bluuebunny/crossref_metadata_2025 huggingface dataset:
Regucalcin stimulates osteoclast‐like cell formation in mouse marrow cultures
Authors: Yamaguchi Masayoshi , Uchiyama Satoshi
Published: December 2004

The effect of regucalcin, a regulatory protein in intracellular signaling, on osteoclastic cell formation in mouse bone marrow culture is investigated. The bone marrow cells were cultured for 7 days in an α‐minimal essential medium containing either vehicle or regucalcin (10−10–10−8M). Osteoclast‐like cell formation was estimated by staining for tartrate‐resistant acid phosphatase (TRACP), a marker enzyme of osteoclasts. The presence of regucalcin (10−10–10−8M) caused a remarkable increase in osteoclast‐like multinucleated cells (MNCs). The effect of regucalcin in stimulating osteoclast‐like cell formation was significantly inhibited in the presence of calcitonin (CT; 10−9M), 17β‐estradiol (10−9M), β‐cryptoxanthin (CX; 10−6M), or zinc sulfate (10−4M), which is an anti‐bone resorbing factor. The effect of regucalcin on osteoclast‐like cell formation was not significantly blocked in the presence of cycloheximide, an inhibitor of protein synthesis, or 5,6‐dichloro‐1‐β‐D‐ribofuranosylbenzimidazole (DRB), an inhibitor of transcriptional activity. The effect of parathyroid hormone (10−7M), 1,25‐dihydroxyvitamin D3 (10−7M), prostaglandin E2 (10−5M), or tumor necrosis factor‐α (10 ng/ml) in increasing osteoclast‐like cell formation was significantly enhanced in the presence of regucalcin (10−8M). Moreover, when rat femoral‐diaphyseal or ‐metaphyseal tissues were cultured for 48 h in the presence of regucalcin (10−10–10−8M), the diaphyseal or metaphyseal calcium content was significantly decreased in the presence of regucalcin (10−10–10−8M) in vitro. The consumption of glucose and the production of lactic acid in culture medium by the diaphyseal or metaphyseal tissues was significantly raised in the presence of regucalcin (10−10–10−8M). This study demonstrates that regucalcin directly stimulates osteoclast‐like cell formation in mouse marrow culture in vitro, and that the protein stimulates bone resorption in rat femoral tissues in vitro. © 2004 Wiley‐Liss, Inc.
Quaternized biomass as an anion exchanger for the removal of nitrate and other anions from water
Authors: Namasivayam Chinnaiya , Höll Wolfgang H
Published: December 2004

Dried Chinese Reed (Miscanthus sinensis), a fast growing plant, was used as a model biomass for the development of anion exchangers using a quaternization agent, N‐(3‐chloro‐2‐hydroxypropyl)trimethylammonium chloride (CHMAC), and a cross‐linking agent, epichlorohydrin. Anions studied include nitrate, phosphate, perchlorate and sulfate. Batch mode adsorption studies were conducted using aqueous solutions of anions. Detailed kinetics were studied for nitrate removal. Parameters studied included anion concentration, agitation time, adsorbent dose, and pH. Adsorption equilibrium occurred in 10 min for all the anions studied. Equilibrium adsorption data followed both Langmuir and Freundlich isotherms. The presence of phosphate, perchlorate, fluoride and sulfate lowered the adsorption significantly. The effects of pH on adsorption and desorption show that ion exchange is involved in the adsorption process. The adsorption capacity of the cross‐linked and quaternized Chinese Reed for nitrate, sulfate, phosphate and perchlorate was found to be 7.55, 13.25, 16.61 and 10.07 mg of anion per g of the anion exchanger, respectively. Copyright © 2004 Society of Chemical Industry
Brain glucose concentrations in patients with type 1 diabetes and hypoglycemia unawareness
Authors: Criego Amy B. , Tkac Ivan , Kumar Anjali , Thomas William , Gruetter Rolf , Seaquist Elizabeth R.
Published: December 2004

Although it is well established that recurrent hypoglycemia leads to hypoglycemia unawareness, the mechanisms responsible for this are unknown. One hypothesis is that recurrent hypoglycemia alters brain glucose transport or metabolism. We measured steady‐state brain glucose concentrations during a glucose clamp to determine whether subjects with type 1 diabetes and hypoglycemia unawareness may have altered cerebral glucose transport or metabolism after exposure to recurrent hypoglycemia. We compared 14 subjects with diabetes and hypoglycemia unawareness to 27 healthy control subjects. Brain glucose concentrations were measured under similar metabolic conditions using in vivo 1H nuclear magnetic resonance (NMR) spectroscopy at 4 Tesla during a hyperglycemic clamp (plasma glucose = 16.7 mmol/l) with somatostatin and insulin. Subjects with type 1 diabetes and hypoglycemia unawareness had significantly higher brain glucose concentrations compared to that in controls under the same conditions (5.5 ± 0.3 vs. 4.7 ± 0.1 μmol/g wet weight, P = 0.016). These data suggest that changes in brain glucose transport or metabolism may occur as a result of recurrent hypoglycemia. © 2004 Wiley‐Liss, Inc.
Astrocyte glycogen metabolism is required for neural activity during aglycemia or intense stimulation in mouse white matter
Authors: Brown Angus M. , Sickmann Helle M. , Fosgerau Keld , Lund Trine M. , Schousboe Arne , Waagepetersen Helle S. , Ransom Bruce R.
Published: December 2004

