hypotheses, and have abandoned them when the evidence proved to be contradictory. We are completing the current cycle and must seek new hypotheses that better fit our present evidence.

The available data are reviewed to show the inaccuracy of the current hypotheses and to develop new ones. It is suggested that the first Indians arrived during a Lower Lithic age, marked by the manufacture of irregular flakes, trimmed only on their edges. This age may have started as early as 30,000 BP.

South of the Laurentide ice sheet, the Lower Lithic age began to give way about 14,000 BP to a Middle Lithic Age. This was marked by a variety of types of bifacially chipped projectile points which seem to have developed locally: Folsomoid points in Anglo-America, Joboid points in the Circum-Caribbean region, and Magelloid points in western and southern South America.

North of the ice sheet, the place of the Middle Lithic age was taken by an Upper Lithic age, marked by microblades of Asiatic origin. These appear to have reached the Bering Strait region about 14,000 BP. The dichotomy between the Middle and Upper Lithic ages lasted until the retreat of the ice ca. 8000 BP.
Palynological Studies in the Western Arm of Lake Superior
Authors: Maher Louis J.
Published: July 2006

Lake Superior sediments contain pollen whose changes through time can be correlated with dated pollen diagrams from small lakes in the region. A core collected in 1972 from the deep trough (265 m) off Silver Bay (47° 09′N, 91°20′W) penetrated 6.25 cm of taconite tailings, 55 cm of postglacial silty clay, and 93.5 cm of late-glacial varves. Seven levels in the core were dated by stratigraphic and palynological techniques. The varves stopped forming about 9000 years ago, probably when glacial ice retreated to the north shore. The last 100 varves accumulated at about 10 mm/yr, but the average net sedimentation rate subsequently slowed to 0.05 mm/yr until the time of settlement about 1890. The sedimentation rate then increased by a factor of 10, to 0.5 mm/yr until 1956 when taconite processing began. The postsettlement interval can be recognized by marked increases of ragweed and chenopod pollen that result from land disturbance caused by forest clearance and agriculture. The postsettlement interval is also present at the top of six cores from four other sites in western Lake Superior, collected in water from 25–140 m deep. The postsettlement sedimentation rate varies from 0.1–0.8 mm/yr, suggesting that man has greatly increased sediment yield to the lake in the last 80 years.
Late-Wisconsin Marine Environments of the Champlain Valley (New York, Quebec)
Authors: Cronin Thomas M.
Published: July 2006

The Champlain Sea occupied the Champlain Valley from about 12,500 to 10,000 yr BP. Following an initial maximum limit of inundation, isostatic crustal rebound caused the sea's gradual regression, which is documented by the parallel alignment of tilted shoreline features at successively low elevations along a north-south profile. Two new radiocarbon shell dates, 11,665 ± 175 (QC 200), elevation 95 m, and 10,300 ± 180 (QC 199), elevation 47 m, date early and late Champlain Sea deposits, respectively. From the elevation (ASL) and invertebrate fauna of littoral deposits, three environmentally distinct phases of the sea were recognized. Early Champlain Sea Transitional phase deposits at high elevations are characterized by a mixed association of fresh and euryhaline marine ostracodes. Frigid-subfrigid climates and fluctuating salinities of this period possibly reflect intermixing of the fresh waters of Lake Vermont with incoming marine waters.Hiatella arcticaphase faunas indicate similar climatic conditions but significantly higher salinities (polyhaline). Deposits from the final phase of the sea, theMya arenariaphase, were found at low elevations just above the present level of Lake Champlain. A predominantly cold-temperate, mesohaline fauna characterizes this period. The influences of Lake Algonquin drainage, warm Gulf Stream water and perhaps the retreating Laurentide Ice Sheet are discussed as possible causes for the observed faunal and environmental changes.
The California Ice-Age Refugium and the Rancholabrean Extinction Problem
Authors: Johnson Donald Lee
Published: July 2006

The question of what caused the late Quaternary extinction of the Rancholabrean fauna in the California glacial refugium is examined. In the absence of significant climatic and other natural environmental change, man was probably the principal agent of extinction in California. This extinction event marked the beginning of a long history of environmental impact in the area by humans.
The Late Quaternary Climate of Coastal California: Evidence for an Ice Age Refugium
Authors: Johnson Donald Lee
Published: July 2006

