bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prehispanic Adaptation in the Ixtapalapa Region, Mexico
Authors: Blanton Richard E. 
Published: October 2006

Data accumulated during an intensive survey of Prehispanic settlements in the Ixtapalapa Peninsula region enables me to formulate hypotheses regarding the nature of sociocultural change and adaptation during the Prehispanic period. A summary of these hypotheses follows. The Early and Middle Formative period was a time of low population, when most communities were located on or near the agriculturally productive lakeshore plain zone. During the subsequent period, attendant upon the development in the central highlands of more productive varieties of maize, population increased, and for the first time the agriculturally marginal piedmont zone was colonized. This process may have resulted in the enhancement of status differentiation in these societies because some communities maintained access to the preferred land along the lakeshore plain zone. Also, occupation of a variety of environmental zones may have encouraged symbiosis, which could have further enhanced status differentiation as some individuals or groups became the focuses of exchange networks. During the Late Formative period, developments along this line proceeded throughout the Valley of Mexico, but later, during the Terminal Formative period, some groups prospered more than others because they were favorably situated for the construction of large-scale irrigation systems. The foremost example of the latter is Teotihuacan, which eventually dominated the population of the Ixtapalapa Peninsula region, as well as the remainder of the Valley of Mexico and probably adjacent groups in the central highlands.
From A.D. 0 to A.D. 700, the region was dominated by Teotihuacan. This was a period of low population and apparently rural settlement patterns. A similar situation existed during the Late Toltec period as Tula dominated the region. I suggest that Teotihuacan and Tula had similar relationships with their rural peripheries; specifically, they were largely extractive and so dominated rural populations that they were the only important focuses of exchange and craft specialization. Population declined in the rural areas in part because they were too far from the urban centers to participate effectively in the exchange networks. In contrast, the Aztec period was characterized by the presence of a number of urban centers scattered widely over the valley; these centers served as the focuses of exchange and specialization. A similar situation may have characterized the Early Toltec period. During the Aztec period, the combination of intensive local and valleywide symbiosis plus the introduction of chinampas allowed the population to reach the greatest density of the Prehispanic period.
The Beginnings of Metallurgy: A New Look
Authors: Wertime Theodore A. 
Published: October 2006

In the 9 years since my first survey of early metallurgy appeared in this journal metallurgy has become a major battleground between those who argue independent invention and those who argue diffusion in the evolution of urban civilization. In this new article I contend that:
1) The upland belt and debouching river valleys of southwestern Asia have a clear priority in the beginnings of copper metallurgy and extractive metallurgy generally, suggesting that the forces of urbanization contributing to the rise of metallurgy there were more massive, widespread, and better integrated than elsewhere.
2) The trend to polymetallism, against the background of pyrotechnology generally and the other important technologies of urbanism, established a necessary sequence to early metallurgy. This sequence was a prerequisite to the coming of the Iron Age, which was uniquely contained at first within the environment of Anatolia and the eastern Mediterranean and spread outward from there.
3) The course of metallurgy and possibly of the other urbanizing technologies can best be understood through a process of diffusion and multiple innovation interrelating metallurgical evolution over much of Eurasia, but with the area defined by the Black Sea, the Caspian Sea, the Red Sea, and the eastern Mediterranean as its center. Only in this fashion can we place metallurgy in its proper role as an important subsystem in the rise of civilization.
University Isotope Separator at Oak Ridge: The UNISOR Consortium
Authors: Hamilton J. H. 
Published: October 2006

The UNISOR cooperative project, envisioned more than 3 years ago, is now successfully working. Research problems that involve a full range of experiments on nuclei far from beta stability are being investigated jointly by groups of scientists from several institutions. Some of the first work reported included the identification, half-lives, and decay schemes of three new isotopes,
186
Tl,
188
Tl, and
116
I; the first or new decay schemes of
189
Tl,
190
Tl,
117
Xe, and
117
I; and the results of the perturbed gamma-gamma directional correlation work in
126
Xe.

