bluuebunny/crossref_metadata_2025 huggingface dataset:
Holocene Soils and Soil-Geomorphic Relations in a Semiarid Region of Southern New Mexico
Authors: Gile Leland H.
Published: July 2006

Holocene soils of a semiarid area in southern New Mexico occur on terraces and fans in and adjacent to the mountains. The illustrative soils have formed in alluvium derived from rhyolite, monzonite, and sedimentary rocks, mainly limestone.

A large arid basin occurs downslope from the mountains. In the arid-semiarid transition, the effect of a gradual increase in precipitation on soil morphology is shown by Holocene soils that sensitively reflect the precipitation. Where the parent materials contain little or no carbonate, a surficial noncalcareous zone and a reddish-brown horizon of silicate clay accumulation thicken mountainward as precipitation increases. The Bt horizon is underlain by the carbonate horizon, the upper boundary of which deepens mountainward. These orographic-depth relations and soil morphology support an interpretation that some of the clay (as well as the carbonate) is of illuvial origin. In high-carbonate parent materials, a noncalcareous zone has not developed and a reddish-brown horizon of clay accumulation has not formed.

In upper horizons, organic carbon increases and color darkens towards the mountains. This causes a change in soils at the categorical level of soil order; Mollisols do not occur in the arid basin downslope, where nearly all Holocene soils are either Aridisols or Entisols. In the semiarid zone, however, most Holocene soils are Mollisols. Thick, dark A horizons have formed in many of these soils. The thickness of these horizons is attributed primarily to episodes of sedimentation during soil development. Some Holocene Aridisols also occur in the semiarid zone. Generally these are on narrow ridges, where the mollic epipedon has been truncated or did not form.

In some terrains the soil-geomorphic relations are complex and Holocene soils may be above or at the same elevation as adjacent, much older soils. In such situations, when the morphological range of the various soils has been determined, soil morphology may be used to distinguish the Holocene soils and surfaces from their older analogs.
Electron Microprobe Data for Tephra Attributed to Glacier Peak, Washington
Authors: Smith Henry W. , Okazaki Rose , Knowles Charles R.
Published: July 2006

Reference samples of three prominent pumice units of Glacier Peak tephra collected east of the volcano within a distance of 100 km are similar petrographically to units described by earlier workers. Glass shards isolated from these samples were analyzed by electron microprobe to determine the content of Ca, Fe, and K. Resulting data, plus those published for two other references samples, provide a basis for attributing certain outlying tephra layers from 14 locations in eastern Washington, Idaho, Wyoming, and Montana to eruptions of Glacier Peak. Ten of the samples have properties of both Glacier Peak tephra and Mount St. Helens set J tephra, but proportions of Ca:Fe:K in glass shards indicate that 9 of the 10 outlying samples came from Glacier Peak, whereas one is assigned to Mount St. Helens set J. The remaining six outlying samples, all from southeastern Washington, contain cummingtonite phenocrysts and are chemically similar to some parts of Mount St. Helens tephra sets that are older than 12,000 BP.
The Tunica Hills, Louisiana-Mississippi: Late Glacial Locality for Spruce and Deciduous Forest Species
Authors: Delcourt Paul A. , Delcourt Hazel R.
Published: July 2006

Reinvestigation of Quaternary sediments in West Feliciana Parish, southeastern Louisiana, and adjacent Wilkinson County, southwestern Mississippi, has resulted in revision of previous terrace stratigraphy of this portion of the Gulf Coastal Plain. Plant-macrofossil and pollen assemblages incorporated in fluviatile terrace deposits in the study area are reexamined in light of the current stratigraphic understanding. Macrofossils identified as white spruce (Picea glauca), tamarack (Larix laricina), and northern white cedar (Thuja occidentalis), recovered from these terrace deposits along with fossil remains of distinctly southern plant species, were initially interpreted as the result of dynamic intermixing of aggressive boreal species within a southern forest during the early Wisconsin (Brown, 1938). Failure to distinguish chronologically separate fossiliferous deposits resulted in the conceptual “mixing” of northern and southern plant species which came from two distinct fluviatile terrace sequences. Terrace 2 is now believed to be a fluviatile and coastwise depositional terrace of Sangamon Interglacial age; deposits of terrace 2 contain a distinctly warm-temperate plant assemblage. Fluviatile terrace 1 dates from 12,740 ± 300 to 3457 ± 366 BP and is now considered to be related to late glacial and Holocene aggradation and lateral migration of the Mississippi River (the local base level for streams in the study area); basal portions of terrace 1 contain fossils of white spruce, tamarack, and many plant species today characteristic of the cool-temperate Mixed Mesophytic Forest Association. Terrace 1 fossil deposits occur in fluviatile terraces along tributary streams of the Mississippi River at elevations 15 to 30 m above the maximum recorded historic flood stage of the Mississippi River. The plant macrofossils represent remains of species that grew at or very near the site of deposition; they were not “rafted in” by floodwaters of the Mississippi River. We present quantitative data for plant macrofossils and pollen that support our hypothesis that at least local cooling along the Blufflands of Mississippi and Louisiana promoted southward migrations of mixed mesophytic forest species and certain boreal species along this major pathway during late Wisconsin continental glaciation.
The Maximum Ice Extent on Island Groups in the Scotia Sea, Antarctica
Authors: Sugden D.E. , Clapperton C.M.
Published: July 2006