We tested the hypothesis that inhibiting glycogen degradation accelerates compound action potential (CAP) failure in mouse optic nerve (MON) during aglycemia or high‐intensity stimulation. Axon function was assessed as the evoked CAP, and glycogen content was measured biochemically. Isofagomine, a novel inhibitor of central nervous system (CNS) glycogen phosphorylase, significantly increased glycogen content under normoglycemic conditions. When MONs were bathed in artificial cerebrospinal fluid (aCSF) containing 10 mM glucose, the CAP failed 16 min after exposure to glucose‐free aCSF. MONs bathed in aCSF plus isofagomine displayed accelerated CAP failure on glucose removal. Similar results were obtained in MONs bathed in 30 mM glucose, which increased baseline glycogen concentration. The ability of isofagomine to increase glycogen content thus was not translated into delayed CAP failure. This is likely due to the inability of the tissue to metabolize glycogen in the presence of isofagomine, highlighting the importance of glycogen in sustaining neural function during aglycemia. The hypothesis that glycogen breakdown supports intense neural activity was tested by blocking glycogen breakdown during periods of high‐frequency stimulation. The CAP area declined more rapidly when glycogen metabolism was inhibited by isofagomine, explicitly showing an important physiological role for glycogen metabolism during neural activity. © 2004 Wiley‐Liss, Inc.
The assessment of behavioural activation—the relationship between positive emotionality and the behavioural activation system
Authors: Quilty Lena C. , Oakman Jonathan M.
Published: December 2004

Much personality research suggests that the variance in personality can be accounted for by a few dimensions, often hypothesized to be connected to neurological circuits. Gray's (1982) behavioural activation system (BAS) and behavioural inhibition system (BIS) in particular propose to explain for a variety of behaviour. This investigation sought to determine whether Positive Emotionality is an appropriate measure of the BAS, and how Tellegen's (1985) constructs are related to BAS activity. Measures of BAS and Positive Emotionality were administered to undergraduates. Confirmatory factor analyses revealed that, while Positive Emotionality can be used as an indicator of BAS activity, it is better conceived of as a distinct, correlated construct. In addition, not all components of Positive Emotionality were related to BAS activity, and BAS was further related to components of Negative Emotionality and Constraint. Copyright © 2004 John Wiley & Sons, Ltd.
Aryl acrylate based high‐internal‐phase emulsions as precursors for reactive monolithic polymer supports
Authors: Krajnc Peter , Štefanec Dejan , Brown Jane F. , Cameron Neil R.
Published: December 2004

Water‐in‐oil high‐internal‐phase emulsions (HIPEs), containing 4‐nitrophenyl acrylate and 2,4,6‐trichlorophenyl acrylate as reactive monomers, were prepared and polymerized, and highly porous monolithic materials resulted. The novel materials were studied by combustion analysis, Fourier transform infrared spectroscopy scanning electron microscopy, mercury porosimetry, and N2 adsorption/desorption analysis. With both esters, cellular macroporous monolithic polymers were obtained; the use of 4‐nitrophenyl acrylate resulted in a cellular material with void diameters between 3 and 7 μm and approximately 3‐μm interconnects, whereas the use of 2,4,6‐trichlorophenyl acrylate yielded a foam with void diameters between 2 and 5 μm, most interconnects being around 1 μm. The resulting monoliths proved to be very reactive toward nucleophiles, and possibilities of functionalizing the novel polymer supports were demonstrated via reactions with amines bearing additional functional groups and via the synthesis of an acid chloride derivative. Tris(hydroxymethyl)aminomethane and tris(2‐aminoethyl)amine derivatives were obtained. The hydrolysis of 4‐nitrophenylacrylate removed the nitrophenyl group, yielding a monolithic acrylic acid polymer. Furthermore, functionalization to immobilized acid chloride was performed very efficiently, with more than 95% of the acid groups reacting. The measurement of the nitrogen content in 4‐nitrophenyl acrylate poly(HIPE)s after various times of hydrolysis showed the influence of the total pore volume of the monolithic polymers on the velocity of the reaction, which was faster with the more porous polymer. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 296–303, 2005
Chemical synthesis of biodegradable aliphatic polyesters and polycarbonates catalyzed by novel versatile aluminum metal complexes bearing salen ligands
Authors: Yang Jing , Yu Yihua , Li Qiaobo , Li Yang , Cao Amin
Published: December 2004