The present Mediterranean climate of coastal California is unique in North America and reflects the interaction of several important synoptic controls, principally the North Pacific semipermanent anticyclone, and to a lesser extent the Aleutian low-pressure system and the cool California oceanic current. These synoptic climatic controls, key parts of the global air-sea circulation, were probably operative throughout late Quaternary time as shown by paleoecologic evidence. The thick accumulations of sediments in basins of offshore California indicate that while variable sedimentation regimes reflect changing climatic and oceanographic conditions, the Quaternary climate was probably semiarid as now, even during glacial maxima. Late Quaternary coastal dunes preserve former wind directions and show that prevailing late Quaternary winds were directionally equivalent to modern winds, which are controlled by the North Pacific anticyclone and by interactions between the North Pacific high and the interior basin low. These sand dunes contain buried, datable, carbonate-rich soils. Precipitation then, like the present rainfall regime, was not enough to leach the carbonates from the soils. Charcoal in buried dunes and soils shows that fire was environmentally important throughout the Quaternary, just as it is today. Fossil plants indicate that sclerophyllous vegetation and forest stands of conifers, adapted to a Mediterranean climate, were widely distributed during late Quaternary time. Fossil pollen in the Sierra Nevada indicates the influence of the North Pacific high. The historical precipitation record overlaps a late Holocene tree-ring record permitting extrapolation of the precipitation curve back nearly 600 years. Well-defined wet and dry trends in the precipitation pattern characterized this time span, and provide a possible analog to the earlier Holocene and Pleistocene precipitation regime. The paleoecologic record shows that the late Quaternary climate of coastal California was characterized by regimes similar to those prevailing today. The persistence of a Mediterranean climate in California during the last glaciation contrasts with dramatic climatic changes experienced in glaciated parts of North America. California thus was an Ice Age refugium for animals and cold-sensitive plants.
Extent of the Late-Wisconsin Glaciation in Northwest Greenland and Northern Ellesmere Island: A Review of the Glaciological and Geological Evidence
Authors: Paterson W.S.B.
Published: July 2006

In the Camp Century core, the difference in oxygen isotope ratio between Wisconsin and Holocene ice seems too large to be purely a climatic effect. A more likely interpretation is that the Wisconsin ice originated at an elevation of at least 500 m above the present station. Total gas content measurements on the core suggest that the elevation difference was about 1300 m. These results are inconsistent with the present ice flow pattern. Three hypotheses are considered: (1) The Wisconsin ice originated near the crest of a high ridge connecting the Greenland ice sheet with an ice sheet on Ellesmere Island. (2) The Wisconsin flow pattern was similar to the present one but ice was much thicker and the ice margin considerably in advance of its present position. (3) The Wisconsin ice originated near the main Greenland ice divide whereas the Holocene ice originates within 50 km of the station. Glacial-geological data are sparse but do not appear to support the first hypothesis, while the uplift data have been interpreted in two widely different ways. The second hypothesis might explain the oxygen isotope values but not the gas content measurements. The third hypothesis is thus considered the most likely one. Differences between Wisconsin and Holocene flow patterns might result from changes in positions of the ice margins as a consequence of lowered sea level in the Wisconsin.
Pollen Analysis of Fossil Packrat Middens from the Sonoran Desert
Authors: King James E. , Van Devender Thomas R.
Published: July 2006

Pollen contained in 22 fossil packrat middens from the Sonoran Desert provides a complementary, but differing, view of the paleoenvironment from that derived by analysis of the associated plant macrofossils. The regional component of the pollen data is in sharp contrast to the locally oriented macrofossils. A total of 84 macrofossil taxa and 47 pollen taxa were identified; only 18 taxa were common to both. The low Index of Similarity, 0.4, indicates that the two sources of fossil information are providing different sets of paleobotanical data. When combined with plant macrofossils and good radiocarbon dating control, the pollen spectra derived from fossil middens are compatable with other paleoenvironmental sequences.
Quaternary of Chile: The State of Research
Authors: Paskoff Roland P.
Published: July 2006

The aim of this paper is to present a summary of current knowledge about Quaternary climatic changes, sea level fluctuations, tectonic deformation, and volcanic activity in Chile. In the Andean highlands of the hyperarid desert, glaciers and lakes fluctuated repeatedly. Evidence of pluvial periods is not well documented in the marginal desert. On the contrary, pronounced climatic changes are recorded in semiarid Chile. In central Chile two or three major glacial advances have been identified, but they remained confined within the high Cordillera. In the longitudinal valley of the Lake Region geomorphic remnants of four glaciations have been described;14C dates are available for the last glaciation. The glacial history of the Fjord Region is still obscure. Whether Pleistocene climatic changes in the northern and southern part of Chile were synchronous or not is a problem which requires further investigation. Sea level fluctuations along the Chilean coast are in part ascribed to glacio-eustatic effects. They left striking sets of step-like marine terraces in northern and central Chile. From a paleontologic point of view the Pleistocene corresponds to a pronounced move toward isolation and endemic development of the marine fauna. The Quaternary tectonic tendency seems to be toward extension and not compression expected as sea-floor spreading compensation. Normal faults limiting uplifted, downwarped, and tilted blocks are common. Folds are rarely found. Northern Chile is characterized by an imposing chain of about 600 stratovolcanoes. They rest on Tertiary ignimbrites which cover thealtiplano. Quartz-bearing latite-andesites are predominant. Present volcanic activity is sporadic and weak. South of a conspicuous gap between 27 and 33°S, Quaternary volcanism reappears in the high Cordillera, and many volcanoes have erupted violently within historic times. Rocks are fundamentally andesite or basaltic andesite. Poorly sorted ashes including pumice clasts in the Central Valley south of Santiago are interpreted as volcanic mudflows of late Pleistocene age.
Glacier Peak Tephra in the North Cascade Range, Washington: Stratigraphy, Distribution, and Relationship to Late-Glacial Events
Authors: Porter Stephen C.
Published: July 2006