Evidence is presented for a more extensive ice cover over South Georgia, the South Orkney Islands, the South Shetland Islands, and the tip of the Antarctic Peninsula. Ice extended across the adjacent submarine shelves to a depth of 200 m below present sea level. Troughs cut into the submarine shelves by ice streams or outlet glaciers and ice-scoured features on the shelf areas suggest that the ice caps were warm-based. The South Shetland Islands appear not to have been overrun by continental ice. Geomorphological evidence in two island groups suggests that the maximum ice cover, which was responsible for the bulk of glacial erosion, predates at least one full glaciation. Subsequently there was a marine interval and then a glaciation which overran all of the lowlying peninsulas. The Falkland Islands, only 2° of latitude north of South Georgia, were never covered by an ice cap and supported only a few slightly enlarged cirque glaciers. This suggests that the major oceanographic and atmospheric boundary represented by the Antarctic Convergence, which is presently situated between the Falkland Islands and South Georgia, has remained in a similar position throughout the glacial age. Its position is probably bathymetrically controlled.
Shasta Ground Sloth (Nothrotheriops shastense Hoffstetter) at Shelter Cave, New Mexico: Environment, Diet, and Extinction
Authors: Thompson Robert S. , Van Devender Thomas R. , Martin Paul S. , Foppe Theresa , Long Austin
Published: July 2006

Seven coprolites of the extinct Shasta ground sloth (Nothrotheriops shastense) were recently discovered in the Los Angeles County Museum collection from Shelter Cave, New Mexico. Three dung balls provided radiocarbon ages of 11,330, 12,330 and 12,430 yr B.P. Packrat (Neotoma) middens disclose a xeric juniper woodland at Shelter Cave during the sloth's occupation. Plant cuticles from the dung indicate that the ground sloth had a diet dominated by mormon tea (Ephedra) and other xerophytic shrubs. Pollen spectra from the coprolites have high representations of anemophilous plants and low representations of the dietary items shown in the cuticle analysis.

Fifteen radiocarbon dates of sloth dung obtained since 1974 strengthen the hypothesis that sloth extinction occurred about 11,000 yr B.P. Paleoenvironmental studies indicate that ground sloths lived in juniper woodlands and montane conifer communities. Nothrotheriops commonly dined on shrubs that are still present in these habitats. It is difficult to explain the demise of the Shasta ground sloth by climatic change or dietary stress. Human predation remains as a possible explanation; ground sloth extinction appears to coincide with the time of Clovis mammoth hunters.
Chemistry and Mineralogy of Some Plio-Pleistocene Tuffs from the Shungura Formation, Southwest Ethiopia
Authors: Martz A. M. , Brown F. H.
Published: July 2006

The Shungura Formation of southwestern Ethiopia has yielded many tens of thousands of vertebrate fossils including hominids and microvertebrates, and in addition has also yielded fossil wood, pollen, and invertebrates. Widespread tuffs have made subdivision and detailed mapping of the formation possible, have provided material for potassium-argon dating, and have allowed direct lithostratigraphic correlation with the Koobi Fora Formation in northern Kenya. The basis for correlation between the two formations is the distinctive chemistry of the tuffs, but systematic chemical variation within some tuffs invalidates some statistical correlation techniques. Here chemical analysis of glass separates and minerals from tuffs of the Shungura and Usno Formations are presented which may allow further ties to be established when data become available on other tuffs of the Koobi Fora Formation. The tuffs consist primarily of glass, but also contain phenocrysts of anorthoclase, hedenbergitic pyroxene, sodic amphibole, ilmenite, titanomagnetite, chevkinite, quartz, zircon, and rarely orthopyroxene and plagioclase. The glasses show evidence of alkali loss during hydration, and are not now peralkaline, although it is likely that they were initially. The source volcanoes were most likely situated within the Ethiopian rift valley, or on its margins.
Late Quaternary Floodplain Sedimentation along the Pomme de Terre River, Southern Missouri
Authors: Brakenridge G. Robert
Published: July 2006

New cross sections and dates from along the Pomme de Terre River clarify the complex local history of valley development and floodplain sedimentation. The observed history begins with a series of ancient bedrock strath terraces that record past bedrock valley positions at 15.5 to more than 58 m above the modern bedrock floor. Each strath is capped by 1–2 m of channel gravel and sand permeated by red clay. Sometime previous to ca. 140,000 yr B.P., a much lower bedrock valley only about 5–6 m above the modern level was excavated. By 140,000 yr B.P., accumulation of red and gray mottled silty clay had commenced, and had reached to 8.5 m above the modern floodplain before 48,900 ± 900 14C yr B.P. Sometime between ca. 49,000 and 45,000 14C yr B.P., erosion caused abandonment of an oxbow meander, and lowered the bedrock valley to about its present depth. Younger yellowish-red and gray mottled silty clay alluvium then began accumulating. This mid-Wisconsinan fill reached to 2.5 m above the modern floodplain sometime before 31,800 ± 1340 14C yr B.P., at which time another erosional phase was in progress. A late Wisconsinan olive clay accumulated between 27,480 ± 1950 and ca. 23,000 14C yr B.P., followed by approximate stability until 13,550 ± 400 14C yr B.P. After stability, an erosional episode began, but by 10,200 ± 330 14C yr B.P., deposition of a distinctive brown clayey silt was underway. This early Holocene fill reached to about the same level as the mid-Wisconsinan fill by 8100 ± 140 14C yr B.P. Erosion occurred between this date and 7490 ± 170 14C yr B.P., but the former floodplain level was rapidly reattained, and was apparently stable until ca. 5000 14C yr B.P. Finally, erosional unconformities and 17 dates from the brown clayey silt, and from younger grayish-brown silty sand underlying the modern floodplain, record subsequent episodes of floodplain erosion at ca. 5000, 2900, 1500 and 350 14C yr B.P. The timing of Pomme de Terre floodplain sedimentary regimes, characterized by net aggradation, erosion, or stability, may have been controlled by climate. In particular, both periods of stability appear to have been coeval to times of strongly zonal upper atmospheric circulation. Intensified zonal circulation would have resulted in less frequent large floods and an increased dominance by floods of small to moderate size. In contrast, there are no obvious parallels to be drawn between this local alluvial history and sea level or glacial outwash induced baselevel changes.
Brunhes-Matuyama Magnetic Reversal Dated at 790,000 yr B.P. by Marine-Astronomical Correlations
Authors: Johnson R. G.
Published: July 2006