UNISOR is already stimulating international interest. A report on the new research being planned with an isotope separator on-line to ORIC was presented at a Soviet Academy of Sciences meeting on nuclear structure in 1971. At an international nuclear physics conference in Munich in August 1973, Academician G. N. Flerov, director of the heavy-ion laboratory in Dubna, said the UNISOR project had inspired his laboratory to secure funds for a new, much improved isotope separator which is now installed on-line to their heavy-ion cyclotron to be used for detailed studies of nuclei far from stability.
The UNISOR model for research has inspired a second such project, the Atomic Physics Consortium at Oak Ridge (APCOR). After an exploratory conference at Oak Ridge, scientists from ten institutions met in November 1973 to form an organizing committee for APCOR. As with UNISOR, the universities and the AEC will each provide a significant portion of the capital and operating costs. Heavy ions have opened up much new research in atomic physics, but such accelerator-based research represents a real "shift from traditional approaches concerning how, where, and on what time scale atomic physics experiments should be done".
Hydration Rate of Obsidian
Authors: Friedman Irving , Long William 
Published: October 2006

The hydration rates of 12 obsidian samples of different chemical compositions were measured at temperatures from 95° to 245°C. An expression relating hydration rate to temperature was derived for each sample. The SiO
2
content and refractive index are related to the hydration rate, as are the CaO, MgO, and original water contents.

With this information it is possible to calculate the hydration rate of a sample from its silica content, refractive index, or chemical index and a knowledge of the effective temperature at which the hydration occurred. The effective hydration temperature can be either measured or approximated from weather records. Rates have been calculated by both methods, and the results show that weather records can give a good approximation to the true EHT, particularly in tropical and subtropical climates.
If one determines the EHT by any of the methods suggested, and also measures or knows the rate of hydration of the particular obsidian used, it should be possible to carry out absolute dating to ± 10 percent of the true age over periods as short as several years and as long as millions of years.
Variations in the Earth's Orbit: Pacemaker of the Ice Ages
Authors: Hays J. D. , Imbrie John , Shackleton N. J. 
Published: October 2006

1) Three indices of global climate have been monitored in the record of the past 450,000 years in Southern Hemisphere ocean-floor sediments.

2) Over the frequency range 10
–4
to 10
–5
cycle per year, climatic variance of these records is concentrated in three discrete spectral peaks at periods of 23,000, 42,000, and approximately 100,000 years. These peaks correspond to the dominant periods of the earth's solar orbit, and contain respectively about 10, 25, and 50 percent of the climatic variance.

3) The 42,000-year climatic component has the same period as variations in the obliquity of the earth's axis and retains a constant phase relationship with it.
4) The 23,000-year portion of the variance displays the same periods (about 23,000 and 19,000 years) as the quasi-periodic precession index.
5) The dominant, 100,000-year climatic
component has an average period close to, and is in phase with, orbital eccentricity. Unlike the correlations between climate and the higher-frequency orbital variations (which can be explained on the assumption that the climate system responds linearly to orbital forcing), an explanation of the correlation between climate and eccentricity probably requires an assumption of nonlinearity.
6) It is concluded that changes in the earth's orbital geometry are the fundamental cause of the succession of Quaternary ice ages.
7) A model of future climate based on the observed orbital-climate relationships, but ignoring anthropogenic effects, predicts that the long-term trend over the next several thousand years is toward extensive Northern Hemisphere glaciation.
Formation of the Rocky Mountains, Western United States: A Continuum Computer Model
Authors: Bird Peter 
Published: October 2006