Two novel aluminum metal complexes (2 and 3) bearing salen ligands were in situ prepared from trimethyl aluminum (AlMe3), methanol, and (R,R)‐N,N′‐bis(salicylidene)‐1,2‐diaminocyclohexane with original synthetic strategies, and a preliminarily resoluted (R,R)‐1,2‐diaminocyclohexane was applied as a synthetic precursor. By means of Fourier transform infrared spectrometry, NMR spectrometry, mass spectrometry, and single‐crystal X‐ray diffractometry, 2 and 3 were revealed to be distinct molecular structures with corresponding yields of 85 and 10%, respectively. Further studies via 27Al NMR techniques and single‐crystal X‐ray diffraction indicated that dimeric metal complex 3 appeared in the six‐coordinated state, whereas there was a dynamic equilibrium transition between the five‐ and six‐coordinated states for metal complex 2 in a CDCl3 solution. The more stable dimeric metal complex (3) exhibited two inequivalent aluminum metal centers coordinated to nitrogen atoms attributed to two different salen ligands, and this was different from the reported salen aluminum complex structures. Furthermore, 2 and 3 were employed as candidate catalysts for the ring‐opening polymerization (ROP) of some important biodegradable aliphatic polyesters and polycarbonates, including poly(ϵ‐caprolactone) (PCL), poly(δ‐valerolactone), poly(trimethylene carbonate), and poly(2,2‐dimethyl trimethylene carbonate). The synthetic results indicated that both metal complexes efficiently catalyzed ROP at 100 °C in an anisole solution, and 3 showed much better controlled characteristics of ROP than 2. Very narrow molecular weight distributions close to 1.21 for PCL were detected with 3 as the ROP catalyst. In addition, a catalytic mechanism study confirmed that ROP catalyzed by these metal complexes was in good agreement with the commonly accepted coordination polymerization reported for aluminum triiso [Al(OiPr)3] and stannous octanoate [Sn(Oct)2]. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 373–384, 2005
Sample size recalculation for binary data in internal pilot study designs
Authors: Friede Tim , Kieser Meinhard
Published: December 2004

For binary endpoints, the required sample size depends not only on the known values of significance level, power and clinically relevant difference but also on the overall event rate. However, the overall event rate may vary considerably between studies and, as a consequence, the assumptions made in the planning phase on this nuisance parameter are to a great extent uncertain. The internal pilot study design is an appealing strategy to deal with this problem. Here, the overall event probability is estimated during the ongoing trial based on the pooled data of both treatment groups and, if necessary, the sample size is adjusted accordingly. From a regulatory viewpoint, besides preserving blindness it is required that eventual consequences for the Type I error rate should be explained. We present analytical computations of the actual Type I error rate for the internal pilot study design with binary endpoints and compare them with the actual level of the chi‐square test for the fixed sample size design. A method is given that permits control of the specified significance level for the chi‐square test under blinded sample size recalculation. Furthermore, the properties of the procedure with respect to power and expected sample size are assessed. Throughout the paper, both the situation of equal sample size per group and unequal allocation ratio are considered. The method is illustrated with application to a clinical trial in depression. Copyright © 2004 John Wiley & Sons Ltd.
Using entertainment media to inform student affairs teaching and practice about multiculturalism
Authors: Howard‐Hamilton Mary F. , Hinton Kandace G.
Published: December 2004

This chapter discusses the importance of enhancing the diversity awareness and multicultural competence of undergraduate and graduate students through the use
of popular media for classes and training workshops, and it presents two models that explain behaviors associated with racial identity development and understanding diversity issues.
Using entertainment media to inform student affairs teaching and practice related to sexual orientation
Authors: Cawthon Tony W.
Published: December 2004

This chapter presents theoretical foundations, resources, and entertainment media applications for working with lesbian, gay, bisexual, and transgender (LGBT) undergraduate and graduate students.
Using entertainment media to inform student affairs teaching and practice related to sex and gender
Authors: Davis Tracy L.
Published: December 2004

This chapter presents several strategies for teaching about sex and gender using entertainment media and explores critical issues related to content development, the delivery process, and evaluation methods.
Using entertainment media to inform student affairs teaching and practice related to leadership
Authors: McMahon Timothy R. , Bramhall Ron
Published: December 2004

This chapter provides a simple and effective model for using film, television and other popular media in student leadership development activities.
Using entertainment media to inform student affairs teaching and practice related to career development
Authors: Dagley John C. , Paisley Pamela O.
Published: December 2004

Books, music, films and other media sources are identified in terms of their unique value in teaching career development.
The carbohydrate‐deficient glycoprotein syndromes: An overview
Authors: Jaeken J. , Carchon H.
Published: December 2004

The carbohydrate‐deficient glycoprotein (CDG) syndromes are a newly recognized family of diseases with autosomal recessive inheritance. The basic defects are probably in the glycosylation pathway (endoplasmic reticulum, Golgi apparatus or post‐Golgi). In the present state of our knowledge the central nervous system is always severely affected but nearly all other organs are involved to a variable degree. Like the peroxisomal disorders they also comprise dysmorphic features, the most typical being an abnormal distribution of subcutaneous adipose tissue. A reliable diagnostic test is isoelectric focusing of serum transferrin showing a cathodal shift as a consequence of the partial sialic acid deficiency. Prenatal diagnosis and heterozygote detection are not yet available. These diseases should be differentiated from secondary CDG syndromes such as classical galactosaemia.
Unreliability of platelet glucose‐6‐phosphatase for the diagnosis of glycogen storage disease type Ia
Authors: Goldberg J. D. , Terleaven S. C. , Koresawa M. , Simpson T. , Golbus M. S.
Published: December 2004