The presence of the Brunhes-Matuyama magnetic reversal in deep-sea core sediments makes possible an alternative to the usual K/Ar radioistope method of dating the reversal as found in rocks. The alternative method uses correlations of Northern Hemisphere summer insolation with oxygen-isotope ratios from tropical cores. The latitude-dependent insolation variations are calculated from planetary mechanics and thus provide a highly accurate astronomical time scale. The insolation variations strongly influence glacial-ice volume fluctuations that dominate the oxygenisotope ratio changes recorded in core sediments. The summer half-year insolation variations are identified with corresponding isotope-ratio changes in cores from the present through glacial Stage 20. Misleading effects of discontinuities or major nonuniformities of sediment deposition are avoided by an analysis of the uniformity of V28-238 and V28-239, the principal cores studied, and by comparisons with other cores. The top section (Stages 1 to 10) of V28-238 is uniformly deposited, and for this section an isotope-ratio time scale is chosen that agrees with the thorium-uranium date for the high sea stand of the last interglacial extreme. Over this interval, major glacial extremes (strong isotope-ratio minima) coincide consistently with major insolation minima at times of low orbital eccentricity. In addition interstadials are directly associated with precessional insolation peaks, and the envelope of isotope-ratio peaks resembles the envelope of precessionally dominated insolation peaks. The assumption that the glacial extremes depended similarly on insolation minima during Stages 10 to 20 permits minor age shifts of strong isotope-ratio minima in the two cores (relative to ages based on uniform overal deposition) to match the ages of low-eccentricity insolation minima. The age shifts reflect residual nonuniformities of deposition. The validity of this matching procedure is supported by a resulting consistent identification of principal isotope-ratio peaks with high- and low-latitude coincident insolation maxima. The Brunhes-Matuyama reversal is found intinterglacial Stage 19, and is dated on the astronomical time scale at 790,000 ± 5000 yr B.P.
Seismic Reflection Study of Recessional Moraines beneath Lake Superior and Their Relationship to Regional Deglaciation
Authors: Landmesser C. W. , Johnson T. C. , Wold R. J.
Published: July 2006

Approximately 8000 km of continuous seismic reflection profiles throughout Lake Superior were examined for evidence of recessional moraines and other ice-margin deposits associated with the retreat of late Wisconsin ice. These features are correlated with the record of glacial-lake evolution in western Lake Superior. An offlapping sequence of glacial and glacial-lacustrine sediments overlying bedrock is recognized in west-central Lake Superior that is progressively younger to the northeast. The sequence underlies more recent glaical-lacustrine and postglacial sediments. Four facies are recognized on the basis of geomorphologic and acoustic properties and are interpreted to represent a southwest-to-northeast assemblage of: proglacial stratified drift (facies A), drift in major end moraines (facies B), till deposited as glacial retreat resumed, or possibly late-stage ablation till (facies C), and basal till (facies D). The prominent moraines of facies B are unusually thick and are believed to mark the ice-margin shorelines of successive major proglacial lakes that formerly occupied parts of western Lake Superior. The moraines are tentatively correlated with Glacial Lake Duluth (unit 1), Glacial Lake Washburn (unit 2), and Glacial Lake Beaver Bay (unit 3), the most prominent of lakes drained via the progressively lower outlets via the Moose Lake/ Brule-St. Croix Rivers, the Huron Mountains, and the Au Train-Whitefish regions, respectively.
Level of Lake Lahontan during Deposition of the Trego Hot Springs Tephra about 23,400 years ago
Authors: Davis Jonathan O.
Published: July 2006

The Trego Hot Springs tephra bed is a silicic tephra about 23,400 yr old, found at several localities in pluvial lake sediments in northern Nevada, southern Oregon, and northeastern California. It has been characterized petrographically, by the major and minor element chemistry of its glass, and by its stratigraphic position with respect to other tephra layers. At a newly described locality on Squaw Creek, northwest of Gerlach, Nevada, at the north end of the Smoke Creek Desert, Trego Hot Springs tephra has been found in sediments of the Sehoo and Indian Lakes formations. The depositional environments of these sediments show that when the tephra fell, pluvial Lake Lahontan stood between 1256 and 1260 m, and that immediately thereafter the lake rose to at least 1275 m. These data corroborate earlier findings by Benson (Quaternary Research9, 300–318) from radiometric dating of calcareous tufa. However, the Lake Lahontan area has been affected by isostatic subsidence and rebound in response to changing water loads, so that caution is required in the use of lakeshore elevations in correlation.
Lake-Level Variation in the Lahontan Basin for the Past 50,000 Years
Authors: Benson L. V. , Thompson R. S.
Published: July 2006