Pumiceous tephra, resulting from multiple eruptions of Glacier Peak volcano in late-glacial time, mantles much of the landscape in the eastern North Cascade Range and extends eastward beyond the Columbia River as a thinner discontinuous deposit. Within about 25 km of the source, the tephra is divisible into as many as nine layers, distinguishable in the field on the basis of color, grain size, thickness, and stratigraphic position. Three principal layers, designated G (oldest), M, and B, are separated from one another by thinner, finer layers. Layer G has been found as far east as Montana and southern Alberta, whereas layer B has been identified as far as western Wyoming. By contrast, layer M trends nearly south, paralleling the crest of the Cascade Range. Available 14C dates indicate that the tephra complex was probably deposited between about 12,750 and 11,250 years ago. Glacier Peak tephra overlies moraines and associated outwash east of the Cascade Crest that were deposited about 14,000 years ago. Unreworked tephra occurs within several kilometers of many valley heads implying that major valley glaciers had nearly disappeared by the time of the initial tephra fall. Distribution of tephra indicates that the southern margin of the Cordilleran Ice Sheet had retreated at least 80 km north of its terminal moraine on the Waterville Plateau by the time layer G was deposited. Late-glacial moraines of the Rat Creek advance lie within the fallout area of layer M but lack the tephra on their surface implying that they were built subsequent to the eruption of this unit. Moraines of the Hyak advance at Snoqualmie Pass, which are correlated with the Rat Creek moraines farther north, were constructed prior to 11,000 14C years ago. The late-glacial advance along the Cascade Crest, therefore, apparently culminated between about 12,000 and 11,000 14C years ago and was broadly in phase with the Sumas readvance of the Cordilleran Ice Sheet in the Fraser Lowland which occurred between about 11,800 and 11,400 14C years ago.
Late Cenozoic Paleoclimates of the Gaap Escarpment, Kalahari margin, South Africa
Authors: Butzer K.W. , Stuckenrath R. , Bruzewicz A.J. , Helgren D.M.
Published: July 2006

The Gaap Escarpment is a dolomite cuesta demarcating the southeast margin of the Kalahari. Since Miocene-Pliocene times, thick masses of lime tufa have repeatedly accumulated at several points along this escarpment, and four regional sequences are described. These allow discrimination of six major depositional complexes, commonly characterized by basal cryoclastic breccias or coarse conglomerates that reflect frost shattering and torrential runoff, followed by sheets and lobes of tufa generated in an environment substantially wetter than today. A chronostratigraphy for the last 30,000 yr is provided by14C dating, with direct or indirect correlations to the Vaal River sequence. The regional stratigraphy as well as faunal dating indicate an early Pleistocene age forAustralopithecus africanusat Taung. Repeated episodes of protracted cold or wetter climate or both begin in terminal Miocene times, and the last Pleistocene cold-moist interval began after 35,000 yr B.P. and ended 14,000 yr B.P. Early and late Holocene times were mainly wetter, whereas the middle Holocene was drier than today. The paleoclimatic sequence differs from that of the southern and southwestern Cape or that of East Africa, but close parallels are evident throughout the lower Vaal Basin and the southern Kalahari. The tufa cycles provide a unique, 5,000,000-yr record of climatic variation in the Kalahari summer-rainfall belt that can be related to complex anomalies of the general atmospheric circulation.
Human Skeletal Remains from the Southern Cape Province and Their Bearing on the Stone Age Prehistory of South Africa
Authors: Rightmire G. P.
Published: July 2006

Substantial numbers of human skeletons have been recovered from caves and shelters of the southern Cape Province, South Africa, and these constitute a valuable source of information about evolutionary change and population movement during Upper Pleistocene and Holocene times. A few fragments from Klasies River Mouth and Die Kelders are firmly associated with Middle Stone Age cultural assemblages, but most of the material is probably linked with the Later Stone Age Albany and Wilton industries. Unfortunately the largest collections of relatively well-preserved remains have come from earlier excavations (Matjes River Shelter, Oakhurst), and the stratigraphic provenance of these burials is frequently in doubt. Other skeletal samples are small, and paleodemographic approaches are diffcult to apply. However, Bushman- or Hottentot-like individuals can certainly be identified, and this is important to the questions of Bushman antiquity or origins. Other problems concerning early Cape populations can also be examined, and this work on the human skeletons should complement ongoing cave sediment and other geological studies, faunal and plant analyses, and archaeological investigations of associated cultural remains.