The diagnosis of glycogen storage disease type Ia currently uses enzyme analysis of liver tissue. This requires liver biopsy in the at‐risk neonate or fetus. Conflicting reports have appeared in the literature on the use of peripheral platelet glucose‐6‐phosphatase activity for the diagnosis of this disorder. We have applied a sensitive radiometric assay system to the measurement of glucose‐6‐phosphatase activity in peripheral platelets. Two families with affected members were analysed, revealing no differences in glucose‐6‐phosphatase activity as compared with control values. Platelet measurement of glucose‐6‐phosphatase does not appear to be useful for the diagnosis of glycogen storage disease type Ia.
Criteria of Climatic Change in the Inorganic Components of Marine Sediments
Authors: McManus Dean A.
Published: December 2004

The most commonly used criteria in marine sediments for detecting climatic changes are the remains of organisms and the position of the shorelines, for these two types of criteria can have a relatively quick response to climatic change. The inorganic components of marine sediments, however, also provide useful criteria. On the inner continental shelf where the best correlation should be found between modern terrigenous marine sediments and modern climates, sediment texture is the main criterion. Where land ice reaches the sea, gravel may be deposited, but much of the inner shelf in polar climates receives abundant mud, containing a small amount of clay minerals. From tropical humid climates abundant mud is delivered composed mainly of clay minerals, but knowledge of their composition is required, because the largest rivers do not have a dominance of tropical sediment products. In arid climates and midlatitude moderate rainfall climates, inner shelf sand is indicative, although it also possibly reflects the common entrapment of mud in estuaries and the presence of the middle latitude cyclone belt in which storms remove the fine material present on the inner shelf. Climate also controls extensive carbonate deposits. In deep-sea sediments composition contains more important criteria than texture. Some criteria appear to be reliable for various aspects of modern climates and therefore should be useful in detecting climatic changes. These criteria include the size, surface texture, and mineralogical and chemical composition of eolian transported material downwind of arid lands; global dust in latitudinal bands of atmospheric circulation; volcanic ash downwind of geologically instantaneous events; surface texture of quartz grains and the abundance of terrigenous material in pelagic sediments as indication of glaciation; chlorite from a polar climate; kaolinite from a tropical climate, and inorganically precipitated calcium carbonate in enclosed seas. Less definitive criteria are possibly the rate of turbidity current activity, iron-rich layers in the sediment, sedimentation from the nepheloid zone, construction of features by bottom currents, organic matter content, and sedimentation rate. Speculations include the intensity of benthic faunal reworking of sediment. Using these criteria it is possible to identify the sediment products of the extreme climates: polar, tropical rainy, and dry (desert), and thereby to infer the existence of these climates. The moderate climates apparently are not so easily detected. The criteria also indicate the nature of the water, wind, and ice processes delivering the sediment products to the sea. Extreme values in the frequency or magnitude of the climate-associated processes have great significance in the supplying of terrigenous material, and changes in these extreme values could produce salient changes in the sedimentary sequence. The criteria of climatic change might well be considered criteria of change in extreme values of the processes.
A Kinetic Model for the Chemical Composition of Sea Water
Authors: Broecker W. S.
Published: December 2004

The thermodynamic ocean of the Sillen school offers little incentive to those who search the sedimentary record for evidence of changes in ocean chemistry during Cenozoic time. Their models predict a uniform chemical composition. However as the sediments presently accumulating in the ocean show little evidence of equilibration with the overlying water, the possibility that kinetic factors play an important role must be seriously explored. Such a model is presented in this paper. Material balance restrictions are substituted for some of the usual chemical equilibria. The role of organisms is shown to be dominant for at least some of the important components of sea salt (i.e., C, N, P, Si, …). If, as proposed here, the chemistry of sea water is dependent on rates of supply of individual components, the rate of vertical mixing in the sea, and the type of material formed by organisms, then substantial changes in the chemical composition have almost certainly taken place. Several means by which such changes might be reconstructed from chemical and isotopic measurements on marine sediments are discussed.
Investigations of Some Magnetic and Mineralogical Properties of the Laschamp and Olby Flows, France
Authors: Whitney John , Johnson H. P. , Levi Shaul , Evans Bernard W.
Published: December 2004

Rock-magnetic, paleomagnetic and petrologic properties of samples from the Laschamp and Olby basalt formations in France were studied to aid in determining the validity of the Laschamp geomagnetic field reversal reported by Bonhommet and Babkine. The Laschamp flow contains ilmenomagnetite, with partial alteration of the magnetite to hematite. Ilmenomagnetite in the Olby flow has largely recrystallized at high temperatures to a composite mozaic intergrowth of pseudobrookite, titanohematite and magnesioferrite, with rare residual magnetite and lamellae of ilmenite. The remanent magnetization is stable and resides primarily in single-domain magnetite particles. Our results indicate that the magnetizations of the Laschamp and Olby flows faithfully record the direction of the ambient magnetic field in which they cooled.
Correlation of Early Quaternary Events in the U.S. Gulf Coast
Authors: Wylie Poag C.
Published: December 2004

A reexamination of the sequences of planktonic foraminifers and calcareous nannoplankton in the Plio-Pleistocene sediments beneath the Louisiana continental shelf has been undertaken in order to modernize correlation schemes that were established 10–20 y.a. As a consequence, it can be shown that (1) a new correlation of marine micropaleontological and continental glacial events is necessary; (2) the Gulf Coast faunal events can be reliably correlated with those in the type Italian Pleistocene section and in the deep-sea cores; (3) it is becoming increasingly evident that it is invalid to correlate the Plio-Pleistocene boundary, as defined by paleontology, with a climatically defined boundary.
Stalagmites from Caves in the Bahamas: Indicators of low sea level Stand
Authors: Spalding Roy F. , Mathews Thomas D.
Published: December 2004