Selected radiocarbon data on surficial materials from the Lahontan basin, Nevada and California, provide a chronology of lake-level variation for the past 50,000 yr. A moderate-sized lake connected three western Lahontan subbasins (the Smoke Creek-Black Rock Desert subbasin, the Pyramid Lake subbasin, and the Winnemucca Dry Lake subbasin) from about 45,000 to 16,500 yr B.P. Between 50,000 and 45,000 yr B.P., Walker Lake rose to its sill level in Adrian Valley and spilled to the Carson Desert subbasin. By 20,000 yr B.P., lake level in the western Lahontan subbasins had risen to about 1265 m above sea level, where it remained for 3500 yr. By 16,000 yr B.P., lake level in the western Lahontan subbasins had fallen to 1240 m. This recession appears synchronous with a desiccation of Walker Lake; however, whether the Walker Lake desiccation resulted from climate change or from diversion of the Walker River is not known. From about 15,000 to 13,500 yr B.P., lake level rapidly rose, so that Lake Lahontan was a single body of water by 14,000 yr B.P. The lake appears to have reached a maximum highstand altitude of 1330 m by 13,500 yr B.P., a condition that persisted until about 12,500 yr B.P., at which time lake level fell ≧100 m. No data exist that indicate the level of lakes in the various subbasins between 12,000 and 10,000 yr B.P. During the Holocene, the Lahontan basin was the site of shallow lakes, with many subbasins being the site of one or more periods of desiccation. The shape of the lake-level curve for the three western subbasins indicates that past changes in the hydrologic balance (and hence climate) of the Lahontan basin were large in magnitude and took place in a rapid step-like manner. The rapid changes in lake level are hypothesized to have resulted from changes in the mean position of the jet stream, as it was forced north or south by the changing size and shape of the continental ice sheet.
Radiocarbon Dating and Paleoclimatic Significance of Subfossil Limicolaria in Northwestern Sudan
Authors: Haynes C. Vance , Mead Albert R.
Published: July 2006

The discovery, identification, and radiocarbon dating of the large achatinid land snail Limicolaria kambeul chudeaui at six places in northwestern Sudan, north of the 100-mm isohyet, provide convincing evidence that at least 300 mm annual rainfall existed there 6000 yr ago. Since then the rainfall north of ca. 20°N lat in the eastern Sahara has certainly been <300 mm and probably <200 mm. Accelerator mass spectrometry has allowed the organic fraction, presumably conchiolin, to be accurately radiocarbon dated whereas carbonate fractions are ca. 600 yr too old. Comparative studies show the subfossil form, L. k. chudeaui, to be the most primitive in its species complex and to occupy a narrow east-west belt across Africa north of 15°N and west of 35°E. The northern limit of living forms lies within the southern part of the Sahelian zone in forest or forest-savanna. They cannot live in open grassland. Therefore, the distribution of L. k. chudeaui marks the former northern position of this zone during the middle Holocene, indicating a latitudinal shift of at least 5° (500 km).
Late Quaternary Climatic Change in France Estimated from Multivariate Pollen Time Series
Authors: Guiot Joël
Published: July 2006

In regions like southern France, where usual analytical techniques are unsatisfactory due to the heavy influence of human activity and the existence of a complex climate, the quantitative reconstruction of climate from pollen is particularly difficult. That is why an original method has been performed. The first step of the method, based on best analogs estimation and multiple regression, is to calculate a relationship between climate (monthly temperature and precipitation) and modern pollen spectra for data from 182 sites. The result is called the “analog climate.” The second step of the method, an original combination of canonical correlation and principal components analyses, extracts the common information from several fossil pollen sequences to produce a so-called “paleobioclimate.” This step removes the effects of local differences in the vegetation among nearby sites and also reduces the effects of human disturbance. In the third step, the signals obtained from the first two steps are merged, by Kalman filter, into a final reconstruction where the noise is reduced by around 37%. The results, presented with a 95% confidence level, suggest that the Pleni-Würm was 7° to 13°C colder than present and had 20 to 60% less precipitation than today (this large confidence takes into account the climatic diversity of the region). At 13,000 yr B.P., the climate reached the modern level of precipitation but the temperature was just less than present. The subsequent decrease of precipitation is less important than that of temperature. This fact may explain the advance of alpine glaciers during the Younger Dryas. Preboreal warming was abrupt (3° to 4°C per 500 yr) and precipitation increased more slowly.
Polar Perspective of Late-Quaternary Climates in the Southern Hemisphere
Authors: Heusser Calvin J.
Published: July 2006