One hypothesis for the formation of the Rocky Mountain structures in Late Cretaceous through Eocene time is that a plate of oceanic lithosphere was underthrust horizontally along the base of the North American lithosphere. The horizontal components of the motion of this plate are known from paleomagnetism, and the edges of the region of flat slab can be estimated from reconstructed patterns of volcanism. New techniques of finite-element modeling allow prediction of the thermal and mechanical effects of horizontal subduction on the North American plate. A model that has a realistic temperature-dependent rheology and a simple plane-layered initial condition is used to compute the consequences of horizontal underthrusting in the time interval 75 million to 30 million years before present. Successful predictions of this model include (i) the location, amount, and direction of horizontal shortening that has been inferred from Laramide structures; (ii) massive transport of lower crust from southwest to northeast; (iii) the location and timing of the subsequent extension in metamorphic core complexes and the Rio Grande rift; and (iv) the total area eventually involved in Basin-and-Range style extension.
In a broad sense, this model has predicted the belt of Laramide structures, the transport of crust from the coastal region to the continental interior, the subsequent extension in metamorphic core complexes and the Rio Grande rift, and the geographic region of late Tertiary Basin-and-Range extension. Its principal defects are that (i) many events are predicted about 5 million to 10 million years too late and (ii) the wave of crustal thickening does not travel far enough to the east. Reasonable modifications to the oceanic plate kinematics and rheologies that were assumed may correct these defects.

The correspondence of model predictions to actual geology is already sufficiently close to show that the hypothesis that horizontal subduction caused the Laramide orogeny is probably correct. The Rocky Mountain thrust and reverse faults formed in an environment of east-west to northeast-southwest compressive stress that was caused by the viscous coupling between the oceanic plate and the base of the North American crust. Nonuniform crustal thickening by simple-shear transport also caused relative uplifts; therefore, this model is consistent with both of the range-forming mechanisms that have been inferred (
1
). A new proposal that arises from this simulation is that horizontal subduction also caused the subsequent extensional Basin-and-Range taphrogeny by stripping away the mantle lithosphere so that the crust was exposed to hot asthenosphere after the oceanic slab dropped away.
The Clonal Evolution of Tumor Cell Populations
Authors: Nowell Peter C. 
Published: October 2006

It is proposed that most neoplasms arise from a single cell of origin, and tumor progression results from acquired genetic variability within the original clone allowing sequential selection of more aggressive sublines. Tumor cell populations are apparently more genetically unstable than normal cells, perhaps from activation of specific gene loci in the neoplasm, continued presence of carcinogen, or even nutritional deficiencies within the tumor.
The acquired genetic instability and associated selection process, most readily recognized cytogenetically, results in advanced human malignancies being highly individual karyotypically and biologically. Hence, each patient's cancer may require individual specific therapy, and even this may be thwarted by emergence of a genetically variant subline resistant to the treatment. More research should be directed toward understanding and controlling the evolutionary process in tumors before it reaches the late stage usually seen in clinical cancer.
Explanations of socioeconomic differences in changes in physical function in older adults: results from the Longitudinal Aging Study Amsterdam
Authors: Koster Annemarie , Bosma Hans , Broese van Groenou Marjolein I , Kempen Gertrudis IJM , Penninx Brenda WJH , van Eijk Jacques ThM , Deeg Dorly JH 
Published: October 2006

Abstract

Background
This study examines the association between socioeconomic status and changes in physical function in younger- (aged 55–70 years) and older-old (aged 70–85 years) adults and seeks to determine the relative contribution of diseases, behavioral, and psychosocial factors in explaining this association.

Methods
Data were from 2,366 men and women, aged 55–85 years, participating in the Longitudinal Aging Study Amsterdam (LASA). Two indicators of socioeconomic status were used: education and income. Physical function was measured by self-reported physical ability over nine years of follow-up.

Results
In older adults, low socioeconomic status was related to a poorer level of physical function during nine years of follow-up. In subjects who were between 55 and 70 years old, there was an additional significant socioeconomic-differential decline in physical function, while socioeconomic differentials did not further widen in subjects 70 years and older. Behavioral factors, mainly BMI and physical activity, largely explained the socioeconomic differences in physical function in the youngest age group, while psychosocial factors reduced socioeconomic status differences most in the oldest age group.