Presently submerged Bahaman stalagmites can be used to date Pleistocene low sea level stands. Good precision was obtained using both 14C and 230Th-/234U-methods. The respective dates obtained were 21,900 ± 600 and 22,000 ± 350 YBP.
Radiocarbon Dates of Elevated Shorelines, Indonesia and Malaysia. Part 1
Authors: Tjia H.D. , Fujii Shoji , Kigoshi Kunihiko , Sugimura Arata , Zakaria Thomas
Published: December 2004

Four new radiocarbon dates of elevated strandlines in tectonically active areas of eastern Indonesia and East Malaysia indicate average rates of uplift that range between 4.5 and 9 mm annually during the past 24,000 yr. These values are at least three times higher than former estimates from eastern Indonesia. Another radiocarbon date from the south arm of Sulawesi—also tectonically mobile—indicates a rate of uplift of 1.4–2.5 mm per year which corresponds with earlier determinations. This particular case, however, suggests that the sample was probably located close to a north-south axis about which southern Sulawesi was tilted during the Quaternary.

In the Langkawi islands, West Malaysia, one of the regionally ubiquitous shorelines at about 2 m above sea level was dated at 2590 ± 100 yr BP which corresponds with Fairbridge's (1961) Abrolhos Submergence.
Stratigraphic and Radiocarbon Evidence for the Age and Development of Three Salt Lake Deposits in Rajasthan, India
Authors: Singh Gurdip , Joshi R.D. , Singh A.B.
Published: December 2004

A series of radiocarbon determinations have been carried out of lacustrine deposits contained in three playa basins, namely at Sambhar, Didwana and Lunkaransar, in Rajasthan, in conjunction with stratigraphical and palynological investigations. It is revealed that the lake deposits, which overlie thick beds of sand at each site, date back from early Holocene times (ca. 10,000 B.P.).

The authors present the radiocarbon evidence together with an outline of the stratigraphy of the deposits, and attempt to reconstruct the sedimentary sequence in the three basins since the beginning of the lacustrine phase. The significance of the more or less synchronous development in all the three playa basins is discussed with reference to postglacial climatic oscillations in northwest India.
Lithofacies and Environments of Bed I, Olduvai Gorge, Tanzania
Authors: Hay Richard L.
Published: December 2004

Bed I in Olduvai Gorge spans the interval from about 1.7 to 2.0 m.y.a., and all evidences of hominid activity at Olduvai are within the latter half of this period. Bed I was deposited in a closed basin approximately 25 km in average diameter, and it can be subdivided into five lithologically different but partly time-equivalent rock assemblages, or lithologic facies, each of which was deposited in the same geographic environment or closely related series of environments. These lithofacies comprise lake deposits, lake-margin deposits, alluvial-fan deposits, alluvial-plain deposits, and lava flows.

Alluvial-plain deposits form the lowermost part of Bed I, and they presumably interfinger northeastward with lake deposits in an area not now exposed. Discharge of the lavas diplaced the lake westward to a position it occupied through the latter half of the deposition of Bed I. The lake fluctuated greatly in salinity, level, and extent, and at times of low level it was highly saline and generally ranged between 7 and 10 km in average diameter. At times of high level it was as much as 15 km in diameter and was relatively fresh, at least along its southeastern margin. The lake-margin deposits accumulated on the zone of relatively flat terrain that was flooded at times of high level. Lake-margin deposits interfinger eastward with deposits of an alluvial fan of pyroclastic materials produced in an explosive phase of the volcano Olmoti. The climate at the time of Bed I was relatively dry although somewhat wetter than the present climate in the same region today.
Holocene Climatic Variations Inferred from Treeline Fluctuations in the White Mountains, California
Authors: LaMarche Valmore C.
Published: December 2004

Remains of dead bristlecone pine (Pinus longaeva Bailey) are found at altitudes up to 150 m above present treeline in the White Mountains. Standing snags and remnants in two study areas were mapped and sampled for dating by tree-ring and radiocarbon methods. The oldest remnants represent trees established more than 7400 y.a. Experimental and empirical evidence indicates that the position of the treeline is closely related to warm-season temperatures, but that precipitation may also be important in at least one of the areas. The upper treeline was at high levels in both areas until after about 2200 B.C., indicating warm-season temperatures about 3.5°F higher than those of the past few hundred years. However, the record is incomplete, relative warmth may have been maintained until at least 1500 B.C. Cooler and wetter conditions are indicated for the period 1500 B.C.-500 B.C., followed by a period of cool but drier climate. A major treeline decline occurred between about A.D. 1100 and A.D. 1500, probably reflecting onset of cold and dry conditions. High reproduction rates and establishment of scattered seedlings at high altitudes within the past 100 yr represents an incipient treeline advance, which reflected a general climatic warming beginning in the mid-19th century that has lasted until recent decades in the western United States. This evidence for climatic variation is broadly consistent with the record of Neoglacial advances in the North American Cordillera, and supports Antevs' concept of a warm “altithermal age” in the Great Basin.
Astronomical Theory of Climatic Change: Status and Problem
Authors: Chappell J.
Published: December 2004

Quaternary paleotemperatures and sea level records, from both deep sea cores and dated shorelines, provide the basis for testing the Milankovitch hypothesis of climatic change. The longest and most detailed records include (1) oxygen isotope analyses of Caribbean and Atlantic deep sea cores, (2) paleoecological analyses of the same cores, and (3) radiometrically dated raised coral reefs from New Guinea and elsewhere, representing times of relatively high Quaternary sea levels. Time-domain and frequency-domain analysis of these records, shows with a high degree of certainty that Quaternary climatic changes are strongly influenced by the obliquity perturbations and precession of the Earth's orbit. The same analyses also suggest that the time scale adopted by Emiliani for deep sea cores may be more nearly correct than alternative time scales of other workers.