Late-Quaternary paleoecological and glacial evidence from the higher latitudes of the Southern Hemisphere implies overall uniformity of large-scale glacial and interglacial climatic fluctuations for the past 40,000 yr. Climate of the last glacial maximum, variously dated between 30,000 and 11,000 yr B.P., was relatively cold and dry compared with the warmer, more humid climate of the Holocene and the interstade preceding the last glacial maximum. Conditions were apparently coldest during millennia centered around 20,000 yr B.P. and warmest in the early Holocene. Recorded small-scale fluctuations, frequently variable for any given time interval, are less consistent. A cold late-glacial episode, estimated as occurring between ca. 13,000 and 11,000 yr B.P. in Antarctica, possibly was coeval with the Younger Dryas Stade in northwestern Europe and may be correlative with a climatic episode in southern South America and perhaps in New Zealand and South Georgia; however, there is no evidence for the event in Tasmania. General atmospheric circulation models for the polar latitudes at the time of the last glacial maximum show an intensification of the southern westerlies, apparently a result of the expansion of ice cover in Antarctica and of sea ice in the Southern Ocean.
Holocene Alluvial Fills in the South Loup Valley, Nebraska
Authors: May David W.
Published: July 2006

Four Holocene alluvial fills are present in Nebraska's South Loup River valley. Fill IV, the oldest and thickest, was deposited between 10,200 and 4800 14C yr B.P.; Fill III has an age of about 3000 14C yr B.P.; Fill II is younger than 2100 and older than 900 14C yr B.P.; and Fill I is younger than 900 14C yr B.P. Regional contemporaneity of valley alluviation in the eastcentral Great Plains suggests that climate has controlled long-term sediment storage in the South Loup River valley.
Does Altonian Drift Exist in Pennsylvania and New Jersey?
Authors: Ridge John C. , Braun Duane D. , Evenson Edward B.
Published: July 2006

From New Jersey to southwestern New York, Altonian colluvium and fluvial gravel have been recognized beneath Woodfordian drift, but the existence of Altonian till near or beyond the Woodfordian border has not been demonstrated. Reworking of weathered materials by Woodfordian ice has produced some drift with an “Altonian” appearance. Soil criteria, applied without regard for parent material differences, have been incorrectly used to infer an Altonian age for Illinoian deposits that have a redbed provenance. The currently mapped distribution of Altonian till and the occurrence of undisturbed Illinoian deposits within areas of inferred Altonian ice cover are incompatible with the behavior of ice sheets.
Pleistocene Stratigraphy of the Boston Harbor Drumlins, Massachusetts
Authors: Newman William A. , Berg Richard C. , Rosen Peter S. , Glass Herbert D.
Published: July 2006

Evidence from the Boston Harbor drumlins indicates that two superposed tills were deposited during glacier advances which were separated by a long nonglacial interval. At Long and Peddocks Islands, argillans and truncated clay-filled fractures, along with discontinuities in clay-mineral composition, define the till contacts. Physical indicators separating the tills are not apparent at other exposures, where till boundaries were defined solely by discontinuities in clay-mineral composition. The weathering profile in the upper part of the lower till indicates extensive weathering under a climate similar to that of today, and probably similar to that of the Sangamon Interglaciation. The depth of the weathering profile, the sequence of clay-mineral alteration products, and the presence of pedogenic features in the upper part of the lower till are comparable to Sangamonian weathering profiles in the midwestern United States, implying that the lower till is Illinoian or older.
Palynological Evidence for Increased Aridity on the Central Chilean Coast during the Holocene
Authors: Villagrán Carolina , Varela Juan
Published: July 2006

The late Quaternary vegetation of the semiarid coast of central Chile is inferred from the palynological analysis of profiles from Quereo (31°55′S) and Quintero (32°47′S). Prior to 11,400 yr B.P., wet conditions are suggested by the abundance of pollen indicators of swamp and aquatic taxa, such as Cyperaceae and Myriophyllum, and by the presence of traces of arboreal pollen. Since ca. 10,000 yr B.P., a trend toward increasingly drier conditions is implied by the almost complete absence of arboreal and aquatic taxa, and a general decrease in the diversity of the semiarid shrubland indicators. From 3000 yr B.P. onward, the pollen records show the reappearance of swamp and aquatic taxa, presumably associated with wetter conditions, which led to recolonization by forest taxa at 1720 yr B.P. in Quintero. The drier climate detected along the semiarid coast of central Chile during most of the Holocene extended inland to the Andean foot-hills, within the present mediterranean-type climate zone of Chile, and also affected the distribution of the winter-deciduous Nothofagus forests and the northern boundary of the temperate rain forests.
Size variation in the Cape dune molerat (Bathyergus suillus) and late Quaternary climatic change in the southwestern Cape Province, South Africa
Authors: Klein Richard G.
Published: July 2006

Within their historic range at the southwestern tip of Africa, Cape dune molerats (Bathyergus suillus) tend to be significantly larger in areas of higher rainfall. They also tend to be large in late Quaternary fossil samples associated with independent evidence for relatively moist climate and small in samples associated with evidence for relatively dry conditions. Together with sedimentologic/geomorphic and other faunal observations, fluctuations in fossil dune molerat size imply that the regional climate was very moist during an early late Quaternary interval corresponding to marine isotope stage 4 (74,000 to 59,000 yr B.P.) or perhaps to substage 5b or 5d (centered on 110,000 and 90,000 yr B.P., respectively.) It was comparably moist again from roughly 14,000 to 8,000 yr B.P., somewhat drier than at present from about 8000 until 4000 yr B.P., and mainly near the modern average after 4000 yr B.P. Together, the modern and fossil data suggest that dune molerat size is a reliable index of past precipitation, but it may not be useful for revealing extremely arid conditions because these seem to be associated with depositional/occupational gaps in most local paleontological/archeological sites.
Relative dating of Quaternary moraines, Rongbuk valley, Mount Everest, Tibet: Implications for an ice sheet on the Tibetan Plateau
Authors: Burbank Douglas W. , Cheng Kang Jian
Published: July 2006