Conclusion
The findings indicate age-specificity of both the pattern of socioeconomic status differences in function in older persons and the mechanisms underlying these associations.
Testosterone and Progesterone Rapidly Attenuate Plasma Membrane Gβγ-Mediated Signaling in Xenopus laevis Oocytes by Signaling through Classical Steroid Receptors
Authors: Evaul Kristen , Jamnongjit Michelle , Bhagavath Bala , Hammes Stephen R. 
Published: October 2006

AbstractMany transcription-independent (nongenomic) steroid effects are regulated by G proteins. A well-established, biologically relevant example of steroid/G protein interplay is steroid-triggered oocyte maturation, or meiotic resumption, in Xenopus laevis. Oocyte maturation is proposed to occur through a release of inhibition mechanism whereby constitutive signaling by Gβγ and other G proteins maintains oocytes in meiotic arrest. Steroids (androgens in vivo, and androgens and progesterone in vitro) overcome this inhibition to promote meiotic resumption. To test this model, we used G protein-regulated inward rectifying potassium channels (GIRKs) as markers of Gβγ activity. Overexpression of GIRKs 1 and 2 in Xenopus oocytes resulted in constitutive potassium influx, corroborating the presence of basal Gβγ signaling in resting oocytes. Testosterone and progesterone rapidly reduced potassium influx, validating that steroids attenuate Gβγ activity. Interestingly, reduction of classical androgen receptor (AR) expression by RNA interference abrogated testosterone’s effects on GIRK activity at low, but not high, steroid concentrations. Accordingly, androgens bound to the Xenopus progesterone receptor (PR) at high concentrations, suggesting that, in addition to the AR, the PR might mediate G protein signaling when androgens levels are elevated. In contrast, progesterone bound with high affinity to both the Xenopus PR and AR, indicating that progesterone might signal and promote maturation through both receptors, regardless of its concentration. In sum, these studies introduce a novel method for detecting nongenomic steroid effects on G proteins in live cells in real time, and demonstrate that cross talk may occur between steroids and their receptors during Xenopus oocyte maturation.
Histopathology of congenital subglottic stenosis
Authors: Tucker Gabriel F. , Ossoff Robert H. , Newman Anita N. , Holinger Lauren D. 
Published: October 2006

AbstractThree patients with congenital subglottic stenosis are presented and whole organ serial‐section studies of their larynges are discussed. A superiorly displaced first tracheal ring is observed to form a cartilaginous subglottic stenosis in one. This “trapped first ring” is demonstrated in horizontal, sagittal and coronal planes. Subglottic stenosis is a clinical diagnosis which describes multifarious histopathological forms of narrowing within the subglottic larynx.
The prognostic significance of metastatic cervical lymph nodes
Authors: Schuller David E. , McGuirt W. Fred , McCabe Brian F. , Young Donn 
Published: October 2006

AbstractThe ability to predict accurately the clinical course of a patient with a malignancy is critically important to the patient's subsequent management. It has been well documented that the presence of metastatic nodal disease is associated with decreased patient survival. Survival data from a group of 242 head and neck cancer patients from the University of Iowa were analyzed to determine the significance of specific characteristics of metastatic lymph nodes. Evaluation of absolute numbers and percentages of positive nodes or node size generally was not useful. However, involvement of the posterior triangle nodes, non‐contiguous nodal sites, or multiple sites was associated with a worse prognosis. When nodal features were considered individually or collectively, there was no consistent finding that was accurate enough to be of help to the clinician in prognostication. The single most important feature seems to be documentation of the presence of metastatic nodal disease, rather than particular features (i.e., number, size) of the metastatic nodes.
Sucking Performance of Babies with Cleft Conditions
Authors: Reid Julie , Reilly Sheena , Kilpatrick Nicky 
Published: October 2006