The question of whether insolation changes arising from orbital perturbations can generate ice ages, has been disputed by climatologists. It is shown here that orbital perturbations cannot affect climate indirectly through agencies originating within the Earth, such as vulcanism, and that the primary climatic control is therefore through variation of insolation distribution, as Milankovitch suggested. The conclusion is that climatologic theory must accommodate these facts.
The Vegetation Record of a Mid-Wisconsin Interstadial in Northwest Georgia
Authors: Watts W.A.
Published: December 2004

At Green Pond, a small permanent sinkhole pond in Bartow County, northwest Georgia, organic silty clays are buried by up to 2 m of colluvium. Pollen from the clays shows that a Pinus-Quercus-herb (pine-oak-herb) flora was present before 29,630 radiocarbon yr ago. It is interpreted as the product of a xeric woodland with prairie-like openings. Between 29,630 and approximately 25,000 BP, pollen of Pinus and herbs was sparse; Quercus and Carya (hickory) predominated in the pollen rain. There were few other deciduous trees. Oak-hickory forest is thought to have been present. From 25,000 to 23,000 BP, more diverse forest with pines and some Picea (spruce) became established. At the same time Taxodium (swamp cypress) was locally abundant, as were shrubs characteristic of Coastal Plain swamps. Some time after 23,000 BP, the pond basin filled with colluvium and no further sedimentation took place, other than thin muck sedimented on the bottom of the present Green Pond.

The sediments were first thought to be of Sangamon age because the pollen sequence has many of the characteristics of an interglacial cycle, but the radiocarbon dates correlate them firmly with the Farmdalian Interstadial. A comparison with known Farmdalian sites is made, but the important sites are in the northern United States and adjacent Canada, too far away to make a useful comparison of the details of pollen diagrams from the two areas. At another Bartow County pond site, Bob Black Pond (Watts, 1970), a flora predominantly of pine with spruce and oak was present immediately before 22,900 BP and a strikingly cold flora with jack-pine, spruce and northern herbs followed immediately after. The radiocarbon dates indicate that the sedimentary sequence at Bob Black Pond immediately follows that at Green Pond.
Environmental Sequence following the Fraser Advance of the Juan de Fuca Lobe, Washington
Authors: Heusser Calvin J.
Published: December 2004

Stratigraphic palynology and radiocarbon chronology of two bogs and a lake on the northwestern Olympic Peninsula serve to record the environmental sequence postdating the Fraser maximum of the Juan de Fuca lobe. Wastage of the lobe in the terminal area began before 14,460 ± 200 BP. Differential downwasting followed, and the last remnants of dead ice probably disappeared some time before 9,380 ± 180 BP. Ablation moraine became sufficiently thick in the course of wastage for a vegetation cover to become established. Arboreal remains of this cover, found buried in till, date between 12,020 ± 210 and 13,380 ± 250 BP.

Communities of Pinus contorta first succeeded on deglaciated surfaces during the Vashon Stade. Environmental conditions were comparable to those prevailing in the modern subalpine forest, and average July temperature stood near 12°C. Later, during the Everson Interstade (11,000–13,000 BP.), Alnus and Picea multiplied as temperature increased posibly to as much as 14°. During the Sumas Stade (10,000–11,000 BP.), temperature was again ca. 12°, the cooler climate halting wastage and the spread of Alnus and enabling communities of Picea, Tsuga heterophylla, and T. mertensiana to temporarily achieve stability.

Postglacial environments through the Hypsithermal (ca. 3,000 BP) were dominated principally by Alnus. Alnus, succeeded in turn by Picea, invaded the landscape, following the recession of alpine glaciers and the rise in elevation of the snowline. For a time, as suggested by a peak of Pseudotsuga, temperature may have reached close to 17° and annual precipitation less than 760 mm. Arboreal communities were relatively open while light-requiring Pteridium remained conspicuous in the record. After 3000 BP during Neoglaciation, climate became sufficiently cool and moist to favor the development of extensive, closed communities of Tsuga, Picea, Thuja, and other hygrophilous species.
Sea Level Fluctuation During the Past 6000 yr at the Coast of Mauritania
Authors: Einsele G. , Herm D. , Schwarz H.U.
Published: December 2004