Relative-dating studies applied to high-altitude moraines (5000–5500 m) in the Rongbuk valley on the northern flank of Mt. Everest reveal strong contrasts in the weathering characteristics of the boulders exposed along moraine crests. These differences serve to define three intervals of major Pleistocene glaciation that, on the basis of the degree of weathering, are interpreted to extend back to at least the penultimate glaciation and probably encompass at least one still older glaciation. Either interpretation indicates that some of these moraines are considerably older than their previously assigned ages. The magnitude of equilibrium-line lowering during Neoglacial and late Pleistocene times is calculated to be ca. 50–100 and 350–450 m, respectively. The data described here are incompatible with the recently proposed model (Kuhle, 1987) for large-scale ice-sheet development on the Tibetan Plateau. The reconstructed equilibrium-line lowering in the Everest region is only 30% of that cited in the ice-sheet model. Moreover, the flow patterns and geometry of the former Rongbuk glaciers are in opposition to those proposed by the model. Based on the data from the Everest region, it appears that valley glaciation, rather than ice-sheet growth, characterized the southern margin of the Tibetan Plateau during the middle and late Pleistocene glaciations.
Laurentide Ice Sheet Extent Inferred from Stable Isotopic Composition (O,C) of Ostracodes at Toronto, Canada
Authors: Schwarcz Henry P. , Eyles Nicholas
Published: July 2006

Early and Middle Wisconsin glaciolacustrine sediments exposed at Scarborough Bluffs, Toronto, Canada, contain a low-diversity benthic ostracode fauna dominated by Candona subtringulata and C. caudata. We have studied the oxygen and carbon isotopic compositions of the two ostracode species from the base of the Scarborough section to its top immediately below a Late Wisconsin till. We find an upward decrease in δ18O in both species that is more marked in C. caudata. The shift in δ18O of ostracode calcite from interglacial values of −6 to −8‰, to values of −17‰ immediately below the Late Wisconsin till is the result of (1) lowering of δ18O of the lake as a result of addition of isotopically light meltwater from an advancing and thickening Laurentide Ice Sheet combined with (2) lowering of δ18O of local precipitation entering the lake, due to falling temperatures. In the last stages of the lake, δ18O of the lake water was between −17 and −21‰, corresponding to a lake body composed of between 35 and 55% glacial meltwater. The lake appears to have been isotopically and thermally stratified for part of its history. Differences in δ13C values between C. caudata and C. subtriangulata increase upward in the stratigraphic section. This may record enhanced partitioning of carbon isotopes between surface and bottom waters as a result of increased water depths, photosynthesis by algae, and changes in the input of dissolved organic carbon from the oxidation of organic matter. If the age assessments of these sediments are correct, then these data provide valuable information regarding the isotopic composition of ancestral Lake Ontario and also confirm that the basin was only fully glaciated during the Late Wisconsin.
Soil-Carbonate Genesis in the Pinacate Volcanic Field, Northwestern Sonora, Mexico
Authors: Slate Janet L. , Bull William B. , Ku Teh-Lung , Shafiqullah Muhammad , Lynch Daniel J. , Huang Yi-Pu
Published: July 2006

Uranium-series methods were used to date and evaluate pedogenic CaCO3 genesis in the Pinacate volcanic field, northwestern Sonora, Mexico. Soils are developed in eolian deposits on lava flows. 230Th/234U dates of pedogenic carbonate are mininum soil ages because of (1) the time needed to yield clasts from flows and to accrete enough carbonate to sample, (2) subsequent additions of uranium, and (3) continued solution and reprecipitation of carbonate rinds. K-Ar dates of basalt flows are maximum soil ages. Maximum and minimum rates of CaCO3 accumulation are calculated from the Th/U dates and K-Ar dates, respectively. The mean maximum rate is 0.13 g CaCO3/cm2/1000 yr and the mean minimum rate is 0.05 g CaCO3/cm2/1000 yr. Least-squares regressions of pedogenic carbonate and clay content and of Th/U ages against K-Ar ages suggest additions to soils from atmospheric sources throughout the late Quaternary. Morphology of pedogenic carbonate and laboratory data for soluble salts indicate that the climate of the Pinacate has not changed significantly during the past 150,000 yr. Soil variability is influenced by proximity of the eolian source. Near the periphery of the Pinacate, carbonate and clay are evenly distributed throughout soil profiles. Within the volcanic field, carbonate and clay are concentrated in soil horizons, suggesting that additions from atmospheric sources are slow enough to allow translocation.
Obsidian Hydration Dating and Temperature Controls in the Punta Negra Region of Northern Chile
Authors: Lynch Thomas F. , Stevenson Christopher M.
Published: July 2006

Effective hydration temperature (EHT) is essential for the computation of obsidian hydration dates. In the Atacama Desert, the scarcity of air-temperature records combines with extremes of elevation and local temperature to encourage, or even require, the use of buried thermal cells to record on-site mean annual temperatures. Compositional analysis (sourcing) and hydration rate development in the laboratory are also necessary, especially where other dating methods are unavailable to confirm the hydration rate. Paleoindian or Early Archaic through modern obsidian dates support a human settlement pattern history derived from archaeological/geomorphological studies of climatological and hydrological change.
Carbon Isotope Composition of Lake Sediments in Relation to Lake Productivity and Radiocarbon Dating
Authors: Aravena Ramon , Warner Barry G. , MacDonald Glen M. , Hanf Karen I.
Published: July 2006