Objective: To describe the sucking performance of bottle-fed babies with cleft conditions. Participants: Forty 2-week-old-babies with cleft lip (CL; n = 8), cleft palate (CP; n = 22), and cleft lip and palate (CLP; n = 10) were examined. Methods: Suction, compression, and other sucking parameters were measured during bottle-feeding and compared to determine if they varied with cleft condition or feeding ability. Results: All babies with CL and one with CLP demonstrated suction. Thirteen of 22 babies with CP demonstrated suction but only three maintained regular pressure changes over time. Between-group differences in the amplitude of suction and compression were associated with cleft condition. Cleft lip participants demonstrated the greatest amplitude of suction followed by those with CP and CLP. Cleft lip and CP participants generated similar amplitudes of compression. This was greater than their counterparts with CLP. Good feeders (n = 15) generated high levels of suction, while satisfactory (n = 15) and poor feeders (n = 10) did not generate any during bottle-feeding. Conclusion: Between-group differences in intra-oral pressures were confirmed when babies were examined by cleft condition. Babies with smaller clefts (i.e., CL or minor soft palate clefts) were more likely to generate normal levels of suction and compression compared to their counterparts with larger clefts. Since good feeders were more likely to have smaller clefts it was not surprising that they demonstrated higher suction pressures than babies with satisfactory or poor feeding ability. Compression values were not significantly different across the feeding ability groups. These data may inform feeding management strategies.
Sonographic diagnosis of a saccular aneurysm of the internal jugular vein
Authors: Lee Hwa Yeon , Yoo Seung Min , Song In‐Sup , Yu Hyeon , Lee Jong Beum 
Published: October 2006

AbstractAneurysm of the internal jugular vein is an extremely rare condition. It is usually detected during childhood and is characterized by being more prominent during Valsalva maneuvers such as vomiting, coughing, and straining. Most of the cases reported in the English literature are fusiform aneurysms of the internal jugular vein. We report the case of a saccular aneurysm of the left internal jugular vein in a 59‐year‐old woman with no change in size of the aneurysm during a Valsalva manuever. © 2006 Wiley Periodicals, Inc. J Clin Ultrasound, 2006
The utility of zebrafish for studies of the comparative biology of motor systems
Authors: Fetcho Joseph R. 
Published: October 2006

AbstractAlthough zebrafish are best known as a model for studies of development, there is now a growing role for the model in studies of the functional organization of the nervous system, including studies of a variety of sensory systems, central processing, and motor output. The zebrafish has much to offer for such work because of the unique combination of genetics, optical methods, and physiology it allows. Here I illustrate, using three examples, the broad range of avenues along which zebrafish can inform us about motor systems. The examples include efforts to understand the functional organization and evolution of spinal interneurons, the role of mutants in informing us about motor dysfunction and human disease, and the ability to use the special features of zebrafish to explore strategies to restore function after injury. The most important aspects of these studies are evident only when they are placed in a comparative context, so they serve to highlight the power of zebrafish in studies of the comparative biology of motor control. J. Exp. Zool. (Mol. Dev. Evol.) 308B:550–562, 2007. © 2006 Wiley‐Liss, Inc.
Application of a pigment measuring device – Mexameter®– for the differential diagnosis of vitiligo and nevus depigmentosus
Authors: Park Eun Sang , Na Jung Im , Kim Seon Ok , Huh Chang Hun , Youn Sang Woong , Park Kyoung Chan 
Published: October 2006

Background/purpose: Vitiligo and nevus depigmentosus (ND) present similar hypopigmented macules with significantly different prognoses. Although the distinction between the two diseases is important, differential diagnosis relies on medical history and physical examination, which is far from decisive in some cases. The Mexameter® is an objective skin color‐measuring device, and has been reported to provide a reproducible and sensitive means of quantifying small skin color differences. In this study, we investigated the usefulness of a Mexameter® for discriminating these diseases.Methods: A selection of 202 hypopigmented skin lesions (182 from vitiligo and 20 from ND) were the objects of this study. Using a Mexameter, MIs were obtained from lesions and symmetrically located control skin. RMIs, ratios of the MIs of lesional skins to control skins, were calculated.Results: The mean MIs and RMIs were significantly different for vitiligo and ND. The mean RMI of ND lesions was 74±13, which was significantly higher than that of vitiligo lesions (50±24). No ND lesion had an RMI of <50%.Conclusion: This study shows that the Mexameter®, an objective pigment‐measuring device, can be used to achieve a more accurate diagnosis of hypopigmentary disorders, and that the relative melanin index (RMI), which represents the relative pigment levels, might be a more effective parameter than the melanin index (MI) itself for comparing pigmentation differences.