In an area regarded to be very favorable for the study of Holocene sea level changes one or several eustatic (?) oscillations of sea have been found using sedimentological and ecological methods. After a maximum of +3 m during the Nouakchottian stage (= Middle Flandrian or Late Atlantic) about 5500 YBP a drop of sea to −3.5 ± 0.5 m about 4100 YBP is testified by stromatolitic algae indicating the former sea level within the tidal zone with high accuracy. This evidence is supported by the observation of post-Nouakchottian regressive and transgressive geologic sequences, by buried beach deposits and flooded hardgrounds, post-Nouakchottian marine terraces of different height and age, the cutting off of one large and several small bays from the open sea, etc. Possibly one or two smaller oscillations followed between 4000 and 1500 YBP (derived sea level curve Fig. 3).
The Antiquity of Man in South America
Authors: Lynch Thomas F.
Published: December 2004

The initial peopling of South America is reviewed in terms of geochronological and archaeological data. The problem is put in historical perspective and a systematic evaluation is made of the latest typologically oriented arguments for the presence of preprojectile point complexes. Field evidence is very weak for early Biface and Chopper traditions. There is better support for an early Flake tradition, but it is not likely to precede the use of stone projectile points.

Radiocarbon dates and “terrace dating” should be used only with great caution and careful attention to the nature of cultural and stratigraphic associations. Uncritical acceptance of determinations on bone and soil samples has led to extremely problematic cultural reconstructions. Emphasis on stratified sites with finished artifacts, faunal assocations, and charcoal dates leads to a reconstruction at odds with those presented in recent textbooks. It is concluded that the bulk of solid evidence favors the entry of man as a big game hunter using stone projectile points and having an adaptation much like that of the Paleo-Indians of North America.
Absolute Ages of Quaternary Radiolarian Datum Levels in the Equatorial Pacific
Authors: Johnson David A. , Knoll Andrew H.
Published: December 2004

Radiolarian assemblages were examined in two Quaternary cores (V24-58; RC11-209) from the tropical Padific Ocean. Eight radiolarian datum levels were identified in each core, and “absolute” ages were estimated for these levels by interpolation between paleomagnetic reversal boundaries previously established for the cores. The tropical radiolarian zonation for the Quaternary proposed by Nigrini (1971) appears to be most useful in terms of the reliability and ease of identification of the proposed zonal boundaries. Our estimated ages for the base of each of these zones are:Buccinosphaera invaginataZone (Zone 1): 210,000 yr BP;Collosphaera tuberosaZone (Zone 2): 370,000 yr BP;Amphirhopalum ypsilonZone (Zone 3): 940,000 yr BP;Anthocyrtidium angulareZone (Zone 4): 1,700,000 yr BP.

A comparison of our age estimates with those of Quaternary radiolarian datum levels in cores from other regions suggests that significant diachroneity on a scale of up to several hundred thousand years may exist for some (and perhaps all) of these “events.” Diachroneity is most readily studied and documented in late Neogene cores where the absolute ages of the magnetic polarity reversals are known most precisely, but may also exist (though difficult to recolve) in earlier Cenozoic sediments. The existence of such diachroneity, if demonstrated through further studies, would have significant implications for our understanding of evolutionary patterns of planktonic communities in different biogeographic regions.
Frost Sorted Patterned Ground: A Review
Authors: Goldthwait Richard P.
Published: December 2004

Sorted circles, polygons, and stripes are reported from Alaska, Greenland, Baffin Island, Antarctica, and New Hampshire. From these studies and key references, all cases are found to have: (1) a mixed parent material, commonly till, composed of a wide range of clast sizes unsorted below frost table, (2) gutter depressions containing the largest stones and carrying summer drainage, and (3) tabular stones on edge in the gutters showing expansion-squeezing from the sides. The size of the unit cells, gutter to gutter, is a function of mean maximum clast size: smallest chips making forms 10 cm diameter across and largest forms 20 m across. The slope determines the shape: polygons, and nets form on slopes up to 2 or 4° depending upon amount of water and fines. Ellipses form on 3 to 6° slopes, and stripes form on 4 to 11° slopes. Clearly shape is an effect of solifluction. Lastly, time involves seasons of sporadic sorting until there is a stable end form with lichen-covered stone gutters and tundra-covered soil centers. The up-and-out mechanism, described by Corté, is the best known for the primary sorting. Larger sorted forms (2–20 m in diameter) are reported almost exclusively where nearly continuous permafrost exists. They form where the mean annual temperature is below − 4°C. Former permafrost is indicated where lichen and turf are dense and not overturned and where measured motion is nil. Small forms (under 1 m in diameter) are generated in a year or two where there is only deep annual freezing (0.1–2 m), but no permafrost.
Frost Creep and Gelifluction Features: A Review
Authors: Benedict James B.
Published: December 2004