Carbon-13 profiles and radiocarbon dates were obtained from two Canadian kettle basins having similar geological and hydrological characteristics to develop criteria for evaluating the validity of radiocarbon dates on lake sediment from basins in calcareous terrain. Radiocarbon dates from a site in Alberta show a variable hard-water effect related to local hydrological changes during postglacial history of the lake basin, whereas radiocarbon dates from the other site in Ontario show no noticeable influence of old carbon during its history. These differences are mainly related to lake water residence time, which has influenced carbon isotopic exchange between atmospheric CO2 and dissolved inorganic carbon in lake water. δ13C values for bulk organic sediment and terrestrial and aquatic macrofossils reveal that the main component of lake sediment at both sites is autocthonous in origin. Furthermore, each site supported different submerged aquatic plant communities that used different sources of carbon for photosynthesis, thereby imprinting the organic sediments with a characteristic 13C composition. Both sites reflect a clear relationship between 13C values and paleoproductivity. This study shows the individualistic response of the developing lake system to the hydrology, lake biota, and local geology, and demonstrates the problem of using 13C in lake sediments as a single criterion to recognize the validity of radiocarbon dates of lake sediment without supporting paleoecological information.
Factor structure of the 12‐item aggression questionnaire: Further evidence from Asian adolescent samples
Authors: Ang Rebecca P.
Published: July 2006

Bryant and Smith [(2001). Refining the architecture of aggression: A measurement model for the Buss‐Perry Aggression Questionnaire. Journal of Research in Personality, 35, 138–167] refined the 29‐item Aggression Questionnaire and obtained a 12‐item short form of the AQ that has yet to be validated with samples outside of North America and England. Confirmatory factor analysis (CFA) with two Asian adolescent samples revealed that while the hierarchical AQ model had an acceptable fit to the data, the multidimensional AQ model demonstrated a superior fit. The unidimensional AQ model was shown to be an unacceptable measurement model in both samples. Results obtained replicated previous findings using the original 29‐item measure and supported the AQ's multidimensionality. Multigroup CFA analyses revealed partial measurement invariance for the 12‐item fourfactor AQ model for both samples with respect to gender. Supplementary t‐tests revealed a consistent gender difference on physical aggression in the male direction for both samples and a gender difference on verbal aggression in the male direction only for one sample. No other gender differences were found. These results are consistent with recent meta‐analytic research.
Women's mental health: A silent cause of mortality and morbidity
Authors: Stewart D.E. , Ashraf I.J. , Munce S.E.
Published: July 2006

It is estimated that 450 million individuals worldwide are affected by mental, neurological or behavioral problems at any time, and that 873,000 die annually by suicide. Key international authorities and a literature review suggest that women are disproportionately affected by depression, anxiety and eating disorders, which usually go unrecognized and untreated, and that the mental health of women can be understood only if their biological, social, cultural, economic and personal context is considered. International efforts should increase to prevent, recognize and treat mental disorders in girls and women. An International Women's Mental Health Consensus Statement is herein provided, for endorsement by interested organizations wishing to begin this task.
Evaluation of a novel immunotherapy for treatment of chronic rhinitis in cats
Authors: Veir Julia K , Lappin Michael R , Dow Steven W
Published: July 2006

The pathogenesis of chronic rhinitis in cats is poorly understood and consistently effective therapies are not currently available. Therefore, randomized clinical trials were conducted to evaluate a novel immunotherapy for treatment of chronic rhinitis in adult ( n=12) and young cats ( n=28). In addition, cytokine profiles in cats with chronic rhinitis were compared to those of healthy cats. Cats were treated with a potent stimulator of innate immunity (liposome–IL-2 DNA complexes) and the effects of treatment on clinical signs and immune function were assessed. In adult cats with chronic rhinitis, immunotherapy led to significant improvement in frequency of sneezing but not in other clinical signs when compared to the placebo group, whereas immunotherapy failed to improve clinical signs in younger cats. Analysis of cytokine expression in cats with rhinitis did not reveal evidence of a Th2 cytokine bias in cats with rhinitis. We conclude that chronic rhinitis in cats is not a Th2-biased disease and that immunotherapy may lead to clinical improvement in adult cats with the disease.
Suspected clindamycin-associated oesophageal injury in cats: Five cases
Authors: Beatty Julia A , Swift Nigel , Foster Darren J , Barrs Vanessa RD
Published: July 2006

The clinical findings, treatment and outcome of suspected clindamycin-associated oesophageal injury in five cats are reported. All cats were treated with one 75 mg clindamycin capsule twice daily (dose range 12–19 mg/kg). Capsules were administered without food or a water bolus. Dysphagia, regurgitation, choking or gagging were seen 3–9 days after starting clindamycin. On oesophagoscopy, three cats had oesophagitis, one of which progressed to stricture formation. Two cats had an oesophageal stricture at first presentation. This is the first report of suspected clindamycin-associated oesophageal injury in cats. It serves to further alert practitioners to the potential for drug-induced oesophageal disorders (DIOD) in cats treated with oral medications and to urge prevention by promoting a change in dosing practices.
Prevalence of Mycoplasma haemofelis, ‘Candidatus Mycoplasma haemominutum’, Bartonella species, Ehrlichia species, and Anaplasma phagocytophilum DNA in the blood of cats with anemia
Authors: Ishak Anthony M. , Radecki Steve , Lappin Michael R.
Published: July 2006