Frost creep and gelifluction are the cold-climate representatives of mass-wasting processes that occur in a broad range of environments. Neither process requires permafrost, and frost creep can be inhibited by its presence at shallow depth. Acting in various combinations, frost creep and gelifluction produce distinctive lobate and terrace-like landforms, which are easy to recognize while fresh and active, but difficult to distinguish from mudflow lobes, earthslides, and similar deposits after they have been modified by other processes. Large frost creep and gelifluction features are currently active in many tundra environments that experience only deep seasonal freezing; thus they are not generally considered to be indicators of permafrost. Most radio-carbon-dated lobes and terraces, however, seem to have originated at times when permafrost was more widespread than it is today. This is true in the Colorado Front Range, where the formation of lobes and terraces appears to have been initiated by rapid melting of ice-enriched permafrost during the warming phases of frost-heave cycles that were centuries or millennia in duration. There is growing evidence that lobes and terraces developed in many parts of the world between about 3000 and 2500 BP; the climatic significance of their formation during this interval is open to several interpretations. Long-term average rates of frontal advance, calculated for deposits in Colorado, Australia, Greenland, Yukon Territory, Alaska, Scotland, and Norway, range from 0.6 to 3.5 mm per calendar year, significantly slower than maximum rates of movement measured on the surfaces of active lobes and terraces in comparable environments; the features are clearly not as effective at transporting debris as was previously supposed. Variations in past rates of downslope soil movement, estimated from close-interval dating of buried humus horizons or plant remains overrun by the advancing fronts of lobes and terraces, provide a sensitive record of climatic change. The dated humus layers are also suitable for detailed pollen analyses and soil chronosequence studies.
Rock Glaciers and Block fields, Review and new data
Authors: White Sidney E.
Published: December 2004

Tongue-shaped and lobate rock glaciers are recognized in most alpine regions today. For the tongue-shaped, two situations emerge: those with buried glacier ice (debris-covered glaciers) called ice-cored rock glaciers, and those with interstitial ice known as ice-cemented rock glaciers. Those with ice cores are revealed by depressions between rock glacier and headwall cliff (where a former glacier melted), longitudinal marginal and central meandering furrows, and collapse pits. Ice-cemented rock glaciers ordinarily do not possess these features. As applied to 18 rock glaciers in the Colorado Front Range, 11 of 12 east of the Continental Divide are ice-cored, 6 west of the Divide are ice-cemented. The majority of lobate rock glaciers in the Colorado Front Range are on the south sides of valleys, and, except for talus, are the most voluminous form of mass wasting. All those active and above treeline have characteristics common to all rock glaciers. In addition, they originate from talus, contain interstitial ice, move outward from valley walls at 1–6 cm/yr, and transport more debris as a process of erosion than heretofore realized. Block fields and block slopes, in polar and alpine regions, are thin accumulations of angular to subrounded blocks, on bedrock, weathered rock, or transported debris. They extend along slopes parallel to the contour. Block streams are similar but extend downslope normal to the contour and into valleys. They are made of interlocked blocks without interstitial detritus, but many have finer material deeper inside. The fabric of surface blocks indicates that motion most likely occurred during a periglacial time when interstitial debris, now washed or piped out, permitted movement of the whole deposit.
Magnetic and Pollen Stratigraphy of the Uonuma Group in Niigata prefecture, North Central Japan
Authors: Nitobe Takashi
Published: December 2004

The Uonuma group, located in the Niigata oil field, represents the upper part of a thick and mostly continuous series of late Cenozoic sediments, in which only the Uonuma is of nonmarine origin. Two main magnetozones and four subzones are recognized and correlated with the Matuyama Reversed and Brunhes Normal polarity epochs. Pollen spectra indicate a climatic deterioration between the Jaramillo Event and the Brunhes/Matuyama boundary, possibly commencing during the Jaramillo Event.
Pliocene and Pleistocene Diatom Datum levels from the Equatorial Pacific
Authors: Burckle Lloyd H.
Published: December 2004

Eight diatom and two silicoflagellate datum levels from the Pliocene and Pleistocene of the equatorial Pacific are ranked and related to the paleomagnetic reversal record, calcium carbonate fluctuations, and the oxygen isotope record. The datum levels and their position with respect to the paleomagnetic reversal record are as follows: (1) last occurrence ofThalassiosira convexamidway between the top of the Gauss and the base of the Olduvai; (2) transition fromRhizosolenia praebergoniitoRhizosolenia praebergoniivar. A just below the base of the Olduvai; (3) first appearance ofPseudoeunotia doliolusin the lower part of the Olduvai; (4) last occurrence ofRhizosolenia praebergoniijust above the Olduvai; (5) first appearance ofAsteromphalus hiltonianusmidway between the top of the Olduvai and the base of the Jaramillo; (6) first appearance ofMesocena ellipticajust below the base of the Jaramillo; (7) last occurrence ofMesocena ellipticamidway between the top of the Olduvai and the base of the Brunhes; (8) upward increase in abundance ofThalassiosira oestrupiijust below the base of the Olduvai; (9) last occurrence ofNitzschia reinholdiijust above the base of the Olduvai; (10) peak occurrence ofRoperia tesselatavar.ovatajust above Datum Level 9. By second-order correlation it is possible to relate these datum levels to the oxygen isotope record. Such a correlation suggests that some datum levels may be climate related.
Paleomagnetic Stratigraphy and Biostratigraphy of the Plio-Pleistocene in the Kinki District, Japan
Authors: Maenaka Kazuaki , Yokoyama Takuo , Ishida Shiro
Published: December 2004

The magnetostratigraphic subdivision of the Plio-Pleistocene series in the Kinki district around Osaka in southwest Japan, based on NRM measurements of volcanic ash beds, is correlated with biostratigraphic and paleoclimatic marker beds as well as past sea level oscillations. At least 10 high sea level stands occurred in the study area between about 1.5 and 0.27 million years ago, all associated with relative warming. A significant change in the composition of flora, from Metasequoia to Fagus dominated assemblages, was observed around the Jaramillo event.