Hemoplasmas are known causes of anemia in some cats and some Bartonella species have been associated with anemia in people and in dogs. In this retrospective study, we used polymerase chain reaction (PCR) assays to determine the prevalence rates of Mycoplasma haemofelis, ‘ Candidatus M haemominutum’, A phagocytophilum, Ehrlichia species, and Bartonella species DNA in the blood of cats with anemia and a control group of healthy cats. DNA of the organisms was amplified from 22 of 89 cats with anemia (24.7%) and 20 of 87 healthy cats (23.0%). DNA of a hemoplasma was amplified from 18 of 89 cats with anemia (20.2%) and 13 of 87 healthy cats (14.9%); DNA of a Bartonella species was amplified from five of 89 cats with anemia (5.6%) and seven of 87 healthy cats (8.0%). There were no statistically significant differences detected between groups.
Process innovativeness in technology services organizations: Roles of differentiation strategy, operational autonomy and risk‐taking propensity
Authors: Das Sidhartha R. , Joshi Maheshkumar P.
Published: July 2006

This paper examines the effect of differentiation strategy on process innovativeness in technology services organization (TSOs). In addition it examines the direct and moderating effects of two organizational constructs—operational autonomy and risk‐taking propensity. Analysis of data from 102 firms in the mid‐Atlantic region of the USA indicates that both differentiation strategy and operational autonomy are positively related with process innovativeness, while an organization's risk‐taking propensity has no such relationship. In addition, operational autonomy moderates the relationship between differentiation strategy and process innovativeness, while no evidence was found for the moderating effect of risk‐taking propensity on this relationship. Further sub‐group analysis shows that in TSOs with high levels of operational autonomy, risk‐taking propensity has a positive moderating effect on the above relationship. Post hoc analysis also establishes positive links among process innovativeness and firm performance.
Holt, Modigliani, Muth, and Simon's work and its role in the renaissance and evolution of operations management
Authors: Singhal Jaya , Singhal Kalyan
Published: July 2006

Early work in aggregate production planning has evolved into a major business process known as sales and operations planning. In the 1950s, a team led by Holt, Modigliani, Muth, and Simon, which also included Bonini and Winters, worked on aggregate production planning and forecasting and published a series of papers and a book. The literature contains reports of at least 73 applications of their work in four companies and three application studies. Holt et al.'s work and its visibility led to a renaissance of the field of operations and supply chain management as we know it today and brought two paradigm changes in the domain and the role of operations and supply chain management. First, seemingly unrelated and non‐managerial individual functions started to emerge as parts of an integrated system of managing production. Second, aggregate production planning brought to forefront the central role of operations management by linking it with supply chains and other functions in the organization.
Cocaine: what role does it have in current ENT practice? A review of the current literature
Authors: Harper S J , Jones N S
Published: July 2006

Topical cocaine is used by many otorhinolaryngologists because of its good local anaesthetic and vasoconstrictive properties. A review of the available literature suggests a risk/benefit analysis would suggest that in the out-patient setting local anaesthetic agents which do not contain cocaine should be used. For rhinosurgical procedures, preparations containing cocaine and adrenaline in the appropriate concentrations and doseage are safe in the vast majority of patients without previous cardiac disease. The relative benefit of using cocaine in relation to other topical analgesics and vasoconstrictors in surgery remains unproven and alternative preparations should be used wherever there is concern over the cardiac status of the patient.

It is important to be alert to the possibility that patients presenting with a septal perforation or destructive midfacial lesions may be suffering from an addiction to cocaine. It is important to arrive at the correct diagnosis in a destructive process and even in the presence of raised antineutrophilic cytoplasmic antibodies (ANCA) a diagnosis of cocaine abuse should actively be excluded.
Idiopathic sudden sensorineural hearing loss: prognostic factors
Authors: Xenellis J , Karapatsas I , Papadimitriou N , Nikolopoulos T , Maragoudakis P , Tzagkaroulakis M , Ferekidis E
Published: July 2006

Objectives: Sudden sensorineural hearing loss (SSHL) remains a challenge for the clinician. In the majority of cases, no definite cause can be found and the prognosis is variable.

Methods: The present study assessed 114 patients suffering from idiopathic SSHL, with regard to the prognostic value of demographic, epidemiologic, neurotologic and audiometric factors. In addition, the relationship between the identification of wave V in auditory brainstem responses and the final hearing outcome was investigated. All patients received 75 mg/day intravenous prednisolone, divided into three daily doses, for 10 days, with gradual tapering of the dose over the next 10 days.

Results: The results (after one year follow up) revealed the following factors to be related to a better hearing outcome: younger age; male sex; less time elapsed between the onset of hearing loss and the beginning of treatment; and an upward-sloping or cupeloid audiogram contour. The detection of wave V early in recovery and within the first month of medical treatment might also constitute a significant favourable factor in respect to hearing recovery.

Conclusions: The present study revealed that there are certain factors that affect prognosis in idiopathic SSHL. This is very important in counselling patients and may affect current clinical practice.